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Sample records for northern conditions influencing

  1. Nutritional condition of Northern Yellowstone Elk

    USGS Publications Warehouse

    Cook, R.C.; Cook, J.G.; Mech, L.D.

    2004-01-01

    Ultrasonography and body condition scoring was used to estimate nutritional condition of northern Yellowstone elk in late winter. Probability of pregnancy was related to body fat, and lactating cows had 50% less fat than non-lactating cows. For mild to normal winters, most of the elk were in good condition.

  2. Influence of Sub-Surface Irrigation on Soil Conditions and Water Irrigation Efficiency in a Cherry Orchard in a Hilly Semi-Arid Area of Northern China

    PubMed Central

    Peng, Gao; Bing, Wang; Guangcan, Zhang

    2013-01-01

    Sub-surface irrigation (SUI) is a new water-saving irrigation technology. To explore the influence of SUI on soil conditions in a cherry orchard and its water-saving efficiency, experiments were conducted from 2009 to 2010 using both SUI and flood irrigation (FLI) and different SUI quotas in hilly semi-arid area of northern China. The results demonstrated the following: 1) The bulk density of the soil under SUI was 6.8% lower than that of soil under FLI (P<0.01). The total soil porosity, capillary porosity and non-capillary porosity of soils using SUI were 11.7% (P<0.01), 8.7% (P<0.01) and 43.8% (P<0.01) higher than for soils using FLI. 2) The average soil temperatures at 0, 5, 10, 15 and 20 cm of soil depth using SUI were 1.7, 1.1, 0.7, 0.4 and 0.3°C higher than those for FLI, specifically, the differences between the surface soil layers were more significant. 3) Compared with FLI, the average water-saving efficiency of SUI was 55.6%, and SUI increased the irrigation productivity by 7.9-12.3 kg m-3 ha-1. 4) The soil moisture of different soil layers using SUI increased with increases in the irrigation quotas, and the soil moisture contents under SUI were significantly higher in the 0-20 cm layer and in the 21-50 cm layer than those under FLI (P<0.01). 5) The average yields of cherries under SUI with irrigation quotas of 80-320 m3 ha-1 were 8.7%-34.9% higher than those in soil with no irrigation (CK2). The average yields of cherries from soils using SUI were 4.5%-12.2% higher than using FLI. It is appropriate to irrigate 2-3 times with 230 m3 ha-1 per application using SUI in a year with normal rainfall. Our findings indicated that SUI could maintain the physical properties, greatly improve irrigation water use efficiency, and significantly increase fruit yields in hilly semi-arid areas of northern China. PMID:24039986

  3. Influence of slab thermal structure on basalt source regions and melting conditions: REE and HFSE constraints from the Garibaldi volcanic belt, northern Cascadia subduction system

    NASA Astrophysics Data System (ADS)

    Green, Nathan L.

    2006-03-01

    Garibaldi volcanic belt (GVB) basalts were erupted above the relatively young (≤ 24 Ma) Juan de Fuca plate, which comprises the subducted oceanic lithosphere that becomes progressively younger (22-13 Ma), and presumably hotter, northward along the northern Cascadia convergent margin. Primitive and near-primitive mafic lavas of the 15-km-wide volcanic belt change from high-alumina olivine tholeiites and magnesian andesites near Glacier Peak, northwestern Washington, through transitional basalts to alkali-olivine basalts and basanites in the Bridge River-Salal Glacier areas, southwestern British Columbia. The distribution of different basalt types is consistent with varied source conditions imposed by differences in the thermal structure of the underlying subducted plate. Significant arc-parallel variations characterize REE and HFSE contents in GVB basalts and suggest that source enrichment processes and melting conditions vary within the mantle wedge as the age and thermal state of the underlying subducted plate changes. More northerly GVB basaltic suites tend to have higher TiO 2, Nb, Ta, total REE, La, Sm / Yb, Nb / Yb, Ti / V, Y / Sc and Zr / Yb and lower Th / U, Zr / Ti and Zr / Nb than their southern counterparts. The basalts have sub-chondritic to chondritic Nb / Ta (6-21) and super-chondritic Zr / Hf (up to 55.90) ratios that exhibit positive correlation. Only Mount Baker and Glacier Peak basalts exhibit the distinctive negative Nb-Ta anomalies associated with arc lavas. Inter-HFSE and REE fractionations (including La / Yb, La / Nb and Ce / Pb) show significant correlations with the inferred age of the underlying subducted plate. Proportions of slab-derived HFSE-REE components (SC) transferred to basalt sources in the Cascadia mantle wedge appear to vary from negligible (Ti, Nb, Ta, Zr, Hf, Y, Sm, Eu and Tb: less than 15% SC) to perceptible (Nd: up to 35% SC) through moderate (La: up to 75% SC) to substantial (U, Th and Pb: up to 95% SC). Arc-parallel HFSE

  4. Selective Influence through Conditional Independence.

    ERIC Educational Resources Information Center

    Dzhafarov, Ehtibar N.

    2003-01-01

    Presents a generalization and improvement for the definition proposed by E. Dzhafarov (2001) for selectiveness in the dependence of several random variables on several (sets of) external factors. This generalization links the notion of selective influence with that of conditional independence. (SLD)

  5. Season - dependent and source-influenced aerosol in Northern Siberia

    NASA Astrophysics Data System (ADS)

    Popovicheva, Olga; Makshtas, Alexander; Bogorodsky, Peter; Eleftheriadis, Kostantinos; Diapouli, Evangelia; Shonia, Natalia; Uttal, Taneil

    2016-04-01

    Aerosol may serve as a tracer of arctic pollution, allowing a link to climate response if its major characteristics relating to natural and anthropogeneous sources are defined. It has been shown that BC and sulfates are the most important aerosol constituents measured in the Arctic boundary layer; these species demonstrate similar seasonal variations with a peak during winter to early spring and a minimum in summer. Long - time gap in consistent aerosol observations in the Russian Arctic strongly limits the assessment of air pollution and climate impacts. On-line monitoring, sampling, and analyses of atmospheric aerosols were carried out at the Tiksi Hydrometeorological Observatory, Northern Siberia, during one year from September 2014 to 2015. Physico-chemical characterization combining aethalometry, thermo-optical analysis, and analytical chemistry was used in order to identify the seasonal variability of aerosols and to link their composition to possible sources, as well as to characterize the differences in aerosol chemical composition between natural background conditions and BC-pollution episodes. The present study reports the first results from the Tiksi Observatory on season-dependent and source-influenced characteristics of aerosol species, such as carbon fractions (OC, EC), inorganic and organic functionalities of chemical compounds, sulfates, nitrates and other ion components, and elements. In addition, data obtained by individual particles analysis provide insight into micromarkers of combustion sources. Aerosol at the Tiksi Observatory is found to be originated from natural marine, biogenic, and continental sources as well as influenced by local residential activity and regional pollution. Characterization of aerosols during OC and BC-pollution episodes, combined with analysis of the wind direction, atmosphere stability, and air mass trajectories, allows for the identification of the sources which are responsible for the emission of hazardous compounds

  6. Two rare northern Entoloma species observed in Sicily under exceptionally cold weather conditions.

    PubMed

    Venturella, Giuseppe; Saitta, Alessandro; Mandracchia, Gerlando; Gargano, Maria Letizia

    2012-01-01

    The biology and ecology of many Entoloma species is still poorly known as well as their geographical distribution. In Italy, there are no studies on the influence of weather on fungal abundance and richness and our knowledge on the ecology and distribution of Entoloma species needs to be improved. The discovery of two Entoloma species in Sicily (southern Italy), reported in the literature as belonging to the habitat of north European countries, was the basis leading to the assumption that anomalous climatic conditions could stimulate the growth of northern entolomas in the southernmost Mediterranean regions. The results of this study show that the presence of northern Entoloma species in Sicily is not influenced by the Mediterranean type of vegetation, by edaphic or altitudinal factors but by anomalous climatic trends of precipitations and temperatures which stimulate the fructification of basidiomata in correspondence with a thermal shock during autumn.

  7. Factors influencing reproductive performance of northern bobwhite in South Florida

    USGS Publications Warehouse

    Rolland, V.; Hostetler, J.A.; Hines, T.C.; Percival, H.F.; Oli, M.K.

    2011-01-01

    Reproductive success is a critical component of individual fitness, and also an important determinant of growth rates of populations characterized by early maturity and high fecundity. We used radiotelemetry data collected during 2003-2008 to estimate reproductive parameters in a declining northern bobwhite (Colinus virginianus) population in South Florida, and to test hypotheses regarding factors influencing these parameters. The overall clutch size was 12.10 ?? 0.22, but females laid more eggs in their first clutch (12.43 ?? 0.24) than in subsequent clutches (10.19 ?? 0.53) within a nesting season. Daily nest survival was higher for first (0.966 ?? 0.003) than subsequent nests (0.936 ?? 0.011). Hatchability (proportion of laid eggs that hatched conditional upon nest survival to hatching) was 0.853 ?? 0.008, but was higher for nests incubated by females (0.873 ?? 0.009) than those incubated by males (0.798 ?? 0.018). The proportion of individuals attempting a second nest was 0.112 ?? 0.024 and 0.281 ?? 0.040 when the first nest was successful and failed, respectively. Hatchability was lower when the nesting habitat was burned the previous winter. We found no evidence that food strip density (a management practice to provide supplemental food) influenced any of the reproductive parameters. Mean summer temperature affected hatchability, nest survival, and proportion of nests incubated by males. Overall, the reproductive output in our study population was lower than that reported for most other bobwhite populations, indicating that low reproductive performance may have contributed to bobwhite population declines in our study site. These results suggest that current management practices, particularly those related to habitat and harvest management, need careful evaluation. ?? 2010 Springer-Verlag.

  8. Atmospheric and oceanologic conditions favouring large bioproduction of northern Adriatic

    NASA Astrophysics Data System (ADS)

    Kraus, Romina; Lučić, Davor; Njire, Jakica; Djakovac, Tamara; Precali, Robert; Supić, Nastjenjka

    2016-04-01

    An interdisciplinary study based on long term data collected in the northern Adriatic relieved winter period to be crucial for the total annual zooplankton production in the region. Namely, yearly averages of some investigated zooplankton species in the 2000-2007 interval were highly related to their February and/or March abundances. The large winter zooplankton abundances appeared in winters of the "A type", in which freshened waters from the Po River spread over the region. Also, the production of phytoplankton was in winters of the "A type" higher than in winters of the "B type", in which these waters are restricted to the coastal areas and do not impact the open sea. That was presumably due to increase in nutrients. In fact, the total inorganic nitrogen and ortophosphate concentration in eastern part reached maximal February values in the 1990-2007 interval in winters of the "A type". Spreading of the Po River water across the northern Adriatic and appearance of the two winter types depends on the existing geostrophic circulation patterns and atmospheric and hydrologic conditions in the preceding months, thus enabling forecast. Obtained results are basis for the future theoretical ecological model which can explain long term changes in bioproduction in the region and be used in planning future environment actions aimed to sustained development, especially as winter phytoplankton and zooplankton production seems to reflect on annual catch of small pelagic fish important for Adriatic fishery, anchovy (Engraulis encrasicolus).

  9. Conditions influencing the marketing efforts of hospitals.

    PubMed

    Myrtle, R C; Martinez, C F

    1990-01-01

    This research assesses the degree to which environmental change, competitive conditions and position, hospital characteristics, and organizational performance influence the extensiveness of a hospital's marketing activities. Changes in occupancy, revenue, and patient mix did not predict the level of marketing activities. Instead, the perceptions of marketing decision makers about changing environmental conditions were found to predict these activities.

  10. Influences Preceding "Nunatsiavut" Self-Determination: Historical, Political and Educational Influences on the People of Northern Labrador (Canada)

    ERIC Educational Resources Information Center

    Anderson, Kirk David

    2007-01-01

    What were the influences on the Inuit of Northern Labrador preceding the creation of the self-governing territory of Nunatsiavut? What are the preterritorial influences of the Inuit on the territory's five schools? To answer these questions and to share the success of one Indigenous people, the Nunatsiavut Inuit (the Inuit of Northern Labrador,…

  11. Environmental factors that influence prescribed burning in the Northern Plains

    USGS Publications Warehouse

    Kruse, A.D.; Higgins, K.F.; Piehl, J.L.

    1983-01-01

    Several environmental conditions were recorded and analyzed for 192 prescribed burns in the Northern Great Plains. The purpose of these burns was to improve wildlife habitat and manipulate native prairie vegetation. All of the fires occurred in grassland and shrubsteppe vegetation types. Fuels were predominantly grasses and forbs intermixed with patches of shrubs. Nearly all of the fuels were 0.05 cm/h, do not burn. However, these are good conditions to burn stockpiles of unwanted fuels that are usually high risk elements during regular prescribed burns.2) Produce partial burns. Partial burns are defined as those where fire is discontinuous and patches of standing and lodged vegetation are left unburned. Partial burns occur most often when fine fuels feel moist when handled, where less than 2 days have passed since the last measurable precipitation, and when cloud cover is complete. Other conditions associated with partial burns are relative humidities >50 percent, temperatures 32 km/h, relative humidities 35 deg.C. These conditions occur most often in July, August, and September, but can occur anytime from April through October.

  12. Icing Conditions Over Northern Eurasia in Changing Climate

    NASA Astrophysics Data System (ADS)

    Bulygina, O.; Arzhanova, N.; Groisman, P. Y.

    2013-12-01

    Climate of the Russian Federation for the national territory. This Reference Book addresses the current state of these weather phenomena. However, the ongoing and projected humidity changes in the high latitudes will strongly affect the circum-polar area (land and ocean) and impact the frequency and intensity of these potentially dangerous weather phenomena across the entire extratropical land area. Therefore the goal of the present study is to quantify icing conditions over the northern Eurasia. Our analysis includes data of 958 Russian stations from 1977 to 2012. Regional analysis of gololed characteristics was carried out using quasi-homogeneous climatic regions. Maps (climatology, trends) are presented mostly for visualization purposes. The area-averaging technique using station values converted to anomalies with respect to a common reference period (in this study, from 1977 to 2012). Anomalies were arithmetically averaged first within 1N x 2E grid cells and thereafter by a weighted average value derived over the quasi-homogeneous climatic regions. This approach provides a more uniform spatial field for averaging.

  13. Young children's awareness of violence in Northern Ireland: the influence of Northern Irish television in Scotland and Northern Ireland.

    PubMed

    Cairns, E; Hunter, D; Herring, L

    1980-02-01

    Children aged 5 to 6 years living in either a suburb of London or in a small town in Northern Ireland which has been virtually free from violence, were asked to make up stories in response to a series of pictures depicting such things as derelict houses or a train crash. More Northern Irish children mentioned bombs and explosions than did the London children. To investigate the possibility that this knowledge of explosions might be the result of at least incidental exposure to coverage of such events on Northern Irish television news a further study was initiated. Children from another relatively quiet part of Northern Ireland were compared with children from two separate areas of Scotland where television reception is only possible from Northern Ireland and from a third area in Scotland where Northern Ireland television news cannot be received. Children from those areas where Northern Irish television news can be received again outnumbered those from the control area in terms of mentions of the words bomb or explosion. PMID:7357227

  14. Game theory, conditional preferences, and social influence.

    PubMed

    Stirling, Wynn C; Felin, Teppo

    2013-01-01

    Neoclassical noncooperative game theory is based on a simple, yet powerful synthesis of mathematical and logical concepts: unconditional and immutable preference orderings and individual rationality. Although this structure has proven useful for characterizing competitive multi-player behavior, its applicability to scenarios involving complex social relationships is problematic. In this paper we directly address this limitation by the introduction of a conditional preference structure that permits players to modulate their preference orderings as functions of the preferences of other players. Embedding this expanded preference structure in a formal and graphical framework provides a systematic approach for characterizing a complex society. The result is an influence network that allows conditional preferences to propagate through the community, resulting in an emergent social model which characterizes all of the social relationships that exist and which leads to solution concepts that account for both group and individual interests. The Ultimatum game is presented as an example of how social influence can be modeled with conditional preferences.

  15. Environmental Conditions in northern Gulf of Mexico Estuaries: before and after the BP Oil Spill

    EPA Science Inventory

    This presentation provides a summary of ecological condition and sediment chemistry data for northern Gulf of Mexico estuaries that were exposed to oil and oil-related contaminants from the BP Oil Spill.

  16. Harmful and favourable ultraviolet conditions for human health over Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Chubarova, Nataly; Zhdanova, Ekaterina

    2014-05-01

    We provide the analysis of the spatial and temporal distribution of ultraviolet (UV) radiation over Northern Eurasia taking into account for both its detrimental (erythema and eye-damage effects) and favourable (vitamin D synthesis) influence on human health. The UV effects on six different skin types are considered in order to cover the variety of skin types of European and Asian inhabitants. To better quantifying the vitamin D irradiance threshold we accounted for an open body fraction S as a function of effective air temperature. The spatial and temporal distribution of UV resources was estimated by radiative transfer (RT) modeling (8 stream DISORT RT code) with 1x 1 degree grid and monthly resolution. For this purpose special datasets of main input geophysical parameters (total ozone content, aerosol characteristics, surface UV albedo, UV cloud modification factor) have been created over the territory of Northern Eurasia, which can be of separate interest for the different multidisciplinary scientific applications over the PEEX domain. The new approaches were used to retrieve aerosol and cloud transmittance from different satellite and re-analysis datasets for calculating the solar UV irradiance at ground. Using model simulations and some experimental data we provide the altitude parameterization for different types of biologically active irradiance in mountainous area taking into account not only for the effects of molecular scattering but for the altitude dependence of aerosol parameters and surface albedo. Based on the new classification of UV resources (Chubarova, Zhdanova, 2013) we show that the distribution of harmful (UV deficiency and UV excess) and favorable UV conditions is regulated by various geophysical parameters (mainly, total ozone, cloudiness and open body fraction) and can significantly deviate from latitudinal dependence. The interactive tool for providing simulations of biologically active irradiance and its attribution to the different

  17. The northern Yellowstone elk: density dependence and climatic conditions

    USGS Publications Warehouse

    Taper, Mark L.; Gogan, Peter J.P.

    2002-01-01

    We analyzed a time series of estimates of elk (Cervus elaphus) numbers on the northern Yellowstone winter range from 1964 to 1979 and 1986 to 1995 using a variety of discrete time stochastic population dynamic models. These models included adjustments for density, an increase in the area of winter range used by elk, lagged effects of the weather covariates of spring precipitation, snow depth and winter temperature, and the impacts of the 1988 drought and fires. An information-criteria-based model-selection process strongly supported evidence of density dependence. The best model, a Ricker model, distinguished between the 2 time periods. The bulk of the difference between the 2 periods is attributed to an increase in the amount of winter range used by elk. Inclusion of the covariates spring precipitation and spring precipitation squared greatly improved the model fit. We detected a short-lived increase in elk population growth rate following the 1988 drought and fires. Fertility and survivorship of adults appeared to have different density-dependent forms that together result in a biphasic relationships between population growth rate and density. This study confirms the presence of density-dependent regulation in the norther Yellowstone elk herd, and enhances our understanding of population dynamics of these ungulates.

  18. Game Theory, Conditional Preferences, and Social Influence

    PubMed Central

    Stirling, Wynn C.; Felin, Teppo

    2013-01-01

    Neoclassical noncooperative game theory is based on a simple, yet powerful synthesis of mathematical and logical concepts: unconditional and immutable preference orderings and individual rationality. Although this structure has proven useful for characterizing competitive multi-player behavior, its applicability to scenarios involving complex social relationships is problematic. In this paper we directly address this limitation by the introduction of a conditional preference structure that permits players to modulate their preference orderings as functions of the preferences of other players. Embedding this expanded preference structure in a formal and graphical framework provides a systematic approach for characterizing a complex society. The result is an influence network that allows conditional preferences to propagate through the community, resulting in an emergent social model which characterizes all of the social relationships that exist and which leads to solution concepts that account for both group and individual interests. The Ultimatum game is presented as an example of how social influence can be modeled with conditional preferences. PMID:23451078

  19. Body condition of Morelet’s Crocodiles (Crocodylus moreletii) from northern Belize

    USGS Publications Warehouse

    Mazzotti, Frank J.; Cherkiss, Michael S.; Brandt, Laura A.; Fujisaki, Ikuko; Hart, Kristen; Jeffery, Brian; McMurry, Scott T.; Platt, Steven G.; Rainwater, Thomas R.; Vinci, Joy

    2012-01-01

    Body condition factors have been used as an indicator of health and well-being of crocodilians. We evaluated body condition of Morelet's Crocodiles (Crocodylus moreletii) in northern Belize in relation to biotic (size, sex, and habitat) and abiotic (location, water level, and air temperature) factors. We also tested the hypothesis that high water levels and warm temperatures combine or interact to result in a decrease in body condition. Size class, temperature, and water level explained 20% of the variability in condition of Morelet's Crocodiles in this study. We found that adult crocodiles had higher condition scores than juveniles/subadults but that sex, habitat, and site had no effect. We confirmed our hypothesis that warm temperatures and high water levels interact to decrease body condition. We related body condition of Morelet's Crocodiles to natural fluctuations in air temperatures and water levels in northern Belize, providing baseline conditions for population and ecosystem monitoring.

  20. Dissolved oxygen conditions in northern Gulf of Mexico estuaries

    USGS Publications Warehouse

    Engle, V.D.; Kevin, Summers J.; Macauley, J.M.

    1999-01-01

    Because deficient dissolved oxygen (DO) levels may have severe detrimental effects on estuarine and marine life, DO has been widely used as an indicator of ecological conditions by environmental monitoring programs. The U.S. EPA's Environmental Monitoring and Assessment Program for Estuaries (EMAP-E) monitored DO conditions in the estuaries of the Gulf of Mexico from 1991 to 1994. DO was measured in two ways: 1)instantaneous profiles from the surface to the bottom were taken during the day, and 2) continuous measurements were taken near the bottom at 15 min intervals for at least 12 h. This information was summarized to assess the spatial distribution and severity of DO conditions in these estuaries. Depending on the criteria used to define hypoxia (DO concentrations usually < 2 mg L-1 or 15 mg L-1) and the method by which DO is measured, we estimate that between 5.2 and 29.3% of the total estuarine area in the Louisianian Province was affected by low DO conditions.

  1. Influence of heavy snow on the feeding behavior of Japanese macaques (macaca fuscata) in northern Japan.

    PubMed

    Enari, Hiroto; Sakamaki-Enari, Haruka

    2013-06-01

    Natural disasters can degrade primate habitat and alter feeding behavior. Here, we examined the influence of unusually heavy snow on diet and feeding-site use by Japanese macaques (Macaca fuscata) in northern Japan. To compare the winter-feeding behavior under different snow conditions, we recorded the plant species foraged on by macaques in multiple transects of the Shirakami Mountains from 2008 to 2012 (excluding 2011). We used cluster analysis to describe foraged plant assemblages, and applied multiple dimensional scaling and decision tree modeling to evaluate annual variation in feeding-site use by macaques. Our cluster analysis revealed five types of foraged plant assemblages. The proportion of each type present in transects varied considerably across the years, indicating that the diet of macaques in heavy snow conditions was influenced more by resource accessibility than by preference. Multiple dimensional scaling and decision tree modeling demonstrated that heavy snow conditions restricted feeding-site use. Moreover, the distribution of refuges relative to severe external ambient environments was a stronger limiting factor for feeding-site use than was the availability of food resources. While most primate species facing unexpected starvation employ risk-prone foraging tactics (i.e., choosing the option with higher pay-off by accepting risk), Japanese macaques have a tendency to adopt risk-averse foraging behavior (i.e., minimizing energy loss when searching for preferred diet items under long-lasting heavy snow conditions), because winters with temperatures below freezing have higher thermoregulatory costs.

  2. Icing conditions over Northern Eurasia in changing climate

    NASA Astrophysics Data System (ADS)

    Bulygina, Olga N.; Arzhanova, Natalia M.; Groisman, Pavel Ya

    2015-02-01

    Icing conditions, particularly in combination with wind, affect greatly the operation of overhead communication and transmission lines causing serious failures, which result in tremendous economic damage. Icing formation is dangerous to agriculture, forestry, high seas fishery, for land and off coast man-made infrastructure. Quantitative icing characteristics such as weight, thickness, and duration are very important for the economy and human wellbeing when their maximum values exceed certain thresholds. Russian meteorological stations perform both visual and instrumental monitoring of icing deposits. Visual monitoring is ocular estimation of the type and intensity of icing and the date of ice appearance and disappearance. Instrumental monitoring is performed by ice accretion indicator that in addition to the type, intensity and duration of ice deposits reports also their weight and size. We used observations at 958 Russian stations for the period 1977-2013 to analyze changes in the ice formation frequency at individual meteorological stations and on the territory of quasi-homogeneous climatic regions in Russia. It was found that hoar frosts are observed in most parts of Russia, but icing only occurs in European Russia and the Far East. On the Arctic coast of Russia, this phenomenon can even be observed in summer months. Statistically significant decreasing trends in occurrence of icing and hoar frost events are found over most of Russia. An increasing trend in icing weights (IWs) was found in the Atlantic Arctic region in autumn. Statistically significant large negative trends in IWs were found in the Pacific Arctic in winter and spring.

  3. Land degradation and economic conditions of agricultural households in a marginal region of northern Greece

    NASA Astrophysics Data System (ADS)

    Lorent, Hugues; Evangelou, Christakis; Stellmes, Marion; Hill, Joachim; Papanastasis, Vasilios; Tsiourlis, Georgios; Roeder, Achim; Lambin, Eric F.

    2008-12-01

    Land degradation is caused by and has impacts on both the social and natural components of coupled human-environment systems. However, few studies integrate both aspects simultaneously. The main objective of this study is to test a method to evaluate land degradation based on the integration of aggregate metrics of biophysical and socio-economic "degradation". We applied a framework that integrates the biophysical and socio-economic dimensions of land degradation to test the hypothesis that macro-economic policies, and in particular agricultural subsidies, are an important driving force of land degradation in marginal regions of the Mediterranean Europe. We analysed the influence of subsidies on the profitability of each crop and livestock type found in a sample of farms in a region of northern Greece. Spatial and socio-economic data on agricultural households were collected to link remote sensing data and land degradation maps to socio-economic conditions of these households, as measured by the standard gross margin. The results demonstrate that subsidies provide a crucial socio-economic support to maintain the profitability of agricultural activities but may also promote land-use practices with damaging ecological impacts. Different levels of biophysical and socio-economic "degradation" were associated with different land use practices. The integration of the socio-economic and biophysical dimensions of land degradation reveals associations that would not be detectable if indicators along one dimension alone would be used.

  4. REFINEMENT, VALIDATION, AND APPLICATION OF A BENTHIC CONDITION INDEX FOR NORTHERN GULF OF MEXICO ESTUARIES

    EPA Science Inventory

    By applying discriminant analysis to benthic macroinvertebrate data to produce a benthic index, we have developed an indicator of benthic condition for northern Gulf of Mexico estuaries. The data used were collected by the U.S. Environmental Protection Agency's (USEPA) Environmen...

  5. Climatic and topographical influences on fire regime attributes in the northern Cascade Range, Washington, USA

    NASA Astrophysics Data System (ADS)

    Cansler, C.; McKenzie, D.

    2010-12-01

    We examined the influence of annual climate and topography on fire occurrence, size, severity, and within-fire severity pattern in the northern Cascade Range of Washington, USA. Landsat Thematic Mapper (LTM) data were used to quantify fire severity for all fires greater than 10 ha (n = 125) that occurred during a 25 year period (1984-2008). Categorical burn severity images were developed from an index of burn severity (Relative differenced Normalized Burn Ratio) derived from LTM data and parameterized with data from 639 field plots. Spring snowpack and summer temperature were negatively and positively correlated, respectively, with fire occurrence, annual area burned, and proportion of landscape burned at high severity. As the proportion of high severity within individual fires increased high severity patches became larger and increasingly spatially aggregated. Fires in areas with greater topographical complexity had lower proportional area burned at high severity, decreased spatial aggregation of individual burn severity classes, and more complex overall patch structure. These results show that the fire regime of the northern Cascade Range responds to annual climatic variation. Nevertheless, within-fire severity mosaic reflects the underlying topographic complexity, even under climatic conditions conducive to the development of large fires. Several recent studies in the western United States have documented a positive relationship between warm and dry climate conditions and annual area burned. The relationship between climate drivers and fire regime attributes identified in this study—a positive relationship between warm and dry conditions and both proportion of area burned at high severity and greater spatial aggregation of high severity patches—add nuance the climate-area burned relationship documented in previous studies.

  6. Characterization of aerosols above the Northern Adriatic Sea: Case studies of offshore and onshore wind conditions

    NASA Astrophysics Data System (ADS)

    Piazzola, J.; Mihalopoulos, N.; Canepa, E.; Tedeschi, G.; Prati, P.; Zarmpas, P.; Bastianini, M.; Missamou, T.; Cavaleri, L.

    2016-05-01

    Aerosol particles in coastal areas result from a complex mixing between sea spray aerosols locally generated at the sea surface by the wind-waves interaction processes and a continental component resulting from natural and/or anthropogenic sources. This paper presents a physical and chemical analysis of the aerosol data acquired from May to September 2014 in the Adriatic Sea. Aerosol distributions were measured on the Acqua Alta platform located 15 km off the coast of Venice using two Particle Measuring System probes and a chemical characterization was made using an Ion Chromatography analysis (IC). Our aim is to study both the sea-spray contribution and the anthropogenic influence in the coastal aerosol of this Mediterranean region. To this end, we focus on a comparison between the present data and the aerosol size distributions measured south of the French Mediterranean coast. For air masses of marine origin transported by southern winds on the French coast and by the Sirocco in the Adriatic, we note a good agreement between the concentrations of super-micrometer aerosols measured in the two locations. This indicates a similar sea surface production of sea-spray aerosols formed by bubble bursting processes in the two locations. In contrast, the results show larger concentrations of submicron particles in the North-Western Mediterranean compared to the Adriatic, which result probably from a larger anthropogenic background for marine conditions. In contrast, for a coastal influence, the chemical analysis presented in the present paper seems to indicate a larger importance of the anthropogenic impact in the Northern Adriatic compared to the North-Western Mediterranean.

  7. February 2003 marine atmospheric conditions and the bora over the northern Adriatic

    USGS Publications Warehouse

    Dorman, C.E.; Carniel, S.; Cavaleri, L.; Sclavo, M.; Chiggiato, J.; Doyle, J.; Haack, T.; Pullen, J.; Grbec, B.; Vilibic, I.; Janekovic, I.; Lee, C.; Malacic, V.; Orlic, M.; Paschini, E.; Russo, A.; Signell, R.P.

    2007-01-01

    A winter oceanographic field experiment provided an opportunity to examine the atmospheric marine conditions over the northern Adriatic. Mean February winds are from a northeasterly direction over most of the Adriatic and a more northerly direction along the western coast. Wind speeds are fastest in jets over the NE coast during bora events and weakest in the mid-northwestern Adriatic. Diurnal air temperature cycles are smallest on the NE coast and largest in the midwestern Adriatic. The maximum sea-air difference is +10??C on the eastern coast and near zero on the midwestern Adriatic. Boras are northeasterly (from) wind events that sweep off Croatia and Slovenia, bringing slightly colder and drier air over the northern Adriatic. The main bora season is December to March. Winter 2002-2003 was normal for bora events. Synoptic-scale temporal variations are correlated over the northern Adriatic. Fastest Bora winds and highest wind stress over the northern Adriatic is concentrated in four topographically controlled jets. The strongest is the Senj Jet, while the Trieste Jet extends across the entire northern Adriatic. Between each two jets is a weak wind zone. The greatest mean net heat loss is in bora jets in the NE Adriatic, where it was -438 W m-2 and is weakest in the midwestern northern Adriatic, where it was near zero. Wind stress is concentrated over the NE half of Adriatic in four bora jets, while wind stress is weak in the NW Adriatic. There is significant variation in wind stress mean and standard deviation structure over the northern Adriatic with each bora event. Copyright 2006 by the American Geophysical Union.

  8. Processes influencing seasonal hypoxia in the northern California Current System

    PubMed Central

    Connolly, T. P.; Hickey, B. M.; Geier, S. L.; Cochlan, W. P.

    2010-01-01

    This paper delineates the role of physical and biological processes contributing to hypoxia, dissolved oxygen (DO) < 1.4 mL/L, over the continental shelf of Washington State in the northern portion of the California Current System (CCS). In the historical record (1950–1986) during the summer upwelling season, hypoxia is more prevalent and severe off Washington than further south off northern Oregon. Recent data (2003–2005) show that hypoxia over the Washington shelf occurred at levels previously observed in the historical data. 2006 was an exception, with hypoxia covering ~5000 km2 of the Washington continental shelf and DO concentrations below 0.5 mL/L at the inner shelf, lower than any known previous observations at that location. In the four years studied, upwelling of low DO water and changes in source water contribute to interannual variability, but cannot account for seasonal decreases below hypoxic concentrations. Deficits of DO along salinity surfaces, indicating biochemical consumption of DO, vary significantly between surveys, accounting for additional decreases of 0.5–2.5 mL/L by late summer. DO consumption is associated with denitrification, an indicator of biochemical sediment processes. Mass balances of DO and nitrate show that biochemical processes in the water column and sediments each contribute ~50% to the total consumption of DO in near-bottom water. At shorter than seasonal time scales on the inner shelf, along-shelf advection of hypoxic patches and cross-shelf advection of seasonal gradients are both shown to be important, changing DO concentrations by 1.5 mL/L or more over five days. PMID:20463844

  9. Cues of maternal condition influence offspring selfishness.

    PubMed

    Wong, Janine W Y; Lucas, Christophe; Kölliker, Mathias

    2014-01-01

    The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, offspring should adjust their behavior to cues/signals of parental condition: parents that differ in condition pay differential costs of care and, hence, should provide different amounts of food. In this study, we experimentally tested in the European earwig (Forficula auricularia) if cues of maternal condition affect offspring behavior in terms of sibling cannibalism. We experimentally manipulated female condition by providing them with different amounts of food, kept nymph condition constant, allowed for nymph exposure to chemical maternal cues over extended time, quantified nymph survival (deaths being due to cannibalism) and extracted and analyzed the females' cuticular hydrocarbons (CHC). Nymph survival was significantly affected by chemical cues of maternal condition, and this effect depended on the timing of breeding. Cues of poor maternal condition enhanced nymph survival in early broods, but reduced nymph survival in late broods, and vice versa for cues of good condition. Furthermore, female condition affected the quantitative composition of their CHC profile which in turn predicted nymph survival patterns. Thus, earwig offspring are sensitive to chemical cues of maternal condition and nymphs from early and late broods show opposite reactions to the same chemical cues. Together with former evidence on maternal sensitivities to condition-dependent nymph chemical cues, our study shows context-dependent reciprocal information exchange about condition between earwig mothers and their offspring, potentially mediated by cuticular hydrocarbons. PMID:24498046

  10. Cues of Maternal Condition Influence Offspring Selfishness

    PubMed Central

    Wong, Janine W. Y.; Lucas, Christophe; Kölliker, Mathias

    2014-01-01

    The evolution of parent-offspring communication was mostly studied from the perspective of parents responding to begging signals conveying information about offspring condition. Parents should respond to begging because of the differential fitness returns obtained from their investment in offspring that differ in condition. For analogous reasons, offspring should adjust their behavior to cues/signals of parental condition: parents that differ in condition pay differential costs of care and, hence, should provide different amounts of food. In this study, we experimentally tested in the European earwig (Forficula auricularia) if cues of maternal condition affect offspring behavior in terms of sibling cannibalism. We experimentally manipulated female condition by providing them with different amounts of food, kept nymph condition constant, allowed for nymph exposure to chemical maternal cues over extended time, quantified nymph survival (deaths being due to cannibalism) and extracted and analyzed the females’ cuticular hydrocarbons (CHC). Nymph survival was significantly affected by chemical cues of maternal condition, and this effect depended on the timing of breeding. Cues of poor maternal condition enhanced nymph survival in early broods, but reduced nymph survival in late broods, and vice versa for cues of good condition. Furthermore, female condition affected the quantitative composition of their CHC profile which in turn predicted nymph survival patterns. Thus, earwig offspring are sensitive to chemical cues of maternal condition and nymphs from early and late broods show opposite reactions to the same chemical cues. Together with former evidence on maternal sensitivities to condition-dependent nymph chemical cues, our study shows context-dependent reciprocal information exchange about condition between earwig mothers and their offspring, potentially mediated by cuticular hydrocarbons. PMID:24498046

  11. Oceanographic Conditions Off Northern Chile During the 1996 La Nina and 1997-1998 El Nino: Part1 - Hydrographic Conditions

    NASA Technical Reports Server (NTRS)

    Blanco, J.; Thomas, A.; Strub, T.; Carr, M.

    2000-01-01

    The evolution of oceanographic conditions in the upwelling region off northern Chile (18(sup o) - 24(sup o)S) betweeen 1996 and 1998 (including 1997-1998 El Nino) is presented using hydrographic measurements acquired on quarterly cruises of the Chilean Fisheries Institute, sea-surface temperature (SST), sea level, and wind speeds from Arica (18.5(sup o)S), Iquique (20.5(sup o)S), and Antofagasta (23.5(sup o)S), and a time series of vertical temperature profiles off Iquique.

  12. Pore size distribution and methane equilibrium conditions at Walker Ridge Block 313, northern Gulf of Mexico

    SciTech Connect

    Bihani, Abhishek; Daigle, Hugh; Cook, Ann; Glosser, Deborah; Shushtarian, Arash

    2015-12-15

    Coexistence of three methane phases (liquid (L), gas (G), hydrate (H)) in marine gas hydrate systems may occur according to in-situ pressure, temperature, salinity and pore size. In sediments with salinity close to seawater, a discrete zone of three-phase (3P) equilibrium may occur near the base of the regional hydrate stability zone (RHSZ) due to capillary effects. The existence of a 3P zone influences the location of the bottom-simulating reflection (BSR) and has implications for methane fluxes at the base of the RHSZ. We studied hydrate stability conditions in two wells, WR313-G and WR313-H, at Walker Ridge Block 313 in the northern Gulf of Mexico. We determined pore size distributions (PSD) by constructing a synthetic nuclear magnetic resonance (NMR) relaxation time distribution. Correlations were obtained by non-linear regression on NMR, gamma ray, and bulk density logs from well KC-151 at Keathley Canyon. The correlations enabled construction of relaxation time distributions for WR313-G and WR313-H, which were used to predict PSD through comparison with mercury injection capillary pressure measurements. With the computed PSD, L+H and L+G methane solubility was determined from in-situ pressure and temperature. The intersection of the L+G and L+H curves for various pore sizes allowed calculation of the depth range of the 3P equilibrium zone. As in previous studies at Blake Ridge and Hydrate Ridge, the top of the 3P zone moves upwards with increasing water depth and overlies the bulk 3P equilibrium depth. In clays at Walker Ridge, the predicted thickness of the 3P zone is approximately 35 m, but in coarse sands it is only a few meters due to the difference in absolute pore sizes and the width of the PSD. The thick 3P zone in the clays may explain in part why the BSR is only observed in the sand layers at Walker Ridge, although other factors may influence the presence or absence of a BSR.

  13. Pore Size Distribution and Methane Equilibrium Conditions at Walker Ridge Block 313, Northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Bihani, A. D.; Daigle, H.; Cook, A.; Glosser, D.; Shushtarian, A.

    2015-12-01

    Coexistence of three methane phases (liquid (L), gas (G), hydrate (H)) in marine gas hydrate systems may occur according to in-situ pressure, temperature, salinity and pore size. In sediments with salinity close to seawater, a discrete zone of three-phase (3P) equilibrium may occur near the base of the regional hydrate stability zone (RHSZ) due to capillary effects. The existence of a 3P zone influences the location of the bottom-simulating reflection (BSR) and has implications for methane fluxes at the base of the RHSZ. We studied hydrate stability conditions in two wells, WR313-G and WR313-H, at Walker Ridge Block 313 in the northern Gulf of Mexico. We determined pore size distributions (PSD) by constructing a synthetic nuclear magnetic resonance (NMR) relaxation time distribution. Correlations were obtained by non-linear regression on NMR, gamma ray, and bulk density logs from well KC-151 at Keathley Canyon. The correlations enabled construction of relaxation time distributions for WR313-G and WR313-H, which were used to predict PSD through comparison with mercury injection capillary pressure measurements. With the computed PSD, L+H and L+G methane solubility was determined from in-situ pressure and temperature. The intersection of the L+G and L+H curves for various pore sizes allowed calculation of the depth range of the 3P equilibrium zone. As in previous studies at Blake Ridge and Hydrate Ridge, the top of the 3P zone moves upwards with increasing water depth and overlies the bulk 3P equilibrium depth. In clays at Walker Ridge, the predicted thickness of the 3P zone is approximately 35 m, but in coarse sands it is only a few meters due to the difference in absolute pore sizes and the width of the PSD. The thick 3P zone in the clays may explain in part why the BSR is only observed in the sand layers at Walker Ridge, although other factors may influence the presence or absence of a BSR.

  14. Comparison of survival patterns of northern and southern genotypes of the North American tick Ixodes scapularis (Acari: Ixodidae) under northern and southern conditions

    USGS Publications Warehouse

    Ginsberg, Howard S.; Rulison, Eric L.; Azevedo, Alexandra; Pang, Genevieve C.; Kuczaj, Isis M.; Tsao, Jean I.; LeBrun, Roger A.

    2014-01-01

    Conclusions: Our results suggest that conditions in southern North America are less hospitable than in the north to populations of I. scapularis. Southern conditions might have resulted in ecological or behavioral adaptations that contribute to the relative rarity of I. scapularis borne diseases, such as Lyme borreliosis, in the southern compared to the northern United States.

  15. Comparison of survival patterns of northern and southern genotypes of the North American tick Ixodes scapularis (Acari: Ixodidae) under northern and southern conditions

    USGS Publications Warehouse

    Ginsberg, Howard S.; Rulison, Eric L.; Azevedo, Alexandra; Pang, Genevieve C.; Kuczaj, Isis M.; Tsao, Jean I.; LeBrun, Roger A.

    2014-01-01

    Our results suggest that conditions in southern North America are less hospitable than in the north to populations of I. scapularis. Southern conditions might have resulted in ecological or behavioral adaptations that contribute to the relative rarity of I. scapularis borne diseases, such as Lyme borreliosis, in the southern compared to the northern United States.

  16. Change of liver function during adaptation of man to northern conditions.

    PubMed

    Gichev JuP

    1990-04-01

    The liver is known to play a central part in carrying out the main phases of intermediate metabolism, in supplying the other organs and tissues with structure and energy substances. The investigations on the liver function of man in the process of organism adaptation to a variety of factors in northern regions are practically non-existent. This article has as its purpose a combined clinical and biochemical investigation of the main functions of the liver in people with various length of stay in extreme northern regions. The analysis of changes in the indices of the basic liver functions in practically healthy people during the process of adaptation to the extreme environmental conditions of the North show, that with a short-term adaptation these shifts were generally of a temporary character, whereas with a long-term adaptation of the newcomers there were relatively permanent changes in a number of indices.

  17. Influence of atmospheric stability and transport on CH4 concentrations in northern Spain.

    PubMed

    García, M Ángeles; Sánchez, M Luisa; Pérez, Isidro A; Ozores, Marta I; Pardo, Nuria

    2016-04-15

    Continuous methane (CH4) concentrations were measured in Northern Spain over two years (2011-2012) by multi-point sampling at 1.8, 3.7 and 8.3m using a Picarro analyser. The technique is based on cavity ring-down spectroscopy. The contrast in mean concentrations was about 1.2ppb, with 95th percentiles differing by 2.2ppb and mean minimum concentrations proving similar. Temporal variations of CH4 were also analysed, with a similar seasonal variability being found for the three heights. The highest CH4 concentrations were obtained in late autumn and winter and the lowest in summer, yielding a range of 52ppb. This variation may depend on the active photochemical reaction with OH radical during a period of intense solar radiation and changes in soil conditions together with variations in emissions. Peak concentration levels were recorded at night-time, between 5:00-7:00 GMT, with mean values ranging between 1920 and 1923ppb. The lowest value, around 1884ppb, was obtained at 16:00 GMT. This diurnal variation was mainly related to vertical mixing and photochemistry. Therefore, CH4 concentrations were also examined using the bulk Richardson number (RB) as a stability indicator. Four groups were distinguished: unstable cases, situations with pure shear flow, transitional stages and drainage flows. The highest contrast in mean CH4 concentrations between lower and upper heights was obtained for the transition and drainage cases, mainly associated to high concentrations from nearby sources. The impact of long range transport was analysed by means of 3-day isobaric backward air mass trajectories, which were calculated taking into account origins from Europe, Africa, the Atlantic Ocean and Local conditions. Assessment of the results showed the influence of S and SE wind sectors, especially with Local conditions associated with low winds. Finally, an estimation of the background CH4 concentration in the study period provided an average value of about 1892ppb. PMID:26815292

  18. Rare earth elements in coastal sediments of the northern Galician shelf: Influence of geological features

    NASA Astrophysics Data System (ADS)

    Prego, Ricardo; Caetano, Miguel; Bernárdez, Patricia; Brito, Pedro; Ospina-Alvarez, Natalia; Vale, Carlos

    2012-03-01

    The Northern coast of Galicia, NW Iberian Peninsula, exhibits a variety of geological features: Ortegal allochthonous complex, Ollo-de-Sapo autochthonous domain and massifs of Bares, Barqueiro and San-Ciprian. In order to examine the influence of terrestrial lithologies on coastal sediments, 103 samples were collected in the Rias of Ortigueira, Barqueiro and Viveiro, their neighbouring shelf and the estuaries of Mera, Sor and Landro rivers. Aluminium, Fe, Sc, particulate inorganic and organic carbon and rare earth elements (REE) were determined in the <2 mm fraction. In addition, calcite, muscovite, quartz and riebeckite minerals were identified and quantified in 33 selected samples. The distributions of riebeckite and Fe reflect the influence of Ortegal complex on the coastal areas around the Cape Ortegal. The highest concentrations of ΣREE were found in fine sediments from confined inner parts of the Rias (up to 233 mg kg-1), while most of the sands contained 11-70 mg kg-1. ΣREE normalised to European Shale (ES) highlights the relative abundance of lanthanides (ΣREEN>6) near Cape Ortegal and the innermost ria zones. The ratio between light and heavy REE (L/H) showed lower values (4-11) around Cape Ortegal and the shelf while higher ratios (15-23) were detected in west of the Cape Estaca-de-Bares and in the inner Viveiro Ria due to elevated contributions of La and Ce. The L/H values normalised to ES reflects the importance of HREE in the adjacent area to Ortegal Complex (LN/HN<0.8) and the LREE (LN/HN>1.4) in the inner estuaries and west Cape Estaca-de-Bares. The highest REE individual ES normalised were measured in fine-grained sediments of the Mera and Sor estuaries. Sediments from the eastern shelf of Cape Ortegal presented enhanced ratios only for HREE. These results indicate that distribution of REE in the northern Galician region is highly depending on the neighbouring lithological pattern, contrasting with the situation found in the western Galician

  19. Burnout, working conditions and gender - results from the northern Sweden MONICA Study

    PubMed Central

    2010-01-01

    Background Sick-leave because of mental and behavioural disorders has increased considerably in Sweden since the late nineties, and especially in women. The aim of this study was to assess the level of burnout in the general working population in northern Sweden and analyse it's relation to working conditions and gender. Methods In this cross-sectional study the survey from the MONICA-study (Monitoring of Trends and Determinants in Cardiovascular Disease) in northern Sweden 2004 was used. A burnout instrument, the Shirom Melamed Burnout Questionnaire (SMBQ), was incorporated in the original survey which was sent to a random sample of 2500 individuals with a response rate of 76%. After including only actively working people, aged 25-64 years, our study population consisted of 1000 participants (497 women and 503 men). ANOVA and multiple linear regression models were used. Results The prevalence of a high level of burnout (SMBQ >4.0) was 13%. Women had a higher level of burnout than men with the most pronounced difference in the age group 35-44 years. In both sexes the level of burnout decreased with age. Demand and control at work, and job insecurity were related to burnout. In women the level of education, socioeconomic position, work object, and working varying hours were of importance. Interaction effects were found between sex and work object, and sex and working hours. In a multiple regression analysis almost half of the gender difference could be explained by work related and life situational factors. Conclusions Working life conditions contributed to the level of burnout in this actively working sample from the general population in northern Sweden. Especially in women, socioeconomic position was associated with burnout. The high level of burnout in women compared to men was partly explained by more unfavourable working conditions and life situational factors. Efforts to level out gender differences in burnout should probably focus on improving both working

  20. Weather conditions can influence rheumatic diseases.

    PubMed

    Vergés, Josep; Montell, Eulàlia; Tomàs, Elena; Cumelles, Gemma; Castañeda, Guido; Marti, Núria; Möller, Ingrid

    2004-01-01

    In daily clinical practice, many patients attribute joint pain to weather conditions. There is little information published on this subject and most of it is contradictory. The objective of this study was to evaluate the effect of climatic conditions in rheumatic patients. The present work was carried out with patients attending the Instituto Poal de Reumatologia of Barcelona and the data were analyzed by Bioibérica Farma (Spain). It was a prospective, double-blind study including 92 patients with rheumatic disorders (80 with osteoarthritis, 12 with rheumatoid arthritis) compared to a control group of 42 subjects. The evaluation of pain (Huskisson VAS) and functional capacity (Health Assessment Questionnaire, HAQ) were determined daily during one month. The climatic variables studied were temperature, humidity and barometric pressure. The results obtained have been subject to binary regression analysis. Our data demonstrate that osteoarthritic patients experience increased joint pain in response to a decrease in pressure, indicating that low atmospheric pressure conditions exacerbate joint pain in these patients. Our work also suggests that some meteorological variables affect the occurrence of pain in rheumatoid arthritis, since we have found that low temperature increases the risk of joint pain. Therefore, these data suggest that in the future it may be possible to modulate pharmacological and non-pharmacological treatments for some osteoarthritic patients depending on the predictable weather conditions in order to avoid, as much as possible, the disease-associated joint pain and functional incapacity, thus improving patients' quality of life.

  1. Natural and Human Influences on Water Quality in a Shallow Regional Unconsolidated Aquifer, Northern Atlantic Coastal Plain

    USGS Publications Warehouse

    Ator, Scott W.

    2008-01-01

    Data collected from more than 400 wells in the surficial unconfined aquifer in the Northern Atlantic Coastal Plain (New York through North Carolina) were compiled and analyzed to improve understanding of multiple natural and human influences on water quality in such shallow regional aquifers. Geochemical patterns were identified and described through principal components analysis on major ions, and correlation and logistic regression were used to relate observed concentrations of nitrate and selected pesticide compounds (atrazine, metolachlor, simazine, and deethylatrazine, an atrazine degradate) and volatile organic compounds (chloroform, 1,1,1-trichloroethane, tetrachlorethene, and methyl tert-butyl ether) to likely influences, such as observed geochemical patterns, land use, hydrogeology, and soils. Variability in major-ion concentrations is primarily related to ionic strength and redox condition. Concentrations of nitrate, pesticides, and volatile organic compounds are related to natural conditions, as well as the distribution of likely sources reflected in land use. Nitrate is most common in aerobic ground water and in relatively well-drained areas, for example; concentrations greater than 0.4 milligrams per liter may result from a variety of human activities, although concentrations greater than 3 milligrams per liter are more likely in agricultural areas. Atrazine, deethylatrazine, and metolachlor also are related to geochemical patterns, likely because ground-water geochemistry reflects hydrogeologic and soil conditions affecting pesticide transport to the water table. Results demonstrate the value of geochemical information along with the distribution of sources and other influences to understanding the regional occurrence of selected compounds in ground water. Such influences are not unique to the Northern Atlantic Coastal Plain, and thus observations and interpretations are relevant to broader areas.

  2. Relationship between Prevailing Oceanographic conditions on the fishing operations in the Northern Indian Ocean

    NASA Astrophysics Data System (ADS)

    Moazzam Khan, Muhammad

    2014-05-01

    Marked seasonality in fishing operation and catch composition was observed in the Northern Indian Ocean. These variations are more pronounced and noticeable in case of trawling for fish and shrimp as well as in the surface gillnetting for tuna and large pelagics. Although oceanographic conditions of the Northern Indian Ocean has been studied comprehensively, some facets of these are not well understood especially their relation with the fish distribution and abundance. Important oceanographic factors especially migration of oxygen minimum layer towards coastal areas after the cessation of South-West Monsoon seems to the most important factor responsible for the seasonal variation in the fishing intensity and species composition. Distribution and abundance of some of the commercially important marine animals especially billfishes was observed to be associated with the physical features of the area especially their abundance was noticed along continental margin and on the ridges in the Arabian Sea. The paper describes seasonal variation in abundance and catch composition of various fishing operations in the Indian Ocean and relates its to prevailing oceanographic conditions. Fishermen traditional knowledge about the seasonality of these conditions is also documented in the paper.

  3. Relationship between physical condition of the carbonate fraction and sediment environments: northern Puerto Rico shelf

    USGS Publications Warehouse

    Pilkey, O.H.; Fierman, E.I.; Trumbull, J.V.A.

    1979-01-01

    Each of three sediment types recognizable on the northern Puerto Rico shelf and beaches is characterized by calcareous material in different physical condition. Dark terrigenous sand is accumulating at a relatively rapid rate and has a carbonate fraction containing fresh-appearing angular particles. The pure-carbonate skeletal-sand sediment type has a much lower rate of deposition, and its old-appearing calcareous particles have a dull surface luster. The third sediment type, a mixture of the first two, is largely from beaches and is characterized by highly polished, very well-rounded grains. Differences in length of sea-floor exposure and intensity of abrasion appear to be responsible for the variable physical condition of the carbonate fractions. We suggest that on other shelves having less distinctive sedimentary regimes, the physical condition of the carbonate grains could be used to interpret present shelf processes. ?? 1979.

  4. Influences of channelization on discharge of suspended sediment and wetland vegetation in Kushiro Marsh, northern Japan

    NASA Astrophysics Data System (ADS)

    Nakamura, Futoshi; Sudo, Tadashi; Kameyama, Satoshi; Jitsu, Mieko

    1997-03-01

    The effects of wetlands on hydrology, water quality, and wildlife habitat are internationally recognized. Protecting the remaining wetlands is one of the most important environmental issues in many countries. However wetlands in Japan have been gradually shrinking due to agricultural development and urbanization, which generally lowers the groundwater level and introduces suspended sediment and sediment-associated nutrients into wetlands. We examined the influences of channelization on discharge of suspended sediment and wetland vegetation in Hokkaido, northern Japan. The impact of river channelization was confirmed not only by the sediment budgets but also by river aggradation or degradation after the channelization and by the resultant vegetational changes. The budgets of suspended sediment demonstrated that wash load was the predominant component accounting for 95% of the total suspended load delivered into the wetland. This suspended sediment was primarily transported into the wetland by flooding associated with heavy rainfall. Twenty-three percent of the wash load and 63% of the suspended bed material load were deposited in the channelized reach, which produced aggradation of about 2 m at the end of the reach. A shorting of the length of the channel, due to channelization of a meandering river, steepened the slope and enhanced the stream power to transport sediment. This steepening shifted the depositional zones of fine sediment 5 km downstream and aggraded the riverbed. Development of the watershed may increase not only the water discharge but also the amount of suspended sediments. The aggradation reduced the carrying capacity of the channel and caused sediment ladened water to flood over the wetlands. The fine sediment accumulated on the wetlands gradually altered the edaphic conditions and wetland vegetation. A low percentage (10 to 15%) of organic contents of wetlands' soil is more evidence indicating that the present condition is far different from

  5. Estimation of antecedent wetness conditions for flood modelling in northern Morocco

    NASA Astrophysics Data System (ADS)

    Tramblay, Y.; Bouaicha, R.; Brocca, L.; Dorigo, W.; Bouvier, C.; Camici, S.; Servat, E.

    2012-11-01

    In northern Morocco are located most of the dams and reservoirs of the country, while this region is affected by severe rainfall events causing floods. To improve the management of the water regulation structures, there is a need to develop rainfall-runoff models to both maximize the storage capacity and reduce the risks caused by floods. In this study, a model is developed to reproduce the flood events for a 655 km2 catchment located upstream of the 6th largest dam in Morocco. Constrained by data availability, a standard event-based model combining a SCS-CN (Soil Conservation Service Curve Number) loss model and a Clark unit hydrograph was developed for hourly discharge simulation using 16 flood events that occurred between 1984 and 2008. The model was found satisfactory to reproduce the runoff and the temporal evolution of floods, even with limited rainfall data. Several antecedent wetness conditions estimators for the catchment were compared with the initial condition of the model. Theses estimators include an antecedent discharge index, an antecedent precipitation index and a continuous daily soil moisture accounting model (SMA), based on precipitation and evapotranspiration. The SMA model performed the best to estimate the initial conditions of the event-based hydrological model (R2 = 0.9). Its daily output has been compared with ASCAT and AMSR-E remote sensing data products, which were both able to reproduce with accuracy the daily simulated soil moisture dynamics at the catchment scale. This same approach could be implemented in other catchments of this region for operational purposes. The results of this study suggest that remote sensing data are potentially useful to estimate the soil moisture conditions in the case of ungauged catchments in Northern Africa.

  6. Estimation of antecedent wetness conditions for flood modelling in Northern Morocco

    NASA Astrophysics Data System (ADS)

    Tramblay, Y.; Bouaicha, R.; Brocca, L.; Dorigo, W.; Bouvier, C.; Camici, S.; Servat, E.

    2012-08-01

    In Northern Morocco are located most of the dams and reservoirs of the country, while this region is affected by severe rainfall events causing floods. To improve the management of the water regulation structures, there is a need to develop rainfall-runoff models to both maximize the storage capacity and reduce the risks caused by floods. In this study, a model is developed to reproduce the flood events for a 655 km2 catchment located upstream of the 6th largest dam of the Morocco. Constrained by data availability, a standard event-based model was developed for hourly discharge using 16 flood events that occurred between 1984 and 2008. The model was found satisfactory to reproduce the runoff and the temporal evolution of floods, even with limited rainfall data. Several antecedent wetness conditions estimators for the catchment were compared with the initial condition of the model. These estimators include the discharge of the previous days, the antecedent precipitation index and a continuous daily soil moisture accounting model (SMA). The SMA model performed the best to estimate the initial conditions of the model, with R2=0.9. Its daily output has been compared with ASCAT and AMSR-E remote sensing data products, both were able to reproduce with accuracy the daily soil moisture dynamics at the catchment scale. This same approach could be implemented in other catchments of this region for operational purposes. The results of this study indicate the potential usefulness of remote sensing data to estimate the soil moisture conditions in the case of ungauged catchments in Northern Africa.

  7. Garnet lherzolite xenoliths in the kimberlites of northern Lesotho: revised P-T equilibration conditions and upper mantle Palaeogeotherm

    NASA Astrophysics Data System (ADS)

    Carswell, D. A.; Gibb, F. G. F.

    1987-12-01

    Evidence is presented that the inflected palaeogeotherm for northern Lesotho, previously highlighted by Boyd (1973), Boyd and Nixon (1973, 1975), Finnerty and Boyd (1984, 1987), is essentially an artifact of the unsatisfactory, over-simplified barometer formulation (based on MacGregor 1974) employed. The absence of an inflection in the palaeogeotherm for Udachnaya, Siberia based on P-T estimates for garnet lherzolite xenoliths calculated with the same barometer, does not prove the reality of an inflected palaeogeotherm for northern Lesotho. Rather, it reflects, at least in part, chemical differences between the equivalent deformed, high- T xenoliths in these two areas — most importantly expressed in the respective contents of Jadeite relative to ureyite in the constituent orthopyroxenes. Accurate estimation of P-T equilibration conditions for garnet lherzolite xenoliths requires both complete and precise mineral analyses and adequate consideration of the influence of minor elements, such as Cr and Na, on the element exchange reaction thermometers and barometers employed. The barometer formulation of Nickel and Green (1985) is judged to be the best currently available. As no single thermometer is entirely satisfactory and dependable throughout the P-T range of interest, equilibration temperatures are currently best assessed as a mean value obtained from application of the most accurate formulations for both the two-pyroxene solvus thermometer (Bertrand and Mercier 1985) and Fe2+-Mg2+ exchange reactions between garnet-clinopyroxene (Powell 1985), garnet-orthopyroxene (Harley 1984a) and garnet-olivine (O'Neill and Wood 1979) mineral pairs. Such ‘best’ P-T estimates for xenoliths in the kimberlites of northern Lesotho indicate a somewhat elevated, non-inflected, upper mantle palaeogeotherm, compatible with a 120 145 km thick thermally conductive lithosphere above a convecting asthenosphere. The common coarse textured, chemically depleted, garnet lherzolite

  8. Influence of weather-climatic conditions on biospheric processes

    NASA Astrophysics Data System (ADS)

    Govorushko, S. M.

    2012-12-01

    The significance of meteorological processes and phenomena in the biosphere functioning is revealed. The influence of various weather conditions on human health is considered; the factors and mechanisms of their action are described. The impact of meteorological processes on animals is discussed and concrete examples of such impacts are presented. The influence of meteorological processes and phenomena on plants at different stages of their life (pollination, growth, ripening, transport of seeds, damage, and death) and on some abiotic natural components is shown. It is inferred that weather-climatic conditions have a great influence on biospheric processes.

  9. Learning to Coach through Experience: Conditions that Influence Reflection

    ERIC Educational Resources Information Center

    Gilbert, Wade D.; Trudel, Pierre

    2005-01-01

    The goal of the present article is to describe conditions that influence coach reflection, and to provide suggestions for nurturing coach reflection. Coach reflection varies based on the interaction of four conditions: (a) peer access, (b) stage of learning, (c) issue characteristics, and (d) environment. Data are presented to support the four…

  10. Factors influencing marital stability among HIV discordant couples in northern Thailand.

    PubMed

    Tangmunkongvorakul, A; Celentano, D D; Burke, J G; de Boer, M A; Wongpan, P; Suriyanon, V

    1999-10-01

    The burden of HIV in stable relationships places emotional, economic and physical stresses on families. We compared the influence of HIV notification on marital partnerships in northern Thailand among a cohort of HIV discordant couples, and identified factors associated with marital disruption. Data were collected using in-depth interviews with both members of six separated or divorced couples and 13 couples whose relationship remained intact. Five factors influenced marital stability following HIV notification: longer duration of relationship; economic constraints, extended family members' opinions, especially parents; the existence of children from the marriage; and fear of stigmatization by community members. Social influences, both overt and perceived, are important in shaping marital behaviour and decision-making in HIV epidemic areas. HIV counselling needs to be extended beyond the individual seeking testing to include stable partners (and perhaps further, to include the extended family), although it is recognized that this is not the norm for most HIV testing centres.

  11. Latitudinal Discontinuity in Thermal Conditions along the Nearshore of Central-Northern Chile

    PubMed Central

    Tapia, Fabian J.; Largier, John L.; Castillo, Manuel; Wieters, Evie A.; Navarrete, Sergio A.

