WorldWideScience

Sample records for growing season progress

  1. Monitoring seasonal progress of rice stubble burning in major rice growing districts of Haryana, India, using multidate AWiFS data

    Science.gov (United States)

    Yadav, M.; Prawasi, R.; Jangra, S.; Rana, P.; Kumari, K.; Lal, S.; Jakhar, K.; Sharma, S.; Hooda, R. S.

    2014-11-01

    The present paper describes the methodology and results of assessment of seasonal progress of rice stubble burning for 10 major rice growing districts of Haryana state in India. These 10 districts contribute about 84 per cent of total rice area of the state. As the rice fields are immediately required to be vacated for the sowing of next crop the farmers opt for mechanized harvesting and easy way out of burning the stubbles in the field. Such burning result in release of polluting gases and aerosols. Besides, the heating of the soil kills the useful micro-flora of the soil causing soil degradation. Multi-date AWiFS data from Resourcesat 1 and 2 satellites acquired between October 16, 2013 to November 26, 2013 were used for estimating paddy stubble burning areas at different intervals for the year 2013 crop growing season. In season collected ground truth data using hand held GPS along with field photographs were used to identify paddy stubble burning areas and other land features. Complete enumeration approach and Iterative Self-organizing Data Analysis Technique (ISODATA) unsupervised classifier was used for digital analysis. Normalized Difference Vegetation Index (NDVI) of each date was also used with other spectral bands of temporal images. To improve the classification accuracy the non-agricultural areas were masked out. The area was estimated by computing pixels under the classified image mask. Progress of paddy stubble burning was estimated at different intervals for the year 2013 using available cloud free multi-date IRS-P6 AWiFS data to identify the crucial period when stubbles burning takes place in major area so that preventive measures can be taken to curb the menace.

  2. Projected changes in Malawi's growing season

    Science.gov (United States)

    Vizy, Edward K.; Cook, Kerry H.; Chimphamba, James; McCusker, Brent

    2015-09-01

    Regional climate model projections at 30-km resolution are used to predict future mid-century and late-century growing season changes over Malawi due to global warming under the Representative Concentration Pathway 8.5 business-as-usual emissions forcing scenario. Three different methods for estimating growing season characteristics are applied and evaluated. All three methods yield reasonable growing season length, onset, and demise date estimates over Malawi given the wide range of uncertainty of the observations. The projections indicate the likelihood for a shorter growing season in the future over Malawi south of 13.5°S. At mid-century the growing season length is predicted to be 20-40 % (20-55 days) shorter over the southernmost districts and 5-20 % (5-30 days) shorter over the central districts. By late-century the length is predicted to be 25-55 % (20-70 days) shorter with significant differences extending into northern Malawi. The shorter growing season is primarily associated with an earlier demise date, as no significant change in the onset date is predicted. Analysis of the regional circulation and horizontal moisture flux transport indicates that the earlier demise is associated with an intensification of the thermal low over the Kalahari Desert to the south and west of Malawi and an expansion of the mid-tropospheric Kalahari anticyclone over southern Africa. The stronger thermal low/anticyclone enhances the moisture flux divergence over Malawi suppressing the convective activity at the end of the wet season.

  3. Assessment of the Growing Season over the Unimodal Rainfall ...

    African Journals Online (AJOL)

    Most part of Tanzania experiences unimodal rainfall. The characteristics of rainfall such as its onset and cessation dates, dry and wet spell lengths, frequency and number of rainy days can be, used to determine the nature of growing season length of growing season end of season and its geographical variation both ...

  4. Effects of temperature and growing seasons on crop water ...

    African Journals Online (AJOL)

    Through shifting growing seasons and minimizing the effects of temperature for the major crops, significant amount of groundwater may be saved, which can reduce the production of costly desalinated water. Keywords: Water resources; conservation; crop water requirement; temperature; growing seasons; policy ...

  5. Civil conflict sensitivity to growing-season drought.

    Science.gov (United States)

    von Uexkull, Nina; Croicu, Mihai; Fjelde, Hanne; Buhaug, Halvard

    2016-11-01

    To date, the research community has failed to reach a consensus on the nature and significance of the relationship between climate variability and armed conflict. We argue that progress has been hampered by insufficient attention paid to the context in which droughts and other climatic extremes may increase the risk of violent mobilization. Addressing this shortcoming, this study presents an actor-oriented analysis of the drought-conflict relationship, focusing specifically on politically relevant ethnic groups and their sensitivity to growing-season drought under various political and socioeconomic contexts. To this end, we draw on new conflict event data that cover Asia and Africa, 1989-2014, updated spatial ethnic settlement data, and remote sensing data on agricultural land use. Our procedure allows quantifying, for each ethnic group, drought conditions during the growing season of the locally dominant crop. A comprehensive set of multilevel mixed effects models that account for the groups' livelihood, economic, and political vulnerabilities reveals that a drought under most conditions has little effect on the short-term risk that a group challenges the state by military means. However, for agriculturally dependent groups as well as politically excluded groups in very poor countries, a local drought is found to increase the likelihood of sustained violence. We interpret this as evidence of the reciprocal relationship between drought and conflict, whereby each phenomenon makes a group more vulnerable to the other.

  6. Freezing tolerance of wheat cultivars at the early growing season ...

    African Journals Online (AJOL)

    Cold stress is a worldwide abiotic stress in temperate regions that affects plant development and yield of winter wheat (Triticum aestivum L.) cultivars and other winter crops. This study was conducted to evaluate the effect of freezing stress at the early growing season on survival and also the relationship between resistances ...

  7. Trend Analysis of Droughts during Crop Growing Seasons of Nigeria

    Directory of Open Access Journals (Sweden)

    Mohammed Sanusi Shiru

    2018-03-01

    Full Text Available This study assesses the impacts of recent climate changes on drought-affected areas and the occurrence of droughts during different cropping seasons of Nigeria using the standardized precipitation evapotranspiration index (SPEI. The crop growing seasons are considered because the droughts for those periods are more destructive to national agricultural production. The Mann–Kendall test and binary logistic regression were used to quantify the trends in drought-affected areas and the occurrence of crop droughts with different areal extents, respectively. Gauge-based gridded rainfall and temperature data for the period 1961–2010 with spatial resolutions of 0.5° were used. Results showed an increase in the areal extent of droughts during some of the cropping seasons. The occurrences of droughts, particularly moderate droughts with smaller areal extents, were found to increase for all of the seasons. The SPEI values calculated decreased mostly in the regions where rainfall was decreasing. That is, the recent changes in climate were responsible for the increase in the occurrences of droughts with smaller areal extents. These trends in climate indicate that the occurrence of larger areal extent droughts may happen more frequently in Nigeria in the future.

  8. 317/319 phytoremediation site monitoring report - 2004 growing season.

    Energy Technology Data Exchange (ETDEWEB)

    Negri, M. C.; Gopalakrishnan, G.; Bogner, J.; Energy Systems

    2009-02-21

    In 1999, Argonne National Laboratory (ANL) designed and installed a series of engineered plantings consisting of a vegetative cover system and approximately 800 hybrid poplars and willows rooting at various predetermined depths. The plants were installed using various methods including Applied Natural Science's TreeWell{reg_sign} system. The goal of the installation was to protect downgradient surface and groundwater by hydraulic control of the contaminated plume by intercepting the contaminated groundwater with the tree roots, removing moisture from the upgradient soil area, reducing water infiltration, preventing soil erosion, degrading and/or transpiring the residual volatile organic compounds (VOCs), and removing tritium from the subsoil and groundwater. This report presents the results of the monitoring activities conducted by Argonne's Energy Systems Division (ES) in the growing season of 2004. Monitoring of the planted trees began soon after the trees were installed in 1999 and has been conducted every summer since then. As the trees grew and consolidated their growth into the contaminated soil and groundwater, their exposure to the contaminants was progressively shown through tissue sampling. Since the inception of the project, significant progress was made in the refinement and testing of the analytical method (for which no official method is available), the determination of the optimal tissue for sampling, and of the variability of the concentrations within a specific tree. An understanding has also been developed on background concentrations of VOCs, and how to discriminate between VOCs that are associated with plant tissue because of aerial or of soil/groundwater uptake pathways. Also, during the 2003 sampling campaign, core samples from tree trunks were collected for the first time (the trees were large enough to stand the procedure). Data collected from the French Drain area last year supported the hypothesis that a correlation was present

  9. Temperature Sensitivity of Soil Respiration to Nitrogen Fertilization: Varying Effects between Growing and Non-Growing Seasons.

    Science.gov (United States)

    Liu, Qingfang; Wang, Rui; Li, Rujian; Hu, Yaxian; Guo, Shengli

    2016-01-01

    Nitrogen (N) fertilization has a considerable effect on food production and carbon cycling in agro-ecosystems. However, the impacts of N fertilization rates on the temperature sensitivity of soil respiration (Q10) were controversial. Five N rates (N0, N45, N90, N135, and N180) were applied to a continuous winter wheat (Triticum aestivum L.) crop on the semi-arid Loess Plateau, and the in situ soil respiration was monitored during five consecutive years from 2008 to 2013. During the growing season, the mean soil respiration rates increased with increasing N fertilization rates, peaking at 1.53 μmol m-2s-1 in the N135 treatment. A similar dynamic pattern was observed during the non-growing season, yet on average with 7.3% greater soil respiration rates than the growing season. In general for all the N fertilization treatments, the mean Q10 value during the non-growing season was significantly greater than that during the growing season. As N fertilization rates increased, the Q10 values did not change significantly in the growing season but significantly decreased in the non-growing season. Overall, N fertilization markedly influenced soil respirations and Q10 values, in particular posing distinct effects on the Q10 values between the growing and non-growing seasons.

  10. Progress toward seasonal prediction in the tropics

    Science.gov (United States)

    Knaff, John Albert

    Seasonal prediction in the tropics has been a slowly developing, yet very important topic in Atmospheric Science. Its slow evolution is a product of its history, a history determined by the rise and fall of empires, technological advances, and scientific opinions, but motivated ultimately by profit. In recent years, long-lead forecasting techniques in the tropics have again become popular. The occurrence of strong El Nino/Southern Oscillation (ENSO) events, droughts, floods, and intense landfalling tropical cyclones, has again prompted the meteorological community to use their knowledge to create useful seasonal forecasts for several regions of the tropics. Such forecasts will facilitate better management of natural resources, disaster preparation, and economic growth in these regions. Much has been learned about seasonal forecasting in the tropics in the last 125 years and much will be learned in the future, but progress is gained slowly by the piecing together of a great number of observation studies. This paper details but a few such studies. Within, the history of seasonal prediction in the tropics is discussed. Following this discussion the paper examines the physical implications of summertime sea level pressure anomalies (SLPAs) in the tropical Atlantic, the development of a simple regression model to predict June through September SLPAs in the Caribbean Sea region, and the development of a statistical ENSO prediction method which is based entirely on the optimal combination of persistence, trends of initial conditions and climatology. The future of seasonal forecasting in the tropics is bright. New technology along with improved datasets is allowing diagnostic and predictive studies that were once thought too exhaustive to be undertaken. This optimistic opinion must be tempered by this fields long history. Public and scientific opinion can rapidly change if seasonal prediction is not approached responsibly. This responsibility entails a rigorous definition

  11. Growing season methane budget of an Inner Mongolian steppe

    Science.gov (United States)

    Liu, Chunyan; Holst, Jirko; Yao, Zhisheng; Brüggemann, Nicolas; Butterbach-Bahl, Klaus; Han, Shenghui; Han, Xingguo; Tas, Bart; Susenbeth, Andreas; Zheng, Xunhua

    We present a methane (CH 4) budget for the area of the Baiyinxile Livestock Farm, which comprises approximately 1/3 of the Xilin river catchment in central Inner Mongolia, P.R. China. The budget calculations comprise the contributions of natural sources and sinks as well as sources related to the main land-use in this region (non-nomadic pastoralism) during the growing season (May-September). We identified as important CH 4 sources floodplains (mean 1.55 ± 0.97 mg CH 4-C m -2 h -1) and domestic ruminants, which are mainly sheep in this area. Within the floodplain significant differences between investigated positions were detected, whereby only positions close-by the river or bayous emitted large amounts of CH 4 (mean up to 6.21 ± 1.83 mg CH 4-C m -2 h -1). Further CH 4 sources were sheepfolds (0.08-0.91 mg CH 4-C m -2 h -1) and pasture faeces (1.34 ± 0.22 mg CH 4-C g -1 faeces dry weight), but they did not play a significant role for the CH 4 budget. In contrast, dung heaps were not a net source of CH 4 (0.0 ± 0.2 for an old and 0.0 ± 0.3 μg CH 4-C kg -1 h -1 for a new dung heap). Trace gas measurements along two landscape transects (volcano, hill slope) revealed expectedly a mean CH 4 uptake (volcano: 76.5 ± 4.3; hill: 28.3 ± 5.3 μg CH 4-C m -2 h -1), which is typical for the aerobic soils in this and other steppe ecosystems. The observed fluxes were rarely influenced by topography. The CH 4 emissions from the floodplain and the sheep were not compensated by the CH 4 oxidation of aerobic steppe soils and thus, this managed semi-arid grassland did not serve as a terrestrial sink, but as a source for this globally important greenhouse gas. The source strength amounted to 1.5-3.6 kg CH 4-C ha -1 during the growing season, corresponding to 3.5-8.7 kg C ha -1 yr -1.

  12. Impact of Growing-Season Meteorology on Japonica Rice Productivity in Northeastern China

    Science.gov (United States)

    Yu, W.; Zhang, Y. E.; Wang, Y.; Liu, J. J.; Chen, W.; Seng, S. S.; Zhuang, J. Y.; Gao, L. W.; Ahmed, A.-G.; Li, Z. M.; Li, G. Q.; Xu, S. W.

    2017-10-01

    Meteorological factors have major impact on crop productivity in the world. Many researchers have evaluated the possible impact of climate change on crop yields using models. Here we use a 1980–2015panel dataset from China Agricultural Cost and Return Yearbook to investigate the meteorological impact on Chinese Japonica rice yield growth. We find that average temperature has significantly positive effect on rice yields; while maximum temperature and minimum temperature have negative effect on rice yield. Physicalinputs and time trend (technological progress) into the crop yield have an accurate estimation on crop yields. Means including irrigation or drainage could use during growing season.

  13. Performance of machinery in potato production in one growing season

    Directory of Open Access Journals (Sweden)

    Kun Zhou

    2015-12-01

    Full Text Available Statistics on the machinery performance are essential for farm managers to make better decisions. In this paper, the performance of all machineries in five sequential operations, namely bed forming, stone separation, planting, spraying and harvesting in the potato production system, were investigated during one growing season. In order to analyse and decompose the recorded GPS data into various time and distance elements for estimation of the machinery performance, an automatic GPS analysis tool was developed. The field efficiency and field capacity were estimated for each operation. Specifically, the measured average field efficiency was 71.3% for bed forming, 68.5% for stone separation, 40.3% for planting, 69.7% for spraying, and 67.4% for harvesting. The measured average field capacities were 1.46 ha/h, 0.53 ha/h, 0.47 ha/h, 10.21 ha/h, 0.51 ha/h, for the bed forming, stone separation, planting, spraying, and harvesting operations, respectively. These results deviate from the corresponding estimations calculated based on norm data from the American Society of Agricultural and Biological Engineers (ASABE. The deviations indicate that norms provided by ASABE cannot be used directly for the prediction of performance of the machinery used in this work. Moreover, the measured data of bed forming and stone separation could be used as supplementary data for the ASABE which does not provide performance norms for these two operations. The gained results can help farm managers to make better management and operational decisions that result in potential improvement in productivity and profitability as well as in potential environmental benefits.

  14. Performance of machinery in potato production in one growing season

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, K.; Jensen, A.L.; Bochtis, D.D.; Sørensen, C.G.

    2015-07-01

    Statistics on the machinery performance are essential for farm managers to make better decisions. In this paper, the performance of all machineries in five sequential operations, namely bed forming, stone separation, planting, spraying and harvesting in the potato production system, were investigated during one growing season. In order to analyse and decompose the recorded GPS data into various time and distance elements for estimation of the machinery performance, an automatic GPS analysis tool was developed. The field efficiency and field capacity were estimated for each operation. Specifically, the measured average field efficiency was 71.3% for bed forming, 68.5% for stone separation, 40.3% for planting, 69.7% for spraying, and 67.4% for harvesting. The measured average field capacities were 1.46 ha/h, 0.53 ha/h, 0.47 ha/h, 10.21 ha/h, 0.51 ha/h, for the bed forming, stone separation, planting, spraying, and harvesting operations, respectively. These results deviate from the corresponding estimations calculated based on norm data from the American Society of Agricultural and Biological Engineers (ASABE). The deviations indicate that norms provided by ASABE cannot be used directly for the prediction of performance of the machinery used in this work. Moreover, the measured data of bed forming and stone separation could be used as supplementary data for the ASABE which does not provide performance norms for these two operations. The gained results can help farm managers to make better management and operational decisions that result in potential improvement in productivity and profitability as well as in potential environmental benefits. (Author)

  15. Effects of Continuous Flooding in No-rice Growing Season on CH4 and CO2 Emissions of Rice Growing Season with Straw Returning

    Directory of Open Access Journals (Sweden)

    XU Xiang-yu

    2017-03-01

    Full Text Available Straw returning is a straw utilization pattern which is widely promoted in China. It can increase the soil organic carbon and fertility, but straw returning also increase the CH4 and CO2 emissions. The effects of continuous flooding in no rice growing season on CH4 and CO2 emission in rice season with straw returning is not clear. This study was conducted with two different water managements in no rice growing season, one was the middle rice-natural drainage (RD and another was the middle rice-continuous flooding (RW. The aim was to investigate the characteristic of CH4 and CO2 emission flux in rice season under different water management with straw returning, and to provide data support for accurate assessment of paddy greenhouse gas emissions. The results showed that RD significantly reduced the CH4 accumulation emission flux in rice growing season compared with the RW, and 80% total CH4 emission flux in rice growing season was emission before the first drainage whether RD or RW. RW could cutdown the CO2 accumulation emission flux in rice growing season compared with RD, and about 60% total CO2 emission flux in rice growing season was emission after the first drainage whether RD or RW. RW reduced the soil NO3--N, NH4+-N and DOC concentration in rice growing season, and decreased the Eh value at 10 cm soil layer, but increased the acetic acid concentration. This might be the main reason of increasing the CH4 accumulation emission flux from RD.

  16. 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.

  17. Impacts of climate change on the growing season in the United States

    Science.gov (United States)

    Markstrom, Steven L.; Hay, Lauren E.

    2011-01-01

    Understanding the effects of climate change on the vegetative growing season is key to quantifying future hydrologic water budget conditions. The U.S. Geological Survey modeled changes in future growing season length at 14 basins across 11 states. Simulations for each basin were generated using five general circulation models with three emission scenarios as inputs to the Precipitation-Runoff Modeling System (PRMS). PRMS is a deterministic, distributed-parameter, watershed model developed to simulate the effects of various combinations of precipitation, climate, and land use on watershed response. PRMS was modified to include a growing season calculation in this study. The growing season was examined for trends in the total length (annual), as well as changes in the timing of onset (spring) and the end (fall) of the growing season. The results showed an increase in the annual growing season length in all 14 basins, averaging 27–47 days for the three emission scenarios. The change in the spring and fall growing season onset and end varied across the 14 basins, with larger increases in the total length of the growing season occurring in the mountainous regions and smaller increases occurring in the Midwest, Northeast, and Southeast regions. The Clear Creek basin, 1 of the 14 basins in this study, was evaluated to examine the growing season length determined by emission scenario, as compared to a growing season length fixed baseline condition. The Clear Creek basin showed substantial variation in hydrologic responses, including streamflow, as a result of growing season length determined by emission scenario.

  18. A synthesis of growing-season, non-growing season, and annual methane emission measurements among temperate, boreal, and tundra wetlands and uplands

    Science.gov (United States)

    Treat, C. C.; Bloom, A. A.; Marushchak, M. E.

    2017-12-01

    Wetlands are the largest natural source of methane to the atmosphere, while upland soils are a consistent sink of atmospheric methane. Wetland methane emissions are highly variable among sites, years, and temporal scales due to differences in production, oxidation, and transport pathways. Currently, process model predictions of methane emissions from wetlands remain challenging due to uncertain parameterizations of net methane production and emission processes. Here, we synthesize growing season, non-growing season, and annual methane emissions from chamber and eddy-covariance measurements for more than 150 sites in undisturbed temperate, boreal, and tundra wetlands and uplands. We compare the magnitude of fluxes among regions, wetland classifications, vegetation classifications, and environmental variables. Growing season measurements were most abundant in bogs, fens, and tundra sites, while marshes and swamps were relatively undersampled. Annual methane emissions were largest from marshes and lowest from upland mineral soils. Non-growing season emissions accounted for large fraction of annual methane emissions, especially in tundra sites. These results provide constraints for methane emissions from temporal, boreal, and arctic wetlands utilizing the numerous flux measurements conducted over the past 25 years. We find that state-of-the-art model ensembles are seasonally biased; in particular, the vast majority of models overestimate predictions of the growing season to annual wetland methane emission ratio across all biomes.

  19. 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.)

  20. Lengthening of the growing season in wheat and maize producing regions

    Directory of Open Access Journals (Sweden)

    Brigitte Mueller

    2015-09-01

    Full Text Available Human-induced increases in atmospheric greenhouse gas concentrations have led to rising global temperatures. Here we investigate changes in an annual temperature-based index, the growing season length, defined as the number of days with temperature above 5 °C. We show that over extratropical regions where wheat and maize are harvested, the increase in growing season length from 1956 to 2005 can be attributed to increasing greenhouse gas concentrations. Our analyses also show that climate change has increased the probability of extremely long growing seasons by a factor of 25, and decreased the probability of extremely short growing seasons. A lengthening of the growing season in regions with these mostly rain-fed crops could improve yields, provided that water availability does not become an issue. An expansion of areas with more than 150 days of growing season into the northern latitudes makes more land potentially available for planting wheat and maize. Furthermore, double-cropping can become an alternative to current practices in areas with very long growing seasons which are also shown to increase with a warming climate. These results suggest that there is a strong impact of anthropogenic climate change on growing season length. However, in some regions and with further exacerbated climate change, high temperatures may already be or may become a limiting factor for plant productivity.

  1. Second crop growing during the dry season in Lower Burma

    NARCIS (Netherlands)

    Wit, de C.T.

    1958-01-01

    On the clay soils of the Irrawaddi delta, a considerable amount of water can be conserved for growing a second crop after rice, provided that the fields are ploughed while still wet, immediately after the harvest. Estimated yields of cowpeas (Vigna sinensis) grown after rice, based on

  2. New England observed and predicted Julian day of maximum growing season stream/river temperature points

    Data.gov (United States)

    U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted Julian day of maximum growing season stream/river temperatures in New England based on a spatial...

  3. New England observed and predicted growing season maximum stream/river temperature points

    Data.gov (United States)

    U.S. Environmental Protection Agency — The shapefile contains points with associated observed and predicted growing season maximum stream/river temperatures in New England based on a spatial statistical...

  4. 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...

  5. Nonvascular contribution to ecosystem NPP in a subarctic heath during early and late growing season

    DEFF Research Database (Denmark)

    Campioli, Matteo; Samson, Roeland; Michelsen, Anders

    2009-01-01

    Bryophytes and lichens abound in many arctic ecosystems and can contribute substantially to the ecosystem net primary production (NPP). Because of their growth seasonality and their potential for growth out of the growing season peak, bryophyte and lichen contribution to NPP may be particularly...

  6. Timing and duration of European larch growing season along altitudinal gradients in the Swiss Alps.

    Science.gov (United States)

    Moser, Lea; Fonti, Patrick; Büntgen, Ulf; Esper, Jan; Luterbacher, Jürg; Franzen, Julia; Frank, David

    2010-02-01

    The 2007 European larch (Larix decidua Mill.) growing season was monitored along two elevational transects in the Lötschental valley in the Swiss Alps. Phenological observations and weekly microcore sampling of 28 larch trees were conducted between April and October 2007 at seven study sites regularly spaced from 1350 to 2150 m a.s.l. on northwest- and southeast-facing slopes. The developmental stages of nearly 75,000 individual cells assessed on 1200 thin sections were used to investigate the links between the trees' thermal regimes and growth phases including the beginning and ending of cell enlargement, wall thickening and maturation of the stem wood. Needles appeared approximately 3-4 weeks earlier than stem growth. The duration of ring formation lasted from mid-May to the end of October, with the length of the growing season decreasing along elevation from 137 to 101 days. The onset of the different growing seasons changed by 3-4 days per 100 m elevation; the ending of the growing season, however, appeared minimally related to altitude. If associated with the monitored altitudinal lapse rate of -0.5 degrees C per 100 m, these results translate into a lengthening of the growing season by approximately 7 days per degree Celsius. This study provides new data on the timing and duration of basic growth processes and contributes to quantification of the impacts of global warming on tree growth and productivity.

  7. Non-growing season methane emissions are a significant component of annual emissions across northern ecosystems.

    Science.gov (United States)

    Treat, Claire C; Bloom, A Anthony; Marushchak, Maija E

    2018-03-22

    Wetlands are the single largest natural source of atmospheric methane (CH 4 ), a greenhouse gas, and occur extensively in the northern hemisphere. Large discrepancies remain between "bottom-up" and "top-down" estimates of northern CH 4 emissions. To explore whether these discrepancies are due to poor representation of non-growing season CH 4 emissions, we synthesized non-growing season and annual CH 4 flux measurements from temperate, boreal, and tundra wetlands and uplands. Median non-growing season wetland emissions ranged from 0.9 g m -2 in bogs to 5.2 g m -2 in marshes and were dependent on moisture, vegetation, and permafrost. Annual wetland emissions ranged from 0.9 g m -2 y -1 in tundra bogs to 78 g m -2 y -1 in temperate marshes. Uplands varied from CH 4 sinks to CH 4 sources with a median annual flux of 0.0 ± 0.2 g m -2 y -1 . The measured fraction of annual CH 4 emissions during the non-growing season (observed: 13 to 47%) was significantly larger than was predicted by two process-based model ensembles, especially between 40-60º N (modeled: 4 to 17%). Constraining the model ensembles with the measured non-growing fraction increased total non-growing season and annual CH 4 emissions. Using this constraint, the modeled non-growing season wetland CH 4 flux from >40° north was 6.1 ± 1.5 Tg y -1 , three times greater than the non-growing season emissions of the unconstrained model ensemble. The annual wetland CH 4 flux was 37 ± 7 Tg y -1 from the data-constrained model ensemble, 25% larger than the unconstrained ensemble. Considering non-growing season processes is critical for accurately estimating CH 4 emissions from high latitude ecosystems, and necessary for constraining the role of wetland emissions in a warming climate. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  8. More CH4 is emitted during the fallow than during the growing season in a Mediterranean rice agrosystems

    Science.gov (United States)

    Martínez-Eixarch, Maite; Ibàñez, Carles; Alcaraz, Carles; Viñas, Marc; Aranda, Xavier; Saldaña, J. Antonio

    2017-04-01

    Paddy rice fields are an important source of greenhouse gas emissions (GHG) as they contribute 5 to 20 % of the global anthropogenic CH4 emissions. The Ebre Delta (Catalonia, NE Spain) is one of the most important wetland complexes in the Western Mediterranean with 65 % of its area covered by rice fields. The results herein presented assess the annual pattern of CH4 emissions from paddy rice in Ebre Delta, including the growing and fallow seasons as well as the major environmental variables modulating such emissions. Fifteen rice fields covering the geo-physical variability of the Ebre Delta were selected for GHG monitoring. Common agronomic management was practiced: water direct-seeding, permanent flooding and moderate mineral fertilization during the growing season and straw incorporation, progressive drainage of the fields after the harvest. Fields are left fallow during the winter. GHG were monthly sampled, from May to December in 2015. In each field, three closed chambers were used; from each of these, four gas samples were taken over a 30-minute period. Simultaneously, hydrological regime, soil physic-chemical parameters and plant cover were measured. GHG were analysed by gas chromatography. A Generalized linear model analysis (GLM) was performed to assess the most important influencing factors on CH4 emissions. An information-theoretic approach was used to find the best approximating models. Overall, the CH4 emissions showed a bi-modal pattern, with peaks in July-August and in October. Emissions rates ranged from 2.1 ± 0.5 to 7.5 ± 1.4 mg C-CH4 m-2 h-1 in the growing season (May to September) and from 25.0 ± 5.7 to 20.1 ± 3.3 mg C-CH4 m-2 h-1 at post-harvest (October to December). In total, 314 kg C-CH4 ha-1 were emitted from Ebre Delta rice fields, of which 70 % during post-harvest. Larger off-season emissions were likely induced by straw incorporation. The results of the GLM-IT analysis revealed that during the growing season, soil Eh and water level

  9. The influence of environmental factors on growing season length for garden pea (Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    В. М. Стригун

    2014-12-01

    Full Text Available The results obtained during observations of the growing season of pea collection varieties in different years in terms of interphase periods are presented. The dependence of the growing season length for varieties of various maturity groups on the duration of certain phases of plant growth (seedling, flowering, ripening,  ambient environment (temperature, humidity, daylight hours, processing (seed preparation, line production maintenance and genetic factors (sequential node of the first inflorescence formation are shown. According to the study   results the varieties-sources of «growing season length» characteristic were specified that have been used as components for breeding in the selection process when creating new domestic varieties.

  10. Planting geometry and growing season effects on the growth and yield of dryland cotton

    Science.gov (United States)

    The declining Ogallala Aquifer beneath the Southern High Plains may necessitate dryland crop production and cotton (Gossypium hirsutum L.) is a well-adapted and potentially profitable alternative crop. The limited growing season duration of the Texas Panhandle and southwestern Kansas, however, impos...

  11. Effects of urban green infrastructure (UGI) on local outdoor microclimate during the growing season

    NARCIS (Netherlands)

    Wang, Yafei; Bakker, Frank; Groot, de Rudolf; Wörtche, Heinrich; Leemans, Rik

    2015-01-01

    This study analyzed how the variations of plant area index (PAI) and weather conditions alter the influence of urban green infrastructure (UGI) on microclimate. To observe how diverse UGIs affect the ambient microclimate through the seasons, microclimatic data were measured during the growing

  12. Variation in damage from growing-season frosts among open-pollinated families of red alder.

    Science.gov (United States)

    Kevin C. Peeler; Dean S. DeBell

    1987-01-01

    Repeated growing-season frosts during late April and early May 1985 caused extensive damage to red alder (Alnus rubra Bong.) seedlings in a newly planted research trial in western Washington. About two-thirds of the seedlings were severely damaged (entire stem damaged or necrotic). Such damage varied by family, from 50 percent of seedlings in the...

  13. Rumen degradation characteristics of perennial ryegrass cultivars during the growing season

    NARCIS (Netherlands)

    Tas, B.M.; Taweel, H.Z.; Smit, H.J.; Elgersma, A.; Dijkstra, J.; Tamminga, S.

    2006-01-01

    The objective of this experiment was to evaluate the effects of sward characteristics and chemical composition of eight diploid perennial ryegrass cultivars during the growing season on degradation characteristics in the rumen of dairy cows. As part of an indoor-feeding experiment with dairy cows,

  14. The flux of ozone to a maize crop and the underlying soil during a growing season

    NARCIS (Netherlands)

    Pul, van W.A.J.

    1992-01-01

    To observe the flux or deposition of ozone above a maize crop, experiments were carried out during the growing season of maize in 1988. The flux of ozone was determined using meteorological techniques. The measurements used in the present study were carried out under atmospheric conditions

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

    Science.gov (United States)

    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 48 states. Data were provided by Dr. Kenneth Kunkel of NOAA's Cooperative Institute for Climate and Satellites. For more information: www.epa.gov/climatechange/science/indicators

  16. Crop water stress maps for an entire growing season from visible and thermal UAV imagery

    DEFF Research Database (Denmark)

    Nielsen, Helene Hoffmann Munk; Jensen, Rasmus; Thomsen, Anton Gårde

    2016-01-01

    season because at this stage the remote sensing data represent crop water availability to a greater extent than they do in the early growing season, and because the WDI accounts for areas of ripe crops that no longer have the same need for irrigation. WDI maps can potentially serve as water stress maps......This study investigates whether a water deficit index (WDI) based on imagery from unmanned aerial vehicles (UAVs) can provide accurate crop water stress maps at different growth stages of barley and in differing weather situations. Data from both the early and late growing season are included...... to investigate whether the WDI has the unique potential to be applicable both when the land surface is partly composed of bare soil and when crops on the land surface are senescing. The WDI differs from the more commonly applied crop water stress index (CWSI) in that it uses both a spectral vegetation index (VI...

  17. Snowmelt timing, phenology, and growing season length in conifer forests of Crater Lake National Park, USA

    Science.gov (United States)

    O'Leary, Donal S.; Kellermann, Jherime L.; Wayne, Chris

    2018-02-01

    Anthropogenic climate change is having significant impacts on montane and high-elevation areas globally. Warmer winter temperatures are driving reduced snowpack in the western USA with broad potential impacts on ecosystem dynamics of particular concern for protected areas. Vegetation phenology is a sensitive indicator of ecological response to climate change and is associated with snowmelt timing. Human monitoring of climate impacts can be resource prohibitive for land management agencies, whereas remotely sensed phenology observations are freely available at a range of spatiotemporal scales. Little work has been done in regions dominated by evergreen conifer cover, which represents many mountain regions at temperate latitudes. We used moderate resolution imaging spectroradiometer (MODIS) data to assess the influence of snowmelt timing and elevation on five phenology metrics (green up, maximum greenness, senescence, dormancy, and growing season length) within Crater Lake National Park, Oregon, USA from 2001 to 2012. Earlier annual mean snowmelt timing was significantly correlated with earlier onset of green up at the landscape scale. Snowmelt timing and elevation have significant explanatory power for phenology, though with high variability. Elevation has a moderate control on early season indicators such as snowmelt timing and green up and less on late-season variables such as senescence and growing season length. PCA results show that early season indicators and late season indicators vary independently. These results have important implications for ecosystem dynamics, management, and conservation, particularly of species such as whitebark pine ( Pinus albicaulis) in alpine and subalpine areas.

  18. Snowmelt timing, phenology, and growing season length in conifer forests of Crater Lake National Park, USA.

    Science.gov (United States)

    O'Leary, Donal S; Kellermann, Jherime L; Wayne, Chris

    2018-02-01

    Anthropogenic climate change is having significant impacts on montane and high-elevation areas globally. Warmer winter temperatures are driving reduced snowpack in the western USA with broad potential impacts on ecosystem dynamics of particular concern for protected areas. Vegetation phenology is a sensitive indicator of ecological response to climate change and is associated with snowmelt timing. Human monitoring of climate impacts can be resource prohibitive for land management agencies, whereas remotely sensed phenology observations are freely available at a range of spatiotemporal scales. Little work has been done in regions dominated by evergreen conifer cover, which represents many mountain regions at temperate latitudes. We used moderate resolution imaging spectroradiometer (MODIS) data to assess the influence of snowmelt timing and elevation on five phenology metrics (green up, maximum greenness, senescence, dormancy, and growing season length) within Crater Lake National Park, Oregon, USA from 2001 to 2012. Earlier annual mean snowmelt timing was significantly correlated with earlier onset of green up at the landscape scale. Snowmelt timing and elevation have significant explanatory power for phenology, though with high variability. Elevation has a moderate control on early season indicators such as snowmelt timing and green up and less on late-season variables such as senescence and growing season length. PCA results show that early season indicators and late season indicators vary independently. These results have important implications for ecosystem dynamics, management, and conservation, particularly of species such as whitebark pine (Pinus albicaulis) in alpine and subalpine areas.

  19. How well do degree days over the growing season capture the effect of climate on farmland values?

    International Nuclear Information System (INIS)

    Massetti, Emanuele; Mendelsohn, Robert; Chonabayashi, Shun

    2016-01-01

    Farmland values have traditionally been valued using seasonal temperature and precipitation but degree days over the growing season offer a more compact alternative. We find that degree days and daily temperature are interchangeable over the growing season. However, the impact of degree days in spring and summer is quite different. Climate effects outside the growing season are also significant. Cross sectional evidence suggests seasonal temperature and precipitation are very important whereas temperature extremes have relatively small effects. - Highlights: • The use of degree days in Ricardian models is reviewed. • Daily temperature and degree days are interchangeable over the growing season. • Seasonal climate effects are significantly different. • The four season average temperature model is superior to the degree days model.

  20. Effects of plant cover on soil N mineralization during the growing season in a sandy soil

    Science.gov (United States)

    Yao, Y.; Shao, M.; Wei, X.; Fu, X.

    2017-12-01

    Soil nitrogen (N) mineralization and its availability plays a vital role in regulating ecosystem productivity and C cycling, particularly in semiarid and desertified ecosystems. To determine the effect of plant cover on N turnover in a sandy soil ecosystem, we measured soil N mineralization and inorganic N pools in soil solution during growing season in a sandy soil covered with various plant species (Artemisia desertorum, Salix psammophila, and Caragana korshinskii). A bare sandy soil without any plant was selected as control. Inorganic N pools and N mineralization rates decreased overtime during the growing season, and were not affected by soil depth in bare land soils, but were significantly higher at the 0-10 cm layer than those at the 10-20 cm soil layer under any plant species. Soil inorganic N pool was dominated by ammonium, and N mineralization was dominated by nitrification regardless of soil depth and plant cover. Soils under C. korshinskii have significant higher inorganic N pools and N mineralization rate than soils under bare land and A. desertorum and S. psammophila, and the effects of plant cover were greater at the 0-10 cm soil layer than at the 10-20 cm layer. The effects of C. korshinskii on soil inorganic N pools and mineralization rate varied with the stage of growing season, with greater effects on N pools in the middle growing season, and greater effects on mineralization rate at the last half of the growing season. The results from this study indicate that introduction of C. korshinskii has the potential to increase soil N turnover and availability in sandy soils, and thus to decrease N limitation. Caragana korshinskii is therefore recommend for the remediation of the desertified land.

  1. Reanalysis data underestimate significant changes in growing season weather in Kazakhstan

    International Nuclear Information System (INIS)

    Wright, C K; Henebry, G M; De Beurs, K M; Akhmadieva, Z K; Groisman, P Y

    2009-01-01

    We present time series analyses of recently compiled climate station data which allowed us to assess contemporary trends in growing season weather across Kazakhstan as drivers of a significant decline in growing season normalized difference vegetation index (NDVI) recently observed by satellite remote sensing across much of Central Asia. We used a robust nonparametric time series analysis method, the seasonal Kendall trend test to analyze georeferenced time series of accumulated growing season precipitation (APPT) and accumulated growing degree-days (AGDD). Over the period 2000-2006 we found geographically extensive, statistically significant (p<0.05) decreasing trends in APPT and increasing trends in AGDD. The temperature trends were especially apparent during the warm season and coincided with precipitation decreases in northwest Kazakhstan, indicating that pervasive drought conditions and higher temperature excursions were the likely drivers of NDVI declines observed in Kazakhstan over the same period. We also compared the APPT and AGDD trends at individual stations with results from trend analysis of gridded monthly precipitation data from the Global Precipitation Climatology Centre (GPCC) Full Data Reanalysis v4 and gridded daily near surface air temperature from the National Centers for Climate Prediction Reanalysis v2 (NCEP R2). We found substantial deviation between the station and the reanalysis trends, suggesting that GPCC and NCEP data substantially underestimate the geographic extent of recent drought in Kazakhstan. Although gridded climate products offer many advantages in ease of use and complete coverage, our findings for Kazakhstan should serve as a caveat against uncritical use of GPCC and NCEP reanalysis data and demonstrate the importance of compiling and standardizing daily climate data from data-sparse regions like Central Asia.

  2. 317/319 Phytoremediation site monitoring report - 2009 growing season : final report.

    Energy Technology Data Exchange (ETDEWEB)

    Negri, C .N.; Benda, P. L.; Gopalakrishnan, G.; Energy Systems

    2010-02-10

    In 1999, Argonne National Laboratory (Argonne) designed and installed a series of engineered plantings consisting of a vegetative cover system and approximately 800 hybrid poplars and willows rooting at various predetermined depths. The plants were installed using various methods including Applied Natural Science's TreeWell{reg_sign} system. The goal of the installation was to protect downgradient surface and groundwater by intercepting the contaminated groundwater with the tree roots, removing moisture from the upgradient soil area, reducing water infiltration, preventing soil erosion, degrading and/or transpiring the residual volatile organic compounds (VOCs), and removing tritium from the subsoil and groundwater. This report presents the results of the monitoring activities conducted by Argonne's Energy Systems (ES) Division in the growing season of 2009. Monitoring of the planted trees began soon after the trees were installed in 1999 and has been conducted every summer since then. As the trees grew and consolidated their growth into the contaminated soil and groundwater, their exposure to the contaminants was progressively shown through tissue sampling. During the 2009 sampling campaign, VOC concentrations found in the French Drain area were in general consistent with or slightly lower than the 2008 results. Additionally, closely repeated, stand wide analyses showed contaminant fluctuations that may indicate short-term contaminant depletion in the area of interest of roots. This data will be useful to determine short-term removal rate by the trees. As in previous years, levels in the Hydraulic Control Area were close to background levels except for a few exceptions.

  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. Growing season carries stronger contributions to albedo dynamics on the Tibetan plateau.

    Science.gov (United States)

    Tian, Li; Chen, Jiquan; Zhang, Yangjian

    2017-01-01

    The Tibetan Plateau has experienced higher-than-global-average climate warming in recent decades, resulting in many significant changes in ecosystem structure and function. Among them is albedo, which bridges the causes and consequences of land surface processes and climate. The plateau is covered by snow/ice and vegetation in the non-growing season (nGS) and growing season (GS), respectively. Based on the MODIS products, we investigated snow/ice cover and vegetation greenness in relation to the spatiotemporal changes of albedo on the Tibetan Plateau from 2000 through 2013. A synchronous relationship was found between the change in GSNDVI and GSalbedo over time and across the Tibetan landscapes. We found that the annual average albedo had a decreasing trend, but that the albedo had slightly increased during the nGS and decreased during the GS. Across the landscapes, the nGSalbedo fluctuated in a synchronous pattern with snow/ice cover. Temporally, monthly snow/ice coverage also had a high correspondence with albedo, except in April and October. We detected clear dependencies of albedo on elevation. With the rise in altitude, the nGSalbedo decreased below 4000 m, but increased for elevations of 4500-5500 m. Above 5500 m, the nGSalbedo decreased, which was in accordance with the decreased amount of snow/ice coverage and the increased soil moisture on the plateau. More importantly, the decreasing albedo in the most recent decade appeared to be caused primarily by lowered growing season albedo.

  5. Relationships between storage protein composition, protein content, growing season and flour quaility of bread wheat

    DEFF Research Database (Denmark)

    Faergestad, E.M.; Flaete, N.E.S.; Magnus, E.M.

    2004-01-01

    The storage protein composition from the Glu-1, Glu-3 and Gli-1 loci encoding high and low molecular weight glutenin subunits (HMW-GS and LMW-GS) and gliadins, respectively, was determined on 30 wheat (T aestivum L) genotypes from three growing seasons. The gliadins and the LMW-GS were identified...... estimated in the model, gave similar results to ANOVA in identifying quality related protein alleles. The applicability of the multivariate approach in proteomics is, however, much wider.......The storage protein composition from the Glu-1, Glu-3 and Gli-1 loci encoding high and low molecular weight glutenin subunits (HMW-GS and LMW-GS) and gliadins, respectively, was determined on 30 wheat (T aestivum L) genotypes from three growing seasons. The gliadins and the LMW-GS were identified...... of the protein alleles, the protein content and the growing seasons are related to flour quality. The year of growth had a large impact on mixograph peak time. When predicting mixograph peak time from the presence or absence of significant proteins and the year of growth, 70% of the variability in mixograph peak...

  6. Comparison of phenology models for predicting the onset of growing season over the Northern Hemisphere.

    Directory of Open Access Journals (Sweden)

    Yang Fu

    Full Text Available Vegetation phenology models are important for examining the impact of climate change on the length of the growing season and carbon cycles in terrestrial ecosystems. However, large uncertainties in present phenology models make accurate assessment of the beginning of the growing season (BGS a challenge. In this study, based on the satellite-based phenology product (i.e. the V005 MODIS Land Cover Dynamics (MCD12Q2 product, we calibrated four phenology models, compared their relative strength to predict vegetation phenology; and assessed the spatial pattern and interannual variability of BGS in the Northern Hemisphere. The results indicated that parameter calibration significantly influences the models' accuracy. All models showed good performance in cool regions but poor performance in warm regions. On average, they explained about 67% (the Growing Degree Day model, 79% (the Biome-BGC phenology model, 73% (the Number of Growing Days model and 68% (the Number of Chilling Days-Growing Degree Day model of the BGS variations over the Northern Hemisphere. There were substantial differences in BGS simulations among the four phenology models. Overall, the Biome-BGC phenology model performed best in predicting the BGS, and showed low biases in most boreal and cool regions. Compared with the other three models, the two-phase phenology model (NCD-GDD showed the lowest correlation and largest biases with the MODIS phenology product, although it could catch the interannual variations well for some vegetation types. Our study highlights the need for further improvements by integrating the effects of water availability, especially for plants growing in low latitudes, and the physiological adaptation of plants into phenology models.

  7. Comparison of phenology models for predicting the onset of growing season over the Northern Hemisphere.

    Science.gov (United States)

    Fu, Yang; Zhang, Haicheng; Dong, Wenjie; Yuan, Wenping

    2014-01-01

    Vegetation phenology models are important for examining the impact of climate change on the length of the growing season and carbon cycles in terrestrial ecosystems. However, large uncertainties in present phenology models make accurate assessment of the beginning of the growing season (BGS) a challenge. In this study, based on the satellite-based phenology product (i.e. the V005 MODIS Land Cover Dynamics (MCD12Q2) product), we calibrated four phenology models, compared their relative strength to predict vegetation phenology; and assessed the spatial pattern and interannual variability of BGS in the Northern Hemisphere. The results indicated that parameter calibration significantly influences the models' accuracy. All models showed good performance in cool regions but poor performance in warm regions. On average, they explained about 67% (the Growing Degree Day model), 79% (the Biome-BGC phenology model), 73% (the Number of Growing Days model) and 68% (the Number of Chilling Days-Growing Degree Day model) of the BGS variations over the Northern Hemisphere. There were substantial differences in BGS simulations among the four phenology models. Overall, the Biome-BGC phenology model performed best in predicting the BGS, and showed low biases in most boreal and cool regions. Compared with the other three models, the two-phase phenology model (NCD-GDD) showed the lowest correlation and largest biases with the MODIS phenology product, although it could catch the interannual variations well for some vegetation types. Our study highlights the need for further improvements by integrating the effects of water availability, especially for plants growing in low latitudes, and the physiological adaptation of plants into phenology models.

  8. Growing season carries stronger contributions to albedo dynamics on the Tibetan plateau.

    Directory of Open Access Journals (Sweden)

    Li Tian

    Full Text Available The Tibetan Plateau has experienced higher-than-global-average climate warming in recent decades, resulting in many significant changes in ecosystem structure and function. Among them is albedo, which bridges the causes and consequences of land surface processes and climate. The plateau is covered by snow/ice and vegetation in the non-growing season (nGS and growing season (GS, respectively. Based on the MODIS products, we investigated snow/ice cover and vegetation greenness in relation to the spatiotemporal changes of albedo on the Tibetan Plateau from 2000 through 2013. A synchronous relationship was found between the change in GSNDVI and GSalbedo over time and across the Tibetan landscapes. We found that the annual average albedo had a decreasing trend, but that the albedo had slightly increased during the nGS and decreased during the GS. Across the landscapes, the nGSalbedo fluctuated in a synchronous pattern with snow/ice cover. Temporally, monthly snow/ice coverage also had a high correspondence with albedo, except in April and October. We detected clear dependencies of albedo on elevation. With the rise in altitude, the nGSalbedo decreased below 4000 m, but increased for elevations of 4500-5500 m. Above 5500 m, the nGSalbedo decreased, which was in accordance with the decreased amount of snow/ice coverage and the increased soil moisture on the plateau. More importantly, the decreasing albedo in the most recent decade appeared to be caused primarily by lowered growing season albedo.

  9. 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)

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

    Science.gov (United States)

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

    2014-07-01

    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.

  11. Variations of Mercury Concentrations in American Beech Foliage over a Growing Season

    Science.gov (United States)

    Stinson, I.; Tsui, M. T. K.; Chow, A. T.

    2017-12-01

    Accumulation of atmospheric gaseous mercury (Hg) in foliage is well known, however, a small fraction of Hg always exists as highly bioavailable methylmercury (MeHg) in foliage but the source of MeHg in foliage is unknown. Recent studies suggested in-vivo Hg methylation in foliage while others suggested external inputs (e.g., precipitation) as sources of MeHg in foliage. This study assesses the accumulation of total Hg and MeHg within the foliage of a small sample set of American Beech trees, one of the common tree species in the east coast and the study site is located within the campus of University of North Carolina - Greensboro, over the growing season in 2017 (spring, summer, and fall). In addition, this study evaluates the Hg concentrations in foliage as related to other physiological parameters (e.g., stomatal density, leaf area, chlorophyll, and carbon/nitrogen content) and the changes in environmental characteristics (e.g., sunlight) over the growing season. For this investigation, five American Beech trees with varying characteristics (height, age, and location) were selected. On a biweekly basis, starting late April 2017, foliage samples were collected and composited from different positions on each tree. For the samples processed to date, our results indicate that total Hg accumulation is occurring for all five trees with an initial mean value of 5.79 ng/g, increasing to a mean value of 13.9 ng/g over a ten-week period. Coincidentally, there has been a similar increase in chlorophyll (a+b) concentrations for the foliage, and there is a strong, positive relationship between chlorophyll and total-Hg concentrations. However, we found no relationships between total Hg concentrations and stomatal density of foliage or carbon/nitrogen content. This study is still ongoing and will continue through the end of the growing season in 2017. Additionally, from the same sample sets, besides total Hg analysis and other ancillary parameters in foliage, MeHg analysis

  12. Efficiency of nitrogen fertilizer applied at corn sowing in contrasting growing seasons in Paraguay

    Directory of Open Access Journals (Sweden)

    Telmo Jorge Carneiro Amado

    2013-12-01

    Full Text Available In order to select soil management practices that increase the nitrogen-use efficiency (NUE in agro-ecosystems, the different indices of agronomic fertilizer efficiency must be evaluated under varied weather conditions. This study assessed the NUE indices in no-till corn in southern Paraguay. Nitrogen fertilizer rates from 0 to 180 kg ha-1 were applied in a single application at corn sowing and the crop response investigated in two growing seasons (2010 and 2011. The experimental design was a randomized block with three replications. Based on the data of grain yield, dry matter, and N uptake, the following fertilizer indices were assessed: agronomic N-use efficiency (ANE, apparent N recovery efficiency (NRE, N physiological efficiency (NPE, partial factor productivity (PFP, and partial nutrient balance (PNB. The weather conditions varied largely during the experimental period; the rainfall distribution was favorable for crop growth in the first season and unfavorable in the second. The PFP and ANE indices, as expected, decreased with increasing N fertilizer rates. A general analysis of the N fertilizer indices in the first season showed that the maximum rate (180 kg ha-1 obtained the highest corn yield and also optimized the efficiency of NPE, NRE and ANE. In the second season, under water stress, the most efficient N fertilizer rate (60 kg ha-1 was three times lower than in the first season, indicating a strong influence of weather conditions on NUE. Considering that weather instability is typical for southern Paraguay, anticipated full N fertilization at corn sowing is not recommended due the temporal variability of the optimum N fertilizer rate needed to achieve high ANE.

  13. Season of testing and its effect on feed intake and efficiency in growing beef cattle.

    Science.gov (United States)

    Mujibi, F D N; Moore, S S; Nkrumah, D J; Wang, Z; Basarab, J A

    2010-12-01

    This study sought to assess whether residual feed intake (RFI) calculated by regressing feed intake (DMI) on growth rate (ADG) and metabolic mid-BW in 3 different ways led to similar estimates of genetic parameters and variance components for young growing cattle tested for feed intake in fall and winter seasons. A total of 378 beef steers in 5 cohorts were fed a typical high energy feedlot diet and had free-choice access to feed and water. Feed intake data were collected in fall or winter seasons. Climate data were obtained from the University of Alberta Kinsella meteorological station and Vikings AGCM station. Individual animal RFI was obtained by either fitting a regression model to each test group separately (RFI(C)), fitting a regression model to pooled data consisting of all cohorts but including test group as a fixed effect (RFI(O)), or fitting a regression to pooled data with test group as a fixed effect but within seasonal (fall-winter or winter-spring) groups (RFI(S)). Two animal models (M1 and M2) that differed by the inclusion of fixed effects of test group or season, respectively, were used to evaluate RFI measurements. Feed intake was correlated with air temperature, relative humidity, solar radiation, and wind speed (-0.26, 0.23, 0.30, -0.14 for fall-winter and 0.31, -0.04, 0.14, 0.16 for winter-spring, respectively), but the nature and magnitude of the correlations were different for the 2 seasons. Single trait direct heritability, model likelihood, direct genetic variance, and EBV accuracy estimates were greatest for RFI(C) and least for RFI(O) for both M1 and M2 models. A significant genetic correlation was also observed between RFI(O) and ADG, but not for RFI(C) and RFI(S). Including a season effect (M2) in the genetic evaluation of RFI(O) resulted in the smallest heritability, model LogL, EBV accuracy, and largest residual variance estimates. These results, though not conclusive, suggest a possible effect of seasonality on feed intake and thus

  14. Topoclimate effects on growing season length and montane conifer growth in complex terrain

    Science.gov (United States)

    Barnard, D. M.; Barnard, H. R.; Molotch, N. P.

    2017-05-01

    Spatial variability in the topoclimate-driven linkage between forest phenology and tree growth in complex terrain is poorly understood, limiting our understanding of how ecosystems function as a whole. To characterize the influence of topoclimate on phenology and growth, we determined the start, end, and length of the growing season (GSstart, GSend, and GSL, respectively) using the correlation between transpiration and evaporative demand, measured with sapflow. We then compared these metrics with stem relative basal area increment (relative BAI) at seven sites among elevation and aspects in a Colorado montane forest. As elevation increased, we found shorter GSL (-50 d km-1) due to later GSstart (40 d km-1) and earlier GSend (-10 d km-1). North-facing sites had a 21 d shorter GSL than south-facing sites at similar elevations (i.e. equal to 200 m elevation difference on a given aspect). Growing season length was positively correlated with relative BAI, explaining 83% of the variance. This study shows that topography exerts strong environmental controls on GSL and thus forest growth. Given the climate-related dependencies of these controls, the results presented here have important implications for ecosystem responses to changes in climate and highlight the need for improved phenology representation in complex terrain.

  15. Growing season length as a key factor of cumulative net ecosystem exchange over the pine forest ecosystems in Europe

    Czech Academy of Sciences Publication Activity Database

    Danielewska, A.; Urbaniak, M.; Olejnik, Janusz

    2015-01-01

    Roč. 29, č. 2 (2015), s. 129-135 ISSN 0236-8722 Institutional support: RVO:67179843 Keywords : forest * carbon dioxide * eddy covariance * growing season length Subject RIV: EH - Ecology, Behaviour Impact factor: 1.067, year: 2015

  16. Variability of thermal and precipitation conditions in the growing season in Poland in the years 1966-2015

    Science.gov (United States)

    Tomczyk, Arkadiusz M.; Szyga-Pluta, Katarzyna

    2018-03-01

    The aim of the study was to identify the thermal and precipitation conditions and their changes in the growing season in Poland in the years 1966-2015. Data on average daily air temperature and daily precipitation totals for 30 stations from the period of 1966-2015 were used. The data were obtained from the collections of the Institute of Meteorology and Water Management—National Research Institute. The growing season was defined as the period of average daily air temperature ≥ 5 °C. The mathematical formulas proposed by Gumiński (1948) were used to determine its start and end dates. In the growing season in Poland in the years 1966-2015, there were more significant changes in the thermal conditions than there were in the precipitation conditions. In terms of long-term trends over the study period, thermal conditions during the growing season are characterised by an increase in mean air temperature, an increase in the sum of air temperatures and an increasing occurrence of seasons classified as above-normal seasons. Precipitation conditions of the growing season show large temporal and spatial variations in precipitation and a predominance of normal conditions. The changes in precipitation were not statistically significant, except for Świnoujście.

  17. 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

  18. Growing season carbon dioxide exchange in flooded non-mulching and non-flooded mulching cotton.

    Science.gov (United States)

    Li, Zhi-guo; Zhang, Run-hua; Wang, Xiu-jun; Chen, Fang; Tian, Chang-yan

    2012-01-01

    There is much interest in the role that agricultural practices might play in sequestering carbon to help offset rising atmospheric CO₂ concentrations. However, limited information exists regarding the potential for increased carbon sequestration of different management strategies. The objective of this study was to quantify and contrast carbon dioxide exchange in traditional non-mulching with flooding irrigation (TF) and plastic film mulching with drip irrigation (PM) cotton (Gossypium hirsutum L.) fields in northwest China. Net primary productivity (NPP), soil heterotrophic respiration (R(h)) and net ecosystem productivity (NEP) were measured during the growing seasons in 2009 and 2010. As compared with TF, PM significantly increased the aboveground and belowground biomass and the NPP (340 g C m⁻² season⁻¹) of cotton, and decreased the R(h) (89 g C m⁻² season⁻¹) (pmulching practices is an effective way to increase carbon sequestration in the short term in cotton systems of arid areas.

  19. Forest phenology and a warmer climate - Growing season extension in relation to climatic provenance

    Energy Technology Data Exchange (ETDEWEB)

    Gunderson, Carla A [ORNL; Edwards, Nelson T [ORNL; Walker, Ashley V [ORNL; O' Hara, Keiran H [ORNL; Campion, Christina M [ORNL; Hanson, Paul J [ORNL

    2012-01-01

    Predicting forest responses to warming climates relies on assumptions about niche and temperature sensitivity that remain largely untested. Observational studies have related current and historical temperatures to phenological shifts, but experimental evidence is sparse, particularly for autumn responses. A five-year field experiment exposed four deciduous forest species from contrasting climates (Liquidambar styraciflua, Quercus rubra, Populus grandidentata, and Betula alleghaniensis) to air temperatures 2 and 4 C above ambient controls. Impacts of year-round warming on bud burst (BB), senescence and abscission were evaluated in relation to thermal provenance. Leaves emerged earlier in all species, by an average of 6-9 days at +2 and +4 C. Magnitude of advance varied with species and year, but was larger for the first 2 C increment than the second. The effect of warming increased with early BB, favoring Liquidambar, from the warmest climate, but even BB in northern species advanced, despite temperatures well beyond those of the realized niche. Treatment differences in BB were poorly explained by temperature sums, which increased with treatment. In autumn, chlorophyll was retained an average of 4 and 7 days longer in +2 and +4 C treatments, and abscission delayed by 8 and 13 days. Species differences in autumn responses were marginally significant. Growing seasons in the warmer atmospheres were 6 - 28 days longer, with the least impact in Quercus. Results are compared with a 16-year record of canopy onset and offset in a nearby upland deciduous forest, where BB showed similar responsiveness to spring temperatures (2 - 4 days C-1). Offset dates in the stand tracked August-September temperatures, except when late summer drought caused premature senescence. The common garden-like experimental approach provides evidence that warming alone extends the growing season, at both ends, even if stand-level impacts are complicated by other environmental factors.

  20. Effects of urban green infrastructure (UGI) on local outdoor microclimate during the growing season.

    Science.gov (United States)

    Wang, Yafei; Bakker, Frank; de Groot, Rudolf; Wörtche, Heinrich; Leemans, Rik

    2015-12-01

    This study analyzed how the variations of plant area index (PAI) and weather conditions alter the influence of urban green infrastructure (UGI) on microclimate. To observe how diverse UGIs affect the ambient microclimate through the seasons, microclimatic data were measured during the growing season at five sites in a local urban area in The Netherlands. Site A was located in an open space; sites B, C, and D were covered by different types and configurations of green infrastructure (grove, a single deciduous tree, and street trees, respectively); and site E was adjacent to buildings to study the effects of their façades on microclimate. Hemispherical photography and globe thermometers were used to quantify PAI and thermal comfort at both shaded and unshaded locations. The results showed that groves with high tree density (site B) have the strongest effect on microclimate conditions. Monthly variations in the differences of mean radiant temperature (∆Tmrt) between shaded and unshaded areas followed the same pattern as the PAI. Linear regression showed a significant positive correlation between PAI and ∆Tmrt. The difference of daily average air temperature (∆T a ) between shaded and unshaded areas was also positively correlated to PAI, but with a slope coefficient below the measurement accuracy (±0.5 °C). This study showed that weather conditions can significantly impact the effectiveness of UGI in regulating microclimate. The results of this study can support the development of appropriate UGI measures to enhance thermal comfort in urban areas.

  1. Trends in temperature and growing season length in idaho-usa during the past few decades

    Directory of Open Access Journals (Sweden)

    Carlos Antonio Costa dos Santos

    2015-12-01

    Full Text Available ABSTRACT This study attempts to provide new information on seasonal and annual trends, on a regional scale, using records of daily air temperature over Idaho, USA, through the analysis of the Growing Season Length (GSL, and maximum and minimum air temperature data from multiple stations in the region, as well as, to obtain the temporal correlation between the daily air temperature and Sea Surface Temperature (SST indices. The analyses were conducted using long-term and high quality data sets for 35 meteorological stations for the period between 1970 and 2006. The results suggest that both daily maximum and minimum temperatures had increasing trends, but the minimum air temperature is increasing faster than the maximum air temperature. On average, the GSL has increased by 7.5 days/decade during the period 1970-2006, associated with increasing temperatures. Trends in regional air temperature and their indication of climate change are of interest to Idaho and the rest of the world. The trends obtained herein corroborate with the general idea that during the last century the globe has warmed.

  2. Divergent scaling of respiration rates to nitrogen and phosphorus across four woody seedlings between different growing seasons.

    Science.gov (United States)

    Fan, Ruirui; Sun, Jun; Yang, Fuchun; Li, Man; Zheng, Yuan; Zhong, Quanlin; Cheng, Dongliang

    2017-11-01

    Empirical studies indicate that the exponents governing the scaling of plant respiration rates ( R ) with respect to biomass ( M ) numerically vary between three-fourth for adult plants and 1.0 for seedlings and saplings and are affected by nitrogen (N) and phosphorus (P) content. However, whether the scaling of R with respect to M (or N and P) varies among different phylogenetic groups (e.g., gymnosperms vs. angiosperms) or during the growing and dormant seasons remains unclear. We measured the whole-plant R and M , and N and P content of the seedlings of four woody species during the growing season (early October) and the dormant season (January). The data show that (i) the scaling exponents of R versus M , R versus N, and R versus P differed significantly among the four species, but (ii), not between the growing and dormant seasons for each of the four species, although (iii) the normalization constants governing the scaling relationships were numerically greater for the growing season compared to the dormant season. In addition, (iv) the scaling exponents of R versus M , R versus N, and R versus P were numerically larger for the two angiosperm species compared to those of the two gymnosperm species, (v) the interspecific scaling exponents for the four species were greater during the growing season than in the dormant season, and (vi), interspecifically, P scaled nearly isometric with N content. Those findings indicate that the metabolic scaling relationships among R , M , N, and P manifest seasonal variation and differ between angiosperm and gymnosperm species, that is, there is no single, canonical scaling exponent for the seedlings of woody species.

  3. 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. ;

  4. Seasonal variation in chemistry, but not morphology, in roots of Quercus robur growing in different soil types.

    Science.gov (United States)

    Zadworny, Marcin; McCormack, M Luke; Rawlik, Katarzyna; Jagodziński, Andrzej M

    2015-06-01

    Patterns of root traits among different root orders and their variation across seasons are of considerable importance for soil resource acquisition and partitioning in forest ecosystems. We evaluated whether morphological, anatomical and biochemical traits varied among root orders of Quercus robur (L.) sampled across spring, summer and fall seasons and growing in two different soil types with contrasting site fertility. We found no consistent differences in root diameter and specific root length in relation to soil type or growing season. There was, however, a strong seasonal variation in patterns of nitrogen (N) concentration among root orders. During spring and summer, N concentration was highest in the most distal, absorptive portion of the root system. At the end of the growing season, we observed a sharp decline in the N concentration of these lower-order, absorptive roots and an increase in N concentration of the higher-order, transport roots. The specific mechanisms driving the seasonally changing N concentration remain unclear but are likely related to different functions of lower-order roots for absorption and higher-order roots for structure and storage. Future work should identify how common the observed seasonal changes in N concentration are across species and determine what specific environmental cues plants or roots use to trigger shifts in resource allocation within the root branching hierarchy. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Impact of mulches and growing season on indicator bacteria survival during lettuce cultivation.

