Cytoskeletal Regulation Dominates Temperature-Sensitive Proteomic Changes of Hibernation in Forebrain of 13-Lined Ground Squirrels

PubMed Central

Hindle, Allyson G.; Martin, Sandra L.

2013-01-01

13-lined ground squirrels, Ictidomys tridecemlineatus, are obligate hibernators that transition annually between summer homeothermy and winter heterothermy – wherein they exploit episodic torpor bouts. Despite cerebral ischemia during torpor and rapid reperfusion during arousal, hibernator brains resist damage and the animals emerge neurologically intact each spring. We hypothesized that protein changes in the brain underlie winter neuroprotection. To identify candidate proteins, we applied a sensitive 2D gel electrophoresis method to quantify protein differences among forebrain extracts prepared from ground squirrels in two summer, four winter and fall transition states. Proteins that differed among groups were identified using LC-MS/MS. Only 84 protein spots varied significantly among the defined states of hibernation. Protein changes in the forebrain proteome fell largely into two reciprocal patterns with a strong body temperature dependence. The importance of body temperature was tested in animals from the fall; these fall animals use torpor sporadically with body temperatures mirroring ambient temperatures between 4 and 21°C as they navigate the transition between summer homeothermy and winter heterothermy. Unlike cold-torpid fall ground squirrels, warm-torpid individuals strongly resembled the homeotherms, indicating that the changes observed in torpid hibernators are defined by body temperature, not torpor per se. Metabolic enzymes were largely unchanged despite varied metabolic activity across annual and torpor-arousal cycles. Instead, the majority of the observed changes were cytoskeletal proteins and their regulators. While cytoskeletal structural proteins tended to differ seasonally, i.e., between summer homeothermy and winter heterothermy, their regulatory proteins were more strongly affected by body temperature. Changes in the abundance of various isoforms of the microtubule assembly and disassembly regulatory proteins dihydropyrimidinase-related protein and stathmin suggested mechanisms for rapid cytoskeletal reorganization on return to euthermy during torpor-arousal cycles. PMID:23951209

Evaluation of seasonality on total water intake, water loss and water balance in the general population in Greece.

PubMed

Malisova, O; Bountziouka, V; Panagiotakos, D Β; Zampelas, A; Kapsokefalou, M

2013-07-01

Water balance is achieved when water intake from solid and fluid foods and drinking water meets water losses, mainly in sweat, urine and faeces. Seasonality, particularly in Mediterranean countries that have a hot summer, may affect water loss and consequently water balance. Water balance has not been estimated before on a population level and the effect of seasonality has not been evaluated. The present study aimed to compare water balance, intake and loss in summer and winter in a sample of the general population in Greece. The Water Balance Questionnaire (WBQ) was used to evaluate water balance, estimating water intake and loss in summer (n = 480) and in winter (n = 412) on a stratified sample of the general population in Athens, Greece. In winter, mean (SD) water balance was -63 (1478) mL/day(-1) , mean (SD)water intake was 2892 (987) mL/day(-1) and mean (quartile range) water loss was 2637 (1810-3922) mL/day(-1) . In summer, mean (SD) water balance was -58 (2150) mL/day(-1) , mean (SD) water intake was 3875 (1373) mL/day(-1) and mean (quartile range) water loss was 3635 (2365-5258) mL/day(-1) . Water balance did not differ between summer and winter (P = 0.96); however, the data distribution was different; in summer, approximately 8% more participants were falling in the low and high water balance categories. Differences in water intake from different sources were identified (P < 0.05). Water balance in summer and winter was not different. However, water intake and loss were approximately 40% higher in summer than in winter. More people were falling in the low and high water balance categories in summer when comparing the distribution on water balance in winter. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

Seasonal and annual precipitation time series trend analysis in North Carolina, United States

NASA Astrophysics Data System (ADS)

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 Oscillation indices for North Carolina.

Striped bass annual site fidelity and habitat utilization in J. Strom Thurmond Reservoir, South Carolina-Georgia

USGS Publications Warehouse

Young, S.P.; Isely, J.J.

2002-01-01

Forty-eight adult striped bass Morone saxatilis (3.2-19.1 kg) were captured by electrofishing in the tailrace of Richard B. Russell Dam and in the upper reaches of two major tributaries; they were implanted with temperature-sensitive radio transmitters and tracked approximately bimonthly for 20 months. As J. Strom Thurmond Reservoir downstream from the dam became thermally stratified in May, fish vacated the tributaries. From June to October, all striped bass were found within the reservoir's historical Savannah River channel. By August, most of the instrumented fish were found in the upper section of the reservoir, where optimal habitat was available throughout the summer owing to cool, artificially oxygenated hypolimnetic discharges from Richard B. Russell Dam. In mid-October the reservoir destratified, and fish dispersed from their up-reservoir summering areas and redistributed themselves throughout the reservoir. During early winter, the striped bass returned to tributary habitat or down-reservoir areas and generally used these locations throughout the winter. The fish exhibited a high degree of site fidelity to their summering areas, source tributaries (after fall dispersal and throughout the winter), and spring spawning areas. Mean movement rates were highest in the spring and fall, corresponding to the migration from tributaries in May and the return migration after fall dispersal. Mean movement rates were lowest in summer and winter, corresponding to the periods of high fidelity to summering and wintering areas. The average monthly temperatures and dissolved oxygen concentrations in areas used by striped bass were 19.0-20.4??C and 4.86-6.44 mg/L during May-October, which corresponded to average monthly habitat suitability index values of 0.76-0.98. Striped bass avoided temperatures above 25.1??C and dissolved oxygen concentrations less than 2.3 mg/L.

Basin-scale variation in the spatial pattern of fall movement of juvenile Coho Salmon in the West Fork Smith River, Oregon

Treesearch

Dalton J. Hance; Lisa M. Ganio; Kelly M. Burnett; Joseph L. Ebersole

2016-01-01

For several species of salmonids, Oncorhynchus and Salvelinus spp., inhabiting Pacific coastal temperate streams, juvenile fish have been recorded moving between main-stem and tributary habitats during the transition from the summer dry season to the winter wet season. Movement connecting summer and winter habitats may be particularly important for...

Seasonal variation of energy reserves and reproduction in neotropical free-tailed bats Molossus molossus (Chiroptera: Molossidae).

PubMed

Barros, M S; Morais, D B; Araújo, M R; Carvalho, T F; Matta, S L P; Pinheiro, E C; Freitas, M B

2013-08-01

Seasonal variation is a key factor regulating energy metabolism and reproduction in several mammals, including bats. This study aimed to track seasonal changes in the energy reserves of the insectivorous bat Molossus molossus associated with its reproductive cycle. Adult males were collected during the four neotropical annual seasons in Viçosa - MG, Brazil. Blood and tissues were collected for metabolic analysis and testes were removed for histology and morphometry. Our results show that liver and breast muscle glycogen concentrations were significantly lower in winter. The adiposity index was significantly higher in the fall compared to winter and spring. Seminiferous tubules were greater in diameter in animals captured in fall and winter, indicating a higher investment in spermatic production during these seasons. The percentage of Leydig cells was higher in summer compared to fall and winter. We suggest that M. molossus presents a type of seasonal reproduction with two peaks of testicular activity: one in fall, with higher sperm production (spermatogenesis), and another in summer, with higher hormone production (steroidogenesis). The metabolic pattern may be associated with reproductive events, especially due to the highest fat storage observed in the fall, which coincides with the further development of the seminiferous tubules.

Habitat use and movement patterns by adult saugers from fall to summer in an unimpounded small-river system

USGS Publications Warehouse

Kuhn, K.M.; Hubert, W.A.; Johnson, K.; Oberlie, D.; Dufek, D.

2008-01-01

The Little Wind River drainage in Wyoming is a relatively small unimpounded river system inhabited by native saugers Sander canadensis. Radio telemetry was used to assess habitat use and movement patterns by adult saugers in the river system from fall through early summer. Fifty-four adult saugers were captured during fall 2004, surgically implanted with radio transmitters, and tracked through mid-July 2005. Tagged saugers selected large and deep pools. Such pools were abundant throughout the Little Wind River system and led to saugers being widely dispersed from fall to early spring. During fall, winter, and early spring, tagged saugers remained sedentary and moved short distances among pools in close proximity to each other. Longer movements by tagged saugers occurred from mid-spring to early summer, and were associated with both upstream and downstream movements to and from two river segments believed to be used for spawning. During early summer, most saugers returned to locations where they had been tagged the previous fall and had spent the winter. Our results provide evidence that preservation of the sauger fishery in the Wind River system will depend on maintaining fish passage throughout the portion of the watershed inhabited by saugers and preserving natural fluvial processes that maintain large and deep pools. ?? Copyright by the American Fisheries Society 2008.

Seasonal surface circulation, temperature, and salinity in Prince William Sound, Alaska

NASA Astrophysics Data System (ADS)

Musgrave, David L.; Halverson, Mark J.; Scott Pegau, W.

2013-02-01

Salinity, temperature, and depth profiles from 1973 to 2010 were used to construct a seasonal climatology of surface temperature, surface salinity, mixed layer depth (MLD), potential energy of mixing, and surface geostrophic circulation in Prince William Sound (PWS) and the adjacent Gulf of Alaska. Surface salinity is greatest in winter and least in summer due to the influence of increased freshwater runoff in summer. It is generally lowest in the northwest and highest in the Gulf of Alaska. The surface temperature is lowest in the winter and highest in the summer when surface heating is greatest, with little spatial variability across the Sound. The MLD is deepest in winter (9-27 m) and shallowest in summer (4-5 m). The work by winds was estimated from meteorological buoy data in central PWS and compared to the potential energy of mixing of the upper water column. The potential depth to which winds mix the upper water column was generally consistent with the MLD. The surface geostrophic circulation in the central Sound has: a southerly flow in the western central Sound in the winter; a closed, weak anticyclonic cell in spring; a closed, cyclonic cell in the summer; an open, cyclonic circulation in the fall. In the western passages, a southerly flow occurs in spring, summer, and fall. These results have important implications for oil spill response in PWS, the use of oil dispersants, and for comparison to numerical studies.

Copepod community succession during warm season in Lagoon Notoro-ko, northeastern Hokkaido, Japan

NASA Astrophysics Data System (ADS)

Nakagawa, Yoshizumi; Ichikawa, Hideaki; Kitamura, Mitsuaki; Nishino, Yasuto; Taniguchi, Akira

2015-06-01

Lagoon Notoro-ko, located on the northeastern coast of Hokkaido, Japan, and connected to the Okhotsk Sea by a human-made channel, is strongly influenced by local hydrography, as water masses in the lagoon are seasonally influenced by the Soya Warm Current and the East Sakhalin Current. We here report on the succession of copepod communities during the warm season in relation to water mass exchange. Copepods were categorized into four seasonal communities (spring/early-summer, mid-summer, late-summer/fall, and early-winter) via a cluster analysis based on Bray-Curtis similarities. Spring/early-summer and early-winter communities were characterized by the temperate-boreal calanoid Pseudocalanus newmani, comprising 34.9%-77.6% of the total abundance of copepods during times of low temperature/salinity, as influenced by the prevailing East Sakhalin Current. Late-summer/fall communities were characterized by the neritic warm-water calanoid Paracalanus parvus s.l., comprising 63.9%-96.3% of the total abundance, as influenced by the Soya Warm Current. Mid-summer communities comprised approximately equal abundances of P. parvus, Eurytemora herdmani, Scolecithricella minor, and Centropages abdominalis (12.8%-28.2%); this community is transitional between those of the spring/early-summer and late-summer/fall. Copepod community succession in Lagoon Notoro-ko can be largely explained by seasonal changes in water masses.

Review of the circulation in the Beibu Gulf, South China Sea

NASA Astrophysics Data System (ADS)

Gao, Jingsong; Wu, Guidan; Ya, Hanzheng

2017-04-01

Although Beibu Gulf holds a significant geographical location and is rich in fishery resources, it has attracted only limited attention from researchers in recent decades. This study summarizes the conclusions based on the observations and model results regarding the circulation and cold water mass in the Beibu Gulf to provide a reference for further research. Affected by wind and density gradient, the spring circulation may be gulf-scale cyclonic and nested with an enclosed cyclonic gyre in the northern gulf and unclosed cyclonic gyre in the southern gulf. Meanwhile, the mechanisms of summer circulation remain controversial. Along with the results of a new numerical model, historical observations suggest that summer circulation is cyclonic and anticyclonic in the northern and southern gulfs, respectively. The northern and southern gulfs are mainly influenced by wind stress curl and South China Sea current, respectively. Similarly, although different views regarding the structure of winter circulation have been presented, a large amount of evidence supports the existence of two cyclonic gyres in the northern and southern gulfs. In addition, a southwestward current off the northwestern coast of Hainan Island is present. The circulation structure in the fall is similar to that in winter. However, the cyclonic gyre in the southern Gulf has a greater tendency to intrude northwards into the Beibu Gulf in fall than in winter, and the currents off the coast of Vietnam and the northwestern coast of Hainan Island are weaker in fall than those in winter. Most studies indicate that winter boreal circulation is driven by the monsoon wind. The most recent observations and model results suggest that the current in the Qiongzhou Strait (QS) is eastward on certain days in the boreal summer and is affected by the difference between the sea levels of the two ends of the QS and tidal rectification. Correspondingly, the volume transport is approximately -0.1 Sv (minus sign represents westward) in spring and from -0.1 to -0.4 Sv in boreal winter. By contrast, the volume transport in summer remains controversial. The cold water mass in the Beibu Gulf is generated locally in spring, matures in summer, and disappears in fall. Heat flux and wind dominate the formation of the cold water mass, and tidal mixing and topographic effects influence the variations in the cold water mass.

Spatiotemporal dynamics of snow cover based on multi-source remote sensing data in China

NASA Astrophysics Data System (ADS)

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.

Chronic environmental stress enhances tolerance to seasonal gradual warming in marine mussels

PubMed Central

Múgica, Maria; Izagirre, Urtzi; Sokolova, Inna M.

2017-01-01

In global climate change scenarios, seawater warming acts in concert with multiple stress sources, which may enhance the susceptibility of marine biota to thermal stress. Here, the responsiveness to seasonal gradual warming was investigated in temperate mussels from a chronically stressed population in comparison with a healthy one. Stressed and healthy mussels were subjected to gradual temperature elevation for 8 days (1°C per day; fall: 16–24°C, winter: 12–20°C, summer: 20–28°C) and kept at elevated temperature for 3 weeks. Healthy mussels experienced thermal stress and entered the time-limited survival period in the fall, became acclimated in winter and exhibited sublethal damage in summer. In stressed mussels, thermal stress and subsequent health deterioration were elicited in the fall but no transition into the critical period of time-limited survival was observed. Stressed mussels did not become acclimated to 20°C in winter, when they experienced low-to-moderate thermal stress, and did not experience sublethal damage at 28°C in summer, showing instead signs of metabolic rate depression. Overall, although the thermal threshold was lowered in chronically stressed mussels, they exhibited enhanced tolerance to seasonal gradual warming, especially in summer. These results challenge current assumptions on the susceptibility of marine biota to the interactive effects of seawater warming and pollution. PMID:28333994

Cultural variation in seasonal depression: cross-national differences in winter versus summer patterns of seasonal affective disorder.

PubMed

Kasof, Joseph

2009-05-01

Research suggests that two dimensions of national culture, individualism-collectivism and power distance, predict affective responses to the seasonally varying levels of ambient sunlight that may underlie regular cycles of mood and behavior in Seasonal Affective Disorder (SAD). Specifically, negative affect is predicted by the diminished sunlight of fall-winter in countries higher in individualism and lower in power distance, and by the increased sunlight of spring-summer in countries lower in individualism and higher in power distance. This study tests whether individualism correlates positively, and power distance negatively, with the frequency of winter-SAD relative to that of summer-SAD. A search for studies reporting frequencies of both winter-SAD and summer-SAD identified 55 samples encompassing 18 countries and 38,408 participants, including 1931 with SAD. The frequency of winter-SAD, relative to that of summer-SAD, correlated positively with individualism (r=.67, p=.001) and negatively with power distance (r=-.72, p=.0001). Countries in which winter-SAD was more common than summer-SAD were significantly more individualistic and less power-distant than countries in which summer-SAD was more common than winter-SAD. Results survived various tests of threats to validity. The study is limited by the quantity, quality, diversity, and representativeness of the research under review and by its correlational design. Individualism and power distance are strongly related to the relative prevalence of winter-SAD and summer-SAD. Culture may play an important but previously overlooked role in the etiology of SAD.

A method of evaluating effects of antecedent precipitation on duststorms and its application to Yuma, Arizona, 1981-1988

USGS Publications Warehouse

MacKinnon, D.J.; Elder, D.F.; Helm, P.J.; Tuesink, M.F.; Nist, C.A.

1990-01-01

Precipitation causes several short- and long-term effects on wind-induced surface erodibility and subsequent dust emission. Among the principal effects considered by this paper are soil moisture, soil crusts, and vegetation. A quantitative method is developed to assess these effects using differences between the potential and the actual amounts of dust emitted from dust sources as inferred from surface meteorological measurements obtained downwind from those sources. The results of this assessment must be interpreted with caution, however, when the size and location of dust sources are unknown. Using meteorological data recorded near Yuma, Arizona at the Yuma Marine Corps Air Station (YMCAS), the method is applied to calculate the potential and actual amounts of dust emitted from upwind dust sources during the spring and fall/winter seasons between January 1, 1981 and May 31, 1988. (Spring is considered to be the period between February 1 and May 31; fall/winter, between October 1 and January 31.) Because summer precipitation is intermittent and wind patterns are localized, summer meteorological data are not used to evaluate regional correlations between precipitation and dust storms. For the period between 1981 and 1988, a correlation of -0.60 was found between fall/winter precipitation and the actual amount of dust emitted from sources upwind of YMCAS during the following spring. A particularly strong reduction in dust emission was noted during the springs of 1983 and 1984 following the start of an 'El Nino event' in fall/winter 1982. Photographs taken at a geological and meteorological data-collection (Geomet) site, located in the natural desert 25 km southeast of YMCAS, show a correspondence between increased antecedent precipitation recorded at the site and increased vegetation. Whereas the annual precipitation totals at YMCAS and the Geomet site from the beginning of 1982 through 1984 are high, their seasonal totals, especially during the fall/winter seasons, are disparate. This fall/winter precipitation disparity may account for evidence suggesting that significant vegetation growth occurred at dust sources upwind of YMCAS by spring 1983, but that such growth did not occur at the Geomet site until fall/ winter of 1983. Spatial inhomogeneity in fall/winter precipitation probably contributed to the relatively low correlation (-0.60) between fall/winter precipitation recorded at YMCAS and the actual amount of dust emitted from upwind sources during the following spring. ?? 1990 Kluwer Academic Publishers.

Atmospheric Pollution and Greenhouse Emissions over 14 Largest Megacities of the World

NASA Astrophysics Data System (ADS)

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.

Wave energetics of the southern hemisphere of Mars

NASA Astrophysics Data System (ADS)

Battalio, Michael; Szunyogh, Istvan; Lemmon, Mark

2018-07-01

An assessment of the energetics of transient waves in the southern hemisphere of Mars is presented using the Mars Analysis Correction Data Assimilation (MACDA) dataset (v1.0) and the eddy kinetic energy equation. The dataset is divided into four representative periods covering the summer and winter solstices, a late fall period, and an early spring period for three Mars years. Spring eddies are the most intense, with eddies during the fall being less intense due to a marginally more stable mean-temperature profile and reduced recirculation of ageostrophic geopotential fluxes compared to the spring. Eddy kinetic energy during winter is reduced in intensity as a result of the winter solstitial pause in wave activity, and eddy kinetic energy during the summer is limited. Baroclinic energy conversion acts as a source in fall and spring but disappears during the winter as a result of a stabilized vertical temperature profile. Barotropic energy conversion acts as both a source and a sink of eddy kinetic energy, being most positive during the solstitial pause. Eddies take a northwest to southeast track across the southern highlands in the fall but have a more zonal track in the spring due to stronger eddy kinetic energy advection. Wave energetics is less intense in the southern compared to the northern hemisphere as a result of a shallower baroclinically unstable vertical profile.

Spatial patterns of drought persistence in East China

NASA Astrophysics Data System (ADS)

Meng, L.; Ford, T.

2017-12-01

East China has experienced a number of severe droughts in recent decades. Understanding the characteristics of droughts and their persistence will provide operational guidelines for water resource management and agricultural production. This study uses a logistic regression model to measure the probability of drought occurrence in the current season given the previous season's Standardized Precipitation Index (SPI) and Southern Oscillation Index (SOI) as well as drought persistence. Results reveal large spatial and seasonal variations in the relationship between the previous season's SPI and the drought occurrence probability in a given season. The drought persistence averaged over the entire study area for all the four seasons is approximately 34% with large variations from season to season and from region to region. The East and Northeast regions have the largest summer drought persistence ( 40%) and lowest fall drought persistence ( 28%). The spatial pattern in winter and spring drought persistence is dissimilar with stronger winter and weaker spring drought persistence in the Southwest and Northeast relative to other regions. Logistic regression analysis indicates a stronger negative relationship in summer-to-fall (or between fall drought occurrence and summer SPI) than other inter-season relationships. This study demonstrates that the impact of previous season SPI and SOI on current season drought varies substantially from region to region and from season to season. This study also shows stronger drought persistence in summer than in other seasons. In other words, the probability of fall drought occurrence is closely related to summer moisture conditions in the East China.

Cow and calf weight trends on mountain summer range.

Treesearch

Jon M. Skovlin

1962-01-01

Mountain range furnishes the bulk of summer forage for commercial cow-calf operations in northeastern Oregon. Herds maintained on valley range and pasture during winter and spring months are annually trailed to mountain ranges and remain there until calves are ready for fall markets (fig. 1).

Source characterization of fine and coarse particles at the East Mediterranean coast

NASA Astrophysics Data System (ADS)

Mamane, Yaacov; Perrino, Cinzia; Yossef, Osnat; Catrambone, Maria

Fine and coarse atmospheric particles were collected in Ashdod—a midsize industrial city on the southeastern Mediterranean coast, and in Gedera—a rural site, to characterize ambient particles and to determine their long-range transport during two major seasons—winter and summer. Manual PM2.5 and PM10 samplers, dichotomous samplers, continuous automated PM10 samplers, and denuders were used to sample particulate and gaseous pollutants. Fine and coarse concentrations in Ashdod were 21.2 and 39.6 μg m -3, and 23.9 and 30.5 μg m -3 in the fall-winter and summer campaigns, respectively. Crustal material, as calcites or dolomites mixed with silicates, dominated the coarse fraction and also the fine fraction on dusty days. In the fall-winter, S, P, and Ni were coupled with minerals. Coarse Ni was associated with crustal material during dust storms, while P originated from shipping and deposition of phosphates in the urban area around. Sulfates dominated the fine fractions in the summer season averaging 12 μg m -3. Multivariate analysis indicated that S was associated with As and Se, V and Ni, both associated with heavy fuel combustion, and Zn and Pb. In winter, those mixed sources were local, but in summer they were part of long-range transport. In the fall-winter, Zn and Pb were strongly associated with Mn, Ga, and Cu—elements emitted from either traffic or metal processing plants. Although the influence of crustal material on both size fractions was significant, most heavy metals were associated with PM2.5. Higher concentrations were linked to a larger number of particles in this fraction, to a larger surface area available for biochemical reaction [Harrison, R., Shi, J., Xi, S., Khan, A., Mark, D., Kinnersley, R., Yin, J., Philos, T., 2000. Measurement of number, mass and size distribution of particles in the atmosphere. Philosophical Transactions of the Royal Society 358, 2567-2579], and finally to a larger concern in regards to health effects.

Influence of season of lambing on gastrointestinal nematode infection of lambs

USDA-ARS?s Scientific Manuscript database

Gastrointestinal nematodes (GIN) are a major constraint to sheep production, especially during the summer when the conditions for Haemonchus contortus are ideal. GIN infection is minimal during the winter, but there is little known about differences in GIN control between fall born and winter born l...

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

USGS Publications Warehouse

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.

Seasonal variation of columnar aerosol optical properties and radiative forcing over Beijing, China

NASA Astrophysics Data System (ADS)

Yu, Xingna; Lü, Rui; Liu, Chao; Yuan, Liang; Shao, Yixing; Zhu, Bin; Lei, Lu

2017-10-01

Long-term seasonal characteristics of aerosol optical properties and radiative forcing at Beijing (during March 2001-March 2015) were investigated using a combination of ground-based Sun/sky radiometer retrievals from the AERONET and a radiative transfer model. Aerosol optical depth (AOD) showed a distinct seasonal variation with higher values in spring and summer, and relatively lower values in fall and winter. Average Angstrom exponent (AE) in spring was lower than other seasons, implying the significant impact of dust episodes on aerosol size distribution. AE mainly distributed between 1.0 and 1.4 with an obvious uni-peak pattern in each season. The observation data showed that high AODs (>1.0) were clustered in the fine mode growth wing and the coarse mode. Compared to AOD, seasonal variation in single scattering albedo (SSA) showed an opposite pattern with larger values in summer and spring, and smaller ones in winter and fall. The highest volume size distribution and median radius of fine mode particles occurred in summer, while those of coarse mode particles in spring. The averaged aerosol radiative forcing (ARF) at the top of the atmosphere (TOA) in spring, summer, fall and winter were -33 ± 22 W m-2, -35 ± 22 W m-2, -28 ± 20 W m-2, and -24 ± 23 W m-2 respectively, and these differences were mainly due to the SSA seasonal variation. The largest positive ARF within atmosphere occurred in spring, implying strong warming in the atmosphere. The low heating ratio in summer was caused by the increase in water vapor content, which enhanced light scattering capacity (i.e., increased SSA).

Seasonal and longitudinal distributions of atmospheric water-soluble dicarboxylic acids, oxocarboxylic acids, and α-dicarbonyls over the North Pacific

NASA Astrophysics Data System (ADS)

Bikkina, Srinivas; Kawamura, Kimitaka; Imanishi, Katsuya; Boreddy, S. K. R.; Nojiri, Yukihiro

2015-05-01

In order to assess the seasonal variability of atmospheric abundances of dicarboxylic acids, oxocarboxylic acids, and α-dicarbonyls over the North Pacific and Sea of Japan, aerosol samples were collected along the longitudinal transacts during six cruises between Canada and Japan. The back trajectory analyses indicate that aerosol samples collected in winter and spring are influenced by the East Asian outflow, whereas summer and fall samples are associated with the pristine maritime air masses. Molecular distributions of water-soluble organics in winter and spring samples show the predominance of oxalic acid (C2) followed by succinic (C4) and malonic acids (C3). In contrast, summer and fall marine aerosols are characterized by the predominance of C3 over C4. Concentrations of dicarboxylic acids were higher over the Sea of Japan than the North Pacific. With a lack of continental outflow, higher concentrations during early summer are ascribed to atmospheric oxidation of organic precursors associated with high biological activity in the North Pacific. This interpretation is further supported by the high abundances of azelaic acid, which is a photochemical oxidation product of biogenic unsaturated fatty acids, over the Bering Sea in early summer when surface waters are characterized by high biological productivity. We found higher ratios of oxalic acid to pyruvic and glyoxylic acids (C2/Pyr and C2/ωC2) and glyoxal and methylglyoxal (C2/Gly and C2/MeGly) in summer and fall than in winter and spring, suggesting a production of C2 from the aqueous-phase oxidation of oceanic isoprene. In this study, dicarboxylic acids account for 0.7-38% of water-soluble organic carbon.

Distribution and migration chronology of Eastern population sandhill cranes

USGS Publications Warehouse

Fronczak, David L.; Andersen, David; Hanna, Everett E.; Cooper, Thomas R.

2017-01-01

The Eastern Population (EP) of greater sandhill cranes (Antigone canadensis tabida; cranes) is expanding in size and geographic range. Little information exists regarding the geographic extent of breeding, migration, and wintering ranges, migration chronology, or use of staging areas for cranes in the EP. To obtain these data, we attached solar global positioning system (GPS) platform transmitting terminals (PTTs) to 42 sandhill cranes and monitored daily locations from December 2009 through August 2014. On average, tagged cranes settled in summer areas during late‐March in Minnesota (7%), Wisconsin (29%), Michigan, USA (21%), and Ontario, Canada (38%) and arrived at their winter terminus beginning mid‐December in Indiana (15%), Kentucky (3%), Tennessee (45%), Georgia (5%), and Florida (32%). Cranes initiated spring migration beginning mid‐February to their respective summer areas on routes similar to those used during fall migration. Twenty‐five marked cranes returned to the same summer area after a second spring migration, of which 19 (76%) settled <3 km from the estimated mean center of the summer area of the previous year. During the 2010–2012 United States Fish and Wildlife Service (USFWS) Cooperative Fall Abundance Survey for cranes in the EP, we estimated that approximately 29–31% of cranes that summered in both Wisconsin and the Lower Peninsula of Michigan were not in areas included in the survey. The information we collected on crane movements provides insight into distribution and migration chronology that will aid in assessment of the current USFWS fall survey. In addition, information on specific use sites can assist state and federal managers to identify and protect key staging and winter areas particularly during current and future recreational harvest seasons.

Assessing net community production in a glaciated Alaskan fjord

NASA Astrophysics Data System (ADS)

Reisdorph, S. C.; Mathis, J. T.

2015-09-01

The impact of deglaciation in Glacier Bay has been observed to seasonally influence the biogeochemistry of this marine system. The influence from surrounding glaciers, particularly tidewater glaciers, has the potential to affect the efficiency and structure of the marine food web within Glacier Bay. To assess the magnitude and the spatial and temporal variability in net community production in a glaciated fjord, we measured dissolved inorganic carbon, inorganic macronutrients, dissolved oxygen, and particulate organic carbon between July 2011 and July 2012 in Glacier Bay, Alaska. High net community production rates were observed across the bay (~ 54 to ~ 81 mmol C m-2 d-1) between the summer and fall of 2011. However, between the fall and winter, as well as between the winter and spring of 2012, air-sea fluxes of carbon dioxide and organic matter respiration made net community production rates negative across most of the bay as inorganic carbon and macronutrient concentrations returned to pre-bloom levels. The highest organic carbon production occurred within the west arm between the summer and fall of 2011 with ~ 4.5 × 105 kg C d-1. Bay-wide, there was carbon production of ~ 9.2 × 105 g C d-1 between the summer and fall. Respiration and air-sea gas exchange were the dominant drivers of carbon chemistry between the fall and winter of 2012. The substantial spatial and temporal variability in our net community production estimates may reflect glacial influences within the bay, as meltwater is depleted in macronutrients relative to marine waters entering from the Gulf of Alaska in the middle and lower parts of the bay. Further glacial retreat will likely lead to additional modifications in the carbon biogeochemistry of Glacier Bay, with unknown consequences for the local marine food web, which includes many species of marine mammals.

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 leftmore » 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 downstream areas. Juveniles tagged as they left the upper rearing areas of Catherine Creek in fall and that overwintered in areas downstream were detected in the hydrosystem at a lower rate than fish tagged during winter in the upper rearing areas, indicating a higher overwinter survival in the upper rearing areas. Juveniles tagged as they left the upper rearing areas of the Lostine River in fall and that overwintered in areas downstream were detected in the hydrosystem at a similar rate to fish tagged during winter in the upper rearing areas, indicating similar overwinter survival in the upstream and downstream areas. Chinook salmon parr were generally associated with low velocity habitat types, that is pools, during both winter and summer in the Lostine River.« less

Insolation at Carterville, Illinois

Treesearch

Peter Y. S. Chen

1981-01-01

Insolation measured with a precision spectral pyranometer, was recorded near Carterville, Illinois, for 1 year. the pyranometer was tilted at an angle of 25 degrees in summer, 50 degrees in winter, and 37.5 degrees in spring and fall. the insolation measured in winter was found to be significantly larger than the insolation estimated on a horizontal surface.

Forest disturbance type differentially affects seasonal moose forage

Treesearch

R.A. Lautenschlager; Hewlette S. Crawford; Martin R. Stokes; Timothy L. Stone

1997-01-01

We examined the effects of forest disturbance on forage availability, moose (Alces alces) seasonal forage selection, and predicted in vivo digestibility in eastern Maine. Wet-mass estimates and dry-mass conversions of species consumed by 3 tamed moose were made throughout the year (late winter, early spring, late spring, summer, fall, early winter)...

What Are Solid Fats?

MedlinePlus

... Menus Seasonal Winter Spring Summer Fall Food Waste Food Safety Newsroom Dietary ... Solid fats are fats that are solid at room temperature, like beef fat, butter, and shortening. Solid fats mainly come ...

Intrinsic circannual regulation of brown adipose tissue form and function in tune with hibernation

PubMed Central

Hindle, Allyson G.

2013-01-01

Winter hibernators repeatedly cycle between cold torpor and rewarming supported by nonshivering thermogenesis in brown adipose tissue (BAT). In contrast, summer animals are homeotherms, undergoing reproduction, growth, and fattening. This life history confers variability to BAT recruitment and activity. To address the components underlying prewinter enhancement and winter activation, we interrogated the BAT proteome in 13-lined ground squirrels among three summer and five winter states. We also examined mixed physiology in fall and spring individuals to test for ambient temperature and seasonal effects, as well as the timing of seasonal transitions. BAT form and function differ circannually in these animals, as evidenced by morphology and proteome dynamics. This intrinsic pattern distinguished homeothermic groups and early vs. late winter hibernators. Homeothermic variation derived from postemergence delay in growth and substrate biosynthesis. The heterothermic proteome varied less despite extreme winter physiological shifts and was optimized to exploit lipids by enhanced fatty acid binding, β-oxidation, and mitochondrial protein translocation. Surprisingly, ambient temperature did not affect the BAT proteome during transition seasons; rather, the pronounced summer-winter shift preceded environmental changes and phenotypic progression. During fall transition, differential regulation of two fatty acid binding proteins provides further evidence of recruitment and separates proteomic preparation from successful hibernation. Abundance of FABP4 correlates with torpor bout length throughout the year, clarifying its potential function in hibernation. Metabolically active BAT is a target for treating human obesity and metabolic disorders. Understanding the hibernator's extreme and seasonally distinct recruitment and activation control strategies offers untapped potential to identify novel, therapeutically relevant regulatory pathways. PMID:24326419

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

PubMed

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.

Seasonal movement, residency, and migratory patterns of Wilson's Snipe (Gallinago delicata)

USGS Publications Warehouse

Cline, Brittany B.; Haig, Susan M.

2011-01-01

Cross-seasonal studies of avian movement establish links between geographically distinct wintering, breeding, and migratory stopover locations, or assess site fidelity and movement between distinct phases of the annual cycle. Far fewer studies have investigated individual movement patterns within and among seasons over an annual cycle. Within western Oregon's Willamette Valley throughout 2007, we quantified intra- and interseasonal movement patterns, fidelity (regional and local), and migratory patterns of 37 radiomarked Wilson's Snipe (Gallinago delicata) to elucidate residency in a region of breeding- and wintering-range overlap. Telemetry revealed complex regional population structure, including winter residents (74%), winter transients (14%), summer residents (9%), and one year-round resident breeder (3%). Results indicated a lack of connectivity between winter and summer capture populations, some evidence of partial migration, and between-season fidelity to the region (winter-resident return; subsequent fall). Across seasons, the extent of movements and use of multiple wetland sites suggested that Wilson's Snipe were capable of exploratory movements but more regularly perceived local and fine-scale segments of the landscape as connected. Movements differed significantly by season and residency; individuals exhibited contracted movements during late winter and more expansive movements during precipitation-limited periods (late spring, summer, fall). Mean home-range size was 3.5 ± 0.93 km2 (100% minimum convex polygon [MCP]) and 1.6 ± 0.42 km2 (95% fixed kernel) and did not vary by sex; however, home range varied markedly by season (range of 100% MCPs: 1.04–7.56 km2). The results highlight the need to consider seasonal and interspecific differences in shorebird life histories and space-use requirements when developing regional wetland conservation plans.

AmeriFlux US-Pon Ponca City

DOE Data Explorer

Verma, Shashi [University of Nebraska - Lincoln

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-Pon Ponca City. Site Description - The Ponca Winter Wheat site is a 65 ha rainfed wheat field in north central Oklahoma. Planting of winter wheat takes place annually in mid-fall. By late May, most of the wheat reaches maturity, allowing for mid-summer harvest.

Differences and Similarities between Summer and Winter Temperatures and Winds during MaCWAVE

NASA Technical Reports Server (NTRS)

Schmidlin, F. J.; Goldberg, R. A.

2008-01-01

The Mountain and Convective Waves Ascending Vertically Experiment (MaCWAVE) was carried out in two sequences: one during the summer from the Andoya Rocket Range (69N) during July 2002 to examine convective initiation of gravity waves. The second was a winter sequence from ESRANGE (68N) during January 2003 to examine mountain-initiated waves. Inflatable falling spheres released from small meteorological rockets provided significant information about the variation of temperature and wind from 50 km and higher. The small rocket launch activity was restricted to 12-hour periods that inhibited observing a full diurnal cycle, nonetheless, the time-history of the measurements have provided information about tidal motion. During summer, temperature variation was smaller than observed during winter when peak differences reached 15-20 K at 80-85 km. variation in zonal winds varied up to more than 100 mps in summer and winter. Times of wind vs. altitude showed that the peak zonal component occurred approximately two hours ahead of the peak meridional wind. Measurement details and the observed variations are discussed.

Differences and Similarities in MaCWAVE Summer and Winter Temperatures and Winds

NASA Technical Reports Server (NTRS)

Schmidlin, F. J.; Goldberg, R. A.

2008-01-01

Small meteorological rockets released inflatable falling spheres during the MaCWAVE Campaign. The Mountain and Convective Waves Ascending Vertically Experiment (MaCWAVE) was carried out in two parts, a summer sequence from Andoya Rocket Range (69N) during July 2002 to examine convective initiation of gravity waves and a winter sequence from ESRANGE (68N) during January 2003 to examine mountain-terrain initiated gravity waves. The sphere-tracked data provided significant information about the variation of temperature and wind from 70 km and above. The changes observed may be considered akin to tidal motion; unfortunately the launch activity was restricted to 12-hour periods, thus the observation of a full diurnal cycle was not possible. During summer, temperature variation was smaller than that observed during winter when peak to null differences reached 15-20 K at 80-85 km. Variation in the zonal winds varied up to 100+mps in summer and winter. Examination of the times of peak wind vs altitude showed that the peak zonal wind occurred approximately two hours ahead of the peak meridional wind. We provide details about the measurements and observed variations.

Supporting Habitat Management for bird conservation planning on Fort Belvoir, Virginia

Treesearch

Richard A. Fischer; Chris Eberly; Dorothy Keough

2005-01-01

The U.S. Army Corps of Engineers, Engineer Research and Development Center (ERDC), Environmental Laboratory has conducted seasonal avian surveys (winter, spring, summer, fall) from Spring 1998 through Summer 2002 at approximately 127 permanent point-count locations on Fort Belvoir, VA. This work has resulted in a data-rich baseline understanding of the distribution and...

Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants; Report 1: Baseline Studies. Volume III. The Plankton and Benthos of Lake Conway, Florida.

DTIC Science & Technology

1979-05-01

Monthly monitoring of the phytoplankton , periphyton , zooplankton, and benthic invertebrates of Lake Conway, Florida, indicates that no serious water...macrophytes. The phytoplankton community is dominated by green algae (Chlorophyta) during most of the year, with the exception of summer and early fall when...destratification and associated nutrient regeneration from the hypolimnion. Production of periphyton is highest in summer and fall and lowest in winter. Blue-greens

Monitoring of environmental conditions in taiga forests using ERS-1 SAR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rignot, E.; Way, J.B.; McDonald, K.

1994-08-01

Synthetic-aperture radar images of forest site near Manley Hot Springs (64[degree]N, 151[degree]W), Alaska, were collected between August 1991 and December 1991, day and night, every 3 days, at C-band frequency ([lambda] = 5.7 cm), vertical receive and transmit polarization, by the European Space Agency First Remote Sensing Satellite, ERS-1. During the same period, air and soil temperatures and dielectric and gravimetric moisture properties of the forest canopy and forest floor were monitored in three forest stands dominated, respectively, by black spruce (Picea mariana), white spruce (Picea glauca), and balsam poplar (Populus balsamifera). The calibrated ERS-1 radar backscatter values, [sigma][degree], ofmore » the forest stands are shown to exhibit a pronounced temporal pattern, with little separability between tree species. The largest change in [sigma][degree], a 3-dB decrease almost independent of tree species, is observed in early winter when the soil and vegetation freeze. In the summer, temporal fluctuations in [sigma][degree] are about 1--2 dB in magnitude, depending on tree species. Diurnal variations in [sigma][degree] are as large as 2 dB during fall freeze-up, and less than 1 dB in summer and winter. These temporal variations in radar backscatter from the forest are interpreted using the MIMICS radar backscatter model and the in situ surface observations as due to changes in the dielectric properties of the forest floor and forest canopy induced by precipitation (summer), drought (fall), and freezing (fall-winter) events. In winter, [sigma][degree] increases across the entire landscape, probably because of volume scattering from large depth hoar ice crystals forming in the snow pack.« less

Sulfate and nitrate collected by filter sampling near the tropopause

NASA Technical Reports Server (NTRS)

Humenik, F. M.; Lezberg, E. A.; Otterson, D. A.

1980-01-01

Filter samples collected near the tropopause with an F-106 aircraft and two Boeing 747 aircraft were analyzed for sulfate and nitrate ion content. Within the range of routine commercial flight altitudes (at or below 12.5 km), stratospheric mass mixing ratios for the winter-spring group averaged 0.26 ppbm for sulfate and 0.35 ppbm for nitrate. For the summer-fall group, stratosphere mixing ratios averaged 0.13 ppbm and 0.25 ppbm for sulfate and nitrate, respectively. Winter-spring group tropospheric mass mixing ratios averaged 0.08 ppbm for sulfate and 0.10 ppbm for nitrate, while summer-fall group tropospheric mixing ratios averaged 0.05 ppbm for sulfate and 0.08 ppbm for nitrate. Correlations of the filter data with available ozone data suggest that the sulfate and nitrate are transported from the stratosphere to the troposphere.

Total available carbohydrates in serviceberry after late dummer and fall burning

Treesearch

Benjamin Zamora; Thomas Gnojek

2001-01-01

Total available carbohydrate (TAC) storage and depletion was measured in late summer and fall burned and unburned serviceberry (Amelanchier alnifolia). The purpose of the study was to assess the influence of late season prescribed fire on the vigor of serviceberry, a key browse species on white-tailed deer (Odecoileus virginianus ochrourus) winter range in northeastern...

Summer weeds as hosts for Frankliniella occidentalis and Frankliniella fusca (Thysanoptera: Thripidae) and as reservoirs for tomato spotted wilt Tospovirus in North Carolina.

PubMed

Kahn, Noah D; Walgenbach, J F; Kennedy, G G

2005-12-01

In North Carolina, Tomato spotted wilt tospovirus (family Bunyaviridae, genus Tospovirus, TSWV) is vectored primarily by the tobacco thrips, Frankliniella fusca (Hinds), and the western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). TSWV overwinters in winter annual weeds from which it is spread to susceptible crops in spring. Because most susceptible crops are destroyed after harvest before winter weeds emerge in the fall, infected summer weeds are thought to be the principal source for spread of TSWV to winter annual weeds in fall. A survey of summer weeds associated with TSWV-susceptible crops in the coastal plain of North Carolina conducted between May and October revealed that relatively few species were commonly infected with TSWV and supported populations of F. fusca or F. occidentalis. F. occidentalis made up > 75% of vector species collected from 15 summer weed species during 2002. The number of F. occidentalis and F. fusca immatures collected from plant samples varied significantly among plant species. Ipomoea purpurea (L.) Roth, Mollugo verticillata L., Cassia obtusifolia L., and Amaranthus palmeri S. Wats supported the largest numbers of immature F. occidentalis. Richardia scabra L., M. verticillata, and Ipomoea hederacea (L.) supported the largest numbers of F. fusca immatures. TSWV was present at 16 of 17 locations, and naturally occurring infections were found in 14 of 29 weed species tested. Five of the TSWV-infected species have not previously been reported as hosts of TSWV (A. palmeri, Solidago altissima L., Ipomoea lacunosa L., I. purpurea, and Phytolacca americana L.). Estimated rates of infection were highest in I. purpurea (6.8%), M. verticillata (5.3%), and I. hederacea (1.9%). When both the incidence of infection by TSWV and the populations of F. occidentalis and F. fusca associated with each weed species are considered, the following summer weed species have the potential to act as significant sources for spread of TSWV to winter annual weeds in fall: I. purpurea, I. hederacea, M. verticillata, A. palmeri, C. obtusifolia, R. scabra, Ambrosia artemisiifolia L., Polygonum pensylvanicum L., and Chenopodium album L.

No evidence for intercohort cannibalism in mixed-size cultures of food-size and fingerling hybrid catfish (channel catfish x blue catfish) grown in ponds in winter or summer

USDA-ARS?s Scientific Manuscript database

Hybrid catfish (' Channel Catfish Ictalurus punctatus X ' Blue Catfish I. furcatus) are normally harvested by seining single-batch pond production systems in fall or winter. Ponds are typically restocked without draining. There is concern that without completely draining the pond after harvest, food...

Seasonal movements and Home-range use by female pronghorns in sagebrush-steppe communities of western South Dakota

USGS Publications Warehouse

Jacques, C.N.; Jenks, J.A.; Klaver, R.W.

2009-01-01

Knowledge of seasonal movements by pronghorns (Antilocapra americana) within the easternmost extension of sagebrush-steppe communities is limited. Current hypotheses regarding movement patterns suggest that pronghorns initiate seasonal movements in response to severe winter weather, snowfall patterns, spatial and temporal variation in forage abundance, and availability of water. From January 2002 to August 2005, we monitored movements of 76 adult (≥1.5 years) female pronghorns on 2 study areas (Harding and Fall River counties) in western South Dakota. We collected 8,750 visual locations, calculated 204 home ranges, and documented 17 seasonal movements. Eighty-four percent (n = 55) of pronghorns were nonmigratory and 10% (n = 6) were conditional migrators. Mean distance between summer and winter range was 23.1 km (SE = 2.8 km, n = 13). Five adult pronghorns (8%) dispersed a mean distance of 37.6 km (SE = 12.4 km); of which 1 female moved a straight-line distance of 75.0 km. Winter and summer home-range size varied (P < 0.0001) between study sites. Mean 95% adaptive kernel winter and summer home-range size of pronghorns was 55.5 and 19.7 km2, respectively, in Harding County and 127.2 and 65.9 km2, respectively, in Fall River County. Nonmigratory behavior exhibited by pronghorns was likely associated with minimal snow cover and moderate temperatures during winter 2002–2004. Variation in size of adult seasonal home ranges between sites was likely associated with differences in forage distribution and availability between regions.

Vacation Study Abroad, 1995/96: The Complete Guide to Summer and Short-Term Study. 45th Edition.

ERIC Educational Resources Information Center

Steen, Sara J., Ed.

This directory provides information on summer programs abroad from 1 week to several months in length and short courses of varying lengths in the fall, winter, or spring. Approximately 60 percent of the programs are sponsored by U.S. accredited colleges and universities; the others are offered by foreign universities, language schools, and other…

Summary and Evaluation of EPDA-B2 Project 70.01 at the Tennessee Appalachia Educational Cooperative July 1, 1970 through August 31, 1971.

ERIC Educational Resources Information Center

Saffels, Francis L.; Holt, William W.

Five teacher and teacher aid training program workshops held during summer and fall 1970, and winter, spring, and summer 1971 are evaluated. The subjects covered in the workshops included simulation, microteaching, role differentiation, classroom control, audiovisual instruction, learning theory, content areas, drugs, individualized instruction,…

Measurements of heavy metal concentrations from a background monitoring site in Won Ju City, Korea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Ki-Hyun; Seo, Yong-Chan; Kim, Duk-Soo

The distribution and behavior of seven heavy metal species were investigated using the data collected from a background air-quality monitoring network site established in Won Ju City, Korea. The mean and 1 SD values of seven metal species measured during the campaign periods were as follows: 1.44{+-}0.62 (Fe), 0.088{+-}0.060 (Pb), 0.004{+-}0.005 (Cd), 0.013{+-}0.021 (Cr), 0.19{+-}0.16 (Cu), 0.032{+-}0.019 (Mn), and 0.015{+-}0.013 (Ni) {mu}g/m{sup 3}. In accord with the expectation, the regression analysis of these data sets exhibited good correlations between major crustal components (e.g., Fe and Mn) but extremely poor correlations between anthropogenically derived metal species (like Ni) and other metalmore » species. Investigations of the seasonal trends of these metal species suggest the existence of several distinctive patterns among metals: (1) Pb, Fe and Ni exhibit enrichment during winter/spring relative summer/fall, (2) Cd, Cr and Cu show enrichment during fall/winter relative to spring /summer, and (3) Quite differently from the two patterns described above, Mn is enriched during spring/summer relative to fall/winter. When enrichment factors (EF) of these metals were compiled relative to Fe, it showed values on the decreasing order of: Cd (724), Pb (232), Cu (131), Ni (7.8), Cr (5.5) and Mn (1.2). Using these data, we present the fundamental pictures underlying the geochemical cycling of heavy metal constituents in the background atmosphere.« less

Strong seasonality of Bonamia sp. infection and induced Crassostrea ariakensis mortality in Bogue and Masonboro Sounds, North Carolina, USA.

PubMed

Carnegie, Ryan B; Stokes, Nancy A; Audemard, Corinne; Bishop, Melanie J; Wilbur, Ami E; Alphin, Troy D; Posey, Martin H; Peterson, Charles H; Burreson, Eugene M

2008-07-01

Asian oyster Crassostrea ariakensis is being considered for introduction to Atlantic coastal waters of the USA. Successful aquaculture of this species will depend partly on mitigating impacts by Bonamia sp., a parasite that has caused high C. ariakensis mortality south of Virginia. To better understand the biology of this parasite and identify strategies for management, we evaluated its seasonal pattern of infection in C. ariakensis at two North Carolina, USA, locations in 2005. Small (<50 mm) triploid C. ariakensis were deployed to upwellers on Bogue Sound in late spring (May), summer (July), early fall (September), late fall (November), and early winter (December) 2005; and two field sites on Masonboro Sound in September 2005. Oyster growth and mortality were evaluated biweekly at Bogue Sound, and weekly at Masonboro, with Bonamia sp. prevalence evaluated using parasite-specific PCR. We used histology to confirm infections in PCR-positive oysters. Bonamia sp. appeared in the late spring Bogue Sound deployment when temperatures approached 25 degrees C, six weeks post-deployment. Summer- and early fall-deployed oysters displayed Bonamia sp. infections after 3-4 weeks. Bonamia sp. prevalences were 75% in Bogue Sound, and 60% in Masonboro. While oyster mortality reached 100% in late spring and summer deployments, early fall deployments showed reduced (17-82%) mortality. Late fall and early winter deployments, made at temperatures <20 degrees C, developed no Bonamia sp. infections at all. Seasonal Bonamia sp. cycling, therefore, is influenced greatly by temperature. Avoiding peak seasonal Bonamia sp. activity will be essential for culturing C. ariakensis in Bonamia sp.-enzootic waters.

Foraging and metabolic consequences of semi-anadromy for an endangered estuarine fish.

PubMed

Hammock, Bruce G; Slater, Steven B; Baxter, Randall D; Fangue, Nann A; Cocherell, Dennis; Hennessy, April; Kurobe, Tomofumi; Tai, Christopher Y; Teh, Swee J

2017-01-01

Diadromy affords fish access to productive ecosystems, increasing growth and ultimately fitness, but it is unclear whether these advantages persist for species migrating within highly altered habitat. Here, we compared the foraging success of wild Delta Smelt-an endangered, zooplanktivorous, annual, semi-anadromous fish that is endemic to the highly altered San Francisco Estuary (SFE)-collected from freshwater (<0.55 psu) and brackish habitat (≥0.55 psu). Stomach fullness, averaged across three generations of wild Delta Smelt sampled from juvenile through adult life stages (n = 1,318), was 1.5-fold higher in brackish than in freshwater habitat. However, salinity and season interacted, with higher fullness (1.7-fold) in freshwater than in brackish habitat in summer, but far higher fullness in brackish than freshwater habitat during fall/winter and winter/spring (1.8 and 2.0-fold, respectively). To examine potential causes of this interaction we compared mesozooplankton abundance, collected concurrently with the Delta Smelt, in freshwater and brackish habitat during summer and fall/winter, and the metabolic rate of sub-adult Delta Smelt acclimated to salinities of 0.4, 2.0, and 12.0 psu in a laboratory experiment. A seasonal peak in mesozooplankton density coincided with the summer peak in Delta Smelt foraging success in freshwater, and a pronounced decline in freshwater mesozooplankton abundance in the fall coincided with declining stomach fullness, which persisted for the remainder of the year (fall, winter and spring). In brackish habitat, greater foraging 'efficiency' (prey items in stomachs/mesozooplankton abundance) led to more prey items per fish and generally higher stomach fullness (i.e., a higher proportion of mesozooplankton detected in concurrent trawls were eaten by fish in brackish habitat). Delta Smelt exhibited no difference in metabolic rate across the three salinities, indicating that metabolic responses to salinity are unlikely to have caused the stomach fullness results. Adult migration and freshwater spawning therefore places young fish in a position to exploit higher densities of prey in freshwater in the late spring/summer, and subsequent movement downstream provides older fish more accessible prey in brackish habitat. Thus, despite endemism to a highly-altered estuary, semi-anadromy provided substantial foraging benefits to Delta Smelt, consistent with other temperate migratory fish.

Foraging and metabolic consequences of semi-anadromy for an endangered estuarine fish

PubMed Central

Slater, Steven B.; Baxter, Randall D.; Fangue, Nann A.; Cocherell, Dennis; Hennessy, April; Kurobe, Tomofumi; Tai, Christopher Y.; Teh, Swee J.

2017-01-01

Diadromy affords fish access to productive ecosystems, increasing growth and ultimately fitness, but it is unclear whether these advantages persist for species migrating within highly altered habitat. Here, we compared the foraging success of wild Delta Smelt—an endangered, zooplanktivorous, annual, semi-anadromous fish that is endemic to the highly altered San Francisco Estuary (SFE)—collected from freshwater (<0.55 psu) and brackish habitat (≥0.55 psu). Stomach fullness, averaged across three generations of wild Delta Smelt sampled from juvenile through adult life stages (n = 1,318), was 1.5-fold higher in brackish than in freshwater habitat. However, salinity and season interacted, with higher fullness (1.7-fold) in freshwater than in brackish habitat in summer, but far higher fullness in brackish than freshwater habitat during fall/winter and winter/spring (1.8 and 2.0-fold, respectively). To examine potential causes of this interaction we compared mesozooplankton abundance, collected concurrently with the Delta Smelt, in freshwater and brackish habitat during summer and fall/winter, and the metabolic rate of sub-adult Delta Smelt acclimated to salinities of 0.4, 2.0, and 12.0 psu in a laboratory experiment. A seasonal peak in mesozooplankton density coincided with the summer peak in Delta Smelt foraging success in freshwater, and a pronounced decline in freshwater mesozooplankton abundance in the fall coincided with declining stomach fullness, which persisted for the remainder of the year (fall, winter and spring). In brackish habitat, greater foraging ‘efficiency’ (prey items in stomachs/mesozooplankton abundance) led to more prey items per fish and generally higher stomach fullness (i.e., a higher proportion of mesozooplankton detected in concurrent trawls were eaten by fish in brackish habitat). Delta Smelt exhibited no difference in metabolic rate across the three salinities, indicating that metabolic responses to salinity are unlikely to have caused the stomach fullness results. Adult migration and freshwater spawning therefore places young fish in a position to exploit higher densities of prey in freshwater in the late spring/summer, and subsequent movement downstream provides older fish more accessible prey in brackish habitat. Thus, despite endemism to a highly-altered estuary, semi-anadromy provided substantial foraging benefits to Delta Smelt, consistent with other temperate migratory fish. PMID:28291808

The Ram's Horn.

ERIC Educational Resources Information Center

Rassias, John A., Ed.; And Others

1983-01-01

The summer-fall and winter-spring numbers of the journal, "The Ram's Horn," contain these articles: "The Text as Dramatic Departure"; "The Dartmouth Language Outreach Approach to Spanish for Police Action"; "The Dartmouth Intensive Language Model (DILM) in Florida: John Rassias with High School Teachers";…

Mesospheric momentum fluxes observed by the MST radar at Poker Flat, Alaska

NASA Technical Reports Server (NTRS)

Wang, Ding-Yi; Fritts, David C.

1990-01-01

An analysis of the wave motions observed with the Poker Flat MST radar during the winter, summer, and fall of 1986 is presented. Monthly and daily mean winds, momentum fluxes, and velocity variances are investigated in detail. While several features are in agreement with previous measurements, some significant differences also are found to exist in the observations. Monthly mean horizontal winds between 82 and 89 km have amplitudes of 20-40 m/s westward and 10-25 m/s southward in July and August. In fall and winter, the horizontal winds between 58 and 75 km are weaker and essentially eastward.

Wintering bird response to fall mowing of herbaceous buffers

USGS Publications Warehouse

Blank, P.J.; Parks, J.R.; Dively, G.P.

2011-01-01

Herbaceous buffers are strips of herbaceous vegetation planted between working agricultural land and streams or wetlands. Mowing is a common maintenance practice to control woody plants and noxious weeds in herbaceous buffers. Buffers enrolled in Maryland's Conservation Reserve Enhancement Program (CREP) cannot be mowed during the primary bird nesting season between 15 April and 15 August. Most mowing of buffers in Maryland occurs in late summer or fall, leaving the vegetation short until the following spring. We studied the response of wintering birds to fall mowing of buffers. We mowed one section to 10-15 cm in 13 buffers and kept another section unmowed. Ninety-two percent of birds detected in buffers were grassland or scrub-shrub species, and 98% of all birds detected were in unmowed buffers. Total bird abundance, species richness, and total avian conservation value were significantly greater in unmowed buffers, and Savannah Sparrows (Passerculus sandwichensis), Song Sparrows (Melospiza melodia), and White-throated Sparrows (Zonotrichia albicollis) were significantly more abundant in unmowed buffers. Wintering bird use of mowed buffers was less than in unmowed buffers. Leaving herbaceous buffers unmowed through winter will likely provide better habitat for wintering birds. ?? 2011 by the Wilson Ornithological Society.

Patterns of Diel Variation in Nitrate Concentrations in the Potomac River

NASA Astrophysics Data System (ADS)

Burns, D. A.; Miller, M. P.; Pellerin, B. A.; Capel, P. D.

2015-12-01

The Potomac River is the second largest source of nitrogen to Chesapeake Bay, where reducing nutrient loads has been a focus of efforts to improve estuarine trophic status. Two years of high frequency sensor measurements of nitrate (NO3-) concentrations in the Upper Potomac River at the Little Falls gage were analyzed to quantify seasonal variation in the magnitude and timing of the apparent loss of NO3- from the water column that results from diel-driven processes. In addition to broad seasonal and flow-driven variation in NO3- concentrations, clear diel patterns were evident in the river, especially during low flow conditions that follow stormflow by several days. Diel variation was about 0.01 mg N/L in winter and 0.02 to 0.03 mg N/L in summer with intermediate values during spring and fall. This variation was equivalent to <1% of the mean daily NO3- concentration in winter and about 4% in summer; however, variation >10% occurred during some summer days. Maximum diel concentrations occurred during mid- to late-morning in most seasons, with the most repeatable patterns in summer and wider variation in timing during fall and winter. Diel NO3- loss diminished loads by about 0.6% in winter and 1.3% in summer, and diel-driven processes were minor compared to estimates of total in-stream NO3- loss that averaged about one-third of the inferred groundwater NO3- contribution to the river network. The magnitude of diel NO3- variation was more strongly related to metrics based on water temperature and discharge than to metrics based on photosynthetically active radiation. Despite the fairly low diminishment of NO3- loads attributable to diel variation, estimates of diel NO3- uptake were fairly high compared to published values from smaller streams and rivers. The diel NO3- patterns observed in the Potomac River are consistent with photosynthesis of periphyton as a principal driver which may be linked to denitrification through the release of labile carbon. The extent to which these diel patterns are related to measures of aquatic metabolism are unknown as is the role of dispersion in obscuring diel patterns. Improvements to these diel estimates will require additional measures such as dissolved oxygen and ammonium, and the use of a second upstream measurement station to better constrain NO3- uptake values.

Environmental Factors Affecting Mercury in Camp Far West Reservoir, California, 2001-03

USGS Publications Warehouse

Alpers, Charles N.; Stewart, A. Robin; Saiki, Michael K.; Marvin-DiPasquale, Mark C.; Topping, Brent R.; Rider, Kelly M.; Gallanthine, Steven K.; Kester, Cynthia A.; Rye, Robert O.; Antweiler, Ronald C.; De Wild, John F.

2008-01-01

This report documents water quality in Camp Far West Reservoir from October 2001 through August 2003. The reservoir, located at approximately 300 feet above sea level in the foothills of the northwestern Sierra Nevada, California, is a monomictic lake characterized by extreme drawdown in the late summer and fall. Thermal stratification in summer and fall is coupled with anoxic conditions in the hypolimnion. Water-quality sampling was done at approximately 3-month intervals on eight occasions at several stations in the reservoir, including a group of three stations along a flow path in the reservoir: an upstream station in the Bear River arm (principal tributary), a mid-reservoir station in the thalweg (prereservoir river channel), and a station in the deepest part of the reservoir, in the thalweg near Camp Far West Dam. Stations in other tributary arms of the reservoir included those in the Rock Creek arm of the reservoir, a relatively low-flow tributary, and the Dairy Farm arm, a small tributary that receives acidic, metal-rich drainage seasonally from the inactive Dairy Farm Mine, which produced copper, zinc, and gold from underground workings and a surface pit. Several water-quality constituents varied significantly by season at all sampling stations, including major cations and anions, total mercury (filtered and unfiltered samples), nitrogen (ammonia plus organic), and total phosphorus. A strong seasonal signal also was observed for the sulfurisotope composition of aqueous sulfate from filtered water. Although there were some spatial differences in water quality, the seasonal variations were more profound. Concentrations of total mercury (filtered and unfiltered water) were highest during fall and winter; these concentrations decreased at most stations during spring and summer. Anoxic conditions developed in deep parts of the reservoir during summer and fall in association with thermal stratification. The highest concentrations of methylmercury in unfiltered water were observed in samples collected during summer from deepwater stations in the anoxic hypolimnion. In the shallow (less than 14 meters depth) oxic epilimnion, concentrations of methylmercury in unfiltered water were highest during the spring and lowest during the fall. The ratio of methylmercury to total mercury (MeHg/HgT) increased systematically from winter to spring to summer, largely in response to the progressive seasonal decrease in total mercury concentrations, but also to some extent because of increases in MeHg concentrations during summer. Water-quality data for Camp Far West Reservoir are used in conjunction with data from linked studies of sediment and biota to develop and refine a conceptual model for mercury methylation and bioaccumulation in the reservoir and the lower Bear River watershed. It is hypothesized that MeHg is produced by sulfate-reducing bacteria in the anoxic parts of the water column and in shallow bed sediment. Conditions were optimal for this process during late summer and fall. Previous work has indicated that Camp Far West Reservoir is a phosphate-limited system - molar ratios of inorganic nitrogen to inorganic phosphorus in filtered water were consistently greater than 16 (the Redfield ratio), sometimes by orders of magnitude. Therefore, concentrations of orthophosphate were expectedly very low or below detection at all stations during all seasons. It is further hypothesized that iron-reducing bacteria facilitate release of phosphorus from iron-rich sediments during summer and early fall, stimulating phytoplankton growth in the fall and winter, and that the MeHg produced in the hypolimnion and metalimnion is released to the entire water column in the late fall during reservoir destratification (vertical mixing). Mercury bioaccumulation factors (BAF) were computed using data from linked studies of biota spanning a range of trophic position: zooplankton, midge larvae, mayfly nymphs, crayfish, threadfin shad, bluegill,

Lighting Condition Analysis for Mars' Moon Phobos

NASA Technical Reports Server (NTRS)

Li, Zu Qun; de Carufel, Guy; Crues, Edwin Z.; Bielski, Paul

2016-01-01

This study used high fidelity computer simulation to investigate the lighting conditions, specifically the solar radiation flux over the surface, on Phobos. Ephemeris data from the Jet Propulsion Laboratory (JPL) DE405 model was used to model the state of the Sun, Earth, Moon, and Mars. An occultation model was developed to simulate Phobos' self-shadowing and its solar eclipses by Mars. The propagated Phobos state was compared with data from JPL's Horizon system to ensure the accuracy of the result. Results for Phobos lighting conditions over one Martian year are presented, which include the duration of solar eclipses, average solar radiation intensity, surface exposure time, available energy per unit area for sun tracking arrays, and available energy per unit area for fixed arrays (constrained by incident angle). The results show that: Phobos' solar eclipse time varies throughout the Martian year, with longer eclipse durations during the Martian spring and fall seasons and no eclipses during the Martian summer and winter seasons; solar radiation intensity is close to minimum at the summer solstice and close to maximum at the winter solstice; exposure time per orbit is relatively constant over the surface during the spring and fall but varies with latitude during the summer and winter; and Sun tracking solar arrays generate more energy than a fixed solar array. A usage example of the result is also present in this paper to demonstrate the utility.

Antarctic Sea ice variations and seasonal air temperature relationships

NASA Technical Reports Server (NTRS)

Weatherly, John W.; Walsh, John E.; Zwally, H. J.

1991-01-01

Data through 1987 are used to determine the regional and seasonal dependencies of recent trends of Antarctic temperature and sea ice. Lead-lag relationships involving regional sea ice and air temperature are systematically evaluated, with an eye toward the ice-temperature feedbacks that may influence climatic change. Over the 1958-1087 period the temperature trends are positive in all seasons. For the 15 years (l973-l987) for which ice data are available, the trends are predominantly positive only in winter and summer, and are most strongly positive over the Antarctic Peninsula. The spatially aggregated trend of temperature for this latter period is small but positive, while the corresponding trend of ice coverage is small but negative. Lag correlations between seasonal anomalies of the two variables are generally stronger with ice lagging the summer temperatures and with ice leading the winter temperatures. The implication is that summer temperatures predispose the near-surface waters to above-or below-normal ice coverage in the following fall and winter.

Estimation of net accumulation rate at a Patagonian glacier by ice core analyses using snow algae

NASA Astrophysics Data System (ADS)

Kohshima, Shiro; Takeuchi, Nozomu; Uetake, Jun; Shiraiwa, Takayuki; Uemura, Ryu; Yoshida, Naohiro; Matoba, Sumito; Godoi, Maria Angelica

2007-10-01

Snow algae in a 45.97-m-long ice core from the Tyndall Glacier (50°59'05″S, 73°31'12″W, 1756 m a.s.l.) in the Southern Patagonian Icefield were examined for potential use in ice core dating and estimation of the net accumulation rate. The core was subjected to visual stratigraphic observation and bulk density measurements in the field, and later to analyses of snow algal biomass, water isotopes ( 18O, D), and major dissolved ions. The ice core contained many algal cells that belonged to two species of snow algae growing in the snow near the surface: Chloromonas sp. and an unknown green algal species. Algal biomass and major dissolved ions (Na +, K +, Mg 2+, Ca 2+, Cl -, SO 42-) exhibited rapid decreases in the upper 3 m, probably owing to melt water elution and/or decomposition of algal cells. However, seasonal cycles were still found for the snow algal biomass, 18O, D-excess, and major ions, although the amplitudes of the cycles decreased with depth. Supposing that the layers with almost no snow algae were the winter layers without the melt water essential to algal growth, we estimated that the net accumulation rate at this location was 12.9 m a - 1 from winter 1998 to winter 1999, and 5.1 m from the beginning of winter to December 1999. These estimates are similar to the values estimated from the peaks of 18O (17.8 m a - 1 from summer 1998 to summer 1999 and 11.0 m from summer to December 1999) and those of D-excess (14.7 m a - 1 from fall 1998 to fall 1999 and 8.6 m a - 1 from fall to December 1999). These values are much higher than those obtained by past ice core studies in Patagonia, but are of the same order of magnitude as those predicted from various observations at ablation areas of Patagonian glaciers.

BIOGENIC SOURCES OF FORMALDEHYDE AND ACETALDEHYDE DURING SUMMER AND WINTER CONDITIONS

EPA Science Inventory

Photochemical modeling estimated contributions to ambient concentrations of formaldehyde and acetaldehyde from biogenic emissions over the continental United States during January 2001 (Eos Trans. AGU, 83(47), Fall Meet. Suppl., Abstract A52B-0117). Results showed that maximum co...

Transportation of market-weight pigs: II. effect of season and location within truck on behavior with an eight-hour transport.

PubMed

Torrey, S; Bergeron, R; Faucitano, L; Widowski, T; Lewis, N; Crowe, T; Correa, J A; Brown, J; Hayne, S; Gonyou, H W

2013-06-01

Transportation of pigs to slaughter has the potential to negatively impact animal welfare, particularly in hot temperatures and over long transport durations. The objective of this experiment was to determine if season and location within vehicle influenced the behavior of market-weight pigs during loading, transit, unloading, and lairage after a long-distance trip to slaughter. On a pot-belly truck, 1,170 pigs were transported (n = 195 pigs/wk in 7 experimental compartments) for 8 h to a commercial abattoir in summer (6 wk) and winter (5 wk). Pig behavior was observed at loading, in transit, at unloading, and in lairage. Handler intervention at loading was observed, and the time to load and unload was recorded. Although season did not (P = 0.91) affect loading time, more prods (P = 0.014) were necessary to load pigs in summer than winter. Loading in winter also tended to be longer (P = 0.071) into compartments involving internal ramps. In transit, more pigs (P = 0.025) were standing in winter compared with summer. Unloading took longer (P < 0.006) in winter than in summer and from compartments where pigs had to negotiate ramps and 180° turns. Furthermore, pigs in summer experienced more slipping (P = 0.032), falling (P = 0.004), overlapping (P < 0.001), and walking backward (P < 0.001) than pigs in winter. Pigs unloading from compartments with internal ramps slipped more (P < 0.0001) than other pigs. Season influenced latency to rest in lairage, with those transported in summer resting sooner (P < 0.0001) than those in winter. In conclusion, season and location within trucks differentially affect pig behavior before, during, and after long-distance transportation. Differences in lighting and temperature between seasons and the inclusion of internal ramps within vehicles may play important roles in the welfare of pigs transported to slaughter.

Trans-boundary movement of mercury in the Northeast Asian region predicted by CAMQ-Hg from anthropogenic emissions distribution

NASA Astrophysics Data System (ADS)

Sung, Jin-Ho; Roy, Debananda; Oh, Joo-Sung; Back, Seung-Ki; Jang, Ha-Na; Kim, Seong-Heon; Seo, Yong-Chil; Kim, Jeong-Hun; Lee, Chong Bum; Han, Young-Ji

2018-05-01

The percentage contribution of trans-boundary mercury (Hg) from China at different locations in South Korea was estimated from Hg anthropogenic emission distributions using the Hg dispersion model, CMAQ-Hg. This investigation quantifies the trans-boundary Hg emissions as contribution ratios. In addition, the long-range transportation frequency is also calculated, to verify inflow cases from China. The seasonal distribution of the Hg contribution ratio was found to be highest in winter (40%), followed by fall (16%). Seasonal observations of Hg inflow frequencies were estimated as 40%, 25%, 21%, and 4% in winter, fall, summer, and spring, respectively, at the same location. Such results would be produced by the wind generally blowing from the west and north-west with a speed of 5.0 m/s and 4.5 m/s, respectively, during winter and fall, around the study area. This study made an effort to quantify the trans-boundary Hg transport and to plot Hg anthropogenic emissions distribution in the region.

Waterbird habitat in California's Central Valley basins under climate, urbanization, and water management scenarios

USGS Publications Warehouse

Matchett, Elliott L.; Fleskes, Joseph

2018-01-01

California's Central Valley provides critical, but threatened habitat and food resources for migrating and wintering waterfowl, shorebirds, and other waterbirds. The Central Valley is comprised of nine basins that were defined by the Central Valley Joint Venture (CVJV) to assist in conservation planning. Basins vary in composition and extent of habitats, which primarily include croplands and wetlands that rely on water supplies shared with other competing human and environmental uses. Changes in climate, urban development, and water supply management are uncertain and could reduce future availability of water supplies supporting waterbird habitats and limit effectiveness of wetland restoration planned by the CVJV to support wintering waterbirds. We modeled 17 plausible scenarios including combinations of three climate projections, three urbanization rates, and five water supply management options to promote agricultural and urban water uses, with and without wetland restoration. Our research examines the reduction in quantity and quality of habitats during the fall migration-wintering period by basin under each scenario, and the efficacy of planned wetland restoration to compensate reductions in flooded areas of wetland habitats. Scenario combinations of projected climate, urbanization, and water supply management options reduced availability of flooded cropland and wetland habitats during fall-winter and degraded the quality of seasonal wetlands (i.e., summer-irrigation for improved forage production), though the extent and frequency of impacts varied by basin. Planned wetland restoration may substantially compensate for scenario-related effects on wetland habitats in each basin. However, results indicate that Colusa, Butte, Sutter, San Joaquin, and Tulare Basins may require additional conservation to support summer-irrigation of seasonal wetlands and winter-flooding of cropland habitats. Still further conservation may be required to provide sufficient areas of flooded seasonal and semi-permanent wetlands in San Joaquin and Tulare Basins during fall-winter. The main objective of this research is to provide decision-support for achieving waterbird conservation goals in the valley and to inform CVJV's regional conservation planning.

Seasonal variation of the global mixed layer depth: comparison between Argo data and FIO-ESM

NASA Astrophysics Data System (ADS)

Zhang, Yutong; Xu, Haiming; Qiao, Fangli; Dong, Changming

2018-03-01

The present study evaluates a simulation of the global ocean mixed layer depth (MLD) using the First Institute of Oceanography-Earth System Model (FIOESM). The seasonal variation of the global MLD from the FIO-ESM simulation is compared to Argo observational data. The Argo data show that the global ocean MLD has a strong seasonal variation with a deep MLD in winter and a shallow MLD in summer, while the spring and fall seasons act as transitional periods. Overall, the FIO-ESM simulation accurately captures the seasonal variation in MLD in most areas. It exhibits a better performance during summer and fall than during winter and spring. The simulated MLD in the Southern Hemisphere is much closer to observations than that in the Northern Hemisphere. In general, the simulated MLD over the South Atlantic Ocean matches the observation best among the six areas. Additionally, the model slightly underestimates the MLD in parts of the North Atlantic Ocean, and slightly overestimates the MLD over the other ocean basins.

Altered soluble epoxide hydrolase-derived oxylipins in patients with seasonal major depression: An exploratory study.

PubMed

Hennebelle, Marie; Otoki, Yurika; Yang, Jun; Hammock, Bruce D; Levitt, Anthony J; Taha, Ameer Y; Swardfager, Walter

2017-06-01

Many cytochrome p450-derived lipids promote resolution of inflammation, in contrast to their soluble epoxide hydrolase(sEH)-derived oxylipin breakdown products. Here we compare plasma oxylipins and precursor fatty acids between seasons in participants with major depressive disorder with seasonal pattern (MDD-s). Euthymic participants with a history of MDD-s recruited in summer-fall were followed-up in winter. At both visits, a structured clinical interview (DSM-5 criteria) and the Beck Depression Inventory II (BDI-II) were administered. Unesterified and total oxylipin pools were assayed by liquid chromatography tandem mass-spectrometry (LC-MS/MS). Precursor fatty acids were measured by gas chromatography. In nine unmedicated participants euthymic at baseline who met depression criteria in winter, BDI-II scores increased from 4.9±4.4 to 19.9±7.7. Four sEH-derived oxylipins increased in winter compared to summer-fall with moderate to large effect sizes. An auto-oxidation product (unesterified epoxyketooctadecadienoic acid) and lipoxygenase-derived 13-hydroxyoctadecadienoic acid also increased in winter. The cytochrome p450-derived 20-COOH-leukotriene B4 (unesterified) and total 14(15)-epoxyeicosatetraenoic acid, and the sEH-derived 14,15-dihydroxyeicostrienoic acid (unesterified), decreased in winter. We conclude that winter depression was associated with changes in cytochrome p450- and sEH-derived oxylipins, suggesting that seasonal shifts in omega-6 and omega-3 fatty acid metabolism mediated by sEH may underlie inflammatory states in symptomatic MDD-s. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 juvenilemore » 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 overwinter survival in the downstream areas. Fish from Catherine Creek showed no difference in detection rates between the fall and winter tag groups, indicating similar overwinter survival in the upper and lower rearing areas. Chinook salmon parr were generally associated with low velocity habitat types during winter in Catherine Creek, and both winter and summer in the Lostine River. In summer 1997, we PIT-tagged parr on Catherine Creek and the Minam and Imnaha rivers in order to monitor their subsequent migration as smolts through the Snake and Columbia River hydrosystem. We found significant differences among populations in smolt migration timing at Lower Granite Dam in 1998. Fish from Catherine Creek and the Minam and Imnaha rivers were detected in the hydrosystem at rates of 16.4, 20.5, and 28.1%, respectively. In 1998, we estimated parr abundance and the number of parr produced per redd in Catherine Creek and the Lostine River. We estimated that 429 mature, age 1+ male parr and 13,222 immature, age 0+ parr were present in Catherine Creek in August. An average of 29 mature, age 1+ male parr and 287 immature, age 0+ parr were produced from each redd constructed in 1996 and 1997, respectively. We estimated that 75 mature, age 1+ male parr and 40,748 immature, age 0+ parr were present in the Lostine River in August. An average of 3 mature, age 1+ male parr and 832 immature, age 0+ parr were produced from each redd constructed in 1996 and 1997, respectively. For every anadromous female spawner in Catherine Creek and the Lostine River in 1998, there were an estimated 13 and 3 mature male parr, respectively.« less

Microhabitat parameters and life-history characteristics of fallicambarus gordonz fitzpatrick, a crayfish associated with pitcher-plant bogs in southern Mississippi

Treesearch

Carol E. Johnston; Chester Figiel

1997-01-01

Fallicambarus gordoni, a crayfish found only in pitcher-plant bogs, is restricted to the DeSoto National Forest, Perry County, Mississippi, U.S.A. The species is active from late fall through late spring, and apparentiy estivates during the summer when bogs are dry. Ovigerous females were found in late fall and winter, and small juveniles were collected in February....

Development of truck axle spectra from Oregon weigh-in-motion data for use in pavement design and analysis.

DOT National Transportation Integrated Search

2008-01-01

(ADTT) volumes, were selected to characterize axle weight and spacing spectra on Oregon state highways. : Seasonal variations were considered by investigating data occurring over the four seasons: winter, spring, summer, : and fall. WIM data were cle...

