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Sample records for change post-field season

  1. Changes in body composition and bone of female collegiate soccer players through the competitive season and off-season

    Science.gov (United States)

    Minett, M.M.; Binkley, T.B.; Weidauer, L.A.; Specker, B.L.

    2017-01-01

    Objectives: To assess body composition and bone changes pre- to post-season (pre-post) and post- to off-season (post-off) in female soccer athletes (SC). Methods: Outcomes were assessed using DXA and pQCT in 23 SC and 17 controls at three times throughout season. Results: SC, non-starters in particular, lost lean mass pre-post (-0.9±0.2 kg, pSoccer players lost lean mass over the competitive season that was not recovered during off-season. Bone size increased pre- to post-season. Female soccer athletes experience body composition and bone geometry changes that differ depending on the time of season and on athlete’s playing status. Evaluations of athletes at key times across the training season are necessary to understand changes that occur. PMID:28250243

  2. [Animals' clever adaptation strategy for seasonal changes in environment].

    Science.gov (United States)

    Ikegami, Keisuke; Yoshimura, Takashi

    2015-08-01

    Organisms living outside of tropical zones experience seasonal changes in environment. Organisms are using day length as a calendar to change their physiology and behavior such as seasonal breeding, hibernation, migration, and molting. A comparative biology approach revealed underlying mechanisms of vertebrate seasonal reproduction. Here we review the current understanding of vertebrate seasonal reproduction. We Aso describe the involvement of tissue-specific post-translational modification in functional diversification of a hormone.

  3. Climate change and prolongation of growing season: changes in regional potential for field crop production in Finland

    Directory of Open Access Journals (Sweden)

    P. PELTONEN-SAINIO

    2008-12-01

    Full Text Available Climate change offers new opportunities for Finnish field crop production, which is currently limited by the short growing season. A warmer climate will extend the thermal growing season and the physiologically effective part of it. Winters will also become milder, enabling introduction of winter-sown crops to a greater extent than is possible today. With this study we aim to characterise the likely regional differences in capacity to grow different seed producing crops. Prolongation of the Finnish growing season was estimated using a 0.5º latitude × 0.5º longitude gridded dataset from the Finnish Meteorological Institute. The dataset comprised an average estimate from 19 global climate models of the response of Finnish climate to low (B1 and high (A2 scenarios of greenhouse gas and aerosol emissions for 30-year periods centred on 2025, 2055 and 2085 (Intergovernmental Panel on Climate Change. Growing season temperature sums that suit crop growth and are agronomically feasible in Finland are anticipated to increase by some 140 °Cd by 2025, 300 °Cd by 2055 and 470 °Cd by 2085 in scenario A2, when averaged over regions, and earlier sowing is expected to take place, but not later harvests. Accordingly, the extent of cultivable areas for the commonly grown major and minor crops will increase considerably. Due to the higher base temperature requirement for maize (Zea mays L. growth than for temperate crops, we estimate that silage maize could become a Finnish field crop for the most favourable growing regions only at the end of this century. Winters are getting milder, but it will take almost the whole century until winters such as those that are typical for southern Sweden and Denmark are experienced on a wide scale in Finland. It is possible that introduction of winter-sown crops (cereals and rapeseed will represent major risks due to fluctuating winter conditions, and this could delay their adaptation for many decades. Such risks need to be

  4. Small mammal use of native warm-season and non-native cool-season grass forage fields

    Science.gov (United States)

    Ryan L Klimstra,; Christopher E Moorman,; Converse, Sarah J.; Royle, J. Andrew; Craig A Harper,

    2015-01-01

    Recent emphasis has been put on establishing native warm-season grasses for forage production because it is thought native warm-season grasses provide higher quality wildlife habitat than do non-native cool-season grasses. However, it is not clear whether native warm-season grass fields provide better resources for small mammals than currently are available in non-native cool-season grass forage production fields. We developed a hierarchical spatially explicit capture-recapture model to compare abundance of hispid cotton rats (Sigmodon hispidus), white-footed mice (Peromyscus leucopus), and house mice (Mus musculus) among 4 hayed non-native cool-season grass fields, 4 hayed native warm-season grass fields, and 4 native warm-season grass-forb ("wildlife") fields managed for wildlife during 2 summer trapping periods in 2009 and 2010 of the western piedmont of North Carolina, USA. Cotton rat abundance estimates were greater in wildlife fields than in native warm-season grass and non-native cool-season grass fields and greater in native warm-season grass fields than in non-native cool-season grass fields. Abundances of white-footed mouse and house mouse populations were lower in wildlife fields than in native warm-season grass and non-native cool-season grass fields, but the abundances were not different between the native warm-season grass and non-native cool-season grass fields. Lack of cover following haying in non-native cool-season grass and native warm-season grass fields likely was the key factor limiting small mammal abundance, especially cotton rats, in forage fields. Retention of vegetation structure in managed forage production systems, either by alternately resting cool-season and warm-season grass forage fields or by leaving unharvested field borders, should provide refugia for small mammals during haying events.

  5. Changes in Muscle Architecture, Explosive Ability, and Track and Field Throwing Performance Throughout a Competitive Season and After a Taper.

    Science.gov (United States)

    Bazyler, Caleb D; Mizuguchi, Satoshi; Harrison, Alex P; Sato, Kimitake; Kavanaugh, Ashley A; DeWeese, Brad H; Stone, Michael H

    2017-10-01

    The purpose of this study was to examine the effects of an overreach and taper on measures of muscle architecture, jumping, and throwing performance in Division I collegiate throwers preparing for conference championships. Six collegiate track and field throwers (3 hammer, 2 discus, 1 javelin) trained for 12 weeks using a block-periodization model culminating with a 1-week overreach followed by a 3-week taper (ORT). Session rating of perceived exertion training load (RPETL) and strength training volume-load times bar displacement (VLd) were recorded weekly. Athletes were tested pre-ORT and post-ORT on measures of vastus lateralis architecture, unloaded and loaded squat and countermovement jump performance, underhand and overhead throwing performance, and competition throwing performance. There was a statistical reduction in weight training VLd/session (d = 1.21, p ≤ 0.05) and RPETL/session (d = 0.9, p ≤ 0.05) between the in-season and ORT training phases. Five of 6 athletes improved overhead throw and competition throwing performance after the ORT (d = 0.50, p ≤ 0.05). Vastus lateralis muscle thickness statistically increased after the in-season training phase (d = 0.28, p ≤ 0.05) but did not change after the ORT. Unloaded countermovement jump peak force and relative peak power improved significantly after the ORT (d = 0.59, p ≤ 0.05, d = 0.31, p ≤ 0.05, respectively). These findings demonstrate that an overreaching week followed by a 3-week taper is an effective means of improving explosive ability and throwing performance in collegiate track and field throwers despite the absence of detectable changes in muscle architecture.

  6. Grassland bird productivity in warm season grass fields in southwest Wisconsin

    Science.gov (United States)

    Byers, Carolyn M.; Ribic, Christine; Sample, David W.; Dadisman, John D.; Guttery, Michael

    2017-01-01

    Surrogate grasslands established through federal set-aside programs, such as U.S. Department of Agriculture's Conservation Reserve Program (CRP), provide important habitat for grassland birds. Warm season grass CRP fields as a group have the potential for providing a continuum of habitat structure for breeding birds, depending on how the fields are managed and their floristic composition. We studied the nesting activity of four obligate grassland bird species, Bobolink (Dolichonyx oryzivorus), Eastern Meadowlark (Sturnella magna), Grasshopper Sparrow (Ammodramus savannarum), and Henslow's Sparrow (A. henslowii), in relation to vegetative composition and fire management in warm season CRP fields in southwest Wisconsin during 2009–2011. Intraspecific variation in apparent nest density was related to the number of years since the field was burned. Apparent Grasshopper Sparrow nest density was highest in the breeding season immediately following spring burns, apparent Henslow's Sparrow nest density was highest 1 y post burn, and apparent Bobolink and Eastern Meadowlark nest densities were higher in post fire years one to three. Grasshopper Sparrow nest density was highest on sites with more diverse vegetation, specifically prairie forbs, and on sites with shorter less dense vegetation. Bobolink, Eastern Meadowlark, and Henslow's Sparrow apparent nest densities were higher on sites with deeper litter; litter was the vegetative component that was most affected by spring burns. Overall nest success was 0.487 for Bobolink (22 d nesting period), 0.478 for Eastern Meadowlark (25 d nesting period), 0.507 for Grasshopper Sparrow (22 d nesting period), and 0.151 for Henslow's Sparrow (21 d nesting period). The major nest predators were grassland-associated species: thirteen-lined ground squirrel (Ictidomys tridecemlineatus), striped skunk (Mephitis mephitis), milk snake (Lampropeltis triangulum), American badger (Taxidea taxus), and western fox snake (Elaphe vulpina). Overall

  7. Seasonal dependence of high-latitude electric fields

    International Nuclear Information System (INIS)

    de la Beaujardiere, O.; Leger, C.; Alcayde, D.; Fontanari, J.

    1991-01-01

    The seasonal dependence of the high-latitude electric field was investigated using Sondrestrom incoherent scatter radar data. Average ExB drifts were derived from 5 years of measurements centered around solar minimum. The electrostatic potentials that best fit the observed average electric field were calculated. It was found that the large-scale convection pattern significantly changes with season. This change involves the overall shape of the convection pattern, as well as the electric field intensity, and thus the total dawn-dusk potential across the polar cap. The cross polar cap potential drop is largest in fall, followed by winter, spring and summer. The small difference found between the summer and winter cross polar cap potential can be attributed to differing field-aligned potential drops. In view of the well-known relationship between field-aligned currents and parallel potential drop, this is consistent with the observations that Birkeland currents are larger in the summer than in winter. Changes in the overall shape of the convection pattern are consistent with the simple notion that the whole pattern is shifted toward the nightside as well as, to a lesser extent, toward the dawnside in summer as compared to winter. This assumption is based on the following observed effects: (1) The rotation of the overall convection pattern toward earlier local times with respect to the noon-midnight direction is maximum for summer on the dayside. (2) On the nightside, the Harang discontinuity is typically located within the radar field of view (Λ=67 to 82) in the winter averaged patterns, but it is equatorward of the field of view in summer. (3) The line that joins the dawn and dusk potential maxima is shifted toward the midnight sector in summer as compared to winter by about 5 degree. (4) In the dawn cell, the latitude of the convection reversal is the lowest during summer; in the dusk cell the latitude of the reversal is the lowest during winter

  8. Season-controlled changes in biochemical constituents and oxidase enzyme activities in tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Sen, Supatra; Mukherji, S

    2009-07-01

    Season-controlled changes in biochemical constituents viz. carotenoids (carotene and xanthophyll) and pectic substances along with IAA-oxidase and polyphenol oxidase (PPO) enzyme activities were estimated/assayed in leaves of Lycopersicon esculentum Mill. (tomato) in two developmental stages--pre-flowering (35 days after sowing) and post-flowering (75 days after sowing) in three different seasons--summer rainy and winter Carotenoid content along with pectic substances were highest in winter and declined significantly in summer followed by rainy i.e. winter > summer > rainy. Carotenoid content was significantly higher in the pre-flowering as compared to post-flowering in all three seasons while pectic substances increased in the post-flowering as compared to pre-flowering throughout the annual cycle. IAA oxidase and PPO enzyme activities were enhanced in rainy and decreased sharply in summer and winter i.e. rainy > summer > winter. Both the enzymes exhibited higher activity in the post-flowering stage as compared to pre-flowering in all three seasons. These results indicate winter to be the most favourable season for tomato plants while rainy season environmental conditions prove to be unfavourable (stressful) with diminished content of carotenoid and pectic substances and low activities of IAA oxidase and PPO, ultimately leading to poor growth and productivity.

  9. Seasonal Changes in Bird Species and Feeding Guilds along Elevational Gradients of the Central Himalayas, Nepal

    Science.gov (United States)

    Katuwal, Hem Bahadur; Basnet, Khadga; Khanal, Bhaiya; Devkota, Shiva; Rai, Sanjeev Kumar; Gajurel, Jyoti Prasad; Scheidegger, Christoph; Nobis, Michael P.

    2016-01-01

    The Himalayas are a global hotspot for bird diversity with a large number of threatened species, but little is known about seasonal changes in bird communities along elevational gradients in this region. We studied the seasonality of bird diversity in six valleys of the Central Himalayas, Nepal. Using 318 plots with a 50 m radius, located from 2200 to 3800 m a.s.l., and repeated sampling during different seasons (mainly pre-monsoon, monsoon, and post-monsoon), we analyzed 3642 occurrences of 178 species. Birds classified in the literature as resident were more species-rich than migratory birds (140 vs. 38 species). In all six valleys and within the studied elevation range, species richness of all birds showed a peak at mid-elevation levels of 2600 or 3000 m a.s.l. Similar patterns were found for the most species-rich feeding guilds of insectivores (96 species) and omnivores (24 species), whereas the species richness of herbivores (37 species including frugivores) increased towards higher elevations. Among these feeding guilds, only species richness of insectivores showed pronounced seasonal changes with higher species numbers during post-monsoon season. Similarly, individual bird species showed distinct spatio-temporal distribution patterns, with transitions from species dominated by elevational differences to those characterized by strong seasonal changes. In an era of climate change, the results demonstrate that individual bird species as well as feeding guilds might greatly differ in their responses to climate warming and changes in the seasonality of the precipitation regime, two aspects of climate change which should not be analyzed independently. PMID:27367903

  10. Seasonal changes in the European gravity field from GRACE: A comparison with superconducting gravimeters and hydrology model predictions

    DEFF Research Database (Denmark)

    Hinderer, J.; Andersen, Ole Baltazar; Lemoine, F.

    2006-01-01

    This paper is devoted to the investigation of seasonal changes of the Earth's gravity field from GRACE satellites and the comparison with surface gravity measurements in Europe from the Global Geodynamics Project (GGP) sub-network, as well as with recent hydrology models for continental soil...... moisture and snow. We used gravity maps in Europe retrieved from the initial GRACE monthly solutions spanning a 21 -month duration from April 2002 to December 2003 for various truncation levels of the initial spherical harmonic decomposition of the field. The transfer function between satellite......-derived and ground gravity changes due to continental hydrology is studied and we also compute the theoretical ratio of gravity versus radial displacement (in mu Gal/mm) involved in the hydrological loading process. The 'mean' value (averaged in time and in space over Europe) from hydrologic forward modeling...

  11. A Bayesian modelling method for post-processing daily sub-seasonal to seasonal rainfall forecasts from global climate models and evaluation for 12 Australian catchments

    Science.gov (United States)

    Schepen, Andrew; Zhao, Tongtiegang; Wang, Quan J.; Robertson, David E.

    2018-03-01

    Rainfall forecasts are an integral part of hydrological forecasting systems at sub-seasonal to seasonal timescales. In seasonal forecasting, global climate models (GCMs) are now the go-to source for rainfall forecasts. For hydrological applications however, GCM forecasts are often biased and unreliable in uncertainty spread, and calibration is therefore required before use. There are sophisticated statistical techniques for calibrating monthly and seasonal aggregations of the forecasts. However, calibration of seasonal forecasts at the daily time step typically uses very simple statistical methods or climate analogue methods. These methods generally lack the sophistication to achieve unbiased, reliable and coherent forecasts of daily amounts and seasonal accumulated totals. In this study, we propose and evaluate a Rainfall Post-Processing method for Seasonal forecasts (RPP-S), which is based on the Bayesian joint probability modelling approach for calibrating daily forecasts and the Schaake Shuffle for connecting the daily ensemble members of different lead times. We apply the method to post-process ACCESS-S forecasts for 12 perennial and ephemeral catchments across Australia and for 12 initialisation dates. RPP-S significantly reduces bias in raw forecasts and improves both skill and reliability. RPP-S forecasts are also more skilful and reliable than forecasts derived from ACCESS-S forecasts that have been post-processed using quantile mapping, especially for monthly and seasonal accumulations. Several opportunities to improve the robustness and skill of RPP-S are identified. The new RPP-S post-processed forecasts will be used in ensemble sub-seasonal to seasonal streamflow applications.

  12. SEASONAL CHANGES IN TITAN'S SURFACE TEMPERATURES

    International Nuclear Information System (INIS)

    Jennings, D. E.; Cottini, V.; Nixon, C. A.; Flasar, F. M.; Kunde, V. G.; Samuelson, R. E.; Romani, P. N.; Hesman, B. E.; Carlson, R. C.; Gorius, N. J. P.; Coustenis, A.; Tokano, T.

    2011-01-01

    Seasonal changes in Titan's surface brightness temperatures have been observed by Cassini in the thermal infrared. The Composite Infrared Spectrometer measured surface radiances at 19 μm in two time periods: one in late northern winter (LNW; L s = 335 deg.) and another centered on northern spring equinox (NSE; L s = 0 deg.). In both periods we constructed pole-to-pole maps of zonally averaged brightness temperatures corrected for effects of the atmosphere. Between LNW and NSE a shift occurred in the temperature distribution, characterized by a warming of ∼0.5 K in the north and a cooling by about the same amount in the south. At equinox the polar surface temperatures were both near 91 K and the equator was at 93.4 K. We measured a seasonal lag of ΔL S ∼ 9 0 in the meridional surface temperature distribution, consistent with the post-equinox results of Voyager 1 as well as with predictions from general circulation modeling. A slightly elevated temperature is observed at 65 0 S in the relatively cloud-free zone between the mid-latitude and southern cloud regions.

  13. Seasonal Changes in Central England Temperatures

    DEFF Research Database (Denmark)

    Proietti, Tommaso; Hillebrand, Eric

    The aim of this paper is to assess how climate change is reflected in the variation of the seasonal patterns of the monthly Central England Temperature time series between 1772 and 2013. In particular, we model changes in the amplitude and phase of the seasonal cycle. Starting from the seminal work...... by Thomson (“The Seasons, Global Temperature and Precession”, Science, 7 April 1995, vol 268, p. 59–68), a number of studies have documented a shift in the phase of the annual cycle implying an earlier onset of the spring season at various European locations. A significant reduction in the amplitude...... and stochastic trends, as well as seasonally varying autocorrelation and residual variances. The model can be summarized as containing a permanent and a transitory component, where global warming is captured in the permanent component, on which the seasons load differentially. The phase of the seasonal cycle...

  14. A Bayesian modelling method for post-processing daily sub-seasonal to seasonal rainfall forecasts from global climate models and evaluation for 12 Australian catchments

    Directory of Open Access Journals (Sweden)

    A. Schepen

    2018-03-01

    Full Text Available Rainfall forecasts are an integral part of hydrological forecasting systems at sub-seasonal to seasonal timescales. In seasonal forecasting, global climate models (GCMs are now the go-to source for rainfall forecasts. For hydrological applications however, GCM forecasts are often biased and unreliable in uncertainty spread, and calibration is therefore required before use. There are sophisticated statistical techniques for calibrating monthly and seasonal aggregations of the forecasts. However, calibration of seasonal forecasts at the daily time step typically uses very simple statistical methods or climate analogue methods. These methods generally lack the sophistication to achieve unbiased, reliable and coherent forecasts of daily amounts and seasonal accumulated totals. In this study, we propose and evaluate a Rainfall Post-Processing method for Seasonal forecasts (RPP-S, which is based on the Bayesian joint probability modelling approach for calibrating daily forecasts and the Schaake Shuffle for connecting the daily ensemble members of different lead times. We apply the method to post-process ACCESS-S forecasts for 12 perennial and ephemeral catchments across Australia and for 12 initialisation dates. RPP-S significantly reduces bias in raw forecasts and improves both skill and reliability. RPP-S forecasts are also more skilful and reliable than forecasts derived from ACCESS-S forecasts that have been post-processed using quantile mapping, especially for monthly and seasonal accumulations. Several opportunities to improve the robustness and skill of RPP-S are identified. The new RPP-S post-processed forecasts will be used in ensemble sub-seasonal to seasonal streamflow applications.

  15. Variations between post- and pre-harvest seasons in stunting ...

    African Journals Online (AJOL)

    Minimum meal frequency, minimum acceptable diet and poor dietary diversity increased considerably in pre-harvest compared to post-harvest season in the lowland zone. Feeding practices and maternal age were predictors of wasting, while women's dietary diversity and children age was predictor of child dietary diversity ...

  16. Influenza in the immediate post-pandemic era : A comparison with seasonal and pandemic influenza in hospitalized patients

    NARCIS (Netherlands)

    Rahamat-Langendoen, J. C.; Tutuhatunewa, E. D.; Scholvinck, E. H.; Hak, E.; Koopmans, M.; Niesters, H. G. M.; Riezebos-Brilman, A.

    Background: Comparative data on severity and treatment of seasonal, pandemic and post-pandemic influenza virus infections are scarce. Objectives: To systematically analyze characteristics of hospitalized patients with influenza in the post-pandemic period compared to seasonal and pandemic influenza.

  17. Field-scale water balance closure in seasonally frozen conditions

    Directory of Open Access Journals (Sweden)

    X. Pan

    2017-11-01

    Full Text Available Hydrological water balance closure is a simple concept, yet in practice it is uncommon to measure every significant term independently in the field. Here we demonstrate the degree to which the field-scale water balance can be closed using only routine field observations in a seasonally frozen prairie pasture field site in Saskatchewan, Canada. Arrays of snow and soil moisture measurements were combined with a precipitation gauge and flux tower evapotranspiration estimates. We consider three hydrologically distinct periods: the snow accumulation period over the winter, the snowmelt period in spring, and the summer growing season. In each period, we attempt to quantify the residual between net precipitation (precipitation minus evaporation and the change in field-scale storage (snow and soil moisture, while accounting for measurement uncertainties. When the residual is negligible, a simple 1-D water balance with no net drainage is adequate. When the residual is non-negligible, we must find additional processes to explain the result. We identify the hydrological fluxes which confound the 1-D water balance assumptions during different periods of the year, notably blowing snow and frozen soil moisture redistribution during the snow accumulation period, and snowmelt runoff and soil drainage during the melt period. Challenges associated with quantifying these processes, as well as uncertainties in the measurable quantities, caution against the common use of water balance residuals to estimate fluxes and constrain models in such a complex environment.

  18. HealthLines: Seasons Change, Moods Change

    Science.gov (United States)

    ... the onset of a form of depression called seasonal affective disorder (SAD). Most commonly, SAD usually occurs ... time. Others include: medicines, changes in diet, and stress management. If you ... Water Well? If your water comes from a private ...

  19. Scope on the Skies: Changing of the Seasons

    Science.gov (United States)

    Riddle, Bob

    2011-01-01

    Learn the astronomy behind the changing of the seasons. Students know that we mark the change of seasons with the position of the Sun over certain parts of the Earth. The specific time and date for the change of seasons is determined by the position of the Sun, not above the horizon necessarily, nor geographically, but rather where the Sun is…

  20. Changes in muscle architecture and performance during a competitive season in female softball players.

    Science.gov (United States)

    Nimphius, Sophia; McGuigan, Michael R; Newton, Robert U

    2012-10-01

    The purpose of this research was (a) to examine the performance changes that occur in elite female softball players during 20 weeks of softball training (that included 14 weeks of periodized resistance training [RT]) and (b) to examine the relationship between percent change (%change) in muscle architecture variables and %change in strength, speed, and change of direction performance. Ten female softball players (age = 18.1 ± 1.6 years, height = 166.5 ± 8.9 cm, weight = 72.4 ± 10.8 kg) from a state Australian Institute of Sport softball team were tested for maximal lower-body strength using a 3 repetition maximum for a predicted 1 repetition maximum (1RM) and peak force, peak velocity (PV), and peak power (PP) were measured during jump squats (JS) unloaded and loaded. In addition, the first base (1B) and the second base (2B) sprint performance, change of direction (505) on dominant (D) and nondominant (ND) sides, aerobic capacity, and muscle architecture characteristics of vastus lateralis (VL) including muscle thickness (MT), fascicle length (FL), and pennation angle (θp) were examined. The testing sessions occurred pre, mid, and post training (total 20 week pre- and in-season training period). Changes over time were analyzed by repeated-measures analysis of variance. The relationship between %change in muscle architecture variables and strength, speed, and change of direction variables from pre to post were assessed by Pearson product-moment correlation coefficient. Significant improvements in PV and PP occurred at all JS loads pre- to mid-testing and pre- to post-testing. Significant increases occurred pre-post in absolute 1RM, relative 1RM, 505 ND, and 2B sprint. The strongest relationships were found between %change in VL MT and 1B sprint (r = -0.80, p = 0.06), %change in VL FL and 2B sprint (r = -0.835, p = 0.02), and %change in relative 1RM and 505 D (r = -0.70, p = 0.04). In conclusion, gains in strength, power, and performance can occur during the

  1. Seasonal gravity change at Yellowstone caldera

    Science.gov (United States)

    Poland, M. P.; de Zeeuw-van Dalfsen, E.

    2017-12-01

    The driving forces behind Yellowstone's dynamic deformation, vigorous hydrothermal system, and abundant seismicity are usually ascribed to "magmatic fluids," which could refer to magma, water, volatiles, or some combination. Deformation data alone cannot distinguish the relative importance of these fluids. Gravity measurements, however, provide an indication of mass change over time and, when combined with surface displacements, can constrain the density of subsurface fluids. Unfortunately, several decades of gravity surveys at Yellowstone have yielded ambiguous results. We suspect that the difficulty in interpreting Yellowstone gravity data is due to seasonal variations in environmental conditions—especially surface and ground water. Yellowstone gravity surveys are usually carried out at the same time of year (generally late summer) to minimize the impact of seasonality. Nevertheless, surface and subsurface water levels are not likely to be constant from year to year, given annual differences in precipitation. To assess the overall magnitude of seasonal gravity changes, we conducted gravity surveys of benchmarks in and around Yellowstone caldera in May, July, August, and October 2017. Our goal was to characterize seasonal variations due to snow melt/accumulation, changes in river and lake levels, changes in groundwater levels, and changes in hydrothermal activity. We also hope to identify sites that show little variation in gravity over the course of the 2017 surveys, as these locations may be less prone to seasonal changes and more likely to detect small variations due to magmatic processes. Preliminary examination of data collected in May and July 2017 emphasizes the importance of site location relative to sources of water. For example, a site on the banks of the Yellowstone River showed a gravity increase of several hundred microgals associated with a 50 cm increase in the river level. A high-altitude site far from rivers and lakes, in contrast, showed a

  2. Changes in Creatine Kinase and Hormones over the Course of an American Football Season.

    Science.gov (United States)

    Stone, J D; Kreutzer, A; Mata, J D; Nystrom, M G; Jagim, A R; Jones, M T; Oliver, J M

    2017-04-04

    The purpose of this study was to examine changes in creatine kinase and hormones over the course of an entire season of American football. A secondary purpose was to determine differences between starters and non-starters. Fasting blood samples were obtained from nineteen National Collegiate Athletic Association Division I (n = 19; 20 ± 1 years) football athletes over the course of a season beginning prior to the start of summer off-season conditioning (T1), before (T2) and after pre-season (T3) football camp, with remaining samples taken throughout the competitive season (T4-T8). A magnitude-based inference approach was used to define outcomes. Testosterone was higher in starters prior to the start of the season (T1, Effect Size [ES] = 0.8) and during pre-conference (T4; ES = 0.7). Post-Camp (T3) testosterone was lower in all players, though greater in starters (starters, 0.0%/0.3%/99.7%; non-starters, 0.2%/2.9%/96.9%). An increase cortisol relative to baseline (T1) was observed in starters early in season (T4, ES = 0.7; T5, ES = 0.5). Creatine kinase was elevated at all time-points in all athletes, with starters having higher circulating levels throughout season. These data demonstrate that changes in hormonal markers may be experienced over a season of football and differ by playing status. Differences between starters and non-starters may be indicative of greater damage and stress experienced by starters, which may result from a greater number of repetitions.

  3. Influence Of Summer Season On Some Biochemical And Hormonal Changes In Crossbred Cows During Suckling Period

    International Nuclear Information System (INIS)

    Teama, F.E.I.; Gad, A.E.

    2012-01-01

    According to the seasonal variations in environmental conditions in post-partum cows, some biochemical and physiological changes which affect the productive efficiency of farm animals may occur. This study was conducted in the bovine farm of Experimental Farms Project of Nuclear Research Centre, Atomic Energy Authority, Inshas, Egypt, to evaluate some blood biochemical and some hormonal changes during the suckling period in crossbred cows under winter and summer conditions. Alterations in metabolites and metabolic hormones during the first 10 weeks post-partum in both winter and summer during a period of suckling were analyzed on a total of 13 crossbred (Brown Swiss X Balady) cows (winter, n=7; summer, n=6). The blood samples were taken at 2 weeks intervals, 5 times in each season to determine the concentrations and changes in glucose, urea, total cholesterol, total proteins and some hormones including leptin, T4 and progesterone (P4) under winter and summer conditions. The data indicated that total protein (P<0.01), glucose (P<0.05), leptin (P<0.01), total cholesterol (P<0.01), and T4 (P<0.01) had significant seasonal differences between the two calving groups. A positive correlation coefficient was observed between leptin and T4 hormone. From the obtained data, it could be concluded that in summer season, certain biochemical and hormonal levels of calving cows may enhanced but not enough to affect the levels of urea and progesterone. The positive correlation between leptin and T4 may indicate association in the rate of metabolism.

  4. EFFECTS OF SEASON OF SOWING ON WATER USE AND YIELD ...

    African Journals Online (AJOL)

    (Received 9 May, 2000; accepted 5 May, 2002) Abstract Soil water availability is a major constraint to crop production in the post-rainy season period in the humid tropics. The seasonal pattern of water use was, therefore, studied in field-grown tomato (Lycopersicum esculentum) during two consecutive rainy and post-rainy ...

  5. Assessing impact of climate change on season length in Karnataka

    Indian Academy of Sciences (India)

    Changes in seasons and season length are an indicator, as well as an effect, of climate change. Seasonal change profoundly affects the balance of life in ecosystems and impacts essential human activities such as agriculture and irrigation. This study investigates the uncertainty of season length in Karnataka state, India, ...

  6. Pre and Post-monsoon Seasonal Variation of some Heavy Metal ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: The concentration of heavy metals (Fe, As and Cu) was examine in riverbed sediments of Gomti river, Lucknow at selected sites in pre and post monsoon season for three consecutive years (2009-11). The concentration was ranged between (As: 0.07-0.7, Fe: 7462.00-7977.00, Cu: 10.98-36.73 μg g-1) in ...

  7. Observations and modeling of post-midnight uplifts near the magnetic equator

    Directory of Open Access Journals (Sweden)

    M. J. Nicolls

    2006-07-01

    Full Text Available We report here on post-midnight uplifts near the magnetic equator. We present observational evidence from digital ionosondes in Brazil, a digisonde in Peru, and other measurements at the Jicamarca Radio Observatory that show that these uplifts occur fairly regularly in the post-midnight period, raising the ionosphere by tens of kilometers in the most mild events and by over a hundred kilometers in the most severe events. We show that in general the uplifts are not the result of a zonal electric field reversal, and demonstrate instead that the uplifts occur as the ionospheric response to a decreasing westward electric field in conjunction with sufficient recombination and plasma flux. The decreasing westward electric field may be caused by a change in the wind system related to the midnight pressure bulge, which is associated with the midnight temperature maximum. In order to agree with observations from Jicamarca and Palmas, Brazil, it is shown that there must exist sufficient horizontal plasma flux associated with the pressure bulge. In addition, we show that the uplifts may be correlated with a secondary maximum in the spread-F occurrence rate in the post-midnight period. The uplifts are strongly seasonally dependent, presumably according to the seasonal dependence of the midnight pressure bulge, which leads to the necessary small westward field in the post-midnight period during certain seasons. We also discuss the enhancement of the uplifts associated with increased geomagnetic activity, which may be related to disturbance dynamo winds. Finally, we show that it is possible using simple numerical techniques to estimate the horizontal plasma flux and the vertical drift velocity from electron density measurements in the post-midnight period.

  8. Effect of Climate Extremes, Seasonal Change, and Agronomic Practices on Measured Evapotranspiration and CO2 Exchange in Sacramento-San Joaquin River Delta Alfalfa Fields

    Science.gov (United States)

    Clay, J.; Kent, E. R.; Leinfelder-Miles, M.; Paw U, K. T.; Little, C.; Lambert, J. J.

    2017-12-01

    Evapotranspiration and CO2 exchange was measured in five alfalfa fields in the Sacramento-San Joaquin River Delta region from 2016 to 2017 using eddy covariance and surface renewal methods. Seasonal changes of evapotranspiration and CO2 fluxes were compared between 2016, a drought year, and 2017, a high rainfall year. Additionally, changes in evapotranspiration and CO2 flux were investigated across various agronomic considerations, such as irrigation methods (border-check flood and sub-surface), stand life, and herbicide programs. Components of the energy balance, including net radiation, latent heat, ground heat flux, and sensible heat, were evaluated considering correlations to wind speed measured by three sonic anemometers, irrigation frequency, and crop cutting cycle. Comparisons between two different types of radiometers were also carried out. Under drought conditions, we observed higher amounts of evapotranspiration in a field having a stand life of less than two years of age compared to older stands, and in a sub-surface irrigated field compared to flood irrigated fields.

  9. Clinical Age-Specific Seasonal Conjunctivitis Patterns and Their Online Detection in Twitter, Blog, Forum, and Comment Social Media Posts

    Science.gov (United States)

    Deiner, Michael S.; McLeod, Stephen D.; Chodosh, James; Oldenburg, Catherine E.; Fathy, Cherie A.; Lietman, Thomas M.; Porco, Travis C.

    2018-01-01

    Purpose We sought to determine whether big data from social media might reveal seasonal trends of conjunctivitis, most forms of which are nonreportable. Methods Social media posts (from Twitter, and from online forums and blogs) were classified by age and by conjunctivitis type (allergic or infectious) using Boolean and machine learning methods. Based on spline smoothing, we estimated the circular mean occurrence time (a measure of central tendency for occurrence) and the circular variance (a measure of uniformity of occurrence throughout the year, providing an index of seasonality). Clinical records from a large tertiary care provider were analyzed in a similar way for comparison. Results Social media posts machine-coded as being related to infectious conjunctivitis showed similar times of occurrence and degree of seasonality to clinical infectious cases, and likewise for machine-coded allergic conjunctivitis posts compared to clinical allergic cases. Allergic conjunctivitis showed a distinctively different seasonal pattern than infectious conjunctivitis, with a mean occurrence time later in the spring. Infectious conjunctivitis for children showed markedly greater seasonality than for adults, though the occurrence times were similar; no such difference for allergic conjunctivitis was seen. Conclusions Social media posts broadly track the seasonal occurrence of allergic and infectious conjunctivitis, and may be a useful supplement for epidemiologic monitoring. PMID:29450538

  10. Pre- and post-season dietary intake, body composition, and performance indices of NCAA division I female soccer players.

    Science.gov (United States)

    Clark, Mandy; Reed, Debra B; Crouse, Stephen F; Armstrong, Robert B

    2003-09-01

    Little published data describe the dietary and physiological profiles of intercollegiate female soccer players; therefore, the purpose of this investigation was to report baseline dietary data, anthropometrics, and performance indices of soccer women during rigorous pre-season training (2 sessions/day) and then during the post-competitive season. Members of a NCAA Division I women's soccer squad completed 3-day diet records, anthropometrics, and physical tests, including VO2peak. Average body mass was 62 kg with 16% body fat, and no significant pre to post differences were observed. Total energy, carbohydrate (CHO), protein, and fat intakes were significantly greater during the pre-season. Pre-season energy intake met the DRI for females with an "active" lifestyle (37 kcal/kg). While CHO intake failed to meet minimum recommendations to promote glycogen repletion (7-10 g/kg), protein and fat intakes were above minimum recommendations. Pre- and post-season intakes of several micronutrients were marginal (failed to meet minimum CHO and micronutrient recommendations. Foods higher in protein and fat displaced more CHO-rich and nutrient-dense foods within athletes' energy requirements and satiety limits.

  11. Mean surface fields of heat budget components over the warm pool in the Bay of Bengal during post-monsoon season

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.; Rao, D.P.; Rao, B.P.

    Andaman Islands and in the MT area there is an association between SST and Q n . But, off Sri Lanka warmer waters were noticed eventhough Q n was negative. This gives a clue that the role of advection plays a dominant role in the maintenance of SST.... Maintenance of warmwaters could be due to the transport of heat from North to South during post-monsoon season. Individual contributions from advection and air-sea fluxes towards SST would throw better light on the formation of warm pool in Bay of Bengal...

  12. Soil Microbial Activity Responses to Fire in a Semi-arid Savannah Ecosystem Pre- and Post-Monsoon Season

    Science.gov (United States)

    Jimenez, J. R.; Raub, H. D.; Jong, E. L.; Muscarella, C. R.; Smith, W. K.; Gallery, R. E.

    2017-12-01

    Extracellular enzyme activities (EEA) of soil microorganisms can act as important proxies for nutrient limitation and turnover in soil and provide insight into the biochemical requirements of microbes in terrestrial ecosystems. In semi-arid ecosystems, microbial activity is influenced by topography, disturbances such as fire, and seasonality from monsoon rains. Previous studies from forest ecosystems show that microbial communities shift to similar compositions after severe fires despite different initial conditions. In semi-arid ecosystems with high spatial heterogeniety, we ask does fire lead to patch intensification or patch homogenization and how do monsoon rains influence the successional trajectories of microbial responses? We analyzed microbial activity and soil biogeochemistry throughout the monsoon season in paired burned and unburned sites in the Santa Rita Experimental Range, AZ. Surface soil (5cm) from bare-ground patches, bole, canopy drip line, and nearby grass patches for 5 mesquite trees per site allowed tests of spatiotemporal responses to fire and monsoon rain. Microbial activity was low during the pre-monsoon season and did not differ between the burned and unburned sites. We found greater activity near mesquite trees that reflects soil water and nutrient availability. Fire increased soil alkalinity, though soils near mesquite trees were less affected. Soil water content was significantly higher in the burned sites post-monsoon, potentially reflecting greater hydrophobicity of burned soils. Considering the effects of fire in these semi-arid ecosystems is especially important in the context of the projected changing climate regime in this region. Assessing microbial community recovery pre-, during, and post-monsoon is important for testing predictions about whether successional pathways post-fire lead to recovery or novel trajectories of communities and ecosystem function.

  13. Statistical post-processing of seasonal multi-model forecasts: Why is it so hard to beat the multi-model mean?

    Science.gov (United States)

    Siegert, Stefan

    2017-04-01

    Initialised climate forecasts on seasonal time scales, run several months or even years ahead, are now an integral part of the battery of products offered by climate services world-wide. The availability of seasonal climate forecasts from various modeling centres gives rise to multi-model ensemble forecasts. Post-processing such seasonal-to-decadal multi-model forecasts is challenging 1) because the cross-correlation structure between multiple models and observations can be complicated, 2) because the amount of training data to fit the post-processing parameters is very limited, and 3) because the forecast skill of numerical models tends to be low on seasonal time scales. In this talk I will review new statistical post-processing frameworks for multi-model ensembles. I will focus particularly on Bayesian hierarchical modelling approaches, which are flexible enough to capture commonly made assumptions about collective and model-specific biases of multi-model ensembles. Despite the advances in statistical methodology, it turns out to be very difficult to out-perform the simplest post-processing method, which just recalibrates the multi-model ensemble mean by linear regression. I will discuss reasons for this, which are closely linked to the specific characteristics of seasonal multi-model forecasts. I explore possible directions for improvements, for example using informative priors on the post-processing parameters, and jointly modelling forecasts and observations.

  14. Four Weeks of Off-Season Training Improves Peak Oxygen Consumption in Female Field Hockey Players

    Directory of Open Access Journals (Sweden)

    Lindsey T. Funch

    2017-11-01

    Full Text Available The purpose of the study was to examine the changes in peak oxygen consumption ( V ˙O2peak and running economy (RE following four-weeks of high intensity training and concurrent strength and conditioning during the off-season in collegiate female field hockey players. Fourteen female student-athletes (age 19.29 ± 0.91 years were divided into two training groups, matched from baseline V ˙O2peak: High Intensity Training (HITrun; n = 8 and High Intensity Interval Training (HIIT; n = 6. Participants completed 12 training sessions. HITrun consisted of 30 min of high-intensity running, while HIIT consisted of a series of whole-body high intensity Tabata-style intervals (75–85% of age predicted maximum heart rate for a total of four minutes. In addition to the interval training, the off-season training included six resistance training sessions, three team practices, and concluded with a team scrimmage. V ˙O2peak was measured pre- and post-training to determine the effectiveness of the training program. A two-way mixed (group × time ANOVA showed a main effect of time with a statistically significant difference in V ˙O2peak from pre- to post-testing, F(1, 12 = 12.657, p = 0.004, partial η2 = 0.041. Average (±SD V ˙O2peak increased from 44.64 ± 3.74 to 47.35 ± 3.16 mL·kg−1·min−1 for HIIT group and increased from 45.39 ± 2.80 to 48.22 ± 2.42 mL·kg−1·min−1 for HITrun group. Given the similar improvement in aerobic power, coaches and training staff may find the time saving element of HIIT-type conditioning programs attractive.

  15. Seasonal Variations in Physical Fitness and Performance Indices of Elite Soccer Players

    Directory of Open Access Journals (Sweden)

    Yoav Meckel

    2018-02-01

    Full Text Available The aim of the study was to investigate seasonal variations in fitness and performance indices of professional male soccer players. Eighteen professional male soccer players (age range 22–32 years completed three similar sets of tests at three stages of the season: before preseason; after preseason and the middle of the competitive in-season. A significant decrease in body mass and percent fat was found during the preseason. A significant improvement (p < 0.05 was found in the vertical jump (preseason: 37.0 ± 5.3, post-preseason: 39.0 ± 4.8, mid-season: 40.3 ± 5.5 cm, the 4 × 10-m agility test (preseason: 8.1 ± 0.2, post-preseason: 7.9 ± 0.2, mid-season: 8.1 ± 0.3 s, flexibility (preseason: 45.2 ± 8.8, post-preseason: 48.2 ± 7.0, mid-season: 49.9 ± 6.9 cm and aerobic capacity (preseason: 52.7 ± 6.6, post-preseason: 56.4 ± 6.0, mid-season: 57.4 ± 5.4 mL/kg/min during preseason, with no further change during mid-season. Repeated sprint test (RST (6 × 30-m performance indices showed significant deterioration (p < 0.05 in ideal sprint time (IS; preseason: 21.8 ± 1.0, post-preseason: 23.0 ± 0.8, mid-season: 23.2 ± 0.8 s and total sprint time (TS; preseason: 22.5 ± 0.7, post-preseason: 23.5 ± 0.6, mid-season: 23.8 ± 0.6 s during preseason, with no further changes during mid-season. However, performance decrement (PD significantly decreased during the preseason with no change during mid-season. The findings suggest that while power training was probably responsible for the anaerobic fitness improvement, the high-volume training led to improvement in aerobic fitness during the preseason. However, the low-intensity aerobic-type training, coupled with the high total training load, may have led to fatigue and decreases in IS and TS during the preseason.

  16. Observations and modeling of post-midnight uplifts near the magnetic equator

    Directory of Open Access Journals (Sweden)

    M. J. Nicolls

    2006-07-01

    Full Text Available We report here on post-midnight uplifts near the magnetic equator. We present observational evidence from digital ionosondes in Brazil, a digisonde in Peru, and other measurements at the Jicamarca Radio Observatory that show that these uplifts occur fairly regularly in the post-midnight period, raising the ionosphere by tens of kilometers in the most mild events and by over a hundred kilometers in the most severe events. We show that in general the uplifts are not the result of a zonal electric field reversal, and demonstrate instead that the uplifts occur as the ionospheric response to a decreasing westward electric field in conjunction with sufficient recombination and plasma flux. The decreasing westward electric field may be caused by a change in the wind system related to the midnight pressure bulge, which is associated with the midnight temperature maximum. In order to agree with observations from Jicamarca and Palmas, Brazil, it is shown that there must exist sufficient horizontal plasma flux associated with the pressure bulge. In addition, we show that the uplifts may be correlated with a secondary maximum in the spread-F occurrence rate in the post-midnight period. The uplifts are strongly seasonally dependent, presumably according to the seasonal dependence of the midnight pressure bulge, which leads to the necessary small westward field in the post-midnight period during certain seasons. We also discuss the enhancement of the uplifts associated with increased geomagnetic activity, which may be related to disturbance dynamo winds. Finally, we show that it is possible using simple numerical techniques to estimate the horizontal plasma flux and the vertical drift velocity from electron density measurements in the post-midnight period.

  17. The Rate of Seasonal Changes in Temperature Alters Acclimation of Performance under Climate Change.

    Science.gov (United States)

    Nilsson-Örtman, Viktor; Johansson, Frank

    2017-12-01

    How the ability to acclimate will impact individual performance and ecological interactions under climate change remains poorly understood. Theory predicts that the benefit an organism can gain from acclimating depends on the rate at which temperatures change relative to the time it takes to induce beneficial acclimation. Here, we present a conceptual model showing how slower seasonal changes under climate change can alter species' relative performance when they differ in acclimation rate and magnitude. To test predictions from theory, we performed a microcosm experiment where we reared a mid- and a high-latitude damselfly species alone or together under the rapid seasonality currently experienced at 62°N and the slower seasonality predicted for this latitude under climate change and measured larval growth and survival. To separate acclimation effects from fixed thermal responses, we simulated growth trajectories based on species' growth rates at constant temperatures and quantified how much and how fast species needed to acclimate to match the observed growth trajectories. Consistent with our predictions, the results showed that the midlatitude species had a greater capacity for acclimation than the high-latitude species. Furthermore, since acclimation occurred at a slower rate than seasonal temperature changes, the midlatitude species had a small growth advantage over the high-latitude species under the current seasonality but a greater growth advantage under the slower seasonality predicted for this latitude under climate change. In addition, the two species did not differ in survival under the current seasonality, but the midlatitude species had higher survival under the predicted climate change scenario, possibly because rates of cannibalism were lower when smaller heterospecifics were present. These findings highlight the need to incorporate acclimation rates in ecological models.

  18. Influence of seasonal changes and vigor on appearance of trees

    International Nuclear Information System (INIS)

    Miura, T.; Tobioka, J.

    1995-01-01

    The seasonal changes in trees are highly dependant on their health and growth rate. Monitoring the vigor of trees at every season provides basic data which can be used at trees planting to predict the physiological characteristics of their seasonal change. In this study, 3 kinds of trees ; zelkova, camphor and metasequoia were monthly observed from April to December, using an infrared television camera. The vigor of the trees was evaluated in each season and the relationship between their image and the evaluation in each season was investigated. The data shows that there is a high correlation between the vigor and the seasonal evaluations

  19. Effects of seasonal meteorological variables on E. coli persistence in livestock faeces and implications for environmental and human health.

    Science.gov (United States)

    Oliver, David M; Page, Trevor

    2016-11-15

    Agriculture contributes significant volumes of livestock faeces to land. Understanding how faecal microbes respond to shifts in meteorological patterns of contrasting seasons is important in order to gauge how environmental (and human health) risks may alter under a changing climate. The aim of this study was to: (i) quantify the temporal pattern of E. coli growth within dairy faeces post defecation; and (ii) derive E. coli seasonal population change profiles associated with contrasting environmental drivers. Evaluation of the die-off dynamics of E. coli revealed that a treatment mimicking drought and warming conditions significantly enhanced persistence relative to E. coli in faeces that were exposed to field conditions, and that this pattern was consistent across consecutive years. The internal temperature of faeces was important in driving the rate of change in the E. coli population in the immediate period post defecation, with most E. coli activity (as either die-off or growth) occurring at low dry matter content. This study highlighted that the use of seasonal E. coli persistence profiles should be approached with caution when modelling environmental and human health risks given the increased likelihood of atypical seasonal meteorological variables impacting on E. coli growth and die-off.

  20. Spatial and temporal changes in seasonal range attributes in a declining barren-ground caribou herd

    Directory of Open Access Journals (Sweden)

    John A. Virgl

    2017-05-01

    Full Text Available From 1996 to 2015 the Bathurst caribou herd has declined from approximately 349,000 to 20,000 animals. Aboriginal traditional knowledge (TK has recently observed the later arrival of the herd below the treeline, an attribute of the autumn range. Science also predicts that seasonal range attributes (e.g., area, location likely vary with population size, and perhaps climate. We used Aboriginal TK and science to identify several seasonal range attributes that were ex­amined for changes through time (decreasing population abundance. Attributes of seasonal ranges for female Bathurst caribou were calculated using satellite radio-collar data from January 1996 through October 2013. Climate data from CircumArctic Rangifer Monitoring and Assessment Network were analyzed for trends from 1979 to 2009. Analyses showed a significant decrease in the area of post-calving and autumn ranges, but no changes in winter and spring ranges. Results supported Aboriginal TK that female caribou have shifted the autumn range farther from the treeline and moved into the forest later in the year. Analysis of climate variables found no trends at the spatio-temporal scale of the post-calving to autumn ranges. Working hypotheses to explain these patterns, which are not mutually exclusive, include reduced predation risk, increased use of core areas at lower population density, and greater utilization of areas of taiga where arboreal and ground lichen availability and accessibility are relatively higher than in the forest. This analysis demonstrates how including Aboriginal TK can lead to stronger connections and results, with potential to provide new and different insights for further investigations.

  1. Seasonal climate change patterns due to cumulative CO2 emissions

    Science.gov (United States)

    Partanen, Antti-Ilari; Leduc, Martin; Damon Matthews, H.

    2017-07-01

    Cumulative CO2 emissions are near linearly related to both global and regional changes in annual-mean surface temperature. These relationships are known as the transient climate response to cumulative CO2 emissions (TCRE) and the regional TCRE (RTCRE), and have been shown to remain approximately constant over a wide range of cumulative emissions. Here, we assessed how well this relationship holds for seasonal patterns of temperature change, as well as for annual-mean and seasonal precipitation patterns. We analyzed an idealized scenario with CO2 concentration growing at an annual rate of 1% using data from 12 Earth system models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Seasonal RTCRE values for temperature varied considerably, with the highest seasonal variation evident in the Arctic, where RTCRE was about 5.5 °C per Tt C for boreal winter and about 2.0 °C per Tt C for boreal summer. Also the precipitation response in the Arctic during boreal winter was stronger than during other seasons. We found that emission-normalized seasonal patterns of temperature change were relatively robust with respect to time, though they were sub-linear with respect to emissions particularly near the Arctic. Moreover, RTCRE patterns for precipitation could not be quantified robustly due to the large internal variability of precipitation. Our results suggest that cumulative CO2 emissions are a useful metric to predict regional and seasonal changes in precipitation and temperature. This extension of the TCRE framework to seasonal and regional climate change is helpful for communicating the link between emissions and climate change to policy-makers and the general public, and is well-suited for impact studies that could make use of estimated regional-scale climate changes that are consistent with the carbon budgets associated with global temperature targets.

  2. ASSOCIATIONS BETWEEN SEASONAL SLEEP CHANGE AND INDOOR TANNING1,2

    Science.gov (United States)

    CULNAN, ELIZABETH; KLOSS, JACQUELINE D.; DARLOW, SUSAN; HECKMAN, CAROLYN J.

    2015-01-01

    Summary Identification of risk factors for indoor tanning may ultimately aid the development of better indoor tanning prevention strategies, which is pertinent given the association between indoor tanning and skin cancer. This study aimed to examine the relationship between seasonal sleep change and indoor tanning. Women tanners (N= 139) completed self-report measures including items relating to seasonal sleep changes, seasonal affective disorder (SAD), reasons for tanning, tanning during the winter months, and the Tanning Pathology Scale (TAPS), which measures problematic tanning motives and symptoms of tanning dependence. It was hypothesized that seasonal sleep change and SAD would be associated with greater indoor tanning during the winter, more tanning to improve mood and to relax, and higher scores on the TAPS. Findings indicated that more seasonal sleep change was associated with tanning to improve mood and higher scores on the TAPS. Similarly, the presence of SAD was related to tanning to improve mood, tanning to relax, and more problematic tanning. PMID:25730744

  3. Does river restoration affect diurnal and seasonal changes to surface water quality? A study along the Thur River, Switzerland

    International Nuclear Information System (INIS)

    Chittoor Viswanathan, Vidhya; Molson, John; Schirmer, Mario

    2015-01-01

    Changes in river water quality were investigated along the lower reach of the Thur River, Switzerland, following river restoration and a summer storm event. River restoration and hydrological storm events can each cause dramatic changes to water quality by affecting various bio-geochemical processes in the river, but have to date not been well documented, especially in combination. Evaluating the success of river restoration is often restricted in large catchments due to a lack of high frequency water quality data, which are needed for process understanding. These challenges were addressed in this study by measuring water quality parameters including dissolved oxygen (DO), temperature, pH, electrical conductivity (EC), nitrate and dissolved organic carbon (DOC) with a high temporal frequency (15 min–1 h) over selected time scales. In addition, the stable isotopes of water (δD and δ 18 O-H 2 O) as well as those of nitrate (δ 15 N-NO 3 − and δ 18 O-NO 3 − ) were measured to follow changes in water quality in response to the hydrological changes in the river. To compare the spatial distribution of pre- and post-restoration water quality, the sampling stations were chosen upstream and downstream of the restored section. The diurnal and seasonal changes were monitored by conducting 24-hour campaigns in three seasons (winter, summer and autumn) in 2012 and 2013. The amplitude of the diurnal changes of the various observed parameters showed significant seasonal and spatial variability. Biological processes — mainly photosynthesis and respiration — were found to be the major drivers of these diurnal cycles. During low flow in autumn, a reduction of nitrate (attributed to assimilation by autotrophs) in the pre-dawn period and a production of DOC during the daytime (attributed to photosynthesis) were observed downstream of the restored site. Further, a summer storm event was found to override the influence of these biological processes that control the diurnal

  4. An upper tropospheric ‘ozone river’ from Africa to India during the 2008 Asian post-monsoon season

    Directory of Open Access Journals (Sweden)

    Flore Tocquer

    2015-03-01

    Full Text Available We have used ozone data from the Infrared Atmospheric Sounding Interferometer to follow an event of ozone-enriched air-masses in the upper troposphere from eastern Africa to northern India. The ozone transport (hereafter called ‘ozone river’ or O3R occurred during the Asian post-monsoon season in 2008 and was associated with Rossby wave propagation. The persistence of the O3R in a narrow channel was confirmed by MOZAIC airborne data over the northwestern Indian coast. The regions of origin of the O3R were identified by a transport analysis based on the Lagrangian model FLEXPART. The Lagrangian simulations combined with potential vorticity fields indicate that stratospheric intrusions are not likely to be the most important contributor to the observed O3 enhancements. A high-resolution Eulerian model, Meso-NH, with tagged tracers was used to discriminate between African biomass burning, lightnings and Indian anthropogenic pollution as potential sources of precursors for the O3R. Lightning NOx emissions, associated with convective clouds over Africa, were found to be the principal contributor to the ozone enhancement over the Indian Ocean taking advantage of a northeastward jet. This case study illustrates African lightning emissions as an important source for enhanced O3 in the upper troposphere over the Indian Ocean region during the post-monsoon season.

  5. Biodiversity and Seasonal Changes of the Microbiome in Chernozem Agroecosystem

    Science.gov (United States)

    Kutovaya, Olga; Chernov, Timofey; Tkhakakhova, Azida; Ivanova, Ekaterina

    2016-04-01

    Studies of the influence of different agricultural technologies on the soil microbiome are widespread; they are important for understanding the dependence of the microbiome on environmental and soil factors and solution of practical problems related to the control of biochemical processes in soils used in agriculture. The seasonal variability (spring-summer-autumn) of the taxonomic structure of prokaryotic microbiomes in chernozems was studied using sequencing of the 16S rRNA gene. The DNA preparation was used as the matrix for a polymerase chain reaction with the use of a pair of universal primers to the variable region V4 of the 16S rRNA gene - F515 (GTGCCAGCMGCCGCGGTAA) and R806 (GGACTACVSGGGTATCTAAT). The preparation of the samples and sequencing were made on a GS Junior. The samples were collected from the topsoil (0-20 cm) horizons of a long-term fallow and croplands differing in the rates of application of mineral fertilizers (NPK). The results of the weighted UniFrac analysis show that the microbiomes of the fallow and field were distinctly distinguished and that the type of land use significantly affected the structure of the microbial community. The most sensitive to the type of land use were the representatives of the Firmicutes, Gemmatiomonades, and Verrucomicrobia phyla. The type of vegetation and aeration of the root-dwelling soil layer seem to be key factors of this influence. The microbiomes analyzed also differed by seasons: in the autumn samples, they were closer to the spring ones than to the summer ones. This fact evidences that the seasonal differences in the microbiomes are not simple gradual temporal changes; they reflect the influence of some ecological factors transforming the phylogenetic structure of prokaryotic communities. As the seasonal shift was equally expressed in the microbiomes of the field and fallow, it is logical to assume that it was caused by the factors common for two systems of land use. Statistically sensitive to seasonal

  6. Future climate change enhances rainfall seasonality in a regional model of western Maritime Continent

    Science.gov (United States)

    Kang, Suchul; Im, Eun-Soon; Eltahir, Elfatih A. B.

    2018-03-01

    In this study, future changes in rainfall due to global climate change are investigated over the western Maritime Continent based on dynamically downscaled climate projections using the MIT Regional Climate Model (MRCM) with 12 km horizontal resolution. A total of nine 30-year regional climate projections driven by multi-GCMs projections (CCSM4, MPI-ESM-MR and ACCESS1.0) under multi-scenarios of greenhouse gases emissions (Historical: 1976-2005, RCP4.5 and RCP8.5: 2071-2100) from phase 5 of the Coupled Model Inter-comparison Project (CMIP5) are analyzed. Focusing on dynamically downscaled rainfall fields, the associated systematic biases originating from GCM and MRCM are removed based on observations using Parametric Quantile Mapping method in order to enhance the reliability of future projections. The MRCM simulations with bias correction capture the spatial patterns of seasonal rainfall as well as the frequency distribution of daily rainfall. Based on projected rainfall changes under both RCP4.5 and RCP8.5 scenarios, the ensemble of MRCM simulations project a significant decrease in rainfall over the western Maritime Continent during the inter-monsoon periods while the change in rainfall is not relevant during wet season. The main mechanism behind the simulated decrease in rainfall is rooted in asymmetries of the projected changes in seasonal dynamics of the meridional circulation along different latitudes. The sinking motion, which is marginally positioned in the reference simulation, is enhanced and expanded under global climate change, particularly in RCP8.5 scenario during boreal fall season. The projected enhancement of rainfall seasonality over the western Maritime Continent suggests increased risk of water stress for natural ecosystems as well as man-made water resources reservoirs.

  7. Post-fire vegetation behaviour in large burnt scars from 2005 fire season in Spain

    Science.gov (United States)

    Bastos, A.; Gouveia, C. M.; DaCamara, C. C.; Trigo, R. M.

    2012-04-01

    Wildfires have a wide diversity of impacts on landscape which, in turn, depend on the interaction of fire regimes (e.g. intensity, extent, frequency) and the response of vegetation to them in short and long-terms. The increase in erosion rates and the loss of nutrients by runoff in the first months following the fire are among the major impacts of wildfires. A minimum of 30% of vegetation cover is enough to protect soils against erosion but vegetation may require a long period to reach this threshold after severe fires. Since erosion risk is strongly linked to vegetation recovery rates, post-fire vegetation monitoring becomes crucial in land management. Fire regimes in the Mediterranean have been changing in the past decades due to modifications in both socio-economic and climate patterns. Although many vegetation species in Mediterranean ecosystems are adapted to wildfires, changes in fire regime characteristics affect the ability of ecosystems to recover to their previous state. In Spain, fire is an important driver of changes in landscape composition, leading to dominance of shrubland following fire and to a major decrease of pine woodlands (Viedma et al., 2006). Remote sensing is a powerful tool in land management, allowing vegetation monitoring on large spatial scales for relatively long periods of time. In order to assess vegetation dynamics, monthly NDVI data from 1998-2009 from SPOT/VEGETATION at 1km spatial resolution over the Iberian Peninsula were used. This work focuses on 2005 fire season in Spain, which registered the highest amount of burnt area since 1994, with more than 188000 ha burnt. Burnt scars in this fire season were identified by cluster analysis. Post-fire vegetation recovery was assessed based on the monoparametric model developed by Gouveia et al. (2010) that was applied to four large scars located in different geographical settings with different land cover characteristics. While the two northern regions presented fast recovery, in the

  8. Changes in field workability and drought risk from projected climate change drive spatially variable risks in Illinois cropping systems.

    Directory of Open Access Journals (Sweden)

    Bradley J Tomasek

    Full Text Available As weather patterns become more volatile and extreme, risks introduced by weather variability will become more critical to agricultural production. The availability of days suitable for field work is driven by soil temperature and moisture, both of which may be altered by climate change. We projected changes in Illinois season length, spring field workability, and summer drought risk under three different emissions scenarios (B1, A1B, and A2 down to the crop district scale. Across all scenarios, thermal time units increased in parallel with a longer frost-free season. An increase in late March and Early April field workability was consistent across scenarios, but a decline in overall April through May workable days was observed for many cases. In addition, summer drought metrics were projected to increase for most scenarios. These results highlight how the spatial and temporal variability in climate change may present unique challenges to mitigation and adaptation efforts.

  9. ASSOCIATIONS BETWEEN SEASONAL SLEEP CHANGE AND INDOOR TANNING1,2

    OpenAIRE

    CULNAN, ELIZABETH; KLOSS, JACQUELINE D.; DARLOW, SUSAN; HECKMAN, CAROLYN J.

    2015-01-01

    Identification of risk factors for indoor tanning may ultimately aid the development of better indoor tanning prevention strategies, which is pertinent given the association between indoor tanning and skin cancer. This study aimed to examine the relationship between seasonal sleep change and indoor tanning. Women tanners (N= 139) completed self-report measures including items relating to seasonal sleep changes, seasonal affective disorder (SAD), reasons for tanning, tanning during the winter ...

  10. Seasonal changes in the European gravity field from GRACE: A comparison with superconducting gravimeters and hydrology model predictions

    Science.gov (United States)

    Hinderer, Jacques; Andersen, Ole; Lemoine, Frank; Crossley, David; Boy, Jean-Paul

    2006-01-01

    This paper is devoted to the investigation of seasonal changes of the Earth's gravity field from GRACE satellites and the comparison with surface gravity measurements in Europe from the Global Geodynamics Project (GGP) sub-network, as well as with recent hydrology models for continental soil moisture and snow. We used gravity maps in Europe retrieved from the initial GRACE monthly solutions spanning a 21-month duration from April 2002 to December 2003 for various truncation levels of the initial spherical harmonic decomposition of the field. The transfer function between satellite-derived and ground gravity changes due to continental hydrology is studied and we also compute the theoretical ratio of gravity versus radial displacement (in μGal/mm) involved in the hydrological loading process. The 'mean' value (averaged in time and in space over Europe) from hydrologic forward modeling is found to be close to -1.0 μGal/mm and we show that this value can be explained by a strong low degree ( n = 5-6) peak in the hydrology amplitude spectrum. The dominant time-variable signal from GRACE is found to be annual with an amplitude and a phase both of which are in fair agreement with predictions in Europe from recent hydrology models. Initial results suggest that all three data sets (GRACE, hydrology and GGP) respond to annual changes in near-surface water in Europe of a few μGal (at length scales of ˜1000 km) that show a high value in winter and a summer minimum. Despite the limited time span of our analysis and the uncertainties in separating purely local effects from regional ones in superconducting gravimeter data, the calibration and validation aspects of the GRACE data processing based on the annual hydrology cycle in Europe are in progress.

  11. IMF BY and the seasonal dependences of the electric field in the inner magnetosphere

    Directory of Open Access Journals (Sweden)

    H. Matsui

    2005-10-01

    Full Text Available It is known that the electric field pattern at high latitudes depends on the polarity of the Y component of the interplanetary magnetic field (IMF BY and season. In this study, we investigate the seasonal and BY dependences in the inner magnetosphere using the perigee (4field perpendicular to the magnetic field, obtained by the electron drift instrument (EDI, which is based on a newly developed technique, well suited for measurement of the electric fields in the inner magnetosphere. These data are sorted by the polarities of IMF BZ and BY, and by seasons or hemispheres. It is demonstrated from our statistics that the electric fields in the inner magnetosphere depend on these quantities. The following three points are inferred: 1 The electric fields exhibit some differences statistically between Cluster locations at the Northern and Southern Hemispheres with the same dipole L and magnetic local time (MLT values and during the same IMF conditions. These differences in the electric fields might result from hemispherical differences in magnetic field geometry and/or those in field-aligned potential difference. 2 The IMF BY and seasonal dependence of the dawnside and duskside electric fields at 4field-aligned current. 3 The nightside electric field in the inner magnetosphere measured by Cluster is often similar to that in the magnetotail lobe. In the future, it will be necessary to incorporate these dependencies on IMF BY and season into a realistic model of the inner magnetospheric convection electric field. Keywords. Magnetospheric physics (Electric fields; Magnetosphere-ionosphere interactions; Solar windmagnetosphere interactions

  12. Influence of bird feces to water quality in paddy fields during winter season

    Science.gov (United States)

    Somura, H.; Takeda, I.; Masunaga, T.; Mori, Y.; Ide, J.

    2009-12-01

    Thousands of migratory birds such as tundra swan came to the paddy fields for overwintering in recent years in the study area. They stayed in paddy fields during night time for sleeping and used around the fields as a feeding ground during day time. During the birds stay, it was observed that water pooled in the paddy fields gradually turned green and gave off a bad smell. In this study, we tried to estimate the influence of the bird’s feces to water quality in the paddy fields. The study area is in the southeastern portion of Matsue City in Shimane Prefecture, Japan. In several paddy fields, puddling procedure was executed after harvesting rice and then water was stored in the paddy fields during winter season. This is because of being easier of farming activities such as weeding next season and of avoiding using pesticide for weeding with rising of environmental awareness. Water in the paddy fields was collected once or twice a month from the target fields and analyzed nitrogen, phosphorus, and organic carbon in 2007. In the study in 2006, as water was sampled once a week and the changes in the water quality had been grasped, we paid attention to behavior of the birds in a day in the field investigation in 2007. The number of the birds was counted once an hour from visible 7 am to 6 pm once a month. In addition to this, fresh feces were sampled from the fields and analyzed the contents of nitrogen, phosphorus, and organic carbon in the feces. As results, average water qualities of TN, TP, and TOC from November 2007 to March 2008 showed very high concentrations compared with a river water concentration used as irrigation water. More than 70% of TN in the water was ammonia nitrogen. Moreover, comparing with a standard fertilizer amount of nitrogen and phosphorus for paddy fields during irrigation period, it was estimated that the amount of nitrogen excreted by the bird’s feces during the winter season was equivalent to the standard fertilizer amount and the

  13. Changes in the seasonality of Arctic sea ice and temperature

    Science.gov (United States)

    Bintanja, R.

    2012-04-01

    Observations show that the Arctic sea ice cover is currently declining as a result of climate warming. According to climate models, this retreat will continue and possibly accelerate in the near-future. However, the magnitude of this decline is not the same throughout the year. With temperatures near or above the freezing point, summertime Arctic sea ice will quickly diminish. However, at temperatures well below freezing, the sea ice cover during winter will exhibit a much weaker decline. In the future, the sea ice seasonal cycle will be no ice in summer, and thin one-year ice in winter. Hence, the seasonal cycle in sea ice cover will increase with ongoing climate warming. This in itself leads to an increased summer-winter contrast in surface air temperature, because changes in sea ice have a dominant influence on Arctic temperature and its seasonality. Currently, the annual amplitude in air temperature is decreasing, however, because winters warm faster than summer. With ongoing summer sea ice reductions there will come a time when the annual temperature amplitude will increase again because of the large seasonal changes in sea ice. This suggests that changes in the seasonal cycle in Arctic sea ice and temperature are closely, and intricately, connected. Future changes in Arctic seasonality (will) have an profound effect on flora, fauna, humans and economic activities.

  14. Seasonal and Temporal Variations of Field-Aligned Currents and Ground Magnetic Deflections During Substorms

    Science.gov (United States)

    Forsyth, C.; Shortt, M.; Coxon, J. C.; Rae, I. J.; Freeman, M. P.; Kalmoni, N. M. E.; Jackman, C. M.; Anderson, B. J.; Milan, S. E.; Burrell, A. G.

    2018-04-01

    Field-aligned currents (FACs), also known as Birkeland currents, are the agents by which energy and momentum are transferred to the ionosphere from the magnetosphere and solar wind. This coupling is enhanced at substorm onset through the formation of the substorm current wedge. Using FAC data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment and substorm expansion phase onsets identified using the Substorm Onsets and Phases from Indices of the Electrojet technique, we examine the Northern Hemisphere FACs in all local time sectors with respect to substorm onset and subdivided by season. Our results show that while there is a strong seasonal dependence on the underlying FACs, the increase in FACs following substorm onset only varies by 10% with season, with substorms increasing the hemispheric FACs by 420 kA on average. Over an hour prior to substorm onset, the dayside currents in the postnoon quadrant increase linearly, whereas the nightside currents show a linear increase starting 20-30 min before onset. After onset, the nightside Region 1, Region 2, and nonlocally closed currents and the SuperMAG AL (SML) index follow the Weimer (1994, https://doi.org/10.1029/93JA02721) model with the same time constants in each season. These results contrast earlier contradictory studies that indicate that substorms are either longer in the summer or decay faster in the summer. Our results imply that, on average, substorm FACs do not change with season but that their relative impact on the coupled magnetosphere-ionosphere system does due to the changes in the underlying currents.

  15. Does river restoration affect diurnal and seasonal changes to surface water quality? A study along the Thur River, Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Chittoor Viswanathan, Vidhya [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and Drinking Water, Überlandstrasse 133, 8600 Dübendorf (Switzerland); Université de Neuchâtel, Centre d' Hydrogéologie et de Géothermie (CHYN), Rue Emile-Argand 11, CH-2000 Neuchâtel (Switzerland); Molson, John [Université Laval, Département de Géologie et Génie Géologique, Québec City, Québec (Canada); Schirmer, Mario [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department of Water Resources and Drinking Water, Überlandstrasse 133, 8600 Dübendorf (Switzerland); Université de Neuchâtel, Centre d' Hydrogéologie et de Géothermie (CHYN), Rue Emile-Argand 11, CH-2000 Neuchâtel (Switzerland)

    2015-11-01

    Changes in river water quality were investigated along the lower reach of the Thur River, Switzerland, following river restoration and a summer storm event. River restoration and hydrological storm events can each cause dramatic changes to water quality by affecting various bio-geochemical processes in the river, but have to date not been well documented, especially in combination. Evaluating the success of river restoration is often restricted in large catchments due to a lack of high frequency water quality data, which are needed for process understanding. These challenges were addressed in this study by measuring water quality parameters including dissolved oxygen (DO), temperature, pH, electrical conductivity (EC), nitrate and dissolved organic carbon (DOC) with a high temporal frequency (15 min–1 h) over selected time scales. In addition, the stable isotopes of water (δD and δ{sup 18}O-H{sub 2}O) as well as those of nitrate (δ{sup 15}N-NO{sub 3}{sup −} and δ{sup 18}O-NO{sub 3}{sup −}) were measured to follow changes in water quality in response to the hydrological changes in the river. To compare the spatial distribution of pre- and post-restoration water quality, the sampling stations were chosen upstream and downstream of the restored section. The diurnal and seasonal changes were monitored by conducting 24-hour campaigns in three seasons (winter, summer and autumn) in 2012 and 2013. The amplitude of the diurnal changes of the various observed parameters showed significant seasonal and spatial variability. Biological processes — mainly photosynthesis and respiration — were found to be the major drivers of these diurnal cycles. During low flow in autumn, a reduction of nitrate (attributed to assimilation by autotrophs) in the pre-dawn period and a production of DOC during the daytime (attributed to photosynthesis) were observed downstream of the restored site. Further, a summer storm event was found to override the influence of these biological

  16. Seasonal changes in mood and behavior are linked to metabolic syndrome.

    Directory of Open Access Journals (Sweden)

    Reeta Rintamäki

    Full Text Available BACKGROUND: Obesity is a major public health problem worldwide. Metabolic syndrome is a risk factor to the cardiovascular diseases. It has been reported that disruptions of the circadian clockwork are associated with and may predispose to metabolic syndrome. METHODOLOGY AND PRINCIPAL FINDINGS: 8028 individuals attended a nationwide health examination survey in Finland. Data were collected with a face-to-face interview at home and during an individual health status examination. The waist circumference, height, weight and blood pressure were measured and samples were taken for laboratory tests. Participants were assessed using the ATP-III criteria for metabolic syndrome and with the Seasonal Pattern Assessment Questionnaire for their seasonal changes in mood and behavior. Seasonal changes in weight in particular were a risk factor of metabolic syndrome, after controlling for a number of known risk and potential confounding factors. CONCLUSIONS AND SIGNIFICANCE: Metabolic syndrome is associated with high global scores on the seasonal changes in mood and behavior, and with those in weight in particular. Assessment of these changes may serve as a useful indicator of metabolic syndrome, because of easy assessment. Abnormalities in the circadian clockwork which links seasonal fluctuations to metabolic cycles may predispose to seasonal changes in weight and to metabolic syndrome.

  17. The seasonal role of field characteristics on seed-eating bird abundances in agricultural landscapes

    Institute of Scientific and Technical Information of China (English)

    Emmanuel ZUFIAURRE; Mariano CODESIDO; Agustín M.ABBA; David BILENCA

    2017-01-01

    In temperate agroecosystems,avian responses in abundance and distribution to landscape attributes may be exacerbated by the coupling of natural seasons and farming practices.We assessed the seasonal roles of field WPe,field use in the surroundings,and distance from a field to the nearest woodlot on the abundance of seed-eating birds in a 225,000 km2 study area in the Pampas of central Argentina.During spring-summer and autumn of 2011-2013,we randomly selected 392 fields and used transect samples to collect data on abundance and presence of seed-eating bird species.We recorded a total of 11,579 individuals belonging to 15 seed-eating bird species.We used generalized lineal mixed models to relate bird abundance to field type,field use in the surroundings,and distance to the nearest woodlot.In spring-summer (breeding season) most bird responses were associated with their nesting requirements.Species that build their nests in trees,such as eared doves Zenaida auriculata,picazuro pigeons Patagioenas picazuro,and monk parakeets Myiopsitta monachus,were more abundant in fields closer to woodlots,whereas grassland yellow-finches Sicalis luteola,which nest at areas with tall grasses,were more abundant in fields with livestock use patches in the field surroundings.In autumn (non-breeding season),most bird responses were associated with foraging and refuge needs.The high abundance of eared doves in crop stubbles and the association of pigeons at field surroundings dominated by croplands or at crop stubbles surrounded by livestock use fields revealed the intimate association of these species to sites with high availability of food resources.In addition,both picazuro pigeons and spot-winged pigeons Patagioenas maculosa were associated with woodlots,which provide suitable roosting sites.Our results show that in temperate agroecosystems,the relationships between field characteristics and seed-eating bird abundances vary with season.

  18. The seasonal role of field characteristics on seed-eating bird abundances in agricultural landscapes

    Science.gov (United States)

    Codesido, Mariano; Abba, Agustín M.; Bilenca, David

    2017-01-01

    Abstract In temperate agroecosystems, avian responses in abundance and distribution to landscape attributes may be exacerbated by the coupling of natural seasons and farming practices. We assessed the seasonal roles of field type, field use in the surroundings, and distance from a field to the nearest woodlot on the abundance of seed-eating birds in a 225,000 km2 study area in the Pampas of central Argentina. During spring-summer and autumn of 2011–2013, we randomly selected 392 fields and used transect samples to collect data on abundance and presence of seed-eating bird species. We recorded a total of 11,579 individuals belonging to 15 seed-eating bird species. We used generalized lineal mixed models to relate bird abundance to field type, field use in the surroundings, and distance to the nearest woodlot. In spring-summer (breeding season) most bird responses were associated with their nesting requirements. Species that build their nests in trees, such as eared doves Zenaida auriculata, picazuro pigeons Patagioenas picazuro, and monk parakeets Myiopsitta monachus, were more abundant in fields closer to woodlots, whereas grassland yellow-finches Sicalis luteola, which nest at areas with tall grasses, were more abundant in fields with livestock use patches in the field surroundings. In autumn (non-breeding season), most bird responses were associated with foraging and refuge needs. The high abundance of eared doves in crop stubbles and the association of pigeons at field surroundings dominated by croplands or at crop stubbles surrounded by livestock use fields revealed the intimate association of these species to sites with high availability of food resources. In addition, both picazuro pigeons and spot-winged pigeons Patagioenas maculosa were associated with woodlots, which provide suitable roosting sites. Our results show that in temperate agroecosystems, the relationships between field characteristics and seed-eating bird abundances vary with season. PMID

  19. Networked web-cameras monitor congruent seasonal development of birches with phenological field observations

    Science.gov (United States)

    Peltoniemi, Mikko; Aurela, Mika; Böttcher, Kristin; Kolari, Pasi; Loehr, John; Karhu, Jouni; Kubin, Eero; Linkosalmi, Maiju; Melih Tanis, Cemal; Nadir Arslan, Ali

    2017-04-01

    Ecosystems' potential to provide services, e.g. to sequester carbon is largely driven by the phenological cycle of vegetation. Timing of phenological events is required for understanding and predicting the influence of climate change on ecosystems and to support various analyses of ecosystem functioning. We established a network of cameras for automated monitoring of phenological activity of vegetation in boreal ecosystems of Finland. Cameras were mounted on 14 sites, each site having 1-3 cameras. In this study, we used cameras at 11 of these sites to investigate how well networked cameras detect phenological development of birches (Betula spp.) along the latitudinal gradient. Birches are interesting focal species for the analyses as they are common throughout Finland. In our cameras they often appear in smaller quantities within dominant species in the images. Here, we tested whether small scattered birch image elements allow reliable extraction of color indices and changes therein. We compared automatically derived phenological dates from these birch image elements to visually determined dates from the same image time series, and to independent observations recorded in the phenological monitoring network from the same region. Automatically extracted season start dates based on the change of green color fraction in the spring corresponded well with the visually interpreted start of season, and field observed budburst dates. During the declining season, red color fraction turned out to be superior over green color based indices in predicting leaf yellowing and fall. The latitudinal gradients derived using automated phenological date extraction corresponded well with gradients based on phenological field observations from the same region. We conclude that already small and scattered birch image elements allow reliable extraction of key phenological dates for birch species. Devising cameras for species specific analyses of phenological timing will be useful for

  20. Neural correlates of behavioural olfactory sensitivity changes seasonally in European starlings.

    Directory of Open Access Journals (Sweden)

    Geert De Groof

    2010-12-01

    Full Text Available Possibly due to the small size of the olfactory bulb (OB as compared to rodents, it was generally believed that songbirds lack a well-developed sense of smell. This belief was recently revised by several studies showing that various bird species, including passerines, use olfaction in many respects of life. During courtship and nest building, male European starlings (Sturnus vulgaris incorporate aromatic herbs that are rich in volatile compounds (e.g., milfoil, Achillea millefolium into the nests and they use olfactory cues to identify these plants. Interestingly, European starlings show seasonal differences in their ability to respond to odour cues: odour sensitivity peaks during nest-building in the spring, but is almost non-existent during the non-breeding season.This study used repeated in vivo Manganese-enhanced MRI to quantify for the first time possible seasonal changes in the anatomy and activity of the OB in starling brains. We demonstrated that the OB of the starling exhibits a functional seasonal plasticity of certain plant odour specificity and that the OB is only able to detect milfoil odour during the breeding season. Volumetric analysis showed that this seasonal change in activity is not linked to a change in OB volume. By subsequently experimentally elevating testosterone (T in half of the males during the non-breeding season we showed that the OB volume was increased compared to controls.By investigating the neural substrate of seasonal olfactory sensitivity changes we show that the starlings' OB loses its ability during the non-breeding season to detect a natural odour of a plant preferred as green nest material by male starlings. We found that testosterone, applied during the non-breeding season, does not restore the discriminatory ability of the OB but has an influence on its size.

  1. Seasonality patterns of mood and behavior in the Old Order Amish.

    Science.gov (United States)

    Patel, Falguni; Postolache, Nadine; Mohyuddin, Hira; Vaswani, Dipika; Balis, Theodora; Raheja, Uttam K; Postolache, Teodor T

    2012-12-01

    Although humans have become partially isolated from physical seasonal environmental changes through artificial lighting and temperature control, seasonal changes in mood and behavior have been described across hemispheres, continents, ethnicities and occupations. The Old Order Amish are more exposed than the general population to environmental seasonal changes both occupationally as well as through their limited use of electric light in the winter and air conditioning in the summer; yet, their seasonal changes in mood and behavior have not been previously studied. The aim of this study was to analyze seasonal patterns in mood and behavior in the Old Order Amish of Lancaster County, Pennsylvania, who returned completed Seasonal Pattern Assessment Questionnaires (SPAQ). Monthly seasonal patterns were analyzed with repeated measures ANOVAs, followed by a post hoc t-test if significant. The χ 2 was used for presence or absence of seasonal patterns for each item. More than 75% of the participants reported at least one seasonal change. More than 75 % endorsed seasonality in "feeling best" but only populations.