    Science.gov (United States)

    Xu, Aixia; Buchanan, Robert L; Micallef, Shirley A

    2016-05-02

    In fresh produce production, the use of mulches as ground cover to retain moisture and control weeds is a common agricultural practice, but the influence that various mulches have on enteric pathogen survival and dispersal is unknown. The goal of this study was to assess the impact of different mulching methods on the survival of soil and epiphytic fecal indicator bacteria on organically grown lettuce during different growing seasons. Organically managed lettuce, cultivated with various ground covers--polyethylene plastic, corn-based biodegradable plastic, paper and straw mulch--and bare ground as a no-mulch control, was overhead inoculated with manure-contaminated water containing known levels of generic Escherichia coli and Enterococcus spp. Leaves and soil samples were collected at intervals over a two week period on days 0, 1, 3, 5, 7, 10 and 14, and quantitatively assessed for E. coli, fecal coliforms and Enterococcus spp. Data were analyzed using mixed models with repeated measures and an exponential decline with asymptote survival model. Indicator bacterial concentrations in the lettuce phyllosphere decreased over time under all treatments, with more rapid E. coli declines in the fall than in the spring (pplastic mulches in all trials, and higher enterococci levels under straw in fall 2014 (p<0.05). This study demonstrates that mulches used in lettuce production may impact the fate of enteric bacteria in soil or on lettuce, most likely in relation to soil moisture retention, and other weather-related factors, such as temperature and rainfall. The data suggest that the time between exposure to a source of enteric bacteria and harvesting of the crop is season dependent, which has implications for determining best harvest times. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Environmental Influences on the Growing Season Duration and Ripening of Diverse Miscanthus Germplasm Grown in Six Countries

    Directory of Open Access Journals (Sweden)

    Christopher Nunn

    2017-05-01

    Full Text Available The development of models to predict yield potential and quality of a Miscanthus crop must consider climatic limitations and the duration of growing season. As a biomass crop, yield and quality are impacted by the timing of plant developmental transitions such as flowering and senescence. Growth models are available for the commercially grown clone Miscanthus x giganteus (Mxg, but breeding programs have been working to expand the germplasm available, including development of interspecies hybrids. The aim of this study was to assess the performance of diverse germplasm beyond the range of environments considered suitable for a Miscanthus crop to be grown. To achieve this, six field sites were planted as part of the EU OPTIMISC project in 2012 in a longitudinal gradient from West to East: Wales—Aberystwyth, Netherlands—Wageningen, Stuttgart—Germany, Ukraine—Potash, Turkey—Adana, and Russia—Moscow. Each field trial contained three replicated plots of the same 15 Miscanthus germplasm types. Through the 2014 growing season, phenotypic traits were measured to determine the timing of developmental stages key to ripening; the tradeoff between growth (yield and quality (biomass ash and moisture content. The hottest site (Adana showed an accelerated growing season, with emergence, flowering and senescence occurring before the other sites. However, the highest yields were produced at Potash, where emergence was delayed by frost and the growing season was shortest. Flowering triggers varied with species and only in Mxg was strongly linked to accumulated thermal time. Our results show that a prolonged growing season is not essential to achieve high yields if climatic conditions are favorable and in regions where the growing season is bordered by frost, delaying harvest can improve quality of the harvested biomass.

  7. Factors Affecting the Content of Ergosterol and Zearalenone in Selected Grass Species at the End of the Growing Season

    OpenAIRE

    Jiří Skládanka; Vlastimil Dohnal; Petr Doležal; Alena Ježková; Ladislav Zeman

    2009-01-01

    The objective of the study was to assess the safety of forage prepared from selected grass species by means of the analysis of ergosterol and zearalenone. Graminaceous plants studied at the end of their growing season were Festulolium, Dactylis glomerata and Arrhenatherum elatius. Other indicators assessed were the content of ergosterol and zearalenone during the autumn and the intensity of grassland use in the summer season as related to the studied contents of metabolites. Grasslands were h...

  8. Simulation of soil water balance and partitioning of evapotranspiration of maize grown in two growing seasons in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Viviane Schons de Ávila

    2017-11-01

    Full Text Available ABSTRACT: The objective of this study was to simulate the variation of the available soil water during maize crop growth, in two different sowing times (first and second growing season, using a drip irrigation system. The treatments consisted of different irrigation strategies (full to deficit. The SIMDualKc simulation model was used to determine the daily soil water balance and crop evapotranspiration using the dual crop coefficient approach. Soil, climate, crop and irrigation parameters were used as input data. Two experiments were carried out in a rainout shelter composed of two metallic structures (16x10m in the city of Santa Maria, Rio Grande do Sul, Brazil, during 2010/11 (second crop, season 1 and 2011/12 (first crop, season 2 growing seasons, under no-tillage system. The simulations showed that all the irrigation management strategies used in season 2 resulted in soil water deficit, while only two strategies showed deficit in season 1. Results showed good agreement between observed and simulated soil water data, with an R2 ranging from 0.86 to 0.99 and the root mean square error ranging from 2.7 to 5.6% of the total available water for seasons 1 and 2, respectively. The observed results of water balance showed that maize grown in season 2 presented higher water consumption compared to season 1, due to the higher atmospheric demand of season 2. The SIMDualKc model allowed the partitioning of crop evapotranspiration into soil evaporation and crop transpiration, demonstrating that the vegetative growth subperiod presented the greatest differences between the two seasons compared to the others growth phases.

  9. Quantifying the growing season dynamics and phenology of a boreal black spruce wildfire chronosequence: Coupling field measurements with MODIS

    Science.gov (United States)

    Serbin, S. P.; Ahl, D. E.; Gower, S. T.

    2007-12-01

    The boreal forest is the second largest forested biome and the vast area and large carbon stores in the soil makes these forests important to the global carbon, water and energy cycles. Analysis of global coverage, coarse resolution satellite Vegetation Index (VI) data have provided considerable information on the seasonal cycles of vegetation in the mid-to high-latitudes, including the boreal forest, with evidence of an increase in the magnitude of vegetation greenness and a lengthening of the active growing season, which has been attributed to climate warming. However, boreal forests are prone to extensive wildfire disturbance that influence canopy dynamics (i.e. species composition, LAI, and phenology) and separating the direct affect of warming from the indirect affect of increased wildfire frequency on the patterns of boreal phenology and seasonal greeness requires further analysis coupled to ground measurements. In this research we address the need for detailed information on the growing season dynamics and phenological patterns of boreal vegetation. We evaluate whether MODIS reflectance data can resolve small inter-annual variations in canopy phenology and growing season dynamics of boreal forests. We quantified the seasonality and inter-annual differences of the overstory and understory vegetation by optically measuring the LAI and light harvesting potential (FPAR) during the 2004-2006 growing seasons. An automated continuously operating system is used to monitor growing season PAR transmittance. We focused on a boreal wildfire chronosequence of sites comprising a range of forest ages (1-154 years since fire) to quantify the differences in vegetation dynamics and phenology between the deciduous/mixed and coniferous forests. The spatial and temporal characteristics of LAI / FPAR within the chronosequence were examined by comparing both the in situ measurements and the relevant MODIS products. A statistical curve fitting procedure is used to derive the key

  10. Effects of mid-season frost and elevated growing season temperature on stomatal conductance and specific xylem conductivity of the arctic shrub, Salix pulchra

    Energy Technology Data Exchange (ETDEWEB)

    Gorsuch, D. M.; Oberbauer, S. F. [Florida International Univ., Dept. of Biological Sciences, Miami, FL (United States)

    2002-10-01

    It is hypothesized that because deciduous plants have a growth season limited in length and also have generally larger conduit volumes, they are more likely to be injured by freeze-thaw induced cavitation during the growing season. To test this hypothesis, the deciduous arctic shrub, Salix pulchra, was grown in simulated Alaskan summer temperatures and at five degrees C above the ambient simulation in controlled environments. Specific hydraulic conductivity and leaf stomatal conductance were measured in plants grown at both temperatures before and after freeze treatment simulating a mid-season frost. Before freeze treatment specific hydraulic conductivity was 2.5 times higher and stomatal conductance was 1.3 times higher in plants grown at elevated temperature. After freeze treatment reduction in hydraulic conductivity and stomatal conductance was 3.5 and 1.8 times higher in the plants grown at the higher temperature than plants grown at ambient temperature. Plants grown at the higher temperature also had larger vessel diameters and higher vessel densities than ambient-grown plants. These results suggest that higher growing season temperatures will make arctic deciduous shrubs more susceptible to frost damage. The implication of these results for plant growth in the arctic tundra is that while climate warming favours plants with larger vessels and higher specific xylem conductivity over plants with lower values, this competitive advantage may be lost if there is an increase in the risk of frost during the growing season. 43 refs., 5 figs.

  11. Impacts of temperature extremes on European vegetation during the growing season

    Science.gov (United States)

    Baumbach, Lukas; Siegmund, Jonatan F.; Mittermeier, Magdalena; Donner, Reik V.

    2017-11-01

    Temperature is a key factor controlling plant growth and vitality in the temperate climates of the mid-latitudes like in vast parts of the European continent. Beyond the effect of average conditions, the timings and magnitudes of temperature extremes play a particularly crucial role, which needs to be better understood in the context of projected future rises in the frequency and/or intensity of such events. In this work, we employ event coincidence analysis (ECA) to quantify the likelihood of simultaneous occurrences of extremes in daytime land surface temperature anomalies (LSTAD) and the normalized difference vegetation index (NDVI). We perform this analysis for entire Europe based upon remote sensing data, differentiating between three periods corresponding to different stages of plant development during the growing season. In addition, we analyze the typical elevation and land cover type of the regions showing significantly large event coincidences rates to identify the most severely affected vegetation types. Our results reveal distinct spatio-temporal impact patterns in terms of extraordinarily large co-occurrence rates between several combinations of temperature and NDVI extremes. Croplands are among the most frequently affected land cover types, while elevation is found to have only a minor effect on the spatial distribution of corresponding extreme weather impacts. These findings provide important insights into the vulnerability of European terrestrial ecosystems to extreme temperature events and demonstrate how event-based statistics like ECA can provide a valuable perspective on environmental nexuses.

  12. High methane emissions from restored Norway spruce swamps in southern Finland over one growing season

    Directory of Open Access Journals (Sweden)

    M. Koskinen

    2016-02-01

    Full Text Available Forestry-drained peatlands in the boreal region are currently undergoing restoration in order to bring these ecosystems closer to their natural (undrained state. Drainage affects the methane (CH4 dynamics of a peatland, often changing sites from CH4 sources to sinks. Successful restoration of a peatland would include restoration of not only the surface vegetation and hydrology, but also the microbial populations and thus CH4 dynamics. As a pilot study, CH4 emissions were measured on two pristine, two drained and three restored boreal spruce swamps in southern Finland for one growing season. Restoration was successful in the sense that the water table level in the restored sites was significantly higher than in the drained sites, but it was also slightly higher than in the pristine sites. The restored sites were surprisingly large sources of CH4 (mean emissions of 52.84 mg CH4 m-2 d-1, contrasting with both the pristine (1.51 mg CH4 m-2 d-1 and the drained sites (2.09 mg CH4 m-2 d-1. More research is needed to assess whether the high CH4 emissions observed in this study are representative of restored spruce mires in general.

  13. Infiltration and Soil Loss Changes during the Growing Season under Ploughing and Conservation Tillage

    Directory of Open Access Journals (Sweden)

    Gergely Jakab

    2017-09-01

    Full Text Available Decreased water retention and increased runoff and soil loss are of special importance concerning soil degradation of hilly crop fields. In this study, plots under ploughing (conventional tillage (PT and conservation tillage (CT; 15 years were compared. Rainfall simulation on 6 m2 plots was applied to determine infiltration and soil loss during the growing season. Results were compared with those measured from 1200 m2 plots exposed to natural rainfalls in 2016. Infiltration was always higher under CT than PT, whereas the highest infiltration was measured under the cover crop condition. Infiltration under seedbed and stubble resulted in uncertainties, which suggests that natural pore formation can be more effective at improving soil drainage potential than can temporary improvements created by soil tillage operations. Soil erodibility was higher under PT for each soil status; however, the seedbed condition triggered the highest values. For CT, soil loss volume was only a function of runoff volume at both scales. Contrarily, on PT plots, some extreme precipitation events triggered extremely high soil loss owing to linear erosion, which meant no direct connection existed between the scales. Improved soil conditions due to conservation practice are more important for decreasing soil loss than the better surface conditions.

  14. Effect of average growing season temperature on seedling germination, survival and growth in jack pine (Pinus banksiana Lamb.)

    Science.gov (United States)

    A. David; E. Humenberger

    2017-01-01

    Because jack pine (Pinus banksiana Lamb.) is serotinous, it retains multiple years of cones until environmental conditions are favorable for releasing seed. These cones, which contain seed cohorts that developed under a variety of growing seasons, can be accurately aged using bud scale scars on twigs and branches. By calculating the average daily...

  15. THE INFLUENCE OF WEATHER CONDITIONS OF EASTERN POLAND ON SWEET CORN YIELDS AND LENGTH OF GROWING SEASON

    Directory of Open Access Journals (Sweden)

    Robert Rosa

    2016-09-01

    Full Text Available The aim of the study was to determine the effect of weather components (air temperature, precipitation on the growth, yield and the length of the growing season of sweet corn cultivated in eastern Poland. The results come from a field experiment conducted in 2006–2011. Weather conditions in the successive years of the study significantly modified the yield of ears, weight and number of formatted ears, high of plants and the length of the growing season of sweet corn. Good yielding of sweet corn favoured years with moderate air temperatures in July and uniform distribution of precipitation during the growing season. The highest yield of ears was found in 2011, the lowest in the very difficult in terms of weather 2006. The shortest growing season was characterized corn grown in the years 2006 and 2010 with the high air temperatures in July and August, the longest in the years 2009 and 2011, in which the temperatures in the period June-August were the lowest of all the years of research. Irrespective of the year of study, cv ‘Sheba F1’ was formatted eras with higher weight than cv ‘Sweet Nugget F1’.

  16. Video data of flowers, fruitlets, and fruit in apple trees during the 2017 growing season at USDA-ARS-AFRS

    Science.gov (United States)

    This record contains videos of apple trees acquired from a ground vehicle throughout the growing season at the USDA-ARS, Appalachian Fruit Research Station. Research in precision management methods in orchard crops revolve around locating objects of interest, namely flowers, fruitlets, and fruit, a...

  17. The Effects of Climate Change on Variability of the Growing Seasons in the Elbe River Lowland, Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Potopová, V.; Zahradníček, Pavel; Türkot, L.; Štěpánek, Petr; Soukup, J.

    2015-01-01

    Roč. 2015, č. 546920 (2015), s. 546920 ISSN 1687-9309 R&D Projects: GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : Central Europe * extremes * climate change * growing seasons * Elbe River Lowland Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.107, year: 2015

  18. Changes in ultraviolet-B and visible optical properties and absorbing pigment concentrations in pecan leaves during a growing season

    Science.gov (United States)

    Yadong Qi; Shuju Bai; Gordon M. Heisler

    2003-01-01

    UV-B (280-320 nm) and visible (400-760 nm) spectral reflectance, transmittance, and absorptance; chlorophyll content; UV-B absorbing compound concentration; and leaf thickness were measured for pecan (Carya illinoensis) leaves over a growing season (April-October). Leaf samples were collected monthly from a pecan plantation located on the Southern...

  19. Effects of application of corn straw on soil microbial community structure during the maize growing season.

    Science.gov (United States)

    Lu, Ping; Lin, Yin-Hua; Yang, Zhong-Qi; Xu, Yan-Peng; Tan, Fei; Jia, Xu-Dong; Wang, Miao; Xu, De-Rong; Wang, Xi-Zhuo

    2015-01-01

    This study investigated the influence of corn straw application on soil microbial communities and the relationship between such communities and soil properties in black soil. The crop used in this study was maize (Zea mays L.). The five treatments consisted of applying a gradient (50, 100, 150, and 200%) of shattered corn straw residue to the soil. Soil samples were taken from May through September during the 2012 maize growing season. The microbial community structure was determined using phospholipid fatty acid (PLFA) analysis. Our results revealed that the application of corn straw influenced the soil properties and increased the soil organic carbon and total nitrogen. Applying corn straw to fields also influenced the variation in soil microbial biomass and community composition, which is consistent with the variations found in soil total nitrogen (TN) and soil respiration (SR). However, the soil carbon-to-nitrogen ratio had no effect on soil microbial communities. The abundance of PLFAs, TN, and SR was higher in C1.5 than those in other treatments, suggesting that the soil properties and soil microbial community composition were affected positively by the application of corn straw to black soil. A Principal Component Analysis indicated that soil microbial communities were different in the straw decomposition processes. Moreover, the soil microbial communities from C1.5 were significantly different from those of CK (p soil and significant variations in the ratio of monounsaturated-to-branched fatty acids with different straw treatments that correlated with SR (p soil properties and soil microbial communities and that these properties affect these communities. The individual PLFA signatures were sensitive indicators that reflected the changes in the soil environment condition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Underestimated effects of low temperature during early growing season on carbon sequestration of a subtropical coniferous plantation

    Directory of Open Access Journals (Sweden)

    W.-J. Zhang

    2011-06-01

    Full Text Available The impact of air temperature in early growing season on the carbon sequestration of a subtropical coniferous plantation was discussed through analyzing the eddy flux observations at Qianyanzhou (QYZ site in southern China from 2003 to 2008. This site experienced two cold early growing seasons (with temperature anomalies of 2–5 °C in 2005 and 2008, and a severe summer drought in 2003.
    Results indicated that the low air temperature from January to March was the major factor controlling the inter-annual variations in net carbon uptake at this site, rather than the previously thought summer drought. The accumulative air temperature from January to February showed high correlation (R2=0.970, p<0.001 with the annual net ecosystem production (NEP. This was due to the controls of early-month temperature on the plant phenology developing and the growing season length at this subtropical site. The cold spring greatly shortened the growing season length and therefore reduced the carbon uptake period. The eddy flux observations showed a carbon loss of 4.04 g C m−2 per growing-season day at this coniferous forest site. On the other hand, the summer drought also reduced the net carbon uptake strength because the photosynthesis was more sensitive to water deficit stress than the ecosystem respiration. However, the impact of summer drought occurred within a relatively shorter period and the carbon sequestration went back to the normal level once the drought was relieved.

  1. Likely changes in growing season indices under a climate change scenario for crop production in South Africa

    Science.gov (United States)

    Ambrosino, C.; Chandler, R. E.; Todd, M. C.

    2011-12-01

    Agriculture is still the major source of income and livelihood for most of South Africa's population, and cereals and grains are among the country's most important crops. In particular, the largest locally produced field crop and the most important source of carbohydrates in South Africa is maize (Zea mays L.). As well as extensive monoculture, maize production also dominates the smallholder farming system in areas such as the Limpopo District in north-east South Africa. It is therefore critical to understand the year-to-year changes in the planting season and rainfall characteristics in order to introduce management decision and mitigation measures in the agricultural sector (e.g. planting of drought-resistant crops or the choice between long and short-season cultivars). Indeed, one of the strategies that may be easily introduced by farmers is shifting the crop planting dates to adjust to changes in the rainfall regimes. The study presented here aims to characterise the inter-annual growing season variability through the use of 7 indices derived from daily precipitation, considered the most critical factor in rain-fed agriculture, having an impact on maize production. A statistical model is developed to generate daily rainfall sequences for the study area driven by large scale climate controls. An independent validation period is chosen to evaluate the performance of the statistical model in the rainfall generation process. Onset, length and cessation of the growing season, as well as indices representing the length of the mean and maximum dry spell during the season are derived from the area average daily simulated precipitation values. The fraction of rainy days and total precipitation during the growing season are also calculated. Finally, the projected change of the growing season indices between two investigated periods in the 20th and 21st centuries is investigated under a climate change scenario (a1b; e.g.: Fig.1). The outputs of this study may be used to

  2. Diurnal patterns of gas-exchange and metabolic pools in tundra plants during three phases of the arctic growing season.

    Science.gov (United States)

    Patankar, Rajit; Mortazavi, Behzad; Oberbauer, Steven F; Starr, Gregory

    2013-02-01

    Arctic tundra plant communities are subject to a short growing season that is the primary period in which carbon is sequestered for growth and survival. This period is often characterized by 24-h photoperiods for several months a year. To compensate for the short growing season tundra plants may extend their carbon uptake capacity on a diurnal basis, but whether this is true remains unknown. Here, we examined in situ diurnal patterns of physiological activity and foliar metabolites during the early, mid, and late growing season in seven arctic species under light-saturated conditions. We found clear diurnal patterns in photosynthesis and respiration, with midday peaks and midnight lulls indicative of circadian regulation. Diurnal patterns in foliar metabolite concentrations were less distinct between the species and across seasons, suggesting that metabolic pools are likely governed by proximate external factors. This understanding of diurnal physiology will also enhance the parameterization of process-based models, which will aid in better predicting future carbon dynamics for the tundra. This becomes even more critical considering the rapid changes that are occurring circumpolarly that are altering plant community structure, function, and ultimately regional and global carbon budgets.

  3. Diurnal patterns of gas-exchange and metabolic pools in tundra plants during three phases of the arctic growing season

    Science.gov (United States)

    Patankar, Rajit; Mortazavi, Behzad; Oberbauer, Steven F; Starr, Gregory

    2013-01-01

    Arctic tundra plant communities are subject to a short growing season that is the primary period in which carbon is sequestered for growth and survival. This period is often characterized by 24-h photoperiods for several months a year. To compensate for the short growing season tundra plants may extend their carbon uptake capacity on a diurnal basis, but whether this is true remains unknown. Here, we examined in situ diurnal patterns of physiological activity and foliar metabolites during the early, mid, and late growing season in seven arctic species under light-saturated conditions. We found clear diurnal patterns in photosynthesis and respiration, with midday peaks and midnight lulls indicative of circadian regulation. Diurnal patterns in foliar metabolite concentrations were less distinct between the species and across seasons, suggesting that metabolic pools are likely governed by proximate external factors. This understanding of diurnal physiology will also enhance the parameterization of process-based models, which will aid in better predicting future carbon dynamics for the tundra. This becomes even more critical considering the rapid changes that are occurring circumpolarly that are altering plant community structure, function, and ultimately regional and global carbon budgets. PMID:23467719

  4. Leaf dynamics of Festulolium and Dactylis glomerata L. at the end of the growing season

    Directory of Open Access Journals (Sweden)

    Jiří Skládanka

    2008-01-01

    Full Text Available The paper is focused on the assessment of leaf extension rate (LER, leaf appearance rate (LAR and leaf senescence rate (LSR in the Festulolium (Festuca arundinacea Schreb. × Lolium multiflorum Lam. and in the Dactylis glomerata L. at the end of the growing season from the end of September to the beginning of December. In summer, the swards were used for a single cut (beginning of June or for a double cut (beginning of June and end of July. Measurements were made in three periods from 14 Sept. to 11 Oct., from 11 Oct. to 29 Oct., and from 29 Oct. to 6 Dec. In the first period, LER was higher in Dactylis glomerata L. (3.770 mm tiller−1 d−1 than in Festulolium (2.376 mm tiller−1 d−1. In the second and third period, LER was higher in Festulolium (0.859 resp. 0.271 mm tiller−1 d−1 than in Dactylis glomerata L. (0.694, resp. 0.199 mm tiller−1 d−1. LAR values measured in Festulolium in the studied pe­riods were 0.277 leaf tiller−1 d−1, 0.079 leaf tiller−1 d−1 and 0.038 leaf tiller−1 d−1 and LAR values of Dactylis glomerata L. were 0.225 leaf tiller−1 d−1, 0.054 leaf tiller−1 d−1 and 0.027 leaf tiller−1 d−1. In the course of the whole pe­riod of study, LSR showed the highest values in Dactylis glomerata L. (7.869 mm til­ler−1 d−1, 5.947 mm til­ler−1 d−1 and 4.757 mm tiller−1 d−1 while the LSR values of Festulolium were lower (2.904 mm tiller−1 d−1, 2.375 mm tiller−1 d−1 and 1.205 mm tiller−1 d−1. The influence of both the species and the period of measurement on the LER, LAR and LSR values was statistically highly significant (P < 0.01 to very highly significant (P < 0.001. The interaction between the species and the period of measurement was very highly significant (P < 0.001 in the LER characteristic. The influence of the intensity of sward use in summer on the LSR values was very highly significant (P < 0.001, too.

  5. Divergent scaling of respiration rates to nitrogen and phosphorus across four woody seedlings between different growing seasons

    OpenAIRE

    Fan, Ruirui; Sun, Jun; Yang, Fuchun; Li, Man; Zheng, Yuan; Zhong, Quanlin; Cheng, Dongliang

    2017-01-01

    Abstract Empirical studies indicate that the exponents governing the scaling of plant respiration rates (R) with respect to biomass (M) numerically vary between three‐fourth for adult plants and 1.0 for seedlings and saplings and are affected by nitrogen (N) and phosphorus (P) content. However, whether the scaling of R with respect to M (or N and P) varies among different phylogenetic groups (e.g., gymnosperms vs. angiosperms) or during the growing and dormant seasons remains unclear. We meas...

  6. Grazing exclusion increases soil CO2 emission during the growing season in alpine meadows on the Tibetan Plateau

    Science.gov (United States)

    Guo, Na; Wang, Aidong; Allan Degen, A.; Deng, Bin; Shang, Zhanhuan; Ding, Luming; Long, Ruijun

    2018-02-01

    Soil CO2 emission is a key part of the terrestrial carbon cycle. Grazing exclusion by fencing is often considered a beneficial grassland management option to restore degraded grassland, but its effect on soil CO2 emission on the northeastern Tibetan Plateau is equivocal and is the subject of this study. Using a closed static chamber, we measured diurnal soil CO2 flux weekly from July, 2008, to April, 2009, in response to grazing and grazing exclusion in the alpine meadow and alpine shrub meadow. Concomitantly, soil temperature was measured at depths of 5 cm, 10 cm, 15 cm and 20 cm with digital temperature sensors. It emerged that: 1) non-grazed grasslands emitted more soil CO2 than grazed grasslands over the growing season; 2) the alpine shrub meadow emitted more soil CO2 than the alpine meadow; the annual cumulative soil CO2 emissions of alpine meadow and alpine shrub meadow were 241.5-326.5 g C/m2 and 429.0-512.5 g C/m2, respectively; 3) seasonal patterns were evident with more soil CO2 flux in the growing than in the non-growing season; and 4) the diurnal soil CO2 flux exhibited a single peak across all sampling sites. In addition, soil CO2 flux was correlated positively with soil temperature at 5 cm, but not at the other depths. We concluded that grazing exclusion enhanced soil CO2 emission over the growing season, and decreased carbon sequestration of alpine meadow and alpine shrub meadow on the northeastern Tibetan Plateau. Since an increase in soil temperature increased soil CO2 flux, global warming could have an effect on soil CO2 emission in the future.

  7. Identification of proteins from cambium tissues of the chinese white poplar (populus tomentosa) sampled during the growing season

    International Nuclear Information System (INIS)

    Xie, J.; Liu, S.; Qi, Q.; Hou, Y.

    2014-01-01

    Various protein extraction methods have been used to investigate Chinese white poplar (Populus tomentosa) proteomics. However, extracting and characterizing proteins from woody plants remains a challenge. Two-dimensional gel electrophoresis is a powerful, widely used method for the analysis of complex protein mixtures extracted from biological samples. The technique separates mixtures of proteins along two dimensions, by isoelectric point and molecular weight, and can resolve thousands of different proteins. Here, we report a new application of two-dimensional gel electrophoresis to investigate the proteomics of P. tomentosa cambium tissues over the course of a growing season. Of three protein extraction methods that we compared (the Tris-phenol method, trichloroacetic acid-acetone method, and trichloroacetic acid-acetone-phenol method), trichloroacetic acid-acetone was the most efficient approach for protein extraction from cambium tissues of P. tomentosa. After extraction, the proteins were separated using two-dimensional gel electrophoresis. The protein quantities of six spots changed over the course of the growing season from February to July. Five spots were identified using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry, and the sixth spot was identified by liquid chromatography-mass spectrometry. The proteins included enolase, class Ia chitinase, and four unnamed proteins. Our results show the best approach to proteomics in P. tomentosa and reveal trends in protein activities during a growing season in this tree species. (author)

  8. Effects of dormant and growing season burning on surface fuels and potential fire behavior in northern Florida longleaf pine (Pinus palustris) flatwoods

    Science.gov (United States)

    James B. Cronan; Clinton S. Wright; Maria Petrova

    2015-01-01

    Prescribed fire is widely used to manage fuels in high-frequency, low-severity fire regimes including pine flatwoods of the southeastern USA where prescribed burning during the growing season (the frost-free period during the calendar year) has become more common in recent decades. Growing season prescribed fires address ecological management objectives that focus on...

  9. Phenology and species determine growing-season albedo increase at the altitudinal limit of shrub growth in the sub-Arctic.

    Science.gov (United States)

    Williamson, Scott N; Barrio, Isabel C; Hik, David S; Gamon, John A

    2016-11-01

    Arctic warming is resulting in reduced snow cover and increased shrub growth, both of which have been associated with altered land surface-atmospheric feedback processes involving sensible heat flux, ground heat flux and biogeochemical cycling. Using field measurements, we show that two common Arctic shrub species (Betula glandulosa and Salix pulchra), which are largely responsible for shrub encroachment in tundra, differed markedly in albedo and that albedo of both species increased as growing season progressed when measured at their altitudinal limit. A moveable apparatus was used to repeatedly measure albedo at six precise spots during the summer of 2012, and resampled in 2013. Contrary to the generally accepted view of shrub-covered areas having low albedo in tundra, full-canopy prostrate B. glandulosa had almost the highest albedo of all surfaces measured during the peak of the growing season. The higher midsummer albedo is also evident in localized MODIS albedo aggregated from 2000 to 2013, which displays a similar increase in growing-season albedo. Using our field measurements, we show the ensemble summer increase in tundra albedo counteracts the generalized effect of earlier spring snow melt on surface energy balance by approximately 40%. This summer increase in albedo, when viewed in absolute values, is as large as the difference between the forest and tundra transition. These results indicate that near future (albedo related to Arctic vegetation change are unlikely to be particularly large and might constitute a negative feedback to climate warming in certain circumstances. Future efforts to calculate energy budgets and a sensible heating feedback in the Arctic will require more detailed information about the relative abundance of different ground cover types, particularly shrub species and their respective growth forms and phenology. © 2016 John Wiley & Sons Ltd.

  10. Positive feedback of greenhouse gas balances to warming is determined by non-growing season emissions in an alpine meadow

    Science.gov (United States)

    Niu, S.; Wang, J.; Quan, Q.; Chen, W.; Wen, X.; Yu, G.

    2017-12-01

    Large uncertainties exist in the sources and sinks of greenhouse gases (CO2, CH4, N2O) in response to climate warming and human activity. So far, numerous previous studies have evaluated the CO2 budget, but little attention has paid to CH4 and N2O budgets and the concurrent balance of these three gases in combination, especially in the non-growing season. Here, we synthesized eddy covariance measurement with the automatic chamber measurements of CO2, CH4, and N2O exposed to three levels of temperature treatments (ambient, +1.5 °C, +2.5 °C) and two disturbance treatments (ummowing, mowing) in an alpine meadow on the Tibetan Plateau. We have found that warming caused increase in CH4 uptake and decrease in N2O emission offset little of the enhancement in CO2 emission, triggering a positive feedback to climate warming. Warming switches the ecosystem from a net sink (-17 ± 14 g CO2-eq m-2 yr-1) in the control to a net source of greenhouse gases of 94 ± 36 gCO2-eq m-2 yr-1 in the plots with +1.5 °C warming treatment, and 177 ± 6 gCO2-eq m-2 yr-1 in the plots with +2.5 °C warming treatment. The changes in the non-growing season balance, rather than those in the growing season, dominate the warming responses of annual greehouse gas balance. And this is not changed by mowing. The dominant role of responses of winter greenhouse gas balance in the positive feedback of ecosystem to climate warming highlights that greenhouse gas balance in cold season has to be considered when assessing climate-carbon cycle feedback.

  11. Cambial activity in dry and rainy season on branches from woody species growing in Brazilian Cerrado

    Science.gov (United States)

    Carmen R. Marcati; Silvia R. Machado; Diego Sotto Podadera; Natalia O. Totti de Lara; Fabio Bosio; Alex C. Wiedenhoeft

    2016-01-01

    Seasonal cambial activity was investigated in one- to three-year-old branch modules (branch constructional units) of ten woody species from cerrado sensu stricto, a savanna-like ecosystem, of southernBrazil. Relationships between cambial activity and environmental factors (precipitation, temperature,day length) and leaf production were tested using...

  12. Longer growing seasons and warm summers boost Rhododendron ferrugineum L. growth in the Taillefer massif (French Alps)

    Science.gov (United States)

    Francon, Loïc; Corona, Christophe; Roussel, Erwan; Lopez Saez, Jerome; Stoffel, Markus

    2017-04-01

    Rhododendron ferrugineum L. is an important and widespread dwarf shrub species growing in high-elevation, alpine environments of the Western European Alps. As such, it is likely to offer unique opportunities which would allow pushing current dendrochronological networks into extreme environments and way beyond the upper survival limit of trees. Given that different species of the same genus have been successfully used in tree-ring investigations, notably in the Himalayas where Rhododendron sp. has proven to be a reliable climate proxy, this study aims at (i) evaluating the dendroclimatological potential of the widely distributed R. ferrugineum and at (ii) determining the major limiting climate factor driving species growth and the formation of rings. To this end, 154 cross-sections from 36 R. ferrugineum individuals have been sampled above local treelines and at elevations comprised between 1800 and 2100 m asl on NW-facing slopes of the Taillefer massif (French Alps). We illustrate a 195-year-long standard chronology based on growth-ring records selected from 24 individuals, and document that the series is well-replicated for almost one century (1920-2015) with an Expressed Population Signal (EPS) >0.85. Analysis using partial and seasonal correlation functions further highlight that growth of Rhododendron is governed by temperatures during the growing season (May-July), with increasingly higher air temperatures favoring larger ring widths, a phenomenon which is well known from dwarf shrubs growing in circum-arctic tundra ecosystems. Similarly, the negative effect of January-February precipitation on radial growth of R. ferrugineum, rarely observed in the Arctic, is interpreted as a result of reduced growing seasons following snowy winters. We conclude that the strong and unequivocal signals recorded in the fairly long R. ferrugineum chronologies presented here can indeed be used for climate-growth studies as well as for the reconstruction of climatic fluctuations

  13. Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season

    Science.gov (United States)

    Bachy, Aurélie; Aubinet, Marc; Schoon, Niels; Amelynck, Crist; Bodson, Bernard; Moureaux, Christine; Heinesch, Bernard

    2016-04-01

    Although maize is the second most important crop worldwide, and the most important C4 crop, no study on biogenic volatile organic compounds (BVOCs) has yet been conducted on this crop at ecosystem scale and over a whole growing season. This has led to large uncertainties in cropland BVOC emission estimations. This paper seeks to fill this gap by presenting, for the first time, BVOC fluxes measured in a maize field at ecosystem scale (using the disjunct eddy covariance by mass scanning technique) over a whole growing season in Belgium. The maize field emitted mainly methanol, although exchanges were bi-directional. The second most exchanged compound was acetic acid, which was taken up mainly in the growing season. Bi-directional exchanges of acetaldehyde, acetone and other oxygenated VOCs also occurred, whereas the terpenes, benzene and toluene exchanges were small, albeit significant. Surprisingly, BVOC exchanges were of the same order of magnitude on bare soil and on well developed vegetation, suggesting that soil is a major BVOC reservoir in agricultural ecosystems. Quantitatively, the maize BVOC emissions observed were lower than those reported in other maize, crops and grasses studies. The standard emission factors (SEFs) estimated in this study (231 ± 19 µg m-2 h-1 for methanol, 8 ± 5 µg m-2 h-1 for isoprene and 4 ± 6 µg m-2 h-1 for monoterpenes) were also much lower than those currently used by models for C4 crops, particularly for terpenes. These results suggest that maize fields are small BVOC exchangers in north-western Europe, with a lower BVOC emission impact than that modelled for growing C4 crops in this part of the world. They also reveal the high variability in BVOC exchanges across world regions for maize and suggest that SEFs should be estimated for each region separately.

  14. Prediction models for assessing anthocyanins in grape berries by fluorescence sensors: Dependence on cultivar, site and growing season.

    Science.gov (United States)

    Pinelli, Patrizia; Romani, Annalisa; Fierini, Elisa; Agati, Giovanni

    2018-04-01

    Fluorescence sensors are useful tools for the non-destructive assessment of grape berry anthocyanins. The Multiplex (Mx) sensor here studied provides two anthocyanin indices: ANTH R  = log(1/Chl-fluorescence_R) and ANTH RG  = log(Chl-fluorescence_R/Chl-fluorescence_G), based on the chlorophyll (Chl) fluorescence excited with red (R) and green (G) light. These indices were calibrated against wet chemistry. The dependence of anthocyanin prediction models on cultivar, season and site was studied on four cultivars in two Italian regions during three consecutive years. The 2010 global model (all cultivars at both growing sites) gave relative prediction errors on anthocyanin content less than 14.1% (ANTH R ) and 19.0% (ANTH RG ). The ANTH RG was independent of season, maintaining a relative error of about 20% in both 2011 and 2012. In field applications of the calibrated Mx, it showed its ability to detect inter-plot and inter-season differences on both growing sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Land–Atmosphere Exchange of Water and Heat in the Arid Mountainous Grasslands of Central Asia during the Growing Season

    Directory of Open Access Journals (Sweden)

    Xiaotao Huang

    2017-09-01

    Full Text Available Arid grassland ecosystems are widely distributed across Central Asia. However, there is a lack of research and observations of the land–atmosphere exchange of water and heat in the arid grasslands in this region, particularly over complex surfaces. In this study, systematic observations were conducted from 2013 to 2015 using an HL20 Bowen ratio and TDR300 and WatchDog1400 systems to determine the characteristics of these processes during the growing season (April–October of the arid mountainous grasslands of this region. (1 The latent heat flux (Le was lower than the sensible heat flux (He overall, and a small transient decrease in Le was observed before its daytime maximum; daily comparative variations in both fluxes were closely related to vegetation growth. (2 Evapotranspiration (ET showed substantial variation across different years, seasons and months, and monthly variations in ET were closely related to vegetation growth. Water condensation (Q was low and relatively stable. Relatively high levels of soil water were measured in spring followed by a decreasing trend. The land–atmosphere exchange of water and heat during the growing season in this region was closely associated with phenology, available precipitation and terrain. This study provides data support for the scientific management of arid mountainous grasslands.

  16. 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.

  17. Landscape controls on the timing of spring, autumn, and growing season length in mid-Atlantic forests

    Science.gov (United States)

    Elmore, A.J.; Guinn, S.M.; Minsley, B.J.; Richardson, A.D.

    2012-01-01

    The timing of spring leaf development, trajectories of summer leaf area, and the timing of autumn senescence have profound impacts to the water, carbon, and energy balance of ecosystems, and are likely influenced by global climate change. Limited field-based and remote-sensing observations have suggested complex spatial patterns related to geographic features that influence climate. However, much of this variability occurs at spatial scales that inhibit a detailed understanding of even the dominant drivers. Recognizing these limitations, we used nonlinear inverse modeling of medium-resolution remote sensing data, organized by day of year, to explore the influence of climate-related landscape factors on the timing of spring and autumn leaf-area trajectories in mid-Atlantic, USA forests. We also examined the extent to which declining summer greenness (greendown) degrades the precision and accuracy of observations of autumn offset of greenness. Of the dominant drivers of landscape phenology, elevation was the strongest, explaining up to 70% of the spatial variation in the onset of greenness. Urban land cover was second in importance, influencing spring onset and autumn offset to a distance of 32 km from large cities. Distance to tidal water also influenced phenological timing, but only within ~5 km of shorelines. Additionally, we observed that (i) growing season length unexpectedly increases with increasing elevation at elevations below 275 m; (ii) along gradients in urban land cover, timing of autumn offset has a stronger effect on growing season length than does timing of spring onset; and (iii) summer greendown introduces bias and uncertainty into observations of the autumn offset of greenness. These results demonstrate the power of medium grain analyses of landscape-scale phenology for understanding environmental controls on growing season length, and predicting how these might be affected by climate change.

  18. 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

  19. Impact of Faba Bean-Seed Rhizobial Inoculation on Microbial Activity in the Rhizosphere Soil during Growing Season

    Directory of Open Access Journals (Sweden)

    Anna Siczek

    2016-05-01

    Full Text Available Inoculation of legume seeds with Rhizobium affects soil microbial community and processes, especially in the rhizosphere. This study aimed at assessing the effect of Rhizobium inoculation on microbial activity in the faba bean rhizosphere during the growing season in a field experiment on a Haplic Luvisol derived from loess. Faba bean (Vicia faba L. seeds were non-inoculated (NI or inoculated (I with Rhizobium leguminosarum bv. viciae and sown. The rhizosphere soil was analyzed for the enzymatic activities of dehydrogenases, urease, protease and acid phosphomonoesterase, and functional diversity (catabolic potential using the Average Well Color Development, Shannon-Weaver, and Richness indices following the community level physiological profiling from Biolog EcoPlate™. The analyses were done on three occasions corresponding to the growth stages of: 5–6 leaf, flowering, and pod formation. The enzymatic activities were higher in I than NI (p < 0.05 throughout the growing season. However, none of the functional diversity indices differed significantly under both treatments, regardless of the growth stage. This work showed that the functional diversity of the microbial communities was a less sensitive tool than enzyme activities in assessment of rhizobial inoculation effects on rhizosphere microbial activity.

  20. Controls for multi-scale temporal variation in ecosystem methane exchange during the growing season of a permanently inundated fen

    Science.gov (United States)

    Koebsch, Franziska; Jurasinski, Gerald; Koch, Marian; Hofmann, Joachim; Glatzel, Stephan

    2014-05-01

    Temperature and phenology trigger seasonal variation of CH4 emissions in many ecosystems. However, ecosystem CH4 exchange varies also considerably on smaller temporal scales such as days or weeks. Indeed, we are aware of many processes that control CH4 emissions on the local soil-plant-atmosphere continuum, but their interaction on ecosystem level is not well understood yet. We used a quasi-continuous Eddy Covariance CH4 flux time series and wavelet analysis to describe the temporal variation of ecosystem CH4 exchange within the growing season of a permanently inundated temperate fen. Moreover, we assigned time scale-specific controls and investigated whether their impact changes during the course of the growing season. Water/soil temperature correlated with ecosystem CH4 exchange at time scales of 6-11 and 22 days which exceeds the time scales that are typically associated with the passage of weather fronts. The low response time might be due to the high heat capacity of the water column. On a daily scale, shear-induced turbulence (presented by friction velocity) and plant activity (presented by canopy photosynthesis) caused a diurnal variation of ecosystem CH4 exchange with peak time around noon. However, this pattern was apparent only at the beginning of the growing season (April/May). In the following, convective mixing of the water column (presented by the water temperature gradient) gradually gained importance and caused high night-time CH4 emissions, thereby levelling off the diurnal CH4 emission pattern. Our study highlights the need for multi-scale approaches that consider the non-stationarity of the underlying processes to adequately describe the complexity of ecosystem CH4 exchange. Moreover, we show that CH4 release processes such as convective mixing of the water column which has been mainly known from aquatic ecosystems until recently (Godwin et al. 2013), might be also of importance in shallowly flooded terrestrial ecosystems. Citation: Godwin CM, Mc

  1. Growing season boundary layer climate and surface exchanges in a subarctic lichen woodland

    Science.gov (United States)

    Fitzjarrald, David R.; Moore, Kathleen E.

    1994-01-01

    Between June and August 1990, observations were made at two surface micrometeorological towers near Schefferville Quebec (54 deg 52 min N, 66 deg 40.5 min W), one in a fen and one in the subarctic lichen woodland, and at four surface climatological stations. Data from these surface stations were supplemented by regular radiosonde launches. Supporting measurements of radiative components and soil temperatures allowed heat and moisture balances to be obtained at two sites. The overall surface meteorological experiment design and results of micrometeorological observations made on a 30-m tower in the lichen woodland are presented here. Seasonal variation in the heat and water vapor transport characteristics illustrate the marked effect of the late summer climatological shift in air mass type. During the first half of the summer, average valley sidewalls only 100 m high are sufficient to channel winds along the valley in the entire convective boundary layer. Channeling effects at the surface, known for some time at the long-term climate station in Schefferville, are observed both at ridge top and in the valley, possibly the response of the flow to the NW-SE orientation of valleys in the region. Diurnal surface temperature amplitude at ridge top (approximately equal to 10 C) was found to be half that observed in the valley. Relatively large differences in precipitation among these stations and the climatological station at Schefferville airport were observed and attributed to the local topography. Eddy correlation observations of the heat, moisture and momentum transports were obtained from a 30-m tower above a sparse (approximately equal to 616 stems/ha) black spruce lichen woodland. Properties of the turbulent surface boundary layer agree well with previous wind tunnel studies over idealized rough surfaces. Daytime Bowen ratios of 2.5-3 are larger than those reported in previous studies. Surface layer flux data quality was assessed by looking at the surface layer heat

  2. Estimating Water Footprints of Vegetable Crops: Influence of Growing Season, Solar Radiation Data and Functional Unit

    Directory of Open Access Journals (Sweden)

    Betsie le Roux

    2016-10-01

    Full Text Available Water footprint (WF accounting as proposed by the Water Footprint Network (WFN can potentially provide important information for water resource management, especially in water scarce countries relying on irrigation to help meet their food requirements. However, calculating accurate WFs of short-season vegetable crops such as carrots, cabbage, beetroot, broccoli and lettuce presented some challenges. Planting dates and inter-annual weather conditions impact WF results. Joining weather datasets of just rainfall, minimum and maximum temperature with ones that include solar radiation and wind-speed affected crop model estimates and WF results. The functional unit selected can also have a major impact on results. For example, WFs according to the WFN approach do not account for crop residues used for other purposes, like composting and animal feed. Using yields in dry matter rather than fresh mass also impacts WF metrics, making comparisons difficult. To overcome this, using the nutritional value of crops as a functional unit can connect water use more directly to potential benefits derived from different crops and allow more straightforward comparisons. Grey WFs based on nitrogen only disregards water pollution caused by phosphates, pesticides and salinization. Poor understanding of the fate of nitrogen complicates estimation of nitrogen loads into the aquifer.

  3. Climatic warming above the Arctic Circle: are there trends in timing and length of the thermal growing season in Murmansk Region (Russia) between 1951 and 2012?

    Science.gov (United States)

    Blinova, Ilona; Chmielewski, Frank-Michael

    2015-06-01

    Anomalies in the timing of the thermal growing season have become obvious in the NE part of Fennoscandia since 2000. They are in accordance with climatic changes reported for Europe and Fennoscandia. The actual length of the growing season reached 120 days on average, onset on 30 May and ending on 27 September (1981-2010). Shifts in the timing of the growing season and its mean prolongation by 18.5 days/62a are demonstrated for Murmansk Region (1951-2012). In this period, the onset of the growing season advanced by 7.1 days/62a, while the end was extended by 11.4 days/62a. The delay in the end of the growing season is similar to the entire Fennoscandian pattern but it has not been detected in the rest of Europe. The regional pattern of climatic regimes in Murmansk Region remained stable in comparison with earlier climatic maps (1971). However, the actual shifts in the timing of the growing season were more pronounced in colder (oceanic and mountainous) parts. Recent climatic trends could influence the retreat of the tundra zone and changes in the forest line. Losses of tundra biodiversity and enrichment of the northern taiga by southern species could be expected from present climatic trends.

  4. Injury to apical meristem of cranberry by Dasineura oxycoccana (Diptera: Cecidomyiidae) reduces production of floral-units in the next growing season.

    Science.gov (United States)

    Tewari, S; Buonaccorsi, J P; Averill, A L

    2012-08-01

    Cranberry tipworm, Dasineura oxycoccana Johnson (a gall-making fly), disrupts normal growth of cranberry (Vaccinium macrocarpon Aiton) by injuring the apical meristem of shoots or uprights. The impact of larval feeding injury on reproductive parameters of cranberry was determined, from one growing season to next, at upright (Maine and Massachusetts, 2008-2009) and plot levels (Massachusetts, 2009-2010 and 2010-2011). We also estimated the proportions of uprights injured because of tipworm feeding at several cranberry production sites (Massachusetts and Maine) and the proportions of uprights that produced flowers and fruits in the next growing season. Tipworm-injured uprights tagged at the end of the growing season did not produce floral-units (following year) across sites in both Massachusetts and Maine. There was significant variation among the sampled sites in the proportions of tipworm-injured uprights and also in the proportions of uprights with flowers in the next growing season (Massachusetts and Maine). A trend was apparent wherein sites with higher tipworm injury levels had relatively lower flowering proportions in the next growing season. However, sites in Massachusetts did not differ in the proportions of uprights that set fruit and in a replicated study, significant reduction in tipworm injury at plot level (using insecticide) did not impact flower and fruit production in the next growing season.

  5. Leaf ontogeny dominates the seasonal exchange of volatile organic compounds (VOC) in a SRC-poplar plantation during an entire growing season

    Science.gov (United States)

    Brilli, Federico; Gioli, Beniamino; Fares, Silvano; Zenone, Terenzio; Zona, Donatella; Gielen, Bert; Loreto, Francesco; Janssens, Ivan; Ceulemans, Reinhart

    2015-04-01

    The declining cost of many renewable energy technologies and changes in the prices of fossil fuels have recently encouraged governments policies to subsidize the use of biomass as a sustainable source of energy. Deciduous poplars (Populus spp.) trees are often selected for biomass production in short rotation coppiced (SRC) for their high CO2 photosynthetic assimilation rates and their capacity to develop dense canopies with high values of leaf area index (LAI). So far, observations and projections of seasonal variations of many VOC fluxes has been limited to strong isoprenoids emitting evergreen ecosystems such tropical and Mediterranean forests as well as Citrus and oil palm plantation, all having constant values of LAI. We run a long-term field campaign where the exchange of VOC, together with CO2 and water vapor was monitored during an entire growing season (June - November, 2012) above a SRC-based poplar plantation. Our results confirmed that isoprene and methanol were the most abundant fluxes emitted, accounting for more than 90% of the total carbon released in form of VOC. However, Northern climates characterized by fresh summertime temperatures and recurring precipitations favored poplar growth while inhibiting the development of isoprene emission that resulted in only 0.7% of the net ecosystem carbon exchange (NEE). Besides, measurements of a multitude of VOC fluxes by PTR-TOF-MS showed bi-directional exchange of oxygenated-VOC (OVOC) such as: formaldehyde, acetaldehyde, acetone, isoprene oxidation products (iox, namely MVK, MAC and MEK) as well as ethanol and formic acid. The application of Self Organizing Maps to visualize the relationship between the full time-series of many VOC fluxes and the observed seasonal variations of environmental, physiological and structural parameters proved the most abundant isoprene ad methanol fluxes to occur mainly on the hottest days under mid-high light intensities when also NEE and evapotraspiration reached the highest

  6. Seasonal thermal energy storage program. Progress report, January 1980-December 1980

    Energy Technology Data Exchange (ETDEWEB)

    Minor, J.E.

    1981-05-01

    The objectives of the Seasonal Thermal Energy Storage (STES) Program is to demonstrate the economic storage and retrieval of energy on a seasonal basis, using heat or cold available from waste sources or other sources during a surplus period to reduce peak period demand, reduce electric utilities peaking problems, and contribute to the establishment of favorable economics for district heating and cooling systems for commercialization of the technology. Aquifers, ponds, earth, and lakes have potential for seasonal storage. The initial thrust of the STES Program is toward utilization of ground-water systems (aquifers) for thermal energy storage. Program plans for meeting these objectives, the development of demonstration programs, and progress in assessing the technical, economic, legal, and environmental impacts of thermal energy storage are described. (LCL)

  7. Downscaling 250-m MODIS growing season NDVI based on multiple-date landsat images and data mining approaches

    Science.gov (United States)

    Gu, Yingxin; Wylie, Bruce K.

    2015-01-01

    The satellite-derived growing season time-integrated Normalized Difference Vegetation Index (GSN) has been used as a proxy for vegetation biomass productivity. The 250-m GSN data estimated from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors have been used for terrestrial ecosystem modeling and monitoring. High temporal resolution with a wide range of wavelengths make the MODIS land surface products robust and reliable. The long-term 30-m Landsat data provide spatial detailed information for characterizing human-scale processes and have been used for land cover and land change studies. The main goal of this study is to combine 250-m MODIS GSN and 30-m Landsat observations to generate a quality-improved high spatial resolution (30-m) GSN database. A rule-based piecewise regression GSN model based on MODIS and Landsat data was developed. Results show a strong correlation between predicted GSN and actual GSN (r = 0.97, average error = 0.026). The most important Landsat variables in the GSN model are Normalized Difference Vegetation Indices (NDVIs) in May and August. The derived MODIS-Landsat-based 30-m GSN map provides biophysical information for moderate-scale ecological features. This multiple sensor study retains the detailed seasonal dynamic information captured by MODIS and leverages the high-resolution information from Landsat, which will be useful for regional ecosystem studies.

  8. Communities of arbuscular mycorrhizal fungi detected in forest soil are spatially heterogeneous but do not vary throughout the growing season.

    Science.gov (United States)

    Davison, John; Öpik, Maarja; Zobel, Martin; Vasar, Martti; Metsis, Madis; Moora, Mari

    2012-01-01

    Despite the important ecosystem role played by arbuscular mycorrhizal fungi (AMF), little is known about spatial and temporal variation in soil AMF communities. We used pyrosequencing to characterise AMF communities in soil samples (n = 44) from a natural forest ecosystem. Fungal taxa were identified by BLAST matching of reads against the MaarjAM database of AMF SSU rRNA gene diversity. Sub-sampling within our dataset and experimental shortening of a set of long reads indicated that our approaches to taxonomic identification and diversity analysis were robust to variations in pyrosequencing read length and numbers of reads per sample. Different forest plots (each 10 × 10 m and separated from one another by 30 m) contained significantly different soil AMF communities, and the pairwise similarity of communities decreased with distance up to 50 m. However, there were no significant changes in community composition between different time points in the growing season (May-September). Spatial structure in soil AMF communities may be related to the heterogeneous vegetation of the natural forest study system, while the temporal stability of communities suggests that AMF in soil represent a fairly constant local species pool from which mycorrhizae form and disband during the season.

  9. Factors Affecting the Content of Ergosterol and Zearalenone in Selected Grass Species at the End of the Growing Season

    Directory of Open Access Journals (Sweden)

    Jiří Skládanka

    2009-01-01

    Full Text Available The objective of the study was to assess the safety of forage prepared from selected grass species by means of the analysis of ergosterol and zearalenone. Graminaceous plants studied at the end of their growing season were Festulolium, Dactylis glomerata and Arrhenatherum elatius. Other indicators assessed were the content of ergosterol and zearalenone during the autumn and the intensity of grassland use in the summer season as related to the studied contents of metabolites. Grasslands were harvested either in October, November or December. The secondary metabolites were analyzed by means of high performance liquid chromatography. At the end of the growing season, the ergosterol content was the lowest in the Festulolium forage (110.04 mg kg-1, the highest contents were observed in the Dactylis glomerata and Arrhenatherum elatius forages (145.73 mg kg-1 and 139.55 mg kg-1, respectively. The safety of Festulolium was also corroborated by the low zearalenone content (0.357 mg kg-1. On the other hand, the high ergosterol content in Arrhenatherum elatius was combined with a high content of zearalenone (1.554 mg kg-1. Although Dactylis glomerata exhibited an ergosterol content comparable with that of Arrhenatherum elatius forage, its zearalenone content was comparable to the Festulolium forage. Among the three species under study we found a significant difference (P P -1. The higher (P -1 was caused by the Arrhenatherum elatius forage. Moreover, the contents of ergosterol and zearalenone were affected (P < 0.01 also by the number of cuts in summer. The higher ergosterol content indicated a higher forage infestation by fungi and the inherent risk of the occurrence of mycotoxins. However, the high ergosterol content not always correlated with the high content of zearalenone. When cattle is grazing in winter, a higher occurrence of mycotoxins in the feed may be expected and the related damage to animal metabolism may increase the number of diseased

  10. Sensitivity of the reference evapotranspiration to key climatic variables during the growing season in the Ejina oasis northwest China.

    Science.gov (United States)

    Hou, Lan-Gong; Zou, Song-Bing; Xiao, Hong-Lang; Yang, Yong-Gang

    2013-01-01

    The standardized FAO56 Penman-Monteith model, which has been the most reasonable method in both humid and arid climatic conditions, provides reference evapotranspiration (ETo) estimates for planning and efficient use of agricultural water resources. And sensitivity analysis is important in understanding the relative importance of climatic variables to the variation of reference evapotranspiration. In this study, a non-dimensional relative sensitivity coefficient was employed to predict responses of ETo to perturbations of four climatic variables in the Ejina oasis northwest China. A 20-year historical dataset of daily air temperature, wind speed, relative humidity and daily sunshine duration in the Ejina oasis was used in the analysis. Results have shown that daily sensitivity coefficients exhibited large fluctuations during the growing season, and shortwave radiation was the most sensitive variable in general for the Ejina oasis, followed by air temperature, wind speed and relative humidity. According to this study, the response of ETo can be preferably predicted under perturbation of air temperature, wind speed, relative humidity and shortwave radiation by their sensitivity coefficients.

  11. Silvicultural options in ageing holm oak (Quercus ilex L. coppices in Gargano: results after 14 growing seasons

    Directory of Open Access Journals (Sweden)

    Scopigno D

    2008-12-01

    Full Text Available In the frame of a long-term research program concerning management of ageing holm oak coppices, results available after 14 growing seasons are reported in present paper. Experimental treatments include: A 50 standards per hectare, all of the same age; B 250 standards per hectare, all of the same age; C 140 standards per hectare, with two different ages; D conversion to high forest; E natural evolution (control. A total of 15 permanent plots were established (5 treatments x 3 replicates per treatment and the experimental design used is that of randomised blocks. Based on observations concerning seedlings and shoots development and standards growth and competitive effects, the following preliminary results may be highlighted: i recovering the traditional coppicing system with few standards per hectare represents a valid option from both ecological and shoots growth point of view; the stools, with few standards per hectare, showed a larger number of sprouts, provided with a higher average height and larger diameters; ii uneven-aged standards represent a good alternative form the points of view of both landscape impact immediately after felling operations and stand resistance to climatic damages; iii a good alternative is to apply conversion treatments to high forest, whenever their site quality allows these operations.

  12. Phosphorus interception in floodwater of paddy field during the rice-growing season in TaiHu Lake Basin

    International Nuclear Information System (INIS)

    Zhang Zhijian; Zhang Jianying; He Ruo; Wang Zhaode; Zhu Yinmei

    2007-01-01

    A field experiment located in TaiHu Lake Basin in China was conducted, by application of superphosphate or a mixture of superphosphate with manure, to elucidate the interception of P export during a typical rice growing season through 'zero-drainage water management' combined with sound irrigation, rainfall forecasting and field drying. P concentrations in floodwater rapidly declined before the first event of field drying, and subsequently tended to return to the background levels. Before the first field drying TPP was the predominant P form in floodwater on fields with no P input, DRP on plots that received superphosphate only, and DOP on plots treated with the mixture of superphosphate and manure. Thereafter TPP became the major form. No P export was found from the paddy fields, but a retention of 0.65 kg ha -1 , mainly due to soil P sorption. The results recommend the zero-drainage water management for full-scale areas for minimizing P export. - Paddy field may intercept P through innovation of irrigation-drainage management

  13. Wet and Dry Atmospheric Depositions of Inorganic Nitrogen during Plant Growing Season in the Coastal Zone of Yellow River Delta

    Directory of Open Access Journals (Sweden)

    Junbao Yu

    2014-01-01

    Full Text Available The ecological problems caused by dry and wet deposition of atmospheric nitrogen have been widespread concern in the world. In this study, wet and dry atmospheric depositions were monitored in plant growing season in the coastal zone of the Yellow River Delta (YRD using automatic sampling equipment. The results showed that SO42- and Na+ were the predominant anion and cation, respectively, in both wet and dry atmospheric depositions. The total atmospheric nitrogen deposition was ~2264.24 mg m−2, in which dry atmospheric nitrogen deposition was about 32.02%. The highest values of dry and wet atmospheric nitrogen deposition appeared in May and August, respectively. In the studied area, NO3-–N was the main nitrogen form in dry deposition, while the predominant nitrogen in wet atmospheric deposition was NH4+–N with ~56.51% of total wet atmospheric nitrogen deposition. The average monthly attribution rate of atmospheric deposition of NO3-–N and NH4+–N was ~31.38% and ~20.50% for the contents of NO3-–N and NH4+–N in 0–10 cm soil layer, respectively, suggested that the atmospheric nitrogen was one of main sources for soil nitrogen in coastal zone of the YRD.

  14. [Temporal and spatial change of climate resources and meteorological disasters under climate change during winter crop growing season in Guangdong Province, China.

    Science.gov (United States)

    Wang, Hua; Chen, Hui Hua; Tang, Li Sheng; Wang, Juan Huai; Tang, Hai Yan

    2018-01-01

    Trend analysis method was applied to analyze the general variation characteristics of the climate resources and meteorological disasters of growing season of the winter planting in Guangdong before (1961-1996) and after climate warming (1997-2015). Percentile method was employed to determine thresholds for extreme cold and drought in major planting regions, and the characteristics of extreme disasters since climate warming were analyzed. The results showed that, by comparing 1997-2015 with 1961-1996, the heat value in winter growing season increased significantly. The belt with a higher heat value, where the average temperature was ≥15 ℃ and accumulated temperature was ≥2200 ℃·d, covered the main winter production regions as Shaoguan, Zhanjiang, Maoming, Huizhou, Meizhou and Guangzhou. Meanwhile, the precipitation witnessed a slight increase. The regions with precipitations of 250-350 mm included Zhanjiang, Maoming, Huizhou, Guangzhou and Meizhou. Chilling injury in the winter planting season in the regions decreased, the belt with an accumulated chilling of winter season increased significantly, the trend of chilling and drought decreased, however, the extreme disasters occurred frequently and the risks were higher in winter production areas. It was suggested that the winter planting should be closely integrated with climate resources and the occurrence law of meteorological disasters in growing season.

  15. Spatial-temporal variations in the thermal growing degree-days and season under climate warming in China during 1960-2011.

    Science.gov (United States)

    Yin, Yunhe; Deng, Haoyu; Wu, Shaohong

    2017-10-02

    Vegetation growth and phenology are largely regulated by base temperature (T b ) and thermal accumulation. Hence, the growing degree-days (GDD) and growing season (GS) calculated based on T b have primary effects on terrestrial ecosystems, and could be changed by the significant warming during the last century. By choosing 0, 5, and 10 °C, three key T b for vegetation growth, the GDD and GS in China during 1960-2011 were developed based on 536 meteorological stations with homogenized daily mean temperatures. Results show that both the GDD and GS showed positive sensitivity to the annual mean temperature. The start of the growing season (SOS) has advanced by 4.86-6.71 days, and the end of the growing season (EOS) has been delayed by 4.32-6.19 days, lengthening the GS by 10.76-11.02 days in China as a whole during 1960-2011, depending on the T b chosen. Consistently, the GDD has totally increased 218.92-339.40 °C days during the 52 years, with trends more pronounced in those based on a lower T b . The GDD increase was significant (Mann-Kendall test, p degree-days and season are expected to have great implications for biological phenology, agricultural production, and terrestrial carbon cycle in the future.

  16. Effects of fire disturbance on soil respiration in the non-growing season in a Larix gmelinii forest in the Daxing'an Mountains, China.