    2014-01-01

    Over the past decade, evidence of abrupt latitudinal changes in the dynamics, structure and genetic variability of intertidal and subtidal benthic communities along central-northern Chile has been found consistently at 30–32°S. Changes in the advective and thermal environment in nearshore waters have been inferred from ecological patterns, since analyses of in situ physical data have thus far been missing. Here we analyze a unique set of shoreline temperature data, gathered over 4–10 years at 15 sites between 28–35°S, and combine it with satellite-derived winds and sea surface temperatures to investigate the latitudinal transition in nearshore oceanographic conditions suggested by recent ecological studies. Our results show a marked transition in thermal conditions at 30–31°S, superimposed on a broad latitudinal trend, and small-scale structures associated with cape-and-bay topography. The seasonal cycle dominated temperature variability throughout the region, but its relative importance decreased abruptly south of 30–31°S, as variability at synoptic and intra-seasonal scales became more important. The response of shoreline temperatures to meridional wind stress also changed abruptly at the transition, leading to a sharp drop in the occurrence of low-temperature waters at northern sites, and a concurrent decrease in corticated algal biomass. Together, these results suggest a limitation of nitrate availability in nearshore waters north of the transition. The localized alongshore change results from the interaction of latitudinal trends (e.g., wind stress, surface warming, inertial period) with a major headland-bay system (Punta Lengua de Vaca at 30.25°S), which juxtaposes a southern stretch of coast characterized by upwelling with a northern stretch of coast characterized by warm surface waters and stratification. This transition likely generates a number of latitude-dependent controls on ecological processes in the nearshore that can explain species

  12. The impact of oral conditions on children in England, Wales and Northern Ireland 2013.

    PubMed

    Ravaghi, V; Holmes, R D; Steele, J G; Tsakos, G

    2016-08-26

    Background The 2013 Children's Dental Health survey is the fifth in a series of national surveys.Aim To summarise key findings on oral health perceptions, oral symptoms, and the impacts of oral conditions on the daily life of children and their families.Methodology A representative sample of children (aged 5, 8 12 and 15 years) and their parents in England, Wales and Northern Ireland completed relevant questionnaires.Results Oral symptoms, even more profound ones such as toothache, were prevalent among all age groups. Overall, 58% of 12- and 45% of 15-year-olds reported at least one oral impact in the past three months. The most prevalent oral impact was feeling embarrassed to smile or laugh, followed by difficulty eating. These symptoms and oral impacts were disproportionately high among children eligible for free school meals. Furthermore, one fifth to one third of parents reported that their children's oral conditions had some impact on their family life.Conclusion Oral symptoms were common and oral conditions had a negative impact on the quality of life of large proportions of children. There were clear and marked socioeconomic inequalities, with considerably worse oral health perceptions and higher levels of oral impacts among the more deprived children. PMID:27561577

  13. Northern-Hemisphere snow cover patterns and formation conditions in winter 2007 and 2012

    NASA Astrophysics Data System (ADS)

    Cui, Hongyan; Qiao, Fangli; Shu, Qi; Yu, Long

    2016-06-01

    The Arctic sea ice minimum records appeared in the Septembers of 2007 and 2012, followed by high snow cover areas in the Northern Hemisphere winters. The snow cover distributions show different spatial patterns in these two years: increased snow cover in Central Asia and Central North America in 2007, while increased snow cover in East Asia and northwestern Europe in 2012. The high snow cover anomaly shifted to higher latitudes in winter of 2012 compared to 2007. It is noticed that the snow cover had positive anomaly in 2007 and 2012 with the following conditions: the negative geopotential height and the related cyclonic wind anomaly were favorable for upwelling, and, with the above conditions, the low troposphere and surface air temperature anomaly and water vapor anomaly were favorable for the formation and maintenance of snowfalls. The negative geopotential height, cyclonic wind and low air temperature conditions were satisfied in different locations in 2007 and 2012, resulting in different spatial snow cover patterns. The cross section of lower air temperature move to higher latitudes in winter of 2012 compared to 2007.

  14. Ecosystem dynamics of the Pacific-influenced Northern Bering and Chukchi Seas in the Amerasian Arctic

    NASA Astrophysics Data System (ADS)

    Grebmeier, Jacqueline M.; Cooper, Lee W.; Feder, Howard M.; Sirenko, Boris I.

    2006-10-01

    The shallow continental shelves and slope of the Amerasian Arctic are strongly influenced by nutrient-rich Pacific waters advected over the shelves from the northern Bering Sea into the Arctic Ocean. These high-latitude shelf systems are highly productive both as the ice melts and during the open-water period. The duration and extent of seasonal sea ice, seawater temperature and water mass structure are critical controls on water column production, organic carbon cycling and pelagic-benthic coupling. Short food chains and shallow depths are characteristic of high productivity areas in this region, so changes in lower trophic levels can impact higher trophic organisms rapidly, including pelagic- and benthic-feeding marine mammals and seabirds. Subsistence harvesting of many of these animals is locally important for human consumption. The vulnerability of the ecosystem to environmental change is thought to be high, particularly as sea ice extent declines and seawater warms. In this review, we focus on ecosystem dynamics in the northern Bering and Chukchi Seas, with a more limited discussion of the adjoining Pacific-influenced eastern section of the East Siberian Sea and the western section of the Beaufort Sea. Both primary and secondary production are enhanced in specific regions that we discuss here, with the northern Bering and Chukchi Seas sustaining some of the highest water column production and benthic faunal soft-bottom biomass in the world ocean. In addition, these organic carbon-rich Pacific waters are periodically advected into low productivity regions of the nearshore northern Bering, Chukchi and Beaufort Seas off Alaska and sometimes into the East Siberian Sea, all of which have lower productivity on an annual basis. Thus, these near shore areas are intimately tied to nutrients and advected particulate organic carbon from the Pacific influenced Bering Shelf-Anadyr water. Given the short food chains and dependence of many apex predators on sea ice, recent

  15. Maternal body condition influences magnitude of anti-predator response in offspring.

    PubMed

    Bennett, Amanda M; Murray, Dennis L

    2014-11-01

    Organisms exhibit plasticity in response to their environment, but there is large variation even within populations in the expression and magnitude of response. Maternal influence alters offspring survival through size advantages in growth and development. However, the relationship between maternal influence and variation in plasticity in response to predation risk is unknown. We hypothesized that variation in the magnitude of plastic responses between families is at least partly due to maternal provisioning and examined the relationship between maternal condition, egg provisioning and magnitude of plastic response to perceived predation risk (by dragonfly larvae: Aeshna spp.) in northern leopard frogs (Lithobates pipiens). Females in better body condition tended to lay more (clutch size) larger (egg diameter) eggs. Tadpoles responded to predation risk by increasing relative tail depth (morphology) and decreasing activity (behaviour). We found a positive relationship between morphological effect size and maternal condition, but no relationship between behavioural effect size and maternal condition. These novel findings suggest that limitations imposed by maternal condition can constrain phenotypic variation, ultimately influencing the capacity of populations to respond to environmental change. PMID:25253460

  16. Maternal body condition influences magnitude of anti-predator response in offspring

    PubMed Central

    Bennett, Amanda M.; Murray, Dennis L.

    2014-01-01

    Organisms exhibit plasticity in response to their environment, but there is large variation even within populations in the expression and magnitude of response. Maternal influence alters offspring survival through size advantages in growth and development. However, the relationship between maternal influence and variation in plasticity in response to predation risk is unknown. We hypothesized that variation in the magnitude of plastic responses between families is at least partly due to maternal provisioning and examined the relationship between maternal condition, egg provisioning and magnitude of plastic response to perceived predation risk (by dragonfly larvae: Aeshna spp.) in northern leopard frogs (Lithobates pipiens). Females in better body condition tended to lay more (clutch size) larger (egg diameter) eggs. Tadpoles responded to predation risk by increasing relative tail depth (morphology) and decreasing activity (behaviour). We found a positive relationship between morphological effect size and maternal condition, but no relationship between behavioural effect size and maternal condition. These novel findings suggest that limitations imposed by maternal condition can constrain phenotypic variation, ultimately influencing the capacity of populations to respond to environmental change. PMID:25253460

  17. Influence of different wind directions in relation to topography on the outbreak of convection in Northern England

    NASA Astrophysics Data System (ADS)

    Thielen, J.; Gadian, A.

    1996-10-01

    The influence of different wind directions on the outbreak of convection in Northern England, was investigated with a high-resolution numerical model. The Clark model, a 3D finite-difference, non-hydrostatic model was used in this study. It was initialised with the topography of Northern England, a representation of surface characteristics, and used a routinely available meteorological sounding, typical of the unstable conditions. Results showed that convective cells were initially triggered in the lee of the elevated terrain, and that only after the convection had developed, were cells upwind of the elevated terrain produced. The windward slopes themselves seemed sheltered from convection. Under most wind directions, the central Pennines (the Forest of Trawden and the Forest of Rossendale) seemed particularly affected by convective rainfall. Acknowledgements. We gratefully appreciate the on-line DMSP database facility at APL (Newell et al., 1991) from which this study has benefited greatly. We wish to thank E. Friis-Christensen for his encouragement and useful discussions. A. Y. would like to thank the Danish Meteorological Institute, where this work was done, for its hospitality during his stay there and the Nordic Baltic Scholarship Scheme for its financial support of this stay. Topical Editor K.-H. Glassmeier thanks M. J. Engebretson and H. Lühr for their help in evaluating this paper.--> Correspondence to: A. Yahnin-->

  18. Refinement, validation, and application of a benthic condition index for northern Gulf of Mexico estuaries

    USGS Publications Warehouse

    Engle, V.D.; Summers, J.K.

    1999-01-01

    By applying discriminant analysis to benthic macroinvertebrate data, we have developed an indicator of benthic condition for northern Gulf of Mexico estuaries. The data used were collected by the United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) in the Louisianian Province from 1991 to 1994. This benthic index represents a linear combination of the following weighted parameters: the proportion of expected species diversity, the mean abundance of tubificid oligochaetes, the percent of total abundance represented by capitellid polychaetes, the percent of total abundance represented by bivalve mollusks, and the percent of total abundance represented by amphipods. We successfully validated and retrospectively applied the benthic index to all of the benthic data collected by EMAP in the Louisianian Province. This benthic index was also calculated for independent data collected from Pensacola Bay, Florida, in order to demonstrate its flexibility and applicability to different estuarine systems within the same biogeographic region. The benthic index is a useful and valid indicator of estuarine condition that is intended to provide environmental managers with a simple tool for assessing the health of benthic macroinvertebrate communities.

  19. The influence of traditional religion on fertility regulation among the Kassena-Nankana of northern Ghana.

    PubMed

    Adongo, P B; Phillips, J F; Binka, F N

    1998-03-01

    This article presents findings from a study of the influence of traditional religion on reproductive preferences of Kassena-Nankana lineage heads in northern Ghana. Seven reproductive preference questions were administered to nine lineage heads who are primary practitioners of the cult of soothsaying. With the assistance of soothsayers, interviews were repeated in conjunction with the invocation of religious rites in order to determine the views of ancestral spirits on the seven questions. Pairs of lineage head and ancestral interviews are compared to determine the role of traditional religion in shaping male reproductive preferences. Interview pairs reflect a shared preference for sons, large compounds, and a growing lineage. Findings nonetheless show that some ancestral spirits want small families, some even wanting fewer children than corresponding lineage heads. Spiritual consultations are nondogmatic and open to external ideas and influences, suggesting that family planning introduction will not encounter systematic religious opposition among the Kassena-Nankana. PMID:9561667

  20. The influence of traditional religion on fertility regulation among the Kassena-Nankana of northern Ghana.

    PubMed

    Adongo, P B; Phillips, J F; Binka, F N

    1998-03-01

    This article presents findings from a study of the influence of traditional religion on reproductive preferences of Kassena-Nankana lineage heads in northern Ghana. Seven reproductive preference questions were administered to nine lineage heads who are primary practitioners of the cult of soothsaying. With the assistance of soothsayers, interviews were repeated in conjunction with the invocation of religious rites in order to determine the views of ancestral spirits on the seven questions. Pairs of lineage head and ancestral interviews are compared to determine the role of traditional religion in shaping male reproductive preferences. Interview pairs reflect a shared preference for sons, large compounds, and a growing lineage. Findings nonetheless show that some ancestral spirits want small families, some even wanting fewer children than corresponding lineage heads. Spiritual consultations are nondogmatic and open to external ideas and influences, suggesting that family planning introduction will not encounter systematic religious opposition among the Kassena-Nankana.

  1. Influencing and Facilitating Conditions for Developing Reflective Assessment Practice

    ERIC Educational Resources Information Center

    Rønsen, Anne Kristin; Smith, Kari

    2014-01-01

    By following a professional development project focusing on enhancing assessment competence amongst teachers, the current study examines how teachers use reflective writing and systematic discussions as tools for developing competence in assessment. More specifically, the article aims at identifying conditions that influence and facilitate…

  2. DISTRIBUTION AND COMPOSITION OF DISSOLVED AND PARTICULATE ORGANIC CARBON IN NORTHERN SAN FRANCISCO BAY DURING LOW FRESHWATER FLOW CONDITIONS

    EPA Science Inventory

    The distribution of dissolved and particulate organic matter was studied in northern San Francisco Bay on seven dates during declining flow conditions from April to October 1996. Measurements were made at 3 to 11 stations (usually 8) along the salinity gradient from the Sacrament...

  3. Population dynamics of a northern-adapted mammal: disentangling the influence of predation and climate change.

    PubMed

    Pokallus, John W; Pauli, Jonathan N

    2015-09-01

    Community structure and interspecific interactions are particularly vulnerable to rapidly changing climatic regimes. Recent changes in both climate and vertebrate community assemblages have created a unique opportunity to examine the impacts of two dynamic forces on population regulation. We examined the effects of warming winter conditions and the reestablishment of a previously extirpated predator, the fisher (Martes pennanti), on regulatory mechanisms in a northern-adapted mammal, the porcupine (Erethizon dorsatum), along their southern range boundary. Using a long-term (17-year) capture-recapture data set, we (1) quantified the impacts of climate change and increased fisher predation on the survival of adult porcupines at their regional southern terminus, (2) assessed recruitment (via both adult fecundity and juvenile survival) of porcupines, and (3) modeled the relative importance of predation and winter conditions on the demography and population growth rate (λ). Severe winters and abundant predators interacted synergistically to reduce adult survivorship by as much as 44%, while expanding predator populations led to near reproductive failure among porcupines. Increasing predatory pressure, disruptions in this community module, and more frequent extreme winter weather events led to predicted extirpation within 50 years, whereas in the absence of predators, the population was viable. Our results provide a mechanistic understanding behind distributional shifts resulting from climate change and may be broadly relevant for predicting future distributional shifts in other northern-adapted mammalian species.

  4. Population dynamics of a northern-adapted mammal: disentangling the influence of predation and climate change.

    PubMed

    Pokallus, John W; Pauli, Jonathan N

    2015-09-01

    Community structure and interspecific interactions are particularly vulnerable to rapidly changing climatic regimes. Recent changes in both climate and vertebrate community assemblages have created a unique opportunity to examine the impacts of two dynamic forces on population regulation. We examined the effects of warming winter conditions and the reestablishment of a previously extirpated predator, the fisher (Martes pennanti), on regulatory mechanisms in a northern-adapted mammal, the porcupine (Erethizon dorsatum), along their southern range boundary. Using a long-term (17-year) capture-recapture data set, we (1) quantified the impacts of climate change and increased fisher predation on the survival of adult porcupines at their regional southern terminus, (2) assessed recruitment (via both adult fecundity and juvenile survival) of porcupines, and (3) modeled the relative importance of predation and winter conditions on the demography and population growth rate (λ). Severe winters and abundant predators interacted synergistically to reduce adult survivorship by as much as 44%, while expanding predator populations led to near reproductive failure among porcupines. Increasing predatory pressure, disruptions in this community module, and more frequent extreme winter weather events led to predicted extirpation within 50 years, whereas in the absence of predators, the population was viable. Our results provide a mechanistic understanding behind distributional shifts resulting from climate change and may be broadly relevant for predicting future distributional shifts in other northern-adapted mammalian species. PMID:26552263

  5. Body condition and pregnancy in northern Yellowstone elk: evidence for predation risk effects?

    PubMed

    White, P J; Garrott, Robert A; Hamlin, Kenneth L; Cook, Rachel C; Cook, John G; Cunningham, Julie A

    2011-01-01

    S. Creel et al. reported a negative correlation between fecal progesterone concentrations and elk:wolf ratios in greater Yellowstone elk (Cervus elaphus) herds and interpreted this correlation as evidence that pregnancy rates of elk decreased substantially in the presence of wolves (Canis lupus). Apparently, the hypothesized mechanism is that decreased forage intake reduces body condition and either results in elk failing to conceive during the autumn rut or elk losing the fetus during winter. We tested this hypothesis by comparing age-specific body condition (percentage ingesta-free body fat) and pregnancy rates for northern Yellowstone elk, one of the herds sampled by Creel et al., before (1962-1968) and after (2000-2006) wolf restoration using indices developed and calibrated for Rocky Mountain elk. Mean age-adjusted percentage body fat of female elk was similarly high in both periods (9.0%-0.9% pre-wolf; 8.9%-0.8% post-wolf). Estimated pregnancy rates (proportion of females that were pregnant) were 0.91 pre-wolf and 0.87 post-wolf for 4-9 year-old elk (95% CI on difference = -0.15 to 0.03, P = 0.46) and 0.64 pre-wolf and 0.78 post-wolf for elk > 9 years old (95% CI on difference = -0.01 to 0.27, P = 0.06). Thus, there was little evidence in these data to support strong effects of wolf presence on elk pregnancy. We caution that multiple lines of evidence and/or strong validation should be brought to bear before relying on indirect measures of how predators affect pregnancy rates. PMID:21516883

  6. Variations in glacial and interglacial marine conditions over the last two glacial cycles off northern Greenland

    NASA Astrophysics Data System (ADS)

    Löwemark, Ludvig; Chao, Weng-Si; Gyllencreutz, Richard; Hanebuth, Till J. J.; Chiu, Pin-Yao; Yang, Tien-Nan; Su, Chih-Chieh; Chuang, Chih-Kai; León Dominguez, Dora Carolina; Jakobsson, Martin

    2016-09-01

    Five sediment cores from the Lomonosov Ridge and the Morris Jesup Rise north of Greenland show the history of sea-ice coverage and primary productivity over the last two glacial cycles. Variations in Manganese content, benthic and planktonic foraminifera, bioturbation, and trace fossil diversity are interpreted to reflect differences in sea-ice cover and sediment depositional conditions between the identified interglacials. Marine Isotope Stage (MIS) 1 and MIS 2 are represented by thin (<<5 cm) sediment units while the preceding interglacial MIS 5 and glacial MIS 6 are characterized by thick (10-20 cm) deposits. Foraminiferal abundances and bioturbation suggest that MIS 1 was generally characterized by severe sea-ice conditions north of Greenland while MIS 5 appears to have been considerably warmer with more open water, higher primary productivity, and higher sedimentation rates. Strengthened flow of Atlantic water along the northern continental shelf of Greenland rather than development of local polynyas is here suggested as a likely cause for the relatively warmer marine conditions during MIS 5 compared to MIS 1. The cores also suggest distinct differences between the glacial intervals MIS 2 and MIS 6. While MIS 6 is distinguished by a relatively thick sediment unit poor in foraminifera and with low Mn values, MIS 2 is practically missing. We speculate that this could be the effect from a paleocrystic sea-ice cover north of Greenland during MIS 2 that prevented sediment delivery from sea ice and icebergs. In contrast, the thick sequence deposited during MIS 6 indicates a longer glacial period with dynamic intervals characterized by huge drifting icebergs delivering ice rafted debris (IRD). A drastic shift from thinner sedimentary cycles where interglacial sediment parameters indicate more severe sea-ice conditions gave way to larger amplitude cycles with more open water indicators was observed around the boundary between MIS 7/8. This shift is in agreement with a

  7. Decadal variation of the Northern Hemisphere Annular Mode and its influence on the East Asian trough

    NASA Astrophysics Data System (ADS)

    Lu, Chunhui; Zhou, Botao; Ding, Yihui

    2016-06-01

    We analyze the decadal variation of the stratosphere-troposphere coupled system around the year 2000 by using the NCEP reanalysis-2 data. Specifically, the relationship between the Northern Hemisphere Annular Mode (NAM) and the tropospheric East Asian trough is investigated in order to find the effective stratospheric signals during cold air outbreaks in China. Statistical analyses and dynamic diagnoses both indicate that after 2000, increased stratospheric polar vortex disturbances occur and the NAM is mainly in negative phase. The tropospheric polar areas are directly affected by the polar vortex, and in the midlatitudes, the Ural blocking high and East Asian trough are more active, which lead to enhanced cold air activities in eastern and northern China. Further investigation reveals that under this circulation pattern, downward propagations of negative NAM index are closely related to the intensity variation of the East Asian trough. When negative NAM anomalies propagate down to the upper troposphere and reach a certain intensity (standardized NAM index less than-1), they result in apparent reinforcement of the East Asian trough, which reaches its maximum intensity about one week later. The northerly wind behind the trough transports cold air southward and eastward, and the range of influence and the intensity are closely associated with the trough location. Therefore, the NAM index can be used as a measure of the signals from the disturbed stratosphere to give some indication of cold air activities in China.

  8. The influence of shrub canopies on soil temperatures across northern Canada

    NASA Astrophysics Data System (ADS)

    Myers-Smith, Isla; Lévesque, Esther; Grogan, Paul; Lantz, Trevor

    2013-04-01

    Shrub species are the largest plant life form in tundra ecosystems; therefore, changes in the abundance of shrubs will likely create feedbacks to influence biodiversity, ecosystem function and climate. Shrub canopies have been hypothesized to influence ground temperatures by trapping snow in winter and shading soils in summer. However, generalizable relationships have yet to be identified among species, soil types and regions. We present data from seven shrub tundra sites in the Yukon, Northwest Territories and Northern Quebec. Summer soil temperatures were often cooler under shrub canopies; however, there was no clear relationship with canopy height. In contrast, we found a significant positive relationship between canopy height and winter soil temperatures. The difference in the minimum winter soil temperatures at 5 cm depth under shrub versus open tundra was ~1°C greater for every additional 10cm of canopy height, despite differences in air temperatures, snow pack, soil characteristics and species composition between sites. Our results highlight the important influence of canopy cover on soil temperatures. By combining data in this manner across regions, we will be able to better estimate the relative magnitude of positive and negative feedbacks of shrub increases to climate warming and thus will improve estimates of future vegetation change and permafrost stability.

  9. Ecology of cultivable yeasts in pristine forests in northern Patagonia (Argentina) influenced by different environmental factors.

    PubMed

    Mestre, María Cecilia; Fontenla, Sonia; Rosa, Carlos A

    2014-06-01

    Environmental factors influencing the occurrence and community structure of soil yeasts in forests are not well studied. There are few studies dedicated to Southern Hemisphere soil yeasts populations and even fewer focused on temperate forests influenced by volcanic activity. The present work aimed to study the ecology of soil yeast communities from pristine forests influenced by different environmental factors (precipitation, physicochemical properties of soil, tree species, soil region, and season). The survey was performed in 4 northern Patagonian forests: 2 dominated by Nothofagus pumilio and 2 by Nothofagus antarctica. Yeast communities were described with ecological indices and species accumulation curves, and their association with environmental characteristics was assessed using multivariate analysis. Each forest site showed a particular arrangement of species as a result of environmental characteristics, such as dominant plant species, nutrient availability, and climatic characteristics. Cryptococcus podzolicus was most frequently isolated in nutrient-rich soils, Trichosporon porosum dominated cold mountain forests with low nutrient and water availability in soil, and capsulated yeasts such as Cryptococcus phenolicus dominated forest sites with low precipitation. The present work suggests that environmental factors affecting yeast communities may not be the current soil characteristics but the result of complex interactions of factors including natural disturbances like volcanic activity.

  10. Exploring the Influence of Topography on Seismicity Patterns in the Northern Chile Andes

    NASA Astrophysics Data System (ADS)

    Shrivastava, M. N.; Gonzalez, G.; Moreno, M.

    2014-12-01

    The high topographic of the Andes has been resulted from the long-lasting and ongoing convergence between Nazca and South America plates. The build-up of the high topographic Andes does not only have reduced the convergent rate in the long-term but may have also influenced the short-term patterns of seismicity. The high mountains and the west flank of the Northern Chile is experiencing shallow and deep seismicity, with notable along-strike variations. Motivated by these considerations, we integrate modeling of Gravitational Potential Energy (GPE) and Global Positioning System (GPS) observations to investigate the control of the topography on the seismicity distribution. In this attempt, it is hypothesized that shallow seismicity is strongly influenced by the GPE in the range per unit area (1.45 -1.66) x1014 N/m due to high topography. By calculating the deviatoric stress associated with GPE and strain rate from GPS velocities, we obtain depth integrated value of stress for the full thickness of the lithosphere and the state of the stress in the upper crust and seismogenic plate contact. The GPE field in combination with GPS derived strain rates are used to sketch the present deformation pattern in the northern Chile Andes in regard of the crustal seismicity. The results indicate that high GPE gradient exhibits significant relationships with the shallow earthquake activity in the region. Therefore region of large topographic, where earthquakes have not occurred in past years, may be considered as potentially seismic hazards. Therefore high GPE gradient factors should be considered in the studies of earthquake activity and seismic hazard estimation.

  11. Environmental conditions influence tissue regeneration rates in scleractinian corals.

    PubMed

    Sabine, Alexis M; Smith, Tyler B; Williams, Dana E; Brandt, Marilyn E

    2015-06-15

    Natural and anthropogenic factors may influence corals' ability to recover from partial mortality. To examine how environmental conditions affect lesion healing, we assessed several water quality parameters and tissue regeneration rates in corals at six reefs around St. Thomas, US Virgin Islands. We hypothesized that sites closer to developed areas would have poor water quality due to proximity to anthropogenic stresses, which would impede tissue regeneration. We found that water flow and turbidity most strongly influenced lesion recovery rates. The most impacted site, with high turbidity and low flow, recovered almost three times slower than the least impacted site, with low turbidity, high flow, and low levels of anthropogenic disturbance. Our results illustrate that in addition to lesion-specific factors known to affect tissue regeneration, environmental conditions can also control corals' healing rates. Resource managers can use this information to protect low-flow, turbid nearshore reefs by minimizing sources of anthropogenic stress.

  12. Study of factors influencing the germination of Apera spica-venti(L.) P. Beauv. in controlled conditions.

    PubMed

    Morales, W R Meza; Vanbellinghen, C; Bodson, B; Henriet, F

    2013-01-01

    Apera spica-venti (L.) P. Beauv. is a common weed of cereal crops widely spread in Northern and Eastern Europe, Northern Asia, Siberia and Canada. Given the ability of Apera spica-venti to grow and develop in Wallonia and lack of scientific knowledge of its biology, germination tests were performed on four populations. These laboratory tests were carried on according to the standards of the International Seed Testing Association (ISTA) in order to study three key factors (composition of water solution, presence/absence of pre-chilling and temperature) influencing the germination of the seeds. Germination tests showed that a solution containing 2 g/L of KNO3 and alternating night/day temperatures between 10 degrees C and 30 degrees C favorably influence the germination of Apera spica-venti. These results in controlled conditions are a premise for greenhouse and field tests.

  13. Working in hot conditions--a study of electrical utility workers in the northern territory of Australia.

    PubMed

    Brearley, Matt; Harrington, Phillip; Lee, Doug; Taylor, Raymond

    2015-01-01

    Environmental conditions of Australia's Northern Territory are seasonally conducive to excessive body heat storage by outdoor workers. For electrical utility workers who periodically work at height, in confined space, and in proximity to live power sources, the impact of the climate may be considered a hazardous condition. Therefore, this study examined the physiological and fluid balance responses of 20 power network workers (31.5 years; 86.0 kg; 1.71 m; BMI 29.5) throughout work shifts in the Northern and Southern regions of the Northern Territory, Australia. Twenty male heat-acclimatized power network workers provided written informed consent to be monitored during maintenance of electrical infrastructure that included replacing power pole components and transformer and substation repairs in the Northern (n = 13) and Southern regions (n = 7) of the Northern Territory (mean wet-bulb globe temperatures of 32.0°C and 28.7°C, respectively). An ingestible telemetry pill provided measurement of gastrointestinal temperature (Tgi), that when combined with heart rate values, provided physiological strain index (PSI). Urine specific gravity, sweat rate, and level of dehydration were also determined. The Tgi values of this study were within the ISO9886 limit for monitored, heat-acclimatized workers, with a peak of 38.4°C. Mean PSI was 2.6, which represents overall low strain, with periods of moderate strain. Urinary analysis indicated that workers were dehydrated prior to and following the work shift, however the mean sweat rate of 0.44 L.h(-1) was matched by fluid consumption of 0.42 L.h(-1) to limit body mass loss to 0.1% during the shift. This study demonstrates that heat acclimatized electrical utility workers adhere to ISO9886 requirements when undertaking self-paced activity in hot conditions.

  14. Working in hot conditions--a study of electrical utility workers in the northern territory of Australia.

    PubMed

    Brearley, Matt; Harrington, Phillip; Lee, Doug; Taylor, Raymond

    2015-01-01

    Environmental conditions of Australia's Northern Territory are seasonally conducive to excessive body heat storage by outdoor workers. For electrical utility workers who periodically work at height, in confined space, and in proximity to live power sources, the impact of the climate may be considered a hazardous condition. Therefore, this study examined the physiological and fluid balance responses of 20 power network workers (31.5 years; 86.0 kg; 1.71 m; BMI 29.5) throughout work shifts in the Northern and Southern regions of the Northern Territory, Australia. Twenty male heat-acclimatized power network workers provided written informed consent to be monitored during maintenance of electrical infrastructure that included replacing power pole components and transformer and substation repairs in the Northern (n = 13) and Southern regions (n = 7) of the Northern Territory (mean wet-bulb globe temperatures of 32.0°C and 28.7°C, respectively). An ingestible telemetry pill provided measurement of gastrointestinal temperature (Tgi), that when combined with heart rate values, provided physiological strain index (PSI). Urine specific gravity, sweat rate, and level of dehydration were also determined. The Tgi values of this study were within the ISO9886 limit for monitored, heat-acclimatized workers, with a peak of 38.4°C. Mean PSI was 2.6, which represents overall low strain, with periods of moderate strain. Urinary analysis indicated that workers were dehydrated prior to and following the work shift, however the mean sweat rate of 0.44 L.h(-1) was matched by fluid consumption of 0.42 L.h(-1) to limit body mass loss to 0.1% during the shift. This study demonstrates that heat acclimatized electrical utility workers adhere to ISO9886 requirements when undertaking self-paced activity in hot conditions. PMID:25265189

  15. 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.

  16. Characterizing the parent and alkyl polycyclic aromatic hydrocarbons in the Pearl River Estuary, Daya Bay and northern South China Sea: influence of riverine input.

    PubMed

    Yuan, Ke; Wang, Xiaowei; Lin, Li; Zou, Shichun; Li, Yan; Yang, Qingshu; Luan, Tiangang

    2015-04-01

    Distributions of 31 parent polycyclic aromatic hydrocarbons (PAHs) and 29 alkyl PAHs in surface sediments of the Pearl River Estuary (PRE), Daya Bay (DYB) and northern South China Sea (SCS) were examined to study the influence of riverine input. It was found that the contributions of riverine input to sediment PAHs in PRE was much higher than other areas. However, higher proportion of alkyl PAHs and low molecular weight PAHs in DYB and the northern SCS was observed, indicating their different sources. Nevertheless, the sediment PAHs in PRE were heterogeneous and affected by the hydrodynamic conditions. The high molecular weight PAHs were dominant in PRE and enriched in the depositional area of suspended particular matter (SPM). Moreover, the concentration of PAHs in SPM was similar to those in surface sediments and dominated in water columns. Therefore, SPM played a very important role in transportation and distribution of PAHs in PRE.

  17. Influence of Medical Representatives on Prescribing Practices in Mekelle, Northern Ethiopia

    PubMed Central

    Workneh, Birhanu Demeke; Gebrehiwot, Mehari Gebregergis; Bayo, Tigist Assefa; Gidey, Meles Tekie; Belay, Yared Belete; Tesfaye, Desalegn Mergiaw; Kassa, Terefe Teshome

    2016-01-01

    Background Drug promotion by medical representatives is one of the factors that influence physicians’ prescribing decisions and choice of drugs. Objective To assess the influence of medical representatives on prescribing practice of physicians in health facilities, Mekelle, Northern Ethiopia. Materials and Methods Facility-based cross-sectional study was conducted enrolling all physicians working in public and private health facilities. All public and private health facilities were included and similarly, all physicians rendering services in these facilities were sampled in the study. The data were collected from February to March, 2015. Data were then entered into Epidata Version 3.1 and transferred to STATA version 12 for analysis. Both bivariable and multivariable logistic regressions were used to determine predictors. Results Of the ninety physicians approached in this study, 40 (48.2%) of the physicians believed that their prescribing decisions were influenced by visits of medical representatives (MRs). The odds of physicians who received gifts from MRs being influenced to prescribe their respective products was six times higher than those who reported not accepting any gifts [AOR = 6.56, 95% CI: 2.25, 19.13]. Stationery materials 23(35.4%) and drug samples 20(54.2%) were the commonest kinds of gifts given to physicians and face to face talking 45(54.2%) was the most frequent promotional methods. The finding of this study showed that around thirty-nine percent of MRs have had negative attitude toward competitors’ product. Moreover, working in private health facility was also another predictor of influence of prescribing decision in the study area [AOR = 12.78, 95% CI: 1.31, 124.56]. Conclusion Nearly half of the physicians working in Mekelle reported that their prescribing decisions were influenced by MRs in the last 12 months. Accepting gifts and working in private health facilities were predictors of influencing prescribing decisions. However, most MRs

  18. Influence of a local source of DDT pollution on statewide DDT residues in waterfowl wings, northern Alabama, 1978-79

    USGS Publications Warehouse

    Fleming, W.J.; O'Shea, T.J.

    1980-01-01

    Heavy DDT contamination resulting from a former DDT manufacturing plant in northern Alabama has influenced statewide averages of DDT, DDE, and TDE residues in duck wings tested in the National Pesticide Monitoring Program. In states where contaminant levels in duck wings are high, residue analyses of wings categorized by finer geographic subdivision may be useful in defining the areas of heaviest contamination.

  19. Influence of a local source of DDT pollution on statewide DDT residues in waterfowl wings, northern Alabama, 1978-79.

    PubMed

    Fleming, W J; O'Shea, T J

    1980-12-01

    Heavy DDT contamination resulting from a former DDT manufacturing plant in northern Alabama has influenced statewide averages of DDT, DDE, and TDE residues in duck wings tested in the National Pesticide Monitoring Program. In states where contaminant levels in duck wings are high, residue analyses of wings categorized by finer geographic subdivision may be useful in defining the areas of heaviest contamination.

  20. The influence of rainfall, vegetation, elephants and people on fire frequency of miombo woodlands, northern Mozambique

    NASA Astrophysics Data System (ADS)

    Ribeiro, N. S.; Okin, G. S.; Shugart, H.; Swap, R.

    2007-12-01

    Miombo woodlands are important in southern Africa as they occupy over 50% of the land and, their good and services support a large proportion of people in the region. Anthropogenic fires occur in miombo every year especially in the dry season (May - October). This study explores the influence of annual rainfall, elephant density, human density and corridors, and vegetation on the fire frequency. It was carried out in Niassa Reserve located in northern Mozambique, the largest and more pristine conservation area of miombo woodlands in the world. We used a time series analysis and statistical t-test of MODIS-derived Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) to explore the relationship between biomass and fire frequency. The influence of rainfall, elephants, people and vegetation on fire return was explored using a stepwise logistic regression analysis. The results of this study indicate that fire frequency is higher in places with high biomass at beginning of the dry season. In these areas fire seems to be more intense and to strongly reduce biomass in the late dry season. Land cover is the strongest predictor of fire frequency, but elephant density, annual rainfall and human corridors are also important.

  1. The Influence of Rainfall, Vegetation, Elephants and People on Fire Frequency of Miombo Woodlands, Northern Mozambique

    NASA Astrophysics Data System (ADS)

    Ribeiro, N. S.; Okin, G. S.; Shugart, H. H.; Swap, R. J.

    2008-12-01

    Miombo woodlands are important in southern Africa as they occupy over 50% of the land and, their good and services support a large proportion of people in the region. Anthropogenic fires occur in miombo every year especially in the dry season (May - October). This study explores the influence of annual rainfall, elephant density, human density and corridors, and vegetation on the fire frequency. It was carried out in Niassa Reserve located in northern Mozambique, the largest and more pristine conservation area of miombo woodlands in the world. We used a time series analysis and statistical t-test of MODIS-derived Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) to explore the relationship between biomass and fire frequency. The influence of rainfall, elephants, people and vegetation on fire return was explored using a stepwise logistic regression analysis. The results of this study indicate that fire frequency is higher in places with high biomass at beginning of the dry season. In these areas fire seems to be more intense and to strongly reduce biomass in the late dry season. Land cover is the strongest predictor of fire frequency, but elephant density, annual rainfall and human corridors are also important.

  2. A case study of the synoptic patterns influencing midwinter snowmelt across the northern Great Plains

    NASA Astrophysics Data System (ADS)

    Grundstein, Andrew J.; Leathers, Daniel J.

    1998-12-01

    Snow cover is found across extensive areas of the northern hemisphere during the winter and early spring seasons. Meltwater provided by this snow cover can be an important source of freshwater for agriculture, domestic uses and hydroelectric power. Rapid ablation of the snowpack, however, can also pose environmental hazards such as flooding.The ability to forecast meltwater quantities is dependent upon a knowledge of the factors influencing the snowmelt process. This paper employs a hybrid modelling and synoptic climatological approach to investigate the relationships between synoptic weather patterns, surface energy fluxes and midwinter snowmelt in the northern Great Plains. The first objective of this study is to identify distinct synoptic patterns that are associated with days where significant snow cover ablation occurred. The second objective is to evaluate the relationships between synoptic-scale weather patterns, snow surface energy transfers and snowmelt. A case study of 21 February 1975 is used to illustrate these relationships. Unlike the other synoptic-type studies, which rely on empirically derived energy flux data from single index sites, this study employs a physically based snowpack model to generate estimates of energy fluxes. The use of modelled fluxes instead of measured values allows for a more spatially extensive analysis as surface fluxes over the entire study region can be analysed in conjunction with the prevailing synoptic-scale weather patterns.Three major synoptic types, characterized by the presence of a midlatitude cyclone, are associated with large midwinter snowmelt episodes in the northern Great Plains. The case study illustrates how variations in temperature, humidity, cloud cover and wind speeds associated with such cyclonic storms can play a major role in affecting snow surface-atmosphere energy exchanges. As expected, elevated wind speeds and stronger temperature and humidity gradients significantly increased the transfers of

  3. Conditions for Viral Influence Spreading through Multiplex Correlated Social Networks

    NASA Astrophysics Data System (ADS)

    Hu, Yanqing; Havlin, Shlomo; Makse, Hernán A.

    2014-04-01

    A fundamental problem in network science is to predict how certain individuals are able to initiate new networks to spring up "new ideas." Frequently, these changes in trends are triggered by a few innovators who rapidly impose their ideas through "viral" influence spreading, producing cascades of followers and fragmenting an old network to create a new one. Typical examples include the rise of scientific ideas or abrupt changes in social media, like the rise of Facebook to the detriment of Myspace. How this process arises in practice has not been conclusively demonstrated. Here, we show that a condition for sustaining a viral spreading process is the existence of a multiplex-correlated graph with hidden "influence links." Analytical solutions predict percolation-phase transitions, either abrupt or continuous, where networks are disintegrated through viral cascades of followers, as in empirical data. Our modeling predicts the strict conditions to sustain a large viral spreading via a scaling form of the local correlation function between multilayers, which we also confirm empirically. Ultimately, the theory predicts the conditions for viral cascading in a large class of multiplex networks ranging from social to financial systems and markets.

  4. Adverse environmental conditions influence age-related innate immune responsiveness

    PubMed Central

    May, Linda; van den Biggelaar, Anita HJ; van Bodegom, David; Meij, Hans J; de Craen, Anton JM; Amankwa, Joseph; Frölich, Marijke; Kuningas, Maris; Westendorp, Rudi GJ

    2009-01-01

    Background- The innate immune system plays an important role in the recognition and induction of protective responses against infectious pathogens, whilst there is increasing evidence for a role in mediating chronic inflammatory diseases at older age. Despite indications that environmental conditions can influence the senescence process of the adaptive immune system, it is not known whether the same holds true for the innate immune system. Therefore we studied whether age-related innate immune responses are similar or differ between populations living under very diverse environmental conditions. Methods- We compared cross-sectional age-related changes in ex vivo innate cytokine responses in a population living under affluent conditions in the Netherlands (age 20–68 years old, n = 304) and a population living under adverse environmental conditions in Ghana (age 23–95 years old, n = 562). Results- We found a significant decrease in LPS-induced Interleukin (IL)-10 and Tumor Necrosis Factor (TNF) production with age in the Dutch population. In Ghana a similar age-related decline in IL-10 responses to LPS, as well as to zymosan, or LPS plus zymosan, was observed. TNF production, however, did not show an age-associated decline, but increased significantly with age in response to co-stimulation with LPS and zymosan. Conclusion- We conclude that the decline in innate cytokine responses is an intrinsic ageing phenomenon, while pathogen exposure and/or selective survival drive pro-inflammatory responses under adverse living conditions. PMID:19480711

  5. Ecological Condition of Streams in Northern Nevada EPA R-MAP Humboldt Basin Project

    EPA Science Inventory

    This report presents stream data on the Humboldt River Basin in northern Nevada using the R-EMAP Program. Water is of primary importance to both the economy and the ecology of the region. Many of the waters of Nevada have previously received relatively little attention in regar...

  6. Saltier sea surface water conditions recorded by multiple mid-Holocene corals in the northern South China Sea

    NASA Astrophysics Data System (ADS)

    Guo, Yangrui; Deng, Wenfeng; Chen, Xuefei; Wei, Gangjian; Yu, Kefu; Zhao, Jian-xin

    2016-08-01

    The typical features of the mid-Holocene can be used to better understand present-day climate conditions and the potential trends of future climate change. The surface conditions, including sea surface temperature (SST) and sea surface salinity (SSS), of the South China Sea (SCS) are largely controlled by the East Asian monsoon system. Surface water conditions reconstructed from coral proxies can be used to study the evolution of the East Asian monsoon during the mid-Holocene. However, there are some discrepancies among existing coral-based studies regarding whether the mid-Holocene sea surface water was much saltier than the present day surface waters. Based on paired Sr/Ca and δ18O of modern and three fossil corals, this paper reconstructs the patterns of seasonal variation in SSS during the mid-Holocene in the northern SCS. The Δδ18O records (a proxy for SSS) derived from the three fossil corals were all heavier than that from the modern coral, which suggests the presence of more saline surface waters during the mid-Holocene in the northern SCS. These results are consistent with previous studies based on records reconstructed from coral and foraminifera, as well as from numerical simulations. Reduced rainfall caused by the strengthened Asian Monsoon and/or the northward shift of the intertropical convergence zone during the mid-Holocene would explain the increased salinity of the surface waters of the northern SCS. The findings presented here clarify the discrepancies among previous studies and confirm the existence of saltier surface waters in the northern SCS during the mid-Holocene.

  7. Late Cenozoic deep weathering patterns on the Fennoscandian shield in northern Finland: A window on ice sheet bed conditions at the onset of Northern Hemisphere glaciation

    NASA Astrophysics Data System (ADS)

    Hall, Adrian M.; Sarala, Pertti; Ebert, Karin

    2015-10-01

    The nature of the regolith that existed on the shields of the Northern Hemisphere at the onset of ice sheet glaciation is poorly constrained. In this paper, we provide the first detailed account of an exceptionally preserved, deeply weathered late Neogene landscape in the ice sheet divide zone in northern Finland. We mine data sets of drilling and pitting records gathered by the Geological Survey of Finland to reconstruct regional preglacial deep weathering patterns within a GIS framework. Using a large geochemical data set, we give standardised descriptions of saprolite geochemistry using a variant of the Weathering Index of Parker (WIP) as a proxy to assess the intensity of weathering. We also focus on mineral prospects and mines with dense pit and borehole data coverage in order to identify links between geology, topography, and weathering. Geology is closely linked to topography on the preglacial shield landscape of northern Finland and both factors influence weathering patterns. Upstanding, resistant granulite, granite, gabbro, metabasalt, and quartzite rocks were associated with fresh rock outcrops, including tors, or with thin (< 5 m) grusses. Plains developed across less resistant biotite gneisses, greenstones, and belts of alternating rock types were mainly weathered to thick (10-20 m) grusses with WIPfines values above 3000 and 4000. Beneath valley floors developed along mineralised shear and fracture zones, weathering penetrated locally to depths of > 50 m and included intensely weathered kaolinitic clays with WIPfines values below 1000. Late Neogene weathering profiles were varied in character. Tripartite clay-gruss-saprock profiles occur only in limited areas. Bipartite gruss-saprock profiles were widespread, with saprock thicknesses of > 10 m. Weathering profiles included two discontinuities in texture, materials and resistance to erosion, between saprolite and saprock and between saprock and rock. Limited core recovery when drilling below the soil

  8. Thermal structure and melting conditions associated with `hot' subduction: Implications from thermobarometry of Garibaldi belt basalts, northern Cascadia Subduction System

    NASA Astrophysics Data System (ADS)

    Green, N. L.

    2005-12-01

    The northern Cascadia margin of North America is the classic example of a "hot" subduction system. The downgoing Juan de Fuca plate decreases in age from ca. 10 m.y. off the central Washington coast to less than 5 m.y. off central Vancouver Island; beneath the Garibaldi volcanic belt (GVB) 250 km east of the convergent margin, inferred age of the oceanic lithosphere decreases northward from ca. 22 m.y to 13 m.y. Primitive and near-primitive mafic lavas, which primarily occur trenchward of the GVB volcanic front, range northward from high-Al olivine tholeiites, Mg-andesites and LILE- and LREE-enriched calc-alkaline basalts at Glacier Peak, through transitional basalts in the Cheakamus Valley to alkali olivine basalts and trachybasalts at Meager Mountain, Salal Glacier and Bridge River. The more northerly GVB basaltic magmas show the least evidence of slab-derived components in their source regions. Application of various olivine-melt and pyroxene-melt thermobarometers to GVB basalts indicates a general increase in magmatic temperatures from 1150-1200 C in Mount Baker and Glacier Peak basalts to 1225-1300 C in Bridge River and Salal Glacier lavas. Fe-Ti oxide thermobarometry suggests that northernmost basalts equilibrated under oxygen fugacities conditions between QFM and NNO, whereas Glacier Peak lavas equilibrated at higher oxygen fugacities (ca. 1 log unit above NNO). Estimated P and T conditions of mantle segregation suggest that GVB basalts ascended from increasingly greater depths northward along the volcanic arc. Similar variation is indicated by calculated P-T of basalt equilibrations with both Mg- and Fe-rich peridotite mineral assemblages, based on diopside and albite activity-composition relations. Estimated mantle equilibration temperatures correlate positively with some HFSE abundances (e.g., Hf), but negatively with those of fluid mobile elements (e.g., Cs and B). These relationships are considered in terms of the influence of slab thermal structure on

  9. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    SciTech Connect

    Wallace, Wesley K.; Hanks, Catherine L.; Whalen, Michael T.; Jensen1, Jerry; Shackleton, J. Ryan; Jadamec, Margarete A.; McGee, Michelle M.; Karpov1, Alexandre V.

    2001-07-23

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively underformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding on fracture patterns, (3) The influence of deformation on fluid flow, and (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics.

  10. Landscape Changes Influence the Occurrence of the Melioidosis Bacterium Burkholderia pseudomallei in Soil in Northern Australia

    PubMed Central

    Kaestli, Mirjam; Mayo, Mark; Harrington, Glenda; Ward, Linda; Watt, Felicity; Hill, Jason V.; Cheng, Allen C.; Currie, Bart J.

    2009-01-01

    Background The soil-dwelling saprophyte bacterium Burkholderia pseudomallei is the cause of melioidosis, a severe disease of humans and animals in southeast Asia and northern Australia. Despite the detection of B. pseudomallei in various soil and water samples from endemic areas, the environmental habitat of B. pseudomallei remains unclear. Methodology/Principal Findings We performed a large survey in the Darwin area in tropical Australia and screened 809 soil samples for the presence of these bacteria. B. pseudomallei were detected by using a recently developed and validated protocol involving soil DNA extraction and real-time PCR targeting the B. pseudomallei–specific Type III Secretion System TTS1 gene cluster. Statistical analyses such as multivariable cluster logistic regression and principal component analysis were performed to assess the association of B. pseudomallei with environmental factors. The combination of factors describing the habitat of B. pseudomallei differed between undisturbed sites and environmentally manipulated areas. At undisturbed sites, the occurrence of B. pseudomallei was found to be significantly associated with areas rich in grasses, whereas at environmentally disturbed sites, B. pseudomallei was associated with the presence of livestock animals, lower soil pH and different combinations of soil texture and colour. Conclusions/Significance This study contributes to the elucidation of environmental factors influencing the occurrence of B. pseudomallei and raises concerns that B. pseudomallei may spread due to changes in land use. PMID:19156200

  11. Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals

    PubMed Central

    Peterson, Sarah H.; Ackerman, Joshua T.; Costa, Daniel P.

    2015-01-01

    Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200–1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions of the northeast Pacific Ocean. We coupled satellite telemetry, diving behaviour and stable isotopes (carbon and nitrogen) from 77 adult females, and showed that variability among individuals in foraging location, diving depth and δ13C values were correlated with mercury concentrations in blood and muscle. We identified three clusters of foraging strategies, and these resulted in substantially different mercury concentrations: (i) deeper-diving and offshore-foraging seals had the greatest mercury concentrations, (ii) shallower-diving and offshore-foraging seals had intermediate levels, and (iii) coastal and more northerly foraging seals had the lowest mercury concentrations. Additionally, mercury concentrations were lower at the end of the seven-month-long foraging trip (n = 31) than after the two-month- long post-breeding trip (n = 46). Our results indicate that foraging behaviour influences mercury exposure and mesopelagic predators foraging in the northeast Pacific Ocean may be at high risk for mercury bioaccumulation. PMID:26085591

  12. Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals.

    PubMed

    Peterson, Sarah H; Ackerman, Joshua T; Costa, Daniel P

    2015-07-01

    Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200-1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions of the northeast Pacific Ocean. We coupled satellite telemetry, diving behaviour and stable isotopes (carbon and nitrogen) from 77 adult females, and showed that variability among individuals in foraging location, diving depth and δ(13)C values were correlated with mercury concentrations in blood and muscle. We identified three clusters of foraging strategies, and these resulted in substantially different mercury concentrations: (i) deeper-diving and offshore-foraging seals had the greatest mercury concentrations, (ii) shallower-diving and offshore-foraging seals had intermediate levels, and (iii) coastal and more northerly foraging seals had the lowest mercury concentrations. Additionally, mercury concentrations were lower at the end of the seven-month-long foraging trip (n = 31) than after the two-month- long post-breeding trip (n = 46). Our results indicate that foraging behaviour influences mercury exposure and mesopelagic predators foraging in the northeast Pacific Ocean may be at high risk for mercury bioaccumulation.

  13. Female hormone influences on sexual assaults in Northern Ireland from 2002 to 2009.

    PubMed

    Beirne, Patricia; Hall, Janet; Grills, Claire; Moore, Tara

    2011-10-01

    In Northern Ireland 1 in every 454 women of 13 years and over during 2008/09 reported to police that they had suffered a sexual assault. This study considered the possibility that women may be more likely to be victims of sexual assault during the fertile phase of their reproductive cycle. Evolutionary psychology suggests that women would have suffered more negative consequences if sexually assaulted when fertile and that specific psychological mechanisms may have evolved in women to combat male coercion. Female behaviours towards men vary across the reproductive cycle and men's behaviour towards women may vary also as a result of changes in female hormones. Hormones play a major role in producing the characteristic cyclical changes throughout a woman's reproductive life. This study is the first study of female hormone influences on sexual assaults. The data for the study was collated retrospectively from the records of 105 females with regular, spontaneous menstrual cycles. These females alleged recent sexual assault and were examined in Belfast during the period 2002-2009. The study concluded that young girls in the middle of their cycle, i.e. the fertile phase, were most at risk of sexual assault. It is possible that both sexes are sensitive to signs, albeit subtle behavioural signs, indicating high risk of conception. PMID:21907935

  14. Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals.

    PubMed

    Peterson, Sarah H; Ackerman, Joshua T; Costa, Daniel P

    2015-07-01

    Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200-1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions of the northeast Pacific Ocean. We coupled satellite telemetry, diving behaviour and stable isotopes (carbon and nitrogen) from 77 adult females, and showed that variability among individuals in foraging location, diving depth and δ(13)C values were correlated with mercury concentrations in blood and muscle. We identified three clusters of foraging strategies, and these resulted in substantially different mercury concentrations: (i) deeper-diving and offshore-foraging seals had the greatest mercury concentrations, (ii) shallower-diving and offshore-foraging seals had intermediate levels, and (iii) coastal and more northerly foraging seals had the lowest mercury concentrations. Additionally, mercury concentrations were lower at the end of the seven-month-long foraging trip (n = 31) than after the two-month- long post-breeding trip (n = 46). Our results indicate that foraging behaviour influences mercury exposure and mesopelagic predators foraging in the northeast Pacific Ocean may be at high risk for mercury bioaccumulation. PMID:26085591

  15. Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals

    USGS Publications Warehouse

    Peterson, Sarah H.; Ackerman, Joshua T.; Costa, Daniel P.

    2015-01-01

    Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200–1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions of the northeast Pacific Ocean. We coupled satellite telemetry, diving behaviour and stable isotopes (carbon and nitrogen) from 77 adult females, and showed that variability among individuals in foraging location, diving depth and δ13C values were correlated with mercury concentrations in blood and muscle. We identified three clusters of foraging strategies, and these resulted in substantially different mercury concentrations: (i) deeper-diving and offshore-foraging seals had the greatest mercury concentrations, (ii) shallower-diving and offshore-foraging seals had intermediate levels, and (iii) coastal and more northerly foraging seals had the lowest mercury concentrations. Additionally, mercury concentrations were lower at the end of the seven-month-long foraging trip (n = 31) than after the two-month- long post-breeding trip (n = 46). Our results indicate that foraging behaviour influences mercury exposure and mesopelagic predators foraging in the northeast Pacific Ocean may be at high risk for mercury bioaccumulation.

  16. Behavioural Responses to Thermal Conditions Affect Seasonal Mass Change in a Heat-Sensitive Northern Ungulate

    PubMed Central

    van Beest, Floris M.; Milner, Jos M.

    2013-01-01

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

  17. Hunting influences the diel patterns in habitat selection by northern pintails Anas acuta

    USGS Publications Warehouse

    Casazza, Michael L.; Coates, Peter S.; Miller, Michael R.; Overton, Cory T.; Yparraguirre, Daniel R.

    2012-01-01

    Northern pintail Anas acuta (hereafter pintail) populations wintering within Suisun Marsh, a large estuarine managed wetland near San Francisco Bay, California,USA, have declined markedly over the last four decades. The reasons for this decline are unclear. Information on how hunting and other factors influence the selection of vegetation types and sanctuaries would be beneficial to manage pintail populations in SuisunMarsh. During 1991-1993, we radio-marked and relocated female pintails (individuals: N = 203, relocations: N = 7,688) within Suisun Marsh to investigate habitat selection during the non-breeding months (winter). We calculated selection ratios for different vegetation types and for sanctuaries, and examined differences in those ratios between hunting season (i.e. hunting and non-hunting), age (hatchyear and after-hatch-year), and time of day (daylight or night hours). We found that diel patterns in selection were influenced by hunting disturbance. For example, prior to the hunting season and during daylight hours, pintails selected areas dominated by brass buttons Cotula coronopifolia, a potentially important food source, usually outside of sanctuary boundaries. However, during the hunting season, pintails did not select brass buttons during daylight hours, but instead highly selected permanent pools, mostly within sanctuaries. Also, during the hunting season, pintails showed strong selection for brass buttons at night. Sanctuaries provided more area of permanent water pools than within hunting areas and appeared to function as important refugia during daylight hours of the hunting season. Wildlife managers should encourage large protected permanent pools adjacent to hunted wetlands to increase pintail numbers within wetland environments and responsibly benefit hunting opportunities while improving pintail conservation.

  18. Phytoplankton community structure and dynamics in the river influenced margin of the Northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Chakraborty, S.; Lohrenz, S. E.

    2010-12-01

    Coastal ocean margins especially those which are dominated by large river systems such as the Mississippi River are characterized by high variability in fluxes of both organic and inorganic matter. The current lack of reliable estimates of carbon fluxes in large river systems contributes to uncertainties in global carbon fluxes. Autotrophic (photosynthesis) and heterotrophic (respiration) processes strongly influence carbon fluxes in river-dominated coastal margins and are dependent on the phytoplankton community structure, community composition. Knowledge of the functional specialization of the planktonic community structure is critical in understanding biogeochemical cycling in these ecosystems. As a part of the GulfCarbon program and associated projects funded through NSF, NASA and NOAA, we examined the the composition and biomass of the phytoplankton community in northern Gulf of Mexico coastal waters influenced by the Mississippi River. Taxonomic composition, size indices and biomass of phytoplankton community were determined along several cross-shelf transects. A cross-shelf gradient of in chlorophyll-a was consistently observed in association with low salinity water masses related to freshwater inputs from the Mississippi River and other rivers. Shifts in phytoplankton community spatially were found to be associated with the salinity gradient along the shelf waters. Seasonal differences were also observed and were closely related to the river discharge and nutrient dynamics. Extensive, quality controlled data sets such as these will help to better understand the effects of plankton community on the seawater pCO2 variations and to refine regional carbon fluxes and contributions of coastal waters to the global carbon budget.

  19. Pressure-temperature conditions in granulite facies rocks of the northern Canadian Shield, Arctic Canada

    SciTech Connect

    Frisch, T.

    1985-01-01

    The northernmost part of the Churchill Structural Province of the Canadian Shield, underlying 60,000 km/sup 2/ of southeastern Ellesmere Island, Coburg Island and eastern Devon Island, consists of granulite facies metasedimentary, meta-igneous and plutonic intrusive rocks 2400 to 1900 m.y. old. Garnet+pyroxene+plagioclase of quartzofeldspathic gneisses from Ellesmere and Coburg islands indicate pressures, at 750/sup 0/C, ranging from greater than or equal to 6 to approx. 4kb; the lower pressures are derived largely, but not solely, from rim compositions. Similar rocks from Devon Island consistently indicate higher pressures of 6 to 7 kb. Garnet and plagioclase cores in sillimanite+cordierite-rich pelitic gneisses give pressures between 5 and 6.5 kb at 750/sup 0/C, the highest pressures being found in Devon Island rocks. Orthopyroxene+cordierite symplectites around garnet in magnesian metapelites indicate pressures under 4 kb at 650/sup 0/C. All cordierite is clearly of retrograde origin, having formed as a result of decompression during uplift, but even the highest pressures determined fall below the stability limit of cordierite in metapelites. Circumstantial evidence exists for the former stable coexistence of orthopyroxene+sillimanite, which would attest to pressures well in excess of 7 kb, but existing geobarometric equilibria have been strongly influenced by retrograde processes. Retrograde pressure-temperature conditions may well predominate in many granulite terranes but are not always recognized due to a scarcity of suitable mineral assemblages.

  20. Earthworm species influence on carbon-mineral association in a sugar maple forest in northern Minnesota

    NASA Astrophysics Data System (ADS)

    Lyttle, A.; Yoo, K.; Aufdenkampe, A. K.; Hale, C. M.; Sebestyen, S. D.

    2011-12-01

    Non-native European earthworms are invading previously earthworm-free hardwood forests in the northern Great Lakes Region. Whereas earthworms' impacts on soil morphology and geochemical properties have been well documented in agricultural settings, the role of earthworms in biogeochemical cycles of undisturbed forests remains poorly understood. The forest soils that were recently invaded by exotic earthworms, therefore, provide a unique opportunity to understand how and how much earthworms contribute to biogeochemistry of non-agricultural environments. Increased degree and extent of soil mixing is one of the better known consequences of the earthworm invasion. Our hypothesis is that invasive earthworms positively affect carbon (C) stabilization by enhancing contacts between organic matter and minerals. We are studying C-mineral complexation along a well-established earthworm chronosequence in a sugar maple forest in northern Minnesota. We have observed changes in total earthworm biomass, A horizon C storage, and total specific surface area (SSA) of minerals as the invasion progresses. Because each earthworm species has different feeding and dwelling habits, biogeochemical imprints of the invasion reflect not only earthworms' biomass but also their species composition. All earthworm species show an increase in their biomass with greater time length since the invasion, though epigeic earthworms tend to be the pioneer species. As the total earthworm biomass increases, we find greater incorporation of organic C into the A horizon; the O horizon thickness decreases from 8 to 0 cm as the A horizon thickens from ~5 cm to ~12 cm. While leaf litter biomass is negatively correlated with total earthworm biomass, dramatic decreases in litter biomass are coupled with considerable increases in the biomass of epi-endogeic species. Despite the general decrease in C storage in the A horizon with greater degree of invasion, the storages fluctuate along the transect because

  1. Influence of support conditions and temperature on the EMI characteristics

    NASA Astrophysics Data System (ADS)

    Stancalie, A.; Sporea, D.; Malinowski, P.; Mieloszyk, M.; Opoka, S.; Wandowski, T.; Ostachowicz, W.

    2015-07-01

    The present work reports results from an extensive set of measurements which has been performed in order to formulate standard method to remove temperature changes from impedance measurements. The other issue addressed here is the investigation of influence of boundary condition and temperature changes on electromechanical impedance measurement for structural member. Due to electromechanical coupling, changes in dynamic characteristics can be seen in electrical impedance of piezoelectric transducer. Two different systems have been used during this measurement process. System based on FBG sensors has been used for temperature changes measurement while PZT transducers mounted on the structure with impedance analyser were used for electrical parameters measurement. During research electrical impedance and resistance of piezoelectric transducer were measured in order to analyze changes in amplitude of peaks and the frequency shift of peaks due to temperature variations and different configurations of the beam.

  2. Influence of overconsolidated condition on permeability evolution in silica sand

    NASA Astrophysics Data System (ADS)

    Kimura, S.; Kaneko, H.; Ito, T.; Nishimura, O.; Minagawa, H.

    2013-12-01

    Permeability of sediments is important factors for production of natural gas from natural gas hydrate bearing layers. Methane-hydrate is regarded as one of the potential resources of natural gas. As results of coring and logging, the existence of a large amount of methane-hydrate is estimated in the Nankai Trough, offshore central Japan, where many folds and faults have been observed. In the present study, we investigate the permeability of silica sand specimen forming the artificial fault zone after large displacement shear in the ring-shear test under two different normal consolidated and overconsolidated conditions. The significant influence of overconsolidation ratio (OCR) on permeability evolution is not found. The permeability reduction is influenced a great deal by the magnitude of normal stress during large displacement shearing. The grain size distribution and structure observation in the shear zone of specimen after shearing at each normal stress level are analyzed by laser scattering type particle analyzer and scanning electron microscope, respectively. It is indicated that the grain size and porosity reduction due to the particle crushing are the factor of the permeability reduction. This study is financially supported by METI and Research Consortium for Methane Hydrate Resources in Japan (the MH21 Research Consortium).