  2. Seasonality of food groups and total energy intake: a systematic review and meta-analysis.

    Science.gov (United States)

    Stelmach-Mardas, M; Kleiser, C; Uzhova, I; Peñalvo, J L; La Torre, G; Palys, W; Lojko, D; Nimptsch, K; Suwalska, A; Linseisen, J; Saulle, R; Colamesta, V; Boeing, H

    2016-06-01

    The aim of this systematic review and meta-analysis was to assess the effect of season on food intake from selected food groups and on energy intake in adults. The search process was based on selecting publications listed in the following: Medline, Scopus, Web of Science, Embase and Agris. Food frequency questionnaires, 24-h dietary recalls and food records as methods for assessment of dietary intake were used to assess changes in the consumption of 11 food groups and of energy intake across seasons. A meta-analysis was performed. Twenty-six studies were included. Articles were divided into those reporting data on four seasons (winter, spring, summer and autumn) or on two seasons (pre-and post-harvest). Four of the studies could be utilized for meta-analysis describing changes in food consumption across four season scheme: from winter to spring fruits decreased, whereas vegetables, eggs and alcoholic beverages increased; from spring to summer vegetable consumption further increased and cereals decreased; from summer to autumn fruits and cereals increased and vegetables, meat, eggs and alcoholic beverages decreased; from autumn to winter cereals decreased. A significant association was also found between energy intake and season, for 13 studies reporting energy intake across four seasons (favors winter) and for eight studies across pre- and post-harvest seasons (favors post-harvest). The winter or the post-harvest season is associated with increased energy intake. The intake of fruits, vegetables, eggs, meat, cereals and alcoholic beverages is following a seasonal consumption pattern and at least for these foods season is determinant of intake.

  3. Investigation on seasonal variation of thermal-induced strain in flexible pavements based on field and laboratory measurements

    Directory of Open Access Journals (Sweden)

    Simita Biswas

    2016-09-01

    Full Text Available Pavement temperature variation has a large influence on the structural response of flexible pavements. Daily and seasonal temperature fluctuation causes expansion and contraction of pavement material, which then leads to the generation of thermal strain. In this study, field observation and laboratory tests were conducted to investigate seasonal variation of thermal-induced strain in flexible pavement. Field observations were conducted at the Integrated Road Research Facility (IRRF’s test road in Edmonton, Alberta, Canada, which is fully equipped with structural and environmental monitoring instruments. The main objective of the field study was to compare the variation of thermal-induced strain in warm and cold seasons. Field results indicated that thermal-induced strain is 1.4–2.0 times greater in cold seasons than in warm seasons following the same pavement temperature variations; however, strain generation rate was greater in warm seasons. Laboratory testing of asphalt slab and cylindrical samples produced comparable ratios. Moreover, field observation and laboratory testing showed a similar trend of temperature and thermal strain variations. Keywords: Thermal-induced strain, Asphalt strain gauge, Field observation, Flexible pavement, Laboratory testing, Seasonal variation

  4. Remotely Sensed Northern Vegetation Response to Changing Climate: Growing Season and Productivity Perspective

    Science.gov (United States)

    Ganguly, S.; Park, Taejin; Choi, Sungho; Bi, Jian; Knyazikhin, Yuri; Myneni, Ranga

    2016-01-01

    Vegetation growing season and maximum photosynthetic state determine spatiotemporal variability of seasonal total gross primary productivity of vegetation. Recent warming induced impacts accelerate shifts on growing season and physiological status over Northern vegetated land. Thus, understanding and quantifying these changes are very important. Here, we first investigate how vegetation growing season and maximum photosynthesis state are evolved and how such components contribute on inter-annual variation of seasonal total gross primary productivity. Furthermore, seasonally different response of northern vegetation to changing temperature and water availability is also investigated. We utilized both long-term remotely sensed data to extract larger scale growing season metrics (growing season start, end and duration) and productivity (i.e., growing season summed vegetation index, GSSVI) for answering these questions. We find that regionally diverged growing season shift and maximum photosynthetic state contribute differently characterized productivity inter-annual variability and trend. Also seasonally different response of vegetation gives different view of spatially varying interaction between vegetation and climate. These results highlight spatially and temporally varying vegetation dynamics and are reflective of biome-specific responses of northern vegetation to changing climate.

  5. A contemporary decennial global sample of changing agricultural field sizes

    Science.gov (United States)

    White, E.; Roy, D. P.

    2011-12-01

    In the last several hundred years agriculture has caused significant human induced Land Cover Land Use Change (LCLUC) with dramatic cropland expansion and a marked increase in agricultural productivity. The size of agricultural fields is a fundamental description of rural landscapes and provides an insight into the drivers of rural LCLUC. Increasing field sizes cause a subsequent decrease in the number of fields and therefore decreased landscape spatial complexity with impacts on biodiversity, habitat, soil erosion, plant-pollinator interactions, diffusion of disease pathogens and pests, and loss or degradation in buffers to nutrient, herbicide and pesticide flows. In this study, globally distributed locations with significant contemporary field size change were selected guided by a global map of agricultural yield and literature review and were selected to be representative of different driving forces of field size change (associated with technological innovation, socio-economic conditions, government policy, historic patterns of land cover land use, and environmental setting). Seasonal Landsat data acquired on a decadal basis (for 1980, 1990, 2000 and 2010) were used to extract field boundaries and the temporal changes in field size quantified and their causes discussed.

  6. Automatic Weather Station (AWS Program operated by the University of Wisconsin-Madison during the 2012-2013 field season: Challenges and Successes

    Directory of Open Access Journals (Sweden)

    Matthew A. Lazzara

    2015-03-01

    Full Text Available This report reviews 2012-2013 field season activities of the University of Wisconsin-Madison's Antarctic Automatic Weather Station (AWS program, summarizes the science that these sites are supporting, and outlines the factors that impact the number of AWS sites serviced in any given field season. The 2012-2013 austral summer season was unusual in the AWS network history. Challenges encountered include, but are not limited to, warmer than normal conditions in the Ross Island area impacting airfield operations, changes to logistical procedures, and competition for shared resources. A flexible work plan provides the best means for taking on these challenges while maximizing AWS servicing efforts under restricted conditions and meeting the need for routine servicing that maintaining an autonomous observing network demands.

  7. On jointly optimising the changes of seasonable goods and inventory replenishment

    Science.gov (United States)

    Li, Zhaolin; Tao, Feng; Sun, Daewon

    2012-06-01

    Retailers often need to replace soon-to-be-unseasonable products with new seasonable goods when the season changes. The trade-off for such activities involves choosing between the salvage loss of the unseasonable product and the profit of selling the seasonable product early. This article develops a periodic-review inventory model for planning the changes of seasonable goods with state-dependent demand and cost parameters. We show that the single-period optimal policy for product changes is a threshold policy based on the initial inventory of the unseasonable goods. The corresponding optimal inventory policy follows a Purchase-Keep-Dispose policy if the incumbent product is kept or a base-stock policy if the incumbent product is replaced. Numerically, we find that the structure of the multi-period optimal policy resembles that of the single-period model. We propose a heuristic to solve the multi-period model and demonstrate its effectiveness. Our research provides insights into dynamically managing seasonable goods.

  8. Effectiveness of in-season manager changes in English Premier League Football

    NARCIS (Netherlands)

    Besters, Lucas; van Ours, Jan; van Tuijl, Martin

    We analyze the performance effects of in-season manager changes in English Premier League football during the seasons 2000/2001–2014/2015. We find that some managerial changes are successful, while others are counterproductive. On average, performance does not improve following a managerial

  9. Seasonal changes in body composition of inter-county Gaelic Athletic Association hurlers.

    Science.gov (United States)

    Davies, Robert W; Toomey, Clodagh; McCormack, William; O'Neill, Cian; Hughes, Katie; Jakeman, Philip

    2017-12-01

    Longitudinal change in body composition for elite-level inter-county hurlers was reported over a single season and four consecutive seasons. Body composition measured by dual-energy x-ray absorptiometry (DXA) of 66 senior, male, outfield players was obtained. Four successive measurements were taken: off-season (OFF 1 ), pre-season (PRE), mid-season (MID) and the off-season of the following season (OFF 2 ). A subsample of 11 hurlers were measured at all time points over 4 consecutive seasons. DXA-derived estimates of fat and lean mass were normalised to stature for analysis (kg∙m ‒2 ); data are (mean [lower: upper, 95% confidence interval]). A concurrent increase of lean mass (0.31 [0.19: 0.43] kg∙m ‒2 ) and loss of fat mass occurred (-0.38 [-0.50: -0.26] kg∙m ‒2 ) OFF 1 to PRE. Lean mass accrual was maintained PRE to OFF 2 while the initial loss of fat mass was restored MID to OFF 2 (0.52 [0.40: 0.64] kg ∙ m ‒2 ), with the trunk acting as the primary region of change. Over the four seasons, a net increase of lean mass was observed (~ 0.9 [0.4: 1.4] kg per annum) with a negligible overall change for fat mass over time. However, the cycling of fat mass (OFF to PRE and MID to OFF) within each season was recurrent season-to-season.

  10. Seasonal mood changes in patients with obsessive-compulsive disorder.

    Science.gov (United States)

    Tan, Oğuz; Metin, Barış; Ünsalver, Barış Önen; Sayar, Gökben Hızlı

    2017-12-01

    Obsessive-compulsive disorder (OCD) is frequently associated with mood disorders. However, to date, the co-occurrence of OCD with seasonal affective disorder (SAD) has not been investigated. We have aimed to estimate the prevalence of seasonal mood changes in patients with OCD and explore the contribution of seasonality in mood to the severity of OCD. The Seasonal Pattern Assessment Questionnaire (SPAQ), the Yale-Brown Obsession and Compulsion Scale (Y-BOCS), the Hamilton Depression Rating Scale-17 Items (HDRS-17), and the Beck Anxiety Inventory (BAI) were administered to patients with OCD (n=104) and controls (n=125). The degree of seasonality was measured by the Global Seasonality Score (GSS) calculated from the SPAQ. SAD and subsyndromal seasonal affective disorder (S-SAD) were significantly more prevalent in patients with OCD (53%, n=55) than controls (25%, n=31). When patients were assessed in the season in which SAD occurs, depression and compulsions (but not obsessions, OCD or anxiety) were more severe than those assessed in a season during which SAD does not occur. SAD frequently co-occurs with OCD and, given this co-occurrence, depression symptoms in some patients with OCD might be expected to vary on a seasonal basis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Relationship between summer monsoon rainfall and cyclogenesis over Bay of Bengal during post-monsoon (October-December) season

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y; Maneesha, K.

    peak monsoon (October–November) season and concluded that the frequency of cyclones is modulated by negative and positive IOD rather than El-Nino and La-Nina. In this study, the relationship between southwest monsoon rainfall (June–September) and TNDC... Relationship between summer monsoon rainfall and cyclogenesis over Bay of Bengal during post-monsoon (October–December) season Y Sadhuram∗ and K Maneesha CSIR–National Institute of Oceanography, 176, Lawsons Bay Colony, Visakhapatnam 530 017, India...

  12. The importance of warm season warming to western U.S. streamflow changes

    Science.gov (United States)

    Das, T.; Pierce, D.W.; Cayan, D.R.; Vano, J.A.; Lettenmaier, D.P.

    2011-01-01

    Warm season climate warming will be a key driver of annual streamflow changes in four major river basins of the western U.S., as shown by hydrological model simulations using fixed precipitation and idealized seasonal temperature changes based on climate projections with SRES A2 forcing. Warm season (April-September) warming reduces streamflow throughout the year; streamflow declines both immediately and in the subsequent cool season. Cool season (October-March) warming, by contrast, increases streamflow immediately, partially compensating for streamflow reductions during the subsequent warm season. A uniform warm season warming of 3C drives a wide range of annual flow declines across the basins: 13.3%, 7.2%, 1.8%, and 3.6% in the Colorado, Columbia, Northern and Southern Sierra basins, respectively. The same warming applied during the cool season gives annual declines of only 3.5%, 1.7%, 2.1%, and 3.1%, respectively. Copyright 2011 by the American Geophysical Union.

  13. Novel Method of Weighting Cumulative Helmet Impacts Improves Correlation with Brain White Matter Changes After One Football Season of Sub-concussive Head Blows.

    Science.gov (United States)

    Merchant-Borna, Kian; Asselin, Patrick; Narayan, Darren; Abar, Beau; Jones, Courtney M C; Bazarian, Jeffrey J

    2016-12-01

    One football season of sub-concussive head blows has been shown to be associated with subclinical white matter (WM) changes on diffusion tensor imaging (DTI). Prior research analyses of helmet-based impact metrics using mean and peak linear and rotational acceleration showed relatively weak correlations to these WM changes; however, these analyses failed to account for the emerging concept that neuronal vulnerability to successive hits is inversely related to the time between hits (TBH). To develop a novel method for quantifying the cumulative effects of sub-concussive head blows during a single season of collegiate football by weighting helmet-based impact measures for time between helmet impacts. We further aim to compare correlations to changes in DTI after one season of collegiate football using weighted cumulative helmet-based impact measures to correlations using non-weighted cumulative helmet-based impact measures and non-cumulative measures. We performed a secondary analysis of DTI and helmet impact data collected on ten Division III collegiate football players during the 2011 season. All subjects underwent diffusion MR imaging before the start of the football season and within 1 week of the end of the football season. Helmet impacts were recorded at each practice and game using helmet-mounted accelerometers, which computed five helmet-based impact measures for each hit: linear acceleration (LA), rotational acceleration (RA), Gadd Severity Index (GSI), Head Injury Criterion (HIC 15 ), and Head Impact Technology severity profile (HITsp). All helmet-based impact measures were analyzed using five methods of summary: peak and mean (non-cumulative measures), season sum-totals (cumulative unweighted measures), and season sum-totals weighted for time between hits (TBH), the interval of time from hit to post-season DTI assessment (TUA), and both TBH and TUA combined. Summarized helmet-based impact measures were correlated to statistically significant changes in

  14. Seasonal changes of CO2, CH4 and N2O fluxes in relation to land-use change in tropical peatlands located in coastal area of South Kalimantan

    International Nuclear Information System (INIS)

    Inubushi, K.; Furukawa, Y.; Hadi, A.; Purnomo, E.; Tsuruta, H.

    2003-01-01

    Tropical peatland could be a source of greenhouse gases emission because it contains large amounts of soil carbon and nitrogen. However these emissions are strongly influenced by soil moisture conditions. Tropical climate is characterized typically by wet and dry seasons. Seasonal changes in the emission of carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) were investigated over a year at three sites (secondary forest, paddy field and upland field) in the tropical peatland in South Kalimantan, Indonesia. The amount of these gases emitted from the fields varied widely according to the seasonal pattern of precipitation, especially methane emission rates were positively correlated with precipitation. Converting from secondary forest peatland to paddy field tended to increase annual emissions of CO 2 and CH 4 to the atmosphere (from 1.2 to 1.5 kg CO 2 -C m -2 y -1 and from 1.2 to 1.9 g CH 4 -C m -2 y -1 ), while changing land-use from secondary forest to upland tended to decrease these gases emissions (from 1.2 to 1.0 kg CO 2 -C m -2 y -1 and from 1.2 to 0.6 g CH 4 -C m -2 y -1 ), but no clear trend was observed for N 2 O which kept negative value as annual rates at three sites. (Author)

  15. Magnitudes and timing of seasonal peak snowpack water equivalents in Arizona: A preliminary study of the possible effects of recent climatic change

    Science.gov (United States)

    Peter F. Ffolliott; Gerald J. Gottfried

    2010-01-01

    Field measurements and computer-based predictions suggest that the magnitudes of seasonal peak snowpack water equivalents are becoming less and the timing of these peaks is occurring earlier in the snowmelt-runoff season of the western United States. These changes in peak snowpack conditions have often been attributed to a warming of the regional climate. To determine...

  16. Seasonal changes in the assembly mechanisms structuring tropical fish communities.

    Science.gov (United States)

    Fitzgerald, Daniel B; Winemiller, Kirk O; Sabaj Pérez, Mark H; Sousa, Leandro M

    2017-01-01

    Despite growing interest in trait-based approaches to community assembly, little attention has been given to seasonal variation in trait distribution patterns. Mobile animals can rapidly mediate influences of environmental factors and species interactions through dispersal, suggesting that the relative importance of different assembly mechanisms can vary over short time scales. This study analyzes seasonal changes in functional trait distributions of tropical fishes in the Xingu River, a major tributary of the Amazon with large predictable temporal variation in hydrologic conditions and species density. Comparison of observed functional diversity revealed that species within wet-season assemblages were more functionally similar than those in dry-season assemblages. Further, species within wet-season assemblages were more similar than random expectations based on null model predictions. Higher functional richness within dry season communities is consistent with increased niche complementarity during the period when fish densities are highest and biotic interactions should be stronger; however, null model tests suggest that stochastic factors or a combination of assembly mechanisms influence dry-season assemblages. These results demonstrate that the relative influence of community assembly mechanisms can vary seasonally in response to changing abiotic conditions, and suggest that studies attempting to infer a single dominant mechanism from functional patterns may overlook important aspects of the assembly process. During the prolonged flood pulse of the wet season, expanded habitat and lower densities of aquatic organisms likely reduce the influence of competition and predation. This temporal shift in the influence of different assembly mechanisms, rather than any single mechanism, may play a large role in maintaining the structure and diversity of tropical rivers and perhaps other dynamic and biodiverse systems. © 2016 by the Ecological Society of America.

  17. Measuring the economic impact of climate change on major South African field crops: a Ricardian approach

    Science.gov (United States)

    Gbetibouo, G. A.; Hassan, R. M.

    2005-07-01

    This study employed a Ricardian model to measure the impact of climate change on South Africa's field crops and analysed potential future impacts of further changes in the climate. A regression of farm net revenue on climate, soil and other socio-economic variables was conducted to capture farmer-adapted responses to climate variations. The analysis was based on agricultural data for seven field crops (maize, wheat, sorghum, sugarcane, groundnut, sunflower and soybean), climate and edaphic data across 300 districts in South Africa. Results indicate that production of field crops was sensitive to marginal changes in temperature as compared to changes in precipitation. Temperature rise positively affects net revenue whereas the effect of reduction in rainfall is negative. The study also highlights the importance of season and location in dealing with climate change showing that the spatial distribution of climate change impact and consequently needed adaptations will not be uniform across the different agro-ecological regions of South Africa. Results of simulations of climate change scenarios indicate many impacts that would induce (or require) very distinct shifts in farming practices and patterns in different regions. Those include major shifts in crop calendars and growing seasons, switching between crops to the possibility of complete disappearance of some field crops from some region.

  18. Normal sperm morphology and changes of semen characteristics and abnormal morphological spermatozoa among peri-mating seasons in captive japanese black bears (Ursus thibetanus japonicus).

    Science.gov (United States)

    Okano, Tsukasa; Murase, Tetsuma; Nakamura, Sachiko; Komatsu, Takeshi; Tsubota, Toshio; Asano, Makoto

    2009-04-01

    The objectives of this study were to obtain morphological data for normal spermatozoa and to investigate seasonal changes (the early, mid- and post-mating seasons) in abnormal morphology of spermatozoa and the characteristics of semen in Japanese black bears. Semen was collected by electroejaculation from 34 captive male Japanese black bears a total of 74 times. Length of head, width of head, length of midpiece and total length of the spermatozoa were 6.3 +/- 0.4, 4.5 +/- 0.3, 10.4 +/- 0.7 and 69.6 +/- 3.1 mum (mean +/- SD; 20 semen, 200 spermatozoa), respectively. In the semen collected during the mid-mating season, ejaculate volume, ejaculate pH, sperm concentration, total sperm count, motility, viability and intact acrosomes were 0.46 +/- 0.36 ml, 7.3 +/- 0.4, 659 +/- 644 x 10(6)/ml, 214 +/- 208 x 10(6), 82.9 +/- 9.6%, 89.3 +/- 9.5% and 97.0 +/- 3.2% (mean +/- SD; n=21, in ejaculate pH n=8), respectively. Sperm motility and viability in the early (n=7) and mid-mating (n=21) seasons were significantly higher than in the post-mating (n=8) season. The rates of detached heads in the early and mid-mating season were significantly lower than in the post-mating season. The main abnormal morphologies observed (mean +/- SD%; n=23) were simply bent tail (19.9 +/- 22.6), distal droplets (13.5 +/- 11.7), proximal droplets (9.6 +/- 7.8), teratoid spermatozoa (6.7 +/- 10.7), knobbed acrosome (4.9 +/- 8.6), acrosome damage (3.7 +/- 2.8) and bent midpiece (3.7 +/- 5.1). The data will be useful for artificial breeding and further research on male reproductive physiology in this species.

  19. Effectiveness of in-season manager changes in English Premier League Football

    OpenAIRE

    Besters, Lucas; van Ours, Jan; van Tuijl, Martin

    2016-01-01

    We analyze the performance effects of in-season manager changes in English Premier League football during the seasons 2000/2001–2014/2015. We find that some managerial changes are successful, while others are counterproductive. On average, performance does not improve following a managerial replacement. The successfulness of managerial turnover depends on specific highly unpredictable circumstances, as we illustrate through case-studies.

  20. Seasonal field metabolic rates of American martens in Wisconsin

    Science.gov (United States)

    Jonathan H. Gilbert; Patrick A Zollner; Adam K. Green; John L. Wright

    2009-01-01

    We report on FMR of free-living American martens (Martes americana) in autumn and winter in northern Wisconsin. Mean body mass was significantly higher in males (1099 ± 43 [S.E.] g) than females (737 ± 28 g), with no significant difference by season. Daily mass change rates of martens did not differ from zero, and mass change rate...

  1. The effect of seasonal changes and climatic factors on suicide attempts of young people.

    Science.gov (United States)

    Akkaya-Kalayci, Türkan; Vyssoki, Benjamin; Winkler, Dietmar; Willeit, Matthaeus; Kapusta, Nestor D; Dorffner, Georg; Özlü-Erkilic, Zeliha

    2017-11-15

    Seasonal changes and climatic factors like ambient temperature, sunlight duration and rainfall can influence suicidal behavior. This study analyses the relationship between seasonal changes and climatic variations and suicide attempts in 2131 young patients in Istanbul, Turkey. In our study sample, there was an association between suicide attempts in youths and seasonal changes, as suicide attempts occurred most frequently during summer in females as well as in males. Furthermore, there was a positive correlation between the mean temperature over the past 10 days and temperature at the index day and suicide attempts in females. After seasonality effects were mathematically removed, the mean temperature 10 days before a suicide attempt remained significant in males only, indicating a possible short-term influence of temperature on suicide attempts. This study shows an association between suicide attempts of young people and climatic changes, in particular temperature changes as well as seasonal changes. Therefore, the influence of seasonal changes and climatic factors on young suicide attempters should get more attention in research to understand the biopsychosocial mechanisms playing a role in suicide attempts of young people. As suicide attempts most frequently occur in young people, further research is of considerable clinical importance.

  2. Seasonal changes in photosynthetic capacity of leaves of kiwifruit (Actinidia deliciosa) vines

    International Nuclear Information System (INIS)

    Buwalda, J.G.; Meekings, J.S.; Smith, G.S.

    1991-01-01

    The seasonal trend of photosynthetic capacity of leaves of kiwifruit (Actinidia deliciosa var. deliciosa) vines growing in the field was examined, by measuring the response of net photosynthesis (A) to irradiance (PAR) at monthly intervals for leaves that emerged at different stages of the growing season. A climate controlled minicuvette system was used, to ensure constant environmental conditions, apart from the controlled changes in leaf irradiance. Responses of A to irradiance were described using asymptotic exponential curves, providing estimates of the radiation saturated rate of A (A sat ), and the response of A to increasing incident PAR at low PAR levels (ϕ i ). The change in photosynthetic capacity with leaf age was similar for leaves emerging 1, 2, 3 or 4 months after bud burst. At 1 month after leaf emergence, when leaves were fully expanded, Asat was 9–11 μmol CO 2 m −2 s −1 . Maximum photosynthetic capacity was not attained until 3–5 months after leaf emergence, when Asat was 16–17 μmol CO 2 m −2 s −1 . The increasing photosynthetic capacity during 3–5 months after leaf emergence was closely related to concomitant changes in leaf N and chlorophyll contents. The possibility that N import to the leaf was a significant factor limiting the development of photosynthetic capacity is discussed. (author)

  3. Impact of climate change on mid-twenty-first century growing seasons in Africa

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Kerry H.; Vizy, Edward K. [The University of Texas at Austin, Department of Geological Sciences, Jackson School of Geosciences, Austin, TX (United States)

    2012-12-15

    Changes in growing seasons for 2041-2060 across Africa are projected using a regional climate model at 90-km resolution, and confidence in the predictions is evaluated. The response is highly regional over West Africa, with decreases in growing season days up to 20% in the western Guinean coast and some regions to the east experiencing 5-10% increases. A longer growing season up to 30% in the central and eastern Sahel is predicted, with shorter seasons in parts of the western Sahel. In East Africa, the short rains (boreal fall) growing season is extended as the Indian Ocean warms, but anomalous mid-tropospheric moisture divergence and a northward shift of Sahel rainfall severely curtails the long rains (boreal spring) season. Enhanced rainfall in January and February increases the growing season in the Congo basin by 5-15% in association with enhanced southwesterly moisture transport from the tropical Atlantic. In Angola and the southern Congo basin, 40-80% reductions in austral spring growing season days are associated with reduced precipitation and increased evapotranspiration. Large simulated reductions in growing season over southeastern Africa are judged to be inaccurate because they occur due to a reduction in rainfall in winter which is over-produced in the model. Only small decreases in the actual growing season are simulated when evapotranspiration increases in the warmer climate. The continent-wide changes in growing season are primarily the result of increased evapotranspiration over the warmed land, changes in the intensity and seasonal cycle of the thermal low, and warming of the Indian Ocean. (orig.)

  4. Four Weeks of Off-Season Training Improves Peak Oxygen Consumption in Female Field Hockey Players

    OpenAIRE

    Lindsey T. Funch; Erik Lind; Larissa True; Deborah Van Langen; John T. Foley; James F. Hokanson

    2017-01-01

    The purpose of the study was to examine the changes in peak oxygen consumption ( V ˙O2peak) and running economy (RE) following four-weeks of high intensity training and concurrent strength and conditioning during the off-season in collegiate female field hockey players. Fourteen female student-athletes (age 19.29 ± 0.91 years) were divided into two training groups, matched from baseline V ˙O2peak: High Intensity Training (HITrun; n = 8) and High Intensity Interval Training (HIIT; ...

  5. Octocorals in a changing environment: Seasonal response of stress biomarkers in natural populations of Veretillum cynomorium

    Science.gov (United States)

    Madeira, Carolina; Madeira, Diana; Vinagre, Catarina; Diniz, Mário

    2015-09-01

    Current concerns about climate change emphasize the need for an accurate monitoring of physiological conditions in wild populations. Therefore, the aims of this work were to a) assess the response of the octocoral Veretillum cynomorium to thermal variation in natural populations during low tide, by quantifying several biochemical indicators of thermal and oxidative stress and b) evaluate the effect of seasonality in the results and the adequacy of the use of biochemical indicators of stress in field monitoring studies in octocorals. Sampling took place during spring (April) and summer (June). Heat shock protein (Hsp70) and ubiquitin (Ub) content, enzyme activities - superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), and lipid peroxidation (LPO) were assessed in rachis and peduncle tissues separately. The results showed significant seasonal fluctuations in the set of biomarkers tested. Differences were detected between spring and summer, with significant decreases in biomarker levels from April to June being a major observed trend. These results suggest that V. cynomorium is thermo-tolerant during summer low tide conditions. Seasonal variation seems to reflect a metabolic suppression strategy and/or may also be related to seasonal changes in food availability and reproductive status. Differences in activity between tissue types were also found significant for GST, LPO and Ub. Biomarker levels were correlated with total protein concentration, but not with wet body weight of the specimens. This study suggests that season influences the expression of biomarkers and must be taken into consideration in the preliminary stages of sampling design for climate change biomonitoring studies. In addition, the results suggest that this octocoral species is likely to survive in future challenging thermal conditions.

  6. Impact of Estrogen Therapy on Lymphocyte Homeostasis and the Response to Seasonal Influenza Vaccine in Post-Menopausal Women.

    Directory of Open Access Journals (Sweden)

    Flora Engelmann

    Full Text Available It is widely recognized that changes in levels of ovarian steroids modulate severity of autoimmune disease and immune function in young adult women. These observations suggest that the loss of ovarian steroids associated with menopause could affect the age-related decline in immune function, known as immune senescence. Therefore, in this study, we determined the impact of menopause and estrogen therapy (ET on lymphocyte subset frequency as well as the immune response to seasonal influenza vaccine in three different groups: 1 young adult women (regular menstrual cycles, not on hormonal contraception; 2 post-menopausal (at least 2 years women who are not receiving any form of hormone therapy (HT and 3 post-menopausal hysterectomized women receiving ET. Although the numbers of circulating CD4 and CD20 B cells were reduced in the post-menopausal group receiving ET, we also detected a better preservation of naïve B cells, decreased CD4 T cell inflammatory cytokine production, and slightly lower circulating levels of the pro-inflammatory cytokine IL-6. Following vaccination, young adult women generated more robust antibody and T cell responses than both post-menopausal groups. Despite similar vaccine responses between the two post-menopausal groups, we observed a direct correlation between plasma 17β estradiol (E2 levels and fold increase in IgG titers within the ET group. These findings suggest that ET affects immune homeostasis and that higher plasma E2 levels may enhance humoral responses in post-menopausal women.

  7. Seasonal Changes in Soccer Players' Body Composition and Dietary Intake Practices.

    Science.gov (United States)

    Devlin, Brooke L; Kingsley, Michael; Leveritt, Michael D; Belski, Regina

    2017-12-01

    Devlin, BL, Kingsley, M, Leveritt, MD, and Belski, R. Seasonal changes in soccer players' body composition and dietary intake practices. J Strength Cond Res 31(12): 3319-3326, 2017-The aims of this study were 2-fold: to determine seasonal changes in dietary intake and body composition in elite soccer players and to evaluate the influence of self-determined individual body composition goals on dietary intake and body composition. This longitudinal, observational study assessed body composition (total mass, fat-free soft tissue mass, and fat mass) using dual-energy x-ray absorptiometry and dietary intake (energy and macronutrients) via multiple-pass 24-hour recalls, at 4 time points over a competitive season in elite soccer players from one professional club in the Australian A-League competition. Self-reported body composition goals were also recorded. Eighteen elite male soccer players took part (25 ± 5 years, 180.5 ± 7.4 cm, 75.6 ± 6.5 kg). Majority (≥67%) reported the goal to maintain weight. Fat-free soft tissue mass increased from the start of preseason (55,278 ± 5,475 g) to the start of competitive season (56,784 ± 5,168 g; p nutrition recommendations. The self-reported body composition goals did not strongly influence dietary intake practices or changes in body composition. This study has demonstrated that body composition changes over the course of a soccer season are subtle in elite soccer players despite relatively low self-reported intake of energy and carbohydrate.

  8. Sustainable biochar effects for low carbon crop production: A 5-crop season field experiment on a low fertility soil from Central China

    Science.gov (United States)

    Liu, X.

    2014-12-01

    Biochar's effects on improving soil fertility, enhancing crop productivity and reducing greenhouse gases (GHGs) emission from croplands had been well addressed in numerous short-term experiments with biochar soil amendment (BSA) mostly in a single crop season / cropping year. However, the persistence of these effects, after a single biochar application, has not yet been well known due to limited long-term field studies so far. Large scale BSA in agriculture is often commented on the high cost due to large amount of biochar in a single application. Here, we try to show the persistence of biochar effects on soil fertility and crop productivity improvement as well as GHGs emission reduction, using data from a field experiment with BSA for 5 crop seasons in central North China. A single amendment of biochar was performed at rates of 0 (C0), 20 (C20) and 40 t ha-1 (C40) before sowing of the first crop season. Emissions of CO2, CH4 and N2O were monitored with static closed chamber method throughout the crop growing season for the 1st, 2nd and 5th cropping. Crop yield was measured and topsoil samples were collected at harvest of each crop season. BSA altered most of the soil physic-chemical properties with a significant increase over control in soil organic carbon (SOC) and available potassium (K) content. The increase in SOC and available K was consistent over the 5 crop seasons after BSA. Despite a significant yield increase in the first maize season, enhancement of crop yield was not consistent over crop seasons without corresponding to the changes in soil nutrient availability. BSA did not change seasonal total CO2 efflux but greatly reduced N2O emissions throughout the five seasons. This supported a stable nature of biochar carbon in soil, which played a consistent role in reducing N2O emission, which showed inter-annual variation with changes in temperature and soil moisture conditions. The biochar effect was much more consistent under C40 than under C20 and with

  9. Applying an energy balance model of a debris covered glacier through the Himalayan seasons - insights from the field and sensitivity analysis

    Science.gov (United States)

    Steiner, Jakob; Pellicciotti, Francesca; Buri, Pascal; Brock, Ben

    2016-04-01

    Although some recent studies have attempted to model melt below debris cover in the Himalaya as well as the European Alps, field measurements remain rare and uncertainties of a number of parameters are difficult to constrain. The difficulty of accurately measuring sub-debris melt at one location over a longer period of time with stakes adds to the challenge of calibrating models adequately, as moving debris tends to tilt stakes. Based on measurements of sub-debris melt with stakes as well as air and surface temperature at the same location during three years from 2012 to 2014 at Lirung Glacier in the Nepalese Himalaya, we investigate results with the help of an earlier developed energy balance model. We compare stake readings to cumulative melt as well as observed to modelled surface temperatures. With timeseries stretching through the pre-Monsoon, Monsoon and post-Monsoon of different years we can show the difference of sensitive parameters during these seasons. Using radiation measurements from the AWS we can use a temporarily variable time series of albedo. A thorough analysis of thermistor data showing the stratigraphy of the temperature through the debris layer allows a detailed discussion of the variability as well as the uncertainty range of thermal conductivity. Distributed wind data as well as results from a distributed surface roughness assessment allows to constrain variability of turbulent fluxes between the different locations of the stakes. We show that model results are especially sensitive to thermal conductivity, a value that changes substantially between the seasons. Values obtained from the field are compared to earlier studies, which shows large differences within locations in the Himalaya. We also show that wind varies with more than a factor two between depressions and on debris mounds which has a significant influence on turbulent fluxes. Albedo decreases from the dry to the wet season and likely has some spatial variability that is

  10. Diurnal and Seasonal Variations in Mid-Latitude Geomagnetic Field During International Quiet Days: BOH Magnetometer

    Directory of Open Access Journals (Sweden)

    Junga Hwang

    2012-12-01

    Full Text Available Korea Astronomy and Space Science Institute researchers have installed and operated magnetometers at Bohyunsan Observatory to measure the Earth's magnetic field variations in South Korea. In 2007, we installed a fluxgate magnetometer (RFP-523C to measure H, D, and Z components of the geomagnetic field. In addition, in 2009, we installed a Overhauser proton sensor to measure the absolute total magnetic field F and a three-axis magneto-impedance sensor for spectrum analysis. Currently three types of magnetometer data have been accumulated. In this paper, we use the H, D, Z components of fluxgate magnetometer data to investigate the characteristics of mid-latitude geomagnetic field variation. To remove the temporary changes in Earth’s geomagnetic filed by space weather, we use the international quiet days’ data only. In other words, we performed a superposed epoch analysis using five days per each month during 2008-2011. We find that daily variations of H, D, and Z shows similar tendency compared to previous results using all days. That is, H, D, Z all three components’ quiet intervals terminate near the sunrise and shows maximum 2-3 hours after the culmination and the quiet interval start from near the sunset. Seasonal variations show similar dependences to the Sun. As it becomes hot season, the geomagnetic field variation’s amplitude becomes large and the quiet interval becomes shortened. It is well-known that these variations are effects of Sq current system in the Earth’s atmosphere. We confirm that the typical mid-latitude geomagnetic field variations due to the Sq current system by excluding all possible association with the space weather.

  11. The impact of seasonal rice price changes on rice self-consumption in farm household of rural Java

    Science.gov (United States)

    Ani, S. W.; Antriyandarti, E.

    2018-03-01

    Seasonal rice price changes are very volatile and not predictable. This price changes have a heterogeneous impact on public consumption. The problem of seasonal rice price changes is not only experienced by consumers, but also in the farmers side as producers. The objective of this study is to provide a detail overview and description of the changing seasonal rice self-consumption of farm households in rural Java in response to seasonal rice price changes and income shocks to anticipate seasonal scarcity. This paper constructs a theoretical model to address such seasonality of food deprivation by using one year of seasonally farm household panel data, empirically tests the extent to which farmers in rural Java can smooth their rice self-consumption from season to season in response to income shocks. The result shows that rice farmers increase their rice self-consumption when prices are high.

  12. Compensatory Changes in Energy Balance Regulation over One Athletic Season.

    Science.gov (United States)

    Silva, Analiza M; Matias, Catarina N; Santos, Diana A; Thomas, Diana; Bosy-Westphal, Anja; MüLLER, Manfred J; Heymsfield, Steven B; Sardinha, LUíS B

    2017-06-01

    Mechanisms in energy balance (EB) regulation may include compensatory changes in energy intake (EI) and metabolic adaption (MA), but information is unavailable in athletes who often change EB components. We aim to investigate EB regulation compensatory mechanisms over one athletic season. Fifty-seven athletes (39 males/18 females; handball, volleyball, basketball, triathlon, and swimming) were evaluated from the beginning to the competitive phase of the season. Resting and total energy expenditure (REE and TEE, respectively) were assessed by indirect calorimetry and doubly labeled water, respectively, and physical activity energy expenditure was determined as TEE - 0.1(TEE) - REE. Fat mass (FM) and fat-free mass (FFM) were evaluated by dual-energy x-ray absorptiometry and changed body energy stores was determined by 1.0(ΔFFM/Δtime) + 9.5(ΔFM/Δtime). EI was derived as TEE + EB. REE was predicted from baseline FFM, FM, sex, and sports. %MA was calculated as 100(measured REE/predicted REE-1) and MA (kcal) as %MA/100 multiplied by baseline measured REE. Average EI minus average physical activity energy expenditure was computed as a proxy of average energy availability, assuming that a constant nonexercise EE occurred over the season. Body mass increased by 0.8 ± 2.5 kg (P energy availability (r = 0.356 and r = 0.0644, respectively). TEE increased over the season without relevant mean changes in weight, suggesting that EI compensation likely occurred. The thrifty or spendthrift phenotypes observed among sports and the demanding workloads these athletes are exposed to highlight the need for sport-specific energy requirements.

  13. The energy challenge of a post-fossil world: Seasonal energy storage

    International Nuclear Information System (INIS)

    Forsberg, C.

    2009-01-01

    Fossil fuels are an energy source and an energy storage system. The demand for electricity and heat varies daily, weekly, and seasonally with seasonal variations often varying by a factor of two or more. The variable demand is met by fossil fuels because 1) fossil fuels are inexpensive to store in coal piles, oil tanks, and underground natural gas storage facilities and 2) the capital cost of the equipment to burn fossil fuels and convert the energy to heat or electricity is small relative to the cost of the fossil fuels. Concerns about climate change may limit the conventional use of fossil fuels. The alternative low-carbon energy production systems (nuclear, fossil fuels with carbon dioxide sequestration, wind, and solar) are capital-intensive energy sources with low operating costs. To obtain favorable economics these technologies must operate at full capacity; but, their output does not match energy demand. We have energy alternatives to fossil fuels but no replacements for the energy storage capabilities or fossil fuels. Proposed strategies and technologies to address the grand storage challenge (including seasonal storage of electricity) are described. The options suggest a nuclear-renewable future to address seasonal energy storage needs in a low-carbon world.

  14. Analyzing post-wildfire erosional processes and topographic change using hydrologic monitoring and Structure-from-Motion photogrammetry at the storm event scale

    Science.gov (United States)

    Leeper, R. J.; Barth, N. C.; Gray, A. B.

    2017-12-01

    Hydro-geomorphic response in recently burned watersheds is highly dependent on the timing and magnitude of subsequent rainstorms. Recent advancements in surveying and monitoring techniques using Unmanned Aerial Vehicles (UAV) and Structure-from-Motion (SfM) photogrammetry can support the rapid estimation of near cm-scale topographic response of headwater catchments (ha to km2). However, surface change due to shallow erosional processes such as sheetwash and rilling remain challenging to measure at this spatial extent and the storm event scale. To address this issue, we combined repeat UAV-SfM surveys with hydrologic monitoring techniques and field investigations to characterize post-wildfire erosional processes and topographic change on a storm-by-storm basis. The Las Lomas watershed ( 15 ha) burned in the 2016 San Gabriel Complex Fire along the front range of the San Gabriel Mountains, southern California. Surveys were conducted with a consumer grade UAV; twenty-six SfM control markers; two rain gages, and two pressure transducers were installed in the watershed. The initial SfM-derived point cloud generated from 422 photos contains 258 million points; the DEM has a resolution of 2.42 cm/pixel and a point density of 17.1 pts/cm2. Rills began forming on hillslopes and minor erosion occurred within the channel network during the first low intensity storms of the rainy season. Later more intense storms resulted in substantial geomorphic change. Hydrologic data indicate that during one of the intense storms total cumulative rainfall was 58.20 mm and peak 5-min intensity was 38.4 mm/hr. Poststorm field surveys revealed evidence of debris flows, flash flooding, erosion, and fluvial aggradation in the channel network, and rill growth and gully formation on hillslopes. Analyses of the SfM models indicate erosion dominated topographic change in steep channels and on hillslopes; aggradation dominated change in low gradient channels. A contrast of 5 cm exists between field

  15. Functionally specialised birds respond flexibly to seasonal changes in fruit availability.

    Science.gov (United States)

    Bender, Irene M A; Kissling, W Daniel; Böhning-Gaese, Katrin; Hensen, Isabell; Kühn, Ingolf; Wiegand, Thorsten; Dehling, D Matthias; Schleuning, Matthias

    2017-07-01

    Interactions between resource and consumer species result in complex ecological networks. The overall structure of these networks is often stable in space and time, but little is known about the temporal stability of the functional roles of consumer species in these networks. We used a trait-based approach to investigate whether consumers (frugivorous birds) show similar degrees of functional specialisation on resources (plants) in ecological networks across seasons. We additionally tested whether closely related bird species have similar degrees of functional specialisation and whether birds that are functionally specialised on specific resource types within a season are flexible in switching to other resource types in other seasons. We analysed four seasonal replicates of two species-rich plant-frugivore networks from the tropical Andes. To quantify fruit preferences of frugivorous birds, we projected their interactions with plants into a multidimensional plant trait space. To measure functional specialisation of birds, we calculated a species' functional niche breadth (the extent of seasonal plant trait space utilised by a particular bird) and functional originality (the extent to which a bird species' fruit preference functionally differs from those of other species in a seasonal network). We additionally calculated functional flexibility, i.e. the ability of bird species to change their fruit preference across seasons in response to variation in plant resources. Functional specialisation of bird species varied more among species than across seasons, and phylogenetically similar bird species showed similar degrees of functional niche breadth (phylogenetic signal λ = 0·81) and functional originality (λ = 0·89). Additionally, we found that birds with high functional flexibility across seasons had narrow functional niche breadth and high functional originality per season, suggesting that birds that are seasonally specialised on particular resources are

  16. Transport of sulfonamide antibiotics in crop fields during monsoon season.

    Science.gov (United States)

    Park, Jong Yol; Ruidisch, Marianne; Huwe, Bernd

    2016-11-01

    Previous studies have documented the occurrence of veterinary sulfonamide antibiotics in groundwater and rivers located far from pollution sources, although their transport and fate is relatively unknown. In mountainous agricultural fields, the transport behaviour can be influenced by climate, slope and physico-chemical properties of the sulfonamides. The objective of this research is to describe the transport behaviour of three sulfonamide antibiotics (sulfamethoxazole, sulfadimethoxine and sulfamethazine) in sloped agricultural fields located in the Haean catchment, South Korea. During dry and monsoon seasons, a solute transport experiment was conducted in two typical sandy loam agricultural fields after application of antibiotics and potassium bromide as conservative tracers. Field measurement and modelling revealed that frequency and amount of runoff generation indicate a relation between slope and rain intensity during monsoon season. Since the steepness of slope influenced partitioning of precipitation between runoff and subsurface flow, higher loss of sulfonamide antibiotics and bromide by runoff was observed at the steeper sloped field. Bromide on topsoil rapidly infiltrated at high infiltration rates. On the contrary, the sulfonamides were relatively retarded in the upper soil layer due to adsorption onto soil particles. Presence of furrows and ridges affected the distribution of sulfonamide antibiotics in the subsurface due to gradient from wetter furrows to drier ridges induced by topography. Modelling results with HydroGeoSphere matched with background studies that describe physico-chemical properties of the sulfonamides interaction between soil and the antibiotic group, solute transport through vadose zone and runoff generation by storm events.

  17. Post-Newtonian celestial dynamics in cosmology: Field equations

    Science.gov (United States)

    Kopeikin, Sergei M.; Petrov, Alexander N.

    2013-02-01

    Post-Newtonian celestial dynamics is a relativistic theory of motion of massive bodies and test particles under the influence of relatively weak gravitational forces. The standard approach for development of this theory relies upon the key concept of the isolated astronomical system supplemented by the assumption that the background spacetime is flat. The standard post-Newtonian theory of motion was instrumental in the explanation of the existing experimental data on binary pulsars, satellite, and lunar laser ranging, and in building precise ephemerides of planets in the Solar System. Recent studies of the formation of large-scale structures in our Universe indicate that the standard post-Newtonian mechanics fails to describe more subtle dynamical effects in motion of the bodies comprising the astronomical systems of larger size—galaxies and clusters of galaxies—where the Riemann curvature of the expanding Friedmann-Lemaître-Robertson-Walker universe interacts with the local gravitational field of the astronomical system and, as such, cannot be ignored. The present paper outlines theoretical principles of the post-Newtonian mechanics in the expanding Universe. It is based upon the gauge-invariant theory of the Lagrangian perturbations of cosmological manifold caused by an isolated astronomical N-body system (the Solar System, a binary star, a galaxy, and a cluster of galaxies). We postulate that the geometric properties of the background manifold are described by a homogeneous and isotropic Friedmann-Lemaître-Robertson-Walker metric governed by two primary components—the dark matter and the dark energy. The dark matter is treated as an ideal fluid with the Lagrangian taken in the form of pressure along with the scalar Clebsch potential as a dynamic variable. The dark energy is associated with a single scalar field with a potential which is hold unspecified as long as the theory permits. Both the Lagrangians of the dark matter and the scalar field are

  18. Use of post-thaw semen quality parameters to predict fertility of water buffalo (Bubalus bubalis) bull during peak breeding season.

    Science.gov (United States)

    Ahmed, H; Andrabi, S M H; Anwar, M; Jahan, S

    2017-05-01

    This study was designed to predict the fertility of water buffalo bull using post-thaw semen quality parameters during peak breeding season. Thirty ejaculates were collected from five bulls with artificial vagina and cryopreserved. At post-thaw, semen was analysed for motility parameters, velocity distribution, kinematics, DNA integrity/fragmentation, viability, mitochondrial transmembrane potential, morphology, plasma membrane and acrosome integrity. Data of 514 inseminations were collected for estimation of in vivo fertility. Pearson's correlation coefficients showed that progressive motility (PM), rapid velocity, average path velocity, straight line velocity, straightness, supravital plasma membrane integrity, viable spermatozoon with intact acrosome or with high mitochondrial activity were correlated with in vivo fertility (r = .81, p fertility was PM. However, combinations of semen quality parameters to predict fertility were better as compared to single parameter. In conclusion, fertility of buffalo bull can be predicted through some of the post-thaw in vitro semen quality tests during peak breeding season. © 2016 Blackwell Verlag GmbH.

  19. Seasonal and Interannual Trends in Largest Cholera Endemic Megacity: Water Sustainability - Climate - Health Challenges in Dhaka, Bangladesh

    Science.gov (United States)

    Akanda, Ali S.; Jutla, Antarpreet; Faruque, Abu S. G.; Huq, Anwar; Colwell, Rita R.

    2014-05-01

    The last three decades of surveillance data shows a drastic increase of cholera prevalence in the largest cholera-endemic city in the world - Dhaka, Bangladesh. Emerging megacities in the region, especially those located in coastal areas also remain vulnerable to large scale drivers of cholera outbreaks. However, there has not been any systematic study on linking long-term disease trends with related changes in natural or societal variables. Here, we analyze the 30-year dynamics of urban cholera prevalence in Dhaka with changes in climatic or anthropogenic forcings: regional hydrology, flooding, water usage, changes in distribution systems, population growth and density in urban settlements, as well as shifting climate patterns and frequency of natural disasters. An interesting change is observed in the seasonal trends of cholera prevalence; while an endemic upward trend is seen in the dry season, the post-monsoon trend is epidemic in nature. In addition, the trend in the pre-monsoon dry season is significantly stronger than the post-monsoon wet season; and thus spring is becoming the dominant cholera season of the year. Evidence points to growing urbanization and rising population in unplanned settlements along the city peripheries. The rapid pressure of growth has led to an unsustainable and potentially disastrous situation with negligible-to-poor water and sanitation systems compounded by changing climatic patterns and increasing number of extreme weather events. Growing water scarcity in the dry season and lack of sustainable water and sanitation infrastructure for urban settlements have increased endemicity of cholera outbreaks in spring, while record flood events and prolonged post-monsoon inundation have contributed to increased epidemic outbreaks in fall. We analyze our findings with the World Health Organization recommended guidelines and investigate large scale water sustainability challenges in the context of climatic and anthropogenic changes in the

  20. Fragmenting pastoral mobility: Changing grazing patterns in Post-Soviet Kazakhstan

    Science.gov (United States)

    Carol Kerven; Ilya Ilych Alimaev; Roy Behnke; Grant Davidson; Nurlan Malmakov; Aidos Smailov; Iain Wright

    2006-01-01

    Kazak nomads were seasonally mobile in the pre-Soviet period, in response to climate variability and landscape heterogeneity. The scale of these movements was interrupted during the Soviet period, but some degree of mobility remained. Mobility virtually ceased in the post-Soviet 1990s, but is reemerging as flock numbers rebound from the mid 1990s population crash.

  1. Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic Cartilage

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-14-1-0591 TITLE: Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic Cartilage PRINCIPAL...response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing...2016 – 29 Sep 2017 4. TITLE AND SUBTITLE Cartilage 5a. CONTRACT NUMBER Electric Field Stimulation Enhances Healing of Post-Traumatic Osteoarthritic

  2. Cognitive Change across Cognitive-Behavioral and Light Therapy Treatments for Seasonal Affective Disorder: What Accounts for Clinical Status the Next Winter?

    Science.gov (United States)

    Evans, Maggie; Rohan, Kelly J; Sitnikov, Lilya; Mahon, Jennifer N; Nillni, Yael I; Lindsey, Kathryn Tierney; Vacek, Pamela M

    2013-12-01

    Efficacious treatments for seasonal affective disorder include light therapy and a seasonal affective disorder-tailored form of cognitive-behavioral therapy. Using data from a parent clinical trial, these secondary analyses examined the relationship between cognitive change over treatment with cognitive-behavioral therapy, light therapy, or combination treatment and mood outcomes the next winter. Sixty-nine participants were randomly assigned to 6-weeks of cognitive-behavioral therapy, light therapy, or combination treatment. Cognitive constructs (i.e., dysfunctional attitudes, negative automatic thoughts, and rumination) were assessed at pre- and post-treatment. Dysfunctional attitudes, negative automatic thoughts, and rumination improved over acute treatment, regardless of modality; however, in participants randomized to solo cognitive-behavioral therapy, a greater degree of improvement in dysfunctional attitudes and automatic thoughts was uniquely associated with less severe depressive symptoms the next winter. Change in maladaptive thoughts during acute treatment appears mechanistic of solo cognitive-behavioral therapy's enduring effects the next winter, but is simply a consequence of diminished depression in light therapy and combination treatment.

  3. The Effect of Agricultural Growing Season Change on Market Prices in Africa

    Science.gov (United States)

    deBeurs, K.M.; Brown, M. E.

    2013-01-01

    Local agricultural production is a key element of food security in many agricultural countries in Africa. Climate change and variability is likely to adversely affect these countries, particularly as they affect the ability of smallholder farmers to raise enough food to feed themselves. Seasonality influences farmers' decisions about when to sow and harvest, and ultimately the success or failure of their crops. At a 2009 conference in the United Kingdom hosted by the Institute of Development Studies, Jennings and Magrath (2009) described farmer reports from East Asia, South Asia, Southern Africa, East Africa and Latin America. Farmers indicate significant changes in the timing of rainy seasons and the pattern of rains within seasons, including: More erratic rainfall, coming at unexpected times in and out of season; Extreme storms and unusually intense rainfall are punctuated by longer dry spells within the rainy season; Increasing uncertainty as to the start of rainy seasons in many areas; Short or transitional second rainy seasons are becoming stronger than normal or are disappearing altogether. These farmer perceptions of change are striking in that they are geographically widespread and are remarkably consistent across diverse regions (Jennings and Magrath, 2009). The impact of these changes on farmers with small plots and few resources is large. Farming is becoming riskier because of heat stress, lack of water, pests and diseases that interact with ongoing pressures on natural resources. Lack of predictability in the start and length of the growing season affects the ability of farmers to invest in appropriate fertilizer levels or improved, high yielding varieties. These changes occur at the same time as the demand for food is rising and is projected to continue to rise for the next fifty years (IAASTD, 2008). Long-term data records derived from satellite remote sensing can be used to verify these reports, providing necessary analysis and documentation required

  4. MODIS 250m burned area mapping based on an algorithm using change point detection and Markov random fields.

    Science.gov (United States)

    Mota, Bernardo; Pereira, Jose; Campagnolo, Manuel; Killick, Rebeca

    2013-04-01

    Area burned in tropical savannas of Brazil was mapped using MODIS-AQUA daily 250m resolution imagery by adapting one of the European Space Agency fire_CCI project burned area algorithms, based on change point detection and Markov random fields. The study area covers 1,44 Mkm2 and was performed with data from 2005. The daily 1000 m image quality layer was used for cloud and cloud shadow screening. The algorithm addresses each pixel as a time series and detects changes in the statistical properties of NIR reflectance values, to identify potential burning dates. The first step of the algorithm is robust filtering, to exclude outlier observations, followed by application of the Pruned Exact Linear Time (PELT) change point detection technique. Near-infrared (NIR) spectral reflectance changes between time segments, and post change NIR reflectance values are combined into a fire likelihood score. Change points corresponding to an increase in reflectance are dismissed as potential burn events, as are those occurring outside of a pre-defined fire season. In the last step of the algorithm, monthly burned area probability maps and detection date maps are converted to dichotomous (burned-unburned maps) using Markov random fields, which take into account both spatial and temporal relations in the potential burned area maps. A preliminary assessment of our results is performed by comparison with data from the MODIS 1km active fires and the 500m burned area products, taking into account differences in spatial resolution between the two sensors.

  5. Direct observations of ice seasonality reveal changes in climate over the past 320–570 years

    Science.gov (United States)

    Sharma, Sapna; Magnuson, John J.; Batt, Ryan D.; Winslow, Luke; Korhonen, Johanna; Yasuyuki Aono,

    2016-01-01

    Lake and river ice seasonality (dates of ice freeze and breakup) responds sensitively to climatic change and variability. We analyzed climate-related changes using direct human observations of ice freeze dates (1443–2014) for Lake Suwa, Japan, and of ice breakup dates (1693–2013) for Torne River, Finland. We found a rich array of changes in ice seasonality of two inland waters from geographically distant regions: namely a shift towards later ice formation for Suwa and earlier spring melt for Torne, increasing frequencies of years with warm extremes, changing inter-annual variability, waning of dominant inter-decadal quasi-periodic dynamics, and stronger correlations of ice seasonality with atmospheric CO2 concentration and air temperature after the start of the Industrial Revolution. Although local factors, including human population growth, land use change, and water management influence Suwa and Torne, the general patterns of ice seasonality are similar for both systems, suggesting that global processes including climate change and variability are driving the long-term changes in ice seasonality.

  6. Simulated effects of a seasonal precipitation change on the vegetation in tropical Africa

    Directory of Open Access Journals (Sweden)

    E. S. Gritti

    2010-03-01

    Full Text Available Pollen data collected in Africa at high (Kuruyange, valley swamp, Burundi and low altitude (Victoria, lake, Uganda; Ngamakala, pond, Congo showed that after 6 ky before present (BP, pollen of deciduous trees increase their relative percentage, suggesting thus the reduction of the annual amount of precipitation and/or an increase of in the length of the dry season. Until now, pollen-climate transfer functions only investigated mean annual precipitation, due to the absence of modern pollen-assemblage analogs under diversified precipitation regimes. Hence these functions omit the potential effect of a change in precipitation seasonality modifying thus the length of the dry season. In the present study, we use an equilibrium biosphere model (i.e. BIOME3.5 to estimate the sensitivity of equatorial African vegetation, at specific sites, to such changes. Climatic scenarios, differing only in the monthly distribution of the current annual amount of precipitation, are examined at the above three locations in equatorial Africa. Soil characteristics, monthly temperatures and cloudiness are kept constant at their present-day values. Good agreement is shown between model simulations and current biomes assemblages, as inferred from pollen data. To date, the increase of the deciduous forest component in the palaeodata around 6 ky BP has been interpreted as the beginning of a drier climate period. However, our results demonstrate that a change in the seasonal distribution of precipitation could also induce the observed changes in vegetation types. This study confirms the importance of taking into account seasonal changes in the hydrological balance. Palaeoecologists can greatly benefit from the use of dynamic process based vegetation models to acccount for modification of the length of the dry season when they wish to reconstruct vegetation composition or to infer quantitative climate parameters, such as temperature and precipitation, from pollen or vegetation

  7. Behavioural responses to thermal conditions affect seasonal mass change in a heat-sensitive northern ungulate.

    Directory of Open Access Journals (Sweden)

    Floris M van Beest

    Full Text Available BACKGROUND: Empirical tests that link temperature-mediated changes in behaviour (activity and resource selection to individual fitness or condition are currently lacking for endotherms yet may be critical to understanding the effect of climate change on population dynamics. Moose (Alces alces are thought to suffer from heat stress in all seasons so provide a good biological model to test whether exposure to non-optimal ambient temperatures influence seasonal changes in body mass. Seasonal mass change is an important fitness correlate of large herbivores and affects reproductive success of female moose. METHODOLOGY/PRINCIPAL FINDINGS: Using GPS-collared adult female moose from two populations in southern Norway we quantified individual differences in seasonal activity budget and resource selection patterns as a function of seasonal temperatures thought to induce heat stress in moose. Individual body mass was recorded in early and late winter, and autumn to calculate seasonal mass changes (n = 52 over winter, n = 47 over summer. We found large individual differences in temperature-dependent resource selection patterns as well as within and between season variability in thermoregulatory strategies. As expected, individuals using an optimal strategy, selecting young successional forest (foraging habitat at low ambient temperatures and mature coniferous forest (thermal shelter during thermally stressful conditions, lost less mass in winter and gained more mass in summer. CONCLUSIONS/SIGNIFICANCE: This study provides evidence that behavioural responses to temperature have important consequences for seasonal mass change in moose living in the south of their distribution in Norway, and may be a contributing factor to recently observed declines in moose demographic performance. Although the mechanisms that underlie the observed temperature mediated habitat-fitness relationship remain to be tested, physiological state and individual variation in

  8. Behavioural responses to thermal conditions affect seasonal mass change in a heat-sensitive northern ungulate.

    Science.gov (United States)

    van Beest, Floris M; Milner, Jos M

    2013-01-01

    Empirical tests that link temperature-mediated changes in behaviour (activity and resource selection) to individual fitness or condition are currently lacking for endotherms yet may be critical to understanding the effect of climate change on population dynamics. Moose (Alces alces) are thought to suffer from heat stress in all seasons so provide a good biological model to test whether exposure to non-optimal ambient temperatures influence seasonal changes in body mass. Seasonal mass change is an important fitness correlate of large herbivores and affects reproductive success of female moose. Using GPS-collared adult female moose from two populations in southern Norway we quantified individual differences in seasonal activity budget and resource selection patterns as a function of seasonal temperatures thought to induce heat stress in moose. Individual body mass was recorded in early and late winter, and autumn to calculate seasonal mass changes (n = 52 over winter, n = 47 over summer). We found large individual differences in temperature-dependent resource selection patterns as well as within and between season variability in thermoregulatory strategies. As expected, individuals using an optimal strategy, selecting young successional forest (foraging habitat) at low ambient temperatures and mature coniferous forest (thermal shelter) during thermally stressful conditions, lost less mass in winter and gained more mass in summer. This study provides evidence that behavioural responses to temperature have important consequences for seasonal mass change in moose living in the south of their distribution in Norway, and may be a contributing factor to recently observed declines in moose demographic performance. Although the mechanisms that underlie the observed temperature mediated habitat-fitness relationship remain to be tested, physiological state and individual variation in thermal tolerance are likely contributory factors. Climate-related effects on animal

  9. Reduced brain glutamine in female varsity rugby athletes after concussion and in non-concussed athletes after a season of play.

    Science.gov (United States)

    Schranz, Amy L; Manning, Kathryn Y; Dekaban, Gregory A; Fischer, Lisa; Jevremovic, Tatiana; Blackney, Kevin; Barreira, Christy; Doherty, Timothy J; Fraser, Douglas D; Brown, Arthur; Holmes, Jeff; Menon, Ravi S; Bartha, Robert

    2018-04-01

    The purpose of this study was to use non-invasive proton magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) to monitor changes in prefrontal white matter metabolite levels and tissue microstructure in female rugby players with and without concussion (ages 18-23, n = 64). Evaluations including clinical tests and 3 T MRI were performed at the beginning of a season (in-season) and followed up at the end of the season (off-season). Concussed athletes were additionally evaluated 24-72 hr (n = 14), three months (n = 11), and six months (n = 8) post-concussion. Reduced glutamine at 24-72 hr and three months post-concussion, and reduced glutamine/creatine at three months post-concussion were observed. In non-concussed athletes (n = 46) both glutamine and glutamine/creatine were lower in the off-season compared to in-season. Within the MRS voxel, an increase in fractional anisotropy (FA) and decrease in radial diffusivity (RD) were also observed in the non-concussed athletes, and correlated with changes in glutamine and glutamine/creatine. Decreases in glutamine and glutamine/creatine suggest reduced oxidative metabolism. Changes in FA and RD may indicate neuroinflammation or re-myelination. The observed changes did not correlate with clinical test scores suggesting these imaging metrics may be more sensitive to brain injury and could aid in assessing recovery of brain injury from concussion. © 2017 Wiley Periodicals, Inc.

  10. Seasonal variations in health-related human physical activity.

    Science.gov (United States)

    Reilly, Thomas; Peiser, Benny

    2006-01-01

    There are profound fluctuations in climate that occur within the annual cycle of seasonal changes. The severity of these changes depends on latitude of location and prevailing topography. Living creatures have evolved means of coping with seasonal extremes. Endogenous circannual cycles, at least in humans, appear to have been masked by mechanisms employed to cope with environmental changes. Physical activity levels tend to be lower in winter than in summer, mediating effects on health-related fitness. In athletes, seasonal changes are dictated by requirements of the annual programme of competitive engagements rather than an inherent circannual rhythm. Injury rates are influenced by seasonal environmental factors, notably in field sports. Season of birth has been related to susceptibility to selected morbidities, including mental ill-health. In age-restricted sports, there is a date-of-birth bias favouring those individuals born early in the competitive year. Trainers and selectors should acknowledge this trend if they are to avoid omitting gifted individuals, born later in the year, from talent development programmes.

  11. The responses of microbial temperature relationships to seasonal change and winter warming in a temperate grassland.

    Science.gov (United States)

    Birgander, Johanna; Olsson, Pål Axel; Rousk, Johannes

    2018-01-18

    Microorganisms dominate the decomposition of organic matter and their activities are strongly influenced by temperature. As the carbon (C) flux from soil to the atmosphere due to microbial activity is substantial, understanding temperature relationships of microbial processes is critical. It has been shown that microbial temperature relationships in soil correlate with the climate, and microorganisms in field experiments become more warm-tolerant in response to chronic warming. It is also known that microbial temperature relationships reflect the seasons in aquatic ecosystems, but to date this has not been investigated in soil. Although climate change predictions suggest that temperatures will be mostly affected during winter in temperate ecosystems, no assessments exist of the responses of microbial temperature relationships to winter warming. We investigated the responses of the temperature relationships of bacterial growth, fungal growth, and respiration in a temperate grassland to seasonal change, and to 2 years' winter warming. The warming treatments increased winter soil temperatures by 5-6°C, corresponding to 3°C warming of the mean annual temperature. Microbial temperature relationships and temperature sensitivities (Q 10 ) could be accurately established, but did not respond to winter warming or to seasonal temperature change, despite significant shifts in the microbial community structure. The lack of response to winter warming that we demonstrate, and the strong response to chronic warming treatments previously shown, together suggest that it is the peak annual soil temperature that influences the microbial temperature relationships, and that temperatures during colder seasons will have little impact. Thus, mean annual temperatures are poor predictors for microbial temperature relationships. Instead, the intensity of summer heat-spells in temperate systems is likely to shape the microbial temperature relationships that govern the soil-atmosphere C

  12. Changes in muscle activation following balance and technique training and a season of Australian football.

    Science.gov (United States)

    Donnelly, C J; Elliott, B C; Doyle, T L A; Finch, C F; Dempsey, A R; Lloyd, D G

    2015-05-01

    Determine if balance and technique training implemented adjunct to 1001 male Australian football players' training influenced the activation/strength of the muscles crossing the knee during pre-planned and unplanned sidestepping. Randomized Control Trial. Each Australian football player participated in either 28 weeks of balance and technique training or 'sham' training. Twenty-eight Australian football players (balance and technique training, n=12; 'sham' training, n=16) completed biomechanical testing pre-to-post training. Peak knee moments and directed co-contraction ratios in three degrees of freedom, as well as total muscle activation were calculated during pre-planned and unplanned sidestepping. No significant differences in muscle activation/strength were observed between the 'sham' training and balance and technique training groups. Following a season of Australian football, knee extensor (p=0.023) and semimembranosus (p=0.006) muscle activation increased during both pre-planned sidestepping and unplanned sidestepping. Following a season of Australian football, total muscle activation was 30% lower and peak valgus knee moments 80% greater (p=0.022) during unplanned sidestepping when compared with pre-planned sidestepping. When implemented in a community level training environment, balance and technique training was not effective in changing the activation of the muscles crossing the knee during sidestepping. Following a season of Australian football, players are better able to support both frontal and sagittal plane knee moments. When compared to pre-planned sidestepping, Australian football players may be at increased risk of anterior cruciate ligament injury during unplanned sidestepping in the latter half of an Australian football season. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  13. Changing Seasonality and the Role of the Shoulder Season - Evidence from Denamrk

    DEFF Research Database (Denmark)

    Sørensen, Nils Karl

    2009-01-01

    the issue of the shoulder season in a time series framework. Departing from a discussion of the nature of types of seasonal variation, a test is set up in order to examine the impact of the shoulder season. The test examines the impact on the mean share of hotel nights in the shoulder season months in two...

  14. Analyzing Change of Seasonal Crop Water Consumption in Kayseri Province

    OpenAIRE

    YÜREKLİ, Kadri; ÜNLÜKARA, Ali; SAFİ, Sevda

    2010-01-01

    Main Purpose of this study is that the change of seasonal reference evapotranspiration (ETo) based on FAO56 Penman-Monteith relationship for k-reference periods ( k1; January-March, k2; January-June, k3; January-September, k4; January-December) is determined in Kayseri province located in Middle Anatolian Region having low annual mean rainfall. In this reason, the parametric (Unit Root) and non-parametric (Kruskal-Wallis and Levene) tests were applied to the seasonal ETo values from meteorolo...

  15. Seasonal changes, sleep length and circadian preference among twins with bipolar disorder

    Directory of Open Access Journals (Sweden)

    Koskenvuo Markku

    2003-06-01

    Full Text Available Abstract Background We aimed at studying the seasonal changes in mood and behaviour, the distribution of hospital admissions by season, and the persistence of the circadian type in twins with bipolar disorder and their healthy co-twins. Methods All Finnish like-sex twins born from 1940 to 1969 were screened for a diagnosis of bipolar type I disorder. The diagnosis was assessed with a structured research interview, and the study subjects (n = 67 filled in the Seasonal Pattern Assessment Questionnaire (SPAQ and the Morningness-Eveningness Questionnaire (MEQ. For studying the persistence of the habitual sleep length and circadian type, we used data derived from the Finnish Twin Cohort Questionnaire (FTCQ. Bipolar twins were compared with their healthy co-twins. Results Bipolar twins had greater seasonal changes in sleep length (p = 0.01 and mood (p = 0.01, and higher global seasonality scores (p = 0.03 as compared with their co-twins with no mental disorder. Sunny days (p = 0.03 had a greater positive effect on wellbeing in the bipolar than healthy co-twins. Conclusions Our results support the view that bipolar disorder is sensitive to the environmental influence in general and to the seasonal effect in specific. Exposure to natural light appears to have a substantial effect on wellbeing in twins with bipolar disorder.

  16. The F-region trough: seasonal morphology and relation to interplanetary magnetic field

    Directory of Open Access Journals (Sweden)

    M. Voiculescu

    2006-03-01

    Full Text Available We present here the results of a statistical study of the ionospheric trough observed in 2003 by means of satellite tomography. We focus on the seasonal morphology of the trough occurrence and investigate the trough latitude, width and the horizontal gradients at the edges, at different magnetic local times, as well as their relations to geomagnetic activity and the interplanetary magnetic field. A seasonal effect is noticed in the diurnal variation of the trough latitude, indicating that summer clearly differs from the other seasons. In winter the troughs seem to follow the solar terminator. The width of the trough has a diurnal variation and it depends on the season, as well. The broadest troughs are observed in winter and the narrowest ones in summer. A discontinuity in the diurnal variation of the trough latitude is observed before noon. It is suggested that this is an indication of a difference between the generation mechanisms of morningside and eveningside troughs. The density gradients at the edges have a complex dependence on the latitude of the trough and on geomagnetic activity. The photoionization and the auroral precipitation are competing in the formation of the trough walls at different magnetic local times. An important finding is that the interplanetary magnetic field plays a role in the occurrence of the trough at different levels of geomagnetic activity. This is probably associated with the topology of the polar cap convection pattern, which depends on the directions of the IMF components By and Bz.

  17. The F-region trough: seasonal morphology and relation to interplanetary magnetic field

    Directory of Open Access Journals (Sweden)

    M. Voiculescu

    2006-03-01

    Full Text Available We present here the results of a statistical study of the ionospheric trough observed in 2003 by means of satellite tomography. We focus on the seasonal morphology of the trough occurrence and investigate the trough latitude, width and the horizontal gradients at the edges, at different magnetic local times, as well as their relations to geomagnetic activity and the interplanetary magnetic field. A seasonal effect is noticed in the diurnal variation of the trough latitude, indicating that summer clearly differs from the other seasons. In winter the troughs seem to follow the solar terminator. The width of the trough has a diurnal variation and it depends on the season, as well. The broadest troughs are observed in winter and the narrowest ones in summer. A discontinuity in the diurnal variation of the trough latitude is observed before noon. It is suggested that this is an indication of a difference between the generation mechanisms of morningside and eveningside troughs. The density gradients at the edges have a complex dependence on the latitude of the trough and on geomagnetic activity. The photoionization and the auroral precipitation are competing in the formation of the trough walls at different magnetic local times. An important finding is that the interplanetary magnetic field plays a role in the occurrence of the trough at different levels of geomagnetic activity. This is probably associated with the topology of the polar cap convection pattern, which depends on the directions of the IMF components By and Bz.

  18. Seasonal changes in physiological performance in wild Clarkia xantiana populations: Implications for the evolution of a compressed life cycle and self-fertilization.

    Science.gov (United States)

    Dudley, Leah S; Hove, Alisa A; Emms, Simon K; Verhoeven, Amy S; Mazer, Susan J

    2015-06-01

    One explanation for the evolution of selfing, the drought escape hypothesis, proposes that self-fertilization may evolve under conditions of intensifying seasonal drought as part of a suite of traits that enable plants to accelerate the completion of their life cycle, thereby escaping late-season drought. Here, we test two fundamental assumptions of this hypothesis in Clarkia xantiana: (1) that a seasonal decline in precipitation causes an increase in drought stress and (2) that this results in changes in physiological performance, reflecting these deteriorating conditions. We examined seasonal and interannual variation in abiotic environmental conditions (estimated by ambient temperature, relative humidity, predawn leaf water potentials, and carbon isotope ratios) and physiological traits (photosynthesis, conductance, transpiration, instantaneous water-use efficiency, ascorbate peroxidase and glutathione reductase activities, quantum yield of photosystem II, PSII potential efficiency) in field populations of C. xantiana in 2009 and 2010. In both years, plants experienced intensifying drought across the growing season. Gas exchange rates decreased over the growing season and were lower in 2009 (a relatively dry year) than in 2010, suggesting that the temporal changes from early to late spring were directly linked to the deteriorating environmental conditions. Seasonal declines in transpiration rate may have increased survival by protecting plants from desiccation. Concomitant declines in photosynthetic rate likely reduced the availability of resources for seed production late in the season. Thus, the physiological patterns observed are consistent with the conditions required for the drought escape hypothesis. © 2015 Botanical Society of America, Inc.

  19. Failure to detect seasonal changes in the song system nuclei of the black-capped chickadee (Poecile atricapillus).

    Science.gov (United States)

    Smulders, T V; Lisi, M D; Tricomi, E; Otter, K A; Chruszcz, B; Ratcliffe, L M; DeVoogd, T J

    2006-08-01

    Most temperate songbird species sing seasonally, and the brain areas involved in producing song (the song system) vary in size alongside the changes in behavior. Black-capped chickadees (Poecile atricapillus) also sing seasonally, and we find that there are changes in the stereotypy and the length of the fee-bee song from the nonbreeding to the breeding season. Yet despite these changes, we fail to find any evidence of seasonal changes in the song system. The song system of males is larger than that of females, as is typical in songbirds, but the ratio between the sexes is small compared to other species. We suggest three hypotheses to explain our failure to find seasonal variation in the chickadee song system.

  20. PHYSIOLOGICAL AND PHENOLOGICAL VEGETATIVE RESPONSES OF Campomanesia adamantium (Cambess O. Berg (Myrtaceae TO THE HYDRIC SEASONALITY OF RUPESTRIAN FIELDS

    Directory of Open Access Journals (Sweden)

    Vinícius Coelho Kuster

    Full Text Available ABSTRACT The rupestrian fields have two well-defined seasons throughout the year, with rainfall rates that reflect the rainy and dry seasons. This distinction in water availability affects the morphology, physiology and chemistry of plants, among other characteristics. Thus, it is aimed at evaluating the leaf water status, vegetative phenology and photosynthetic behavior of Campomanesia adamantium from a rupestrian field during the dry and rainy season. The study was conducted in Serra do Cipó, Minas Gerais, Brazil. From November 2011 to November 2012 it was examined vegetative phenophases and development of six individuals. Water potential, stomatal conductance, quantum yield and concentration of pigments were evaluated from four leaves of 3rd node per individual (n = 4-5 in the dry and rainy seasons. C. adamantium is an evergreen type and presents mature leaves and sprouting throughout the year. This species showed strategies that reduce water loss during the dry season in rupestrian field, such as decrease in stomatal conductance throughout the day, also associated with a reduction in leaf water potential. However, low water availability did not affect the photosynthetic performance, which enables the construction of new leaves and renovation of the crown even in dry periods. Finally, little reduction in the values of Fv/Fm throughout the day and increase the values of ΔF/Fm' in warmer times, both in the dry season, reiterates the ability of C. adamantium to adjust their physiology to seasonal water deficit of the rupestrian field.

  1. A structural equation model to integrate changes in functional strategies during old-field succession.

    Science.gov (United States)

    Vile, Denis; Shipley, Bill; Garnier, Eric

    2006-02-01

    From a functional perspective, changes in abundance, and ultimately species replacement, during succession are a consequence of integrated suites of traits conferring different relative ecological advantages as the environment changes over time. Here we use structural equations to model the interspecific relationships between these integrated functional traits using 34 herbaceous species from a Mediterranean old-field succession and thus quantify the notion of a plant strategy. We measured plant traits related to plant vegetative and reproductive size, leaf functioning, reproductive phenology, seed mass, and production on 15 individuals per species monitored during one growing season. The resulting structural equation model successfully accounts for the pattern of trait covariation during the first 45 years post-abandonment using just two forcing variables: time since site abandonment and seed mass; no association between time since field abandonment and seed mass was observed over these herbaceous stages of secondary succession. All other predicted traits values are determined by these two variables and the cause-effect linkage between them. Adding pre-reproductive vegetative mass as a third forcing variable noticeably increased the predictive power of the model. Increasing the time after abandonment favors species with increasing life span and pre-reproductive biomass and decreasing specific leaf area. Allometric coefficients relating vegetative and reproductive components of plant size were in accordance with allometry theory. The model confirmed the trade-off between seed mass and seed number. Maximum plant height and seed mass were major determinants of reproductive phenology. Our results show that beyond verbal conceptualization, plant ecological strategies can be quantified and modeled.

  2. Seasonal Mass Changes and Crustal Vertical Deformations Constrained by GPS and GRACE in Northeastern Tibet

    Directory of Open Access Journals (Sweden)

    Yuanjin Pan

    2016-08-01

    Full Text Available Surface vertical deformation includes the Earth’s elastic response to mass loading on or near the surface. Continuous Global Positioning System (CGPS stations record such deformations to estimate seasonal and secular mass changes. We used 41 CGPS stations to construct a time series of coordinate changes, which are decomposed by empirical orthogonal functions (EOFs, in northeastern Tibet. The first common mode shows clear seasonal changes, indicating seasonal surface mass re-distribution around northeastern Tibet. The GPS-derived result is then assessed in terms of the mass changes observed in northeastern Tibet. The GPS-derived common mode vertical change and the stacked Gravity Recovery and Climate Experiment (GRACE mass change are consistent, suggesting that the seasonal surface mass variation is caused by changes in the hydrological, atmospheric and non-tidal ocean loads. The annual peak-to-peak surface mass changes derived from GPS and GRACE results show seasonal oscillations in mass loads, and the corresponding amplitudes are between 3 and 35 mm/year. There is an apparent gradually increasing gravity between 0.1 and 0.9 μGal/year in northeast Tibet. Crustal vertical deformation is determined after eliminating the surface load effects from GRACE, without considering Glacial Isostatic Adjustment (GIA contribution. It reveals crustal uplift around northeastern Tibet from the corrected GPS vertical velocity. The unusual uplift of the Longmen Shan fault indicates tectonically sophisticated processes in northeastern Tibet.

  3. Modeling seasonal behavior changes and disease transmission with application to chronic wasting disease.

    Science.gov (United States)

    Oraby, Tamer; Vasilyeva, Olga; Krewski, Daniel; Lutscher, Frithjof

    2014-01-07

    Behavior and habitat of wildlife animals change seasonally according to environmental conditions. Mathematical models need to represent this seasonality to be able to make realistic predictions about the future of a population and the effectiveness of human interventions. Managing and modeling disease in wild animal populations requires particular care in that disease transmission dynamics is a critical consideration in the etiology of both human and animal diseases, with different transmission paradigms requiring different disease risk management strategies. Since transmission of infectious diseases among wildlife depends strongly on social behavior, mechanisms of disease transmission could also change seasonally. A specific consideration in this regard confronted by modellers is whether the contact rate between individuals is density-dependent or frequency-dependent. We argue that seasonal behavior changes could lead to a seasonal shift between density and frequency dependence. This hypothesis is explored in the case of chronic wasting disease (CWD), a fatal disease that affects deer, elk and moose in many areas of North America. Specifically, we introduce a strategic CWD risk model based on direct disease transmission that accounts for the seasonal change in the transmission dynamics and habitats occupied, guided by information derived from cervid ecology. The model is composed of summer and winter susceptible-infected (SI) equations, with frequency-dependent and density-dependent transmission dynamics, respectively. The model includes impulsive birth events with density-dependent birth rate. We determine the basic reproduction number as a weighted average of two seasonal reproduction numbers. We parameterize the model from data derived from the scientific literature on CWD and deer ecology, and conduct global and local sensitivity analyses of the basic reproduction number. We explore the effectiveness of different culling strategies for the management of CWD

  4. Post-Occupancy Evaluation of Facilities Change

    NARCIS (Netherlands)

    van der Voordt, Theo; de Been, I.; Maarleveld, M.; Finch, E

    2012-01-01

    This chapter discusses possible aims, tools and deliverables of Post-Occupancy Evaluations (POE) (otherwise known as building-in-use studies), with a focus on interventions in supporting facilities. POE has a long tradition and has been applied in different fields (e.g. offices, educational

  5. Baseline and post-stress seasonal changes in immunocompetence and redox state maintenance in the fishing bat Myotis vivesi

    Science.gov (United States)

    Ibáñez-Contreras, Alejandra; Miranda-Labra, Roxana U.; Flores-Martínez, José Juan

    2018-01-01

    Little is known of how the stress response varies when animals confront seasonal life-history processes. Antioxidant defenses and damage caused by oxidative stress and their link with immunocompetence are powerful biomarkers to assess animal´s physiological stress response. The aim of this study was A) to determine redox state and variation in basal (pre-acute stress) immune function during summer, autumn and winter (spring was not assessed due to restrictions in collecting permit) in the fish-eating Myotis (Myotis vivesi; Chiroptera), and B) to determine the effect of acute stress on immunocompetence and redox state during each season. Acute stress was stimulated by restricting animal movement for 6 and 12 h. The magnitude of the cellular immune response was higher during winter whilst that of the humoral response was at its highest during summer. Humoral response increased after 6 h of movement restriction stress and returned to baseline levels after 12 h. Basal redox state was maintained throughout the year, with no significant changes in protein damage, and antioxidant activity was modulated mainly in relation to variation to environment cues, increasing during high temperatures and decreasing during windy nights. Antioxidant activity increased after the 6 h of stressful stimuli especially during summer and autumn, and to a lesser extent in early winter, but redox state did not vary. However, protein damage increased after 12 h of stress during summer. Prolonged stress when the bat is engaged in activities of high energy demand overcame its capacity to maintain homeostasis resulting in oxidative damage. PMID:29293551

  6. Seasonality in the dung beetle community in a Brazilian tropical dry forest: Do small changes make a difference?

    Science.gov (United States)

    Medina, Anderson Matos; Lopes, Priscila Paixão

    2014-01-01

    Dung beetle (Coleoptera: Scarabaeoidea: Scarabaeinae) activity is influenced by rainfall seasonality. We hypothesized that rainfall might also play a major role in regulating the community structure of this group. In this study, we describe seasonal changes in the richness, composition, and structure of the Scarabaeinae community in a Brazilian tropical dry forest. A fragment of arboreal Caatinga was sampled using baited pitfall traps during the early dry season (EDS), late dry season (LDS), early wet season (EWS), and middle wet season (MWS). We compared the dung beetle community in each season in relationship to species richness, rank-dominance, curves, and composition. We collected 1352 Scarabaeinae individuals , belonging to 15 species. Dichotomius aff. laevicollis Felsche (Coleoptera: Scarabaeidae) was the dominant species, representing 73.89% of the individuals. There were no seasonal changes in the rank dominance curves; all had a single dominant species and a few species with low abundance, typical for arid areas. Estimated richness was highest in MWS, followed by EWS. Dry-season samples (EDS and LDS) had lower richness, with no significant difference between the dry seasons. Although species richness increased as the habitat became wetter, the difference between the wet and dry seasons was small, which differs completely from the findings of other studies in Neotropical dry forests, where almost all species cease activities in the dry season. Species composition changes were found in non-metric multidimensional scaling and sustained by analysis of similarity. All the seasons had pairwise differences in composition, with the exception of EDS and MWS, which indicates that the dung beetle community in this fragment requires more than three months of drought to trigger changes in species composition; this is probably due to small changes in the forest canopy. There was no difference in composition between EDS and MWS. As in other tropical dry forests, although

  7. species diversity of dry season avian fauna in kano, nigeria 418

    African Journals Online (AJOL)

    userpc

    encounter in the field changes as the dry season progresses. ... The general purpose of most avian field studies ... high diversity of exotic trees. There is ..... Field. Guide. ISBN. 9780691159201. Pyre A. R. (1995) Avifauna diversity and human.

