Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer.

Science.gov (United States)

Whiteman, John P; Harlow, Henry J; Durner, George M; Regehr, Eric V; Rourke, Bryan C; Robles, Manuel; Amstrup, Steven C; Ben-David, Merav

2017-01-01

When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other demographic groups) as well as summer (when sea ice retreats from key foraging habitats). We investigated muscle atrophy in samples of biceps femoris collected from free-ranging polar bears in the Southern Beaufort Sea (SBS) throughout their annual cycle. Atrophy was most pronounced in April-May as a result of food deprivation during the previous winter, with muscles exhibiting reduced protein concentration, increased water content, and lower creatine kinase mRNA. These animals increased feeding and activity in spring (when seal prey becomes more available), initiating a period of muscle recovery. During the following ice melt of late summer, ~30% of SBS bears abandon retreating sea ice for land; in August, these 'shore' bears exhibited no muscle atrophy, indicating that they had fully recovered from winter food deprivation. These individuals subsequently scavenged whale carcasses deposited by humans and by October, had retained good muscle condition. In contrast, ~70% of SBS bears follow the ice north in late summer, into deep water with less prey. These 'ice' bears fast; by October, they exhibited muscle protein loss and rapid changes in myosin heavy-chain isoforms in response to reduced activity. These findings indicate that, unlike other bears during winter hibernation, polar bears without food in summer cannot mitigate atrophy. Consequently, prolonged summer fasting resulting from climate change-induced ice loss creates a risk of greater muscle atrophy and reduced abilities to travel and hunt.

Effect of winter cold duration on spring phenology of the orange tip butterfly, Anthocharis cardamines.

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Stålhandske, Sandra; Lehmann, Philipp; Pruisscher, Peter; Leimar, Olof

2015-12-01

The effect of spring temperature on spring phenology is well understood in a wide range of taxa. However, studies on how winter conditions may affect spring phenology are underrepresented. Previous work on Anthocharis cardamines (orange tip butterfly) has shown population-specific reaction norms of spring development in relation to spring temperature and a speeding up of post-winter development with longer winter durations. In this experiment, we examined the effects of a greater and ecologically relevant range of winter durations on post-winter pupal development of A. cardamines of two populations from the United Kingdom and two from Sweden. By analyzing pupal weight loss and metabolic rate, we were able to separate the overall post-winter pupal development into diapause duration and post-diapause development. We found differences in the duration of cold needed to break diapause among populations, with the southern UK population requiring a shorter duration than the other populations. We also found that the overall post-winter pupal development time, following removal from winter cold, was negatively related to cold duration, through a combined effect of cold duration on diapause duration and on post-diapause development time. Longer cold durations also lead to higher population synchrony in hatching. For current winter durations in the field, the A. cardamines population of southern UK could have a reduced development rate and lower synchrony in emergence because of short winters. With future climate change, this might become an issue also for other populations. Differences in winter conditions in the field among these four populations are large enough to have driven local adaptation of characteristics controlling spring phenology in response to winter duration. The observed phenology of these populations depends on a combination of winter and spring temperatures; thus, both must be taken into account for accurate predictions of phenology.

Evaluation of nitrogen uptake patterns in spring and winter wheat in western Oregon

International Nuclear Information System (INIS)

Baloch, D.M.; Malghani, M.A.K.; Khan, M.A.; Kakar, E.

2010-01-01

An understanding of the ground nitrogen (N) uptake pattern for wheat (Triticum aestivum L.) is essential to facilitate nitrogen management. The purpose of this study was to determine the nitrogen uptake pattern of spring and winter wheat grown in western Oregon, USA. Data used in this study were obtained from three different trials. For spring wheat rotation trials five spring wheat cultivars were used. Fertilizer N (16-16-16-4) at the rate of 140 kg ha/sup -1/ was applied at the time of planting. In small plot rotation trials five fertilizer treatments - 0, 50, 100,150 and 200 kg N ha/sup -1/ were used. Rotations include winter wheat following clover and winter wheat following oat. The N uptake and dry matter yield of winter wheat were also determined from unfertilized plots of wheat trial. The maximum N uptake for spring wheat and winter wheat were at 1100 and 2000 accumulated growing degree days (GDD), before Feekes 10, respectively. The maximum N uptake rate for spring wheat, 0.038 kg N GDD/sup -1/, occurred at 750 GDD and the peak N uptake was observed approximately 35 days after Feekes 2. Nitrogen uptake in winter wheat was significantly affected by rotations. (author)

Occurrence of Rhynchosporium secalis (Oud. J.J. Davis on spring barley and winter rye in Finland

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Kaiho Mäkelä

1974-05-01

Full Text Available This study was carried out on Rhynchosprium secalis (Oud. J. J. Davis occurring on spring barley, winter rye and couch grass (Agropyron repens (L. PB in Finland. The results were obtained from samples of barley (c. 860 samples and rye (c. 200 samples gathered in fields during the growing season throughout the country in 1971 1973. The samples (c. 170 samples of Agropyron repens were collected in fields and the borders of fields. The fungi of all the samples were examined by microscope and cultures and inocolation tests were used as well. Rhynchosporium secalis was observed to occur commonly on spring barley throughout the country from Helsinki to Lapland. The fungus was observed in about 30 per cent of the fields and in below 60 percent of the localities examined. Leaf blotch was commoner on six rowed barley than on two-rowed barley. The fungus sometimes attacked a field in great profusion. R. secalis was observed in below 50 per cent of the winter rye samples and in below 70 per cent of the localities examined. The fungus occurred commonly in the southern part of Finland and was found also in Lapland (Inari, 69° N, 27°E. Spores of the fungus were most abundant in the leaves of rye in spring and in early summer. R. secalis was observed rather scarce (in over 10 per cent of fields and in over 25 per cent of the localities examined on Agropyron repens throughout the country. A high degree of host specialisation has been found within the species R. secalis. Two isolates from spring barley and from winter rye were pathogenic to their original host only.

The incidence of torpor in winter and summer in the Angolan free ...

African Journals Online (AJOL)

The incidence of torpor during summer and winter in response to cold exposure in Mops condylurus was studied in a subtropical environment. Body temperature changes under natural roosting conditions during winter and summer were monitored using bats fitted with temperature-sensitive radio transmitters.

Late Holocene anti-phase change in the East Asian summer and winter monsoons

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Kang, Shugang; Wang, Xulong; Roberts, Helen M.; Duller, Geoff A. T.; Cheng, Peng; Lu, Yanchou; An, Zhisheng

2018-05-01

Changes in East Asian summer and winter monsoon intensity have played a pivotal role in the prosperity and decline of society in the past, and will be important for future climate scenarios. However, the phasing of changes in the intensity of East Asian summer and winter monsoons on millennial and centennial timescales during the Holocene is unclear, limiting our ability to understand the factors driving past and future changes in the monsoon system. Here, we present a high resolution (up to multidecadal) loess record for the last 3.3 ka from the southern Chinese Loess Plateau that clearly demonstrates the relationship between changes in the intensity of the East Asian summer and winter monsoons, particularly at multicentennial scales. At multimillennial scales, the East Asian summer monsoon shows a steady weakening, while the East Asian winter monsoon intensifies continuously. At multicentennial scales, a prominent ∼700-800 yr cycle in the East Asian summer and winter monsoon intensity is observed, and here too the two monsoons are anti-phase. We conclude that multimillennial changes are driven by Northern Hemisphere summer insolation, while multicentennial changes can be correlated with solar activity and changing strength of the Atlantic meridional overturning circulation.

Winter climate controls soil carbon dynamics during summer in boreal forests

International Nuclear Information System (INIS)

Haei, Mahsa; Öquist, Mats G; Ilstedt, Ulrik; Laudon, Hjalmar; Kreyling, Juergen

2013-01-01

Boreal forests, characterized by distinct winter seasons, store a large proportion of the global terrestrial carbon (C) pool. We studied summer soil C-dynamics in a boreal forest in northern Sweden using a seven-year experimental manipulation of soil frost. We found that winter soil climate conditions play a major role in controlling the dissolution/mineralization of soil organic-C in the following summer season. Intensified soil frost led to significantly higher concentrations of dissolved organic carbon (DOC). Intensified soil frost also led to higher rates of basal heterotrophic CO 2 production in surface soil samples. However, frost-induced decline in the in situ soil CO 2 concentrations in summer suggests a substantial decline in root and/or plant associated rhizosphere CO 2 production, which overrides the effects of increased heterotrophic CO 2 production. Thus, colder winter soils, as a result of reduced snow cover, can substantially alter C-dynamics in boreal forests by reducing summer soil CO 2 efflux, and increasing DOC losses. (letter)

Daily steps are low year-round and dip lower in fall/winter: findings from a longitudinal diabetes cohort

Directory of Open Access Journals (Sweden)

Sigal Ron J

2010-11-01

Full Text Available Abstract Background Higher walking levels lead to lower mortality in type 2 diabetes, but inclement weather may reduce walking. In this patient population, we conducted a longitudinal cohort study to objectively quantify seasonal variations both in walking and in two vascular risk factors associated with activity levels, hemoglobin A1C and blood pressure. Methods Between June 2006 and July 2009, volunteer type 2 diabetes patients in Montreal, Quebec, Canada underwent two weeks of pedometer measurement up to four times over a one year follow-up period (i.e. once/season. Pedometer viewing windows were concealed (snap-on cover and tamper proof seal. A1C, blood pressure, and anthropometric parameters were also assessed. Given similarities in measures for spring/summer and fall/winter, and because not all participants completed four assessments, spring and summer values were collapsed as were fall and winter values. Mean within-individual differences (95% confidence intervals were computed for daily steps, A1C, and systolic and diastolic blood pressure, by subtracting spring/summer values from fall/winter values. Results Among 201 participants, 166 (82.6% underwent at least one fall/winter and one spring/summer evaluation. Approximately half were women, the mean age was 62.4 years (SD 10.8, and the mean BMI was 30.1 kg/m2 (SD 5.7. Step counts averaged at a sedentary level in fall/winter (mean 4,901 steps/day, SD 2,464 and at a low active level in spring/summer (mean 5,659 steps/day, SD 2,611. There was a -758 (95% CI: -1,037 to -479 mean fall/winter to spring/summer within-individual difference. There were no significant differences in A1C or in anthropometric parameters. Systolic blood pressure was higher in fall/winter (mean 137 mm Hg, SD 16 than spring/summer (133 mm Hg, SD 14 with a mean difference of 4.0 mm Hg (95% CI: 2.3 to 5.7. Conclusions Daily step counts in type 2 diabetes patients are low, dipping lower during fall/winter. In this

Meteorological conditions in a thinner Arctic sea ice regime from winter to summer during the Norwegian Young Sea Ice expedition (N-ICE2015)

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Cohen, Lana; Hudson, Stephen R.; Walden, Von P.; Graham, Robert M.; Granskog, Mats A.

2017-07-01

Atmospheric measurements were made over Arctic sea ice north of Svalbard from winter to early summer (January-June) 2015 during the Norwegian Young Sea Ice (N-ICE2015) expedition. These measurements, which are available publicly, represent a comprehensive meteorological data set covering the seasonal transition in the Arctic Basin over the new, thinner sea ice regime. Winter was characterized by a succession of storms that produced short-lived (less than 48 h) temperature increases of 20 to 30 K at the surface. These storms were driven by the hemispheric scale circulation pattern with a large meridional component of the polar jet stream steering North Atlantic storms into the high Arctic. Nonstorm periods during winter were characterized by strong surface temperature inversions due to strong radiative cooling ("radiatively clear state"). The strength and depth of these inversions were similar to those during the Surface Heat Budget of the Arctic Ocean (SHEBA) campaign. In contrast, atmospheric profiles during the "opaquely cloudy state" were different to those from SHEBA due to differences in the synoptic conditions and location within the ice pack. Storm events observed during spring/summer were the result of synoptic systems located in the Barents Sea and the Arctic Basin rather than passing directly over N-ICE2015. These synoptic systems were driven by a large-scale circulation pattern typical of recent years, with an Arctic Dipole pattern developing during June. Surface temperatures became near-constant 0°C on 1 June marking the beginning of summer. Atmospheric profiles during the spring and early summer show persistent lifted temperature and moisture inversions that are indicative of clouds and cloud processes.

Evening daylight may cause adolescents to sleep less in spring than in winter

Science.gov (United States)

Figueiro, Mariana G.; Rea, Mark S.

2012-01-01

Sleep restriction commonly experienced by adolescents can stem from greater sleep pressure by the homeostatic processes and from phase delays of the circadian system. With regard to the latter potential cause, we hypothesized that because there is more natural evening light during the spring than winter, a sample of adolescent students would be more phase delayed in spring than in winter, would have later sleep onset times and, because of fixed school schedules, would have shorter sleep durations. Sixteen eighth-grade subjects were recruited for the study. We collected sleep logs and saliva samples to determine their dim light melatonin onset (DLMO), a well-established circadian marker. Actual circadian light exposures experienced by a subset of twelve subjects over the course of seven days in winter and in spring using a personal, head-worn, circadian light measurement device are also reported here. Results showed that this sample of adolescents was exposed to significantly more circadian light in spring than in winter, especially in the evening hours when light exposure would likely delay circadian phase. Consistent with the light data, DLMO and sleep onset times were significantly more delayed, and sleep durations were significantly shorter in spring than in winter. The present ecological study of light, circadian phase, and self-reported sleep suggests that greater access to evening daylight in the spring may lead to sleep restriction in adolescents while attending school. Therefore, lighting schemes that reduce evening light in the spring may encourage longer sleep times in adolescents. PMID:20653452

Inter-Relationship Between Subtropical Pacific Sea Surface Temperature, Arctic Sea Ice Concentration, and the North Atlantic Oscillation in Recent Summers and Winters

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Lim, Young-Kwon; Cullather, Richard I.; Nowicki, Sophie M.; Kim, Kyu-Myong

2017-01-01

The inter-relationship between subtropical western-central Pacific sea surface temperatures (STWCPSST), sea ice concentration in the Beaufort Sea (SICBS), and the North Atlantic Oscillation (NAO) are investigated for the last 37 summers and winters (1980-2016). Lag-correlation of the STWCPSST×(-1) in spring with the NAO phase and SICBS in summer increases over the last two decades, reaching r = 0.4-0.5 with significance at 5 percent, while winter has strong correlations in approximately 1985-2005. Observational analysis and the atmospheric general circulation model experiments both suggest that STWCPSST warming acts to increase the Arctic geopotential height and temperature in the following season. This atmospheric response extends to Greenland, providing favorable conditions for developing the negative phase of the NAO. SIC and surface albedo tend to decrease over the Beaufort Sea in summer, linked to the positive surface net shortwave flux. Energy balance considering radiative and turbulent fluxes reveal that available energy that can heat surface is larger over the Arctic and Greenland and smaller over the south of Greenland, in response to the STWCPSST warming in spring. XXXX Arctic & Atlantic: Positive upper-level height/T anomaly over the Arctic and Greenland, and a negative anomaly over the central-eastern Atlantic, resembling the (-) phase of the NAO. Pacific: The negative height/T anomaly over the mid-latitudes, along with the positive anomaly over the STWCP, where 1degC warming above climatology is prescribed. Discussion: It is likely that the Arctic gets warm and the NAO is in the negative phase in response to the STWCP warming. But, there are other factors (e.g., internal variability) that contribute to determination of the NAO phase: not always the negative phase of the NAO in the event of STWCP warming (e.g.: recent winters and near neutral NAO in 2017 summer).

Spring hydrology determines summer net carbon uptake in northern ecosystems

International Nuclear Information System (INIS)

Yi, Yonghong; Kimball, John S; Reichle, Rolf H

2014-01-01

Increased photosynthetic activity and enhanced seasonal CO 2 exchange of northern ecosystems have been observed from a variety of sources including satellite vegetation indices (such as the normalized difference vegetation index; NDVI) and atmospheric CO 2 measurements. Most of these changes have been attributed to strong warming trends in the northern high latitudes (⩾50° N). Here we analyze the interannual variation of summer net carbon uptake derived from atmospheric CO 2 measurements and satellite NDVI in relation to surface meteorology from regional observational records. We find that increases in spring precipitation and snow pack promote summer net carbon uptake of northern ecosystems independent of air temperature effects. However, satellite NDVI measurements still show an overall benefit of summer photosynthetic activity from regional warming and limited impact of spring precipitation. This discrepancy is attributed to a similar response of photosynthesis and respiration to warming and thus reduced sensitivity of net ecosystem carbon uptake to temperature. Further analysis of boreal tower eddy covariance CO 2 flux measurements indicates that summer net carbon uptake is positively correlated with early growing-season surface soil moisture, which is also strongly affected by spring precipitation and snow pack based on analysis of satellite soil moisture retrievals. This is attributed to strong regulation of spring hydrology on soil respiration in relatively wet boreal and arctic ecosystems. These results document the important role of spring hydrology in determining summer net carbon uptake and contrast with prevailing assumptions of dominant cold temperature limitations to high-latitude ecosystems. Our results indicate potentially stronger coupling of boreal/arctic water and carbon cycles with continued regional warming trends. (letters)

Spring Hydrology Determines Summer Net Carbon Uptake in Northern Ecosystems

Science.gov (United States)

Yi, Yonghong; Kimball, John; Reichle, Rolf H.

2014-01-01

Increased photosynthetic activity and enhanced seasonal CO2 exchange of northern ecosystems have been observed from a variety of sources including satellite vegetation indices (such as the Normalized Difference Vegetation Index; NDVI) and atmospheric CO2 measurements. Most of these changes have been attributed to strong warming trends in the northern high latitudes (greater than or equal to 50N). Here we analyze the interannual variation of summer net carbon uptake derived from atmospheric CO2 measurements and satellite NDVI in relation to surface meteorology from regional observational records. We find that increases in spring precipitation and snow pack promote summer net carbon uptake of northern ecosystems independent of air temperature effects. However, satellite NDVI measurements still show an overall benefit of summer photosynthetic activity from regional warming and limited impact of spring precipitation. This discrepancy is attributed to a similar response of photosynthesis and respiration to warming and thus reduced sensitivity of net ecosystem carbon uptake to temperature. Further analysis of boreal tower eddy covariance CO2 flux measurements indicates that summer net carbon uptake is positively correlated with early growing-season surface soil moisture, which is also strongly affected by spring precipitation and snow pack based on analysis of satellite soil moisture retrievals. This is attributed to strong regulation of spring hydrology on soil respiration in relatively wet boreal and arctic ecosystems. These results document the important role of spring hydrology in determining summer net carbon uptake and contrast with prevailing assumptions of dominant cold temperature limitations to high-latitude ecosystems. Our results indicate potentially stronger coupling of boreal/arctic water and carbon cycles with continued regional warming trends.

Evaluation of drinks contribution to energy intake in summer and winter.

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Malisova, Olga; Bountziouka, Vassiliki; Zampelas, Antonis; Kapsokefalou, Maria

2015-05-15

All drinks hydrate and most also provide nutrients and energy. Our objective was to evaluate the contribution of drinks to total energy intake in summer and winter. Data were obtained using the Water Balance Questionnaire (WBQ) from a sample of the general population in Athens, Greece (n = 984), 473 individuals (42 ± 18 years) in summer and 511 individuals (38 ± 20 years) in winter stratified by sex and age. The WBQ embeds a semi-quantitative food frequency questionnaire of 58 foods and the Short International Physical Activity Questionnaire. Data were analyzed for the contribution of drinks to total energy intake. In winter, total energy intake was 2082 ± 892 kcal/day; energy intake from drinks was 479 ± 286 kcal/day and energy expenditure 1860 ± 390 kcal/day. In summer, total energy intake was 1890 ± 894 kcal/day, energy intake from drinks 492 ± 499 kcal/day and energy expenditure 1830 ± 491 kcal/day. Energy intake from drinks in summer was higher than in winter (p drinks, milk, chocolate milk and alcoholic drinks contributed approximately 75% of energy from drinks. Fruit juice and sugar-sweetened drinks, including soft drinks and fruit juice based drinks, were consumed less frequently contributing up to 25% of drink energy intake. Drinks contribute approximately 1/4 of total energy intake depending on the energy content of the drink and frequency of consumption. Coffee, dairy and alcoholic drinks were the main energy contributors.

A 900-Year Diatom and Chrysophyte Record of Spring Mixing and Summer Stratification From Varved Lake Mina, West-Central Minnesota, USA

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St. Jacques, J.; Cumming, B. F.; Smol, J. P.

2009-05-01

A high-resolution, independent pollen-inferred paleoclimate record and direct algal seasonality data from the actual time of sediment deposition are used to interpret the high-resolution diatom and chrysophyte record of varved Lake Mina, west-central Minnesota, USA during AD 1116-2002. This direct algal seasonality information was obtained by a new technique of splitting varves into constituent winter-spring and summer lamina, and separately analyzing the siliceous algae in each layer. Analyses of integrated, continuous four-year diatom and chrysophyte samples from a sedimentary sequence show that the time period AD 1116-1478 (i.e. the Atlantic- centered Medieval Climate Anomaly (MCA)) was characterized by periods of vigorous and prolonged spring mixing, suggesting that ice-out occurred early. However, the warm summer temperatures in the MCA, particularly in a massive drought spanning AD 1300-1400, frequently caused the lake to stratify strongly, leading to nutrient depletion. During AD 1478-1870 (i.e. the Atlantic-centered Little Ice Age (LIA)), Lake Mina was characterized by weak spring circulation and increasing nutrient depletion, suggesting late ice-out conditions. Strong summer stratification and/or nutrient depletion in both time periods is shown by the occurrence of the nutrient-poor oligotrophic taxon Cyclotella pseudostelligera. The diatom and chrysophyte assemblages of the period of Euro-American settlement AD 1870-2002 show higher nutrient availability and increased spring mixing intensity, due to forest clearance and increasingly earlier ice-out (documented in regional historical records).

Ecological effects of spring and late summer applications of lambda-cyhalothrin on freshwater microcosms.

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Van Wijngaarden, R P A; Brock, T C M; van den Brink, P J; Gylstra, R; Maund, S J

2006-02-01

The aim of the study was to compare the effects of the pyrethroid insecticide lambda-cyhalothrin (treated at 10, 25, 50, 100, 250 ng active ingredient a.i./L) on a drainage ditch ecosystem in spring and late summer. Microcosms (water volume approximately 430 L) were established using enclosures in a 50-cm-deep experimental ditch system containing communities typical of macrophyte-dominated freshwater ecosystems. Effects on macroinvertebrates, zooplankton, phytoplankton, macrophytes, and community metabolism were assessed and evaluated using univariate and multivariate statistical techniques. The macroinvertebrate community responded most clearly to treatment and, as anticipated, insects and crustaceans were among the most sensitive organisms. Statistical analysis showed that the underlying community structure was significantly different between the spring and summer experiments. However, the most sensitive species (Chaoborus obscuripes and Gammarus pulex) were abundant in spring as well as in late summer. In spring and late summer, only slight and transient effects were observed at the community level in the 10-ng/L treatment. Overall, the study did not show substantial differences in the responses of sensitive taxa between spring and late summer treatments, and effects thresholds were similar irrespective of season of treatment.

The effect of different winter and early spring removal treatments on ...

African Journals Online (AJOL)

Regrowth of parent tillers was appreciable only where clipping was lenient (to 10 cm). Burning destroyed all parent tillers. Lateral tillers developed poorly on all plots mown in early and mid-winter and on those burned in late winter and early spring. Lateral tillers yielded best all over treatment times when cutting was intense ...

Unusually amplified summer or winter indoor levels of radon

International Nuclear Information System (INIS)

Gammage, R.B.; Dudney, C.S.; Wilson, D.L.

1993-01-01

The ratios of winter/summer indoor radon levels for houses in different regions of the southern Appalachians are characterized by individual log-normal distributions with geometric means both above and below unity. In some counties and cities, subpopulations of houses have unusually exaggerated winter/summer ratios of indoor radon, as well as high indoor radon levels, during periods of either warm or cool weather. It is proposed that in many instances, houses are communicating with larger than normal underground reservoirs of radon-bearing air in hilly karst terrains; differences between the outdoor and underground air temperatures are believed to provide density gradients producing aerostatic pressure differences for seasonally directed underground transport and subsequently elevated indoor radon. These seasonal movements of air are analogous to the well-known underground chimney effects, which produce interzonal flows of air inside caves

The effect of different winter and early spring removal treatments on ...

African Journals Online (AJOL)

Lateral tillers developed poorly on all plots mown in early and mid-winter and on those burned in late winter and early spring. Lateral tillers yielded best all over treatment times when cutting was intense (to 5 cm). Herbage yields from lateral growth were higher when treatments were applied in April and August, than when ...

Winter predation by insectivorous birds and consequences for arthropods and plants in summer.

Science.gov (United States)

Barber, Nicholas A; Wouk, Jennifer

2012-12-01

Top-down effects of predators can have important consequences for ecosystems. Insectivorous birds frequently have strong predation effects on herbivores and other arthropods, as well as indirect effects on herbivores' host plants. Diet studies have shown that birds in temperate ecosystems consume arthropods in winter as well as in summer, but experimental studies of bird predation effects have not attempted to quantitatively separate winter predation impacts from those in summer. To understand if winter foraging by insectivorous birds has consequences for arthropods or plants, we performed a meta-analysis of published bird exclusion studies in temperate forest and shrubland habitats. We categorized 85 studies from 41 publications by whether birds were excluded year-round or only in summer, and analyzed arthropod and plant response variables. We also performed a manipulative field experiment in which we used a factorial design to exclude birds from Quercus velutina Lam. saplings in winter and summer, and censused arthropods and herbivore damage in the following growing season. In the meta-analysis, birds had stronger negative effects on herbivores in studies that included winter exclusion, and this effect was not due to study duration. However, this greater predation effect did not translate to a greater impact on plant damage or growth. In the field experiment, winter exclusion did not influence herbivore abundance or their impacts on plants. We have shown that winter feeding by temperate insectivorous birds can have important consequences for insect herbivore populations, but the strength of these effects may vary considerably among ecosystems. A full understanding of the ecological roles of insectivorous birds will require explicit consideration of their foraging in the non-growing season, and we make recommendations for how future studies can address this.

School in nature from spring to winter

OpenAIRE

MLSOVÁ, Martina

2012-01-01

The bachelor's thesis "Outdoor school from spring to winter" deals with the influence of field teaching on the locomotor development of preschool children. Based on specialized literature its theoretical part summarizes the influence of the natural environment on the child's development. It describes the benefits of field teaching, it deals with the term "Outdoor school" nowadays and in the past and with the locomotor development of children. The practical part includes an elaborated yearlong...

Comparison of aerosol effects on simulated spring and summer hailstorm clouds

Science.gov (United States)

Yang, Huiling; Xiao, Hui; Guo, Chunwei; Wen, Guang; Tang, Qi; Sun, Yue

2017-07-01

Numerical simulations are carried out to investigate the effect of cloud condensation nuclei (CCN) concentrations on microphysical processes and precipitation characteristics of hailstorms. Two hailstorm cases are simulated, a spring case and a summer case, in a semiarid region of northern China, with the Regional Atmospheric Modeling System. The results are used to investigate the differences and similarities of the CCN effects between spring and summer hailstorms. The similarities are: (1) The total hydrometeor mixing ratio decreases, while the total ice-phase mixing ratio enhances, with increasing CCN concentration; (2) Enhancement of the CCN concentration results in the production of a greater amount of small-sized hydrometeor particles, but a lessening of large-sized hydrometeor particles; (3) As the CCN concentration increases, the supercooled cloud water and rainwater make a lesser contribution to hail, while the ice-phase hydrometeors take on active roles in the growth of hail; (4) When the CCN concentration increases, the amount of total precipitation lessens, while the role played by liquid-phase rainfall in the amount of total precipitation reduces, relatively, compared to that of ice-phase precipitation. The differences between the two storms include: (1) An increase in the CCN concentration tends to reduce pristine ice mixing ratios in the spring case but enhance them in the summer case; (2) Ice-phase hydrometeor particles contribute more to hail growth in the spring case, while liquid water contributes more in the summer case; (3) An increase in the CCN concentration has different effects on surface hail precipitation in different seasons.

Long-term changes of South China Sea surface temperatures in winter and summer

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Park, Young-Gyu; Choi, Ara

2017-07-01

Utilizing available atmospheric and oceanographic reanalysis data sets, the long-term trend in South China Sea (SCS) sea surface temperature (SST) between 1950 and 2008 and the governing processes are investigated. Both winter and summer SST increased by comparable amounts, but the warming patterns and the governing processes were different. Strong warming in winter occurred in a deep central area, and during summer in the southern region. In winter the net heat flux into the sea increased, contributing to the warming. The spatial pattern of the heat flux, however, was different from that of the warming. Heat flux increased over the coastal area where warming was weaker, but decreased over the deeper area where warming was stronger. The northeasterly monsoon wind weakened lowering the shoreward Ekman transport and the sea surface height gradient. The cyclonic gyre which transports cold northern water to the south weakened, thereby warming the ocean. The effect was manifested more strongly along the southward western boundary current inducing warming in the deep central part. In summer however, the net surface heat flux decreased and could not contribute to the warming. Over the southern part of the SCS, the weakening of the southwesterly summer monsoon reduced southeastward Ekman transport, which is parallel to the mean SST gradient. Southeastward cold advection due to Ekman transport was reduced, thereby warming the surface near the southeastern boundary of the SCS. Upwelling southeast of Vietnam was also weakened, raising the SST east of Vietnam contributing to the southern summer warming secondarily. The weakening of the winds in each season was the ultimate cause of the warming, but the responses of the ocean that lead to the warming were different in winter and summer.

Experimental research on the poly-aluminum chloride for treating the Pi River water in winter and summer

Science.gov (United States)

Jia, Rusheng; Bai, Yulin; Yang, Jie

2018-02-01

In the beaker experiments that the disposal of low turbidity water, we observed the influence of some factors, such as the dosage of poly-aluminum chloride coagulant, the pH value of raw water, in disposing the high natural organic matters of low turbidity water in winter and summer. we discussed the removal of residual aluminum and UV254 in summer. The experimental results show that when the turbidity is less than 10 NTU, the optimum dosage are 14.4 mg.L-1 and 8.2 mg.L-1 respectively in winter and summer. No matter in winter or summer, the effect of pH value on coagulation treatment is very significant, the best pH value is about 8.1. In summer, with the increase of dosage of poly-aluminum chloride, residual aluminum increased slowly after decrease, turbidity and UV254 after precipitation is similar removal trend. Finally, according to the current market price of poly-aluminum chloride economic analysis, daily differences in pharmaceutical costs about 1600 yuan in summer and winter in the second water plant in Lu’an.

Heredity of flake- and stripe-variegated traits and their introduction into Japanese day-neutral winter-flowering sweet pea (Lathyrus odoratus L.) cultivars.

Science.gov (United States)

Yagishita, Yoshimi; Hara, Yasuhide; Nakayama, Masayoshi

2018-01-01

Sweet pea ( Lathyrus odoratus L.) is a major cut flower in Japan, generally grown in greenhouses in winter to spring. The wild-type sweet pea is a long-day summer-flowering plant. The day-neutral winter-flowering ability, which allows cut-flower production in Japan, is a recessive phenotype that emerged by spontaneous mutation. Although Japanese winter-flowering cultivars and additionally spring-flowering cultivars, which have semi-long-day flowering ability generated by crossing the winter- and summer-flowering cultivars, have superior phenotypes for cut flowers, they have limited variation in color and fragrance. In particular, variegated phenotypes do not appear in modern winter- and spring-flowering cultivars, only in summer-flowering cultivars. We try to expand the phenotypic diversity of Japanese cut flower cultivars. In the processes, we introduced the variegated phenotypes by crossing with summer-flowering cultivars, and succeeded in breeding some excellent cultivars. During breeding, we analyzed the segregation ratios and revealed the heredity of the phenotypes. Here we review the heredity of these variegated phenotypes and winter-flowering phenotypes and their related genes. We also describe how we introduced the trait into winter-flowering cultivars, tracing their pedigrees to show both phenotypes and genotypes of the progeny at each generation. This knowledge is useful for the efficient breeding of new variegated cultivars.

Monitoring the migrations of wild Snake River spring/summer chinook salmon smolts, 1995. Annual report

International Nuclear Information System (INIS)

Achord, S.; Eppard, M.B.; Sandford, B.P.; Matthews, G.M.

1996-09-01

We PIT tagged wild spring/summer chinook-salmon parr in the Snake River Basin in 1994 and subsequently monitored these fish during their smolt migration through Lower Granite, Little Goose, Lower Monumental, McNary, John Day, and Bonneville Darns during spring, summer, and fall 1995. This report details our findings. The goals of this study are to (1) characterize the migration timing of different wild stocks of Snake River spring/summer chinook salmon smolts at dams on the Snake and Columbia Rivers, (2) determine if consistent patterns are apparent, and (3) determine what environmental factors influence migration timing

KPI Graduate Executive Summary Report, Summer 2000-Winter 2001.

Science.gov (United States)

Sheridan Coll. (Ontario).

Summarizes findings from the Key Performance Indicator Satisfaction Survey administered by Sheridan College in the summer 2000, fall 2000, and winter 2001 terms. This survey was administered in compliance with the Ontario government's efforts to increase the accountability of the Colleges of Applied Arts and Technology through the measurement of…

Variation of phytoplankton biomass and primary production in Daya Bay during spring and summer

International Nuclear Information System (INIS)

Song Xingyu; Huang Liangmin; Zhang Jianlin; Huang, Xiaoping; Zhang Junbin; Yin Jianqiang; Tan Yehui; Liu Sheng

2004-01-01

Environmental factors, phytoplankton biomass (Chl a) and primary production of two water areas in Daya Bay (Dapeng'ao Bay and Aotou Bay) were investigated during the transition period from spring to summer. Chl a ranged from 3.20 to 13.62 and 13.43 to 26.49 mg m -3 in Dapeng'ao Bay and Aotou Bay respectively, if data obtained during red tides are excluded. Primary production varied between 239.7 and 1001.4 mgC m -2 d -1 in Dapeng'ao Bay. The regional distribution of Chl a and primary production were mostly consistent from spring to summer in both bays. Seasonal transition characters have been found in Daya Bay from spring to summer, including high values of DO, nitrate and silicate. Size structures of phytoplankton and its primary production do not change very much from spring to summer, with micro-phytoplankton dominating and contributing about 50% of the whole. In Daya Bay, phytoplankton is limited by nitrogen in spring, and by phosphate in summer. Artificial impacts are evident from high temperature effluent from nuclear power stations, aquaculture and sewage. During the investigation, a red tide occurred in Aotou Bay, with a maximum Chl a of 103.23 mg m -3 at surface and primary production of 2721.9 mgC m -2 d -1 in the red tide center. Raised water temperature and nutrient supply from land-sources help to stimulate annual red tides

Minthorn Springs Creek Summer Juvenile Release and Adult Collection Facility; 1994 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Rowan, Gerald D.

1995-05-01

The Confederated Tribes of the Umatilla Indian Reservation (CTUIR) and Oregon Department of Fish and Wildlife (ODFW) are cooperating in a joint effort to enhance steelhead and re-establish salmon runs in the Umatilla River Basin. Bonifer Pond, Minthorn Springs and Imeques C-mem-ini-kem acclimation facilities are operated for acclimation and release of juvenile summer steelhead (Oncorhynchus mykiss), fall and spring chinook salmon (O. tshawytscha) and coho salmon (O, kisutch). Minthorn is also used for holding and spawning summer steelhead, fall chinook and coho salmon. In the spring of 1994, juvenile summer steelhead were acclimated at Bonifer and Minthorn. At Imeques C-mem-ini-kem, juvenile spring chinook were acclimated in the spring and fall. A total of 92 unmarked and 42 marked summer steelhead were collected for broodstock at Three Mile Dam from October 1, 1993 through May 2, 1994 and held at Minthorn. An estimated 234,432 green eggs were taken from 48 females. The eggs were transferred to Irrigon Hatchery for incubation and early rearing. Fingerlings were transferred to Umatilla Hatchery for final rearing and release into the Umatilla River in 1995. Fall chinook and coho salmon broodstock were not collected in 1994. Coded-wire tag recovery information was accessed to determine the contribution of Umatilla River releases to ocean, Columbia River and Umatilla River fisheries. Total estimated juvenile adult survival rates are detailed in this document.

Asthma prevalence in German Olympic athletes: A comparison of winter and summer sport disciplines.

Science.gov (United States)

Selge, Charlotte; Thomas, Silke; Nowak, Dennis; Radon, Katja; Wolfarth, Bernd

2016-09-01

Prevalence of asthma in elite athletes shows very wide ranges. It remains unclear to what extent this is influenced by the competition season (winter vs. summer) or the ventilation rate achieved during competition. The aim of this study was to evaluate prevalence of asthma in German elite winter and summer athletes from a wide range of sport disciplines and to identify high risk groups. In total, 265 German elite winter athletes (response 77%) and 283 German elite summer athletes (response 64%) answered validated respiratory questionnaires. Using logistic regression, the asthma risks associated with competition season and ventilation rate during competition, respectively, were investigated. A subset of winter athletes was also examined for their FENO-levels and lung function. With respect to all asthma outcomes, no association was found with the competition season. Regarding the ventilation rate, athletes in high ventilation sports were at increased risk of asthma, as compared to athletes in low ventilation sports (doctors' diagnosed asthma: OR 2.32, 95% CI 1.19-4.53; use of asthma medication: OR 4.46, 95% CI 1.52-13.10; current wheeze or use of asthma medication: OR 2.78, 95% CI 1.34-5.76). Athletes with doctors' diagnosed asthma were at an approximate four-fold risk of elevated FENO-values. The clinically relevant finding of this study is that athletes' asthma seems to be more common in sports with high ventilation during competition, whereas the summer or winter season had no impact on the frequency of the disease. Among winter athletes, elevated FENO suggested suboptimal control of asthma. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evidence of the Lower Thermospheric Winter-to-Summer Circulation

Science.gov (United States)

Qian, L.; Burns, A. G.; Yue, J.

2017-12-01

Numerical studies showed that the lower thermospheric winter-to-summer circulation is driven by wave dissipation, and it plays a significant role in trace gas distributions in the mesosphere and lower thermosphere (MLT), and in the composition of the thermosphere. Direct observations of this circulation are difficult. However, it leaves clear signatures in tracer distributions. Recent analysis of CO2 observed by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite showed dynamically driven dense isolines of CO2 at summer high latitudes. We conduct modeling and observational studies to understand the CO2 distribution and circulation patterns in the MLT. We found that there exists maximum vertical gradient of CO2 at summer high latitudes, driven by the convergence of the upwelling of the mesospheric circulation and the downwelling of the lower thermospheric circulation; this maximum vertical gradient of CO2 is located at a higher altitude in the winter hemisphere, driven by the convergence of the upwelling of the lower thermospheric circulation and the downwelling of the solar-driven thermospheric circulation. Based on SABER CO2 distribution, the bottom of the lower thermospheric circulation is located between 95 km and 100 km, and it has a vertical extent of 10 km. Analysis of the SABER CO2 and temperature at summer high latitudes showed that the bottom of this circulation is consistently higher than the mesopause height by 10 km; and its location does not change much between solar maximum and solar minimum.

On the seasonal transition from winter to spring in Europe and the "seasonal feeling" relating to "Fasnacht" in comparison with those in East Asia (Toward an interdisciplinary activity on climate and cultural understanding education)

Science.gov (United States)

Kato, Kuranoshin; Kato, Haruko; Hamaki, Tatsuya

2016-04-01

As mentioned in the introduction of the EGU2016 abstract (Kato et al., submitted to CL5.06/AS4.9), there are many stages with rapid seasonal transitions in East Asia, resulting in the variety of "seasonal feeling". The seasonal cycle has been an important background for generation of the arts. On the other hand, around Germany located near the western edge of the Eurasian Continent, there are so many music or literature works in which the "May" is treated as the special season (comparison of the climate and songs on "spring" (or "May") between Japan and Germany was tried in a book by Kato, H. and K. Kato, although written in Japanese). The Japanese researchers on German Literature suggested that there are basically two seasons "winter" and "summer" around Germany, with the transitional stages of spring and autumn. The concepts of the battle between winter and summer, and driving winter away, and so on, around Germany seem to show rather different seasonal feelings from that around the Japan Islands (Oshio 1982; Miyashita 1982; Takeda 1980). A traditional event there called "Fasnacht" for driving winter away is held in March or slightly earlier stage (Takeda 1980; Ueda and Ebato 1988). Kato et al. (EGU2016, submitted to CL5.06/AS4.9) will report the synoptic climatological features on the seasonal transition from winter to spring in Europe based on the daily data, by comparing with that in East Asia. In this presentation, we will discuss on the climatological background for the "seasonal feeling" leading to such as the battle between winter and summer, driving winter away, including "Fasnacht", also by referring to some songs (children's songs, etc.). At the same time, the analysis results on the seasonal transition from winter to spring in Europe in comparison with those in East Asia by Kato et al. (EGU2016) will be also referred to. On the other hand, although it is around the end of March when the "wintertime pressure pattern" on the daily surface weather maps in

Differences in Number of Midbrain Dopamine Neurons Associated with Summer and Winter Photoperiods in Humans.

Directory of Open Access Journals (Sweden)

Tim D Aumann

Full Text Available Recent evidence indicates the number of dopaminergic neurons in the adult rodent hypothalamus and midbrain is regulated by environmental cues, including photoperiod, and that this occurs via up- or down-regulation of expression of genes and proteins that are important for dopamine (DA synthesis in extant neurons ('DA neurotransmitter switching'. If the same occurs in humans, it may have implications for neurological symptoms associated with DA imbalances. Here we tested whether there are differences in the number of tyrosine hydroxylase (TH, the rate-limiting enzyme in DA synthesis and DA transporter (DAT immunoreactive neurons in the midbrain of people who died in summer (long-day photoperiod, n = 5 versus winter (short-day photoperiod, n = 5. TH and DAT immunoreactivity in neurons and their processes was qualitatively higher in summer compared with winter. The density of TH immunopositive (TH+ neurons was significantly (~6-fold higher whereas the density of TH immunonegative (TH- neurons was significantly (~2.5-fold lower in summer compared with winter. The density of total neurons (TH+ and TH- combined was not different. The density of DAT+ neurons was ~2-fold higher whereas the density of DAT- neurons was ~2-fold lower in summer compared with winter, although these differences were not statistically significant. In contrast, midbrain nuclear volume, the density of supposed glia (small TH- cells, and the amount of TUNEL staining were the same in summer compared with winter. This study provides the first evidence of an association between environmental stimuli (photoperiod and the number of midbrain DA neurons in humans, and suggests DA neurotransmitter switching underlies this association.

Development of a model system to identify differences in spring and winter oat.

Science.gov (United States)

Chawade, Aakash; Lindén, Pernilla; Bräutigam, Marcus; Jonsson, Rickard; Jonsson, Anders; Moritz, Thomas; Olsson, Olof

2012-01-01

Our long-term goal is to develop a Swedish winter oat (Avena sativa). To identify molecular differences that correlate with winter hardiness, a winter oat model comprising of both non-hardy spring lines and winter hardy lines is needed. To achieve this, we selected 294 oat breeding lines, originating from various Russian, German, and American winter oat breeding programs and tested them in the field in south- and western Sweden. By assaying for winter survival and agricultural properties during four consecutive seasons, we identified 14 breeding lines of different origins that not only survived the winter but also were agronomically better than the rest. Laboratory tests including electrolytic leakage, controlled crown freezing assay, expression analysis of the AsVrn1 gene and monitoring of flowering time suggested that the American lines had the highest freezing tolerance, although the German lines performed better in the field. Finally, six lines constituting the two most freezing tolerant lines, two intermediate lines and two spring cultivars were chosen to build a winter oat model system. Metabolic profiling of non-acclimated and cold acclimated leaf tissue samples isolated from the six selected lines revealed differential expression patterns of 245 metabolites including several sugars, amino acids, organic acids and 181 hitherto unknown metabolites. The expression patterns of 107 metabolites showed significant interactions with either a cultivar or a time-point. Further identification, characterisation and validation of these metabolites will lead to an increased understanding of the cold acclimation process in oats. Furthermore, by using the winter oat model system, differential sequencing of crown mRNA populations would lead to identification of various biomarkers to facilitate winter oat breeding.

Analysis on energy-saving path of rural buildings in hot summer and cold winter zone

Science.gov (United States)

Huang, Mingqiang; Li, Jinheng

2018-02-01

Since the reform and opening policy, the construction of rural area in China has become more and more important. The idea of establishing green villages needs to be accepted and recognized by the public. The hot summer and cold winter zone combines two contradictory weather conditions that is cold winter and hot summer. So the living conditions are limited. In response to this climate, residents extensively use electric heaters or air conditioning to adjust the indoor temperature, resulting in energy waste and environmental pollution. In order to improve the living conditions of residents, rural area energy conservation has been put on the agenda. Based on the present situation and energy consumption analysis of the rural buildings in the hot summer and cold winter zone, this article puts forward several energy saving paths from government, construction technology and so on

Influence of Western Tibetan Plateau Summer Snow Cover on East Asian Summer Rainfall

Science.gov (United States)

Wang, Zhibiao; Wu, Renguang; Chen, Shangfeng; Huang, Gang; Liu, Ge; Zhu, Lihua

2018-03-01

The influence of boreal winter-spring eastern Tibetan Plateau snow anomalies on the East Asian summer rainfall variability has been the focus of previous studies. The present study documents the impacts of boreal summer western and southern Tibetan Plateau snow cover anomalies on summer rainfall over East Asia. Analysis shows that more snow cover in the western and southern Tibetan Plateau induces anomalous cooling in the overlying atmospheric column. The induced atmospheric circulation changes are different corresponding to more snow cover in the western and southern Tibetan Plateau. The atmospheric circulation changes accompanying the western Plateau snow cover anomalies are more obvious over the midlatitude Asia, whereas those corresponding to the southern Plateau snow cover anomalies are more prominent over the tropics. As such, the western and southern Tibetan Plateau snow cover anomalies influence the East Asian summer circulation and precipitation through different pathways. Nevertheless, the East Asian summer circulation and precipitation anomalies induced by the western and southern Plateau snow cover anomalies tend to display similar distribution so that they are more pronounced when the western and southern Plateau snow cover anomalies work in coherence. Analysis indicates that the summer snow cover anomalies over the Tibetan Plateau may be related to late spring snow anomalies due to the persistence. The late spring snow anomalies are related to an obvious wave train originating from the western North Atlantic that may be partly associated with sea surface temperature anomalies in the North Atlantic Ocean.

Weed infestation of crops in different soils in the protective zone of Roztocze National Park. Part I. Winter and spring cereals

Directory of Open Access Journals (Sweden)

Marta Ziemińska-Smyk

2013-12-01

Full Text Available The study on weed infestation of crops in different soils in the protective zone of RPN was conducted in the years 1991-1995. The characterization of weed infestation of winter and spring cereals was based on 306 phytosociological records. made with the use of Braun-Blanquet method. The degree of weed infestation in the fields in the protective zone of RPN depended on environment conditions. Both winter and spring cereals in majority of soils were most infested by: Cenaturea cyanus, Apera spica-venti and Vicia hirsta. In the lightest podsolic soils, made of loose sand and slightly loamy sand. winter and spring cereals were additionally infested by Equisetum arvense and two acidophylic species: Seleranthus annuus and Spergula arvensis. The crops in brown loess soil were infested by Matricaria maritima subsp. inodora. The most difficult weed species in brown soil formed from gaizes and limestone soil were: Convolvulus arvensis, Papaver rhoeas and Galium aparine. Moreover winter cercals in limestone soil showed high or medium infestation with Consolida regalis, Aethusa cynapium, Lathyrus tuberosus and low infestation with Apera spica-venti and Centaurea cyanus. Spring cereals were less infested than winter cereals. Apera spica-venti and Centaurea cyanus were less common with spring cereals than with winter cereals. Also, spring cereals showed high or medium infestation with Convolvulus arvensis. Spring cereals in some soil units were infested by Chenopodium album and Stellaria media. There was also higher infestation of spring cereals in limestone soils with Avena fatua, Veronica persica, Sinapis arvensis and Sonchus arvensis, compared to winter cereals in limestone soils.

Reduced irrigation increases the water use efficiency and productivity of winter wheat-summer maize rotation on the North China Plain.

Science.gov (United States)

Wang, Yunqi; Zhang, Yinghua; Zhang, Rui; Li, Jinpeng; Zhang, Meng; Zhou, Shunli; Wang, Zhimin

2018-03-15

The groundwater table has fallen sharply over the last 30years on the North China Plain, resulting in a shortage of water for winter wheat irrigation. Reducing irrigation may be an important strategy to maintain agricultural sustainability in the region; however, few studies have evaluated the transition from conventional irrigation management practices to reduced irrigation management practices in the winter wheat-summer maize rotation system. Here, we compare the yield, water consumption, and water use efficiency of winter wheat-summer maize rotation under conventional irrigation and reduced irrigation on the North China Plain from 2012 to 2015. Reducing irrigation decreased the yield but increased the water use efficiency and significantly advanced the harvest date of winter wheat. As a result, the summer maize sowing date advanced significantly, and the flowering date subsequently advanced 2-8days, thus extending the summer maize grain-filling stage. Therefore, the yield and water use efficiency of summer maize were higher under reduced irrigation than conventional irrigation, which compensated for the winter wheat yield loss under reduced irrigation. In addition, under reduced irrigation from 2012 to 2015, the yield and water use efficiency advantage of the winter wheat-summer maize rotation ranged from 0.0 to 9.7% and from 4.1 to 14.7%, respectively, and water consumption and irrigated water decreased by 20-61mm and 150mm, respectively, compared to conventional irrigation. Overall, the reduced irrigation management practice involving no irrigation after sowing winter wheat, and sowing summer maize on June 7 produced the most favorable grain yield with superb water use efficiency in the winter wheat-summer maize rotation. This study indicates that reducing irrigation could be an efficient means to cope with water resource shortages while maintaining crop production sustainability on the North China Plain. Copyright © 2017. Published by Elsevier B.V.

Field demonstration of automated demand response for both winter and summer events in large buildings in the Pacific Northwest

Energy Technology Data Exchange (ETDEWEB)

Piette, M.A.; Kiliccote, S.; Dudley, J.H. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

2013-11-15

There are growing strains on the electric grid as cooling peaks grow and equipment ages. Increased penetration of renewables on the grid is also straining electricity supply systems and the need for flexible demand is growing. This paper summarizes results of a series of field test of automated demand response systems in large buildings in the Pacific Northwest. The objective of the research was twofold. One objective was to evaluate the use demand response automation technologies. A second objective was to evaluate control strategies that could change the electric load shape in both winter and summer conditions. Winter conditions focused on cold winter mornings, a time when the electric grid is often stressed. The summer test evaluated DR strategies in the afternoon. We found that we could automate both winter and summer control strategies with the open automated demand response communication standard. The buildings were able to provide significant demand response in both winter and summer events.

Comparative proteomics reveals the physiological differences between winter tender shoots and spring tender shoots of a novel tea (Camellia sinensis L.) cultivar evergrowing in winter.

Science.gov (United States)

Liu, Shengjie; Gao, Jiadong; Chen, Zhongjian; Qiao, Xiaoyan; Huang, Hualin; Cui, Baiyuan; Zhu, Qingfeng; Dai, Zhangyan; Wu, Hualing; Pan, Yayan; Yang, Chengwei; Liu, Jun

2017-11-20

A recently discovered tea [Camellia sinensis (L.) O. Kuntze] cultivar can generate tender shoots in winter. We performed comparative proteomics to analyze the differentially accumulated proteins between winter and spring tender shoots of this clonal cultivar to reveal the physiological basis of its evergrowing character during winter. We extracted proteins from the winter and spring tender shoots (newly formed two leaves and a bud) of the evergrowing tea cultivar "Dongcha11" respectively. Thirty-three differentially accumulated high-confidence proteins were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF / TOF MS). Among these, 24 proteins had increased abundance while nine showed were decreased abundance in winter tender shoots as compared with the spring tender shoots. We categorized the differentially accumulated proteins into eight critical biological processes based on protein function annotation including photosynthesis, cell structure, protein synthesis & destination, transporters, metabolism of sugars and polysaccharides, secondary metabolism, disease/defense and proteins with unknown functions. Proteins with increased abundance in winter tender shoots were mainly related to the processes of photosynthesis, cytoskeleton and protein synthesis, whereas those with decreased abundance were correlated to metabolism and the secondary metabolism of polyphenolic flavonoids. Biochemical analysis showed that the total contents of soluble sugar and amino acid were higher in winter tender shoots while tea polyphenols were lower as compared with spring tender shoots. Our study suggested that the simultaneous increase in the abundance of photosynthesis-related proteins rubisco, plastocyanin, and ATP synthase delta chain, metabolism-related proteins eIF4 and protease subunits, and the cytoskeleton-structure associated proteins phosphatidylinositol transfer protein and profilin may be because of the adaptation of the

The utilization by sheep of winter and spring Smuts finger and ...

African Journals Online (AJOL)

An experiment was conducted on Smuts finger (Digitaria eriantha ssp. eriantha) and Kikuyu (Pennisetum clandestinum) pastures during a winter and spring period to study the effect of postruminal energy and/or protein supplementation on the selection pattern and performance of sheep. In a further experiment the digestion ...

Chemical composition, sources, and aging process of submicron aerosols in Beijing: Contrast between summer and winter

Science.gov (United States)

Hu, Weiwei; Hu, Min; Hu, Wei; Jimenez, Jose L.; Yuan, Bin; Chen, Wentai; Wang, Ming; Wu, Yusheng; Chen, Chen; Wang, Zhibin; Peng, Jianfei; Zeng, Limin; Shao, Min

2016-02-01

To investigate the seasonal characteristics of submicron aerosol (PM1) in Beijing urban areas, a high-resolution time-of-flight aerosol-mass-spectrometer (HR-ToF-AMS) was utilized at an urban site in summer (August to September 2011) and winter (November to December 2010), coupled with multiple state of the art online instruments. The average mass concentrations of PM1 (60-84 µg m-3) and its chemical compositions in different campaigns of Beijing were relatively consistent in recent years. In summer, the daily variations of PM1 mass concentrations were stable and repeatable. Eighty-two percent of the PM1 mass concentration on average was composed of secondary species, where 62% is secondary inorganic aerosol and 20% secondary organic aerosol (SOA). In winter, PM1 mass concentrations changed dramatically because of the different meteorological conditions. The high average fraction (58%) of primary species in PM1 including primary organic aerosol (POA), black carbon, and chloride indicates primary emissions usually played a more important role in the winter. However, aqueous chemistry resulting in efficient secondary formation during occasional periods with high relative humidity may also contribute substantially to haze in winter. Results of past OA source apportionment studies in Beijing show 45-67% of OA in summer and 22-50% of OA in winter can be composed of SOA. Based on the source apportionment results, we found 45% POA in winter and 61% POA in summer are from nonfossil sources, contributed by cooking OA in both seasons and biomass burning OA (BBOA) in winter. Cooking OA, accounting for 13-24% of OA, is an important nonfossil carbon source in all years of Beijing and should not be neglected. The fossil sources of POA include hydrocarbon-like OA from vehicle emissions in both seasons and coal combustion OA (CCOA) in winter. The CCOA and BBOA were the two main contributors (57% of OA) for the highest OA concentrations (>100 µg m-3) in winter. The POA

Winter-to-winter variations in indoor radon

International Nuclear Information System (INIS)

Mose, D.G.; Mushrush, G.W.; Kline, S.W.

1989-01-01

Indoor radon concentrations in northern Virginia and central Maryland show a strong dependence on weather. Winter tends to be associated with higher than average indoor radon, and summer with lower than average. However, compared to the winter of 1986-1987, the winter of 1987-1988 was warmer and drier. Consequently, winter-to-winter indoor radon decreased by about 25%. This winter-to-winter decrease is unexpectedly large, and simulates winter-to-summer variations that have been reported

Active summer carbon storage for winter persistence in trees at the cold alpine treeline.

Science.gov (United States)

Li, Mai-He; Jiang, Yong; Wang, Ao; Li, Xiaobin; Zhu, Wanze; Yan, Cai-Feng; Du, Zhong; Shi, Zheng; Lei, Jingpin; Schönbeck, Leonie; He, Peng; Yu, Fei-Hai; Wang, Xue

2018-03-12

The low-temperature limited alpine treeline is one of the most obvious boundaries in mountain landscapes. The question of whether resource limitation is the physiological mechanism for the formation of the alpine treeline is still waiting for conclusive evidence and answers. We therefore examined non-structural carbohydrates (NSC) and nitrogen (N) in treeline trees (TATs) and low-elevation trees (LETs) in both summer and winter in 11 alpine treeline cases ranging from subtropical monsoon to temperate continental climates across Eurasia. We found that tissue N concentration did not decrease with increasing elevation at the individual treeline level, but the mean root N concentration was lower in TATs than in LETs across treelines in summer. The TATs did not have lower tissue NSC concentrations than LETs in summer. However, the present study with multiple tree species across a large geographical scale, for the first time, revealed a common phenomenon that TATs had significantly lower NSC concentration in roots but not in the aboveground tissues than LETs in winter. Compared with LETs, TATs exhibited both a passive NSC storage in aboveground tissues in excess of carbon demand and an active starch storage in roots at the expense of growth reduction during the growing season. This starch accumulation disappeared in winter. Our results highlight some important aspects of the N and carbon physiology in relation to season in trees at their upper limits. Whether or to what extent the disadvantages of winter root NSC and summer root N level of TATs affect the growth of treeline trees and the alpine treeline formation needs to be further studied.

Summer temperatures in Europe and land heat fluxes in observation-based data and regional climate simulations

NARCIS (Netherlands)

Stegehuis, A.I.; Vautard, R.; Ciais, Ph.; Teuling, A.J.; Jung, P.

2013-01-01

The occurrence and intensity of heatwaves is expected to increase with climate change. Early warnings of hot summers have therefore a great socio-economical value. Previous studies have shown that hot summers are preceded by a Southern European rainfall deficit during winter, and higher spring

Comparative study on the health effects of smoking and indoor air pollution in summer and winter

Energy Technology Data Exchange (ETDEWEB)

Matsuki, H.; Kasuga, H.; Osaka, F.; Yanagisawa, Y.; Nishimura, H.

1985-08-01

This study compares summer and winter to demonstrate the health effects of indoor air pollution with special reference to NO/sub 2/ and smoking, on the subjects composed of 820 school children and their 546 mothers in the two areas with different ambient NO/sub 2/ concentrations. In either case, examination was carried out with standardized questionnaire test for respiratory symptoms, personal NO/sub 2/ exposure measurement using the filter badge by Yanagisawa, and analysis of urinary hydroxyproline and creatinine in two areas with different ambient NO/sub 2/ levels. Personal NO/sub 2/ exposure level in winter season was 2-3 times higher than that in summer, particularly NO/sub 2/ level among residents living in homes with non-vented stove for space heating was substantially higher from those of residents with vented stove. Wives with vented stove had a moderate exposure level in winter season by the contribution of NO/sub 2/ originated from the kitchen and poor ventilation rate. Since the hydroxyproline to creatinine ratio (HOP-ratio) of children increased more, their household location were nearer to any heavy traffic roads in summer, health effects from automobile exhaust were suggested only in summer season. In summer season, personal NO/sub 2/ exposure level were almost the same with the ambient NO/sub 2/ concentrations over both areas. These results suggest that indoor air pollution in winter season may be separated from outdoor air pollution. It was a matter of course that hydroxyproline to creatinine ratio in winter season was higher than that in summer, in any group and in any area, but the range of variation of hydroxyproline to creatinine ratio was smaller by far than that of personal NO/sub 2/ exposure level. Judging from urinary hydroxyproline to creatinine ratio, health effects of active smoking and passive smoking increased with increasing the number of smoked, dose-dependently in any season.

SERSO: Summer sun against winter ice; SERSO: Mit Sommer-Sonne gegen Winter-Glatteis

Energy Technology Data Exchange (ETDEWEB)

Eugster, W J [Polydynamics Engineering, Zuerich (Switzerland); Hess, K [Polydynamics Engineering, Bremgarten-Bern (Switzerland); Hopkirk, R J [Polydynamics Engineering, Maennedorf (Switzerland)

1997-12-01

Road surfaces absorb energy from the incoming solar radiation in the summer months. The SERSO project was conceived to collect this energy, store it and reuse it during the following winter period to eliminate ice formation on those same road surfaces. The acronym SERSO (Sonnenenergierueckgewinnung aus Strassenoberflaechen) means `solar energy recuperation from road surfaces`. This pilot unit having been conceived, researched an applied to a bridge on the Swiss national expressway A8 near Daerligen on the south side of the lake of Thun was officially opened on 22nd August 1994. Heat exchanger tubes carrying a water/glycol heat transfer fluid were built into the roadbed on the bridge, covering a total area of some 1`300 m{sup 2}. In summer these collect heat from the exposed carriageways, which is then transported in a closed hydraulic circuit to the neighbouring cylindrical underground rock heat storage volume. Within a diameter of 31.5 m and a depth of 65 m heat is exchanged between the heat transfer fluid and the rock via an array of 91 borehole heat exchangers. The operation of the pilot plant has been accompanied by detailed measurement campaign, whereby a total of 132 sensors are interrogated by remote datalogger. The data consist of temperature measurements at several depths and positions both in the roadbed and in the rock storage volume, of energy fluxes in the hydraulic system and of relevant meteorological data. The experiences gianed during the first two years of operation have shown that sufficient heat can indeed be collected in summer to maintain the bridge free of ice during the following winter. Moreover the energy balances derived from the measurements in the low temperature rock heat store have confirmed the predicted storage efficiency. (orig./AKF) [Deutsch] cVerkehrsflaechen heizen sich im Sommer durch Sonneneinstrahlung stark auf. Diese Sommerwaerme zu sammeln, zwischenzuspeichern und im Winter zur Verhinderung von Glatteisbildung wieder zu

PIXE analysis of airborne particulate matter from Xalostoc, Mexico: winter to summer comparison

International Nuclear Information System (INIS)

Flores M, J.; Aldape, F.; Diaz, R.V.; Hernandez-Mendez, B.; Garcia G, R.

1999-01-01

A study of elemental contents in airborne particulate matter from the industrial city of Xalostoc, Estado de Mexico, was performed using PIXE. The place has a great variety of industries, it is a heavily populated, and it is a part of Mexico City's conurbation, thus contributing significantly to its atmospheric pollution. At present, there is few information available about elemental contents in airborne particulate matter from that region. In this study, two sets of samples of airborne particulate matter were collected daily during periods of four weeks in summer 1996 and winter 1997; two samples a day, 12 h each, night-time and day-time. Results revealed important information about elemental contents in airborne particulate matter from that area, especially in the respirable fraction PM 2.5 . Comparison of night and day figures showed the presence of some elements such as Cu, Zn, and Pb, attributed, as it was expected, to uninterrupted industrial processes. Appearance of some other elements was more consistent only in either day-time or night-time due to diurnal or nocturnal industrial activities, or produced by human activities such as fuel combustion of automotive vehicles. Comparison of winter to summer results showed some other important features such as higher concentrations of pollutants in winter, because of the dry and cold weather, while summer samples exhibited lower concentrations mainly due to the presence of rain showers

Spring and Summer Spatial Distribution of Endangered Juvenile Lost River and Shortnose Suckers in Relation to Environmental Variables in Upper Klamath Lake, Oregon: 2007 Annual Report

Science.gov (United States)

Burdick, Summer M.; VanderKooi, Scott P.; Anderson, Greer O.