  3. Low impact of dry conditions on the CO2 exchange of a Northern-Norwegian blanket bog

    NASA Astrophysics Data System (ADS)

    Lund, Magnus; Bjerke, J. W.; Drake, B. G.; Engelsen, O.; Hansen, G. H.; Parmentier, F. J. W.; Powell, T. L.; Silvennoinen, H.; Sottocornola, M.; Tømmervik, H.; Weldon, S.; Rasse, D. P.

    2015-02-01

    Northern peatlands hold large amounts of organic carbon (C) in their soils and are as such important in a climate change context. Blanket bogs, i.e. nutrient-poor peatlands restricted to maritime climates, may be extra vulnerable to global warming since they require a positive water balance to sustain their moss dominated vegetation and C sink functioning. This study presents a 4.5 year record of land-atmosphere carbon dioxide (CO2) exchange from the Andøya blanket bog in northern Norway. Compared with other peatlands, the Andøya peatland exhibited low flux rates, related to the low productivity of the dominating moss and lichen communities and the maritime settings that attenuated seasonal temperature variations. It was observed that under periods of high vapour pressure deficit, net ecosystem exchange was reduced, which was mainly caused by a decrease in gross primary production. However, no persistent effects of dry conditions on the CO2 exchange dynamics were observed, indicating that under present conditions and within the range of observed meteorological conditions the Andøya blanket bog retained its C uptake function. Continued monitoring of these ecosystem types is essential in order to detect possible effects of a changing climate.

  4. Growth conditions influence melanization of Brazilian clinical Sporothrix schenckii isolates.

    PubMed

    Almeida-Paes, Rodrigo; Frases, Susana; Fialho Monteiro, Paulo Cezar; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria; Nosanchuk, Joshua D

    2009-04-01

    Sporothrix schenckii is known to produce DHN melanin on both conidial and yeast cells, however little information is available regarding the factors inducing fungal melanization. We evaluated whether culture conditions influenced melanization of 25 Brazilian S. schenckii strains and one control strain (ATCC 10212). Tested conditions included different media, pH, temperature, incubation time, glucose concentrations, and presence or absence of tricyclazole or L-DOPA. Melanization was reduced on Sabouraud compared to defined chemical medium. The majority of strains produced small amounts of melanin at 37 degrees C and none melanized at basic pH. Increased glucose concentrations did not inhibit melanization, rather increasing glucose enhanced pigment production in 27% of strains. Melanin synthesis was also enhanced by the addition of L-DOPA and its addition to medium with tricyclazole, an inhibitor of melanin synthesis, resulted in fungal melanization, including hyphal melanin production. Our results suggest that different S. schenckii strains have distinct control of melanization and that this fungus can use phenolic compounds to enhance melanization in vitro.

  5. Growth conditions influence melanization of Brazilian clinical Sporothrix schenckii isolates

    PubMed Central

    Almeida-Paes, Rodrigo; Frases, Susana; Monteiro, Paulo Cezar Fialho; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria; Nosanchuk, Joshua D.

    2009-01-01

    Sporothrix schenckii is known to produce DHN melanin on both conidial and yeast cells, however little information is available regarding the factors inducing fungal melanization. We evaluated whether culture conditions influenced melanization of 25 Brazilian S. schenckii strains and one control strain (ATCC 10212). Tested conditions included different media, pH, temperature, incubation time, glucose concentrations, and presence or absence of tricyclazole or L-DOPA. Melanization was reduced on Sabouraud compared to defined chemical medium. The majority of strains produced small amounts of melanin at 37°C and none melanized at basic pH. Increased glucose concentrations did not inhibit melanization, rather increasing glucose enhanced pigment production in 27% of strains. Melanin synthesis was also enhanced by the addition of L-DOPA and its addition to medium with tricyclazole, an inhibitor of melanin synthesis, resulted in fungal melanization, including hyphal melanin production. Our results suggest that different S. schenckii strains have distinct control of melanization and that this fungus can use phenolic compounds to enhance melanization in vitro. PMID:19328867

  6. Asymmetry and nonlinearity of the influence of ENSO on the northern winter stratosphere: 1. Observations

    NASA Astrophysics Data System (ADS)

    Rao, Jian; Ren, Rongcai

    2016-08-01

    The El Niño-Southern Oscillation (ENSO) has significant effects on the extratropical stratosphere. This study explores the nonlinearity and the asymmetry of these influences by distinguishing the different effects of four types of ENSO: "moderate El Niño," "strong El Niño," "moderate La Niña," and "strong La Niña." It is revealed that the moderate El Niño and the strong La Niña are much more efficient than the strong El Niño and the moderate La Niña, respectively, in modulating the northern winter stratospheric variability, resulting in significant nonlinearity and asymmetry. The tropical rainfall anomalies induced by a moderate El Niño or a strong La Niña are centered over the central equatorial Pacific region near the dateline, while the convection responses to a strong El Niño or a moderate La Niña are centered farther eastward. Accordingly, the anomalous Pacific-North America wave train pattern is modulated by ENSO in a nonlinear and asymmetric way, which leads to the large nonlinear and asymmetric components of the vertical Eliassen-Palm (E-P) flux responses to ENSO. The increase of planetary wave activity in the extratropical stratosphere in moderate El Niño winters is thus greater than in strong El Niño winters, whereas a strong La Niña gives a larger decrease in propagation than a moderate La Niña. The relatively strong (weak) E-P flux responses to moderate (strong), El Niño and strong (moderate) La Niña explains the remarkable nonlinearity and asymmetry in the response of the extratropical stratosphere to ENSO.

  7. The Influence of Fluvial Discharge on Pelagic Production in the Gulf of Papua, Northern Coral Sea

    NASA Astrophysics Data System (ADS)

    Robertson, A. I.; Dixon, P.; Alongi, D. M.

    1998-03-01

    The influence of river discharge on the behaviour of dissolved and particulate nutrients, and patterns of primary and bacterial production, were investigated in the Gulf of Papua, northern Coral Sea. Inshore, close to the mouths of the Fly and Purari Rivers, buoyant plumes of warmer river water, marked by high total suspended solid concentrations and floating plant debris, overlay cooler saline waters, and their movement with the tides results in marked short-term changes in salinity profiles. Mixing of silicate was conservative, but the behaviour of other nutrients (nitrate, DOC, phosphate) indicated biological uptake and/or production and release from particles. DIN:DIP ratios increased slightly into the gulf indicating possible phosphorus limitation to phytoplankton growth in mid-shelf and outer-shelf waters. At the mouth of the Fly Delta and in inshore waters, decreases in phosphate concentration corresponded to increases in standing stocks of chlorophyll a. Primary production rates were <20 mgC m -2day -1in waters of salinity <4, but ranged from 133 to 942 mgC m -2day -1in river delta and inshore waters. Bacterial production was highly variable (range: 162-886 mgC m -2day -1), but correlated very significantly ( r=0·97) with primary production. Rates of bacterioplankton production nearly equal or exceed primary production rates, indicating that pelagic bacteria in the gulf are utilizing other carbon sources (e.g. riverine DOC and POC) and that gulf waters are net heterotrophic. The pattern of primary production across the estuary—shelf salinity gradient off the southern Papua New Guinea coast is similar to that observed off the Amazon. However, the much lower volume of water exiting the Papuan rivers restricts maximum production to the inshore (<50 km from the coast) rim of the Gulf of Papua. This pattern is mirrored in benthic secondary production indicating close benthic-pelagic coupling.

  8. Influence of Spanwise Boundary Conditions on Slat Noise Simulations

    NASA Technical Reports Server (NTRS)

    Lockard, David P.; Choudhari, Meelan M.; Buning, Pieter G.

    2015-01-01

    The slat noise from the 30P/30N high-lift system is being investigated through computational fluid dynamics simulations with the OVERFLOW code in conjunction with a Ffowcs Williams-Hawkings acoustics solver. In the present study, two different spanwise grids are being used to investigate the effect of the spanwise extent and periodicity on the near-field unsteady structures and radiated noise. The baseline grid with periodic boundary conditions has a short span equal to 1/9th of the stowed chord, whereas the other, longer span grid adds stretched grids on both sides of the core, baseline grid to allow inviscid surface boundary conditions at both ends. The results indicate that the near-field mean statistics obtained using the two grids are similar to each other, as are the directivity and spectral shapes of the radiated noise. However, periodicity forces all acoustic waves with less than one wavelength across the span to be two-dimensional, without any variation in the span. The spanwise coherence of the acoustic waves is what is needed to make estimates of the noise that would be radiated from realistic span lengths. Simulations with periodic conditions need spans of at least six slat chords to allow spanwise variation in the low-frequencies associated with the peak of broadband slat noise. Even then, the full influence of the periodicity is unclear, so employing grids with a fine, central region and highly stretched meshes that go to slip walls may be a more efficient means of capturing the spanwise decorrelation of low-frequency acoustic phenomena.

  9. Factors influencing the food choices and eating habits of restaurant chefs in northern New Jersey: a pilot study.

    PubMed

    Mahadevan, Meena; Feldman, Charles

    2011-01-01

    This study was conducted to understand the factors influencing the food habits of restaurant chefs in northern New Jersey. Data was collected from participants (N = 12) using dietary recalls, and semi-structured interviews based on the socio-ecological model. Dietary recall analysis revealed multiple nutritional intake hazards including skipping meals, and substitution of foods rich in fats and sugar for fruits and vegetables, and increased consumption of alcohol. Qualitative data analysis revealed that their food habits were influenced by a repertoire of individual, organizational, and interpersonal factors. The relevance of these findings to nutrition intervention programs for this population is discussed. PMID:21888589

  10. Watershed land use influences on river discharge and channel characteristics across northern New Jersey

    NASA Astrophysics Data System (ADS)

    Galster, J. C.; Palmer, K.; Birrer, M.; Espinosa, S.; Pope, G. A.; Feng, H.; Wu, M. S.

    2012-12-01

    River characteristics such as sediment size, channel dimensions, and discharges can be strongly controlled by watershed land use. This project investigated three watersheds in northern New Jersey with varying degrees of forested, agriculture, and urban land uses to determine the effects of land use on these rivers. The watersheds are the Flatbrook, the Wallkill, and the Rockaway rivers and are predominantly forested, forested/agricultural, and forested/urban respectively. Eight sites across these fourth and fifth-order watersheds were investigated including: 1) the grain size using the Wolman pebble count method, 2) channel dimensions (slope, width, depth) with a total station, and 3) channel stability using the rapid geomorphic assessment (RGA). Channel width changes from 1930 to present were determined using historic aerial photographs, and river discharge characteristics were compiled using custom software to determine the flashiness (as measured by the Reynolds-Baker Index) and the Baseflow Index. The three adjacent watersheds have minimal variations in potential confounding variables such as watershed slope, climate, and precipitation, allowing for the isolation of the effects of land use changes. While some of the general relationship between how land use changes affect rivers (e.g., urban streams typically have larger grain sizes and flashier discharges), studies such as this one are important in determining how rivers respond locally. Across the studied watersheds, forested land uses are positively associated with rapid geomorphic assessments scores, indicating the influence of upstream land use and the importance of vegetation. Forested land use is also associated with efficient discharges as measured by hydraulic radius, although there were not significant changes in channel width from 1930 to present. The flashiness of all rivers has increased over time while the baseflow index has decreased, which may be a climatic signal as opposed to being influenced

  11. Physical Conditions Associated with Widespread Seafloor Methane Discharge on the Northern US Atlantic Margin

    NASA Astrophysics Data System (ADS)

    Skarke, A. D.; Ruppel, C. D.; Brothers, D. S.

    2014-12-01

    Recent analysis of water column backscatter data and remotely operated vehicle (ROV) video imagery collected by NOAA Ship Okeanos Explorer between 2011 and 2013 revealed methane discharge from the seafloor at over 570 gas seep locations along the northern US Atlantic margin. To the best of our knowledge, such large-scale seepage has not previously been observed on a passive margin outside the Arctic or not spatially associated with a petroleum basin. This seepage has implications for the global carbon cycle, ocean chemistry (e.g., acidification), and in some cases, the climate system. Using data collected by Okeanos Explorer and NOAA's Deep Discoverer ROV, we combine water column backscatter data with video imagery and seafloor backscatter data to estimate gas flux and constrain the geoacoustic properties of the seabed at methane discharge sites. The total methane flux from the northern US Atlantic margin seeps is conservatively estimated at ~15-90 Mg y-1, based on observations of gas bubble volume, discharge rates, and discharge points per site. However, fewer than 1% of the identified seep sites have been inspected with a ROV, and this estimate is likely to be revised upward as the characteristics of the seeps are further constrained. Another important observation to emerge from our analysis is the lack of spatial correlation between seep sites and the ~5000 pockmarks mapped on the northern part of the US Atlantic margin. In this region, pockmarks, which are often easily identified by geophysical imaging of the seafloor, should not be considered potential target sites for finding undiscovered areas of seepage. Conversely, discrete patches of elevated relative seafloor acoustic backscatter amplitude do appear to be correlated with the spatial distribution of methane seeps, implying anomalous seafloor characteristic at seep loci. This finding is consistent with ROV video observations of authigenic carbonate outcrops and extensive chemosynthetic bivalve communities

  12. Historical Influences on Contemporary Tobacco Use by Northern Plains and Southwestern American Indians

    PubMed Central

    2016-01-01

    There are great differences in smoking- and tobacco-related mortality between American Indians on the Northern Plains and those in the Southwest that are best explained by (1) ecological differences between the two regions, including the relative inaccessibility and aridity of the Southwest and the lack of buffalo, and (2) differences between French and Spanish Indian relations policies. The consequence was the disruption of inter- and intratribal relations on the Northern Plains, where as a response to disruption the calumet (pipe) ceremony became widespread, whereas it did not in the Southwest. Tobacco was, thus, integrated into social relationships with religious sanctions on the Northern Plains, which increased the acceptability of commercial cigarettes in the 20th century. Smoking is, therefore, more deeply embedded in religious practices and social relationships on the Northern Plains than in the Southwest. PMID:26691134

  13. Historical Influences on Contemporary Tobacco Use by Northern Plains and Southwestern American Indians.

    PubMed

    Kunitz, Stephen J

    2016-02-01

    There are great differences in smoking- and tobacco-related mortality between American Indians on the Northern Plains and those in the Southwest that are best explained by (1) ecological differences between the two regions, including the relative inaccessibility and aridity of the Southwest and the lack of buffalo, and (2) differences between French and Spanish Indian relations policies. The consequence was the disruption of inter- and intratribal relations on the Northern Plains, where as a response to disruption the calumet (pipe) ceremony became widespread, whereas it did not in the Southwest. Tobacco was, thus, integrated into social relationships with religious sanctions on the Northern Plains, which increased the acceptability of commercial cigarettes in the 20th century. Smoking is, therefore, more deeply embedded in religious practices and social relationships on the Northern Plains than in the Southwest. PMID:26691134

  14. Evaluation of sampling strategies to characterize dissolved oxygen conditions in northern Gulf of Mexico estuaries

    SciTech Connect

    Summers, J.K.; Engle, V.D.

    1993-01-01

    Dissolved oxygen was continuously monitored in eight sites of northern Gulf of Mexico estuaries in August, 1990. Monte Carlo analyses on subsamples of the data were used to evaluate several commonly used monitoring strategies. Monitoring strategies which involve single point sampling of dissolved oxygen may often misclassify an estuary as having good water quality. In the case of shallow, often well-mixed estuaries that experience diurnal cycles, such monitoring often does not occur at night, during the time of lowest dissolved oxygen concentration. The authors' objective was to determine the minimum sampling effort required to correctly classify a site in terms of the observed frequency of hypoxia. Tests concluded that the most successful classification strategy used the minimum dissolved oxygen concentration from a continuously sampled 24-hour period. (Copyright (c) 199e Kluwer Academic Publishers.)

  15. Evaluation of sampling strategies to characterize dissolved oxygen conditions in northern Gulf of Mexico estuaries.

    PubMed

    Summers, J K; Engle, V D

    1993-02-01

    Dissolved oxygen was continuously monitored in eight sites of northern Gulf of Mexico estuaries in August, 1990. Monte Carlo analyses on subsamples of the data were used to evaluate several commonly used monitoring strategies. Monitoring strategies which involve single point sampling of dissolved oxygen may often misclassify an estuary as having good water quality. In the case of shallow, often well-mixed estuaries that experience diurnal cycles, such monitoring often does not occur at night, during the time of lowest dissolved oxygen concentration. Our objective was to determine the minimum sampling effort required to correctly classify a site in terms of the observed frequency of hypoxia. Tests concluded that the most successful classification strategy used the minimum dissolved oxygen concentration from a continuously sampled 24-hour period.

  16. Coexistence of ionospheric positive and negative storm phases under northern winter conditions: A case study

    NASA Astrophysics Data System (ADS)

    Lu, G.; Richmond, A. D.; Roble, R. G.; Emery, B. A.

    2001-11-01

    The response of the thermosphere and ionosphere to the famous January 10, 1997, geomagnetic storm is simulated using the thermosphere-ionosphere-electrodynamics general circulation model with realistic, time-dependent distributions of ionospheric convection and auroral precipitation as inputs. The simulation results show a dominant positive storm phase of increased F layer electron density over much of the northern winter hemisphere, but a negative storm phase with reduced electron density at middle and low latitudes is also evident in the simulation. The coexistence of both positive and negative storm phases is a result of the complex dynamical and chemical interactions between charged particles and neutral gases. The impulsive magnetospheric energy inputs via auroral precipitation and Joule heating generate traveling atmospheric and ionospheric disturbances (TADs and TIDs) which propagate from the northern auroral zone to lower latitudes and penetrate well into the Southern Hemisphere. The simulation results demonstrate that positive storm phases are caused primarily by enhanced auroral precipitation over high latitudes and by TIDs at middle and low latitudes. Globally speaking, composition changes in terms of enhancements in the N2/O ratio are mainly responsible for negative storm effects. However, although there is some correlation between increases in N2/O and decreases in the F layer critical frequency f0F2 in the winter hemisphere during the storm main phase and early recovery phase, the overall changes in f0F2 are also determined by other processes, such as the ionization production associated with enhanced auroral precipitation and the variations associated with TIDs. In the low to middle-latitude region changes in f0F2 approximately anticorrelate with changes at the height of the F layer electron density peak (e.g., hmF2) at 70°W during the storm main phase as well as its early recovery phase. This is attributed in part to the relation that exists

  17. The Influence of European Pollution on Ozone in the Near East and Northern Africa

    NASA Technical Reports Server (NTRS)

    Duncan, B. N.; West, J. J.; Yoshida, Y.; Fiore, A. M.; Ziemke, J. R.

    2008-01-01

    We present a modeling study of the long-range transport of pollution from Europe, showing that European emissions regularly elevate surface ozone by as much as 20 ppbv in summer in northern Africa and the Near East. European emissions cause 50-150 additional violations per year (i.e. above those that would occur without European pollution) of the European health standard for ozone (8-h average greater than 120 micrograms per cubic meters or approximately 60 ppbv) in northern Africa and the Near East. We estimate that European ozone pollution is responsible for 50 000 premature mortalities globally each year, of which the majority occurs outside of Europe itself, including 37% (19 000) in northern Africa and the Near East. Much of the pollution from Europe is exported southward at low altitudes in summer to the Mediterranean Sea, northern Africa and the Near East, regions with favorable photochemical environments for ozone production. Our results suggest that assessments of the human health benefits of reducing ozone precursor emissions in Europe should include effects outside of Europe, and that comprehensive planning to improve air quality in northern Africa and the Near East likely needs to address European emissions.

  18. Habitat manipulation influences northern bobwhite resource selection on a reclaimed surface mine

    USGS Publications Warehouse

    Brooke, Jarred M.; Peters, David C.; Unger, Ashley M.; Tanner, Evan P.; Harper, Craig A.; Keyser, Patrick D.; Clark, Joseph D.; Morgan, John J.

    2015-01-01

    More than 600,000 ha of mine land have been reclaimed in the eastern United States, providing large contiguous tracts of early successional vegetation that can be managed for northern bobwhite (Colinus virginianus). However, habitat quality on reclaimed mine land can be limited by extensive coverage of non-native invasive species, which are commonly planted during reclamation. We used discrete-choice analysis to investigate bobwhite resource selection throughout the year on Peabody Wildlife Management Area, a 3,330-ha reclaimed surface mine in western Kentucky. We used a treatment-control design to study resource selection at 2 spatial scales to identify important aspects of mine land vegetation and whether resource selection differed between areas with habitat management (i.e., burning, disking, herbicide; treatment) and unmanaged units (control). Our objectives were to estimate bobwhite resource selection on reclaimed mine land and to estimate the influence of habitat management practices on resource selection. We used locations from 283 individuals during the breeding season (1 Apr–30 Sep) and 136 coveys during the non-breeding season (1 Oct–Mar 31) from August 2009 to March 2014. Individuals were located closer to shrub cover than would be expected at random throughout the year. During the breeding season, individuals on treatment units used areas with smaller contagion index values (i.e., greater interspersion) compared with individuals on control units. During the non-breeding season, birds selected areas with greater shrub-open edge density compared with random. At the microhabitat scale, individuals selected areas with increased visual obstruction >1 m aboveground. During the breeding season, birds were closer to disked areas (linear and non-linear) than would be expected at random. Individuals selected non-linear disked areas during winter but did not select linear disked areas (firebreaks) because they were planted to winter wheat each fall and

  19. Northern pintail body condition during wet and dry winters in the Sacramento Valley, California

    USGS Publications Warehouse

    Miller, M.R.

    1986-01-01

    Body weights and carcass composition of male and female adult northern pintails (Anas acuta) were investigated in the Sacramento Valley, California, from August to March 1979-82. Pintails were lightweight, lean, and had reduced breast, leg, and heart muscles during August-September. Ducks steadily gained weight after arrival; and body, carcass (body wt minus feathers and gastrointestinal content), fat protein, and muscle weights peaked in October-November. Fat-free dry weight remained high but variable the rest of the winter, whereas body and carcass weight and fat content declined to lows in December or January, then increased again in February or March. Gizzard weights declined from early fall to March. Males were always heavier than females, but females were fatter (percentage) than males during mid-winter. Mid-winter body weight, carcass fat, and protein content were significantly (P < 0.01) lower in the dry winter of 1980-81 than in 2 wet winters (1979-80 and 1981-82). Changes in pintail body weight and composition during winter are probably adaptations to mild climate, predictable food supplies, and requirements for pair formation and molt.

  20. Topographical inversion of sandy soils due to local conditions in Northern Poland

    NASA Astrophysics Data System (ADS)

    Jankowski, Michał; Przewoźna, Bogusława; Bednarek, Renata

    2011-12-01

    The investigations carried out in the slope zone of two sandy glaciofluvial terraces in the Toruń Basin (Northern Poland, Central Europe) have shown the occurrence of an inverse slope-sequence of soils. Ground water-affected Gleyic soils (Gleysols) are developed on the surface of the higher terrace and automorphic Rusty Soils (Brunic Arenosols) occupy the lower terrace. The additional element of the sequence unusual for the subboreal zone where the studies take place is the appearance of red colored Ochre Soils (Rubic Arenosols) which are distinctly enriched with iron. The aim of this study is to explain the causes of such distribution of soils. The results show that the difference in stratigraphy of both terraces is the reason for the described phenomena. The lower terrace—of an erosional-accumulative type—is built of deep, permeable glaciofluvial sands. At the higher one, having an erosional character, sandy deposits are underlain with fine-grained lake deposits at a relatively shallow depth. Thus, ground water is retained there leading to the formation of Gleyic soils, but sinks in the deep sands of the lower terrace, where Rusty soils appear. The genesis of Ochre soils should be interpreted as the result of iron oxidation in the transitional zone between the two terraces.

  1. The Influence of Global Climate Changes on Storm-Tracks of Northern Hemisphere

    NASA Astrophysics Data System (ADS)

    Martynova, Y.; Krupchatnikov, V. N.

    2012-12-01

    Non-stationary eddies in mid-latitude storm-tracks are an important mechanism of energy, moment and moisture transfer in climate system [1]. Baroclinic eddies bring heavy rains and other hazard weather phenomena in the middle latitudes, play an important role in the global energy and the hydrological cycle. Recently, the increase of a cyclones rate at high latitudes with their frequency decrease in the second half of the 20th century was discovered using reanalysis data [2,3]. However, there is still no common point of view about how storm-track's distribution and intensity will be changed under the climate change influence [4,5]. In our work we investigate a variation of transient eddies general propagation tracks as a result of the global climate change effect. Using global large-scale intermediate complexity model of climate system [6] the numerical experiment was provided for the time period from 850 to 3000 year with a scenario of greenhouse gases influence on climate. From 850 to 2005 this impact was set according to the protocol "Historical simulations" of CMIP5 [7]. For 21th century anthropogenic effects were set according to the most aggressive scenario RCP 8.5 [8]. For the period 22-23 centuries CO2 concentration was on the level of 2100 year, and for 24-30 centuries it returned to pre-industrial value linearly in time of 100 years. Using a filter [9] we defined three variation intervals: low-frequency, medium-frequency and high-frequency. In our work we paid attention to medium-scale waves (i.e. 2-8 days). Two seasons were chosen: winter and summer. For each season we considered average fields of parameters characterizing poleward heat flux at 700 mb and transient eddies variance at 250 mb. Besides of the sensitivity of storm-track dynamic we considered some other features of "warm" climate. The work is partially supported by The Ministry of Education and Science of the Russian Federation #(#07.514.11.4044), RFBR grants #10-07-00547, #11-05-01190, and SB

  2. Fluvial depositional environment evolving into deltaic setting with marine influences in the buntsandstein of northern vosges (France)

    NASA Astrophysics Data System (ADS)

    Gall, Jean-Claude

    The Buntsandstein in the Northern Vosges (France) originates mainly in an inland braidplain fluvial environment which passes in the upper part of the sequence into deltaic milieu in the coastal plain along the border of the sea, with the continental environment finally being drowned with the transgression of the shallow sea. The fluvial sedimentation is characterized by the presence of two facies throughout the Buntsandstein : channel facies and overbank plain facies. The channel facies comprises sandy and conglomeratic deposits forming within active streams by strong currents, whereas the overbank plain facies is built up of silty-clayey sandstones or silt/clay originating in stagnant water in abandoned watercourses, ponds, pools and puddles. The significance of particularly the floodplain sediments is subjected to considerable changes throughout the Buntsandstein sequence. There are all stages of transition between overbank plain deposits being only preserved in ghost-like facies as reworked clasts due to effective secondary removal of primarily occasionally formed suspension fines, and an abundance of autochthonous floodplain sediments in the depositional record resulting from favourable conditions of primary origin and secondary preservation. Reworked ventifacts within fluvial channel sediments testify to subordinate aeolian influences in the alluvial plain, with reasonable reworking, however, having removed all in situ traces of wind activity. Declining aridity of palaeoclimate towards the top is indicated by the appearance of violet horizon palaeosols in the Zone-Limite-Violette and the Couches intermédiaires being accompanied by Bröckelbank carbonate breccias originating from concentration of reworked fragments of pedogenic carbonate nodules. Biogenic traces are in the lower part of the sequence mainly present as Planolites burrows in the finer-grained sediments. Palaeosalinities as revealed from boron contents indicate progressively increasing

  3. Influence of combined oral contraceptives on the periodontal condition

    PubMed Central

    DOMINGUES, Roberta Santos; FERRAZ, Bruna Fidêncio Rahal; GREGHI, Sebastião Luiz Aguiar; de REZENDE, Maria Lúcia Rubo; PASSANEZI, Euloir; SANT'ANA, Adriana Campos Passanezi

    2012-01-01

    Most studies investigating the impact of oral contraceptives have been performed some years ago, when the level of sexual hormones was greater than the actual formulations. Objective The aim of this study was to evaluate the effects of current combined oral contraceptives (COC) on periodontal tissues, correlating the clinical parameters examined with the total duration of continuous oral contraceptive intake. Material and methods Twenty-five women (19-35 years old) taking combined oral contraceptives for at least 1 year were included in the test group. The control group was composed by 25 patients at the same age range reporting no use of hormone-based contraceptive methods. Clinical parameters investigated included pocket probing depth (PD), clinical attachment level (CAL), sulcular bleeding index (SBI) and plaque index (Pl.I). Data were statistically evaluated by unpaired t test, Pearson's correlation test and Spearman's correlation test. Results The test group showed increased PD (2.228±0.011 x 2.154±0.012; p<0.0001) and SBI (0.229±0.006 x 0.148±0.005, p<0.0001) than controls. No significant differences between groups were found in CAL (0.435±0.01 x 0.412±0.01; p=0.11). The control group showed greater Pl.I than the test group (0.206±0.007 x 0.303±0.008; p<0.0001). No correlation between the duration of oral contraceptive intake, age and periodontal parameters was observed. Conclusions These findings suggest that the use of currently available combined oral contraceptives can influence the periodontal conditions of the patients, independently of the level of plaque accumulation or total duration of medication intake, resulting in increased gingival inflammation. PMID:22666846

  4. Culture and Caregivers: Factors Influencing Breastfeeding among Mothers in West Belfast, Northern Ireland

    ERIC Educational Resources Information Center

    Bishop, Hilary; Cousins, Wendy; Casson, Karen; Moore, Ann

    2008-01-01

    Breastfeeding is a key public health measure to protect and promote the health of one of the most vulnerable groups of the population--infants and children. Northern Ireland, however, has one of the lowest breastfeeding rates in the world. This paper reports the results of a questionnaire survey of 120 mothers attending mother and toddler groups…

  5. Cultural Attitudes, Parental Aspirations, and Socioeconomic Influence on Post-Primary School Selection in Northern Ireland

    ERIC Educational Resources Information Center

    Kelleher, Luke; Smyth, Austin; McEldowney, Malachy

    2016-01-01

    This research considers implications of planned reform of the education system in Northern Ireland for school choice and travel behavior. The school system is currently segregated on the basis of religion and academic ability at age 11. Discrete Choice Models based on a Stated Preference experiment included in a program of parental surveys yielded…

  6. Genetics Home Reference: Northern epilepsy

    MedlinePlus

    ... Understand Genetics Home Health Conditions Northern epilepsy Northern epilepsy Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Northern epilepsy is a genetic condition that causes recurrent seizures ( ...

  7. The Influence of Specific Physical Health Conditions on Retirement Decisions

    ERIC Educational Resources Information Center

    Shultz, Kenneth S.; Wang, Mo

    2007-01-01

    Physical health has consistently been shown to strongly influence the retirement decision-making process. Unfortunately, "physical health" is typically operationalized in global terms. As a result, we know little about the specific aspects of physical health that influence the decision to retire. Therefore, in the present study, data from three…

  8. The environmental history and present condition of Saudi Arabia's northern sand seas

    USGS Publications Warehouse

    Whitney, John W.; Faulkender, D.J.; Rubin, Meyer

    1983-01-01

    Saudi Arabia's northern sand seas are composed dominantly of stable dune systems, even though the modern climate is arid. The stable dunes are large and support a sparse semidesert vegetation. Active dunes are small and commonly confined to the crests of stable dunes; they comprise less than 5 percent of the dunes in the sand seas. Both the stability of the major dune systems and the small percentage of active dunes in the modern environment indicate a significant decrease in the average velocity and frequency of sand-moving winds since the time of stable-dune deposition. Comparison of modern wind directions with dune trends indicates that southwesterly winds responsible for dune formation in the southern and western An Nafud sand sea and in Nafud Urayq are no longer prevailing winds. Lake deposits are locally interbedded with deposits of eolian sand and in the lee of stable dunes. Radiocarbon dating of calcareous lake deposits defines at least two episodes of moisture-effective climate and minimal eolianactivity: between about 32,000 and 24,000 B.P., just before the onset of the last worldwide glacial stade of the Pleistocene, and during the Holocene between about 8,500 and 5,000 B.P. One lake deposit is more than 38,000 years old and may have been deposited during an earlier pluvial episode about 85,000 to 70,000 B.P. Pollen extracted from these lake deposits indicates that vegetation during late Pleistocene and Holocene pluvial episodes was similar to the present semidesert vegetation; however, the density of shrubs and grasses on the dunes was greater. The main dune systems overlie the 32,000 to 24,000-yearold lake deposits, whereas the Holocene lakebeds are found in modern interdunal environments, usually at the base of stable dunes. The main dune systems probably formed between 24,000 and 8,500 B.P., during the last episode of worldwide cold temperatures. Increased windiness at this time is also recorded in the world's oceans and in both polar ice caps

  9. Benthic conditions around a historic shipwreck: Vrouw Maria (1771) in the northern Baltic proper

    NASA Astrophysics Data System (ADS)

    Ruuskanen, A. T.; Kraufvelin, P.; Alvik, R.; Díaz, E. R.; Honkonen, J.; Kanerva, J.; Karell, K.; Kekäläinen, P.; Lappalainen, J.; Mikkola, R.; Mustasaari, T.; Nappu, N.; Nieminen, A.; Roininen, J.; Svahnbäck, K.

    2015-04-01

    Since her shipwreck in 1771, the wooden vessel Vrouw Maria has been lying on the seabed at 41 m depth on the border between the Archipelago Sea and the northern Baltic proper, off the southern coast of Finland. The wreck lies in an upward position in a right angle to the dominating bottom current, which is potentially affecting seabed topography, sediment characteristics and zoobenthic communities both upstream (NE) and downstream (SW) of the wreck. This multidisciplinary study attempts to clarify abiotic and biotic patterns and processes in the vicinity of the wreck by combining field investigations with physical simulation studies in the field and in the laboratory. Multibeam echo-sounder techniques were utilised to generate a map of the wreck area and sediment grab samples were taken to characterize the sediment type and its zoobenthic community. A medium-sized field experiment generated data on the accumulation of sediment organic matter in the presence and absence of a current and/or a barrier on the seafloor and a small-scaled laboratory study was conducted to simulate scour forming processes. The results showed that a deeper basin, scour area, with the dimensions 150×300 m, was present downstream of the wreck and there was also a smaller scour area upstream of the wreck. Similar traces on the bottom were simulated in the laboratory. The organic content (recent mud) and the proportion of finer sediment were more pronounced in areas closer to both sides of the wreck. These results were in turn imitated in a field experiment, where the accumulation of organic matter in the sediment increased significantly downstream, when a current was interrupted by a barrier. Regarding zoobenthos in the wreck area, 11 taxa and a mean total abundance of 773 individuals per m2 were registered. The dominant species were Macoma balthica and Marenzelleria sp., which together made up >80% of the total number of individuals. Multivariate data analyses showed significant differences

  10. Environmental Conditions in Northern Gulf of Mexico Estuaries: Before and After the Deepwater Horizon Oil Spill

    EPA Science Inventory

    When conducting an environmental assessment to determine the ecological effects of the Deepwater Horizon (DWH) Oil Spill in the Gulf of Mexico (GOM), baseline environmental data is essential to establish ecosystem condition prior to the incident. EPA’s National Coastal Assessment...

  11. Effects of Socioeconomic Status on Television Viewing Conditions of Preschoolers in Northern Greece

    ERIC Educational Resources Information Center

    Natsiopoulou, Triantafillia; Melissa-Halikiopoulou, Chrisoula

    2009-01-01

    The purpose of this study was to identify the effects of television (TV) on preschoolers, their TV viewing patterns and the conditions under which they watch TV, taking into consideration their different socioeconomic and regional backgrounds. The survey instrument was a questionnaire with 23 closed-ended questions, given to parents whose children…

  12. Summer Fish Communities in Northern Gulf of Mexico Estuaries: Indices of Ecological Condition

    EPA Science Inventory

    We used fish community data from trawl samples in >100 estuaries, bayous, and coastal lagoons of the Louisianan Biogeographic Province (Gulf of Mexico) to develop indicators of ecological condition. One data set, from which we derived reference values for fish community indicator...

  13. Is long range transport of pollen in the NW Mediterranean basin influenced by Northern Hemisphere teleconnection patterns?

    PubMed

    Izquierdo, Rebeca; Alarcon, Marta; Periago, Cristina; Belmonte, Jordina

    2015-11-01

    Climatic oscillations triggered by the atmospheric modes of the Northern Hemisphere teleconnection patterns have an important influence on the atmospheric circulation at synoptic scale in Western Mediterranean Basin. Simultaneously, this climate variability could affect a variety of ecological processes. This work provides a first assessment of the effect of North Atlantic Oscillation (NAO), Arctic Oscillation (AO) and Western Mediterranean Oscillation (WeMO) on the atmospheric long-range pollen transport episodes in the North-Eastern Iberian Peninsula for the period 1994-2011. Alnus, Ambrosia, Betula, Corylus and Fagus have been selected as allergenic pollen taxa with potential long-range transport associated to the Northern Hemisphere teleconnection patterns in the Western Mediterranean Basin. The results showed an increase of long range pollen transport episodes of: (1) Alnus, Corylus and Fagus from Western and Central Europe during the negative phase of annual NAO and AO; (2) Ambrosia, Betula and Fagus from Europe during the negative phase of winter WeMO; (3) Corylus and Fagus from Mediterranean area during the positive phase of the annual AO; and (4) Ambrosia from France and Northern Europe during the positive phase of winter WeMO. Conversely, the positive phase of annual NAO and AO are linked with the regional transport of Alnus, Betula and Corylus from Western Iberian Peninsula. The positive phase of annual WeMO was also positively correlated with regional transport of Corylus from this area. PMID:26125408

  14. The Influence of Meteorological Conditions on Air Pollution

    ERIC Educational Resources Information Center

    Campbell, N. A.; Gipps, J.

    1975-01-01

    Explains the distribution of air pollutants as related to such meteorological conditions as temperature inversions, ground inversion, and wind velocity. Uses a power station to illustrate the effect of some of the meteorological conditions mentioned. (GS)

  15. Solar Absorption Refrigeration System for Air-Conditioning of a Classroom Building in Northern India

    NASA Astrophysics Data System (ADS)

    Agrawal, Tanmay; Varun; Kumar, Anoop

    2015-10-01

    Air-conditioning is a basic tool to provide human thermal comfort in a building space. The primary aim of the present work is to design an air-conditioning system based on vapour absorption cycle that utilizes a renewable energy source for its operation. The building under consideration is a classroom of dimensions 18.5 m × 13 m × 4.5 m located in Hamirpur district of Himachal Pradesh in India. For this purpose, cooling load of the building was calculated first by using cooling load temperature difference method to estimate cooling capacity of the air-conditioning system. Coefficient of performance of the refrigeration system was computed for various values of strong and weak solution concentration. In this work, a solar collector is also designed to provide required amount of heat energy by the absorption system. This heat energy is taken from solar energy which makes this system eco-friendly and sustainable. A computer program was written in MATLAB to calculate the design parameters. Results were obtained for various values of solution concentrations throughout the year. Cost analysis has also been carried out to compare absorption refrigeration system with conventional vapour compression cycle based air-conditioners.

  16. Local and regional variability in snow conditions in northern Finland: A reindeer herding perspective.

    PubMed

    Rasmus, Sirpa; Kivinen, Sonja; Bavay, Mathias; Heiskanen, Janne

    2016-05-01

    Weather station measurements were used to force the SNOWPACK snow model and combined with reindeer herders' experiences to study the local and regional variations in snow conditions in a Finnish reindeer herding area for the 1981-2010 period. Winter conditions varied significantly between the four selected herding districts and between open and forest environments within the districts. The highest snow depths and densities, the thicknesses of ground ice, and the lengths of snow cover period were generally found in the northernmost districts. The snow depths showed the strongest regional coherence, whereas the thicknesses of ground ice were weakly correlated among the districts. The local variation in snow depths was higher than the regional variation and limits for rare or exceptional events varied notably between different districts and environments. The results highlight that forests diversify snow and foraging conditions, e.g., ground ice rarely forms simultaneously in different environments. Sufficient and diverse forest pastures are important during the critical winter season if reindeer herding is pursued on natural grazing grounds also in the future. PMID:26754168

  17. Local and regional variability in snow conditions in northern Finland: A reindeer herding perspective.

    PubMed

    Rasmus, Sirpa; Kivinen, Sonja; Bavay, Mathias; Heiskanen, Janne

    2016-05-01

    Weather station measurements were used to force the SNOWPACK snow model and combined with reindeer herders' experiences to study the local and regional variations in snow conditions in a Finnish reindeer herding area for the 1981-2010 period. Winter conditions varied significantly between the four selected herding districts and between open and forest environments within the districts. The highest snow depths and densities, the thicknesses of ground ice, and the lengths of snow cover period were generally found in the northernmost districts. The snow depths showed the strongest regional coherence, whereas the thicknesses of ground ice were weakly correlated among the districts. The local variation in snow depths was higher than the regional variation and limits for rare or exceptional events varied notably between different districts and environments. The results highlight that forests diversify snow and foraging conditions, e.g., ground ice rarely forms simultaneously in different environments. Sufficient and diverse forest pastures are important during the critical winter season if reindeer herding is pursued on natural grazing grounds also in the future.

  18. Orientation, composition, and entrapment conditions of fluid inclusions in the footwall of the northern Snake Range detachment, Nevada

    NASA Astrophysics Data System (ADS)

    Carter, Matthew J.; Siebenaller, Luc; Teyssier, Christian

    2015-12-01

    Footwall rocks of the northern Snake Range detachment fault (Hampton and Hendry's Creeks) offer exposures of quartzite mylonites (sub-horizontal foliation) that were permeated by surface fluids. An S-C-C‧ mylonitic fabric is defined by dynamically recrystallized quartz and mica. Electron backscatter diffraction analyses indicate a strong preferred orientation of quartz that is overprinted by two sets of sub-vertical, ESE and NNE striking fractures. Analyses of sets of three perpendicular thin sections indicate that fluid inclusions (FIs) are arranged according to macroscopic fracture patterns. FIs associated with NNE and ESE-striking fractures coevally trapped unmixed CO2 and H2O-rich fluids at conditions near the critical CO2-H2O solvus, giving minimum trapping conditions of T = 175-200 °C and ˜100 MPa H2O-rich FIs trapped along ESE-trending microcracks in single crystals of quartz may have been trapped at conditions as low as 150 °C and 50 MPa indicating the latest microfracturing and annealing of quartz in an overall extensional system. Results suggest that the upper crust was thin (4-8 km) during FI trapping and had an elevated geotherm (>50 °C/km). Footwall rocks that have been exhumed through the brittle-ductile transition in such extensional systems experience both brittle and crystal-plastic deformation that may allow for circulation of meteoric fluids and grain-scale fluid-rock interactions.

  19. West Nile Virus Surveillance in 2013 via Mosquito Screening in Northern Italy and the Influence of Weather on Virus Circulation.

    PubMed

    Calzolari, Mattia; Pautasso, Alessandra; Montarsi, Fabrizio; Albieri, Alessandro; Bellini, Romeo; Bonilauri, Paolo; Defilippo, Francesco; Lelli, Davide; Moreno, Ana; Chiari, Mario; Tamba, Marco; Zanoni, Mariagrazia; Varisco, Giorgio; Bertolini, Silvia; Modesto, Paola; Radaelli, Maria Cristina; Iulini, Barbara; Prearo, Marino; Ravagnan, Silvia; Cazzin, Stefania; Mulatti, Paolo; Monne, Isabella; Bonfanti, Lebana; Marangon, Stefano; Goffredo, Maria; Savini, Giovanni; Martini, Simone; Mosca, Andrea; Farioli, Marco; Gemma Brenzoni, Laura; Palei, Manlio; Russo, Francesca; Natalini, Silvano; Angelini, Paola; Casalone, Cristina; Dottori, Michele; Capelli, Gioia

    2015-01-01

    West Nile virus (WNV) is a recently re-emerged health problem in Europe. In Italy, an increasing number of outbreaks of West Nile disease, with occurrences of human cases, have been reported since 2008. This is particularly true in northern Italy, where entomological surveillance systems have been implemented at a regional level. The aim of this study was to use, for the first time, all the entomological data collected in the five regions undergoing surveillance for WNV in northern Italy to characterize the viral circulation (at a spatial and temporal scale), identify potential mosquito vectors, and specify relationships between virus circulation and meteorological conditions. In 2013, 286 sites covering the entire Pianura Padana area were monitored. A total of 757,461 mosquitoes were sampled. Of these, 562,079 were tested by real-time PCR in 9,268 pools, of which 180 (1.9%) were positive for WNV. The largest part of the detected WNV sequences belonged to lineage II, demonstrating that, unlike those in the past, the 2013 outbreak was mainly sustained by this WNV lineage. This surveillance also detected the Usutu virus, a WNV-related flavivirus, in 241 (2.6%) pools. The WNV surveillance systems precisely identified the area affected by the virus and detected the viral circulation approximately two weeks before the occurrence of onset of human cases. Ninety percent of the sampled mosquitoes were Culex pipiens, and 178/180 WNV-positive pools were composed of only this species, suggesting this mosquito is the main WNV vector in northern Italy. A significantly higher abundance of the vector was recorded in the WNV circulation area, which was characterized by warmer and less rainy conditions and greater evapotranspiration compared to the rest of the Pianura Padana, suggesting that areas exposed to these conditions are more suitable for WNV circulation. This observation highlights warmer and less rainy conditions as factors able to enhance WNV circulation and cause virus

  20. West Nile Virus Surveillance in 2013 via Mosquito Screening in Northern Italy and the Influence of Weather on Virus Circulation

    PubMed Central

    Calzolari, Mattia; Pautasso, Alessandra; Montarsi, Fabrizio; Albieri, Alessandro; Bellini, Romeo; Bonilauri, Paolo; Defilippo, Francesco; Lelli, Davide; Moreno, Ana; Chiari, Mario; Tamba, Marco; Zanoni, Mariagrazia; Varisco, Giorgio; Bertolini, Silvia; Modesto, Paola; Radaelli, Maria Cristina; Iulini, Barbara; Prearo, Marino; Ravagnan, Silvia; Cazzin, Stefania; Mulatti, Paolo; Monne, Isabella; Bonfanti, Lebana; Marangon, Stefano; Goffredo, Maria; Savini, Giovanni; Martini, Simone; Mosca, Andrea; Farioli, Marco; Gemma Brenzoni, Laura; Palei, Manlio; Russo, Francesca; Natalini, Silvano; Angelini, Paola; Casalone, Cristina; Dottori, Michele; Capelli, Gioia

    2015-01-01

    West Nile virus (WNV) is a recently re-emerged health problem in Europe. In Italy, an increasing number of outbreaks of West Nile disease, with occurrences of human cases, have been reported since 2008. This is particularly true in northern Italy, where entomological surveillance systems have been implemented at a regional level. The aim of this study was to use, for the first time, all the entomological data collected in the five regions undergoing surveillance for WNV in northern Italy to characterize the viral circulation (at a spatial and temporal scale), identify potential mosquito vectors, and specify relationships between virus circulation and meteorological conditions. In 2013, 286 sites covering the entire Pianura Padana area were monitored. A total of 757,461 mosquitoes were sampled. Of these, 562,079 were tested by real-time PCR in 9,268 pools, of which 180 (1.9%) were positive for WNV. The largest part of the detected WNV sequences belonged to lineage II, demonstrating that, unlike those in the past, the 2013 outbreak was mainly sustained by this WNV lineage. This surveillance also detected the Usutu virus, a WNV-related flavivirus, in 241 (2.6%) pools. The WNV surveillance systems precisely identified the area affected by the virus and detected the viral circulation approximately two weeks before the occurrence of onset of human cases. Ninety percent of the sampled mosquitoes were Culex pipiens, and 178/180 WNV-positive pools were composed of only this species, suggesting this mosquito is the main WNV vector in northern Italy. A significantly higher abundance of the vector was recorded in the WNV circulation area, which was characterized by warmer and less rainy conditions and greater evapotranspiration compared to the rest of the Pianura Padana, suggesting that areas exposed to these conditions are more suitable for WNV circulation. This observation highlights warmer and less rainy conditions as factors able to enhance WNV circulation and cause virus

  1. Influence of variations in extratropical wintertime teleconnections on Northern Hemisphere temperature

    SciTech Connect

    Hurrell, J.W.

    1997-11-01

    The purpose of this paper to illustrate and quantify the relationship between the circulation changes and surface temperature anomalies in the northern hemisphere during winter. Multivariate linear regression was used to regress three indices on the northern hemisphere extratropical temperature anomolies for each winter since 1935. The indices regressed were the North Atlantic Oscillation, the North Pacific, and the Southern Oscillation; these were selected because they relate to well understood circulation anomolies that have persisted for much of the past two decades. Elements of the temperature anomaly pattern since the mid-1970s resemble the greenhouse warming fingerprint predicted by some general circulation models; however, it is difficult to assess the cause. The changes in circulation since the mid-1970s have resulted in a particular surface temperature anomaly pattern that has amplified the hemispheric-averaged warming because of the interaction with land and ocean. 7 refs., 3 figs.

  2. Lactase non-persistent genotype influences milk consumption and gastrointestinal symptoms in Northern Russians

    PubMed Central

    2011-01-01

    Background Milk is an important source of nutrients. The consumption of milk, however, may cause abdominal complaints in lactose intolerant individuals. The frequency of -13910C/C genotype is known to be high among Northern Russians, exceeding the prevalence in northern Europe. In our study we tested two hypotheses: 1) subjects with lactase non-persistent genotype (-13910C/C) have more gastrointestinal (GI) symptoms associated with milk 2) subjects with lactase non-persistence avoid using milk. Methods In total, 518 students aged 17 to 26 years were randomly selected from different departments in the Northern State Medical University (NSMU) for genotyping the lactase activity-defining -13910C/T variant. All subjects filled in a questionnaire covering their personal data, self-reported GI symptoms and milk consumption habits. Results Northern Russians consume very small amounts of milk daily. Among carriers of the lactase non-persistent (LNP) genotype there were 10 percentage units of milk-consumers fewer than among lactase-persistent (LP) subjects (p = 0.03). Complaints of GI disorders caused by milk were different between the genotypes (p = 0.02). Among all types of food analyzed only milk was associated with increased GI symptoms among subjects with the LNP genotype (OR = 1.95, CI 1.03-3.69) Conclusions Subjects with -13910C/C have more GI symptoms from milk. Subjects with lactase non-persistent genotype avoid using milk. In the case of increasing milk consumption symptoms may increase the need for medical consultation. It is thus important either for people themselves or for health care staff to be aware of lactase persistence/non-persistence. PMID:22078123

  3. Chronic Heat Stress and Cognitive Development: An Example of Thermal Conditions Influencing Human Development

    ERIC Educational Resources Information Center

    Riniolo, Todd C.; Schmidt, Louis A.

    2006-01-01

    Although thermal conditions influence the development of living organisms in a wide variety of ways, this topic has been recently ignored in humans. This paper reintroduces thermal conditions as a topic of importance for developmentalists by presenting an example of how thermal conditions are hypothesized to influence a particular developmental…

  4. Suboptimal Light Conditions Influence Source-Sink Metabolism during Flowering

    PubMed Central

    Christiaens, Annelies; De Keyser, Ellen; Pauwels, Els; De Riek, Jan; Gobin, Bruno; Van Labeke, Marie-Christine

    2016-01-01

    Reliance on carbohydrates during flower forcing was investigated in one early and one late flowering cultivar of azalea (Rhododendron simsii hybrids). Carbohydrate accumulation, invertase activity, and expression of a purported sucrose synthase gene (RsSUS) was monitored during flower forcing under suboptimal (natural) and optimal (supplemental light) light conditions, after a cold treatment (7°C + dark) to break flower bud dormancy. Post-production sucrose metabolism and flowering quality was also assessed. Glucose and fructose concentrations and invertase activity increased in petals during flowering, while sucrose decreased. In suboptimal light conditions RsSUS expression in leaves increased as compared to optimal light conditions, indicating that plants in suboptimal light conditions have a strong demand for carbohydrates. However, carbohydrates in leaves were markedly lower in suboptimal light conditions compared to optimal light conditions. This resulted in poor flowering of plants in suboptimal light conditions. Post-production flowering relied on the stored leaf carbon, which could be accumulated under optimal light conditions in the greenhouse. These results show that flower opening in azalea relies on carbohydrates imported from leaves and is source-limiting under suboptimal light conditions. PMID:26973689

  5. Suboptimal Light Conditions Influence Source-Sink Metabolism during Flowering.

    PubMed

    Christiaens, Annelies; De Keyser, Ellen; Pauwels, Els; De Riek, Jan; Gobin, Bruno; Van Labeke, Marie-Christine

    2016-01-01

    Reliance on carbohydrates during flower forcing was investigated in one early and one late flowering cultivar of azalea (Rhododendron simsii hybrids). Carbohydrate accumulation, invertase activity, and expression of a purported sucrose synthase gene (RsSUS) was monitored during flower forcing under suboptimal (natural) and optimal (supplemental light) light conditions, after a cold treatment (7°C + dark) to break flower bud dormancy. Post-production sucrose metabolism and flowering quality was also assessed. Glucose and fructose concentrations and invertase activity increased in petals during flowering, while sucrose decreased. In suboptimal light conditions RsSUS expression in leaves increased as compared to optimal light conditions, indicating that plants in suboptimal light conditions have a strong demand for carbohydrates. However, carbohydrates in leaves were markedly lower in suboptimal light conditions compared to optimal light conditions. This resulted in poor flowering of plants in suboptimal light conditions. Post-production flowering relied on the stored leaf carbon, which could be accumulated under optimal light conditions in the greenhouse. These results show that flower opening in azalea relies on carbohydrates imported from leaves and is source-limiting under suboptimal light conditions. PMID:26973689

  6. Beak condition and cage density determine abundance and spatial distribution of northern fowl mites, Ornithonyssus sylviarum, and chicken body lice, Menacanthus stramineus, on caged laying hens.

    PubMed

    Mullens, B A; Chen, B L; Owen, J P

    2010-12-01

    Adult White Leghorn hens (Hy-Line strain W-36) were inoculated with either northern fowl mites or chicken body lice, and the ectoparasite populations were monitored over periods of 9 to 16 wk. Two beak conditions (beak trimmed or beak intact) and 2 housing densities (1 or 2 hens per 25 × 31 cm suspended wire cage) were tested. Populations of both ectoparasites were at least 10 times lower on beak-intact hens compared with populations on beak-trimmed hens. Cage density did not influence mite numbers, but higher numbers of lice (2 to 3 times) developed on hens held at the higher cage density. Louse distribution on the body and louse population age structure were also influenced by host beak condition. Beak-intact hens had a higher proportion of lice under the wings, whereas beak-trimmed hens had the majority of lice on the lower abdomen. Louse populations on beak-trimmed hens also comprised relatively more immature stages than populations found on beak-intact hens. The effects are likely related to decreased grooming efficiency by beak-trimmed hens and, in the case of lice, the higher host density. The high mite and louse populations on most commercial caged laying hens are probably a direct result of beak trimming. However, selection of more docile breeds that can be held without trimming may allow the hens themselves to reduce ectoparasites below economically damaging levels. This could benefit producers, animal welfare advocates, and human health by reducing 1) costs of beak trimming, 2) pesticide treatment costs (including human and bird chemical exposure concerns), and 3) objections to beak trimming from the animal welfare community. PMID:21076093

  7. Pre-development conditions to assess the impact of growth in an urbanizing watershed in Northern Virginia

    NASA Astrophysics Data System (ADS)

    Kumar, Saurav; Godrej, Adil N.; Grizzard, Thomas J.

    2016-09-01

    Pre-development conditions are an easily understood state to which watershed nonpoint nutrient reduction targets may be referenced. Using the pre-development baseline, a "developed-excess" measure may be computed for changes due to anthropogenic development. Developed-excess is independent of many geographical, physical, and hydrological characteristics of the region and after normalization by area may be used for comparison among various sub-sets of the watershed, such as jurisdictions or land use types. We have demonstrated this method by computing pre-development nitrogen and phosphorus loads entering the Occoquan Reservoir from its tributary watershed in Northern Virginia. The pre-development loads in this study were computed using the calibrated water quality models for the period 2002-2007. Current forest land was used as a surrogate for pre-development land use conditions for the watershed and developed-excess was estimated for fluvial loads of Total Inorganic Nitrogen (TIN) and Orthophosphate-Phosphorus (OP) by subtracting simulated predevelopment loads from observed loads. It was observed that within the study period (2002-2007), the average annual developed-excess represented about 30% of the TIN and OP average annual loads exported to the reservoir. Comparison of the two disturbed land use types, urban and agricultural, showed that urban land uses exported significantly more excess nonpoint nutrient load per unit area than agricultural land uses.

  8. Conditions that Influence Drivers' Yielding Behavior for Uncontrolled Crossings

    ERIC Educational Resources Information Center

    Bourquin, Eugene; Emerson, Robert Wall; Sauerburger, Dona

    2011-01-01

    Pedestrians with visual impairments need to cross streets where traffic signals and traffic signage are not present. This study examined the influences of several interventions, including a pedestrian's use of a mobility cane, on the behavior of drivers when they were expected to yield to a pedestrian crossing at an uncontrolled crossing.…

  9. Analysis of technological conditions influence on efficiency of oilfield treatment

    NASA Astrophysics Data System (ADS)

    Usheva, N. V.; Moizes, O. E.; Kuzmenko, E. A.; Kim, S. F.; Khlebnikova, E. S.; Dyalilova, S. N.; Filippova, T. V.

    2015-11-01

    The results of influence of process parameters on oil quality and recommended effective technological modes of oilfield treatment processes are presented in this paper. It is shown that the parameters that significantly affect the efficiency of oil processes are temperature and water-oil emulsion flow rate with a given number of working process units and the structure of flowsheet flows.

  10. Influence of initial conditions on compressible vorticity dynamics

    NASA Astrophysics Data System (ADS)

    Virk, D.; Hussain, F.

    1993-11-01

    Prompted by the lack of a unique choice of pressure ( P) and density (ρ) fields for a compressible free vortex and by the observed dependence of turbulence dynamics on initial P and ρ in compressible simulations, we address the effects of initial conditions on the evolution of a single vortex, on the prototypical phenomenon of vortex reconnection, and on two-dimensional turbulence. Two previous choices of initial conditions used for numerical simulations of compressible turbulence have been: (i) both P and ρ uniform (constant initial conditions, CIC), and (ii) uniform ρ with P determined from the Poisson equation (constant density initial conditions, CDIC). We find these initial conditions to be inappropriate for compressible vorticity dynamics studies. Specifically, in compressible reconnection, the effects of baroclinic vorticity generation and shocklet formation cancel each other during early evolution for CDIC, thus leading to almost incompressible behavior. Although CIC captures compressibility effects, it incorrectly changes the initial vorticity distribution by introducing strong acoustic transients, thereby significantly altering the evolving dynamics. Here, a new initial condition, called polytropic initial condition (PIC), is proposed, for which the Poisson equation is solved for initially polytropically related P and ρ fields. PIC provides P and ρ distributions within vortices which are consistent with those observed in shock-wedge interaction experiment and also leads to compressible solutions with no acoustic transients. At low Mach number ( M), we show that the effects of all these three initial conditions can be predicted by low- M asymptotic theories of the Navier-Stokes equations. At high M, it is shown here that inappropriate initial conditions may alter the evolutionary dynamics and, hence, lead to wrong conclusions regarding compressibility effects. We argue that PIC is a more appropriate choice.

  11. Do breeding phase and detection distance influence the effective area surveyed for northern goshawks?

    USGS Publications Warehouse

    Roberson, A.M.; Andersen, D.E.; Kennedy, P.L.

    2005-01-01

    Broadcast surveys using conspecific calls are currently the most effective method for detecting northern goshawks (Accipiter gentilis) during the breeding season. These surveys typically use alarm calls during the nestling phase and juvenile food-begging calls during the fledgling-dependency phase. Because goshawks are most vocal during the courtship phase, we hypothesized that this phase would be an effective time to detect goshawks. Our objective was to improve current survey methodology by evaluating the probability of detecting goshawks at active nests in northern Minnesota in 3 breeding phases and at 4 broadcast distances and to determine the effective area surveyed per broadcast station. Unlike previous studies, we broadcast calls at only 1 distance per trial. This approach better quantifies (1) the relationship between distance and probability of detection, and (2) the effective area surveyed (EAS) per broadcast station. We conducted 99 broadcast trials at 14 active breeding areas. When pooled over all distances, detection rates were highest during the courtship (70%) and fledgling-dependency phases (68%). Detection rates were lowest during the nestling phase (28%), when there appeared to be higher variation in likelihood of detecting individuals. EAS per broadcast station was 39.8 ha during courtship and 24.8 ha during fledgling-dependency. Consequently, in northern Minnesota, broadcast stations may be spaced 712m and 562 m apart when conducting systematic surveys during courtship and fledgling-dependency, respectively. We could not calculate EAS for the nestling phase because probability of detection was not a simple function of distance from nest. Calculation of EAS could be applied to other areas where the probability of detection is a known function of distance.

  12. A possible influence of recent polar stratospheric coolings on the troposphere in the northern hemisphere winter

    SciTech Connect

    Kunihiko Kodera; Koji Yamazaki )

    1994-05-01

    The authors study possible correlations between stratospheric cooling trends and increased circulation in the northern hemispheric troposphere in the period 1979 to 1992. These changes are compared with the effect of stratospheric heating which resulted from several aerosol injections from major volcanic activity during this period. These injections act much like an external forcing function applied to the stratosphere, and allow one to infer information on the response of the stratosphere/troposphere system to this dynamic input. For both cases one can observe perturbations in the zonal/mean zonal winds propogating into the troposphere.

  13. Influence of impurity gases and operating conditions on PAFC performance

    SciTech Connect

    Hirai, K.; Iwasa, N.; Suzuki, M.; Okada, O.

    1996-12-31

    On-site Phosphoric Acid Fuel Cell (PAFC) Cogeneration system is installed at various test sites, such as at underground parking lot, within chemical plant premises and near urban streets. Since in the current PAFC system, cathode air is supplied to the cell with no particular pretreatment, impurity gases in the air might influence on cell performance. We have investigated the influence of various impurity gases in the cathode gas, on sub-scale single cells, and have found that NO{sub 2}, SO{sub 2} and toluene affect negatively on cell performance. The results of these experiments and the conceivable mechanism of these effects on cell degradation are reported. We have also investigated the influence of other operating parameters, such as temperature, current density, fuel utilization on cell performance. From these experiments, we have found that operating temperature is a significant factor, which mainly determines cell voltage decline rate. The results of sub-scale single cell tests and a short-stack verification test are also reported.

  14. Influence of vegetation on water isotope partitioning across different northern headwater catchments

    NASA Astrophysics Data System (ADS)

    Gabor, R. S.; Tetzlaff, D.; Buttle, J. M.; Carey, S. K.; Laudon, H.; Mitchell, C. P. J.; McNamara, J. P.; Soulsby, C.

    2014-12-01

    The hydrology of high latitude catchments is sensitive to small changes in temperature, and likely to be impacted by changes in climate. Vegetation water usage can play a large role in catchment hydrologic pathways, affecting how water is stored, released, and partitioned within a landscape. Thus a better understanding of how vegetation impacts water partitioning in northern catchments can help us understand how climate change will impact high-latitude hydrology. As part of the VeWa project, five catchments were chosen between 44oN and 64oN in Europe and North America, to compare the role of vegetation in the movement of water across northern landscapes. These catchments vary in aspect as well as extent of snowpack and their vegetative landscapes include heather moorland, coniferous and deciduous forests, mixed grass, and tundra landscapes. Importantly, all the catchments have records of stable isotopes in different waters of the system. An initial comparison of the water isotopes in these catchments demonstrates variation between the catchments, with the lower latitude sites showing more fractionation suggestive of evapotranspiration. While all catchments show a depletion of heavy isotopes in the spring, the depletion is most evident in catchments with a heavier snowpack. The vegetative growing season during the summer months shows the greatest impact of evapotranspiration on isotopes, indicating that an increased summer in a warmer climate would likely alter water partitioning and storage dynamics in these regions.