  8. Mid-Season Leaf Glutamine Predicts End-Season Maize Grain Yield and Nitrogen Content in Response to Nitrogen Fertilization under Field Conditions

    Directory of Open Access Journals (Sweden)

    Travis Goron

    2017-06-01

    Full Text Available After uptake in cereal crops, nitrogen (N is rapidly assimilated into glutamine (Gln and other amino acids for transport to sinks. Therefore Gln has potential as an improved indicator of soil N availability compared to plant N demand. Gln has primarily been assayed to understand basic plant physiology, rather than to measure plant/soil-N under field conditions. It was hypothesized that leaf Gln at early-to-mid season could report the N application rate and predict end-season grain yield in field-grown maize. A three-year maize field experiment was conducted with N application rates ranging from 30 to 218 kg ha−1. Relative leaf Gln was assayed from leaf disk tissue using a whole-cell biosensor for Gln (GlnLux at the V3-V14 growth stages. SPAD (Soil Plant Analysis Development and NDVI (Normalized Difference Vegetation Index measurements were also performed. When sampled at V6 or later, GlnLux glutamine output consistently correlated with the N application rate, end-season yield, and grain N content. Yield correlation outperformed GreenSeekerTM NDVI, and was equivalent to SPAD chlorophyll, indicating the potential for yield prediction. Additionally, depleting soil N via overplanting increased GlnLux resolution to the earlier V5 stage. The results of the study are discussed in the context of luxury N consumption, leaf N remobilization, senescence, and grain fill. The potential and challenges of leaf Gln and GlnLux for the study of crop N physiology, and future N management are also discussed.

  9. Interannual and seasonal changes in the south seasonal polar cap of Mars: Observations from MY 28-31 using MARCI

    Science.gov (United States)

    Calvin, W. M.; Cantor, B. A.; James, P. B.

    2017-08-01

    The Mars Color Imager (MARCI) camera on the Mars Reconnaissance Orbiter provides daily synoptic coverage that allows monitoring of seasonal cap retreat and interannual changes that occur between Mars Years (MY) and over the southern summer. We present the first analysis of this data for the southern seasonal cap evolution observed in MY 28, 29, 30 and 31 (2/2007 to 07/2013). Observation over multiple Mars years allows us to compare changes between years as well as longer-term evolution of the high albedo deposits at the poles. Seasonal cap retreat is similar in all years and to retreats observed in other years by both optical and thermal instruments. The cryptic terrain has a fairly consistent boundary in each year, but numerous small-scale variations occur in each MY observed. Additionally, numerous small dark deposits are identified outside the classically identified cyptic region, including Inca City and other locations not previously noted. The large water ice outlier is observed to retain seasonal frost the longest (outside the polar dome) and is also highly variable in each MY. The development of the cryptic/anti-cryptic hemispheres is inferred to occur due to albedo variations that develop after dust venting starts and may be caused by recondensation of CO2 ice on the brightest and coldest regions controlled by topographic winds. Ground ice may play a role in which regions develop cryptic terrain, as there is no elevation control on either cryptic terrain or the late season brightest deposits.

  10. Seasonal biochemical changes in composition of body wall tissues of sea cucumber Apostichopus japonicus

    Science.gov (United States)

    Gao, Fei; Xu, Qiang; Yang, Hongsheng

    2011-03-01

    Seasonal Variation in proximate, amino acid and fatty acid composition of the body wall of sea cucumber Apostichopus japonicus was evaluated. The proximate composition, except for ash content, changed significantly among seasons ( P<0.05). Alanine, glycine, glutamic acid and asparagic acid were the most abundant amino acids. Total amino acid and essential amino acid Contents both varied clearly with seasons ( P<0.05). 16:0 and 16:ln7 were the primary saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) respectively for all months. EPA (20:5n-3), AA (20:4n-6) and DHA (22:6n-3) were the major polyunsaturated fatty acids (PUFA). The proportions of SFA and PUFA yielded significant seasonal variations ( P<0.001), but MUFA did not changed significantly. The results indicated that the biochemical compositions of the body wall in A. japonicus were significantly influenced by seasons and that the body wall tissue is an excellent source of protein, MUFA and n-3 PUFA for humans.

  11. Changing seasonality of Arctic hydrology disrupts key biotic linkages in Arctic aquatic ecosystems.

    Science.gov (United States)

    Deegan, L.; MacKenzie, C.; Peterson, B. J.; Fishscape Project

    2011-12-01

    Arctic grayling (Thymallus arcticus) is an important circumpolar species that provide a model system for understanding the impacts of changing seasonality on arctic ecosystem function. Grayling serve as food for other biota, including lake trout, birds and humans, and act as top-down controls in stream ecosystems. In Arctic tundra streams, grayling spend their summers in streams but are obligated to move back into deep overwintering lakes in the fall. Climatic change that affects the seasonality of river hydrology could have a significant impact on grayling populations: grayling may leave overwintering lakes sooner in the spring and return later in the fall due to a longer open water season, but the migration could be disrupted by drought due to increased variability in discharge. In turn, a shorter overwintering season may impact lake trout dynamics in the lakes, which may rely on the seasonal inputs of stream nutrients in the form of migrating grayling into these oligotrophic lakes. To assess how shifting seasonality of Arctic river hydrology may disrupt key trophic linkages within and between lake and stream components of watersheds on the North Slope of the Brooks Mountain Range, Alaska, we have undertaken new work on grayling and lake trout population and food web dynamics. We use Passive Integrated Transponder (PIT) tags coupled with stream-width antenna units to monitor grayling movement across Arctic tundra watersheds during the summer, and into overwintering habitat in the fall. Results indicate that day length may prime grayling migration readiness, but that flooding events are likely the cue grayling use to initiate migration in to overwintering lakes. Many fish used high discharge events in the stream as an opportunity to move into lakes. Stream and lake derived stable isotopes also indicate that lake trout rely on these seasonally transported inputs of stream nutrients for growth. Thus, changes in the seasonality of river hydrology may have broader

  12. Retrospective assessment of seasonal allergic symptoms

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Poulsen, L K; Malling, H-J

    2003-01-01

    in a double-blind study. Assessment of severity of symptoms from the nose, eyes and lungs were performed daily during the season 2000, and post-seasonally 6 months after the season in 1999 and 2000. A four-point verbal descriptor scale (VDS-4) was used at all occasions. A mean in-seasonal symptom rating...

  13. Changing cultural landscape in post-productivism of rice field in Nyuh Kuning Village Bali

    Science.gov (United States)

    Maulidi, C.; Wulandari, L. D.

    2017-06-01

    Natural landscape in developing countries is facing a challenge due to economic growth, a cultural shift, and population dynamics. Farm land where is close to urban areas tending to be converted into more economically valuable spaces. Watershed Pakerisan listed as World Heritage of UNESCO, rich of cultural value on its landscape, especially the Subak, a traditional irrigation system, has a close relationship to the philosophy of Hindu-Bali culture. Nyuh Kuning, a village (local terms is Banjar) located adjacent to the Pakerisan Watershed, and has a spatial pattern in synergic ally connected with tradition, culture, and their religion. Rice field not only for economical but also its place to worship the Goddess (Dewi Sri). Rice Field in Nyuh Kuning declined significantly along past 10 years. The changing landscape of Nyuh Kuning traced through serial of aerial photographs from 2005 until 2015. Along with the broad decline of rice field, villager’s attachment on their cultural space is also changing. An economic motive pronounces a winner in the bargaining between the motives of economic value and cultural value in the Nyuh Kuning. Villagers revealed arguments that necessities nowadays prosecute high consumption, both for household and for education. Therefore conversion of rice fields to become more economical is understandable among communities. Villagers rent the rice fields to foreigners (migrants), and then foreigners take rice-fields as personal assets, not for the villagers (ritual activities and the cultural traditions) any longer. In theoritical term, villager’s emotional bond to the cultural landscape in post—productivism of rice field, is weakened. Wawedangan Desa and its complex cultural values are not part of their identity anymore. However, place dependence become the reason why the shifting place attachment is happening. Functional economic bond is mentioned as place dependence dominats in villager’s attachment. Certainly it’s not a

  14. Change in Length of Growing Season by State, 1895-2015

    Data.gov (United States)

    U.S. Environmental Protection Agency — This map shows the total change in length of the growing season, time of first fall frost and time of last spring frost from 1895 to 2015 for each of the contiguous...

  15. Selectivity of silica species in ocean observed from seasonal and local changes

    Science.gov (United States)

    Tanaka, Miho; Takahashi, Kazuya; Nemoto, Masao; Horimoto, Naho

    2013-03-01

    Silicic acids, derived from SiO2 (silica), have several chemical forms in solution. Silica is a nutrient for diatoms, which are phytoplankton in oceans. Silica species can be used as a tracer to examine the behavior of silica in nature. The speciation for silica by FAB-MS (fast atom bombardment mass spectrometry) has been carried out for seawater samples from Tokyo Bay and Sagami Bay to investigate the seasonal and locational changes of the depth profiles of silica species. The species, [Si(OH)2O2Na+]-, [Si2(OH)5O2]- ([dimer]-), [Si2(OH)4O3Na+]-, [Si(OH)7O5-] ([cyclic tetramer]-), [Si4(OH)6O6Na+]-, [Si(OH)9O]- ([linear tetramer]-) and [Si4(OH)8O5Na+]- were mainly identified by FAB-MS. The seasonal and locational changes and the reproducibility of depth profiles of silica species were determined from October 2001 to July 2002. The depth profile of the ratio of linear tetramer to cyclic tetramer reflects the activity of diatoms, implying that the linear tetramer is the preferred "food" for diatoms. In particular, the depth profile for the ratio of linear tetramer to cyclic tetramer exhibits a critical changes that depend on the season. Furthermore, the depth profiles for the samples from Sagami Bay (open ocean) indicate that seawater is easily exchanged by ocean currents (the Japan Current). Thus, silica speciation by FAB-MS can give us a new tracer indicating the characteristics of the seawater budget, which change with depth, season and ocean locality.

  16. Seasonal changes in the atmospheric heat balance simulated by the GISS general circulation model

    Science.gov (United States)

    Stone, P. H.; Chow, S.; Helfand, H. M.; Quirk, W. J.; Somerville, R. C. J.

    1975-01-01

    Tests of the ability of numerical general circulation models to simulate the atmosphere have focussed so far on simulations of the January climatology. These models generally present boundary conditions such as sea surface temperature, but this does not prevent testing their ability to simulate seasonal changes in atmospheric processes that accompany presented seasonal changes in boundary conditions. Experiments to simulate changes in the zonally averaged heat balance are discussed since many simplified models of climatic processes are based solely on this balance.

  17. The influence of crop production and socioeconomic factors on seasonal household dietary diversity in Burkina Faso.

    Science.gov (United States)

    Somé, Jérôme W; Jones, Andrew D

    2018-01-01

    Households in low-income settings are vulnerable to seasonal changes in dietary diversity because of fluctuations in food availability and access. We assessed seasonal differences in household dietary diversity in Burkina Faso, and determined the extent to which household socioeconomic status and crop production diversity modify changes in dietary diversity across seasons, using data from the nationally representative 2014 Burkina Faso Continuous Multisectoral Survey (EMC). A household dietary diversity score based on nine food groups was created from household food consumption data collected during four rounds of the 2014 EMC. Plot-level crop production data, and data on household assets and education were used to create variables on crop diversity and household socioeconomic status, respectively. Analyses included data for 10,790 households for which food consumption data were available for at least one round. Accounting for repeated measurements and controlling for the complex survey design and confounding covariates using a weighted multi-level model, household dietary diversity was significantly higher during both lean seasons periods, and higher still during the harvest season as compared to the post-harvest season (mean: post-harvest: 4.76 (SE 0.04); beginning of lean: 5.13 (SE 0.05); end of lean: 5.21 (SE 0.05); harvest: 5.72 (SE 0.04)), but was not different between the beginning and the end of lean season. Seasonal differences in household dietary diversity were greater among households with higher food expenditures, greater crop production, and greater monetary value of crops sale (P<0.05). Seasonal changes in household dietary diversity in Burkina Faso may reflect nutritional differences among agricultural households, and may be modified both by households' socioeconomic status and agricultural characteristics.

  18. ANAEROBIC CAPACITY OF AMATEUR MOUNTAIN BIKERS DURING THE FIRST HALF OF THE COMPETITION SEASON

    Directory of Open Access Journals (Sweden)

    Ryszard Jarosław Zarzeczny

    2013-06-01

    Full Text Available Sustained aerobic exercise not only affects the rate of force development but also decreases peak power development. The aim of this study was to investigate whether anaerobic power of amateur mountain bikers changes during the first half of the competition season. Eight trained cyclists (mean ± SE: age: 22.0 ±0.5 years; height: 174.6 ± 0.9 cm; weight: 70.7 ± 2.6 kg were subjected to an ergocycle incremental exercise test and to the Wingate test on two occasions: before, and in the middle of the season. After the incremental exercise test the excess post-exercise oxygen consumption was measured during 5-min recovery. Blood lactate concentration was measured in the 4th min after the Wingate test. Maximum oxygen uptake increased from 60.0 ± 1.5 ml · min-1 · kg-1 at the beginning of the season to 65.2 ± 1.4 ml · min-1 · kg-1 (P<0.05 in the season. Neither of the mechanical variables of the Wingate test nor excess post-exercise oxygen consumption values were significantly different in these two measurements. However, blood lactate concentration was significantly higher (P<0.001 in season (11.0 ± 0.5 mM than before the season (8.6 ± 0.4 mM. It is concluded that: 1 despite the increase of cyclists’ maximum oxygen uptake during the competition season their anaerobic power did not change; 2 blood lactate concentration measured at the 4th min after the Wingate test does not properly reflect training-induced changes in energy metabolism.

  19. The Structures of the Alternative Conceptions of Preservice Secondary Teachers on Seasonal Changes

    Directory of Open Access Journals (Sweden)

    Junyoung Oh

    2005-03-01

    Full Text Available This study was to understand the components that influence preservice secondary teachers' conceptions about "seasonal changes". We selected 74 university science education students among whom 23 were in the second, 23 in the third, and 28 in the fourth year. The data collected from the paper-pencil test and individual interview with students. The results of this study show that the students had considerable apparent alternative conceptions, and that the 'distance theory' had most important effects on their alternative conceptions. It can be said that preservice secondary teachers' initial models of the seasonal change have their origin in their belief sets (specific theory related to 'seasonal change', on the basis of which they can interpret their observations and cultural information with the constraints of a naive framework of physics. The structures and possible sources of their alternative conceptions for overcoming these alternative conceptions were also discussed. Implications for preservice science teacher education related to the results were discussed.

  20. Seasonal analysis of precipitation, drought and Vegetation index in Indonesian paddy field based on remote sensing data

    International Nuclear Information System (INIS)

    Darmawan, S; Takeuchi, W; Shofiyati, R; Sari, D K; Wikantika, K

    2014-01-01

    Paddy field is important agriculture crop in Indonesia. Rice is a food staple for 237,6 million Indonesian people. Paddy field growth is strongly influenced by water, but the amount of precipitation is unpredictable. Annual and interannual climate variability in Indonesia is unusual. In recent years remote sensing data has been used for measurement and monitoring of precipitation, drought and Vegetation index such as Global Satellite Mapping of Precipitation (GSMaP), Multi-purpose Transmission SATellite (MTSAT) and Moderate Resolution Imaging Spectroradiometer (MODIS). The objective of this research is to investigate seasonal variability of precipitation, drought and Vegetation index in Indonesian paddy field based on remote sensing data. The methodology consists of collecting of enhanced vegetation index (EVI) from MODIS data, mosaicking of image, collecting of region of interest of paddy field, collecting of precipitation and drought index based on Keetch Bryam Drought Index (KBDI) from GSMaP and MTSAT, and seasonal analysis. The result of this research has showed seasonal variability of precipitation, KBDI and EVI on Indonesia paddy field from 2007 until 2012. Precipitation begins from January until May and October until December, and KBDI begins to increase from June and peak in September only in South Sumatera precipitation almost in all month. Seasonal analysis has showed precipitation and KBDI affect on EVI that can indicate variety phenology of Indonesian paddy field. Peak of EVI occurs before peak of KBDI occurs and increasing of KBDI followed by decreasing of EVI. In 2010 all province got higher precipitation and smaller KBDI so EVI has three peaks such as in West Java that can indicated increasing of rice production

  1. Updates to Post-Flash Calibration for the Advanced Camera for Surveys Wide Field Channel

    Science.gov (United States)

    Miles, Nathan

    2018-03-01

    This report presents a new technique for generating the post-flash calibration reference file for the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC). The new method substantially reduces, if not, eliminates all together the presence of dark current artifacts arising from improper dark subtraction, while simultaneously preserving flat-field artifacts. The stability of the post-flash calibration reference file over time is measured using data taken yearly since 2012 and no statistically significant deviations are found. An analysis of all short-flashed darks taken every two days since January 2015 reveals a periodic modulation of the LED intensity on timescales of about one year. This effect is most readily explained by changes to the local temperature in the area surrounding the LED. However, a slight offset between the periods of the temperature and LED modulations lends to the possibility that the effect is a chance observation of the two sinusoids at an unfortunate point in their beat cycle.

  2. Decoupling Seasonal Changes in Water Content and Dry Matter to Predict Live Conifer Foliar Moisture Content.

    OpenAIRE

    Jolly, W. M.; Hadlow, A. M.; Huguet, K.

    2014-01-01

    Live foliar moisture content (LFMC) significantly influences wildland fire behaviour. However, characterising variations in LFMC is difficult because both foliar mass and dry mass can change throughout the season. Here we quantify the seasonal changes in both plant water status and dry matter partitioning. We collected new and old foliar samples fromPinus contorta for two growing seasons and quantified their LFMC, relative water content (RWC) and dry matter chemistry. LFMC quantifies the amou...

  3. Lake seasonality across the Tibetan Plateau and their varying relationship with regional mass changes and local hydrology

    Science.gov (United States)

    Lei, Yanbin; Yao, Tandong; Yang, Kun; Sheng, Yongwei; Kleinherenbrink, Marcel; Yi, Shuang; Bird, Broxton W.; Zhang, Xiaowen; Zhu, La; Zhang, Guoqing

    2017-01-01

    The recent growth and deepening of inland lakes in the Tibetan Plateau (TP) may be a salient indicator of the consequences of climate change. The seasonal dynamics of these lakes is poorly understood despite this being potentially crucial for disentangling contributions from glacier melt and precipitation, which are all sensitive to climate, to lake water budget. Using in situ observations, satellite altimetry and gravimetry data, we identified two patterns of lake level seasonality. In the central, northern, and northeastern TP, lake levels are characterized by considerable increases during warm seasons and decreases during cold seasons, which is consistent with regional mass changes related to monsoon precipitation and evaporation. In the northwestern TP, however, lake levels exhibit dramatic increases during both warm and cold seasons, which deviate from regional mass changes. This appears to be more connected with high spring snowfall and large summer glacier melt. The variable lake level response to different drivers indicates heterogeneous sensitivity to climate change between the northwestern TP and other regions.

  4. Household transmission of influenza A(H1N1pdm09 in the pandemic and post-pandemic seasons.

    Directory of Open Access Journals (Sweden)

    Itziar Casado

    Full Text Available The transmission of influenza viruses occurs person to person and is facilitated by contacts within enclosed environments such as households. The aim of this study was to evaluate secondary attack rates and factors associated with household transmission of laboratory-confirmed influenza A(H1N1pdm09 in the pandemic and post-pandemic seasons.During the 2009-2010 and 2010-2011 influenza seasons, 76 sentinel physicians in Navarra, Spain, took nasopharyngeal and pharyngeal swabs from patients diagnosed with influenza-like illness. A trained nurse telephoned households of those patients who were laboratory-confirmed for influenza A(H1N1pdm09 to ask about the symptoms, risk factors and vaccination status of each household member.In the 405 households with a patient laboratory-confirmed for influenza A(H1N1pdm09, 977 susceptible contacts were identified; 16% of them (95% CI 14-19% presented influenza-like illness and were considered as secondary cases. The secondary attack rate was 14% in 2009-2010 and 19% in the 2010-2011 season (p=0.049, an increase that mainly affected persons with major chronic conditions. In the multivariate logistic regression analysis, the risk of being a secondary case was higher in the 2010-2011 season than in the 2009-2010 season (adjusted odds ratio: 1.72; 95% CI 1.17-2.54, and in children under 5 years, with a decreasing risk in older contacts. Influenza vaccination was associated with lesser incidence of influenza-like illness near to statistical significance (adjusted odds ratio: 0.29; 95% CI 0.08-1.03.The secondary attack rate in households was higher in the second season than in the first pandemic season. Children had a greater risk of infection. Preventive measures should be maintained in the second pandemic season, especially in high-risk persons.

  5. The changing seasonal climate in the Arctic.

    Science.gov (United States)

    Bintanja, R; van der Linden, E C

    2013-01-01

    Ongoing and projected greenhouse warming clearly manifests itself in the Arctic regions, which warm faster than any other part of the world. One of the key features of amplified Arctic warming concerns Arctic winter warming (AWW), which exceeds summer warming by at least a factor of 4. Here we use observation-driven reanalyses and state-of-the-art climate models in a variety of standardised climate change simulations to show that AWW is strongly linked to winter sea ice retreat through the associated release of surplus ocean heat gained in summer through the ice-albedo feedback (~25%), and to infrared radiation feedbacks (~75%). Arctic summer warming is surprisingly modest, even after summer sea ice has completely disappeared. Quantifying the seasonally varying changes in Arctic temperature and sea ice and the associated feedbacks helps to more accurately quantify the likelihood of Arctic's climate changes, and to assess their impact on local ecosystems and socio-economic activities.

  6. Denitrification in agriculturally impacted streams: seasonal changes in structure and function of the bacterial community.

    Directory of Open Access Journals (Sweden)

    Erin Manis

    Full Text Available Denitrifiers remove fixed nitrogen from aquatic environments and hydrologic conditions are one potential driver of denitrification rate and denitrifier community composition. In this study, two agriculturally impacted streams in the Sugar Creek watershed in Indiana, USA with different hydrologic regimes were examined; one stream is seasonally ephemeral because of its source (tile drainage, whereas the other stream has permanent flow. Additionally, a simulated flooding experiment was performed on the riparian benches of the ephemeral stream during a dry period. Denitrification activity was assayed using the chloramphenicol amended acetylene block method and bacterial communities were examined based on quantitative PCR and terminal restriction length polymorphisms of the nitrous oxide reductase (nosZ and 16S rRNA genes. In the stream channel, hydrology had a substantial impact on denitrification rates, likely by significantly lowering water potential in sediments. Clear patterns in denitrification rates were observed among pre-drying, dry, and post-drying dates; however, a less clear scenario was apparent when analyzing bacterial community structure suggesting that denitrifier community structure and denitrification rate were not strongly coupled. This implies that the nature of the response to short-term hydrologic changes was physiological rather than increases in abundance of denitrifiers or changes in composition of the denitrifier community. Flooding of riparian bench soils had a short-term, transient effect on denitrification rate. Our results imply that brief flooding of riparian zones is unlikely to contribute substantially to removal of nitrate (NO3- and that seasonal drying of stream channels has a negative impact on NO3- removal, particularly because of the time lag required for denitrification to rebound. This time lag is presumably attributable to the time required for the denitrifiers to respond physiologically rather than a change

  7. Recent Changes in the Arctic Melt Season

    Science.gov (United States)

    Stroeve, Julienne; Markus, Thorsten; Meier, Walter N.; Miller, Jeff

    2007-01-01

    Melt-season duration, melt-onset and freeze-up dates are derived from satellite passive microwave data and analyzed from 1979 to 2005 over Arctic sea ice. Results indicate a shift towards a longer melt season, particularly north of Alaska and Siberia, corresponding to large retreats of sea ice observed in these regions. Although there is large interannual and regional variability in the length of the melt season, the Arctic is experiencing an overall lengthening of the melt season at a rate of about 2 weeks decade(sup -1). In fact, all regions in the Arctic (except for the central Arctic) have statistically significant (at the 99% level or higher) longer melt seasons by greater than 1 week decade(sup -1). The central Arctic shows a statistically significant trend (at the 98% level) of 5.4 days decade(sup -1). In 2005 the Arctic experienced its longest melt season, corresponding with the least amount of sea ice since 1979 and the warmest temperatures since the 1880s. Overall, the length of the melt season is inversely correlated with the lack of sea ice seen in September north of Alaska and Siberia, with a mean correlation of -0.8.

  8. Changes in seasonal climate outpace compensatory density-dependence in eastern brook trout

    Science.gov (United States)

    Bassar, Ronald D.; Letcher, Benjamin H.; Nislow, Keith H.; Whiteley, Andrew R.

    2016-01-01

    Understanding how multiple extrinsic (density-independent) factors and intrinsic (density-dependent) mechanisms influence population dynamics has become increasingly urgent in the face of rapidly changing climates. It is particularly unclear how multiple extrinsic factors with contrasting effects among seasons are related to declines in population numbers and changes in mean body size and whether there is a strong role for density-dependence. The primary goal of this study was to identify the roles of seasonal variation in climate driven environmental direct effects (mean stream flow and temperature) versus density-dependence on population size and mean body size in eastern brook trout (Salvelinus fontinalis). We use data from a 10-year capture-mark-recapture study of eastern brook trout in four streams in Western Massachusetts, USA to parameterize a discrete-time population projection model. The model integrates matrix modeling techniques used to characterize discrete population structures (age, habitat type and season) with integral projection models (IPMs) that characterize demographic rates as continuous functions of organismal traits (in this case body size). Using both stochastic and deterministic analyses we show that decreases in population size are due to changes in stream flow and temperature and that these changes are larger than what can be compensated for through density-dependent responses. We also show that the declines are due mostly to increasing mean stream temperatures decreasing the survival of the youngest age class. In contrast, increases in mean body size over the same period are the result of indirect changes in density with a lesser direct role of climate-driven environmental change.

  9. Performance changes in National Collegiate Athletic Association Division I women basketball players during a competitive season: starters vs. nonstarters.

    Science.gov (United States)

    Gonzalez, Adam M; Hoffman, Jay R; Scallin-Perez, Jennifer R; Stout, Jeffrey R; Fragala, Maren S

    2012-12-01

    The effects of playing time on performance changes were examined in National Collegiate Athletic Association Division I women basketball players. Twelve basketball players (age = 20.6 ± 1.5 years; height = 178.0 ± 8.2 cm; weight = 74.1 ± 8.1 kg) were assessed before (PRE) and at the end of the regular basketball season (POST). Assessments included squat power; vertical jump (VJ) power; 20-second lower-body reaction test; 3 line drills; and subjective measures of energy, focus, fatigue, and alertness. Pre- to postseason comparisons were made between starters (28.3 ± 5.2 minutes per game) and nonstarters (NSs) (8.3 ± 5.3 minutes per game). Data were analyzed for clinical significance using an approach based on the magnitude of change. Results revealed that starters were likely to have greater increases in absolute VJ peak power and relative VJ peak power (87.9 and 90.7%, respectively) and they were likely (81.6%) to have a greater average squat power than NSs. Subjective measures of energy, focus, and alertness were possibly (72.9%), very likely (97.3%), and likely (79.2%) to be lower in starters compared with NSs, respectively. Other performance measures showed unclear differences between starters and NSs. Pearson's product-moment correlation analysis revealed significant (p basketball season.

  10. Seasonal variability of rocky reef fish assemblages: Detecting functional and structural changes due to fishing effects

    Science.gov (United States)

    Henriques, Sofia; Pais, Miguel Pessanha; Costa, Maria José; Cabral, Henrique Nogueira

    2013-05-01

    The present study analyzed the effects of seasonal variation on the stability of fish-based metrics and their capability to detect changes in fish assemblages, which is yet poorly understood despite the general idea that guilds are more resilient to natural variability than species abundances. Three zones subject to different levels of fishing pressure inside the Arrábida Marine Protected Area (MPA) were sampled seasonally. The results showed differences between warm (summer and autumn) and cold (winter and spring) seasons, with the autumn clearly standing out. In general, the values of the metrics density of juveniles, density of invertebrate feeders and density of omnivores increased in warm seasons, which can be attributed to differences in recruitment patterns, spawning migrations and feeding activity among seasons. The density of generalist/opportunistic individuals was sensitive to the effect of fishing, with higher values at zones with the lowest level of protection, while the density of individuals with high commercial value only responded to fishing in the autumn, due to a cumulative result of both juveniles and adults abundances during this season. Overall, this study showed that seasonal variability affects structural and functional features of the fish assemblage and that might influence the detection of changes as a result of anthropogenic pressures. The choice of a specific season, during warm sea conditions after the spawning period (July-October), seems to be more adequate to assess changes on rocky-reef fish assemblages.

  11. Greenhouse Gas Induced Changes in the Seasonal Cycle of the Amazon Basin in Coupled Climate-Vegetation Regional Model

    Directory of Open Access Journals (Sweden)

    Flavio Justino

    2016-01-01

    Full Text Available Previous work suggests that changes in seasonality could lead to a 70% reduction in the extent of the Amazon rainforest. The primary cause of the dieback of the rainforest is a lengthening of the dry season due to a weakening of the large-scale tropical circulation. Here we examine these changes in the seasonal cycle. Under present day conditions the Amazon climate is characterized by a zonal separation of the dominance of the annual and semi-annual seasonal cycles. This behavior is strongly modified under greenhouse warming conditions, with the annual cycle becoming dominant throughout the Amazon basin, increasing differences between the dry and wet seasons. In particular, there are substantial changes in the annual cycle of temperature due to the increase in the temperature of the warmest month, but the lengthening of the dry season is believed to be particularly important for vegetation-climate feedbacks. Harmonic analysis performed to regional climate model simulations yields results that differ from the global climate model that it is forced from, with the regional model being more sensitive to changes in the seasonal cycle.

  12. CMIP5 model simulations of Ethiopian Kiremt-season precipitation: current climate and future changes

    Science.gov (United States)

    Li, Laifang; Li, Wenhong; Ballard, Tristan; Sun, Ge; Jeuland, Marc

    2016-05-01

    Kiremt-season (June-September) precipitation provides a significant water supply for Ethiopia, particularly in the central and northern regions. The response of Kiremt-season precipitation to climate change is thus of great concern to water resource managers. However, the complex processes that control Kiremt-season precipitation challenge the capability of general circulation models (GCMs) to accurately simulate precipitation amount and variability. This in turn raises questions about their utility for predicting future changes. This study assesses the impact of climate change on Kiremt-season precipitation using state-of-the-art GCMs participating in the Coupled Model Intercomparison Project Phase 5. Compared to models with a coarse resolution, high-resolution models (horizontal resolution <2°) can more accurately simulate precipitation, most likely due to their ability to capture precipitation induced by topography. Under the Representative Concentration Pathway (RCP) 4.5 scenario, these high-resolution models project an increase in precipitation over central Highlands and northern Great Rift Valley in Ethiopia, but a decrease in precipitation over the southern part of the country. Such a dipole pattern is attributable to the intensification of the North Atlantic subtropical high (NASH) in a warmer climate, which influences Ethiopian Kiremt-season precipitation mainly by modulating atmospheric vertical motion. Diagnosis of the omega equation demonstrates that an intensified NASH increases (decreases) the advection of warm air and positive vorticity into the central Highlands and northern Great Rift Valley (southern part of the country), enhancing upward motion over the northern Rift Valley but decreasing elsewhere. Under the RCP 4.5 scenario, the high-resolution models project an intensification of the NASH by 15 (3 × 105 m2 s-2) geopotential meters (stream function) at the 850-hPa level, contributing to the projected precipitation change over Ethiopia. The

  13. A T1 and DTI fused 3D corpus callosum analysis in pre- vs. post-season contact sports players

    Science.gov (United States)

    Lao, Yi; Law, Meng; Shi, Jie; Gajawelli, Niharika; Haas, Lauren; Wang, Yalin; Leporé, Natasha

    2015-01-01

    Sports related traumatic brain injury (TBI) is a worldwide public health issue, and damage to the corpus callosum (CC) has been considered as an important indicator of TBI. However, contact sports players suffer repeated hits to the head during the course of a season even in the absence of diagnosed concussion, and less is known about their effect on callosal anatomy. In addition, T1-weighted and diffusion tensor brain magnetic resonance images (DTI) have been analyzed separately, but a joint analysis of both types of data may increase statistical power and give a more complete understanding of anatomical correlates of subclinical concussions in these athletes. Here, for the first time, we fuse T1 surface-based morphometry and a new DTI analysis on 3D surface representations of the CCs into a single statistical analysis on these subjects. Our new combined method successfully increases detection power in detecting differences between pre- vs. post-season contact sports players. Alterations are found in the ventral genu, isthmus, and splenium of CC. Our findings may inform future health assessments in contact sports players. The new method here is also the first truly multimodal diffusion and T1-weighted analysis of the CC, and may be useful to detect anatomical changes in the corpus callosum in other multimodal datasets.

  14. Post-seismic velocity changes following the 2010 Mw 7.1 Darfield earthquake, New Zealand, revealed by ambient seismic field analysis

    Science.gov (United States)

    Heckels, R. EG; Savage, M. K.; Townend, J.

    2018-05-01

    Quantifying seismic velocity changes following large earthquakes can provide insights into fault healing and reloading processes. This study presents temporal velocity changes detected following the 2010 September Mw 7.1 Darfield event in Canterbury, New Zealand. We use continuous waveform data from several temporary seismic networks lying on and surrounding the Greendale Fault, with a maximum interstation distance of 156 km. Nine-component, day-long Green's functions were computed for frequencies between 0.1 and 1.0 Hz for continuous seismic records from immediately after the 2010 September 04 earthquake until 2011 January 10. Using the moving-window cross-spectral method, seismic velocity changes were calculated. Over the study period, an increase in seismic velocity of 0.14 ± 0.04 per cent was determined near the Greendale Fault, providing a new constraint on post-seismic relaxation rates in the region. A depth analysis further showed that velocity changes were confined to the uppermost 5 km of the subsurface. We attribute the observed changes to post-seismic relaxation via crack healing of the Greendale Fault and throughout the surrounding region.

  15. Recent changes in seasonal variations of climate within the range of northern caribou populations

    Directory of Open Access Journals (Sweden)

    Paul H. Whitfield

    2005-05-01

    Full Text Available The Arctic is one region where it is expected that the impacts of a globally changing climate will be readily observed. We present results that indicate that climate derivatives of potential significance to caribou changed during the past 50 years. Many temperature derivatives reflect the increasing overall temperature in the Arctic such as decreases in the number of days with low temperatures, increases in the number of days with thaw, and days with extremely warm temperatures. Other derivatives reflect changes in the precipitation regime such as days with heavy precipitation and number of days when rain fell on snow. Our results indicate that specific caribou herds from across the Arctic were subjected to different variations of these derivatives in different seasons in the recent past. Examination of temperature and precipitation at finer time-steps than annual or monthly means, shows that climatic variations in the region are neither consistent through the seasons nor across space. Decadal changes in seasonal patterns of temperature and precipitation are shown for selected herds. A process for assessing caribou-focused climate derivatives is proposed.

  16. Seasonal prolactin secretion and its role in seasonal reproduction: a review.

    Science.gov (United States)

    Curlewis, J D

    1992-01-01

    The majority of seasonally breeding mammals show a seasonal pattern of prolactin secretion with peak concentrations in spring or summer and a nadir in autumn or winter. Photoperiod influences prolactin secretion via its effects on the secretion of the pineal hormone melatonin. Preliminary evidence suggests that the effects of melatonin on both prolactin and gonadotrophin secretion are via a common target area, possibly within the anterior hypothalamus, and that differences in response to photoperiod may be due to differences in the processing and/or interpretation of the melatonin signal. In contrast to seasonal gonadotrophin secretion, the seasonal changes in prolactin are not due to changes in the sensitivity of a feedback loop and so must be due to direct effects on the hypothalamic pathways that control prolactin secretion. Little else can be said with confidence about the neuroendocrine mechanisms that lead to the seasonal changes in prolactin secretion. Dopamine and noradrenaline turnover in the arcuate nucleus and median eminence decrease under short daylength. If catecholamine turnover in these structures is positively correlated with catecholamine concentrations in the long or short hypophysial portal vessels, it is unlikely that the decrease in prolactin concentration in winter is due to the effects of increased concentrations of dopamine or noradrenaline in the portal vessels. There is, however, evidence for increased pituitary sensitivity to dopamine under short daylength, so increased dopamine concentrations may not be required for suppression of prolactin secretion at this time. In addition to the diminished secretion of prolactin under short daylength, rate of prolactin synthesis and pituitary content of prolactin also decline although the mechanisms that regulate these changes are poorly understood. Although all seasonal breeders show a seasonal change in prolactin secretion, there are continuously breeding species in which prolactin secretion is

  17. High NDVI and Potential Canopy Photosynthesis of South American Subtropical Forests despite Seasonal Changes in Leaf Area Index and Air Temperature

    Directory of Open Access Journals (Sweden)

    Piedad M. Cristiano

    2014-02-01

    Full Text Available The canopy photosynthesis and carbon balance of the subtropical forests are not well studied compared to temperate and tropical forest ecosystems. The main objective of this study was to assess the seasonal dynamics of Normalized Difference Vegetation Index (NDVI and potential canopy photosynthesis in relation to seasonal changes in leaf area index (LAI, chlorophyll concentration, and air temperatures of NE Argentina subtropical forests throughout the year. We included in the analysis several tree plantations (Pinus, Eucalyptus and Araucaria species that are known to have high productivity. Field studies in native forests and tree plantations were conducted; stem growth rates, LAI and leaf chlorophyll concentration were measured. MODIS satellite-derived LAI (1 km SIN Grid and NDVI (250m SIN Grid from February 2000 to 2012 were used as a proxy of seasonal dynamics of potential photosynthetic activity at the stand level. The remote sensing LAI of the subtropical forests decreased every year from 6 to 5 during the cold season, similar to field LAI measurements, when temperatures were 10 °C lower than during the summer. The yearly maximum NDVI values were observed during a few months in autumn and spring (March through May and November, respectively because high and low air temperatures may have a small detrimental effect on photosynthetic activity during both the warm and the cold seasons. Leaf chlorophyll concentration was higher during the cold season than the warm season which may have a compensatory effect on the seasonal variation of the NDVI values. The NDVI of the subtropical forest stands remained high and fairly constant throughout the year (the intra-annual coefficient of variation was 1.9%, and were comparable to the values of high-yield tree plantations. These results suggest that the humid subtropical forests in NE Argentina potentially could maintain high canopy photosynthetic activity throughout the year and thus this ecosystem may

  18. Changing fields of rationality - a policy for change?

    Energy Technology Data Exchange (ETDEWEB)

    Strumse, Einar; Westskog, Hege; Winther, Tanja

    2010-07-01

    Work objective: To analyze effective strategies for changing households' energy consumption based on an interdisciplinary model for understanding change. Methodology: In this paper we develop a conceptual model for understanding individuals' energy consumption. We synthesize insights from anthropology, social psychology and economics grasping perspectives from behaviour to practice and from the Bourdieu's fields to rationality thinking in economics. We use this insight to analyze strategies for change. Abstract: In this paper we analyze effective strategies for changing households' energy consumption based on an interdisciplinary model for understanding change. The model focuses on four main categories for understanding individual consumption: a. Material constraints b. Values and identity c. Norms d. Ability These are the main influencing factors of the individual's consumption level, but in interaction with the corresponding group and the societal levels for the same factors. The model can be illustrated. One combination of factors on all levels constitutes a field of rationality. We claim that an important strategy for changing energy consumption towards sustainability is changing the field of rationality of the individual. Changing of rationality fields would from our point of view initiate reflection which is an important condition for changed behavior. One example of changing of fields is information measures that relates energy consumption to the 'citizen' field rather than the 'consumer' field. Hence, according to our conceptual framework - how policy should be framed (information measures for instance ) would be an important knowledge area for design of effective policy measures. (Author)

  19. Greenhouse Gas Induced Changes in the Seasonal Cycle of the Amazon Basin in Coupled Climate-Vegetation Regional Model

    OpenAIRE

    Flavio Justino; Frode Stordal; Edward K. Vizy; Kerry H. Cook; Marcos P. S. Pereira

    2016-01-01

    Previous work suggests that changes in seasonality could lead to a 70% reduction in the extent of the Amazon rainforest. The primary cause of the dieback of the rainforest is a lengthening of the dry season due to a weakening of the large-scale tropical circulation. Here we examine these changes in the seasonal cycle. Under present day conditions the Amazon climate is characterized by a zonal separation of the dominance of the annual and semi-annual seasonal cycles. This behavior is strongly ...

  20. Monitoring and assessment of seasonal land cover changes using remote sensing: a 30-year (1987-2016) case study of Hamoun Wetland, Iran.

    Science.gov (United States)

    Kharazmi, Rasoul; Tavili, Ali; Rahdari, Mohammad Reza; Chaban, Lyudmila; Panidi, Evgeny; Rodrigo-Comino, Jesús

    2018-05-23

    The availability of Landsat data allows improving the monitoring and assessment of large-scale areas with land cover changes in rapid developing regions. Thus, we pretend to show a combined methodology to assess land cover changes (LCCs) in the Hamoun Wetland region (Iran) over a period of 30-year (1987-2016) and to quantify seasonal and decadal landscape and land use variabilities. Using the pixel-based change detection (PBCD) and the post-classification comparison (PCC), four land cover classes were compared among spring, summer, and fall seasons. Our findings showed for the water class a higher correlation between spring and summer (R 2  = 0.94) than fall and spring (R 2  = 0.58) seasons. Before 2000, ~ 50% of the total area was covered by bare soil and 40% by water. However, after 2000, more than 70% of wetland was transformed into bare soils. The results of the long-term monitoring period showed that fall season was the most representative time to show the inter-annual variability of LCCs monitoring and the least affected by seasonal-scale climatic variations. In the Hamoun Wetland region, land cover was highly controlled by changes in surface water, which in turn responded to both climatic and anthropogenic impacts. We were able to divide the water budget monitoring into three different ecological regimes: (1) a period of high water level, which sustained healthy extensive plant life, and approximately 40% of the total surface water was retained until the end of the hydrological year; (2) a period of drought during high evaporation rates was observed, and a mean wetland surface of about 85% was characterized by bare land; and (3) a recovery period in which water levels were overall rising, but they are not maintained from year to year. After a spring flood, in 2006 and 2013, grassland reached the highest extensions, covering till more than 20% of the region, and the dynamics of the ecosystem were affected by the differences in moisture. The Hamoun

  1. Seasonal changes in water metabolism of Sudan desert sheep and goats

    International Nuclear Information System (INIS)

    El Hadi, H.M.; Hassan, Y.M.

    1982-01-01

    Seasonal changes that occur in body weight, body temperature, total body water and water turnover were investigated in grazing sheep and goats at different times of the year to understand how different breeds adapt to the environmental conditions in Sudan. (author)

  2. Effect of system of lamb rearing and season on early post-partum fertility of ewes and growth performance of lambs in Katahdin sheep.

    Science.gov (United States)

    Rastle-Simpson, S; D'Souza, K; Redhead, A; Singh-Knights, D; Baptiste, Q; Knights, M

    2017-10-01

    The effect of season (S), lamb rearing system (RT) and grain supplementation (GS) on post-partum fertility in Katahdin ewes and growth in Katahdin lambs was evaluated. Katahdin ewes were bred to lamb in fall (n = 36) or spring (n = 56) and at approximately 2.5 months post-partum were randomly assigned to be permanently separated or to continue to suckle their lambs for an additional 3 months. All ewes were joined with rams following treatment to synchronize oestrus. Weaned (W, n = 84) and continuously suckled lambs (CSK, n = 88) were fed forage only (n = 84; hay and pasture for fall- and spring-born lambs respectively) or were supplemented (n = 88; 18% crude protein ration ad libitum) and all weighed biweekly. Ewes rebred in the fall had a shorter ram introduction to lambing interval (p ewes lambing was not affected by season. The first service lambing rate was lower in ewes continuously suckling lambs in the spring, but not in the fall breeding season (S × RT, p = 0.03). Lambs that continuously suckled their dams and were supplemented grew quicker and gained more (p ewes are capable of early rebreeding post-partum while suckling their lambs, which makes them suited for use in accelerated lambing programmes. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  3. Retrospective assessment of seasonal allergic symptoms

    DEFF Research Database (Denmark)

    Bodtger, U; Poulsen, Lars K.; Malling, H-J

    2003-01-01

    The history of the severity of seasonal allergic symptoms is often obtained post-seasonally as a retrospective assessment. Correct rating is essential when determining the efficacy of pharmaceutical treatment, indications for allergen-specific immunotherapy (SIT), or inclusion into controlled cli...

  4. Modeling seasonal changes of atmospheric carbon dioxide and carbon 13

    International Nuclear Information System (INIS)

    Gillette, D.A.; Box, E.O.

    1986-01-01

    A two-dimensional (latitude-altitude) model of atmospheric CO 2 and δ 13 C was constructed to simulate some features of seasonal carbon cycle fluctuations. The model simulates air-sea exchange, atmospheric diffusion, and fossil fuel carbon sources, which are functions of time and latitude. In addition, it uses biosphere-atmosphere fluxes of carbon that are based on global-scale biological models of vegetation growth and decay. Results of the model show fair agreement with observational results for CO 2 and δ 13 C seasonal fluctuations. Their model results have far northern fluctuations with smaller amplitudes than are observed. Analysis of sources of CO 2 change at given latitudes shows that, for far southern latitudes, southern hemisphere biospheric fluxes are dominant in affecting the seasonal CO 2 fluctuations. Long-term decrease of δ 13 C for the model is larger than for observations. This may be due to errors in the formulation for oceanic fluxes for 13 C in the model or to a net uptake of carbon by the biosphere

  5. Non-climatic factors and long-term, continental-scale changes in seasonally frozen ground

    Science.gov (United States)

    Shiklomanov, Nikolay I.

    2012-03-01

    Numerous studies indicate that the northern high latitudes are experiencing an unprecedented rate of environmental change, including an increase in air temperatures (e.g. Serreze and Francis 2006), reduction of snow cover (e.g. Brown and Robinson 2011), ecosystem transformations and land cover changes (e.g. Callaghan et al 2011). Many of the potential environmental impacts of global warming in the high latitudes are associated with frozen ground, which occupies about 55% of the unglaciated land area in the northern hemisphere and consists of both permafrost and seasonally frozen ground. Frozen soils have a tremendous impact on hydrologic, climatic and biologic systems. Periodic freezing and thawing promote changes in soil structure, affect the surface and subsurface water cycle, and regulate the availability of nutrients in the soil for plants and biota that depend upon them. Freezing and thawing cycles can affect the decomposition of organic substances in the soil and greenhouse gas exchange between the atmosphere and land surface. Significant efforts have been devoted to permafrost-related studies, including the establishment of standardized observations (e.g. Romanovsky et al 2010, Shiklomanov et al 2008), modeling (e.g. Riseborough et al 2008), and climate-related feedback processes (e.g. Schuur et al 2008). Despite its vast extent and importance, seasonally frozen ground has received much less attention. One of the major obstacles in assessing changes in seasonally frozen ground is the lack of long-term data. In general, observations on soil temperature and freeze propagation are available for a limited area and involve a relatively short time period, precluding assessment of long-term, climate-driven change. A few known exceptions include shallow soil temperature and freeze/thaw depth observations conducted as part of the standard hydrometeorological monitoring system in China (e.g. Zhao et al 2004) and the Soviet Union/Russia (e.g. Gilichinsky et al 2000

  6. Visual long-term memory and change blindness: Different effects of pre- and post-change information on one-shot change detection using meaningless geometric objects.

    Science.gov (United States)

    Nishiyama, Megumi; Kawaguchi, Jun

    2014-11-01

    To clarify the relationship between visual long-term memory (VLTM) and online visual processing, we investigated whether and how VLTM involuntarily affects the performance of a one-shot change detection task using images consisting of six meaningless geometric objects. In the study phase, participants observed pre-change (Experiment 1), post-change (Experiment 2), or both pre- and post-change (Experiment 3) images appearing in the subsequent change detection phase. In the change detection phase, one object always changed between pre- and post-change images and participants reported which object was changed. Results showed that VLTM of pre-change images enhanced the performance of change detection, while that of post-change images decreased accuracy. Prior exposure to both pre- and post-change images did not influence performance. These results indicate that pre-change information plays an important role in change detection, and that information in VLTM related to the current task does not always have a positive effect on performance. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Seasonal variation in hormonal responses of timber rattlesnakes (Crotalus horridus) to reproductive and environmental stressors.

    Science.gov (United States)

    Lutterschmidt, William I; Lutterschmidt, Deborah I; Mason, Robert T; Reinert, Howard K

    2009-08-01

    Data addressing adrenocortical modulation across taxonomic groups are limited, especially with regard to how female reproductive condition influences the sensitivity of the hypothalamus-pituitary-adrenal axis. We investigated seasonal and reproductive variation in basal and stress-induced hormone profiles in a population of free-ranging timber rattlesnakes (Crotalus horridus) in north-central Pennsylvania during spring (i.e., May), summer (i.e., July), and early fall (i.e., September). Baseline corticosterone concentrations varied seasonally and were significantly lower during the summer sampling period in July. We observed a significant negative relationship between baseline corticosterone and testosterone in male snakes, while baseline corticosterone and estradiol tended to be positively correlated in females. Treatment of snakes with 1 h of capture stress significantly increased corticosterone across all seasons. However, there was a significant interaction between corticosterone responses to capture stress and season, suggesting that adrenocortical function is modulated seasonally. Because elevated corticosterone may be associated with reproduction, we asked whether hormonal stress responses vary with female reproductive condition. Although sample sizes are low, reproductive snakes had significantly higher baseline and stress-induced corticosterone concentrations than non-reproductive or post-parturient females. Further, despite similar baseline corticosterone concentrations between non-reproductive and post-parturient rattlesnakes, post-parturient females responded to capture stress with a significantly higher increase in corticosterone. Collectively, these data suggest that the sensitivity of the hypothalamus-pituitary-adrenal axis varies both seasonally and with changing reproductive states.

  8. Animal perception of seasonal thresholds: changes in elephant movement in relation to rainfall patterns.

    Science.gov (United States)

    Birkett, Patricia J; Vanak, Abi T; Muggeo, Vito M R; Ferreira, Salamon M; Slotow, Rob

    2012-01-01

    The identification of temporal thresholds or shifts in animal movement informs ecologists of changes in an animal's behaviour, which contributes to an understanding of species' responses in different environments. In African savannas, rainfall, temperature and primary productivity influence the movements of large herbivores and drive changes at different scales. Here, we developed a novel approach to define seasonal shifts in movement behaviour by examining the movements of a highly mobile herbivore (elephant; Loxodonta africana), in relation to local and regional rainfall patterns. We used speed to determine movement changes of between 8 and 14 GPS-collared elephant cows, grouped into five spatial clusters, in Kruger National Park, South Africa. To detect broad-scale patterns of movement, we ran a three-year daily time-series model for each individual (2007-2009). Piecewise regression models provided the best fit for elephant movement, which exhibited a segmented, waveform pattern over time. Major breakpoints in speed occurred at the end of the dry and wet seasons of each year. During the dry season, female elephant are constrained by limited forage and thus the distances they cover are shorter and less variable. Despite the inter-annual variability of rainfall, speed breakpoints were strongly correlated with both local and regional rainfall breakpoints across all three years. Thus, at a multi-year scale, rainfall patterns significantly affect the movements of elephant. The variability of both speed and rainfall breakpoints across different years highlights the need for an objective definition of seasonal boundaries. By using objective criteria to determine behavioural shifts, we identified a biologically meaningful indicator of major changes in animal behaviour in different years. We recommend the use of such criteria, from an animal's perspective, for delineating seasons or other extrinsic shifts in ecological studies, rather than arbitrarily fixed definitions

  9. Animal perception of seasonal thresholds: changes in elephant movement in relation to rainfall patterns.

    Directory of Open Access Journals (Sweden)

    Patricia J Birkett

    Full Text Available BACKGROUND: The identification of temporal thresholds or shifts in animal movement informs ecologists of changes in an animal's behaviour, which contributes to an understanding of species' responses in different environments. In African savannas, rainfall, temperature and primary productivity influence the movements of large herbivores and drive changes at different scales. Here, we developed a novel approach to define seasonal shifts in movement behaviour by examining the movements of a highly mobile herbivore (elephant; Loxodonta africana, in relation to local and regional rainfall patterns. METHODOLOGY/PRINCIPAL FINDINGS: We used speed to determine movement changes of between 8 and 14 GPS-collared elephant cows, grouped into five spatial clusters, in Kruger National Park, South Africa. To detect broad-scale patterns of movement, we ran a three-year daily time-series model for each individual (2007-2009. Piecewise regression models provided the best fit for elephant movement, which exhibited a segmented, waveform pattern over time. Major breakpoints in speed occurred at the end of the dry and wet seasons of each year. During the dry season, female elephant are constrained by limited forage and thus the distances they cover are shorter and less variable. Despite the inter-annual variability of rainfall, speed breakpoints were strongly correlated with both local and regional rainfall breakpoints across all three years. Thus, at a multi-year scale, rainfall patterns significantly affect the movements of elephant. The variability of both speed and rainfall breakpoints across different years highlights the need for an objective definition of seasonal boundaries. CONCLUSIONS/SIGNIFICANCE: By using objective criteria to determine behavioural shifts, we identified a biologically meaningful indicator of major changes in animal behaviour in different years. We recommend the use of such criteria, from an animal's perspective, for delineating seasons or

  10. Seasonal and interplanetary magnetic field dependence of the field-aligned currents for both Northern and Southern Hemispheres

    Directory of Open Access Journals (Sweden)

    D. L. Green

    2009-04-01

    Full Text Available The configuration of the Earth's magnetosphere under various Interplanetary Magnetic Field (IMF and solar wind conditions alters the global distribution of Field-Aligned Currents (FACs at the high latitude ionospheres. We use magnetic field data obtained from the Iridium constellation to extend recent studies that infer the dependence of the global FAC configuration on IMF direction and magnitude, hemisphere and season. New results are a reduced IMF By influence on the FAC configuration for the winter hemisphere and a redistribution of FAC to the nightside for winter relative to the summer hemisphere. These effects are linked to the winter ionosphere conductance distribution being dominated by localised nightside enhancement associated with ionisation from energetic particle precipitation. A comparison of an estimated open-closed field line boundary (OCFLB with the Region 1 FAC locations shows reasonable agreement for summer FAC configurations. However, the OCFLB location is decoupled from the Region 1 FACs in winter, especially for IMF Bz>0.

  11. Changing water availability during the African maize-growing season, 1979–2010

    International Nuclear Information System (INIS)

    Estes, Lyndon D; Chaney, Nathaniel W; Herrera-Estrada, Julio; Sheffield, Justin; Caylor, Kelly K; Wood, Eric F

    2014-01-01

    Understanding how global change is impacting African agriculture requires a full physical accounting of water supply and demand, but accurate, gridded data on key drivers (e.g., humidity) are generally unavailable. We used a new bias-corrected meteorological dataset to analyze changes in precipitation (supply), potential evapotranspiration (E p , demand), and water availability (expressed as the ratio P/E p ) in 20 countries (focusing on their maize-growing regions and seasons), between 1979 and 2010, and the factors driving changes in E p . Maize-growing areas in Southern Africa, particularly South Africa, benefitted from increased water availability due in large part to demand declines driven primarily by declining net radiation, increasing vapor pressure, and falling temperatures (with no effect from changing windspeed), with smaller increases in supply. Sahelian zone countries in West Africa, as well as Ethiopia in East Africa, had strong increases in availability driven primarily by rainfall rebounding from the long-term Sahelian droughts, with little change or small reductions in demand. However, intra-seasonal supply variability generally increased in West and East Africa. Across all three regions, declining net radiation contributed downwards pressure on demand, generally over-riding upwards pressure caused by increasing temperatures, the regional effects of which were largest in East Africa. A small number of countries, mostly in or near East Africa (Tanzania and Malawi) experienced declines in water availability primarily due to decreased rainfall, but exacerbated by increasing demand. Much of the reduced water availability in East Africa occurred during the more sensitive middle part of the maize-growing season, suggesting negative consequences for maize production. (paper)

  12. Seasonality of change: Summer warming rates do not fully represent effects of climate change on lake temperatures

    Science.gov (United States)

    Winslow, Luke; Read, Jordan S.; Hansen, Gretchen J. A.; Rose, Kevin C.; Robertson, Dale M.

    2017-01-01

    Responses in lake temperatures to climate warming have primarily been characterized using seasonal metrics of surface-water temperatures such as summertime or stratified period average temperatures. However, climate warming may not affect water temperatures equally across seasons or depths. We analyzed a long-term dataset (1981–2015) of biweekly water temperature data in six temperate lakes in Wisconsin, U.S.A. to understand (1) variability in monthly rates of surface- and deep-water warming, (2) how those rates compared to summertime average trends, and (3) if monthly heterogeneity in water temperature trends can be predicted by heterogeneity in air temperature trends. Monthly surface-water temperature warming rates varied across the open-water season, ranging from 0.013 in August to 0.073°C yr−1 in September (standard deviation [SD]: 0.025°C yr−1). Deep-water trends during summer varied less among months (SD: 0.006°C yr−1), but varied broadly among lakes (–0.056°C yr−1 to 0.035°C yr−1, SD: 0.034°C yr−1). Trends in monthly surface-water temperatures were well correlated with air temperature trends, suggesting monthly air temperature trends, for which data exist at broad scales, may be a proxy for seasonal patterns in surface-water temperature trends during the open water season in lakes similar to those studied here. Seasonally variable warming has broad implications for how ecological processes respond to climate change, because phenological events such as fish spawning and phytoplankton succession respond to specific, seasonal temperature cues.

  13. Goal disturbance changes pre/post-renal transplantation are related to changes in distress.

    Science.gov (United States)

    de Vries, Alicia M; Schulz, Torben; Westerhuis, Ralf; Navis, Gerjan J; Niesing, Jan; Ranchor, Adelita V; Schroevers, Maya J

    2017-09-01

    Renal transplantation (RTx) is considered the treatment of choice for end-stage renal disease (ESRD) given its association with lower mortality, and improved overall quality of life and psychological functioning compared to dialysis. However, much less is known about which factors underlie these psychological improvements across RTx. Goal theory suggests that experienced disturbances in important goals are related to lower psychological functioning. This study aimed to (1) identify the most disturbed and most important goals for patients before RTx, (2) to examine changes in goal disturbance and goal importance pre/post-RTx, and (3) to examine whether changes in goal disturbance are associated with changes in psychological distress over time, and whether this relationship is mediated by changes in perceived control. In this longitudinal study, 220 patients completed questionnaires before and after RTx, including questionnaires to assess goals (GOALS questionnaire), psychological distress (GHQ-12), and perceived control (Mastery scale). End-stage renal disease affected both general and disease-specific goals. Approximately 30% of the patients indicated to experience high or very high disturbance before transplantation. Goal disturbance generally decreased significantly pre- to post-RTx, whereas goal importance did not change significantly pre- to post-RTx. No mediation effect of perceived control was found. Instead, both changes in goal disturbance and perceived control showed independent effects on changes in distress. Intervention strategies targeting attainable and realistic goal setting, and perceived control in RTx recipients who do not benefit optimally from RTx, might enhance psychological functioning in this population. Statement of contribution What is already known on this subject? Kidney transplantation improves patients' psychological functioning. Experienced disturbances in important life goals are related to lower psychological functioning in chronic

  14. Seasonal variation of the impact of a stressful procedure on open field behaviour and blood corticosterone in laboratory mice.

    Science.gov (United States)

    Meyer, L; Caston, J; Mensah-Nyagan, A G

    2006-02-28

    Behavioural and hormonal seasonal changes are well documented in various vertebrate species living in their natural environment but circannual variations that may occur in laboratory animals reared in standard conditions are poorly investigated. This study shows that, in laboratory mice, the effects of stress on behavioural inhibition, investigatory behaviour and blood concentration of corticosterone are seasonally dependent. No consistency was observed between the reactivity of biological structures controlling the hormonal response to stress and the behavioural activities investigated at every period of the year. During the spring time, stress, which elicited a decrease of investigatory behaviour (estimated by the walking time in an open field), increased behavioural inhibition (estimated by the percentage of walking in the central area of the open field) as well as the blood corticosterone concentration in laboratory mice. In autumn, stress had no significant effect on behaviour despite the great hormonal concentration increase. The results reveal that, at certain period of the year, a stressful procedure is unable to affect behavioural parameters in laboratory mice which were maintained in constant 12-h dark/12-h light cycle. The report constitutes a novel piece of information suggesting a potential role of the endogenous biological clock in the modulation of stress response in mammals.

  15. NEW SEASON NEW HOPES: OFF-SEASON OPTIMISM

    Directory of Open Access Journals (Sweden)

    Oguz Ersan

    2017-12-01

    Full Text Available While literature on the relation between on-field sports performance and stock returns is ample, there is very limited evidence on off-season stage. Constituting around 3 months, off-seasons do not only occupy a significant part of the year but also represent totally different characteristics than on-seasons. They lack the periodic, unambiguous news events in on-seasons (match results, instead they are associated with highly uncertain transfer news and rumors. We show that this distinction has several impacts on the stock market performances of soccer clubs. Most notably, off-seasons generate substantially higher (excess returns. After controlling for other variables, the estimated effect of off-season periods is as high as 38.75%, annually. In line with several seminal studies, we link this fact to increased optimism and betting behavior through uncertain periods; and periods prior to the start of a new calendar (in our case, new season. For all of the examined 7 clubs (3 from Italy and 4 from Turkey, mean excess returns over the market are positive (negative in off-seasons (on-seasons. On-seasons are associated with increased trading activity due to more frequent news. Stocks of Italian clubs are evidently more volatile through off-seasons while volatility results for the stocks of Turkish clubs are not consistent.

  16. Changes in eucalypt litter quality during the first three months of field decomposition in a Congolese plantation

    OpenAIRE

    Ngao, Jérôme; Bernhard Reversat, France; Loumeto, J. J.

    2009-01-01

    In fast-growing tree plantations, decomposition of leaf litter is considered as a key process of soil fertility. A three-month field experiment, spanning both rainy and dry seasons, was conducted to determine how changes in litter decomposition affect the main parameters of litter quality-namely, the concentrations of phenolic and non-phenolic carbon (C) compounds, nitrogen (N), and fibres, and the litter C mineralization rate. This Study was conducted to test (1) if these changes vary accord...

  17. Seasonal changes of vitamin A levels of serum in Khozestan Arab horses

    Directory of Open Access Journals (Sweden)

    alireza ghadrdanmashhadi

    2013-08-01

    Full Text Available Vitamin A is one of the fat-soluble vitamins. Because of its particular role in different tissues and organs, various clinical signs are seen in deficiency conditions. In addition, sometimes marginal deficiency is present without obvious clinical signs but performance defects, such as infertility is seen. In present study seasonal changes of serum vitamin A in 22 Arab horses was investigated in Ahvaz. A simple and cheap method (spectrophotometrye was used for measuring vitamin A. The results were analyzed statistically by one- way analysis of variance (ANOVA. The results indicated that mean vitamin A values (20.37±1/21mg/dl were within normal range. The values of vitamin A in different seasons and two sexes were normal, too. Serum vitamin A value in spring was significantly higher than other seasons.

  18. Season-induced changes in bovine sperm motility following a freeze-thaw procedure.

    Science.gov (United States)

    Orgal, Shlomo; Zeron, Yoel; Elior, Nili; Biran, David; Friedman, Eran; Druker, Shaked; Roth, Zvi

    2012-01-01

    Decreased conception rate of dairy cows in the summer is mainly associated with the deleterious effects of environmental thermal stress on the female reproductive tract. Here, we suggest that decreased reproductive performance might be partially due to inferior-quality semen. Semen from five representative bulls was collected in summer (August to September) and winter (December to January) and evaluated with a computerized sperm-quality analyzer for bulls (SQA-Vb). No seasonal effect was found in fresh ejaculate, but sperm examined post-thawing showed lower velocity, motility and progressive motility (Pconception rate of dairy cows in summer.

  19. Postkolonialismi pealetung post -sovetoloogias: kas paradigmamuutuse künnisel? The Rise of Post-Colonialism in Post-Soviet Studies: Witnessing the Paradigm Change

    Directory of Open Access Journals (Sweden)

    Epp Annus

    2012-04-01

    Full Text Available This article analyses the current state of research in studies of Soviet colonialism and considers inner tensions within this emerging field. By now, dozens of monographs and hundreds of articles touch upon the various aspects of Soviet postcolonialism, yet the field is fragmented and full of inner contradictions and unanswered questions: What is the relationship of research in Soviet colonialism to postcolonial studies in general? What is its relationship to traditional Sovietology? Areas of tension are found through historical and geographical perspectives, in the Russian neglect of its own Soviet imperialism, and in the long-distance scholarship dominant in the area. This paper argues that what we are witnessing now is the pains of a paradigm change, further aggravated by special complexities within the field. The article offers a historical overview of the development of studies of Soviet colonialism and shows that a decisive turn took place in the first decade of the twenty-first century. In 1990s, postcolonial perspectives were more widely employed in analyses of Tsarist-era Russian history. In the 2000s, several important monographs about the Soviet Union were published, yet, interestingly, their main focus was the inter-war period, before the Baltic states were annexed to the Soviet Union. Thus, for research into Baltic Soviet history, these collections and monographs can only provide background information. As for the post-WWII era, most important work from the perspective of Baltic studies – that is, general arguments about the developments in Soviet Union – remain on the level of single articles, the best known of these being David Chioni Moore’s „Is the Post- in Postcolonial the Post- in Post-Soviet? Toward a Global Postcolonial Critique“ (2001. The article makes a distinction between the general term „empire-studies“ and the more restricted notion of „studies of colonialism“; it further distuinguishes post colonial

  20. De-coupling seasonal changes in water content and dry matter to predict live conifer foliar moisture content

    Science.gov (United States)

    W. Matt Jolly; Ann M. Hadlow; Kathleen Huguet

    2014-01-01

    Live foliar moisture content (LFMC) significantly influences wildland fire behaviour. However, characterising variations in LFMC is difficult because both foliar mass and dry mass can change throughout the season. Here we quantify the seasonal changes in both plant water status and dry matter partitioning. We collected new and old foliar samples from Pinus contorta for...

  1. Seasonal changes in climatic parameters and their relationship with the incidence of pneumococcal bacteraemia in Denmark

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Lundbye-Christensen, Søren; Thomsen, R.W.

    2008-01-01

    The seasonal variation in the incidence of invasive pneumococcal disease is well recognized, but little is known about its relationship with actual changes in climatic parameters. In this 8-year longitudinal population-based study in Denmark, a harmonic sinusoidal regression model was used...... to examine whether preceding changes in climatic parameters corresponded with subsequent variations in the incidence of pneumococcal bacteraemia, independently of seasonal variation. The study shows that changes in temperature can be used to closely predict peaks in the incidence of pneumococcal bacteraemia...

  2. Penicillin-mediated changes in viable benthic diatom assemblages – insights about the relevance of bacteria across spatial and seasonal scales.

    Digital Repository Service at National Institute of Oceanography (India)

    DeCosta, P.M.; Anil, A.C.

    environment) and seasonal (post-monsoon, pre-monsoon, monsoon) scales. Penicillin treatment resulted in bacterial suppression and a reduction in diatoms at the intertidal and mangrove sites having stable pennate-dominated assemblages. Diatom response...

  3. Seasonal changes in water content and turnover in cattle, sheep and goats grazing under humid tropical conditions in Ghana

    International Nuclear Information System (INIS)

    Aggrey, E.K.

    1982-01-01

    The effect of seasonal changes on water content and water turnover of cattle, sheep and goats at pasture under humid tropical conditions was studied. Measurement of total body water and water turnover was based on the tritium dilution technique. Total body water was significantly higher in all three species of animal during the dry season, while water turnover was significantly lower in the dry season than in the wet season. In all seasons water turnover was highest in cattle, followed by sheep and then goat. Changes in body weight, body water, body solids and water turnover were associated with seasonal variations in nutrition. The indication was that the goat would be a more suitable animal for production under dry conditions than cattle and sheep. (author)

  4. Hydrological changes impacts on annual runoff distribution in seasonally dry basins

    Science.gov (United States)

    Viola, F.; Caracciolo, D.; Feng, X.

    2017-12-01

    Runoff is expected to be modified in the next future by climate change as well as by land use change. Given its importance for water supply and ecosystem functioning, it is therefore imperative to develop adaptation strategies and new policies for regional water resources management and planning. To do so, the identification and attribution of natural flow regime shifts as a result of climate and land use changes are of crucial importance. In this context, the Budyko's curve has begun to be widely adopted to separate the contributions of climate and land use changes to the variation of runoff over long-term periods by using the multi-year averages of hydrological variables. In this study, a framework based on Fu's equation is proposed and applied to separate the impacts of climate and land use changes on the future annual runoff distribution in seasonally dry basins, such as those in Mediterranean climates. In particular, this framework improves a recently developed method to obtain annual runoff probability density function (pdf) in seasonally dry basins from annual rainfall and potential evapotranspiration statistics, and from knowledge of the Fu's equation parameter ω. The effect of climate change has been taken into account through the variation of the first order statistics of annual rainfall and potential evapotranspiration, consistent with general circulation models' outputs, while the Fu's equation parameter ω has been changed to represent land use change. The effects of the two factors of change (i.e., climate and land use) on the annual runoff pdf have been first independently and then jointly analyzed, by reconstructing the annual runoff pdfs for the current period and, based on likely scenarios, within the next 100 years. The results show that, for large basins, climate change is the dominant driver of the decline in annual runoff, while land use change is a secondary but important factor.

  5. Seasonal changes and effect of harvest on glucosinolates in Isatis leaves.

    Science.gov (United States)

    Mohn, Tobias; Suter, Kathrin; Hamburger, Matthias

    2008-04-01

    The seasonal fluctuation of glucosinolates in five defined Isatis tinctoria and one Isatis indigotica accessions (first year, rosette stage), grown on field plots under identical conditions, was investigated. Analysis of the intact glucosinolates was carried out with shock frozen, freeze dried leaf samples using a recently developed and validated PLE (pressurized liquid extraction) protocol and ion-pair HPLC coupled with ESI-MS in the negative mode. When comparing the two Isatis species, significant qualitative and quantitative differences in the glucosinolate patterns were observed. Differences among the various Isatis tinctoria accessions were much smaller. We studied the effects of repeated harvesting during the growth season on glucosinolate concentrations and found that repeated harvest did not have a major effect on glucosinolate concentrations of newly grown leaves. Glucosinolates could not be detected in woad leaves submitted to conventional drying.

  6. Including Media in Field Research and Becoming Part of the Science Media

    Science.gov (United States)

    Pelto, M. S.

    2015-12-01

    There are two primary strategies that I have pursued over the last decade to engage the media, policy makers, and public; after two decades of typical scientific publication methods. An effective method to engage the media with our ongoing 32 year glacier field research program has been to invite media members to join us in the field. From climate videographers to traditional reporters we have had a member of the media with us in nine of the last ten field seasons; two in 2015. The resulting stories have led to several awards for the journalists and an ongoing relationship with our research program. The second part of this science research communication strategy is to have readily available material on specific topics for the media to utilize; this requires social media outreach. The primary outlet media find is the AGU Blog: From a Glacier's Perspective. This blog pubishes two articles a week on a specific glacier's response to climate change. The blog yields on average a media contact on every fourth blog post in 2015. The contacts revolve around specific local glacier information published on the blog. The goal of each blog post is to tell a story about how each glacier is impacted by climate change.

  7. Patterns of Change in Depression Post Stroke

    Science.gov (United States)

    Ostir, Glenn V.; Berges, Ivonne-M.; Ottenbacher, Allison; Ottenbacher, Kenneth J.

    2011-01-01

    Background Little information is available on depressive symptom change in persons with stroke. Objectives Provide estimates of change in depressive symptoms and determine how depressive symptom change influences recovery of functional status. Design Prospective cohort study. Setting Eleven in-patient medical rehabilitation facilities located across the U.S. Participants 544 persons with a first-time stroke. Measurements General linear regression model estimates assessed associations between depressive symptom change and functional status 3 and 12 months post discharge. Results The majority of persons with stroke were aged 75 and older, white, female and married. The most prevalent stroke type was ischemic. Non-depressed patients at discharge who reported fewer symptoms 12-months later had an adjusted functional status score of 108.2. This compared to adjusted functional status scores of 104.6 for those non-depressed at discharge with increasing symptoms over the 12-month follow-up, 100.3 for those depressed at discharge with fewer symptoms over the 12-month follow-up, and 88.0 for those depressed at discharge with more symptoms over the 12-month follow-up. Conclusion Tracking depressive symptom change in hospital and post discharge is clinically relevant and an important component of patient care and recovery of functional status. PMID:21275930

  8. Nuclear power and post-2012 energy and climate change policies

    International Nuclear Information System (INIS)

    Weisser, Daniel; Howells, Mark; Rogner, Hans-Holger

    2008-01-01

    At present there is no binding agreement (at a global level) to address the risk of anthropogenic climate change after 2012. Disagreements abound with respect to a post-2012 climate change agreement, on issues such as economic development, policy criteria, environmental effectiveness, cost-effectiveness, equity, dynamic flexibility, complementarity, enforceability and so on. One such disagreement is whether or not nuclear power should play a role in a post-2012 climate change agreement. This qualitative analysis explores the conditions under which nuclear power could contribute to addressing climate change in post-2012 architectures. It reveals that - given the right framework conditions - some architectures, like 'cap and trade' regimes or 'policies and measures' can improve the competitiveness of nuclear power plants, while others are unlikely to provide incentives for nuclear energy development in the short to medium term, such as adaptation and technology cooperation. Overall, the study concludes that post-2012 climate change policy should aim at providing policy flexibility without compromising technology flexibility. For example, the provision of long-term commitment periods has the potential to enable better investments in existing low-carbon technologies but stifle the policy flexibility that political decision makers are often keen to retain so that they can respond more quickly to new scientific evidence or advances in clean technology development

  9. Northern Great Basin Seasonal Lakes: Vulnerability to Climate Change.

    Science.gov (United States)

    Russell, M.; Eitel, J.

    2017-12-01

    Seasonal alkaline lakes in southeast Oregon, northeast California, and northwest Nevada serve as important habitat for migrating birds utilizing the Pacific Flyway, as well as local plant and animal communities. Despite their ecological importance, and anecdotal suggestions that these lakes are becoming less reliable, little is known about the vulnerability of these lakes to climate change. Our research seeks to understand the vulnerability of Northern Great Basin seasonal lakes to climate change. For this, we will be using historical information from the European Space Agency's Global Surface Water Explorer and the University of Idaho's gridMET climate product, to build a model that allows estimating surface water extent and timing based on climate variables. We will then utilize downscaled future climate projections to model surface water extent and timing in the coming decades. In addition, an unmanned aerial system (UAS) will be utilized at a subset of dried basins to obtain precise 3D bathymetry and calculate water volume hypsographs, a critical factor in understanding the likelihood of water persistence and biogeochemical habitat suitability. These results will be incorporated into decision support tools that land managers can utilize in water conservation, wildlife management, and climate mitigation actions. Future research may pair these forecasts with animal movement data to examine fragmentation of migratory corridors and species-specific impacts.

  10. The Impact of a Kinesthetic Approach to Teaching Earth's Seasons

    Science.gov (United States)

    Slater, Stephanie; Morrow, C. A.

    2010-01-01

    The AAAS Benchmarks and NRC National Science Education Standards clearly prescribe that all American middle school students should understand that Earth's seasons are caused by variations in the amount of sunlight that hits Earth's surface due to tilt. An explanation for the cause of the seasons that is consistent with a scientifically accurate viewpoint would involve how the amount of sunlight reaching Earth's surface at different latitudes and is directly related to the planet's tilt. However, the most common alternative explanation given is the changing distance between the Sun and Earth. Previous research, as well as common experience, indicates that conventional instructional approaches on the concept of seasons are rarely sufficient in achieving scientifically accurate or durable conceptual change. Given the highly spatial nature of the concept, and the highly socially nature of human beings, some curriculum developers have turned to kinesthetic instructional approaches as a means to develop students' spatial reasoning and problem solving skills while confronting misconceptions and allowing students to socially construct scientifically accurate models of the seasons. We report results from a quantitative study on the impact on understanding of ninth grade students using kinesthetic approach to instruction for the traditionally challenging topic of Earth's seasons. The guiding research question was: To what extent does the kinesthetic astronomy instructional approach assist students in correcting misconceptions about the cause of the seasons? Using a single-group, multiple measures quasi-experimental study design, data was collected pre- and post-instruction using written, student-supplied-response assessments. Additionally, a third assessment was conducted 8 weeks after instruction in an attempt to measure durability. The results showed that statistically significant conceptual change occurred across three subtopics supporting seasons and were stable over 8

  11. Effects of payment changes on trends in post-acute care.

    Science.gov (United States)

    Buntin, Melinda Beeuwkes; Colla, Carrie Hoverman; Escarce, José J

    2009-08-01

    To test how the implementation of new Medicare post-acute payment systems affected the use of inpatient rehabilitation facilities (IRFs), skilled nursing facilities (SNFs), and home health agencies. Medicare acute hospital, IRF, and SNF claims; provider of services file; enrollment file; and Area Resource File data. We used multinomial logit models to measure realized access to post-acute care and to predict how access to alternative sites of care changed in response to prospective payment systems. A file was constructed linking data for elderly Medicare patients discharged from acute care facilities between 1996 and 2003 with a diagnosis of hip fracture, stroke, or lower extremity joint replacement. Although the effects of the payment systems on the use of post-acute care varied, most reduced the use of the site of care they directly affected and boosted the use of alternative sites of care. Payment system changes do not appear to have differentially affected the severely ill. Payment system incentives play a significant role in determining where Medicare beneficiaries receive their post-acute care. Changing these incentives results in shifting of patients between post-acute sites.

  12. Post-1980 shifts in the sensitivity of boreal tree growth to North Atlantic Ocean dynamics and seasonal climate. Tree growth responses to North Atlantic Ocean dynamics

    Science.gov (United States)

    Ols, Clémentine; Trouet, Valerie; Girardin, Martin P.; Hofgaard, Annika; Bergeron, Yves; Drobyshev, Igor

    2018-06-01

    The mid-20th century changes in North Atlantic Ocean dynamics, e.g. slow-down of the Atlantic meridional overturning thermohaline circulation (AMOC), have been considered as early signs of tipping points in the Earth climate system. We hypothesized that these changes have significantly altered boreal forest growth dynamics in northeastern North America (NA) and northern Europe (NE), two areas geographically adjacent to the North Atlantic Ocean. To test our hypothesis, we investigated tree growth responses to seasonal large-scale oceanic and atmospheric indices (the AMOC, North Atlantic Oscillation (NAO), and Arctic Oscillation (AO)) and climate (temperature and precipitation) from 1950 onwards, both at the regional and local levels. We developed a network of 6876 black spruce (NA) and 14437 Norway spruce (NE) tree-ring width series, extracted from forest inventory databases. Analyses revealed post-1980 shifts from insignificant to significant tree growth responses to summer oceanic and atmospheric dynamics both in NA (negative responses to NAO and AO indices) and NE (positive response to NAO and AMOC indices). The strength and sign of these responses varied, however, through space with stronger responses in western and central boreal Quebec and in central and northern boreal Sweden, and across scales with stronger responses at the regional level than at the local level. Emerging post-1980 associations with North Atlantic Ocean dynamics synchronized with stronger tree growth responses to local seasonal climate, particularly to winter temperatures. Our results suggest that ongoing and future anomalies in oceanic and atmospheric dynamics may impact forest growth and carbon sequestration to a greater extent than previously thought. Cross-scale differences in responses to North Atlantic Ocean dynamics highlight complex interplays in the effects of local climate and ocean-atmosphere dynamics on tree growth processes and advocate for the use of different spatial scales in

  13. Changes of Phosphate Solubilizing Bacteria Population on Paddy Field with Intensive Farming became Sustainable Organic Farming System

    Directory of Open Access Journals (Sweden)

    Dermiyati

    2009-05-01

    Full Text Available The research aimed to study the change of population of phosphate solubilizing microorganisms according to the application time of bokashi which were applied continously on organic paddy rice fields since years of 2000 up to 2006. The research was conducted in a Randomized Completely Block Design in four replicates. The treatments were without bokashi (control; with intensively application of NPK fertilizers, bokashi application for 3 planting seasons (12 t ha-1, bokashi application for 4 planting seasons (16 t ha-1, bokashi application for 7 planting seasons (28 t ha-1, and bokashi application for 9 planting seasons (36 t ha-1. The results showed that the population of phosphate solubilizing microorganisms were not affected by continously applied of bokashi and did not have correlations to organic carbon, total nitrogen, ratio C/N, soil pH, and soil water content. However, the phosphate solubilizing microorganisms had played a role in the availability of the soil available-P which were shown by increasing of paddy yields year by year, although the contribution of soil phosphorus from bokashi is a relatively low. Yet, the bokashi application on the organic paddy fields did not increase the soil availble-P because most of the P which was absorbed by the plants coming from residual P fertilizers either from bokashi or SP-36 which were intensevely given before.