2009-01-01

Lost River sucker Deltistes luxatus and shortnose sucker Chasmistes brevirostris were listed as endangered in 1988 for a variety of reasons including apparent recruitment failure. Upper Klamath Lake, Oregon, and its tributaries are considered the most critical remaining habitat for these two species. Age-0 suckers are often abundant in Upper Klamath Lake throughout the summer months, but catches decline dramatically between late August and early September each year, and age-1 and older subadult suckers are rare. These rapid declines in catch rates and a lack of substantial recruitment into adult sucker populations in recent years suggests sucker populations experience high mortality between their first summer and first spawn. A lack of optimal rearing habitat may exacerbate juvenile sucker mortality or restrict juvenile growth or development. In 2007, we continued research on juvenile sucker habitat use begun by the U.S. Geological Survey (USGS) in 2001. Age-0 catch rates in 2006 were more than an order of magnitude greater than in previous years, which prompted us to refocus our research from age-0 suckers to age-1 sucker distributions and habitat use. We took a two-phased approach to our research in 2007 that included preliminary spring sampling and intense summer sampling components. Spring sampling was a pilot study designed to gather baseline data on the distribution of age-1 suckers as they emerge from winter in shoreline environments throughout Upper Klamath Lake (Chapter 1). Whereas, summer sampling was designed to quantitatively estimate the influence of environmental variables on age-0 and age-1 sucker distribution throughout Upper Klamath Lake, while accounting for imperfect detection (Chapter 2). In addition to these two components, we began a project to evaluate passive integrated transponder (PIT) tag loss and the effects of PIT tags on mortality of age-1 Lost River suckers (Chapter 3). The spring pilot study built the foundation for future research

IASI carbon monoxide validation over the Arctic during POLARCAT spring and summer campaigns

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M. Pommier

2010-11-01

Full Text Available In this paper, we provide a detailed comparison between carbon monoxide (CO data measured by the Infrared Atmospheric Sounding Interferometer (IASI/MetOp and aircraft observations over the Arctic. The CO measurements were obtained during North American (NASA ARCTAS and NOAA ARCPAC and European campaigns (POLARCAT-France, POLARCAT-GRACE and YAK-AEROSIB as part of the International Polar Year (IPY POLARCAT activity in spring and summer 2008. During the campaigns different air masses were sampled including clean air, polluted plumes originating from anthropogenic sources in Europe, Asia and North America, and forest fire plumes originating from Siberia and Canada. The paper illustrates that CO-rich plumes following different transport pathways were well captured by the IASI instrument, in particular due to the high spatial coverage of IASI. The comparison between IASI CO total columns, 0–5 km partial columns and profiles with collocated aircraft data was achieved by taking into account the different sensitivity and geometry of the sounding instruments. A detailed analysis is provided and the agreement is discussed in terms of information content and surface properties at the location of the observations. For profiles, the data were found to be in good agreement in spring with differences lower than 17%, whereas in summer the difference can reach 20% for IASI profiles below 8 km for polluted cases. For total columns the correlation coefficients ranged from 0.15 to 0.74 (from 0.47 to 0.77 for partial columns in spring and from 0.26 to 0.84 (from 0.66 to 0.88 for partial columns in summer. A better agreement is seen over the sea in spring (0.73 for total column and 0.78 for partial column and over the land in summer (0.69 for total columns and 0.81 for partial columns. The IASI vertical sensitivity was better over land than over sea, and better over land than over sea ice and snow allowing a higher potential to detect CO vertical distribution during

Comparison of summer and winter objectively measured physical activity and sedentary behavior in older adults

DEFF Research Database (Denmark)

Arnardottir, Nanna Yr; Oskarsdottir, Nina Dora; Brychta, Robert J.

2017-01-01

In Iceland, there is a large variation in daylight between summer and winter. The aim of the study was to identify how this large variation influences physical activity (PA) and sedentary behavior (SB). Free living PA was measured by a waist-worn accelerometer for one week during waking hours...... categories, except for the moderate-to-vigorous PA (MVPA), and SB was reduced. More lifestyle PA (LSPA) was accumulated in ≥5-min bouts during summer than winter, especially among highly active participants. This information could be important for policy makers and health professionals working with older...

Climate model assessment of changes in winter-spring streamflow timing over North America

Science.gov (United States)

Kam, Jonghun; Knutson, Thomas R.; Milly, Paul C. D.

2018-01-01

Over regions where snow-melt runoff substantially contributes to winter-spring streamflows, warming can accelerate snow melt and reduce dry-season streamflows. However, conclusive detection of changes and attribution to anthropogenic forcing is hindered by brevity of observational records, model uncertainty, and uncertainty concerning internal variability. In this study, a detection/attribution of changes in mid-latitude North American winter-spring streamflow timing is examined using nine global climate models under multiple forcing scenarios. In this study, robustness across models, start/end dates for trends, and assumptions about internal variability is evaluated. Marginal evidence for an emerging detectable anthropogenic influence (according to four or five of nine models) is found in the north-central U.S., where winter-spring streamflows have been coming earlier. Weaker indications of detectable anthropogenic influence (three of nine models) are found in the mountainous western U.S./southwestern Canada and in extreme northeastern U.S./Canadian Maritimes. In the former region, a recent shift toward later streamflows has rendered the full-record trend toward earlier streamflows only marginally significant, with possible implications for previously published climate change detection findings for streamflow timing in this region. In the latter region, no forced model shows as large a shift toward earlier streamflow timing as the detectable observed shift. In other (including warm, snow-free) regions, observed trends are typically not detectable, although in the U.S. central plains we find detectable delays in streamflow, which are inconsistent with forced model experiments.

Feed in summer, rest in winter: microbial carbon utilization in forest topsoil.

Science.gov (United States)

Žifčáková, Lucia; Větrovský, Tomáš; Lombard, Vincent; Henrissat, Bernard; Howe, Adina; Baldrian, Petr

2017-09-18

Evergreen coniferous forests contain high stocks of organic matter. Significant carbon transformations occur in litter and soil of these ecosystems, making them important for the global carbon cycle. Due to seasonal allocation of photosynthates to roots, carbon availability changes seasonally in the topsoil. The aim of this paper was to describe the seasonal differences in C source utilization and the involvement of various members of soil microbiome in this process. Here, we show that microorganisms in topsoil encode a diverse set of carbohydrate-active enzymes, including glycoside hydrolases and auxiliary enzymes. While the transcription of genes encoding enzymes degrading reserve compounds, such as starch or trehalose, was high in soil in winter, summer was characterized by high transcription of ligninolytic and cellulolytic enzymes produced mainly by fungi. Fungi strongly dominated the transcription in litter and an equal contribution of bacteria and fungi was found in soil. The turnover of fungal biomass appeared to be faster in summer than in winter, due to high activity of enzymes targeting its degradation, indicating fast growth in both litter and soil. In each enzyme family, hundreds to thousands of genes were typically transcribed simultaneously. Seasonal differences in the transcription of glycoside hydrolases and auxiliary enzyme genes are more pronounced in soil than in litter. Our results suggest that mainly fungi are involved in decomposition of recalcitrant biopolymers in summer, while bacteria replace them in this role in winter. Transcripts of genes encoding enzymes targeting plant biomass biopolymers, reserve compounds and fungal cell walls were especially abundant in the coniferous forest topsoil.

Minthorn Springs Creek summer juvenile release and adult collection facility: Annual report 1992; ANNUAL

International Nuclear Information System (INIS)

Rowan, Gerald D.

1993-01-01

The Confederated Tribes of the Umatilla Indian Reservation (CT'UIR) and Oregon Department of Fish and Wildlife (ODFW) are cooperating in a joint effort to supplement steelhead and re-establish salmon runs in the Umatilla River Basin. As an integral part of this program, Bonifer and Minthorn Acclimation Facilities are operated for holding and spawning adult steelhead and fall chinook salmon and acclimation and release of juvenile salmon and steelhead. Acclimation of 109,101 spring chinook salmon and 19,977 summer steelhead was completed at Bonifer in the spring of 1992. At Minthorn, 47,458 summer steelhead were acclimated and released. Control groups of spring chinook salmon were released instream concurrent with the acclimated releases to evaluate the effects of acclimation on adult returns to the Umatilla River. Acclimation studies with summer steelhead were not conducted in 1992. A total of 237 unmarked adult steelhead were collected for broodstock at Three Mile Dam from October 18, 1991 through April 24, 1992 and held at Minthorn. Utilizing a 3 x 3 spawning matrix, a total of 476,871 green eggs were taken from 86 females. The eggs were transferred to Umatilla Hatchery for incubation, rearing, and later release into the Umatilla River. A total of 211 fall chinook salmon were also collected for broodstock at Three Mile Dam and held at Minthorn. Using a 1:1 spawning ratio, a total of 195,637 green eggs were taken from 58 females. They were also transferred to Umatilla Hatchery for incubation, rearing, and later release into the Umatilla River. Personnel from the ODFW Eastern Oregon Fish Pathology Laboratory in La Grande took samples of tissues and reproductive fluids from Umatilla River summer steelhead and fall chinook salmon broodstock for monitoring and evaluation purposes. Cell culture assays for replicating agents, including IHNV virus, on all spawned fish were negative. One of 60 summer steelhead tested positive for EIBS virus, while all fall chinook tested

Pollution characteristic of VOCs of ambient air in winter and spring in Shijiazhuang City

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Qing CHANG

2015-06-01

Full Text Available In order to further explore the pollution characteristics of volatile organic compounds in ambient air in winter and spring in Shijiazhuang City, the pollution characteristics of 62 volatile organic compounds (VOCs, monthly and quarterly variation, the correlation between VOCs and PM2.5, and the main sources of VOCs are investigated by using EPA TO-15 method. It shows that 40 organic compounds of the 64 VOCs have been quantitatively determined in winter and spring in the city, which are mainly acetone, benzene, carbon tetrachloride, dichloromethane, toluene, ethyl acetate, etc.. In the no-quantitatively determined components, higher ethanol, butyl acetate, butane etc. are detected. The VOCs concentration has positive correlation with the PM2.5 concentration during haze days.

Fish Larvae Response to Biophysical Changes in the Gulf of California, Mexico (Winter-Summer

Directory of Open Access Journals (Sweden)

Raymundo Avendaño-Ibarra

2013-01-01

Full Text Available We analyzed the response of fish larvae assemblages to environmental variables and to physical macro- and mesoscale processes in the Gulf of California, during four oceanographic cruises (winter and summer 2005 and 2007. Physical data of the water column obtained through CTD casts, sea surface temperature, and chlorophyll a satellite imagery were used to detect mesoscale structures. Zooplankton samples were collected with standard Bongo net tows. Fish larvae assemblages responded to latitudinal and coastal-ocean gradients, related to inflow of water to the gulf, and to biological production. The 19°C and 21°C isotherms during winter, and 29°C and 31°C during summer, limited the distribution of fish larvae at the macroscale. Between types of eddy, the cyclonic (January registered high abundance, species richness, and zooplankton volume compared to the other anticyclonic (March and cyclonic (September. Thermal fronts (Big Islands of January and July affected the species distribution establishing strong differences between sides. At the mesoscale, eddy and fronts coincided with the isotherms mentioned previously, playing an important role in emphasizing the differences among species assemblages. The multivariate analysis indicated that larvae abundance was highly correlated with temperature and salinity and with chlorophyll a and zooplankton volume during winter and summer, respectively.

Hydroacoustic Evaluation of Overwintering Summer Steelhead Fallback and Kelt Passage at The Dalles Dam Turbines, Early Spring 2011

Energy Technology Data Exchange (ETDEWEB)

Khan, Fenton; Royer, Ida M.

2012-02-01

This report presents the results of an evaluation of overwintering summer steelhead (Oncorhynchus mykiss) fallback and early out-migrating steelhead kelts downstream passage at The Dalles Dam turbines during early spring 2011. The study was conducted by Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers, Portland District (USACE) to investigate whether adult steelhead are passing through turbines during early spring before annual sluiceway operations typically begin. The sluiceway surface flow outlet is the optimal non-turbine route for adult steelhead, although operating the sluiceway reduces hydropower production. This is a follow-up study to similar studies of adult steelhead passage at the sluiceway and turbines we conducted in the fall/winter 2008, early spring 2009, fall/winter 2009, and early spring 2010. The goal of the 2011 study was to characterize adult steelhead passage rates at the turbines while the sluiceway was closed so fisheries managers would have additional information to use in decision-making relative to sluiceway operations. Sluiceway operations were not scheduled to begin until April 10, 2011. However, based on a management decision in late February, sluiceway operations commenced on March 1, 2011. Therefore, this study provided estimates of fish passage rates through the turbines, and not the sluiceway, while the sluiceway was open. The study period was March 1 through April 10, 2011 (41 days total). The study objective was to estimate the number and distribution of adult steelhead and kelt-sized targets passing into turbine units. We obtained fish passage data using fixed-location hydroacoustics with transducers deployed at all 22 main turbine units at The Dalles Dam. Adult steelhead passage through the turbines occurred on 9 days during the study (March 9, 12, 30, and 31 and April 2, 3, 5, 7, and 9). We estimated a total of 215 {+-} 98 (95% confidence interval) adult steelhead targets passed through the

Winter-summer nutrient composition linkage to algae-produced toxins in shellfish at a eutrophic coastal lagoon (Óbidos lagoon, Portugal)

Science.gov (United States)

Pereira, Patrícia; Botelho, Maria João; Cabrita, Maria Teresa; Vale, Carlos; Moita, Maria Teresa; Gonçalves, Célia

2012-10-01

The current work examines the linkage of pronounced winter-summer fluctuations on the nutrient composition with phytoplankton assemblages and mussel toxicity produced by the presence of toxic dinoflagellates. The work was performed at the Óbidos lagoon, a coastal eutrophic ecosystem that is permanently connected to an area characterized by frequent upwelling episodes. The lagoon and adjoining coastal area exhibit recurrent incidents of diarrhetic and paralytic shellfish poisoning. The conclusions are based on: (1) inorganic and organic nutrients at five sites of the lower, middle and upper Óbidos lagoon, and inorganic nutrients at two sites of the adjacent coastal area; biannual campaigns were performed in winter and summer between 2006 and 2010; (2) phytoplankton assemblages at three sites of the lagoon (located at lower and upper areas) in winter and summer of 2009; (3) algae-derived toxicity of wild mussels from the lower lagoon and coastal area, on a 1-2 week time scale, over 2006 and 2009. Nutrient molar ratios in Óbidos lagoon contrast between winter and summer. The lower median ratios DIN:P (31 and 0.8) and Si:P (11 and 3.3) in summer reflect the excess of phosphate. Excess was mainly attributed to phosphorus regeneration in sediments of the upper lagoon with accentuated symptoms of eutrophication. Dissolved organic nitrogen and dissolved organic phosphorus were also higher in summer, particularly in this area. No significant winter-summer differences were recorded for nutrient ratios in the adjacent coastal area. Phytoplankton assemblages pointed to a winter-summer contrast characterized by a shift of non-siliceous-based phytoplankton to diatoms. The toxic dinoflagellate species (Gymnodinium catenatum, Dinophysis cf. acuminata and Dinophysis acuta), presumably imported from the adjacent coast following upwelling episodes in summer, were observed in the lower lagoon. In summer of the two surveyed years, toxins produced by dinoflagellates occurred in

Winter sea ice export from the Laptev Sea preconditions the local summer sea ice cover and fast ice decay

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P. Itkin

2017-10-01

Full Text Available Ice retreat in the eastern Eurasian Arctic is a consequence of atmospheric and oceanic processes and regional feedback mechanisms acting on the ice cover, both in winter and summer. A correct representation of these processes in numerical models is important, since it will improve predictions of sea ice anomalies along the Northeast Passage and beyond. In this study, we highlight the importance of winter ice dynamics for local summer sea ice anomalies in thickness, volume and extent. By means of airborne sea ice thickness surveys made over pack ice areas in the south-eastern Laptev Sea, we show that years of offshore-directed sea ice transport have a thinning effect on the late-winter sea ice cover. To confirm the preconditioning effect of enhanced offshore advection in late winter on the summer sea ice cover, we perform a sensitivity study using a numerical model. Results verify that the preconditioning effect plays a bigger role for the regional ice extent. Furthermore, they indicate an increase in volume export from the Laptev Sea as a consequence of enhanced offshore advection, which has far-reaching consequences for the entire Arctic sea ice mass balance. Moreover we show that ice dynamics in winter not only preconditions local summer ice extent, but also accelerate fast-ice decay.

Linking Regional Winter Sea Ice Thickness and Surface Roughness to Spring Melt Pond Fraction on Landfast Arctic Sea Ice

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Sasha Nasonova

2017-12-01

Full Text Available The Arctic sea ice cover has decreased strongly in extent, thickness, volume and age in recent decades. The melt season presents a significant challenge for sea ice forecasting due to uncertainty associated with the role of surface melt ponds in ice decay at regional scales. This study quantifies the relationships of spring melt pond fraction (fp with both winter sea ice roughness and thickness, for landfast first-year sea ice (FYI and multiyear sea ice (MYI. In 2015, airborne measurements of winter sea ice thickness and roughness, as well as high-resolution optical data of melt pond covered sea ice, were collected along two ~5.2 km long profiles over FYI- and MYI-dominated regions in the Canadian Arctic. Statistics of winter sea ice thickness and roughness were compared to spring fp using three data aggregation approaches, termed object and hybrid-object (based on image segments, and regularly spaced grid-cells. The hybrid-based aggregation approach showed strongest associations because it considers the morphology of the ice as well as footprints of the sensors used to measure winter sea ice thickness and roughness. Using the hybrid-based data aggregation approach it was found that winter sea ice thickness and roughness are related to spring fp. A stronger negative correlation was observed between FYI thickness and fp (Spearman rs = −0.85 compared to FYI roughness and fp (rs = −0.52. The association between MYI thickness and fp was also negative (rs = −0.56, whereas there was no association between MYI roughness and fp. 47% of spring fp variation for FYI and MYI can be explained by mean thickness. Thin sea ice is characterized by low surface roughness allowing for widespread ponding in the spring (high fp whereas thick sea ice has undergone dynamic thickening and roughening with topographic features constraining melt water into deeper channels (low fp. This work provides an important contribution towards the parameterizations of fp in

Comparing summer and winter indoor radon and radon daughters activity in Campinas, Brazil

International Nuclear Information System (INIS)

Guedes, O.S.; Hadler, N.J.C.; Iunes, P.J.; Neman, R.S.; Souza, W.F.; Tello, S.C.A.; Paulo, S.R.

2002-01-01

We developed a technique - based on alpha particle track detection using CR-39 - where the activity originated from indoor radon can be potentially separated into three fraction: (i) radon in the air, (ii) radon daughters (RD), 218 Po and 214 Po, in the air and (iii) RD plated-out on the detector surface during exposure. In this work only a partial separation was carried out, then our results are limited to radon plus RD in the air and RD attached to detector surface. These activities can be separated if size and gray level of the round tracks are measured using an automatic optical microscopy system.Our group carried out an indoor radon and radon daughters (RD) survey in Campinas made up by a summer (November, 96 to May, 97) and a winter (May, 97 to November, 97) exposure, where the detectors were placed in the same rooms of the same dwellings (approximately 100) in both cases. Comparing winter and summer alpha activity for the detectors analyzed up to now, approximately 45 dwellings, we observed that: i) it seems that the source of radon is the material (brick and concrete mainly) making up walls, floor and ceiling of the dwellings, ii) there is no clear relationship between intensity of aeration and the activities measured in this work, and iii) the average ratio between winter and summer activity in the air (radon plus RD) is approximately equal to similar ratios observed in other countries, but for radon only. (author)

Evidence of the Lower Thermospheric Winter-to-Summer Circulation From SABER CO2 Observations

Science.gov (United States)

Qian, Liying; Burns, Alan; Yue, Jia

2017-10-01

Numerical studies have shown that there is a lower thermospheric winter-to-summer circulation that is driven by wave dissipation and that it plays a significant role in trace gas distributions in the mesosphere and lower thermosphere, and in the composition of the thermosphere. However, the characteristics of this circulation are poorly known. Direct observations of it are difficult, but it leaves clear signatures in tracer distributions. The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) onboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite has obtained CO2 concentration from 2002 to present. This data set, combined with simulations by the Whole Atmosphere Community Climate Model, provides an unprecedented opportunity to infer the morphology of this circulation in both the summer and winter hemispheres. Our study show that there exists a maximum vertical gradient of CO2 at summer high latitudes, driven by the convergence of the upwelling of the mesospheric circulation and the downwelling of the lower thermospheric circulation; in the winter hemisphere, the maximum vertical gradient of CO2 is located at a higher altitude, driven by the convergence of the upwelling of the lower thermospheric circulation and the downwelling of the solar-driven thermospheric circulation; the bottom of the lower thermospheric circulation is located between 95 km and 100 km, and it has a vertical extent of 10 km. Analysis of the SABER CO2 and temperature at summer high latitudes showed that the bottom of this circulation is consistently higher than the mesopause height by 10 km.

Phenology of abundance of bivalve spat and of their epibenthic predators: limited evidence for mismatches after cold winters

NARCIS (Netherlands)

Dekker, R.; Beukema, J.J.

2014-01-01

Annual recruitment of bivalves in the Wadden Sea is usually more successful in summers after cold than after mild winters. The new generation (0-group) of the main predators (shrimps and shore crabs) of early benthic stages of bivalves appear later in spring on tidal flats after colder winters. If

Winter-to-Summer Precipitation Phasing in Southwestern North America: A Multi-Century Perspective from Paleoclimatic Model-Data Comparisons

Science.gov (United States)

Coats, Sloan; Smerdon, Jason E.; Seager, Richard; Griffin, Daniel; Cook, Benjamin I.

2015-01-01

The phasing of winter-to-summer precipitation anomalies in the North American monsoon (NAM) region 2 (113.25 deg W-107.75 deg W, 30 deg N-35.25 deg N-NAM2) of southwestern North America is analyzed in fully coupled simulations of the Last Millennium and compared to tree ring reconstructed winter and summer precipitation variability. The models simulate periods with in-phase seasonal precipitation anomalies, but the strength of this relationship is variable on multidecadal time scales, behavior that is also exhibited by the reconstructions. The models, however, are unable to simulate periods with consistently out-of-phase winter-to-summer precipitation anomalies as observed in the latter part of the instrumental interval. The periods with predominantly in-phase winter-to-summer precipitation anomalies in the models are significant against randomness, and while this result is suggestive of a potential for dual-season drought on interannual and longer time scales, models do not consistently exhibit the persistent dual-season drought seen in the dendroclimatic reconstructions. These collective findings indicate that model-derived drought risk assessments may underestimate the potential for dual-season drought in 21st century projections of hydroclimate in the American Southwest and parts of Mexico.

Spring Arctic Oscillation-East Asian summer monsoon connection through circulation changes over the western North Pacific

Energy Technology Data Exchange (ETDEWEB)

Gong, Dao-Yi; Yang, Jing; Hu, Miao [Beijing Normal University, State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing (China); Kim, Seong-Joong [Korea Polar Research Institute, Incheon (Korea, Republic of); Gao, Yongqi [Nansen-Zhu International Research Center, IAP/CAS, Beijing (China); Nansen Environmental and Remote Sensing Center/Bjerknes Center for Climate Research, Bergen (Norway); Guo, Dong [Beijing Normal University, State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing (China); Nansen-Zhu International Research Center, IAP/CAS, Beijing (China); Zhou, Tianjun [State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), IAP/CAS, Beijing (China)

2011-12-15

In the present study the links between spring Arctic Oscillation (AO) and East Asian summer monsoon (EASM) was investigated with focus on the importance of the North Pacific atmospheric circulation and sea surface temperature (SST). To reduce the statistical uncertainty, we analyzed high-pass filtered data with the inter-annual time scales, and excluded the El Nino/Southern Oscillation signals in the climate fields using a linear fitting method. The significant relationship between spring AO and EASM are supported by the changes of multi-monsoon components, including monsoon indices, precipitation, and three-dimensional atmospheric circulations. Following a stronger positive spring AO, an anomalous cyclonic circulation at 850 hPa appears in southeastern Asia and the western North Pacific in summer, with the easterly anomalies spanning from the Pacific to Asian continent along 25 N-30 N and the westerly anomalies south of 15 N. At the same time, the summer western North Pacific subtropical high becomes weaker. Consistently, the positive precipitation anomalies are developed over a broad region south of 30 N stretching from southern China to the western Pacific and the negative precipitation anomalies appear in the lower valley of the Yangtze River and southern Japan. The anomalous cyclone in the western North Pacific persisting from spring to summer plays a key role in modulating EASM and monsoon precipitation by a positive air-sea feedback mechanism. During spring the AO-associated atmospheric circulation change produces warmer SSTs between 150 E-180 near the equator. The anomalous sensible and latent heating, in turn, intensifies the cyclone through a Gill-type response of the atmosphere. Through this positive feedback, the tropical atmosphere and SST patterns sustain their strength from spring to summer, that consequently modifies the monsoon trough and the western North Pacific subtropical high and eventually the EASM precipitation. Moreover, the SST response to

Winter and spring diving behavior of bowhead whales relative to prey

KAUST Repository

Heide-Jø rgensen, Mads; Laidre, Kristin L; Nielsen, Nynne H; Hansen, Rikke G; Rø stad, Anders

2013-01-01

There was a marked change in diving behavior from winter through spring and this was likely in response to the changes in sea ice conditions, primary production and potential copepod abundance in the upper part of the water column. Depth and duration of dives changed significantly during this period; however, other dive parameters (for example the proportion of time spent feeding on the bottom of U-dives) remained fairly constant indicating a constant feeding effort. Bowhead whales target copepods at or close to the seabed in winter months in Disko Bay and continue feeding on copepods when they migrate to the surface. However, bowhead whales leave West Greenland before peak abundance of copepods occurs at the surface.

Application and Study of Precipitation Schemes in Weather Simulation in Summer and Winter over China

Institute of Scientific and Technical Information of China (English)

XU Guoqiang; WAN Qilin; HUANG Liping; XUE Jishan; CHEN Dehui

2006-01-01

Through simulation of summer and winter precipitation cases in China, the cloud precipitation schemes of model were examined. Results indicate that it is discrepant between convective precipitation simulated by the Kain-Fritsch (KF) scheme and Betts-Miller (BM) scheme in summer, the former scheme is better than the latter in this case. The ambient atmosphere may be varied by different convective schemes. The air is wetter and the updraft is stronger in the KF scheme than in the BM scheme, which can induce the more grid scale precipitation in the KF scheme, i.e., the different cumulus schemes may have the different and important effect on the grid scale precipitation. However, there is almost no convective rain in winter in northern China, so the effect of cumulus precipitation on the grid scale precipitation can be disregarded.Therefore, the gird scale precipitation is primary in the winter of northern China.

To Everything There Is a Season: Summer-to-Winter Food Webs and the Functional Traits of Keystone Species.

Science.gov (United States)

Humphries, Murray M; Studd, Emily K; Menzies, Allyson K; Boutin, Stan

2017-11-01

From a trophic perspective, a seasonal increase in air temperature and photoperiod propagates as bottom-up pulse of primary production by plants, secondary production by herbivores, and tertiary production by carnivores. However, food web seasonality reflects not only abiotic variation in temperature and photoperiod, but also the composition of the biotic community and their functional responses to this variation. Some plants and animals-here referred to as seasonal specialists-decouple from food webs in winter through migration or various forms of metabolic arrest (e.g., senescence, diapause, and hibernation), whereas some plants and resident animals-here referred to as seasonal generalists-remain present and trophically coupled in winter. The co-occurrence of species with divergent responses to winter introduces seasonal variation in interaction strengths, resulting in summer-to-winter differences in trophic organization. Autumn cooling and shortening day length arrests primary productivity and cues seasonal herbivores to decouple, leaving generalist carnivores to concentrate their predation on the few generalist herbivores that remain resident, active, and vulnerable to predation in winter, which themselves feed on the few generalist plant structures available in winter. Thus, what was a bottom-up pulse, spread among many species in summer, including highly productive seasonal specialists, reverses into strong top-down regulation in winter that is top-heavy, and concentrated among a small number of generalist herbivores and their winter foods. Intermediate-sized, generalist herbivores that remain active and vulnerable to predation in winter are likely to be keystone species in seasonal food webs because they provide the essential ecosystem service of turning summer primary productivity into winter food for carnivores. Empirical examination of terrestrial mammals and their seasonal trophic status in the boreal forest and across an arctic-to-tropics seasonality

Composition of Sinking Particulates Collected under Fast Ice near Syowa Station, East Antarctica, in Early Spring and Early Summer, 1994

Directory of Open Access Journals (Sweden)

Ryoko Saito

1998-11-01

Full Text Available Sinking particles collected in several sediment trap experiments near Syowa Station in austral spring-summer in 1994 have been microscopically analyzed. From the features of the shape and morphology, collected particles were identified, enumerated and measured, and the flux of each identified species was estimated. The majority of the particles were composed of diatom cells and "fecal pellet"-like aggregates were recognized in the samples. In spring, the particle fluxes were rather low and higher fluxes were detected in summer. In particular, diatom cell flux increased by two order of magnitude. The composition of the sinking particles varied seasonally; a centric diatom, Corethron criophilum, and round-shape fecal pellets accounted for dominant diatom cell and fecal pellet fluxes in the spring. But pennate diatoms and collumn-shape pellets dominated in summer. The vertical flux varied, too. In spite of the significant difference of total bio-volume flux between spring and summer (>30 times higher in summer, the bio-volume ratio, such as total identified diatoms and fecal pellets, stayed rather constant.

Impacts of climate change for Swiss winter and summer tourism: a general equilibrium analysis

OpenAIRE

Thurm, Boris; Vielle, Marc; Vöhringer, Frank

2017-01-01

Tourism could be greatly affected by climate change due to its strong dependence on weather. In Switzerland, the sector represents an appreciable share of the economy. Thus, studying climate effects on tourism is necessary for developing adequate adaptation strategies. While most of the studies focused on winter tourism, we investigate the climate change impacts on both winter and summer tourism in Switzerland. Using a computable general equilibrium (CGE) model, we simulate the impacts of tem...

The Promotion of HAMK Winter and Summer Camps: Case China

OpenAIRE

Lin, Yulu

2017-01-01

The main purpose of this thesis is to promote HAMK winter and summer camps in China and maintain its competitive advantages by figuring out more effective marketing activities to attract students. The theories used to support and give references to this thesis were based on the research and studies from Philip Kotler, Kevin Keller and Armstrong. Some marketing related books such as Principles of Marketing or Marketing Management proved to be professional sources and explanations for conce...

Winter Insulation By Snow Accumulation in a Subarctic Treeline Ecosystem Increases Summer Carbon Cycling Rates

Science.gov (United States)

Parker, T.; Subke, J. A.; Wookey, P. A.

2014-12-01

The effect of snow accumulation on soil carbon and nutrient cycling is attracting substantial attention from researchers. We know that deeper snow accumulation caused by high stature vegetation increases winter microbial activity and therefore carbon and nitrogen flux rates. However, until now the effect of snow accumulation, by buffering winter soil temperature, on subsequent summer soil processes, has scarcely been considered. We carried out an experiment at an alpine treeline in subarctic Sweden in which soil monoliths, contained within PVC collars, were transplanted between forest (deep winter snow) and tundra heath (shallow winter snow). We measured soil CO2efflux over two growing seasons and quantified soil microbial biomass after the second winter. We showed that respiration rates of transplanted forest soil were significantly reduced compared with control collars (remaining in the forest) as a consequence of colder, but more variable, winter temperatures. We hypothesised that microbial biomass would be reduced in transplanted forests soils but found there was no difference compared to control. We therefore further hypothesised that the similarly sized microbial pool in the control is assembled differently to the transplant. We believe that the warmer winters in forests foster more active consortia of decomposer microbes as a result of different abiotic selection pressures. Using an ecosystem scale experimental approach, we have identified a mechanism that influences summer carbon cycling rates based solely on the amount of snow that accumulates the previous winter. We conclude that modification of snow depth as a consequence of changes in vegetation structure is an important mechanism influencing soil C stocks in ecosystems where snow persists for a major fraction of the year.

Sex-specific responses to winter flooding, spring waterlogging and post-flooding recovery in Populus deltoides

OpenAIRE

Ling-Feng Miao; Fan Yang; Chun-Yu Han; Yu-Jin Pu; Yang Ding; Li-Jia Zhang

2017-01-01

Winter flooding events are common in some rivers and streams due to dam constructions, and flooding and waterlogging inhibit the growth of trees in riparian zones. This study investigated sex-specific morphological, physiological and ultrastructural responses to various durations of winter flooding and spring waterlogging stresses, and post-flooding recovery characteristics in Populus deltoides. There were no significant differences in the morphological, ultrastructural and the majority of ph...

Melanopsin-Mediated Acute Light Responses Measured in Winter and in Summer: Seasonal Variations in Adults with and without Cataracts

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Mirjam Münch

2017-09-01

Full Text Available Seasonal adaptation is a ubiquitous behavior seen in many species on both global hemispheres and is conveyed by changing photoperiods. In humans this seasonal adaptation is less apparent, in part because changes in daylength are masked by the use of electrical lighting at night. On the other hand, cataracts which reduce light transmission, may compound seasonal changes related to the reduced daylength of winter. To better understand the effects of different photoperiod lengths in healthy adults without and with cataracts, we tested their melanopsin-mediated light responses in summer vs. winter. Fifty-two participants (mean age 67.4 years; 30 with bilateral cataracts and 22 age-matched controls with clear lenses; pseudophakes were tested twice, once in summer and once in winter. At each test session we assessed the electroretinogram and pupil responses during daytime and we determined melatonin suppression, subjective sleepiness and mood in response to light exposure in the evening. Circadian rest-activity cycles and sleep from activity recordings were also analyzed for both seasons. Both groups had similar visual function. There were no seasonal differences in the electroretinogram. For the pupil responses to bright blue light, the post-illumination pupil response (PIPR was greater in winter than summer in pseudophakes, but not in cataract participants, whereas melatonin suppression to acute light exposure showed no differences between both groups and seasons. Overall, intra-daily variability of rest-activity was worse in winter but participants felt sleepier and reported worse mood at the laboratory in evening time in the summer. Those with cataracts had poorer sleep quality with lower sleep efficiency, and higher activity during sleep in winter than summer. In this study, the PIPR showed a seasonal variation in which a larger response was found during winter. This variation was only detected in participants with a clear intraocular lens. In

Estimation of N2 fixation in winter and spring sown chickpea and in lentil grown under rainfed conditions using 15 N

International Nuclear Information System (INIS)

Kurdali, F.; Khalifa, Kh.; Al-Asfari, F.

1996-03-01

A field experiment was conducted under rainfed conditions to asses N 2 fixation in one cultivar of lentil and in two cultivars of chickpea (Gab 1 for winter and spring sowing, and Baladi for spring sowing). Moreover, the effect of P fertilizer on dry matter production, percentages and amounts of different N sources was studied using 15 N isotope dilution method. Wheat was used as a reference crop. The rate of N 2 fixation affected by several factors such as plant species, cultivar, date of sowing, P-fertilizer and the growing season. The highest amount of N 2 fixation obtained in winter sown chickpea was 126 Kg N ha -1 . Whereas, that of spring sowing for the same cultivar was 30 Kg N ha -1 . For Baladi cultivar, the highest amount of N-fixed was 55 Kg N ha -1 . While it was 104 Kg N ha -1 in lentil. Generally, N 2 -fixation affected positively by P-application. In the first growing season, N 2 -fixation increased from 33 to %58 by P application in spring sown chickpea (Baladi), and from 20 to %35 in spring sown chickpea (Gab 1). Whereas, no significant differences were observed upon P application in winter sown chickpea and in lentil. In the second growing season, P-fertilizer increased the percentage of N 2 fixation from 54 to %64 in winter sown chickpea, and from 45 to %64 in spring sown chickpea (Gab 1), and from 49 to %60 in spring sown chickpea (Baladi). While, in lentil it was from 66 to %72. The rate of N 2 fixation in winter sown chickpea was clearly higher than that of spring sowings. Moreover, this last one absorbed more N from the soil. Our results indicate the importance of winter sown chickpea in terms of N 2 fixation, seed yield and the reduction of soil N-uptake, besides a positive P-fertilizer response, especially when suitable rain fall occurs during the season. Moreover, the importance of these results from agronomical point of view was discussed. (author). 24 refs., 6 figs., 7 tabs

Ischemic Heart Disease Hospitalization among Older People in a Subtropical City — Hong Kong: Does Winter Have a Greater Impact than Summer?

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Pui Hing Chau

2014-04-01

Full Text Available Globally, excess winter morbidity from ischemic heart disease (IHD is reported. In subtropical regions, there is a need to quantify the difference in the adverse effect of cold winters compared with hot summers, particularly among the older people. Our objectives were to: (i compare the effect of winter on IHD hospitalizations with that of summer; (ii examine temporal trends in the excess winter hospitalizations; and (iii investigate the effect of age, gender, and meteorological factors on predicting such excess. Inpatient admissions due to IHD as principal cause during June 2000 to February 2009 in public hospitals of Hong Kong were extracted for the population aged ≥65. An Excess Hospitalization in Winter vs. Summer (EHWS Index was used to contrast the adverse effect of weather on hospitalizations in winter vs. summer. Multiple linear regressions were used to investigate the trend and the predictors of such index. It was found that in a subtropical city, greater effect of winter on IHD hospitalizations than summer was observed, particularly among the oldest old (an index of 61.5% (95% CI: 49.5%–74.4% for men aged ≥85 and 32.3% (95% CI: 25.5%–39.5% for women aged ≥85. There was significant increasing trend in the index among those aged ≥85 but the age difference was less prominent among the women. Absolute level of coldness was not a significant factor, whereas the change in temperature was a significant factor, which implies that great fluctuation in temperature within a winter day had greater impact on occurrence of circulatory disease than an absolute temperature threshold.

Hood River Production Program Monitoring and Evaluation (M&E) - Confederated Tribes of Warm Springs : Annual Report For Fiscal Year, October 2007 – September 2008.

Energy Technology Data Exchange (ETDEWEB)

Gerstenberger, Ryan [Confederated Tribes of Warm Springs Reservation

2009-07-27

This progress report describes work performed by the Confederated Tribes of Warm Springs (CTWSRO) portion of the Hood River Production Program Monitoring and Evaluation Project (HRPP) during the 2008 fiscal year. A total of 64,736 hatchery winter steelhead, 12,108 hatchery summer steelhead, and 68,426 hatchery spring Chinook salmon smolts were acclimated and released in the Hood River basin during the spring. The HRPP exceeded program goals for a release of and 50,000 winter steelhead but fell short of the steelhead release goals of 30,000 summer steelhead and 75,000 spring Chinook in 2008. Passive Integrated Transponders (PIT) tags were implanted in 6,652 hatchery winter steelhead, and 1,196 hatchery summer steelhead, to compare migratory attributes and survival rates of hatchery fish released into the Hood River. Water temperatures were recorded at six locations within the Hood River subbasin to monitor for compliance with Oregon Department of Environmental Quality water quality standards. A preseason spring Chinook salmon adult run forecast was generated, which predicted an abundant return adequate to meet escapement goal and brood stock needs. As a result the tribal and sport fisheries were opened. A tribal creel was conducted from May 22 to July 18 during which an estimated 172 spring Chinook were harvested. One hundred sixteen Spring Chinook salmon redds were observed and 72 carcasses were inspected on 19.4 miles of spawning grounds throughout the Hood River Basin during 2008. Annual salvage operations were completed in two irrigation canals resulting in the liberation of 1,641 fish back to the Hood River.

Dynamics of sea-ice biogeochemistry in the coastal Antarctica during transition from summer to winter

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Suhas Shetye

2017-05-01

Full Text Available The seasonality of carbon dioxide partial pressure (pCO2, air-sea CO2 fluxes and associated environmental parameters were investigated in the Antarctic coastal waters. The in-situ survey was carried out from the austral summer till the onset of winter (January 2012, February 2010 and March 2009 in the Enderby Basin. Rapid decrease in pCO2 was evident under the sea-ice cover in January, when both water column and sea-ice algal activity resulted in the removal of nutrients and dissolved inorganic carbon (DIC and increase in pH. The major highlight of this study is the shift in the dominant biogeochemical factors from summer to early winter. Nutrient limitation (low Si/N, sea-ice cover, low photosynthetically active radiation (PAR, deep mixed layer and high upwelling velocity contributed towards higher pCO2 during March (early winter. CO2 fluxes suggest that the Enderby Basin acts as a strong CO2 sink during January (−81 mmol m−2 d−1, however it acts as a weak sink of CO2 with −2.4 and −1.7 mmol m−2 d−1 during February and March, respectively. The present work, concludes that sea ice plays a dual role towards climate change, by decreasing sea surface pCO2 in summer and enhancing in early winter. Our observations emphasize the need to address seasonal sea-ice driven CO2 flux dynamics in assessing Antarctic contributions to the global oceanic CO2 budget.

Aerosol optical properties measurements by a CAPS single scattering albedo monitor: Comparisons between summer and winter in Beijing, China

Science.gov (United States)

Han, Tingting; Xu, Weiqi; Li, Jie; Freedman, Andrew; Zhao, Jian; Wang, Qingqing; Chen, Chen; Zhang, Yingjie; Wang, Zifa; Fu, Pingqing; Liu, Xingang; Sun, Yele

2017-02-01

Aerosol optical properties were measured in Beijing in summer and winter using a state-of-the-art cavity attenuated phase shift single scattering albedo monitor (CAPS PMssa) along with aerosol composition measurements by aerosol mass spectrometers and aethalometers. The SSA directly measured by the CAPS PMssa showed overall agreements with those derived from colocated measurements. However, substantial differences were observed during periods with low SSA values in both summer and winter, suggesting that interpretation of low SSA values needs to be cautious. The average (±σ) extinction coefficient (bext) and absorption coefficient (bap) were 336 (±343) Mm-1 and 44 (±41) Mm-1, respectively, during wintertime, which were approximately twice those observed in summer, while the average SSA was relatively similar, 0.86 (±0.06) and 0.85 (±0.04) in summer and winter, respectively. Further analysis showed that the variations in SSA can be approximately parameterized as a function of mass fraction of secondary particulate matter (fSPM), which is SSA = 0.74 + 0.19 × fSPM (fSPM > 0.3, r2 = 0.85). The contributions of aerosol species to extinction coefficients during the two seasons were also estimated. Our results showed that the light extinction was dominantly contributed by ammonium sulfate (30%) and secondary organic aerosol (22%) in summer, while organic aerosol was the largest contributor (51%) in winter. Consistently, SPM played the major role in visibility degradation in both seasons by contributing 70% of the total extinction.

Determination of biological nitrogen fixation capacities of winter and spring lentil varieties by using ''1''5N methodology

International Nuclear Information System (INIS)

Akin, A.

2001-01-01

In order to determine the biological nitrogen fixation capacities of winter and spring varieties of lentil which have of agronomic importance under the Central Anatolia region, the field experiments (winter and spring) were carried out. In both experiments, the effects of two different iconoclasts and different harvesting times on the biological nitrogen fixation capacities of lentil varieties, were investigated. The field experiments were conducted using by randomized block design as split-split plot for 4 replications. Barley was selected as the reference crop and 20 cm row spacing were used for lentil and barley. Inoculations were done immediately before sowing. 10.0 kg N/ ha for lentil varieties as 10.0 % ''1''5N atom excess and 40.0 kg N/ ha for barley (reference crop) as 2.0 % ''1''5N atom excess ammonium sulphate fertilizer were applied. In addition, 60.0 kgP 2 O 5 / ha were applied as triple superphosphate for all treatments. Plants were harvested at the different growth stages and than plant materials prepared for the analysis. Total nitrogen and % ''1''5N atom excess analysis were done by Kjeldahl method and Emission spectrometer, respectively. The amount of nitrogen fixation capacities of winter and spring lentil varieties were calculated according to the A-Value method (IAEA 1990). The results showed us that the winter varieties of lentil had higher dry matter yields and nitrogen fixation capacities than the spring varieties. Inoculation treatments had no statistically significant effects on the percentage of nitrogen derived from atmosphere (% Ndfa) and the amount of fixed nitrogen (kg N/ ha) for both experiments. In comparison between the harvesting times, the highest amount of fixed nitrogen was found at the pod formation stage for all cultivars. The average amounts of % Ndfa and fixed nitrogen (kg N/ ha) were 75.0 and 70.0 for winter cultivars, 70.0 and 45.0 for spring cultivars, respectively

Intermittent fasting during winter and spring affects body composition and reproduction of a migratory duck

Science.gov (United States)

Barboza, P.S.; Jorde, Dennis G.

2002-01-01

We compared food intake, body mass and body composition of male and female black ducks (Anas rubripes) during winter (January-March). Birds were fed the same complete diet ad libitum on consecutive days each week without fasting (control; nine male; nine female) or with either short fasts (2 day.week-1; nine male; nine female), or long fasts (4 day.week-1; eleven male; twelve female). We continued treatments through spring (March-May) to measure the effect of intermittent fasts on body mass and egg production. Daily food intake of fasted birds was up to four times that of unfasted birds. Weekly food intake of males was similar among treatments (364 g.kg-1.week-1) but fasted females consumed more than unfasted females in January (363 g.kg-1.week-1 vs. 225 g.kg-1.week-1). Although both sexes lost 10-14% body mass, fasted females lost less mass and lipid than unfasted females during winter. Total body nitrogen was conserved over winter in both sexes even though the heart and spleen lost mass while the reproductive tract and liver gained mass. Intermittent fasting increased liver, intestinal tissue and digesta mass of females but not of males. Fasting delayed egg production in spring but did not affect size, fertility or hatching of the clutch. Females on long fasts were still heavier than controls after laying eggs. Thus black ducks combine flexibility of food intake with plasticity of digestive tract, liver and adipose tissue when food supply is interrupted during winter. Females modulate body mass for survival and defer reproduction when food supply is interrupted in spring.

Differential impacts of ocean acidification and warming on winter and summer progeny of a coastal squid (Loligo vulgaris).

Science.gov (United States)

Rosa, Rui; Trübenbach, Katja; Pimentel, Marta S; Boavida-Portugal, Joana; Faleiro, Filipa; Baptista, Miguel; Dionísio, Gisela; Calado, Ricardo; Pörtner, Hans O; Repolho, Tiago

2014-02-15

Little is known about the capacity of early life stages to undergo hypercapnic and thermal acclimation under the future scenarios of ocean acidification and warming. Here, we investigated a comprehensive set of biological responses to these climate change-related variables (2°C above winter and summer average spawning temperatures and ΔpH=0.5 units) during the early ontogeny of the squid Loligo vulgaris. Embryo survival rates ranged from 92% to 96% under present-day temperature (13-17°C) and pH (8.0) scenarios. Yet, ocean acidification (pH 7.5) and summer warming (19°C) led to a significant drop in the survival rates of summer embryos (47%, Pocean acidification and summer warming scenarios. The occurrence of prolonged embryogenesis along with lowered thermal tolerance limits under such conditions is expected to negatively affect the survival success of squid early life stages during the summer spawning period, but not winter spawning.

Bioaccumulation of metals in reeds collected from an acid mine drainage contaminated site in winter and spring.

Science.gov (United States)

Guo, Lin; Cutright, Teresa J

2016-01-01

Wetland plants such as Phragmites australis has been used to treat acid mine drainage (AMD) contaminated soil which is a serious environmental issue worldwide. This project investigated metal plaque content(s) and metal uptake in reeds grown in an AMD field in winter and spring. The results indicated that the level of Fe plaque was much higher than Mn and Al plaque as the soil contained more Fe than Al and Mn. The amounts of Mn and Al plaque formed on reeds in spring were not significantly different from that in winter (p > .05). However, more Fe plaque was formed on reeds collected in spring. The concentrations of metals in underground organs were positively related to the metal levels in soils. More Mn and Al transferred to the aboveground tissues of reeds during the spring while the Fe levels in reeds did not significantly vary with seasons. Roots and rhizomes were the main organs for Fe sequestration (16.3 ± 4.15 mg/g in roots in spring) while most Al was sequestered in the shoots of reeds (2.05 ± 0.09 mg/g in shoots in spring). Further research may be needed to enhance the translocation of metals in reeds and increase the phytoremediation efficiency.

ALOS PALSAR Winter Coherence and Summer Intensities for Large Scale Forest Monitoring in Siberia

Science.gov (United States)

Thiel, Christian; Thiel, Carolin; Santoro, Maurizio; Schmullius, Christiane

2008-11-01

In this paper summer intensity and winter coherence images are used for large scale forest monitoring. The intensities (FBD HH/HV) have been acquired during summer 2007 and feature the K&C intensity stripes [1]. The processing consisted of radiometric calibration, orthorectification, and topographic normalisation. The coherence has been estimated from interferometric pairs with 46-days repeat-pass intervals. The pairs have been acquired during the winters 2006/2007 and 2007/2008. During both winters suited weather conditions have been reported. Interferometric processing consisted of SLC co-registration at sub-pixel level, common-band filtering in range and azimuth and generation of a differential interferogram, which was used in the coherence estimation procedure based on adaptive estimation. All images were geocoded using SRTM data. The pixel size of the final SAR products is 50 m x 50 m. It could already be demonstrated, that by using PALSAR intensities and winter coherence forest and non-forest can be clearly separated [2]. By combining both data types hardly any overlap of the class signatures was detected, even though the analysis was conducted on pixel level and no speckle filter has been applied. Thus, the delineation of a forest cover mask could be executed operationally. The major hitch is the definition of a biomass threshold for regrowing forest to be distinguished as forest.

Winter-spring precipitation reconstructions from tree rings for northeast Mexico

Energy Technology Data Exchange (ETDEWEB)

Villanueva-Diaz, J.; Cerano-Paredes, J. [Instituto Nacional de Investigaciones Forestales y Agropecuarias, Centro Nacional de Investigacion Disciplinarioa en Relacion Agua, Suelo, Planta. Km 6.5 Margen Derecha del Canal Sacramento Gomez Palacio, Durango, 35140 (Mexico); Stahle, D.W.; Cleaveland, M.K. [Tree-Ring Laboratory, Department of Geosciences, University of Arkansas, fayetteville, Arkansas 72701 (United States); Luckman, B.H. [Department of Geography, University of Western Ontario, London, Ontario, N6A5C3 (Canada); Therrell, M.D. [Department of Environmental Sciences, University of Virginia, Charlottesville, VA 29904 (United States); Cornejo-Oviedo, E. [Departamento Forestal, Universidad Autonoma Agraria Antonio Narro, Saltillo, Coahuila (Mexico)

2007-07-15

The understanding of historic hydroclimatic variability is basic for planning proper management of limited water resources in northeastern Mexico. The objective of this study was to develop a network of tree-ring chronologies to reconstruct hydroclimate variability in northeastern Mexico and to analyze the influence of large-scale circulation patterns, such as ENSO. Precipitation sensitive tree-ring chronologies of Douglas-fir were developed in mountain ranges of the Sierra Madre Oriental and used to produce winter-spring precipitation reconstructions for central and southern Nuevo Leon, and southeastern Coahuila. The seasonal winter-spring precipitation reconstructions are 342 years long (1659-2001) for Saltillo, Coahuila and 602 years long (1400-2002) for central and southern Nuevo Leon. Both reconstructions show droughts in the 1810s, 1870s, 1890s, 1910s, and 1970s, and wet periods in the 1770s, 1930s, 1960s, and 1980s. Prior to 1800s the reconstructions are less similar. The impact of ENSO in northeastern Mexico (as measured by the Tropical Rainfall Index) indicated long-term instability of the Pacific equatorial teleconnection. Atmospheric circulation systems coming from higher latitudes (cold fronts or 'nortes') and others developed in the Gulf of Mexico (tropical storms, hurricanes) also influence the climatic conditions characterizing this region. The recent development of new and longer tree-ring chronologies for the region will contribute to a better understanding of the interannual and multidecadal climatic variability of northeastern Mexico.

Large-scale gene expression reveals different adaptations of Hyalopterus persikonus to winter and summer host plants.

Science.gov (United States)

Cui, Na; Yang, Peng-Cheng; Guo, Kun; Kang, Le; Cui, Feng

2017-06-01

Host alternation, an obligatory seasonal shifting between host plants of distant genetic relationship, has had significant consequences for the diversification and success of the superfamily of aphids. However, the underlying molecular mechanism remains unclear. In this study, the molecular mechanism of host alternation was explored through a large-scale gene expression analysis of the mealy aphid Hyalopterus persikonus on winter and summer host plants. More than four times as many unigenes of the mealy aphid were significantly upregulated on summer host Phragmites australis than on winter host Rosaceae plants. In order to identify gene candidates related to host alternation, the differentially expressed unigenes of H. persikonus were compared to salivary gland expressed genes and secretome of Acyrthosiphon pisum. Genes involved in ribosome and oxidative phosphorylation and with molecular functions of heme-copper terminal oxidase activity, hydrolase activity and ribosome binding were potentially upregulated in salivary glands of H. persikonus on the summer host. Putative secretory proteins, such as detoxification enzymes (carboxylesterases and cytochrome P450s), antioxidant enzymes (peroxidase and superoxide dismutase), glutathione peroxidase, glucose dehydrogenase, angiotensin-converting enzyme, cadherin, and calreticulin, were highly expressed in H. persikonus on the summer host, while a SCP GAPR-1-like family protein and a salivary sheath protein were highly expressed in the aphids on winter hosts. These results shed light on phenotypic plasticity in host utilization and seasonal adaptation of aphids. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Ground beetles (Coleoptera, Carabidae agrocenoses of spring and winter wheat

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Luboš Purchart

2005-01-01

Full Text Available On two monitoring areas of the Central Institute for Supervising and Testing in Agriculture (ÚKZÚZ loaded with risk elements we carried out investigations of beetles of the family Carabidae (Coleoptera in agricultural stands of winter and spring wheat. The focus of the present study is on synecological characteristics and in some extent on the impact of agricultural practise on the population and seasonal dynamics of the most important representatives of ground beetles. This paper precedes the following article aimed to contents of heavy metals in ground beetles.

Report of the 33rd Japanese Antarctic Research ExpeditionーActivities of the summer party(1991-1992and wintering party(1992ー

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Mitsuo Fukuchi

1996-03-01

Full Text Available Summer activities in the 1991/92 austral summer and winter activities in 1992 of the 33rd Japanese Antarctic Research Expedition (JARE are described. The JARE-33 consisted of 16 members of the summer party and 37 members of the wintering party (one member of the wintering party returned with the summer party. Two Brazilian fish physiologists joined the summer party based on the exchange scientist program of the Antarctic Treaty. The icebreaker SHIRASE left Tokyo on 14 November 1991 and arrived at Breid Bay on 18 December, where the closing of Asuka Camp was completed. Then she headed to Syowa Station and arrived there on 4 January 1992. Transportation of cargo by helicopter to Syowa Station was carried out between 23 December 1991 and 18 January 1992. A total of 848t of cargo, including pipe transport of light oil (342kl and freight by oversnow vehicles (215t, were transported. A new central building was constructed from 23 December to 17 February as the start of an 8-year reintegration project of Syowa Station. Three generator engines of 200kVA capacity were overhauled. Concurrently, various research programs such as absolute gravity measurement and field surveys including inland oversnow traverse were performed. However, there were some problems with a super conducting gravity meter while the gravity meter was being tested for winter operation. Therefore, one scientist working on the gravity meter who planned to winter-over decided to leave Syowa Station with the gravity meter. all of the summer party left Syowa Station on 17 February and headed to Sydney, Australia, while oceanographic and marine biological observations were carried out on board. Members of the summer party of JARE-33 and the wintering party of JARE-32 returned to Narita by air on 27 March 1992. The wintering party of JARE-33 worked at Syowa Station from 1 February 1992 to 31 January 1993. The scientific research programs cover the following four major disciplines : (1 upper

Late winter feeding stimulates rapid spring development of carniolan honey bee colonies (Apis mellifera carnica

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Zlatko Puškadija

2017-01-01

Full Text Available Unfavourable weather conditions after the queen starts with intensive oviposition during early spring may cause an imbalance in the division of tasks among worker bees in the bee colony. This can lead to slow spring development and poor exploitation of the main spring nectar flows. In order to accelerate the spring development, it is necessary, as a technological measure, to feed supplemental candy to bee colonies. In this research, the necessity of supplemental feeding, as well as the composition of candy (pollen and protein substitute were analysed. Three groups of ten bee colonies each were formed - the control, unfed group, pollen candy fed and protein substitute candy fed. In the period from 22/02/2016 and 04/04/2016 three control measurements were performed during which the number of bees, the number of brood cells and weight of the bee colonies were determined. The research has shown that supplemental feeding of the bee colony in late winter in order to encourage the rapid spring development is justified. Namely, at the final measurements in April, the results showed differences between groups. The treated colonies had higher net hive weight, a greater number of bees and statistically significantly more brood cells. The results of this study confirm that the technological measure of supplemental feeding in late winter should be performed on all commercial apiaries for the production of honey, pollen, royal jelly, queen bees and bee venom.

[Absorption and fluorescence characteristics of dissolved organic matter (DOM) in rainwater and sources analysis in summer and winter season].

Science.gov (United States)

Liang, Jian; Jiang, Tao; WeiI, Shi-Qiang; Lu, Song; Yan, Jin-Long; Wang, Qi-Lei; Gao, Jie

2015-03-01

This study aimed at evaluating the variability of the optical properties including UV-Vis and fluorescence characteristics of dissolved organic matter (DOM) from rainwater in summer and winter seasons. UV-Vis and fluorescence spectroscopy, together with Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and fire events map, were conducted to characterize DOM and investigate its sources and contributions. The results showed that as compared with aquatic and soil DOM, rainwater DOM showed similar spectral characteristics, suggesting DOM in precipitation was also an important contributor to DOM pool in terrestrial and aquatic systems. The concentrations of DOC in rainwater were 0.88-12.80 mg x L(-1), and the CDOM concentrations were 3.17-21.11 mg x L(-1). Differences of DOM samples between summer and winter were significant (P summer, DOM samples in winter had lower molecular weight and aromaticity, and also lower humification. Input of DOM in winter was predominantly derived from local and short-distance distances, while non-special scattering sources were identified as the main contributors in summer. Although absorption and fluorescence spectroscopy could be used to identify DOM composition and sources, there were obvious differences in spectra and sources analysis between rainwater DOM and the others from other sources. Thus, the classic differentiation method by "allochthonous (terrigenous) and autochthonous (authigenic)" is possibly too simple and arbitrary for characterization of DOM in rainwater.

Summer/winter variability of the surfactants in aerosols from Grenoble, France

Science.gov (United States)

Baduel, Christine; Nozière, Barbara; Jaffrezo, Jean-Luc

2012-02-01

Many atmospheric aerosols seem to contain strong organic surfactants likely to enhance their cloud-forming properties. Yet, few techniques allow for the identification and characterization of these compounds. Recently, we introduced a double extraction method to isolate the surfactant fraction of atmospheric aerosol samples, and evidenced their very low surface tension (≤30 mN m -1). In this work, this analytical procedure was further optimized. In addition to an optimized extraction and a reduction of the analytical time, the improved method led to a high reproducibility in the surface tension curves obtained (shapes and minimal values), illustrated by the low uncertainties on the values, ±10% or less. The improved method was applied to PM 10 aerosols from the urban area of Grenoble, France collected from June 2009 to January 2010. Significant variability was observed between the samples. The minimum surface tension obtained from the summer samples was systematically lower (30 mN m -1) than that of the winter samples (35-45 mN m -1). Sharp transitions in the curves together with the very low surface tensions suggested that the dominating surfactants in the summer samples were biosurfactants, which would be consistent with the high biogenic activity in that season. One group of samples from the winter also displayed sharp transitions, which, together with the slightly higher surface tension, suggested the presence of weaker, possibly man-made, surfactants. A second group of curves from the winter did not display any clear transition but were similar to those of macromolecular surfactants such as polysaccharides or humic substances from wood burning. These surfactants are thus likely to originate from wood burning, the dominating source for aerosols in Grenoble in winter. These observations thus confirm the presence of surfactants from combustion processes in urban aerosols reported by other groups and illustrates the ability of our method to distinguish between

Spring Changeover of the Middle Atmosphere Circulation Compared with Rocket Wind Data up to 80 Km

Science.gov (United States)

Entzian, G.; Tarasenko, D. A.; Lauter, E. A.

1984-01-01

The middle atmosphere circulation is governed by two seasonal basic states in winter and summer, twice a year separated by relatively shortlived reversal periods. These seasonal basic states of circulation and the spring changeover period between them are investigated.

Comparison of Summer and Winter Objectively Measured Physical Activity and Sedentary Behavior in Older Adults: Age, Gene/Environment Susceptibility Reykjavik Study.

Science.gov (United States)

Arnardottir, Nanna Yr; Oskarsdottir, Nina Dora; Brychta, Robert J; Koster, Annemarie; van Domelen, Dane R; Caserotti, Paolo; Eiriksdottir, Gudny; Sverrisdottir, Johanna E; Johannsson, Erlingur; Launer, Lenore J; Gudnason, Vilmundur; Harris, Tamara B; Chen, Kong Y; Sveinsson, Thorarinn

2017-10-21

In Iceland, there is a large variation in daylight between summer and winter. The aim of the study was to identify how this large variation influences physical activity (PA) and sedentary behavior (SB). Free living PA was measured by a waist-worn accelerometer for one week during waking hours in 138 community-dwelling older adults (61.1% women, 80.3 ± 4.9 years) during summer and winter months. In general, SB occupied about 75% of the registered wear-time and was highly correlated with age (β = 0.36). Although the differences were small, more time was spent during the summer in all PA categories, except for the moderate-to-vigorous PA (MVPA), and SB was reduced. More lifestyle PA (LSPA) was accumulated in ≥5-min bouts during summer than winter, especially among highly active participants. This information could be important for policy makers and health professionals working with older adults. Accounting for seasonal difference is necessary in analyzing SB and PA data.

Comparison of Summer and Winter Objectively Measured Physical Activity and Sedentary Behavior in Older Adults: Age, Gene/Environment Susceptibility Reykjavik Study

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Nanna Yr Arnardottir

2017-10-01

Full Text Available In Iceland, there is a large variation in daylight between summer and winter. The aim of the study was to identify how this large variation influences physical activity (PA and sedentary behavior (SB. Free living PA was measured by a waist-worn accelerometer for one week during waking hours in 138 community-dwelling older adults (61.1% women, 80.3 ± 4.9 years during summer and winter months. In general, SB occupied about 75% of the registered wear-time and was highly correlated with age (β = 0.36. Although the differences were small, more time was spent during the summer in all PA categories, except for the moderate-to-vigorous PA (MVPA, and SB was reduced. More lifestyle PA (LSPA was accumulated in ≥5-min bouts during summer than winter, especially among highly active participants. This information could be important for policy makers and health professionals working with older adults. Accounting for seasonal difference is necessary in analyzing SB and PA data.

The impact of the winter North Atlantic Oscillation on the frequency of spring dust storms over Tarim Basin in northwest China in the past half-century

International Nuclear Information System (INIS)

Zhao Yong; Huang Anning; Zhou Yang; Huang Ying; Zhu Xinsheng

2013-01-01

The relationship between the frequency of spring dust storms over Tarim Basin in northwest China and the winter North Atlantic Oscillation (NAO) is investigated by using the observed dust storm frequency (DSF) and the 10 m wind velocity at 36 stations in Tarim Basin and the National Centers for Environment Prediction/National Center for Atmospheric Research reanalysis data for the period 1961–2007. The spring DSF (winter NAO) index shows a clear decreasing (increasing) linear trend over 1961–2007. The winter NAO correlates well with the subsequent spring DSF over Tarim Basin on both interannual and interdecadal time scales and its interannual to interdecadal variation plays an important role in the spring DSF. Two possible physical mechanisms are identified. One is related to the large scale anomalous circulations in spring in the middle to high troposphere modulated by the winter NAO, providing the background of dynamical conditions for the dust storm occurrences. The other is related to the shifts in the local horizontal sea level pressure (SLP) gradients and 10 m wind speed, corresponding to changes in the large scale circulations in spring. The decrease in the local 10 m wind speed due to the reduced horizontal SLP gradients over Tarim Basin during the strong winter NAO years contributes to the decline of the DSF in the subsequent spring. (letter)

Physical and biological characteristics of the winter-summer transition in the Central Red Sea

KAUST Repository

Zarokanellos, Nikolaos; Papadopoulos, Vassilis P.; Sofianos, Sarantis. S.; Jones, Burton

2017-01-01

of the CRS. Ship-based and glider observations in the CRS between March and June 2013 capture key features of the transition from winter to summer and depict the impact of the eddy activity on the EBC flow. Less saline and relatively warmer water of Indian

Chemical composition and antifungal activity of the essential oils of Schinus weinmannifolius collected in the spring and winter.