  15. Influence of dietary 2,4,6-trinitrotoluene exposure in the northern bobwhite (Colinus virginianus).

    PubMed

    Gogal, Robert M; Johnson, Mark S; Larsen, Calvert T; Prater, Mary R; Duncan, Robert B; Ward, Daniel L; Holladay, Steven D

    2002-01-01

    The risk to wildlife from exposure to the explosive, 2,4,6-trinitrotoluene (TNT) has been a concern at numerous military installations where it has been found in the soil. To date, no published data are available describing effects of TNT exposure in an avian species. Subchronic dietary exposure to TNT was therefore evaluated in a species of management concern at military installations, the northern bobwhite (Colinus virginianus). Adult male and female quail (n = 5/sex/dose) were given commercial feed containing 3,000, 1,500, 750, and 100 mg/kg TNT for 90 d following the determination of an acute lethal dose and a 14-d range finding study. Dietary TNT intake caused a dose-dependent decrease in total red blood cell counts, packed cell volume, total plasma protein, blood prolymphocytes, and blood lymphocytes. An increased trend in late apoptotic/necrotic blood leukocytic cells was also observed in TNT-exposed birds, as was hemosiderosis in the liver. With the exception of hemosiderosis, these trends were statistically significant yet of questionable biological significance. Since treatment-related responses in this preliminary study were variable, a conservative interpretation is suggested. However, since these treatments had concentrations that were a log-fold or more than doses in similar studies using mammals, these data suggest that northern bobwhite are less sensitive to oral exposures of TNT than mammals.

  16. Post-bomb coral Δ14C record from Iki Island, Japan: possible evidence of oceanographic conditions on the northern East China Sea shelf

    NASA Astrophysics Data System (ADS)

    Mitsuguchi, Takehiro; Hirota, Masashi; Paleo Labo AMS Dating Group; Yamazaki, Atsuko; Watanabe, Tsuyoshi; Yamano, Hiroya

    2016-07-01

    Nansei Islands area; (2) the shelf-surface water is conveyed from the northern ECS to Iki Island by the Tsushima Current. Thus, it can be suggested that the post-bomb coral Δ14C record from Iki Island reflects oceanographic conditions of the northern ECS shelf.

  17. Post-bomb coral Δ14C record from Iki Island, Japan: possible evidence of oceanographic conditions on the northern East China Sea shelf

    NASA Astrophysics Data System (ADS)

    Mitsuguchi, Takehiro; Hirota, Masashi; Group, Paleo Labo AMS Dating; Yamazaki, Atsuko; Watanabe, Tsuyoshi; Yamano, Hiroya

    2016-10-01

    Nansei Islands area; (2) the shelf-surface water is conveyed from the northern ECS to Iki Island by the Tsushima Current. Thus, it can be suggested that the post-bomb coral Δ14C record from Iki Island reflects oceanographic conditions of the northern ECS shelf.

  18. The effect of northern fowl mite (Ornithonyssus sylviarum) infestation on hen physiology, physical condition, and egg quality.

    PubMed

    Vezzoli, Giuseppe; King, Annie J; Mench, Joy A

    2016-05-01

    The northern fowl mite (NFM),Ornithonyssus sylviarum, is the most common ectoparasite of laying hens in North America. Infestation can cause a reduction in egg production, egg weights, and feed conversion efficiency. However, there is a lack of information on the effects of NFM on hen physiology, physical condition, and egg quality. Singly caged beak-trimmed White Leghorn hens (N=32) were infested with mites at 25 wk of age. The condition of each hen was assessed at wk 0 (infestation) and wk 5 and 7 post-infestation to determine comb temperatures and feather, skin, and comb condition. Heterophil-lymphocyte (H/L) ratios and body weight (BW) were evaluated at wk 0 and wk 1, 3, 5, and 7 post-infestation. Egg weight, egg specific gravity, yolk color, Haugh unit (HU), and eggshell thickness were determined prior to infestation (wk -1) and at 1, 3, 5, and 7 wk post-infestation. The H/L ratio (P<0.0001), HU (P<0.0001), and egg specific gravity (P=0.001) were lowest, and the egg yolk color was lightest (P=0.087) at wk 5, the peak of infestation. At wk 5 and 7, more than 65% of the hens had red skin and more than 75% had scabs on the vent; in addition more than 84% had grey-black vent feathers. There were no effects of infestation on comb color, comb temperature, feather cover, BW, or eggshell thickness. It was concluded that infestation with NFM has negative effects on interior egg quality and hen integument. A decrease in H/L ratio was also observed at the peak of infestation. However, the effects of NFM on the immune system are unclear, and H/L ratio might not be a good stress measure in hens highly infested with NFM.

  19. The effect of northern fowl mite (Ornithonyssus sylviarum) infestation on hen physiology, physical condition, and egg quality.

    PubMed

    Vezzoli, Giuseppe; King, Annie J; Mench, Joy A

    2016-05-01

    The northern fowl mite (NFM),Ornithonyssus sylviarum, is the most common ectoparasite of laying hens in North America. Infestation can cause a reduction in egg production, egg weights, and feed conversion efficiency. However, there is a lack of information on the effects of NFM on hen physiology, physical condition, and egg quality. Singly caged beak-trimmed White Leghorn hens (N=32) were infested with mites at 25 wk of age. The condition of each hen was assessed at wk 0 (infestation) and wk 5 and 7 post-infestation to determine comb temperatures and feather, skin, and comb condition. Heterophil-lymphocyte (H/L) ratios and body weight (BW) were evaluated at wk 0 and wk 1, 3, 5, and 7 post-infestation. Egg weight, egg specific gravity, yolk color, Haugh unit (HU), and eggshell thickness were determined prior to infestation (wk -1) and at 1, 3, 5, and 7 wk post-infestation. The H/L ratio (P<0.0001), HU (P<0.0001), and egg specific gravity (P=0.001) were lowest, and the egg yolk color was lightest (P=0.087) at wk 5, the peak of infestation. At wk 5 and 7, more than 65% of the hens had red skin and more than 75% had scabs on the vent; in addition more than 84% had grey-black vent feathers. There were no effects of infestation on comb color, comb temperature, feather cover, BW, or eggshell thickness. It was concluded that infestation with NFM has negative effects on interior egg quality and hen integument. A decrease in H/L ratio was also observed at the peak of infestation. However, the effects of NFM on the immune system are unclear, and H/L ratio might not be a good stress measure in hens highly infested with NFM. PMID:26944982

  20. The influence of living conditions on adolescent girls’ health

    PubMed Central

    Sundler, Annelie Johansson; Ekebergh, Margaretha

    2012-01-01

    Adolescence is described by the Swedish National Board of Health and Welfare as the healthiest period in life. However, adolescent girls differ in that they self-report that their health decreases with age. The aim of this hermeneutical study was to describe the meaning of living conditions in relation to adolescent girls’ health. Guided by principles of reflective lifeworld research, 15 interviews with adolescent girls were analysed. The result section consists of four narratives with their existential interpretations illustrating different ways of approaching living conditions and their meaning for health and well-being. The narratives are: Approaching everyday life in a balanced way—feeling harmonious; approaching everyday life with ambiguity—feeling confused; approaching everyday life as an intellectual project—striving for control; approaching everyday life as a struggle—feeling forlorn. In addition, a comprehensive understanding was developed by using the lifeworld dimensions: lived body, lived room, lived time, and lived relations. These dimensions may deepen the understanding of important parts of those living conditions which are meaningful for the girls’ health and well-being. By using the dimensions, complex living conditions have been explored and the meaning of different parts clarified. The girls’ thoughts and feelings are often ambiguous and sometimes contradictory, depending on the situation. The health of adolescent girls needs to be understood against the background of their experiences of living conditions. One way to support their health and well-being seems to be to supply them with forums where they can talk about their living conditions. PMID:23237626

  1. Use of color maps and wavelet coherence to discern seasonal and interannual climate influences on streamflow variability in northern catchments

    NASA Astrophysics Data System (ADS)

    Carey, Sean K.; Tetzlaff, Doerthe; Buttle, Jim; Laudon, Hjalmar; McDonnell, Jeff; McGuire, Kevin; Seibert, Jan; Soulsby, Chris; Shanley, Jamie

    2013-10-01

    The higher midlatitudes of the northern hemisphere are particularly sensitive to change due to the important role the 0°C isotherm plays in the phase of precipitation and intermediate storage as snow. An international intercatchment comparison program called North-Watch seeks to improve our understanding of the sensitivity of northern catchments to change by examining their hydrological and biogeochemical variability and response. Here eight North-Watch catchments located in Sweden (Krycklan), Scotland (Girnock and Strontian), the United States (Sleepers River, Hubbard Brook, and HJ Andrews), and Canada (Dorset and Wolf Creek) with 10 continuous years of daily precipitation and runoff data were selected to assess daily to seasonal coupling of precipitation (P) and runoff (Q) using wavelet coherency, and to explore the patterns and scales of variability in streamflow using color maps. Wavelet coherency revealed that P and Q were decoupled in catchments with cold winters, yet were strongly coupled during and immediately following the spring snowmelt freshet. In all catchments, coupling at shorter time scales occurred during wet periods when the catchment was responsive and storage deficits were small. At longer time scales, coupling reflected coherence between seasonal cycles, being enhanced at sites with enhanced seasonality in P. Color maps were applied as an alternative method to identify patterns and scales of flow variability. Seasonal versus transient flow variability was identified along with the persistence of that variability on influencing the flow regime. While exploratory in nature, this intercomparison exercise highlights the importance of climate and the 0°C isotherm on the functioning of northern catchments.

  2. Influencing Children's Pregambling Game Playing via Conditional Discrimination Training

    ERIC Educational Resources Information Center

    Johnson, Taylor E.; Dixon, Mark R.

    2009-01-01

    Past research has demonstrated a transformation of stimulus functions under similar conditions using gambling tasks and adults (e.g., Zlomke & Dixon, 2006), and the present study attempted to extend this research. Experimenters exposed 7 children (ages 7 to 10 years) to a simulated board game with concurrently available dice differing only by…

  3. INFLUENCE OF PH AND REDOX CONDITIONS ON COPPER LEACHING

    EPA Science Inventory

    Leaching behavior of metals from a mineral processing waste at varying pH and redox conditions was studies. Effect of combinations of pH and Eh on leaching of copper is described. Leaching of copper was found to be dependent on both pH and Eh. Higher concentrations of Cu were ...

  4. Influence of pavement condition on horizontal curve safety.

    PubMed

    Buddhavarapu, Prasad; Banerjee, Ambarish; Prozzi, Jorge A

    2013-03-01

    Crash statistics suggest that horizontal curves are the most vulnerable sites for crash occurrence. These crashes are often severe and many involve at least some level of injury due to the nature of the collisions. Ensuring the desired pavement surface condition is one potentially effective strategy to reduce the occurrence of severe accidents on horizontal curves. This study sought to develop crash injury severity models by integrating crash and pavement surface condition databases. It focuses on developing a causal relationship between pavement condition indices and severity level of crashes occurring on two-lane horizontal curves in Texas. In addition, it examines the suitability of the existing Skid Index for safety maintenance of two-lane curves. Significant correlation is evident between pavement condition and crash injury severity on two-lane undivided horizontal curves in Texas. Probability of a crash becoming fatal is appreciably sensitive to certain pavement indices. Data suggested that road facilities providing a smoother and more comfortable ride are vulnerable to severe crashes on horizontal curves. In addition, the study found that longitudinal skid measurement barely correlates with injury severity of crashes occurring on curved portions. The study recommends exploring the option of incorporating lateral friction measurement into Pavement Management System (PMS) databases specifically at curved road segments.

  5. Influence of pavement condition on horizontal curve safety.

    PubMed

    Buddhavarapu, Prasad; Banerjee, Ambarish; Prozzi, Jorge A

    2013-03-01

    Crash statistics suggest that horizontal curves are the most vulnerable sites for crash occurrence. These crashes are often severe and many involve at least some level of injury due to the nature of the collisions. Ensuring the desired pavement surface condition is one potentially effective strategy to reduce the occurrence of severe accidents on horizontal curves. This study sought to develop crash injury severity models by integrating crash and pavement surface condition databases. It focuses on developing a causal relationship between pavement condition indices and severity level of crashes occurring on two-lane horizontal curves in Texas. In addition, it examines the suitability of the existing Skid Index for safety maintenance of two-lane curves. Significant correlation is evident between pavement condition and crash injury severity on two-lane undivided horizontal curves in Texas. Probability of a crash becoming fatal is appreciably sensitive to certain pavement indices. Data suggested that road facilities providing a smoother and more comfortable ride are vulnerable to severe crashes on horizontal curves. In addition, the study found that longitudinal skid measurement barely correlates with injury severity of crashes occurring on curved portions. The study recommends exploring the option of incorporating lateral friction measurement into Pavement Management System (PMS) databases specifically at curved road segments. PMID:23298704

  6. Impact of winter oceanographic conditions on zooplankton abundance in northern Adriatic with implications on Adriatic anchovy stock prognosis

    NASA Astrophysics Data System (ADS)

    Kraus, Romina; Supić, Nastjenjka; Lučić, Davor; Njire, Jakica

    2015-12-01

    Anchovy, Engraulis encrasicolus (L.), is commercially one of the most important Adriatic small pelagic fish. Despite the prevailing oligotrophication trend in the northern Adriatic (NA), the anchovy catch increased after 2000, coinciding with an increased number of the winter type A occurrences, when Po River waters are favoured to spread across the NA. Namely, winter type A is characterised by conditions resulting with Po River waters spreading across the NA along with salinity decrease. On the contrary, in winters of type B, salinity is high. We hypothesized in previous paper, based on correlation between circulation patterns and phytoplankton with anchovy catch, that excess feeding of anchovy in this winter pre-spawning period (February) can lead to increased amounts of the anchovy eggs two months later and subsequently to the total fish catch of the same year. In this paper, we investigate in more details and based on longer time series the relation between anchovy catch and winter circulation patterns of the NA. Additionally, we studied the association between anchovy catch and zooplankton, as anchovy is predominantly zooplanktivorous. We found that zooplankton abundances in winters of A type enhance and that ciliates play an important role in the NA anchovy food web and enrichment of the region with anchovy. Finally, the results of our investigation might in time represent the basics for a sustainable anchovy management in the Adriatic Sea as they enable the development of prediction models of the anchovy stock.

  7. Displacement and HIV: Factors Influencing Antiretroviral Therapy Use by Ethnic Shan Migrants in Northern Thailand.

    PubMed

    Murray, Jordan K; DiStefano, Anthony S; Yang, Joshua S; Wood, Michele M

    2016-01-01

    Migrant populations face increased HIV vulnerabilities, including limited access to antiretroviral therapy. Civil conflict in Myanmar has displaced thousands of people from the minority Shan ethnic group into northern Thailand, where they bear a disproportionate HIV burden. To identify barriers and facilitators of antiretroviral therapy use in this population, we conducted a rapid ethnographic assessment and case study with a clinical sample of Shan migrants receiving treatment for HIV in a district hospital in Chiang Mai, Thailand, Thai nurses providing their care, and health care administrators (n = 23). Barriers included fears of arrest and deportation, communication difficulties, perceived social marginalization, limited HIV knowledge, and lack of finances. Facilitating factors included hospital-based migrant registration services and community outreach efforts involving support group mobilization, referral practices, and radio broadcasts. These findings provided a contextualized account to inform policies, community interventions, and nursing practice to increase treatment access for minority migrant groups. PMID:27188762

  8. Polar Northern Hemisphere Middle Atmospheric Influence due to Energetic Particle Precipitation in January 2005

    NASA Astrophysics Data System (ADS)

    Jackman, Charles; Randall, Cora E.; Fang, Xiaohua; Bernath, Peter F.; Funke, Bernd; Lopez-Puertas, Manuel; Versick, Stefan; Stiller, Gabriele P.; Tylka, Allan J.; Marsh, Daniel R.; Vitt, Francis M.; Garcia, Rolando R.; Fleming, Eric L.

    Solar eruptions and geomagnetic activity led to energetic particle precipitation in early 2005, primarily during the January 16-21 period. Production of OH and destruction of ozone have been documented due to the enhanced energetic solar proton flux in January 2005 [e.g., Ver-ronen et al., Geophys Res. Lett., 33, L24811, doi:10.1029/2006GL028115, 2006; Seppala et al., Geophys. Res. Lett., 33, L07804, doi:10.1029/2005GL025571, 2006]. These solar pro-tons as well as precipitating electrons also led to the production of NOx (NO, NO2). Our simulations with the Whole Atmosphere Community Climate Model (WACCM) show that NOx is enhanced by 20-50 ppbv in the polar Northern Hemisphere middle mesosphere ( 60-70 km) by Jan. 18. Both the SCISAT-1 Atmospheric Chemistry Experiment (ACE) NOx mea-surements and Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) nighttime NO2 observations show large increases during this period, in reasonable agreement with WACCM predictions. Such enhancements are considerable for the mesosphere and led to simulated increases in polar Northern Hemisphere upper stratospheric odd nitrogen (NOy) of 2-5 ppbv into February 2005. The largest ground level enhancement of solar cycle 23 occurred on Jan. 20, 2005 with a neutron monitor increase of about 270 percent [Gopalswamy et al., 29th Int. Cosmic Ray Conf., Pune, 00, 101-104, 2005]. We found that protons of energies 300 to 20,000 MeV, not normally included in our computations, led to enhanced stratospheric NOy of less than 1 percent as a result of this GLE. The atmospheric impact of precipitating middle energy electrons (30-2,500 keV) during the Jan. 16-21, 2005 period is also of interest, and an effort is ongoing to include these in WACCM computations. This presentation will show both short-and longer-term changes due to the January 2005 energetic particle precipitation.

  9. Can environmental conditions experienced in early life influence future generations?

    PubMed Central

    Burton, Tim; Metcalfe, Neil B.

    2014-01-01

    The consequences of early developmental conditions for performance in later life are now subjected to convergent interest from many different biological sub-disciplines. However, striking data, largely from the biomedical literature, show that environmental effects experienced even before conception can be transmissible to subsequent generations. Here, we review the growing evidence from natural systems for these cross-generational effects of early life conditions, showing that they can be generated by diverse environmental stressors, affect offspring in many ways and can be transmitted directly or indirectly by both parental lines for several generations. In doing so, we emphasize why early life might be so sensitive to the transmission of environmentally induced effects across generations. We also summarize recent theoretical advancements within the field of developmental plasticity, and discuss how parents might assemble different ‘internal’ and ‘external’ cues, even from the earliest stages of life, to instruct their investment decisions in offspring. In doing so, we provide a preliminary framework within the context of adaptive plasticity for understanding inter-generational phenomena that arise from early life conditions. PMID:24807254

  10. Methods and background characteristics of the TOHNN study: a population-based study of oral health conditions in northern Norway

    PubMed Central

    Holde, Gro Eirin; Oscarson, Nils; Tillberg, Anders; Marstrander, Peter; Jönsson, Birgitta

    2016-01-01

    Objectives The aim of the Tromstannen – Oral Health in Northern Norway (TOHNN) study was to investigate oral health and dental-related diseases in an adult population. This article provides an overview of the background of the study and a description of the sample characteristics and methods employed in data collection. Study design Cross-sectional population-based study including a questionnaire and clinical dental examination. Methods A randomly selected sample of 2,909 individuals (20–79 years old) drawn from the population register was invited to participate in the study. The data were collected between October 2013 and November 2014 in Troms County in northern Norway. The questionnaire focused on oral health-related behaviours and attitudes, oral health-related quality of life, sense of coherence, dental anxiety and symptoms from the temporomandibular joint. The dental examinations, including radiographs, were conducted by 11 dental teams in 5 dental offices. The examination comprised of registration of dental caries, full mouth periodontal status, temporomandibular disorders, mucosal lesions and height and weight. The participants were grouped by age (20–34, 35–49, 50–64 and 65–79) and ethnicity (Norwegian, Sámi, other European and other world). Results From the original sample of 2,909 individuals, 1,986 (68.3%) people participated, of whom 1,019 (51.3%) were women. The highest attendance rate was among women 20–34 years old (80.3%) and the lowest in the oldest age group of women (55.4%). There was no difference in response rate between rural and urban areas. There was a positive correlation between population size and household gross income (p < 0.001) and education level (p < 0.001). The majority of Sámi resided in smaller municipalities. In larger cities, most participants used private dental health care services, whereas, in rural areas, most participants used the public dental health care service. Conclusion The TOHNN study has the

  11. The Influence of fold and fracture development on reservoir behavior of the Lisburne Group of northern Alaska

    SciTech Connect

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen: Michael T. Whalen; Paul Atkinson; Joseph Brinton; Thang Bui; Margarete Jadamec; Alexandre Karpov; John Lorenz; Michelle M. McGee; T.M. Parris; Ryan Shackleton

    2004-07-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is folded and thrust faulted where it is exposed throughout the Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. Symmetrical detachment folds characterize the Lisburne in the northeastern Brooks Range. In contrast, Lisburne in the main axis of the Brooks Range is deformed into imbricate thrust sheets with asymmetrical hangingwall anticlines and footwall synclines. The Continental Divide thrust front separates these different structural styles in the Lisburne and also marks the southern boundary of the northeastern Brooks Range. Field studies were conducted for this project during 1999 to 2001 in various locations in the northeastern Brooks Range and in the vicinity of Porcupine Lake, immediately south of the Continental Divide thrust front. Results are summarized below for the four main subject areas of the study.

  12. Analysis of weather condition influencing fire regime in Italy

    NASA Astrophysics Data System (ADS)

    Bacciu, Valentina; Masala, Francesco; Salis, Michele; Sirca, Costantino; Spano, Donatella

    2014-05-01

    Fires have a crucial role within Mediterranean ecosystems, with both negative and positive impacts on all biosphere components and with reverberations on different scales. Fire determines the landscape structure and plant composition, but it is also the cause of enormous economic and ecological damages, beside the loss of human life. In addition, several authors are in agreement suggesting that, during the past decades, changes on fire patterns have occurred, especially in terms of fire-prone areas expansion and fire season lengthening. Climate and weather are two of the main controlling agents, directly and indirectly, of fire regime influencing vegetation productivity, causing water stress, igniting fires through lightning, or modulating fire behavior through wind. On the other hand, these relationships could be not warranted in areas where most ignitions are caused by people (Moreno et al. 2009). Specific analyses of the driving forces of fire regime across countries and scales are thus still required in order to better anticipate fire seasons and also to advance our knowledge of future fire regimes. The objective of this work was to improve our knowledge of the relative effects of several weather variables on forest fires in Italy for the period 1985-2008. Meteorological data were obtained through the MARS (Monitoring Agricultural Resources) database, interpolated at 25x25 km scale. Fire data were provided by the JRC (Join Research Center) and the CFVA (Corpo Forestale e di Vigilanza Ambientale, Sardinia). A hierarchical cluster analysis, based on fire and weather data, allowed the identification of six homogeneous areas in terms of fire occurrence and climate (pyro-climatic areas). Two statistical techniques (linear and non-parametric models) were applied in order to assess if inter-annual variability in weather pattern and fire events had a significant trend. Then, through correlation analysis and multi-linear regression modeling, we investigated the

  13. Northern Hemisphere Atmospheric Influence of the Solar Proton Events and Ground Level Enhancement in January 2005

    NASA Technical Reports Server (NTRS)

    Jackman, C. H.; Marsh, D. R.; Vitt, F. M.; Roble, R. G.; Randall, C. E.; Bernath, P. F.; Funke, B.; Lopez-Puertas, M.; Versick, S.; Stiller, G. P.; Tylka, A. J.; Fleming, E. L.

    2011-01-01

    Solar eruptions in early 2005 led substantial barrage of charged particles on the Earth's atmosphere during the January 16-21 period. Proton fluxes were greatly increased during these several days and led to the production ofHO(x)(H, OH, BO2)and NO(x)(N, NO, NO2), which then caused the destruction of ozone. We focus on the Northern polar region, where satellite measurements and simulations with the Whole Atmosphere Community Climate Model (WACCM3) showed large enhancements in mesospheric HO(x) and NO(x) constituents, and associated ozone reductions, due 10 these solar proton events (SPEs). The WACCM3 simulations show enhanced short-lived OH throughout the mesosphere in the 60-82.5degN latitude band due to the SPEs for most days in the Jan.16-2l,2005 period, in reasonable agreement with the Aura Microwave Limb Sounder (MLS) measurements. Mesospheric HO2 is also predicted to be increased by the SPEs, however, the modeled HO2 results are somewhat larger than the MLS measurements. These HO(x) enhancements led to huge predicted and MLS-measured ozone decreases of greater than 40% throughout most of the Northern polar mesosphere during the SPE period. Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) measurements of hydrogen peroxide (H2O2) show increases throughout the stratosphere with highest enhancements of about 60 ppt y in the lowermost mesosphere over the Jan. 16-18, 2005 period due to the solar protons. WACCM3 predictions indicate H2O2 enhancements over the same time period of more than twice that amount. Measurements of nitric acid (HNO3) by both MLS and MIPAS show an increase of about 1 ppbv above background levels in the upper stratosphere during January 16-29, 2005. WACCM3 simulations show only minuscule HNO3 changes in the upper stratosphere during this time period. However due to the small loss rates during winter, polar mesospheric enhancements of NO(x) are computed to be greater than 50 ppbv during the SPE period. Computed NO

  14. Polar Northern Hemisphere Middle Atmospheric Influence due to Energetic Particle Precipitation in January 2005

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.

    2010-01-01

    Solar eruptions and geomagnetic activity led to energetic particle precipitation in early 2005, primarily during the January 16-21 period. Production of OH and destruction of ozone have been documented due to the enhanced energetic solar proton flux in January 2005 [e.g., Verronen et al., Geophys. Res. Lett.,33,L24811,doi:10.1029/2006GL028115, 2006; Seppala et al., Geophys. Res. Lett.,33,L07804, doi:10.1029/2005GL025571,2006]. These solar protons as well as precipitating electrons also led to the production of NO(x) (NO, NO2). Our simulations with the Whole Atmosphere Community Climate Model (WACCM) show that NO(x) is enhanced by 20-50 ppbv in the polar Northern Hemisphere middle mesosphere (approx.60-70 km) by January 18. Both the SCISAT-1 Atmospheric Chemistry Experiment (ACE) NO(x) measurements and Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIP AS) nighttime NO2 observations show large increases during this period, in reasonable agreement with WACCM predictions. Such enhancements are considerable for the mesosphere and led to simulated increases in polar Northern Hemisphere upper stratospheric odd nitrogen (NO(y)) of2-5 ppbv into February 2005. The largest ground level enhancement (GLE) of solar cycle 23 occurred on January 20, 2005 with a neutron monitor increase of about 270 percent [Gopalswamy et al., 29th International Cosmic Ray Conference, Pune,00,101-104,2005]. We found that protons of energies 300 to 20,000 MeV, not normally included in our computations, led to enhanced stratospheric NO(y) of less than 1 percent as a result of this GLE. The atmospheric impact of precipitating middle energy electrons (30-2,500 keV) during the January 16-21, 2005 period is also of interest, and an effort is ongoing to include these in WACCM computations. This presentation will show both short- and longer-term changes due to the January 2005 energetic particle precipitation.

  15. Comparing Observed Hurricane Conditions Against Potential Future Climate Change Influences

    NASA Astrophysics Data System (ADS)

    Graham, W. D.

    2012-12-01

    Climate Adaptation Science Investigators: (CASI) is to advance and apply NASA's scientific expertise and products to develop climate adaptation strategies that support NASA's overall mission by minimizing risks to each center's operations, physical assets, and personnel. Using Hurricane Katrina observations as a baseline, we use ADCIRC to model surge extent with simple modifications of the storm track. We examine two time now (T0) scenarios of present-day climatological factors: 1) translating the 2005 path 7 km west; and 2) rotating the approach angle from due-north to WNW. Second, we examine two future time scenarios (TX) by infusing climate change conditions, such as sea level rise and increased storm intensity, into a T0 baseline to assess future impacts. The primary goal of this work entails planning and protecting NASA assets and infrastructure. The adjacent communities, state and local emergency managers, gain benefit from this NASA work as data and analysis includes the surrounding geography.

  16. Assessment of the potential for hydro-solidarity within plural legal conditions of traditional irrigation systems in northern Tanzania

    NASA Astrophysics Data System (ADS)

    Kemerink, J. S.; Ahlers, R.; van der Zaag, P.

    Competition over water resources and related disputes over water are inherently local and context-specific in their manifestations. In Makanya catchment, located in the mid-reaches of the Pangani river basin in northern Tanzania, competition over water is apparent and with increased demands for water disputes are likely to become fiercer in the near future. Negotiations between upstream and downstream users at various levels in the catchment have resulted in water sharing arrangements or are still on-going while other negotiations seem to be stranded in impasses. Why in certain situations water sharing among users evolves, while in other cases mutual agreements can not be reached, is not yet well understood. Insight in the plural legal context in which water sharing arrangement among water users develop could set light on complex resource use and management realities as well as the ability of various water users to influence the negotiations over water. The hydro-solidarity concept is referred to as potential mechanism to reconcile conflicts over water. Hydro-solidarity promotes ethical dimensions as integral part of decision making and is assumed to be based on a universal set of commonly accepted norms and rules. Through analysis of the plural legal context in which water sharing arrangements among the smallholder farmers in the Makanya catchment develop, the paper explores the existence of ethical dimensions in decision making and their legitimacy. In this way the potential of the hydro-solidarity concept as mechanism to reconcile conflicts over water can be assessed in the context-specific plural reality. The paper concludes that, although ethical dimensions in decision making in the Makanya catchment exist, the hydro-solidarity concept as mechanism to reconcile disputes over water has limited potential as long as it does not embrace the plural reality. The authors argue that, instead of searching for a universal normative order, legal plural analysis can serve

  17. Influence of hydrologic processes on reproduction of the introduced bivalve Potamocorbula amurensis in northern San Francisco Bay, California

    USGS Publications Warehouse

    Parchaso, F.; Thompson, J.K.

    2002-01-01

    Monthly censusing of reproductive condition of the Asian clam Potamocorbula amurensis at four sites in northern San Francisco Bay over a 9-yr period revealed year-to-year differences in local reproductive activity that are associated with patterns of hydrologic variability. Between 1989 and 1992, Northern California experienced a drought, whereas the period between 1993 and 1998 was marked by a mix of wet and dry years. We took advantage of the extreme year-to-year differences to examine reproductive responses to river inflow patterns. Populations of P. amurensis at the upstream sites in Suisun Bay and Carquinez Strait were more reproductively active during wet years than dry years. Conversely, at the downstream site in San Pablo Bay, the population was more reproductively active during dry years than wet years. We suggest that the different reproductive patterns observed reflect the clam's response to different sources of food. During wet years, organic matter from the rivers augments food supplies in Suisun Bay. During dry years, when inflow into the San Francisco Bay Estuary from the rivers is reduced, water transported from the adjacent ocean into the estuary as far as San Pablo Bay provides a supplemental food supply for the local production. The populations take advantage of these spatially distinct food supplies by initiating and maintaining local reproductive activity. We conclude that the ability of P. amurensis to consume and use various types of food to regulate its reproductive activity is part of the reason for its success as an invasive species.

  18. DISTRIBUTION AND COMPOSITION OF DISSOLVED AND PARTICULATE ORGANIC CARBON IN NORTHERN SAN FRANCISCO BAY DURING LOW FRESHWATER FLOW CONDITIONS

    EPA Science Inventory

    The distribution of organic matter was studied in northern San Francisco Bay monthly through spring and summer 1996 along the salinity gradient from the Sacramento River to Central Bay. Dissolved constituents included monosaccharides (MONO), total carbohydrates (TCHO), dissolved ...

  19. Land use influences arbuscular mycorrhizal fungal communities in the farming-pastoral ecotone of northern China.

    PubMed

    Xiang, Dan; Verbruggen, Erik; Hu, Yajun; Veresoglou, Stavros D; Rillig, Matthias C; Zhou, Wenping; Xu, Tianle; Li, Huan; Hao, Zhipeng; Chen, Yongliang; Chen, Baodong

    2014-12-01

    We performed a landscape-scale investigation to compare the arbuscular mycorrhizal fungal (AMF) communities between grasslands and farmlands in the farming-pastoral ecotone of northern China. AMF richness and community composition were examined with 454 pyrosequencing. Structural equation modelling (SEM) and multivariate analyses were applied to disentangle the direct and indirect effects (mediated by multiple environmental factors) of land use on AMF. Land use conversion from grassland to farmland significantly reduced AMF richness and extraradical hyphal length density, and these land use types also differed significantly in AMF community composition. SEM showed that the effects of land use on AMF richness and hyphal length density in soil were primarily mediated by available phosphorus and soil structural quality. Soil texture was the strongest predictor of AMF community composition. Soil carbon, nitrogen and soil pH were also significantly correlated with AMF community composition, indicating that these abiotic variables could be responsible for some of the community composition differences among sites. Our study shows that land use has a partly predictable effect on AMF communities across this ecologically relevant area of China, and indicates that high soil phosphorus concentrations and poor soil structure are particularly detrimental to AMF in this fragile ecosystem.

  20. Barred owls and landscape attributes influence territory occupancy of northern spotted owls

    PubMed Central

    Sovern, Stan G; Forsman, Eric D; Olson, Gail S; Biswell, Brian L; Taylor, Margaret; Anthony, Robert G

    2014-01-01

    We used multi-season occupancy analyses to model 2 fates of northern spotted owl territories in relation to habitat amount, habitat fragmentation, and the presence of barred owls in Washington State, USA, 1989–2005. Local colonization is the probability a territory unoccupied by a spotted owl in year i would be occupied in year i + 1, and local extinction is the probability a territory that was occupied by a spotted owl in year i would be unoccupied in year i + 1. We found a negative relationship between local extinction probability and amount of late-seral forest edge. We found a negative relationship between colonization probability and the number of late-seral forest patches (higher fragmentation), and a negative relationship between colonization probability and the amount of non-habitat within 600 m of a spotted owl territory center (Akaike weight = 0.59). The presence of barred owls was positively related to extinction probability and negatively related to detection probability of spotted owls. The negative relationship between presence of barred owls and detectability of spotted owls indicated that spotted owls could be modifying their calling behavior in the presence of barred owls. The positive relationship between barred owl detections and local extinction probability suggests that because of competition with barred owls, spotted owls are being displaced. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. PMID:25558093

  1. Does predation risk influence habitat use by northern redbelly dace Phoxinus eos at different spatial scales?

    PubMed

    Dupuch, A; Magnan, P; Bertolo, A; Dill, L M; Proulx, M

    2009-05-01

    This study investigated the relationship between spatial variations in predation risk and abundance of northern redbelly dace Phoxinus eos at both macroscale (littoral v. pelagic zones) and microscale (structured v. open water habitats in the littoral zone) of Canadian Shield lakes. Minnow traps were placed in both structured and open water habitats in the littoral zone of 13 Canadian Shield lakes, and estimates of the relative predation risk of P. eos in both the pelagic and the littoral zones were obtained from tethering experiments. Results showed that (1) the mean abundance of P. eos in the littoral zone was positively correlated with the relative predation risk in the pelagic zone, (2) P. eos preferentially used structured over open water habitats in the littoral zone and (3) this preference was not related to the relative predation risk in the littoral zone but decreased as the relative predation risk increased in the pelagic zone. At the lake level, these results support the hypothesis that P. eos enter the littoral zone to avoid pelagic piscivores. At the littoral zone level, the results do not necessarily contradict the widely accepted view that P. eos preferentially use structured over open habitats to reduce their predation risk, but suggest that flexibility in antipredator tactics (e.g. shelter use v. shoaling) could explain the spatial distribution of P. eos between structured and open water habitats. PMID:20735640

  2. Geographical, linguistic, and cultural influences on genetic diversity: Y-chromosomal distribution in Northern European populations.

    PubMed

    Zerjal, T; Beckman, L; Beckman, G; Mikelsaar, A V; Krumina, A; Kucinskas, V; Hurles, M E; Tyler-Smith, C

    2001-06-01

    We analyzed 10 Y-chromosomal binary markers in 363 males from 8 populations in Northern Europe and 5 Y microsatellites in 346 of these individuals. These populations can be grouped according to cultural, linguistic, or geographical criteria, and the groupings are different in each case. We can therefore ask which criterion best corresponds to the distribution of genetic variation. In an AMOVA analysis using the binary markers, 13% of the Y variation was found between populations, indicating a high level of differentiation within this small area. No significant difference was seen between the traditionally nomadic Saami and the neighboring, historically farming, populations. When the populations were divided into Uralic speakers and Indo-European speakers, 8% of the variation was found between groups, but when they were divided according to geographical location, 14% of the variation was between groups. Geographical factors have thus been the most important in limiting gene flow between these populations, but linguistic differences have also been important in the east.

  3. Using supplemental food and its influence on survival of northern bobwhite (Colinus virginianus)

    USGS Publications Warehouse

    Townsend, D.E.; Lochmiller, R.L.; DeMaso, S.J.; Leslie, David M.; Peoples, A.D.; Scott, A C.; Parry, E.S.

    2000-01-01

    Biologists have debated the effectiveness of supplemental feeders as a management tool for the northern bobwhite (Colinus virginianus), but few extensive evaluations have been conducted. We examined 783 crops from harvested bobwhites during 1992-1996 to determine effects of climatic stress in winter on use of supplemental feeders and their impact on survival rate in winter. Crops of bobwhites harvested from areas with supplemental feeders contained 28.2% supplemental food compared with 5.5% (P<0.001) for those from areas without supplemental feeders. Winter climate was not a significant predictor of the proportional use of supplemental feeders. Rates of winter survival were greater on areas with supplemental feeders compared with non-supplemented areas in winters 1992-1993 (P=0.001) and 1993-1994 (P=0.002), but in 1994-1995, rates were greater on nonsupplemented areas (P=0.032). Cause-specific mortality rates indicated that supplemental feeders did not predispose bobwhites to hunter harvest or predators. Results suggested that bobwhites can gain nutritional benefits from supplemental feeders during times of severe winter stress.

  4. Does predation risk influence habitat use by northern redbelly dace Phoxinus eos at different spatial scales?

    PubMed

    Dupuch, A; Magnan, P; Bertolo, A; Dill, L M; Proulx, M

    2009-05-01

    This study investigated the relationship between spatial variations in predation risk and abundance of northern redbelly dace Phoxinus eos at both macroscale (littoral v. pelagic zones) and microscale (structured v. open water habitats in the littoral zone) of Canadian Shield lakes. Minnow traps were placed in both structured and open water habitats in the littoral zone of 13 Canadian Shield lakes, and estimates of the relative predation risk of P. eos in both the pelagic and the littoral zones were obtained from tethering experiments. Results showed that (1) the mean abundance of P. eos in the littoral zone was positively correlated with the relative predation risk in the pelagic zone, (2) P. eos preferentially used structured over open water habitats in the littoral zone and (3) this preference was not related to the relative predation risk in the littoral zone but decreased as the relative predation risk increased in the pelagic zone. At the lake level, these results support the hypothesis that P. eos enter the littoral zone to avoid pelagic piscivores. At the littoral zone level, the results do not necessarily contradict the widely accepted view that P. eos preferentially use structured over open habitats to reduce their predation risk, but suggest that flexibility in antipredator tactics (e.g. shelter use v. shoaling) could explain the spatial distribution of P. eos between structured and open water habitats.

  5. Influence of variations in extratropical wintertime teleconnections on Northern Hemisphere temperature

    SciTech Connect

    Hurrell, J.W.

    1996-03-15

    Pronounced changes in the wintertime atmospheric circulation have occurred since the mid-1970s over the ocean basins of the Northern Hemisphere, and these changes have had a profound effect on surface temperatures. The variations over the North Atlantic are related to changes in the North Atlantic Oscillation (NAO), while the changes over the North Pacific are linked to the tropics and involve variations in the Aleutian low with teleconnections downstream over North America. Multivariate linear regression is used to show that nearly all of the cooling in the northwest Atlantic and the warming across Europe and downstream over Eurasia since the mid-1970s results from the changes in the NAO, and the NAO accounts for 31% of the hemispheric interannual variance over the past 60 winters. Over the Pacific basin and North America, the temperature anomalies result in part from tropical forcing associated with the El Nino-Southern Oscillation phenomenon but with important feedbacks in the extratropics. The changes in circulation over the past two decades have resulted in a surface temperature anomaly pattern of warmth over the continents and coolness over the oceans. This pattern of temperature change has amplified the observed hemispheric-averaged warming because of it interaction with land and ocean; temperature changes are larger over land compared to the oceans because of the small heat capacity of the former. 13 refs., 5 fig., 2 tab.

  6. Seasonal weather influences on yearling beef steer production in C3-dominated Northern Great Plains rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the face of an increasingly variable climate, long-term cattle weight gain datasets are rare, yet invaluable, for determining site-specific influences of seasonal weather patterns on cattle production. Here, we present a long-term (1936 – 2005) yearling Hereford steer data set collected at the No...

  7. Seasonal weather influences on yearling steer beef production in C3-dominated Northern Great Plains rangeland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the face of an increasingly variable climate, long-term cattle weight gain datasets are rare, yet invaluable, for determining site-specific influences of seasonal weather patterns on cattle production. Here, we present a long-term (1936 – 2005) yearling Hereford steer data set collected at the No...

  8. Factors that influence the hydrologic recovery of wetlands in the Northern Tampa Bay area, Florida

    USGS Publications Warehouse

    Metz, P.A.

    2011-01-01

    Low permeability sediments and the absence of karst features underlying the wetlands had a positive influence on the wetland recovery following the reductions in groundwater withdrawals. In these settings, intact low permeability subsurface layers help maintain water within and beneath the wetland, and limit the downward leakage potential to the Upper Floridan aquifer. For wetlands in these settings

  9. Sample storage conditions significantly influence faecal microbiome profiles

    PubMed Central

    Choo, Jocelyn M; Leong, Lex EX; Rogers, Geraint B

    2015-01-01

    Sequencing-based studies of the human faecal microbiota are increasingly common. Appropriate storage of sample material is essential to avoid the introduction of post-collection bias in microbial community composition. Rapid freezing to −80 °C is commonly considered to be best-practice. However, this is not feasible in many studies, particularly those involving sample collection in participants’ homes. We determined the extent to which a range of stabilisation and storage strategies maintained the composition of faecal microbial community structure relative to freezing to −80 °C. Refrigeration at 4 °C, storage at ambient temperature, and the use of several common preservative buffers (RNAlater, OMNIgene.GUT, Tris-EDTA) were assessed relative to freezing. Following 72 hours of storage, faecal microbial composition was assessed by 16 S rRNA amplicon sequencing. Refrigeration was associated with no significant alteration in faecal microbiota diversity or composition. However, samples stored using other conditions showed substantial divergence compared to −80 °C control samples. Aside from refrigeration, the use of OMNIgene.GUT resulted in the least alteration, while the greatest change was seen in samples stored in Tris-EDTA buffer. The commercially available OMNIgene.GUT kit may provide an important alternative where refrigeration and cold chain transportation is not available. PMID:26572876

  10. Age at menarche: the influence of environmental conditions

    NASA Astrophysics Data System (ADS)

    Saar, E.; Shalev, C.; Dalal, I.; Sod-Moriah, U. A.

    1988-03-01

    Age at menarche was studied by the recollection method in two groups of Causasian Jewish high school girls, inhabitants of two towns in Israel, Safad and Elat. The two towns differ mainly in climatic conditions. The age at menarche was found to be significantly lower ( P<0.02) in the hot town of Elat than in the temperate town of Safad: 13.30±1.21 and 13.58±0.9 years, respectively (mean ±SD). A significant association was found between the age at menarche and the town in which the girls lived. Accordingly, in the hot town of Elat, the percentage of girls who had their first menstrual cycle by the age of 12 years and earlier, was more than double that of the girls in Safad (17.9% and 7.1%, respectively). It is concluded that the environmental temperature, with or without any possible interaction of humidity, is probably responsible for the tendency for an earlier onset of menarche in girls living in the hot town of Elat.

  11. Influence of Wall Conditioning on ADITYA Plasma Discharges

    NASA Astrophysics Data System (ADS)

    Tanna, R. L.; Jadeja, K. A.; Bhatt, S. B.; Bawankar, P. S.; Gupta, C. N.; Joisa, Y. S.; Atrey, P. K.; Manchanda, R.; Ramaiya, Nilam; Ghosh, J.; Raju, D.; Chattopadhyay, P. K.; Jha, R.; the Aditya Team

    2012-11-01

    ADITYA (R0 = 75 cm, a = 25 cm), an ohmically heated circular limiter tokamak is regularly being operated to carry out several experiments related to controlled thermonuclear fusion research. In recent operational campaign, various experiments have been carried out to enhance the discharge performance as well as improve the plasma parameters. A comparative plasma discharges study with SiC and Graphite limiter was carried out to increase the plasma heating and reduce runaways. Excellent plasma heating has been observed in many discharges using Graphite limiter. Good repeatability of low hard X-rays, high temperature discharges was obtained. The control of plasma impurities and hydrogen recycling is very much essential for high performance discharges. The wall conditioning in ADITYA tokamak is carried out by hydrogen glow discharge cleaning (GDC), Pulse discharge cleaning and electron cyclotron resonance (ECR) discharge cleaning techniques with and without lithium wall coating. GDC assisted Lithiumization was found to be the most effective technique for substantial reduction in Ha and low Z (CIII & O-I) impurities. The partial pressure of mass number 18 (H2O) and 28 (N2/C2H4/CO) were regularly monitored before plasma discharge operation. Furthermore, experiment on optimization of pulse gas feed was helped in reducing wall loading and recycling. However, hard X-rays suppression with the application of multiple gas puff has been successfully achieved during negative converter operation, which led to the extension of plasma pulse length up to ~ 250 ms. All the supporting facts and operation aspects are reported.

  12. How do climate and human impact affect Sphagnum peatlands under oceanic-continental climatic conditions? 2000 years of fire and hydrological history of a bog in Northern Poland

    NASA Astrophysics Data System (ADS)

    Marcisz, Katarzyna; Tinner, Willy; Colombaroli, Daniele; Kołaczek, Piotr; Słowiński, Michał; Fiałkiewicz-Kozieł, Barbara; Lamentowicz, Mariusz

    2014-05-01

    Climate change affects many natural processes and the same applies to human impact For instance climate change and anthropogenic activities may cause increased fire activity or change peatland dynamics. Currently it is still unknown how Sphagnum peatlands in the oceanic-continental transition zone of Poland may respond to combined effects of heat waves, drought and fire. The aim of the study was to reconstruct the last 2000 years palaeohydrology and fire history at Linje bog in Northern Poland. The main task was to determine the drivers of fire episodes, particularly to identify climatic and anthropogenic forcing. A two-meter peat core was extracted and subsampled with a high resolution. Micro- and macroscopic charcoal analyses were applied to determine past fire activity and the results compared with palaeohydrological reconstructions based on testate amoeba analysis. Palynological human indicators were used to reconstruct human activity. A depth-age model including 20 14C dates was constructed to calculate peat accumulation rates and charcoal influx. We hypothesised that: 1) fire frequency in Northern Poland was determined by climatic conditions (combination of low precipitation and heat waves), as reflected in peatland water table, and that 2) past fire episodes in the last millennium were intensified by human activity. Furthermore climate may have influenced human activity over harvest success and the carrying capacity. Our study shows that fire was important for the studied ecosystem, however, its frequency has increased in the last millennium in concomitance with land use activities. Landscape humanization and vegetation opening were followed by a peatland drying during the Little Ice Age (from ca. AD 1380). Similarly to other palaeoecological studies from Poland, Linje peatland possessed an unstable hydrology during the Little Ice Age. Increased fire episodes appeared shortly before the Little Ice Age and most severe fires were present in the time when

  13. Influence of meteorological conditions on RSV infection in Portugal

    NASA Astrophysics Data System (ADS)

    Oliveira-Santos, M.; Santos, J. A.; Soares, J.; Dias, A.; Quaresma, M.

    2016-04-01

    Acute viral bronchiolitis is a common cause for infant hospital admissions. Of all etiological agents, respiratory syncytial virus (RSV) is commonly the most frequent. The present study assesses relationships between atmospheric factors and RSV infections in under 3-year-old patients admitted to the Inpatient Paediatric Service of Vila Real (North of Portugal). For this purpose, (1) clinical files of children admitted with a diagnosis of acute bronchiolitis from September 2005 to December 2015 (>10 years) were scrutinised and (2) local daily temperature/precipitation series, as well as six weather types controlling meteorological conditions in Portugal, were used. Fifty-five percent of all 770 admitted children were effectively infected with a given virus, whilst 48 % (367) were RSV+, i.e. 87 % of virus-infected children were RSV+. The bulk of incidence is verified in the first year of age (82 %, 302), slightly higher in males. RSV outbreaks are typically from December to March, but important inter-annual variability is found in both magnitude and shape. Although no clear connections were found between monthly temperatures/precipitation and RSV outbreaks apart from seasonality, a linkage to wintertime cold spells is apparent on a daily basis. Anomalously low minimum temperatures from the day of admittance back to 10 days before are observed. This relationship is supported by anomalously high occurrences of the E and AA weather types over the same period, which usually trigger dry and cold weather. These findings highlight some predictability in the RSV occurrences, revealing potential for modelling and risk assessments.

  14. Step initiation in Parkinson's disease: influence of initial stance conditions.

    PubMed

    Rocchi, Laura; Chiari, Lorenzo; Mancini, Martina; Carlson-Kuhta, Patricia; Gross, Anne; Horak, Fay B

    2006-10-01

    In this study, we investigated how the size of preparatory postural adjustments prior to step initiation, and step length and velocity depend on initial stance width in patients with Parkinson's disease (PD) both in the ON and OFF levodopa states and in healthy elderly subjects. Twenty-one subjects with idiopathic PD and 24 age-matched healthy control subjects took two steps starting with feet on a two-plate force-platform, from either narrow or wide stance width. We measured how the magnitude of anticipatory postural adjustments (APA) and step characteristics scaled with stance width. Results showed that preparation for step initiation from wide stance was associated with a larger lateral and backward center of pressure (CoP) displacement than from narrow stance. Velocity and length of the first step were also sensitive to initial stance conditions, probably in relation with the differences in the corresponding APA. On the contrary, the duration of APA was not significantly affected by initial stance width, but it was longer in PD compared to healthy subjects, and speeded up by levodopa. Although subjects with PD did scale up the size of their APA with stance width, they had much more difficulty initiating a step from a wide stance than from a narrow stance, as shown by the greater differences from control subjects in the magnitude of the APA. Our results support the hypothesis that PD subjects maintain a narrow stance as a compensation for their inability to sufficiently increase the size of their lateral APA to allow fast step initiation in wide stance.

  15. The influence of convection parameterisations under alternate climate conditions

    NASA Astrophysics Data System (ADS)

    Rybka, Harald; Tost, Holger

    2013-04-01

    In the last decades several convection parameterisations have been developed to consider the impact of small-scale unresolved processes in Earth System Models associated with convective clouds. Global model simulations, which have been performed under current climate conditions with different convection schemes, significantly differ among each other in the simulated precipitation patterns due to the parameterisation assumptions and formulations, e.g. the simplified treatment of the cloud microphysics. Additionally, the simulated transport of short-lived trace gases strongly depends on the chosen convection parameterisation due to the differences in the vertical redistribution of mass. Furthermore, other meteorological parameters like the temperature or the specific humidity show substantial differences in convectively active regions. This study presents uncertainties of climate change scenarios caused by different convection parameterisations. For this analysis two experiments (reference simulation with a CO2 concentration of 348 ppm; 2xCO2-simulation with a CO2 concentration of 696 ppm) are calculated with the ECHAM/MESSy atmospheric chemistry (EMAC) model applying four different convection schemes (Tiedtke, ECMWF, Emanuel and Zhang-McFarlane - Hack) and two resolutions (T42 and T63), respectively. The results indicate that the equilibrium climate sensitivity is independent of the chosen convection parameterisation. However, the regional temperature increase, induced by a doubling of the carbon dioxide concentration, demonstrates differences of up to a few Kelvin at the surface as well as in the UTLS for the ITCZ region depending on the selected convection parameterisation. The interaction between cloud and convection parameterisations results in a large disagreement of precipitation patterns. Although every 2xCO2 -experiment simulates an increase in global mean precipitation rates, the change of regional precipitation patterns differ widely. Finally, analysing

  16. Chemical Evolution of Groundwater Near a Sinkhole Lake, Northern Florida: 1. Flow Patterns, Age of Groundwater, and Influence of Lake Water Leakage

    NASA Astrophysics Data System (ADS)

    Katz, Brian G.; Lee, Terrie M.; Plummer, L. Niel; Busenberg, Eurybiades

    1995-06-01

    Leakage from sinkhole lakes significantly influences recharge to the Upper Floridan aquifer in poorly confined sediments in northern Florida. Environmental isotopes (oxygen 18, deuterium, and tritium), chlorofluorocarbons (CFCs: CFC-11, CCl3F; CFC-12, CCl2F2; and CFC-113, C2Cl3F3), and solute tracers were used to investigate groundwater flow patterns near Lake Barco, a seepage lake in a mantled karst setting in northern Florida. Stable isotope data indicated that the groundwater downgradient from the lake contained 11-67% lake water leakage, with a limit of detection of lake water in groundwater of 4.3%. The mixing fractions of lake water leakage, which passed through organic-rich sediments in the lake bottom, were directly proportional to the observed methane concentrations and increased with depth in the groundwater flow system. In aerobic groundwater upgradient from Lake Barco, CFC-modeled recharge dates ranged from 1987 near the water table to the mid 1970s for water collected at a depth of 30 m below the water table. CFC-modeled recharge dates (based on CFC-12) for anaerobic groundwater downgradient from the lake ranged from the late 1950s to the mid 1970s and were consistent with tritium data. CFC-modeled recharge dates based on CFC-11 indicated preferential microbial degradation in anoxic waters. Vertical hydraulic conductivities, calculated using CFC-12 modeled recharge dates and Darcy's law, were 0.17, 0.033, and 0.019 m/d for the surficial aquifer, intermediate confining unit, and lake sediments, respectively. These conductivities agreed closely with those used in the calibration of a three-dimensional groundwater flow model for transient and steady state flow conditions.

  17. Aerosols and their influence on radiation partitioning and savanna productivity in northern Australia

    SciTech Connect

    Kanniah, K. D.; Beringer, J.; Tapper, N. J.; Long, Charles N.

    2010-05-01

    We investigated the effect of aerosols and clouds on the Net Ecosystem Productivity (NEP) of savannas in northern Australia using aerosol optical depth, clouds and radiation data from the Atmospheric Radiation Measurement (ARM) site in Darwin and carbon flux data measured from eddy covariance techniques from a site at Howard Springs, 35km southeast of Darwin. Generally we found that the concentration of aerosols in this region was relatively low than observed at other sites, therefore the proportion of diffuse radiation reaching the earths surface was only ~ 30%. As a result, we observed only a modest change in carbon uptake under aerosol laden skies and there was no significant difference for dry season Radiation Use Efficiency (RUE) between clear sky, aerosols or thin clouds. On the other hand thick clouds in the wet season produce much more diffuse radiation than aerosols or thin clouds and therefore the initial canopy quantum efficiency was seen to increase 45 and 2.5 times more than under thin clouds and aerosols respectively. The normalized carbon uptake under thick clouds is 57% and 50% higher than under aerosols and thin clouds respectively even though the total irradiance received under thick clouds was reduced 59% and 50% than under aerosols and thin clouds respectively. However, reduction in total irradiance decreases the mean absolute carbon uptake as much as 22% under heavy cloud cover compared to thin clouds or aerosols. Thus, any increase in aerosol concentration or cloud cover that can enhance the diffuse component may have large impacts on productivity in this region.

  18. Influence of climatic and hydrological factors on structure and composition of peat from northern wetland territories with low anthropogenic impact.

    PubMed

    Parfenova, L N; Selyanina, S B; Trufanova, M V; Bogolitsyn, K G; Orlov, A S; Volkova, N N; Ponomareva, T I; Sokolova, T V

    2016-05-01

    Northern wetlands ecosystems play an important role in the hydrological balance of neighboring areas, where they act as chemical barriers against anthropogenic and technogenic contaminations. Studied region is well known for quantity of peat deposits and the volume of peat resources. Peat can be considered as a highly informative marker for assessing change in environmental conditions. The study presents the results of the first investigation of peat samples, collected from representative ecosystems of northern wetland territories with low anthropogenic impact. Component and element composition of various peat types were studied in a relation to hydrologic, climate and sampling conditions. It was found out that organic and ash contents are more dependent on the type of the bog, than geographic location. Climatic factors are more important for the formation of bitumen. The degradation degree in peat increases proportionally to content of humates. High content of biogenic and lithogenic elements was observed in transition- and low-moor peat. The content of trace elements in peat samples do not depend on the type of the peat. The structural properties of peat were studied by the light microscopy, AFM and dynamic light scattering. It was determined that the conformation of studied peat samples is characterized by elements of asymmetry. The observed particles in the solutions exist in dynamic equilibrium with separated globular macromolecules. The size of these nanoparticles is comparable with the size of the particles of other biopolymers of similar nature. Swelling of peat in liquid water was studied. The relationship between structural specificities, origin of peat and its maximum degree of swelling was found. The degree of swelling can be used as structural-sensitive parameter in further research.

  19. Influence of climatic and hydrological factors on structure and composition of peat from northern wetland territories with low anthropogenic impact.

    PubMed

    Parfenova, L N; Selyanina, S B; Trufanova, M V; Bogolitsyn, K G; Orlov, A S; Volkova, N N; Ponomareva, T I; Sokolova, T V

    2016-05-01

    Northern wetlands ecosystems play an important role in the hydrological balance of neighboring areas, where they act as chemical barriers against anthropogenic and technogenic contaminations. Studied region is well known for quantity of peat deposits and the volume of peat resources. Peat can be considered as a highly informative marker for assessing change in environmental conditions. The study presents the results of the first investigation of peat samples, collected from representative ecosystems of northern wetland territories with low anthropogenic impact. Component and element composition of various peat types were studied in a relation to hydrologic, climate and sampling conditions. It was found out that organic and ash contents are more dependent on the type of the bog, than geographic location. Climatic factors are more important for the formation of bitumen. The degradation degree in peat increases proportionally to content of humates. High content of biogenic and lithogenic elements was observed in transition- and low-moor peat. The content of trace elements in peat samples do not depend on the type of the peat. The structural properties of peat were studied by the light microscopy, AFM and dynamic light scattering. It was determined that the conformation of studied peat samples is characterized by elements of asymmetry. The observed particles in the solutions exist in dynamic equilibrium with separated globular macromolecules. The size of these nanoparticles is comparable with the size of the particles of other biopolymers of similar nature. Swelling of peat in liquid water was studied. The relationship between structural specificities, origin of peat and its maximum degree of swelling was found. The degree of swelling can be used as structural-sensitive parameter in further research. PMID:26874767

  20. Influence of mowing on dynamics of native phytoseiid mites and Tetranychus urticae in apple orchards in northern Japan.

    PubMed

    Funayama, Ken

    2016-09-01

    To support practical integrated pest management in commercial apple orchards, I investigated the influence of mowing on the occurrence of Tetranychus urticae and native phytoseiid mites in apple orchards sprayed with selective insecticides in Akita Prefecture, northern Japan, from 2013 to 2015. The orchards were not mown in 2013, and unmown and mown plots were compared in 2014 and 2015. There were significantly fewer Typhlodromus vulgaris on apple leaves and Amblyseius tsugawai in the undergrowth in mown plots than in unmown plots in both years. Conversely, there were significantly more T. urticae on leaves and undergrowth in mown plots than in unmown plots. The reason for the decreased populations of these phytoseiid mites may be a lack of food (pollen) needed for reproduction on apple trees and in the undergrowth due to mowing. These results indicate that mowing strongly influences generalist phytoseiid mites in apple orchards. Moreover, mowing might increase the density of T. urticae in apple trees because increased nitrogen in the leaves increases fecundity; in addition, drought might promote the increase of mite numbers. Thus, retention of undergrowth suppresses T. urticae in apple orchards.

  1. Influence of mowing on dynamics of native phytoseiid mites and Tetranychus urticae in apple orchards in northern Japan.

    PubMed

    Funayama, Ken

    2016-09-01

    To support practical integrated pest management in commercial apple orchards, I investigated the influence of mowing on the occurrence of Tetranychus urticae and native phytoseiid mites in apple orchards sprayed with selective insecticides in Akita Prefecture, northern Japan, from 2013 to 2015. The orchards were not mown in 2013, and unmown and mown plots were compared in 2014 and 2015. There were significantly fewer Typhlodromus vulgaris on apple leaves and Amblyseius tsugawai in the undergrowth in mown plots than in unmown plots in both years. Conversely, there were significantly more T. urticae on leaves and undergrowth in mown plots than in unmown plots. The reason for the decreased populations of these phytoseiid mites may be a lack of food (pollen) needed for reproduction on apple trees and in the undergrowth due to mowing. These results indicate that mowing strongly influences generalist phytoseiid mites in apple orchards. Moreover, mowing might increase the density of T. urticae in apple trees because increased nitrogen in the leaves increases fecundity; in addition, drought might promote the increase of mite numbers. Thus, retention of undergrowth suppresses T. urticae in apple orchards. PMID:27380500

  2. Reconstructing conditions during dolomite formation on a Carnian coastal sabkha/alluvial plain using 87Sr/86Sr isotopes - Travenanzes Formation, northern Italy

    NASA Astrophysics Data System (ADS)

    Rieder, Maximilian; Wegner, Wencke; Horschinegg, Monika; Preto, Nereo; Breda, Anna; Klötzli, Urs; Peckmann, Jörn; Meister, Patrick

    2016-04-01

    indicated by oxygen isotopes. The marine 87Sr/86Sr values have been reconstructed for most of the Phanerozoic and are nearly constant in the Carnian (McArthur et al., 2012), while the age of the dolomite beds of the Travenanzes Formation is constrained by their stratigraphic position in the measured section (Dibona Section; Preto et al., 2015). The continental Sr isotope signal is governed by weathering rates, especially during silicate weathering of the source rock in the catchment area (McArthur et al., 2012). Through 87Sr/86Sr isotope investigation of primary dolomite in beds and nodules of the coastal sabkha or alluvial plain environment, the influence of marine or continental conditions can be determined. The finding of celestine SrSO4 and Sr-rich barite BaSO4 within the cemented dolomite by SEM indicates enrichment of Sr, possibly during strong evaporative conditions. Hence, the generation of phase-specific Sr-isotope data will allow for a more precise reconstruction of the conditions that led to dolomite formation in the Triassic shallow coastal sabkha/alluvial plain environment. McArthur et al. (2012) Strontium isotope stratigraphy. In: "The geologic time scale" (F.M Gradstein et al., eds.), Elsevier, p. 127-144. Preto et al. (2015) Primary dolomite in the Late Triassic Travenanzes Formation Dolomites, Northern Italy: Facies control and possible bacterial influence. Sedimentology 62, p. 697-716.