  14. Seasonal Scale Convective-Stratiform Pricipitation Variabilities at Tropics

    Science.gov (United States)

    S, Sreekanth T.

    begin{center} Large Seasonal Scale Convective-Stratiform Pricipitation Variabilities at Tropics Sreekanth T S*, Suby Symon*, G. Mohan Kumar (1) and V Sasi Kumar (2) *Centre for Earth Science Studies, Akkulam, Thiruvananthapuram (1) D-330, Swathi Nagar, West Fort, Thiruvananthapuram 695023 (2) 32. NCC Nagar Peroorkada, Thiruvananthapuram ABSTRACT This study investigates the variabilities of convective and stratiform rainfall from 2011 to 2013 at a tropical coastal station in three seasons viz Pre-Monsoon (March-May), Monsoon (June-September) and Post-Monsoon (October-December). Understanding the climatological variability of these two dominant forms of precipitation and their implications in the total rainfall were the main objectives of this investigation. Variabilities in the frequency & duration of events, rain rate & total number of rain drops distribution in different events and the accumulated amount of rain water were analysed. Based on the ground & radar observations from optical & impact disdrometers, Micro Rain Radar and Atmospheric Electric Field Mill, precipitation events were classified into convective and stratiform in three seasons. Classification was done by the method followed by Testud et al (2001) and as an additional information electrical behaviour of clouds from Atmospheric Electric Field Mill is also used. Events which could not be included in both types were termed as 'mixed precipitation' and were included separately. Diurnal variability of the total rainfall in each seasons were also examined. For both convective and stratiform rainfall there exist distinct day-night differences. During nocturnal hours convective rain draged more attention. In all seasons almost 70% of rain duration and 60% of rain events of convective origin were confined to nocturnal hours. But stratiform rain was not affected by diurnal variations greatly because night time occurrences of stratiform duration and events were less than 50%. Also in Monsoon above 35% of

  15. Normal Variability of Weekly Musculoskeletal Screening Scores and the Influence of Training Load across an Australian Football League Season.

    Science.gov (United States)

    Esmaeili, Alireza; Stewart, Andrew M; Hopkins, William G; Elias, George P; Lazarus, Brendan H; Rowell, Amber E; Aughey, Robert J

    2018-01-01

    Aim: The sit and reach test (S&R), dorsiflexion lunge test (DLT), and adductor squeeze test (AST) are commonly used in weekly musculoskeletal screening for athlete monitoring and injury prevention purposes. The aim of this study was to determine the normal week to week variability of the test scores, individual differences in variability, and the effects of training load on the scores. Methods: Forty-four elite Australian rules footballers from one club completed the weekly screening tests on day 2 or 3 post-main training (pre-season) or post-match (in-season) over a 10 month season. Ratings of perceived exertion and session duration for all training sessions were used to derive various measures of training load via both simple summations and exponentially weighted moving averages. Data were analyzed via linear and quadratic mixed modeling and interpreted using magnitude-based inference. Results: Substantial small to moderate variability was found for the tests at both season phases; for example over the in-season, the normal variability ±90% confidence limits were as follows: S&R ±1.01 cm, ±0.12; DLT ±0.48 cm, ±0.06; AST ±7.4%, ±0.6%. Small individual differences in variability existed for the S&R and AST (factor standard deviations between 1.31 and 1.66). All measures of training load had trivial effects on the screening scores. Conclusion: A change in a test score larger than the normal variability is required to be considered a true change. Athlete monitoring and flagging systems need to account for the individual differences in variability. The tests are not sensitive to internal training load when conducted 2 or 3 days post-training or post-match, and the scores should be interpreted cautiously when used as measures of recovery.

  16. Mood Sensitivity to Seasonal Changes in African College Students Living in the Greater Washington D.C. Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Alvaro Guzman

    2007-01-01

    Full Text Available The purpose of this study was to estimate the degree of seasonality and prevalence of winter- and summer-type seasonal affective disorder (SAD in African immigrant college students in comparison with African American peers. A convenience sample of 246 African immigrants and 599 African Americans studying in Washington, D.C. completed the Seasonal Pattern Assessment Questionnaire (SPAQ, which was used to calculate a global seasonality score (GSS and to estimate the prevalence of winter- and summer-type SAD. Degree of seasonality was related to a complex interaction between having general awareness of SAD, ethnicity, and gender. A greater percentage of African students reported experiencing a problem with seasonal changes relative to African American students, and had summer SAD, but the groups did not differ on GSS and winter SAD. African students reported more difficulties with seasonal changes than their African American peers, which could represent a manifestation of incomplete acclimatization to a higher latitude and temperate climate. As Africans also had a greater rate of summer SAD, this argues against acclimatization to heat.

  17. Preservation of potassium balance is strongly associated with insect cold tolerance in the field: a seasonal study of Drosophila subobscura.

    Science.gov (United States)

    MacMillan, Heath A; Schou, Mads F; Kristensen, Torsten N; Overgaard, Johannes

    2016-05-01

    There is interest in pinpointing genes and physiological mechanisms explaining intra- and interspecific variations in cold tolerance, because thermal tolerance phenotypes strongly impact the distribution and abundance of wild animals. Laboratory studies have highlighted that the capacity to preserve water and ion homeostasis is linked to low temperature survival in insects. It remains unknown, however, whether adaptive seasonal acclimatization in free-ranging insects is governed by the same physiological mechanisms. Here, we test whether cold tolerance in field-caught Drosophila subobscura is high in early spring and lower during summer and whether this transition is associated with seasonal changes in the capacity of flies to preserve water and ion balance during cold stress. Indeed, flies caught during summer were less cold tolerant, and exposure of these flies to sub-zero temperatures caused a loss of haemolymph water and increased the concentration of K(+) in the haemolymph (as in laboratory-reared insects). This pattern of ion and water balance disruption was not observed in more cold-tolerant flies caught in early spring. Thus, we here provide a field verification of hypotheses based on laboratory studies and conclude that the ability to maintain ion homeostasis is important for the ability of free-ranging insects to cope with chilling. © 2016 The Author(s).

  18. Seasonal changes in testosterone and corticosterone levels in four social classes of a desert dwelling sociable rodent.

    Science.gov (United States)

    Schradin, Carsten

    2008-04-01

    Animals have to adjust their physiology to seasonal changes, in response to variation in food availability, social tactics and reproduction. I compared basal corticosterone and testosterone levels in free ranging striped mouse from a desert habitat, comparing between the sexes, breeding and philopatric non-breeding individuals, and between the breeding and the non-breeding season. I expected differences between breeders and non-breeders and between seasons with high and low food availability. Basal serum corticosterone was measured from 132 different individuals and serum testosterone from 176 different individuals of free living striped mice. Corticosterone and testosterone levels were independent of age, body weight and not influenced by carrying a transmitter. The levels of corticosterone and testosterone declined by approximately 50% from the breeding to the non-breeding season in breeding females as well as non-breeding males and females. In contrast, breeding males showed much lower corticosterone levels during the breeding season than all other classes, and were the only class that showed an increase of corticosterone from the breeding to the non-breeding season. As a result, breeding males had similar corticosterone levels as other social classes during the non-breeding season. During the breeding season, breeding males had much higher testosterone levels than other classes, which decreased significantly from the breeding to the non-breeding season. My results support the prediction that corticosterone decreases during periods of low food abundance. Variation in the pattern of hormonal secretion in striped mice might assist them to cope with seasonal changes in energy demand in a desert habitat.

  19. Sphagnum-dwelling testate amoebae in subarctic bogs are more sensitive to soil warming in the growing season than in winter: the results of eight-year field climate manipulations.

    Science.gov (United States)

    Tsyganov, Andrey N; Aerts, Rien; Nijs, Ivan; Cornelissen, Johannes H C; Beyens, Louis

    2012-05-01

    Sphagnum-dwelling testate amoebae are widely used in paleoclimate reconstructions as a proxy for climate-induced changes in bogs. However, the sensitivity of proxies to seasonal climate components is an important issue when interpreting proxy records. Here, we studied the effects of summer warming, winter snow addition solely and winter snow addition together with spring warming on testate amoeba assemblages after eight years of experimental field climate manipulations. All manipulations were accomplished using open top chambers in a dry blanket bog located in the sub-Arctic (Abisko, Sweden). We estimated sensitivity of abundance, diversity and assemblage structure of living and empty shell assemblages of testate amoebae in the living and decaying layers of Sphagnum. Our results show that, in a sub-arctic climate, testate amoebae are more sensitive to climate changes in the growing season than in winter. Summer warming reduced species richness and shifted assemblage composition towards predominance of xerophilous species for the living and empty shell assemblages in both layers. The higher soil temperatures during the growing season also decreased abundance of empty shells in both layers hinting at a possible increase in their decomposition rates. Thus, although possible effects of climate changes on preservation of empty shells should always be taken into account, species diversity and structure of testate amoeba assemblages in dry subarctic bogs are sensitive proxies for climatic changes during the growing season. Copyright © 2011 Elsevier GmbH. All rights reserved.

  20. The costs of seasonality and expansion in Ireland’s milk production and processing

    Directory of Open Access Journals (Sweden)

    Heinschink K.

    2016-12-01

    Full Text Available Ireland’s milk production sector relies on grass-based spring-calving systems, which facilitates cost advantages in milk production but entails a high degree of supply seasonality. Among other implications, this supply seasonality involves extra costs in the processing sector including elevated plant capacities and varying levels of resource utilisation throughout the year. If both the national raw milk production increased substantially (e.g. post-milk quota and a high degree of seasonality persisted, extra processing capacities would be required to cope with peak supplies. Alternatively, existing capacities could be used more efficiently by distributing the milk volume more evenly during the year. In this analysis, an optimisation model was applied to analyse the costs and economies arising to an average Irish milk-processing business due to changes to the monthly distribution of milk deliveries and/or the total annual milk pool. Of the situations examined, changing from a seasonal supply prior to expansion to a smoother pattern combined with an increased milk pool emerged as the most beneficial option to the processor because both the processor’s gross surplus and the marginal producer milk price increased. In practice, it may however be the case that the extra costs arising to the producer from smoothing the milk intake distribution exceed the processor’s benefit. The interlinkages between the stages of the dairy supply chain mean that nationally, the seasonality trade-offs are complex and equivocal. Moreover, the prospective financial implications of such strategies will be dependent on the evolving and uncertain nature of international dairy markets in the post-quota environment.

  1. Seasonal Variations in Color Preference.

    Science.gov (United States)

    Schloss, Karen B; Nelson, Rolf; Parker, Laura; Heck, Isobel A; Palmer, Stephen E

    2017-08-01

    We investigated how color preferences vary according to season and whether those changes could be explained by the ecological valence theory (EVT). To do so, we assessed the same participants' preferences for the same colors during fall, winter, spring, and summer in the northeastern United States, where there are large seasonal changes in environmental colors. Seasonal differences were most pronounced between fall and the other three seasons. Participants liked fall-associated dark-warm colors-for example, dark-red, dark-orange (brown), dark-yellow (olive), and dark-chartreuse-more during fall than other seasons. The EVT could explain these changes with a modified version of Palmer and Schloss' (2010) weighted affective valence estimate (WAVE) procedure that added an activation term to the WAVE equation. The results indicate that color preferences change according to season, as color-associated objects become more/less activated in the observer. These seasonal changes in color preferences could not be characterized by overall shifts in weights along cone-contrast axes. Copyright © 2016 Cognitive Science Society, Inc.

  2. Hemato-biochemical responses to packing in donkeys administered ascorbic acid during the harmattan season.

    Science.gov (United States)

    Olaifa, Folashade; Ayo, Joseph Olusegun; Ambali, Suleiman Folorunsho; Rekwot, Peter Ibrahim

    2015-02-01

    Experiments were performed to investigate the effect of ascorbic acid (AA) in reducing hemato-biochemical changes in pack donkeys during the cold-dry (harmattan) season. Six experimental donkeys administered orally AA (200 mg/kg) and six control donkeys not administered ascorbic acid were subjected to packing. Blood samples were collected from all donkeys for hematological and biochemical analyses. In the control donkeys, packed cell volume (PCV), erythrocyte count and hemoglobin concentration (Hb) decreased significantly (Pdonkeys, there was no significant difference between the pre- and post-packing values of PCV, erythrocyte count and Hb. In the control donkeys, the neutrophil and neutrophil:lymphocyte ratio increased significantly (Pdonkeys, the pre- and post-packing values were not significantly different. The eosinophil count increased significantly (Pdonkeys post packing. In conclusion, packing exerted significant adverse effects on the hematological parameters ameliorated by AA administration. AA may modulate neutrophilia and induce a considerable alteration of erythroid markers in donkeys subjected to packing during the harmattan season.

  3. Seasonal variation of carbon dioxide and methane exchange between rice paddy fields and atmosphere in Japan

    Science.gov (United States)

    Kokubo, R.

    2017-12-01

    Rice paddy fields spread throughout Asia and play an important role in terms of regulating greenhouse gases on the ground. Rice paddies have the potential to either increase or decrease the net balance of greenhouse gases in the atmosphere. In the rice growth period, rice paddy fields are sources of CH4, whereas they generally act as a sink of CO2. However, the behavior of greenhouse gases during fallow periods has not been well understood. A field experiment was conducted at a rice paddy field in Fuchu, central Japan in 2014. We evaluated CO2 and CH4 fluxes in the rice paddy field using the eddy covariance method. Except for 20 days after transplanting (DAT), temporal CO2 fluxes showed negative values during a rice growth period whereas they showed positive values throughout a fallow period. The positive CO2 fluxes at 2 emissions by respiration of rice plants and soil microorganisms than CO2 uptake by photosynthesis of rice plants. In the middle of the growing season at around DAT=50, CO2 emission became dominant again because flooded water was temporarily drained in the rice paddy field. Seasonal CH4 fluxes during a growth period were regulated by water management and plant growth stages. During a fallow period, however, the field was kept a non-flooded condition that resulted in an aerobic soil condition and thus very low CH4 emission.

  4. Seasonal changes in quality of wastewater from fruit and vegetable industry

    Science.gov (United States)

    Puchlik, Monika; Ignatowicz, Katarzyna

    2017-11-01

    The paper aimed at evaluating the seasonal changes in quality of wastewater from facilities producing fruit and vegetable juices, processed and frozen products, and vegetable concentrates. The study revealed that wastewater from fruit and vegetable industry contain large amounts of organic substances expressed as BOD5 (minimum - 500 mgO2/dm3, maximum - 6 100 mgO2/dm3) and COD (minimum - 806 mg O2/dm3, maximum - 7 732 mg O2/dm3), while is deficient in nitrogen and phosphorus. Considerable seasonal oscillations in sewage load disposed by industry to sewerage, were observed. An increase of 50%-60% wastewater concentrations was found between June and October in 2013-2016 as compared to the remaining months.

  5. Post-fire regeneration in seasonally dry tropical forest fragments in southeastern Brazil.

    Science.gov (United States)

    Costa, Mayke B; Menezes, Luis Fernando T DE; Nascimento, Marcelo T

    2017-01-01

    Seasonally dry tropical forest is one of the highly threatened biome. However, studies on the effect of fire on these tree communities are still scarce. In this context, a floristic and structural survey in three forest areas in the southeast of Brazil that were affected by fire between 14 and 25 years ago was performed with the objective of evaluating post-fire regeneration. In each site, five systematically placed plots (25 m x 25 m each) were established. The more recently burnt site had significantly lower values of richness and diversity than the other two sites. However, the sites did not differ in density and basal area. Annona dolabripetala, Astronium concinnum, Joannesia princeps and Polyandrococos caudescens were within the 10 most important species for the three sites. Comparing these data with adjacent mature forests, the results indicated differences both in structural and floristic aspects, suggesting that the time after fire was not sufficient for recuperation of these areas. The recovery process indicate at least 190 years for areas return to basal area values close to those observed in mature forests nearby.

  6. Seasonal variations of the high-latitude geomagnetic field intensity in the northern hemisphere

    International Nuclear Information System (INIS)

    Rivin, Yu.R.; Chkhaidze, Z.Sh.

    1994-01-01

    Seasonal variation of the geomagnetic field three components is investigated using the data of the USA observatories chain separately for polar region, auroral zone and middle latitudes beginning from 1950. The variation consists of an annual and half-yearly waves. main attention is paid to time variability of the annual wave phase in the auroral zone, that is connected with superposition of waves of western and eastern jets

  7. Seasonal changes in the optical properties of dissolved organic matter (DOM) in large Arctic rivers

    DEFF Research Database (Denmark)

    Walker, S.A.; Amon, R.M.; Stedmon, Colin

    Arctic rivers deliver over 10% of the annual global river discharge yet little is known about the seasonal fluctuations in the quantity and quality of terrigenous dissolved organic matter (tDOM). A good constraint on such fluctuations is paramount to understand the role that climate change may have...... on tDOM input to the Arctic Ocean. To understand such changes the optical properties of colored tDOM (tCDOM) were studied. Samples were collected over several seasonal cycles from the six largest Arctic Rivers as part of the PARTNERS project. This unique dataset is the first of its kind capturing...

  8. Seasonal changes of buffalo colostrum: physicochemical parameters, fatty acids and cholesterol variation.

    Science.gov (United States)

    Coroian, Aurelia; Erler, Silvio; Matea, Cristian T; Mireșan, Vioara; Răducu, Camelia; Bele, Constantin; Coroian, Cristian O

    2013-02-26

    Colostrum has many beneficial effects on newborns due to its main compounds (proteins, fats, lactose, essential fatty acids, amino acids) as well as protective antibodies that confer to the body. The buffaloes are the second important species for milk production in the world after cows. The importance of the species is also conferred by a longer longevity, high dry content of milk and a strong organic resistance when compared with cows. The purpose of this study was to investigate the changes of buffalo colostrum compounds such as fatty acids, cholesterol and physicochemical parameters during the first seven days postpartum and under the impact of the season, summer on pasture and winter on dry diet (hay based). Fat from colostrum differs depending on the postpartum day showing mean values of 11.31-7.56% (summer season) and 11.22-7.51% (winter season). These values gradually decreased starting with first day postpartum until day seven. Dry substance and protein presented a similar evolution to fat reaching the lowest values at the end of the colostral period. Lactose, ash and pH showed a gradually increase reaching the maximum on day seven postpartum. The highest titres of fatty acids from colostrum are: butyric acid (C4:0), myristic acid (C14:0), palmitic acid (C16:0), oleic acid (C18:1) and the lowest values showed up in myristoleic acid (C14:1), cis-10-pentadecanoic acid (C15:1), pentadecylic acid (C15:0) and margaric acid (C17:0) for both seasons. Higher concentrations have been recorded for the summer season in general. Cholesterol concentration decreased from 12.93 and 12.68 mg/100 mL (summer and winter season) to 9.02 and 7.88 mg/100 mL in the end of the colostral period. Physicochemical compounds of buffalo colostrum were influenced by season and postpartum day of milking. Excepting lactose all other parameters gradually decreased during colostral period. Fatty acids and cholesterol showed the same evolution, presenting higher values for the summer season

  9. Post-processing scheme for modelling the lithospheric magnetic field

    Directory of Open Access Journals (Sweden)

    V. Lesur

    2013-03-01

    Full Text Available We investigated how the noise in satellite magnetic data affects magnetic lithospheric field models derived from these data in the special case where this noise is correlated along satellite orbit tracks. For this we describe the satellite data noise as a perturbation magnetic field scaled independently for each orbit, where the scaling factor is a random variable, normally distributed with zero mean. Under this assumption, we have been able to derive a model for errors in lithospheric models generated by the correlated satellite data noise. Unless the perturbation field is known, estimating the noise in the lithospheric field model is a non-linear inverse problem. We therefore proposed an iterative post-processing technique to estimate both the lithospheric field model and its associated noise model. The technique has been successfully applied to derive a lithospheric field model from CHAMP satellite data up to spherical harmonic degree 120. The model is in agreement with other existing models. The technique can, in principle, be extended to all sorts of potential field data with "along-track" correlated errors.

  10. Seasonal changes in the population of Menacanthus cornutus (Phthiraptera: Amblycera)

    OpenAIRE

    Kumar, Adesh; Kumar, Rakesh

    2013-01-01

    The chicken body louse, Menacanthus cornutus (Menoponidae s.l.) completes its whole life cycle on the body of Gallus gallus domesticus. The louse exploits the microclimate developed by host skin temperature and feather cover. The weekly visual examination has demonstrated the pronounced response on the population fluctuation of M. cornutus to the seasonal changes in the environment despite all favourable condition on the body of homothermic host. The experiments commences from April 2008. The...

  11. Quantifying the effects of climate and post-fire landscape change on hydrologic processes

    Science.gov (United States)

    Steimke, A.; Han, B.; Brandt, J.; Som Castellano, R.; Leonard, A.; Flores, A. N.

    2016-12-01

    Seasonally snow-dominated, forested mountain watersheds supply water to many human populations globally. However, the timing and magnitude of water delivery from these watersheds has already and will continue to change as the climate warms. Changes in vegetation also affect the runoff response of watersheds. The largest driver of vegetation change in many mountainous regions is wildfire, whose occurrence is affected by both climate and land management decisions. Here, we quantify how direct (i.e. changes in precipitation and temperature) and indirect (i.e. changing fire regimes) effects of climate change influence hydrologic parameters such as dates of peak streamflow, annual discharge, and snowpack levels. We used the Boise River Basin, ID as a model laboratory to calculate the relative magnitude of change stemming from direct and indirect effects of climate change. This basin is relevant to study as it is well-instrumented and major drainages have experienced burning at different spatial and temporal intervals, aiding in model calibration. We built a hydrology-based integrated model of the region using a multiagent simulation framework, Envision. We used a modified HBV (Hydrologiska Byråns Vattenbalansavdelning) rainfall-runoff model and calibrated it to historic streamflow and snowpack observations. We combined a diverse set of climate projections with wildfire scenarios (low vs. high) representing two distinct intervals in the regional historic fire record. In fire simulations, we altered land cover coefficients to reflect a burned state post-fire, which decreased overall evapotranspiration rates and increased water yields. However, direct climate effects had a larger signal on annual variations of hydrologic parameters. By comparing and analyzing scenario outputs, we identified links and sensitivities between land cover and regional hydrology in the context of a changing climate, with potential implications for local land and water managers. In future

  12. Novel Stable Isotope Methods for Assessing Changes in Seasonality of Precipitation from Sediments of Ombrotrophic Peatlands

    Science.gov (United States)

    Nichols, J. E.; Booth, R. K.; Jackson, S. T.; Pendall, E. G.; Walcott, M.; Bradley, R.; Pilcher, J.; Huang, Y.

    2007-12-01

    The seasonality of precipitation is a key but often elusive climate parameter in paleoclimate reconstructions. Sediments from ombrotrophic peatlands are excellent archives of past changes in precipitation/evaporation balance. Here we show that these peatland sediments can also be used to assess changes in the seasonality of precipitation. We have recently determined that distributions of Sphagnum and vascular plant biomarkers sensitively record changes in hydrologic balance (Nichols et al., 2006, Org. Geochem. 37, 1505-1513), but biomarker distributions alone do not offer detailed information for the changes in seasonal precipitation. In this study, we combine biomarker and compound-specific H and C isotope ratios to create a more comprehensive picture of the changing climate affecting these sensitive ombrotrophic systems. We present here two sets of downcore data from sites in Arctic Europe as well as Eastern North America. Basic paleohydrology is established using a ratio of Sphagnum to vascular plant biomarkers (C23 and C29 n-alkanes, respectively. We further describe paleohydrology using novel stable isotope proxies based on δD and δ13C measurements of Sphagnum and vascular plant biomarkers. Because Sphagnum has no vascular system and loses water directly by evaporation, Sphagnum biomarkers enriched in deuterium indicate an evaporative growing season (summer). Vascular plants use their root systems to take up water stored within the peatland, so deuterium-depleted vascular plant biomarkers should indicate increased winter recharge of the peatland. A methanotrophic symbiont living inside the Sphagnum's hyaline (water-holding) cells is more active when the Sphagnum is wet and therefore provides more 13C depleted (methane- derived) carbon dioxide for biomass production when the growing season is less evaporative. Hence, 13C depleted Sphagnum biomarkers indicate increased methanotrophy and therefore a wetter summer. We corroborate our stable isotope proxies by

  13. Comparison of seasonal variation in the fasting respiratory quotient of young Japanese, Polish and Thai women in relation to seasonal change in their percent body fat

    Directory of Open Access Journals (Sweden)

    Morinaka Tomoko

    2012-05-01

    Full Text Available Abstract Background From the viewpoint of human physiological adaptability, we previously investigated seasonal variation in the amount of unabsorbed dietary carbohydrates from the intestine after breakfast in Japanese, Polish and Thai participants. In this investigation we found that there were significant seasonal variations in the amount of unabsorbed dietary carbohydrates in Japanese and Polish participants, while we could not find significant seasonal variation in Thai participants. These facts prompted us to examine seasonal variations in the respiratory quotient after an overnight fast (an indicator of the ratio of carbohydrate and fat oxidized after the last meal with female university students living in Osaka (Japan, Poznan (Poland and Chiang Mai (Thailand. Methods We enrolled 30, 33 and 32 paid participants in Japan, Poland and Thailand, respectively, and measurements were taken over the course of one full year. Fasting respiratory quotient was measured with the participants in their postabsorptive state (after 12 hours or more fasting before respiratory quotient measurement. Respiratory quotient measurements were carried out by means of indirect calorimetry using the mixing chamber method. The percent body fat was measured using an electric bioelectrical impedance analysis scale. Food intake of the participants in Osaka and Poznan were carried out by the Food Frequency Questionnaire method. Results There were different seasonal variations in the fasting respiratory quotient values in the three different populations; with a significant seasonal variation in the fasting respiratory quotient values in Japanese participants, while those in Polish and Thai participants were non-significant. We found that there were significant seasonal changes in the percent body fat in the three populations but we could not find any significant correlation between the fasting respiratory quotient values and the percent body fat. Conclusions There were

  14. Seasonal changes in camera-based indices from an open canopy black spruce forest in Alaska, and comparison with indices from a closed canopy evergreen coniferous forest in Japan

    Science.gov (United States)

    Nagai, Shin; Nakai, Taro; Saitoh, Taku M.; Busey, Robert C.; Kobayashi, Hideki; Suzuki, Rikie; Muraoka, Hiroyuki; Kim, Yongwon

    2013-06-01

    Evaluation of the carbon, water, and energy balances in evergreen coniferous forests requires accurate in situ and satellite data regarding their spatio-temporal dynamics. Daily digital camera images can be used to determine the relationships among phenology, gross primary productivity (GPP), and meteorological parameters, and to ground-truth satellite observations. In this study, we examine the relationship between seasonal variations in camera-based canopy surface indices and eddy-covariance-based GPP derived from field studies in an Alaskan open canopy black spruce forest and in a Japanese closed canopy cedar forest. The ratio of the green digital number to the total digital number, hue, and GPP showed a bell-shaped seasonal profile at both sites. Canopy surface images for the black spruce forest and cedar forest mainly detected seasonal changes in vegetation on the floor of the forest and in the tree canopy, respectively. In contrast, the seasonal cycles of the ratios of the red and blue digital numbers to the total digital numbers differed between the two sites, possibly due to differences in forest structure and leaf color. These results suggest that forest structural characteristics, such as canopy openness and seasonal forest-floor changes, should be considered during continuous observations of phenology in evergreen coniferous forests.

  15. Post Fire Vegetation Recovery in Greece after the large Drought event of 2007

    Science.gov (United States)

    Gouveia, Célia M.; Bastos, Ana; DaCamara, Carlos; Trigo, Ricardo

    2013-04-01

    Fire is a natural factor of Mediterranean ecosystems. However, fire regimes in the European Mediterranean areas have been changing in the last decades, mainly due to land-use changes and climate driven factors possibly associated with climatic warming (e.g. decline of precipitation, increasing temperatures but also higher frequency of heatwaves). In Greece, the fire season of 2007 was particularly devastating, achieving the new all-time record of estimated burnt area (225 734 ha), since 1980. Additionally, we must stress that prior to the summer fire season in 2007, Greece suffered an exceptional drought event. This severe drought had a strong negative impact in vegetation dynamics. Since water availability is a crucial factor in post-fire vegetation recovery, it is desirable to assess the impact that such water-stress conditions had on fire sensitivity and post-fire vegetation recovery. Based on monthly values of NDVI, at the 1km×1km spatial scale, as obtained from the VEGETATION-SPOT5 instrument, from 1999 to 2010, large burnt scars are identified in Greece, during 2007 fire season. Vegetation recovery is then assessed based on a mono parametric regression model originally developed by Gouveia et al. (2010) to identify large burnt scars in Portugal during the 2003 fire season and after applied to 2005 fire season (Bastos et al., 2012). Some large burnt areas are selected and the respective NDVI behaviour is monitored throughout the pre and the post fire period. The vegetation dynamics during the pre-fire period is analysed and related to the extreme climatic events that characterised the considered period. An analysis is made of the dependence of recovery rates on land cover types and fire damage. Finally results are compared to results already obtained for Portugal (Gouveia et al. 2010). This work emphasises the use of a simple methodology, when applied to low resolution satellite imagery in order to monitor vegetation recovery after large fires events over

  16. Circular Migration as Climate Change Adaptation: Reconceptualising New Zealand´s and Australia’s Seasonal Worker Programs

    Directory of Open Access Journals (Sweden)

    Christine Brickenstein

    2013-12-01

    Full Text Available This paper looks into an aspect of adaptation, namely the role of the circular migration as climate change adaptation. It focuses on two of the Pacific region’s recently well -known seasonal labor schemes, Namely Australia’s Seasonal Workers Program (SWP and New Zealand ‘s recognized Seasonal Employer Scheme (RSE, and asks if beyond the current goals the schemes May be reconceptualsed as adaptation programs responsive not only towards developmental and economic Concerns but the wider (and interconnected With the first two climate change challenges. According to MacDermott and Opeskin, labor mobility schemes, for the sending country focus on the “development perspective “such as (a Employment Opportunities, (b Regular benefits of Remittances and (c skills enhancement, while receiving countries country can meet the challenges posed by labor shortages in seasonal industries where “a reliable workforce is lacking”.

  17. Seasonal changes in nasal cytology in mite-allergic patients

    Directory of Open Access Journals (Sweden)

    Gelardi M

    2014-03-01

    Full Text Available Matteo Gelardi,1 Diego G Peroni,2 Cristoforo Incorvaia,3 Nicola Quaranta,1 Concetta De Luca,1 Salvatore Barberi,4 Ilaria Dell'Albani,5 Massimo Landi,6 Franco Frati,5 Olivier de Beaumont7 1Otolaryngology Unit, Department of Neuroscience and Sensory Organs, University of Bari, Bari, Italy; 2Department of Pediatrics, University of Verona, Verona, Italy; 3Allergy/Pulmonary Rehabilitation, ICP Hospital, Milan, Italy; 4Department of Pediatrics, San Paolo Hospital, Milan, Italy; 5Medical and Scientific Department, Stallergenes, Milan, Italy; 6Department of Pediatrics, National Healthcare System, ASL TO1, Turin, Italy; 7Medical Affairs Department, Stallergenes, Antony, France Background: House dust mites (HDMs are a major cause of allergic rhinitis (AR and asthma worldwide. Recent studies suggested that the allergen load presents seasonal modifications, giving rise to seasonal variation in nasal inflammation and symptoms. The aim of this study was to evaluate by nasal cytology whether nasal inflammation in mite-allergic patients changes with the seasons of the year. Methods: The study included 16 patients (seven males and nine females, mean age 38.1 years with persistent AR caused by monosensitization to HDMs. Nasal cytology was performed in all patients once monthly for 1 year. Results: Nasal cytology showed that the cells most commonly detected in the nasal mucosa were neutrophils. During the period from October to April, a peak in the number of neutrophils and also the presence of significant numbers of eosinophils, mast cells, and lymphocytes/plasma cells were found, which shows the occurrence of more intense inflammation during these months. Conclusion: Nasal cytology provides useful data in detecting nasal inflammation and its association with the clinical stage of AR. The seasonal variations in nasal cytology are likely to be induced by the fluctuations in the HDM allergen that have been uncovered in recent investigations. Keywords: allergens

  18. Earlier Snowmelt Changes the Ratio Between Early and Late Season Forest Productivity

    Science.gov (United States)

    Knowles, J. F.; Molotch, N. P.; Trujillo, E.; Litvak, M. E.

    2017-12-01

    Future projections of declining snowpack and increasing potential evaporation associated with climate warming are predicted to advance the timing of snowmelt in mountain ecosystems globally. This scenario has direct implications for snowmelt-driven forest productivity, but the net effect of temporally shifting moisture dynamics is unknown with respect to the annual carbon balance. Accordingly, this study uses both satellite- and tower-based observations to document the forest productivity response to snowpack and potential evaporation variability between 1989 and 2012 throughout the southern Rocky Mountain ecoregion, USA. These results show that a combination of low snow accumulation and record high potential evaporation in 2012 resulted in the 34-year minimum ecosystem productivity that could be indicative of future conditions. Moreover, early and late season productivity were significantly and inversely related, suggesting that future shifts toward earlier or reduced snowmelt could increase late-season moisture stress to vegetation and thus restrict productivity despite a longer growing season. This relationship was further subject to modification by summer precipitation, and the controls on the early/late season productivity ratio are explored within the context of ecosystem carbon storage in the future. Any perturbation to the carbon cycle at this scale represents a potential feedback to climate change since snow-covered forests represent an important global carbon sink.

  19. Seasonal changes of progesterone and testosterone contents in hair of giant pandas

    International Nuclear Information System (INIS)

    Guo Dazhi; Liu Xianyi; Chen Faju

    1994-01-01

    Seasonal changes of progesterone content (PSC) in hair of three female giant pandas and testosterone content (TSC) in hair of two male giant pandas were tested by radioimmunoassay. During March to early June, PSC in two non-pregnant giant pandas (x-bar+-SD = 13.40 +- 10.06 and 10.60 +- 8.88 ng/g hair respectively) were higher than those in non-breeding season (3.07 +-1.07 and 3.20 +- 1.15 ng/g, P<0.01). PSC in a 18-year-old female giant panda remained at low levels (2.72 +- 1.49 ng/g) during March to December. In a twin-bear giant panda, PSC (6.77 +- 3.66 ng/g) appeared higher than that in non-pregnant giant pandas in non-breeding season. Around February to the end of May, TSC in two male giant pandas (1.89 +- 1.71 and 1.82 +- 1.04 ng/g respectively) were also higher than that in non-breeding season (0.98 +- 0.57 and 0.75 +- 0.39 ng/g, P<0.01). the findings from the study implied that giant panda's hair is possible to be used as a specimen to carry out steroids research in the endangered species

  20. Seasonal and Static Gravity Field of Mars from MGS, Mars Odyssey and MRO Radio Science

    Science.gov (United States)

    Genova, Antonio; Goossens, Sander; Lemoine, Frank G.; Mazarico, Erwan; Neumann, Gregory A.; Smith, David E.; Zuber, Maria T.

    2016-01-01

    We present a spherical harmonic solution of the static gravity field of Mars to degree and order 120, GMM-3, that has been calculated using the Deep Space Network tracking data of the NASA Mars missions, Mars Global Surveyor (MGS), Mars Odyssey (ODY), and the Mars Reconnaissance Orbiter (MRO). We have also jointly determined spherical harmonic solutions for the static and time-variable gravity field of Mars, and the Mars k 2 Love numbers, exclusive of the gravity contribution of the atmosphere. Consequently, the retrieved time-varying gravity coefficients and the Love number k 2 solely yield seasonal variations in the mass of the polar caps and the solid tides of Mars, respectively. We obtain a Mars Love number k 2 of 0.1697 +/-0.0027 (3- sigma). The inclusion of MRO tracking data results in improved seasonal gravity field coefficients C 30 and, for the first time, C 50 . Refinements of the atmospheric model in our orbit determination program have allowed us to monitor the odd zonal harmonic C 30 for approx.1.5 solar cycles (16 years). This gravity model shows improved correlations with MOLA topography up to 15% larger at higher harmonics ( l = 60–80) than previous solutions.

  1. Seasonal Changes in Titan's Meteorology

    Science.gov (United States)

    Turtle, E. P.; DelGenio, A. D.; Barbara, J. M.; Perry, J. E.; Schaller, E. L.; McEwen, A. S.; West, R. A.; Ray, T. L.

    2011-01-01

    The Cassini Imaging Science Subsystem has observed Titan for 1/4 Titan year, and we report here the first evidence of seasonal shifts in preferred locations of tropospheric methane clouds. South \\polar convective cloud activity, common in late southern summer, has become rare. North \\polar and northern mid \\latitude clouds appeared during the approach to the northern spring equinox in August 2009. Recent observations have shown extensive cloud systems at low latitudes. In contrast, southern mid \\latitude and subtropical clouds have appeared sporadically throughout the mission, exhibiting little seasonality to date. These differences in behavior suggest that Titan s clouds, and thus its general circulation, are influenced by both the rapid temperature response of a low \\thermal \\inertia surface and the much longer radiative timescale of Titan s cold thick troposphere. North \\polar clouds are often seen near lakes and seas, suggesting that local increases in methane concentration and/or lifting generated by surface roughness gradients may promote cloud formation. Citation

  2. Climate change effect on Betula (birch) and Quercus (oak) pollen seasons in the United States

    Science.gov (United States)

    Zhang, Yong; Bielory, Leonard; Georgopoulos, Panos G.

    2014-07-01

    Climatic change is expected to affect the spatiotemporal patterns of airborne allergenic pollen, which has been found to act synergistically with common air pollutants, such as ozone, to cause allergic airway disease (AAD). Observed airborne pollen data from six stations from 1994 to 2011 at Fargo (North Dakota), College Station (Texas), Omaha (Nebraska), Pleasanton (California), Cherry Hill and Newark (New Jersey) in the US were studied to examine climate change effects on trends of annual mean and peak value of daily concentrations, annual production, season start, and season length of Betula (birch) and Quercus (oak) pollen. The growing degree hour (GDH) model was used to establish a relationship between start/end dates and differential temperature sums using observed hourly temperatures from surrounding meteorology stations. Optimum GDH models were then combined with meteorological information from the Weather Research and Forecasting (WRF) model, and land use land coverage data from the Biogenic Emissions Land use Database, version 3.1 (BELD3.1), to simulate start dates and season lengths of birch and oak pollen for both past and future years across the contiguous US (CONUS). For most of the studied stations, comparison of mean pollen indices between the periods of 1994-2000 and 2001-2011 showed that birch and oak trees were observed to flower 1-2 weeks earlier; annual mean and peak value of daily pollen concentrations tended to increase by 13.6 %-248 %. The observed pollen season lengths varied for birch and for oak across the different monitoring stations. Optimum initial date, base temperature, and threshold GDH for start date was found to be 1 March, 8 °C, and 1,879 h, respectively, for birch; 1 March, 5 °C, and 4,760 h, respectively, for oak. Simulation results indicated that responses of birch and oak pollen seasons to climate change are expected to vary for different regions.

  3. Ammonia-Oxidizing Archaea Are More Resistant Than Denitrifiers to Seasonal Precipitation Changes in an Acidic Subtropical Forest Soil

    Directory of Open Access Journals (Sweden)

    Jie Chen

    2017-07-01

    Full Text Available Seasonal precipitation changes are increasingly severe in subtropical areas. However, the responses of soil nitrogen (N cycle and its associated functional microorganisms to such precipitation changes remain unclear. In this study, two projected precipitation patterns were manipulated: intensifying the dry-season drought (DD and extending the dry-season duration (ED but increasing the wet-season storms following the DD and ED treatment period. The effects of these two contrasting precipitation patterns on soil net N transformation rates and functional gene abundances were quantitatively assessed through a resistance index. Results showed that the resistance index of functional microbial abundance (-0.03 ± 0.08 was much lower than that of the net N transformation rate (0.55 ± 0.02 throughout the experiment, indicating that microbial abundance was more responsive to precipitation changes compared with the N transformation rate. Spring drought under the ED treatment significantly increased the abundances of both nitrifying (amoA and denitrifying genes (nirK, nirS, and nosZ, while changes in these gene abundances overlapped largely with control treatment during droughts in the dry season. Interestingly, the resistance index of the ammonia-oxidizing archaea (AOA amoA abundance was significantly higher than that of the denitrifying gene abundances, suggesting that AOA were more resistant to the precipitation changes. This was attributed to the stronger environmental adaptability and higher resource utilization efficiency of the AOA community, as indicated by the lack of correlations between AOA gene abundance and environmental factors [i.e., soil water content, ammonium (NH4+ and dissolved organic carbon concentrations] during the experiment.

  4. Seasonal change of residence time in spring water and groundwater at a mountainous headwater catchment

    Science.gov (United States)

    Nagano, Kosuke; Tsujimura, Maki; Onda, Yuichi; Iwagami, Sho; Sakakibara, Koichi; Sato, Yutaro

    2017-04-01

    Determination of water age in headwater is important to consider water pathway, source and storage in the catchment. Previous studies showed that groundwater residence time changes seasonally. These studies reported that mean residence time of water in dry season tends to be longer than that in rainy season, and it becomes shorter as precipitation and discharge amount increases. However, there are few studies to clarify factors causing seasonal change in mean residence time in spring water and groundwater based on observed data. Therefore, this study aims to reveal the relationship between mean residence time and groundwater flow system using SFconcentration in spring and 10 minutes interval hydrological data such as discharge volume, groundwater level and precipitation amount in a headwater catchment in Fukushima, Japan. The SF6 concentration data in spring water observed from April 2015 to November 2016 shows the mean residence time of springs ranged from zero to 14 years. We also observed a clear negative correlation between discharge rate and residence time in the spring. The residence time in shallow groundwater in rainy season was younger as compared with that in low rainfall period. Therefore, the shallow groundwater with young residence time seems to contribute to the spring in rainy season, causing shorter residence time. Additionally, the residence time of groundwater ranged from 3 to 5 years even in low rainfall period. The residence time in high groundwater table level in ridge was older as compared with that in low groundwater table level. These suggest that the contribution of groundwater with older age in the ridge becomes dominant in the low discharge.

  5. Using Accretionary Hard Parts to Study Changes in Seasonality over Geologic Time

    Science.gov (United States)

    Ivany, L. C.; Judd, E. J.

    2017-12-01

    Seasonality has been an enigma for deep-time research. Proxies for mean annual temperature (MAT) are the mainstay of paleoclimate studies, and while these are tremendously informative, seasonal extremes are the variables that matter most for many paleoclimatic, paleoceanographic, and physiologic processes. Seasonality has been difficult to constrain in the rock record, however, because of the need for subannual resolution - very few such archives exist. One of the most promising comes in the form of the mineralized hard parts of organisms that grow by accretion, e.g., mollusks, corals, fish otoliths. Such materials carry a chemical signature of temperature at the time of precipitation, allowing for assessment of the seasonal temperature extremes experienced by the organism. Interpretation of these records in the context of climate, however, are complicated by the overprint of biology - organisms don't necessarily grow all year long, resulting in a truncation of the seasonal cycle regardless of sampling resolution. Furthermore, unrecognized differences in depositional environment or taxon ecology among samples can make comparisons over time even more tenuous. Even with internally consistent datasets, assessment of pattern is rarely based on more than visual inspection. An iterative computational procedure predicated on the assumption of sinusoidal variation in temperature and growth rate can circumvent these concerns. Deviations in the shape of oxygen isotope profiles from the predicted sinusoid allow recovery of the mean and amplitude of temperature variation as well as the timing and duration of growth within years. Estimates of such parameters from multiple specimens allow for meaningful comparisons over time, both for seasonality and the growth response of organisms. We apply this approach to datasets of seasonal variation through the Paleogene of the US Gulf Coastal Plain and the Eocene of Antarctica derived largely from marine bivalve mollusks. In the

  6. Post-Processing Approach for Refining Raw Land Cover Change Detection of Very High-Resolution Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Zhiyong Lv

    2018-03-01

    Full Text Available In recent decades, land cover change detection (LCCD using very high-spatial resolution (VHR remote sensing images has been a major research topic. However, VHR remote sensing images usually lead to a large amount of noises in spectra, thereby reducing the reliability of the detected results. To solve this problem, this study proposes an object-based expectation maximization (OBEM post-processing approach for enhancing raw LCCD results. OBEM defines a refinement of the labeling in a detected map to enhance its raw detection accuracies. Current mainstream change detection (preprocessing techniques concentrate on proposing a change magnitude measurement or considering image spatial features to obtain a change detection map. The proposed OBEM approach is a new solution to enhance change detection accuracy by refining the raw result. Post-processing approaches can achieve competitive accuracies to the preprocessing methods, but in a direct and succinct manner. The proposed OBEM post-processing method synthetically considers multi-scale segmentation and expectation maximum algorithms to refine the raw change detection result. Then, the influence of the scale of segmentation on the LCCD accuracy of the proposed OBEM is investigated. Four pairs of remote sensing images, one of two pairs (aerial image with 0.5 m/pixel resolution which depict two landslide sites on Landtau Island, Hong Kong, China, are used in the experiments to evaluate the effectiveness of the proposed approach. In addition, the proposed approach is applied, and validated by two case studies, LCCD in Tianjin City China (SPOT-5 satellite image with 2.5 m/pixel resolution and Mexico forest fire case (Landsat TM images with 30 m/pixel resolution, respectively. Quantitative evaluations show that the proposed OBEM post-processing approach can achieve better performance and higher accuracies than several commonly used preprocessing methods. To the best of the authors’ knowledge, this type

  7. An integrated, indicator framework for assessing large-scale variations and change in seasonal timing and phenology (Invited)

    Science.gov (United States)

    Betancourt, J. L.; Weltzin, J. F.

    2013-12-01

    As part of an effort to develop an Indicator System for the National Climate Assessment (NCA), the Seasonality and Phenology Indicators Technical Team (SPITT) proposed an integrated, continental-scale framework for understanding and tracking seasonal timing in physical and biological systems. The framework shares several metrics with the EPA's National Climate Change Indicators. The SPITT framework includes a comprehensive suite of national indicators to track conditions, anticipate vulnerabilities, and facilitate intervention or adaptation to the extent possible. Observed, modeled, and forecasted seasonal timing metrics can inform a wide spectrum of decisions on federal, state, and private lands in the U.S., and will be pivotal for international efforts to mitigation and adaptation. Humans use calendars both to understand the natural world and to plan their lives. Although the seasons are familiar concepts, we lack a comprehensive understanding of how variability arises in the timing of seasonal transitions in the atmosphere, and how variability and change translate and propagate through hydrological, ecological and human systems. For example, the contributions of greenhouse warming and natural variability to secular trends in seasonal timing are difficult to disentangle, including earlier spring transitions from winter (strong westerlies) to summer (weak easterlies) patterns of atmospheric circulation; shifts in annual phasing of daily temperature means and extremes; advanced timing of snow and ice melt and soil thaw at higher latitudes and elevations; and earlier start and longer duration of the growing and fire seasons. The SPITT framework aims to relate spatiotemporal variability in surface climate to (1) large-scale modes of natural climate variability and greenhouse gas-driven climatic change, and (2) spatiotemporal variability in hydrological, ecological and human responses and impacts. The hierarchical framework relies on ground and satellite observations

  8. Mercury speciation driven by seasonal changes in a contaminated estuarine environment

    Energy Technology Data Exchange (ETDEWEB)

    Bratkič, Arne, E-mail: arne.bratkic@ijs.si [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Ogrinc, Nives, E-mail: nives.orginc@ijs.si [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Kotnik, Jože, E-mail: joze.kotnik@ijs.si [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Faganeli, Jadran, E-mail: faganeli@mbss.org [Marine Biology Station, Fornače 41, 6330 Piran (Slovenia); Žagar, Dušan, E-mail: dusan.zagar@fgg.uni-lj.si [Faculty of Civil and Geodetic Engineering, Jamova 2, 1000 Ljubljana (Slovenia); Yano, Shinichiro [Faculty of Engineering, Kyushu University, Fukuoka 812-8581 (Japan); Tada, Akihide, E-mail: tada@civil.nagasaki-u.ac.jp [Faculty of Engineering, Nagasaki University, Bunkyo-machi 1-14, Nagasaki 852-8521 (Japan); Horvat, Milena, E-mail: milena.horvat@ijs.si [Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)

    2013-08-15

    In this study, seasonal changes of mercury (Hg) species in the highly variable estuary of Soča/Isonzo River (northern Adriatic Sea) were investigated. Samplings were performed on a seasonal basis (September 2009, May, August and October 2010) and Hg species (total Hg, methylmercury (MeHg), dissolved gaseous Hg (DGM)) in waters, sediments and pore waters were determined. In addition, a range of ancillary parameters were measured (salinity, nutrients, organic carbon (OC), nitrogen species). Hg values were interpreted using these parameters and hydrological conditions (river flow, wave height) around the time of sampling. There were no significant changes in Hg load from river to the gulf, compared to previous studies. The load was temporarily higher in May 2010 due to higher river flow. Wave height, through changing hydrostatic pressure, was most likely to cause resuspension of already deposited Hg from the bottom (August 2010). The estuary is a net source of DGM to the atmosphere as suggested by DGM profiles, with salinity, redox potential and organic matter as the most probable controls over its production. MeHg is produced in situ in sediment or in water column, rather than transported by river, as indicated by its correlation with OC of the marine origin. Calculated fluxes for THg and MeHg showed sediment as a source for both the water column. In pore waters, OC in part affects partitioning of both THg and MeHg; however other factors (e.g. sulphide and/or oxyhydroxides precipitation and dissolution) are also probably important. -- Highlights: ► Water, sediment and pore water mercury species in front of Soča River estuary were measured. ► Seasonally variable hydrological conditions were shown to influence water column Hg speciation. ► Fluxes for total Hg and MeHg from sediment to water were calculated. ► Sediment is a source of total Hg and MeHg to the water column. ► Correlation of MeHg with organic carbon of marine origin suggests in situ formation.

  9. Post-material values and environmental policy change

    Energy Technology Data Exchange (ETDEWEB)

    Watts, N. (International Inst. for Environmental and Society, Berlin, Germany); Wandesforde-Smith, G.

    Environmental policy may be particularly suited as a vehicle to articulate post-material values in advanced industrial societies, and recognition of this is likely to prove enormously helpful in future comparative and cross-national research into the origins of environmentalism and the causes of environmental policy change. The paper notes the salient characteristics of post-materialism and the overlap of these with the leading indicators of environmentalism. Possible structural causes for this overlap are noted and opposed to the prevailing socialization explanation for the adoption of post-material and environmental values. To help understand the impact of environmentalism on policy, an idealized development of the movement is sketched. This leads to the description of a set of general factors likely to be related to the way environmentalism finds political expressions in various countries. In the final section, the focus is on what we might want to know about the policy process in order to be able to gauge environmentalist influence on policy outputs. 20 references.

  10. Changes in vegetation structure and aboveground biomass in ...

    African Journals Online (AJOL)

    Changes in vegetation structure and aboveground biomass in response to traditional rangeland management practices in Borana, southern Ethiopia. ... managed by prescribed fire for five years and grazed only post-fire during dry seasons.

  11. Seasonal difference in brain serotonin transporter binding predicts symptom severity in patients with seasonal affective disorder

    DEFF Research Database (Denmark)

    Mc Mahon, Brenda; Andersen, Sofie B.; Madsen, Martin K.

    2016-01-01

    controls with low seasonality scores and 17 patients diagnosed with seasonal affective disorder were scanned in both summer and winter to investigate differences in cerebral serotonin transporter binding across groups and across seasons. The two groups had similar cerebral serotonin transporter binding...... between summer and winter (Psex-(P = 0.02) and genotype-(P = 0.04) dependent. In the patients with seasonal affective disorder, the seasonal change in serotonin transporter binding was positively associated with change in depressive symptom...

  12. Strategies to evaluate goodness of reference strips for in-season, field scale, irrigated corn nitrogen sufficiency

    Science.gov (United States)

    The nitrogen (N) sufficiency approach to assess plant N status for in-season N management requires a non-N-limiting reference to make N recommendations. Use of reference strips in fields with spatially variable soils and the impact this variability has within N enriched reference strips are not we...

  13. Impacts of climate change on rainfall, seasonal flooding, and evapotranspiration in the Okavango Delta, Botswana

    Science.gov (United States)

    Konecky, B. L.; Noone, D.; Mosimanyana, E.; Gondwe, M.

    2016-12-01

    The Okavango Delta in northern Botswana is one of the world's richest biodiversity hotspots. A UNESCO World Heritage Site, the Delta is known for its unique annual flood pulse, whereby the wetland and its neighboring river systems are inundated with waters that travel nearly 1000 km before reaching this subtropical, semi-arid destination. The livelihoods of northern Botswana's ecosystems and human populations rely on these floods to supplement the short and variable rainy season, which in many years is too minimal to ameliorate regional drought. However, anthropogenic climate change is reducing the amount of water that reaches the delta by increasing evaporation from soils and rivers, and transpiration by vegetation, during its long transit to Botswana. Future changes in rainfall patterns, extreme events, and increased upstream water use could exacerbate this water stress. Unfortunately, it remains difficult to assess the impacts of climate change on the delta because few data exist to constrain its complex climatic and seasonal water cycling regimes. This study presents a novel characterization of the water cycle in and around the Okavango Delta based on a survey of free-flowing surface waters, stagnant pools, precipitation, and groundwater carried out during the 2016 rainy and early-flood season. We use stable isotope and water quality data to assess local moisture sources, transport, evaporation, wetland flushing, and land-atmosphere exchanges, all of which are subject to change under global warming. We find a strong evaporation gradient and a progressive flushing of stagnant swamp waters along the northeastern and northwestern channels of the Delta. The evaporation gradient is more limited in nearby rivers with more limited wetlands. We contrast results with a survey of the Delta performed in the 1970's in order to assess changes over the past 40 years. Since some of these changes may arise from rainfall supply, we also present new analysis of rainfall moisture

  14. Seasonal provenance changes in present-day Saharan dust collected in and off Mauritania

    Directory of Open Access Journals (Sweden)

    C. A. Friese

    2017-08-01

    Full Text Available Saharan dust has a crucial influence on the earth climate system and its emission, transport and deposition are intimately related to, e.g., wind speed, precipitation, temperature and vegetation cover. The alteration in the physical and chemical properties of Saharan dust due to environmental changes is often used to reconstruct the climate of the past. However, to better interpret possible climate changes the dust source regions need to be known. By analysing the mineralogical composition of transported or deposited dust, potential dust source areas can be inferred. Summer dust transport off northwest Africa occurs in the Saharan air layer (SAL. In continental dust source areas, dust is also transported in the SAL; however, the predominant dust input occurs from nearby dust sources with the low-level trade winds. Hence, the source regions and related mineralogical tracers differ with season and sampling location. To test this, dust collected in traps onshore and in oceanic sediment traps off Mauritania during 2013 to 2015 was analysed. Meteorological data, particle-size distributions, back-trajectory and mineralogical analyses were compared to derive the dust provenance and dispersal. For the onshore dust samples, the source regions varied according to the seasonal changes in trade-wind direction. Gibbsite and dolomite indicated a Western Saharan and local source during summer, while chlorite, serpentine and rutile indicated a source in Mauritania and Mali during winter. In contrast, for the samples that were collected offshore, dust sources varied according to the seasonal change in the dust transporting air layer. In summer, dust was transported in the SAL from Mauritania, Mali and Libya as indicated by ferroglaucophane and zeolite. In winter, dust was transported with the trades from Western Sahara as indicated by, e.g., fluellite.

  15. Consistency of Vegetation Index Seasonality Across the Amazon Rainforest

    Science.gov (United States)

    Maeda, Eduardo Eiji; Moura, Yhasmin Mendes; Wagner, Fabien; Hilker, Thomas; Lyapustin, Alexei I.; Wang, Yujie; Chave, Jerome; Mottus, Matti; Aragao, Luiz E.O.C.; Shimabukuro, Yosio

    2016-01-01

    Vegetation indices (VIs) calculated from remotely sensed reflectance are widely used tools for characterizing the extent and status of vegetated areas. Recently, however, their capability to monitor the Amazon forest phenology has been intensely scrutinized. In this study, we analyze the consistency of VIs seasonal patterns obtained from two MODIS products: the Collection 5 BRDF product (MCD43) and the Multi-Angle Implementation of Atmospheric Correction algorithm (MAIAC). The spatio-temporal patterns of the VIs were also compared with field measured leaf litterfall, gross ecosystem productivity and active microwave data. Our results show that significant seasonal patterns are observed in all VIs after the removal of view-illumination effects and cloud contamination. However, we demonstrate inconsistencies in the characteristics of seasonal patterns between different VIs and MODIS products. We demonstrate that differences in the original reflectance band values form a major source of discrepancy between MODIS VI products. The MAIAC atmospheric correction algorithm significantly reduces noise signals in the red and blue bands. Another important source of discrepancy is caused by differences in the availability of clear-sky data, as the MAIAC product allows increased availability of valid pixels in the equatorial Amazon. Finally, differences in VIs seasonal patterns were also caused by MODIS collection 5 calibration degradation. The correlation of remote sensing and field data also varied spatially, leading to different temporal offsets between VIs, active microwave and field measured data. We conclude that recent improvements in the MAIAC product have led to changes in the characteristics of spatio-temporal patterns of VIs seasonality across the Amazon forest, when compared to the MCD43 product. Nevertheless, despite improved quality and reduced uncertainties in the MAIAC product, a robust biophysical interpretation of VIs seasonality is still missing.

  16. Consistency of vegetation index seasonality across the Amazon rainforest

    Science.gov (United States)

    Maeda, Eduardo Eiji; Moura, Yhasmin Mendes; Wagner, Fabien; Hilker, Thomas; Lyapustin, Alexei I.; Wang, Yujie; Chave, Jérôme; Mõttus, Matti; Aragão, Luiz E. O. C.; Shimabukuro, Yosio

    2016-10-01

    Vegetation indices (VIs) calculated from remotely sensed reflectance are widely used tools for characterizing the extent and status of vegetated areas. Recently, however, their capability to monitor the Amazon forest phenology has been intensely scrutinized. In this study, we analyze the consistency of VIs seasonal patterns obtained from two MODIS products: the Collection 5 BRDF product (MCD43) and the Multi-Angle Implementation of Atmospheric Correction algorithm (MAIAC). The spatio-temporal patterns of the VIs were also compared with field measured leaf litterfall, gross ecosystem productivity and active microwave data. Our results show that significant seasonal patterns are observed in all VIs after the removal of view-illumination effects and cloud contamination. However, we demonstrate inconsistencies in the characteristics of seasonal patterns between different VIs and MODIS products. We demonstrate that differences in the original reflectance band values form a major source of discrepancy between MODIS VI products. The MAIAC atmospheric correction algorithm significantly reduces noise signals in the red and blue bands. Another important source of discrepancy is caused by differences in the availability of clear-sky data, as the MAIAC product allows increased availability of valid pixels in the equatorial Amazon. Finally, differences in VIs seasonal patterns were also caused by MODIS collection 5 calibration degradation. The correlation of remote sensing and field data also varied spatially, leading to different temporal offsets between VIs, active microwave and field measured data. We conclude that recent improvements in the MAIAC product have led to changes in the characteristics of spatio-temporal patterns of VIs seasonality across the Amazon forest, when compared to the MCD43 product. Nevertheless, despite improved quality and reduced uncertainties in the MAIAC product, a robust biophysical interpretation of VIs seasonality is still missing.

  17. Changes in vegetation phenology are not reflected in atmospheric CO2 and 13 C/12 C seasonality.

    Science.gov (United States)

    Gonsamo, Alemu; D'Odorico, Petra; Chen, Jing M; Wu, Chaoyang; Buchmann, Nina

    2017-10-01

    Northern terrestrial ecosystems have shown global warming-induced advances in start, delays in end, and thus increased lengths of growing season and gross photosynthesis in recent decades. The tradeoffs between seasonal dynamics of two opposing fluxes, CO 2 uptake through photosynthesis and release through respiration, determine the influence of the terrestrial ecosystem on the atmospheric CO 2 and 13 C/ 12 C seasonality. Here, we use four CO 2 observation stations in the Northern Hemisphere, namely Alert, La Jolla, Point Barrow, and Mauna Loa Observatory, to determine how changes in vegetation productivity and phenology, respiration, and air temperature affect both the atmospheric CO 2 and 13 C/ 12 C seasonality. Since the 1960s, the only significant long-term trend of CO 2 and 13 C/ 12 C seasonality was observed at the northern most station, Alert, where the spring CO 2 drawdown dates advanced by 0.65 ± 0.55 days yr -1 , contributing to a nonsignificant increase in length of the CO 2 uptake period (0.74 ± 0.67 days yr -1 ). For Point Barrow station, vegetation phenology changes in well-watered ecosystems such as the Canadian and western Siberian wetlands contributed the most to 13 C/ 12 C seasonality while the CO 2 seasonality was primarily linked to nontree vegetation. Our results indicate significant increase in the Northern Hemisphere soil respiration. This means, increased respiration of 13 C depleted plant materials cancels out the 12 C gain from enhanced vegetation activities during the start and end of growing season. These findings suggest therefore that parallel warming-induced increases both in photosynthesis and respiration contribute to the long-term stability of CO 2 and 13 C/ 12 C seasonality under changing climate and vegetation activity. The summer photosynthesis and the soil respiration in the dormant seasons have become more vigorous which lead to increased peak-to-through CO 2 amplitude. As the relative magnitude of the increased

  18. The value of seasonal forecasting and crop mix adaptation to climate variability for agriculture under climate change

    Science.gov (United States)

    Choi, H. S.; Schneider, U.; Schmid, E.; Held, H.

    2012-04-01

    Changes to climate variability and frequency of extreme weather events are expected to impose damages to the agricultural sector. Seasonal forecasting and long range prediction skills have received attention as an option to adapt to climate change because seasonal climate and yield predictions could improve farmers' management decisions. The value of seasonal forecasting skill is assessed with a crop mix adaptation option in Spain where drought conditions are prevalent. Yield impacts of climate are simulated for six crops (wheat, barely, cotton, potato, corn and rice) with the EPIC (Environmental Policy Integrated Climate) model. Daily weather data over the period 1961 to 1990 are used and are generated by the regional climate model REMO as reference period for climate projection. Climate information and its consequent yield variability information are given to the stochastic agricultural sector model to calculate the value of climate information in the agricultural market. Expected consumers' market surplus and producers' revenue is compared with and without employing climate forecast information. We find that seasonal forecasting benefits not only consumers but also producers if the latter adopt a strategic crop mix. This mix differs from historical crop mixes by having higher shares of crops which fare relatively well under climate change. The corresponding value of information is highly sensitive to farmers' crop mix choices.

  19. A Theoretical Approach to Understanding Population Dynamics with Seasonal Developmental Durations

    Science.gov (United States)

    Lou, Yijun; Zhao, Xiao-Qiang

    2017-04-01

    There is a growing body of biological investigations to understand impacts of seasonally changing environmental conditions on population dynamics in various research fields such as single population growth and disease transmission. On the other side, understanding the population dynamics subject to seasonally changing weather conditions plays a fundamental role in predicting the trends of population patterns and disease transmission risks under the scenarios of climate change. With the host-macroparasite interaction as a motivating example, we propose a synthesized approach for investigating the population dynamics subject to seasonal environmental variations from theoretical point of view, where the model development, basic reproduction ratio formulation and computation, and rigorous mathematical analysis are involved. The resultant model with periodic delay presents a novel term related to the rate of change of the developmental duration, bringing new challenges to dynamics analysis. By investigating a periodic semiflow on a suitably chosen phase space, the global dynamics of a threshold type is established: all solutions either go to zero when basic reproduction ratio is less than one, or stabilize at a positive periodic state when the reproduction ratio is greater than one. The synthesized approach developed here is applicable to broader contexts of investigating biological systems with seasonal developmental durations.

  20. Quantifying the association between white matter integrity changes and subconcussive head impact exposure from a single season of youth and high school football using 3D convolutional neural networks

    Science.gov (United States)

    Saghafi, Behrouz; Murugesan, Gowtham; Davenport, Elizabeth; Wagner, Ben; Urban, Jillian; Kelley, Mireille; Jones, Derek; Powers, Alexander; Whitlow, Christopher; Stitzel, Joel; Maldjian, Joseph; Montillo, Albert

    2018-02-01

    The effect of subconcussive head impact exposure during contact sports, including American football, on brain health is poorly understood particularly in young and adolescent players, who may be more vulnerable to brain injury during periods of rapid brain maturation. This study aims to quantify the association between cumulative effects of head impact exposure from a single season of football on white matter (WM) integrity as measured with diffusion MRI. The study targets football players aged 9-18 years old. All players were imaged pre- and post-season with structural MRI and diffusion tensor MRI (DTI). Fractional Anisotropy (FA) maps, shown to be closely correlated with WM integrity, were computed for each subject, co-registered and subtracted to compute the change in FA per subject. Biomechanical metrics were collected at every practice and game using helmet mounted accelerometers. Each head impact was converted into a risk of concussion, and the risk of concussion-weighted cumulative exposure (RWE) was computed for each player for the season. Athletes with high and low RWE were selected for a two-category classification task. This task was addressed by developing a 3D Convolutional Neural Network (CNN) to automatically classify players into high and low impact exposure groups from the change in FA maps. Using the proposed model, high classification performance, including ROC Area Under Curve score of 85.71% and F1 score of 83.33% was achieved. This work adds to the growing body of evidence for the presence of detectable neuroimaging brain changes in white matter integrity from a single season of contact sports play, even in the absence of a clinically diagnosed concussion.

  1. Seasonal Changes in Sleep Duration in African American and African College Students Living In Washington, D.C.

    Directory of Open Access Journals (Sweden)

    Janna Volkov

    2007-01-01

    Full Text Available Duration of nocturnal melatonin secretion, a marker of “biological night” that relates to sleep duration, is longer in winter than in summer in patients with seasonal affective disorder (SAD, but not in healthy controls. In this study of African and African American college students, we hypothesized that students who met criteria for winter SAD or subsyndromal SAD (S-SAD would report sleeping longer in winter than in summer. In addition, based on our previous observation that Africans report more “problems” with change in seasons than African Americans, we expected that the seasonal changes in sleep duration would be greater in African students than in African American students. Based on Seasonal Pattern Assessment Questionnaire (SPAQ responses, African American and African college students in Washington, D.C. (N = 575 were grouped into a winter SAD/S-SAD group or a no winter diagnosis group, and winter and summer sleep length were determined. We conducted a 2 (season × 2 (sex × 2 (ethnicity × 2 (winter diagnosis group ANCOVA on reported sleep duration, controlling for age. Contrary to our hypothesis, we found that African and African American students with winter SAD/S-SAD report sleeping longer in the summer than in the winter. No differences in seasonality of sleep were found between African and African American students. Students with winter SAD or S-SAD may need to sacrifice sleep duration in the winter, when their academic functioning/efficiency may be impaired by syndromal or subsyndromal depression, in order to meet seasonally increased academic demands.

  2. A learning progression based teaching module on the causes of seasons

    International Nuclear Information System (INIS)

    Galano, S.

    2016-01-01

    In this paper, we report about designing and validating a teaching learning module based on a learning progression and focused on the causes of seasons. An initial learning progression about the Celestial Motion big idea —causes of seasons, lunar and solar eclipse and Moon phases— was developed and validated. Existing curricula, research studies on alternative conceptions about these phenomena, and students’ answers to an open questionnaire were the starting point to develop initial learning progressions; then, a two-tier multiple-choice questionnaire was designed to validate and improve it. The questionnaire was submitted to about 300 secondary-school students whose answers were used to revise the hypothesized learning progressions. This improved version of the learning progression was used to design a module focused on the causes of seasons in which students were engaged in quantitative measurements with a photovoltaic panel to explain changes of the Sun rays’ flow on the Earth’s surface over the year. The efficacy of our module in improving students’ understanding of the phenomenon of the seasons was tested using our questionnaire as pre- and post-test.

  3. Strip Tillage and Early-Season Broadleaf Weed Control in Seeded Onion (Allium cepa

    Directory of Open Access Journals (Sweden)

    Sarah Gegner-Kazmierczak

    2016-03-01

    Full Text Available Field experiments were conducted in 2007 and 2008 near Oakes, North Dakota (ND, USA, to evaluate if strip tillage could be incorporated into a production system of seeded onion (Allium cepa to eliminate the standard use of a barley (Hordeum vulgare companion crop with conventional, full width tillage, yet support common early-season weed control programs. A split-factor design was used with tillage (conventional and strip tillage as the main plot and herbicide treatments (bromoxynil, DCPA, oxyfluorfen, and pendimethalin as sub-plots. Neither tillage nor herbicide treatments affected onion stand counts. Common lambsquarters (Chenopodium album densities were lower in strip tillage compared to conventional tillage up to three weeks after the post-emergence applied herbicides. In general, micro-rate post-emergence herbicide treatments provided greater early-season broadleaf weed control than pre-emergence herbicide treatments. Onion yield and grade did not differ among herbicide treatments because the mid-season herbicide application provided sufficient control/suppression of the early-season weed escapes that these initial weed escapes did not impact onion yield or bulb diameter. In 2007, onion in the strip tillage treatment were larger in diameter resulting in greater total and marketable yields compared to conventional tillage. Marketable onion yield was 82.1 Mg ha−1 in strip tillage and 64.9 Mg ha−1 in conventional tillage. Results indicate that strip tillage use in direct-seeded onion production was beneficial, especially when growing conditions were conducive to higher yields and that the use of strip tillage in onion may provide an alternative to using a companion crop as it did not interfere with either early-season weed management system.

  4. Seasonal changes in the physiology of male Virginia opossums (Didelphis virginiana): signs of the Dasyurid semelparity syndrome?

    Science.gov (United States)

    Woods, Henri A; Hellgren, Eric C

    2003-01-01

    Semelparity, which is multiplying once in a lifetime, is a rare reproductive strategy among mammals. Several species of the marsupial family Dasyuridae experience 100% male mortality following an intense mating period. We investigated seasonal physiological changes that may be associated with early mortality in the male Virginia opossum (Didelphis virginiana; Didelphidae) and compared these changes with those of semelparous, male dasyurids. Free-ranging male Virginia opossums (n=36) were collected during 2001 at the Oklahoma State University Cross Timbers Experimental Range. Seasonal data were collected on hematological, morphological, and helminth parameters of these individuals. We used one-way ANOVA to determine whether there were seasonal differences among means for each parameter. It appeared that male Virginia opossums experienced some physiological changes similar to those of male dasyurids exhibiting semelparity. All males collected in summer (August) were juveniles of the year. Lack of adult males in August suggests high mortality of this cohort during the breeding season. Opossum characteristics exhibiting the dasyurid semelparity syndrome included packed cell volume, adrenal mass, and helminth numbers. Minor lymphocytopenia, neutrophilia, and testosterone concentrations also were similar to semelparous dasyurids. However, a lack of change in serum cortisol concentration and body mass and dynamics in immunoglobulin protein, serum protein, and testes mass were not consistent with previous reports of semelparous dasyurid physiology. Evolutionary divergence and differences in breeding behavior between dasyurids and didelphids may be responsible for the lack of consistency between the taxa.

  5. Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland

    Directory of Open Access Journals (Sweden)

    Tineke Kraaij

    2017-08-01

    Full Text Available Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed ‘recruitment’. Factors (in decreasing order of importance affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire and fire return interval (>7 years had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2–3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting

  6. Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland.

    Science.gov (United States)

    Kraaij, Tineke; Cowling, Richard M; van Wilgen, Brian W; Rikhotso, Diba R; Difford, Mark

    2017-01-01

    Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa) where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents) of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire) fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed 'recruitment'). Factors (in decreasing order of importance) affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire) and fire return interval (>7 years) had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2-3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting that proteoid

  7. Seasonal timing of first rain storms affects rare plant population dynamics

    Science.gov (United States)

    Levine, J.M.; McEachern, A.K.; Cowan, C.

    2011-01-01

    A major challenge in forecasting the ecological consequences of climate change is understanding the relative importance of changes to mean conditions vs. changes to discrete climatic events, such as storms, frosts, or droughts. Here we show that the first major storm of the growing season strongly influences the population dynamics of three rare and endangered annual plant species in a coastal California (USA) ecosystem. In a field experiment we used moisture barriers and water addition to manipulate the timing and temperature associated with first major rains of the season. The three focal species showed two- to fivefold variation in per capita population growth rates between the different storm treatments, comparable to variation found in a prior experiment imposing eightfold differences in season-long precipitation. Variation in germination was a major demographic driver of how two of three species responded to the first rains. For one of these species, the timing of the storm was the most critical determinant of its germination, while the other showed enhanced germination with colder storm temperatures. The role of temperature was further supported by laboratory trials showing enhanced germination in cooler treatments. Our work suggests that, because of species-specific cues for demographic transitions such as germination, changes to discrete climate events may be as, if not more, important than changes to season-long variables.

  8. Soil bacterial community response to differences in agricultural management along with seasonal changes in a Mediterranean region.

    Science.gov (United States)

    Bevivino, Annamaria; Paganin, Patrizia; Bacci, Giovanni; Florio, Alessandro; Pellicer, Maite Sampedro; Papaleo, Maria Cristiana; Mengoni, Alessio; Ledda, Luigi; Fani, Renato; Benedetti, Anna; Dalmastri, Claudia

    2014-01-01

    Land-use change is considered likely to be one of main drivers of biodiversity changes in grassland ecosystems. To gain insight into the impact of land use on the underlying soil bacterial communities, we aimed at determining the effects of agricultural management, along with seasonal variations, on soil bacterial community in a Mediterranean ecosystem where different land-use and plant cover types led to the creation of a soil and vegetation gradient. A set of soils subjected to different anthropogenic impact in a typical Mediterranean landscape, dominated by Quercus suber L., was examined in spring and autumn: a natural cork-oak forest, a pasture, a managed meadow, and two vineyards (ploughed and grass covered). Land uses affected the chemical and structural composition of the most stabilised fractions of soil organic matter and reduced soil C stocks and labile organic matter at both sampling season. A significant effect of land uses on bacterial community structure as well as an interaction effect between land uses and season was revealed by the EP index. Cluster analysis of culture-dependent DGGE patterns showed a different seasonal distribution of soil bacterial populations with subgroups associated to different land uses, in agreement with culture-independent T-RFLP results. Soils subjected to low human inputs (cork-oak forest and pasture) showed a more stable bacterial community than those with high human input (vineyards and managed meadow). Phylogenetic analysis revealed the predominance of Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes phyla with differences in class composition across the site, suggesting that the microbial composition changes in response to land uses. Taken altogether, our data suggest that soil bacterial communities were seasonally distinct and exhibited compositional shifts that tracked with changes in land use and soil management. These findings may contribute to future searches for bacterial bio-indicators of soil

  9. Soil bacterial community response to differences in agricultural management along with seasonal changes in a Mediterranean region.

    Directory of Open Access Journals (Sweden)

    Annamaria Bevivino

    Full Text Available Land-use change is considered likely to be one of main drivers of biodiversity changes in grassland ecosystems. To gain insight into the impact of land use on the underlying soil bacterial communities, we aimed at determining the effects of agricultural management, along with seasonal variations, on soil bacterial community in a Mediterranean ecosystem where different land-use and plant cover types led to the creation of a soil and vegetation gradient. A set of soils subjected to different anthropogenic impact in a typical Mediterranean landscape, dominated by Quercus suber L., was examined in spring and autumn: a natural cork-oak forest, a pasture, a managed meadow, and two vineyards (ploughed and grass covered. Land uses affected the chemical and structural composition of the most stabilised fractions of soil organic matter and reduced soil C stocks and labile organic matter at both sampling season. A significant effect of land uses on bacterial community structure as well as an interaction effect between land uses and season was revealed by the EP index. Cluster analysis of culture-dependent DGGE patterns showed a different seasonal distribution of soil bacterial populations with subgroups associated to different land uses, in agreement with culture-independent T-RFLP results. Soils subjected to low human inputs (cork-oak forest and pasture showed a more stable bacterial community than those with high human input (vineyards and managed meadow. Phylogenetic analysis revealed the predominance of Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes phyla with differences in class composition across the site, suggesting that the microbial composition changes in response to land uses. Taken altogether, our data suggest that soil bacterial communities were seasonally distinct and exhibited compositional shifts that tracked with changes in land use and soil management. These findings may contribute to future searches for bacterial bio

  10. Stable isotopes in a branching coral monitor seasonal temperature variation

    International Nuclear Information System (INIS)

    Dunbar, R.B.; Wellington, G.M.

    1981-01-01

    Results are reported of 18 O composition measurements of specimens of the branching reef coral Pocillopora damicornis, which have grown in the field, while seawater temperatures were continuously recorded. It is shown that seasonal temperature changes are accurately recorded by 18 O variations in branches of this reef coral and that isotopic profiles may be used to estimate growth rates of branching corals, which lack annual density banding. The method provides a technique for high resolution palaeoclimatic reconstruction of seasonal temperature ranges and accurate estimation of rates of reef carbonate production. (U.K.)

  11. Observed changes in seasonal heat waves and warm temperature extremes in the Romanian Carpathians

    Science.gov (United States)

    Micu, Dana; Birsan, Marius-Victor; Dumitrescu, Alexandru; Cheval, Sorin

    2015-04-01

    Extreme high temperature have a large impact on environment and human activities, especially in high elevation areas particularly sensitive to the recent climate warming. The climate of the Romanian Carpathians became warmer particularly in winter, spring and summer, exibiting a significant increasing frequency of warm extremes. The paper investigates the seasonal changes in the frequency, duration and intensity of heat waves in relation to the shifts in the daily distribution of maximum temperatures over a 50-year period of meteorological observations (1961-2010). The paper uses the heat wave definition recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI) and exploits the gridded daily dataset of maximum temperature at 0.1° resolution (~10 km) developed in the framework of the CarpatClim project (www.carpatclim.eu). The seasonal changes in heat waves behavior were identified using the Mann-Kendall non-parametric trend test. The results suggest an increase in heat wave frequency and a lengthening of intervals affected by warm temperature extremes all over the study region, which are explained by the shifts in the upper (extreme) tail of the daily maximum temperature distribution in most seasons. The trends are consistent across the region and are well correlated to the positive phases of the East Atlantic Oscillation. Our results are in good agreement with the previous temperature-related studies concerning the Carpathian region. This study was realized within the framework of the project GENCLIM, financed by UEFISCDI, code PN-II 151/2014.

  12. Post-fire soil functionality and microbial community structure in a Mediterranean shrubland subjected to experimental drought.

    Science.gov (United States)

    Hinojosa, M Belén; Parra, Antonio; Laudicina, Vito Armando; Moreno, José M

    2016-12-15

    Fire may cause significant alterations in soil properties. Post-fire soil dynamics can vary depending, among other factors, on rainfall patterns. However, little is known regarding variations in response to post-fire drought. This is relevant in arid and semiarid areas with poor soils, like much of the western Mediterranean. Furthermore, climate change projections in such areas anticipate reduced precipitation and longer annual drought periods, together with an increase in fire severity and frequency. This research evaluates the effects of experimental drought after fire on soil dynamics of a Cistus-Erica shrubland (Central Spain). A replicated (n=4) field experiment was conducted in which the total rainfall and its patterns were manipulated by means of a rain-out shelters and irrigation system. The treatments were: environmental control (natural rainfall), historical control (average rainfall, 2months drought), moderate drought (25% reduction of historical control, 5months drought) and severe drought (45% reduction, 7months drought). After one growing season under these rainfall treatments, the plots were burned. One set of unburned plots under natural rainfall served as an additional control. Soils were collected seasonally. Fire increased soil P and N availability. Post-fire drought treatments reduced available soil P but increased N concentration (mainly nitrate). Fire reduced available K irrespective of drought treatments. Fire reduced enzyme activities and carbon mineralization rate, a reduction that was higher in post-fire drought-treated soils. Fire decreased soil microbial biomass and the proportion of fungi, while that of actinomycetes increased. Post-fire drought decreased soil total microbial biomass and fungi, with bacteria becoming more abundant. Our results support that increasing drought after fire could compromise the resilience of Mediterranean ecosystems to fire. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Seasonal changes in cell mediated immune responses to soluble Plasmodium falciparum antigens in children with haemoglobin AA and haemoglobin AS

    DEFF Research Database (Denmark)

    Abu-Zeid, Y A; Abdulhadi, N H; Theander, T G

    1992-01-01

    of tuberculin (PPD). The lymphoproliferative responses to SPAg of the paired PBMC samples showed 2 distinct seasonal changes in relation to the haemoglobin phenotype. In HbAA children, the lymphoproliferative responses to SPAg were suppressed during the malaria season. In contrast, they were enhanced in Hb......AS children during the malaria season. No distinct seasonal change in the response to PPD was found in relation to the haemoglobin phenotype. The study points to the role of the sickle cell trait in modulating the cellular immune responses to falciparum malaria....

  14. Seasonal variations in shallow Alaska seismicity and stress modulation from GRACE derived hydrological loading

    Science.gov (United States)

    Johnson, C. W.; Fu, Y.; Burgmann, R.