Science.gov (United States)

Hernandes, Camila; Taleb-Contini, Silvia H; Bartolomeu, Ana Carolina D; Bertoni, Bianca W; França, Suzelei C; Pereira, Ana Maria S

2014-09-01

Reports on the chemical and pharmacological profile of the essential oil of Schinus weinmannifolius do not exist, although other Schinus species have been widely investigated for their biological activities. This work aimed to evaluate the chemical composition and antimicrobial activity of the essential oil of S. weinmannifolius collected in the spring and winter. The essential oils were extracted by hydrodistillation, analyzed by GC/MS and submitted to microdilution tests, to determine the minimum inhibitory concentration. The oils displayed different chemical composition and antimicrobial action. Bicyclogermacrene and limonene predominated in the oils extracted in the winter and spring, respectively, whereas only the latter oil exhibited antifungal activity.

Geochemistry of PM10 over Europe during the EMEP intensive measurement periods in summer 2012 and winter 2013

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A. Alastuey

2016-05-01

Full Text Available The third intensive measurement period (IMP organised by the European Monitoring and Evaluation Programme (EMEP under the UNECE CLTRAP took place in summer 2012 and winter 2013, with PM10 filter samples concurrently collected at 20 (16 EMEP regional background sites across Europe for subsequent analysis of their mineral dust content. All samples were analysed by the same or a comparable methodology. Higher PM10 mineral dust loadings were observed at most sites in summer (0.5–10 µg m−3 compared to winter (0.2–2 µg m−3, with the most elevated concentrations in the southern- and easternmost countries, accounting for 20–40 % of PM10. Saharan dust outbreaks were responsible for the high summer dust loadings at western and central European sites, whereas regional or local sources explained the elevated concentrations observed at eastern sites. The eastern Mediterranean sites experienced elevated levels due to African dust outbreaks during both summer and winter. The mineral dust composition varied more in winter than in summer, with a higher relative contribution of anthropogenic dust during the former period. A relatively high contribution of K from non-mineral and non-sea-salt sources, such as biomass burning, was evident in winter at some of the central and eastern European sites. The spatial distribution of some components and metals reveals the influence of specific anthropogenic sources on a regional scale: shipping emissions (V, Ni, and SO42− in the Mediterranean region, metallurgy (Cr, Ni, and Mn in central and eastern Europe, high temperature processes (As, Pb, and SO42− in eastern countries, and traffic (Cu at sites affected by emissions from nearby cities.

Experimental study and performance analysis of a thermoelectric cooling and heating system driven by a photovoltaic/thermal system in summer and winter operation modes

International Nuclear Information System (INIS)

He, Wei; Zhou, JinZhi; Chen, Chi; Ji, Jie

2014-01-01

Highlights: • Thermoelectric heating system driven by heat pipe PV/T system was built and test. • Theoretical analysis has been done and simulation results have been validated by experiments. • The energetic efficiency and exergetic efficiency in summer and winter operation mode was analyzed and compared. - Abstract: This paper presents theoretical and experimental investigations of the winter operation mode of a thermoelectric cooling and heating system driven by a heat pipe photovoltaic/thermal (PV/T) panel. And the energy and exergy analysis of this system in summer and winter operation modes are also done. The winter operation mode of this system is tested in an experimental room which temperature is controlled at 18 °C. The results indicate the average coefficient of performance (COP) of thermoelectric module of this system can be about 1.7, the electrical efficiency of the PV/T panel can reach 16.7%, and the thermal efficiency of this system can reach 23.5%. The energy and exergy analysis show the energetic efficiency of the system in summer operation mode is higher than that of it in winter operation mode, but the exergetic efficiency in summer operation mode is lower than that in winter operation mode, on the contrary

Stormwater quality of spring-summer-fall effluent from three partial-infiltration permeable pavement systems and conventional asphalt pavement.

Science.gov (United States)

Drake, Jennifer; Bradford, Andrea; Van Seters, Tim

2014-06-15

This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave(®) and Eco-Optiloc(®)) and a Hydromedia(®) Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4(+)+NH3), nitrite (NO2(-)) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3(-)). The PP systems had mixed performances for the treatment of phosphate (PO4(3-)). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Planting Date on Cold Tolerance of Winter and Spring Barley Genotypes

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A. R. Eivazi

2015-01-01

Full Text Available In order to evaluate cold tolerance of twenty barley genotypes under field conditions, an experiment was carried out in a randomized complete block design at 3 sowing dates of October 5, November 5, and December 5 in Saatlu Agricultural Research Station, West Azarbaijan, Iran, during 2010-11 seasons. Also, another experiment was conducted on the same genotypes based on a completely randomized design under greenhouse conditions. in wich Cold stress was applied up to -25°C at two, four and six leaf development stages. LT50, ion leakage and dry matter were measured and apex photographed. Field experiment results showed the lowest significant differences at p≤0.05 between different levels of sowing date, genotype, and interaction between them for plant height, spike/m2, kernel per spike, 1000-kernel weight, grain yield and total dry matter. Genotypes of winter growth type had higher grain yield (4250kg/ha than those with spring growth type (4190kg/ha. There were significant differences for ion leakage and dry matter at 4 and 6 leaf development stages under greenhouse conditions. Genotype 1 (winter growth type with lowest values of range and standard deviation for grain yield, total dry matter and LT50 = -38 °C showed a relatively low ion leakage. In contrast, genotypes 5, 10 and 14 (spring growth type were identified sensitive to cold stress due to having more values of range, standard deviation for grain yield and total dry matter, LT50 = -18 to -27 °C and ion leakage from 25 to 33µS/m. Regression analysis showed 1000-kernel weight and total dry matter to remain at final model. Cluster analysis indicated that genotypes 2, 18, 1, 17 and 19 were superior genotypes. In principal component analysis, four components showed 80% of total variations, and the first component with 26% of variation was an important yield component for improving grain yield of barley genotypes. In conclusion, grain yields of winter and spring barley genotypes were

Why Do Some Evergreen Species Keep Their Leaves for a Second Winter, While Others Lose Them?

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Peter J. Grubb

2014-10-01

Full Text Available In subtropical montane semi-moist forest in SW China (SMSF, a large majority of evergreen tree and tall shrub species was found to have only one cohort of old leaves in early spring. In contrast, almost all species of evergreen tree and tall shrub in warm temperate rain forest (WTRF in Japan and sclerophylls in Mediterranean-climate forest (MSF of the Mediterranean Basin have two or more cohorts of old leaves in early spring; they drop their oldest cohort during or soon after leaf outgrowth in spring. Japanese WTRF has no dry season and MSF a dry summer. SMSF has a dry winter. On four evergreen Rhododendron species from SW China with only one cohort of old leaves in spring when in cultivation in Scotland, the majority of leaves in the senescing cohort fell by the end of December. We hypothesize that with dry winters, there is an advantage to dropping older leaves in autumn, because there is a low chance of appreciable positive assimilation in winter and a high chance of desiccation, reducing the resorption of dry mass and mineral nutrients from ageing leaves. Our hypothesis may be extended to cover evergreens at high altitude or high latitude that experience cold soils in winter.

Molecular characterization of three Hsp90 from Pieris and expression patterns in response to cold and thermal stress in summer and winter diapause of Pieris melete.

Science.gov (United States)

Wu, Yue-Kun; Zou, Chao; Fu, Dao-Meng; Zhang, Wan-Na; Xiao, Hai-Jun

2018-04-01

Heat shock proteins (Hsps) have been linked to stresses and winter diapause in insects, but whether they are components of summer diapause is still unknown. In this study, complementary DNAs of Hsp90 from Pieris melete, Pieris rapae and Pieris canidia named PmHsp90, PrHsp90 and PcHsp90, respectively, were cloned and sequenced. The deduced amino acid sequence consisted of 718 amino acid residues with a putative molecular mass of 82.6, 82.6 and 82.7 kDa, respectively. The amino acid sequences contained all of the five conserved signature motifs in the Hsp90 family and a bHLH protein folding activity region. The differential expression pattern of PmHsp90 in response to summer diapause and winter diapause, which are related to heat/cold stress, was investigated. Cold stress induced Hsp90 up-regulation in summer and winter diapause pupae, but not in non-diapause individuals. Heat shock up-regulated PmHsp90 gradually with an increase in temperature in summer diapause, and PmHsp90 was rapidly up-regulated in winter diapause. After 30 min heat shock at 39°C, substantial up-regulation of PmHsp90 transcript levels were observed both in summer and winter diapause. However, in non-diapause a relatively stable expression was found under different durations of 39°C heat shock. Compared to the optimal treatment of 18°C for diapause development, a high temperature acclimation of 31°C induced PmHsp90 up-regulation in summer diapause, whereas a low temperature acclimation of 4°C induced up-regulation in winter diapause. The current results indicate that Hsp90 may play an important role in response to heat/cold stress both in summer and winter diapause. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Oral temperatures of the elderly in nursing homes in summer and winter in relation to activities of daily living

Science.gov (United States)

Nakamura, K.; Tanaka, Masatoshi; Motohashi, Yutaka; Maeda, Akira

This study was conducted to clarify the seasonal difference in body temperature in summer and winter, and to document the thermal environment of the elderly living in nursing homes. The subjects were 57 healthy elderly people aged >=63 years living in two nursing homes in Japan. One of the homes was characterized by subjects with low levels of activities of daily living (ADL). Oral temperatures were measured in the morning and afternoon, with simultaneous recording of ambient temperature and relative humidity. Oral temperatures in summer were higher than in winter, with statistically significant differences (Pchanges in ambient temperature.

Importance of mixotrophic nanoplankton in Aysén Fjord (Southern Chile) during austral winter

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Czypionka, Till; Vargas, Cristian A.; Silva, Nelson; Daneri, Giovanni; González, Humberto E.; Iriarte, José Luis

2011-03-01

Mixotrophy, the combination of autotrophic and heterotrophic nutrition in the same organism, is widespread in planktonic algae. Several reports from temperate and high-latitude fjords in Scandinavia suggest the occurrence of a niche in late summer and autumn during post-bloom conditions in which mixotrophic algae can become important grazers in pelagic ecosystems, accessing the nutrients bound in their prey to overcome nutrient limitation. Here, we experimentally determined the trophic modes and bacterivory rates for the nanoplankton community (2-20 μm) in Aysén Fjord located in the Chilean Northern Patagonia during two contrasting seasons: winter and spring. While mixotrophic nanoplankton was virtually absent from the system in spring, in winter at occasions it even constituted the dominant trophic group of the nanoplankton with abundances of >900 cells mL -1. This indicates a second niche for mixotrophs in winter, when mixotrophy allows overcoming light limitation.

Leaf anatomical and photosynthetic acclimation to cool temperature and high light in two winter versus two summer annuals.

Science.gov (United States)

Cohu, Christopher M; Muller, Onno; Adams, William W; Demmig-Adams, Barbara

2014-09-01

Acclimation of foliar features to cool temperature and high light was characterized in winter (Spinacia oleracea L. cv. Giant Nobel; Arabidopsis thaliana (L.) Heynhold Col-0 and ecotypes from Sweden and Italy) versus summer (Helianthus annuus L. cv. Soraya; Cucurbita pepo L. cv. Italian Zucchini Romanesco) annuals. Significant relationships existed among leaf dry mass per area, photosynthesis, leaf thickness and palisade mesophyll thickness. While the acclimatory response of the summer annuals to cool temperature and/or high light levels was limited, the winter annuals increased the number of palisade cell layers, ranging from two layers under moderate light and warm temperature to between four and five layers under cool temperature and high light. A significant relationship was also found between palisade tissue thickness and either cross-sectional area or number of phloem cells (each normalized by vein density) in minor veins among all four species and growth regimes. The two winter annuals, but not the summer annuals, thus exhibited acclimatory adjustments of minor vein phloem to cool temperature and/or high light, with more numerous and larger phloem cells and a higher maximal photosynthesis rate. The upregulation of photosynthesis in winter annuals in response to low growth temperature may thus depend on not only (1) a greater volume of photosynthesizing palisade tissue but also (2) leaf veins containing additional phloem cells and presumably capable of exporting a greater volume of sugars from the leaves to the rest of the plant. © 2014 Scandinavian Plant Physiology Society.

Winter and spring diving behavior of bowhead whales relative to prey

KAUST Repository

Heide-Jørgensen, Mads

2013-10-23

Background Little is known about bowhead whale (Balaena mysticetus) foraging behavior and what concentrations of prey are required to balance the energetic trade-offs of feeding. We used satellite telemetry, archival depth recorders, and water column echo sounding data to study bowhead whale diving behavior relative to prey depth and concentration in Disko Bay, West Greenland. Results Between March and May 2008 to 2011, nine bowhead whales were tagged in Disko Bay, West Greenland with instruments that collected data on location and diving over a period of 1 to 33 days. The frequency of U-dives (presumed to be foraging dives) was low during winter months but more than doubled in spring concurrent with a decrease in diving depth. The mean speed of the horizontal bottom phase of the U-dives was 0.9 ms-1 and on average, whales spent 37% of their time at the bottom phase of the dive. In March, bowhead whales presumably fed on copepods (Calanus spp.) close to the seabed (between 100 and 400 m). In April and May, after the copepods ascended to shallower depths, bowhead whales also dove to shallower depths (approximately 30 m) more often. However, echo sounding surveys in the vicinity of feeding whales in early May indicated that patches of copepods could still be found close to the seabed. Conclusions There was a marked change in diving behavior from winter through spring and this was likely in response to the changes in sea ice conditions, primary production and potential copepod abundance in the upper part of the water column. Depth and duration of dives changed significantly during this period; however, other dive parameters (for example the proportion of time spent feeding on the bottom of U-dives) remained fairly constant indicating a constant feeding effort. Bowhead whales target copepods at or close to the seabed in winter months in Disko Bay and continue feeding on copepods when they migrate to the surface. However, bowhead whales leave West Greenland before peak

Welfare of Pigs Being Transported over Long Distances Using a Pot-Belly Trailer during Winter and Summer

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Jorge A. Correa

2014-04-01

Full Text Available A total of 2,145 pigs were transported for 8 h in summer (six trips and winter (five trips using a pot-belly trailer accommodating pigs in four locations (upper deck or UD, bottom-nose or BN, middle deck or MD and bottom deck or BD. Heart rate of pigs during loading and transportation and lactate and creatine kinase (CK concentrations in exsanguination blood were measured. Meat quality was evaluated in the Longissimus thoracis (LT, Semimembranosus (SM and Adductor (AD muscles. During summer, pigs loaded in the UD and MD had higher (P < 0.05 heart rate at loading compared to those located in the BD and BN. Blood lactate and CK concentrations were higher (P < 0.001 in winter than in summer. Lactate concentration was higher (P = 0.01 in the blood of pigs transported in the BN. Pigs transported in the BN had higher pHu values in the LT, SM and AD muscles (P = 0.02, P < 0.001 and P = 0.002, respectively and lower (P = 0.002 drip loss values in the SM muscle. This study confirms that some locations within the PB trailer have a negative impact on the welfare of pigs at loading and during transport with more pronounced effects in the winter due to the additive effect of cold stress.

Sex-specific responses to winter flooding, spring waterlogging and post-flooding recovery in Populus deltoides.

Science.gov (United States)

Miao, Ling-Feng; Yang, Fan; Han, Chun-Yu; Pu, Yu-Jin; Ding, Yang; Zhang, Li-Jia

2017-05-31

Winter flooding events are common in some rivers and streams due to dam constructions, and flooding and waterlogging inhibit the growth of trees in riparian zones. This study investigated sex-specific morphological, physiological and ultrastructural responses to various durations of winter flooding and spring waterlogging stresses, and post-flooding recovery characteristics in Populus deltoides. There were no significant differences in the morphological, ultrastructural and the majority of physiological traits in trees subjected to medium and severe winter flooding stresses, suggesting that males and females of P. deltoides were winter flooding tolerant, and insensitive to winter flooding duration. Males were more tolerant to winter flooding stress in terms of photosynthesis and chlorophyll fluorescence than females. Females displayed greater oxidative damage due to flooding stress than males. Males developed more efficient antioxidant enzymatic systems to control reactive oxygen species. Both sexes had similarly strong post-flooding recovery capabilities in terms of plant growth, and physiological and ultrastructural parameters. However, Males had better recovery capabilities in terms of pigment content. These results increase the understanding of poplars's adaptation to winter flooding stress. They also elucidate sex-specific differences in response to flooding stress during the dormant season, and during post-flooding recovery periods.

Do sufficient vitamin D levels at the end of summer in children and adolescents provide an assurance of vitamin D sufficiency at the end of winter? A cohort study.

Science.gov (United States)

Shakeri, Habibesadat; Pournaghi, Seyed-Javad; Hashemi, Javad; Mohammad-Zadeh, Mohammad; Akaberi, Arash

2017-10-26

The changes in serum 25-hydroxyvitamin D (25(OH)D) in adolescents from summer to winter and optimal serum vitamin D levels in the summer to ensure adequate vitamin D levels at the end of winter are currently unknown. This study was conducted to address this knowledge gap. The study was conducted as a cohort study. Sixty-eight participants aged 7-18 years and who had sufficient vitamin D levels at the end of the summer in 2011 were selected using stratified random sampling. Subsequently, the participants' vitamin D levels were measured at the end of the winter in 2012. A receiver operating characteristic (ROC) curve was used to determine optimal cutoff points for vitamin D at the end of the summer to predict sufficient vitamin D levels at the end of the winter. The results indicated that 89.7% of all the participants had a decrease in vitamin D levels from summer to winter: 14.7% of them were vitamin D-deficient, 36.8% had insufficient vitamin D concentrations and only 48.5% where able to maintain sufficient vitamin D. The optimal cutoff point to provide assurance of sufficient serum vitamin D at the end of the winter was 40 ng/mL at the end of the summer. Sex, age and vitamin D levels at the end of the summer were significant predictors of non-sufficient vitamin D at the end of the winter. In this age group, a dramatic reduction in vitamin D was observed over the follow-up period. Sufficient vitamin D at the end of the summer did not guarantee vitamin D sufficiency at the end of the winter. We found 40 ng/mL as an optimal cutoff point.

Genomic regions associated with bovine milk fatty acids in both summer and winter milk samples

NARCIS (Netherlands)

Bouwman, A.C.; Visker, M.H.P.W.; Arendonk, van J.A.M.; Bovenhuis, H.

2012-01-01

Background - In this study we perform a genome-wide association study (GWAS) for bovine milk fatty acids from summer milk samples. This study replicates a previous study where we performed a GWAS for bovine milk fatty acids based on winter milk samples from the same population. Fatty acids from

Winter active bumblebees (Bombus terrestris achieve high foraging rates in urban Britain.

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Ralph J Stelzer

2010-03-01

Full Text Available Foraging bumblebees are normally associated with spring and summer in northern Europe. However, there have been sightings of the bumblebee Bombus terrestris during the warmer winters in recent years in southern England. But what floral resources are they relying upon during winter and how much winter forage can they collect?To test if urban areas in the UK provide a rich foraging niche for bees we set up colonies of B. terrestris in the field during two late winter periods (2005/6 & 2006/7 in London, UK, and measured their foraging performance. Fully automatic radio-frequency identification (RFID technology was used in 2006/7 to enable us to record the complete foraging activity of individually tagged bees. The number of bumblebees present during winter (October 2007 to March 2008 and the main plants they visited were also recorded during transect walks. Queens and workers were observed throughout the winter, suggesting a second generation of bee colonies active during the winter months. Mass flowering shrubs such as Mahonia spp. were identified as important food resources. The foraging experiments showed that bees active during the winter can attain nectar and pollen foraging rates that match, and even surpass, those recorded during summer.B. terrestris in the UK are now able to utilise a rich winter foraging resource in urban parks and gardens that might at present still be under-exploited, opening up the possibility of further changes in pollinator phenology.

Winter active bumblebees (Bombus terrestris) achieve high foraging rates in urban Britain.

Science.gov (United States)

Stelzer, Ralph J; Chittka, Lars; Carlton, Marc; Ings, Thomas C

2010-03-05

Foraging bumblebees are normally associated with spring and summer in northern Europe. However, there have been sightings of the bumblebee Bombus terrestris during the warmer winters in recent years in southern England. But what floral resources are they relying upon during winter and how much winter forage can they collect? To test if urban areas in the UK provide a rich foraging niche for bees we set up colonies of B. terrestris in the field during two late winter periods (2005/6 & 2006/7) in London, UK, and measured their foraging performance. Fully automatic radio-frequency identification (RFID) technology was used in 2006/7 to enable us to record the complete foraging activity of individually tagged bees. The number of bumblebees present during winter (October 2007 to March 2008) and the main plants they visited were also recorded during transect walks. Queens and workers were observed throughout the winter, suggesting a second generation of bee colonies active during the winter months. Mass flowering shrubs such as Mahonia spp. were identified as important food resources. The foraging experiments showed that bees active during the winter can attain nectar and pollen foraging rates that match, and even surpass, those recorded during summer. B. terrestris in the UK are now able to utilise a rich winter foraging resource in urban parks and gardens that might at present still be under-exploited, opening up the possibility of further changes in pollinator phenology.

Winter to summer change in vitamin D status reduces systemic inflammation and bioenergetic activity of human peripheral blood mononuclear cells.

Science.gov (United States)

Calton, Emily K; Keane, Kevin N; Raizel, Raquel; Rowlands, Jordan; Soares, Mario J; Newsholme, Philip

2017-08-01

Vitamin D status [25(OH)D] has recently been reported to be associated with altered cellular bioenergetic profiles of peripheral blood mononuclear cells (PBMCs). No study has tracked the seasonal variation of 25(OH)D and its putative influence on whole body energy metabolism, cellular bioenergetic profiles, inflammatory markers and clinical chemistry. Whole body energy metabolism and substrate utilisation were measured by indirect calorimetry. PBMCs obtained from the same subjects were isolated from whole blood, counted and freshly seeded. Bioenergetic analysis (mitochondrial stress test and glycolysis stress test) was performed using the Seahorse XF e 96 flux analyser. 25(OH)D was assessed using the Architect immunoassay method. 25(OH)D increased by a median (IQR) of 14.40 (20.13)nmol/L (pwinter to summer and was accompanied by significant improvements in indices of insulin sensitivity, McAuley's index (p=0.019) and quantitative insulin sensitivity check index (p=0.028). PBMC mitochondrial parameters basal respiration, non-mitochondrial respiration, ATP production, proton leak, and maximal respiration decreased in summer compared to winter. Similarly, PBMC glycolytic parameters glycolytic activity, glucose response, and glycolytic capacity were all reduced in summer compared to winter. There was also a trend for absolute resting metabolic rate (RMR) to decrease (p=0.066). Markers of systemic inflammation MCP-1, IL-6, IL-8, IL-10, and IL-12p70 decreased significantly in summer compared to winter. Participants who entered winter with a low 25(OH)D (winter 25(OH)D concentrations of 50-75nmol/L or >75nmol/L. The absolute change in 25(OH)D was not associated with altered bioenergetics. Seasonal improvements in 25(OH)D was associated with reduced systemic inflammation, PBMC bioenergetic profiles and whole body energy metabolism. These observational changes in PBMC bioenergetics were most pronounced in those who had insufficient 25(OH)D in winter. The data warrants

Spring and early summer phenology and detection of Ceratitis capitata (Diptera: Tephritidae) in northern Greece

International Nuclear Information System (INIS)

Papadopoulos, N.T.; Katsoyannos, B.I.; Carey, J.R.

2000-01-01

The Mediterranean fruit fly (Medfly), Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is one of the most serious fruit pests world-wide, infesting more than 300 plant species (Liquido et al. 1991). Many studies on population dynamics of C. capitata have been conducted in the tropics (Vargas et al. 1983, Nishida et al. 1985, Eskafi and Kolbe 1990, Harris et al. 1993) and in the Mediterranean area (Rivnay 1951, Benfatto et al. 1989, Campos et al. 1989, Fimiani 1989, Cayol and Causse 1992, Michelakis 1992, Israely et al. 1997, Katsoyannos et al. 1998a). However, there are no detailed studies on the seasonal occurrence and population dynamics of the fly in the most temperate parts of its distribution. The population build up of the fly is mostly determined by host fruit abundance and availability, and by environmental conditions such as temperature and humidity. In northern Greece, which is within the northern limits of the fly's distribution, winter temperatures are unfavourable for C. capitata survival (Papadopoulos et al. 1996). In addition, there is a gap in host fruit availability from near December until the following May. However, C. capitata has developed a remarkable ability to survive in such climates (though suffering high mortality), predominantly as larvae within certain host fruits that become infested at the end of autumn and remain in the orchards until the following spring (Papadopoulos et al. 1996). The prolonged larval period, especially that of the 1st and the 2nd instars, due to low temperatures, enables the fly to survive long periods of unfavourable conditions (Papadopoulos et al. 1998). The few adults emerging in spring, may live as long as 3 months and can oviposit a high number of eggs in artificial oviposition substrates (Papadopoulos et al. 1996). The importance of some key factors - late spring and early summer maturing host fruits - for the re-establishment of the C. capitata population has been suggested (Cayol 1996, Israely et al

Ecological effects of Spring and late Summer applications of Lambda-Cyhalothrin on freshwater microcosms

NARCIS (Netherlands)

Wijngaarden, van R.P.A.; Brock, T.C.M.; Brink, van den P.J.; Gylstra, R.; Maund, S.J.

2006-01-01

The aim of the study was to compare the effects of the pyrethroid insecticide lambda-cyhalothrin (treated at 10, 25, 50, 100, 250 ng active ingredient a.i./L) on a drainage ditch ecosystem in spring and late summer. Microcosms (water volume approximately 430 L) were established using enclosures in a

Impact of grazing dairy steers on winter rye (Secale cereale versus winter wheat (Triticum aestivum and effects on meat quality, fatty acid and amino acid profiles, and consumer acceptability of organic beef.

Directory of Open Access Journals (Sweden)

Hannah N Phillips

Full Text Available Meat from Holstein and crossbred organic dairy steers finished on winter rye and winter wheat pastures was evaluated and compared for meat quality, fatty acid and amino acid profiles, and consumer acceptability. Two adjacent 4-ha plots were established with winter rye or winter wheat cover crops in September 2015 at the University of Minnesota West Central Research and Outreach Center (Morris, MN. During spring of 2015, 30 steers were assigned to one of three replicate breed groups at birth. Breed groups were comprised of: Holstein (HOL; n = 10, crossbreds comprised of Montbéliarde, Viking Red, and HOL (MVH; n = 10, and crossbreds comprised of Normande, Jersey, and Viking Red (NJV; n = 10. Dairy steers were maintained in their respective replicate breed group from three days of age until harvest. After weaning, steers were fed an organic total mixed ration of organic corn silage, alfalfa silage, corn, soybean meal, and minerals until spring 2016. Breed groups were randomly assigned to winter rye or winter wheat and rotationally grazed from spring until early summer of 2016. For statistical analysis, independent variables were fixed effects of breed, forage, and the interaction of breed and forage, with replicated group as a random effect. Specific contrast statements were used to compare HOL versus crossbred steers. Fat from crossbreds had 13% greater omega-3 fatty acids than HOL steers. Furthermore, the omega-6/3 ratio was 14% lower in fat from crossbreds than HOL steers. For consumer acceptability, steaks from steers grazed on winter wheat had greater overall liking than steers grazed on winter rye. Steak from crossbreeds had greater overall liking than HOL steers. The results suggest improvement in fatty acids and sensory attributes of beef from crossbred dairy steers compared to HOL steers, as well as those finished on winter wheat compared to winter rye.

Impact of grazing dairy steers on winter rye (Secale cereale) versus winter wheat (Triticum aestivum) and effects on meat quality, fatty acid and amino acid profiles, and consumer acceptability of organic beef.

Science.gov (United States)

Phillips, Hannah N; Heins, Bradley J; Delate, Kathleen; Turnbull, Robert

2017-01-01

Meat from Holstein and crossbred organic dairy steers finished on winter rye and winter wheat pastures was evaluated and compared for meat quality, fatty acid and amino acid profiles, and consumer acceptability. Two adjacent 4-ha plots were established with winter rye or winter wheat cover crops in September 2015 at the University of Minnesota West Central Research and Outreach Center (Morris, MN). During spring of 2015, 30 steers were assigned to one of three replicate breed groups at birth. Breed groups were comprised of: Holstein (HOL; n = 10), crossbreds comprised of Montbéliarde, Viking Red, and HOL (MVH; n = 10), and crossbreds comprised of Normande, Jersey, and Viking Red (NJV; n = 10). Dairy steers were maintained in their respective replicate breed group from three days of age until harvest. After weaning, steers were fed an organic total mixed ration of organic corn silage, alfalfa silage, corn, soybean meal, and minerals until spring 2016. Breed groups were randomly assigned to winter rye or winter wheat and rotationally grazed from spring until early summer of 2016. For statistical analysis, independent variables were fixed effects of breed, forage, and the interaction of breed and forage, with replicated group as a random effect. Specific contrast statements were used to compare HOL versus crossbred steers. Fat from crossbreds had 13% greater omega-3 fatty acids than HOL steers. Furthermore, the omega-6/3 ratio was 14% lower in fat from crossbreds than HOL steers. For consumer acceptability, steaks from steers grazed on winter wheat had greater overall liking than steers grazed on winter rye. Steak from crossbreeds had greater overall liking than HOL steers. The results suggest improvement in fatty acids and sensory attributes of beef from crossbred dairy steers compared to HOL steers, as well as those finished on winter wheat compared to winter rye.

Changes in aerosol properties during spring-summer period in the Arctic troposphere

Directory of Open Access Journals (Sweden)

A.-C. Engvall

2008-02-01

Full Text Available The change in aerosol properties during the transition from the more polluted spring to the clean summer in the Arctic troposphere was studied. A six-year data set of observations from Ny-Ålesund on Svalbard, covering the months April through June, serve as the basis for the characterisation of this time period. In addition four-day-back trajectories were used to describe air mass histories. The observed transition in aerosol properties from an accumulation-mode dominated distribution to an Aitken-mode dominated distribution is discussed with respect to long-range transport and influences from natural and anthropogenic sources of aerosols and pertinent trace gases. Our study shows that the air-mass transport is an important factor modulating the physical and chemical properties observed. However, the air-mass transport cannot alone explain the annually repeated systematic and rather rapid change in aerosol properties, occurring within a limited time window of approximately 10 days. With a simplified phenomenological model, which delivers the nucleation potential for new-particle formation, we suggest that the rapid shift in aerosol microphysical properties between the Arctic spring and summer is mainly driven by the incoming solar radiation in concert with transport of precursor gases and changes in condensational sink.

Is parental competitive ability in winter negatively affected by previous springs' family size?

Science.gov (United States)

Fokkema, Rienk W; Ubels, Richard; Tinbergen, Joost M

2017-03-01

Reproductive behavior cannot be understood without taking the local level of competition into account. Experimental work in great tits ( Parus major ) showed that (1) a survival cost of reproduction was paid in environments with high levels of competition during the winter period and (2) experimentally manipulated family size negatively affected the ability of parents to compete for preferred breeding boxes in the next spring. The fact that survival was affected in winter suggests that the competitive ability of parents in winter may also be affected by previous reproductive effort. In this study, we aim to investigate whether (1) such carryover effects of family size on the ability of parents to compete for resources in the winter period occurred and (2) this could explain the occurrence of a survival cost of reproduction under increased competition. During two study years, we manipulated the size of in total 168 great tit broods. Next, in winter, we induced competition among the parents by drastically reducing the availability of roosting boxes in their local environment for one week. Contrary to our expectation, we found no negative effect of family size manipulation on the probability of parents to obtain a roosting box. In line with previous work, we did find that a survival cost of reproduction was paid only in plots in which competition for roosting boxes was shortly increased. Our findings thus add to the scarce experimental evidence that survival cost of reproduction are paid under higher levels of local competition but this could not be linked to a reduced competitive ability of parents in winter.

Drier summers cancel out the CO2 uptake enhancement induced by warmer springs.

Science.gov (United States)

Angert, A; Biraud, S; Bonfils, C; Henning, C C; Buermann, W; Pinzon, J; Tucker, C J; Fung, I

2005-08-02

An increase in photosynthetic activity of the northern hemisphere terrestrial vegetation, as derived from satellite observations, has been reported in previous studies. The amplitude of the seasonal cycle of the annually detrended atmospheric CO(2) in the northern hemisphere (an indicator of biospheric activity) also increased during that period. We found, by analyzing the annually detrended CO(2) record by season, that early summer (June) CO(2) concentrations indeed decreased from 1985 to 1991, and they have continued to decrease from 1994 up to 2002. This decrease indicates accelerating springtime net CO(2) uptake. However, the CO(2) minimum concentration in late summer (an indicator of net growing-season uptake) showed no positive trend since 1994, indicating that lower net CO(2) uptake during summer cancelled out the enhanced uptake during spring. Using a recent satellite normalized difference vegetation index data set and climate data, we show that this lower summer uptake is probably the result of hotter and drier summers in both mid and high latitudes, demonstrating that a warming climate does not necessarily lead to higher CO(2) growing-season uptake, even in high-latitude ecosystems that are considered to be temperature limited.

Gross anatomy of the gastrointestinal tract in reindeer, free-living and fed baled timothy silage in summer and winter

Directory of Open Access Journals (Sweden)

Tove H. Aagnes

1996-01-01

Full Text Available The gross anatomy of the gastrointestinal (GI tract was investigated in reindeer calves (Rangtfer tarandus tarandus, free-living and fed two different qualities of timothy silage in September 1992 (summer and April 1993 (winter and related to the body condition. At both seasons nine male reindeer calves were taken from a natural pasture. Three animals were slaughtered directly (NP reindeer, three offered first cut (FC silage and three regrowth (RG silage ad lib., for 46 days. The FC silage contained 27% leaves and 57.8% dry matter (DM cell wall content (CWC and the RG silage 89 % leaves, and 38.7% DM CWC. The reticulo-rumen (RR digesta wet weight in the NP reindeer in summer was 6.7-7.7% of body mass (BM, compared to 25.1-32.8% and 9.6-12.9% of BM, respectively, in the animals fed FC and RG silage. In winter the RR digesta wet weight relative to BM in the NP reindeer and in the animals fed FC and RG silages were 9-5-11.5%, 25.4-33.3% and 10.4-18.3%, respectively. The distal fermentation chamber (DFC digesta wet weight in the NP animals in summer was 0.48-0.80% of BM, compared to 0.77-1.26% and 0.57¬0.65% of BM, respectively, in the animals fed FC and RG silage. In winter the DFC digesta wet weight relative to BM in the animals fed FC and RG silage did not differ significantly from the summer values (P>0.05, while in the NP reindeer it was 1.0-1.2% of BM which is significantly greater than in summer (P<0.05. The differences in relative weight of the fermentation chambers between the animals fed FC and RG silage both summer and winter were not reflected in total BM, which was similar in all groups fed silage. This is explained by a significantly lower carcass weight in the animals fed FC silage compared to the animals fed RG silage. Thus, the GI-tract gross anatomy in the silage fed animals seem to be highly affected by the plant structure and composition, and not by the season.

Nutrient Losses during Winter and Summer Storage of Separated and Unseparated Digested Cattle Slurry.

Science.gov (United States)

Perazzolo, Francesca; Mattachini, Gabriele; Riva, Elisabetta; Provolo, Giorgio

2017-07-01

Management factors affect nutrient loss during animal manure slurry storage in different ways. We conducted a pilot-scale study to evaluate carbon (C) and nitrogen (N) losses from unseparated and digested dairy slurry during winter and summer storage. In addition to season, treatments included mechanical separation of digestate into liquid and solid fractions and bimonthly mixing. Chemical analyses were performed every 2 wk for the mixed materials and at the start and end of storage for unmixed materials. The parameters examined allowed us to estimate C and N losses and examine the factors that determine these losses as well as emission patterns. Gas measurements were done every 2 wk to determine the main forms in which gaseous losses occurred. To evaluate the effect of separation, measured losses and emissions of separated liquid and solid fractions were mathematically combined using the mass separation efficiency of the mechanical separator. Nutrient losses were mainly affected by climatic conditions. Losses of C (up to 23%) from unseparated, unmixed digestate and of N (38% from combined separated fractions and from unseparated digestate) were much greater in summer than in winter, when C and N losses were losses ( losses (up to 64 and 90% of total losses, respectively) in summer. Moreover, management practices should limit NH, the main form of N losses (up to 99.5%). Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Changes in oil composition after chronic irradiation of winter and spring zero-erucic rape hybrids

International Nuclear Information System (INIS)

Fabry, A.; Cerny, J.

1980-01-01

Hybrid plants of the F1 generation of erucic-free spring Canadian rape and some winter rape cultivars containing erucic acid were irradiated in a gamma field with doses ranging between 5973 and 329 R during vegetation. Chronic irradiation increased significantly the frequency of zero- or low-erucic genotypes in the segregating F2 generation. Chronic irradiation disturbed the correlations between the contents of the studied fatty acids in the hybrid F1, F2 and F3 progenies. Lines of zero- and low-erucic winter rapes with a reduced content of linolenic acid and increased content of linoleic acid were obtained by selection. (author)

Triacylglycerol Profile of Summer and Winter Bovine Milk Fat and the Feasibility of Triacylglycerol Fragmentation

NARCIS (Netherlands)

Tzompa-Sosa, Daylan A.; Meurs, Pim P.; Valenberg, van Hein J.F.

2018-01-01

Bovine milk fat (MF) is considered to be one of the most complex fats, as it can consist of 400 FA which are non-randomly esterified into the TAG molecule. This study aims to determine specific differences on MF TAG profile between summer and winter cow's milk, and to study the feasibility of TAG

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.

Winter-summer succession of unicellular eukaryotes in a meso-eutrophic coastal system.

Science.gov (United States)

Christaki, Urania; Kormas, Konstantinos A; Genitsaris, Savvas; Georges, Clément; Sime-Ngando, Télesphore; Viscogliosi, Eric; Monchy, Sébastien

2014-01-01

The objective of this study was to explore the succession of planktonic unicellular eukaryotes by means of 18S rRNA gene tag pyrosequencing in the eastern English Channel (EEC) during the winter to summer transition. The 59 most representative (>0.1%, representing altogether 95% of total reads), unique operational taxonomic units (OTUs) from all samples belonged to 18 known high-level taxonomic groups and 1 unaffiliated clade. The five most abundant OTUs (69.2% of total reads) belonged to Dinophyceae, Cercozoa, Haptophyceae, marine alveolate group I, and Fungi. Cluster and network analysis between samples distinguished the winter, the pre-bloom, the Phaeocystis globosa bloom and the post-bloom early summer conditions. The OTUs-based network revealed that P. globosa showed a relatively low number of connections-most of them negative-with all other OTUs. Fungi were linked to all major taxonomic groups, except Dinophyceae. Cercozoa mostly co-occurred with the Fungi, the Bacillariophyceae and several of the miscellaneous OTUs. This study provided a more detailed exploration into the planktonic succession pattern of the EEC due to its increased depth of taxonomic sampling over previous efforts based on classical monitoring observations. Data analysis implied that the food web concept in a coastal system based on predator-prey (e.g. grazer-phytoplankton) relationships is just a part of the ecological picture; and those organisms exploiting a variety of strategies, such as saprotrophy and parasitism, are persistent and abundant members of the community.

Patterns of North African dust transport over the Atlantic: winter vs. summer, based on CALIPSO first year data

Directory of Open Access Journals (Sweden)

Y. Ben-Ami

2009-10-01

Full Text Available One of the most important factors that determine the transported dust effect on the atmosphere is its vertical distribution. In this study the vertical structure of North African dust and stratiform low clouds is analyzed over the Atlantic Ocean for the 2006–2007 boreal winter (December–February and boreal summer of 2006 (June–August. By using the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO backscatter measurements over the dust routes, we describe the differences in dust transport between the seasons. We show a bi-modal distribution of the average dust plumes height in both seasons (it is less clear in the winter. The higher plume top height is 5.1±0.4 km, near the African coast line in the summer and 3.7±0.4 km in the winter. The lower plume merges with the marine boundary layer, in both seasons. Our study suggests that a significant part of the dust is transported near and within the marine boundary layer and interacts with low stratiform clouds.

Regional-scale winter-spring temperature variability and chilling damage dynamics over the past two centuries in southeastern China

Energy Technology Data Exchange (ETDEWEB)

Duan, Jianping; Zhang, Qi-Bin; Lv, Lixin; Zhang, Chao [Institute of Botany, Chinese Academy of Sciences, State Key Laboratory of Vegetation and Environmental Change, Beijing (China)

2012-08-15

Winter-spring cold extreme is a kind of serious natural disaster for southeastern China. As such events are recorded in discrete documents, long and continuous records are required to understand their characteristics and driving forces. Here we report a regional-scale winter-spring (January-April) temperature reconstruction based on a tree-ring network of pine trees (Pinus massoniana) from five sampling sites over a large spatial scale (25-29 N, 111-115 E) in southeastern China. The regional tree-ring chronology explains 48.6% of the instrumental temperature variance during the period 1957-2008. The reconstruction shows six relatively warm intervals (i.e., {proportional_to}1849-1855, {proportional_to}1871-1888, {proportional_to}1909-1920, {proportional_to}1939-1944, {proportional_to}1958-1968, 1997-2007) and five cold intervals (i.e., {proportional_to}1860-1870, {proportional_to}1893-1908, {proportional_to}1925-1934, {proportional_to}1945-1957, {proportional_to}1982-1996) during 1849-2008. The last decade and the 1930s were the warmest and coldest decades, respectively, in the past 160 years. The composite analysis of 500-hPa geopotential height fields reveals that distinctly different circulation patterns occurred in the instrumental and pre-instrumental periods. The winter-spring cold extremes in southeastern China are associated with Ural-High ridge pattern for the instrumental period (1957-2008), whereas the cold extremes in pre-instrumental period (1871-1956) are associated with North circulation pattern. (orig.)

The Effect of Zinc Fertilizer Application on Grain Yield of Different Zinc-Efficient Spring and Winter Wheat Cultivars

Directory of Open Access Journals (Sweden)

M. Malian

2014-08-01

Full Text Available These field trials were carried out to investigate the effect of various zinc (Zn fertilizer application treatments on grain yield of some spring (Isfahan and Neishabour and winter wheat cultivars (Mashhad and Jolge-e-Rokh with different Zn efficiency during 2009-2010 growth seasons. Five Zn fertilizer treatments were applied including: no added Zn (control, soil application of Zn-sulfate, and foliar spray of Zn-sulfate, Omex1, and Omex2. Omex1 and Omex2 contained 4 and 17% Zn, respectively. Foliar spray was performed at the anthesis stage. Both spring and winter wheat genotypes significantly differed in grain yield. The results showed that wheat genotypes largely varied in their grain yield response to different Zn application treatments. Some spring (Sholeh in Isfahan and winter (Sabalan in Jolg-e-Rokh wheat genotypes had greater response to Zn fertilization so that Zn addition increased grain yield of Sholeh by 48% and Sabalan by 17% as compared with no added Zn control. In contrast, Zn addition had no effect on grain yield of some other genotypes. Yield response of wheat genotypes to Zn application treatments significantly varied upon location. According to the results obtained from this study, the efficacy of Zn fertilizer treatments on grain yield of wheat is dependent on the genotype and location. Therefore, this concern should be considered in fertilizer recommendation programs that a specific Zn fertilizer treatment may not be recommended for all wheat cultivars and locations.

Fiscal 1999 survey on conservation of Jozankei hot spring. Survey report of hot spring alteration; 1999 nendo jozankei onsen hozen chosa. Onsen hendo chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-06-01

As a part of fiscal 1999 survey on conservation of Jozankei hot spring, a survey was made on the change of water composition in hot springs and rivers for the purpose of elucidating the cause of hot spring alteration. In the survey, sampling and water quality analysis were conducted once a month at four sources and one river point on the upstream side of Tsukimibashi bridge on the Toyohira river and at two sources and one river point between Tsukimibashi bridge and Takayamabashi bridge. Also carried out were sampling and constituent analysis at five points for river water of a wide area. The survey results were as follows. The pattern of change in spring water temperature was recognized such that it tended to rise in summer when river temperature was high and to fall in winter. Spring water temperature rose greatly at the time of higher water level like the thaw in some sources but conversely fell in other sources. The fluctuation trend in PH values was such that they mostly went up in April of snow melting time and in early August of much rain and went down in winter of little rain and less snowmelt. As for electric conductivity and dissolved constituents, it was recognized that the conductivity lowered and that the constituents decreased in concentration, all concurrently at the time of snowmelt and much rain. (NEDO)

Chrysophyte cysts from lake sediments reveal the submillennial winter/spring climate variability in the northwestern Mediterranean region throughout the Holocene

Energy Technology Data Exchange (ETDEWEB)

Pla, Sergi [Queen' s University, PEARL, Department of Biology, Kingston, ON (Canada); Catalan, Jordi [CSIC, CSIC-UB Limnology Group, Centre for Advanced Studies of Blanes (CEAB), Blanes (Spain)

2005-02-01

In the last decade, much effort was dedicated to the reconstruction of past climate at high temporal resolution. Here, we show the suitability of chrysophyte cysts from lake sediments for revealing continental climate variability when used in sensitive sites, such as those in high mountains. We demonstrate that altitude is a main factor influencing the present distribution of chrysophytes and develop a transfer function to evaluate the local ''altitude anomaly'' on a lake site throughout time. Based on our knowledge of chrysophyte ecology, the altitude anomalies are interpreted as winter/spring climate signatures. The method was applied to a Holocene record from a lake in the Pyrenees showing submillennial climatic variability in this northwestern Mediterranean zone. A warming trend was present from the early Holocene to 4 kyear BP. Comparison with pollen-based reconstructions of summer temperatures denoted a contrasting decrease in continentality between the two parts of the Holocene. Oscillations of 1 cycle per ca. 2,000 years appeared throughout the record. The warmest Holocene winters were recorded during the Medieval Warm Period at ca. AD900 and 450 and the Roman Warm Period (2.7-2.4 kyear BP). Winters in the period AD1,050-1,175 were inferred to be as cold as in the Little Ice Age. The period between 3 and 7 kyear BPshowed lower intensity in the fluctuations than in early and late Holocene. The cold event, 8,200 years ago, appeared embedded in a warm fluctuation. Another cold fluctuation was recorded around 9 kyear BP, which is in agreement with Irish and Greenland records. (orig.)

Winter flooding of California rice fields reduces immature populations of Lissorhoptrus oryzophilus (Coleoptera: Curculionidae) in the spring.

Science.gov (United States)

Aghaee, Mohammad-Amir; Godfrey, Larry D

2017-07-01

In California, rice fields are flooded over the winter months (November to March) to facilitate degradation of post-harvest rice straw and to provide temporary habitat for migratory waterfowl. Prior research showed that winter flood rice fields had fewer rice water weevil (Lissorhoptrus oryzophilus), larvae and pupae during the rice production season than fields that were left unflooded in the winter. A series of experiments were conducted to provide further support for these trends under controlled conditions and to find a mechanism for this phenomenon. Under winter flooded conditions there was a 50% reduction in populations of weevil immatures compared with the untreated control (no straw or winter flood). These same conditions corresponded to a 20% increase in the amount of silicon found in plant tissues in 2014 and a 39 to 90% decrease in methane production in the soil from 2013 to 2014, respectively. Evidence from previous field research and these controlled studies supports winter flooding as an appropriate tactic for controlling L. oryzophilus populations in the spring. However, the mechanism that would explain why winter flooding adversely affects L. oryzophilus immatures remains unclear. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Biotelemetry study of spring and summer habitat selection by striped bass in Cherokee Reservoir, Tennessee, 1978. [Morone saxatilis

Energy Technology Data Exchange (ETDEWEB)

Schaich, B.A.; Coutant, C.C.

1980-08-01

Habitat selection of 31 adult striped bass was monitored by temperature sensing ultrasonic and radio transmitters in Cherokee Reservoir, Tennessee, from March through October 1978. This study sought to corroborate summer data obtained by Waddle (1979) in 1977 and to examine mechanisms of habitat selection by observing establishment of the summer distribution. During the spring and early summer months the striped bass ranged throughout the study area in the downstream half of the reservoir. Fish stayed near the bottom at the preferred temperatures throughout the whole study, and no individuals were observed in open water. Movement rates of up to 2.6 km/day were estimated, and rates of 1 km/day were common in the spring. By late July they were apparently avoiding low dissolved oxygen (D.O.) concentrations (<3 mg/l) near the bottom of the main reservoir and epilimnion temperatures greater than 22/sup 0/C, and they moved into cool, oxygenated spring or creek channels (refuges). Low movement rates of 0 to 25 m/day within these refuges occurred. The rates of the few migrations between refuges could not be estimated. Tagged fish moved out of the refuges 3 to 4 weeks after the fall overturn when reservoir temperatures approximated 22 to 24/sup 0/C.

Impacts of winter NPO on subsequent winter ENSO: sensitivity to the definition of NPO index

Science.gov (United States)

Chen, Shangfeng; Wu, Renguang

2018-01-01

This study investigates the linkage between boreal winter North Pacific Oscillation (NPO) and subsequent winter El Niño-Southern Oscillation (ENSO) based on seven different NPO indices. Results show that the influence of winter NPO on the subsequent winter El Niño is sensitive to how the NPO is defined. A significant NPO-El Niño connection is obtained when the NPO-related anomalous cyclone over the subtropical North Pacific extends to near-equatorial regions. The anomalous cyclone induces warm sea surface temperature (SST) anomalies through modulating surface heat fluxes. These warm SST anomalies are able to maintain into the following spring and summer through an air-sea coupled process and in turn induce significant westerly wind anomalies over the tropical western Pacific. In contrast, the NPO-El Niño relationship is unclear when the NPO-related anomalous cyclone over the subtropical North Pacific is confined to off-equatorial regions and cannot induce significant warm SST anomalies over the subtropical North Pacific. The present study suggests that definitions of NPO should be taken into account when using NPO to predict ENSO. In particular, we recommend defining the NPO index based on the empirical orthogonal function technique over appropriate region that does not extend too far north.

Satellite passive microwave rain rate measurement over croplands during spring, summer and fall

International Nuclear Information System (INIS)

Spencer, R.W.

1984-01-01

Rain rate algorithms for spring, summer and fall that have been developed from comparisons between the brightness temperatures measured by the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) and rain rates derived from operational WSR-57 radars over land are described. Data were utilized from a total of 25 SMMR passes and 234 radars, resulting in ∼12 000 observations of ∼1600 km 2 areas. Multiple correlation coefficients of 0.63, 0.80 and 0.75 are achieved for the spring, summer and fall algorithms, respectively. Most of this information is in the form of multifrequency contrast in brightness temperature, which is interpreted as a measurement of the degree to which the land-emitted radiation is attenuated by the rain systems. The SMMR 37 GHz channel has more information on rain rate than any other channel. By combining the lower frequency channels with the 37 GHz observations, variations in land and precipitation thermometric temperatures can be removed, leaving rain attenuation as the major effect on brightness temperature. Polarization screening at 37 GHz is found to be sufficient to screen out cases of wet ground, which is only important when the ground is relatively vegetation free. Heavy rain cases are found to be a significant part of the algorithms' success, because of the strong microwave signatures (low brightness temperatures) that result from the presence of precipitation-sized ice in the upper portions of heavily precipitating storms. If IR data are combined with the summer microwave data, an improved (0.85) correlation with radar rain rates is achieved

Physical and biological characteristics of the winter-summer transition in the Central Red Sea

KAUST Repository

Zarokanellos, Nikolaos

2017-07-25

The Central Red Sea (CRS) lies between two distinct hydrographic and atmospheric regimes. In the southern Red Sea, seasonal monsoon reversal regulates the exchange of water between the Red Sea and the Indian Ocean. In the northern Red Sea, intermediate and occasionally deep water are formed during winter to sustain the basin\\'s overturning circulation. Highly variable mesoscale eddies and the northward flowing eastern boundary current (EBC) determine the physical and biogeochemical characteristics of the CRS. Ship-based and glider observations in the CRS between March and June 2013 capture key features of the transition from winter to summer and depict the impact of the eddy activity on the EBC flow. Less saline and relatively warmer water of Indian Ocean origin reaches the CRS via the EBC. Initially, an anticyclonic eddy with diameter of 140 km penetrating to 150m depth with maximum velocities up to 30–35 cm s prevails in the CRS. This anticyclonic eddy appears to block or at least redirect the northward flow of the EBC. Dissipation of the eddy permits the near-coastal, northward flow of the EBC and gives place to a smaller cyclonic eddy with a diameter of about 50 km penetrating to 200 m depth. By the end of May, as the northerly winds become stronger and persistent throughout the basin, characteristic of the summer southwest monsoon wind regime, the EBC, and its associated lower salinity water became less evident, replaced by the saltier surface water that characterizes the onset of the summer stratification in the CRS.

Multiproxy summer and winter surface air temperature field reconstructions for southern South America covering the past centuries

Energy Technology Data Exchange (ETDEWEB)

Neukom, R.; Grosjean, M.; Wanner, H. [University of Bern, Oeschger Centre for Climate Change Research (OCCR), Bern (Switzerland); University of Bern, Institute of Geography, Climatology and Meteorology, Bern (Switzerland); Luterbacher, J. [Justus Liebig University of Giessen, Department of Geography, Climatology, Climate Dynamics and Climate Change, Giessen (Germany); Villalba, R.; Morales, M.; Srur, A. [CONICET, Instituto Argentino de Nivologia, Glaciologia y Ciencias Ambientales (IANIGLA), Mendoza (Argentina); Kuettel, M. [University of Bern, Oeschger Centre for Climate Change Research (OCCR), Bern (Switzerland); University of Bern, Institute of Geography, Climatology and Meteorology, Bern (Switzerland); University of Washington, Department of Earth and Space Sciences, Seattle (United States); Frank, D. [Swiss Federal Research Institute WSL, Birmensdorf (Switzerland); Jones, P.D. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom); Aravena, J.-C. [Centro de Estudios Cuaternarios de Fuego Patagonia y Antartica (CEQUA), Punta Arenas (Chile); Black, D.E. [Stony Brook University, School of Marine and Atmospheric Sciences, Stony Brook (United States); Christie, D.A.; Urrutia, R. [Universidad Austral de Chile Valdivia, Laboratorio de Dendrocronologia, Facultad de Ciencias Forestales y Recursos Naturales, Valdivia (Chile); D' Arrigo, R. [Earth Institute at Columbia University, Tree-Ring Laboratory, Lamont-Doherty Earth Observatory, Palisades, NY (United States); Lara, A. [Universidad Austral de Chile Valdivia, Laboratorio de Dendrocronologia, Facultad de Ciencias Forestales y Recursos Naturales, Valdivia (Chile); Nucleo Cientifico Milenio FORECOS, Fundacion FORECOS, Valdivia (Chile); Soliz-Gamboa, C. [Utrecht Univ., Inst. of Environmental Biology, Utrecht (Netherlands); Gunten, L. von [Univ. of Bern (Switzerland); Univ. of Massachusetts, Climate System Research Center, Amherst (United States)

2011-07-15

We statistically reconstruct austral summer (winter) surface air temperature fields back to ad 900 (1706) using 22 (20) annually resolved predictors from natural and human archives from southern South America (SSA). This represents the first regional-scale climate field reconstruction for parts of the Southern Hemisphere at this high temporal resolution. We apply three different reconstruction techniques: multivariate principal component regression, composite plus scaling, and regularized expectation maximization. There is generally good agreement between the results of the three methods on interannual and decadal timescales. The field reconstructions allow us to describe differences and similarities in the temperature evolution of different sub-regions of SSA. The reconstructed SSA mean summer temperatures between 900 and 1350 are mostly above the 1901-1995 climatology. After 1350, we reconstruct a sharp transition to colder conditions, which last until approximately 1700. The summers in the eighteenth century are relatively warm with a subsequent cold relapse peaking around 1850. In the twentieth century, summer temperatures reach conditions similar to earlier warm periods. The winter temperatures in the eighteenth and nineteenth centuries were mostly below the twentieth century average. The uncertainties of our reconstructions are generally largest in the eastern lowlands of SSA, where the coverage with proxy data is poorest. Verifications with independent summer temperature proxies and instrumental measurements suggest that the interannual and multi-decadal variations of SSA temperatures are well captured by our reconstructions. This new dataset can be used for data/model comparison and data assimilation as well as for detection and attribution studies at sub-continental scales. (orig.)

Plankton community structure and role of Oithona similis on the western coast of Greenland during the winter-spring transition

DEFF Research Database (Denmark)

Zamora-Terol, Sara; Nielsen, Torkel Gissel; Saiz, Enric

2013-01-01

The cyclopoid copepod Oithona similis is one of the most abundant copepods in the oceans, and has a potentially important role in pelagic food webs. However, there is a lack of knowledge on aspects of Oithona's biology and function in plankton communities. In the present study, we aimed to assess...... and compare its trophic role in Greenlandic coastal waters during the winter-spring transition, with a focus on its winter behaviour, when large calanoids are not present in the surface layer. Two locations were studied: waters offshore from Godthåbsfjord (Nuuk) in winter, and Qeqertarsuaq (Disko Bay...

Tissue- and Cell-Specific Cytokinin Activity in Populus × canescens Monitored by ARR5::GUS Reporter Lines in Summer and Winter.

Science.gov (United States)

Paul, Shanty; Wildhagen, Henning; Janz, Dennis; Teichmann, Thomas; Hänsch, Robert; Polle, Andrea

2016-01-01

Cytokinins play an important role in vascular development. But knowledge on the cellular localization of this growth hormone in the stem and other organs of woody plants is lacking. The main focus of this study was to investigate the occurrence and cellular localization of active cytokinins in leaves, roots, and along the stem of Populus × canescens and to find out how the pattern is changed between summer and winter. An ARR5::GUS reporter construct was used to monitor distribution of active cytokinins in different tissues of transgenic poplar lines. Three transgenic lines tested under outdoor conditions showed no influence of ARR5::GUS reporter construct on the growth performance compared with the wild-type, but one line lost the reporter activity. ARR5::GUS activity indicated changes in the tissue- and cell type-specific pattern of cytokinin activity during dormancy compared with the growth phase. ARR5::GUS activity, which was present in the root tips in the growing season, disappeared in winter. In the stem apex ground tissue, ARR5::GUS activity was higher in winter than in summer. Immature leaves from tissue-culture grown plants showed inducible ARR5::GUS activity. Leaf primordia in summer showed ARR5::GUS activity, but not the expanded leaves of outdoor plants or leaf primordia in winter. In stem cross sections, the most prominent ARR5::GUS activity was detected in the cortex region and in the rays of bark in summer and in winter. In the cambial zone the ARR5::GUS activity was more pronounced in the dormant than in growth phase. The pith and the ray cells adjacent to the vessels also displayed ARR5::GUS activity. In silico analyses of the tissue-specific expression patterns of the whole PtRR type-A family of poplar showed that PtRR10, the closest ortholog to the Arabidopsis ARR5 gene, was usually the most highly expressed gene in all tissues. In conclusion, gene expression and tissue-localization indicate high activity of cytokinins not only in summer, but

Summer and winter space use and home range characteristics of Golden Eagles (Aquila chrysaetos) in eastern North America

Science.gov (United States)

Miller, Tricia A.; Brooks, Robert P.; Lanzone, Michael J.; Cooper, Jeff; O'Malley, Kieran; Brandes, David; Duerr, Adam E.; Katzner, Todd

2017-01-01

Movement behavior and its relationship to habitat provide critical information toward understanding the effects of changing environments on birds. The eastern North American population of Golden Eagles (Aquila chrysaetos) is a genetically distinct and small population of conservation concern. To evaluate the potential responses of this population to changing landscapes, we calculated the home range and core area sizes of 52 eagles of 6 age–sex classes during the summer and winter seasons. Variability in range size was related to variation in topography and open cover, and to age and sex. In summer, eagle ranges that were smaller had higher proportions of ridge tops and open cover and had greater topographic roughness than did larger ranges. In winter, smaller ranges had higher proportions of ridge tops, hillsides and cliffs, and open cover than did larger ranges. All age and sex classes responded similarly to topography and open cover in both seasons. Not surprisingly, adult eagles occupied the smallest ranges in both seasons. Young birds used larger ranges than adults, and subadults in summer used the largest ranges (>9,000 km2). Eastern adult home ranges in summer were 2–10 times larger than those reported for other populations in any season. Golden Eagles in eastern North America may need to compensate for generally lower-quality habitat in the region by using larger ranges that support access to adequate quantities of resources (prey, updrafts, and nesting, perching, and roosting sites) associated with open cover and diverse topography. Our results suggest that climate change–induced afforestation on the breeding grounds and ongoing land cover change from timber harvest and energy development on the wintering grounds may affect the amount of suitable habitat for Golden Eagles in eastern North America.

Comparison of the decomposition VOC profile during winter and summer in a moist, mid-latitude (Cfb climate.

Directory of Open Access Journals (Sweden)

Shari L Forbes

Full Text Available The investigation of volatile organic compounds (VOCs associated with decomposition is an emerging field in forensic taphonomy due to their importance in locating human remains using biological detectors such as insects and canines. A consistent decomposition VOC profile has not yet been elucidated due to the intrinsic impact of the environment on the decomposition process in different climatic zones. The study of decomposition VOCs has typically occurred during the warmer months to enable chemical profiling of all decomposition stages. The present study investigated the decomposition VOC profile in air during both warmer and cooler months in a moist, mid-latitude (Cfb climate as decomposition occurs year-round in this environment. Pig carcasses (Sus scrofa domesticus L. were placed on a soil surface to decompose naturally and their VOC profile was monitored during the winter and summer months. Corresponding control sites were also monitored to determine the natural VOC profile of the surrounding soil and vegetation. VOC samples were collected onto sorbent tubes and analyzed using comprehensive two-dimensional gas chromatography--time-of-flight mass spectrometry (GC × GC-TOFMS. The summer months were characterized by higher temperatures and solar radiation, greater rainfall accumulation, and comparable humidity when compared to the winter months. The rate of decomposition was faster and the number and abundance of VOCs was proportionally higher in summer. However, a similar trend was observed in winter and summer demonstrating a rapid increase in VOC abundance during active decay with a second increase in abundance occurring later in the decomposition process. Sulfur-containing compounds, alcohols and ketones represented the most abundant classes of compounds in both seasons, although almost all 10 compound classes identified contributed to discriminating the stages of decomposition throughout both seasons. The advantages of GC × GC-TOFMS were

Investigations into the early life history of naturally produced spring chinook salmon in the Grande Ronde River Basin: annual progress report project period 1 September 1998 to 31 August 1999; ANNUAL

International Nuclear Information System (INIS)

Jonasson, Brian C.