  3. How to comprehensively evaluate river corridor conditions? A comparison of different biotic and morphological indices in northern Italy

    NASA Astrophysics Data System (ADS)

    Golfieri, Bruno; Surian, Nicola; Hardersen, Sönke; Maiolini, Bruno

    2016-04-01

    The assessment of river conditions is crucial for planning appropriate management actions. The European Water Framework Directive 2000/60/EC (WFD) requires the assessment of biological, physical-chemical and hydromorphological elements to define the ecological status of rivers. The WFD suggests the use of different bioindicators (i.e. benthic macroinvertebrates, diatoms, aquatic macrophytes and fish), the so called "biological quality elements" (BQEs). However, recent studies showed that BQEs-based indices have two main limitations: (i) their standard application is limited to flowing channels and (ii) they are not sensitive to hydromorphological alteration. Hydromorphological conditions are usually evaluated applying methods for physical habitat assessment (i.e. the River Habitat Survey or derived methods) that consist in site-scale inventories of river forms and anthropic structures. The lack of consideration of wider spatial (i.e. reach or catchment scale) and temporal scales (e.g. channel evolution over the last 50-100 years) make such methods inadequate for a sound diagnosis of morphological alterations. The Morphological Quality Index (MQI) and the dragonfly-based Odonate River Index (ORI) were developed in the recent years to overcome the above-mentioned limitations and to assess the condition of the whole river corridor (i.e. the channel and its adjacent floodplain) at reach scale. In this study we correlated the assessments of MQI, ORI and two BQEs-based biotic indices (i.e. STAR_ICMi for benthic macroinvertebrates and ICMi for diatoms) in 15 lowland river reaches in northern Italy. The selected reaches are characterized by a wide range of morphological degradation. MQI and ORI were highly correlated, probably because both methods work at reach scale and consider the integrity of the whole river corridor, either in terms of morphology or considering ecological aspects. In contrast, no significant relationships were found between MQI and ORI and the BQEs

  4. Influence of Climate-induced Vegetation Shifts on Future Land Use and Associated Land Carbon Fluxes in Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Kicklighter, D. W.; Cai, Y.; Zhuang, Q.; Parfenova, E. I.; Sokolov, A. P.; Melillo, J. M.; Reilly, J. M.

    2012-04-01

    Land ecosystems in northern Eurasia will be under a variety of pressures in the 21st century that will affect both their structure and function. Climate change and land-use change are likely to be the major pressures. Climate change will lead to changes in disturbance regimes such as fire and changes in the distribution of plant and animal species. Land-use changes, driven by population growth, resource consumption and a broad set of economic considerations, will interact with climate-driven changes to reshape the earth's landscape. Here we present results of an integrated assessment analysis for the region that examines the consequences of concurrent pressures on land ecosystems associated with climate and land-use changes. Preliminary results indicate that climate-induced vegetation shifts allow more areas in northern Eurasia to be used for food crop production (an additional 23%) and pastures (an additional 38%), but limits the additional area to be used as managed forests (38% less) by the end of the 21st century than is projected when vegetation shifts are not considered and no climate policy is implemented. In contrast, under a climate policy, climate-induced vegetation shifts had little influence on food production, but allow more area to be used for cellulosic biofuel production (an additional 23%), and less additional area to be used for pasture (50% less) and managed forests (28% less) over this same time period. Fire associated with climate-induced vegetation shifts causes the region to become a carbon source over the 21st century whereas the region is projected to be a carbon sink if no vegetation shifts are assumed to occur. Thus, consideration of vegetation shifts should be included in future assessments of environmental change on terrestrial carbon budgets in this region.

  5. Non-polar organic compounds in marine aerosols over the northern South China Sea: Influence of continental outflow.

    PubMed

    Zhao, Yan; Zhang, Yingyi; Fu, Pingqing; Ho, Steven Sai Hang; Ho, Kin Fai; Liu, Fobang; Zou, Shichun; Wang, Shan; Lai, Senchao

    2016-06-01

    Filter samples of total suspended particle (TSP) collected during a cruise campaign over the northern South China Sea (SCS) from September to October 2013 were analyzed for non-polar organic compounds (NPOCs) as well as organic carbon (OC), elemental carbon (EC) and water-soluble ions. A total of 115 NPOCs species in groups of n-alkanes, polycyclic aromatic hydrocarbons (PAHs), iso-/antiso-alkanes, hopanes, steranes, methylalkanes, branched alkanes, cycloalkanes, alkenes and phthalates were detected. The characteristics of NPOCs in marine TSP samples were investigated to understand the sources from the Asian continent and other regions. The concentrations of total NPOCs ranged from 19.8 to 288.2 ng/m(3) with an average of 87.9 ng/m(3), which accounted for 0.8-1.7% (average 1.0%) of organic matter (OM). n-Alkanes was the predominant group, accounting for 43.1-79.5%, followed by PAHs (5.5-44.4%) and hopanes (1.6-11.4%). We found that primary combustion (biomass burning/fossil fuel combustion) was the dominant source for the majority of NPOCs (89.1%). Biomass burning in southern/southeastern China via long-range transport was proposed to be a major contributor of NPOCs in marine aerosols over the northern SCS, suggested by the significant correlations between nss-K(+) and NPOCs groups as well as the analysis of air mass back-trajectory and fire spots. For the samples with strong continental influence, the strong enhancement in concentrations of n-alkanes, PAHs, hopanes and steranes were attributed to fossil fuel (coal/petroleum) combustion. In addition, terrestrial plants waxes were another contributor to NPOCs. PMID:27023121

  6. Non-polar organic compounds in marine aerosols over the northern South China Sea: Influence of continental outflow.

    PubMed

    Zhao, Yan; Zhang, Yingyi; Fu, Pingqing; Ho, Steven Sai Hang; Ho, Kin Fai; Liu, Fobang; Zou, Shichun; Wang, Shan; Lai, Senchao

    2016-06-01

    Filter samples of total suspended particle (TSP) collected during a cruise campaign over the northern South China Sea (SCS) from September to October 2013 were analyzed for non-polar organic compounds (NPOCs) as well as organic carbon (OC), elemental carbon (EC) and water-soluble ions. A total of 115 NPOCs species in groups of n-alkanes, polycyclic aromatic hydrocarbons (PAHs), iso-/antiso-alkanes, hopanes, steranes, methylalkanes, branched alkanes, cycloalkanes, alkenes and phthalates were detected. The characteristics of NPOCs in marine TSP samples were investigated to understand the sources from the Asian continent and other regions. The concentrations of total NPOCs ranged from 19.8 to 288.2 ng/m(3) with an average of 87.9 ng/m(3), which accounted for 0.8-1.7% (average 1.0%) of organic matter (OM). n-Alkanes was the predominant group, accounting for 43.1-79.5%, followed by PAHs (5.5-44.4%) and hopanes (1.6-11.4%). We found that primary combustion (biomass burning/fossil fuel combustion) was the dominant source for the majority of NPOCs (89.1%). Biomass burning in southern/southeastern China via long-range transport was proposed to be a major contributor of NPOCs in marine aerosols over the northern SCS, suggested by the significant correlations between nss-K(+) and NPOCs groups as well as the analysis of air mass back-trajectory and fire spots. For the samples with strong continental influence, the strong enhancement in concentrations of n-alkanes, PAHs, hopanes and steranes were attributed to fossil fuel (coal/petroleum) combustion. In addition, terrestrial plants waxes were another contributor to NPOCs.

  7. Individualism-Collectivism as a Boundary Condition for Effectiveness of Minority Influence in Decision Making.

    PubMed

    Ng, K. Yee; Van Dyne, Linn

    2001-03-01

    Results of this experiment demonstrate that individualists and collectivists react differently to minority influence. Based on the distinction between objectivity and preference norms in the minority influence literature, we hypothesize that individualism and collectivism influence (A) responses to minority influence (focusing on the target of influence) and (B) effectiveness of minority influence (focusing on the influence agent). Our results replicate past research and demonstrate improved decision quality for individuals exposed to a minority perspective. Moreover, minority influence targets with high horizontal individualism and low horizontal collectivism made higher quality decisions. Influence targets with high vertical collectivism demonstrated higher quality decisions when the influence agent held a high status position in the group. Results also demonstrate that influence agents with high vertical individualism experienced less role stress than those with low vertical individualism. Finally, influence agents with low role stress were more effective in influencing the decision making of others. We discuss our findings in terms of boundary conditions to the minority influence process. Copyright 2000 Academic Press.

  8. Influence of vegetation canopies on precipitation partitioning and isotope fractionation in northern upland catchments

    NASA Astrophysics Data System (ADS)

    Braun, Hannah; Tetzlaff, Doerthe; Soulsby, Chris; Weiler, Markus

    2016-04-01

    Climate change is predicted to have far reaching implications for northern high latitude regions including changing precipitation regimes and increasing temperatures in the coming decades. In many areas this will promote increased forest cover as a result of vegetation succession or mitigation measures. For example, in the Scottish Highlands, forest cover is increasing as a result of adaptive management and increased biofuel production. In the wet, windy Scottish hydroclimate this has the potential to significantly increase interception losses, reduce net precipitation and affect the spatial and temporal distribution of soil moisture. Recent studies have also shown that such processes may also change the isotopic signature of net rainfall in throughfall and stemflow with implications for using isotopes as hydrological tracers. Such effects may be exacerbated by projected higher temperatures and reduced summer precipitation. The main focus of this study was to quantify the effects of forest and non-forest vegetation canopies on the spatio-temporal variability of throughfall and stemflow in the Bruntland Burn, a 3.2 km2 montane experimental catchment in the Scottish Highlands. We investigated differences in both the quantity and isotopic composition of throughfall and stemflow under Scots Pine (Pinus sylvestris) forest and heather (Calluna vulgaris) moorland growing on podzolic soils. Altogether, 75 throughfall and 10 stemflow collectors were placed in four plots with different topographic positions and vegetation characteristics (two different aged Scots pine plantations and two heather sites) and canopy coverage was determined using digital photography. Over a 5 month sampling period, weekly throughfall samples were taken. We also analysed more than 1100 samples for stable isotopes δ18O and δD. Interception losses were 38% under moorland and up to 47% for the plantation sides. Both throughfall and stemflow amounts were found to be highly variable and were mostly

  9. Pollution influences on atmospheric composition and chemistry at high northern latitudes: Boreal and California forest fire emissions

    NASA Astrophysics Data System (ADS)

    Singh, H. B.; Anderson, B. E.; Brune, W. H.; Cai, C.; Cohen, R. C.; Crawford, J. H.; Cubison, M. J.; Czech, E. P.; Emmons, L.; Fuelberg, H. E.; Huey, G.; Jacob, D. J.; Jimenez, J. L.; Kaduwela, A.; Kondo, Y.; Mao, J.; Olson, J. R.; Sachse, G. W.; Vay, S. A.; Weinheimer, A.; Wennberg, P. O.; Wisthaler, A.; The Arctas Science Team

    2010-11-01

    We analyze detailed atmospheric gas/aerosol composition data acquired during the 2008 NASA ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) airborne campaign performed at high northern latitudes in spring (ARCTAS-A) and summer (ARCTAS-B) and in California in summer (ARCTAS-CARB). Biomass burning influences were widespread throughout the ARCTAS campaign. MODIS data from 2000 to 2009 indicated that 2008 had the second largest fire counts over Siberia and a more normal Canadian boreal forest fire season. Near surface arctic air in spring contained strong anthropogenic signatures indicated by high sulfate. In both spring and summer most of the pollution plumes transported to the Arctic region were from Europe and Asia and were present in the mid to upper troposphere and contained a mix of forest fire and urban influences. The gas/aerosol composition of the high latitude troposphere was strongly perturbed at all altitudes in both spring and summer. The reactive nitrogen budget was balanced with PAN as the dominant component. Mean ozone concentrations in the high latitude troposphere were only minimally perturbed (<5 ppb), although many individual pollution plumes sampled in the mid to upper troposphere, and mixed with urban influences, contained elevated ozone (ΔO 3/ΔCO = 0.11 ± 0.09 v/v). Emission and optical characteristics of boreal and California wild fires were quantified and found to be broadly comparable. Greenhouse gas emission estimates derived from ARCTAS-CARB data for the South Coast Air Basin of California show good agreement with state inventories for CO 2 and N 2O but indicate substantially larger emissions of CH 4. Simulations by multiple models of transport and chemistry were found to be broadly consistent with observations with a tendency towards under prediction at high latitudes.

  10. Environmental Attributes Influencing the Distribution of Burkholderia pseudomallei in Northern Australia

    PubMed Central

    Baker, Anthony L.; Ezzahir, Jessica; Gardiner, Christopher; Shipton, Warren; Warner, Jeffrey M.

    2015-01-01

    Factors responsible for the spatial and temporal clustering of Burkholderia pseudomallei in the environment remain to be elucidated. Whilst laboratory based experiments have been performed to analyse survival of the organism in various soil types, such approaches are strongly influenced by alterations to the soil micro ecology during soil sanitisation and translocation. During the monsoonal season in Townsville, Australia, B. pseudomallei is discharged from Castle Hill (an area with a very high soil prevalence of the organism) by groundwater seeps and is washed through a nearby area where intensive sampling in the dry season has been unable to detect the organism. We undertook environmental sampling and soil and plant characterisation in both areas to ascertain physiochemical and macro-floral differences between the two sites that may affect the prevalence of B. pseudomallei. In contrast to previous studies, the presence of B. pseudomallei was correlated with a low gravimetric water content and low nutrient availability (nitrogen and sulphur) and higher exchangeable potassium in soils favouring recovery. Relatively low levels of copper, iron and zinc favoured survival. The prevalence of the organism was found to be highest under the grasses Aristida sp. and Heteropogon contortus and to a lesser extent under Melinis repens. The findings of this study indicate that a greater variety of factors influence the endemicity of melioidosis than has previously been reported, and suggest that biogeographical boundaries to the organisms’ distribution involve complex interactions. PMID:26398904

  11. Factors that influence the hydrologic recovery of wetlands in the Northern Tampa Bay area, Florida

    USGS Publications Warehouse

    Metz, P.A.

    2011-01-01

    Although of less importance than the other three factors, a low-lying topographical position benefited the hydrologic condition of several of the study wetlands (S-68 Cypress and W-12 Cypress) both before and after the reductions in groundwater withdrawals. Compared to wetlands in a higher topographical position, those in a lower position had longer hydroperiods because of their greater ability to receive more runoff from higher elevation wetlands and to establish surface-water connections to other isolated wetlands and surface-water bodies through low-lying surface-water channels during wet conditions. In addition, wetlands in low-lying areas benefited from groundwater inflow when groundwater levels were higher than wetland water levels.

  12. Geophysical features influence the climate change sensitivity of northern Wisconsin pine and oak forests.

    PubMed

    Tweiten, Michael A; Calcote, Randy R; Lynch, Elizabeth A; Hotchkiss, Sara C; Schuurman, Gregor W

    2015-10-01

    Landscape-scale vulnerability assessment from multiple sources, including paleoecological site histories, can inform climate change adaptation. We used an array of lake sediment pollen and charcoal records to determine how soils and landscape factors influenced the variability of forest composition change over the past 2000 years. The forests in this study are located in northwestern Wisconsin on a sandy glacial outwash plain. Soils and local climate vary across the study area. We used the Natural Resource Conservation Service's Soil Survey Geographic soil database and published fire histories to characterize differences in soils and fire history around each lake site. Individual site histories differed in two metrics of past vegetation dynamics: the extent to which white pine (Pinus strobus) increased during the Little Ice Age (LIA) climate period and the volatility in the rate of change between samples at 50-120 yr intervals. Greater increases of white pine during the LIA occurred on sites with less sandy soils (R² = 0.45, P < 0.0163) and on sites with relatively warmer and drier local climate (R² = 0.55, P < 0.0056). Volatility in the rate of change between samples was positively associated with LIA fire frequency (R² = 0.41, P < 0.0256). Over multi-decadal to centennial timescales, forest compositional change and rate-of-change volatility were associated with higher fire frequency. Over longer (multi-centennial) time frames, forest composition change, especially increased white pine, shifted most in sites with more soil moisture. Our results show that responsiveness of forest composition to climate change was influenced by soils, local climate, and fire. The anticipated climatic changes in the next century will not produce the same community dynamics on the same soil types as in the past, but understanding past dynamics and relationships can help us assess how novel factors and combinations of factors in the future may influence various site types. Our

  13. Geophysical features influence the climate change sensitivity of northern Wisconsin pine and oak forests.

    PubMed

    Tweiten, Michael A; Calcote, Randy R; Lynch, Elizabeth A; Hotchkiss, Sara C; Schuurman, Gregor W

    2015-10-01

    Landscape-scale vulnerability assessment from multiple sources, including paleoecological site histories, can inform climate change adaptation. We used an array of lake sediment pollen and charcoal records to determine how soils and landscape factors influenced the variability of forest composition change over the past 2000 years. The forests in this study are located in northwestern Wisconsin on a sandy glacial outwash plain. Soils and local climate vary across the study area. We used the Natural Resource Conservation Service's Soil Survey Geographic soil database and published fire histories to characterize differences in soils and fire history around each lake site. Individual site histories differed in two metrics of past vegetation dynamics: the extent to which white pine (Pinus strobus) increased during the Little Ice Age (LIA) climate period and the volatility in the rate of change between samples at 50-120 yr intervals. Greater increases of white pine during the LIA occurred on sites with less sandy soils (R² = 0.45, P < 0.0163) and on sites with relatively warmer and drier local climate (R² = 0.55, P < 0.0056). Volatility in the rate of change between samples was positively associated with LIA fire frequency (R² = 0.41, P < 0.0256). Over multi-decadal to centennial timescales, forest compositional change and rate-of-change volatility were associated with higher fire frequency. Over longer (multi-centennial) time frames, forest composition change, especially increased white pine, shifted most in sites with more soil moisture. Our results show that responsiveness of forest composition to climate change was influenced by soils, local climate, and fire. The anticipated climatic changes in the next century will not produce the same community dynamics on the same soil types as in the past, but understanding past dynamics and relationships can help us assess how novel factors and combinations of factors in the future may influence various site types. Our

  14. Influence of the external DEM on PS-InSAR processing and results on Northern Appennine slopes

    NASA Astrophysics Data System (ADS)

    Bayer, B.; Schmidt, D. A.; Simoni, A.

    2014-12-01

    We present an InSAR analysis of slow moving landslide in the Northern Appennines, Italy, and assess the dependencies on the choice of DEM. In recent years, advanced processing techniques for synthetic aperture radar interferometry (InSAR) have been applied to measure slope movements. The persistent scatterers (PS-InSAR) approach is probably the most widely used and some codes are now available in the public domain. The Stanford method of Persistent Scatterers (StamPS) has been successfully used to analyze landslide areas. One problematic step in the processing chain is the choice of an external DEM that is used to model and remove the topographic phase in a series of interferograms in order to obtain the phase contribution caused by surface deformation. The choice is not trivial, because the PS InSAR results differ significantly in terms of PS identification, positioning, and the resulting deformation signal. We use four different DEMs to process a set of 18 ASAR (Envisat) scenes over a mountain area (~350 km2) of the Northern Appennines of Italy, using StamPS. Slow-moving landslides control the evolution of the landscape and cover approximately 30% of the territory. Our focus in this presentation is to evaluate the influence of DEM resolution and accuracy by comparing PS-InSAR results. On an areal basis, we perform a statistical analysis of displacement time-series to make the comparison. We also consider two case studies to illustrate the differences in terms of PS identification, number and estimated displacements. It is clearly shown that DEM accuracy positively influences the number of PS, while line-of-sight rates differ from case to case and can result in deformation signals that are difficult to interpret. We also take advantage of statistical tools to analyze the obtained time-series datasets for the whole study area. Results indicate differences in the style and amount of displacement that can be related to the accuracy of the employed DEM.

  15. Age at Menarche and Factors that Influence It: A Study among Female University Students in Tamale, Northern Ghana

    PubMed Central

    Ameade, Evans Paul Kwame; Garti, Helene Akpene

    2016-01-01

    Introduction Age at menarche reflects the health status of a population. This marks the beginning of sexual maturation and is affected by nutritional status and prevailing environmental conditions. This study measured the menarcheal age of female undergraduate students in northern Ghana and explored factors that could impact on the onset of menarche. Method GraphPad 5.01 was used to analyze data collected from 293 randomly selected female university students in a cross-sectional study using a semi-structured questionnaire. Association between different variables was tested using appropriate statistical tests. Results The mean recall age at menarche of participants in this study was 13.66 ±1.87 years for a female population of mean age, 23.04±5.07 years. Compared to female students who lived in rural settings, urban and suburban areas dwellers significantly recorded earlier menarche (p = 0.0006). Again, females from high income earning families experienced menarche earlier than those who were born to or lived with lower income earners (p = 0.003). Lower menarcheal age increased risk of experiencing menstrual pain prior to menses rather than during menstrual flow for dysmenorrhic females. (13.52±2.052 vrs 13.63±1.582 year; χ2 = 7.181, df = 2, p = 0.028). Conclusion Mean menarcheal age of female university students in northern Ghana was 13.66 years. Females from urban areas and high income families had earlier menarche. Compared to the very first Ghanaian study reported in 1989, the menarcheal age decline was 0.11 year per decade. PMID:27171234

  16. Post-wildfire natural restoration of riparian vegetation under stable hydro-geomorphic conditions: Nahal Grar, Northern Negev Desert, Israel

    NASA Astrophysics Data System (ADS)

    Egozi, Roey

    2015-04-01

    Wildfires are common to the Mediterranean region due to its defined dry season and long historical anthropogenic activities. Most of post-wildfire studies focus on mountains areas and thus refer to the hill-slope and its physical characteristics, e.g. morphology, length, angles, and aspect; its soil characteristics, e.g. type, infiltration rate, repellency; and its vegetative covers, e.g. planted trees vs. natural forest or native vs. exotic vegetation. In contrary there is very limited literature focusing on ecological and hydro-geomorphic aspects of post-wildfire of riparian vegetation / zone probably because of its negligible burned area relative to the spread of the fire, sometimes, over the whole watershed area. The limited literature on the topic is surprising given the fact that riparian vegetation zone has been acknowledged as a unique and important habitat supporting rich biodiversity. Herein we report on a wildfire event occurred on October 14th 2009 in a river section of Nahal Grar, Northern Negev Desert, Israel. The wildfire although was limited in its area (only 3 hectare) extended over the channel alone from bank to bank and thus provide a unique case study of completely burn down of riparian vegetation, mainly dense stands of Common Red (Australis Phragmites. Therefore a detailed study of this event provides an opportunity to tackle one of the basics questions which is determining the rate of natural restoration process that act at the immediate time after the wildfire event occurred. This type of information is most valuable to professional and stakeholders for better management of post-fire riparian zones. The results of the study suggest that under stable conditions, i.e. no major flood events occurred; disturbance time was short and ranged over 200 days due to, almost, immediate recovery of the riparian vegetation. However the re-growth of the riparian vegetation was not even but rather deferential and more complex then reported in the literature

  17. Forecasting the major influences of predation and environment on cod recovery in the northern Gulf of St. Lawrence.

    PubMed

    Bousquet, Nicolas; Chassot, Emmanuel; Duplisea, Daniel E; Hammill, Mike O

    2014-01-01

    The northern Gulf of St. Lawrence (NGSL) stock of Atlantic cod (Gadus morhua), historically the second largest cod population in the Western Atlantic, has known a severe collapse during the early 1990 s and is currently considered as endangered by the Committee on the Status of Endangered Wildlife in Canada. As for many fish populations over the world which are currently being heavily exploited or overfished, urgent management actions in the form of recovery plans are needed for restoring this stock to sustainable levels. Stochastic projections based on a statistical population model incorporating predation were conducted over a period of 30 years (2010-2040) to assess the expected outcomes of alternative fishing strategies on the stock recovery under different scenarios of harp seal (Pagophilus groenlandicus) abundance and environmental conditions. This sensitivity study shows that water temperature is key in the rebuilding of the NGSL cod stock. Model projections suggest that maintaining the current management practice under cooler water temperatures is likely to maintain the species in an endangered status. Under current or warmer conditions in the Gulf of St. Lawrence, partial recovery might only be achieved by significant reductions in both fishing and predation pressure. In the medium-term, a management strategy that reduces catch could be favoured over a complete moratorium so as to minimize socio-economic impacts on the industry.

  18. Forecasting the Major Influences of Predation and Environment on Cod Recovery in the Northern Gulf of St. Lawrence

    PubMed Central

    Bousquet, Nicolas; Chassot, Emmanuel; Duplisea, Daniel E.; Hammill, Mike O.

    2014-01-01

    The northern Gulf of St. Lawrence (NGSL) stock of Atlantic cod (Gadus morhua), historically the second largest cod population in the Western Atlantic, has known a severe collapse during the early 1990 s and is currently considered as endangered by the Committee on the Status of Endangered Wildlife in Canada. As for many fish populations over the world which are currently being heavily exploited or overfished, urgent management actions in the form of recovery plans are needed for restoring this stock to sustainable levels. Stochastic projections based on a statistical population model incorporating predation were conducted over a period of 30 years (2010–2040) to assess the expected outcomes of alternative fishing strategies on the stock recovery under different scenarios of harp seal (Pagophilus groenlandicus) abundance and environmental conditions. This sensitivity study shows that water temperature is key in the rebuilding of the NGSL cod stock. Model projections suggest that maintaining the current management practice under cooler water temperatures is likely to maintain the species in an endangered status. Under current or warmer conditions in the Gulf of St. Lawrence, partial recovery might only be achieved by significant reductions in both fishing and predation pressure. In the medium-term, a management strategy that reduces catch could be favoured over a complete moratorium so as to minimize socio-economic impacts on the industry. PMID:24523852

  19. [Influence of ozone on snap bean under ambient air in two sites of northern China].

    PubMed

    Yuan, Xiang-Yang; Zhang, Wei-Wei; Sun, Jing-Song; Hu, En-Zhu; Zhang, Yu-Long; Zhang, Hong-Xing; Tian, Yuan; Feng, Zhao-Zhong

    2014-08-01

    Tropospheric ozone (O3) has been assumed the most phytotoxic air pollutant and the snap bean (Phaseolus vulgaris L.) is known to be an ozone-sensitive species. Two genotypes (R123, ozone-tolerance, S156, ozone-sensitivity) of snap bean were explored in three places. The objective of this study was to evaluate whether the snap bean was influenced under the current ambient ozone concentration. The findings indicated that the leaves of bean grown at Research Center for Eco-Environmental Sciences (RCEES), Chinese Academy of Sciences and ChangPing showed visible ozone symptoms under the ambient ozone concentration, and the averaged ozone injury proportion in S156 was 23.5% higher than R123 during the entire growth season. The ozone damage to the snap bean depends on the plant growing stages. The injury symptoms appeared just after flowering, increased from the stages of flowering to pod formation, and reached the maximum at the stages of pod maturation. The ratio of S156/R123 in pod yield was 0.48, and 0.24 and 0.73 in the RCEES, ChangPing and Harbin, respectively. The ratio close to 1 was assumed that the plant growth is not affected by ozone, and the lower ratio is, the more damage caused by ozone. Obviously, the current ambient ozone concentration of Beijing area has significantly caused the yield loss of snap bean.

  20. Influence of salinity, bottom topography, and tides on locations of estuarine turbidity maxima in northern San Francisco Bay

    USGS Publications Warehouse

    Schoellhamer, David H.

    2000-01-01

    Time series of salinity and suspended-solids concentration measured at four locations and vertical profiles of salinity and suspended-solids concentration measured during 48 water-quality cruises from January 1993 to September 1997 are analyzed to describe the influence of salinity, bottom topography, and tides on locations of estuarine turbidity maxima in northern San Francisco Bay, California. Estuarine turbidity maxima form when salinity is present but they are not associated with a singular salinity. Bottom topography enhances salinity stratification, gravitational circulation and estuarine turbidity maxima formation seaward of sills. The spring/neap tidal cycle affects locations of estuarine turbidity maxima. Salinity stratification in Carquinez Strait, which is seaward of a sill, is greatest during neap tides, which is the only time when tidally averaged suspended-solids concentration in Carquinez Strait was less than that observed landward at Mallard Island. Spring tides cause the greatest vertical mixing and suspended-solids concentration in Carquinez Strait. Therefore, surface estuarine turbidity maxima always were located in or near the Strait (seaward of Middle Ground) during spring tide cruises, regardless of salinity. During neap tides, surface estuarine turbidity maxima always were observed in the landward half of the study area (landward of Middle Ground) and between 0–2 practical salinity units.

  1. Spatial distribution of calcium in food, water and soil and its possible influence on rickets disease in Northern Nigeria.

    PubMed

    Hartmann, Lena; Sponholz, Barbara

    2012-08-01

    Since the 1990s, children of the Gbagyi tribe in Northern Nigeria have been suffering severe rickets with an incidence of up to 40% in the children's generation. The disease seems to be prevalent in an area of approximately 100 km(2) south-east of Kaduna. According to broad medical studies in that area, there is no evidence for a genetic disposition but for a nutritional cause of the disease. A lack of calcium was found in blood and was calculated to originate from diet. We therefore checked parent material, soil, maize cobs (Zea mays) and drinking water for their specific Ca contents from a region with rickets problem (study area A) and compared the results to Ca amounts in similar samples from a region where rickets is unknown among the Gbagyi population (study area B). It thereby became apparent that there are no differences in mineralogical composition of the parent material between the study areas, but that Ca contents in soil, maize cobs and drinking water are 47.6%, 26.6%, respectively, 79.1% lower in study area A compared to study area B. This result suggests that there may indeed be a nutritionally and/or environmentally influence on rickets disease. Nevertheless, further research on this topic is required.

  2. Influence of sediment characteristics on the composition of soft-sediment intertidal communities in the northern Gulf of Mexico

    PubMed Central

    Henkel, Jessica R.; Sigel, Bryan J.; Taylor, Caz M.

    2015-01-01

    Benthic infaunal communities are important components of coastal ecosystems. Understanding the relationships between the structure of these communities and characteristics of the habitat in which they live is becoming progressively more important as coastal systems face increasing stress from anthropogenic impacts and changes in climate. To examine how sediment characteristics and infaunal community composition were related along the northern Gulf of Mexico coast, we sampled intertidal infaunal communities at seven sites covering common habitat types at a regional scale. Across 69 samples, the communities clustered into four distinct groups on the basis of faunal composition. Nearly 70% of the variation in the composition of the communities was explained by salinity, median grain size, and total organic content. Our results suggest that at a regional level coarse habitat characteristics are able to explain a large amount of the variation among sites in infaunal community structure. By examining the relationships between infaunal communities and their sedimentary habitats, we take a necessary first step that will allow the exploration of how changes in habitat and community composition influence higher trophic levels and ecosystem scale processes. PMID:26157603

  3. Grandmothers as gatekeepers? The role of grandmothers in influencing health-seeking for mothers and newborns in rural northern Ghana.

    PubMed

    Gupta, Mira L; Aborigo, Raymond Akawire; Adongo, Philip Baba; Rominski, Sarah; Hodgson, Abraham; Engmann, Cyril M; Moyer, Cheryl A

    2015-10-01

    Previous research suggests that care-seeking in rural northern Ghana is often governed by a woman's husband or compound head. This study was designed to explore the role grandmothers (typically a woman's mother-in-law) play in influencing maternal and newborn healthcare decisions. In-depth interviews were conducted with 35 mothers of newborns, 8 traditional birth attendants and local healers, 16 community leaders and 13 healthcare practitioners. An additional 18 focus groups were conducted with stakeholders such as household heads, compound leaders and grandmothers. In this region, grandmothers play many roles. They may act as primary support providers to pregnant mothers, care for newborns following delivery, preserve cultural traditions and serve as repositories of knowledge on local medicine. Grandmothers may also serve as gatekeepers for health-seeking behaviour, especially with regard to their daughters and daughters-in-law. This research also sheds light on the potential gap between health education campaigns that target mothers as autonomous decision-makers, and the reality of a more collectivist community structure in which mothers rarely make such decisions without the support of other community members.

  4. Influence of seasonal forcing on habitat use by bottlenose dolphins Tursiops truncatus in the Northern Adriatic Sea

    NASA Astrophysics Data System (ADS)

    Bearzi, Giovanni; Azzellino, Arianna; Politi, Elena; Costa, Marina; Bastianini, Mauro

    2008-12-01

    Bottlenose dolphins are the only cetaceans regularly observed in the northern Adriatic Sea, but they survive at low densities and are exposed to significant threats. This study investigates some of the factors that influence habitat use by the animals in a largely homogeneous environment by combining dolphin data with hydrological and physiographical variables sampled from oceanographic ships. Surveys were conducted year-round between 2003 and 2006, totalling 3,397 km of effort. Habitat modelling based on a binary stepwise logistic regression analysis predicted between 81% and 93% of the cells where animals were present. Seven environmental covariates were important predictors: oxygen saturation, water temperature, density anomaly, gradient of density anomaly, turbidity, distance from the nearest coast and bottom depth. The model selected consistent predictors in spring and summer. However, the relationship (inverse or direct) between each predictor and dolphin presence varied among seasons, and different predictors were selected in fall. This suggests that dolphin distribution changed depending on seasonal forcing. As the study area is relatively uniform in terms of bottom topography, habitat use by the animals seems to depend on complex interactions among hydrological variables, caused primarily by seasonal change and likely to determine shifts in prey distribution.

  5. Distinguishing between climatic and tectonic influences on topography: Best practices and application to the Northern Bolivian Andes

    NASA Astrophysics Data System (ADS)

    Gasparini, N. M.; Whipple, K. X.

    2015-12-01

    The hypothesis that high rainfall rates have the power to drive erosion and shape landscapes is tantalizing. However, definitive support for this hypothesis has been somewhat elusive, in part because high rainfall rates often occur in areas of high rock uplift rates. Here we present a number of best practices, developed from theory and landscape evolution modeling, that can be used to decipher whether climate, tectonics, or both importantly affect landscape morphology and evolution. For illustration we assume that there is a single, dominant gradient in both rainfall and rock uplift rates across the landscape. We quantify the morphology of rivers using the normalized channel steepness index, ksn, or channel slope normalized by drainage area. If rainfall influences landscape evolution solely through the production of runoff and fluvial discharge, then ksn is inversely proportional to the upstream averaged rainfall rate. In contrast, ksn is directly proportional to the local rock uplift rate. Exploring patterns in channels that primarily flow perpendicular to the gradient in forcing and channels that flow parallel to the gradient in forcing, illustrates the influence of different drivers. In channels that flow in the direction of the gradient, the rock uplift forcing should have a greater impact on channel form. However, when comparing among channels that flow perpendicular to the gradient, ksn should vary with the local rainfall rate. We apply these ideas in the Eastern Cordillera of the Northern Bolivian Andes, where modern rainfall rates and hypothesized rock uplift rates vary in the same dominant direction. We explore the morphology of channels that are both parallel and perpendicular to the gradient in forcings and find that the pattern of rock uplift dominates the morphology of the landscape, but that climate likely has a secondary effect. Using published erosion rate data from detrital 10Be, we find no correlation between rainfall and erosion rates.

  6. Habitat characteristics influence macrofaunal communities in coralline turf more than mesoscale coastal upwelling on the coast of Northern Chile

    NASA Astrophysics Data System (ADS)

    Kelaher, Brendan P.; Carlos Castilla, Juan

    2005-04-01

    Rocky shore communities are often influenced by near-shore coastal upwelling. For macrofauna in algal turf, these effects may be caused directly by well-studied bottom-up mechanisms or indirectly via changes in habitat structure provided by algal turf associated high nutrient loads. Here, we investigated possible interactions between upwelling and habitat structure by sampling diverse faunal assemblages in coralline algal turf on seven rocky intertidal shores in northern Chile, ranging from El Cobre [23°17'1″S, 70°31'40″W] to La Lobería [23°03'40″S, 70°33'14″W]. Some of these shores were located adjacent to strong upwelling centers, while others were in areas rarely affected. On each shore, we sampled four (2 × 2 m) sites separated by 15-50 m. In each site, we collected three replicate cores (80 mm in diameter) from which we measured macrofauna greater than 850 μm, biomass of sediment and epiphytes, frond density and average frond length. We used mean water temperature and its variation at 1-1.5 m water depth (below Extreme Low Water Spring, ELWS) to represent local upwelling intensity because long-term data have shown that these variables make excellent indicators for this region. In total, we found 94 macrofaunal taxa in coralline turf, which is almost three times higher than has previously been reported in Chile. Although macrofaunal assemblages varied significantly among shores, there were no patterns to suggest mesoscale variation in upwelling intensity affected either faunal assemblages or local habitat characteristics. In contrast, multivariate and univariate correlations highlighted sediment and frond density as strong determinants of community structure. We therefore conclude that traditionally studied habitat characteristics, such as structural complexity and habitat heterogeneity, have greater influence on faunal assemblages in mat-like habitats on rocky shores than environmental variables associated with mesoscale coastal upwelling.

  7. Asymmetry and nonlinearity of the influence of ENSO on the northern winter stratosphere: 2. Model study with WACCM

    NASA Astrophysics Data System (ADS)

    Rao, Jian; Ren, Rongcai

    2016-08-01

    Long-term simulations from the Community Earth System Model with the Whole Atmosphere Community Climate Model (CESM-WACCM) as its atmospheric component are used to investigate the asymmetry and the nonlinearity of the influences of El Niño-Southern Oscillation (ENSO) on the northern winter stratosphere. As in Part 1 of this study, four different types of ENSO are considered. The composite CESM-WACCM results first confirm the conclusions drawn from the observations, that the stratospheric polar jet responses to "moderate El Niño" and "strong La Niña" are stronger than those to "strong El Niño" and "moderate La Niña". In association with the ENSO sea surface temperature (SST) patterns that are reproduced well in the model, the tropical rainfall response centers exhibit an asymmetric east-west shift between El Niño and La Niña, which directly leads to the nonlinear and asymmetric Pacific-North America responses in the extratropics. Accordingly, the strengthening (weakening) planetary wave response in the stratosphere during warm (cold) ENSO also exhibits nonlinear and asymmetric features. When the ENSO SST forcing is prescribed to be linear and symmetric in WACCM, the nonlinearity and asymmetry of the stratospheric responses to moderate ENSO reveal the dominant role of the inherent properties of the atmosphere. However, the absence of asymmetry and nonlinearity in the stratospheric responses to strong ENSO in our sensitivity experiments indicates that the asymmetry in SST forcing between strong El Niño and La Niña still plays an important role in the asymmetric and nonlinear influences of ENSO on the extratropics.

  8. Influence of body condition on reproductive output in the guinea pig.

    PubMed

    Michel, Catherine Louise; Bonnet, Xavier

    2012-01-01

    Reproduction is expensive. Substantial body reserves (i.e. high body condition) are usually required for females to undertake offspring production. In many vertebrates, maternal body condition positively influences reproductive output, and emaciated individuals skip reproduction. However, the impact of extremely high body condition, more specifically obesity, on animal reproductive performance remains poorly understood and research has generated contradictory results. For instance, obesity negatively affects fertility in women, but does not influence reproductive capacity or reproductive output in laboratory rodents. We examined the influence of high body condition on reproductive status and reproductive output in the guinea pig. In captivity, when fed ad libitum, guinea pigs store large amounts of fat tissues and exhibit a tendency for obesity. Our results show that obesity negatively affected reproduction in this species: both the proportion of fertile females and litter size were lower in the fattest females. Therefore, guinea pigs may represent suitable organisms to better understand the negative effect of obesity on reproduction.

  9. Factors influencing nesting success of king eiders on northern Alaska's Coastal Plain

    USGS Publications Warehouse

    Bentzen, R.L.; Powell, A.N.; Suydam, R.S.

    2008-01-01

    visits in future studies and to consider them as a possible negative bias in estimated nest survival. Future models of the impacts of development within the breeding grounds of king eider should consider the influence of humans in the vicinity of nests.

  10. Germanium-silicon fractionation in a river-influenced continental margin: The Northern Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Baronas, J. Jotautas; Hammond, Douglas E.; Berelson, William M.; McManus, James; Severmann, Silke

    2016-04-01

    In this study we have sampled the water column and sediments of the Gulf of Mexico to investigate the effects of high riverine terrigenous load and sediment redox conditions on the cycling of Ge and Si. Water column Ge/Si ratios across the Gulf of Mexico continental shelf range from 1.9 to 25 μmol/mol, which is elevated compared to the global ocean value of 0.7 μmol/mol. The Ge enrichment in the Gulf of Mexico seawater is primarily due to anthropogenic contamination of the Mississippi river, which is the main Ge and Si source to the area, and to a smaller extent due to discrimination against Ge during biogenic silica (bSi) production (Ge/Si = 1.2-1.8 μmol/mol), especially by radiolarians and siliceous sponges (Ge/Si = 0.6-1.1 μmol/mol). Most sediment pore waters (Ge/Si = 0.3-4.5 μmol/mol) and sediment incubation experiments (benthic flux Ge/Si = 0.9-1.2 μmol/mol) indicate precipitation of authigenic phases that sequester Ge from pore waters (non-opal sink). This process appears to be independent of oxidation-reduction reactions and suggests that authigenic aluminosilicate formation (reverse weathering) may be the dominant Ge sink in marine sediments. Compilation of previously published data shows that in continental margins, non-opal Ge burial flux is controlled by bSi supply, while in open ocean sediments it is 10-100 times lower and most likely limited by the supply of lithogenic material. We provide a measurement-based estimate of the global non-opal Ge burial flux as 4-32 Mmol yr-1, encompassing the 2-16 Mmol yr-1 needed to keep the global marine Ge cycle at steady state.

  11. Short-term Influences on Suspended Particulate Matter Distribution in the Northern Gulf of Mexico: Satellite and Model Observations

    PubMed Central

    D'Sa, Eurico J.; Ko, Dong S.

    2008-01-01

    Energetic meteorological events such as frontal passages and hurricanes often impact coastal regions in the northern Gulf of Mexico that influence geochemical processes in the region. Satellite remote sensing data such as winds from QuikSCAT, suspended particulate matter (SPM) concentrations derived from SeaWiFS and the outputs (sea level and surface ocean currents) of a nested navy coastal ocean model (NCOM) were combined to assess the effects of frontal passages between 23-28 March 2005 on the physical properties and the SPM characteristics in the northern Gulf of Mexico. Typical changes in wind speed and direction associated with frontal passages were observed in the latest 12.5 km wind product from QuikSCAT with easterly winds before the frontal passage undergoing systematic shifts in direction and speed and turning northerly, northwesterly during a weak and a strong front on 23 and 27 March, respectively. A quantitative comparison of model sea level results with tide gauge observations suggest better correlations near the delta than in the western part of the Gulf with elevated sea levels along the coast before the frontal passage and a large drop in sea level following the frontal passage on 27 March. Model results of surface currents suggested strong response to wind forcing with westward and onshore currents before the frontal passage reversing into eastward, southeastward direction over a six day period from 23 to 28 March 2005. Surface SPM distribution derived from SeaWiFS ocean color data for two clear days on 23 and 28 March 2005 indicated SPM plumes to be oriented with the current field with increasing concentrations in nearshore waters due to resuspension and discharge from the rivers and bays and its seaward transport following the frontal passage. The backscattering spectral slope γ, a parameter sensitive to particle size distribution also indicated lower γ values (larger particles) in nearshore waters that decreased offshore (smaller particles

  12. Features of Duration and Borders of the Bedding of Snow Cover in the Conditions of Climatic Changes in the Territory of Northern Kazakhstan According to Land and Space Monitoring

    NASA Astrophysics Data System (ADS)

    Salnikov, Vitaliy; Turulina, Galina; Polyakova, Svetlana; Muratova, Nadiya; Kauazov, Azamat; Abugalieva, Aigul; Tazhibayeva, Tamara

    2014-05-01

    Precipitation and air temperature datasets from 34 meteorological stations were analyzed to reveal the regional climate changes at the territory in North Kazakhstan over the last 58 years (i.e., 1950-2008). Peculiarities and conditions of snow cover formation and melting have been analyzed at territory of Northern Kazakhstan using surface and space monitoring data. Methods of both the geo-informational processing of remote probing data and statistical processing of databases on snow cover, air temperature and precipitations have been used. Analysis of snow cover observations data for territory of Northern Kazakhstan has shown that the stable snow cover might be observed since the middle of November till the beginning of April. In a few last decades the tendency is observed for longevity decrease of snow cover bedding that appears to be on the background air temperature increase and insignificant increase of cold period precipitations due to the later bedding of the snow cover and its earlier destruction. Peculiarities of atmospheric circulation in Atlantic-Eurasian sector of Northern Semi sphere and their influence of formation of snow cover at territory of Northern Kazakhstan. The higher longevity of the snow cover bedding is defined by the predominance of E form circulation and lower longevity - by the predominance of W+C circulation form. Analysis conducted of the highest height of snow cover bedding has shown that for period of 1936-2012 in the most cases the statistically reliable decreasing trends are observed with the linear trend coefficients of 0,50 - 0,60 cm/year. The method is offered for determination of probable characteristics of the snow cover decade height. Using data of space monitoring are allocated the frontiers of snow cover bedding for the period of snow melting 1982-2008 and the snow cover melting maps are developed. The results further confirm the proposition that snow cover availability is an important and limiting factor in the generation

  13. The influence of body condition on the fasting energy metabolism of nonpregnant, nonlactating dairy cows.

    PubMed

    Birnie, J W; Agnew, R E; Gordon, F J

    2000-06-01

    The objective of this experiment was to investigate the effect of cow body condition score on fasting heat production. Twelve nonpregnant, nonlactating Holstein-Friesian cows were selected from within the dairy herd at the Agricultural Research Institute of Northern Ireland. Six of these animals (group A) had condition scores > or = 4.5, and the remainder (group B) had condition scores <2. All cows were offered dried grass pellets at estimated maintenance energy level (0.58 MJ of metabolizable energy/kg(0.75)) for a minimum of 21 d. The diet also supplied 2.5 times the metabolizable protein requirement for maintenance. Following this, each cow underwent a 5-d fast in open circuit respiration calorimeters during which fasting heat production (FHP) was measured. On completion of measurement, group A was fed to reduce condition score (CS) below 2, while group B was fed to raise each individual condition score above 4.5. When the appropriate condition scores were achieved, dried grass pellets were again offered at maintenance for a minimum of 21 d, and fasting heat production was measured. It was observed that fasting heat production (MJ/kg(0.75)) was significantly higher for cows with low body condition (<2; ultrasonic fat depth < or = 2.9 mm) compared with cows displaying high body condition (> or = 4.5; ultrasonic fat depth > or = 8.2 mm). A linear relationship between condition score and fasting heat production (MJ/kg(0.75)) was defined by regression analysis as; FHP (MJ/kg(0.75)) = 0.501(SE 0.0121) - 0.030CS (SE 0.0035). PMID:10877386

  14. Influence of boundary conditions on the radiation emitted by an accelerated source

    SciTech Connect

    Alves, Danilo T.; Crispino, Luis C. B.; Lima, Marcelo C. de; Higuchi, Atsushi

    2010-03-15

    We analyze how the radiation emitted by an accelerated source minimally coupled to a massless real scalar field is influenced by the boundary conditions imposed on the field. We find that the response rate of the accelerated source in the presence of nearby boundaries parallel to the direction of the source's motion can be suppressed or enhanced depending on whether Dirichlet or Neumann boundary conditions are imposed on the field. We conclude that the response rate strongly depends on the kind of boundary conditions imposed, just as the sign of the Casimir force depends on the boundary conditions imposed on the field.

  15. Calcareous Bio-Concretions in the Northern Adriatic Sea: Habitat Types, Environmental Factors that Influence Habitat Distributions, and Predictive Modeling.

    PubMed

    Falace, Annalisa; Kaleb, Sara; Curiel, Daniele; Miotti, Chiara; Galli, Giovanni; Querin, Stefano; Ballesteros, Enric; Solidoro, Cosimo; Bandelj, Vinko

    2015-01-01

    Habitat classifications provide guidelines for mapping and comparing marine resources across geographic regions. Calcareous bio-concretions and their associated biota have not been exhaustively categorized. Furthermore, for management and conservation purposes, species and habitat mapping is critical. Recently, several developments have occurred in the field of predictive habitat modeling, and multiple methods are available. In this study, we defined the habitats constituting northern Adriatic biogenic reefs and created a predictive habitat distribution model. We used an updated dataset of the epibenthic assemblages to define the habitats, which we verified using the fuzzy k-means (FKM) clustering method. Redundancy analysis was employed to model the relationships between the environmental descriptors and the FKM membership grades. Predictive modelling was carried out to map habitats across the basin. Habitat A (opportunistic macroalgae, encrusting Porifera, bioeroders) characterizes reefs closest to the coastline, which are affected by coastal currents and river inputs. Habitat B is distinguished by massive Porifera, erect Tunicata, and non-calcareous encrusting algae (Peyssonnelia spp.). Habitat C (non-articulated coralline, Polycitor adriaticus) is predicted in deeper areas. The onshore-offshore gradient explains the variability of the assemblages because of the influence of coastal freshwater, which is the main driver of nutrient dynamics. This model supports the interpretation of Habitat A and C as the extremes of a gradient that characterizes the epibenthic assemblages, while Habitat B demonstrates intermediate characteristics. Areas of transition are a natural feature of the marine environment and may include a mixture of habitats and species. The habitats proposed are easy to identify in the field, are related to different environmental features, and may be suitable for application in studies focused on other geographic areas. The habitat model outputs

  16. Calcareous Bio-Concretions in the Northern Adriatic Sea: Habitat Types, Environmental Factors that Influence Habitat Distributions, and Predictive Modeling

    PubMed Central

    Falace, Annalisa; Kaleb, Sara; Curiel, Daniele; Miotti, Chiara; Galli, Giovanni; Querin, Stefano; Ballesteros, Enric; Solidoro, Cosimo; Bandelj, Vinko

    2015-01-01

    Habitat classifications provide guidelines for mapping and comparing marine resources across geographic regions. Calcareous bio-concretions and their associated biota have not been exhaustively categorized. Furthermore, for management and conservation purposes, species and habitat mapping is critical. Recently, several developments have occurred in the field of predictive habitat modeling, and multiple methods are available. In this study, we defined the habitats constituting northern Adriatic biogenic reefs and created a predictive habitat distribution model. We used an updated dataset of the epibenthic assemblages to define the habitats, which we verified using the fuzzy k-means (FKM) clustering method. Redundancy analysis was employed to model the relationships between the environmental descriptors and the FKM membership grades. Predictive modelling was carried out to map habitats across the basin. Habitat A (opportunistic macroalgae, encrusting Porifera, bioeroders) characterizes reefs closest to the coastline, which are affected by coastal currents and river inputs. Habitat B is distinguished by massive Porifera, erect Tunicata, and non-calcareous encrusting algae (Peyssonnelia spp.). Habitat C (non-articulated coralline, Polycitor adriaticus) is predicted in deeper areas. The onshore-offshore gradient explains the variability of the assemblages because of the influence of coastal freshwater, which is the main driver of nutrient dynamics. This model supports the interpretation of Habitat A and C as the extremes of a gradient that characterizes the epibenthic assemblages, while Habitat B demonstrates intermediate characteristics. Areas of transition are a natural feature of the marine environment and may include a mixture of habitats and species. The habitats proposed are easy to identify in the field, are related to different environmental features, and may be suitable for application in studies focused on other geographic areas. The habitat model outputs

  17. Calcareous Bio-Concretions in the Northern Adriatic Sea: Habitat Types, Environmental Factors that Influence Habitat Distributions, and Predictive Modeling.

    PubMed

    Falace, Annalisa; Kaleb, Sara; Curiel, Daniele; Miotti, Chiara; Galli, Giovanni; Querin, Stefano; Ballesteros, Enric; Solidoro, Cosimo; Bandelj, Vinko

    2015-01-01

    Habitat classifications provide guidelines for mapping and comparing marine resources across geographic regions. Calcareous bio-concretions and their associated biota have not been exhaustively categorized. Furthermore, for management and conservation purposes, species and habitat mapping is critical. Recently, several developments have occurred in the field of predictive habitat modeling, and multiple methods are available. In this study, we defined the habitats constituting northern Adriatic biogenic reefs and created a predictive habitat distribution model. We used an updated dataset of the epibenthic assemblages to define the habitats, which we verified using the fuzzy k-means (FKM) clustering method. Redundancy analysis was employed to model the relationships between the environmental descriptors and the FKM membership grades. Predictive modelling was carried out to map habitats across the basin. Habitat A (opportunistic macroalgae, encrusting Porifera, bioeroders) characterizes reefs closest to the coastline, which are affected by coastal currents and river inputs. Habitat B is distinguished by massive Porifera, erect Tunicata, and non-calcareous encrusting algae (Peyssonnelia spp.). Habitat C (non-articulated coralline, Polycitor adriaticus) is predicted in deeper areas. The onshore-offshore gradient explains the variability of the assemblages because of the influence of coastal freshwater, which is the main driver of nutrient dynamics. This model supports the interpretation of Habitat A and C as the extremes of a gradient that characterizes the epibenthic assemblages, while Habitat B demonstrates intermediate characteristics. Areas of transition are a natural feature of the marine environment and may include a mixture of habitats and species. The habitats proposed are easy to identify in the field, are related to different environmental features, and may be suitable for application in studies focused on other geographic areas. The habitat model outputs

  18. Influence of attentional focus on skilled motor performance: performance decrement under unfamiliar focus conditions.

    PubMed

    Maurer, Heiko; Munzert, Jörn

    2013-08-01

    Recent studies have demonstrated that the direction of attentional focus exerts a substantial influence on motor performance. We argue that in well-learned skills, this variable might be confounded with athletes' familiarity with focus conditions. We studied the effect of familiarity and the direction of attentional focus on performance in two experiments using 2 (familiarity)×2 (direction) within-subject designs. A significant main effect of familiarity-that is, better performance under familiar compared with unfamiliar focus conditions-confirmed the influence of familiarity on motor performance. Results are consistent with existing concepts, but lead to different consequences when applied to sport and exercise.

  19. Maps showing ground-water conditions in the northern part of the Chinle area, Apache County, Arizona, 1976

    USGS Publications Warehouse

    Levings, G.W.; Farrar, C.D.

    1977-01-01

    The northern part of the Chinle area includes about 3,000 sq mi in northeastern Arizona and is entirely in the Navajo Indian Reservation. The main source of water is from the several aquifers that are made up of one or more formations. The aquifers are stacked one on the other and generally are not hydraulically connected. Information on the maps includes depth to water, altitude of the water level, and chemical quality of the water. Scale 1:125,000. (Woodard-USGS)

  20. Length-weight relationships and condition factor of the eaglebeak pacu Ossubtus xinguense Jégu, 1992 (Characiformes, Serrasalmidae), an endangered species from Rio Xingu rapids, northern Brazil.

    PubMed

    Andrade, M C; Jesus, A J S; Giarrizzo, T

    2015-08-01

    This study reports on the length-weight relationships and condition factor for the endangered rheophilic fish Ossubtus xinguense Jégu from Rio Xingu rapids. This species is threatened by construction of the third largest hydroelectric in the world, the Belo Monte dam close to the city of Altamira, northern Brazil. Specimens were collected in the dry season between July 2012 and September 2012. Male specimens have body length larger than females, atypical in serrasalmid fishes, and different length-weight relationships were found between adult and juvenile specimens. This study presents the first biological characteristics for O. xinguense.

  1. Length-weight relationships and condition factor of the eaglebeak pacu Ossubtus xinguense Jégu, 1992 (Characiformes, Serrasalmidae), an endangered species from Rio Xingu rapids, northern Brazil.

    PubMed

    Andrade, M C; Jesus, A J S; Giarrizzo, T

    2015-08-01

    This study reports on the length-weight relationships and condition factor for the endangered rheophilic fish Ossubtus xinguense Jégu from Rio Xingu rapids. This species is threatened by construction of the third largest hydroelectric in the world, the Belo Monte dam close to the city of Altamira, northern Brazil. Specimens were collected in the dry season between July 2012 and September 2012. Male specimens have body length larger than females, atypical in serrasalmid fishes, and different length-weight relationships were found between adult and juvenile specimens. This study presents the first biological characteristics for O. xinguense. PMID:26691082

  2. Influence of body condition on influenza a virus infection in mallard ducks: Experimental infection data

    USGS Publications Warehouse

    Arsnoe, D.M.; Ip, H.S.; Owen, J.C.

    2011-01-01

    Migrating waterfowl are implicated in the global spread of influenza A viruses (IAVs), and mallards (Anas platyrhynchos) are considered a particularly important IAV reservoir. Prevalence of IAV infection in waterfowl peaks during autumn pre-migration staging and then declines as birds reach wintering areas. Migration is energetically costly and birds often experience declines in body condition that may suppress immune function. We assessed how body condition affects susceptibility to infection, viral shedding and antibody production in wild-caught and captive-bred juvenile mallards challenged with low pathogenic avian influenza virus (LPAIV) H5N9. Wild mallards (n = 30) were separated into three experimental groups; each manipulated through food availability to a different condition level (-20%, -10%, and normal ??5% original body condition), and captive-bred mallards (n = 10) were maintained at normal condition. We found that wild mallards in normal condition were more susceptible to LPAIV infection, shed higher peak viral loads and shed viral RNA more frequently compared to birds in poor condition. Antibody production did not differ according to condition. We found that wild mallards did not differ from captive-bred mallards in viral intensity and duration of infection, but they did exhibit lower antibody titers and greater variation in viral load. Our findings suggest that reduced body condition negatively influences waterfowl host competence to LPAIV infection. This observation is contradictory to the recently proposed condition-dependent hypothesis, according to which birds in reduced condition would be more susceptible to IAV infection. The mechanisms responsible for reducing host competency among birds in poor condition remain unknown. Our research indicates body condition may influence the maintenance and spread of LPAIV by migrating waterfowl. ?? 2011 Arsnoe et al.

  3. Influence of body condition on influenza A virus infection in mallard ducks: Experimental infection data

    USGS Publications Warehouse

    Arsnoe, Dustin M.; Ip, Hon S.; Owen, Jennifer C.

    2011-01-01

    Migrating waterfowl are implicated in the global spread of influenza A viruses (IAVs), and mallards (Anas platyrhynchos) are considered a particularly important IAV reservoir. Prevalence of IAV infection in waterfowl peaks during autumn pre-migration staging and then declines as birds reach wintering areas. Migration is energetically costly and birds often experience declines in body condition that may suppress immune function. We assessed how body condition affects susceptibility to infection, viral shedding and antibody production in wild-caught and captive-bred juvenile mallards challenged with low pathogenic avian influenza virus (LPAIV) H5N9. Wild mallards (n = 30) were separated into three experimental groups; each manipulated through food availability to a different condition level (-20%, -10%, and normal ±5% original body condition), and captive-bred mallards (n = 10) were maintained at normal condition. We found that wild mallards in normal condition were more susceptible to LPAIV infection, shed higher peak viral loads and shed viral RNA more frequently compared to birds in poor condition. Antibody production did not differ according to condition. We found that wild mallards did not differ from captive-bred mallards in viral intensity and duration of infection, but they did exhibit lower antibody titers and greater variation in viral load. Our findings suggest that reduced body condition negatively influences waterfowl host competence to LPAIV infection. This observation is contradictory to the recently proposed condition-dependent hypothesis, according to which birds in reduced condition would be more susceptible to IAV infection. The mechanisms responsible for reducing host competency among birds in poor condition remain unknown. Our research indicates body condition may influence the maintenance and spread of LPAIV by migrating waterfowl.

  4. Maternal condition does not influence birth sex ratios in anubis baboons (Papio anubis).

    PubMed

    Silk, Joan B; Strum, Shirley C

    2010-09-22

    Trivers and Willard predicted that when parental condition has differential effects on the fitness of male and female offspring, parents who are in good condition will bias investment toward the sex that benefits most from additional investment. Efforts to test predictions derived from Trivers and Willard's model have had mixed results, perhaps because most studies have relied on proxy measures of parental condition, such as dominance rank. Here, we examine the effects of female baboons condition on birth sex ratios and post-natal investment, based on visual assessments of maternal body condition. We find that local environmental conditions have significant effects on female condition, but maternal condition at conception has no consistent relationship with birth sex ratios. Mothers who are in poorer condition at the time of conception resume cycling significantly later than females who are in better condition, but the sex of their infants has no effect on the time to resumption of cycling. Thus, our findings provide strong evidence that maternal condition influences females' ability to reproduce, but females do not facultatively adjust the sex ratio of their offspring in relation to their dominance rank or current condition.

  5. Maternal Condition Does Not Influence Birth Sex Ratios in Anubis Baboons (Papio anubis)

    PubMed Central

    Silk, Joan B.; Strum, Shirley C.

    2010-01-01

    Trivers and Willard predicted that when parental condition has differential effects on the fitness of male and female offspring, parents who are in good condition will bias investment toward the sex that benefits most from additional investment. Efforts to test predictions derived from Trivers and Willard's model have had mixed results, perhaps because most studies have relied on proxy measures of parental condition, such as dominance rank. Here, we examine the effects of female baboons condition on birth sex ratios and post-natal investment, based on visual assessments of maternal body condition. We find that local environmental conditions have significant effects on female condition, but maternal condition at conception has no consistent relationship with birth sex ratios. Mothers who are in poorer condition at the time of conception resume cycling significantly later than females who are in better condition, but the sex of their infants has no effect on the time to resumption of cycling. Thus, our findings provide strong evidence that maternal condition influences females' ability to reproduce, but females do not facultatively adjust the sex ratio of their offspring in relation to their dominance rank or current condition. PMID:20877648

  6. Association of vectors and environmental conditions during the emergence of Peruvian horse sickness orbivirus and Yunnan orbivirus in northern Peru.

    PubMed

    Méndez-López, María R; Attoui, Houssam; Florin, David; Calisher, Charles H; Florian-Carrillo, J Christian; Montero, Stephanie

    2015-12-01

    Since 1983, cases of diseased donkeys and horses with symptoms similar to those produced by alphaviruses were identified in two departments in northern Peru; however serological testing ruled out the presence of those viruses and attempts to isolate an agent were also unproductive. In 1997, also in northern Peru, two new orbiviruses were discovered, each recognized as a causative agent of neurological diseases in livestock and domestic animals and, at the same time, mosquitoes were found to be infected with these viruses. Peruvian horse sickness virus (PHSV) was isolated from pools of culicid mosquitoes, Aedes serratus and Psorophora ferox, and Yunnan virus (YUOV) was isolated from Aedes scapularis in the subtropical jungle (upper jungle) located on the slope between the east side of the Andes and the Amazonian basin in the Department of San Martín. Both viruses later were recovered from mosquitoes collected above the slope between the west side of the Andes and the coast (Department of Piura) in humid subtropical areas associated with the Piura River basin. In this region, PHSV was isolated from Anopheles albimanus and YUOV was isolated from Ae. scapularis. We discuss the ecology of vector mosquitoes during the outbreaks in the areas where these mosquitoes were found.

  7. [Genetic base of Arabidopsis thaliana (L.) Heynh: fitness of plants for extreme conditions in northern margins of species range].