Fall and winter foods of northern pintails in the Sacramento Valley, California

USGS Publications Warehouse

Miller, Michael R.

1987-01-01

Food habits of northern pintails (Anas acuta) were investigated on 3 national wildlife refuges in the western portion of the Sacramento Valley, California, from August to March 1979-82. Pintails consumed 97% (aggregate % dry wt) plant food during diurnal foraging on national wildlife refuge rice, summer-irrigated, and summer-dry habitats from August through January. Invertebrate use increased to 28.9-65.6% of the diet in these habitats during February and March. Rice, swamp timothy (Heleochloa schoenoides), flatsedges (Cyperus spp.), common barnyardgrass (Echinochloa crusgalli), southern naiad (Najas guadalupensis), and smartweed (Polygonum spp.) seeds, miscellaneous vegetation, snails (Gastropoda), and midge (Diptera) and water beetle (Coleoptera) larvae were most important. These foods usually were taken proportional to or greater than availability. Rice was the most important food of pintails feeding nocturnally off the refuges in harvested rice fields from October through January (99.7%) and February and March (63%; barnyardgrass formed 31% of the diet). In August and October, some pintails consumed invertebrates or bulrush (Scirpus spp. ) seedlings in marshes soon after feeding in refuge rice (Aug) or harvested commercial rice fields (Oct), thereby increasing dietary protein. In late winter, females and males obtained similar (P > 0.05) percentages of invertebrates from refuge habitats. Important dietary seeds and invertebrates contained high protein or metabolizable energy content. Management should maintain adequate seed production in fall and mid-winter and invertebrate biomass in late winter.

Gross primary production controls the subsequent winter CO2 exchange in a boreal peatland.

PubMed

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.

Effect of Hartha and Najibia power plants on water quality indices of Shatt Al-Arab River, south of Iraq

NASA Astrophysics Data System (ADS)

Al-Aboodi, Ali H.; Abbas, Sarmad A.; Ibrahim, Husham T.

2018-05-01

The main object of this research is to assess the water quality of Shatt Al-Arab River and its suitability for various purposes near power plants (Hartha and Najibia) through physical and chemical analysis [temperature, pH, EC, Cl-, Na+, K+, Ca+2, Mg+2, HCO3 -, NO3 -, SO 4 -2 , Fe+, total alkalinity, total hardness, biological oxygen demand (BOD5), NH4 +, and NO2 -] using water quality index (WQI), organic pollution index (OPI), sodium adsorption ratio (SAR), and percentage of sodium ion (Na%) during the dry season (August, 2016) and the wet season (January, 2017). WQI of Shatt Al-Arab falls under very poor quality during summer season, while it ranges from very poor quality to unsuitable for drinking purposes during winter season. There is a clear effect of power plants on water quality. Hartha and Najibia power plants contribute to the deterioration of water quality by increasing the percentage ratio of WQI near these plants by 13.22 and 9.69%, respectively, compared to the north sites of these plants during summer season. The percentage ratios of increased WQI near Hartha and Najibia power plants compared to the north sites of these plants are 17.93 and 15.92%, respectively, during winter season. Water quality of Shatt Al-Arab falls under a high level of organic pollution during the summer and winter seasons. There is a slight effect by the power plants on the OPI. Hartha and Najibia power plants contributed to the change of the OPI by 10% compared to the north site of Hartha power plant. According to the comparison between the SAR values which represent the suitability of water for serve irrigation purposes and SAR values of Shatt Al-Arab, all sites lie in the first class (excellent). According to Na+%, the type of surface water in the studied area lies in good class during winter season and permissible class during summer season.

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

PubMed

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.

Long-term observations of saccharides in remote marine aerosols from the western North Pacific: A comparison between 1990-1993 and 2006-2009 periods

NASA Astrophysics Data System (ADS)

Chen, Jing; Kawamura, Kimitaka; Liu, Cong-Qiang; Fu, Pingqing

2013-03-01

Anhydrosugars (galactosan, mannosan and levoglucosan), sugars (xylose, fructose, glucose, sucrose and trehalose) and sugar alcohols (erythritol, arabitol, mannitol and inositol) were measured in the aerosol samples collected in a remote island (Chichi-Jima, Japan) in the western North Pacific from 1990 to 1993 and from 2006 to 2009. Total concentrations of anhydrosugars, the biomass burning tracers, were 0.01-5.57 ng m-3 (average 0.76 ng m-3) during 1990-1993 versus 0.01-7.19 ng m-3 (0.64 ng m-3) during 2006-2009. Their seasonal variations were characterized by winter/spring maxima and summer/fall minima. Such a seasonal pattern should be caused by the enhanced long-range atmospheric transport of biomass burning products and terrestrial organic matter (such as higher plant detritus and soil dust) from the Asian continent in winter/spring seasons, when the westerly or winter monsoon system prevails over the western North Pacific. Sugars and sugar alcohols showed different seasonal patterns. The monthly mean concentrations of erythritol, arabitol, mannitol, inositol, fructose, glucose and trehalose were found to be higher in spring/summer and lower in fall/winter during both 1990-1993 and 2006-2009 periods, indicating an enhanced biogenic emission of aerosols in warm seasons. Interestingly, saccharides showed a gradual decrease in their concentrations from 1991 to 1993 and an increase from 2006 to 2009. In addition, the monthly averaged concentrations of sugars and sugar alcohols showed maxima in early summer during 1990-1993, which occurred about 1-2 months earlier than those during 2006-2009. Such a clear seasonal shift may be attributable to the changes in the strength of westerly and trade wind systems during two periods.

Palynological analysis of camelid coprolites: seasonality in the use of the site Cerro Casa de Piedra 7 (Santa Cruz, Argentina)

NASA Astrophysics Data System (ADS)

Velázquez, Nadia Jimena; Burry, Lidia Susana; Fugassa, Martín Horacio; Civalero, María Teresa; Aschero, Carlos Alberto

2014-01-01

Palynological, palaeoparasitological and paleobotanical studies of coprolites found in archaeological sites from Perito Moreno National Park (47°57‧S72°05‧W) yielded information on diet, palaeoenvironment and health. These studies allowed adding evidence to the reconstruction of life history of the hunter-gatherers that inhabited Patagonia during the Holocene. We examined the season of the year when camelid Lama guanicoe coprolites (5400 ± 64 yr 14C BP to 9640 ± 190 yr 14C BP) were deposited at Cerro Casa de Piedra 7 (site CCP7). The study used palynological evidence and comparison with pollen spectra of modern feces collected during summer, fall, winter and spring of 2010. The dominant types were: pollen of Nothofagus, Empetrum rubrum, Asteraceae subfam. Asteroideae, Nassauvia, Caryophyllaceae and Poaceae; fern spores; remains of Eimeria macusaniensis; and plant remains of Poaceae, Festuca pallescens, Stipa speciosa, Armeria maritima, Gaultheria mucronata and E. rubrum. Pollen spectra of modern and fossil feces were used for multivariate analysis. Coprolites associated to fall and winter modern feces. These results and those obtained from pollen concentration values and the presence of pollen types indicators of seasonality, allowed the determination of summer, fall and winter coprolites. However, caution must be taken with the seasonality results of coprolites dated earlier than 9000 years BP since the environmental conditions differed from now. The site was probably a camelid shelter during the unfavorable seasons.

Seasonality of striatal dopamine synthesis capacity in Parkinson's disease.

PubMed

Kaasinen, Valtteri; Jokinen, Pekka; Joutsa, Juho; Eskola, Olli; Rinne, Juha O

2012-11-14

Recent neuroimaging evidence suggests that the healthy human brain dopaminergic system may show seasonal rhythmicity, as striatal dopamine synthesis capacity has been reported to be higher during fall and winter. There is additional evidence about season of birth effects on morbidity in several neuropsychiatric disorders. We investigated possible seasonal changes in dopamine synthesis capacity in a relatively large sample of Parkinson's disease patients. 6-[(18)F]fluoro-l-DOPA brain PET scans for 109 Parkinson's disease patients were performed during different seasons and the effects of season of scanning and season of birth on striatal tracer uptake were studied, controlling for covariates such as age, sex and disease severity. The patients scanned during fall and winter had 15% higher tracer uptake in the right putamen compared to patients scanned during spring and summer (p=0.04). Patients born during winter and spring had 10% higher dopamine synthesis capacity in the left caudate (p=0.008), 8% higher capacity in the right caudate (p=0.04) and 16% higher capacity in the putamen contralateral to the side of predominant motor symptoms (p=0.02) compared to patients born during summer and fall (after correcting for differences in age, sex, disease severity, scanner and season of scanning). The results suggest that there are seasonal oscillations also in the hypoactive dopaminergic system of Parkinson's disease patients. Findings concerning season of birth further suggest that there may be gestational or perinatal seasonal factors, which influence dopaminergic function in adulthood. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Survival of adult martens in Northern Wisconsin

Treesearch

Nicholas P. McCann; Patrick A. Zollner; Jonathan H. Gilbert

2010-01-01

Low adult marten (Martes americana) survival may be one factor limiting their population growth >30 yr after their reintroduction in Wisconsin, USA. We estimated annual adult marten survival at 0.81 in northern Wisconsin, with lower survival during winter (0.87) than summer-fall (1.00). Fisher (Martes pennanti) and raptor kills...

Seasonal habitat requirements for sage-grouse: spring, summer, fall, and winter

Treesearch

Clait E. Braun; John W. Connelly; Michael A. Schroeder

2005-01-01

Sage-grouse (Centrocercus minimus, C. urophasianus) are dependent upon live sagebrush (Artemisia spp.) for all life processes across their entire range. This paper describes habitats used by sage-grouse as documented in the scientific literature. The leaves of sagebrush are eaten by sage-grouse throughout the...

Record of El Niño in planktonic foraminiferal assemblages from the Gulf of Tehuantepec, Mexico (Eastern Tropical Pacific)

NASA Astrophysics Data System (ADS)

Machain-Castillo, M. L.; Nava-Fernandez, X. A.; Thunell, R.; Tappa, E.

2013-05-01

The planktonic foraminiferal assemblages from two sediment traps deployed in the Gulf of Tehuantepec, Mexico (Eastern Tropical Pacific) during a five year period (2006 to 2010) were recorded. The species abundance data were subjected to a Q-mode factor analysis that depicts alternating associations of planktonic foraminifera, generally related to seasonally varying oceanographic conditions. During winter-spring season, the oceanography of the Gulf of Tehuantepec is driven by strong northern winds that cross the Isthmus of Tehuantepec and produce intense upwelling in the gulf. This upwelling of cold, nutrient-rich waters induces high biological productivity and the dominance of the planktonic foraminiferal species Globigerina bulloides. Summer-fall oceanographic conditions are dominated by the northward flow of the Costa Rica Coastal Current and a stratified water column. Chlorophyll-a concentrations are much lower than during the upwelling season and the Globorotalia menardii assemblage is characteristic. The above pattern was recorded for most of the study period, except during ENSO conditions in winter 2007 and summer-fall of 2009. From mid-January to early March 2007, the assemblage was dominated by G. menardii instead of the typical G. bulloides. This period had the highest sea surface temperatures and lowest surface chlorophyll-a values recorded for the entire five year study period. During the similar time period of ENSO 2010, the G. bulloides assemblage shows the highest scores in the factor analysis, although the G. menardii assemblage also has somewhat high scores. Temperature is slightly lower and chlorophyll-a values are slightly higher than during 2007, suggesting the conditions were not strong enough to induce a change in faunal dominance. During ENSO 2009 (July 8th to November 12th), the summer-fall dominant assemblage of Globorotalia menardii was replaced by the Globigerinoides ruber - Globigerinita glutinata assemblage, associated to the summer-fall highest average temperatures and lowest chlorophyll-a concentrations at the studied site.

Determination of GHG and ammonia emissions from stored dairy cattle slurry by using a floating dynamic chamber.

PubMed

Minato, Keiko; Kouda, Yasuyuki; Yamakawa, Masaaki; Hara, Satoshi; Tamura, Tadashi; Osada, Takashi

2013-02-01

We developed a system for measuring emissions from stored slurry by using a floating dynamic chamber. CH(4) , CO(2) , N(2) O and NH(3) emitted from the storage tank of a dairy cattle farm in eastern Hokkaido were measured during summer 2008 (7/16-8/6), fall 2008 (10/2-10/26), spring 2009 (6/2-6/21) and winter 2009 (3/11). Average daily gas emission rates in summer, fall and spring were, respectively, 54.8, 54.2 and 34.3 g/m(2) for CH(4) ; 602, 274 and 254 g/m(2) for CO(2) ; 55.4, 68.2 and trace mg/m(2) for N(2) O; and 0.55, 0.73 and 0.46 g/m(2) for NH(3) . CH(4) , CO(2) and NH(3) emission rates during the brief measurement period in winter were reduced to 1/4, 1/23 and 1/2, respectively, of summer emission rate levels. All gas emissions showed diurnal fluctuation and were greatest during the daytime, when the ambient temperature rose. CH(4) , NH(3) and CO(2) emissions increased significantly during the daytime, and the daily emission (in grams) of each gas was positively correlated with maximum daily temperature. According to the combined spring, summer and fall measurements, the CH(4) , N(2) O and NH(3) annual emission factors were 1.42% (g CH(4) /g volatile solids), 0.02% (g N(2) O-N/g total N) and 0.43% (g NH(3) -N/g total N), respectively. © 2012 The Authors. Animal Science Journal © 2012 Japanese Society of Animal Science.

Characteristics of Fishes with the Potential to Cause Acoustic Clutter off Oregon and Washington during the Summer of 2012

DTIC Science & Technology

2014-05-10

14. Barboza, T., "West Coast sardine crash could radiate throughout ecosystem," Los Angeles Times, January 5, 2014. 15. Enticknap, B., Letter to the...AND SURVEYS Much of the Pacific sardine and Pacific hake stocks undertake annual north-south migrations . They migrate in late spring from off...California to the Pacific Northwest to feed during the summer. In the fall they migrate back to California to spawn during the winter and spring. The

SEASONAL VARIATIONS IN HUMAN PAROTID FLUID FLOW RATE IN A SUBTROPICAL CLIMATE.

DTIC Science & Technology

Parotid fluid was collected under conditions of very minimal stimulation from 3,868 systemically healthy young adult males over a period of two...calendar years. The study was carried out in a subtropical climate in which the only thermal discomfort resulted from the summer heat. Parotid flow rate...fall. During the summer months the mean rate of parotid flow was 0.031 ml./minute; during the winter the flow rate mean increased by 35% to 0.042 ml

Lighting Condition Analysis for Mars' Moon Phobos

NASA Technical Reports Server (NTRS)

Li, Zu Qun; de Carufel, Guy; Crues, Edwin Z.; Bielski, Paul

2016-01-01

This study used high fidelity computer simulation to investigate the lighting conditions, specifically the solar radiation flux over the surface, on Phobos. Ephemeris data from the Jet Propulsion Laboratory (JPL) DE405 model was used to model the state of the Sun, Earth, Moon, and Mars. An occultation model was developed to simulate Phobos' self-shadowing and its solar eclipses by Mars. The propagated Phobos state was compared with data from JPL's Horizon system to ensure the accuracy of the result. Results for Phobos lighting conditions over one Martian year are presented, which include the duration of solar eclipses, average solar radiation intensity, surface exposure time, and radiant exposure for both sun tracking and fixed solar arrays. The results show that: Phobos' solar eclipse time varies throughout the Martian year, with longer eclipse durations during the Martian northern spring and fall seasons and no eclipses during the Martian northern summer and winter seasons; solar radiation intensity is close to minimum in late spring and close to maximum in late fall; exposure time per orbit is relatively constant over the surface during the spring and fall but varies with latitude during the summer and winter; and Sun tracking solar arrays generate more energy than a fixed solar array. A usage example of the result is also present in this paper to demonstrate the utility.

Greenland Subglacial Drainage Evolution Regulated by Weakly Connected Regions of the Bed

NASA Technical Reports Server (NTRS)

Hoffman, Matthew J.; Andrews, Lauren C.; Price, Stephen F.; Catania, Ginny A.; Neumann, Thomas A.; Luthi, Martin P.; Gulley, Jason; Ryser, Claudia; Hawley, Robert L.; Morriss, Blaine

2016-01-01

Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. These results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology.

Greenland subglacial drainage evolution regulated by weakly connected regions of the bed

PubMed Central

Hoffman, Matthew J.; Andrews, Lauren C.; Price, Stephen A.; Catania, Ginny A.; Neumann, Thomas A.; Lüthi, Martin P.; Gulley, Jason; Ryser, Claudia; Hawley, Robert L.; Morriss, Blaine

2016-01-01

Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. These results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology. PMID:27991518

Greenland subglacial drainage evolution regulated by weakly connected regions of the bed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, Matthew J.; Andrews, Lauren C.; Price, Stephen A.

Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage ofmore » water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. Finally, these results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology.« less

Greenland subglacial drainage evolution regulated by weakly connected regions of the bed.

PubMed

Hoffman, Matthew J; Andrews, Lauren C; Price, Stephen A; Catania, Ginny A; Neumann, Thomas A; Lüthi, Martin P; Gulley, Jason; Ryser, Claudia; Hawley, Robert L; Morriss, Blaine

2016-12-19

Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. These results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology.

Greenland subglacial drainage evolution regulated by weakly connected regions of the bed

DOE PAGES

Hoffman, Matthew J.; Andrews, Lauren C.; Price, Stephen A.; ...

2016-12-19

Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage ofmore » water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. Finally, these results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology.« less

Greenland subglacial drainage evolution regulated by weakly connected regions of the bed

NASA Astrophysics Data System (ADS)

Hoffman, Matthew J.; Andrews, Lauren C.; Price, Stephen A.; Catania, Ginny A.; Neumann, Thomas A.; Lüthi, Martin P.; Gulley, Jason; Ryser, Claudia; Hawley, Robert L.; Morriss, Blaine

2016-12-01

Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of water and lowering of water pressure in weakly connected regions of the bed can explain the dominant features in late and post melt season ice dynamics. These results suggest that a third weakly connected drainage component should be included in the conceptual model of subglacial hydrology.

Diet and physical activity in African-American girls: Seasonal differences

USDA-ARS?s Scientific Manuscript database

Diet and physical activity (PA) may vary by season. Two 24-hour dietary recalls and 7 days of accelerometry were collected from 342 8-10 year-old African-American girls between January 2013 and October 2014. Season was based on time of data collection (fall, spring, winter, summer). Seasonal differe...

Basin-Scale Variation in the Spatial Pattern of Fall Movement of Juvenile Coho Salmon in the West Fork Smith River, Oregon

EPA Science Inventory

For several species of salmonids (Oncorhynchus and Salvelinus spp.) inhabiting Pacific coastal temperate streams, juvenile fish have been recorded moving between mainstem and tributary habitats during the transition from the summer dry season to the winter wet season. Movement co...

Microhabitat Characteristics of sites used by swamp rabbits

Treesearch

Patrick A. Zollner; Winston P. Smith; Leonard A. Brennan

2000-01-01

The swamp rabbit (Sylvilagus aquaticus) is one of the least studied North American lagomorphs; a better understanding of the habitat types it uses will improve management of this species. We studied microhabitat characteristics of sites associated with specific behaviors of the swamp rabbit. During spring-summer (15 April-1 October) and fall-winter (...

Recovery of hemlock woolly adelgid predators in the high country of northwestern North Carolina, 2004-2008

Treesearch

Richard McDonald; David Mausel; Scott Salom; Loke Kok; Michael Montgomery; Gina Luker; Stan Steury; Gene Spears; Stewart Skeate; James Graham; Byron Hamstead.

2008-01-01

Three species of predatory beetles have been released to combat infestations of the hemlock woolly adelgid in the High Country region of northwestern North Carolina. They are the spring/summer predators Sasajiscymnus tsugae Sasaji (St), Scymnus sinuanodulus Yu and Yao (Ss), and the winter/fall...

Speak Out for Children. Winter 1992/1993 through Summer/Fall 1994.

ERIC Educational Resources Information Center

Levy, David L., Ed.; Diamond, Elliott H., Ed.

1993-01-01

"Speak Out for Children" is the quarterly newsletter of the Children's Rights Council (CRC), which is concerned with the healthy development of children of divorced and separated parents. The newsletter consists of feature articles and regular sections and columns. Feature articles of Volume 8, Number 1 are: "The Controversial Truth: Two-Parent…

Tip-Dieback in Young Loblolly Pine Plantations

Treesearch

David B. South; Patrick Brown; Phillip M. Dougherty; Sonya Olykan; Brett Runion; Adya Singh; Malcolm Skinner

2002-01-01

Dieback of loblolly pine (Pinus taeda L.) has been observed in certain intensively managed plantations throughout the South. There are two distinct types of dieback; winter dieback usually appears in February and March while summer dieback appears in July (or later) and increases during the fall. Both types have very high levels of K in terminal...

Soil erosion and deposition before and after fire in oak savannas

Treesearch

Peter F. Ffolliott; Gerald J. Gottfried; Hui Chen; Aaron T. Kauffman; Cody L. Stropki; Daniel G. Neary

2013-01-01

Effects of low severity prescribed burning treatments and a wildfire on soil erosion and deposition in the oak savannas in the Southwestern Borderlands are reported. Measurements in the spring and fall, respectively, characterize soil movements following winter rains and high-intensity summer rainstorms. Annual values are also presented. Relationships between soil...

The Forum, Volume 8, Numbers 1-4, Spring, Summer, Fall, Winter 1982.

ERIC Educational Resources Information Center

Foster, Herbert L., Ed.

1982-01-01

The four volumes of the journal focus on themes of New York state's services for youth, postsecondary institutions, and handicapped students; current special education concerns and practices in New York state; and issues related to the education of severely and profoundly handicapped students. The first of these journals "New York State…

Drinking water systems, hydrology, and childhood gastrointestinal illness in Central and Northern Wisconsin.

PubMed

Uejio, Christopher K; Yale, Steven H; Malecki, Kristen; Borchardt, Mark A; Anderson, Henry A; Patz, Jonathan A

2014-04-01

This study investigated if the type of drinking water source (treated municipal, untreated municipal, and private well water) modifies the effect of hydrology on childhood (aged < 5 years) gastrointestinal illness. We conducted a time series study to assess the relationship between hydrologic and weather conditions with childhood gastrointestinal illness from 1991 to 2010. The Central and Northern Wisconsin study area includes households using all 3 types of drinking water systems. Separate time series models were created for each system and half-year period (winter/spring, summer/fall). More precipitation (summer/fall) systematically increased childhood gastrointestinal illness in municipalities accessing untreated water. The relative risk of contracting gastrointestinal illness was 1.4 in weeks with 3 centimeters of precipitation and 2.4 in very wet weeks with 12 centimeters of precipitation. By contrast, gastrointestinal illness in private well and treated municipal areas was not influenced by hydrologic conditions, although warmer winter temperatures slightly increased incidence. Our study suggests that improved drinking water protection, treatment, and delivery infrastructure may improve public health by specifically identifying municipal water systems lacking water treatment that may transmit waterborne disease.

Performance evaluation of Ormat unit at Wabuska, Nevada. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Culver, G.

1986-07-01

Three nominal 24 hour tests under summer, winter and spring weather conditions, were run on an Ormat geothermal binary power generation machine. The machine, located at TAD's Enterprises in Wabuska, Nevada is supplied with approximately 830 gpm of geothermal water at 221/sup 0/F and has two spray cooling ponds. During the tests, temperature, pressure, and flows of geothermal water, freon, cooling water and instantaneous electrical production were recorded hourly. At least once during each test, energy consumption of the well pump, freon feed pump and cooling water pumps were made. Power output of the machine is limited by spray pondmore » capacity. Net output ranged from 410.2 kW during summer conditions when cooling water was 65/sup 0/F to 610.4 kW during winter conditions when cooling water was 55/sup 0/F. Net resource utilization ranged from 1.005 Whr/lb during the summer test to 1.55 Whr/lb during the winter test. Spray pond performance averaged 63% for the fall and winter tests. Availability of the Ormat unit itself during the eight month test period was generally good, averaging 95.5%. Overall system availability, including well pumps, cooling system and electric grid was somewhat less - averaging 83%.« less

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

NASA Astrophysics Data System (ADS)

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%).

Sea ice radar signatures from ERS-1 SAR during late Summer and Fall in the Beaufort and Chukchi Seas

NASA Technical Reports Server (NTRS)

Holt, Benjamin; Cunningham, Glenn; Kwok, Ron

1993-01-01

A study which examines ERS-1 C band SAR (Synthetic Aperture Radar) imagery of sea ice obtained in the Beaufort and Chukchi Seas from mid Summer through Fall freeze up and early Winter in 1991 is presented. Radar backscatter statistics of sea ice were obtained from the imagery, using common floes tracked through consecutive repeat images whenever possible. During the Summer months, strong fluctuations in ice signatures of several dB are observed over 2 to 3 day periods, which are found to be closely related to air temperature excursions above and below freezing that alters the phase of the ice surface. As air temperatures drop steadily below freezing in the Fall, the signatures of the pack ice increase in brightness and become more stable with time. Multiyear ice is distinguished from rough and smooth first year ice. There are also variations in the multiyear signatures with latitude. Large variations are seen in new ice and open water contained within leads which results in ambiguous classification.

Seasonal carcass composition and energy balance of female black ducks in Maine

USGS Publications Warehouse

Reinecke, K.J.; Stone, T.L.; Owen, R.B.

1982-01-01

Female Black Ducks (Anas rubripes) collected in Maine during the summer, fall, and winter of 1974-1976 showed significant seasonal variation in body weight, nonfat dry weight, gizzard and pectoral muscle weight, and fat, moisture, and protein content. Variation of body weight within and among seasons was correlated more strongly with carcass protein content, and with fat content during seasons of heavy lipid deposition, than with three structural size variables (culmen, tarsus, and sternum). Regression equations including fat and protein as independent variables accounted for 80-90% of the annual and seasonal variation in body weight; structural size variables alone accounted for less than 30%. Immature females averaged 54 and 99 g lighter, and carried 54 and 59 g less fat than adults during the fall and winter. Ducks of both age classes lost weight in December and January. Adult and immature females metabolized 59 and 64 g of fat and 17 and 25 g of protein in winter compared with 46 g of fat during the nesting season. Nutrient reserves are thus equally as important for the winter survival of these birds as for successfurl eproduction. Seasonal changes in carcass composition suggest that (1) fat deposited in late fall provides an energy reserve during winter, (2) a reduction in lean weight during winter may lower daily energy requirements and increase the effective amount of energy reserves, and (3) declining body weights during late winter may be an endogenous rhythm that reflects a shift in the expected benefits of an energy reserve compared to the costs of carrying additional weight,

Effect of season on reproductive behaviors and fertilization success in cavies (Cavia aperea).

PubMed

Hribal, Romy; Rübensam, Kathrin; Bernhardt, Sandra; Jewgenow, Katarina; Guenther, Anja

2018-04-05

Finding the optimal timing for breeding is crucial for small mammals to ensure survival and maximize lifetime reproductive success. Species living in temperate regions therefore often restrict breeding to seasons with favorable food and weather conditions. Although caviomorph rodents such as guinea pigs are described as non-seasonal breeders, a series of recent publications has shown seasonal adaptations in litter size, offspring birth mass and maternal investment. Here, we aim to test if seasonal patterns of litter size variation found in earlier studies, are mediated by seasonal differences in female estrus length, fertilization rate and mating behavior. The female estrus period was longer in fall compared to all other seasons (p < 0.001), frequently lasting 7-9 days while estrus in spring usually lasted less than 2 days. In fall, females mated later during estrus (p < 0.001), resulting in reduced fertilization rates (p < 0.001). Fertilization rate was well above 95% in summer while it dropped to less than 85% in fall and winter. While none of the male mating characteristics such as number and duration of copulations differed across seasons, the number of mating bouts was reduced in fall (p = 0.04). Finally, the developmental stages of flushed embryos were more diverse in spring and summer compared to fall and winter. These results suggest that seasonal differences in fertilization rate and quality of implanted embryos are mediated by female estrus length and timing and intensity of mating behavior. Together, these effects contribute to the observed differences in litter size across seasons. Copyright © 2018 Elsevier Inc. All rights reserved.

Dinoflagellate cysts and bloom events at Todos Santos Bay, Baja California, México, 1999 2000

NASA Astrophysics Data System (ADS)

Peña-Manjarrez, José Luis; Helenes, Javier; Gaxiola-Castro, Gilberto; Orellana-Cepeda, Elizabeth

2005-07-01

Forty-two species of dinoflagellate motile cells and 18 species of organic-walled dinoflagellate resting cysts were identified in samples collected at Todos Santos Bay, Baja California, México, from September 1999 to June 2000. These temperate to cool-temperate species belong mainly to the families Gonyaulacaceae and Protoperidiniaceae. Lingulodinium polyedrum (Stein, 1883) Dodge 1989 was the dominant species both in the sediments and water column. During this period we observed planktonic motile cells, temporary cysts with cellulose walls, and resting cysts with resistant dinosporin walls. Two dinoflagellate blooms occurred in the spring to summer of 2000 allowing us to observe the timing of cyst production. The temporary cysts appeared between these blooms and also in the summer, whereas the resting cysts appeared during the preceding fall and winter. Resting cysts appeared in colder conditions, whereas the temporary cysts were produced within a particular thermal window and under nutrient depletion. Resting cysts were concentrated in discrete areas at depths of less than 25 m, and associated with sediments ranging from silt to fine sand. These cysts were abundant in the surface sediments during summer, fall and winter, whereas the motile cells dominated during the spring and summer, when the two L. polyedrum blooms were observed. The abundance of cells in the plankton, comprising motile cells and temporary cysts, appears to be inversely proportional to the concentration of resting cysts of the same species in the surface sediments.

Toxicity of parathion to captive European starlings (Sturnus vulgaris)-absence of seasonal effects

USGS Publications Warehouse

Rattner, B.A.; Grue, C.E.

1990-01-01

The effects of season on the toxicity of the prototypic organophosphorus insecticide parathion was evaluated using adult European starlings (Sturnus vulgaris) housed in outdoor pens. Groups of birds received oral doses of parathion in the fall, winter, spring and summer. Median lethal dosage, and brain and plasma cholinesterase inhibition, were found to be quite similar among seasons. Parathion may have been more toxic during hot weather (winter vs. summer LD50 estimate: 160 vs. 118 mg/kg; p < 0.1). In view of previous reports in which ambient temperature extremes and harsh weather have enhanced organophosphorus insecticide toxicity to birds, it is concluded that circannual toxicity studies should include measures of sensitivity (acute oral exposure) and vulnerability (dietary exposure) to better predict responses of free-ranging birds.

Survey of conditions for artificial aurora experiments at EISCAT Tromsø using dynasonde data

NASA Astrophysics Data System (ADS)

Tsuda, T. T.; Rietveld, M. T.; Kosch, M. J.; Oyama, S.; Hosokawa, K.; Nozawa, S.; Kawabata, T.; Mizuno, A.; Ogawa, Y.

2018-03-01

We report a brief survey on conditions for artificial aurora optical experiments in F region heating with O-mode at the EISCAT Tromsø site using dynasonde data from 2000 to 2017. The results obtained in our survey indicate the following: The possible conditions for conducting artificial aurora experiments are concentrated in twilight hours in both evening and morning, compared with late-night hours; the possible conditions appear in fall, winter, and spring, while there is no chance in summer, and the month-to-month variation among fall, winter, and spring is not clear. The year-to-year variation is well correlated with the solar cycle, and experiments during the solar minimum would be almost hopeless. These findings are useful for planning future artificial aurora optical experiments.

Tomicus piniperda (Coleaoptera: Scolytidae) Within and Between Tree Movement When Migrating to Overwintering Sites

Treesearch

Ye Hui; Robert A. Haack; Toby R. Petrice

2002-01-01

Tomicus piniperda (L.) (Coleoptera: Scolytidae) is a univoltine bark beetle that conducts maturation feeding inside shoots of pine (Pinus) trees during summer and fall. In the northern portion of its range, where freezing winter temperatures occur, adults overwinter in the outer bark at the base of live pine trees. In the present...

Vacation Study Abroad, 1991: An IIE Guide to Study Abroad.

ERIC Educational Resources Information Center

Steen, Sara J., Ed.; Battle, Ed, Ed.

This directory provides information on summer higher education programs ranging from 1 week to several months, and on short courses of varying lengths in the fall, winter, and spring that take place in countries other than the United States. An introductory section describes the organization of the listings, which provide program sponsor and name,…

Habitat usage by prairie grouse on the Sheyenne National Grasslands

Treesearch

Llewellyn L. Manske; William T. Barker

1988-01-01

Prairie grouse habitat usage was observed for six years. Spring and summer habitat usage was primarily in the upland and midland grassland habitat types. Habitat usage shifted during the fall and winter to cropland and associated tree shelterbelts. The switchgrass plant community was the primary concealment cover for nesting and roosting. Cropland and associated tree...

Composition and Digestibility of Deer Browse in Southern Forests

Treesearch

Henry L. Short; Robert M. Blair; E.A. Epps

1975-01-01

Twigs were most nutritious and digestible during early growth in spring; they were high in fiber content and low in digestibility during summer, autumn, and winter. Evergreen leaves did not vary substantially in nutrient content and digestibility throughout the year. By contrast, leaves of deciduous species were reduced in quality and digestibility after leaf-fall....

Seasonal carcass composition and energy balance of female black ducks in Maine

Treesearch

Kenneth J. Reinecke; Timothy L. Stone; Ray B., Jr. Owen

1982-01-01

Female Black Ducks (Anas rubripes) collected in Maine during the summer, fall, and winter of 1974-1976 showed significant seasonal variation in body weight, nonfat dry weight, gizzard and pectoral muscle weight, and fat, moisture, and protein content. Variation of body weight within and among seasons was correlated more strongly with carcass protein...

Tracking Climate Change through the Spatiotemporal Dynamics of the Teletherms, the Statistically Hottest and Coldest Days of the Year

DOE PAGES

Dodds, Peter Sheridan; Mitchell, Lewis; Reagan, Andrew J.; ...

2016-05-11

Instabilities and long term shifts in seasons, whether induced by natural drivers or human activities, pose great disruptive threats to ecological, agricultural, and social systems. Here, we propose, measure, and explore two fundamental markers of location-sensitive seasonal variations: the Summer and Winter Teletherms—the on-average annual dates of the hottest and coldest days of the year. We analyze daily temperature extremes recorded at 1218 stations across the contiguous United States from 1853–2012, and observe large regional variation with the Summer Teletherm falling up to 90 days after the Summer Solstice, and 50 days for the Winter Teletherm after the Winter Solstice.more » We show that Teletherm temporal dynamics are substantive with clear and in some cases dramatic shifts reflective of system bifurcations. We also compare recorded daily temperature extremes with output from two regional climate models finding considerable though relatively unbiased error. In conclusion, our work demonstrates that Teletherms are an intuitive, powerful, and statistically sound measure of local climate change, and that they pose detailed, stringent challenges for future theoretical and computational models.« less

Annual movements of a steppe eagle (Aquila nipalensis) summering in Mongolia and wintering in Tibet

USGS Publications Warehouse

Ellis, D.H.; Moon, S.L.; Robinson, J.W.

2001-01-01

An adult female steppe eagle (Aquila nipalensis Hodgson) was captured and fitted with a satellite transmitter in June 1995 in southeastern Mongolia. In fall, it traveled southwest towards India as expected, but stopped in southeastern Tibet and wintered in a restricted zone within the breeding range of the steppe eagle. In spring, the bird returned to the same area of Mongolia where it was captured. These observations, though derived from the movements of a single bird, suggest three things that are contrary to what is generally believed about steppe eagle biology. First, not all steppe eagles move to warmer climes in winter. Second, not all steppe eagles are nomadic in winter. Finally, because our bird wintered at the periphery of the steppe eagle breeding range in Tibet, perhaps birds that breed in this same area also winter there. If so, not all steppe eagles are migratory.

Composition and stability of coyote families and territories in North Dakota

USGS Publications Warehouse

Allen, S.H.; Hastings, J.O.; Kohn, S.C.

1987-01-01

Coyote (Canis latrans) families studied in North Dakota during 1976 to 1978 contained three or more adults during the spring-summer season, and they occupied large contiguous, non-overlapping territories. Coyote territories averaged 61 km2 during the spring-summer season and 30 km2 during fall-winter season. Three of four families occupied territories that were similar in size for two consecutive years; however, boundaries changed within individual families when one or both alpha adults were killed. All coyotes replacing dead alpha adults were 1 year old.

Role of photoperiod and melatonin in seasonal acclimatization of the djungarian hamster, Phodopus sungorus

NASA Astrophysics Data System (ADS)

Steinlechner, S.; Heldmaier, G.

1982-12-01

The Djungarian hamster, Phodopus sungorus, shows a clear annual cycle in some thermogenic parameters such as nonshivering thermogenesis (NST) and cold resistance. These seasonal changes were found to be basically controlled by natural changes in photoperiod. Further support for this view was obtained by exposing the hamsters to artificial long and short photoperiods. Implantation of melatonin during fall and winter results in an increased thermogenic capacity in both short and long day hamsters comparable to that shown by values of control hamsters exposed to short photoperiods during winter. This thermotropic action of melatonin and of short photoperiod could be found only in fall and winter whereas during spring and summer, melatonin, like photoperiod, had no influence on thermogenic capacities. These results show that the actions of melatonin and photoperiod vary with the season and that they depend upon the photoperiodic history of the hamsters. Our results further indicate that the pineal gland with its hormone melatonin is involved in mediation of photoperiodic control of seasonal acclimatization.

Historical Change of Equilibrium Water Temperature in Japan

NASA Astrophysics Data System (ADS)

Miyamoto, H.

2015-12-01

Changes in freshwater ecosystems due to a climate change have been great concern for sustainable river basin management both for water resources utilization and ecological conservation. However, their impact seems to be difficult to evaluate because of wide variety of basin characteristics along a river network both in nature and social environment. This presentation uses equilibrium water temperature as a simple criterion index for evaluating the long-term changes of stream thermal environment due to the historical climate change in Japan. It examines, at first, the relationship between the equilibrium water temperature and the stream temperature observed for 7 years at a lower reach in the Ibo River, Japan. It analyzes, then, the seasonal and regional trends of the equilibrium water temperature change for the last 50 years at 133 meteorological station sites throughout Japan, discussing their rising or falling characteristics. The correlation analysis at the local reach of the Ibo River shows that the equilibrium water temperature has similar trend of change as the stream temperature. However, its value tends to be higher than the stream temperature in summer, while lower in winter. The onset of the higher equilibrium water temperature fluctuates annually from mid February to early April. This onset fluctuation at each spring could be influenced by the different amount of snow at the antecedent winter. The rising or falling trends of the equilibrium water temperature are analyzed both annually and seasonally through the regression analysis of the 133 sites in Japan. Consequently, the trends of the temperature change could be categorized by 12 patterns. As for the seasonal analysis, the results shows that there are many sites indicating the falling trend in spring and summer, and rising trends in autumn and winter. In particular, winter has the strong rising tendency throughout Japan. As for the regional analysis, the result illustrates the precise rationality; e.g., northern parts of Japan show the temperature fall in spring and the temperature rise in autumn, while the urbanized regions along the Pacific coastline indicate the temperature rise in all the four seasons.

Seasonal variation in functional properties of microbial communities in beech forest soil

PubMed Central

Koranda, Marianne; Kaiser, Christina; Fuchslueger, Lucia; Kitzler, Barbara; Sessitsch, Angela; Zechmeister-Boltenstern, Sophie; Richter, Andreas

2013-01-01

Substrate quality and the availability of nutrients are major factors controlling microbial decomposition processes in soils. Seasonal alteration in resource availability, which is driven by plants via belowground C allocation, nutrient uptake and litter fall, also exerts effects on soil microbial community composition. Here we investigate if seasonal and experimentally induced changes in microbial community composition lead to alterations in functional properties of microbial communities and thus microbial processes. Beech forest soils characterized by three distinct microbial communities (winter and summer community, and summer community from a tree girdling plot, in which belowground carbon allocation was interrupted) were incubated with different 13C-labeled substrates with or without inorganic N supply and analyzed for substrate use and various microbial processes. Our results clearly demonstrate that the three investigated microbial communities differed in their functional response to addition of various substrates. The winter communities revealed a higher capacity for degradation of complex C substrates (cellulose, plant cell walls) than the summer communities, indicated by enhanced cellulase activities and reduced mineralization of soil organic matter. In contrast, utilization of labile C sources (glucose) was lower in winter than in summer, demonstrating that summer and winter community were adapted to the availability of different substrates. The saprotrophic community established in girdled plots exhibited a significantly higher utilization of complex C substrates than the more plant root associated community in control plots if additional nitrogen was provided. In this study we were able to demonstrate experimentally that variation in resource availability as well as seasonality in temperate forest soils cause a seasonal variation in functional properties of soil microorganisms, which is due to shifts in community structure and physiological adaptations of microbial communities to altered resource supply. PMID:23645937

Ammonia emission from a permanent grassland on volcanic soil after the treatment with dairy slurry and urea

NASA Astrophysics Data System (ADS)

Salazar, F.; Martínez-Lagos, J.; Alfaro, M.; Misselbrook, T.

2014-10-01

Ammonia (NH3) is an air pollutant largely emitted from agricultural activities including the application of livestock manures and fertilizers to grassland. This gas has been linked with important negative impacts on natural ecosystems. In southern Chile, the use of inorganic and organic fertilizers (e.g. slurries) has increased in cattle production systems over recent years, heightening the risk of N losses to the wider environment. The objectives of this study were to evaluate on permanent grasslands on a volcanic ash soil in southern Chile: 1) the N loss due to NH3 volatilization following surface application of dairy slurry and urea fertilizer; and 2) the effect of a urease inhibitor on NH3 emissions from urea fertilizer application. Small plot field experiments were conducted over spring, fall, winter and summer seasons, using a system of wind tunnels to measure ammonia emissions. Ammonia losses ranged from 1.8 (winter) to 26.0% (fall) and 3.1 (winter) to 20.5% (summer) of total N applied for urea and slurry, respectively. Based on the readily available N applied (ammoniacal N for dairy slurry and urea N for urea fertilizer), losses from dairy slurry were much greater, at 16.1 and 82.0%, for winter and summer, respectively. The use of a urease inhibitor proved to be an effective option to minimize the N loss due NH3 volatilization from urea fertilizer, with an average reduction of 71% across all seasons. The results of this and other recent studies regarding N losses suggest that ammonia volatilization is the main pathway of N loss from grassland systems in southern Chile on volcanic ash soils when urea and slurry are used as an N source. The use of good management practices, such as the inclusion of a urease inhibitor with urea fertilizer could have a beneficial impact on reducing N losses due NH3 volatilization and the environmental and economic impact of these emissions.

Exchange of nitrogen and phosphorus between a shallow lagoon and coastal waters

USGS Publications Warehouse

Hayn, Melanie; Howarth, Robert W.; Ganju, Neil K.; Berg, Peter; Foreman, Kenneth H.; Giblin, Anne E.; McGlathery, Karen

2014-01-01

West Falmouth Harbor, a shallow lagoon on Cape Cod, has experienced a threefold increase in nitrogen load since the mid- to late 1990s due to input from a groundwater plume contaminated by a municipal wastewater treatment plant. We measured the exchange of nitrogen and phosphorus between the harbor and the coastal waters of Buzzards Bay over several years when the harbor was experiencing this elevated nitrogen load. During summer months, the harbor not only retained the entire watershed nitrogen load but also had a net import of nitrogen from Buzzards Bay. During the spring and fall, the harbor had a net export of nitrogen to Buzzards Bay. We did not measure the export in winter, but assuming the winter net export was less than 112 % of the load, the harbor exported less than half of the watershed nitrogen load on an annual basis. For phosphorus, the harbor had a net import from coastal waters in the spring and summer months and a net export in the fall. Despite the large increase in nitrogen load to the harbor, the summertime import of phosphorus from Buzzards Bay was sufficient to maintain nitrogen limitation of primary productivity during the summer. Our findings illustrate that shallow systems dominated by benthic producers have the potential to retain large terrestrial nitrogen loads when there is sufficient supply of phosphorus from exchange with coastal waters.

Elevated streamflows increase dam passage by juvenile coho salmon during winter: Implications of climate change in the Pacific Northwest

USGS Publications Warehouse

Kock, Tobias J.; Liedtke, Theresa L.; Rondorf, Dennis W.; Serl, John D.; Kohn, Mike; Bumbaco, Karin A.

2012-01-01

A 4-year evaluation was conducted to determine the proportion of juvenile coho salmon Oncorhynchus kisutch passing Cowlitz Falls Dam, on the Cowlitz River, Washington, during winter. River and reservoir populations of coho salmon parr were monitored using radiotelemetry to determine if streamflow increases resulted in increased downstream movement and dam passage. This was of interest because fish that pass downstream of Cowlitz Falls Dam become landlocked in Riffe Lake and are lost to the anadromous population. Higher proportions of reservoir-released fish (0.391-0.480) passed Cowlitz Falls Dam than did river-released fish (0.037-0.119). Event-time analyses demonstrated that streamflow increases were important predictors of dam passage rates during the study. The estimated effect of increasing streamflows on the risk of dam passage varied annually and ranged from 9% to 75% for every 28.3 m3/s increase in streamflow. These results have current management implications because they demonstrate the significance of dam passage by juvenile coho salmon during winter months when juvenile fish collection facilities are typically not operating. The results also have future management implications because climate change predictions suggest that peak streamflow timing for many watersheds in the Pacific Northwest will shift from late spring and early summer to winter. Increased occurrence of intense winter flood events is also expected. Our results demonstrate that juvenile coho salmon respond readily to streamflow increases and initiate downstream movements during winter months, which could result in increased passage at dams during these periods if climate change predictions are realized in the coming decades.

Characterizing seasonal and diel vertical movement and habitat use of lake whitefish (Coregonus clupeaformis) in Clear Lake, Maine

USGS Publications Warehouse

Zydlewski, Joseph D.; Gorsky, Dimitry; Balsey, David

2016-01-01

Seasonal and daily vertical activity of lake whitefish Coregonus clupeaformis was studied in Clear Lake, Maine (253 ha), using acoustic telemetry from November 2004 to June 2009. Twenty adult lake whitefish were tagged with acoustic tags that had either a depth sensor or both depth and temperature sensors to assess vertical habitat use at a seasonal and daily resolution. Vertical habitat selection varied seasonally and was strongly influenced by temperature. Between December and April, when the lake was covered with ice, surface temperature was below 2°C and tagged individuals occupied deep areas of the lake (∼15 m). After ice-out, fish ascended into shallow waters (∼5 m), responding to increased water temperature and possibly to greater foraging opportunity. When surface water temperatures exceeded 20°C, fish descended below the developing thermocline (∼9 m), where they remained until surface temperatures fell below 20°C; fish then ascended into shallower depths, presumably for feeding and spawning. Through the winter, fish remained in thermal habitats that were warmer than the surface temperatures; in the summer, they selected depths with thermal habitats below 15°C. Though the amplitude varied greatly across seasons, lake whitefish displayed a strong diurnal pattern of activity as measured by vertical velocities. Fish were twofold more active during spring, summer, and fall than during winter. Lake whitefish exhibited diel vertical migrations, rising in the water column during nighttime and occupying deeper waters during the day. This pattern was more pronounced in the spring and fall and far less prominent during winter and summer. The strong linkage between temperature and habitat use may limit the current range of lake whitefish and may be directly impacted by climatic change.

Female white-tailed deer survival across ecoregions in Minnesota and South Dakota

USGS Publications Warehouse

Grovenburg, T.W.; Swanson, C.C.; Jacques, C.N.; Deperno, C.S.; Klaver, R.W.; Jenks, J.A.

2011-01-01

Survival and cause-specific mortality of female white-tailed deer (Odocoileus virginianus) have been well documented in forested and agricultural landscapes, but limited information has been collected in grassland habitats typical of the Northern Great Plains. Our objectives were to document and compare survival and cause-specific mortality of adult female white-tailed deer in four distinct ecoregions. We captured and radiocollared 190 (159 adult, 31 yearling) female white-tailed deer and monitored (including deer from a previous study) a total of 246 (215 adult, 31 yearling) deer from Jan. 2000 to Dec. 2007. We documented 113 mortalities; hunting (including wounding loss) accounted for 69.9% of all mortalities and vehicle collisions accounted for an additional 15.0%. Natural causes (e.g., disease, predation) of mortality were minor compared to human-related causes (e.g., hunting, vehicle collisions). We used known fate modeling in program MARK to estimate survival rates and compare ecoregions and seasons. Model {Sseason (winter = summer)} had the lowest AICc value suggesting that survival differed only between seasons where winter and summer survival was equal and differed with fall season. Annual and seasonal (summer, fall, winter) survival rates using the top model {Sseason (summer = winter)} were 0.76 (95% ci  =  0.70–0.80), 0.97 (95% ci  =  0.96–0.98), 0.80 (95% ci  =  0.76–0.83) and 0.97 (95% ci  =  0.96–0.98), respectively. High human-related mortality was likely associated with limited permanent cover, extensive road networks and high hunter density. Deer management in four distinct ecoregions relies on hunter harvest to maintain deer populations within state management goals.

Organization and seasonal quantification of the intertubular compartment in the bat Molossus molossus (Pallas, 1776) testis.

PubMed

Morais, Danielle Barbosa; De Oliveira, Luciana Coutinho; Carmo Cupertino, Marli Do; De Freitas, Karine Moura; De Freitas, Mariella Bontempo Duca; De Paula, Tarcízio Antônio Rêgo; Da Matta, Sérgio Luis Pinto

2013-01-01

Environmental factors can influence the reproductive rates in bats, and since morphometric information of bats testis is scarce, we aimed to compare the organization and quantification of the intertubular components in the testes of the bat Molossus molossus, collected in different seasons. Testicular histological sections were evaluated using light and electron microscopy. The intertubular compartment occupied an average 10% of the testes, being predominately constituted of Leydig cells (LC). The percentages of the testes occupied by the intertubular compartment and by LC were significantly higher in summer, while the other intertubular components did not vary significantly among the seasons. As suspected under light microscopy, the ultrastructural analysis confirmed the existence of multinucleated LC during winter. The increase in the nuclear percentage of LC in winter seems to have caused the decrease of the cytoplasmatic measurements in that season, as well as in the volume of LC. The highest cytoplasmatic values and volume of LC registered in the spring, summer, and fall can be related to greater activity of this cell in these seasons. The higher investment in intertubular tissue and in LC observed in summer, compared to winter; suggest an increase in the steroidogenic capacity of this bat during summer. The analyses correlating testicular morphometry and abiotic environmental factors in this study confirm the influence of climatic factors on the reproduction of M. molossus. Copyright © 2012 Wiley Periodicals, Inc.

Seasonal changes in daily metabolic patterns of tegu lizards (Tupinambis merianae) placed in the cold (17 degrees C) and dark.

PubMed

Milsom, William K; Andrade, Denis V; Brito, Simone P; Toledo, Luis F; Wang, Tobias; Abe, Augusto S

2008-01-01

Abstract Oxygen consumption rate was measured continuously in young tegu lizards Tupinambis merianae exposed to 4 d at 25 degrees C followed by 7-10 d at 17 degrees C in constant dark at five different times of the year. Under these conditions, circadian rhythms in the rate of oxygen consumption persisted for anywhere from 1 d to the entire 2 wk in different individuals in all seasons except the winter. We also saw a progressive decline in standard oxygen consumption rate (at highly variable rates in different individuals) to a very low rate that was seasonally independent (ranging from 19.1 +/- 6.2 to 27.7 +/- 0.2 mL kg(-1) h(-1) across seasons). Although this degree of reduction appeared to take longer to invoke when starting from higher metabolic rates, tegu lizards reduced their metabolism to the low rates seen in winter dormancy at all times of the year when given sufficient time in the cold and dark. In the spring and summer, tegus reduced their standard metabolic rate (SMR) by 80%-90% over the experimental run, but only roughly 20%-30% of the total fall was due to the reduction in temperature; 70%-80% of the total fall occurred at constant temperature. By autumn, when the starting SMR on the first night at 25 degrees C was already reduced by 59%-81% (early and late autumn, respectively) from peak summer values, virtually all of the fall (63%-83%) in metabolism was due to the reduction in temperature. This suggests that the temperature-independent reduction of metabolism was already in place by autumn before the tegus had entered winter dormancy.

Annual Soil Temperature Wave at Four Depths in Southwestern Wisconsin

Treesearch

Richard S. Sartz

1967-01-01

Soil temperature was measured for a year on a southeast-facing slope of 25 percent, latitude 43 degrees 50 minutes N. The spring-summer cover was unmowed alfalfa-bluegrass meadow, the fall-winter cover, meadow stubble. Snow cover was light or absent. The soil was Fayette silt loam, valley phase. The annual temperature wave at all depths followed the air temperature...

Improving plantation establishment by optimizing growth capacity and planting time of western yellow pines

Treesearch

James L. Jenkinson

1980-01-01

Seedlings of 27 sources of western yellow pines, selected in climates typical of the species, were raised in a nursery in the western Sierra Nevada. Seedling top and root growth capacities were periodically assessed during fall and winter, and field survivals of outplanted seedlings were evaluated in different climates with summer drought. In the nursery, four distinct...

Accelerated Growth and Initial Flowering of S2 Pinus Banksiana Selected for Precocious Flowering

Treesearch

Hyun Kang; Robert A. Cecich

1999-01-01

An accelerated growth protocol was applied in a greenhouse to hasten flowering in 13 S2 lines of jack pine (Pinus banksiana Lamb.) selected for precocious flowering. Seeds were sown on October 1. After the artificial "summer, fall, winter, and spring," seedlings were placed outdoors between June 20 and November 1. Ovulate strobili were...

Chaparral and fire

USGS Publications Warehouse

Keeley, Jon E.

2007-01-01

Large wildfires are an inevitable feature of chaparral. The moderate temperatures during winter promote growth of extensive stands of shrublands with contiguous fuels covering massive portions of the landscape. The summer-fall drought makes these fuels highly flammable over a relatively lengthy portion of the year. Because of widespread human influence, most fires today are anthropogenic; however, in wilderness areas lightning still accounts for some chaparral fires.

Drinking Water Systems, Hydrology, and Childhood Gastrointestinal Illness in Central and Northern Wisconsin

PubMed Central

Uejio, Christopher K.; Yale, Steven H.; Malecki, Kristen; Borchardt, Mark A.; Anderson, Henry A.; Patz, Jonathan A.

2014-01-01

Objectives. This study investigated if the type of drinking water source (treated municipal, untreated municipal, and private well water) modifies the effect of hydrology on childhood (aged < 5 years) gastrointestinal illness. Methods. We conducted a time series study to assess the relationship between hydrologic and weather conditions with childhood gastrointestinal illness from 1991 to 2010. The Central and Northern Wisconsin study area includes households using all 3 types of drinking water systems. Separate time series models were created for each system and half-year period (winter/spring, summer/fall). Results. More precipitation (summer/fall) systematically increased childhood gastrointestinal illness in municipalities accessing untreated water. The relative risk of contracting gastrointestinal illness was 1.4 in weeks with 3 centimeters of precipitation and 2.4 in very wet weeks with 12 centimeters of precipitation. By contrast, gastrointestinal illness in private well and treated municipal areas was not influenced by hydrologic conditions, although warmer winter temperatures slightly increased incidence. Conclusions. Our study suggests that improved drinking water protection, treatment, and delivery infrastructure may improve public health by specifically identifying municipal water systems lacking water treatment that may transmit waterborne disease. PMID:24524509

Sources and levels of ambient ocean sound near the Antarctic Peninsula.

PubMed

Dziak, Robert P; Bohnenstiehl, DelWayne R; Stafford, Kathleen M; Matsumoto, Haruyoshi; Park, Minkyu; Lee, Won Sang; Fowler, Matt J; Lau, Tai-Kwan; Haxel, Joseph H; Mellinger, David K

2015-01-01

Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region) from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapid disintegration also releases significant acoustic energy, equivalent to large-scale geophysical events. Overall ambient sound levels can be as much as ~10-20 dB higher in the open, deep ocean of the Scotia Sea compared to the relatively shallow Bransfield Strait. Noise levels become lowest during the austral winter, as sea-ice cover suppresses wind and wave noise. Ambient noise levels are highest during austral spring and summer, as surface noise, ice cracking and biological activity intensifies. Vocalizations of blue (Balaenoptera musculus) and fin (B. physalus) whales also dominate the long-term spectra records in the 15-28 and 89 Hz bands. Blue whale call energy is a maximum during austral summer-fall in the Drake Passage and Bransfield Strait when ambient noise levels are a maximum and sea-ice cover is a minimum. Fin whale vocalizations were also most common during austral summer-early fall months in both the Bransfield Strait and Scotia Sea. The hydrophone data overall do not show sustained anthropogenic sources (ships and airguns), likely due to low coastal traffic and the typically rough weather and sea conditions of the Southern Ocean.

Sources and Levels of Ambient Ocean Sound near the Antarctic Peninsula

PubMed Central

Dziak, Robert P.; Bohnenstiehl, DelWayne R.; Stafford, Kathleen M.; Matsumoto, Haruyoshi; Park, Minkyu; Lee, Won Sang; Fowler, Matt J.; Lau, Tai-Kwan; Haxel, Joseph H.; Mellinger, David K.

2015-01-01

Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region) from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapid disintegration also releases significant acoustic energy, equivalent to large-scale geophysical events. Overall ambient sound levels can be as much as ~10–20 dB higher in the open, deep ocean of the Scotia Sea compared to the relatively shallow Bransfield Strait. Noise levels become lowest during the austral winter, as sea-ice cover suppresses wind and wave noise. Ambient noise levels are highest during austral spring and summer, as surface noise, ice cracking and biological activity intensifies. Vocalizations of blue (Balaenoptera musculus) and fin (B. physalus) whales also dominate the long-term spectra records in the 15–28 and 89 Hz bands. Blue whale call energy is a maximum during austral summer-fall in the Drake Passage and Bransfield Strait when ambient noise levels are a maximum and sea-ice cover is a minimum. Fin whale vocalizations were also most common during austral summer-early fall months in both the Bransfield Strait and Scotia Sea. The hydrophone data overall do not show sustained anthropogenic sources (ships and airguns), likely due to low coastal traffic and the typically rough weather and sea conditions of the Southern Ocean. PMID:25875205

Overview of the limnology of crater lake

USGS Publications Warehouse

Larson, G.L.

1996-01-01

Crater Lake occupies the collapsed caldera of volcanic Mount Mazama in Crater Lake National Park, Oregon. It is the deepest lake (589 m) in the United States and the 7th deepest lake in the world. The water column mixes to a depth of about 200 m in winter and spring from wind energy and cooling. The deep lake is mixed in winter and early spring each year when relatively cold water near the surface sinks and exchanges positions with water in the deep basins of the lake. The lake becomes thermally stratified in summer and early fall. The metalimnion extends to a depth of about 100 m; thus most of the water column is a cold hypolimnion. Secchi disk clarity measurements typically are in the upper-20-m range to the low-30-m range in summer and early fall. Concentrations of nutrients are low, although conductivity is relatively high owing to the inflow of hydrothermal fluids. Total chlorophyll is low in concentration, but typically maximal at a depth of 120 m during periods of thermal stratification. Primary production also is low, with the maximum levels occurring between the depth of 40 and 80 m. Phytoplankton taxa are spatially segregated from each other within the water column to a depth of 200 m in summer and early fall. The same generalization applies to the Zooplankton taxa. Water level, clarity, concentrations of total chlorophyll, primary production, and abundances of zooplankton and introduced kokanee salmon exhibit long-term fluctuations. Based primarily on a recent 10-year study of the lake, the lake is considered to be pristine, except for the consequences of fish introductions. ?? 1996 by the Northwest Scientific Association. All rights reserved.

Overview of the limnology of Crater Lake

USGS Publications Warehouse

Larson, Gary L.

1996-01-01

Crater Lake occupies the collapsed caldera of volcanic Mount Mazama in Crater Lake National Park, Oregon. It is the deepest lake (589 m) in the United States and the 7th deepest lake in the world. The water column mixes to a depth of about 200 m in winter and spring from wind energy and cooling. The deep lake is mixed in winter and early spring each year when relatively cold water near the surface sinks and exchanges positions with water in the deep basins of the lake. The lake becomes thermally stratified in summer and early fall. The metalimnion extends to a depth of about 100 m; thus most of the water column is a cold hypolimnion. Secchi disk clarity measurements typically are in the upper-20-m range to the low-30-m range in summer and early fall. Concentrations of nutrients are low, although conductivity is relatively high owing to the inflow of hydrothermal fluids. Total chlorophyll is low in concentration, but typically maximal at a depth of 120 m during periods of thermal stratification. Primary production also is low, with the maximum levels occurring between the depth of 40 and 80 m. Phytoplankton taxa are spatially segregated from each other within the water column to a depth of 200 m in summer and early fall. The same generalization applies to the zooplankton taxa. Water level, clarity, concentrations of total chlorophyll, primary production, and abundances of zooplankton and introduced kokanee salmon exhibit long-term fluctuations. Based primarily on a recent 10-year study of the lake, the lake is considered to be pristine, except for the consequences of fish introductions.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luecke, C.; Wurtsbaugh, W.A.; Budy, P.

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.

Analysis of Rawinsonde Spatial Separation for Space Launch Vehicle Applications at the Eastern Range

NASA Technical Reports Server (NTRS)

Decker, Ryan K.

2017-01-01

Spatial separation of HR rawinsonde data is directly correlated with climatological tropospheric wind environment over ER. Stronger winds in the winter result in further downrange drift. Lighter winds in the summer result in the less horizontal drift during ascent. Maximum downrange distance can exceed 200 km during winter months. Data could misrepresent the environment the vehicle will experience during ascent. PRESTO uses all available data sources to produce the best representative, vertically complete atmosphere for launch vehicle DOL operations. Capability planned for use by NASA Space Launch System vehicle's first flight scheduled for Fall 2018.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harnish, Ryan A.; Green, Ethan D.; Vernon, Christopher R.

The purpose of this study was to determine the extent to which juvenile hatchery summer steelhead and wild winter steelhead overlap in space and time, to evaluate the extent of residualism among hatchery summer steelhead in the South Santiam River, and to evaluate the potential for negative ecological interactions among hatchery summer steelhead and wild winter steelhead. Because it is not possible to visually discern juvenile winter steelhead from resident rainbow trout, we treated all adipose-intact juvenile O. mykiss as one group that represented juvenile wild winter steelhead. The 2014 study objectives were to 1) estimate the proportion of hatcherymore » summer steelhead that residualized in the South Santiam River in 2014, 2) determine the extent to which hatchery and naturally produced O. mykiss overlapped in space and time in the South Santiam River, and 3) characterize the behavioral interactions between hatchery-origin juvenile summer steelhead and naturally produced O. mykiss. We used a combination of radio telemetry and direct observations (i.e., snorkeling) to determine the potential for negative interactions between hatchery summer and wild winter steelhead juveniles in the South Santiam River. Data collected from these two independent methods indicated that a significant portion of the hatchery summer steelhead released as smolts did not rapidly emigrate from the South Santiam River in 2014. Of the 164 radio-tagged steelhead that volitionally left the hatchery, only 66 (40.2%) were detected outside of the South Santiam River. Forty-four (26.8% of 164) of the radio-tagged hatchery summer steelhead successfully emigrated to Willamette Falls. Thus, the last known location of the majority of the tagged fish (98 of 164 = 59.8%) was in the South Santiam River. Thirty-three of the tagged hatchery steelhead were detected in the South Santiam River during mobile-tracking surveys. Of those, 21 were found to be alive in the South Santiam River over three months after their release, representing a residualization rate of 12.8% (21 of 164). Snorkeling revealed considerable overlap of habitat use (in space and time) by residual hatchery steelhead and naturally produced O. mykiss in the South Santiam River. Results from our study (and others) also indicated that hatchery steelhead juveniles typically dominate interactions with naturally produced O. mykiss juveniles. The overlap in space and time, combined with the competitive advantage that residual hatchery steelhead appear to have over naturally produced O. mykiss, increases the potential for negative ecological interactions that could have population-level effects on the wild winter steelhead population of the South Santiam River.« less

Effect of antecedent-hydrological conditions on rainfall triggering of debris flows in ash-fall pyroclastic mantled slopes of Campania (southern Italy)

USGS Publications Warehouse

Napolitano, E.; Fusco, F; Baum, Rex L.; Godt, Jonathan W.; De Vita, P.

2016-01-01

Mountainous areas surrounding the Campanian Plain and the Somma-Vesuvius volcano (southern Italy) are among the most risky areas of Italy due to the repeated occurrence of rainfallinduced debris flows along ash-fall pyroclastic soil-mantled slopes. In this geomorphological framework, rainfall patterns, hydrological processes taking place within multi-layered ash-fall pyroclastic deposits and soil antecedent moisture status are the principal factors to be taken into account to assess triggering rainfall conditions and the related hazard. This paper presents the outcomes of an experimental study based on integrated analyses consisting of the reconstruction of physical models of landslides, in situ hydrological monitoring, and hydrological and slope stability modeling, carried out on four representative source areas of debris flows that occurred in May 1998 in the Sarno Mountain Range. The hydrological monitoring was carried out during 2011 using nests of tensiometers and Watermark pressure head sensors and also through a rainfall and air temperature recording station. Time series of measured pressure head were used to calibrate a hydrological numerical model of the pyroclastic soil mantle for 2011, which was re-run for a 12-year period beginning in 2000, given the availability of rainfall and air temperature monitoring data. Such an approach allowed us to reconstruct the regime of pressure head at a daily time scale for a long period, which is representative of about 11 hydrologic years with different meteorological conditions. Based on this simulated time series, average winter and summer hydrological conditions were chosen to carry out hydrological and stability modeling of sample slopes and to identify Intensity- Duration rainfall thresholds by a deterministic approach. Among principal results, the opposing winter and summer antecedent pressure head (soil moisture) conditions were found to exert a significant control on intensity and duration of rainfall triggering events. Going from winter to summer conditions requires a strong increase of intensity and/or duration to induce landslides. The results identify an approach to account for different hazard conditions related to seasonality of hydrological processes inside the ash-fall pyroclastic soil mantle. Moreover, they highlight another important factor of uncertainty that potentially affects rainfall thresholds triggering shallow landslides reconstructed by empirical approaches.

Determination of season at death using dental cementum increment analysis.

PubMed

Wedel, Vicki L

2007-11-01

Dental cementum anchors teeth into their sockets via the periodontal ligament. In mammals, dental cementum is laid down in alternating opaque and translucent bands representing winter (dormant) and summer (growth) seasons. Each pair of bands represents 1 year of life. Estimates of age at death based on counting pairs of bands are highly accurate. If the timing of the transition between winter and summer bands could be identified in humans, dental cementum increment analysis could be used to specify the season at death. This pilot project attempts to determine when these transitions occur and thus provide forensic anthropologists with a technique that would refine our estimates of postmortem interval. Extracted teeth were obtained from a local oral surgeon, embedded, sectioned, ground, polished, and examined under transmitted polarized light. The outermost increment was identified and measured along with other randomly chosen like bands. A transition from translucent to opaque bands was observed in teeth extracted in early October, while teeth extracted in early April exhibited nascent translucent bands. Further, significant correlations were observed between band thickness and number of days into either season, suggesting that band width increases as either season progresses. In this blind study, extracted teeth were effectively sorted into the spring/summer or fall/winter season 99% of the time.

The Interaction Between Dynamics and Chemistry of Ozone in the Set-up Phase of the Northern Hemisphere Polar Vortex

NASA Technical Reports Server (NTRS)

Kawa, S. R.; Bevilacqua, R.; Margitan, J. J.; Douglass, A. R.; Schoeberl, M. R.; Hoppel, K.; Sen, B.; Bhartia, P. K. (Technical Monitor)

2001-01-01

The morphology and evolution of the stratospheric ozone (O3) distribution at high latitudes in the Northern Hemisphere (NH) are examined for the late summer and fall seasons of 1999. This time period sets the O3 initial condition for the SOLVE/THESEO field mission performed during winter 1999-2000. In situ and satellite data are used along with a three-dimensional model of chemistry and transport (CTM) to determine the key processes that control the distribution of O3 in the lower-to-middle stratosphere. O3 in the vortex at the beginning of the winter season is found to be nearly constant from 500 to above 800 K with a value at 3 ppmv +/- approx. 10%. Values outside the vortex are up to a factor of 2 higher and increase significantly with potential temperature. The seasonal time series of data from POAM shows that relatively low O3 mixing ratios, which characterize the vortex in late fall, are already present at high latitudes at the end of summer before the vortex circulation sets up. Analysis of the CTM output shows that the minimum O3 and increase in variance in late summer are the result of: 1) stirring of polar concentric O3 gradients by nascent wave-driven transport, and 2) an acceleration of net photochemical loss with decreasing solar illumination. The segregation of low O3 mixing ratios into the vortex as the circulation strengthens through the fall suggests a possible feedback role between O3 chemistry and the vortex formation dynamics. Trajectory calculations from O3 sample points early in the fall, however, show only a weak correlation between initial O3 mixing ratio and potential vorticity later in the season consistent with order-of-magnitude calculations for the relative importance of O3 in the fall radiative balance at high latitudes. The possible connection between O3 chemistry and the dynamics of vortex formation does suggest that these feedbacks and sensitivities need to be better understood in order to make confident predictions of the recovery of NH O3.

Seasonal migration to high latitudes results in major reproductive benefits in an insect

PubMed Central

Chapman, Jason W.; Bell, James R.; Burgin, Laura E.; Reynolds, Donald R.; Pettersson, Lars B.; Hill, Jane K.; Bonsall, Michael B.; Thomas, Jeremy A.

2012-01-01

Little is known of the population dynamics of long-range insect migrants, and it has been suggested that the annual journeys of billions of nonhardy insects to exploit temperate zones during summer represent a sink from which future generations seldom return (the “Pied Piper” effect). We combine data from entomological radars and ground-based light traps to show that annual migrations are highly adaptive in the noctuid moth Autographa gamma (silver Y), a major agricultural pest. We estimate that 10–240 million immigrants reach the United Kingdom each spring, but that summer breeding results in a fourfold increase in the abundance of the subsequent generation of adults, all of which emigrate southward in the fall. Trajectory simulations show that 80% of emigrants will reach regions suitable for winter breeding in the Mediterranean Basin, for which our population dynamics model predicts a winter carrying capacity only 20% of that of northern Europe during the summer. We conclude not only that poleward insect migrations in spring result in major population increases, but also that the persistence of such species is dependent on summer breeding in high-latitude regions, which requires a fundamental change in our understanding of insect migration. PMID:22927392

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

PubMed

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.

Trends in temperature and dew point at the summit of Mount Washington, New Hampshire, 1935-2004.

NASA Astrophysics Data System (ADS)

Grant, A. N.; Pszenny, A. A.; Fischer, E. V.

2005-05-01

Dry and wet bulb temperatures from sling psychrometer measurements taken every six hours from 1935 to 2004 at the summit of Mount Washington, located at 44 °16'N, 71 °18'W, 1914 m ASL have recently been digitized. Annual temperature has increased by 0.3°C, and annual dew point has decreased by 0.4°C over this 70-year period. Synoptic temperature has increased most in spring and winter, changing by 1.0°C and 0.5°C, respectively, while it has decreased slightly in summer and fall. Dew point has decreased in fall, summer, and winter, 0.9°C, 0.5°C, and 0.4°C respectively, and increased by 0.1°C in spring. Preliminary analysis suggests that some of the larger trends in winter and spring may be statistically significant; results of Monte Carlo simulations will be reported. Changes in dew point may be attributed to two factors. Decreasing dew points are expected if the temperature increases but the amount of water vapor present stays the same. Alternatively, lower dew points could be indicative of the presence of drier air. Other dew point climatologies of the continental United States for the second half of the century have shown mixed results, with increased dew points evident at some stations, decreased dew points at others, and no clear regional patterns.

Seed germination, phenology, and antiedematogenic activity of Peperomia pellucida (L.) H. B. K.

PubMed Central

Arrigoni-Blank, Maria de Fátima; Oliveira, Ricardo Luiz Barros; Mendes, Sandra Santos; Silva, Paulo de Albuquerque; Antoniolli, Ângelo Roberto; Vilar, Jeane Carvalho; Cavalcanti, Sócrates Cabral de Holanda; Blank, Arie Fitzgerald

2002-01-01

Background Peperomia pellucida is popularly known as coraçãozinho in the Brazilian northeast and is used in the treatment of abscesses, furuncles, and conjunctivitis. Our work aimed to determine the term of the development stages and the species cycle in the four seasons of the year (complete development, beginning of bloom, complete bloom, and seed set), verifying the plant's therapeutic profile during the four distinct development phases in order to detect differences in its potency. Pharmacological tests were performed to observe the anti-inflammatory activity. Results Phenological observations were accessed for a 12 month-period, from the Brazilian summer of 1999/2000 to fall 2000. On average the plantules' emergence occurred 15 days after seeding. All plantules grew in a similar manner up to 25 days after transplantation in all seasons. Starting on the 25th day, we observed faster growth during spring, with plants reaching a height of about 60 cm after 100 days of transplantation, unlike other seasons, in which plants reached heights of 40, 40, and 35 cm during winter, summer, and fall, respectively. The P. pellucida aqueous extract showed significant anti-inflammatory activity during phenophases 1 and 2 of winter and spring. Depending on the plant's phenophase there was variation in the potency of edema inhibition. Conclusion P. pellucida has a phenological cycle of approximately 100 days. It is recommended that the P. pellucida aqueous extract is used as an antiedematogenic only during phenophases 1 and 2 of winter and spring. PMID:12019026

Seed germination, phenology, and antiedematogenic activity of Peperomia pellucida (L.) H. B. K.

PubMed

Arrigoni-Blank, Maria de Fátima; Oliveira, Ricardo Luiz Barros; Mendes, Sandra Santos; Silva, Paulo de Albuquerque; Antoniolli, Angelo Roberto; Vilar, Jeane Carvalho; Cavalcanti, Sócrates Cabral de Holanda; Blank, Arie Fitzgerald

2002-05-09

Peperomia pellucida is popularly known as coraçãozinho in the Brazilian northeast and is used in the treatment of abscesses, furuncles, and conjunctivitis. Our work aimed to determine the term of the development stages and the species cycle in the four seasons of the year (complete development, beginning of bloom, complete bloom, and seed set), verifying the plant's therapeutic profile during the four distinct development phases in order to detect differences in its potency. Pharmacological tests were performed to observe the anti-inflammatory activity. Phenological observations were accessed for a 12 month-period, from the Brazilian summer of 1999/2000 to fall 2000. On average the plantules' emergence occurred 15 days after seeding. All plantules grew in a similar manner up to 25 days after transplantation in all seasons. Starting on the 25th day, we observed faster growth during spring, with plants reaching a height of about 60 cm after 100 days of transplantation, unlike other seasons, in which plants reached heights of 40, 40, and 35 cm during winter, summer, and fall, respectively. The P. pellucida aqueous extract showed significant anti-inflammatory activity during phenophases 1 and 2 of winter and spring. Depending on the plant's phenophase there was variation in the potency of edema inhibition. P. pellucida has a phenological cycle of approximately 100 days. It is recommended that the P. pellucida aqueous extract is used as an antiedematogenic only during phenophases 1 and 2 of winter and spring.

Growth and ion distribution is affected by irrigation with saline water in selected landscape species grown in two consecutive growing seasons: Spring - Summer and Fall – Winter

USDA-ARS?s Scientific Manuscript database

Landscape irrigation is the second largest user of reclaimed water in industrialized countries; however its high concentration of soluble salts, especially Na+ and Cl-, may induce growth reduction and leaf necrosis or bronzing in ornamental species. The present study was conducted to determine the g...

Inside English: Journal of the English Council of California Two-Year Colleges; Vol. V, Nos. 1-3, Fall 1978, Winter 1979, and Summer 1979.

ERIC Educational Resources Information Center

Bilson, Barbara, Ed.; Kurilich, Frances, Ed.

1979-01-01

Designed primarily for English faculty at two-year colleges in California, "Inside English" includes articles on instructional innovations and major curricular, administrative, and employment issues of concern to teachers in the field as well as information on the activities of the English Council of the California Two-Year Colleges (ECCTYC). The…

VCCA Journal: Journal of the Virginia Community Colleges Association; Volume 4, Numbers 1 and 2, Spring/Summer 1989 and Fall/Winter 1989.

ERIC Educational Resources Information Center

Hurst, Darrell, Ed.; Jobin, Robert, Ed.

1989-01-01

The first issue of this semi-annual journal features presentations and papers from the sixth Annual Virginia Community Colleges Association Convention held November 17-18, 1988, including the following: "Community College Mission: An Ideology Out of Balance," by Darrel Clowes and Bernard H. Levin; "The Bottom of the Blind Man's…

Demography of snowshoe hares in relation to regional climate variabilty during a 10-year population cycle in interior Alaska

Treesearch

K. Kielland; K. Olson; E. Euskirchen

2009-01-01

We monitored populations of snowshoe hares (Lepus americanus, Erxleben) in interior Alaska for 10 years from 1999 to 2008. During this period, fall densities of hares fluctuated approximately 14-fold. High population growth rates over summer were followed by large population declines over winter. Young-of-the-year hares tended to gain mass over...

Clinical relevance of about-yearly changes in blood pressure and the environment

NASA Astrophysics Data System (ADS)

Halberg, Franz; Cornélissen, Germaine; Haus, Erhard; Northrup, Gordon; Portela, Ana; Wendt, Hans; Otsuka, Kuniaki; Kumagai, Yuji; Watanabe, Yoshihiko; Zaslavskaya, Rina

1996-12-01

Changes identified by inferential statistics from summer to winter of high to low arterial blood pressures (BP) have been quantified as a large predictable about-yearly BP swing. This condition of a large annual BP amplitude (LABPA) raises concern about hypotension as well as hypertension and raises new questions regarding appropriate guidelines for diagnosis and treatment. Recommendations made in the fall on the basis of data collected in the summer may be totally inadequate in dealing with the patient's condition in the winter. In order to avoid such mistakes, it is imperative to implement a systematic surveillance of BP in the light of current chronobiological limits. Patients with a large circannual BP amplitude are particularly suited for a study of the underlying hormonal mechanisms. The longitudinal monitoring of their BP is also amenable to the study of environmental influences from near and far.

Molluscicidal action of the latex of Euphorbia splendens var. hislopii N.E.B. ("Christ's Crown") (Euphorbiaceae) against Lymnaea columella (Say, 1817) (Pulmonata: Lymnaeidae), intermediate host of Fasciola hepatica Linnaeus, 1758 (Trematode: Fasciolidae): 1- test in laboratory.