    Directory of Open Access Journals (Sweden)

    Tongxin Hu

    Full Text Available In boreal forests, fire is an important part of the ecosystem that greatly influences soil respiration, which in turn affects the carbon balance. Wildfire can have a significant effect on soil respiration and it depends on the fire severity and environmental factors (soil temperature and snow water equivalent after fire disturbance. In this study, we quantified post-fire soil respiration during the non-growing season (from November to April in a Larix gmelinii forest in Daxing'an Mountains of China. Soil respiration was measured in the snow-covered and snow-free conditions with varying degrees of natural burn severity forests. We found that soil respiration decreases as burn severity increases. The estimated annual C efflux also decreased with increased burn severity. Soil respiration during the non-growing season approximately accounted for 4%-5% of the annual C efflux in all site types. Soil temperature (at 5 cm depth was the predominant determinant of non-growing season soil respiration change in this area. Soil temperature and snow water equivalent could explain 73%-79% of the soil respiration variability in winter snow-covering period (November to March. Mean spring freeze-thaw cycle (FTC period (April soil respiration contributed 63% of the non-growing season C efflux. Our finding is key for understanding and predicting the potential change in the response of boreal forest ecosystems to fire disturbance under future climate change.

  17. Phenology Shifts at Start vs. End of Growing Season in Temperate Vegetation Over the Northern Hemisphere for the Period 1982-2008

    Science.gov (United States)

    Jeong, Su-Jong; Ho, Chang-Hoi; Gim, Hyeon-Ju; Brown, Molley E.

    2011-01-01

    Changes in vegetative growing seasons are dominant indicators of the dynamic response of ecosystems to climate change. Therefore, knowledge of growing seasons over the past decades is essential to predict ecosystem changes. In this study, the long-term changes in the growing seasons of temperate vegetation over the Northern Hemisphere were examined by analyzing satellite-measured normalized difference vegetation index and reanalysis temperature during 1982 2008. Results showed that the length of the growing season (LOS) increased over the analysis period; however, the role of changes at the start of the growing season (SOS) and at the end of the growing season (EOS) differed depending on the time period. On a hemispheric scale, SOS advanced by 5.2 days in the early period (1982-1999) but advanced by only 0.2 days in the later period (2000-2008). EOS was delayed by 4.3 days in the early period, and it was further delayed by another 2.3 days in the later period. The difference between SOS and EOS in the later period was due to less warming during the preseason (January-April) before SOS compared with the magnitude of warming in the preseason (June September) before EOS. At a regional scale, delayed EOS in later periods was shown. In North America, EOS was delayed by 8.1 days in the early period and delayed by another 1.3 days in the later period. In Europe, the delayed EOS by 8.2 days was more significant than the advanced SOS by 3.2 days in the later period. However, in East Asia, the overall increase in LOS during the early period was weakened in the later period. Admitting regional heterogeneity, changes in hemispheric features suggest that the longer-lasting vegetation growth in recent decades can be attributed to extended leaf senescence in autumn rather than earlier spring leaf-out. Keywords: climate change, growing season, NDVI (normalized difference vegetation index), Northern Hemisphere, phenology,

  18. Encysted cyathostomin larvae in foals - progression of stages and the effect of seasonality.

    Science.gov (United States)

    Nielsen, Martin K; Lyons, Eugene T

    2017-03-15

    Cyathostomins (small strongyles) are ubiquitous in grazing horses and are known pathogens as cause of larval cyathostominosis. As part of their life cycle, cyathostomin larvae invade the mucosal walls of the large intestines and undergo encystment. Newly ingested third stage larvae are known to undergo arrested development and this can lead to an accumulation of encysted burdens over the course of a grazing season. It is believed that the host immune system plays a significant role in triggering this arrestment. Little is known about the development and progression of larval stages in foals that are not expected to mount a pronounced immune response to ingested cyathostomin larvae. This study evaluated counts of encysted larvae measured in 37 foals. The foals were born in 2013, 2014, and 2015 into a parasitology research herd kept without anthelmintic intervention and were humanely euthanatized between 50 and 293days of age as part of an ongoing parasite transmission study. A mucosal digestion technique was performed to enumerate encysted early third stage (EL3) and late third stage/fourth stage (LL3/L4) larvae in the cecum, ventral colon and dorsal colon. Counts were analyzed statistically to evaluate the influence of foal age, sex, and seasonality on the counts. Total counts as well as LL3/L4 counts were significantly higher during the grazing season (March-November). Three defined age groups (>100, 100-200, >200days) did not have statistically different counts. Male foals had significantly higher total counts compared to females, and this has not been reported before. The study found that 41% of the recovered larvae were EL3s, but no indication of arrested development of these was observed. This indicates that cyathostomin infection in foals progresses in a manner substantially different from mature horses. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Development and Validation of a Learning Progression for Change of Seasons, Solar and Lunar Eclipses, and Moon Phases

    Science.gov (United States)

    Testa, Italo; Galano, Silvia; Leccia, Silvio; Puddu, Emanuella

    2015-01-01

    In this paper, we report about the development and validation of a learning progression about the Celestial Motion big idea. 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 about change of seasons,…

  20. Environmental and Physiographic Controls on Inter-Growing Season Variability of Carbon Dioxide and Water Vapour Fluxes in a Minerotrophic Fen

    Science.gov (United States)

    van der Kamp, G.; Sonnentag, O.; Chen, J. M.; Barr, A.; Hedstrom, N.; Granger, R.

    2008-12-01

    The interaction of fens with groundwater is spatially and temporally highly variable in response to meteorological conditions, resulting in frequent changes of groundwater fluxes in both vertical and lateral directions (flow reversals) across the mineral soil-peat boundary. However, despite the importance of the topographic and hydrogeological setting of fens, no study has been reported in the literature that explores a fen's atmospheric CO2 and energy flux densities under contrasting meteorological conditions in response to its physiographic setting. In our contribution we report four years of growing season eddy covariance and supporting measurements from the Canada Fluxnet-BERMS fen (formerly BOREAS southern peatland) in Saskatchewan, Canada. We first analyze hydrological data along two piezometer transects across the mineral soil-peat boundary with the objective of assessing changes in water table configuration and thus hydraulic gradients, indicating flow reversals, in response to dry and wet meteorological conditions. Next we quantify and compare growing season totals and diurnal and daily variations in evapotranspiration (ET) and net ecosystem exchange (NEE) and its component fluxes gross ecosystem productivity (GPP) and terrestrial ecosystem respiration (TER) to identify their controls with a major focus on water table depth. While ET growing season totals were similar (~ 310 mm) under dry and wet meteorological conditions, the CO2 sink- source strength of Sandhill fen varied substantially from carbon neutral (NEE = -2 [+-7] g C m-2 per growing season) under dry meteorological condition (2003) to a moderate CO2- sink with NEE ranging between 157 [+- 10] and 190 [+- 11] g C m-2 per growing season under wet meteorological conditions (2004, 2005, and 2006). Using a process-oriented ecosystem model, BEPS-TerrainLab, we investigate how different canopy components at Sandhill contribute to total ET and GPP, and thus water use efficiency, under dry and wet

  1. 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.

  2. Plant phenological responses to a long-term experimental extension of growing season and soil warming in the tussock tundra of Alaska.

    Science.gov (United States)

    Khorsand Rosa, Roxaneh; Oberbauer, Steven F; Starr, Gregory; Parker La Puma, Inga; Pop, Eric; Ahlquist, Lorraine; Baldwin, Tracey

    2015-12-01

    Climate warming is strongly altering the timing of season initiation and season length in the Arctic. Phenological activities are among the most sensitive plant responses to climate change and have important effects at all levels within the ecosystem. We tested the effects of two experimental treatments, extended growing season via snow removal and extended growing season combined with soil warming, on plant phenology in tussock tundra in Alaska from 1995 through 2003. We specifically monitored the responses of eight species, representing four growth forms: (i) graminoids (Carex bigellowii and Eriophorum vaginatum); (ii) evergreen shrubs (Ledum palustre, Cassiope tetragona, and Vaccinium vitis-idaea); (iii) deciduous shrubs (Betula nana and Salix pulchra); and (iv) forbs (Polygonum bistorta). Our study answered three questions: (i) Do experimental treatments affect the timing of leaf bud break, flowering, and leaf senescence? (ii) Are responses to treatments species-specific and growth form-specific? and (iii) Which environmental factors best predict timing of phenophases? Treatment significantly affected the timing of all three phenophases, although the two experimental treatments did not differ from each other. While phenological events began earlier in the experimental plots relative to the controls, duration of phenophases did not increase. The evergreen shrub, Cassiope tetragona, did not respond to either experimental treatment. While the other species did respond to experimental treatments, the total active period for these species did not increase relative to the control. Air temperature was consistently the best predictor of phenology. Our results imply that some evergreen shrubs (i.e., C. tetragona) will not capitalize on earlier favorable growing conditions, putting them at a competitive disadvantage relative to phenotypically plastic deciduous shrubs. Our findings also suggest that an early onset of the growing season as a result of decreased snow cover

  3. Are BVOC exchanges in agricultural ecosystems overestimated? Insights from fluxes measured in a maize field over a whole growing season

    Science.gov (United States)

    Bachy, Aurélie; Aubinet, Marc; Schoon, Niels; Amelynck, Crist; Bodson, Bernard; Moureaux, Christine; Heinesch, Bernard

    2016-04-01

    Maize is the most important C4 crop worldwide. It is also the second most important crop worldwide (C3 and C4 mixed), and is a dominant crop in some world regions. Therefore, it can potentially influence local climate and air quality through its exchanges of gases with the atmosphere. Among others, biogenic volatile organic compounds (BVOC) are known to influence the atmospheric composition and thereby modify greenhouse gases lifetime and pollutant formation in the atmosphere. However, so far, only two studies have dealt with BVOC exchanges from maize. Moreover, these studies were conducted on a limited range of meteorological and phenological conditions, so that the knowledge of BVOC exchanges by this crop remains poor. Here, we present the first BVOC measurement campaign performed at ecosystem-scale on a maize field during a whole growing season. It was carried out in the Lonzée Terrestrial Observatory (LTO), an ICOS site. BVOC fluxes were measured by the disjunct by mass-scanning eddy covariance technique with a proton transfer reaction mass spectrometer for BVOC mixing ratios measurements. Outstanding results are (i) BVOC exchanges from soil were as important as BVOC exchanges from maize itself; (ii) BVOC exchanges observed on our site were much lower than exchanges observed by other maize studies, even under normalized temperature and light conditions, (iii) they were also lower than those observed on other crops grown in Europe. Lastly (iv), BVOC exchanges observed on our site under standard environmental conditions, i.e., standard emission factors SEF, were much lower than those currently considered by BVOC exchange up-scaling models. From those observations, we deduced that (i) soil BVOC exchanges should be better understood and should be incorporated in terrestrial BVOC exchanges models, and that (ii) SEF for the C4 crop plant functional type cannot be evaluated at global scale but should be determined for each important agronomic and pedo-climatic region

  4. Spatial-temporal variations in the thermal growing degree-days and season under climate warming in China during 1960-2011

    Science.gov (United States)

    Yin, Yunhe; Deng, Haoyu; Wu, Shaohong

    2017-10-01

    Vegetation growth and phenology are largely regulated by base temperature (T b) and thermal accumulation. Hence, the growing degree-days (GDD) and growing season (GS) calculated based on T b have primary effects on terrestrial ecosystems, and could be changed by the significant warming during the last century. By choosing 0, 5, and 10 °C, three key T b for vegetation growth, the GDD and GS in China during 1960-2011 were developed based on 536 meteorological stations with homogenized daily mean temperatures. Results show that both the GDD and GS showed positive sensitivity to the annual mean temperature. The start of the growing season (SOS) has advanced by 4.86-6.71 days, and the end of the growing season (EOS) has been delayed by 4.32-6.19 days, lengthening the GS by 10.76-11.02 days in China as a whole during 1960-2011, depending on the T b chosen. Consistently, the GDD has totally increased 218.92-339.40 °C days during the 52 years, with trends more pronounced in those based on a lower T b. The GDD increase was significant (Mann-Kendall test, p < 0.01) over China except for the north of Southwest China, while the significant GS extension only scattered over China. Whereas the extensions of GS0 and GS5 were dominated by the advance in SOS, the GS10 extension was closely linked to the delay in EOS. Regionally, the GS extension in the eastern monsoon zone and northwest arid/semi-arid zone was driven by the advance in SOS and delay in EOS, respectively. Moreover, each variation has a substantial acceleration mostly in 1987 or 1996, and a speed reduction or even a trend reversal in the early 2000s. Changes in the thermal growing degree-days and season are expected to have great implications for biological phenology, agricultural production, and terrestrial carbon cycle in the future.

  5. Leaf Tissue C:N and Soil N are Modified by Growing Season and Goose Grazing Phenology in a Sub-Arctic Coastal Wetland of Western Alaska

    Science.gov (United States)

    Choi, R. T.; Beard, K. H.; Leffler, A. J.; Schmutz, J. A.; Welker, J. M.

    2014-12-01

    Climate change in Arctic wetlands is resulting in a widening phenological mismatch between the onset of the growing season and the arrival and hatch date of migratory geese, the primary consumers in the system. During the past three decades, the growing season has advanced but geese have not advanced arrival or hatch date at the same rate. Geese now arrive into a system that has been growing longer than in the past with potential changes in forage quality because sedges have their highest nutrient density shortly following emergence. One potential concomitant result of this phenological gap is altered carbon to nitrogen ratio (C:N) of leaf tissue being returned to the ecosystem as feces that is more N-poor. Altering the C:N of these inputs can further influence C and N cycling in the system. We examine the influence of advanced growing season and different arrival times by black brant on leaf and soil C:N ratio and soil N-form. Our experiment consists of six blocks with nine study plots each. Half the plots are warmed to advance the growing season. Two plots each receive early, typical, late, and no grazing; one plot is a control that is not warmed and grazing is natural. Leaf tissue was collected to determine C and N concentration using an elemental analyzer. Anion and cation exchange membranes were used to monitor inorganic N forms in soil; samples were analyzed via fluorescence following extraction. Soil water collected from lysimeters was analyzed for organic N. Warming advanced plant growth between one and two weeks and resulted in higher C:N of leaf tissue Geese maintained 'grazing lawns', areas of exceptionally short vegetation, where plants had high N compared to non-grazed areas. Grazing early in the season promoted higher N content of leaves and soil while grazing late had little influence on N. The timing of the growing season and grazing both have important implications for C and N in this system.

  6. season.

    African Journals Online (AJOL)

    Makoba bay, there is net flux of water from the bay to the open ocean during wet season. Residual salt fluxes between the bay and the open ocean indicate advective salt export. Exchange of water between the bay with the open ocean plays a role of replacing exported salt via mixing. ..... The human impact on the.

  7. Effects of repeated growing season prescribed fire on the structure and composition of pine-hardwood forests in the southeastern Piedmont, USA

    Science.gov (United States)

    Matthew Reilly; Kenneth Outcalt; Joseph O’Brien; Dale Wade

    2016-01-01

    We examined the effects of repeated growing season prescribed fire on the structure and composition of mixed pine–hardwood forests in the southeastern Piedmont region, Georgia, USA. Plots were burned two to four times over an eight-year period with low intensity surface fires during one of four six-week long periods from early April to mid-September. Density...

  8. Effects of Repeated Growing Season Prescribed Fire on the Structure and Composition of Pine–Hardwood Forests in the Southeastern Piedmont, USA

    Directory of Open Access Journals (Sweden)

    Matthew J. Reilly

    2016-12-01

    Full Text Available We examined the effects of repeated growing season prescribed fire on the structure and composition of mixed pine–hardwood forests in the southeastern Piedmont region, Georgia, USA. Plots were burned two to four times over an eight-year period with low intensity surface fires during one of four six-week long periods from early April to mid-September. Density of saplings (0.25–11.6 cm diameter at breast height was significantly reduced after one or two fires during the first four-year period. Sapling density declined with additional burning over the next four years, but density of mesic hardwoods including sweetgum (Liquidambar styraciflua and red maple (Acer rubrum remained relatively high (~865 stems ha−1. Repeated burning had little effect on density or basal area of trees (≥11.7 cm dbh and changes in overstory structure were limited to small increases in the quadratic mean diameter of all trees and pines. We found little evidence to suggest differential effects on structure or composition due to timing of burn within the growing season. Although repeated growing season burning alters midstory structure and composition, burning alone is unlikely to result in immediate shifts in overstory composition or structure in mixed pine–hardwood forests of the southeastern Piedmont region.

  9. Spatiotemporal variations in growing season exchanges of CO2, H2O,and sensible heat in agricultural fields of the Southern GreatPlains

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Marc L.; Billesbach, David P.; Berry, Joseph A.; Riley,William J.; Torn, Margaret S.

    2007-06-13

    Climate, vegetation cover, and management create fine-scaleheterogeneity in unirrigated agricultural regions, with important but notwell-quantified consequences for spatial and temporal variations insurface CO2, water, and heat fluxes. We measured eddy covariance fluxesin seven agricultural fields--comprising winter wheat, pasture, andsorghum--in the U.S. Southern Great Plains (SGP) during the 2001-2003growing seasons. Land-cover was the dominant source of variation insurface fluxes, with 50-100 percent differences between fields planted inwinter-spring versus fields planted in summer. Interannual variation wasdriven mainly by precipitation, which varied more than two-fold betweenyears. Peak aboveground biomass and growing-season net ecosystem exchange(NEE) of CO2 increased in rough proportion to precipitation. Based on apartitioning of gross fluxes with a regression model, ecosystemrespiration increased linearly with gross primary production, but with anoffset that increased near the time of seed production. Because theregression model was designed for well-watered periods, it successfullyretrieved NEE and ecosystem parameters during the peak growing season,and identified periods of moisture limitation during the summer. Insummary, the effects of crop type, land management, and water limitationon carbon, water, and energy fluxes were large. Capturing the controllingfactors in landscape scale models will be necessary to estimate theecological feedbacks to climate and other environmental impactsassociated with changing human needs for agricultural production of food,fiber, and energy.

  10. The variation of the water deficit during the winter wheat growing season and its impact on crop yield in the North China Plain.

    Science.gov (United States)

    Wu, Jianjun; Liu, Ming; Lü, Aifeng; He, Bin

    2014-11-01

    The North China Plain (NCP) is one of the main agricultural areas in China. However, it is also widely known for its water shortages, especially during the winter wheat growing season. Recently, climate change has significantly affected the water environment for crop growth. Analyzing the changes in the water deficit, which is only affected by climate factor, will help to improve water management in the NCP. In this study, the Decision Support System for Agrotechnology Transfer (DSSAT) was used to investigate the variations in the water deficit during the winter wheat growing season from 1961 to 2010 in 12 selected stations in the NCP. To represent the changes in the water deficit without any artificial affection, the rainfed simulation was used. Over the past 50 years, the average temperature during the winter wheat growing season increased approximately 1.42 °C. The anthesis date moved forward approximately 7-10 days and to late April, which increased the water demand in April. Precipitation in March and May showed a positive trend, but there was a negative trend in April. The water deficit in late April and early May became more serious than before, with an increasing trend of more than 0.1 mm/year. In addition, because the heading stage, which is very important to crop yield of winter wheat, moved forward, the impact of water deficit in late April was more serious to crop yield.

  11. Effects of Foliar Application of Nitrogen, Zinc and Manganese on Yield, Yield Components and Grain Quality of Chickpea in Two Growing Seasons

    Directory of Open Access Journals (Sweden)

    B. Shirani

    2015-09-01

    Full Text Available To study the effects of foliar application of zinc, manganese and nitrogen on yield, yield components and grain quality of chickpea (Cicer arientinum L. two experiments, one in autumn and the other in spring were conducted at Research Farm, Shahrekord University in 2009-2010 growing season each as a randomized complete block design with three replications. The treatments were foliar application of zinc sulfate, manganese sulfate zinc sulfate and manganese sulfate mixture, nitrogen and distilled water (as control. The results showed that planting season had a significant effect on plant height, 100-seed weight and seed yield. All measured traits, except plant height, increased in winter compared to spring growing season. This increase was more than 12% for grain yield. Foliar application of nutrients significantly affected seed yield and seed yield components. Foliar application of nitrogen, presumably, through significant increase in number of pods per plant, number of seeds per plant and 100-seed weight, increased the grain yield by 6.2% compared to control. Foliar application × planting season interactions were significant for plant height and number of pods per plant. Foliar application of nitrogen caused a significant increase in grain yield and protein content. Foliar application of zinc sulphate significantly increased Zn content of grains however it did not affect seed yield. In conclusion, foliar application of nitrogen could be suggested for increasing protein and grain yield in chickpea under similar conditions to that of the present study.

  12. Seasonal variation of macro and trace mineral contents in 14 browse species that grow in northeastern Mexico.

    Science.gov (United States)

    Ramirez, R G.; Haenlein, G F.W.; Núñez-González, M A.

    2001-02-01

    Leaves and twigs from shrub species consumed by range goats: Acacia berlandieri, Acacia farnesiana, Acacia greggii, Acacia rigidula, Celtis pallida, Cercidium macrum, Condalia obovata, Cordia boissieri, Desmanthus virgathus, Leucaena leucocephala, Leucophyllum texanum, Opuntia lindehimieri, Porlieria angustifolia, Prosopis glandulosa, and Ziziphus obtusifolia were evaluated for comparative seasonal contents of Ca, P, Mg K, Zn, Mn, Cu and Fe. Plants were collected in summer (September 12, 1992), fall (November 20, 1992), winter (February 20, 1993) and spring (May 22, 1993) in Marín, County, Nuevo Leon, Mexico. During spring and summer mineral concentrations were higher in general. Only Ca, Mg, K, and Fe were in substantial amounts in all seasons to meet adult goat requirements. With the exception of spring, shrubs had extremely low P concentrations. Manganese, Cu and Zn in most plants had low marginal levels to meet adult goat requirements. Moreover, potential intake of P, Mn, Cu and Zn in shrub species by goats weighing 50kg BW consuming 2.0kg per day DM was low. However, plants such as D. virgathus, L. texanum, P. glandulosa, L. leucocephala and C. macrum can be considered prominent components in diets of range goats because of their high mineral concentrations. It appears that ration formulations for range goats in northeastern Mexico should include P, Mn, Cu and Zn in all seasons of the year.

  13. The growing season, but not the farming system, is a food safety risk determinant for leafy greens in the mid-Atlantic region of the United States.

    Science.gov (United States)

    Marine, Sasha C; Pagadala, Sivaranjani; Wang, Fei; Pahl, Donna M; Melendez, Meredith V; Kline, Wesley L; Oni, Ruth A; Walsh, Christopher S; Everts, Kathryne L; Buchanan, Robert L; Micallef, Shirley A

    2015-04-01

    Small- and medium-size farms in the mid-Atlantic region of the United States use varied agricultural practices to produce leafy greens during spring and fall, but the impact of preharvest practices on food safety risk remains unclear. To assess farm-level risk factors, bacterial indicators, Salmonella enterica, and Shiga toxin-producing Escherichia coli (STEC) from 32 organic and conventional farms were analyzed. A total of 577 leafy greens, irrigation water, compost, field soil, and pond sediment samples were collected. Salmonella was recovered from 2.2% of leafy greens (n = 369) and 7.7% of sediment (n = 13) samples. There was an association between Salmonella recovery and growing season (fall versus spring) (P = 0.006) but not farming system (organic or conventional) (P = 0.920) or region (P = 0.991). No STEC was isolated. In all, 10% of samples were positive for E. coli: 6% of leafy greens, 18% of irrigation water, 10% of soil, 38% of sediment, and 27% of compost samples. Farming system was not a significant factor for levels of E. coli or aerobic mesophiles on leafy greens but was a significant factor for total coliforms (TC) (P organic farm samples. Growing season was a factor for aerobic mesophiles on leafy greens (P = 0.004), with higher levels in fall than in spring. Water source was a factor for all indicator bacteria (P factors contributing to microbial contamination on farms growing leafy greens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Changes in growth rate and macroelement and trace element accumulation in Hydrocharis morsus-ranae L. during the growing season in relation to environmental contamination.

    Science.gov (United States)

    Polechońska, Ludmiła; Samecka-Cymerman, Aleksandra; Dambiec, Małgorzata

    2017-02-01

    The temporal variations in plant chemistry connected with its life cycle may affect the cycling of elements in an ecosystem as well as determine the usefulness of the species in phytoremediation and bioindication. In this context, there is a gap in knowledge on the role of floating plants for elements cycling in aquatic reservoirs. The aim of the study was to determine if there are variations in Hydrocharis morsus-ranae (European frog-bit) bioaccumulation capacity and the growth rate of its population during the growing season and to test the impact of environmental pollution on these features. The content of macroelements (Ca, K, Mg, N, Na, P, S) and trace metals (Cd, Co, Cu, Cr, Hg, Fe, Mn, Ni, Pb, Zn) was determined in H. morsus-ranae collected monthly from June to October from habitats differing in environmental contamination. The results showed that the highest content of most trace metals (Co, Cr, Cu, Hg, Mn, Ni, Zn) and some nutrients (N, P) in plants as well as the greatest bioaccumulation efficiency occurred simultaneously in the beginning of the growing season. In the following months, a dilution effect (manifested by a decrease in content) related to the rapid growth was observed. Co, Mn, and Ni content in plant tissues reflected the level of environmental contamination throughout the growing season which makes H. morsus-ranae a potential biomonitor of pollution for these metals. Considering the great bioaccumulation ability, high sensitivity to contamination, and low biomass of European frog-bit in polluted systems, further investigation is required to assess the real phytoremediation capability of the species.

  15. Comparison of leaf water use efficiency of oak and sycamore in the canopy over two growing seasons

    OpenAIRE

    Stokes, Victoria J.; Morecroft, Michael D.; Morison, James I.L.

    2010-01-01

    The seasonal trends in water use efficiency of sun and shade leaves of mature oak (Quercus robur) and sycamore (Acer pseudoplatanus) trees were assessed in the upper canopy of an English woodland. Intrinsic water use efficiency (net CO2 assimilation rate/leaf conductance, A/g) was measured by gas exchange and inferred from C isotope discrimination (δ13C) methods. Shade leaves had consistently lower δ13C than sun leaves (by 1–2‰), the difference being larger in sycamore. Buds had distinct sun ...

  16. Projections for the changes in growing season length of tree-ring formation on the Tibetan Plateau based on CMIP5 model simulations.

    Science.gov (United States)

    He, Minhui; Yang, Bao; Shishov, Vladimir; Rossi, Sergio; Bräuning, Achim; Ljungqvist, Fredrik Charpentier; Grießinger, Jussi

    2018-04-01

    The response of the growing season to the ongoing global warming has gained considerable attention. In particular, how and to which extent the growing season will change during this century is essential information for the Tibetan Plateau, where the observed warming trend has exceeded the global mean. In this study, the 1960-2014 mean length of the tree-ring growing season (LOS) on the Tibetan Plateau was derived from results of the Vaganov-Shashkin oscilloscope tree growth model, based on 20 composite study sites and more than 3000 trees. Bootstrap and partial correlations were used to evaluate the most significant climate factors determining the LOS in the study region. Based on this relationship, we predicted the future variability of the LOS under three emission scenarios (Representative Concentration Pathways (RCP) 2.6, 6.0, and 8.5, representing different concentrations of greenhouse gasses) derived from 17 Earth system models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5). The averaged LOS on the Tibetan Plateau is 103 days during the period 1960-2014, and April-September minimum temperature is the strongest factor controlling the LOS. We detected a general increase in the LOS over the twenty-first century under all the three selected scenarios. By the middle of this century, LOS will extend by about 3 to 4 weeks under the RCPs 2.6 and 6.0, and by more than 1 month (37 days) under the RCP 8.5, relative to the baseline period 1960-2014. From the middle to the end of the twenty-first century, LOS will further extend by about 3 to 4 weeks under the RCPs 6.0 and 8.5, respectively. Under the RCP 2.6 scenario, however, the extension reaches a plateau at around 2050 and about 2 weeks LOS extension. In total, we found an average rate of 2.1, 3.6, and 5.0 days decade -1 for the LOS extension from 2015 to 2100 under the RCPs 2.6, 6.0, and 8.5, respectively. However, such estimated LOS extensions may be offset by other ecological

  17. Projections for the changes in growing season length of tree-ring formation on the Tibetan Plateau based on CMIP5 model simulations

    Science.gov (United States)

    He, Minhui; Yang, Bao; Shishov, Vladimir; Rossi, Sergio; Bräuning, Achim; Ljungqvist, Fredrik Charpentier; Grießinger, Jussi

    2017-11-01

    The response of the growing season to the ongoing global warming has gained considerable attention. In particular, how and to which extent the growing season will change during this century is essential information for the Tibetan Plateau, where the observed warming trend has exceeded the global mean. In this study, the 1960-2014 mean length of the tree-ring growing season (LOS) on the Tibetan Plateau was derived from results of the Vaganov-Shashkin oscilloscope tree growth model, based on 20 composite study sites and more than 3000 trees. Bootstrap and partial correlations were used to evaluate the most significant climate factors determining the LOS in the study region. Based on this relationship, we predicted the future variability of the LOS under three emission scenarios (Representative Concentration Pathways (RCP) 2.6, 6.0, and 8.5, representing different concentrations of greenhouse gasses) derived from 17 Earth system models participating in the Coupled Model Intercomparison Project Phase 5 (CMIP5). The averaged LOS on the Tibetan Plateau is 103 days during the period 1960-2014, and April-September minimum temperature is the strongest factor controlling the LOS. We detected a general increase in the LOS over the twenty-first century under all the three selected scenarios. By the middle of this century, LOS will extend by about 3 to 4 weeks under the RCPs 2.6 and 6.0, and by more than 1 month (37 days) under the RCP 8.5, relative to the baseline period 1960-2014. From the middle to the end of the twenty-first century, LOS will further extend by about 3 to 4 weeks under the RCPs 6.0 and 8.5, respectively. Under the RCP 2.6 scenario, however, the extension reaches a plateau at around 2050 and about 2 weeks LOS extension. In total, we found an average rate of 2.1, 3.6, and 5.0 days decade-1 for the LOS extension from 2015 to 2100 under the RCPs 2.6, 6.0, and 8.5, respectively. However, such estimated LOS extensions may be offset by other ecological factors that

  18. A model of seasonal foliage dynamics of the subtropical mangrove species Rhizophora stylosa Griff. growing at the northern limit of its distribution

    Directory of Open Access Journals (Sweden)

    Sahadev Sharma

    2014-08-01

    Full Text Available Background Progress of forest production in response to the environment requires a quantitative understanding of leaf area development. Therefore, it is necessary to investigate the dynamics of seasonal crown foliage in order to understand the productivity of mangroves, which play an important role in the subtropical and tropical coastlines of the world. Method Crown foliage dynamics of the mangrove Rhizophora stylosa were studies to reveal patterns of leaf recruitment, survival and seasonal leaf area growth. Results Flushing of leaves occurred throughout the year, but both flushing and leaf area growth pattern of leaves varied with season. Maximum flushing occurred in summer, but leaf areas did not differ significantly with season. The half-expansion period is longer, and the intrinsic rate of increase was lower in winter. Summer flushed leaves grew faster at their initial stage and reached their maximum area over a shorter period of time. The difference in temperature and air vapor pressure deficit (VPD between summer and winter contributed to the present dynamics of foliage patterns. The mean leaf longevity was estimated to be 13.1 month. The crown foliage area was almost stable throughout the year. Conclusions Homeostatic control of the crown foliage area may be accompanied by the existence of ecophysiological mechanisms in R. stylosa. Integrating crown foliage dynamics into forest models represents an important step towards incorporating physiological mechanisms into the models for predicting growth responses to environmental changes and for understanding the complex responses of tree growth and litter production.

  19. Studies on the abnormality of embryo sac and pollen fertility in aurotetraploid rice during different growing seasons

    International Nuclear Information System (INIS)

    Shahid, M.; Jilanfan, S.; Changmin, W.; Peng, Z.; Xiang-dong, X.

    2010-01-01

    Auto tetraploid rice has a great genetic potential but low seed setting rate is the major encumbrance in its use. Embryo sac fertility and pollen fertility are the most important factors which affect the seed setting rate in auto tetraploid rice. Whole mount eosin B-staining confocal laser scanning microscopy (WE-CLSM) was used to study the fertility and abnormalities in embryo sacs of diploid and auto tetraploid rice during different seasons. The results indicated that the embryo sac fertility (64.5%) was much low in auto tetraploid than that in diploid rice (86%), and five main types of abnormal embryo sac were found in all 10 auto tetraploid rice. Moreover, some other type abnormal embryo sacs were also observed in auto tetraploid rice. Embryo sac without female germ unit and embryo sac degeneration were the most frequent types of abnormalities in auto tetraploid rice. Embryo sac fertility ranged from 49.3% to 79.3%, pollen fertility ranged from 56.2 to 85.9%, and seed setting rate varied from 12.5 to 69.01% in various genotypes of auto tetraploid rice. Embryo sac and pollen fertility were found to have a significant correlation with seed setting rate. Seasons have significant effect on pollen and embryo sac fertility in both type of rice. All the auto tetraploid lines exhibited different types of embryo sac abnormalities which indicated that these might be related to different genotypes. (author)

  20. Deconvolution of pigment and physiologically related photochemical reflectance index variability at the canopy scale over an entire growing season.

    Science.gov (United States)

    Hmimina, G; Merlier, E; Dufrêne, E; Soudani, K

    2015-08-01

    The sensitivity of the photochemical reflectance index (PRI) to leaf pigmentation and its impacts on its potential as a proxy for light-use efficiency (LUE) have recently been shown to be problematic at the leaf scale. Most leaf-to-leaf and seasonal variability can be explained by such a confounding effect. This study relies on the analysis of PRI light curves that were generated at the canopy scale under natural conditions to derive a precise deconvolution of pigment-related and physiologically related variability in the PRI. These sources of variability were explained by measured or estimated physiologically relevant variables, such as soil water content, that can be used as indicators of water availability and canopy chlorophyll content. The PRI mainly reflected the variability in the pigment content of the canopy. However, the corrected PRI, which was obtained by subtracting the pigment-related seasonal variability from the PRI measurement, was highly correlated with the upscaled LUE measurements. Moreover, the sensitivity of the PRI to the leaf pigment content may mask the PRI versus LUE relationship or result in an artificial relationship that reflects the relationship of chlorophyll versus LUE, depending on the species phenology. © 2015 John Wiley & Sons Ltd.

  1. Determining of the Effect of Lysine:calorie Ratio on Growth Performance and Blood Urea Nitrogen of Growing Barrows and Gilts in Hot Season and Cool Season in a Commercial Environment.

    Science.gov (United States)

    Zhang, Z F; Kim, I H

    2013-03-01

    Two experiments were conducted to determine an optimum Lys:calorie ratio (g of total dietary Lys/Mcal of DE) for growing barrows and gilts in cool and hot seasons in a commercial environment. In Exp. 1, 96 barrows and 96 gilts were randomly allocated in 1 of 4 dietary treatments (2.7, 3.0, 3.3, 3.6 g of Lys/Mcal of DE). Each treatment had 12 replicate pens with 4 pigs per pen. The experiment lasted for 34 d in the cool season (March 12th to April 15th). Diets were based on corn-wheat-soybean meal. Lys:calorie ratio were attained by adjusting the amount of corn and soybean and supplementation of crystalline Lys. Total Lys intake and available Lys intake were increased (pcalorie ratio increased. The BUN concentration on d 34 for barrows, and BUN change for barrows and gilts linearly increased (pcalorie ratio. For gilts, back fat was decreased and then increased (Quadratically, pcalorie ratio. Exp. 2 had a similar design as Exp. 1 with the exception that Exp. 2 was conducted in hot season (June 30th to September 11th) for 42 d. Diet of Exp. 2 was the same as Exp. 1. Total Lys intake and available Lys intake increased (pcalorie increased. On d 42, the BUN concentration increased (pcalorie ratio. In conclusion, dietary Lys:calorie ratio of 2.7 g of Lys/Mcal of DE could satisfy the requirement of 25 to 50 kg growing pigs. Increasing dietary Lys:calorie ratio could increase BUN concentration in growing pigs.

  2. The Growing Season, but Not the Farming System, Is a Food Safety Risk Determinant for Leafy Greens in the Mid-Atlantic Region of the United States

    Science.gov (United States)

    Marine, Sasha C.; Pagadala, Sivaranjani; Wang, Fei; Pahl, Donna M.; Melendez, Meredith V.; Kline, Wesley L.; Oni, Ruth A.; Walsh, Christopher S.; Everts, Kathryne L.; Buchanan, Robert L.

    2015-01-01

    Small- and medium-size farms in the mid-Atlantic region of the United States use varied agricultural practices to produce leafy greens during spring and fall, but the impact of preharvest practices on food safety risk remains unclear. To assess farm-level risk factors, bacterial indicators, Salmonella enterica, and Shiga toxin-producing Escherichia coli (STEC) from 32 organic and conventional farms were analyzed. A total of 577 leafy greens, irrigation water, compost, field soil, and pond sediment samples were collected. Salmonella was recovered from 2.2% of leafy greens (n = 369) and 7.7% of sediment (n = 13) samples. There was an association between Salmonella recovery and growing season (fall versus spring) (P = 0.006) but not farming system (organic or conventional) (P = 0.920) or region (P = 0.991). No STEC was isolated. In all, 10% of samples were positive for E. coli: 6% of leafy greens, 18% of irrigation water, 10% of soil, 38% of sediment, and 27% of compost samples. Farming system was not a significant factor for levels of E. coli or aerobic mesophiles on leafy greens but was a significant factor for total coliforms (TC) (P bacteria (P < 0.001), and end-of-line groundwater had marginally higher TC counts than source samples (P = 0.059). Overall, the data suggest that seasonal events, weather conditions, and proximity of compost piles might be important factors contributing to microbial contamination on farms growing leafy greens. PMID:25616798

  3. Radionuclide concentrations in/on vegetation at radioactive-waste disposal Area G during the 1995 growing season. Progress report

    International Nuclear Information System (INIS)

    Fresquez, P.R.; Vold, E.L.; Naranjo, L. Jr.

    1996-01-01

    Overstory (pinon pine) and understory (grass and forb) vegetation were collected within and around selected points at Area G--a low- level radioactive solid-waste disposal facility at Los Alamos National Laboratory--for the analysis of tritium ( 3 H), strontium ( 90 Sr), plutonium ( 238 Pu and 239 Pu), cesium ( 137 Cs), and total uranium. Also, heavy metals (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and Tl) in/on vegetation were determined. In general, most (unwashed) vegetation collected within and around Area G contained 3 H, uranium, 238 Pu, and 239 Pu in higher concentrations than vegetation collected from background areas. Tritium, in particular, was detected as high as 7300 pCi mL -1 in understory vegetation collected from the west side of the transuranic (TRU) pads. The south and west ends of the tritium shaft field also contained elevated levels of 3 H in overstory, and especially in understory vegetation, as compared to background; this suggests that 3 H may be migrating from this waste repository through surface and subsurface pathways. Also, understory vegetation collected north of the TRU pads (adjacent to the fence line of Area G) contained the highest values of 238 Pu and 239 Pu as compared to background, and may be a result of surface holding, storage, and/or disposal activities

  4. Early Season Large-Area Winter Crop Mapping Using MODIS NDVI Data, Growing Degree Days Information and a Gaussian Mixture Model

    Science.gov (United States)

    Skakun, Sergii; Franch, Belen; Vermote, Eric; Roger, Jean-Claude; Becker-Reshef, Inbal; Justice, Christopher; Kussul, Nataliia

    2017-01-01

    Knowledge on geographical location and distribution of crops at global, national and regional scales is an extremely valuable source of information applications. Traditional approaches to crop mapping using remote sensing data rely heavily on reference or ground truth data in order to train/calibrate classification models. As a rule, such models are only applicable to a single vegetation season and should be recalibrated to be applicable for other seasons. This paper addresses the problem of early season large-area winter crop mapping using Moderate Resolution Imaging Spectroradiometer (MODIS) derived Normalized Difference Vegetation Index (NDVI) time-series and growing degree days (GDD) information derived from the Modern-Era Retrospective analysis for Research and Applications (MERRA-2) product. The model is based on the assumption that winter crops have developed biomass during early spring while other crops (spring and summer) have no biomass. As winter crop development is temporally and spatially non-uniform due to the presence of different agro-climatic zones, we use GDD to account for such discrepancies. A Gaussian mixture model (GMM) is applied to discriminate winter crops from other crops (spring and summer). The proposed method has the following advantages: low input data requirements, robustness, applicability to global scale application and can provide winter crop maps 1.5-2 months before harvest. The model is applied to two study regions, the State of Kansas in the US and Ukraine, and for multiple seasons (2001-2014). Validation using the US Department of Agriculture (USDA) Crop Data Layer (CDL) for Kansas and ground measurements for Ukraine shows that accuracies of greater than 90% can be achieved in mapping winter crops 1.5-2 months before harvest. Results also show good correspondence to official statistics with average coefficients of determination R(exp. 2) greater than 0.85.

  5. Radionuclide Concentrations in Soils and Vegetation at Low-Level Radioactive Waste Disposal Area G during the 1997 Growing Season

    Energy Technology Data Exchange (ETDEWEB)

    L. Naranjo, Jr.; P. R. Fresquez; R. J. Wechsler

    1998-08-01

    Soil and overstory and understory vegetation (washed and unwashed) collected at eight locations within and around Area G-a low-level radioactive solid-waste disposal facility at Los Alamos National Laboratory-were analyzed for 3H, 238Pu, 239Pu, 137CS, 234U, 235U, 228AC, Be, 214Bi, 60Co, 40& 54Mn, 22Na, 214Pb and 208Tl. In general, most radionuclide concentrations, with the exception of 3Ef and ~9Pu, in soils and overstory and understory vegetation collected from within and around Area G were within upper (95'%) level background concentrations. Although 3H concentrations in vegetation from most sites were significantly higher than background (>2 pCi mL-l), concentrations decreased markedly in comparison to last year's results. The highest `H concentration in vegetation was detected from a juniper tree that was growing over tritium shaft /+150; it contained 530,000 pCi 3H mL-l. Also, as in the pas~ the transuranic waste pad area contained the highest levels of 239Pu in soils and in understory vegetation as compared to other areas at Area G.

  6. Effects of Corn Straw Returning and Nitrogen Fertilizer Application Methods on N2O Emission from Wheat Growing Season

    Directory of Open Access Journals (Sweden)

    XU Yu

    2015-12-01

    Full Text Available Based on a wheat field experiment, the effect of four treatments such as no-straw returning (SN, straw returning (SR, control release fertilizer application(SRC and nitrogen drilling(SRR on N2O emission was studied using the static chamber method and the gas chromatographic technique. The results indicated that the wheat field was the sources of N2O emission. The N2O emission peaks followed each time of fertilizer application and irrigation, and usually continued for 1~2 weeks. N2O emissions accounted for more than 40% of total emissions during the N2O emission peak. The amount of N2O emission during three growing stage of wheat from high to low was arranged in turn pre-wintering period, post-wintering period and wintering period. N2O emission could be increased by straw returning. Compared with SN, N2O emission could be enhanced by 48.6% under SR. Both SRC and SRR could decrease the N2O emission, increase wheat yield and economic benefit, especially the latter. Nitrogen drilling is a good method for yield increment and N2O abatement.

  7. Productivity of a plantation of asparagus (Asparagus officinalis var. Altilis initiated green seedlings over four growing seasons

    Directory of Open Access Journals (Sweden)

    Castagnino, A.M.

    2014-01-01

    Full Text Available Although there are two initiation systems for an asparagus crop, i.e. by means of crowns and by means of seedlings, only the former allows the initiation of the definitive plantation in the first year. In order to determine the incidence of the seedling size throughout the first six years since planting, a trial was started on august 21, 2002, with three cell sizes: PG: big, PM: medium and PCH: small (70, 50 and 20 cm3 respectively and two densities: D1:35,714 and D2: 17,857 pl.ha-1, using the hybrid UC-157 and evaluating its productivity in the period 2005- 2008. Fresh weight per harvest (PFC and total annual fresh weight per ha (PFT, number of turions per harvest (NTC and per ha (NT and average weight per turion (PPT were determined. The PTF 2005-2008 was 26.300 Kg ha-1 and NT, with an annual average of 6,575 Kg ha-1 and 480,180 turions, respectively. NT showed a growing tendency throughout the whole period. Whereas, while the PFT grew in 2005-2007, it decreased in 2008 due to lower PPT, caused possibly by intra-specific competition. PM allowed a greater yield PFC: 343 Kg ha-1. The PPT turned out to be similar to that in 2005-2007, however it decreased in 2008. D1 obtained the maximum yield throughout the whole period. It can be concluded that when the aim is to obtain high initial productivity, it would be advisable to use seedlings of good size. Besides, the choice of density is an important factor due to the fact that there seems to be a direct relationship between the planting frame used and the obtained productivity.

  8. Analysis of changes in thermal growing season indices (tGSI) and their relations with some selected atmospheric teleconnection patterns (ATPs) over the northwest of Iran.

    Science.gov (United States)

    Sabziparvar, Ali Akbar; Jahromi, Fatemeh Khoshhal

    2018-02-15

    The daily minimum air temperature data from 18 stations located in the northwest of Iran during the period 1986-2015 was used to analyse the inter-annual variations and trends of thermal growing season indices (tGSI) and their relations with different atmospheric teleconnection patterns (ATPs). To analyze the changes in tGSI, tGSS (thermal growing season start), tGSE (thermal growing season end), and tGSL, the time period between tGSS and tGSE were considered. Using non-parametric Mann-Kendall and Spearman tests, the existence of a significant trend for time series of the tGSI and the correlation between ATPs and tGSI was evaluated. For eliminating the effect of serial correlation on test results, the trend-free pre-whitening approach was applied. Furthermore, residual bootstrap method was used to estimate the standard deviation of the Spearman correlation coefficient between tGSI and ATPs. The climate-based results showed the maximum tGSL increase (13.3 days per decade) for SA-C-M climate. For SH-K-W climate, the maximum significant trends for tGSS and tGSE were 9.6 (earlier start) and 10.8 (delay) days per decade, respectively. In general, in all statistically significant cases, the main cause of the extended tGSL was both earlier tGSS and delayed tGSE. In regional scale, it was found that the most effective teleconnection pattern on tGSS and tGSE are MEI (positive correlation), occurring during late winter and spring, and PDO index (negative correlation) in the summer, respectively. Moreover, the tGSL demonstrated the highest correlation (negative) with PDO with 1-month delay. The findings highlight that the inter-annual variations of tGSI in northwest of Iran can be attributed to the influence of certain atmospheric teleconnection patterns such as MEI, PDO, NAO, AO, EA, and AMO.

  9. Effect of corn dry distiller grains plus solubles supplementation level on performance and digestion characteristics of steers grazing native range during forage growing season.

    Science.gov (United States)

    Martínez-Pérez, M F; Calderón-Mendoza, D; Islas, A; Encinias, A M; Loya-Olguín, F; Soto-Navarro, S A

    2013-03-01

    Two experiments were conducted to evaluate effects of corn dry distiller grains plus condensed solubles (DDGS) supplementation level on performance digestion characteristics of steers grazing native range during the forage growing season. In the performance study, 72 (206 ± 23.6 kg; 2008) and 60 (230 ± 11.3 kg; 2009) English crossbred steer calves were used in a randomized complete block design replicated over 2 yr. The grazing periods lasted 56 and 58 d and started on August 11 and 18 for 2008 and 2009, respectively. Each year, steers were blocked by BW (light, medium, and heavy), stratified by BW within blocks, and randomly assigned to 1 of 4 grazing groups. Each grazing group (6 steers in 2008 and 5 in 2009) was assigned to a DDGS supplementation levels (0, 0.2, 0.4, and 0.6% BW). Grazing group served as the experimental unit with 12 groups per year receiving 1 of 4 treatments for 2 yr (n = 6). In the metabolism study, 16 English crossbred steers (360 ± 28.9 kg) fitted with ruminal cannulas grazing native range during the summer growing season were used in a completely randomized design to evaluate treatment effects on forage intake and digestion. The experiment was conducted during the first and second weeks of October 2008. Steers were randomly assigned to supplement level (0, 0.2, 0.4, and 0.6% BW; n = 4) and grazed a single native range pasture with supplements offered individually once daily at 0700 h. In the performance study, ADG (0.64, 0.75, 0.80, and 0.86 ± 0.03 kg/d for 0, 0.2, 0.4, and 0.6% BW, respectively) increased linearly (P = 0.01) with increasing DDGS supplementation level. In the metabolism study, forage OM, NDF, CP, and ether extract (EE) intake decreased (P ≤ 0.05) linearly with increasing DDGS supplementation level. Total CP and EE intake increased (P ≤ 0.002) with increasing DDGS supplementation level. Digestibility of OM, NDF, and EE increased (linear; P ≤ 0.008) whereas the soluble CP fraction of forage masticate sample

  10. Interactive effects of UV radiation and reduced precipitation on the seasonal leaf phenolic content/composition and the antioxidant activity of naturally growing Arbutus unedo plants.

    Science.gov (United States)

    Nenadis, Nikolaos; Llorens, Laura; Koufogianni, Agathi; Díaz, Laura; Font, Joan; Gonzalez, Josep Abel; Verdaguer, Dolors

    2015-12-01

    The effects of UV radiation and rainfall reduction on the seasonal leaf phenolic content/composition and antioxidant activity of the Mediterranean shrub Arbutus unedo were studied. Naturally growing plants of A. unedo were submitted to 97% UV-B reduction (UVA), 95% UV-A+UV-B reduction (UV0) or near-ambient UV levels (UVBA) under two precipitation regimes (natural rainfall or 10-30% rainfall reduction). Total phenol, flavonol and flavanol contents, levels of eight phenols and antioxidant activity [DPPH(●) radical scavenging and Cu (II) reducing capacity] were measured in sun-exposed leaves at the end of four consecutive seasons. Results showed a significant seasonal variation in the leaf content of phenols of A. unedo, with the lowest values found in spring and the highest in autumn and/or winter. Leaf ontogenetic development and/or a possible effect of low temperatures in autumn/winter may account for such findings. Regardless of the watering regime and the sampling date, plant exposure to UV-B radiation decreased the total flavanol content of leaves, while it increased the leaf content in quercitrin (the most abundant quercetin derivative identified). By contrast, UV-A radiation increased the leaf content of theogallin, a gallic acid derivative. Other phenolic compounds (two quercetin derivatives, one of them being avicularin, and one kaempferol derivative, juglanin), as well as the antioxidant activity of the leaves, showed different responses to UV radiation depending on the precipitation regime. Surprisingly, reduced rainfall significantly decreased the total amount of quantified quercetin derivatives as well as the DPPH scavenging activity in A. unedo leaves. To conclude, present findings indicate that leaves of A. unedo can be a good source of antioxidants throughout the year, but especially in autumn and winter. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Season progression, Ontogenesis and Environment affect Lespedeza cuneata Herbage Condensed Tannin, Fiber and Crude Protein Content

    Science.gov (United States)

    Sericea lespedeza [Lespedeza cuneata (Dumont de Courset) G. Don.; SL] is a perennial, warm-season forage legumes with wide adaptation, freeze tolerance, establishment ease and persistence under grazing. Its condensed tannins (CT) could be useful in ruminant systems, not simply as a protein source, b...

  12. Impacts of short-rotation early-growing season prescribed fire on a ground nesting bird in the central hardwoods region of North America

    Science.gov (United States)

    Pittman, H. Tyler; Krementz, David G.

    2016-01-01

    Landscape-scale short-rotation early-growing season prescribed fire, hereafter prescribed fire, in upland hardwood forests represents a recent shift in management strategies across eastern upland forests. Not only does this strategy depart from dormant season to growing season prescriptions, but the strategy also moves from stand-scale to landscape-scale implementation (>1,000 ha). This being so, agencies are making considerable commitments in terms of time and resources to this management strategy, but the effects on wildlife in upland forests, especially those dominated by hardwood canopy species, are relatively unknown. We initiated our study to assess whether this management strategy affects eastern wild turkey reproductive ecology on the Ozark-St. Francis National Forest. We marked 67 wild turkey hens with Global Positioning System (GPS) Platform Transmitting Terminals in 2012 and 2013 to document exposure to prescribed fire, and estimate daily nest survival, nest success, and nest-site selection. We estimated these reproductive parameters in forest units managed with prescribed fire (treated) and units absent of prescribed fire (untreated). Of 60 initial nest attempts monitored, none were destroyed or exposed to prescribed fire because a majority of fires occurred early than a majority of the nesting activity. We found nest success was greater in untreated units than treated units (36.4% versus 14.6%). We did not find any habitat characteristic differences between successful and unsuccessful nest-sites. We found that nest-site selection criteria differed between treated and untreated units. Visual concealment and woody ground cover were common selection criteria in both treated and untreated units. However, in treated units wild turkey selected nest-sites with fewer small shrubs (20 cm DBH) but not in untreated units. In untreated units wild turkey selected nest-sites with more large shrubs (≥5cm ground diameter) but did not select for small shrubs or large

  13. How does climate influence xylem morphogenesis over the growing season? Insights from long-term intra-ring anatomy in Picea abies.

    Science.gov (United States)

    Castagneri, Daniele; Fonti, Patrick; von Arx, Georg; Carrer, Marco

    2017-04-01

    During the growing season, the cambium of conifer trees produces successive rows of xylem cells, the tracheids, that sequentially pass through the phases of enlargement and secondary wall thickening before dying and becoming functional. Climate variability can strongly influence the kinetics of morphogenetic processes, eventually affecting tracheid shape and size. This study investigates xylem anatomical structure in the stem of Picea abies to retrospectively infer how, in the long term, climate affects the processes of cell enlargement and wall thickening. Tracheid anatomical traits related to the phases of enlargement (diameter) and wall thickening (wall thickness) were innovatively inspected at the intra-ring level on 87-year-long tree-ring series in Picea abies trees along a 900 m elevation gradient in the Italian Alps. Anatomical traits in ten successive tree-ring sectors were related to daily temperature and precipitation data using running correlations. Close to the altitudinal tree limit, low early-summer temperature negatively affected cell enlargement. At lower elevation, water availability in early summer was positively related to cell diameter. The timing of these relationships shifted forward by about 20 (high elevation) to 40 (low elevation) d from the first to the last tracheids in the ring. Cell wall thickening was affected by climate in a different period in the season. In particular, wall thickness of late-formed tracheids was strongly positively related to August-September temperature at high elevation. Morphogenesis of tracheids sequentially formed in the growing season is influenced by climate conditions in successive periods. The distinct climate impacts on cell enlargement and wall thickening indicate that different morphogenetic mechanisms are responsible for different tracheid traits. Our approach of long-term and high-resolution analysis of xylem anatomy can support and extend short-term xylogenesis observations, and increase our

  14. Effect of the growing season duration of sorghum and Sudan grass hybrids on the chemical composition and digestibility of organic matter

    Directory of Open Access Journals (Sweden)

    Jitka Dvořáčková

    2013-01-01

    Full Text Available In our experimental study we used the four most commonly grown (in the Czech Republic sorghum and Sudan grass hybrids from USA (Nutri Honey, Latte, Honey Graze, Big Kahuna and one hybrid from Germany (Bovital. The aim of the study was to compare these hybrids and to find out the influence of the growing season length on their nutrient composition and digestibility of organic matter. Samples were taken in the first cut, always in 14-day intervals. The crop was sown in early June, sampling started on July 19, 2010 and finished 8 weeks later on September 13, 2010.When assessing the influence of the growing season’s length the following values and development trends were discovered. Constant decreases over the testing period were recorded in nitrogen compounds – by 62 % (133.13 g, easily soluble sugars – 55. 5 % (40.06 g, organic matter digestibility 25.7 % (182.93 g and NDF (neutro – detergent fibre digestibility 31.5 % (73.2 g. Increasing trend, on the other hand, was recorded in fibre – by 30.4 % (99.2 g and its individual components: lignin, NDF and ADF (acido – detergent fibre.In the second part of the experiment we were studying the differences in nutrient composition and organic matter digestibility between the individual hybrids. Honey Graze was recorded as having the highest average content of easily soluble sugars 57.53 ± 0.43 g, with lowest fibre content (272.13 ± 2.49 g, lowest ADF content (331.4 ± 2.88 g and NDF content (440.4 ± 4.20 g and lignin (77.47 ± 0.71 g. This hybrid also showed the best organic matter of (657.07 ± 5.28 g; however, no statistically conclusive differences (P < 0.05 in terms of organic matter digestibility were recorded between this hybrid and the other ones. The Bovital hybrid had the highest content of nitrogen compounds over the entire growing season (138.73 ± 0.94 g. Statistically highly conclusive difference (P < 0.01 in nitrogen compounds was found between this hybrid

  15. Projected changes of thermal growing season over Northern Eurasia in a 1.5 °C and 2 °C warming world

    Science.gov (United States)

    Zhou, Baiquan; Zhai, Panmao; Chen, Yang; Yu, Rong

    2018-03-01

    Projected changes of the thermal growing season (TGS) over Northern Eurasia at 1.5 °C and 2 °C global warming levels are investigated using 22 CMIP5 models under both RCP4.5 and RCP8.5 scenarios. The multi-model mean projections indicate Northern Eurasia will experience extended and intensified TGSs in a warmer world. The prolongation of TGSs under 1.5 °C and 2 °C warming is attributed to both earlier onset and later termination, with the latter factor playing a dominating role. Interestingly, earlier onset is of greater importance under RCP4.5 than under RCP8.5 in prolonging TGS as the world warms by an additional 0.5 °C. Under both RCPs, growing degree day sum (GDD) above 5 °C is anticipated to increase by 0 °C-450 °C days and 0 °C-650 °C days over Northern Eurasia at 1.5 °C and 2 °C warming, respectively. However, effective GDD (EGDD) which accumulates optimum temperature for the growth of wheat, exhibits a decline in the south of Central Asia under warmer climates. Therefore, for wheat production over Northern Eurasia, adverse effects incurred by scorching temperatures and resultant inadequacy in water availability may counteract benefits from lengthening and warming TGS. In response to a future 1.5 °C and 2 °C warmer world, proper management and scientifically-tailored adaptation are imperative to optimize local-regional agricultural production.

  16. Effect of Nigella sativa or Curcumin on Daily Body Weight Gain, Feed Intake and some Physiological Functions in Growing Zaraibi Goats during Hot Summer Season

    International Nuclear Information System (INIS)

    Habeeb, A.A.M.; El Tarabany, A.A.

    2012-01-01

    Twenty one Zaraibi kids, aged 4-5 months and weighed on average 9.5±0.2 kg were divided into three groups, seven kids in each. The experiment was beginning after the end of weaning period and lasted 5 months (May, June, July, August and September). Kids in the 1 s t group were fed the basal ration (concentrate feed mixture plus Barseem hay without additives (Control), while those in the 2 n d and 3 r d groups were fed the same basal ration supplemented daily with crushed 2 gram from Nigella or Curcumin per one kg CFM, respectively. Nigella sativa (Nigella) and Curcumin addition to the diet of kids during months of the hot summer season comparison with control group improved significantly the final LBW at the end of 5 months by 5.56 and 4.8 kg and increased significantly average daily body gain (DBG) of kids by 62.2 and 54.25 g, respectively. Supplementation improved the animal immunity function i.e. total protein and globulin concentrations as well as thyroid hormonal levels (T 4 and T 3 ) and decreased the factor related to heart disease (total cholesterol and total lipids), glucose and cortisol levels in the blood plasma. At the same time, liver and kidney functions were not affected negatively by supplementation either with Nigella or Curcumin. Supplementation the diet of growing goats increased also significantly the Hb values and RBC'S count as well as the concentrations of Na, K, and Pi.

  17. Spatiotemporal variations of the start of thermal growing season for grassland on the Qinghai-Tibetan Plateau during 1961-2014

    Science.gov (United States)

    Zhu, Wenquan; Zhang, Donghai; Jiang, Nan; Zheng, Zhoutao

    2017-09-01

    The start of thermal growing season (STGS) is an important indicator for climate change effects on regional plant growth and development. This study comprehensively investigated and compared the spatiotemporal variations in STGS at 0 °C (STGS_0), 5 °C (STGS_5), and 10 °C (STGS_10) thresholds for grassland on the Qinghai-Tibetan Plateau (QTP) during 1961-2014. Although elevation was the predominant influencing factor of the spatial variations of STGSs, the effect of latitude should not be ignored at the low-elevation regions, especially for the STGS with a low-temperature threshold (e.g., STGS_0). With the decrease of temperature thresholds, the effect of elevation became weaker, while the effect of latitude became stronger. Significant advancing trends were observed in all the three STGSs, with greater advancing rate for STGS_0 (0.23 days·year-1) than that of STGS_5 (0.15 days·year-1) and STGS_10 (0.16 days·year-1). More obvious advancing trends were found after 1980, which coincided with more rapid climate warming. The advancing trends weakened after 1998 when climate warming hiatus occurred. Since positive and negative impacts may be simultaneously induced by the advanced STGSs, more observations are still needed to analyze their impacts on the growth and development of alpine grassland on the QTP.

  18. Spatial Patterns in Biogeochemical Processes During Peak Growing Season in Oiled and Unoiled Louisiana Salt Marshes: A Multi-Year Analysis

    Science.gov (United States)

    Chelsky, A.; Marton, J. M.; Bernhard, A. E.; Giblin, A. E.; Setta, S. P.; Hill, T. D.; Roberts, B. J.

    2016-02-01

    Louisiana salt marshes are important sites for carbon and nitrogen cycling because they can mitigate fluxes of nutrients and carbon to the Gulf of Mexico where a large hypoxic zone develops annually. The aim of this study was to investigate spatial and temporal patterns of biogeochemical processes in Louisiana coastal wetlands during peak growing season, and to investigate whether the Deepwater Horizon oil spill resulted in persistent changes to these rates. We measured nitrification potential and sediment characteristics at two pairs of oiled/unoiled marshes in three regions across the Louisiana coast (Terrebonne and east and west Barataria Bay) in July from 2012 to 2015, with plots along a gradient from the salt marsh edge to the interior. Rates of nitrification potential across the coast (overall mean of 901 ± 115 nmol gdw-1 d-1 from 2012-2014) were high compared to other published rates for salt marshes but displayed high variability at the plot level (4 orders of magnitude). Within each region interannual means varied by factors of 2-5. Nitrification potential did not differ with oiling history, but did display consistent spatial patterns within each region that corresponded to changes in relative elevation and inundation, which influence patterns of soil properties and microbial communities. In 2015, we also measured greenhouse gas (CO2, N2O and CH4) production and denitrification enzyme activity rates in addition to nitrification potential across the region to investigate spatial relationships between these processes.

  19. Effect of Nigella sativa or Curcumin on Daily Body Weight Gain, Feed Intake and some Physiological Functions in Growing Zaraibi Goats during Hot Summer Season

    International Nuclear Information System (INIS)

    Habeeb, A.A.M.; El-Tarabany, A.A.

    2012-01-01

    Twenty one Zaraibi kids, aged 4-5 months and weighed on average 9.5 ±0.2 kg were divided into three groups, seven kids in each. The experiment was beginning after the end of weaning period and lasted 5 months (May, June, July, August and September). Kids in the 1st group were fed the basal ration (concentrate feed mixture plus Barseem hay without additives (Control), while those in the 2nd and 3rd groups were fed the same basal ration supplemented daily with crushed 2 gram from Nigella or Curcumin per one kg CFM, respectively. Nigella sativa (Nigella) and Curcumin addition to the diet of kids during months of the hot summer season comparison with control group improved significantly the final LBW at the end of 5 months by 5.56 and 4.8 kg and increased significantly average daily body gain (DBG) of kids by 62.2 and 54.25 g, respectively. Supplementation improved the animal immunity function i.e. total protein and globulin concentrations as well as thyroid hormonal levels (T4 and T3) and decreased the factor related to heart disease (total cholesterol and total lipids), glucose and cortisol levels in the blood plasma. At the same time, liver and kidney functions were not affected negatively by supplementation either with Nigella or Curcumin. Supplementation the diet of growing goats increased also significantly the Hb values and RBC'S count as well as the concentrations of Na, K, and Pi.