2000-01-01

We determined migration timing and abundance of juvenile spring chinook salmon from three populations in the Grande Ronde River basin. We estimated 13,180 juvenile chinook salmon left upper rearing areas of the Grande Ronde River from July 1998 to June 1999; approximately 0.2% of the migrants left in summer, 18% in fall and 82% in spring. We estimated 15,949 juvenile chinook salmon left upper rearing areas of Catherine Creek from July 1998 to June 1999; approximately 0.2% of the migrants left in summer, 57% in fall, 2% in winter, and 41% in spring. We estimated 14,537 juvenile chinook salmon left the Grande Ronde Valley, located below the upper rearing areas in Catherine Creek and the Grande Ronde River, from October 1998 to June 1999; approximately 99% of the migrants left in spring. We estimated 31,113 juvenile chinook salmon left upper rearing areas of the Lostine River from July 1998 to June 1999; approximately 4% of the migrants left in summer, 57% in fall, 3% in winter, and 36% in spring. We estimated 42,705 juvenile spring chinook salmon left the Wallowa Valley, located below the mouth of the Lostine River, from August 1998 to June 1999; approximately 46% of the migrants left in fall, 6% in winter, and 47% in spring. Juvenile chinook salmon PIT-tagged on the upper Grande Ronde River were detected at Lower Granite Dam from 31 March to 20 June 1999, with a median passage date of 5 May. PIT-tagged salmon from Catherine Creek were detected at Lower Granite Dam from 19 April to 9 July 1999, with a median passage date of 24 May. PIT-tagged salmon from the Lostine River were detected at Lower Granite Dam from 31 March through 8 July 1999, with a median passage date of 4 May. Juveniles tagged as they left the upper rearing areas of the Grande Ronde River in fall and that overwintered in areas downstream were detected in the hydrosystem at a higher rate than fish tagged during winter in the upper rearing areas, indicating a higher overwinter survival in the

A WRF sensitivity study for summer ozone and winter PM events in California

Science.gov (United States)

Zhao, Z.; Chen, J.; Mahmud, A.; Di, P.; Avise, J.; DaMassa, J.; Kaduwela, A. P.

2014-12-01

Elevated summer ozone and winter PM frequently occur in the San Joaquin Valley (SJV) and the South Coast Air Basin (SCAB) in California. Meteorological conditions, such as wind, temperature and planetary boundary layer height (PBLH) play crucial roles in these air pollution events. Therefore, accurate representation of these fields from a meteorological model is necessary to successfully reproduce these air pollution events in subsequent air quality model simulations. California's complex terrain and land-sea interface can make it challenging for meteorological models to replicate the atmospheric conditions over the SJV and SCAB during extreme pollution events. In this study, the performance of the Weather Research and Forecasting Model (WRF) over these two regions for a summer month (July 2012) and a winter month (January 2013) is evaluated with different model configurations and forcing. Different land surface schemes (Pleim-Xiu vs. hybrid scheme), the application of observational and soil nudging, two SST datasets (the Global Ocean Data Assimilation Experiment (GODAE) SST vs. the default SST from North American Regional Reanalysis (NARR) reanalysis), and two land use datasets (the National Land Cover Data (NLCD) 2006 40-category vs. USGS 24-category land use data) have been tested. Model evaluation will focus on both surface and vertical profiles for wind, temperature, relative humidity, as well as PBLH. Sensitivity of the Community Multi-scale Air Quality Model (CMAQ) results to different WRF configurations will also be presented and discussed.

The influence of boreal spring Arctic Oscillation on the subsequent winter ENSO in CMIP5 models

Science.gov (United States)

Chen, Shangfeng; Chen, Wen; Yu, Bin

2017-05-01

This study examines the influence of boreal spring Arctic Oscillation (AO) on the subsequent winter El Niño-Southern Oscillation (ENSO) using 15 climate model outputs from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Results show that, out of the 15 CMIP5 models, CCSM4 and CNRM-CM5 can well reproduce the significant AO-ENSO connection. These two models capture the observed spring AO related anomalous cyclone (anticyclone) over the subtropical western-central North Pacific, and westerly (easterly) winds over the tropical western-central Pacific. In contrast, the spring AO-related anomalous circulation over the subtropical North Pacific is insignificant in the other 13 models, and the simulations in these models cannot capture the significant influence of the spring AO on ENSO. Further analyses indicate that the performance of the CMIP5 simulations in reproducing the AO-ENSO connection is related to the ability in simulating the spring North Pacific synoptic eddy intensity and the spring AO's Pacific component. Strong synoptic-scale eddy intensity results in a strong synoptic eddy feedback on the mean flow, leading to strong cyclonic circulation anomalies over the subtropical North Pacific, which contributes to a significant AO-ENSO connection. In addition, a strong spring AO's Pacific component and associated easterly wind anomalies to its south may provide more favorable conditions for the development of spring AO-related cyclonic circulation anomalies over the subtropical North Pacific.

Temporal and vertical variability in optical properties of New England shelf waters during late summer and spring

Science.gov (United States)

Sosik, Heidi M.; Green, Rebecca E.; Pegau, W. Scott; Roesler, Collin S.

2001-05-01

Relationships between optical and physical properties were examined on the basis of intensive sampling at a site on the New England continental shelf during late summer 1996 and spring 1997. During both seasons, particles were found to be the primary source of temporal and vertical variability in optical properties since light absorption by dissolved material, though significant in magnitude, was relatively constant. Within the particle pool, changes in phytoplankton were responsible for much of the observed optical variability. Physical processes associated with characteristic seasonal patterns in stratification and mixing contributed to optical variability mostly through effects on phytoplankton. An exception to this generalization occurred during summer as the passage of a hurricane led to a breakdown in stratification and substantial resuspension of nonphytoplankton particulate material. Prior to the hurricane, conditions in summer were highly stratified with subsurface maxima in absorption and scattering coefficients. In spring, stratification was much weaker but increased over the sampling period, and a modest phytoplankton bloom caused surface layer maxima in absorption and scattering coefficients. These seasonal differences in the vertical distribution of inherent optical properties were evident in surface reflectance spectra, which were elevated and shifted toward blue wavelengths in the summer. Some seasonal differences in optical properties, including reflectance spectra, suggest that a significant shift toward a smaller particle size distribution occurred in summer. Shorter timescale optical variability was consistent with a variety of influences including episodic events such as the hurricane, physical processes associated with shelfbreak frontal dynamics, biological processes such as phytoplankton growth, and horizontal patchiness combined with water mass advection.

Exceptional influenza morbidity in summer season of 2017 in Israel may predict the vaccine efficiency in the coming winter.

Science.gov (United States)

Pando, Rakefet; Sharabi, Sivan; Mandelboim, Michal

2018-03-07

Influenza infections are the leading cause of respiratory viral infections worldwide, and are mostly common in the winter season. The seasonal influenza vaccine is currently the most effective preventive modality against influenza infection. Immediately following each winter season the World Health Organization (WHO) announces the vaccine composition for the following winter. Unexpectedly, during the summer of 2017, in Israel, we observed in hospitalized patients, an exceptionally high numbers of Influenza positive cases. The majority of the influenza B infections were caused by influenza B/Yamagata lineage, which did not circulate in Israel in the previous winter, and most of the influenza A infections were caused by influenza A/H3N2, a strain similar to the strain that circulated in Israel in the previous winter. We therefore predict that these two viruses will circulate in the coming winter of 2017/18 and that the trivalent vaccine, which includes antigenically different viruses will be inefficient. Copyright © 2018 Elsevier Ltd. All rights reserved.

Winter Pea: Promising New Crop for Washington's Dryland Wheat-Fallow Region

Directory of Open Access Journals (Sweden)

William F. Schillinger

2017-05-01

Full Text Available A 2-year tillage-based winter wheat (Triticum aestivum L.-summer fallow (WW-SF rotation has been practiced by the vast majority of farmers in the low-precipitation (<300 mm annual rainfed cropping region of east-central Washington and north-central Oregon for 140 years. Until recently, alternative crops (i.e., those other than WW so far tested have not been as economically viable or stable as WW-SF. A 6-year field study was conducted near Ritzville, WA (292 mm avg. annual precipitation to determine the yield and rotation benefits of winter pea (Pisum sativum L. (WP. Two 3-year rotations were evaluated: WP-spring wheat (SW-SF vs. WW-SW-SF. Winter pea yields averaged 2,443 vs. 4,878 kg/ha for WW. No fertilizer was applied to WP whereas 56 kg N and 11 kg S/ha were applied to WW. Winter pea used significantly less soil water than WW. Over the winter months, a lesser percentage of precipitation was stored in the soil following WP compared to WW because: (i very little WP residue remained on the soil surface after harvest compared to WW, and (ii the drier the soil, the more precipitation is stored in the soil over winter. However, soil water content in the spring was still greater following WP vs. WW. Soil residual N in the spring (7 months after the harvest of WP and WW was greater in WP plots despite not applying fertilizer to produce WP. Spring wheat grown after both WP and WW received the identical quantity of N, P, and S fertilizer each year. Average yield of SW was 2,298 and 2,011 kg/ha following WP and WW, respectively (P < 0.01. Adjusted gross economic returns for these two rotation systems were similar. Based partially on the results of this study, numerous farmers in the dry WW-SF region have shown keen interest in WP and acreage planted WP in east-central Washington has grown exponentially since 2013. This paper provides the first report of the potential for WP in the typical WW-SF region of the inland Pacific Northwest (PNW.

Interannual variations of net community production and air-sea CO2 flux from winter to spring in the western subarctic North Pacific

International Nuclear Information System (INIS)

Midorikawa, Takashi; Ogawa, Kan; Nemoto, Kazuhiro; Kamiya, Hitomi; Umeda, Takafumi; Hiraishi, Naotaka; Wada, Akira; Ishii, Masao

2003-01-01

The role of spring biological production for the air-sea CO 2 flux was quantified in the Western Subarctic Gyre (48 deg N, 165 deg E), where the vertical profile of temperature revealed the existence of a temperature minimum (Tmin) layer in the North Pacific. The vertical profiles of temperature, salinity, dissolved oxygen, nutrients and dissolved inorganic carbon, DIC, in the upper water column were significantly variable year by year in spring, 1996-2000. Correspondingly, surface seawater at this site in spring was supersaturated with CO 2 in 1997, 1999 and 2000, but was undersaturated in 1996 and 1998. The concentrations of DIC and nutrients in the winter mixed layer were estimated from those in the Tmin layer in spring with a correction for particle decomposition based on the apparent oxygen utilization. The net community production (NCP) and air-sea CO 2 flux from winter to spring were calculated from the vertically integrated deficits of DIC and nutrients in the upper water column between the two seasons. The calculation of the carbon budget indicated large interannual variations of NCP (0-13 mmol/m 2 /d) and CO 2 efflux (4-16 mmol/m 2 /d) for this period. The CO 2 efflux was generally low in the year when NCP was high. The close coupling between biological production and CO 2 efflux suggested the important role of the changes in the mixed-layer depth, as a key process controlling both processes, especially of the timing, so that a decrease in the mixed-layer depth could result in the activation of biological production. The early biological consumption of the surface DIC concentration could shorten the period for acting as a source for atmospheric CO 2 and depress the CO 2 efflux in the Western Subarctic Gyre from winter to spring in 1996 and 1998. On the contrary, in 1997, persistently deep vertical mixing until late spring could suppress the biological activity and give rise to long-lasting CO 2 efflux

Development of groundwater pesticide exposure modeling scenarios for vulnerable spring and winter wheat-growing areas.

Science.gov (United States)

Padilla, Lauren; Winchell, Michael; Peranginangin, Natalia; Grant, Shanique

2017-11-01

Wheat crops and the major wheat-growing regions of the United States are not included in the 6 crop- and region-specific scenarios developed by the US Environmental Protection Agency (USEPA) for exposure modeling with the Pesticide Root Zone Model conceptualized for groundwater (PRZM-GW). The present work augments the current scenarios by defining appropriately vulnerable PRZM-GW scenarios for high-producing spring and winter wheat-growing regions that are appropriate for use in refined pesticide exposure assessments. Initial screening-level modeling was conducted for all wheat areas across the conterminous United States as defined by multiple years of the Cropland Data Layer land-use data set. Soil, weather, groundwater temperature, evaporation depth, and crop growth and management practices were characterized for each wheat area from publicly and nationally available data sets and converted to input parameters for PRZM. Approximately 150 000 unique combinations of weather, soil, and input parameters were simulated with PRZM for an herbicide applied for postemergence weed control in wheat. The resulting postbreakthrough average herbicide concentrations in a theoretical shallow aquifer were ranked to identify states with the largest regions of relatively vulnerable wheat areas. For these states, input parameters resulting in near 90 th percentile postbreakthrough average concentrations corresponding to significant wheat areas with shallow depth to groundwater formed the basis for 4 new spring wheat scenarios and 4 new winter wheat scenarios to be used in PRZM-GW simulations. Spring wheat scenarios were identified in North Dakota, Montana, Washington, and Texas. Winter wheat scenarios were identified in Oklahoma, Texas, Kansas, and Colorado. Compared to the USEPA's original 6 scenarios, postbreakthrough average herbicide concentrations in the new scenarios were lower than all but Florida Potato and Georgia Coastal Peanuts of the original scenarios and better

Airborne dust distribution in a farrowing pen in dependence of other microclimatic parameters during spring-summer period

Directory of Open Access Journals (Sweden)

Boris Antunović

2010-01-01

Full Text Available The study was carried out in a farrowing pen during 6 production cycles of 24 days in the spring-summer period. The effect of season and other microclimate parameters on airborne dust concentration was investigated. Study results showed a decrease in airborne dust concentration in summer period that yielded negative correlation with air temperature (P<0.05. Relative humidity was expected to decrease due to higher ventilation rates, however, a significant increase was recorded in summer (P<0.05 because of higher evaporation caused by floor wash. The decrease in airborne dust concentration was ascribed to temperature elevation due to intensified ventilation rate and relative humidity resulting in higher rate of dust settling.

Investigations into the Early Life History of Naturally Produced Spring Chinook Salmon in the Grande Ronde River Basin : Fish Research Project Oregon : Annual Progress Report Project Period 1 September 1998 to 31 August 1999.

Energy Technology Data Exchange (ETDEWEB)

Jonasson, Brian C.

2000-01-01

We determined migration timing and abundance of juvenile spring chinook salmon from three populations in the Grande Ronde River basin. We estimated 13,180 juvenile chinook salmon left upper rearing areas of the Grande Ronde River from July 1998 to June 1999; approximately 0.2% of the migrants left in summer, 18% in fall and 82% in spring. We estimated 15,949 juvenile chinook salmon left upper rearing areas of Catherine Creek from July 1998 to June 1999; approximately 0.2% of the migrants left in summer, 57% in fall, 2% in winter, and 41% in spring. We estimated 14,537 juvenile chinook salmon left the Grande Ronde Valley, located below the upper rearing areas in Catherine Creek and the Grande Ronde River, from October 1998 to June 1999; approximately 99% of the migrants left in spring. We estimated 31,113 juvenile chinook salmon left upper rearing areas of the Lostine River from July 1998 to June 1999; approximately 4% of the migrants left in summer, 57% in fall, 3% in winter, and 36% in spring. We estimated 42,705 juvenile spring chinook salmon left the Wallowa Valley, located below the mouth of the Lostine River, from August 1998 to June 1999; approximately 46% of the migrants left in fall, 6% in winter, and 47% in spring. Juvenile chinook salmon PIT-tagged on the upper Grande Ronde River were detected at Lower Granite Dam from 31 March to 20 June 1999, with a median passage date of 5 May. PIT-tagged salmon from Catherine Creek were detected at Lower Granite Dam from 19 April to 9 July 1999, with a median passage date of 24 May. PIT-tagged salmon from the Lostine River were detected at Lower Granite Dam from 31 March through 8 July 1999, with a median passage date of 4 May. Juveniles tagged as they left the upper rearing areas of the Grande Ronde River in fall and that overwintered in areas downstream were detected in the hydrosystem at a higher rate than fish tagged during winter in the upper rearing areas, indicating a higher overwinter survival in the

A distinction between summer rainy season and summer monsoon season over the Central Highlands of Vietnam

Science.gov (United States)

Ngo-Thanh, Huong; Ngo-Duc, Thanh; Nguyen-Hong, Hanh; Baker, Peter; Phan-Van, Tan

2018-05-01

The daily rainfall data at 13 stations over the Central Highlands (CH) Vietnam were collected for the period 1981-2014. Two different sets of criteria using daily observed rainfall and 850 hPa daily reanalysis wind data were applied to determine the onset (retreat) dates of the summer rainy season (RS) and summer monsoon (SM) season, respectively. Over the study period, the mean RS and SM onset dates were April 20 and May 13 with standard deviations of 17.4 and 17.8 days, respectively. The mean RS and SM retreat dates were November 1 and September 30 with standard deviations of 17.9 and 10.2 days, respectively . The year-to-year variations of the onset dates and the rainfall amount within the RS and SM season were closely linked with the preceding winter and spring sea surface temperature in the central-eastern and western Pacific. It was also found that the onset dates were significantly correlated with the RS and SM rainfall amount.

Controls on summer low flow

Science.gov (United States)

Graham, C. B.; McNamara, J. P.

2012-12-01

Summer low flow has significant impacts on aquatic flora and fauna, municipal water use, and power generation. However, the controls on the minimum annual summer discharge are complex, including a combination of snowmelt dynamics, summer evapotranspiration demand, and spring, summer precipitation patterns and surface - groundwater interactions. This is especially true in the Rocky Mountain West of the United States, where snowpack provides the majority of water available for spring runoff and groundwater replenishment. In this study, we look at summer low flow conditions at four snow dominated catchments (26 km2 - 2200 km2) in South-central Idaho currently feeling the effects of climate change. Measures of snowmelt dynamics, summer evapotranspiration demand and spring and summer precipitation are used to determine the dominant controls on late summer low flow magnitude, timing and duration. These analyses show that the controls vary between watersheds, with significant implications for the impacts of climate change in snow dominated areas of the Rocky Mountain West.

The nitrate leached below maize root zone is available for deep-rooted wheat in winter wheat-summer maize rotation in the North China Plain

Energy Technology Data Exchange (ETDEWEB)

Zhou Shunli [Key Laboratory of Crop Cultivation and Farming System, Ministry of Agriculture, College of Agronomy and Biotechnology, China Agricultural University, 2 West Yuanmingyuan Road, Beijing 100094 (China)], E-mail: zhoushl@cau.edu.cn; Wu Yongcheng [Key Laboratory of Crop Cultivation and Farming System, Ministry of Agriculture, College of Agronomy and Biotechnology, China Agricultural University, 2 West Yuanmingyuan Road, Beijing 100094 (China); College of Agronomy, Si Chuan Agricultural University, Yaan 625014 (China); Wang Zhimin [Key Laboratory of Crop Cultivation and Farming System, Ministry of Agriculture, College of Agronomy and Biotechnology, China Agricultural University, 2 West Yuanmingyuan Road, Beijing 100094 (China); Lu Laiqing; Wang Runzheng [Wuqiao Experimental Station, China Agricultural University, Hebei 061802 (China)

2008-04-15

In winter wheat (Triticum aestivum L.)-summer maize (Zea mays L.) rotation system in the North China Plain, maize roots do not extend beyond 1.2 m in the vertical soil profile, but wheat roots can reach up to 2.0 m. Increases in soil nitrate content at maize harvest and significant reductions after winter wheat harvest were observed in the 1.4-2.0 m depth under field conditions. The recovery of {sup 15}N isotope (calcium nitrate) from various (1.0, 1.2, 1.4, 1.6, 1.8 and 2.0 m) soil depths showed that deep-rooting winter wheat could use soil nitrate up to the 2.0 m depth. This accounted partially, for the reduced nitrate in the 1.4-2.0 m depth of the soil after harvest of wheat in the rotation system. - Deep-rooted wheat can recycle nitrate leached from maize root zone in winter wheat-summer maize rotation system.

The nitrate leached below maize root zone is available for deep-rooted wheat in winter wheat-summer maize rotation in the North China Plain

International Nuclear Information System (INIS)

Zhou Shunli; Wu Yongcheng; Wang Zhimin; Lu Laiqing; Wang Runzheng

2008-01-01

In winter wheat (Triticum aestivum L.)-summer maize (Zea mays L.) rotation system in the North China Plain, maize roots do not extend beyond 1.2 m in the vertical soil profile, but wheat roots can reach up to 2.0 m. Increases in soil nitrate content at maize harvest and significant reductions after winter wheat harvest were observed in the 1.4-2.0 m depth under field conditions. The recovery of 15 N isotope (calcium nitrate) from various (1.0, 1.2, 1.4, 1.6, 1.8 and 2.0 m) soil depths showed that deep-rooting winter wheat could use soil nitrate up to the 2.0 m depth. This accounted partially, for the reduced nitrate in the 1.4-2.0 m depth of the soil after harvest of wheat in the rotation system. - Deep-rooted wheat can recycle nitrate leached from maize root zone in winter wheat-summer maize rotation system

Diurnal and spatial (vertical dynamics of nutrients (N, P, Si in four sampling days (summer, fall, winter, and spring in a tropical shallow reservoir and their relationships with the phytoplankton community

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J. J. Ramírez

Full Text Available The vertical and diurnal variation of nitrogen and phosphorus forms, as well as that of soluble reactive silica (SRS, were studied in four sampling days at Garças reservoir, a shallow tropical one located in the city of São Paulo, in southeastern Brazil. Except for N-NH4, all other inorganic forms of nitrogen (N-NO2, N-NO3, and total N demonstrated decreased concentrations toward the bottom of reservoir. Similarly, all showed significant diurnal differences on every sampling day, with increased values during the night due to absence of photosynthetic assimilation during that period. In the sampling days, these forms decreased on the spring sampling day due to the bloom of Microcystis registered during this period of the year. All three forms of phosphorus (SRP, particulate P, and total P showed significant vertical variation, except on the fall sampling day. On the summer sampling day there was an increase of both total P and particulate P, the latter because it constitutes more than 70% of the total P during all sampling days. Hourly phosphorus variation was significant during all sampling days, except for the summer one. The SRS vertical variation was significant during all sampling days, except for that in the spring. It was also different hourly on sampling days.

Virus Status, Varroa Levels, and Survival of 20 Managed Honey Bee Colonies Monitored in Luxembourg Between the Summer of 2011 and the Spring of 2013

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Clermont Antoine

2015-06-01

Full Text Available Twenty managed honey bee colonies, split between 5 apiaries with 4 hives each, were monitored between the summer of 2011 and spring of 2013. Living bees were sampled in July 2011, July 2012, and August 2012. Twenty-five, medium-aged bees, free of varroa mites, were pooled per colony and date, to form one sample. Unlike in France and Belgium, Chronic Bee Paralysis Virus (CBPV has not been found in Luxembourg. Slow Bee Paralysis Virus (SBPV and Israeli Acute Paralysis Virus (IAPV levels were below detection limits. Traces of Kashmir Bee Virus (KBV were amplified. Black Queen Cell Virus (BQCV, Varroa destructor Virus-1 (VDV-1, and SacBrood Virus (SBV were detected in all samples and are reported from Luxembourg for the first time. Varroa destructor Macula- Like Virus (VdMLV, Deformed Wing Virus (DWV, and Acute Bee Paralysis Virus (ABPV were detected at all locations, and in most but not all samples. There was a significant increase in VDV-1 and DWV levels within the observation period. A principal component analysis was unable to separate the bees of colonies that survived the following winter from bees that died, based on their virus contents in summer. The number of dead varroa mites found below colonies was elevated in colonies that died in the following winter. Significant positive relationships were found between the log-transformed virus levels of the bees and the log-transformed number of mites found below the colonies per week, for VDV-1 and DWV. Sacbrood virus levels were independent of varroa levels, suggesting a neutral or competitive relationship between this virus and varroa.

Simulating the formation of carbonaceous aerosol in a European Megacity (Paris) during the Megapoli summer and winter campaigns

NARCIS (Netherlands)

Fountoukis, C.; Megaritis, A.G.; Skyllakou, K.; Charalampidis, P.E.; Denier van der Gon, H.A.C.; Crippa, M.; Prevot, A.S.H.; Fachinger, F.; Wiedensohler, A.; Pilinis, C.; Pandis, S.N.

2016-01-01

We use a three-dimensional regional chemical transport model (PMCAMx) with high grid resolution and high-resolution emissions (4 x 4 km2) over the Paris greater area to simulate the formation of carbonaceous aerosol dur-ing a summer (July 2009) and a winter (January/February 2010) period as part of

Contribution of biogenic and photochemical sources to ambient VOCs during winter to summer transition at a semi-arid urban site in India.

Science.gov (United States)

Sahu, L K; Tripathi, Nidhi; Yadav, Ravi

2017-10-01

This paper presents the sources and characteristics of ambient volatile organic compounds (VOCs) measured using PTR-TOF-MS instrument in a metropolitan city of India during winter to summer transition period. Mixing ratios of VOCs exhibited strong diurnal, day-to-day and episodic variations. Methanol was the most dominant species with monthly mean values of 18-22 pbbv. The emission ratios of VOCs relative to benzene calculated from nighttime data were used to estimate the relative contributions of vehicle exhaust and other sources. The increasing daytime ratios of oxygenated-VOCs (OVOCs)/benzene and isoprene/benzene from February to March indicates increasing contribution of photo-oxidation and biogenic sources. Daytime fractions of acetone (18%), acetaldehyde (15%) and isoprene (4.5%) to the sum of measured VOCs in March were higher than those in February. Variations of VOCs at lower temperatures (biogenic emissions. The emissions of OVOCs from vehicle exhaust were estimated to be smaller (20-40%) than those from other sources. The contributions of biogenic and secondary sources to OVOCs and isoprene increased by 10-15% from winter to summer. This study provides evidence that the winter-to-summer transition has an impact on sources and composition of VOCs in tropical urban areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Decadal variability in snow depth anomaly over Eurasia and its association with all India summer monsoon rainfall and seasonal circulations

CERN Document Server

Singh, G P

2003-01-01

The Historical Soviet Daily Snow Depth (HSDSD) version II data set has been used in the computation of winter and spring snow depth anomalies over west (25 deg. E to 70 deg. E, 35 deg. N to 65 deg. N) and east (70 deg. E to 160 deg. E, 35 deg. N to 65 deg. N) Eurasia. It is noticed that winter snow depth anomaly over east Eurasia is positively correlated while west Eurasia is negatively correlated with subsequent Indian summer monsoon rainfall (ISMR). The DJF snow depth anomaly shows highest and inverse correlation coefficient (CC) with ISMR over a large area of west Eurasia in a recent period of study i.e. 1975-1995. On the basis of standardised winter (mean of December, January and February) snow depth anomaly over west Eurasia, the years 1966, 1968, 1979 and 1986 are identified as high snow years and the years 1961 and 1975 as low snow years. The characteristics of seasonal monsoon circulation features have been studied in detail during contrasting years of less (more) snow depth in winter/spring seasons f...

Variational Data Assimilative Modeling of the Gulf of Maine Circulation in Spring and Summer 2010

OpenAIRE

Li, Yizhen; He, Ruoying; Chen, Ke; McGillicuddy, Dennis J.

2015-01-01

A data assimilative ocean circulation model is used to hindcast the Gulf of Maine (GOM) circulation in spring and summer 2010. Using the recently developed incremental strong constraint 4D Variational data assimilation algorithm, the model assimilates satellite sea surface temperature and in situ temperature and salinity profiles measured by expendable bathythermograph, Argo floats, and shipboard CTD casts. Validation against independent observations shows that the model skill is significantl...

Ecological Weed Management by Cover Cropping: Effect on Winter Weeds and Summer Weeds Establishment in Potato

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M Ghaffari

2012-07-01

Full Text Available Now a day winter cover crops planting has been attended to reduce herbicide application. An experiment was carried out at the Research Farm of Agriculture Faculty, Bu- Ali Sina, University, in 2009. The experiment was a randomized complete block design with three replications. The trial included of five treatments consists of no cover crop, rye, winter oilseed rape, barley and triticale. The results showed that winter cereals were produced more biomass than winter oilseed rape. living mulch of rye, barley, oilseed rape and triticale reduced winter weeds biomass 89, 86, 82 and 70 percent respectively, in compare to control. Cover crop treatments showed significant different weeds control of potato at 3 time (15, 45 and 75 DAPG compare to control treatment. Residues mixed to soil of oilseed rape and rye had the most inhibition affects on summer weeds. These treatments, average weeds biomass decreased 61 and 57 percent respectively, in compare to control. Oilseed rape and rye in compare to control reduced weeds density in potato 36 and 35 percent, respectively. Significant negation correlations of weeds plant population, weeds dry matter with average tuber weight and potato yield. The treatments, oilseed rape and rye in compare to control increased tuber yield of potato 54 and 50 percent, respectively. These treatments, the average tuber weight increased 74 and 38 percent in compare with control, respectively.

Summer and Winter Effect of Innovative Cool Roof Tiles on the Dynamic Thermal Behavior of Buildings

Directory of Open Access Journals (Sweden)

Anna Laura Pisello

2014-04-01

Full Text Available Cool roofs represent an acknowledged passive cooling technique to reduce building energy consumption for cooling and to mitigate urban heat island effects. This paper concerns the evaluation of the dynamic effect of new cool roof clay tiles on building thermal performance in summer and winter conditions. To this end, these properties have been analyzed on traditional roof brick tiles through an indoor and outdoor two-year long continuous monitoring campaign set up in a residential building located in central Italy. The analysis and the cooperation with industrial companies producing brick tiles and reflective coatings allowed the production of a new tile with notable “cool roof” properties through the traditional industrial manufacturing path of such tiles. Notable results show that during summer the high reflection tiles are able to decrease the average external roof surface temperature by more than 10 °C and the indoor operative temperature by more than 3 °C. During winter the average external surface temperature is lower with high reflection tiles by about 1 °C. Singular optic-thermal phenomena are registered while evaluating the dynamics of the cool roof effect. Interesting findings show how the sloped cool roof application could suggest further considerations about the dynamic effect of cool roofs.

Investigation of Microphysical Parameters within Winter and Summer Type Precipitation Events over Mountainous [Complex] Terrain

International Nuclear Information System (INIS)

Stalker, James R.; Bossert, James E.

1997-10-01

In this study we investigate complex terrain effects on precipitation with RAMS for both in winter and summer cases from a microphysical perspective. We consider a two dimensional east-west topographic cross section in New Mexico representative of the Jemez mountains on the west and the Sangre de Cristo mountains on the east. Located between these two ranges is the Rio Grande Valley. In these two dimensional experiments, variations in DSDs are considered to simulate total precipitation that closely duplicate observed precipitation

Contrasting effects of summer and winter warming on body mass explain population dynamics in a food-limited Arctic herbivore.

Science.gov (United States)

Albon, Steve D; Irvine, R Justin; Halvorsen, Odd; Langvatn, Rolf; Loe, Leif E; Ropstad, Erik; Veiberg, Vebjørn; van der Wal, René; Bjørkvoll, Eirin M; Duff, Elizabeth I; Hansen, Brage B; Lee, Aline M; Tveraa, Torkild; Stien, Audun

2017-04-01

The cumulative effects of climate warming on herbivore vital rates and population dynamics are hard to predict, given that the expected effects differ between seasons. In the Arctic, warmer summers enhance plant growth which should lead to heavier and more fertile individuals in the autumn. Conversely, warm spells in winter with rainfall (rain-on-snow) can cause 'icing', restricting access to forage, resulting in starvation, lower survival and fecundity. As body condition is a 'barometer' of energy demands relative to energy intake, we explored the causes and consequences of variation in body mass of wild female Svalbard reindeer (Rangifer tarandus platyrhynchus) from 1994 to 2015, a period of marked climate warming. Late winter (April) body mass explained 88% of the between-year variation in population growth rate, because it strongly influenced reproductive loss, and hence subsequent fecundity (92%), as well as survival (94%) and recruitment (93%). Autumn (October) body mass affected ovulation rates but did not affect fecundity. April body mass showed no long-term trend (coefficient of variation, CV = 8.8%) and was higher following warm autumn (October) weather, reflecting delays in winter onset, but most strongly, and negatively, related to 'rain-on-snow' events. October body mass (CV = 2.5%) increased over the study due to higher plant productivity in the increasingly warm summers. Density-dependent mass change suggested competition for resources in both winter and summer but was less pronounced in recent years, despite an increasing population size. While continued climate warming is expected to increase the carrying capacity of the high Arctic tundra, it is also likely to cause more frequent icing events. Our analyses suggest that these contrasting effects may cause larger seasonal fluctuations in body mass and vital rates. Overall our findings provide an important 'missing' mechanistic link in the current understanding of the population biology of a

Using mortality compost in vegetable production: A comparison between summer and winter composting and its use in cabbage production

Science.gov (United States)

A study was conducted to determine the effectiveness of composting to breakdown the carcasses of daily poultry mortality and in the process destroy pathogenic microorganisms that may be present. The study was conducted during the summer and repeated in the winter to determine whether the time of yea...

New winter hardy winter bread wheat cultivar (Triticum aestivum L. Voloshkova

Directory of Open Access Journals (Sweden)

Л. М. Голик

2007-12-01

Full Text Available Creation of Initial raw for breeding of winter wheat by change of the development type under low temperatures influence was described. Seeds of spring wheat were vernalized in aluminum weighting bottle. By using low temperatures at sawing of M2-6 at the begin ind of optimal terms of sawing of winter wheat, new winter-hardy variety of Voloshkova was bred.

Dispersion of atmospheric air pollution in summer and winter season.

Science.gov (United States)

Cichowicz, Robert; Wielgosiński, Grzegorz; Fetter, Wojciech

2017-11-04

Seasonal variation of air pollution is associated with variety of seasons and specificity of particular months which form the so-called summer and winter season also known as the "heating" season. The occurrence of higher values of air pollution in different months of a year is associated with the type of climate, and accordingly with different atmospheric conditions in particular months, changing state of weather on a given day, and anthropogenic activity. The appearance of these conditions results in different levels of air pollution characteristic for a given period. The study uses data collected during a seven-year period (2009-2015) in the automatic measuring station of immissions located in Eastern Wielkopolska. The analysis concerns the average and maximum values of air pollution (i.e., particulate matter PM10, sulfur dioxide, nitrogen dioxide, carbon monoxide, and ozone) from the perspective of their occurrence in particular seasons and months or in relation to meteorological actors such as temperature, humidity, and wind speed.

Winter metabolic depression does not change arterial baroreflex control of heart rate in the tegu lizard Salvator merianae.

Science.gov (United States)

Zena, Lucas A; Dantonio, Valter; Gargaglioni, Luciane H; Andrade, Denis V; Abe, Augusto S; Bícego, Kênia C

2016-03-01

Baroreflex regulation of blood pressure is important for maintaining appropriate tissue perfusion. Although temperature affects heart rate (fH) reflex regulation in some reptiles and toads, no data are available on the influence of temperature-independent metabolic states on baroreflex. The South American tegu lizard Salvator merianae exhibits a clear seasonal cycle of activity decreasing fH along with winter metabolic downregulation, independent of body temperature. Through pharmacological interventions (phenylephrine and sodium nitroprusside), the baroreflex control of fH was studied at ∼ 25 °C in spring-summer- and winter-acclimated tegus. In winter lizards, resting and minimum fH were lower than in spring-summer animals (respectively, 13.3 ± 0.82 versus 10.3 ± 0.81 and 11.2 ± 0.65 versus 7.97 ± 0.88 beats min(-1)), while no acclimation differences occurred in resting blood pressure (5.14 ± 0.38 versus 5.06 ± 0.56 kPa), baroreflex gain (94.3 ± 10.7 versus 138.7 ± 30.3% kPa(-1)) or rate-pressure product (an index of myocardial activity). Vagal tone exceeded the sympathetic tone of fH, especially in the winter group. Therefore, despite the lower fH, winter acclimation does not diminish the fH baroreflex responses or rate-pressure product, possibly because of increased stroke volume that may arise because of heart hypertrophy. Independent of acclimation, fH responded more to hypotension than to hypertension. This should imply that tegus, which have no pressure separation within the single heart ventricle, must have other protection mechanisms against pulmonary hypertension or oedema, presumably through lymphatic drainage and/or vagal vasoconstriction of pulmonary artery. Such a predominant fH reflex response to hypotension, previously observed in anurans, crocodilians and mammals, may be a common feature of tetrapods. © 2016. Published by The Company of Biologists Ltd.

Cryopreservation of Adult Male Spring and Summer Chinook Salmon Gametes in the Snake River Basin, 1997 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Faurot, Dave; Kucera, Paul A.; Armstrong, Robyn D. (Nez Perce Tribe, Lapwai, ID)

1998-06-01

Chinook salmon populations in the Northwest are decreasing in number. The Nez Perce Tribe was funded in 1997 by the Bonneville Power Administration to coordinate and initiate gene banking of adult male gametes from Endangered Species Act (ESA) listed spring and summer chinook salmon in the Snake River basin.

Clinical research of acupoint application for "treatment of winter disease in summer" used to prevent and treat bronchial asthma in children.

Science.gov (United States)

Wen, Bi-Ling; Liu, Bao-Yan; Jin, Peng; Wang, Xue-Feng; Xiang, Xi-Xiong; Liu, Xiao-Fan; Hu, Jing-Qing; Lu, Fang; He, Li-Yun; Zhu, Wen-Zeng; Fang, Yi-Gong; Wang, Yu

2012-03-01

To preliminarily analyze key factors influencing curative effect through clinical observations of acupoint application for "treatment of winter disease in summer" used to prevent and treat bronchial asthma in children. In an observational study and prospective cohort study, we observed children in remission of asthma at three class III grade A TCM hospitals in Liaoning, Hubei, and Chengdu. A total of 609 children conformed to diagnostic and inclusive standards for remission of bronchial asthma. Through follow-up visits, we observed their skin reactions and the time and chance of treatment with different therapies in the three hospitals; we also compared and analyzed different drugs, acupoints, and preparations. We found that the key Chinese drugs were Bai Jie Zi (Semen Sinapis Albae) and Yian Hu Suo (Rhizoma Corydalis); the key acupoints were Feishu (BL 13), Gaohuang (BL 43), Dingchuan (EX-B1), Tiantu (CV 22), and Shanzhong (CV 17); and the best preparation was a mixture of drugs, ginger juice, and musk. Acupoint application was practiced on the hottest days of summer and the coldest days of winter for 0.5 to 2 h with the lowest rate of asthma relapse. The present data analysis shows that the curative effect of acupoint application for "treatment of winter disease in summer" may be influenced by recipes of Chinese drugs, preparations, prescriptions of acupoints, chance, time, and skin reactions. A curative effect is the result of the comprehensive action of these factors.

Ornithological studies of the Cold Northcott Wind Farm in the spring/summer 1994

International Nuclear Information System (INIS)

1996-01-01

Results of ornithological studies carried out at Cold Northcott Wind Farm in North Cornwall during 1994 are presented. Flight patterns of species using the area were studied as were breeding patterns and bird mortality due to collisions with wind turbines. No significant effect on the spring and summer bird communities was observed. Long-term influences on the birds seem, rather, to stem from large scale population changes and local agricultural practice. Wind strength was shown to affect flight patterns in some species, but turbine operation seems unrelated. Death by collision with wind turbines is shown to be very rare. (UK)

Investigations into the Early Life-history of Naturally Produced Spring Chinook Salmon and Summer Steelhead in the Grande Ronde River Basin, Annual Report 2001.

Energy Technology Data Exchange (ETDEWEB)

Reischauer, Alyssa; Monzyk, Frederick; Van Dyke, Erick

2003-06-01

approximately 14% of these fish leaving as early migrants. Juvenile spring chinook salmon PIT-tagged at trap sites in the fall and in upper rearing areas during winter were used to compare migration timing and survival to Lower Granite Dam of the early and late migrant groups. Juvenile spring chinook tagged on the upper Grande Ronde River were detected at Lower Granite Dam from 4 May to 20 May 2001, with a median passage date of 17 May. Too few fish were collected and tagged to conduct detection rate and survival comparisons between migrant groups. PIT-tagged salmon from Catherine Creek trap were detected at Lower Granite Dam from 27 April to 13 July 2001. Early migrants were detected significantly earlier (median = 10 May) than late migrants (median = 1 June). Also, early migrants from Catherine Creek were detected at a significantly higher rate than fish tagged in upper rearing areas in the winter, suggesting better survival for fish that migrated out of upper rearing areas in the fall. Juvenile spring chinook salmon from the Lostine River were detected at Lower Granite Dam from 2 April through 4 July 2001. Early migrants were detected significantly earlier (median = 27 April) than late migrants (median = 14 May). However, there was no difference in detection rates between early and late migrants. Survival probabilities showed similar patterns as dam detection rates. Juvenile spring chinook salmon from the Minam River were detected at Lower Granite Dam from 8 April through 18 August 2001. Early migrants were detected significantly earlier (median = 28 April) than late migrants (median = 14 May). Late migrants from the Minam River were tagged at the trap in the spring. Spring chinook salmon parr PIT-tagged in summer 2000 on Catherine Creek and the Imnaha, Lostine, and Minam rivers were detected at Lower Granite Dam over an 87 d period from 8 April to 3 July 2001. The migratory period of individual populations ranged from 51 d (Imnaha River) to 67 d (Catherine Creek) in length

Association of spring-summer hydrology and meteorology with human West Nile virus infection in West Texas, USA, 2002-2016.

Science.gov (United States)

Ukawuba, Israel; Shaman, Jeffrey

2018-04-04

The emergence of West Nile virus (WNV) in the Western Hemisphere has motivated research into the processes contributing to the incidence and persistence of the disease in the region. Meteorology and hydrology are fundamental determinants of vector-borne disease transmission dynamics of a region. The availability of water influences the population dynamics of vector and host, while temperature impacts vector growth rates, feeding habits, and disease transmission potential. Characterization of the temporal pattern of environmental factors influencing WNV risk is crucial to broaden our understanding of local transmission dynamics and to inform efforts of control and surveillance. We used hydrologic, meteorological and WNV data from west Texas (2002-2016) to analyze the relationship between environmental conditions and annual human WNV infection. A Bayesian model averaging framework was used to evaluate the association of monthly environmental conditions with WNV infection. Findings indicate that wet conditions in the spring combined with dry and cool conditions in the summer are associated with increased annual WNV cases. Bayesian multi-model inference reveals monthly means of soil moisture, specific humidity and temperature to be the most important variables among predictors tested. Environmental conditions in March, June, July and August were the leading predictors in the best-fitting models. The results significantly link soil moisture and temperature in the spring and summer to WNV transmission risk. Wet spring in association with dry and cool summer was the temporal pattern best-describing WNV, regardless of year. Our findings also highlight that soil moisture may be a stronger predictor of annual WNV transmission than rainfall.

Nitrogen Uptake During Fall, Winter and Spring Differs Among Plant Functional Groups in a Subarctic Heath Ecosystem

DEFF Research Database (Denmark)

Larsen, Klaus Steenberg; Michelsen, Anders; Jonasson, Sven

2012-01-01

Nitrogen (N) is a critical resource for plant growth in tundra ecosystems, and species differences in the timing of N uptake may be an important feature regulating community composition and ecosystem productivity. We added 15N-labelled glycine to a subarctic heath tundra dominated by dwarf shrubs...... to 37 ± 7% by April indicating significant microbial N turnover prior to spring thaw. Only the evergreen dwarf shrubs showed active 15N acquisition before early May indicating that they had the highest potential of all functional groups for acquiring nutrients that became available in early spring....... The faster-growing deciduous shrubs did not resume 15N acquisition until after early May indicating that they relied more on nitrogen made available later during the spring/early summer. The graminoids and mosses had no significant increases in 15N tracer recovery or tissue 15N tracer concentrations after...

Investigations into the Early Life History of Naturally Spring Chinook Salmon in the Grande Ronde River Basin : Fish Research Project Oregon : Annual Progress Report Project Period 1 September 1997 to 31 August 1998.

Energy Technology Data Exchange (ETDEWEB)

Keefe, MaryLouise; Tranquilli, J. Vincent

1998-01-01

We determined migration timing and abundance of juvenile spring chinook salmon from three populations in the Grande Ronde River basin. We estimated 6,716 juvenile chinook salmon left upper rearing areas of the Grande Ronde River from July 1997 to June 1998; approximately 6% of the migrants left in summer, 29% in fall, 2% in winter, and 63% in spring. We estimated 8,763 juvenile chinook salmon left upper rearing areas of Catherine Creek from July 1997 to June 1998; approximately 12% of the migrants left in summer, 37% in fall, 21% in winter, and 29% in spring. We estimated 8,859 juvenile chinook salmon left the Grande Ronde Valley, located below the upper rearing areas in Catherine Creek and the Grande Ronde River, from October 1997 to June 1998; approximately 99% of the migrants left in spring. We estimated 15,738 juvenile chinook salmon left upper rearing areas of the Lostine River from July 1997 to April 1998; approximately 3% of the migrants left in summer, 61% in fall, 2% in winter, and 34% in spring. We estimated 22,754 juvenile spring chinook salmon left the Wallowa Valley, located below the mouth of the Lostine River, from September 1997 to April 1998; approximately 55% of the migrants left in fall, 5% in winter, and 40% in spring. Juvenile chinook salmon PIT-tagged on the upper Grande Ronde River were detected at Lower Granite Dam from 4 April to 26 June 1998, with a median passage date of 1 May. PIT-tagged salmon from Catherine Creek were detected at Lower Granite Dam from 3 April to 26 June 1998, with a median passage date of 8 May. PIT-tagged salmon from the Lostine River were detected at Lower Granite Dam from 31 March through 26 May 1998, with a median passage date of 28 April. Juveniles tagged as they left the upper rearing areas of the Grande Ronde and Lostine rivers in fall and that overwintered in areas downstream were detected in the hydrosystem at a higher rate than fish tagged during winter in the upper rearing areas, indicating a higher

Winter Survival of Individual Honey Bees and Honey Bee Colonies Depends on Level of Varroa destructor Infestation

Science.gov (United States)

van Dooremalen, Coby; Gerritsen, Lonne; Cornelissen, Bram; van der Steen, Jozef J. M.; van Langevelde, Frank; Blacquière, Tjeerd

2012-01-01

Background Recent elevated winter loss of honey bee colonies is a major concern. The presence of the mite Varroa destructor in colonies places an important pressure on bee health. V. destructor shortens the lifespan of individual bees, while long lifespan during winter is a primary requirement to survive until the next spring. We investigated in two subsequent years the effects of different levels of V. destructor infestation during the transition from short-lived summer bees to long-lived winter bees on the lifespan of individual bees and the survival of bee colonies during winter. Colonies treated earlier in the season to reduce V. destructor infestation during the development of winter bees were expected to have longer bee lifespan and higher colony survival after winter. Methodology/Principal Findings Mite infestation was reduced using acaricide treatments during different months (July, August, September, or not treated). We found that the number of capped brood cells decreased drastically between August and November, while at the same time, the lifespan of the bees (marked cohorts) increased indicating the transition to winter bees. Low V. destructor infestation levels before and during the transition to winter bees resulted in an increase in lifespan of bees and higher colony survival compared to colonies that were not treated and that had higher infestation levels. A variety of stress-related factors could have contributed to the variation in longevity and winter survival that we found between years. Conclusions/Significance This study contributes to theory about the multiple causes for the recent elevated colony losses in honey bees. Our study shows the correlation between long lifespan of winter bees and colony loss in spring. Moreover, we show that colonies treated earlier in the season had reduced V. destructor infestation during the development of winter bees resulting in longer bee lifespan and higher colony survival after winter. PMID:22558421

Winter rye as a bioenergy feedstock: impact of crop maturity on composition, biological solubilization and potential revenue.

Science.gov (United States)

Shao, Xiongjun; DiMarco, Kay; Richard, Tom L; Lynd, Lee R

2015-01-01

Winter annual crops such as winter rye (Secale cereale L) can produce biomass feedstock on seasonally fallow land that continues to provide high-value food and feed from summer annuals such as corn and soybeans. As energy double crops, winter grasses are likely to be harvested while still immature and thus structurally different from the fully senesced plant material typically used for biofuels. This study investigates the dynamic trends in biomass yield, composition, and biological solubilization over the course of a spring harvest season. The water soluble fraction decreased with increasing maturity while total carbohydrate content stayed roughly constant at about 65%. The protein mass fraction decreased with increasing maturity, but was counterbalanced by increasing harvest yield resulting in similar total protein across harvest dates. Winter rye was ground and autoclaved then fermented at 15 g/L total solids by either (1) Clostridium thermocellum or (2) simultaneous saccharification and cofermentation (SSCF) using commercial cellulases (CTec2 and HTec2) and a xylose-fermenting Saccharomyces cerevisiae strain. Solubilization of total carbohydrate dropped significantly as winter rye matured for both C. thermocellum (from approximately 80% to approximately 50%) and SSCF (from approximately 60% to approximately 30%). C. thermocellum achieved total solubilization 33% higher than that of SSCF for the earliest harvest date and 50% higher for the latest harvest date. Potential revenue from protein and bioethanol was stable over a range of different harvest dates, with most of the revenue due to ethanol. In a crop rotation with soybean, recovery of the soluble protein from winter rye could increase per hectare protein production by 20 to 35%. Double-cropping winter rye can produce significant biomass for biofuel production and feed protein as coproduct without competing with the main summer crop. During a 24-day harvest window, the total carbohydrate content remained

Winter atmospheric circulation signature for the timing of the spring bloom of diatoms in the North Sea

Science.gov (United States)

Lohmann, Gerrit; Wiltshire, Karen

2015-04-01

Analysing long-term diatom data from the German Bight and observational climate data for the period 1962-2005, we found a close connection of the inter-annual variation of the timing of the spring bloom with the boreal winter atmospheric circulation. We examined the fact that high diatom counts of the spring bloom tended to occur later when the atmospheric circulation was characterized by winter blocking over Scandinavia. The associated pattern in the sea level pressure showed a pressure dipole with two centres located over the Azores and Norway and was tilted compared to the North Atlantic Oscillation. The bloom was earlier when the cyclonic circulation over Scandinavia allowed an increased inflow of Atlantic water into the North Sea which is associated with clearer, more marine water, and warmer conditions. The bloom was later when a more continental atmospheric flow from the east was detected. At Helgoland Roads, it seems that under turbid water conditions (= low light) zooplankton grazing can affect the timing of the phytoplankton bloom negatively. Warmer water temperatures will facilitate this. Under clear water conditions, light will be the main governing factor with regard to the timing of the spring bloom. These different water conditions are shown here to be mainly related to large-scale weather patterns. We found that the mean diatom bloom could be predicted from the sea level pressure one to three months in advance. Using historical pressure data, we derived a proxy for the timing of the spring bloom over the last centuries, showing an increased number of late (proxy-) blooms during the eighteenth century when the climate was considerably colder than today. We argue that these variations are important for the interpretation of inter-annual to centennial variations of biological processes. This is of particular interest when considering future scenarios, as well to considerations on past and future effects on the primary production and food webs.

Productivity of Spring Chinook Salmon and Summer Steelhead in the John Day River Basin, 2008 Annual Technical Report.

Energy Technology Data Exchange (ETDEWEB)

Wilson, Wayne H.; Schricker, Jaym' e; Ruzychi, James R. (Oregon Department of Fish and Wildlife)

2009-02-13

The John Day River subbasin supports one of the last remaining intact wild populations of spring Chinook salmon and summer steelhead in the Columbia River Basin. These populations remain depressed relative to historic levels and limited information is available for steelhead life history. Numerous habitat protection and rehabilitation projects have been implemented in the basin to improve salmonid freshwater production and survival. However, these projects often lack effectiveness monitoring. While our monitoring efforts outlined here will not specifically measure the effectiveness of any particular project, they will provide much needed programmatic or watershed (status and trend) information to help evaluate project-specific effectiveness monitoring efforts as well as meet some data needs as index stocks. Our continued monitoring efforts to estimate salmonid smolt abundance, age structure, SAR, smolts/redd, freshwater habitat use, and distribution of critical life states will enable managers to assess the long-term effectiveness of habitat projects and to differentiate freshwater and ocean survival. Because Columbia Basin managers have identified the John Day subbasin spring Chinook population as an index population for assessing the effects of alternative future management actions on salmon stocks in the Columbia Basin (Schaller et al. 1999) we continue our ongoing studies. This project is high priority based on the level of emphasis by the NWPPC Fish and Wildlife Program, Independent Scientific Advisory Board (ISAB), Independent Scientific Review Panel (ISRP), NOAA National Marine Fisheries Service (NMFS), and the Oregon Plan for Salmon and Watersheds (OWEB). Each of these groups have placed priority on monitoring and evaluation to provide the real-time data to guide restoration and adaptive management in the region. The objective is to estimate smolt-to-adult survival rates (SAR) and out-migrant abundance for spring Chinook Oncorhynchus tshawytscha and summer

Rise in prostate-specific antigen in men with untreated low-grade prostate cancer is slower during spring-summer.

Science.gov (United States)

Vieth, R; Choo, R; Deboer, L; Danjoux, C; Morton, G C; Klotz, L

2006-01-01

To test the hypothesis that the rate of rise in prostate-specific antigen (PSA) is slower during the spring-summer than during the rest of the year, we used PSA data from a prospective single-arm cohort study of men who had been followed to characterize a watchful observation protocol with selective delayed intervention for clinically localized, low-to-intermediate grade prostate adenocarcinoma. The rate of PSA increase was calculated as the visit-to-visit slope of log (PSA) against time, from 1 calendar-quarter visit to the next. The nonparametric Friedman test confirmed differences in rate of PSA rise among the calendar quarters (P = 0.041). Post hoc analysis showed the rate of PSA increase during Q2 was significantly slower than in each one of the other calendar quarters (Q1 versus Q2, P = 0.025; Q3 versus Q2, P = 0.002; Q4 versus Q2, P = 0.013), with no differences among quarters Q1, Q3, and Q4. These results are consistent with the vitamin D hypothesis that the higher 25-hydroxyvitamin D levels associated with spring and summer have a desirable effect on prostate biology. The therapeutic implication is that vitamin D supplementation in the range of 2000 IU/d, a dose comparable to the effect of summer, can benefit men monitored for rising PSA.

An analysis of US propane markets, winter 1996-1997

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

In late summer 1996, in response to relatively low inventory levels and tight world oil markets, prices for crude oil, natural gas, and products derived from both began to increase rapidly ahead of the winter heating season. Various government and private sector forecasts indicated the potential for supply shortfalls and sharp price increases, especially in the event of unusually severe winter weather. Following a rapid runup in gasoline prices in the spring of 1996, public concerns were mounting about a possibly similar situation in heating fuels, with potentially more serious consequences. In response to these concerns, the Energy Information Administration (EIA) participated in numerous briefings and meetings with Executive Branch officials, Congressional committee members and staff, State Energy Offices, and consumers. EIA instituted a coordinated series of actions to closely monitor the situation and inform the public. This study constitutes one of those actions: an examination of propane supply, demand, and price developments and trends.

Initial studies of the populations of fungi and bacteria in the soil under the influence of the cuItivation of spring wheat and winter wheat in a growth chamber

OpenAIRE

Danuta Pięta

2013-01-01

The purpose of the studies was to determine the populations of fungi and bacteria after the cultivation of spring wheat and winter wheat. As a result of the studies it was found out that winter wheat had a stimulating effect on the total number of bacteria, especially Pseudomonas spp. On the other hand, spring wheat had a smaller influence on the growth of bacteria, while stimulating the growth of the number of fungi. Among the bacteria and saprophytic fungi isolated from the soil after the c...

Is shade beneficial for mediterranean shrubs experiencing periods of extreme drought and late-winter frosts?

Science.gov (United States)

Valladares, Fernando; Zaragoza-Castells, Joana; Sánchez-Gómez, David; Matesanz, Silvia; Alonso, Beatriz; Portsmuth, Angelika; Delgado, Antonio; Atkin, Owen K

2008-12-01

Plants are naturally exposed to multiple, frequently interactive stress factors, most of which are becoming more severe due to global change. Established plants have been reported to facilitate the establishment of juvenile plants, but net effects of plant-plant interactions are difficult to assess due to complex interactions among environmental factors. An investigation was carried out in order to determine how two dominant evergreen shrubs (Quercus ilex and Arctostaphylos uva-ursi) co-occurring in continental, Mediterranean habitats respond to multiple abiotic stresses and whether the shaded understorey conditions ameliorate the negative effects of drought and winter frosts on the physiology of leaves. Microclimate and ecophysiology of sun and shade plants were studied at a continental plateau in central Spain during 2004-2005, with 2005 being one of the driest and hottest years on record; several late-winter frosts also occurred in 2005. Daytime air temperature and vapour pressure deficit were lower in the shade than in the sun, but soil moisture was also lower in the shade during the spring and summer of 2005, and night-time temperatures were higher in the shade. Water potential, photochemical efficiency, light-saturated photosynthesis, stomatal conductance and leaf 13C composition differed between sun and shade individuals throughout the seasons, but differences were species specific. Shade was beneficial for leaf-level physiology in Q. ilex during winter, detrimental during spring for both species, and of little consequence in summer. The results suggest that beneficial effects of shade can be eclipsed by reduced soil moisture during dry years, which are expected to be more frequent in the most likely climate change scenarios for the Mediterranean region.

The thermal comfort and its changes in the 31 provincial capital cities of mainland China in the past 30 years

Science.gov (United States)

Chi, Xiaoli; Li, Rui; Cubasch, Ulrich; Cao, Wenting

2018-04-01

The thermal comfort and its changes in the 31 provincial capital cities of mainland China in the past 30 years were comprehensively evaluated using the Physiologically Equivalent Temperature (PET) and Universal Thermal Climate Index (UTCI) indicators. The PET and UTCI values were highly correlated with each other and presented similar thermal comfort pattern, although their sensitivities might differ slightly. The results showed that these cities covered, respectively, 4-8 and 6-8 thermal comfort classes of the PET and UTCI scale. On the whole, the annual cumulative number of pleasant days was more than 160 days/year. In terms of seasonal variations in thermal comfort conditions, the 31 provincial capital cities in mainland China can be classified into 5 types, which are, respectively, characterized by pleasant summer and severe cold winter (type-I); pleasant spring, autumn, winter, and severe hot summer (type-II); pleasant spring and autumn, slightly pleasant summer, and cold winter (type-III); pleasant spring and autumn, hot stress summer, and slightly cold winter (type-IV); and pleasant spring, summer, autumn, and cool winter (type-V). Type-II cities are rare winter resorts, while type-I cities are natural summer resorts. Type-V cities are the year round pleasant resorts. In the past three decades, the cities in mainland China had experienced increasing pleasant duration in late winter and early spring and intensifying heat stress in summer. The reduction in annual cumulative number of cold stress days in higher latitude/altitude cities outweighed the increase in duration of heat stress in subtropical cities. These may provide some references for urban planning and administration in mainland China.

Fall and winter microhabitat use and suitability for spring chinook salmon parr in a U.S. Pacific Northwest River

Science.gov (United States)

Favrot, Scott D.; Jonasson, Brian C.; Peterson, James T.

2018-01-01

Habitat degradation has been implicated as a primary threat to Pacific salmon Oncorhynchus spp. Habitat restoration and conservation are key toward stemming population declines; however, winter microhabitat use and suitability knowledge are lacking for small juvenile salmonids. Our objective was to characterize microhabitat use and suitability for spring Chinook Salmon Oncorhynchus tshawytscha parr during fall and winter. Using radiotelemetry techniques during October–February (2009–2011), we identified fall and winter microhabitat use by spring Chinook Salmon parr in Catherine Creek, northeastern Oregon. Tagged fish occupied two distinct gradient reaches (moderate and low). Using a mixed‐effects logistic regression resource selection function (RSF) model, we found evidence that microhabitat use was similar between free‐flowing and surface ice conditions. However, habitat use shifted between seasons; most notably, there was greater use of silt substrate and areas farther from the bank during winter. Between gradients, microhabitat use differed with greater use of large wood (LW) and submerged aquatic vegetation in the low‐gradient reach. Using a Bayesian RSF approach, we developed gradient‐specific habitat suitability criteria. Throughout the study area, deep depths and slow currents were most suitable, with the exception of the low‐gradient reach where moderate depths were optimal. Near‐cover coarse and fine substrates were most suitable in the moderate‐ and low‐gradient reaches, respectively. Near‐bank LW was most suitable throughout the study area. Multivariate principal component analyses (PCA) indicated co‐occurring deep depths supporting slow currents near cover were intensively occupied in the moderate‐gradient reach. In the low‐gradient reach, PCA indicated co‐occurring moderate depths, slow currents, and near‐bank cover were most frequently occupied. Our study identified suitable and interrelated microhabitat

Wind erosion potential of a winter wheat-summer fallow rotation after land application of biosolids

Science.gov (United States)

Pi, Huawei; Sharratt, Brenton; Schillinger, William F.; Bary, Andrew I.; Cogger, Craig G.

2018-06-01

Conservation tillage is a viable management strategy to control soil wind erosion, but other strategies such as land application of biosolids that enhance soil quality may also reduce wind erosion. No studies have determined the effects of biosolids on wind erosion. Wind erosion potential of a silt loam was assessed using a portable wind tunnel after applying synthetic and biosolids fertilizer to traditional (disk) and conservation (undercutter) tillage practices during the summer fallow phase of a winter wheat-summer fallow (WW-SF) rotation in 2015 and 2016 in east-central Washington. Soil loss ranged from 12 to 61% lower for undercutter than disk tillage, possibly due to retention of more biomass on the soil surface of the undercutter versus disk tillage treatment. In contrast, soil loss was similar to or lower for biosolids as compared with synthetic fertilizer treatment. Our results suggest that biosolids applications to agricultural lands will have minimal impact on wind erosion.

Winter warming as an important co-driver for Betula nana growth in western Greenland during the past century.

Science.gov (United States)

Hollesen, Jørgen; Buchwal, Agata; Rachlewicz, Grzegorz; Hansen, Birger U; Hansen, Marc O; Stecher, Ole; Elberling, Bo

2015-06-01

Growing season conditions are widely recognized as the main driver for tundra shrub radial growth, but the effects of winter warming and snow remain an open question. Here, we present a more than 100 years long Betula nana ring-width chronology from Disko Island in western Greenland that demonstrates a highly significant and positive growth response to both summer and winter air temperatures during the past century. The importance of winter temperatures for Betula nana growth is especially pronounced during the periods from 1910-1930 to 1990-2011 that were dominated by significant winter warming. To explain the strong winter importance on growth, we assessed the importance of different environmental factors using site-specific measurements from 1991 to 2011 of soil temperatures, sea ice coverage, precipitation and snow depths. The results show a strong positive growth response to the amount of thawing and growing degree-days as well as to winter and spring soil temperatures. In addition to these direct effects, a strong negative growth response to sea ice extent was identified, indicating a possible link between local sea ice conditions, local climate variations and Betula nana growth rates. Data also reveal a clear shift within the last 20 years from a period with thick snow depths (1991-1996) and a positive effect on Betula nana radial growth, to a period (1997-2011) with generally very shallow snow depths and no significant growth response towards snow. During this period, winter and spring soil temperatures have increased significantly suggesting that the most recent increase in Betula nana radial growth is primarily triggered by warmer winter and spring air temperatures causing earlier snowmelt that allows the soils to drain and warm quicker. The presented results may help to explain the recently observed 'greening of the Arctic' which may further accelerate in future years due to both direct and indirect effects of winter warming. © 2015 John Wiley & Sons

Role of Acclimatization in Weather-Related Human Mortality During the Transition Seasons of Autumn and Spring in a Thermally Extreme Mid-Latitude Continental Climate

Science.gov (United States)

de Freitas, Christopher R.; Grigorieva, Elena A.

2015-01-01

Human mortality is closely related to natural climate-determined levels of thermal environmental stress and the resulting thermophysiological strain. Most climate-mortality research has focused on seasonal extremes during winter and summer when mortality is the highest, while relatively little attention has been paid to mortality during the transitional seasons of autumn and spring. The body acclimatizes to heat in the summer and cold in winter and readjusts through acclimatization during the transitions between the two during which time the body experiences the thermophysiological strain of readjustment. To better understand the influences of weather on mortality through the acclimatization process, the aim here is to examine the periods that link very cold and very warms seasons. The study uses the Acclimatization Thermal Strain Index (ATSI), which is a comparative measure of short-term thermophysiological impact on the body. ATSI centers on heat exchange with the body’s core via the respiratory system, which cannot be protected. The analysis is based on data for a major city in the climatic region of the Russian Far East characterized by very hot summers and extremely cold winters. The results show that although mortality peaks in winter (January) and is at its lowest in summer (August), there is not a smooth rise through autumn nor a smooth decline through spring. A secondary peak occurs in autumn (October) with a smaller jump in May. This suggests the acclimatization from warm-to-cold produces more thermophysiological strain than the transition from cold-to-warm. The study shows that ATSI is a useful metric for quantifying the extent to which biophysical adaptation plays a role in increased strain on the body during re-acclimatization and for this reason is a more appropriate climatic indictor than air temperature alone. The work gives useful bioclimatic information on risks involved in transitional seasons in regions characterized by climatic extremes. This

Reproductive success and failure: the role of winter body mass in reproductive allocation in Norwegian moose.