    2017-12-01

    Shallow (≤50 km), low magnitude (M≥2.0) seismicity in southern Alaska is examined for seasonal variations during the annual hydrological cycle. The seismicity is declustered with a spatio-temporal epidemic type aftershock sequence (ETAS) model. The removal of aftershock sequences allows detailed investigation of seismicity rate changes, as water and ice loads modulate crustal stresses throughout the year. The GRACE surface loads are obtained from the JPL mass concentration blocks (mascons) global land and ocean solutions. The data product is smoothed with a 9˚ Gaussian filter and interpolated on a 25 km grid. To inform the surface loading model, the global solutions are limited to the region from -160˚ to -120˚ and 50˚ to 70˚. The stress changes are calculated using a 1D spherical layered earth model at depth intervals of 10 km from 10 - 50 km in the study region. To evaluate the induced seasonal stresses, we use >30 years of earthquake focal mechanisms to constrain the background stress field orientation and assess the stress change with respect to the principal stress orientation. The background stress field is assumed to control the preferred orientation of faulting, and stress field perturbations are expected to increase or decrease seismicity. The number of excess earthquakes is calculated with respect to the background seismicity rates. Here, we present preliminary results for the shallow seismicity variations and quantify the seasonal stresses associated with changes in hydrological loading.

  15. Different Patterns of Changes in the Dry Season Diameter at Breast Height of Dominant and Evergreen Tree Species in a Mature Subtropical Forest in South China

    Institute of Scientific and Technical Information of China (English)

    Jun-Hua Yan; Guo-Yi Zhou; De-Qiang Zhang; Xu-Li Tang; Xu Wang

    2006-01-01

    Information on changes in diameter at breast height (DBH) is important for net primary production (NPP)estimates, timing of forest inventory, and forest management. In the present study, patterns of DBH change were measured under field conditions during the dry season for three dominant and native tree species in a monsoon evergreen broad-leaved forest in the Dinghushan Biosphere Reserve. For each tree species,different patterns of DBH change were observed. In the case of the fast-growing tree species Castanopsis chinensis Hance, large diurnal fluctuations occur, with a peak DBH in the early morning (around 05:00 h) that decreases to a minimum by about 14:00 h. Both Schima superba Gardn. et Chemp and Cryptocarya chinensis (Hance) Hemsl. exhibited less diurnal swelling and shrinkage. Diurnal fluctuations for these species were observed on a few occasions over the period of observation. Graphical comparisons and statistical analysis of changes in DBH with meteorological variables indicate that for different trees, the different changes in DBH observed responded to different meteorological variables. Large stem changes were found to occur for Ca. chinensis trees that were associated with variations in solar radiation. However, both S. superba and Cr. chinensis were found to be less sensitive to solar radiation. Changes in the DBH of these two species were found to be controlled mainly by soil temperature and soil moisture. During the later dry season, with a lower soil temperature and soil moisture, all three tree species stopped growing and only negligible shrinkage, expansion, or fluctuation occurred, suggesting that the optimum time to measure tree growth in the Dinghushan Biosphere Reserve is the later dry season.

  16. Dynamic changes in left ventricular mass and in fat-free mass in top-level athletes during the competitive season.

    Science.gov (United States)

    D'Ascenzi, Flavio; Pelliccia, Antonio; Cameli, Matteo; Lisi, Matteo; Natali, Benedetta Maria; Focardi, Marta; Giorgi, Andrea; D'Urbano, Giorgio; Causarano, Andrea; Bonifazi, Marco; Mondillo, Sergio

    2015-01-01

    Previous cross-sectional studies have demonstrated that fat-free mass (FFM) is an important determinant of left ventricular mass (LVM) in athletes. However, cross-sectional investigations have not the ability to detect the dynamic adaptation occurring with training. We hypothesized that LVM adapts concurrently with the increase of FFM induced by exercise conditioning. We sought to study the relationship between the variations of LVM and of FFM occurring in top-level soccer players during the season. Twenty-three male top-level athletes were recruited. LVM was assessed by echocardiography and FFM by dual-energy X-ray absorptiometry. Serial measurements were performed pre-season, after 1 month, at mid- and end-season, and after 2 months of detraining. LVM significantly increased at mid-season versus pre-season values, reaching the highest value at the end of the season (p FFM significantly increased (p FFM (R = 0.36, p = 0.005; R = 0.35, p = 0.005, respectively). When ΔLVM index was set as dependent variable, the only independent predictor was ΔFFM (R = 0.87, p = 0.002). Changes in LVM occur in close association with changes in FFM, suggesting that the left ventricle adapts concurrently with the increase of the metabolically active tissue induced by training, i.e. the FFM. Therefore, the dynamic changes in FFM and LVM may reflect a physiological adaptation induced by intensive training. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  17. Spatial Analysis to Determine Paddy Field Changes in Indonesia: A Case Study in Suburban Areas of Jakarta

    Science.gov (United States)

    Putri Utami, Nadia; Ahamed, Tofael

    2018-05-01

    Karawang, a suburban area of Greater Jakarta, is known as the second largest rice-producing region in West Java, Indonesia. However, expansion of urban sprawl and industrial area from Greater Jakarta have created rapid agricultural land use/cover changes, especially paddy field, in Karawang. This study analyzed the land use/cover changes of paddy field from 2000 to 2016. Landsat 4-5 TM and Landsat 8 OLI/TIRS images were acquired from USGS Earth Explorer, UTM zone 48 south. Satellite image pre-processing, ground truth data collection, supervised maximum likelihood classifications, and Post-Classification Comparison (PCC) were performed in ArcGIS 10.3®. It was observed between 2000 and 2016, urban area increased 4.46% (8530 ha) from initial area of 10,004 ha. Meanwhile paddy field decreased 3.18% (6091 ha) from initial area of 115,720 ha. The spatial analysis showed that paddy field in the fringe of urban area are more susceptible for changes.

  18. Where the wild things are: Seasonal variation in caribou distribution in relation to climate change

    Directory of Open Access Journals (Sweden)

    Philippa McNeil

    2005-05-01

    Full Text Available In this study, we develop a method to analyse the relationships between seasonal caribou distribution and climate, to estimate how climatic conditions affect interactions between humans and caribou, and ultimately to predict patterns of distribution relative to climate change. Satellite locations for the Porcupine (Rangifer tarandus granti and Bathurst (R. t. groenlandicus caribou herds were analysed for eight ecologically-defined seasons. For each season, two levels of a key environmental factor influencing caribou distribution were identified, as well as the best climate data available to indicate the factor's annual state. Satellite locations were grouped according to the relevant combination of season and environmental factor. Caribou distributions were compared for opposing environmental factors; this comparison was undertaken relative to hunting access for the Porcupine Herd and relative to exposure to mining activity for the Bathurst Herd. Expected climate trends suggest an overall increase in access to Porcupine caribou for Aklavik (NWT hunters during the winter and rut seasons, for Venetie (Alaska hunters during midsummer and fall migration and for Arctic Village (Alaska during midsummer. Arctic Village may experience reduced availability with early snowfalls in the fall, but we expect there to be little directional shift in the spring migration patterns. For the Bathurst Herd, we expect that fewer caribou would be exposed to the mines during the winter, while more caribou would be exposed to the combined Ekati and Diavik mining zone in the early summer and to the Lupin-Jericho mining zone during the fall migration. If changes in climate cause an increased presence of caribou in the mining sites, monitoring and mitigation measures may need to be intensified.

  19. SEASONAL MARKETING: STRATEGIES USING THE CALENDAR

    OpenAIRE

    Dr Anil Sardana; Dr PoojaTalwar; Shruti Gulati

    2018-01-01

    In this ever-dynamic world, the only thing that is constant is change. Change when happens, applies to all; then why should marketing remain the same? Each year is a witness to various seasons, and each season requires separate marketing efforts to be carried out differently. Seasonal marketing thus helps to capitalise on the varied demand through varied marketing. Every season requires special efforts and hence leads to different sales.

  20. Post operation: The changing characteristics of nuclear fuel cycle costs

    International Nuclear Information System (INIS)

    Frank, F.J.

    1986-01-01

    Fundamental changes have occurred in the nuclear fuel cycle. These changes forged by market forces, legislative action, and regulatory climate appear to be a long term characteristic of the nuclear fuel cycle. The nature of these changes and the resulting emerging importance of post-operation and its impact on fuel cycle costs are examined

  1. Growing Season Conditions Mediate the Dependence of Aspen on Redistributed Snow Under Climate Change.

    Science.gov (United States)

    Soderquist, B.; Kavanagh, K.; Link, T. E.; Seyfried, M. S.; Strand, E. K.

    2016-12-01

    Precipitation regimes in many semiarid ecosystems are becoming increasingly dominated by winter rainfall as a result of climate change. Across these regions, snowpack plays a vital role in the distribution and timing of soil moisture availability. Rising temperatures will result in a more uniform distribution of soil moisture, advanced spring phenology, and prolonged growing seasons. Productive and wide ranging tree species like aspen, Populus tremuloides, may experience increased vulnerability to drought and mortality resulting from both reduced snowpack and increased evaporative demand during the growing season. We simulated the net primary production (NPP) of aspen stands spanning the rain:snow transition zone in the Reynolds Creek Critical Zone Observatory (RCCZO) in southwest Idaho, USA. Within the RCCZO, the total amount of precipitation has remained unchanged over the past 50 years, however the percentage of the precipitation falling as snow has declined by approximately 4% per decade at mid-elevation sites. The biogeochemical process model Biome-BGC was used to simulate aspen NPP at three stands located directly below snowdrifts that provide melt water late into the spring. After adjusting precipitation inputs to account for the redistribution of snow, we assessed climate change impacts on future aspen productivity. Mid-century (2046-2065) aspen NPP was simulated using temperature projections from a multi-model average under high emission conditions using the Multivariate Adaptive Constructed Analogs (MACA) data set. While climate change simulations indicated over a 20% decrease in annual NPP for some years, NPP rates for other mid-century years remained relatively unchanged due to variations in growing season conditions. Mid-century years with the largest decreases in NPP typically showed increased spring transpiration rates resulting from earlier leaf flush combined with warmer spring conditions. During these years, the onset of drought stress occurred

  2. Neck Collar with Mild Jugular Vein Compression Ameliorates Brain Activation Changes during a Working Memory Task after a Season of High School Football.

    Science.gov (United States)

    Yuan, Weihong; Leach, James; Maloney, Thomas; Altaye, Mekibib; Smith, David; Gubanich, Paul J; Barber Foss, Kim D; Thomas, Staci; DiCesare, Christopher A; Kiefer, Adam W; Myer, Gregory D

    2017-08-15

    Emerging evidence indicates that repetitive head impacts, even at a sub-concussive level, may result in exacerbated or prolonged neurological deficits in athletes. This study aimed to: 1) quantify the effect of repetitive head impacts on the alteration of neuronal activity based on functional magnetic resonance imaging (fMRI) of working memory after a high school football season; and 2) determine whether a neck collar that applies mild jugular vein compression designed to reduce brain energy absorption in head impact through "slosh" mitigation can ameliorate the altered fMRI activation during a working memory task. Participants were recruited from local high school football teams with 27 and 25 athletes assigned to the non-collar and collar group, respectively. A standard N-Back task was used to engage working memory in the fMRI at both pre- and post-season. The two study groups experienced similar head impact frequency and magnitude during the season (all p > 0.05). fMRI blood oxygen level dependent (BOLD) signal response (a reflection of the neuronal activity level) during the working memory task increased significantly from pre- to post-season in the non-collar group (corrected p working memory related brain activity, as well as a potential protective effect that resulted from the use of the purported brain slosh reducing neck collar in contact sports.

  3. A framework for examining climate-driven changes to the seasonality and geographical range of coastal pathogens and harmful algae

    Directory of Open Access Journals (Sweden)

    John Jacobs

    2015-01-01

    Full Text Available Climate change is expected to alter coastal ecosystems in ways which may have predictable consequences for the seasonality and geographical distribution of human pathogens and harmful algae. Here we demonstrate relatively simple approaches for evaluating the risk of occurrence of pathogenic bacteria in the genus Vibrio and outbreaks of toxin-producing harmful algae in the genus Alexandrium, with estimates of uncertainty, in U.S. coastal waters under future climate change scenarios through the end of the 21st century. One approach forces empirical models of growth, abundance and the probability of occurrence of the pathogens and algae at specific locations in the Chesapeake Bay and Puget Sound with ensembles of statistically downscaled climate model projections to produce first order assessments of changes in seasonality. In all of the case studies examined, the seasonal window of occurrence for Vibrio and Alexandrium broadened, indicating longer annual periods of time when there is increased risk for outbreaks. A second approach uses climate model projections coupled with GIS to identify the potential for geographic range shifts for Vibrio spp. in the coastal waters of Alaska. These two approaches could be applied to other coastal pathogens that have climate sensitive drivers to investigate potential changes to the risk of outbreaks in both time (seasonality and space (geographical distribution under future climate change scenarios.

  4. Understanding Seasonal Changes to Improve Good Practices in Livestock Management

    Directory of Open Access Journals (Sweden)

    Francesco Martelli

    2018-06-01

    Full Text Available Background and Aim: Food quality control techniques based on process control methods are increasingly adopted in livestock production systems to fulfill increasing market's expectations toward competitiveness and issues linked to One Health pillars (environment, animal, and human health. Control Charts allow monitoring and systematic investigation of sources of variability in dairy production parameters. These parameters, however, may be affected by seasonal variations that render impractical, biased or ineffective the use statistical control charts. A possible approach to this problem is to adapt seasonal adjustment methods used for the analysis of economic and demographic seasonal time series. The aim of the present work is to evaluate a seasonal decomposition technique called X-11 on milk parameters routinely collected also in small farms (fat, protein, and lactose content, solids-not-fat, freezing point, somatic cell count, total bacterial count and to test the efficacy of different seasonal removal methods to improve the effectiveness of statistical control charting.Method: Data collection was carried out for 3 years on routinely monitored bulk tank milk parameters of a small farm. Seasonality presence was statistically assessed on milk parameters and, for those parameters showing seasonality, control charts for individuals were applied on raw data, on X-11 seasonally adjusted data, and on data smoothed with a symmetric moving average filter. Correlation of seasonally influenced parameters with daily mean temperature was investigated.Results: Presence of seasonality in milk parameters was statistically assessed for fat, protein, and solids-non-fat components. The X-11 seasonally-adjusted control charts showed a reduced number of violations (false alarms with respect to non-seasonally adjusted control chart (from 5 to 1 violation for fat, from 17 to 1 violation for protein, and from 9 to none violation for solids-non-fat.. This result was

  5. Rapid change of field line connectivity and reconnection in stochastic magnetic fields

    International Nuclear Information System (INIS)

    Huang, Yi-Min; Bhattacharjee, A.; Boozer, Allen H.

    2014-01-01

    Magnetic fields without a direction of continuous symmetry have the generic feature that neighboring field lines exponentiate away from each other and become stochastic, and hence the ideal constraint of preserving magnetic field line connectivity becomes exponentially sensitive to small deviations from ideal Ohm's law. The idea of breaking field line connectivity by stochasticity as a mechanism for fast reconnection is tested with numerical simulations based on reduced magnetohydrodynamics equations with a strong guide field line-tied to two perfectly conducting end plates. Starting from an ideally stable force-free equilibrium, the system is allowed to undergo resistive relaxation. Two distinct phases are found in the process of resistive relaxation. During the quasi-static phase, rapid change of field line connectivity and strong induced flow are found in regions of high field line exponentiation. However, although the field line connectivity of individual field lines can change rapidly, the overall pattern of field line mapping appears to deform gradually. From this perspective, field line exponentiation appears to cause enhanced diffusion rather than reconnection. In some cases, resistive quasi-static evolution can cause the ideally stable initial equilibrium to cross a stability threshold, leading to formation of intense current filaments and rapid change of field line mapping into a qualitatively different pattern. It is in this onset phase that the change of field line connectivity is more appropriately designated as magnetic reconnection. Our results show that rapid change of field line connectivity appears to be a necessary, but not a sufficient condition for fast reconnection.

  6. Seasonal changes in meat weight and biochemical composition in the Black Clam Villorita cyprinoides (Grey)

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Parulekar, A.H.; Matondkar, S.G.P.

    Seasonal changes in meat weight and biochemical composition are associated with reproduction, storage and utilization of reserves. The main period of increase in biochemical constituents corresponds to gametogenesis and maturation of gonads just...

  7. Response of seasonal soil freeze depth to climate change across China

    Science.gov (United States)

    Peng, Xiaoqing; Zhang, Tingjun; Frauenfeld, Oliver W.; Wang, Kang; Cao, Bin; Zhong, Xinyue; Su, Hang; Mu, Cuicui

    2017-05-01

    The response of seasonal soil freeze depth to climate change has repercussions for the surface energy and water balance, ecosystems, the carbon cycle, and soil nutrient exchange. Despite its importance, the response of soil freeze depth to climate change is largely unknown. This study employs the Stefan solution and observations from 845 meteorological stations to investigate the response of variations in soil freeze depth to climate change across China. Observations include daily air temperatures, daily soil temperatures at various depths, mean monthly gridded air temperatures, and the normalized difference vegetation index. Results show that soil freeze depth decreased significantly at a rate of -0.18 ± 0.03 cm yr-1, resulting in a net decrease of 8.05 ± 1.5 cm over 1967-2012 across China. On the regional scale, soil freeze depth decreases varied between 0.0 and 0.4 cm yr-1 in most parts of China during 1950-2009. By investigating potential climatic and environmental driving factors of soil freeze depth variability, we find that mean annual air temperature and ground surface temperature, air thawing index, ground surface thawing index, and vegetation growth are all negatively associated with soil freeze depth. Changes in snow depth are not correlated with soil freeze depth. Air and ground surface freezing indices are positively correlated with soil freeze depth. Comparing these potential driving factors of soil freeze depth, we find that freezing index and vegetation growth are more strongly correlated with soil freeze depth, while snow depth is not significant. We conclude that air temperature increases are responsible for the decrease in seasonal freeze depth. These results are important for understanding the soil freeze-thaw dynamics and the impacts of soil freeze depth on ecosystem and hydrological process.

  8. Post-adolescent developmental changes in cortical complexity.

    Science.gov (United States)

    Sandu, Anca-Larisa; Izard, Edouard; Specht, Karsten; Beneventi, Harald; Lundervold, Arvid; Ystad, Martin

    2014-11-27

    Post-adolescence is known to be a period of general maturation and development in the human brain. In brain imaging, volumetric and morphologic cortical grey-matter changes can easily be assessed, but the analysis of cortical complexity seems to have been broadly neglected for this age interval. Magnetic resonance imaging (MRI) was used to acquire structural brain images. The study involved 17 adolescents (mean age 14.1 ± 0.27, 11 girls) who were compared with 14 young adults (mean age 24.24 ± 2.76, 7 women) for measures of brain complexity (fractal dimension--FD), grey matter (GM) volume and surface-area of cortical ribbon. FD was calculated using box-counting and Minkowski-Bouligand methods; FD and GM volume were measured for the whole brain, each hemisphere and lobes: frontal, occipital, parietal and temporal. The results show that the adults have a lower cortical complexity than the adolescents, which was significant for whole brain, left and right hemisphere, frontal and parietal lobes for both genders; and only for males in left temporal lobe. The GM volume was smaller in men than in boys for almost all measurements, and smaller in women than in girls just for right parietal lobe. A significant Pearson correlation was found between FD and GM volume for whole brain and each hemisphere in both genders. The decrease of the GM surface-area was significant in post-adolescence for males, not for females. During post-adolescence there are common changes in cortical complexity in the same regions for both genders, but there are also gender specific changes in some cortical areas. The sex differences from different cortical measurements (FD, GM volume and surface-area of cortical ribbon) could suggest a maturation delay in specific brain regions for each gender in relation to the other and might be explained through the functional role of the corresponding regions reflected in gender difference of developed abilities.

  9. Field investigation to assess nutrient emission from paddy field to surface water in river catchment

    Science.gov (United States)

    Kogure, Kanami; Aichi, Masaatsu; Zessner, Matthias

    2015-04-01

    In order to maintain good river environment, it is remarkably important to understand and to control nutrient behavior such as Nitrogen and Phosphorus. Our former research dealing with nutrient emission analysis in the Tone River basin area in Japan, in addition to urban and industrial waste water, nutrient emission from agricultural activity is dominant pollution source into the river system. Japanese style agriculture produces large amount of rice and paddy field occupies large areas in Japanese river basin areas. While paddy field can deteriorate river water quality by outflow of fertilizer, it is also suggested that paddy field has water purification function. As we carried out investigation in the Tone River Basin area, data were obtained which dissolved nitrogen concentration is lower in discharging water from paddy field than inflowing water into the field. Regarding to nutrient emission impact from paddy field, sufficient data are required to discuss quantitatively seasonal change of material behavior including flooding season and dry season, difference of climate condition, soil type, and rice species, to evaluate year round comprehensive impact from paddy field to the river system. In this research, field survey in paddy field and data collection relating rice production were carried out as a preliminary investigation to assess how Japanese style paddy field contributes year round on surface water quality. Study sites are three paddy fields located in upper reach of the Tone River basin area. The fields are flooded from June to September. In 2014, field investigations were carried out three times in flooding period and twice in dry period. To understand characteristics of each paddy field and seasonal tendency accompanying weather of agricultural event, short term investigations were conducted and we prepare for further long term investigation. Each study site has irrigation water inflow and outflow. Two sites have tile drainage system under the field and

  10. Agricultural crops and soil treatment impacts on the daily and seasonal dynamics of CO2 fluxes in the field agroecosystems at the Central region of Russia

    Science.gov (United States)

    Mazirov, Ilya; Vasenev, Ivan; Meshalkina, Joulia; Yaroslavtsev, Alexis; Berezovskiy, Egor; Djancharov, Turmusbek

    2015-04-01

    The problem of greenhouse gases' concentrations increasing becomes more and more important due to global changes issues. The main component of greenhouse gases is carbon dioxide. The researches focused on its fluxes in natural and anthropogenic modified landscapes can help in this problem solution. Our research has been done with support of the RF Government grants # 11.G34.31.0079 and # 14.120.14.4266 and of FP7 Grant # 603542 LUC4C in the representative for Central Region of Russia field agroecosystems at the Precision Farming Experimental Field of Russian Timiryazev State Agrarian University with cultivated sod podzoluvisols, barley and oats - vetch grass mix (Moscow station of the RusFluxNet). The daily and seasonal dynamics of the carbon dioxide have been studied at the ecosystem level by the Eddy covariance method (2 stations) and at the soil level by the exposition chamber method (40 chambers) with mobile infra red gas analyzer (Li-Cor 820). The primary Eddy covariance monitoring data on CO2 fluxes and water vapor have been processed by EddyPro software developed by LI-COR Biosciences. According to the two-year monitoring data the daily CO2 sink during the vegetation season is usually approximately two times higher than its emission at night. Seasonal CO2 fluxes comparative stabilization has been fixed in case the plants height around 10-12 cm and it usually persist until the wax ripeness phase. There is strong dependence between the soil CO2 emission and the air temperature with the correlation coefficient 0.86 in average (due to strong input of the soil thin top functional subhorizon), but it drops essentially at the end of the season - till 0.38. The soil moisture impact on CO2 fluxes dynamics was less, with negative correlation at the end of the season. High daily dynamics of CO2 fluxes determines the protocol requirements for seasonal soil monitoring investigation with less limitation at the end of the season. The accumulated monitoring data will be

  11. The Different Western Perception of the Oriental Moor in the Renaissance and the Twentieth Century: Shakespeare's Othello and Tayeb Salih's Season of Migration to the North: A Post-Colonial Critique

    Directory of Open Access Journals (Sweden)

    Hussein A. Alhawamdeh

    2013-05-01

    Full Text Available This paper comparatively explores the different experience of the Muslim Orient - namely, Othello in Shakespeare's Othello (1604 and Mustafa Saeed and the narrator in Salih's Season of Migration to the North (1966 - in the West. It aims at relocating the transformation of the discourse of Orientalism from Renaissance, as represented by Shakespeare's Othello, to the post-eighteenth century, as represented by Salih's Season of Migration to the North. By contrasting the West and the Crescent, from power relations' vantage, this study highlights the historical difference of the western perception of the Orient from a colonizer, liberator, and guide to the West, as in Shakespeare's Othello, to a colonized subject, as in the characters of Mustafa Saeed and the narrator in Season of Migration. This paper bridges the gap left by modern scholarship which either focuses only on applying post-colonial theory on Salih's novel or neglects its resonance to Shakespeare's Othello in terms of power relations' vantage. Salih's novel laments, rather than deconstructs, the Renaissance Shakespearean powerful Moor, as represented by Othello in Shakespeare's Othello.

  12. Seasonality in communication and collective decision-making in ants.

    Science.gov (United States)

    Stroeymeyt, N; Jordan, C; Mayer, G; Hovsepian, S; Giurfa, M; Franks, N R

    2014-04-07

    The ability of animals to adjust their behaviour according to seasonal changes in their ecology is crucial for their fitness. Eusocial insects display strong collective behavioural seasonality, yet the mechanisms underlying such changes are poorly understood. We show that nest preference by emigrating Temnothorax albipennis ant colonies is influenced by a season-specific modulatory pheromone that may help tune decision-making according to seasonal constraints. The modulatory pheromone triggers aversion towards low-quality nests and enhances colony cohesion in summer and autumn, but not after overwintering-in agreement with reports that field colonies split in spring and reunite in summer. Interestingly, we show that the pheromone acts by downgrading the perceived value of marked nests by informed and naive individuals. This contrasts with theories of collective intelligence, stating that accurate collective decision-making requires independent evaluation of options by individuals. The violation of independence highlighted here was accordingly shown to increase error rate during emigrations. However, this is counterbalanced by enhanced cohesion and the transmission of valuable information through the colony. Our results support recent claims that optimal decisions are not necessarily those that maximize accuracy. Other criteria-such as cohesion or reward rate-may be more relevant in animal decision-making.

  13. Relationships between aquatic vegetation and water turbidity: A field survey across seasons and spatial scales

    OpenAIRE

    Austin, ?sa N.; Hansen, Joakim P.; Donadi, Serena; Ekl?f, Johan S.

    2017-01-01

    Field surveys often show that high water turbidity limits cover of aquatic vegetation, while many small-scale experiments show that vegetation can reduce turbidity by decreasing water flow, stabilizing sediments, and competing with phytoplankton for nutrients. Here we bridged these two views by exploring the direction and strength of causal relationships between aquatic vegetation and turbidity across seasons (spring and late summer) and spatial scales (local and regional), using causal model...

  14. Seasonal changes in plant-water relations influence patterns of leaf display in Miombo woodlands: evidence of water conservative strategies.

    Science.gov (United States)

    Vinya, Royd; Malhi, Yadvinder; Brown, Nick D; Fisher, Joshua B; Brodribb, Timothy; Aragão, Luiz E O C

    2018-06-15

    Water availability has frequently been linked to seasonal leaf display in seasonally dry ecosystems, but there have been few ecohydrological investigations of this link. Miombo woodland is a dominant seasonally dry tropical forest ecosystem type in southern Africa; however, there are few data on the relationship between seasonal dynamics in plant-water relations and patterns of leaf display for Miombo woodland. Here we investigate this relationship among nine key Miombo woodland tree species differing in drought tolerance ability and leaf phenology. Results of this study showed that seasonal patterns of leaf phenology varied significantly with seasonal changes in stem water relations among the nine species. Leaf shedding coincided with the attainment of seasonal minimum stem water potential. Leaf flush occurred following xylem rehydration at the peak of the dry season suggesting that endogenous plant factors play a pivotal role in seasonal leaf display in this forest type. Drought-tolerant deciduous species suffered significantly higher seasonal losses in xylem hydraulic conductivity than the drought-intolerant semi-evergreen tree species (P water stress in seasonally dry tropical forests selects for water conservative traits that protect the vulnerable xylem transport system. Therefore, seasonal rhythms in xylem transport dictate patterns of leaf display in seasonally dry tropical forests.

  15. Modeling pollen time series using seasonal-trend decomposition procedure based on LOESS smoothing.

    Science.gov (United States)

    Rojo, Jesús; Rivero, Rosario; Romero-Morte, Jorge; Fernández-González, Federico; Pérez-Badia, Rosa

    2017-02-01

    Analysis of airborne pollen concentrations provides valuable information on plant phenology and is thus a useful tool in agriculture-for predicting harvests in crops such as the olive and for deciding when to apply phytosanitary treatments-as well as in medicine and the environmental sciences. Variations in airborne pollen concentrations, moreover, are indicators of changing plant life cycles. By modeling pollen time series, we can not only identify the variables influencing pollen levels but also predict future pollen concentrations. In this study, airborne pollen time series were modeled using a seasonal-trend decomposition procedure based on LOcally wEighted Scatterplot Smoothing (LOESS) smoothing (STL). The data series-daily Poaceae pollen concentrations over the period 2006-2014-was broken up into seasonal and residual (stochastic) components. The seasonal component was compared with data on Poaceae flowering phenology obtained by field sampling. Residuals were fitted to a model generated from daily temperature and rainfall values, and daily pollen concentrations, using partial least squares regression (PLSR). This method was then applied to predict daily pollen concentrations for 2014 (independent validation data) using results for the seasonal component of the time series and estimates of the residual component for the period 2006-2013. Correlation between predicted and observed values was r = 0.79 (correlation coefficient) for the pre-peak period (i.e., the period prior to the peak pollen concentration) and r = 0.63 for the post-peak period. Separate analysis of each of the components of the pollen data series enables the sources of variability to be identified more accurately than by analysis of the original non-decomposed data series, and for this reason, this procedure has proved to be a suitable technique for analyzing the main environmental factors influencing airborne pollen concentrations.

  16. Seasonal migrations, body temperature fluctuations, and infection dynamics in adult amphibians

    Directory of Open Access Journals (Sweden)

    David R. Daversa

    2018-05-01

    Full Text Available Risks of parasitism vary over time, with infection prevalence often fluctuating with seasonal changes in the annual cycle. Identifying the biological mechanisms underlying seasonality in infection can enable better prediction and prevention of future infection peaks. Obtaining longitudinal data on individual infections and traits across seasons throughout the annual cycle is perhaps the most effective means of achieving this aim, yet few studies have obtained such information for wildlife. Here, we tracked spiny common toads (Bufo spinosus within and across annual cycles to assess seasonal variation in movement, body temperatures and infection from the fungal parasite, Batrachochytrium dendrobatidis (Bd. Across annual cycles, toads did not consistently sustain infections but instead gained and lost infections from year to year. Radio-tracking showed that infected toads lose infections during post-breeding migrations, and no toads contracted infection following migration, which may be one explanation for the inter-annual variability in Bd infections. We also found pronounced seasonal variation in toad body temperatures. Body temperatures approached 0 °C during winter hibernation but remained largely within the thermal tolerance range of Bd. These findings provide direct documentation of migratory recovery (i.e., loss of infection during migration and escape in a wild population. The body temperature reductions that we observed during hibernation warrant further consideration into the role that this period plays in seasonal Bd dynamics.

  17. Monitoring start of season in Alaska with GLOBE, AVHRR, and MODIS data

    Science.gov (United States)

    Robin, Jessica; Dubayah, Ralph; Sparrow, Elena; Levine, Elissa

    2008-03-01

    This work evaluates whether continuity between Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) normalized difference vegetation index (NDVI) is achievable for monitoring phenological changes in Alaska. This work also evaluates whether NDVI can detect changes in start of the growing season (SOS) in this region. Six quadratic regression models with NDVI as a function of accumulated growing degree days (AGDD) were developed from 2001 through 2004 AVHRR and MODIS NDVI data sets for urban, mixed, and forested land covers. Model parameters determined NDVI values for start of the observational period as well as peak and length of the growing season. NDVI values for start of the growing season were determined from the model equations and field observations of SOS made by GLOBE students and researchers at University of Alaska Fairbanks. AGDD was computed from daily air temperature. AVHRR and MODIS models were significantly different from one another with differences in the start of the observational season as well as start, peak, and length of the growing season. Furthermore, AGDD for SOS was significantly lower during the 1990s than the 1980s. NDVI values at SOS did not detect this change. There are limitations with using NDVI to monitor phenological changes in these regions because of snow, the large extent of conifers, and clouds, which restrict the composite period. In addition, differing processing and spectral characteristics restrict continuity between AVHRR and MODIS NDVI data sets.

  18. Changes in Inmates’ Substance Use and Dependence From Pre-Incarceration to One Year Post-Release

    Science.gov (United States)

    Tangney, June P.; Folk, Johanna B.; Graham, David M.; Stuewig, Jeffrey B.; Blalock, Daniel V.; Salatino, Andrew; Blasko, Brandy B.; Moore, Kelly E.

    2016-01-01

    Purpose To assess changes in inmates’ misuse of substances from pre- to post-incarceration. Methods In Study 1, professionals (n = 162) and laypersons (n = 50) predicted how jail inmates’ substance misuse would change from pre-incarceration to post-release. In Study 2, a longitudinal study of 305 jail inmates, we examined actual changes in substance use and dependence from pre-incarceration to the first year post-incarceration, as well as whether changes varied as a function of demographic, criminal justice, treatment, and personality factors. Results Professionals and laypersons predicted little change in substance misuse whereas, in fact, inmates’ frequency of substance use and dependence decreased substantially from pre-incarceration to post-release. Sharper decreases were observed for inmates who were female, younger, more educated, serving longer sentences, enrolled in substance abuse treatment, high in shame-proneness, and low in criminogenic thinking. Race, first time incarceration, transfer to other correctional facilities, mandated community supervision (probation), and guilt-proneness did not predict changes in substance use or dependence. Conclusions Although substance misuse decreased, this remains a population high in need of substance abuse treatment both upon arrest and at one year post-incarceration; 60% of former inmates met at least one DSM-IV criterion for substance dependence at one year post-release. PMID:27458324

  19. GPM Ground Validation: Pre to Post-Launch Era

    Science.gov (United States)

    Petersen, Walt; Skofronick-Jackson, Gail; Huffman, George

    2015-04-01

    NASA GPM Ground Validation (GV) activities have transitioned from the pre to post-launch era. Prior to launch direct validation networks and associated partner institutions were identified world-wide, covering a plethora of precipitation regimes. In the U.S. direct GV efforts focused on use of new operational products such as the NOAA Multi-Radar Multi-Sensor suite (MRMS) for TRMM validation and GPM radiometer algorithm database development. In the post-launch, MRMS products including precipitation rate, accumulation, types and data quality are being routinely generated to facilitate statistical GV of instantaneous (e.g., Level II orbit) and merged (e.g., IMERG) GPM products. Toward assessing precipitation column impacts on product uncertainties, range-gate to pixel-level validation of both Dual-Frequency Precipitation Radar (DPR) and GPM microwave imager data are performed using GPM Validation Network (VN) ground radar and satellite data processing software. VN software ingests quality-controlled volumetric radar datasets and geo-matches those data to coincident DPR and radiometer level-II data. When combined MRMS and VN datasets enable more comprehensive interpretation of both ground and satellite-based estimation uncertainties. To support physical validation efforts eight (one) field campaigns have been conducted in the pre (post) launch era. The campaigns span regimes from northern latitude cold-season snow to warm tropical rain. Most recently the Integrated Precipitation and Hydrology Experiment (IPHEx) took place in the mountains of North Carolina and involved combined airborne and ground-based measurements of orographic precipitation and hydrologic processes underneath the GPM Core satellite. One more U.S. GV field campaign (OLYMPEX) is planned for late 2015 and will address cold-season precipitation estimation, process and hydrology in the orographic and oceanic domains of western Washington State. Finally, continuous direct and physical validation

  20. Seasonal and Downslope Changes in the Pore Water Geochemistry of Tundra Soils Near Nome, Alaska

    Science.gov (United States)

    Philben, M. J.; Zheng, J.; Wullschleger, S. D.; Graham, D. E.; Gu, B.

    2017-12-01

    Thawing permafrost is exposing vast stores of organic matter to decomposition in previously frozen tundra soils. In low-relief and poorly drained areas, the complexity of microbial metabolism under anaerobic conditions complicates the prediction of resulting CO2 and CH4 emissions. To improve this understanding, we investigated the dissolved gas and major ion concentrations and DOM composition in depth profiles of soil pore water collected from the Teller Road site near Nome, AK, as part of the Next Generation Ecosystem Experiment (NGEE)-Arctic. Pathways of anaerobic organic matter degradation were inferred based on two complementary approaches: first, we compared the composition of soil pore waters of saturated areas in the peat plateau and the base of the hillslope, collected early and late in the thaw season (July and September) to assess seasonal changes in the soil solution chemistry. CH4 and low molecular weight organic acids (e.g., acetate, formate, and propionate) were both near or below the detection limit in July but accumulated later in the season. In contrast, SO42- and Fe(III) concentrations were high in July and low in September, while Fe(II) was higher in September. These results suggest SO42- and Fe(III) reduction were the primary pathways for anaerobic respiration early in the thaw season, while methanogenesis increased in September as labile organic acids accumulated. Second, we assessed the change in DOM composition in a transect of piezometers, capturing the degradation of organic matter during transport down a hillslope. The DOC concentration did not change, but SUVA254 declined and the organic acid concentration increased downslope. In addition, Fourier-transform infrared spectroscopy indicated the ratio of carboxyl to amide and aromatic functional groups increased downslope. These parameters show that although there was no net loss of DOC along the transect, it was transformed to less aromatic and potentially more labile forms. Together, these

  1. Teaching Future Teachers Basic Astronomy Concepts--Seasonal Changes--at a Time of Reform in Science Education

    Science.gov (United States)

    Trumper, Ricardo

    2006-01-01

    Bearing in mind students' misconceptions about basic concepts in astronomy, the present study conducted a series of constructivist activities aimed at changing future elementary and junior high school teachers' conceptions about the cause of seasonal changes, and several characteristics of the Sun-Earth-Moon relative movements like Moon phases,…

  2. Chirped Auger electron emission due to field-assisted post-collision interaction

    Directory of Open Access Journals (Sweden)

    Bonitz M.

    2013-03-01

    Full Text Available We have investigated the Auger decay in the temporal domain by applying a terahertz streaking light field. Xenon and krypton atoms were studied by implementing the free-electron laser in Hamburg (FLASH as well as a source of high-order harmonic radiation combined with terahertz pulses from an optical rectification source. The observed linewidth asymmetries in the streaked spectra suggest a chirped Auger electron emission which is understood in terms of field-assisted post-collision interaction. The experimentally obtained results agree well with model calculations.

  3. Simulated Vegetation Response to Climate Change in California: The Importance of Seasonal Production Patterns

    Science.gov (United States)

    Kim, J. B.; Pitts, B.

    2013-12-01

    MC1 dynamic global vegetation model simulates vegetation response to climate change by simulating vegetation production, soil biogeochemistry, plant biogeography and fire. It has been applied at a wide range of spatial scales, yet the spatio-temporal patterns of simulated vegetation production, which drives the model's response to climate change, has not been examined in detail. We ran MC1 for California at a relatively fine scale, 30 arc-seconds, for the historical period (1895-2006) and for the future (2007-2100), using downscaled data from four CMIP3-based climate projections: A2 and B1 GHG emissions scenarios simulated by PCM and GFDL GCMs. The use of these four climate projections aligns our work with a body of climate change research work commissioned by the California Public Interest Energy Research (PIER) Program. The four climate projections vary not only in terms of changes in their annual means, but in the seasonality of projected climate change. We calibrated MC1 using MODIS NPP data for 2000-2011 as a guide, and adapting a published technique for adjusting simulated vegetation production by increasing the simulated plant rooting depths. We evaluated the simulation results by comparing the model output for the historical period with several benchmark datasets, summarizing by EPA Level 3 Ecoregions. Multi-year summary statistics of model predictions compare moderately well with Kuchler's potential natural vegetation map, National Biomass and Carbon Dataset, Leenhouts' compilation of fire return intervals, and, of course, the MODIS NPP data for 2000-2011. When we compared MC1's monthly NPP values with MODIS monthly GPP data (2000-2011), however, the seasonal patterns compared very poorly, with NPP/GPP ratio for spring (Mar-Apr-May) often exceeding 1, and the NPP/GPP ratio for summer (Jun-Jul-Aug) often flattening to zero. This suggests MC1's vegetation production algorithms are overly biased for spring production at the cost of summer production. We

  4. Influenza vaccine effectiveness assessment through sentinel virological data in three post-pandemic seasons

    Science.gov (United States)

    Torner, Núria; Martínez, Ana; Basile, Luca; Marcos, M Angeles; Antón, Andrés; Mar Mosquera, M; Isanta, Ricard; Cabezas, Carmen; Jané, Mireia; Domínguez, Angela; Program of Catalonia, the PIDIRAC Sentinel Surveillance

    2014-01-01

    Influenza vaccination aims at reducing the incidence of serious disease, complications and death among those with the most risk of severe influenza disease. Influenza vaccine effectiveness (VE) through sentinel surveillance data from the PIDIRAC program (Daily Acute Respiratory Infection Surveillance of Catalonia) during 2010–2011, 2011–2012, and 2012–2013 influenza seasons, with three different predominant circulating influenza virus (IV) types [A(H1N1)pdm09, A(H3N2) and B, respectively] was assessed. The total number of sentinel samples with known vaccination background collected during the study period was 3173, 14.7% of which had received the corresponding seasonal influenza vaccine. 1117 samples (35.2%) were positive for IV. A retrospective negative case control design was used to assess vaccine effectiveness (VE) for the entire period and for each epidemic influenza season. An overall VE of 58.1% (95% CI:46.8–67) was obtained. Differences in VE according to epidemic season were observed, being highest for the 2012–2013 season with predominance of IV type B (69.7% ;95% CI:51.5–81) and for the 2010–2011 season, with predominance of the A(H1N1)pdm09 influenza virus strain (67.2% ;95%CI:49.5–78.8) and lowest for the 2011–2012 season with A(H3N2) subtype predominance (34.2% ;95%CI:4.5–54.6). Influenza vaccination prevents a substantial number of influenza-associated illnesses. Although vaccines with increased effectiveness are needed and the search for a universal vaccine that is not subject to genetic modifications might increase VE, nowadays only the efforts to increase vaccination rates of high-risk population and healthcare personnel let reduce the burden of influenza and its complications. PMID:25483540

  5. 20th-Century Climate Change over Africa: Seasonal Variation in Hydroclimate Trends and Sahara Desert Extent

    Science.gov (United States)

    Nigam, S.; Thomas, N. P.

    2017-12-01

    Twentieth-century trends in seasonal temperature and precipitation over the African continent are analyzed from observational data sets and historical climate simulations. Given the agricultural economy of the continent, a seasonal perspective is adopted as it is more pertinent than an annual-average one which can mask off-setting but agriculturally-sensitive seasonal hydroclimate variations. Examination of linear trends in seasonal surface air temperature (SAT) shows that heat stress has increased in several regions, including Sudan and Northern Africa where largest SAT trends occur in the warm season. Broadly speaking, the northern continent has warmed more than the southern one in all seasons. Precipitation trends are varied but notable declining trends are found in the countries along the Gulf of Guinea, especially in the source region of Niger river in West Africa, and in the Congo river basin. Rainfall over the African Great Lakes - one of the largest freshwater repositories - has however increased. We show that the Sahara Desert has expanded significantly over the 20th century - by 12-20% depending on the season. The desert expanded southward in summer, reflecting retreat of the northern edge of the Sahel rainfall belt; and to the north in winter, indicating potential impact of the widening of the Tropics. Specific mechanisms driving the expansion in each season are investigated. Finally, this observational analysis is used to evaluate the state-of-the-art climate models from a comparison of the 20th-century hydroclimate trends with those manifest in historical climate simulations. The evaluation shows that modeling regional hydroclimate change over the Africa continent remains challenging.

  6. Effects of seasonal change and parity on raw milk composition and related indices in Chinese Holstein cows in northern China.

    Science.gov (United States)

    Yang, L; Yang, Q; Yi, M; Pang, Z H; Xiong, B H

    2013-01-01

    This study was to investigate the effects of seasonal change and parity on milk composition and related indices, and to analyze the relationships among milk indices in Chinese Holstein cows from an intensive dairy farm in northern China. The 6,520 sets of complete Dairy Herd Improvement data were obtained and grouped by natural month and parity. The data included daily milk yield (DMY), milk solids percentage (MSP), milk fat percentage (MFP), milk protein percentage (MPP), milk lactose percentage (MLP), somatic cell count (SCC), somatic cell score (SCS), milk production loss (MPL), and fat-to-protein ratio (FPR). Data analysis showed that the above 9 indices were affected by both seasonal change and parity. However, the interaction between parity and seasonal change showed effects on MLP, SCS, MPL, and DMY, but no effects on MFP, MPP, MSP, and FPR. Duncan's multiple comparison on seasonal change showed that DMY (23.58 kg/d), MSP (12.35%), MPP (3.02%), and MFP (3.81%) were the lowest in June, but SCC (288.7 × 10(3)/mL) and MPL (0.69 kg/d) were the lowest in January; FPR (1.32) was the highest in February. Meanwhile, Duncan's multiple comparison on parities showed that MSP, MPP, and MLP were reduced rapidly in the fourth lactation, but SCC and MPL increased with increasing parities. The canonical correlation analysis for indices showed that SCS had high positive correlation with MPL (0.8360). Therefore, a few models were developed to quantify the effects of seasonal change and parity on raw milk composition using the Wood model. The changing patterns of milk composition and related indices in different months and parities could provide scientific evidence for improving feeding management and nutritional supplementation of Chinese Holstein cows. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. Seasonal changes in Fe along a glaciated Greenlandic fjord.

    Directory of Open Access Journals (Sweden)

    Mark James Hopwood

    2016-03-01

    Full Text Available Greenland’s ice sheet is the second largest on Earth, and is under threat from a warming Arctic climate. An increase in freshwater discharge from Greenland has the potential to strongly influence the composition of adjacent water masses with the largest impact on marine ecosystems likely to be found within the glaciated fjords. Here we demonstrate that physical and chemical estuarine processes within a large Greenlandic fjord are critical factors in determining the fate of meltwater derived nutrients and particles, especially for non-conservative elements such as Fe. Concentrations of Fe and macronutrients in surface waters along Godthåbsfjord, a southwest Greenlandic fjord with freshwater input from 6 glaciers, changed markedly between the onset and peak of the meltwater season due to the development of a thin (<10 m, outflowing, low-salinity surface layer. Dissolved (<0.2 µm Fe concentrations in meltwater entering Godthåbsfjord (200 nM, in freshly melted glacial ice (mean 38 nM and in surface waters close to a land terminating glacial system (80 nM all indicated high Fe inputs into the fjord in summer. Total dissolvable (unfiltered at pH <2.0 Fe was similarly high with concentrations always in excess of 100 nM throughout the fjord and reaching up to 5.0 µM close to glacial outflows in summer. Yet, despite the large seasonal freshwater influx into the fjord, Fe concentrations near the fjord mouth in the out-flowing surface layer were similar in summer to those measured before the meltwater season. Furthermore, turbidity profiles indicated that sub-glacial particulate Fe inputs may not actually mix into the outflowing surface layer of this fjord. Emphasis has previously been placed on the possibility of increased Fe export from Greenland as meltwater fluxes increase. Here we suggest that in-fjord processes may be effective at removing Fe from surface waters before it can be exported to coastal seas.

  8. Nutrient Removal Vis-à-Vis Change in Partial Pressure of CO2 During Post-Monsoon Season in a Tropical Lentic and Lotic Aquatic Body: A Comparative Study

    Science.gov (United States)

    Bhattacharyya, Sourav; Chanda, Abhra; Das, Sourav; Akhand, Anirban; Pattanaik, Suchismita; Choudhury, S. B.; Dutta, Dibyendu; Hazra, Sugata

    2018-04-01

    The rate of nutrient removal and changes in pCO2 (water) were compared between a lentic aquaculture pond [East Kolkata Wetlands (EKW), India] and a lotic estuarine system [Diamond Harbor (DH) in Hugli Estuary, India] during the post-monsoon season (experiencing a similar tropical climate) by means of ex situ microcosm experiment. Though the DH waters were found to be substantial source of CO2 towards atmosphere and EKW waters to be sink for CO2 (according to the initial concentration of CO2), the eight consecutive days microcosm experiment revealed that the nutrient removal and pCO2 reduction efficiency were significantly higher in DH (ΔpCO2—90%) compared to EKW (ΔpCO2—78%). Among the five nutrients studied [dissolved nitrate-nitrogen (NO3-N), dissolved ammonium nitrogen (NH4-N), silicate, phosphate and iron], dissolved NO3-N followed by NH4-N was the most utilized in both EKW and DH. Except silicate, the other nutrients reduced to 78-91% in EKW and 84-99% in DH samples of their initial concentrations. Chlorophyll-a concentration steadily depleted in EKW ( 68-26 mg m-3) during the experiment indicating intense zooplankton grazing, whereas in DH it increased rapidly ( 3.4-23 mg m-3) with decreasing pCO2 (water). The present observations further indicated that regular flushing of EKW aquaculture ponds is required to avoid stagnation of water column which would enhance the zooplankton grazing and hamper the primary production of an otherwise sink of CO2. In DH, controlled freshwater discharge from Farakka and reduction of untreated organic waste might allow the existing phytoplankton community to enhance their photosynthetic activity.

  9. The Impact of Climate Change on the Duration and Division of Flood Season in the Fenhe River Basin, China

    Directory of Open Access Journals (Sweden)

    Hejia Wang

    2016-03-01

    Full Text Available This study analyzes the duration and division of the flood season in the Fenhe River Basin over the period of 1957–2014 based on daily precipitation data collected from 14 meteorological stations. The Mann–Kendall detection, the multiscale moving t-test, and the Fisher optimal partition methods are used to evaluate the impact of climate change on flood season duration and division. The results show that the duration of the flood season has extended in 1975–2014 compared to that in 1957–1974. Specifically, the onset date of the flood season has advanced 15 days, whereas the retreat date of the flood season remains almost the same. The flood season of the Fenhe River Basin can be divided into three stages, and the variations in the onset and retreat dates of each stage are also examined. Corresponding measures are also proposed to better utilize the flood resources to adapt to the flood season variations.

  10. Monitoring groundwater storage changes in the highly seasonal humid tropics: Validation of GRACE measurements in the Bengal Basin

    Science.gov (United States)

    Shamsudduha, M.; Taylor, R. G.; Longuevergne, L.

    2012-02-01

    Satellite monitoring of changes in terrestrial water storage provides invaluable information regarding the basin-scale dynamics of hydrological systems where ground-based records are limited. In the Bengal Basin of Bangladesh, we test the ability of satellite measurements under the Gravity Recovery and Climate Experiment (GRACE) to trace both the seasonality and trend in groundwater storage associated with intensive groundwater abstraction for dry-season irrigation and wet-season (monsoonal) recharge. We show that GRACE (CSR, GRGS) datasets of recent (2003 to 2007) groundwater storage changes (ΔGWS) correlate well (r = 0.77 to 0.93, p value CSR. Changes in surface water storage estimated from a network of 298 river gauging stations and soil-moisture derived from Land Surface Models explain 22% and 33% of ΔTWS, respectively. Groundwater depletion estimated from borehole hydrographs (-0.52 ± 0.30 km3 yr-1) is within the range of satellite-derived estimates (-0.44 to -2.04 km3 yr-1) that result from uncertainty associated with the simulation of soil moisture (CLM, NOAH, VIC) and GRACE signal-processing techniques. Recent (2003 to 2007) estimates of groundwater depletion are substantially greater than long-term (1985 to 2007) mean (-0.21 ± 0.03 km3 yr-1) and are explained primarily by substantial increases in groundwater abstraction for the dry-season irrigation and public water supplies over the last two decades.

  11. Seasonal changes in stable carbon isotope ratios within annual growth rings of Pinus radiata

    International Nuclear Information System (INIS)

    Walcroft, A.; Silvester, W.; Whitehead, D.; Kelliher, F.

    1997-01-01

    The stable isotope composition of photosynthetically assimilated carbon (δ 13 C) is determined by the ratio of the leaf internal CO 2 concentration (c i ) to that of the ambient air (c a ), and so reflects the contribution of both stomatal conductance (g s ) and the rate of photosynthesis (A). Assimilated carbon which is subsequently laid down as wood in annual growth rings may therefore represent a time integrated record of physiological responses by the whole tree to seasonal changes in the environmental variables regulating growth. We analysed the stable carbon isotope composition of Pinus radiata wood collected from two plantation forest sites in New Zealand which differ markedly in temperature, rainfall and soil characteristics. For both sites, discs were cut from the stem of several trees near ground level and whole wood samples were taken from within individual annual growth rings over a number of years. At one site, diameter bands were installed over the 1994 - 1996 growing seasons in order to date precisely the formation of wood during that time. Trees at each site consistently showed a seasonal pattern in the stable isotope composition of wood within individual growth rings. The amplitude of seasonal δ 13 C variation at the wet and dry sites were 1-2 per thousand and 4 per thousand respectively. Mean δ 13 C values from the wet site were 3 per thousand more 13 C depleted than those from the dry site implying lower water-use efficiency (carbon assimilation per unit transpiration). A process-based, model of stomatal conductance and CO 2 assimilation was combined with a soil-water balance model to estimate the average daily leaf-level intercellular CO 2 concentration (c i ). Over two growing seasons at each site there was generally good agreement between mean canopy-level c i derived from the tree-ring δ 13 C data and modelled leaf-level c i levels. Further, the ratio of annual CO 2 assimilation to transpiration estimated by the model for each site

  12. Seasonal timing of reproduction in a tropical bird, the Seychelles warbler : A field experiment using translocation

    NARCIS (Netherlands)

    Komdeur, J

    1996-01-01

    Reproduction of the Seychelles warbler (Acrocephalus sechellensis), a single-island endemic species living close to the equator, is characterized by a pronounced annual rhythm. The bird usually raises only one or two clutches of one egg each per year. Observational data suggest that seasonal changes

  13. Acceleration and Counteraction of Changes in Vegetation Seasonality and Patterns using CMIP5 Projections from Different ESMs.

    Science.gov (United States)

    Chavaillaz, Y.; Joussaume, S.; De Noblet-Decoudre, N.

    2017-12-01

    Most climatological studies characterize future climate change as the evolution between a fixed current baseline and the future. Considering the pace of future climate change is however of major importance, since it may strongly influence how we experience climate hazards. To complement previous work related to the pace of temperature and precipitation changes, we propose here to study how fast vegetation seasonality and patterns of climate change evolve in different future configurations according to CMIP5 simulations of several Earth system models. The pace is defined as the difference in relevant metrics between two successive 20-year periods, i.e. with a continually moving baseline. Shifts of vegetation groups and changes in the characteristics of the seasonal cycle are considered. Both accelerate in close relationship with the warming rate regardless of the selected scenario, but they balance each other out, especially for trees in northern mid- and high-latitudes. Efforts are nevertheless strongly needed to harmonize the representation of vegetation in new versions of model inter-comparison projects, in order to properly conduct multi-model analyses related to vegetation changes.

  14. Seasonal Variation in Monthly Average Air Change Rates Using Passive Tracer Gas Measurements

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Bergsøe, Niels Christian; Kolarik, Barbara

    2011-01-01

    in five dwellings in Greater Copenhagen, Denmark. A passive tracer gas technique (Perfluorocarbon) was used to measure ACR in a seven-month period. Considerable differences were observed between the dwellings with monthly ACRs ranging from 0.21 to 1.75 h-1. Only smaller seasonal variations, generally less...... driving forces for natural ventilation is partially compensated by changed occupant behaviour....

  15. Projected changes in atmospheric heating due to changes in fire disturbance and the snow season in the western Arctic, 2003–2100

    Science.gov (United States)

    Euskirchen, E.S.; McGuire, A. David; Rupp, T.S.; Chapin, F. S.; Walsh, J.E.

    2009-01-01

    In high latitudes, changes in climate impact fire regimes and snow cover duration, altering the surface albedo and the heating of the regional atmosphere. In the western Arctic, under four scenarios of future climate change and future fire regimes (2003–2100), we examined changes in surface albedo and the related changes in regional atmospheric heating due to: (1) vegetation changes following a changing fire regime, and (2) changes in snow cover duration. We used a spatially explicit dynamic vegetation model (Alaskan Frame-based Ecosystem Code) to simulate changes in successional dynamics associated with fire under the future climate scenarios, and the Terrestrial Ecosystem Model to simulate changes in snow cover. Changes in summer heating due to the changes in the forest stand age distributions under future fire regimes showed a slight cooling effect due to increases in summer albedo (mean across climates of −0.9 W m−2 decade−1). Over this same time period, decreases in snow cover (mean reduction in the snow season of 4.5 d decade−1) caused a reduction in albedo, and a heating effect (mean across climates of 4.3 W m−2 decade−1). Adding both the summer negative change in atmospheric heating due to changes in fire regimes to the positive changes in atmospheric heating due to changes in the length of the snow season resulted in a 3.4 W m−2 decade−1 increase in atmospheric heating. These findings highlight the importance of gaining a better understanding of the influences of changes in surface albedo on atmospheric heating due to both changes in the fire regime and changes in snow cover duration.

  16. Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field.

    Science.gov (United States)

    Liang, Guopeng; Houssou, Albert A; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

    2015-01-01

    Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013-2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha(-1) year(-1) (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013-2014 and 2014-2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013-2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014-2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration.

  17. Seasonal changes in vitamin D status and bone turnover in healthy Irish postmenopausal women

    DEFF Research Database (Denmark)

    Hill, T.R.; McCarthy, D.; Jakobsen, Jette

    2007-01-01

    Objectives: To examine the effect of season on biochemical markers of bone turnover in 51-to 75-year-old Irish women and to investigate whether such changes are related to vitamin D status. Design: Longitudinal observational study. Setting: Cork, Ireland (52 degrees N). Subjects: 76 apparently...... healthy, free-living postmenopausal women (aged 51-75 years), not taking any medication and free from any condition likely to affect vitamin D status or calcium/bone metabolism. Results: Serum 25-hydroxyvitamin D [S-25(OH)D] showed a clear seasonal variation with significantly higher (p ... during late summer than late winter. Both urinary pyridinoline (Ur-Pyr) (p women into those with S-25(OH)D levels...

  18. Seasonal changes in background levels of deuterium and oxygen-18 prove water drinking by harp seals, which affects the use of the doubly labelled water method.

    Science.gov (United States)

    Nordøy, Erling S; Lager, Anne R; Schots, Pauke C

    2017-12-01

    The aim of this study was to monitor seasonal changes in stable isotopes of pool freshwater and harp seal ( Phoca groenlandica ) body water, and to study whether these potential seasonal changes might bias results obtained using the doubly labelled water (DLW) method when measuring energy expenditure in animals with access to freshwater. Seasonal changes in the background levels of deuterium and oxygen-18 in the body water of four captive harp seals and in the freshwater pool in which they were kept were measured over a time period of 1 year. The seals were offered daily amounts of capelin and kept under a seasonal photoperiod of 69°N. Large seasonal variations of deuterium and oxygen-18 in the pool water were measured, and the isotope abundance in the body water showed similar seasonal changes to the pool water. This shows that the seals were continuously equilibrating with the surrounding water as a result of significant daily water drinking. Variations in background levels of deuterium and oxygen-18 in freshwater sources may be due to seasonal changes in physical processes such as precipitation and evaporation that cause fractionation of isotopes. Rapid and abrupt changes in the background levels of deuterium and oxygen-18 may complicate calculation of energy expenditure by use of the DLW method. It is therefore strongly recommended that analysis of seasonal changes in background levels of isotopes is performed before the DLW method is applied on (free-ranging) animals, and to use a control group in order to correct for changes in background levels. © 2017. Published by The Company of Biologists Ltd.

  19. Changes in the thermal growing season in Nordic countries during the past century and prospects for the future

    Directory of Open Access Journals (Sweden)

    Timothy R. Carter

    1998-01-01

    Full Text Available The start, end, duration and intensity of the thermal growing season (the period with mean daily temperatures exceeding 5°C during the past century (1890-1995 was analysed at nine sites in the Nordic region. Statistical comparisons were made between three adjacent 35-year periods. The results indicate that the growing season lengthened considerably at all sites between 1891-1925 and 1926-1960. Lengthening has continued at a slower rate up to the present at the eight Fennoscandian sites but not at the Icelandic site. In contrast, the intensity of the growing season, expressed by effective temperature sum above 5°C, which increased at all sites between the first two periods, has decreased slightly at all locations except Turku in recent decades. Under three scenarios, representing the range of estimated greenhouse gas-induced warming by the 2050s, the growing season is expected to lengthen at all sites. For a “Central” scenario, the greatest lengthening is computed for southern and western Scandinavia (7-8 weeks with smaller changes in Finland (4 weeks and Iceland (3 weeks. With a lengthening growing season during the past century in Fennoscandia, there are likely to have been impacts on natural and managed ecosystems. Some evidence of recent biotic and abiotic effects already exists, but other indicators of long-term change remain to be analysed.

  20. Changes in the thermal growing season in Nordic countries during the past century and prospects for the future

    Directory of Open Access Journals (Sweden)

    T.R. CARTER

    2008-12-01

    Full Text Available The start, end, duration and intensity of the thermal growing season (the period with mean daily temperatures exceeding 5°C during the past century (1890-1995 was analysed at nine sites in the Nordic region. Statistical comparisons were made between three adjacent 35-year periods. The results indicate that the growing season lengthened considerably at all sites between 1891-1925 and 1926-1960. Lengthening has continued at a slower rate up to the present at the eight Fennoscandian sites but not at the Icelandic site. In contrast, the intensity of the growing season, expressed by effective temperature sum above 5°C, which increased at all sites between the first two periods, has decreased slightly at all locations except Turku in recent decades. Under three scenarios, representing the range of estimated greenhouse gas-induced warming by the 2050s, the growing season is expected to lengthen at all sites. For a "Central" scenario, the greatest lengthening is computed for southern and western Scandinavia (7-8 weeks with smaller changes in Finland (4 weeks and Iceland (3 weeks. With a lengthening growing season during the past century in Fennoscandia, there are likely to have been impacts on natural and managed ecosystems. Some evidence of recent biotic and abiotic effects already exists, but other indicators of long-term change remain to be analysed. ;

  1. Shifts of growing-season precipitation peaks decrease soil respiration in a semiarid grassland.

    Science.gov (United States)

    Ru, Jingyi; Zhou, Yaqiong; Hui, Dafeng; Zheng, Mengmei; Wan, Shiqiang

    2018-03-01

    Changing precipitation regimes could have profound influences on carbon (C) cycle in the biosphere. However, how soil C release from terrestrial ecosystems responds to changing seasonal distribution of precipitation remains unclear. A field experiment was conducted for 4 years (2013-2016) to examine the effects of altered precipitation distributions in the growing season on soil respiration in a temperate steppe in the Mongolian Plateau. Over the 4 years, both advanced and delayed precipitation peaks suppressed soil respiration, and the reductions mainly occurred in August. The decreased soil respiration could be primarily attributable to water stress and subsequently limited plant growth (community cover and belowground net primary productivity) and soil microbial activities in the middle growing season, suggesting that precipitation amount in the middle growing season is more important than that in the early, late, or whole growing seasons in regulating soil C release in grasslands. The observations of the additive effects of advanced and delayed precipitation peaks indicate semiarid grasslands will release less C through soil respiratory processes under the projected seasonal redistribution of precipitation in the future. Our findings highlight the potential role of intra-annual redistribution of precipitation in regulating ecosystem C cycling in arid and semiarid regions. © 2017 John Wiley & Sons Ltd.

  2. Post-adolescent developmental changes in cortical complexity

    OpenAIRE

    Sandu, Anca-Larisa; Izard, Edouard; Specht, Karsten; Beneventi, Harald; Lundervold, Arvid; Ystad, Martin

    2014-01-01

    Background: Post-adolescence is known to be a period of general maturation and development in the human brain. In brain imaging, volumetric and morphologic cortical grey-matter changes can easily be assessed, but the analysis of cortical complexity seems to have been broadly neglected for this age interval. Methods: Magnetic resonance imaging (MRI) was used to acquire structural brain images. The study involved 17 adolescents (mean age 14.1 ± 0.27, 11 girls) who were compared with 1...

  3. Studying the Post-Fire Response of Vegetation in California Protected Areas with NDVI-based Pheno-Metrics

    Science.gov (United States)

    Jia, S.; Gillespie, T. W.

    2016-12-01

    Post-fire response from vegetation is determined by the intensity and timing of fires as well as the nature of local biomes. Though the field-based studies focusing on selected study sites helped to understand the mechanisms of post-fire response, there is a need to extend the analysis to a broader spatial extent with the assistance of remotely sensed imagery of fires and vegetation. Pheno-metrics, a series of variables on the growing cycle extracted from basic satellite measurements of vegetation coverage, translate the basic remote sensing measurements such as NDVI to the language of phenology and fire ecology in a quantitative form. In this study, we analyzed the rate of biomass removal after ignition and the speed of post-fire recovery in California protected areas from 2000 to 2014 with USGS MTBS fire data and USGS eMODIS pheno-metrics. NDVI drop caused by fire showed the aboveground biomass of evergreen forest was removed much slower than shrubland because of higher moisture level and greater density of fuel. In addition, the above two major land cover types experienced a greatly weakened immediate post-fire growing season, featuring a later start and peak of season, a shorter length of season, and a lower start and peak of NDVI. Such weakening was highly correlated with burn severity, and also influenced by the season of fire and the land cover type, according to our modeling between the anomalies of pheno-metrics and the difference of normalized burn ratio (dNBR). The influence generally decayed over time, but can remain high within the first 5 years after fire, mostly because of the introduction of exotic species when the native species were missing. Local-specific variables are necessary to better address the variance within the same fire and improve the outcomes of models. This study can help ecologists in validating the theories of post-fire vegetation response mechanisms and assist local fire managers in post-fire vegetation recovery.

  4. ABRUPT LONGITUDINAL MAGNETIC FIELD CHANGES IN FLARING ACTIVE REGIONS

    International Nuclear Information System (INIS)

    Petrie, G. J. D.; Sudol, J. J.

    2010-01-01

    We characterize the changes in the longitudinal photospheric magnetic field during 38 X-class and 39 M-class flares within 65 0 of disk center using 1 minute GONG magnetograms. In all 77 cases, we identify at least one site in the flaring active region where clear, permanent, stepwise field changes occurred. The median duration of the field changes was about 15 minutes and was approximately equal for X-class and for M-class flares. The absolute values of the field changes ranged from the detection limit of ∼10 G to as high as ∼450 G in two exceptional cases. The median value was 69 G. Field changes were significantly stronger for X-class than for M-class flares and for limb flares than for disk-center flares. Longitudinal field changes less than 100 G tended to decrease longitudinal field strengths, both close to disk center and close to the limb, while field changes greater than 100 G showed no such pattern. Likewise, longitudinal flux strengths tended to decrease during flares. Flux changes, particularly net flux changes near disk center, correlated better than local field changes with GOES peak X-ray flux. The strongest longitudinal field and flux changes occurred in flares observed close to the limb. We estimate the change of Lorentz force associated with each flare and find that this is large enough in some cases to power seismic waves. We find that longitudinal field decreases would likely outnumber increases at all parts of the solar disk within 65 0 of disk center, as in our observations, if photospheric field tilts increase during flares as predicted by Hudson et al.

  5. The GPM Ground Validation Program: Pre to Post-Launch

    Science.gov (United States)

    Petersen, W. A.

    2014-12-01

    NASA GPM Ground Validation (GV) activities have transitioned from the pre to post-launch era. Prior to launch direct validation networks and associated partner institutions were identified world-wide, covering a plethora of precipitation regimes. In the U.S. direct GV efforts focused on use of new operational products such as the NOAA Multi-Radar Multi-Sensor suite (MRMS) for TRMM validation and GPM radiometer algorithm database development. In the post-launch, MRMS products including precipitation rate, types and data quality are being routinely generated to facilitate statistical GV of instantaneous and merged GPM products. To assess precipitation column impacts on product uncertainties, range-gate to pixel-level validation of both Dual-Frequency Precipitation Radar (DPR) and GPM microwave imager data are performed using GPM Validation Network (VN) ground radar and satellite data processing software. VN software ingests quality-controlled volumetric radar datasets and geo-matches those data to coincident DPR and radiometer level-II data. When combined MRMS and VN datasets enable more comprehensive interpretation of ground-satellite estimation uncertainties. To support physical validation efforts eight (one) field campaigns have been conducted in the pre (post) launch era. The campaigns span regimes from northern latitude cold-season snow to warm tropical rain. Most recently the Integrated Precipitation and Hydrology Experiment (IPHEx) took place in the mountains of North Carolina and involved combined airborne and ground-based measurements of orographic precipitation and hydrologic processes underneath the GPM Core satellite. One more U.S. GV field campaign (OLYMPEX) is planned for late 2015 and will address cold-season precipitation estimation, process and hydrology in the orographic and oceanic domains of western Washington State. Finally, continuous direct and physical validation measurements are also being conducted at the NASA Wallops Flight Facility multi

  6. Seasonal Changes in Microbial Community Structure in Freshwater Stream Sediment in a North Carolina River Basin

    Directory of Open Access Journals (Sweden)

    John P. Bucci

    2014-01-01

    Full Text Available This study examined seasonal differences in microbial community structure in the sediment of three streams in North Carolina’s Neuse River Basin. Microbes that reside in sediment are at the base of the food chain and have a profound influence on the health of freshwater stream environments. Terminal-Restriction Fragment Length Polymorphism (T-RFLP, molecular fingerprint analysis of 16S rRNA genes was used to examine the diversity of bacterial species in stream sediment. Sediment was sampled in both wet and dry seasons from an agricultural (Bear, mixed urban (Crabtree and forested (Marks Creek, and the microbiota examined. Gamma, Alpha and Beta proteobacteria were prevalent species of microbial taxa represented among all sites. Actinobacteria was the next most prevalent species observed, with greater occurrence in dry compared to the wet season. Discernable clustering was observed of Marks and Bear Creek samples collected during the wetter period (September–April, which corresponded with a period of higher precipitation and cooler surface water temperatures. Although not statistically significant, microbial community structure appeared different between season (ANOSIM, R = 0.60; p < 0.10. Principal components analysis confirmed this pattern and showed that the bacterial groups were separated by wet and dry seasonal periods. These results suggest seasonal differences among the microbial community structure in sediment of freshwater streams and that these communities may respond to changes in precipitation during wetter periods.

  7. Seasonal patterns in soil N availability in the arctic tundra in response to accelerated snowmelt and warming

    Science.gov (United States)

    Darrouzet-Nardi, A.; Wallenstein, M. D.; Steltzer, H.; Sullivan, P.; Melle, C.; Segal, A.; Weintraub, M. N.

    2010-12-01

    Arctic soils contain large stocks of carbon (C) and may act as a significant CO2 source in response to climate warming. However, nitrogen (N) availability limits both plant growth and decomposition in many Arctic sites, and may thus be a key constraint on climate-carbon feedbacks. While current models of tundra ecosystems and their responses to climate change assume that N limits plant growth and C limits decomposition, there is strong evidence to the contrary showing that N can also limit decomposition. For example, the production of both new microbial biomass and enzymes that degrade organic matter appear to be limited by N during the summer. N availability is strongly seasonal: we have previously observed relatively high availability early in the growing season followed by a pronounced crash in tussock tundra soils. To investigate the drivers of N availability throughout the season, we used a field manipulation of tussock tundra growing season length (~4 days acceleration of snowmelt) and air temperature (open top chambers) and a laboratory soil N addition in both early and late season. Nutrient availability throughout the field season was measured at high temporal resolution (25 measurements from soil thaw through early plant senescence). Results from a laboratory experiment in which N was added to early season and late season soils suggests that soil respiration is in fact N limited at both times of the season, though this limitation is temperature dependent with effects most pronounced at 10°C. High-resolution measurements of nutrients in the soil solution and extractable N throughout the season showed that although a nutrient crash in N can be observed mid-season, N availability can still fluctuate later in the season. Finally, effects of the extended growing season and increased air temperature have so far had few effects on soil nutrient N dynamics throughout the summer growing season, suggesting either an insensitivity of N availability to these

  8. Seasonal and annual plant production of a southern Manitoba old-field

    International Nuclear Information System (INIS)

    Turner, B.N.; Iverson, S.L.

    1980-06-01

    The amount of natural variation in vegetation production during Project ZEUS (an investigation of long-term gamma radiation on meadow voles) will constitute an important habitat variable for the meadow vole population. To quantify this variation, annual and seasonal plant production of a nearby old-field was estimated by monthly harvests of aboveground vegetation between April and October for five consecutive years. The amount of dry green vegetation varied significantly both among years and months, peaking at a mean of nearly 300 G. M -2 in late July and late August. Mean rates of production were maximum in late May to late June, reaching 4.45 g.m -2 .d -1 . Dead vegetation varied significantly among months, but not among years, with peak amounts of nearly 800 G. M -2 in May and October. Moss quantities varied among years, but not among months, and showed a general trend to increase as the field aged. Monthly production of green vegetation showed some relationships to precipitation and temperature, and particularly indicated that hot dry springs impeded growth. Both amount and rate of green production were greater than that on most similar old-fields reported in the literature, and generally exceeded levels on all native grasslands except tallgrass prairie. Annual variability in peak green production was similar to that on other grasslands and old-fields. Variability in green production was greatest in April, and least in June, at the time when production was greatest. Greatest variation in green production occurred at the same time as greatest variation in temperature. Low precipitation may limit production, but the amount of precipitation does not appear to have an effect above a certain minimum level. (auth)

  9. Monitoring Seasonal Changes in Permafrost Using Seismic Interferometry

    Science.gov (United States)

    James, S. R.; Knox, H. A.; Abbott, R. E.

    2015-12-01

    The effects of climate change in polar regions and their incorporation in global climate models has recently become an area of great interest. Permafrost holds entrapped greenhouse gases, e.g. CO2 and CH4, which are released to the atmosphere upon thawing, creating a positive feedback mechanism. Knowledge of seasonal changes in active layer thickness as well as long term degradation of permafrost is critical to the management of high latitude infrastructures, hazard mitigation, and increasing the accuracy of climate predictions. Methods for effectively imaging the spatial extent, depth, thickness, and discontinuous nature of permafrost over large areas are needed. Furthermore, continuous monitoring of permafrost over annual time scales would provide valuable insight into permafrost degradation. Seismic interferometry using ambient seismic noise has proven effective for recording velocity changes within the subsurface for a variety of applications, but has yet to be applied to permafrost studies. To this end, we deployed 7 Nanometrics Trillium posthole broadband seismometers within Poker Flat Research Range, located 30 miles north of Fairbanks, Alaska in a zone of discontinuous permafrost. Approximately 2 years worth of nearly continuous ambient noise data was collected. Using the python package MSNoise, relative changes in velocity were calculated. Results show high amounts of variability throughout the study period. General trends of negative relative velocity shifts can be seen between August and October followed by a positive relative velocity shift between November and February. Differences in relative velocity changes with both frequency and spatial location are also observed, suggesting this technique is sensitive to permafrost variation with depth and extent. Overall, short and long term changes in shallow subsurface velocity can be recovered using this method proposing seismic interferometry is a promising new technique for permafrost monitoring. Sandia

  10. Variations of atmospheric electric field and meteorological parameters in Kamchatka in 1997-2016

    Directory of Open Access Journals (Sweden)

    Smirnov Sergey

    2017-01-01

    Full Text Available Analysis of seasonal and annual variations of aero-electric field at a midlatitudinal observatory Paratunka in Kamchatka was carried out for 1997-2016. Stable seasonal intervals of the highest and the lowest values are observed. Changeability of the annual trend of aero-electric field in the near ground air layer at the observatory located in an active geodynamic region is shown. A large positive trend was changed by a smooth negative one. It is likely to be associated either with radon emanation intensity change in the observatory region or with volcanic activity change in Kamchatka.

  11. Surface ozone seasonality under global change: Influence from dry deposition and isoprene emissions at northern mid-latitudes

    Science.gov (United States)

    Clifton, O.; Paulot, F.; Fiore, A. M.; Horowitz, L. W.; Malyshev, S.; Shevliakova, E.; Correa, G. J. P.; Lin, M.

    2017-12-01

    Identifying the contributions of nonlinear chemistry and transport to observed surface ozone seasonal cycles over land using global models relies on an accurate representation of ozone uptake by vegetation (dry deposition). It is well established that in the absence of ozone precursor emission changes, a warming climate will increase surface ozone in polluted regions, and that a rise in temperature-dependent isoprene emissions would exacerbate this "climate penalty". However, the influence of changes in ozone dry deposition, expected to evolve with climate and land use, is often overlooked in air quality projections. With a new scheme that represents dry deposition within the NOAA GFDL dynamic vegetation land model (LM3) coupled to the NOAA GFDL atmospheric chemistry-climate model (AM3), we simulate the impact of 21st century climate and land use on ozone dry deposition and isoprene emissions. This dry deposition parameterization is a version of the Wesely scheme, but uses parameters explicitly calculated by LM3 that respond to climate and land use (e.g., stomatal conductance, canopy interception of water, leaf area index). The parameterization includes a nonstomatal deposition dependence on humidity. We evaluate climatological present-day seasonal cycles of ozone deposition velocities and abundances with those observed at northern mid-latitude sites. With a set of 2010s and 2090s decadal simulations under a high climate warming scenario (RCP8.5) and a sensitivity simulation with well-mixed greenhouse gases following RCP8.5 but air pollutants held at 2010 levels (RCP8.5_WMGG), we examine changes in surface ozone seasonal cycles. We build on our previous findings, which indicate that strong reductions in anthropogenic NOx emissions under RCP8.5 cause the surface ozone seasonal cycle over the NE USA to reverse, shifting from a summer peak at present to a winter peak by 2100. Under RCP8.5_WMGG, we parse the separate effects of climate and land use on ozone dry

  12. Seasonal Patterns of Soil Respiration and Related Soil Biochemical Properties under Nitrogen Addition in Winter Wheat Field

    Science.gov (United States)

    Liang, Guopeng; Houssou, Albert A.; Wu, Huijun; Cai, Dianxiong; Wu, Xueping; Gao, Lili; Li, Jing; Wang, Bisheng; Li, Shengping

    2015-01-01

    Understanding the changes of soil respiration under increasing N fertilizer in cropland ecosystems is crucial to accurately predicting global warming. This study explored seasonal variations of soil respiration and its controlling biochemical properties under a gradient of Nitrogen addition during two consecutive winter wheat growing seasons (2013–2015). N was applied at four different levels: 0, 120, 180 and 240 kg N ha-1 year-1 (denoted as N0, N12, N18 and N24, respectively). Soil respiration exhibited significant seasonal variation and was significantly affected by soil temperature with Q10 ranging from 2.04 to 2.46 and from 1.49 to 1.53 during 2013–2014 and 2014–2015 winter wheat growing season, respectively. Soil moisture had no significant effect on soil respiration during 2013–2014 winter wheat growing season but showed a significant and negative correlation with soil respiration during 2014–2015 winter wheat growing season. Soil respiration under N24 treatment was significantly higher than N0 treatment. Averaged over the two growing seasons, N12, N18 and N24 significantly increased soil respiration by 13.4, 16.4 and 25.4% compared with N0, respectively. N addition also significantly increased easily extractable glomalin-related soil protein (EEG), soil organic carbon (SOC), total N, ammonium N and nitrate N contents. In addition, soil respiration was significantly and positively correlated with β-glucosidase activity, EEG, SOC, total N, ammonium N and nitrate N contents. The results indicated that high N fertilization improved soil chemical properties, but significantly increased soil respiration. PMID:26629695

  13. Field test of a post-closure radiation monitor

    International Nuclear Information System (INIS)

    Reed, S.; Christy, C.E.; Heath, R.E.

    1995-01-01

    The DOE is conducting remedial actions at many sites contaminated with radioactive materials. After closure of these sites, long-term subsurface monitoring is typically required by law. This monitoring is generally labor intensive and expensive using conventional sampling and analysis techniques. The U.S. Department of Energy's Morgantown Energy Technology Center (METC) has contracted with Babcock and Wilcox to develop a Long-Term Post-Closure Radiation Monitoring System (LPRMS) to reduce these monitoring costs. A prototype LPRMS probe was built, and B ampersand W and FERMCO field tested this monitoring probe at the Fernald Environmental Management Project in the fall of 1994 with funding from the DOE's Office of Technology Development (EM-50) through METC. The system was used to measure soil and water with known uranium contamination levels, both in drums and in situ at depths up to 3 meters. For comparison purposes, measurements were also performed using a more conventional survey probe with a sodium iodide scintillator directly butt-coupled to detection electronics. This paper presents a description and the results of the field tests. The results were used to characterize the lower detection limits, precision and bias of the system, which allowed the DOE to judge the monitoring system's ability to meet its long-term post-closure radiation monitoring needs. Based on the test results, the monitoring system has been redesigned for fabrication and testing in a potential Phase III of this program. If the DOE feels that this system can meet its needs and chooses to continue into Phase III of this program, this redesigned full scale prototype system will be built and tested for a period of approximately a year. Such a system can be used at a variety of radioactively contaminated sites

  14. Effect of season on peripheral resistance to localised cold stress

    Science.gov (United States)

    Tanaka, M.; Harimura, Y.; Tochihara, Y.; Yamazaki, S.; Ohnaka, T.; Matsui, J.; Yoshida, K.

    1984-03-01

    This study was carried out to determine the effect that seasonal changes have on the effect of localised cold stress on peripheral temperatures using the foot immersion method with a cold water bath. The subjects were six males and four females. The data were obtained in April, July, October and January. Skin temperature of the right index finger, the forehead, the arm, the cheek, the second toe and the instep were measured before, during and after the immersion of the feet in water at 15°C for 10 mins, as well as oxygen consumption before immersion of the feet. The average finger temperature was highest during foot immersion in the summer, next highest in the winter, then spring, and the lowest during foot immersion in the autumn. The finger temperatures during the pre-immersion period in the autumn tended to be lower than in other seasons. The finger temperatures during the pre-immersion period affected the temperature change of the finger during the immersion period. The rate of increase of the toe temperature and the foot temperature during post-immersion in the summer and the spring were greater than those in the autumn and winter. Oxygen consumption during the pre-immersion period in the autumn was significantly lower than in the other seasons (pCooling the feet caused no significant changes in the temperatures the cheek, forehead or forearm. The cheek temperature in the summer and autumn was cooler than corresponding temperatures taken in the winter and spring.