PubMed

de Vasconcellos, Mauricio Carvalho; de Amorim, Alziro

2003-06-01

The latex action of Euphorbia splendens var. hislopii (Christ's Crown) against snails Lymnaea columella, intermediate host of Fasciola hepatica, derived from irrigation ditches of the Station of Pisciculture at Universidade Federal Rural do Rio de Janeiro, was studied in the laboratory. Lab bioassays, using aqueous solutions of the latex, varying between 0.1 and 10 mg/l, have proven molluscicidal activity of the product collected on the same day the tests were performed, during the four seasons of the year, finding the following lethal concentrations (LC90): 1.51 mg/l in the spring; 0.55 mg/l in the summer; 0.74 mg/l in the fall and 0.93 mg/l in winter, after 24 h exposure of the snails, showing significant differences among the seasons of the year (ANOVA test, F = 11.01, G.L.= 3/33, p < 0.05), as well as among the concentrations (ANOVA test, F = 27.38, G.L.= 11/33, p < 0.05). In the summer, mortality reached 100% from concentration at 0.6 mg/l, the same during fall and in winter as of 1 mg/l, while in spring it only reached 100% mortality as of 2 mg/l. Mortality in the controls was low, reaching 5% in the summer and winter and 10% in the fall and spring. None of the samples died. During the assay, with an aqueous solution of the latex at a concentration of 5 mg/l, in order to check the time of duration of the product effect, in the laboratory, it was observed that the molluscicidal activity remained stable up to the 15th day after the beginning of the test with 100% mortality of L. columella, gradually losing its effect until the 23rd day, when we no longer observed animal mortality. In the control group, there was a random daily variation in mortality rate ranging 0-50% after 48 h of observation for 30 days.

Seasonal food habits of introduced blue catfish in Lake Oconee, Georgia

USGS Publications Warehouse

Jennings, Cecil A.; Mitchell, Geoffrey E.; Nelson, Chris

2018-01-01

Blue catfish (Ictalurus furcatus) are native to the Coosa River drainage in northwest Georgia but have been widely introduced outside of this range including Lake Oconee, a 7677-ha impoundment on the Oconee River in central Georgia. Blue catfish abundance and growth rates have increased dramatically since their introduction in Lake Oconee, but their food habits are unknown. Therefore, food habits of blue catfish in this impoundment were determined by examining the stomachs of 808 specimens in the reservoir’s upper and lower regions across all seasons from summer 2012 to summer 2013. Diet was summarized using the Relative Importance of specific prey by weight. In the upper region of the reservoir, Asian clams (Corbicula fluminea) were the dominant prey item during the summer (75.7%), fall (66.4%), and winter (37.6%); whereas crappie (Pomoxis spp.) was the dominant prey item in the spring (38.7%). Asian clams also were the dominant prey items in the lower region during the fall (68.4%), winter (33.9%), and spring (36.4%). Blue catfish seemed to feed opportunistically on seasonally abundant prey items in both the upper riverine and lower lacustrine portions of the reservoir. Of the many sportfishes in the reservoir, only crappie was an important prey item, and then only in the upper region during the spring. Our results do not support concerns that blue catfish are an apex predator that would decimate the sportfish assemblage in this recently colonized reservoir.

Phosphorus Availability, Phytoplankton Community Dynamics, and Taxon-Specific Phosphorus Status in the Gulf of Aqaba, Red Sea

NASA Astrophysics Data System (ADS)

Mackey, K. R.; Labiosa, R. G.; Calhoun, M.; Street, J. H.; Post, A. F.; Paytan, A.

2006-12-01

The relationships among phytoplankton taxon-specific phosphorus-status, phytoplankton community composition, and nutrient levels were assessed over three seasons in the Gulf of Aqaba, Red Sea. During summer and fall, stratified surface waters were depleted of nutrients and picophytoplankton populations comprised the majority of cells (80% and 88% respectively). In winter, surface nutrient concentrations were higher and larger phytoplankton were more abundant (63%). Cell specific alkaline phosphatase activity (APA) derived from enzyme labeled fluorescence was consistently low (less than 5%) in the picophytoplankton throughout the year, whereas larger cells expressed elevated APA during the summer and fall but less in the winter. A nutrient addition bioassay during the fall showed that, relative to control, APA was reduced by half in larger cells following addition of orthophosphate, whereas the APA of picophytoplankton remained low (less than 1%) across all treatments and the control. These results indicate that the most abundant phytoplankton are not limited by orthophosphate and only some subpopulations (particularly of larger cells) exhibit orthophosphate-limitation throughout the year. Our results indicate that orthophosphate availability influences phytoplankton ecology, correlating with shifts in phytoplankton community structure and the nutrient status of individual cells. The role of dissolved organic phosphorus as an important phosphorus source for marine phytoplankton in oligotrophic settings and the need for evaluating nutrient limitation at the taxa and/or single cell level (rather than inferring it from nutrient concentrations and ratios or bulk enzyme activity measurements) are highlighted.

Hydrology of C-3 watershed, Seney National Wildlife Refuge, Michigan

USGS Publications Warehouse

Sweat, Michael J.

2001-01-01

Proposed changes to watershed management practices near C-3 Pool at Seney National Wildlife Refuge will affect surface-water flow patterns, ground-water levels, and possibly local plant communities. Data were collected between fall 1998 and spring 2000 to document existing conditions and to assess potential changes in hydrology that might occur as a consequence of modifications to water management practices in C-3 watershed.Minimum and maximum measured inflows and outflows for the study period are presented in light of proposed management changes to C-3 watershed. Streamflows ranged from 0 to 8.61 cubic meters per second. Low or zero flow was generally measured in late summer and early fall, and highest flows were measured during spring runoff and winter rain events. Ground-water levels varied by about a half meter, with levels closest to or above the land surface during spring runoff into the early summer, and with levels generally below land surface during late fall into early winter.A series of optional management practices that could conserve and restore habitat of the C-3 watershed is described. Modifications to the existing system of a drainage ditch and control structures are examined, as are the possibilities of reconnecting streams to their historical channels and the construction of additional or larger control structures to further manage the distribution of water in the watershed. The options considered could reduce erosion, restore presettlement streamflow conditions, and modify the ground-water gradient.

Quantifying The Effects of Initial Soil Moisture On Seasonal Streamflow Forecasts In The Columbia River Basin

NASA Astrophysics Data System (ADS)

Hamlet, A. F.; Wood, A.; Lettenmaier, D. P.

The role of soil moisture storage in the hydrologic cycle is well understood at a funda- mental level. Antecedent conditions are known to have potentially significant effects on streamflow forecasts, especially for short (e.g., flood) lead times. For this reason, the U.S. Geological Survey defines its "water year" as extending from October through September, a time period selected because over most of the U.S., soil moisture is at a seasonal low at summer's end. The effects of carryover soil moisture storage in the Columbia River basin have usually been considered to be minimal when forecasts are made on a water year or seasonal basis. Our study demonstrates that the role of carry- over soil moisture storage can be important. Absent direct observations of ET and soil moisture that would permit a closing of the water balance from observations, we use a physically based hydrologic model to estimate the soil moisture state at the begin- ning of the forecast period (Oct 1). We then evaluate, in a self-consistent manner, the subsequent effects of interannual variations in fall soil moisture on streamflow during the subsequent spring and summer snowmelt season (April-September). We analyze the period from 1950-1999, and the subsequent effects to the seasonal water balance at The Dalles, OR for representative high, medium, and low water years. The effects of initial soil state in fall are remarkably persistent, with significant effects occurring in the summer of the following water year. For a representative low flow year (1992), the simulated variability of the soil moisture state in September produces a range of summer streamflows (April-September mean) equivalent to about 16 percent of the mean summer flows for all initial soil conditions, with analogous, but smaller, relative changes for medium and high flow years. Winter flows are also affected, and the rel- ative intensity of effects in winter and summer is variable, an effect that is probably attributable to the amount of soil recharge that occurs (or does not occur) in early fall in a particular water year. Issues relating to hydrologic model calibration and some applications to experimental long-lead forecasts in the Columbia basin are also dis- cussed.

Density-Dependent Oviposition by Female Aedes albopictus (Diptera: Culicidae) Spreads Eggs Among Containers During the Summer but Accumulates Them in the Fall.

PubMed

Fonseca, D M; Kaplan, L R; Heiry, R A; Strickman, D

2015-07-01

When possible, oviparous females should deposit eggs in sites that maximize the future performance of their offspring. Therefore, studies of oviposition behavior may uncover parameters important to offspring fitness. Gravid female Aedes albopictus (Skuse) were given a choice of containers with leaf infusion or plain water, either open or with a cover with a small opening, and their behavior was compared under summer (long day, higher temperature) or fall (short day, lower temperature) regimes. Open containers with leaf infusion were always preferred, but over time, summer females expanded their choices to oviposit in all containers and follow-up experiments indicated that the number of eggs laid was inversely correlated to the number of eggs present. In contrast, fall females laying diapausing eggs that do not hatch until the spring, accumulated eggs in open containers with food resulting in high egg densities. Combined, these results demonstrate a seasonal shift that suggests either high winter egg mortality or safety in numbers. It also demonstrates that female Ae. albopictus change their behavior based on cues associated with expected added risk, which varies across time and space. The wide distribution of summer eggs across container types may contribute to the fast expansion of Ae. albopictus across its invasive range, but egg accumulation in the fall may be exploited for control. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Seasonal and spatial variations in fish and macrocrustacean assemblage structure in Mad Island Marsh estuary, Texas

NASA Astrophysics Data System (ADS)

Akin, S.; Winemiller, K. O.; Gelwick, F. P.

2003-05-01

Fish and macrocrustacean assemblage structure was analyzed along an estuarine gradient at Mad Island Marsh (MIM), Matagorda Bay, TX, during March 1998-August 1999. Eight estuarine-dependent fish species accounted for 94% of the individual fishes collected, and three species accounted for 96% of macrocrustacean abundance. Consistent with evidence from other Gulf of Mexico estuarine studies, species richness and abundance were highest during late spring and summer, and lowest during winter and early spring. Sites near the bay supported the most individuals and species. Associations between fish abundance and environmental variables were examined with canonical correspondence analysis. The dominant gradient was associated with water depth and distance from the bay. The secondary gradient reflected seasonal variation and was associated with temperature, salinity, dissolved oxygen, and vegetation cover. At the scales examined, estuarine biota responded to seasonal variation more than spatial variation. Estuarine-dependent species dominated the fauna and were common throughout the open waters of the shallow lake during winter-early spring when water temperature and salinity were low and dissolved oxygen high. During summer-early fall, sub-optimal environmental conditions (high temperature, low DO) in upper reaches accounted for strong spatial variation in assemblage composition. Small estuarine-resident fishes and the blue crab ( Callinectes sapidus) were common in warm, shallow, vegetated inland sites during summer-fall. Estuarine-dependent species were common at deeper, more saline locations near the bay during this period. During summer, freshwater species, such as gizzard shad ( Dorosoma cepedianum) and gars ( Lepisosteus spp.), were positively associated with water depth and proximity to the bay. The distribution and abundance of fishes in MIM appear to result from the combined effects of endogenous, seasonal patterns of reproduction and migration operating on large spatial scales, and species-specific response to local environmental variation.

Sources and levels of ambient ocean sound near the antarctic peninsula

DOE PAGES

Dziak, Robert P.; Bohnenstiehl, DelWayne R.; Stafford, Kathleen M.; ...

2015-04-14

Arrays of hydrophones were deployed within the Bransfield Strait and Scotia Sea (Antarctic Peninsula region) from 2005 to 2009 to record ambient ocean sound at frequencies of up to 125 and 500 Hz. Icequakes, which are broadband, short duration signals derived from fracturing of large free-floating icebergs, are a prominent feature of the ocean soundscape. Icequake activity peaks during austral summer and is minimum during winter, likely following freeze-thaw cycles. Iceberg grounding and rapid disintegration also releases significant acoustic energy, equivalent to large-scale geophysical events. Overall ambient sound levels can be as much as ~10–20 dB higher in the open,more » deep ocean of the Scotia Sea compared to the relatively shallow Bransfield Strait. Noise levels become lowest during the austral winter, as sea-ice cover suppresses wind and wave noise. Ambient noise levels are highest during austral spring and summer, as surface noise, ice cracking and biological activity intensifies. Vocalizations of blue ( Balaenoptera musculus) and fin ( B. physalus) whales also dominate the long-term spectra records in the 15–28 and 89 Hz bands. Blue whale call energy is a maximum during austral summer-fall in the Drake Passage and Bransfield Strait when ambient noise levels are a maximum and sea-ice cover is a minimum. Fin whale vocalizations were also most common during austral summer-early fall months in both the Bransfield Strait and Scotia Sea. The hydrophone data overall do not show sustained anthropogenic sources (ships and airguns), likely due to low coastal traffic and the typically rough weather and sea conditions of the Southern Ocean.« less

Late summer and fall use of stream margins by young-of year brown trout in a high-elevation stream

USGS Publications Warehouse

La Voie, W. J.; Hubert, W.A.

1997-01-01

We determined the relative abundance of young-of-year (YOY) brown trout (Salmo trutta) from late summer to fall during day and night in stream margin habitats of Douglas Creek, Wyoming. No significant differences in relative abundance were observed from August 14 through October 26. Few YOY brown trout were observed during the day over the entire sampling period, but significantly greater numbers were seen at night. Within stream margins, YOY brown trout of 36-75 mm total length primarily resided in concealment cover among interstices of cobbie during the day and emerged at night. Because no significant change in relative abundance was observed throughout the study period, we conclude that a shift to winter habitat did not occur up until three days prior to ice formation when the diurnal range in water temperature was 2.5-7.5??C.

Seasonal food use by white-tailed deer at Valley Forge National Historical Park, Pennsylvania, USA

NASA Astrophysics Data System (ADS)

Cypher, Brian L.; Yahner, Richard H.; Cypher, Ellen A.

1988-03-01

Food habits of white-tailed deer ( Odocoileus virginianus) were examined from January to November 1984 via fecal-pellet analysis at Valley Forge National Historical Park (VFNHP), which represents an “island” habitat for deer surrounded by extensive urbanization, in southeastern Pennsylvania. In addition, use of fields by deer was compared to food habits. Herbaceous vegetation (forbs, leaves of woody plants, and conifer needles) was the predominant food type in all seasons except fall. Acorns and graminoids (grasses and sedges) were important food resources in fall and spring, respectively. Use of woody browse (twigs) was similar among seasons. Field use was relatively high during fall, winter without snow cover (<20 cm), and spring when food resources in fields were readily available. In contrast, use of fields was lowest in summer when preferred woodland foods were available and in winter with snow cover when food in fields was not readily accessible. Patterns of food-type use by deer at VFNHP indicate the year-round importance of nonwoody foods and field habitats to deer populations on public lands such as national parks in the northeastern United States.

ARC-1991-AC91-0121-1

NASA Image and Video Library

1991-03-01

This (Sandpiper like) bird, as well as many other species keep watch over Moffett Field wetlands. The shorebird in this picture is a greater yellowlegs (Tinga melanoleuca) which is a common bird found in our coastal salt marsh and tidal zones in winter months. Generally, they summer/breed up north in Canada and Alaska and then migrate in the fall to winter along the west coast of the U.S. and Mexico. Known for their loud call of a slightly descending series of three or more tew notes. Diet consists of small fish, insects, snails, worms, and tadpoles. used in Ames 60 yr. History NASA SP-2000-4314

Body temperature null distributions in reptiles with nonzero heat capacity: seasonal thermoregulation in the American alligator (Alligator mississippiensis).

PubMed

Seebacher, Frank; Elsey, Ruth M; Trosclair, Phillip L

2003-01-01

Regulation of body temperature may increase fitness of animals by ensuring that biochemical and physiological processes proceed at an optimal rate. The validity of current methods of testing whether or not thermoregulation in reptiles occurs is often limited to very small species that have near zero heat capacity. The aim of this study was to develop a method that allows estimation of body temperature null distributions of large reptiles and to investigate seasonal thermoregulation in the American alligator (Alligator mississippiensis). Continuous body temperature records of wild alligators were obtained from implanted dataloggers in winter (n=7, mass range: 1.6-53.6 kg) and summer (n=7, mass range: 1.9-54.5 kg). Body temperature null distributions were calculated by randomising behavioural postures, thereby randomly altering relative animal surface areas exposed to different avenues of heat transfer. Core body temperatures were predicted by calculations of transient heat transfer by conduction and blood flow. Alligator body temperatures follow regular oscillations during the day. Occasionally, body temperature steadied during the day to fall within a relatively narrow range. Rather than indicating shuttling thermoregulation, however, this pattern could be predicted from random movements. Average daily body temperature increases with body mass in winter but not in summer. Daily amplitudes of body temperature decrease with increasing body mass in summer but not in winter. These patterns result from differential exposure to heat transfer mechanisms at different seasons. In summer, alligators are significantly cooler than predictions for a randomly moving animal, and the reverse is the case in winter. Theoretical predictions show, however, that alligators can be warmer in winter if they maximised their sun exposure. We concluded that alligators may not rely exclusively on regulation of body temperature but that they may also acclimatise biochemically to seasonally changing environmental conditions.

Seasonality of fertility measured by physical activity traits in Holstein cows.

PubMed

Ismael, Ahmed; Strandberg, Erling; Berglund, Britt; Fogh, Anders; Løvendahl, Peter

2016-04-01

Seasonality of female fertility traits, including the interval from calving to first high activity (CFHA), duration of high activity episode (DHA), and strength of high activity episode (SHA) of first estrus, were studied. The physical activity traits were derived from electronic activity tags for 20,794 Holstein cows in 135 commercial Holstein herds in Denmark. Data were categorized in 3 ways: (1) into 4 seasons of calving: winter (January-March), spring (April-June), summer (July-September), and fall (October-December); (2) into 2 seasons: a cold season (October-March) and a warm season (April-September); and (3) into an increasing light season (IL; January-June), where daylight hours gradually increased, and a decreasing light season (DL; July-December), where daylight hours gradually decreased. At the phenotypic level, least squares means of CFHA were highest at 55d for cows calving in December and lowest at 31d for cows calving in September. The highest least squares means of DHA and SHA were recorded for cows calving in November and lowest for cows calving in May and June. Genetic parameters for all traits were estimated using average information-REML in a bivariate animal model that treated the same trait in different calving seasons as different traits. Heritability estimates for CFHA were highest for the winter season (0.13) and low for the other seasons (0.03-0.04), whereas heritability estimates for DHA and SHA were lowest for winter and highest for fall. Heritability estimates for CFHA for the cold season (0.17) was higher than that for the warm season (0.10). Heritability estimates of CFHA for the IL season (0.12) was higher than for the DL season (0.07), but the opposite pattern was found for DHA and SHA. Genetic correlations (rA) of CFHA between winter and summer (rA=0.34 ± 0.27), and winter and fall (rA=0.65 ± 0.20) were significantly lower than unity. The corresponding correlations of DHA and SHA between seasons were all close to unity, except for the correlation of SHA between winter and fall (rA=0.36 ± 0.34). When the year was split into only 2 seasons, the genetic correlation of CFHA between cold and warm seasons was only moderate (rA=0.46 ± 0.15) but was slightly stronger between IL and DL seasons (rA=0.63 ± 0.16); both significantly deviated from unity. These results indicate the existence of a genotype by environment interaction for CFHA regardless of calving season classification. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Sensitivity of intermittent streams to climate variations in the United States

NASA Astrophysics Data System (ADS)

Eng, K.

2015-12-01

There is growing interest in the effects of climate change on streamflows because of the potential negative effects on aquatic biota and water supplies. Previous studies of climate controls on flows have primarily focused on perennial streams, and few studies have examined the effect of climate variability on intermittent streams. Our objectives in this study were to (1) identify regions showing similar patterns of intermittency, and (2) evaluate the sensitivity of intermittent streams to historical variability in climate in the United States. This study was carried out at 265 intermittent streams by evaluating: (1) correlations among time series of flow metrics (number of zero-flow events, the average of the central 50% and largest 10% of flows) with precipitation (magnitudes, durations and intensity) and temperature, and (2) decadal changes in the seasonality and long-term trends of these flow metrics. Results identified five distinct seasonal patterns of flow intermittency: fall, fall-to-winter, non-seasonal, summer, and summer-to-winter intermittent streams. In addition, strong associations between the low-flow metrics and historical climate variability were found. However, the lack of trends in historical variations in precipitation results in no significant seasonal shifts or decade-to-decade trends in the low-flow metrics over the period of record (1950 to 2013).

Field note: comparative efficacy of a woody evapotranspiration landfill cover following the removal of aboveground biomass.

PubMed

Schnabel, William; Munk, Jens; Byrd, Amanda

2015-01-01

Woody vegetation cultivated for moisture management on evapotranspiration (ET) landfill covers could potentially serve a secondary function as a biomass crop. However, research is required to evaluate the extent to which trees could be harvested from ET covers without significantly impacting their moisture management function. This study investigated the drainage through a six-year-old, primarily poplar/cottonwood ET test cover for a period of one year following the harvest of all woody biomass exceeding a height of 30 cm above ground surface. Results were compared to previously reported drainage observed during the years leading up to the coppice event. In the first year following coppice, the ET cover was found to be 93% effective at redirecting moisture during the spring/summer season, and 95% effective during the subsequent fall/winter season. This was slightly lower than the 95% and 100% efficacy observed in the spring/summer and fall/winter seasons, respectively, during the final measured year prior to coppice. However, the post-coppice efficacy was higher than the efficacy observed during the first three years following establishment of the cover. While additional longer-term studies are recommended, this project demonstrated that woody ET covers could potentially produce harvestable biomass while still effectively managing aerial moisture.

Seasonal variations in the NO2 artifact from chemiluminescence measurements with a molybdenum converter at a suburban site in Korea (downwind of the Asian continental outflow) during 2015-2016

NASA Astrophysics Data System (ADS)

Jung, Jinsang; Lee, JaeYong; Kim, ByungMoon; Oh, SangHyub

2017-09-01

This paper investigates the NO2 artifact associated with the chemiluminescence measurement technique that uses a molybdenum converter by applying the same technique but with a photolytic converter at a site downwind of the Asian continental outflow (Daejeon, Korea). The NO2 to NO conversion efficiencies of the molybdenum and photolytic converters were found to be 100% and 95%, respectively, at an ambient level of NO2 (<100 ppbv). Two NO2 monitors equipped with molybdenum and photolytic converters were deployed for ambient NO2 measurements in Daejeon, Korea between the fall of 2015 and the summer of 2016. It was found that the monitor equipped with the molybdenum converter overestimated NO2 levels by 20.4 ± 14.7% when compared with the actual NO2 level in the Daejeon atmosphere over the entire measurement period. This NO2 artifact (ΔNO2), defined as the difference between molybdenum NO2 and photolytic NO2 values, correlated well with the PM2.5 mass concentration during the fall and winter seasons. Based on these findings, this study develops a simple correction model for ΔNO2 using the PM2.5 mass concentration during the fall and winter seasons. The model-corrected NO2 concentration correlated well with the actual NO2 values with a slope of approximately 1.0 and R2 value of 0.98 during the fall and winter seasons.

Old Growth Conifer Watersheds in the Western Cascades, Oregon: Sentinels of Climate Change

NASA Astrophysics Data System (ADS)

Miles, K. M.

2011-12-01

In the Pacific Northwest, where the majority of precipitation falls during the winter, mountain snowpacks provide an important source of streamflow during the dry summer months when water demands are frequently highest. Increasing temperatures associated with climate change are expected to result in a decline in winter snowpacks in western North America, earlier snowmelt, and subsequently a shift in the timing of streamflows, with an increasing fraction of streamflows occurring earlier in the water year and drier conditions during the summer. Long-term records from headwater watersheds in old growth conifer forest at the H. J. Andrews Experimental Forest (HJ Andrews), Oregon, provide the opportunity to examine changes in climate, vegetation, and streamflow. Continuous streamflow records have been collected since 1953, 1964, and 1969 from three small (8.5-60 ha) watersheds (WS2, WS8, and WS9). Over the 40- to 50-year period of study, late winter to early summer monthly average minimum temperatures have increased by 1-2°C, and spring snow water equivalent at a nearby Snotel site has declined, but monthly precipitation has remained unchanged. Spring runoff ratios have declined in by amounts equivalent to 0.59-2.45 mm day-1 at WS2, WS8, and WS9, which are comparable to estimated rates of stand-level transpiration from trees in these watersheds. However, winter runoff ratios have not changed significantly at either WS2 or WS9, and have actually decreased at WS8 by 2.43 mm day-1 over the period of record. Furthermore, summer runoff ratios have not changed significantly at either WS8 or WS9, and have increased at WS2 by 0.34 mm day-1 over the period of record. These findings suggest that warming temperatures have resulted in a reduction in spring snowpacks and an earlier onset of evapotranspiration in the spring when soil moisture is abundant, but physiological responses of these conifer forests to water stress and water surplus may mitigate or exceed the expression of a climate warming effect on winter or summer streamflow.

Improved simulation of Antarctic sea ice due to the radiative effects of falling snow

NASA Astrophysics Data System (ADS)

Li, J.-L. F.; Richardson, Mark; Hong, Yulan; Lee, Wei-Liang; Wang, Yi-Hui; Yu, Jia-Yuh; Fetzer, Eric; Stephens, Graeme; Liu, Yinghui

2017-08-01

Southern Ocean sea-ice cover exerts critical control on local albedo and Antarctic precipitation, but simulated Antarctic sea-ice concentration commonly disagrees with observations. Here we show that the radiative effects of precipitating ice (falling snow) contribute substantially to this discrepancy. Many models exclude these radiative effects, so they underestimate both shortwave albedo and downward longwave radiation. Using two simulations with the climate model CESM1, we show that including falling-snow radiative effects improves the simulations relative to cloud properties from CloudSat-CALIPSO, radiation from CERES-EBAF and sea-ice concentration from passive microwave sensors. From 50-70°S, the simulated sea-ice-area bias is reduced by 2.12 × 106 km2 (55%) in winter and by 1.17 × 106 km2 (39%) in summer, mainly because increased wintertime longwave heating restricts sea-ice growth and so reduces summer albedo. Improved Antarctic sea-ice simulations will increase confidence in projected Antarctic sea level contributions and changes in global warming driven by long-term changes in Southern Ocean feedbacks.

Elk and deer diets in old-growth forests in western Washington

USGS Publications Warehouse

Leslie, David M.; Starkey, Edward E.; Vavra, Martin

1984-01-01

Dietary quality and overlap of sympatric Roosevelt elk (Cervus elaphus roosevelti) and Columbian black-tailed deer (Odocoileus hemionus columbianus) were investigated in old-growth forests of the Hoh Valley, Olympic National Park, Washington. Diets of both cervids were comprised mainly of common old-growth flora, particularly in winter. High dietary overlap suggested competitive interactions for food, especially in winter when forage resources were least available. Predominant forages in fall and winter diets seemed to afford little opportunity for cervids to select different plant parts. Crude protein (CP), in vitro dry matter digestibility (IVDMD), and phosphorus (P) in important forages varied with phenology, but seasonal trends were more pronounced for shrubs and grasses than forbs and trees. CP, IVDMD, and P in cervid diets also varied seasonally and usually in the following ascending order: winter, fall, summer, spring. CP and P appeared to be adequate in diets, but low IVDMD suggested that digestible energy was limited. Few significant differences in seasonal dietary qualities were demonstrated between elk and deer. The collective cervid population (and its habitat) in the Hoh Valley is unmanaged and probably at equilibrium with its food resource, or at ecological carrying capacity. Results are discussed in light of herbivore--habitat interactions at equilibrium densities.

Stress-related hormonal alterations, growth and pelleted starter intake in pre-weaning Holstein calves in response to thermal stress.

PubMed

López, E; Mellado, M; Martínez, A M; Véliz, F G; García, J E; de Santiago, A; Carrillo, E

2018-04-01

This study aimed to investigate the effect of heat stress and month of birth on growth performance, pelleted starter intake, and stress-related hormones in Holstein calves. Birth weight and growth records, representing 4735 Holstein calves from a large commercial dairy herd in northern Mexico (25° N; 22.3 °C mean annual temperature) from 2013 to 2015, were analyzed. Temperature-humidity index (THI) at calving, season of birth, and month of birth were the independent variables, whereas growth traits were the dependent variables. Increased THI at birth from < 65 to > 85 units was associated with a decrease in birth weight from 39.3 to 38.7 kg. Calves subjected to high THI (> 75 units) at calving showed lesser (P < 0.01) pre-weaning gains (405 ± 97 g/calf/day), whereas those calves born with THI < 70 units presented the highest gains (466 ± 112 g/calf/day). Birth during the fall months reduced (P < 0.01) weaning weight by about 5 kg compared with winter months. Also, the pre-weaning average daily gain for calves born in the fall was about 70 g less (P < 0.01) than calves delivered in winter months. Plasma triiodothyronine and tetraiodothyronine levels were lower (1.02 ± 0.21 and 48 ± 7.9 ng/mL, respectively; P < 0.01) in summer and highest in winter (1.64 ± 0.48 and 66 ± 11 ng/mL, respectively). Mean plasma cortisol concentration was higher in heat-stressed calves born in summer (59 ± 40 ng/mL) than calves born in winter (20 ± 28 ng/mL). Pelleted starter intake 1 week before weaning was lowest (P < 0.01) in the fall (0.82 ± 0.26 kg/calf/day; mean ± SD) and highest in spring (1.26 ± 0.43 kg/calf/day). It was concluded that in this particular environment, heat stress affects birth weight and growth rate of Holstein calves. Thus, environmental management of the newborn calf during hot spring and summer months is warranted to optimize pelleted starter intake and calf growth rates.

Wave Energetics of the Atmosphere of Mars

NASA Astrophysics Data System (ADS)

Battalio, Joseph Michael

A comprehensive assessment of the energetics of transient waves is presented for the atmosphere of Mars using the Mars Analysis Correction Data Assimilation (MACDA) dataset (v1.0) and the eddy kinetic energy equation. Each hemisphere is divided into four representative periods covering the summer and winter solstices, a late fall period, and an early spring period for each of the three Mars years available. Northern hemisphere fall and spring eddy energetics is similar with some inter-annual and inter-seasonal variability, but winter eddy kinetic energy and its transport are strongly reduced in intensity as a result of the winter solstitial pause in wave activity. Barotropic energy conversion acts as a sink of eddy kinetic energy throughout each year with little reduction in amplitude during the solstitial pause. Baroclinic energy conversion acts as a source in fall and spring but disappears during the winter period as a result of the stabilized vertical temperature profile around winter solstice. Traveling waves are typically triggered by geopotential flux convergence. Individual waves decay through a combination of barotropic conversion of the kinetic energy from the waves to the mean flow, geopotential flux divergence, and dissipation. The southern hemisphere energetics is similar to the northern hemisphere in timing, but wave energetics is much weaker as a result of the high and zonally asymmetric topography. The effect of dust on baroclinic instability is examined by comparing a year with a global-scale dust storm (GDS) to two years without a GDS. In the GDS year, waves develop a mixed baroclinic/barotropic growth phase before decaying barotropically. Though the total amount of eddy kinetic energy generated by baroclinic energy conversion is lower during the GDS year, the maximum eddy intensity is not diminished. Instead, the number of intense eddies is reduced by about 50%.

Why rainfall response to El Niño over Maritime Continent is weaker and non-uniform in boreal winter than in boreal summer

NASA Astrophysics Data System (ADS)

Jiang, Leishan; Li, Tim

2017-11-01

Why rainfall response to El Niño is uniform and stronger over the Maritime Continent (MC) during El Niño developing summer and fall but is weaker and non-uniform during El Niño mature winter is investigated through the diagnosis of anomalous large-scale circulation patterns and a local moisture budget analysis. It is found that when anomalous Walker cells across the equatorial Pacific and Indian Ocean are strengthened toward El Niño mature winter, a low-level ascending motion anomaly starts to develop over western MC in northern fall due to topographic lifting (near Sumatra) and anomalous wind convergence (near west Kalimantan). Easterly anomalies, as a part of an anomalous anticyclone in South China Sea (SCS) that is developed during El Niño and a part of the south-easterly from Java Sea associated with anomalous Walker Circulation, bump into the mountain ridge of Sumatra and induce ascending motion anomalies near Sumatra. Meanwhile, the anomalous north-easterly in the southern flank of the anomalous anticyclone over SCS and south-easterly over Java Sea converge into west Kalimantan, leading to ascending motion there. The anomalous ascending motion tend to advect mean moisture upward to moisten lower troposphere in situ. This low-level moistening eventually sets up a convectively unstable stratification and induces a positive precipitation anomaly in the western MC. How the mechanism discussed here is relevant to previous hypotheses and how processes during El Niño might differ during La Niña are discussed.

Seasonal analysis of the short-term effects of air pollution on daily mortality in Northeast Asia.

PubMed

Kim, Satbyul Estella; Honda, Yasushi; Hashizume, Masahiro; Kan, Haidong; Lim, Youn-Hee; Lee, Hyewon; Kim, Clara Tammy; Yi, Seung-Muk; Kim, Ho

2017-01-15

The constituents and concentrations of pollutants, individual exposures, and biologic responses to air pollution may vary by season and meteorological conditions. However, evidence regarding seasonality of the acute effects of air pollution on mortality is limited and inconsistent. Herein, we examined seasonal patterns in the short-term associations of particulate matter (PM) smaller than 10μm (PM 10 ) with daily mortality in 29 cities of three northeast Asian countries. Stratified time-series models were used to determine whether season altered the effect of PM 10 on mortality. This effect was first quantified within each season and at each location using a time-series model, after which city-specific estimates were pooled using a hierarchical Bayesian model. In all data sets, 3,675,348 non-accidental deaths were registered from 1993 to 2009. In Japan, a 10μg/m 3 increase in PM 10 was significantly associated with increases in non-accidental mortality of 0.44% (95% confidence interval [CI]: 0.03%, 0.8%) in spring and 0.42% (0.02%, 0.82%) in fall. In South Korea, a 10μg/m 3 increase in PM 10 was significantly associated with increases in non-accidental mortality of 0.51% (0.01%, 1.01%) in summer and 0.45% (0.03%, 0.87%) in fall, in cardiovascular disease mortality of 0.96% (0.29%, 1.63%) in fall, and in respiratory disease mortality of 1.57% (0.40%, 2.75%) in fall. In China, a 10μg/m 3 increase in PM 10 was associated with increases in non-accidental mortality of 0.33% (0.01%, 0.66%) in summer and 0.41% (0.09%, 0.73%) in winter, in cardiovascular disease mortality of 0.41% (0.08%, 0.74%) in spring and 0.33% (0.02%, 0.64%) in winter, and in respiratory diseases mortality of 0.78% (0.27%, 1.30%) in winter. Our analyses suggest that the acute effect of particulate air pollution could vary seasonally and geographically. Copyright © 2016 Elsevier B.V. All rights reserved.

The Impact of Emission and Climate Change on Ozone in the United States under Representative Concentration Pathways (RCPs)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Yang; Fu, Joshua S.; Drake, John B.

Dynamical downscaling was applied in this study to link the global climate-chemistry model Community Atmosphere Model (CAM-Chem) with the regional models: Weather Research and Forecasting (WRF) Model and Community Multi-scale Air Quality (CMAQ). Two Representative Concentration Pathway (RCP) scenarios (RCP 4.5 and RCP 8.5) were used to evaluate the climate impact on ozone concentrations in 2050s. Ozone concentrations in the lower-mid troposphere (surface to ~300 hPa), from mid- to high latitudes in the Northern Hemisphere (NH), show decreasing trends in RCP 4.5 between 2000s and 2050s, with the largest decrease of 4-10 ppbv occurring in the summer and the fall;more » and increasing trends (2-12 ppbv) in RCP 8.5 resulting from the increased methane emissions. In RCP 8.5, methane emissions increase by ~60% by the end of 2050s, accounting for more than 90% of ozone increases in summer and fall, and 60-80% in spring and winter. Under the RCP 4.5 scenario, in the summer when photochemical reactions are the most active, the large ozone precursor emissions reduction leads to the greatest decrease of downscaled surface ozone concentrations, ranging from 6 to 10 ppbv. However, a few major cities show ozone increases of 3 to 7 ppbv due to weakened NO titration. Under the RCP 8.5 scenario, in winter, downscaled ozone concentrations increase across nearly the entire continental US in winter, ranging from 3 to 10 ppbv due to increased methane emissions and enhanced stratosphere-troposphere exchange (STE). More intense heat waves are projected to occur by the end of 2050s in RCP 8.5, leading to more than 8 ppbv of the maximum daily 8-hour daily average (MDA8) ozone during the heat wave days than other days; this indicates the dramatic impact heat waves exert on high frequency ozone events.« less

Variation in spring migration routes and breeding distribution of northern pintails Anas acuta that winter in Japan

USGS Publications Warehouse

Hupp, Jerry W.; Yamaguchi, Noriyuki; Flint, Paul L.; Pearce, John M.; Tokita, Ken-ichi; Shimada, Tetsuo; Ramey, Andrew M.; Kharitonov, Sergei; Higuchi, Hiroyoshi

2011-01-01

In North America, spring migration routes and breeding distribution of northern pintails Anas acuta vary because some individuals opportunistically nest at mid-latitudes in years when ephemeral prairie wetlands are available, whereas others regularly nest in arctic and sub-arctic regions where wetland abundance is more constant. Less was known about migration routes and breeding distribution of pintails in East Asia. From 2007–2009 we marked 198 pintails on their wintering areas in Japan with satellite transmitters to: 1) document spring migration routes and summer distribution, 2) evaluate migratory connections and breeding season sympatry with North American pintails, and 3) determine if pintails used the same migration routes in fall as in spring. Most pintails (67%) migrated to the Kamchatka or Chukotka peninsulas in eastern Russia either directly from Japan or via Sakhalin Island, Russia. Remaining pintails primarily migrated to the Magadan region or Kolyma River Basin in eastern Russia via Sakhalin Island. The Chukotka Peninsula was the most common summer destination, with highest densities in the Anadyr Lowlands; a region also used by pintails that migrate from North America. One pintail migrated to St. Lawrence Island, Alaska, in spring and another briefly migrated to the western coast of Alaska in fall. Autumn migration routes generally mirrored spring migration although most pintails bypassed Sakhalin Island in fall. Compared to North American pintails, pintails that winter in Japan exhibited less variation in migration routes and breeding distribution, and nested at higher latitudes. In the Russian Far East there is no region with habitats comparable in extent to the ephemeral mid-latitude wetlands of North America. Consequently, East Asian pintails mainly nest in arctic and sub-arctic regions where annual consistency in wetlands promotes constancy in migration routes and breeding distribution. Breeding season sympatry between pintails from different continents results more from North American pintails migrating to eastern Russia than from Japanese pintails migrating to North America.

Atmospheric Rivers and Their Role in Extreme Precipitation in the Midwest U.S.

DTIC Science & Technology

2013-03-01

located in the warm sector of extratropical cyclones (warm conveyor belt) and can be characterized by strong winds (low level jet) and large water...the associated synoptic-scale extratropical cyclone and subsequent frontal processes of each planetary wave, resulting in narrow regions of moisture...normal falls during AR storms during the winter on the West Coast. During the summer, precipitation enhancements were not as significant (mostly due

ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - PHYSICAL REMOVAL OF PARTICULATE CONTAMINANTS IN DRINKING WATER, AQUASOURCE M1A35 ULTRAFILTRATION MEMBRANE SYSTEM AT AQUA2000 RESEARCH CENTER - NSF 00/03/EPADW395

EPA Science Inventory

Verification testing of the Aquasource UF unit ws conducted over two test periods at the Aqua2000 Research Center in San Diego, CA. The first test period, from 3/5 - 4/19/99, represented winter/spring conditons. The second test period, from 8/25 - 9/28/99, represented summer/fall...

Seasonal Variability in Vadose zone biodegradation at a crude oil pipeline rupture site

USGS Publications Warehouse

Sihota, Natasha J.; Trost, Jared J.; Bekins, Barbara; Berg, Andrew M.; Delin, Geoffrey N.; Mason, Brent E.; Warren, Ean; Mayer, K. Ulrich

2016-01-01

Understanding seasonal changes in natural attenuation processes is critical for evaluating source-zone longevity and informing management decisions. The seasonal variations of natural attenuation were investigated through measurements of surficial CO2 effluxes, shallow soil CO2 radiocarbon contents, subsurface gas concentrations, soil temperature, and volumetric water contents during a 2-yr period. Surficial CO2 effluxes varied seasonally, with peak values of total soil respiration (TSR) occurring in the late spring and summer. Efflux and radiocarbon data indicated that the fractional contributions of natural soil respiration (NSR) and contaminant soil respiration (CSR) to TSR varied seasonally. The NSR dominated in the spring and summer, and CSR dominated in the fall and winter. Subsurface gas concentrations also varied seasonally, with peak values of CO2 and CH4 occurring in the fall and winter. Vadose zone temperatures and subsurface CO2 concentrations revealed a correlation between contaminant respiration and temperature. A time lag of 5 to 7 mo between peak subsurface CO2 concentrations and peak surface efflux is consistent with travel-time estimates for subsurface gas migration. Periods of frozen soils coincided with depressed surface CO2 effluxes and elevated CO2 concentrations, pointing to the temporary presence of an ice layer that inhibited gas transport. Quantitative reactive transport simulations demonstrated aspects of the conceptual model developed from field measurements. Overall, results indicated that source-zone natural attenuation (SZNA) rates and gas transport processes varied seasonally and that the average annual SZNA rate estimated from periodic surface efflux measurements is 60% lower than rates determined from measurements during the summer.

Modeling seasonal migration of fall armyworm moths

NASA Astrophysics Data System (ADS)

Westbrook, J. K.; Nagoshi, R. N.; Meagher, R. L.; Fleischer, S. J.; Jairam, S.

2016-02-01

Fall armyworm, Spodoptera frugiperda (J.E. Smith), is a highly mobile insect pest of a wide range of host crops. However, this pest of tropical origin cannot survive extended periods of freezing temperature but must migrate northward each spring if it is to re-infest cropping areas in temperate regions. The northward limit of the winter-breeding region for North America extends to southern regions of Texas and Florida, but infestations are regularly reported as far north as Québec and Ontario provinces in Canada by the end of summer. Recent genetic analyses have characterized migratory pathways from these winter-breeding regions, but knowledge is lacking on the atmosphere's role in influencing the timing, distance, and direction of migratory flights. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate migratory flight of fall armyworm moths from distinct winter-breeding source areas. Model simulations identified regions of dominant immigration from the Florida and Texas source areas and overlapping immigrant populations in the Alabama-Georgia and Pennsylvania-Mid-Atlantic regions. This simulated migratory pattern corroborates a previous migratory map based on the distribution of fall armyworm haplotype profiles. We found a significant regression between the simulated first week of moth immigration and first week of moth capture (for locations which captured ≥10 moths), which on average indicated that the model simulated first immigration 2 weeks before first captures in pheromone traps. The results contribute to knowledge of fall armyworm population ecology on a continental scale and will aid in the prediction and interpretation of inter-annual variability of insect migration patterns including those in response to climatic change and adoption rates of transgenic cultivars.

Seasonality of the Mindanao Current/Undercurrent System

NASA Astrophysics Data System (ADS)

Ren, Qiuping; Li, Yuanlong; Wang, Fan; Song, Lina; Liu, Chuanyu; Zhai, Fangguo

2018-02-01

Seasonality of the Mindanao Current (MC)/Undercurrent (MUC) system is investigated using moored acoustic Doppler current profiler (ADCP) measurements off Mindanao (8°N, 127.05°E) and ocean model simulations. The mooring observation during December 2010 to August 2014 revealed that the surface-layer MC between 50-150 m is dominated by annual-period variation and tends to be stronger in spring (boreal) and weaker in fall. Prominent semiannual variations were detected below 150 m. The lower MC between 150 and 400 m is stronger in spring and fall and weaker in summer and winter, while the northward MUC below 400 m emerges in summer and winter and disappears in spring and fall. In-phase and out-of-phase current anomalies above and below 150 m were observed alternatively. These variations are faithfully reproduced by an eddy-resolving ocean model simulation (OFES). Further analysis demonstrates that seasonal variation of the MC is a component of large-scale upper-ocean circulation gyre, while current variations in the MUC layer are confined near the western boundary and featured by shorter-scale (200-400 km) structures. Most of the MC variations and approximately half of the MUC variations can be explained by the first and second baroclinic modes and caused by local wind forcing of the western Pacific. Semiannual surface wind variability and superimposition of the two baroclinic modes jointly give rise to the enhanced subsurface semiannual variations. The pronounced mesoscale eddy variability in the MUC layer may also contribute to the seasonality of the MUC through eddy-current interaction.

Survival of Columbian white-tailed deer in western Oregon

USGS Publications Warehouse

Ricca, Mark A.; Anthony, Robert G.; Jackson, Dewaine H.; Wolfe, Scott A.

2002-01-01

Columbian white-tailed deer (Odocoileus virginianus leucurus; CWTD) are an endangered subspecies on which little demographic information exists. We determined survival rates and causes of mortality for 64 radiocol- lared adults from 1996 to 1998, and for 63 radiocollared neonatal fawns during the summer and fall months of 1996-2001 in Douglas County, Oregon, USA. Annual adult survival rates averaged 0.74 over 3 years, and most mor- tality (73%) occurred between fall and winter. Seasonal survival was lowest (0.75) for the fall-winter 1997-1998, and was 20.90 during all spring-summer periods. Annual and seasonal survival rates did not differ by gender. Average annual survival was 0.77 for deer in wildland areas compared with 0.66 for deer in suburban areas, but these dif- ferences were not consistent between years and seasons. Survival over the entire 3-year study was low (0.38). Eight deer died from a combination of emaciation and disease, and almost all (92%) necropsied deer were in poor body condition. Fawn survival to 7 months was low (0.14, 95% CI = 0.02-0.26) and declined most rapidly during the first 1.5 months of life. Predation (n = 21) and abandonment (n = 6) were the most frequent known causes of death for fawns. Our results suggest that CWTD may have responded to density-dependent factors during this short-term study, although the effects of other environmental or intrinsic factors cannot be ignored. Fawn survival may be insufficient to produce enough recruits for population growth and eventual range expansion.

Hydrologic Controls on Sediment Retention in a Diversion-Fed Coastal Wetland

NASA Astrophysics Data System (ADS)

Keogh, M.; Kolker, A.; Snedden, G.; Renfro, A. A.

2017-12-01

The morphodynamics of river-dominated deltas are largely controlled by the supply and retention of sediment within deltaic wetlands and the rate of relative sea-level rise. Yet, sediment budgets for deltas are often poorly constrained. In the Mississippi River Delta, a system rapidly losing land to natural and anthropogenic causes, restoration efforts seek to build new land through the use of river diversions. At Davis Pond Freshwater Diversion, a new crevasse splay has emerged since construction was completed in 2002. Here, we use beryllium-7 (7Be) activity in sediment cores and USGS measurements of discharge and turbidity to calculate seasonal sediment input, deposition, and retention within the Davis Pond receiving basin. In winter/spring 2015, Davis Pond received 104,000 metric tons of sediment, 43.8% of which was retained within the basin. During this time, mean flow velocity was 0.21 m/s and turbidity was 56 formazin nephelometric units (FNU). In summer/fall 2015, Davis Pond received 35,100 metric tons of sediment, 82.1% of which was retained. Mean flow velocity in summer/fall was 0.10 m/s and turbidity was 55 FNU. The increase in sediment retention from winter/spring 2015 to summer/fall 2015 is likely due to the corresponding drop in water flow velocity, which allowed more sediment to settle out of suspension. Although high water discharge increases sediment input and deposition, increased turbulence associated with higher current velocity may increase sediment throughput and decrease the percent of sediments retained in the system. Sediment retention in Davis Pond is on the high end of the range seen in deltaic wetlands, likely due to the enclosed geometry of the receiving basin. Future diversion design and operation should target moderate water discharge and flow velocities in order to jointly maximize sediment deposition and retention and provide optimal conditions for delta growth.

An inventory of terrestrial mammals at national parks in the Northeast Temperate Network and Sagamore Hill National Historic Site

USGS Publications Warehouse

Gilbert, Andrew T.; O'Connell, Allan F.; Annand, Elizabeth M.; Talancy, Neil W.; Sauer, John R.; Nichols, James D.

2008-01-01

An inventory of mammals was conducted during 2004 at nine national park sites in the Northeast Temperate Network (NETN): Acadia National Park (NP), Marsh-Billings-Rockefeller National Historical Park (NHP), Minute Man NHP, Morristown NHP, Roosevelt-Vanderbilt National Historic Site (NHS), Saint-Gaudens NHS, Saugus Iron Works NHS, Saratoga NHP, and Weir Farm NHS. Sagamore Hill NHS, part of the Northeast Coastal and Barrier Network (NCBN), was also surveyed. Each park except Acadia NP was sampled twice, once in the winter/spring and again in the summer/fall. During the winter/spring visit, indirect measure (IM) sampling arrays were employed at 2 to 16 stations and included sampling by remote cameras, cubby boxes (covered trackplates), and hair traps. IM stations were established and re-used during the summer/fall sampling period. Trapping was conducted at 2 to 12 stations at all parks except Acadia NP during the summer/fall period and consisted of arrays of small-mammal traps, squirrel-sized live traps, and some fox-sized live traps. We used estimation-based procedures and probabilistic sampling techniques to design this inventory. A total of 38 species was detected by IM sampling, trapping, and field observations. Species diversity (number of species) varied among parks, ranging from 8 to 24, with Minute Man NHP having the most species detected. Raccoon (Procyon lotor), Virginia Opossum (Didelphis virginiana), Fisher (Martes pennanti), and Domestic Cat (Felis silvestris) were the most common medium-sized mammals detected in this study and White-footed Mouse (Peromyscus leucopus), Northern Short-tailed Shrew (Blarina brevicauda), Deer Mouse (P. maniculatus), and Meadow Vole (Microtus pennsylvanicus) the most common small mammals detected. All species detected are considered fairly common throughout their range including the Fisher, which has been reintroduced in several New England states. We did not detect any state or federal endangered or threatened species.

Stable carbon isotopes and levoglucosan for PM2.5 elemental carbon source apportionments in the largest city of Northwest China

NASA Astrophysics Data System (ADS)

Zhao, Zhuzi; Cao, Junji; Zhang, Ting; Shen, Zhenxing; Ni, Haiyan; Tian, Jie; Wang, Qiyuan; Liu, Suixin; Zhou, Jiamao; Gu, Jian; Shen, Ganzhou

2018-07-01

Stable carbon isotopes provide information on aerosol sources, but no extensive long-term studies of these isotopes have been conducted in China, and they have mainly been used for qualitative rather than quantitative purposes. Here, 24 h PM2.5 samples (n = 58) were collected from July 2008 to June 2009 at Xi'an, China. The concentrations of organic and elemental carbon (OC and EC), water-soluble OC, and the stable carbon isotope abundances of OC and EC were determined. In spring, summer, autumn and winter, the mean stable carbon isotope in OC (δ13COC) were -26.4 ± 0.6, -25.8 ± 0.7, -25.0 ± 0.6 and -24.4 ± 0.8‰, respectively, and the corresponding δ13CEC values were -25.5 ± 0.4, -25.5 ± 0.8, -25.2 ± 0.7 and -23.7 ± 0.6‰. Large δ13CEC and δ13COC values in winter can be linked to the burning coal for residential heating. Less biomass is burned during spring and summer than winter or fall (manifested in the levels of levoglucosan, i.e., 178, 85, 370, 935 ng m-3 in spring, summer, autumn, and winter), and the more negative δ13COC in the warmer months can be explained by the formation of secondary organic aerosols. A levoglucosan tracer method combined with an isotope mass balance analysis indicated that biomass burning accounted for 1.6-29.0% of the EC, and the mean value in winter (14.9 ± 7.5%) was 7 times higher than summer (2.1 ± 0.4%), with intermediate values of 6.1 ± 5.6 and 4.5 ± 2.4% in autumn and spring. Coal combustion accounted for 45.9 ± 23.1% of the EC overall, and the percentages were 63.0, 37.2, 36.7, and 33.7% in winter, autumn, summer and spring respectively. Motor vehicles accounted for 46.6 ± 26.5% of the annual EC, and these contributed over half (56.7-61.8%) of the EC in all seasons except winter. Correlations between motor vehicle-EC and coal combustion-EC with established source indicators (B(ghi)P and As) support the source apportionment results. This paper describes a simple and accurate method for apportioning the sources of EC, and the results may be beneficial for developing model simulations as well as controlling strategies in future.

Spatio-temporal distribution and environmental drivers of Barley yellow dwarf virus and vector abundance in Kansas.

PubMed

Enders, Laramy; Hefley, Trevor; Girvin, John; Whitworth, Robert; Smith, Charles

2018-05-11

Several aphid species transmit barley yellow dwarf, a globally destructive disease caused by viruses that infect cereal grain crops. Data from >400 samples collected across Kansas wheat fields in 2014 and 2015 were used to develop spatio-temporal models predicting the extent to which landcover, temperature and precipitation affect spring aphid vector abundance and presence of individuals carrying Barley yellow dwarf virus (BYDV). The distribution of Rhopalosiphum padi abundance was not correlated with climate or landcover, but Sitobion avenae abundance was positively correlated to fall temperature and negatively correlated to spring temperature and precipitation. The abundance of Schizaphis graminum was negatively correlated with fall precipitation and winter temperature. The incidence of viruliferous (+BYDV) R. padi was positively correlated with fall precipitation but negatively correlated with winter precipitation. In contrast, the probability of +BYDV S. avenae was unaffected by precipitation but was positively correlated with average fall temperatures and distance to nearest forest or shrubland. R. padi and S. avenae were more prevalent at Eastern sample sites where ground cover is more grassland than cropland, suggesting that grassland may provide over-summering sites for vectors and pose a risk as potential BYDV reservoirs. Nevertheless, land cover patterns were not strongly associated with differences in abundance or probability that viruliferous aphids were present.

Measures of Diet Quality across Calendar and Winter Holiday Seasons among Midlife Women: A 1-Year Longitudinal Study Using the Automated Self-Administered 24-Hour Recall.

PubMed

Jahns, Lisa; Johnson, LuAnn K; Scheett, Angela J; Stote, Kim S; Raatz, Susan K; Subar, Amy F; Tande, Desiree

2016-12-01

Systematic seasonal bias may confound efforts to estimate usual dietary intake and diet quality. Little is known about dietary quality over the winter holiday season. The aims of this study were to test for differences in intakes of energy, percentage of energy from macronutrients, fruits and vegetables, and diet quality measured using the Healthy Eating Index 2010 (HEI-2010) by calendar and winter holiday seasons. Longitudinal cohort design. Data were derived from the Life in All Seasons study. Two cohorts of women aged 40 to 60 years (N=52) from the greater Grand Forks, ND, area were followed for 1 year each between July 2012 and July 2014. Each woman completed an online diet recall using the Automated Self-Administered 24-Hour Recall every 10 days during the year, with a 92% response rate. Effects of calendar and winter holiday seasons on intakes of energy, percent energy from macronutrients, HEI-2010 total and component scores, and grams per day of individual fruits and vegetables were tested using mixed linear models. The mean total HEI-2010 score was 60.1±1.4. There were seasonal differences in some HEI-2010 component scores, but not in total scores. More lettuce or mixed lettuce salad was consumed during summer than during winter (P=0.034), and more fresh tomatoes were consumed during summer and fall compared with winter (P=0.001). More corn, berries, peaches and nectarines, and melons (P<0.001) were consumed during summer. There was no seasonal difference in reported intakes of energy (P=0.793). The total HEI-2010 score for dietary intake observed over the winter holiday season was lower than the rest of the year (P<0.001). Reported energy intake was not different (P=0.228). In this population, diet quality is significantly lower during the winter holiday period, but mostly consistent by season. Multiple recalls in any season can give a reasonable representation of usual overall diet quality throughout the year. Copyright © 2016 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Gaseous polycyclic aromatic hydrocarbon concentrations are higher in urban forests than adjacent open areas during summer but not in winter--Exploratory study.

PubMed

Viippola, Viljami; Rantalainen, Anna-Lea; Yli-Pelkonen, Vesa; Tervo, Peatta; Setälä, Heikki

2016-01-01

While the potential of plants to uptake polycyclic aromatic hydrocarbons (PAHs) is widely acknowledged, empirical evidence of the effects of this process on local atmospheric PAH concentrations and human health is tenuous. We measured gaseous PAH concentrations using passive samplers in urban tree-covered areas and adjacent open, treeless areas in a near-road environment in Finland to gain information on the ability of urban vegetation to improve air quality. The ability of urban, mostly deciduous, vegetation to affect PAHs was season dependent: during summer, concentrations were significantly higher in tree-covered areas, while in the fall, concentrations in open areas exceeded those in tree-covered areas. During winter, concentrations in tree-covered areas were either lower or did not differ from those in open areas. Results of this study imply that the commonly believed notion that trees unequivocally improve air quality does not apply to PAHs studied here. Copyright © 2015 Elsevier Ltd. All rights reserved.

Absence of circannual toxicity of parathion to starlings

USGS Publications Warehouse

Rattner, B.A.; Grue, C.E.

1990-01-01

Ambient temperature and season have been observed to influence the toxicity of several environmental pollutants in homeotherms. The circannual toxicity of ethyl parathion (EP) was examined in adult European starlings (Sturnus vulgaris). Groups of birds housed in outdoor pens received oral doses of EP (20-150 mg/kg body weight) in fall, winter, spring and summer (temperature range -3.3 to 36.7?C). The median lethal dosage (LD50), and brain and plasma cholinesterase inhibition, were found to be quite similar among seasons. There was some suggestion that EP may have been more toxic during hot weather (winter versus summer LD50 estimate [95% confidence interval]:160 [114-225] vs. 118 [102-136] mg/kg; P<0.10). In view of previous reports in which ambient temperature extremes and harsh weather have enhanced organophosphorus insecticide toxicity to birds, it is concluded that circannual toxicity studies should include measures of sensitivity (acute oral exposure) and vulnerability (dietary exposure) to better predict responses of free-ranging birds

ERS-1 Investigations of Southern Ocean Sea Ice Geophysics Using Combined Scatterometer and SAR Images

NASA Technical Reports Server (NTRS)

Drinkwater, M.; Early, D.; Long, D.

1994-01-01

Coregistered ERS-1 SAR and Scatterometer data are presented for the Weddell Sea, Antarctica. Calibrated image backscatter statistics are extracted from data acquired in regions where surface measurements were made during two extensive international Weddell Sea experiments in 1992. Changes in summer ice-surface conditions, due to temperature and wind, are shown to have a large impact on observed microwave backscatter values. Winter calibrated backscatter distributions are also investigated as a way of describing ice thickness conditions in different location during winter. Coregistered SAR and EScat data over a manned drifting ice station are used to illustrate the seasonal signature changes occurring during the fall freeze-up transition.

This (Sandpiper like) bird, as well as many other species keep watch over Moffett Field wetlands.

NASA Technical Reports Server (NTRS)

1991-01-01

This (Sandpiper like) bird, as well as many other species keep watch over Moffett Field wetlands. The shorebird in this picture is a greater yellowlegs (Tinga melanoleuca) which is a common bird found in our coastal salt marsh and tidal zones in winter months. Generally, they summer/breed up north in Canada and Alaska and then migrate in the fall to winter along the west coast of the U.S. and Mexico. Known for their loud call of a slightly descending series of three or more tew notes. Diet consists of small fish, insects, snails, worms, and tadpoles. used in Ames 60 yr. History NASA SP-2000-4314

Fall and winter movements and habitat use of the introduced American bullfrog (Lithobates catesbeiana) in a Montana pond

USGS Publications Warehouse

Sepulveda, Adam; Layhee, Megan J.

2015-01-01

American Bullfrogs (Lithobates catesbeianus) have been introduced across the globe, including in many northern latitude habitats where wetlands are ice-covered for part of the year. Because bullfrogs are less mobile at low temperatures, greater knowledge about their overwintering habitat may provide additional opportunities for control. Here, we described fall and early-winter movements and habitat associations for introduced juvenile bullfrogs in a pond within the Yellowstone River corridor near Billings, Montana, USA. We attached radio-transmitters to 13 juvenile bullfrogs and located individuals from 28 August to 10 December 2014. Bullfrogs moved greater distances in late summer and early autumn, and later during brief warming periods. Collectively, all bullfrog locations were distributed across a 15,384 m2 area during the active season, but contracted to a 130 m2 area in the east cove of the pond by the time the study site froze over. Our research provides evidence that managers in northern latitude regions like Montana may be able to use the long, cold winters to their advantage because the site-specific distributions of introduced bullfrogs contracted as temperatures decreased.

Seasonal use of shallow water habitat in the Lower Snake River reservoirs by juvenile fall Chinook salmon

USGS Publications Warehouse

Tiffan, Kenneth F.; Connor, William P.

2012-01-01

The U.S. Army Corps of Engineers (COE) is preparing a long term management plan for sediments that affect the authorized project purposes of the Lower Granite, Little Goose, Lower Monumental, and Ice Harbor reservoirs (hereafter, the lower Snake River reservoirs), and the area from the mouth of the Snake River to Ice Harbor Dam. We conducted a study from spring 2010 through winter 2011 to describe the habitat use by juvenile Chinook salmon within a selected group of shallow water habitat complexes (< 6 m deep) in the lower Snake River reservoirs to help inform the long-term plan. Natural fry and parr were present within all four shallow water habitat complexes that we studied from early spring through early summer, and parr ( = 40,345 ± 18,800 [error bound]) were more abundant than fry ( = 24,615 ± 5,701). Water < 2 m deep was highly used for rearing by natural fall Chinook salmon subyearlings (fry and parr combined; hereafter natural subyearlings) based on duration of use and relative group abundances during spring and summer, whereas the 2–6 m depth interval was more highly used by migratory hatchery fall Chinook salmon subyearlings and spring, summer, and fall Chinook salmon yearlings. Overall mean spring-summer apparent density of natural subyearlings was 15.5 times higher within the < 2 m depth interval than within the 2–6 m depth interval. Density of natural subyearlings also decreased as the distance a given shallow water habitat complex was located from the riverine spawning areas increased. Reservoir-type juveniles (or fish likely destined to become reservoir-type juveniles) were present in the lower Snake River reservoirs from fall 2010 through winter 2011; however, use of shallow water habitat by reservoir-type juveniles was limited during our study. We only collected 38 reservoir-type juveniles in shallow water habitat sites in beach and lampara seines during the fall. Radiotelemetry data revealed that though many tagged fish passed shallow water habitat sites, relatively few fish entered them and the median time fish spent within a given site was less than 1.4 h. Fish located by mobile tracking away from study sites were pelagically oriented, and generally not found over shallow water or close to shore. The findings in this report: (1) support the selection of natural fall Chinook subyearlings as the indicator group for determining the potential benefits of using dredge spoils to create shallow water habitat, (2) provide evidence for shallow water habitat use by natural subyearlings, (3) provide evidence against large-scale use of shallow water habitat by reservoir-type juveniles, (4) suggest that the depth criterion for defining shallow water habitat (i.e., < 6 m deep) warrants reconsideration, and (5) provide guidance for when to dredge and create shallow water habitat. Future research on habitat preference, feeding ecology, the food web, and intra-specific competition would help to better inform the long-term management plan.

Nuclear winter or nuclear fall?

NASA Astrophysics Data System (ADS)

Berger, André

Climate is universal. If a major modern nuclear war (i.e., with a large number of small-yield weapons) were to happen, it is not even necessary to have a specific part of the world directly involved for there to be cause to worry about the consequences for its inhabitants and their future. Indeed, smoke from fires ignited by the nuclear explosions would be transported by winds all over the world, causing dark and cold. According to the first study, by Turco et al. [1983], air surface temperature over continental areas of the northern mid-latitudes (assumed to be the nuclear war theatre) would fall to winter levels even in summer (hence the term “nuclear winter”) and induce drastic climatic conditions for several months at least. The devastating effects of a nuclear war would thus last much longer than was assumed initially. Discussing to what extent these estimations of long-term impacts on climate are reliable is the purpose of this article.

The role of atmospheric heat transport in the seasonal carbon dioxide cycle

NASA Technical Reports Server (NTRS)

Pollack, James B.; Haberle, R. M.; Murphy, James R.; Schaeffer, J.

1993-01-01

We have carried out numerical experiments with a general circulations model (GCM) and energy balance model of the martian atmosphere to define the importance of heat transported to the polar regions in determining the amount of CO2 condensed on the surface during the fall and winter seasons and the amount sublimated during the spring and summer seasons. In so doing, we performed both sensitivity experiments, in which the dust opacity was varied over the full range of its observed values, and annual simulations, in which the dust opacity varied continuously with seasonal data, in accord with measurements taken at the Viking landers. Dust opacity represents the key variable for determining the contribution of atmospheric heat advection to the energy budget in the polar regions. The amount of heat advected to the winter polar regions increases monotonically as the dust opacity at low and middle latitudes increases. However, the increase is sharpest between optical depths of 0 and 1 tends to level off at still higher optical depths. Heat advection is more important at times of CO2 condensation than CO2 sublimation, since the temperature gradients are much steeper in the winter hemisphere than in the summer hemisphere. Because dust opacity is much higher during northern winter than during southern winter, atmospheric heat advection reduces the amount of CO2 that condenses in the north by a much larger factor than it does in the south.

Detection of Nuclear Weapons and Materials: Science, Technologies, Observations

DTIC Science & Technology

2008-11-06

Nonproliferation Studies , 2004; Michael Levi, On Nuclear Terrorism, Cambridge, MA, Harvard University Press, 2007; and Carson Mark et al., “Can Terrorists Build...radiation and types of shielding. A DMOA study of real-world data found that the spectra from cargo differed between spring-summer and fall-winter; the study ...Algorithm and Resolution Studies ,” LLNL-TR-401531, December 31, 2007, by Padmini Sokkappa et al., pp. 21-22 This source is a report marked by Lawrence

Use of insoluble polyacrylate polymers to aid phytostabilization of mine soils: effects on plant growth and soil characteristics.

PubMed

Qu, G; de Varennes, A; Cunha-Queda, C

2010-01-01

We evaluated the use of polyacrylate polymers to aid phytostabilization of mine soils. In a pot experiment, perennial ryegrass was grown in a mine soil and in uncontaminated soil. Growth was stimulated in the polymer-amended mine soil compared with an unamended control, and water-extractable levels of soil Cu and Zn decreased after polymer application. In an experiment performed in six 60-cm-diameter cylinders filled with fertilized mine soil, polymers were applied to three cylinders, with the remainder used as unamended control. Total biomass produced by indigenous plant species sown in polymer-amended soil was 1.8 (Spring-Summer) or 2.4 times (Fall-Winter) greater than that of plants from unamended soil. The application of polymers to the mine soil led to the greatest activity of soil enzymes. Soil pH, biomass of Spergularia purpurea and Chaetopogon fasciculatus, and activities of protease and cellulase had large loadings on principal component (PC)1, whereas growth of Briza maxima and the activities of urease, acid phosphatase, and beta-glucosidase had large loadings on PC2. The treatments corresponding to controls were located on the negative side of PC1 and PC2. Amended treatments were on the positive side of PC2 (Spring-Summer) or on the positive side of PC1 (Fall-Winter), demonstrating differential responses of plants and soil parameters in the two growth cycles.

[Spatial-temporal distributions of dissolved inorganic carbon and its affecting factors in the Yellow River estuary].

PubMed

Guo, Xing-Sen; Lü, Ying-Chun; Sun, Zhi-Gao; Wang, Chuan-Yuan; Zhao, Quan-Sheng

2015-02-01

Estuary is an important area contributing to the global carbon cycle. In order to analyze the spatial-temporal distribution characteristics of the dissolved inorganic carbon (DIC) in the surface water of Yellow River estuary. Samples were collected in spring, summer, fall, winter of 2013, and discussed the correlation between the content of DIC and environmental factors. The results show that, the DIC concentration of the surface water in Yellow River estuary is in a range of 26.34-39.43 mg x L(-1), and the DIC concentration in freshwater side is higher than that in the sea side. In some areas where the salinity is less than 15 per thousand, the DIC concentration appears significant losses-the maximum loss is 20.46%. Seasonal distribution of performance in descending order is spring, fall, winter, summer. Through principal component analysis, it shows that water temperature, suspended solids, salinity and chlorophyll a are the main factors affecting the variation of the DIC concentration in surface water, their contribution rate is as high as 83% , and alkalinity, pH, dissolved organic carbon, dissolved oxygen and other factors can not be ignored. The loss of DIC in the low area is due to the calcium carbonate sedimentation. DIC presents a gradually increasing trend, which is mainly due to the effects of water retention time, temperature, outside input and environmental conditions.

Variation of Surface Air Temperature in Relation to El Nino and Cataclysmic Volcanic Eruptions, 1796-1882

NASA Technical Reports Server (NTRS)

Wilson, Robert M.

1999-01-01

During the contemporaneous interval of 1796-1882 a number of significant decreases in temperature are found in the records of Central England and Northern Ireland. These decreases appear to be related to the occurrences of El Nino and/or cataclysmic volcanic eruptions. For example, a composite of residual temperatures of the Central England dataset, centering temperatures on the yearly onsets of 20 El Nino of moderate to stronger strength, shows that, on average, the change in temperature varied by about +/- 0.3 C from normal being warmer during the boreal fall-winter leading up to the El Nino year and cooler during the spring-summer of the El Nino year. Also, the influence of El Nino on Central England temperatures appears to last about 1-2 years. Similarly, a composite of residual temperatures of the Central England dataset, centering temperatures on the month of eruption for 26 cataclysmic volcanic eruptions, shows that, on average, the change in temperature decreased by about 0.1 - 0.2 C, typically, 1-2 years after the eruption, although for specific events, like Tambora, the decrease was considerably greater. Additionally, tropical eruptions appear to produce greater changes in temperature than extratropical eruptions, and eruptions occurring in boreal spring-summer appear to produce greater changes in temperature than those occurring in fall-winter.

Relation Between Lightning Activity of Summer and Winter Thunderclouds and Surface Electric Field Variation, Japan

NASA Technical Reports Server (NTRS)

Michimoto, K.; Shimura, T.; Suzuki, T.

1999-01-01

In winter, active convective clouds frequently form along the coastline of the Hokuriku district, in association with strong advection of Siberian air masses over the Sea of Japan. On the other hand, in summer, many thunderclouds form in the Kanto region in the afternoon every day. Summer and winter thunderclouds were investigated by field works, operation of the C- and X-band weather radars and a car-borne fieldmill. The investigation found a very close relation between the temporal variation of 3-dimensional radar echo and surface electric field magnitude detected by a car-borne fieldmill in the case of summer thunderclouds and winter convective clouds or thunderclouds. The study probed the close relation among radar echoes, quantity of thunderclouds and surface electric field magnitude in the summer and winter seasons. We think that summer thundercloud activity can basically be equated with winter thundercloud lightning activity, except that the magnitude of surface electric field under summer thunderclouds in the case of the Kanto region cannot be equated with that under winter thunderclouds in the case of the Hokuriku district in winter.

Transportation of market-weight pigs: I. effect of season, truck type, and location within truck on behavior with a two-hour transport.

PubMed

Torrey, S; Bergeron, R; Widowski, T; Lewis, N; Crowe, T; Correa, J A; Brown, J; Gonyou, H W; Faucitano, L

2013-06-01

There is evidence that season and truck/trailer design play important roles in pig welfare during transportation although little is known about their interaction and effect on pig behavior. This experiment was designed to examine the influence of season and truck/trailer design on the behavior during loading, transit, unloading, and lairage of market-weight pigs transported to slaughter. A total of 3,756 pigs were transported on either a 3-deck pot-belly trailer (PB; n = 181 pigs/wk in 8 experimental compartments) or a double-decker hydraulic truck (DD; n = 85 pigs/wk in 4 compartments) for 2 h to a commercial abattoir in summer and winter (6 wk in each season). Density on both vehicles was 0.40 m(2)/pig. Accounting for the number of pigs, loading took longer (P = 0.033) onto the DD than the PB, but season did not (P = 0.571) influence loading time. Pigs loaded onto the PB moved backward more (P = 0.003) frequently than those loaded onto the DD. The frequency of tapping by handler was the lone handling intervention affected by truck type, with more (P = 0.014) tapping needed to move pigs on and off DD than PB. During loading, pigs made more (P < 0.001) slips and falls, overlaps, 180° turns, underlaps, and vocalizations in winter compared with summer. On truck, more (P < 0.001) pigs were standing on the DD at the farm and in transit than on the PB whereas more (P = 0.012) pigs were lying in transit in summer than in winter. Pigs took longer to unload (P < 0.001) from the PB than the DD, but no difference between vehicles (P = 0.473) in latency to rest in lairage was found. Pigs slipped and fell more (P < 0.001) during unloading, took longer (P < 0.001) to unload, and had a shorter (P = 0.006) latency to rest in lairage in winter than summer. Vehicle design, in particular the presence of ramps, influenced pig behavior before, during, and after transportation, regardless of the season. Season affected loading and unloading behavior, especially in terms of slips and falls on the ramp, and differences in truck/trailer designs were also partly to blame for unloading times and lairage behavior. Ramps and changes in direction during unloading appear to slow down the handling process.

Fall Freeze-up of Sea Ice in the Beaufort-Chukchi Seas Using ERS-1 SAR and Buoy Data

NASA Technical Reports Server (NTRS)

Holt, B.; Winebrenner, B.; D., Nelson E.

1993-01-01

The lowering of air temperatures below freezing in the fall indicates the end of summer melt and the onset of steady sea ice growth. The thickness and condition of ice that remains at the end of summer has ramifications for the thickness that that ice will attain at the end of the following winter. This period also designates a shifting of key fluxes from upper ocean freshening from ice melt to increased salinity from brine extraction during ice growth. This transitional period has been examined in the Beaufort and Chukchi Seas using ERS-1 SAR imagery and air temperatures from drifting buoys during 1991 and 1992. The SAR imagery is used to examine the condition and types of ice present in this period. Much of the surface melt water has drained off at this time. Air temperatures from drifting buoys coincident in time and within 100 km radius of the SAR imagery have been obtained...

Transfer coefficient of 226Ra from vegetation to meadow voles, Microtus pennsylvanicus, on U mill tailings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cloutier, N.R.; Clulow, F.V.; Lim, T.P.

The 226Ra level in vegetation growing on U mine tailings in Elliot Lake, Ontario, Canada, was 211 + 22 mBq g-1 (dry weight) compared to less than 7 mBq g-1 (dry weight) in material from a control site. Skeletons of meadow voles (Microtus pennsylvanicus) established on the tailings had concentrations of 226Ra of 6083 +/- 673 mBq per animal in winter; 7163 +/- 1077 mBq per animal in spring; 1506 +/- 625 mBq per animal in summer; and 703 +/- 59 mBq per animal in fall, compared to less than 7 mBq per animal in controls. The /sup 226/Ra transfermore » coefficient from vegetation to voles (defined as total millibecquerels of /sup 226/Ra in adult vole per total millibecquerels of 226Ra consumed by the vole in its lifetime) was calculated as 4.6 +/- 2.9 X 10(-2) in summer and 2.8 +/- 0.6 X 10(-2) in fall.« less

Cognitive-behavioral therapy vs. light therapy for preventing winter depression recurrence: study protocol for a randomized controlled trial.

PubMed

Rohan, Kelly J; Evans, Maggie; Mahon, Jennifer N; Sitnikov, Lilya; Ho, Sheau-Yan; Nillni, Yael I; Postolache, Teodor T; Vacek, Pamela M

2013-03-21

Seasonal affective disorder (SAD) is a subtype of recurrent depression involving major depressive episodes during the fall and/or winter months that remit in the spring. The central public health challenge in the management of SAD is prevention of winter depression recurrence. Light therapy (LT) is the established and best available acute SAD treatment. However, long-term compliance with daily LT from first symptom through spontaneous springtime remission every fall/winter season is poor. Time-limited alternative treatments with effects that endure beyond the cessation of acute treatment are needed to prevent the annual recurrence of SAD. This is an NIMH-funded R01-level randomized clinical trial to test the efficacy of a novel, SAD-tailored cognitive-behavioral group therapy (CBT) against LT in a head-to-head comparison on next winter outcomes. This project is designed to test for a clinically meaningful difference between CBT and LT on depression recurrence in the next winter (the primary outcome). This is a concurrent two-arm study that will randomize 160 currently symptomatic community adults with major depression, recurrent with seasonal pattern, to CBT or LT. After 6 weeks of treatment in the initial winter, participants are followed in the subsequent summer, the next winter, and two winters later. Key methodological issues surround timing study procedures for a predictably recurrent and time-limited disorder with a focus on long-term outcomes. The chosen design answers the primary question of whether prior exposure to CBT is associated with a substantially lower likelihood of depression recurrence the next winter than LT. This design does not test the relative contributions of the cognitive-behavioral treatment components vs. nonspecific factors to CBT's outcomes and is not adequately powered to test for differences or equivalence between cells at treatment endpoint. Alternative designs addressing these limitations would have required more patients, increased costs, and reduced power to detect a difference in the primary outcome. Clinicaltrials.gov identifier NCT01714050.

Role of river flow and sediment mobilization in riparian alder establishment along a bedrock-gravel river, South Fork Eel River, California

NASA Astrophysics Data System (ADS)

Jablkowski, P.; Johnson, E. A.; Martin, Y. E.

2017-10-01

Climatic, hydraulics, hydrologic, and fluvial geomorphic processes are the main drivers of riparian white alder (Alnus rhombifolia Nutt.) distribution in northern California. The Mediterranean climate and canyon bound, bedrock-gravel morphology of the South Fork Eel have a distinct effect on these processes. White alder seeds are preferentially deposited on river bars where river hydraulics create eddies coinciding with the downstream part of riffles and the upstream part of pools. Seeds are generally deposited below bankfull elevations by the descending hydrograph during the spring season in this Mediterranean climate. For successful germination and establishment, the seeds must be deposited at a location such that they are not remobilized by late spring flows. The summer establishment period is defined from the date of seed deposition and germination to the fall/winter date of river sediment mobilization. Seedling root growth rate decreases exponentially with decreasing water potential. However, seedlings are shown not to be generally limited by water availability at the elevations they are most commonly deposited. The establishment of white alder seedlings following the first summer will therefore depend on their ability to resist fall/winter high flows. The method proposed here compares the predicted rooting depth to predicted sediment scour rates. The length of the establishment period rather than water availability determines final seedling rooting depth. Over the past 40 years, very few years had establishment periods that were long enough or had fast enough alder growth rates to survive winter floods that often scour deeper than the total root length. The low survival of seedlings in the first autumn season following germination is believed to be a principal reason for the missing age classes often found in alder distributions along rivers.

Fractal analysis of narwhal space use patterns.