Science.gov (United States)

Milner, Jos M; van Beest, Floris M; Solberg, Erling J; Storaas, Torstein

2013-08-01

A life history strategy that favours somatic growth over reproduction is well known for long-lived iteroparous species, especially in unpredictable environments. Risk-sensitive female reproductive allocation can be achieved by a reduced reproductive effort at conception, or the subsequent adjustment of investment during gestation or lactation in response to unexpected environmental conditions or resource availability. We investigated the relative importance of reduced investment at conception compared with later in the reproductive cycle (i.e. prenatal, perinatal or neonatal mortality) in explaining reproductive failure in two high-density moose (Alces alces) populations in southern Norway. We followed 65 multiparous, global positioning system (GPS)-collared females throughout the reproductive cycle and focused on the role of maternal nutrition during gestation in determining reproductive success using a quasi-experimental approach to manipulate winter forage availability. Pregnancy rates in early winter were normal (≥0.8) in all years while spring calving rates ranged from 0.4 to 0.83, with prenatal mortality accounting for most of the difference. Further losses over summer reduced autumn recruitment rates to 0.23-0.69, despite negligible predation. Over-winter mass loss explained variation in both spring calving and autumn recruitment success better than absolute body mass in early or late winter. Although pregnancy was related to body mass in early winter, overall reproductive success was unrelated to pre-winter body condition. We therefore concluded that reproductive success was limited by winter nutritional conditions. However, we could not determine whether the observed reproductive allocation adjustment was a bet-hedging strategy to maximise reproduction without compromising survival or whether females were simply unable to invest more resources in their offspring.

Microclimate without shade and silvopastoral system during summer and winter - doi: 10.4025/actascianimsci.v35i1.15155 Microclimate without shade and silvopastoral system during summer and winter - doi: 10.4025/actascianimsci.v35i1.15155

Directory of Open Access Journals (Sweden)

Alexandre Krutzman

2013-01-01

Full Text Available This study evaluated the microclimate in a system without shade (WS and in a silvopastoral system (SP with eucalyptus during summer and winter, by measuring the air temperature (Ta, black globe temperature (Tg, relative humidity (RH, wind speed (Ws, every 2 hours for 24 hours between rows, shade (SP and no shade effect (WS. It was employed the randomized blocks design (months, in the plots (systems, subplots (hours and sub-subplots (seasons. Except for Ta and RH, the Tg (24.73, 26.41ºC, Ws (3.16, 4.57 m s-1, Black globe-humidity index (BGHI (71.83, 73.84, Thermal load index (TLI (74.53, 76.11 and Radiant thermal load (RTL (526.46, 595.80 W m-2, respectively for SP and WS, were higher in WS. Ta, RH and Ws had a quadratic effect of hour. There was an effect of season, respectively in summer and winter, on the Ta (27.55, 14.93°C, RH (72.11, 60.68%, Tg (29.80, 21.33°C, BGHI (80.04, 65.63, TLI (81.64, 69.00 and RTL (575.65, 546.61 W m-2. Tg, RH and RTL showed an interaction of season x hour, and a quadratic effect, and the RTL had an interaction of system x season. The Tg was correlated with BGHI (0.962, TLI (0.956 and RTL (0.809. The silvopastoral system decreased the Tg and Ws, and made the environment more harmonious by decreasing the climatic differences between seasons.  This study evaluated the microclimate in a system without shade (WS and in a silvopastoral system (SP with eucalyptus during summer and winter, by measuring the air temperature (Ta, black globe temperature (Tg, relative humidity (RH, wind speed (Ws, every 2 hours for 24 hours between rows, shade (SP and no shade effect (WS. It was employed the randomized blocks design (months, in the plots (systems, subplots (hours and sub-subplots (seasons. Except for Ta and RH, the Tg (24.73, 26.41ºC, Ws (3.16, 4.57 m s-1, Black globe-humidity index (BGHI (71.83, 73.84, Thermal load index (TLI (74.53, 76.11 and Radiant thermal load (RTL (526.46, 595.80 W m-2, respectively for SP and WS

Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species

Science.gov (United States)

Firkus, Tyler; Rahel, Frank J.; Bergman, Harold L.; Cherrington, Brian D.

2018-02-01

We examined the spawning success of Fathead Minnows ( Pimephales promelas) and Johnny Darters ( Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

Climate change and Greenland White-fronted Geese Anser albifrons flavirostris: shifts in distribution and advancement in spring departure times at Wexford versus elsewhere in the winter range

DEFF Research Database (Denmark)

Fox, Anthony David; Merne, Oscar J; Walsh, Alyn J.

2012-01-01

Count data have shown that numbers of Greenland White-fronted Geese Anser albifrons flavirostris wintering at their numerically most important site (Wexford Slobs in south east Ireland) have remained more or less constant over 30 years, in contrast to recent declines at their second most important...... site (Islay further north in south west Scotland), and declines in the population as a whole. There was no evidence to suggest a northwards shift in wintering geese as might be predicted under global climate change. Although Greenland White-fronted Geese now depart from Wexford in spring on average 22...... in migration timing. The more rapid advancement of spring migration at Wexford compared to elsewhere in the range and the retention of wintering geese there in contrast to declining trends amongst the population as a whole suggest that local management of the food resource at Wexford may be responsible...

Effect of Different Parts (Leaf, Stem and Stalk) and Seasons (Summer and Winter) on the Chemical Compositions and Antioxidant Activity of Moringa oleifera

Science.gov (United States)

Shih, Ming-Chih; Chang, Cheng-Ming; Kang, Sue-Ming; Tsai, Min-Lang

2011-01-01

Moringa oleifera, Lam. (Moringaceae) is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part), calcium and phenolic compounds (except the leaf part) and stronger antioxidative activity than summer samples. The methanolic extract of Moringa showed strong scavenging effect of DPPH radicals and reducing power. The trend of antioxidative activity as a function of the part of Moringa was: leaf > stem > stalk for samples from both seasons investigated. The Moringa extract showed strong hydrogen peroxide scavenging activity and high Superoxide Dismutase (SOD) activity except the stalk part. PMID:22016645

Decadal variability in snow depth anomaly over Eurasia and its association with all India summer monsoon rainfall and seasonal circulations

International Nuclear Information System (INIS)

Singh, G.P.

2003-05-01

The Historical Soviet Daily Snow Depth (HSDSD) version II data set has been used in the computation of winter and spring snow depth anomalies over west (25 deg. E to 70 deg. E, 35 deg. N to 65 deg. N) and east (70 deg. E to 160 deg. E, 35 deg. N to 65 deg. N) Eurasia. It is noticed that winter snow depth anomaly over east Eurasia is positively correlated while west Eurasia is negatively correlated with subsequent Indian summer monsoon rainfall (ISMR). The DJF snow depth anomaly shows highest and inverse correlation coefficient (CC) with ISMR over a large area of west Eurasia in a recent period of study i.e. 1975-1995. On the basis of standardised winter (mean of December, January and February) snow depth anomaly over west Eurasia, the years 1966, 1968, 1979 and 1986 are identified as high snow years and the years 1961 and 1975 as low snow years. The characteristics of seasonal monsoon circulation features have been studied in detail during contrasting years of less (more) snow depth in winter/spring seasons followed by excess (deficient) rainfall over India using National Center for Environmental Prediction (NCEP) / National Center for Atmospheric Research (NCAR) reanylised data for the period 1948-1995. The composite difference of temperature, wind, stream function and velocity potential during the years of high and low snow years at upper and lower levels have been studied in detail. The temperature at lower level shows maximum cooling up to 6 deg. C during DJF and this cooling persists up to 500hPa by 2 deg. C which gives rise to anomalous cyclonic circulation over the Caspian Sea and this may be one of the causes of the weakening of the summer monsoon circulation over Indian sub-continent. The stream function difference fields show westerly dominated over Arabian Sea at upper level in weak monsoon years. Velocity potential difference field shows complete phase reversal in the dipole structure from the deficient to excess Indian summer monsoon rainfall. (author)

Escapement and Productivity of Spring Chinook Salmon and Summer Steelhead in the John Day River Basin, 2005-2006 Annual Technical Report.

Energy Technology Data Exchange (ETDEWEB)

Schultz, Terra Lang; Wilson, Wayne H.; Ruzycki, James R. [Oregon Department of Fish and Wildlife

2009-04-10

The objectives are: (1) Estimate number and distribution of spring Chinook salmon Oncorhynchus tshawytscha redds and spawners in the John Day River subbasin; and (2) Estimate smolt-to-adult survival rates (SAR) and out-migrant abundance for spring Chinook and summer steelhead O. mykiss and life history characteristics of summer steelhead. The John Day River subbasin supports one of the last remaining intact wild populations of spring Chinook salmon and summer steelhead in the Columbia River Basin. These populations, however, remain depressed relative to historic levels. Between the completion of the life history and natural escapement study in 1984 and the start of this project in 1998, spring Chinook spawning surveys did not provide adequate information to assess age structure, progeny-to-parent production values, smolt-to-adult survival (SAR), or natural spawning escapement. Further, only very limited information is available for steelhead life history, escapement, and productivity measures in the John Day subbasin. Numerous habitat protection and rehabilitation projects to improve salmonid freshwater production and survival have also been implemented in the basin and are in need of effectiveness monitoring. While our monitoring efforts outlined here will not specifically measure the effectiveness of any particular project, they will provide much needed background information for developing context for project-specific effectiveness monitoring efforts. To meet the data needs as index stocks, to assess the long-term effectiveness of habitat projects, and to differentiate freshwater and ocean survival, sufficient annual estimates of spawner escapement, age structure, SAR, egg-to-smolt survival, smolt-per-redd ratio, and freshwater habitat use are essential. We have begun to meet this need through spawning ground surveys initiated for spring Chinook salmon in 1998 and smolt PIT-tagging efforts initiated in 1999. Additional sampling and analyses to meet these goals

Impact of data assimilation of physical variables on the spring bloom from TOPAZ operational runs in the North Atlantic

Directory of Open Access Journals (Sweden)

A. Samuelsen

2009-12-01

Full Text Available A reanalysis of the North Atlantic spring bloom in 2007 was produced using the real-time analysis from the TOPAZ North Atlantic and Arctic forecasting system. The TOPAZ system uses a hybrid coordinate general circulation ocean model and assimilates physical observations: sea surface anomalies, sea surface temperatures, and sea-ice concentrations using the Ensemble Kalman Filter. This ocean model was coupled to an ecosystem model, NORWECOM (Norwegian Ecological Model System, and the TOPAZ-NORWECOM coupled model was run throughout the spring and summer of 2007. The ecosystem model was run online, restarting from analyzed physical fields (result after data assimilation every 7 days. Biological variables were not assimilated in the model. The main purpose of the study was to investigate the impact of physical data assimilation on the ecosystem model. This was determined by comparing the results to those from a model without assimilation of physical data. The regions of focus are the North Atlantic and the Arctic Ocean. Assimilation of physical variables does not affect the results from the ecosystem model significantly. The differences between the weekly mean values of chlorophyll are normally within 5–10% during the summer months, and the maximum difference of ~20% occurs in the Arctic, also during summer. Special attention was paid to the nutrient input from the North Atlantic to the Nordic Seas and the impact of ice-assimilation on the ecosystem. The ice-assimilation increased the phytoplankton concentration: because there was less ice in the assimilation run, this increased both the mixing of nutrients during winter and the area where production could occur during summer. The forecast was also compared to remotely sensed chlorophyll, climatological nutrients, and in-situ data. The results show that the model reproduces a realistic annual cycle, but the chlorophyll concentrations tend to be between 0.1 and 1.0 mg chla/m³ too

Experimental log hauling through a traditional caribou wintering area

Directory of Open Access Journals (Sweden)

Harold G. Cumming

1998-03-01

Full Text Available A 3-year field experiment (fall 1990-spring 1993 showed that woodland caribou (Rangifer tarandus caribou altered their dispersion when logs were hauled through their traditional wintering area. Unlike observations in control years 1 and 3, radio-collared caribou that had returned to the study area before the road was plowed on January 6 of the experimental year 2, moved away 8-60 km after logging activities began. Seasonal migration to Lake Nipigon islands usually peaked in April, but by February 22 of year 2, 4 of the 6 had returned. The islands provide summer refuge from predation, but not when the lake is frozen. Tracks in snow showed that some caribou remained but changed locations. They used areas near the road preferentially in year 1, early year 2, and year 3, but moved away 2-5 km after the road was plowed in year 2. In a nearby undisturbed control area, no such changes occurred. Caribou and moose partitioned habitat on a small scale; tracks showed gray wolf (Canis lupus remote from caribou but close to moose tracks. No predation on caribou was observed within the wintering area; 2 kills were found outside it. Due to the possibility of displacing caribou from winter refugia to places with higher predation risk, log hauling through important caribou winter habitat should be minimized.

Hepatozoon canis infection in ticks during spring and summer in Italy.

Science.gov (United States)

Dantas-Torres, Filipe; Latrofa, Maria Stefania; Weigl, Stefania; Tarallo, Viviana Domenica; Lia, Riccardo Paolo; Otranto, Domenico

2012-02-01

Hepatozoon canis is a common protozoan of dogs, being among the most prevalent tick-borne pathogens infecting dogs around the world. It is primarily transmitted by Rhipicephalus sanguineus, the brown dog tick. In this study we tested ticks collected from dogs and from the environment in order to track the origin of an outbreak of H. canis infection detected in October 2009 in a private dog shelter in southern Italy. Ticks from dogs (n = 267) were collected during the spring of 2009, whereas ticks from environment (n = 300) were found on sticky traps placed in the same shelter during the summer of 2009. All ticks were tested by PCR for the detection of a H. canis 18S ribosomal RNA gene fragment. Four (1.5%, one female and three males) ticks collected from dogs were PCR positive. None of the larvae collected from the environment were positive, but a relatively high infection rate (8.0%) was detected in nymphs. These findings point out that dogs became infected during the summer, when ticks were abundant and highly infected by H. canis. Moreover, this study suggests that castor oil sticky traps might be useful to collect engorged immature ticks in highly infested environments (e.g., dog shelters). This might be particularly interesting to evaluate the level of infection by certain pathogens in free-ranging ticks R. sanguineus, as done in the present study.

Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species.

Science.gov (United States)

Firkus, Tyler; Rahel, Frank J; Bergman, Harold L; Cherrington, Brian D

2018-02-01

We examined the spawning success of Fathead Minnows (Pimephales promelas) and Johnny Darters (Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

Chemical ozone losses in Arctic and Antarctic polar winter/spring season derived from SCIAMACHY limb measurements 2002–2009

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T. Sonkaew

2013-02-01

Full Text Available Stratospheric ozone profiles are retrieved for the period 2002–2009 from SCIAMACHY measurements of limb-scattered solar radiation in the Hartley and Chappuis absorption bands of ozone. This data set is used to determine the chemical ozone losses in both the Arctic and Antarctic polar vortices by averaging the ozone in the vortex at a given potential temperature. The chemical ozone losses at isentropic levels between 450 K and 600 K are derived from the difference between observed ozone abundances and the ozone modelled taking diabatic cooling into account, but no chemical ozone loss. Chemical ozone losses of up to 30–40% between mid-January and the end of March inside the Arctic polar vortex are reported. Strong inter-annual variability of the Arctic ozone loss is observed, with the cold winters 2004/2005 and 2006/2007 showing chemical ozone losses inside the polar vortex at 475 K, where 1.7 ppmv and 1.4 ppmv of ozone were removed, respectively, over the period from 22 January to beginning of April and 0.9 ppmv and 1.2 ppmv, respectively, during February. For the winters of 2007/2008 and 2002/2003, ozone losses of about 0.8 ppmv and 0.4 ppmv, respectively are estimated at the 475 K isentropic level for the period from 22 January to beginning of April. Essentially no ozone losses were diagnosed for the relatively warm winters of 2003/2004 and 2005/2006. The maximum ozone loss in the SCIAMACHY data set was found in 2007 at the 600 K level and amounted to about 2.1 ppmv for the period between 22 January and the end of April. Enhanced losses close to this altitude were found in all investigated Arctic springs, in contrast to Antarctic spring. The inter-annual variability of ozone losses and PSC occurrence rates observed during Arctic spring is consistent with the known QBO effects on the Arctic polar vortex, with exception of the unusual Arctic winter 2008/2009.

The maximum total ozone mass loss of about 25 million tons was found in the

Demographic consequences of increased winter births in a large aseasonally breeding mammal (Bos taurus) in response to climate change.

Science.gov (United States)

Burthe, Sarah; Butler, Adam; Searle, Kate R; Hall, Stephen J G; Thackeray, Stephen J; Wanless, Sarah

2011-11-01

1. Studies examining changes in the scheduling of breeding in response to climate change have focused on species with well-defined breeding seasons. Species exhibiting year-round breeding have received little attention and the magnitudes of any responses are unknown. 2. We investigated phenological data for an enclosed feral population of cattle (Bos taurus L.) in northern England exhibiting year-round breeding. This population is relatively free of human interference. 3. We assessed whether the timing of births had changed over the last 60 years, in response to increasing winter and spring temperatures, changes in herd density, and a regime of lime fertilisation. 4. Median birth date became earlier by 1·0 days per year. Analyses of the seasonal distribution of calving dates showed that significantly fewer calves were born in summer (decline from 44% of total births to 20%) and significantly more in winter (increase from 12% to 30%) over the study period. The most pronounced changes occurred in winter, with significant increases in both the proportion and number of births. Winter births arise from conceptions in the previous spring, and we considered models that investigated climate and weather variables associated with the winter preceding and the spring of conceptions. 5. The proportion of winter births was higher when the onset of the plant growing season was earlier during the spring of conceptions. This relationship was much weaker during years when the site had been fertilised with lime, suggesting that increased forage biomass was over-riding the impacts of changing plant phenology. When the onset of the growing season was late, winter births increased with female density. 6. Recruitment estimates from a stage-structured state-space population model were significantly negatively correlated with the proportion of births in the preceding winter, suggesting that calves born in winter are less likely to survive than those born in other seasons. 7.�

The incredible shrinking dewlap: signal size, skin elasticity, and mechanical design in the green anole lizard (Anolis carolinensis).

Science.gov (United States)

Lailvaux, Simon P; Leifer, Jack; Kircher, Bonnie K; Johnson, Michele A

2015-10-01

The expression of male secondary sexual traits can be dynamic, changing size, shape, color, or structure over the course of different seasons. However, the factors underlying such changes are poorly understood. In male Anolis carolinensis lizards, a morphological secondary sexual signal called the dewlap changes size seasonally within individuals. Here, we test the hypothesis that seasonal changes in male dewlap size are driven by increased use and extension of the dewlap in spring and summer, when males are breeding, relative to the winter and fall. We captured male green anole lizards prior to the onset of breeding and constrained the dewlap in half of them such that it could not be extended. We then measured dewlap area in the spring, summer, and winter, and dewlap skin and belly skin elasticity in summer and winter. Dewlaps in unconstrained males increase in area from spring to summer and then shrink in the winter, whereas the dewlaps of constrained males consistently shrink from spring to winter. Dewlap skin is significantly more elastic than belly skin, and skin overall is more elastic in the summer relative to winter. These results show that seasonal changes in dewlap size are a function of skin elasticity and display frequency, and suggest that the mechanical properties of signaling structures can have important implications for signal evolution and design.

Changes in evapotranspiration of summer and winter crops of netted melon [Cucumis melo] grown under glass in relation to meteorological and plant-related factors

International Nuclear Information System (INIS)

Asakura, T.

1998-01-01

Measurements of evapotranspiration taken in the summer and winter on netted melon crops grown under glass were taken to characterize seasonal and daily changes. The data were compared to meteorological and plant-related factors to seek some relationships. Evapotranspiration followed a sigmoid curve until one week after pollination, and then decreased gradually during fruit growth. Cumulative evapotranspirations after transplanting were about 116 kg and 60 kg, respectively, for the summer and winter crops, whereas the peak evapotranspirations were 3.O kg plant(-1) day(-1) and 1.3 kg plant(-1) day(-1). The rapid increase h the evapotranspiration during the early stage was associated with the increase in leaf area; its gradual decrease during fruit growth was associated with a decrease in the transpiration potential of leaves. Therefore, irrigation amounts should be increased with leaf development and decreased with fruit growth. The curve of solar radiation in sunny summer days peaked at noon, whereas vapor pressure deficit usually peaked in early or mid afternoon; evapotranspirations in the afternoon had higher values than had those in the morning. In winter, vapor pressure deficit was relatively high during late afternoon and early morning because of heating, whereas it was low during the remainder of the day on account of low ventilation. These fluctuations led to a weak correlation between evapotranspiration and vapor pressure deficit. Regression analyses indicated that solar radiation was a main meteorological factor affecting evapotranspiration

Patterns of North African dust transport over the Atlantic: winter vs. summer, based on CALIPSO first year data

OpenAIRE

Y. Ben-Ami; I. Koren; O. Altaratz

2009-01-01

One of the most important factors that determine the transported dust effect on the atmosphere is its vertical distribution. In this study the vertical structure of North African dust and stratiform low clouds is analyzed over the Atlantic Ocean for the 2006–2007 boreal winter (December–February) and boreal summer of 2006 (June–August). By using the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) backscatter measurements over the dust routes, we describe the differ...

Fish research project -- Oregon: Investigations into the early life history of naturally produced spring chinook salmon in the Grande Ronde River Basin. Annual progress report, 1 September 1995--31 August 1996

International Nuclear Information System (INIS)

Jonasson, B.C.; Carmichael, R.W.; Keefe, M.

1997-09-01

Historically, the Grande Ronde River produced an abundance of salmonids including stocks of spring, summer and fall chinook salmon, sockeye salmon, coho salmon, and summer steelhead. During the past century, numerous factors have caused the reduction of salmon stocks such that only sustainable stocks of spring chinook salmon and summer steelhead remain. The sizes of spring chinook salmon populations in the Grande Ronde River basin also have been declining steadily and are substantially depressed from estimates of historic levels. In addition to a decline in population abundance, a reduction of spring chinook salmon spawning distribution is evident in the Grande Ronde River basin. Numerous factors are thought to contribute to the decline of spring chinook salmon in the Snake River and its tributaries. These factors include passage problems and increased mortality of juvenile and adult migrants at mainstem Columbia and Snake river dams, overharvest, and habitat degradation associated with timber, agricultural, and land development practices. This study was designed to describe aspects of the life history strategies exhibited by spring chinook salmon in the Grande Ronde River basin. During the past year the focus was on rearing and migration patterns of juveniles in the upper Grande Ronde River and Catherine Creek. The study design included three objectives: (1) document the annual in-basin migration patterns for spring chinook salmon juveniles in the upper Grande Ronde River and Catherine Creek, including the abundance of migrants, migration timing and duration; (2) estimate and compare smolt survival indices to mainstem Columbia and Snake river dams for fall and spring migrating spring chinook salmon; and (3) determine summer and winter habitat utilization and preference of juvenile spring chinook salmon in the upper Grande Ronde River and Catherine Creek

Effects of tillage on the activity density and biological diversity of carabid beetles in spring and winter crops.

Science.gov (United States)

Hatten, Timothy D; Bosque-Pérez, Nilsa A; Labonte, James R; Guy, Stephen O; Eigenbrode, Sanford D

2007-04-01

The effects of tillage regimen (conventional [CT] and no-tillage [NT]) on the activity density and diversity of carabid beetles (Coleoptera: Carabidae) was studied by pitfall trapping within a rain-fed cropping system in northwestern Idaho, 2000-2002. The cropping rotation consisted of a spring cereal (barley, Hordeum vulgare L., in 2000 and 2001; and wheat, Triticum aestivum L., in 2002), spring dry pea (Pisum sativum L.) 2000-2002, and wheat (T. aestivum), spring in 2000 and 2001, and winter in 2002. A total of 14,480 beetles comprised of 30 species was captured, with five numerically dominant species [Poecilus scitulus L., Poecilus lucublandus Say, Microlestes linearis L., Pterostichus melanarius Ill., and Calosoma cancellatum (Eschscholtz)], accounting for 98% of all captures. All species including the dominants responded idiosyncratically to tillage regimen. Adjusting for trapping biases did not significantly change seasonal activity density of Poecilus spp. or Pt. melanarius to tillage. More beetles were captured in CT than in NT crops because of the dominance of P. scitulus in CT, whereas species richness and biological diversity were generally higher in NT crops. Observed patterns suggest that direct effects of tillage affected some species, whereas indirect effects related to habitat characteristics affected others. CT may provide habitat preferable to xerophilic spring breeders. A relationship was found between beetle species size and tillage regimen in pea and to a lesser extent across all spring crops, with large species (>14 mm) conserved more commonly in NT, small species (tillage systems.

LANDSAT-8 OPERATIONAL LAND IMAGER CHANGE DETECTION ANALYSIS

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W. Pervez

2017-05-01

Full Text Available This paper investigated the potential utility of Landsat-8 Operational Land Imager (OLI for change detection analysis and mapping application because of its superior technical design to previous Landsat series. The OLI SVM classified data was successfully classified with regard to all six test classes (i.e., bare land, built-up land, mixed trees, bushes, dam water and channel water. OLI support vector machine (SVM classified data for the four seasons (i.e., spring, autumn, winter, and summer was used to change detection results of six cases: (1 winter to spring which resulted reduction in dam water mapping and increases of bushes; (2 winter to summer which resulted reduction in dam water mapping and increase of vegetation; (3 winter to autumn which resulted increase in dam water mapping; (4 spring to summer which resulted reduction of vegetation and shallow water; (5 spring to autumn which resulted decrease of vegetation; and (6 summer to autumn which resulted increase of bushes and vegetation . OLI SVM classified data resulted higher overall accuracy and kappa coefficient and thus found suitable for change detection analysis.

Soil Thermal Balance Analysis for a Ground Source Heat Pump System in a Hot-Summer and Cold-Winter Region

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Zhongchao Zhao

2018-05-01

Full Text Available As a renewable and high energy efficiency technology providing air conditioning and domestic hot water, the ground source heat pump system (GSHPS has been extensively used worldwide in recent years. Compared with conventional systems, GSHPSs with heat recovery reject less heat into the soil and extract more heat from it, which can help reduce soil thermal imbalance in hot-summer and cold-winter regions. In this paper, conventional GSHPS, and GSHPS with different heat recovery ratios, in a typical city were compared based on thermal imbalance ratios, average soil temperatures and soil temperature increases. The transient system simulation software was used to simulate the operation performance of GSHPS. The thermal imbalance ratio and soil temperature decreased with increasing heat recovery ratio. After 20 years of operation, the soil thermal imbalance ratios of the GSHPS were 29.2%, 21.1%, 16%, and 5.2%, and the soil temperature rises were 8.78 °C, 5.25 °C, 3.44 °C, and 0.34 °C, while the heat recovery ratios were 0, 18%, 30% and 53%, respectively. Consequently, a GSHPS with heat recovery is a potentially efficient and economical approach for buildings in hot-summer and cold-winter regions.

Linking meteorological drivers of spring-summer drought regimes to agricultural drought risk in China

Science.gov (United States)

Dai, L.; Wright, J. S.; Yu, C.; Huang, W. Y.

2017-12-01

As a drought prone country, China has experienced frequent severe droughts in recent decades. Drought frequency and severity are projected to increase in China under climate change. An understanding of the physical processes that contribute to extreme droughts is essential for seasonal forecasting, but the dominant physical mechanisms responsible for droughts in most parts of China are still unclear. Moreover, despite numerous studies on droughts in China, there are few clear connections between the meteorological and climatological drivers of extreme droughts and the associated agricultural consequences. This knowledge gap limits the capacity for decision-making support in drought management. The objectives of this study are (1) to identify robust spring-summer drought regimes over China, (2) to investigate the physical mechanisms associated with each regime, and (3) to better clarify connections between meteorological drought regimes and agricultural drought risk. First, we identify six drought regimes over China by applying an area-weighted k-means clustering technique to spatial patterns of spring-summer Standardized Precipitation Index (SPI) obtained from the ten-member ERA-20CM ensemble for 1900-2010. Second, we project these drought regimes onto agricultural drought risk maps for the three major cereal crops (rice, maize, and wheat) in China. Taking into account historical harvest areas for these crops, we then evaluate the potential impact of each drought regime on agricultural production. Third, the physical mechanisms and meteorological context behind each drought regimes are investigated based on monthly outputs from ERA20CM. We analyze the preceding and concurrent atmospheric circulation anomalies associated with each regime, and propose mechanistic explanations for drought development. This work provides a new perspective on diagnosing the physical mechanisms behind seasonal droughts, and lays a foundation for improving seasonal drought prediction and

Coherent climate anomalies over the Indo-western Pacific in post-El Niño summer

Science.gov (United States)

Kosaka, Y.; Xie, S. P.; DU, Y.; Hu, K.; Chowdary, J. S.; Huang, G.

2016-12-01

El Niño typically peaks in boreal winter, and the associated equatorial Pacific sea surface temperature (SST) signal dissipates before subsequent summer. Its impact, however, outlasts until boreal summer in the Indo-western Pacific, featuring basin-wide Indian Ocean warming and tropical Northwestern Pacific cooling accompanied by the Pacific-Japan (PJ) teleconnection pattern with surface anomalous anticyclone (AAC) extending from the Philippine Sea to the northern Indian Ocean. Two formation mechanisms have been proposed for these climate anomalies in post-El Niño-Southern Oscillation (ENSO) summer. One hypothesis invokes the wind-evaporation-SST (WES) feedback in the tropical Northwestern Pacific, while the other points to inter-basin feedback between the Indian Ocean and tropical Northwestern Pacific. Based on a coupled model experiment, we propose an ocean-atmosphere coupled mode that synthesizes the two mechanisms. This Indo-western Pacific Ocean capacitor (IPOC) mode evolves seasonally from spring to summer under seasonal migration of background state. In spring, the WES feedback is operative in association with the tropical Northwestern Pacific cooling, while in summer the Indian Ocean warming and the inter-basin interaction maintains the AAC. While the IPOC mode is independent of ENSO in mechanism, ENSO can drive this mode in its decay phase. This excitation, however, has undergone substantial interdecadal modulations, depending on ENSO amplitude and persistence of Indian Ocean warming. The ENSO-IPOC correlation is high after the mid-1970s and at the beginning of the 20th century, but low in between.

The diet of the South American sea lion (Otaria flavescens at Río Negro, Patagonia, Argentina, during the winter-spring period

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Raimundo L. Bustos

2012-12-01

Full Text Available The South American sea lion, Otaria flavescens (Shaw, 1800 population is steadily expanding along the Patagonian coast of Argentina in the last decades. However, little is known about the feeding ecology of the species in the area. The aim of this study was to analyze the food habits of O. flavescens from 91 scats collected at Río Negro province, during the winter and spring of 2005. Fish occurred in 96% of scats containing prey remains, followed by cephalopods (26%. Raneya brasiliensis (Kaup, 1856 was the most frequent and abundant species occurring in 58.6% of samples and constituting almost 50% of fish predated. Second in importance were Porichthys porosissimus (Cuvier, 1829 and Cynoscion guatucupa (Cuvier, 1830 in terms of occurrence (%FO 20.7 and numbers (29.6% respectively. The squid Loligo gahi (d'Orbigny, 1835 was the most frequent cephalopod prey (42.1%, whereas Octopus tehuelchus (d'Orbigny, 1834 was the most abundant (77%. The higher amount and diversity of prey found in the spring in comparison with the winter season might be related to a higher feeding activity of seals or to a seasonal increase in food availability in the area.

Long-term changes in climatological calendar

International Nuclear Information System (INIS)

Jaagus, J.

1997-01-01

Trends in time series of climatic seasons in Tartu, Estonia, during 1891-1995 are analysed using regression analysis. Two intermediate seasons between autumn and winter (late autumn, early winter), and two ones between winter and spring (late winter and early spring) are determined. The climatic seasons correspond quite well to individual stages of annual cycling of nature. Results of linear regression analysis demonstrate changes in climatological calendar reflecting the influence of global warming. Climatic seasons of spring period have moved to earlier time, and seasons of autumn period to later time. Statistically significant trends were observed for beginning date of early spring (12 days earlier), summer (11 days earlier) and late autumn (8 days later). Beginning date of winter has shifted 12 days later. Duration of summer season has increased by two weeks and duration of winter season has decreased by the same time. (author)

Bread winter wheat breeding (Triticum aestivum L. using spring varieties genepool in forest-steppe Environments of Ukraine

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В. С. Кочмарський

2010-10-01

Full Text Available It is concluded by investigations that wheat crossing of various development types between themselves cause increase of formbuilding process in hybrid progeny, promoting the selection of practically valuable recombinats. The genotypes which present the practical valuable by complex of adaptive traits and properties have been selected by phenotype stability in the breeding process. The new bread winter wheat variety Pamyati Remesla developed with participation of spring wheat variety Hja 22139 (Finland has been proposed for including it into the Register of Plant varieties of Ukraine adapted for use in Steppe, Forest- Steppe and Woodland of Ukraine since 2010.

Seasonal dynamics of saproxylic beetles (Coleoptera occurring in decaying birch (Betula spp. wood in the Kampinos National Park

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Sawoniewicz Michał

2015-09-01

Full Text Available The aim of the study was to identify the seasonal changes in the number of saproxylic beetles connected with birch in the Kampinos National Park. The research was conducted for 12 consecutive months in research areas representing 10 different site types. The beetles were collected from wood using photoeclectors. The largest number of species was collected in April and the lowest in January. An increase in number occurred during spring and summer months for species associated only with rotting wood, fructifications of tree fungi, the subcortical environment and hollows. In the same period the number of species not associated or potentially associated with decaying trees and wood decreased. During winter months, the differences in the number of trapped specimens were the smallest. The proportion of zoophagous species amongst the collected specimen increased in autumn and winter. The share of saprophagous species was the highest during the summer-autumn period and the share of mycetophages (jointly with myxomycophages was the highest during spring and summer. We distinguished two separate groups of Coleoptera with the first one (‘summer group’ including species trapped during late-spring and summer months, while the second one (‘winter group’ includes species found in autumn, winter and early-spring months. In the ‘summer group’, an average of 55.8 species was trapped each month with 331.2 specimen of Coleoptera, while in the ʻwinter group’ an average of 56.1 species with 228.4 Coleoptera specimen were caught.

A trajectory analysis of atmospheric transport of black carbon aerosols to Canadian high Arctic in winter and spring (1990–2005

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L. Huang

2010-06-01

Full Text Available Black carbon (BC particles accumulated in the Arctic troposphere and deposited on snow have been calculated to have significant effects on radiative forcing of the Arctic regional climate. Applying cluster analysis technique on 10-day backward trajectories, seven distinct transport pathways (or clusters affecting Alert (82.5° N, 62.5° W, Nunavut in Canada are identified in this work. Transport frequency associated with each pathway is obtained as the fraction of trajectories in that cluster. Based on atmospheric transport frequency and BC surface flux from surrounding regions (i.e. North America, Europe, and former USSR, a linear regression model is constructed to investigate the inter-annual variations of BC observed at Alert in January and April, representative of winter and spring respectively, between 1990 and 2005. Strong correlations are found between BC concentrations predicted with the regression model and measurements at Alert for both seasons (R² equals 0.77 and 0.81 for winter and spring, respectively. Results imply that atmospheric transport and BC emission are the major contributors to the inter-annual variations in BC concentrations observed at Alert in the cold seasons for the 16-year period. Other factors, such as deposition, could also contribute to the variability in BC concentrations but were not considered in this analysis. Based on the regression model the relative contributions of regional BC emissions affecting Alert are attributed to the Eurasian sector, composed of the European Union and the former USSR, and the North American sector. Considering both seasons, the model suggests that former USSR is the major contributor to the near-surface BC levels at the Canadian high Arctic site with an average contribution of about 67% during the 16-year period, followed by European Union (18% and North America (15%. In winter, the atmospheric transport of BC aerosols from Eurasia is found to be even more

Winter climate limits subantarctic low forest growth and establishment.

Science.gov (United States)

Harsch, Melanie A; McGlone, Matt S; Wilmshurst, Janet M

2014-01-01

Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E) is oceanic (Conrad Index of Continentality  =  -5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

Predictability of two types of El Niño and their climate impacts in boreal spring to summer in coupled models

Science.gov (United States)

Lee, Ray Wai-Ki; Tam, Chi-Yung; Sohn, Soo-Jin; Ahn, Joong-Bae

2017-12-01

The predictability of the two El Niño types and their different impacts on the East Asian climate from boreal spring to summer have been studied, based on coupled general circulation models (CGCM) simulations from the APEC Climate Center (APCC) multi-model ensemble (MME) hindcast experiments. It was found that both the spatial pattern and temporal persistence of canonical (eastern Pacific type) El Niño sea surface temperature (SST) are much better simulated than those for El Niño Modoki (central Pacific type). In particular, most models tend to have El Niño Modoki events that decay too quickly, in comparison to those observed. The ability of these models in distinguishing between the two types of ENSO has also been assessed. Based on the MME average, the two ENSO types become less and less differentiated in the model environment as the forecast leadtime increases. Regarding the climate impact of ENSO, in spring during canonical El Niño, coupled models can reasonably capture the anomalous low-level anticyclone over the western north Pacific (WNP)/Philippine Sea area, as well as rainfall over coastal East Asia. However, most models have difficulties in predicting the springtime dry signal over Indochina to South China Sea (SCS) when El Niño Modoki occurs. This is related to the location of the simulated anomalous anticyclone in this region, which is displaced eastward over SCS relative to the observed. In boreal summer, coupled models still exhibit some skills in predicting the East Asian rainfall during canonical El Nino, but not for El Niño Modoki. Overall, models' performance in spring to summer precipitation forecasts is dictated by their ability in capturing the low-level anticyclonic feature over the WNP/SCS area. The latter in turn is likely to be affected by the realism of the time mean monsoon circulation in models.

Weather In Some Islands

Institute of Scientific and Technical Information of China (English)

王良华

2007-01-01

There are four seasons in a year. When spring comes, the weather is mild(温和的). Summer comes after spring. Summer is the hottest season of the year. Autumn follows summer. It is the best season of the year. Winter is the coldest season of the year. Some islands(岛) have their own particular(特别的) seasons because their weather is very much affected(影响) by the oceans(海洋) around them. In Britain, winter is not very cold and summer is not very hot.

Winter to winter recurrence of atmospheric circulation anomalies over East Asia and its impact on winter surface air temperature anomalies.

Science.gov (United States)

Zhao, Xia; Yang, Guang

2017-01-01

The persistence of atmospheric circulation anomalies over East Asia shows a winter to winter recurrence (WTWR) phenomenon. Seasonal variations in sea level pressure anomalies and surface wind anomalies display significantly different characteristics between WTWR and non-WTWR years. The WTWR years are characterized by the recurrence of both a strong (weak) anomalous Siberian High and an East Asian winter monsoon over two successive winters without persistence through the intervening summer. However, anomalies during the non-WTWR years have the opposite sign between the current and ensuing winters. The WTWR of circulation anomalies contributes to that of surface air temperature anomalies (SATAs), which is useful information for improving seasonal and interannual climate predictions over East Asia and China. In the positive (negative) WTWR years, SATAs are cooler (warmer) over East Asia in two successive winters, but the signs of the SATAs are opposite in the preceding and subsequent winters during the non-WTWR years.

Degradation patterns of natural and synthetic textiles on a soil surface during summer and winter seasons studied using ATR-FTIR spectroscopy

Science.gov (United States)

Ueland, Maiken; Howes, Johanna M.; Forbes, Shari L.; Stuart, Barbara H.

2017-10-01

Textiles are a valuable source of forensic evidence and the nature and condition of textiles collected from a crime scene can assist investigators in determining the nature of the death and aid in the identification of the victim. Until now, much of the knowledge of textile degradation in forensic contexts has been based on the visual inspection of material collected from soil environments. The purpose of the current study was to investigate the potential of a more quantitative approach to the understanding of forensic textile degradation through the application of infrared spectroscopy. Degradation patterns of natural and synthetic textile materials as they were subjected to a natural outdoor environment in Australia were investigated. Cotton, polyester and polyester - cotton blend textiles were placed on a soil surface during the summer and winter seasons and were analysed over periods 1 and 1.5 years, respectively, and examined using attenuated total reflectance (ATR) spectroscopy. Statistical analysis of the spectral data obtained for the cotton material correlated with visual degradation and a difference in the onset of degradation between the summer and winter season was revealed. The synthetic material did not show any signs of degradation either visually or statistically throughout the experimental period and highlighted the importance of material type in terms of preservation. The cotton section from the polyester - cotton blend samples was found to behave in a similar manner to that of the 100% cotton samples, however principal component analysis (PCA) demonstrated that the degradation patterns were less distinct in both the summer and winter trial for the blend samples. These findings indicated that the presence of the synthetic material may have inhibited the degradation of the natural material. The use of statistics to analyse the spectral data obtained for textiles of forensic interest provides a better foundation for the interpretation of the data

Effects of summer and winter harvesting on element phytoextraction efficiency of Salix and Populus clones planted on contaminated soil.

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Kubátová, Pavla; Száková, Jiřina; Břendová, Kateřina; Kroulíková-Vondráčková, Stanislava; Mercl, Filip; Tlustoš, Pavel

2018-04-16

The clones of fast-growing trees (FGTs) were investigated for phytoextraction of soil contaminated with risk elements (REs), especially Cd, Pb, and Zn. As a main experimental factor, the potential effect of biomass harvesting time was assessed. The field experiment with two Salix clones (S1 - (Salix schwerinii × Salix viminalis) × S. viminalis, S2 - S. × smithiana) and two Populus clones (P1 - Populus maximowiczii × Populus nigra, P2 - P. nigra) was established in April 2009. Shoots of all clones were first harvested in February 2012. After two further growing seasons, the first half of the trees was harvested in September 2013 before leaf fall (summer harvest) and the second half in February 2014 (winter harvest). Remediation factors (RFs) for all clones and all REs (except Pb for clone S1) were higher in the summer harvest. The highest annual RFs for Cd and for Zn (1.34 and 0.67%, respectively) were found for clone S2 and were significantly higher than other clones. Although no increased mortality of trees harvested in the summer was detected in the following season, the effect of summer harvesting on the phytoextraction potential of FGTs clones should be investigated in long-term studies.

The boreal winter Madden-Julian Oscillation's influence on summertime precipitation in the greater Caribbean

Science.gov (United States)

Curtis, Scott; Gamble, Douglas W.

2016-07-01

Precipitation totals in the greater Caribbean are known to be affected by interannual variability. In particular, dry conditions in the spring-summer have been physically linked to the positive phase of North Atlantic Oscillation (NAO) in the literature. In this study, it was found through regression analysis that an active Madden-Julian Oscillation (MJO) in winter geographically focused over the Maritime Continent contributes to a positive NAO in March via the generation of Rossby waves in the Northern Hemisphere. Specifically, a negative Pacific-North American pattern develops in the winter and transitions to an Atlantic pattern in spring. The positive NAO is a transient feature of this evolving wave train, but a center of significant positive 200 hPa geopotential heights is entrenched over the southeast U.S. throughout the February to May time period and is manifested as high pressure at the surface. The southern flank of this system increases the speeds of the trade winds and leads to a cooling of the Caribbean sea surface temperatures and, thus, convection suppression and reduced precipitation. Thus, this study advances our understanding of the climate of the greater Caribbean by using climate teleconnections to relate the MJO to rainfall in the region.

Seasonal alterations in park visitation, amenity use, and physical activity--Grand Forks, North Dakota, 2012-2013.

Science.gov (United States)

Roemmich, James N; Johnson, LuAnn

2014-09-11

Park amenities promote visitation and physical activity during summer. Physical activity declines during winter. Identifying park amenities that promote visitation during winter would increase year-round activity. The purpose of this study was to determine how park visitation, amenity choice, and physical activity intensity change across seasons. Physical activity intensity of children and adults was assessed at 16 parks in Grand Forks, North Dakota, during summer and fall of 2012, and winter and spring of 2013. Park visitation was highest in spring and lowest in winter. Amenity use varied by season. Parks with water splash pads were visited more during summer, and playgrounds and open spaces were visited more during spring. Ice rinks were visited most in winter. Physical activity intensity was lowest in summer and highest in winter for each age group. The activity intensity observed for all young age groups ranged from 2.7 to 2.9 metabolic equivalents in summer and greater than 3 metabolic equivalents in all other seasons. Adults' mean activity intensity was greater than 3 metabolic equivalents in winter. Information on park visitation, amenity use, and activity intensity across seasons is valuable; it can be used when designing or redesigning parks in order to promote year-round physical activity. Redesigning parks in cold climates to include ice rinks, sledding hills, cross-country skiing, and indoor areas for physical activity would increase winter visitation and allow the park to serve as a year-round resource for physical activity.

Bio-optical properties of Arctic drift ice and surface waters north of Svalbard from winter to spring

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Kowalczuk, Piotr; Meler, Justyna; Kauko, Hanna M.; Pavlov, Alexey K.; Zabłocka, Monika; Peeken, Ilka; Dybwad, Christine; Castellani, Giulia; Granskog, Mats A.

2017-06-01

We have quantified absorption by CDOM, aCDOM(λ), particulate matter, ap(λ), algal pigments, aph(λ), and detrital material, aNAP(λ), coincident with chlorophyll a in sea ice and surface waters in winter and spring 2015 in the Arctic Ocean north of Svalbard. The aCDOM(λ) was low in contrast to other regions of the Arctic Ocean, while ap(λ) has the largest contribution to absorption variability in sea ice and surface waters. ap(443) was 1.4-2.8 times and 1.3-1.8 times higher than aCDOM(443) in surface water and sea ice, respectively. aph(λ) contributed 90% and 81% to ap(λ), in open leads and under-ice waters column, and much less (53%-74%) in sea ice, respectively. Both aCDOM(λ) and ap(λ) followed closely the vertical distribution of chlorophyll a in sea ice and the water column. We observed a tenfold increase of the chlorophyll a concentration and nearly twofold increase in absorption at 443 nm in sea ice from winter to spring. The aCDOM(λ) dominated the absorption budget in the UV both in sea ice and surface waters. In the visible range, absorption was dominated by aph(λ), which contributed more than 50% and aCDOM(λ), which contributed 43% to total absorption in water column. Detrital absorption contributed significantly (33%) only in surface ice layer. Algae dynamics explained more than 90% variability in ap(λ) and aph(λ) in water column, but less than 70% in the sea ice. This study presents detailed absorption budget that is relevant for modeling of radiative transfer and primary production.

Herbage intake of dairy cows in mixed sequential grazing with breeding ewes as followers.

Science.gov (United States)

Jiménez-Rosales, Juan Daniel; Améndola-Massiotti, Ricardo Daniel; Burgueño-Ferreira, Juan Andrés; Ramírez-Valverde, Rodolfo; Topete-Pelayo, Pedro; Huerta-Bravo, Maximino

2018-03-01

This study aimed to evaluate the hypothesis that mixed sequential grazing of dairy cows and breeding ewes is beneficial. During the seasons of spring-summer 2013 and autumn-winter 2013-2014, 12 (spring-summer) and 16 (autumn-winter) Holstein Friesian cows and 24 gestating (spring-summer) and lactating (autumn-winter) Pelibuey ewes grazed on six (spring-summer) and nine (autumn-winter) paddocks of alfalfa and orchard grass mixed pastures. The treatments "single species cow grazing" (CowG) and "mixed sequential grazing with ewes as followers of cows" (MixG) were evaluated, under a completely randomized design with two replicates per paddock. Herbage mass on offer (HO) and residual herbage mass (RH) were estimated by cutting samples. The estimate of herbage intake (HI) of cows was based on the use of internal and external markers; the apparent HI of ewes was calculated as the difference between HO (RH of cows) and RH. Even though HO was higher in CowG, the HI of cows was higher in MixG during spring-summer and similar in both treatments during autumn-winter, implying that in MixG the effects on the cows HI of higher alfalfa proportion and herbage accumulation rate evolving from lower residual herbage mass in the previous cycle counteracted that of a higher HO in CowG. The HI of ewes was sufficient to enable satisfactory performance as breeding ewes. Thus, the benefits of mixed sequential grazing arose from higher herbage accumulation, positive changes in botanical composition, and the achievement of sheep production without negative effects on the herbage intake of cows.

Activities of the wintering party of the 36th Japanese Antarctic Research Expedition, 1995-1996

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Shigemi Meshida

1997-11-01

Full Text Available The wintering party of the 36th Japanese Antarctic Research Expedition (JARE-36 executed its planned activities at Syowa and Dome Fuji Stations from 1995 to 1996. The wintering party at Syowa Station, consisting of 31 personnel, carried out its observations and logistic work from February 1,1995 to January 31,1996. Routine and some specific observations for studies of upper atmosphere physics, meteorology, solid earth geophysics, biology and medical science were performed without any serious problems for a full year. Continuous observation of the magnetosphere had started using an HF radar system constructed during the austral summer of 1994/95. A seed plant was discovered near Nurume Lake, Langhovde. It was the first report of a seed plant growing in continental Antarctica. An architect took part in the wintering party for the first time and maintained decrepit buildings. Support work for the wintering party at Dome Fuji Station was one of the principal tasks at Syowa Station. A trip to the Dome Fuji Station was carried out to transport supplies and fuel in the austral spring of 1995. The first wintering activities at Dome Fuji Station started from January 29,1995. The wintering party, consisting of 9 personnel, carried out meteorological and glaciological observations together with deep ice core drilling and some construction work. Consequently, ice cores of 600m depth were obtained successfully.

Hydroacoustic Evaluation of Overwintering Summer Steelhead Fallback and Kelt Passage at The Dalles Dam, 2009-2010

Energy Technology Data Exchange (ETDEWEB)

Khan, Fenton; Johnson, Gary E.; Weiland, Mark A.

2010-07-31

This report presents the results of an evaluation of overwintering summer steelhead (Oncorhynchus mykiss) fallback and early out-migrating steelhead kelts downstream passage at The Dalles Dam (TDA) sluiceway and turbines during fall/winter 2009 through early spring 2010. The study was conducted by the Pacific Northwest National Laboratory (PNNL) for the U.S. Army Corps of Engineers, Portland District (USACE). The goal of this study was to characterize adult steelhead spatial and temporal distributions and passage rates at the sluiceway and turbines for fisheries managers and engineers to use in decision-making relative to sluiceway operations. The study was from November 1, 2009 to April 10, 2010. The study was divided into three study periods: Period 1, November 1 - December 15, 2009 for a fall/winter sluiceway and turbine study; Period 2, December 16, 2009 - February 28, 2010 for a turbine only study; Period 3, March 1 - April 10, 2010 for a spring sluiceway and turbine study. Sluiceway operations were scheduled to begin on March 1 for this study; however, because of an oil spill cleanup near the sluice outfall, sluiceway operations were delayed until March 8, 2010, therefore the spring study period did not commence until March 8. The study objectives were to (1) estimate the number and distribution of overwintering summer steelhead fallbacks and kelt-sized acoustic targets passing into the sluiceway and turbines at TDA between November 1 and December 15, 2009 and March 1 and April 10, 2010, and (2) estimate the numbers and distribution of adult steelhead and kelt-sized targets passing into turbine units between December 16, 2009 and February 28, 2010. We obtained fish passage data using fixed-location hydroacoustics. For Period 1, overwintering summer steelhead fallback occurred throughout the 45-day study period. A total of 879 {+-} 165 (95% CI) steelhead targets passed through the powerhouse and sluiceway during November 1 to December 15, 2009. Ninety two

Onset of photosynthesis in spring speeds up monoterpene synthesis and leads to emission bursts.

Science.gov (United States)

Aalto, J; Porcar-Castell, A; Atherton, J; Kolari, P; Pohja, T; Hari, P; Nikinmaa, E; Petäjä, T; Bäck, J

2015-11-01

Emissions of biogenic volatile organic compounds (BVOC) by boreal evergreen trees have strong seasonality, with low emission rates during photosynthetically inactive winter and increasing rates towards summer. Yet, the regulation of this seasonality remains unclear. We measured in situ monoterpene emissions from Scots pine shoots during several spring periods and analysed their dynamics in connection with the spring recovery of photosynthesis. We found high emission peaks caused by enhanced monoterpene synthesis consistently during every spring period (monoterpene emission bursts, MEB). The timing of the MEBs varied relatively little between the spring periods. The timing of the MEBs showed good agreement with the photosynthetic spring recovery, which was studied with simultaneous measurements of chlorophyll fluorescence, CO2 exchange and a simple, temperature history-based proxy for state of photosynthetic acclimation, S. We conclude that the MEBs were related to the early stages of photosynthetic recovery, when the efficiency of photosynthetic carbon reactions is still low whereas the light harvesting machinery actively absorbs light energy. This suggests that the MEBs may serve a protective functional role for the foliage during this critical transitory state and that these high emission peaks may contribute to atmospheric chemistry in the boreal forest in springtime. © 2015 John Wiley & Sons Ltd.

Assessing the ratio of leaf carbon to nitrogen in winter wheat and spring barley based on hyperspectral data

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Xu, Xin-gang; Gu, Xiao-he; Song, Xiao-yu; Xu, Bo; Yu, Hai-yang; Yang, Gui-jun; Feng, Hai-kuan

2016-10-01

The metabolic status of carbon (C) and nitrogen (N) as two essential elements of crop plants has significant influence on the ultimate formation of yield and quality in crop production. The ratio of carbon to nitrogen (C/N) from crop leaves, defined as ratio of LCC (leaf carbon concentration) to LNC (leaf nitrogen concentration), is an important index that can be used to diagnose the balance between carbon and nitrogen, nutrient status, growth vigor and disease resistance in crop plants. Thus, it is very significant for effectively evaluating crop growth in field to monitor changes of leaf C/N quickly and accurately. In this study, some typical indices aimed at N estimation and chlorophyll evaluation were tested to assess leaf C/N in winter wheat and spring barley. The multi-temporal hyperspectral measurements from the flag-leaf, anthesis, filling, and milk-ripe stages were used to extract these selected spectral indices to estimate leaf C/N in wheat and barley. The analyses showed that some tested indices such as MTCI, MCARI/OSAVI2, and R-M had the better performance of assessing C/N for both of crops. Besides, a mathematic algorithm, Branch-and-Bound (BB) method was coupled with the spectral indices to assess leaf C/N in wheat and barley, and yielded the R2 values of 0.795 for winter wheat, R2 of 0.727 for spring barley, 0.788 for both crops combined. It demonstrates that using hyperspectral data has a good potential for remote assessment of leaf C/N in crops.

Winter survival of Scots pine seedlings under different snow conditions.

Science.gov (United States)

Domisch, Timo; Martz, Françoise; Repo, Tapani; Rautio, Pasi

2018-04-01

Future climate scenarios predict increased air temperatures and precipitation, particularly at high latitudes, and especially so during winter. Soil temperatures, however, are more difficult to predict, since they depend strongly on the fate of the insulating snow cover. 'Rain-on-snow' events and warm spells during winter can lead to thaw-freeze cycles, compacted snow and ice encasement, as well as local flooding. These adverse conditions could counteract the otherwise positive effects of climatic changes on forest seedling growth. In order to study the effects of different winter and snow conditions on young Scots pine (Pinus sylvestris L.) seedlings, we conducted a laboratory experiment in which 80 1-year-old Scots pine seedlings were distributed between four winter treatments in dasotrons: ambient snow cover (SNOW), compressed snow and ice encasement (ICE), flooded and frozen soil (FLOOD) and no snow (NO SNOW). During the winter treatment period and a 1.5-month simulated spring/early summer phase, we monitored the needle, stem and root biomass of the seedlings, and determined their starch and soluble sugar concentrations. In addition, we assessed the stress experienced by the seedlings by measuring chlorophyll fluorescence, electric impedance and photosynthesis of the previous-year needles. Compared with the SNOW treatment, carbohydrate concentrations were lower in the FLOOD and NO SNOW treatments where the seedlings had almost died before the end of the experiment, presumably due to frost desiccation of aboveground parts during the winter treatments. The seedlings of the ICE treatment showed dead needles and stems only above the snow and ice cover. The results emphasize the importance of an insulating and protecting snow cover for small forest tree seedlings, and that future winters with changed snow patterns might affect the survival of tree seedlings and thus forest productivity.

Winter climate limits subantarctic low forest growth and establishment.

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Melanie A Harsch

Full Text Available Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E is oceanic (Conrad Index of Continentality  =  -5 with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C, dry winters (total winter precipitation <400 mm. Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

Winter Climate Limits Subantarctic Low Forest Growth and Establishment

Science.gov (United States)

Harsch, Melanie A.; McGlone, Matt S.; Wilmshurst, Janet M.

2014-01-01

Campbell Island, an isolated island 600 km south of New Zealand mainland (52°S, 169°E) is oceanic (Conrad Index of Continentality  = −5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6°C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally. PMID:24691026

Regional meteorological drivers and long term trends of winter-spring nitrate dynamics across watersheds in northeastern North America

Science.gov (United States)

Crossman, Jill; Eimers, M Catherine; Casson, Nora J.; Burns, Douglas A.; Campbell, John L.; Likens, Gene E; Mitchell, Myron J; Nelson, Sarah J.; Shanley, James B.; Watmough, Shaun A.; Webster, Kara L

2016-01-01

This study evaluated the contribution of winter rain-on-snow (ROS) events to annual and seasonal nitrate (N-NO3) export and identified the regional meteorological drivers of inter-annual variability in ROS N-NO3 export (ROS-N) at 9 headwater streams located across Ontario, Canada and the northeastern United States. Although on average only 3.3 % of annual precipitation fell as ROS during winter over the study period, these events contributed a significant proportion of annual and winter N-NO3 export at the majority of sites (average of 12 and 42 %, respectively); with the exception of the most northern catchment, where total winter precipitation was exceptionally low (average 77 mm). In years with a greater magnitude of ROS events, the timing of the peak N-NO3 export period (during spring melt) was redistributed to earlier in the year. Variability in ROS frequency and magnitude amongst sites was high and a generalised linear model demonstrated that this spatial variability could be explained by interactive effects between regional and site-specific drivers. Snowpack coverage was particularly important for explaining the site-specific ROS response. Specifically, ROS events were less common when higher temperatures eliminated snow cover despite increasing the proportion of winter rainfall, whereas ROS event frequency was greater at sites where sufficient snow cover remained. This research suggests that catchment response to changes in N deposition is sensitive to climate change; a vulnerability which appears to vary in intensity throughout the seasonally snow-covered temperate region. Furthermore, the sensitivity of stream N-NO3 export to ROS events and potential shifts (earlier) in the timing of N-NO3 export relative to other nutrients affect downstream nutrient stoichiometry and the community composition of phytoplankton and other algae.

Late winter biogeochemical conditions under sea ice in the Canadian High Arctic

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Helen S. Findlay

2015-12-01

Full Text Available With the Arctic summer sea-ice extent in decline, questions are arising as to how changes in sea-ice dynamics might affect biogeochemical cycling and phenomena such as carbon dioxide (CO2 uptake and ocean acidification. Recent field research in these areas has concentrated on biogeochemical and CO2 measurements during spring, summer or autumn, but there are few data for the winter or winter–spring transition, particularly in the High Arctic. Here, we present carbon and nutrient data within and under sea ice measured during the Catlin Arctic Survey, over 40 days in March and April 2010, off Ellef Ringnes Island (78° 43.11′ N, 104° 47.44′ W in the Canadian High Arctic. Results show relatively low surface water (1–10 m nitrate (<1.3 µM and total inorganic carbon concentrations (mean±SD=2015±5.83 µmol kg−1, total alkalinity (mean±SD=2134±11.09 µmol kg−1 and under-ice pCO2sw (mean±SD=286±17 µatm. These surprisingly low wintertime carbon and nutrient conditions suggest that the outer Canadian Arctic Archipelago region is nitrate-limited on account of sluggish mixing among the multi-year ice regions of the High Arctic, which could temper the potential of widespread under-ice and open-water phytoplankton blooms later in the season.

Radioresistance in Central Asian tortoise

Energy Technology Data Exchange (ETDEWEB)

Turdyev, A.A.; Bogdanova-Berezovskaya, I.G.; Dvornikova, L.I.

Season-related studies were conducted on the phenomenal radioresistance of the Central Asian tortoise (Testudo horsfieldii), in order to obtain greater understanding of the factors that determine this physiological uniqueness. Test animals were exposed to gamma radiation from a Co-60 source with dosages ranging from 12.9 to 25.8 Cl/kg in the spring, summer, fall, and winter. Using Pearson's ..gamma..-distribution coefficient calculations of the mean lethal dose for the season yielded 16.33 Cl/kg for winter, 10.94 Cl/kg for spring, 7.1 Cl/kg for summer, and 19.71 Cl/kg for fall. The animals were thus seen to be most susceptible to radiation damage in the spring and summer. Correlation with histological and hematological studies showed that animals irradiated in spring and summer succumbed as a result of damage to the GI and the hematopoietic systems, whereas animals that died as a result of irradiation during the fall and winter season did so because of depletion of hepatic glycogen stores. 5 references, 1 figure.

Storing snow for the next winter: Two case studies on the application of snow farming.

Science.gov (United States)

Grünewald, Thomas; Wolfsperger, Fabian

2016-04-01

Snow farming is the conservation of snow during the warm half-year. This means that large piles of snow are formed in spring in order to be conserved over the summer season. Well-insulating materials such as chipped wood are added as surface cover to reduce melting. The aim of snow farming is to provide a "snow guaranty" for autumn or early winter - this means that a specific amount of snow will definitively be available, independent of the weather conditions. The conserved snow can then be used as basis for the preparation of winter sports grounds such as cross-country tracks or ski runs. This helps in the organization of early winter season sport events such as World Cup races or to provide appropriate training conditions for athletes. We present a study on two snow farming projects, one in Davos (Switzerland) and one in the Martell valley of South Tyrol. At both places snow farming has been used for several years. For the summer season 2015, we monitored both snow piles in order to assess the amount of snow conserved. High resolution terrestrial laser scanning was performed to measure snow volumes of the piles at the beginning and at the end of the summer period. Results showed that only 20% to 30 % of the snow mass was lost due to ablation. This mass loss was surprisingly low considering the extremely warm and dry summer. In order to identify the most relevant drivers of snow melt we also present simulations with the sophisticated snow cover models SNOWPACK and Alpine3D. The simulations are driven by meteorological input data recorded in the vicinity of the piles and enable a detailed analysis of the relevant processes controlling the energy balance. The models can be applied to optimize settings for snow farming and to examine the suitability of new locations, configurations or cover material for future snow farming projects.

Limnology of Sawtooth Lakes - 1995: Effects of winter limnology and lake fertilization on potential production of Snake River sockeye salmon

International Nuclear Information System (INIS)

Luecke, C.; Wurtsbaugh, W.A.; Budy, P.; Steinhart, G.B.; Slater, M.

1996-01-01

This Section II of the entire report describes the results of the limnological sampling conducted on Redfish, Altras, Pettit and Stanley Lakes from October 1994 through October 1995. Included are descriptions of winter limnological conditions and kokanee growth characteristics from 1993 to 1995, limnological conditions during the spring, summer and fall of 1995, comparison of characteristics among the four lakes; fertilization of Redfish Lake in 1995; effects of fertilization and effects of annual avriations in planktivorous fish abundance. Individual chapters and their subject areas are listed in following abstracts

Limnology of Sawtooth Lakes - 1995: Effects of winter limnology and lake fertilization on potential production of Snake River sockeye salmon

Energy Technology Data Exchange (ETDEWEB)

Luecke, C.; Wurtsbaugh, W.A.; Budy, P.; Steinhart, G.B.; Slater, M.