  15. Conducting field trials for frost tolerance breeding in cereals.

    Science.gov (United States)

    Cattivelli, Luigi

    2014-01-01

    Cereal species can be damaged by frost either during winter or at flowering stage. Frost tolerance per se is only a part of the mechanisms that allow the plants to survive during winter; winterhardiness also considers other biotic or physical stresses that challenge the plants during the winter season limiting their survival rate. While frost tolerance can also be tested in controlled environments, winterhardiness can be determined only with field evaluations. Post-heading frost damage occurs from radiation frost events in spring during the reproductive stages. A reliable evaluation of winterhardiness or of post-heading frost damage should be carried out with field trials replicated across years and locations to overcome the irregular occurrence of natural conditions which satisfactorily differentiate genotypes. The evaluation of post-heading frost damage requires a specific attention to plant phenology. The extent of frost damage is usually determined with a visual score at the end of the winter.

  16. Serological response to influenza vaccination among children vaccinated for multiple influenza seasons.

    Directory of Open Access Journals (Sweden)

    Sajjad Rafiq

    Full Text Available To evaluate if, among children aged 3 to 15 years, influenza vaccination for multiple seasons affects the proportion sero-protected.Participants were 131 healthy children aged 3-15 years. Participants were vaccinated with trivalent inactivated seasonal influenza vaccine (TIV over the 2005-06, 2006-07 and 2007-8 seasons. Number of seasons vaccinated were categorized as one (2007-08; two (2007-08 and 2006-07 or 2007-08 and 2005-06 or three (2005-06, 2006-07, and 2007-08. Pre- and post-vaccination sera were collected four weeks apart. Antibody titres were determined by hemagglutination inhibition (HAI assay using antigens to A/Solomon Islands/03/06 (H1N1, A/Wisconsin/67/05 (H3N2 and B/Malaysia/2506/04. The proportions sero-protected were compared by number of seasons vaccinated using cut-points for seroprotection of 1:40 vs. 1:320. The proportions of children sero-protected against H1N1 and H3N2 was high (>85% regardless of number of seasons vaccinated and regardless of cut-point for seroprotection. For B Malaysia there was no change in proportions sero-protected by number of seasons vaccinated; however the proportions protected were lower than for H1N1 and H3N2, and there was a lower proportion sero-protected when the higher, compared to lower, cut-point was used for sero-protection.The proportion of children sero-protected is not affected by number of seasons vaccinated.

  17. Study on seasonal IR signature change of a ship by considering seasonal marine environmental conditions

    Science.gov (United States)

    Kim, Do-Hwi; Han, Kuk-Il; Choi, Jun-Hyuk; Kim, Tae-Kuk

    2017-05-01

    Infrared (IR) signal emitted from objects over 0 degree Kelvin has been used to detect and recognize the characteristics of those objects. Recently more delicate IR sensors have been applied for various guided missiles and they affect a crucial influence on object's survivability. Especially, in marine environment it is more vulnerable to be attacked by IR guided missiles since there are nearly no objects for concealment. To increase the survivability of object, the IR signal of the object needs to be analyzed properly by considering various marine environments. IR signature of a naval ship consists of the emitted energy from ship surface and the reflected energy by external sources. Surface property such as the emissivity and the absorptivity on the naval ship varies with different paints applied on the surface and the reflected IR signal is also affected by the surface radiative property, the sensor's geometric position and various climatic conditions in marine environment. Since the direct measurement of IR signal using IR camera is costly and time consuming job, computer simulation methods are developing rapidly to replace those experimental tasks. In this study, we are demonstrate a way of analyzing the IR signal characteristics by using the measured background IR signals using an IR camera and the estimated target IR signals from the computer simulation to find the seasonal trends of IR threats of a naval ship. Through this process, measured weather data are used to analyze more accurate IR signal conditions for the naval ship. The seasonal change of IR signal contrast between the naval ship and the marine background shows that the highest contrast radiant intensity (CRI) value is appeared in early summer.

  18. An Overview of Seasonal Changes in Oxidative Stress and Antioxidant Defence Parameters in Some Invertebrate and Vertebrate Species.

    Science.gov (United States)

    Chainy, Gagan Bihari Nityananda; Paital, Biswaranjan; Dandapat, Jagneswar

    2016-01-01

    Antioxidant defence system, a highly conserved biochemical mechanism, protects organisms from harmful effects of reactive oxygen species (ROS), a by-product of metabolism. Both invertebrates and vertebrates are unable to modify environmental physical factors such as photoperiod, temperature, salinity, humidity, oxygen content, and food availability as per their requirement. Therefore, they have evolved mechanisms to modulate their metabolic pathways to cope their physiology with changing environmental challenges for survival. Antioxidant defences are one of such biochemical mechanisms. At low concentration, ROS regulates several physiological processes, whereas at higher concentration they are toxic to organisms because they impair cellular functions by oxidizing biomolecules. Seasonal changes in antioxidant defences make species able to maintain their correct ROS titre to take various physiological functions such as hibernation, aestivation, migration, and reproduction against changing environmental physical parameters. In this paper, we have compiled information available in the literature on seasonal variation in antioxidant defence system in various species of invertebrates and vertebrates. The primary objective was to understand the relationship between varied biological phenomena seen in different animal species and conserved antioxidant defence system with respect to seasons.

  19. An Overview of Seasonal Changes in Oxidative Stress and Antioxidant Defence Parameters in Some Invertebrate and Vertebrate Species

    Directory of Open Access Journals (Sweden)

    Gagan Bihari Nityananda Chainy

    2016-01-01

    Full Text Available Antioxidant defence system, a highly conserved biochemical mechanism, protects organisms from harmful effects of reactive oxygen species (ROS, a by-product of metabolism. Both invertebrates and vertebrates are unable to modify environmental physical factors such as photoperiod, temperature, salinity, humidity, oxygen content, and food availability as per their requirement. Therefore, they have evolved mechanisms to modulate their metabolic pathways to cope their physiology with changing environmental challenges for survival. Antioxidant defences are one of such biochemical mechanisms. At low concentration, ROS regulates several physiological processes, whereas at higher concentration they are toxic to organisms because they impair cellular functions by oxidizing biomolecules. Seasonal changes in antioxidant defences make species able to maintain their correct ROS titre to take various physiological functions such as hibernation, aestivation, migration, and reproduction against changing environmental physical parameters. In this paper, we have compiled information available in the literature on seasonal variation in antioxidant defence system in various species of invertebrates and vertebrates. The primary objective was to understand the relationship between varied biological phenomena seen in different animal species and conserved antioxidant defence system with respect to seasons.

  20. Seasonal Occurrence of Key Arthropod Pests and Beneficial Insects in Michigan High Tunnel and Field Grown Raspberries.

    Science.gov (United States)

    Leach, Heather; Isaacs, Rufus

    2018-06-06

    Berry crops are increasingly produced in high tunnels, which provide growers with the opportunity to extend their production season. This is particularly beneficial for the northern region of the United States with short and unpredictable growing seasons and where rainfall limits fruit quality. However, little is known about the effect of high tunnels on the community of pests, natural enemies, or pollinators, especially in berry crops, and there are few reports of the insect community in raspberries in this region. We compared the abundance of these insects during two growing seasons in field-grown and tunnel-grown floricane and primocane producing raspberries through direct observation and trapping at five sites in southwestern and central Michigan. We found eight key pests, including spotted wing Drosophila, leafhoppers, and thrips, and seven key natural enemies including parasitoid wasps, spiders, and lacewings, that were common across all sites. Pest populations were up to 6.6 times higher in tunnels, and pests typical of greenhouse systems became more dominant in this environment. Natural enemies observed on plants under tunnels were also more abundant than in the field, but this trend was reversed for natural enemies trapped on yellow sticky cards. There was also a reduction of both honey bees and wild bees under the high tunnels, which was balanced by use of commercial bumble bees. These data not only provide much-needed information on the phenology of the insect community on raspberry plantings, they also highlight the entomological implications of protected raspberry culture.

  1. An approach to quantify sources, seasonal change, and biogeochemical processes affecting metal loading in streams: Facilitating decisions for remediation of mine drainage

    Science.gov (United States)

    Kimball, B.A.; Runkel, R.L.; Walton-Day, K.

    2010-01-01

    Historical mining has left complex problems in catchments throughout the world. Land managers are faced with making cost-effective plans to remediate mine influences. Remediation plans are facilitated by spatial mass-loading profiles that indicate the locations of metal mass-loading, seasonal changes, and the extent of biogeochemical processes. Field-scale experiments during both low- and high-flow conditions and time-series data over diel cycles illustrate how this can be accomplished. A low-flow experiment provided spatially detailed loading profiles to indicate where loading occurred. For example, SO42 - was principally derived from sources upstream from the study reach, but three principal locations also were important for SO42 - loading within the reach. During high-flow conditions, Lagrangian sampling provided data to interpret seasonal changes and indicated locations where snowmelt runoff flushed metals to the stream. Comparison of metal concentrations between the low- and high-flow experiments indicated substantial increases in metal loading at high flow, but little change in metal concentrations, showing that toxicity at the most downstream sampling site was not substantially greater during snowmelt runoff. During high-flow conditions, a detailed temporal sampling at fixed sites indicated that Zn concentration more than doubled during the diel cycle. Monitoring programs must account for diel variation to provide meaningful results. Mass-loading studies during different flow conditions and detailed time-series over diel cycles provide useful scientific support for stream management decisions.

  2. MAGNETIC FIELD MEASUREMENTS FOR FAST-CHANGING MAGNETIC FIELDS

    International Nuclear Information System (INIS)

    2004-01-01

    Several recent applications for fast ramped magnets have been found that require rapid measurement of the field quality during the ramp. (In one instance, accelerator dipoles will be ramped at 1 T/sec, with measurements needed to the accuracy typically required for accelerators.) We have built and tested a new type of magnetic field measuring system to meet this need. The system consists of 16 stationary pickup windings mounted on a cylinder. The signals induced in the windings in a changing magnetic field are sampled and analyzed to obtain the field harmonics. To minimize costs, printed circuit boards were used for the pickup windings and a combination of amplifiers and ADPs used for the voltage readout system. New software was developed for the analysis. Magnetic field measurements of a model dipole developed for the SIS200 accelerator at GSI are presented. The measurements are needed to insure that eddy currents induced by the fast ramps do not impact the field quality needed for successful accelerator operation

  3. Seasonality and dietary requirements: will eating seasonal food contribute to health and environmental sustainability?

    Science.gov (United States)

    Macdiarmid, Jennie I

    2014-08-01

    Eating more seasonal food is one proposal for moving towards more sustainable consumption patterns, based on the assumption that it could reduce the environmental impact of the diet. The aim of the present paper is to consider the implications of eating seasonal food on the different elements of sustainability (i.e. health, economics, society), not just the environment. Seasonality can be defined as either globally seasonal (i.e. produced in the natural production season but consumed anywhere in the world) or locally seasonal (i.e. produced in the natural production season and consumed within the same climatic zone). The environmental, health, economic and societal impact varies by the definition used. Global seasonality has the nutritional benefit of providing a more varied and consistent supply of fresh produce year round, but this increases demand for foods that in turn can have a high environmental cost in the country of production (e.g. water stress, land use change with loss of biodiversity). Greenhouse gas emissions of globally seasonal food are not necessarily higher than food produced locally as it depends more on the production system used than transportation. Eating more seasonal food, however, is only one element of a sustainable diet and should not overshadow some of the potentially more difficult dietary behaviours to change that could have greater environmental and health benefits (e.g. reducing overconsumption or meat consumption). For future guidelines for sustainable diets to be realistic they will need to take into account modern lifestyles, cultural and social expectations in the current food environment.

  4. Propulsion Physics Under the Changing Density Field Model

    Science.gov (United States)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will requires new propulsion physics. Specifically a propulsion physics model that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. In 2004 Khoury and Weltman produced a density dependent cosmology theory they called Chameleon Cosmology, as at its nature, it is hidden within known physics. This theory represents a scalar field within and about an object, even in the vacuum. Whereby, these scalar fields can be viewed as vacuum energy fields with definable densities that permeate all matter; having implications to dark matter/energy with universe acceleration properties; implying a new force mechanism for propulsion physics. Using Chameleon Cosmology, the author has developed a new propulsion physics model, called the Changing Density Field (CDF) Model. This model relates to density changes in these density fields, where the density field density changes are related to the acceleration of matter within an object. These density changes in turn change how an object couples to the surrounding density fields. Whereby, thrust is achieved by causing a differential in the coupling to these density fields about an object. Since the model indicates that the density of the density field in an object can be changed by internal mass acceleration, even without exhausting mass, the CDF model implies a new propellant-less propulsion physics model

  5. Spectroscopic analysis of seasonal changes in live fuel moisture content and leaf dry mass

    Science.gov (United States)

    Yi Qi; Philip E. Dennison; W. Matt Jolly; Rachael C. Kropp; Simon C. Brewer

    2014-01-01

    Live fuel moisture content (LFMC), the ratio of water mass to dry mass contained in live plant material, is an important fuel property for determining fire danger and for modeling fire behavior. Remote sensing estimation of LFMC often relies on an assumption of changing water and stable dry mass over time. Fundamental understanding of seasonal variation in plant water...

  6. Sensor for detecting changes in magnetic fields

    Science.gov (United States)

    Praeg, Walter F.

    1981-01-01

    A sensor for detecting changes in the magnetic field of the equilibrium-field coil of a Tokamak plasma device comprises a pair of bifilar wires disposed circumferentially, one inside and one outside the equilibrium-field coil. Each is shorted at one end. The difference between the voltages detected at the other ends of the bifilar wires provides a measure of changing flux in the equilibrium-field coil. This difference can be used to detect faults in the coil in time to take action to protect the coil.

  7. Inferring Pre-shock Acoustic Field From Post-shock Pitot Pressure Measurement

    Science.gov (United States)

    Wang, Jian-Xun; Zhang, Chao; Duan, Lian; Xiao, Heng; Virginia Tech Team; Missouri Univ of Sci; Tech Team

    2017-11-01

    Linear interaction analysis (LIA) and iterative ensemble Kalman method are used to convert post-shock Pitot pressure fluctuations to static pressure fluctuations in front of the shock. The LIA is used as the forward model for the transfer function associated with a homogeneous field of acoustic waves passing through a nominally normal shock wave. The iterative ensemble Kalman method is then employed to infer the spectrum of upstream acoustic waves based on the post-shock Pitot pressure measured at a single point. Several test cases with synthetic and real measurement data are used to demonstrate the merits of the proposed inference scheme. The study provides the basis for measuring tunnel freestream noise with intrusive probes in noisy supersonic wind tunnels.

  8. Mongolians core gut microbiota and its correlation with seasonal dietary changes.

    Science.gov (United States)

    Zhang, Jiachao; Guo, Zhuang; Lim, Angela An Qi; Zheng, Yi; Koh, Eileen Y; Ho, Danliang; Qiao, Jianmin; Huo, Dongxue; Hou, Qiangchuan; Huang, Weiqiang; Wang, Lifeng; Javzandulam, Chimedsuren; Narangerel, Choijilsuren; Jirimutu; Menghebilige; Lee, Yuan-Kun; Zhang, Heping

    2014-05-16

    Historically, the Mongol Empire ranks among the world's largest contiguous empires, and the Mongolians developed their unique lifestyle and diet over thousands of years. In this study, the intestinal microbiota of Mongolians residing in Ulan Bator, TUW province and the Khentii pasturing area were studied using 454 pyrosequencing and q-PCR technology. We explored the impacts of lifestyle and seasonal dietary changes on the Mongolians' gut microbes. At the phylum level, the Mongolians's gut populations were marked by a dominance of Bacteroidetes (55.56%) and a low Firmicutes to Bacteroidetes ratio (0.71). Analysis based on the operational taxonomic unit (OTU) level revealed that the Mongolian core intestinal microbiota comprised the genera Prevotella, Bacteroides, Faecalibacterium, Ruminococcus, Subdoligranulum and Coprococcus. Urbanisation and life-style may have modified the compositions of the gut microbiota of Mongolians from Ulan Bator, TUW and Khentii. Based on a food frequency questionnaire, we found that the dietary structure was diverse and stable throughout the year in Ulan Bator and TUW, but was simple and varied during the year in Khentii. Accordingly, seasonal effects on intestinal microbiota were more distinct in Khentii residents than in TUW or Ulan Bator residents.

  9. Estimation of Evapotranspiration from Fields with and without Cover Crops Using Remote Sensing and in situ Methods

    Directory of Open Access Journals (Sweden)

    Christopher Hay

    2012-11-01

    Full Text Available Estimation of actual evapotranspiration (ETa based on remotely sensed imagery is very valuable in agricultural regions where ETa rates can vary greatly from field to field. This research utilizes the image processing model METRIC (Mapping Evapotranspiration at high Resolution with Internalized Calibration to estimate late season, post-harvest ETa rates from fields with a cover crop planted after a cash crop (in this case, a rye/radish/pea mixture planted after spring wheat. Remotely sensed EToF (unit-less fraction of grass-based reference ET, ETo maps were generated using Erdas Imagine software for a 260 km2 area in northeastern South Dakota, USA. Meteorological information was obtained from a Bowen-Ratio Energy Balance System (BREBS located within the image. Nine image dates were used for the growing season, from May through October. Five of those nine were captured during the cover crop season. METRIC was found to successfully differentiate between fields with and without cover crops. In a blind comparison, METRIC compared favorably with the estimated ETa rates found using the BREBS (ETλE, with a difference in total estimated ETa for the cover crop season of 7%.

  10. Studies on post-partum anoestrus in Alentejano beef cows

    International Nuclear Information System (INIS)

    Horta, A.E.M.; Vasques, M.I.; Leitao, R.M.; Robalo Silva, J.

    1990-01-01

    Post-partum ovarian activity in Alentejano beef cows maintained on natural pastures was monitored by measuring plasma progesterone levels using the radioimmunoassay method. Post-partum anoestrus was compared in cows calving in two different seasons (winter and summer). Differences between primiparous and multiparous cows, the effect of short term nursing interruption (72 hours by the 20th day post-partum) and the dam's body weight at calving (BWC) were also considered with respect to their influence on the onset of post-partum ovarian activity. Fertility after two breeding seasons of natural mating (April-May) and November-December) was also studied. Post-partum anoestrus was significantly longer in winter calving cows than in those calving in summer, in both multiparous and primiparous cows (73.9 versus 33.1 and 111.1 versus 35.6 days, respectively; P 2 =0.41; P<0.03). Because of a longer post-partum anoestrus, fertility was reduced in cows calving during the winter season compared with those calving in summer in all three years of the study (63.9 versus 76.9%, 57.8 versus 62.9% and 36.5 versus 60.6%, for 1984, 1985 and 1986, respectively). The results presented show that the winter period in Portugal impairs the return to ovarian activity post-partum in this breed. 19 refs, 2 figs, 4 tabs

  11. Seasonality in ocean microbial communities.

    Science.gov (United States)

    Giovannoni, Stephen J; Vergin, Kevin L

    2012-02-10

    Ocean warming occurs every year in seasonal cycles that can help us to understand long-term responses of plankton to climate change. Rhythmic seasonal patterns of microbial community turnover are revealed when high-resolution measurements of microbial plankton diversity are applied to samples collected in lengthy time series. Seasonal cycles in microbial plankton are complex, but the expansion of fixed ocean stations monitoring long-term change and the development of automated instrumentation are providing the time-series data needed to understand how these cycles vary across broad geographical scales. By accumulating data and using predictive modeling, we gain insights into changes that will occur as the ocean surface continues to warm and as the extent and duration of ocean stratification increase. These developments will enable marine scientists to predict changes in geochemical cycles mediated by microbial communities and to gauge their broader impacts.

  12. Seasonal Variation of Colored Dissolved Organic Matter in Barataria Bay, Louisiana, Using Combined Landsat and Field Data

    Directory of Open Access Journals (Sweden)

    Ishan Joshi

    2015-09-01

    Full Text Available Coastal bays, such as Barataria Bay, are important transition zones between the terrigenous and marine environments that are also optically complex due to elevated amounts of particulate and dissolved constituents. Monthly field data collected over a period of 15 months in 2010 and 2011 in Barataria Bay were used to develop an empirical band ratio algorithm for the Landsat-5 TM that showed a good correlation with the Colored Dissolved Organic Matter (CDOM absorption coefficient at 355 nm (ag355 (R2 = 0.74. Landsat-derived CDOM maps generally captured the major details of CDOM distribution and seasonal influences, suggesting the potential use of Landsat imagery to monitor biogeochemistry in coastal water environments. An investigation of the seasonal variation in ag355 conducted using Landsat-derived ag355 as well as field data suggested the strong influence of seasonality in the different regions of the bay with the marine end members (lower bay experiencing generally low but highly variable ag355 and the freshwater end members (upper bay experiencing high ag355 with low variability. Barataria Bay experienced a significant increase in ag355 during the freshwater release at the Davis Pond Freshwater Diversion (DPFD following the Deep Water Horizon oil spill in 2010 and following the Mississippi River (MR flood conditions in 2011, resulting in a weak linkage to salinity in comparison to the other seasons. Tree based statistical analysis showed the influence of high river flow conditions, high- and low-pressure systems that appeared to control ag355 by ~28%, 29% and 43% of the time duration over the study period at the marine end member just outside the bay. An analysis of CDOM variability in 2010 revealed the strong influence of the MR in controlling CDOM abundance in the lower bay during the high flow conditions, while strong winds associated with cold fronts significantly increase CDOM abundance in the upper bay, thus revealing the important

  13. Using bacterial and necrophagous insect dynamics for post-mortem interval estimation during cold season: Novel case study in Romania.

    Science.gov (United States)

    Iancu, Lavinia; Carter, David O; Junkins, Emily N; Purcarea, Cristina

    2015-09-01

    Considering the biogeographical characteristics of forensic entomology, and the recent development of forensic microbiology as a complementary approach for post-mortem interval estimation, the current study focused on characterizing the succession of necrophagous insect species and bacterial communities inhabiting the rectum and mouth cavities of swine (Sus scrofa domesticus) carcasses during a cold season outdoor experiment in an urban natural environment of Bucharest, Romania. We monitored the decomposition process of three swine carcasses during a 7 month period (November 2012-May 2013) corresponding to winter and spring periods of a temperate climate region. The carcasses, protected by wire cages, were placed on the ground in a park type environment, while the meteorological parameters were constantly recorded. The succession of necrophagous Diptera and Coleoptera taxa was monitored weekly, both the adult and larval stages, and the species were identified both by morphological and genetic characterization. The structure of bacterial communities from swine rectum and mouth tissues was characterized during the same time intervals by denaturing gradient gel electrophoresis (DGGE) and sequencing of 16S rRNA gene fragments. We observed a shift in the structure of both insect and bacterial communities, primarily due to seasonal effects and the depletion of the carcass. A total of 14 Diptera and 6 Coleoptera species were recorded on the swine carcasses, from which Calliphora vomitoria and C. vicina (Diptera: Calliphoridae), Necrobia violacea (Coleoptera: Cleridae) and Thanatophilus rugosus (Coleoptera: Silphidae) were observed as predominant species. The first colonizing wave, primarily Calliphoridae, was observed after 15 weeks when the temperature increased to 13°C. This was followed by Muscidae, Fanniidae, Anthomyiidae, Sepsidae and Piophilidae. Families belonging to Coleoptera Order were observed at week 18 when temperatures raised above 18°C, starting with

  14. Field-warmed soil carbon changes imply high 21st-century modeling uncertainty

    Directory of Open Access Journals (Sweden)

    K. Todd-Brown

    2018-06-01

    Full Text Available The feedback between planetary warming and soil carbon loss has been the focus of considerable scientific attention in recent decades, due to its potential to accelerate anthropogenic climate change. The soil carbon temperature sensitivity is traditionally estimated from short-term respiration measurements – either from laboratory incubations that are artificially manipulated or from field measurements that cannot distinguish between plant and microbial respiration. To address these limitations of previous approaches, we developed a new method to estimate soil temperature sensitivity (Q10 of soil carbon directly from warming-induced changes in soil carbon stocks measured in 36 field experiments across the world. Variations in warming magnitude and control organic carbon percentage explained much of field-warmed organic carbon percentage (R2  =  0.96, revealing Q10 across sites of 2.2 [1.6, 2.7] 95 % confidence interval (CI. When these field-derived Q10 values were extrapolated over the 21st century using a post hoc correction of 20 Coupled Model Intercomparison Project Phase 5 (CMIP5 Earth system model outputs, the multi-model mean soil carbon stock changes shifted from the previous value of 88 ± 153 Pg carbon (weighted mean ± 1 SD to 19 ± 155 Pg carbon with a Q10-driven 95 % CI of 248 ± 191 to −95 ± 209 Pg carbon. On average, incorporating the field-derived Q10 values into Earth system model simulations led to reductions in the projected amount of carbon sequestered in the soil over the 21st century. However, the considerable parameter uncertainty led to extremely high variability in soil carbon stock projections within each model; intra-model uncertainty driven by the field-derived Q10 was as great as that between model variation. This study demonstrates that data integration should capture the variation of the system, as well as mean trends.

  15. Transient magnetic field changes in flares

    International Nuclear Information System (INIS)

    Patterson, A.; Zirin, H.

    1981-01-01

    Magnetic changes have been detected with the videomagnetograph (VMG) at Big Bear during two large flares on 1979 November 5. Two kinds of changes were detected in both flares: a decrease in satellite field strength near the locus of the flare and the appearance of strong transient fields during the peak of the flare. We explain why we believe that the observed effects are real and not instrumental and discuss their significance for flare studies

  16. Seasonal Mass Changes in the Red Sea Observed By GPS and Grace

    Science.gov (United States)

    Alothman, A. O.; Fing, W.; Fernandes, R. M. S.; Bos, M. S.; Elsaka, B.

    2014-12-01

    The Red Sea is a semi-enclosed basin and exchanges water with the Gulf of Aden through the strait of Bab-el-Mandeb at the southern part of the sea. Its circulation is affected by the Indian Monsoon through its connection via the Gulf of Aden. Two distinctive (in summer and in winter) seasonal signals represent the water exchange. To understand the seasonal mass changes in the Red Sea, estimates of the mass changes based on two geodetic techniques are presented: from the Gravity Recovery and Climate Experiment (GRACE) and from the Global Navigation Satellite System (GNSS). The GRACE solutions were truncated up to spherical harmonic degree and order degree 60 to estimate the average monthly mass change in the atmosphere and ocean from models (several hours). GNSS solution is based on observations from four stations along the Red Sea that have been acquired in continuous mode starting in 2007 (having at least 5 years' data-span). The time series analysis of the observed GNSS vertical deformation of these sites has been analyzed. The results revealed that the GNSS observed vertical loading agrees with the atmospheric loading (ATML) assuming that the hydrological signal along the costs of the Red sea is negligible. Computed values of daily vertical atmospheric loading using the NCEP surface pressure data (Inverted Barometer IB) for the 4 stations for 2003 until 2013 are provided. Comparison of the GRACE and GNSS solutions has shown significant annual mass variations in the Red Sea (about 15 cm annual amplitude). After removing the atmospheric effect (ATML), the ocean loading can be observed by GNSS and GRACE estimates in the Red Sea.

  17. From Fall to Spring, or Spring to Fall? Seasonal Cholera Transmission Cycles and Implications for Climate Change

    Science.gov (United States)

    Akanda, A. S.; Jutla, A. S.; Huq, A.; Colwell, R.; Islam, S.; WE Reason

    2010-12-01

    Cholera remains a major public health threat in many developing countries around the world. The striking seasonality and the annual recurrence of this infectious disease in endemic areas continues to be of considerable interest to scientists and public health workers. Despite major advances in the ecological, and microbiological understanding of Vibrio cholerae, the causative agent, the role of underlying macro-scale hydroclimatic processes in propagating the disease in different seasons and years is not well understood. The incidence of cholera in the Bengal Delta region, the ‘native homeland’ of cholera, shows distinct biannual peaks in the southern floodplains, as opposed to single annual peaks in coastal areas and the northern parts of Bangladesh, as well as other cholera-endemic regions in the world. A coupled analysis of the regional hydroclimate and cholera incidence reveals a strong association of the spatio-temporal variability of incidence peaks with seasonal processes and extreme events. At a seasonal scale, the cycles indicate a spring-fall transmission pattern, contrary to the prevalent notion of a fall-spring transmission cycle. We show that the asymmetric seasonal hydroclimatology affects regional cholera dynamics by providing a coastal growth environment for bacteria in spring, while propagating transmission to fall by flooding. This seasonal interpretation of the progression of cholera has important implications, for formulating effective cholera intervention and mitigation efforts through improved water management and understanding the impacts of changing climate patterns on seasonal cholera transmission. (Water Environental Research Education Actionable Solutions Network)

  18. Amygdala response to emotional faces in seasonal affective disorder

    DEFF Research Database (Denmark)

    Borgsted, Camilla; Ozenne, Brice; Mc Mahon, Brenda

    2018-01-01

    BACKGROUND: Seasonal affective disorder (SAD) is characterized by seasonally recurring depression. Heightened amygdala activation to aversive stimuli is associated with major depressive disorder but its relation to SAD is unclear. We evaluated seasonal variation in amygdala activation in SAD......, we correlated change in symptom severity, assessed with The Hamilton Rating Scale for Depression - Seasonal Affective Disorder version (SIGH-SAD), with change in amygdala activation. RESULTS: We found no season-by-group, season or group effect on our aversive contrast. Independent of season, SAD...... of the presence of depressive symptoms....

  19. Impact of shade on outdoor thermal comfort—a seasonal field study in Tempe, Arizona

    Science.gov (United States)

    Middel, Ariane; Selover, Nancy; Hagen, Björn; Chhetri, Nalini

    2016-12-01

    Shade plays an important role in designing pedestrian-friendly outdoor spaces in hot desert cities. This study investigates the impact of photovoltaic canopy shade and tree shade on thermal comfort through meteorological observations and field surveys at a pedestrian mall on Arizona State University's Tempe campus. During the course of 1 year, on selected clear calm days representative of each season, we conducted hourly meteorological transects from 7:00 a.m. to 6:00 p.m. and surveyed 1284 people about their thermal perception, comfort, and preferences. Shade lowered thermal sensation votes by approximately 1 point on a semantic differential 9-point scale, increasing thermal comfort in all seasons except winter. Shade type (tree or solar canopy) did not significantly impact perceived comfort, suggesting that artificial and natural shades are equally efficient in hot dry climates. Globe temperature explained 51 % of the variance in thermal sensation votes and was the only statistically significant meteorological predictor. Important non-meteorological factors included adaptation, thermal comfort vote, thermal preference, gender, season, and time of day. A regression of subjective thermal sensation on physiological equivalent temperature yielded a neutral temperature of 28.6 °C. The acceptable comfort range was 19.1 °C-38.1 °C with a preferred temperature of 20.8 °C. Respondents exposed to above neutral temperature felt more comfortable if they had been in air-conditioning 5 min prior to the survey, indicating a lagged response to outdoor conditions. Our study highlights the importance of active solar access management in hot urban areas to reduce thermal stress.

  20. Methodological issues in assessing changes in costs pre- and post-medication switch: a schizophrenia study example

    Directory of Open Access Journals (Sweden)

    Nyhuis Allen W

    2009-05-01

    Full Text Available Abstract Background Schizophrenia is a severe, chronic, and costly illness that adversely impacts patients' lives and health care payer budgets. Cost comparisons of treatment regimens are, therefore, important to health care payers and researchers. Pre-Post analyses ("mirror-image", where outcomes prior to a medication switch are compared to outcomes post-switch, are commonly used in such research. However, medication changes often occur during a costly crisis event. Patients may relapse, be hospitalized, have a medication change, and then spend a period of time with intense use of costly resources (post-medication switch. While many advantages and disadvantages of Pre-Post methodology have been discussed, issues regarding the attributability of costs incurred around the time of medication switching have not been fully investigated. Methods Medical resource use data, including medications and acute-care services (hospitalizations, partial hospitalizations, emergency department were collected for patients with schizophrenia who switched antipsychotics (n = 105 during a 1-year randomized, naturalistic, antipsychotic cost-effectiveness schizophrenia trial. Within-patient changes in total costs per day were computed during the pre- and post-medication change periods. In addition to the standard Pre-Post analysis comparing costs pre- and post-medication change, we investigated the sensitivity of results to varying assumptions regarding the attributability of acute care service costs occurring just after a medication switch that were likely due to initial medication failure. Results Fifty-six percent of all costs incurred during the first week on the newly initiated antipsychotic were likely due to treatment failure with the previous antipsychotic. Standard analyses suggested an average increase in cost-per-day for each patient of $2.40 after switching medications. However, sensitivity analyses removing costs incurred post-switch that were potentially

  1. Seasonal changes in antioxidant enzyme activities of freshwater biofilms in a metal polluted Mediterranean stream.

    Science.gov (United States)

    Bonet, Berta; Corcoll, Natàlia; Acuňa, Vicenç; Sigg, Laura; Behra, Renata; Guasch, Helena

    2013-02-01

    While seasonal variations in fluvial communities have been extensively investigated, effects of seasonality on community responses to environmental and/or chemical stress are poorly documented. The aim of this study was to describe antioxidant enzyme activity (AEA) variability in fluvial biofilms over an annual cycle, under multi-stress scenarios due to environmental variability (e.g., light intensity, water flow, and temperature) and metal pollution (Zn, Mn and Fe). The annual monitoring study was performed at three sites according to their water and biofilm metal concentrations. Metal concentration was affected by water flow due to dilution. Low flow led to higher dissolved Zn concentrations, and thus to higher Zn accumulation in the biofilm. Water temperature, light intensity and phosphate concentration were the environmental factors which determined the seasonality of biofilm responses, whereas dissolved Zn and Zn accumulation in biofilms were the parameters linked to sites and periods of highest metal pollution. Community algal succession, from diatoms in cold conditions to green algae in warm conditions, was clearer in the non metal-polluted site than in those metal-polluted, presumably due to the selection pressure exerted by metals. Most AEA were related with seasonal environmental variability at the sites with low or no-metal pollution, except glutathione-S-transferase (GST) which was related with Zn (dissolved and accumulated in biofilm) pollution occurring at the most polluted site. We can conclude that seasonal variations of community composition and function are masked by metal pollution. From this study we suggest the use of a multi-biomarker approach, including AEA and a set of biological and physicochemical parameters as an effect-based field tool to assess metal pollution. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Identifying MRI markers to evaluate early treatment-related changes post-laser ablation for cancer pain management

    Science.gov (United States)

    Tiwari, Pallavi; Danish, Shabbar; Madabhushi, Anant

    2014-03-01

    Laser interstitial thermal therapy (LITT) has recently emerged as a new treatment modality for cancer pain management that targets the cingulum (pain center in the brain), and has shown promise over radio-frequency (RF) based ablation which is reported to provide temporary relief. One of the major advantages enjoyed by LITT is its compatibility with magnetic resonance imaging (MRI), allowing for high resolution in vivo imaging to be used in LITT procedures. Since laser ablation for pain management is currently exploratory and is only performed at a few centers worldwide, its short-, and long-term effects on the cingulum are currently unknown. Traditionally treatment effects are evaluated by monitoring changes in volume of the ablation zone post-treatment. However, this is sub-optimal since it involves evaluating a single global parameter (volume) to detect changes pre-, and post-MRI. Additionally, the qualitative observations of LITT-related changes on multi-parametric MRI (MPMRI) do not specifically address differentiation between the appearance of treatment related changes (edema, necrosis) from recurrence of the disease (pain recurrence). In this work, we explore the utility of computer extracted texture descriptors on MP-MRI to capture early treatment related changes on a per-voxel basis by extracting quantitative relationships that may allow for an in-depth understanding of tissue response to LITT on MRI, subtle changes that may not be appreciable on original MR intensities. The second objective of this work is to investigate the efficacy of different MRI protocols in accurately capturing treatment related changes within and outside the ablation zone post-LITT. A retrospective cohort of studies comprising pre- and 24-hour post-LITT 3 Tesla T1-weighted (T1w), T2w, T2-GRE, and T2-FLAIR acquisitions was considered. Our scheme involved (1) inter-protocol as well as inter-acquisition affine registration of pre- and post-LITT MRI, (2) quantitation of MRI parameters

  3. The effect of the holiday season on body weight and composition in college students

    Directory of Open Access Journals (Sweden)

    Hester Casey N

    2006-12-01

    Full Text Available Abstract Background With the rapid increase in obesity rates, determining critical periods for weight gain and the effects of changes in fat mass is imperative. The purpose of this study was to examine changes in body weight and composition over the holiday season (Thanksgiving through New Year's in male and female college students. Methods Subjects completed three visits: the first occurred within 2 weeks prior to Thanksgiving, the second occurred within 5 to 7 days following Thanksgiving, and the third occurred within 10 days following New Year's Day. A total of 82 healthy male and female college age subjects participated. Body composition by dual energy x-ray absorptiometry (DXA was assessed at visits 1 and 3 while body weight was assessed at all three visits. Results Average body weight remained relatively unchanged from pre-Thanksgiving to post-New Year's (71.3 ± 14 kg vs. 71.2 ± 15 kg; P = 0.71 and, in fact, a subset of normal weight subjects lost a significant amount of body weight. However, percent body fat (25.9 ± 9 %fat vs. 27.0 ± 9 %fat; P P P = 0.08 was not significantly different than the post-New Year's. A significant positive relationship (P P Conclusion Despite the fact that body weight remained unchanged over the course of the holiday season, a significant increase in %body fat and fat mass was observed. With recent evidence showing marked morbidity and mortality to be associated with increased body fat (particularly abdominal adiposity, results from this study suggest body weight alone may underestimate the potentially deleterious effects of the holiday season.

  4. HARD X-RAY EMISSION DURING FLARES AND PHOTOSPHERIC FIELD CHANGES

    International Nuclear Information System (INIS)

    Burtseva, O.; Petrie, G. J. D.; Pevtsov, A. A.; Martínez-Oliveros, J. C.

    2015-01-01

    We study the correlation between abrupt permanent changes of magnetic field during X-class flares observed by the Global Oscillation Network Group and Helioseismic and Magnetic Imager instruments, and the hard X-ray (HXR) emission observed by RHESSI, to relate the photospheric field changes to the coronal restructuring and investigate the origin of the field changes. We find that spatially the early RHESSI emission corresponds well to locations of the strong field changes. The field changes occur predominantly in the regions of strong magnetic field near the polarity inversion line (PIL). The later RHESSI emission does not correspond to significant field changes as the flare footpoints are moving away from the PIL. Most of the field changes start before or around the start time of the detectable HXR signal, and they end at about the same time or later than the detectable HXR flare emission. Some of the field changes propagate with speed close to that of the HXR footpoint at a later phase of the flare. The propagation of the field changes often takes place after the strongest peak in the HXR signal when the footpoints start moving away from the PIL, i.e., the field changes follow the same trajectory as the HXR footpoint, but at an earlier time. Thus, the field changes and HXR emission are spatio-temporally related but not co-spatial nor simultaneous. We also find that in the strongest X-class flares the amplitudes of the field changes peak a few minutes earlier than the peak of the HXR signal. We briefly discuss this observed time delay in terms of the formation of current sheets during eruptions

  5. Field response of aboveground non-target arthropod community to transgenic Bt-Cry1Ab rice plant residues in postharvest seasons.

    Science.gov (United States)

    Bai, Yao-Yu; Yan, Rui-Hong; Ye, Gong-Yin; Huang, Fangneng; Wangila, David S; Wang, Jin-Jun; Cheng, Jia-An

    2012-10-01

    Risk assessments of ecological effects of transgenic rice expressing lepidoptera-Cry proteins from Bacillus thuringiensis (Bt) on non-target arthropods have primarily focused on rice plants during cropping season, whereas few studies have investigated the effects in postharvest periods. Harvested rice fallow fields provide a critical over-wintering habitat for arthropods in the Chinese rice ecosystems, particularly in the southern region of the country. During 2006-08, two independent field trials were conducted in Chongqing, China to investigate the effects of transgenic Cry1Ab rice residues on non-target arthropod communities. In each trial, pitfall traps were used to sample arthropods in field plots planted with one non-Bt variety and two Bt rice lines expressing the Cry1Ab protein. Aboveground arthropods in the trial plots during the postharvest season were abundant, while community densities varied significantly between the two trials. A total of 52,386 individual insects and spiders, representing 93 families, was captured in the two trials. Predominant arthropods sampled were detritivores, which accounted for 91.9% of the total captures. Other arthropods sampled included predators (4.2%), herbivores (3.2%), and parasitoids (0.7%). In general, there were no significant differences among non-Bt and Bt rice plots in all arthropod community-specific parameters for both trials, suggesting no adverse impact of the Bt rice plant residues on the aboveground non-target arthropod communities during the postharvest season. The results of this study provide additional evidence that Bt rice is safe to non-target arthropod communities in the Chinese rice ecosystems.

  6. Comparison of Ant Community Diversity and Functional Group Composition Associated to Land Use Change in a Seasonally Dry Oak Forest.

    Science.gov (United States)

    Cuautle, M; Vergara, C H; Badano, E I

    2016-04-01

    Ants have been used to assess land use conversion, because they reflect environmental change, and their response to these changes have been useful in the identification of bioindicators. We evaluated ant diversity and composition associated to different land use change in a temperate forest (above 2000 m asl) in Mexico. The study was carried out in "Flor del Bosque" Park a vegetation mosaic of native Oak Forests and introduced Eucalyptus and grasslands. Species richness, dominance and diversity rarefaction curves, based on ant morphospecies and functional groups, were constructed and compared among the three vegetation types, for the rainy and the dry seasons of 2008-2009. Jaccard and Sorensen incidence-based indices were calculated to obtain similarity values among all the habitats. The Oak Forest was a rich dominant community, both in species and functional groups; the Eucalyptus plantation was diverse with low dominance. The most seasonality habitat was the grassland, with low species and high functional group diversity during the dry seasons, but the reverse pattern during the wet season. The Oak Forest was more similar to the Eucalyptus plantation than to the grassland, particularly during the dry season. Oak Forests are dominated by Cold Climate Specialists, specifically Prenolepis imparis (Say). The Eucalyptus and the grassland are characterized by generalized Myrmicinae, as Pheidole spp. and Monomorium ebenium (Forel). The conservation of the native Oak Forest is primordial for the maintenance of Cold Climate Specialist ant communities. The microclimatic conditions in this forest, probably, prevented the invasion by opportunistic species.

  7. Seasonal changes in the radiation balance of subarctic forest and tundra

    International Nuclear Information System (INIS)

    Lafleur, P.M.; Renzetti, A.V.; Bello, R.

    1993-01-01

    This paper examines the seasonal behavior of the components of the radiation budget of subarctic tundra and open forest near Churchill, Manitoba. Data were collected between late February and August 1990. The presence of the winter snowpack is the most important factor which affects the difference in radiation balances of tundra and forest. Overall, net radiation was about four to five times larger over the forest when snow covered the ground. Albedo differences were primarily responsible for this difference in net radiation; however, somewhat smaller net longwave losses were experienced at the tundra site. The step decrease in albedo from winter to summer (i.e. snow-covered to snow-free conditions) was significant at both sites. The forest albedo decreased by about three-fold while the tundra experienced a seven-fold decrease. Net radiation at both sites increased in direct response to the albedo change. Transmissivity of the atmosphere near Churchill also appeared to change at about the same time as the loss of the snow cover and may be related to changing air masses which bring about the final snow melt

  8. Coordination of improvement of higher education personnel: regulatory officer field of post-graduate studies in Brazil

    Directory of Open Access Journals (Sweden)

    Rogerio Junior Boratim

    2014-12-01

    Full Text Available This paper aims to present a sociological reflection on the role of the Coordination of Improvement of Higher Education Personnel (CAPES as the regulator that institutionalized the field of postgraduate studies in Brazil with public universities. The methodological and theoretical assumptions underpin the theory of the scientific field of Pierre Bourdieu and seek to demonstrate that the CAPES as a political entity linked to the federal government brokered and legitimized the involvement of the holders of teacher-researchers greater symbolic capital (scientific recognition among peers-competitors , giving them the prerogative to set rules for the evaluation and funding of post-graduate studies. Nevertheless, these legitimate borrowers (dominant in the field of post-graduate consolidated merit system amalgamated by one academic productivism, establishing universities within a performance culture that brings the trailer individualism, utilitarianism and the casualization of labor and relations in the university field.

  9. Changes in Projected Spatial and Seasonal Groundwater Recharge in the Upper Colorado River Basin.

    Science.gov (United States)

    Tillman, Fred D; Gangopadhyay, Subhrendu; Pruitt, Tom

    2017-07-01

    The Colorado River is an important source of water in the western United States, supplying the needs of more than 38 million people in the United States and Mexico. Groundwater discharge to streams has been shown to be a critical component of streamflow in the Upper Colorado River Basin (UCRB), particularly during low-flow periods. Understanding impacts on groundwater in the basin from projected climate change will assist water managers in the region in planning for potential changes in the river and groundwater system. A previous study on changes in basin-wide groundwater recharge in the UCRB under projected climate change found substantial increases in temperature, moderate increases in precipitation, and mostly periods of stable or slight increases in simulated groundwater recharge through 2099. This study quantifies projected spatial and seasonal changes in groundwater recharge within the UCRB from recent historical (1950 to 2015) through future (2016 to 2099) time periods, using a distributed-parameter groundwater recharge model with downscaled climate data from 97 Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections. Simulation results indicate that projected increases in basin-wide recharge of up to 15% are not distributed uniformly within the basin or throughout the year. Northernmost subregions within the UCRB are projected an increase in groundwater recharge, while recharge in other mainly southern subregions will decline. Seasonal changes in recharge also are projected within the UCRB, with decreases of 50% or more in summer months and increases of 50% or more in winter months for all subregions, and increases of 10% or more in spring months for many subregions. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  10. Performance changes in NBA basketball players vary in starters vs. nonstarters over a competitive season.

    Science.gov (United States)

    Gonzalez, Adam M; Hoffman, Jay R; Rogowski, Joseph P; Burgos, William; Manalo, Edwin; Weise, Keon; Fragala, Maren S; Stout, Jeffrey R

    2013-03-01

    The purpose of this study was to compare starters (S) with nonstarters (NS), on their ability to maintain strength, power, and quickness during a competitive National Basketball Association (NBA) season. Twelve NBA players were assessed at the beginning and end of the competitive season. However, because of trades and injury, only 7 (S = 4, NS = 3) players (28.2 ± 3.4 years; 200.9 ± 9.4 cm; 104.7 ± 13.9 kg; 7.2 ± 1.9% body fat) participated in both testing sessions and underwent analysis. Anthropometric performance (repetitive vertical jump power [VJP], squat power [SQT power], and reaction time) and subjective feelings of energy, focus, alertness, and fatigue were recorded during each testing session. Results were interpreted using magnitude-based statistics to make inferences on true differences between starters and nonstarters using the unequal variances t-statistic. Starters played an average of 27.8 ± 6.9 minutes per game and nonstarters played an average of 11.3 ± 7.0 minutes per game. During the course of the season, changes in VJP indicated that starters were likely to increase VJP (Δ = 77.3 ± 78.1 W) compared to nonstarters (Δ= -160.0 ± 151.0 W). There also appeared to be a possible beneficial effect on maintaining reaction time in starters (Δ = 0.005 ± 0.074 seconds) compared with nonstarters (Δ = 0.047 ± 0.073 seconds). In addition, no clear differences in ΔSQT power were seen between starters (Δ = 110.8 ± 141.4 W) and nonstarters (Δ = 143.5 ± 24.7 W). Changes in subjective feelings of energy indicated that starters were very likely to maintain their energy over the course of a season. It also appeared possible that starters were able to have a more positive response to subjective measures of fatigue and alertness than nonstarters, with only trivial differences between starters and nonstarters in regards to maintaining focus. Results of this study suggest that NBA players may enhance lower-body power, repetitive jump ability, and

  11. Seasonal and Annual Survival of East-Atlantic Pale-Bellied Brent Geese Branta hrota Assessed by Capture-Recapture Analysis

    DEFF Research Database (Denmark)

    Clausen, P.; Frederiksen, M.; Percival, S. M.

    2001-01-01

    areas by intensive field studies. In this paper we use standard capture-recapture analysis to investigate seasonal and annual survival rates of the population. We divided the year into three periods with different spatial distribution of the geese, autumn (September-December), winter (Jan...... spring to autumn (0.982 MSR), -resulting in an overall annual survival rate of 0.870. We discuss the variation in seasonal and annual mortality rates in relation to constraints faced by the birds such as seasonal changes in availability of food resources, severe winters, long-distance migration...

  12. Seasonal and long-term changes in pH in the Dutch coastal zone

    Directory of Open Access Journals (Sweden)

    P. Provoost

    2010-11-01

    Full Text Available Recent observations and modelling studies suggest that biogeochemical changes can mask atmospheric CO2-induced pH decreases. Data collected by the Dutch monitoring authorities in different coastal systems (North Sea, Wadden Sea, Ems-Dollard, Eastern Scheldt and Scheldt estuary since 1975 provide an excellent opportunity to test whether this is the case in the Dutch coastal zone. The time-series were analysed using Multi-Resolution Analysis (MRA which resulted in the identification of system-dependent patterns on both seasonal and intra-annual time scales. The observed rates of pH change greatly exceed those expected from enhanced CO2 uptake, thus suggesting that other biogeochemical processes, possibly related to changes in nutrient loading, can play a dominant role in ocean acidification.

  13. Phenological mismatch in coastal western Alaska may increase summer season greenhouse gas uptake

    Science.gov (United States)

    Kelsey, Katharine C.; Leffler, A. Joshua; Beard, Karen H.; Choi, Ryan T.; Schmutz, Joel A.; Welker, Jeffery M.

    2018-04-01

    High latitude ecosystems are prone to phenological mismatches due to climate change- driven advances in the growing season and changing arrival times of migratory herbivores. These changes have the potential to alter biogeochemical cycling and contribute to feedbacks on climate change by altering greenhouse gas (GHG) emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) through large regions of the Arctic. Yet the effects of phenological mismatches on gas fluxes are currently unexplored. We used a three-year field experiment that altered the start of the growing season and timing of grazing to investigate how phenological mismatch affects GHG exchange. We found early grazing increased mean GHG emission to the atmosphere despite lower CH4 emissions due to grazing-induced changes in vegetation structure that increased uptake of CO2. In contrast, late grazing reduced GHG emissions because greater plant productivity led to an increase in CO2 uptake that overcame the increase in CH4 emission. Timing of grazing was an important control on both CO2 and CH4 emissions, and net GHG exchange was the result of opposing fluxes of CO2 and CH4. N2O played a negligible role in GHG flux. Advancing the growing season had a smaller effect on GHG emissions than changes to timing of grazing in this study. Our results suggest that a phenological mismatch that delays timing of grazing relative to the growing season, a change which is already developing along in western coastal Alaska, will reduce GHG emissions to the atmosphere through increased CO2 uptake despite greater CH4 emissions.

  14. Phenological mismatch in coastal western Alaska may increase summer season greenhouse gas uptake

    Science.gov (United States)

    Kelsey, Katharine C.; Leffler, A. Joshua; Beard, Karen H.; Choi, Ryan T.; Schmutz, Joel A.; Welker, Jeffery M.

    2018-01-01

    High latitude ecosystems are prone to phenological mismatches due to climate change- driven advances in the growing season and changing arrival times of migratory herbivores. These changes have the potential to alter biogeochemical cycling and contribute to feedbacks on climate change by altering greenhouse gas (GHG) emissions of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) through large regions of the Arctic. Yet the effects of phenological mismatches on gas fluxes are currently unexplored. We used a three-year field experiment that altered the start of the growing season and timing of grazing to investigate how phenological mismatch affects GHG exchange. We found early grazing increased mean GHG emission to the atmosphere despite lower CH4 emissions due to grazing-induced changes in vegetation structure that increased uptake of CO2. In contrast, late grazing reduced GHG emissions because greater plant productivity led to an increase in CO2 uptake that overcame the increase in CH4 emission. Timing of grazing was an important control on both CO2 and CH4 emissions, and net GHG exchange was the result of opposing fluxes of CO2 and CH4. N2O played a negligible role in GHG flux. Advancing the growing season had a smaller effect on GHG emissions than changes to timing of grazing in this study. Our results suggest that a phenological mismatch that delays timing of grazing relative to the growing season, a change which is already developing along in western coastal Alaska, will reduce GHG emissions to the atmosphere through increased CO2 uptake despite greater CH4 emissions.

  15. Seasonal timing in a warming world : Plasticity of seasonal timing of growth and reproduction

    NARCIS (Netherlands)

    Salis, Lucia

    2015-01-01

    In seasonal environments the timing of various biological processes is crucial for growth, survival and reproductive success of an individual. Nowadays, rapid large-scale climate change is altering species’ seasonal timing (phenology) in many eco¬systems. In this thesis Lucia Salis focuses on the

  16. Boll weevil within season and off-season activity monitored using a pheromone-and-glue reusable tube trap

    Directory of Open Access Journals (Sweden)

    Robério Carlos dos Santos Neves

    Full Text Available ABSTRACT: The boll weevil colonizes cotton fields as early as cotton squaring, causing significant losses due to feeding and protected development inside fruiting structures throughout crop phenology. Successful control depends on control of adults and their accurate detection when they colonize the crops. The commercial trap and boll weevil attract-and-control tubes (BWACT are the only available tools to monitor and attract-and-kill boll weevil, despite limitation in efficacy, and insecticide in BWACT is not allowed in organic production. A grandlure-and-glue reusable and insecticide-free tube (GGT made with polyvinyl chloride tube, smeared with entomological glue, and lured with pheromone was tested to detect boll weevil activity across various seasons. Boll weevil showed activity during growing season and off-season from 2009 to 2012 in the Semiarid and with higher numbers captured in GGT in comparisons to commercial traps. GGT was able to detect early weevils in the field right after planting. Further, the overall averages resulted in 34-, 16.8-, and 7.5-times more weevils captured in GGTs compared to the traps during stalk destruction in the Semiarid 2011 and Cerrado season 2012/13 and during the harvesting period in the Cerrado season 2011/12, respectively. Therefore, boll weevils were captured actively during season and off-season and early captures obtained in GGT compared to traps showed a better correlation between captures and square damage.

  17. Parametrized post-Newtonian approximation and Rastall's gravitational field equations

    International Nuclear Information System (INIS)

    Smalley, L.L.

    1978-01-01

    The parametrized post-Newtonian (PPN) approximation is generalized to accomodate Rastall's modification of Einstein's theory of gravity, which allows nonzero divergence of the energy-momentum tensor. Rastall's theory is then shown to have consistent field equations, gauge conditions, and the correct Newtonian limit of the equations of motion. The PPN parameters are obtained and shown to agree experimentally with those for the Einstein theory. In light of the nonzero divergence condition, integral conservation laws are investigated and shown to yield conserved energy-momentum and angular-momentum. We conclude that the above generalization of metric theories, within the PPN framework, is a natural extension of the concept of metric theories

  18. Metallogenic hydrothermal solution system of post volcanic magma in Xiangshan ore field

    International Nuclear Information System (INIS)

    Xu Hengli; Shao Fei; Zou Maoqin

    2009-01-01

    This paper has systematically described uranium metallogenic characteristics of Xiangshan ore field.Sources of metallogenic materials are discussed in different temporal and spatial scale. Combining with background analysis of metallogenic tectonic-magmatic-geodynamics, formation and evolution of metallogenic hydrothermal solution system in Xiangshan volcanic basin are studied. Metallogenic hydrothermal solution system in Xiangshan ore field is considered as the objective product of systematic evolution of hydrothermal solution in post volcanic magma constrained by regional tectonic environment. In time scale, metallogenic hydrothermal solution system developed for about 50 Ma, but its active spaces varied in different time domains. So temporal and spatial distribution of uranium mineralization is constrained. Further exploration for the ore field is also suggested in this paper. (authors)

  19. Quantifying seasonal velocity at Khumbu Glacier, Nepal

    Science.gov (United States)

    Miles, E.; Quincey, D. J.; Miles, K.; Hubbard, B. P.; Rowan, A. V.

    2017-12-01

    While the low-gradient debris-covered tongues of many Himalayan glaciers exhibit low surface velocities, quantifying ice flow and its variation through time remains a key challenge for studies aimed at determining the long-term evolution of these glaciers. Recent work has suggested that glaciers in the Everest region of Nepal may show seasonal variability in surface velocity, with ice flow peaking during the summer as monsoon precipitation provides hydrological inputs and thus drives changes in subglacial drainage efficiency. However, satellite and aerial observations of glacier velocity during the monsoon are greatly limited due to cloud cover. Those that do exist do not span the period over which the most dynamic changes occur, and consequently short-term (i.e. daily) changes in flow, as well as the evolution of ice dynamics through the monsoon period, remain poorly understood. In this study, we combine field and remote (satellite image) observations to create a multi-temporal, 3D synthesis of ice deformation rates at Khumbu Glacier, Nepal, focused on the 2017 monsoon period. We first determine net annual and seasonal surface displacements for the whole glacier based on Landsat-8 (OLI) panchromatic data (15m) processed with ImGRAFT. We integrate inclinometer observations from three boreholes drilled by the EverDrill project to determine cumulative deformation at depth, providing a 3D perspective and enabling us to assess the role of basal sliding at each site. We additionally analyze high-frequency on-glacier L1 GNSS data from three sites to characterize variability within surface deformation at sub-seasonal timescales. Finally, each dataset is validated against repeat-dGPS observations at gridded points in the vicinity of the boreholes and GNSS dataloggers. These datasets complement one another to infer thermal regime across the debris-covered ablation area of the glacier, and emphasize the seasonal and spatial variability of ice deformation for glaciers in High

  20. Tilted hexagonal post arrays: DNA electrophoresis in anisotropic media.

    Science.gov (United States)

    Chen, Zhen; Dorfman, Kevin D

    2014-02-01

    Using Brownian dynamics simulations, we show that DNA electrophoresis in a hexagonal array of micron-sized posts changes qualitatively when the applied electric field vector is not coincident with the lattice vectors of the array. DNA electrophoresis in such "tilted" post arrays is superior to the standard "un-tilted" approach; while the time required to achieve a resolution of unity in a tilted post array is similar to an un-tilted array at a low-electric field strengths, this time (i) decreases exponentially with electric field strength in a tilted array and (ii) increases exponentially with electric field strength in an un-tilted array. Although the DNA dynamics in a post array are complicated, the electrophoretic mobility results indicate that the "free path," i.e. the average distance of ballistic trajectories of point-sized particles launched from random positions in the unit cell until they intersect the next post, is a useful proxy for the detailed DNA trajectories. The analysis of the free path reveals a fundamental connection between anisotropy of the medium and DNA transport therein that goes beyond simply improving the separation device. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Ergosterol and Water Changes in Tricholoma matsutake Soil Colony during the Mushroom Fruiting Season

    Science.gov (United States)

    Lee, Dong-Hee; Park, Young-Woo; Lee, Young-Nam; Ka, Kang-Hyun; Park, Hyun; Bak, Won-Chull

    2009-01-01

    The purpose of this study is to understand spatio-temporal changes of active fungal biomass and water in Tricholoma matsutake soil colonies during the mushroom fruiting season. The active fungal biomass was estimated by analyzing ergosterol content at four different points within four replicated locations in a single circular T. matsutake colony at Ssanggok valley in the Sogri Mt. National Park in Korea during 2003 to 2005. The four points were the ahead of the colony, the front edge of the colony and 20 cm and 40 cm back from the front edge of the colony. Ergosterol content was 0.0 to 0.7 µg per gram dried soil at the ahead, 2.5 to 4.8 µg at the front edge, 0.5 to 1.8 µg at the 20 cm back and 0.3 to 0.8 µg at the 40 cm back. The ergosterol content was very high at the front edge where the T. matsutake hyphae were most active. However, ergosterol content did not significantly change during the fruiting season, September to October. Soil water contents were lower at the front edge and 20 cm back from the front edge of the colony than at the ahead and 40 cm back during the fruiting season. Soil water content ranged from 12 to 19% at the ahead, 10 to 11% at the edge, 9 to 11% at the 20 cm back and 11 to 15% at the 40 cm back. Our results suggest that the active front edge of the T. matsutake soil colony could be managed in terms of water relation and T. matsutake ectomycorrhizal root development. PMID:23983500

  2. Evaluation of post fire changes in soil properties and influence on the hydrological and erosive dynamics in a Mediterranean watershed

    Science.gov (United States)

    Sanz, Inés; Aguilar, Cristina; Millares, Agustín

    2013-04-01

    In the last fifty years, forest fires and changes in land use and management practices have had a significant influenceon the evolution of soil loss processes in the Mediterranean area. Forest fires have immediate effects in hydrological processes mainly due to sudden changes in soil properties and vegetation cover. After a fire there is an increase in runoff processes and peak flows and thus in the amount and composition of the sediments produced. Silting in dams downstream is often reported so the description of the post-fire hydrological processes is crucial in order to optimize decision making. This study analyzes a micro-watershed of 25 ha in the south of Spain that suffered a fire in October 2010 burning around a 2 km2 area. As the erosive processes in this area are directly related to concentrated overland flow, an indirect assessment of soil loss is presented in this work based on evaluating changes in runoff in Mediterranean post-fire situations. For this, the study is divided into two main parts. Firstly, changes in soil properties and vegetation cover are evaluated. Secondly, the effects of these changes in the hydrological and erosive dynamics are assessed.The watershed had been monitored in previous studies so soil properties and the vegetation cover before the fire took place were already characterized. Besides, the hydrological response was also available through an already calibrated and validated physically-based distributed hydrological model. For the evaluation of soil properties, field measurement campaigns were designed. Philip Dunne's tests for the determination of saturated hydraulic conductivity, as well as moisture content and bulk density measurements were carried out in both unaltered and burned soil samples. Changes in the vegetation cover fraction were assessed through desktop analysis of Landsat-TM5 platform satellite images as well as through visual inspection in the field campaigns. The analysis of the hydraulic conductivity revealed

  3. Seasonal trend analysis and ARIMA modeling of relative humidity and wind speed time series around Yamula Dam

    Science.gov (United States)

    Eymen, Abdurrahman; Köylü, Ümran

    2018-02-01

    Local climate change is determined by analysis of long-term recorded meteorological data. In the statistical analysis of the meteorological data, the Mann-Kendall rank test, which is one of the non-parametrical tests, has been used; on the other hand, for determining the power of the trend, Theil-Sen method has been used on the data obtained from 16 meteorological stations. The stations cover the provinces of Kayseri, Sivas, Yozgat, and Nevşehir in the Central Anatolia region of Turkey. Changes in land-use affect local climate. Dams are structures that cause major changes on the land. Yamula Dam is located 25 km northwest of Kayseri. The dam has huge water body which is approximately 85 km2. The mentioned tests have been used for detecting the presence of any positive or negative trend in meteorological data. The meteorological data in relation to the seasonal average, maximum, and minimum values of the relative humidity and seasonal average wind speed have been organized as time series and the tests have been conducted accordingly. As a result of these tests, the following have been identified: increase was observed in minimum relative humidity values in the spring, summer, and autumn seasons. As for the seasonal average wind speed, decrease was detected for nine stations in all seasons, whereas increase was observed in four stations. After the trend analysis, pre-dam mean relative humidity time series were modeled with Autoregressive Integrated Moving Averages (ARIMA) model which is statistical modeling tool. Post-dam relative humidity values were predicted by ARIMA models.

  4. Seasonal changes in the human alteration of fire regimes beyond the climate forcing

    Science.gov (United States)

    Fréjaville, Thibaut; Curt, Thomas

    2017-03-01

    Human activities have altered fire regimes for millennia by suppressing or enhancing natural fire activity. However, whether these anthropogenic pressures on fire activity have exceeded and will surpass climate forcing still remains uncertain. We tested if, how and the extent to which seasonal fire activity in southern France has recently (1976-2009) deviated from climate-expected trends. The latter were simulated using an ensemble of detrended fire-climate models. We found both seasonal and regional contrasts in climatic effects through a mixture of drought-driven and fuel-limited fire regimes. Dry contemporary conditions chiefly drove fire frequency and burned area, although higher fire activity was related to wetter conditions in the last three years. Surprisingly, the relative importance of preceding wet conditions was higher in winter than in summer, illustrating the strong potential dependency of regional fire-climate relationships on the human use and control of fires. In the Mediterranean mountains, warm winters and springs favour extensive fires in the following dry summer. These results highlight that increasing dryness with climate change could have antagonistic effects on fire regime by leading to larger fires in summer (moisture-limited), but lower fire activity in winter (fuel-limited fire regime). Furthermore, fire trends have significantly diverged from climatic expectations, with a strong negative alteration in fire activity in the Mediterranean lowlands and the summer burned area in the mountains. In contrast, alteration of winter fire frequency in the Mediterranean and Temperate mountains has shifted from positive to negative (or null) trends during the mid-1990s, a period when fire suppression policy underwent major revisions. Our findings demonstrate that changes in land-use and fire suppression policy have probably exceeded the strength of climate change effects on changing fire regime in southern Europe, making regional predictions of future

  5. Acute post-exercise change in blood pressure and exercise training response in patients with coronary artery disease

    Directory of Open Access Journals (Sweden)

    Antti M Kiviniemi

    2015-01-01

    Full Text Available We tested the hypothesis that acute post-exercise change in blood pressure (BP may predict exercise training responses in BP in patients with coronary artery disease (CAD. Patients with CAD (n=116, age 62±5 years, 85 men underwent BP assessments at rest and during 10-min recovery following a symptom-limited exercise test before and after the 6-month training intervention (one strength and 3-4 aerobic moderate-intensity exercises weekly. Post-exercise change in systolic BP (SBP was calculated by subtracting resting SBP from lowest post-exercise SBP. The training-induced change in resting SBP was -2±13 mmHg (p=0.064, ranging from -42 to 35 mmHg. Larger post-exercise decrease in SBP and baseline resting SBP predicted a larger training-induced decrement in SBP (β=0.46 and β=-0.44, respectively, p<0.001 for both. Acute post-exercise decrease in SBP provided additive value to baseline resting SBP in the prediction of training-induced change in resting SBP (R squared from 0.20 to 0.26, p=0.002. After further adjustments for other potential confounders (sex, age, baseline body mass index, realized training load, post-exercise decrease in SBP still predicted the training response in resting SBP (β=0.26, p=0.015. Acute post-exercise change in SBP was associated with training-induced change in resting SBP in patients with CAD, providing significant predictive information beyond baseline resting SBP.

  6. Characterisation of the metabolome of ocular tissues and post-mortem changes in the rat retina.

    Science.gov (United States)

    Tan, Shi Z; Mullard, Graham; Hollywood, Katherine A; Dunn, Warwick B; Bishop, Paul N

    2016-08-01

    Time-dependent post-mortem biochemical changes have been demonstrated in donor cornea and vitreous, but there have been no published studies to date that objectively measure post-mortem changes in the retinal metabolome over time. The aim of the study was firstly, to investigate post-mortem, time-dependent changes in the rat retinal metabolome and secondly, to compare the metabolite composition of healthy rat ocular tissues. To study post-mortem changes in the rat retinal metabolome, globes were enucleated and stored at 4 °C and sampled at 0, 2, 4, 8, 24 and 48 h post-mortem. To study the metabolite composition of rat ocular tissues, eyes were dissected immediately after culling to isolate the cornea, lens, vitreous and retina, prior to storing at -80 °C. Tissue extracts were subjected to Gas Chromatograph Mass Spectrometry (GC-MS) and Ultra High Performance Liquid Chromatography Mass Spectrometry (UHPLC-MS). Generally, the metabolic composition of the retina was stable for 8 h post-mortem when eyes were stored at 4 °C, but showed increasing changes thereafter. However, some more rapid changes were observed such as increases in TCA cycle metabolites after 2 h post-mortem, whereas some metabolites such as fatty acids only showed decreases in concentration from 24 h. A total of 42 metabolites were identified across the ocular tissues by GC-MS (MSI level 1) and 2782 metabolites were annotated by UHPLC-MS (MSI level 2) according to MSI reporting standards. Many of the metabolites detected were common to all of the tissues but some metabolites showed partitioning between different ocular structures with 655, 297, 93 and 13 metabolites being uniquely detected in the retina, lens, cornea and vitreous respectively. Only a small percentage (1.6%) of metabolites found in the vitreous were only detected in the retina and not other tissues. In conclusion, mass spectrometry-based techniques have been used for the first time to compare the metabolic composition of

  7. Seasonal superoxide overproduction and endothelial activation in guinea-pig heart; seasonal oxidative stress in rats and humans.

    Science.gov (United States)

    Konior, Anna; Klemenska, Emilia; Brudek, Magdalena; Podolecka, Ewa; Czarnowska, Elżbieta; Beręsewicz, Andrzej

    2011-04-01

    Seasonality in endothelial dysfunction and oxidative stress was noted in humans and rats, suggesting it is a common phenomenon of a potential clinical relevance. We aimed at studying (i) seasonal variations in cardiac superoxide (O(2)(-)) production in rodents and in 8-isoprostane urinary excretion in humans, (ii) the mechanism of cardiac O(2)(-) overproduction occurring in late spring/summer months in rodents, (iii) whether this seasonal O(2)(-)-overproduction is associated with a pro-inflammatory endothelial activation, and (iv) how the summer-associated changes compare to those caused by diabetes, a classical cardiovascular risk factor. Langendorff-perfused guinea-pig and rat hearts generated ~100% more O(2)(-), and human subjects excreted 65% more 8-isoprostane in the summer vs. other seasons. Inhibitors of NADPH oxidase, xanthine oxidase, and NO synthase inhibited the seasonal O(2)(-)-overproduction. In the summer vs. other seasons, cardiac NADPH oxidase and xanthine oxidase activity, and protein expression were increased, the endothelial NO synthase and superoxide dismutases were downregulated, and, in guinea-pig hearts, adhesion molecules upregulation and the endothelial glycocalyx destruction associated these changes. In guinea-pig hearts, the summer and a streptozotocin-induced diabetes mediated similar changes, yet, more severe endothelial activation associated the diabetes. These findings suggest that the seasonal oxidative stress is a common phenomenon, associated, at least in guinea-pigs, with the endothelial activation. Nonetheless, its biological meaning (regulatory vs. deleterious) remains unclear. Upregulated NADPH oxidase and xanthine oxidase and uncoupled NO synthase are the sources of the seasonal O(2)(-)-overproduction. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Avian population consequences of climate change are most severe for long-distance migrants in seasonal habitats.

    NARCIS (Netherlands)

    Both, C.; Turnhout, van C.A.M.; Bijlsma, R.G.; Siepel, H.; Strien, van A.J.; Foppen, R.P.B.

    2010-01-01

    One consequence of climate change is an increasing mismatch between timing of food requirements and food availability. Such a mismatch is primarily expected in avian long-distance migrants because of their complex annual cycle, and in habitats with a seasonal food peak. Here we show that

  9. Avian population consequences of climate change are most severe for long-distance migrants in seasonal habitats

    NARCIS (Netherlands)

    Both, Christiaan; Van Turnhout, Chris A. M.; Bijlsma, Rob G.; Siepel, Henk; Van Strien, Arco J.; Foppen, Ruud P. B.

    2010-01-01

    One consequence of climate change is an increasing mismatch between timing of food requirements and food availability. Such a mismatch is primarily expected in avian long-distance migrants because of their complex annual cycle, and in habitats with a seasonal food peak. Here we show that

  10. Impact of shade on outdoor thermal comfort-a seasonal field study in Tempe, Arizona.

    Science.gov (United States)

    Middel, Ariane; Selover, Nancy; Hagen, Björn; Chhetri, Nalini

    2016-12-01

    Shade plays an important role in designing pedestrian-friendly outdoor spaces in hot desert cities. This study investigates the impact of photovoltaic canopy shade and tree shade on thermal comfort through meteorological observations and field surveys at a pedestrian mall on Arizona State University's Tempe campus. During the course of 1 year, on selected clear calm days representative of each season, we conducted hourly meteorological transects from 7:00 a.m. to 6:00 p.m. and surveyed 1284 people about their thermal perception, comfort, and preferences. Shade lowered thermal sensation votes by approximately 1 point on a semantic differential 9-point scale, increasing thermal comfort in all seasons except winter. Shade type (tree or solar canopy) did not significantly impact perceived comfort, suggesting that artificial and natural shades are equally efficient in hot dry climates. Globe temperature explained 51 % of the variance in thermal sensation votes and was the only statistically significant meteorological predictor. Important non-meteorological factors included adaptation, thermal comfort vote, thermal preference, gender, season, and time of day. A regression of subjective thermal sensation on physiological equivalent temperature yielded a neutral temperature of 28.6 °C. The acceptable comfort range was 19.1 °C-38.1 °C with a preferred temperature of 20.8 °C. Respondents exposed to above neutral temperature felt more comfortable if they had been in air-conditioning 5 min prior to the survey, indicating a lagged response to outdoor conditions. Our study highlights the importance of active solar access management in hot urban areas to reduce thermal stress.

  11. Urban Cholera and Water Sustainability Challenges under Climatic and Anthropogenic Change

    Science.gov (United States)

    Akanda, A. S.; Jutla, A.; Huq, A.; Faruque, A. G.; Colwell, R. R.

    2013-12-01

    The last three decades of surveillance data shows a drastic increase of cholera prevalence in the largest cholera-endemic city of the world - Dhaka, Bangladesh. Emerging megacities in the developing world, especially those located in coastal regions of the tropics remain vulnerable to similar. However, there has not been any systematic study on linking the long-term disease trends with changes in related climatic, environmental, or societal variables. Here, we analyze the 30-year dynamics of urban cholera prevalence in Dhaka with changes in climatic or societal factors: regional hydrology, flooding, water usage, changes in distribution systems, population growth and density in urban settlements, as well as shifting climate patterns. An interesting change is observed in the seasonal trends of cholera incidence; while an endemic upward trend is seen in the dry season, the post-monsoon trend seem to be more epidemic in nature. Evidence points to growing urbanization and rising population in unplanned settlements that have negligible to poor water and sanitation systems compounded by increasing frequency of record flood events. Growing water scarcity in the dry season and lack of sustainable water and sanitation infrastructure for urban settlements have increased endemicity of spring outbreaks, while record flood events and prolonged post-monsoon inundation have contributed to increased epidemic outbreaks in fall. We analyze our findings with the World Health Organization recommended guidelines and investigate water sustainability challenges in the context of climatic and anthropogenic changes in the region.

  12. Spinning gravitating objects in the effective field theory in the post-Newtonian scheme

    Energy Technology Data Exchange (ETDEWEB)

    Levi, Michele [Université Pierre et Marie Curie-Paris VI, CNRS-UMR 7095,Institut d’Astrophysique de Paris, 98 bis Boulevard Arago, 75014 Paris (France); Sorbonne Universités, Institut Lagrange de Paris,98 bis Boulevard Arago, 75014 Paris (France); Steinhoff, Jan [Max-Planck-Institute for Gravitational Physics (Albert-Einstein-Institute),Am Mühlenberg 1, 14476 Potsdam-Golm (Germany); Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Universidade de Lisboa,Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal)

    2015-09-30

    We introduce a formulation for spinning gravitating objects in the effective field theory in the post-Newtonian scheme in the context of the binary inspiral problem. We aim at an effective action, where all field modes below the orbital scale are integrated out. We spell out the relevant degrees of freedom, in particular the rotational ones, and the associated symmetries. Building on these symmetries, we introduce the minimal coupling part of the point particle action in terms of gauge rotational variables, and construct the spin-induced nonminimal couplings, where we obtain the leading order couplings to all orders in spin. We specify the gauge for the rotational variables, where the unphysical degrees of freedom are eliminated already from the Feynman rules, and all the orbital field modes are integrated out. The equations of motion of the spin can be directly obtained via a proper variation of the action, and Hamiltonians may be straightforwardly derived. We implement this effective field theory for spin to derive all spin dependent potentials up to next-to-leading order to quadratic level in spin, namely up to the third post-Newtonian order for rapidly rotating compact objects. In particular, the proper next-to-leading order spin-squared potential and Hamiltonian for generic compact objects are also derived. For the implementations we use the nonrelativistic gravitational field decomposition, which is found here to eliminate higher-loop Feynman diagrams also in spin dependent sectors, and facilitates derivations. This formulation for spin is thus ideal for treatment of higher order spin dependent sectors.

  13. Length-Weight Realtionship and Seasonal Distrubition of Magalaspis cordyla (Linnaeus 1758 fish Size frequency Variation from Karachi Coast

    Directory of Open Access Journals (Sweden)

    Quratulan AHMED

    2013-09-01

    Full Text Available The study of seasonal variation in distribution of 167 fishes of magalaspis cordyla from the Karachi fish harbour collected seasonally (pre-monsoon, mon-soon, post-monsoon between September 2011-August 2012. The highest catch of fish (68 was recorded in pre-monsoon season and the lowest catch of fish (47 was recorded in monsoon season. The highest mean length (38.6+ 0.746 and weight (288+ 21.90 was measured during pre-monsoon season and lowest mean length (22.5+ 0.671 and weight (120.5+ 2.73 was measured during mon-soon season. The highest mean condition factor (1.192+ 0.817 and minimum (0.500+ 0.038 was recorded in pre-monsoon season. Fish estimated negative and positive allometric growth because b values larger and less then 3 in pre-monsoon and monsoon season but post-monsoon season showed positive allometric growth because b value larger then 3 in all size classes

  14. Morphological changes connected with irradiation of large fields in dogs and with the effect of automyelotransplantation

    International Nuclear Information System (INIS)

    Klestova, O.V.; Sil'chenko, N.N.; Stanzhevskaya, T.I.; Strelin, G.S.; Vishnyakov, Yu.S.; Gubareva, A.V.; Skripkina, N.S.

    1983-01-01

    Dogs have been used to study the effect of automyelotransplantation on processes of post-radiation recovery of hemopoietic organs in large-field fractionated irradiation and morphological changes in some internal organs irradiated with different doses. Dogs of both sexes were irradiated in the gamma device twice a week alternately from the back and from the stomach with fractions of 8 Gy for the radiation field. The integral dose for all irradiated sections is 48 Gy. Automyelotransplantation of bone marrow is done after irradiation of the upper part of the body of the animal. Morphological changes in bone marrow, spleen, gastrointestinal tract, liver, heart and lungs, are found. It is shown that automyelotransplantation from non-irradiated section in the case of large-field radiation promotes the recovery of bone marrow and other homopoietic organs which is expressed in the intensification of repopulation of bone marrow of breast bone and lymphoid hemopoiesis in spleen. It is noted that such reparation of bone marrow can play a positive role in the recovery of bone marrow syndrome of radiation disease

  15. Short-term community dynamics in seasonal and hyperseasonal cerrados

    Directory of Open Access Journals (Sweden)

    MV. Cianciaruso

    Full Text Available In South America, the largest seasonal savanna region is the Brazilian cerrado. Our aim was to study temporal changes in some community descriptors, such as floristic composition, richness, species density, plant density, and cylindrical volume, in a seasonal cerrado, comparing it to a nearby hyperseasonal cerrado. In four different seasons, we placed randomly ten 1 m² quadrats in each vegetation form and sampled all the vascular plants. Seasonal changes in floristic composition, species density, and plant density were less pronounced in the seasonal than in the hyperseasonal cerrado. Floristic similarity between the vegetation forms was lower when the hyperseasonal cerrado was waterlogged. Richness and species density were higher in the seasonal cerrado, which reached its biomass peak at mid rainy season. The hyperseasonal cerrado, in turn, reached its biomass peak at early rainy season and, despite the waterlogging, maintained it until late rainy season. In the hyperseasonal cerrado, waterlogging acts as an environmental filter restricting the number of cerrado species able to withstand it. The seasonal cerrado community was more stable than the hyperseasonal one. Our results corroborated the idea that changes in the environmental filters will affect floristic composition and community structure in savannas.

  16. Role of PPARα in the Control of Torpor through FGF21-NPY Pathway: From Circadian Clock to Seasonal Change in Mammals

    Directory of Open Access Journals (Sweden)

    Norio Ishida

    2009-01-01

    Full Text Available In nature, hibernating animals encounter fasting, cold temperature and short day seasonally. Torpor is a state of decreased physiological activity in an animal, usually characterized by a reduced body temperature and rate of metabolism to adapt such a severe environment. Ablation of the central clock synchronizer, the suprachiasmatic nucleus in brain, abolishes torpor, a hibernation-like state, implicating the circadian clock involved in this seasonal change. Biologists knows well the energy source of daily heterotherms/hibernators changed from glucose to lipids in winter. Here we review several lines of evidence of a master transcriptional regulator in lipid catabolism, PPARα, in the control of torpor through FGF21-NPY pathway. This indicate the importance of circadian—and photoperiod—regulation of PPARα to tell seasons in our body.