PubMed

Laidre, Kristin L; Heide-Jørgensen, Mads P; Logsdon, Miles L; Hobbs, Roderick C; Dietz, Rune; VanBlaricom, Glenn R

2004-01-01

Quantifying animal movement in response to a spatially and temporally heterogeneous environment is critical to understanding the structural and functional landscape influences on population viability. Generalities of landscape structure can easily be extended to the marine environment, as marine predators inhabit a patchy, dynamic system, which influences animal choice and behavior. An innovative use of the fractal measure of complexity, indexing the linearity of movement paths over replicate temporal scales, was applied to satellite tracking data collected from narwhals (Monodon monoceros) (n = 20) in West Greenland and the eastern Canadian high Arctic. Daily movements of individuals were obtained using polar orbiting satellites via the ARGOS data location and collection system. Geographic positions were filtered to obtain a daily good quality position for each whale. The length of total pathway was measured over seven different temporal length scales (step lengths), ranging from one day to one week, and a seasonal mean was calculated. Fractal dimension (D) was significantly different between seasons, highest during summer (D = 1.61, SE 0.04) and winter (D = 1.69, SE 0.06) when whales made convoluted movements in focal areas. Fractal dimension was lowest during fall (D = 1.34, SE 0.03) when whales were migrating south ahead of the forming sea ice. There were no significant effects of size category or sex on fractal dimension by season. The greater linearity of movement during the migration period suggests individuals do not intensively forage on patchy resources until they arrive at summer or winter sites. The highly convoluted movements observed during summer and winter suggest foraging or searching efforts in localized areas. Significant differences between the fractal dimensions on two separate wintering grounds in Baffin Bay suggest differential movement patterns in response to the dynamics of sea ice.

Lake Stability and Winter-Spring Transitions: Decoupled Ice Duration and Winter Stratification

NASA Astrophysics Data System (ADS)

Daly, J.; Dana, S.; Neal, B.

2016-12-01

Ice-out is an important historical record demonstrating the impact of warmer air temperatures on lake ice. To better understand regional differences in ice-out trends, to characterize the thermal dynamics of smaller mountain lakes, and to develop baseline data for Maine's high elevations landscapes, sub-hourly water temperatures have been collected in over a dozen of Maine's mountain lakes since 2010. Both surface water and hypolimnion temperature data are recorded year-round, facilitating the determination of ice-in, ice-out, and the duration of winter stratification. The multi-year record from sites across as 250 km transect allows us to compare spatial variability related to lake morphometry and location with inter-annual variability related to local weather. All of the study lakes are large enough to stratify during the summer and mix extensively during the fall. Most years, our data show that the onset of winter stratification is nearly synchronous across the study area and is associated with cold air temperatures. Winter stratification can begin days to weeks before ice-in; the timing of ice-in shows more variability, with both elevation and basin aspect influencing the timing. Ice-out shows both the anticipated spatial and interannual variability; some years there is strong coherence between locations while other years show high variability, possibly a function of differences in snowpack. Ice-out is not always immediately followed by the end of winter stratification, there is sometimes a lag of days to weeks before the lakes mix. If the warm temperatures that lead to ice-out are followed by calm days without significant wind, the surface of some lakes begins to warm quickly maintaining the density difference and prolonging winter stratification. The longer the lag time, the stronger the density difference becomes which may also result in a very brief period of mixing in the spring prior to set-up of summer stratification. This year's El Niño event resulted in very late ice-in, leading to an unusually short ice duration period at most sites. However, ice-out for these sites was within the range observed previous years and there may not be a significant impact on summer water temperatures.

Phenotypic plasticity and climate change: can polar bears respond to longer Arctic summers with an adaptive fast?

PubMed

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

2018-02-01

Plasticity in the physiological and behavioural responses of animals to prolonged food shortages may determine the persistence of species under climate warming. This is particularly applicable for species that can "adaptively fast" by conserving protein to protect organ function while catabolizing endogenous tissues. Some Ursids, including polar bears (Ursus maritimus), adaptively fast during winter hibernation-and it has been suggested that polar bears also employ this strategy during summer. We captured 57 adult female polar bears in the Southern Beaufort Sea (SBS) during summer 2008 and 2009 and measured blood variables that indicate feeding, regular fasting, and adaptive fasting. We also assessed tissue δ 13 C and δ 15 N to infer diet, and body condition via mass and length. We found that bears on shore maintained lipid and protein stores by scavenging on bowhead whale (Balaena mysticetus) carcasses from human harvest, while those that followed the retreating sea ice beyond the continental shelf were food deprived. They had low ratios of blood urea to creatinine (U:C), normally associated with adaptive fasting. However, they also exhibited low albumin and glucose (indicative of protein loss) and elevated alanine aminotransferase and ghrelin (which fall during adaptive fasting). Thus, the ~ 70% of the SBS subpopulation that spends summer on the ice experiences more of a regular, rather than adaptive, fast. This fast will lengthen as summer ice declines. The resulting protein loss prior to winter could be a mechanism driving the reported correlation between summer ice and polar bear reproduction and survival in the SBS.

Intra- and Inter- annual PM2.5 variations in the Arctic region during 2003-2017 based on the NASA's MERRA-2 re-analysis data

NASA Astrophysics Data System (ADS)

Yasunari, T. J.; Kim, K. M.; da Silva, A. M., Jr.

2017-12-01

We examined the intra- and inter-annual variations of PM2.5 in the Arctic region based on monthly mean aerosols (dust, sulfate, sea salt, and carbonaceous aerosols) and PM2.5 from NASA's latest reanalysis, MERRA2. We focus on the time period from January 2003 to the recent month (May 2017). The domain of the Arctic region was defined as North of 66.5N in this study. Although there are some exceptions, the largest contributions of dust, ammonium sulfate, sea salt, and carbonaceous aerosols (i.e., Black Carbon, BC, and Particulate Organic Matter, POM) to the fractions of PM2.5 were mainly seen in spring, spring, fall, and summer, respectively. During the focused time period, the fractions of dust, ammonium sulfate, sea salt, BC, and POM explains 2.7-42.5%, 9.5-37.5%, 16.7-73.1%, 0.5-2.8%, 1.5-58.0% of the Arctic PM2.5, respectively. If we picked up the top 10 high PM2.5 months during the period, those were separated into two seasons: summer (eight months) and winter (two months). For the composites of the summer months above, the areas with higher PM2.5 were Siberia, Far East, Alaska, and Canada and the regions where POM fractions were larger, implying the contributions from smokes due to active wildfires in summer seasons. For the winter months, the mixture of increased dust, ammonium sulfate, and sea salt was seen. However, the highest PM2.5 in the Arctic region was seen from the Kara Sea, Barents Sea, and Greenland Sea over which the contribution of sea salt was very large. This means the sea salt aerosols were the main contributor to the high PM2.5 winter months there. Based on our MERRA-2 analyses, continuous monitoring and development for better forecasting wildfire activities in summer and sea salt emissions in winter would be the keys for better understanding of the air quality in the Arctic region including mitigation and measures of it in the future.

Summer Leeside Rainfall Maxima over the Island of Hawaii

NASA Astrophysics Data System (ADS)

Huang, Y. F.; Chen, Y. L.

2016-12-01

The Kona area on the leeside in the island of Hawaii has distinctive summer rainfall maxima. The primary physical processes for the summer rainfall maxima in Kona are analyzed by comparing it with the winter rainfall. The annual and diurnal cycles there are investigated by employing the Fifth-generation Pennsylvania State University-NCAR Mesoscale Model coupled with the advanced land surface model from June 2004 and February 2010. During the summer, the nocturnal rainfall maximum adjacent to the Kona coast is larger than in winter because of the stronger, moister westerly reversed flow and offshore flow in summer. Comparisons between winter trade-wind days and winter mean show that the leeside Kona rainfall offshore in winter mainly occurs under trade-wind conditions. Moreover, the model results also attest to the impact of moisture content on the Kona leeside rainfall offshore. Comparisons between winter and summer trade-wind days indicate that upslope flows on the Kona slopes are stronger and the moisture content from the westerly reversed flow is higher in summer than in winter. The rainfall maximum on the lower Kona slopes is more pronounced in summer than in winter as a result of enhanced orographic lifting due to stronger upslope flow in the afternoon hours and the moister westerly reversed flow offshore, which merges with the upslope flow inland.

Version 1.3 AIM SOFIE measured methane (CH4): Validation and seasonal climatology

NASA Astrophysics Data System (ADS)

Rong, P. P.; Russell, J. M.; Marshall, B. T.; Siskind, D. E.; Hervig, M. E.; Gordley, L. L.; Bernath, P. F.; Walker, K. A.

2016-11-01

The V1.3 methane (CH4) measured by the Aeronomy of Ice in the Mesosphere (AIM) Solar Occultation for Ice Experiment (SOFIE) instrument is validated in the vertical range of 25-70 km. The random error for SOFIE CH4 is 0.1-1% up to 50 km and degrades to 9% at ˜ 70 km. The systematic error remains at 4% throughout the stratosphere and lower mesosphere. Comparisons with CH4 data taken by the SCISAT Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) and the Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) show an agreement within 15% in the altitude range 30-60 km. Below 25 km SOFIE CH4 is systematically higher (≥20%), while above 65 km it is lower by a similar percentage. The sign change from the positive to negative bias occurs between 55 km and 60 km (or 40 km and 45 km) in the Northern (or Southern) Hemisphere. Methane, H2O, and 2CH4 + H2O yearly differences from their values in 2009 are examined using SOFIE and MIPAS CH4 and the Aura Microwave Limb Sounder (MLS) measured H2O. It is concluded that 2CH4 + H2O is conserved with altitude up to an upper limit between 35 km and 50 km depending on the season. In summer this altitude is higher. In the Northern Hemisphere the difference relative to 2009 is the largest in late spring and the established difference prevails throughout summer and fall, suggesting that summer and fall are dynamically quiet. In both hemispheres during winter there are disturbances (with a period of 1 month) that travel downward throughout the stratosphere with a speed similar to the winter descent.

Characteristics of carbonaceous particles in Beijing during winter and summer 2003

NASA Astrophysics Data System (ADS)

Yu, J. H.; Chen, T.; Guinot, B.; Cachier, H.; Yu, T.; Liu, W. Q.; Wang, X.

2006-05-01

Campaigns were conducted to measure Organic Carbon (OC) and Elemental Carbon (EC) in PM2.5 during winter and summer 2003 in Beijing. Modest differences of PM2.5 and PM10 mean concentrations were observed between the winter and summer campaigns. The mean PM2.5/PM10 ratio in both seasons was around 60%, indicating PM2.5 contributed significantly to PM10. The mean concentrations of OC and EC in PM2.5 were 11.2+/-7.5 and 6.0+/-5.0 mu g m(-3) for the winter campaign, and 9.4+/-2.1 and 4.3+/-3.0 mu g m(-3) for the summer campaign, respectively. Diurnal concentrations of OC and EC in PM2.5 were found high at night and low during the daytime in winter, and characterized by an obvious minimum in the summer afternoon. The mean OC/EC ratio was 1.87+/-0.09 for winter and 2.39+/-0.49 for summer. The higher OC/EC ratio in summer indicates some formation of Secondary Organic Carbon (SOC). The estimated SOC was 2.8 mu g m(-3) for winter and 4.2 mu g m(-3) for summer.

Potential Impacts of Extended Winter Navigation upon Migratory Birds of the Upper U.S. Great Lakes. Great Lakes-St. Lawrence Seaway Navigation Season Extension Program

DTIC Science & Technology

1982-09-01

pattern in the beaching rate is caused mostly by high mortality of young gulls in late summer and fall before and during migration. Almost no oiling of...Most Frequently Beached Birds From 1978 to 1980 . . . . . . . . . 167 54 Age Composition of Beached Ring-billed Gulls . . . . . . . . . . 168 55 Age... Composition of Beached Herring Gulls . . . . . . . . . . . . 169 ix LIST OF TABLES (continued) B16 Summary of Selected Birds Present on Christmas

Riveting Two-Dimensional Materials: Exploring Strain Physics in Atomically Thin Crystals with Microelectromechanical Systems

NASA Astrophysics Data System (ADS)

Christopher, Jason W.

This thesis includes four studies that explore and compare the impacts of four contributing factors resulting in regional climate change on the North Slope of Alaska based on a numerical simulation approach. These four contributing factors include global warming due to changes in radiative forcing, sea ice decline, earlier Arctic lake ice-off, and atmospheric circulation change over the Arctic. A set of dynamically downscaled regional climate products has been developed for the North Slope of Alaska over the period from 1950 up to 2100. A fine grid spacing (10 km) is employed to develop products that resolve detailed mesoscale features in the temperature and precipitation fields on the North Slope of Alaska. Processes resolved include the effects of topography on regional climate and extreme precipitation events. The Representative Concentration Pathway (RCP) 4.5 scenario projects lower rates of precipitation and temperature increase than RCP8.5 compared to the historical product. The increases of precipitation and temperature trends in the RCP8.5 projection are higher in fall and winter compared to the historical product and the RCP4.5 projection. The impacts of sea ice decline are addressed by conducting sensitivity experiments employing both an atmospheric model and a permafrost model. The sea ice decline impacts are most pronounced in late fall and early winter. The near surface atmospheric warming in late spring and early summer due to sea ice decline are projected to be stronger in the 21st century. Such a warming effect also reduces the total cloud cover on the North Slope of Alaska in summer by destabilizing the atmospheric boundary layer. The sea ice decline warms the atmosphere and the permafrost on the North Slope of Alaska less strongly than the global warming does, while it primarily results in higher seasonal variability of the positive temperature trend that is bigger in late fall and early winter than in other seasons. The ongoing and projected earlier melt of the Arctic lake ice also contributes to regional climate change on the Northern coast of Alaska, though only on a local and seasonal scale. Heat and moisture released from the opened lake surface primarily propagate downwind of the lakes. The impacts of the earlier lake ice-off on both the atmosphere and the permafrost underneath are comparable to those of the sea ice decline in late spring and early summer, while they are roughly six times weaker than those of sea ice decline in late fall and early winter. The permafrost warming resulted from the earlier lake ice-off is speculated to be stronger with more snowfall expected in the 21st century, while the overall atmospheric warming of global origin is speculated to continue growing. Two major Arctic summer-time climatic variability patterns, the Arctic Oscillation (AO) and the Arctic Dipole (AD), are evaluated in 12 global climate models in Coupled Model Intercomparison Program Phase 5 (CMIP5). A combined metric ranking approach ranks the models by the Pattern Correlation Coefficients (PCCs) and explained variances calculated from the model-produced summer AO and AD over the historical period. Higher-ranked models more consistently project a positive trend of the summer AO index and a negative trend of summer AD index in their RCP8.5 projections. Such long-term trends of large-scale climate patterns will inhibit the increase in air temperature while favoring the increase in precipitation on the North Slope of Alaska. In summary, this thesis bridges the gaps by quantifying the relative importance of multiple contributing factors to the regional climate change on the North Slope of Alaska. Global warming is the leading contributing factor, while other factors primarily contribute to the spatial and temporal asymmetries of the regional climate change. The results of this thesis lead to a better understanding of the physical mechanisms behind the climatic impacts to the hydrological and ecological changes of the North Slope of Alaska that have been become more severe and more frequent. They, together with the developed downscaling data products, serve as the climatic background information in such fields of study.

Seasonal influences on sleep and executive function in the migratory White-crowned Sparrow (Zonotrichia leucophrys gambelii)

PubMed Central

2010-01-01

Background We have previously shown that the White-crowned Sparrow (WCS) decreases sleep by 60% during a period of migratory restlessness relative to a non-migratory period when housed in a 12 h light: 12 h dark cycle. Despite this sleep reduction, accuracy of operant performance was not impaired, and in fact rates of responding were elevated during the migratory period, effects opposite to those routinely observed following enforced sleep deprivation. To determine whether the previously observed increases in operant responding were due to improved performance or to the effects of migration on activity level, here we assessed operant performance using a task in which optimal performance depends on the bird's ability to withhold a response for a fixed interval of time (differential-reinforcement-of-low-rate-behavior, or DRL); elevated response rates ultimately impair performance by decreasing access to food reward. To determine the influence of seasonal changes in day length on sleep and behavioral patterns, we recorded sleep and assessed operant performance across 4 distinct seasons (winter, spring, summer and fall) under a changing photoperiod. Results Sleep amount changed in response to photoperiod in winter and summer, with longest sleep duration in the winter. Sleep duration in the spring and fall migratory periods were similar to what we previously reported, and were comparable to sleep duration observed in summer. The most striking difference in sleep during the migratory periods compared to non-migratory periods was the change from discrete day-night temporal organization to an almost complete temporal fragmentation of sleep. The birds' ability to perform on the DRL task was significantly impaired during both migratory periods, but optimal performance was sustained during the two non-migratory periods. Conclusions Birds showed dramatic changes in sleep duration across seasons, related to day length and migratory status. Migration was associated with changes in sleep amount and diurnal distribution pattern, whereas duration of sleep in the non-migratory periods was largely influenced by the light-dark cycle. Elevated response rates on the DRL task were observed during migration but not during the short sleep duration of summer, suggesting that the migratory periods may be associated with decreased inhibition/increased impulsivity. Although their daily sleep amounts and patterns may vary by season, birds are susceptible to sleep loss throughout the year, as evidenced by decreased responding rates following enforced sleep deprivation. PMID:20670404

Multi-Year Elevation Changes Near the West Margin of the Greenland Ice Sheet from Satellite Radar Altimetry

NASA Technical Reports Server (NTRS)

Lingle, Craig S.; Brenner, Anita C.; Zwally, H. Jay; DiMarzio, John P.

1991-01-01

Mean changes in the surface elevation near the west margin of the Greenland ice sheet are measured using Seasat altimetry and altimetry from the Geosat Exact Repeat Mission (ERM). The Seasat data extend from early July through early October 1978. The ERM data extend from winter 1986-87 through fall 1988. Both seasonal and multi-year changes are measured using altimetry referenced to GEM T2 orbits. The possible effects of orbit error are minimized by adjusting the orbits into a common ocean surface. Seasonal mean changes in the surface height are recognizable during the Geosat ERM. The multi-year measurements indicate the surface was lower by 0.4 +/- 0.4 m on average in late summer 1987 than in late summer 1978. The surface was lower by 0.2 +/- 0.5 m on average in late summer 1988 than in late summer 1978. As a control case, the computations art also carried out using altimetry referenced to orbits not adjusted into a common ocean surface.

Climatological characteristics of high altitude wind shear and lapse rate layers

NASA Technical Reports Server (NTRS)

Ehernberger, L. J.; Guttman, N. B.

1981-01-01

Indications of the climatological distribution of wind shear and temperature lapse and inversion rates as observed by rawinsonde measurements over the western United States are recorded. Frequencies of the strongest shear, lapse rates, and inversion layer strengths were observed for a 1 year period of record and were tabulated for the lower troposphere, the upper troposphere, and five altitude intervals in the lower stratosphere. Selected bivariate frequencies were also tabulated. Strong wind shears, lapse rates, and inversion are observed less frequently as altitude increases from 175 millibars to 20 millibars. On a seasonal basis the frequencies were higher in winter than in summer except for minor influences due to increased tropopause altitude in summer and the stratospheric wind reversal in the spring and fall.

Spring and summer survival of female mallards from northcentral Minnesota

USGS Publications Warehouse

Kirby, R.E.; Cowardin, L.M.

1986-01-01

Seasonal survival of 109 adult female mallards (Anas platyrhynchos) fitted with radio transmitters was evaluated in northcentral Minnesota during 1968-74. Survival rates for the 169-day breeding and postbreeding period were: 1.0 during nest initiation (36 days), 0.798 during incubation (28 days), 0.943 during brood rearing (51 days), 0.947 during molt (26 days), and 1.0 during premigration (28 days). Survival for the 169-day spring-summer period was 0.713 for adult females remaining on the study area. Fall-winter survival was estimated at 0.881 for those adult birds remaining on the study area throughout the summer. The data confirm speculation on relative risk to females of various phases of the mallard reproductive cycle and support previous conclusions that the northcentral Minnesota breeding mallard population is not self sustaining. The value of learning further details of processes affecting specific seasonal mortality factors for both adult and young waterfowl is emphasized.

Meteorological characteristics and overland precipitation impacts of atmospheric rivers affecting the West coast of North America based on eight years of SSM/I satellite observations

USGS Publications Warehouse

Neiman, P.J.; Ralph, F.M.; Wick, G.A.; Lundquist, J.D.; Dettinger, M.D.

2008-01-01

The pre-cold-frontal low-level jet within oceanic extratropical cyclones represents the lower-tropospheric component of a deeper corridor of concentrated water vapor transport in the cyclone warm sector. These corridors are referred to as atmospheric rivers (ARs) because they are narrow relative to their length scale and are responsible for most of the poleward water vapor transport at midlatitudes. This paper investigates landfalling ARs along adjacent north- and south-coast regions of western North America. Special Sensor Microwave Imager (SSM/ I) satellite observations of long, narrow plumes of enhanced integrated water vapor (IWV) were used to detect ARs just offshore over the eastern Pacific from 1997 to 2005. The north coast experienced 301 AR days, while the south coast had only 115. Most ARs occurred during the warm season in the north and cool season in the south, despite the fact that the cool season is climatologically wettest for both regions. Composite SSM/I IWV analyses showed landfalling wintertime ARs extending northeastward from the tropical eastern Pacific, whereas the summertime composites were zonally oriented and, thus, did not originate from this region of the tropics. Companion SSM/I composites of daily rainfall showed significant orographic enhancement during the landfall of winter (but not summer) ARs. The NCEP-NCAR global reanalysis dataset and regional precipitation networks were used to assess composite synoptic characteristics and overland impacts of landfalling ARs. The ARs possess strong vertically integrated horizontal water vapor fluxes that, on average, impinge on the West Coast in the pre-cold-frontal environment in winter and post-cold-frontal environment in summer. Even though the IWV in the ARs is greater in summer, the vapor flux is stronger in winter due to much stronger flows associated with more intense storms. The landfall of ARs in winter and north-coast summer coincides with anomalous warmth, a trough offshore, and ridging over the Intermountain West, whereas the south-coast summer ARs coincide with relatively cold conditions and a near-coast trough. ARs have a much more profound impact on near-coast precipitation in winter than summer, because the terrain-normal vapor flux is stronger and the air more nearly saturated in winter. During winter, ARs produce roughly twice as much precipitation as all storms. In addition, wintertime ARs with the largest SSM/I IWV are tied to more intense storms with stronger flows and vapor fluxes, and more precipitation. ARs generally increase snow water equivalent (SWE) in autumn/winter and decrease SWE in spring. On average, wintertime SWE exhibits normal gains during north-coast AR storms and above-normal gains during the south-coast AR storms. The north-coast sites are mostly lower in altitude, where warmer-than-normal conditions more frequently yield rain. During those events when heavy rain from a warm AR storm falls on a preexisting snowpack, flooding is more likely to occur. ?? 2008 American Meteorological Society.

Investigations into the Early History of Naturally Produced Spring Chinook Salmon in the Grand Ronde Basin : Fish Research Project Oregon : Annual Progress Report Project Period September 1, 1996 to August 31, 1997.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johasson, Brian C.; Tranquilli, J. Vincent; Keefe, MaryLouise

1998-10-28

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 uppermore » 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 habitats, particularly alcove and backwater pools. These results were consistent for both summer and winter surveys.« less

Pacific Decadal Oscillation Influences Drought (June 27, 2004)

NASA Technical Reports Server (NTRS)

2004-01-01

Recent sea level height data from the U.S./France Jason altimetric satellite during a 10-day cycle ending June 27, 2004, shows that Pacific equatorial surface ocean heights and temperatures are near neutral, but perhaps tending towards a mild La Nina for this summer and into the fall. 'In the U.S. we are still under the influence of the larger than El Nino and La Nina Pacific Decadal Oscillation shift in Pacific Ocean heat content and temperature patterns.' Much of the nation's western farmland and forests are really dry as we continue to struggle with a severe 6-year drought. The reality is that the atmosphere is acting as though La Nina is present. This continuing oceanic pattern in the Pacific and atmospheric pattern over the western U.S. is also a precursor for an active hurricane season for the East and Gulf coasts for our coming summer and fall,' said JPL oceanographer Dr. Bill Patzert.

These images show sea surface height anomalies with the seasonal cycle (the effects of summer, fall, winter, and spring) removed. The differences between what we see and what is normal for different times and regions are called anomalies, or residuals. When oceanographers and climatologists view these 'anomalies' they can identify unusual patterns and can tell us how heat is being stored in the ocean to influence future planetary climate events. Each image is a 10-day average of data, ending on the date indicated.

Pacific Decadal Oscillation Influences Drought (June 15, 2004)

NASA Technical Reports Server (NTRS)

2004-01-01

Recent sea level height data from the U.S./France Jason altimetric satellite during a 10-day cycle ending June 15, 2004, shows that Pacific equatorial surface ocean heights and temperatures are near neutral, but perhaps tending towards a mild La Nina for this summer and into the fall. 'In the U.S. we are still under the influence of the larger than El Nino and La Nina Pacific Decadal Oscillation shift in Pacific Ocean heat content and temperature patterns.' Much of the nation's western farmland and forests are really dry as we continue to struggle with a severe 6-year drought. The reality is that the atmosphere is acting as though La Nina is present. This continuing oceanic pattern in the Pacific and atmospheric pattern over the western U.S. is also a precursor for an active hurricane season for the East and Gulf coasts for our coming summer and fall,' said JPL oceanographer Dr. Bill Patzert.

These images show sea surface height anomalies with the seasonal cycle (the effects of summer, fall, winter, and spring) removed. The differences between what we see and what is normal for different times and regions are called anomalies, or residuals. When oceanographers and climatologists view these 'anomalies' they can identify unusual patterns and can tell us how heat is being stored in the ocean to influence future planetary climate events. Each image is a 10-day average of data, ending on the date indicated.

Characterizing meteorological and hydrologic conditions associated with shallow landslide initiation in the coastal bluffs of the Atlantic Highlands, New Jersey

USGS Publications Warehouse

Ashland, Francis; Fiore, Alex R.; Reilly, Pamela A.; De Graff, Jerome V.; Shakoor, Abdul

2017-01-01

Meteorological and hydrologic conditions associated with shallow landslide initiation in the coastal bluffs of the Atlantic Highlands, New Jersey remain undocumented despite a history of damaging slope movement extending back to at least 1903. This study applies an empirical approach to quantify the rainfall conditions leading to shallow landsliding based on analysis of overlapping historical precipitation data and records of landslide occurrence, and uses continuous monitoring to quantify antecedent soil moisture and hydrologic response to rainfall events at two failure-prone hillslopes. Analysis of historical rainfall data reveals that both extended duration and cumulative rainfall amounts are critical characteristics of many landslide-inducing storms, and is consistent with current monitoring results that show notable increases in shallow soil moisture and pore-water pressure in continuous rainfall periods. Monitoring results show that shallow groundwater levels and soil moisture increase from annual lows in late summer-early fall to annual highs in late winter-early spring, and historical data indicate that shallow landslides occur most commonly from tropical cyclones in late summer through fall and nor’easters in spring. Based on this seasonality, we derived two provisional rainfall thresholds using a limited dataset of documented landslides and rainfall conditions for each season and storm type. A lower threshold for landslide initiation in spring corresponds with high antecedent moisture conditions, and higher rainfall amounts are required to induce shallow landslides during the drier soil moisture conditions in late summer-early fall.

Global behavior of the height/seasonal structure of tides between 40 deg and 60 deg latitude

NASA Technical Reports Server (NTRS)

Manson, A. H.; Meek, C. E.; Teitelbaum, H.; Fraser, G. J.; Smith, M. J.; Clark, R. R.; Schminder, R.; Kuerschner, D.

1989-01-01

The radars utilized are meteor (2), medium frequency (2) and the new low frequency (1) systems: analysis techniques were exhaustively studied internally and comparatively and are not thought to affect the results. Emphasis is placed upon the new height-time contours of 24-, 12-h tidal amplitudes and phases, which best display height and seasonal structures; where possible high resolution (10 d) is used (Saskatoon), but all stations provide monthly mean resolution. At these latitudes the diurnal tide is generally smaller than the semidiurnal, and displays more variability. However, there is a tendency for vertical wavelengths and amplitudes to be larger during summer months. On occasions in winter and fall, wavelengths may be less than 50 km. The dominant semidiurnal tide shows significant regular season structure; wavelengths are generally small (about 50 km) in winter, large in summer (equal to or greater than 100 km), and these states are separated by rapid equinoctial transitions. There is some evidence for less regularity toward 40 deg. Coupling with mean winds is apparent. Data from earlier ATMAP campaigns are mentioned, and reasons for their inadequacies presented.

Seasonal Variations of Quantified Organic Compounds in PM10 over Seoul

NASA Astrophysics Data System (ADS)

Choi, N.; Lee, J.; Kim, Y. P.

2014-12-01

The concentrations of 87 individual organic matters in the PM10 samples, systematically collected on the roof of the School of Public Health building at Seoul National University (mixed commercial and residential area), Seoul, South Korea on a daily basis from April 2010 to April 2011, were quantified by mean of Gas Chromatography/Mass Spectrometry (GC/MS). The daily average concentrations of five organic groups, alkanes, PAHs, fatty acid, DCAs, and sugars were ranged from 498.40 ng m3 to 10.20 μg m3. The seasonal concentrations of the total quantified organic species were 1.73 μg m3 (Spring), 2.04 μg m3 (Summer), 3.11 μg m3 (Fall), and 3.60 μg m3 (Winter), respectively. All the organic groups showed higher average concentration in winter than in summer. However, some organic compounds among fatty acids, DCAs, and sugars showed reverse pattern. The seasonal concentration patterns and episode variation of individual organic compounds were studied to clarify the emission characteristics of organic matters in PM10.

Seasonal Acclimatization in Summer versus Winter to Changes in the Sweating Response during Passive Heating in Korean Young Adult Men.

PubMed

Lee, Jeong-Beom; Kim, Tae-Wook; Min, Young-Ki; Yang, Hun-Mo

2015-01-01

We investigated the sweating response during passive heating (partial submersion up to the umbilical line in 42±0.5℃ water, 30 min) after summer and winter seasonal acclimatization (SA). Testing was performed in July during the summer, 2011 [summer-SA; temp, 25.6±1.8℃; relative humidity (RH), 82.1±8.2%] and in January during the winter, 2012 (winter-SA; temp, -2.7±2.9℃; RH, 65.0±13.1%) in Cheonan (126°52'N, 33.38'E), Republic of Korea. All experiments were carried out in an automated climatic chamber (temp, 25.0±0.5℃: RH, 60.0±3.0%). Fifteen healthy men (age, 23.4±2.5 years; height, 175.0±5.9 cm; weight, 65.3±6.1 kg) participated in the study. Local sweat onset time was delayed during winter-SA compared to that after summer-SA (p< 0.001). Local sweat volume, whole body sweat volume, and evaporative loss volume decreased significantly after winter-SA compared to those after summer-SA (p<0.001). Changes in basal metabolic rate increased significantly after winter-SA (p< 0.001), and tympanic temperature and mean body temperature were significantly lower after summer-SA (p<0.05). In conclusion, central sudomotor acitivity becomes sensitive to summer-SA and blunt to winter-SA in Rebubic of Korea. These results suggest that the body adjusts its temperature by economically controlling the sweating rate but does not lower the thermal dissipation rate through a more effective evaporation scheme after summer-SA than that after winter-SA.

Season affects body composition and estimation of fluid overload in haemodialysis patients: variations in body composition; a survey from the European MONDO database.

PubMed

Broers, Natascha J H; Usvyat, Len A; Marcelli, Daniele; Bayh, Inga; Scatizzi, Laura; Canaud, Bernard; van der Sande, Frank M; Kotanko, Peter; Moissl, Ulrich; Kooman, Jeroen P

2015-04-01

Seasonal variations in blood pressure (BP) and inter-dialytic weight gain (IDWG) are well established in dialysis patients. However, no study has assessed changes in body composition (BC) in this population. In this survey, seasonal variations in fat mass (FM), lean tissue mass (LTM), extracellular water (ECW) and fluid overload (FO) were assessed in 42 099 dialysis patients (mean age 61.2 years, 58% males) from the Fresenius Medical Care Europe database, as part of the MONitoring Dialysis Outcomes (MONDO) consortium, in relation to other nutritional parameters, IDWG and BP. BC was assessed by a body composition monitor (BCM®, Fresenius Medical Care, Bad Homburg, Germany). FM was highest in winter and lowest in summer (▵FM -1.17 kg; P < 0.001), whereas LTM was lowest during winter and highest in summer (▵LTM 0.86 kg; P < 0.0001). ECW and FO were lowest in winter, and highest in spring (▵ECW: 0.13 L; P < 0.0001, ▵FO: 0.31 L; P < 0.0001) and summer (▵ECW: 0.15 L; P < 0.0001 and ▵FO: 0.2 L; P < 0.0001), despite a higher systolic blood pressure (SBP; 136.7 ± 17.4 mmHg) and IDWG (3.0 ± 1.1 kg) during winter. C-reactive protein (CRP), serum sodium and haemoglobin levels were highest in winter, whereas serum albumin was lowest in fall. Normalized protein catabolic rate (nPCR) was lowest in winter and matched variations in BC only to a minor degree. BC and hydration state, assessed by bio-impedance spectroscopy, follows a seasonal pattern which may be of relevance for the estimation of target weight, and for the interpretation of longitudinal studies including estimates of BC. Whether these changes should lead to therapeutic interventions could be the focus of future studies. © The Author 2014. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Mid-Atlantic)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grimes, B.H.; Huish, M.T.; Kerby, J.H.

1989-08-01

Species profiles are literature summaries of the taxonomy, morphology, range, life history, and environmental requirements of coastal species. They are designed to assist in environmental impact assessments. The summer flounder supports an important commercial and recreational fishery in the Mid-Atlantic and are important constituent of estuarine and continental shelf systems throughout the region. Summer flounder spawning begins in September and winter flounder spawning begins in June. Summer flounder eggs are pelagic whereas winter flounder eggs are demersal. Summer flounder larvae are more abundant in inlets, and juveniles are found in estuarine seagrass beds in salinities {>=}12 ppt. Winter flounder juvenilesmore » are abundant in shallow bays and estuaries, moving seaward in spring and summer. Growth of winter flounder and summer flounder is seasonal. There are probably three spawning populations of both species which produce a complex stock pattern. Summer flounder are tolerant of a wide range of chemical and physica faactors, but prefer {gt}10 ppt salinities. Winter flounder optimal temperature is 18.5 {degree}C. Diseases of winter flounder are more prevalent in polluted waters. Summer flounder are tolerant of sediments laden with contaminants. 64 refs., 5 figs., 2 tabs.« less

Arctic Climate during Eocene Hyperthermals: Wet Summers on Ellesmere Island?

NASA Astrophysics Data System (ADS)

Greenwood, D. R.; West, C. K.; Basinger, J. F.

2012-12-01

Previous work has shown that during the late Paleocene to middle Eocene, mesothermal conditions (i.e., MAT ~12-15° C) and high precipitation (MAP > 150cm/yr) characterized Arctic climates - an Arctic rain forest. Recent analyses of Arctic Eocene wood stable isotope chemistry are consistent with the annual and seasonal temperature estimates from leaf physiognomy and nearest living relative analogy from fossil plants, including the lack of freezing winters, but is interpreted as showing that there was a summer peak in precipitation - modern analogs are best sought on the summer-wet east coasts (e.g., China, Japan, South Korea) not the winter-wet west coasts of present-day northern temperate continents (e.g., Pacific northwest of North America). Highly seasonal 'monsoon-type' summer-wet precipitation regimes (i.e., summer precip./winter precip. > 3.0) seem to characterize Eocene hyperthermal conditions in several regions of the earth, including the Arctic and Antarctic, based on both climate model sensitivity experiments and the paleoclimate proxy evidence. The leaf physiognomy proxy previously applied to estimate Arctic Paleogene precipitation was leaf area analysis (LAA), a correlation between mean leaf size in woody dicot vegetation and annual precipitation. New data from modern monsoonal sites, however demonstrates that for deciduous-dicot dominated vegetation, summer precipitation determines mean leaf size, not annual totals, and therefore that under markedly seasonal precipitation and/or light regimes that summer precipitation is being estimated using LAA. Presented here is a new analysis of a leaf macrofloras from 3 separate florules of the Margaret Formation (Split Lake, Stenkul Fiord and Strathcona Fiord) from Ellesmere Island that are placed stratigraphically as early Eocene, and likely fall within Eocene thermal maximum 1 (ETM1; = the 'PETM') or ETM2. These floras are each characterized by a mix of large-leafed and small-leafed dicot taxa, with overall mean leaf size across all leaf morphotypes comparable to that previously reported for late Paleocene to middle Eocene floras from Ellesmere and Axel Heiberg islands of Nunavut. Applying the conventional leaf area analysis to the putatively ETM1 floras yielded estimates of mean annual precipitation 100-200cm/yr, consistent with the previous reports for the late Paleocene to middle Eocene. CLAMP analysis applied to these floras yields growing season precipitation comparable to the annual precipitation estimate from leaf area analysis. These data are interpreted as reflecting high summer precipitation in the Arctic during the late Paleocene to middle Eocene, including ETM1, as precipitation in the dark polar winter months will have had no effect on leaf size while the trees were dormant, corroborating the results from Eocene wood chemistry. High summer precipitation (i.e., light-season = wettest season) in the Eocene Arctic during hyperthermals would have contributed to regional warmth.

Seasonal Variations in Color Preference.

PubMed

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

2017-08-01

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

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

PubMed Central

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 summer and winter milk are genetically similar traits and we therefore compare the regions detected in summer milk to the regions previously detected in winter milk GWAS to discover regions that explain genetic variation in both summer and winter milk. Results The GWAS of summer milk samples resulted in 51 regions associated with one or more milk fatty acids. Results are in agreement with most associations that were previously detected in a GWAS of fatty acids from winter milk samples, including eight ‘new’ regions that were not considered in the individual studies. The high correlation between the –log10(P-values) and effects of SNPs that were found significant in both GWAS imply that the effects of the SNPs were similar on winter and summer milk fatty acids. Conclusions The GWAS of fatty acids based on summer milk samples was in agreement with most of the associations detected in the GWAS of fatty acids based on winter milk samples. Associations that were in agreement between both GWAS are more likely to be involved in fatty acid synthesis compared to regions detected in only one GWAS and are therefore worthwhile to pursue in fine-mapping studies. PMID:23107417

Sixteen year variation of horizontal phase velocity and propagation direction of mesospheric and thermospheric waves in airglow images at Shigaraki, Japan

NASA Astrophysics Data System (ADS)

Takeo, D.; Shiokawa, K.; Fujinami, H.; Otsuka, Y.; Matsuda, T. S.; Ejiri, M. K.; Nakamura, T.; Yamamoto, M.

2017-08-01

We analyzed the horizontal phase velocity of gravity waves and medium-scale traveling ionospheric disturbances (MSTIDs) by using the three-dimensional fast Fourier transform method developed by Matsuda et al. (2014) for 557.7 nm (altitude: 90-100 km) and 630.0 nm (altitude: 200-300 km) airglow images obtained at Shigaraki MU Observatory (34.8°N, 136.1°E, dip angle: 49°) over ˜16 years from 16 March 1999 to 20 February 2015. The analysis of 557.7 nm airglow images shows clear seasonal variation of the propagation direction of gravity waves in the mesopause region. In spring, summer, fall, and winter, the peak directions are northeastward, northeastward, northwestward, and southwestward, respectively. The difference in east-west propagation direction between summer and winter is probably caused by the wind filtering effect due to the zonal mesospheric jet. Comparison with tropospheric reanalysis data shows that the difference in north-south propagation direction between summer and winter is caused by differences in the latitudinal location of wave sources due to convective activity in the troposphere relative to Shigaraki. The analysis of 630.0 nm airglow images shows that the propagation direction of MSTIDs is mainly southwestward with a minor northeastward component throughout the 16 years. A clear negative correlation is seen between the yearly power spectral density of MSTIDs and F10.7 solar flux. This negative correlation with solar activity may be explained by the linear growth rate of the Perkins instability and secondary wave generation of gravity waves in the thermosphere.

A 500 year seasonally resolved δ18O and δ13C, layer thickness and calcite fabric record from a speleothem deposited in equilibrium of the Han-sur-Lesse cave, Belgium

NASA Astrophysics Data System (ADS)

Van Rampelbergh, M.; Verheyden, S.; Allan, M.; Quinif, Y.; Cheng, H.; Edwards, L.; Keppens, E.; Claeys, P.

2014-10-01

Speleothem δ18O and δ13C signals have already proven to enable climate reconstructions at high resolution. However, seasonally resolved speleothem records are still scarce and often difficult to interpret in terms of climate due to the multitude of factors that can affect the proxy signals. In this paper, a fast growing (up to 2 mm yr-1) seasonally laminated speleothem from the Han-sur-Lesse cave (Belgium) is analyzed for its δ18O and δ13C values, layer thickness and changes in calcite fabric. The studied part of the speleothem covers the most recent 500 years as indicated by layer counting and confirmed by 20 U/Th-ages. Epikarst recharge occurs mainly in winter and lesser during spring and fall. a good correlation can be established between lower winter temperatures and lower winter precipitation (DJF) based on the measured data by the Belgian meteorological institute since 1833 indicating that a dry winter is also a cold winter. Colder and dryer winters cause lower winter recharge and generally drier conditions in the cave. Lower winter recharge decreases the amount of isotopically light (δ18O) winter precipitation added to the epikarst in comparison to the heavier spring and fall waters, which leads to a net increase in δ18O value of the water in the epikarst. Increased δ18O values in the Proserpine are consequently interpreted to reflect colder and dryer winters. Higher δ13C signals are interpreted to reflect increased prior calcite precipitation (PCP) due to colder and dryer winters, when recharge is lower. Thinner layers and darker calcite relate to slower growth and occur when drip rates are low and when the drip water calcium ion concentration is low due to increased PCP, both caused by lower recharge during periods with colder and dryer winters. Exceptionally cold and dry winters cause the drip discharge to decrease under a certain threshold value inducing anomalies in the measured proxy records. Such anomalies occur from 1565 to 1610, from 1770 to 1800, from 1810 to 1860 and from 1880 to 1895 and correspond with exceptionally cold periods in proxy-based, historical and instrumental records and may relate to different factors such as negative winter NAO phases, lower solar irradiance and/or volcanic eruptions. When the discharge threshold is not reached, lower amplitude variations are observed such as between 1479 and 1565 and between 1730 and 1770 with two periods of relatively warmer and wetter winters. Between 1610 and 1730 a period of relatively cooler and dryer winters occurs and may relate to a decrease in solar irradiance during the Maunder Minimum (1640-1714). Seasonal δ18O variations indicate a 2.5 °C seasonality in cave air temperature during the two periods with warmer and wetter winters (1479-1565 and 1730-1770), and correspond to the cave air temperature seasonality observed today. a smaller 1.5 °C seasonality in cave air temperature occurs during the interval with colder and wetter winters between 1610 and 1730 and suggests colder summers. The δ13C seasonal changes suggest that the seasonality in discharge was lower than the one observed today with a short interval of increased seasonality between 1600 and 1660 reflecting stronger summer PCP-effects due to decreased winter recharge.

Pacific Continental Shelf Environmental Assessment (PaCSEA): aerial seabird and marine mammal surveys off northern California, Oregon, and Washington, 2011-2012

USGS Publications Warehouse

Adams, Josh; Felis, Jonathan J.; Mason, John W.; Takekawa, John Y.

2014-01-01

Marine birds and mammals comprise an important community of meso- and upper-trophic-level predators within the northern California Current System (NCCS). The NCCS is located within one of the world’s four major eastern boundary currents and is characterized by an abundant and diverse marine ecosystem fuelled seasonally by wind-driven upwelling which supplies nutrient-rich water to abundant phytoplankton inhabiting the surface euphotic zone. The oceanographic conditions throughout the NCCS fluctuate according to well-described seasonal, inter-annual, and decadal cycles. Such oceanographic variability can influence patterns in the distribution, abundance, and habitat use among marine birds and mammals. Although there are an increasing number of studies documenting distributions and abundances among birds and mammals in various portions of the NCCS, there have been no comprehensive, large-scale, multi-seasonal surveys completed throughout this region since the early 1980s (off northern California; Briggs et al. 1987) and early 1990s (off Oregon and Washington; Bonnell et al. 1992, Briggs et al. 1992, Green et al. 1992). During 2011 and 2012, we completed the Pacific Continental Shelf Environmental Assessment (PaCSEA) which included replicated surveys over the continental shelfslope from shore to the 2000-meter (m) isobath along 32 broad-scale transects from Fort Bragg, California (39° N) through Grays Harbor, Washington (47° N). Additionally, surveys at a finer scale were conducted over the continental shelf within six designated Focal Areas: Fort Bragg, CA; Eureka, CA; Siltcoos Bank, OR; Newport, OR; Nehalem Bank, OR; and Grays Harbor, WA. We completed a total of 26,752 km of standardized, low-elevation aerial survey effort across three bathymetric domains: inner-shelf waters ( Overall, we recorded 15,403 sightings of 59,466 individual marine birds (12 families, 54 species). During winter, seven species groupings comprised >90% of the total number of birds counted (19,033) with Common Murres (Uria aalge) representing the majority of individuals counted (70.4% of total). The remaining six most abundant taxa included: Surf/White-winged Scoters (Melanitta perspicillata/M. fusca; 4.8% of total), Herring/Thayer’s Gulls (Larus argentatus/L. thayeri; 3.8% of total), Cassin’s Auklets (Ptychoramphus aleuticus; 3.8% of total), Glaucous-winged Gulls (Larus glaucescens; 3.7% of total), Black-legged Kittiwakes (Rissa tridactyla; 2.0% of total), and Western Gulls (Larus occidentalis; 1.9% of total). During summer, five species comprised >95% of the total number of birds counted (17,063) with the majority comprised of Common Murres (54.1% of total) and Sooty Shearwaters (Puffinus griseus; 34.4% of total). The remaining most abundant three taxa included: Fork-tailed Storm-Petrels (Oceanodroma furcata; 3.3% of total), Western Gulls (2.1% of total), and Leach’s Storm-Petrels (Oceanodroma leucorhoa; 1.1% of total). During fall, nine species comprised >85% of the total number of birds counted (23,376) with the majority comprised of Common Murres (50.0% of total) and Sooty Shearwaters (10.5% of total). The remaining seven taxa included Cassin’s Auklets (5.2% of total), Surf/White-winged Scoters (5.1% of total), Fork-tailed Storm-Petrels (3.8% of total), Red/Red-necked Phalaropes (Phalaropus fulicarius/P. lobatus; 3.2% of total), California Gulls (Larus californicus; 3.1% of total), Northern Fulmars (Fulmarus glacialis; 2.7% of total), and Sabine’s Gulls (Xema sabini; 2.2% of total). Throughout the entire PaCSEA survey area, average densities (± SE) at sea for all marine birds combined were similar between fall (23.7 ± 1.9 birds km-2) and winter (24.0 ± 1.9 birds km-2) and least during summer (16.3 ± 2.2 birds km-2). Marine bird densities at sea varied according to bathymetric domain and season. Throughout the entire PaCSEA study area average densities (± SE) for all marine birds combined were greatest over the inner-shelf domain (-2) and similar during winter (37.4 ± 4.6 birds km-2) and summer (37.5 ± 6.4 birds km-2). Within the outer-shelf domain (100 – 200-m depth), average densities for all marine birds combined were greatest during winter (34.6 ± 4.2 birds km-2), lesser during fall (16.2 ± 1.7 birds km-2), and least during summer (6.9 ± 1.1 birds km-2). Within the farthest offshore waters over the continental slope domain (200 – 2000-m depth) average densities for all marine birds combined were greatest during fall (10.0 ± 2.2 birds km-2) and winter (9.3 ± 1.5 birds km-2), and lesser during summer (6.2 ± 1.4 birds km-2). We observed 16 cetacean species and five pinniped species. Among the Mysticeti (baleen whales), humpback whales (Megaptera novaeangliae) were most frequently observed (114 sightings of 264 individuals) during summer and fall mostly over the outer-shelf and slope waters, however, individuals were also seen within the Siltcoos, Nehalem, Fort Bragg, and Eureka Focal Areas. We recorded 11 Odontoceti (toothed whale) species. Harbor porpoises (Phocoena phocoena) were the most frequently sighted (164 sightings of 270 individuals). Harbor porpoises were present year-round and most frequently sighted within the inner-shelf domain throughout the entire study area in all seasons. Harbor porpoises occurred in all six Focal Areas, with noteworthy aggregations within the Eureka, Siltcoos, and Grays Harbor Focal Areas. We recorded 246 sightings of 375 individual pinnipeds (5 species). California sea lions (Zalophus californianus) were the most frequently sighted and were present year-round with slightly more sightings recorded during the fall. California sea lions showed a decreasing frequency of sightings and relative abundance with distance from shore across the bathymetric domains surveyed, being most frequently observed over the inner-shelf. Northern elephant seals (Mirounga angustirostris), harbor seals (Phoca vitulina), and northern fur seals (Callorhinus ursinus) were observed occasionally during all seasons with harbor seals occurring nearshore (usually within 10 km of the coast) and northern fur seals almost exclusively beyond the shelf break (> 200-m depth), especially during winter off Oregon and Washington. Northern (Steller’s) sea lions (Eumetopias jubatus) were uncommonly sighted during winter and fall.

Upper lethal temperatures in three cold-tolerant insects are higher in winter than in summer.

PubMed

Vu, Henry M; Duman, John G

2017-08-01

Upper lethal temperatures (ULTs) of cold-adapted insect species in winter have not been previously examined. We anticipated that as the lower lethal temperatures (LLTs) decreased (by 20-30°C) with the onset of winter, the ULTs would also decrease accordingly. Consequently, given the recent increases in winter freeze-thaw cycles and warmer winters due to climate change, it became of interest to determine whether ambient temperatures during thaws were approaching ULTs during the cold seasons. However, beetle Dendroides canadensis (Coleoptera: Pyrochroidae) larvae had higher 24 and 48 h ULT 50 (the temperature at which 50% mortality occurred) in winter than in summer. The 24 and 48 h ULT 50 for D. canadensis in winter were 40.9 and 38.7°C, respectively. For D. canadensis in summer, the 24 and 48 h ULT 50 were 36.7 and 36.4°C. During the transition periods of spring and autumn, the 24 h ULT 50 was 37.3 and 38.5°C, respectively. While D. canadensis in winter had a 24 h LT 50 range between LLT and ULT of 64°C, the summer range was only 41°C. Additionally, larvae of the beetle Cucujus clavipes clavipes (Coleoptera: Cucujidae) and the cranefly Tipula trivittata (Diptera: Tipulidae) also had higher ULTs in winter than in summer. This unexpected phenomenon of increased temperature survivorship at both lower and higher temperatures in the winter compared with that in the summer has not been previously documented. With the decreased high temperature tolerance as the season progresses from winter to summer, it was observed that environmental temperatures are closest to upper lethal temperatures in spring. © 2017. Published by The Company of Biologists Ltd.

The impact of seasonal varied human activity on characteristics and sources of heavy metals in metropolitan road dusts.

PubMed

Men, Cong; Liu, Ruimin; Wang, Qingrui; Guo, Lijia; Shen, Zhenyao

2018-10-01

Due to significant human activity, road dust is becoming contaminated by heavy metals in many cities. To comprehensively investigate the variation of contamination level and sources of heavy metals in road dust, 10 heavy metals in road dust samples from Beijing, China, in both summer and winter, were evaluated by spatial analysis using geographic information system (GIS) mapping technology and the positive matrix factorization (PMF) Model. Although the concentrations of some heavy metals between summer and winter had similarities, the differences of others and spatial distributions of heavy metals between summer and winter were considerable. The mean concentrations of As, Cd, Cr, Cu, and Fe were lower in winter, while those of Hg, Mn, Ni, Pb, and Zn were higher. According to the values of the Pollution Index (PI) and Nemerow Integrated Pollution Index (NIPI), there were no obvious differences between summer and winter, but the range between different sites in winter was nearly twice that of summer. Based on the PMF model, four sources of heavy metals in the dust samples were identified. Although the types of sources were consistent, the relative contributions of each source differed between summer and winter. Non-exhaust vehicle emissions was the most important source in summer (34.47 wt%), while fuel combustion contributed the largest proportion to the total heavy metals in winter (32.40 wt%). The impact of each source also showed spatial variation different trends in summer and winter. With the alteration of seasons, intensity of human activities also changed, such as the number of tourists, energy needs for building temperature regulation, construction, and the amount of pesticides and fertilizer. That might be the reason for the variation of heavy metal concentrations and relative contribution of their sources between summer and winter. Copyright © 2018 Elsevier B.V. All rights reserved.

Seasonal changes in vitamin D status among Danish adolescent girls and elderly women: the influence of sun exposure and vitamin D intake.

PubMed

Andersen, R; Brot, C; Jakobsen, J; Mejborn, H; Mølgaard, C; Skovgaard, L T; Trolle, E; Tetens, I; Ovesen, L

2013-03-01

To determine seasonal variation in vitamin D status in healthy Caucasian adolescent girls and elderly community-dwelling women living in Denmark, and to quantify the impact of sun exposure and intake on the seasonal changes in vitamin D status. A 1-year longitudinal observational study of 54 girls (11-13 years) and 52 women (70-75 years). The participants were examined three times (winter-summer-winter). Serum 25-hydroxyvitamin D (S-25OHD) concentration and vitamin D intake were measured at each visit. Sun exposure was measured during summer. S-25OHD concentrations (winter, summer, winter) were median (25, 75 percentiles) 23.4 (16.5, 36.4), 60.3 (42.7, 67.7), 29.5 (22.2, 40.4) and 47.2 (27.3, 61.1), 67.3 (35.1, 79.2), 50.5 (32.7, 65.5)nmol/l for girls and women, respectively. The usual sun habits were determinant (P=0.002) for change in vitamin D status from winter to summer. Vitamin D intake from supplements (P<0.0001) and diet (P=0.002) were determinants for change in vitamin D status from summer to winter. Winter vitamin D status of 50 nmol/l is achievable when vitamin D status the previous summer was ≈ 100 nmol/l. If summer vitamin D status is only ≈ 60 nmol/l, vitamin D status the following winter would be ≈ 28 nmol/l. Low vitamin D status among adolescent girls and elderly women during two consecutive winter seasons, improved vitamin D status during the summer and better vitamin D status in women than in girls was found. The estimations show that a summer S-25OHD concentration ≈ 100 nmol/l is needed to achieve a concentration of ≈ 50 nmol/l the following winter.

Long-term observations of Alaska Coastal Current in the northern Gulf of Alaska

NASA Astrophysics Data System (ADS)

Stabeno, Phyllis J.; Bell, Shaun; Cheng, Wei; Danielson, Seth; Kachel, Nancy B.; Mordy, Calvin W.

2016-10-01

The Alaska Coastal Current is a continuous, well-defined system extending for 1700 km along the coast of Alaska from Seward, Alaska to Samalga Pass in the Aleutian Islands. The currents in this region are examined using data collected at >20 mooring sites and from >400 satellite-tracked drifters. While not continuous, the mooring data span a 30 year period (1984-2014). Using current meter data collected at a dozen mooring sites spread over four lines (Seward, Gore Point, Kennedy and Stevenson Entrances, and the exit to Shelikof Strait) total transport was calculated. Transport was significantly correlated with alongshore winds, although the correlation at the Seward Line was weak. The largest mean transport in the Alaska Coastal Current occurred at Gore Point (1.4×106 m3 s-1 in winter and 0.6×106 m3 s-1 in summer), with the transport at the exit to Shelikof Strait (1.3×106 m3 s-1 in winter and 0.6×106 m3 s-1 in summer) only slightly less. The transport was modified at the Seward Line in late summer and fall by frontal undulations associated with strong river discharge that enters onto the shelf at that time of year. The interaction of the Alaska Coastal Current and tidal currents with shallow banks in the vicinity of Kodiak Archipeligo and in Kennedy-Stevenson Entrance results in mixing and prolonged primary production throughout the summer.

Mortality risk factors during the 1918-1919 influenza pandemic in the Australian army.

PubMed

Shanks, G Dennis; Mackenzie, Alison; McLaughlin, Ruth; Waller, Michael; Dennis, Peter; Lee, Seung-Eun; Brundage, John F

2010-06-15

Understanding the risk of mortality during the 1918-1919 influenza pandemic could inform preparations for a future pandemic. Prospectively collected demographic, hospitalization, and death data from all individuals who served in the Australian Imperial Force from 1914 through 1919 in Europe and the Middle East were abstracted from archived records. Analyses were conducted to determine mortality risk factors. Hospitalization with a respiratory illness during the spring-summer of 1918 protected soldiers from death (odds ratio, 0.37 [95% confidence interval, 0.25-0.53]; P < .001) but not from hospitalization during the fall-winter of 1918-1919. During the fall-winter of 1918-1919, there was a strong inverse relationship between risk of dying of pneumonia-influenza and time in military service. The pneumonia-influenza death rate among men who enlisted in 1918 (6.33 deaths per 100 person-years) was 9 times higher than that among the 1917 enlistment cohort (0.72 deaths per 100 person-years) and >14 times higher than that among the 1916 cohort (0.43 deaths per 100 person-years), 1915 cohort (0.29 deaths per 100 person-years), and 1914 cohort (0.28 deaths per 100 person-years). There was a strong inverse relationship between length of service in the Australian Imperial Force and mortality risk from pneumonia-influenza during the fall-winter of 1918-1919. The protective effect of increased service likely reflected increased acquired immunity to influenza viruses and endemic bacterial strains that caused secondary pneumonia and most of the deaths during the 1918-1919 influenza pandemic.

An experimental field evaluation of winter carryover effects in semi-anadromous brown trout (Salmo trutta).

PubMed

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.

[Impacts on the life quality of the patients with allergic rhinitis treated with warming acupuncture in winter and summer].

PubMed

Xie, Yilin; Wan, Wenrong; Zhao, Yinlong; Ye, Zhiying; Chen, Huiyang; Hong, Xiuyu; Wu, Lei; Wang, Ruiwen; Yang, Jingui

2015-12-01

To explore the impacts on the life quality and the effect mechanism in the patients of allergic rhinitis (AR) treated with warm acupuncture in winter and summer. Two hundred and forty patients of AR were randomized into a summer and winter acupuncture group, a non-summer and winter acupuncture group and a western medication group, 80 cases in each one. In the two acupuncture groups, Dazhui (GV 14), Fengmen (BL 12), Feishu (BL 13), Pishu (BL 20) and Shenshu (BL 23) were selected. In the summer and winter acupuncture group, the warm acupuncture started at the first day of the three periods of hot season and the first day of the third nine-day period after the winter solstice. The treatment was given once every two days, continuously for 15 times. Totally, 30 treatments were required a year. In the non-summer and winter acupuncture group, the warm acupuncture was applied out of the three periods of the hot season and the third nine-day period after the winter solstice. The treatment was given once every two days and 30 treatments for a year. In the western medication group, cetirizine was taken orally, continuously for 30 days as one session. In the three groups, the treatment for 1 year was taken as one session. The second session started in the next year. Totally, 2 sessions were required. The score of rhinoconjunctivitis quality of life questionnaire (RQLQ) and the level of serum immunoglobulin E (IgE) were compared in the patients' of each group before treatment and in 1 and 2 sessions of treatment. After treatment, the scores of 7 domains, named activities, common complaints, practical problems, sleep, ocular symptoms, nasal symptoms and emotions were all improved as compared with those before treatment, in the patients of the three groups (all P < 0.05). After 2 sessions treatment, the results in the summer and winter acupuncture group were better than those in the other two groups (all P < 0.05), and the results in the non-summer and winter acupuncture group were better than those in the western medication group (all P < 0.05). After treatment, serum IgE level was lower averagely than that before treatment in the three groups (all P < 0.05). After 2 sessions treatment, the result in the summer and winter acupuncture group was lower than that in the other two groups (both P < 0.05), and the result in the non-summer and winter acupuncture group was lower than that in the western medication group (P < 0.05). After treatment, the total effective rate was 92.3% (72/78) in the summer and winter acupuncture group, better than 80.5% (62/77) in the non-summer and winter acupuncture group and 69.7% (53/76) in the western medication group (both P < 0.05). The warm acupuncture in both summer and winter achieves the definite efficacy on AR and the effect mechanism is relevant with reducing serum IgE level.

Summer and winter habitat suitability of Marco Polo argali in southeastern Tajikistan: A modeling approach.

PubMed

Salas, Eric Ariel L; Valdez, Raul; Michel, Stefan

2017-11-01

We modeled summer and winter habitat suitability of Marco Polo argali in the Pamir Mountains in southeastern Tajikistan using these statistical algorithms: Generalized Linear Model, Random Forest, Boosted Regression Tree, Maxent, and Multivariate Adaptive Regression Splines. Using sheep occurrence data collected from 2009 to 2015 and a set of selected habitat predictors, we produced summer and winter habitat suitability maps and determined the important habitat suitability predictors for both seasons. Our results demonstrated that argali selected proximity to riparian areas and greenness as the two most relevant variables for summer, and the degree of slope (gentler slopes between 0° to 20°) and Landsat temperature band for winter. The terrain roughness was also among the most important variables in summer and winter models. Aspect was only significant for winter habitat, with argali preferring south-facing mountain slopes. We evaluated various measures of model performance such as the Area Under the Curve (AUC) and the True Skill Statistic (TSS). Comparing the five algorithms, the AUC scored highest for Boosted Regression Tree in summer (AUC = 0.94) and winter model runs (AUC = 0.94). In contrast, Random Forest underperformed in both model runs.

Risk of Interval Cancer in Fecal Immunochemical Test Screening Significantly Higher During the Summer Months: Results from the National Cancer Screening Program in Korea.

PubMed

Cha, Jae Myung; Suh, Mina; Kwak, Min Seob; Sung, Na Young; Choi, Kui Son; Park, Boyoung; Jun, Jae Kwan; Hwang, Sang-Hyun; Lee, Do-Hoon; Kim, Byung Chang; Lee, You Kyoung; Han, Dong Soo

2018-04-01

This study aimed to evaluate the impact of seasonal variations in climate on the performance of the fecal immunochemical test (FIT) in screening for colorectal cancer in the National Cancer Screening Program in Korea. Data were extracted from the National Cancer Screening Program databases for participants who underwent FIT between 2009 and 2010. We compared positivity rates, cancer detection rates, interval cancer rates, positive predictive value, sensitivity, and specificity for FIT during the spring, summer, fall, and winter seasons in Korea. In total, 4,788,104 FIT results were analyzed. FIT positivity rate was lowest during the summer months. In the summer, the positive predictive value of FIT was about 1.1 times (adjusted odds ratio (aOR) 1.08, 95% confidence interval (CI) 1.00-1.16) higher in the overall FIT group and about 1.3 times (aOR 1.29, 95% CI 1.10-1.50) higher in the quantitative FIT group, compared to those in the other seasons. Cancer detection rates, however, were similar regardless of season. Interval cancer risk was significantly higher in the summer for both the overall FIT group (aOR 1.16, 95% CI 1.07-1.27) and the quantitative FIT group (aOR 1.31, 95% CI 1.12-1.52). In addition, interval cancers in the rectum and distal colon were more frequently detected in the summer and autumn than in the winter. The positivity rate of FIT was lower in the summer, and the performance of the FIT screening program was influenced by seasonal variations in Korea. These results suggest that more efforts to reduce interval cancer during the summer are needed in population-based screening programs using FIT, particularly in countries with high ambient temperatures.

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

NASA Astrophysics Data System (ADS)

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.

The effect of climate manipulations on the herbivory of the pest slug Deroceras reticulatum (Müller, 1774) (Pulmonata: Agriolimacidae)

NASA Astrophysics Data System (ADS)

El-Danasoury, H.; Iglesias-Piñeiro, J.; Córdoba, M.

2016-10-01

The pestiferous status of the terrestrial slug Deroceras reticulatum and the strong dependence of its biology and ecology on climatic factors have driven research on the potential responses of the slug to predicted scenarios of climate change. Here, we report two short-term experiments performed outdoors, under seminatural conditions, to assess the behavioural response of D. reticulatum to different climate manipulations in terms of herbivory, by measuring over 7 days the damage inflicted by slug populations to lettuce seedlings. The climate manipulations tested emulate predicted climatic conditions for northwest Spain, specifically winter warming and increased summer rainfall, in contrast respectively with normal winter conditions and summer without rain conditions. In a winter experiment, we compared a normal winter treatment with a winter warming treatment; with respect to the normal winter treatment, the winter warming treatment was characterised by higher temperature, lower relative humidity and the absence of rainfall. In a summer experiment, we compared a summer drought treatment with an increased summer rainfall treatment; with respect to the summer drought treatment, the increased summer rainfall treatment was characterised by the presence of rainfall, while the conditions of temperature and relative humidity were similar in both treatments. Neither winter warming nor increased summer rainfall did lead to a significant increase on the number of seedlings damaged by the slugs. However, with both treatments, we found a moderate increase on the amount of damage suffered by the seedlings. The results are discussed in the context of the potential responses of D. reticulatum to future climatic conditions.

The effect of climate manipulations on the herbivory of the pest slug Deroceras reticulatum (Müller, 1774) (Pulmonata: Agriolimacidae).

PubMed

El-Danasoury, H; Iglesias-Piñeiro, J; Córdoba, M

2016-10-01

The pestiferous status of the terrestrial slug Deroceras reticulatum and the strong dependence of its biology and ecology on climatic factors have driven research on the potential responses of the slug to predicted scenarios of climate change. Here, we report two short-term experiments performed outdoors, under seminatural conditions, to assess the behavioural response of D. reticulatum to different climate manipulations in terms of herbivory, by measuring over 7 days the damage inflicted by slug populations to lettuce seedlings. The climate manipulations tested emulate predicted climatic conditions for northwest Spain, specifically winter warming and increased summer rainfall, in contrast respectively with normal winter conditions and summer without rain conditions. In a winter experiment, we compared a normal winter treatment with a winter warming treatment; with respect to the normal winter treatment, the winter warming treatment was characterised by higher temperature, lower relative humidity and the absence of rainfall. In a summer experiment, we compared a summer drought treatment with an increased summer rainfall treatment; with respect to the summer drought treatment, the increased summer rainfall treatment was characterised by the presence of rainfall, while the conditions of temperature and relative humidity were similar in both treatments. Neither winter warming nor increased summer rainfall did lead to a significant increase on the number of seedlings damaged by the slugs. However, with both treatments, we found a moderate increase on the amount of damage suffered by the seedlings. The results are discussed in the context of the potential responses of D. reticulatum to future climatic conditions.

Condition of Euphausia crystallorophias off East Antarctica in winter in comparison to other seasons

NASA Astrophysics Data System (ADS)

Nicol, S.; Virtue, P.; King, R.; Davenport, S. R.; McGaffin, A. F.; Nichols, P.

2004-08-01

Antarctic coastal krill ( Euphausia crystallorophias) were collected in Austral winter (July/August) 1999 in the Mertz Glacier polynya off the coast of East Antarctica and were compared to krill collected off East Antarctica during summer in 1996 and 2001 and spring 1999. A range of experiments and measurements were conducted to assess their relative condition in winter and summer. Krill collected in winter had pale yellow-green digestive glands, indicating some recent feeding activity. The size of the digestive glands was small relative to those of krill caught in summer. This indicates that feeding had been occurring at low levels during the collection period. Growth rates, measured using the instantaneous growth rate methodology, were close to zero in winter (range -5% to 7% per moult). This was an indication that some food had been available during the period of the moult cycle. Growth rates in spring ranged from -0.5% to +8.7% per moult and from 4% to 12% per moult in the summer. The mean length of the winter moult cycle (68 days) was considerably greater than the measured intermoult period in summer and spring (24-33 days). Lipid levels were low in winter, less than 5% of body weight, compared to summer levels of ˜15% (dry weight). Winter krill were richer in wax esters and poorer in polar lipids than specimens collected in summer. Krill in winter were lacking in C16 PUFA that are markers of the phytoplankton diet common in summer krill. Krill caught in the winter had significantly higher levels of 20:1 and 22:1 fatty acids (2.3%) and alcohols (8.1%) than krill sampled in summer (0.2%, 0%), indicating a shift to a carnivorous diet. Results from this study suggest that E. crystallorophias respond to low food abundance during the winter through metabolic and physiological processes. These processes were reflected in a decrease in growth rate and a significant increase in the intermoult period. The process of lipid utilisation and switching to a carnivorous/detrital type diet are also overwintering strategies employed by this species.

Sedimentary properties of shallow marine cores collected in June and September 2006, Hanalei Bay, Kaua‘i, Hawai‘i

USGS Publications Warehouse

Draut, Amy E.; Bothner, Michael H.; Reynolds, Richard L.; Buchan, Olivia C.; Cochran, Susan A.; Casso, Michael A.; Baldwin, Sandra M.; Goldstein, Harland L.; Xiao, Jiang; Field, Michael E.; Logan, Joshua B.

2007-01-01

Sedimentary facies, short-lived isotopes 7Be, 137Cs, and 210Pb, and magnetic properties of sediment cores in Hanalei Bay, Kaua‘i, Hawai‘i, were used to assess sediment sources and patterns of deposition associated with seasonal flooding of the Hanalei River. Sediment cores were collected from the seafloor in June and September of 2006 to supplement similar data collected during the summer of 2005. The youngest and thickest terrigenous sediment was observed on the east side of the bay: near the Hanalei River mouth and in a bathymetric depression, known locally as the Black Hole, that acts as a temporary sediment sink. Deposits from floods that occurred between February and April 2006 left flood deposits in the eastern bay that, by June of 2006, were on the order of 10 cm thick. A flood occurred on August 7, 2006, that was smaller than floods that occurred the previous winter but was a substantial discharge event for the summer season. Deposits from the winter 2006 floods continued to dominate the sedimentary record in the eastern bay through early fall, even after the addition of newer sediment during the August 7 flood; this is consistent with the much higher sediment input of the winter floods compared with the August 7 flood. Broad variations in magnetic grain size and relative magnetite-hematite abundance in several sediment cores indicate many sources of upland terrigenous sediment. As a group, recent flood deposits show much less variation in these properties compared with older deposits, implying either that the 2006 winter–spring flood sediment originated from one or more distinct upland settings, or that substantial mixing of sediment from multiple sources occurred during transport. Sediment is most readily remobilized and advected out of the bay during winter, when oceanic conditions are energetic. In summer, wave and current measurements made concurrently with this study showed weak currents and little wave energy, indicating that sediment delivered during summer floods most likely remains in the bay until winter storms can remove it. Increased turbidity and sedimentation on corals resulting from floods of the Hanalei River could affect the sustainability of coral reefs and their many associated species. This possibility is of particular concern during summer months when wave energy is low and sediment is not readily remobilized and transported out of the bay. The timing (seasonality) and magnitude of sediment input to the coastal ocean relative to seasonal variations in wave and current energy could have significant ecological consequences for coral-reef communities in the Hawaiian Islands.

Final Environmental Assessment for the Proposed Construction and Operation of a Live Fire-Fighting Training Area at Buckley Air Force Base, Colorado

DTIC Science & Technology

2004-06-01

No. 950PAR118. This permit was originally issued on 28 August 1997, most recently reissued as of 01 July 2002, and expires 30 June 2007 (BAFB 2001...In July 2002, the CDPHE performed an inspection of stationary source emission units and determined that BAFB was in compliance with the Title V...during the winter, spring, and fall to 9.8 million gallons for the summer months, such as July . 3.11 HAZARDOUS MATERIALS AND SUBSTANCES The ROI for

Environmental Assessment for the Proposed Construction and Operation of an Outdoor Recreation Equipment Rental Facility at Buckley Air Force Base, Colorado

DTIC Science & Technology

2004-10-01

permit was originally issued on 28 August 1997, most recently reissued as of 01 July 2002, and expires 30 June 2007 (BAFB 2001). In July 2002, the...the months during winter, spring, and fall to 9.8 million gallons for the summer months, such as July . In the first quarter of FY 04, BAFB diverted...PS Form 3811, July 1999 Domestic Return Receipt UNITED STATES POSTAL SERVICE 102595-99-M-1 First-Class Mail Postage & Fees Paid USPS Permit No

Seasonal Affective Disorder

PubMed Central

Rohan, Kelly J.

2005-01-01

Seasonal affective disorder (SAD), characterized by fall/winter major depression with spring/summer remission, is a prevalent mental health problem. SAD etiology is not certain, but available models focus on neurotransmitters, hormones, circadian rhythm dysregulation, genetic polymorphisms, and psychological factors. Light therapy is established as the best available treatment for SAD. Alternative and/or supplementary approaches involving medications, cognitive-behavioral therapy, and exercise are currently being developed and evaluated. Given the complexity of the disorder, interdisciplinary research stands to make a significant contribution to advancing our understanding of SAD conceptualization and treatment. PMID:21179639

Timing of Infections in the Threespine Stickleback (Gasterosteus aculeatus) by Schistocephalus solidus in Alaska.

PubMed

Heins, D C; Eidam, D M; Baker, J A

2016-04-01

This study provides direct evidence for the timing of infections by Schistocephalus solidus in the threespine stickleback (Gasterosteus aculeatus) of south-central Alaska. Young-of-the-year fish in Cheney Lake were infected during their first summer within a few months after hatching in May-June. Infections appear to continue under ice cover on the lake during the subsequent fall and winter. Few, if any, 1-yr-old fish seemed to be infected for the first time, although 1-yr-old hosts with established parasites apparently acquired additional infections.

[Distribution characteristics and correlations of phosphorus in sediment and interstitial water of Nansi Lake, Shandong Province of East China in summer and winter].

PubMed

Li, Bao; Wang, Zhi-Qi; Wang, Qian-Suo; Cuan, Jing-Bo

2013-06-01

By using cylindrical sediment sampler and Peeper' s interstitial water sampler, the intact sediment and interstitial water were collected from different zones of Nansi Lake in Shandong Province in summer and winter. The distribution characteristics of the sediment phosphorus forms and of the phosphate (PO4(3-)-P) in interstitial water were analyzed, and their correlations were discussed. In the sediments of Nansi Lake, phosphorus was richer, and had a significant spatial differentiation, with an overall decreasing trend from north to south, which was related to the seriously polluted Northern Nansi Lake near Jining City. Among the phosphorous forms, inorganic phosphorus (IP) had the highest concentration, accounting for 52.3%-87.2% and 60.6%-88.3% of the total phosphorus (TP) in summer and winter, respectively. The TP concentrations in 5 cm surface sediment of four sub-lakes were all higher in summer than in winter, which could be related to the human activities such as exuberant aquaculture, more chemical fertilizers application around lake, and frequent tourism activities, etc. in summer. In vertical direction, the PO4(3-)-P concentration in interstitial water decreased after an initial increase in summer and winter, and was obviously higher in summer than in winter, suggesting that the phosphorous in sediment had a higher potential to release to the overlying water in summer. The organic phosphorus (OP) and IP in sediment had a significant correlation in summer but less correlation in winter, indicating that the transformation between sediment IP and OP was more active in summer than in winter. The iron and aluminum bound phosphorus (Fe/Al-P) and IP in sediment were significantly positively correlated with the PO4(3-)-P in interstitial water. In summer and winter, the average PO4(3-)-P concentration in interstitial water collected by Peeper' s interstitial water sampler was about 20%-50% higher than that collected by the conventional centrifugal method, suggesting that using Peeper' s interstitial water sampler could be more precise.

After School Centers Project. Final Reports. Winter 1968-1969; Summer 1969.

ERIC Educational Resources Information Center

Harvard Univ., Cambridge, MA. Graduate School of Education.

Two final reports, winter 1968-1969 and summer 1969, respectively describe the sixth and seventh sessions of the Cambridge School Department's After School Center Program and involving six elementary schools. Both the winter and the summer programs were designed to give disadvantaged children remedial instruction in reading and mathematics along…

Pedologic and climatic controls on Rn-222 concentrations in soil gas, Denver, Colorado

USGS Publications Warehouse

Asher-Bolinder, S.; Owen, D.E.; Schumann, R.R.

1990-01-01

Soil-gas radon concentrations are controlled seasonally by factors of climate and pedology. In a swelling soil of the semiarid Western United States, soil-gas radon concentrations at 100 cm depth increase in winter and spring due to increased emanation with higher soil moisture and the capping effect of surface water or ice. Radon concentrations in soil drop markedly through the summer and fall. The increased insolation of spring and summer warms and dries the soil, limiting the amount of water that reaches 100 cm. Probable controls on the distribution of uranium within the soil column include its downward leaching, its precipitation or adsorption onto B-horizon clays, concretions, or cement, and the uranium content and mineralogy of the soil's granitic and gneissic precursors. -from Authors

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

PubMed

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.

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.

PubMed

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.

Southwestern willow flycatchers recaptured at wintering sites in Costa Rica

USGS Publications Warehouse

Koronkiewicz, Thomas J.; Sogge, Mark K.

2001-01-01

An adult Southwestern Willow Flycatcher banded in summer 1998 at Ash Meadows National Wildlife Refuge, Nevada, was recaptured the following winter in Santa Cruz, Costa Rica, then relocated at Ash Meadows during the 1999 breeding season. Another Southwestern Willow Flycatcher banded in 1999 as a nestling at Roosevelt Lake, Arizona, was recaptured in January 2000 on its wintering grounds in Bolsen, Costa Rica. The bird was recaptured at Roosevelt Lake in summer 2000, returned to the same wintering site in Bolsen the following winter, and was relocated at Roosevelt Lake in summer 2001.

Risk of Fall-Related Injury due to Adverse Weather Events, Philadelphia, Pennsylvania, 2006-2011.

PubMed

Gevitz, Kathryn; Madera, Robbie; Newbern, Claire; Lojo, José; Johnson, Caroline C

Following a surge in fall-related visits to local hospital emergency departments (EDs) after a severe ice storm, the Philadelphia Department of Public Health examined the association between inclement winter weather events and fall-related ED visits during a 5-year period. Using a standardized set of keywords, we identified fall-related injuries in ED chief complaint logs submitted as part of Philadelphia Department of Public Health's syndromic surveillance from December 2006 through March 2011. We compared days when falls exceeded the winter fall threshold (ie, "high-fall days") with control days within the same winter season. We then conducted matched case-control analysis to identify weather and patient characteristics related to increased fall-related ED visits. Fifteen high-fall days occurred during winter months in the 5-year period. In multivariable analysis, 18- to 64-year-olds were twice as likely to receive ED care for fall-related injuries on high-fall days than on control days. The crude odds of ED visits occurring from 7:00 am to 10:59 am were 70% higher on high-fall days vs control days. Snow was a predictor of a high-fall day: the adjusted odds of snow before a high-fall day as compared with snow before a control day was 13.4. The association between the number of fall-related ED visits and weather-related fall injuries, age, and timing suggests that many events occurred en route to work in the morning. Promoting work closures or delaying openings after severe winter weather would allow time for better snow or ice removal, and including "fall risk" in winter weather advisories might effectively warn morning commuters. Both strategies could help reduce the number of weather-related fall injuries.

To everything there is a season: impact of seasonal change on admissions, acuity of injury, length of stay, throughput, and charges at an accredited, regional burn center.