    PubMed

    Kurbidaeva, A S; Zaretskaia, M V; Soltabaeva, A D; Novokreshchenova, M G; Kupriianova, E V; Fedorenko, O M; Ezhova, T A

    2013-08-01

    Flowering time and vernalization requirement were studied in eight natural Karelian populations (KPs) of Arabidopsis thaliana. These KPs consisted of late-flowering plants with elevated expression of flowering repressor FLC and a reduced expression level of flowering activator SOC1 compared to the early-flowering ecotypes Dijon-M and Cvi-0. Despite variations in flowering time and the vernalization requirement among the KPs, two-week-old seedlings showed no changes in either the nucleotide sequence of the FRI gene or the relative expression levels of FRI and its target gene FLC that would be responsible for this variation. An analysis of abscisic acid (ABA) biosynthesis and catabolism genes (NCED3 and CYP707A2) did not show significant differences between late-flowering KPs and the early-flowering ecotypes Dijon-M and Cvi-0. Cold treatment (4 degrees C for 24 h) induced the expression of not only NCED3, but also RD29B, a gene involved in the ABA-dependent cold-response pathway. The relative levels of cold activation of these genes were nearly equal in all genotypes under study. Thus, the ABA-dependent cold response pathway does not depend on FLC expression. The lack of significant differences between northern populations, as well as the ecotypes Dijon-M (Europe) and Cvi-0 (Cape Verde Islands), indicates that this pathway is not crucial for fitness to the northern environment. PMID:25474881

  8. [Genetic base of Arabidopsis thaliana (L.) Heynh: fitness of plants for extreme conditions in northern margins of species range].

    PubMed

    2013-08-01

    Flowering time and vernalization requirement were studied in eight natural Karelian populations (KPs) of Arabidopsis thaliana. These KPs consisted of late-flowering plants with elevated expression of flowering repressor FLC and a reduced expression level of flowering activator SOC1 compared to the early-flowering ecotypes Dijon-M and Cvi-0. Despite variations in flowering time and the vernalization requirement among the KPs, two-week-old seedlings showed no changes in either the nucleotide sequence of the FRI gene or the relative expression levels of FRI and its target gene FLC that would be responsible for this variation. An analysis of abscisic acid (ABA) biosynthesis and catabolism genes (NCED3 and CYP707A2) did not show significant differences between late-flowering KPs and the early-flowering ecotypes Dijon-M and Cvi-0. Cold treatment (4 degrees C for 24 h) induced the expression of not only NCED3, but also RD29B, a gene involved in the ABA-dependent cold-response pathway. The relative levels of cold activation of these genes were nearly equal in all genotypes under study. Thus, the ABA-dependent cold response pathway does not depend on FLC expression. The lack of significant differences between northern populations, as well as the ecotypes Dijon-M (Europe) and Cvi-0 (Cape Verde Islands), indicates that this pathway is not crucial for fitness to the northern environment. PMID:25508660

  9. Past Experience Influences the Processing of Stimulus Compounds in Human Pavlovian Conditioning

    ERIC Educational Resources Information Center

    Melchers, Klaus G.; Lachnit, Harold; Shanks, David R.

    2004-01-01

    In two human skin conductance conditioning experiments we investigated whether processing of stimulus compounds can be influenced by past experience. Participants were either pre-trained with a discrimination problem that could be solved elementally (A+, B-, AB+, C- in Experiment 1 and A+, AB+, C-, CB- in Experiment 2) or one that required a…

  10. A critical review of social and structural conditions that influence HIV risk among Mexican deportees

    PubMed Central

    Pinedo, Miguel; Burgos, José Luis; Ojeda, Victoria D.

    2014-01-01

    Mexican migrants who are deported from the US may be at elevated risk for HIV infection. Deportations of Mexican migrants by the US have reached record numbers. We critically reviewed existing literature to assess how social and structural conditions in post-deportation settings can influence Mexican deported migrants' HIV risk. We also identify critical research gaps and make research recommendations. PMID:24583278

  11. Influence of boundary condition types on unstable density-dependent flow.

    PubMed

    Ataie-Ashtiani, Behzad; Simmons, Craig T; Werner, Adrian D

    2014-01-01

    Boundary conditions are required to close the mathematical formulation of unstable density-dependent flow systems. Proper implementation of boundary conditions, for both flow and transport equations, in numerical simulation are critical. In this paper, numerical simulations using the FEFLOW model are employed to study the influence of the different boundary conditions for unstable density-dependent flow systems. A similar set up to the Elder problem is studied. It is well known that the numerical simulation results of the standard Elder problem are strongly dependent on spatial discretization. This work shows that for the cases where a solute mass flux boundary condition is employed instead of a specified concentration boundary condition at the solute source, the numerical simulation results do not vary between different convective solution modes (i.e., plume configurations) due to the spatial discretization. Also, the influence of various boundary condition types for nonsource boundaries was studied. It is shown that in addition to other factors such as spatial and temporal discretization, the forms of the solute transport equation such as divergent and convective forms as well as the type of boundary condition employed in the nonsource boundary conditions influence the convective solution mode in coarser meshes. On basis of the numerical experiments performed here, higher sensitivities regarding the numerical solution stability are observed for the Adams-Bashford/Backward Trapezoidal time integration approach in comparison to the Euler-Backward/Euler-Forward time marching approach. The results of this study emphasize the significant consequences of boundary condition choice in the numerical modeling of unstable density-dependent flow. PMID:23659688

  12. Antibacterial Properties of Copper Nanoparticle Dispersions: Influence of Synthesis Conditions and Physicochemical Characteristics

    NASA Astrophysics Data System (ADS)

    Godymchuk, A.; Frolov, G.; Gusev, A.; Zakharova, O.; Yunda, E.; Kuznetsov, D.; Kolesnikov, E.

    2015-11-01

    The production of bactericidal plasters, bandages and medicines with the inclusion of copper nanoparticles and copper ions may have a great potential in terms of their biomedical application. The work considers the influence of the synthesis conditions, size, aggregation status, and charge of nanoparticles in aqueous solutions as well as the type of microorganisms to the antibacterial properties of water suspensions of electroexplosive copper nanoparticles in the conditions in vitro in relation to strains Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus. Water dispersions of copper nanoparticles were shown to inhibit the growth of test cells for both G+ and G- microbacteria but the degree of such an influence strongly depended on the type of a test strain. The authors have demonstrated that use of deeply purified water and alcohol-containing stabilizers at the synthesis of nanoparticles via metals electric erosion in the liquid prevents the copper nanoparticles coagulation and significantly influences on their physicochemical characteristics and, consequently, antibacterial properties.

  13. [Influence of transcranial electromagnetic brain stimulation on development of conditioned reflex in rats].

    PubMed

    Samoilov, V O; Shadrin, E B; Filippova, E B; Katsnelson, Ya; Backhoff, H; Eventov, M

    2015-01-01

    The influence of transcranial electromagnetic stimulation on the development of an active avoidance reflex with painful reinforcement in laboratory rats is investigated. It is shown, that an exposure of the rats' brain to electromagnetic radiation in the millimeter range ((λ = 5,6 and 7,1 mm), modulated as a series of low-frequency pulses, leads to a suppression of the development of the conditioned avoidance reflex occurred in 50% of cases. In other 25% of cases irradiation leads to inhibition of reflex development. Transcranial electromagnetic stimulation after intraperitoneal injection of the blocking agent of serotonergic receptors (kitryl) has no influence on reflex development. Electromagnetic brain stimulation does not influence reflex retention in the case when it has been acquired. Based on the data obtained it is assumed that transcranial electromagnetic stimulation promotes the development of serotonin, exerting an inhibiting effect on the formation of temporal bindings of the studied conditioned reflex.

  14. The influence of initial and surface boundary conditions on a model-generated January climatology

    NASA Technical Reports Server (NTRS)

    Wu, K. F.; Spar, J.

    1981-01-01

    The influence on a model-generated January climate of various surface boundary conditions, as well as initial conditions, was studied by using the GISS coarse-mesh climate model. Four experiments - two with water planets, one with flat continents, and one with mountains - were used to investigate the effects of initial conditions, and the thermal and dynamical effects of the surface on the model generated-climate. However, climatological mean zonal-symmetric sea surface temperature is used in all four runs over the model oceans. Moreover, zero ground wetness and uniform ground albedo except for snow are used in the last experiments.

  15. Metals, Parasites, and Environmental Conditions Affecting Breeding Populations of Spotted Salamanders (Ambystoma maculatum) in Northern Arkansas, USA.

    PubMed

    DeMali, Heather M; Trauth, Stanley E; Bouldin, Jennifer L

    2016-06-01

    The spotted salamander (Ambystoma maculatum) is indigenous to northern Arkansas, and several breeding sites are known to exist in the region. Spotted salamanders (n = 17) were collected and examined for parasites and only three females harbored nematodes (Physaloptera spp.). Chronic aquatic bioassays were conducted using water collected from eight breeding ponds during different hydroperiod events. No lethal or sublethal effects were measured in Ceriodaphnia dubia; however, decreased growth and survival were seen in Pimephales promelas. Aqueous, sediment, and salamander hepatic samples were analyzed for As, Cd, Cu, Pb, and Ni. Metal analysis revealed possible increased metal exposure following precipitation, with greatest metal concentrations measured in sediment samples. Hepatic metal concentrations were similar in parasitized and non-parasitized individuals, and greatest Pb concentrations were measured following normal precipitation events. Determining environmental stressors of amphibians, especially during their breeding and subsequent larval life stage, is imperative to improve species conservation. PMID:26886425

  16. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    SciTech Connect

    Wesley K. Wallace; Catherine L. Hanks; Michael T. Whalen; Jerry Jensen; Paul K. Atkinson; Joseph S. Brinton

    2000-05-01

    The Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding and lithostratigraphy on fracture patterns. (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. (4) The influence of lithostratigraphy and deformation on fluid flow. The results of field work during the summer of 1999 offer some preliminary insights: The Lisburne Limestone displays a range of symmetrical detachment fold geometries throughout the northeastern Brooks Range. The variation in fold geometry suggests a generalized progression in fold geometry with increasing shortening: Straight-limbed, narrow-crested folds at low shortening, box folds at intermediate shortening, and folds with a large height-to-width ratio and thickened hinges at high shortening. This sequence is interpreted to represent a progressive change in the dominant shortening mechanism from flexural-slip at low shortening to bulk strain at higher shortening. Structural variations in bed thickness occur throughout this progression. Parasitic folding accommodates structural thickening at low shortening and is gradually succeeded by penetrative strain as shortening increases. The amount of structural thickening at low to intermediate shortening may be inversely related to the local amount of structural thickening of the Kayak Shale, the incompetent unit that underlies the Lisburne. The Lisburne Limestone displays a different structural style in the south, across the boundary between the northeastern Brooks Range and the main axis of the Brooks Range fold

  17. Copper dynamics under alternating redox conditions is influenced by soil properties and contamination source

    NASA Astrophysics Data System (ADS)

    Balint, Ramona; Said-Pullicino, Daniel; Ajmone-Marsan, Franco

    2015-02-01

    Understanding the effect of soil redox conditions on contaminant dynamics is of significant importance for evaluating their lability, mobility and potential transfer to other environmental compartments. Under changing redox conditions, soil properties and constituents such as Fe and Mn (hydr)oxides and organic matter (OM) may influence the behavior of associated metallic elements (MEs). In this work, the redox-driven release and redistribution of Cu between different soil pools was studied in three soils having different contamination sources. This was achieved by subjecting soil columns to a series of alternating reducing and oxidizing cycles under non-limiting C conditions, and assessing their influence on soil pore water, leachate and solid phase composition. Results showed that, in all soils, alternating redox conditions led to an increase in the distribution of Cu in the more labile fractions, consequently enhancing its susceptibility to loss. This was generally linked to the redox-driven cycling of Fe, Mn and dissolved organic matter (DOM). In fact, results suggested that the reductive dissolution of Fe and Mn (hydr)oxides and subsequent reprecipitation as poorly-ordered phases under oxic conditions contributed to the release and mobilization of Cu and/or Cu-containing organometallic complexes. However, the behavior of Cu, as well as the mechanisms controlling Cu release and loss with redox cycling, was influenced by both soil properties (e.g. pH, contents of easily reducible Fe and Mn (hydr)oxides) and source of Cu contamination.

  18. Copper dynamics under alternating redox conditions is influenced by soil properties and contamination source.

    PubMed

    Balint, Ramona; Said-Pullicino, Daniel; Ajmone-Marsan, Franco

    2015-02-01

    Understanding the effect of soil redox conditions on contaminant dynamics is of significant importance for evaluating their lability, mobility and potential transfer to other environmental compartments. Under changing redox conditions, soil properties and constituents such as Fe and Mn (hydr)oxides and organic matter (OM) may influence the behavior of associated metallic elements (MEs). In this work, the redox-driven release and redistribution of Cu between different soil pools was studied in three soils having different contamination sources. This was achieved by subjecting soil columns to a series of alternating reducing and oxidizing cycles under non-limiting C conditions, and assessing their influence on soil pore water, leachate and solid phase composition. Results showed that, in all soils, alternating redox conditions led to an increase in the distribution of Cu in the more labile fractions, consequently enhancing its susceptibility to loss. This was generally linked to the redox-driven cycling of Fe, Mn and dissolved organic matter (DOM). In fact, results suggested that the reductive dissolution of Fe and Mn (hydr)oxides and subsequent reprecipitation as poorly-ordered phases under oxic conditions contributed to the release and mobilization of Cu and/or Cu-containing organometallic complexes. However, the behavior of Cu, as well as the mechanisms controlling Cu release and loss with redox cycling, was influenced by both soil properties (e.g. pH, contents of easily reducible Fe and Mn (hydr)oxides) and source of Cu contamination.

  19. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    SciTech Connect

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen; Michael T. Whalen

    2002-01-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. The Lisburne in the main axis of the Brooks Range is characteristically deformed into imbricate thrust sheets with asymmetrical hanging wall anticlines and footwall synclines. In contrast, the Lisburne in the northeastern Brooks Range is characterized by symmetrical detachment folds. The focus of our 2000 field studies was at the boundary between these structural styles in the vicinity of Porcupine Lake, in the Arctic National Wildlife Refuge. The northern edge of thrust-truncated folds in Lisburne is marked by a local range front that likely represents an eastward continuation of the central Brooks Range front. This is bounded to the north by a gently dipping panel of Lisburne with local asymmetrical folds. The leading edge of the flat panel is thrust over Permian to Cretaceous rocks in a synclinal depression. These younger rocks overlie symmetrically detachment-folded Lisburne, as is extensively exposed to the north. Six partial sections were measured in the Lisburne of the flat panel and local range front. The Lisburne here is about 700 m thick and is interpreted to consist primarily of the Wachsmuth and Alapah Limestones, with only a thin veneer of Wahoo Limestone. The Wachsmuth (200 m) is gradational between the underlying Missippian Kayak Shale and the overlying Mississippian Alapah, and

  20. Catchment and in-stream influences on iron-deposit chemistry, algal-bacterial biomass and invertebrate richness in upland streams, Northern Ireland.

    NASA Astrophysics Data System (ADS)

    Macintosh, Katrina Ann; Griffiths, David

    2013-04-01

    The density and composition of upland stream bed iron-deposits is affected by physical, chemical and biological processes. The basic chemical processes producing ochre deposits are well known. Mobilisation of iron and manganese is influenced by bedrock weathering, the presence of acidic and/or reducing conditions and the concentration of dissolved organic carbon. Ferromanganese-depositing bacteria are significant biogenic agents and can cause/enhance the deposition of metals in streams as (hydr)oxides. Metal concentrations from stream waters in two geological blocks in Northern Ireland were compared to determine the contributions of catchment characteristics and in-stream conditions. One block is composed of metamorphosed schist and unconsolidated glacial drift, with peat or peaty podzol (mainly humic) soils, while the other block consists of tertiary basalt with brown earth and gley soils. Water samples were collected from 52 stream sites and analysed for iron, manganese and aluminium as well as a range of other chemical determinands known to affect metal solubility. Stone deposit material was analysed for metal concentrations, organic matter content and epilithic algae, chlorophyll a concentration. Invertebrates were collected by area-standardised kick samples and animals identified to family and numbers counted. Higher conductivities and concentrations of bicarbonate, alkalinity, calcium and magnesium occurred on basalt than on schist. Despite higher iron and manganese oxide concentrations in basalt-derived non-humic soils, stream water concentrations were much lower and stone deposit concentrations only one third of those occurring on schist overlain by humic soils. Peat-generated acidity and the limited acid neutralising capacity of base-poor metamorphosed schist has resulted in elevated concentrations of metals and ochre deposit in surface waters. Algal biomass was determined by catchment level factors whereas in-stream conditions affected bacterial biomass

  1. Body size and condition influence migration timing of juvenile Arctic grayling

    USGS Publications Warehouse

    Heim, Kurt C.; Wipfli, Mark S.; Whitman, Matthew S.; Seitz, Andrew C

    2016-01-01

    Freshwater fishes utilising seasonally available habitats within annual migratory circuits time movements out of such habitats with changing hydrology, although individual attributes of fish may also mediate the behavioural response to environmental conditions. We tagged juvenile Arctic grayling in a seasonally flowing stream on the Arctic Coastal Plain in Alaska and recorded migration timing towards overwintering habitat. We examined the relationship between individual migration date, and fork length (FL) and body condition index (BCI) for fish tagged in June, July and August in three separate models. Larger fish migrated earlier; however, only the August model suggested a significant relationship with BCI. In this model, 42% of variability in migration timing was explained by FL and BCI, and fish in better condition were predicted to migrate earlier than those in poor condition. Here, the majority (33%) of variability was captured by FL with an additional 9% attributable to BCI. We also noted strong seasonal trends in BCI reflecting overwinter mass loss and subsequent growth within the study area. These results are interpreted in the context of size and energetic state-specific risks of overwinter starvation and mortality (which can be very high in the Arctic), which may influence individuals at greater risk to extend summer foraging in a risky, yet prey rich, habitat. Our research provides further evidence that heterogeneity among individuals within a population can influence migratory behaviour and identifies potential risks to late season migrants in Arctic beaded stream habitats influenced by climate change and petroleum development.

  2. Initial conditions influence the characteristics of ballistic contractions in the ankle dorsiflexors.

    PubMed

    Richartz, Chris; Lévénez, Morgan; Boucart, Julien; Duchateau, Jacques

    2010-11-01

    This study investigated the influence of different initial conditions on a subsequent fast (ballistic) isometric contraction of the ankle dorsiflexor muscles. Surface electromyograms (EMGs) of dorsiflexor and plantarflexor muscles were recorded during ballistic contractions performed without any pre-activation (BAL) and in ballistic contractions preceded by a sustained submaximal contraction (20% MVC) that was followed either by a rapid voluntary relaxation of the agonist muscle (VRBAL) or by a rapid antagonist (reversal) contraction (ARBAL). In the latter condition, three different antagonist torque levels were compared (25, 50 and 75% MVC). The results showed that the mean average rate of torque development was significantly (P < 0.001) greater for the ARBAL condition (968.5 ± 183.9% MVC/s) compared with the VRBAL (509.3 ± 78.7% MVC/s) and BAL (461.8 ± 79.9% MVC/s) conditions. Furthermore, the mean value recorded for VRBAL was significantly (P < 0.05) greater than for BAL condition. The faster increases in torque during the VRBAL and ARBAL conditions were associated with a greater agonist EMG activity. Compared with VRBAL, performance during the ARBAL condition was improved by a greater level of antagonist coactivation and, in some trials, by the presence of a silent EMG period between the end of the antagonist activation and the onset of the agonist ballistic contraction. Together, these results indicate that the initial conditions can have a substantial influence on the rate of torque development during ballistic contractions performed in isometric conditions.

  3. The influence of Ryukyu subduction on magma genesis in the Northern Taiwan Volcanic Zone and Middle Okinawa Trough - Evidence from boron isotopes

    NASA Astrophysics Data System (ADS)

    Pi, Ju-Lien; You, Chen-Feng; Wang, Kuo-Lung

    2016-09-01

    Boron (B) is an excellent geochemical tracer for investigating crustal recycling processes at convergent margins, due to its high fluid mobility under high P-T conditions, distinct elemental abundances and isotopic compositions in the mantle wedge and subducting slabs. The Northern Taiwan Volcanic Zone (NTVZ), wherein the nature of magma genesis has long been a topic of debate, is located at the rear side of the Okinawa Trough (OT), an atypical back-arc rift in the Ryukyu subduction system. In this study, B and B isotopes (δ11B) were measured in 19 volcanic rocks collected from the NTVZ and the middle Okinawa Trough (MOT) to assess the influence of the Ryukyu subduction system on magma genesis. The B concentrations in the MOT and NTVZ volcanic rocks are 5.8 to 13.6 mg/L and 2.2 to 48.6 mg/L, respectively. The large B abundances variation in the NTVZ was caused mainly by variable degrees of partial melting. The Nb/B and δ11B in the MOT have small ranges of 0.5 to 0.6 and - 2.7‰ to 0.2‰, respectively, whereas they range widely from 0.4 to 2.5 and from - 8.6‰ to 2.4‰, respectively in the NTVZ. These Nb/B values suggest that the magma contains a smaller subduction component than that normally observed in arcs, although this component is still more substantial than in a typical back-arc setting. The δ11B results indicate insignificant influence of the subducting Philippine Sea Plate at 2.6 Ma, but it becomes more substantial later in the NTVZ. The mixing proportions of sediment derived fluids in onshore volcanoes in the NTVZ imply a rather heterogeneous mantle wedge near the plate boundary, most likely due to either a heterogeneous source of slab derived fluids or more complicated mantle flow. A substantial B flux from the subducting slab in the incipient back-arc rifting in the MOT and NTVZ may reflect characteristics of a cold, steep and fast subducting slab, which may be capable of carrying volatiles efficiently into greater depth in subduction zones. The

  4. Heat budget for a waste lift placed under freezing conditions at a landfill operated in a northern climate.

    PubMed

    Bonany, James E; Van Geel, Paul J; Burak Gunay, H; Burkan Isgor, O

    2013-05-01

    A landfill operated in Ste. Sophie, Québec, Canada was instrumented to better understand the waste stabilization process in northern climates. Instrument bundles were placed within the waste to monitor temperature, settlement, oxygen, moisture content, total load, mounding of leachate and electrical conductivity. A finite element model was developed to simulate the heat budget for the first waste lift placed in the winter months and was calibrated using the first 10.5 months of collected temperature data. The calibrated model was then used to complete a sensitivity analysis for the various parameters that impact the heat budget. The results of the analysis indicated that the heat required for phase change to thaw the liquid fraction within frozen waste had a significant impact on the heat budget causing sections of waste to remain frozen throughout the simulation period. This was supported by the data collected to date at Ste. Sophie and by other researchers indicating that frozen waste placed during the winter months can remain frozen for periods in access of 1.5 years.

  5. SAND FLUX IN THE NORTHERN CHIHUAHUAN DESERT, NEW MEXICO, USA, AND THE INFLUENCE OF MESQUITE-DOMINATED LANDSCAPES

    EPA Science Inventory

    This study was designed to test two hypotheses: (1) that land dominated by mesquite (Prosopis glandulosa) is the most important area for active sand movement at the Jornada Experimental Range, located in the northern part of the Chihuahuan desert, and (2) that the most active san...

  6. Genotypic influence on aversive conditioning in honeybees, using a novel thermal reinforcement procedure.

    PubMed

    Junca, Pierre; Carcaud, Julie; Moulin, Sibyle; Garnery, Lionel; Sandoz, Jean-Christophe

    2014-01-01

    In Pavlovian conditioning, animals learn to associate initially neutral stimuli with positive or negative outcomes, leading to appetitive and aversive learning respectively. The honeybee (Apis mellifera) is a prominent invertebrate model for studying both versions of olfactory learning and for unraveling the influence of genotype. As a queen bee mates with about 15 males, her worker offspring belong to as many, genetically-different patrilines. While the genetic dependency of appetitive learning is well established in bees, it is not the case for aversive learning, as a robust protocol was only developed recently. In the original conditioning of the sting extension response (SER), bees learn to associate an odor (conditioned stimulus - CS) with an electric shock (unconditioned stimulus - US). This US is however not a natural stimulus for bees, which may represent a potential caveat for dissecting the genetics underlying aversive learning. We thus first tested heat as a potential new US for SER conditioning. We show that thermal stimulation of several sensory structures on the bee's body triggers the SER, in a temperature-dependent manner. Moreover, heat applied to the antennae, mouthparts or legs is an efficient US for SER conditioning. Then, using microsatellite analysis, we analyzed heat sensitivity and aversive learning performances in ten worker patrilines issued from a naturally inseminated queen. We demonstrate a strong influence of genotype on aversive learning, possibly indicating the existence of a genetic determinism of this capacity. Such determinism could be instrumental for efficient task partitioning within the hive.

  7. Genotypic Influence on Aversive Conditioning in Honeybees, Using a Novel Thermal Reinforcement Procedure

    PubMed Central

    Junca, Pierre; Carcaud, Julie; Moulin, Sibyle; Garnery, Lionel; Sandoz, Jean-Christophe

    2014-01-01

    In Pavlovian conditioning, animals learn to associate initially neutral stimuli with positive or negative outcomes, leading to appetitive and aversive learning respectively. The honeybee (Apis mellifera) is a prominent invertebrate model for studying both versions of olfactory learning and for unraveling the influence of genotype. As a queen bee mates with about 15 males, her worker offspring belong to as many, genetically-different patrilines. While the genetic dependency of appetitive learning is well established in bees, it is not the case for aversive learning, as a robust protocol was only developed recently. In the original conditioning of the sting extension response (SER), bees learn to associate an odor (conditioned stimulus - CS) with an electric shock (unconditioned stimulus - US). This US is however not a natural stimulus for bees, which may represent a potential caveat for dissecting the genetics underlying aversive learning. We thus first tested heat as a potential new US for SER conditioning. We show that thermal stimulation of several sensory structures on the bee’s body triggers the SER, in a temperature-dependent manner. Moreover, heat applied to the antennae, mouthparts or legs is an efficient US for SER conditioning. Then, using microsatellite analysis, we analyzed heat sensitivity and aversive learning performances in ten worker patrilines issued from a naturally inseminated queen. We demonstrate a strong influence of genotype on aversive learning, possibly indicating the existence of a genetic determinism of this capacity. Such determinism could be instrumental for efficient task partitioning within the hive. PMID:24828422

  8. The contact condition influence on stability and energy efficiency of quadruped robot

    NASA Astrophysics Data System (ADS)

    Lei, Jingtao; Wang, Tianmiao; Gao, Feng

    2008-10-01

    Quadruped robot has attribute of serial and parallel manipulator with multi-loop mechanism, with more DOF of each leg and intermittent contact with ground during walking, the trot gait of quadruped robot belongs to dynamic waking, compared to the crawl gait, the walking speed is higher, but the robot becomes unstable, it is difficult to keep dynamically stable walking. In this paper, we mainly analyze the condition for the quadruped robot to realize dynamically stable walking, establish centroid orbit equation based on ZMP (Zero Moment Point) stability theory, on the other hand , we study contact impact and friction influence on stability and energy efficiency. Because of the periodic contact between foots and ground, the contact impact and friction are considered to establish spring-damp nonlinear dynamics model. Robot need to be controlled to meet ZMP stability condition and contact constraint condition. Based on the virtual prototyping model, we study control algorithm considering contact condition, the contact compensator and friction compensator are adopted. The contact force and the influence of different contact conditions on the energy efficiency during whole gait cycle are obtained.

  9. Topological quantum scattering under the influence of a nontrivial boundary condition

    NASA Astrophysics Data System (ADS)

    Mota, Herondy

    2016-04-01

    We consider the quantum scattering problem of a relativistic particle in (2 + 1)-dimensional cosmic string spacetime under the influence of a nontrivial boundary condition imposed on the solution of the Klein-Gordon equation. The solution is then shifted as consequence of the nontrivial boundary condition and the role of the phase shift is to produce an Aharonov-Bohm-like effect. We examine the connection between this phase shift and the electromagnetic and gravitational analogous of the Aharonov-Bohm effect and compare the present results with previous ones obtained in the literature, also considering non-relativistic cases.

  10. Influence of Experimental Conditions on Electronic Tongue Results—Case of Valsartan Minitablets Dissolution

    PubMed Central

    Wesoły, Małgorzata; Kluk, Anna; Sznitowska, Małgorzata; Ciosek, Patrycja; Wróblewski, Wojciech

    2016-01-01

    A potentiometric electronic tongue was applied to study the release of valsartan from pharmaceutical formulations, i.e., minitablets uncoated and coated with Eudragit E. Special attention was paid to evaluate the influence of medium temperature and composition, as well as to compare the performances of the sensor arrays working in various hydrodynamic conditions. The drug dissolution profiles registered with the ion-sensitive electrodes were compared with standard dissolution tests performed with USP Apparatus 2 (paddle). Moreover, the signal changes of all sensors were processed by principal component analysis to visualize the release modifications, related to the presence of the coating agent. Finally, the importance and influence of the experimental conditions on the results obtained using potentiometric sensor arrays were discussed. PMID:27563904

  11. Complex influence of space environment on materials and electronic devices in the conditions of microgravity

    NASA Astrophysics Data System (ADS)

    Musabayev, T.; Zhantayev, Zh.; Grichshenko, V.

    2016-09-01

    The paper presents a new physical model describing the processes in materials and electronic devices under the influence of cosmic rays in microgravity. The model identifies specific features of formation of the area of radiation defects (ARD) in the electronic materials in microgravity. The mechanism of interaction between the ARD and memory modules in microgravity causing malfunction and failure of onboard electronics is considered. The results of failure of memory modules under real conditions are presented.

  12. Influence of temper condition on the nonlinear stress-strain behavior of boron-aluminum

    NASA Technical Reports Server (NTRS)

    Kennedy, J. M.; Herakovich, E. T.; Tenney, D. R.

    1977-01-01

    The influence of temper condition on the tensile and compressive stress-strain behavior for six boron-aluminum laminates was investigated. In addition to monotonic tension and compression tests, tension-tension, compression-compression, and tension--compression tests were conducted to study the effects of cyclic loading. Tensile strength results are a function of the laminate configuration; unidirectional laminates were affected considerably more than other laminates with some strength values increasing and others decreasing.

  13. Longevity of White Clover (Trifolium repens) Leaves, Stolons and Roots, and Consequences for Nitrogen Dynamics under Northern Temperate Climatic Conditions

    PubMed Central

    Sturite, Ievina; Henriksen, Trond Maukon; Breland, Tor Arvid

    2007-01-01

    Background and Aims White clover (Trifolium repens) is, due to nitrogen (N) fixation, important to the N dynamics of several northern temperate agroecosystems. This study aimed at monitoring growth and death of major white clover plant organs to assess their potential contribution to within-season N input and risk of off-season N losses. Methods White clover (‘Snowy’) was studied in a plot and root window experiment in southeast Norway (60°42′N, 10°51′E). Leaves, stolons and roots were tagged for lifespan measurement in harvested and unharvested stands during two experimental years. The availability of soil inorganic N was measured by plant root simulator (PRS™) probes. Key Results The longevity of leaves and petioles ranged from 21 to 86 d (mean = 59 d), of main stolon sections from 111 to over 677 d (mean = 411 d) and of roots from 27 to 621 d (mean = 290 d). About 60 % of the leaves produced had turned over by the end of the growing season and another 30 % had died or disappeared by the subsequent spring. Harvesting reduced the longevity of stolons and increased plant fragmentation, but did not decrease leaf or root lifespan or increase soil N availability. From the plant organ turnover data, it was estimated that the gross N input to the soil–plant system from white clover in pure stand during two growing seasons corresponded to a 2·5-fold increase over the total N in harvestable shoots. Conclusions The short lifespan and poor over-wintering of leaves showed their potential importance as a nitrogen source in the soil–plant ecosystem but also their potential contribution to the risk of off-season N losses. PMID:17495980

  14. ENSO response to high-latitude volcanic eruptions in the Northern Hemisphere: The role of the initial conditions

    NASA Astrophysics Data System (ADS)

    Pausata, Francesco S. R.; Karamperidou, Christina; Caballero, Rodrigo; Battisti, David S.

    2016-08-01

    A large ensemble of Earth System Model simulations is analyzed to show that high-latitude Northern Hemisphere eruptions give rise to El Niño-like anomalies in the winter following the eruption, the amplitude of which depends on the state of the tropical Pacific at the time of the eruption. The El Niño-like anomalies are almost three times larger when the eruption occurs during an incipient La Niña or during a neutral state compared to an incipient El Niño. The differential response results from stronger atmosphere-ocean coupling and extra-tropical feedbacks during an incipient La Niña compared to El Niño. Differences in the response continue through the second and third years following the eruption. When the eruption happens in a year of an incipient El Niño, a large cold (La Niña-like) anomaly develops in year 2; if the eruption occurs in a year of an incipient La Niña, no anomalies are simulated in year 2 and a La Niña-like response appears in year 3. After the El Niño-like anomaly in the first winter, the overall tendency of ENSO in the following 2 years is toward a La Niña state. Our results highlight the high sensitivity of tropical Pacific dynamics under volcanic forcing to the ENSO initial state and lay the groundwork for improved predictions of the global climatic response to high-latitude volcanic eruptions.

  15. Influence of sound-conditioning on noise-induced susceptibility of distortion-product otoacoustic emissionsa)

    PubMed Central

    Luebke, Anne E.; Stagner, Barden B.; Martin, Glen K.; Lonsbury-Martin, Brenda L.

    2015-01-01

    Cochlear damage caused by loud sounds can be attenuated by “sound-conditioning” methods. The amount of adaptation for distortion product otoacoustic emissions (DPOAEs) measured in alert rabbits previously predicted an ear's susceptibility to a subsequent noise exposure. The present study investigated if sound-conditioning influenced the robustness of such DPOAE adaptation, and if such conditioning elicited more protection by increasing the amount of DPOAE adaptation. Toward this end, rabbits were divided into two study groups: (1) experimental animals exposed to a sound-conditioning protocol, and (2) unconditioned control animals. After base-line measures, all rabbits were exposed to an overstimulation paradigm consisting of an octave band noise, and then re-assessed 3 weeks post-exposure to determine permanent changes in DPOAEs. A major result was that prior sound-conditioning protected reductions in DPOAE levels by an average of 10–15 dB. However, DPOAE adaptation decreased with sound-conditioning, so that such conditioning was no longer related to noise-induced reductions in DPOAEs. Together, these findings suggest that sound-conditioning affected neural pathways other than those that likely mediate DPOAE adaptation (e.g., medial olivocochlear efferent and/or middle-ear muscle reflexes). PMID:26233006

  16. The influence of different El Nino types on the northern hemisphere stratosphere simulated by the MPI-ESM

    NASA Astrophysics Data System (ADS)

    Bittner, Matthias; Timmreck, Claudia; Schmidt, Hauke

    2013-04-01

    It is known that the El Nino Southern Oscillation (ENSO), although it is mainly a tropospheric phenomenon, has an impact on the polar winter stratosphere [e.g. van Loon and Labitzke, 1987: Camp and Tung, 2007]. This has also been shown in simulations with general circulation models (GCM) [Sassi,et al. 2004, Manzini et al. 2006]. For a couple of years there are discussions about two different "flavors" of the the El Nino, the central Pacific (or Modoki) El Nino and the east Pacific El Nino [e.g. Wang and Weisberg, 2000; Yu and Kao, 2007; Ashok et al. 2007]. An observational study [Graf and Zanchettin, 2012] indicate that the polar vortex is more disturbed during EP El Ninos. Here we to investigate the influence of the equatorial sea surface temperatures on the stratosphere-troposphere coupling in the northern hemisphere winter season in a fully coupled atmosphere-ocean-land GCM. We use two versions of the Max-Planck-Institute for Meteorology model MPI-ESM, namely MPI-ESM-LR with lower T63 L47 atmosphere and GR15 ocean resolution and the MPI-ESM-MR with the same horizontal resolution in the atmosphere but a higher resolution in the vertical (L95) and in the ocean (TP04). To exclude effects of natural and anthropogenic forcing, we analyze a 1000 year coupled control simulation with pre-industrial greenhouse gas concentration and constant solar forcing (piControl). For comparison with reananlyis data we also analyze uncoupled atmosphere-only simulations with observed sea surface temperatures from 1979 until 2008 (AMIP). We compare three ways of defining El Nino: the central Pacific (CP), the east Pacific (EP) and the canonical Nino3.4 El Nino. We show to what extent the MPI-ESM is able to simulate these different types of El Nino and how they affect the polar stratosphere. The MPI-ESM model is in both versions capable of producing CP and EP El Ninos. However, the CP El Nino is dominant one in terms of magnitude and the EP El Nino has a relative small impact on global

  17. Influence of industrial processing on orange juice flavanone solubility and transformation to chalcones under gastrointestinal conditions.

    PubMed

    Gil-Izquierdo, Angel; Gil, María Isabel; Tomas-Barberan, Francisco Abraham; Ferreres, Federico

    2003-05-01

    Orange juice manufactured at industrial scale was subjected to digestion under in vitro gastrointestinal conditions (pH, temperature, and enzyme and chemical conditions) to evaluate the influence of individual industrial processing treatments on flavanone solubility, stability, and ability to permeate through a membrane under simulated physiological conditions. Four industrial processes including squeezing, standard pasteurization, concentration, and freezing were evaluated. Hand squeezing was compared with industrial squeezing. After in vitro gastrointestinal digestion of the orange juices, the flavanones able to permeate through a dialysis membrane, and those remaining in the retentate were evaluated by HPLC as were those present in the insoluble fraction. In all of the assayed orange juices, a high content of precipitated chalcones ( approximately 70% of the total flavanones) was formed under the physiological conditions of the gastrointestinal tract. Hand squeezing provided a higher concentration of flavanones in the permeated fraction and lower transformation to chalcones than industrial squeezing. Standard pasteurization did not influence the solubility and permeability of the orange juice flavanones and chalcones. Industrial concentration did not affect the amount of flavanones able to permeate but decreased the chalcones produced. Juices produced from frozen orange juice contained considerably smaller amounts of both soluble flavanones and insoluble chalcones.

  18. Long-term monthly statistics of mid-latitudinal NmF2 in the Northern geographic hemisphere during geomagnetically quiet and steadily low solar activity conditions

    NASA Astrophysics Data System (ADS)

    Pavlov, Anatoli; Pavlova, Nadezhda

    2016-07-01

    Long-term mid-latitude hourly values of NmF2 measured in 1957-2015 by 10 ionosondes (Point Arguello, Wallops Is., Boulder, de l'Ebre, Rome, Ottawa, Pruhonice, Dourbes, Slough, and Juliusruh) in the Northern geographic hemisphere were processed to select periods of geomagnetically quiet and low solar activity conditions to calculate several descriptive statistics of the noon NmF2 for each month, including the mathematical expectation, most probable value, arithmetic average, and arithmetic average median. The month-to-month variability of these descriptors allowed us to identify months of a year when they reach their extremes (maxima, minima). The calculated month-to-month variations of the NmF2 statistical parameters made it possible to study the winter anomaly and spring-autumn asymmetry in these statistical parameters.

  19. Long-term monthly statistics of mid-latitudinal NmF2 in the northern geographic hemisphere during geomagnetically quiet and steadily low solar activity conditions

    NASA Astrophysics Data System (ADS)

    Pavlov, A. V.; Pavlova, N. M.

    2016-05-01

    Long-term mid-latitude hourly values of NmF2 measured in 1957-2015 by 10 ionosondes in the Northern geographic hemisphere were processed to select periods of geomagnetically quiet and low solar activity conditions to calculate several descriptive statistics of the noon NmF2 for each month, including the mathematical expectation, most probable value, arithmetic average, and arithmetic average median. The month-to-month variability of these descriptors allowed us to identify months of a year when they reach their extremes (maxima, minima). The calculated month-to-month variations of the NmF2 statistical parameters made it possible to study the winter anomaly and spring-autumn asymmetry in these statistical parameters.

  20. Influence of extreme ambient temperatures and anaerobic conditions on Peltigera aphthosa (L.) Willd. viability

    NASA Astrophysics Data System (ADS)

    Dyakov, M. Yu.; Insarova, I. D.; Kharabadze, D. E.; Ptushenko, V. V.; Shtaer, O. V.

    2015-11-01

    Lichen are symbiotic systems constituted by heterotrophic fungi (mycobionts) and photosynthetic microorganism (photobionts). These organisms can survive under extreme stress conditions. The aim of this work was to study the influence of low (- 70 °C) or high (+ 70 °C) temperatures, temperature fluctuations from + 70 °C to - 70 °C, and anaerobic conditions on P. aphthosa (L.) Willd. viability. None of the studied stress factors affected significantly photosynthetic and respiratory activity of the thalli. No changes in morphology or ultrastructure of the cells were revealed for both photobiont and mycobiont components after extreme temperature treatment of P. aphthosa thalli. The data show the extreme tolerance of P. aphthosa to some stress factors inherent to the space flight conditions.

  1. The influence of cognitive ability and instructional set on causal conditional inference.

    PubMed

    Evans, Jonathan St B T; Handley, Simon J; Neilens, Helen; Over, David

    2010-05-01

    We report a large study in which participants are invited to draw inferences from causal conditional sentences with varying degrees of believability. General intelligence was measured, and participants were split into groups of high and low ability. Under strict deductive-reasoning instructions, it was observed that higher ability participants were significantly less influenced by prior belief than were those of lower ability. This effect disappeared, however, when pragmatic reasoning instructions were employed in a separate group. These findings are in accord with dual-process theories of reasoning. We also took detailed measures of beliefs in the conditional sentences used for the reasoning tasks. Statistical modelling showed that it is not belief in the conditional statement per se that is the causal factor, but rather correlates of it. Two different models of belief-based reasoning were found to fit the data according to the kind of instructions and the type of inference under consideration.

  2. Influences of solution chemical conditions on mobilization of TNT from contaminated soil

    SciTech Connect

    Dante, D.A.; Tiller, C.L.; Pennell, K.D.

    1996-12-31

    2,4,6-trinitrotoluene (TNT) and its byproducts are common contaminants on US military installations. Many potential remediation processes are in part limited by the transfer of TNT from the contaminated soil into the aqueous phase. The purpose of this research is to assess the release of TNT from contaminated soil under varying solution chemical conditions. In particular, influences of pH, aquatic natural organic matter, and addition of two surfactants is investigated. Uncontaminated soil was collected from a near-surface site at the Alabama Army Ammunition Plant and was artificially contaminated with TNT prior to the mobilization experiments. Results for the pH experiments show that more TNT is mobilized at neutral pH conditions than at low pH conditions. The presence of dissolved organic matter enhances the release of TNT from soil, but not by a large amount. Surfactant addition has the most significant effect on TNT mobilization.

  3. Geochemical characterisation of Tithonian-Berriasian Chia Gara organic-rich rocks in northern Iraq with an emphasis on organic matter enrichment and the relationship to the bioproductivity and anoxia conditions

    NASA Astrophysics Data System (ADS)

    Mohialdeen, Ibrahim M. J.; Hakimi, Mohammed Hail

    2016-02-01

    Tithonian-Berriasian Chia Gara organic-rich rocks, located in Kurdistan (northern Iraq), were analysed based on inorganic and organic geochemistry to define the origin, type of organic matter, and the influencing factors of organic matter (OM) enrichment, including the OM input and preservation, and their relationship to the paleoenvironment conditions. The δ13Corg values of the Chia Gara rocks range from -29.99‰ to -26.93‰, with average values of approximately -28.8‰, indicating that the organic matter has a predominantly marine origin. Enhanced biological productivity within the photic zone of the water column during deposition of the Chia Gara Fm. is indicated by consistently high organic carbon content in most samples (average 3 wt.%), as well as by bulk geochemical and biomarker characteristics. Major contributions by aquatic algae and microorganisms with a minor terrigenous organic matter contribution are indicated by the n-alkane distribution patterns and the composition of the hopanoids, steroids, and tricyclic terpenoids. Strongly reducing bottom water is indicated by low pristane/phytane ratios, homohopane distribution patterns, and the redox-sensitive trace elements geochemistry. Salinity stratification with alkaline bottom waters is indicated by high Sr/Ba ratios and the presence of gammacerane in the analysed Chia Gara samples. These data indicate that OM enrichment in the Tithonian-Berriasian Chia Gara rocks results from the combination of enhanced biological productivity and salinity stratification with anoxic bottom water conditions, which favoured OM preservation.

  4. Degradation of polycyclic aromatic hydrocarbons at low temperature under aerobic and nitrate-reducing conditions in enrichment cultures from northern soils.

    PubMed

    Eriksson, Mikael; Sodersten, Erik; Yu, Zhongtang; Dalhammar, Gunnel; Mohn, William W

    2003-01-01

    The potential for biodegradation of polycyclic aromatic hydrocarbons (PAHs)at low temperature and under anaerobic conditions is not well understood, but such biodegradation would be very useful for remediation of polluted sites. Biodegradation of a mixture of 11 different PAHs with two to five aromatic rings, each at a concentration of 10 micro g/ml, was studied in enrichment cultures inoculated with samples of four northern soils. Under aerobic conditions, low temperature severely limited PAH biodegradation. After 90 days, aerobic cultures at 20 degrees C removed 52 to 88% of the PAHs. The most extensive PAH degradation under aerobic conditions at 7 degrees C,53% removal, occurred in a culture from creosote-contaminated soil. Low temperature did not substantially limit PAH biodegradation under nitrate-reducing conditions. Under nitrate-reducing conditions,naphthalene, 2-methylnaphthalene, fluorene, and phenanthrene were degraded. The most extensive PAH degradation under nitrate-reducing conditions at 7 degrees C, 39% removal, occurred in a culture from fuel-contaminated Arctic soil. In separate transfer cultures from the above Arctic soil, incubated anaerobically at 7 degrees C, removal of 2-methylnaphthalene and fluorene was stoichiometrically coupled to nitrate removal. Ribosomal intergenic spacer analysis suggested that enrichment resulted in a few predominant bacterial populations,including members of the genera Acidovorax,Bordetella, Pseudomonas, Sphingomonas, and Variovorax. Predominant populations from different soils often included phylotypes with nearly identical partial 16S rRNA gene sequences (i.e., same genus) but never included phylotypes with identical ribosomal intergenic spacers (i.e., different species or subspecies). The composition of the enriched communities appeared to be more affected by presence of oxygen, than by temperature or source of the inoculum. PMID:12514005

  5. Degradation of Polycyclic Aromatic Hydrocarbons at Low Temperature under Aerobic and Nitrate-Reducing Conditions in Enrichment Cultures from Northern Soils

    PubMed Central

    Eriksson, Mikael; Sodersten, Erik; Yu, Zhongtang; Dalhammar, Gunnel; Mohn, William W.

    2003-01-01

    The potential for biodegradation of polycyclic aromatic hydrocarbons (PAHs) at low temperature and under anaerobic conditions is not well understood, but such biodegradation would be very useful for remediation of polluted sites. Biodegradation of a mixture of 11 different PAHs with two to five aromatic rings, each at a concentration of 10 μg/ml, was studied in enrichment cultures inoculated with samples of four northern soils. Under aerobic conditions, low temperature severely limited PAH biodegradation. After 90 days, aerobic cultures at 20°C removed 52 to 88% of the PAHs. The most extensive PAH degradation under aerobic conditions at 7°C, 53% removal, occurred in a culture from creosote-contaminated soil. Low temperature did not substantially limit PAH biodegradation under nitrate-reducing conditions. Under nitrate-reducing conditions, naphthalene, 2-methylnaphthalene, fluorene, and phenanthrene were degraded. The most extensive PAH degradation under nitrate-reducing conditions at 7°C, 39% removal, occurred in a culture from fuel-contaminated Arctic soil. In separate transfer cultures from the above Arctic soil, incubated anaerobically at 7°C, removal of 2-methylnaphthalene and fluorene was stoichiometrically coupled to nitrate removal. Ribosomal intergenic spacer analysis suggested that enrichment resulted in a few predominant bacterial populations, including members of the genera Acidovorax, Bordetella, Pseudomonas, Sphingomonas, and Variovorax. Predominant populations from different soils often included phylotypes with nearly identical partial 16S rRNA gene sequences (i.e., same genus) but never included phylotypes with identical ribosomal intergenic spacers (i.e., different species or subspecies). The composition of the enriched communities appeared to be more affected by presence of oxygen, than by temperature or source of the inoculum. PMID:12514005

  6. Northern contaminant mixtures induced morphological and functional changes in human coronary artery endothelial cells under culture conditions typifying high fat/sugar diet and ethanol exposure.

    PubMed

    Florian, Maria; Yan, Jin; Ulhaq, Saad; Coughlan, Melanie; Laziyan, Mahemuti; Willmore, William; Jin, Xiaolei

    2013-11-16

    It has been reported that Northern populations are exposed to mixtures of various environmental contaminants unique to the Arctic (Northern contaminant mixtures - NCM) at a large range of concentrations, depending on their geological location, age, lifestyle and dietary habits. To determine if these contaminants may contribute to a cardiovascular health risk, especially when combined with a high fat and sugar diet and ethanol exposure, we treated human coronary artery endothelial cells (HCAEC) with two mixtures of 4 organic (NCM1) or 22 organic and inorganic (NCM2) chemicals detected in Northerners' blood during 2004-2005 in the presence or absence of low-density lipoprotein (1.5mg/ml), very-low-density lipoprotein (1.0mg/ml) and glucose (10mmol/L) (LVG), and in the absence or presence of 0.1% ethanol. After 24h of exposure, cell morphology and markers of cytotoxicity and endothelial function were examined. NCM1 treatment did not affect cell viability, but increased cell size, disrupted cell membrane integrity, and decreased cell density, uptake of small peptides, release of endothelin-1 (ET-1) and plasminogen activator inhibitor (PAI), while causing no changes in endothelial nitric oxide synthase (eNOS) protein expression and nitric oxide (NO) release. In contrast, NCM2 decreased cell viability, total protein yield, uptake of small peptides, eNOS protein expression, and NO release and caused membrane damage, but caused no changes in the secretion of ET-1, prostacyclin and PAI. The presence of LVG and/or alcohol did or did not influence the effects of NCM1 or NCM2 depending on the endpoint and the mixture examined. These results suggested that the effects of one or one group of contaminants may be altered by the presence of other contaminants, and that with or without the interaction of high fat and sugar diet and/or ethanol exposure, NCMs at the concentrations used caused endothelial dysfunction in vitro. It remains to be investigated if these effects of NCMs also

  7. Persistent Organic Pollutants in Streamwater: Influence of Hydrological Conditions and Landscape Type.

    PubMed

    Josefsson, Sarah; Bergknut, Magnus; Futter, Martyn N; Jansson, Stina; Laudon, Hjalmar; Lundin, Lisa; Wiberg, Karin

    2016-07-19

    Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and hexachlorobenzene (HCB) in streamwater were measured in a remote catchment in northern Sweden and downstream to the Baltic Sea. Sampling took place at seven sites during two years and under different hydrological conditions: during the snow-free, snow-covered, and spring-flood seasons. Concentrations varied substantially between seasons and were up to 20 times higher during the spring flood compared to the preceding snow-covered period. The increase in concentrations with runoff was due to higher levels of particle-associated contaminants, while the dissolved concentrations remained stable. Particulate-contaminant concentrations were positively correlated primarily to suspended particulate matter (SPM) at sites in areas with a high land-cover fraction of sorted sediment. When upstream sampling locations were compared, a mire-dominated stream had higher concentrations and a lower retention of atmospherically deposited contaminants than a forest stream of the same catchment size. Contaminant concentrations (normalized to volume) did not increase consistently downstream despite the presence of several point sources. However, when normalized to the amount of SPM, concentrations were on average >20 times higher at the outlet in the Baltic Sea compared to the outlet from the remote catchment without point sources. PMID:27336735

  8. Experiments with Seasonal Forecasts of ocean conditions for the Northern region of the California Current upwelling system

    NASA Astrophysics Data System (ADS)

    Siedlecki, Samantha A.; Kaplan, Isaac C.; Hermann, Albert J.; Nguyen, Thanh Tam; Bond, Nicholas A.; Newton, Jan A.; Williams, Gregory D.; Peterson, William T.; Alin, Simone R.; Feely, Richard A.

    2016-06-01

    Resource managers at the state, federal, and tribal levels make decisions on a weekly to quarterly basis, and fishers operate on a similar timeframe. To determine the potential of a support tool for these efforts, a seasonal forecast system is experimented with here. JISAO’s Seasonal Coastal Ocean Prediction of the Ecosystem (J-SCOPE) features dynamical downscaling of regional ocean conditions in Washington and Oregon waters using a combination of a high-resolution regional model with biogeochemistry and forecasts from NOAA’s Climate Forecast System (CFS). Model performance and predictability were examined for sea surface temperature (SST), bottom temperature, bottom oxygen, pH, and aragonite saturation state through model hindcasts, reforecast, and forecast comparisons with observations. Results indicate J-SCOPE forecasts have measurable skill on seasonal timescales. Experiments suggest that seasonal forecasting of ocean conditions important for fisheries is possible with the right combination of components. Those components include regional predictability on seasonal timescales of the physical environment from a large-scale model, a high-resolution regional model with biogeochemistry that simulates seasonal conditions in hindcasts, a relationship with local stakeholders, and a real-time observational network. Multiple efforts and approaches in different regions would advance knowledge to provide additional tools to fishers and other stakeholders.

  9. Experiments with Seasonal Forecasts of ocean conditions for the Northern region of the California Current upwelling system.

    PubMed

    Siedlecki, Samantha A; Kaplan, Isaac C; Hermann, Albert J; Nguyen, Thanh Tam; Bond, Nicholas A; Newton, Jan A; Williams, Gregory D; Peterson, William T; Alin, Simone R; Feely, Richard A

    2016-01-01

    Resource managers at the state, federal, and tribal levels make decisions on a weekly to quarterly basis, and fishers operate on a similar timeframe. To determine the potential of a support tool for these efforts, a seasonal forecast system is experimented with here. JISAO's Seasonal Coastal Ocean Prediction of the Ecosystem (J-SCOPE) features dynamical downscaling of regional ocean conditions in Washington and Oregon waters using a combination of a high-resolution regional model with biogeochemistry and forecasts from NOAA's Climate Forecast System (CFS). Model performance and predictability were examined for sea surface temperature (SST), bottom temperature, bottom oxygen, pH, and aragonite saturation state through model hindcasts, reforecast, and forecast comparisons with observations. Results indicate J-SCOPE forecasts have measurable skill on seasonal timescales. Experiments suggest that seasonal forecasting of ocean conditions important for fisheries is possible with the right combination of components. Those components include regional predictability on seasonal timescales of the physical environment from a large-scale model, a high-resolution regional model with biogeochemistry that simulates seasonal conditions in hindcasts, a relationship with local stakeholders, and a real-time observational network. Multiple efforts and approaches in different regions would advance knowledge to provide additional tools to fishers and other stakeholders.

  10. Experiments with Seasonal Forecasts of ocean conditions for the Northern region of the California Current upwelling system.

    PubMed

    Siedlecki, Samantha A; Kaplan, Isaac C; Hermann, Albert J; Nguyen, Thanh Tam; Bond, Nicholas A; Newton, Jan A; Williams, Gregory D; Peterson, William T; Alin, Simone R; Feely, Richard A

    2016-01-01

    Resource managers at the state, federal, and tribal levels make decisions on a weekly to quarterly basis, and fishers operate on a similar timeframe. To determine the potential of a support tool for these efforts, a seasonal forecast system is experimented with here. JISAO's Seasonal Coastal Ocean Prediction of the Ecosystem (J-SCOPE) features dynamical downscaling of regional ocean conditions in Washington and Oregon waters using a combination of a high-resolution regional model with biogeochemistry and forecasts from NOAA's Climate Forecast System (CFS). Model performance and predictability were examined for sea surface temperature (SST), bottom temperature, bottom oxygen, pH, and aragonite saturation state through model hindcasts, reforecast, and forecast comparisons with observations. Results indicate J-SCOPE forecasts have measurable skill on seasonal timescales. Experiments suggest that seasonal forecasting of ocean conditions important for fisheries is possible with the right combination of components. Those components include regional predictability on seasonal timescales of the physical environment from a large-scale model, a high-resolution regional model with biogeochemistry that simulates seasonal conditions in hindcasts, a relationship with local stakeholders, and a real-time observational network. Multiple efforts and approaches in different regions would advance knowledge to provide additional tools to fishers and other stakeholders. PMID:27273473

  11. Experiments with Seasonal Forecasts of ocean conditions for the Northern region of the California Current upwelling system

    PubMed Central

    Siedlecki, Samantha A.; Kaplan, Isaac C.; Hermann, Albert J.; Nguyen, Thanh Tam; Bond, Nicholas A.; Newton, Jan A.; Williams, Gregory D.; Peterson, William T.; Alin, Simone R.; Feely, Richard A.

    2016-01-01

    Resource managers at the state, federal, and tribal levels make decisions on a weekly to quarterly basis, and fishers operate on a similar timeframe. To determine the potential of a support tool for these efforts, a seasonal forecast system is experimented with here. JISAO’s Seasonal Coastal Ocean Prediction of the Ecosystem (J-SCOPE) features dynamical downscaling of regional ocean conditions in Washington and Oregon waters using a combination of a high-resolution regional model with biogeochemistry and forecasts from NOAA’s Climate Forecast System (CFS). Model performance and predictability were examined for sea surface temperature (SST), bottom temperature, bottom oxygen, pH, and aragonite saturation state through model hindcasts, reforecast, and forecast comparisons with observations. Results indicate J-SCOPE forecasts have measurable skill on seasonal timescales. Experiments suggest that seasonal forecasting of ocean conditions important for fisheries is possible with the right combination of components. Those components include regional predictability on seasonal timescales of the physical environment from a large-scale model, a high-resolution regional model with biogeochemistry that simulates seasonal conditions in hindcasts, a relationship with local stakeholders, and a real-time observational network. Multiple efforts and approaches in different regions would advance knowledge to provide additional tools to fishers and other stakeholders. PMID:27273473

  12. Water conditions and geochemistry in northern Adriatic anoxia-prone areas and response of benthic faunas to oxygen deficiencies

    NASA Astrophysics Data System (ADS)

    Zuschin, Martin; Riedel, Bettina; Stachowitsch, Michael; Cermelj, Branko

    2010-05-01

    One predicted effect of global climate change, specifically global warming, is the increase in the temperatures and stratification of shallow coastal and estuarine systems. This, coupled with ongoing anthropogenic eutrophication, will exacerbate hypoxia and benthic mortalities, significantly damaging these critical marine ecosystems. These phenomena are particularly severe on sublitoral soft-bottoms such as the poorly sorted silty sands at the study site in the northern Adriatic Sea. We deployed a specially developed underwater chamber to artificially induce anoxia in situ. Our Experimental Anoxia Generating Unit (EAGU) is a large plexiglass chamber that combines a digital camera with oxygen/hydrogen sulphide/pH sensors along with flashes and battery packs. The unit can be deployed for up to five days to autonomously generate oxygen crises and quantify both physico-chemical parameters and benthic responses. The system is initially positioned in an "open" configuration (open-sided aluminium frame) over the benthic fauna ("control" experiment). After 24 h the EAGU is switched to its "closed" configuration (plexiglass enclosure) and repositioned over the same assemblage. In this contribution, we focus on the natural oxygen content, temperature and pH of bottom waters during summer, the course of oxygen decrease during our experiments and the onset of H2S development. Oxygen content of the bottom water, a few centimetres above the sediment-water interface, ranges from ~3.5-8 but is mostly between 4-6 ml l-1 during July to September of the study periods (2005 and 2006) and decreases to zero within ~1-3 days after initiation of our experiments. In parallel, H2S starts to develop at the onset of anoxia. Water temperatures at the bottom were stable during experiments and ranged from 18.5°C to 21.4°C, but pH decreased from 8.3 to 8.1 at the beginning to 7.9 to 7.7 at the end of the experiments. Sediment profiling indicates that the diffusive benthic boundary layer is

  13. Individual condition and stream temperature influence early maturation of rainbow and steelhead trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    McMillan, John R.; Dunham, J.B.; Reeves, G.H.; Mills, J.S.; Jordan, C.E.

    2012-01-01

    Alternative male phenotypes in salmonine fishes arise from individuals that mature as larger and older anadromous marine-migrants or as smaller and younger freshwater residents. To better understand the processes influencing the expression of these phenotypes we examined the influences of growth in length (fork length) and whole body lipid content in rainbow trout (Oncorhynchus mykiss). Fish were sampled from the John Day River basin in northeast Oregon where both anadromous ("steelhead") and freshwater resident rainbow trout coexist. Larger males with higher lipid levels had a greater probability of maturing as a resident at age-1+. Among males, 38% were maturing overall, and the odds ratios of the logistic model indicated that the probability of a male maturing early as a resident at age-1+ increased 49% (95% confidence interval (CI) = 23-81%) for every 5 mm increase in length and 33% (95% CI = 10-61%) for every 0.5% increase in whole body lipid content. There was an inverse association between individual condition and water temperature as growth was greater in warmer streams while whole body lipid content was higher in cooler streams. Our results support predictions from life history theory and further suggest that relationships between individual condition, maturation, and environmental variables (e.g., water temperature) are shaped by complex developmental and evolutionary influences.

  14. Individual condition and stream temperature influence early maturation of rainbow and steelhead trout, Oncorhynchus mykiss

    USGS Publications Warehouse

    McMillan, J.R.; Dunham, J.B.; Reeves, G.H.; Mills, J.S.; Jordan, C.E.

    2012-01-01

    Alternative male phenotypes in salmonine fishes arise from individuals that mature as larger and older anadromous marine-migrants or as smaller and younger freshwater residents. To better understand the processes influencing the expression of these phenotypes we examined the influences of growth in length (fork length) and whole body lipid content in rainbow trout (Oncorhynchus mykiss). Fish were sampled from the John Day River basin in northeast Oregon where both anadromous ("steelhead") and freshwater resident rainbow trout coexist. Larger males with higher lipid levels had a greater probability of maturing as a resident at age-1+. Among males, 38% were maturing overall, and the odds ratios of the logistic model indicated that the probability of a male maturing early as a resident at age-1+ increased 49% (95% confidence interval (CI) = 23-81%) for every 5 mm increase in length and 33% (95% CI = 10-61%) for every 0. 5% increase in whole body lipid content. There was an inverse association between individual condition and water temperature as growth was greater in warmer streams while whole body lipid content was higher in cooler streams. Our results support predictions from life history theory and further suggest that relationships between individual condition, maturation, and environmental variables (e. g., water temperature) are shaped by complex developmental and evolutionary influences. ?? 2011 Springer Science+Business Media B.V.