  17. Genomic analysis of post-mating changes in the honey bee queen (Apis mellifera

    Directory of Open Access Journals (Sweden)

    Richard Freddie-Jeanne

    2008-05-01

    Full Text Available Abstract Background The molecular mechanisms underlying the post-mating behavioral and physiological transitions undergone by females have not been explored in great detail. Honey bees represent an excellent model system in which to address these questions because they exhibit a range of "mating states," with two extremes (virgins and egg-laying, mated queens that differ dramatically in their behavior, pheromone profiles, and physiology. We used an incompletely-mated mating-state to understand the molecular processes that underlie the transition from a virgin to a mated, egg-laying queen. We used same-aged virgins, queens that mated once but did not initiate egg-laying, and queens that mated once and initiated egg-laying. Results Differences in the behavior and physiology among groups correlated with the underlying variance observed in the top 50 predictive genes in the brains and the ovaries. These changes were correlated with either a behaviorally-associated pattern or a physiologically-associated pattern. Overall, these results suggest that the brains and the ovaries of queens are uncoupled or follow different timescales; the initiation of mating triggers immediate changes in the ovaries, while changes in the brain may require additional stimuli or take a longer time to complete. Comparison of our results to previous studies of post-mating changes in Drosophila melanogaster identified common biological processes affected by mating, including stress response and alternative-splicing pathways. Comparison with microarray data sets related to worker behavior revealed no obvious correlation between genes regulated by mating and genes regulated by behavior/physiology in workers. Conclusion Studying the underlying molecular mechanisms of post-mating changes in honey bee queens will not only give us insight into how molecular mechanisms regulate physiological and behavioral changes, but they may also lead to important insights into the evolution of

  18. Global patterns in post-dispersal seed removal by invertebrates and vertebrates.

    Science.gov (United States)

    Peco, Begoña; Laffan, Shawn W; Moles, Angela T

    2014-01-01

    It is commonly accepted that species interactions such as granivory are more intense in the tropics. However, this has rarely been tested. A global dataset of post-dispersal seed removal by invertebrates and vertebrates for 79 native plant species from semi-natural and natural terrestrial habitats ranging from 55° N to 45° S, was compiled from the global literature to test the hypothesis that post-dispersal seed removal by invertebrates and vertebrates is more intense at lower latitudes. We also quantified the relationship between post-dispersal seed removal by vertebrates and by invertebrates to global climatic features including temperature, actual evapotranspiration (AET) and rainfall seasonality. Linear mixed effect models were applied to describe the relationships between seed removal and latitude, hemisphere and climatic variables controlling for the effect of seed mass. Post-dispersal seed removal by invertebrates was negatively related to latitude. In contrast, post-dispersal seed removal by vertebrates was positively but weakly related to latitude. Mean annual temperature and actual evapotranspiration were positively related to post-dispersal seed removal by invertebrates, but not to post-dispersal seed removal by vertebrates, which was only marginally negatively related to rainfall seasonality. The inclusion of seed mass improved the fit of all models, but the term for seed mass was not significant in any model. Although a good climatic model for predicting post-dispersal seed predation by vertebrates at the global level was not found, our results suggest different and opposite latitudinal patterns of post-dispersal seed removal by invertebrates vs vertebrates. This is the first time that a negative relationship between post-dispersal seed removal by invertebrates and latitude, and a positive relationship with temperature and AET have been documented at a global-scale. These results have important implications for understanding global patterns in plant

  19. Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

    Directory of Open Access Journals (Sweden)

    Lourdes Gallego-Calvo

    2015-12-01

    Full Text Available Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001. No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05. After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05. These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer.

  20. Seasonal changes in reproductive activity, sperm variables and sperm freezability in Blanca Andaluza bucks

    Energy Technology Data Exchange (ETDEWEB)

    Gallego-Calvo, L.; Gatica, M.C.; Santiago-Moreno, J.; Guzmán, J.L.; Zarazaga, L.

    2015-07-01

    Interest in the preservation of endangered breeds such as the Blanca Andaluza goat, has increased and some steps should be therefore taken to ensure it. The study was designed to determine the seasonal reproductive pattern of Blanca Andaluza bucks, and whether this affects the quality of their semen and its freezability over the year. Seven bucks were used and their body weight, testicular weight, plasma testosterone concentration and fresh sperm quality determined every week. The collected sperm was cryopreserved and stored; it was then thawed and the same sperm quality variables measured every fortnight. High plasma testosterone concentrations were recorded during the summer and autumn, and low concentrations were recorded during winter and spring (p<0.001). No differences were seen between seasons in terms of the percentage of bucks ejaculating, the percentage of active bucks, or ejaculate volume. However, the sperm concentration, the total number of sperm per ejaculate, and the values for most fresh sperm variables were lower during the winter period (at least p<0.05). After freezing-thawing, the quality of winter-collected sperm was better, in some respects, than that of summer-collected sperm (at least p<0.05). These results reveal that Blanca Andaluza bucks show seasonal reproductive activity in terms of their plasma testosterone concentration, but no clear change in their sexual behaviour between seasons was observed. The values of fresh sperm variables also vary over the year, reaching their lowest during winter. However, after freezing-thawing, winter-collected sperm is of overall better quality than sperm collected during the summer. (Author)

  1. Validation of the Danish-language psychological well-being-post-traumatic changes questionnaire

    DEFF Research Database (Denmark)

    la Cour, Peter; Sternhagen Nielsen, Anni Brit; Andersen, Soren Bo

    2016-01-01

    The Psychological Well-Being–Post-Traumatic Changes Questionnaire (PWB-PTCQ) is an 18-item self-report measure for assessing perceived changes in psychological well-being following traumatic events. The aim of the study was to translate, adapt, and test a Danish-language version of the questionna...... with the psychological distress measures; the PWB-PTCQ did not correlate, whereas the PTGI correlated positively. The Danish-language version of the PWB-PTCQ is found valid and reliable.......The Psychological Well-Being–Post-Traumatic Changes Questionnaire (PWB-PTCQ) is an 18-item self-report measure for assessing perceived changes in psychological well-being following traumatic events. The aim of the study was to translate, adapt, and test a Danish-language version...... of the questionnaire and to compare the measure with the Posttraumatic Growth Inventory (PTGI). The PWB-PTCQ, the PTGI, and scales measuring psychological distress were administered to 290 soldiers a mean of 8 months after they returned from deployment. The psychometric properties of the PWB-PTCQ were satisfactory...

  2. Effects of thermal vapor diffusion on seasonal dynamics of water in the unsaturated zone

    Science.gov (United States)

    Milly, Paul C.D.

    1996-01-01

    The response of water in the unsaturated zone to seasonal changes of temperature (T) is determined analytically using the theory of nonisothermal water transport in porous media, and the solutions are tested against field observations of moisture potential and bomb fallout isotopic (36Cl and 3H) concentrations. Seasonally varying land surface temperatures and the resulting subsurface temperature gradients induce thermal vapor diffusion. The annual mean vertical temperature gradient is close to zero; however, the annual mean thermal vapor flux is downward, because the temperature‐dependent vapor diffusion coefficient is larger, on average, during downward diffusion (occurring at high T) than during upward diffusion (low T). The annual mean thermal vapor flux is shown to decay exponentially with depth; the depth (about 1 m) at which it decays to e−1of its surface value is one half of the corresponding decay depth for the amplitude of seasonal temperature changes. This depth‐dependent annual mean flux is effectively a source of water, which must be balanced by a flux divergence associated with other transport processes. In a relatively humid environment the liquid fluxes greatly exceed the thermal vapor fluxes, so such a balance is readily achieved without measurable effect on the dynamics of water in the unsaturated zone. However, if the mean vertical water flux through the unsaturated zone is very small (theoretical prediction is supported by long‐term field measurements in the Chihuahuan Desert. The analysis also makes predictions, confirmed by the field observations, regarding the seasonal variations of matric potential at a given depth. The conceptual model of unsaturated zone water transport developed here implies the possibility of near‐surface trapping of any aqueous constituent introduced at the surface.

  3. Seasonal response of biomass growth and allocation of a boreal bioenergy crop (Phalaris arundinacea L.) to climate change

    Energy Technology Data Exchange (ETDEWEB)

    Chang Zhang

    2013-06-01

    in the growing season. Compared to CON, ET and ETC increased LMF and SMF, and decreased RMF over the whole growing season under NW and HW. Under LW, ET and ETC decreased LMF and increased RMF throughout the growing season, and increased SMF in early periods and then decreased later in the growing season. EC decreased the LMF and SMF and increased the RMF over the growing season but did not significantly affect the seasonal biomass allocation pattern between plant organs. The LMF was higher and the RMF was lower throughout the growing season in response to the higher groundwater level, while the effect of groundwater level on the SMF depended on the developmental phase of the plants. Our results show that climatic treatments affected biomass growth and biomass allocation to each of the three plant organs, while the direction and extent of climate-related changes in biomass growth and allocation depended on the availability of groundwater. The influence of groundwater level appeared to be crucial for the carbon gain regarding the production of RCG biomass for energy purposes and the concurrent sequestration of carbon in soils under changing climates in the mire sites used to cultivate RCG. (orig.)

  4. Longitudinal and seasonal changes in functional organization of macroinvertebrate communities in four Oregon streams.

    OpenAIRE

    Hawkins, C. P.; Sedell, J. R.

    1981-01-01

    Relative numerical dominance and densities of invertebrate functional feeding groups are compared with longitudinal and seasonal changes in food resources in a Cascade Range stream system in Oregon. We also compare our data with hypothetical predictions of the River Continuum model. We found that both relative abundances and densities of functional groups fit qualitative characterization of stream reaches and the River Continuum model: Shredders dominated upper shaded reaches; scrapers were m...

  5. Effect of climate change on seasonal monsoon in Asia and its impact on the variability of monsoon rainfall in Southeast Asia

    Directory of Open Access Journals (Sweden)

    Yen Yi Loo

    2015-11-01

    Full Text Available Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment. Although there are enough historical evidence to support the theory that climate change is a natural phenomenon, many research scientists are widely in agreement that the increase in temperature in the 20th century is anthropologically related. The associated effects are the variability of rainfall and cyclonic patterns that are being observed globally. In Southeast Asia the link between global warming and the seasonal atmospheric flow during the monsoon seasons shows varying degree of fuzziness. This study investigates the impact of climate change on the seasonality of monsoon Asia and its effect on the variability of monsoon rainfall in Southeast Asia. The comparison of decadal variation of precipitation and temperature anomalies before the 1970s found general increases which were mostly varying. But beyond the 1970s, global precipitation anomalous showed increases that almost corresponded with increases in global temperature anomalies for the same period. There are frequent changes and a shift westward of the Indian summer monsoon. Although precipitation is observed to be 70% below normal levels, in some areas the topography affects the intensity of rainfall. These shifting phenomenon of other monsoon season in the region are impacting on the variability of rainfall and the onset of monsoons in Southeast Asia and is predicted to delay for 15 days the onset of the monsoon in the future. The variability of monsoon rainfall in the SEA region is observed to be decadal and the frequency and intensity of intermittent flooding of some areas during the monsoon season have serious consequences on the human, financial, infrastructure and food security of the region.

  6. Note on field trials of a new prototype solar still

    Energy Technology Data Exchange (ETDEWEB)

    Anand, S P

    1977-01-01

    Observations on field trials of a prototype still, of modified design, with respect to the quantity and quality of the fresh water obtained are reported. An average yield of 3.6 liters/m/sup 2//day of fresh water was obtained during the post-monsoon season and winter months. Traces of dissolved copper, zinc and iron were observed in the distilled water and the causes of metallic contamination are discussed. 10 references.

  7. [Characteristics and adaptation of seasonal drought in southern China under the background of climate change. V. Seasonal drought characteristics division and assessment in southern China].

    Science.gov (United States)

    Huang, Wan-Hua; Sui, Yue; Yang, Xiao-Guang; Dai, Shu-Wei; Li, Mao-Song

    2013-10-01

    Zoning seasonal drought based on the study of drought characteristics can provide theoretical basis for formulating drought mitigation plans and improving disaster reduction technologies in different arid zones under global climate change. Based on the National standard of meteorological drought indices and agricultural drought indices and the 1959-2008 meteorological data from 268 meteorological stations in southern China, this paper analyzed the climatic background and distribution characteristics of seasonal drought in southern China, and made a three-level division of seasonal drought in this region by the methods of combining comprehensive factors and main factors, stepwise screening indices, comprehensive disaster analysis, and clustering analysis. The first-level division was with the annual aridity index and seasonal aridity index as the main indices and with the precipitation during entire year and main crop growing season as the auxiliary indices, dividing the southern China into four primary zones, including semi-arid zone, sub-humid zone, humid zone, and super-humid zone. On this basis, the four primary zones were subdivided into nine second-level zones, including one semi-arid area-temperate-cold semi-arid hilly area in Sichuan-Yunnan Plateau, three sub-humid areas of warm sub-humid area in the north of the Yangtze River, warm-tropical sub-humid area in South China, and temperate-cold sub-humid plateau area in Southwest China, three humid areas of temperate-tropical humid area in the Yangtze River Basin, warm-tropical humid area in South China, and warm humid hilly area in Southwest China, and two super-humid areas of warm-tropical super-humid area in South China and temperate-cold super-humid hilly area in the south of the Yangtze River and Southwest China. According to the frequency and intensity of multiple drought indices, the second-level zones were further divided into 29 third-level zones. The distribution of each seasonal drought zone was

  8. Species biogeography predicts drought responses in a seasonally dry tropical forest

    Science.gov (United States)

    Schwartz, N.; Powers, J. S.; Vargas, G.; Xu, X.; Smith, C. M.; Brodribb, T.; Werden, L. K.; Becknell, J.; Medvigy, D.

    2017-12-01

    The timing, distribution, and amount of rainfall in the seasonal tropics have shifted in recent years, with consequences for seasonally dry tropical forests (SDTF). SDTF are sensitive to changing rainfall regimes and drought conditions, but sensitivity to drought varies substantially across species. One potential explanation of species differences is that species that experience dry conditions more frequently throughout their range will be better able to cope with drought than species from wetter climates, because species from drier climates will be better adapted to drought. An El-Niño induced drought in 2015 presented an opportunity to assess species-level differences in mortality in SDTF, and to ask whether the ranges of rainfall conditions species experience and the average rainfall regimes in species' ranges predict differences in mortality rates in Costa Rican SDTF. We used field plot data from northwest Costa Rica to determine species' level mortality rates. Mortality rates ranged substantially across species, with some species having no dead individuals to as high as 50% mortality. To quantify rainfall conditions across species' ranges, we used species occurrence data from the Global Biodiversity Information Facility, and rainfall data from the Chelsa climate dataset. We found that while the average and range of mean annual rainfall across species ranges did not predict drought-induced mortality in the field plots, across-range averages of the seasonality index, a measure of rainfall seasonality, was strongly correlated with species-level drought mortality (r = -0.62, p < 0.05), with species from more strongly seasonal climates experiencing less severe drought mortality. Furthermore, we found that the seasonality index was a stronger predictor of mortality than any individual functional trait we considered. This result shows that species' biogeography may be an important factor for how species will respond to future drought, and may be a more integrative

  9. How does harvest size vary with hunting season length?

    DEFF Research Database (Denmark)

    Sunde, Peter; Asferg, Tommy

    2014-01-01

    season length (population management/ethical/other). In non-sedentary species, changes in bag size correlated positively with changes in season length (overall response: b = 0.54, 95%CI: 0.14-0.95): reducing the hunting season to 50% of its initial length would on average result in a 31% reduction (95...

  10. Land use and land use change effects on nitrous oxide emissions in the seasonally dry ecosystems of Zimbabwe

    DEFF Research Database (Denmark)

    Nyamadzawo, G; Chirinda, Ngoni; Mapanda, F

    2012-01-01

    . The savanna woodlands cover over 95% of Zimbabwe’s forest area, and are divided into five woodland types: Acacia, miombo, mopane, teak (Baikiaea Plurijuga) and Terminalia-Combretaceae. This review is aimed at exploring the effects of land-use changes and land management practices on N2O emissions in Zimbabwe...... emissions were mainly concentrated in the wet season as N2O production is strongly enhanced by high soil moisture. During the dry season pyrogenic emissions were also important sources of N2O, contributing, an estimated 6.7 Gg N2O annually. Land use change in the form of biomass burning and conversion...... of emissions of N2O. Land-use change from savanna to agricultural production results in an immediate increase in N2O emissions. However, the emissions will decrease with time. The current estimates are associated with large uncertainties, thus, there is need for more detailed studies on the effects of land-use...

  11. Changes in the status of harvested rice fields in the Sacramento Valley, California: Implications for wintering waterfowl.

    Science.gov (United States)

    Miller, Michael R.; Garr, Jay D.; Coates, Peter S.

    2010-01-01

    Harvested rice fields provide critical foraging habitat for wintering waterfowl in North America, but their value depends upon post-harvest treatments. We visited harvested ricefields in the Sacramento Valley, California, during the winters of 2007 and 2008 (recent period) and recorded their observed status as harvested (standing or mechanically modified stubble), burned, plowed, or flooded. We compared these data with those from identical studies conducted during the 1980s (early period). We documented substantial changes in field status between periods. First, the area of flooded rice increased 4-5-fold, from about 15% to >40% of fields, because of a 3-4-fold increase in the percentage of fields flooded coupled with a 37-41% increase in the area of rice produced. Concurrently, the area of plowed fields increased from 35% of fields, burned fields declined from about 40% to 1%, and fields categorized as harvested declined from 22-54% to rice field status survey in the Sacramento Valley and other North American rice growing regions as appropriate to support long-term monitoring programs and wetland habitat conservation planning for wintering waterfowl.

  12. The Impact of Internal Wave Seasonality on the Continental Shelf Energy Budget

    Science.gov (United States)

    Wihsgott, Juliane U.; Sharples, Jonathan; Hopkins, Joanne; Palmer, Matthew R.; Mattias Green, J. A.

    2017-04-01

    Heating-stirring models are widely used to simulate the timing and strength of stratification in continental shelf environments. Such models are based on bulk potential energy (PE) budgets: the loss of PE due to thermal stratification is balanced by wind and tidal mixing. The model often fails to accurately predict the observed vertical structure, as it only considers forces acting on the surface and bottom boundary of the water column. This highlights the need for additional internal energy sources to close this budget, and produce an accurate seasonal cycle of stratification. We present new results that test the impact of boundary layer and internal wave forcing on stratification and vertical density structure in continental shelves. A new series of continuous measurements of full water depth vertical structure, dynamics and meteorological data spanning 17 months (March'14-July'15) provide unprecedented coverage over a full seasonal cycle at a station 120 km north-east from the continental shelf break. We observe a highly variable but energetic internal wave field from the onset of stratification that suggests a continuous supply of internal PE. The heating-stirring model reproduces bulk characteristics of the seasonal cycle. While it accurately predicts the timing of the onset in spring and peak stratification in late summer there is a persistent 20 J m-3 positive offset between the model and observations throughout this period. By including a source of internal energy in the model we improve the prediction for the strength of stratification and the vertical distribution of heat. Yet a constant source of PE seems to result in a seasonal discrepancy resulting in too little mixing during strong stratification and too much mixing during transient periods. The discrepancy seen in the model is consistent with the seasonality observed in the internal wave field. We will establish the role that changing stratification (N2) exerts on the internal wave field and vice

  13. Seasonal timing in a warming world : plasticity of seasonal timing of growth and reproduction

    OpenAIRE

    Salis, L.

    2015-01-01

    In seasonal environments the timing of various biological processes is crucial for growth, survival and reproductive success of an individual. Nowadays, rapid large-scale climate change is altering species’ seasonal timing (phenology) in many eco¬systems. In this thesis Lucia Salis focuses on the study of seasonal timing in the food chain of the oak-winter moth-great tit. As temperature increased over the last decades, both phenologies of the host plant, the oak, and the herbivorous insect, t...

  14. Evaluating FDG uptake changes between pre and post therapy respiratory gated PET scans

    International Nuclear Information System (INIS)

    Aristophanous, Michalis; Yong, Yue; Yap, Jeffrey T.; Killoran, Joseph H.; Allen, Aaron M.; Berbeco, Ross I.; Chen, Aileen B.

    2012-01-01

    Purpose: Whole body (3D) and respiratory gated (4D) FDG-PET/CT scans performed pre-radiotherapy (pre-RT) and post-radiotherapy (post-RT) were analyzed to investigate the impact of 4D PET in evaluating 18F-fluorodeoxyglucose (FDG) uptake changes due to therapy, relative to traditional 3D PET. Methods and materials: 3D and 4D sequential FDG-PET/CT scans were acquired pre-RT and approximately one month post-RT for patients with non-small cell lung cancer (NSCLC). The lesions of high uptake targeted with radiotherapy were identified on the pre-RT scan of each patient. Each lesion on the 3D and each of the five phases of the 4D scan were analyzed using a region of interest (ROI). For each patient the ROIs of the pre-RT scans were used to locate the areas of initial FDG uptake on the post-RT scans following rigid registration. Post-RT ROIs were drawn and the FDG uptake was compared with that of the pre-RT scans. Results: Sixteen distinct lesions from 12 patients were identified and analyzed. Standardized uptake value (SUV) maxima were significantly higher (p-value <0.005) for the lesions as measured on the 4D compared to 3D PET. Comparison of serial pre and post-RT scans showed a mean 62% decrease in SUV with the 3D PET scan (range 36–89%), and a 67% decrease with the 4D PET scan (range 30–89%). The mean absolute difference in SUV change on 3D versus 4D scans was 4.9%, with a range 0–15% (p-value = 0.07). Conclusions: Signal recovery with 4D PET results in higher SUVs when compared to standard 3D PET. Consequently, differences in the evaluation of SUV changes between pre and post-RT plans were observed. Such difference can have a significant impact in PET-based response assessment.

  15. Seasonal Changes in the Character and Nitrogen Content of Dissolved Organic Matter in an Alpine/Subalpine Headwater Catchment

    Directory of Open Access Journals (Sweden)

    Eran W. Hood

    2001-01-01

    Full Text Available We are studying the chemical quality of dissolved organic nitrogen (DON in a high-elevation watershed in the Colorado Front Range. Samples were collected over the 2000 snowmelt runoff season at two sites across an alpine/subalpine ecotone to understand how the transition between the lightly vegetated alpine and forested reaches of the catchment influences the chemical character of DON. Samples were analyzed approximately weekly for dissolved organic material (DOM content and chemical character. A subset of samples was analyzed for the elemental content of fulvic and hydrophilic acids. Concentrations of DON at both sites were highest in the spring at the initiation of snowmelt, decreased during snowmelt, and increased again during the late summer and fall. In contrast, concentrations of dissolved organic carbon (DOC peaked on the ascending limb of the hydrograph and declined to seasonal minima on the descending limb of the hydrograph. The ratio of DOC:DON showed a seasonal shift at both sites with high values (40 to 55 during peak runoff in early summer and lower values (15 to 25 during low flows late in the runoff season. These results indicate that there was a seasonal change in the relative N content of DOM at both sites. Chemical fractionation of DOC showed that there were temporal and longitudinal changes in the chemical character of DOC. At the alpine site, the fulvic acid content of DOC decreased from 57% in June to 35% in September. The change in fulvic acid was less pronounced at the forested site, from 66% in June to 54% in September. Elemental analysis of fulvic and hydrophilic acids indicated that hydrophilic acids were N rich compared to fulvic acids. Additionally, fulvic and hydrophilic acids isolated at the alpine site had a lower C:N ratio than those isolated at the forested site. Similarly, the C:N ratio of organic acids at both sites was lower in September than in June during peak runoff. These differences appear to be a result

  16. Fate of Fertilizer-Derived N Applied to Enhance Rice Straw Decomposition in a Paddy Field during the Fallow Season under Cool Temperature Conditions

    Directory of Open Access Journals (Sweden)

    Fumiaki Takakai

    2018-03-01

    Full Text Available A field experiment was conducted to evaluate the fate of nitrogen (N derived from fertilizer (fertilizer-derived N applied to a paddy field after rice harvesting to promote rice straw decomposition during the fallow season, and to determine its effect on soil N fertility in northern Japan. A frame containing soil mixed with rice straw and 15N-labeled fertilizer (4.3 g N m−2 ammonium sulfate [AS] or lime-nitrogen [LN] was placed into a paddy field on a gray lowland soil during the fallow season (October–April, and the following rice-growing season (May–September. Before cultivation (April, the percentages of fertilizer-derived N in soil + straw were higher for LN (55–72% than for AS (41–63%. At the harvesting stage (September, the percentages of fertilizer-derived N in plants were significantly higher for LN (4.9–6.2% than for AS (3.4–5.3%, and the percentages in soil were also significantly higher for LN (42–61% than for AS (31–38%. This could be attributed to the nitrification inhibitory effect of LN and result in the suppression of N losses via leaching. Consequently, fertilizer-derived N could contribute to the maintenance of soil N fertility, and this effect could be higher for LN than AS.

  17. Simulation of water management for fodder beet to reduce yield losses under late season drought

    Directory of Open Access Journals (Sweden)

    T. Noreldin

    2016-12-01

    Full Text Available The objectives of this study were to calibrate CropSyst model for fodder beet grown under full and late season drought and to use the simulation results to analyze the relationship between irrigation amount and yield, as well as in water management to reduce yield losses under full and late season drought. For this reason, two field experiments were implemented at El-Serw Agricultural Research Station in Demiatte governorate, during 2011/12 and 2012/13 growing seasons. Two irrigation treatments were studied: full irrigation and late season drought. The model was calibrated using the data obtained from the two seasons. Results indicated that the reduction in fodder beet yield under late season drought was 11 and 12% in 2011/12 and 2012/13 growing seasons, respectively. Calibration of CropSyst revealed that the percentage of difference between measured and predicted values were low in both growing seasons. The results also indicated that changing irrigation schedule after examining water stress index under full and late season drought led to increase in fodder beet yield, as well as water and land productivity. Thus, CropSyst model can give insight into when to apply irrigation water to minimize yield losses under late season drought.

  18. Limnological characteristics and seasonal changes in density and diversity of the phytoplanktonic community at the Caçó pond, Maranhão State, Brazil

    Directory of Open Access Journals (Sweden)

    Maria José Dellamano-Oliveira

    2003-12-01

    Full Text Available Seasonal changes of the phytoplanktonic community and limnological abiotic characteristics of Caçó pond (Maranhão State, Brazil was evaluated from two field researches during the rainy (April 1999 and dry (November 1999 seasons. Measurements of twelve chemical and physical variables and phytoplankton collections were carried out at eight sampling stations. The Chlorophyceae and Cyanobacteria groups were in highest fractions during the rainy and dry seasons, respectively. The limnological abiotic variables showed a homogenous spatial distribution. The cluster analysis, using Bray-Curtis distance, distinguished two major groups, represented by the most common and abundant species in both the periods. The results showed that the climate regime, due to the seasonal changes in pluviosity, was a determinant over the phytoplanktonic community structure at Caçó pond.Mudanças sazonais na comunidade fitoplanctônica e nas características limnológicas abióticas da lagoa do Caçó, Estado do Maranhão, Brasil, foram avaliadas a partir de duas coletas, nos períodos de chuva (Abril/1999 e seca (Novembro/1999. Medidas de quatorze variáveis físicas e químicas e coletas do fitoplâncton foram realizadas em oito estações de amostragem. Quantitativamente, os grupos Chlorophyceae e Cyanobacteria apresentaram maior contribuição nos períodos de chuva e seca, respectivamente. As variáveis limnológicas abióticas mostraram uma distribuição espacial homogênea em relação aos dois períodos amostrados. A análise de agrupamento a partir da distância de Bray-Curtis para comunidade fitoplanctônica distinguiu dois grandes grupos (estação seca e chuvosa, representados pelas espécies mais comuns e abundantes em ambos períodos. Os resultados deste estudo permitiram concluir que o regime climatológico foi determinante sobre a dinâmica e a estrutura da comunidade fitoplanctônica da lagoa do Caçó.

  19. Communicative action: the Habermasian and Freirean dialogical approach to participatory communication for social change in a post-1994 South Africa

    Directory of Open Access Journals (Sweden)

    H. Otto

    2009-07-01

    Full Text Available Despite its almost four decade mainstay, the field of parti-cipatory communication for social change still experiences a definitional and pragmatic problem regarding what exactly participation is (cf. Jacobson & Storey, 2004; Chambers, 1994; Melkote & Steeves, 2001; Rogers, 1976; Lerner, 1964; Schramm, 1964; Servaes, 1995. What remains is a vastly under-theorised field of participatory communication for social change. This article examines the possibility of participatory communication approaching the Habermasian “ideal speech situation” in which people, as communicators, are seen as having a value in their own right and not simply regarded as a means to an end (cf. Habermas, 1984; 1987; 1989. Consistent with the Freirean “liberal pedagogy”, the praxis of dialogical communication or intersubjective communication is seen as putting right the “participative” quality of participatory com-munication (cf. Freire, 1970. For both theorists, transformative action can only occur if reflective and collective learning occurs in linguistically constructed settings where the normative dimensions of truth (logos, rightfulness (ethos and truthfulness (pathos are raised and met in the developmental conversation. This is especially significant in a globalised world and fragmented, post-bourgeois public sphere where debate among developmental stakeholders is becoming more marginal, in-strumentalist, and less public. Based on available analyses of development communication literature, this article proposes that the chosen dialogical approaches share a type of communi-cative behaviour (i.e. action theoretic, rather than representing a particular paradigm or school of thought. This could offer further definitional clarification of proper participatory communi-cation for social change in a post-1994 South Africa.

  20. Seasonality of cavitation and frost fatigue in Acer mono Maxim.

    Science.gov (United States)

    Zhang, Wen; Feng, Feng; Tyree, Melvin T

    2017-12-08

    Although cavitation is common in plants, it is unknown whether the cavitation resistance of xylem is seasonally constant or variable. We tested the changes in cavitation resistance of Acer mono before and after a controlled cavitation-refilling and freeze-thaw cycles for a whole year. Cavitation resistance was determined from 'vulnerability curves' showing the percent loss of conductivity versus xylem tension. Cavitation fatigue was defined as a reduction of cavitation resistance following a cavitation-refilling cycle, whereas frost fatigue was caused by a freeze-thaw cycle. A. mono developed seasonal changes in native embolisms; values were relatively high during winter but relatively low and constant throughout the growing season. Cavitation fatigue occurred and changed seasonally during the 12-month cycle; the greatest fatigue response occurred during summer and the weakest during winter, and the transitions occurred during spring and autumn. A. mono was highly resistant to frost damage during the relatively mild winter months; however, a quite different situation occurred during the growing season, as the seasonal trend of frost fatigue was strikingly similar to that of cavitation fatigue. Seasonality changes in cavitation resistance may be caused by seasonal changes in the mechanical properties of the pit membranes. © 2017 John Wiley & Sons Ltd.

  1. Hormonal changes during the mating and conception seasons of wild northern muriquis (Brachyteles arachnoides hypoxanthus).

    Science.gov (United States)

    Strier, Karen B; Lynch, Jessica W; Ziegler, Toni E

    2003-10-01

    We investigated hormonal and behavioral changes in wild male and female northern muriquis (Brachyteles arachnoides hypoxanthus) at the Estação Biológica de Caratinga, Minas Gerais, Brazil, during a 6-mo period that encompassed the onset of the 1998-1999 mating and conception seasons. Individual females resumed mating with the resumption of ovarian cycling, which was not synchronized among them or related to their cortisol levels. Females experienced two to seven cycles prior to conceiving, and the first conception occurred 2 mo after the onset of the group's mating season. There were no differences in female cortisol levels across their premating, mating, and conception conditions. Cortisol levels were significantly higher in females than in males prior to the conception season, consistent with the prediction that energy reserves may be associated with breeding readiness in females, but not males, in this species. The sustained elevation in male cortisol occurred after the peak in their sexual activity, which resulted in the first conception of the year. Male cortisol levels were positively correlated between years that were similar in rainfall, but differed in the timing of sexual and reproductive events. The timing of cortisol elevations in males appears to be generally regulated by environmental cues, but is responsive to fine-tuning by social and behavioral cues related to the unpredictable timing of reproductive opportunities within their extended mating season. Copyright 2003 Wiley-Liss, Inc.

  2. Seasonal changes of the pelagic fish assemblage in a temperate estuary

    Science.gov (United States)

    Hagan, S. M.; Able, K. W.

    2003-01-01

    The pelagic (i.e. fishes that spend most of their time swimming and feeding in the water column) fish assemblage was examined within a temperate estuary to determine the seasonal patterns of abundance, biomass, richness, and species composition. These measures were related to abiotic measures including temperature, salinity, water transparency, and depth. Pelagic fish (nGasterosteus aculeatus and age 1+ by M. menidia. Spring (April-early June) was overwhelmingly dominated by age 0+ C. harengus. Early summer (late June-early July) was relatively species rich and characterized by age 0+ of Brevoortia tyrannus, Pomatomus saltatrix, Alosa pseudoharengus, and age 1+ of A. mitchilli. Late summer (late July-August) remained relatively species rich and included mostly age 0+ of A. mitchilli, A. hepsetus, and M. menidia. Autumn (September-November) continued to have high catches of age 0+ of M. menidia and A. mitchilli. As expected for temperate estuaries, the best of the measured abiotic predictors of these groupings included temperature, salinity, and degree of change in temperature. However, timing of life history characteristics, such as location, and timing of reproduction and migration also influenced the seasonal occurrence of these pelagic species. The large abundance and biomass of a relatively few species, as observed in this study, are typical of estuaries, although this is one of the few studies that have focused solely on the pelagic component of estuarine fish assemblages.

  3. Overexpression of suppressor of cytokine signaling 3 in the arcuate nucleus of juvenile Phodopus sungorus alters seasonal body weight changes.

    Science.gov (United States)

    Ganjam, Goutham K; Benzler, Jonas; Pinkenburg, Olaf; Boucsein, Alisa; Stöhr, Sigrid; Steger, Juliane; Culmsee, Carsten; Barrett, Perry; Tups, Alexander

    2013-12-01

    The profound seasonal cycle in body weight exhibited by the Djungarian hamster (Phodopus sungorus) is associated with the development of hypothalamic leptin resistance during long day photoperiod (LD, 16:8 h light dark cycle), when body weight is elevated relative to short day photoperiod (SD, 8:16 h light dark cycle). We previously have shown that this seasonal change in physiology is associated with higher levels of mRNA for the potent inhibitor of leptin signaling, suppressor of cytokine signaling-3 (SOCS3), in the arcuate nucleus (ARC) of LD hamsters relative to hamsters in SD. The alteration in SOCS3 gene expression preceded the body weight change suggesting that SOCS3 might be the molecular switch of seasonal body weight changes. To functionally characterize the role of SOCS3 in seasonal body weight regulation, we injected SOCS3 expressing recombinant adeno-associated virus type-2 (rAAV2-SOCS3) constructs into the ARC of leptin sensitive SD hamsters immediately after weaning. Hamsters that received rAAV2 expressing enhanced green fluorescent protein (rAAV2-EGFP) served as controls. ARC-directed SOCS3 overexpression led to a significant increase in body weight over a period of 12 weeks without fully restoring the LD phenotype. This increase was partially due to elevated brown and white adipose tissue mass. Gene expression of pro-opiomelanocortin was increased while thyroid hormone converting enzyme DIO3 mRNA levels were reduced in SD hamsters with SOCS3 overexpression. In conclusion, our data suggest that ARC-directed SOCS3 overexpression partially overcomes the profound seasonal body weight cycle exhibited by the hamster which is associated with altered pro-opiomelanocortin and DIO3 gene expression.

  4. Leptin and ghrelin in anadromous Arctic charr: cloning and change in expressions during a seasonal feeding cycle.

    Science.gov (United States)

    Frøiland, Eirik; Murashita, Koji; Jørgensen, Even Hjalmar; Kurokawa, Tadahide

    2010-01-01

    Anadromous (sea-migrating) Arctic charr (Salvelinus alpinus) display pronounced seasonal variations in food intake and growth and is an interesting model for studying mechanisms of appetite regulation. In this study cDNAs encoding for ghrelin (GHRL) and leptin (LEP) in Arctic charr were cloned, after which stomach GHRL and liver LEP mRNA expressions were examined by qPCR during a seasonal feeding cycle of semi-wild anadromous Arctic charr. The fish were captured as they returned from summer feeding in seawater and transferred to an indoor tank where they were fed in excess until October the year after. Growth rate was low in late winter, increased in late spring and reached a peak during summer, and then declined during autumn, when the fish became sexually mature. The changes in growth rate were associated with corresponding changes in the proportion of fish that had been eating at each sampling date, and whole body lipid status. Stomach GHRL mRNA expression was high in late winter, decreased to a nadir in mid-summer and increased again to a high level in early autumn. Liver LEP mRNA remained low during winter, spring and early summer, after which there was a gradual, 7-fold increase until October. The seasonal changes in ghrelin and leptin support a role of these hormones in the long-term regulation of energy homeostasis in the anadromous Arctic charr. It cannot be excluded, however, that the increase in liver leptin expression during autumn is related to sexual maturation.

  5. GLM Post Launch Testing and Airborne Science Field Campaign

    Science.gov (United States)

    Goodman, S. J.; Padula, F.; Koshak, W. J.; Blakeslee, R. J.

    2017-12-01

    The Geostationary Operational Environmental Satellite (GOES-R) series provides the continuity for the existing GOES system currently operating over the Western Hemisphere. The Geostationary Lightning Mapper (GLM) is a wholly new instrument that provides a capability for total lightning detection (cloud and cloud-to-ground flashes). The first satellite in the GOES-R series, now GOES-16, was launched in November 2016 followed by in-orbit post launch testing for approximately 12 months before being placed into operations replacing the GOES-E satellite in December. The GLM will map total lightning continuously throughout day and night with near-uniform spatial resolution of 8 km with a product latency of less than 20 sec over the Americas and adjacent oceanic regions. The total lightning is very useful for identifying hazardous and severe thunderstorms, monitoring storm intensification and tracking evolution. Used in tandem with radar, satellite imagery, and surface observations, total lightning data has great potential to increase lead time for severe storm warnings, improve aviation safety and efficiency, and increase public safety. In this paper we present initial results from the post-launch in-orbit performance testing, airborne science field campaign conducted March-May, 2017 and assessments of the GLM instrument and science products.

  6. Post-modern changes in marital and family life

    Directory of Open Access Journals (Sweden)

    Agata Kozak

    2011-06-01

    Full Text Available Contemporarily, the traditional model of marriage is no longer the only accepted form of family life; there are many alternatives to that type of relationship. In post-modernity we face a rapid change in the perception of informal relationships as well as their dynamic development and increase in number. However, will cohabitation - which in the times of moral relativism, praise of freedom and individuality and democratisation of all aspects of human life becomes increasingly popular – eventually dominate and replace traditional marriage?

  7. Principles of Leading Change: An Inductive Analysis from Post-Katrina New Orleans

    Science.gov (United States)

    Beabout, Brian R.

    2014-01-01

    Despite over forty years of research on theories of educational change, little is known of the change theories-in-use of school-based administrators, often tasked with implementing externally imposed reform mandates. Capitalizing on the unique case of post-Katrina schooling, this qualitative study examines the ways in which ten principals spoke…

  8. Do Changes in Muscle Architecture Affect Post-Activation Potentiation?

    Directory of Open Access Journals (Sweden)

    Danielle Reardon, Jay R. Hoffman, Gerald T. Mangine, Adam J. Wells, Adam M. Gonzalez, Adam R. Jajtner, Jeremy R. Townsend, William P. McCormack, Jeffrey R. Stout, Maren S. Fragala, David H. Fukuda

    2014-09-01

    Full Text Available The purpose of this randomized, cross-over design study was to examine the effect of three different muscle potentiation protocols on acute changes in muscle architecture and vertical jump performance. Eleven experienced, resistance trained men (25.2±3.6y completed three potentiation squat protocols using moderate intensity (MI; 75%, 3 sets x 10 repetitions, high intensity (HI; 90%, 3 sets x 3 repetitions and 100% (1RM; 1 set x 1repetition of their 1RM. In addition, all participants completed a control session (CTL in which no protocol was performed. During each testing session, muscle architecture and vertical jump testing were assessed at baseline (BL, 8min post (8P and 20min post (20P workout. Ultrasound measures included cross sectional area (CSA and pennation angle (PANG of both the rectus femoris (RF and vastus lateralis (VL. Following each ultrasound measure, peak vertical jump power (PVJP and mean (MVJP power was assessed using an accelerometer. Magnitude based inferences were used to make comparisons between trials. The MI trial resulted in a likely greater increase from BL to 8P and 20P in RF-CSA and VL-CSA, while the HI trial resulted in a likely greater change from BL to 20P in both RF-CSA and VL-CSA. Meanwhile, changes in PVJP and MVJP for the MI trial was likely decreased at BL-8P and BL–20P, while the HI trial was shown to result in a likely or possible decrease compared to CTL at BL-8P and BL–20P, respectively. A likely negative relationship was observed between changes in VL-PANG and MVJP (r = -0.35; p , 0.018 at BL-8P, and between changes in PVJP and RF-CSA (r = -0.37; p , 0.014 at BL–20P. Results of this study were unable to demonstrate any potentiation response from the trials employed, however these protocols did result in acute muscle architectural changes.

  9. Relationships between aquatic vegetation and water turbidity: A field survey across seasons and spatial scales.

    Science.gov (United States)

    Austin, Åsa N; Hansen, Joakim P; Donadi, Serena; Eklöf, Johan S

    2017-01-01

    Field surveys often show that high water turbidity limits cover of aquatic vegetation, while many small-scale experiments show that vegetation can reduce turbidity by decreasing water flow, stabilizing sediments, and competing with phytoplankton for nutrients. Here we bridged these two views by exploring the direction and strength of causal relationships between aquatic vegetation and turbidity across seasons (spring and late summer) and spatial scales (local and regional), using causal modeling based on data from a field survey along the central Swedish Baltic Sea coast. The two best-fitting regional-scale models both suggested that in spring, high cover of vegetation reduces water turbidity. In summer, the relationships differed between the two models; in the first model high vegetation cover reduced turbidity; while in the second model reduction of summer turbidity by high vegetation cover in spring had a positive effect on summer vegetation which suggests a positive feedback of vegetation on itself. Nitrogen load had a positive effect on turbidity in both seasons, which was comparable in strength to the effect of vegetation on turbidity. To assess whether the effect of vegetation was primarily caused by sediment stabilization or a reduction of phytoplankton, we also tested models where turbidity was replaced by phytoplankton fluorescence or sediment-driven turbidity. The best-fitting regional-scale models suggested that high sediment-driven turbidity in spring reduces vegetation cover in summer, which in turn has a negative effect on sediment-driven turbidity in summer, indicating a potential positive feedback of sediment-driven turbidity on itself. Using data at the local scale, few relationships were significant, likely due to the influence of unmeasured variables and/or spatial heterogeneity. In summary, causal modeling based on data from a large-scale field survey suggested that aquatic vegetation can reduce turbidity at regional scales, and that high

  10. Relationships between aquatic vegetation and water turbidity: A field survey across seasons and spatial scales.

    Directory of Open Access Journals (Sweden)

    Åsa N Austin

    Full Text Available Field surveys often show that high water turbidity limits cover of aquatic vegetation, while many small-scale experiments show that vegetation can reduce turbidity by decreasing water flow, stabilizing sediments, and competing with phytoplankton for nutrients. Here we bridged these two views by exploring the direction and strength of causal relationships between aquatic vegetation and turbidity across seasons (spring and late summer and spatial scales (local and regional, using causal modeling based on data from a field survey along the central Swedish Baltic Sea coast. The two best-fitting regional-scale models both suggested that in spring, high cover of vegetation reduces water turbidity. In summer, the relationships differed between the two models; in the first model high vegetation cover reduced turbidity; while in the second model reduction of summer turbidity by high vegetation cover in spring had a positive effect on summer vegetation which suggests a positive feedback of vegetation on itself. Nitrogen load had a positive effect on turbidity in both seasons, which was comparable in strength to the effect of vegetation on turbidity. To assess whether the effect of vegetation was primarily caused by sediment stabilization or a reduction of phytoplankton, we also tested models where turbidity was replaced by phytoplankton fluorescence or sediment-driven turbidity. The best-fitting regional-scale models suggested that high sediment-driven turbidity in spring reduces vegetation cover in summer, which in turn has a negative effect on sediment-driven turbidity in summer, indicating a potential positive feedback of sediment-driven turbidity on itself. Using data at the local scale, few relationships were significant, likely due to the influence of unmeasured variables and/or spatial heterogeneity. In summary, causal modeling based on data from a large-scale field survey suggested that aquatic vegetation can reduce turbidity at regional scales

  11. Variations of streambed vertical hydraulic conductivity before and after a flood season

    Science.gov (United States)

    Wu, Guangdong; Shu, Longcang; Lu, Chengpeng; Chen, Xunhong; Zhang, Xiao; Appiah-Adjei, Emmanuel K.; Zhu, Jingsi

    2015-11-01

    The change of vertical hydraulic conductivity ( K v) before and after a flood season is crucial in understanding the long-term temporal variation of streambed permeability. Therefore, in this study, a detailed K v field investigation was conducted at an in-channel site within the Dawen River, China, before and after a flood season. In-situ falling-head permeameter tests were performed for the determination of K v. The tests were conducted using a 10 × 10 grid, at five different depths. In total, 871 valid K v values from layers 1-5 were obtained. The Kruskal-Wallis test on these K v values before and after the flood season shows they belonged to different populations. The sediments before the flood season primarily consisted of sand and gravel, whereas after the flood season, patchy distribution of silt/clay occurred in the sandy streambed and silt/clay content increased with the increasing depth; under the losing condition during flooding, downward movement of water brought fine particles into the coarse sediments, partially silting the pores. Accordingly, the K v values after the flood season had a smaller mean and median, and a higher level of heterogeneity, compared to those before the flood season. Additionally, the distribution pattern in K v across the stream differed before and after flood season; after the flood season, there was an increasing trend in K v from the south bank to the north bank. Overall, the contrasts of K v before and after the flood season were predominantly subject to the infiltration of fine particles.

  12. Southern African Regional Science Initiative (SAFARI 2000): wet season campaigns

    CSIR Research Space (South Africa)

    Otter, LB

    2002-03-01

    Full Text Available The Southern African Regional Science Initiative (SAFARI 2000) involved two wet season and one dry season field campaigns. This paper reports on the wet season campaigns. The first was conducted at five sites along the Kalahari Transect in Zambia...

  13. Trend analysis and change point detection of annual and seasonal temperature series in Peninsular Malaysia

    Science.gov (United States)

    Suhaila, Jamaludin; Yusop, Zulkifli

    2017-06-01

    Most of the trend analysis that has been conducted has not considered the existence of a change point in the time series analysis. If these occurred, then the trend analysis will not be able to detect an obvious increasing or decreasing trend over certain parts of the time series. Furthermore, the lack of discussion on the possible factors that influenced either the decreasing or the increasing trend in the series needs to be addressed in any trend analysis. Hence, this study proposes to investigate the trends, and change point detection of mean, maximum and minimum temperature series, both annually and seasonally in Peninsular Malaysia and determine the possible factors that could contribute to the significance trends. In this study, Pettitt and sequential Mann-Kendall (SQ-MK) tests were used to examine the occurrence of any abrupt climate changes in the independent series. The analyses of the abrupt changes in temperature series suggested that most of the change points in Peninsular Malaysia were detected during the years 1996, 1997 and 1998. These detection points captured by Pettitt and SQ-MK tests are possibly related to climatic factors, such as El Niño and La Niña events. The findings also showed that the majority of the significant change points that exist in the series are related to the significant trend of the stations. Significant increasing trends of annual and seasonal mean, maximum and minimum temperatures in Peninsular Malaysia were found with a range of 2-5 °C/100 years during the last 32 years. It was observed that the magnitudes of the increasing trend in minimum temperatures were larger than the maximum temperatures for most of the studied stations, particularly at the urban stations. These increases are suspected to be linked with the effect of urban heat island other than El Niño event.

  14. Seasonal Changes in Mycosporine-Like Amino Acid Production Rate with Respect to Natural Phytoplankton Species Composition

    Directory of Open Access Journals (Sweden)

    Sun-Yong Ha

    2015-11-01

    Full Text Available After in situ incubation at the site for a year, phytoplanktons in surface water were exposed to natural light in temperate lakes (every month; thereafter, the net production rate of photoprotective compounds (mycosporine-like amino acids, MAAs was calculated using 13C labeled tracer. This is the first report describing seasonal variation in the net production rate of individual MAAs in temperate lakes using a compound-specific stable isotope method. In the mid-latitude region of the Korean Peninsula, UV radiation (UVR usually peaks from July to August. In Lake Paldang and Lake Cheongpyeong, diatoms dominated among the phytoplankton throughout the year. The relative abundance of Cyanophyceae (Anabaena spiroides reached over 80% during July in Lake Cheongpyeong. Changes in phytoplankton abundance indicate that the phytoplankton community structure is influenced by seasonal changes in the net production rate and concentration of MAAs. Notably, particulate organic matter (POM showed a remarkable change based on the UV intensity occurring during that period; this was because of the fact that cyanobacteria that are highly sensitive to UV irradiance dominated the community. POM cultured in Lake Paldang had the greatest shinorine (SH production rate during October, i.e., 83.83 ± 10.47 fgC·L−1·h−1. The dominance of diatoms indicated that they had a long-term response to UVR. Evaluation of POM cultured in Lake Cheongpyeong revealed that there was an increase in the net MAA production in July (when UVR reached the maximum; a substantial amount of SH, i.e., 17.62 ± 18.34 fgC·L−1·h−1, was recorded during this period. Our results demonstrate that both the net production rate as well as the concentration of MAAs related to photoinduction depended on the phytoplankton community structure. In addition, seasonal changes in UVR also influenced the quantity and production of MAAs in phytoplanktons (especially Cyanophyceae.

  15. Direct observation and mechanism for enhanced field emission sites in platinum ion implanted/post-annealed ultrananocrystalline diamond films

    Energy Technology Data Exchange (ETDEWEB)

    Panda, Kalpataru, E-mail: panda@afm.eei.eng.osaka-u.ac.jp, E-mail: phy.kalpa@gmail.com; Inami, Eiichi; Sugimoto, Yoshiaki [Graduate School of Engineering, Osaka University, 2-1, Yamada-Oka, Suita, Osaka 565-0871 (Japan); Sankaran, Kamatchi J.; Tai, Nyan Hwa [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lin, I-Nan, E-mail: inanlin@mail.tku.edu.tw [Department of Physics, Tamkang University, Tamsui 251, Taiwan (China)

    2014-10-20

    Enhanced electron field emission (EFE) properties for ultrananocrystalline diamond (UNCD) films upon platinum (Pt) ion implantation and subsequent post-annealing processes is reported, viz., low turn-on field of 4.17 V/μm with high EFE current density of 5.08 mA/cm{sup 2} at an applied field of 7.0 V/μm. Current imaging tunneling spectroscopy (CITS) mode in scanning tunneling spectroscopy directly revealed the increased electron emission sites density for Pt ion implanted/post-annealed UNCD films than the pristine one. The high resolution CITS mapping and local current–voltage characteristic curves demonstrated that the electrons are dominantly emitted from the diamond grain boundaries and Pt nanoparticles.

  16. Direct observation and mechanism for enhanced field emission sites in platinum ion implanted/post-annealed ultrananocrystalline diamond films

    International Nuclear Information System (INIS)

    Panda, Kalpataru; Inami, Eiichi; Sugimoto, Yoshiaki; Sankaran, Kamatchi J.; Tai, Nyan Hwa; Lin, I-Nan

    2014-01-01

    Enhanced electron field emission (EFE) properties for ultrananocrystalline diamond (UNCD) films upon platinum (Pt) ion implantation and subsequent post-annealing processes is reported, viz., low turn-on field of 4.17 V/μm with high EFE current density of 5.08 mA/cm 2 at an applied field of 7.0 V/μm. Current imaging tunneling spectroscopy (CITS) mode in scanning tunneling spectroscopy directly revealed the increased electron emission sites density for Pt ion implanted/post-annealed UNCD films than the pristine one. The high resolution CITS mapping and local current–voltage characteristic curves demonstrated that the electrons are dominantly emitted from the diamond grain boundaries and Pt nanoparticles.

  17. Post-silking Factor Consequences for N Efficiency Changes Over 38 Years of Commercial Maize Hybrids

    Directory of Open Access Journals (Sweden)

    Keru Chen

    2017-10-01

    Full Text Available Hybrid selection in maize (Zea mays L. over the decades has increased post-silking dry matter (PostDM and nitrogen (PostN accumulation, often with an accompanying increase in one or more N use efficiency (NUE metrics such as partial factor productivity (PFP, N conversion efficiency (NCE, and N internal efficiency (NIE. More certainty on the underlying mechanisms of how PostDM and PostN changes over time have contributed to NUE gains or losses in modern-era hybrids can only be realized by directly comparing hybrids of different eras in the context of production-system-relevant management systems. A two-year and two-location field study was conducted in Indiana with two N rates (55 and 220 kg N ha−1, three plant densities (54,000, 79,000, and 104,000 plants ha−1 and eight commercial hybrids that were released by a single seed company from 1967 to 2005. The main treatment effects of N rate, density, and hybrid dominated the PostDM and PostN responses, and there were no significant two-way or three-way interactions. Total dry matter at maturity gains averaged 80 kg ha−1 year−1 of hybrid release when averaged over locations, plant densities and N rates. Total N contents at maturity increased 0.68 kg ha−1 year−1, primarily due to annual increases in grain N content (0.8 kg ha−1 year−1. Post-silking N uptake rate increased 0.44 kg ha−1 year−1 for these era hybrids in more favorable production site-years. Slopes of grain N concentration increases per unit PostN gain were similar for all hybrids. Gains in average PFP over time were considerably higher at the low N rate (0.9 kg ha−1 year−1 than at the high N rate (0.3 kg kg−1 year−1. Hybrid gains in NIE were evident from 1967 to 1994, but not thereafter. The low N rate and higher plant densities also increased relative NIE and NCE values, but without hybrid interactions. There was no consistent trend of NIE or NCE gains in these hybrids primarily because grain and whole-plant N

  18. Effects of the Competitive Season on the Isokinetic Muscle Parameters Changes in World-Class Handball Players.

    Science.gov (United States)

    Maurelli, Olivier; Bernard, Pierre L; Dubois, Romain; Ahmaidi, Said; Prioux, Jacques

    2018-05-25

    Maurelli, O, Bernard, PL, Dubois, R, Ahmaidi, S, and Prioux, J. Effects of the competitive season on the isokinetic muscle parameters changes in world-class handball players. J Strength Cond Res XX(X): 000-000, 2018-The aim of this study is to investigate the effects of the competitive season on isokinetic muscular parameters of the lower limbs in world-class handball players. Nineteen, male, world-class, handball players (age, 26.6 ± 5.4 years) participated in the study. Two bilateral isokinetic tests of knee joint flexors (H; hamstring) and extensors (Q; quadriceps) were performed in the beginning and end of the competitive season to determine the peak torque (PT), the mean power, and agonist-antagonist ratio, dominant-nondominant ratio (DNDR), and combined ratio. The results showed a significant decrease in PT values at low angular velocity (60°·s) in concentric mode for Q on dominant leg (p handball players. Accordingly, this study should help trainers to modify their planning to maximize strength and power qualities of the lower limbs of their players in addition to avoiding injuries.

  19. Considerable Enhancement of Field Emission of SnO2Nanowires by Post-Annealing Process in Oxygen at High Temperature

    Directory of Open Access Journals (Sweden)

    Fang XS

    2009-01-01

    Full Text Available Abstract The field emission properties of SnO2nanowires fabricated by chemical vapor deposition with metallic catalyst-assistance were investigated. For the as-fabricated SnO2nanowires, the turn-on and threshold field were 4.03 and 5.4 V/μm, respectively. Considerable enhancement of field emission of SnO2nanowires was obtained by a post-annealing process in oxygen at high temperature. When the SnO2nanowires were post-annealed at 1,000 °C in oxygen, the turn-on and threshold field were decreased to 3.77 and 4.4 V/μm, respectively, and the current density was increased to 6.58 from 0.3 mA/cm2at the same applied electric field of 5.0 V/μm.

  20. Impact of season and location on the natural radioactivity in marine macroalgae (Gracilaria edulis) of coastal Tamil Nadu, India

    International Nuclear Information System (INIS)

    Saroja, P.M.; Raj, G.A.G.; Selvan, K.E.

    2012-01-01

    Gracilaria edulis, an edible red marine macro algae from three high background radiation areas (Arockiapuram, Kadiapattinam and Kurumpanai) on the southwest coast of Tamil Nadu, and one low background radiation area (Mandapam) on the southeast coast of Tamil Nadu, in India, were studied for variations in average gross alpha and beta radiation activities. Significant variations in average gross beta activities were observed while alpha activities showed only marginal variation. The average gross alpha activity was recorded high (61.51 Bq kg -1 ) during the post southwest monsoon season, while it recorded lowest (25.48 Bq kg -1 ) during the post northeast monsoon season. Average gross beta activity varied between seasons with the lowest level (211.55 Bq Kg -1 ) during post southwest monsoon season and the highest (413.33 Bq kg -1 ) during post northeast monsoon season. Among the four locations, the gross alpha activity was high (70.95 ± 26.74 Bq Kg -1 ) in Arockiapuram and low (18.74 ± 6.32 Bq Kg -1 ) in Mandapam, while the gross beta activity was high (442.25 ± 168.53 Bq Kg -1 ) in Kurumpanai and low (158.63 ± 34.37 Bq Kg -1 ) in Mandapam. Average gross alpha activity in G. edulis was found significantly varying in terms of locations, while average gross beta activity for the same species recorded significant seasonal variation. (author)

  1. Monitoring the Effects of Forest Restoration Treatments on Post-Fire Vegetation Recovery with MODIS Multitemporal Data

    Directory of Open Access Journals (Sweden)

    Willem J. D. van Leeuwen

    2008-03-01

    Full Text Available This study examines how satellite based time-series vegetation greenness data and phenological measurements can be used to monitor and quantify vegetation recovery after wildfire disturbances and examine how pre-fire fuel reduction restoration treatments impact fire severity and impact vegetation recovery trajectories. Pairs of wildfire affected sites and a nearby unburned reference site were chosen to measure the post-disturbance recovery in relation to climate variation. All site pairs were chosen in forested uplands in Arizona and were restricted to the area of the Rodeo-Chediski fire that occurred in 2002. Fuel reduction treatments were performed in 1999 and 2001. The inter-annual and seasonal vegetation dynamics before, during, and after wildfire events can be monitored using a time series of biweekly composited MODIS NDVI (Moderate Resolution Imaging Spectroradiometer - Normalized Difference Vegetation Index data. Time series analysis methods included difference metrics, smoothing filters, and fitting functions that were applied to extract seasonal and inter-annual change and phenological metrics from the NDVI time series data from 2000 to 2007. Pre- and post-fire Landsat data were used to compute the Normalized Burn Ratio (NBR and examine burn severity at the selected sites. The phenological metrics (pheno-metrics included the timing and greenness (i.e. NDVI for the start, peak and end of the growing season as well as proxy measures for the rate of green-up and senescence and the annual vegetation productivity. Pre-fire fuel reduction treatments resulted in lower fire severity, which reduced annual productivity much less than untreated areas within the Rodeo-Chediski fire perimeter. The seasonal metrics were shown to be useful for estimating the rate of post-fire disturbance recovery and the timing of phenological greenness phases. The use of satellite time series NDVI data and derived pheno-metrics show potential for tracking vegetation

  2. Long-term and seasonal Caspian Sea level change from satellite gravity and altimeter measurements

    Science.gov (United States)

    Chen, J. L.; Wilson, C. R.; Tapley, B. D.; Save, H.; Cretaux, Jean-Francois

    2017-03-01

    We examine recent Caspian Sea level change by using both satellite radar altimetry and satellite gravity data. The altimetry record for 2002-2015 shows a declining level at a rate that is approximately 20 times greater than the rate of global sea level rise. Seasonal fluctuations are also much larger than in the world oceans. With a clearly defined geographic region and dominant signal magnitude, variations in the sea level and associated mass changes provide an excellent way to compare various approaches for processing satellite gravity data. An altimeter time series derived from several successive satellite missions is compared with mass measurements inferred from Gravity Recovery and Climate Experiment (GRACE) data in the form of both spherical harmonic (SH) and mass concentration (mascon) solutions. After correcting for spatial leakage in GRACE SH estimates by constrained forward modeling and accounting for steric and terrestrial water processes, GRACE and altimeter observations are in complete agreement at seasonal and longer time scales, including linear trends. This demonstrates that removal of spatial leakage error in GRACE SH estimates is both possible and critical to improving their accuracy and spatial resolution. Excellent agreement between GRACE and altimeter estimates also provides confirmation of steric Caspian Sea level change estimates. GRACE mascon estimates (both the Jet Propulsion Laboratory (JPL) coastline resolution improvement version 2 solution and the Center for Space Research (CSR) regularized) are also affected by leakage error. After leakage corrections, both JPL and CSR mascon solutions also agree well with altimeter observations. However, accurate quantification of leakage bias in GRACE mascon solutions is a more challenging problem.

  3. Alteration of Water Pollution Level with the Seasonal Changes in Mean Daily Discharge in Three Main Rivers around Dhaka City, Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Saiful Islam

    2015-06-01

    Full Text Available A study based on the physicochemical parameters and dissolved metals levels from three main rivers around Dhaka City, Bangladesh, was conducted in order to determine the present pollution status and their alteration trends with the seasonal change of discharge amount. The water samples were collected from the rivers Buriganga, Turag, and Shitalakkhya during both dry and monsoon seasons. Physicochemical analyses revealed that most of the water quality parameters exceeded the recommended levels set by the Department of Environment (DoE, Bangladesh, during both the dry and monsoon seasons. A very strong positive correlation was found between biochemical oxygen demand (BOD and chemical oxygen demand (COD in all sampling points. Both BOD and COD values had a strong negative correlation with dissolved oxygen (DO in the Shitalakkhya River. Most of the dissolved metals concentrations in the water samples were similar. However, the concentrations of different physicochemical properties varied with the seasons. The dry season had significantly higher contamination loads, which were decreased during the monsoon season. Anthropogenic activities, as well as the variation in river water flow during different seasons were the main reasons for this high degree of water pollution.

  4. 76 FR 77856 - International Mail Price Change for Inbound Air Parcel Post

    Science.gov (United States)

    2011-12-14

    ... Commission is noticing a recently-filed Postal Service request to change rates for Inbound Air Parcel Post at....\\2\\ Notice at 2. \\1\\ Notice of the United States Postal Service of Filing Changes in Rates Not of..., 2011 (Notice). \\2\\ See Docket Nos. MC2010-11 and CP2010-11, Request of the United States Postal Service...

  5. Recovery Time After a Late-Dry Season Fire: the Effect on Fluxes, Surface Properties and Vegetation Green-Up.

    Science.gov (United States)

    Saha, M. V.; D'Odorico, P.; Scanlon, T. M.

    2014-12-01

    Large regions of Africa burn on an annual basis. These fires damage vegetation, change surface albedo and modify the hydrologic cycle. Quantifying the magnitude and persistence of these changes is key in understanding the complex ways in which fire affects ecosystem functioning at smaller scales and will inform ongoing modeling efforts. We report the results of a field study in a semi-arid savanna in northern Botswana during the transition from dry to wet season (Oct-Dec) in 2012 and 2013. The goals of this study were to: (1) characterize the multifaceted effect that late dry-season fires have on fluxes and radiative surface processes during green-up, and (2) describe the timescales over which these variables recover to non-burnt levels. Our study synthesizes a suite of data, including flux tower measurements, vegetation sampling, time-lapse photography and concurrent remotely sensed variables over plots with variable burn patterns. Albedo decreased immediately after fire, converging on unburned values 10 days post-burn. The magnitude and direction of this response was comparable to the albedo change elicited by strong rainfall events. Soil temperature and soil heat flux were not significantly modified by fire. Carbon fluxes showed no discernible difference from an unburned control site immediately after fire. There was a small burst in ecosystem respiration at immediately following the first post-fire rainfall event, returning to baseline values after 3 days. Persistent CO2 release, which we attribute to soil respiration, occurred for 10 days after successive strong wetting events, confirming the centrality of available moisture in determining ecosystem function. Fire delayed the green-up in some plots, but this effect was variable and short-lived. One month after fire there was no evidence of a difference in ground observations of greenness between burnt and control plots or plots that differed in their time of burning. We attribute the relatively ephemeral

  6. Changes of progesterone levels in the milk of dairy cows in post-partum

    Energy Technology Data Exchange (ETDEWEB)

    Yongpeng, Li

    1985-06-01

    Progesterone levels were measured by radioimmunoassay in the last milk of seven dairy cows in 5-75 days post-partum. The progesterone levels were from 0.1 to 1.5 ng/ml and averaged 0.4 +- 0.2 ng/ml for the last milk of the seven cows. A range of 0.3 to 0.7 ng/ml for average progesterone levels of the seven cows can be estimated. Two ovarian cycle activities in post-partum of cow No. 43 were observed and a ovulation on 15-20 days post-partum was revealed. The peak value after 20 days post-partum was 3.0 ng/ml. The progesterone level after peak value was declined, and reached to about 0.2 ng/ml on 35 days post-partum. The changes of ovarian activities were exhibited again in 35-55 days post-partum. The progesterone levels of cow No. 43 were lower in luteal phase oestrous cycles post-partum than that from the other cows in normal luteal phase oestrous cycles.

  7. Effects of weak magnetic fields on post-implantation damage in superconducting oxides

    International Nuclear Information System (INIS)

    Khait, Y.L.

    1996-01-01

    Experimentally verifiable effects of weak permanent magnetic fields (PMF's) acting during ion implantation in high-T c superconducting (HTSC) materials at T∼300 K on post-implantation damage (PID) and material parameters are considered. The presence of PMF's of H∼10 3 Oe during ion implantation can enlarge substantially the PID in HTSC materials implanted with ions of moderate energies (e.g. 200-400 keV) and dosage (10 11- 10 12 cm -3 ) at room temperature. The PMF-induced increase in the radiation damage causes the corresponding enhancement in the material resistivity R and reduction in the critical current j cir (measured after the cooling of the HTSC material down to T (L) c after the ion implantation). This is an extension of the PMF effects found experimentally (and explained theoretically) in semiconductors in our previous work. The experimentally verifiable PMF effects on the defect (atomic) migration and radiation damage is a generic consequence of the kinetic electron-related theory of atomic rate processes in solids. The theory links the PMF effects with electron transitions occurring in the nanometer vicinity of atoms overcoming energy barriers which affect exponentially rates of atomic (defect) diffusion. The magnetic field can enhance the number of downward electron transitions that accompany atomic (defect) jumps over energy barriers and synchronize with the jumps. This enhances exponentially the rates of defect migration out of thermal spikes that prevents the defects from fast recombination, and thus, the PMF increases the PID and changes correspondingly R and j cir . (orig.)

  8. Continuous Measurements of Canopy-level Solar-Induced Chlorophyll Fluorescence for Inferring Diurnal and Seasonal Dynamics of Photosynthesis in Crop Fields in the Midwestern USA

    Science.gov (United States)

    Miao, G.; Guan, K.; Yang, X.; Bernacchi, C.; DeLucia, E. H.; Cai, Y.; Masters, M. D.; Peng, B.

    2016-12-01

    Plants emitted photons of red and far-red light, called chlorophyll fluorescence, after sunlight absorption for photosynthesis. This solar-induced fluorescence (SIF) is generated simultaneously while plants actively photosynthesize. The link between photosynthesis and SIF resulting from the competition for the same excitation energy has long been investigated and applied for inferring the rate of photosynthesis. Recent development of continuous SIF observational technology is furthering the inferring potential as well as our understandings of fluctuations of SIF and photosynthesis with changes in environmental conditions. To better understand this photosynthesis-SIF link at multiple time scales and their relationships with environmental drivers, we deployed two newly developed tower-based SIF systems (FluoSpec) in a corn (Zea mays L., C4 plant) field and a soybean (Glycine max L., C3 plant) field at University of Illinois Energy Farm and conducted continuous near-surface SIF measurements at canopy scale from mid-growing season of 2016. Eddy covariance flux towers were installed in parallel at both sites for canopy-scale gas exchange measurements. Relationship between SIF and flux tower photosynthesis will be analyzed to derive the empirical models for photosynthesis retrieval from SIF signals. Preliminary results indicate that canopy SIF can reflect diurnal and seasonal dynamics of photosynthesis. Mechanistic analysis on SIF fluctuations and responses to environmental variations will be conducted as well for a closer look at mechanism of photosynthetic responses. Corn and soybean SIF and photosynthesis-SIF relationship will be compared to investigate the difference between C4 and C3 plants.

  9. Associations among body condition score, body weight, and reproductive performance in seasonal-calving dairy cattle.

    Science.gov (United States)

    Roche, J R; Macdonald, K A; Burke, C R; Lee, J M; Berry, D P

    2007-01-01

    The objective of the present study was to identify and quantify relationships between body condition score (BCS) and body weight (BW) in dairy cows with reproduction variables in pasture-based, seasonal-calving dairy herds. Over 2,500 lactation records from 897 spring-calving Holstein-Friesian dairy cows were used in the analyses. Eleven BCS- and 11 BW-related variables were generated, including observations at calving, nadir, planned start of mating (PSM), and first service, as well as days to nadir and the amount and rate of change between periods. The binary reproductive variables were cycling by PSM, mated in the first 21 d from PSM, pregnant to first service, and pregnant in the first 21, 42, and 84 d of the seasonal mating period. Generalized estimating equations were used to identify BCS and BW variables that significantly affected the probability of a successful reproductive outcome. After adjusting for the fixed effect of year of calving, parity (for cycling by PSM only), and the interval from calving to either first service or PSM, reproductive performance was found to be significantly affected by BW or BCS at key points, and by BCS and BW change during lactation. All reproductive response measures were negatively affected when BCS and BW measures indicated an increased severity and duration of the postpartum negative energy balance. In particular, cycling by PSM was positively associated with calving BCS, whereas pregnancy at 21, 42, and 84 d post-PSM were positively associated with nadir BCS and BW gain post-PSM, and negatively associated with BCS loss between calving and nadir. The results highlight the important role that BCS and BW loss has on reproductive performance, especially in seasonal-calving dairy systems because of the short period between calving and PSM.

  10. Effect of seasonal abiotic conditions and field margin habitat on the activity of Pandora neoaphidis inoculum on soil.

    Science.gov (United States)

    Baverstock, J; Clark, S J; Pell, J K

    2008-03-01

    The ability of the aphid pathogenic fungus Pandora neoaphidis to remain active in the absence of a resting stage through a combination of continuous infection and as conidia deposited on soil was assessed alongside the potential for planted field margins to act as a refuge for the fungus. P. neoaphidis was able to infect the pea aphid, Acyrthosiphon pisum, when maintained under controlled conditions that simulated those that occur seasonally in the UK. Although there was a significant inverse relationship between temperature and time-to-kill, with death occurring after 4.2, 6.9 and 13.6 days when maintained under fluctuating summer, autumn and winter temperatures, respectively, there were no additional statistically significant effects of photoperiod. The activity of inoculum on soil was indirectly assessed by baiting with A. pisum. Under controlled conditions P. neoaphidis remained active on soil and was able to infect aphids for up to 80 days. However, the percentage of aphids that became infected decreased from 76% on day 1 to 11% on day 80. Whereas there was little difference in the activity of conidia that had been maintained at 4 degrees C and 10 degrees C, activity at 18 degrees C was considerably reduced. Under field conditions the activity of inoculum was strongly influenced by season. On day 49 there was little or no activity during spring, summer or winter. However, during autumn a mean proportion of 0.08 aphids still became infected with P. neoaphidis. Margin type did not affect the activity of conidia nor was there a difference in activity between blocks that had regenerated naturally and those that had been planted. These results suggest that P. neoaphidis can infect aphids and remain active on soil under the abiotic conditions that occur seasonally in the UK and that this fungus may be able to persist annually without a resting stage.

  11. Season-to-Season Variations of Physiological Fitness Within a Squad of Professional Male Soccer Players

    Science.gov (United States)

    Clark, Niall A.; Edwards, Andrew M.; Morton, R. Hugh; Butterly, Ronald J.

    2008-01-01

    The purpose of this study was to examine season-to-season variations in physiological fitness parameters among a 1st team squad of professional adult male soccer players for the confirmatory purposes of identifying normative responses (immediately prior to pre-season training (PPS), mid-season (MID), and end-of-season (EOS)). Test-retest data were collected from a student population on the primary dependent variables of anaerobic threshold (AT) and maximal aerobic power (VO2 max) to define meaningful measurement change in excess of test-retest technical error between test-to-test performances. Participants from a pool of 42 professional soccer players were tested over a set sequence of tests during the 3-year period: 1) basic anthropometry, 2) countermovement jump (CMJ) tests 3) a combined AT and VO2 max test. Over the 3-year period there were no test-to-test changes in mean VO2 max performance exceeding pre-defined limits of test agreement (mean of eight measures: 61.6 ± 0.6 ml·kg-1·min-1). In contrast, VO2 at AT was significantly higher at the MID test occasion in seasons 2 (+4.8%; p = 0.04, p elite cohort between test-to-test occasions, VO2 max values did not vary significantly over the study which supports previous short-term observations suggesting a general ‘elite’ threshold of 60 ml·kg-1 min. Interestingly, AT significantly varied where VO2 max was stable and these variations also coincided with on- and off-seasons suggesting that AT is a better indication of acute training state than VO2 max. Key points Maximal aerobic power remains fairly stable across inter- and intra-season measurements. Anaerobic threshold appears more sensitive of training state confirming our earlier observations. The professional players tended to attain optimal performances at the mid-season interval over the 3 seasons, presumably prior to the development of accumulative fatigue. PMID:24150149

  12. Modeling of Future Changes in Seasonal Snowpack and Impacts on Summer Low Flows in Alpine Catchments

    Science.gov (United States)

    Jenicek, Michal; Seibert, Jan; Staudinger, Maria

    2018-01-01

    It is expected that an increasing proportion of the precipitation will fall as rain in alpine catchments in the future. Consequently, snow storage is expected to decrease, which, together with changes in snowmelt rates and timing, might cause reductions in spring and summer low flows. The objectives of this study were (1) to simulate the effect of changing snow storage on low flows during the warm seasons and (2) to relate drought sensitivity to the simulated snow storage changes at different elevations. The Swiss Climate Change Scenarios 2011 data set was used to derive future changes in air temperature and precipitation. A typical bucket-type catchment model, HBV-light, was applied to 14 mountain catchments in Switzerland to simulate streamflow and snow in the reference period and three future periods. The largest relative decrease in annual maximum SWE was simulated for elevations below 2,200 m a.s.l. (60-75% for the period 2070-2099) and the snowmelt season shifted by up to 4 weeks earlier. The relative decrease in spring and summer minimum runoff that was caused by the relative decrease in maximum SWE (i.e., elasticity), reached 40-90% in most of catchments for the reference period and decreased for the future periods. This decreasing elasticity indicated that the effect of snow on summer low flows is reduced in the future. The fraction of snowmelt runoff in summer decreased by more than 50% at the highest elevations and almost disappeared at the lowest elevations. This might have large implications on water availability during the summer.

  13. Theory of planned behaviour variables and objective walking behaviour do not show seasonal variation in a randomised controlled trial.

    Science.gov (United States)

    Williams, Stefanie L; French, David P

    2014-02-05

    Longitudinal studies have shown that objectively measured walking behaviour is subject to seasonal variation, with people walking more in summer compared to winter. Seasonality therefore may have the potential to bias the results of randomised controlled trials if there are not adequate statistical or design controls. Despite this there are no studies that assess the impact of seasonality on walking behaviour in a randomised controlled trial, to quantify the extent of such bias. Further there have been no studies assessing how season impacts on the psychological predictors of walking behaviour to date. The aim of the present study was to assess seasonal differences in a) objective walking behaviour and b) Theory of Planned Behaviour (TPB) variables during a randomised controlled trial of an intervention to promote walking. 315 patients were recruited to a two-arm cluster randomised controlled trial of an intervention to promote walking in primary care. A series of repeated measures ANCOVAs were conducted to examine the effect of season on pedometer measures of walking behaviour and TPB measures, assessed immediately post-intervention and six months later. Hierarchical regression analyses were conducted to assess whether season moderated the prediction of intention and behaviour by TPB measures. There were no significant differences in time spent walking in spring/summer compared to autumn/winter. There was no significant seasonal variation in most TPB variables, although the belief that there will be good weather was significantly higher in spring/summer (F = 19.46, p behaviour, or moderate the effects of TPB variables on intention or behaviour. Seasonality does not influence objectively measured walking behaviour or psychological variables during a randomised controlled trial. Consequently physical activity behaviour outcomes in trials will not be biased by the season in which they are measured. Previous studies may have overestimated the extent of

  14. Change in settings for early-season influenza vaccination among US adults, 2012 to 2013

    Directory of Open Access Journals (Sweden)

    Sarah J. Clark, MPH

    2016-12-01

    Full Text Available Vaccination in non-medical settings is recommended as a strategy to increase access to seasonal influenza vaccine. To evaluate change in early-season influenza vaccination setting, we analyzed data from the National Internet Flu Survey. Bivariate comparison of respondent characteristics by location of vaccination was assessed using chi-square tests. Multinomial logistic regression was performed to compare the predicted probability of being vaccinated in medical, retail, and mobile settings in 2012 vs 2013. In both 2012 and 2013, vaccination in medical settings was more likely among elderly adults, those with chronic conditions, and adults with a high school education or less. Adults 18–64 without a chronic condition had a lower probability of vaccination in the medical setting, and higher probability of vaccination in a retail or mobile setting, in 2013 compared to 2012. Adults 18–64 with a chronic condition had no change in their location of flu vaccination. Elderly adults had a lower probability of vaccination in the medical setting, and higher probability of vaccination in a retail setting, in 2013 compared to 2012. Non-medical settings continue to play an increasing role in influenza vaccination of adults, particularly for adults without a chronic condition and elderly adults. Retail and mobile settings should continue to be viewed as important mechanisms to ensure broad access to influenza vaccination.

  15. Synchronous seasonal change in fin whale song in the North Pacific.

    Directory of Open Access Journals (Sweden)

    Erin M Oleson

    Full Text Available Fin whale (Balaenoptera physalus song consists of down-swept pulses arranged into stereotypic sequences that can be characterized according to the interval between successive pulses. As in blue (B. musculus and humpback whales (Megaptera novaeangliae, these song sequences may be geographically distinct and may correlate with population boundaries in some regions. We measured inter-pulse intervals of fin whale songs within year-round acoustic datasets collected between 2000 and 2006 in three regions of the eastern North Pacific: Southern California, the Bering Sea, and Hawaii. A distinctive song type that was recorded in all three regions is characterized by singlet and doublet inter-pulse intervals that increase seasonally, then annually reset to the same shorter intervals at the beginning of each season. This song type was recorded in the Bering Sea and off Southern California from September through May and off Hawaii from December through April, with the song interval generally synchronized across all monitoring locations. The broad geographic and seasonal occurrence of this particular fin whale song type may represent a single population broadly distributed throughout the eastern Pacific with no clear seasonal migratory pattern. Previous studies attempting to infer population structure of fin whales in the North Pacific using synchronous individual song samples have been unsuccessful, likely because they did not account for the seasonal lengthening in song intervals observed here.

  16. Seasonal Changes in Atmospheric Noise Levels and the Annual Variation in Pigeon Homing Performance

    Science.gov (United States)

    Hagstrum, J. T.; McIsaac, H. P.; Drob, D. P.

    2015-12-01

    The remarkable navigational ability of homing pigeons (Columba livia) is influenced by a number of factors, an unknown one of which causes the "Wintereffekt"1 or annual variation in homing performance. Minima in homeward orientation and return speeds have been observed in winter, with maxima in summer, during repetitive pigeon releases from single sites near experimental lofts in Wilhelmshaven, Göttingen, and Munich, Germany, and near Pisa, Italy1-4. Overall the annual variation is more pronounced in northern Germany than Italy4, and both mature and juvenile cohorts respond to this seasonal factor. Older, more experienced pigeons are better at compensating for its effects than naïve ones, but are still affected after numerous releases. The narrow low-frequency band of atmospheric background noise (microbaroms; 0.1-0.3 Hz) also varies with an annual cycle that generally has higher amplitudes in winter than in summer depending on location5. In addition, homing pigeons, and possibly other birds, apparently use infrasonic signals of similar frequency as navigational cues6, and a seasonal variation in background noise levels could cause corresponding changes in signal-to-noise ratios and thus in homing performance. The annual variation in homing performance, however, was not observed during long-term pigeon releases at two sites in eastern North America. The annual and geographic variability in homing performance in the northern hemisphere can be explained to a first order by seasonal changes in infrasonic noise sources related to ocean storm activity, and to the direction and intensity of stratospheric winds. In addition, increased dispersion in departure bearings of individual birds for some North American releases were likely caused by additional infrasonic noise associated with severe weather events during tornado and Atlantic hurricane seasons. 1Kramer, G. & von Saint Paul, U., J. Ornithol. 97, 353-370 (1956); 2Wallraff, H. G., Z. Tierpsychol. 17, 82-113 (1960

  17. On the change of fall-out measured by monitoring post at the time of nuclear explosion

    International Nuclear Information System (INIS)

    Nagai, Tatsuo; Honda, Tadashi; Imai, Toshio

    1977-01-01

    The measurement of the spatial distribution of gamma-ray by monitoring posts has been continued. The measurement has been made with scintillation counters. The annual variation of gamma dose in no-rain season was recorded as background. The depth of snow showed some correlation with the level of the background gamma dose. Natural radioactivity in the air emitted from the terrestrial surface may cause the activity of the air. The relation between rain and dose rate was investigated. The higher dose rate than the background was seen during rain fall. The increase of dose rate was observed after the Chinese nuclear explosion. After the analysis of data from various monitoring posts, the trace line of fall-out activity was determined. The trace of 500 mb, which means about 10 KT of explosion, did not cross Japan, and the trace of 300 mb, meaning 100 KT of explosion, was just over Japan. The movement of the fall out along the trace line was definitely observed. (Kato, T.)

  18. 18 CFR 157.34 - Notice of open season.

    Science.gov (United States)

    2010-04-01

    ... provide reasonable public notice of an open season through methods including postings on Internet Web... of the prospective applicant's affiliated sales and marketing units and Energy Affiliates involved in... structure of marketing and sales units and any Energy Affiliates involved in the production of natural gas...

  19. Seasonal Changes in Tropospheric Ozone Concentrations over South Korea and Its Link to Ozone Precursors

    Science.gov (United States)

    Jung, H. C.; Moon, B. K.; Wie, J.