PubMed

Hultman, C Scott; Tong, Winnie T; Surrusco, Matthew; Roden, Katherine S; Kiser, Michelle; Cairns, Bruce A

2012-07-01

Although previous studies have investigated the impact of weather and temporal factors on incidence of trauma admissions, there is a paucity of data describing the effect of seasonal change on burn injury. The purpose of this study was to examine the impact of the changing seasons on admissions to and resource utilization at an accredited burn center, with the goal of optimizing patient throughput and matching supply with demand. We performed a retrospective review of all burn admissions to an accredited, regional burn center, from Summer 2009 through Spring 2010. Patients were segregated into the seasonal cohorts of Summer, Fall, Winter, and Spring, based on admission date. Patient demographics included age, gender, mechanism of injury, and total body surface area (TBSA) injured. Main outcome measures included length of intensive care unit (ICU) stay, length of stay (LOS), and hospital charges, which served as a proxy for resource utilization (nursing, wound, and critical care; access to operating room (OR); inpatient rehabilitation). Groups were compared by T tests, with statistical significance assigned to P values <0.05. Seven hundred thirty patients were admitted to the burn center during this annual period, with a mean age of 31.6 years and a TBSA of 8.9%. Although Spring had the greatest the number of admissions at 219 (30%), patients from Summer and Winter had the largest burns, longest length of ICU and hospital stays, and highest hospital charges (P < 0.05). Furthermore, variability of these parameters, as measured by standard deviation, was greatest during Summer and Winter, serving to reduce throughput via uneven demand on resources. Highest throughput occurred during the Spring, which had the highest admission-to-LOS ratio. No differences were observed in age, gender, and incidence of electrical injuries, across the 4 seasons. Summer and winter were the peak seasons of resource utilization at our burn center, in terms of length and variability of ICU and hospital stays, as well as total hospital charges. Such seasonal change may be related to acuity of burn injury but not number of burn admissions. To improve operational efficiency and maximize patient throughput, resource allocation should be structured to anticipate seasonal changes, so that supply of services matches demand.

Occurrence of antibiotic compounds in source water and finished drinking water from the upper Scioto River Basin, Ohio, 2005-6

USGS Publications Warehouse

Finnegan, Dennis P.; Simonson, Laura A.; Meyer, Michael T.

2010-01-01

The occurrence of antibiotics in surface water and groundwater in urban basins has become a topic of increasing interest in recent years. Little is known about the occurrence, fate, or transport of these compounds and the possible health effects in humans and aquatic life. The U.S. Geological Survey, in cooperation with the City of Columbus, Division of Power and Water, did a study to provide a synoptic view of the occurrence of antibiotics in source and finished waters in the upper Scioto River Basin. Water samples were collected seasonally-winter (December 2005), spring (May 2006), summer (August 2006) and fall (October 2006)-at five surface-water sites, one groundwater site, and three water-treatment plants (WTPs). Within the upper Scioto River Basin, sampling at each WTP involved two sampling sites: a source-water intake site and a finished-water site. One or more antibiotics were detected at 11 of the 12 sampling sites. Of the 49 targeted antibiotic compounds, 12 (24 percent) were detected at least one time for a total of 61 detections overall. These compounds were azithromycin, tylosin, erythromycin-H2O, erythromycin, roxithromycin, ciprofloxacin, ofloxacin, sulfamethazine, sulfamethoxazole, iso-chlorotetracycline, lincomycin, and trimethoprim. Detection results were at low levels, with an overall median of 0.014 (u or mu)g/L. Hap Cremean WTP had the fewest detections, with two source-water detections of sulfamethoxazole and azithromycin and no detections in the finished water. Of the total of 61 detections, 31 were in the winter sample run. Sulfamethoxazale and azithromycin detections represent 41 percent of all antibiotic detections. Azithromycin was detected only in the winter sample. Some antibiotics, such as those in the quinoline and tetracycline families, dissipate more quickly in warm water, which may explain why they were detected in the cool months (winter, spring, and fall) and not in the summer. Antibiotic data collected during this study were compared to antibiotic data collected in previous national, regional, and local studies. Many of the same antibiotic compounds detected in the upper Scioto River Basin also were detected in those investigations.

Effect of Irrigation to Winter Wheat on the Radiation Use Efficiency and Yield of Summer Maize in a Double Cropping System

PubMed Central

Quanqi, Li; Yuhai, Chen; Xunbo, Zhou; Songlie, Yu; Changcheng, Guo

2012-01-01

In north China, double cropping of winter wheat and summer maize is a widely adopted agricultural practice, and irrigation is required to obtain a high yield from winter wheat, which results in rapid aquifer depletion. In this experiment conducted in 2001-2002, 2002-2003, and 2004-2005, we studied the effects of irrigation regimes during specific winter wheat growing stage with winter wheat and summer maize double cropping systems; we measured soil moisture before sowing (SMBS), the photosynthetic active radiation (PAR) capture ratio, grain yield, and the radiation use efficiency (RUE) of summer maize. During the winter wheat growing season, irrigation was applied at the jointing, heading, or milking stage, respectively. The results showed that increased amounts of irrigation and irrigation later in the winter wheat growing season improved SMBS for summer maize. The PAR capture ratio significantly (LSD, P < 0.05) increased with increased SMBS, primarily in the 3 spikes leaves. With improved SMBS, both the grain yield and RUE increased in all the treatments. These results indicate that winter wheat should be irrigated in later stages to achieve reasonable grain yield for both crops. PMID:22654613

Spatial and temporal variation in daily temperature indices in summer and winter seasons over India (1969-2012)

NASA Astrophysics Data System (ADS)

Kumar, Naresh; Jaswal, A. K.; Mohapatra, M.; Kore, P. A.

2017-08-01

Spatial and temporal variations in summer and winter extreme temperature indices are studied by using daily maximum and minimum temperatures data from 227 surface meteorological stations well distributed over India for the period 1969-2012. For this purpose, time series for six extreme temperature indices namely, hot days (HD), very hot days (VHD), extremely hot days (EHD), cold nights (CN), very cold nights (VCN), and extremely cold nights (ECN) are calculated for all the stations. In addition, time series for mean extreme temperature indices of summer and winter seasons are also analyzed. Study reveals high variability in spatial distribution of threshold temperatures of extreme temperature indices over the country. In general, increasing trends are observed in summer hot days indices and decreasing trends in winter cold night indices over most parts of the country. The results obtained in this study indicate warming in summer maximum and winter minimum temperatures over India. Averaged over India, trends in summer hot days indices HD, VHD, and EHD are significantly increasing (+1.0, +0.64, and +0.32 days/decade, respectively) and winter cold night indices CN, VCN, and ECN are significantly decreasing (-0.93, -0.47, and -0.15 days/decade, respectively). Also, it is observed that the impact of extreme temperature is higher along the west coast for summer and east coast for winter.

Winter and summer home ranges of American White Pelicans (Pelecanus erythrorhynchos) captured at loafing sites in the southeastern United States

USGS Publications Warehouse

King, D. Tommy; Fischer, Justin W.; Strickland, Bronson K.; Walter, W. David; Cunningham, Fred L.; Wang, Guiming

2016-01-01

Satellite telemetry was used to investigate summer and winter home ranges for resident and migrant American White Pelicans (Pelecanus erythrorhynchos) captured in the southeastern United States between 2002 and 2007. Home range utilization distributions were calculated using 50% and 95% kernel density estimators with the plug-in bandwidth selector. Mean summer home ranges (95%) varied from 177 to 4,710 km2 and mean winter home ranges (95%) ranged from 185 to 916 km2. Mean 50% and 95% home ranges of adult American White Pelicans during summer tended to be larger than those during winter, whereas mean 50% and 95% home ranges of immature pelicans during summer tended to be smaller than those during winter. Home ranges for all American White Pelicans encompassed the latitude range of 24°–55° N, including wintering, stop over, and nesting habitat. These data provide baseline movement and home range data for future studies of American White Pelican ecology.

Do Peatlands Hibernate?

NASA Astrophysics Data System (ADS)

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. Altogether, our data indicate that peatlands are active in winter. However, a continuous snow cover is crucial for ecosystem processes both in winter and in the subsequent summer and a reduction of snow thickness or duration due to climate change may impact on peatland ecosystem functioning at various levels.

Striking Seasonality in the Secular Warming of the Northern Continents: Structure and Mechanisms

NASA Astrophysics Data System (ADS)

Nigam, S.; Thomas, N. P.

2017-12-01

The linear trend in twentieth-century surface air temperature (SAT)—a key secular warming signal— exhibits striking seasonal variations over Northern Hemisphere continents; SAT trends are pronounced in winter and spring but notably weaker in summer and fall. The SAT trends in historical twentieth-century climate simulations informing the Intergovernmental Panel for Climate Change's Fifth Assessment show varied (and often unrealistic) strength and structure, and markedly weaker seasonal variation. The large intra-ensemble spread of winter SAT trends in some historical simulations was surprising, especially in the context of century-long linear trends, with implications for the detection of the secular warming signal. The striking seasonality of observed secular warming over northern continents warrants an explanation and the representation of related processes in climate models. Here, the seasonality of SAT trends over North America is shown to result from land surface-hydroclimate interactions and, to an extent, also from the secular change in low-level atmospheric circulation and related thermal advection. It is argued that the winter dormancy and summer vigor of the hydrologic cycle over middle- to high-latitude continents permit different responses to the additional incident radiative energy from increasing greenhouse gas concentrations. The seasonal cycle of climate, despite its monotony, provides an expanded phase space for the exposition of the dynamical and thermodynamical processes generating secular warming, and an exceptional cost-effective opportunity for benchmarking climate projection models.

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

NASA Astrophysics Data System (ADS)

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.

Seasonal variability of the Red Sea, from satellite gravity, radar altimetry, and in situ observations

NASA Astrophysics Data System (ADS)

Wahr, John; Smeed, David A.; Leuliette, Eric; Swenson, Sean

2014-08-01

Seasonal variations of sea surface height (SSH) and mass within the Red Sea are caused mostly by exchange of heat with the atmosphere and by flow through the strait opening into the Gulf of Aden to the south. That flow involves a net mass transfer into the Red Sea during fall and out during spring, though in summer there is an influx of cool water at intermediate depths. Thus, summer water in the south is warmer near the surface due to higher air temperatures, but cooler at intermediate depths. Summer water in the north experiences warming by air-sea exchange only. The temperature affects water density, which impacts SSH but has no effect on mass. We study this seasonal cycle by combining GRACE mass estimates, altimeter SSH measurements, and steric contributions derived from the World Ocean Atlas temperature climatology. Among our conclusions are: mass contributions are much larger than steric contributions; the mass is largest in winter, consistent with winds pushing water into the Red Sea in fall and out during spring; the steric signal is largest in summer, consistent with surface warming; and the cool, intermediate-depth water flowing into the Red Sea in spring has little impact on the steric signal, because contributions from the lowered temperature are offset by effects of decreased salinity. The results suggest that the combined use of altimeter and GRACE measurements can provide a useful alternative to in situ data for monitoring the steric signal.

Space and habitat use by black bears in the Elwha valley prior to dam removal

USGS Publications Warehouse

Sager-Fradkin, K.A.; Jenkins, K.J.; Happe, P.J.; Beecham, J.J.; Wright, R.G.; Hoffman, R.A.

2008-01-01

Dam removal and subsequent restoration of salmon to the Elwha River is expected to cause a shift in nutrient dynamics within the watershed. To document how this influx of nutrients and energy may affect black bear (Ursus americanus) ecology, we used radio-telemetry to record movements of 11 male and two female black bears in the Elwha Valley from 2002-06. Our objective was to collect baseline data on bear movements prior to dam removal. We calculated annual home ranges, described seasonal timing of den entry and emergence, and described seasonal patterns of distribution and habitat use. Adaptive kernel home ranges were larger formales (mean = 151.1 km2, SE = 21.4) than females (mean = 38.8 km2, SE = 13.0). Males ranged widely and frequently left the watershed during late summer. Further, they exhibited predictable and synchronous patterns of elevation change throughout each year. Bears entered their winter dens between 8 October and 15 December and emerged from dens between 10 March and 9 May. Male bears used low-elevation conifer and hardwood forests along the Elwha floodplain during spring, mid- to high-elevation forests and meadows during early summer, high-elevation forests, meadows and shrubs during late summer, and mid-elevation forests, shrubs and meadows during fall. Data acquired during this study provide important baseline information for comparison after dam removal, when bears may alter their late summer and fall movement and denning patterns to take advantage of energy-rich spawning salmon.

Seasonal and pulsatile dynamics of thyrotropin and leptin in mares maintained under a constant energy balance.

PubMed

Buff, P R; Messer, N T; Cogswell, A M; Johnson, P J; Keisler, D H; Ganjam, V K

2007-11-01

The objective of this study was to determine if seasonal and/or pulsatile variations occur in plasma concentrations of thyrotropin (TSH) and leptin in mares while maintaining a constant energy balance. Blood samples were collected every 20 min during a 24h period in winter and again in summer from six Quarter Horse type mares. Plasma concentrations of TSH, leptin, and T(4) were determined by radioimmunoassay. No differences were observed in body weight between winter (388.1+/-12.5 kg) and summer (406.2+/-12.5 kg; P=0.11). Plasma concentrations of TSH were greater in the summer (2.80+/-0.07 ng/ml) when compared to winter (0.97+/-0.07 ng/ml; P<0.001). Pulse frequency of TSH was not different between winter (6.17+/-0.78 pulses/24h) and summer (5.33+/-0.78 pulses/24h; P=0.49). Mean TSH pulse amplitude, pulse area, and area under the curve were all greater in summer compared to winter (3.11+/-0.10 ng/ml versus 1.20+/-0.10 ng/ml, 24.86+/-0.10 ng/ml min versus 13.46+/-1.90 ng/ml min, 3936+/-72.93 ng/ml versus 1284+/-72.93 ng/ml, respectively; P<0.01). Mean concentrations of leptin were greater in summer (2.48+/-0.17 ng/ml) compared to winter (0.65+/-0.17 ng/ml; P<0.001). Pulsatile secretion patterns of leptin were not observed in any horses during experimentation. Mean concentrations of T(4) were greater in winter (20.3+/-0.4 ng/ml) compared to summer (18.2+/-0.4 ng/ml; P<0.001). These seasonal differences between winter and summer provide evidence of possible seasonal regulation of TSH and leptin.

Sociodemographic profile of an Olympic team.

PubMed

Lawrence, D W

2017-07-01

To document the distribution of sociodemographic markers (race and relative access to wealth) in athletes participating at the summer and Winter Olympic Games (OGs). Cross-sectional descriptive epidemiological study. Sociodemographic data were collected from publically available resources for all athletes representing four countries (Canada, United States of America, Great Britain and Australia) at the 2014 Sochi Winter OGs and 2016 Rio Summer OGs. The prevalence of white and privately educated athletes were identified for each sport, country, and team with consideration and comparison to the general population. Access indices (i.e. the combined race socio-economic access index [CAI]) were developed to describe the relative distribution of white and privately educated athletes representing each sport, country and team compared to the respective general population. A total of 568 winter and 1643 summer athletes were included in this study. Privately educated athletes constituted 30.3% and 32.7% of winter and summer athletes, respectively; while 94.9% of winter and 81.7% of summer athletes were white. The CAIs of the Canadian, American, British and Australian winter Olympic teams were 0.52, 0.42, 0.61 and 0.45, respectively. The CAIs, for the Canadian, American, British and Australian summer Olympic teams were 0.89, 1.13, 0.82 and 0.83, respectively. Summer and winter sports with the greatest and least racial and socio-economic biases were identified. Racial and socio-economic biases were identified in both summer and winter Olympic sports; predominantly favouring white and privately educated Olympic athletes. These findings prompt further inquiry into barriers for sport-specific participation and advancement, in addition to the practice of providing substantial public resources in support for Olympic sports and athletes. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Vitamin D intake needed to maintain target serum 25-hydroxyvitamin D concentrations in participants with low sun exposure and dark skin pigmentation is substantially higher than current recommendations.

PubMed

Hall, Laura M; Kimlin, Michael G; Aronov, Pavel A; Hammock, Bruce D; Slusser, James R; Woodhouse, Leslie R; Stephensen, Charles B

2010-03-01

Cutaneous cholecalciferol synthesis has not been considered in making recommendations for vitamin D intake. Our objective was to model the effects of sun exposure, vitamin D intake, and skin reflectance (pigmentation) on serum 25-hydroxyvitamin D (25[OH]D) in young adults with a wide range of skin reflectance and sun exposure. Four cohorts of participants (n = 72 total) were studied for 7-8 wk in the fall, winter, spring, and summer in Davis, CA [38.5 degrees N, 121.7 degrees W, Elev. 49 ft (15 m)]. Skin reflectance was measured using a spectrophotometer, vitamin D intake using food records, and sun exposure using polysulfone dosimeter badges. A multiple regression model (R(2) = 0.55; P < 0.0001) was developed and used to predict the serum 25(OH)D concentration for participants with low [median for African ancestry (AA)] and high [median for European ancestry (EA)] skin reflectance and with low [20th percentile, approximately 20 min/d, approximately 18% body surface area (BSA) exposed] and high (80th percentile, approximately 90 min/d, approximately 35% BSA exposed) sun exposure, assuming an intake of 200 iu/d (5 ug/d). Predicted serum 25(OH)D concentrations for AA individuals with low and high sun exposure in the winter were 24 and 42 nmol/L and in the summer were 40 and 60 nmol/L. Corresponding values for EA individuals were 35 and 60 nmol/L in the winter and in the summer were 58 and 85 nmol/L. To achieve 25(OH)D > or =75 nmol/L, we estimate that EA individuals with high sun exposure need 1300 iu/d vitamin D intake in the winter and AA individuals with low sun exposure need 2100-3100 iu/d year-round.

Isolating the Liquid Cloud Response to Recent Arctic Sea Ice Variability Using Spaceborne Lidar Observations

NASA Astrophysics Data System (ADS)

Morrison, A. L.; Kay, J. E.; Chepfer, H.; Guzman, R.; Yettella, V.

2018-01-01

While the radiative influence of clouds on Arctic sea ice is known, the influence of sea ice cover on Arctic clouds is challenging to detect, separate from atmospheric circulation, and attribute to human activities. Providing observational constraints on the two-way relationship between sea ice cover and Arctic clouds is important for predicting the rate of future sea ice loss. Here we use 8 years of CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) spaceborne lidar observations from 2008 to 2015 to analyze Arctic cloud profiles over sea ice and over open water. Using a novel surface mask to restrict our analysis to where sea ice concentration varies, we isolate the influence of sea ice cover on Arctic Ocean clouds. The study focuses on clouds containing liquid water because liquid-containing clouds are the most important cloud type for radiative fluxes and therefore for sea ice melt and growth. Summer is the only season with no observed cloud response to sea ice cover variability: liquid cloud profiles are nearly identical over sea ice and over open water. These results suggest that shortwave summer cloud feedbacks do not slow long-term summer sea ice loss. In contrast, more liquid clouds are observed over open water than over sea ice in the winter, spring, and fall in the 8 year mean and in each individual year. Observed fall sea ice loss cannot be explained by natural variability alone, which suggests that observed increases in fall Arctic cloud cover over newly open water are linked to human activities.

Ecology under lake ice.

PubMed

Hampton, Stephanie E; Galloway, Aaron W E; Powers, Stephen M; Ozersky, Ted; Woo, Kara H; Batt, Ryan D; Labou, Stephanie G; O'Reilly, Catherine M; Sharma, Sapna; Lottig, Noah R; Stanley, Emily H; North, Rebecca L; Stockwell, Jason D; Adrian, Rita; Weyhenmeyer, Gesa A; Arvola, Lauri; Baulch, Helen M; Bertani, Isabella; Bowman, Larry L; Carey, Cayelan C; Catalan, Jordi; Colom-Montero, William; Domine, Leah M; Felip, Marisol; Granados, Ignacio; Gries, Corinna; Grossart, Hans-Peter; Haberman, Juta; Haldna, Marina; Hayden, Brian; Higgins, Scott N; Jolley, Jeff C; Kahilainen, Kimmo K; Kaup, Enn; Kehoe, Michael J; MacIntyre, Sally; Mackay, Anson W; Mariash, Heather L; McKay, Robert M; Nixdorf, Brigitte; Nõges, Peeter; Nõges, Tiina; Palmer, Michelle; Pierson, Don C; Post, David M; Pruett, Matthew J; Rautio, Milla; Read, Jordan S; Roberts, Sarah L; Rücker, Jacqueline; Sadro, Steven; Silow, Eugene A; Smith, Derek E; Sterner, Robert W; Swann, George E A; Timofeyev, Maxim A; Toro, Manuel; Twiss, Michael R; Vogt, Richard J; Watson, Susan B; Whiteford, Erika J; Xenopoulos, Marguerite A

2017-01-01

Winter conditions are rapidly changing in temperate ecosystems, particularly for those that experience periods of snow and ice cover. Relatively little is known of winter ecology in these systems, due to a historical research focus on summer 'growing seasons'. We executed the first global quantitative synthesis on under-ice lake ecology, including 36 abiotic and biotic variables from 42 research groups and 101 lakes, examining seasonal differences and connections as well as how seasonal differences vary with geophysical factors. Plankton were more abundant under ice than expected; mean winter values were 43.2% of summer values for chlorophyll a, 15.8% of summer phytoplankton biovolume and 25.3% of summer zooplankton density. Dissolved nitrogen concentrations were typically higher during winter, and these differences were exaggerated in smaller lakes. Lake size also influenced winter-summer patterns for dissolved organic carbon (DOC), with higher winter DOC in smaller lakes. At coarse levels of taxonomic aggregation, phytoplankton and zooplankton community composition showed few systematic differences between seasons, although literature suggests that seasonal differences are frequently lake-specific, species-specific, or occur at the level of functional group. Within the subset of lakes that had longer time series, winter influenced the subsequent summer for some nutrient variables and zooplankton biomass. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Effect of seasonality and Cr(VI) on starch-sucrose partitioning and related enzymes in floating leaves of Salvinia minima.

PubMed

Rosa, Mariana; Prado, Carolina; Chocobar-Ponce, Silvana; Pagano, Eduardo; Prado, Fernando

2017-09-01

Effects of seasonality and increasing Cr(VI) concentrations on leaf starch-sucrose partitioning, sucrose- and starch-related enzyme activities, and carbon allocation toward leaf development were analyzed in fronds (floating leaves) of the floating fern Salvinia minima. Carbohydrates and enzyme activities of Cr-exposed fronds showed different patterns in winter and summer. Total soluble sugars, starch, glucose and fructose increased in winter fronds, while sucrose was higher in summer ones. Starch and soluble carbohydrates, except glucose, increased under increasing Cr(VI) concentrations in winter fronds, while in summer ones only sucrose increased under Cr(VI) treatment. In summer fronds starch, total soluble sugars, fructose and glucose practically stayed without changes in all assayed Cr(VI) concentrations. Enzyme activities related to starch and sucrose metabolisms (e.g. ADPGase, SPS, SS and AI) were higher in winter fronds than in summer ones. Total amylase and cFBPase activities were higher in summer fronds. Cr(VI) treatment increased enzyme activities, except ADPGase, in both winter and summer fronds but no clear pattern changes were observed. Data of this study show clearly that carbohydrate metabolism is differently perturbed by both seasonality and Cr(VI) treatment in summer and winter fronds, which affects leaf starch-sucrose partitioning and specific leaf area (SLA) in terms of carbon investment. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Connecting pigment composition and dissolved trace elements to phytoplankton population in the southern Benguela Upwelling zone (St. Helena Bay)

NASA Astrophysics Data System (ADS)

Das, Supriyo Kumar; Routh, Joyanto; Roychoudhury, Alakendra N.; Veldhuis, Marcel J. W.; Ismail, Hassan E.

2017-12-01

Rich in upwelled nutrients, the Southern Benguela is one of the most productive ecosystems in the world ocean. However, despite its ecological significance the role of trace elements influencing phytoplankton population in the Southern Benguela Upwelling System (SBUS) has not been thoroughly investigated. Here, we report pigment composition, macronutrients (nitrate, phosphate and silicate) and concentrations of dissolved Cd, Co, Fe and Zn during late austral summer and winter seasons in 2004 to understand the relationship between the selected trace elements and phytoplankton biomass in St. Helena Bay (SHB), which falls within the southern boundary of the SBUS. Chlorophyll a concentrations indicate higher phytoplankton biomass associated with high primary production during late summer in SHB where high diatom population is inferred from the presence of fucoxanthin. Diminished phytoplankton biomass and a shift from diatoms to dinoflagellates as the dominant phytoplankton taxa are indicated by diagnostic pigments during late winter. Dissolved trace elements (Cd, Co and Zn) and macronutrients play a significant role in phytoplankton biomass, and their distribution is affected by biological uptake and export of trace elements. Continuous uptake of Zn by diatoms may cause an onset of Zn depletion leading to a period of extended diatom proliferation during late summer. Furthermore, the transition from diatom to dinoflagellate dominated phytoplankton population is most likely facilitated by depletion of trace elements (Cd and Co) in the water column.

The role of the winter residual circulation in the summer mesopause regions in WACCM

NASA Astrophysics Data System (ADS)

Sanne Kuilman, Maartje; Karlsson, Bodil

2018-03-01

High winter planetary wave activity warms the summer polar mesopause via a link between the two hemispheres. Complex wave-mean-flow interactions take place on a global scale, involving sharpening and weakening of the summer zonal flow. Changes in the wind shear occasionally generate flow instabilities. Additionally, an altering zonal wind modifies the breaking of vertically propagating gravity waves. A crucial component for changes in the summer zonal flow is the equatorial temperature, as it modifies latitudinal gradients. Since several mechanisms drive variability in the summer zonal flow, it can be hard to distinguish which one is dominant. In the mechanism coined interhemispheric coupling, the mesospheric zonal flow is suggested to be a key player for how the summer polar mesosphere responds to planetary wave activity in the winter hemisphere. We here use the Whole Atmosphere Community Climate Model (WACCM) to investigate the role of the summer stratosphere in shaping the conditions of the summer polar mesosphere. Using composite analyses, we show that in the absence of an anomalous summer mesospheric temperature gradient between the equator and the polar region, weak planetary wave forcing in the winter would lead to a warming of the summer mesosphere region instead of a cooling, and vice versa. This is opposing the temperature signal of the interhemispheric coupling that takes place in the mesosphere, in which a cold and calm winter stratosphere goes together with a cold summer mesopause. We hereby strengthen the evidence that the variability in the summer mesopause region is mainly driven by changes in the summer mesosphere rather than in the summer stratosphere.

Atmospheric deposition of trace elements at urban and forest sites in central Poland - Insight into seasonal variability and sources

NASA Astrophysics Data System (ADS)

Siudek, Patrycja; Frankowski, Marcin

2017-12-01

This paper includes the results of chemical composition of bulk deposition samples collected simultaneously at urban (Poznań city) and forest (Jeziory) sites in central Poland, between April 2013 and October 2014. Rainwater samples were analyzed for trace elements (As, Zn, Ni, Pb, Cu, Cr, Cd) and physicochemical parameters. Overall, three metals, i.e. Zn, Pb and Cu were the most abundant anthropogenic constituents of rainwater samples from both locations. In Poznań city, the rainwater concentrations of trace elements did not differ significantly between spring and summer. However, they were elevated and more variable during the cold season (fall and winter), suggesting strong contribution from local high-temperature processes related to coal combustion (commercial and residential sector). In contrast to the urban site, relatively low variability in concentrations was found for Cu, Ni, Zn at the forest site, where direct impact of emission from vehicle traffic and coal-fired combustion (power plants) was much lower. The bulk deposition fluxes of Ni, As, Pb and Zn at this site exhibited a clear trend, with higher values during the cold season (fall and winter) than in spring and summer. At the urban site, the sums of total bulk deposition fluxes of Zn, Cu, Pb, Ni, As, Cr, Cd were as follows: 8460.4, 4209.2, 2247.4, 1882.1, 606.6, 281.6 and 31.4 μg m- 2. In addition, during the winter season, a significantly higher deposition fluxes of Cu and Zn were observed for rain (on average 103.8 and 129.4 μg m- 2, respectively) as compared to snow (19.7 μg Cu m- 2 and 54.1 μg Zn m- 2). This suggests that different deposition pattern of trace elements for rain, mixed and snow was probably the effect of several factors: precipitation type, changes in emission and favorable meteorological situation during rain events.

Climate influences on whitebark pine mortality from mountain pine beetle in the Greater Yellowstone Ecosystem.

PubMed

Buotte, Polly C; Hicke, Jeffrey A; Preisler, Haiganoush K; Abatzoglou, John T; Raffa, Kenneth F; Logan, Jesse A

2016-12-01

Extensive mortality of whitebark pine, beginning in the early to mid-2000s, occurred in the Greater Yellowstone Ecosystem (GYE) of the western USA, primarily from mountain pine beetle but also from other threats such as white pine blister rust. The climatic drivers of this recent mortality and the potential for future whitebark pine mortality from mountain pine beetle are not well understood, yet are important considerations in whether to list whitebark pine as a threatened or endangered species. We sought to increase the understanding of climate influences on mountain pine beetle outbreaks in whitebark pine forests, which are less well understood than in lodgepole pine, by quantifying climate-beetle relationships, analyzing climate influences during the recent outbreak, and estimating the suitability of future climate for beetle outbreaks. We developed a statistical model of the probability of whitebark pine mortality in the GYE that included temperature effects on beetle development and survival, precipitation effects on host tree condition, beetle population size, and stand characteristics. Estimated probability of whitebark pine mortality increased with higher winter minimum temperature, indicating greater beetle winter survival; higher fall temperature, indicating synchronous beetle emergence; lower two-year summer precipitation, indicating increased potential for host tree stress; increasing beetle populations; stand age; and increasing percent composition of whitebark pine within a stand. The recent outbreak occurred during a period of higher-than-normal regional winter temperatures, suitable fall temperatures, and low summer precipitation. In contrast to lodgepole pine systems, area with mortality was linked to precipitation variability even at high beetle populations. Projections from climate models indicate future climate conditions will likely provide favorable conditions for beetle outbreaks within nearly all current whitebark pine habitat in the GYE by the middle of this century. Therefore, when surviving and regenerating trees reach ages suitable for beetle attack, there is strong potential for continued whitebark pine mortality due to mountain pine beetle. © 2016 by the Ecological Society of America.

Status of alewife and rainbow smelt in U.S. waters of Lake Ontario, 2015

USGS Publications Warehouse

Walsh, Maureen; Weidel, Brian C.; Connerton, Michael J.; Holden, Jeremy P.

2016-01-01

In 2015 the joint USGS and NYSDEC surveys for Alewife and Rainbow Smelt were combined for the first time into a comprehensive spring pelagic prey fish survey. The adult Alewife abundance and weight indices in 2015 increased slightly from 2014 levels, and adult Alewife abundance has remained relatively stable for the past five years. Adult Alewife condition in both spring and fall increased from 2014 values and was above long-term means. Yearling Alewife abundance was the lowest observed in the 38-year time series. Alewife year class strength at age 1 is related to the number of spawning adults and summer temperatures and winter duration in the first year after hatching. Moderate year classes were produced during 2009-2011, and 2012 was the largest year class in the time series. However, severe winters in 2013-2014 and 2014-2015 contributed to two successive very small year classes for the first time in the time series. We expect adult Alewife abundance and biomass to decline in 2016 as older and larger fish decline in the population. The number of spawning adults increased in 2015, summer temperatures were slightly below average, and the anticipated winter duration is below average (i.e., milder winter) for 2015-2016, so these conditions will likely produce a low to moderate year class. A third successive weak year class could be problematic for the Lake Ontario Alewife population and may be of concern to binational lake managers. Rainbow Smelt were also assessed and the population continues to persist at a low and stable level.

Nitric oxide nightglow and Martian mesospheric circulation from MAVEN/IUVS observations and LMD-MGCM predictions

NASA Astrophysics Data System (ADS)

Stiepen, A.; Jain, S. K.; Schneider, N. M.; Deighan, J. I.; González-Galindo, F.; Gérard, J.-C.; Milby, Z.; Stevens, M. H.; Bougher, S.; Evans, J. S.; Stewart, A. I. F.; Chaffin, M. S.; Crismani, M.; McClintock, W. E.; Clarke, J. T.; Holsclaw, G. M.; Montmessin, F.; Lefèvre, F.; Forget, F.; Lo, D. Y.; Hubert, B.; Jakosky, B. M.

2017-05-01

We report results from a study of nitric oxide nightglow over the northern hemisphere of Mars during winter, the southern hemisphere during fall equinox, and equatorial latitudes during summer in the northern hemisphere based on observations of the δ and γ bands between 190 and 270 nm by the Imaging UltraViolet Spectrograph (IUVS) on the Mars Atmosphere and Volatile EvolutioN mission (MAVEN) spacecraft. The emission reveals recombination of N and O atoms dissociated on the dayside of Mars and transported to the nightside. We characterize the brightness (from 0.2 to 30 kR) and altitude (from 40 to 115 km) of the NO nightglow layer, as well as its topside scale height (mean of 11 km). We show the possible impact of atmospheric waves forcing longitudinal variability, associated with an increased brightness by a factor of 3 in the 140-200° longitude region in the northern hemisphere winter and in the -102° to -48° longitude region at summer. Such impact to the NO nightglow at Mars was not seen before. Quantitative comparison with calculations of the LMD-MGCM (Laboratoire de Météorologie Dynamique-Mars Global Climate Model) suggests that the model globally reproduces the trends of the NO nightglow emission and its seasonal variation and also indicates large discrepancies (up to a factor 50 fainter in the model) in northern winter at low to middle latitudes. This suggests that the predicted transport is too efficient toward the night winter pole in the thermosphere by ˜20° latitude north.

Enzymatic regulation of seasonal glycogen cycling in the freeze-tolerant wood frog, Rana sylvatica.

PubMed

do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

2016-12-01

Liver glycogen is an important energy store in vertebrates, and in the freeze-tolerant wood frog, Rana sylvatica, this carbohydrate also serves as a major source of the cryoprotectant glucose. We investigated how variation in the levels of the catalytic subunit of protein kinase A (PKAc), glycogen phosphorylase (GP), and glycogen synthase (GS) relates to seasonal glycogen cycling in a temperate (Ohioan) and subarctic (Alaskan) populations of this species. In spring, Ohioan frogs had reduced potential for glycogen synthesis, as evidenced by low GS activity and high PKAc protein levels. In addition, glycogen levels in spring were the lowest of four seasonal samples, as energy input was likely directed towards metabolism and somatic growth during this period. Near-maximal glycogen levels were reached by mid-summer, and remained unchanged in fall and winter, suggesting that glycogenesis was curtailed during this period. Ohioan frogs had a high potential for glycogenolysis and glycogenesis in winter, as evidenced by large glycogen reserves, high levels of GP and GS proteins, and high GS activity, which likely allows for rapid mobilization of cryoprotectant during freezing and replenishing of glycogen reserves during thawing. Alaskan frogs also achieved a near-maximal liver glycogen concentration by summer and displayed high glycogenic and glycogenolytic potential in winter, but, unlike Ohioan frogs, started replenishing their energy reserves early in spring. We conclude that variation in levels of both glycogenolytic and glycogenic enzymes likely happens in response to seasonal changes in energetic strategies and demands, with winter survival being a key component to understanding the regulation of glycogen cycling in this species.

Impacts of Future Climate and Emission Changes on U.S. Air Quality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penrod, Ashley; Zhang, Yang; Wang, K.

2014-06-01

Changes in climate and emissions will affect future air quality. In this work, simulations of present (2001-2005) and future (2026-2030) regional air quality are conducted with the newly released CMAQ version 5.0 to examine the individual and combined impacts of simulated future climate and anthropogenic emission projections on air quality over the U.S. Current (2001-2005) meteorological and chemical predictions are evaluated against observational data to assess the model’s capability in reproducing the seasonal differences. Overall, WRF and CMAQ perform reasonably well. Increased temperatures (up to 3.18 °C) and decreased ventilation (up to 157 m in planetary boundary layer height) aremore » found in both future winter and summer, with more prominent changes in winter. Increases in future temperatures result in increased isoprene and terpene emissions in winter and summer, driving the increase in maximum 8-h average O3 (up to 5.0 ppb) over the eastern U.S. in winter while decreases in NOx emissions drive the decrease in O3 over most of the U.S. in summer. Future concentrations of PM2.5 in winter and summer and many of its components including organic matter in winter, ammonium and nitrate in summer, and sulfate in winter and summer, decrease due to decreases in primary anthropogenic emissions and the concentrations of secondary anthropogenic pollutants and increased precipitation in winter. Future winter and summer dry and wet deposition fluxes are spatially variable and increase with increasing surface resistance and precipitation (e.g., NH4+ and NO3- dry and wet deposition fluxes increase in winter over much of the U.S.), respectively, and decrease with a decrease in ambient particulate concentrations (e.g., SO42- dry and wet deposition fluxes decrease over the eastern U.S. in summer and winter). Sensitivity simulations show that anthropogenic emission projections dominate over changes in climate in their impacts on the U.S. air quality in the near future. Changes in some regions/species, however, are dominated by climate and/or both climate and anthropogenic emissions, especially in future years that are marked by meteorological conditions conducive to poor air quality.« less

The seasonal cycle of the Lazarev Sea macrozooplankton community and a potential shift to top-down trophic control in winter

NASA Astrophysics Data System (ADS)

Hunt, B. P. V.; Pakhomov, E. A.; Siegel, V.; Strass, V.; Cisewski, B.; Bathmann, U.

2011-07-01

Between 2004 and 2008, during the German Southern Ocean GLOBEC programme, four large scale bio-oceanographic surveys were conducted in the Lazarev Sea for the Lazarev Sea Krill Survey (LAKRIS). These surveys were completed in Autumn (April-May) 2004, Summer (December-January) 2005/06, Winter (July-August) 2006, and Summer (December-January) 2007/08. On each occasion macrozooplankton communities were sampled by RMT-8 in the upper 200 m of the water column. Chlorophyll a biomass averaged ˜1.5 mg m -3 (max=8.2 mg m -3) in Summer 05/06, 0.88 mg m -3 (max=2.77 mg m -3) in Summer 07/08, 0.24 mg m -3 (max=0.73 mg m -3) in Autumn 04, and 0.042 mg m -3 (max=0.1 mg m -3) in Winter 06. Macrozooplankton densities did not differ significantly between seasons and were 53, 68, 59, and 48 ind. 1000 m -3 in Summer 05/06, Summer 07/08, Autumn, and Winter, respectively. Total macrozooplankton biomass, however, increased significantly from summer (0.88 and 0.97 g dry weight 1000 m -3 in Summer 05/06 and Summer 07/08, respectively) to Autumn 04 (2.66 g dry weight 1000 m -3) and Winter 06 levels (1.75 g dry weight 1000 m -3). This biomass increase was due to both an increased occurrence of Euphausia superba and fish and a shift to a larger size structure in the latter group. Siphonophores (predominantly Diphyes antarctica), chaetognaths (predominantly Eukrohnia hamata and Sagitta gazellae) and euphausiids (predominantly Thysanoessa macrura and E. superba) contributed >80% to total densities in all four surveys. However, a strong and distinctive change in assemblage structure was observed between seasons. Key amongst these was a shift within the euphausiids from a dominance of T. macrura in summer to that of E. superba in autumn and winter; a winter decrease in E. hamata; an autumn and winter decrease in Tomopteris sp.; and a winter increase in the abundance of the grazers Clio pyramidata sulcata and Ihlea racovitzai, hyperiids, and the myctophid fish Electrona antarctica. Carnivorous macrozooplankton formed the major trophic group in all seasons, contributing 44-60% to total macrozooplankton abundance and 39-58% to total macrozooplankton biomass in all four surveys. The combined predation pressure of carnivores and potential increased winter carnivory by E. superba and other omnivorous species, was expected to be high. In view of low winter primary production, we suggest that the epipelagic food web of the Lazarev Sea shifted from being bottom-up controlled in summer to top-down controlled in winter.

Seasonal diversity of planktonic protists in Southwestern Alberta rivers over a 1-year period as revealed by terminal restriction fragment length polymorphism and 18S rRNA gene library analyses.

PubMed

Thomas, Matthew C; Selinger, L Brent; Inglis, G Douglas

2012-08-01

The temporal dynamics of planktonic protists in river water have received limited attention despite their ecological significance and recent studies linking phagotrophic protists to the persistence of human-pathogenic bacteria. Using molecular-based techniques targeting the 18S rRNA gene, we studied the seasonal diversity of planktonic protists in Southwestern Alberta rivers (Oldman River Basin) over a 1-year period. Nonmetric multidimensional scaling analysis of terminal restriction fragment length polymorphism (T-RFLP) data revealed distinct shifts in protistan community profiles that corresponded to season rather than geographical location. Community structures were examined by using clone library analysis; HaeIII restriction profiles of 18S rRNA gene amplicons were used to remove prevalent solanaceous plant clones prior to sequencing. Sanger sequencing of the V1-to-V3 region of the 18S rRNA gene libraries from spring, summer, fall, and winter supported the T-RFLP results and showed marked seasonal differences in the protistan community structure. The spring library was dominated by Chloroplastidae (29.8%), Centrohelida (28.1%), and Alveolata (25.5%), while the summer and fall libraries contained primarily fungal clones (83.0% and 88.0%, respectively). Alveolata (35.6%), Euglenozoa (24.4%), Chloroplastida (15.6%), and Fungi (15.6%) dominated the winter library. These data demonstrate that planktonic protists, including protozoa, are abundant in river water in Southwestern Alberta and that conspicuous seasonal shifts occur in the community structure.

Seasonal Diversity of Planktonic Protists in Southwestern Alberta Rivers over a 1-Year Period as Revealed by Terminal Restriction Fragment Length Polymorphism and 18S rRNA Gene Library Analyses

PubMed Central

Thomas, Matthew C.; Selinger, L. Brent

2012-01-01

The temporal dynamics of planktonic protists in river water have received limited attention despite their ecological significance and recent studies linking phagotrophic protists to the persistence of human-pathogenic bacteria. Using molecular-based techniques targeting the 18S rRNA gene, we studied the seasonal diversity of planktonic protists in Southwestern Alberta rivers (Oldman River Basin) over a 1-year period. Nonmetric multidimensional scaling analysis of terminal restriction fragment length polymorphism (T-RFLP) data revealed distinct shifts in protistan community profiles that corresponded to season rather than geographical location. Community structures were examined by using clone library analysis; HaeIII restriction profiles of 18S rRNA gene amplicons were used to remove prevalent solanaceous plant clones prior to sequencing. Sanger sequencing of the V1-to-V3 region of the 18S rRNA gene libraries from spring, summer, fall, and winter supported the T-RFLP results and showed marked seasonal differences in the protistan community structure. The spring library was dominated by Chloroplastidae (29.8%), Centrohelida (28.1%), and Alveolata (25.5%), while the summer and fall libraries contained primarily fungal clones (83.0% and 88.0%, respectively). Alveolata (35.6%), Euglenozoa (24.4%), Chloroplastida (15.6%), and Fungi (15.6%) dominated the winter library. These data demonstrate that planktonic protists, including protozoa, are abundant in river water in Southwestern Alberta and that conspicuous seasonal shifts occur in the community structure. PMID:22685143

Annual distribution of allergenic fungal spores in atmospheric particulate matter in the Eastern Mediterranean; a comparative study between ergosterol and quantitative PCR analysis

NASA Astrophysics Data System (ADS)

Lang-Yona, N.; Dannemiller, K.; Yamamoto, N.; Burshtein, N.; Peccia, J.; Yarden, O.; Rudich, Y.

2012-03-01

Airborne fungal spores are an important fraction of atmospheric particulate matter and are major causative agents of allergenic and infectious diseases. Predicting the variability and species of allergy-causing fungal spores requires detailed and reliable methods for identification and quantification. There are diverse methods for their detection in the atmosphere and in the indoor environments; yet, it is important to optimize suitable methods for characterization of fungal spores in atmospheric samples. In this study we sampled and characterized total and specific airborne fungal spores from PM10 samples collected in Rehovot, Israel over an entire year. The total fungal spore concentrations vary throughout the year although the species variability was nearly the same. Seasonal equivalent spore concentrations analyzed by real-time quantitative-PCR-based methods were fall > winter > spring > summer. Reported concentrations based on ergosterol analysis for the same samples were and fall > spring > winter > summer. Correlation between the two analytical methods was found only for the spring season. These poor associations may be due to the per-spore ergosterol variations that arise from both varying production rates, as well as molecular degradation of ergosterol. While conversion of genome copies to spore concentration is not yet straightforward, the potential for improving this conversion and the ability of qPCR to identify groups of fungi or specific species makes this method preferable for environmental spore quantification. Identifying tools for establishing the relation between the presence of species and the actual ability to induce allergies is still needed in order to predict the effect on human health.

Snowmelt in the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Zhang, F.

2016-12-01

Snow accumulation and melting are important hydrological processes in the Tibetan Plateau (TP). Qualification of snow dynamics is helpful for water resources management. In this study, a case study of snow and runoff modeling in a glaciated catchment in south Tibet was firstly conducted and showed that MODIS snow cover data can be successfully used for snow model calibration. Following the method, snow accumulation and melting in the TP was simulated using a distributed degree-day model through zonal calibration. The simulation results showed that the spatial pattern of snowmelt is basically in accordance with that of precipitation with discrepancy mainly introduced by elevation and temperature lapse. During 1979-2010, average annual precipitation and snowmelt in the TP was 394 and 80 mm/yr, respectively, indicating that about 1/5 of the precipitation in the TP supplied the rivers, lakes, and groundwater etc in the form of snowmelt. Seasonal snowmelt accounted for 35%, 37%, 26%, and 2% of the annual gross in spring, summer, fall, and winter, respectively, with net accumulation of snow in fall and winter added to the snowmelt in the following spring and summer. The overall changing trends of annual precipitation and snowmelt in the TP were 4.1 and 0.4 mm/yr, respectively, with the most intensive snowmelt increase of about 3.0 mm/yr in the upstream of Tarim river basin (UTA) but decrease of about -1.4 mm/yr in the upstream of Mekong river basin (UME) due to the interacting impacts of temperature and precipitation. Significant increasing trend of snowmelt in spring shown in the UTA may benefit the local water use for irrigation etc.

Beaver herbivory of willow under two flow regimes: A comparative study on the Green and Yampa rivers

USGS Publications Warehouse

Breck, Stewart W.; Wilson, Kenneth R.; Andersen, Douglas C.

2003-01-01

The effect of flow regulation on plant-herbivore ecology has received very little attention, despite the fact that flow regulation can alter both plant and animal abundance and environmental factors that mediate interactions between them. To determine how regulated flows have impacted beaver (Castor canadensis) and sandbar willow (Salix exigua) ecology, we first quantified the abundance and mapped the spatial distribution of sandbar willow on alluvial sections of the flow-regulated Green River and free-flowing Yampa River in northwestern Colorado. We then established 16 and 15 plots (1 m × 2.7 m) in patches of willow on the Green and Yampa Rivers, respectively, to determine whether rates of beaver herbivory of willow differed between rivers (Green versus Yampa River), seasons (fall-winter versus spring-summer), and years (spring 1998-spring 1999 versus spring 1999-spring 2000). Areal extent of willow was similar on each river, but Green River willow patches were smaller and more numerous. Beavers cut more stems during fall and winter than spring and summer and cut over 6 times more stems (percentage basis) on the Green River than on the Yampa River. We attribute the between-river difference in herbivory to higher availability of willow, greater beaver density, and lower availability of young Fremont cottonwood (Populus deltoides subsp. wislizenii; an alternative food source) on the Green River. Flow regulation increased willow availability to beaver by promoting the formation of island patches that are continuously adjacent to water and feature a perimeter with a relatively high proportion of willow interfacing with water.

Annual distribution of allergenic fungal spores in atmospheric particulate matter in the eastern mediterranean; a comparative study between ergosterol and quantitative PCR analysis

NASA Astrophysics Data System (ADS)

Lang-Yona, N.; Dannemiller, K.; Yamamoto, N.; Burshtein, N.; Peccia, J.; Yarden, O.; Rudich, Y.

2011-10-01

Airborne fungal spores are an important fraction of atmospheric particulate matter and are major causative agents of allergenic and infectious diseases. Predicting the variability and species of allergy-causing fungal spores requires detailed and reliable methods for identification and quantification. There are diverse methods for their detection in the atmosphere and in the indoor environments; yet, it is important to optimize suitable methods for characterization of fungal spores in atmospheric samples. In this study we sampled and characterized total and specific airborne fungal spores from PM10 samples collected in Rohovot, Israel over an entire year. The total fungal spore concentrations vary throughout the year although the species variability was nearly the same. Seasonal equivalent spore concentrations analyzed by real-time quantitative-PCR-based methods were fall > winter > spring > summer. Reported concentrations based on ergosterol analysis for the same samples were and fall > spring > winter > summer. Correlation between the two analytical methods was found only for the spring season. These poor associations may be due to the per-spore ergosterol variations that arise from both varying production rates, as well as molecular degradation of ergosterol. While conversion of genome copies to spore concentration is not yet straightforward, the potential for improving this conversion and the ability of qPCR to identify groups of fungi or specific species makes this method preferable for environmental spore quantification. Identifying tools for establishing the relation between the presence of species and the actual ability to induce allergies is still needed in order to predict the effect on human health.

Resuspension and Shelf-Deep Ocean Exchange in the Northern California Current: New Insights From Underwater Gliders

NASA Astrophysics Data System (ADS)

Erofeev, A.; Barth, J. A.; Shearman, R. K.; Pierce, S. D.

2016-02-01

Shelf-deep ocean exchange is dominated by wind-driven upwelling and downwelling in the northern California Current. The interaction of strong, along-shelf jets with coastline and bottom topographic features can also create significant cross-margin exchange. We are using data from over 60,000 kilometers of autonomous underwater glider tracks to understand the temporal and spatial distribution of shelf-deep ocean exchange off central Oregon. Year-round glider observations of temperature, salinity, depth-averaged currents, chlorophyll fluorescence, light backscatter, and colored dissolved organic matter fluorescence from a single cross-margin transect are used to examine shelf-deep ocean exchange mechanisms. During summer, cross-margin exchange is dominated by wind-driven upwelling and the relaxation or reversal of the dominant southward winds. This process has been fairly well observed and studied due to the relatively low sea states and winds during summer. There is far less data from fall and winter off Oregon, a time of strong winds and large waves. We use autonomous underwater gliders to sample during the winter, including through the fall and spring transitions. Glider observations of suspended material detected via light backscatter, show time-space variations in resuspension in the bottom boundary layer due to winds, waves and currents. Examples of shelf-deep ocean exchange are shown by layers with high light backscatter separating from the bottom near the shelf break and extending into the interior along isopycnals. We describe these features and events in relationship to wind-forcing, along-shelf flows, and other forcing mechanisms.

Differences in Meteorological Conditions between Days with Persistent and Non-Persistent Pollution in Beijing, China

NASA Astrophysics Data System (ADS)

You, Ting; Wu, Renguang; Huang, Gang

2018-02-01

We compared the regional synoptic patterns and local meteorological conditions during persistent and non-persistent pollution events in Beijing using US NCEP-Department of Energy reanalysis outputs and observations from meteorological stations. The analysis focused on the impacts of high-frequency (period < 90 days) variations in meteorological conditions on persistent pollution events (those lasting for at least 3 days). Persistent pollution events tended to occur in association with slow-moving weather systems producing stagnant weather conditions, whereas rapidly moving weather systems caused a dramatic change in the local weather conditions so that the pollution event was short-lived. Although Beijing was under the influence of anomalous southerly winds in all four seasons during pollution events, notable differences were identified in the regional patterns of sea-level pressure and local anomalies in relative humidity among persistent pollution events in different seasons. A region of lower pressure was present to the north of Beijing in spring, fall, and winter, whereas regions of lower and higher pressures were observed northwest and southeast of Beijing, respectively, in summer. The relative humidity near Beijing was higher in fall and winter, but lower in spring and summer. These differences may explain the seasonal dependence of the relationship between air pollution and the local meteorological variables. Our analysis showed that the temperature inversion in the lower troposphere played an important part in the occurrence of air pollution under stagnant weather conditions. Some results from this study are based on a limited number of events and thus require validation using more data.

Fourteen Years of Diverse Annual No-Till Cropping in Washington’s Winter Wheat – Summer Fallow Region

USDA-ARS?s Scientific Manuscript database

We have completed the 14th year of a cropping systems experiment to evaluate diverse annual (i.e., no summer fallow) cropping systems using no-till as an alternative to tillage-intensive winter wheat (Triticum aestivum L.) – summer fallow (WW-SF). Soft white and hard white classes of winter and spri...

Developmental plasticity of mating calls enables acoustic communication in diverse environments

PubMed Central

Beckers, Oliver M; Schul, Johannes

2008-01-01

Male calls of the katydid Neoconocephalus triops exhibit substantial developmental plasticity in two parameters: (i) calls of winter males are continuous and lack the verse structure of summer calls and (ii) at equal temperatures, summer males produce calls with a substantially higher pulse rate than winter males. We raised female N. triops under conditions that reliably induced either summer or winter phenotype and tested their preferences for the call parameters that differ between summer and winter males. Neither generation was selective for the presence of verses, but females had strong preferences for pulse rates: only a narrow range of pulse rates was attractive. The attractive ranges did not differ between summer and winter females. Both male pulse rate and female preference for pulse rate changed with ambient temperature, but female preference changed more than the male calls. As a result, the summer call was attractive only at 25°C, whereas the slower winter call was attractive only at 20°C. Thus, developmental plasticity of male calls compensates for differences in temperature dependency between calls and preferences and enables the communication system to function in heterogeneous environments. The potential role of call plasticity during the invasion of new habitats is discussed. PMID:18302998

Seasonal variation in the acute effect of particulate air pollution on mortality in the China Air Pollution and Health Effects Study (CAPES)

PubMed Central

Chen, Renjie; Peng, Roger D.; Meng, Xia; Zhou, Zhijun; Chen, Bingheng; Kan, Haidong

2013-01-01

Epidemiological findings concerning the seasonal variation in the acute effect of particulate matter (PM) are inconsistent. We investigated the seasonality in the association between PM with an aerodynamic diameter of less than 10 μm (PM10) and daily mortality in 17 Chinese cities. We fitted the “main” time-series model after adjustment for time-varying confounders using smooth functions with natural splines. We established a “seasonal” model to obtain the season-specific effect estimates of PM10, and a “harmonic” model to show the seasonal pattern that allows PM10 effects to vary smoothly with the day in a year. At the national level, a 10 μg/m3 increase in the two-day moving average concentrations (lag 01) of PM10 was associated with 0.45% [95% posterior interval (PI), 0.15% to 0.76%], 0.17% (95% PI, −0.09% to 0.43%), 0.55% (95% PI, 0.15% to 0.96%) and 0.25% (95%PI, −0.05% to 0.56%) increases in total mortality for winter, spring, summer and fall, respectively. For the smoothly-varying plots of seasonality, we identified a two-peak pattern in winter and summer. The observed seasonal pattern was generally insensitive to model specifications. Our analyses suggest that the acute effect of particulate air pollution could vary by seasons with the largest effect in winter and summer in China. To our knowledge, this is the first multicity study in developing countries to analyze the seasonal variations of PM-related health effects. PMID:23500824

Microbial community production, respiration, and structure of the microbial food web of an ecosystem in the northeastern Atlantic Ocean

NASA Astrophysics Data System (ADS)

Maixandeau, Anne; LefèVre, Dominique; Karayanni, Hera; Christaki, Urania; van Wambeke, France; Thyssen, Melilotus; Denis, Michel; FernáNdez, Camila I.; Uitz, Julia; Leblanc, Karine; QuéGuiner, Bernard

2005-07-01

Gross community production (GCP), dark community respiration (DCR), and the biomass of the different size classes of organisms in the microbial community were measured in the northeastern Atlantic basin as part of the Programme Océan Multidisciplinaire Méso Echelle (POMME) project. The field experiment was conducted during three seasons (winter, spring, and late summer-fall) in 2001. Samples were collected from four different mesoscale structures within the upper 100 m. GCP rates increased from winter (101 ± 24 mmol O2 m-2 d-1) to spring (153 ± 27 mmol O2 m-2 d-1) and then decreased from spring to late summer (44 ± 18 mmol O2 m-2 d-1). DCR rates increased from winter (-47 ± 18 mmol O2 m-2 d-1) to spring (-97 ± 7 mmol O2 m-2 d-1) and then decreased from spring to late summer (50 ± 7 mmol O2 m-2 d-1). The onset of stratification depended on latitude as well as on the presence of mesoscale structures (eddies), and this largely contributed to the variability of GCP. The trophic status of the POMME area was defined as net autotrophic, with a mean annual net community production rate of +38 ± 18 mmol O2 m-2 d-1, exhibiting a seasonal variation from +2 ± 20 mmol O2 m-2 d-1 to +57 ± 20 mmol O2 m-2 d-1. This study highlights that small organisms (picoautotrophs, nanoautotrophs, and bacteria) are the main organisms contributing to biological fluxes throughout the year and that episodic blooms of microphytoplankton are related to mesoscale structures.

Variations of net ecosystem production due to seasonal precipitation differences in a tropical dry forest of northwest Mexico

NASA Astrophysics Data System (ADS)

Verduzco, Vivian S.; Garatuza-Payán, Jaime; Yépez, Enrico A.; Watts, Christopher J.; Rodríguez, Julio C.; Robles-Morua, Agustin; Vivoni, Enrique R.

2015-10-01

Due to their large extent and high primary productivity, tropical dry forests (TDF) are important contributors to atmospheric carbon exchanges in subtropical and tropical regions. In northwest Mexico, a bimodal precipitation regime that includes winter precipitation derived from Pacific storms and summer precipitation from the North American monsoon (NAM) couples water availability with ecosystem processes. We investigated the net ecosystem production of a TDF ecosystem using a 4.5 year record of water and carbon fluxes obtained from the eddy covariance method complemented with remotely sensed data. We identified a large CO2 efflux at the start of the summer season that is strongly related to the preceding winter precipitation and greenness. Since this CO2 efflux occurs prior to vegetation green-up, we infer that respiration is mainly due to decomposition of soil organic matter accumulated from the prior growing season. Overall, ecosystem respiration has an important effect on the net ecosystem production but can be overwhelmed by the strength of the primary productivity during the NAM. Precipitation characteristics during NAM have significant controls on sustaining carbon fixation in the TDF into the fall season. We identified that a threshold of ~350 to 400 mm of monsoon precipitation leads to a switch in the annual carbon balance in the TDF ecosystem from a net source (+102 g C/m2/yr) to a net sink (-249 g C/m2/yr). This monsoonal precipitation threshold is typically exceeded one out of every 2 years. The close coupling of winter and summer periods with respect to carbon fluxes suggests that the annual carbon balance is dependent on precipitation amounts in both seasons in TDF ecosystems.

Modeling Caribou Movements: Seasonal Ranges and Migration Routes of the Central Arctic Herd

PubMed Central

Nicholson, Kerry L.; Arthur, Stephen M.; Horne, Jon S.; Garton, Edward O.; Del Vecchio, Patricia A.

2016-01-01

Migration is an important component of the life history of many animals, but persistence of large-scale terrestrial migrations is being challenged by environmental changes that fragment habitats and create obstacles to animal movements. In northern Alaska, the Central Arctic herd (CAH) of barren-ground caribou (Rangifer tarandus granti) is known to migrate over large distances, but the herd’s seasonal distributions and migratory movements are not well documented. From 2003–2007, we used GPS radio-collars to determine seasonal ranges and migration routes of 54 female caribou from the CAH. We calculated Brownian bridges to model fall and spring migrations for each year and used the mean of these over all 4 years to identify areas that were used repeatedly. Annual estimates of sizes of seasonal ranges determined by 90% fixed kernel utilization distributions were similar between summer and winter (X̅ = 27,929 SE = 1,064 and X̅ = 26,585 SE = 4912 km2, respectively). Overlap between consecutive summer and winter ranges varied from 3.3–18.3%. Percent overlap between summer ranges used during consecutive years (X̅ = 62.4% SE = 3.7%) was higher than for winter ranges (X̅ = 42.8% SE = 5.9%). Caribou used multiple migration routes each year, but some areas were used by caribou during all years, suggesting that these areas should be managed to allow for continued utilization by caribou. Restoring migration routes after they have been disturbed or fragmented is challenging. However, prior knowledge of movements and threats may facilitate maintenance of migratory paths and seasonal ranges necessary for long-term persistence of migratory species. PMID:27045587

Effect of summer heat environment on body temperature, estrous cycles and blood antioxidant levels in Japanese Black cow.

PubMed

Sakatani, Miki; Balboula, Ahmed Z; Yamanaka, Kenichi; Takahashi, Masashi

2012-05-01

This study investigated the effect of summer heat environment on estrous cycles and blood antioxidant levels in Japanese Black cows. A total of 13 non-lactating Japanese Black cows (summer: 9, winter: 4) were examined. Body temperature was measured rectally and intravaginally using a thermometer and data logger, respectively. Estrous behavior was monitored using a radiotelemetric pedometer that recorded walking activity. Rectal temperatures were higher during summer than winter (P<0.001). There was an acute increase in vaginal temperature at the onset of estrus during winter but such an increase was not observed during summer. Walking activity during estrus decreased dramatically in the summer compared to the winter. Duration of estrous cycle was longer in summer (23.4 days, P<0.05) than winter (21.5 days), and the subsequent rise in progesterone concentrations following estrus tended to be delayed in summer. The level of thiobarbituric acid reactive substances (TBARS) in peripheral blood cells was higher during summer (P<0.05), while the levels of superoixde dismutase (SOD), glutathione peroxidase (GPx) and glutathione were lower (P<0.05). These results indicate that high ambient temperature during summer increases both body temperature and oxidative stress, and also reduces signs of estrus in Japanese Black cows. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

Two Dimensional Movement Patterns of Juvenile Winter Run and Late Fall Run Chinook Salmon at the Fremont Weir, Sacramento River, CA

DTIC Science & Technology

2017-07-01

ER D C/ EL T R- 17 -1 0 Two-Dimensional Movement Patterns of Juvenile Winter- Run and Late-Fall- Run Chinook Salmon at the Fremont Weir...default. ERDC/EL TR-17-10 July 2017 Two-Dimensional Movement Patterns of Juvenile Winter- Run and Late-Fall- Run Chinook Salmon at the Fremont Weir...Sacramento River, smaller winter- run Chinook and larger late-fall- run Chinook salmon were tagged and released into a 2D telemetry array dur- ing the

Migration of northern yellowstone elk: Implications of spatial structuring

USGS Publications Warehouse

White, P.J.; Proffitt, K.M.; Mech, L.D.; Evans, S.B.; Cunningham, J.A.; Hamlin, K.L.

2010-01-01

Migration can enhance survival and recruitment of mammals by increasing access to higher-quality forage or reducing predation risk, or both. We used telemetry locations collected from 140 adult female elk during 20002003 and 20072008 to identify factors influencing the migration of northern Yellowstone elk. Elk wintered in 2 semidistinct herd segments and migrated 10140 km to at least 12 summer areas in Yellowstone National Park (YNP) and nearby areas of Montana. Spring migrations were delayed after winters with increased snow pack, with earlier migration in years with earlier vegetation green-up. Elk wintering at lower elevations outside YNP migrated an average of 13 days earlier than elk at higher elevations. The timing of autumn migrations varied annually, but elk left their summer ranges at about the same time regardless of elevation, wolf numbers, or distance to their wintering areas. Elk monitored for multiple years typically returned to the same summer (96 fidelity, n 52) and winter (61 fidelity, n 41) ranges. Elk that wintered at lower elevations in or near the northwestern portion of the park tended to summer in the western part of YNP (56), and elk that wintered at higher elevations spent summer primarily in the eastern and northern parts of the park (82). Elk did not grossly modify their migration timing, routes, or use areas after wolf restoration. Elk mortality was low during summer and migration (8 of 225 elk-summers). However, spatial segregation and differential mortality and recruitment between herd segments on the northern winter range apparently contributed to a higher proportion of the elk population wintering outside the northwestern portion of YNP and summering in the western portion of the park. This change could shift wolf spatial dynamics more outside YNP and increase the risk of transmission of brucellosis from elk to cattle north of the park. ?? 2010 American Society of Mammalogists.

Studies of ice sheet hydrology using SAR

NASA Technical Reports Server (NTRS)

Bindschadler, R. A.; Vornberger, P. L.

1989-01-01

Analysis of SAR data of the Greenland ice sheet in summer and winter suggest the use of SAR to monitor the temporal hydrology of ice sheets. Comparisons of each SAR data set with summer Landsat TM imagery show an areal-positive correlation with summer SAR data and a negative correlation with winter SAR data. It is proposed that the summer SAR data are most sensitive to the variable concentrations of free water in the surface snow and that the winter SAR data indicate variations in snow grain size.

Preceding winter La Niña reduces Indian summer monsoon rainfall

NASA Astrophysics Data System (ADS)

Chakraborty, Arindam

2018-05-01

Leaving out the strong El Niño Southern Oscillation (ENSO) years, our understanding in the interannual variation of the Indian summer monsoon rainfall (ISMR) stands poor for the rest. This study quantifies the role of ENSO in the preceding winter on ISMR with a particular emphasis on ENSO-neutral summer and La Niña winter. Results show that, unlike the simultaneous ENSO-ISMR relationship, La Niña of previous winter reduces mean rainfall over the country by about 4% even during ENSO neutral summer. Moreover, when ENSO changes phase from La Niña in winter to El Niño in summer, ISMR is anomalously lower than during persisting El Niño years (‑14.5% and ‑5.3%, respectively), increasing the probability of severe drought. This suppression effect of La Niña of the preceding winter on summer monsoon precipitation over India is mostly experienced in its western and southern parts. Principal component analysis of the zonal propagation of surface pressure anomalies from winter to summer along Northern Hemisphere subtropics decomposes interannual variations of seasonally persisting anomalies from zonal propagations. The dominant modes are associated with the seasonal transition of the ENSO phase, and are well correlated with date of onset and seasonal mean rainfall of monsoon over India. These results improve our understanding of the interannual variations of ISMR and could be used for diagnostics of general circulation models.

Seasonal carbonate chemistry covariation with temperature, oxygen, and salinity in a fjord estuary: implications for the design of ocean acidification experiments.

PubMed

Reum, Jonathan C P; Alin, Simone R; Feely, Richard A; Newton, Jan; Warner, Mark; McElhany, Paul

2014-01-01

Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall). pCO2 exceeded the 2008-2011 mean atmospheric level (392 µatm) at all depths and seasons sampled except for the near-surface waters (< 10 m) in the summer. Further, undersaturated conditions with respect to the biogenic carbonate mineral aragonite were widespread (Ωar<1). We show that pCO2 values were relatively uniform throughout the water column and across regions in winter, enriched in subsurface waters in summer, and in the fall some values exceeded 2500 µatm in near-surface waters. Carbonate chemistry covaried to differing levels with temperature and oxygen depending primarily on season and secondarily on region. Salinity, which varied little (27 to 31), was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and Ωar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight the wide range of carbonate chemistry conditions organisms may currently experience in this and similar coastal ecosystems.

Seasonal Carbonate Chemistry Covariation with Temperature, Oxygen, and Salinity in a Fjord Estuary: Implications for the Design of Ocean Acidification Experiments

PubMed Central

Reum, Jonathan C. P.; Alin, Simone R.; Feely, Richard A.; Newton, Jan; Warner, Mark; McElhany, Paul

2014-01-01

Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall). pCO2 exceeded the 2008–2011 mean atmospheric level (392 µatm) at all depths and seasons sampled except for the near-surface waters (< 10 m) in the summer. Further, undersaturated conditions with respect to the biogenic carbonate mineral aragonite were widespread (Ωar<1). We show that pCO2 values were relatively uniform throughout the water column and across regions in winter, enriched in subsurface waters in summer, and in the fall some values exceeded 2500 µatm in near-surface waters. Carbonate chemistry covaried to differing levels with temperature and oxygen depending primarily on season and secondarily on region. Salinity, which varied little (27 to 31), was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and Ωar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight the wide range of carbonate chemistry conditions organisms may currently experience in this and similar coastal ecosystems. PMID:24586915

Temporal variation in the biochemical ecology of lower trophic levels in the Northern California Current

NASA Astrophysics Data System (ADS)

Miller, J. A.; Peterson, W. T.; Copeman, L. A.; Du, X.; Morgan, C. A.; Litz, M. N. C.

2017-06-01

There is strong correlative evidence that variation in the growth and survival of secondary consumers is related to the copepod species composition within the Northern California Current. Potential mechanisms driving these correlations include: (1) enhanced growth and survival of secondary consumers when lipid-rich, boreal copepod species are abundant, with cascading effects on higher trophic levels; (2) the regulation of growth and condition of primary and secondary consumers by the relative proportion of certain essential fatty acids (FAs) in primary producers; or (3) a combination of these factors. Disentangling the relative importance of taxonomic composition, lipid quantity, and FA composition on the nutritional quality of copepods requires detailed information on both the consumer and primary producers. Therefore, we collected phytoplankton and copepods at an oceanographic station for 19 months and completed species community analyses and generated detailed lipid profiles, including lipid classes and FAs, for both groups. There was strong covariation between species and biochemistry within and across trophic levels and distinct seasonal differences. The amount of total lipid within both the phytoplankton and copepod communities was twice as high in spring and summer than in fall and winter, and certain FAs, such as diatom indicators 20:5ω3 and 16:1ω7, comprised a greater proportion of the FA pool in spring and summer. Indicators of bacterial production within the copepod community were proportionally twice as high during fall and winter than spring and summer. Seasonal transitions in copepod FA composition were consistently offset from transitions in copepod species composition by approximately two weeks. The timing of the seasonal transition in copepod FAs reflected seasonal shifts in the species composition and/or biochemistry of primary producers more than seasonal shifts in the copepod species composition. These results emphasize the importance of interactions between the copepod community and their available phytoplankton prey in regulating the nutritional quality of primary consumers.

Seed germination and life history syndromes in the California chaparral

USGS Publications Warehouse

Keeley, J.E.

1991-01-01

Syndromes are life history responses that are correlated to environmental regimes and are shared by a group of species (Stebbins, 1974). In the California chaparral there are two syndromes contrasted by the timing of seedling recruitment relative to wildfires. One syndrome, here called the fire-recruiter or refractory seed syndrome, includes species (both resprouting and non-resprouting) which share the feature that the timing of seedling establishment is specialized to the first rainy season after fire. Included are woody, suffrutescent and annual life forms but no geophytes have this syndrome. These species are linked by the characteristic that their seeds have a dormancy which is readily broken by environmental stimuli such as intense heat shock or chemicals leached from charred wood. Such seeds are referred to as “refractory” and dormancy, in some cases, is due to seed coat impermeability (such seeds are commonly called hardseeded), but in other cases the mechanism is unknown. Seeds of some may require cold stratification and/or light in addition to fire related stimuli. In the absence of fire related cues, a portion or all of a species’ seed pool remains dormant. Most have locally dispersed seeds that persist in the soil seed bank until the site burns. Dispersal of propagules is largely during spring and summer which facilitates the avoidance of flowering and fruiting during the summer and fall drought. Within a life form (e.g., shrub, suffrutescent, etc.), the seeds of these species have less mass than those of species with non-refractory seeds and this possibly reflects the environmental favorableness of the postfire environment for seedling establishment. Regardless of when fire occurs, germination is normally delayed until late winter or early spring. In the absence of fire, or other disturbance, opportunities for population expansion are largely lacking for species with this syndrome. The other syndrome, here called the fire-resister or non-refractory seed syndrome, includes species that are resilient to frequent fires (mostly by vegetative resprouting), but require fire-free periods for recruiting new seedlings. Included are shrubs, subshrubs, suffrutescents, lianas, geophytes and annuals. All are linked by the characteristic that their seeds germinate in the absence of cues related to wildfires. In many cases no form of seed dormancy is present and the seeds germinate soon after dispersal; consequently these species do not accumulate a persistent seed bank. Germination and seedling establishment is independent of fire and thus opportunities for population expansion are also independent of fire. The demographic pattern of seedling recruitment varies with the life form. For shrubs, seedling recruitment may be restricted to sites free of fire for periods of a hundred years or more. Recruitment appears to require relatively mesic conditions and this may account for the patchy distribution of these species within the matrix of relatively arid sites. Finding such sites has selected for propagules specialized for wind or animal dispersal; the majority are bird dispersed. These shrub species all disperse fruits in fall and winter and this may have been selected to take advantage of migratory birds as well as to time dispersal to the winter rains typical of the mediterranean-climate. Germination typically occurs within several weeks of the first fall or winter rains. Maturation of flowers and fruits during the summer and fall drought may account for the distribution of these species on more mesic sites. Seed mass of these species is large and this may have been selected to provide an advantage to seedlings establishing under the canopy of this dense shrub community.

Numerical simulation of formation and preservation of Ningwu ice cave, Shanxi, China

NASA Astrophysics Data System (ADS)

Yang, S.; Shi, Y.

2015-10-01

Ice caves exist in locations where annual average air temperature is higher than 0 °C. An example is Ningwu ice cave, Shanxi Province, the largest ice cave in China. In order to quantitatively investigate the mechanism of formation and preservation of the ice cave, we use the finite-element method to simulate the heat transfer process at this ice cave. There are two major control factors. First, there is the seasonal asymmetric heat transfer. Heat is transferred into the ice cave from outside very inefficiently by conduction in spring, summer and fall. In winter, thermal convection occurs that transfers heat very efficiently out of the ice cave, thus cooling it down. Secondly, ice-water phase change provides a heat barrier for heat transfer into the cave in summer. The calculation also helps to evaluate effects of global warming, tourists, colored lights, climatic conditions, etc. for sustainable development of the ice cave as a tourism resource. In some other ice caves in China, managers have installed airtight doors at these ice caves' entrances with the intention of "protecting" these caves, but this in fact prevents cooling in winter and these cave ices will entirely melt within tens of years.

Numerical simulation of formation and preservation of Ningwu ice cave, Shanxi, China

NASA Astrophysics Data System (ADS)

Yang, S.; Shi, Y.

2015-04-01

Ice caves exist in locations where annual average temperature in higher than 0 °C. An example is Ningwu ice cave, Shanxi Province, the largest ice cave in China. In order to quantitatively explain the mechanism of formation and preservation of the ice cave, we use Finite Element Method to simulate the heat transfer process at this ice cave. There are two major control factors. First, there is the seasonal asymmetric heat transfer. Heat is transferred into the ice cave from outside, very inefficiently by conduction in spring, summer and fall. In winter, thermal convection occurs that transfers heat very efficiently out of the ice cave, thus cooling it down. Secondly, ice-water phase change provides a heat barrier for heat transfer into the cave in summer. The calculation also helps to evaluate effects of global warming, tourists, etc. for sustainable development of ice cave as tourism resource. In some other ice caves in China, managers installed air-tight doors at these ice caves entrance intending to "protect" these caves, but this prevent cooling down these caves in winters and these cave ices will entirely melt within tens of years.

Marine mammal acoustic detections in the northeastern Chukchi Sea, September 2007-July 2011

NASA Astrophysics Data System (ADS)

Hannay, David E.; Delarue, Julien; Mouy, Xavier; Martin, Bruce S.; Leary, Del; Oswald, Julie N.; Vallarta, Jonathan

2013-09-01

Several cetacean and pinniped species use the northeastern Chukchi Sea as seasonal or year-round habitat. This area has experienced pronounced reduction in the extent of summer sea ice over the last decade, as well as increased anthropogenic activity, particularly in the form of oil and gas exploration. The effects of these changes on marine mammal species are presently unknown. Autonomous passive acoustic recorders were deployed over a wide area of the northeastern Chukchi Sea off the coast of Alaska from Cape Lisburne to Barrow, at distances from 8 km to 200 km from shore: up to 44 each summer and up to 8 each winter. Acoustic data were acquired at 16 kHz continuously during summer and on a duty cycle of 40 or 48 min within each 4-h period during winter. Recordings were analyzed manually and using automated detection and classification systems to identify calls. Bowhead (Balaena mysticetus) and beluga (Delphinapterus leucas) whale calls were detected primarily from April through June and from September to December during their migrations between the Bering and Beaufort seas. Summer detections were rare and usually concentrated off Wainwright and Barrow, Alaska. Gray (Eschrichtius robustus) whale calls were detected between July and October, their occurrence decreasing with increasing distance from shore. Fin (Balaenoptera physalus), killer (Orcinus orca), minke (Balaenoptera acutorostrata), and humpback (Megaptera novaeangliae) whales were detected sporadically in summer and early fall. Walrus (Odobenus rosmarus) was the most commonly detected species between June and October, primarily occupying the southern edge of Hanna Shoal and haul-outs near coastal recording stations off Wainwright and Point Lay. Ringed (Pusa hispida) and bearded (Erignathus barbatus) seals occur year-round in the Chukchi Sea. Ringed seal acoustic detections occurred throughout the year but detection numbers were low, likely due to low vocalization rates. Bearded seal acoustic detections peaked in April and May during their breeding season, with much lower detection numbers in July and August, likely as a result of reduced calling rates after breeding season. Ribbon seals (Histriophoca fasciata) were only detected in the fall as they migrated south through the study area toward the Bering Sea. These results suggest a regular presence of marine mammals in the Chukchi Sea year-round, with species-dependent seasonal and spatial density variations.

Comparison of Summer and Winter California Central Valley Aerosol Distributions from Lidar and MODIS Measurements

NASA Technical Reports Server (NTRS)

Lewis, Jasper R., Jr.; DeYoung, Russell J.; Chu, D. Allen

2010-01-01

Aerosol distributions from two aircraft lidar campaigns conducted in the California Central Valley are compared in order to identify seasonal variations. Aircraft lidar flights were conducted in June 2003 and February 2008. While the PM2.5 concentration is highest in the winter, the aerosol optical depth measured from MODIS is highest in the summer. A seasonal comparison shows that PM2.5 in the winter can exceed summer PM2.5 by 55%, while summer AOD exceeds winter AOD by 43%. Higher temperatures wildfires in the summer produce elevated aerosol layers that are detected by satellite measurements, but not surface particulate matter monitors. Measurements of the boundary layer height from lidar instruments are necessary to incorporate satellite measurements with air quality measurements.