1996-05-01

This Section II of the entire report describes the results of the limnological sampling conducted on Redfish, Altras, Pettit and Stanley Lakes from October 1994 through October 1995. Included are descriptions of winter limnological conditions and kokanee growth characteristics from 1993 to 1995, limnological conditions during the spring, summer and fall of 1995, comparison of characteristics among the four lakes; fertilization of Redfish Lake in 1995; effects of fertilization and effects of annual avriations in planktivorous fish abundance. Individual chapters and their subject areas are listed in following abstracts.

Kootenai River Wildlife Habitat Enhancement Project : Long-term Bighorn Sheep/Mule Deer Winter and Spring Habitat Improvement Project : Wildlife Mitigation Project, Libby Dam, Montana : Management Plan.

Energy Technology Data Exchange (ETDEWEB)

Yde, Chis

1990-06-01

The Libby hydroelectric project, located on the Kootenai River in northwestern Montana, resulted in several impacts to the wildlife communities which occupied the habitats inundated by Lake Koocanusa. Montana Department of Fish, Wildlife and Parks, in cooperation with the other management agencies, developed an impact assessment and a wildlife and wildlife habitat mitigation plan for the Libby hydroelectric facility. In response to the mitigation plan, Bonneville Power Administration funded a cooperative project between the Kootenai National Forest and Montana Department of Fish, Wildlife and Parks to develop a long-term habitat enhancement plan for the bighorn sheep and mule deer winter and spring ranges adjacent to Lake Koocanusa. The project goal is to rehabilitate 3372 acres of bighorn sheep and 16,321 acres of mule deer winter and spring ranges on Kootenai National Forest lands adjacent to Lake Koocanusa and to monitor and evaluate the effects of implementing this habitat enhancement work. 2 refs.

Effects of Wintering Environment and Parasite-Pathogen Interactions on Honey Bee Colony Loss in North Temperate Regions.

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Suresh D Desai

Full Text Available Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. We monitored colonies in two environments (colonies wintered indoors or outdoors and characterized the effects of two parasitic mites, seven viruses, and Nosema on honey bee colony mortality and population loss over winter. Samples were collected from two locations within hives in fall, mid-winter and spring of 2009/2010. Although fall parasite and pathogen loads were similar in outdoor and indoor-wintered colonies, the outdoor-wintered colonies had greater relative reductions in bee population score over winter. Seasonal patterns in deformed wing virus (DWV, black queen cell virus (BQCV, and Nosema level also differed with the wintering environment. DWV and Nosema levels decreased over winter for indoor-wintered colonies but BQCV did not. Both BQCV and Nosema concentration increased over winter in outdoor-wintered colonies. The mean abundance of Varroa decreased and concentration of Sacbrood virus (SBV, Kashmir bee virus (KBV, and Chronic bee paralysis virus (CBPV increased over winter but seasonal patterns were not affected by wintering method. For most viruses, either entrance or brood area samples were reasonable predictors of colony virus load but there were significant season*sample location interactions for Nosema and BQCV, indicating that care must be taken when selecting samples from a single location. For Nosema spp., the fall entrance samples were better predictors of future infestation levels than were fall brood area samples. For indoor-wintered colonies, Israeli acute paralysis virus IAPV concentration was negatively correlated with spring population size. For outdoor-wintered hives, spring Varroa abundance and DWV concentration were positively correlated with bee loss and negatively correlated with spring population size. Multivariate analyses for fall collected samples indicated

The changes in the fibrinogen concentration and coagulation pathways in winter and summer in cattle

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ameneh khoshvaghti

2013-08-01

Full Text Available Fibrinogen is an important coagulation factor and a positive acute phase protein and its levels increases in cases of inflammation infection and stress. The present research was done to determine whether the fibrinogen concentration, prothrombin time (PT and activated partial thromboplastin time (APTT can be affected by seasonal changes. In this study, the blood of ten apparently healthy cows from around Yasouj city were taken under aseptic conditions and, then the plasma was separated. The fibrinogen concentration, was assayed by sedimentation refractometry method, PT and APTT were measurement by coagolometric method. The statistical analysis indicated that there was significant difference between the mean concentration of fibrinogen in summer and winter (P0.05. It is concluded that seasonal changes can affect the fibrinogen concentration but does no affect PT and APTT significantly.

Dynamics of late spring and summer phytoplankton communities on Georges Bank, with emphasis on diatoms, Alexandrium spp., and other dinoflagellates

Science.gov (United States)

Gettings, Rachel M.; Townsend, David W.; Thomas, Maura A.; Karp-Boss, Lee

2014-05-01

We analyzed the distribution, abundance, and succession patterns of major phytoplankton taxa on Georges Bank in relation to hydrography, nutrients, and size-fractionated chlorophyll concentrations (>20 μm; Gymnodinium spp., and Prorocentrum spp., had become more abundant. Patches of regenerated silicate during the June-July period appeared to support a post-spring-bloom diatom community on the central crest of the Bank (total diatom cell densities >180,000 cellsl-1) of Leptocylindrus spp., Dactyliosolen spp., and Guinardia flaccida. Multivariate statistical analyses of phytoplankton taxa and station locations revealed distinct assemblages of diatom and dinoflagellate taxa on the Bank throughout the late spring and summer. Results are interpreted in the ecological context of earlier-reported laboratory culture experiments on the competitive interactions between Alexandrium fundyense and diatoms.

Composition and sources of winter and summertime aerosols at Ny Alesund, Spitsbergen

International Nuclear Information System (INIS)

Maenhaut, W.; Cornille, P.; Pacyna, J.M.

1991-01-01

Filter samples of < 2.5 μm aerosol were collected in (late) winter of 1983, 1984, 1986, and 1987 and in the summer of 1984, 1986, and 1987 at Ny Alesund, Spitsbergen, and analyzed for over 40 elements by a combination of INAA and PIXE. The data sets of the various sampling campaigns and the combined winter and combined summer data were examined by receptor modeling, including absolute principal component analysis (APCA), chemical mass balance (CMB) and multiple linear regression (MLR) techniques. APCA yielded four components, both for the winter and for the summer aerosol. For the winter aerosol, the components were identified as a general pollution component, crustal dust, sea-salt, and a halogen (Br,I) component. The CMB and MLR calculations were used to obtain source (source region) apportionments for the anthropogenic trace elements and for sulfate. For the summer, about 50% of the sulfate was attributed to a marine biogenic source

Holocene seasonal variability inferred from multiple proxy records from Crevice Lake, Yellowstone National Park, USA

Science.gov (United States)

Whitlock, Cathy; Dean, Walter E.; Fritz, Sherilyn C.; Stevens, Lora R.; Stone, Jeffery R.; Power, Mitchell J.; Rosenbaum, Joseph R.; Pierce, Kenneth L.; Bracht-Flyr, Brandi B.

2012-01-01

A 9400-yr-old record from Crevice Lake, a semi-closed alkaline lake in northern Yellowstone National Park, was analyzed for pollen, charcoal, geochemistry, mineralogy, diatoms, and stable isotopes to develop a nuanced understanding of Holocene environmental history in a region of northern Rocky Mountains that receives both summer and winter precipitation. The limited surface area, conical bathymetry, and deep water (> 31 m) of Crevice Lake create oxygen-deficient conditions in the hypolimnion and preserve annually laminated sediment (varves) for much of the record. Pollen data indicate that the watershed supported a closed Pinus-dominated forest and low fire frequency prior to 8200 cal yr BP, followed by open parkland until 2600 cal yr BP, and open mixed-conifer forest thereafter. Fire activity shifted from infrequent stand-replacing fires initially to frequent surface fires in the middle Holocene and stand-replacing events in recent centuries. Low values of δ18O suggest high winter precipitation in the early Holocene, followed by steadily drier conditions after 8500 cal yr BP. Carbonate-rich sediments before 5000 cal yr BP imply warmer summer conditions than after 5000 cal yr BP. High values of molybdenum (Mo), uranium (U), and sulfur (S) indicate anoxic bottom-waters before 8000 cal yr BP, between 4400 and 3900 cal yr BP, and after 2400 cal yr BP. The diatom record indicates extensive water-column mixing in spring and early summer through much of the Holocene, but a period between 2200 and 800 cal yr BP had strong summer stratification, phosphate limitation, and oxygen-deficient bottom waters. Together, the proxy data suggest wet winters, protracted springs, and warm effectively wet summers in the early Holocene and less snowpack, cool springs, warm dry summers in the middle Holocene. In the late Holocene, the region and lake experienced extreme changes in winter, spring, and summer conditions, with particularly short springs and dry summers and winters during

Establishment and verification of solar radiation calculation model of glass daylighting roof in hot summer and warm winter zone in China

OpenAIRE

Zheng, Caidan; Wu, Peihao; Costanzo, Vincenzo; Wang, Yuchen; Yang, Xiaokun

2017-01-01

In this paper, solar heat gain through glass daylighting roof is deeply studied by theoretical calculation method, taking Guangzhou in the Hot Summer and Warm Winter (HSWW) zone as an example. The direct solar radiation is calculated by Bouguer formula whereas the diffuse solar radiation is calculated by Berlage formula, representing the basis for the calculation method of the solar radiation intensity through the glass daylighting roof. Through the establishment of solar radiation calculatio...

Chemical and geochemical composition of spring-summer Arctic aerosol collected at Ny Alesund, Svalbard Islands.

Science.gov (United States)

Udisti, Roberto; Becagli, Silvia; Caiazzo, Laura; Cappelletti, David; Giardi, Fabio; Grotti, Marco; Lucarelli, Franco; Moroni, Beatrice; Nava, Silvia; Severi, Mirko; Traversi, Rita

2017-04-01

Since March 2010, spring-summer (usually March - September) campaigns were continuously carried out at the Italian Gruvebadet Observatory, Ny Alesund, Svalbard Island. Aerosol was sampled by PM10 (daily) and 4-stage (4-day resolution) collector devices and size distribution was evaluated at 10 min resolution in the range 10 nm - 20 um (106 size classes by a TSI SMPS-APS integrated system). Six-year (2010-2015) PM10 and size-segregated (>10, 10-2.5, 2.5-1, metal content (major and trace metals, including Rare Earth Elements - REEs, by PIXE and ICP-MS), Pb isotopic composition (by ICP-MS) and Elemental and Organic Carbon (EC-OC) concentrations. The data set was elaborated by multi-parametric statistical analysis (Positive Matrix Factorization - PMF), in order to identifying and quantifying the contribution of the main anthropic and natural aerosol sources. Particular attention was spent in evaluating the anthropic contribution of nss-sulphate, nitrate, EC and heavy metals during the Arctic Haze in spring. The isotopic composition of Pb was used in identifying the source areas (North America, Greenland, North Europe, Siberia, Iceland) of anthropic emissions as a function of seasonality (different atmospheric circulation pathway). Crustal metals and, especially, REEs anomalies (with respect to the Chondrite-normalized profile) allowed characterizing the dust emissions from their Potential Source Areas (PSA). Biogenic markers (especially methane sulfonic acid - MSA - and bio-nss-sulphate) was used to obtain relevant information about the relationship between marine biogenic activity (primary productivity) and sea ice coverage and atmospheric conditions (irradiance, temperature, circulation pathways). The seasonal pattern of the nitrate deposition was also investigated. Chemical and geochemical measurements were compared with high-resolution size distribution and back-trajectory cluster analysis in order to understand the seasonal pattern of the contributions of long

Seasonal Alterations in Park Visitation, Amenity Use, and Physical Activity — Grand Forks, North Dakota, 2012–2013

Science.gov (United States)

Johnson, LuAnn

2014-01-01

Introduction Park amenities promote visitation and physical activity during summer. Physical activity declines during winter. Identifying park amenities that promote visitation during winter would increase year-round activity. The purpose of this study was to determine how park visitation, amenity choice, and physical activity intensity change across seasons. Methods Physical activity intensity of children and adults was assessed at 16 parks in Grand Forks, North Dakota, during summer and fall of 2012, and winter and spring of 2013. Results Park visitation was highest in spring and lowest in winter. Amenity use varied by season. Parks with water splash pads were visited more during summer, and playgrounds and open spaces were visited more during spring. Ice rinks were visited most in winter. Physical activity intensity was lowest in summer and highest in winter for each age group. The activity intensity observed for all young age groups ranged from 2.7 to 2.9 metabolic equivalents in summer and greater than 3 metabolic equivalents in all other seasons. Adults’ mean activity intensity was greater than 3 metabolic equivalents in winter. Conclusion Information on park visitation, amenity use, and activity intensity across seasons is valuable; it can be used when designing or redesigning parks in order to promote year-round physical activity. Redesigning parks in cold climates to include ice rinks, sledding hills, cross-country skiing, and indoor areas for physical activity would increase winter visitation and allow the park to serve as a year-round resource for physical activity. PMID:25211503

A natural tracer investigation of the hydrological regime of Spring Creek Springs, the largest submarine spring system in Florida

Science.gov (United States)

Dimova, Natasha T.; Burnett, William C.; Speer, Kevin

2011-04-01

This work presents results from a nearly two-year monitoring of the hydrologic dynamics of the largest submarine spring system in Florida, Spring Creek Springs. During the summer of 2007 this spring system was observed to have significantly reduced flow due to persistent drought conditions. Our examination of the springs revealed that the salinity of the springs' waters had increased significantly, from 4 in 2004 to 33 in July 2007 with anomalous high radon ( 222Rn, t1/2=3.8 days) in surface water concentrations indicating substantial saltwater intrusion into the local aquifer. During our investigation from August 2007 to May 2009 we deployed on an almost monthly basis a continuous radon-in-water measurement system and monitored the salinity fluctuations in the discharge area. To evaluate the springs' freshwater flux we developed three different models: two of them are based on water velocity measurements and either salinity or 222Rn in the associated surface waters as groundwater tracers. The third approach used only salinity changes within the spring area. The three models showed good agreement and the results confirmed that the hydrologic regime of the system is strongly correlated to local precipitation and water table fluctuations with higher discharges after major rain events and very low, even reverse flow during prolong droughts. High flow spring conditions were observed twice during our study, in the early spring and mid-late summer of 2008. However the freshwater spring flux during our observation period never reached that reported from a 1970s value of 4.9×10 6 m 3/day. The maximum spring flow was estimated at about 3.0×10 6 m 3/day after heavy precipitation in February-March 2008. As a result of this storm (total of 173 mm) the salinity in the spring area dropped from about 27 to 2 in only two days. The radon-in-water concentrations dramatically increased in parallel, from about 330 Bq/m 3 to about 6600 Bq/m 3. Such a rapid response suggests a direct

Postharvest tillage reduces Downy Brome infestations in winter wheat

Science.gov (United States)

In the Pacific Northwest, downy brome continues to infest winter wheat producing regions especially in low-rainfall areas where the winter wheat-summer fallow rotation is the dominate production system. In Washington, a study was conducted for 2 years at each of two locations in the winter wheat -su...

Whole-stream metabolism of a perennial spring-fed aufeis field in Alaska, with coincident surface and subsurface flow

Science.gov (United States)

Hendrickson, P. J.; Gooseff, M. N.; Huryn, A. D.

2017-12-01

Aufeis (icings or naleds) are seasonal arctic and sub-arctic features that accumulate through repeated overflow and freeze events of river or spring discharge. Aufeis fields, defined as the substrate on which aufeis form and the overlaying ice, have been studied to mitigate impacts on engineering structures; however, ecological characteristics and functions of aufeis fields are poorly understood. The perennial springs that supply warm water to aufeis fields create unique fluvial habitats, and are thought to act as winter and summer oases for biota. To investigate ecosystem function, we measured whole-stream metabolism at the Kuparuk River Aufeis (North Slope, AK), a large ( 5 km2) field composed of cobble substrate and predominately subsurface flow dynamics. The single-station open channel diel oxygen method was utilized at several dissolved oxygen (DO) stations located within and downstream of the aufeis field. DO loggers were installed in August 2016, and data downloaded summer 2017. Daily ecosystem respiration (ER), gross primary production (GPP) and reaeration rates were modeled using BASE, a package freely available in the open-source software R. Preliminary results support net heterotrophy during a two-week period of DO measurements in the fall season when minimum ice extent is observed. GPP, ER, and net metabolism are greater at the upstream reach near the spring source (P/R = 0.53), and decrease as flow moves downstream. As flow exits the aufeis field, surface and subsurface flow are incorporated into the metabolism model, and indicate the stream system becomes dependent on autochthonous production (P/R = 0.91). Current work is directed towards spring and summer discharge and metabolic parameter estimation, which is associated with maximum ice extent and rapid melting of the aufeis feature.

Impacts of the leading modes of tropical Indian Ocean sea surface temperature anomaly on sub-seasonal evolution of the circulation and rainfall over East Asia during boreal spring and summer

Science.gov (United States)

Liu, Senfeng; Duan, Anmin

2017-02-01

The two leading modes of the interannual variability of the tropical Indian Ocean (TIO) sea surface temperature (SST) anomaly are the Indian Ocean basin mode (IOBM) and the Indian Ocean dipole mode (IODM) from March to August. In this paper, the relationship between the TIO SST anomaly and the sub-seasonal evolution of the circulation and rainfall over East Asia during boreal spring and summer is investigated by using correlation analysis and composite analysis based on multi-source observation data from 1979 to 2013, together with numerical simulations from an atmospheric general circulation model. The results indicate that the impacts of the IOBM on the circulation and rainfall over East Asia vary remarkably from spring to summer. The anomalous anticyclone over the tropical Northwest Pacific induced by the warm IOBM is closely linked with the Pacific-Japan or East Asia-Pacific teleconnection pattern, which persists from March to August. In the upper troposphere over East Asia, the warm phase of the IOBM generates a significant anticyclonic response from March to May. In June and July, however, the circulation response is characterized by enhanced subtropical westerly flow. A distinct anomalous cyclone is found in August. Overall, the IOBM can exert significant influence on the western North Pacific subtropical high, the South Asian high, and the East Asian jet, which collectively modulate the precipitation anomaly over East Asia. In contrast, the effects of the IODM on the climate anomaly over East Asia are relatively weak in boreal spring and summer. Therefore, studying the impacts of the TIO SST anomaly on the climate anomaly in East Asia should take full account of the different sub-seasonal response during boreal spring and summer.

Fish Research Project, Oregon, Investigations into the Early Life History of Naturally Produced Spring Chinook Salmon in the Grande Ronde River Basin, Annual Progress Report, Project Period: September 1, 1996 - August 31, 1997; ANNUAL

International Nuclear Information System (INIS)

Brian C. Jonasson; J. Vincent Tranquilli; MaryLouise Keefe; Richard W. Carmichael

1998-01-01

We have documented two general life history strategies utilized by juvenile spring chinook salmon in the Grande Ronde River basin: (1) juveniles migrate downstream out of summer rearing areas in the fall, overwinter in river valley habitats, and begin their seaward migration in the spring, and (2) juveniles remain in summer rearing areas through the winter and begin seaward migration in the spring. In migration year 96-97, the patterns evident from migrant trap data were similar for the three Grande Ronde River populations studied, with 42% of the Lostine River migrants and 76% of the Catherine Creek migrants leaving upper rearing areas in the fall. Contrary to past years, the majority (98%) of upper Grande Ronde River migrants moved out in the fall. Total trap catch for the upper Grande Ronde River was exceedingly low (29 salmon), indicating that patterns seen this year may be equivocal. As in previous years, approximately 99% of chinook salmon juveniles moved past our trap at the lower end of the Grande Ronde River valley in the spring, reiterating that juvenile chinook salmon overwinter within the Grande Ronde valley section of the river. PIT-tagged fish were recaptured at Grande Ronde River traps and mainstem dams. Recapture data showed that fish that overwintered in valley habitats left as smolts and arrived at Lower Granite Dam earlier than fish that overwintered in upstream rearing areas. Fish from Catherine Creek that overwintered in valley habitats were recaptured at the dams at a higher rate than fish that overwintered upstream. In this first year of data for the Lostine River, fish tagged during the fall migration were detected at a similar rate to fish that overwintered upstream. Abundance estimates for migration year 96-97 were 70 for the upper Grande Ronde River, 4,316 for the Catherine Creek, and 4,323 for the Lostine River populations. Although present in most habitats, juvenile spring chinook salmon were found in the greatest abundance in pool

Iodine isotopes in precipitation: Four-year time series variations before and after 2011 Fukushima nuclear accident

DEFF Research Database (Denmark)

Xu, Sheng; Zhang, Luyuan; Freeman, Stewart P. H. T.

2016-01-01

values in winter and spring-summer. The high 129I levels in winter and spring-summer are most likely attributed to local resuspension of the Fukushima-derived radionuclide-bearing fine soil particles deposited on land surfaces, and re-emission through vegetation taking up 129I from contaminated soil...... and water, respectively. Long-term declining rate suggests that contribution of the Fukushima-derived 129I to the atmosphere would become less since 2014....

Trends in total and daily precipitation indices in japan from 1901 to 2000

OpenAIRE

Nagata, Rena; Zaiki, Masumi

2008-01-01

Long-term trends in seasonal precipitation amount and daily precipitation indices were investigated for spring, summer, autumn, and winter with a daily precipitation dataset for Japan from 1901 to 2000. Heavy precipitation in spring and summer has significantly increased along the west coast of Japan. Such changes in precipitation have resulted in the increased heavy precipitation intensity. For autumn and winter, total precipitation significantly decreased in the Kanto district and central J...

Escapement and Productivity of Spring Chinook and Summer Steelhead in the John Day River Basin, Technical Report 2004-2005.

Energy Technology Data Exchange (ETDEWEB)

Wilson, Wayne

2007-04-01

The objectives are: (1) Estimate number and distribution of spring Chinook salmon Oncorhynchus tshawytscha redds and spawners in the John Day River subbasin; and (2) Estimate smolt-to-adult survival rates (SAR) and out-migrant abundance for spring Chinook and summer steelhead O. mykiss and life history characteristics of summer steelhead. Spawning ground surveys for spring (stream-type) Chinook salmon were conducted in four main spawning areas (Mainstem, Middle Fork, North Fork, and Granite Creek System) and seven minor spawning areas (South Fork, Camas Creek, Desolation Creek, Trail Creek, Deardorff Creek, Clear Creek, and Big Creek) in the John Day River basin during August and September of 2005. Census surveys included 298.2 river kilometers (88.2 rkm within index, 192.4 rkm additional within census, and 17.6 rkm within random survey areas) of spawning habitat. We observed 902 redds and 701 carcasses including 227 redds in the Mainstem, 178 redds in the Middle Fork, 420 redds in the North Fork, 62 redds in the Granite Creek System, and 15 redds in Desolation Creek. Age composition of carcasses sampled for the entire basin was 1.6% age 3, 91.2% age 4, and 7.1% age 5. The sex ratio was 57.4% female and 42.6% male. Significantly more females than males were observed in the Granite Creek System. During 2005, 82.3% of female carcasses sampled had released all of their eggs. Significantly more pre-spawn mortalities were observed in Granite Creek. Nine (1.3%) of 701 carcasses were of hatchery origin. Of 298 carcasses examined, 4.0% were positive for the presence of lesions. A significantly higher incidence of gill lesions was found in the Granite Creek System when compared to the rest of the basin. Of 114 kidney samples tested, two (1.8%) had clinical BKD levels. Both infected fish were age-4 females in the Middle Fork. All samples tested for IHNV were negative. To estimate spring Chinook and summer steelhead smolt-to-adult survival (SAR) we PIT tagged 5,138 juvenile

CEBAF/SURA 1985 Summer Workshop

International Nuclear Information System (INIS)

Crannel, H.

1985-12-01

The 1985 Summer Workshop began a new phase of planning for the experimental program at CEBAF. One goal of the Workshop was to define and describe options for equipping the CEBAF and stations with experimental equipment. Starting with an initial list of options which grew out of discussions during the Winter of 1984 and the Spring of 1985, the five working groups met during the Workshop and developed their final reports, included in these proceedings. The program of the Workshop consisted of invited talks on both theoretical and experimental topics, and working group meetings. The five working groups, include: Magnetic Spectrometers; Large Acceptance Detectors and Low Intensity Beams; Internal Targets; Positrons; Theory. These proceedings begin with an overview of CEBAF, and a report on progress made by the Magnetic Spectrometer and Internal Target Working Groups prior to the Workshop. The next part contains the invited talks, presented in the order which they were given during the week. The final reports of the five working groups follow this, and the proceedings conclude with papers contributed to the Workshop

Do Peatlands Hibernate?

Science.gov (United States)

Dorrepaal, E.; Signarbieux, C.; Jassey, V.; Mills, R.; Buttler, A.; Robroek, B.

2014-12-01

Winter seasonality with extensive frost, snow cover and low incoming radiation characterise large areas at mid- and high latitudes, especially in mountain ranges and in the arctic. Given these adverse conditions, it is often assumed that ecosystem processes, such as plant photosynthesis, nutrient uptake and microbial activities, cease, or at best diminish to marginal rates compared to summer. However, snow is a good thermal insulator and a sufficiently thick snow cover might enable temperature-limited processes to continue in winter, especially belowground. Changes in winter precipitation may alter these conditions, yet, relative to the growing season, winter ecosystem processes remain poorly understood. We performed a snow-removal experiment on an ombrotrophic bog in the Swiss Jura mountains (1036 m.a.s.l.) to compare above- and belowground ecosystem processes with and without snow cover during mid- and late-winter (February and April) with the subsequent spring (June) and summer (July). The presence of 1m snow in mid-winter and 0.4m snow in late-winter strongly reduced the photosynthetic capacity (Amax) of Eriophorum vaginatum as well as the total microbial biomass compared to spring and summer values. Amax of Sphagnum magellanicum and uptake of 15N-labelled ammonium-nitrate by vascular plants were, however, almost as high or higher in mid- and late-winter as in summer. Snow removal increased the number of freeze-thaw cycles in mid-winter but also increased the minimum soil temperature in late-winter before ambient snow-melt. This strongly reduced all measured ecosystem processes in mid-winter compared to control and to spring and summer values. Plant 15N-uptake, Amax of Eriophorum and total microbial biomass returned to, or exceeded, control values soon before or after snowmelt. However, Sphagnum Amax and its length growth, as well as the structure of the microbial community showed clear carry-over effects of the reduced winter snow cover into next summer

Monitoring the Migrations of Wild Snake River Spring/Summer Chinook Salmon Smolts, 2000-2001 Annual Report.

Energy Technology Data Exchange (ETDEWEB)

Achord, Stephen; Axel, Gordon A.; Hockersmith, Eric E.

2002-07-01

This report details the 2001 results from an ongoing project to monitor the migration behavior of wild spring/summer chinook salmon smolts in the Snake River Basin. The report also discusses trends in the cumulative data collected for this project from Oregon and Idaho streams since 1989. The project was initiated after detection data from passive-integrated-transponder tags (PIT tags) had shown distinct differences in migration patterns between wild and hatchery fish for three consecutive years. National Marine Fisheries Service (NMFS) investigators first observed these data in 1989. The data originated from tagging and interrogation operations begun in 1988 to evaluate smolt transportation for the U.S. Army Corps of Engineers.

Vertical Distribution Characteristics of PM2.5 Observed by a Mobile Vehicle Lidar in Tianjin, China in 2016

Science.gov (United States)

Lyu, Lihui; Dong, Yunsheng; Zhang, Tianshu; Liu, Cheng; Liu, Wenqing; Xie, Zhouqing; Xiang, Yan; Zhang, Yi; Chen, Zhenyi; Fan, Guangqiang; Zhang, Leibo; Liu, Yang; Shi, Yuchen; Shu, Xiaowen

2018-02-01

We present mobile vehicle lidar observations in Tianjin, China during the spring, summer, and winter of 2016. Mobile observations were carried out along the city border road of Tianjin to obtain the vertical distribution characteristics of PM2.5. Hygroscopic growth was not considered since relative humidity was less than 60% during the observation experiments. PM2.5 profile was obtained with the linear regression equation between the particle extinction coefficient and PM2.5 mass concentration. In spring, the vertical distribution of PM2.5 exhibited a hierarchical structure. In addition to a layer of particles that gathered near the ground, a portion of particles floated at 0.6-2.5-km height. In summer and winter, the fine particles basically gathered below 1 km near the ground. In spring and summer, the concentration of fine particles in the south was higher than that in the north because of the influence of south wind. In winter, the distribution of fine particles was opposite to that measured during spring and summer. High concentrations of PM2.5 were observed in the rural areas of North Tianjin with a maximum of 350 μg m-3 on 13 December 2016. It is shown that industrial and ship emissions in spring and summer and coal combustion in winter were the major sources of fine particles that polluted Tianjin. The results provide insights into the mechanisms of haze formation and the effects of meteorological conditions during haze-fog pollution episodes in the Tianjin area.

Severe dry winter affects plant phenology and carbon balance of a cork oak woodland understorey

Science.gov (United States)

Correia, A. C.; Costa-e-Silva, F.; Dubbert, M.; Piayda, A.; Pereira, J. S.

2016-10-01

Mediterranean climates are prone to a great variation in yearly precipitation. The effects on ecosystem will depend on the severity and timing of droughts. In this study we questioned how an extreme dry winter affects the carbon flux in the understorey of a cork oak woodland? What is the seasonal contribution of understorey vegetation to ecosystem productivity? We used closed-system portable chambers to measure CO2 exchange of the dominant shrub species (Cistus salviifolius, Cistus crispus and Ulex airensis), of the herbaceous layer and on bare soil in a cork oak woodland in central Portugal during the dry winter year of 2012. Shoot growth, leaf shedding, flower and fruit setting, above and belowground plant biomass were measured as well as seasonal leaf water potential. Eddy-covariance and micrometeorological data together with CO2 exchange measurements were used to access the understorey species contribution to ecosystem gross primary productivity (GPP). The herbaceous layer productivity was severely affected by the dry winter, with half of the yearly maximum aboveground biomass in comparison with the 6 years site average. The semi-deciduous and evergreen shrubs showed desynchronized phenophases and lagged carbon uptake maxima. Whereas shallow-root shrubs exhibited opportunistic characteristics in exploiting the understorey light and water resources, deep rooted shrubs showed better water status but considerably lower assimilation rates. The contribution of understorey vegetation to ecosystem GPP was lower during summer with 14% and maximum during late spring, concomitantly with the lowest tree productivity due to tree canopy renewal. The herbaceous vegetation contribution to ecosystem GPP never exceeded 6% during this dry year stressing its sensitivity to winter and spring precipitation. Although shrubs are more resilient to precipitation variability when compared with the herbaceous vegetation, the contribution of the understorey vegetation to ecosystem GPP can

Correlation analyses of Baltic Sea winter water mass formation and its impact on secondary and tertiary production

Directory of Open Access Journals (Sweden)

Jörn Schmidt

2007-09-01

Full Text Available The thermal stratification of the upper water layers in the BalticSea varies seasonally in response to the annual cycle of solarheating and wind-induced mixing. In winter, the stratificationdown to the halocline is almost completely eroded by convectionand strong wind mixing. Monthly averaged temperature profilesobtained from the ICES hydrographic database were used to studythe long-term variability (1950 to 2005 of winter water massformation in different deep basins of the Baltic Sea east ofthe island of Bornholm. Besides strong interannual variabilityof deep winter water temperatures, the last two decades showa positive trend (increase of 1-1.5°C. Correlationsof winter surface temperatures to temperatures of the winterwater body located directly above or within the top of the haloclinewere strongly positive until the autumn months. Such a closecoupling allows sea surface temperatures in winter to be usedto forecast the seasonal development of the thermal signaturein deeper layers with a high degree of confidence. The most significantimpact of winter sea surface temperatures on the thermal signaturein this depth range can be assigned to February/March. Strongersolar heating during spring and summer results in thermal stratificationof the water column leading to a complete decoupling of surfaceand deep winter water temperatures. Based on laboratory experiments,temperature-dependent relationships were utilised to analyseinterannual variations of biological processes with special emphasison the upper trophic levels (e.g., stage-specific developmentalrates of zooplankton and survival rates of fish eggs.

On the relationship between the early spring Indian Ocean's sea surface temperature (SST) and the Tibetan Plateau atmospheric heat source in summer

Science.gov (United States)

Ji, Chenxu; Zhang, Yuanzhi; Cheng, Qiuming; Li, Yu; Jiang, Tingchen; San Liang, X.

2018-05-01

In this study, we evaluated the effects of springtime Indian Ocean's sea surface temperature (SST) on the Tibetan Plateau's role as atmospheric heat source (AHS) in summer. The SST data of the National Oceanic and Atmospheric Administration (NOAA), European Centre for Medium-Range Weather Forecasts (ECMWF) and the Hadley Centre Sea Ice and Sea Surface Temperature data set (HadISST) and the reanalysis data of the National Center for Environmental Prediction (NCEP) and National Center for Atmospheric Research (NCAR) for 33 years (from 1979 to 2011) were used to analyze the relationship between the Indian Ocean SST and the Tibetan Plateau's AHS in summer, using the approaches that include correlation analysis, and lead-lag analysis. Our results show that some certain strong oceanic SSTs affect the summer plateau heat, specially finding that the early spring SSTs of the Indian Ocean significantly affect the plateau's ability to serve as a heat source in summer. Moreover, the anomalous atmospheric circulation and transport of water vapor are related to the Plateau heat variation.

Changes in atmospheric circulation between solar maximum and minimum conditions in winter and summer

Science.gov (United States)

Lee, Jae Nyung

2008-10-01

Statistically significant climate responses to the solar variability are found in Northern Annular Mode (NAM) and in the tropical circulation. This study is based on the statistical analysis of numerical simulations with ModelE version of the chemistry coupled Goddard Institute for Space Studies (GISS) general circulation model (GCM) and National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis. The low frequency large scale variability of the winter and summer circulation is described by the NAM, the leading Empirical Orthogonal Function (EOF) of geopotential heights. The newly defined seasonal annular modes and its dynamical significance in the stratosphere and troposphere in the GISS ModelE is shown and compared with those in the NCEP/NCAR reanalysis. In the stratosphere, the summer NAM obtained from NCEP/NCAR reanalysis as well as from the ModelE simulations has the same sign throughout the northern hemisphere, but shows greater variability at low latitudes. The patterns in both analyses are consistent with the interpretation that low NAM conditions represent an enhancement of the seasonal difference between the summer and the annual averages of geopotential height, temperature and velocity distributions, while the reverse holds for high NAM conditions. Composite analysis of high and low NAM cases in both the model and observation suggests that the summer stratosphere is more "summer-like" when the solar activity is near a maximum. This means that the zonal easterly wind flow is stronger and the temperature is higher than normal. Thus increased irradiance favors a low summer NAM. A quantitative comparison of the anti-correlation between the NAM and the solar forcing is presented in the model and in the observation, both of which show lower/higher NAM index in solar maximum/minimum conditions. The summer NAM in the troposphere obtained from NCEP/NCAR reanalysis has a dipolar zonal structure with maximum

Greenhouse gases emission from the sewage draining rivers.

Science.gov (United States)

Hu, Beibei; Wang, Dongqi; Zhou, Jun; Meng, Weiqing; Li, Chongwei; Sun, Zongbin; Guo, Xin; Wang, Zhongliang

2018-01-15

Carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) concentration, saturation and fluxes in rivers (Beitang drainage river, Dagu drainage rive, Duliujianhe river, Yongdingxinhe river and Nanyunhe river) of Tianjin city (Haihe watershed) were investigated during July and October in 2014, and January and April in 2015 by static headspace gas chromatography method and the two-layer model of diffusive gas exchange. The influence of environmental variables on greenhouse gases (GHGs) concentration under the disturbance of anthropogenic activities was discussed by Spearman correlative analysis and multiple stepwise regression analysis. The results showed that the concentration and fluxes of CO 2 , CH 4 and N 2 O were seasonally variable with >winter>fall>summer, spring>summer>winter>fall and summer>spring>winter>fall for concentrations and spring>summer>fall>winter, spring>summer>winter>fall and summer>spring>fall>winter for fluxes respectively. The GHGs concentration and saturation were higher in comprehensively polluted river sites and lower in lightly polluted river sites. The three GHGs emission fluxes in two sewage draining rivers of Tianjin were clearly higher than those of other rivers (natural rivers) and the spatial variation of CH 4 was more obvious than the others. CO 2 and N 2 O air-water interface emission fluxes of the sewage draining rivers in four seasons were about 1.20-2.41 times and 1.13-3.12 times of those in the natural rivers. The CH 4 emission fluxes of the sewage draining rivers were 3.09 times in fall to 10.87 times in spring of those in the natural rivers in different season. The wind speed, water temperature and air temperature were related to GHGs concentrations. Nitrate and nitrite (NO 3 - +NO 2 - -N) and ammonia (NH 4 + -N) were positively correlated with CO 2 concentration and CH 4 concentration; and dissolved oxygen (DO) concentration was negatively correlated with CH 4 concentration and N 2 O concentration. The effect of

Nitrate leaching in a winter wheat-summer maize rotation on a calcareous soil as affected by nitrogen and straw management.

Science.gov (United States)

Huang, Tao; Ju, Xiaotang; Yang, Hao

2017-02-08

Nitrate leaching is one of the most important pathways of nitrogen (N) loss which leads to groundwater contamination or surface water eutrophication. Clarifying the rates, controlling factors and characteristics of nitrate leaching is the pre-requisite for proposing effective mitigation strategies. We investigated the effects of interactions among chemical N fertilizer, straw and manure applications on nitrogen leaching in an intensively managed calcareous Fluvo-aquic soil with winter wheat-summer maize cropping rotations on the North China Plain from October 2010 to September 2013 using ceramic suction cups and seepage water calculations based on a long-term field experiment. Annual nitrate leaching reached 38-60 kg N ha -1 from conventional N managements, but declined by 32-71% due to optimum N, compost manure or municipal waste treatments, respectively. Nitrate leaching concentrated in the summer maize season, and fewer leaching events with high amounts are the characteristics of nitrate leaching in this region. Overuse of chemical N fertilizers, high net mineralization and nitrification, together with predominance of rainfall in the summer season with light soil texture are the main controlling factors responsible for the high nitrate leaching loss in this soil-crop-climatic system.

Maintaining the Background Dust Opacity During Northern Hemisphere Summer Mars Using Wind Stress Based Dust Lifting

Science.gov (United States)

Jha, V.; Kahre, M. A.

2017-12-01

The Mars atmosphere has low levels of dust during Northern Hemisphere (NH) spring and summer (the non-dusty season) and increased levels during NH autumn and winter (the dusty season). In the absence of regional or global storms, dust devils and local storms maintain a background minimum dust loading during the non-dusty season. While observational surveys and Global Climate Model (GCM) studies suggest that dust devils are likely to be major contributors to the background haze during NH spring and summer, a complete understanding of the relative contribution of dust devils and local dust storms has not yet been achieved. We present preliminary results from an investigation that focuses on the effects of radiatively active water ice clouds on dust lifting processes during these seasons. Water ice clouds are known to affect atmospheric temperatures directly by absorption and emission of thermal infrared radiation and indirectly through dynamical feedbacks. Our goal is to understand how clouds affect the contribution by local (wind stress) dust storms to the background dust haze during NH spring and summer. The primary tool for this work is the NASA Ames Mars GCM, which contains physical parameterizations for a fully interactive dust cycle. Three simulations that included wind stress dust lifting were executed for a period of 5 Martian years: a case that included no cloud formation, a case that included radiatively inert cloud formation and a case that included radiatively active cloud (RAC) formation. Results show that when radiatively active clouds are included, the clouds in the aphelion cloud belt radiatively heat the atmosphere aloft in the tropics (Figure 1). This heating produces a stronger overturning circulation, which in turn produces an enhanced low-level flow in the Hadley cell return branch. The stronger low-level flow drives higher surface stresses and increased dust lifting in those locations. We examine how realistic these simulated results are by

Migration patterns and wintering range of common loons breeding in the Northeastern United States

Science.gov (United States)

Kenow, K.P.; Adams, D.; Schoch, N.; Evers, D.C.; Hanson, W.; Yates, D.; Savoy, L.; Fox, T.J.; Major, A.; Kratt, R.; Ozard, J.

2009-01-01

A study, using satellite telemetry, was conducted to determine the precise migration patterns and wintering locations of Common Loons (Gavia immer) breeding in the northeastern United States. Transmitters were implanted in 17 loons (16 adults and one juvenile) that were captured on breeding lakes in New York, New Hampshire, and Maine during the summers of 2003, 2004, and 2005. Transmitters from ten of the birds provided adequate location data to document movement to wintering areas. Most adult loons appeared to travel non-stop from breeding lakes, or neighboring lakes (within 15 km), to the Atlantic coast. Adult loons marked in New Hampshire and Maine wintered 152 to 239 km from breeding lakes, along the Maine coast. Adult loons marked in the Adirondack Park of New York wintered along the coasts of Massachusetts (414 km from breeding lake), Rhode Island (362 km), and southern New Jersey (527 km). Most of the loons remained relatively stationary throughout the winter, but the size of individual wintering areas of adult loons ranged from 43 to 1,159 km 2, based on a 95% fixed kernel utilization distribution probability. A juvenile bird from New York made a number of stops at lakes and reservoirs en route to Long Island Sound (325 km from breeding lake). Maximum functional life of transmitters was about 12 months, providing an opportunity to document spring migration movements as well. This work provides essential information for development and implementation of regional Common Loon conservation strategies in the Northeastern U.S.

Comparative Survival Study (CSS) of Hatchery PIT-tagged Spring/Summer Chinook; Migration Years 1997-2002 Mark/Recapture Activities and Bootstrap Analysis, 2003-2004 Biennial Report.

Energy Technology Data Exchange (ETDEWEB)

Berggren, Thomas J.; Franzoni, Henry; Basham, Larry R. (Columbia Basin Fish and Wildlife Authority, Fish Passage Center, Portland, OR)

2003-11-01

The Comparative Survival Study (CSS) was initiated in 1996 as a multi-year program of the fishery agencies and tribes to estimate survival rates over different life stages for spring and summer Chinook (hereafter, Chinook) produced in major hatcheries in the Snake River basin and from selected hatcheries in the lower Columbia River. Much of the information evaluated in the CSS is derived from fish tagged with Passive Integrated Transponder (PIT) tags. A comparison of survival rates of Chinook marked in two different regions (which differ in the number of dams Chinook have to migrate through) provides insight into the effects of the Snake/Columbia hydroelectric system (hydrosystem). The CSS also compares the smolt-to-adult survival rates (SARs) for Snake River Chinook that were transported versus those that migrated in-river to below Bonneville Dam. Additional comparisons can be made within in-river experiences as well as comparison between the different collector projects from which smolts are transported. CSS also compares survival rates for wild Snake River spring and summer Chinook. These comparisons generate information regarding the relative effects of the current management actions used to recover this listed species. Scientists and managers have recently emphasized the importance of delayed hydrosystem mortality to long-term management decisions. Delayed hydrosystem mortality may be related to the smolts experience in the Federal Columbia River Power System, and could occur for both smolts that migrate in-river and smolts that are transported. The CSS PIT tag information on in-river survival rates and smolt-to-adult survival rates (SARs) of transported and in-river fish are relevant to estimation of ''D'', which partially describes delayed hydrosystem mortality. The parameter D is the differential survival rate of transported fish relative to fish that migrate in-river, as measured from below Bonneville Dam to adults returning to Lower

Perspectives in Winter Limnology: Closing the annual cycle of freezing lakes

NARCIS (Netherlands)

Salonen, K.; Leppäranta, M.; Viljanen, M.; Gulati, R.D.

2009-01-01

Winter has traditionally been considered as an ecologically insignificant season and, together with technical difficulties, this has led winter limnology to lag behind summer limnology. Recently, rapidly expanding interest in climate warming has increased water research in winter. It has also become

Precipitation stable isotope records from the northern Hengduan Mountains in China capture signals of the winter India-Burma Trough and the Indian Summer Monsoon

Science.gov (United States)

Yu, Wusheng; Tian, Lide; Yao, Tandong; Xu, Baiqing; Wei, Feili; Ma, Yaoming; Zhu, Haifeng; Luo, Lun; Qu, Dongmei

2017-11-01

This project reports results of the first precipitation stable isotope (δ18 O and δD) time series produced for Qamdo in the northern Hengduan Mountains in the southeastern Tibetan Plateau. The data showed that the fluctuations of precipitation stable isotopes at Qamdo during the different seasons revealed various moisture sources. The westerlies and local recycling moisture dominated at the study area before the pre-monsoon and after the post-monsoon seasons, which resulted in similar trends of both precipitation stable isotopes and temperature. The marine moisture was transported to the northern Hengduan Mountains by the winter India-Burma Trough combined with convection. Consequently, stable isotopes in subsequent precipitation were occasionally observed to decrease suddenly. However, δ18 O and δD values of precipitation at Qamdo were lower during the monsoon period and the duration of those low values was longer because of the effects of the Indian Summer Monsoon and the strengthening convection. Our findings indicate that the effects of seasonal precipitation differences caused by various climate systems, including the winter India-Burma Trough and Indian Summer Monsoon, need to be considered when attempting to interpret tree-ring and ice core records for the Hengduan Mountains.

Trampoline-associated injuries are more common in children in spring.

Science.gov (United States)

Yule, Michael S; Krishna, Sanjeev; Rahiri, Jamie-Lee; Hill, Andrew G

2016-06-10

Trampoline use is a popular pastime amongst children in New Zealand, and has many advantages for child development. However, recent reports claim that trampoline-associated injuries are still highly prevalent. In order to help prevent these injuries in the future, this study aims to provide more up-to-date epidemiological information in children, with emphasis on the time of year that injuries most commonly occur. A retrospective review was carried out utilising a prospective maintained trauma database. The database was searched electronically for injuries involving trampolines in children aged 0-15 years. Patient demographics and information regarding month of injury, injury type and management were extracted. There were 344 admissions to hospital for trampoline-related injuries between June 2000 and January 2015. Injuries were uncommon in winter, but rose in spring and summer. Fracture of the radius and/or ulna was the most common injury (34.0%), followed by humeral fracture (32.0%). The peak incidence of trampoline-related injuries occurred around the beginning of spring daylight savings time each year. This could therefore prove an opportune time to remind children and parents about trampoline safety at the same time as daylight savings reminders.

Intraspecific Autochthonous and Allochthonous Resource Use by Zooplankton in a Humic Lake during the Transitions between Winter, Summer and Fall.

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Martin Berggren

Full Text Available Seasonal patterns in assimilation of externally produced, allochthonous, organic matter into aquatic food webs are poorly understood, especially in brown-water lakes. We studied the allochthony (share biomass of terrestrial origin in cladoceran, calanoid and cyclopoid micro-crustacean zooplankton from late winter to fall during two years in a small humic lake (Sweden. The use of allochthonous resources was important for sustaining a small population of calanoids in the water column during late winter. However, in summer the calanoids shifted to 100% herbivory, increasing their biomass several-fold by making efficient use of the pelagic primary production. In contrast, the cyclopoids and cladocerans remained at high levels of allochthony throughout the seasons, both groups showing the mean allochthony of 0.56 (range in mean 0.17-0.79 and 0.34-0.75, for the respective group, depending on model parameters. Our study shows that terrestrial organic matter can be an important resource for cyclopoids and cladocerans on an annual basis, forming a significant link between terrestrial organic matter and the higher trophic levels of the food web, but it can also be important for sustaining otherwise herbivorous calanoids during periods of low primary production in late winter.

Proteome Analysis of Cold Response in Spring and Winter Wheat (Triticum aestivum) Crowns Reveals Similarities in Stress Adaptation and Differences in Regulatory Processes between the Growth Habits

Czech Academy of Sciences Publication Activity Database

Kosová, K.; Vítámvás, P.; Planchon, S.; Renaut, J.; Vaňková, Radomíra; Prášil, I.T.

2013-01-01

Roč. 12, č. 11 (2013), s. 4830-4845 ISSN 1535-3893 R&D Projects: GA ČR GA522/09/2058 Institutional research plan: CEZ:AV0Z50380511 Keywords : 2D-DIGE analysis * cold stress * spring and winter growth habit Subject RIV: ED - Physiology Impact factor: 5.001, year: 2013

Applicability research on passive design of residential buildings in hot summer and cold winter zone in China

Science.gov (United States)

Zhang, Hui; Wang, Huihui; Zhou, Xuan

2017-04-01

Passive design has long been a concern as an effective way of building energy efficiency. However, different urban climate characteristics determine the time-effectiveness of passive design. According to the climate characteristics of hot summer and cold winter zone in China, this research chose five cities, Shanghai, Wuhan, Chongqing, Nanjing and Changsha, to analyze their residential building energy consumption and thermal environment conditions. Based on Weather Tool calculation and analysis, the purpose of this research is to put forward the concept of Suitable Degree (SD), namely the applicability of the passive design. In addition, five cities’ SD of passive design technology had been analyzed from aspect of ventilation, temperature, solar radiation and envelope, then passive design strategies and methods of five cities’ residential building were discussed.

Measurements of 427 Double Stars With Speckle Interferometry: The Winter/Spring 2017 Observing Program at Brilliant Sky Observatory, Part 1

Science.gov (United States)

Harshaw, Richard

2018-04-01

In the winter and spring of 2017, an aggressive observing program of measuring close double stars with speckle interferometry and CCD imaging was undertaken at Brilliant Sky Observatory, my observing site in Cave Creek, Arizona. A total of 596 stars were observed, 8 of which were rejected for various reasons, leaving 588 pairs. Of these, 427 were observed and measured with speckle interferometry, while the remaining 161 were measured with a CCD. This paper reports the results of the observations of the 427 speckle cases. A separate paper in this issue will report the CCD measurements of the 161 other pairs.

Life Cycle Assessment on Carbon Footprint of Winter Wheat-Summer Maize Cropping System Based on Survey Data of Gaomi in Shandong Province, China

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ZHU Yong-chang

2017-08-01

Full Text Available Grain production can generate huge amount of greenhouse gases through raw material production and energy comsumption, nitrogen fertilizer amendment and farming machinery operation. Based questionnaire survey of raw material inputs and management of wheat-maize cropping system in Gaomi, Shandong Province, carbon footprint of grain production was calculated using life cycle assessment methodology. Carbon footprint per unit area of wheat, maize, and winter wheat-summer maize cropping system were 5 183.33, 3 778.09 kg CO2-eq·hm-2 and 8 961.42 kg CO2-eq·hm-2, carbon footprint per unit grain yield were 0.69, 0.40 kg CO2-eq·kg-1 and 0.53 kg CO2-eq·kg-1, carbon footprint per unit net present value were 1.82, 0.40 kg CO2-eq·yuan-1 and 0.44 kg CO2-eq·yuan-1, respectively. Greenhouse gas(GHG emission of winter wheat-summer maize cropping system mainly came from nitrogen fertilizer production(48.30% and nitrogen fertilizer application(12.04%, irrigation electricity consumption(12.94% and machinery oil consumption(11.20%. Optimizing the application of fertilizer, reducing the amount of nitrogen fertilizer and saving water irrigation were important ways to realize the clean production.

The winter of 1827-1828 over eastern North America. A season of extraordinary climatic anomalies, societal impacts, and false spring

Energy Technology Data Exchange (ETDEWEB)

Mock, C.J.; McWaters, M. [Department of Geography, University of South Carolina, Columbia, SC, 29208 (United States); Mojzisek, J. [Department of Geography, University of Otago, P.O. Box 56, Dunedin, (New Zealand); Chenoweth, M. [Independent Scholar, 6816 Ducketts Lane, Elkridge, MD, 21075 (United States); Stahle, D.W. [Department of Geosciences, University of Arkansas, Fayetteville, AR, 72701 (United States)

2007-07-15

This study reconstructed the weather and its impacts on society for the winter of 1827-1828, focusing on the eastern United States. Data comprise of daily and monthly instrumental records, diaries with both daily and seasonal resolution, newspapers, fur trapper accounts, and tree-rings. Temperature anomalies were calculated and mapped based on the means during the 1820-1840 period to account for different fixed observation times. Precipitation frequencies provided direct comparisons of the 1827-1828 weather with modern climatic normals. Daily plots of temperature also reveal weather variations at daily timeframes. Results indicate that the eastern United States experienced strong positive temperature anomalies that are among the most extreme known in the historical record, particularly its large spatial extent. In contrast, historical evidence reveals strong negative temperature anomalies over northwestern North America, and positive temperature anomalies are evident for coastal Alaska. These temperature anomaly patterns sharply contrast to what is normally experienced during a warm El Nino event. Furthermore, results clearly describe remarkable climatic impacts in the Southeast U.S., including widespread blossoming of fruit trees in mid-winter (false spring) that led to a widespread severe killing frost in early April of 1828. Widespread positive precipitation frequency anomalies are also evident for much of the Southeast U.S., which also played a prominent role on winter vegetation growth. Other weather events and impacts include unusual opening of river traffic in winter in New England, severe flooding in the Mississippi River Valley, and heavy snowfall in northwestern North America.

Regional and climatic controls on seasonal dust deposition in the southwestern U.S.

Science.gov (United States)

Reheis, M.C.; Urban, F.E.

2011-01-01

Vertical dust deposition rates (dust flux) are a complex response to the interaction of seasonal precipitation, wind, changes in plant cover and land use, dust source type, and local vs. distant dust emission in the southwestern U.S. Seasonal dust flux in the Mojave-southern Great Basin (MSGB) deserts, measured from 1999 to 2008, is similar in summer-fall and winter-spring, and antecedent precipitation tends to suppress dust flux in winter-spring. In contrast, dust flux in the eastern Colorado Plateau (ECP) region is much larger in summer-fall than in winter-spring, and twice as large as in the MSGB. ECP dust is related to wind speed, and in the winter-spring to antecedent moisture. Higher summer dust flux in the ECP is likely due to gustier winds and runoff during monsoonal storms when temperature is also higher. Source types in the MSGB and land use in the ECP have important effects on seasonal dust flux. In the MSGB, wet playas produce salt-rich dust during wetter seasons, whereas antecedent and current moisture suppress dust emission from alluvial and dry-playa sources during winter-spring. In the ECP under drought conditions, dust flux at a grazed-and-plowed site increased greatly, and also increased at three annualized, previously grazed sites. Dust fluxes remained relatively consistent at ungrazed and currently grazed sites that have maintained perennial vegetation cover. Under predicted scenarios of future climate change, these results suggest that an increase in summer storms may increase dust flux in both areas, but resultant effects will depend on source type, land use, and vegetation cover. ?? 2011.

Isotope study in the Alpine karst region of Rawil (Switzerland)

International Nuclear Information System (INIS)

Schotterer, U.; Siegenthaler, U.; Oeschger, H.; Wildberger, A.; Nabholz, W.

1978-01-01

An isotope study in the karst of the high Alps in Switzerland is described. From 1973 to 1978 discharge, 3 H, delta 18 O, conductivity and temperature were measured in representative springs. The springs are influenced by snowmelt in late spring and summer, by rain in late summer and autumn, and in the winter period, when infiltration stops, by reservoir water. Since tritium in precipitation in the last years scattered irregularly in time and space, the residence time of winter baseflow (2-4 years) could not be determined very precisely. The pronounced difference in delta 18 O between several springs allowed us to estimate the difference in mean altitude of their recharge areas. (orig.) [de

Proteome dataset of subcutaneous adipose tissue obtained from late pregnant dairy cows during summer heat stress and winter seasons

Directory of Open Access Journals (Sweden)

M. Zachut

2017-06-01

Full Text Available Adipose tissue has a central role in the regulation of metabolism in dairy cows, and many proteins expressed in this tissue are involved in metabolic responses to stress (Peinado et al., 2012 [1]. Environmental heat stress is one of the main stressors limiting production in dairy cattle (Fuquay, 1981; West, 2003 [2,3], and there is a complex interaction between heat stress and the transition period from late pregnancy to onset of lactation, which is manifested in heat-stressed late-gestation cows (Tao and Dahl, 2013 [4]. We recently defined the proteome of adipose tissue in peripartum dairy cows, identifying 586 proteins of which 18.9% were differentially abundant in insulin-resistant compared to insulin-sensitive adipose tissue (Zachut, 2015 [5]. That study showed that proteomic techniques constitute a valuable tool for identifying novel biomarkers in adipose tissue that are related to metabolic adaptation to stress in dairy cows. The objective of the present work was to examine the adipose tissue proteome under thermo-neutral or seasonal heat stress conditions in late pregnant dairy cows. We have collected subcutaneous adipose tissue biopsies from 10 late pregnant dairy cows during summer heat stress and from 8 late pregnant dairy cows during winter season, and identified and quantified 1495 proteins in the adipose tissues. This dataset of adipose tissue proteome from dairy cows adds novel information on the variety of proteins that are abundant in this tissue during late pregnancy under thermo-neutral as well as heat stress conditions. Differential abundance of 107 (7.1% proteins was found between summer and winter adipose. These results are discussed in our recent research article (Zachut et al., 2017 [6].

Editorial - The winter Atomiades

CERN Multimedia

Staff Association

2011-01-01

As we wrote in our previous editorial, the Staff Association gives direct support to sports events, such as the Atomiades, a section of the Association of Sports Communities of European Research Institutes, which brings together sportsmen and women from 38 European research centres in 13 countries (Austria, Belgium, Czech Republic, United Kingdom, Finland, France, Germany, Hungary, Italy, Luxemburg, the Netherlands, Russia, and Switzerland). The summer Atomiades take place between the months of June and September every three years. Thirteen such events have taken place since 1973, the last one in June 2009 in Berlin. As far as the winter Atomiades are concerned, also organized every three years, and alternating with the summer Atomiades, there have been eleven since 1981, the last one at the end of January this year in neighbouring France. The following article tells the wonderful adventure of the CERN staff who took part in this event. A positive outcome for CERN skiers at the winter Atomiades The 11t...

Comparison of base flows to selected streamflow statistics representative of 1930-2002 in West Virginia

Science.gov (United States)

Wiley, Jeffrey B.

2012-01-01

Base flows were compared with published streamflow statistics to assess climate variability and to determine the published statistics that can be substituted for annual and seasonal base flows of unregulated streams in West Virginia. The comparison study was done by the U.S. Geological Survey, in cooperation with the West Virginia Department of Environmental Protection, Division of Water and Waste Management. The seasons were defined as winter (January 1-March 31), spring (April 1-June 30), summer (July 1-September 30), and fall (October 1-December 31). Differences in mean annual base flows for five record sub-periods (1930-42, 1943-62, 1963-69, 1970-79, and 1980-2002) range from -14.9 to 14.6 percent when compared to the values for the period 1930-2002. Differences between mean seasonal base flows and values for the period 1930-2002 are less variable for winter and spring, -11.2 to 11.0 percent, than for summer and fall, -47.0 to 43.6 percent. Mean summer base flows (July-September) and mean monthly base flows for July, August, September, and October are approximately equal, within 7.4 percentage points of mean annual base flow. The mean of each of annual, spring, summer, fall, and winter base flows are approximately equal to the annual 50-percent (standard error of 10.3 percent), 45-percent (error of 14.6 percent), 75-percent (error of 11.8 percent), 55-percent (error of 11.2 percent), and 35-percent duration flows (error of 11.1 percent), respectively. The mean seasonal base flows for spring, summer, fall, and winter are approximately equal to the spring 50- to 55-percent (standard error of 6.8 percent), summer 45- to 50-percent (error of 6.7 percent), fall 45-percent (error of 15.2 percent), and winter 60-percent duration flows (error of 8.5 percent), respectively. Annual and seasonal base flows representative of the period 1930-2002 at unregulated streamflow-gaging stations and ungaged locations in West Virginia can be estimated using previously published

Sex-related differences in hemato-biochemical indices of adult Vanaraja chickens during summer and winter seasons

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Kuldeep Kumar Panigrahy

2017-02-01

Full Text Available Aim: The objective of this study was to evaluate the changes in hemato-biochemical indices in male and female Vanaraja chickens under tropical environment during summer and winter season. Materials and Methods: A total of 120 day-old sexed Vanaraja chicks were selected as experimental chickens and distributed equally in two groups having 60 female and 60 male chickens in each group, respectively. The experiment was continued for 8 weeks (56 days and both male and female chickens were slaughtered by cervical dislocation method. All parameters were estimated at the end of the experiment in both seasons. Results: Male had higher blood glucose, Ca and P level. Blood glucose level significantly (p0.05 effect in most of the observed parameters. Hence, Vanaraja chickens are adaptable to local tropical climate and can be reared efficiently as backyard poultry.

Water relations, stomatal response and transpiration of Quercus pubescens trees during summer in a Mediterranean carbon dioxide spring

Energy Technology Data Exchange (ETDEWEB)

Tognetti, R.; Miglietta, F.; Raschi, A. [Consiglio Nazionale della Ricerche, Firenze (Italy); Longobucco, A. [Centro Studi per l`Informatica applicata all`Agricoltura, Firenze (Italy)

1999-04-01

Variations in water relations and stomatal response of downy oak (Quercus pubescens) were analyzed under Mediterranean field conditions during two consecutive summers at two locations characterized by different atmospheric CO{sub 2} concentrations due to the presence of a CO{sub 2} spring at one of the locations. The heat-pulse velocity technique was used to estimate water use during a five-month period from June to November 1994. At the end of the sap flow measurements, the trees were harvested and foliage and sapwood area measured. The effect of elevated CO{sub 2} concentration on leaf conductance was less at high leaf-to-air water vapour pressure difference than at low leaf-to-air water vapour pressure difference. Mean and diurnal sap fluxes were consistently higher in trees at the control site than in the trees at the CO{sub 2} spring site. Results are discussed in terms of effects of elevated CO{sub 2} concentration on plant water use at the organ and whole-tree level. 76 refs., 9 figs.

The penalty of a long, hot summer. Photosynthetic acclimation to high CO2 and continuous light in "living fossil" conifers.

Science.gov (United States)

Osborne, Colin P; Beerling, David J

2003-10-01

Deciduous forests covered the ice-free polar regions 280 to 40 million years ago under warm "greenhouse" climates and high atmospheric pCO2. Their deciduous habit is frequently interpreted as an adaptation for minimizing carbon losses during winter, but experiments with "living fossils" in a simulated warm polar environment refute this explanation. Measured carbon losses through leaf abscission of deciduous trees are significantly greater than losses through winter respiration in evergreens, yet annual rates of primary productivity are similar in all species. Here, we investigate mechanisms underlying this apparent paradox by measuring the seasonal patterns of leaf photosynthesis (A) under pCO2 enrichment in the same trees. During spring, A increased significantly in coastal redwood (Sequoia sempervirens), dawn redwood (Metasequoia glyptostroboides), and swamp cypress (Taxodium distichum) at an elevated pCO2 of 80 Pa compared with controls at 40 Pa. However, strong acclimation in Rubisco carboxylation capacity (Vc,max) completely offset the CO2 response of A in all species by the end of 6 weeks of continuous illumination in the simulated polar summer. Further measurements demonstrated the temporary nature of acclimation, with increases in Vc,max during autumn restoring the CO2 sensitivity of A. Contrary to expectations, the acclimation of Vc,max was not always accompanied by accumulation of leaf carbohydrates, but was associated with a decline in leaf nitrogen in summer, suggesting an alteration of the balance in plant sources and sinks for carbon and nitrogen. Preliminary calculations using A indicated that winter carbon losses through deciduous leaf abscission and respiration were recovered by 10 to 25 d of canopy carbon fixation during summer, thereby explaining the productivity paradox.