    2017-12-01

    Concentration of tropospheric ozone over South Korea has steadily been on the rise in the last decades, mainly due to rapid industrializing and urbanizing in the Eastern Asia. To identify the characteristics of tropospheric ozone in South Korea, we fitted a sine function to the surface ozone concentration data from 2005 to 2014. Based on fitted sine curves, we analyzed the shifts in the dates on which ozone concentration reached its peak in the calendar year. Ozone monitoring sites can be classified into type types: where the highest annual ozone concentration kept occurring sooner (Esites) and those that kept occurring later (Lsites). The seasonal analysis shows that the surface ozone had increased more rapidly in Esites than in Lsites in the past decade during springtime and vice-versa during summertime. We tried to find the reason for the different seasonal trends with the relationship between ozone and ozone precursors. As a result, it was found that the changes in the ground-level ozone concentration in the spring and summer times are considerably influenced by changes in nitrogen dioxide concentration, and this is closely linked to the destruction (production) process of ozone by nitrogen dioxide in spring (summer). The link between tropospheric ozone and nitrogen dioxide discussed in this study will have to be thoroughly examined through climate-chemistry modeling in the future. Acknowledgements This research was supported by the Korea Ministry of Environment (MOE) as "Climate Change Correspondence Program."

  20. Vaccine-critical videos on YouTube and their impact on medical students' attitudes about seasonal influenza immunization: a pre and post study.

    Science.gov (United States)

    Robichaud, Pierre; Hawken, Steven; Beard, Leslie; Morra, Dante; Tomlinson, George; Wilson, Kumanan; Keelan, Jennifer

    2012-05-28

    YouTube is a video-sharing platform that is increasingly utilized to share and disseminate health-related information about immunization. Using a pre-post survey methodology, we compared the impact of two of the most popular YouTube videos discussing seasonal influenza vaccine, both vaccine-critical, on the attitudes towards immunizing of first year medical students attending a Canadian medical school. Forty-one medical students were randomized to view either a scientifically styled, seemingly "evidence-based", vaccine-critical video or a video using anecdotal stories of harms and highly sensationalized imagery. In the pre-intervention survey, medical students frequently used YouTube for all-purposes, while 42% used YouTube for health-related purposes and 12% used YouTube to search for health information. While medical students were generally supportive of immunizing, there was suboptimal uptake of annual influenza vaccine reported, and a subset of our study population expressed vaccine-critical attitudes and behaviors with respect to seasonal influenza. Overall there was no significant difference in pre to post attitudes towards influenza immunization nor were there any differences when comparing the two different vaccine-critical videos. The results of our study are reassuring in that they suggest that medical students are relatively resistant to the predominately inaccurate, vaccine-critical messaging on YouTube, even when the message is framed as scientific reasoning. Further empirical work is required to test the popular notion that information disseminated through social media platforms influences health-related attitudes and behaviors. However, our study suggests that there is an opportunity for public health to leverage YouTube to communicate accurate and credible information regarding influenza to medical students and others. Copyright © 2012 Elsevier Ltd. All rights reserved.

  1. Glenohumeral range of motion (ROM) and isometric strength of professional team handball athletes, part III: changes over the playing season.

    Science.gov (United States)

    Fieseler, Georg; Jungermann, Philipp; Koke, Alexander; Irlenbusch, Lars; Delank, Karl-Stefan; Schwesig, René

    2015-12-01

    The aim of our study was to investigate the relation of workload on range of motion and isometric strength of team handball athletes' shoulders over a competitive season. 31 Professional male handball athletes underwent clinical shoulder examinations. Athletes were examined subsequently during the complete playing season (week 0, 6, 22 and 40) to determine bilateral isometric shoulder rotational strength and active range of motion (ROM). In addition, relative (intraclass correlation coefficients (ICC) and absolute (standard error of measurement) reliability were calculated. Intraobserver reliability was excellent (ICC 0.76-0.98) for isometric strength and flexibility measurements. Internal rotation (IR) and total arc ROM in the throwing shoulder (TS) decreased significantly (p handball players' shoulders changed significantly from the beginning to the end of a season. More specifically, the repetitive forces accumulated during the competitive season resulted in altered GIRD, ERG and isometric strength of the dominant glenohumeral joint.

  2. Tendon neuroplastic training reduces tendon pain and muscle inhibition in-season: Changing the way we think about exercise

    NARCIS (Netherlands)

    Rio, E.; Kidgell, D.; Van Ark, M.; Zwerver, J; Sheek, I.; Moseley, G.L.; Gaida, J.; Docking, S.; Cook, J.

    2015-01-01

    Introduction: Patellar tendon pain is at its highest in-season but there are no published data of successful management when athletes are playing and training. Furthermore, there are changes to the cortical control of the quadriceps in patellar tendinopathy (including excess quadriceps inhibition)

  3. A Typology to Explain Changing Social Networks Post Stroke.

    Science.gov (United States)

    Northcott, Sarah; Hirani, Shashivadan P; Hilari, Katerina

    2018-05-08

    Social network typologies have been used to classify the general population but have not previously been applied to the stroke population. This study investigated whether social network types remain stable following a stroke, and if not, why some people shift network type. We used a mixed methods design. Participants were recruited from two acute stroke units. They completed the Stroke Social Network Scale (SSNS) two weeks and six months post stroke and in-depth interviews 8-15 months following the stroke. Qualitative data was analysed using Framework Analysis; k-means cluster analysis was applied to the six-month data set. Eighty-seven participants were recruited, 71 were followed up at six months, and 29 completed in-depth interviews. It was possible to classify all 29 participants into one of the following network types both prestroke and post stroke: diverse; friends-based; family-based; restricted-supported; restricted-unsupported. The main shift that took place post stroke was participants moving out of a diverse network into a family-based one. The friends-based network type was relatively stable. Two network types became more populated post stroke: restricted-unsupported and family-based. Triangulatory evidence was provided by k-means cluster analysis, which produced a cluster solution (for n = 71) with comparable characteristics to the network types derived from qualitative analysis. Following a stroke, a person's social network is vulnerable to change. Explanatory factors for shifting network type included the physical and also psychological impact of having a stroke, as well as the tendency to lose contact with friends rather than family.

  4. Seasonal and multi-year surface displacements measured by DInSAR in a High Arctic permafrost environment

    Science.gov (United States)

    Rudy, Ashley C. A.; Lamoureux, Scott F.; Treitz, Paul; Short, Naomi; Brisco, Brian

    2018-02-01

    Arctic landscapes undergo seasonal and long-term changes as the active layer thaws and freezes, which can result in localized or irregular subsidence leading to the formation of thermokarst terrain. Differential Interferometric Synthetic Aperture Radar (DInSAR) is a technique capable of measuring ground surface displacements resulting from thawing permafrost at centimetre precision and is quickly gaining acceptance as a means of measuring ground displacement in permafrost regions. Using RADARSAT-2 stacked DInSAR data from 2013 and 2015 we determined the magnitude and patterns of land surface change in a continuous permafrost environment. At our study site situated in the Canadian High Arctic, DInSAR seasonal ground displacement patterns were consistent with field observations of permafrost degradation. As expected, many DInSAR values are close to the detection threshold (i.e., 1 cm) and therefore do not indicate significant change; however, DInSAR seasonal ground displacement patterns aligned well with climatological and soil conditions and offer geomorphological insight into subsurface processes in permafrost environments. While our dataset is limited to two years of data representing a three-year time period, the displacements derived from DInSAR provide insight into permafrost change in a High Arctic environment and demonstrate that DInSAR is an applicable tool for understanding environmental change in remote permafrost regions.

  5. Impacts of climate change on the seasonality of low flows in 134 catchments in the river Rhine basin using an ensemble of bias-corrected regional climate simulations.

    NARCIS (Netherlands)

    Demirel, M.C.; Booij, Martijn J.; Hoekstra, Arjen Ysbert

    2013-01-01

    The impacts of climate change on the seasonality of low flows were analysed for 134 sub-catchments covering the River Rhine basin upstream of the Dutch-German border. Three seasonality indices for low flows were estimated, namely the seasonality ratio (SR), weighted mean occurrence day (WMOD) and

  6. Metabolite changes in nine different soybean varieties grown under field and greenhouse conditions.

    Science.gov (United States)

    Maria John, K M; Natarajan, Savithiry; Luthria, Devanand L

    2016-11-15

    Global food security remains a worldwide concern due to changing climate, increasing population, and reduced agriculture acreages. Greenhouse cultivation increases productivity by extending growing seasons, reducing pest infestations and providing protection against short term drastic weather fluctuations like frost, heat, rain, and wind. In the present study, we examined and compared the metabolic responses of nine soybean varieties grown under field and greenhouse conditions. Extracts were assayed by GC-FID, GC-MS, and LC-MS for the identification of 10 primary (amino acids, organic acids, and sugars) and 10 secondary (isoflavones, fatty acid methyl esters) metabolites. Sugar molecules (glucose, sucrose, and pinitol) and isoflavone aglycons were increased but the isoflavones glucoside content decreased in the greenhouse cultivated soybeans. The amino acids and organic acids varied between the varieties. The results show that clustering (PCA and PLS-DA) patterns of soybean metabolites were significantly influenced by the genetic variation and growing conditions. Published by Elsevier Ltd.

  7. Seasonal photosynthetic activity in evergreen conifer leaves monitored with spectral reflectance

    Science.gov (United States)

    Wong, C. Y.; Gamon, J. A.

    2013-12-01

    Boreal evergreen conifers must maintain photosynthetic systems in environments where temperatures vary greatly across seasons from high temperatures in the summer to freezing levels in the winter. This involves seasonal downregulation and photoprotection during periods of extreme temperatures. To better understand this downregulation, seasonal dynamics of photosynthesis of lodgepole (Pinus contorta D.) and ponderosa pine (Pinus ponderosa D.) were monitored in Edmonton, Canada over two years. Spectral reflectance at the leaf and stand scales was measured weekly and the Photochemical Reflectance Index (PRI), often used as a proxy for chlorophyll and carotenoid pigment levels and photosynthetic light-use efficiency (LUE), was used to track the seasonal dynamics of photosynthetic activity. Additional physiological measurements included leaf pigment content, chlorophyll fluorescence, and gas exchange. All the metrics indicate large seasonal changes in photosynthetic activity, with a sharp transition from winter downregulation to active photosynthesis in the spring and a more gradual fall transition into winter. The PRI was a good indicator of several other variables including seasonally changing photosynthetic activity, chlorophyll fluorescence, photosynthetic LUE, and pigment pool sizes. Over the two-year cycle, PRI was primarily driven by changes in constitutive (chlorophyll:carotenoid) pigment levels correlated with seasonal photosynthetic activity, with a much smaller variation caused by diurnal changes in xanthophyll cycle activity (conversion between violaxanthin & zeaxanthin). Leaf and canopy scale PRI measurements exhibited parallel responses during the winter-spring transition. Together, our findings indicate that evergreen conifers photosynthetic system possesses a remarkable degree of resilience in response to large temperature changes across seasons, and that optical remote sensing can be used to observe the seasonal effects on photosynthesis and

  8. Quantification of maceration changes using post mortem MRI in fetuses

    International Nuclear Information System (INIS)

    Montaldo, P.; Addison, S.; Oliveira, V.; Lally, P. J.; Taylor, A. M.; Sebire, N. J.; Thayyil, S.; Arthurs, O. J.

    2016-01-01

    Post mortem imaging is playing an increasingly important role in perinatal autopsy, and correct interpretation of imaging changes is paramount. This is particularly important following intra-uterine fetal death, where there may be fetal maceration. The aim of this study was to investigate whether any changes seen on a whole body fetal post mortem magnetic resonance imaging (PMMR) correspond to maceration at conventional autopsy. We performed pre-autopsy PMMR in 75 fetuses using a 1.5 Tesla Siemens Avanto MR scanner (Erlangen, Germany). PMMR images were reported blinded to the clinical history and autopsy data using a numerical severity scale (0 = no maceration changes to 2 = severe maceration changes) for 6 different visceral organs (total 12). The degree of maceration at autopsy was categorized according to severity on a numerical scale (1 = no maceration to 4 = severe maceration). We also generated quantitative maps to measure the liver and lung T 2 . The mean PMMR maceration score correlated well with the autopsy maceration score (R 2 = 0.93). A PMMR score of ≥4.5 had a sensitivity of 91 %, specificity of 64 %, for detecting moderate or severe maceration at autopsy. Liver and lung T 2 were increased in fetuses with maceration scores of 3–4 in comparison to those with 1–2 (liver p = 0.03, lung p = 0.02). There was a good correlation between PMMR maceration score and the extent of maceration seen at conventional autopsy. This score may be useful in interpretation of fetal PMMR

  9. Adiposity, post-diagnosis weight change, and risk of cardiovascular events among early-stage breast cancer survivors.

    Science.gov (United States)

    Cespedes Feliciano, Elizabeth M; Kwan, Marilyn L; Kushi, Lawrence H; Weltzien, Erin K; Castillo, Adrienne L; Caan, Bette J

    2017-04-01

    Little research examines whether adiposity or post-diagnosis weight changes influence Cardiovascular disease (CVD) among breast cancer patients for whom effects may differ due to treatment and recovery. We studied Stage I-III breast cancer survivors 18 to  diagnosis and weight and waist circumference (WC) around 24 months post diagnosis. Using Cox models for time to incident coronary artery disease, heart failure, valve abnormality, arrhythmia, stroke, or CVD death, we examined at-diagnosis body mass index (BMI, n = 3109) and post-diagnosis WC (n = 1898) and weight change (n = 1903, stable, ±5 to  diagnosis, 25% of women gained and 14% lost ≥10-lbs; mean (SD) WC was 90 (15) cm. Over a median of 8.28 years, 915 women developed CVD. BMI 25-30-kg/m 2 (vs. BMI diagnosis weight change had no association with CVD. Extreme adiposity and any elevation in WC increased risk of CVD among breast cancer survivors; however, changes in weight in the early post-diagnosis period were not associated with CVD. Survivors with high WC and existing CVD risk factors should be monitored.

  10. Seasonal Variation in Group Size Is Related to Seasonal Variation in Neuropeptide Receptor Density.

    Science.gov (United States)

    Wilson, Leah C; Goodson, James L; Kingsbury, Marcy A

    2016-01-01

    In many species, seasonal variation in grouping behavior is widespread, with shifts towards territoriality in the breeding season and grouping in the winter. Compared to the hormonal and neural mechanisms of seasonal territorial aggression, the mechanisms that promote seasonal grouping have received little attention. We collected brains in spring and winter from wild-caught males of two species of emberizid sparrows that seasonally flock (the field sparrow, Spizella pusilla, and the dark-eyed junco, Junco hyemalis) and two species that do not seasonally flock (the song sparrow, Melospiza melodia, and the eastern towhee, Pipilo erythrophthalmus). We used receptor autoradiography to quantify seasonal plasticity in available binding sites for three neuropeptides known to influence social behavior. We examined binding sites for 125I-vasoactive intestinal polypeptide (VIP), 125I-sauvagine (SG, a ligand for corticotropin-releasing hormone receptors) and 125I-ornithine vasotocin analog (OVTA, a ligand for the VT3 nonapeptide). For all species and ligands, brain areas that exhibited a seasonal pattern in binding density were characterized by a winter increase. Compared to nonflocking species, seasonally flocking species showed different binding patterns in multiple brain areas. Furthermore, we found that winter flocking was associated with elevated winter 125I-VIP binding density in the medial amygdala, as well as 125I-VIP and 125I-OVTA binding density in the rostral arcopallium. While the functional significance of the avian rostral arcopallium is unclear, it may incorporate parts of the pallial amygdala. Our results point to this previously undescribed area as a likely hot spot of social modulation. © 2016 S. Karger AG, Basel.

  11. Revisiting the coupling between NDVI trends and cropland changes in the Sahel drylands

    DEFF Research Database (Denmark)

    Tong, Xiaoye; Brandt, Martin Stefan; Hiernaux, Pierre

    2017-01-01

    The impact of human activities via land use/cover changes on NDVI trends is critical for an improved understanding of satellite-observed changes in vegetation productivity in drylands. The dominance of positive NDVI trends in the Sahel, the so-called re-greening, is sometimes interpreted...... as a combined effect of an increase in rainfall and cropland expansion or agricultural intensification. Yet, the impact of changes in land use has yet to be thoroughly tested and supported by empirical evidence. At present, no studies have considered the importance of the different seasonal NDVI signals...... of cropped and fallowed fields when interpreting NDVI trends, as both field types are commonly merged into a single ‘cropland’ class. We make use of the distinctly different phenology of cropped and fallowed fields and use seasonal NDVI curves to separate these two field types. A fuzzy classifier is applied...

  12. Extended season for northern butterflies.

    Science.gov (United States)

    Karlsson, Bengt

    2014-07-01

    Butterflies are like all insects in that they are temperature sensitive and a changing climate with higher temperatures might effect their phenology. Several studies have found support for earlier flight dates among the investigated species. A comparative study with data from a citizen science project, including 66 species of butterflies in Sweden, was undertaken, and the result confirms that most butterfly species now fly earlier during the season. This is especially evident for butterflies overwintering as adults or as pupae. However, the advancement in phenology is correlated with flight date, and some late season species show no advancement or have even postponed their flight dates and are now flying later in the season. The results also showed that latitude had a strong effect on the adult flight date, and most of the investigated species showed significantly later flights towards the north. Only some late flying species showed an opposite trend, flying earlier in the north. A majority of the investigated species in this study showed a general response to temperature and advanced their flight dates with warmer temperatures (on average they advanced their flight dates by 3.8 days/°C), although not all species showed this response. In essence, a climate with earlier springs and longer growing seasons seems not to change the appearance patterns in a one-way direction. We now see butterflies on the wings both earlier and later in the season and some consequences of these patterns are discussed. So far, studies have concentrated mostly on early season butterfly-plant interactions but also late season studies are needed for a better understanding of long-term population consequences.

  13. Melanopsin-Mediated Acute Light Responses Measured in Winter and in Summer: Seasonal Variations in Adults with and without Cataracts

    Directory of Open Access Journals (Sweden)

    Mirjam Münch

    2017-09-01

    Full Text Available Seasonal adaptation is a ubiquitous behavior seen in many species on both global hemispheres and is conveyed by changing photoperiods. In humans this seasonal adaptation is less apparent, in part because changes in daylength are masked by the use of electrical lighting at night. On the other hand, cataracts which reduce light transmission, may compound seasonal changes related to the reduced daylength of winter. To better understand the effects of different photoperiod lengths in healthy adults without and with cataracts, we tested their melanopsin-mediated light responses in summer vs. winter. Fifty-two participants (mean age 67.4 years; 30 with bilateral cataracts and 22 age-matched controls with clear lenses; pseudophakes were tested twice, once in summer and once in winter. At each test session we assessed the electroretinogram and pupil responses during daytime and we determined melatonin suppression, subjective sleepiness and mood in response to light exposure in the evening. Circadian rest-activity cycles and sleep from activity recordings were also analyzed for both seasons. Both groups had similar visual function. There were no seasonal differences in the electroretinogram. For the pupil responses to bright blue light, the post-illumination pupil response (PIPR was greater in winter than summer in pseudophakes, but not in cataract participants, whereas melatonin suppression to acute light exposure showed no differences between both groups and seasons. Overall, intra-daily variability of rest-activity was worse in winter but participants felt sleepier and reported worse mood at the laboratory in evening time in the summer. Those with cataracts had poorer sleep quality with lower sleep efficiency, and higher activity during sleep in winter than summer. In this study, the PIPR showed a seasonal variation in which a larger response was found during winter. This variation was only detected in participants with a clear intraocular lens. In

  14. Annual and Seasonal Changes in the Structure of Litter-Dwelling Ant Assemblages (Hymenoptera: Formicidae in Atlantic Semideciduous Forests

    Directory of Open Access Journals (Sweden)

    Flávio Siqueira de Castro

    2012-01-01

    Full Text Available We surveyed ant fauna in the leaf litter in an Atlantic Semideciduous forest in the State Park of Rio Doce (PERD. The work aimed to produce basic information about habitat effects on diversity, as well as about how the ant fauna in a such buffered forest habitat, as the litter layer, could respond the climate variation in a short and long term. We sampled two years in two distinct forest physiognomies, which respond to different geomorphologic backgrounds, in dry and rainy seasons. Species composition, richness and abundance of these forests were distinct. However, both forests hosted similar numbers of rare and specialized, habitat demanding species, thus suggesting both are similarly well preserved, despite distinct physiognomies. However, the lower and more open forest was, more susceptible to dry season effects, showing a steeper decline in species numbers in such season, but similar numbers in the wet seasons. The pattern varied between years, which corroborates the hypothesis of a strongly variable community in response to subtle climatic variation among years. The present results are baselines for future long term monitoring projects, and could support protocols for early warnings of global climatic changes effects on biodiversity.

  15. Changes in cold tolerance due to a 14-day stay in the Canadian Arctic

    Science.gov (United States)

    Livingstone, S. D.; Romet, T.; Keefe, A. A.; Nolan, R. W.

    1996-12-01

    Responses to cold exposure tests both locally and of the whole body were examined in subjects who stayed in the Arctic (average maximum and minimum temperatures -11 and -21° C respectively) for 14 days of skiing and sleeping in tents. These changes were compared to responses in subjects living working in Ottawa, Canada (average max. and min. temperatures -5 and -11° C respectively). The tests were done before the stay in the Arctic (Pre), immediately after the return (Post 1) and approximately 32 days after the return (Post 2). For the whole-body cold exposure each subject, wearing only shorts and lying on a rope mesh cot, was exposed to an ambient temperature of 10° C. There was no consistent response in the changes of metabolic or body temperature to this exposure in either of groups and, in addition, the changes over time were variable. Cold induced vasodilatation (CIVD) was determined by measuring temperature changes in the middle finger of the nondominant hand upon immersion in ice water for 30 min. CIVD was depressed after the Arctic exposure whilst during the Post 2 testing, although variable, did not return to the Pre values; the responses of the control group were similar. These results indicate that normal seasonal changes may be as important in adaptation as a stay in the Arctic. Caution is advised in the separation of seasonal effects when examining the changes in adaptation after exposure to a cold environment.

  16. Projecting the impact of climate change on phenology of winter wheat in northern Lithuania.

    Science.gov (United States)

    Juknys, Romualdas; Velička, Rimantas; Kanapickas, Arvydas; Kriaučiūnienė, Zita; Masilionytė, Laura; Vagusevičienė, Ilona; Pupalienė, Rita; Klepeckas, Martynas; Sujetovienė, Gintarė

    2017-10-01

    Climate warming and a shift in the timing of phenological phases, which lead to changes in the duration of the vegetation period may have an essential impact on the productivity of winter crops. The main purpose of this study is to examine climate change-related long-term (1961-2015) changes in the duration of both initial (pre-winter) and main (post-winter) winter wheat vegetation seasons and to present the projection of future phenological changes until the end of this century. Delay and shortening of pre-winter vegetation period, as well as the advancement and slight extension of the post-winter vegetation period, resulted in the reduction of whole winter wheat vegetation period by more than 1 week over the investigated 55 years. Projected changes in the timing of phenological phases which define limits of a main vegetation period differ essentially from the observed period. According to pessimistic (Representative Concentration Pathways 8.5) scenario, the advancement of winter wheat maturity phase by almost 30 days and the shortening of post-winter vegetation season by 15 days are foreseen for a far (2071-2100) projection. An increase in the available chilling amount is specific not only to the investigated historical period (1960-2015) but also to the projected period according to the climate change scenarios of climate warming for all three projection periods. Consequently, the projected climate warming does not pose a threat of plant vernalization shortage in the investigated geographical latitudes.

  17. Asynchronous changes in phenology of migrating Broad-tailed Hummingbirds and their early-season nectar resources.

    Science.gov (United States)

    McKinney, Amy M; CaraDonna, Paul J; Inouye, David W; Barr, Billy; Bertelsen, C David; Waser, Nickolas M

    2012-09-01

    Phenological advancements driven by climate change are especially pronounced at higher latitudes, so that migrants from lower latitudes may increasingly arrive at breeding grounds after the appearance of seasonal resources. To explore this possibility, we compared dates of first arrival of Broad-tailed Hummingbirds (Selasphorus platycercus) to dates of flowering of plants they visit for nectar. Near the southern limit of the breeding range, neither hummingbird arrival nor first flowering dates have changed significantly over the past few decades. At a nearby migration stopover site, first flowering of a major food plant has advanced, but peak flowering has not. Near the northern limit of the breeding range, first and peak flowering of early-season food plants have shifted to earlier dates, resulting in a shorter interval between appearance of first hummingbirds and first flowers. If phenological shifts continue at current rates, hummingbirds will eventually arrive at northern breeding grounds after flowering begins, which could reduce their nesting success. These results support the prediction that migratory species may experience the greatest phenological mismatches at the poleward limits of their migration. A novel hypothesis based on these results posits that the poleward limit for some species may contract toward lower latitudes under continued warming.

  18. Climate-induced seasonal changes in smallmouth bass growth rate potential at the southern range extent

    Science.gov (United States)

    Middaugh, Christopher R.; Kessinger, Brin; Magoulick, Daniel D.

    2018-01-01

    Temperature increases due to climate change over the coming century will likely affect smallmouth bass (Micropterus dolomieu) growth in lotic systems at the southern extent of their native range. However, the thermal response of a stream to warming climate conditions could be affected by the flow regime of each stream, mitigating the effects on smallmouth bass populations. We developed bioenergetics models to compare change in smallmouth bass growth rate potential (GRP) from present to future projected monthly stream temperatures across two flow regimes: runoff and groundwater-dominated. Seasonal differences in GRP between stream types were then compared. The models were developed for fourteen streams within the Ozark–Ouachita Interior Highlands in Arkansas, Oklahoma and Missouri, USA, which contain smallmouth bass. In our simulations, smallmouth bass mean GRP during summer months decreased by 0.005 g g−1 day−1 in runoff streams and 0.002 g g−1 day−1 in groundwater streams by the end of century. Mean GRP during winter, fall and early spring increased under future climate conditions within both stream types (e.g., 0.00019 g g−1 day−1 in runoff and 0.0014 g g−1 day−1 in groundwater streams in spring months). We found significant differences in change in GRP between runoff and groundwater streams in three seasons in end-of-century simulations (spring, summer and fall). Potential differences in stream temperature across flow regimes could be an important habitat component to consider when investigating effects of climate change as fishes from various flow regimes that are relatively close geographically could be affected differently by warming climate conditions.

  19. Secular trends in seasonal variation in birth weight

    DEFF Research Database (Denmark)

    Jensen, Camilla Bjørn; Gamborg, M; Raymond, K

    2015-01-01

    and phase of the yearly cycles to change. RESULTS: There was a clear seasonal pattern in BW which, however, changed gradually across the study period. The highest BWs were seen during fall (September - October) from 1936 to 1963, but a new peak gradually grew from the early 1940s during early summer (May...... again. Sunshine did not explain the seasonal variation in BW. CONCLUSION: There was a clear seasonal pattern in BW in Denmark 1936-1989, which however changed across the study period. Throughout the study period we observed a peak in BW during the fall, but gradually, starting in the early 1940s...

  20. Changing Regimes: Governmentality and Education Policy in Post-Apartheid South Africa

    Science.gov (United States)

    Christie, Pam

    2006-01-01

    This article applies Foucault's notion of governmentality to educational restructuring in post-apartheid South Africa. It argues that the nature of government in a modern state entails engaging with particular practices and domains of knowledge, which themselves constrain the changes that are conceivable and credible. Using Foucault's concepts of…

  1. Change detection of bare areas in the Xolobeni region, South Africa ...

    African Journals Online (AJOL)

    Rebekah

    study used remote sensing as a tool to provide some information on the ... seasonal crop lands have been severely degraded by water and wind .... the accuracy of classified data was critical to the quality of the post .... Agone, V & Bhamare, SM 2012, ' Change detection of vegetation cover using remote sensing and GIS',.

  2. Entropy of stable seasonal rainfall distribution in Kelantan

    Science.gov (United States)

    Azman, Muhammad Az-zuhri; Zakaria, Roslinazairimah; Satari, Siti Zanariah; Radi, Noor Fadhilah Ahmad

    2017-05-01

    Investigating the rainfall variability is vital for any planning and management in many fields related to water resources. Climate change can gives an impact of water availability and may aggravate water scarcity in the future. Two statistics measurements which have been used by many researchers to measure the rainfall variability are variance and coefficient of variation. However, these two measurements are insufficient since rainfall distribution in Malaysia especially in the East Coast of Peninsular Malaysia is not symmetric instead it is positively skewed. In this study, the entropy concept is used as a tool to measure the seasonal rainfall variability in Kelantan and ten rainfall stations were selected. In previous studies, entropy of stable rainfall (ESR) and apportionment entropy (AE) were used to describe the rainfall amount variability during years for Australian rainfall data. In this study, the entropy of stable seasonal rainfall (ESSR) is suggested to model rainfall amount variability during northeast monsoon (NEM) and southwest monsoon (SWM) seasons in Kelantan. The ESSR is defined to measure the long-term average seasonal rainfall amount variability within a given year (1960-2012). On the other hand, the AE measures the rainfall amounts variability across the months. The results of ESSR and AE values show that stations in east coastline are more variable as compared to other stations inland for Kelantan rainfall. The contour maps of ESSR for Kelantan rainfall stations are also presented.

  3. Climate change in winter versus the growing-season leads to different effects on soil microbial activity in northern hardwood forests

    Science.gov (United States)

    Sorensen, P. O.; Templer, P. H.; Finzi, A.

    2014-12-01

    Mean winter air temperatures have risen by approximately 2.5˚ C per decade over the last fifty years in the northeastern U.S., reducing the maximum depth of winter snowpack by approximately 26 cm over this period and the duration of winter snow cover by 3.6 to 4.2 days per decade. Forest soils in this region are projected to experience a greater number of freeze-thaw cycles and lower minimum winter soil temperatures as the depth and duration of winter snow cover declines in the next century. Climate change is likely to result not only in lower soil temperatures during winter, but also higher soil temperatures during the growing-season. We conducted two complementary experiments to determine how colder soils in winter and warmer soils in the growing-season affect microbial activity in hardwood forests at Harvard Forest, MA and Hubbard Brook Experimental Forest, NH. A combination of removing snow via shoveling and buried heating cables were used to induce freeze-thaw events during winter and to warm soils 5˚C above ambient temperatures during the growing-season. Increasing the depth and duration of soil frost via snow-removal resulted in short-term reductions in soil nitrogen (N) production via microbial proteolytic enzyme activity and net N mineralization following snowmelt, prior to tree leaf-out. Declining mass specific rates of carbon (C) and N mineralization associated with five years of snow removal at Hubbard Brook Experimental Forest may be an indication of microbial physiological adaptation to winter climate change. Freeze-thaw cycles during winter reduced microbial extracellular enzyme activity and the temperature sensitivity of microbial C and N mineralization during the growing-season, potentially offsetting nutrient and soil C losses due to soil warming in the growing-season. Our multiple experimental approaches show that winter climate change is likely to contribute to reduced microbial activity in northern hardwood forests.

  4. Exploring changes in rainfall intensity and seasonal variability in the Southeastern U.S.: Stakeholder engagement, observations, and adaptation

    Directory of Open Access Journals (Sweden)

    Daniel R. Dourte

    2015-01-01

    Full Text Available The distribution of rainfall has major impacts in agriculture, affecting the soil, hydrology, and plant health in agricultural systems. The goal of this study was to test for recent changes in rainfall intensity and seasonal rainfall variability in the Southeastern U.S. by exploring the data collaboratively with agricultural stakeholders. Daily rainfall records from the Global Historical Climatology Network were used to analyze changes in rain intensity and seasonal rainfall variability. During the last 30 years (1985–2014, there has been a significant change (53% increase in the number of extreme rainfall days (>152.4 mm/day and there have been significant decreases in the number of moderate intensity (12.7–25.4 mm/day and heavy (25.4–76.2 mm/day rainfall days in the Southeastern U.S., when compared to the previous 30-year period (1955–1984. There have also been significant decreases in the return period of months in which greater than half of the monthly total rain occurred in a single day; this is an original, stakeholder-developed rainfall intensity metric. The variability in spring and summer rainfall increased during the last 30 years, but winter and fall showed less variability in seasonal totals in the last 30 years. In agricultural systems, rainfall is one of the leading factors affecting yield variability; so it can be expected that more variable rainfall and more intense rain events could bring new challenges to agricultural production. However, these changes can also present opportunities for producers who are taking measures to adjust management strategies to make their systems more resilient to increased rain intensity and variability.

  5. Effects of Seasonal Changes, Age and Smoking on Haemostatic Factors and Thyroxine Level in Egyptian Men

    International Nuclear Information System (INIS)

    Kamal, T.H.; Bahgat, M. M.; Haggag, A. M.; Taha, M. E.

    2002-01-01

    ONE hundred and twenty male volunteers arranged into 6 equal groups participated in the present study to investigate the influence of age, smoking and season on clot formation, clot lysis and thyroxine hormone. Erythrocyte sedimentation rate, clotting time, platelet count, haemoglobin content, red blood cell count, haematocrit, total leukocytic count, fibrinogen, prothrombin time and concentration, partial thromboplastin time, factor V, VIII, plasminogen and thyroxine hormone were estimated in each group. The effect of age was studied by comparing young individuals (11-16 years) with adult non smokers (30-40 years) . Simultaneously adult non smokers were compared to adult smokers to evaluate the effect of smoking.Three groups: young , adult non smokers and adult smokers during winter were compared with their corresponding groups in summer to assess the season effect.The results revealed that most changes in the three groups were due to temperature variation and the young group had a better thermoregulation control than both adult groups .In non smoker adult group winter caused hypercoagulation with a concomitant increase in fibrinolytic activity as a protective mechanism against thrombus formation. Smoking caused disturbances in many coagulation factors and interaction between smoking and season is evident causing vascular disturbances. In summer smokers are more liable to bleeding, while in winter they are more liable to thrombus formation providing the other condition interfering with bleeding and thrombus formation are constant. There is relative hypothyroidism in smoker group only in summer season

  6. Preliminary results on seasonal changes in flower bud cold hardiness of sour cherry

    DEFF Research Database (Denmark)

    Liu, Guangping; Pagter, Majken; Andersen, Lillie

    2012-01-01

    . cerasus ‘Kelleriis 16’ under natural conditions, and investigated seasonal changes in flower bud cold hardiness of ‘Stevnsbaer Birgitte’. In a cold winter with unusual low temperatures in December, the injury rate of buds of ‘Stevnsbaer Birgitte’ was significantly higher than that of ‘Kelleriis 16......’, confirming that buds of the latter cultivar are considerably more cold hardy than buds of ‘Stevnsbaer Birgitte’. The majority of frost injuries in buds of ‘Stevnsbaer Birgitte’ occurred mid-winter, but dehardening appeared fast, indicating that the critical injury times of buds of ‘Stevnsbaer Birgitte...

  7. [Seasonal changes of fish species composition and diversity in mudflat wetlands of Hangzhou Bay].

    Science.gov (United States)

    Jia, Xing-huan; Zhang, Heng; Jiang, Ke-yi; Wu, Ming

    2010-12-01

    In order to understand the spatiotemporal variation of fish species composition and biodiversity in the mudflat wetlands of Hangzhou Bay, thirty six surveys were conducted in the mudflat area, inning area, and aquaculture area in the south bank of the Bay in. March (early spring), May (spring), July (summer), and October (autumn), 2009. A total of 41 species belonging to 9 orders and 16 families were observed, among which, Cyprinid had the largest species number (14 species, 33.3% of the total), followed by Gobiidae (8 species, 19.1%). According to the lifestyle of fish, these 41 species could be divided into five ecological types, i.e., freshwater type (21 species), brackish-water type (16 species), inshore type (2 species), anadromous type (Coilia ectenes), and catadromios type (Anguilla japonica). The fish abundance was the highest (54. 5 fish per net) in summer, followed by in spring and autumn, and the lowest (17.7 fish per net) in early spring. In the three habitats, mudflat area and inning area had the similar seasonal change of fish abundance, i.e., the lowest in early spring, the highest in summer, and then decreased in autumn. Only two or three species were the dominant species in different seasons. In mudflat area, the dominant species were Mugil cephalus and Liza carinatus; while in inning and aquaculture areas, the dominant species were Carassius auratus, Hemiculter leucisculus, and Pseudorasbora parva. The values of Margalef's richness index (D), Pielou's evenness index (J), and Shannon index (H) were lower in March than in other months, but had no significant differences among May, July, and October (P > 0.05). The H value ranged in 0. 27-2. 13, being the lowest in March and higher in May and October (1.66 and 1.63, respectively). Overall, the fish abundance and biodiversity in the mudflat wetlands of Hangzhou Bay had apparent seasonal changes.

  8. Cultural complexity, post-colonialism and educational change: Challenges for comparative educators

    Science.gov (United States)

    Hickling-Hudson, Anne

    2007-01-01

    This study explores various elements in the struggle for a post-colonial refashioning of cultural identity through education. Drawing on experiences in Australia and the Caribbean, the author illustrates how educational systems undergoing decolonisation reflect socio-cultural tensions of race and power. The author discusses the complexities for comparative educators in engaging with suppressed knowledge, recognising the yearnings of the marginalised, challenging the conditions that lead to poverty, and refashioning education for social justice in an era when the achievement of justice seems increasingly difficult. She argues that comparative educators can benefit from using post-colonial thinking to understand cultural complexity and promote lifeaffirming practices in educational change.

  9. Climate change and landscape development in post-closure safety assessment of solid radioactive waste disposal: Results of an initiative of the IAEA.

    Science.gov (United States)

    Lindborg, T; Thorne, M; Andersson, E; Becker, J; Brandefelt, J; Cabianca, T; Gunia, M; Ikonen, A T K; Johansson, E; Kangasniemi, V; Kautsky, U; Kirchner, G; Klos, R; Kowe, R; Kontula, A; Kupiainen, P; Lahdenperä, A-M; Lord, N S; Lunt, D J; Näslund, J-O; Nordén, M; Norris, S; Pérez-Sánchez, D; Proverbio, A; Riekki, K; Rübel, A; Sweeck, L; Walke, R; Xu, S; Smith, G; Pröhl, G

    2018-03-01

    The International Atomic Energy Agency has coordinated an international project addressing climate change and landscape development in post-closure safety assessments of solid radioactive waste disposal. The work has been supported by results of parallel on-going research that has been published in a variety of reports and peer reviewed journal articles. The project is due to be described in detail in a forthcoming IAEA report. Noting the multi-disciplinary nature of post-closure safety assessments, here, an overview of the work is given to provide researchers in the broader fields of radioecology and radiological safety assessment with a review of the work that has been undertaken. It is hoped that such dissemination will support and promote integrated understanding and coherent treatment of climate change and landscape development within an overall assessment process. The key activities undertaken in the project were: identification of the key processes that drive environmental change (mainly those associated with climate and climate change), and description of how a relevant future may develop on a global scale; development of a methodology for characterising environmental change that is valid on a global scale, showing how modelled global changes in climate can be downscaled to provide information that may be needed for characterising environmental change in site-specific assessments, and illustrating different aspects of the methodology in a number of case studies that show the evolution of site characteristics and the implications for the dose assessment models. Overall, the study has shown that quantitative climate and landscape modelling has now developed to the stage that it can be used to define an envelope of climate and landscape change scenarios at specific sites and under specific greenhouse-gas emissions assumptions that is suitable for use in quantitative post-closure performance assessments. These scenarios are not predictions of the future, but

  10. Quantitative Experiments to Explain the Change of Seasons

    Science.gov (United States)

    Testa, Italo; Busarello, Gianni; Puddu, Emanuella; Leccia, Silvio; Merluzzi, Paola; Colantonio, Arturo; Moretti, Maria Ida; Galano, Silvia; Zappia, Alessandro

    2015-01-01

    The science education literature shows that students have difficulty understanding what causes the seasons. Incorrect explanations are often due to a lack of knowledge about the physical mechanisms underlying this phenomenon. To address this, we present a module in which the students engage in quantitative measurements with a photovoltaic panel to…

  11. Modeling uptake kinetics of cadmium by field-grown lettuce

    Energy Technology Data Exchange (ETDEWEB)

    Chen Weiping [Department of Environmental Sciences, University of California, 900 University Avenue, Riverside, CA 92521 (United States)], E-mail: chenweip@yahoo.com.cn; Li Lianqing [Institute of Resources, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing 210095 (China); Chang, Andrew C.; Wu Laosheng [Department of Environmental Sciences, University of California, 900 University Avenue, Riverside, CA 92521 (United States); Kwon, Soon-Ik [Agricultural Environmental and Ecology Division, National Institute of Agricultural Science and Technology, Suwon 441-707 (Korea, Republic of); Bottoms, Rick [Desert Research and Extension Center, 1004 East Holton Road, El Centro, CA 92243 (United States)

    2008-03-15

    Cadmium uptake by field grown Romaine lettuce treated with P-fertilizers of different Cd levels was investigated over an entire growing season. Results indicated that the rate of Cd uptake at a given time of the season can be satisfactorily described by the Michaelis-Menten kinetics, that is, plant uptake increases as the Cd concentration in soil solution increases, and it gradually approaches a saturation level. However, the rate constant of the Michaelis-Menten kinetics changes over the growing season. Under a given soil Cd level, the cadmium content in plant tissue decreases exponentially with time. To account for the dynamic nature of Cd uptake, a kinetic model integrating the time factor was developed to simulate Cd plant uptake over the growing season: C{sub Plant} = C{sub Solution} . PUF{sub max} . exp[-b . t], where C{sub Plant} and C{sub Solution} refer to the Cd content in plant tissue and soil solution, respectively, PUF{sub max} and b are kinetic constants. - A kinetic model was developed to evaluate the uptake of Cd under field conditions.

  12. Modeling uptake kinetics of cadmium by field-grown lettuce

    International Nuclear Information System (INIS)

    Chen Weiping; Li Lianqing; Chang, Andrew C.; Wu Laosheng; Kwon, Soon-Ik; Bottoms, Rick

    2008-01-01

    Cadmium uptake by field grown Romaine lettuce treated with P-fertilizers of different Cd levels was investigated over an entire growing season. Results indicated that the rate of Cd uptake at a given time of the season can be satisfactorily described by the Michaelis-Menten kinetics, that is, plant uptake increases as the Cd concentration in soil solution increases, and it gradually approaches a saturation level. However, the rate constant of the Michaelis-Menten kinetics changes over the growing season. Under a given soil Cd level, the cadmium content in plant tissue decreases exponentially with time. To account for the dynamic nature of Cd uptake, a kinetic model integrating the time factor was developed to simulate Cd plant uptake over the growing season: C Plant = C Solution . PUF max . exp[-b . t], where C Plant and C Solution refer to the Cd content in plant tissue and soil solution, respectively, PUF max and b are kinetic constants. - A kinetic model was developed to evaluate the uptake of Cd under field conditions

  13. Evapotranspiration and water balance in a hot pepper (Capsicum frutescens L.) field during a dry season in the tropics

    Science.gov (United States)

    Laban, S.; Oue, H.; Rampisela, D. A.

    2018-05-01

    Evapotranspiration and water balance in a hot pepper (Capsicum frutescens L.) field during the 2nd dry season were analyzed in this study. Actual evapotranspiration (ET) was estimated by Bowen Ratio Energy Budget (BREB) method, potential evaporation (EP) was calculated by Penman method, and irrigation volume of water was measured manually. Meteorological instruments were installed in the experimental field during hot pepper cultivation. Leaf area index increased during the growing stages where the highest LAI of 1.65 in the generative stage. The daily average of ET was 1.94 and EP was 6.71 mm resulting in low Kc. The Kc values were significantly different between stage to stage under T-test analysis (α = 0.05). Moreover, Kc in every stage could be related to soil water content (SWC) in logarithmic function. Totally, ET during hot pepper cultivation was 179.19 mm, while rainfall was 180.0 mm and irrigation water was 27.42 mm. However, there was a water shortages during vegetative and generative stages. This study suggested that consumptive water of hot pepper was complimented by soil and groundwater under the condition of water shortages in the vegetative and generative stages during the 2nd dry season.

  14. Seasonal Variation in Human Salivary Cortisol Concentration

    DEFF Research Database (Denmark)

    Persson, Roger; Garde, Anne Helene; Hansen, Åse Marie

    2008-01-01

    Measurement of cortisol concentration can contribute important information about an individual's ability to adjust to various environmental demands of both physical and psychosocial origin. However, one uncertainty that affects the possibilities of correctly interpreting and designing field studies...... is the lack of observations of the impact of seasonal changes on cortisol excretion. For this reason, the month-to-month changes in diurnal cortisol concentration, the awakening cortisol response (ACR), maximum morning concentration, and fall during the day were studied in a group of 24 healthy men and women...... 32 to 61 yrs of age engaged in active work. On one workday for 12 consecutive months, participants collected saliva at four time points for determination of cortisol: at awakening, +30 min, +8 h, and at 21:00 h. Data were analyzed by a repeated measures design with month (12 levels) and time...

  15. Effect of temperature on Acoustic Evaluation of standing trees and logs: Part 2: Field Investigation

    Science.gov (United States)

    Shan Gao; Xiping Wang; Lihai Wang; R. Bruce Allison

    2013-01-01

    The objectives of this study were to investigate the effect of seasonal temperature changes on acoustic velocity measured on standing trees and green logs and to develop models for compensating temperature differences because acoustic measurements are performed in different climates and seasons. Field testing was conducted on 20 red pine (Pinus resinosa...

  16. Seasonal shift in climatic limiting factors on tree transpiration: evidence from sap flow observations at alpine treelines in southeast Tibet

    Directory of Open Access Journals (Sweden)

    Liu Xinsheng

    2016-07-01

    Full Text Available Alpine and northern treelines are primarily controlled by low temperatures. However, little is known about the impact of low soil temperature on tree transpiration at treelines. We aim to test the hypothesis that in cold-limited forests, the main limiting factors for tree transpiration switch from low soil temperature before summer solstice to atmospheric evaporative demand after summer solstice, which generally results in low transpiration in the early growing season. Sap flow, meteorological factors and predawn needle water potential were continuously monitored throughout one growing season across Smith fir (Abies georgei var. smithii and juniper (Juniperus saltuaria treelines in southeast Tibet. Sap flow started in early May and corresponded to a threshold mean air-temperature of 0 oC. Across tree species, transpiration was mainly limited by low soil temperature prior to the summer solstice but by vapor pressure deficit and solar radiation post-summer solstice, which was further confirmed on a daily scale. As a result, tree transpiration for both tree species was significantly reduced in the pre-summer solstice period as compared to post-summer solstice, resulting in a lower predawn needle water potential for Smith fir trees in the early growing season. Our data supported the hypothesis, suggesting that tree transpiration mainly responds to soil temperature variations in the early growing season. The results are important for understanding the hydrological response of cold-limited forest ecosystems to climate change.

  17. Nonbreeding-Season Drivers of Population Dynamics in Seasonal Migrants: Conservation Parallels Across Taxa

    Directory of Open Access Journals (Sweden)

    Anna M. Calvert

    2009-12-01

    Full Text Available For seasonal migrants, logistical constraints have often limited conservation efforts to improving survival and reproduction during the breeding season only. Yet, mounting empirical evidence suggests that events occurring throughout the migratory life cycle can critically alter the demography of many migrant species. Herein, we build upon recent syntheses of avian migration research to review the role of non-breeding seasons in determining the population dynamics and fitness of diverse migratory taxa, including salmonid fishes, marine mammals, ungulates, sea turtles, butterflies, and numerous bird groups. We discuss several similarities across these varied migrants: (i non-breeding survivorship tends to be a strong driver of population growth; (ii non-breeding events can affect fitness in subsequent seasons through seasonal interactions at individual- and population-levels; (iii broad-scale climatic influences often alter non-breeding resources and migration timing, and may amplify population impacts through covariation among seasonal vital rates; and (iv changes to both stationary and migratory non-breeding habitats can have important consequences for abundance and population trends. Finally, we draw on these patterns to recommend that future conservation research for seasonal migrants will benefit from: (1 more explicit recognition of the important parallels among taxonomically diverse migratory animals; (2 an expanded research perspective focused on quantification of all seasonal vital rates and their interactions; and (3 the development of detailed population projection models that account for complexity and uncertainty in migrant population dynamics.

  18. Changing seasonality patterns in Central Europe from Miocene Climate Optimum to Miocene Climate Transition deduced from the Crassostrea isotope archive

    Science.gov (United States)

    Harzhauser, Mathias; Piller, Werner E.; Müllegger, Stefan; Grunert, Patrick; Micheels, Arne

    2011-03-01

    The Western Tethyan estuarine oyster Crassostrea gryphoides is an excellent climate archive due to its large size and rapid growth. It is geologically long lived and allows a stable isotope-based insight into climatic trends during the Miocene. Herein we utilised the climate archive of 5 oyster shells from the Miocene Climate Optimum (MCO) and the subsequent Miocene Climate Transition (MCT) to evaluate changes of seasonality patterns. MCO shells exhibit highly regular seasonal rhythms of warm-wet and dry-cool seasons. Optimal conditions resulted in extraordinary growth rates of the oysters. δ 13C profiles are in phase with δ 18O although phytoplankton blooms may cause a slight offset. Estuarine waters during the MCO in Central Europe display a seasonal temperature range of c. 9-10 °C. Absolute water temperatures have ranged from 17 to 19 °C during cool seasons and up to 28 °C in warm seasons. Already during the early phase of the MCO, the growth rates are distinctly declining, although gigantic and extremely old shells have been formed at that time. Still, a very regular and well expressed seasonality is dominating the isotope profiles, but episodically occurring extreme climate events influence the environments. The seasonal temperature range is still c. 9 °C but the cool season temperature seems to be slightly lower (16 °C) and the warm season water temperature does not exceed c. 25 °C. In the later MCT at c. 12.5-12.0 Ma the seasonality pattern is breaking down and is replaced by successions of dry years with irregular precipitation events. No correlation between δ 18O and δ 13C is documented maybe due to a suboptimal nutrition level which would explain the low growth rates and small sizes. The amplitude of seasonal temperature range is decreasing to 5-8 °C. No clear cooling trend can be postulated for that time as the winter season water temperatures range from 15 to 20 °C. This may point to unstable precipitation rhythms on a multi-annual to

  19. Palaeomagnetic dating method accounting for post-depositional remanence and its application to geomagnetic field modelling

    Science.gov (United States)

    Nilsson, A.; Suttie, N.

    2016-12-01

    Sedimentary palaeomagnetic data may exhibit some degree of smoothing of the recorded field due to the gradual processes by which the magnetic signal is `locked-in' over time. Here we present a new Bayesian method to construct age-depth models based on palaeomagnetic data, taking into account and correcting for potential lock-in delay. The age-depth model is built on the widely used "Bacon" dating software by Blaauw and Christen (2011, Bayesian Analysis 6, 457-474) and is designed to combine both radiocarbon and palaeomagnetic measurements. To our knowledge, this is the first palaeomagnetic dating method that addresses the potential problems related post-depositional remanent magnetisation acquisition in age-depth modelling. Age-depth models, including site specific lock-in depth and lock-in filter function, produced with this method are shown to be consistent with independent results based on radiocarbon wiggle match dated sediment sections. Besides its primary use as a dating tool, our new method can also be used specifically to identify the most likely lock-in parameters for a specific record. We explore the potential to use these results to construct high-resolution geomagnetic field models based on sedimentary palaeomagnetic data, adjusting for smoothing induced by post-depositional remanent magnetisation acquisition. Potentially, this technique could enable reconstructions of Holocene geomagnetic field with the same amplitude of variability observed in archaeomagnetic field models for the past three millennia.

  20. Factors associated with post-seasonal serological titer and risk factors for infection with the pandemic A/H1N1 virus in the French general population.

    Directory of Open Access Journals (Sweden)

    Nathanael Lapidus

    Full Text Available The CoPanFlu-France cohort of households was set up in 2009 to study the risk factors for infection by the pandemic influenza virus (H1N1pdm in the French general population. The authors developed an integrative data-driven approach to identify individual, collective and environmental factors associated with the post-seasonal serological H1N1pdm geometric mean titer, and derived a nested case-control analysis to identify risk factors for infection during the first season. This analysis included 1377 subjects (601 households. The GMT for the general population was 47.1 (95% confidence interval (CI: 45.1, 49.2. According to a multivariable analysis, pandemic vaccination, seasonal vaccination in 2009, recent history of influenza-like illness, asthma, chronic obstructive pulmonary disease, social contacts at school and use of public transports by the local population were associated with a higher GMT, whereas history of smoking was associated with a lower GMT. Additionally, young age at inclusion and risk perception of exposure to the virus at work were identified as possible risk factors, whereas presence of an air humidifier in the living room was a possible protective factor. These findings will be interpreted in light of the longitudinal analyses of this ongoing cohort.

  1. Post-glacial faulting in the Lansjaerv area, Northern Sweden. Comments from the expert group on a field visit at the Molberget post-glacial fault area, 1991

    International Nuclear Information System (INIS)

    Stanfors, R.; Ericsson, L.O.

    1993-05-01

    Post-glacial faults have been recognized in the northern Baltic shield for several decades. It is important to evaluate whether such neotectonic movements can lead to new fracturing or decisively alter the geohydrological or geohydrochemical situation around a final repository for spent nuclear fuel. The post-glacial Lansjaerv fault was chosen for an interdisciplinary study because of its relative accessibility. The goals of the study were to assess the mechanisms that caused present day scraps, to clarify the extent of any recent fracturing and to clarify the extent of any ongoing movements. All these objectives were reasonably met through a series of studies, which have been performed by SKB during 1986-1992 in two phases. This report gives a summary of the first phase of the Lansjaerv study (1986-1989) and describes achievements that have been gained during the second phase of the study. As a final of the field-work in the Lansjaerv area a meeting combined with a field excursion was arranged by SKB in June 1991 for a group of international experts. Comments from the expert group on the excursion and the overall Lansjaerv project are presented. One of the major conclusions is that the Lansjaerv post-glacial fault reactivated pre-existing old structures and that the causes of the post-glacial movements is a combination of plate tectonics and deglaciation

  2. Microbial and geochemical assessment of bauxitic un-mined and post-mined chronosequence soils from Mocho Mountains, Jamaica.

    Science.gov (United States)

    Lewis, Dawn E; Chauhan, Ashvini; White, John R; Overholt, Will; Green, Stefan J; Jasrotia, Puja; Wafula, Denis; Jagoe, Charles

    2012-10-01

    Microorganisms are very sensitive to environmental change and can be used to gauge anthropogenic impacts and even predict restoration success of degraded environments. Here, we report assessment of bauxite mining activities on soil biogeochemistry and microbial community structure using un-mined and three post-mined sites in Jamaica. The post-mined soils represent a chronosequence, undergoing restoration since 1987, 1997, and 2007. Soils were collected during dry and wet seasons and analyzed for pH, organic matter (OM), total carbon (TC), nitrogen (TN), and phosphorus. The microbial community structure was assessed through quantitative PCR and massively parallel bacterial ribosomal RNA (rRNA) gene sequencing. Edaphic factors and microbial community composition were analyzed using multivariate statistical approaches and revealed a significant, negative impact of mining on soil that persisted even after greater than 20 years of restoration. Seasonal fluctuations contributed to variation in measured soil properties and community composition, but they were minor in comparison to long-term effects of mining. In both seasons, post-mined soils were higher in pH but OM, TC, and TN decreased. Bacterial rRNA gene analyses demonstrated a general decrease in diversity in post-mined soils and up to a 3-log decrease in rRNA gene abundance. Community composition analyses demonstrated that bacteria from the Proteobacteria (α, β, γ, δ), Acidobacteria, and Firmicutes were abundant in all soils. The abundance of Firmicutes was elevated in newer post-mined soils relative to the un-mined soil, and this contrasted a decrease, relative to un-mined soils, in proteobacterial and acidobacterial rRNA gene abundances. Our study indicates long-lasting impacts of mining activities to soil biogeochemical and microbial properties with impending loss in soil productivity.

  3. Seasonal changes in chemical composition and nutritive value of native forages in a spruce-hemlock forest, southeastern Alaska.

    Science.gov (United States)

    Thomas A. Hanley; Jay D. McKendrick

    1983-01-01

    Twenty-two forages from Admiralty Island, southeastern Alaska, were monitored bimonthly for one year to assess seasonal changes in their chemical composition: neutral detergent fiber, acid detergent fiber, cellulose, lignin/cutin, invitro dry-matter digestibility, total nitrogen, phosphorus, potassium, calcium, magnesium, sodium, copper, manganese, iron, and zinc....

  4. SEASONAL ASSESSMENT OF HYDROGRAPHIC VARIABLES AND PHYTOPLANKTON COMMUNITY IN THE ARABIAN SEA WATERS OF KERALA, SOUTHWEST COAST OF INDIA

    Directory of Open Access Journals (Sweden)

    Sushanth Vishwanath Rai

    2014-12-01

    Full Text Available The seasonal variation of the hydrographic variables and phytoplankton species in the Arabian Sea waters of the Kerala coast, Southern India was investigated during different seasons. The variables such as pH, temperature, salinity, turbidity and chlorophyll-a contents of water were found to be high during pre-monsoon season and the dissolved oxygen content was minimal. The concentration of nutrients viz., nitrate, phosphate, silicate varied independently. In the study a total of 53 species of phytoplankton were recorded. Their density was higher during the post-monsoon season than during other seasons and the diatoms were found to be the dominant species. The major phytoplankton in terms of frequency and abundance were the species namely, Biddulphia mobiliensis, Chaetoceros curvisetus, Licmophora abbreviata, Skeletonema costatum, Prorocentrum micans and Oscillatoria sp. They showed significant positive correlation with pH, temperature, salinity, nitrate, phosphate and chlorophyll-a contents, whereas turbidity, dissolved oxygen and silicate exhibited significant negative correlation. The Principal Component Analysis (PCA developed two principal components with 84.74% of total variability in the water quality which separated pre- and post-monsoon periods from the monsoon season on axis I, and pre-monsoon and monsoon periods from post-monsoon on axis II.

  5. Habitat and distribution of post-recruit life stages of the squid Loligo forbesii

    Science.gov (United States)

    Smith, Jennifer M.; Macleod, Colin D.; Valavanis, Vasilis; Hastie, Lee; Valinassab, Tooraj; Bailey, Nick; Santos, M. Begoña; Pierce, Graham J.

    2013-10-01

    This study models habitat preferences of the squid Loligo forbesii through its post-recruitment life cycle in waters around Scotland (UK). Trawl survey and market sample data from 1985 to 2004 are used to model seasonal habitats of immature, maturing and mature squid (maturity being inferred from size and season). Squid presence-absence and catch rate in areas of presence were analysed using generalised additive models, relating spatiotemporal patterns of distribution and abundance to ecogeographic variables. For all maturity classes, higher abundance in winter and spring (i.e., quarters 1 and 2) was associated with deeper water while higher abundance in summer and autumn (quarters 3 and 4) was associated with shallower water, consistent with seasonal onshore-offshore migrations but suggesting that most spawning may take place in deeper waters. The preferred SST range was generally 8-8.75 °C while preferred salinity values were below 35‰ in winter and summer and above 35‰ in spring and autumn. Squid were positively associated with gravel substrate and negatively associated with mud. Seasonal changes in habitat use were more clearly evident than changes related to inferred maturity, although the two effects cannot be fully separated due to the annual life cycle. Habitat selection for this species can be satisfactorily modelled on a seasonal basis; predictions based on such models could be useful for fishers to target the species more effectively, and could assist managers wishing to protect spawning grounds. The extent to which this approach may be useful for other cephalopods is discussed.

  6. Seasonal variation of semidiurnal internal tides in the East/Japan Sea

    Science.gov (United States)

    Jeon, Chanhyung; Park, Jae-Hun; Varlamov, Sergey M.; Yoon, Jong-Hwan; Kim, Young Ho; Seo, Seongbong; Park, Young-Gyu; Min, Hong Sik; Lee, Jae Hak; Kim, Cheol-Ho

    2014-05-01

    The seasonal variation of semidiurnal internal tides in the East/Japan Sea was investigated using 25 month long output from a real-time ocean forecasting system. The z coordinate eddy-resolving high-resolution numerical model, called the RIAM ocean model, incorporates data assimilation that nudges temperature and salinity fields together with volume transport through the Korea Strait to produce realistic oceanic currents and stratification. In addition to atmospheric forcing, it includes tidal forcing of 16 major components along open boundaries. The model generates energetic semidiurnal internal tides around the northern entrance of the Korea Strait. Energy conversion from barotropic to baroclinic (internal) tides varies seasonally with maxima in September (ranging 0.48-0.52 GW) and minima in March (ranging 0.11-0.16 GW). This seasonal variation is induced by the seasonality in stratification near the southwestern East/Japan Sea. The propagation distance of the internal tides is associated with generation intensity and wavelength. From late summer to early winter, the semidiurnal internal tides travel relatively far from the generation region due to stratification changes; its energy dissipates less as a result of longer wavelengths. Our results suggest that spatiotemporal variation of internal-tide-induced mixing due to the seasonality in the generation, propagation, and dissipation of internal tides should be considered for a more realistic simulation of water masses and circulation in models of the East/Japan Sea.

  7. Monitoring Seasonal Changes in Winery-Resident Microbiota.

    Science.gov (United States)

    Bokulich, Nicholas A; Ohta, Moe; Richardson, Paul M; Mills, David A

    2013-01-01

    During the transformation of grapes to wine, wine fermentations are exposed to a large area of specialized equipment surfaces within wineries, which may serve as important reservoirs for two-way transfer of microbes between fermentations. However, the role of winery environments in shaping the microbiota of wine fermentations and vectoring wine spoilage organisms is poorly understood at the systems level. Microbial communities inhabiting all major equipment and surfaces in a pilot-scale winery were surveyed over the course of a single harvest to track the appearance of equipment microbiota before, during, and after grape harvest. Results demonstrate that under normal cleaning conditions winery surfaces harbor seasonally fluctuating populations of bacteria and fungi. Surface microbial communities were dependent on the production context at each site, shaped by technological practices, processing stage, and season. During harvest, grape- and fermentation-associated organisms populated most winery surfaces, acting as potential reservoirs for microbial transfer between fermentations. These surfaces harbored large populations of Saccharomyces cerevisiae and other yeasts prior to harvest, potentially serving as an important vector of these yeasts in wine fermentations. However, the majority of the surface communities before and after harvest comprised organisms with no known link to wine fermentations and a near-absence of spoilage-related organisms, suggesting that winery surfaces do not overtly vector wine spoilage microbes under normal operating conditions.

  8. Monitoring Seasonal Changes in Winery-Resident Microbiota.

    Directory of Open Access Journals (Sweden)

    Nicholas A Bokulich

    Full Text Available During the transformation of grapes to wine, wine fermentations are exposed to a large area of specialized equipment surfaces within wineries, which may serve as important reservoirs for two-way transfer of microbes between fermentations. However, the role of winery environments in shaping the microbiota of wine fermentations and vectoring wine spoilage organisms is poorly understood at the systems level. Microbial communities inhabiting all major equipment and surfaces in a pilot-scale winery were surveyed over the course of a single harvest to track the appearance of equipment microbiota before, during, and after grape harvest. Results demonstrate that under normal cleaning conditions winery surfaces harbor seasonally fluctuating populations of bacteria and fungi. Surface microbial communities were dependent on the production context at each site, shaped by technological practices, processing stage, and season. During harvest, grape- and fermentation-associated organisms populated most winery surfaces, acting as potential reservoirs for microbial transfer between fermentations. These surfaces harbored large populations of Saccharomyces cerevisiae and other yeasts prior to harvest, potentially serving as an important vector of these yeasts in wine fermentations. However, the majority of the surface communities before and after harvest comprised organisms with no known link to wine fermentations and a near-absence of spoilage-related organisms, suggesting that winery surfaces do not overtly vector wine spoilage microbes under normal operating conditions.

  9. Modeling Aspect Controlled Formation of Seasonally Frozen Ground on Montane Hillslopes: a Case Study from Gordon Gulch, Colorado

    Science.gov (United States)

    Rush, M.; Rajaram, H.; Anderson, R. S.; Anderson, S. P.

    2017-12-01

    The Intergovernmental Panel on Climate Change (2013) warns that high-elevation ecosystems are extremely vulnerable to climate change due to short growing seasons, thin soils, sparse vegetation, melting glaciers, and thawing permafrost. Many permafrost-free regions experience seasonally frozen ground. The spatial distribution of frozen soil exerts a strong control on subsurface flow and transport processes by reducing soil permeability and impeding infiltration. Accordingly, evolution of the extent and duration of frozen ground may alter streamflow seasonality, groundwater flow paths, and subsurface storage, presenting a need for coupled thermal-hydrologic models to project hydrologic responses to climate warming in high-elevation regions. To be useful as predictive tools, such models should incorporate the heterogeneity of solar insolation, vegetation, and snowpack dynamics. We present a coupled thermal-hydrologic modeling study against the backdrop of field observations from Gordon Gulch, a seasonally snow-covered montane catchment in the Colorado Front Range in the Boulder Creek Critical Zone Observatory. The field site features two instrumented hillslopes with opposing aspects: the snowpack on the north-facing slope persists throughout much of the winter season, while the snowpack on the south-facing slope is highly ephemeral. We implemented a surface energy balance and snowpack accumulation and ablation model that is coupled to the subsurface flow and transport code PFLOTRAN-ICE to predict the hydrologic consequences of aspect-controlled frozen soil formation during water years 2013-2016. Preliminary model results demonstrate the occurrence of seasonally-frozen ground on the north-facing slope that directs snowmelt to the stream by way of shallow subsurface flow paths. The absence of persistently frozen ground on the south-facing slope allows deeper infiltration of snowmelt recharge. The differences in subsurface flow paths also suggest strong aspect

  10. Season, molt, and body size influence mercury concentrations in grebes

    Science.gov (United States)

    Hartman, Christopher; Ackerman, Joshua T.; Herzog, Mark; Eagles-Smith, Collin A.

    2017-01-01

    We studied seasonal and physiological influences on mercury concentrations in western grebes (Aechmophorus occidentalis) and Clark's grebes (A. occidentalis) across 29 lakes and reservoirs in California, USA. Additionally, at three of these lakes, we conducted a time series study, in which we repeatedly sampled grebe blood mercury concentrations during the spring, summer, and early fall. Grebe blood mercury concentrations were higher among males (0.61 ± 0.12 μg/g ww) than females (0.52 ± 0.10 μg/g ww), higher among Clark's grebes (0.58 ± 0.12 μg/g ww) than western grebes (0.51 ± 0.10 μg/g ww), and exhibited a strong seasonal pattern (decreasing by 60% from spring to fall). Grebe blood THg concentrations exhibited a shallow, inverse U-shaped pattern with body size, and was lowest among the smallest and largest grebes. Further, the relationship between grebe blood mercury concentrations and wing primary feather molt exhibited a shallow U-shaped pattern, where mercury concentrations were highest among birds that had not yet begun molting, decreased approximately 24% between pre-molt and late molt, and increased approximately 19% from late molt to post-molt. Because grebes did not begin molting until mid-summer, lower grebe blood mercury concentrations observed in late summer and early fall were consistent with the onset of primary feather molt. However, because sampling date was a much stronger predictor of grebe mercury concentrations than molt, other seasonally changing environmental factors likely played a larger role than molt in the seasonal variation in grebe mercury concentrations. In the time series study, we found that seasonal trends in grebe mercury concentrations were not consistent among lakes, indicating that lake-specific variation in mercury dynamics influence the overall seasonal decline in grebe blood mercury concentrations. These results highlight the importance of accounting for sampling date, as well as ecological processes that may

  11. Influence of the season in the development of symptoms in plants of ‘Grande naine’ artificially inoculated with Mycosphaerella fijiensis in greenhouse

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    Michel Leiva-Mora

    2011-01-01

    Full Text Available Plant pathogen fungi required favorable conditions to invade and colonize plant tissues, which may change according to the season of the year. This work is aimed to evaluate the influence of different seasons (June-August and August-October in the development of symptoms in ‘Grande naine’ artificially inoculated with Mycosphaerella fijiensis in greenhouse. Inoculation assays were done during three consecutive years (2005, 2006 and 2007. None differences in attack intensity between different seasons were observed, at 14, 21, 35, 49 y 63 days post inoculation (dpi. This shows that the development of symptoms in greenhouse was similar in the period from June to October. Temperature and humidity have not been controlled by all laboratories that conduct studies related to M. fijiensis. Then, to choose the appropriate season for artificial inoculations is a prerequisite for effective development of M. fijiensis infective cycle and to avoid masking in the phenotype of resistance. Key words: attack intensity, Black Sigatoka, mycelia

  12. Real-time monitoring of smallholder farmer responses to intra-seasonal climate variability in central Kenya

    Science.gov (United States)

    Krell, N.; Evans, T. P.; Estes, L. D.; Caylor, K. K.

    2017-12-01

    While international metrics of food security and water availability are generated as spatial averages at the regional to national levels, climate variability impacts are differentially felt at the household level. This project investigated scales of variability of climate impacts on smallholder farmers using social and environmental data in central Kenya. Using sub-daily real-time environmental measurements to monitor smallholder agriculture, we investigated how changes in seasonal precipitation affected food security around Laikipia county from September 2015 to present. We also conducted SMS-based surveys of over 700 farmers to understand farmers' decision-making within the growing season. Our results highlight field-scale heterogeneity in biophysical and social factors governing crop yields using locally sensed real-time environmental data and weekly farmer-reported information about planting, harvesting, irrigation, and crop yields. Our preliminary results show relationships between changes in seasonal precipitation, NDVI, and soil moisture related to crop yields and decision-making at several scales. These datasets present a unique opportunity to collect highly spatially and temporally resolved information from data-poor regions at the household level.

  13. Influence of climate change on flood magnitude and seasonality in the Arga River catchment in Spain

    Science.gov (United States)

    Garijo, Carlos; Mediero, Luis

    2018-04-01

    Climate change projections suggest that extremes, such as floods, will modify their behaviour in the future. Detailed catchment-scale studies are needed to implement the European Union Floods Directive and give recommendations for flood management and design of hydraulic infrastructure. In this study, a methodology to quantify changes in future flood magnitude and seasonality due to climate change at a catchment scale is proposed. Projections of 24 global climate models are used, with 10 being downscaled by the Spanish Meteorological Agency (Agencia Estatal de Meteorología, AEMET) and 14 from the EURO-CORDEX project, under two representative concentration pathways (RCPs) 4.5 and 8.5, from the Fifth Assessment Report provided by the Intergovernmental Panel on Climate Change. Downscaled climate models provided by the AEMET were corrected in terms of bias. The HBV rainfall-runoff model was selected to simulate the catchment hydrological behaviour. Simulations were analysed through both annual maximum and peaks-over-threshold (POT) series. The results show a decrease in the magnitude of extreme floods for the climate model projections downscaled by the AEMET. However, results for the climate model projections downscaled by EURO-CORDEX show differing trends, depending on the RCP. A small decrease in the flood magnitude was noticed for the RCP 4.5, while an increase was found for the RCP 8.5. Regarding the monthly seasonality analysis performed by using the POT series, a delay in the flood timing from late-autumn to late-winter is identified supporting the findings of recent studies performed with observed data in recent decades.

  14. Seasonal soybean crop reflectance

    Science.gov (United States)

    Lemaster, E. W. (Principal Investigator); Chance, J. E.

    1983-01-01

    Data are presented from field measurements of 1980 including 5 acquisitions of handheld radiometer reflectance measurements, 7 complete sets of parameters for implementing the Suits mode, and other biophysical parameters to characterize the soybean canopy. LANDSAT calculations on the simulated Brazilian soybean reflectance are included along with data collected during the summer and fall on 1981 on soybean single leaf optical parameters for three irrigation treatments. Tests of the Suits vegetative canopy reflectance model for the full hemisphere of observer directions as well as the nadir direction show moderate agreement for the visible channels of the MSS and poor agreement in the near infrared channel. Temporal changes in the spectral characteristics of the single leaves were seen to occur as a function of maturity which demonstrates that the absorptance of a soybean single leaf is more a function of thetransmittancee characteristics than the seasonally consistent single leaf reflectance.

  15. Enhanced Strength and Sprint Levels, and Changes in Blood Parameters during a Complete Athletics Season in 800 m High-Level Athletes

    Directory of Open Access Journals (Sweden)

    Beatriz Bachero-Mena

    2017-08-01

    Full Text Available The purpose of this study was to analyze changes in sprint, strength, hematological, and hormonal parameters in high-level 800 m athletes during a complete athletics season. Thirteen male athletes of national and international level in 800 m (personal best ranging from 1:43 to 1:58 min:ss participated in this study. A total of 5 tests were conducted during a complete athletics season. Athletes performed sprint tests (20 and 200 m, countermovement jump (CMJ, jump squat (JS, and full squat (SQ tests. Blood samples (red and white blood profile and hormones were collected in test 1 (T1, test 3 (T3, and test 5 (T5. A general increase in the performance of the strength and sprint parameters analyzed (CMJ, JS, SQ, 20 m, and 200 m during the season was observed, with a significant time effect in CMJ (P < 0.01, SQ (P < 0.01, and 200 m (P < 0.05. This improvement was accompanied by a significant enhancement of the 800 m performance from T3 to T5 (P < 0.01. Significant changes in some hematological variables: hematocrit (Hct (P < 0.01, mean corpuscular volume (MCV (P < 0.001, mean corpuscular hemoglobin content (MCHC (P < 0.001, white blood cells count (WBC (P < 0.05, neutrophils (P < 0.05, monocytes (P < 0.05, and mean platelet volume (MPV (P < 0.05 were observed throughout the season. The hormonal response and creatin kinase (CK did not show significant variations during the season, except for insulin-like growth factor I (IGF-1 (P < 0.05. In conclusion, our results suggest the importance of strength levels in middle-distance athletes. On the other hand, variations in some hematological parameters and a depression of the immune system occurred during the season. Therefore, monitoring of the mechanical, hematological and hormonal response in athletes may help coaches and athletes to optimize the regulation of training contents and may be useful to diagnose states of overreaching or overtraining in athletes throughout the season.

  16. Seasonal malaria attack rates in infants and young children in northern Ghana.

    Science.gov (United States)

    Baird, J Kevin; Owusu Agyei, S; Utz, Gregory C; Koram, Kwadwo; Barcus, Mazie J; Jones, Trevor R; Fryauff, David J; Binka, Fred N; Hoffman, Stephen L; Nkrumah, Francis N

    2002-03-01

    The incidence density of infection and disease caused by Plasmodium falciparum in children aged six to 24 months living in the holoendemic Sahel of northern Ghana was measured during the wet and dry seasons of 1996 and 1997. At the beginning of each season, a cohort composed of 259 and 277 randomly selected children received supervised curative therapy with quinine and Fansidar and primaquine for those with normal glucose-6-phosphate dehydrogenase activity. The 20 weeks of post-therapy follow-up consisted of three home visits weekly and examination of Giemsa-stained blood films once every two weeks. Blood films were also taken from children brought to clinic with illness. The incidence density of parasitemia after radical cure was 4.7 infections/person-year during the dry season and 7.1 during the wet season (relative risk = 1.51, 95% confidence interval [CI] = 1.25-1.81; P = 0.00001). Although the mean parasitemia count at time of reinfection in the dry season (3,310/microl) roughly equaled that in the wet season (3,056/microl; P = 0.737), the risk ratio for parasitemia > 20,000/microl during the wet season was 1.71 (95% CI = 1.2-2.4; P = 0.0025). The risk ratio for parasitemia > 20,000/microl with fever during the wet season was 2.45 (95% CI = 1.5-4.1; P = 0.0002). The risk ratio for anemia (hemoglobin < 8 g/dl) at first post-radical cure parasitemia showed no difference between seasons (1.0; 95% CI = 0.73-1.4; P = 0.9915). We did not see seasonal differences in anemia known to exist in this region, probably because the longitudinal cohort design using first parasitemia as an end point prevented the subjects from developing the repeated or chronic infections required for anemia induction. These findings bear upon the design of malaria drug and vaccine trials in holoendemic areas.

  17. Seasonal variation in child mortality in rural Guinea-Bissau.

    Science.gov (United States)

    Nielsen, Bibi Uhre; Byberg, Stine; Aaby, Peter; Rodrigues, Amabelia; Benn, Christine Stabell; Fisker, Ane Baerent

    2017-07-01

    In many African countries, child mortality is higher in the rainy season than in the dry season. We investigated the effect of season on child mortality by time periods, sex and age in rural Guinea-Bissau. Bandim health project follows children under-five in a health and demographic surveillance system in rural Guinea-Bissau. We compared the mortality in the rainy season (June to November) between 1990 and 2013 with the mortality in the dry season (December to May) in Cox proportional hazards models providing rainy vs. dry season mortality rate ratios (r/d-mrr). Seasonal effects were estimated in strata defined by time periods with different frequency of vaccination campaigns, sex and age (<1 month, 1-11 months, 12-59 months). Verbal autopsies were interpreted using InterVa-4 software. From 1990 to 2013, overall mortality was declined by almost two-thirds among 81 292 children (10 588 deaths). Mortality was 51% (95% ci: 45-58%) higher in the rainy season than in the dry season throughout the study period. The seasonal difference increased significantly with age, the r/d-mrr being 0.94 (0.86-1.03) among neonates, 1.57 (1.46-1.69) in post-neonatal infants and 1.83 (1.72-1.95) in under-five children (P for same effect <0.001). According to the InterVa, malaria deaths were the main reason for the seasonal mortality difference, causing 50% of all deaths in the rainy season, but only if the InterVa included season of death, making the argument self-confirmatory. The mortality declined throughout the study, yet rainy season continued to be associated with 51% higher overall mortality. © 2017 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

  18. Seasonal variation in physicochemical properties of coastal waters of Kalpakkam, east coast of India with special emphasis on nutrients.

    Science.gov (United States)

    Satpathy, K K; Mohanty, A K; Natesan, U; Prasad, M V R; Sarkar, S K

    2010-05-01

    A study pertaining to the seasonal variation in physicochemical properties of the coastal waters was carried out at Kalpakkam coast for a period of 1 year (February 2006 to January 2007). It revealed that the coastal water was significantly influenced by freshwater input during North East (NE) monsoon and post-monsoon periods. Concentration of all the nutrients and dissolved oxygen (DO) was relatively high during the NE monsoon, whereas, salinity and chlorophyll-a (chl-a) were at their minimum level during this period. Phytoplankton production peak was observed in summer during which a typical marine condition prevailed. The present observed values of nitrate, phosphate, silicate, and turbidity are significantly high (five to ten times) compared to that of the pre-Tsunami period from this coast. Relatively low DO and chl-a concentration was noticed during the post-Tsunami period. A notable feature of this study is that though nutrient concentration in the coastal waters during post-Tsunami period has increased significantly, turbidity, the most single dominating factor, was found to adversely affect the phytoplankton production during post-Tsunami period as reflected by relatively low chl-a concentration. Thus, the post-Tsunami period may result in a change in coastal biodiversity pattern concomitant with change in coastal water quality.

  19. Quantifying Fire Impact on Alaskan Tundra from Satellite Observations and Field Measurements

    Science.gov (United States)

    Loboda, T. V.; Chen, D.; He, J.; Jenkins, L. K.

    2017-12-01

    Wildfire is a major disturbance agent in Alaskan tundra. The frequency and extent of fire events obtained from paleo, management, and satellite records may yet underestimate the scope of tundra fire impact. Field measurements, collected within the NASA's ABoVE campaign, revealed unexpectedly shallow organic soils ( 15 cm) across all sampled sites of the Noatak valley with no significant difference between recently burned and unburned sites. In typical small and medium-sized tundra burns vegetation recovers rapidly and scars are not discernable in 30 m optical satellite imagery by the end of the first post-fire season. However, field observations indicate that vegetation and subsurface characteristics within fire scars of different ages vary across the landscape. In this study we develop linkages between fire-induced changes to tundra and satellite-based observations from optical, thermal, and microwave imagers to enable extrapolation of in-situ observations to cover the full extent of Alaskan tundra. Our results show that recent ( 30 years) fire history can be reconstructed from optical observations (R2 0.65, pfire history can be determined for 4 years post fire primarily due to increased soil moisture at burned sites. Field measurements suggest that the relatively quick SAR signal dissipation results from more even distribution of surface moisture through the soil column with increases in Active Layer Thickness (ALT). Similar to previous long-term field studies we find an increase in shrub fraction and shrub height within burns over time at the landscape scale; however, the strength and significance of the relationship between shrub fraction and time since fire is governed by burn severity with more severe burns predictably (p post-fire shrub cover. Although reasonably well-correlated to each other when adjusted for topography (R2 0.35, p < 0.001), neither ALT nor soil temperature can be directly linked to optical or thermal brightness observations with acceptable

  20. Proof of the Post-drought Effect of Amazonian Forests from Space

    Science.gov (United States)

    Yang, Y.; Saatchi, S. S.; Xu, L.; Yu, Y.; Myneni, R. B.; Knyazikhin, Y.; CHOI, S.

    2015-12-01

    In 2005, the tropical forests in Amazonia went through a severe drought event across the entire basin. There have been conflict reports on the drought impact on vegetation and the issue was never settled due to limited ground truth. Remote sensing data have been used but often questioned for signal saturation, data quality, or atmosphere contamination. The quantification of carbon changes in this vast terrestrial carbon pool, especially the post-drought effect, is difficult but essential. Lidar measurements, which are regarded as the accurate retrieval of canopy vertical structure, give us the opportunity to quantify the carbon changes for this severe event. Here, we use the lidar waveforms measured from the GLAS sensor from 2004 to 2007 to calculate the vertical profiles of Amazonian forests and their associated carbon stock. After careful quality-filtering, removal of seasonal effect, as well as uncertainty reduction through spatial averaging and random sampling, we find that the mean canopy height in Amazon has much higher reduction from 2006 to 2007 compared to either the drought year from 2004 to 2005, or the immediate post-drought change from 2005 to 2006, demonstrating a lagged effect of drought. Our estimation of carbon loss from model calculation also show that 2005 drought had an significant impact on the carbon exchange, and emissions from post drought disturbance may match the emissions of annual deforestation from Amazonia.