  15. Influence of incubation conditions on hydrolysis efficiency and iodine enrichment in baker's yeast.

    PubMed

    Dolińska, Barbara; Zieliński, Michał; Dobrzański, Zbigniew; Chojnacka, Katarzyna; Opaliński, Sebastian; Ryszka, Florian

    2012-06-01

    The influence of incubation conditions, enzyme type, hydrolysis time, and potassium iodide concentration on hydrolysis and iodine enrichment were studied in supernatant and pellets of Saccharomyces cervisiae hydrolysates. The type of enzyme used and incubation time significantly influence hydrolysis efficiency and protein concentration in supernatant and pellet. The highest protein hydrolysis efficiency was obtained by 24-h incubation with papain. Significantly lower values were observed for pepsin and autolysis. The potassium iodide concentration influences the iodine content of supernatant and pellet, but not hydrolysis. Iodide enrichment of supernatant and pellet depends on the concentration of iodide using during incubation. High concentration of iodide and long incubation times were the conditions for optimal iodide enrichment and high-protein hydrolysates. The optimal hydrolysis efficiency and iodine enrichment were obtained during 24-h incubation with papain in a 4.5-mM potassium iodide medium. The efficiency reached 98.22% with iodine concentrations of 2,664.91 and 9,200.67 μg/g iodine in pellet and supernatant, respectively. PMID:22237422

  16. Influence of syn-sedimentary faults on orogenic structures in a collisional belt: Insights from the inner zone of the Northern Apennines (Italy)

    NASA Astrophysics Data System (ADS)

    Brogi, Andrea

    2016-05-01

    This paper discusses the possible influence of syn-sedimentary structures on the development of orogenic structures during positive tectonic inversion in the inner Northern Apennines (Italy). Examples from key areas located in southern Tuscany provided original cartographic, structural and kinematics data for Late Oligocene-Early Miocene thrusts, organized in duplex systems, verging in the opposite direction of the foreland propagation (back-thrusts), which affected the Late Triassic-Oligocene sedimentary succession of the Tuscan Domain, previously affected by pre-orogenic structures. These latter consist of mesoscopic-to cartographic-scale Jurassic syn-sedimentary normal faults and extensional structures, which gave rise to effective stratigraphic lateral variation and mechanical heterogeneities. Structural analysis of both syn-sedimentary faults and back-thrusts were therefore compared in order to discuss the possible role of the pre-existing anisotropies in influencing the evolution of the back-thrusts. As a result, it can be reasonably proposed that back-thrusts trajectories and stacking pattern were controlled by relevant syn-sedimentary normal faults; these latter were reactivated, in some cases, if properly oriented. Such an issue adds new inputs for discussing the potential role of structural inheritance during tectonic inversions, and helps to better understand the processes suitable for the development of back-thrusts in the inner zones of orogenic belts, as it is the case of the inner Northern Apennines.

  17. Influence of tectonic terranes adjacent to Precambrian Wyoming province of petroleum source and reservoir rock stratigraphy in northern Rocky Mountain region

    SciTech Connect

    Tonnsen, J.J.

    1984-07-01

    The perimeter of the Archean Precambrian Wyoming province can be generally defined. A Proterozoic suture belt separates the province from the Archean Superior province to the east. The western margin of the Precambrian rocks lies under the western Overthrust belt, but the Precambrian province extends at least as far west as southwest Montana and southeast Idaho. The province is bounded on the north and south by more regionally extensive Proterozoic mobile belts. In the northern belt, Archean rocks have been remobilized by Proterozoic tectonic events, but the southern belt does not appear to contain rocks as old as Archean. The tectonic response of these Precambrian terranes to cratonic and continental margin vertical and horizontal forces has exerted a profound influence on Phanerozoic sedimentation and stratigraphic facies distributions. Petroleum source rock and reservoir rock stratigraphy of the Northern Rocky Mountain region has been correlated with this structural history. In particular, the Devonian, Permian, and Jurassic sedimentation patterns can be shown to have been influenced by articulation among the different terranes comprising the ancient substructure. Depositional patterns in the Chester-Morrow carbonate and clastic sequence in the Central Montana trough are also related to this substructure. Further, a correlation between these tectonic terranes and the localization of regional hydrocarbon accumulations has been observed and has been useful in basin analyses for exploration planning.

  18. Influence of uncertain boundary conditions and model structure on flood inundation predictions

    NASA Astrophysics Data System (ADS)

    Pappenberger, Florian; Matgen, Patrick; Beven, Keith J.; Henry, Jean-Baptiste; Pfister, Laurent; Fraipont, Paul

    2006-10-01

    In this study, the GLUE methodology is applied to establish the sensitivity of flood inundation predictions to uncertainty of the upstream boundary condition and bridges within the modelled region. An understanding of such uncertainties is essential to improve flood forecasting and floodplain mapping. The model has been evaluated on a large data set. This paper shows uncertainty of the upstream boundary can have significant impact on the model results, exceeding the importance of model parameter uncertainty in some areas. However, this depends on the hydraulic conditions in the reach e.g. internal boundary conditions and, for example, the amount of backwater within the modelled region. The type of bridge implementation can have local effects, which is strongly influenced by the bridge geometry (in this case the area of the culvert). However, the type of bridge will not merely influence the model performance within the region of the structure, but also other evaluation criteria such as the travel time. This also highlights the difficulties in establishing which parameters have to be more closely examined in order to achieve better fits. In this study no parameter set or model implementation that fulfils all evaluation criteria could be established. We propose four different approaches to this problem: closer investigation of anomalies; introduction of local parameters; increasing the size of acceptable error bounds; and resorting to local model evaluation. Moreover, we show that it can be advantageous to decouple the classification into behavioural and non-behavioural model data/parameter sets from the calculation of uncertainty bounds.

  19. On the Offshore Advection of Boundary-Layer Structures and the Influence on Offshore Wind Conditions

    NASA Astrophysics Data System (ADS)

    Dörenkämper, Martin; Optis, Michael; Monahan, Adam; Steinfeld, Gerald

    2015-06-01

    The coastal discontinuity imposes strong signals to the atmospheric conditions over the sea that are important for wind-energy potential. Here, we provide a comprehensive investigation of the influence of the land-sea transition on wind conditions in the Baltic Sea using data from an offshore meteorological tower, data from a wind farm, and mesoscale model simulations. Results show a strong induced stable stratification when warm inland air flows over a colder sea. This stratification demonstrates a strong diurnal pattern and is most pronounced in spring when the land-sea temperature difference is greatest. The strength of the induced stratification is proportional to this parameter and inversely proportional to fetch. Extended periods of stable stratification lead to increased influence of inertial oscillations and increased frequency of low-level jets. Furthermore, heterogeneity in land-surface roughness along the coastline is found to produce pronounced horizontal streaks of reduced wind speeds that under stable stratification are advected several tens of kilometres over the sea. The intensity and length of the streaks dampen as atmospheric stability decreases. Increasing sea surface roughness leads to a deformation of these streaks with increasing fetch. Slight changes in wind direction shift the path of these advective streaks, which when passing through an offshore wind farm are found to produce large fluctuations in wind power. Implications of these coastline effects on the accurate modelling and forecasting of offshore wind conditions, as well as damage risk to the turbine, are discussed.

  20. Investigation of the solar influence on clean and dusty CO2-ice under Martian conditions

    NASA Astrophysics Data System (ADS)

    Kaufmann, E.; Hagermann, A.; Wolters, S.

    2015-10-01

    CO2 is the main component of the Martian atmosphere. Therefore the polar caps are - depending on hemisphere and season - partially or totally covered with CO2-ice. In contrast to rock and soil surface layers, which absorb and reflect incoming solar radiation immediately at the surface, ices are partially transparent in the visible spectral range, while they are opaque in the infrared. These properties are responsible for the so-called "Solid- State Greenhouse Effect" (SSGE). The SSGE may have a major influence on the sublimation and recondensation of CO2 and its circulation in the Martian atmosphere. Our work will concentrate on the influence of the SSGE on CO2-ice under Martian like conditions.

  1. Extensive Analysis of GmFTL and GmCOL Expression in Northern Soybean Cultivars in Field Conditions

    PubMed Central

    Zhu, Jinlong; Lu, Mingyang; Chen, Fulu; Liu, Linpo; Xi, Zhang-Ying; Bachmair, Andreas; Chen, Qingshan; Fu, Yong-Fu

    2015-01-01

    The FLOWERING LOCUS T (FT) gene is a highly conserved florigen gene among flowering plants. Soybean genome encodes six homologs of FT, which display flowering activity in Arabidopsis thaliana. However, their contributions to flowering time in different soybean cultivars, especially in field conditions, are unclear. We employed six soybean cultivars with different maturities to extensively investigate expression patterns of GmFTLs (Glycine max FT-like) and GmCOLs (Glycine max CO-like) in the field conditions. The results show that GmFTL3 is an FT homolog with the highest transcript abundance in soybean, but other GmFTLs may also contribute to flower induction with different extents, because they have more or less similar expression patterns in developmental-, leaf-, and circadian-specific modes. And four GmCOL genes (GmCOL1/2/5/13) may confer to the expression of GmFTL genes. Artificial manipulation of GmFTL expression by transgenic strategy (overexpression and RNAi) results in a distinct change in soybean flowering time, indicating that GmFTLs not only impact on the control of flowering time, but have potential applications in the manipulation of photoperiodic adaptation in soybean. Additionally, transgenic plants show that GmFTLs play a role in formation of the first flowers and in vegetative growth. PMID:26371882

  2. Assessment of permafrost conditions under Northern Quebec's airports: an integrative approach for the development of adaptation strategies to climate warming

    NASA Astrophysics Data System (ADS)

    L'Hérault, E.; Allard, M.; Doré, G.; Barrette, C.; Verreault, J.; Sarrazin, D.; Doyon, J.; Guimond, A.

    2011-12-01

    Community airports in Nunavik were built between 1984 and 1992 and were designed by using a thick embankment of rock fill placed on undisturbed ground surface to prevent the thawing of the underlying permafrost. However, since around 2000, many of the runways show signs of permafrost disturbance as some localized differential settlements have begun to take place. With the anticipated rise of air temperature, the vulnerability of transportation infrastructures to permafrost degradation raises concerns. Several studies initiated by MTQ were undertaken by CEN to evaluate the permafrost conditions underneath airports. These studies provide valuable baseline information but also reveal the needs for a better understanding of the spatial variability of the surficial deposits, their geotechnical properties and permafrost conditions underneath embankments to assess its sensibility to thawing and to plan adaptation strategies in face of climate warming. A geomorphological and geotechnical investigation campaign, including surficial geology mapping using pre-construction air photographs and recovery of drilled frozen cores, was carried out in the summers 2008 and 2009 at eight airports. The impact of the runway embankments on surface drainage, snow drift accumulation and permafrost thawing was also determined. Stratigraphic information from drilling was used to reinterpret CCR and GPR surveys done in previous studies. High resolution cross-sections of the stratigraphy and permafrost conditions could then be drawn. Lab testing over undisturbed frozen samples was performed to determine the geotechnical properties of the different stratigraphic units encountered, particularly thaw consolidation ratios. Field measurements of ground temperatures and numerical modeling of the thermal regime of the embankment and subgrade were also performed to assess the potential impacts on permafrost stability alongside and beneath embankments under different climate change scenarios. Thermistor

  3. Influence of plasma conditions on the intensity ratio calibration curve during laser induced breakdown spectroscopy analysis.

    PubMed

    Kim, Chan-Kyu; In, Jung-Hwan; Lee, Seok-Hee; Jeong, Sungho

    2014-07-01

    Quantitative prediction of elemental concentration or concentration ratio of solid samples can be achieved by laser induced breakdown spectroscopy if a calibration curve that is little influenced by plasma conditions could be obtained. This work demonstrates that such a calibration curve is available for copper indium gallium diselenide (CuIn(1-x)Ga(x)Se₂) thin film solar cells for properly selected spectral lines. The possible changes of calibration curves based on the selected spectral lines are discussed in consideration of self-absorption in optically thick plasma and the dependency of spectral line properties on plasma temperature.

  4. Emission centers in ZnMoO4: Influence of growth conditions and decay characteristics

    NASA Astrophysics Data System (ADS)

    Spassky, D.; Nagirnyi, V.; Vielhauer, S.; Mägi, H.; Nasonov, S. G.; Shlegel, V. N.; Belsky, A.

    2016-09-01

    The influence of growth conditions and doping with tungsten on the luminescent properties of ZnMoO4 is studied. An enhancement of luminescence intensity in crystals grown from the melt with Mo excess was detected and the origin of the effect is discussed. Time-resolved spectroscopy of ZnMoO4 allowed to separate two emission bands at 480 and 560 nm, which are attributed to excitons self-trapped at two different types of regular MoO4 complexes.

  5. Interaction of hydrogen chloride with alumina. [influence of outgas and temperature conditions on adsorption

    NASA Technical Reports Server (NTRS)

    Bailey, R. R.; Wightman, J. P.

    1975-01-01

    The influence of outgas conditions and temperature on the adsorptive properties of two aluminas Alon-c and Al6sG were studied using adsorption isotherm measurements. Alon-C and Al6SG were characterized using X-ray powder diffraction, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and BET nitrogen surface areas. Some of these techniques were applied to two other aluminas but no isotherm data was obtained. Isotherm data and techniques applied to each alumina are summarized in tabular form.

  6. Influence of convective conditions in radiative peristaltic flow of pseudoplastic nanofluid in a tapered asymmetric channel

    NASA Astrophysics Data System (ADS)

    Hayat, T.; Iqbal, Rija; Tanveer, Anum; Alsaedi, A.

    2016-06-01

    This paper looks at the influences of magnetohydrodynamics (MHD) and thermal radiation on peristaltic transport of a pseudoplastic nanofluid in a tapered asymmetric channel. The tapered channel walls satisfy convective boundary conditions. The governing equations for the balance of mass, momentum, temperature and volume fraction for pseudoplastic nanofluid are first formulated and then utilized for long wavelength and small Reynolds number considerations. Effects of involved parameters on the flow characteristics have been plotted and examined. It is observed that the heat transfer Biot number shows a dual behavior on the temperature of nanofluid particles whereas the mass transfer Biot number with its increasing values enhances the fluid temperature.

  7. Casimir and hydrodynamic force influence on microelectromechanical system actuation in ambient conditions

    NASA Astrophysics Data System (ADS)

    Sedighi, Mehdi; Palasantzas, George

    2014-02-01

    Casimir and hydrodynamic dissipation forces can strongly influence the actuation of microelectromechanical systems in ambient conditions. The dissipative and stiction dynamics of an actuating system is shown to depend on surface physical processes related to fluid slip and the size of the actuating components. Using phase change materials the Casimir force magnitude can be modulated via amorphous-crystalline phase transitions. The dissipative motion between amorphous coated phase change material components can be changed towards stiction upon crystallization and suitable choice of restoring spring constants. By contrast, amorphization can augment switching from stiction to dissipative dynamics.

  8. Estimation of malaria incidence in northern Namibia in 2009 using Bayesian conditional-autoregressive spatial–temporal models☆

    PubMed Central

    Alegana, Victor A.; Atkinson, Peter M.; Wright, Jim A.; Kamwi, Richard; Uusiku, Petrina; Katokele, Stark; Snow, Robert W.; Noor, Abdisalan M.

    2013-01-01

    As malaria transmission declines, it becomes increasingly important to monitor changes in malaria incidence rather than prevalence. Here, a spatio-temporal model was used to identify constituencies with high malaria incidence to guide malaria control. Malaria cases were assembled across all age groups along with several environmental covariates. A Bayesian conditional-autoregressive model was used to model the spatial and temporal variation of incidence after adjusting for test positivity rates and health facility utilisation. Of the 144,744 malaria cases recorded in Namibia in 2009, 134,851 were suspected and 9893 were parasitologically confirmed. The mean annual incidence based on the Bayesian model predictions was 13 cases per 1000 population with the highest incidence predicted for constituencies bordering Angola and Zambia. The smoothed maps of incidence highlight trends in disease incidence. For Namibia, the 2009 maps provide a baseline for monitoring the targets of pre-elimination. PMID:24238079

  9. Effects of synoptic-scale circulation pattern and local land surface condition on fog at Kushiro, northern Japan

    NASA Astrophysics Data System (ADS)

    Sugimoto, S.; Sato, T.; Nakamura, K.

    2012-12-01

    Marine stratiform clouds are frequently observed over western North Pacific offshore of the northeast Japan during summer when warm southerly wind prevails over underlying cold ocean current. Such clouds often migrate over Kushiro located in the coastal area of eastern Hokkaido Island, north Japan and are recognized as sea fog. On the other hand, Kushiro is a middle-sized city with population of over 180,000 and a large wetland expands at the north of Kushiro city. The difference of land surface condition between the city and the wetland might cause heterogeneity of the sea fog distribution over land, via dissipation and regeneration process of fog. In this study, long-term visibility data for Kushiro are investigated to clarify the relationship between interannual variation of fog frequency (FF) and large-scale circulation patterns. Furthermore, frequency of fog/low-level cloud (LC) is identified using satellite images and sensitivity experiments changing land surface condition are conducted using meteorological regional model to understand an impact of land use on the local fog distribution and its physical processes. Monthly mean FF trends observed at Kushiro during 1931 to 2010 shows significant decline (-3.3 day per decade). Since late 1970s, the decline at Kushiro has been particularly remarkable in July and August in association with an increased number of years with very low FF. Analysis of radiosonde data has revealed the development of shallow moist layer under a strong inversion layer during fog occurrence because of abundant moisture supply from southerly wind. However, cold and dry northerly wind prevents the formation of inversion layer during fog-free days. Composite analysis of reanalysis data suggests that the low-level southerly wind toward northeast Japan is weaker in the low FF month of July than climatology owing to a southward shift of the North Pacific High (NPH) and stronger Okhotsk High. In August, eastward displacement or shrinking of the

  10. Assessment and monitoring of recreation impacts and resource conditions on mountain summits: examples from the Northern Forest, USA

    USGS Publications Warehouse

    Monz, Christopher A.; Marion, Jeffrey L.; Goonan, Kelly A.; Manning, Robert E.; Wimpey, Jeremy; Carr, Christopher

    2010-01-01

    Mountain summits present a unique challenge to manage sustainably: they are ecologically important and, in many circumstances, under high demand for recreation and tourism activities. This article presents recent advances in the assessment of resource conditions and visitor disturbance in mountain summit environments, by drawing on examples from a multiyear, interdisciplinary study of summits in the northeastern United States. Primary impact issues as a consequence of visitor use, such as informal trail formation, vegetation disturbance, and soil loss, were addressed via the adaption of protocols from recreation ecology studies to summit environments. In addition, new methodologies were developed that provide measurement sensitivity to change previously unavailable through standard recreation monitoring protocols. Although currently limited in application to the northeastern US summit environments, the methods presented show promise for widespread application wherever summits are in demand for visitor activities.

  11. Impacts of forest harvest on cold season land surface conditions and land-atmosphere interactions in northern Great Lakes states

    NASA Astrophysics Data System (ADS)

    Garcia, Matthew; Özdogan, Mutlu; Townsend, Philip A.

    2014-09-01

    Land cover change, including temporary disturbances such as forest harvests, can significantly affect established regimes of surface energy balance and moisture exchange, altering flux processes that drive weather and climate. We examined the impacts of forest harvest on winter land-atmosphere interactions in a temperate region using high-resolution numerical modeling methods in paired simulations. Using the WRF-ARW atmospheric model and the Noah land surface model, we simulated the balance of surface sensible and latent heat fluxes and the development and dissipation of a stable nocturnal boundary layer during generally calm synoptic conditions. Our results show reduced daily-average snow-covered land surface sensible heat flux (by 80%) and latent heat flux (by 60%) to the atmosphere in forest clearings due to albedo effects and rebalancing of the surface energy budget. We found a land surface cooling effect (-8 W m-2) in snow-covered cleared areas, consistent with prior modeling studies and conceptual understanding of the mechanisms for midlatitude deforestation to offset anthropogenic global warming at local scales. Results also demonstrate impacts of forest clearing on the passage of a weak cold front due to altered near-surface winds and boundary layer stability. We show significant differences in both surface conditions and fluxes between harvested and undisturbed forest areas. Our results demonstrate the potential utility of high-resolution remote sensing analyses to represent transient land cover changes in model simulations of weather and climate, which are usually undertaken at coarser resolutions and often overlook these changes at the land surface.

  12. The appearance of an oxygen-depleted condition on the Capitanian disphotic slope/basin in South China: Middle-Upper Permian stratigraphy at Chaotian in northern Sichuan

    NASA Astrophysics Data System (ADS)

    Saitoh, Masafumi; Isozaki, Yukio; Yao, Jianxin; Ji, Zhansheng; Ueno, Yuichiro; Yoshida, Naohiro

    2013-06-01

    The global environmental changes related to the end-Guadalupian (Permian) extinction have been recently studied in various shallow-marine sections in the world; however, no previous stratigraphic research focused on the sequence deposited in a relatively deep disphotic zone. In order to investigate the environmental changes in the disphotic zone during that interval, lithostratigraphy and secular changes in the sedimentary environment were analyzed for the ca. 150 m thick Guadalupian-Lopingian (Middle-Upper Permian) carbonates at Chaotian in northern Sichuan, South China. The upper Guadalupian Maokou Formation and the Lower Lopingian Wujiaping Formation are mostly composed of bioclastic limestone of a euphotic shelf facies and contain abundant shallow marine fossils, such as algae, corals, and fusulines. The topmost Maokou Formation (ca. 11 m thick) is unique in this section because it is composed of thinly bedded black mudstone/chert of a disphotic slope/basin facies with abundant radiolarians and ammonoids. The stratigraphic changes in litho- and bio-facies suggest a two-stepped transgression in the Capitanian followed by a great regression around the Guadalupian-Lopingian boundary (G-LB). Moreover, the stratigraphic changes in bioturbation, total organic carbon (TOC) content, and occurrence of framboidal pyrite suggest that the redox of the sedimentary environment at Chaotian changed drastically in accordance with newly clarified rapid sea-level fluctuations. In association with the Capitanian sea-level rise, the sedimentary environment shifted from an oxic shelf to an oxygen-depleted slope/basin, and again returned to an oxic shelf during the following great regression. The appearance of the oxygen-depleted condition on the Capitanian disphotic slope/basin in northern Sichuan is particularly important because it occurred clearly before the end-Guadalupian extinction event. It is also noteworthy that the oxygen-depleted seawater appeared for the first time on a

  13. Environmental Conditions Influence Allometric Patterns in the Blow Fly, Chrysomya albiceps

    PubMed Central

    Horenstein, M Battán; Peretti, Av

    2011-01-01

    The objective of this research was to study variations in allometry of body characters in females and males of two populations of blow flies, Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae), under different environmental conditions to establish patterns of morphological variation. Body size of both males and females in the experimental population was significantly higher than in the individuals of the natural population, indicating an important influence of food on body size. All genitalic and non-genitalic characters in males and females of the two populations showed a trend towards negative allometry rather than isometry. Allometric patterns were modified in both sexes and between populations. The data show generally larger allometric slopes in females than in males. We confirmed that the environmental conditions have an important effect on allometric patterns and body size. PMID:22224467

  14. Influence of Heat Treatment Conditions on the Properties of Vanadium Oxide Thin Films for Thermochromic Applications.

    PubMed

    Kim, Donguk; Kwon, Samyoung; Park, Young; Boo, Jin-Hyo; Nam, Sang-Hun; Joo, Yang Tae; Kim, Minha; Lee, Jaehyeong

    2016-05-01

    In present work, the effects of the heat treatment on the structural, optical, and thermochromic properties of vanadium oxide films were investigated. Vanadium dioxide (VO2) thin films were deposited on glass substrate by reactive pulsed DC magnetron sputtering from a vanadium metal target in mixture atmosphere of argon and oxygen gas. Various heat treatment conditions were applied in order to evaluate their influence on the crystal phases formed, surface morphology, and optical properties. The films were characterized by an X-ray diffraction (XRD) in order to investigate the crystal structure and identify the phase change as post-annealing temperature of 500-600 degrees C for 5 minutes. Surface conditions of the obtained VO2(M) films were analyzed by field emission scanning electron microscopy (FE-SEM) and the semiconductor-metal transition (SMT) characteristics of the VO2 films were evaluate by optical spectrophotometry in the UV-VIS-NIR, controlling temperature of the films.

  15. Review of parameters influencing the structural response of a submerged body under cavitation conditions

    NASA Astrophysics Data System (ADS)

    Escaler, X.; De La Torre, O.; Farhat, M.

    2015-12-01

    Submerged structures that operate under extreme flows are prone to suffer large scale cavitation attached to their surfaces. Under such conditions the added mass effects differ from the expected ones in pure liquids. Moreover, the existence of small gaps between the structure and surrounding bodies filled with fluid also influence the dynamic response. A series of experiments and numerical simulations have been carried out with a truncated NACA0009 hydrofoil mounted as a cantilever beam at the LMH-EPFL cavitation tunnel. The three first modes of vibration have been determined and analysed under various hydrodynamic conditions ranging from air and still water to partial cavitation and supercavitation. A remote nonintrusive excitation system with piezoelectric patches has been used for the experiments. The effects of the cavity properties and the lateral gap size on the natural frequencies and mode shapes have been determined. As a result, the significance of several parameters in the design of such structures is discussed.

  16. Influence of Heat Treatment Conditions on the Properties of Vanadium Oxide Thin Films for Thermochromic Applications.

    PubMed

    Kim, Donguk; Kwon, Samyoung; Park, Young; Boo, Jin-Hyo; Nam, Sang-Hun; Joo, Yang Tae; Kim, Minha; Lee, Jaehyeong

    2016-05-01

    In present work, the effects of the heat treatment on the structural, optical, and thermochromic properties of vanadium oxide films were investigated. Vanadium dioxide (VO2) thin films were deposited on glass substrate by reactive pulsed DC magnetron sputtering from a vanadium metal target in mixture atmosphere of argon and oxygen gas. Various heat treatment conditions were applied in order to evaluate their influence on the crystal phases formed, surface morphology, and optical properties. The films were characterized by an X-ray diffraction (XRD) in order to investigate the crystal structure and identify the phase change as post-annealing temperature of 500-600 degrees C for 5 minutes. Surface conditions of the obtained VO2(M) films were analyzed by field emission scanning electron microscopy (FE-SEM) and the semiconductor-metal transition (SMT) characteristics of the VO2 films were evaluate by optical spectrophotometry in the UV-VIS-NIR, controlling temperature of the films. PMID:27483853

  17. Influence of drying conditions on the quality of Origanum syriacum L.

    PubMed

    Hanna Wakim, L; El Beyrouthy, M; Mnif, W; Dhifi, W; Salman, M; Bassal, A

    2013-08-01

    The temperature and the speed of drying may affect the quality of the end product of medicinal plants. In addition, ecotypes and chemotypes could be factors influencing this quality. Thus, the aim of our study was to explore various techniques of drying of Origanum syriacum L., which is considered as a main ingredient in the Lebanese diet. For all these reasons, we decided to study two types of O. syriacum originating from Rkai and Ibrine regions on which analyses were carried out. In view of our results, a moderate temperature, in the absence of light, is more favourable for the safeguarding of the flavours and chlorophylls. On the other hand, these conditions seem to be unsuitable for other substances. In order to clarify the optimal conditions for drying of O. syriacum to lead to a product of quality, the choice of a technique of suitable dehydration seems to be delicate. PMID:23231649

  18. Influence of emulsion composition and spray-drying conditions on microencapsulation of tilapia oil.

    PubMed

    Huang, Hui; Hao, Shuxian; Li, Laihao; Yang, Xianqing; Cen, Jianwei; Lin, Wanling; Wei, Ya

    2014-09-01

    The influence of processing conditions on the microencapsulation of tilapia oil by spray drying was studied. Trehalose, gelatin, sucrose and xanthan were used as emulsion composition. The experimental parameters of spray drying such as inlet air temperature, solid content, drying air flow rate and atomizing pressure were optimized using a central composite design. Encapsulation efficiency and lipid oxidation were determined. Bulk density, powder morphology and particle size were also analyzed. Trehalose improved the glass transition temperature of wall material significantly and prevented the oxidation of the fish oil. Encapsulation efficiency reached a maximum of 90 % under optimum conditions with an inlet air temperature of 121 °C, a drying air flow rate of 0.65 m(3)/min and a spray pressure of 100 kPa.

  19. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    SciTech Connect

    Wallace, W.K.; Hanks, C.L.; Whalen, M.T.; Jensen, J.; Atkinson, P.K.; Brinton, J.S.

    2001-01-09

    The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding and lithostratigraphy on fracture patterns, (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics, and (4) The influence of lithostratigraphy and deformation on fluid flow.

  20. The Influence of Atmospheric Conditions on the Production of Ozone during VOC Oxidation

    NASA Astrophysics Data System (ADS)

    Coates, J.; Butler, T. M.

    2015-12-01

    Tropospheric ozone is a short-lived climate forcing pollutant that is detrimental to human health and crop growth. Reactions involving volatile organic compounds (VOC) and nitrogen oxides (NOx) in the presence of sunlight produce ozone. Ozone production is a non-linear function of the concentrations of both NOx and VOC, with VOC acting as the "fuel" for ozone production and NOx as the "catalyst". Different VOC, due to their differing structure and carbon content, have different maximum potential to produce ozone. Due to different degrees of reactivity, VOC also differ in the time taken to reach this maximum ozone production potential under ideal conditions. Ozone production is also influenced by meteorological factors such as radiation, temperature, advection and mixing, which may alter the rate of ozone production, and the degree to which VOC are able to reach their maximum ozone production potential. Identifying the chemical and meteorological processes responsible for controlling the degree to which VOC are able to reach their maximum ozone production potential could inform decisions on emission control to efficiently tackle high levels of tropospheric ozone. In this study we use a boxmodel to determine the chemical processes affecting ozone production under different meteorological and chemical conditions. The chemistry scheme used by the boxmodel is "tagged" for each initial VOC enabling attribution of ozone production to its VOC source. We systematically vary a number of meteorological parameters along with the source of NOx within the box model to simulate a range of atmospheric conditions. These simulations are compared with a control simulation done under conditions of maximum ozone formation to determine which parameters affect the rate at which VOC produce ozone and the extent to which they reach their maximum potential to produce ozone. We perform multi-day simulations in order to examine whether these processes can influence ozone production over

  1. Effects of fungal inocula and habitat conditions on alder and eucalyptus leaf litter decomposition in streams of northern Spain.

    PubMed

    Pérez, Javier; Galán, Javier; Descals, Enrique; Pozo, Jesús

    2014-02-01

    We investigated how fungal decomposer (aquatic hyphomycetes) communities colonizing alder and eucalyptus leaf litter respond to changes in habitat characteristics (transplantation experiment). We examined the breakdown of leaf materials and the associated fungal communities at two contrasting sites, a headwater stream (H) and a midreach (M). Agroforestry increased from headwater to midreach. One month after the start of experiments at both sites, some leaf samples from the midreach site were transplanted to the headwater site (M-H treatment). Although both sites showed similar dissolved inorganic nutrient concentrations, eucalyptus leaves initially incubated at the midreach site (M, M-H) increased their breakdown rate compared to those incubated along the experiment at the headwater site (H). Alder breakdown rate was not enhanced, suggesting that their consumption was not limited by nutrient availability. Sporulation rates clearly differed between leaf types (alder > eucalyptus) and streams (H > M), but no transplantation effect was detected. When comparing conidial assemblages after transplantation, an inoculum effect (persistence of early colonizing species) was clear in both leaf species. Substrate preference and shifts in the relative importance of some fungal species along the process were also observed. Overall, our results support the determining role of the initial conditioning phase on the whole litter breakdown process, highlighting the importance of intrinsic leaf characteristics and those of the incubation habitat.

  2. Decline in condition of gorgonian octocorals on mesophotic reefs in the northern Gulf of Mexico: before and after the Deepwater Horizon oil spill

    NASA Astrophysics Data System (ADS)

    Etnoyer, Peter J.; Wickes, Leslie N.; Silva, Mauricio; Dubick, J. D.; Balthis, Len; Salgado, Enrique; MacDonald, Ian R.

    2016-03-01

    Hard-bottom `mesophotic' reefs along the `40-fathom' (73 m) shelf edge in the northern Gulf of Mexico were investigated for potential effects of the Deepwater Horizon (DWH) oil spill from the Macondo well in April 2010. Alabama Alps Reef, Roughtongue Reef, and Yellowtail Reef were near the well, situated 60-88 m below floating oil discharged during the DWH spill for several weeks and subject to dispersant applications. In contrast, Coral Trees Reef and Madison Swanson South Reef were far from the DWH spill site and below the slick for less than a week or not at all, respectively. The reefs were surveyed by ROV in 2010, 2011, and 2014 and compared to similar surveys conducted one and two decades earlier. Large gorgonian octocorals were present at all sites in moderate abundance including Swiftia exserta, Hypnogorgia pendula, Thesea spp., and Placogorgia spp. The gorgonians were assessed for health and condition in a before-after-control-impact (BACI) research design using still images captured from ROV video transects. Injury was modeled as a categorical response to proximity and time using logistic regression. Condition of gorgonians at sites near Macondo well declined significantly post-spill. Before the spill, injury was observed for 4-9 % of large gorgonians. After the spill, injury was observed in 38-50 % of large gorgonians. Odds of injury for sites near Macondo were 10.8 times higher post-spill, but unchanged at far sites. The majority of marked injured colonies in 2011 declined further in condition by 2014. Marked healthy colonies generally remained healthy. Background stresses to corals, including fishing activity, fishing debris, and coral predation, were noted during surveys, but do not appear to account for the decline in condition at study sites near Macondo well.

  3. Warfare rather than agriculture as a critical influence on fires in the late Holocene, inferred from northern Vietnam.

    PubMed

    Li, Zhen; Saito, Yoshiki; Dang, Phong X; Matsumoto, Eiji; Vu, Quang Lan

    2009-07-14

    Fire has played an essential role in the development of human civilization. Most previous research suggests that frequent-fire regimes in the late Holocene were associated with intensification of human activities, especially agriculture development. Here, we analyze fire regimes recorded in the Song Hong delta area of Vietnam over the past 5,000 years. In the prehistoric period, 2 long-term, low-charcoal abundance periods have been linked to periods of low humidity and cool climate, and 5 short-term fire regimes of 100-150 years in duration occurred at regular intervals of approximately 700 years. However, over the last 1,500 years, the number, frequency, and intensity of fire regimes clearly increased. Six intensified-fire regime periods in northern Vietnam during this time coincided with changes of Vietnamese dynasties and associated warfare and unrest. In contrast, agricultural development supported by rulers of stable societies at this time does not show a positive correlation with intensified-fire regime periods. Thus, warfare rather than agriculture appears to have been a critical factor contributing to fire regimes in northern Vietnam during the late Holocene.

  4. Assessing the genetic influence of ancient sociopolitical structure: micro-differentiation patterns in the population of Asturias (Northern Spain).

    PubMed

    Pardiñas, Antonio F; Roca, Agustín; García-Vazquez, Eva; López, Belén

    2012-01-01

    The human populations of the Iberian Peninsula are the varied result of a complex mixture of cultures throughout history, and are separated by clear social, cultural, linguistic or geographic barriers. The stronger genetic differences between closely related populations occur in the northern third of Spain, a phenomenon commonly known as "micro-differentiation". It has been argued and discussed how this form of genetic structuring can be related to both the rugged landscape and the ancient societies of Northern Iberia, but this is difficult to test in most regions due to the intense human mobility of previous centuries. Nevertheless, the Spanish autonomous community of Asturias shows a complex history which hints of a certain isolation of its population. This, joined together with a difficult terrain full of deep valleys and steep mountains, makes it suitable for performing a study of genetic structure, based on mitochondrial DNA and Y-Chromosome markers. Our analyses do not only show that there are micro-differentiation patterns inside the Asturian territory, but that these patterns are strikingly similar between both uniparental markers. The inference of barriers to gene flow also indicates that Asturian populations from the coastal north and the mountainous south seem to be relatively isolated from the rest of the territory. These findings are discussed in light of historic and geographic data and, coupled with previous evidence, show that the origin of the current genetic patterning might indeed lie in Roman and Pre-Roman sociopolitical divisions.

  5. Assessing the Genetic Influence of Ancient Sociopolitical Structure: Micro-differentiation Patterns in the Population of Asturias (Northern Spain)

    PubMed Central

    Pardiñas, Antonio F.; Roca, Agustín; García-Vazquez, Eva; López, Belén

    2012-01-01

    The human populations of the Iberian Peninsula are the varied result of a complex mixture of cultures throughout history, and are separated by clear social, cultural, linguistic or geographic barriers. The stronger genetic differences between closely related populations occur in the northern third of Spain, a phenomenon commonly known as “micro-differentiation”. It has been argued and discussed how this form of genetic structuring can be related to both the rugged landscape and the ancient societies of Northern Iberia, but this is difficult to test in most regions due to the intense human mobility of previous centuries. Nevertheless, the Spanish autonomous community of Asturias shows a complex history which hints of a certain isolation of its population. This, joined together with a difficult terrain full of deep valleys and steep mountains, makes it suitable for performing a study of genetic structure, based on mitochondrial DNA and Y-Chromosome markers. Our analyses do not only show that there are micro-differentiation patterns inside the Asturian territory, but that these patterns are strikingly similar between both uniparental markers. The inference of barriers to gene flow also indicates that Asturian populations from the coastal north and the mountainous south seem to be relatively isolated from the rest of the territory. These findings are discussed in light of historic and geographic data and, coupled with previous evidence, show that the origin of the current genetic patterning might indeed lie in Roman and Pre-Roman sociopolitical divisions. PMID:23209673

  6. Potential Influence of Climate-Induced Vegetation Shifts on Future Land Use and Associated Land Carbon Fluxes in Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Kicklighter, D. W.; Cai, Y.; Zhuang, Q.; Parfenova, E. I.; Paltsev, S.; Sokolov, A. P.; Melillo, J. M.; Reilly, J. M.; Tchebakova, N. M.; Lu, X.

    2014-12-01

    Climate change will alter ecosystem metabolism and may lead to a redistribution of vegetation and changes in fire regimes in Northern Eurasia over the 21st century. Land management decisions will interact with these climate-driven changes to reshape the region's landscape. Here we present an assessment of the potential consequences of climate change on land use and associated land carbon sink activity for Northern Eurasia in the context of climate-induced vegetation shifts. Under a 'business-as-usual' scenario, climate-induced vegetation shifts allow expansion of areas devoted to food crop production (15%) and pastures (39%) over the 21st century. Under a climate stabilization scenario, climate-induced vegetation shifts permit expansion of areas devoted to cellulosic biofuel production (25%) and pastures (21%), but reduce the expansion of areas devoted to food crop production by 10%. In both climate scenarios, vegetation shifts further reduce the areas devoted to timber production by 6-8% over this same time period. Fire associated with climate-induced vegetation shifts causes the region to become more of a carbon source than if no vegetation shifts occur. Consideration of the interactions between climate-induced vegetation shifts and human activities through a modeling framework has provided clues to how humans may be able to adapt to a changing world and identified the tradeoffs, including unintended consequences, associated with proposed climate/energy policies.

  7. Temporal patterns of atmospheric mercury species in northern Mississippi during 2011-2012: influence of sudden population swings.

    PubMed

    Jiang, Yi; Cizdziel, James V; Lu, Duanjun

    2013-11-01

    Gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particulate bound mercury (PBM) were measured on the University of Mississippi campus from July 2011 to June 2012. It is believed to be the first time that concentrations of atmospheric mercury species have been documented in northern Mississippi, and at a location with relatively large and sudden swings in population. The mean concentration (±1 SD) of GEM was 1.54±0.32 ng m(-3); levels were lower and generally more stable during the winter (1.48±0.22) and spring (1.46±0.27) compared with the summer (1.56±0.32) and fall (1.63±0.42). Mean concentrations for GOM and PBM were 3.87 pg m(-3) and 4.58 pg m(-3), respectively; levels tended to be highest in the afternoon and lowest in the early morning hours. During the fall and spring academic semesters concentrations and variability of GOM and PBM both increased, possibly from vehicle exhaust. There were moderate negative correlations with wind speed (all species) and humidity (GOM and PBM). Backward air mass trajectory modeling for the ten highest peaks for each mercury species revealed that the majority of these events occurred from air masses that passed through the northern continental US region. Overall, this study illustrates the complexity of temporal fluctuations of airborne mercury species, even in a small town environment.

  8. Expression of Rhizobial Nitrogenase: Influence of Plant Cell-Conditioned Medium †

    PubMed Central

    Bednarski, Mary Ann; Reporter, Minocher

    1978-01-01

    Conditioned medium was obtained from suspension cultures of soybean (Glycine max L. Merrit) cells after incubating them for 4 to 8 days with rhizobia which were separated from the soybean cells by two dialysis bags, one within another. This conditioned medium from the plant cell side (PCM) of the two membranes was used to elicit and influence nitrogenase activity (acetylene reduction) in rhizobia. When conditions for obtaining PCM from the soybean cell suspension cultures were varied, it could be shown that freshly grown rhizobia were able to induce active compounds in the PCM. These compounds caused acetylene reduction activity in test rhizobia under conditions where control rhizobia, containing various substrates, showed little or no acetylene reduction activity. Rhizobia that were already capable of acetylene reduction could not induce such compounds in the PCM when this was included with test rhizobia. The PCM from soybean cultures was also found to aid the expression of nitrogenase activity in suspension cultures of rhizobia normally associated with either peas, lupins, broad beans, or clovers. This is the first communication indicating nitrogenase activity in freeliving cultures for various species of rhizobia. PMID:16345300

  9. High-power UV-LED degradation: Continuous and cycled working condition influence

    NASA Astrophysics Data System (ADS)

    Arques-Orobon, F. J.; Nuñez, N.; Vazquez, M.; Segura-Antunez, C.; González-Posadas, V.

    2015-09-01

    High-power (HP) UV-LEDs can replace UV lamps for real-time fluoro-sensing applications by allowing portable and autonomous systems. However, HP UV-LEDs are not a mature technology, and there are still open issues regarding their performance evolution over time. This paper presents a reliability study of 3 W UV-LEDs, with special focus on LED degradation for two working conditions: continuous and cycled (30 s ON and 30 s OFF). Accelerated life tests are developed to evaluate the influence of temperature and electrical working conditions in high-power LEDs degradation, being the predominant failure mechanism the degradation of the package. An analysis that includes dynamic thermal and optical HP UV-LED measurements has been performed. Static thermal and stress simulation analysis with the finite element method (FEM) identifies the causes of package degradation. Accelerated life test results prove that HP UV-LEDs working in cycled condition have a better performance than those working in continuous condition.

  10. Influence of storage conditions on the growth of Pseudomonas species in refrigerated raw milk.

    PubMed

    De Jonghe, Valerie; Coorevits, An; Van Hoorde, Koenraad; Messens, Winy; Van Landschoot, Anita; De Vos, Paul; Heyndrickx, Marc

    2011-01-01

    The refrigerated storage of raw milk throughout the dairy chain prior to heat treatment creates selective conditions for growth of psychrotolerant bacteria. These bacteria, mainly belonging to the genus Pseudomonas, are capable of producing thermoresistant extracellular proteases and lipases, which can cause spoilage and structural defects in pasteurized and ultra-high-temperature-treated milk (products). To map the influence of refrigerated storage on the growth of these pseudomonads, milk samples were taken after the first milking turn and incubated laboratory scale at temperatures simulating optimal and suboptimal preprocessing storage conditions. The outgrowth of Pseudomonas members was monitored over time by means of cultivation-independent denaturing gradient gel electrophoresis (DGGE). Isolates were identified by a polyphasic approach. These incubations revealed that outgrowth of Pseudomonas members occurred from the beginning of the dairy chain (farm tank) under both optimal and suboptimal storage conditions. An even greater risk for outgrowth, as indicated by a vast increase of about 2 log CFU per ml raw milk, existed downstream in the chain, especially when raw milk was stored under suboptimal conditions. This difference in Pseudomonas outgrowth between optimal and suboptimal storage was already statistically significant within the farm tank. The predominant taxa were identified as Pseudomonas gessardii, Pseudomonas gessardii-like, Pseudomonas fluorescens-like, Pseudomonas lundensis, Pseudomonas fragi, and Pseudomonas fragi-like. Those taxa show an important spoilage potential as determined on elective media for proteolysis and lipolysis. PMID:21115713

  11. Influence of growth conditions on exchange bias of NiMn-based spin valves

    SciTech Connect

    Wienecke, Anja; Kruppe, Rahel; Rissing, Lutz

    2015-05-07

    As shown in previous investigations, a correlation between a NiMn-based spin valve's thermal stability and its inherent exchange bias exists, even if the blocking temperature of the antiferromagnet is clearly above the heating temperature and the reason for thermal degradation is mainly diffusion and not the loss of exchange bias. Samples with high exchange bias are thermally more stable than samples with low exchange bias. Those structures promoting a high exchange bias are seemingly the same suppressing thermally induced diffusion processes (A. Wienecke and L. Rissing, “Relationship between thermal stability and layer-stack/structure of NiMn-based GMR systems,” in IEEE Transaction on Magnetic Conference (EMSA 2014)). Many investigations were carried out on the influence of the sputtering parameters as well as the layer thickness on the magnetoresistive effect. The influence of these parameters on the exchange bias and the sample's thermal stability, respectively, was hardly taken into account. The investigation described here concentrates on the last named issue. The focus lies on the influence of the sputtering parameters and layer thickness of the “starting layers” in the stack and the layers forming the (synthetic) antiferromagnet. This paper includes a guideline for the evaluated sputtering conditions and layer thicknesses to realize a high exchange bias and presumably good thermal stability for NiMn-based spin valves with a synthetic antiferromagnet.

  12. Influences of surface hydrophilicity on frost formation on a vertical cold plate under natural convection conditions

    SciTech Connect

    Liu, Zhongliang; Zhang, Xinghua; Wang, Hongyan; Meng, Sheng; Cheng, Shuiyuan

    2007-07-15

    Surface hydrophilicity has a strong influence on frost nucleation according to phase transition theory. To study this effect, a close observation of frost formation and deposition processes on a vertical plate was made under free convection conditions. The formation and shape variation of frost crystals during the initial period are described and the frost thickness variation with time on both hydrophobic and plain copper cold surfaces are presented. The various influencing factors are discussed in depth. The mechanism of surface hydrophilicity influence on frost formation was analyzed theoretically. This revealed that increasing the contact angle can increase the potential barrier and restrain crystal nucleation and growth and thus frost deposition. The experimental results show that the initial water drops formed on a hydrophobic surface are smaller and remain in the liquid state for a longer time compared with ones formed on a plain copper surface. It is also observed that the frost layer deposited on a hydrophobic surface is loose and weak. Though the hydrophobic surface can retard frost formation to a certain extent and causes a looser frost layer, our experimental results show that it does not depress the growth of the frost layer. (author)

  13. Influence of growth conditions on exchange bias of NiMn-based spin valves

    NASA Astrophysics Data System (ADS)

    Wienecke, Anja; Kruppe, Rahel; Rissing, Lutz

    2015-05-01

    As shown in previous investigations, a correlation between a NiMn-based spin valve's thermal stability and its inherent exchange bias exists, even if the blocking temperature of the antiferromagnet is clearly above the heating temperature and the reason for thermal degradation is mainly diffusion and not the loss of exchange bias. Samples with high exchange bias are thermally more stable than samples with low exchange bias. Those structures promoting a high exchange bias are seemingly the same suppressing thermally induced diffusion processes (A. Wienecke and L. Rissing, "Relationship between thermal stability and layer-stack/structure of NiMn-based GMR systems," in IEEE Transaction on Magnetic Conference (EMSA 2014)). Many investigations were carried out on the influence of the sputtering parameters as well as the layer thickness on the magnetoresistive effect. The influence of these parameters on the exchange bias and the sample's thermal stability, respectively, was hardly taken into account. The investigation described here concentrates on the last named issue. The focus lies on the influence of the sputtering parameters and layer thickness of the "starting layers" in the stack and the layers forming the (synthetic) antiferromagnet. This paper includes a guideline for the evaluated sputtering conditions and layer thicknesses to realize a high exchange bias and presumably good thermal stability for NiMn-based spin valves with a synthetic antiferromagnet.

  14. Conditional symbolic analysis detects nonlinear influences of respiration on cardiovascular control in humans

    PubMed Central

    Porta, Alberto; Marchi, Andrea; Bari, Vlasta; Heusser, Karsten; Tank, Jens; Jordan, Jens; Barbic, Franca; Furlan, Raffaello

    2015-01-01

    We propose a symbolic analysis framework for the quantitative characterization of complex dynamical systems. It allows the description of the time course of a single variable, the assessment of joint interactions and an analysis triggered by a conditioning input. The framework was applied to spontaneous variability of heart period (HP), systolic arterial pressure (SAP) and integrated muscle sympathetic nerve activity (MSNA) with the aim of characterizing cardiovascular control and nonlinear influences of respiration at rest in supine position, during orthostatic challenge induced by 80° head-up tilt (TILT) and about 3 min before evoked pre-syncope signs (PRESY). The approach detected (i) the exaggerated sympathetic modulation and vagal withdrawal from HP variability and the increased presence of fast MSNA variability components during PRESY compared with TILT; (ii) the increase of the SAP–HP coordination occurring at slow temporal scales and a decrease of that occurring at faster time scales during PRESY compared with TILT; (iii) the reduction of the coordination between fast MSNA and SAP patterns during TILT and PRESY; (iv) the nonlinear influences of respiration leading to an increased likelihood to observe the abovementioned findings during expiration compared with inspiration one. The framework provided simple, quantitative indexes able to distinguish experimental conditions characterized by different states of the autonomic nervous system and to detect the early signs of a life threatening situation such as postural syncope. PMID:25548269

  15. The influence of weather conditions on the relative incident rate of fishing vessels.

    PubMed

    Wu, Yue; Pelot, Ronald P; Hilliard, Casey

    2009-07-01

    There is a long history of studying the relationship between weather and maritime activities. This article analyzes the link between relative incident rate (RIR) and general weather factors within certain gridded areas and time periods. The study area, which encompasses a broad extent of Atlantic Canadian waters, includes fishing incidents recorded by the Canadian Coast Guard from 1997 to 1999. Methodologies used for traffic track generation in a geographical information system and aggregation of all relevant weather data needed for the statistical analyses are presented. Ultimately, a regression tree was built to illustrate the relationship between incident rate and the following six weather factors: wave height; sea surface temperature; air temperature; ice concentration; fog presence; and precipitation. Results from the regression tree reveal that the RIR defined as (incident number per area-day)/(traffic amount per area-day) across grid cells with incidents, increases as the weather conditions deteriorate in a general way, and the concentration of ice has the biggest influence on the magnitude of incident rates for a given level of traffic exposure. The results from this analysis may assist administrators of maritime traffic, especially those associated with fishing activities, through a better understanding of the influence on RIR of certain weather conditions within given areas in specific time periods.

  16. The influence of pitch dimensions on performance during small-sided and conditioned soccer games.

    PubMed

    Vilar, Luís; Duarte, Ricardo; Silva, Pedro; Chow, Jia Yi; Davids, Keith

    2014-01-01

    This study examined the influence of pitch dimensions in small-sided soccer games in shaping opportunities for performers to maintain ball possession, pass to teammates and shoot at goal. Fifteen amateur standard male participants (M = 21.87, σ = 1.96 years) played 5 v 5 small-sided soccer games in three varying pitch conditions (28 m × 14 m, 40 m × 20 m and 52 m × 26 m). Thirty sequences of play in each condition were selected for digitisation using TACTO software, allowing the capture of bi-dimensional displacement coordinate data of all players and the ball. The values of interpersonal distance between all attackers and immediate defenders and the relative distances of defenders to intercept a shot and a pass were computed as dependent variables. Results showed existence of fewer opportunities to maintain ball possession on smaller pitches, compared to medium and larger pitches. Conversely, the different dimensions set to the pitch did not influence opportunities for players to shoot at goal, or to perform passes to other teammates. By examining the specific spatial-temporal relationships of players and key-task constraints, the data from this study explain how effects of manipulating pitch dimensions of small-sided games might enhance opportunities for acquiring specific movement and decision-making skills. PMID:24915106

  17. The Influence of the Biological Pump on Marine Redox Conditions During Earth History

    NASA Astrophysics Data System (ADS)

    Meyer, K. M.; Ridgwell, A.; Payne, J.

    2015-12-01

    Evidence for bottom-water anoxia on the continental shelves waned over the course of the Phanerozoic, which may be influenced by secular changes in the biological pump that led to weaker positive feedbacks within the oceans. The biological pump describes the transfer of carbon from the atmosphere to the deep ocean, which creates vertical gradients in nutrients and oxygen, both important influences in the structure of marine ecosystems. We used the cGENIE Earth system model to quantitatively test the hypothesis that reductions in the efficiency of the nutrient recycling loop of the biological pump during the past 550 Ma reduced the extent of anoxia on the shelves and acted as an important control on marine animal ecosystems. When the modeled remineralization depth is shallow relative to the modern ocean, anoxia tends to be more widespread at continental shelf depths. As the modeled remineralization depth increases toward modern conditions, anoxia is less prevalent and occurs at depths below the continental shelves. Reduced marine productivity in the closed system configuration of cGENIE cannot produce the frequent bottom-water anoxia conditions envisioned for the Paleozoic. We hypothesize that evidence for greater animal abundance and metabolic demand during the Phanerozoic was driven by progressive oxygenation of shelf environments related to changes in the biological pump rather than greater food availability. In general, these model simulations suggest changes in the depth distribution of organic carbon remineralization may have controlled observed shifts in ocean chemistry, biogeochemical cycling, and ecosystem structure during the Phanerozoic.

  18. Conditional symbolic analysis detects nonlinear influences of respiration on cardiovascular control in humans.

    PubMed

    Porta, Alberto; Marchi, Andrea; Bari, Vlasta; Heusser, Karsten; Tank, Jens; Jordan, Jens; Barbic, Franca; Furlan, Raffaello

    2015-02-13

    We propose a symbolic analysis framework for the quantitative characterization of complex dynamical systems. It allows the description of the time course of a single variable, the assessment of joint interactions and an analysis triggered by a conditioning input. The framework was applied to spontaneous variability of heart period (HP), systolic arterial pressure (SAP) and integrated muscle sympathetic nerve activity (MSNA) with the aim of characterizing cardiovascular control and nonlinear influences of respiration at rest in supine position, during orthostatic challenge induced by 80° head-up tilt (TILT) and about 3 min before evoked pre-syncope signs (PRESY). The approach detected (i) the exaggerated sympathetic modulation and vagal withdrawal from HP variability and the increased presence of fast MSNA variability components during PRESY compared with TILT; (ii) the increase of the SAP-HP coordination occurring at slow temporal scales and a decrease of that occurring at faster time scales during PRESY compared with TILT; (iii) the reduction of the coordination between fast MSNA and SAP patterns during TILT and PRESY; (iv) the nonlinear influences of respiration leading to an increased likelihood to observe the abovementioned findings during expiration compared with inspiration one. The framework provided simple, quantitative indexes able to distinguish experimental conditions characterized by different states of the autonomic nervous system and to detect the early signs of a life threatening situation such as postural syncope. PMID:25548269

  19. Influence of beaver activity on summer growth and condition of age-2 Atlantic salmon parr

    USGS Publications Warehouse

    Sigourney, D.B.; Letcher, B.H.; Cunjak, R.A.

    2006-01-01

    The activity of beavers Castor canadensis in freshwater environments can have considerable localized impacts on the physical and biological components of riparian ecosystems. By changing the habitat of a stream, beaver dams can cause spatial variation in growth opportunity that may have direct consequences for the growth of resident fish. In a small stream in eastern Canada, we studied the effects of an ephemeral beaver pond on the growth and maturity of age-2 Atlantic salmon Salmo salar parr tagged with passive integrated transponder tags. Water temperature remained relatively uniform throughout the study site. We found very little movement of recaptured fish in the study site. Fish that were recaptured in the beaver pond displayed faster summer growth rates in both length and mass than fish that were recaptured immediately above or below the pond. We also found that parr in the pond maintained relatively high condition factors, whereas fish above and below the pond appeared to decrease in condition factor throughout the summer. In addition to growth, the maturation rates of age-2 males were higher above the dam than below. This study demonstrates the effect a beaver dam can have on individual growth rates. By influencing growth during sensitive periods, the beaver pond may also influence individual life history pathways. This information could be an important component in ecosystem models that predict the effect of beaver population dynamics on the growth of individual salmonids at the landscape scale. ?? Copyright by the American Fisheries Society 2006.

  20. Influence of introduced vs. native parasites on the body condition of migrant silver eels

    PubMed Central

    Gérard, Claudia; Trancart, Thomas; Amilhat, Elsa; Faliex, Elisabeth; Virag, Laure; Feunteun, Eric; Acou, Anthony

    2013-01-01

    Because parasitism is among the reasons invoked to explain the collapse of Anguilla anguilla, we evaluated the parasitic constraint on body condition (BC) of migrant silver eels as a proxy of fitness with inter-site comparisons. Metazoan parasites were studied in 149 silver eels from five sites (northern Europe). In total, 89% were infected by 13 species including Myxozoa, Monogenea, Cestoda, Nematoda, and Acanthocephala. Anguillicoloides crassus was most common (56%), then Acanthocephalus clavula (30%), and Pseudodactylogyrus sp. (17%). BC, calculated for 58 females, was negatively correlated by abundance of the introduced Pseudodactylogyrus sp. but not by other parasite taxa. Nevertheless, the introduced A. crassus was considered as a severe pathogen based on previous data, whereas the native A. clavula was supposed to have limited impact. Parasite component communities and BC were different between sites. Silver eels from Stockholm Archipelago (Sweden) were the least parasitized (40% vs. 90–95% for other sites) with no parasites on the gills. Burrishoole (Ireland) differed by the absence of A. crassus and high prevalence of A. clavula (84%) but without consequences on BC. Gudenaa (Denmark), Corrib (Ireland), and Frémur (France) were close due to high prevalence of A. crassus (89–93%). Gudenaa and Corrib were the most similar because Pseudodactylogyrus sp. was also highly prevalent (respectively 71% and 60%) whereas absent in Frémur. Our results suggest that the fitness loss induced by the introduced parasites could affect the spawning success of migrant silver eels from Gudenaa and Corrib, and to a lesser extent from Frémur, but probably not those from Stockholm Archipelago and Burrishoole. PMID:24135272

  1. Climatology of summer midtropospheric perturbations in the U.S. northern plains. Part I: Influence on northwest flow severe weather outbreaks

    SciTech Connect

    Wang, Shih-Yu; Chen, Tsing-Chang; Correia, James

    2011-02-13

    Northwest flow severe weather outbreaks (NWF outbreaks) describe a type of summer convective storm that occurs in areas of mid-level NWF in the central United States. Convective storms associated with NWF outbreaks are often progressive (i.e. traveling a long distance) along systematic, northwestsoutheast oriented tracks throughout the northern plains. Previous studies have observed that progressive convective storms under NWF are often coupled with subsynoptic-scale midtropospheric perturbations (MPs) coming from the Rocky Mountains. This study traces such MPs for the decade of 1997-2006 using the North American Regional Reanalysis to examine their climatology and possible influence on NWF outbreaks. MPs initiated over the Rocky Mountains have a maximum frequency in July when the North American anticyclone fully develops and forms prevailing NWF over the northern plains. MPs developed under this anticyclone appear restricted in their vertical extension. Nevertheless, persistent upward motion is apparent in the leading edge (east) of MPs soon after their genesis subsequently inducing or intensifying convective storms. MPs propagate along systematic tracks similar to those of NWF outbreaks. The propagation of MPs also synchronizes with the progressive behavior of the associated convective storms. When encountering strong low-level jets (LLJs), upward motion and convergence of water vapor flux associated with MPs intensify substantially, resulting in strongly enhanced convection and precipitation. Convective wind and hail frequencies associated with MPs in strong LLJs reveal a pattern and magnitude very similar to that of NWF outbreaks. While about 60% of summer rainfall in the northern plains is linked to MPs, 75% of these instances occur in strong LLJs.

  2. Influence of age on postural sway during different dual-task conditions

    PubMed Central

    Bergamin, Marco; Gobbo, Stefano; Zanotto, Tobia; Sieverdes, John C.; Alberton, Cristine L.; Zaccaria, Marco; Ermolao, Andrea

    2014-01-01

    Dual-task performance assessments of competing parallel tasks and postural outcomes are growing in importance for geriatricians, as it is associated with predicting fall risk in older adults. This study aims to evaluate the postural stability during different dual-task conditions including visual (SMBT), verbal (CBAT) and cognitive (MAT) tasks in comparison with the standard Romberg's open eyes position (OE). Furthermore, these conditions were investigated in a sample of young adults and a group of older healthy subjects to examine a potential interaction between type of secondary task and age status. To compare these groups across the four conditions, a within-between mixed model ANOVA was applied. Thus, a stabilometric platform has been used to measure center of pressure velocity (CoPV), sway area (SA), antero-posterior (AP) and medio-lateral (ML) oscillations as extents of postural sway. Tests of within-subjects effects indicated that different four conditions influenced the static balance for CoPV (p < 0.001), SA (p < 0.001). Post-hoc analyses indicated that CBAT task induced the worst balance condition on CoPV and resulted in significantly worse scores than OE (−11.4%; p < 0.05), SMBT (−17.8%; p < 0.01) and MAT (−17.8%; p < 0.01) conditions; the largest SA was found in OE, and it was statistically larger than SMBT (−27.0%; p < 0.01) and MAT (−23.1%; p < 0.01). The between-subjects analysis indicated a general lower balance control in the group of elderly subjects (CoPV p < 0.001, SA p < 0.002), while, the mixed model ANOVA did not detect any interaction effect between types of secondary task and groups in any parameters (CoPV p = 0.154, SA p = 0.125). Postural sway during dual-task assessments was also found to decrease with advancing age, however, no interactions between aging and types of secondary tasks were found. Overall, these results indicated that the secondary task which most influenced the length of sway path, as measured by postural

  3. Influence of age on postural sway during different dual-task conditions.

    PubMed

    Bergamin, Marco; Gobbo, Stefano; Zanotto, Tobia; Sieverdes, John C; Alberton, Cristine L; Zaccaria, Marco; Ermolao, Andrea

    2014-01-01

    Dual-task performance assessments of competing parallel tasks and postural outcomes are growing in importance for geriatricians, as it is associated with predicting fall risk in older adults. This study aims to evaluate the postural stability during different dual-task conditions including visual (SMBT), verbal (CBAT) and cognitive (MAT) tasks in comparison with the standard Romberg's open eyes position (OE). Furthermore, these conditions were investigated in a sample of young adults and a group of older healthy subjects to examine a potential interaction between type of secondary task and age status. To compare these groups across the four conditions, a within-between mixed model ANOVA was applied. Thus, a stabilometric platform has been used to measure center of pressure velocity (CoPV), sway area (SA), antero-posterior (AP) and medio-lateral (ML) oscillations as extents of postural sway. Tests of within-subjects effects indicated that different four conditions influenced the static balance for CoPV (p < 0.001), SA (p < 0.001). Post-hoc analyses indicated that CBAT task induced the worst balance condition on CoPV and resulted in significantly worse scores than OE (-11.4%; p < 0.05), SMBT (-17.8%; p < 0.01) and MAT (-17.8%; p < 0.01) conditions; the largest SA was found in OE, and it was statistically larger than SMBT (-27.0%; p < 0.01) and MAT (-23.1%; p < 0.01). The between-subjects analysis indicated a general lower balance control in the group of elderly subjects (CoPV p < 0.001, SA p < 0.002), while, the mixed model ANOVA did not detect any interaction effect between types of secondary task and groups in any parameters (CoPV p = 0.154, SA p = 0.125). Postural sway during dual-task assessments was also found to decrease with advancing age, however, no interactions between aging and types of secondary tasks were found. Overall, these results indicated that the secondary task which most influenced the length of sway path, as measured by postural stability was a

  4. Does dependency make a difference? The role of convenience, social influence, facilitating condition and self-efficacy on student's purchase behaviour of smartphone

    NASA Astrophysics Data System (ADS)

    Jaganathan, Mathivannan; Mustapa, Azrain Nasyrah; Hasan, Wan Azlina Wan; Mat, Nik Kamariah Nik; Alekam, Jamal Mohammed Esmail

    2014-12-01

    It is an undeniable fact that penetration level and usage and sales of Smartphone dramatically increased past few years, whereby; it has increased to almost 60 percent of total population. Despite the high penetration of smartphone, previous studies have exhibited inconsistent findings towards understanding the behavioural intention to use smartphone especially among university students. Thus, the purpose of this study is to examine purchasing behaviour of Smartphone among students. From the literature, five antecedents of purchasing behaviour were identified. Each variable is measured using 7-point Likert scale: convenience (10 items), social influence (6 items), self-efficacy (10 items), facilitating condition (11 items), dependency (14 items) and purchasing behaviour (4 items). Using the primary data collection method, 400 questionnaires were distributed to the target respondents of one of the public higher education in the northern region. The responses collected were 350 completed questionnaires representing 87.5 percent response rate. The data were analysed using Structural Equation Modeling (SEM) using AMOS. Confirmatory factor analysis of measurement models indicates adequate goodness or fit after few items were eliminated through modification indices verifications. Therefore, goodness of fit for the generated structural model shows the adequate fit. This study has established four direct significant causal effects and two significant mediating effects: (1) convenience and dependency, (2) social influence and dependency, (3) facilitating condition and purchase behaviour, (4), dependency and purchase behaviour. The significant mediating results are: (1). Dependency mediates the relationship between convenience and purchase behaviour; (2) dependency mediates social influence and purchase behaviour. Thus, findings suggested that convenience, social influence and dependency play a role in determining students purchase behaviour of smartphone. The researchers

  5. Comparisons of water quality during various streamflow conditions in five streams in northern New Jersey, 1982-97

    USGS Publications Warehouse

    Hunchak-Kariouk, Kathryn

    2002-01-01

    Relations between water-quality and flow characteristics and the relative importance of constant (point sources and ground-water discharge) and intermittent (nonpoint storm runoff) sources were determined for eight water-quality stations located on the Flat Brook and the Delaware, Musconetcong, Whippany, and Saddle Rivers. Water-quality and streamflow data were categorized on the basis of streamflow at the time of sample collection. Differences in concentrations and yields of selected water-quality constituents, including nutrients and bacteria, (1) among the stations during eight streamflow conditions and (2) at each station (a) between base flow and stormflow; (b) among before, during, and after a storm; and (c) among low, medium, and high flows were determined and related to the predominant type(s) of land development in the areas contributing drainage. At the station on the Delaware River, yields of fecal-coliform bacteria were affected more by contributions from storm runoff than by contributions from point sources and ground-water discharges; yields during a storm [7.0 x 108 (MPN/d)mi2 (most probable number per day per square mile)] were greater than yields during base flow (3.7 x 108 (MPN/d)mi2). Yields of nitrate plus nitrite, alkalinity, and chloride were affected more by contributions from point sources and ground-water discharges than by contributions from storm runoff; yields of these constituents were not significantly different during base flows and stormflows. At the Flat Brook and Whippany River stations, yields of most water-quality constituents were affected more by contributions from storm runoff than by contributions from point sources and ground-water discharge. For example, yields of nitrate plus nitrite were greater during stormflow (1.20 (lb/d)/mi2 (pounds per day per square mile) and 15.88 (lb/d)/mi2, respectively) than during base flow (0.26 (lb/d)/mi2 and 8.20 (lb/d)/mi2, respectively). At the Musconetcong River station, yields of total

  6. Influence of observers and stream flow on northern two-lined salamander (Eurycea bislineata bislineata) relative abundance estimates in Acadia and Shenandoah National Parks, USA

    USGS Publications Warehouse

    Crocker, J.B.; Bank, M.S.; Loftin, C.S.; Jung Brown, R.E.