  20. Growing season changes in Fennoscandia and Kola peninsula during the period 1982 to 1999 - Implications for reindeer husbandry (In Norwegian with Summary in English

    Directory of Open Access Journals (Sweden)

    Hans Tømmervik

    2005-04-01

    the length of the growing season in Fennoscandia and Kola Peninsula during the last two decades. We used phenological observation data for birch (Betula pubescens, and birch give a significant contribution to the reflectance from the ground in order to analyze the satellite data. A method using an individual threshold NDVI value for defining the onset of the growing season applied to each pixel for each year was chosen, and a high correlation was found between the NDVI data and in-situ phenological data on onset of leafing of birch. Determining the end of growing season based on a threshold NDVI value shows a lower correlation with surface data, but the timing by the set threshold is observed to measure somewhere in-between the onset of yellowing and all leaves fallen. In general, the results show a pattern according to vegetation zones and the altitude gradient, and partly according to vegetation sections. There are high regional differences in trends in the onset of spring. In the southern part of Fennoscandia, and on the oceanic west coast of Norway, the spring starts considerably earlier in the late nineties compared to the early eighties. The spring is stable or delayed in the northern boreal zone, which occupies large areas of northern Fennoscandia and Kola peninsula, and the same trend is also found in the alpine areas which occupies parts of both southern and northern Norway. The strongest delay occurred in the most continental section of the northern boreal zone. In the entire boreo-nemoral and nemoral zone, which occupy most of the southern part of Fennoscandia, the trend is opposite. In these areas the spring starts considerably earlier, in some parts several weeks. In the most oceanic section, the coastline of Western Norway, the spring also starts earlier. This earlier trend fits with the pattern from western and central Europe, and is likely to be related to increased spring temperature. At the same time the autumn is delayed in the whole area except in

  1. Growing season variability of net ecosystem CO2 exchange and evapotranspiration of a sphagnum mire in the broad-leaved forest zone of European Russia

    International Nuclear Information System (INIS)

    Olchev, A; Volkova, E; Karataeva, T; Novenko, E

    2013-01-01

    The spatial and temporal variability of net ecosystem exchange (NEE) of CO 2 and evapotranspiration (ET) of a karst-hole sphagnum peat mire situated at the boundary between broad-leaved and forest–steppe zones in the central part of European Russia in the Tula region was described using results from field measurements. NEE and ET were measured using a portable measuring system consisting of a transparent ventilated chamber combined with an infrared CO 2 /H 2 O analyzer, LI-840A (Li-Cor, USA) along a transect from the southern peripheral part of the mire to its center under sunny clear-sky weather conditions in the period from May to September of 2012 and in May 2013. The results of the field measurements showed significant spatial and temporal variability of NEE and ET that was mainly influenced by incoming solar radiation and ground water level. The seasonal patterns of NEE and ET within the mire were quite different. During the entire growing season the central part of the mire was a sink of CO 2 for the atmosphere. NEE reached maximal values in June–July (−6.8 ± 4.2 μmol m −2 s −1 ). The southern peripheral part of the mire, due to strong shading by the surrounding forest, was a sink of CO 2 for the atmosphere in June–July only. ET reached maximal values in the well-lighted central parts of the mire in May (0.34 ± 0.20 mm h −1 ) mainly because of high air and surface temperatures and the very wet upper peat horizon and sphagnum moss. Herbaceous species made the maximum contribution to the total gross primary production (GPP) in both the central and the peripheral parts of the mire. The contribution of sphagnum to the total GPP of these plant communities was relatively small and ranged on sunny days of July–August from −1.1 ± 1.1 mgC g −1 of dry weight (DW) per hour in the peripheral zone of the mire to −0.6 ± 0.2 mgC g −1 DW h −1 at the mire center. The sphagnum layer made the maximum contribution to total ET at the mire center (0

  2. Growing season methane emission from a boreal peatland in the continuous permafrost zone of Northeast China: effects of active layer depth and vegetation

    Directory of Open Access Journals (Sweden)

    Y. Miao

    2012-11-01

    Full Text Available Boreal peatlands are significant natural sources of methane and especially vulnerable to abrupt climate change. However, the controlling factors of CH4 emission in boreal peatlands are still unclear. In this study, we investigated CH4 fluxes and abiotic factors (temperature, water table depth, active layer depth, and dissolved CH4 concentrations in pore water during the growing seasons in 2010 and 2011 in both shrub-sphagnum- and sedge-dominated plant communities in the continuous permafrost zone of Northeast China. The objective of our study was to examine the effects of vegetation types and abiotic factors on CH4 fluxes from a boreal peatland. In an Eriophorum-dominated community, mean CH4 emissions were 1.02 and 0.80 mg m−2 h−1 in 2010 and 2011, respectively. CH4 fluxes (0.38 mg m−2 h−1 released from the shrub-mosses-dominated community were lower than that from Eriophorum-dominated community. Moreover, in the Eriophorum-dominated community, CH4 fluxes showed a significant temporal pattern with a peak value in late August in both 2010 and 2011. However, no distinct seasonal variation was observed in the CH4 flux in the shrub-mosses-dominated community. Interestingly, in both Eriophorum- and shrub-sphagnum-dominated communities, CH4 fluxes did not show close correlation with air or soil temperature and water table depth, whereas CH4 emissions correlated well to active layer depth and CH4 concentration in soil pore water, especially in the Eriophorum-dominated community. Our results suggest that CH4 released from the thawed CH4-rich permafrost layer may be a key factor controlling CH4 emissions in boreal peatlands, and highlight that CH4 fluxes vary with vegetation type in boreal peatlands. With

  3. Stem characteristics of two forage maize (Zea mays L.) cultivars varying in whole plant digestibility. IV. Changes during the growing season in anatomy and chemical composition in relation to fermentation characteristics of a lower internode

    NARCIS (Netherlands)

    Boon, E.J.M.C.; Struik, P.C.; Engels, F.M.; Cone, J.W.

    2012-01-01

    Improving digestibility of forage maize (Zea mays L.) through breeding is important to optimize the efficiency of ruminant's rations. It can partly be achieved by improving the digestibility of stem tissue, a genetically complex and diverse trait changing drastically during the growing season. We

  4. Development and validation of a learning progression for change of seasons, solar and lunar eclipses, and moon phases

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    Italo Testa

    2015-07-01

    Full Text Available In this paper, we report about the development and validation of a learning progression about the Celestial Motion big idea. 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 about change of seasons, solar and lunar eclipses, and Moon phases; then, a two-tier multiple choice questionnaire was designed to validate and improve them. The questionnaire was submitted to about 300 secondary students of different school levels (14 to 18 years old. Item response analysis and curve integral method were used to revise the hypothesized learning progressions. Findings support that spatial reasoning is a key cognitive factor for building an explanatory framework for the Celestial Motion big idea, but also suggest that causal reasoning based on physics mechanisms underlying the phenomena, as light flux laws or energy transfers, may significantly impact a students’ understanding. As an implication of the study, we propose that the teaching of the three discussed astronomy phenomena should follow a single teaching-learning path along the following sequence: (i emphasize from the beginning the geometrical aspects of the Sun-Moon-Earth system motion; (ii clarify consequences of the motion of the Sun-Moon-Earth system, as the changing solar radiation flow on the surface of Earth during the revolution around the Sun; (iii help students moving between different reference systems (Earth and space observer’s perspective to understand how Earth’s rotation and revolution can change the appearance of the Sun and Moon. Instructional and methodological implications are also briefly discussed.

  5. 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.

  6. Applicability of a “Multi-Stage Pulse Labeling” 15N Approach to Phenotype N Dynamics in Maize Plant Components during the Growing Season

    Directory of Open Access Journals (Sweden)

    Amanda de Oliveira Silva

    2017-08-01

    Full Text Available HighlightsThis work utilizes “multi-stage pulse labeling” 15N applications, primarily during reproductive growth stages, as a phenotyping strategy to identify maize hybrids with superior N use efficiency (NUE under low N conditions.Research using labeled isotopic N (15N can precisely quantify fertilizer nitrogen (N uptake and organ-specific N allocation in field crops such as maize (Zea mays L.. The overall research objective was to study plant N uptake patterns potentially correlated with N use efficiency (NUE in field-grown maize hybrids using a “multi-stage pulse labeling” 15N phenotyping strategy with an emphasis on the reproductive period. Five hybrids varying in NUE were compared under zero N fertilizer application (0N plus a moderate rate of 112 kg N ha−1 (112N in 2013 (2 locations and 2014 growing seasons. The equivalent of 3.2 (2013 to 2.1 (2014 kg of 15N ha−1, as labeled Ca(15NO32, was injected into soil on both sides of consecutive plants at multiple stages between V14 and R5. Aboveground plant biomass was primarily collected in short-term intervals (4–6 days after each 15N application in both years, and following a single long-term interval (at R6 after 15N injection at R1 in 2014. Averaged across hybrids and site-years, the moderate N rate (112N increased absolute 15N uptake at all stages; however, plants in the 0N treatment allocated proportionally more 15N to reproductive organs. Before flowering, short-term recovery of 15N (15Nrec totaled ~0.30 or 0.40 kg kg−1 of the 15N applied, and ~50% of that accumulated 15Nu was found in leaves and 40% in stems. After flowering, plant 15Nrec totaled ~0.30 kg kg−1 of 15N applied, and an average 30% of accumulated 15Nu was present in leaves, 17% in stems, and the remainder—usually the majority—in ears. At the R5 stage, despite a declining overall rate of 15N uptake per GDD thermal unit, plant 15Nrec represented ~0.25 kg kg−1 of 15N applied, of which ~65% was allocated

  7. Evaluation of rumen-protected choline additive to diet on productive performance of male Zaraibi growing goats during hot summer season in Egypt.

    Science.gov (United States)

    Habeeb, A A M; Gad, A E; Atta, M A A; Abdel-Hafez, M A M

    2017-08-01

    Twenty Zaraibi goat bucks were used in this experiment which lasted 3 months during summer season of Egypt. The animals were divided randomly into two equal groups. The first group was kept without treatment as control while in the second group, rumen-protected choline (RPC) at the level of 20 g/buck/day was added to the concentrate feed mixture at the morning feeding. RPC additives to diet of Zaraibi goat bucks during the period of hot summer season increased (P conversion while water intake was not affected by RPC additives. RPC increased (P goats, especially, under heat stress conditions of summer season in Egypt and showed the best results concerning the growth, feed conversion, blood metabolites, and economic efficiency.

  8. Dealing with Climate Change and Variability in the Growing Season: a U2U Decision Support Tool for Central United States Corn Producers Based on Corn Growing Degree Days

    Science.gov (United States)

    Angel, J. R.; Todey, D.; Massey, R.; Widhalm, M.; Biehl, L. L.; Andresen, J.

    2014-12-01

    Climate extremes are a major challenge for corn producers in the central United States. Among those extremes are wet springs that lead to planting delays, late spring and early fall frosts that can damage crops, and extreme summer temperatures either too warm or too cool. A newly-operational corn growing degree-day (CGDD) tool helps producers manage and adapt to these extremes. For example, a challenge in recent years has been exceptionally wet springs that have led to significant planting delays. Producers have been forced to re-assess their planting strategies on short notice, such as switching to a faster-growing but lower-yielding hybrids. With this pattern of wetter springs projected to continue or worsen in the central United States, the problem will remain and likely get worse. Another example is helping producers identify the risk of early or late frost/freezes. The CGDD tool puts current conditions into a 30-year historical perspective and offers trend projections (based on climatology or forecasts) through the end of the calendar year. Corn, or sometimes called modified, growing degree-days use a temperature base of 10 C (50 F) and a ceiling of 30 C (86 F) and is strongly correlated with the development of the corn crop. This tool was developed as part of USDA-supported U2U Useful to Usable Project for transforming climate variability and change information for cereal crop producers.

  9. EXPLORING THE CORRELATION BETWEEN SOUTHERN AFRICAN NDVI AND ENSO SEA SURFACE TEMPERATURES: RESULTS FOR THE 1998 MAIZE GROWING SEASON. (U915612)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  10. Effects of Urbanization and Seasonal Cycle on the Surface Urban Heat Island Patterns in the Coastal Growing Cities: A Case Study of Casablanca, Morocco

    Directory of Open Access Journals (Sweden)

    Hicham Bahi

    2016-10-01

    Full Text Available The urban heat island (UHI phenomenon is a harmful environmental problem in urban areas affecting both climatic and ecological processes. This paper aims to highlight and monitor the spatial distribution of Surface UHI (SUHI in the Casablanca region, Morocco, using remote sensing data. To achieve this goal, a time series of Landsat TM/ETM+/OLI-TIRS images was acquired from 1984 to 2016 and analyzed. In addition, nocturnal MODIS images acquired from 2005 to 2015 were used to evaluate the nighttime SUHI. In order to better analyze intense heat produced by urban core, SUHI intensity (SUHII was computed by quantifying the difference of land surface temperature (LST between urban and rural areas. The urban core SUHII appears more significant in winter seasons than during summer, while the pattern of SUHII becomes moderate during intermediate seasons. During winter, the average daytime SUHII gradually increased in the residential area of Casablanca and in some small peri-urban cities by more than 1 °C from 1984 to 2015. The industrial areas of the Casablanca region were affected by a significant rise in SUHII exceeding 15 °C in certain industrial localities. In contrast, daytime SUHII shows a reciprocal effect during summer with emergence of a heat island in rural areas and development of cool islands in urban and peri-urban areas. During nighttime, the SUHII remains positive in urban areas year-round with higher values in winter as compared to summer. The results point out that the seasonal cycle of daytime SUHII as observed in the Casablanca region is different from other mid-latitude cities, where the highest values are often observed in summer during the day.

  11. Xylogenesis: Coniferous Trees of Temperate Forests Are Listening to the Climate Tale during the Growing Season But Only Remember the Last Words!1

    Science.gov (United States)

    2016-01-01

    The complex inner mechanisms that create typical conifer tree-ring structure (i.e. the transition from large, thin-walled earlywood cells to narrow, thick-walled latewood cells) were recently unraveled. However, what physiological or environmental factors drive xylogenesis key processes remain unclear. Here, we aim to quantify the influence of seasonal variations in climatic factors on the spectacular changes in the kinetics of wood cell differentiation and in the resulting tree-ring structure. Wood formation was monitored in three sites over 3 years for three coniferous species (Norway spruce [Picea abies], Scots pine [Pinus sylvestris], and silver fir [Abies alba]). Cell differentiation rates and durations were calculated and related to tracheid final dimensions and corresponding climatic conditions. On the one hand, we found that the kinetics of cell enlargement and the final size of the tracheids were not explained by the seasonal changes in climatic factors. On the other hand, decreasing temperatures strongly constrained cell wall deposition rates during latewood formation. However, the influence of temperature was permanently written into tree-ring structure only for the very last latewood cells, when the collapse of the rate of wall deposition was no longer counterbalanced by the increase of its duration. Our results show that the formation of the typical conifer tree-ring structure, in normal climatic conditions, is only marginally driven by climate, suggesting strong developmental control of xylogenesis. The late breakage of the compensatory mechanism at work in the wall deposition process appears as a clue to understand the capacity of the maximum latewood density to record past temperature conditions. PMID:27208048

  12. Seasonal and annual variations of metal uptake, bioaccumulation, and toxicity in Trifolium repens and Lolium perenne growing in a heavy metal-contaminated field.

    Science.gov (United States)

    Bidar, Géraldine; Pruvot, Christelle; Garçon, Guillaume; Verdin, Anthony; Shirali, Pirouz; Douay, Francis

    2009-01-01

    The reclamation of nonferrous metal-polluted soil by phytoremediation requires an overall and permanent plant cover. To select the most suitable plant species, it is necessary to study metal effects on plants over the time, thereby checking that metals remain stored in root systems and not transferred to aerial parts. In this purpose, the seasonal and annual variations of metal bioaccumulation, transfer, and phytotoxicity in Trifolium repens and Lolium perenne grown in a Cd-, Pb-, and Zn-contaminated soil were also studied. The experimental site was located near a closed smelter. In spring 2004, two areas were sown with T. repens and L. perenne, respectively. Thereafter, the samplings of plant roots and shoots and surrounding soils were realized in autumn 2004 and spring and autumn 2005. The soil agronomic characteristics, the Cd, Pb, and Zn concentrations in the surrounded soils and plant organs, as well as the oxidative alterations (superoxide dismutase [SOD], malondialdehyde [MDA], and 8-hydroxy-2'-deoxyguanosine [8-OHdG]) in plant organs were carried out. Whatever the sampling period, metal concentrations in soils and plants were higher than background values. Contrary to the soils, the fluctuations of metal concentrations were observed in plant organs over the time. Bioaccumulation and transfer factors confirmed that metals were preferentially accumulated in the roots as follows: Cd>Zn>Pb, and their transfer to shoots was limited. Foliar metal deposition was also observed. The results showed that there were seasonal and annual variations of metal accumulation in the two studied plant species. These variations differed according to the organs and followed nearly the same pattern for the two species. Oxidative alterations were observed in plant organs with regard to SOD antioxidant activities, MDA, and 8-OHdG concentrations. These alterations vary according to the temporal variations of metal concentrations. Metal concentrations in surrounded soils and plant

  13. Intake, digestibility, nitrogen efficiency, and animal performance of growing and finishing beef cattle fed warm-season legume (Stylosanthes capitata plus Stylosanthes macrocephala) silage replacing corn silage.

    Science.gov (United States)

    Souza, W F; Pereira, O G; Ribeiro, K G; Santos, S A; Valadares Filho, S C

    2014-09-01

    It was hypothesized that Stylosanthes cv. Campo Grande (ES) silage could be used as the single source of dietary forage for beef cattle and that performance on ES would be similar to corn silage (CS) at a 50:50 forage:concentrate. The objectives of this study were to evaluate intake, total and partial digestibility of nutrients, ruminal pH, ruminal ammonia, and productive performance in growing beef cattle fed diets with varying proportions of ES silage replacing CS. Treatments consisted of diets with ratios of 0:100, 25:75, 50:50, 75:25, and 100:0% ES:CS. Two experiments were conducted simultaneously. In the first experiment, 10 crossbred Holstein-Zebu bulls with an average initial weight of 272 ± 86 kg were used. The bulls were rumen and abomasums fistulated. An experimental design of two 5 × 5 Latin squares (Exp. 1) was used. The second experiment used 40 Nellore bulls with an average BW of 386 ± 30 kg in a completely randomized design (Exp. 2). Results showed a linear increase in CP intake (P Nitrogen balance, excretion of urinary urea, and plasma urea nitrogen did not respond to the inclusion of ES in the diet (P > 0.05). There was also no effect (P > 0.05) of ES inclusion on animal performance. Ruminal pH was not affected by an increased proportion of ES in the diet (P > 0.05), but ruminal pH was affected (P interaction (P nitrogen concentration. It can be concluded that ES silage can be used as a source of roughage in the diet of beef cattle during the growing and finishing phases at a proportion of 50% of DM in the total diet. Therefore, ES silage is a promising alternative dietary ingredient and the use of this alternative source of silage will depend on availability and economic factors.

  14. Thermal conditions of the grape growing season within the North-Eastern steppe land of Ukraine (on the example of Kharkiv region

    Directory of Open Access Journals (Sweden)

    Борис Шуліка

    2016-10-01

    Full Text Available The article analyzes the results of the thermal conditions observations within the North-Eastern steppe land of Ukraine as one of the most important factors for successful cultivation of grapes, thus providing crop productivity. Considering the effect of thermal factors, it can be noted that the intensity and speed of life processes of plants are well- defined under temperature conditions only in the circumstances where other environmental factors are not limited. The thermal regime was initially taken into account in practice in XVII century. In XIX century the agro-climatic areas to grow grapes were determined in North-Eastern steppe land of Ukraine. Detailed studies of agro-climatic conditions of specific areas can more thoroughly to make conclusions and recommendations for the cultivation of grapes as a whole in the territory, and specifically in those areas were given. In studying the thermal balance of the territory the average and extreme temperature should be paid attention to. Characteristic features of the thermal regime are given in this paper based on the study of atmospheric phenomena, geomorphology and territories with radiation influence and water flow regime. Thermal treatment is subjected to anthropogenic influence, and in cultivating tenants can use appropriate agricultural practices (conceal bushes, warm soil and air, and even crops in protective ground, in greenhouses. Characteristically, technology of greenhouses growers is even used in Kherson region. These data can be used in neighborhood and the adjacent areas, especially they are useful for the practice of growing grapes. The possibility of successful cultivation of dozens of grape varieties in the North-Eastern steppe land of Ukraine has been well-grounded.

  15. Impacts of climate change on drought: changes to drier conditions at the beginning of the crop growing season in southern Brazil

    Directory of Open Access Journals (Sweden)

    Vânia Rosa Pereira

    2017-12-01

    Full Text Available ABSTRACT The intensification of drought incidence is one of the most important threats of the 21st century with significant effects on food security. Accordingly, there is a need to improve the understanding of the regional impacts of climate change on this hazard. This study assessed long-term trends in probability-based drought indices (Standardized Precipitation Index and Standardized Evapotranspiration Index in the State of São Paulo, Brazil. Owing to the multi-scalar nature of both indices, the analyses were performed at 1 to 12-month time scales. The indices were calculated by means of a relativist approach that allowed us to compare drought conditions from different periods. The years 1961-1990 were used as the referential period. To the authors’ best knowledge, this is the first time that such relativist approach is used in historical trend analysis. The results suggest that the evapotranspiration rates have intensified the regional drought conditions. The time scale used to calculate the indices significantly affected the outcomes of drought trend assessments. The reason behind this feature is that the significant changes in the monthly regional patterns are limited to a specific period of the year. More specifically, virtually all significant changes have been observed during the first trimester of the rainy season (October, November and December. Considering that this period corresponds to critical plant growth stages (flowering/regrowth/sprouting of several major crops (e.g. Sugarcane and Citrus, we may conclude that these significant changes have increased the risk of crop yield reductions due to agricultural drought.

  16. Rate of water infiltration into soil on a selected location at Žabčice during the growing season 2008

    Directory of Open Access Journals (Sweden)

    M. Vičanová

    2010-01-01

    Full Text Available Purpose of currently running research, which is part of research program Biological and technological aspects of sustainability of controlled ecosystems and their adaptability to climate change at Faculty of Agronomy, is mapping of progress in water infiltration on selected areas at Žabčice locality and to specify possibilities of a water accumulation and retention influence in a landscape.During of the first year of measurement (2008, from April to November, has proceeded field measurement of soil infiltration ability at Žabčice locality. To get statistically conclusive results, measurement runs in three repetitions and data are subsequently averaged. Three sets of homocentric metal cylinders were used for the measurement. Measurement of infiltration has been preceded by an overflow. Empirical equations according to Kosťjak were used for evaluation of field measurement.At the same time there were ensured intact soil samples for laboratory determination of soil physical properties using Kopecky cylinders at depths of 10, 20 and 30 cm, and for the calculation of selected hydro-physical parameters of soil.­ reduced volume weight, actual monture, porosity, aeration and other.Graphical presentation presents process of speed infiltration and cumulative infiltration on selected area Niva IV. A. Non-homogeneity of measured values could be induced by several different factors.

  17. Assessing Wheat Frost Risk with the Support of GIS: An Approach Coupling a Growing Season Meteorological Index and a Hybrid Fuzzy Neural Network Model

    Directory of Open Access Journals (Sweden)

    Yaojie Yue

    2016-12-01

    Full Text Available Crop frost, one kind of agro-meteorological disaster, often causes significant loss to agriculture. Thus, evaluating the risk of wheat frost aids scientific response to such disasters, which will ultimately promote food security. Therefore, this paper aims to propose an integrated risk assessment model of wheat frost, based on meteorological data and a hybrid fuzzy neural network model, taking China as an example. With the support of a geographic information system (GIS, a comprehensive method was put forward. Firstly, threshold temperatures of wheat frost at three growth stages were proposed, referring to phenology in different wheat growing areas and the meteorological standard of Degree of Crop Frost Damage (QX/T 88-2008. Secondly, a vulnerability curve illustrating the relationship between frost hazard intensity and wheat yield loss was worked out using hybrid fuzzy neural network model. Finally, the wheat frost risk was assessed in China. Results show that our proposed threshold temperatures are more suitable than using 0 °C in revealing the spatial pattern of frost occurrence, and hybrid fuzzy neural network model can further improve the accuracy of the vulnerability curve of wheat subject to frost with limited historical hazard records. Both these advantages ensure the precision of wheat frost risk assessment. In China, frost widely distributes in 85.00% of the total winter wheat planting area, but mainly to the north of 35°N; the southern boundary of wheat frost has moved northward, potentially because of the warming climate. There is a significant trend that suggests high risk areas will enlarge and gradually expand to the south, with the risk levels increasing from a return period of 2 years to 20 years. Among all wheat frost risk levels, the regions with loss rate ranges from 35.00% to 45.00% account for the largest area proportion, ranging from 58.60% to 63.27%. We argue that for wheat and other frost-affected crops, it is

  18. Development, Validation, and Interlaboratory Evaluation of a Quantitative Multiplexing Method To Assess Levels of Ten Endogenous Allergens in Soybean Seed and Its Application to Field Trials Spanning Three Growing Seasons.

    Science.gov (United States)

    Hill, Ryan C; Oman, Trent J; Wang, Xiujuan; Shan, Guomin; Schafer, Barry; Herman, Rod A; Tobias, Rowel; Shippar, Jeff; Malayappan, Bhaskar; Sheng, Li; Xu, Austin; Bradshaw, Jason

    2017-07-12

    As part of the regulatory approval process in Europe, comparison of endogenous soybean allergen levels between genetically engineered (GE) and non-GE plants has been requested. A quantitative multiplex analytical method using tandem mass spectrometry was developed and validated to measure 10 potential soybean allergens from soybean seed. The analytical method was implemented at six laboratories to demonstrate the robustness of the method and further applied to three soybean field studies across multiple growing seasons (including 21 non-GE soybean varieties) to assess the natural variation of allergen levels. The results show environmental factors contribute more than genetic factors to the large variation in allergen abundance (2- to 50-fold between environmental replicates) as well as a large contribution of Gly m 5 and Gly m 6 to the total allergen profile, calling into question the scientific rational for measurement of endogenous allergen levels between GE and non-GE varieties in the safety assessment.

  19. Progressive-overload whole-body vibration training as part of periodized, off-season strength training in trained women athletes.

    Science.gov (United States)

    Jones, Margaret T

    2014-09-01

    The purpose was to examine the effects of progressive-overload, whole-body vibration (WBV) training on strength and power as part of a 15-week periodized, strength training (ST) program. Eighteen collegiate women athletes with ≥1 year of ST and no prior WBV training participated in the crossover design. Random assignment to 1 of the 2 groups followed pretests of seated medicine ball throw (SMBT), single-leg hop for distance (LSLH, RSLH), countermovement jump (CMJ), 3 repetition maximum (3RM) front squat (FS), pull-up (PU), and 3RM bench press (BP). Whole-body vibration was two 3-week phases of dynamic and static hold body weight exercises administered 2 d·wk in ST sessions throughout the 15-week off-season program. Total WBV exposure was 6 minutes broken into 30-second bouts with 60-second rest (1:2 work-to-relief ratio). Exercises, frequency, and amplitude progressed in intensity from the first 3-week WBV training to the second 3-week phase. Repeated-measures analysis of variances were used to analyze the SMBT, CMJ, LSLH, RSLH, FS, PU, and BP tests. Alpha level was p ≤ 0.05. Front squat, LSLH, and RSLH increased (p = 0.001) from pre- to posttest; FS increased from mid- to posttest. Pull-up increased (p = 0.008) from pre- to posttest. Seated medicine ball throw and BP showed a trend of increased performance from pre- to posttest (p = 0.11). Two 3-week phases of periodized, progressive-overload WBV + ST training elicited gains in strength and power during a 15-week off-season program. Greatest improvements in performance tests occurred in the initial WBV phase. Implementing WBV in conjunction with ST appears to be more effective in the early phases of training.

  20. Morpho-agronomic traits of common bean landraces in two growing seasonsCaracterísticas morfo-agronômicas de cultivares crioulas de feijão comum em dois anos de cultivo

    Directory of Open Access Journals (Sweden)

    Cileide Maria Medeiros Coelho

    2010-02-01

    Full Text Available The objective of this work was to characterize the genetic diversity of landrace beans in two years for morphologic and agronomy characteristics. Twenty four bean (Phaseolus vulgaris L. genotypes were evaluated during the growing seasons of 2006/2007 and 2007/2008, using the randomized block design with three replications in Lages - SC. The genotypes were analyzed for 12 morphological and agronomic traits. The genotypes were studied using multivariable techniques to measure genetic divergence represented by the generalized distance of Mahalanobis and the genotypes grouping was performed by Tocher's optimization procedure. Among the 12 variables evaluated, the weight of 100 seeds had the highest contribution in the separation of the genotypes followed by the pod length in the two seasons. Genotypes BAF 3, BAF 37, BAF 42, BAF 55, BAF 57 and BAF 75 had high grain yield (around 4,000 Kg ha-1 in the two growing seasons and they could be incorporated in the programs of genetic breeding or used in the crop production.O objetivo deste trabalho foi caracterizar a diversidade de genótipos crioulos de feijão em dois anos de cultivo quanto às características morfoagronômicas. O experimento foi conduzido com 24 genótipos nas safras de 2006/2007 e 2007/2008 no município de Lages - SC, sob delineamento experimental em blocos ao acaso com 3 repetições, em que foram avaliadas 12 características morfológicas e agronômicas. Foi utilizada a técnica de análise multivariada para medir a divergência genética representada pela distância generalizada de Mahalanobis e o agrupamento dos genótipos foi realizado através do método de otimização de Tocher. Entre as 12 características avaliadas, o peso de 100 sementes foi o caráter que apresentou maior contribuição na separação dos genótipos, seguido pelo comprimento da vagem, nos dois anos de cultivo. Os genótipos BAF 3, BAF 37, BAF 42, BAF 55, BAF 57 e BAF 75 apresentaram elevados níveis de

  1. Growing container seedlings: Three considerations

    Science.gov (United States)

    Kas Dumroese; Thomas D. Landis

    2015-01-01

    The science of growing reforestation and conservation plants in containers has continually evolved, and three simple observations may greatly improve seedling quality. First, retaining stock in its original container for more than one growing season should be avoided. Second, strongly taprooted species now being grown as bareroot stock may be good candidates...

  2. Variação da composição química em cultivares de batata durante seu desenvolvimento Variation in the chemical composition of potato tubers of three cultivars during the growing season

    Directory of Open Access Journals (Sweden)

    Dayse Soave Spoladore

    1985-01-01

    Full Text Available Estudou-se no presente trabalho a dinâmica de acúmulo de substâncias de reserva e glicoalcalóides totais, durante o desenvolvimento de tubérculos de três cultivares de batata - Aracy (IAC-2, Itaiquara (IAC-3551 e Teberê (IAC-4489 - criados e selecionados pela Seção de Raízes e Tubérculos do Instituto Agronômico, no ano agrícola 1982/83, em plantio "das águas" (novembro-janeiro. Os resultados obtidos são referentes às amostragens realizadas aos 64, 79 e 111 dias após o plantio (DAP, e mostraram que o cultivar Aracy acumulou maior quantidade de matéria seca, proteínas, cinzas, polissacarídeos totais e açúcares solúveis por tubérculo.In the rain season of 1982-1983 (November-January, it was studied the dynamics of accumulation of reserve substances and total glycoalkaloids in growing tubers of the Brazilian potato cultivars Aracy (IAC-2, Itaiquara (IAC-355 1 and Teberê (IAC-4489. Data are related to three sampling dates, 64, 79 and 111 days after planting (DAP. Tubers of Aracy (IAC-2 had the highest dry matter, protein, ash, total polisacharides and soluble e sugar contenta.

  3. Host gut-derived probiotic bacteria promote hypertrophic muscle progression and upregulate growth-related gene expression of slow-growing Malaysian Mahseer Tor tambroides

    Directory of Open Access Journals (Sweden)

    Md Asaduzzaman

    2018-02-01

    Full Text Available In modern aquaculture, dietary supplementation of probiotics is a novel approach for enhancing growth performance of slow-growing fish. However, the actual role of probiotics in regulating muscle growth at cellular and molecular levels in fish still needs to be clarified. In this study, we hypothesized that host gut derived probiotic bacteria would enhance cellular muscle growth, and upregulate growth-related gene expression in slow-growing Malaysian mahseer Tor tambroides. Therefore, three host-associated probiotics (Bacillus sp. AHG22, Alcaligenes sp. AFG22, and Shewanella sp. AFG21 were isolated from the gastro-intestinal tract of T. tambroides and screened based on their digestive enzyme activity. A fishmeal and casein based control diet (40% crude protein and 10% lipid was formulated, and three different probiotic supplemented diets were prepared by immersing the control diet in each isolated host-derived bacteria, suspended in sterile phosphate buffered saline (PBS, to achieve a final concentration of approximately 1.0 × 108 CFU g−1 feed. Triplicate groups of T. tambroides juveniles (initial weight 1.39 ± 0.06 g were stocked in twelve glass aquaria (100 L capacity with stocking density of 20 individuals per aquarium. The feed was applied twice daily at 3.0% of the fish body weight per day for 90 days. Growth performance (weight gain and specific growth rate of T. tambroides juveniles were significantly higher in Alcaligenes sp. AFG22 and Bacillus sp. AHG22 supplemented diet treatments. Muscle morphometric analysis revealed that dietary supplementation of host-associated probiotic bacteria did not influence the frequency distribution of hyperplastic (class 10 small diameter fibers (≤10 μm. However, hypertrophic (Class 50, Class 60 and Class 70 large diameter fibers (>50 μm were significantly higher in Alcaligenes sp. AFG22 and Bacillus sp. AHG22 supplemented treatments, indicating that increased growth rate of T

  4. Direct costs associated with the management of progressive early onset scoliosis: estimations based on gold standard technique or with magnetically controlled growing rods.

    Science.gov (United States)

    Charroin, C; Abelin-Genevois, K; Cunin, V; Berthiller, J; Constant, H; Kohler, R; Aulagner, G; Serrier, H; Armoiry, X

    2014-09-01

    The main disadvantage of the surgical management of early onset scoliosis (EOS) using conventional growing rods is the need for iterative surgical procedures during childhood. The emergence of an innovative device using distraction-based magnetically controlled growing rods (MCGR) provides the opportunity to avoid such surgeries and therefore to improve the patient's quality of life. Despite the high cost of MCGR and considering its potential impact in reducing hospital stays, the use of MCGR could reduce medical resource consumption in a long-term view in comparison to traditional growing rod (TGR). A cost-simulation model was constructed to assess the incremental cost between the two strategies. The cost for each strategy was estimated based on probability of medical resource consumption determined from literature search as well as data from EOS patients treated in our centre. Some medical expenses were also estimated from expert interviews. The time horizon chosen was 4 years as from first surgical implantation. Costs were calculated in the perspective of the French sickness fund (using rates from year 2013) and were discounted by an annual rate of 4%. Sensitivity analyses were conducted to test model strength to various parameters. With a time horizon of 4 years, the estimated direct costs of TGR and MCGR strategies were 49,067 € and 42,752 €, respectively leading to an incremental costs of 6135 € in favour of MCGR strategy. In the first case, costs were mainly represented by hospital stays expenses (83.9%) whereas in the other the cost of MCGR contributed to 59.5% of the total amount. In the univariate sensitivity analysis, the tariffs of hospital stays, the tariffs of the MCG, and the frequency of distraction surgeries were the parameters with the most important impact on incremental cost. MCGR is a recent and promising innovation in the management of severe EOS. Besides improving the quality of life, its use in the treatment of severe EOS is likely to

  5. Filocrono em batateira afetado pelo tamanho do tubérculo-semente e pela época de cultivo Phyllocrono in potato affected by tuber-seed size and growing season

    Directory of Open Access Journals (Sweden)

    Nereu Augusto Streck

    2009-01-01

    Full Text Available O objetivo deste trabalho foi estimar o filocrono de plantas de batata da cultivar Asterix oriundas de diferentes tamanhos de tubérculos-semente, em duas épocas de cultivo em campo utilizando o conceito de graus-dia para o cálculo do filocrono. O experimento foi desenvolvido em Santa Maria (RS, na primavera de 2003 e no outono de 2004. Foram usados quatro tamanhos de tubérculos-semente da cultivar de batata Asterix: entre 2 e 4 cm, 4 e 6 cm, 6 e 8 cm e 8 e 10 cm. O filocrono (ºC dia folha-1 foi estimado pelo inverso do coeficiente angular da relação entre número de folhas na haste principal e a soma térmica calculada por três métodos: método 1 - considera apenas a temperatura base; método 2 - considera a temperatura base e a temperatura ótima, e método 3 - considera a temperatura base, a temperatura ótima e a temperatura máxima. O tamanho do tubérculo-semente não afetou o filocrono, mas o método de cálculo da soma térmica e a época de cultivo afetaram o filocrono da batateira cultivar Asterix. No método de cálculo da soma térmica a ser usado no filocrono da batateira cultivar Asterix, recomenda-se usar a temperatura base e a temperatura ótima, pois com este método, o filocrono foi similar entre as épocas de cultivo.The objective of this study was to estimate the phyllochron of the potato cultivar Asterix in plants derived from different tuber seed sizes in two field growing seasons using the concept of degrees-days for calculating the phyllochron. The experiment was conducted in Santa Maria, RS, during Spring 2003 and Fall 2004. Four classes of tuber-seed diameter of the potato cultivar Asterix were used: 2-4 cm, 4-6 cm, 6-8 cm and 8-10 cm. The phyllochron was estimated as the inverse of the slope of the linear regression of main stem leaves number against the thermal time calculated with three methods: method 1 - considering only the base temperature, method 2 - considering the base temperature and the optimum

  6. Growing Pains

    CERN Multimedia

    Katarina Anthony

    2013-01-01

    Heat expands and cold contracts: it’s a simple thermodynamic rule. But when temperatures swing from 300 K to near-absolute zero, this rule can mean a contraction of more than 80 metres across the LHC’s 27-km-long cryogenic system. Keeping this growth in check are compensators (a.k.a. bellows), which shrink and stretch in response to thermodynamic changes. Leak tests and X-rays now underway in the tunnel have revealed that these “joints” might be suffering from growing pains…   This 25-μm weld crack is thought to be the cause of the helium leaks. Prior to the LS1 warm-up, CERN’s cryogenic experts knew of two points in the machine’s cryogenic distribution system that were leaking helium. Fortunately, these leaks were sufficiently small, confined to known sub-sectors of the cryogenic line and – with help from the vacuum team (TE-VSC) – could easily be compensated for. But as the machine warmed up f...

  7. A Malthusian Model for all Seasons

    DEFF Research Database (Denmark)

    Sharp, Paul Richard; Weisdorf, Jacob Louis

    associated with labour shortages (the high-season bottleneck on production), although there might be labour surplus during the low season. We introduce the concept of seasonality into a stylized Malthusian model, and endogenize the extent of agricultural labour input, which is then used to calculate labour...... surplus and the rate of labour productivity. We observe the effects of season-specific technological progress, and find that technological progress in the low-season increases labour surplus and labour productivity whilst, perhaps surprisingly, technological progress in the high-season, by relaxing...... the high-season bottleneck, leads to work intensification and a drop in labour surplus and labour productivity...

  8. Rice herbicide monitoring in two Brazilian rivers during the rice growing season Monitoramento de herbicidas em dois rios brasileiros durante o período de cultivo do arroz

    Directory of Open Access Journals (Sweden)

    Enio Marchesan

    2007-01-01

    Full Text Available Irrigated rice production can involve environmental contamination with pesticides due to the proximity of the fields to rivers and to management problems. During three years (2000 to 2003 the rice herbicides clomazone, propanil and quinclorac were quantified in water during the rice growing season, in the Vacacaí and Vacacaí-Mirim Rivers, located in Rio Grande do Sul (RS State, Brazil. Water samples were taken at several locations in each river, selected by their importance in terms of rice drainage area. The samples were analyzed by HPLC-UV. At least one herbicide was detected in 41% of the samples from the Vacacaí River and 33% from the Vacacaí-Mirim River. The most frequent herbicide in both rivers and in each year was clomazone. The amount of herbicides in the river water was dependent on the rainfall regime. River water contamination by rice herbicides is probably caused by the rice water management used in the fields. The maintenance of flooded areas makes herbicides prone to contaminate the environment. To reduce the environmental contamination risk it is necessary to adopt measures to avoid overflow of flooded rice fields, keeping paddy water in the field for time enough to reduce the herbicide concentration before its release and enhancing the quality of the levees to reduce the probability of paddy rice overflow.No cultivo de arroz irrigado a possibilidade de contaminação dos mananciais hídricos é ampliada pelas características peculiares das áreas e do sistema de produção. Um estudo de monitoramento foi conduzido durante três anos (2000 a 2003, nos rios Vacacaí e Vacacaí-Mirim, localizados no Estado do Rio Grande do Sul, Brasil, buscando quantificar os herbicidas clomazone, propanil e quinclorac durante o período de cultivo do arroz. As amostras de água foram coletadas em vários locais em cada rio. Os locais de coleta foram selecionados pela importância em termos da captação da água de drenagem. As amostras foram

  9. Composição físico-química de uvas para vinho fino em ciclos de verão e inverno Physico-chemical composition of wine grapes berries in summer and winter growing seasons

    Directory of Open Access Journals (Sweden)

    Renata Vieira da Mota

    2010-12-01

    Full Text Available Este trabalho teve como objetivo avaliar o potencial de maturação das cultivares Pinot Noir, Tempranillo, Merlot, Cabernet Sauvignon, Syrah, Chardonnay e Sauvignon Blanc submetidas ao regime de dupla poda, em Cordislândia, região cafeeira do sul de Minas Gerais. As plantas foram submetidas a dois ciclos de produção, um de primavera-verão, compreendido entre agosto e janeiro, e outro ciclo de outono-inverno, entre janeiro e julho. Como parâmetros de qualidade, foram avaliados os diâmetros transversal e longitudinal da baga, acidez, ácidos tartárico e málico, pH, sólidos solúveis, antocianinas, fenólicos totais e os teores de glicose, frutose e sacarose. Todas as variedades apresentaram maiores teores de pH, sólidos solúveis, açúcares, antocianinas e fenólicos totais, e redução nos diâmetros transversal e longitudinal na safra de inverno. A cultivar Syrah destacou-se das demais no conteúdo de antocianinas e fenólicos totais tanto no verão quanto no inverno, entretanto apresentou o menor conteúdo de açúcares. A alteração do ciclo de produção da videira através da técnica da dupla poda para colheita, no período de inverno, na região cafeeira de Minas Gerais, favorece a maturação dos frutos e melhora consideravelmente a qualidade das uvas para vinificação.This work aimed to evaluate some ripening parameters of cultivars Pinot Noir, Tempranillo, Merlot, Cabernet Sauvignon, Syrah, Chardonnay and Sauvignon Blanc submitted to the double-pruning management in Cordislândia, in the coffee region of the south of Minas Gerais State. Grapevines were cultivated in two different growing seasons, spring-summer from August to January and autumn-winter from January to July. Quality parameters such as berry transversal and longitudinal diameters, acidity, tartaric and malic acids, pH, soluble solids, anthocyanins, phenolic compounds, glucose, fructose and sucrose were evaluated. All cultivars showed higher pH, soluble solids

  10. Sugarcane crop efficiency in two growing seasons in São Paulo State, Brazil Eficiência da produção de cana-de-açúcar em duas safras no Estado de São Paulo

    Directory of Open Access Journals (Sweden)

    Fábio Ricardo Marin

    2008-11-01

    Full Text Available A conceptual framework for crop production efficiency was derived using thermodynamic efficiency concept, in order to generate a tool for performance evaluation of agricultural systems and to quantify the interference of determining factors on this performance. In Thermodynamics, efficiency is the ratio between the output and input of energy. To establish this relationship in agricultural systems, it was assumed that the input energy is represented by the attainable crop yield, as predicted through simulation models based on environmental variables. The method of FAO's agroecological zones was applied to the assessment of the attainable sugarcane yield, while Instituto Brasileiro de Geografia e Estatística (IBGE data were used as observed yield. Sugarcane efficiency production in São Paulo state was evaluated in two growing seasons, and its correlation with some physical factors that regulate production was calculated. A strong relationship was identified between crop production efficiency and soil aptitude. This allowed inferring the effect of agribusiness factors on crop production efficiency. The relationships between production efficiency and climatic variables were also quantified and indicated that solar radiation, annual rainfall, water deficiency, and maximum air temperature are the main factors affecting the sugarcane production efficiency.Um conceito de eficiência de produção agrícola foi derivado da Termodinâmica, para gerar um indicador para avaliação do desempenho de sistemas de produção agrícola e quantificação da interferência dos fatores determinantes desse desempenho. Em Termodinâmica, a eficiência de um processo é dada pela razão entre a energia recuperada e a energia utilizada. Para estabelecer essa relação em sistemas agrícolas, admitiu-se que a energia utilizada seja dada pela produtividade atingível, estimada por modelos de simulação desenvolvidos com base em variáveis ambientais. O método das

  11. GENETIC DIVERGENCE AMONG COTTON GENOTYPES GROWN IN THE MAIN SEASON AND OFF SEASON

    Directory of Open Access Journals (Sweden)

    THIAGO ALEXANDRE SANTANA GILIO

    2017-01-01

    Full Text Available The objective of this work was to evaluate the agronomic performance and estimate the genetic divergence of 18 cotton genotypes grown in the main season (sowed in December, 2012 and off season (sowed in January, 2013, considering their agronomic characteristics and resistance to Ramularia leaf spot. A randomized block experimental design was used, with five replications. The characteristics evaluated were plant height, first branch height, position of first fruiting branch, height of first fruiting branch, length between nodes, number of nodes, average number of bolls per plant, average boll weight, area under the disease progress curve (AUDPC related to the Ramularia leaf spot severity, weight of 100 - seed from the plant middle third, fiber percentage, average production per plant, yield and cotton fiber quality. The results were subjected to individual and joint analysis of variance and the genetic divergence was estimated according to multivariate procedures (Mahalanobis' generalized distance and Tocher's optimization method. The dissimilarity matrices were summed to estimate the genetic divergence, considering both growing periods. Genetic variability was found among the genotypes evaluated, in both the main season and off season. The characteristic that most contributed to the genetic divergence in the main season was the production per plant and, in the off season, was the fiber percentage. According to the results of the present work, the crosses between the genotypes BRS - 335 and FMT - 707; FM - 910 and FMT - 707; and IMA - 08 - 12427 and FMT - 707 are recommended.

  12. 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.

    NARCIS (Netherlands)

    Tsyganov, A.N.; Aerts, R.; Nijs, I.; Cornelissen, J.H.C.; Beyens, L.

    2012-01-01

    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,

  13. STAGE-DEPENDENCE, SEASONAL CHANGES AND EFFECTS OF CADMIUM ON CELL CYCLE AND APOPTOTIC ACTIVITIES DURING THE SPERMATOGENIC PROGRESSION IN THE DOGFISH SHARK (SQUALUS ACANTHIAS). (R825434)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. Seasonal progression of atmospheric particulate matter over an urban coastal region in peninsular India: Role of local meteorology and long-range transport

    Science.gov (United States)

    Mahapatra, P. S.; Sinha, P. R.; Boopathy, R.; Das, T.; Mohanty, S.; Sahu, S. C.; Gurjar, B. R.

    2018-01-01

    Measurement of particulate matter (PM) over an urban site with relatively high concentration of aerosol particles is critically important owing to its adverse health, environmental and climate impact. Here we present a 3 years' worth of measurements (January 2012 to December 2014) of PM2.5 (aerodynamic diameter of less than 2.5 μm) and PM10 (aerodynamic diameter of less than 10 μm) along with meteorological parameters and seasonal variations at Bhubaneswar an urban-coastal site, in eastern India. The concentrations of PM were determined gravimetrically from the filter samples of PM2.5 and PM10. It revealed remarkable seasonal variations with winter values (55.0 ± 23.4 μg/m3; 147.3 ± 42.4 μg/m3 for PM2.5 and PM10, respectively) about 3.5 times higher than that in pre-monsoon (15.7 ± 6.2 μg/m3; 41.8 ± 15.3 μg/m3). PM2.5 and PM10 were well correlated while PM2.5/PM10 ratios were found to be 0.38 and 0.32 during winter and pre-monsoon, indicating the predominance of coarse particles, mainly originating from long range transport of pollutants from northern and western parts of India and parts of west Asia as well. Concentration weighted trajectory (CWT) analysis revealed the IGP and North Western Odisha as the most potential sources of PM2.5 and PM10 during winter. The PM concentrations at Bhubaneswar were comparable with those at other coastal sites of India reported in the literature, but were lower than few polluted urban sites in India and Asia. Empirical model reproduced the observed seasonal variation of PM2.5 and PM10 very well over Bhubaneswar.

  15. Growing media [Chapter 5

    Science.gov (United States)

    Douglass F. Jacobs; Thomas D. Landis; Tara Luna

    2009-01-01

    Selecting the proper growing medium is one of the most important considerations in nursery plant production. A growing medium can be defined as a substance through which roots grow and extract water and nutrients. In native plant nurseries, a growing medium can consist of native soil but is more commonly an "artificial soil" composed of materials such as peat...

  16. Population dinamic of snap bean pests on four growing seasons and its influence on productive parameters / Flutuação populacional de insetos associados ao feijão-vagem c.v. UEL-1 em quatro épocas de plantio e seu efeito sobre as características produtivas

    Directory of Open Access Journals (Sweden)

    Ronaldo Mitsuo Takada

    2003-05-01

    Full Text Available Insect pests of snap beans in northern Paraná state – Brazil were monitored during four growing seasons: March – May, May – June, August – September, September – November. Adults of leafhopper (Empoasca kraemeri, whiteffly (Bemisia tabaci and corn rootworm (Diabrotica speciosa were monitored weekly using a cone trap. Leafhoppers nymphs were counted in mid height trifoliate leaves. The productive parameters evaluated in harvesting were: number of pods / plant; number of marketable pods; number of damaged pods divided in bent pods, empty pods or bored pods. Insect infestation were lower in August – September growing period, which yielded higher percent of marketable pods. The highest population of leafhopper occurred in March – May period, when the percent of curved pods were also the highest. Maximum population of whitefly occurred in early season of March – May growing period. Leaf beetle (D. speciosa population did not surpass de damage threshold in any growing period, but was higher in March – May season.Objetivou-se conhecer a flutuação populacional dos principais insetos que atacam a cultura do feijãovagem UEL-1 cultivado em diferentes épocas, e seu efeito sobre as características das vagens. Os plantios foram conduzidos na fazenda-escola da Universidade Estadual de Londrina, em quatro diferentes períodos: março-maio; maio-junho; agosto-setembro; setembro-novembro. Foram avaliados semanalmente os adultos da cigarrinha-verde (Empoasca kraemeri, mosca-branca (Bemisia tabaci e vaquinha (Diabrotica speciosa com auxílio de cone entomológico. Contagens de ninfas de E. kraemeri foram realizadas em trifólios do estrato médio da planta. Ao final de cada safra, avaliou-se o número de vagens/planta, de vagens com tamanho comercial, de vagens encurvadas, chochas e perfuradas. As menores populações de insetos ocorreram no plantio de agosto-setembro, quando obteve-se maior porcentagem de vagens com qualidade comercial

  17. Soil bacteria help Ethiopian farmers grow more nutritious and higher ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2013-01-11

    Jan 11, 2013 ... Rhizobia are able to extract atmospheric nitrogen found in the soil and convert it into a usable form for plants. These microorganisms provide ample nitrogen for growing protein-rich pulse crops, and may leave some left over for the next growing season of cereal and root crops. “If your goal is to grow protein ...

  18. Protein and energy supplementation for growing steers, in dry season Suplementação proteica e energética para novilhos em recria, durante o período da seca

    Directory of Open Access Journals (Sweden)

    Dorismar David Alves

    2010-12-01

    Full Text Available Dry matter intake, ruminal pH and ammonia concentration of grazing growing steers during the dry period, receiving different supplementation levels, were evaluated. Five rumen fistulated steers, with 18 months of age, 322kg average body weight were used in a 5x5 Latin Square design. The treatments used were based on the daily supplement supply of 0 (control - without supplementation; 0.125; 0.25; 0.5 and 1.0% of body weight. The dry matter intake was determined by the relationship between the fecal dry matter excreted estimated with external (Cr2O3 and internal (iADF markers. The rumen fluid was sampled at 0, 3, 6 and 9 hours after feeding the supplement for pH and ammonia determination. The forage intake by the control group was of 4.81kg DM/day; equivalent at 0.244% of available forage. The reduction of forage intake was more evident for the supplementation level of 1.0% of BW (1.44 kg/day, without affecting the average daily gain of the animals. Ruminal pH was higher for control treatment, averaging 7.3. The smallest value observed was 6.38 for 1.0% of BW supplementation level. The ammonia nitrogen presented higher averages at 3 hours after supplementation for level 0.5% of BW (21.53 mg/dL. Protein supply and protein-energy supplementation does not reduce the total dry matter intake of animals, but dry matter intake of herbage.Avaliou-se a suplementação proteica e proteica energética no consumo de matéria seca e nos parâmetros ruminais (pH e N-NH3 de novilhos recriados a pasto, durante a seca. Foram utilizados cinco novilhos providos de cânulas ruminais, com 18 meses de idade e peso inicial de 322kg, distribuídos em esquema de quadrado latino 5x5. Os tratamentos utilizados foram 0,00 (controle; 0,125; 0,250; 0,500; 1,00% do peso vivo (PV de quantidade de suplementos. O consumo de matéria seca foi determinado por meio da relação entre a quantidade de matéria seca fecal excretada, com o uso de indicador externo (Cr2O3 e interno (FDAi

  19. Growing Hemorrhagic Choroidal Fissure Cyst.

    Science.gov (United States)

    Karatas, Ayse; Gelal, Fazıl; Gurkan, Gokhan; Feran, Hamit

    2016-03-01

    Choroidal fissure cysts are often incidentally discovered. They are usually asymptomatic. The authors report a case of growing and hemorrhagic choroidal fissure cyst which was treated surgically. A 22-year-old female presented with headache. Cranial MRI showed a left-sided choroidal fissure cyst. Follow-up MRI showed that the size of the cyst had increased gradually. Twenty months later, the patient was admitted to our emergency department with severe headache. MRI and CT showed an intracystic hematoma. Although such cysts usually have a benign course without symptoms and progression, they may rarely present with intracystic hemorrhage, enlargement of the cyst and increasing symptomatology.

  20. Envelhecimento fisiológico de tubérculos de batata produzidos durante o outono e a primavera e armazenados em diferentes temperaturas Physiological aging of potato tubers produced during fall and spring growing seasons and stored under different temperatures

    Directory of Open Access Journals (Sweden)

    Dilson Antônio Bisognin

    2008-01-01

    Full Text Available O armazenamento adequado dos tubérculos é muito importante para manter o equilíbrio da oferta de batata no mercado e para a obtenção de tubérculos-semente em adequado estádio fisiológico no momento do plantio. O objetivo deste trabalho foi determinar o efeito de diferentes temperaturas de armazenagem no envelhecimento fisiológico de tubérculos de três clones de batata produzidos durante o outono e a primavera. O experimento foi desenvolvido em um fatorial de três clones (Asterix, SMIJ461-1 e SMINIA793101-3 por quatro temperaturas de armazenamento (4, 8, 12 e 25 ºC e duas épocas de plantio (outono e primavera no delineamento experimental inteiramente casualizado, com quatro repetições. As avaliações foram em intervalos de 30 dias, do início até os 180 dias de armazenamento. O armazenamento refrigerado prolongou a dormência dos tubérculos, reduzindo o número de brotos e evitando o apodrecimento; as temperaturas de 4 e 8 ºC impediram a brotação dos tubérculos produzidos no outono. A perda de massa fresca e a respiração dos tubérculos aumentaram com o tempo e a temperatura de armazenamento. A época de plantio altera o comportamento fisiológico dos tubérculos durante o armazenamento. O armazenamento à baixa temperatura (4 e 8 ºC é eficaz para retardar o envelhecimento fisiológico.Adequate tuber storage is necessary to maintain a good availability of potato tubers in the market and to get seeds with adequate physiological age at planting. The objective of this work was to determine the effect of different storage temperatures on tuber physiological aging of three potato clones produced during fall and spring growing seasons. The experiment was carried out as factorial of three clones (Asterix, SMIJ461-1 and SMINIA793101-3 by four storage temperatures (4, 8, 12 and 25 ºC and two growing seasons (fall and spring in a random design with four replications. At 30-day intervals, tubers were evaluated from the beginning

  1. Assessment of the Growing Season Regime Region of Tanzania ...

    African Journals Online (AJOL)

    Centra\\,. Tanzania is 'a semi - arid region with some, parts .' receiving annual rainf~fl of less than 400 mm. The major annual crops: grown in the unimodal. 17. rainfall region include cereals (maize, millet, . and sorghum) and Jmlses(beans). Millet and sorghum are .grown in semi-arid areas of central Tanzania, where 0.

  2. Effects of Temperature and Growing Seasons on Crop Water ...

    African Journals Online (AJOL)

    PROF HORSFALL

    143. FAO (Food and Agriculture Organization) (2009). Irrigation in the Middle East region in figures. FAO Water Reports 34, Rome. FAO (Food and Agriculture Organization). (2012). CLIMWAT: A climatic database for irrigation planning and.

  3. Chemical variation in Jacobaea vulgaris is influenced by the interaction of season and vegetation successional stage.

    Science.gov (United States)

    Carvalho, Sabrina; Macel, Mirka; Mulder, Patrick P J; Skidmore, Andrew; van der Putten, Wim H

    2014-03-01

    Knowledge on spatio-temporal dynamics of plant primary and secondary chemistry under natural conditions is important to assess how plant defence varies in real field conditions. Plant primary and secondary chemistry is known to vary with both season and vegetation successional stage, however, in few studies these two sources of variation have been examined in combination. Here we examine variations in primary and secondary chemistry of Jacobaea vulgaris (Asteraceae) throughout the growing season in early, mid, and late stages of secondary succession following land abandonment using a well-established chronosequence in The Netherlands. We investigated primary and secondary chemistry of both leaves and flowers, in order to determine if patterns during seasonal (phenological) development may differ among successional stages. The chemical concentration of primary and secondary chemistry compounds in J. vulgaris varied throughout the season and was affected by vegetation succession stage. Concentrations of pyrrolizidine alkaloid (PA) tertiary-amines were highest in flowers during early Summer and in fields that had been abandoned ten to twenty years ago. PA N-oxide concentrations of both leaves and flowers, on the other hand increased with the progression of both season and succession. In Spring and early Summer chlorophyll concentrations were highest, especially in the oldest fields of the chronosequence. During phenological development, nitrogen concentration increased in flowers and decreased in leaves revealing allocation of nutrients from vegetative to reproductive plant parts throughout the growing season. The highest concentrations of N-oxides and chlorophylls were detected in older fields. Thus, our results suggest that variations in plant patterns of nutritional and defence compounds throughout the growing season are depending on successional context. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Comportamento produtivo da videira 'Niagara Rosada' em diferentes sistemas de condução, com e sem cobertura plástica, durante as safras de inverno e de verão Evaluation of vertical and "y" training systems and overhead plastic cover on 'Niagara Rosada' grape yield, during summer and winter growing seasons

    Directory of Open Access Journals (Sweden)

    José Luiz Hernandes

    2013-03-01

    growing seasons: summer (2008 and 2009 and winter (2009 and 2010 showed that the Y shaped system allows obtaining higher yields and larger size of clusters when compared to the vertical trellis system. The plastic overhead cover on the Y shaped system increased yield and cluster weight. It was also found that yield and cluster weight were higher for the summer growing season when compared to the winter crop.

  5. WHEN COMPASSION GROWS WINGS

    African Journals Online (AJOL)

    Nicky

    antiretroviral roll-out in full swing, the. WHEN COMPASSION GROWS WINGS. The free time and expertise given by its deeply committed core of professional volunteers. (including pilots) is the lifeblood of the operation. Red Cross Air Mercy Service volunteer, German national Dr Florian Funk, at the AMS Durban base.