Wetland management and rice farming strategies to decrease methylmercury bioaccumulation and loads from the Cosumnes River Preserve, California

USGS Publications Warehouse

Eagles-Smith, Collin A.; Ackerman, Joshua T.; Fleck, Jacob; Windham-Myers, Lisamarie; McQuillen, Harry; Heim, Wes

2014-01-01

We evaluated mercury (Hg) concentrations in caged fish (deployed for 30 days) and water from agricultural wetland (rice fields), managed wetland, slough, and river habitats in the Cosumnes River Preserve, California. We also implemented experimental hydrological regimes on managed wetlands and post-harvest rice straw management techniques on rice fields in order to evaluate potential Best Management Practices to decrease methylmercury bioaccumulation within wetlands and loads to the Sacramento-San Joaquin River Delta. Total Hg concentrations in caged fish were twice as high in rice fields as in managed wetland, slough, or riverine habitats, including seasonal managed wetlands subjected to identical hydrological regimes. Caged fish Hg concentrations also differed among managed wetland treatments and post-harvest rice straw treatments. Specifically, Hg concentrations in caged fish decreased from inlets to outlets in seasonal managed wetlands with either a single (fall-only) or dual (fall and spring) drawdown and flood-up events, whereas Hg concentrations increased slightly from inlets to outlets in permanent managed wetlands. In rice fields, experimental post-harvest straw management did not decrease Hg concentrations in caged fish. In fact, in fields in which rice straw was chopped and either disked into the soil or baled and removed from the fields, fish Hg concentrations increased from inlets to outlets and were higher than Hg concentrations in fish from rice fields subjected to the more standard post-harvest practice of simply chopping rice straw prior to fall flood-up. Finally, aqueous methylmercury (MeHg) concentrations and export were highly variable, and seasonal trends in particular were often opposite to those of caged fish. Aqueous MeHg concentrations and loads were substantially higher in winter than in summer, whereas caged fish Hg concentrations were relatively low in winter and substantially higher in summer. Together, our results highlight the importance of habitat, seasonal processes, and wetland management practices on Hg cycling and ecological risk in aquatic ecosystems.

Effects of an evaporative cooling system on plasma cortisol, IGF-I, and milk production in dairy cows in a tropical environment

NASA Astrophysics Data System (ADS)

Titto, Cristiane Gonçalves; Negrão, João Alberto; Titto, Evaldo Antonio Lencioni; Canaes, Taissa de Souza; Titto, Rafael Martins; Pereira, Alfredo Manuel Franco

2013-03-01

Access to an evaporative cooling system can increase production in dairy cows because of improved thermal comfort. This study aimed to evaluate the impact of ambient temperature on thermoregulation, plasma cortisol, insulin-like growth factor 1 (IGF-I), and productive status, and to determine the efficiency of an evaporative cooling system on physiological responses under different weather patterns. A total of 28 Holstein cows were divided into two groups, one with and the other without access to a cooling system with fans and mist in the free stall. The parameters were analyzed during morning (0700 hours) and afternoon milking (1430 hours) under five different weather patterns throughout the year (fall, winter, spring, dry summer, and rainy summer). Rectal temperature (RT), body surface temperature (BS), base of tail temperature (TT), and respiratory frequency (RF) were lower in the morning ( P < 0.01). The cooling system did not affect RT, and both the groups had values below 38.56 over the year ( P = 0.11). Cortisol and IGF-I may have been influenced by the seasons, in opposite ways. Cortisol concentrations were higher in winter ( P < 0.05) and IGF-I was higher during spring-summer ( P < 0.05). The air temperature and the temperature humidity index showed positive moderate correlations to RT, BS, TT, and RF ( P < 0.001). The ambient temperature was found to have a positive correlation with the physiological variables, independent of the cooling system, but cooled animals exhibited higher milk production during spring and summer ( P < 0.01).

Effects of an evaporative cooling system on plasma cortisol, IGF-I, and milk production in dairy cows in a tropical environment.

PubMed

Titto, Cristiane Gonçalves; Negrão, João Alberto; Titto, Evaldo Antonio Lencioni; Canaes, Taissa de Souza; Titto, Rafael Martins; Pereira, Alfredo Manuel Franco

2013-03-01

Access to an evaporative cooling system can increase production in dairy cows because of improved thermal comfort. This study aimed to evaluate the impact of ambient temperature on thermoregulation, plasma cortisol, insulin-like growth factor 1 (IGF-I), and productive status, and to determine the efficiency of an evaporative cooling system on physiological responses under different weather patterns. A total of 28 Holstein cows were divided into two groups, one with and the other without access to a cooling system with fans and mist in the free stall. The parameters were analyzed during morning (0700 hours) and afternoon milking (1430 hours) under five different weather patterns throughout the year (fall, winter, spring, dry summer, and rainy summer). Rectal temperature (RT), body surface temperature (BS), base of tail temperature (TT), and respiratory frequency (RF) were lower in the morning (P < 0.01). The cooling system did not affect RT, and both the groups had values below 38.56 over the year (P = 0.11). Cortisol and IGF-I may have been influenced by the seasons, in opposite ways. Cortisol concentrations were higher in winter (P < 0.05) and IGF-I was higher during spring-summer (P < 0.05). The air temperature and the temperature humidity index showed positive moderate correlations to RT, BS, TT, and RF (P < 0.001). The ambient temperature was found to have a positive correlation with the physiological variables, independent of the cooling system, but cooled animals exhibited higher milk production during spring and summer (P < 0.01).

Seasonal influence on adherence to and effects of an interval walking training program on sedentary female college students in Japan.

PubMed

Tanabe, Aiko; Masuki, Shizue; Nemoto, Ken-Ichi; Nose, Hiroshi

2018-04-01

Habitual exercise training is recommended to young people for their health promotion, but adherence may be influenced by atmospheric temperature (T a ) if performed outdoors. We compared the adherence to and the effects of a home-based interval walking training (IWT) program on sedentary female college students between winter and summer. For summer training over 176 days, 48 subjects (18-22 years old) were randomly divided into two groups: the control group (CNT summer , n = 24), which maintained a sedentary lifestyle as before, and the IWT group (IWT summer , n = 24), which performed IWT while energy expenditure was monitored by accelerometry. For winter training over 133 days, another group of 47 subjects (18-24 years old) was randomly divided into CNT winter (n = 24) and IWT winter (n = 23), as in summer. The peak T a per day was 26 ± 6 °C (SD) (range of 9-35 °C) in summer, much higher than 7 ± 5 °C (range of - 3-20 °C) in winter (P < 0.001). During a ~ 50-day vacation period, participants walked 2.1 ± 0.3 (SE) days/week in IWT summer , less than 4.2 ± 0.3 days/week in IWT winter (P < 0.001), with half of the energy expenditure/week for fast walking during the winter vacation (P < 0.02), whereas both IWT groups walked ~ 2 days/week during a school period (P > 0.8). After training, the peak aerobic capacity and knee flexion force increased in IWT winter (P < 0.01) but not in CNT winter (P > 0.3). Conversely, these parameters decreased in the summer groups. Thus, the adherence to and effects of IWT on sedentary female college students in Japan decreased in summer at least partially due to a high T a .

A Conjugate Study of Mean Winds and Planetary Waves Employing Enhanced Meteor Radars at Rio Grande, Argentina (53.8degS) and Juliusruh, Germany (54.6degN)

NASA Technical Reports Server (NTRS)

Fritts, D. C.; Imura, H.; Lieberman, R.; Janches, D.; Singer, W.

2011-01-01

Two meteor radars with enhanced power and sensitivity and located at closely conjugate latitudes (54.6degN and 53.8degS) are employed for inter-hemispheric comparisons of mean winds and planetary wave structures. Our study uses data from June 2008 through May 2010 during which both radars provided nearly continuous wind measurements from approx.80 to 100 km. Monthly mean winds at 53.8degS exhibit a somewhat stronger westward mean zonal jet in spring and early summer at lower altitudes and no westward monthly mean winds at higher altitudes. In contrast, westward mean winds of approx.5-10 m/s at 54.6degN extend to above 96 km during late winter and early spring each year. Equatorward monthly mean winds extend approximately from spring to fall equinox at both latitudes, with amplitudes of approx.5-10 m/s and more rapid decreases in amplitude at 54.6degN at higher altitudes. Meridional mean winds are more variable at both latitudes during fall and winter, with both poleward and equatorward monthly means indicating longer-period variability. Planetary waves seen in the 2-day mean data are episodic and variable at both sites, exhibit dominant periodicities of approx.8-10 and 16-20 days and are more confined to late fall and winter at 54.6degN. At both latitudes, planetary waves in the two period bands coincide closely in time and exhibit similar horizontal velocity covariances that are positive (negative) at 54.6degN (53.8degS) during peak planetary wave responses.

Seasonal changes of 24-hour intraocular pressure rhythm in healthy Shanghai population

PubMed Central

Cheng, Jingyi; Xiao, Ming; Xu, Huan; Fang, Shaobin; Chen, Xu; Kong, Xiangmei; Sun, Xinghuai

2016-01-01

Abstract The aim of the present study was to investigate and compare the 24-hour intraocular pressure (IOP) rhythms in winter and summer in the healthy population of Shanghai, China. This is a cross-sectional study in which 24-hour IOP measurements were taken for all eligible healthy volunteers in winter and summer, respectively, and the temperature, hours of sunlight (sunlight time), and circulatory parameters, including heart rate, systolic blood pressure, and diastolic blood pressure, were also recorded. The 24-hour IOP curves and IOP parameters (mean, peak, trough, and fluctuation of IOP together with the diurnal-to-nocturnal IOP change) in winter and summer were obtained and compared. The magnitude of IOP changes from summer to winter was also calculated. A total of 29 participants (58 eyes), 14 (48.28%) male and 15 (51.72%) female, aged 43.66 ± 12.20 (19–61) years, were considered eligible for this study. Generally, IOP decreased progressively before noon, increased notably in the nocturnal period, and peaked at 12:00 am in winter and at 2:00 am in summer. The pattern of 24-hour IOP in winter and summer was significantly different (P = 0.002). The average IOPs from 4:00 pm to 8:00 am, except for 6:00 am, were significantly higher in winter (P < 0.05). However, no significant differences were shown after adjusting for temperature and/or sunlight time. From summer to winter, the extent of IOP increase was mostly around 0 to 3 mm Hg, and the IOPs increased more significantly in the nocturnal period than in the diurnal period (P = 0.05). The 24-hour IOP rhythms were different in winter and summer, with higher IOP level in winter. Temperature and sunlight time, which are independent of heart rate and blood pressure, affected the 24-hour IOP rhythms in healthy people in Shanghai, China. Further investigations are expected for the rhythm of some endogenous substance secretion and the inner mechanism of regulation of IOP. PMID:27495076

Comparative biology of Uncinaria spp. in the California sea lion (Zalophus californianus) and the northern fur seal (Callorhinus ursinus) in California.

PubMed

Lyons, E T; DeLong, R L; Gulland, F M; Melin, S R; Tolliver, S C; Spraker, T R

2000-12-01

Studies on several aspects of the life cycle of hookworms (Uncinaria spp.) in the California sea lion (Zalophus californianus) and northern fur seal (Callorhinus ursinus) were conducted on material collected on San Miguel Island (SMI), California and at The Marine Mammal Center, Sausalito, California in 1997, 1998, and 1999. Examination of Z. californianus intestines for adult hookworms and feces for eggs revealed that longevity of these parasites in pups is about 6-8 mo, and infections are probably not present in older sea lions. Parasitic third-stage larvae (L3) were recovered from the ventral abdominal tissue of Z. californianus, suggesting transmammary transmission. Callorhinus ursinus pups had no hookworm eggs in their feces or adult worms (except for 1 probable contaminant) in their intestines in the fall and early winter, revealing that adult Uncinaria spp. are spontaneously lost at <3 mo of age of the pups. Sand samples from rookeries, used by both Z. californianus and C. ursinus, on SMI were negative for free-living, L3 in summer months but positive in fall and winter months, indicating seasonality occurred.

Wind Induced Sediment Resuspension in a Microtidal Estuary

NASA Technical Reports Server (NTRS)

Booth, J. G.; Miller, R. L.; McKee, B. A.; Leathers, R. A.

1999-01-01

Bottom sediment resuspension frequency, duration and extent (% of bottom sediments affected) were characterized for the fifteen month period from September 1995 to January 1997 for the Barataria Basin, LA. An empirical model of sediment resuspension as a function of wind speed, direction, fetch and water depth was derived from wave theory. Water column turbidity was examined by processing remotely sensed radiance information from visible and near-IR AVHRR imagery. Based on model predictions, wind induced resuspension occurred during all seasons of this study. Seasonal characteristics for resuspension reveal that late fall, winter and early spring are the periods of most frequent and intense resuspension. Model predictions of the critical wind speed required to induce resuspension indicate that winds of 4 m/s (averaged over all wind directions resuspend approximately 50% of bottom sediments in the water bodies examined. Winds of this magnitude (4 m/s) occurred for 80% of the time during the late fall, winter and early spring and for approximately 30% of the time during the summer. More than 50% of the bottom sedimets are resuspended throughout the year, indicating the importance of resuspension as a process affecting sediment and biogeochemical fluxes in the Barataria Basin.

Seasonal distribution, aggregation, and habitat selection of common carp in Clear Lake, Iowa

USGS Publications Warehouse

Penne, C.R.; Pierce, C.L.

2008-01-01

The common carp Cyprinus carpio is widely distributed and frequently considered a nuisance species outside its native range. Common carp are abundant in Clear Lake, Iowa, where their presence is both a symptom of degradation and an impediment to improving water quality and the sport fishery. We used radiotelemetry to quantify seasonal distribution, aggregation, and habitat selection of adult and subadult common carp in Clear Lake during 2005-2006 in an effort to guide future control strategies. Over a 22-month period, we recorded 1,951 locations of 54 adults and 60 subadults implanted with radio transmitters. Adults demonstrated a clear tendency to aggregate in an offshore area during the late fall and winter and in shallow, vegetated areas before and during spring spawning. Late-fall and winter aggregations were estimated to include a larger percentage of the tracked adults than spring aggregations. Subadults aggregated in shallow, vegetated areas during the spring and early summer. Our study, when considered in combination with previous research, suggests repeatable patterns of distribution, aggregation, and habitat selection that should facilitate common carp reduction programs in Clear Lake and similar systems. ?? Copyright by the American Fisheries Society 2008.

Late archaic settlement systems in the northern Rio Grande

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vierra, Bradley J.

2003-01-01

Last year at these meetings I proposed a possible seasonal transhumance pattern for the Late Archaic in the northern Rio Grande region. This pattern involved the movement of groups from the lowland juniper-savanna grasslands in the early summer, to the upland ponderosa pindmixed conifer forests in the mid to late summer, and then back down to the piiion-juniper woodlands during the fall. The Rio Grande Valley was also used for winter habitation sites. Following on this research, I take the next step by studying the inter-assemblage variability represented in a sample of open-air sites located within each of these vegetationmore » communities. The results indicate that there are significant differences in reduction tactics represented between valley habitation vs., upland campsites, and that these site sites are linked together by obsidian procurement patterns.« less

Survival of young American alligators on a Florida lake

USGS Publications Warehouse

Woodward, A.R.; Hines, T.C.; Abercrombie, C.L.; Nichols, J.D.

1987-01-01

A capture-recapture study was conducted on Orange Lake, Florida, from 1979 through 1984 to estimate survival rates of young in an American alligator (Alligator mississippiensis) populations. Hatchlings remained together in sibling groups (pods) for at least their 1st year and then began to disperse during their 2nd spring and summer. Mortality through mid-November of their 1st year was negligible. Jolly-Seber (JS) survival estimates of hatchlings for 6 and 12 months were 76 and 41%, respectively. The 2-year JS estimate for the 1980 cohort was 8%. Minimum-Known-Alive (MKA) survival values were 72 and 46% of JS estimates for 6 months and 1 year of age. Survival during the 2nd 6 months of life (spring-summer) tended to be lower than survival during the 1st 6 months (fall-winter).

Seasonal variation in body mass, body temperature and thermogenesis in the Hwamei, Garrulax canorus.

PubMed

Wu, Mei-Xiu; Zhou, Li-Meng; Zhao, Li-Dan; Zhao, Zhi-Jun; Zheng, Wei-Hong; Liu, Jin-Song

2015-01-01

The basal thermogenesis of birds is beginning to be viewed as a highly flexible physiological trait influenced by environmental fluctuations, particularly changes in ambient temperature (Ta). Many birds living in regions with seasonal fluctuations in Ta typically respond to cold by increasing their insulation and adjusting their metabolic rate. To understand these metabolic adaptations, body temperature (Tb), metabolic rate (MR), thermal neutral zone (TNZ) and thermal conductance were measured within a range of temperatures from 5 to 40°C in free-living Hwamei, Garrulax canorus, in both winter and summer. Body mass was 61.2±0.3g in winter and 55.5±1.0g in summer, and mean Tb was 41.6±0.1°C in winter and 42.3±0.1°C in summer. TNZ was between 28.3 and 35.1°C in winter and between 28.7 and 33.2°C in summer. The mean basal metabolic rate (BMR) within TNZ was 203.32±11.81ml O2 h(-1) in winter and 168.99±6.45ml O2 h(-1) in summer. Minimum thermal conductance was 3.73±0.09joulesg(-1)h(-1)°C(-1) in winter and 3.26±0.06joulesg(-1)h(-1)°C(-1) in summer. Birds caught in winter had higher body mass, MR, and more variable TNZ than those in summer. The increased winter BMR indicates improved ability to cope with cold and maintenance of a high Tb. These results show that the Hwamei's metabolism is not constant, but exhibits pronounced seasonal phenotypic flexibility associated with maintenance of a high Tb. Copyright © 2014 Elsevier Inc. All rights reserved.

Atmospheric ammonia measurements along the coastal lines of Southeastern China: Implications for inorganic nitrogen deposition to coastal waters

NASA Astrophysics Data System (ADS)

Wu, Shui-Ping; Dai, Lu-Hong; Wei, Ya; Zhu, Heng; Zhang, Yin-Ju; Schwab, James J.; Yuan, Chung-Shin

2018-03-01

Ambient NH3 concentrations were determined using Ogawa passive samplers along the coastal lines of southeast China from June 2015 to May 2017. Additional monitoring of PM2.5 and precipitation around Xiamen Bay during the period from November 2015 to May 2017 were carried out to estimate atmospheric inorganic nitrogen (IN) deposition to the bay. Distinct seasonal variations of ambient NH3 were observed with summer averages 1.41-5.56 times higher than winter, which agreed well with the seasonal trend of air temperature. Nitrate concentrations (pNO3-) in PM2.5 were significantly higher than ammonium concentrations (pNH4+), and both species showed higher concentrations in winter and spring and lower values in summer and fall which were influenced mainly by the monsoon cycle, gas-to-particle transformation process and rain washout. Paired t-testing revealed that no significant differences of pNO3- and pNH4+ between the urban and suburban sites around the Xiamen Bay. Unlike pNO3- and pNH4+, there were no clear seasonal trends for NH4+ and NO3- concentrations in precipitation samples (wNH4+ and wNO3-). On average, the deposition of IN consisted of NH3-N (27.4-28.2%) and pNO3--N (25.9-26.8%), followed by pNH4+-N (17.0-17.7%), wNH4+-N (14.5%), wNO3--N (13.3-13.8%) and NO2-N (0.35-0.46%); and showed distinct seasonal trends with higher values in winter/spring and lower values in summer/fall. In 2016, the total IN deposition was determined to be 36.45 and 35.92 kg N ha-1 at the urban and suburban sites around the Xiamen Bay, respectively. The proportion of IN deposition to total IN loads (terrestrial + atmospheric), varied over the range of 7.1-13.3% depending on the data source of riverine influx. Our observations revealed that the total IN deposition could account for 9.6-25.1% (based on primary productivity over Taiwan Strait) and 1.7-5.3% (based on primary productivity in Guangdong coastal region) of new productivity in Xiamen Bay, respectively. As an important nutrient source, the atmospheric deposition of N could have significant impacts on coastal marine ecosystems.

Comparison of Summer and Winter California Central Valley Aerosol Distributions from Lidar and MODIS Measurements

NASA Technical Reports Server (NTRS)

Lewis, Jasper; DeYoung, Russell; Ferrare, Richard; Chu, D. Allen

2010-01-01

Aerosol distributions from two aircraft lidar campaigns conducted in the California Central Valley are compared in order to identify seasonal variations. Aircraft lidar flights were conducted in June 2003 and February 2007. While the ground PM(sub 2.5) concentration is highest in the winter, the aerosol optical depth measured from MODIS is highest in the summer. A seasonal comparison shows that PM(sub 2.5) in the winter can exceed summer PM(sub 2.5) by 55%, while summer AOD exceeds winter AOD by 43%. Higher temperatures and wildfires in the summer produce elevated aerosol layers that are detected by satellite measurements, but not surface particulate matter monitors. Temperature inversions, especially during the winter, contribute to higher PM(sub 2.5) measurements at the surface. Measurements of the boundary layer height from lidar instruments provide valuable information need to understand the relationship between satellite measurements of optical depth and in-situ measurements of PM(sub 2.5).

Inversion climatology at San Jose, California

NASA Technical Reports Server (NTRS)

Morgan, T.; Bornstein, R. D.

1977-01-01

Month-to-month variations in the early morning surface-based and near-noon elevated inversions at San Jose, Calif., were determined from slow rise radiosondes launched during a four-year period. A high frequency of shallow, radiative, surface-based inversions were found in winter during the early morning hours, while during the same period in summer, a low frequency of deeper based inversions arose from a combination of radiative and subsidence processes. The frequency of elevated inversions in the hours near noon was lowest during fall and spring, while inversion bases were highest and thicknesses least during these periods.

Environmental Assessment For the Proposed Construction of A Hazardous Materials Issue Facility and a Hazardous Wastes Storage Facility at Buckley Air Force Base, Colorado

DTIC Science & Technology

2005-04-01

July 2002, and expires 30 June 2007 (BAFB 2001). In July 2002, the CDPHE performed an inspection of...months during the winter, spring, and fall to 9.8 million gallons for the summer months, such as July . BAFB disposed of approximately 1,477 tons of...assistance, please contact Amy Pallante , our Section 106 Compliance Coordinator, at (303) 866-4678. Sincerely, 1 " . ~"l·v’\\. /,. , fl: ··[;uf. . UV’"\\.:\\... .. ~oc-Georgianna Contigugli v State Historic Preservation Officer

Intercontinental spread of asian-origin H5N8 to North America through Beringia by migratory birds

USGS Publications Warehouse

Lee, Dong-Hun; Kim Torchetti, Mia; Winker, Kevin; Ip, Hon S.; Swayne, David E.; Song, Chang-Seon

2015-01-01

Phylogenetic network analysis and understanding of waterfowl migration patterns suggest the Eurasian H5N8 clade 2.3.4.4 avian influenza virus emerged in late 2013 in China, spread in early 2014 to South Korea and Japan, and reached Siberia and Beringia by summer 2014 via migratory birds. Three genetically distinct subgroups emerged and subsequently spread along different flyways during fall 2014 into Europe, North America, and East Asia, respectively. All three subgroups reappeared in Japan, a wintering site for waterfowl from Eurasia and parts of North America.

Scientific-Technical and Business Careers Training Grant

NASA Technical Reports Server (NTRS)

Conway, Mary P.

2001-01-01

The 1996 renewal of the NGT2-1001 grant included three objectives and expected outcomes. The information highlights the results and progress to address the grant objectives and outcomes for the time period of July 1, 2000 through June 30, 2001. Objective Number One indicated that the internship staff would annually recruit and place at least 90 community college students in internship positions related to their college majors. Internship enrollments for the summer, fall, winter and spring quarters of 2000-2001 show an average enrollment of 121 students per quarter. This number includes (13) interns sponsored by Ames contractors.

Aerosol size distribution and new particle formation events in the suburb of Xi'an, northwest China

NASA Astrophysics Data System (ADS)

Peng, Yan; Liu, Xiaodong; Dai, Jin; Wang, Zhao; Dong, Zipeng; Dong, Yan; Chen, Chuang; Li, Xingmin; Zhao, Na; Fan, Chao

2017-03-01

Particle number concentration and size distribution are important for better understanding the characteristics of aerosols. However, their measurements are scarce in western China. Based on the first measurement of particle number size distribution (10-487 nm) in the suburb of Xi'an, northwest China from November 2013 to December 2014, the seasonal, monthly and diurnal average particle number concentrations were investigated, and the characteristics of new particle formation (NPF) events and their dependencies on meteorological parameters also discussed. The results showed that the annual average particle number concentrations in the nucleation (NNUC), Aitken (NAIT), and Accumulation (NACC) size ranges were 960 cm-3, 4457 cm-3, 3548 cm-3, respectively. The mean total particle number concentration (NTOT) was 8965 cm-3 and largely dominated by particles in Aitken mode. The number concentration was dominated by particles around 67.3 nm in spring, summer and fall, while about 89.8 nm in winter. The percentage of the ultrafine size range (UFP, particles of diameter below 100 nm) to total particle number concentration was 63.2%, 69.6%, 62.2% and 58.1% in four seasons. The diurnal variation of the nucleation mode particles was mainly influenced by NPF events in summer, while by both traffic densities and NPF events in spring, fall and winter. The diurnal variation of the number concentration of Aitken mode particles correlated with the traffic emission in spring, fall and winter, while in summer it more correlated with contribution of the growth of the nucleation mode particles. The burst of nucleation mode particles typically started in the daytime (08:15-16:05, LST). The growth rates of nucleated particles ranged from 2.8 to 10.7 nm h-1 with an average of 5.0 ± 1.9 nm h-1. Among observed 66 NPF events from 347 effective measurement days, 85 percent of their air masses came from north or northwest China, resulting in a low concentration of pre-existing particles, and only 15 percent came southerly from Qingling Mountains. Based on their growth rate, 64 and 36 percent of their subsequent particles, corresponding to types 1 and 2 NPF events, grew and seldom grew after the burst of nucleation mode particles. For type 1 NPF event, the nucleated particles could grow up to 40 nm or larger when surface winds shifted from westerly to easterly or southeasterly (from village areas). For type 2 NPF events, the particles kept almost unchanged when the winds stayed westerly. This implied that the surface wind direction with different emissions might play an important role in new particle growth in suburb of Xi'an.

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.

PubMed

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.

Long-term dynamics of winter and summer annual communities in the Chihuahuan Desert

USGS Publications Warehouse

Guo, Q.; Brown, J.H.; Valone, T.J.

2002-01-01

Winter and summer annuals in the Chihuahuan Desert have been intensively studied in recent years but little is known about the similarities and differences in the dynamics between these two communities. Using 15 yr of census data from permanent quadrats, this paper compared the characteristics and temporal dynamics of these two distinct, spatially co-existent but temporally segregated communities. Although the total number of summer annual species recorded during our 15 yr of observation was higher than winter annuals, the mean number of species observed each year was higher in the winter community. The winter community exhibited lower temporal variation in total plant abundance and populations of individual species, lower species turnover rate and higher evenness than the summer community. The rank abundances of species in winter were significantly positively correlated for a period of up to 7 yr while in summer significant positive correlations in rank abundance disappeared after 2 to 3 yr. The higher seasonal species diversity (i.e. number of species observed in each season) in winter rather than the overall special pool (over 15 yr) may be responsible for the greater community stability of winter annuals. The difference in long-term community dynamics between the two communities of annual plants are likely due to the differences in total species pool, life history traits (e.g. seed size), and seasonal climatic regimes.

Seasonal and distributional patterns of seabirds along the Aleutian Archipelago

USGS Publications Warehouse

Renner, M.; Hunt, G.L.; Piatt, John F.; Byrd, G.V.

2008-01-01

The Aleutian Archipelago is of global importance to seabirds during the northern summer, but little is known about seabird use of these waters during winter. We compare summer and winter abundances of seabirds around 3 islands: Buldir in the western, Kasatochi in the central, and Aiktak in the eastern Aleutians. The density of combined seabird biomass in nearshore marine waters was higher in summer than in winter at Buldir and Kasatochi, but was higher in winter at Aiktak, despite the departure of abundant migratory species. Comparing foraging guilds, we found that only piscivores increased at the western and central sites in winter, whereas at the eastern site several planktivorous species increased as well. The only planktivore remaining in winter at the central and western sites in densities comparable to summer densities was whiskered auklet Aethia pygmaea. Crested auklet Aethia cristatella and thick-billed murre Uria lomvia showed the greatest proportional winter increase at the eastern site. The seasonal patterns of the seabird communities suggest a winter breakdown of the copepod-based food web in the central and western parts of the archipelago, and a system that remains rich in euphausiids in the eastern Aleutians. We suggest that in winter crested auklets take the trophic role that short-tailed shearwaters Puffinus tenuirostris occupy during summer. We hypothesize that advection of euphausiids in the Aleutian North Slope Current is important for supporting the high biomass of planktivores that occupy the Unimak Pass region on a year-round basis. ?? Inter-Research 2008.

Spacebased Observations of the Oceanic Responses to Monsoons in South China Sea and Arabian Sea

NASA Technical Reports Server (NTRS)

Xie, Xiao-Su; Liu, W. Timothy

2000-01-01

A large percentage of the world's population and their agrarian economy must endure the vagaries of the monsoons over the tropical oceans between Africa and the Philippines. We know very little about the oceanic responses to changes of the monsoon in the South China Sea (SCS), which is under the influence of the East Asian Monsoon System, and the Arabian Sea (AS), which is dominated by the Indian Monsoon System; oceanic observations are sparse in both regions. Data from spaceborne microwave scatterometers and radiometers have been used to estimate the two major atmospheric forcing, momentum flux and latent heat flux (LHF), which change with the monsoon winds. Spaceborne sensors also observed the surface signatures of the oceanic response: SST and sea level changes (SLC. Sufficient durations of these data have recently become available to allow the meaningful studies of the annual cycles and interannual anomalies. In SCS, the winter monsoon is strong and steady but the summer monsoon is weak and has large intraseasonal fluctuations. In AS, the summer monsoon is much stronger than the winter monsoon. Significant correlations between LHF and SST tendency, and between curl of wind stress and SLC are found in both oceans. In the north SCS, winds are strong and dry, LHF is high, and ocean cooling is also large in fall; LHF is low and the ocean warms up in spring. In AS, LHF and SST tendency have a semi annual period; LHF is high in summer when the wind is strong and in winter when the wind is dry. Along the coast of Oman, the strong summer southwest monsoon causes intense upwelling, low SST and LHF in summer; such wind-driven SST changes is not as obvious along the Vietnam coast because of the weaker summer monsoon. The negative correlation between curl of wind stress and SLC found in the central basins of both SCS and AS agrees with a simple Ekman pumping scenario. Cyclonic winds drive surface divergence and upwelling in the ocean; the rise of the thermocline causes lower sea levels. Anticyclonic winds cause higher SLC. The exceptions (positive correlations) are found in the coastal regions in the north and the south of SCS, off the west coast of India between 5N and 10N, and along the coast of Somalia.

Estimating Carcass Persistence and Scavenging Bias in a Human Influenced Landscape

USGS Publications Warehouse

Flint, Paul L.; Lance, Ellen W.; Sowl, Kristine M.; Donnelly, Tyrone F.

2010-01-01

We examined variation in persistence rates of waterfowl carcasses placed along a series of transects in tundra habitats in western Alaska. This study was designed to assess the effects of existing tower structures and was replicated with separate trials in winter, summer and fall as both the resident avian population and the suite of potential scavengers varied seasonally. Carcass persistence rates were uniformly low, with <50% of carcasses persisting for more than a day on average. Persistence rate varied by carcass age, carcass size, among transects and was lowest in the fall and highest in the summer. We found little support for models where persistence varied in relation to the presence of tower structures. We interpret this as evidence that scavengers were not habituated to searching for carcasses near these structures. Our data demonstrate that only a small fraction of bird carcasses are likely to persist between searches, and if not appropriately accounted for, scavenging bias could significantly influence bird mortality estimates. The variation that we documented suggests that persistence rates should not be extrapolated among tower locations or across time periods as the variation in carcass persistence will result in biased estimates of total bird strike mortality.

Ranging behavior relates to welfare indicators pre- and post-range access in commercial free-range broilers.

PubMed

Taylor, Peta S; Hemsworth, Paul H; Groves, Peter J; Gebhardt-Henrich, Sabine G; Rault, Jean-Loup

2018-06-01

Little is known about the effect of accessing an outdoor range on chicken welfare. We tracked individual ranging behavior of 538 mixed-sex Ross 308 chickens on a commercial farm across 4 flocks in winter and summer. Before range access, at 17 to 19 d of age, and post-range access, at 30 to 33 and 42 to 46 d of age in winter and summer flocks respectively, welfare indicators were measured on chickens (pre-range: winter N = 292; summer N = 280; post-range: winter N = 131; summer N = 140), including weight, gait score, dermatitis and plumage condition. Post-ranging autopsies were performed (winter: N = 170; summer: N = 60) to assess breast burn, leg health, and ascites. Fewer chickens accessed the range in winter flocks (32.5%) than summer flocks (82.1%). Few relationships between welfare and ranging were identified in winter, likely due to minimal ranging and the earlier age of post-ranging data collection compared to summer flocks. In summer flocks prior to range access, chickens that accessed the range weighed 4.9% less (P = 0.03) than chickens that did not access the range. Pre-ranging weight, gait score, and overall plumage cover predicted the amount of range use by ranging chickens in summer flocks (P < 0.01), but it explained less than 5% of the variation, suggesting other factors are associated with ranging behavior. In summer flocks post-range access, ranging chickens weighed 12.8% less than non-ranging chickens (P < 0.001). More range visits were associated with lower weight (P < 0.01), improved gait scores (P = 0.02), greater breast plumage cover (P = 0.02), lower ascites index (P = 0.01), and less pericardial fluid (P = 0.04). More time spent on the range was associated with lower weight (P < 0.01) and better gait scores (P < 0.01). These results suggest that accessing an outdoor range in summer is partly related to changes in broiler chicken welfare. Further investigations are required to determine causation.

Subcellular distribution of raffinose oligosaccharides and other metabolites in summer and winter leaves of Ajuga reptans (Lamiaceae).

PubMed

Findling, Sarah; Zanger, Klaus; Krueger, Stephan; Lohaus, Gertrud

2015-01-01

In Ajuga reptans, raffinose oligosaccharides accumulated during winter. Stachyose, verbascose, and higher RFO oligomers were exclusively found in the vacuole whereas one-fourth of raffinose was localized in the stroma. The evergreen labiate Ajuga reptans L. can grow at low temperature. The carbohydrate metabolism changes during the cold phase, e.g., raffinose family oligosaccharides (RFOs) accumulate. Additionally, A. reptans translocates RFOs in the phloem. In the present study, subcellular concentrations of metabolites were studied in summer and winter leaves of A. reptans to gain further insight into regulatory instances involved in the cold acclimation process and into the function of RFOs. Subcellular metabolite concentrations were determined by non-aqueous fractionation. Volumes of the subcellular compartments of summer and winter leaves were analyzed by morphometric measurements. The metabolite content varied strongly between summer and winter leaves. Soluble metabolites increased up to tenfold during winter whereas the starch content was decreased. In winter leaves, the subcellular distribution showed a shift of carbohydrates from cytoplasm to vacuole and chloroplast. Despite this, the metabolite concentration was higher in all compartments in winter leaves compared to summer leaves because of the much higher total metabolite content in winter leaves. The different oligosaccharides did show different compartmentations. Stachyose, verbascose, and higher RFO oligomers were almost exclusively found in the vacuole whereas one-fourth of raffinose was localized in the stroma. Apparently, the subcellular distribution of the RFOs differs because they fulfill different functions in plant metabolism during winter. Raffinose might function in protecting chloroplast membranes during freezing, whereas higher RFO oligomers may exert protective effects on vacuolar membranes. In addition, the high content of RFOs in winter leaves may also result from reduced consumption of assimilates.

Lead exposure in Canada geese of the Eastern Prairie Population

USGS Publications Warehouse

DeStefano, S.; Brand, C.J.; Rusch, D.H.; Finley, Daniel L.; Gillespie, M.M.

1991-01-01

We monitored lead exposure in Eastern Prairie Population Canada geese during summer-winter, 1986-1987 and 1987-1988 at 5 areas. Blood lead concentrations in geese trapped during summer at Cape Churchill Manitoba were below levels indicative of recent lead exposure (0.18 ppm). Geese exposed to lead (≥0.18 ppm blood lead) increased to 7.6% at Oak Hammock Wildlife Management Area (WMA), southern Manitoba, where lead shot was still in use, and to 10.0% at Roseau River WMA, northern Minnesota, when fall-staging geese were close to a source of lead shot in Manitoba. Proportion of birds exposed to lead dropped to <2% at Lac Qui Parle WMA, Minnesota, a steel shot zone since 1980. On the wintering grounds at Swan Lake National Wildlife Refuge in Missouri, 4.9% of all geese showed exposure to lead before the hunting season. Lead exposure rose to 10.0% after hunting ended and then decreased to 5.2% in late winter. Incidence of lead shot in gizzards and concentrations of lead in livers supported blood assay data. Soil samples indicated that lead shot continues to be available to geese at Swan Lake, even though the area was established as a non-toxic shot zone in 1978. Steel shot zones have reduced lead exposure in the Eastern Prairie Population, but lead shot persists in the environment and continues to account for lead exposure and mortality in Eastern Prairie Population Canada geese.

Phenotypic flexibility at the molecular and organismal level allows desert-dwelling rodents to cope with seasonal water availability.

PubMed

Gallardo, Pedro A; Cortes, Arturo; Bozinovic, Francisco

2005-01-01

We examined the phenotypic flexibility of field urine osmolality (Uosm) in response to seasonal rainfall and the experimental expression of renal aquaporins (AQPs) in the leaf-eared mouse Phyllotis darwini, a South American desert-dwelling rodent, through an integrative study at both the cellular and the organismal level. Field Uosm was higher in summer than in winter. Fall and winter Uosm were not significantly different. During a rainy year, winter Uosm was 2,140 +/- 82.3 mOsm kg(-1); the corresponding value in a dry year was 2,569 +/- 61.3 mOsm kg(-1). During the summer, the mean Uosm in a rainy year was 3,321 +/- 71.5 mOsm kg(-1), and in a dry year it was 3,604 +/- 107.2 mOsm kg(-1). The distribution of AQP-2, AQP-3, and AQP-4 was similar to that described for mouse and rat kidneys and confined to principal cells in cortex and inner medullary collecting-duct cells. AQP-4 immunoreactivity was unaltered by the state of water balance. Relative to water loading, dehydration induced an increase in AQP-2 immunoreactivity and protein abundance. Although more discrete, AQP-3 immunolabeling was also increased by dehydration. We now reveal how the integration of flexible renal mechanisms acting at the cellular and organismal level allow a small desert-dwelling mammal to cope with seasonal and yearly (El Nino) water availability in its semiarid habitat.

Dynamic and thermodynamic impacts of the winter Arctic Oscillation on summer sea ice extent.

NASA Astrophysics Data System (ADS)

Park, H. S.; Stewart, A.

2017-12-01

Arctic summer sea ice extent exhibits substantial interannual variability, as is highlighted by the remarkable recovery in sea ice extent in 2013 following the record minimum in the summer of 2012. Here, we explore the mechanism via which Arctic Oscillation (AO)-induced ice thickness changes impact summer sea ice, using observations and reanalysis data. A positive AO weakens the basin-scale anticyclonic sea ice drift and decreases the winter ice thickness by 15cm and 10cm in the Eurasian and the Pacific sectors of the Arctic respectively. Three reanalysis datasets show that the (upward) surface heat fluxes are reduced over wide areas of the Arctic, suppressing the ice growth during the positive AO winters. The winter dynamic and thermodynamic thinning preconditions the ice for enhanced radiative forcing via the ice-albedo feedback in late spring-summer, leading to an additional 8-10 cm of thinning over the Pacific sector of the Arctic. Because of these winter AO-induced dynamic and thermodynamics effects, the winter AO explains about 22% (r = -0.48) of the interannual variance of September sea ice extent from year 1980 to 2015.

Healthcare seeking behavior of patients with influenza like illness: comparison of the summer and winter influenza epidemics.

PubMed

Meng, Huaiqing; Liao, Qiuyan; Suen, Lorna Kwai Ping; O'Donoghue, Margaret; Wong, Chit Ming; Yang, Lin

2016-09-20

Influenza often causes winter and summer epidemics in subtropical regions, but few studies have investigated the difference in healthcare seeking behavior of patients with influenza-like illness (ILI) between these two epidemics. Household telephone surveys were conducted using random digit dialing in Hong Kong during July-August 2014 and March-April 2015. One adult from each household was interviewed for ILI symptoms and associated healthcare seeking behaviour of themselves and one child in the household (if any), during the preceding 30 days. Healthcare seeking behavior of respondents with self-reported ILI was compared between summer and winter influenza. Logistic regression was used to explore the factors associated with healthcare seeking behavior. Among 516 and 539 adult respondents in the summer and winter surveys, 22.6 and 38.0 % reported ILI symptoms, and 40.9 and 46.8 % of them sought medical care, respectively. There was no significant difference in healthcare seeking behavior between the summer and winter epidemics, except a higher proportion of self-medication in summer in the adult respondents. Among 155 and 182 children reported by the adults in both surveys, the proportion of self-reported ILI was 32.9 and 40.1 % in the summer and winter surveys, respectively. Of these children, 47.1 and 56.2 % were brought for medical consultation in summer and winter, respectively. Women, adults with diabetes and those with symptoms of cough, shortness of breath, and runny nose were more likely to seek medical consultations for ILI symptoms. The factors associated with seeking medical consultations in children with ILI symptoms included being female, age under 10 years, and with symptoms of sore throat or vomiting. Those older than 60 years were less likely to self-medicate, whereas regular smokers and those with symptom of sore throat were more likely to do so. Healthcare seeking behavior of the general public was not significantly different between these two epidemics. However ILI was associated with increased healthcare utilization in both winter and summer epidemics in Hong Kong.

Northern Galápagos Corals Reveal Twentieth Century Warming in the Eastern Tropical Pacific

NASA Astrophysics Data System (ADS)

Jimenez, Gloria; Cole, Julia E.; Thompson, Diane M.; Tudhope, Alexander W.

2018-02-01

Models and observations disagree regarding sea surface temperature (SST) trends in the eastern tropical Pacific. We present a new Sr/Ca-SST record that spans 1940-2010 from two Wolf Island corals (northern Galápagos). Trend analysis of the Wolf record shows significant warming on multiple timescales, which is also present in several other records and gridded instrumental products. Together, these data sets suggest that most of the eastern tropical Pacific has warmed over the twentieth century. In contrast, recent decades have been characterized by warming during boreal spring and summer (especially north of the equator), and subtropical cooling during boreal fall and winter (especially south of the equator). These SST trends are consistent with the effects of radiative forcing, mitigated by cooling due to wind forcing during boreal winter, as well as intensified upwelling and a strengthened Equatorial Undercurrent.

Seasonal dynamics of bacterial biomass and production in a coastal arctic ecosystem: Franklin Bay, western Canadian Arctic

NASA Astrophysics Data System (ADS)

Garneau, Marie-Ã. Ve; Roy, SéBastien; Lovejoy, Connie; Gratton, Yves; Vincent, Warwick F.

2008-07-01

The Canadian Arctic Shelf Exchange Study (CASES) included the overwintering deployment of a research platform in Franklin Bay (70°N, 126°W) and provided a unique seasonal record of bacterial dynamics in a coastal region of the Arctic Ocean. Our objectives were (1) to relate seasonal bacterial abundance (BA) and production (BP) to physico-chemical characteristics and (2) to quantify the annual bacterial carbon flux. BA was estimated by epifluorescence microscopy and BP was estimated from 3H-leucine and 3H-thymidine assays. Mean BA values for the water column ranged from 1.0 (December) to 6.8 × 105 cells mL-1 (July). Integral BP varied from 1 (February) to 80 mg C m-2 d-1 (July). During winter-spring, BP was uncorrelated with chlorophyll a (Chl a), but these variables were significantly correlated during summer-autumn (rs = 0.68, p < 0.001, N = 38), suggesting that BP was subject to bottom-up control by carbon supply. Integrated BP data showed three distinct periods: fall-winter, late winter-late spring, and summer. A baseline level of BB and BP was maintained throughout late winter-late spring despite the persistent cold and darkness, with irregular fluctuations that may be related to hydrodynamic events. During this period, BP rates were correlated with colored dissolved organic matter (CDOM) but not Chl a (rs BP.CDOM∣Chl a = 0.20, p < 0.05, N = 176). Annual BP was estimated as 6 g C m-2 a-1, implying a total BP of 4.8 × 1010 g C a-1 for the Franklin Bay region. These results show that bacterial processes continue throughout all seasons and make a large contribution to the total biological carbon flux in this coastal arctic ecosystem.

Outdoor temperature, blood pressure, and cardiovascular disease mortality among 23 000 individuals with diagnosed cardiovascular diseases from China.

PubMed

Yang, Ling; Li, Liming; Lewington, Sarah; Guo, Yu; Sherliker, Paul; Bian, Zheng; Collins, Rory; Peto, Richard; Liu, Yun; Yang, Rong; Zhang, Yongrui; Li, Guangchun; Liu, Shumei; Chen, Zhengming

2015-05-14

Blood pressure is a major cause of cardiovascular disease (CVD) and both may increase as outdoor temperatures fall. However, there are still limited data about seasonal variation in blood pressure and CVD mortality among patients with prior-CVD. We analysed data on 23 000 individuals with prior-CVD who were recruited from 10 diverse regions into the China Kadoorie Biobank during 2004-8. After 7 years of follow-up, 1484 CVD deaths were recorded. Baseline survey data were used to assess seasonal variation in systolic blood pressure (SBP) and its association with outdoor temperature. Cox regression was used to examine the association of usual SBP with subsequent CVD mortality, and seasonal variation in CVD mortality was assessed by Poisson regression. All analyses were adjusted for age, sex, and region. Mean SBP was significantly higher in winter than in summer (145 vs. 136 mmHg, P < 0.001), especially among those without central heating. Above 5°C, each 10°C lower outdoor temperature was associated with 6.2 mmHg higher SBP. Systolic blood pressure predicted subsequent CVD mortality, with each 10 mmHg higher usual SBP associated with 21% (95% confidence interval: 16-27%) increased risk. Cardiovascular disease mortality varied by season, with 41% (21-63%) higher risk in winter compared with summer. Among adult Chinese with prior-CVD, there is both increased blood pressure and CVD mortality in winter. Careful monitoring and more aggressive blood pressure lowering treatment in the cold months are needed to help reduce the winter excess CVD mortality in high-risk individuals. © The Author 2015. Published by Oxford University Press on behalf of the European Society of Cardiology.

Fall season atypically warm weather event leads to substantial CH4 loss in Arctic ecosystems?

NASA Astrophysics Data System (ADS)

Zona, Donatella; Moreaux, Virginie; Liljedahl, Anna; Losacco, Salvatore; Murphy, Patrick; Oechel, Walter

2014-05-01

In the last century (during 1875-2008) high-latitudes are warming at a rate of 1.360C century-1, almost 2 times faster than the Northern Hemisphere trend (Bekryaev et al., 2010). This warming has been more intense outside of the summer season, with anomalies of 1.09, 1.59, 1.730C in the fall, winter, and spring season respectively (Bekryaev et al., 2010). This substantial temperature anomalies have the potential to increase the emission of greenhouse gas (CO2 and CH4) fluxes from arctic tundra ecosystems. In particular, CH4 emissions, which are primarily controlled by temperature (in addition to water table), can steeply increase with warming. Despite the potential relevance of CH4 emissions, very few measurements have been performed outside of the growing season across the entire Arctic, due to logistic constrains. Importantly, no flux measurements achieved a temporal and spatial data coverage sufficient to estimate with confidence an annual CH4 emissions from tundra ecosystem in Alaska, and its sensitivity to warming. Fall 2013 was unusually warm in central and northern Alaska. Following a relatively warm summer with dramatically above-average rainfall, the October mean monthly temperatures was the 4th and top warmest in Barrow (1949-2013) and Ivotuk (1998-2013), respectively. As we just upgraded several eddy covariance towers to measure CO2 and CH4 fluxes year-round, the atypical weather conditions of fall 2013 represented a unique chance for testing the sensitivity of CH4 loss to these atypically warm temperatures. All our sites across a latitudinal gradient (from the northern site, Barrow, to the southern site, Ivotuk), presented substantial CH4 loss in the fall. Importantly, in two of these sites (Barrow, Ivotuk) where the fall weather was substantially warmer than the long term trend, fall CH4 emission represented between 44-63% of the June-November cumulative emission. Surprisingly, in the southernmost site (Ivotuk), when the temperature anomaly was the highest, cumulative fall CH4 emission outpaced even the summer emission. This shows the sensitivity of CH4 loss to abnormal conditions, and the importance of fall periods for the annual CH4 budget in these Arctic ecosystems. Bekryaev, R. V., I. V. Polyakov, and V. A. Alexeev. 2010. Role of polar amplification in long-term surface air temperature variations and modern Arctic warming. Journal of Climate 23(14):3888-3906.

Seasonal variations of severe hypoglycemia in patients with type 1 diabetes mellitus, type 2 diabetes mellitus, and non-diabetes mellitus: clinical analysis of 578 hypoglycemia cases.

PubMed

Tsujimoto, Tetsuro; Yamamoto-Honda, Ritsuko; Kajio, Hiroshi; Kishimoto, Miyako; Noto, Hiroshi; Hachiya, Remi; Kimura, Akio; Kakei, Masafumi; Noda, Mitsuhiko

2014-11-01

Blood glucose control in patients with diabetes mellitus (DM) is reportedly influenced by the seasons, with hemoglobin A1c (HbA1c) levels decreasing in the summer or warm season and increasing in the winter or cold season. In addition, several studies have shown that sepsis is also associated with the seasons. Although both blood glucose control and sepsis can strongly affect the occurrence of severe hypoglycemia, few studies have examined the seasonal variation of severe hypoglycemia. The aim of the present study is to examine the association between severe hypoglycemia and the seasons in patients with type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), and non-diabetes mellitus (non-DM). We retrospectively reviewed all the patients with severe hypoglycemia at a national center in Japan between April 1, 2006 and March 31, 2012. A total of 57,132 consecutive cases that had visited the emergency room by ambulance were screened, and 578 eligible cases of severe hypoglycemia were enrolled in this study. The primary outcome was to assess the seasonality of severe hypoglycemia. In the T1DM group (n  =  88), severe hypoglycemia occurred significantly more often in the summer than in the winter (35.2% in summer vs 18.2% in winter, P  =  0.01), and the HbA1c levels were highest in the winter and lowest in the summer (9.1% [7.6%-10.1%] in winter vs 7.7% [7.1%-8.3%] in summer, P  =  0.13). In the non-DM group (n  =  173), severe hypoglycemia occurred significantly more often in the winter than in the summer (30.6% in winter vs 19.6% in summer, P  =  0.01), and sepsis as a complication occurred significantly more often in winter than in summer (24.5% in winter vs 5.9% in summer, P  =  0.02). In the T2DM group (n  =  317), the occurrence of severe hypoglycemia and the HbA1c levels did not differ significantly among the seasons. The occurrence of severe hypoglycemia might be seasonal and might fluctuate with temperature changes. Patients should be treated more carefully during the season in which severe hypoglycemia is more common.

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

PubMed Central

Currie, Robert W.

2016-01-01

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 higher DWV was associated with colony death as did high SBV for spring-collected samples. PMID:27448049

Characteristics of patients with otherwise typical winter depression, but with incomplete summer remission.

PubMed

Lingjaerde, O; Regine Føreland, A

1999-04-01

Seasonal affective disorder, winter depression type (WD-SAD), is characterized by recurring autumn/winter depression with full remission or hypomania/mania in summer. However, some patients have an otherwise typical WD but with incomplete summer remission. We wanted to elucidate in what other respects such patients differ from typical WD-SAD patients. 14 patients meeting DSM-III-R criteria for Seasonal Pattern except for incomplete summer remission (ISR), were compared with 144 patients meeting the full criteria, including complete summer remission (CSR), with regard to demography, illness history, clinical symptoms, and response to light treatment. In comparison with the CSR group, the ISR group had a longer duration of illness, more often used antidepressants, and improved significantly less after treatment with bright light for 6 days, whereas the symptomatology in winter (Montgomery-Asberg Depression Rating Scale plus hypersomnia, hyperphagia, and carbohydrate craving) was similar in the two groups. The ISR group was small, and the severity of their summer depression could only be assessed retrospectively. Patients with otherwise typical WD but with incomplete summer remission respond poorly to light treatment. Full summer remission should be retained as a criterion for WD-SAD.

Cloud-to-ground lightning flash characteristics from June 1984 through May 1985

NASA Technical Reports Server (NTRS)

Orville, Richard E.; Weisman, Robert A.; Pyle, Richard B.; Henderson, Ronald W.; Orville, Richard E., Jr.

1987-01-01

A magnetic direction-finding network for the detection of lightning cloud-to-ground strikes has been installed along the east coast of the United States. Time, location, flash polarity, stroke count, and peak signal amplitude are recorded in real time. The data were recorded from Maine to North Carolina and as far west as Ohio; analyses were restricted to flashes within 300 km of a direction finder. Measurements of peak signal strength have been obtained from 720,284 first return strokes lowering negative charge. The resulting distribution indicates that few negative strokes have peak currents exceeding 100 kA. Measurements have also been obtained of peak signal strength from 17,694 first return strokes lowering positive charge. These strokes have a median peak current of 45 kA, with some peak currents reaching 300-400 kA. The median peak signal strength and the peak current, double from summer to winter for both negative and positive first return strokes. The polarity of ground flashes is observed to be less than 5 percent positive throughout the summer and early fall, then increases to over 50 percent during the winter, and returns to less than 10 percent in early spring. The percent of positive flashes with one stroke is observed to be approximately 90 percent throughout the year. The percent of negative flashes with one stroke is observed to increase from 40 percent in the summer to approximately 80 percent in January, returning to less than 50 percent in the spring.

Seasonal and spatial distributions of atmospheric polychlorinated naphthalenes in Shanghai, China.

PubMed

Die, Qingqi; Nie, Zhiqiang; Fang, Yanyan; Yang, Yufei; Gao, Xingbao; Tian, Yajun; He, Jie; Liu, Feng; Huang, Qifei; Tian, Shulei

2016-02-01

Air samples were collected in Shanghai during summer and winter 2013, and the gas and particulate concentrations of polychlorinated naphthalenes (PCNs) were measured. All 75 congeners were quantified and the corresponding toxic equivalents (TEQs) were calculated. PCN concentrations were higher in summer than winter, at 8.22-102 pg/m(3) (average of 61.3 pg/m(3)) in summer and 16.5-61.1 pg/m(3) (average of 37.7 pg/m(3)) in winter. Their seasonal TEQ values were in contrast, at 1.35-7.31 fg/m(3) (average of 3.84 fg/m(3)) in summer and 4.08-23.3 fg/m(3) (average of 8.80 fg/m(3)) in winter, because of the seasonal change in congener profiles. Tri-CNs were the predominant homologs in both the summer and winter samples. However, the major congeners in summer were PCNs containing less chlorine, but these decreased over winter. Air mass back trajectories suggested that wind direction over various sites was similar in the summer and winter seasons, yet there were clear seasonal variations in atmospheric PCN concentrations. Ratios of several characteristic congeners were calculated and the results indicated that the ratios varied only to a limited extent with PCN emissions profile from industrial thermal sources, but varied strongly with profiles of technical PCN and PCN contaminants in polychlorinated biphenyl mixtures. The results of principal component analysis suggest that local industrial thermal emissions (thermal processes containing waste incineration and secondary metal smelting processes) still play a considerable role in influencing the atmospheric PCNs in Shanghai. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Effects of irrigation using dairy effluent on grain yield, phosphorus utilization and distribu- tion in soil profile in winter wheat-summer maize rotation system].

PubMed

Du, Hui-ying; Feng, Jie; Guo, Hai-gang; Wang, Feng; Zhang, Ke-qiang

2015-08-01

Field experiments of winter wheat-summer maize rotation were conducted in North China Plain irrigation area to explore the effects of wheat season irrigation with dairy effluent on grain yield, phosphorus uptake, accumulative phosphorus usage efficiency and phosphorus accumulation in soil. The results showed that the irrigation with dairy effluent significantly improved the yields of winter wheat and summer maize. With the increasing of P2O5 carried by dairy effluent into soil, winter wheat yield increased at first and then decreased. When the P2O5 increased 137 kg · hm(-2), winter wheat yield increased to the maximum (7646.4 kg · hm(-2)) and the phosphorus utilization rate was the highest (24.8%). But excessive phosphorus decreased the winter wheat yield and phosphorus utilization efficiency. Summer maize yield and phosphorus uptake increased with the increase of P2O5 carried by dairy effluent. The summer maize yield increased by 2222.4-2628.6 kg · hm(-2) and the phosphorus uptake increased by 13.9-21.1 kg · hm(-2) in contrast to the control (CK). Under conventional phosphorus fertilization at 88 kg · hm(-2), and the summer maize yield increased by 2235.0 kg · hm(-2) compared with CK. As the time of irrigation with dairy effluent increasing, the grain yield increased more significantly. The cumulative phosphorus utilization in this rotation system increased year by year. After six seasons of crop harvest, the cumulative phosphorus utilization rate increased into 40.0%-47.7%. Under the experimental condition, two times of irrigation with the dairy effluents in the winter wheat-summer maize rotation system was the best operating mode.

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

NASA Astrophysics Data System (ADS)

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.

Source Apportionment of Volatile Organic Compounds in an Urban Environment at the Yangtze River Delta, China.

PubMed

An, Junlin; Wang, Junxiu; Zhang, Yuxin; Zhu, Bin

2017-04-01

Volatile organic compounds (VOCs) were collected continuously during June-August 2013 and December 2013-February 2014 at an urban site in Nanjing in the Yangtze River Delta. The positive matrix factorization receptor model was used to analyse the sources of VOCs in different seasons. Eight and seven sources were identified in summer and winter, respectively. In summer and winter, the dominant sources of VOCs were vehicular emissions, liquefied petroleum gas/natural gas (LPG/NG) usage, solvent usage, biomass/biofuel burning, and industrial production. In summer, vehicular emissions made the most significant contribution to ambient VOCs (38%), followed by LPG/NG usage (20%), solvent usage (19%), biomass/biofuel burning (13%), and industrial production (10%). In winter, LPG/NG usage accounted for 36% of ambient VOCs, whereas vehicular emissions, biomass/biofuel burning, industrial production and solvent usage contributed 30, 18, 9, and 6%, respectively. The contribution of LPG/NG usage in winter was approximately four times that in summer, whereas the contribution from biomass/biofuel burning in winter was more than twice that in summer. The sources related to vehicular emissions and LPG/NG usages were important. Using conditional probability function analysis, the VOC sources were mainly associated with easterly, northeasterly and southeasterly directions, pointing towards the major expressway and industrial area. Using the propylene-equivalent method, paint and varnish (23%) was the highest source of VOCs in summer and biomass/biofuel burning (36%) in winter. Using the ozone formation potential method, the most important source was biomass/biofuel burning (32% in summer and 47% in winter). The result suggests that the biomass/biofuel burning and paint and varnish play important roles in controlling ozone chemical formation in Nanjing.

Seasonality in the tropical Atlantic: an 800-year record of seasonally-representative Mg/Ca data from the Cariaco Basin

NASA Astrophysics Data System (ADS)

Black, D. E.; Rahman, S.; Wurtzel, J.; Thunell, R.; Mauer, B.; Tappa, E. J.

2009-12-01

The Cariaco Basin, Venezuela is well-positioned to record a detailed history of surface ocean changes along the southern margin of the Caribbean and the tropical Atlantic. Varved, high deposition rate sediments deposited under anoxic conditions and an abundance of well-preserved microfossils result in one of the few marine records capable of preserving evidence of interannual- to decadal-scale climate variability in the tropical Atlantic. Boreal winter/spring sea surface temperatures (SST) spanning the last eight centuries have previously been reconstructed using Mg/Ca measurements on the planktic foraminifer Globigerina bulloides. Here we present the complementary record using Globigerinoides ruber (pink), a summer/fall indicator. Globigerinoides ruber Mg/Ca values are generally greater than those of G. bulloides from the same sample, reflecting warmer calcification temperatures. Both species’ records display similar long-term trends, yet there are some distinctive differences. The Medieval Warm Period (MWP) and Little Ice Age (LIA) as distinctly separate climate events are more apparent in the G. ruber record than that of G. bulloides. Additionally, greater variability in the G. ruber data may indicate a stronger than expected bias from productivity during the local upwelling season. As G. bulloides and pink G. ruber are thought to be winter/spring and summer/fall SST indicators, respectively (albeit with the potential upwelling season bias), the intersample differences between the two records can potentially be interpreted as a record of seasonality. Our seasonality reconstruction shows a distinctive oscillation of 4 °C with a period of approximately 200 years. The proxy seasonality is slightly less than what has been instrumentally measured (5 to 6 °C) over the last 15 years, and does not appear related to or affected by the MWP or LIA events.

Monitoring the wild black bear's reaction to human and environmental stressors

PubMed Central

2011-01-01

Background Bears are among the most physiologically remarkable mammals. They spend half their life in an active state and the other half in a state of dormancy without food or water, and without urinating, defecating, or physical activity, yet can rouse and defend themselves when disturbed. Although important data have been obtained in both captive and wild bears, long-term physiological monitoring of bears has not been possible until the recent advancement of implantable devices. Results Insertable cardiac monitors that were developed for use in human heart patients (Reveal® XT, Medtronic, Inc) were implanted in 15 hibernating bears. Data were recovered from 8, including 2 that were legally shot by hunters. Devices recorded low heart rates (pauses of over 14 seconds) and low respiration rates (1.5 breaths/min) during hibernation, dramatic respiratory sinus arrhythmias in the fall and winter months, and elevated heart rates in summer (up to 214 beats/min (bpm)) and during interactions with hunters (exceeding 250 bpm). The devices documented the first and last day of denning, a period of quiescence in two parturient females after birthing, and extraordinary variation in the amount of activity/day, ranging from 0 (winter) to 1084 minutes (summer). Data showed a transition toward greater nocturnal activity in the fall, preceding hibernation. The data-loggers also provided evidence of the physiological and behavioral responses of bears to our den visits to retrieve the data. Conclusions Annual variations in heart rate and activity have been documented for the first time in wild black bears. This technique has broad applications to wildlife management and physiological research, enabling the impact of environmental stressors from humans, changing seasons, climate change, social interactions and predation to be directly monitored over multiple years. PMID:21849079

The First Twenty Years (1994 2014) of Ozone Soundings from Rapa Nui (27 deg S, 109 deg W, 51 m a.s.l.)

NASA Technical Reports Server (NTRS)

Gallardo, Laura; Henriquez, Adolfo; Thompson, Anne M.; Rondanelli, Roberto; Carrasco, Jorge; Orfanoz-Cheuquelaf, Andrea; Velasquez, Patricio

2017-01-01

Ozone (O3) soundings have been performed on Easter Island or Rapa Nui (27 8S, 109 8W, 51 m a.s.l.) since 1994 as part of the Global Atmospheric Watch Programme of the World Meteorological Organization. In this work, we analyze 260 soundings compiled over the period 19942014, and make the data available for the international community. We characterize O3 profiles over this remote area of the Pacific by means of statistical analyses that consider, on the one hand, a traditional climatology that describes the data in terms of seasonal cycles based on monthly averages and, on the other hand, a process-oriented analysis based on self-organizing maps. Our analyses show the influence of both tropical and subtropical/mid-latitude air masses at Rapa Nui. The former occurs in summer and fall when convective conditions prevail, and the latter in late winter and spring when subsiding conditions are recurrent. The occurrence of stratospheric intrusions in late winter and spring in connection with deep troughs and the presence of the subtropical jet stream is also apparent in the data set. The tropospheric ozone column is in good agreement with the corresponding data derived from satellites but with a systematic overestimate of summer and fall values. There is evidence of an upward trend in ozone near the surface, which suggests the impact of local pollution. We look forward to an enhancement of the Rapa Nui observing site, given its location that offers a privileged position to observe climate change over the sparsely sampled and vast South Pacific Ocean.

Does the Dietary Pattern of Shanghai Residents Change across Seasons and Area of Residence: Assessing Dietary Quality Using the Chinese Diet Balance Index (DBI)

PubMed Central

Zang, Jiajie; Yu, Huiting; Zhu, Zhenni; Lu, Ye; Liu, Changhe; Yao, Chunxia; Bai, Pinqing; Guo, Changyi; Jia, Xiaodong; Zou, Shurong; Wu, Fan

2017-01-01

Background: Few studies have applied the Chinese Diet Balance Index (DBI) in evaluating dietary quality across seasons. Method: The Shanghai Diet and Health Survey (SDHS) included 1680 participants from all districts of Shanghai from 2012 to 2013. Dietary data were obtained using three-day 24-h recall in spring, summer, fall, and winter. Higher bound score (HBS), lower bound score (LBS) and diet quality distance (DQD) were calculated according to compliance with the dietary guidelines and based on the recommendations for consumption within the main food groups. HBS, LBS, and DQD represent over-intake, under-intake, and overall imbalance of the diet, respectively. Results: 836 males and 844 females were included. The HBS indicated that 10.08%, 11.84%, 10.31%, and 12.73% people have moderate or high levels of over-intake of food in spring, summer, fall, and winter, respectively; and 74.04%, 37.61%, 53.09%, and 42.72% people have moderate or high levels of deficit food intake for each of the four seasons. The mean HBS and LBS among the four seasons were statistically significant difference (p < 0.001). The mean (SD) DQD was 43.27 (10.21), 35.67 (9.71), 39.19 (9.36), and 36.84 (9.45) in each season. A multivariable model showed statistically significant differences in DQD according to age, gender, occupational status, education, smoking, drinking status, season, and residency (p < 0.001). Conclusion: An unbalanced diet is common among people living in Shanghai. Seasonality and area of residence were found to be two significant predictors. Strengthening the accessibility and the supply of food across seasons and regions should be considered. PMID:28282864

On the Role of SST Forcing in the 2011 and 2012 Extreme U.S. Heat and Drought: A Study in Contrasts

NASA Technical Reports Server (NTRS)

Wang, Hailan; Schubert, Siegfried; Koster, Randal; Ham, Yoo-Geun; Suarez, Max

2013-01-01

This study compares the extreme heat and drought that developed over the United States in 2011 and 2012 with a focus on the role of SST forcing. Experiments with the NASA GEOS-5 atmospheric general circulation model show that the winter/spring response over the U.S. to the Pacific SST is remarkably similar for the two years despite substantial differences in the tropical Pacific SST. As such, the pronounced winter and early spring temperature differences between the two years (warmth confined to the south in 2011 and covering much of the continent in 2012) primarily reflect differences in the contributions from the Atlantic and Indian Oceans, with both acting to cool the east and upper mid-west during 2011, while during 2012 the Indian Ocean reinforced the Pacific-driven continental-wide warming and the Atlantic played a less important role. During late spring and summer of 2011 the tropical Pacific SST force a continued warming and drying over the southern U.S., though considerably weaker than observed. Nevertheless, the observed anomalies fall within the models intra-ensemble spread. In contrast, the rapid development of intense heat and drying over the central U.S. during June and July of 2012 falls outside the models intra-ensemble spread. The response to the SST (a northward expansion of a modest summer warming linked to the Atlantic) gives little indication that 2012 would produce record-breaking precipitation deficits and heat in the central Great Plains. A diagnosis of the 2012 observed circulation anomalies shows that the most extreme heat and drought was tied to the development of a stationary Rossby wave and an associated anomalous upper tropospheric high maintained by weather transients.

Cool seasons are related to poor prognosis in patients with infective endocarditis

NASA Astrophysics Data System (ADS)

Chen, Su-Jung; Chao, Tze-Fan; Lin, Yenn-Jiang; Lo, Li-Wei; Hu, Yu-Feng; Tuan, Ta-Chuan; Hsu, Tsui-Lieh; Yu, Wen-Chung; Leu, Hsin-Bang; Chang, Shih-Lin; Chen, Shih-Ann

2012-09-01

Many cardiac diseases demonstrate seasonal variations in the incidence and mortality. This study was designed to investigate whether the mortality of infective endocarditis (IE) was higher in cool seasons and to evaluate the effects of cool climate for IE. We enrolled 100 IE patients with vegetations in our hospital. The temperatures of the IE episodes were defined as the monthly average temperatures of the admission days. The average temperatures in the cool (fall/winter) and warm seasons (spring/summer) were 19.2°C and 27.6°C, respectively. In addition, patients admitted with the diagnosis of IE were identified from the National Health Insurance Research Database (NHIRD) and the in-hospital mortality rates in cool and warm seasons were compared to validate the findings derived from the data of our hospital. The mortality rate for IE was significantly higher in fall/winter than in spring/summer which presents consistently in the patient population of our hospital (32.7% versus 12.5%, p = 0.017) and from NHIRD (10.4% versus 4.6%, p = 0.019). IE episodes which occurred during cool seasons presented with a higher rate of heart failure (44.2% versus 22.9%, p = 0.025) and D-dimer level (5.5 ± 3.8 versus 2.4 ± 1.8 μg/ml, p = 0.017) at admission than that of warm seasons. These results may reflect the impact of temperatures during the pre-hospitalized period on the disease process. In the multivariate analysis, Staphylococcal infection, left ventricular hypertrophy, left ventricular systolic dysfunction and temperature were the independent predictors of mortalities in IE patients.

Seasonal oxygen and carbon isotope variability in euthecosomatous pteropods from the Sargasso Sea

NASA Astrophysics Data System (ADS)

Juranek, L. W.; Russell, A. D.; Spero, H. J.

2003-02-01

We examine seasonal variations in the stable carbon and oxygen isotopic composition of individual shells of the pteropods Limacina inflata and Styliola subula, collected from Oceanic Flux Program sediment traps (at 500 m depth) near Bermuda in the western Sargasso Sea. Calcification depths estimated from L. inflata δ18O vary between 200 and 650 m in late winter and spring, and between 50 and 250 m in late summer and fall. S. subula shows similar seasonal variability with calcification depths between 250 and 600 m in late winter and spring and 50-400 m in late summer and fall. These results suggest that both species calcify across a greater range of depths than indicated by previous geochemical studies. Furthermore, the data indicate that these species change their calcification depth in conjunction with changes in thermal stratification of the water column. Pteropod shell δ13C values vary inversely with δ13C DIC but show a positive correlation with seawater [CO 32-] and temperature after depth differences in δ13C DIC are accounted for. We hypothesize that either the influence of temperature on metabolic CO 2 incorporation during shell growth and/or the influence of ambient [CO 32-] on shell geochemistry can explain these relationships. Taken together, the individual shell δ18O and δ13C data suggest that shell calcification, and by inference the life cycle, of these pteropods is several months or less. Individual pteropod shell analyses have potential for contributing to our understanding of the environmental parameters that play a role in seasonal calcification depth shifts, as well as to our knowledge of past upper ocean thermal structure.

Seasonal associations and atmospheric transport distances of fungi in the genus Fusarium collected with unmanned aerial vehicles and ground-based sampling devices

NASA Astrophysics Data System (ADS)

Lin, Binbin; Ross, Shane D.; Prussin, Aaron J.; Schmale, David G.

2014-09-01

Spores of fungi in the genus Fusarium may be transported through the atmosphere over long distances. New information is needed to characterize seasonal trends in atmospheric loads of Fusarium and to pinpoint the source(s) of inoculum at both local (farm) and regional (state or country) scales. We hypothesized that (1) atmospheric concentrations of Fusarium spores in an agricultural ecosystem vary with height and season and (2) transport distances from potential inoculum source(s) vary with season. To test these hypotheses, spores of Fusarium were collected from the atmosphere in an agricultural ecosystem in Blacksburg, VA, USA using a Burkard volumetric sampler (BVS) 1 m above ground level and autonomous unmanned aerial vehicles (UAVs) 100 m above ground level. More than 2200 colony forming units (CFUs) of Fusarium were collected during 104 BVS sampling periods and 180 UAV sampling periods over four calendar years (2009-2012). Spore concentrations ranged from 0 to 13 and 0 to 23 spores m-3 for the BVS and the UAVs, respectively. Spore concentrations were generally higher in the fall, spring, and summer, and lower in the winter. Spore concentrations from the BVS were generally higher than those from the UAVs for both seasonal and hourly collections. A Gaussian plume transport model was used to estimate distances to the potential inoculum source(s) by season, and produced mean transport distances of 1.4 km for the spring, 1.7 km for the summer, 1.2 km for the fall, and 4.1 km for the winter. Environmental signatures that predict atmospheric loads of Fusarium could inform disease spread, air pollution, and climate change.

Seasonal variation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa Island, Japan

NASA Astrophysics Data System (ADS)

Handa, D.; Nakajima, H.; Nakaema, F.; Arakaki, T.; Tanahara, A.

2008-12-01

The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the air pollution transported from Asian continent has gained a special attention in Japan. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asian atmospheric aerosols because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. In 2005, Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) was established by the National Institute for Environmental Studies (NIES) at the northern tip of Okinawa Island, Japan to monitor the air quality of Asia. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon in the bulk aerosols collected at the CHAAMS, using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions.

Nine years of mass transport data in the eastern boundary of the North Atlantic Subtropical Gyre

NASA Astrophysics Data System (ADS)

Fraile-Nuez, Eugenio; MachíN, Francisco; VéLez-Belchí, Pedro; López-Laatzen, Federico; Borges, Rafael; BeníTez-Barrios, Verónica; HernáNdez-Guerra, Alonso

2010-09-01

One of the longest current meter time series in the Lanzarote Passage in the eastern boundary of the North Atlantic Subtropical Gyre has been used to determine and quantify the 9-year mean transport, the inter-annual and seasonal mass transport variability for the three water masses present in the area. Results show North Atlantic Central Water (NACW) flowing southward in the upper levels with a mean mass transport of -0.81 ± 1.48 Sv, Antarctic Intermediate Water (AAIW) flowing northward at intermediate levels with a mean transport of +0.09 ± 0.57 Sv and Mediterranean Water (MW) flowing southward in the deep part of the passage with a mean transport of -0.05 ± 0.17 Sv. Harmonic and wavelet analysis show the presence of a seasonal pattern in the passage for the three water masses. A maximum southward transport in winter and spring has been observed for the NACW followed by a minimum in summer and fall. Near zero values during winter and spring are found for AAIW, with a maximum northward value in summer and a negative value in fall, when this water mass reverses its flow. MW has a similar seasonal pattern to NACW. The vertical structure in the Lanzarote Passage can be approximated by four significant oscillatory modes which cumulatively explain 86.4% of the variance. The strong transport fluctuation found at the seasonal and inter-annual timescales demonstrates that the Eastern Boundary Current transport has a strong impact on meridional overturning estimates, thus indicating that to understand Meridional Overturning Circulation variability, these transport estimates at the eastern Atlantic margin are necessary.

Stable isotope composition of water vapor in the atmospheric boundary layer above the forests of New England

NASA Astrophysics Data System (ADS)

He, Hui; Smith, Ronald B.

1999-05-01

Water vapor at multiple levels was sampled from a light aircraft in the summertime atmospheric boundary layer (ABL) over forested terrain at altitudes up to 3 km. Three sampling flights were carried out under similar weather conditions during the summer to earlier fall period of 1996. The deuterium and oxygen 18 isotope ratios, δD and δ18O, of 24 water vapor and 30 surface water samples were analyzed on a mass spectrometer. The water vapor mixing ratio, Q, at each sampling level was estimated from the amount of the sample collected. The results show constant δD and δ18O in the mixed region of the ABL and sharply decreasing values near the top. Measurement of the ratio of the vertical atmospheric flux of HD16O or H218O to the flux of H216O is of particular interest in hydrology and paleoclimatology studies. This quantity, however, cannot be measured directly at the surface due to the instantaneous turbulent mixing of the evaporating water vapor with the overlying ABL. Using a δ - 1/Q mixing line method, we are able to determine such isotope flux ratios characterizing the two-way exchange between the Earth's surface and the free atmosphere. The varying isotope flux ratios are lighter than expected, but fall into the ranges of the isotope ratios of the winter precipitation in the area. Based on the hypothesis of no fractionation between the soil water and the water vapor transpired by plants, our measurements suggest that late summer transpiration releases soil water which comes from the precipitation that fell during the previous winter. Other explanations are also discussed.

Carbon, water, and energy fluxes in a semiarid cold desert grassland during and following multiyear drought

USGS Publications Warehouse

Bowling, David R.; Bethers-Marchetti, S.; Lunch, C.K.; Grote, E.E.; Belnap, J.

2010-01-01

The net exchanges of carbon dioxide, water vapor, and energy were examined in a perennial Colorado Plateau grassland for 5 years. The study began within a multiyear drought and continued as the drought ended. The grassland is located near the northern boundary of the influence of the North American monsoon, a major climatic feature bringing summer rain. Following rain, evapotranspiration peaked above 8 mm d-1 but was usually much smaller (2-4 mm d-1). Net productivity of the grassland was low compared to other ecosystems, with peak hourly net CO2 uptake in the spring of 4 (mu or u)mol m-2 s-1 and springtime carbon gain in the range of 42 + or - 11 g C m-2 (based on fluxes) to 72 + or - 55 g C m-2 (based on carbon stocks; annual carbon gain was not quantified). Drought decreased gross ecosystem productivity (GEP) and total ecosystem respiration, with a much larger GEP decrease. Monsoon rains led to respiratory pulses, lasting a few days at most, and only rarely resulted in net CO2 gain, despite the fact that C4 grasses dominated plant cover. Minor CO2 uptake was observed in fall following rain. Spring CO2 uptake was regulated by deep soil moisture, which depended on precipitation in the prior fall and winter. The lack of CO2 uptake during the monsoon and the dependence of GEP on deep soil moisture are in contrast with arid grasslands of the warm deserts. Cold desert grasslands are most likely to be impacted by future changes in winter and not summer precipitation.

SEASON OF BIRTH AND RISK OF HODGKIN AND NON-HODGKIN LYMPHOMA

PubMed Central

Crump, Casey; Sundquist, Jan; Sieh, Weiva; Winkleby, Marilyn A.; Sundquist, Kristina

2014-01-01

Infectious etiologies have been hypothesized for Hodgkin and non-Hodgkin lymphoma (HL and NHL) in early life, but findings to date for specific lymphomas and periods of susceptibility are conflicting. We conducted the first national cohort study to examine whether season of birth, a proxy for infectious exposures in the first few months of life, is associated with HL or NHL in childhood through young adulthood. A total of 3,571,574 persons born in Sweden in 1973–2008 were followed up through 2009 to examine the association between season of birth and incidence of HL (943 cases) or NHL (936 cases). We found a sinusoidal pattern in NHL risk by season of birth (P=0.04), with peak risk occurring among birthdates in April. Relative to persons born in fall (September-November), odds ratios for NHL by season of birth were 1.25 (95% CI, 1.04–1.50; P=0.02) for spring (March-May), 1.22 (95% CI, 1.01–1.48; P=0.04) for summer (June-August), and 1.11 (95% CI, 0.91–1.35; P=0.29) for winter (December-February). These findings did not vary by sex, age at diagnosis, or major subtypes. In contrast, there was no seasonal association between birthdate and risk of HL (P=0.78). In this large cohort study, birth in spring or summer was associated with increased risk of NHL (but not HL) in childhood through young adulthood, possibly related to immunologic effects of delayed infectious exposures compared with fall or winter birth. These findings suggest that immunologic responses in early infancy may play an important role in the development of NHL. PMID:24752499

Accumulation of lactate by supercooled hatchlings of the painted turtle (Chrysemys picta): implications for overwinter survival.