Taxa de gestação em fêmeas da raça Holandesa confinadas em free stall, no verão e inverno Gestation rate of Holstein females confined in free stall, during the summer and winter

Directory of Open Access Journals (Sweden)

M.F.A. Pires

2002-02-01

Full Text Available A taxa de gestação de vacas em lactação e de novilhas confinadas em free stall foi avaliada durante o inverno e o verão, nos anos de 1993, 1994 e 1995. A temperatura ambiente (TA e a umidade relativa do ar (UR foram acompanhadas diariamente, durante quatro meses de verão (dezembro a março e três meses de inverno (junho a agosto. Em cada estação mediram-se semanalmente às 9, 15 e 21h a temperatura retal (TR e a freqüência respiratória (FR de 50% das vacas em lactação, sorteadas ao acaso, separadas em quatro grupos de acordo com a produção de leite. A TA e o índice de temperatura e umidade (ITU médios foram mais elevados (P The gestation rate was used to evaluate the reproductive performance of dairy cows and heifers confined in a free stall barn during the winter and summer seasons of 1993, 1994 and 1995. The temperature (T and relative humidity (RH were monitored daily during the summer (December, January, February and March and winter (June, July and August. The rectal temperature (RT and respiration rate (RR were measured weekly at 9AM and 3 and 9PM, in each season, in 50% of the animals randomly selected and sorted in four groups based on their milk production. The averages of T and the temperature and humidity index (THI were higher in the summer (25.6ºC e 75.8 than in the winter (19.0ºC e 65.3, while the RH were the same in both seasons (80.0%. The averages of RT and RR were always higher in the summer and at 3PM when compared to 9AM RT and RR (39.47ºC and 64.76 mov/min vs 38.89ºC and 44.21 mov/min. Gestation rate for milking cows was smaller in summer than in the winter. Conversely 85.4% of heifers became pregnant during the summer and 78.5% during the winter season.

Spring Soil Temperature Anomalies over Tibetan Plateau and Summer Droughts/Floods in East Asia

Science.gov (United States)

Xue, Y.; Li, W.; LI, Q.; Diallo, I.; Chu, P. C.; Guo, W.; Fu, C.

2017-12-01

Recurrent extreme climate events, such as droughts and floods, are important features of the climate of East Asia, especially over the Yangtze River basin. Many studies have attributed these episodes to variability and anomaly of global sea surface temperatures (SST) anomaly. In addition, snow in the Tibetan Plateau has also been considered as one of the factors affecting the Asian monsoon variability. However, studies have consistently shown that SST along is unable to explain the extreme climate events fully and snow has difficulty to use as a predictor. Remote effects of observed large-scale land surface temperature (LST) and subsurface temperature variability in Tibetan Plateau (TP) on East Asian regional droughts/floods, however, have been largely ignored. We conjecture that a temporally filtered response to snow anomalies may be preserved in the LST anomaly. In this study, evidence from climate observations and model simulations addresses the LST/SUBT effects. The Maximum Covariance Analysis (MCA) of observational data identifies that a pronounce spring LST anomaly pattern over TP is closely associated with precipitation anomalies in East Asia with a dipole pattern, i.e., negative/positive TP spring LST anomaly is associated with the summer drought/flood over the region south of the Yangtze River and wet/dry conditions to the north of the Yangtze River. Climate models were used to demonstrate a causal relationship between spring cold LST anomaly in the TP and the severe 2003 drought over the southern part of the Yangtze River in eastern Asia. This severe drought resulted in 100 x 106 kg crop yield losses and an economic loss of 5.8 billion Chinese Yuan. The modeling study suggests that the LST effect produced about 58% of observed precipitation deficit; while the SST effect produced about 32% of the drought conditions. Meanwhile, the LST and SST effects also simulated the observed flood over to the north of the Yangtze River. This suggests that inclusion of

Seasonal variation in orthopedic health services utilization in Switzerland: the impact of winter sport tourism.

Science.gov (United States)

Matter-Walstra, Klazien; Widmer, Marcel; Busato, André

2006-03-03

Climate- or holiday-related seasonality in hospital admission rates is well known for many diseases. However, little research has addressed the impact of tourism on seasonality in admission rates. We therefore investigated the influence of tourism on emergency admission rates in Switzerland, where winter and summer leisure sport activities in large mountain regions can generate orthopedic injuries. Using small area analysis, orthopedic hospital service areas (HSAo) were evaluated for seasonality in emergency admission rates. Winter sport areas were defined using guest bed accommodation rate patterns of guest houses and hotels located above 1000 meters altitude that show clear winter and summer peak seasons. Emergency admissions (years 2000-2002, n = 135'460) of local and nonlocal HSAo residents were evaluated. HSAo were grouped according to their area type (regular or winter sport area) and monthly analyses of admission rates were performed. Of HSAo within the defined winter sport areas 70.8% show a seasonal, summer-winter peak hospital admission rate pattern and only 1 HSAo outside the defined winter sport areas shows such a pattern. Seasonal hospital admission rates in HSAo in winter sport areas can be up to 4 times higher in winter than the intermediate seasons, and they are almost entirely due to admissions of nonlocal residents. These nonlocal residents are in general -and especially in winter- younger than local residents, and nonlocal residents have a shorter length of stay in winter sport than in regular areas. The overall geographic distribution of nonlocal residents admitted for emergencies shows highest rates during the winter as well as the summer in the winter sport areas. Small area analysis using orthopedic hospital service areas is a reliable method for the evaluation of seasonality in hospital admission rates. In Switzerland, HSAo defined as winter sport areas show a clear seasonal fluctuation in admission rates of only nonlocal residents, whereas

A Prospective Longitudinal Study of Seasonality in African Students Living in the Greater Washington, D.C. Metropolitan Area

Directory of Open Access Journals (Sweden)

Alvaro Guzman

2007-01-01

Full Text Available We conducted a prospective, longitudinal study of seasonality in a vulnerable population, i.e., African students who migrated to a temperate climate. Consistent with previous cross-sectional studies, we hypothesized lower mood and energy, and higher appetite and weight, in fall/winter than in spring/summer. Four cohorts of African students attending a year-long nursing school program without vacation in Washington, D.C., were assessed monthly for 1 year. Forty-three subjects (mean age = 33.46 ± 6.25, consisting of predominantly females (76.7%, completed the study. The cohorts began their academic program in different seasons (one each in winter, spring, summer, and fall, inherently minimizing confounding influences on seasonality, such as academic and immigration stress, as well as allowing adjustment for an order effect. At each assessment, students completed three 100-mm visual analog scales for mood, energy, and appetite, and were weighed on a digital scale. For each standardized dependent variable, a repeated measure ANOVA was used and, if a significant effect of month was identified, averages for spring/summer and fall/winter were compared using paired ttests. In addition, a mixed model for repeated measures was applied to raw (nonstandardized data. Body weight was significantly higher in fall/winter than in spring/summer (p < 0.01. No seasonal differences in mood, energy, or appetite were found. Benefiting from certain unique features of our cohorts allowing adjustment for order effects, this is the first study to identify a seasonal variation in body weight with a peak in winter using longitudinal monthly measurements.

Spatio-temporal variation of precipitation in the Three-River Headwater Region from 1961 to 2010

Institute of Scientific and Technical Information of China (English)

YI Xiangsheng; LI Guosheng; YIN Yanyu

2013-01-01

Based on a monthly dataset of precipitation time series (1961-2010) from 12 meteorological stations across the Three-River Headwater Region (THRHR) of Qinghai Province,China,the spatio-temporal variation and abrupt change analysis of precipitation were examined by using moving average,linear regression,spline interpolation,the Mann-Kendall test and so on.Major conclusions were as follows.(1) The long-term annual and seasonal precipitation in the study area indicated an increasing trend with some oscillations during 1961-2010; however,the summer precipitation in the Lantsang (Lancang) River Headwater Region (LARHR),and the autumn precipitation in the Yangtze River Headwater Region (YERHR) of the THRHR decreased in the same period.(2) The amount of annual precipitation in the THRHR and its three sub-headwater regions was greater in the 1980s and 2000s.The springs were fairly wet after the 1970s,while the summers were relatively wet in the 1960s,1980s and 2000s.In addition,the amount of precipitation in the autumn was greater in the 1970s and 1980s,but it was relatively less for the winter precipitation,except in the 1990s.(3) The normal values of spring,summer,winter and annual precipitation in the THRHR and its three sub-headwater regions all increased,but the normal value of summer precipitation in the LARHR had a negative trend and the normal value of winter precipitation declined in general.(4) The spring and winter precipitation increased in most of the THRHR.The summer,autumn and annual precipitation increased mainly in the marginal area of the west and north and decreased in the regions of Yushu,Zaduo,Jiuzhi and Banma.(5) The spring and winter precipitation in the THRHR and its three sub-headwater regions showed an abrupt change,except for the spring precipitation in the YARHR.The abrupt changes of spring precipitation were mainly in the late 1980s and early 1990s,while the abrupt changes of winter precipitation were primary in the mid-to late 1970s

The 2010 spring drought reduced primary productivity in southwestern China

International Nuclear Information System (INIS)

Zhang Li; Li Jing; Xiao Jingfeng; Wang Kun; Lei Liping; Guo Huadong

2012-01-01

Many parts of the world experience frequent and severe droughts. Summer drought can significantly reduce primary productivity and carbon sequestration capacity. The impacts of spring droughts, however, have received much less attention. A severe and sustained spring drought occurred in southwestern China in 2010. Here we examine the influence of this spring drought on the primary productivity of terrestrial ecosystems using data on climate, vegetation greenness and productivity. We first assess the spatial extent, duration and severity of the drought using precipitation data and the Palmer drought severity index. We then examine the impacts of the drought on terrestrial ecosystems using satellite data for the period 2000–2010. Our results show that the spring drought substantially reduced the enhanced vegetation index (EVI) and gross primary productivity (GPP) during spring 2010 (March–May). Both EVI and GPP also substantially declined in the summer and did not fully recover from the drought stress until August. The drought reduced regional annual GPP and net primary productivity (NPP) in 2010 by 65 and 46 Tg C yr −1 , respectively. Both annual GPP and NPP in 2010 were the lowest over the period 2000–2010. The negative effects of the drought on annual primary productivity were partly offset by the remarkably high productivity in August and September caused by the exceptionally wet conditions in late summer and early fall and the farming practices adopted to mitigate drought effects. Our results show that, like summer droughts, spring droughts can also have significant impacts on vegetation productivity and terrestrial carbon cycling. (letter)

Research note: the performance of spring- and summer-reared broilers as affected by precision beak trimming at seven days of age.

Science.gov (United States)

Christmas, R B

1993-12-01

In each of two duplicate trials approximately 2,500 day-old Peterson x Arbor Acres straight-run broiler chicks were equally divided between two treatments of three pens each. Treatment 1 was maintained as controls (C), and Treatment 2 birds were precision beak-trimmed (PBT) at 7 days of age. Feed and water were supplied for ad libitum consumption to both groups. Trials 1 and 2 were initiated in March and June, respectively. Performance of spring-reared broilers were comparable regardless of beak trimming procedure, except that PBT broilers experienced slightly higher mortality after PBT. Final body weights of the summer-reared broilers were 15% lower than those reared in the spring. Additionally, PBT resulted in significantly reduced final body weights and feed intake. There were no significant differences in mortality or feed conversion due to PBT.

Indoor PAHs at schools, homes and offices in Rome, Italy

Science.gov (United States)

Romagnoli, P.; Balducci, C.; Perilli, M.; Gherardi, M.; Gordiani, A.; Gariazzo, C.; Gatto, M. P.; Cecinato, A.

2014-08-01

Indoor and outdoor concentrations of polycyclic aromatic hydrocarbons (PAHs) associated with PM2.5 particles were monitored in three microenvironments (schools, homes and offices) in the city of Rome, Italy, between winter 2011 and summer 2012. Molecular signatures and indoor/outdoor concentration ratios of PAHs were investigated, with special emphasis on carcinogenic congeners. At indoor locations, total PAHs ranged, on average, from 1.8 to 8.4 ng/m3 in winter and from 0.30 to 1.35 ng/m3 in spring/summer. Outdoors, total PAH concentrations were found to reach 6.3-17.9 ng/m3 in winter and 0.42-1.74 ng/m3 in spring-summer. Indoors, the concentration of benzo[a]pyrene (BaP) was as high as 1.1 ng/m3 in winter and below 0.1 ng/m3 in the warm season, independently of site type; the yearly average remained below the European guideline value. The indoor/outdoor concentration ratios of individual compounds were lower than one for most of congeners, suggesting that outdoor sources were predominant. Nonetheless, the percentages of PAH compounds changed with sites and seasons; in particular, in spring/summer, the concentration of BaP at our sites was more than twice that recorded at the regional network stations.

Sources and Potential Photochemical Roles of Formaldehyde in an Urban Atmosphere in South China

Science.gov (United States)

Wang, Chuan; Huang, Xiao-Feng; Han, Yu; Zhu, Bo; He, Ling-Yan

2017-11-01

Formaldehyde (HCHO) is an important intermediate in tropospheric photochemistry. However, study of its evolution characteristics under heavy pollution conditions in China is limited, especially for high temporal resolutions, making it difficult to analyze its sources and environmental impacts. In this study, ambient levels of HCHO were monitored using a proton-transfer reaction mass spectrometer at an urban site in the Pearl River Delta of China. Continuous monitoring campaigns were conducted in the spring, summer, fall, and winter in 2016. The highest averaged HCHO concentrations were observed in autumn (5.1 ± 3.1 ppbv) and summer (5.0 ± 4.4 ppbv), followed by winter (4.2 ± 2.2 ppbv) and spring (3.4 ± 1.6 ppbv). The daily maximum of HCHO occurs in the early afternoon and shows good correlations with O3 and the secondary organic aerosol tracer during the day, revealing close relationships between ambient HCHO and secondary formations in Shenzhen, especially in summer and autumn. The daytime HCHO is estimated to be the major contributor to O3 formation and OH radical production, indicating that HCHO plays a key role in the urban atmospheric photochemical reactions. Anthropogenic secondary formation was calculated to be the dominant source of HCHO using a photochemical age-based parameterization method, with an average proportion of 39%. The contributions of biogenic sources in summer (41%) and autumn (39%) are much higher than those in spring (26%) and winter (28%), while the contributions of anthropogenic primary sources in spring (20%) and winter (18%) are twice those in summer (9%) and autumn (9%).

Temporal patterns in Homalodisca spp. (Hemiptera: Cicadellidae) oviposition on southern California citrus and jojoba.

Science.gov (United States)

Al-Wahaibi, Ali K; Morse, Joseph G

2010-02-01

A detailed study of the distribution of egg masses of Homalodisca vitripennis (Germar) and H. liturata Ball was done across a 2-yr period (2001-2003) on six host plants in southern California (Marsh grapefruit, Lisbon lemon, Washington navel, Dancy tangerine, rough lemon, and jojoba in Riverside; jojoba in Desert Center). The majority of egg masses in Riverside belonged to H. vitripennis (84-100%), whereas in Desert Center, all Homalodisca egg masses were H. liturata. Oviposition in Riverside occurred in two discrete periods, a late winter and spring period (mid-February to late May), followed by a short interval of very low oviposition during most of June, and then a summer period (late June to late September) followed by a relatively long period of very low oviposition in fall and early winter (October to mid-February). Levels of oviposition during the late winter-spring period were similar to those during the summer despite an observed larger population of adults during the latter period. Moreover, egg clutch size for H. vitripennis was generally greater in spring than during summer and was generally higher than that for H. liturata, especially on Riverside jojoba. Larger egg clutch size was seen on grapefruit than on lemon, navel, and tangerine during summer. There appeared to be temporal host shifts in oviposition; most evident was the shift from relatively high rates of oviposition on lemon and tangerine in late winter-early spring to relatively higher rates of oviposition on grapefruit and navel during summer.

Atmospheric components of the surface energy budget over young sea ice: Results from the N-ICE2015 campaign

Science.gov (United States)

Walden, Von P.; Hudson, Stephen R.; Cohen, Lana; Murphy, Sarah Y.; Granskog, Mats A.

2017-08-01

The Norwegian young sea ice campaign obtained the first measurements of the surface energy budget over young, thin Arctic sea ice through the seasonal transition from winter to summer. This campaign was the first of its kind in the North Atlantic sector of the Arctic. This study describes the atmospheric and surface conditions and the radiative and turbulent heat fluxes over young, thin sea ice. The shortwave albedo of the snow surface ranged from about 0.85 in winter to 0.72-0.80 in early summer. The near-surface atmosphere was typically stable in winter, unstable in spring, and near neutral in summer once the surface skin temperature reached 0°C. The daily average radiative and turbulent heat fluxes typically sum to negative values (-40 to 0 W m-2) in winter but then transition toward positive values of up to nearly +60 W m-2 as solar radiation contributes significantly to the surface energy budget. The sensible heat flux typically ranges from +20-30 W m-2 in winter (into the surface) to negative values between 0 and -20 W m-2 in spring and summer. A winter case study highlights the significant effect of synoptic storms and demonstrates the complex interplay of wind, clouds, and heat and moisture advection on the surface energy components over sea ice in winter. A spring case study contrasts a rare period of 24 h of clear-sky conditions with typical overcast conditions and highlights the impact of clouds on the surface radiation and energy budgets over young, thin sea ice.

Enhanced growth of Juniperus thurifera under a warmer climate is explained by a positive carbon gain under cold and drought.

Science.gov (United States)

Gimeno, Teresa E; Camarero, J Julio; Granda, Elena; Pías, Beatriz; Valladares, Fernando

2012-03-01

Juniperus thurifera L. is an endemic conifer of the western Mediterranean Basin where it is subjected to a severe climatic stress characterized by low winter temperatures and summer drought. Given the trend of increased warming-induced drought stress in this area and the climatic sensitivity of this species, we expect a negative impact of climate change on growth and ecophysiological performance of J. thurifera in the harsh environments where it dominates. To evaluate this, we measured long- and short-term radial growth using dendrochronology, photosynthesis and water-use efficiency in males, females and juveniles in three sites in Central Spain. Climate was monitored and completed with historical records. Mean annual temperature has increased +0.2 °C per decade in the study area, and the main warming trends corresponded to spring (+0.2 °C per decade) and summer (+0.3 °C per decade). Radial growth and maximum photosynthesis peaked in spring and autumn. Positive photosynthetic rates were maintained all year long, albeit at reduced rates in winter and summer. Radial growth was enhanced by wet conditions in the previous autumn and by warm springs and high precipitation in summer of the year of tree-ring formation. Cloud cover during the summer increased growth, while cloudy winters led to impaired carbon gain and reduced growth in the long term. We argue that maintenance of carbon gain under harsh conditions (low winter temperatures and dry summer months) and plastic xylogenesis underlie J. thurifera's ability to profit from changing climatic conditions such as earlier spring onset and erratic summer rainfall. Our results highlight that not only the magnitude but also the sign of the impact of climate change on growth and persistence of Mediterranean trees is species specific.

Spring in the boreal environment: observations on pre- and post-melt energy and CO{sub 2} fluxes in two central Siberian ecosystems

Energy Technology Data Exchange (ETDEWEB)

Arneth, A. [Dept. of Physical Geography and Ecosystems Analysis, Lund Univ., Lund (Sweden); Lloyd, J. [Scool of Geography, Leeds Univ., Leeds (United Kingdom); Shibistova, O. [V.N. Sukachev Forest Inst., Akademgorodok, Krasnoyarsk (Russian Federation); Sogachev, A. [Dept. of Physical Sciences, Helsinki Univ. (Finland); Kolle, O. [Max Planck Inst. for Biogeochemistry, Jena (Germany)

2006-07-01

A range of observations points towards earlier onset of spring in northern high latitudes. However, despite the profound effects this may have on vegetation-atmosphere exchange of carbon (NEE), vegetation-atmosphere physical coupling, or the location of the tundra-taiga interface, the number of studies that investigate winter-spring transition fluxes in contrasting northern vegetation types is limited. Here, we examine spring ecosystem-atmosphere energy and carbon exchange in a Siberian pine forest and mire. Divergent surface albedo before and during snow-melt resulted in daytime net radiation (R{sub n}) above the forest exceeding R{sub n} above the mire by up to 10 MJ m{sup -2}. Until stomata could open, absorbed radiation by the green pine canopy caused substantial daytime sensible heat fluxes (H > 10MJ m{sup -2}). H above the mire was very low, even negative (< -2 MJ m{sup -2}), during that same period. Physiological activity in both ecosystems responded rapidly to warming temperatures and snow-melt, which is essential for survival in Siberia with its very short summers. On days with above-zero temperatures, before melt was complete, low rates of forest photosynthesis (1-2 {mu}mol m{sup -2} s{sup -1}) were discernible. Forest and mire NEE became negative the same day, or shortly after, photosynthesis commenced. The mire lagged by about two weeks behind the forest and regained its full carbon uptake capacity at a slower rate. Our data provide empirical evidence for the importance the timing of spring and the relative proportion of forest vs. mire has for late winter/spring boundary-layer growth, and production and surface-atmosphere mixing of trace gases. Models that seek to investigate effects of increasingly earlier spring in high latitudes must correctly account for contrasting physical and biogeochemical ecosystem-atmosphere exchange in heterogeneous landscapes. (orig.)

Beneficial effect of hot spring bathing on stress levels in Japanese macaques.

Science.gov (United States)

Takeshita, Rafaela S C; Bercovitch, Fred B; Kinoshita, Kodzue; Huffman, Michael A

2018-05-01

The ability of animals to survive dramatic climates depends on their physiology, morphology and behaviour, but is often influenced by the configuration of their habitat. Along with autonomic responses, thermoregulatory behaviours, including postural adjustments, social aggregation, and use of trees for shelter, help individuals maintain homeostasis across climate variations. Japanese macaques (Macaca fuscata) are the world's most northerly species of nonhuman primates and have adapted to extremely cold environments. Given that thermoregulatory stress can increase glucocorticoid concentrations in primates, we hypothesized that by using an available hot spring, Japanese macaques could gain protection against weather-induced cold stress during winter. We studied 12 adult female Japanese macaques living in Jigokudani Monkey Park, Japan, during the spring birth season (April to June) and winter mating season (October to December). We collected faecal samples for determination of faecal glucocorticoid (fGC) metabolite concentrations by enzyme immunoassay, as well as behavioural data to determine time spent in the hot springs, dominance rank, aggression rates, and affiliative behaviours. We used nonparametric statistics to examine seasonal changes in hot spring bathing, and the relationship between rank and air temperature on hot spring bathing. We used general linear mixed-effect models to examine factors impacting hormone concentrations. We found that Japanese macaques use hot spring bathing for thermoregulation during the winter. In the studied troop, the single hot spring is a restricted resource favoured by dominant females. High social rank had both costs and benefits: dominant females sustained high fGC levels, which were associated with high aggression rates in winter, but benefited by priority of access to the hot spring, which was associated with low fGC concentrations and therefore might help reduce energy expenditure and subsequent body heat loss. This unique

Turbulence influence on urban air pollution in a hot spot in Madrid: comparison of winter and summer field campaigns

Science.gov (United States)

Yagüe, Carlos; Román-Cascón, Carlos; Sastre, Mariano; Maqueda, Gregorio; Arrillaga, Jon A.; Artiñano, Begoña; Díaz-Ramiro, Elías; Gómez-Moreno, Francisco J.; Borge, Rafael; Narros, Adolfo; Pérez, Javier; Quaassdorff, Christina

2017-04-01

Air pollution is a major problem in the city of Madrid during weak synoptic forcing, since the presence of atmospheric stability conditions often develops night surface-based thermal inversions and subsidence inversions during daytime for several consecutive days, reaching high levels of NOx and Particulate Matter (PM) concentration. In this context, the TECNAIRE-CM (Innovative technologies for the assessment and improvement of urban air quality) research project has developed two field campaigns along 2015 (winter and summer) in a hot spot in the city of Madrid (Fernández Ladreda square). This hot spot includes one important intersection of different streets and also the start of the A42 motorway, which crosses down the square through a tunnel of about 150 m length. Besides, the location has numerous traffic lights and a lot of pedestrians walking in the vicinity. In addition to direct measurements related to air quality, data from different meteorological variables were recorded in order to characterize the atmospheric conditions. Moreover, two sonic anemometers where deployed to carry out a micrometeorological assessment of physical processes that take place in the urban atmospheric surface layer (TKE, friction velocity and sensible heat flux were evaluated). The evolution of the turbulence will be analyzed and compared for both campaigns (winter and summer), searching for the key seasonal differences as well as the importance of the different scales influencing the diffusion of pollutants (from multi resolution flux decomposition -MRFD- analysis). Specific case studies corresponding to high levels of pollution will be studied in detailed, to understand local pollution dynamics under the influence of both high traffic density and low turbulence situations. This work has been financed by Madrid Regional Research Plan through TECNAIRE (P2013/MAE-2972).

Five Year Mean Surface Chlorophyll Estimates in the Northern Gulf of Mexico for 2005 through 2009

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These images were created by combining the mean surface chlorophyll estimates to produce seasonal representations for winter, spring, summer and fall. Winter...

Basin-scale seasonal changes in marine free-living bacterioplankton community in the Ofunato Bay

KAUST Repository

Reza, Md. Shaheed

2018-04-26

The Ofunato Bay in the northeastern Pacific Ocean area of Japan possesses the highest biodiversity of marine organisms in the world and has attracted much attention due to its economic and environmental importance. We report here a shotgun metagenomic analysis of the year-round variation in free-living bacterioplankton collected across the entire length of the bay. Phylogenetic differences among spring, summer, autumn and winter bacterioplankton suggested that members of Proteobacteria tended to decrease at high water temperatures and increase at low temperatures. It was revealed that Candidatus Pelagibacter varied seasonally, reaching as much as 60% of all sequences at the genus level in the surface waters during winter. This increase was more evident in the deeper waters, where they reached up to 75%. The relative abundance of Planktomarina also rose during winter and fell during summer. A significant component of the winter bacterioplankton community was Archaea (mainly represented by Nitrosopumilus), as their relative abundance was very low during spring and summer but high during winter. In contrast, Actinobacteria and Cyanobacteria appeared to be higher in abundance during high-temperature periods. It was also revealed that Bacteroidetes constituted a significant component of the summer bacterioplankton community, being the second largest bacterial phylum detected in the Ofunato Bay. Its members, notably Polaribacter and Flavobacterium, were found to be high in abundance during spring and summer, particularly in the surface waters. Principal component analysis and hierarchal clustering analyses showed that the bacterial communities in the Ofunato Bay changed seasonally, likely caused by the levels of organic matter, which would be deeply mixed with surface runoff in the winter.

Reflectance spectroscopy of indoor settled dust in Tel Aviv, Israel: comparison between the spring and the summer seasons

Directory of Open Access Journals (Sweden)

A. A. Chudnovsky

2007-07-01

Full Text Available The influence of mineral and anthropogenic dust components on the VIS-NIR-SWIR spectral reflectance of artificial laboratory dust mixtures was evaluated and used in combination with Partial Least Squares (PLS regression to construct a model that correlates the dust content with its reflectance. Small amounts of dust (0.018–0.33 mg/cm² were collected using glass traps placed in different indoor environments in Tel Aviv, Israel during the spring and summer of 2005. The constructed model was applied to reflectance spectroscopy measurements derived from the field dust samples to assess their mineral content. Additionally, field samples were examined using Principal Component Analysis (PCA to identify the most representative spectral pattern for each season. Across the visible range of spectra two main spectral shapes were observed, convex and concave, though spectra exhibiting hybrid shapes were also seen. Spectra derived from spring season dust samples were characterized mostly by a convex shape, which indicates a high mineral content. In contrast, the spectra generated from summer samples were characterized generally by a concave shape, which indicates a high organic matter content. In addition to this seasonal variation in spectral patterns, spectral differences were observed associated with the dwelling position in the city. Samples collected in the city center showed higher organic content, whereas samples taken from locations at the city margins, near the sea and next to open areas, exhibited higher mineral content. We conclude that mineral components originating in the outdoor environment influence indoor dust loads, even when considering relatively small amounts of indoor settled dust. The sensitive spectral-based method developed here has potentially many applications for environmental researchers and policy makers concerned with dust pollution.

Lyons Ferry Hatchery - Summer Steelhead, Final Report

International Nuclear Information System (INIS)

Watson, M.

1996-05-01

This report presents the findings of the independent audit of the Lyons Ferry Hatchery (Summer Steelhead). Lyons Ferry Hatchery is located downstream of the confluence of the Palouse and Snake rivers, about 7 miles west of Starbuck, Washington. The hatchery is used for adult collection of fall chinook and summer steelhead, egg incubation of fall chinook, spring chinook, steelhead, and rainbow trout and rearing of fall chinook, spring chinook, summer steelhead, and rainbow trout. The audit was conducted in April 1996 as part of a two-year effort that will include 67 hatcheries and satellite facilities located on the Columbia and Snake River system in Idaho, Oregon, and Washington. The hatchery operating agencies include the US Fish and Wildlife Service, Idaho Department of Fish and Game, Oregon Department of Fish and Wildlife, and Washington Department of Fish and Wildlife

Nitrous oxide and methane emissions from optimized and alternative cereal cropping systems on the North China Plain: A two-year field study

International Nuclear Information System (INIS)

Gao, Bing; Ju, Xiaotang; Su, Fang; Meng, Qingfeng; Oenema, Oene; Christie, Peter; Chen, Xinping; Zhang, Fusuo

2014-01-01

The impacts of different crop rotation systems with their corresponding management practices on grain yield, greenhouse gas emissions, and fertilizer nitrogen (N) and irrigation water use efficiencies are not well documented. This holds especially for the North China Plain which provides the staple food for hundreds of millions of people and where groundwater resources are polluted with nitrate and depleted through irrigation. Here, we report on fertilizer N and irrigation water use, grain yields, and nitrous oxide (N 2 O) and methane (CH 4 ) emissions of conventional and optimized winter wheat–summer maize double-cropping systems, and of three alternative cropping systems, namely a winter wheat–summer maize (or soybean)–spring maize system, with three harvests in two years; and a single spring maize system with one crop per year. The results of this two-year study show that the optimized double-cropping system led to a significant increase in grain yields and a significant decrease in fertilizer N use and net greenhouse gas intensity, but the net greenhouse gas N 2 O emissions plus CH 4 uptake and the use of irrigation water did not decrease relative to the conventional system. Compared to the conventional system the net greenhouse gas emissions, net greenhouse gas intensity and use of fertilizer N and irrigation water decreased in the three alternative cropping systems, but at the cost of grain yields except in the winter wheat–summer maize–spring maize system. Net uptake of CH 4 by the soil was little affected by cropping system. Average N 2 O emission factors were only 0.17% for winter wheat and 0.53% for maize. In conclusion, the winter wheat–summer maize–spring maize system has considerable potential to decrease water and N use and decrease N 2 O emissions while maintaining high grain yields and sustainable use of groundwater. - Highlights: • Yields, resource use efficiency and N 2 O + CH 4 emission differ among cropping systems. • An

Nitrous oxide and methane emissions from optimized and alternative cereal cropping systems on the North China Plain: A two-year field study

Energy Technology Data Exchange (ETDEWEB)

Gao, Bing [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Ju, Xiaotang, E-mail: juxt@cau.edu.cn [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Su, Fang; Meng, Qingfeng [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Oenema, Oene [Wageningen University and Research, Alterra, Wageningen (Netherlands); Christie, Peter [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Agri-Environment Branch, Agri-Food and Biosciences Institute, Belfast BT9 5PX (United Kingdom); Chen, Xinping; Zhang, Fusuo [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China)

2014-02-01

The impacts of different crop rotation systems with their corresponding management practices on grain yield, greenhouse gas emissions, and fertilizer nitrogen (N) and irrigation water use efficiencies are not well documented. This holds especially for the North China Plain which provides the staple food for hundreds of millions of people and where groundwater resources are polluted with nitrate and depleted through irrigation. Here, we report on fertilizer N and irrigation water use, grain yields, and nitrous oxide (N{sub 2}O) and methane (CH{sub 4}) emissions of conventional and optimized winter wheat–summer maize double-cropping systems, and of three alternative cropping systems, namely a winter wheat–summer maize (or soybean)–spring maize system, with three harvests in two years; and a single spring maize system with one crop per year. The results of this two-year study show that the optimized double-cropping system led to a significant increase in grain yields and a significant decrease in fertilizer N use and net greenhouse gas intensity, but the net greenhouse gas N{sub 2}O emissions plus CH{sub 4} uptake and the use of irrigation water did not decrease relative to the conventional system. Compared to the conventional system the net greenhouse gas emissions, net greenhouse gas intensity and use of fertilizer N and irrigation water decreased in the three alternative cropping systems, but at the cost of grain yields except in the winter wheat–summer maize–spring maize system. Net uptake of CH{sub 4} by the soil was little affected by cropping system. Average N{sub 2}O emission factors were only 0.17% for winter wheat and 0.53% for maize. In conclusion, the winter wheat–summer maize–spring maize system has considerable potential to decrease water and N use and decrease N{sub 2}O emissions while maintaining high grain yields and sustainable use of groundwater. - Highlights: • Yields, resource use efficiency and N{sub 2}O + CH{sub 4} emission

Seasonal evolution of cholorophyll-a and cyanobacteria (Prochlorococcus and Synechococcus on the northeast continental shelf of the Gulf of Cádiz: relation to thermohaline and nutrients fields

Directory of Open Access Journals (Sweden)

Eleonora Anfuso

2013-01-01

Full Text Available The seasonal evolution of nutrients, chlorophyll-a (chl-a and cyanobacteria (Synechococcus and Prochlorococcus on the northeast continental shelf of the Gulf of Cádiz was observed during four cruises in summer and autumn 2006 and winter and spring 2007. Samples were collected to determine the distribution of chl-a and cyanobacteria abundance and to analyse their coupling with thermohaline and chemical properties in the gulf region. Surface nutrient distributions showed clear seasonal variability. Maximum levels were recorded for the entire study region during winter due to winter mixing and the strong influence of the Guadalquivir River and Bay of Cádiz outflow. Maximum chl-a levels were reached during spring for the entire region and for the entire water column. Minimum values of chl-a were observed during summer, under prevailing oligotrophic conditions, and winter when in spite of relatively high nutrient concentrations, phytoplankton growth was probably light-limited. The distribution of both cyanobacteria populations also varied seasonally in association with the oceanographic conditions. Prochlorococcus maximum cell abundance was observed at the sea surface during the four cruises, except in the northern region during summer. However, Synechococcus showed a maximum concentration at the sea surface in autumn and winter and at the subsurface chlorophyll maximum in autumn and spring.

Seasonal and daily fluctuation of diatoms during spring tide periods in Kerkennah Islands

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Mounir Ben brahim

2015-06-01

Full Text Available Objective: To study seasonal and the daily distribution of diatoms in the three tidal periods (flood, slack and ebb period during the spring tide. Methods: Water samples were taken and environmental variables were measured three times in each tidal period during 10 days of spring tide. Sampling was done in 2007 in Cercina station located in the western coast of Kerkennah (34°41'27'' N; 11°07'45'' E (Southern Tunisia. Results: Nutrients showed significant variation between seasons, increasing in spring and decreasing noticeably in autumn and winter. About 36 diatom species were found. Results revealed a remarkable abundance increase in spring and summer. Irregular differences in diatom abundances were revealed over the tidal periods, with the highest rates being detected during the flood and the ebb period, while the abundance rate was lowest during the slack period. This could presumably be attributed to the increase of nutrient supply of suspended particulate matter during water motion. The results revealed a correlation between diatom abundance and temperature, NO2 - , NO3 - , Si(OH4 and PO4 3 . Temperature seemed to be the most important factors which may influence the distribution and diatom abundance. Conclusions: Tide has various effects on the nutrients status and diatoms community (in terms of species composition, succession and abundance between different tidal periods. Fluctuation of diatoms was correlated with changes in the circulation of water bodies and changes in nutrient regime.

Studies on the antifertility potentiality of Hibiscus rosa sinensis. Parts of medicinal value; selection of species and seasonal variations.

Science.gov (United States)

Kholkute, S D; Mudgal, V; Udupa, K N

1977-02-01

The postcoital antifertility properties of benzene hot extracts of Hibiscus rosa sinensis flowers, leaves, and stembarks, collected during the winter, spring, rainy, and summer seasons, were investigated in female rats. Only extracts from the flowers of the plant were 100% effective in preventing pregnancy. Those flowers collected during the winter showed the greatest potency, followed by those collected in the spring, rainy season, and summer, in decreasing order. Benzene extracts of flowers collected from Hibiscus mutabilis, Hibiscus schizopetalus, and Malvasicus grandiflorus, plants resembling Hibiscus rosa sinensis in petaloid structure, did not markedly affect pregnancy.

The Penalty of a Long, Hot Summer. Photosynthetic Acclimation to High CO2 and Continuous Light in “Living Fossil” Conifers1

Science.gov (United States)

Osborne, Colin P.; Beerling, David J.

2003-01-01

Deciduous forests covered the ice-free polar regions 280 to 40 million years ago under warm “greenhouse” climates and high atmospheric pCO2. Their deciduous habit is frequently interpreted as an adaptation for minimizing carbon losses during winter, but experiments with “living fossils” in a simulated warm polar environment refute this explanation. Measured carbon losses through leaf abscission of deciduous trees are significantly greater than losses through winter respiration in evergreens, yet annual rates of primary productivity are similar in all species. Here, we investigate mechanisms underlying this apparent paradox by measuring the seasonal patterns of leaf photosynthesis (A) under pCO2 enrichment in the same trees. During spring, A increased significantly in coastal redwood (Sequoia sempervirens), dawn redwood (Metasequoia glyptostroboides), and swamp cypress (Taxodium distichum) at an elevated pCO2 of 80 Pa compared with controls at 40 Pa. However, strong acclimation in Rubisco carboxylation capacity (Vc,max) completely offset the CO2 response of A in all species by the end of 6 weeks of continuous illumination in the simulated polar summer. Further measurements demonstrated the temporary nature of acclimation, with increases in Vc,max during autumn restoring the CO2 sensitivity of A. Contrary to expectations, the acclimation of Vc,max was not always accompanied by accumulation of leaf carbohydrates, but was associated with a decline in leaf nitrogen in summer, suggesting an alteration of the balance in plant sources and sinks for carbon and nitrogen. Preliminary calculations using A indicated that winter carbon losses through deciduous leaf abscission and respiration were recovered by 10 to 25 d of canopy carbon fixation during summer, thereby explaining the productivity paradox. PMID:12972654

Effect of Severe Winter Cold on the Photosynthetic Potentials of Three Co-occurring Evergreen Woody Species in a Mediterranean Forest, Catalonia (Spain)

Science.gov (United States)

Sperlich, Dominik; Gracia, Carlos; Peñuelas, Josep; Sabaté, Santi

2013-04-01

Evergreen tree species in the Mediterranean region have to cope with a wide range of environmental stress conditions from summer drought to winter cold. The winter period can lead to photoinhibition due to a combination of high solar irradiances and chilling temperatures which can reduce the light saturation point. However, Mediterranean winter mildness can lead periodically to favourable environmental conditions above the threshold for positive carbon balance benefitting evergreen woody species in contrast to winter deciduous species. The advantage of being able to photosynthesis all year round with a significant fraction in the winter month is compensating for the lower photosynthetic potentials during spring and summer in comparison to deciduous species. In this work, we investigated the physiological behaviour of three evergreen tree species (Quercus ilex, Pinus halepensis, Arbutus undeo) co-occurring in a natural and mature Mediterranean forest after a period of mild winter conditions and their response to a sudden period of intense cold weather. Therefore, we examined in each period the photosynthetic potentials by estimating the maximum carboxylation rate (Vcmax) and the maximum electron transport rate (Jmax) through gas exchange measurements. The results indicate that all species exhibited extraordinary high photosynthetic potentials during the first period of measurement as a response to the mild conditions. However, the sudden cold period affected negatively the photosynthetic potentials of Quercus ilex and A. unedo with reduction ranging between 37 to 45 %, whereas they were observed to be only insignificantly reduced in Pinus halepensis. Our results can be explained by previous classifications into photoinhibition-avoiding (P. halpensis) and photoinhibition-tolerant (Q. ilex, A. undeo) species on the basis of their susceptibility to dynamic photoinhibition (Martinez Ferri 2000). Photoinhibition tolerant species are characterised with a more dynamic

Five Year Mean Sea-Surface Temperature in the Northern Gulf of Mexico for 2005 through 2009

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These images were created by combining the mean sea-surface temperature values to produce seasonal representations for winter, spring, summer and fall. Winter...

Trans-equatorial migration routes, staging sites and wintering areas of a high-Arctic avian predator: the long-tailed Skua (Stercorarius longicaudus).

Science.gov (United States)

Gilg, Olivier; Moe, Børge; Hanssen, Sveinn Are; Schmidt, Niels Martin; Sittler, Benoît; Hansen, Jannik; Reneerkens, Jeroen; Sabard, Brigitte; Chastel, Olivier; Moreau, Jérôme; Phillips, Richard A; Oudman, Thomas; Biersma, Elisabeth M; Fenstad, Anette A; Lang, Johannes; Bollache, Loïc

2013-01-01

The Long-tailed Skua, a small (summer, but little is known about its migration and winter distribution. We used light-level geolocators to track the annual movements of eight adult birds breeding in north-east Greenland (n = 3) and Svalbard (n = 5). All birds wintered in the Southern Hemisphere (mean arrival-departure dates on wintering grounds: 24 October-21 March): five along the south-west coast of Africa (0-40°S, 0-15°E), in the productive Benguela upwelling, and three further south (30-40°S, 0-50°E), in an area extending into the south-west Indian Ocean. Different migratory routes and rates of travel were documented during post-breeding (345 km d(-1) in late August-early September) and spring migrations (235 km d(-1) in late April) when most birds used a more westerly flyway. Among the different staging areas, a large region off the Grand Banks of Newfoundland appears to be the most important. It was used in autumn by all but one of the tracked birds (from a few days to three weeks) and in spring by five out of eight birds (from one to more than six weeks). Two other staging sites, off the Iberian coast and near the Azores, were used by two birds in spring for five to six weeks. Over one year, individuals travelled between 43,900 and 54,200 km (36,600-45,700 when excluding staging periods) and went as far as 10,500-13,700 km (mean 12,800 km) from their breeding sites. This study has revealed important marine areas in both the south and north Atlantic Ocean. Sustainable management of these ocean basins will benefit Long-tailed Skuas as well as other trans-equatorial migrants from the Arctic.

Seasonal alterations in host range and fidelity in the polyphagous mirid bug, Apolygus lucorum (Heteroptera: Miridae.

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Hongsheng Pan

Full Text Available In herbivorous insects, host plant switching is commonly observed and plays an important role in their annual life cycle. However, much remains to be learned about seasonal host switching of various pestiferous arthropods under natural conditions. From 2006 until 2012, we assessed Apolygus lucorum (Meyer-Dür host plant use in successive spring, summer and winter seasons at one single location (Langfang, China. Data were used to quantify changes in host plant breadth and host fidelity between seasons. Host fidelity of A. lucorum differed between seasons, with 87.9% of spring hosts also used in the summer and 36.1% of summer hosts used in winter. In contrast, as little as 25.6% host plant species were shared between winter and spring. Annual herbaceous plants are most often used for overwintering, while perennial woody plants are relatively important for initial population build-up in the spring. Our study contributes to an improved understanding of evolutionary interactions between A. lucorum and its host plants and lays the groundwork for the design of population management strategies for this important pest in myriad crops.

Seasonal Variations in Voluntary Intake and Apparent Digestibility of Forages in Goats Grazing on Introduced Pasture

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Zewei Sun

2014-06-01

Full Text Available The nutrient composition of pasture, voluntary intake and digestibility of diet ingested by goats grazing on an introduced Leymus chinensis pasture were measured across spring (May, summer (July, autumn (October and winter (March. In each season, 12 Inner Mongolian Cashmere goats (6 wethers and 6 does with an average live weight of 22.2±1.3 kg and 19.5±0.8 kg, respectively were used to graze on a 2 hectares size paddock. Diet selection was observed and the plant parts selected by grazing goats and whole plant L. chinensis were sampled simultaneously. The alkane pair C32:C33 and C36 were used to estimate intake and digestibility, respectively. The results showed that the plant parts selected by goats had higher crude protein (CP and lower acid detergent fiber (ADF and neutral detergent fiber (NDF than the whole plant, especially in the autumn and winter. The voluntary intake of dry matter (DM, CP, ADF, NDF, and metabolizable energy (ME by goats was highest in summer (p<0.05. The goats ingested more CP, ME, and less ADF in spring than in autumn (p<0.05. The intakes of DM, CP, and ME were lowest in winter (p<0.05. There were significant differences in nutrient intake between wethers and does in each season, except for the ADF and ME intake per metabolic weight (LW0.75. The nutrient digestibilities were higher in spring and summer, and decreased significantly during the autumn and winter (p<0.05. Goats, especially wethers, had a relative constant NDF digestibility across seasons, however, the apparent digestibility of CP in both wethers and does, decreased to negative values in winter. The grazing goats experienced relatively sufficient nutrients supply in spring and summer, and a severe deficiency of CP and ME in winter.

Energy Efficiency and Sustainability Evaluation of Space and Water Heating in Urban Residential Buildings of the Hot Summer and Cold Winter Zone in China

OpenAIRE

Xiao Chen; Yongquan Wen; Nanyang Li

2016-01-01

With the urbanization process of the hot summer and cold winter (HSCW) zone in China, the energy consumption of space and water heating in urban residential buildings of the HSCW zone has increased rapidly. This study presents the energy efficiency and sustainability evaluation of various ways of space and water heating taking 10 typical cities in the HSCW zone as research cases. Two indicators, primary energy efficiency (PEE) and sustainability index based on exergy efficiency, are adopted t...

Measured winter and spring-time indoor temperatures in UK homes over the period 1969–2010: A review and synthesis

International Nuclear Information System (INIS)

Vadodaria, K.; Loveday, D.L.; Haines, V.

2014-01-01

This paper presents a review and synthesis of average winter and spring-time indoor temperatures in UK homes measured over the period 1969–2010. Analysis of measured temperatures in a sample of solid wall dwellings in the UK, conducted as part of the CALEBRE research project, is included. The review suggests that, for periods when occupation was likely, there has been little or no increase in winter and spring-time average living room temperatures over the last 40 years, with average recorded living room temperatures having been historically lower than the WHO-recommended value of 21 °C. Correspondingly, for periods of likely occupation, average bedroom temperatures appear to have increased. Compared with non-domestic buildings, there have been fewer investigations of domestic thermal comfort, either in the UK or elsewhere, and hence the paper also calls for further detailed investigations of domestic indoor temperatures during occupied hours together with thermal comfort evaluations in order to better understand domestic thermal environments. Based on suggestions from the limited range of studies available to date, living room temperatures may need to be maintained within the range 20–22 °C for thermal satisfaction, though this requires confirmation through further research. The study also emphasises that improving the energy efficiency of homes should be the primary means to effect any increases in indoor temperatures that are deemed essential. Considerations for future policy are discussed. - Highlights: • We review indoor temperatures measured in UK homes during 1960-2010. • We present analysis of temperature recorded by our study in 20 UK homes. • Little or no increase observed in living room temperatures for the last 40 years. • Occupied bedroom temperatures appear to have increased. • Living room temperatures have been historically lower than the WHO guidelines

Five Year Mean Euphotic Depth in the Northern Gulf of Mexico for 2005 through 2009

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — These images were created by combining the mean euphotic depth estimates to produce seasonal representations for winter, spring, summer and fall. Winter includes the...

Five Year Mean Sea-surface Salinity in the Northern Gulf of Mexico for 2005 through 2009

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National Oceanic and Atmospheric Administration, Department of Commerce — These images were created by combining the mean sea-surface salinity values to produce seasonal representations for winter, spring, summer and fall. Winter includes...

Salt appetite is not increased in summer heat.

Science.gov (United States)

Leshem, Micah

2017-01-01

We tested the hypothesis that salt appetite increases in summer heat due to increased sodium loss due to increased drinking and perspiration. A test battery in the same sample of healthy young people tested in summer and winter revealed no seasonal differences in salt appetite (or fluid intake) despite a 10 °C rise in mean environmental temperature. Unexpectedly, sweet preference is reduced in summer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Migration and winter distribution of the Chestnutcollared Longspur

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Ellison Kevin

2017-12-01

Full Text Available The Chestnut-collared Longspur (Calcarius ornatus is one of five grassland songbirds, endemic within North America, with populations that have declined >65% since the 1960s. These species breed and winter in the northern and southern Great Plains, respectively. Identifying migration routes, wintering sites, and the timing of their habitat use is key for understanding the relative magnitude of threats across the annual cycle and effectively targeting habitats for conservation. We tracked migratory movements of seven Chestnut-collared Longspurs with light-level geolocators deployed in Canada. Individuals wintered up to 112-1,200km apart. All followed the Central Flyway, circumvented high-elevation terrain, and traveled east of the breeding location. Unlike most songbirds, the durations of spring and fall migrations were similar; on average 42 ± 7d and 41 ± 5d during fall and spring migrations, respectively, for an approximately 2,000km migration; this highlights the need to better understand habitat requirements during migration for grassland songbirds. Using geospatial habitat data, we assessed winter distribution overlap with four other endemic grassland songbirds; wintering range overlapped 63-99%. Future studies should use more precise devices (e.g., archival GPS units, programmed for data collection dates from this study, to identify specific migratory sites for better conserving this and associated grassland species.

Seasonal variations in groundwater upwelling zones in a Danish lowland stream analyzed using Distributed Temperature Sensing (DTS)

DEFF Research Database (Denmark)

Matheswaran, Karthikeyan; Blemmer, Morten; Rosbjerg, Dan

2014-01-01

–night temperature difference were applied to three DTS datasets representing stream temperature responses to the variable meteorological and hydrological conditions prevailing in summer, winter and spring. The standard deviation criterion was useful to identify groundwater discharge zones in summer and spring......-term deployment covering variable meteorological and hydrological scenarios. Copyright © 2012 John Wiley & Sons, Ltd....

Variational data assimilative modeling of the Gulf of Maine in spring and summer 2010

Science.gov (United States)

Li, Yizhen; He, Ruoying; Chen, Ke; McGillicuddy, Dennis J.

2015-05-01

A data assimilative ocean circulation model is used to hindcast the Gulf of Maine [GOM) circulation in spring and summer 2010. Using the recently developed incremental strong constraint 4D Variational data assimilation algorithm, the model assimilates satellite sea surface temperature and in situ temperature and salinity profiles measured by expendable bathythermograph, Argo floats, and shipboard CTD casts. Validation against independent observations shows that the model skill is significantly improved after data assimilation. The data-assimilative model hindcast reproduces the temporal and spatial evolution of the ocean state, showing that a sea level depression southwest of the Scotian Shelf played a critical role in shaping the gulf-wide circulation. Heat budget analysis further demonstrates that both advection and surface heat flux contribute to temperature variability. The estimated time scale for coastal water to travel from the Scotian Shelf to the Jordan Basin is around 60 days, which is consistent with previous estimates based on in situ observations. Our study highlights the importance of resolving upstream and offshore forcing conditions in predicting the coastal circulation in the GOM.

Winter ecology of the Porcupine caribou herd, Yukon: Part III, Role of day length in determining activity pattern and estimating percent lying

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D. E. Russell

1986-06-01

Full Text Available Data on the activity pattern, proportion of time spent lying and the length of active and lying periods in winter are presented from a 3 year study on the Porcupine caribou herd. Animals were most active at sunrise and sunset resulting in from one (late fall, early and mid winter to two (early fall and late winter to three (spring intervening lying periods. Mean active/lying cycle length decreased from late fall (298 mm to early winter (238 min, increased to a peak in mid winter (340 min then declined in late winter (305 min and again in spring (240 min. Mean length of the lying period increased throughout the 3 winter months from 56 min m early winter to 114 min in mid winter and 153 min in late winter. The percent of the day animals spent lying decreased from fall to early winter, increased throughout the winter and declined in spring. This pattern was related, in part, to day length and was used to compare percent lying among herds. The relationship is suggested to be a means of comparing quality of winter ranges.

Hibernating black bears (Ursus americanus) experience skeletal muscle protein balance during winter anorexia.

Science.gov (United States)

Lohuis, T D; Harlow, H J; Beck, T D I

2007-05-01

Black bears spend four to seven months every winter confined to their den and anorexic. Despite potential for skeletal muscle atrophy and protein loss, bears appear to retain muscle integrity throughout winter dormancy. Other authors have suggested that bears are capable of net protein anabolism during this time. The present study was performed to test this hypothesis by directly measuring skeletal muscle protein metabolism during the summer, as well as early and late hibernation periods. Muscle biopsies were taken from the vastus lateralis of six free-ranging bears in the summer, and from six others early in hibernation and again in late winter. Protein synthesis and breakdown were measured on biopsies using (14)C-phenylalanine as a tracer. Muscle protein, nitrogen, and nucleic acid content, as well as nitrogen stable isotope enrichment, were also measured. Protein synthesis was greater than breakdown in summer bears, suggesting that they accumulate muscle protein during periods of seasonal food availability. Protein synthesis and breakdown were both lower in winter compared to summer but were equal during both early and late denning, indicating that bears are in protein balance during hibernation. Protein and nitrogen content, nucleic acid, and stable isotope enrichment measurements of the biopsies support this conclusion.

Increasing Winter Maximal Metabolic Rate Improves Intrawinter Survival in Small Birds.

Science.gov (United States)

Petit, Magali; Clavijo-Baquet, Sabrina; Vézina, François

Small resident bird species living at northern latitudes increase their metabolism in winter, and this is widely assumed to improve their chances of survival. However, the relationship between winter metabolic performance and survival has yet to be demonstrated. Using capture-mark-recapture, we followed a population of free-living black-capped chickadees (Poecile atricapillus) over 3 yr and evaluated their survival probability within and among winters. We also measured the size-independent body mass (M s ), hematocrit (Hct), basal metabolic rate (BMR), and maximal thermogenic capacity (Msum) and investigated how these parameters influenced survival within and among winters. Results showed that survival probability was high and constant both within (0.92) and among (0.96) winters. They also showed that while M s , Hct, and BMR had no significant influence, survival was positively related to Msum-following a sigmoid relationship-within but not among winter. Birds expressing an Msum below 1.26 W (i.e., similar to summer levels) had a winter. Our data therefore suggest that black-capped chickadees that are either too slow or unable to adjust their phenotype from summer to winter have little chances of survival and thus that seasonal upregulation of metabolic performance is highly beneficial. This study is the first to document in an avian system the relationship between thermogenic capacity and winter survival, a proxy of fitness.

Carotene and provitamin A content of vegetables sold in Viçosa, MG, Brazil, during spring and winter

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Pollyanna Costa Cardoso

2009-09-01

Full Text Available This study investigated the α- and β-carotene content and provitamin A value of four leafy vegetables sold at local and street markets in Viçosa, MG, Brazil, in the spring and winter of 2002. Carotenoids were analyzed by high-performance liquid chromatography. α-Carotene was detected in all samples sold during spring, but was only present in a few samples of smooth and curly lettuce and kale in winter. β-Carotene was found in marked quantities in all leafy vegetables analyzed. Duncan's test (α = 5% showed significantly higher α-carotene content in curly lettuce and vitamin A value in large-leaved watercress in the spring. Mean β-carotene content and vitamin A value were 7544, 8751, 2584, 2792, 8193, and 5338 μg/100 g and 666, 760, 227, 238, 698, and 460 μg RAE/100 g in large-leaved and hydroponic watercress, smooth and curly lettuce, kale and spinach, respectively. All leafy vegetables analyzed represent important sources of provitamin A and supply an important part of the daily requirements of children and adults.Investigou-se o conteúdo de α e β-caroteno e avaliou-se o valor pro-vitamínico A de quatro hortaliças folhosas comercializadas em mercados locais e feira- livre de Viçosa, MG durante a primavera e o inverno de 2002. Os carotenóides foram analisados por Cromatografia Líquida de Alta Eficiência (CLAE. O α-caroteno foi detectado em todas as amostras analisadas na primavera, porém no inverno, somente algumas amostras de alface crespa e lisa, e couve apresentaram tal carotenóide. O β-caroteno foi encontrado, em quantidades apreciáveis, em todas as hortaliças folhosas analisadas. O teste de Duncan (α=5% detectou que o conteúdo de α-caroteno em alface crespa e o valor de vitamina A em agrião de folha larga foram estatisticamente superiores na primavera. Os teores médios de β-caroteno e de valor de vitamina A para agrião de folha larga e hidropônico, alface crespa e lisa, couve e espinafre foram: 7544; 8751

Blood lead concentrations in Alaskan tundra swans: linking breeding and wintering areas with satellite telemetry.

Science.gov (United States)

Ely, Craig R; Franson, J Christian

2014-04-01

Tundra swans (Cygnus columbianus) like many waterfowl species are susceptible to lead (Pb) poisoning, and Pb-induced mortality has been reported from many areas of their wintering range. Little is known however about Pb levels throughout the annual cycle of tundra swans, especially during summer when birds are on remote northern breeding areas where they are less likely to be exposed to anthropogenic sources of Pb. Our objective was to document summer Pb levels in tundra swans throughout their breeding range in Alaska to determine if there were population-specific differences in blood Pb concentrations that might pose a threat to swans and to humans that may consume them. We measured blood Pb concentrations in tundra swans at five locations in Alaska, representing birds that winter in both the Pacific Flyway and Atlantic Flyway. We also marked swans at each location with satellite transmitters and coded neck bands, to identify staging and wintering sites and determine if winter site use correlated with summer Pb concentrations. Blood Pb levels were generally low (<0.2 μg/ml) in swans across all breeding areas. Pb levels were lower in cygnets than adults, suggesting that swans were likely exposed to Pb on wintering areas or on return migration to Alaska, rather than on the summer breeding grounds. Blood Pb levels varied significantly across the five breeding areas, with highest concentrations in birds on the North Slope of Alaska (wintering in the Atlantic Flyway), and lowest in birds from the lower Alaska Peninsula that rarely migrate south for winter.

Measurements of 161 Double Stars With a High-Speed CCD: The Winter/Spring 2017 Observing Program at Brilliant Sky Observatory, Part 2

Science.gov (United States)

Harshaw, Richard

2018-04-01

In the winter and spring of 2017, an aggressive observing program of measuring close double stars with speckle interferometry and CCD imaging was undertaken at Brilliant Sky Observatory, my observing site in Cave Creek, Arizona. A total of 596 stars were observed, 8 of which were rejected for various reasons, leaving 588 pairs. Of these, 427 were observed and measured with speckle interferometry, while the remaining 161 were measured with a CCD. This paper reports the results of the observations of the 161 CCD cases. A separate paper in this issue will report the speckle measurements of the 427 other pairs.

What do we know about winter active ground beetles (Coleoptera, Carabidae) in Central and Northern Europe?

Science.gov (United States)

Jaskuła, Radomir; Soszyńska-Maj, Agnieszka

2011-01-01

This paper summarizes the current knowledge on winter active Carabidae in Central and Northern Europe. In total 73 winter active species are listed, based on literature and own observations. Ground beetles are among the three most numerous Coleoptera families active during the autumn to spring period. The winter community of Carabidae is composed both of larvae (mainly autumn breeding species) and adults, as well as of epigeic species and those inhabiting tree trunks. Supranivean fauna is characterized by lower species diversity than the subnivean fauna. The activity of ground beetles decreases in late autumn, is lowest during mid-winter and increases in early spring. Carabidae are noted as an important food source in the diet of insectivorous mammals. They are also predators, hunting small winter active invertebrates.

Summertime Minimum Streamflow Elasticity to Antecendent Winter Precipitation, Peak Snow Water Equivalent and Summertime Evaporative Demand in the Western US Maritime Mountains

Science.gov (United States)

Schaperow, J.; Cooper, M. G.; Cooley, S. W.; Alam, S.; Smith, L. C.; Lettenmaier, D. P.

2017-12-01

As climate regimes shift, streamflows and our ability to predict them will change, as well. Elasticity of summer minimum streamflow is estimated for 138 unimpaired headwater river basins across the maritime western US mountains to better understand how climatologic variables and geologic characteristics interact to determine the response of summer low flows to winter precipitation (PPT), spring snow water equivalent (SWE), and summertime potential evapotranspiration (PET). Elasticities are calculated using log log linear regression, and linear reservoir storage coefficients are used to represent basin geology. Storage coefficients are estimated using baseflow recession analysis. On average, SWE, PET, and PPT explain about 1/3 of the summertime low flow variance. Snow-dominated basins with long timescales of baseflow recession are least sensitive to changes in SWE, PPT, and PET, while rainfall-dominated, faster draining basins are most sensitive. There are also implications for the predictability of summer low flows. The R2 between streamflow and SWE drops from 0.62 to 0.47 from snow-dominated to rain-dominated basins, while there is no corresponding increase in R2 between streamflow and PPT.

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

How “lucky” we are that the Fukushima disaster occurred in early spring

Energy Technology Data Exchange (ETDEWEB)

Evangeliou, Nikolaos, E-mail: Nikolaos.Evangeliou@lsce.ipsl.fr [Laboratoire des Sciences du Climat et de l' Environnement (LSCE), CEA-UVSQ-CNRS UMR 8212, Institut Pierre et Simon Laplace, L' Orme des Merisiers, F-91191 Gif sur Yvette Cedex (France); Balkanski, Yves; Cozic, Anne [Laboratoire des Sciences du Climat et de l' Environnement (LSCE), CEA-UVSQ-CNRS UMR 8212, Institut Pierre et Simon Laplace, L' Orme des Merisiers, F-91191 Gif sur Yvette Cedex (France); Møller, Anders Pape [Laboratoire d' Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud, Bâtiment 362, F-91405 Orsay Cedex (France)

2014-12-01

The present paper studies how a random event (earthquake) and the subsequent disaster in Japan affect transport and deposition of fallout and the resulting health consequences. Therefore, except for the original accident in March 2011, three additional scenarios are assessed assuming that the same releases took place in winter 2010, summer 2011 and autumn 2011 in order to cover a full range of annual seasonality. This is also the first study where a large number of fission products released from the accident are used to assess health risks with the maximum possible efficiency. Xenon-133 and {sup 137}Cs are directly estimated within the model, whereas 15 other radionuclides are calculated indirectly using reported isotopic ratios. As much as 85% of the released {sup 137}Cs would be deposited in continental regions worldwide if the accident occurred in winter 2010, 22% in spring 2011 (when it actually happened), 55% in summer 2011 and 48% if it occurred during autumn 2011. Solid cancer incidents and mortalities from Fukushima are estimated to be between 160 and 880 and from 110 to 640 close to previous estimations. By adding thyroid cancers, the total number rises from 230 to 850 for incidents and from 120 to 650 for mortalities. Fatalities due to worker exposure and mandatory evacuation have been reported to be around 610 increasing total estimated mortalities to 730–1260. These estimates are 2.8 times higher than previously reported ones for radiocaesium and {sup 131}I and 16% higher than those reported based on radiocaesium only. Total expected fatalities from Fukushima are 32% lower than in the winter scenario, 5% that in the summer scenario and 30% lower than in the autumn scenario. Nevertheless, cancer fatalities are expected to be less than 5% of those from the tsunami (∼ 20,000). - Highlights: • A GCM was used to assess impacts of FND during different seasons. • Transport and deposition of multiple radionuclides were compared. • 110 to 640

How “lucky” we are that the Fukushima disaster occurred in early spring

International Nuclear Information System (INIS)

Evangeliou, Nikolaos; Balkanski, Yves; Cozic, Anne; Møller, Anders Pape

2014-01-01

The present paper studies how a random event (earthquake) and the subsequent disaster in Japan affect transport and deposition of fallout and the resulting health consequences. Therefore, except for the original accident in March 2011, three additional scenarios are assessed assuming that the same releases took place in winter 2010, summer 2011 and autumn 2011 in order to cover a full range of annual seasonality. This is also the first study where a large number of fission products released from the accident are used to assess health risks with the maximum possible efficiency. Xenon-133 and 137 Cs are directly estimated within the model, whereas 15 other radionuclides are calculated indirectly using reported isotopic ratios. As much as 85% of the released 137 Cs would be deposited in continental regions worldwide if the accident occurred in winter 2010, 22% in spring 2011 (when it actually happened), 55% in summer 2011 and 48% if it occurred during autumn 2011. Solid cancer incidents and mortalities from Fukushima are estimated to be between 160 and 880 and from 110 to 640 close to previous estimations. By adding thyroid cancers, the total number rises from 230 to 850 for incidents and from 120 to 650 for mortalities. Fatalities due to worker exposure and mandatory evacuation have been reported to be around 610 increasing total estimated mortalities to 730–1260. These estimates are 2.8 times higher than previously reported ones for radiocaesium and 131 I and 16% higher than those reported based on radiocaesium only. Total expected fatalities from Fukushima are 32% lower than in the winter scenario, 5% that in the summer scenario and 30% lower than in the autumn scenario. Nevertheless, cancer fatalities are expected to be less than 5% of those from the tsunami (∼ 20,000). - Highlights: • A GCM was used to assess impacts of FND during different seasons. • Transport and deposition of multiple radionuclides were compared. • 110 to 640 individuals are expected

[Characteristics of mass size distributions of water-soluble, inorganic ions during summer and winter haze days of Beijing].