  6. Growing Plants and Minds

    Science.gov (United States)

    Presser, Ashley Lewis; Kamdar, Danae; Vidiksis, Regan; Goldstein, Marion; Dominguez, Ximena; Orr, Jillian

    2017-01-01

    Many preschool classrooms explore plant growth. However, because many plants take a long time to grow, it is often hard to facilitate engagement in some practices (i.e., since change is typically not observable from one day to another, children often forget their prior predictions or cannot recall what plants looked like days or weeks earlier).…

  7. Desempenho de novilhos em crescimento em pastagem de Brachiaria decumbens suplementados com diferentes fontes energéticas no período da seca e transição seca-águas Development of growing steers on Brachiaria decumbens supplemented with different energy sources during the dry season and transition from dry to wet season

    Directory of Open Access Journals (Sweden)

    Jocilaine Garcia

    2004-12-01

    Full Text Available Objetivou-se, neste trabalho, estudar o efeito da suplementação, com diferentes fontes energéticas, sobre o desempenho de novilhos em crescimento e a viabilidade econômica da suplementação, bem como avaliar a disponibilidade e composição química da braquiária (Brachiaria decumbens Stapf, no período de julho a novembro, na região Oeste do Estado de São Paulo. Foram utilizados 42 novilhos da raça Nelore, distribuídos em três piquetes de 7,2 ha cada. As fontes energéticas utilizadas como suplementos foram: milho desintegrado com palha e sabugo (MDPS, farinha de mandioca de varredura (FMV e casca do grão de soja (CGS. Todos os tratamentos continham farelo de algodão, para atingir 25% de PB, e foram fornecidos em nível de 1,3% do PV. As pesagens dos animais foram realizadas a cada 14 dias e a disponibilidade de forragem foi estimada a cada 28 dias. A disponibilidade média de forragem foi de 2.570 kg de MS/ha e 1.306 kg de lâmina foliar/ha. A proporção de lâmina foliar apresentou comportamento quadrático em função do período experimental, com valor mínimo de 46,58%, observado em agosto. Os teores médios de proteína bruta foram de: 4,45% para planta inteira; 5,30% para lâmina foliar e 2,83% para o colmo + bainha. Os teores médios de FDN e FDA foram, respectivamente, de 70,61% e 39,93% para a planta inteira; 65,76% e 34,91% para a lâmina foliar e 75,83% e 47,90% para o colmo + bainha. Entre os suplementos não houve diferença para ganho médio diário, apresentando média de 0,836 kg/animal/dia. O suplemento mais viável economicamente foi o que continha a farinha de mandioca de varredura, pois, além de apresentar menor custo, foi o que proporcionou maior ganho animal, mostrando melhor relação receita: custo.The aim of this work was evaluate the effect of supplementation with different energetic sources, on growing steers performance and economical viability, and also evaluate the structure and chemical composition

  8. Growing up with Retinoblastoma

    Science.gov (United States)

    Maley, Tom

    2005-01-01

    An account is given of growing up as a child blinded as a result of a cancer of the eye known as retinoblastoma. The role of his mother is brought out, variously as a source of objective knowledge, of one's personal worth, and of the worth of other people in one's community. The strengths and weaknesses of his first school in his home area and…

  9. Incremento na densidade de plantas: uma alternativa para aumentar o rendimento de grãos de milho em regiões de curta estação estival de crescimento Increment on plant density: an alternative to improve maize grain yield in short growing season regions

    Directory of Open Access Journals (Sweden)

    Milton Luiz de Almeida

    2000-03-01

    Full Text Available O surgimento de novos cultivares de milho, de ciclo mais curto, estatura reduzida, menor número de folhas e folhas mais eretas aumentou o potencial de resposta da cultura à densidade de plantas. Essa tendência pode ser acentuada nos planaltos do Sul do Brasil, que apresentam temperatura média nos meses mais quentes inferiores a 22°C, o que resulta em menor estação estival de crescimento. Quatro experimentos foram conduzidos objetivando avaliar a viabilidade de se trabalhar com densidade de plantas maiores do que as atualmente recomendadas para esta região, como uma forma de aumentar o rendimento de grãos. Nestes experimentos, submeteram-se os híbridos Cargill 901 e XL 370 a uma população que variou de 37.000 a 100.000pl ha-1, sob diferentes situações de manejo. Em três dos quatro experimentos realizados, o uso de densidade de plantas superior a 60.000plha-1 maximizou o rendimento de grãos. A maior competição intraespecífica verificada nas densidades mais elevadas não reduziu drasticamente o número de espigas por planta, o que contribuiu para a melhor adaptação da cultura a densidades elevadas. Dessa forma, para locais com estação estival de crescimento mais curta, o uso de cultivares precoces, de menor porte, pode ser acompanhado pelo incremento na densidade para valores compreendidos entre 65.000 e 80.000pl ha-1. Isso é possível desde que se tenha bom nível de fertilidade no solo, boa disponibilidade hídrica e cultivares resistentes ao acamamento.The development of earlier hybrids, with shorter plant height, lower leaf number and upright leaves has increased maize potential adaptability to withstand high plant densities. This trend may be emphasized on the high lands of Southern Brazil due to their mild Spring and Summer temperatures and shorter maize growing season. Four trials were carried out, aiming to investigate the viability of using higher than recommended plant populations, as an alternative to improve

  10. Adubação orgânica da batata com esterco e, ou, Crotalaria juncea: II - disponibilidade de N, P e K no solo ao longo do ciclo de cultivo Organic fertilization of potato with manure and, or, Crotalaria juncea: II - soil N, P, and K availability throughout the growing season

    Directory of Open Access Journals (Sweden)

    Tácio Oliveira da Silva

    2007-02-01

    imobilização de N do solo nas primeiras semanas. O tratamento C aumentou o teor de N mineral do solo no período imediatamente após a incorporação, mas não aumentou o teor de P e K extraíveis. No ensaio em casa de vegetação, o capim-buffel acumulou mais biomassa aérea e nutrientes no primeiro corte, 35 dias após o transplantio do capim, no solo do tratamento CE. Nos cortes subseqüentes, o tratamento E levou à maior produção de biomassa e acumulação de nutrientes, indicando que a limitação de N no período inicial após a incorporação de esterco ao solo prejudicou o crescimento do buffel. Os resultados corroboram a hipótese de que o plantio e incorporação da crotalária, combinado com a aplicação de apenas a metade da dose usual de esterco caprino, promoveu mineralização de nutrientes mais sincronizada com as necessidades das culturas agrícolas, pois foi capaz de evitar a imobilização de N do solo no período inicial de cultivo e elevou os teores de P e K disponíveis ao longo de todo o período.Soil fertility levels in the Agreste region, state of Paraíba, Brazil are generally low. Usually, animal manure is applied to soils to supply agricultural crops with nutrients. However, depending on the quality of the manure applied, incorporation can lead to soil nitrogen immobilization in the beginning of the growing season. It was hypothesized that planting and incorporating crotalaria (Crotalaria juncea together with animal manure could synchronize the nutrient mineralization pattern more specifically with crop demand. In 2003, field and green-house experiments were carried out to test this hypothesis. Prior to the current study, the field plots were cultivated with potato from 1996 to 2002 and subjected annually to the following organic fertilization treatments: planting and incorporation of crotalaria during flowering (C; manure incorporation, 15 t ha-1 (E; planting and incorporation of crotalaria + 7.5 t ha-1 manure (CE; and control plots (T

  11. Growing hairs in shorn cattle

    Directory of Open Access Journals (Sweden)

    Cecília José Veríssimo

    2013-12-01

    10, hair decreased from average 21.26 ± 5.72 mm to 4.50 ± 0.83 mm. On the sheared side a hair growth of 26 mm was observed during the first two weeks, increasing to 40 mm for the next two weeks and at the end of 28 days there was still a significant difference (Z= -3.195; P= 0.001 for the non sheared hair (19.42 ± 7.33 mm and sheared hair (11.15 ± 3.23 mm. Such procedure was done by the beginning of August, still winter time. Using the blade size 30, sheared hair had an average of 4.76 ± 1.1 mm. A 24 mm hair growth was observed for the first two weeks and 20 mm for the next two weeks, decreasing its growth speed to 9 mm and after 57 days no significant difference was observed between sheared side (11.47 ± 5.61 mm and non sheared side (14.78 ± 8.06 mm, Z= -1.915; P= 0.055. Second cut was performed by  the beginning of October, spring time, period where there is a change of hair in European cattle  from winter season (thin and long hair to summer season (thick and short hair, starting on spring time. In this work we could observe the fast growing of hair when cut was done in winter time and the closer to the skin the better the benefits to the animals, as heat tolerance and fewer tick infestations. If shearing is done in spring time, it must be every 45-50 days.

  12. Temporomandibular Joint Reconstruction in the Growing Child.

    Science.gov (United States)

    Resnick, Cory M

    2018-02-01

    Indications and considerations for reconstruction of the temporomandibular joint (TMJ) differ between growing and skeletally mature patients. Osteoarthritis, which is the most common cause of TMJ destruction in adults, is comparatively rare in children. The most common indications in young patients are congenital deformities, pathology, ankylosis and progressive resorptive processes. Options for reconstruction include distraction osteogenesis, autologous reconstruction (ie, costochondral graft, free fibula flap), and total alloplastic joint replacement. The choice of the ideal reconstruction is based on multiple factors, which include extent and laterality of the deformity, patient age, jaw growth pattern, and potential for progressive destruction. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Growing Data User Communities

    Science.gov (United States)

    Wiggin, B.

    2017-12-01

    Preserving data is not only a technical challenge. Perhaps the best way to protect data is to use it. Grassroots efforts to make research-quality copies of federal data continue to energize communities of data users who often did not previously recognize themselves as open earth data users. Beyond "data rescue" events, the Data Refuge project researches how federal climate and environmental data are used downstream in a variety of local communities and municipal governments to address everyday issues: public health, municipal safety, and even the preservation of cultural heritage assets. Documenting the diverse uses made of open earth data beyond the earth sciences research community grows the community who, in making use of data, also helps to preserve it.

  14. Growing a market economy

    Energy Technology Data Exchange (ETDEWEB)

    Basu, N.; Pryor, R.J.

    1997-09-01

    This report presents a microsimulation model of a transition economy. Transition is defined as the process of moving from a state-enterprise economy to a market economy. The emphasis is on growing a market economy starting from basic microprinciples. The model described in this report extends and modifies the capabilities of Aspen, a new agent-based model that is being developed at Sandia National Laboratories on a massively parallel Paragon computer. Aspen is significantly different from traditional models of the economy. Aspen`s emphasis on disequilibrium growth paths, its analysis based on evolution and emergent behavior rather than on a mechanistic view of society, and its use of learning algorithms to simulate the behavior of some agents rather than an assumption of perfect rationality make this model well-suited for analyzing economic variables of interest from transition economies. Preliminary results from several runs of the model are included.

  15. Growing Old in Exile

    DEFF Research Database (Denmark)

    Liversage, Anika; Mirdal, Gretty Mizrahi

    2017-01-01

    Some studies on immigrants and ageing focus on the question of return; others focus on how immigrants, who grow old in their countries of destination, ‘age in place’, including whether they turn to their children or to public host country provisions for care and support. However, the issues...... of return and of ageing in place may both hold significance in individual immigrants’ lives. To investigate the changing expectations of old age throughout the life course, this paper draws on longitudinal interviews with immigrant women from Turkey who live in Denmark. We focus on the function of proximity...... to children. Using two women who were interviewed three times over three decades as case studies, the analysis shows that in the middle of life, the women share expectations of returning to Turkey, but these plans are perpetually postponed. As the women age, they must face their inability to leave...

  16. The growing fibroadenoma

    International Nuclear Information System (INIS)

    Sanders, Linda M; Sara, Rana

    2015-01-01

    Fibroadenomas (FAs) are the most common tumors of the breast clinically and pathologically in adolescent and young women but may be discovered at any age. With increasing use of core biopsy rather than excision for diagnosis, it is now commonplace to follow these lesions with imaging. To assess the incidence of epithelial abnormalities (atypia, in situ or invasive, ductal or lobular malignancies) in FAs diagnosed by core biopsy and to re-evaluate the management paradigm for any growing FA. A retrospective review of the senior author’s pathology results over 19 years identified 2062 nodular FAs (biopsied by ultrasound or stereotactic guidance). Eighty-three core biopsied FAs were identified which subsequently enlarged. Twelve of 2062 of core biopsied nodules demonstrated atypia, in situ, or invasive malignancy (ductal or lobular) within or adjacent to the FA (0.58%). Eighty-three FAs enlarged and underwent either surgical excision (n = 65), repeat core biopsy (n = 9), or imaging follow-up (n = 9). The incidence of atypia, in situ or invasive malignancy was 0/83 (0%). Two enlarging FAs were subsequently surgically diagnosed as benign phyllodes tumors (PT). Malignancy in or adjacent to a core biopsied FA is rare. The risk of cancer in a growing FA is even rarer; none were present in our series. FAs with abnormal epithelial abnormalities require excision. Otherwise, FAs without epithelial abnormality diagnosed by core biopsy need no specific follow-up considering the negligible incidence of conversion to malignancy. The breast interventionalist must know how to manage discordant pathology results

  17. Melting ice, growing trade?

    Directory of Open Access Journals (Sweden)

    Sami Bensassi

    2016-05-01

    Full Text Available Abstract Large reductions in Arctic sea ice, most notably in summer, coupled with growing interest in Arctic shipping and resource exploitation have renewed interest in the economic potential of the Northern Sea Route (NSR. Two key constraints on the future viability of the NSR pertain to bathymetry and the future evolution of the sea ice cover. Climate model projections of future sea ice conditions throughout the rest of the century suggest that even under the most “aggressive” emission scenario, increases in international trade between Europe and Asia will be very low. The large inter-annual variability of weather and sea ice conditions in the route, the Russian toll imposed for transiting the NSR, together with high insurance costs and scarce loading/unloading opportunities, limit the use of the NSR. We show that even if these obstacles are removed, the duration of the opening of the NSR over the course of the century is not long enough to offer a consequent boost to international trade at the macroeconomic level.

  18. Associação de diferentes fontes energéticas e protéicas em suplementos múltiplos na recria de novilhos mestiços sob pastejo no período da seca Association of different energy and protein sources in multiple supplements fed to growing crossbreed bulls at pasture in the dry season

    Directory of Open Access Journals (Sweden)

    Eduardo Henrique Bevitori Kling de Moraes

    2006-06-01

    seca, pois correspondem a aproximadamente 80% de sua composição. Observaram-se variações entre as frações dos carboidratos, assim como na taxa de degradação das fontes energéticas e protéicas estudadas.Two trials were conducted to investigate different protein and energy sources in multiple supplements fed to growing crossbred bulls. In the first experiment, performance of 20 crossbred growing bulls averaging 17 months of age and 265±18 kg of body weight was evaluated in the dry season. Animals were maintained in 1.5 ha paddocks of Brachiaria brizantha with supplements being offered daily in a proportion of 0.75% of the body weight. A completely randomized design with a 2 x 2 factorial arrangement was used. Supplements contained whole soybean (WSB or whole cottonseed (WCS as the protein sources and rice bran (RB or wheat bran (WB as the energy sources. No significant differences on the average daily weight gain (ADG, final body weight (FBW, and total weight gain were observed among diets in this trial. The ADG and FBW averaged 0.589 and 318.2, 0.530 and 317.2, 0.620 and 319.6 and 0.606 kg/day and 323.6 kg for animals fed supplements containing WSB/WB, WSB/RB, WCS/WB, and WCS/RB, respectively. The objective of the second study was to estimate the carbohydrate fractions of the pasture and that of the feeds used in multiple supplements as well as their digestion rates using the gas production technique. Forage had higher indigestible fraction (C and lower potentially degradable fraction (B2 compared to the supplements. Among supplements, WCS had the lowest C fraction while WSB and WB had the highest proportion of non-fiber carbohydrates (NFC. Although WCS had the highest content of C fraction, it also showed the fastest rate of digestion of the B2 fraction. Digestion rate of NFC were: 35.06, 14.86, 17.83 and 58.80, respectively for RB, WB, WSB and WCS. The choice of each protein and energy source will depend on market price and availability because there were

  19. Foreign launch competition growing

    Science.gov (United States)

    Brodsky, R. F.; Wolfe, M. G.; Pryke, I. W.

    1986-07-01

    A survey is given of progress made by other nations in providing or preparing to provide satellite launch services. The European Space Agency has four generations of Ariane vehicles, with a fifth recently approved; a second launch facility in French Guiana that has become operational has raised the possible Ariane launch rate to 10 per year, although a May failure of an Ariane 2 put launches on hold. The French Hermes spaceplane and the British HOTOL are discussed. Under the auspices of the Italian National Space Plane, the Iris orbital transfer vehicle is developed and China's Long March vehicles and the Soviet Protons and SL-4 vehicles are discussed; the Soviets moreover are apparently developing not only a Saturn V-class heavy lift vehicle with a 150,000-kg capacity (about five times the largest U.S. capacity) but also a space shuttle and a spaceplane. Four Japanese launch vehicles and some vehicles in an Indian program are also ready to provide launch services. In this new, tough market for launch services, the customers barely outnumber the suppliers. The competition develops just as the Challenger and Titan disasters place the U.S. at a disadvantage and underline the hard work ahead to recoup its heretofore leading position in launch services.

  20. BIOTECHNOLOGY IN FRUIT GROWING

    Directory of Open Access Journals (Sweden)

    Z. Jurković

    2008-09-01

    Full Text Available Research studies in the area of biotechnologies in fruit growing started at the Agricultural Institute Osijek in 2006 with the establishment of the first experimental in vitro laboratory for micropropagation. The laboratory started an active research related to the Project "Biotechnological methods in fruit tree identification, selection and propagation" Project is part of program "Preservation and revitalization of grape and fruit autochthonous cultivars". The goal of this research is to determine genetic differences between autochthonous and introduced cultivars of cherry as well as cultivars and types of sour cherry, to find and optimize a method for fast recovery of clonal material. A great number of cherry cultivars and types within the population of cv. Oblacinska sour cherry exists in Croatia. A survey with the purpose of selecting autochthonous cultivars for further selection has been done in previous research. Differences have been found in a number of important agronomic traits within the populations of cv. Oblačinska sour cherry. Autochthonous cherry cultivars are suspected to be synonyms of known old cultivars which were introduced randomly and have been naturalized under a local name. Identification and description of cultivars and types of fruits is based on special visible properties which were measurable or notable. In this approach difficulties arise from the effect of non-genetic factors on expression of certain traits. Genetic-physiological problem of S allele autoincompatibility exists within cherry cultivars. Therefore it is necessary to put different cultivars in the plantation to pollinate each other. Apart form the fast and certain sort identification independent of environmental factors, biotechnological methods based on PCR enable faster virus detection compared with classical serologic methods and indexing and cover a wider range of plant pathogens including those undetectable by other methods. Thermotherapy and

  1. Growing Galaxies Gently

    Science.gov (United States)

    2010-10-01

    New observations from ESO's Very Large Telescope have, for the first time, provided direct evidence that young galaxies can grow by sucking in the cool gas around them and using it as fuel for the formation of many new stars. In the first few billion years after the Big Bang the mass of a typical galaxy increased dramatically and understanding why this happened is one of the hottest problems in modern astrophysics. The results appear in the 14 October issue of the journal Nature. The first galaxies formed well before the Universe was one billion years old and were much smaller than the giant systems - including the Milky Way - that we see today. So somehow the average galaxy size has increased as the Universe has evolved. Galaxies often collide and then merge to form larger systems and this process is certainly an important growth mechanism. However, an additional, gentler way has been proposed. A European team of astronomers has used ESO's Very Large Telescope to test this very different idea - that young galaxies can also grow by sucking in cool streams of the hydrogen and helium gas that filled the early Universe and forming new stars from this primitive material. Just as a commercial company can expand either by merging with other companies, or by hiring more staff, young galaxies could perhaps also grow in two different ways - by merging with other galaxies or by accreting material. The team leader, Giovanni Cresci (Osservatorio Astrofisico di Arcetri) says: "The new results from the VLT are the first direct evidence that the accretion of pristine gas really happened and was enough to fuel vigorous star formation and the growth of massive galaxies in the young Universe." The discovery will have a major impact on our understanding of the evolution of the Universe from the Big Bang to the present day. Theories of galaxy formation and evolution may have to be re-written. The group began by selecting three very distant galaxies to see if they could find evidence

  2. Seasonality, mobility, and livability.

    Science.gov (United States)

    2012-01-31

    Signature project 4a, Seasonality, Mobility, and Livability investigated the effects of weather, season, built environment, community amenities, attitudes, and demographics on mobility and quality of life (QOL). A four season panel survey exami...

  3. 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.

  4. Variations and Trends in the Length of the Hydrologic Growing ...

    African Journals Online (AJOL)

    This paper examine the pattern of the Hydrologic Growing Season in a part of North western Nigeria in relation to crop Production and yield. It makes use of daily rainfall data obtained from Sokoto Agricultural Development project data were also obtained from the Nigeria Meteorological services Oshodi (SADP) in two ...

  5. Suplementação infrequente e fontes proteicas para recria de bovinos em pastejo no período seco: parâmetros nutricionais Infrequent supplementation and protein sources for growing steers grazing in the dry season: nutritional parameters

    Directory of Open Access Journals (Sweden)

    N.F. Paula

    2011-04-01

    Full Text Available Objetivou-se com este estudo avaliar os efeitos de fontes proteicas e da frequência de fornecimento de suplemento sobre o consumo e a digestibilidade dos nutrientes, as concentrações de nitrogênio amoniacal (N-NH3, o pH ruminal e o nitrogênio ureico no soro de bovinos recriados em pastagem de Brachiaria brizantha cv. Marandu no período seco. Foram utilizados cinco novilhos mestiços Nelore × Angus fistulados no rúmen, castrados, com peso médio inicial de 295 kg em um delineamento quadrado latino 5 × 5. Avaliaram-se dois suplementos isoproteicos, um com farelo de soja (FS e outro com farelo de algodão de alta energia, fornecidos em duas frequências: diariamente (7 vezes por semana e 3 vezes por semana (segundas, quartas e sextas-feiras; e mistura mineral (MM. A suplementação aumentou o consumo de PB, extrato etéreo (EE e carboidratos não-fibrosos (CNF, em kg/dia. O suplemento com farelo de algodão o consumo de extrato etéreo. Houve efeito positivo da suplementação 3 vezes por semana sobre os consumos de matéria seca total, de forragem, de matéria orgânica de forragem, carboidratos totais (CT e FDN. A suplementação reduziu a digestibilidade da FDN e aumentou a de PB. O suplemento com farelo de algodão reduziu a digestibilidade de FDN e carboidratos totais. A suplementação 3 vezes por semana não afetou a digestibilidade dos nutrientes nem o pH ruminal. O consumo de suplemento aumenta as concentrações de N-NH3, principalmente se realizado 3 vezes por semana. As concentrações de nitrogênio ureico no soro de bovinos em pastejo aumentam com o consumo de suplementos.The objective of this study was to evaluate the effects of protein sources and frequency of supplement offer on the intake and nutrient digestibility, on the concentrations of ammonia nitrogen (N-NH3, on rumen pH and on serum urea nitrogen concentrations in steers grazing pasture of Brachiaria brizantha cv. Marandu during the dry season. Five crossbred Zebu

  6. Dissecting the Variations of Ripening Progression and Flavonoid Metabolism in Grape Berries Grown under Double Cropping System

    Directory of Open Access Journals (Sweden)

    Wei-Kai Chen

    2017-11-01

    Full Text Available A double cropping system has been commercially adopted in southern China, where there is abundant sunshine and heat resources. In this viticulture system, the first growing season normally starts as a summer cropping cycle; then, the vine is pruned and forced, resulting in a second crop in winter. Due to climate differences between the summer and winter growing seasons, grape ripening progression and flavonoid metabolism vary greatly. Here, the metabolites and transcriptome of flavonoid pathways were analyzed in grapes grown under two growing seasons at different stages. Notably, the winter cropping cycle strongly increased flavonoid levels by several times in comparison to summer grapes, while the summer season took a major toll on anthocyanin and flavonol accumulation, since the winter cropping greatly triggered the expression of upstream genes in the flavonoid pathway in a coordinated expression pattern. Moreover, the ratio of VviF3′5′Hs (flavonoid 3′5′-hydroxylase to VviF3′Hs (flavonoid 3′-hydroxylase transcript levels correlated remarkably well with the ratio of 3′5′-substituted to 3′-substituted flavonoids, which was presumed to control the flux of intermediates into different flavonoid branches. On the other hand, the phenological phase also varied greatly in the two crops. Compared to summer cropping, winter growing season accelerated the duration from budburst to veraison, therefore advancing the onset of ripening, but also prolonging the duration of ripening progression due to the purposes to harvest high-quality grapes. The differential expression pattern of hormone-related genes between the two cropping cycles might explain this phenomenon.

  7. Enhancing Out-of-Season Production of Tomatoes and Lettuce Using High Tunnels

    OpenAIRE

    Hunter, Britney L.

    2010-01-01

    The growing season for vegetable crops is limited by freezing temperatures in arid high elevation climates such as northern Utah. Logan, Utah (41.73 N, 111.83 W, 1382 m elevation) has a short, variable growing season with an average frost-free period of 135 days. Extending the growing season provides growers with an opportunity to extend revenue into a normally unproductive period and benefit from out-of-season price premiums. High tunnels have been used to effectively extend the growing s...

  8. Late-season nitrogen applications in high-latitude strawberry ...

    African Journals Online (AJOL)

    The influence of late-season nitrogen (N) applications on the fruiting pattern of strawberry runner plants of 'Camarosa' was determined over three growing seasons. Experiments were carried out in highlatitude nurseries in northern California and fruit production trials were established in southern California. A total of 80 ...

  9. Seasonal response of Eragrostis curvula to nitrogen | R | African ...

    African Journals Online (AJOL)

    On the basis of the seasonal response of Eragrostis curvula to nitrogen applied as single dressings to separate plots at the beginning of each of the six months of the growing season, it is deduced that nitrogen can profitably be applied in the Ukulinga environment from early spring though to early January. Late summer and ...

  10. Algorithms for in-season nutrient management in cereals

    Science.gov (United States)

    The demand for improved decision making products for cereal production systems has placed added emphasis on using plant sensors in-season, and that incorporate real-time, site specific, growing environments. The objective of this work was to describe validated in-season sensor based algorithms prese...

  11. Seasonal differences in leaf-level physiology give lianas a competitive advantage over trees in a tropical seasonal forest

    NARCIS (Netherlands)

    Cai, Z.Q.; Schnitzer, S.A.; Bongers, F.

    2009-01-01

    Lianas are an important component of most tropical forests, where they vary in abundance from high in seasonal forests to low in aseasonal forests. We tested the hypothesis that the physiological ability of lianas to fix carbon (and thus grow) during seasonal drought may confer a distinct advantage

  12. Seasonal thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  13. Seasonal Influenza Questions & Answers

    Science.gov (United States)

    ... in Long-Term Care Facilities Guidance: Use of Mask to Control Influenza Transmission Guidance: Prevention & Control in ... overall health impact (e.g., infections, hospitalizations, and deaths) of a flu season varies from season to ...

  14. Sorting Out Seasonal Allergies

    Science.gov (United States)

    ... Close ‹ Back to Healthy Living Sorting Out Seasonal Allergies Sneezing, runny nose, nasal congestion. Symptoms of the ... How do I know if I have seasonal allergies? According to Dr. Georgeson, the best way to ...

  15. How Your Fetus Grows During Pregnancy

    Science.gov (United States)

    ... ACOG Pregnancy Book How Your Fetus Grows During Pregnancy Patient Education FAQs How Your Fetus Grows During Pregnancy Patient Education Pamphlets - Spanish How Your Fetus Grows During Pregnancy ...

  16. Seasonal Allergies (Hay Fever)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Seasonal Allergies (Hay Fever) KidsHealth / For Parents / Seasonal Allergies (Hay ... español Alergia estacional (fiebre del heno) About Seasonal Allergies "Achoo!" It's your son's third sneezing fit of ...

  17. Seasonal Variation in Epidemiology

    Science.gov (United States)

    Marrero, Osvaldo

    2013-01-01

    Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

  18. Seasonal and clonal variation in cellulose microfibril orientation during cell wall formation of tracheids in Cryptomeria japonica.

    Science.gov (United States)

    Jyske, Tuula; Fujiwara, Takeshi; Kuroda, Katsushi; Iki, Taiichi; Zhang, Chunhua; Jyske, Tuomas K; Abe, Hisashi

    2014-08-01

    To investigate the biological mechanism by which trees control the changes in microfibril (MF) orientation among secondary cell wall layers of conifer tracheids, we studied seasonal variation in the orientation of newly deposited MFs during tracheid cell wall development in Japanese cedar (Cryptomeria japonica D. Don) trees growing in Central Japan (36°36'N, 140°39'E). Sample blocks were repeatedly collected from four 16-year-old clones of different origins during the growing season of 2010 to investigate the hypotheses that changes in cellulose MF orientation between wall layers exhibited seasonal and clonal differences. The progressive change in the orientation of newly deposited MFs on the primary and secondary cell wall layers of tracheids was detected by field-emission-scanning electron microscopy. Tracheid production and differentiation was studied by light microscopy. We observed a decreasing trend in the orientation of deposited MFs from earlywood to latewood in the S2 and S1 layers, where MFs appeared in a Z-helix. In contrast, no seasonal pattern in the orientation of the MFs in the S-helix was observed. Minor clonal variation was observed in the phenology of tracheid production and differentiation. We concluded that a seasonal decreasing trend in the orientation of the MFs in the Z-helix in S1 and S2 was present, whereas the MFs in other layers exhibited minor random variations. Thus, the orientation of the MFs in S2 was affected by seasonal factors, whereas the MFs in other layers were more intrinsically controlled. The within-ring variations in the MF orientation and thus the resulting average MF angle might also be related to genotypic differences in the tracheid production and differentiation rate. However, our results do not exclude other intrinsic and environmental regulations in the change in MF orientation, which remains a topic for future studies. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions

  19. The Variability of Seasonality.

    Science.gov (United States)

    Pezzulli, S.; Stephenson, D. B.; Hannachi, A.

    2005-01-01

    Seasons are the complex nonlinear response of the physical climate system to regular annual solar forcing. There is no a priori reason why they should remain fixed/invariant from year to year, as is often assumed in climate studies when extracting the seasonal component. The widely used econometric variant of Census Method II Seasonal Adjustment Program (X-11), which allows for year-to-year variations in seasonal shape, is shown here to have some advantages for diagnosing climate variability. The X-11 procedure is applied to the monthly mean Niño-3.4 sea surface temperature (SST) index and global gridded NCEP-NCAR reanalyses of 2-m surface air temperature. The resulting seasonal component shows statistically significant interannual variations over many parts of the globe. By taking these variations in seasonality into account, it is shown that one can define less ambiguous ENSO indices. Furthermore, using the X-11 seasonal adjustment approach, it is shown that the three cold ENSO episodes after 1998 are due to an increase in amplitude of seasonality rather than being three distinct La Niña events. Globally, variations in the seasonal component represent a substantial fraction of the year-to-year variability in monthly mean temperatures. In addition, strong teleconnections can be discerned between the magnitude of seasonal variations across the globe. It might be possible to exploit such relationships to improve the skill of seasonal climate forecasts.

  20. Why does inequality grow? Can we do something about it?

    NARCIS (Netherlands)

    Teulings, C.

    2014-01-01

    Income inequality has increased worldwide in recent years. This column discusses the role of technological progress, globalisation, and the liberalisation of labour-market institutions in this growing inequality. The liberalisation of labour market institutions has made labour markets more flexible

  1. Addressing the growing international challenge of cancer: a multinational perspective.

    Science.gov (United States)

    Varmus, Harold; Kumar, Harpal S

    2013-03-06

    Leaders in cancer research and policy from 15 economically diverse countries met at the U.S. National Institutes of Health in November 2012 to discuss opportunities to reduce cancer incidence and mortality, improve cancer care, and increase our understanding of disease pathophysiology. Here, we present recommendations that the participants believe will enable faster progress in addressing the growing international challenge of cancer.

  2. Cool Season Paleotemperatures at Tree Line in Taiwan

    Science.gov (United States)

    Wright, W. E.; Chan, M.

    2011-12-01

    Taiwan has over 200 mountains whose peaks exceed 3,000 meters in elevation. Despite straddling the Tropic of Cancer, the higher peaks have snow and freezing temperatures every winter. Trees growing above 3,500 meters show clear temperature variation, even producing frost rings. Yet unlike temperate tree-line species, with their warm season temperature signal, trees growing at Taiwan's tree line show sensitivity to cool season temperatures. Juniperus squamata growing above 3,500 meters in central Taiwan have ring width time series that commonly exceed 600 years. Presented are the first dendroclimatological analyses from Taiwanese Juniperus squamata.

  3. Growing Oppression, Growing Resistance : LGBT Activism and Europeanisation in Macedonia

    NARCIS (Netherlands)

    Miškovska Kajevska, A.; Bilić, B.

    2016-01-01

    This chapter provides one of the first socio-historical overviews of the LGBT groups in Macedonia and argues that an important impetus for the proliferation of LGBT activities has been the growing state-endorsed homophobia starting from 2008. The homophobic rhetoric of the ruling parties was clearly

  4. Cheap heat grows in fields

    International Nuclear Information System (INIS)

    Haluza, I.

    2006-01-01

    Slovak farmers resemble the peasants from the film T he Magnificent Seven . They keep complaining about their fate but consider any innovation as an interference. And that is why they still have not started growing fast-growing wood although the number of heating plants processing bio-mass from forests and fields is growing. Natural gas is expensive and coal creates pollution. Energy from biomass is becoming a good business and also creates new business opportunities - growing the raw material it needs. Such heating plants usually use waste from wood processing companies and Slovak Forests (Lesy SR) has also started deliveries of chip wood from old forests. There are plantations of fast growing wood suitable for heat production of over 500-thousand hectares throughout the EU. This is about 10% of Slovakian's area where the first plantations are also already being set up. The first promising plantation project was launched this spring. And this is not a project launched and backed by a big company but a starting up businessman, Miroslav Forgac from Kosice. He founded his company, Forgim, last winter. Without big money involved and thank to a new business idea he managed to persuade farmers to set up the first plantations. He supplied the seedlings and the business has started with 75 ha of plantations around Trnava, Sala, Komarno, Lucenec, Poprad and Kosice. He is gradually signing contracts with other landowners and next year the area of plantations is set to grow by 1500 ha. Plantations of fast growing trees such as willow, poplar and acacia regenerate by new trees growing out of the roots of the old and from cut trees so from one seedling and one investment there can be several harvests. Swedish willows from Forgim regenerate 20 to 25 years after the first planting. And only then new seedlings have to be purchased. Using special machines that even cut the wood to wood chips the plantations can be 'harvested' every three years. Unlike crops, the fields do not

  5. Crucible Grows Wide Silicon Ribbon

    Science.gov (United States)

    Seidensticker, R.

    1982-01-01

    Inexpensive manufacture of solar cells may require quality silicon ribbon crystals. One way to produce them is by growing wide dendritic webs, which can be very long and have high structural perfection. Dendrites grow from supercooled melt, so width of ribbon depends on how wide a region of supercooled molten silicon can be maintained in crucible. Elongated geometry of suscepter/crucible/lid assembly allows molten silicon to supercool over a wider region -- a necessary condition for the growth of wide dendritic crystal ribbon.

  6. Historical warnings of future food insecurity with unprecedented seasonal heat.

    Science.gov (United States)

    Battisti, David S; Naylor, Rosamond L

    2009-01-09

    Higher growing season temperatures can have dramatic impacts on agricultural productivity, farm incomes, and food security. We used observational data and output from 23 global climate models to show a high probability (>90%) that growing season temperatures in the tropics and subtropics by the end of the 21st century will exceed the most extreme seasonal temperatures recorded from 1900 to 2006. In temperate regions, the hottest seasons on record will represent the future norm in many locations. We used historical examples to illustrate the magnitude of damage to food systems caused by extreme seasonal heat and show that these short-run events could become long-term trends without sufficient investments in adaptation.

  7. Seasonality of tuberculosis

    Directory of Open Access Journals (Sweden)

    Auda Fares

    2011-01-01

    Full Text Available Objectives: This study was designed to review previous studies and analyse the current knowledge and controversies related to seasonal variability of tuberculosis (TB to examine whether TB has an annual seasonal pattern. Study Design and Methods: Systematic review of peer reviewed studies identified through literature searches using online databases belonging to PubMed and the Cochrane library with key words "Tuberculosis, Seasonal influence" and " Tuberculosis, Seasonal variation". The search was restricted to articles published in English. The references of the identified papers for further relevant publications were also reviewed. Results: Twelve studies conducted between the period 1971 and 2006 from 11 countries/regions around the world (South Western Cameroon, South Africa, India, Hong Kong, Japan, Kuwait, Spain, UK, Ireland, Russia, and Mongolia were reviewed. A seasonal pattern of tuberculosis with a mostly predominant peak is seen during the spring and summer seasons in all of the countries (except South Western Cameroon and Russia. Conclusions: The observation of seasonality leads to assume that the risk of transmission of M. tuberculosis does appear to be the greatest during winter months. Vitamin D level variability, indoor activities, seasonal change in immune function, and delays in the diagnosis and treatment of tuberculosis are potential stimuli of seasonal tuberculosis disease. Additionally, seasonal variation in food availability and food intake, age, and sex are important factors which can play a role in the tuberculosis notification variability. Prospective studies regarding this topic and other related subjects are highly recommended.

  8. Benchmarking Successional Progress in a Quantitative Food Web

    Science.gov (United States)

    Boit, Alice; Gaedke, Ursula

    2014-01-01

    Central to ecology and ecosystem management, succession theory aims to mechanistically explain and predict the assembly and development of ecological communities. Yet processes at lower hierarchical levels, e.g. at the species and functional group level, are rarely mechanistically linked to the under-investigated system-level processes which drive changes in ecosystem properties and functioning and are comparable across ecosystems. As a model system for secondary succession, seasonal plankton succession during the growing season is readily observable and largely driven autogenically. We used a long-term dataset from large, deep Lake Constance comprising biomasses, auto- and heterotrophic production, food quality, functional diversity, and mass-balanced food webs of the energy and nutrient flows between functional guilds of plankton and partly fish. Extracting population- and system-level indices from this dataset, we tested current hypotheses about the directionality of successional progress which are rooted in ecosystem theory, the metabolic theory of ecology, quantitative food web theory, thermodynamics, and information theory. Our results indicate that successional progress in Lake Constance is quantifiable, passing through predictable stages. Mean body mass, functional diversity, predator-prey weight ratios, trophic positions, system residence times of carbon and nutrients, and the complexity of the energy flow patterns increased during succession. In contrast, both the mass-specific metabolic activity and the system export decreased, while the succession rate exhibited a bimodal pattern. The weighted connectance introduced here represents a suitable index for assessing the evenness and interconnectedness of energy flows during succession. Diverging from earlier predictions, ascendency and eco-exergy did not increase during succession. Linking aspects of functional diversity to metabolic theory and food web complexity, we reconcile previously disjoint bodies of

  9. Benchmarking successional progress in a quantitative food web.

    Science.gov (United States)

    Boit, Alice; Gaedke, Ursula

    2014-01-01

    Central to ecology and ecosystem management, succession theory aims to mechanistically explain and predict the assembly and development of ecological communities. Yet processes at lower hierarchical levels, e.g. at the species and functional group level, are rarely mechanistically linked to the under-investigated system-level processes which drive changes in ecosystem properties and functioning and are comparable across ecosystems. As a model system for secondary succession, seasonal plankton succession during the growing season is readily observable and largely driven autogenically. We used a long-term dataset from large, deep Lake Constance comprising biomasses, auto- and heterotrophic production, food quality, functional diversity, and mass-balanced food webs of the energy and nutrient flows between functional guilds of plankton and partly fish. Extracting population- and system-level indices from this dataset, we tested current hypotheses about the directionality of successional progress which are rooted in ecosystem theory, the metabolic theory of ecology, quantitative food web theory, thermodynamics, and information theory. Our results indicate that successional progress in Lake Constance is quantifiable, passing through predictable stages. Mean body mass, functional diversity, predator-prey weight ratios, trophic positions, system residence times of carbon and nutrients, and the complexity of the energy flow patterns increased during succession. In contrast, both the mass-specific metabolic activity and the system export decreased, while the succession rate exhibited a bimodal pattern. The weighted connectance introduced here represents a suitable index for assessing the evenness and interconnectedness of energy flows during succession. Diverging from earlier predictions, ascendency and eco-exergy did not increase during succession. Linking aspects of functional diversity to metabolic theory and food web complexity, we reconcile previously disjoint bodies of

  10. Benchmarking successional progress in a quantitative food web.

    Directory of Open Access Journals (Sweden)

    Alice Boit

    Full Text Available Central to ecology and ecosystem management, succession theory aims to mechanistically explain and predict the assembly and development of ecological communities. Yet processes at lower hierarchical levels, e.g. at the species and functional group level, are rarely mechanistically linked to the under-investigated system-level processes which drive changes in ecosystem properties and functioning and are comparable across ecosystems. As a model system for secondary succession, seasonal plankton succession during the growing season is readily observable and largely driven autogenically. We used a long-term dataset from large, deep Lake Constance comprising biomasses, auto- and heterotrophic production, food quality, functional diversity, and mass-balanced food webs of the energy and nutrient flows between functional guilds of plankton and partly fish. Extracting population- and system-level indices from this dataset, we tested current hypotheses about the directionality of successional progress which are rooted in ecosystem theory, the metabolic theory of ecology, quantitative food web theory, thermodynamics, and information theory. Our results indicate that successional progress in Lake Constance is quantifiable, passing through predictable stages. Mean body mass, functional diversity, predator-prey weight ratios, trophic positions, system residence times of carbon and nutrients, and the complexity of the energy flow patterns increased during succession. In contrast, both the mass-specific metabolic activity and the system export decreased, while the succession rate exhibited a bimodal pattern. The weighted connectance introduced here represents a suitable index for assessing the evenness and interconnectedness of energy flows during succession. Diverging from earlier predictions, ascendency and eco-exergy did not increase during succession. Linking aspects of functional diversity to metabolic theory and food web complexity, we reconcile

  11. Progress Report

    DEFF Research Database (Denmark)

    Duer, Karsten

    1999-01-01

    Progress report describing the work carried out by the Danish participant in the ALTSET project in the period January 1999 to July 1999.......Progress report describing the work carried out by the Danish participant in the ALTSET project in the period January 1999 to July 1999....

  12. Seasonal trends of biogenic terpene emissions.

    Science.gov (United States)

    Helmig, Detlev; Daly, Ryan Woodfin; Milford, Jana; Guenther, Alex

    2013-09-01

    Biogenic volatile organic compound (BVOC) emissions from six coniferous tree species, i.e. Pinus ponderosa (Ponderosa Pine), Picea pungens (Blue Spruce), Pseudotsuga menziesii (Rocky Mountain Douglas Fir) and Pinus longaeva (Bristlecone Pine), as well as from two deciduous species, Quercus gambelii (Gamble Oak) and Betula occidentalis (Western River Birch) were studied over a full annual growing cycle. Monoterpene (MT) and sesquiterpene (SQT) emissions rates were quantified in a total of 1236 individual branch enclosure samples. MT dominated coniferous emissions, producing greater than 95% of BVOC emissions. MT and SQT demonstrated short-term emission dependence with temperature. Two oxygenated MT, 1,8-cineol and piperitone, were both light and temperature dependent. Basal emission rates (BER, normalized to 1000μmolm(-2)s(-1) and 30°C) were generally higher in spring and summer than in winter; MT seasonal BER from the coniferous trees maximized between 1.5 and 6.0μgg(-1)h(-1), while seasonal lows were near 0.1μgg(-1)h(-1). The fractional contribution of individual MT to total emissions was found to fluctuate with season. SQT BER measured from the coniferous trees ranged from emissions modeling, was not found to exhibit discernible growth season trends. A seasonal correction factor proposed by others in previous work to account for a sinusoidal shaped emission pattern was applied to the data. Varying levels of agreement were found between the data and model results for the different plant species seasonal data sets using this correction. Consequently, the analyses on this extensive data set suggest that it is not feasible to apply a universal seasonal correction factor across different vegetation species. A modeling exercise comparing two case scenarios, (1) without and (2) with consideration of the seasonal changes in emission factors illustrated large deviations when emission factors are applied for other seasons than those in which they were experimentally

  13. Cotton irrigation timing with variable seasonal irrigation capacities in the Texas south plains.

    Science.gov (United States)

    Within the Ogallala Aquifer Region of Texas, the irrigation capacity (IC) for a given field often changes within a growing season due to seasonal depletion of the aquifer, in season changes in crop irrigation needs in dry years, or consequences of irrigation volume limits imposed by irrigation distr...

  14. Responses of inulin content and inulin yield of Jerusalem artichoke genotypes to seasonal environments

    Science.gov (United States)

    Seasonal variation (e.g. temperature and photoperiod) between growing seasons might affect inulin content and inulin yield of Jerusalem artichoke. However, there is limited information on genotypic response to seasons for inulin content and inulin yield. The objective of this study was to investig...

  15. Inferences from growing trees backwards

    Science.gov (United States)

    David W. Green; Kent A. McDonald

    1997-01-01

    The objective of this paper is to illustrate how longitudinal stress wave techniques can be useful in tracking the future quality of a growing tree. Monitoring the quality of selected trees in a plantation forest could provide early input to decisions on the effectiveness of management practices, or future utilization options, for trees in a plantation. There will...

  16. Growing an Emerging Research University

    Science.gov (United States)

    Birx, Donald L.; Anderson-Fletcher, Elizabeth; Whitney, Elizabeth

    2013-01-01

    The emerging research college or university is one of the most formidable resources a region has to reinvent and grow its economy. This paper is the first of two that outlines a process of building research universities that enhance regional technology development and facilitate flexible networks of collaboration and resource sharing. Although the…

  17. Thallium toxicity: A growing concern

    OpenAIRE

    Saha A

    2005-01-01

    This review article deals with the growing concern of the toxicity of thallium. This article describes the characteristics of thallium, its potential sources of exposure, kinetics, and toxicity on human being and diagnosis of thallium poisoning. This article also describes some episodes of thallium poisoning arising from both occupational and nonoccupational exposure.

  18. Organization of growing random networks

    Energy Technology Data Exchange (ETDEWEB)

    Krapivsky, P. L.; Redner, S.

    2001-06-01

    The organizational development of growing random networks is investigated. These growing networks are built by adding nodes successively, and linking each to an earlier node of degree k with an attachment probability A{sub k}. When A{sub k} grows more slowly than linearly with k, the number of nodes with k links, N{sub k}(t), decays faster than a power law in k, while for A{sub k} growing faster than linearly in k, a single node emerges which connects to nearly all other nodes. When A{sub k} is asymptotically linear, N{sub k}(t){similar_to}tk{sup {minus}{nu}}, with {nu} dependent on details of the attachment probability, but in the range 2{lt}{nu}{lt}{infinity}. The combined age and degree distribution of nodes shows that old nodes typically have a large degree. There is also a significant correlation in the degrees of neighboring nodes, so that nodes of similar degree are more likely to be connected. The size distributions of the in and out components of the network with respect to a given node{emdash}namely, its {open_quotes}descendants{close_quotes} and {open_quotes}ancestors{close_quotes}{emdash}are also determined. The in component exhibits a robust s{sup {minus}2} power-law tail, where s is the component size. The out component has a typical size of order lnt, and it provides basic insights into the genealogy of the network.

  19. Heat stress in growing pigs

    NARCIS (Netherlands)

    Huynh Thi Thanh Thuy,

    2005-01-01

    Compared to other species of farm animals, pigs are more sensitive to high environmental temperatures, because they cannot sweat and do not pant so well. Furthermore, fast-growing lean pigs generate more heat than their congeners living in the wild. This, in combination with confined housing, makes

  20. Growing Crystals on the Ceiling.

    Science.gov (United States)

    Christman, Robert A.

    1980-01-01

    Described is a method of studying growing crystals in a classroom utilizing a carrousel projector standing vertically. A saturated salt solution is placed on a slide on the lens of the projector and the heat from the projector causes the water to evaporate and salt to crystalize. (Author/DS)

  1. Exploring Classroom Hydroponics. Growing Ideas.

    Science.gov (United States)

    National Gardening Association, Burlington, VT.

    Growing Ideas, the National Gardening Association's series for elementary, middle, and junior high school educators, helps teachers engage students in using plants and gardens as contexts for developing a deeper, richer understanding of the world around them. This volume's focus is on hydroponics. It presents basic hydroponics information along…

  2. Influenza Seasonal Summary, 2014-2015 Season

    Science.gov (United States)

    2015-08-14

    Frequency of Influenza Antivira l Prescript ions Dispensed to DON Beneficiaries in Comparison with Seasonal Basel ine 2014-2015 Season 900 Cl) g 800...so 51 52 53 1 2 3 4 5 6 7 8 9 10 11 12 Week - 2014-2015 - Basel ine Basel ine ca lculated as the weighted average of the number of influenza speci...2015 Season 1.2x ~ 3.0x • 0.8x 2.4 .... ~ _...sx 2.0x N W+E o 100 200 •oo 600 eoo ioo:::::iiio::::i--’==::::: iii -oiiMdes • 2.5x • 4.7x 0

  3. Temperature Response of Soil Respiration in a Chinese Pine Plantation: Hysteresis and Seasonal vs. Diel Q10

    Science.gov (United States)

    Jia, Xin; Zha, Tianshan; Wu, Bin; Zhang, Yuqing; Chen, Wenjing; Wang, Xiaoping; Yu, Haiqun; He, Guimei

    2013-01-01

    Although the temperature response of soil respiration (Rs) has been studied extensively, several issues remain unresolved, including hysteresis in the Rs–temperature relationship and differences in the long- vs. short-term Rs sensitivity to temperature. Progress on these issues will contribute to reduced uncertainties in carbon cycle modeling. We monitored soil CO2 efflux with an automated chamber system in a Pinus tabulaeformis plantation near Beijing throughout 2011. Soil temperature at 10-cm depth (Ts) exerted a strong control over Rs, with the annual temperature sensitivity (Q10) and basal rate at 10°C (Rs10) being 2.76 and 1.40 µmol m−2 s−1, respectively. Both Rs and short-term (i.e., daily) estimates of Rs10 showed pronounced seasonal hysteresis with respect to Ts, with the efflux in the second half of the year being larger than that early in the season for a given temperature. The hysteresis may be associated with the confounding effects of microbial population dynamics and/or litter input. As a result, all of the applied regression models failed to yield unbiased estimates of Rs over the entire annual cycle. Lags between Rs and Ts were observed at the diel scale in the early and late growing season, but not in summer. The seasonality in these lags may be due to the use of a single Ts measurement depth, which failed to represent seasonal changes in the depth of CO2 production. Daily estimates of Q10 averaged 2.04, smaller than the value obtained from the seasonal relationship. In addition, daily Q10 decreased with increasing Ts, which may contribute feedback to the climate system under global warming scenarios. The use of a fixed, universal Q10 is considered adequate when modeling annual carbon budgets across large spatial extents. In contrast, a seasonally-varying, environmentally-controlled Q10 should be used when short-term accuracy is required. PMID:23469089

  4. Progressive Business

    DEFF Research Database (Denmark)

    Christiansen, Christian O.

    2016-01-01

    Guest Post to the Society for U.S. Intellectual History Blog. Brief introduction to the book Progressive Business: An Intellectual History of the Role of Business in American Society, Oxford U.P., 2015.......Guest Post to the Society for U.S. Intellectual History Blog. Brief introduction to the book Progressive Business: An Intellectual History of the Role of Business in American Society, Oxford U.P., 2015....

  5. Heat stress in growing pigs

    OpenAIRE

    Huynh Thi Thanh Thuy

    2005-01-01

    Compared to other species of farm animals, pigs are more sensitive to high environmental temperatures, because they cannot sweat and do not pant so well. Furthermore, fast-growing lean pigs generate more heat than their congeners living in the wild. This, in combination with confined housing, makes it difficult for these pigs to regulate their heat balance. Heat stressed pigs have low performance, poor welfare, and, by pen fouling, they give higher emissions of odour and ammonia.Above certain...

  6. Carbonaceous Matter in Growing Nanoparticles

    Science.gov (United States)

    Johnston, M. V.; Stangl, C. M.; Horan, A. J.

    2015-12-01

    Atmospheric nanoparticles constitute the greatest portion of ambient aerosol loading by number. A major source of atmospheric nanoparticles is new particle formation (NPF), a gas to particle conversion process whereby clusters nucleate from gas phase precursors to form clusters on the order of one or a few nanometers and then grow rapidly to climatically relevant sizes. A substantial fraction of cloud condensation nuclei (CCN) are thought to arise from NPF. In order to better predict the frequency, growth rates, and climatic impacts of NPF, knowledge of the chemical mechanisms by which nucleated nanoparticles grow is needed. The two main contributors to particle growth are (neutralized) sulfate and carbonaceous matter. Particle growth by sulfuric acid condensation is generally well understood, though uncertainty remains about the extent of base neutralization and the relative roles of ammonia and amines. Much less is known about carbonaceous matter, and field measurements suggest that nitrogen-containing species are important. In this presentation, recent work by our group will be described that uses a combination of ambient measurements, laboratory experiments and computational work to study carbonaceous matter in growing nanoparticles. These studies span a range of particle sizes from the initial adsorption of molecules onto a nanometer-size ammonium bisulfate seed cluster to reactions in particles that are large enough to support condensed-phase chemistry.

  7. Establishing native warm season grasses on Eastern Kentucky strip mines

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, T.G.; Larkin, J.L.; Arnett, M.B. [Univ. of Kentucky, Lexington, KY (United States). Dept. of Forestry

    1998-12-31

    The authors evaluated various methods of establishing native warm season grasses on two reclaimed Eastern Kentucky mines from 1994--1997. Most current reclamation practices incorporate the use of tall fescue (Festuca arundinacea) and other cool-season grasses/legumes that provide little wildlife habitats. The use of native warm season grasses will likely improve wildlife habitat on reclaimed strip mines. Objectives of this study were to compare the feasibility of establishing these grasses during fall, winter, or spring using a native rangeland seeder or hydroseeding; a fertilizer application at planting; or cold-moist stratification prior to hydroseeding. Vegetative cover, bare ground, species richness, and biomass samples were collected at the end of each growing season. Native warm season grass plantings had higher plant species richness compared to cool-season reclamation mixtures. There was no difference in establishment of native warm season grasses as a result of fertilization or seeding technique. Winter native warm season grass plantings were failures and cold-moist stratification did not increase plant establishment during any season. As a result of a drought during 1997, both cool-season and warm season plantings were failures. Cool-season reclamation mixtures had significantly more vegetative cover and biomass compared to native warm season grass mixtures and the native warm season grass plantings did not meet vegetative cover requirements for bond release. Forbs and legumes that established well included pale purple coneflower (Echinacea pallida), lance-leaf coreopsis (Coreopsis lanceolata), round-headed lespedeza (Lespedeza capitata), partridge pea (Cassia fasiculata), black-eyed susan (Rudbeckia hirta), butterfly milkweed (Asclepias tuberosa), and bergamot (Monarda fistulosa). Results from two demonstration plots next to research plots indicate it is possible to establish native warm season grasses on Eastern Kentucky strip mines for wildlife habitat.

  8. Establishing native warm season grasses on Eastern Kentucky strip mines

    International Nuclear Information System (INIS)

    Barnes, T.G.; Larkin, J.L.; Arnett, M.B.

    1998-01-01

    The authors evaluated various methods of establishing native warm season grasses on two reclaimed Eastern Kentucky mines from 1994--1997. Most current reclamation practices incorporate the use of tall fescue (Festuca arundinacea) and other cool-season grasses/legumes that provide little wildlife habitats. The use of native warm season grasses will likely improve wildlife habitat on reclaimed strip mines. Objectives of this study were to compare the feasibility of establishing these grasses during fall, winter, or spring using a native rangeland seeder or hydroseeding; a fertilizer application at planting; or cold-moist stratification prior to hydroseeding. Vegetative cover, bare ground, species richness, and biomass samples were collected at the end of each growing season. Native warm season grass plantings had higher plant species richness compared to cool-season reclamation mixtures. There was no difference in establishment of native warm season grasses as a result of fertilization or seeding technique. Winter native warm season grass plantings were failures and cold-moist stratification did not increase plant establishment during any season. As a result of a drought during 1997, both cool-season and warm season plantings were failures. Cool-season reclamation mixtures had significantly more vegetative cover and biomass compared to native warm season grass mixtures and the native warm season grass plantings did not meet vegetative cover requirements for bond release. Forbs and legumes that established well included pale purple coneflower (Echinacea pallida), lance-leaf coreopsis (Coreopsis lanceolata), round-headed lespedeza (Lespedeza capitata), partridge pea (Cassia fasiculata), black-eyed susan (Rudbeckia hirta), butterfly milkweed (Asclepias tuberosa), and bergamot (Monarda fistulosa). Results from two demonstration plots next to research plots indicate it is possible to establish native warm season grasses on Eastern Kentucky strip mines for wildlife habitat

  9. Seasonal phenology and natural enemies of the squash bug (Hemiptera: Coreidae) in Kentucky.

    Science.gov (United States)

    Decker, Kimberly B; Yeargan, Kenneth V

    2008-06-01

    The squash bug, Anasa tristis (De Geer), is a major indigenous pest of Cucurbita species across the United States and a vector of cucurbit yellow vine disease. The seasonal phenology of the squash bug in central Kentucky and its natural enemies were studied using summer squash planted sequentially throughout the 2005 and 2006 growing seasons. The squash bug was first detected on 5 June 2005 and 3 June 2006. In both years, peak numbers of all squash bug stages occurred in July and August. Our field data, substantiated by published degree-day models for squash bug development, suggest one complete and a partial second generation of squash bugs in 2005 and one complete generation of squash bugs in 2006. The most abundant ground-active predators in squash fields included Araneae, Carabidae, Staphylinidae, and Geocoridae. Coleomegilla maculata (De Geer) and Geocoris punctipes (Say) were the most abundant foliage-inhabiting predators. Direct field observations of predators feeding on squash bugs or their eggs included G. punctipes, Pagasa fusca (Stein), and Nabis sp. The parasitoids Trichopoda pennipes (Fabricius) and Gyron pennsylvanicum (Ashmead) were found also. Squash bug egg masses were monitored to determine predation and parasitism rates in the field. In four studies during 2005 and 2006, predation rates were low (7% or less), and parasitism ranged from 0 to 31%. Overall, squash bug egg mortality increased as the season progressed.

  10. Assessment of plant biomass and nitrogen nutrition with plant height in early-to mid-season corn.

    Science.gov (United States)

    Yin, Xinhua; Hayes, Robert M; McClure, M Angela; Savoy, Hubert J

    2012-10-01

    The physiological basis for using non-destructive high-resolution measurements of plant height through plant height sensing to guide variable-rate nitrogen (N) applications on corn (Zea mays L.) during early (six-leaf growth stage, V6) to mid (V12) season is largely unknown. This study was conducted to assess the relationships of plant biomass and leaf N with plant height in early- to mid-season corn under six different N rate treatments. Corn plant biomass was significantly and positively related to plant height under an exponential model when both were measured at V6. This relationship explained 62-78% of the variations in corn biomass production. Leaf N concentration was, in general, significantly and positively related to plant height when both were measured at V6, V8, V10 and V12. This relationship became stronger as the growing season progressed from V6 to V12. The relationship of leaf N with plant height in early- to mid-season corn was affected by initial soil N fertility and abnormal weather conditions. The relationship of leaf N concentration with plant height may provide a physiological basis for using plant height sensing to guide variable-rate N applications on corn. Copyright © 2012 Society of Chemical Industry.

  11. Growing energy demand - environmental impact

    International Nuclear Information System (INIS)

    Rama Rao, G.A.

    2012-01-01

    Scientists can bring information, insights, and analytical skills to bear on matters of public concern. Often they can help the public and its representatives to understand the likely causes of events (such as natural and technological disasters) and to estimate the possible effects of projected policies. Often they can testify to what is not possible. Even so, scientists can seldom bring definitive answers to matters of public debate. Some issues are too complex to fit within the current scope of science, or there may be little reliable information available, or the values involved may lie outside of science. Scientists and technologists strive to find an answer to the growing energy demand

  12. Lysine requirements of growing emus.

    Science.gov (United States)

    Mannion, P F; Kent, P B; Barram, K M; Trappett, P C; Blight, G W; Sales, J

    1999-05-01

    1. The lysine requirement of growing emus between 23 and 65 d of age was determined according to growth response variables. 2. The optimal lysine requirement of emus was found to be 0.83 and 0.90 g/MJ ME for growth rate and gain:food ratio respectively. These findings are in accordance with the recommended value of 0.80 g/MJ ME, but is lower than the recommended value for ostriches (1.02 g/MJ ME) and higher than determined values for broilers (0.75 g/MJ ME) of the same age range.

  13. Impacts of the seasonal distribution of rainfall on vegetation productivity across the Sahel

    Science.gov (United States)

    Zhang, Wenmin; Brandt, Martin; Tong, Xiaoye; Tian, Qingjiu; Fensholt, Rasmus

    2018-01-01

    Climate change in drylands has caused alterations in the seasonal distribution of rainfall including increased heavy-rainfall events, longer dry spells, and a shifted timing of the wet season. Yet the aboveground net primary productivity (ANPP) in drylands is usually explained by annual-rainfall sums, disregarding the influence of the seasonal distribution of rainfall. This study tested the importance of rainfall metrics in the wet season (onset and cessation of the wet season, number of rainy days, rainfall intensity, number of consecutive dry days, and heavy-rainfall events) for growing season ANPP. We focused on the Sahel and northern Sudanian region (100-800 mm yr-1) and applied daily satellite-based rainfall estimates (CHIRPS v2.0) and growing-season-integrated normalized difference vegetation index (NDVI; MODIS) as a proxy for ANPP over the study period: 2001-2015. Growing season ANPP in the arid zone (100-300 mm yr-1) was found to be rather insensitive to variations in the seasonal-rainfall metrics, whereas vegetation in the semi-arid zone (300-700 mm yr-1) was significantly impacted by most metrics, especially by the number of rainy days and timing (onset and cessation) of the wet season. We analysed critical breakpoints for all metrics to test if vegetation response to changes in a given rainfall metric surpasses a threshold beyond which vegetation functioning is significantly altered. It was shown that growing season ANPP was particularly negatively impacted after > 14 consecutive dry days and that a rainfall intensity of ˜ 13 mm day-1 was detected for optimum growing season ANPP. We conclude that the number of rainy days and the timing of the wet season are seasonal-rainfall metrics that are decisive for favourable vegetation growth in the semi-arid Sahel and need to be considered when modelling primary productivity from rainfall in the drylands of the Sahel and elsewhere.

  14. 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.

  15. How fast do eels grow

    International Nuclear Information System (INIS)

    Hansen, H.J.M.

    1988-01-01

    Not so very much about the growth pattern of the eel is known yet. Eels move about nearly all the time. They are thus very difficult to follow and we do not, for examble, yet know how long it actually takes for them to grow to maturity in the wild. So far, a macroscopic analysis of the number of bright and dark areas (growth rings) in the 'earstones' has been used to determine eel age, but this method was recently challenged. Use of radioisotopes has been suggested previously for this purpose. For this present study the rare earth elements, europium-152 and europium-155 are used. When incubated in artificial sea water, a satisfactory final radioactive label was achieved. Two experiments were planned in collaboration with the Swedish Environmental Protection Agency. 2000 Elvers were set out in 1982, in the cooling water outlet of the Oskarshamn nuclear power plant, each marked with europium-155. In 1984 another 10 000 elvers labelled with europium-152 were set out under similar conditions. The idea was mainly to see how fast the eels would grow, and to compare their known age with that determined by examining the earstones. Results showed that there was no clear-cut correlation between actual eel age and the biological age determination used so far. During four years, only 10 of the original 1300 eels were recaptured. It is thus hard to say anything definite from our results on the viability of setting out elvers in the environment

  16. Seasonal differences in leaf-level physiology give lianas a competitive advantage over trees in a tropical seasonal forest.

    Science.gov (United States)

    Cai, Zhi-Quan; Schnitzer, Stefan A; Bongers, Frans

    2009-08-01

    Lianas are an important component of most tropical forests, where they vary in abundance from high in seasonal forests to low in seasonal forests. We tested the hypothesis that the physiological ability of lianas to fix carbon (and thus grow) during seasonal drought may confer a distinct advantage in seasonal tropical forests, which may explain pan-tropical liana distributions. We compared a range of leaf-level physiological attributes of 18 co-occurring liana and 16 tree species during the wet and dry seasons in a tropical seasonal forest in Xishuangbanna, China. We found that, during the wet season, lianas had significantly higher CO(2) assimilation per unit mass (A(mass)), nitrogen concentration (N(mass)), and delta(13)C values, and lower leaf mass per unit area (LMA) than trees, indicating that lianas have higher assimilation rates per unit leaf mass and higher integrated water-use efficiency (WUE), but lower leaf structural investments. Seasonal variation in CO(2) assimilation per unit area (A(area)), phosphorus concentration per unit mass (P(mass)), and photosynthetic N-use efficiency (PNUE), however, was significantly lower in lianas than in trees. For instance, mean tree A(area) decreased by 30.1% from wet to dry season, compared with only 12.8% for lianas. In contrast, from the wet to dry season mean liana delta(13)C increased four times more than tree delta(13)C, with no reduction in PNUE, whereas trees had a significant reduction in PNUE. Lianas had higher A(mass) than trees throughout the year, regardless of season. Collectively, our findings indicate that lianas fix more carbon and use water and nitrogen more efficiently than trees, particularly during seasonal drought, which may confer a competitive advantage to lianas during the dry season, and thus may explain their high relative abundance in seasonal tropical forests.

  17. Seasonal groundwater turnover

    OpenAIRE

    Nordell, Bo; Engström, Maria

    2006-01-01

      Seasonal air temperature variations and corresponding changes in groundwater temperature cause convective movements in groundwater similar to the seasonal turnover in lakes. Numerical simulations were performed to investigate the natural conditions for thermally driven groundwater convection to take place. Thermally driven convection could be triggered by a horizontal groundwater flow, Convection then starts at a considerably lower Rayleigh number (Ra) than the general critical Rayleigh ...

  18. Czochralski method of growing single crystals. State-of-art

    International Nuclear Information System (INIS)

    Bukowski, A.; Zabierowski, P.

    1999-01-01

    Modern Czochralski method of single crystal growing has been described. The example of Czochralski process is given. The advantages that caused the rapid progress of the method have been presented. The method limitations that motivated the further research and new solutions are also presented. As the example two different ways of the technique development has been described: silicon single crystals growth in the magnetic field; continuous liquid feed of silicon crystals growth. (author)

  19. Supplies should match growing demand

    International Nuclear Information System (INIS)

    Rasmusen, H.J.

    1997-01-01

    The natural gas industry is currently enjoying healthy growth prospects. Not only is the demand for natural gas steadily growing; the outlook for increasing gas reserves is promising as well. The success of natural gas in the marketplace reflects, on one hand, continuous attention paid to public and customer requirements and, on the other hand, the ability of the gas industry to direct technological developments toward the increasing public demand for gas at competitive market prices supplied in a reliable, safe and environmentally friendly manner. In the past, the gas industry has been involved in the development of technologies for everything from gas production to the end user and from borehole to burner tip, and the author believes that the industry must continue or even increase its emphasis on technology in the future in order to capture new market opportunities. He explains this by looking at the supply side, the demand side and the structural side of the business

  20. Growing Vertical in the Flatland.

    Science.gov (United States)

    Robinson, Joshua A

    2016-01-26

    The world of two-dimensional (2D) heterostructures continues to expand at a rate much greater than anyone could have predicted 10 years ago, but if we are to make the leap from science to technology, many materials challenges must still be overcome. Recent advances, such as those by Liu et al. in this issue of ACS Nano, demonstrate that it is possible to grow rotationally commensurate 2D heterostructures, which could pave the way toward single crystal van der Waals solids. In this Perspective, I provide some insight into a few of the challenges associated with growth of heterostructures, and discuss some of the recent works that help us better understand synthetic realization of 2D heterostructures.