PubMed

Hartley, L M; Packard, M J; Packard, G C

2000-02-01

Hatchlings of the North American painted turtle (Chrysemys picta) typically spend their first winter of life inside the shallow, subterranean nest where they completed embryogenesis the preceding summer. Neonates at northern localities consequently may be exposed during winter to subzero temperatures and frozen soil. Hatchlings apparently survive exposure to such conditions by supercooling, but the physiological consequences of this adaptive strategy have not been examined. We measured lactate in hatchling painted turtles after exposure to each of three temperatures (0 degree C, -4 degrees C, and -8 degrees C) for three time periods (5 days, 15 days, and 25 days) to determine the extent to which overwintering hatchlings might rely on anaerobic metabolism to regenerate ATP. Whole-body lactate increased with increasing duration of exposure and decreasing temperature, and the highest levels were associated with the group that experienced the highest mortality. These results indicate that animals may develop a considerable lactic acidosis during a winter in which temperatures fall below 0 degree C for weeks or months and that accumulation of lactate may contribute to mortality of overwintering animals.

Behavior and dam passage of juvenile Chinook salmon and juvenile steelhead at Detroit Reservoir and Dam, Oregon, March 2012-February 2013

USGS Publications Warehouse

Beeman, John W.; Hansel, Hal C.; Hansen, Amy C.; Evans, Scott D.; Haner, Philip V.; Hatton, Tyson W.; Kofoot, Eric E.; Sprando, Jamie M.; Smith, Collin D.

2014-01-01

The in-reservoir movements and dam passage of individual juvenile Chinook salmon (Oncorhynchus tshawytscha) and juvenile steelhead (Oncorhynchus mykiss) were studied at Detroit Reservoir and Dam, near Detroit, Oregon, during 2012 and 2013. The goal of the study was to provide data to inform decisions about future downstream passage alternatives and factors affecting downstream passage rates with the existing dam configuration. In 2012, 468 juvenile Chinook salmon and 200 juvenile steelhead were tagged and released during a 3-month period in the spring, and another 514 juvenile Chinook salmon were tagged and released during a 3-month period in the fall. The fish were surgically implanted with a small acoustic transmitter with an expected life of about 3 months and a passive integrated transponder tag with an indefinite life, and were released into the two main tributaries several kilometers upstream of the reservoir. Juvenile Chinook salmon migrated from the release sites to the reservoir in a greater proportion than juvenile steelhead, but once in the reservoir, juvenile steelhead migrated to the forebay faster and had a higher dam passage rate than juvenile Chinook salmon. The routes available for passing water and fish varied throughout the year, with low reservoir elevations in winter and high reservoir elevations in summer in accordance with the flood-control purpose of the dam. Most dam passage was through the spillway during the spring and summer, when the reservoir elevation was high and the spillway and powerhouse were the most common routes in operation, and via the powerhouse during the fall and winter period, when the reservoir elevation was low and the regulating outlet and powerhouse were the most common routes in operation. Few tagged fish passed when the powerhouse was the only route in operation. Dam passage rates during the spring and summer were greatest at night, increased with dam discharge, and were greater when water was passed freely over the spillway compared to when it was controlled by the spillway Tainter gates. Dam passage rates during the fall and winter, when the reservoir elevation usually was too low for spillway operation, were lower than during the spring and summer, negatively related to reservoir elevation, and positively related to dam discharge, though the latter relation diminished as reservoir elevation decreased. Fish locations near the dam from estimates of three-dimensional positions often were near the locations of dam discharge and fish depths were surface oriented relative to the depth of the forebay. Fish passage rates with the existing dam configuration were greatest when the spillway was in operation and were lowest when the powerhouse was the only route in operation; the latter result may be related to the relatively low magnitude or variability in discharge during that condition. The available data suggest that a properly designed surface outlet could be a viable passage route for juvenile Chinook salmon and juvenile steelhead at Detroit Dam. A second year of data collection based on a similar study design was complete at the time of this report.

[Thermal comfort and indoor air quality in some of the italian state police workplaces.

PubMed

Chirico, Francesco; Rulli, Giuseppina

2017-12-01

Little can be found in the literature about thermal comfort and indoor air quality (IAQ) in law enforcement workplaces. This study, based on environmental surveys carried out by the Centro Sanitario Polifunzionale of Milan (Italian State Police Health Service Department), aims to assess the thermal comfort and IAQ in some of the Italian State Police workplaces. Measurements were performed in some indoor workplaces such as offices, archives, laboratories and guard-houses in various regions (Lombardia, Emilia Romagna, Liguria, Veneto, Trentino Alto-Adige) of Northern Italy. The PMV/PPD model developed by Fangar for the evaluation of the thermal comfort was used. We measured both CO2 concentration and relative humidity indoor levels for the evaluation of IAQ. We used Chi square and t Student tests to study both prevalence of thermal discomfort and low IAQ, and their differences between summer and winter. For the purposes of the present study we carried out 488 measurements in 36 buildings (260 in winter and 228 in summer). Our results showed that thermal comfort was reached in 95% and 68% of environmental measurements (in winter and summer, respectively). In summer, we measured different types of thermal discomfort. As regard to IAQ, CO2 exceeded the threshold limit value (1000 ppm) in 39% (winter) and 9% (summer) of our measurements. Chi-square test showed a statistically significant difference between summer and winter for all outcomes considered. Indeed, thermal comfort was better in winter than summer (X2 = 61.0795), while IAQ was found to be better in the summer than winter considering both the CO2 1000 ppm and 1200 ppm threshold values (X2 = 56.9004 and X2 = 8.8845 respectively). Prevalence of low relative humidity in winter was higher than in summer (X2 = 124.7764). Even though this study did not report any situation of risk to Italian police officers health and safety, it has highlighted some potential issues in some of the examined workplaces, concerning thermal comfort in summer and IAQ in winter. Regarding the risk assessment process, simple and inexpensive preventive measures are already feasible in the 'observation phase' of the risk assessment, before execution of instrumental environmental survey. According to the technical standards and risk assessment models, this way might increase both comfort levels for workers employed in indoor environments and the effectiveness of the risk assessment process, through the optimization of available resources. Copyright© by Aracne Editrice, Roma, Italy.

Stable carbon and oxygen isotope ratios of winter flounder otoliths assess connectivity between juvenile and adult habitats

NASA Astrophysics Data System (ADS)

Pruell, Richard; Taplin, Bryan

2017-04-01

Winter flounder populations (Pseudopleuronectes americanus) have significantly declined in recent years along the Rhode Island, USA coastline. The reasons for this decline are not completely clear; however, habitat loss may be a factor. Therefore, knowledge of connectivity between juvenile nearshore habitats and the adult offshore populations may be important for improved management of this fishery. This study was undertaken to determine if stable carbon (δ13C) and oxygen (δ18O) isotope ratios in otoliths could be used to differentiate the locations that serve as important juvenile habitats for winter flounder. It is generally believed that winter flounder spawn during late winter in nearshore areas, and juvenile fish reside in shallow-water habitats along the coastline during their first summer. Once young-of-the-year flounder undergo metamorphosis and settle, they remain in close proximity to that site until fall. Adult fish move offshore during the late winter and spring, and then return to their natal estuaries during the fall and winter to spawn. Juvenile flounder were collected yearly over a three-year period from 18 juvenile habitats with a wide range of salinities. Several years later adult flounder of the same cohorts were obtained from similar inshore locations and also from the offshore fishery. Sagital otoliths were removed from the adult flounder and the core of the otolith representing the juvenile period was obtained using a Micromill drilling system. These juvenile otolith cores from adult fish and whole sagittal otoliths from juvenile flounder were analyzed for δ13C and δ18O using continuous-flow isotope ratio mass spectrometry. Results from these analyses show significant differences in δ13C and δ18O signatures among water bodies (bay, coastal ponds and an estuarine river). Preliminary analysis indicates that the isotope ratios of the juvenile cores from adult flounder and whole otoliths from juvenile fish collected at the same locations were similar. Isotope data for juvenile cores from adult flounder obtained from the offshore fishery indicate that many of these flounder spent their first year in high salinity areas and not in estuarine systems.

Organic iodine in Antarctic sea ice: A comparison between winter in the Weddell Sea and summer in the Amundsen Sea

NASA Astrophysics Data System (ADS)

Granfors, Anna; Ahnoff, Martin; Mills, Matthew M.; Abrahamsson, Katarina

2014-12-01

Recent studies have recognized sea ice as a source of reactive iodine to the Antarctic boundary layer. Volatile iodinated compounds (iodocarbons) are released from sea ice, and they have been suggested to contribute to the formation of iodine oxide (IO), which takes part in tropospheric ozone destruction in the polar spring. We measured iodocarbons (CH3I, CH2ClI, CH2BrI, and CH2I2) in sea ice, snow, brine, and air during two expeditions to Antarctica, OSO 10/11 to the Amundsen Sea during austral summer and ANT XXIX/6 to the Weddell Sea in austral winter. These are the first reported measurements of iodocarbons from the Antarctic winter. Iodocarbons were enriched in sea ice in relation to seawater in both summer and winter. During summer, the positive relationship to chlorophyll a biomass indicated a biological origin. We suggest that CH3I is formed biotically in sea ice during both summer and winter. For CH2ClI, CH2BrI, and CH2I2, an additional abiotic source at the snow/ice interface in winter is suggested. Elevated air concentrations of CH3I and CH2ClI during winter indicate that they are enriched in lower troposphere and may take part in the formation of IO at polar sunrise.

Changes in proximate composition and somatic energy content for Pacific sand lance (Ammodytes hexapterus) from Kachemak Bay, Alaska relative to maturity and season

USGS Publications Warehouse

Robards, Martin D.; Anthony, Jill A.; Rose, George A.; Piatt, John F.

1999-01-01

Mean dry-weight energy values of adult Pacific sand lance (Ammodytes hexapterus) peaked in spring and early summer (20.91 kJg−1 for males, 21.08 kJg−1 for females), then declined by about 25% during late summer and fall (15.91 kJg−1 for males, 15.74 kJg−1 for females). Late summer declines in energy density paralleled gonadal development. Gender differences in energy density (males

Seasonal changes in steroid hormone profiles, body weight, semen quality, and the reproductive tract in captive African wild dogs (Lycaon pictus) in South Africa.

PubMed

Newell-Fugate, Annie E; O Nöthling, Johan; J Bertschinger, Henk

2012-09-01

Characterization of reproductive seasonality in the African wild dog (Lycaon pictus) could assist reintroduction programs. Male wild dogs (n=14) were assessed quarterly (January, mid-summer; April, late summer; August, late winter; November, early summer) for serum testosterone, body weight, testicular and prostatic volume, preputial gland measurement, and ejaculate characteristics. Bi-monthly fecal samples were collected from male (n=11) and female (n=4) wild dogs for analysis of fecal androgens and progestagens. Fecal androgens were higher in early summer (246.4 ± 14.5 ng/g) than in early winter (218.6 ± 13.4 ng/g). Serum testosterone was higher in mid-summer (1.4 ± 0.3 ng/ml) than in late winter (0.7 ± 0.1 ng/ml). Number of spermatozoa per ejaculate was greatest in late summer (301.4 ± 39.3 × 10(6)). Other semen parameters peaked in mid-summer (pH: 7.4; progressive motility: 85.0 ± 0.1%; live spermatozoa: 81.0 ± 16%; normal morphology: 71.5 ± 8.2%). Total testicular and prostatic volume were greater during summer (testicular: 36.7 ± 4.2 cm(3); prostatic: 12.0 ± 1.9 cm(3)) than winter (testicular: 25.2 ± 1.9 cm(3); prostatic: 5.8 ± 0.8 cm(3)). Preputial pendulance also was greater in summer (7.1 ± 0.5 cm; n=9) than winter (5.9 ± 0.2 cm). Baseline fecal progestagen metabolites were 6.2 ± 2.5 μg/g and peak fecal progestagen metabolites were 14.7 ± 2.8 μg/g. Copulations resulting in pregnancies (n=2) occurred in late summer and gestation was 71 days. Female wild dogs were seasonally monoestrous with mating in summer and winter. In conclusion, wild dogs are reproductively seasonal with improvement in male reproductive variables during summer and a bi-phasic seasonal pattern to female receptivity. Copyright © 2012 Elsevier Inc. All rights reserved.

A realistic in vitro exposure revealed seasonal differences in (pro-)inflammatory effects from ambient air in Fribourg, Switzerland.

PubMed

Bisig, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

2018-01-01

Ambient air pollutant levels vary widely in space and time, therefore thorough local evaluation of possible effects is needed. In vitro approaches using lung cell cultures grown at the air-liquid interface and directly exposed to ambient air can offer a reliable addition to animal experimentations and epidemiological studies. To evaluate the adverse effects of ambient air in summer and winter a multi-cellular lung model (16HBE14o-, macrophages, and dendritic cells) was exposed in a mobile cell exposure system. Cells were exposed on up to three consecutive days each 12 h to ambient air from Fribourg, Switzerland, during summer and winter seasons. Higher particle number, particulate matter mass, and nitrogen oxide levels were observed in winter ambient air compared to summer. Good cell viability was seen in cells exposed to summer air and short-term winter air, but cells exposed three days to winter air were compromised. Exposure of summer ambient air revealed no significant upregulation of oxidative stress or pro-inflammatory genes. On the opposite, the winter ambient air exposure led to an increased oxidative stress after two exposure days, and an increase in three assessed pro-inflammatory genes already after 12 h of exposure. We found that even with a short exposure time of 12 h adverse effects in vitro were observed only during exposure to winter but not summer ambient air. With this work we have demonstrated that our simple, fast, and cost-effective approach can be used to assess (adverse) effects of ambient air.

Pulsed resources at tundra breeding sites affect winter irruptions at temperate latitudes of a top predator, the snowy owl.

PubMed

Robillard, A; Therrien, J F; Gauthier, G; Clark, K M; Bêty, J

2016-06-01

Irruptive migration is mostly observed in species specialized on pulsed resources and is thought to be a response to unpredictable changes in food supply. We assessed two alternative hypotheses to explain the periodic winter irruptions of snowy owls Bubo scandiacus every 3-5 years in temperate North America: (a) the lack-of-food hypothesis, which states that a crash in small mammal abundance on the Arctic breeding grounds forces owls to move out of the tundra massively to search for food in winter; (b) the breeding-success hypothesis, which states that high abundance of tundra small mammals during the summer allows for high production of young, thus increasing the pool of migrants moving south the following winter. We modeled winter irruptions of snowy owls in relation to summer food resources and geographic location. Winter abundance of owls was obtained from citizen-based surveys from 1994 to 2011 and summer abundance of small mammals was collected in summer at two distant sites in Canada: Bylot Island, NU (eastern High Arctic) and Daring Lake, NWT (central Low Arctic). Winter owl abundance was positively related to prey abundance during the previous summer at both sites and tended to decrease from western to eastern temperate North America. Irruptive migration of snowy owls was therefore best explained by the breeding success hypothesis and was apparently caused by large-scale summer variations in food. Our results, combined with previous findings, suggest that the main determinants of irruptive migration may be species specific even in a guild of apparently similar species.

Potential source identification for aerosol concentrations over a site in Northwestern India

NASA Astrophysics Data System (ADS)

Payra, Swagata; Kumar, Pramod; Verma, Sunita; Prakash, Divya; Soni, Manish

2016-03-01

The collocated measurements of aerosols size distribution (ASD) and aerosol optical thickness (AOT) are analyzed simultaneously using Grimm aerosol spectrometer and MICROTOP II Sunphotometer over Jaipur, capital of Rajasthan in India. The contrast temperature characteristics during winter and summer seasons of year 2011 are investigated in the present study. The total aerosol number concentration (TANC, 0.3-20 μm) during winter season was observed higher than in summer time and it was dominated by fine aerosol number concentration (FANC < 2 μm). Particles smaller than 0.8 μm (at aerodynamic size) constitute ~ 99% of all particles in winter and ~ 90% of particles in summer season. However, particles greater than 2 μm contribute ~ 3% and ~ 0.2% in summer and winter seasons respectively. The aerosols optical thickness shows nearly similar AOT values during summer and winter but corresponding low Angstrom Exponent (AE) values during summer than winter, respectively. In this work, Potential Source Contribution Function (PSCF) analysis is applied to identify locations of sources that influenced concentrations of aerosols over study area in two different seasons. PSCF analysis shows that the dust particles from Thar Desert contribute significantly to the coarse aerosol number concentration (CANC). Higher values of the PSCF in north from Jaipur showed the industrial areas in northern India to be the likely sources of fine particles. The variation in size distribution of aerosols during two seasons is clearly reflected in the log normal size distribution curves. The log normal size distribution curves reveals that the particle size less than 0.8 μm is the key contributor in winter for higher ANC.

Impact of recharge water temperature on bioclogging during managed aquifer recharge: a laboratory study

NASA Astrophysics Data System (ADS)

Xia, Lu; Gao, Zongjun; Zheng, Xilai; Wei, Jiuchuan

2018-04-01

To investigate the effect of recharge water temperature on bioclogging processes and mechanisms during seasonal managed aquifer recharge (MAR), two groups of laboratory percolation experiments were conducted: a winter test and a summer test. The temperatures were controlled at 5±2 and 15±3 °C, and the tests involved bacterial inoculums acquired from well water during March 2014 and August 2015, for the winter and summer tests, respectively. The results indicated that the sand columns clogged 10 times faster in the summer test due to a 10-fold larger bacterial growth rate. The maximum concentrations of total extracellular polymeric substances (EPS) in the winter test were approximately twice those in the summer test, primarily caused by a 200 μg/g sand increase of both loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS). In the first half of the experimental period, the accumulation of bacteria cells and EPS production induced rapid bioclogging in both the winter and summer tests. Afterward, increasing bacterial growth dominated the bioclogging in the summer test, while the accumulation of LB-EPS led to further bioclogging in the winter test. The biological analysis determined that the dominant bacteria in experiments for both seasons were different and the bacterial community diversity was 50% higher in the winter test than that for summer. The seasonal inoculums could lead to differences in the bacterial community structure and diversity, while recharge water temperature was considered to be a major factor influencing the bacterial growth rate and metabolism behavior during the seasonal bioclogging process.

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

PubMed

Sen, Supatra; Mukherji, S

2009-07-01

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

High Resolution Time Series Cave Ventilation Processes and the Effects on Cave Air Chemistry and Drip Waters: Speleoclimatology and Proxy Calibration

NASA Astrophysics Data System (ADS)

Kowalczk, A. J.; Froelich, P. N.; Gaffka, C.; Tremaine, D.

2008-12-01

Continuous high resolution (sub-hourly), long-term (Nov 2007-present) monitoring of cave air chemistry (Temperature, Relative Humidity, Barometric Pressure, Radon-222, CO2, Air flow, Wind speed and direction) in a shallow subtropical cave (Hollow Ridge) in N Florida reveals two major ventilation mechanisms: 1) ventilation driven by winds across the cave entrances, and 2) ventilation driven by density differences between atmospheric and cave air. The degree and type of ventilation strongly influence the 222Rn and CO2 of cave air, which in turn affects the timing and extent of calcite deposition in speleothems. The degree of ventilation is estimated using a cave air CO2-δ13CO2 Keeling Plot, or a simple radon deficiency model. Results show cave air has an atmospheric component ranging from 10-90%. During fall and winter, average CO2 (700 ppmv) and 222Rn (50-100 dpm/L) are lower than in spring and summer (CO2 = 1200 ppmv; 222Rn = 1000 dpm/L) due to increased winter ventilation. Decreased ventilation during the summer allows CO2 and 222Rn levels to rise. Winter daily ventilation is primarily a function of density gradients between cave air and atmospheric air, while summer daily ventilation is primarily a function of late morning NW-NE winds above the cave. Stable isotope analyses of drip water (fracture drip and pore flow drip) and aquifer water from Hollow Ridge agree with previous isotope studies of drip water at Florida Caverns State Park, 2 km to the NE. During summer, isotopic composition of pore flow drip water (δ18O -3.8 to -4.0 per mil; δD -17.3 to -20.2 per mil VSMOW) and aquifer water (δ18O -4.0 per mil; δD -18.0 to -21.1 per mil) are similar to average annual weighted isotopic composition of precipitation (δ18O -3.6 per mil) while fracture drip waters (δ18O -3 to -3.4 per mil; δD -11.9 to -14.3 per mil) likely reflect the isotopic composition of individual precipitation events. Pore flow drip waters δ18O are weakly correlated with drip rates (enriched δ18O during periods of higher drip rates) but show no correlation to precipitation amount. Knowledge of the type of drip flow is important when considering stalagmites for paleoclimate studies. A significant decrease in drip rate was observed from June (1034 drips/hour) through August 2008 (34 drips/hour). Higher water demands during summer months with increased evapotranspiration may be responsible for this decrease. A semi-diurnal drip rate cycle, negatively correlated with barometric pressure, is also observed throughout the period. This strong negative correlation is hypothesized to be controlled by atmospheric tidal oscillations. Observations into the fall and winter seasons should reveal seasonality, if any, and if there is an evapotranspiration effect present in the water cycle. High resolution studies of cave air chemistry and ventilation processes will enhance knowledge of the timing, extent, and isotopic and chemical composition of calcite deposition. When combined with drip water and precipitation isotope analyses, these studies will improve the understanding and interpretation of high- resolution (sub-annual) speleothem paleoclimate records.

Acoustic Imaging Evaluation of Juvenile Salmonid Behavior in the Immediate Forebay of the Water Temperature Control Tower at Cougar Dam, 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Fenton; Johnson, Gary E.; Royer, Ida M.

This report presents the results of an evaluation of juvenile Chinook salmon (Oncorhynchus tshawytscha) behavior at Cougar Dam on the south fork of the McKenzie River in Oregon in 2010. The study was conducted by the Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers (USACE). The overall goal of the study was to characterize juvenile salmonid behavior and movement patterns in the immediate forebay of the Water Temperature Control (WTC) tower of the dam for USACE and fisheries resource managers use in making decisions about bioengineering designs for long-term structures and/or operations to facilitate safe downstream passagemore » for juvenile salmonids. We collected acoustic imaging (Dual-Frequency Identification Sonar; DIDSON) data from March 1, 2010, through January 31, 2011. Juvenile salmonids (hereafter, called 'fish') were present in the immediate forebay of the WTC tower throughout the study. Fish abundance index was low in early spring (<200 fish per sample-day), increased in late April, and peaked on May 19 (6,039 fish). A second peak was observed on June 6 (2904 fish). Fish abundance index decreased in early June and remained low in the summer months (<100 fish per sample-day). During the fall and winter, fish numbers varied with a peak on November 10 (1881 fish) and a minimum on December 7 (12 fish). A second, smaller, peak occurred on December 22 (607 fish). A univariate statistical analysis indicated fish abundance index (log10-transformed) was significantly (P<0.05) positively correlated with forebay elevation, velocity over the WTC tower intake gate weirs, and river flows into the reservoir. A subsequent multiple regression analysis resulted in a model (R2=0.70) predicting fish abundance (log-transformed index values) using two independent variables of mean forebay elevation and the log10 of the forebay elevation range. From the approximate fish length measurements made using the DIDSON imaging software, the average fish length during early spring 2010 was 214 {+-} 86 mm (standard deviation). From May through early November, the average fish length remained relatively consistent (132 {+-} 54 mm), after which average lengths increased to 295 {+-} 148 mm for mid-November though early December. From mid-December through January the average fish length decreased to 151 {+-} 76 mm. Milling in front of the WTC tower was the most common fish behavior observed throughout the study period. Traversing along the front of the tower, east-to-west and west-to-east, was the next common behavior. The percentage of fish events showing movement from the forebay to the tower or from the tower to the forebay was generally low throughout the spring, summer, and early fall (0 to 30% for both directions combined, March through early November). From mid-November 2010 through the end of the study (January 31, 2011), the combined percentages of fish moving into and out of the tower were higher (25 to 70%) than during previous months of the study. Schooling behavior was most distinct in the spring. Schooling events were present in 30 to 96% of the fish events during that period, with a peak on May 19. Schooling events were also present in the summer, but at lower numbers. With the exception of some schooling in mid-December, few to no schooling events were observed in the fall and winter months. Diel distributions for schooling fish during spring and fall months indicate schooling was concentrated during daylight hours and no schooling was observed at night. However, in December, schooling occurred at night, after midnight, and during daylight hours. Predator activity, most likely bull trout or rainbow trout according to a USACE biologist, was observed during late spring, when fish abundance index and schooling were highest for the year, and again in the fall months when fish events increased from a summer low. No predator activity was observed in the summer, and little activity occurred during the winter months.« less

Seasonal distribution of bird populations at the Patuxent Research Refuge

USGS Publications Warehouse

Stewart, R.E.; Cope, J.B.; Robbins, C.S.; Brainerd, J.W.

2000-01-01

A detailed study of seasonal changes in bird populationswas made at the Patuxent Research Refuge, located between Bowie and Laurel, Maryland during the years 1936-1949. The history of the Refuge is reviewed and its physical and biological characteristlcs summarized.. The methods of study used during the investigation mcluded: periodic censuses of a representative 304-acre study area over a two-year period; a census of the breeding population of the entire. Refuge during one year; detailed population studies of representative habitats during the breeding season; censuses of the wintering population of. the entire Refuge during two years; general surveys of wintering populations for seven years; and general observations of seasonal changes in bird populatlons over a fourteen-year period, including data from an extensive banding program and from many special types of censuses. The phenology of the Refuge is described in conslderable detail throughout the year, with special attention given to major fluctuatIons in bIrd populations as correlated with climatic changes and with seasonal aspectlon. of the vegetation. The component specIes of birds m the more important migration waves are listed. Figures approximating the Refuge breeding and wmtering populations are given, while indices representing the relative abundance of bird populations, based on figures from the two-year seasonal populatlon study, were obtained for the entire year. The greatest variety of species as well as the greatest number of individuals occurred on the Refuge during the migration .periods in spring and fall, the variety of species being slightly higher in spring than in fa!l, while the population of individuals was considerably higher in fall. Wmtering and breeding populations were low and relatively stable compared to the populations at other seasons.The ecological affinities of the bird populations differed greatly from one season to another. Species characteristic of edge habitats were much more numerous in winter, while forest species were predominant in summer. Insectivorous species comprised a large proportion (40 to 60 percent) of the total population during the warmer months, but were of minor importance in winter. The greatest number of species of birds on the Refuge occurred during the population peaks of insectivorous species, while the largest number of individuals was found during the population peaks of omnivorous and herbivorous species. The population peaks of insectivorous species were found to occur much later in spring and considerably earlier in fall than the. corresponding peaks of omnivorous and herbivorous species. The Fringillidae contributed the greatest number of individuals in winter, while the Parulidae was the most important family (numerically) in summer. Water birds and marsh birds were relatively unimportant throughout the year, due to the scarcity of suitable habitats. Permanent resident species were found to vary from about one-fifth to slightly less than one-half of the total population throughout the year, although many individuals of these species were either transients or part-time residents. Summer residents and winter residents were more abundant than permanent residents during their respective periods of occurrence. During the greater part of the migration period, transient species were found to comprise only 10 to 20 percent of the total population. transient individuals of all species would account for a much larger proportion of the population at this time. After comparing the results of these investigations with similar studies in other areas, it is believed that the seasonal population changes on the Patuxent Research Refuge are fairly representative of those occurring throughout the Middle Atlantic and East-central States. Yearly variations in seasonal population changes are described and the causative factors indicated, when known. Of these, food supply and weather conditions were generally the m

Seasonal and among-site variation in the occurrence and abundance of fleas on California ground squirrels (Otospermophilus beecheyi).

PubMed

Hubbart, Jason A; Jachowski, David S; Eads, David A

2011-06-01

An improved understanding of the ecology of fleas on California ground squirrels, Otospermophilus beecheyi, is warranted given the role of fleas in the transmission, and perhaps persistence, of the plague-causing bacterium Yersinia pestis. We sampled O. beecheyi on a seasonal basis from three study sites, each representing a different land use type (preserve, pasture, and agriculture) in the San Joaquin Valley, CA. Overall, the abundance of fleas on squirrels was greatest in spring at the preserve site, in summer at the agriculture and pasture sites, and in winter at the pasture site. Hoplopsyllus anomalus, the species most frequently found on squirrels, was most abundant in spring at the preserve site and in summer at the agriculture and pasture sites. Oropsylla montana was most abundant in winter at the pasture site and on adult squirrels. Echidnophaga gallinacea was most abundant in fall on juvenile squirrels at the preserve site. All three flea species we encountered are known to be potential vectors of Y. pestis. Future efforts to predict flea species occurrence and abundance (and plague risk) at sites of concern should consider seasonal microclimatic conditions and the potential influence of human land use practices. © 2011 The Society for Vector Ecology.

Evidence for insolation and Pacific forcing of late glacial through Holocene climate in the Central Mojave Desert (Silver Lake, CA)

NASA Astrophysics Data System (ADS)

Kirby, Matthew E.; Knell, Edward J.; Anderson, William T.; Lachniet, Matthew S.; Palermo, Jennifer; Eeg, Holly; Lucero, Ricardo; Murrieta, Rosa; Arevalo, Andrea; Silveira, Emily; Hiner, Christine A.

2015-09-01

Silver Lake is the modern terminal playa of the Mojave River in southern California (USA). As a result, it is well located to record both influences from the winter precipitation dominated San Bernardino Mountains - the source of the Mojave River - and from the late summer to early fall North American monsoon at Silver Lake. Here, we present various physical, chemical and biological data from a new radiocarbon-dated, 8.2 m sediment core taken from Silver Lake that spans modern through 14.8 cal ka BP. Texturally, the core varies between sandy clay, clayey sand, and sand-silt-clay, often with abrupt sedimentological transitions. These grain-size changes are used to divide the core into six lake status intervals over the past 14.8 cal ka BP. Notable intervals include a dry Younger Dryas chronozone, a wet early Holocene terminating 7.8 - 7.4 cal ka BP, a distinct mid-Holocene arid interval, and a late Holocene return to ephemeral lake conditions. A comparison to potential climatic forcings implicates a combination of changing summer - winter insolation and tropical and N Pacific sea-surface temperature dynamics as the primary drivers of Holocene climate in the central Mojave Desert.

Strong Seasonality of Marine Microbial Eukaryotes in a High-Arctic Fjord (Isfjorden, in West Spitsbergen, Norway)

PubMed Central

Vader, Anna; Stübner, Eike I.; Reigstad, Marit

2016-01-01

The Adventfjorden time series station (IsA) in Isfjorden, West Spitsbergen, Norway, was sampled frequently from December 2011 to December 2012. The community composition of microbial eukaryotes (size, 0.45 to 10 μm) from a depth of 25 m was determined using 454 sequencing of the 18S V4 region amplified from both DNA and RNA. The compositional changes throughout the year were assessed in relation to in situ fjord environmental conditions. Size fractionation analyses of chlorophyll a showed that the photosynthetic biomass was dominated by small cells (<10 μm) most of the year but that larger cells dominated during the spring and summer. The winter and early-spring communities were more diverse than the spring and summer/autumn communities. Dinophyceae were predominant throughout the year. The Arctic Micromonas ecotype was abundant mostly in the early-bloom and fall periods, whereas heterotrophs, such as marine stramenopiles (MASTs), Picozoa, and the parasitoid marine alveolates (MALVs), displayed higher relative abundance in the winter than in other seasons. Our results emphasize the extreme seasonality of Arctic microbial eukaryotic communities driven by the light regime and nutrient availability but point to the necessity of a thorough knowledge of hydrography for full understanding of their succession and variability. PMID:26746718

Arsenic in freshwater fish in the Chihuahua County water reservoirs (Mexico).

PubMed

Nevárez, Myrna; Moreno, Myriam Verónica; Sosa, Manuel; Bundschuh, Jochen

2011-01-01

Water reservoirs in Chihuahua County, Mexico, are affected by some punctual and non-punctual geogenic and anthropogenic pollution sources; fish are located at the top of the food chain and are good indicators for the ecosystems pollution. The study goal was to: (i) determine arsenic concentration in fish collected from the Chuviscar, Chihuahua, San Marcos and El Rejon water reservoirs; (ii) to assess if the fishes are suitable for human consumption and (iii) link the arsenic contents in fish with those in sediment and water reported in studies made the same year for these water reservoirs. Sampling was done in summer, fall and winter. The highest arsenic concentration in the species varied through the sampling periods: Channel catfish (Ictalurus punctatus) with 0.22 ± 0.15 mg/kg dw in winter and Green sunfish (Lepomis cyanellus) with 2.00 ± 0.15 mg/kg dw in summer in El Rejon water reservoir. A positive correlation of arsenic contents was found through all sampling seasons in fish samples and the samples of sediment and water. The contribution of the weekly intake of inorganic arsenic, based on the consumption of 0.245 kg fish muscles/body weight/week was found lower than the acceptable weekly intake of 0.015 mg/kg/body weight for inorganic arsenic suggested by FAO/WHO.

Comparison of the seasonal variability in abundance of the copepod Pseudocalanus newmani in Lagoon Notoro-ko and a coastal area of the southwestern Okhotsk Sea

NASA Astrophysics Data System (ADS)

Kitamura, Mitsuaki; Nakagawa, Yoshizumi; Nishino, Yasuto; Segawa, Susumu; Shiomoto, Akihiro

2018-03-01

Replacement of the warm water of the Soya Warm Current (SWC) and the cold water of the East Sakhalin Current (ESC) occurs seasonally along the coast of the southwestern Okhotsk Sea, and sea ice covers the surface during winter. Pseudocalanus newmani is one of the dominant copepods in coastal waters of the northern hemisphere. To better understand the population dynamics of the copepod P. newmani in coastal areas of the southwestern Okhotsk Sea, this study compared the seasonal variation in P. newmani abundance in Lagoon Notoro-ko and a coastal area of the Okhotsk Sea with regard to developmental stage. We sampled P. newmani in the lagoon, including during the ice cover season, and the coastal waters. Pseudocalanus newmani was abundant at both sites in spring. During summer-fall, adults disappeared from the populations at both sites, whereas the early developmental stages were abundant and dominated the population. Total length of adult females decreased toward summer at both sites. Pseudocalanus newmani abundance in the lagoon increased in early winter, and larger females were found in the populations at both sites. These phenomena at both sites corresponded with seasonal variation in water temperature caused by seasonal water-mass replacement and sea ice.

Paleosol stable isotope evidence for early hominid occupation of East Asian temperate environments

USGS Publications Warehouse

Wang, Hongfang; Ambrose, S.H.; Liu, Chen; Follmer, L.R.

1997-01-01

Hominids left Africa and occupied mainland Asia by 1.8 myr ago. About 1.15 myr ago Homo erectus and an associated Stegodon-Ailuropoda fauna migrated from subtropical China across the Qinling Mountains into the temperate Loess Plateau. This migration may be an evolutionary milestone in human adaptability because it may represent the first occupation of a nontropical environment. Loess-paleosol stable isotope ratios from the last interglacial-glacial cycle provide comparative data for reconstructing the hominid paleoenvironments. The climate during Gongwangling hominid occupation about 1.15 myr ago was influenced by both Siberian-Mongolian winter and Indian summer monsoon systems characterized as a cold/cool, dry winter and warm/mild, semihumid summer and fall. The Gongwangling hominids preyed mainly on warm-climate-adapted animals such as Stegodon-Ailuropoda fauna, suggesting a warm season occupation. The stable isotope ratios also indicate that the Chenjiawo hominids occupied an environment similar to that of the Gongwangling about 650,000 yr ago. The associated fauna, with a mixture of forest and steppe, warm-and cold/cool-climate-adapted animal assemblage's, suggests a permanent occupation by this time. Thus, the reliable earliest and permanent occupation of temperate environments may have occurred 150,000 yr earlier in eastern Asia rather than in Europe. ?? 1997 University of Washington.

Distribution of seabirds in the northern Gulf of Mexico in relation to mesoscale features: Initial observations

USGS Publications Warehouse

Ribic, C.A.; Davis, R.; Hess, N.; Peake, D.

1997-01-01

The presence of seabirds was related to offshore surface eddies and the freshwater plume of the Mississippi River in the northern Gulf of Mexico during autumn, winter, spring, and summer 1992-1993. Skuas (Stercorarius spp.) were the most common bird seen in autumn, whereas skuas and gulls (Larus spp.) were the most common in winter. Few birds were seen in the spring, and terns (Sterna spp.) were the most common birds seen in late summer. During summer, terns were associated with the freshwater plume of the Mississippi River. In the winter, herring (Larus argentatus) and laughing gulls (L. artricilla) were associated with areas with steep thermoclines, while pomarine skuas (Stercorarius pomarinus) were found in areas of low productivity. Herring and laughing gulls in the winter, all birds in the spring, and terns in the summer were more common outside eddies. Only pomarine skuas in the winter were seen more commonly inside warm-core eddies.

Winter movements of adult northern goshawks that nested in southcentral Wyoming

Treesearch

John R. Squires; Leonard F. Ruggiero

1995-01-01

Winter movements of four adult northern goshawks (Accipiter gentilis) that nest in southcentral Wyoming were monitored during the winter of 1992-93. Goshawks initiated fall migrations in early fall (primarily mid-September) while weather conditions are moderate. Female 1 migrated 185 km south of her nest. She wintered in a mountainous area in Colorado at a higher...

[Comparison of air/soil mercury exchange between warm and cold season in Hongfeng Reservoir region].

PubMed

Wang, Shao-feng; Feng, Xin-bin; Qiu, Guang-le; Fu, Xue-wu

2004-01-01

In July 2002 and March 2003, the mercury exchange flux between soil and air was measured using dynamic flux chamber method in Hongfeng Reservoir region. Mercury exchange flux is (27.4 +/- 40.1) ng x (m2 x h)(-1) (n = 255) and (5.6 +/- 19.4) ng x (m2 x h)(-1) (n = 192) in summer and winter respectively. The correlation coefficient between mercury flux and solar radiation, air temperature, soil temperature is 0.74, 0.83 and 0.80 in summer, and 0.88, 0.56 and 0.59 in winter. From the data, it was found that the mercury emission is stronger in summer than that in winter, and compared to winter, mercury exchange between soil and air depends more on meteorological conditions in summer.

Arctic cognition: a study of cognitive performance in summer and winter at 69 degrees N

NASA Technical Reports Server (NTRS)

Brennen, T.; Martinussen, M.; Hansen, B. O.; Hjemdal, O.

1999-01-01

Evidence has accumulated over the past 15 years that affect in humans is cyclical. In winter there is a tendency to depression, with remission in summer, and this effect is stronger at higher latitudes. In order to determine whether human cognition is similarly rhythmical, this study investigated the cognitive processes of 100 participants living at 69 degrees N. Participants were tested in summer and winter on a range of cognitive tasks, including verbal memory, attention and simple reaction time tasks. The seasonally counterbalanced design and the very northerly latitude of this study provide optimal conditions for detecting impaired cognitive performance in winter, and the conclusion is negative: of five tasks with seasonal effects, four had disadvantages in summer. Like the menstrual cycle, the circannual cycle appears to influence mood but not cognition.

Impact of the urban heat island on residents’ energy consumption: a case study of Qingdao

NASA Astrophysics Data System (ADS)

Ding, Feng; Pang, Huaji; Guo, Wenhui

2018-02-01

This paper examines impact of urban heat island on residents’ energy consumption through comparative analyses of monthly air temperature data observed in Qingdao, Laoshan and Huangdao weather stations. The results show effect of urban heat island is close related with urbanization speed. Recently, effects of urban heat island of Laoshan and Huangdao exceed that of Qingdao, consistent with rapid urbanization in Laoshan and Huangdao. Enhanced effect of urban heat island induces surface air temperature to rise up, further increase electricity energy consumption for air conditioning use in summer and reduce coal consumption for residents heating in winter. Comparing change of residents’ energy consumption in summer and winter, increments in summer are less than reduction in winter. This implicates effect of urban heat island is more obvious in winter than in summer.

Plasma biochemical reference values in clinically healthy captive bearded dragons (Pogona vitticeps) and the effects of sex and season.

PubMed

Tamukai, Kenichi; Takami, Yoshinori; Akabane, Yoshihito; Kanazawa, Yuko; Une, Yumi

2011-09-01

Bearded dragons are one of the most popular pet lizard species, and biochemical reference values are useful for health management of these reptiles. The objectives of this study were to measure plasma biochemical values in healthy captive bearded dragons, determine reference values, and evaluate the effects of sex and season on the results. Blood samples were collected from 100 captive healthy bearded dragons in Tokyo during the summer and winter. Plasma biochemical measurements were performed using a dry-slide automated biochemical analyzer. The data were then compared based on sex and season using 2-way ANOVA. Globulin, cholesterol, and calcium concentrations of females were higher in both summer and winter compared with the values obtained for males. Both males and females had higher uric acid concentrations in winter than in summer. When compared with males, females had a higher chloride concentration in summer and a higher total protein concentration and aspartate aminotransferase activity in winter. Potassium concentration in males was lower in winter than in summer, whereas in females cholesterol concentration was lower in winter than in summer. Biochemical values that differed based on sex and season in bearded dragons were similar to those in other lizards. These differences reflect physiologic differences in reproductive status in females and seasonal changes in temperature and hydration status. Plasma biochemical values established for bearded dragons in this study will be useful in the diagnostic assessment of captive animals. ©2011 American Society for Veterinary Clinical Pathology.

Five Years of Monitoring Mars' Daytime Surface Temperatures (Animation)

NASA Technical Reports Server (NTRS)

2005-01-01

[figure removed for brevity, see original site] Animation

This movie shows the daytime temperature of the surface of Mars as measured by the Thermal Emission Spectrometer instrument on NASA's Mars Global Surveyor orbiter. These temperatures clearly show the growth and retreat of the martian northern and southern polar ice caps. The caps grow in winter and are composed of carbon dioxide ice with temperatures as low as minus 125 degrees Celsius (minus 195 degrees Fahrenheit). In the summer the caps retreat to relatively small areas around the poles. The movie also demonstrates the large difference in temperatures between the northern hemisphere's summer (beginning when solar longitude, or Ls, is 90 degrees) and the southern hemisphere's summer (beginning when Ls is 270 degrees). This difference is because the orbit of Mars around the Sun is more elliptical than Earth's orbit. As on Earth, a hemisphere's summer is when that hemisphere is tilted toward the Sun, but on Mars, the planet's distance from the Sun varies much more than on Earth. Mars is closest to the Sun, and therefore warmest, during the southern summer season. In northern summer, when Mars' northern hemisphere is tilted toward the Sun, the planet is farther from the Sun.

Seasons on Mars are determined by the position of Mars in its orbit around the Sun. The position is measured in degrees of solar longitude (Ls) around the orbit, beginning at 0 degrees Ls at the northern spring equinox, progressing to 90 degrees Ls at the start of northern summer, 180 degrees Ls at the fall equinox, 270 degrees Ls at the start of northern winter, and finally back to 360 degrees, or 0 degrees, Ls at the spring equinox.

The Thermal Emission Spectrometer is operated by a team led at Arizona State University, Tempe. Mars Global Surveyor left Earth on Nov. 7, 1996, and began orbiting Mars on Sept. 12, 1997. JPL, a division of the California Institute of Technology, Pasadena, manages Mars Global Surveyor for NASA's Science Mission Directorate, Washington.

Intercontinental Spread of Asian-Origin H5N8 to North America through Beringia by Migratory Birds.

PubMed

Lee, Dong-Hun; Torchetti, Mia Kim; Winker, Kevin; Ip, Hon S; Song, Chang-Seon; Swayne, David E

2015-06-01

Phylogenetic network analysis and understanding of waterfowl migration patterns suggest that the Eurasian H5N8 clade 2.3.4.4 avian influenza virus emerged in late 2013 in China, spread in early 2014 to South Korea and Japan, and reached Siberia and Beringia by summer 2014 via migratory birds. Three genetically distinct subgroups emerged and subsequently spread along different flyways during fall 2014 into Europe, North America, and East Asia, respectively. All three subgroups reappeared in Japan, a wintering site for waterfowl from Eurasia and parts of North America. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Applying Poultry Litter in the Fall to Fertilize Corn May not be Advisable Under Warm Climate

USDA-ARS?s Scientific Manuscript database

Row crop farmers prefer to apply poultry litter in the fall or winter but whether this practice is safe environmentally and effective for production in regions with warm fall and winter months is not well researched and documented. Research in Mississippi tested the effectiveness of fall- versus spr...

34 CFR 690.63 - Calculation of a Federal Pell Grant for a payment period.

Code of Federal Regulations, 2010 CFR

2010-07-01

... fall through the following spring, or three quarters in the fall, winter, and spring, none of which... program using an academic calendar that includes two semesters or trimesters in the fall through the following spring, or three quarters in the fall, winter, and spring; and (B) Does not provide at least 30...

Effects of living at two ambient temperatures on 24-h blood pressure and neuroendocrine function among obese and non-obese humans: a pilot study

NASA Astrophysics Data System (ADS)

Kanikowska, Dominika; Sato, Maki; Iwase, Satoshi; Shimizu, Yuuki; Nishimura, Naoki; Inukai, Yoko; Sugenoya, Junichi

2013-05-01

The effects of environmental temperature on blood pressure and hormones in obese subjects in Japan were compared in two seasons: summer vs winter. Five obese (BMI, 32 ± 5 kg/m2) and five non-obese (BMI, 23 ±3 kg/m2) men participated in this experiment at latitude 35°10' N and longitude 136°57.9' E. The average environmental temperature was 29 ± 1 °C in summer and 3 ± 1 °C in winter. Blood samples were analyzed for leptin, ghrelin, catecholamines, thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), total cholesterol, triglycerides, insulin and glucose. Blood pressure was measured over the course of 24 h in summer and winter. A Japanese version of the Profile of Mood States (POMS) questionnaire was also administered each season. Systolic and diastolic blood pressures in obese men were significantly higher in winter (lower environmental temperatures) than in summer (higher environmental temperatures). Noradrenaline and dopamine concentrations were also significantly higher at lower environmental temperatures in obese subjects, but ghrelin, TSH, fT3, fT4, insulin and glucose were not significantly different in summer and winter between obese and non-obese subjects. Leptin, total cholesterol and triglyceride concentrations were significantly higher in winter in obese than non-obese men. Results from the POMS questionnaire showed a significant rise in Confusion at lower environmental temperatures (winter) in obese subjects. In this pilot study, increased blood pressure may have been due to increased secretion of noradrenaline in obese men in winter, and the results suggest that blood pressure control in obese men is particularly important in winter.

Comparisons of observed seasonal climate features with a winter and summer numerical simulation produced with the GLAS general circulation model

NASA Technical Reports Server (NTRS)

Halem, M.; Shukla, J.; Mintz, Y.; Wu, M. L.; Godbole, R.; Herman, G.; Sud, Y.

1979-01-01

Results are presented from numerical simulations performed with the general circulation model (GCM) for winter and summer. The monthly mean simulated fields for each integration are compared with observed geographical distributions and zonal averages. In general, the simulated sea level pressure and upper level geopotential height field agree well with the observations. Well simulated features are the winter Aleutian and Icelandic lows, the summer southwestern U.S. low, the summer and winter oceanic subtropical highs in both hemispheres, and the summer upper level Tibetan high and Atlantic ridge. The surface and upper air wind fields in the low latitudes are in good agreement with the observations. The geographical distirbutions of the Earth-atmosphere radiation balance and of the precipitation rates over the oceans are well simulated, but not all of the intensities of these features are correct. Other comparisons are shown for precipitation along the ITCZ, rediation balance, zonally averaged temperatures and zonal winds, and poleward transports of momentum and sensible heat.

Growth, condition, diet, and consumption rates of northern pike in three Arizona reservoirs

USGS Publications Warehouse

Flinders, J.M.; Bonar, Scott A.

2008-01-01

Northern pike (Esox lucius L.) introductions are controversial in the western United States due to suspected impacts they might have on established sport fisheries and potential illegal introductions. Tbree Arizona reservoirs, Parker Canyon Lake, Upper Lake Mary and Long Lake were sampled to examine the diet, consumption dynamics, and growth of northern pike. Northern pike diets varied by season and reservoir. In Parker Canyon Lake, diets were dominated by rainbow trout in winter and spring and bluegill and green sunfish in the fall. In Long Lake the northern pike ate crayfish in spring and early summer and switched to young of the year common carp in summer and fall. Black crappie, golden shiners, and crayfish were the major prey in Upper Lake Mary during spring, but they switched to stocked rainbow trout in the fall. Northern pike growth was in the high range of growth reported throughout the United States. Estimated northern pike specific consumption rate (scr) of rainbow trout (g/g/d ?? 10-6) was greatest in Upper Lake Mary (scr = 329.1 ?? 23.7 g/g/d ?? 10-6) where stocked fingerling (280 mm TL) rainbow trout stocked in Long Lake (scr = 1.4 ?? 0.1 g/g/d ?? 10-6) and Parker Canyon Lake (scr = 287.2 ?? 15.1 g/g/d ?? 10-6) where catchable-sized rainbow trout were stocked. Managers should consider the cost-benefits of stocking fish >200 mm TL in lakes containing northern pike. ?? Copyright by the North American Lake Management Society 2008.

Survey of conditions for artificial aurora experiments by the second electron gyro-harmonic at EISCAT Tromsø using dynasonde data

NASA Astrophysics Data System (ADS)

Tsuda, T. T.; Rietveld, M. T.; Kosch, M. J.; Oyama, S.; Ogawa, Y.; Hosokawa, K.; Nozawa, S.; Kawabata, T.; Mizuno, A.

2018-06-01

We report a brief survey of matching conditions for artificial aurora optical experiments utilizing the second electron gyro-harmonic (2.7-MHz frequency) in F region heating with O-mode at the EISCAT Tromsø site using dynasonde data from 2000 to 2017. Our survey indicates the following: The possible conditions for successful artificial aurora experiments are concentrated on twilight hours in both evening and morning, compared with late night hours; the possible conditions appear in fall, winter, and spring, while there is no chance in summer, and the month-to-month variation among fall, winter, and spring is not so clear; the year-to-year variation is well correlated with the solar activity. These characteristics in the case of 2.7-MHz frequency are basically similar to those previously reported in the case of 4-MHz frequency. However, the number of days meeting the possible condition in the case of 2.7-MHz frequency is obviously large, compared with that in the case of 4-MHz frequency. In particular, unlike the 4-MHz frequency operation, the 2.7-MHz frequency operation can provide many chances for successful artificial aurora experiments even during the solar minimum.

Utilizing ERTS-1 imagery for tectonic analysis through study of the Bighorn Mountains region

NASA Technical Reports Server (NTRS)

Hoppin, R. A. (Principal Investigator)

1973-01-01

The author has identified the following significant results. Comparisons of imagery of three seasons, late summer-fall, winter, and spring indicate that for this region fall imagery is the best for overall geologic analysis. Winter scenes with light to moderate snow cover provide excellent topographic detail owing to snow enhancement, lower sun angle, and clarity of the atmosphere. Spring imagery has considerable reduction of tonal contrast owing to the low reflecting heavy green grass cover which subdues lithologic effects; heavy snow cover in the uplands masks topography. Mapping of geologic formations is impractical in most cases. Separation into tonal units can provide some general clues on structure. A given tonal unit can include parts of several geologic formations and different stratigraphic units can have the same tonal signature. Drainage patterns and anomalies provide the most consistent clues for detecting folds, monoclines, and homoclines. Vegetation only locally reflects lithology and structure. False color infrared 9 x 9 transparencies are the most valuable single imagery. Where these can be supplemented by U-2 color infrared for more detailed work, a tremendous amount of information is available. Adequately field checking such a large area just in one scene is the major logistic problem even in a fairly well known region.

Epizootiologic studies of avian vacuolar myelinopathy in waterbirds

USGS Publications Warehouse

Rocke, Tonie E.; Thomas, N.J.; Augspurger, T.; Miller, Kimberli J.

2002-01-01

Epizootic avian vacuolar myelinopathy (AVM) was first recognized as a neurologic disease in bald eagles (Haliaeetus leucocephalus) and American coots (Fulica americana) in Arkansas, USA in 1994 and 1996, respectively, but attempts to identify the etiology of the disease have been unsuccessful to date. Between 1998 and 2001, wing clipped sentinel birds (wild American coots and game farm mallards [Anas platyrhynchos]) were released at Lake Surf, North Carolina, a lake with recurrent outbreaks of AVM, in order to gain a better understanding of the epizootiology of the disease. As early as 5-7 days post-release, sentinel coots and mallards showed neurologic signs of disease and were confirmed with AVM upon histologic examination of their brains. Serial releases of sentinel mallards during the summer, fall, and winter of 2000-01 demonstrated that exposure to the causative agent at a threshold sufficient to manifest disease was seasonal and occurred over about a 2 mo period, during November and December. Our findings that disease onset can be very rapid (5-7 days) and that exposure to the causative agent of AVM is site-specific, seasonal (late fall to early winter), and occurs over a relatively short duration (several months) supports the hypothesis that the disease is caused by a chemical substance, most likely of natural origin.

Estimating population parameters for northern and southern breeding populations of Canada geese

USGS Publications Warehouse

Hestbeck, J.B.; Rusch, Donald H.; Samuel, Michael D.; Humburg, Dale D.; Sullivan, Brian D.

1998-01-01

Canada geese (Branta canadensis) have been managed largely as a migratory resource. In the 1960's, Canada goose flocks were restored to historic breeding ranges in the United States and southern Canada to enhance recreational opportunity for observation and harvest. These populations of southern breeding geese have rapidly expanded, increasing conflicts with social and economic interests and causing the Midwinter Waterfowl Survey to be less effective as a management tool to monitor migrant populations. Wildlife agencies need methods to control local, southern breeding geese that reduce conflicts while providing adequate protection to populations of northern breeding geese. New techniques have been developed using mark-resight data from neck-banded geese to estimate distribution and population size during the late summer, fall, and mid-winter. Survival and movement rates can be estimated over special early or late hunting seasons, traditional fall-winter hunting season, and nonharvest periods. Direct recovery rates can be estimated for special and traditional harvest periods and these recovery rates can be related to survival and movement rates. Changes in harvest regulations can be related to changes in recovery, survival, and movement rates for specific cohorts of Canada geese. These techniques can be used to monitor population status and determine more appropriate harvest strategies.

Morphofunctional evaluation of the testicle and the spermatogenic process of adult white-eyed parakeets (Aratinga leucophthalma MULLER, 1776) during the different seasons of the year.

PubMed

Peixoto, J V; Paula, T A R; Balarini, M K; Matta, S L P; Santos, J A D; Lima, C B; Peixoto, G V

2012-08-01

In this experiment, testicle fragments of 14 adult White-eyed Parakeets (Aratinga leucophthalma) were evaluated as for their seasonal reproductive activities using the following quantitative parameters: average thickness of the testicular tunica albuginea, volumetric proportion of tubular and extratubular compartments, average diameter of the seminiferous tubules and corporal weight. Parameters were created for qualitative evaluations of the degree of spermatogenic development. In this experiment, all the animals were distributed into four groups, and their testicular fragments were collected during the middle of summer, fall, winter and spring. The animals were submitted to volatile general anaesthesia, and a biopsy was made by celioscopy. The fragments collected were processed histologically. The slides were prepared and later evaluated by using an optical microscope. The average seasonal values of the corporal weight increased, starting in the winter and reaching the peak during the spring. A seasonal testicle cycle was observed, because, in the spring, the testicles showed values for the quantitative and qualitative parameters of spermatic production compatible with the period of greater activity, while the opposite thing happened during the fall. Our data indicate that the parameters of sperm production may be correlated with daily light rather than with air humidity. © 2012 Blackwell Verlag GmbH.

Exploration of diarrhoea seasonality and its drivers in China.

PubMed

Xu, Zhiwei; Hu, Wenbiao; Zhang, Yewu; Wang, Xiaofeng; Zhou, Maigeng; Su, Hong; Huang, Cunrui; Tong, Shilu; Guo, Qing

2015-02-04

This study investigated the diarrhoea seasonality and its potential drivers as well as potential opportunities for future diarrhoea control and prevention in China. Data on weekly infectious diarrhoea cases in 31 provinces of China from 2005 to 2012, and data on demographic and geographic characteristics, as well as climatic factors, were complied. A cosinor function combined with a Poisson regression was used to calculate the three seasonal parameters of diarrhoea in different provinces. Regression tree analysis was used to identify the predictors of diarrhoea seasonality. Diarrhoea cases in China showed a bimodal distribution. Diarrhoea in children <5 years was more likely to peak in fall-winter seasons, while diarrhoea in persons > = 5 years peaked in summer. Latitude was significantly associated with spatial pattern of diarrhoea seasonality, with peak and trough times occurring earlier at high latitudes (northern areas), and later at low latitudes (southern areas). The annual amplitudes of diarrhoea in persons > = 5 years increased with latitude (r = 0.62, P<0.001). Latitude 27.8° N and 38.65° N were the latitudinal thresholds for diarrhoea seasonality in China. Regional-specific diarrhoea control and prevention strategies may be optimal for China. More attention should be paid to diarrhoea in children <5 years during fall-winter seasons.

Nitrogen transformations in response to temperature and rainfall manipulation in oak savanna: A global change experiment

NASA Astrophysics Data System (ADS)

Wellman, R. L.; Boutton, T. W.; Tjoelker, M. G.; Volder, A.; Briske, D. D.

2013-12-01

Increasing concentrations of greenhouse gases are projected to elevate global surface air temperatures by 1.1 to 6.4°C by the end of the century, and potentially magnify the intensity and variability of seasonal precipitation distribution. The mid-latitude grasslands of North America are predicted to experience substantial modification in precipitation regimes, with a shift towards drier summers and wetter spring and fall seasons. Despite these predictions, little is known concerning the effects of these global climate change drivers or their potential interactive effects on nitrogen (N) cycling processes. The purpose of this study is to quantify seasonal variation in rates of N-mineralization, nitrification, and N-losses via leaching in soil subjected to experimental warming and rainfall manipulation. Research was conducted at the Texas A&M Warming and Rainfall Manipulation (WaRM) Site in College Station where eight 9x18m rainout shelters and two unsheltered controls were established in post oak savanna in 2003. Replicate annual rainfall redistribution treatments (n = 4) are applied at the shelter level (long term mean vs. 40% of summer redistributed to fall and spring with same annual total). Warming treatments (ambient vs. 24-hr IR canopy warming of 1-3°C) were applied to planted monocultures of juniper and little bluestem, and a juniper-grass combination. Both juniper and little bluestem are key species within the post oak savanna region. Plots were sampled from the full factorial design during years six and seven of the WaRM experiment. Soil N-mineralization, nitrification, and N-losses via leaching were assessed quarterly for two years using the resin core incubation method. Rainfall, species composition, and time interacted significantly to influence both ammonification and nitrification. Highest rates of ammonification (0.115 mg NH4+ -N/ kg soil/day) occurred in grass monocultures during summer in the control rainfall plots, whereas highest rates of nitrification (1.581 mg NO2-/NO3- -N/ kg soil/day) were in juniper monocultures during fall and spring in redistributed rainfall treatments. Lowest rates of ammonification (0.002 mg NH4+ -N/ kg soil/day) occurred under grass during fall and winter in redistributed rainfall plots, while lowest rates of nitrification (-0.016 mg NO2-/NO3- -N/ kg soil/day) were in juniper-grass mixtures during fall and winter in redistributed rainfall plots. Losses of N through leaching were highest in the same treatment combinations that had high rates of nitrification. Results indicate that while rainfall redistribution interacted strongly with other experimental treatments to influence rates of N-transformations, warming had little effect. These changes in rates of N-transformations and leaching losses in response to global change drivers may have important implications for net primary production, soil fertility, carbon storage, trace gas fluxes, water quality, interspecific interactions, and vegetation dynamics in the oak savanna region of North America.

Salmonella survival in manure-treated soils during simulated seasonal temperature exposure.

PubMed

Holley, Richard A; Arrus, Katia M; Ominski, Kimberly H; Tenuta, Mario; Blank, Gregory

2006-01-01

Addition of animal manure to soil can provide opportunity for Salmonella contamination of soil, water, and food. This study examined how exposure of hog manure-treated loamy sand and clay soils to different simulated seasonal temperature sequences influenced the length of Salmonella survival. A six-strain cocktail of Salmonella serovars (Agona, Hadar, Heidelberg, Montevideo, Oranienburg, and Typhimurium) was added to yield 5 log cfu/g directly to about 5 kg of the two soils and moisture adjusted to 60 or 80% of field capacity (FC). Similarly, the Salmonella cocktail was mixed with fresh manure slurry from a hog nursery barn and the latter added to the two soils at 25 g/kg to achieve 5 log cfu/g Salmonella. Manure was mixed either throughout the soil or with the top kilogram of soil and the entire soil volume was adjusted to 60 or 80% FC. Soil treatments were stored 180 d at temperature sequences representing winter to summer (-18, 4, 10, 25 degrees C), spring to summer (4, 10, 25, 30 degrees C), or summer to winter (25, 10, 4, -18 degrees C) seasonal periods with each temperature step lasting 45 d. Samples for Salmonella recovery by direct plating or enrichment were taken at 0, 7, and 15 d post-inoculation and thereafter at 15-d intervals to 180 d. Salmonella numbers decreased during application to soil and the largest decreases occurred within the first week. Higher soil moisture, manure addition, and storage in the clay soil increased Salmonella survival. Salmonella survived longest (> or = 180 d) in both soils during summer-winter exposure but was not isolated after 160 d from loamy sand soil exposed to other seasonal treatments. For all but one treatment decimal reduction time (DRT45d) values calculated from the first 45 d after application were < or = 30 d and suggested that a 30-d delay between field application of manure in the spring or fall and use of the land would provide reasonable assurance that crop and animal contamination by Salmonella would be minimized.

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

NASA Astrophysics Data System (ADS)

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 (P<0.05) of 0.25 (SD 0.61) °C in the morning and 0.24 (SD 0.50) °C in the afternoon. Differences between oral temperatures in summer and winter tended to be greater in subjects with low ADL scores, even when their room temperature was well-controlled. In conclusion, the oral temperatures of the elderly are lower in winter than summer, particularly in physically inactive people. It appears that those with low levels of ADL are more vulnerable to large changes in ambient temperature.

Precipitation regime classification for the Mojave Desert: Implications for fire occurrence

USGS Publications Warehouse

Tagestad, Jerry; Brooks, Matthew L.; Cullinan, Valerie; Downs, Janelle; McKinley, Randy

2016-01-01

Long periods of drought or above-average precipitation affect Mojave Desert vegetation condition, biomass and susceptibility to fire. Changes in the seasonality of precipitation alter the likelihood of lightning, a key ignition source for fires. The objectives of this study were to characterize the relationship between recent, historic, and future precipitation patterns and fire. Classifying monthly precipitation data from 1971 to 2010 reveals four precipitation regimes: low winter/low summer, moderate winter/moderate summer, high winter/low summer and high winter/high summer. Two regimes with summer monsoonal precipitation covered only 40% of the Mojave Desert ecoregion but contain 88% of the area burned and 95% of the repeat burn area. Classifying historic precipitation for early-century (wet) and mid-century (drought) periods reveals distinct shifts in regime boundaries. Early-century results are similar to current, while the mid-century results show a sizeable reduction in area of regimes with a strong monsoonal component. Such a shift would suggest that fires during the mid-century period would be minimal and anecdotal records confirm this. Predicted precipitation patterns from downscaled global climate models indicate numerous epochs of high winter precipitation, inferring higher fire potential for many multi-decade periods during the next century.

Lysosomal responses to heat-shock of seasonal temperature extremes in Cd-exposed mussels.

PubMed

Múgica, M; Izagirre, U; Marigómez, I

2015-07-01

The present study was aimed at determining the effect of temperature extremes on lysosomal biomarkers in mussels exposed to a model toxic pollutant (Cd) at different seasons. For this purpose, temperature was elevated 10°C (from 12°C to 22°C in winter and from 18°C to 28°C in summer) for a period of 6h (heat-shock) in control and Cd-exposed mussels, and then returned back to initial one. Lysosomal membrane stability and lysosomal structural changes in digestive gland were investigated. In winter, heat-shock reduced the labilisation period (LP) of the lysosomal membrane, especially in Cd-exposed mussels, and provoked transient lysosomal enlargement. LP values recovered after the heat-shock cessation but lysosomal enlargement prevailed in both experimental groups. In summer, heat-shock induced remarkable reduction in LP and lysosomal enlargement (more markedly in Cd-exposed mussels), which recovered within 3 days. Besides, whilst heat-shock effects on LP were practically identical for Cd-exposed mussels in winter and summer, the effects were longer-lasting in summer than in winter for control mussels. Thus, lysosomal responsiveness after heat-shock was higher in summer than in winter but recovery was faster as well, and therefore the consequences of the heat shock seem to be more decisive in winter. In contrast, inter-season differences were attenuated in the presence of Cd. Consequently, mussels seem to be better prepared in summer than in winter to stand short periods of abrupt temperature change; this is, however, compromised when mussels are exposed to pollutants such as Cd. Copyright © 2015 Elsevier B.V. All rights reserved.

The Effect of Seasonal Thermal Stress on Lipid Mobilisation, Antioxidant Status and Reproductive Performance in Dairy Cows.

PubMed

Turk, R; Podpečan, O; Mrkun, J; Flegar-Meštrić, Z; Perkov, S; Zrimšek, P

2015-08-01

Heat stress is a major factor contributing to low fertility of dairy cows with a great economic impact in dairy industry. Heat-stressed dairy cows usually have reduced nutrient intake, resulting in a higher degree of negative energy balance (NEB). The aim of this study was to investigate the seasonal thermal effect on lipid metabolism, antioxidant activity and reproductive performance in dairy cows. Thirty-two healthy dairy heifers were included in the study. According to the ambient temperature, animals were divided into two groups: winter (N = 14) and summer season (N = 18). Metabolic parameters, paraoxonase-1 (PON1) activity and total antioxidant status (TAS) were monitored at the time of insemination (basal values) and from 1 week before until 8 weeks after calving. Number of services per conception and calving-to-conception (CC) interval were calculated from the farm recording data. Serum triglyceride, non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB) concentrations were significantly increased after calving in summer compared to winter, indicating higher degree of NEB in cows during summer. PON1 activity was significantly decreased after calving in both summer and winter group. TAS concentration was significantly lower in summer than that in winter. A significantly higher number of services were needed for conception in summer compared to winter, and CC interval was significantly longer in summer than that in winter as well. Additionally, reproductive performance significantly correlated with the severity of NEB, suggesting that lipid mobilization and lower antioxidant status contributed to poor reproduction ability in dairy cows during hot months. © 2015 Blackwell Verlag GmbH.

Distribution of Different Biogeographical Tintinnids in Yellow Sea and Bohai Sea

NASA Astrophysics Data System (ADS)

Chen, Xue; Li, Haibo; Zhao, Yuan; Zhao, Li; Dong, Yi; Zhang, Wuchang; Xiao, Tian

2018-04-01

There were different biogeographical tintinnids in the oceans. Knowledge of their distribution pattern and mixing was important to the understanding of ecosystem functions. Yellow Sea (YS) and Bohai Sea (BS) were semi-enclosed seas influenced by warm water intrusion and YS cold bottom water. The occurrence of tintinnids in YS and BS during two cruises (summer and winter) were investigated to find out: i) whether warm-water tintinnids appeared in YS and BS; ii) whether boreal tintinnids appeared in high summer; iii) the core area of neritic tintinnids and iv) how these different biogeographical tintinnids mixed. Our results showed that tintinnid community was dominated by neritic tintinnid. We confirmed the occurrence of warm-water tintinnids in summer and winter. In summer, they intruded into BS and mainly distributed in the upper 20 m where Yellow Sea Surface Warm Water (YSSWW) developed. In winter, they were limited in the surface water of central deep region (bottom depth >50 m) of YS where were affected by Yellow Sea Warm Water (YSWW). Boreal tintinnids occurred in YS in high summer (August) and in winter, while they were not observed in BS. In summer, the highest abundance of boreal tintinnids occurred in Yellow Sea Bottom Cold Water, indicating the presence of an oversummering stock. In winter, they were concentrated in the north of YSWW. Vertically, neritic tintinnids abundance was high in the bottom layers. Horizontally, high neritic tintinnids abundance in bottom layers occurred along the 50 m isobath coinciding with the position of front systems. Front systems were the core distribution area of neritic tintinnids. High abundance areas of warm-water and boreal tintinnids were clearly separated vertically in summer, and horizontally in winter. High abundance of neritic tintinnids rarely overlapped with that of warm-water or boreal tintinnids.

Forage kochia (Kochia Prostrata) increases nutritional value, carrying capacity, and livestock performance on semiarid rangelands

USDA-ARS?s Scientific Manuscript database

Extending the grazing season into the fall and winter increases the sustainability of livestock production by reducing winter feed costs. However, without exception, stockpiled range grasses do not meet nutritional requirements for ruminant livestock. This study compared fall/winter grazing of tra...

Grazing management for fall-grown oat forages

USDA-ARS?s Scientific Manuscript database

Fall forage production of oat generally will out-yield winter wheat or cereal rye by about a 2:1 ratio, regardless of weather conditions or harvest date because oat plants will joint, elongate, and produce a seedhead before winter, while winter wheat or cereal rye will remain vegetative until spring...

Subsurface low dissolved oxygen occurred at fresh- and saline-water intersection of the Pearl River estuary during the summer period.

PubMed

Li, Gang; Liu, Jiaxing; Diao, Zenghui; Jiang, Xin; Li, Jiajun; Ke, Zhixin; Shen, Pingping; Ren, Lijuan; Huang, Liangmin; Tan, Yehui

2018-01-01

Estuarine oxygen depletion is one of the worldwide problems, which is caused by the freshwater-input-derived severe stratification and high nutrients loading. In this study we presented the horizontal and vertical distributions of dissolved oxygen (DO) in the Pearl River estuary, together with temperature, salinity, chlorophyll a concentration and heterotrophic bacteria abundance obtained from two cruises during the summer (wet) and winter (dry) periods of 2015. In surface water, the DO level in the summer period was lower and varied greater, as compared to the winter period. The DO remained unsaturated in the summer period if salinity is <12 and saturated if salinity is >12; while in the winter period it remained saturated throughout the estuary. In subsurface (>5m) water, the DO level varied from 0.71 to 6.65mgL -1 and from 6.58 to 8.20mgL -1 in the summer and winter periods, respectively. Particularly, we observed an area of ~1500km 2 low DO zone in the subsurface water with a threshold of 4mgDOL -1 during this summer period, that located at the fresh- and saline-water intersection where is characterized with severe stratification and high heterotrophic bacteria abundance. In addition, our results indicate that spatial DO variability in surface water was contributed differently by biological and physio-chemical variables in the summer and winter periods, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Precipitation chemistry along an inland transect on the Olympic Peninsula, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blew, R.D.; Edmonds, R.L.

1995-03-01

The objective of this study was to examine oceanic influences, seasonal variation, and effect of distance from the ocean on the chemistry of bulk precipitation falling on the Pacific coast of Washington State. Bulk precipitation was collected at Sites 4, 13, 24, and 31 km inland from the Pacific Ocean. Mean electrical conductivity of precipitation ranged from 0.47 to 1.02 mS m{sup -1} and mean pH ranged from 5.3 to 5.6. Annual precipitation increased from 2780 mm at 4 km to approximately 3500 mm at 13 km from the coast and remained constant through 31 km inland. Precipitation was highestmore » in the late fall and winter months and lowest during the summer. Rates of ion deposition had a similar seasonal pattern to that of precipitation. Concentrations of Cl, SO{sub 4}, Mg, Na, and excess Ca (Ca in excess of expected sea salt levels) were highest nearest to the coast and were reflected in higher electrical conductivity in precipitation falling closets to the coast.« less

Are winter and summer dormancy symmetrical seasonal adaptive strategies? The case of temperate herbaceous perennials

PubMed Central

Gillespie, Lauren M.; Volaire, Florence A.

2017-01-01

Background Dormancy in higher plants is an adaptive response enabling plant survival during the harshest seasons and has been more explored in woody species than in herbaceous species. Nevertheless, winter and summer shoot meristem dormancy are adaptive strategies that could play a major role in enhancing seasonal stress tolerance and resilience of widespread herbaceous plant communities. Scope This review outlines the symmetrical aspects of winter and summer dormancy in order to better understand plant adaptation to severe stress, and highlight research priorities in a changing climate. Seasonal dormancy is a good model to explore the growth–stress survival trade-off and unravel the relationships between growth potential and stress hardiness. Although photoperiod and temperature are known to play a crucial, though reversed, role in the induction and release of both types of dormancy, the thresholds and combined effects of these environmental factors remain to be identified. The biochemical compounds involved in induction or release in winter dormancy (abscisic acid, ethylene, sugars, cytokinins and gibberellins) could be a priority research focus for summer dormancy. To address these research priorities, herbaceous species, being more tractable than woody species, are excellent model plants for which both summer and winter dormancy have been clearly identified. Conclusions Summer and winter dormancy, although responding to inverse conditions, share many characteristics. This analogous nature can facilitate research as well as lead to insight into plant adaptations to extreme conditions and the evolution of phenological patterns of species and communities under climate change. The development of phenotypes showing reduced winter and/or enhanced summer dormancy may be expected and could improve adaptation to less predictable environmental stresses correlated with future climates. To this end, it is suggested to explore the inter- and intraspecific genotypic variability of dormancy and its plasticity according to environmental conditions to contribute to predicting and mitigating global warming. PMID:28087658

Summer/winter differences in the serum 25-hydroxyvitamin D3 and parathyroid hormone levels of Japanese women

NASA Astrophysics Data System (ADS)

Nakamura, K.; Nashimoto, Mitsue; Yamamoto, Masaharu

Serum 25-hydroxyvitamin D3 [25(OH)D3] is produced in the skin in response to exposure to ultraviolet radiation, and is a good indicator of vitamin D nutritional status. The aim of this study was to determine summer/winter differences in serum 25(OH)D3 and parathyroid hormone (PTH) in Japanese women and how the summer and winter values are related. The subjects were 122 healthy Japanese women aged 45-81 years (average age: 65.7 years). They were medically examined twice, in September 1997 and February 1999. Serum 25(OH)D3 and intact PTH were determined by high-performance liquid chromatography and a two-site immunoradiometric assay respectively. Lifestyle information was obtained through an interview. The seasonal differences (winter minus summer) in 25(OH)D3 [Δ25(OH)D3] and intact PTH concentrations were -18.8 nmol/l (SD 19.2, P<0.0001) and 0.98pmol/l (SD 1.02, P<0.0001) respectively. The correlation coefficient between summer (x) and winter (y) 25(OH)D3 levels was 0.462 (P<0.0001), with a linearly fitted line of y=0.42x+26.4. This relationship was interpreted as subjects with higher summer 25(OH)D3 values having greater reductions in winter 25(OH)D3 concentrations. There were inter-individual differences in Δ25(OH)D3, although the summer and winter 25(OH)D3 concentrations were well-correlated. Since Δ25(OH)D3 was not associated with any of the lifestyle factors, seasonal differences in the 25(OH)D3 concentrations of an individual appeared to reflect her ability to produce 25(OH)D3 photochemically in the skin. Sun bathing would be a less effective means of attaining adequate vitamin D nutritional status in a person with a small seasonal difference in 25(OH)D3, i.e., one with a low 25(OH)D3 level.

Water-soluble ions measured in fine particulate matter next to cement works

NASA Astrophysics Data System (ADS)

Galindo, N.; Yubero, E.; Nicolás, J. F.; Crespo, J.; Pastor, C.; Carratalá, A.; Santacatalina, M.

2011-04-01

PM2.5 samples were collected for one year in a suburban area close to an industrial complex formed by two cement factories and some quarries in southeastern Spain. Samples were analyzed by ion chromatography to determine the concentrations of major inorganic ions: Cl -, NO 3-, SO 42-, Na +, NH 4+, K +, Mg 2+ and Ca 2+. The average PM2.5 concentration (17.6 μg m -3) was within the interval reported for other Mediterranean suburban environments. Concentration peaks were registered during both winter and summer, concurrently with maxima levels of nitrate and sulfate, due to stagnation conditions and African dust episodes, respectively. Sulfate was found to be a main contributor to PM2.5 aerosol mass (4.2 μg m -3, 24%), followed by nitrate and ammonium (1.5 μg m -3, 9% each one). Correlation analyses demonstrated that fine sulfate was present as (NH 4) 2SO 4, CaSO 4 and Na 2SO 4 since ammonium concentrations were not high enough to neutralize both anions. The mean concentration of calcium (1.0 μg m -3), an element commonly found in the coarse fraction, was higher than those found in other locations of the Mediterranean basin. Additionally, the lowest levels were registered during summer, in contrast with previous findings. This was attributed to resuspension and transport of mineral dust from the neighboring quarries and cement plants during fall and winter, which was supported by the results of the CPF analysis. Atmospheric levels of potassium and chloride (0.28 and 0.51 μg m -3 annual average, respectively) also seemed to be affected by cement works, as suggested by correlation and CPF analyses. In the case of Cl -, a marked seasonality was observed, with mean winter concentrations considerably higher than summer ones, indicating a clear prevalence of anthropogenic sources over sea spray emissions.

Seasonal variation of assemblage and feeding guild structure of fish species in a boreal tidal basin

NASA Astrophysics Data System (ADS)

Kellnreitner, Florian; Pockberger, Moritz; Asmus, Harald

2012-08-01

Species composition, abundance, feeding relationships and guild structure of the fish assemblage in the Sylt-Rømø bight, a tidal basin in the northern Wadden Sea, were investigated to show seasonal differences and the importance of functional groups in this area. The tidal flats and in shallow subtidal areas were sampled using a beach seine and a bottom trawl net was used for deeper subtidal areas and tidal gullies. Species richness of fish was highest in summer where 26 species were caught, while the lowest richness was recorded in winter (17 species). Clear differences in species richness and abundance were found between shallow areas and deeper parts of the bight. Clupea harengus and Ammodytes tobianus were the most abundant species in deeper areas, while Pomatoschistus microps and Pomatoschistus minutus dominated shallower waters. Gut contents of 27 fish species were identified and the guild structure analyzed by UPGMA clustering of niche overlaps. Calanoid copepods (19.9%), Crangon crangon (18.2%) and mysid shrimps (8.4%) were the most abundant prey items of all fish species combined. Seven feeding guilds were present in the fall and winter, and eight and six in spring and summer, respectively. Fish feeding on calanoid copepods and C. crangon were present year round, whereas the occurrence of other guilds varied between seasons. Species composition of prey changed through seasons and, for some fish species, even the feeding mode itself varied with season. Most noticeable, 11 fish species changed guilds between seasons. We found a convergence in summer towards abundant prey items, whereas in winter diet overlap was lower. This is the first investigation of guild structure of almost all fish species present in a Wadden Sea area, and shows that consideration of seasonal differences is essential when determining feeding relationships of fish in temperate areas.