Science.gov (United States)

Huang, Yi-Min; Liu, Zi-Rui; Chen, Hong; Wang, Yue-Si

2013-04-01

To investigate the size distribution characteristics of water soluble inorganic ions in haze days, the particle samples were collected by two Andersen cascade impactors in Beijing during summer and winter time and each sampling period lasted two weeks. Online measurement of PM10 and PM2.5 using TEOM were also conducted at the same time. Sources and formation mechanism of water soluble inorganic ions were analyzed based on their size distributions. The results showed that average concentrations of PM10 and PM 2.5 were (245.5 +/- 8.4) microg x m(-3) and (120.2 +/- 2.0) microg x m(-3) during summer haze days (SHD), and were (384.2 +/- 30.2) microg x m(-3) and (252.7 +/- 47.1) microg x m(-3) during winter haze days (WHD), which suggested fine particles predominated haze pollution episode in both seasons. Total water-soluble inorganic ions concentrations were higher in haze days than those in non-haze days, especially in fine particles. Furthermore, concentrations of secondary inorganic ions (SO4(2-), NO3(-) and NH4(+)) increased quicker than other inorganic ions in fine particles during haze days, indicating secondary inorganic ions played an important role in the formation of haze pollution. Similar size distributions were found for all Sinorganic water soluble ions except for NO3(-), during SHD and WHD. SO4(2-) and NH4(+) dominated in the fine mode (PM1.0) while Mg2+ and Ca2+ accumulated in coarse fraction, Na+, Cl- and K+ showed a bimodal distribution. For NO3(-), however, it showed a bimodal distribution during SHD and a unimodal distribution dominated in the fine fraction was found during WHD. The average mass median aerodynamic diameter (MMAD) of SO4(2-) was 0.64 microm in SHD, which suggested the formation of SO4(2-) was mainly attributed to in-cloud processes. Furthermore, a higher apparent conversion rate of sulfur dioxide (SOR) was found in SHD, indicating more fine particles were produced by photochemical reaction in haze days than that in non-haze days. The

Arctic Climate Variability and Trends from Satellite Observations

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Xuanji Wang

2012-01-01

Full Text Available Arctic climate has been changing rapidly since the 1980s. This work shows distinctly different patterns of change in winter, spring, and summer for cloud fraction and surface temperature. Satellite observations over 1982–2004 have shown that the Arctic has warmed up and become cloudier in spring and summer, but cooled down and become less cloudy in winter. The annual mean surface temperature has increased at a rate of 0.34°C per decade. The decadal rates of cloud fraction trends are −3.4%, 2.3%, and 0.5% in winter, spring, and summer, respectively. Correspondingly, annually averaged surface albedo has decreased at a decadal rate of −3.2%. On the annual average, the trend of cloud forcing at the surface is −2.11 W/m2 per decade, indicating a damping effect on the surface warming by clouds. The decreasing sea ice albedo and surface warming tend to modulate cloud radiative cooling effect in spring and summer. Arctic sea ice has also declined substantially with decadal rates of −8%, −5%, and −15% in sea ice extent, thickness, and volume, respectively. Significant correlations between surface temperature anomalies and climate indices, especially the Arctic Oscillation (AO index, exist over some areas, implying linkages between global climate change and Arctic climate change.

Nitrogen and carbohydrate fractions in exclusive Tifton 85 and in pasture oversown with annual winter forage species - 10.4025/actascianimsci.v34i1.11428

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Ana Claudia Ruggieri

2011-11-01

Full Text Available The experiment was undertaken at the Faculty of Agrarian and Veterinary Sciences (FCAV Jaboticabal, São Paulo State, Brazil, during winter-spring-summer of 2001-2002, to determine the fractionation of nitrogen and carbohydrates in Tifton 85 (Cynodon dactylon Vanderyst x Cynodon nlemfuensis (L. Pers, exclusively or oversown with winter annual forage species. Treatments comprised bristle oat (Avena strigosa Schreb, yellow oat (Avena byzantina C. Koch, triticale (X Triticosecale Wittmack, bristle oat + yellow oat, bristle oat + triticale, yellow oat + triticale, bristle oat + yellow oat + triticale seeded in Tifton 85 and sole crop (control. Experimental design was composed of completely randomized blocks with three replications. Fodder was cut 20 cm high (presence of winter forage and 10 cm high (Tifton 85 pasture. Crude protein, total carbohydrate and the fractions of nitrogen compounds and carbohydrates were determined. Decrease was reported in the levels of chemical compounds in winter forage species and in Tifton 85 during the evaluation periods. The content of nitrogen compounds and carbohydrates varied widely during the evaluation period according to the morphological characteristics of grass species and botanical composition of pastures.

Ecobiological assessment of a freshwater lake at Schirmacher Oasis, East Antarctica, with reference to human activities

Digital Repository Service at National Institute of Oceanography (India)

Ingole, B.S.; Dhargalkar, V.K.

) with higher values during winter months (June-July). The biological parameters - phytoplankton, chlorophyll-a and microbenthos - showed a bi-modal pattern of fluctuations with one maxima in austral summer and another in spring (late winter). Fluctuations...

Composition of late summer diet by semi-domesticated reindeer in different grazing conditions in northernmost Finland

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Pauline Bezard

2015-09-01

Full Text Available This study aims to investigate the diet composition of semi-domesticated reindeer (Rangifer tarandus tarandus in late summer in different kinds of grazing conditions in northernmost Finland. The composition of diet by reindeer was determined on the grounds of microhistological analysis of feces samples collected in early August in different seasonal grazing areas (winter or summer/year-round grazing areas in three reindeer management districts. Although the proportion of different plant groups varied between the studied districts, the quantified group of ground lichens (which also contained small amounts of mushrooms was the most abundant, varying from 33.0 to 46.4% in the analyzed samples. In general, there were significant differences in the proportions of lichen between districts, but not between grazing areas. The proportion of lichen in samples increased significantly when the amount of lichen pasture around a sample site increased. The proportion of dwarf shrubs and leaves in samples varied from 24.9 to 37.9% and differed significantly between districts, but not between grazing areas. In the same way, the proportion of graminoids varied between 20.9 and 36.2% and differed significantly between districts and also between grazing areas. Higher amounts of graminoids in feces were observed in summer/year-round grazing areas than in winter grazing areas. Finally, the proportion of bryophytes varied between 2.9 and 6.5% and was significantly different between districts, but not between grazing areas. An increase in old and mature coniferous forest around a sample site significantly increased the amounts of bryophytes in samples. The results indicate that reindeer adapt their summer diet composition according to the availability of food plants. The results also show that when reindeer are allowed to select their summer ranges freely, reindeer tend to use lichen pastures intensively also during summer, which causes a considerable reduction in

Condition of larval (furcilia VI) and one year old juvenile Euphausia superba during the winter-spring transition in East Antarctica

Science.gov (United States)

Virtue, Patti; Meyer, Bettina; Freier, Ulrich; Nichols, Peter D.; Jia, Zhongnan; King, Rob; Virtue, Jacob; Swadling, Kerrie M.; Meiners, Klaus M.; Kawaguchi, So

2016-09-01

Antarctic krill, Euphausia superba, is an important species in the Southern Ocean ecosystem. Information on krill condition during winter and early spring is slowly evolving with our enhanced ability to sample at this time of year. However, because of the limited spatial and temporal data, our understanding of fundamental biological parameters for krill during winter is limited. Our study assessed the condition of larval (furcilia VI) and one year old juvenile krill collected in East Antarctica (115°E-130°E and 64°S-66°S) from September to October 2012. Krill condition was assessed using morphometric, elemental and biochemical body composition, growth rates, oxygen uptake and lipid content and composition. Diet was assessed using fatty acid biomarkers analysed in the krill. The growth rate of larvae was 0.0038 mm day with an inter-moult period of 14 days. The average oxygen uptake of juvenile krill was 0.30±0.02 μl oxygen consumed per mg dry weight per hour. Although protein was not significantly different amongst the krill analysed, the lipid content of krill was highly variable ranging from 9% to 27% dry weight in juveniles and from 4% to 13% dry weight in larvae. Specific algal biomarkers, fatty acids ratios, levels of both long-chain (≥C20) monounsaturated fatty acids and bacterial fatty acids found in krill were indicative of the mixed nature of dietary sources and the opportunistic feeding capability of larval and juvenile krill at the end of winter.

A seasonal-scale climatological analysis correlating spring tornadic activity with antecedent fall-winter drought in the southeastern United States

International Nuclear Information System (INIS)

Shepherd, Marshall; Mote, Thomas L; Niyogi, Dev

2009-01-01

Using rain gauge and satellite-based rainfall climatologies and the NOAA Storm Prediction Center tornado database (1952-2007), this study found a statistically significant tendency for fall-winter drought conditions to be correlated with below-normal tornado days the following spring in north Georgia (i.e. 93% of the years) and other regions of the Southeast. Non-drought years had nearly twice as many tornado days in the study area as drought years and were also five to six times more likely to have multiple tornado days. Individual tornadic events are largely a function of the convective-mesoscale thermodynamic and dynamic environments, thus the study does not attempt to overstate predictability. Yet, the results may provide seasonal guidance in an analogous manner to the well known Sahelian rainfall and Cape Verde hurricane activity relationships.

What do we know about winter active ground beetles (Coleoptera, Carabidae in Central and Northern Europe?

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Radomir Jaskula

2011-05-01

Full Text Available This paper summarizes the current knowledge on winter active Carabidae in Central and Northern Europe. In total 73 winter active species are listed, based on literature and own observations. Ground beetles are among the three most numerous Coleoptera families active during the autumn to spring period. The winter community of Carabidae is composed both of larvae (mainly autumn breeding species and adults, as well as of epigeic species and those inhabiting tree trunks. Supranivean fauna is characterized by lower species diversity than the subnivean fauna. The activity of ground beetles decreases in late autumn, is lowest during mid-winter and increases in early spring. Carabidae are noted as an important food source in the diet of insectivorous mammals. They are also predators, hunting small winter active invertebrates.

Correlation and anti-correlation of the East Asian summer and winter monsoons during the last 21,000 years.

Science.gov (United States)

Wen, Xinyu; Liu, Zhengyu; Wang, Shaowu; Cheng, Jun; Zhu, Jiang

2016-06-22

Understanding the past significant changes of the East Asia Summer Monsoon (EASM) and Winter Monsoon (EAWM) is critical for improving the projections of future climate over East Asia. One key issue that has remained outstanding from the paleo-climatic records is whether the evolution of the EASM and EAWM are correlated. Here, using a set of long-term transient simulations of the climate evolution of the last 21,000 years, we show that the EASM and EAWM are positively correlated on the orbital timescale in response to the precessional forcing, but are anti-correlated on millennial timescales in response to North Atlantic melt water forcing. The relation between EASM and EAWM can differ dramatically for different timescales because of the different response mechanisms, highlighting the complex dynamics of the East Asian monsoon system and the challenges for future projection.

Evaluation of the 1996 predictions of the run-timing of wild migrant spring/summer yearling chinook in the Snake River Basin using Program RealTime

International Nuclear Information System (INIS)

Townsend, R.L.; Yasuda, D.; Skalski, J.R.

1997-03-01

This report is a post-season analysis of the accuracy of the 1996 predictions from the program RealTime. Observed 1996 migration data collected at Lower Granite Dam were compared to the predictions made by RealTime for the spring outmigration of wild spring/summer chinook. Appendix A displays the graphical reports of the RealTime program that were interactively accessible via the World Wide Web during the 1996 migration season. Final reports are available at address http://www.cqs.washington.edu/crisprt/. The CRISP model incorporated the predictions of the run status to move the timing forecasts further down the Snake River to Little Goose, Lower Monumental and McNary Dams. An analysis of the dams below Lower Granite Dam is available separately

An experimental field evaluation of winter carryover effects in semi-anadromous brown trout (Salmo trutta).

Science.gov (United States)

Midwood, Jonathan D; Larsen, Martin H; Boel, Mikkel; Aarestrup, Kim; Cooke, Steven J

2015-11-01

For semi-anadromous brown trout, the decision whether or not to smoltify and migrate to the sea is believed to be made at the end of the preceding summer in response to both local environmental conditions and individual physiological status. Stressors experienced during the fall may therefore influence their propensity to migrate as well as carry over into the winter resulting in mortality when fish face challenging environmental conditions. To evaluate this possibility, we artificially elevated cortisol levels in juvenile trout (via intracoelomic injection of cortisol in the fall) and used passive integrated transponder tags to compare their overwinter and spring survival, growth, and migration success relative to a control group. Results suggest that overwinter mortality is high for individuals in this population regardless of treatment. However, survival rates were 2.5 times lower for cortisol-treated fish and they experienced significantly greater loss in mass. In addition, less than half as many cortisol-treated individuals made it downstream to a stationary antenna over the winter and also during the spring migration compared to the control treatment. These results suggest that a fall stressor can reduce overwinter survival of juvenile brown trout, negatively impact growth of individuals that survive, and ultimately result in a reduction in the number of migratory trout. Carryover effects such as those documented here reveal the cryptic manner in which natural and anthropogenic stressors can influence fish populations. J. Exp. Zool. 323A: 645-654, 2015. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Northerly surface winds over the eastern North Pacific Ocean in spring and summer

Science.gov (United States)

Taylor, S.V.; Cayan, D.R.; Graham, N.E.; Georgakakos, K.P.

2008-01-01

Persistent spring and summer northerly surface winds are the defining climatological feature of the western coast of North America, especially south of the Oregon coast. Northerly surface winds are important for upwelling and a vast array of other biological, oceanic, and atmospheric processes. Intermittence in northerly coastal surface wind is characterized and wind events are quantitatively defined using coastal buoy data south of Cape Mendocino on the northern California coast. The defined wind events are then used as a basis for composites in order to explain the spatial evolution of various atmospheric and oceanic processes. Wind events involve large-scale changes in the three-dimensional atmospheric circulation including the eastern North Pacific subtropical anticyclone and southeast trade winds. Composites of QSCAT satellite scatterometer wind estimates from 1999 to 2005 based on a single coastal buoy indicate that wind events typically last 72-96 h and result in anomalies in surface wind and Ekman pumping that extend over 1000 kin from the west coast of North America. It may be useful to consider ocean circulation and dependent ecosystem dynamics and the distribution of temperature, moisture, and aerosols in the atmospheric boundary layer in the context of wind events defined herein. Copyright 2008 by the American Geophysical Union.

Association between the 2008-09 seasonal influenza vaccine and pandemic H1N1 illness during Spring-Summer 2009: four observational studies from Canada.

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Danuta M Skowronski

2010-04-01

Full Text Available In late spring 2009, concern was raised in Canada that prior vaccination with the 2008-09 trivalent inactivated influenza vaccine (TIV was associated with increased risk of pandemic influenza A (H1N1 (pH1N1 illness. Several epidemiologic investigations were conducted through the summer to assess this putative association.(1 test-negative case-control design based on Canada's sentinel vaccine effectiveness monitoring system in British Columbia, Alberta, Ontario, and Quebec; (2 conventional case-control design using population controls in Quebec; (3 test-negative case-control design in Ontario; and (4 prospective household transmission (cohort study in Quebec. Logistic regression was used to estimate odds ratios for TIV effect on community- or hospital-based laboratory-confirmed seasonal or pH1N1 influenza cases compared to controls with restriction, stratification, and adjustment for covariates including combinations of age, sex, comorbidity, timeliness of medical visit, prior physician visits, and/or health care worker (HCW status. For the prospective study risk ratios were computed. Based on the sentinel study of 672 cases and 857 controls, 2008-09 TIV was associated with statistically significant protection against seasonal influenza (odds ratio 0.44, 95% CI 0.33-0.59. In contrast, estimates from the sentinel and three other observational studies, involving a total of 1,226 laboratory-confirmed pH1N1 cases and 1,505 controls, indicated that prior receipt of 2008-09 TIV was associated with increased risk of medically attended pH1N1 illness during the spring-summer 2009, with estimated risk or odds ratios ranging from 1.4 to 2.5. Risk of pH1N1 hospitalization was not further increased among vaccinated people when comparing hospitalized to community cases.Prior receipt of 2008-09 TIV was associated with increased risk of medically attended pH1N1 illness during the spring-summer 2009 in Canada. The occurrence of bias (selection, information or

Gross primary production controls the subsequent winter CO2 exchange in a boreal peatland.

Science.gov (United States)

Zhao, Junbin; Peichl, Matthias; Öquist, Mats; Nilsson, Mats B

2016-12-01

In high-latitude regions, carbon dioxide (CO 2 ) emissions during the winter represent an important component of the annual ecosystem carbon budget; however, the mechanisms that control the winter CO 2 emissions are currently not well understood. It has been suggested that substrate availability from soil labile carbon pools is a main driver of winter CO 2 emissions. In ecosystems that are dominated by annual herbaceous plants, much of the biomass produced during the summer is likely to contribute to the soil labile carbon pool through litter fall and root senescence in the autumn. Thus, the summer carbon uptake in the ecosystem may have a significant influence on the subsequent winter CO 2 emissions. To test this hypothesis, we conducted a plot-scale shading experiment in a boreal peatland to reduce the gross primary production (GPP) during the growing season. At the growing season peak, vascular plant biomass in the shaded plots was half that in the control plots. During the subsequent winter, the mean CO 2 emission rates were 21% lower in the shaded plots than in the control plots. In addition, long-term (2001-2012) eddy covariance data from the same site showed a strong correlation between the GPP (particularly the late summer and autumn GPP) and the subsequent winter net ecosystem CO 2 exchange (NEE). In contrast, abiotic factors during the winter could not explain the interannual variation in the cumulative winter NEE. Our study demonstrates the presence of a cross-seasonal link between the growing season biotic processes and winter CO 2 emissions, which has important implications for predicting winter CO 2 emission dynamics in response to future climate change. © 2016 John Wiley & Sons Ltd.

Increased risk of a shutdown of ocean convection posed by warm North Atlantic summers

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Oltmanns, Marilena; Karstensen, Johannes; Fischer, Jürgen

2018-04-01

A shutdown of ocean convection in the subpolar North Atlantic, triggered by enhanced melting over Greenland, is regarded as a potential transition point into a fundamentally different climate regime1-3. Noting that a key uncertainty for future convection resides in the relative importance of melting in summer and atmospheric forcing in winter, we investigate the extent to which summer conditions constrain convection with a comprehensive dataset, including hydrographic records that are over a decade in length from the convection regions. We find that warm and fresh summers, characterized by increased sea surface temperatures, freshwater concentrations and melting, are accompanied by reduced heat and buoyancy losses in winter, which entail a longer persistence of the freshwater near the surface and contribute to delaying convection. By shortening the time span for the convective freshwater export, the identified seasonal dynamics introduce a potentially critical threshold that is crossed when substantial amounts of freshwater from one summer are carried over into the next and accumulate. Warm and fresh summers in the Irminger Sea are followed by particularly short convection periods. We estimate that in the winter 2010-2011, after the warmest and freshest Irminger Sea summer on our record, 40% of the surface freshwater was retained.

Clearfield®-Clentiga® and Clearfield® Kombi-Pack: Two new herbicides for targeted weed control in winter- and spring oilseed rape

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Schönhammer, Alfons

2014-02-01

Full Text Available Currently, the Clearfield® Production System in winter oilseed rape in Germany is based on the herbicide Clearfield®-Vantiga® , a combination product consisting of the active ingredients metazachlor, quinmerac and imazamox, sold as Clearfield-Vantiga D together with the adjuvant Dash® E.C.. Clearfield-Vantiga D was introduced in autumn 2012 and has since proved superior performance on more than 10 000 ha of heavily weedy fields due to the very broad spectrum of activity, reliable foliar and soil activity and excellent crop safety in Clearfield oilseed rape hybrids. Although the authorized application period is very long (BBCH 10-18, it is mostly used relatively early, as soon as the majority of the important weeds is emerged. Metazachlor which is active mainly by cotyledon, hypocotyl and root uptake, is favoured by early applications. Clearfield-Clentiga is a suspension concentrate (SC, consisting of 250 g/l quinmerac and 12.5 g/l imazamox . The application rate is 1.0 l/ha + 1.0 l/ha of the adjuvant Dash E.C.. Approval is sought for use in winter oilseed rape in autumn (BBCH 10-18 and spring (BBCH 30-50 and in spring oilseed rape (BBCH 10-18. Results are presented for the autumn application in winter oilseed rape. A prerequisite for the application of both Clearfield-Clentiga and Clearfield-Vantiga D is the use of imazamox tolerant oilseed rape (Clearfield varieties. The amounts of active ingredient per hectare of quinmerac and imazamox are identical in Clearfield-Clentiga and Clearfield-Vantiga D, as well as the amount of adjuvant Dash E.C.. Clearfield-Clentiga, as a consequence of the absence of metazachlor, compared to Clearfield-Vantiga D has a slightly more limited spectrum of activity and a less pronounced soil activity, but provides greater flexibility in the choice of the application dates and of combinations with soil and foliar herbicides. Very effective, even at high weed pressure and in difficult soil conditions, are sequential

Atmospheric Pollution and Greenhouse Emissions over 14 Largest Megacities of the World

Science.gov (United States)

Chen, X.; Singh, R. P.

2017-12-01

Megacities have more than 10 million people, some of them are located in developing/developed countries. We have considered the top 14 megacities of the world. Due to growing industries, urbanization, vehicular density, and energy demand, greenhouse gas emissions have increased, which has degraded air quality. In some countries, clean air act has improved the air quality. We have considered multiple satellites and have retrieved atmospheric pollution parameters (aerosol optical depth-AOD and angstrom exponent) and greenhouse gases to study their variability from the period 2002-2016. High AOD represents high pollution level, which are prominent during winter and spring for Manila, Tokyo, Beijing, Moscow, Mexico City, Mumbai, Seoul, Dhaka, Cairo, and Bangkok. During summer and fall, Delhi, Karachi, and Sao Paulo have high values. During spring season, some of the megacities show significant higher pollution levels (high AOD) associated with the dust storms; however, Moscow and Karachi show contrasting behaviors. The angstrom exponent parameter has high values in the spring and summer for Manila, Shanghai, Beijing, Moscow, Sao Paulo, Mexico City, Seoul, and Cairo. Moscow shows a significant low value in April 2012. Delhi, Karachi, Mumbai, Dhaka, and Bangkok have high values in fall and winter. Dhaka shows significant low values in August 2003, June 2005, June 2008, July 2011, and June 2016. The total ozone column concentrations have high values during summer and spring, and low values during fall and winter. The methane concentrations are higher during fall and winter, and lower during spring and summer. An increasing trend of methane level is observed over all the megacities from 2002 until now. The increasing greenhouse gases in megacities have direct impact on human health and weather conditions. Some of the megacities suffer from dense haze, fog and smog, which impact the day-to-day lives of residents due to increasing concentrations of greenhouse gases.

Hibernation in an antarctic fish: on ice for winter.

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Hamish A Campbell

Full Text Available Active metabolic suppression in anticipation of winter conditions has been demonstrated in species of mammals, birds, reptiles and amphibians, but not fish. This is because the reduction in metabolic rate in fish is directly proportional to the decrease in water temperature and they appear to be incapable of further suppressing their metabolic rate independently of temperature. However, the Antarctic fish (Notothenia coriiceps is unusual because it undergoes winter metabolic suppression irrespective of water temperature. We assessed the seasonal ecological strategy by monitoring swimming activity, growth, feeding and heart rate (f(H in N. coriiceps as they free-ranged within sub-zero waters. The metabolic rate of wild fish was extrapolated from f(H recordings, from oxygen consumption calibrations established in the laboratory prior to fish release. Throughout the summer months N. coriiceps spent a considerable proportion of its time foraging, resulting in a growth rate (G(w of 0.18 +/- 0.2% day(-1. In contrast, during winter much of the time was spent sedentary within a refuge and fish showed a net loss in G(w (-0.05 +/- 0.05% day(-1. Whilst inactive during winter, N. coriiceps displayed a very low f(H, reduced sensory and motor capabilities, and standard metabolic rate was one third lower than in summer. In a similar manner to other hibernating species, dormancy was interrupted with periodic arousals. These arousals, which lasted a few hours, occurred every 4-12 days. During arousal activity, f(H and metabolism increased to summer levels. This endogenous suppression and activation of metabolic processes, independent of body temperature, demonstrates that N. coriiceps were effectively 'putting themselves on ice' during winter months until food resources improved. This study demonstrates that at least some fish species can enter a dormant state similar to hibernation that is not temperature driven and presumably provides seasonal energetic

Summer 2011 forecast analysis. Forecast analysis of the electricity supply-demand balance in France for the summer of 2011

International Nuclear Information System (INIS)

2011-06-01

Twice a year, RTE publishes a forecast study of the electricity supply and demand in continental France for the summer and winter periods. The study is based on the information supplied by electric utilities concerning the expected availability of power generation means and on statistical meteorological models. Safety margins are calculated using thousands of probabilistic scenarios combining various production and consumption situations. This report is the forecast study for the summer of 2011

Coupling the Mars Dust and Water Cycles: Investigating the Role of Clouds in Controlling the Vertical Distribution of Dust During N. H. Summer

Science.gov (United States)

Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Wilson, R. J.

2014-01-01

The dust cycle is critically important for the current climate of Mars. The radiative effects of dust impact the thermal and dynamical state of the atmosphere (Gierasch and Goody, 1968; Haberle et al., 1982; Zurek et al., 1992). Although dust is present in the Martian atmosphere throughout the year, the level of dustiness varies with season. The atmosphere is generally the dustiest during northern fall and winter and the least dusty during northern spring and summer (Smith, 2004). Dust particles are lifted into the atmosphere by dust storms that range in size from meters to thousands of kilometers across (Cantor et al., 2001). During some years, regional storms combine to produce hemispheric or planet encircling dust clouds that obscure the surface and raise atmospheric temperatures by as much as 40 K (Smith et al., 2002). Key recent observations of the vertical distribution of dust indicate that elevated layers of dust exist in the tropics and sub-tropics throughout much of the year (Heavens et al., 2011). These observations have brought particular focus on the processes that control the vertical distribution of dust in the Martian atmosphere. The goal of this work is to further our understanding of how clouds in particular control the vertical distribution of dust, particularly during N. H. spring and summer

Behavioral characteristics of Hanwoo ( steers at different growth stages and seasons

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Na Yeon Kim

2017-10-01

Full Text Available Objective This research analyzed behavioral characteristics of Hanwoo (Bos taurus coreanae steers during each season and growth stage to enable measurement of the animals’ welfare level for precision livestock farming. Methods A hundred-eight beef steers were divided into three equal groups at a Hanwoo farm according to their growth stage: growing stage (GS, 8 months; early-fattening stage (EFS, 19 months; and late-fattening stage (LFS, 30 months. Twelve behavioral categories were continuously recorded for 13 day-time hours in each four seasons with three replications. Results Time spent standing was found to be significantly longer in summer at all growth stages (p<0.05. Hanwoos at the GS spent significantly longer standing time in spring and summer than those at the EFS and LFS (p<0.05. Lying time in summer was the shortest for all growth stages (p<0.05. Steers at the LFS spent significantly longer lying time than that at the GS (p<0.05 in summer. For GS and EFS, time spent eating in spring and autumn were longer than in summer and winter (p<0.05. Eating time was the longest for the GS in spring, autumn, and winter, excluding for the LFS in winter (p<0.05. Regarding ruminating, steers at the LFS spent significantly shorter time than those at other stages in all seasons (p<0.05. GS and EFS steers showed the longest walking time in summer compared with other seasons (p<0.05. At GS and LFS, drinking time in summer was the longest of all seasons (p<0.05. Sleeping time was significantly shorter in summer compared with the other seasons (p<0.05. Self-grooming time was the longest in winter for all growth stages (p<0.05. Conclusion Steers were found to have more variable behavioral patterns during summer and the GS and less active behaviors during the LFS, thus extra care seems necessary during the GS, LFS, and summer period.

Variation of Main Phenophases in Phenological Calendar in East China and Their Response to Climate Change

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Fengyi Zheng

2016-01-01

Full Text Available Based on the phenological data from China Phenological Observation Network, we compiled the phenological calendars of 3 phenological observation stations (Shanghai, Nanjing, and Hefei in East China for 1987–1996 and 2003–2012 according to the sequences of mean phenophases. We calculated the correlated coefficient and the root mean square error (RMSE between phenophases and the beginning of meteorological seasons to determine the beginning date of phenological season. By comparing new phenological calendars with the old ones, we discussed the variation of phenophases and their responses to temperature. The conclusions are as follows. (1 The beginning dates of spring and summer advanced, while those of autumn and winter delayed. Thus, summers got longer and winters got shorter. (2 The beginning time of the four phenological seasons was advancing during 1987–1996, while it was delaying during 2003–2012. (3 Most spring and summer phenophases occur earlier and most autumn and winter phenophases occur later in 2003–2012 than in 1987–1996. (4 The beginning time of phenological seasons was significantly correlated with temperature. The phenological sensitivities to temperature ranged from −6.49 to −6.55 days/°C in spring, −3.65 to −5.02 days/°C in summer, 8.13 to 10.27 days/°C in autumn, and 4.76 to 10.00 days/°C in winter.

Estratégias de manejo de inverno e verão visando ao controle de Conyza bonariensis e Bidens pilosa Winter and summer management strategies for Conyza bonariensis and Bidens pilosa control

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A.M. Oliveira Neto

2010-01-01

Full Text Available Conyza bonariensis é uma das principais plantas daninhas da região Sul do País; com a seleção de biótipos tolerantes e resistentes ao herbicida glyphosate, demandas são crescentes por alternativas de manejo para essa espécie. Com esse intuito, o objetivo do presente trabalho foi avaliar a eficiência de diferentes estratégias de manejo de inverno e de verão sobre o controle de Conyza bonariensis, utilizando a mistura em tanque de glyphosate+2,4-D associada ou não com herbicidas residuais. As combinações de manejo foram realizadas após a colheita do milho safrinha (manejo de inverno, associadas a manejos antecedendo a semeadura da soja (manejo de verão, totalizando 15 tratamentos. Os manejos de inverno avaliados foram eficientes na dessecação das plantas daninhas e mantiveram excelentes níveis de controle residual até a pré-semeadura da cultura da soja. A semeadura da aveia após o manejo de inverno com posterior manejo de verão com glyphosate+2,4-D+diclosulam mostrou-se eficiente no controle de Bidens pilosa. Em todos os manejos em que o herbicida 2,4-D foi associado ao glyphosate houve controle total de Conyza bonariensis.Conyza bonariensis is one of the most important weeds in southern Brazil. The selection of biotypes tolerant and resistant to the herbicide glyphosate has led to increasing demand for alternatives of management strategy to control this species. This work aimed to evaluate the efficiency of different winter and summer management strategy for the control of Conyza bonariensis, by using glyphosate + 2,4-D tank mixtures combined or not with residual herbicides. The different burndown alternatives were applied after corn harvest (winter burndown, associated to applications before soybean sowing (summer burndown with a total of 15 treatments. Winter burndown options evaluated in this research were efficient in weed desiccation and provided excellent levels of residual weed control up to the next summer soybean

What Controls the Temperature of the Arctic Stratosphere during the Spring?

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Newman, Paul A.; Nash, Eric R.; Rosenfield, Joan E.; Einaudi, Franco (Technical Monitor)

2000-01-01

Understanding the mechanisms that control the temperature of the polar lower stratosphere during spring is key to understanding ozone loss in the Arctic polar vortex. Spring ozone loss rates are directly tied to polar stratospheric temperatures by the formation of polar stratospheric clouds, and the conversion of chlorine species to reactive forms on these cloud particle surfaces. In this paper, we study those factors that control temperatures in the polar lower stratosphere. We use the National Centers for Environmental Prediction (NCEP)/NCAR reanalysis data covering the last two decades to investigate how planetary wave driving of the stratosphere is connected to polar temperatures. In particular, we show that planetary waves forced in the troposphere in mid- to late winter (January-February) are principally responsible for the mean polar temperature during the March period. These planetary waves are forced by both thermal and orographic processes in the troposphere, and propagate into the stratosphere in the mid and high latitudes. Strong mid-winter planetary wave forcing leads to a warmer Arctic lower stratosphere in early spring, while weak mid-winter forcing leads to cooler Arctic temperatures.

Winter Video Series Coming in January | Poster

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The Scientific Library’s annual Summer Video Series was so successful that it will be offering a new Winter Video Series beginning in January. For this inaugural event, the staff is showing the eight-part series from National Geographic titled “American Genius.” 

Seasonal and annual precipitation time series trend analysis in North Carolina, United States

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Sayemuzzaman, Mohammad; Jha, Manoj K.

2014-02-01

The present study performs the spatial and temporal trend analysis of the annual and seasonal time-series of a set of uniformly distributed 249 stations precipitation data across the state of North Carolina, United States over the period of 1950-2009. The Mann-Kendall (MK) test, the Theil-Sen approach (TSA) and the Sequential Mann-Kendall (SQMK) test were applied to quantify the significance of trend, magnitude of trend, and the trend shift, respectively. Regional (mountain, piedmont and coastal) precipitation trends were also analyzed using the above-mentioned tests. Prior to the application of statistical tests, the pre-whitening technique was used to eliminate the effect of autocorrelation of precipitation data series. The application of the above-mentioned procedures has shown very notable statewide increasing trend for winter and decreasing trend for fall precipitation. Statewide mixed (increasing/decreasing) trend has been detected in annual, spring, and summer precipitation time series. Significant trends (confidence level ≥ 95%) were detected only in 8, 7, 4 and 10 nos. of stations (out of 249 stations) in winter, spring, summer, and fall, respectively. Magnitude of the highest increasing (decreasing) precipitation trend was found about 4 mm/season (- 4.50 mm/season) in fall (summer) season. Annual precipitation trend magnitude varied between - 5.50 mm/year and 9 mm/year. Regional trend analysis found increasing precipitation in mountain and coastal regions in general except during the winter. Piedmont region was found to have increasing trends in summer and fall, but decreasing trend in winter, spring and on an annual basis. The SQMK test on "trend shift analysis" identified a significant shift during 1960 - 70 in most parts of the state. Finally, the comparison between winter (summer) precipitations with the North Atlantic Oscillation (Southern Oscillation) indices concluded that the variability and trend of precipitation can be explained by the

Pilot project 'Karst water Dachstein'. Vol. 2: karst hydrology and contamination risk in springs

International Nuclear Information System (INIS)

Scheidleder, A.; Mandl, G.W.; Boroviczeny, F.; Hofmann, T.; Schubert, G.; Trimborn, P.; Stichler, W.; Graf, W.

2001-01-01

Ordinance. In August 1991 (summer flood) quantifiable concentrations were found more frequently in the springs fed from glaciers and high-lying areas. No pesticides or polychlorinated biphenyls were found at any time although the set detection limits were very low. Higher concentration levels of heavy metals were found in the winter period (Zn, Cu), during snow melt (Fe, AI, Ni) and in the summer period (Mn, Cd, Sr, Ba). In the course of the environmental isotope analysis, 5 samples (taken quarterly) from each of 40 springs and 21 samples (taken quarterly and monthly) from each of 13 springs were examined for the presence of the isotopes deuterium and oxygen-18. Precipitation had been examined for several years (since 1973) in the course of the series of measurements carried out at two precipitation collectors of the Austrian Monitoring Network for Isotopes in the Dachstein area. One collector was set up an the Krippenstein for a period of 3 years. Four springs were examined over the period from August 1991 to June 1994 to determine the content of tritium. The relevant concentrations in the precipitation were derived from the evaluations of the Austrian Monitoring Network for Isotopes. (author)

Winter to spring variations of chromophoric dissolved organic matter in a temperate estuary (Po River, northern Adriatic Sea).

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Berto, D; Giani, M; Savelli, F; Centanni, E; Ferrari, C R; Pavoni, B

2010-07-01

The light absorbing fraction of dissolved organic carbon (DOC), known as chromophoric dissolved organic matter (CDOM) showed wide seasonal variations in the temperate estuarine zone in front of the Po River mouth. DOC concentrations increased from winter through spring mainly as a seasonal response to increasing phytoplankton production and thermohaline stratification. The monthly dependence of the CDOM light absorption by salinity and chlorophyll a concentrations was explored. In 2003, neither DOC nor CDOM were linearly correlated with salinity, due to an exceptionally low Po river inflow. Though the CDOM absorbance coefficients showed a higher content of chromophoric dissolved organic matter in 2004 with respect to 2003, the spectroscopic features confirmed that the qualitative nature of CDOM was quite similar in both years. CDOM and DOC underwent a conservative mixing, only after relevant Po river freshets, and a change in optical features with an increase of the specific absorption coefficient was observed, suggesting a prevailing terrestrial origin of dissolved organic matter. Published by Elsevier Ltd.

Summer to Winter Diurnal Variabilities of Temperature and Water Vapour in the Lowermost Troposphere as Observed by HAMSTRAD over Dome C, Antarctica

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Ricaud, P.; Genthon, C.; Durand, P.; Attié, J.-L.; Carminati, F.; Canut, G.; Vanacker, J.-F.; Moggio, L.; Courcoux, Y.; Pellegrini, A.; Rose, T.

2012-04-01

The HAMSTRAD (H2O Antarctica Microwave Stratospheric and Tropospheric Radiometers) microwave radiometer operating at 60 GHz (oxygen line, thus temperature) and 183 GHz (water vapour line) has been permanently deployed at the Dome C station, Concordia, Antarctica [75°06'S, 123°21'E, 3,233 m above mean sea level] in January 2010 to study long-term trends in tropospheric absolute humidity and temperature. The great sensitivity of the instrument in the lowermost troposphere helped to characterize the diurnal cycle of temperature and H2O from the austral summer (January 2010) to the winter (June 2010) seasons from heights of 10 to 200 m in the planetary boundary layer (PBL). The study has characterized the vertical resolution of the HAMSTRAD measurements: 10-20 m for temperature and 25-50 m for H2O. A strong diurnal cycle in temperature and H2O (although noisier) has been measured in summertime at 10 m, decreasing in amplitude with height, and phase-shifted by about 4 h above 50 m with a strong H2O-temperature correlation (>0.8) throughout the entire PBL. In autumn, whilst the diurnal cycle in temperature and H2O is less intense, a 12-h phase shift is observed above 30 m. In wintertime, a weak diurnal signal measured between 10 to 200 m is attributed to the methodology employed, which consists of monthly averaged data, and that combines air masses from different origins (sampling effect) and not to the imprint of the null solar irradiation. In situ sensors scanning the entire 24-h period, radiosondes launched at 2000 local solar time (LST) and European Centre for Medium-Range Weather Forecasts (ECMWF) analyses at 0200, 0800, 1400 and 2000 LST agree very well with the HAMSTRAD diurnal cycles for temperature and relatively well for absolute humidity. For temperature, HAMSTRAD tends to be consistent with all the other datasets but shows a smoother vertical profile from 10 to 100 m compared to radiosondes and in-situ data, with ECMWF profiles even smoother than HAMSTRAD

Effects of Tropical Rotation Crops on Meloidogyne arenaria Population Densities and Vegetable Yields in Microplots.

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McSorley, R; Dickson, D W; de Brito, J A; Hewlett, T E; Frederick, J J

1994-06-01

The effects of 12 summer crop rotation treatments on population densities of Meloidogyne arenaria race 1 and on yields of subsequent spring vegetable crops were determined in microplots. The crop sequence was: (i) rotation crops during summer 1991 ; (ii) cover crop of rye (Secale cereale) during winter 1991-92; (iii) squash (Cucurbita pepo) during spring 1992; (iv) rotation crops during summer 1992; (v) rye during winter 1992-93; (vi) eggplant (Solanum melongena) during spring 1993. The 12 rotation treatments were castor (Ricinus communis), cotton (Gossypium hirsutum), velvetbean (Mucuna deeringiana), crotalaria (Crotalaria spectabilis), fallow, hairy indigo (Indigofera hirsuta), American jointvetch (Aeschynomene americana), sorghum-sudangrass (Sorghum bicolor x S. sudanense), soybean (Glycine max), horsebean (Canavalia ensiformis), sesame (Sesamum indicum), and peanut (Arachis hypogaea). Compared to peanut, the first eight rotation treatments resulted in lower (P crops may provide a means for depressing M. arenaria population densities on a short-term basis to enhance yields in a subsequent susceptible vegetable crop.

Influence of summer biogeography on wood warbler stopover abundance

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Jeffrey F. Kelly; Rob Smith; Deborah M. Finch; Frank R. Moore; Wang Yong

1999-01-01

We evaluated the effect of summer biogeography of migrant wood warblers (Parulidae) on their stopover abundance. To characterize abundance patterns, we used mist-net capture data from spring and fall migration in the Middle Rio Grande Valley, New Mexico, spring migration on the Gulf Coast of Louisiana, and fall migration on the Gulf Coast of Alabama. To describe the...

[Transient elevation of intraocular pressure in primary open-angle glaucoma patients after automated visual field examination in the winter].

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Nishino, Kazuaki; Yoshida, Fujiko; Nitta, Akari; Saito, Mieko; Saito, Kazuuchi

2013-12-01

To evaluate retrospectively seasonal fluctuations of transient intraocular pressure (IOP) elevation after automated visual field examination in patients with primary open-angle glaucoma (POAG). We reviewed 53 consecutive patients with POAG who visited Kaimeido Ophthalmic and Dental Clinic from January 2011 to March 2013, 21 men and 32 women aged 67.7 +/- 11.2 years. The patients were divided into 4 groups, spring, summer, autumn, and winter according to the month of automated visual field examination and both eyes of each patient were enrolled. IOP was measured immediately after automated visual field examination (vf IOP) and compared with the average IOP from the previous 3 months (pre IOP) and with the average IOP from the following 3 months (post IOP) in each season. IOP elevation rate was defined as (vf IOP- pre IOP)/pre IOP x 100% and calculated for each season (paired t test). Additionally, the correlation between mean deviation (MD) and IOP elevation rate was evaluated (single regression analysis). Exclusion criteria were patients who received cataract surgery during this study or had a history of any previous glaucoma surgery. The automated visual field test was performed with a Humphrey field analyzer and the Central 30-2 FASTPAC threshold program. The average vf IOP was 14.5 +/- 2.5 mmHg, higher than pre IOP 13.8 +/- 2.4 mmHg (p field examination, especially in the winter but not in the summer.

Research on Energy-Saving Optimization for the Performance Parameters of Rural-Building Shape and Envelope by TRNSYS-GenOpt in Hot Summer and Cold Winter Zone of China

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Shilei Lu

2017-02-01

Full Text Available The aim of this paper is to optimize the building shape parameters and envelope parameters influencing the rural building energy consumption in cold winter and hot summer climate. Several typical models are established and optimized by integrated TRNSYS and GenOpt. Single-objective optimization has provided guidance to the multi-dimensional optimization. Building shape and envelope parameters are considered simultaneously by multi-dimensional optimization. Results of the optimization showed significant reduction in terms of EC (energy consumption. When O (building orientation was SW (south by west 10°, LWR (length-width ratio was 1.1, WWRS (window-wall ratio in south with the range of 0.6–0.8, ITE (insulation thickness of exterior wall and ITR (insulation thickness of roof was 0.05 m and 0.08 m respectively, the building had minimal energy consumption. The results also indicated that the optimal EWT (exterior window type was plastic single-frame Low-E insulating glazing filled with inert gas, and the optimal shape of building is Re (rectangle. An effective method was provided to optimize the design of the rural building for the purpose of reducing building energy consumption in cold winter and hot summer climate.

Titan's Emergence from Winter

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Flasar, F. Michael; Achterberg, Richard; Jennings, Donald; Schinder, Paul

2011-01-01

We summarize the changes in Titans thermal structure derived from Cassini CIRS and radio-occultation data during the transition from winter to early spring. Titan's surface, and middle atmosphere show noticeable seasonal change, whereas that in most of the troposphere is mated. This can be understood in terms of the relatively small radiative relaxation time in the middle atmosphere and much larger time scale in the troposphere. The surface exhibits seasonal change because the heat capacity in an annual skin depth is much smaller than that in the lowest scale height of the troposphere. Surface temperatures rise 1 K at raid and high latitudes in the winter northern hemisphere and cool in the southern hemisphere. Changes in in the middle atmosphere are more complicated. Temperatures in the middle stratosphere (approximately 1 mbar) increase by a few kelvin at mid northern latitudes, but those at high latitudes first increase as that region moves out of winter shadow, and then decrease. This probably results from the combined effect of increased solar heating as the suit moves higher in the sky and the decreased adiabatic warming as the sinking motions associated with the cross-equatorial meridional cell weaken. Consistent with this interpretation, the warm temperatures observed higher up at the winter polar stratopause cool significantly.

Variability of tracer transport in spring/summer Arctic stratosphere simulated by CESM-WACCM

Science.gov (United States)

Thiéblemont, Rémi; Matthes, Katja; Hansen, Felicitas; Huret, Nathalie

2014-05-01

Recent observational and modeling transport studies of Arctic stratospheric final warmings have shown that tropical/subtropical air can be transported to high latitudes and remain confined within a long-lived "frozen-in" anticyclone (FrIAC), embedded in the summer easterlies for several months. A climatology of these sporadic events has shown that their frequency of occurrence considerably increased over the last decade: among the nine cases detected over the period 1960-2011, five occurred between 2002 and 2011.Although a stratospheric favorable preconditioning for their occurrence were identified, the causes of such an increase are not yet understood. In this study, a chemistry climate model is used for the first time to investigate FrIACs characteristics and variability. Simulations were performed with the NCAR's Community Earth System Model (CESM), a coupled model system including an interactive ocean (POP2), land (CLM4), sea ice (CICE), and atmosphere (NCAR's Whole Atmosphere Community Climate Model (WACCM)). To detect low-latitude air masses characterizing FrIACs, daily 3-D output of temperature, horizontal wind and pressure are used to calculate the potential vorticity equivalent latitude (PVEL) distribution onto various isentropic levels in the range 700 K - 1200 K. Additionally, anticyclones are identified by using an algorithm designed to detect systematically vortex edges. To classify an event as a FrIAC, we require that the intrusion contains air masses from low-latitudes (below PVEL=40°N), reaches the polar region (beyond 60°N), and is collocated with an anticyclonic eddy. Among the 145 years analyzed (1955-2099), from a simulation with natural forcing conditions only, 20 FrIACs are found. They occur predominantly under a strong and abrupt winter-to-summer dynamical transitions which are driven by large planetary wave activity. FrIACs characteristics (i.e. spatial extent and duration), are overall consistent by comparing with FrIACs detected in ERA

Spring Chinook Salmon Interactions Indices and Residual/Precocial Monitoring in the Upper Yakima Basin, Annual Report 1998

International Nuclear Information System (INIS)

James, Brenda B.; Pearsons, Todd N.; McMichael, Geoffrey A.

1999-01-01

Select ecological interactions and spring chinook salmon residual/precocial abundance were monitored in 1998 as part of the Yakima/Klickitat Fisheries Project's supplementation monitoring program. Monitoring these variables is part of an effort to help evaluate the factors that contribute to, or limit supplementation success. The ecological interactions that were monitored were prey consumption, competition for food, and competition for space. The abundance of spring chinook salmon life-history forms that have the potential to be influenced by supplementation and that have important ecological and genetic roles were monitored (residuals and precocials). Residual spring chinook salmon do not migrate to the ocean during the normal emigration period and continue to rear in freshwater. Precocials are those salmon that precocially mature in freshwater. The purpose of sampling during 1998 was to collect baseline data one year prior to the release of hatchery spring chinook salmon which occurred during the spring of 1999. All sampling that the authors report on here was conducted in upper Yakima River during summer and fall 1998. The stomach fullness of juvenile spring chinook salmon during the summer and fall averaged 12%. The food competition index suggested that mountain whitefish (0.59), rainbow trout (0.55), and redside shiner (0.55) were competing for food with spring chinook salmon. The space competition index suggested that rainbow trout (0.31) and redside shiner (0.39) were competing for space with spring chinook salmon but mountain whitefish (0.05) were not. Age-0 spring chinook salmon selected a fairly narrow range of microhabitat parameters in the summer and fall relative to what was available. Mean focal depths and velocities for age 0 spring chinook salmon during the summer were 0.5 m ± 0.2 m and 0.26 m/s ± 0.19 m/s, and during the fall 0.5 m ± 0.2 m and 0.24 m/s ± 0.18 m/s. Among potential competitors, age 1+ rainbow trout exhibited the greatest degree

Springs-neaps cycles in daily total seabed light: Daylength-induced changes

Science.gov (United States)

Roberts, E. M.; Bowers, D. G.; Davies, A. J.

2014-04-01

In shallow, tidal seas, daily total seabed light is determined largely by the interaction of the solar elevation cycle, the tidal cycle in water depth, and any temporal variability in turbidity. Since tidal range, times of low water, and often turbidity vary in regular ways over the springs-neaps cycle, daily total seabed light exhibits cycles of the same periodicity. Corresponding cycles are likely to be induced in the daily total primary production of benthic algae and plants, particularly those light-limited specimens occupying the lower reaches of a sub-tidal population. Consequently, this effect is an important control on the growth patterns, depth distribution and survival of, for example, macroalgal forests and seagrass meadows. Seasonal changes in daylength exert an important additional control on these cycles, as they alter the fraction of the tidal and turbidity cycles occurring within daylight hours. Bowers et al. (1997) modelled this phenomenon numerically and predicted that for a site with low water at about midday and midnight at neaps tides, 6 am and 6 pm at springs, daily total seabed light peaks at neaps in winter, but the ‘sense' of the cycle ‘switches' so that it peaks at springs in summer - the longer daylength permits the morning and evening low water springs to contribute substantially to the daily total. Observations for such a site in North Wales (UK), presented in this paper, show that no such ‘switch' occurs, and neaps tides host the largest daily totals throughout the year. The predicted ‘switch' is not observed because turbidity increases generally at spring tides, and specifically at low water springs, both of which were not accounted for in the model. Observations at a second site in Brittany (France), diametrically opposite in terms of the times of low water at neaps and at springs, indicate a peak at springs throughout the year. Analytical tools are developed to calculate the percentage of daily total sea surface irradiance

Influence of finite-time Lyapunov exponents on winter precipitation over the Iberian Peninsula

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Garaboa-Paz, Daniel; Lorenzo, Nieves; Pérez-Muñuzuri, Vicente

2017-05-01

Seasonal forecasts have improved during the last decades, mostly due to an increase in understanding of the coupled ocean-atmosphere dynamics, and the development of models able to predict the atmosphere variability. Correlations between different teleconnection patterns and severe weather in different parts of the world are constantly evolving and changing. This paper evaluates the connection between winter precipitation over the Iberian Peninsula and the large-scale tropospheric mixing over the eastern Atlantic Ocean. Finite-time Lyapunov exponents (FTLEs) have been calculated from 1979 to 2008 to evaluate this mixing. Our study suggests that significant negative correlations exist between summer FTLE anomalies and winter precipitation over Portugal and Spain. To understand the mechanisms behind this correlation, summer anomalies of the FTLE have also been correlated with other climatic variables such as the sea surface temperature (SST), the sea level pressure (SLP) or the geopotential. The East Atlantic (EA) teleconnection index correlates with the summer FTLE anomalies, confirming their role as a seasonal predictor for winter precipitation over the Iberian Peninsula.

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.

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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.

Field and laboratory tests of etched track detectors for 222Rn: summer-vs-winter variations and tightness effects in Maine houses

International Nuclear Information System (INIS)

Hess, C.T.; Fleischer, R.L.; Turner, L.G.

1985-01-01

Effects of tightness of homes of bedrock character on indoor 222 Rn concentrations were sought in 70 homes in the state of Maine by means of four 6- to 8-month-long surveys over a 1.5-yr period. Laboratory experiments were also performed that document the reliability of the track etching system used for the measurements. In this survey the Rn in tight homes was on the average 3.5 times that in drafty ones, and areas with granitic bedrock led to homes having 2.3 times the Rn as for homes on chlorite-biotite-rich bedrock. Winter-to-summer ratios ranged from 0.5-7, and averaged 1.5, implying that surveys of individual homes require a full year of monitoring

An investigation of the role of winter and spring precipitation as drivers of streamflow in the Missouri River Headwaters using tree-ring reconstructions

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Frederick, S. E.; Woodhouse, C. A.; Martin, J. T.; Pederson, G. T.

2017-12-01

The Missouri River supplies water to over 3 million basin residents and is a driving force for the nation's agricultural and energy sectors. However, with changing climate and declining snowpack in western North America, seasonal water yields are becoming less predictable, revealing a gap in our understanding of regional hydroclimate and drivers of streamflow within the basin. By analyzing the relationship between seasonal precipitation and streamflow in the Missouri River Headwaters sub-basin, this study seeks to expand our knowledge based on the instrumental record alone. Here we present the first annually-resolved tree-ring reconstruction of spring precipitation for the Missouri River Headwaters. This reconstruction along with existing tree-ring reconstructions of April 1 snow-water equivalence (SWE) (Pederson et al. 2011) and natural streamflow (Martin, J.T. & Pederson, G.T., personal communication, June 2017) are used to test the feasibility of detecting a variable influence of winter and spring precipitation on streamflow over past centuries, and relative to the modern period. Initial analyses indicate that April 1 SWE is a significant control on streamflow, however, the April 1 SWE record does not fully account for anomalies observed in the streamflow record. This study therefore seeks to determine whether spring precipitation can account for some of this asynchronous variability observed between the April 1 SWE and streamflow records. Aside from improved understanding of the relationship between hydroclimate and streamflow in the headwaters of the Missouri River, our findings offer insights relating to changing contributions from snowmelt and spring precipitation, and long-term hydrologic variability and trends relevant to water resource management and planning efforts.

Genetic Architecture of Anther Extrusion in Spring and Winter Wheat

Directory of Open Access Journals (Sweden)

Quddoos H. Muqaddasi

2017-05-01

Full Text Available Hybrid wheat breeding is gaining prominence worldwide because it ensures higher and more static yield than conventionally bred varieties. The cleistogamous floral architecture of wheat (Triticum aestivum L. impedes anthers inside the floret, making it largely an inbreeder. For hybrid seed production, high anther extrusion is needed to promote cross pollination and to ensure a high level of pollen availability for the seed plant. This study, therefore, aimed at the genetic dissection of anther extrusion (AE in panels of spring (SP, and winter wheat (WP accessions by genome wide association studies (GWAS. We performed GWAS to identify the SNP markers potentially linked with AE in each panel separately. Phenotypic data were collected for 3 years for each panel. The average levels of Pearson's correlation (r among all years and their best linear unbiased estimates (BLUEs within both panels were high (r(SP = 0.75, P < 0.0001;r(WP = 0.72, P < 0.0001. Genotypic data (with minimum of 0.05 minor allele frequency applied included 12,066 and 12,191 SNP markers for SP and WP, respectively. Both genotypes and environment influenced the magnitude of AE. In total, 23 significant (|log10(P| > 3.0 marker trait associations (MTAs were detected (SP = 11; WP = 12. Anther extrusion behaved as a complex trait with significant markers having either favorable or unfavorable additive effects and imparting minor to moderate levels of phenotypic variance (R2(SP = 9.75−14.24%; R2 (WP = 9.44−16.98%. All mapped significant markers as well as the markers within their significant linkage disequilibrium (r2 ≥ 0.30 regions were blasted against wheat genome assembly (IWGSC1+popseq to find the corresponding genes and their high confidence descriptions were retrieved. These genes and their orthologs in Hordeum vulgare, Brachypodium distachyon, Oryza sativa, and Sorghum bicolor revealed syntenic genomic regions potentially involved in flowering-related traits. Moreover, the

Potentiometric surfaces, summer 2013 and winter 2015, and select hydrographs for the Southern High Plains aquifer, Cannon Air Force Base, Curry County, New Mexico

Science.gov (United States)

Collison, Jake

2016-04-07

Cannon Air Force Base (Cannon AFB) is located in the High Plains physiographic region of east-central New Mexico, about 5 miles west of Clovis, New Mexico. The area surrounding Cannon AFB is primarily used for agriculture, including irrigated cropland and dairies. The Southern High Plains aquifer is the principal source of water for Cannon AFB, for the nearby town of Clovis, and for local agriculture and dairies. The Southern High Plains aquifer in the vicinity of Cannon AFB consists of three subsurface geological formations: the Chinle Formation of Triassic age, the Ogallala Formation of Tertiary age, and the Blackwater Draw Formation of Quaternary age. The Ogallala Formation is the main water-yielding formation of the Southern High Plains aquifer. Groundwater-supplied, center-pivot irrigation dominates pumping from the Southern High Plains aquifer in the area surrounding Cannon AFB, where the irrigation season typically extends from early March through October. The U.S. Geological Survey has been monitoring groundwater levels in the vicinity of Cannon AFB since 1954 and has developed general potentiometric-surface maps that show groundwater flow from northwest to southeast in the study area. While previous potentiometric-surface maps show the general direction of groundwater flow, a denser well network is needed to show details of groundwater flow at a local scale. Groundwater levels were measured in 93 wells during summer 2013 and 100 wells during winter 2015.The summer and winter potentiometric-surface maps display the presence of what is interpreted to be a groundwater trough trending from the northwest to the southeast through the study area. This groundwater trough may be the hydraulic expression of a Tertiary-age paleochannel. Groundwater north of the trough flows in a southerly direction into the trough, and groundwater south of the trough flows in an easterly direction into the trough.During the 18-month period between summer 2013 and winter 2015, changes

Mechanical weed control in organic winter wheat

OpenAIRE

Euro Pannacci; Francesco Tei; Marcello Guiducci

2017-01-01

Three field experiments were carried out in organic winter wheat in three consecutive years (exp. 1, 2005-06; exp. 2, 2006- 07; exp. 3, 2007-08) in central Italy (42°57’ N - 12°22’ E, 165 m a.s.l.) in order to evaluate the efficacy against weeds and the effects on winter wheat of two main mechanical weed control strategies: i) spring tine harrowing used at three different application times (1 passage at T1, 2 passages at the time T1, 1 passage at T1 followed by 1 passage at T1 + 14 days) in t...

Seasonal trophic activity of the aquatic morphotype of Atelognathus patagonicus (Anura, Neobatrachia and prey availability in the littoral benthos of a permanent pond in Argentinean Patagonia

Directory of Open Access Journals (Sweden)

María Elena Cuello

2009-12-01

Full Text Available The diet of the aquatic morphotype of Atelognathus patagonicus was studied in frogs collected from the Laguna Verde pond (Laguna Blanca National Park, Neuquén, Argentina. The content of 35 gastrointestinal tracts of post-metamorphic specimens from November 2003 to April 2006 was related to the composition of the benthos in their microhabitat. Number, size, occurrence and relative importance of preys, diversity of the diet, trophic niche breadth and electivitywere estimated for each season of the year. The diet consisted of aquatic arthropods. The composition of both the benthos and the food (number and occurrence of organisms in the diet were dominated by the amphipod Hyalella sp. The relative importance (IRI of Hyalella sp. in the diet was over 99% in summer and autumn, and 100% in winter and spring. Diptera and Copepoda in summer, and Dytiscidae and Ostracoda in autumn, had seasonal IRI values ≤ 0.2%. Trophic niche breadth was very low in summer and autumn, and null (= 0 in winter and spring. The mean number of preys per individual was highest in spring (19 preys/frog and lowest in winter (4 preys/frog. Frogs continued with their trophic activity in winter, even when the surface of the pond was frozen. There is a correspondence between the frogs’ main food item and its presence in the benthos.

Spatiotemporal dynamics of snow cover based on multi-source remote sensing data in China

Science.gov (United States)

Huang, Xiaodong; Deng, Jie; Ma, Xiaofang; Wang, Yunlong; Feng, Qisheng; Hao, Xiaohua; Liang, Tiangang

2016-10-01

By combining optical remote sensing snow cover products with passive microwave remote sensing snow depth (SD) data, we produced a MODIS (Moderate Resolution Imaging Spectroradiometer) cloudless binary snow cover product and a 500 m snow depth product. The temporal and spatial variations of snow cover from December 2000 to November 2014 in China were analyzed. The results indicate that, over the past 14 years, (1) the mean snow-covered area (SCA) in China was 11.3 % annually and 27 % in the winter season, with the mean SCA decreasing in summer and winter seasons, increasing in spring and fall seasons, and not much change annually; (2) the snow-covered days (SCDs) showed an increase in winter, spring, and fall, and annually, whereas they showed a decrease in summer; (3) the average SD decreased in winter, summer, and fall, while it increased in spring and annually; (4) the spatial distributions of SD and SCD were highly correlated seasonally and annually; and (5) the regional differences in the variation of snow cover in China were significant. Overall, the SCD and SD increased significantly in south and northeast China, and decreased significantly in the north of Xinjiang province. The SCD and SD increased on the southwest edge and in the southeast part of the Tibetan Plateau, whereas it decreased in the north and northwest regions.

Investigating the impact of temporal and spatial variation in spring snow melt on summer soil respiration

Science.gov (United States)

John, G. P.; Papuga, S. A.; Wright, C. L.; Nelson, K.; Barron-Gafford, G. A.

2010-12-01

While soil respiration - the flux of carbon dioxide from the soil surface to the atmosphere - is the second largest terrestrial carbon flux, it is the least well constrained component of the terrestrial carbon cycle. This is in part because of its high variability in space and time that can become amplified under certain environmental conditions. Under current climate change scenarios, both summer and winter precipitation are expected to be altered in terrestrial ecosystems of the southwestern US. Precipitation magnitude and intensity influence soil moisture, which is a key control on ecosystem-scale respiration rates. Therefore understanding how changes in snow and rainfall translate to changes in soil moisture is critical to understanding climate change impacts on soil respiration processes. Our study took place within the footprint of a semiarid mixed-conifer flux measurement system on Mount Bigelow just north of Tucson, AZ. We analyzed images from three understory phenology cameras (pheno-cams) to identify areas that represented early and late snowmelt. Within the field of view of each of the three pheno-cams we established three early-melt and three late-melt soil respiration measurement “sites”. To understand the persistence of snowmelt conditions on summer soil respiration, we measured soil respiration, soil moisture, and soil temperature at all six sites on four days representing different summer periods (i.e. pre-monsoon, early monsoon, mid-monsoon, and late monsoon). Throughout the entire study period, at both early- and late-melt sites soil respiration was strongly correlated with amount of soil moisture, and was less responsive to temperature. Soil respiration generally increased throughout the rainy season, peaking by mid-monsoon at both early- and late-melt sites. Interestingly, early-melt sites were wetter than late-melt sites following rainfall occurring in the pre- and early monsoon. However, following rainfall occurring in the mid- to late

Influence of Atlantic SST anomalies on the atmospheric circulation in the Atlantic-European sector