  1. Growing the Blockchain information infrastructure

    DEFF Research Database (Denmark)

    Jabbar, Karim; Bjørn, Pernille

    2017-01-01

    In this paper, we present ethnographic data that unpacks the everyday work of some of the many infrastructuring agents who contribute to creating, sustaining and growing the Blockchain information infrastructure. We argue that this infrastructuring work takes the form of entrepreneurial actions......, which are self-initiated and primarily directed at sustaining or increasing the initiator’s stake in the emerging information infrastructure. These entrepreneurial actions wrestle against the affordances of the installed base of the Blockchain infrastructure, and take the shape of engaging...... or circumventing activities. These activities purposefully aim at either influencing or working around the enablers and constraints afforded by the Blockchain information infrastructure, as its installed base is gaining inertia. This study contributes to our understanding of the purpose of infrastructuring, seen...

  2. Growing bubbles rising in line

    Directory of Open Access Journals (Sweden)

    John F. Harper

    2001-01-01

    Full Text Available Over many years the author and others have given theories for bubbles rising in line in a liquid. Theory has usually suggested that the bubbles will tend towards a stable distance apart, but experiments have often showed them pairing off and sometimes coalescing. However, existing theory seems not to deal adequately with the case of bubbles growing as they rise, which they do if the liquid is boiling, or is a supersaturated solution of a gas, or simply because the pressure decreases with height. That omission is now addressed, for spherical bubbles rising at high Reynolds numbers. As the flow is then nearly irrotational, Lagrange's equations can be used with Rayleigh's dissipation function. The theory also works for bubbles shrinking as they rise because they dissolve.

  3. Aggressiveness Changes in Populations of Didymella pinodes over Winter and Spring Pea Cropping Seasons

    Science.gov (United States)

    Laloi, G.; Montarry, J.; Guibert, M.; Andrivon, D.; Michot, D.

    2016-01-01

    ABSTRACT Ascochyta blight, caused by the necrotrophic ascomycete Didymella pinodes, is responsible for severe losses in winter and spring pea crops. Despite different climatic conditions, epidemics on winter and spring crops are due to a single population of D. pinodes, suggesting gene flow either between the two crops or from reservoir sources during the cropping season. This should lead to similar pathogenicity characteristics in isolates sampled from the two crops. However, these hypotheses have never been formally tested. We therefore sampled a total of 520 D. pinodes strains throughout a growing season from winter and spring pea plots (WP and SP, respectively) and from winter and spring trap plants (TWP and TSP). Amplified fragment length polymorphism (AFLP) markers revealed high genetic diversity within subpopulations, whereas pathogenicity tests showed that mean aggressiveness increases over the course of an epidemic. These results support the idea that alloinoculum contributes to the carryover of epidemics between winter and spring crops and that the most aggressive isolates are selected as an epidemic progresses. IMPORTANCE Ascochyta blight, caused by Didymella pinodes, is responsible for severe losses in pea crops. While previous studies have shown that ascochyta blight epidemics on winter and spring crops are due to a single population of D. pinodes, suggesting that isolates from the two crops present similar pathogenicity characteristics, that hypothesis have never been tested. Genetic analysis of subpopulations sampled throughout a growing season from winter and spring pea plots revealed high genetic diversity within subpopulations, whereas pathogenicity tests showed that mean aggressiveness increases over the course of an epidemic. PMID:27208102

  4. Mechanisms contributing to seasonal homeostasis of minimum leaf water potential and predawn disequilibrium between soil and plant water potential in Neotropical savanna trees.

    Science.gov (United States)

    Sandra J. Bucci; Guillermo Goldstein; Frederick C. Meinzer; Augusto C. Franco; Paula Campanello; Fabián G. Scholz

    2005-01-01

    Seasonal regulation of leaf water potential (ΨL) was studied in eight dominant woody savanna species growing in Brazilian savanna (Cerrado) sites that experience a 5-month dry season. Despite marked seasonal variation in precipitation and air saturation deficit (D), seasonal differences in midday minimum Ψ...

  5. Frequência de suplementação e fontes de proteína para recria de bovinos em pastejo no período seco: desempenho produtivo e econômico Supplementation frequency and proteins sources for growing of steers in pasture during the dry season: productive and economical performance

    Directory of Open Access Journals (Sweden)

    Nelcino Francisco de Paula

    2010-04-01

    effects of the frequency of supplementation with two proteins sources on productive and economical performance (experiment 1 and the nutrients digestibility of steers in supplemented pasture during the dry season over a year. It was used twenty weaned zebu calves at the age of 10 months and initial live weight (LW of 208.43 kg, distributed in four paddocks of Brachiaria brizantha cv. Marandu, each one with 1.6 ha. Both experiments were structured in 2 × 2 factorial arrangement with two supplements (with soybean meal and high energy cottonseed meal. There was no protein sources × supplementation frequency interaction for any of the economical and productive performance traits. The protein sources didn't affect the daily average gain, but the frequency of supply affected performance, which was better in the animals under supplementation at three times a week (0.670 kg /day. The highest economic return was obtained with the offer of supplement with cottonseed meal three times a week. The frequency of supplementation affect the nutrients intake, while the protein source of the supplement had effect only on the ethereal extract intake, which was higher in the animals that consumed the supplement with cottonseed meal. The supplement with high energy cottonseed meal provided higher digestibility of diet crude protein. The supply of supplement three times a week, not only reduces the costs of supplementation, but it possibilities a higher performance than the one obtained with daily supplementation. The use of higher energy cottonseed meal in multiple supplements replacing soybean meal is satisfactory mainly under economical point of view.

  6. Measuring progress

    DEFF Research Database (Denmark)

    Wahlberg, Ayo

    2007-01-01

    In recent years, sociological examinations of genetics, therapeutic cloning, neuroscience and tissue engineering have suggested that 'life itself' is currently being transformed through technique with profound implications for the ways in which we understand and govern ourselves and others....... In this paper, I argue that a growing focus on frontier technologies in the life sciences in discussions about bio-power today has come at the cost of empirical investigations into how, for example, 'quality of life' came to be a crucial object of bio-power in the 20th century. Just as Foucault outlined...

  7. Growing halophytes floating at sea

    Directory of Open Access Journals (Sweden)

    Ricardo Radulovich

    2017-11-01

    Full Text Available Freshwater shortages are increasingly limiting both irrigated and rainfed agriculture. To expand possibilities for controlled plant production without using land nor freshwater, we cultivated potted halophytes floating at sea that were provided with rain- and seawater. Plantlets of two mangroves (Avicennia germinans and Rhizophora mangle and plants of two herbaceous species, sea purslane (Sesuvium portulacastrum and salt couch grass (Sporobolus virginicus were grown in near-coastal tropical Pacific waters of Costa Rica for 733 days. There were a total of 504 rainless days, including two dry periods of ca. 150 d long each, evidencing prolonged and exclusive reliance on seawater. Pots with a sandy soil mixture and the transplanted plants were placed on low-cost wooden floating rafts with their lower end perforated and immersed for capillary rise of water. Free seawater entry and exit through the bottom from bobbing with waves, which also occasionally added water from the top, effectively controlled soil salinity build-up even during the rainless seasons. Continuous leaching made necessary frequent fertilizer addition. No water deficit symptoms were observed and midday canopy temperature during rainless periods was not significantly different between species or from air temperature. With all-year-round growth, height increase of mangrove plantlets ranged from 208.1 to 401.5 mm yr−1. Fresh biomass production of sea purslane and the grass was 10.9 and 3.0 kg m−2 yr−1 respectively. High yield, edibility and protein content of 10.2% dry weight established sea purslane as a potential crop. While further research is needed, the method evidenced to be a viable plant production option of potentially far-reaching applications.

  8. Mood disorders and season ofpresentation

    African Journals Online (AJOL)

    A preliminary study of an inpatient sample at Baragwanath Hospital. Mood disorders and season ofpresentation. C.P. SZABO. The relationship between season and nlOod is cmnplex. This study attempts to clarify one aspect ofthe relationship: the impact of season on mood in terms of the hypothesised seasonal variation in.

  9. Seasonal hydroclimatic impacts of Sun Corridor expansion

    International Nuclear Information System (INIS)

    Georgescu, M; Mahalov, A; Moustaoui, M

    2012-01-01

    Conversion of natural to urban land forms imparts influence on local and regional hydroclimate via modification of the surface energy and water balance, and consideration of such effects due to rapidly expanding megapolitan areas is necessary in light of the growing global share of urban inhabitants. Based on a suite of ensemble-based, multi-year simulations using the Weather Research and Forecasting (WRF) model, we quantify seasonally varying hydroclimatic impacts of the most rapidly expanding megapolitan area in the US: Arizona’s Sun Corridor, centered upon the Greater Phoenix metropolitan area. Using a scenario-based urban expansion approach that accounts for the full range of Sun Corridor growth uncertainty through 2050, we show that built environment induced warming for the maximum development scenario is greatest during the summer season (regionally averaged warming over AZ exceeds 1 °C). Warming remains significant during the spring and fall seasons (regionally averaged warming over AZ approaches 0.9 °C during both seasons), and is least during the winter season (regionally averaged warming over AZ of 0.5 °C). Impacts from a minimum expansion scenario are reduced, with regionally averaged warming ranging between 0.1 and 0.3 °C for all seasons except winter, when no warming impacts are diagnosed. Integration of highly reflective cool roofs within the built environment, increasingly recognized as a cost-effective option intended to offset the warming influence of urban complexes, reduces urban-induced warming considerably. However, impacts on the hydrologic cycle are aggravated via enhanced evapotranspiration reduction, leading to a 4% total accumulated precipitation decrease relative to the non-adaptive maximum expansion scenario. Our results highlight potentially unintended consequences of this adaptation approach within rapidly expanding megapolitan areas, and emphasize the need for undeniably sustainable development paths that account for

  10. Iodine Emissions from Seaweeds: Species-dependent and Seasonal Differences

    Science.gov (United States)

    Adams, Thomas; Ball, Stephen; Leblanc, Catherine; Potin, Philippe

    2015-04-01

    Emissions of iodine from macroalgae into the marine boundary layer (MBL) significantly impact tropospheric chemistry and the biogeochemical cycling of iodine. Gas-phase iodine chemistry perturbs the usual HOx and NOx radical cycles, provides additional sink reactions for tropospheric ozone, and modifies atmospheric oxidizing capacity. Iodine oxides (IxOywith x ≥ 2) formed through the reaction of iodine atoms with ozone nucleate new aerosol particles which, if they grow sufficiently, can act as cloud condensation nuclei (CCN) and so influence the local climate in coastal regions. Some seaweeds, such as brown algae, are important bio-accumulators of iodine. They specifically induce iodine metabolism to protect themselves against oxidative stress, both as a defence mechanism and when exposed to air around low tide. Indeed the dominant emission source of iodine into the atmosphere in coastal regions comes from intertidal macroalgal beds, particularly those of kelp species. We present results from an extensive laboratory study of molecular iodine (I2) emissions from five seaweed species (two Fucales, Ascophyllum nodosum and Fucus vesiculosus, and three kelp species, Laminaria digitata, L. hyperborea and Saccharina latissima). Eighty-four incubation experiments were performed at the Station Biologique in Roscoff (Brittany, France) between September 2012 and June 2013 to quantify species-dependent I2 emission rates in response to progressive air exposure, mimicking low tide, and to investigate any seasonal differences. Measurements were conducted on 'fresh' biological samples: Ascophyllum and Fucus thalli were collected whilst still submerged on an ebbing tide, transported in seawater to the laboratory and analysed immediately; kelp samples were collected by boat, stored in an outside aquarium in running seawater and analysed within a few days. I2 emissions were quantified at high time resolution by broadband cavity enhanced absorption spectrometry (1σ detection limit

  11. Seasonality of volcanic eruptions

    Science.gov (United States)

    Mason, B. G.; Pyle, D. M.; Dade, W. B.; Jupp, T.

    2004-04-01

    An analysis of volcanic activity during the last three hundred years reveals that volcanic eruptions exhibit seasonality to a statistically significant degree. This remarkable pattern is observed primarily along the Pacific "Ring of Fire" and locally at some individual volcanoes. Globally, seasonal fluctuations amount to 18% of the historical average monthly eruption rate. In some regions, seasonal fluctuations amount to as much as 50% of the average eruption rate. Seasonality principally reflects the temporal distribution of the smaller, dated eruptions (volcanic explosivity index of 0-2) that dominate the eruption catalog. We suggest that the pattern of seasonality correlates with the annual Earth surface deformation that accompanies the movement of surface water mass during the annual hydrological cycle and illustrate this with respect to global models of surface deformation and regional measurements of annual sea level change. For example, seasonal peaks in the eruption rate of volcanoes in Central America, the Alaskan Peninsula, and Kamchatka coincide with periods of falling regional sea level. In Melanesia, in contrast, peak numbers of volcanic eruptions occur during months of maximal regional sea level and falling regional atmospheric pressure. We suggest that the well-documented slow deformation of Earth's surface that accompanies the annual movements of water mass from oceans to continents acts to impose a fluctuating boundary condition on volcanoes, such that volcanic eruptions tend to be concentrated during periods of local or regional surface change rather than simply being distributed randomly throughout the year. Our findings have important ramifications for volcanic risk assessment and volcanoclimate feedback mechanisms.

  12. Short-term effects of burn season on flowering phenology of savanna plants

    Science.gov (United States)

    Pavlovic, N.B.; Leicht-Young, S. A.; Grundel, R.

    2011-01-01

    We examined the effect of season of burn on flowering phenology of groundlayer species, in the year following burns, in a mesic-sand Midwestern oak savanna. Burn treatments were fall, early-season, growing-season, late-season, and 1 or 5 years after a prior early-season wildfire. For these treatments, we compared the number of flowering stems and of flowers for species overall, for the 20 most prolifically flowering species, as well as for species grouped by flowering phenoperiods, and by growth form. Growing-season burn had a significant negative effect on number of flowering stems and total number of flowers. This effect occurred when either the burn occurred during the flowering season or during the season prior to the flowering phenoperiod. Tradescantia ohiensis showed expedited flowering and Phlox pilosa showed delayed flowering in response to early-season burning. Flowering of early shrubs was reduced by the previous fall and early-spring fires, while flowering of mid-season blooming shrubs was reduced by the early- and growing-season burns. Vaccinium and Gaylussacia, early-flowering shrubs, produced fewer flowers 1 year after than 5 years after an early-season burn. Arabis lyrata showed reduced flowering from the early-season burn. We also found four instances where the early-spring burn effect on flowering was more severe than the fall burn effect, suggesting that many frequent early-season burns may be deleterious to flowering and reproduction of some species. Burns occurring too frequently in the same season could negatively affect future flowering and reproduction of these plant species.

  13. Growth form and seasonal variation in leaf gas exchange of Colophospermum mopane savanna trees in northwest Botswana.

    Science.gov (United States)

    Veenendaal, Elmar M; Mantlana, Khanyisa B; Pammenter, Norman W; Weber, Piet; Huntsman-Mapila, Phillipa; Lloyd, Jon

    2008-03-01

    We investigated differences in physiological and morphological traits between the tall and short forms of mopane (Colophospermum mopane (Kirk ex Benth.) Kirk ex J. Léonard) trees growing near Maun, Botswana on a Kalahari sandveld overlying an impermeable calcrete duricrust. We sought to determine if differences between the two physiognomic types are attributable to the way they exploit available soil water. The tall form, which was located on deeper soil than the short form (5.5 versus 1.6 m), had a lower leaf:fine root biomass ratio (1:20 versus 1:6), but a similar leaf area index (0.9-1.0). Leaf nitrogen concentrations varied between 18 and 27 mg g(-1) and were about 20% higher in the tall form than in the short form. Maximum net assimilation rates (A sat) occurred during the rainy seasons (March-April 2000 and January-February 2001) and were similar in the tall and short forms (15-22 micromol m(-2) s(-1)) before declining to less than 10 micromol m(-2) s(-1) at the end of the rainy season in late April. As the dry season progressed, A sat, soil water content, predawn leaf water potential (Psi pd) and leaf nitrogen concentration declined rapidly. Before leaf abscission, Psi pd was more negative in the short form (-3.4 MPa) than in the tall form (-2.7 MPa) despite the greater availability of soil water beneath the short form trees. This difference appeared attributable to differences in root depth and density between the physiognomic types. Stomatal regulation of water use and carbon assimilation differed between years, with the tall form having a consistently more conservative water-use strategy as the dry season progressed than the short form.

  14. Bariatric amputee: A growing problem?

    Science.gov (United States)

    Kulkarni, Jai; Hannett, Dominic P; Purcell, Steven

    2015-06-01

    This study reviewed prevalence of patients with lower limb amputations with above normal weight profile, with body mass index over 25, in seven disablement services centres managing their amputee rehabilitation in the United Kingdom. To review two clinical standards of practice in amputee rehabilitation. Ambulant lower limb amputees should have their body weight recorded on an electronic information system, with identification of cohort with body weight >100 kg. Lower limb amputees to be provided with suitable weight-rated prosthesis. Observational study of clinical practice. Data were collected from the Clinical Information Management Systems. Inclusion criteria--subjects were ambulant prosthetic users with some prosthetic intervention in the last 5 years and had at least one lower limb amputation. In 96% of patients, the weight record profile was maintained. In addition, 86% were under 100 kg, which is the most common weight limit of prosthetic componentry. Of 15,204 amputation levels, there were 1830 transfemoral and transtibial sites in users with body weight over 100 kg. In 60 cases, the prosthetic limb build was rated to be below the user body weight. In 96% of our patients, body weight was documented, and in 97%, the prosthetic limb builds were within stated body weight limits, but this may not be the case in all the other disablement services centres in the United Kingdom. Also, the incidence of obesity in the United Kingdom is a growing problem, and the health issues associated with obesity are further compounded in the amputee population. Prosthetic componentry has distinct weight limits which must be considered during prescription. As people with amputation approach the limits of specific components, clinicians are faced with the challenge of continued provision in a safe and suitable manner. This article reviews the amputee population and the current national profile to consider trends in provision and the incidence of these challenges. © The

  15. Growing population causes of unemployment.

    Science.gov (United States)

    1995-01-01

    At the March, 1995, International Meeting on Population and Social Development in Copenhagen, during the session on unemployment, underemployment, and population it was stated that the problem of employment was the extent to which a nation's labor supply was not matched by labor demand or job opportunities. Population was thus a supply factor, and the country's economic situation was a demand factor. The demographic variables that were considered important in the supply of labor were: a) the size and rate of growth of the population, which was a function of the birth rate, the death rate, and migration; and b) the age structure of the population, which was also a product of the rate of growth of the population and its distribution. An imbalance between the supply of labor and the demand for it gave rise to unemployment and underemployment. The vicious cycle generated by a high dependency burden associated with a young age-structure led to low savings and investments, which in turn led to low economic growth and a low standard of living. This produced high fertility rates, which in turn heightened the dependency burden perpetuating the cycle. This vicious cycle could be broken at only two points: at the high fertility stage, primarily by introducing family planning programs; and at the stage of low economic growth, by adopting policies to accelerate economic growth. To be successful, however, both actions had to be pursued simultaneously. Numerous participants emphasized the global nature of the issue of unemployment and underemployment; the effects of international competition and restrictive trade policies on employment opportunities. The growing disparity between North and South had created a social injustice between countries. Several participants called for more humane policies that favored democracy and promoted human development, and asked for assistance to help create an enabling environment for social and economic development.

  16. Protein nutrition of growing cattle

    International Nuclear Information System (INIS)

    Chalupa, W.; Scott, G.C.

    1976-01-01

    In vitro studies on apparent degradation of amino acids by mixed and pure cultures of rumen bacteria demonstrated that (a) amino acids are degraded at differing rates (Arg, Thr>Lys, Phe, Leu, Ile>Val, Met); (b) certain amino acids (Met, Val, Try, Orn) are degraded to greater extents when fermented alone than in conjunction with other amino acids; (c) individual strains of rumen bacteria do not utilize all amino acids; and (d) total ruminal degradation of amino acids is the result of extensive bacterial interaction, and may vary greatly depending on the predominant types of micro-organisms present. Abomasal infusion of a mixture of 10 essential amino acids consistently increased nitrogen retention, but attempts to elucidate primary limiting amino acids were not conclusive. Our data suggested that supplementary methionine alone may not significantly increase nitrogen retention, but methionine must be present in order to obtain responses from other amino acids. Methionine plus lysine plus threonine usually increased nitrogen retention, but the magnitude of responses varied. The classical nitrogen balance technique may lack the sensitivity needed to detect small responses resulting from supplements of single amino acids, or growing cattle, unlike sheep used for wool growth, may not be suffering from specific amino acid deficiencies. Chemical suppression of ruminal degradation of amino acids produced significant increases in nitrogen retention and growth, and improved feed efficiencies. Productivity responses to rumen bypass techniques would seem to depend primarily upon (a) the degree to which dietary protein is degraded in the rumen, and (b) the quantity of absorbable amino acids supplied by the diet in relation to quantities required by the animal. (author)

  17. Menopausal women's positive experience of growing older

    DEFF Research Database (Denmark)

    Hvas, Lotte

    2006-01-01

    This paper aims to describe menopausal women's positive experience of growing older and becoming middle-aged.......This paper aims to describe menopausal women's positive experience of growing older and becoming middle-aged....

  18. Progressivity Enhanced

    Directory of Open Access Journals (Sweden)

    Marko Hren

    2013-09-01

    Full Text Available Rather than a scientific text, the author contributes a concise memorandum from the originator of the idea who has managed the campaign for the conversion of the military barracks into a creative cluster between 1988 and 2002, when he parted ways with Metelkova due to conflicting views on the center’s future. His views shed light on a distant period of time from a perspective of a participant–observer. The information is abundantly supported by primary sources, also available online. However, some of the presented hypotheses are heavily influenced by his personal experiences of xenophobia, elitism, and predatorial behavior, which were already then discernible on the so-called alternative scene as well – so much so that they obstructed the implementation of progressive programs. The author claims that, in spite of the substantially different reality today, the myths and prejudices concerning Metelkova must be done away with in order to enhance its progressive nature. Above all, the paper calls for an objective view on internal antagonisms, mainly originating in deep class divisions between the users. These make a clear distinction between truly marginal ndividuals and the overambitious beau-bourgeois, as the author labels the large part of users of Metelkova of »his« time. On these grounds, he argues for a robust approach to ban all forms of xenophobia and self-ghettoization.

  19. Nutritional studies on growing rabbits

    International Nuclear Information System (INIS)

    Hassan, A.M.E.A.M.

    2013-01-01

    This work was carried out to study the effect of adding drinking water with either, copper sulfate, ascorbic acid or drinking cooled water on growth performance (live body weight,body weight gain, feed intake, feed conversion and water consumption), digestibility coefficients of nutrients, carcass traits, some physiological parameters and economical efficiency of growing NZW rabbits under Egyptian summer conditions. Ninety six weanling New Zealand White (NZW) male rabbits at five weeks of age and nearly similar average body weight (650.3 ±3.7 g) were randomly divided into eight treatment groups (twelve rabbits in each group), and then each group was subdivided into four replicates, each of three rabbits. The rabbits were assigned to drinking water as follow: the 1 st group was given fresh tap water without any additives as a control. The 2 n d, 3 r d and 4 t h groups were given tap fresh water supplemented with copper sulfate at levels of 40, 80 and 120 mg/L drinking water, respectively. The 5 t h, 6 t h and 7 t h groups were given tap fresh water supplemented with ascorbic acid at levels of 250, 500 and 750 mg/L drinking water, respectively. The 8 t h group was given cooled drinking water (CW) at 10-15 degree C. Results showed that supplementation of 40 or 80 mg copper sulfate/L or 500 mg ascorbic acid/L to heat-stressed rabbits drinking water improved final live body weight, body weight gain, daily water consumption, feed conversion ratio, performance index and economical efficiency. Hot carcass percentage was significantly (P<0.01) decreased with 80 mg/L copper sulfate and increased significantly (P<0.01) due to supplementation the drinking water with 250 mg ascorbic acid/L. Cooled water (10-15 degree C) improved significantly (P<0.01) each of final body weight, body weight gain, feed conversion ratio, performance index, economical efficiency and decreased significantly (P<0.01) each of hot carcass %, dressed weight %, heart %, total giblets %, rectal

  20. A method to identify potential cold-climate vine growing sites

    DEFF Research Database (Denmark)

    Olsen, Jørgen L; Olesen, Asger; Breuning-Madsen, Henrik

    2011-01-01

    ) Sum of growing degree days (SDD), ii) Risk of frost damage, iii) Number of sunshine hours during growth season, and iv) Soil drainage. A two-step method based on GIS and already existing climate, soil, and topographic data was implemented. First the most suitable areas in Denmark for vine growing were...... located on the basis of nation-wide climatic data on the sum of degree days and risk of frost. Within the most suitable areas a detailed survey of the amount of sunshine, topography, drainage and soil was carried out on the Røsnæs peninsula in north western Zealand, and eight well-suited vine growing...

  1. Warning Signs: Seasonal Flu

    Centers for Disease Control (CDC) Podcasts

    2010-09-29

    In this podcast, Dr. Joe Bresee describes the main symptoms of seasonal flu and when it is serious enough to seek medical help.  Created: 9/29/2010 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 9/29/2010.

  2. Take Three: Seasonal Flu

    Centers for Disease Control (CDC) Podcasts

    2010-09-29

    In this podcast, Dr. Joe Bresee describes how to keep from getting seasonal flu and spreading it to others by taking these three steps.  Created: 9/29/2010 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 9/29/2010.

  3. Seasonal atmospheric extinction

    International Nuclear Information System (INIS)

    Mikhail, J.S.

    1979-01-01

    Mean monochromatic extinction coefficients at various wavelengths at the Kottamia Observatory site have shown the existence of a seasonal variation of atmospheric extinction. The extinction of aerosol compontnts with wavelengths at winter represent exceedingly good conditions. Spring gives the highest extinction due to aerosol. (orig.)

  4. Seasonal Affective Disorder

    Science.gov (United States)

    ... available on the prevalence and treatment of severe depression among adolescents in the U.S. Multimedia Twitter Chat on Seasonal ... News NIMH to Host Twitter Chat on Teen Depression Hubs Help Native American Communities Address Youth Suicide Disorders Share Molecular Signatures More Contact Us The ...

  5. Antiviral Drugs: Seasonal Flu

    Centers for Disease Control (CDC) Podcasts

    2010-09-29

    In this podcast, Dr. Joe Bresee explains the nature of antiviral drugs and how they are used for seasonal flu.  Created: 9/29/2010 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 9/29/2010.

  6. Seasonal Influenza: An Overview

    Science.gov (United States)

    Li, Christina; Freedman, Marian

    2009-01-01

    Seasonal influenza is a major cause of morbidity and mortality in the United States. It also has major social and economic consequences in the form of high rates of absenteeism from school and work as well as significant treatment and hospitalization costs. In fact, annual influenza epidemics and the resulting deaths and lost days of productivity…

  7. The Hungry Season

    African Journals Online (AJOL)

    start to go some way towards addressing this fundamental question. A delightful animation of The Hungry Season, commissioned by Leonie Joubert and funded by the University of Cape Town's Criminology. Department and the Embassy of Finland, is available online at http://www.youtube.com/ watch?v=iX77NZttLKo.

  8. Photosynthetic properties of C4 plants growing in an African savanna/wetland mosaic

    NARCIS (Netherlands)

    Mantlana, K.B.; Arneth, A.; Veenendaal, E.M.; Wohland, P.; Wolski, P.; Kolle, O.; Wagner, M.; Lloyd, J.

    2008-01-01

    Photosynthesis rates and photosynthesis-leaf nutrient relationships were analysed in nine tropical grass and sedge species growing in three different ecosystems: a rain-fed grassland, a seasonal floodplain, and a permanent swamp, located along a hydrological gradient in the Okavango Delta, Botswana.

  9. Soil K Status and K Requirement of Potato Growing on Different ...

    African Journals Online (AJOL)

    An experiment was conducted in 2005/06 and 2006/07 cropping seasons on Nitosols, Acrisols and Luvisols of Western Amhara to investigate the inherent soil K status and K requirement of potato growing on ·these soils. The field experiments were conduckd in Yilmana Densa (West Gojjam Zone), Farta (South Gondar ...

  10. Modeling phosphorus capture by plants growing in a multi-species riparian buffer

    Science.gov (United States)

    The NST 3.0 mechanistic nutrient uptake model was used to explore phosphorus (P) uptake to a depth of 120 cm over a 126-d growing season in simulated buffer communities composed of mixtures of cottonwood (Populus deltoids Bartr.), switchgrass (Panicum virgatum L.), and smooth brome (Bromis inermis L...

  11. Assessing the potentials of growing Samcot 9 Cotton variety in Kano ...

    African Journals Online (AJOL)

    A Completely randomized field experiment with nine replications was conducted in the North, South and Central Agricultural zones of Kano State during the 2004 cotton growing season with a control in Katsina state, a cotton producing area, with the object of assessing the potentials of the profitable production of the ...

  12. Growing spearmint, thyme, oregano, and rosemary in Northern Wyoming using plastic tunnels

    Science.gov (United States)

    Growing perennial herbs in northern climate such as Northern Wyoming is a challenge. Due to short frost-free period, high wind, and inclement weather it is impossible to harvest any herbs twice a year (summer and late fall) without using any form of season extension methods. Hence, we set up an expe...

  13. Potential for western US seasonal snowpack prediction

    Science.gov (United States)

    Kapnick, Sarah B.; Yang, Xiaosong; Vecchi, Gabriel A.; Delworth, Thomas L.; Gudgel, Rich; Malyshev, Sergey; Milly, Paul C.; Shevliakova, Elena; Underwood, Seth; Margulis, Steven A.

    2018-01-01

    Western US snowpack—snow that accumulates on the ground in the mountains—plays a critical role in regional hydroclimate and water supply, with 80% of snowmelt runoff being used for agriculture. While climate projections provide estimates of snowpack loss by the end of th ecentury and weather forecasts provide predictions of weather conditions out to 2 weeks, less progress has been made for snow predictions at seasonal timescales (months to 2 years), crucial for regional agricultural decisions (e.g., plant choice and quantity). Seasonal predictions with climate models first took the form of El Niño predictions 3 decades ago, with hydroclimate predictions emerging more recently. While the field has been focused on single-season predictions (3 months or less), we are now poised to advance our predictions beyond this timeframe. Utilizing observations, climate indices, and a suite of global climate models, we demonstrate the feasibility of seasonal snowpack predictions and quantify the limits of predictive skill 8 month sin advance. This physically based dynamic system outperforms observation-based statistical predictions made on July 1 for March snowpack everywhere except the southern Sierra Nevada, a region where prediction skill is nonexistent for every predictor presently tested. Additionally, in the absence of externally forced negative trends in snowpack, narrow maritime mountain ranges with high hydroclimate variability pose a challenge for seasonal prediction in our present system; natural snowpack variability may inherently be unpredictable at this timescale. This work highlights present prediction system successes and gives cause for optimism for developing seasonal predictions for societal needs.

  14. Seasonal variation in chemical composition, aroma volatiles and ...

    African Journals Online (AJOL)

    This study was conducted to investigate compositional changes and antioxidant capacities of pomegranate fruit ('Bhagwa' and 'Ruby') at five distinct stages of maturity over two growing seasons. Total soluble solids (TSS), pH, titratable acidity (TA), phenolic concentrations, antioxidant capacity and aroma volatile ...

  15. Progress report

    International Nuclear Information System (INIS)

    Brumovsky, M.

    1979-01-01

    Progress Report, covering the period up to the end of 1979 year, was sent to the IAEA according to the research agreement No. 1971 /CF. This work covered the following fields: preparation and dummy irradiation experiments with a new experimental capsule of ''CHOUCA-M'' type; measurement of temperature fields and design of specimen holders; measurement of neutron energy spectrum in the irradiation place in our experimental reactor of VVR-S type (Nuclear Research Institute) using a set of activation detectors; unification and calibration of the measurement of neutron fluence with the use of Fe, Cu, Mn-Mg and Co-Al monitors; development and improvement of the measuring apparatus and technique for the dynamic testing of pre-cracked specimens with determination of dynamic parameters of fracture mechanics; preparation and manufacture of testing specimens from the Japanese steels - forging, plate and weld metal; preparation of the irradiation capsule for assembling

  16. Seasonal trend of acute pelvic inflammatory disease.

    Science.gov (United States)

    Xholli, Anjeza; Cannoletta, Marianna; Cagnacci, Angelo

    2014-05-01

    Many infections follow a seasonal trend. Aim of our study was to check whether acute pelvic inflammatory disease (PID) follows a seasonal progress. In a retrospective study on 12,152 hospital records, 158 cases of acute pelvic inflammatory disease were identified. Periodogram analysis was applied to the date of pelvic inflammatory disease admission and to related environmental factors, such as temperature and photoperiod. Pelvic inflammatory disease follows a seasonal rhythm with mean to peak variation of 23 % and maximal values in September (±37.2 days). The rhythm, more evident in married women, is related to the rhythm of temperature advanced by 2 months and of photoperiod advanced by 3 months. Cases of pelvic inflammatory disease are more frequent than expected in unmarried (36 vs. 17.3/34,626, p = 0.015), particularly divorced women 30-40 years of age. Our study evidences a seasonal trend and confirms unmarried, particularly divorced status, as important risk factor for acute pelvic inflammatory disease.

  17. Nutrient uptake and distribution in young Pinot noir grapevines over two seasons

    Science.gov (United States)

    The seasonal timing of biomass and nutrient uptake and distribution among different vine organs was determined over two growing seasons in 4-year-old Pinot noir grapevines carrying their first full crop and grown in field microplots. Vines were fertilized in spring and the biomass and nutrient conte...

  18. PRODUCTIVITY OF GROWING PONDS WHEN APPLYING THE BACTERIAL FERTILIZER «PHOSPHOBAKTERIN»

    Directory of Open Access Journals (Sweden)

    Т. Hryhorenko

    2017-09-01

    Full Text Available Purpose. To investigate the effect of the bacterial fertilizer "Phosphobacterin" on the formation of the hydrochemical regime, development of the natural food supply and fish productivity in the growing ponds. Methodology. The work was conducted according to generally accepted hydrochemical,, microbiological, hydrobiological and fish farming methods. Findings The article presents the results of a study of the productivity of growing ponds with different methods of the application of the bacterial fertilizer "Phosphobacterin". It was found that the hydrochemical regime of the experimental ponds was formed under the effect of the source of water supply and measures aimed at intensifying the development of the natural food supply and was favorable for the development of feed organisms and the cultivation of fish seeds. Application of the bacterial fertilizer at the beginning of the growing season along the water pond surface proved to be little effective for increasing the productivity of the pond ecosystem as a whole. A more effective method of increasing biological productivity, including fish productivity of growing ponds, was the application of "Phosphobacterin" during the growing season both on the bed and on the water surface in combination with the organic fertilizer - cattle humus. In the experimental pond under complex fertilization, the average phytoplankton biomass during the growing season was 1.5 times, bacterioplankton 1.1 times, zoobenthos 2.6 times higher, and the obtained total fish productivity was 1.2 times higher than in the control pond (when applying only cattle humus. Originality. The peculiarities of formation of hydrochemical and hydrobiological (phyto-, bacterio-, zooplankton, zoobenthos regimes of growing ponds and the fishery indices are studied, both for bacterial fertilizer "Phosphobacterin" independently and together with the traditional organic fertilizer - cattle humus. Practical value. Based on the obtained results

  19. Aerodynamic parameter changes above a young spruce forest stand during five growing seasons

    Czech Academy of Sciences Publication Activity Database

    Hurtalová, T.; Matejka, F.; Rožnovský, J.; Marková, Irena; Janouš, Dalibor

    2004-01-01

    Roč. 34, č. 2 (2004), s. 131-146 ISSN 1335-2806 R&D Projects: GA ČR(CZ) GA526/00/0485 Keywords : aerodynamic parameters * roughness length * young spruce stand Subject RIV: DG - Athmosphere Sciences, Meteorology

  20. Growing Season Definition and Use in Wetland Delineation: A Literature Review

    Science.gov (United States)

    2010-08-01

    germinate . The rationale for below-ground temperature standards is based in agricultural practices. The concept is that soil temperature influences root...1984), and the germination and emergence of multiple plant species (Carberry and Campbell 1989; Jordan and Haferkamp 1989). Temperature influences...as well as privet (Ligustrum japonicum), loblolly pine ( Pinus taeda), and yellow poplar (Liriodendron tulipifera). The lack of water uptake was

  1. The influence of rest period during the growing season on the ...

    African Journals Online (AJOL)

    The material from exclusion cages was clipped at the end of the grazing period according to the grazing pattern of the adjacent area of the plot. These clippings were analyzed for crude protein, in vitro dry maller digestibility and acid detergent fibre content. The in vitro dry matter digestibility values were relatively normal.

  2. Transmittance of young Norway spruce stand canopy for photosynthetically active radiation during the growing season

    Czech Academy of Sciences Publication Activity Database

    Marková, I.; Kubásek, Jiří

    2013-01-01

    Roč. 61 /16/, č. 1 (2013), s. 129-136 ISSN 1211-8516 R&D Projects: GA MŠk(CZ) LM2010007; GA MŠk(CZ) EE2.4.31.0056 Institutional support: RVO:67179843 Keywords : overcast and clear days * phonological phases Subject RIV: EH - Ecology, Behaviour

  3. Winter and growing season nitrogen mineralization from fall-applied composted or stockpiled solid dairy manure

    Science.gov (United States)

    Adequate characterization of nitrogen (N) mineralization with time from manure and other organic sources is needed to maximize manure N use efficiency, decrease producer costs, and protect groundwater quality. The objective of our two-year field study at Parma, ID, was to quantify in situ N mineral...

  4. Forest ecosystem as a source of CO2 during growing season: relation to weather conditions

    Czech Academy of Sciences Publication Activity Database

    Taufarová, Klára; Havránková, Kateřina; Dvorská, Alice; Pavelka, Marian; Urbaniak, M.; Janouš, Dalibor

    2014-01-01

    Roč. 28, č. 2 (2014), s. 239-249 ISSN 0236-8722 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073; GA MŠk(CZ) EE2.4.31.0056; GA MŠk(CZ) LM2010007 Institutional support: RVO:67179843 Keywords : net ecosystem production * CO2 source days * eddy covariance * weather conditions * Norway spruce Subject RIV: EH - Ecology, Behaviour Impact factor: 1.117, year: 2014

  5. Copper Root Pruning and Container Cavity Size Influence Longleaf Pine Growth through Five Growing Seasons

    Science.gov (United States)

    James D. Haywood; Shi-Jean Susana Sung; Mary Anne Sword Sayer

    2012-01-01

    However, type and size of container can influence field performance. In this study, longleaf pine seedlings were grown in Beaver Plastics Styroblocks either without a copper treatment (Superblock) or with a copper oxychloride coating (Copperblock) and with three sizes of cavities that were 60, 108, and 164 ml. Seedlings from the six container types (two types of...

  6. Radionuclide concentrations in vegetation at radioactive-waste disposal Area G during the 1994 growing season

    International Nuclear Information System (INIS)

    Fresquez, P.R.; Biggs, J.B.; Bennett, K.D.

    1995-01-01

    Overstory (pinon pine) and understory (grass and forb) vegetation samples were collected within and around selected points at Area G-a low-level radioactive solid-waste disposal facility at Los Alamos National Laboratory-for the analysis of tritium ( 3 H), strontium ( 90 Sr), plutonium ( 238 Pu and 239 Pu), cesium ( 137 Cs), americium ( 241 Am), and total uranium. In general, most vegetation samples collected within and around Area G contained radionuclide levels in higher concentrations than vegetation collected from background areas. Tritium, in particular, was detected as high as 5,800 pCi/mL in overstory vegetation collected outside the fence just west of the tritium shafts; this suggests that tritium is migrating from this waste repository through subsurface pathways. Also, understory vegetation collected north of the transuranic (TRU) pads (outside the fence of Area G) contained the highest values of 90 Sr, 238 Pu, 239 Pu, 137 Cs, and 241 Am, and may be a result of surface holding, storage, or disposal activities

  7. A Psychological Model Of Scenic Beauty By Silvicultural Treatment Two Growing Seasons After Harvest

    Science.gov (United States)

    Ying-Hung Li; Victor A. Rudis; Theresa A. Herrick

    2004-01-01

    Abstract - This study estimated summer scenic beauty and associated psychological attributes of scenes depicting uncut and several cutting regimes within shortleaf pine-hardwood forests on national forests. Images were captured in the summer of 1994 in nine treated and three comparable untreated stands in the Ouachita Mountains of Arkansas....

  8. Spatial Variation In Growing Season Heat Sums Within Northern Hardwood Forest Canopy Gaps

    Science.gov (United States)

    Brian E. Potter; Paul J. Croft

    2000-01-01

    When a gap forms in a forest canopy, the first and most immediate effect on the exposed area is an increase in radiative exchange near the ground. More sunlight reaches the ground during the daytime, and at nighttime the ground is more exposed to longwave radiation influences from the sky. These changes in radiation lead directly to a different near-ground temperature...

  9. Exposure to Atrazine and Selected Non-Persistent Pesticides among Corn Farmers during a Growing Season

    Science.gov (United States)

    Bakke, Berit; De Roos, Anneclaire J.; Barr, Dana B.; Stewart, Patricia A.; Blair, Aaron; Freeman, Laura Beane; Lynch, Charles F.; Allen, Ruth H.; Alavanja, Michael C.R.; Vermeulen, Roel

    2011-01-01

    Objectives The aim was to develop quantitative estimates of farmers’ pesticide exposure to atrazine and to provide an overview of background levels of selected non-persistent pesticides among corn farmers in a longitudinal molecular epidemiologic study. Methods The study population consisted of 30 Agricultural Health Study farmers from Iowa and 10 nonfarming controls. Farmers completed daily and weekly diaries from March to November in 2002 and 2003 on pesticide use and other exposure determinants. Urine samples were collected at 10 timepoints relative to atrazine application and other farming activities. Pesticide exposure was assessed using urinary metabolites and diaries. Results The analytical limit of detection (LOD) ranged between 0.1–0.2 μg/l for all pesticide analytes except for isazaphos (1.5 μg/l) and diazinon (0.7 μg/l). Farmers had higher geometric mean urinary atrazine mercapturate (AZM) values than controls during planting (1.1 vs. urine collection (38% vs. 6%, p<0.0001). A similar pattern was observed for 2,4-D and acetochlor (92% vs. 47%, p<0.0001 and 45% vs. 4%, p<0.0001, respectively). Conclusion Urinary AZM levels in farmers were largely driven by recent application of atrazine. Therefore, the amount of atrazine applied is likely to provide valid surrogates of atrazine exposure in epidemiologic studies. Elevated background levels of non-persistent pesticides, especially 2,4-D, indicate importance in epidemiologic studies of capturing pesticide exposures that might not be directly related to the actual application. PMID:19052531

  10. Impacts of genetic line, gender and season on feeding behavior of grow-finish swine

    Science.gov (United States)

    Feeding behavior contains important information that can enable producers to better manage livestock. A study was conducted to quantify these impacts. Data were collected on barrows and gilts (n = 931) from 3 different genetic lines (Landrace x Yorkshire material line with three different sire bree...

  11. Physiological and morphological responses of olive plants to ozone exposure during a growing season

    Energy Technology Data Exchange (ETDEWEB)

    Minnocci, A.; Panicucci, A.; Sebastiani, L.; Lorenzini, G.; Vitagliano, C.

    1999-05-01

    Physiological and morphological responses in leaves of two varieties (Frantoio and Moraiolo) of five-year old olive plants were measured following exposure in filtered air to three ppb or 100 ppb of ozone, five hours per day, for 120 days in fumigation chambers. Significant reduction in photosynthetic activity and stomatal conductance were detected in ozone-fumigated plants of Frantoio leaves compared with control plants. In Moraiolo leaves, the differences were not statistically significant but there was a significant reduction in stomatal conductance. In both cultivars, there was evidence of decrease in stomatal aperture and stomatal surface after ozone exposure, and increased stomatal density compared with control leaves. Since stomata play a crucial role in controlling water use in olive tree leaves, the large ozone-induced reduction in transpiring stomatal surface could have serious consequences for olive productivity in the Mediterranean area where high ozone concentration is common for long periods during the year. 37 refs., 3 tabs., 3 figs.

  12. Changes in quality of selected red beet (Beta vulgaris L. cultivars during the growing season

    Directory of Open Access Journals (Sweden)

    Nizioł-Łukaszewska Zofia

    2014-12-01

    Full Text Available Red beet (Beta vulgaris L. may be consumed at all stages of growth, both in the form of small early vegetable during spring and later, during winter, when stored. Therefore, knowledge of the dynamics of changes in the content of individual components in subsequent stages of growth is very important.

  13. Global response of the growing season to soil moisture and topography

    Science.gov (United States)

    Guevara, M.; Arroyo, C.; Warner, D. L.; Equihua, J.; Lule, A. V.; Schwartz, A.; Taufer, M.; Vargas, R.

    2017-12-01

    Soil moisture has a direct influence in plant productivity. Plant productivity and its greenness can be inferred by remote sensing with higher spatial detail than soil moisture. The objective was to improve the coarse scale of currently available satellite soil moisture estimates and identify areas of strong coupling between the interannual variability soil moisture and the maximum greenness vegetation fraction (MGVF) at the global scale. We modeled, cross-validated and downscaled remotely sensed soil moisture using machine learning and digital terrain analysis across 23 years (1991-2013) of available data. Improving the accuracy (0.69-0.87 % of cross-validated explained variance) and the spatial detail (from 27 to 15km) of satellite soil moisture, we filled temporal gaps of information across vegetated areas where satellite soil moisture does not work properly. We found that 7.57% of global vegetated area shows strong correlation with our downscaled product (R2>0.5, Fig. 1). We found a dominant positive response of vegetation greenness to topography-based soil moisture across water limited environments, however, the tropics and temperate environments of higher latitudes showed a sparse negative response. We conclude that topography can be used to effectively improve the spatial detail of globally available remotely sensed soil moisture, which is convenient to generate unbiased comparisons with global vegetation dynamics, and better inform land and crop modeling efforts.

  14. Winter climate change affects growing-season soil microbial biomass and activity in northern hardwood forests

    Science.gov (United States)

    Jorge Durán; Jennifer L. Morse; Peter M. Groffman; John L. Campbell; Lynn M. Christenson; Charles T. Driscoll; Timothy J. Fahey; Melany C. Fisk; Myron J. Mitchell; Pamela H. Templer

    2014-01-01

    Understanding the responses of terrestrial ecosystems to global change remains a major challenge of ecological research. We exploited a natural elevation gradient in a northern hardwood forest to determine how reductions in snow accumulation, expected with climate change, directly affect dynamics of soil winter frost, and indirectly soil microbial biomass and activity...

  15. Quantifying livestock effects on bunchgrass vegetation with Landsat ETM+ data across a single growing season

    Science.gov (United States)

    Working grassland systems provide important habitat for native biodiversity and forage for livestock, with proper livestock grazing playing an important role for sustainable ecosystem function. Traditional in-field techniques to monitor the effects of grazing on vegetation are costly and limited to ...

  16. Seasonal and scale-dependent variability in nutrient- and allelopathy-mediated macrophyte–phytoplankton interactions

    Directory of Open Access Journals (Sweden)

    Lombardo P.

    2013-08-01

    Full Text Available macrophyte–phytoplankton interactions were investigated using a dual laboratory and field approach during a growing season, with responses quantified as changes in biomass. Short-term, close-range interactions in laboratory microcosms always led to mutual exclusion of macrophytes (Elodea canadensis or Ceratophyllum demersum and algae (Raphidocelis subcapitata, Fistulifera pelliculosa or cyanobacteria (Synechococcus leopoliensis, suggesting regulation by positive feedback mechanisms, progressively establishing and reinforcing a “stable state”. Laboratory results suggest that close-range regulation of R. subcapitata and F. pelliculosa by macrophytes was primarily via nutrient (N, P mediation. Sprig-produced allelochemicals may have contributed to inhibition of S. leopoliensis in C. demersum presence, while S. leopoliensis was apparently enhanced by nutrients leaked by subhealthy (discolored leaves; biomass loss E. canadensis. Seasonal changes in algal growth suppression were correlated with sprig growth. Marginal differences in in situ phytoplankton patterns inside and outside monospecific macrophyte stands suggest that the nutrient- and/or allelopathy-mediated close-range mechanisms observed in the laboratory did not propagate at the macrophyte-stand scale. Factors operating at a larger scale (e.g., lake trophic state, extent of submerged vegetation coverage appear to override in situ macrophyte–phytoplankton close-range interactions.

  17. Vaccination against seasonal influenza

    CERN Multimedia

    DG Unit

    2009-01-01

    As every year, the Medical Service is taking part in the campaign to promote vaccination against seasonal influenza. Vaccination against seasonal influenza is especially recommended for people suffering from chronic lung, cardio-vascular or kidney conditions or diabetes, for those recovering from a serious illness or surgical operation and for everyone over the age of 65. The influenza virus is transmitted by air and contact with contaminated surfaces, hence the importance of washing hands regularly with soap and / or disinfection using a hydro-alcoholic solution. From the onset of symptoms (fever> 38°, chills, cough, muscle aches and / or joint pain, fatigue) you are strongly recommended to stay at home to avoid spreading the virus. In the present context of the influenza A (H1N1) pandemic, it is important to dissociate these two illnesses and emphasise that the two viruses and the vaccines used to combat them are quite different and that protection against one will not pr...

  18. Vaccination against seasonal flu

    CERN Multimedia

    2015-01-01

    The Medical Service once again recommends you to get your annual flu vaccination for the year.   Vaccination is the most effective way of avoiding the illness and any serious consequences and protecting those around you. The flu can have especially serious consequences for people with chronic conditions (diabetes, cardio-vascular disease, etc.), pregnant women, infants, and people over 65 years of age. Remember, anyone working on the CERN site who wishes to be vaccinated against seasonal flu should go to the Infirmary (Building 57, ground floor) with their vaccine. The Medical Service will issue a prescription on the day of the vaccination for the purposes of reimbursement by UNIQA. NB: The Medical Service cannot provide this vaccination service for family members or retired members of the personnel. For more information: • The "Seasonal flu" flyer by the Medical Service • Recommendations of the Swiss Federal Office of Public...

  19. Summer season | Cafeteria closures

    CERN Multimedia

    2013-01-01

    Please note the following cafeteria closures over the summer season: Bldg. 54 closed from 29/07/2013 to 06/09/2013. Bldg. 13: closed from 13/07/2013 to 06/09/2013. Restaurant No. 2, table service (brasserie and restaurant): closed from 01/08/2013 to 06/09/2013. Bldg. 864: closed from 29/07/2013 to 06/09/2013. Bldg. 865: closed from 29/07/2013 to 06/09/2013.

  20. Vaccination against seasonal influenza

    CERN Document Server

    GS Department

    2010-01-01

    This year, as usual, the Medical Service is helping to promote vaccination against seasonal influenza. Vaccination against seasonal flu is especially recommended for anyone who suffers from chronic pulmonary, cardio-vascular or kidney disease or diabetes, is recovering from a serious illness or major surgery, or is over 65 years of age. The flu virus is transmitted through the air and through contact with contaminated surfaces, so frequent hand-washing with soap and/or an antiseptic hand wash is of great importance. As soon as the first symptoms appear (fever above 38°, shivering, coughing, muscle and/or joint pains, generalised weakness), you are strongly recommended to stay at home to avoid spreading the virus. Anyone working on the CERN site who wishes to be vaccinated against seasonal flu should go to the Infirmary (Building 57, ground floor), with their dose of vaccine. The Medical Service will issue a prescription on the day of the vaccination for the purposes of reimbursement through UNIQA...

  1. Direct contamination - seasonality

    International Nuclear Information System (INIS)

    Aarkrog, A.

    1994-01-01

    Direct contamination is the primary pathway to terrestrial vegetation in the first period after an activity release to the atmosphere. All radionuclides are able to be transferred via this pathway. Deposition, interception and retention are the three processes involved in direct contamination of crops. Wet deposition is more important than dry deposition in temperature regions. Resuspension and rainsplash both belong to secondary direct deposition and became evident for e.g. radiocaesium after the Chernobyl accident. Seasonality is the varying response to radioactive contamination of crops according to the time of the year when the contamination occurs. Shortlived radionuclides (as 131 I) and those that mainly enter the foodchain by direct contamination (e.g. 137 Cs) are especially important in this connection. In particular, the contamination of cereal crops is influenced by seasonality. As a result of seasonality the impact of the Chernobyl accident on the radioactive contamination of human diet was for the same deposition density higher in southern than in northern Europe. (orig.)

  2. 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.

  3. Seasonal evolution of carbon allocation to biomass in a French beech forest.

    Science.gov (United States)

    Heid, Laura; Calvaruso, Christophe; Conil, Sébastien; Turpault, Marie-Pierre; Longdoz, Bernard

    2015-04-01

    The objective of this study is to get a better understanding of ecosystem behavior in term of assimilated carbon (C) use. In the global climate change context, this C allocation could play a critical role in predicting ecosystems long terms emissions (Trumbore 2006) and has become a major goal of several emergent studies The monthly C allocation has been determined for a 50-year old beech forest located in north-east of France through the quantification of Gross Primary Production (GPP), biomass production and some of its components (holocelluloses, lignin). In a second phase, the potential factors influencing those productions and allocations throughout a year have been assessed. The temporal evolution of GPP was obtained from the partitioning of eddy-covariance flux measurements and monitored for one year. It was connected to tree aboveground C biomass growth at a monthly step. To achieve the latter, site specific allometric equations were used with trees diameter at breast height (DBH) measured monthly during the growing season on one hand and, on the other hand, C concentrations were deduced from analyses on trunk cores (sampled monthly) and on leaves and bulk branches cores (sampled at the beginning and at the end of the growing season). The C allocated to the aboveground biomass was then estimated, along with the portion allocated to structural C. The results show the delay existing between the end of the tree growth and carbon assimilation. We analyze the possibility to explain this divergence by a compensation coming from the C concentration evolution. Keywords: Carbon allocation, Forest, Biomass production, Carbon concentration, Eddy Covariance Trumbore S. 2006. Carbon Respired by Terrestrial Ecosystems - Recent Progress and Challenges. Global Change Biology 12 (2): 141-53.

  4. Seasonal variation in the diet of spoonbill chicks in the Wadden Sea : A stable isotopes approach

    NARCIS (Netherlands)

    El-Hacen, El-Hacen Mohamed; Piersma, Theunis; Jouta, Jeltje; Overdijk, Otto; Lok, Tamar

    We used stable isotope tracers in the growing primary feathers of Eurasian Spoonbill chicks (Platalea leucorodia leucorodia) to study seasonal variation in their diet on one of the Frisian islands, Schiermonnikoog, The Netherlands. Using growing individual primaries as natural samplers over time,

  5. Seasonal and annual dietary changes in Lesser Kestrels Falco ...

    African Journals Online (AJOL)

    The proportion of pellets containing scarabaeid and carabid beetles, as well as those containing locusts and crickets, increased as the wintering season progressed, while the proportion of pellets containing solifugids decreased during the same period. Significant differences in diet composition were recorded between the ...

  6. Response of growing bones to irradiation

    International Nuclear Information System (INIS)

    Gonzalez Gonzalez, D.

    1980-01-01

    This thesis describes the effects of ionizing radiations on growing bones. The epiphyseal disc of growing mouse tibia was selected as a model for the experiments. An attempt has been made to obtain clinical data from irradiated bones during the childhood and to quantitate this information. Within the range of possibilities correlations have been established between the experimental and clinical data. (Auth.)

  7. Geometric Growing Patterns: What's the Rule?

    Science.gov (United States)

    Hourigan, Mairéad; Leavy, Aisling

    2015-01-01

    While within a geometric repeating pattern, there is an identifiable core which is made up of objects that repeat in a predictable manner, a geometric growing pattern (also called visual or pictorial growing patterns in other curricula) "is a pattern that is made from a sequence of figures [or objects] that change from one term to the next in…

  8. Seasonal variation in diurnal atmospheric grass pollen concentration profiles

    DEFF Research Database (Denmark)

    Peel, Robert George; Orby, P.V.; Skjoth, C. A.

    2014-01-01

    In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish...... the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods...... of the pollen season. Pollen concentrations are also influenced by meteorological factors - directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season...

  9. Species diversity of dry season avian fauna in Kano, Nigeria | Ishaq ...

    African Journals Online (AJOL)

    The avian fauna in Nigeria and the rest of West Africa is fairly rich, especially during the rainy season when most of the birds are breeding. However, the frequency of species encounter in the field changes as the dry season progresses. The present study examined the diversity of birds during the three dry months following ...

  10. Vaccination against seasonal influenza

    CERN Multimedia

    SC Unit

    2009-01-01

    As every year, the Medical Service is taking part in the campaign to promote vaccination against seasonal influenza. Vaccination against seasonal influenza is especially recommended for people suffering from chronic lung, cardio-vascular or kidney conditions or diabetes, for those recovering from a serious illness or surgical operation and for everyone over the age of 65. The influenza virus is transmitted by air and contact with contaminated surfaces, hence the importance of washing hands regularly with soap and / or disinfection using a hydro-alcoholic solution. From the onset of symptoms (fever> 38°, chills, cough, muscle aches and / or joint pain, fatigue) you are strongly recommended to stay at home to avoid spreading the virus. In the present context of the influenza A (H1N1) pandemic, it is important to dissociate these two illnesses and emphasise that the two viruses and the vaccines used to combat them are quite different and that protection against one will not provide protection against the...

  11. Music season coming soon

    CERN Multimedia

    CERN Bulletin in collaboration with Julio Rosenfeld

    2012-01-01

    On 16 June, CERN’s music season will open with Music on the Lawn. The event is the CERN Music Club’s contribution to the Fete de la Musique and will take place on the terrace of Restaurant 1 from 2 p.m. to 8 p.m. The Hardronic Festival, CERN’s long-running rock festival, will be held on the evenings of 20 and 21 July in Prévessin, on the terrace behind Restaurant 3. If you would like to help with the organisation, please contact the Music Club by e-mail: music.club@cern.ch.   The Canettes Blues Band during the 2011 Hardronic Festival. (© Christoph Balle, 2010). Summer is coming, and along with it comes the music season. CERN will be hosting its two annual rock music concerts: Music on the Lawn and the Hardronic Festival. The two events are organised by the CERN Music Club, which has been sharing the enjoyment of good music with its numerous fans for many years. “Music on the Lawn was originally created so that the members of the Mus...

  12. Flu season and trehalose

    Directory of Open Access Journals (Sweden)

    Robbins RA

    2018-01-01

    Full Text Available Most of us who are practicing medicine know that we are in a very active flu season. This was brought home to me when last week trying to admit a patient to the hospital from the office. She was a bone marrow transplant patient who had severe diarrhea and dehydration probably secondary to C. difficile. Hospital admissions said the patient had to be sent to the Emergency Room because the hospital was full due to the flu epidemic. Nationwide there has been a dramatic increase in the number of hospitalizations due to influenza over the past week from 13.7 to 22.7 per 100,000 (1. Influenza A(H3N2 has been the most common form of influenza reported this season. These viruses are often linked to more severe illness, especially in children and people age 65 years and older. Fortunately, the CDC also says that the flu cases may be peaking. However, at ...

  13. Disrupted seasonal biology impacts health, food security and ecosystems

    Science.gov (United States)

    Stevenson, T. J.; Visser, M. E.; Arnold, W.; Barrett, P.; Biello, S.; Dawson, A.; Denlinger, D. L.; Dominoni, D.; Ebling, F. J.; Elton, S.; Evans, N.; Ferguson, H. M.; Foster, R. G.; Hau, M.; Haydon, D. T.; Hazlerigg, D. G.; Heideman, P.; Hopcraft, J. G. C.; Jonsson, N. N.; Kronfeld-Schor, N.; Kumar, V.; Lincoln, G. A.; MacLeod, R.; Martin, S. A. M.; Martinez-Bakker, M.; Nelson, R. J.; Reed, T.; Robinson, J. E.; Rock, D.; Schwartz, W. J.; Steffan-Dewenter, I.; Tauber, E.; Thackeray, S. J.; Umstatter, C.; Yoshimura, T.; Helm, B.

    2015-01-01

    The rhythm of life on earth is shaped by seasonal changes in the environment. Plants and animals show profound annual cycles in physiology, health, morphology, behaviour and demography in response to environmental cues. Seasonal biology impacts ecosystems and agriculture, with consequences for humans and biodiversity. Human populations show robust annual rhythms in health and well-being, and the birth month can have lasting effects that persist throughout life. This review emphasizes the need for a better understanding of seasonal biology against the backdrop of its rapidly progressing disruption through climate change, human lifestyles and other anthropogenic impact. Climate change is modifying annual rhythms to which numerous organisms have adapted, with potential consequences for industries relating to health, ecosystems and food security. Disconcertingly, human lifestyles under artificial conditions of eternal summer provide the most extreme example for disconnect from natural seasons, making humans vulnerable to increased morbidity and mortality. In this review, we introduce scenarios of seasonal disruption, highlight key aspects of seasonal biology and summarize from biomedical, anthropological, veterinary, agricultural and environmental perspectives the recent evidence for seasonal desynchronization between environmental factors and internal rhythms. Because annual rhythms are pervasive across biological systems, they provide a common framework for trans-disciplinary research. PMID:26468242

  14. State of the Science for Sub-Seasonal to Seasonal Precipitation Forecasting in Support of Water Resource Managers

    Science.gov (United States)

    DeWitt, D. G.

    2017-12-01

    Water resource managers are one of the communities that would strongly benefit from highly-skilled sub-seasonal to seasonal precipitation forecasts. Unfortunately, the current state of the art prediction tools frequently fail to provide a level of skill sufficient to meet the stakeholders needs, especially on the monthly and seasonal timescale. On the other hand, the skill of precipitation forecasts on the week-2 timescale are relatively high and arguably useful in many decision-making contexts. This talk will present a comparison of forecast skill for the week-2 through the first season timescale and describe current efforts within NOAA and elsewhere to try to improve forecast skill beyond week-2, including research gaps that need to be addressed in order to make progress.

  15. Seasonal slope surface deformation measured with TLS

    International Nuclear Information System (INIS)

    Fan, L; Smethurst, J; Powrie, W; Sellaiya, A

    2014-01-01

    In temperate European climates, soil water removal due to vegetation transpiration peaks in summer and soil rewetting from higher levels of precipitation occurs in winter. In clays of high plasticity, the seasonal cycles of drying and wetting cause the soil to experience a volumetric change, resulting in seasonal shrinking and swelling. For a clay slope exhibiting volume change, such behaviour can lead to excessive deformation and could contribute to strain-softening and progressive slope failure. This can in turn cause traffic disruption and loss of life if roads and railways are founded on or surrounded by such slopes. This paper discusses the driving forces of seasonal surface movement, in particular the role of vegetation, and presents the use of Terrestrial Laser Scanning (TLS) to measure the surface movement of a lightly vegetated London Clay slope near Newbury, UK. Two TLS scans were carried out in early and late summer respectively, representing relative wet and dry conditions of the slope. Continuous field measurements of soil water content in upper layers of the slope were obtained from TDR ThetaProbes already installed at the site. The water content data are used to support the results obtained from TLS by indicating the likely volumetric change in the soil due to loss of water

  16. Impacts of Land Cover and Seasonal Variation on Maximum Air Temperature Estimation Using MODIS Imagery

    Directory of Open Access Journals (Sweden)

    Yulin Cai

    2017-03-01

    Full Text Available Daily maximum surface air temperature (Tamax is a crucial factor for understanding complex land surface processes under rapid climate change. Remote detection of Tamax has widely relied on the empirical relationship between air temperature and land surface temperature (LST, a product derived from remote sensing. However, little is known about how such a relationship is affected by the high heterogeneity in landscapes and dynamics in seasonality. This study aims to advance our understanding of the roles of land cover and seasonal variation in the estimation of Tamax using the MODIS (Moderate Resolution Imaging Spectroradiometer LST product. We developed statistical models to link Tamax and LST in the middle and lower reaches of the Yangtze River in China for five major land-cover types (i.e., forest, shrub, water, impervious surface, cropland, and grassland and two seasons (i.e., growing season and non-growing season. Results show that the performance of modeling the Tamax-LST relationship was highly dependent on land cover and seasonal variation. Estimating Tamax over grasslands and water bodies achieved superior performance; while uncertainties were high over forested lands that contained extensive heterogeneity in species types, plant structure, and topography. We further found that all the land-cover specific models developed for the plant non-growing season outperformed the corresponding models developed for the growing season. Discrepancies in model performance mainly occurred in the vegetated areas (forest, cropland, and shrub, suggesting an important role of plant phenology in defining the statistical relationship between Tamax and LST. For impervious surfaces, the challenge of capturing the high spatial heterogeneity in urban settings using the low-resolution MODIS data made Tamax estimation a difficult task, which was especially true in the growing season.