Progress Report: Stratton Ecological Research Site - An Experimental Approach to Assess Effects of Various Grazing Treatments on Vegetation and Wildlife Communities Across Managed Burns and Habitat Controls

USGS Publications Warehouse

Erickson, Heidi J.; Aldridge, Cameron L.; Hobbs, N. Thompson

2009-01-01

Understanding how management practices affect wildlife is fundamental to wise decisions for conservation of public lands. Prescribed fire and grazing timing are two management tools frequently used within publicly owned sagebrush ecosystems. We conducted a variety of surveys in order to assess the impacts of grazing timing strategies (early summer before peak green-up, mid-summer at peak green-up, and late summer after peak green-up) in conjunction with prescribed fire on avian and small mammal populations in a high-elevation sagebrush ecosystem. Avian surveys resulted in a large detection sample size for three bird species: Brewer's sparrow (Spizella breweri), horned lark (Eremophila alpestris), and vesper sparrow (Pooecetes gramineus). Brewer's sparrows had the lowest number of detections within the mid-summer grazing treatment compared to early and late summer grazing treatments, while horned larks and vesper sparrows had higher detection frequencies within the late summer grazing treatment. Summer and fall sage-grouse (Centrocercus urophasianus) pellet counts revealed that the greatest over-winter and over-summer use by sage-grouse occurred within the early summer grazing treatment with minimal use of burn treatment areas across all grazing treatments. Deer-mice (Peromyscus maniculatus) represented approximately 90 percent of small mammals captured and were most prevalent within the mid-summer grazing treatment. Sagebrush cover was greatest within the mid-summer grazing treatment. We monitored 50 and 103 nests in 2007 and 2008, respectively. The apparent success rate for shrub-obligate nesting species was 58 percent in 2007 and 63 percent in 2008. This research will support management of sagebrush ecosystems by providing public land managers with direct comparisons of wildlife response to management regimes.

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

NASA Astrophysics Data System (ADS)

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

High Resolution Hydro-climatological Projections for Western Canada

NASA Astrophysics Data System (ADS)

Erler, Andre Richard

Accurate identification of the impact of global warming on water resources and hydro-climatic extremes represents a significant challenge to the understanding of climate change on the regional scale. Here an analysis of hydro-climatic changes in western Canada is presented, with specific focus on the Fraser and Athabasca River basins and on changes in hydro-climatic extremes. The analysis is based on a suite of simulations designed to characterize internal variability, as well as model uncertainty. A small ensemble of Community Earth System Model version 1 (CESM1) simulations was employed to generate global climate projections, which were downscaled to 10 km resolution using the Weather Research and Forecasting model (WRF V3.4.1) with several sets of physical parameterizations. Downscaling was performed for a historical validation period and a mid- and end-21st-century projection period, using the RCP8.5 greenhouse gas trajectory. Daily station observations and monthly gridded datasets were used for validation. Changes in hydro-climatic extremes are characterized using Extreme Value Analysis. A novel method of aggregating data from climatologically similar stations was employed to increase the statistical power of the analysis. Changes in mean and extreme precipitation are found to differ strongly between seasons and regions, but (relative) changes in extremes generally follow changes in the (seasonal) mean. At the end of the 21st century, precipitation and precipitation extremes are projected to increase by 30% at the coast in fall and land-inwards in winter, while the projected increase in summer precipitation is smaller and changes in extremes are often not statistically significant. Reasons for the differences between seasons, the role of precipitation recycling in atmospheric water transport, and the sensitivity to physics parameterizations are discussed. Major changes are projected for the Fraser River basin, including earlier snowmelt and a 50% reduction in peak runoff. Combined with higher evapotranspiration, a significant increase in late summer drought risk is likely, but increasing fall precipitation might also increase the risk of moderate flooding. In the Athabasca River basin, increasing winter precipitation and snowmelt is balanced by increasing evapotranspiration in summer and no significant change in flood or drought risk is projected.

Seasonal patterns in nutrients, carbon, and algal responses in wadeable streams within three geographically distinct areas of the United States, 2007-08

USGS Publications Warehouse

Lee, Kathy E.; Lorenz, David L.; Petersen, James C.; Greene, John B.

2012-01-01

The U.S. Geological Survey determined seasonal variability in nutrients, carbon, and algal biomass in 22 wadeable streams over a 1-year period during 2007 or 2008 within three geographically distinct areas in the United States. The three areas are the Upper Mississippi River Basin (UMIS) in Minnesota, the Ozark Plateaus (ORZK) in southern Missouri and northern Arkansas, and the Upper Snake River Basin (USNK) in southern Idaho. Seasonal patterns in some constituent concentrations and algal responses were distinct. Nitrate concentrations were greatest during the winter in all study areas potentially because of a reduction in denitrification rates and algal uptake during the winter, along with reduced surface runoff. Decreases in nitrate concentrations during the spring and summer at most stream sites coincided with increased streamflow during the snowmelt runoff or spring storms indicating dilution. The continued decrease in nitrate concentrations during summer potentially is because of a reduction in nitrate inputs (from decreased surface runoff) or increases in biological uptake. In contrast to nitrate concentrations, ammonia concentrations varied among study areas. Ammonia concentration trends were similar at UMIS and USNK sampling sites with winter peak concentrations and rapid decreases in ammonia concentrations by spring or early summer. In contrast, ammonia concentrations at OZRK sampling sites were more variable with peak concentrations later in the year. Ammonia may accumulate in stream water in the winter under ice and snow cover at the UMIS and USNK sites because of limited algal metabolism and increased mineralization of decaying organic matter under reducing conditions within stream bottom sediments. Phosphorus concentration patterns and the type of phosphorus present changes with changing hydrologic conditions and seasons and varied among study areas. Orthophosphate concentrations tended to be greater in the summer at UMIS sites, whereas total phosphorus concentrations at most UMIS and USNK sites peaked in the spring during runoff and then decreased through the remainder of the sampling period. Total phosphorus and orthophosphate concentrations in OZRK streams peaked during summer indicating a runoff-based source of both nutrients. Orthophosphate concentrations may increase in streams in the late summer when surface runoff composes less of total streamflow, and when groundwater containing orthophosphate becomes a more dominant source in streams during lower flows. Seston chlorophyll a concentrations were greatest early in the growing season (spring), whereas the spring runoff events coincided with reductions in benthic algal chlorophyll a biomass likely because of scour of benthic algae from the channel bottom that are entrained in the water column during that period. Nitrate, ammonia, and orthophosphate concentrations also decreased during that same period, indicating dilution in the spring during runoff events. The data from this study indicate that the source of water (surface runoff or groundwater) to a stream and the intensity of major runoff events are important factors controlling instream concentrations. Biological processes appear to affect nutrient concentrations during more stable lower flow periods in later summer, fall, and winter when residence time of water in a channel is longer, which allows more time for biological uptake and transformations. Management of nutrient conditions in streams is challenging and requires an understanding of multiple factors that affect in-stream nutrient concentrations and biological uptake and growth.

Comparison of the effect of land-sea thermal contrast on interdecadal variations in winter and summer blockings

NASA Astrophysics Data System (ADS)

He, Yongli; Huang, Jianping; Li, Dongdong; Xie, Yongkun; Zhang, Guolong; Qi, Yulei; Wang, Shanshan; Totz, Sonja

2017-11-01

The influence of winter and summer land-sea surface thermal contrast on blocking for 1948-2013 is investigated using observations and the coupled model intercomparison project outputs. The land-sea index (LSI) is defined to measure the changes of zonal asymmetric thermal forcing under global warming. The summer LSI shows a slower increasing trend than winter during this period. For the positive of summer LSI, the EP flux convergence induced by the land-sea thermal forcing in the high latitude becomes weaker than normal, which induces positive anomaly of zonal-mean westerly and double-jet structure. Based on the quasiresonance amplification mechanism, the narrow and reduced westerly tunnel between two jet centers provides a favor environment for more frequent blocking. Composite analysis demonstrates that summer blocking shows an increasing trend of event numbers and a decreasing trend of durations. The numbers of the short-lived blocking persisting for 5-9 days significantly increases and the numbers of the long-lived blocking persisting for longer than 10 days has a weak increase than that in negative phase of summer LSI. The increasing transient wave activities induced by summer LSI is responsible for the decreasing duration of blockings. The increasing blocking due to summer LSI can further strengthen the continent warming and increase the summer LSI, which forms a positive feedback. The opposite dynamical effect of LSI on summer and winter blocking are discussed and found that the LSI-blocking negative feedback partially reduces the influence of the above positive feedback and induce the weak summer warming rate.

On the Dominant Factor Controlling Seasonal Hydrological Forecast Skill in China

DOE PAGES

Zhang, Xuejun; Tang, Qiuhong; Leng, Guoyong; ...

2017-11-20

Initial conditions (ICs) and climate forecasts (CFs) are the two primary sources of seasonal hydrological forecast skill. However, their relative contribution to predictive skill remains unclear in China. In this study, we investigate the relative roles of ICs and CFs in cumulative runoff (CR) and soil moisture (SM) forecasts using 31-year (1980–2010) ensemble streamflow prediction (ESP) and reverse-ESP (revESP) simulations with the Variable Capacity Infiltration (VIC) hydrologic model. The results show that the relative importance of ICs and CFs largely depends on climate regimes. The influence of ICs is stronger in a dry or wet-to-dry climate regime that covers themore » northern and western interior regions during the late fall to early summer. In particular, ICs may dominate the forecast skill for up to three months or even six months during late fall and winter months, probably due to the low precipitation value and variability in the dry period. In contrast, CFs become more important for most of southern China or during summer months. The impact of ICs on SM forecasts tends to cover larger domains than on CR forecasts. These findings will greatly benefit future work that will target efforts towards improving current forecast levels for the particular regions and forecast periods.« less

On the Dominant Factor Controlling Seasonal Hydrological Forecast Skill in China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xuejun; Tang, Qiuhong; Leng, Guoyong

Initial conditions (ICs) and climate forecasts (CFs) are the two primary sources of seasonal hydrological forecast skill. However, their relative contribution to predictive skill remains unclear in China. In this study, we investigate the relative roles of ICs and CFs in cumulative runoff (CR) and soil moisture (SM) forecasts using 31-year (1980–2010) ensemble streamflow prediction (ESP) and reverse-ESP (revESP) simulations with the Variable Capacity Infiltration (VIC) hydrologic model. The results show that the relative importance of ICs and CFs largely depends on climate regimes. The influence of ICs is stronger in a dry or wet-to-dry climate regime that covers themore » northern and western interior regions during the late fall to early summer. In particular, ICs may dominate the forecast skill for up to three months or even six months during late fall and winter months, probably due to the low precipitation value and variability in the dry period. In contrast, CFs become more important for most of southern China or during summer months. The impact of ICs on SM forecasts tends to cover larger domains than on CR forecasts. These findings will greatly benefit future work that will target efforts towards improving current forecast levels for the particular regions and forecast periods.« less

Lake Energy Budget and Temperature Profiles Under Future Greenhouse Gas Scenarios

NASA Astrophysics Data System (ADS)

Lofgren, B. M.; Xiao, C.

2017-12-01

Future climates under higher concentrations of greenhouse gases are expected to feature higher air and water temperatures, and shifts in surface heat fluxes. We investigate in greater detail the evolution of this in terms of the annual cycle of lake temperature profiles, stratification, and ice formation. Other work has found that, although shallower water promotes more rapid changes in surface water temperature within a season, change in surface water temperature across decades is more prominent in locations with greater water depth. Our simulations using the Weather Research and Forecasting (WRF) model and its lake module, WRF-Lake, show a trend toward longer periods of summer stratification, both through earlier onset in the spring and later decay of stratification in the fall. They also show a general increase in temperature throughout the water column, but most pronounced near the surface during the summer. Likewise, ice duration is much shorter and more restricted to shallow embayments. High latent and sensible heat flux during the fall and winter are less intense but longer lasting under the future scenario. Sources of uncertainty are cumulative—actual future greenhouse gas concentrations, global sensitivity of climate change, cloud feedbacks, the combined formulation of the regional climate model (WRF) and its global driving model, and more.

The effect of aromatherapy massage with music on the stress and anxiety levels of emergency nurses: comparison between summer and winter.

PubMed

Cooke, Marie; Holzhauser, Kerri; Jones, Mark; Davis, Cathy; Finucane, Julie

2007-09-01

This research aimed to evaluate the use of aromatherapy massage and music as an intervention to cope with the occupational stress and anxiety that emergency department staff experience. The study also aimed to compare any differences in results between a summer and winter 12-week massage plan. Emergency nurses are subjected to significant stressors during their work and it is known that workloads and patient demands influence the role stress has on nurses. The perception that winter months are busier for emergency departments has long been held and there is some evidence that people with cardiac and respiratory dysfunction do present more frequently in the winter months. Massage has been found to decrease staff anxiety. The study used a one-group pre-test, post-test quasi-experimental design with random assignment. Staff occupational stress was assessed pre- and post- 12 weeks of aromatherapy massage with music and anxiety was measured pre and post each massage session. Sick leave was also measured. Comparisons of summer and winter data were undertaken. A total of 365 massages were given over two 12-week periods, one during summer and the other during winter. Analysis identified that aromatherapy massage with music significantly reduced anxiety for both seasonal periods. Premassage anxiety was significantly higher in winter than summer. No differences in sick leave and workload were found. There was no difference in the occupational stress levels of nurses following the two 12-week periods of massage. Emergency nurses were significantly more anxious in winter than summer but this cannot be attributed to increased sick leave or workloads. Aromatherapy massage with music significantly reduced emergency nurses' anxiety. High levels of anxiety and stress can be detrimental to the physical and emotional health of emergency nurses and the provision of a support mechanism such as on-site massage as an effective strategy should be considered.

Summer and winter time heterogeneity in aerosol single scattering albedo over the northwestern Atlantic Ocean during the TCAP field campaign: Relationship to chemical composition and mixing state

NASA Astrophysics Data System (ADS)

Berg, L. K.; Chand, D.; Fast, J. D.; Zelenyuk, A.; Wilson, J. M.; Sedlacek, A. J., III; Tomlinson, J. M.; Hubbe, J. M.; Comstock, J. M.; Mei, F.; Kassianov, E.; Schmid, B.

2015-12-01

Aerosol play crucial role in earth's radiative budget by scattering and absorbing solar radiation. The impact of aerosol on radiation budget depend on several factors including single scattering albedo (SSA), composition, and the growth processes, like coating or mixing. We describe findings relevant to optical properties of aerosol characterized over the Cape Cod and nearby northwest Atlantic Ocean during the Two Column Aerosol Project (TCAP) during the summer (July 2012) and winter (February 2013) campaigns. The average single scattering albedo (SSA) shows distinctly different vertical profiles during the summer and winter periods. During the summer study period, the average SSA is greater than 0.95 near surface, it increases to 0.97 until an altitude of 2.5 km, and then decreases to 0.94 at top of the column near 4 km. In contrast, during the winter study period the average SSA is less than 0.93 and decreases with height reaching an average value of 0.87 near the top of the column. The large difference in summer and winter time SSA is linked to the presence of biomass burning (BB) aerosol rather than black carbon or soot in both seasons. In our study, the BB on average is factor of two higher in free troposphere (FT) during summer and more than a factor of two higher in the boundary layer during winter. Single particle analysis indicates that the average profiles of refractory black carbon (rBC) mass are similar in both seasons. The average rBC size are similar at all altitudes sampled (0-4 km) in summer time but different during winter time. In addition, the particles sampled in the summertime FT appear to be more aged than those seen during winter. The observed large heterogeneity in SSA and its links to the particle coating and composition highlights the importance of aging and mixing processes of aerosol in this region and represents a challenge for both regional and global scale models.

Seasonal dependence of aerosol processing in urban Philadelphia

NASA Astrophysics Data System (ADS)

Avery, A. M.; Waring, M. S.; DeCarlo, P. F.

2017-12-01

Urban aerosols pose an important threat to human health due to the conflation of emissions and concentrated population exposed. Winter and summer aerosol and trace gas measurements were taken in downtown Philadelphia in 2016. Measurements included aerosol composition and size with an Aerodyne Aerosol Mass Spectrometer (AMS), particle size distributions with an SMPS, and an aethalometer. Trace gas measurements of O3, NO, CH4, CO, and CO2 were taken concurrently. Sampling in seasonal extremes provided contrast in aerosol and trace gas composition, aerosol processing, and emission factors. Inorganic aerosol components contributed approximately 60% of the submicron aerosol mass, while summertime aerosol composition was roughly 70% organic matter. Positive Matrix Factorization (PMF) on the organic aerosol (OA) matrix revealed three factors in common in each season, including an oxygenated organic aerosol (OOA) factor with different temporal behavior in each season. In summertime, OOA varied diurnally with ozone and daytime temperature, but in the wintertime, it was anti-correlated with ozone and temperature, and instead trended with calculated liquid water, indicating a seasonally-dependent processing of organic aerosol in Philadelphia's urban environment. Due to the inorganic dominant winter aerosol, liquid water much higher (2.65 μg/m3) in winter than in summer (1.54 μg/m3). Diurnally varying concentrations of background gas phase species (CH4, CO2) were higher in winter and varied less as a result of boundary layer conditions; ozone was also higher in background in winter than summer. Winter stagnation events with low windspeed showed large buildup of trace gases CH4, CO, CO2, and NO. Traffic related aerosol was also elevated with black carbon and hydrocarbon-like OA (HOA) plumes of each at 3-5 times higher than the winter the average value for each. Winter ratios of HOA to black carbon were significantly higher in the winter than the summer due to lower temperatures. Aerosol compositional differences in winter and summer indicate Philadelphia resident's aerosol exposures vary significantly with season.

Alkalinity production in intertidal sands intensified by lugworm bioirrigation.

PubMed

Rao, Alexandra M F; Malkin, Sairah Y; Montserrat, Francesc; Meysman, Filip J R

2014-07-05

Porewater profiles and sediment-water fluxes of oxygen, nutrients, pH, calcium, alkalinity, and sulfide were measured in intertidal sandflat sediments from the Oosterschelde mesotidal lagoon (The Netherlands). The influence of bioturbation and bioirrigation by the deep-burrowing polychaete Arenicola marina on the rates and sources of benthic alkalinity generation was examined by comparing measurements in intact and defaunated sediment cores before and after the addition of A. marina in summer and fall 2011. Higher organic matter remineralization rates, shallower O 2 penetration, and greater sediment-water solute fluxes were observed in summer, consistent with higher sediment community metabolic rates at a higher temperature. Lugworm activity stimulated porewater exchange (5.1 × in summer, 1.9 × in fall), organic matter remineralization (6.2 × in summer, 1.9 × in fall), aerobic respiration (2.4 × in summer, 2.1 × in fall), alkalinity release (4.7 × in summer, 4.0 × in fall), nutrient regeneration, and iron cycling. The effects of lugworm activity on net sediment-water fluxes were similar but more pronounced in summer than in fall. Alkalinity release in fall was entirely driven by metabolic carbonate dissolution, while this process explained between 22 and 69% of total alkalinity production in summer, indicating the importance of other processes in this season. By enhancing organic matter remineralization and the reoxidation of reduced metabolites by the sediment microbial community, lugworm activity stimulated the production of dissolved inorganic carbon and metabolic acidity, which in turn enhanced metabolic CaCO 3 dissolution efficiency. In summer, evidence of microbial long distance electron transport (LDET) was observed in defaunated sediment. Thus, alkalinity production by net carbonate dissolution was likely supplemented by anaerobic respiration and LDET in summer.

[Incidence of proximal femur fractures in relation to seasons of the year and weather].

PubMed

Burget, F; Pleva, L; Kudrna, K; Kudrnová, Z

2012-01-01

The opinion that proximal femur fractures occur mainly in the winter season and are related to slippery surfaces prevails in both the lay and medical communities. The elucidation of this relationship would lead to a better understanding of the aetiology of these fractures and may help to prevent them in the elderly population. In a retrospective study conducted at two departments, the occurrence of proximal femur fractures in patients 60+ years old in relation to weather conditions (air temperature and its humidity, atmospheric pressure, rain and mist) between January 1, 2001 and December 31, 2005 was investigated. Patients with high-energy or pathological fractures were excluded. The results were evaluated by Statistika software. A total of 1720 patients were studied, of whom 1313 were women and 407 were men. The numbers of fractures did not differ significantly among either the seasons or months of the year. No correlation was found between the number of fractures and each of the weather characteristics (air temperature and its humidity, atmospheric pressure, wind speed and visibility). It is widely believed that hip fractures are connected with winter months and temperatures below zero. This is supported by several facts related to winter characteristics, such as slippery icy pavements, clumsiness due to warm bulky clothes, bodies affected by cold and thus predisposed to a fall and poorer visibility on shorter winter days. The effect of seasonal variation on hip fracture incidence has been investigated in 10 studies of which only one has taken the influence of daily temperature into consideration. All studies were conduced in the countries north of 40° latitude, i.e., in climatic conditions similar to our country, with temperatures falling below zero and ice-glazed pavements in winter months. Of them, six have found no relation between proximal femur fractures and weather conditions, two have reported an increased incidence of these fractures in winter months and two in summer months. Our study did not show any significant relationship between the incidence of proximal femur fractures and weather characteristics. Seasons of the year had no effect on the number of hip fractures or the length of hospital stay due to their treatment.

Diving through the thermal window: implications for a warming world

PubMed Central

Campbell, Hamish A.; Dwyer, Ross G.; Gordos, Matthew; Franklin, Craig E.

2010-01-01

Population decline and a shift in the geographical distribution of some ectothermic animals have been attributed to climatic warming. Here, we show that rises in water temperature of a few degrees, while within the thermal window for locomotor performance, may be detrimental to diving behaviour in air-breathing ectotherms (turtles, crocodilians, marine iguanas, amphibians, snakes and lizards). Submergence times and internal and external body temperature were remotely recorded from freshwater crocodiles (Crocodylus johnstoni) while they free-ranged throughout their natural habitat in summer and winter. During summer, the crocodiles' mean body temperature was 5.2 ± 0.1°C higher than in winter and the largest proportion of total dive time was composed of dive durations approximately 15 min less than in winter. Diving beyond 40 min during summer required the crocodiles to exponentially increase the time they spent on the surface after the dive, presumably to clear anaerobic debt. The relationship was not as significant in winter, even though a greater proportion of dives were of a longer duration, suggesting that diving lactate threshold (DLT) was reduced in summer compared with winter. Additional evidence for a reduced DLT in summer was derived from the stronger influence body mass exerted upon dive duration, compared to winter. The results demonstrate that the higher summer body temperature increased oxygen demand during the dive, implying that thermal acclimatization of the diving metabolic rate was inadequate. If the study findings are common among air-breathing diving ectotherms, then long-term warming of the aquatic environment may be detrimental to behavioural function and survivorship. PMID:20610433

Evaluation of Drinks Contribution to Energy Intake in Summer and Winter

PubMed Central

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

2015-01-01

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 < 0.001) and in men higher than in women in both seasons (p < 0.001 in summer, p = 0.02 in winter). Coffee, coffee 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. PMID:25988765

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

PubMed

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 < 0.001) and in men higher than in women in both seasons (p < 0.001 in summer, p = 0.02 in winter). Coffee, coffee 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.

Seasonal perspective of dietary arsenic consumption and urine arsenic in an endemic population.

PubMed

Biswas, Anirban; Deb, Debasree; Ghose, Aloke; Santra, Subhas Chandra; Guha Mazumder, Debendra Nath

2014-07-01

Exposure to arsenic in arsenic endemic areas is most remarkable environmental health challenges. Although effects of arsenic contamination are well established, reports are unavailable on probable seasonal variation due to changes of food habit depending on winter and summer seasons, especially for endemic regions of Nadia district, West Bengal. Complete 24-h diets, drinking-cooking water, first morning voided urine samples, and diet history were analyzed on 25 volunteers in arsenic endemic Chakdah block of Nadia district, once in summer followed by once in winter from the same participants. Results depicted no seasonal variation of body weight and body mass index. Arsenic concentration of source drinking and cooking water decreased (p = 0.04) from 26 μg L(-1) in summer to 6 μg L(-1) in winter season. We recorded a seasonal decrease of water intake in male (3.8 and 2.5 L day (-1)) and female (2.6 and 1.2 L day(-1)) participants from summer to winter. Arsenic intake through drinking water decreased (p = 0.04) in winter (29 μg day(-1)) than in summer (100 μg day(-1)), and urinary arsenic concentration decreased (p = 0.018) in winter (41 μg L(-1)) than in summer (69 μg L(-1)). Dietary arsenic intake remained unchanged (p = 0.24) over the seasons. Hence, we can infer that human health risk assessment from arsenic needs an insight over temporal scale.

Lightning Evolution In Two North Central Florida Summer Multicell Storms and Three Winter/Spring Frontal Storms

NASA Astrophysics Data System (ADS)

Caicedo, J. A.; Uman, M. A.; Pilkey, J. T.

2018-01-01

We present the first lightning evolution studies, via the Lightning Mapping Array (LMA) and radar, performed in North Central Florida. Parts of three winter/spring frontal storms (cold season) and two complete summer (warm season) multicell storms are studied. Storm parameters measured are as follows: total number of flashes, flash-type classification, first flashes, flash initiation altitude, flash initiation power, flash rate (flashes per minute), charge structure, altitude and temperature ranges of the inferred charge regions, atmospheric isotherm altitude, radar base reflectivity (dBZ), and radar echo tops (EET). Several differences were found between summer multicell and winter/spring frontal storms in North Central Florida: (1) in winter/spring storms, the range of altitudes that all charge regions occupy is up to 1 km lower in altitude than in summer storms, as are the 0°C, -10°C, and -20°C isotherms; (2) lightning activity in summer storms is highly correlated with changes in radar signatures, in particular, echo tops; and (3) the LMA average initiation power of all flash types in winter/frontal storms is about an order of magnitude larger than that for summer storms. In relation to storms in other geographical locations, North Central Florida seasonal storms were found to have similarities in most parameters studied with a few differences, examples in Florida being (1) colder initiation altitudes for intracloud flashes, (2) charge regions occupying larger ranges of atmospheric temperatures, and (3) winter/spring frontal storms not having much lightning activity in the stratiform region.

Global climate anomalies and potential infectious disease risks: 2014-2015.

PubMed

Chretien, Jean-Paul; Anyamba, Assaf; Small, Jennifer; Britch, Seth; Sanchez, Jose L; Halbach, Alaina C; Tucker, Compton; Linthicum, Kenneth J

2015-01-26

The El Niño/Southern Oscillation (ENSO) is a global climate phenomenon that impacts human infectious disease risk worldwide through droughts, floods, and other climate extremes. Throughout summer and fall 2014 and winter 2015, El Niño Watch, issued by the US National Oceanic and Atmospheric Administration, assessed likely El Niño development during the Northern Hemisphere fall and winter, persisting into spring 2015. We identified geographic regions where environmental conditions may increase infectious disease transmission if the predicted El Niño occurs using El Niño indicators (Sea Surface Temperature [SST], Outgoing Longwave Radiation [OLR], and rainfall anomalies) and literature review of El Niño-infectious disease associations. SSTs in the equatorial Pacific and western Indian Oceans were anomalously elevated during August-October 2014, consistent with a developing weak El Niño event. Teleconnections with local climate is evident in global precipitation patterns, with positive OLR anomalies (drier than average conditions) across Indonesia and coastal southeast Asia, and negative anomalies across northern China, the western Indian Ocean, central Asia, north-central and northeast Africa, Mexico/Central America, the southwestern United States, and the northeastern and southwestern tropical Pacific. Persistence of these conditions could produce environmental settings conducive to increased transmission of cholera, dengue, malaria, Rift Valley fever, and other infectious diseases in regional hotspots as during previous El Niño events. The current development of weak El Niño conditions may have significant potential implications for global public health in winter 2014-spring 2015. Enhanced surveillance and other preparedness measures in predicted infectious disease hotspots could mitigate health impacts.

A possible cause of the AO polarity reversal from winter to summer in 2010 and its relation to hemispheric extreme summer weather

NASA Astrophysics Data System (ADS)

Otomi, Yuriko; Tachibana, Yoshihiro; Nakamura, Tetsu

2013-04-01

In 2010, the Northern Hemisphere, in particular Russia and Japan, experienced an abnormally hot summer characterized by record-breaking warm temperatures and associated with a strongly positive Arctic Oscillation (AO), that is, low pressure in the Arctic and high pressure in the midlatitudes. In contrast, the AO index the previous winter and spring (2009/2010) was record-breaking negative. The AO polarity reversal that began in summer 2010 can explain the abnormally hot summer. The winter sea surface temperatures (SST) in the North Atlantic Ocean showed a tripolar anomaly pattern—warm SST anomalies over the tropics and high latitudes and cold SST anomalies over the midlatitudes—under the influence of the negative AO. The warm SST anomalies continued into summer 2010 because of the large oceanic heat capacity. A model simulation strongly suggested that the AO-related summertime North Atlantic oceanic warm temperature anomalies remotely caused blocking highs to form over Europe, which amplified the positive summertime AO. Thus, a possible cause of the AO polarity reversal might be the "memory" of the negative winter AO in the North Atlantic Ocean, suggesting an interseasonal linkage of the AO in which the oceanic memory of a wintertime negative AO induces a positive AO in the following summer. Understanding of this interseasonal linkage may aid in the long-term prediction of such abnormal summer events.

A possible cause of the AO polarity reversal from winter to summer in 2010 and its relation to hemispheric extreme hot summer

NASA Astrophysics Data System (ADS)

Tachibana, Yoshihiro; Otomi, Yuriko; Nakamura, Tetsu

2013-04-01

In 2010, the Northern Hemisphere, in particular Russia and Japan, experienced an abnormally hot summer characterized by record-breaking warm temperatures and associated with a strongly positive Arctic Oscillation (AO), that is, low pressure in the Arctic and high pressure in the midlatitudes. In contrast, the AO index the previous winter and spring (2009/2010) was record-breaking negative. The AO polarity reversal that began in summer 2010 can explain the abnormally hot summer. The winter sea surface temperatures (SST) in the North Atlantic Ocean showed a tripolar anomaly pattern—warm SST anomalies over the tropics and high latitudes and cold SST anomalies over the midlatitudes—under the influence of the negative AO. The warm SST anomalies continued into summer 2010 because of the large oceanic heat capacity. A model simulation strongly suggested that the AO-related summertime North Atlantic oceanic warm temperature anomalies remotely caused blocking highs to form over Europe, which amplified the positive summertime AO. Thus, a possible cause of the AO polarity reversal might be the "memory" of the negative winter AO in the North Atlantic Ocean, suggesting an interseasonal linkage of the AO in which the oceanic memory of a wintertime negative AO induces a positive AO in the following summer. Understanding of this interseasonal linkage may aid in the long-term prediction of such abnormal summer events.

Summer Setback: Race, Poverty, School Composition, and Mathematics Achievement in the First Two Years of School.

ERIC Educational Resources Information Center

Entwisle, Doris R.; Alexander, Karl L.

1992-01-01

Data for 542, 490, 464, and 430 Baltimore (Maryland) children in winter 1982-83, summer 1983, winter 1983-84, and summer 1984, respectively, show about equal mathematics achievement of African Americans and whites at the start of grade 1, but African Americans were behind about 0.5 standard deviation by grade 3. (SLD)

Utility of seasonal climate forecasts in management of winter-wheat grazing

USDA-ARS?s Scientific Manuscript database

Winter wheat in the southern Great Plains is a dual crop that produces livestock forage in the fall and winter and a grain crop in the spring. Forage production is highly dependent upon climatic variability, but stocking rate purchasing decisions must generally be made shortly after the fall planti...

Ecological role of reindeer summer browsing in the mountain birch (Betula pubescens ssp. czerepanovii) forests: effects on plant defense, litter decomposition, and soil nutrient cycling.

PubMed

Stark, Sari; Julkunen-Tiitto, Riitta; Kumpula, Jouko

2007-03-01

Mammalian herbivores commonly alter the concentrations of secondary compounds in plants and, by this mechanism, have indirect effects on litter decomposition and soil carbon and nutrient cycling. In northernmost Fennoscandia, the subarctic mountain birch (Betula pubescens ssp. czerepanovii) forests are important pasture for the semidomestic reindeer (Rangifer tarandus). In the summer ranges, mountain birches are intensively browsed, whereas in the winter ranges, reindeer feed on ground lichens, and the mountain birches remain intact. We analyzed the effect of summer browsing on the concentrations of secondary substances, litter decomposition, and soil nutrient pools in areas that had been separated as summer or winter ranges for at least 20 years, and we predicted that summer browsing may reduce levels of secondary compounds in the mountain birch and, by this mechanism, have an indirect effect on the decomposition of mountain birch leaf litter and soil nutrient cycling. The effect of browsing on the concentration of secondary substances in the mountain birch leaves varied between different years and management districts, but in some cases, the concentration of condensed tannins was lower in the summer than in the winter ranges. In a reciprocal litter decomposition trial, both litter origin and emplacement significantly affected the litter decomposition rate. Decomposition rates were faster for the litter originating from and placed into the summer range. Soil inorganic nitrogen (N) concentrations were higher in the summer than in the winter ranges, which indicates that reindeer summer browsing may enhance the soil nutrient cycling. There was a tight inverse relationship between soil N and foliar tannin concentrations in the winter range but not in the summer range. This suggests that in these strongly nutrient-limited ecosystems, soil N availability regulates the patterns of resource allocation to condensed tannins in the absence but not in the presence of browsing.

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

PubMed

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.

Exposure to radon in the Gadime Cave, Kosovo.

PubMed

Bahtijari, M; Vaupotic, J; Gregoric, A; Stegnar, P; Kobal, I

2008-02-01

Air radon concentration was measured in summer and winter at 11 points along the tourist guided route in the Gadime Cave in Kosovo using alpha scintillation cells and etched track detectors. At two points in summer, values higher than 1700Bqm(-3) were observed; they otherwise were in the range 400-1000Bqm(-3). Values were lower in winter. The effective dose received by a person during a 90min visit is 3.7microSv in summer and 2.5microSv in winter. For a tourist guide the annual effective dose is less than 3.5mSv.

Long-term dynamics of winter and summer annual communities in the Chihuahuan Desert

USGS Publications Warehouse

Guo, Q.; Brown, J.H.; Valone, T.J.

2002-01-01

Using 15 years of census data from permanent quadrats, this paper compared the characteristics and temporal dynamics of these two distinct, spatially coexistent but temporally segregated communities. Although the total number of summer annual species recorded during our 15 years observation was higher than winter annuals, the average number of species observed each year was higher in the winter community. The winter community exhibited lower temporal variation in total plant abundance and populations of individual species, lower species turnover rate and higher evenness than the summer community. The higher seasonal species diversity (i.e., number of species observed in each season) in winters rather than the overall special pool (over 15 yrs) may be responsible for the greater community stability of winter annuals. The difference in long-term community dynamics between the two communities of annuals plants are likely due to the differences in total species pool, life history traits (e.g., seed size), and seasonal climatic regimes.

Retrospective Surveillance of Wastewater To Examine Seasonal Dynamics of Enterovirus Infections

PubMed Central

Fout, G. Shay; Keely, Scott P.

2017-01-01

ABSTRACT Enteroviruses are RNA viruses that are responsible for both mild gastroenteritis and mild respiratory illnesses as well as debilitating diseases such as meningitis and myocarditis. The disease burden of enteroviruses in the United States is difficult to assess because most infections are not recorded. Since infected individuals shed enterovirus in feces and urine, surveillance of municipal wastewater can reveal the diversity of enteroviruses circulating in human populations. Therefore, monthly municipal wastewater samples were collected for 1 year and enteroviruses were quantified by reverse transcriptase quantitative PCR and identified by next-generation, high-throughput sequencing. Enterovirus concentrations ranged from 3.8 to 5.9 log10 equivalent copies/liter in monthly samples. From the mean monthly concentration, it can be estimated that 2.8% of the contributing population was shedding enterovirus daily. Sequence analysis showed that Enterovirus A and Enterovirus B alternate in predominance, with Enterovirus B comprising over 80% of the reads during the summer and fall months and Enterovirus A accounting for >45% of the reads in spring. Enterovirus C was observed throughout the year, while Enterovirus D was present intermittently. Principal-component analysis further supported the date corresponding to enterovirus seasonal trends as CVA6 (Enterovirus A) was predominant in the spring months; CVB3, CVB5, and E9 (Enterovirus B) were predominant in the summer and fall months; and CVA1, CVA19, and CVA22 (Enterovirus C) and EV97 (Enterovirus B) were predominant in winter. Rhinoviruses were also observed. Wastewater monitoring of human enterovirus provided improved insight into the seasonal patterns of enteroviruses circulating in communities and can contribute to understanding of enterovirus disease burden. IMPORTANCE Enterovirus infections are often not tracked or reported to health officials. This makes it hard to know how many people in a community are infected with these viruses at any given time. Here, we explored enterovirus in municipal wastewater to look at this issue. We show that enteroviruses are present year-round in municipal wastewater at levels of up to 800,000 genomic copies per liter. We estimate that, on average, 2.8% of the people contributing to the wastewater shed enterovirus daily. Sequence analysis of the viral capsid protein 4 gene shows that 8 enterovirus types are key drivers of seasonal trends. Populations of Enterovirus A members peak in the spring, while Enterovirus B types are most prevalent during the summer and fall months and Enterovirus C members influence the winter months. Enterovirus D was observed sporadically and did not influence seasonal trends. PMID:28630939

Relations between winter climatic variables and April streamflows in New England and implications for summer streamflows

USGS Publications Warehouse

Hodgkins, Glenn A.; Dudley, Robert W.; Schalk, Luther F.

2012-01-01

A period of much below normal streamflow in southern New England during April 2012 raised concerns that a long-term period of drought could evolve through late spring and summer, leading to potential water availability issues. To understand better the relations between winter climatic variables and April streamflows, April streamflows from 31 streamflow gages in New England that drain relatively natural watersheds were tested for year-to-year correlation with winter precipitation and air temperature from nearby meteorological sites. Higher winter (December through March) precipitation is associated with higher April streamflows at many gages in northern and central New England. This implies that snowpack accumulation is an important mechanism for winter water storage and subsequently important for spring streamflows in this area. Higher March air temperatures are associated with lower April streamflows at many gages in central and southern New England, likely because the majority of snowmelt runoff occurs before April in warm years. A warm March 2012 contributed to early snowmelt runoff in New England and to much below normal April streamflows in southern New England. However, no strong relation was found between historical April streamflows and late-spring or summer streamflows in New England. The lack of a strong relation implies that summer precipitation, rather than spring conditions, controls summer streamflows.

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

NASA Technical Reports Server (NTRS)

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.

Seasonal dependence of large-scale Birkeland currents

NASA Technical Reports Server (NTRS)

Fujii, R.; Iijima, T.; Potemra, T. A.; Sugiura, M.

1981-01-01

Seasonal variations of large-scale Birkeland currents are examined in a study of the source mechanisms and the closure of the three-dimensional current systems in the ionosphere. Vector magnetic field data acquired by the TRIAD satellite in the Northern Hemisphere were analyzed for the statistics of single sheet and double sheet Birkeland currents during 555 passes during the summer and 408 passes during the winter. The single sheet currents are observed more frequently in the dayside of the auroral zone, and more often in summer than in winter. The intensities of both the single and double dayside currents are found to be greater in the summer than in the winter by a factor of two, while the intensities of the double sheet Birkeland currents on the nightside do not show a significant difference from summer to winter. Both the single and double sheet currents are found at higher latitudes in the summer than in the winter on the dayside. Results suggest that the Birkeland current intensities are controlled by the ionospheric conductivity in the polar region, and that the currents close via the polar cap when the conductivity there is sufficiently high. It is also concluded that an important source of these currents must be a voltage generator in the magnetosphere.

Arctic multiyear ice classification and summer ice cover using passive microwave satellite data

NASA Technical Reports Server (NTRS)

Comiso, J. C.

1990-01-01

Passive microwave data collected by Nimbus 7 were used to classify and monitor the Arctic multilayer sea ice cover. Sea ice concentration maps during several summer minima are analyzed to obtain estimates of ice floes that survived summer, and the results are compared with multiyear-ice concentrations derived from these data by using an algorithm that assumes a certain emissivity for multiyear ice. The multiyear ice cover inferred from the winter data was found to be about 25 to 40 percent less than the summer ice-cover minimum, indicating that the multiyear ice cover in winter is inadequately represented by the passive microwave winter data and that a significant fraction of the Arctic multiyear ice floes exhibits a first-year ice signature.

Stable isotope compositions of waters in the Great Basin, United States 3. Comparison of groundwaters with modern precipitation

USGS Publications Warehouse

Smith, G.I.; Friedman, I.; Veronda, G.; Johnson, C.A.

2002-01-01

Groundwater samples from wells and springs, scattered over most of the Great Basin province, were collected and analyzed for their isotopic makeup. They were augmented by previously published isotopic data on groundwaters from southeast California and by several hundred unpublished isotopic analyses. The ratio of 2H (deuterium, D) to 1H, in water samples from valleys in parts of California, Idaho, Nevada, Oregon, and Utah, are here compared with the winter, summer, and annual isotopic compositions of precipitation falling in or near the sampled areas. The main goal of this study was to identify basins where the groundwaters have isotopic compositions that are "lighter" (depleted in the heavier isotope, D) relative to modern winter precipitation. Where these basins do not adjoin substantially higher terrain, we consider those light groundwaters to be of Pleistocene age and thus more than 10,000 years old. Where the groundwater is 10 to 19??? lighter than local winter precipitation, we consider it to be possibly an indication of Pleistocene water; where the ??D makeup is >20??? lighter, we consider it to be probably Pleistocene water. More than 80 sites underlain by waters of possible or probable Pleistocene age were identified.

The annual planktonic protist community structure in an ice-free high Arctic fjord (Adventfjorden, West Spitsbergen)

NASA Astrophysics Data System (ADS)

Kubiszyn, A. M.; Wiktor, J. M.; Wiktor, J. M.; Griffiths, C.; Kristiansen, S.; Gabrielsen, T. M.

2017-05-01

We investigated the size and trophic structure of the annual planktonic protist community structure in the ice-free Adventfjorden in relation to environmental factors. Our high-resolution (weekly to monthly) study was conducted in 2012, when warm Atlantic water was advected into the fjord in winter and summer. We observed a distinct seasonality in the protist communities. The winter protist community was characterised by extremely low levels of protist abundance and biomass (primarily Dinophyceae, Ciliophora and Bacillariophyceae) in a homogenous water column. In the second half of April, the total protist abundance and biomass rapidly increased, thus initiating the spring bloom in a still well-mixed water column. The spring bloom was initially dominated by the prymnesiophyte Phaeocystis pouchetii and Bacillariophyceae (primarily from the genera Thalassiosira, Fragilariopsis and Chaetoceros) and was later strictly dominated by Phaeocystis colonies. When the bloom terminated in mid-June, the community shifted towards flagellates (Dinophyceae, Ciliophora, Cryptophyceae and nanoflagellates 3-7 μm in size) in a stratified, nutrient-depleted water column. Decreases in the light intensity decreased the protist abundance and biomass, and the fall community (Dinophyceae, Cryptophyceae and Bacillariophyceae) was followed by the winter community.

Thermal Acclimatization in Overwintering Tadpoles of the Green Frog, Lithobates clamitans (Latreille, 1801).

PubMed

Gray, Kathryn T; Escobar, Astrid M; Schaeffer, Paul J; Mineo, Patrick M; Berner, Nancy J

2016-06-01

Seasonal acclimatization permits organisms to maintain function in the face of environmental change. Tadpoles of the green frog (Lithobates clamitans) overwinter as tadpoles in much of their range. Because they are active in winter, we hypothesized that green frog tadpoles would display acclimatization of metabolic and locomotor function. We collected tadpoles in Sewanee, Tennessee (35.2°N) in winter and summer. Tadpoles collected during each season were tested at both winter (8°C) and summer (26°C) temperatures. Winter tadpoles were able to maintain swimming performance at both temperatures, whereas swimming performance decreased at cold temperatures in summer tadpoles. There was no evidence for seasonal acclimatization of whole-animal metabolic rate. Although whole-animal metabolic acclimatization was not observed, the activities of cytochrome c oxidase, citrate synthase, and lactate dehydrogenase measured in skeletal muscle homogenates showed higher activity in winter-acclimatized tadpoles indicating compensation for temperature. Further, the composition of muscle membranes of winter tadpoles had less saturated and more monounsaturated fatty acids and a higher ω-3 balance, unsaturation index, and peroxidation index than summer tadpoles. These data indicate that reversible phenotypic plasticity of thermal physiology occurs in larval green frog tadpoles. They appear to compensate for colder temperatures to maintain burst-swimming velocity and the ability to escape predators without the cost of maintaining a constant, higher standard metabolic rate in the winter. © 2016 Wiley Periodicals, Inc.

Forage radish winter cover crop suppresses winter annual weeds in fall and before corn planting

USDA-ARS?s Scientific Manuscript database

Forage radish (Raphanus sativus L. var. longipinnatus) is a new winter cover crop in the Mid-Atlantic region. The objective of this project was to characterize the repeatability, amount, and duration of weed suppression during and after a fall-planted forage radish cover crop and to quantify the sub...

Indoor, outdoor, and regional summer and winter concentrations of PM10, PM2.5, SO4(2)-, H+, NH4+, NO3-, NH3, and nitrous acid in homes with and without kerosene space heaters.

PubMed Central

Leaderer, B P; Naeher, L; Jankun, T; Balenger, K; Holford, T R; Toth, C; Sullivan, J; Wolfson, J M; Koutrakis, P

1999-01-01

Twenty-four-hour samples of PM10 (mass of particles with aerodynamic diameter < or = 10 microm), PM2.5, (mass of particles with aerodynamic diameter < or = 2.5 microm), particle strong acidity (H+), sulfate (SO42-), nitrate (NO3-), ammonia (NH3), nitrous acid (HONO), and sulfur dioxide were collected inside and outside of 281 homes during winter and summer periods. Measurements were also conducted during summer periods at a regional site. A total of 58 homes of nonsmokers were sampled during the summer periods and 223 homes were sampled during the winter periods. Seventy-four of the homes sampled during the winter reported the use of a kerosene heater. All homes sampled in the summer were located in southwest Virginia. All but 20 homes sampled in the winter were also located in southwest Virginia; the remainder of the homes were located in Connecticut. For homes without tobacco combustion, the regional air monitoring site (Vinton, VA) appeared to provide a reasonable estimate of concentrations of PM2.5 and SO42- during summer months outside and inside homes within the region, even when a substantial number of the homes used air conditioning. Average indoor/outdoor ratios for PM2.5 and SO42- during the summer period were 1.03 +/- 0.71 and 0.74 +/- 0.53, respectively. The indoor/outdoor mean ratio for sulfate suggests that on average approximately 75% of the fine aerosol indoors during the summer is associated with outdoor sources. Kerosene heater use during the winter months, in the absence of tobacco combustion, results in substantial increases in indoor concentrations of PM2.5, SO42-, and possibly H+, as compared to homes without kerosene heaters. During their use, we estimated that kerosene heaters added, on average, approximately 40 microg/m3 of PM2.5 and 15 microg/m3 of SO42- to background residential levels of 18 and 2 microg/m3, respectively. Results from using sulfuric acid-doped Teflon (E.I. Du Pont de Nemours & Co., Wilmington, DE) filters in homes with kerosene heaters suggest that acid particle concentrations may be substantially higher than those measured because of acid neutralization by ammonia. During the summer and winter periods indoor concentrations of ammonia are an order of magnitude higher indoors than outdoors and appear to result in lower indoor acid particle concentrations. Nitrous acid levels are higher indoors than outdoors during both winter and summer and are substantially higher in homes with unvented combustion sources. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10064553

Multidecadal increases in the Yukon River Basin of chemical fluxes as indicators of changing flowpaths, groundwater, and permafrost

USGS Publications Warehouse

Toohey, Ryan C; Herman-Mercer, Nicole M.; Schuster, Paul F.; Mutter, Edda A.; Koch, Joshua C.

2016-01-01

The Yukon River Basin, underlain by discontinuous permafrost, has experienced a warming climate over the last century that has altered air temperature, precipitation, and permafrost. We investigated a water chemistry database from 1982 to 2014 for the Yukon River and its major tributary, the Tanana River. Significant increases of Ca, Mg, and Na annual flux were found in both rivers. Additionally, SO4 and P annual flux increased in the Yukon River. No annual trends were observed for dissolved organic carbon (DOC) from 2001 to 2014. In the Yukon River, Mg and SO4 flux increased throughout the year, while some of the most positive trends for Ca, Mg, Na, SO4, and P flux occurred during the fall and winter months. Both rivers exhibited positive monthly DOC flux trends for summer (Yukon River) and winter (Tanana River). These trends suggest increased active layer expansion, weathering, and sulfide oxidation due to permafrost degradation throughout the Yukon River Basin.

Autotrophic processes in meromictic Big Soda Lake, Nevada.

USGS Publications Warehouse

Cloern, J.E.; Cole, B.E.; Oremland, R.S.

1983-01-01

Daily rates of oxygenic photosynthesis (OP) by phytoplankton, anoxygenic photosynthesis (AP) by purple sulfur bacteria, and chemoautotrophic productivity (CP = dark CO2 assimilation) were measured once each season. Total daily productivity and the relative importance of each autotrophic process varied with seasonal changes in vertical mixing, light availability, and the biomass of phototrophs. Daily productivity was highest (2830 mg C.m-2) and was dominated by OP in winter when the mixolimnion was isothermal, the biomass of phytoplankton was high, and the biomass of purple sulfur bacteria was low. During the summer-fall period of thermal stratification, phytoplankton biomass decreased, a plate of purple sulfur bacteria formed below the oxycline, and daily rates of dark CO2 assimilation (CP = 390-680 mg C.m-2) exceeded phototrophic productivity (OP + AP = 200-370 mg C.m-2). Total annual productivity was approx 500 g C.m-2, of which 60% was produced by phytoplankton (mostly in winter), 30% by chemoautotrophs (nitrifying and sulfur-oxidizing bacteria), and only 10% by photosynthetic bacteria. -Authors

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

PubMed

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 HSAo defined as regular, non-winter sport areas do not show such seasonality. We conclude that leisure sport, and especially ski/snowboard tourism demands great flexibility in hospital beds, staff and resource planning in these areas.

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

PubMed Central

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

2006-01-01

Background 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. Methods 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. Results 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. Conclusion 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 HSAo defined as regular, non-winter sport areas do not show such seasonality. We conclude that leisure sport, and especially ski/snowboard tourism demands great flexibility in hospital beds, staff and resource planning in these areas. PMID:16512923

50 CFR Table 3 to Part 226 - Hydrologic Units Containing Critical Habitat for Snake River Sockeye Salmon and Snake River...

Code of Federal Regulations, 2014 CFR

2014-10-01

... Habitat for Snake River Sockeye Salmon and Snake River Spring/Summer and Fall Chinook Salmon 3 Table 3 to... Spring/Summer and Fall Chinook Salmon Hydrologic unit name Hydrologic unit number Sockeye salmon Spring/summer chinook salmon Fall chinook salmon Hells Canyon 17060101 17060101 Imnaha 17060102 17060102 Lower...

50 CFR Table 3 to Part 226 - Hydrologic Units Containing Critical Habitat for Snake River Sockeye Salmon and Snake River...

Code of Federal Regulations, 2013 CFR

2013-10-01

... Habitat for Snake River Sockeye Salmon and Snake River Spring/Summer and Fall Chinook Salmon 3 Table 3 to... Spring/Summer and Fall Chinook Salmon Hydrologic unit name Hydrologic unit number Sockeye salmon Spring/summer chinook salmon Fall chinook salmon Hells Canyon 17060101 17060101 Imnaha 17060102 17060102 Lower...

50 CFR Table 3 to Part 226 - Hydrologic Units Containing Critical Habitat for Snake River Sockeye Salmon and Snake River...

Code of Federal Regulations, 2012 CFR

2012-10-01

... Habitat for Snake River Sockeye Salmon and Snake River Spring/Summer and Fall Chinook Salmon 3 Table 3 to... Spring/Summer and Fall Chinook Salmon Hydrologic unit name Hydrologic unit number Sockeye salmon Spring/summer chinook salmon Fall chinook salmon Hells Canyon 17060101 17060101 Imnaha 17060102 17060102 Lower...

The Effect of the Ionosphere on Radiowave Signals and Systems Performance Based on Ionospheric Effects Symposium Held on 1-3 May 1990

DTIC Science & Technology

1990-05-03

winter and a minimum in summer ; in contrast, at sunspot maximum the seasonal peaks tend to occur around the equinoxes and the minima in summer . ’riis is...more clearly seen in Figures 4(b) ahnd 4(c). Note that around sunspot maximum the summer noon value may be less than the summer midnight value. (3) The...seasonal variation of the midnight values show summer peaks and winter minima with high values near the peaks of the sunspot cycles and low values

Seasonal variation in the range areas of the diurnal rodent Octodon degus

PubMed Central

Quirici, Verónica; Castro, Rodrigo A.; Ortiz-Tolhuysen, Liliana; Chesh, Adrian S.; Burger, Joseph Robert; Miranda, Eduardo; Cortés, Arturo; Hayes, Loren D.; Ebensperger, Luis A.

2012-01-01

Both breeding activity and abundance and quality of available food are expected to influence daily movements of animals. Animals are predicted to range over large areas to meet high energy demands associated with reproduction (females) or to increase mating success (males). However, animals should expand their range areas whenever food conditions deteriorate. To examine the extent to which breeding activity versus food availability influence space use, we compared the size and location of range areas (home ranges) of the degu (Octodon degus), a diurnal rodent from semiarid environments of north-central Chile, during the austral winter and summer seasons. Degus produce young during the austral spring (September–October) when high-quality food is readily available. In contrast, degus do not breed during the austral summer (January–March) when food is scarce and of low quality. We predicted that degus would range over smaller areas in winter if the availability of food has a greater influence on space than breeding activity. Individuals were radiotracked in winter and the following summer over a 3-year period. Surveys of herbaceous cover were conducted during winter and summer to determine seasonal changes in the abundance and quality of primary food. In summer degus expanded and moved the location of their range areas to locations with available food. Given that preferred food was less abundant in summer than winter, we suggest that degu range areas are strongly influenced by food conditions. PMID:22328788

Physical and chemical characteristics of PM2.5 and its toxicity to human bronchial cells BEAS-2B in the winter and summer.

PubMed

Zhang, Hui-Hui; Li, Zheng; Liu, Yu; Xinag, Ping; Cui, Xin-Yi; Ye, Hui; Hu, Bao-Lan; Lou, Li-Ping

With the increasing occurrence of haze during the summer, the physicochemical characteristics and toxicity differences in PM 2.5 in different seasons are of great concern. Hangzhou is located in an area that has a subtropical monsoon climate where the humidity is very high during both the summer and winter. However, there are limited studies on the seasonal differences in PM 2.5 in these weather conditions. In this test, PM 2.5 samples were collected in the winter and summer, the morphology and chemical composition of PM 2.5 were analyzed, the toxicity of PM 2.5 to human bronchial cells BEAS-2B was compared, and the correlation between PM 2.5 toxicity and the chemical composition was discussed. The results showed that during both the winter and summer, the main compounds in the PM 2.5 samples were water-soluble ions, particularly SO 4 2- , NO 3 - , and NH 4 + , followed by organic components, while heavy metals were present at lower levels. The higher the mass concentration of PM 2.5 , the greater its impact on cell viability and ROS levels. However, when the mass concentration of PM 2.5 was similar, the water extraction from the summer samples showed a greater impact on BEAS-2B than that from the winter samples. The cytotoxicity of PM 2.5 was closely associated with heavy metals and organic pollutants but less related to water-soluble ions.

Seasonal variation in the range areas of the diurnal rodent Octodon degus.

PubMed

Quirici, Verónica; Castro, Rodrigo A; Ortiz-Tolhuysen, Liliana; Chesh, Adrian S; Burger, Joseph Robert; Miranda, Eduardo; Cortés, Arturo; Hayes, Loren D; Ebensperger, Luis A

2010-01-01

Both breeding activity and abundance and quality of available food are expected to influence daily movements of animals. Animals are predicted to range over large areas to meet high energy demands associated with reproduction (females) or to increase mating success (males). However, animals should expand their range areas whenever food conditions deteriorate. To examine the extent to which breeding activity versus food availability influence space use, we compared the size and location of range areas (home ranges) of the degu (Octodon degus), a diurnal rodent from semiarid environments of north-central Chile, during the austral winter and summer seasons. Degus produce young during the austral spring (September-October) when high-quality food is readily available. In contrast, degus do not breed during the austral summer (January-March) when food is scarce and of low quality. We predicted that degus would range over smaller areas in winter if the availability of food has a greater influence on space than breeding activity. Individuals were radiotracked in winter and the following summer over a 3-year period. Surveys of herbaceous cover were conducted during winter and summer to determine seasonal changes in the abundance and quality of primary food. In summer degus expanded and moved the location of their range areas to locations with available food. Given that preferred food was less abundant in summer than winter, we suggest that degu range areas are strongly influenced by food conditions.

Exposure to UV filters during summer and winter in Danish kindergarten children.

PubMed

Krause, Marianna; Andersson, Anna-Maria; Skakkebaek, Niels E; Frederiksen, Hanne

2017-02-01

Ultra violet (UV) filters with known or suspected endocrine disrupting properties are widely used in sunscreens and other personal care products, clothing, food packaging and many other consumer products. Danish kindergarten children have sunscreens applied daily during summer to prevent skin burns. To estimate the assumed contribution of sunscreens to the total exposure to UV filters, we measured the urinary excretion of UV filters during summer and winter in kindergarten children. Spot- and first morning urines were collected during a summer and a winter day in 2013. A total of 266 urine samples were collected from 55 children and were analysed for content of benzophenone (BP), benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), 5-chloro-2-hydroxybenzophenone (BP-7), 4-methyl-benzophenone (4-MBP), 4-hydroxybenzophenone (4-HBP), 3-(4-methylbenzylidene)-camphor (4-MBC), and 3-benzylidene camphor (3-BC) by LC-MS/MS. Of the analysed UV filters, the children excreted predominantly BP-1, BP-3 and 4-HBP. The urine levels were significantly higher in summer samples compared to winter samples, however exposure during winter was still evident. Furthermore, children with the highest concentrations of UV filters in summer urines also tended to be among those with the highest winter levels. Exposures to UV filters during summertime can partly be explained by the intended use of UV filters in sunscreens, which is considered to be beneficial for children during outdoor activities. However, exposure to UV filters all year round together with large inter-individual variation indicate that children's exposure to UV filters also comes from other consumer items, presumably highly influenced by the general lifestyle of an individual child: this is completely unintended, without benefit, and potentially harmful. Copyright © 2016 Elsevier Ltd. All rights reserved.

Validation of summer and winter ELISA measurements of serum 25-hydroxyvitamin D concentrations in Mongolia.

PubMed

Bromage, Sabri; Tselmen, Daria; Bradwin, Gary; Holick, Michael F; Ganmaa, Davaasaambuu

2017-01-01

Assay cost, quality, and availability pose challenges for vitamin D surveys in limited resource settings. This study aimed to validate an inexpensive vitamin D assay (ELISA) under real-world conditions in Mongolia, the northernmost developing country, to characterize the assay's usefulness and inform the design of epidemiologic studies in similar regions. We collected paired summer and winter serum samples from 120 men and women (aged 20-57 years) in urban and rural Mongolia, analyzed each sample for 25(OH)D concentration using both Immunodiagnostic Systems ELISA and DiaSorin LIAISON 25(OH)D TOTAL, and compared the assays using multiple statistics. LIAISON was itself validated by participation in the DEQAS program. Correlation and agreement between assays were higher in summer (Pearson's correlation=0.60, Spearman's rank correlation=0.67, Lin's concordance correlation=0.56) than winter (rP=0.37, rS=0.43, rC=0.33), although ELISA less accurately assigned subjects to sufficiency categories in summer (percent agreement=44%) than winter (58%), during the latter of which most subjects were deficient ([25(OH)D] categories used: >75 nmol/L (optimal), 50-75 nmol/L (adequate), 25-50 nmol/L (inadequate), <25 nmol/L (deficient)). Compared with LIAISON, ELISA tended to indicate higher vitamin D status in both seasons (mean paired difference: 7.0 nmol/L (95% CI: 3.5-10.5) in summer, 5.2 nmol/L (95% CI: 2.9-7.5) in winter). ELISA proved useful for measuring and ranking subjects' vitamin D status in Mongolia during summer, but levels were too low in winter to sensitively discriminate between subjects, and ELISA overestimated status in both seasons. These findings have implications for the timing and interpretation, respectively, of vitamin D surveys in highly deficient populations.

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

PubMed Central

Aumann, Tim D.; Raabus, Mai; Tomas, Doris; Prijanto, Agustinus; Churilov, Leonid; Spitzer, Nicholas C.; Horne, Malcolm K.

2016-01-01

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. PMID:27428306

Mortality of fish in Lake Erie

USGS Publications Warehouse

Van Oosten, John

1936-01-01

The food habits of Blue Grouse vary from a simple winter diet that is made up predominantly of coniferous needles to a complex diet during the summer months, characterized by great variety of foods including green leaves, fruits and seeds, flowers, animal matter and coniferous needles. The spring and fall, which represent the transition periods between these two, are characterized by feeding habits that are generally intermediate. The diets of the two species of Blue Grouse, Dendrugapus obscurus and Dendragapus juliginosus, are quite similar as far as major types of food are concerned, but they differ considerably in the species that are taken. Such differences reflect differences in the vegetation within the ecologic and geographic ranges occupied by the two species.

Food habits of blue grouse

USGS Publications Warehouse

Stewart, R.E.

1944-01-01

The food habits of Blue Grouse vary from a simple winter diet that is made up predominantly of coniferous needles to a complex diet during the summer months, characterized by great variety of foods including green leaves, fruits and seeds, flowers, animal matter and coniferous needles. The spring and fall, which represent the transition periods between these two, are characterized by feeding habits that are generally intermediate. The diets of the two species of Blue Grouse, Dendrugapus obscurus and Dendragapus juliginosus, are quite similar as far as major types of food are concerned, but they differ considerably in the species that are taken. Such differences reflect differences in the vegetation within the ecologic and geographic ranges occupied by the two species.

Climatological simulations of ozone and atmospheric aerosols in the Greater Cairo region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steiner, A. L.; Tawfik, A. B.; Shalaby, A.

An integrated chemistry-climate model (RegCM4-CHEM) simulates present-day climate, ozone and tropospheric aerosols over Egypt with a focus on Greater Cairo (GC) region. The densley populated GC region is known for its severe air quality issues driven by high levels of anthropogenic pollution in conjuction with natural sources such as dust and agricultural burning events. We find that current global emission inventories underestimate key pollutants such as nitrogen oxides and anthropogenic aerosol species. In the GC region, average-ground-based NO2 observations of 40-60 ppb are substantially higher than modeled estimates (5-10 ppb), likely due to model grid resolution, improper boundary layer representation,more » and poor emissions inventories. Observed ozone concentrations range from 35 ppb (winter) to 80 ppb (summer). The model reproduces the seasonal cycle fairly well, but modeled summer ozone is understimated by approximately 15 ppb and exhibits little interannual variability. For aerosols, springtime dust events dominate the seasonal aerosol cycle. The chemistry-climate model captures the springtime peak aerosol optical depth (AOD) of 0.7-1 but is slightly greater than satellite-derived AOD. Observed AOD decreases in the summer and increases again in the fall due to agricultural burning events in the Nile Delta, yet the model underestimates this fall observed AOD peak, as standard emissions inventories underestimate this burning and the resulting aerosol emissions. Our comparison of modeled gas and particulate phase atmospheric chemistry in the GC region indicates that improved emissions inventories of mobile sources and other anthropogenic activities are needed to improve air quality simulations in this region.« less

Thermal and dissolved oxygen characteristics of a South Carolina cooling reservoir

USGS Publications Warehouse

Oliver, James L.; Hudson, Patrick L.

1987-01-01

Temperature and dissolved oxygen concentrations were measured monthly from January 1971 to December 1982 at 1-m depth intervals at 13 stations in Keowee Reservoir in order to characterize spatial and temporal changes associated with operation of the Oconee Nuclear Station. The reservoir water column was i to 4°C warmer in operational than in non-operational years. The thermo-dine was at depths of 5 to 15 m before the operation of Oconee Nuclear Station, but was always below the upper level of the intake (20 m) after the station was in full operation; this suggests that pumping by the Oconee Nuclear Station had depleted all available cool hypolimnetic water to this depth. As a result summer water temperatures at depths greater than 10 m were usually 10°C higher after plant operation began than before. By fall the reservoir was nearly homothemious to a depth of 27 m, where a thermocine developed. Seasonal temperature profiles varied with distance from the plant; a cool water plume was evident in spring and a warm water plume was present in the summer, fall, and winter. A cold water plume also developed in the northern section of the reservoir due to the operation of Jocassee Pumped Storage Station. Increases in the mean water temperature of the reservoir during operational periods were correlated with the generating output of the power plant. The annual heat load to the reservoir increased by one-third after plant operations began. The alteration of the thermal stratification of the receiving water during the summer also caused the dissolved oxygen to mix to greater depths.

Sources of tropospheric ozone along the Asian Pacific Rim: An analysis of ozonesonde observations

NASA Astrophysics Data System (ADS)

Liu, Hongyu; Jacob, Daniel J.; Chan, Lo Yin; Oltmans, Samuel J.; Bey, Isabelle; Yantosca, Robert M.; Harris, Joyce M.; Duncan, Bryan N.; Martin, Randall V.

2002-11-01

The sources contributing to tropospheric ozone over the Asian Pacific Rim in different seasons are quantified by analysis of Hong Kong and Japanese ozonesonde observations with a global three-dimensional (3-D) chemical transport model (GEOS-CHEM) driven by assimilated meteorological observations. Particular focus is placed on the extensive observations available from Hong Kong in 1996. In the middle-upper troposphere (MT-UT), maximum Asian pollution influence along the Pacific Rim occurs in summer, reflecting rapid convective transport of surface pollution. In the lower troposphere (LT) the season of maximum Asian pollution influence shifts to summer at midlatitudes from fall at low latitudes due to monsoonal influence. The UT ozone minimum and high variability observed over Hong Kong in winter reflects frequent tropical intrusions alternating with stratospheric intrusions. Asian biomass burning makes a major contribution to ozone at <32°N in spring. Maximum European pollution influence (<5 ppbv) occurs in spring in the LT. North American pollution influence exceeds European influence in the UT-MT, reflecting the uplift from convection and the warm conveyor belts over the eastern seaboard of North America. African outflow makes a major contribution to ozone in the low-latitude MT-UT over the Pacific Rim during November-April. Lightning influence over the Pacific Rim is minimum in summer due to westward UT transport at low latitudes associated with the Tibetan anticyclone. The Asian outflow flux of ozone to the Pacific is maximum in spring and fall and includes a major contribution from Asian anthropogenic sources year-round.

Sources of Tropospheric Ozone along the Asian Pacific Rim: An Analysis of Ozonesonde Observations

NASA Technical Reports Server (NTRS)

Liu, Hong-Yu; Jacob, Daniel J.; Chan, Lo Yin; Oltmans, Samuel J.; Bey, Isabelle; Yantosca, Robert M.; Harris, Joyce M.; Duncan, Bryan N.; Martin, Randall V.

2002-01-01

The sources contributing to tropospheric ozone over the Asian Pacific Rim in different seasons are quantified by analysis of Hong Kong and Japanese ozonesonde observations with a global three-dimensional (3-D) chemical transport model (GEOS-CHEM) driven by assimilated meteorological observations. Particular focus is placed on the extensive observations available from Hong Kong in 1996. In the middle-upper troposphere (MT- UT), maximum Asian pollution influence along the Pacific Rim occurs in summer, reflecting rapid convective transport of surface pollution. In the lower troposphere (LT) the season of maximum Asian pollution influence shifts to summer at midlatitudes from fall at low latitudes due to monsoonal influence. The UT ozone minimum and high variability observed over Hong Kong in winter reflects frequent tropical intrusions alternating with stratospheric intrusions. Asian biomass burning makes a major contribution to ozone at less than 32 deg.N in spring. Maximum European pollution influence (less than 5 ppbv) occurs in spring in the LT. North American pollution influence exceeds European influence in the UT-MT, reflecting the uplift from convection and the warm conveyor belts over the eastern seaboard of North America. African outflow makes a major contribution to ozone in the low-latitude MT-UT over the Pacific Rim during November- April. Lightning influence over the Pacific Rim is minimum in summer due to westward UT transport at low latitudes associated with the Tibetan anticyclone. The Asian outflow flux of ozone to the Pacific is maximum in spring and fall and includes a major contribution from Asian anthropogenic sources year-round.

Enhancing management of fall-applied poultry litter with cover crop and subsurface band placement in no-till cotton

USDA-ARS?s Scientific Manuscript database

Whether yield reduction risk of cotton fertilized with fall-applied poultry litter in regions with warm fall or winter months can be minimized by applying the litter in subsurface bands in conjunction with winter cover crop is unknown. A field study was conducted in Mississippi to test whether litte...

The association of Antarctic krill Euphausia superba with the under-ice habitat.

PubMed

Flores, Hauke; van Franeker, Jan Andries; Siegel, Volker; Haraldsson, Matilda; Strass, Volker; Meesters, Erik Hubert; Bathmann, Ulrich; Wolff, Willem Jan

2012-01-01

The association of Antarctic krill Euphausia superba with the under-ice habitat was investigated in the Lazarev Sea (Southern Ocean) during austral summer, autumn and winter. Data were obtained using novel Surface and Under Ice Trawls (SUIT), which sampled the 0-2 m surface layer both under sea ice and in open water. Average surface layer densities ranged between 0.8 individuals m(-2) in summer and autumn, and 2.7 individuals m(-2) in winter. In summer, under-ice densities of Antarctic krill were significantly higher than in open waters. In autumn, the opposite pattern was observed. Under winter sea ice, densities were often low, but repeatedly far exceeded summer and autumn maxima. Statistical models showed that during summer high densities of Antarctic krill in the 0-2 m layer were associated with high ice coverage and shallow mixed layer depths, among other factors. In autumn and winter, density was related to hydrographical parameters. Average under-ice densities from the 0-2 m layer were higher than corresponding values from the 0-200 m layer collected with Rectangular Midwater Trawls (RMT) in summer. In winter, under-ice densities far surpassed maximum 0-200 m densities on several occasions. This indicates that the importance of the ice-water interface layer may be under-estimated by the pelagic nets and sonars commonly used to estimate the population size of Antarctic krill for management purposes, due to their limited ability to sample this habitat. Our results provide evidence for an almost year-round association of Antarctic krill with the under-ice habitat, hundreds of kilometres into the ice-covered area of the Lazarev Sea. Local concentrations of postlarval Antarctic krill under winter sea ice suggest that sea ice biota are important for their winter survival. These findings emphasise the susceptibility of an ecological key species to changing sea ice habitats, suggesting potential ramifications on Antarctic ecosystems induced by climate change.

Psychoneuroendocrine effects of combined thyroxine and triiodothyronine versus tyrosine during prolonged Antarctic residence.

PubMed

Palinkas, Lawrence A; Reedy, Kathleen R; Smith, Mark; Anghel, Mihai; Steel, Gary D; Reeves, Dennis; Shurtleff, David; Case, H Samuel; Van Do, Nhan; Reed, H Lester

2007-12-01

We previously reported that cognitive function improves with thyroxine and that there is a circannual pattern to mood and human TSH during Antarctic residence. To extend these findings, we examined the effects of tyrosine and a combined levothyroxine/liothyronine supplement in euthyroid men and women who spent the austral summer (n = 43) and/or winter (n = 42) in Antarctica. Randomized, placebo-controlled, clinical trial. Subjects were randomized to receive the following each day for 91.6 +/- 3.2 days in summer and/or 138.0 +/- 3.2 days in winter: (1) 12g tyrosine mixed in 113g applesauce; (2) 50 microg of levothyroxine and 12.5 microg of liothyronine (T4-T3 Supplement); or (3) placebo. Cognitive performance and mood were assessed using the Automatic Neuropsychological Assessment Metric - Isolated and Confined Environments. With placebo in summer, mood did not change while TSH decreased by 28%; in winter, there was a 136% degradation in mood (p < 0.01) and TSH increased by 18%. With combined T4-T3 supplement, there was a 51% degradation in mood in summer compared with placebo (p < 0.05) and TSH decreased by 57%; in winter there was a 135% degradation in mood while TSH was reduced by 26% (p < 0.05). Tyrosine use in summer was associated with no change in mood and a 30% decline in TSH, while in winter there was a 47% improvement in mood and TSH decreased by 28% along with a 6% increase in fT3 (p < 0.05). Administration of tyrosine leads to a significant reduction in serum TSH and improvement in mood in winter compared with placebo, while the combined T4-T3 supplement leads to a worsening of mood in summer and no improvement in winter. There appears to be a seasonal influence on the psychological response to interventions and the relationship to changes in TSH reductions.

The Association of Antarctic Krill Euphausia superba with the Under-Ice Habitat

PubMed Central

Flores, Hauke; van Franeker, Jan Andries; Siegel, Volker; Haraldsson, Matilda; Strass, Volker; Meesters, Erik Hubert; Bathmann, Ulrich; Wolff, Willem Jan

2012-01-01

The association of Antarctic krill Euphausia superba with the under-ice habitat was investigated in the Lazarev Sea (Southern Ocean) during austral summer, autumn and winter. Data were obtained using novel Surface and Under Ice Trawls (SUIT), which sampled the 0–2 m surface layer both under sea ice and in open water. Average surface layer densities ranged between 0.8 individuals m−2 in summer and autumn, and 2.7 individuals m−2 in winter. In summer, under-ice densities of Antarctic krill were significantly higher than in open waters. In autumn, the opposite pattern was observed. Under winter sea ice, densities were often low, but repeatedly far exceeded summer and autumn maxima. Statistical models showed that during summer high densities of Antarctic krill in the 0–2 m layer were associated with high ice coverage and shallow mixed layer depths, among other factors. In autumn and winter, density was related to hydrographical parameters. Average under-ice densities from the 0–2 m layer were higher than corresponding values from the 0–200 m layer collected with Rectangular Midwater Trawls (RMT) in summer. In winter, under-ice densities far surpassed maximum 0–200 m densities on several occasions. This indicates that the importance of the ice-water interface layer may be under-estimated by the pelagic nets and sonars commonly used to estimate the population size of Antarctic krill for management purposes, due to their limited ability to sample this habitat. Our results provide evidence for an almost year-round association of Antarctic krill with the under-ice habitat, hundreds of kilometres into the ice-covered area of the Lazarev Sea. Local concentrations of postlarval Antarctic krill under winter sea ice suggest that sea ice biota are important for their winter survival. These findings emphasise the susceptibility of an ecological key species to changing sea ice habitats, suggesting potential ramifications on Antarctic ecosystems induced by climate change. PMID:22384073

Water availability change in central Belgium for the late 21st century

NASA Astrophysics Data System (ADS)

Tabari, Hossein; Taye, Meron Teferi; Willems, Patrick

2015-08-01

We investigate the potential impact of climate change on water availability in central Belgium. Two water balance components being precipitation and potential evapotranspiration are initially projected for the late 21st century (2071-2100) based on 30 Coupled Models Intercomparison Project phase 5 (CMIP5) models relative to a baseline period of 1961-1990, assuming forcing by four representative concentration pathway emission scenarios (RCP2.6, RCP4.5, RCP6.0, RCP8.5). The future available water is then estimated as the difference between precipitation and potential evapotranspiration projections. The number of wet days and mean monthly precipitation for summer season is projected to decrease in most of the scenarios, while the projections show an increase in those variables for the winter months. Potential evapotranspiration is expected to increase during both winter and summer seasons. The results show a decrease in water availability for summer and an increase for winter, suggesting drier summers and wetter winters for the late 21st century in central Belgium.

Hydrological simulation of a small ungauged agricultural watershed Semrakalwana of Northern India

NASA Astrophysics Data System (ADS)

Mishra, Himanshu; Denis, Derrick Mario; Suryavanshi, Shakti; Kumar, Mukesh; Srivastava, Santosh Kumar; Denis, Anjelo Francis; Kumar, Rajendra

2017-10-01

A study was conducted to develop a hydrological model for agriculture dominated Semra watershed (4.31 km2) and Semrakalwana village at Allahabad using a semi distributed Soil and Water Assessment Tool (SWAT) model. In model evaluation it was found that the SWAT does not require much calibration, and therefore, can be employed in unguaged watershed. A seasonal (Kharif, Rabi and Zaid seasons) and annual water budget analysis was performed to quantify various components of the hydrologic cycle. The average annual surface runoff varied from 379 to 386 mm while the evapotranspiration of the village was in the range of 359-364 mm. The average annual percolation and return flow was found to be 265-272 mm and 147-255 mm, respectively. The initial soil water content of the village was found in the range of 328-335 mm while the final soil water content was 356-362 mm. The study area fall under a rain-fed river basin (Tons River basin) with no contribution from snowmelt, the winter and summer season is highly affected by less water availability for crops and municipal use. Seasonal (Rabi, Kharif and Zaid crop seasons) and annual water budget of Semra watershed and Semrakalwana village evoke the need of conservation structures such as check dams, farm ponds, percolation tank, vegetative barrier, etc. to reduce monsoon runoff and conserve it for basin requirements for winter and summer period.

Contrasting Secondary Organic Aerosol Formation in Aerosol Liquid Water During Summer and Winter

NASA Astrophysics Data System (ADS)

El-Sayed, M.; Hennigan, C. J.

2017-12-01

In this study, we characterize the formation of aqueous secondary organic aerosols (aqSOA) in the eastern United States during summer and winter. The aim was to identify the main factors affecting the reversible and irreversible uptake of water-soluble organic gases to aerosol liquid water under variable influence from biogenic and anthropogenic sources. The reversible and irreversible uptake of water-soluble organic gases to aerosol water was measured in Baltimore, MD using a recently developed on-line method. The formation of aqSOA was observed during the summer and the winter; however, the amount of aqSOA varied significantly between the two seasons, as did the reversible and irreversible nature of the uptake. While the availability of aerosol liquid water (ALW) predominantly controlled aqSOA formation in the summer, wintertime aqSOA formation was limited by precursor VOCs as well. During the summer, aqSOA formation was tightly linked with isoprene oxidation, while the aqSOA formed in the winter was associated with biomass burning. Irreversible aqSOA was formed in both seasons; however, reversible aqSOA was only observed in the summer. Overall, these results demonstrate the importance of multi-phase chemistry in aerosol formation and underscore the significance of soluble organic gases partitioning to aerosol water both reversibly and irreversibly.