  17. Microsatellite Primers for Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen Fredsted, Palle; Gertsch, Pia J.; Boomsma, Jacobus Jan (Koos)

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  18. Microsatellite primers for fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Gertsch, P J; Boomsma, JJ

    2002-01-01

    We isolated five polymorphic microsatellite loci from a library of two thousand recombinant clones of two fungus-growing ant species, Cyphomyrmex longiscapus and Trachymyrmex cf. zeteki. Amplification and heterozygosity were tested in five species of higher attine ants using both the newly...... developed primers and earlier published primers that were developed for fungus-growing ants. A total of 20 variable microsatellite loci, developed for six different species of fungus-growing ants, are now available for studying the population genetics and colony kin-structure of these ants....

  19. The study of seasonal dynamics of plankton trajectories using the duble-smoothing method

    Directory of Open Access Journals (Sweden)

    Syarki Maria

    2013-03-01

    Full Text Available To study the seasonal processes in zooplankton of Lake Onega and to determine the changes in the trajectory its values ​​were analyzed by the method of double smoothing. A series of smooth curves describes the trajectories of the changes of the number and biomass of zooplankton and its major groups during the growing season (May to October. They reflect the basic laws of community dynamics, the shape of the trajectories of seasonal dynamics, phenology, or the dates of important events, the periods and the increasing and decreasing rate of plankter amount, the seasonal changes in the community structure.

  20. Cold season emissions dominate the Arctic tundra methane budget.

    Science.gov (United States)

    Zona, Donatella; Gioli, Beniamino; Commane, Róisín; Lindaas, Jakob; Wofsy, Steven C; Miller, Charles E; Dinardo, Steven J; Dengel, Sigrid; Sweeney, Colm; Karion, Anna; Chang, Rachel Y-W; Henderson, John M; Murphy, Patrick C; Goodrich, Jordan P; Moreaux, Virginie; Liljedahl, Anna; Watts, Jennifer D; Kimball, John S; Lipson, David A; Oechel, Walter C

    2016-01-05

    Arctic terrestrial ecosystems are major global sources of methane (CH4); hence, it is important to understand the seasonal and climatic controls on CH4 emissions from these systems. Here, we report year-round CH4 emissions from Alaskan Arctic tundra eddy flux sites and regional fluxes derived from aircraft data. We find that emissions during the cold season (September to May) account for ≥ 50% of the annual CH4 flux, with the highest emissions from noninundated upland tundra. A major fraction of cold season emissions occur during the "zero curtain" period, when subsurface soil temperatures are poised near 0 °C. The zero curtain may persist longer than the growing season, and CH4 emissions are enhanced when the duration is extended by a deep thawed layer as can occur with thick snow cover. Regional scale fluxes of CH4 derived from aircraft data demonstrate the large spatial extent of late season CH4 emissions. Scaled to the circumpolar Arctic, cold season fluxes from tundra total 12 ± 5 (95% confidence interval) Tg CH4 y(-1), ∼ 25% of global emissions from extratropical wetlands, or ∼ 6% of total global wetland methane emissions. The dominance of late-season emissions, sensitivity to soil environmental conditions, and importance of dry tundra are not currently simulated in most global climate models. Because Arctic warming disproportionally impacts the cold season, our results suggest that higher cold-season CH4 emissions will result from observed and predicted increases in snow thickness, active layer depth, and soil temperature, representing important positive feedbacks on climate warming.

  1. Cold season emissions dominate the Arctic tundra methane budget

    Science.gov (United States)

    Zona, Donatella; Gioli, Beniamino; Commane, Róisín; Lindaas, Jakob; Wofsy, Steven C.; Miller, Charles E.; Dinardo, Steven J.; Dengel, Sigrid; Sweeney, Colm; Karion, Anna; Chang, Rachel Y.-W.; Henderson, John M.; Murphy, Patrick C.; Goodrich, Jordan P.; Moreaux, Virginie; Liljedahl, Anna; Watts, Jennifer D.; Kimball, John S.; Lipson, David A.; Oechel, Walter C.

    2016-01-01

    Arctic terrestrial ecosystems are major global sources of methane (CH4); hence, it is important to understand the seasonal and climatic controls on CH4 emissions from these systems. Here, we report year-round CH4 emissions from Alaskan Arctic tundra eddy flux sites and regional fluxes derived from aircraft data. We find that emissions during the cold season (September to May) account for ≥50% of the annual CH4 flux, with the highest emissions from noninundated upland tundra. A major fraction of cold season emissions occur during the "zero curtain" period, when subsurface soil temperatures are poised near 0 °C. The zero curtain may persist longer than the growing season, and CH4 emissions are enhanced when the duration is extended by a deep thawed layer as can occur with thick snow cover. Regional scale fluxes of CH4 derived from aircraft data demonstrate the large spatial extent of late season CH4 emissions. Scaled to the circumpolar Arctic, cold season fluxes from tundra total 12 ± 5 (95% confidence interval) Tg CH4 y-1, ∼25% of global emissions from extratropical wetlands, or ∼6% of total global wetland methane emissions. The dominance of late-season emissions, sensitivity to soil environmental conditions, and importance of dry tundra are not currently simulated in most global climate models. Because Arctic warming disproportionally impacts the cold season, our results suggest that higher cold-season CH4 emissions will result from observed and predicted increases in snow thickness, active layer depth, and soil temperature, representing important positive feedbacks on climate warming.

  2. BLOOD METABOLIC HORMONES AND LEPTIN IN GROWING LAMBS

    Directory of Open Access Journals (Sweden)

    Zvonko Antunović

    2010-12-01

    Full Text Available The aim of this paper is to determine the concentration of blood metabolic hormones and leptin levels in growing lambs. The research was carried out on Tsigai lambs in two periods (suckling and fattening during the winter feeding season. Lambs were suckling and ate a food mixture and alfalfa hay ad libitum, while during the fattening period they were fed only with the above mentioned mixture and alfalfa hay ad libitum. Their blood was analyzed on 35th and 75th day of age. Concentrations of minsulin, leptin and thyroid hormones were determined in the blood serum of lambs during both periods. In the blood of fattening lambs significantly higher (P0.05 insulin concentrations (1.05 and 0.54 μU/mL, were determined, compared to suckling lambs. A significant strong positive correlation between serum leptin and insulin (r = 0.85, P0.05. The concentration of thyroid hormones did not significantly differ depending on the period of measurement. These changes indicate that the measurement concentrations of metabolic hormones and leptin in blood are very important in order to understand the changes of metabolism and nutrient supply in growing lambs.

  3. 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.

  4. Growing Languages with Metamorphic Syntax Macros

    DEFF Research Database (Denmark)

    Brabrand, Claus; Schwartzbach, Michael Ignatieff

    2002-01-01

    "From now on, a main goal in designing a language should be to plan for growth." Guy Steele: Growing a Language, OOPSLA '98 invited talk.We present our experiences with a syntax macro language which we claim forms a general abstraction mechanism for growing (domain-specific) extensions of program......"From now on, a main goal in designing a language should be to plan for growth." Guy Steele: Growing a Language, OOPSLA '98 invited talk.We present our experiences with a syntax macro language which we claim forms a general abstraction mechanism for growing (domain-specific) extensions...... of programming languages. Our syntax macro language is designed to guarantee type safety and termination.A concept of metamorphisms allows the arguments of a macro to be inductively defined in a meta level grammar and morphed into the host language. We also show how the metamorphisms can be made to operate...

  5. Growing America's Energy Future

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-06-01

    The emerging U.S. bioenergy industry provides a secure and growing supply of transportation fuels, biopower, and bioproducts produced from a range of abundant, renewable biomass resources. Bioenergy can help ensure a secure, sustainable, and economically sound future by reducing U.S. dependence on foreign oil, developing domestic clean energy sources, and generating domestic green jobs. Bioenergy can also help address growing concerns about climate change by reducing greenhouse gas emissions to create a healthier environment for current and future generations.

  6. Vegetation response to rainfall seasonality and interannual variability in tropical dry forests

    Science.gov (United States)

    Feng, X.; Silva Souza, R. M.; Souza, E.; Antonino, A.; Montenegro, S.; Porporato, A. M.

    2015-12-01

    We analyzed the response of tropical dry forests to seasonal and interannual rainfall variability, focusing on the caatinga biome in semi-arid in Northeast Brazil. We selected four sites across a gradient of rainfall amount and seasonality and analyzed daily rainfall and biweekly Normalized Difference Vegetation Index (NDVI) in the period 2000-2014. The seasonal and interannual rainfall statistics were characterized using recently developed metrics describing duration, location, and intensity of wet season and compared them with those of NDVI time series and modelled soil moisture. A model of NDVI was also developed and forced by different rainfall scenarios (combination amount of rainfall and duration of wet season). The results show that the caatinga tends to have a more stable response characterized by longer and less variable growing seasons (of duration 3.1±0.1 months) compared to the rainfall wet seasons (2.0±0.5 months). Even for more extreme rainfall conditions, the ecosystem shows very little sensitivity to duration of wet season in relation to the amount of rainfall, however the duration of wet season is most evident for wetter sites. This ability of the ecosystem in buffering the interannual variability of rainfall is corroborated by the stability of the centroid location of the growing season compared to the wet season for all sites. The maximal biomass production was observed at intermediate levels of seasonality, suggesting a possible interesting trade-off in the effects of intensity (i.e., amount) and duration of the wet season on vegetation growth.

  7. Successional dynamics in the seasonally forced diamond food web.

    Science.gov (United States)

    Klausmeier, Christopher A; Litchman, Elena

    2012-07-01

    Plankton seasonal succession is a classic example of nonequilibrium community dynamics. Despite the fact that it has been well studied empirically, it lacks a general quantitative theory. Here we investigate a food web model that includes a resource, two phytoplankton, and a shared grazer-the diamond food web-in a seasonal environment. The model produces a number of successional trajectories that have been widely discussed in the context of the verbal Plankton Ecology Group model of succession, such as a spring bloom of a good competitor followed by a grazer-induced clear-water phase, setting the stage for the late-season dominance of a grazer-resistant species. It also predicts a novel, counterintuitive trajectory where the grazer-resistant species has both early- and late-season blooms. The model often generates regular annual cycles but sometimes produces multiyear cycles or chaos, even with identical forcing each year. Parameterizing the model, we show how the successional trajectory depends on nutrient supply and the length of the growing season, two key parameters that vary among water bodies. This model extends nonequilibrium theory to food webs and is a first step toward a quantitative theory of plankton seasonal succession.

  8. Forecasting infectious disease emergence subject to seasonal forcing.

    Science.gov (United States)

    Miller, Paige B; O'Dea, Eamon B; Rohani, Pejman; Drake, John M

    2017-09-06

    Despite high vaccination coverage, many childhood infections pose a growing threat to human populations. Accurate disease forecasting would be of tremendous value to public health. Forecasting disease emergence using early warning signals (EWS) is possible in non-seasonal models of infectious diseases. Here, we assessed whether EWS also anticipate disease emergence in seasonal models. We simulated the dynamics of an immunizing infectious pathogen approaching the tipping point to disease endemicity. To explore the effect of seasonality on the reliability of early warning statistics, we varied the amplitude of fluctuations around the average transmission. We proposed and analyzed two new early warning signals based on the wavelet spectrum. We measured the reliability of the early warning signals depending on the strength of their trend preceding the tipping point and then calculated the Area Under the Curve (AUC) statistic. Early warning signals were reliable when disease transmission was subject to seasonal forcing. Wavelet-based early warning signals were as reliable as other conventional early warning signals. We found that removing seasonal trends, prior to analysis, did not improve early warning statistics uniformly. Early warning signals anticipate the onset of critical transitions for infectious diseases which are subject to seasonal forcing. Wavelet-based early warning statistics can also be used to forecast infectious disease.

  9. Arithmetic Progressions on Conics

    OpenAIRE

    Ciss, Abdoul Aziz; Moody, Dustin

    2016-01-01

    In this paper, we look at long arithmetic progressions on conics. By an arithmetic progression on a curve, we mean the existence of rational points on the curve whose x-coordinates are in arithmetic progression. We revisit arithmetic progressions on the unit circle, constructing 3-term progressions of points in the first quadrant containing an arbitrary rational point on the unit circle. We also provide infinite families of three term progressions on the unit hyperbola, as well as conics ax2 ...

  10. Progress in neuromorphic photonics

    Science.gov (United States)

    Ferreira de Lima, Thomas; Shastri, Bhavin J.; Tait, Alexander N.; Nahmias, Mitchell A.; Prucnal, Paul R.

    2017-03-01

    As society's appetite for information continues to grow, so does our need to process this information with increasing speed and versatility. Many believe that the one-size-fits-all solution of digital electronics is becoming a limiting factor in certain areas such as data links, cognitive radio, and ultrafast control. Analog photonic devices have found relatively simple signal processing niches where electronics can no longer provide sufficient speed and reconfigurability. Recently, the landscape for commercially manufacturable photonic chips has been changing rapidly and now promises to achieve economies of scale previously enjoyed solely by microelectronics. By bridging the mathematical prowess of artificial neural networks to the underlying physics of optoelectronic devices, neuromorphic photonics could breach new domains of information processing demanding significant complexity, low cost, and unmatched speed. In this article, we review the progress in neuromorphic photonics, focusing on photonic integrated devices. The challenges and design rules for optoelectronic instantiation of artificial neurons are presented. The proposed photonic architecture revolves around the processing network node composed of two parts: a nonlinear element and a network interface. We then survey excitable lasers in the recent literature as candidates for the nonlinear node and microring-resonator weight banks as the network interface. Finally, we compare metrics between neuromorphic electronics and neuromorphic photonics and discuss potential applications.

  11. Global Seasonality of Rotavirus Disease

    Science.gov (United States)

    Patel, Manish M.; Pitzer, Virginia; Alonso, Wladimir J.; Vera, David; Lopman, Ben; Tate, Jacqueline; Viboud, Cecile; Parashar, Umesh D.

    2012-01-01

    Background A substantial number of surveillance studies have documented rotavirus prevalence among children admitted for dehydrating diarrhea. We sought to establish global seasonal patterns of rotavirus disease before widespread vaccine introduction. Methods We reviewed studies of rotavirus detection in children with diarrhea published since 1995. We assessed potential relationships between seasonal prevalence and locality by plotting the average monthly proportion of diarrhea cases positive for rotavirus according to geography, country development, and latitude. We used linear regression to identify variables that were potentially associated with the seasonal intensity of rotavirus. Results Among a total of 99 studies representing all six geographical regions of the world, patterns of year-round disease were more evident in low- and low-middle income countries compared with upper-middle and high income countries where disease was more likely to be seasonal. The level of country development was a stronger predictor of strength of seasonality (P=0.001) than geographical location or climate. However, the observation of distinctly different seasonal patterns of rotavirus disease in some countries with similar geographical location, climate and level of development indicate that a single unifying explanation for variation in seasonality of rotavirus disease is unlikely. Conclusion While no unifying explanation emerged for varying rotavirus seasonality globally, the country income level was somewhat more predictive of the likelihood of having seasonal disease than other factors. Future evaluation of the effect of rotavirus vaccination on seasonal patterns of disease in different settings may help understand factors that drive the global seasonality of rotavirus disease. PMID:23190782

  12. The effects of genotype and growing conditions on antioxidant capacity, phenolic compounds, organic acid and individual sugars of strawberry.

    Science.gov (United States)

    Gündüz, Kazim; Ozdemir, Emine

    2014-07-15

    In this study, the genotypic and environmental effects for bioactive compounds in strawberries were partitioned. 13 strawberry genotypes from diverse breeding programs were selected. The genotypes were grown in three growing conditions: greenhouse (GH), plastic tunnel (PT) and open-field (OF) for two growing seasons. The results indicated that the genotypes were significantly different for most of the characteristics tested except the ferric reducing ability assay (FRAP) and Trolox-equivalent antioxidant capacity assay (TEAC) in the second growing season, while the growing conditions were only significant for total phenolic content (TPC) and fructose and total sugar content in the first growing season. Genotype had 71% and 72% of the total variance for total monomeric anthocyanin contents (TMA), while it had only 12% and 13% of the variance for TPC in the first and second year of the experiment. Genotype effect was larger than that from the growing conditions for most of the bioactive component variables in the experiment indicated that breeding for bioactive components may be successful. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Growing apple (Malus domestica) under tropical mountain climate conditions in Northern Ethiopia

    OpenAIRE

    Ashebir, Dereje; Deckers, Tom; Nyssen, Jan; Bihon, Wubetu; Tsegay, Alemtsehay; Tekie, Hailemariam; Poesen, Jean; Haile, Mitiku; Wondumagegnehe, Fekadu; Raes, Dirk; Behailu, Mintesinot; Deckers, Jozef

    2010-01-01

    Lack of effective chilling during the dormant season is one of the major problems when apples are growing under a tropical climate. We evaluated the response of different apple cultivars (Golden Delicious, Gala, Fuji, Granny Smith and Jonagold) grown on M9 rootstock with different dormancy-management practices. The trials were carried out between 2004 and 2006 in a tropical mountain area (Tigray, Ethiopia), where chilling conditions are poor with the aim of improving and synchronizing the bud...

  14. Progress and hurdles to forecasting phenology: How networked experiments and a species' traits framework can improve predictions with climate change

    Science.gov (United States)

    Wolkovich, E. M.; Cook, B. I.

    2012-12-01

    Accurate predictions of the timing of plant leafing and flowering are critical to models of global carbon budgets and future ecosystem services under climate change scenarios. Yet useful predictions have proven difficult for all but a handful of well-studied tree and crop species; further, comparisons of predictions across methods have highlighted large inconsistencies, which suggest robust forecasting of future ecosystems' plant phenology is still not within reach. Here I highlight how new approaches in ecological research could rapidly contribute to improved understanding of plant phenology across species, growing seasons and ecosystems. I first show how re-designed warming experiments--including standardized methods and analyses--would allow more useful comparisons with other methods and improved opportunities to study non-linearities and phenological cues beyond temperature. I then highlight how a species trait framework is critical for predicting shifts across years and ecosystems. I show that invasive species are generally 20-40% more sensitive to temperature than native species in temperate ecosystems--with responses in summer drought systems more complex and soil moisture dependent. Additionally, I show that annual species are 20% more temperature sensitive than perennials. Such species' responses may be especially critical for predicting longer growing seasons and their related carbon balances in future systems. Combined with a returned focus to the physiology of phenology and standardized experimental approaches ecologically-focused climate change research can allow rapid progress in understanding plant phenology across species and ecosystems.

  15. The influence of seasonal rainfall upon Sahel vegetation

    DEFF Research Database (Denmark)

    Proud, Simon Richard; Rasmussen, Laura Vang

    2011-01-01

    include changes in total yearly rainfall, land-use change and migration. But these factors are not fully explanatory. This study addresses other possible factors for variation in vegetation patterns through the analysis of the Normalized Difference Vegetation Index (NDVI) produced by satellite sensors. We...... focus on precipitation, but instead of looking at the total yearly amount of rainfall, the intra-annual variation is examined. Here we show that plant growth is strongly correlated with the number and frequency of days within the rainy season upon which there is no rainfall. Furthermore, we find...... that if the start of the growing season, or the period in which the peak growth of vegetation occurs, is especially dry then plant growth may be stunted throughout the remainder of the season. These results enable better understanding of climate dynamics in the Sahel and allow more accurate forecasting of crop...

  16. A model to predict the beginning of the pollen season

    DEFF Research Database (Denmark)

    Toldam-Andersen, Torben Bo

    1991-01-01

    In order to predict the beginning of the pollen season, a model comprising the Utah phenoclirnatography Chill Unit (CU) and ASYMCUR-Growing Degree Hour (GDH) submodels were used to predict the first bloom in Alms, Ulttirrs and Berirln. The model relates environmental temperatures to rest completion...... and bud development. As phenologic parameter 14 years of pollen counts were used. The observed datcs for the beginning of the pollen seasons were defined from the pollen counts and compared with the model prediction. The CU and GDH submodels were used as: 1. A fixed day model, using only the GDH model...... for fruit trees are generally applicable, and give a reasonable description of the growth processes of other trees. This type of model can therefore be of value in predicting the start of the pollen season. The predicted dates were generally within 3-5 days of the observed. Finally the possibility of frost...

  17. It's Open Season on Ticks

    Science.gov (United States)

    It’s Open Season on Ticks Protect yourself from tickborne disease this hunting season Ticks feed on the blood of animals (such as rodents, rabbits, deer, and birds), but will bite humans too. Ticks live in grassy or wooded areas, or on the animals themselves. Hunting brings you ...

  18. Seasonal Affective Disorder: For Teens

    Science.gov (United States)

    ... Feelings Expert Answers Q&A Movies & More for Teens Teens site Sitio para adolescentes Body Mind Sexual Health ... Search English Español Seasonal Affective Disorder KidsHealth / For Teens / Seasonal Affective Disorder What's in this article? What ...

  19. Regional-seasonal weather forecasting

    Energy Technology Data Exchange (ETDEWEB)

    Abarbanel, H.; Foley, H.; MacDonald, G.; Rothaus, O.; Rudermann, M.; Vesecky, J.

    1980-08-01

    In the interest of allocating heating fuels optimally, the state-of-the-art for seasonal weather forecasting is reviewed. A model using an enormous data base of past weather data is contemplated to improve seasonal forecasts, but present skills do not make that practicable. 90 references. (PSB)

  20. 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.

  1. Seasonal Changes in Arctic Dissolved Organic Matter

    Science.gov (United States)

    Boot, C. M.; Wallenstein, M. D.; Schimel, J.

    2011-12-01

    The Arctic is a landscape in flux. Temperatures are shifting upward and plant communities are transitioning from tussock to shrub tundra in some regions. Decomposition processes sensitive to temperature, moisture, and plant inputs are controls on the source/sink dynamics of the Arctic C pool. The response of decomposition to warming will, in part, determine if the Arctic C pool feeds back positively or negatively to climate change. The portion of the C pool immediately available to decomposers is dissolved organic matter (DOM). The aim of this is study is to examine the molecular composition of DOM to determine which components vary seasonally in soil pore water among three vegetation types at Toolik Field Station in Alaska. Vegetation types include wet sedge (Carex aquatilis and Eriophorum angustifolium), moist acidic tussock (E. vaginatum) and shrub tundra (Betula nana and Salix sp.). These sites were sampled during winter/summer transitions in 2010 in order to capture both growing season and winter dynamics. We expected the chemical composition of DOM in pore water to be distinct among plant communities due to differences in root exudates, litter chemistry and microbial community; and vary seasonally due to shifting temperature and water availability and their impacts on decomposition of DOM. Soil pore water was isolated through centrifugation and is being characterized with ultra high performance liquid chromatography (UPLC) in line with a quadrupole time of flight mass spectrometer (QTOF-MS) as well as with specific UV absorbance at 254 nm (SUVA), and excitation emission matrices (EEMs) generated by fluorescence spectroscopy. The DOM concentrations across vegetation types show consistent seasonal patterns, spiking at thaw, and declining through late summer. As soils freeze these patterns diverge-in tussock soils DOM concentration decreases slightly, while in shrub and wet sedge sites it increases. SUVA values (indicator of aromaticity) were consistent among

  2. HYDROPONICS TECHNOLOGY TO GROW PLANTS WITHOUT SOIL

    Directory of Open Access Journals (Sweden)

    P. V. Shishkin

    2017-01-01

    Full Text Available The method of hydroponics for growing plants without soil has been developed, where the many advantages are: the high technological performance; reduce of expenses; economy in watering and fertilizers due to lack of drainage system and extra engineering needed for solution circulation; reduce of exploitations expenses due to lack of soil tilling. There is also no problem concerning the root rots that are typical for all methods of growing plants without soil. This allows growing the plants with large root volume and prolonged period of vegetation. Efficiency of this system  has been proven by multi-year experiments. It was shown  that  vegetable crop  such as cucumber,  the root system of which is very sensible to oxygen deficiency, well grew, developed and gave fruits on the vegetation tray.

  3. NOVA making stuff: Season 2

    Energy Technology Data Exchange (ETDEWEB)

    Leombruni, Lisa [WGBH Educational Foundation, Boston, MA (United States); Paulsen, Christine Andrews [Concord Evaluation Group, Concord, MA (United States)

    2014-12-12

    Over the course of four weeks in fall 2013, 11.7 million Americans tuned in to PBS to follow host David Pogue as he led them in search of engineering and scientific breakthroughs poised to change our world. Levitating trains, quantum computers, robotic bees, and bomb-detecting plants—these were just a few of the cutting-edge innovations brought into the living rooms of families across the country in NOVA’s four-part series, Making Stuff: Faster, Wilder, Colder, and Safer. Each of the four one-hour programs gave viewers a behind-the-scenes look at novel technologies poised to change our world—showing them how basic research and scientific discovery can hold the keys to transforming how we live. Making Stuff Season 2 (MS2) combined true entertainment with educational value, creating a popular and engaging series that brought accessible science into the homes of millions. NOVA’s goal to engage the public with such technological innovation and basic research extended beyond the broadcast series, including a variety of online, educational, and promotional activities: original online science reporting, web-only short-form videos, a new online quiz-game, social media engagement and promotion, an educational outreach “toolkit” for science educators to create their own “makerspaces,” an online community of practice, a series of nationwide Innovation Cafés, educator professional development, a suite of teacher resources, an “Idealab,” participation in national conferences, and specialized station relation and marketing. A summative evaluation of the MS2 project indicates that overall, these activities helped make a significant impact on the viewers, users, and participants that NOVA reached. The final evaluation conducted by Concord Evaluation Group (CEG) confidently concluded that the broadcast, website, and outreach activities were successful at achieving the project’s intended impacts. CEG reported that the MS2 series and website content were

  4. Geothermal progress monitor. Progress report No. 1

    Energy Technology Data Exchange (ETDEWEB)

    1979-12-01

    Progress is reported on the following: electrical uses, direct-heat uses, drilling activities, leases, geothermal loan guarantee program, general activities, and legal, institutional, and regulatory activites. (MHR)

  5. Arithmetic Progressions on Conics.

    Science.gov (United States)

    Ciss, Abdoul Aziz; Moody, Dustin

    2017-01-01

    In this paper, we look at long arithmetic progressions on conics. By an arithmetic progression on a curve, we mean the existence of rational points on the curve whose x -coordinates are in arithmetic progression. We revisit arithmetic progressions on the unit circle, constructing 3-term progressions of points in the first quadrant containing an arbitrary rational point on the unit circle. We also provide infinite families of three term progressions on the unit hyperbola, as well as conics ax 2 + cy 2 = 1 containing arithmetic progressions as long as 8 terms.

  6. Seasonality of volcanic eruptions

    Science.gov (United States)

    Mason, B.; Pyle, D.; Dade, B.; Jupp, T.

    2003-04-01

    An analysis of volcanic activity in the last three hundred years reveals that the frequency of onset of volcanic eruptions varies systematically with the time of year. We analysed the Smithsonian catalogue of more than 3200 subaerial eruptions recorded during the last 300 years. We also investigated continuous records, which are not part of the general catalogue, of individual explosions at Sakurajima volcano (Japan, 150 events per year since 1955) and Semeru (Indonesia, 100,000 events during the period 1997-2000). A higher proportion (as much as 18 percent of the average monthly rate) of eruptions occur worldwide between December and March. This observation is statistically significant at above the 99 percent level. This pattern is independent of the time interval considered, and emerges whether individual eruptions are counted with equal weight or with weights proportional to event explosivity. Elevated rates of eruption onset in boreal winter months are observed in northern and southern hemispheres alike, as well as in most volcanically-active regions including, most prominently, the 'Ring of Fire' surrounding the Pacific basin. Key contributors to this regional pattern include volcanoes in Central and South America, the volcanic provinces of the northwest Pacific rim, Indonesia and the southwest Pacific basin. On the smallest spatial scales, some individual volcanoes for which detailed histories exist exhibit peak levels in eruption activity during November-January. Seasonality is attributed to one or more mechanisms associated with the annual hydrological cycle, and may correspond to the smallest time-scale over which fluctuations in stress due to the redistribution of water-masses are felt by the Earth's crust. Our findings have important ramifications for volcanic risk assessment, and offer new insight into possible changes in volcanic activity during periods of long-term changes in global sea level.

  7. Metallosis: A complication in the guided growing rod system used in treatment of scoliosis

    Directory of Open Access Journals (Sweden)

    Jae Hyuk Yang

    2017-01-01

    Full Text Available Soft tissue reaction following metallic debris formation with the use of guided growing rod system has not been previously reported in human. The purpose of this study is to report complications caused by metallosis in a guided growing rod system. A 9-year-old female patient, who underwent treatment for the progressive idiopathic scoliosis (with Cobb's angle of 71° with the guided growing rod system. Her Cobb's angle was corrected to 13° with the index surgery. During the 5 years postoperative period, she manifested recurrent episodes of skin irritation and progressive worsening of lateral curvature of the spine to an angle of 57°. Furthermore, at her final followup, Risser stage 4 with a gain in height of 26.4 cm was achieved. Considering adequate growth attainment and deterioration in the curvature, revision surgery with fusion was performed. Postoperative Cobb's angle of 23° was achieved with the final correction. During the revisional surgery, signs of implant wear and metallosis were observed at the location of the unconstrained screws. On histological evaluation, chronic inflammation with foreign body granules was seen. However, titanium level in the body was within normal range. She was discharged without any complications. More research on implant wear as a complication in the guided growing rod system is necessary before its widespread use. The occurrence of metallosis with the use of guided growing rod system in growing young children should be considered, when designing the implants.

  8. A Little Salesmanship "Grows" a Long Way

    Science.gov (United States)

    Montas, Leah

    2012-01-01

    Goshen Elementary PTA's membership shrank the first year the author was PTA president. In the back of her mind, she was bothered by the fact that their membership numbers had dropped. So, after she attended a regional session with her vice president on growing membership, she got the courage to propose something different. They discussed with…

  9. Pueblo Girls: Growing Up in Two Worlds.

    Science.gov (United States)

    Keegan, Marcia

    This book portrays San Ildefonso Pueblo on the east bank of the Rio Grande river in New Mexico through the lives of Sonja, age 10, and her sister Desiree, age 8. Growing up in San Ildefonso Pueblo, the girls enjoy the same activities as other American girls, such as basketball, cheerleading, playing video games, and sending e-mail. But they also…

  10. The Growing-Skull Fracture of Childhood

    African Journals Online (AJOL)

    secondary neuroblastoma, leukaemic deposits, and osteo- myelitis, but none of these will have the clear-cut and elongated appearance of the growing fracture. Of considerable interest is the suggestion made by. Alajouanine and Thurel,' that at least some of the holes found in ancient skulls, long cited by archaeologists as.

  11. Preliminary characterization of slow growing rhizobial strains ...

    African Journals Online (AJOL)

    COMPAQ

    2016-05-18

    May 18, 2016 ... transplanted to grow hydroponically in modified Gibson system. (Vincent, 1970). The N-free nutrient solution medium was used as described by FAO (1983). Seedlings inoculation. The nodule isolates were grown for 7 days in YM medium at 28°C for 150 rpm on a rotary shaker procured from Sigma-Aldrich ...

  12. Body Talk for Boys Growing Up.

    Science.gov (United States)

    Stubbs, Margaret L.

    This pamphlet, targeted to boys, discusses issues surrounding puberty. The introduction describes the reaction of parents' to their children's process of growing up, as well as the reaction of other boys and girls to the physical changes of puberty. Physical changes that happen during puberty for girls and boys are listed. Books for boys on…

  13. Mass-marketing fraud : a growing concern

    OpenAIRE

    Whitty, Monica T.

    2015-01-01

    Mass-marketing fraud is a growing international problem. Victims of this crime often experience a double hit, losing money as well as being psychologically affected. Understanding how criminals exploit online communication to develop trust and persuade individuals to give up their money is key to future work on the development of prevention programs.

  14. Growth, haematological and biochemical responses of growing ...

    African Journals Online (AJOL)

    Growth, haematological and biochemical responses of growing lambs injected. A.N.M Nour El-Din, S.Z El-Zarkouny, S.Z El-Zarkouny, H Ghobashy, H Ghobashy, E.I Abdel-Gawad, E.I Abdel-Gawad, D.J Kesler, D.J Kesler ...

  15. Preliminary characterization of slow growing rhizobial strains ...

    African Journals Online (AJOL)

    In this paper, we did some preliminary characterization of six slow growing rhizobial strains, isolated from Retama monosperma (L.) Boiss. root nodules sampled from 3 sites along the coast of Oran (CapeFalcon, Bousfer and MersElHadjadj) in Northwestern Algeria. Results of this study showed that all strains had a very ...

  16. Play Games to Grow up Bilingual

    DEFF Research Database (Denmark)

    Valente, Andrea; Marchetti, Emanuela

    2007-01-01

    A new kind of computer game is proposed, to support the linguistic development of primary school children, growing in multilingual environments: with it players will be able to simultaneously learn multiple languages. The novel idea is to treat words in different languages as physical items, that...

  17. Play Games to Grow up Bilingual

    DEFF Research Database (Denmark)

    Valente, Andrea; Marchetti, Emanuela

    2008-01-01

    A new kind of computer game is proposed, to support the linguistic development of primary school children, growing in multilingual environments: with it players will be able to simultaneously learn multiple languages. The novel idea is to treat words in different languages as physical items, that...

  18. CARROT SEED GROWING THROUGH WINTERING SEEDLINGS

    Directory of Open Access Journals (Sweden)

    A. P. Zvedenuk

    2017-01-01

    Full Text Available The results of research work on carrot seed growing through wintering seedlings carried out at laboratory of seed studies and seed production of Transnistrian Research Institute of Agriculture, on the soil of the first terrace at the rive Dniester were presented in the article. Seed bearing plants of garden carrot ‘Krasavka’ were the object of the study. The seeds were sown to produce the seedlings on 15-16 August. In the first decade of December the plants were covered with white agrotextile with density 23g/m2 that was removed at the beginning of April. The proportion of plant that passed the winter depending on a year of cultivation was 95-100% under argotextile, and 50-80% in open plot. The plants under agrotextile reached 28 cm a high and had 5-7 well-developed leaves, while those on the open plot were at phase of active foliage growing about 10-13 cm. long. Thus, for early mechanized planting in optimal terms the wintering seedlings grown under agrotextile had the best biometrical characteristics. Moreover the outcome of carrot seedlings was 1.2-1.25 million per hectare. Such quantity of seedlings was sufficient to plant 9-10 ha of carrot plants, where the coefficient of multiplication reached 9-10, and only 3 when growing seeds through mother plant as biennial culture. Viability of seed plants grown through seedlings was 100%. Losses of plant with weight 120-150 grams from damage caused by diseases was 23%. The seed yield, when growing seedlings was 639 kg/ha, but growing through plants was 332 kg/ha. The seed outcome suitable for precise mechanized sowing through seedling growing was 77%, where seed germination was 90%, with seed fraction 1.51 and >2.0 mm. It was essentially improved their yielding characteristics. Seed outcome from this fraction obtained through planting method was 32%. The proportion of seeds in fraction 1-1.5 mm was 68%. For mechanized single-seed sowing, the seeds can be used only after mini-coating. The seed

  19. Growing green electricity: progress and strategies for use of photosystem I for sustainable photovoltaic energy conversion.

    Science.gov (United States)

    Nguyen, Khoa; Bruce, Barry D

    2014-09-01

    Oxygenic photosynthesis is driven via sequential action of Photosystem II (PSII) and (PSI)reaction centers via the Z-scheme. Both of these pigment-membrane protein complexes are found in cyanobacteria, algae, and plants. Unlike PSII, PSI is remarkably stable and does not undergo limiting photo-damage. This stability, as well as other fundamental structural differences, makes PSI the most attractive reaction centers for applied photosynthetic applications. These applied applications exploit the efficient light harvesting and high quantum yield of PSI where the isolated PSI particles are redeployed providing electrons directly as a photocurrent or, via a coupled catalyst to yield H₂. Recent advances in molecular genetics, synthetic biology, and nanotechnology have merged to allow PSI to be integrated into a myriad of biohybrid devices. In photocurrent producing devices, PSI has been immobilized onto various electrode substrates with a continuously evolving toolkit of strategies and novel reagents. However, these innovative yet highly variable designs make it difficult to identify the rate-limiting steps and/or components that function as bottlenecks in PSI-biohybrid devices. In this study we aim to highlight these recent advances with a focus on identifying the similarities and differences in electrode surfaces, immobilization/orientation strategies, and artificial redox mediators. Collectively this work has been able to maintain an annual increase in photocurrent density (Acm⁻²) of ~10-fold over the past decade. The potential drawbacks and attractive features of some of these schemes are also discussed with their feasibility on a large-scale. As an environmentally benign and renewable resource, PSI may provide a new sustainable source of bioenergy. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy. Copyright © 2013. Published by Elsevier B.V.

  20. Why Do Model Tropical Cyclones Grow Progressively in Size and Decay in Intensity after Reaching Maturity

    Science.gov (United States)

    2015-08-17

    anonymous reviewers for their thoughtful comments on the original version of the manuscript. RKS and GK acknowledge financial sup- port for this research from...Nichols, T. A. Cram , and A. B. Saun- ders, 2006: A vortical hot tower route to tropical cyclogenesis. J. Atmos. Sci., 63, 355–386. Montgomery, M. T

  1. Mechanical properties of growing melanocytic nevi and the progression to melanoma.

    Directory of Open Access Journals (Sweden)

    Alessandro Taloni

    Full Text Available Melanocytic nevi are benign proliferations that sometimes turn into malignant melanoma in a way that is still unclear from the biochemical and genetic point of view. Diagnostic and prognostic tools are then mostly based on dermoscopic examination and morphological analysis of histological tissues. To investigate the role of mechanics and geometry in the morpholgical dynamics of melanocytic nevi, we study a computation model for cell proliferation in a layered non-linear elastic tissue. Numerical simulations suggest that the morphology of the nevus is correlated to the initial location of the proliferating cell starting the growth process and to the mechanical properties of the tissue. Our results also support that melanocytes are subject to compressive stresses that fluctuate widely in the nevus and depend on the growth stage. Numerical simulations of cells in the epidermis releasing matrix metalloproteinases display an accelerated invasion of the dermis by destroying the basal membrane. Moreover, we suggest experimentally that osmotic stress and collagen inhibit growth in primary melanoma cells while the effect is much weaker in metastatic cells. Knowing that morphological features of nevi might also reflect geometry and mechanics rather than malignancy could be relevant for diagnostic purposes.

  2. Effects of use and disuse on growing skeletal muscle

    Energy Technology Data Exchange (ETDEWEB)

    Darr, K.C.

    1988-01-01

    In the first series of experiments, the time course and extent of satellite cell activation were studied in the soleus and extensor digitorum longus (EDL) muscles of untrained growing and mature rats after a single bout of prolonged eccentric treadmill running. Satellite cell mitotic activity was quantitated in autoradiographs of whole-fiber segments after injection of {sup 3}H-thymidine. Labelling in growing muscles progressively increased to peak at 72 h postexercise, whereas mature muscles exhibited an earlier peak at 24 (soleus) and 48 (EDL) h, followed by a more rapid decline to control levels by 120 h postexercise. In all exercised muscles the calculated satellite cell activation was far greater than required to repair the small number of necrotic fibers identified at the light-microscopic levels. In a second series of experiments, postnatal growth of 20d old rat EDL and soleus muscles was studied after 3, 10, 20 and 30d of hindlimp suspension. Radial growth of suspended soleus myofibers was attenuated 76% over the total suspension period. Longitudinal growth rate, however, was accelerated 40% over weight-bearing controls. In contrast radial and longitudinal growth of EDL myofibers were minimally affected under similar conditions. Both the number and proliferative activity of satellite cells were severely reduced in individual myofibers by day 3 of suspension.

  3. Effects of use and disuse on growing skeletal muscle

    International Nuclear Information System (INIS)

    Darr, K.C.

    1988-01-01

    In the first series of experiments, the time course and extent of satellite cell activation were studied in the soleus and extensor digitorum longus (EDL) muscles of untrained growing and mature rats after a single bout of prolonged eccentric treadmill running. Satellite cell mitotic activity was quantitated in autoradiographs of whole-fiber segments after injection of 3 H-thymidine. Labelling in growing muscles progressively increased to peak at 72 h postexercise, whereas mature muscles exhibited an earlier peak at 24 (soleus) and 48 (EDL) h, followed by a more rapid decline to control levels by 120 h postexercise. In all exercised muscles the calculated satellite cell activation was far greater than required to repair the small number of necrotic fibers identified at the light-microscopic levels. In a second series of experiments, postnatal growth of 20d old rat EDL and soleus muscles was studied after 3, 10, 20 and 30d of hindlimp suspension. Radial growth of suspended soleus myofibers was attenuated 76% over the total suspension period. Longitudinal growth rate, however, was accelerated 40% over weight-bearing controls. In contrast radial and longitudinal growth of EDL myofibers were minimally affected under similar conditions. Both the number and proliferative activity of satellite cells were severely reduced in individual myofibers by day 3 of suspension

  4. Linyphiid spider populations in sustainable wheat‐clover bi‐cropping compared to conventional wheat‐growing practice

    DEFF Research Database (Denmark)

    Gravesen, Eigil Vestergaard

    2008-01-01

    compared to the mean density levels of the conventional growing systems in two consecutive growing seasons. Particularly, Bathyphantes gracilis and Tenuiphantes tenuis took advantage of the more heterogeneous conditions with high secondary vegetation layer density and high food animal supply in the bi......-crop plots compared to the more homogeneous conditions under conventional wheat-growing practices with low food animal supply. Structural equation modelling with a data set pooled from four different wheat-growing practices shows that the linyphiid juvenile production is influenced by the number......Linyphiid web densities in wheat-clover bi-crop systems where winter wheat was grown in an under-storey of white clover were compared with web densities estimated in conventional wheat-growing systems. The web densities in the wheat-clover bi-crop systems were on average between 200 and 250 webs...

  5. Human land-use change impacts rainfall seasonality

    Science.gov (United States)

    Wang-Erlandsson, Lan; van der Ent, Ruud; Fetzer, Ingo; Keys, Patrick; Savenije, Hubert; Gordon, Line

    2017-04-01

    Anthropogenic land-use change has profoundly changed the Earth's terrestrial water cycle. Studies of how land-use change induced modifications in terrestrial evaporation alters atmospheric moisture content and subsequent precipitation (i.e.., moisture recycling) have primarily focussed on the annual mean impacts. However, the functioning of agriculture and ecosystems are often dependent on the onset, length, and magnitude of the growing season rainfall. Hence, rainfall seasonality is of crucial importance. Here, we (1) analyse how humans have altered rainfall seasonality through land-use change induced modification of moisture recycling, (2) investigate the mechanisms for the rainfall seasonality changes, and (3) discuss how downwind regions may be affected by rainfall seasonality changes. We model human land-use change effects (including irrigation) on evaporation using the global hydrological model STEAM and trace precipitation changes using the atmospheric moisture tracking scheme WAM-2layers. We find that changes in rainfall seasonality is considerably stronger than changes to mean annual precipitation, and is accentuated in locations downwind to significant land-use changes. In particular, we associate sustained rainfall season downwind with land-use types that favour transpiration. This effect is explained by the long residence time of transpiration in both the unsaturated zone and the atmosphere, in contrast to interception and soil evaporation. Our results shed light on the human influence of hydrological systems both locally and at large distances, and which may have crucial implications for agricultural production and ecosystem functioning. These insights are important in a time of both rapid land-use and climate change.

  6. 2007 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  7. 2006 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  8. 2009 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  9. 2008 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  10. 2010 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  11. 2012 Swimming Season Fact Sheets

    Science.gov (United States)

    To help beachgoers make informed decisions about swimming at U.S. beaches, EPA annually publishes state-by-state data about beach closings and advisories for the previous year's swimming season. These fact sheets summarize that information by state.

  12. Flublok Seasonal Influenza (Flu) Vaccination

    Science.gov (United States)

    ... Vaccine Safety and Pregnant Women Febrile Seizures Following Vaccination Flu Vaccine and People with Egg Allergies Guillain- ... Flu Vaccines Quadrivalent Influenza Vaccine Intradermal Influenza (Flu) Vaccination Fluzone High-Dose Seasonal Influenza Vaccine Cell-Based ...

  13. Seasonal Allergies: Diagnosis, Treatment & Research

    Science.gov (United States)

    ... this page please turn JavaScript on. Feature: Seasonal Allergies Diagnosis, Treatment & Research Past Issues / Spring 2015 Table of Contents Diagnosis Testing for Allergies Knowing exactly what you are allergic to can ...

  14. What is the current state of scientific knowledge with regard to seasonal and decadal forecasting?

    International Nuclear Information System (INIS)

    Smith, Doug M; Scaife, Adam A; Kirtman, Ben P

    2012-01-01

    Environmental factors, such as the frequency, intensity and duration of extreme weather events, are important drivers of migration and displacement of people. There is therefore a growing need for regional climate predictions for the coming seasons to decades. This paper reviews the current state of the art of seasonal to decadal climate prediction, focusing on the potential sources of skill, forecasting techniques, current capability and future prospects. (letter)

  15. Tobacco-control policies in tobacco-growing states: where tobacco was king.

    Science.gov (United States)

    Fallin, Amanda; Glantz, Stanton A

    2015-06-01

    POLICY POINTS: The tobacco companies prioritized blocking tobacco-control policies in tobacco-growing states and partnered with tobacco farmers to oppose tobacco-control policies. The 1998 Master Settlement Agreement, which settled state litigation against the cigarette companies, the 2004 tobacco-quota buyout, and the companies' increasing use of foreign tobacco led to a rift between the companies and tobacco farmers. In 2003, the first comprehensive smoke-free local law was passed in a major tobacco-growing state, and there has been steady progress in the region since then. Health advocates should educate the public and policymakers on the changing reality in tobacco-growing states, notably the major reduction in the volume of tobacco produced. The 5 major tobacco-growing states (Kentucky, North Carolina, South Carolina, Tennessee, and Virginia) are disproportionately affected by the tobacco epidemic, with higher rates of smoking and smoking-induced disease. These states also have fewer smoke-free laws and lower tobacco taxes, 2 evidence-based policies that reduce tobacco use. Historically, the tobacco farmers and hospitality associations allied with the tobacco companies to oppose these policies. This research is based on 5 detailed case studies of these states, which included key informant interviews, previously secret tobacco industry documents (available at http://legacy.library.ucsf.edu), and media articles. This was supplemented with additional tobacco document and media searches specifically for this article. The tobacco companies were particularly concerned about blocking tobacco-control policies in the tobacco-growing states by promoting a pro-tobacco culture, beginning in the late 1960s. Nevertheless, since 2003, there has been rapid progress in the tobacco-growing states' passage of smoke-free laws. This progress came after the alliance between the tobacco companies and the tobacco farmers fractured and hospitality organizations stopped opposing smoke

  16. Seasonal mapping of NICU temperature.

    Science.gov (United States)

    Thomas, Karen A; Magbalot, Almita; Shinabarger, Kelley; Mokhnach, Larisa; Anderson, Marilyn; Diercks, Kristi; Millar, April; Thorngate, Lauren; Walker, Wendy; Dilback, Nancy; Berkan, Maureen

    2010-10-01

    To create a thermal map of ambient air, radiant, and evaporative temperatures and humidity throughout the NICU nursery by season across a calendar year. Each cubicle of the 32-bed NICU, distributed across 5 rooms, in a level III nursery was measured. Temperatures were recorded at a consistent time on one day during January, April, July, and October. : An electronic monitor (QUESTemp ° 34; Quest Technologies, Oconomowoc, Wisconsin) was used to measure dry bulb, wet bulb, and globe thermometer temperatures. Analysis of variance revealed statistically significant (P ≤ .000) differences in season, room, and season by room interaction. Room ambient air temperatures differed by less than 2 ° F across season. Radiant temperature paralleled air temperature. Humidity, the predominant difference across season, produced evaporative temperatures considerably lower than room air temperature, and the gradient between mean nursery dry bulb temperature and wet bulb temperature was 9.3 ° F in summer and 16.8 ° F in winter. The thermal map revealed seasonal thermal differences, particularly in humidity level and evaporative temperature. Room temperature alone does not reflect the total thermal environment. Recommendations include periodic assessment of nurseries along with air, evaporative, and radiant temperatures as well as humidity to fully appreciate the impact of the thermal environment on infants.

  17. GEOS-5 seasonal forecast system

    Science.gov (United States)

    Borovikov, Anna; Cullather, Richard; Kovach, Robin; Marshak, Jelena; Vernieres, Guillaume; Vikhliaev, Yury; Zhao, Bin; Li, Zhao

    2017-09-01

    Ensembles of numerical forecasts based on perturbed initial conditions have long been used to improve estimates of both weather and climate forecasts. The Goddard Earth Observing System (GEOS) Atmosphere-Ocean General Circulation Model, Version 5 (GEOS-5 AOGCM) Seasonal-to-Interannual Forecast System has been used routinely by the GMAO since 2008, the current version since 2012. A coupled reanalysis starting in 1980 provides the initial conditions for the 9-month experimental forecasts. Once a month, sea surface temperature from a suite of 11 ensemble forecasts is contributed to the North American Multi-Model Ensemble (NMME) consensus project, which compares and distributes seasonal forecasts of ENSO events. Since June 2013, GEOS-5 forecasts of the Arctic sea-ice distribution were provided to the Sea-Ice Outlook project. The seasonal forecast output data includes surface fields, atmospheric and ocean fields, as well as sea ice thickness and area, and soil moisture variables. The current paper aims to document the characteristics of the GEOS-5 seasonal forecast system and to highlight forecast biases and skills of selected variables (sea surface temperature, air temperature at 2 m, precipitation and sea ice extent) to be used as a benchmark for the future GMAO seasonal forecast systems and to facilitate comparison with other global seasonal forecast systems.

  18. Differentiated seasonal vegetation cover dynamics of degraded grasslands in Inner Mongolia recorded by continuous photography technique.

    Science.gov (United States)

    Xu, Xiaotian; Liu, Hongyan; Liu, Xu; Song, Zhaoliang; Wang, Wei; Qiu, Shuang

    2017-05-11

    Influence of climate change on the grassland phenology has attracted more and more attentions of ecologists. Although dozens of studies have been conducted, there have been few records examining the phenology differences of grasslands with different plant species compositions. Using continuous photography and image processing methods, this study examined seasonal vegetation cover dynamics of grasslands along a degradation gradient to clarify the influence of vegetation composition on the dynamics of vegetation cover during growing season. Our results revealed that phenological patterns of grasslands differentiated with their degradation status. Abandoned farmland (AF) and severely degraded grassland (SD) with most annuals and least climax species had the earliest start of growing season, while AF and extremely degraded grassland (ED) dominated by grasses had the earliest end of growing season. The start and end of growing season were strongly related to the relative cover of climax species and grasses. The results presented in this study support the possibility of using digital photography to capture the role of plant species composition on vegetation phenology in grasslands.

  19. [Primary progressive apraxia].

    Science.gov (United States)

    Kondo, Masaki

    2011-10-01

    Similar to primary progressive aphasia, primary progressive apraxia has been considered to cause slowly progressive apraxia without dementia and to be a dependent disease. Of the 3 cases reported by De Renzi in 1986, 1 case showed slowly progressive apraxia without dementia. Since then, cases of primary progressive apraxia have been reported occasionally. Studies on primary progressive apraxia indicate that not only focal lesions caused by vascular disease or brain trauma but also lesions caused by neurodegenerative disease can cause apraxia alone, thereby supporting the hypothesis that apraxia-associated neurodegeneration may develop in cases of primary progressive apraxia. The pathogenesis of primary progressive apraxia is yet to be elucidated. Clinical features of primary progressive apraxia are not precisely distinguishable from those of corticobasal degeneration (CBD); further, previous studies have indicated that the brain pathology observed in primary progressive apraxia is consistent with that in Alzheimer disease (AD) or Pick disease. "Primary" progressive apraxia may be intrinsically different from slowly progressive apraxia that is associated with CBD, AD, or Pick disease and may show specific pathological findings. On the other hand, primary progressive apraxia may not be a dependent disease but a syndrome characterized by prolonged neurodegeneration that is observed in various degenetive dementias such as CBD, AD, or Pick disease.

  20. Petroleum demand continues to grow but slowly

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    While it is always entertaining and intellectually stimulating to look at all the marvelous technological alternatives just around the corner for transport, the transport task in Australia continues to grow and so does petroleum consumption. Australia presently consumes more than 750,000 barrels per day of petroleum products. Latest figures are given for petroleum consumption up to the end of August 1998. They indicate that total demand for petrol has continued to grow, but very slowly. Growth in 1997-1998 compared with 1996-1997 was only 0.3%. This trend for very low growth has been continued into July and August, perhaps indicative of a slow down in the economy

  1. IntelliGrow 2.0

    DEFF Research Database (Denmark)

    Markvart, Jakob; Aaslyng, Jesper Peter Mazanti; Kalita, Sebastian

    2008-01-01

    the system in full scale in five Danish commercial nurseries. The four steps to reach the goal are: 1) development of a demonstrator giving the grower advice on optimal climate control based on the IntelliGrow concept 2) testing the demonstrator at research facilities followed by tests at growers 3......) development of an active climate control system that will take full control of the greenhouse climate based on the overall goals set by the grower 4) tests of the active climate control system at research facilities and at the growers. It will be possible to adjust the control by adding new components......Since 1996 a dynamic model based climate control concept (IntelliGrow) has been developed in Denmark. The aim of the system is to adjust the greenhouse climate dynamic, so that the natural resources are used as optimal as possible. The concept has been proved to work in both growth chamber...

  2. Seasonal temperatures have more influence than nitrogen fertilizer rates on cucumber yield and nitrogen uptake in a double cropping system

    International Nuclear Information System (INIS)

    Guo Ruiying; Li Xiaolin; Christie, Peter; Chen Qing; Zhang Fusuo

    2008-01-01

    Two-year greenhouse cucumber experiments were conducted to investigate seasonal effects on fruit yield, dry matter allocation, and N uptake in a double-cropping system with different fertilizer management. Seasonal effects were much greater than fertilizer effects, and winter-spring (WS) cucumber attained higher fruit yields and N uptake than autumn-winter (AW) cucumber due to lower cumulative air temperatures during fruit maturation in the AW season. Fertilizer N application and apparent N loss under recommended N management (Nmr) decreased by 40-78% and 33-48% without yield loss compared to conventional N management (Nmt) over four growing seasons. However, there were no seasonal differences in N recommendations, taking into consideration seasonal differences in crop N demand, critical nutrient supply in the root zone and N mineralization rate. - Nitrogen inputs can be reduced to minimize N losses to the environment while maintaining yields but N recommendations must reflect seasonal temperature effects

  3. Shape of the growing front of biofilms

    Science.gov (United States)

    Wang, Xin; Stone, Howard A.; Golestanian, Ramin

    2017-12-01

    The spatial organization of bacteria in dense biofilms is key to their collective behaviour, and understanding it will be important for medical and technological applications. Here we study the morphology of a compact biofilm that undergoes unidirectional growth, and determine the condition for the stability of the growing interface as a function of the nutrient concentration and mechanical tension. Our study suggests that transient behaviour may play an important role in shaping the structure of a biofilm.

  4. Australia: A Growing Market for Asean Exports?

    OpenAIRE

    Tongzon, J.L.

    1988-01-01

    Much has been written regarding South East Asian countries as growing markets for Australian exports particularly in the past decade. But nothing so far has been done to examine whether ASEAN exports have also experienced some redirection towards the Australian market. The findings confirm our a priori expectations: no significant general reorientation was observed for the ASEAN group of countries, and ASEAN’s country bias declined over the period under study. This is in contrast to the Austr...

  5. Growing teratoma syndrome: clinical and radiographic characteristics.

    Science.gov (United States)

    Lee, Dennis J; Djaladat, Hooman; Tadros, Nicholas N; Movassaghi, Mehran; Tejura, Tapas; Duddalwar, Vinay; Daneshmand, Siamak

    2014-09-01

    To present an overview of our surgical experience in the management of growing teratoma syndrome. A retrospective analysis of all patients undergoing post-chemotherapy retroperitoneal lymphadenectomy between November 2005 and February 2012 revealed 15 patients who met the criteria for growing teratoma syndrome. Their clinical data, imaging characteristics, and surgical and oncological outcomes were reviewed. The median age at diagnosis was 23 years. Primary testis tumors included non-seminomatous germ cell tumor in 12 of 15 patients, seminoma in two of 15 patients and hemorrhagic mass in one patient. Mature teratoma was present in just six (40%) of the orchiectomy specimens. All patients received preoperative chemotherapy. On imaging, the median size of the largest retroperitoneal mass was 7 cm (range 3.9-24.5 cm). The median rate of linear growth was 0.5 cm/month (range 0.03-2.9), and the increase in volume was 9.2 cm(3) /month. All tumors were found to have cystic and necrotic components. Median operative time was 6.2 h (range 4.2-15.2 h). Estimated blood loss was 600 mL (range 100-7000 mL), and median length of stay was 5 days (range 3-19 days). Four patients required resection of non-retroperitoneal growing teratoma masses after post-chemotherapy retroperitoneal lymphadenectomy to achieve tumor-free status. There were two minor (Clavien I-II) and two major postoperative complications (Clavien ≥III). All patients are alive and disease free with a median duration of follow-up of 8 months (range 1-64 months). Growing teratoma syndrome tumors vary in their growth rate, but they all appear to have cystic features with necrosis elements on radiographic evaluation. Aggressive surgical excision is associated with excellent outcomes. © 2014 The Japanese Urological Association.

  6. GRoW Buffalo Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Bohm, Martha [Univ. at Buffalo, NY (United States)

    2016-04-17

    This document provides final reporting on the GRoW Home, University at Buffalo's entry to the 2015 Solar Decathlon competition in Irvine, CA. The report summarizes fundraising efforts, documents media outreach, lists online presence, analyzes the organizer's communication, describes post-competition life of the house and future employment plans for student team members. Last, it suggests improvements for future decathlons.

  7. Analytical chemistry in Brazil: healthy and growing

    OpenAIRE

    Rocha, Fábio R. P.; Pereira-Filho, Edenir R.; Nóbrega, Joaquim A.

    2009-01-01

    Chemical sciences in Brazil are growing fast and being one of the main supports for the continuous development of the country. Inspired on the 15th Brazilian Meeting on Analytical Chemistry, ENQA, with a record number of participants and communications, we have decided to review recent developments in analytical chemistry in Brazil. We have chosen the same application areas used for the thematic organization of the ENQA and have searched papers published by Brazilian authors in 7 major and ge...

  8. Primary Progressive Aphasia

    Science.gov (United States)

    ... which cause different symptoms. Semantic variant primary progressive aphasia Symptoms include these difficulties: Comprehending spoken or written ... word meanings Naming objects Logopenic variant primary progressive aphasia Symptoms include: Having difficulty retrieving words Frequently pausing ...

  9. Progressive Pigmentary Purpura

    Science.gov (United States)

    ... Category: Share: Yes No, Keep Private Progressive Pigmentary Purpura Share | Progressive pigmentary purpura (we will call it PPP) is a group ... conditions ( Schamberg's disease , Lichenoid dermatitis of Gourgerot-Blum, purpura annularis telangiectodes of Majocchi and Lichen aureus). Schamberg's ...

  10. Progressive Supranuclear Palsy

    Science.gov (United States)

    ... alterations of mood and behavior, including depression and apathy as well as progressive mild dementia. The disorder's ... alterations of mood and behavior, including depression and apathy as well as progressive mild dementia. The disorder's ...

  11. Progress in K spectroscopy

    International Nuclear Information System (INIS)

    Leith, D.W.G.S.

    1977-07-01

    The progress in the field of K* spectroscopy is reviewed within the framework of the simple harmonic oscillator quark model, and contrasted with the recent progress made in the charmonium spectroscopy

  12. Progressive Multifocal Leukoencephalopathy

    Science.gov (United States)

    ... most prominent symptoms are clumsiness; progressive weakness; and visual, speech, and sometimes personality changes. The progression of deficits leads to life-threatening disability and (frequently) death. A diagnosis of PML can ...

  13. Seasonal and diurnal trends in black carbon properties and co-pollutants in Mexico City

    Science.gov (United States)

    Retama, A.; Baumgardner, D.; Raga, G. B.; McMeeking, G. R.; Walker, J. W.

    2015-08-01

    The Mexico City metropolitan area (MCMA) is a region that continues to grow in population and vehicular traffic as well as being the largest source of short-lived climate pollutants (SLCP) in Latin America. The local city government has made significant progress in controlling some of these pollutants, i.e., ozone (O3) and carbon monoxide (CO), but particulate matter (PM2.5 and PM10) and black carbon (BC) have shown a less positive response to mitigation strategies that have been in place for almost 3 decades. For the first time, extended measurements of equivalent black carbon (eBC), derived from light absorption measurements, have been made using a Photoacoustic Extinctiometer (PAX) over a 13 month period from March 2013 through March 2014. The daily trends in workdays (Monday through Saturday) and Sunday eBC, PM2.5 and the co-pollutants CO, O3 and NOx are evaluated with respect to the three primary seasons in the MCMA: rainy, cold and dry and warm and dry. The maximum values in all of the particle and gas concentrations were significantly larger (Student's t test, P emissions over a 14 year period. This suggests that new methods may need to be developed that can decrease potentially toxic levels of this particulate pollutant.

  14. Biomass accumulation in rapidly growing loblolly pine and sweetgum

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Thomas M.; Gresham, Charles A. [Baruch Institute of Coastal Ecology and Forest Science, Clemson University, P.O. Box 596, Georgetown, SC 29442 (United States)

    2006-04-15

    Loblolly pine (Pinus taeda) and sweetgum (Liquidambar styraciflua) trees, growing in International Paper Company's study of intensive management on marginal agricultural land near Bainbridge GA, were destructively sampled at the end of the sixth growing season. All trees were single family blocks of genetically superior trees planted 2.5m apart on sub-soiled rows 3.6m apart and grown with complete competition control. Management treatments were: control, irrigation, irrigation plus fertilization, and irrigation plus fertilization plus pest control. Tree measures were basal diameter, DBH, height of live crown, diameter at base of live crown, and total height. Twenty trees of each species were destructively sampled. Stems were sectioned at 1m intervals, stem diameter determined at each end and sections were weighed green. Branches were removed and height, basal diameter, and length were measured on each branch. Branches were separated into foliated and unfoliated segments and weighed green. A stem disk and branch from each meter were returned to the lab to determine dry weight: green weight ratio. Foliated limb: foliage ratios were also determined from sub-sampled branches. Intensive culture resulted in larger growth differences for sweetgum (most intensive treatment 9.5m tall, 13.1cm DBH; control trees 5.0m tall, 6.3cm DBH) than in pine (most intensive treatment 10.3m tall, 17.7cm DBH; control, 7.6m tall, 13.4cm DBH). The pipe model of tree development explained dimensions of the upper 5m of crown with leaf biomass highly correlated to branch basal area (r{sup 2} from 0.697 to 0.947). There was a constant ratio of leaf biomass to branch basal area (50gm/cm{sup 2} for pine, 30gm/cm{sup 2} for sweetgum). We also found a constant ratio of bole basal area to cumulative branch basal area throughout the crowns. Rapidly growing pines produced about 49Mgha{sup -1} of stem biomass, 11Mgha{sup -1} of dead branch biomass, and 17Mgha{sup -1} of unfoliated branch biomass at

  15. White matter lesion progression

    DEFF Research Database (Denmark)

    Hofer, Edith; Cavalieri, Margherita; Bis, Joshua C

    2015-01-01

    BACKGROUND AND PURPOSE: White matter lesion (WML) progression on magnetic resonance imaging is related to cognitive decline and stroke, but its determinants besides baseline WML burden are largely unknown. Here, we estimated heritability of WML progression, and sought common genetic variants...... and previous association studies. RESULTS: A total of 1085 subjects showed WML progression. The heritability estimate for WML progression was low at 6.5%, and no single-nucleotide polymorphisms achieved genome-wide significance (PFour loci were suggestive (P

  16. Prenatal Development: How Your Baby Grows During Pregnancy

    Science.gov (United States)

    ... Management Education & Events Advocacy For Patients About ACOG Prenatal Development: How Your Baby Grows During Pregnancy Home ... Grows During Pregnancy FAQ156, June 2015 PDF Format Prenatal Development: How Your Baby Grows During Pregnancy Pregnancy ...

  17. Ecological and evolutionary implications of spatial heterogeneity during the off-season for a wild plant pathogen

    Science.gov (United States)

    Tack, Ayco JM; Laine, Anna-Liisa

    2014-01-01

    While recent studies have elucidated many of the factors driving parasite dynamics during the growing season, the ecological and evolutionary dynamics during the off-season (i.e. the period between growing seasons) remain largely unexplored. We combined large-scale surveys and detailed experiments to investigate the overwintering success of the specialist plant pathogen Podosphaera plantaginis on its patchily distributed host plant Plantago lanceolata in the Åland Islands. Twelve years of epidemiological data establish the off-season as a crucial stage in pathogen metapopulation dynamics, with c. 40% of the populations going extinct during the off-season. At the end of the growing season, we observed environmentally mediated variation in the production of resting structures, with major consequences for spring infection at spatial scales ranging from single individuals to populations within a metapopulation. Reciprocal transplant experiments further demonstrated that pathogen population of origin and overwintering site jointly shaped infection intensity in spring, with a weak signal of parasite adaptation to the local off-season environment. We conclude that environmentally mediated changes in the distribution and evolution of parasites during the off-season are crucial for our understanding of host–parasite dynamics, with applied implications for combating parasites and diseases in agriculture, wildlife and human disease systems. PMID:24372358

  18. Progress Towards an Interdisciplinary Science of Plant Phenology: Building Predictions Across Space, Time and Species Diversity

    Science.gov (United States)

    Wolkovich, Elizabeth M.; Cook, Benjamin I.; Davies, T. Jonathan

    2013-01-01

    Climate change has brought renewed interest in the study of plant phenology - the timing of life history events. Data on shifting phenologies with warming have accumulated rapidly, yet research has been comparatively slow to explain the diversity of phenological responses observed across latitudes, growing seasons and species. Here, we outline recent efforts to synthesize perspectives on plant phenology across the fields of ecology, climate science and evolution. We highlight three major axes that vary among these disciplines: relative focus on abiotic versus biotic drivers of phenology, on plastic versus genetic drivers of intraspecific variation, and on cross-species versus autecological approaches. Recent interdisciplinary efforts, building on data covering diverse species and climate space, have found a greater role of temperature in controlling phenology at higher latitudes and for early-flowering species in temperate systems. These efforts have also made progress in understanding the tremendous diversity of responses across species by incorporating evolutionary relatedness, and linking phenological flexibility to invasions and plant performance. Future research with a focus on data collection in areas outside the temperate mid-latitudes and across species' ranges, alongside better integration of how risk and investment shape plant phenology, offers promise for further progress.

  19. Ozone measurements in Amazonia - Dry season versus wet season

    Science.gov (United States)

    Kirchhoff, V. W. J. H.; Da Silva, I. M. O.; Browell, Edward V.

    1990-01-01

    Recent ozone measurements taken in the Amazonian rain forest environment during the wet season (April-May 1987) are described, revealling new aspects of the regional atmospheric chemistry. The measurements were part of the Amazon Boundary Layer Experiment (ABLE 2B) mission and utilized UV absorption as a measurement technique to obtain surface ozone data; 20 ozonesondes were launched in order to obtain vertical ozone profiles used to describe the upper troposphere and stratosphere. The major differences in comparison to a previous dry season experiment, which found ozone concentrations to be lower in the whole troposphere by nearly a factor of 2, are stressed.

  20. Thin film growing by the laser ablation technique: possibilities for growing of dosimetric materials

    International Nuclear Information System (INIS)

    Rojas R, E.M.; Melo M, M.; Enriquez Z, E.; Fernandez G, M.; Haro P, E.; Hernandez P, J.L.

    2005-01-01

    In this talk we will present the basics about the laser ablation technique and how it is used for thin film growing, either as a single film or a stack of thin films, as well as some methods to characterize in real time the film thickness. Finally, we will discuss the possibilities of using laser ablation for growing thin films with applications to dosimetry. (Author)

  1. Geodynamics Project. US progress report, 1975

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    The recommendations of the US Geodynamics Committee relative to program activities are presented. US Program progress is reviewed in the following areas: fine structure of the crust and upper mantle; continuous seismic reflection profiling of the deep basement: Hardeman County, Texas; Mid-Atlantic Ridge - evolution of oceanic lithosphere; internal processes and properties; crystal growing; chemical differentiation of magmas; geodynamic modelling; magnetic problems; plate boundaries; plate interiors; geodynamic syntheses; and eustatic cycles of sea level changes. (MHR)

  2. Seasonal variation in sports participation.

    Science.gov (United States)

    Schüttoff, Ute; Pawlowski, Tim

    2018-02-01

    This study explores indicators describing socio-demographics, sports participation characteristics and motives which are associated with variation in sports participation across seasons. Data were drawn from the German Socio-Economic Panel which contains detailed information on the sports behaviour of adults in Germany. Overall, two different measures of seasonal variation are developed and used as dependent variables in our regression models. The first variable measures the coefficient of (seasonal) variation in sport-related energy expenditure per week. The second variable measures whether activity drops below the threshold as defined by the World Health Organization (WHO). Results suggest that the organisational setting, the intensity and number of sports practised, and the motive for participation are strongly correlated with the variation measures used. For example, both, participation in a sports club and a commercial facility, are associated with reduced seasonal variation and a significantly higher probability of participating at a volume above the WHO threshold across all seasons. These findings give some impetus for policymaking and the planning of sports programmes as well as future research directions.

  3. Diagnosing observed characteristics of the wet season across Africa to identify deficiencies in climate model simulations

    Science.gov (United States)

    Dunning, C.; Black, E.; Allan, R. P.

    2017-12-01

    The seasonality of rainfall over Africa plays a key role in determining socio-economic impacts for agricultural stakeholders, influences energy supply from hydropower, affects the length of the malaria transmission season and impacts surface water supplies. Hence, failure or delays of these rains can lead to significant socio-economic impacts. Diagnosing and interpreting interannual variability and long-term trends in seasonality, and analysing the physical driving mechanisms, requires a robust definition of African precipitation seasonality, applicable to both observational datasets and model simulations. Here we present a methodology for objectively determining the onset and cessation of multiple wet seasons across the whole of Africa. Compatibility with known physical drivers of African rainfall, consistency with indigenous methods, and generally strong agreement between satellite-based rainfall data sets confirm that the method is capturing the correct seasonal progression of African rainfall. Application of this method to observational datasets reveals that over East Africa cessation of the short rains is 5 days earlier in La Nina years, and the failure of the rains and subsequent humanitarian disaster is associated with shorter as well as weaker rainy seasons over this region. The method is used to examine the representation of the seasonality of African precipitation in CMIP5 model simulations. Overall, atmosphere-only and fully coupled CMIP5 historical simulations represent essential aspects of the seasonal cycle; patterns of seasonal progression of the rainy season are captured, for the most part mean model onset/ cessation dates agree with mean observational dates to within 18 days. However, unlike the atmosphere-only simulations, the coupled simulations do not capture the biannual regime over the southern West African coastline, linked to errors in Gulf of Guinea Sea Surface Temperature. Application to both observational and climate model datasets, and

  4. Tracheal Constriction In A Growing Dog

    OpenAIRE

    DeArmond, Christina; Niimura del Barrio, Maria Chie; Rosati, Tomasso; McAllister, Hester; Ryan, John

    2017-01-01

    A six-month-old castrated male German Shepherd/Husky cross was presented for investigation of a progressive dyspnoea and regurgitation. A circumferential cervical wound had been identified and closed following debridement by the primary care veterinarian when the dog was three months old. There was an extraluminal tracheal compression on radiographs. Surgical exploration revealed a plastic band tied and embedded in the dorsal musculature of the neck. The band had been increasingly constrictin...

  5. Growing media constituents determine the microbial nitrogen conversions in organic growing media for horticulture.

    Science.gov (United States)

    Grunert, Oliver; Reheul, Dirk; Van Labeke, Marie-Christine; Perneel, Maaike; Hernandez-Sanabria, Emma; Vlaeminck, Siegfried E; Boon, Nico

    2016-05-01

    Vegetables and fruits are an important part of a healthy food diet, however, the eco-sustainability of the production of these can still be significantly improved. European farmers and consumers spend an estimated €15.5 billion per year on inorganic fertilizers and the production of N-fertilizers results in a high carbon footprint. We investigated if fertilizer type and medium constituents determine microbial nitrogen conversions in organic growing media and can be used as a next step towards a more sustainable horticulture. We demonstrated that growing media constituents showed differences in urea hydrolysis, ammonia and nitrite oxidation and in carbon dioxide respiration rate. Interestingly, mixing of the growing media constituents resulted in a stimulation of the function of the microorganisms. The use of organic fertilizer resulted in an increase in amoA gene copy number by factor 100 compared to inorganic fertilizers. Our results support our hypothesis that the activity of the functional microbial community with respect to nitrogen turnover in an organic growing medium can be improved by selecting and mixing the appropriate growing media components with each other. These findings contribute to the understanding of the functional microbial community in growing media and its potential role towards a more responsible horticulture. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  6. Nurturing a growing field: Computers & Geosciences

    Science.gov (United States)

    Mariethoz, Gregoire; Pebesma, Edzer

    2017-10-01

    Computational issues are becoming increasingly critical for virtually all fields of geoscience. This includes the development of improved algorithms and models, strategies for implementing high-performance computing, or the management and visualization of the large datasets provided by an ever-growing number of environmental sensors. Such issues are central to scientific fields as diverse as geological modeling, Earth observation, geophysics or climatology, to name just a few. Related computational advances, across a range of geoscience disciplines, are the core focus of Computers & Geosciences, which is thus a truly multidisciplinary journal.

  7. How to Measure Social Progress?

    DEFF Research Database (Denmark)

    Greve, Bent

    2017-01-01

    A good society is the goal for social policy. Recent years have seen a growing awareness that gross domestic product (GDP) alone does not measure this. Happiness and well-being have increasingly been seen as elements that should influence welfare policies. This review article provides an overview...... of many of the ways to measure well-being and happiness. It attempts to cover three distinct, but interrelated subjects. First, why and what can be used to complement GDP as measures for societal development. Second, is there a relation between well-being, happiness and central social policy areas? Third...... or not there is social progress. Lastly, by using the classical depiction of welfare states, the article analyses whether the indexes are in line herewith, and that, therefore, they might be used as an instrument for steering societies in the direction of a good society....

  8. Seasonal phenology and species composition of the aphid fauna in a northern crop production area.

    Directory of Open Access Journals (Sweden)

    Sascha M Kirchner

    Full Text Available BACKGROUND: The species diversity of aphids and seasonal timing of their flight activity can have significant impacts on crop production, as aphid species differ in their ability to transmit plant viruses and flight timing affects virus epidemiology. The aim of the study was to characterise the species composition and phenology of aphid fauna in Finland in one of the northernmost intensive crop production areas of the world (latitude 64°. METHODOLOGY/PRINCIPAL FINDINGS: Flight activity was monitored in four growing seasons (2007-010 using yellow pan traps (YPTs placed in 4-8 seed potato fields and a Rothamsted suction trap. A total of 58,528 winged aphids were obtained, identified to 83 taxa based on morphology, and 34 species were additionally characterised by DNA barcoding. Seasonal flight activity patterns analysed based on YPT catch fell into three main phenology clusters. Monoecious taxa showed early or middle-season flight activity and belonged to species living on shrubs/trees or herbaceous plants, respectively. Heteroecious taxa occurred over the entire potato growing season (ca. 90 days. Abundance of aphids followed a clear 3-year cycle based on suction trap data covering a decade. Rhopalosiphum padi occurring at the end of the potato growing season was the most abundant species. The flight activity of Aphis fabae, the main vector of Potato virus Y in the region, and Aphis gossypii peaked in the beginning of potato growing season. CONCLUSIONS/SIGNIFICANCE: Detailed information was obtained on phenology of a large number aphid species, of which many are agriculturally important pests acting as vectors of plant viruses. Aphis gossypii is known as a pest in greenhouses, but our study shows that it occurs also in the field, even far in the north. The novel information on aphid phenology and ecology has wide implications for prospective pest management, particularly in light of climate change.

  9. Effect of growing plants on denitrification at high soil nitrate concentrations

    International Nuclear Information System (INIS)

    Haider, K.; Mosier, A.; Heinemeyer, O.

    1987-01-01

    The availability of plant rhizosphere C deposits and its influence on microbial denitrification is not clearly defined. Conflicting reports as to the influence of plants and root exudation on denitrification continue to appear in the literature. The results of the authors earlier phytotron study indicated that denitrification was not stimulated in soils planted with corn or wheat compared to unplanted soils. Lower nitrate concentrations in the planted soils, however, may have led to misinterpretation of this data. A second study was conducted, to evaluate the effect of actively growing plants on denitrification where the NO 3 7 content of planted soils was maintained similar to unplanted soils. Simultaneously the C fixed by corn (Zea mays) and the fate of fertilizer N applied to the soil during the growing season were quantified. The corn was grown in a phytotron under a continuous supply of 14 CO 2 in 15 N fertilized soils to which 15 N-NO 3 - was added periodically during the growing season. The results of these studies showed that denitrification was not stimulated in soils planted with corn during active plant growth phase even when soil NO 3 - was relatively high. Denitrification was, however, greater in corn planted than unplanted soil when the recoverable root biomass began to decrease. Less N was immobilized and net 15 N immobilization was lower in planted soils than in unplanted soils. As denitrification was lower in planted soils during the time of active plant growth, the study suggests that root exudates did not stimulate either process

  10. 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.

  11. Seasonality processes in deciduous fruit plants

    Energy Technology Data Exchange (ETDEWEB)

    Carini, F.; Fortunati, P.; Brambilla, M. [Universita Cattolica del Sacro Cuore, Faculty of Agricultural Sciences, Institute of Agricultural and Environmental Chemistry, Piacenza (Italy)

    2004-07-01

    The understanding of the processes that affect the behaviour of radionuclides in crops can both improve the assessment of the risk to man from ingestion of contaminated food and support policy makers to take actions in order to protect environment and to safeguard human health. Even if in the last years various studies have been carried out on fruits, this field is still affected by large uncertainty, due to the lack of knowledge and poor understanding of processes. Among the factors that affect the fruit contamination at harvest, seasonality, i.e. the time of the year when the deposition occurs, has not been object of proper attention. In the present paper the processes at short term of {sup 134}Cs and {sup 85}Sr in fruit plants, following deposition at different growing stages, have been studied. More in particular, results from a three-annual research on fruit plants - strawberry and blackberry - contaminated via leaves or via soil are used to discuss the relative contribution of the different processes - interception, absorption, translocation, remobilization, loss - to seasonality. The process of leaf-to-fruit translocation is controlled by the metabolic activity of the plant. The highest contamination for the elements mobile in the phloem occurs when the process of translocation prevails, while that for the non mobile elements occurs when the process of direct deposition prevails. The residual activity in the plant depends on the stage of plant growth. At anthesis it is lower for {sup 134}Cs than for {sup 85}Sr, but not during ripening and pre-dormancy. The removal of radioactivity from leaves is lower during dormancy than in Spring or Summer, but a large percentage of radioactivity is lost with the dead leaves at the end of Winter. (author)

  12. The U2U Corn Growing Degree Day tool: Tracking corn growth across the US Corn Belt

    Directory of Open Access Journals (Sweden)

    James R. Angel

    2017-01-01

    Full Text Available The Corn Growing Degree Day (Corn GDD tool is a web-based product that can provide decision support on a variety of issues throughout the entire growing season by integrating current conditions, historical climate data, and projections of Corn GDD through the end of the growing season based on both National Weather Service computer model forecasts and climatology. The Corn GDD tool can help agricultural producers make a variety of important decisions before and during the growing season. This support can include: assessing the risk of early and late frosts and freezes that can cause crop damage; comparing corn hybrid maturity requirements and Corn GDD projections to select seed varieties and plan activities such as spraying; guiding marketing decisions based on historical and projected Corn GDDs when considering forward crop pricing (i.e., futures market. The Corn GDD tool provides decision support for corn producers in the central U.S. corn-producing states. Survey results, web statistics, and user feedback indicate that this tool is being actively used by decision makers.

  13. Within-season variation in sexual selection in a fish with dynamic sex roles.

    Science.gov (United States)

    Wacker, Sebastian; Amundsen, Trond; Forsgren, Elisabet; Mobley, Kenyon B

    2014-07-01

    The strength of sexual selection may vary between species, among populations and within populations over time. While there is growing evidence that sexual selection may vary between years, less is known about variation in sexual selection within a season. Here, we investigate within-season variation in sexual selection in male two-spotted gobies (Gobiusculus flavescens). This marine fish experiences a seasonal change in the operational sex ratio from male- to female-biased, resulting in a dramatic decrease in male mating competition over the breeding season. We therefore expected stronger sexual selection on males early in the season. We sampled nests and nest-holding males early and late in the breeding season and used microsatellite markers to determine male mating and reproductive success. We first analysed sexual selection associated with the acquisition of nests by comparing nest-holding males to population samples. Among nest-holders, we calculated the potential strength of sexual selection and selection on phenotypic traits. We found remarkable within-season variation in sexual selection. Selection on male body size related to nest acquisition changed from positive to negative over the season. The opportunity for sexual selection among nest-holders was significantly greater early in the season rather than late in the season, partly due to more unmated males. Overall, our study documents a within-season change in sexual selection that corresponds with a predictable change in the operational sex ratio. We suggest that many species may experience within-season changes in sexual selection and that such dynamics are important for understanding how sexual selection operates in the wild. © 2014 John Wiley & Sons Ltd.

  14. Seasonal Thermal Energy Storage Program

    Science.gov (United States)

    Minor, J. E.

    1980-01-01

    The Seasonal Thermal Energy Storage (STES) Program designed to demonstrate the storage and retrieval of energy on a seasonal basis using heat or cold available from waste or other sources during a surplus period is described. Factors considered include reduction of peak period demand and electric utility load problems and establishment of favorable economics for district heating and cooling systems for commercialization of the technology. The initial thrust of the STES Program toward utilization of ground water systems (aquifers) for thermal energy storage is emphasized.

  15. Management of Infections with Rapidly Growing

    Directory of Open Access Journals (Sweden)

    Jong Hwan Kim

    2012-01-01

    Full Text Available Background Infection caused by rapidly growing mycobacteria (RGM is not uncommon, andthe prevalence of RGM infection has been increasing. Clinical diagnosis is difficult becausethere are no characteristic clinical features. There is also no standard antibiotic regimenfor treating RGM infection. A small series of patients with RGM infections was studied toexamine their treatments and outcomes.Methods A total of 5 patients who had developed postoperative infections from January2009 to December 2010 were retrospectively reviewed. Patients were initially screened using amycobacteria rapid screening test (polymerase chain reaction [PCR]-reverse blot hybridizationassay. To confirm mycobacterial infection, specimens were cultured for nontuberculousmycobacteria and analyzed by 16 S ribosomal RNA and rpoB gene PCR.Results The patients were treated with intravenous antibiotics during hospitalization,and oral antibiotics were administered after discharge. The mean duration of follow-upwas 9 months, and all patients were completely cured of infection with a regimen of acombination of antibiotics plus surgical treatment. Although none of the patients developedrecurrence, there were complications at the site of infection, including hypertrophic scarring,pigmentation, and disfigurement.Conclusions Combination antibiotic therapy plus drainage of surgical abscesses appeared tobe effective for the RGM infections seen in our patients. Although neither the exact dosagenor a standardized regimen has been firmly established, we propose that our treatment canprovide an option for the management of rapidly growing mycobacterial infection.

  16. Immunotoxicity of ochratoxin A to growing gilts.

    Science.gov (United States)

    Harvey, R B; Elissalde, M H; Kubena, L F; Weaver, E A; Corrier, D E; Clement, B A

    1992-10-01

    Ochratoxin A (OA) was incorporated in the diets of growing gilts (mean body weight, 20.1 kg) at a concentration of 2.5 mg of OA/kg of feed and was fed continuously for 35 days. Humoral and cell-mediated immunologic measurements were evaluated to determine the effects of OA on immune function in swine. Cutaneous basophil hypersensitivity to phytohemagglutinin (PHA), delayed hypersensitivity to tuberculin, PHA-induced lymphocyte blastogenesis, interleukin-2 production, total and isotype immunoglobulin concentrations, antibody response to chicken RBC, and macrophage activation were used to evaluate immune function. Gilts treated with OA had reduced cutaneous basophil hypersensitivity response to PHA, reduced delayed hypersensitivity to tuberculin, decreased stimulation index for lymphoblastogenesis, decreased interleukin-2 production when lymphocytes were stimulated with concanavalin A, and decreased number and phagocytic activity of macrophages. Differences were not observed for total and isotype immunoglobulin concentrations, or humoral hemagglutination (chicken RBC) titer. These data indicate that OA may suppress cell-mediated immune response in growing swine.

  17. Light colour preference of growing rabbits

    Directory of Open Access Journals (Sweden)

    Zsolt Szendrő

    2010-01-01

    Full Text Available The objective of the experiment was to evaluate the light colour preference of growing rabbits placed in a free-choice cage. The experiment was carried out on 128 Pannon White growing rabbits weaned at the age of 5 weeks and placed into blocks (2m2 of four cages. The rabbits could move freely among the four cages (0.5m2 each through swing doors. The cages differed only in the colour of the light applied (white, yellow, green or blue. The lighting schedule was 16L: 8D. From 6 until 10 weeks of age, infrared video recording was performed once a week (24 hours. The number of rabbits in each cage was counted every 15 minutes. Feed consumption was measured weekly. Between 6 and 10 weeks of age the rabbits significantly preferred white light (28.0%. The preference order was the following: yellow (26.3%, blue (23.4% and green (22.3% (P<0.001. No significant differences were recorded in the feed consumption among the cages. In conclusion, the cage preference of the rabbits was slightly affected by the light colour.

  18. On the mechanics of growing thin biological membranes

    Science.gov (United States)

    Rausch, Manuel K.; Kuhl, Ellen

    2014-02-01

    Despite their seemingly delicate appearance, thin biological membranes fulfill various crucial roles in the human body and can sustain substantial mechanical loads. Unlike engineering structures, biological membranes are able to grow and adapt to changes in their mechanical environment. Finite element modeling of biological growth holds the potential to better understand the interplay of membrane form and function and to reliably predict the effects of disease or medical intervention. However, standard continuum elements typically fail to represent thin biological membranes efficiently, accurately, and robustly. Moreover, continuum models are typically cumbersome to generate from surface-based medical imaging data. Here we propose a computational model for finite membrane growth using a classical midsurface representation compatible with standard shell elements. By assuming elastic incompressibility and membrane-only growth, the model a priori satisfies the zero-normal stress condition. To demonstrate its modular nature, we implement the membrane growth model into the general-purpose non-linear finite element package Abaqus/Standard using the concept of user subroutines. To probe efficiently and robustness, we simulate selected benchmark examples of growing biological membranes under different loading conditions. To demonstrate the clinical potential, we simulate the functional adaptation of a heart valve leaflet in ischemic cardiomyopathy. We believe that our novel approach will be widely applicable to simulate the adaptive chronic growth of thin biological structures including skin membranes, mucous membranes, fetal membranes, tympanic membranes, corneoscleral membranes, and heart valve membranes. Ultimately, our model can be used to identify diseased states, predict disease evolution, and guide the design of interventional or pharmaceutic therapies to arrest or revert disease progression.

  19. On the mechanics of growing thin biological membranes.

    Science.gov (United States)

    Rausch, Manuel K; Kuhl, Ellen

    2014-02-01

    Despite their seemingly delicate appearance, thin biological membranes fulfill various crucial roles in the human body and can sustain substantial mechanical loads. Unlike engineering structures, biological membranes are able to grow and adapt to changes in their mechanical environment. Finite element modeling of biological growth holds the potential to better understand the interplay of membrane form and function and to reliably predict the effects of disease or medical intervention. However, standard continuum elements typically fail to represent thin biological membranes efficiently, accurately, and robustly. Moreover, continuum models are typically cumbersome to generate from surface-based medical imaging data. Here we propose a computational model for finite membrane growth using a classical midsurface representation compatible with standard shell elements. By assuming elastic incompressibility and membrane-only growth, the model a priori satisfies the zero-normal stress condition. To demonstrate its modular nature, we implement the membrane growth model into the general-purpose non-linear finite element package Abaqus/Standard using the concept of user subroutines. To probe efficiently and robustness, we simulate selected benchmark examples of growing biological membranes under different loading conditions. To demonstrate the clinical potential, we simulate the functional adaptation of a heart valve leaflet in ischemic cardiomyopathy. We believe that our novel approach will be widely applicable to simulate the adaptive chronic growth of thin biological structures including skin membranes, mucous membranes, fetal membranes, tympanic membranes, corneoscleral membranes, and heart valve membranes. Ultimately, our model can be used to identify diseased states, predict disease evolution, and guide the design of interventional or pharmaceutic therapies to arrest or revert disease progression.

  20. Profitability of Eucalyptus growing in Busiro, Mpigi District, Uganda

    African Journals Online (AJOL)

    farmers to grow forest trees, farmers need to be assured that their investments in forest tree growing is worthwhile. The paper examines the worthiness of investments in eucalyptus growing with the view of advising farmers on forest tree growing using .... When this material of planting stock, tending operations, and spacing.

  1. Seasonal variation in phytotoxicity of bracken (Pteridium aquilinum L. Kuhn).

    Science.gov (United States)

    Dolling, A; Zackrisson, O; Nilsson, M C

    1994-12-01

    Laboratory bioassays were used to test for the phytotoxicity of volatile compounds, fresh plant material as a seed bed, and water extracts from bracken [Pteridium aquilinum (L.) Kuhn] pinnules to germination and seedling growth of aspen (Populus tremula L.) and Scots pine (Pinus sylvestris L.). Fronds were sampled from two bracken populations, one in the south and one in the north of Sweden. All three bioassays showed inhibitory effects, and these varied seasonally with the most inhibitory effects occurring in May, June, and September. The peak of inhibition in May and June coincides with the start of the growing season when bracken still is immature and vulnerable to interference from other species. The increase in inhibitory effects in September appears to be due to transformation of natural products or an accumulation of inhibitory compounds that are released during decomposition following frond death. Addition of activated carbon did not remove the inhibitory effects.

  2. Off-season uptake of nitrogen in temperate heath vegetation

    DEFF Research Database (Denmark)

    Andresen, Louise Christoffersen; Michelsen, Anders

    2004-01-01

    study we show that northern temperate coastal heath vegetation has a significant uptake potential for nitrogen, both in the form of ammonium and as glycine, throughout the non-growing season. We used 15N ammonium and 2*(13C)15N glycine as nutrient tracer. This was injected into the soil two times during...... winter and once at spring. The winter temperatures were similar to those of average winter in the northern temperate region of Europe, with only few days of soil temperatures below zero and a winter mean of 2.4 °C. The vegetation, consisting of the evergreen dwarf shrub Calluna vulgaris (L...... uptake can cause increasing nitrogen concentration in shoot tissue from fall to spring. To our knowledge this is one of the first studies of plant nitrogen uptake during nongrowing season at a temperate heath. Our results show that the nitrogen uptake is in the same order of magnitude as summer uptake...

  3. SEASONAL VARIATIONS DETERMINE DIET QUALITYTOR

    African Journals Online (AJOL)

    3 Department of Biology, BahirDar Teachers' College. PO Box 79, Bahir Dar, Ethiopia. ABSTRACT; The diet composition and its use by Oreochromis niloticus in. Lake Tana, Ethiopia, were studied from monthly samples taken over 13 months. The composition of the diet varied seasonally, with dramatic increases in quality.

  4. ADHD, circadian rhythms and seasonality

    NARCIS (Netherlands)

    Wynchank, Dora S.; Bijlenga, Denise; Lamers, Femke; Bron, Tannetje I.; Winthorst, Wim H.; Vogel, Suzan W.; Penninx, Brenda W.; Beekman, Aartjan T.; Kooij, J. Sandra

    2016-01-01

    Objective: We evaluated whether the association between Adult Attention-Deficit/Hyperactivity Disorder (ADHD) and Seasonal Affective Disorder (SAD) was mediated by the circadian rhythm. Method: Data of 2239 persons from the Netherlands Study of Depression and Anxiety (NESDA) were used. Two groups

  5. Seasonal variation in pediatric dermatoses

    Directory of Open Access Journals (Sweden)

    Banerjee Sabyasachi

    2010-01-01

    Full Text Available Introduction: The under-five population is a unique and vulnerable component of our society that always demands special attention. Aims: Our present work aimed to study the seasonal variation, age-wise variation and distribution of lesions of common dermatoses of this age group. Materials and Methods: We clinically studied all fresh cases attending the skin OPD of our hospital for one month each from summer, rainy season and winter. Total number of patients was 879. Results: The top six skin diseases in our study were impetigo, miliaria, scabies, furunculosis, seborrheic dermatitis and papular urticaria. On statistical analysis, scabies and seborrheic dermatitis were more prevalent during winter while impetigo, furunculosis and miliaria were more during summer and rainy season. Papular urticaria was more frequent in the rainy season. Seborrheic dermatitis predominantly affected the infants while impetigo, furunculosis, miliaria and popular urticaria were commoner in older age groups. Conclusion: Distribution of lesions of common dermatoses will help diagnose difficult cases and extensive evaluation of the body parts which, by virtue of being commonly affected, are must-examine sites in under-five children.

  6. Seasonality of cardiovascular risk factors

    DEFF Research Database (Denmark)

    Marti-Soler, Helena; Gubelmann, Cédric; Aeschbacher, Stefanie

    2014-01-01

    OBJECTIVE: To assess the seasonality of cardiovascular risk factors (CVRF) in a large set of population-based studies. METHODS: Cross-sectional data from 24 population-based studies from 15 countries, with a total sample size of 237 979 subjects. CVRFs included Body Mass Index (BMI) and waist...

  7. Seasonal changes in the altitudinal distribution of nocturnally migrating birds during autumn migration.

    Science.gov (United States)

    La Sorte, Frank A; Hochachka, Wesley M; Farnsworth, Andrew; Sheldon, Daniel; Van Doren, Benjamin M; Fink, Daniel; Kelling, Steve

    2015-12-01

    Wind plays a significant role in the flight altitudes selected by nocturnally migrating birds. At mid-latitudes in the Northern Hemisphere, atmospheric conditions are dictated by the polar-front jet stream, whose amplitude increases in the autumn. One consequence for migratory birds is that the region's prevailing westerly winds become progressively stronger at higher migration altitudes. We expect this seasonality in wind speed to result in migrants occupying progressively lower flight altitudes, which we test using density estimates of nocturnal migrants at 100 m altitudinal intervals from 12 weather surveillance radar stations located in the northeastern USA. Contrary to our expectations, median migration altitudes deviated little across the season, and the variance was lower during the middle of the season and higher during the beginning and especially the end of the season. Early-season migrants included small- to intermediate-sized long-distance migrants in the orders Charadriiformes and Passeriformes, and late-season migrants included large-bodied and intermediate-distance migrants in the order Anseriformes. Therefore, seasonality in the composition of migratory species, and related variation in migration strategies and behaviours, resulted in a convex-concave bounded distribution of migration altitudes. Our results provide a basis for assessing the implications for migratory bird populations of changes in mid-latitude atmospheric conditions probably occurring under global climate change.

  8. Morphogenesis of filaments growing in flexible confinements

    Science.gov (United States)

    Vetter, R.; Wittel, F. K.; Herrmann, H. J.

    2014-07-01

    Space-saving design is a requirement that is encountered in biological systems and the development of modern technological devices alike. Many living organisms dynamically pack their polymer chains, filaments or membranes inside deformable vesicles or soft tissue-like cell walls, chorions and buds. Surprisingly little is known about morphogenesis due to growth in flexible confinements—perhaps owing to the daunting complexity lying in the nonlinear feedback between packed material and expandable cavity. Here we show by experiments and simulations how geometric and material properties lead to a plethora of morphologies when elastic filaments are growing far beyond the equilibrium size of a flexible thin sheet they are confined in. Depending on friction, sheet flexibility and thickness, we identify four distinct morphological phases emerging from bifurcation and present the corresponding phase diagram. Four order parameters quantifying the transitions between these phases are proposed.

  9. THE FASTEST GROWING LEAST DEVELOPED COUNTRIES

    Directory of Open Access Journals (Sweden)

    Wioletta NOWAK

    2017-12-01

    Full Text Available The paper presents trends in economic growth and development in twelve least developed countries from 2006 to 2015. The study is based on the data retrieved from the World Bank Database. During the analysed 10 years, seven Asian (Myanmar, Lao PDR, Bhutan, Cambodia, Timor-Leste, Bangladesh, and Afghanistan and five African (Ethiopia, Rwanda, Angola, Sudan, and Mozambique LDCs had average annual GDP per capita growth rates higher than 4.0%. GDP has been largely generated through the services and industry sectors. A few LDCs sustained strong growth mainly because of foreign assistance and in other countries remittances were a significant source of development finance. Resource rich countries recorded high inflows of foreign direct investment. In a few fast growing LDCs the state has been heavily engaged in economy. The analysed LDCs substantially improved their development indicators.

  10. Childhood Obesity: Review of a growing Problem.

    Science.gov (United States)

    Shivpuri, Anubhav; Shivpuri, Abhay; Sharma, Sunil

    2012-09-01

    The consequences of obesity in adulthood are well known. Obesity has a direct influence on mortality and acts as a risk factor for various diseases and health problems. It is associated with nonfatal but debilitating illnesses, such as respiratory difficulties, musculoskeletal disorders, skin problems and infertility. The association with fatal chronic diseases includes cardiovascular diseases, conditions related to insulin resistance and noninsulin-dependent diabetes. There has been a marked increase in the number of obese children coming for treatment to dentists, thus it is the moral responsibility of the dentists to educate both the patient and the parents of the problems of obesity and its control. A dentist may actually be the first person to inform the patient about this problem thus, a basic knowledge about it is important. How to cite this article: Shivpuri A, Shivpuri A, Sharma S. Childhood Obesity: Review of a growing Problem. Int J Clin Pediatr Dent 2012;5(3):237-241.

  11. Growing the Nuclear Workforce Through Outreach

    Science.gov (United States)

    Kilburn, Micha

    2015-10-01

    Many students don't encounter physics in the classroom until college or the end of high school. Most college students never encounter nuclear physics in the classroom. In order to grow the nuclear science workforce, students need to be aware of the field much earlier in the education. However, teaching teens about nuclear science can be a daunting task at the outset. I will present and describe successful outreach curricula and programs that can be duplicated by any college, university or laboratory. These include workshops for boy scouts and girl scouts as well as teaching nuclear science with magnetic marbles. I will also present some results from assessments of JINA-CEE's more intensive programs aimed at recruiting youth to the field. JINA-CEE

  12. What season suits you best? Seasonal light changes and cyanobacterial competition

    Directory of Open Access Journals (Sweden)

    G. Cascallares

    2015-05-01

    Full Text Available Nearly all living organisms, including some bacterial species, exhibit biological processes with a period of about 24 h called circadian (from the Latin circa, about and dies, day rhythms. These rhythms allow living organisms to anticipate the daily alternation of light and darkness. Experiments carried out in cyanobacteria have shown the adaptive value of circadian clocks. In theseexperiments, a wild type cyanobacterial strain (with a 24 h circadian rhythm and a mutantstrain (with a longer or shorter period grow in competition. In different experiments, the external light dark cycle was chosen to match the circadian period of the different strains, revealing that the strain whose circadian period matches the light-dark cycle has a larger fitness. As a consequence, the initial population of one strain grows while the other decays. These experiments were made under fixed light and dark intervals. In Nature, however, this relationship changes according to the season. Therefore, seasonalchanges in light could affect the results of the competition. Using a theoretical model, we analyze how modulation of light can change the survival of the different cyanobacterial strains. Our results show that there is a clear shift in the competition due to the modulation of light, which could be verified experimentally. Received: 20 Novembre 2014, Accepted: 29 March 2015; Edited by: C. A. Condat, G. J. Sibona; DOI: http://dx.doi.org/10.4279/PIP.070005 Cite as: G Cascallares, P M Gleiser, Papers in Physics 7, 070005 (2015

  13. Atmospheric modelling and prediction at time scales from days to seasons

    CSIR Research Space (South Africa)

    Landman, WA

    2010-09-01

    Full Text Available . There is a growing trend internationally towards the development of operational prediction systems that will bridge the gap between initial-value problem-based weather forecasts and boundary-value problem-based seasonal forecasts. One of the ways to bridge...

  14. Seasonal Biennial Burning and Woody Plant Control Influence Native Vegetation in Loblolly Pine Stands

    Science.gov (United States)

    James D. Haywood; Alton Martin; Henry A. Pearson; Harold E. Grelen

    1998-01-01

    This paper documents the results of a study to determine the effects of selectedvegetation-management treatments in loblolly pine. Vegetation in precommercially thinned, 6-year-old stands was subjected to five biennial growing season burns in either early March, May, or July coupled with hand felling of residual woody stems. Using a randomized complete block design, we...

  15. Seasonal and topographic effects on estimating fire severity from Landsat TM/ETM+data.

    Science.gov (United States)

    D.L. Verbyla; E.S. Kasischke; E.E. Hoy

    2008-01-01

    The maximum solar elevation is typically less than 50 degrees in the Alaskan boreal region and solar elevation varies substantially during the growing season. Because of the relatively low solar elevation at boreal latitudes, the effect of topography on spectral reflectance can influence fire severity indices derived from remotely sensed data. We used Landsat Thematic...

  16. Managing cool-season weeds in sugarbeet grown for biofuel in the Southeastern U.S.

    Science.gov (United States)

    Sugarbeet, grown for biofuel, is being considered as an alternate cool-season crop in the southeastern U. S. coastal plain. Typically, the crop would be seeded in the autumn, grow through the winter, and harvested the following spring. Labels for herbicides registered for use on sugarbeet grown in ...

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

    Science.gov (United States)

    Jessica Robin; Ralph Dubayah; Elena Sparrow; Elissa Levine

    2008-01-01

    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....

  18. Influence of growing conditions at different latitudes of Europe on strawberry growth performance, yield and quality

    DEFF Research Database (Denmark)

    Krüger, E.; Josuttis, M.; Nestby, R.

    2012-01-01

    . GDDs for individually tagged flowers increased notably from the first third to the last third of the developing period due to increasing temperature as the season proceeded. The fruit quality standards dry matter, soluble solids and titratable acidity were influenced by latitude giving northern sites...... harvest start. Duration of fruit development was negatively related to daily mean temperature and increased with higher latitude. 29–34 days were required from anthesis to harvest start for cv. Elsanta, 29–36 for cv. Korona and 27–38 for cv. Clery. Corresponding GDD values (growing degree days; 3°C base...

  19. Retrospective assessment of seasonal allergic symptoms

    DEFF Research Database (Denmark)

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

    2003-01-01

    BACKGROUND: 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...... 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...... reported lung symptoms (P assessment of seasonal allergic symptoms generally describes a shorter period than the arithmetic season. Post-season assessment tends to over-rate average symptom severity, but appears sufficiently sensitive to detect treatment efficacy....

  20. The Correlation between Thermal and Noxious Gas Environments, Pig Productivity and Behavioral Responses of Growing Pigs

    Directory of Open Access Journals (Sweden)

    Won Kyung Chang

    2011-08-01

    Full Text Available Correlations between environmental parameters (thermal range and noxious gas levels and the status (productivity, physiological, and behavioral of growing pigs were examined for the benefit of pig welfare and precision farming. The livestock experiment was conducted at a Seoul National University station in South Korea. Many variations were applied and the physiological and behavioral responses of the growing pigs were closely observed. Thermal and gas environment parameters were different during the summer and winter seasons, and the environments in the treatments were controlled in different manners. In the end, this study finds that factors such as Average Daily Gain (ADG, Adrenocorticotropic Hormone (ACTH, stress, posture, and eating habits were all affected by the controlled environmental parameters and that appropriate control of the foregoing could contribute to the improvement of precision farming and pig welfare.

  1. Seasonal Shifts in Diet and Gut Microbiota of the American Bison (Bison bison.

    Directory of Open Access Journals (Sweden)

    Gaddy T Bergmann

    Full Text Available North American bison (Bison bison are becoming increasingly important to both grassland management and commercial ranching. However, a lack of quantitative data on their diet constrains conservation efforts and the ability to predict bison effects on grasslands. In particular, we know little about the seasonality of the bison diet, the degree to which bison supplement their diet with eudicots, and how changes in diet influence gut microbial communities, all of which play important roles in ungulate performance. To address these knowledge gaps, we quantified seasonal patterns in bison diet and gut microbial community composition for a bison herd in Kansas using DNA sequencing-based analyses of both chloroplast and microbial DNA contained in fecal matter. Across the 11 sampling dates that spanned 166 days, we found that diet shifted continuously over the growing season, allowing bison to take advantage of the seasonal availability of high-protein plant species. Bison consumed more woody shrubs in spring and fall than in summer, when forb and grass intake predominated. In examining gut microbiota, the bacterial phylum Tenericutes shifted significantly in relative abundance over the growing season. This work suggests that North American bison can continuously adjust their diet with a high reliance on non-grasses throughout the year. In addition, we find evidence for seasonal patterns in gut community composition that are likely driven by the observed dietary changes.

  2. Progressive osseous heteroplasia

    African Journals Online (AJOL)

    Progressive osseous heteroplasia is a rare genetic disorder characterized by cu- taneous ossification during infancy and progressive ossification of subcutane- ous and deep connective tissue including muscle and fascia during childhood. It is at the severe end of a spectrum of Guanine Nucleotide-binding protein,.

  3. Environmental Growing Conditions in Five Production Systems Induce Stress Response and Affect Chemical Composition of Cocoa (Theobroma cacao L.) Beans.

    Science.gov (United States)

    Niether, Wiebke; Smit, Inga; Armengot, Laura; Schneider, Monika; Gerold, Gerhard; Pawelzik, Elke

    2017-11-29

    Cocoa beans are produced all across the humid tropics under different environmental conditions provided by the region but also by the season and the type of production system. Agroforestry systems compared to monocultures buffer climate extremes and therefore provide a less stressful environment for the understory cocoa, especially under seasonally varying conditions. We measured the element concentration as well as abiotic stress indicators (polyamines and total phenolic content) in beans derived from five different production systems comparing monocultures and agroforestry systems and from two harvesting seasons. Concentrations of N, Mg, S, Fe, Mn, Na, and Zn were higher in beans produced in agroforestry systems with high stem density and leaf area index. In the dry season, the N, Fe, and Cu concentration of the beans increased. The total phenolic content increased with proceeding of the dry season while other abiotic stress indicators like spermine decreased, implying an effect of the water availability on the chemical composition of the beans. Agroforestry systems did not buffer the variability of stress indicators over the seasons compared to monocultures. The effect of environmental growing conditions on bean chemical composition was not strong but can contribute to variations in cocoa bean quality.

  4. [Normocalcemic primary hyperparathyroidism: a growing problem].

    Science.gov (United States)

    Martínez Díaz-Guerra, Guillermo; Guadalix Iglesias, Sonsoles; Hawkins Carranza, Federico

    2013-08-04

    Normocalcemic primary hyperparathyroidism is at present one of the most common reasons for consultation in bone metabolism units. It is characterized by increased levels of intact parathyroid hormone in the presence of normal serum calcium (total and ionized) in generally asymptomatic individuals. The differential diagnosis should be considered in all situations that occur with secondary hyperparathyroidism. Its natural history is not well known, and it does not always progress to hypercalcemia. As a recently recognized entity, there are still no specific recommendations for its management. In this review we discuss some aspects of this entity, emphasizing the importance of a proper laboratory diagnosis, assessing possible signs or symptoms associated such as kidney stones or osteoporosis, which can help the clinician to take a conservative or interventionist attitude. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  5. Rapid Growing Eosinophilic Granuloma in Skull after Minor Trauma.

    Science.gov (United States)

    Kim, Young-Ji; Jo, Kwang Wook

    2015-04-01

    The authors present a case of rapidly progressing eosinophilic granuloma (EG) of the skull without hemorrhage after minor trauma. A 6-year-old boy presented with a soft mass on the midline of his forehead. He had a surgery for EG 19 months ago. One month earlier, computed tomography (CT) and bone scans were performed to evaluate the possible recurrence of EG, and there was no evidence of recurrence in CT. However, a slightly increased uptake in the bone scan was noted on the midline of the forehead. A rapid growing mass developed in a new spot after a minor trauma 7 days before the patient arrived at the clinic. His physical examination was unremarkable, except for a non-tender, soft, and immobile mass. A plain skull X-ray and CT showed a lytic bony defect on the midline of the frontal bone. Magnetic resonance imaging showed a 1.4 cm sized enhancing mass. Surgical resection and cranioplasty were done. The role of trauma in the development of EG is unclear. However, our case suggests that minor trauma is an aggravating factor for EG formation. Careful observation with regular follow-up is necessary in patients with EG after minor trauma.

  6. Light Pollution: Outdoor lighting is a growing threat to astronomy.

    Science.gov (United States)

    Riegel, K W

    1973-03-30

    There have been major qualitative and quantitative changes in outdoor lighting technology in the last decade. The level of skylight caused by outdoor lighting systems is growing at a very high rate, about 20 percent per year nationwide. In addition, the spectral distribution of man-made light pollution may change in the next decade from one containing a few mercury lines to one containing dozens of lines and a significantly increased continuum level. Light pollution is presently damaging to some astronomical programs, and it is likely to become a major factor limiting progress in the next decade. Suitable sites in the United States for new dark sky observing facilities are very difficult to find. Some of the increase in outdoor illumination is due to the character of national growth and development. Some is due to promotional campaigns, in which questionable arguments involving public safety are presented. There are protective measures which might be adopted by the government; these would significantly aid observational astronomy, without compromising the legitimate outdoor lighting needs of society. Observatories should establish programs to routinely monitor sky brightness as a function of position, wavelength, and time. The astronomical community should establish a mechanism by which such programs can be supported and coordinated.

  7. Growing Youth Growing Food: How Vegetable Gardening Influences Young People's Food Consciousness and Eating Habits

    Science.gov (United States)

    Libman, Kimberly

    2007-01-01

    Much attention is currently being paid to rising rates of obesity, especially among youth. In this context, garden-based education can have a role in improving public health. A qualitative study conducted at the Brooklyn Botanic Garden (BBG) Children's Garden provides supporting evidence for the claim that growing vegetables can improve the…

  8. Wartime diet for growing bobwhite quail

    Science.gov (United States)

    Nestler, R.B.; Llewellyn, L.; Benner, M.

    1944-01-01

    Two experiments, using 784 bobwhite quail chicks, were conducted at the Patuxent Research Refuge, Bowie, Maryland, to find a growing diet that would meet wartime restrictions. In 1941 a diet containing 14 per cent sardine fish meal was formulated and gave satisfactory results from the standpoints of survival and growth. Since fish meal now is scarce, search was made for a diet without war-restricted commodities yet equal to the above-mentioned diet in feeding value. Ten diets were compared.....In the present experiments, quail fed this same diet modified by the substitution of 0.12 per cent of D-activated sterol for vitamin A and D feeding oil fortified showed the highest survival and the best live weights at the end of both the sixth and tenth weeks. They also were among the top three groups in requiring the least quantity of feed per unit of gain in weight; however, they consumed the greatest quantity of feed.....Of the other nine diets, that which seemed most promising, considering survival, live weight, and efficiency of feed utilization, was as follows (parts by weight) : Yellow corn, ground 26.08...Millet, ground 10.00...Alfalfa leaf meal, dehydrated 7.50...Soybean oil meal, solvent-processed 50.00...Dried whey 3.00...Special steamed bonemeal 1.50...Limestone, ground 0.80...Salt mixture 1.OO...D-activated animal sterol 0.12....100.00.....At the end of ten weeks the results on this diet (Diet l l ) , as compared with that containing sardine meal (Diet 23), were as follows: Diet No. 11 Percentage survival 71, Average live weight per bird, grams 144,....Growing mash consumed, per bird-day, grams 6.8 Feed consumed per gram of gain in weight (grams) 3.8......Diet 23....Percentage survival, 80,...Avg live weight per bird, grams....145,....Growing mash consumed , per bird-day, grams...7.4...Feed consumed per gram of gain in weight (grams)....3.9. Results were unsatisfactory when expeller-processed soybean oil meal was used in this diet to replace solvent

  9. Seasonal variation in the stable isotopic composition of precipitation in the tropical montane forests of Monteverde, Costa Rica

    Science.gov (United States)

    Rhodes, Amy L.; Guswa, Andrew J.; Newell, Silvia E.

    2006-11-01

    Climate and land use change may diminish orographic clouds over tropical montane forests, stressing biota and water resources during dry seasons. From 2003 to 2005 we measured the stable isotopic composition of precipitation and throughfall in Monteverde, Costa Rica, to distinguish convective, wet season rainfall associated with the Intertropical Convergence Zone (ITCZ) from dry season, orographic rain produced by northeasterly trade winds. While event-to-event fluctuations of δ18O and δ2H are high, monthly samples reveal a seasonal signal that may be used to trace water through the hydrologic cycle. Deuterium excess indicates that water evaporated from land is an important flux to the region during the transitional and dry seasons when winds from the Caribbean slope dominate. Following the shift to convective rainfall at the start of the wet season, when the western equatorial winds influence the Pacific slope of Costa Rica, d excess values become depressed. Yet as the wet season progresses, d excess begins to climb. These data suggest that several months of rain are needed following an acute dry season on the northern Pacific slope before a terrestrial evaporative signal is detected in wet season precipitation. The evaporative flux may result from a wet season expansion of surface water bodies and flooding of seasonal wetlands.

  10. Climatic growing conditions of Jatropha curcas L.

    Energy Technology Data Exchange (ETDEWEB)

    Maes, W.H.; Achten, W.M.J.; Muys, B. [Katholieke Universiteit Leuven, Division Forest, Nature and Landscape, Celestijnenlaan 200 E Box 2411, BE-3001 Leuven (Belgium); Trabucco, A. [Katholieke Universiteit Leuven, Division Forest, Nature and Landscape, Celestijnenlaan 200 E Box 2411, BE-3001 Leuven (Belgium); International Water Management Institute (IWMI), P.O. Box 2075, Colombo (Sri Lanka)

    2009-10-15

    The massive investment in new jatropha plantations worldwide is not sufficiently based on a profound scientific knowledge of its ecology. In this article, we define the climatic conditions in its area of natural distribution by combining the locations of herbarium specimens with corresponding climatic information, and compare these conditions with those in 83 jatropha plantations worldwide. Most specimens (87%) were found in tropical savannah and monsoon climates (A{sub m}, A{sub w}) and in temperate climates without dry season and with hot summer (C{sub fa}), while very few were found in semi-arid (B{sub S}) and none in arid climates (B{sub W}). Ninety-five percent of the specimens grew in areas with a mean annual rainfall above 944 mm year{sup -1} and an average minimum temperature of the coldest month (T{sub min}) above 10.5 C. The mean annual temperature range was 19.3-27.2 C. The climatic conditions at the plantations were different from those of the natural distribution specimens for all studied climatic variables, except average maximum temperature in the warmest month. Roughly 40% of the plantations were situated in regions with a drier climate than in 95% of the area of the herbarium specimens, and 28% of the plantations were situated in areas with T{sub min} below 10.5 C. The observed precipitation preferences indicate that jatropha is not common in regions with arid and semi-arid climates. Plantations in arid and semi-arid areas hold the risk of low productivity or irrigation requirement. Plantations in regions with frost risk hold the risk of damage due to frost. (author)

  11. Greater deciduous shrub abundance extends tundra peak season and increases modeled net CO2 uptake.

    Science.gov (United States)

    Sweet, Shannan K; Griffin, Kevin L; Steltzer, Heidi; Gough, Laura; Boelman, Natalie T

    2015-06-01

    Satellite studies of the terrestrial Arctic report increased summer greening and longer overall growing and peak seasons since the 1980s, which increases productivity and the period of carbon uptake. These trends are attributed to increasing air temperatures and reduced snow cover duration in spring and fall. Concurrently, deciduous shrubs are becoming increasingly abundant in tundra landscapes, which may also impact canopy phenology and productivity. Our aim was to determine the influence of greater deciduous shrub abundance on tundra canopy phenology and subsequent impacts on net ecosystem carbon exchange (NEE) during the growing and peak seasons in the arctic foothills region of Alaska. We compared deciduous shrub-dominated and evergreen/graminoid-dominated community-level canopy phenology throughout the growing season using the normalized difference vegetation index (NDVI). We used a tundra plant-community-specific leaf area index (LAI) model to estimate LAI throughout the green season and a tundra-specific NEE model to estimate the impact of greater deciduous shrub abundance and associated shifts in both leaf area and canopy phenology on tundra carbon flux. We found that deciduous shrub canopies reached the onset of peak greenness 13 days earlier and the onset of senescence 3 days earlier compared to evergreen/graminoid canopies, resulting in a 10-day extension of the peak season. The combined effect of the longer peak season and greater leaf area of deciduous shrub canopies almost tripled the modeled net carbon uptake of deciduous shrub communities compared to evergreen/graminoid communities, while the longer peak season alone resulted in 84% greater carbon uptake in deciduous shrub communities. These results suggest that greater deciduous shrub abundance increases carbon uptake not only due to greater leaf area, but also due to an extension of the period of peak greenness, which extends the period of maximum carbon uptake. © 2015 John Wiley & Sons Ltd.

  12. Autoethnography in Health Research: Growing Pains?

    Science.gov (United States)

    Chang, Heewon

    2016-03-01

    Autoethnography is gaining acceptance as a legitimate research method in health science research. The growing volume of published autoethnographies is indicative of this trend. After discussing the methodological tenents of this qualitative research method and its compatibility with health-related research, the author illustrates this trend with examples of published autoethnogrpahic books, theses, and journal articles. While celebrating the potential of autoethnography as a suitable health research method, the author critiques dominatly descriptive and evocative illness self-narratives that may evoke emontionally compelling responses from readers but offer insufficient sociocultural insights about the illness phenomenon. To identify a "desirable" autoethnography that provides not only a "thick description" of personal experiences but also a sociocultural interpration of such experiences, the author recommends both creators and consumers of autoethnography to ask five evaluative questions: (1) Does the autoethnography use authentic and trustworthy data?; (2) Does the autoethnography follow a reliable research process and show the process clearly?; (3) Does the autoethnography follow ethical steps to protect the rights of self and others presented and implicated in the autoethnography?; (4) Does the autoethnography analyze and interpret the sociocultural meaning of the author's personal experiences?; and (5) Does the autoethnography attempt to make a scholarly contribution with its conclusion and engagement of the existing literature? © The Author(s) 2016.

  13. Growing markets to sustain oil sands development

    International Nuclear Information System (INIS)

    Wise, T.H.

    2003-01-01

    The utilization of Alberta bitumen for the clean fuels market depends on upgrading, transportation, and refining processes. Forecasts show that oil sands production, which includes synthetic crude oil (SCO), will surpass declining conventional production in Western Canada. Several issues pose a challenge to the oil sands processing industry. The producers' market is affected by crude oil prices, market expansion options, diluent availability/cost, supply cost competitiveness, and regional processing. The common market issues include light/heavy crude prices, oil sands crude qualities, prices of oil sands crudes, pipeline infrastructure, and competitive supplies. The issues facing the refiners are: refining margins, security of crude supply, refined product quality, and competitive product supply. A brief review of markets for Canadian crude oil, including synthetic crude, was provided. The share of the Midwest market by Alberta must be retained and increased. The market expansion options were reviewed for both downstream (refining) and upstream (upgrading) operations. To reach more distant markets such as Southern Midwest, Washington, and California, new pipeline capacity would be required. The market is nearly saturated for Canada's heavy oil supply. More upgrading will be required as bitumen production increases. Market growth is still possible for Canada's SCO but according to forecasts, the market could also become saturated. To increase demand and allow supplies to grow, SCO prices may fall below light crude prices. It was noted that a balance must be achieved in order for producers to increase production and for refiner/upgraders to expand their conversion capacity. tabs., figs

  14. CKD and poverty: a growing global challenge.

    Science.gov (United States)

    Hossain, Mohammed P; Goyder, Elizabeth C; Rigby, Jan E; El Nahas, Meguid

    2009-01-01

    Approximately 1.2 billion individuals worldwide live in extreme poverty (poverty (Poverty is most prevalent in developing countries, but does not spare richer economies, where huge income discrepancies have been reported. Poverty is a major health care marker affecting a number of chronic, communicable, and noncommunicable diseases. Poverty and social deprivation are known to affect the predisposition, diagnosis, and management of chronic diseases; they directly impact on the prevalence of such conditions as obesity, diabetes, and hypertension. Also, growing evidence links poverty to chronic kidney disease (CKD). This may be caused by a direct impact of poverty on CKD or indirectly through the increased health care burden linked to poverty-associated diabetes and hypertension. Furthermore, data have shown that the poor and socially deprived have a greater prevalence of end-stage renal disease. Access to renal care, dialysis, and transplantation may also be affected by social deprivation. Overall, poverty and social deprivation are emerging as major risk markers for CKD in both developing and developed countries. Their impact on CKD warrants careful analysis because it may confound the interpretation of CKD risk factors within communities. This review therefore aims to look at the evidence linking poverty to CKD and its major risk factors, namely, diabetes and hypertension.

  15. Selective sweeps in growing microbial colonies

    International Nuclear Information System (INIS)

    Korolev, Kirill S; Müller, Melanie J I; Murray, Andrew W; Nelson, David R; Karahan, Nilay; Hallatschek, Oskar

    2012-01-01

    Evolutionary experiments with microbes are a powerful tool to study mutations and natural selection. These experiments, however, are often limited to the well-mixed environments of a test tube or a chemostat. Since spatial organization can significantly affect evolutionary dynamics, the need is growing for evolutionary experiments in spatially structured environments. The surface of a Petri dish provides such an environment, but a more detailed understanding of microbial growth on Petri dishes is necessary to interpret such experiments. We formulate a simple deterministic reaction–diffusion model, which successfully predicts the spatial patterns created by two competing species during colony expansion. We also derive the shape of these patterns analytically without relying on microscopic details of the model. In particular, we find that the relative fitness of two microbial strains can be estimated from the logarithmic spirals created by selective sweeps. The theory is tested with strains of the budding yeast Saccharomyces cerevisiae for spatial competitions with different initial conditions and for a range of relative fitnesses. The reaction–diffusion model also connects the microscopic parameters like growth rates and diffusion constants with macroscopic spatial patterns and predicts the relationship between fitness in liquid cultures and on Petri dishes, which we confirmed experimentally. Spatial sector patterns therefore provide an alternative fitness assay to the commonly used liquid culture fitness assays. (paper)

  16. Popularity versus similarity in growing networks.

    Science.gov (United States)

    Papadopoulos, Fragkiskos; Kitsak, Maksim; Serrano, M Ángeles; Boguñá, Marián; Krioukov, Dmitri

    2012-09-27

    The principle that 'popularity is attractive' underlies preferential attachment, which is a common explanation for the emergence of scaling in growing networks. If new connections are made preferentially to more popular nodes, then the resulting distribution of the number of connections possessed by nodes follows power laws, as observed in many real networks. Preferential attachment has been directly validated for some real networks (including the Internet), and can be a consequence of different underlying processes based on node fitness, ranking, optimization, random walks or duplication. Here we show that popularity is just one dimension of attractiveness; another dimension is similarity. We develop a framework in which new connections optimize certain trade-offs between popularity and similarity, instead of simply preferring popular nodes. The framework has a geometric interpretation in which popularity preference emerges from local optimization. As opposed to preferential attachment, our optimization framework accurately describes the large-scale evolution of technological (the Internet), social (trust relationships between people) and biological (Escherichia coli metabolic) networks, predicting the probability of new links with high precision. The framework that we have developed can thus be used for predicting new links in evolving networks, and provides a different perspective on preferential attachment as an emergent phenomenon.

  17. Acoustic properties of low growing plants.

    Science.gov (United States)

    Horoshenkov, Kirill V; Khan, Amir; Benkreira, Hadj

    2013-05-01

    The plane wave normal incidence acoustic absorption coefficient of five types of low growing plants is measured in the presence and absence of soil. These plants are generally used in green living walls and flower beds. Two types of soil are considered in this work: a light-density, man-made soil and a heavy-density natural clay base soil. The absorption coefficient data are obtained in the frequency range of 50-1600 Hz using a standard impedance tube of diameter 100 mm. The equivalent fluid model for sound propagation in rigid frame porous media proposed by Miki [J. Acoust. Soc. Jpn. (E) 11, 25-28 (1990)] is used to predict the experimentally observed behavior of the absorption coefficient spectra of soils, plants, and their combinations. Optimization analysis is employed to deduce the effective flow resistivity and tortuosity of plants which are assumed to behave acoustically as an equivalent fluid in a rigid frame porous medium. It is shown that the leaf area density and dominant angle of leaf orientation are two key morphological characteristics which can be used to predict accurately the effective flow resistivity and tortuosity of plants.

  18. High-purity germanium crystal growing

    International Nuclear Information System (INIS)

    Hansen, W.L.; Haller, E.E.

    1982-10-01

    The germanium crystals used for the fabrication of nuclear radiation detectors are required to have a purity and crystalline perfection which is unsurpassed by any other solid material. These crystals should not have a net electrically active impurity concentration greater than 10 10 cm - 3 and be essentially free of charge trapping defects. Such perfect crystals of germanium can be grown only because of the highly favorable chemical and physical properties of this element. However, ten years of laboratory scale and commercial experience has still not made the production of such crystals routine. The origin and control of many impurities and electrically active defect complexes is now fairly well understood but regular production is often interrupted for long periods due to the difficulty of achieving the required high purity or to charge trapping in detectors made from crystals seemingly grown under the required conditions. The compromises involved in the selection of zone refining and crystal grower parts and ambients is discussed and the difficulty in controlling the purity of key elements in the process is emphasized. The consequences of growing in a hydrogen ambient are discussed in detail and it is shown how complexes of neutral defects produce electrically active centers

  19. Growing duckweed for biofuel production: a review.

    Science.gov (United States)

    Cui, W; Cheng, J J

    2015-01-01

    Duckweed can be utilised to produce ethanol, butanol and biogas, which are promising alternative energy sources to minimise dependence on limited crude oil and natural gas. The advantages of this aquatic plant include high rate of nutrient (nitrogen and phosphorus) uptake, high biomass yield and great potential as an alternative feedstock for the production of fuel ethanol, butanol and biogas. The objective of this article is to review the published research on growing duckweed for the production of the biofuels, especially starch enrichment in duckweed plants. There are mainly two processes affecting the accumulation of starch in duckweed biomass: photosynthesis for starch generation and metabolism-related starch consumption. The cost of stimulating photosynthesis is relatively high based on current technologies. Considerable research efforts have been made to inhibit starch degradation. Future research need in this area includes duckweed selection, optimisation of duckweed biomass production, enhancement of starch accumulation in duckweeds and use of duckweeds for production of various biofuels. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Turkey opens electricity markets as demand grows

    Energy Technology Data Exchange (ETDEWEB)

    McKeigue, J.; Da Cunha, A.; Severino, D. [Global Business Reports (United States)

    2009-06-15

    Turkey's growing power market has attracted investors and project developers for over a decade, yet their plans have been dashed by unexpected political or financial crises or, worse, obstructed by a lengthy bureaucratic approval process. Now, with a more transparent retail electricity market, government regulators and investors are bullish on Turkey. Is Turkey ready to turn the power on? This report closely examine Turkey's plans to create a power infrastructure capable of providing the reliable electricity supplies necessary for sustained economic growth. It was compiled with on-the-ground research and extensive interview with key industrial and political figures. Today, hard coal and lignite account for 21% of Turkey's electricity generation and gas-fired plants account for 50%. The Alfin Elbistan-B lignite-fired plant has attracted criticism for its lack of desulfurization units and ash dam facilities that have tarnished the industry's image. A 1,100 MW hard-coal fired plant using supercritical technology is under construction. 9 figs., 1 tab.