    2007-01-01

    We investigated effects of observers and stream flow on Northern Two-Lined Salamander (Eurycea bislineata bislineata) counts in streams in Acadia (ANP) and Shenandoah National Parks (SNP). We counted salamanders in 22 ANP streams during high flow (May to June 2002) and during low flow (July 2002). We also counted salamanders in SNP in nine streams during high flow (summer 2003) and 11 streams during low flow (summers 2001?02, 2004). In 2002, we used a modified cover-controlled active search method with a first and second observer. In succession, observers turned over 100 rocks along five 1-m belt transects across the streambed. The difference between observers in total salamander counts was not significant. We counted fewer E. b. bislineata during high flow conditions, confirming that detection of this species is reduced during high flow periods and that assessment of stream salamander relative abundance is likely more reliable during low or base flow conditions.

  7. Influence of thinning of Douglas-fir forests on population parameters and diet of northern flying squirrels

    USGS Publications Warehouse

    Gomez, D.M.; Anthony, R.G.; Hayes, J.P.

    2005-01-01

    We investigated the effects of thinning young (35- to 45-yr-old) Douglas-fir (Pseudotsuga menziesii) forests on density, survival, body mass, movements, and diets of northern flying squirrels (Glaucomys sabrinus) in the northern coast range of Oregon. We used a repeated measures, randomized block design with 3 treatments (control, moderate thinning, and heavy thinning) and 4 replicates to study diets and population characteristics from 1994-1997. Densities of flying squirrels were variable in space and time, but they were positively correlated to biomass and frequency of fungal sporocarps, suggesting they were responding to food resources rather than forest structure. Fungal sporocarps comprised a major portion of the squirrel's diet, and other vegetative material made up the remainder of the diet. Several fungal genera including Gautieria, Geopora, Hymenogaster, Hysterangium, Melanogaster, and Rhizopogon were found more frequently in diets than on the trapping grids and therefore appeared to be selected by the squirrels. Flying squirrel movements were negatively correlated with the frequency of occurrence of fungal sporocarps at trap stations, suggesting that squirrels traveled greater distances to find fungal sporocarps where these food items were more sparsely distributed. We hypothesized that flying squirrel densities would be relatively low in these young, structurally simple forests; however, densities on some of the grids were >1.5 squirrels/ha, which was comparable to densities described for the species in late-successional forests. Our results indicated that commercial thinning did not have measurable short-term effects on density, survival, or body mass of flying squirrels.

  8. Contrasting landscape influences on sediment supply and stream restoration priorities in northern Fennoscandia (Sweden and Finland) and coastal British Columbia.

    PubMed

    Rosenfeld, Jordan; Hogan, Daniel; Palm, Daniel; Lundquist, Hans; Nilsson, Christer; Beechie, Timothy J

    2011-01-01

    Sediment size and supply exert a dominant control on channel structure. We review the role of sediment supply in channel structure, and how regional differences in sediment supply and land use affect stream restoration priorities. We show how stream restoration goals are best understood within a common fluvial geomorphology framework defined by sediment supply, storage, and transport. Land-use impacts in geologically young landscapes with high sediment yields (e.g., coastal British Columbia) typically result in loss of in-stream wood and accelerated sediment inputs from bank erosion, logging roads, hillslopes and gullies. In contrast, northern Sweden and Finland are landscapes with naturally low sediment yields caused by low relief, resistant bedrock, and abundant mainstem lakes that act as sediment traps. Land-use impacts involved extensive channel narrowing, removal of obstructions, and bank armouring with boulders to facilitate timber floating, thereby reducing sediment supply from bank erosion while increasing export through higher channel velocities. These contrasting land-use impacts have pushed stream channels in opposite directions (aggradation versus degradation) within a phase-space defined by sediment transport and supply. Restoration in coastal British Columbia has focused on reducing sediment supply (through bank and hillslope stabilization) and restoring wood inputs. In contrast, restoration in northern Fennoscandia (Sweden and Finland) has focused on channel widening and removal of bank-armouring boulders to increase sediment supply and retention. These contrasting restoration priorities illustrate the consequences of divergent regional land-use impacts on sediment supply, and the utility of planning restoration activities within a mechanistic sediment supply-transport framework. PMID:21132293

  9. Contrasting landscape influences on sediment supply and stream restoration priorities in northern Fennoscandia (Sweden and Finland) and coastal British Columbia.

    PubMed

    Rosenfeld, Jordan; Hogan, Daniel; Palm, Daniel; Lundquist, Hans; Nilsson, Christer; Beechie, Timothy J

    2011-01-01

    Sediment size and supply exert a dominant control on channel structure. We review the role of sediment supply in channel structure, and how regional differences in sediment supply and land use affect stream restoration priorities. We show how stream restoration goals are best understood within a common fluvial geomorphology framework defined by sediment supply, storage, and transport. Land-use impacts in geologically young landscapes with high sediment yields (e.g., coastal British Columbia) typically result in loss of in-stream wood and accelerated sediment inputs from bank erosion, logging roads, hillslopes and gullies. In contrast, northern Sweden and Finland are landscapes with naturally low sediment yields caused by low relief, resistant bedrock, and abundant mainstem lakes that act as sediment traps. Land-use impacts involved extensive channel narrowing, removal of obstructions, and bank armouring with boulders to facilitate timber floating, thereby reducing sediment supply from bank erosion while increasing export through higher channel velocities. These contrasting land-use impacts have pushed stream channels in opposite directions (aggradation versus degradation) within a phase-space defined by sediment transport and supply. Restoration in coastal British Columbia has focused on reducing sediment supply (through bank and hillslope stabilization) and restoring wood inputs. In contrast, restoration in northern Fennoscandia (Sweden and Finland) has focused on channel widening and removal of bank-armouring boulders to increase sediment supply and retention. These contrasting restoration priorities illustrate the consequences of divergent regional land-use impacts on sediment supply, and the utility of planning restoration activities within a mechanistic sediment supply-transport framework.

  10. Carryover effects and climatic conditions influence the postfledging survival of greater sage-grouse

    PubMed Central

    Blomberg, Erik J; Sedinger, James S; Gibson, Daniel; Coates, Peter S; Casazza, Michael L

    2014-01-01

    Prebreeding survival is an important life history component that affects both parental fitness and population persistence. In birds, prebreeding can be separated into pre- and postfledging periods; carryover effects from the prefledging period may influence postfledging survival. We investigated effects of body condition at fledging, and climatic variation, on postfledging survival of radio-marked greater sage-grouse (Centrocercus urophasianus) in the Great Basin Desert of the western United States. We hypothesized that body condition would influence postfledging survival as a carryover effect from the prefledging period, and we predicted that climatic variation may mediate this carryover effect or, alternatively, would act directly on survival during the postfledging period. Individual body condition had a strong positive effect on postfledging survival of juvenile females, suggesting carryover effects from the prefledging period. Females in the upper 25th percentile of body condition scores had a postfledging survival probability more than twice that (Φ = 0.51 ± 0.06 SE) of females in the bottom 25th percentile (Φ = 0.21 ± 0.05 SE). A similar effect could not be detected for males. We also found evidence for temperature and precipitation effects on monthly survival rates of both sexes. After controlling for site-level variation, postfledging survival was nearly twice as great following the coolest and wettest growing season (Φ = 0.77 ± 0.05 SE) compared with the hottest and driest growing season (Φ = 0.39 ± 0.05 SE). We found no relationships between individual body condition and temperature or precipitation, suggesting that carryover effects operated independently of background climatic variation. The temperature and precipitation effects we observed likely produced a direct effect on mortality risk during the postfledging period. Conservation actions that focus on improving prefledging habitat for sage-grouse may have indirect benefits

  11. Carryover effects and climatic conditions influence the postfledging survival of greater sage-grouse

    USGS Publications Warehouse

    Blomberg, Erik J.; Sedinger, James S.; Gibson, Daniel; Coates, Peter S.; Casazza, Michael L.

    2014-01-01

    Prebreeding survival is an important life history component that affects both parental fitness and population persistence. In birds, prebreeding can be separated into pre- and postfledging periods; carryover effects from the prefledging period may influence postfledging survival. We investigated effects of body condition at fledging, and climatic variation, on postfledging survival of radio-marked greater sage-grouse (Centrocercus urophasianus) in the Great Basin Desert of the western United States. We hypothesized that body condition would influence postfledging survival as a carryover effect from the prefledging period, and we predicted that climatic variation may mediate this carryover effect or, alternatively, would act directly on survival during the postfledging period. Individual body condition had a strong positive effect on postfledging survival of juvenile females, suggesting carryover effects from the prefledging period. Females in the upper 25th percentile of body condition scores had a postfledging survival probability more than twice that (Φ = 0.51 ± 0.06 SE) of females in the bottom 25th percentile (Φ = 0.21 ± 0.05 SE). A similar effect could not be detected for males. We also found evidence for temperature and precipitation effects on monthly survival rates of both sexes. After controlling for site-level variation, postfledging survival was nearly twice as great following the coolest and wettest growing season (Φ = 0.77 ± 0.05 SE) compared with the hottest and driest growing season (Φ = 0.39 ± 0.05 SE). We found no relationships between individual body condition and temperature or precipitation, suggesting that carryover effects operated independently of background climatic variation. The temperature and precipitation effects we observed likely produced a direct effect on mortality risk during the postfledging period. Conservation actions that focus on improving prefledging habitat for sage-grouse may have indirect benefits

  12. Carryover effects and climatic conditions influence the postfledging survival of greater sage-grouse.

    PubMed

    Blomberg, Erik J; Sedinger, James S; Gibson, Daniel; Coates, Peter S; Casazza, Michael L

    2014-12-01

    Prebreeding survival is an important life history component that affects both parental fitness and population persistence. In birds, prebreeding can be separated into pre- and postfledging periods; carryover effects from the prefledging period may influence postfledging survival. We investigated effects of body condition at fledging, and climatic variation, on postfledging survival of radio-marked greater sage-grouse (Centrocercus urophasianus) in the Great Basin Desert of the western United States. We hypothesized that body condition would influence postfledging survival as a carryover effect from the prefledging period, and we predicted that climatic variation may mediate this carryover effect or, alternatively, would act directly on survival during the postfledging period. Individual body condition had a strong positive effect on postfledging survival of juvenile females, suggesting carryover effects from the prefledging period. Females in the upper 25th percentile of body condition scores had a postfledging survival probability more than twice that (Φ = 0.51 ± 0.06 SE) of females in the bottom 25th percentile (Φ = 0.21 ± 0.05 SE). A similar effect could not be detected for males. We also found evidence for temperature and precipitation effects on monthly survival rates of both sexes. After controlling for site-level variation, postfledging survival was nearly twice as great following the coolest and wettest growing season (Φ = 0.77 ± 0.05 SE) compared with the hottest and driest growing season (Φ = 0.39 ± 0.05 SE). We found no relationships between individual body condition and temperature or precipitation, suggesting that carryover effects operated independently of background climatic variation. The temperature and precipitation effects we observed likely produced a direct effect on mortality risk during the postfledging period. Conservation actions that focus on improving prefledging habitat for sage-grouse may have indirect benefits

  13. Statistical approach for assessing the influence of synoptic and meteorological conditions on ozone concentrations over Europe

    NASA Astrophysics Data System (ADS)

    Otero, Noelia; Butler, Tim; Sillmann, Jana

    2015-04-01

    Air pollution has become a serious problem in many industrialized and densely-populated urban areas due to its negative effects on human health, damages agricultural crops and ecosystems. The concentration of air pollutants is the result of several factors, including emission sources, lifetime and spatial distribution of the pollutants, atmospheric properties and interactions, wind speed and direction, and topographic features. Episodes of air pollution are often associated with stationary or slowly migrating anticyclonic (high-pressure) systems that reduce advection, diffusion, and deposition of atmospheric pollutants. Certain weather conditions facilitate the concentration of pollutants, such as the incidence of light winds that contributes to the increasing of stagnation episodes affecting air quality. Therefore, the atmospheric circulation plays an important role in air quality conditions that are affected by both, synoptic and local scale processes. This study assesses the influence of the large-scale circulation along with meteorological conditions on tropospheric ozone in Europe. The frequency of weather types (WTs) is examined under a novel approach, which is based on an automated version of the Lamb Weather Types catalog (Jenkinson and Collison, 1977). Here, we present an implementation of such classification point-by-point over the European domain. Moreover, the analysis uses a new grid-averaged climatology (1°x1°) of daily surface ozone concentrations from observations of individual sites that matches the resolution of global models (Schnell,et al., 2014). Daily frequency of WTs and meteorological conditions are combined in a multiple regression approach for investigating the influence on ozone concentrations. Different subsets of predictors are examined within multiple linear regression models (MLRs) for each grid cell in order to identify the best regression model. Several statistical metrics are applied for estimating the robustness of the

  14. The influence of variations in biophysical conditions on hemolysis near ultrasonically activated gas-filled micropores

    SciTech Connect

    Miller, D.L.; Thomas, R.M. )

    1990-05-01

    Hemolysis induced by 1.9-MHz ultrasound in 0.5% suspensions of canine erythrocytes with 3.7-{mu}m-diam micropore-trapped gas bodies was investigated for a variety of biophysical conditions. For isotonic media, hemolysis increased with exposure duration but did not greatly change with exposure temperature, or prior heat treatment. The temperature results were especially interesting because increased temperatures might have been expected to increase the sensitivity of the cells to the ultrasonically activated gas bodies. Variations in osmolarity had little influence on the results. Increasing the viscosity of the medium decreased the effect, and this did not seem to depend on the molecular weight of the dextran additive. A medium with elevated mass density seemed to increase the effectiveness of the exposures. This condition eliminated the density difference between the cells and the medium, and might have been expected to reduce the effectiveness of the exposures, because the radiation force, which theoretically gathers cells to the gas bodies, is minimized for such conditions. This information should aid in developing refinements to the theoretical understanding of low-intensity ultrasonic bioeffects.

  15. The influence of rearing conditions on the physical growth of captive Japanese macaques (Macaca fuscata).

    PubMed

    Suzuki, J; Miwa, N; Kumazaki, K; Abe, M; Kamanaka, Y; Matsubayashi, N; Gotoh, S; Matsubayashi, K

    2001-04-01

    To clarify the influence of rearing conditions on the growth of various body parts of Japanese macaques (Macaca fuscata), two groups reared under different conditions, i.e., a group born and reared in open enclosures (Enclosure group) and another consisting of macaques born and reared in cages (Caged group), were somatometrically analyzed. Somatometric data on 36 measures of various body parts were collected from 77 males and 92 females. Growth in many body parts was smaller in the Caged group than in the Enclosure group. Body parts that exhibited large incremental increases were more sensitive to differences in rearing space at the infantile growth stage in both sexes. Recovery from delayed growth at the pubertal growth stage was found in many body parts. However, the size of some locomotor elements such as the wrist and hand, and ankle and foot strongly reflected limitations of space and changes due to this were irreversible. Females were more sensitive than males to such differences in rearing conditions. We conclude that open enclosures with ample rearing space are necessary for the innate growth of Japanese macaques to occur.

  16. Rain influences the physiological and metabolic responses to exercise in hot conditions.

    PubMed

    Ito, Ryo; Yamashita, Naoyuki; Suzuki, Eiko; Matsumoto, Takaaki

    2015-01-01

    Outdoor exercise often proceeds in rainy conditions. However, the cooling effects of rain on human physiological responses have not been systematically studied in hot conditions. The present study determined physiological and metabolic responses using a climatic chamber that can precisely simulate hot, rainy conditions. Eleven healthy men ran on a treadmill at an intensity of 70% VO2max for 30 min in the climatic chamber at an ambient temperature of 33°C in the presence (RAIN) or absence (CON) of 30 mm · h(-1) of precipitation and a headwind equal to the running velocity of 3.15 ± 0.19 m · s(-1). Oesophageal temperature, mean skin temperature, heart rate, rating of perceived exertion, blood parameters, volume of expired air and sweat loss were measured. Oesophageal and mean skin temperatures were significantly lower from 5 to 30 min, and heart rate was significantly lower from 20 to 30 min in RAIN than in CON (P < 0.05 for all). Plasma lactate and epinephrine concentrations (30 min) and sweat loss were significantly lower (P < 0.05) in RAIN compared with CON. Rain appears to influence physiological and metabolic responses to exercise in heat such that heat-induced strain might be reduced.

  17. Influence of temperature and relative humidity conditions on the pan coating of hydroxypropyl cellulose molded capsules.

    PubMed

    Macchi, Elena; Zema, Lucia; Pandey, Preetanshu; Gazzaniga, Andrea; Felton, Linda A

    2016-03-01

    In a previous study, hydroxypropyl cellulose (HPC)-based capsular shells prepared by injection molding and intended for pulsatile release were successfully coated with 10mg/cm(2) Eudragit® L film. The suitability of HPC capsules for the development of a colon delivery platform based on a time dependent approach was demonstrated. In the present work, data logging devices (PyroButton®) were used to monitor the microenvironmental conditions, i.e. temperature (T) and relative humidity (RH), during coating processes performed under different spray rates (1.2, 2.5 and 5.5g/min). As HPC-based capsules present special features, a preliminary study was conducted on commercially available gelatin capsules for comparison purposes. By means of PyroButton data-loggers it was possible to acquire information about the impact of the effective T and RH conditions experienced by HPC substrates during the process on the technological properties and release performance of the coated systems. The use of increasing spray rates seemed to promote a tendency of the HPC shells to slightly swell at the beginning of the spraying process; moreover, capsules coated under spray rates of 1.2 and 2.5g/min showed the desired release performance, i.e. ability to withstand the acidic media followed by the pulsatile release expected for uncoated capsules. Preliminary stability studies seemed to show that coating conditions might also influence the release performance of the system upon storage. PMID:26686650

  18. Rain influences the physiological and metabolic responses to exercise in hot conditions.

    PubMed

    Ito, Ryo; Yamashita, Naoyuki; Suzuki, Eiko; Matsumoto, Takaaki

    2015-01-01

    Outdoor exercise often proceeds in rainy conditions. However, the cooling effects of rain on human physiological responses have not been systematically studied in hot conditions. The present study determined physiological and metabolic responses using a climatic chamber that can precisely simulate hot, rainy conditions. Eleven healthy men ran on a treadmill at an intensity of 70% VO2max for 30 min in the climatic chamber at an ambient temperature of 33°C in the presence (RAIN) or absence (CON) of 30 mm · h(-1) of precipitation and a headwind equal to the running velocity of 3.15 ± 0.19 m · s(-1). Oesophageal temperature, mean skin temperature, heart rate, rating of perceived exertion, blood parameters, volume of expired air and sweat loss were measured. Oesophageal and mean skin temperatures were significantly lower from 5 to 30 min, and heart rate was significantly lower from 20 to 30 min in RAIN than in CON (P < 0.05 for all). Plasma lactate and epinephrine concentrations (30 min) and sweat loss were significantly lower (P < 0.05) in RAIN compared with CON. Rain appears to influence physiological and metabolic responses to exercise in heat such that heat-induced strain might be reduced. PMID:25555077

  19. Influence of season on the hematological and serum biochemical values of bottlenose dolphins (Tursiops truncatus) housed in a controlled environment in northern Italy.

    PubMed

    Macchi, Elisabetta; Pezzoli, Lorenzo; Ponzio, Patrizia

    2011-09-01

    Season appears to influence the physiology of bottlenose dolphins (Tursiops truncatus). From 2000 to 2005, blood parameters of three captive bottlenose dolphins housed in northern Italy were examined to determine if seasonal variation was present. Seasonal variation was observed in the male dolphins, with both males exhibiting aminotransferase levels that were higher in autumn and lower in winter. Mean serum creatinine levels were higher during summer and lower during autumn in the adult male, and mean lactate dehydrogenase higher during summer and lower during spring in the juvenile male. Both males exhibited red blood cell counts and hemoglobin levels that were higher during autumn and lower during summer. This study contributes to the knowledge of baseline hematologic and biochemical values based on seasonality in bottlenose dolphins. PMID:22950322

  20. The Association of Arsenic With Redox Conditions, Depth, and Ground-Water Age in the Glacial Aquifer System of the Northern United States

    USGS Publications Warehouse

    Thomas, Mary Ann

    2007-01-01

    More than 800 wells in the glacial aquifer system of the Northern United States were sampled for arsenic as part of U.S. Geological Survey National Water-Quality Assessment (NAWQA) studies during 1991-2003. Elevated arsenic concentrations (greater than or equal to 10 micrograms per liter) were detected in 9 percent of samples. Elevated arsenic concentrations were associated with strongly reducing conditions. Of the samples classified as iron reducing or sulfate reducing, arsenic concentrations were elevated in 19 percent. Of the methanogenic samples, arsenic concentrations were elevated in 45 percent. In contrast, concentrations of arsenic were elevated in only 1 percent of oxic samples. Arsenic concentrations were also related to ground-water age. Elevated arsenic concentrations were detected in 34 percent of old waters (recharged before 1953) as compared to 4 percent of young waters (recharged since 1953). For samples classified as both old and methanogenic, elevated arsenic concentrations were detected in 62 percent of samples, as compared to 1 percent for samples classified as young and oxic. Arsenic concentrations were also correlated with well depth and concentrations of several chemical constituents, including (1) constituents linked to redox processes and (2) anions or oxyanions that sorb to iron oxides. Observations from the glacial aquifer system are consistent with the idea that the predominant source of arsenic is iron oxides and the predominant mechanism for releasing arsenic to the ground water is reductive desorption or reductive dissolution. Arsenic is also released from iron oxides under oxic conditions, but on a more limited basis and at lower concentrations. Logistic regression was used to investigate the relative significance of redox, ground-water age, depth, and other water-quality constituents as indicators of elevated arsenic concentrations in the glacial aquifer system. The single variable that explained the greatest amount of variation in

  1. Influence of environmental conditions on early development of the hydrothermal vent polychaete Alvinella pompejana.

    PubMed

    Pradillon, Florence; Le Bris, Nadine; Shillito, Bruce; Young, Craig M; Gaill, Françoise

    2005-04-01

    Dispersal and colonisation processes at deep-sea vents are still not fully understood, essentially because early life stages of vent species remain unknown. The polychaete worm Alvinella pompejana forms colonies on chimney walls at East Pacific Rise vent sites where the temperature can frequently exceed 20 degrees C. In vitro studies in pressure vessels showed that the early embryos tolerate temperatures in a lower range (10-14 degrees C), suggesting that they would have to escape the colony to develop. Pressure vessels offer the advantage that each parameter can be independently controlled, but they do not simulate the more complex and dynamic conditions naturally encountered at vent sites. Accordingly, in addition to incubations in pressure vessels, we incubated embryos directly at a vent site, in different habitats along a gradient of hydrothermal influence. Embryos incubated on an adult A. pompejana colony where temperature and H(2)S concentrations were relatively high showed a very low survival rate and did not develop, whereas embryos incubated in a Riftia pachyptila clump environment with a lower hydrothermal signature, or at the base of the chimney where the influence of the hydrothermal activity was very weak, survived well and developed. Although the average temperature recorded in the A. pompejana colony was within the range tolerated by embryos (13 degrees C), frequent peaks above 20 degrees C were recorded. Estimated sulphide concentration at this site reached 200 mumol l(-1). Punctuated exposure to both high temperature and elevated sulphide levels probably explain the low survival of embryos within the A. pompejana colony. The in situ experiments further support the idea that embryos require conditions with moderate hydrothermal influence not generally found within an adult colony. However, as much more benign physicochemical conditions can be found within a few tens of cm of adult colonies, embryos do not necessarily have to leave their vent of

  2. [Examination of physical and psychological health conditions and the influence factors of home helpers].

    PubMed

    Ashitomi, Ikuya

    2005-12-01

    The primary aim of this study was to examine the physical and psychological health conditions and the influence factors of home helpers. The secondary aim was to suggest a stress management system for home helpers. Self-report questionnaires were distributed to 1147 home helpers who were with home health care agencies in Kitakyushu-city. Responses from 979 home helpers were received, yielding a response rate of 85.5%. A total of 967 home helpers (excluding 12 male home helpers) were used for analysis. The Japanese version of the General Health Questionnaire 28 (GHQ-28) was used to measure the physical and psychological health conditions of the home helpers. In addition, as an influence factor, stress coping was measured by the Lazarus-type Stress Coping Inventory (SCI). Home helpers also filled out the Ego Aptitude Scale (EAS) as a personality measure. Furthermore, the subjects were asked questions about individual background factors, including age, marital status, working hours, years working as a home helper, type of home helper, job satisfaction, job continuation and awareness of stress. The data were analyzed using the Statistical Package for the Social Sciences (SPSS 11.5 J). The groups of full-time or part-time home helpers showed GHQ-28 total scores of 6.86 +/- 5.48 and 5.21 +/- 4.97 (Mean +/- SD): part-time home helpers had significantly higher scores than full-time home helpers. The GHQ-28 measure indicated that about 20% of home helpers had physical and psychological symptoms, and about 4% had mid-level depressive symptoms. About half of the subjects were aware of stress. There were significant negative correlations between GHQ-28 total scores and age. Also, there was a statistically significant relation between GHQ-28 and job satisfaction, awareness of stress, type of stress coping and individual personality. Furthermore, there was a statistically significant relation between GHQ-28 and the confrontive coping type, positive reappraisal of SCI, and

  3. Larval history influences post-metamorphic condition in a coral-reef fish.

    PubMed

    Hamilton, Scott L

    2008-12-01

    Upon settlement, many fishes undergo an energetically costly metamorphic period that requires substantial nutritional reserves. Larval growth and the accumulation of lipids prior to metamorphosis are likely to influence growth and survival following this critical period. On the Caribbean island of St. Croix, I investigated relationships between larval growth, early life-history characteristics, and post-metamorphic lipid content in the bluehead wrasse Thalassoma bifasciatum. Lipid reserves remaining after metamorphosis were positively related (r2 = 0.62) to the width of the metamorphic band; thus, this otolith-derived trait may be used to estimate the condition at emergence of survivors collected at some later time. In contrast, pelagic larval duration, average larval growth, and otolith size at settlement were negatively related to post-metamorphic lipid content. Interestingly, the trend for slower growth among fish in good condition was not consistent over the entire pelagic larval duration. Analyses of daily larval growth histories indicated that fish with high lipid reserves grew rapidly in the last week prior to settlement, but relatively slowly during the early phases of larval life; those emerging with low lipid concentrations, however, displayed strikingly opposite patterns. These contrasting patterns of growth and energy storage were consistent at two sites and over three recruitment events. Otolith chemistry data suggested that differences in growth histories and body condition were consistent with the hypothesis of larval development in distinct oceanic environments (characterized by Pb concentration); but, within a water mass, differences reflected life-history trade-offs between growth and energy storage. The results have implications for understanding the processes driving juvenile survival, which may be condition dependent.

  4. Influence of support conditions on vertical whole-body vibration of the seated human body.

    PubMed

    M-Pranesh, Anand; Rakheja, Subhash; Demont, Richard

    2010-01-01

    The vibration transmission to the lumbar and thoracic segments of seated human subjects exposed to whole body vibration of a vehicular nature have been mostly characterised without the back and hand supports, which is not representative of general driving conditions. This non-invasive experimental study investigated the transmission of vertical seat vibration to selected vertebrae and the head along the vertical and fore-aft axes of twelve male human subjects seated on a rigid seat and exposed to random vertical excitation in the 0.5-20 Hz range. The measurements were performed under four different sitting postures involving combinations of back support conditions and hands positions, and three difference magnitudes of vertical vibration (0.25, 0.5 and 1.0 m/s(2) rms acceleration). The results showed significant errors induced by sensor misalignment and skin effects, which required appropriate correction methodologies. The averaged corrected responses revealed that the back support attenuates vibration in the vertical axis to all the body locations while increasing the fore-aft transmissibility at the C7 and T5. The hands position generally has a relatively smaller effect, showing some influences on the C7 and L5 vibration. Sitting without a back support resulted in very low magnitude fore-aft vibration at T5, which was substantially higher with a back support, suggestive of a probable change in the body's vibration mode. The effect of back support was observed to be very small on the horizontal vibration of the lower thoracic and lumbar regions. The results suggest that distinctly different target body-segment biodynamic functions need to be defined for different support conditions in order to represent the unique contribution of the specific support condition. These datasets may then be useful for the development of biodynamic models.

  5. Relative Influence of Initial Surface and Atmospheric Conditions on Seasonal Water and Energy Balances

    NASA Technical Reports Server (NTRS)

    Oglesby, Robert J.; Marshall, Susan; Roads, John O.; Robertson, Franklin R.; Goodman, H. Michael (Technical Monitor)

    2001-01-01

    We constructed and analyzed wet and dry soil moisture composites for the mid-latitude GCIP region of the central US using long climate model simulations made with the NCAR CCM3 and reanalysis products from NCEP. Using the diagnostic composites as a guide, we have completed a series of predictability experiments in which we imposed soil water initial conditions in CCM3 for the GCIP region for June 1 from anomalously wet and dry years, with atmospheric initial conditions taken from June 1 of a year with 'near-normal' soil water, and initial soil water from the near-normal year and atmospheric initial conditions from the wet and dry years. Preliminary results indicate that the initial state of the atmosphere is more important than the initial state of soil water determining the subsequent late spring and summer evolution of sod water over the GCIP region. Surprisingly, neither the composites or the predictability experiments yielded a strong influence of soil moisture on the atmosphere. To explore this further, we have made runs with extreme dry soil moisture initial anomalies imposed over the GCIP region (the soil close to being completely dry). These runs did yield a very strong effect on the atmosphere that persisted for at least three months. We conclude that the magnitude of the initial soil moisture anomaly is crucial, at least in CCM3, and are currently investigating whether a threshold exists, below which little impact is seen. In a complementary study, we compared the impact of the initial condition of snow cover versus the initial atmospheric state over the western US (corresponding to the westward extension of the GAPP program follow-on to GCIP). In this case, the initial prescription of snow cover is far more important than the initial atmospheric state in determining the subsequent evolution of snow cover. We are currently working to understand the very different soil water and snow cover results.

  6. Estimating the influence of vegetation on net infiltration under future climatic conditions

    NASA Astrophysics Data System (ADS)

    Stothoff, S. A.

    2005-12-01

    Performance assessments of the proposed geologic repository at Yucca Mountain, Nevada, are sensitive to the net infiltration passing the root zone above the repository, an area of roughly 5 km2. The area of interest has a semiarid climate, ten washes in rugged topography, and shallow soils overlying fractured bedrock composed of silicic volcanic tuff. Mean annual net infiltration is uncertain but constrained under current climatic conditions, based on modeling and observations. Performance assessments that consider periods of one or more glacial cycles must address net infiltration under wetter and cooler future climatic conditions. Potential evapotranspiration under current climatic conditions is sufficiently large relative to mean annual precipitation that numerical simulators are relatively insensitive to how evapotranspiration is implemented in the model. Water passes from soil into the bedrock only over short periods while the soil is wet following large storms. Under wetter and cooler climatic conditions, the representation of evapotranspiration may be more important, particularly the component handling plant uptake. Plant uptake models from the crop science literature assume that the plants have a predictable growth pattern over a growing season and predictable rooting patterns. These assumptions, reasonable for agricultural situations with annual crops in deep soil, may be questionable or difficult to parameterize when considering uptake from long-lived shrubs in semiarid climates with shallow soils and strong interannual variation in rainfall. An adaptive vegetation model is proposed that allows vegetation to respond to environmental influences. The adaptive model allocates roots according to uptake, which is mediated by the environment, within limits set by genetic preferences. The model allows growth in wet periods and dieback in dry periods, and allocates roots within the bedrock fractures to the depth supported by moisture availability. Estimated mean

  7. Pre-slaughter conditions influence skatole and androstenone in adipose tissue of boars.

    PubMed

    Wesoly, Raffael; Jungbluth, Ina; Stefanski, Volker; Weiler, Ulrike

    2015-01-01

    Boar taint in carcasses may vary between farms and abattoirs, although the underlying mechanisms are not yet fully understood. In the present study, 169 boars from three farms were split into two groups and slaughtered at two abattoirs. Duration of transport and the time between arrival at the abattoir and unloading (pre-unloading time) were recorded. During slaughter, blood, feces, and urine were collected to measure testosterone and cortisol levels. Carcasses were classified according to the number of skin lesions, and fat samples were taken to determine skatole, indole and androstenone levels. Androstenone in fat and testosterone in blood, feces, and urine were mainly influenced by the duration of transport. Skatole and indole concentrations were increased by both pre-unloading time and duration of transport, but were also related to skin lesions. Thus it is concluded that androstenone and skatole concentrations in fat are significantly modified by pre-slaughter conditions.

  8. Influence of thermal boundary conditions on the current-driven resistive transition in VO2 microbridges

    NASA Astrophysics Data System (ADS)

    Manca, Nicola; Kanki, Teruo; Tanaka, Hidekazu; Marré, Daniele; Pellegrino, Luca

    2015-10-01

    We investigate the resistive switching behaviour of VO2 microbridges under current bias as a function of temperature and thermal coupling with the heat bath. Upon increasing the electrical current bias, the formation of the metallic phase can progress smoothly or through sharp jumps. The magnitude and threshold current values of these sharp resistance drops show random behaviour and are dramatically influenced by thermal dissipation conditions. Our results also evidence how the propagation of the metallic phase induced by electrical current in VO2, and thus the shape of the resulting high-conductivity path, are not predictable. We discuss the origin of the switching events through a simple electro-thermal model based on the domain structure of VO2 films that can be useful to improve the stability and controllability of future VO2-based devices.

  9. Influence of growth conditions on the performance of InP nanowire solar cells

    NASA Astrophysics Data System (ADS)

    Cavalli, Alessandro; Cui, Yingchao; Kölling, Sebastian; Verheijen, Marcel A.; Plissard, Sebastien R.; Wang, Jia; Koenraad, Paul M.; Haverkort, Jos E. M.; Bakkers, Erik P. A. M.

    2016-11-01

    Nanowire based solar cells have attracted great attention due to their potential for high efficiency and low device cost. Photovoltaic devices based on InP nanowires now have characteristics comparable to InP bulk solar cells. A detailed and direct correlation of the influence of growth conditions on performance is necessary to improve efficiency further. We explored the effects of the growth temperature, and of the addition of HCl during growth, on the efficiency of nanowire array based solar cell devices. By increasing HCl, the saturation dark current was reduced, and thereby the nanowire solar cell efficiency was enhanced from less than 1% to 7.6% under AM 1.5 illumination at 1 sun. At the same time, we observed that the solar cell efficiency decreased by increasing the tri-methyl-indium content, strongly suggesting that these effects are carbon related.

  10. Pre-slaughter conditions influence skatole and androstenone in adipose tissue of boars.

    PubMed

    Wesoly, Raffael; Jungbluth, Ina; Stefanski, Volker; Weiler, Ulrike

    2015-01-01

    Boar taint in carcasses may vary between farms and abattoirs, although the underlying mechanisms are not yet fully understood. In the present study, 169 boars from three farms were split into two groups and slaughtered at two abattoirs. Duration of transport and the time between arrival at the abattoir and unloading (pre-unloading time) were recorded. During slaughter, blood, feces, and urine were collected to measure testosterone and cortisol levels. Carcasses were classified according to the number of skin lesions, and fat samples were taken to determine skatole, indole and androstenone levels. Androstenone in fat and testosterone in blood, feces, and urine were mainly influenced by the duration of transport. Skatole and indole concentrations were increased by both pre-unloading time and duration of transport, but were also related to skin lesions. Thus it is concluded that androstenone and skatole concentrations in fat are significantly modified by pre-slaughter conditions. PMID:25282669

  11. The influence of culture conditions on the biosynthesis of secondary metabolites by Penicillium verrucosum Dierck.

    PubMed

    Elias, Barbara Casellato; Said, Suraia; de Albuquerque, Sérgio; Pupo, Mônica Tallarico

    2006-01-01

    A Brazilian strain of Penicillium verrucosum was cultivated under different conditions in a two-step process, in order to verify the influence of nutrients, and of time periods of pre-fermentative and fermentative steps on the biosynthesis of metabolites. Extracellular and intracellular extracts were obtained from each culture in the four different production media used. Chemical profiles of the extracts were obtained by HPLC. Extract trypanocidal activities against trypomastigote forms of Trypanosoma cruzi were evaluated. The time period of incubation in the pre-fermentative and fermentative media, as well as the different nutrients tested, qualitatively and quantitatively modified the production of secondary metabolites by P. verrucosum, and the extract trypanocidal activities.

  12. Influence of home cooking conditions on Maillard reaction products in beef.

    PubMed

    Trevisan, Aurea Juliana Bombo; de Almeida Lima, Daniele; Sampaio, Geni Rodrigues; Soares, Rosana Aparecida Manólio; Markowicz Bastos, Deborah Helena

    2016-04-01

    The influence of home cooking methods on the generation of Maillard reaction products (MRP) in beef was investigated. Grilling and frying hamburgers to an internal temperature below 90 °C mainly generated furosine. When the temperature reached 90 °C and 100 °C, furosine content decreased by 36% and fluorescent compounds increased by up to 98%. Baking meat at 300 °C, the most severe heat treatment studied, resulted in the formation of carboxymethyllysine. Boiling in water caused very low MRP formation. Acrylamide concentrations in grilled, fried or baked meat were extremely low. Home cooking conditions leading to low MRP generation and pleasant colours were obtained and could be used to guide diabetic and chronic renal patients on how to reduce their carboxymethyllysine intake.

  13. Optical emission spectroscopy studies of the influence of laserablated mass on dry inductively coupled plasma conditions

    SciTech Connect

    Ciocan, A.C.; Mao, X.L.; Borisov, Oleg V.; Russo, R.E.

    1997-07-01

    The amount of ablated mass can influence the temperature andexcitation characteristics of the inductively coupled plasma (ICP) andmust be taken into account to ensure accurate chemical analysis. The ICPelectron number density was investigated by using measurements of the Mgionic to atomic resonant-line ratios during laser ablation of an aluminummatrix. The ICP excitation temperature was measured by using selected Felines during laser ablation of an iron matrix. A Nd:YAG laser (3 ns pulseduration) at 266 nm was used for these ablation-sampling studies. Laserenergy, power density, and repetition rate were varied in order to changethe quantity of ablated mass into the ICP. Over the range of laseroperating conditions studied herein, the ICP was not significantlyinfluenced by the quantity of solid sample. Therefore, analyticalmeasurements can be performed accurately and fundamental studies of laserablation processes (such as ablation mass roll-off, fractionalvaporization) can be investigated using inductively coupled plasma-atomicemission spectroscopy (ICP-AES).

  14. Hydrodynamism and its influence on the reproductive condition of the edible sea urchin Paracentrotus lividus.

    PubMed

    Gianguzza, Paola; Bonaviri, Chiara; Prato, Ermelinda; Fanelli, Giovanni; Chiantore, Mariachiara; Privitera, Davide; Luzzu, Filippo; Agnetta, Davide

    2013-04-01

    Despite the large body of work published in the last two decades on the reproduction of the sea urchin Paracentrotus lividus, the reproductive aspects linked to hydrodynamic conditions and their influence on gonad production remain poorly understood. The present paper aims to evaluate the effect of hydrodynamism on the reproductive cycle of P. lividus. Variability in the gonadosomatic index (GSI) of P. lividus was estimated seasonally from 2007 to 2008 at two shallow sub-littoral flat basaltic areas at Ustica Island (Western Mediterranean). GSI was higher in the sites characterized by low hydrodynamism than in those with high hydrodynamism. Results also suggest a possible role for hydrodynamism in triggering processes of resource limitation (food shortage), probably by interfering with P. lividus feeding activity. PMID:23333347

  15. Nanosized titanium dioxide influences copper-induced toxicity during aging as a function of environmental conditions.

    PubMed

    Rosenfeldt, Ricki R; Seitz, Frank; Haigis, Ann-Cathrin; Höger, Johanna; Zubrod, Jochen P; Schulz, Ralf; Bundschuh, Mirco

    2016-07-01

    Titanium dioxide nanoparticles (TiO2 -NPs) adsorb co-occurring heavy metals in surface waters, modulating their toxicity for freshwater invertebrates. The processes triggering this interaction may be influenced by several environmental parameters; however, their relative importance remains unclear. The present study assessed the implications of aging on the joint acute toxicity of copper (Cu) and TiO2 -NPs for Daphnia magna over a duration of up to 72 h. The influences of aging duration as well as ionic strength, pH, and presence of different qualities of organic matter during aging were assessed. The results indicated that the presence of TiO2 -NPs often reduced the Cu-induced toxicity for daphnids after aging (albeit with varying extent), which was displayed by up to 3-fold higher EC50 (50% effective concentration) values compared to the absence of TiO2 -NPs. Moreover, the Cu speciation, influenced by the ionic composition and the pH as well as the presence of organic additives in the medium, strongly modulated the processes during aging, with partly limited implications of the aging duration on the ecotoxicological response of D. magna. Nonetheless, the present study underpins the potential of TiO2 -NPs to modify toxicity induced by heavy metals in freshwater ecosystems under various environmental conditions. This pattern, however, needs further verification using heavy metal ions with differing properties in combination with further environmental factors, such as ultraviolet irradiation. Environ Toxicol Chem 2016;35:1766-1774. © 2015 SETAC. PMID:26640248

  16. Relative influence of meteorological conditions and aerosols on the lifetime of mesoscale convective systems.

    PubMed

    Chakraborty, Sudip; Fu, Rong; Massie, Steven T; Stephens, Graeme

    2016-07-01

    Using collocated measurements from geostationary and polar-orbital satellites over tropical continents, we provide a large-scale statistical assessment of the relative influence of aerosols and meteorological conditions on the lifetime of mesoscale convective systems (MCSs). Our results show that MCSs' lifetime increases by 3-24 h when vertical wind shear (VWS) and convective available potential energy (CAPE) are moderate to high and ambient aerosol optical depth (AOD) increases by 1 SD (1σ). However, this influence is not as strong as that of CAPE, relative humidity, and VWS, which increase MCSs' lifetime by 3-30 h, 3-27 h, and 3-30 h per 1σ of these variables and explain up to 36%, 45%, and 34%, respectively, of the variance of the MCSs' lifetime. AOD explains up to 24% of the total variance of MCSs' lifetime during the decay phase. This result is physically consistent with that of the variation of the MCSs' ice water content (IWC) with aerosols, which accounts for 35% and 27% of the total variance of the IWC in convective cores and anvil, respectively, during the decay phase. The effect of aerosols on MCSs' lifetime varies between different continents. AOD appears to explain up to 20-22% of the total variance of MCSs' lifetime over equatorial South America compared with 8% over equatorial Africa. Aerosols over the Indian Ocean can explain 20% of total variance of MCSs' lifetime over South Asia because such MCSs form and develop over the ocean. These regional differences of aerosol impacts may be linked to different meteorological conditions. PMID:27313203

  17. Influence of the postplasma process conditions on the surface conductivity of hydrogenated diamond surfaces

    NASA Astrophysics Data System (ADS)

    Snidero, E.; Tromson, D.; Mer, C.; Bergonzo, P.; Foord, John S.; Nebel, C.; Williams, Oliver A.; Jackman, Richard B.

    2003-03-01

    It is a common observation that diamond surface conductivity rises after exposure to hydrogen plasmas. Hydrogenation treatments are known to induce a p-type conductive layer, which is not present on non-hydrogenated samples. However, the particular mechanisms predominant in the plasma treatment process are still controversial, and several antagonist conditions have been reported to be of importance, such as sample temperature (500 °C to 800 °C), duration (a few seconds to 1 h), and microwave (MW) power density, etc. Further, the post-plasma step is also crucial, especially since the surface conductivity has been reported to be affected by the presence of an adsorbate layer on the diamond surface. By setting up the arrangement to enable the in situ measurement of the surface conductivity after treatment, we have been able to control all parameters that could affect the surface conductivity, in order to determine those of importance. Among the parameters studied, we were able to analyze the influence of the surface temperature, the gas phase exposure (dry air, wet air, neutral gas, CH4, O2, and H2), the MW plasma conditions (O2,H2) as well as the exposure to UV (Hg and deuterium) and the importance of the sequence and duration of each of these treatments. We found that hydrogenated surfaces are strongly influenced by the combination of wet air exposure and UV light. We noticed that the effect of UV light is persistent and cannot be related to direct photoconduction and has to be attributed to a modification of the trapped defect population. This can, therefore, be compared with the modification of filled defect density as observed in persistent photoconduction.

  18. Influence of storage condition on properties of MCC II-based pellets with theophylline-monohydrate.

    PubMed

    Krueger, Cornelia; Thommes, Markus; Kleinebudde, Peter

    2014-10-01

    Microcrystalline cellulose II (MCC II(1)) is a polymorph of commonly used MCC I; in 2010 it was introduced as new pelletization aid in wet-extrusion/spheronization leading to fast disintegrating pellets. Previous investigations suggested that the storage of the resulting pellets affect the disintegration behavior, the non-hygroscopic substance chloramphenicol that showed no polymorphism or hydrate formation due to relative humidity was used for the investigations. Therefore, theophylline-monohydrate that can dehydrate during storage, but also during manufacturing and drying was used for this study to confirm the results of the previous study and give a more detailed overview of the influence of recrystallization of theophylline monohydrate on disintegration. Storage recommendations should be derived. MCC II-based pellets were prepared of binary mixtures containing 10%, 20% or 50% MCCII as pelletization aid and theophylline-monohydrate as API. These pellets were stored at different relative humidity (0-97%rH; 20°C); the influence on their disintegration and drug release was investigated. The storage conditions had an impact on pellet disintegration. Low relative humidities (⩽ 40%rH) led to a conversion of the monohydrate to the anhydrous form. Newly grown crystals formed a kind of network around the pellet and inhibited the disintegration. High relative humidity (>80%rh) affected the disintegration caused by changes in the MCCII as already seen in the previous study. Due to the changed disintegration behavior also the drug release and release kinetic changed. Therefore, for theophylline containing pellets a storage humidity of 55%rH to 80%rH (20°C) is recommended. All in all, these investigations substantiate the knowledge of MCCII-based pellets providing a better basis for adequate storage conditions of MCCII based pellets. PMID:24950003

  19. Influence of storage condition on properties of MCC II-based pellets with theophylline-monohydrate.

    PubMed

    Krueger, Cornelia; Thommes, Markus; Kleinebudde, Peter

    2014-10-01

    Microcrystalline cellulose II (MCC II(1)) is a polymorph of commonly used MCC I; in 2010 it was introduced as new pelletization aid in wet-extrusion/spheronization leading to fast disintegrating pellets. Previous investigations suggested that the storage of the resulting pellets affect the disintegration behavior, the non-hygroscopic substance chloramphenicol that showed no polymorphism or hydrate formation due to relative humidity was used for the investigations. Therefore, theophylline-monohydrate that can dehydrate during storage, but also during manufacturing and drying was used for this study to confirm the results of the previous study and give a more detailed overview of the influence of recrystallization of theophylline monohydrate on disintegration. Storage recommendations should be derived. MCC II-based pellets were prepared of binary mixtures containing 10%, 20% or 50% MCCII as pelletization aid and theophylline-monohydrate as API. These pellets were stored at different relative humidity (0-97%rH; 20°C); the influence on their disintegration and drug release was investigated. The storage conditions had an impact on pellet disintegration. Low relative humidities (⩽ 40%rH) led to a conversion of the monohydrate to the anhydrous form. Newly grown crystals formed a kind of network around the pellet and inhibited the disintegration. High relative humidity (>80%rh) affected the disintegration caused by changes in the MCCII as already seen in the previous study. Due to the changed disintegration behavior also the drug release and release kinetic changed. Therefore, for theophylline containing pellets a storage humidity of 55%rH to 80%rH (20°C) is recommended. All in all, these investigations substantiate the knowledge of MCCII-based pellets providing a better basis for adequate storage conditions of MCCII based pellets.

  20. Relative influence of meteorological conditions and aerosols on the lifetime of mesoscale convective systems

    NASA Astrophysics Data System (ADS)

    Chakraborty, Sudip; Fu, Rong; Massie, Steven T.; Stephens, Graeme

    2016-07-01

    Using collocated measurements from geostationary and polar-orbital satellites over tropical continents, we provide a large-scale statistical assessment of the relative influence of aerosols and meteorological conditions on the lifetime of mesoscale convective systems (MCSs). Our results show that MCSs’ lifetime increases by 3-24 h when vertical wind shear (VWS) and convective available potential energy (CAPE) are moderate to high and ambient aerosol optical depth (AOD) increases by 1 SD (1σ). However, this influence is not as strong as that of CAPE, relative humidity, and VWS, which increase MCSs’ lifetime by 3-30 h, 3-27 h, and 3-30 h per 1σ of these variables and explain up to 36%, 45%, and 34%, respectively, of the variance of the MCSs’ lifetime. AOD explains up to 24% of the total variance of MCSs’ lifetime during the decay phase. This result is physically consistent with that of the variation of the MCSs’ ice water content (IWC) with aerosols, which accounts for 35% and 27% of the total variance of the IWC in convective cores and anvil, respectively, during the decay phase. The effect of aerosols on MCSs’ lifetime varies between different continents. AOD appears to explain up to 20-22% of the total variance of MCSs’ lifetime over equatorial South America compared with 8% over equatorial Africa. Aerosols over the Indian Ocean can explain 20% of total variance of MCSs’ lifetime over South Asia because such MCSs form and develop over the ocean. These regional differences of aerosol impacts may be linked to different meteorological conditions.

  1. The Influence of Coral Reef Benthic Condition on Associated Fish Assemblages

    PubMed Central

    Chong-Seng, Karen M.; Mannering, Thomas D.; Pratchett, Morgan S.; Bellwood, David R.; Graham, Nicholas A. J.

    2012-01-01

    Accumulative disturbances can erode a coral reef’s resilience, often leading to replacement of scleractinian corals by macroalgae or other non-coral organisms. These degraded reef systems have been mostly described based on changes in the composition of the reef benthos, and there is little understanding of how such changes are influenced by, and in turn influence, other components of the reef ecosystem. This study investigated the spatial variation in benthic communities on fringing reefs around the inner Seychelles islands. Specifically, relationships between benthic composition and the underlying substrata, as well as the associated fish assemblages were assessed. High variability in benthic composition was found among reefs, with a gradient from high coral cover (up to 58%) and high structural complexity to high macroalgae cover (up to 95%) and low structural complexity at the extremes. This gradient was associated with declining species richness of fishes, reduced diversity of fish functional groups, and lower abundance of corallivorous fishes. There were no reciprocal increases in herbivorous fish abundances, and relationships with other fish functional groups and total fish abundance were weak. Reefs grouping at the extremes of complex coral habitats or low-complexity macroalgal habitats displayed markedly different fish communities, with only two species of benthic invertebrate feeding fishes in greater abundance in the macroalgal habitat. These results have negative implications for the continuation of many coral reef ecosystem processes and services if more reefs shift to extreme degraded conditions dominated by macroalgae. PMID:22870294

  2. Influence of thermal buoyancy on vertical tube bundle thermal density head predictions under transient conditions. [LMFBR

    SciTech Connect

    Lin, H.C.; Kasza, K.E.

    1984-01-01

    The thermal-hydraulic behavior of an LMFBR system under various types of plant transients is usually studied using one-dimensional (1-D) flow and energy transport models of the system components. Many of the transient events involve the change from a high to a low flow with an accompanying change in temperature of the fluid passing through the components which can be conductive to significant thermal bouyancy forces. Thermal bouyancy can exert its influence on system dynamic energy transport predictions through alterations of flow and thermal distributions which in turn can influence decay heat removal, system-response time constants, heat transport between primary and secondary systems, and thermal energy rejection at the reactor heat sink, i.e., the steam generator. In this paper the results from a comparison of a 1-D model prediction and experimental data for vertical tube bundle overall thermal density head and outlet temperature under transient conditions causing varying degrees of thermal bouyancy are presented. These comparisons are being used to generate insight into how, when, and to what degree thermal buoyancy can cause departures from 1-D model predictions.

  3. Quantifying the local influence at a tall tower site in nocturnal conditions

    NASA Astrophysics Data System (ADS)

    Werth, David; Buckley, Robert; Zhang, Gengsheng; Kurzeja, Robert; Leclerc, Monique; Duarte, Henrique; Parker, Matthew; Watson, Thomas

    2015-10-01

    The influence of the local terrestrial environment on nocturnal atmospheric CO2 measurements at a 329-m television transmitter tower (and a component of a CO2 monitoring network) was estimated with a tracer release experiment and a subsequent simulation of the releases. This was done to characterize the vertical transport of emissions from the surface to the uppermost tower level and how it is affected by atmospheric stability. The tracer release experiment was conducted over two nights in May of 2009 near the Department of Energy's Savannah River Site (SRS) in South Carolina. Tracer was released on two contrasting nights—slightly stable and moderately stable—from several upwind surface locations. Measurements at the 329-m level on both nights indicate that tracer was able to mix vertically within a relatively short (˜24 km) distance, implying that nocturnal stable conditions do not necessarily prevent vertical dispersion in the boundary layer and that CO2 measurements at the tower are at least partly influenced by nearby emissions. A simulation of the tracer release is used to calculate the tower footprint on the two nights to estimate the degree to which the local domain affects the tower readings. The effect of the nocturnal boundary layer on the area sampled by the tower can be seen clearly, as the footprints were affected by changes in stability. The contribution of local sources to the measurements at the tower was minimal, however, suggesting that nocturnal concentrations at upper levels are contributed mostly by regional sources.

  4. Invasive earthworms interact with abiotic conditions to influence the invasion of common buckthorn (Rhamnus cathartica).

    PubMed

    Roth, Alexander M; Whitfeld, Timothy J S; Lodge, Alexandra G; Eisenhauer, Nico; Frelich, Lee E; Reich, Peter B

    2015-05-01

    Common buckthorn (Rhamnus cathartica L.) is one of the most abundant and ecologically harmful non-native plants in forests of the Upper Midwest United States. At the same time, European earthworms are invading previously glaciated areas in this region, with largely anecdotal evidence suggesting they compound the negative effects of buckthorn and influence the invasibility of these forests. Germination and seedling establishment are important control points for colonization by any species, and manipulation of the conditions influencing these life history stages may provide insight into why invasive species are successful in some environments and not others. Using a greenhouse microcosm experiment, we examined the effects of important biotic and abiotic factors on the germination and seedling establishment of common buckthorn. We manipulated light levels, leaf litter depth and earthworm presence to investigate the independent and interactive effects of these treatments on buckthorn establishment. We found that light and leaf litter depth were significant predictors of buckthorn germination but that the presence of earthworms was the most important factor; earthworms interacted with light and leaf litter to increase the number and biomass of buckthorn across all treatments. Path analysis suggested both direct and moisture-mediated indirect mechanisms controlled these processes. The results suggest that the action of earthworms may provide a pathway through which buckthorn invades forests of the Upper Midwest United States. Hence, researchers and managers should consider co-invasion of plants and earthworms when investigating invasibility and creating preemptive or post-invasion management plans.

  5. Rainforest air-conditioning: the moderating influence of epiphytes on the microclimate in tropical tree crowns

    NASA Astrophysics Data System (ADS)

    Stuntz, Sabine; Simon, Ulrich; Zotz, Gerhard

    2002-05-01

    Epiphytes are often assumed to influence the microclimatic conditions of the tree crowns that they inhabit. In order to quantify this notion, we measured the parameters "temperature" (of the substrate surface and the boundary layer of air above it), "evaporative drying rate" and "evapotranspiration" at various locations within tree crowns with differing epiphyte assemblages. The host tree species was Annona glabra, which was either populated by one of three epiphyte species ( Dimerandra emarginata, Tillandsia fasciculata, or Vriesea sanguinolenta) or was epiphyte-free. We found that during the hottest and driest time of day, microsites in the immediate proximity of epiphytes had significantly lower temperatures than epiphyte-bare locations within the same tree crown, even though the latter were also shaded by host tree foliage or branches. Moreover, water loss through evaporative drying at microsites adjacent to epiphytes was almost 20% lower than at exposed microsites. We also found that, over the course of several weeks, the evapotranspiration in tree crowns bearing epiphytes was significantly lower than in trees without epiphytes. Although the influence of epiphytes on temperature extremes and evaporation rates is relatively subtle, their mitigating effect could be of importance for small animals like arthropods inhabiting an environment as harsh and extreme as the tropical forest canopy.

  6. Influence of experimental conditions on data variability in the liver comet assay.

    PubMed

    Guérard, M; Marchand, C; Plappert-Helbig, U

    2014-03-01

    The in vivo comet assay has increasingly been used for regulatory genotoxicity testing in recent years. While it has been demonstrated that the experimental execution of the assay, for example, electrophoresis or scoring, can have a strong impact on the results; little is known on how initial steps, that is, from tissue sampling during necropsy up to slide preparation, can influence the comet assay results. Therefore, we investigated which of the multitude of steps in processing the liver for the comet assay are most critical. All together eight parameters were assessed by using liver samples of untreated animals. In addition, two of those parameters (temperature and storage time of liver before embedding into agarose) were further investigated in animals given a single oral dose of ethyl methanesulfonate at dose levels of 50, 100, and 200 mg/kg, 3 hr prior to necropsy. The results showed that sample cooling emerged as the predominant influence factor, whereas variations in other elements of the procedure (e.g., size of the liver piece sampled, time needed to process the liver tissue post-mortem, agarose temperature, or time of lysis) seem to be of little relevance. Storing of liver samples of up to 6 hr under cooled conditions did not cause an increase in tail intensity. In contrast, storing the tissue at room temperature, resulted in a considerable time-dependent increase in comet parameters.

  7. TECNAIRE winter field campaign: turbulent characteristics and their influence on air quality conditions

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    An urban field campaign was conducted at an air pollution hot spot in Madrid city (Spain) during winter 2015 (from 16th February to 2nd March). The zone selected for the study is a square (Plaza Fernández Ladreda) located in the southern part of the city. This area is an important intersection of several principal routes, and therefore a significant impact in the air quality of the area is found due to the high traffic density. Meteorological data (wind speed and direction, air temperature, relative humidity, pressure, precipitation and global solar radiation) were daily recorded as well as micrometeorological measurements obtained from two sonic anemometers. To characterize this urban atmospheric boundary layer (uABL), micrometeorological parameters (turbulent kinetic energy -TKE-, friction velocity -u∗- and sensible heat flux -H-) are calculated, considering 5-minute average for variance and covariance evaluations. Furthermore, synoptic atmospheric features were analyzed. As a whole, a predominant influence of high pressure systems was found over the Atlantic Ocean and western Spain, affecting Madrid, but during a couple of days (17th and 21st February) some atmospheric instability played a role. The influence of the synoptic situation and specially the evolution of the micrometeorological conditions along the day on air quality characteristics (Particulate Matter concentrations: PM10, PM2.5 and PM1, and NOx concentrations) are analyzed and shown in detail. This work has been financed by Madrid Regional Research Plan through TECNAIRE (P2013/MAE-2972).

  8. How a seven-year ocean observatory is influencing our understanding of physical and biological processes in northern Arabian Sea?

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Dimarco, S. F.; Al-Kharusi, L. H.; Belabbassi, L.; Ingle, S.

    2012-12-01

    An ocean observatory—consisting of a real-time, cabled system in the Sea of Oman and an internally-recording, autonomous mooring system recently upgraded to a cabled system in the northern Arabian Sea—was installed in 2005. The two arrays have collected a continuous seven-year time series record of current velocities, temperature, pressure, salinity, dissolved oxygen, and turbidity in a region where several water masses converge and subsequently spread southward to the Indian Ocean. The systems have provided new insights into physical and biological oceanographic processes of the northwestern Indian Ocean, which is strongly affected by the monsoonal oscillation, along with lessons learned and best practices in the operation and application of ocean observatories to ocean science. In this presentation, we show four recent studies for the scientific highlights derived from the data collected from the two systems and supporting data from other sources. The topics of those four studies include: (1) The seasonality associated with the upwelling of low oxygen water on the northern Oman coast and insights on the inter-annual variability of this process; (2) The deep-water oceanic responses excited by the passage of Cyclone Gonu, the largest-ever recorded cyclone in the region; (3) The temporal and spatial evolution of an acoustic backscatter layer; (4) The pulse-like salinity/temperature events in the northeastern Arabian Sea and Gulf of Oman. In summary, the observatory provides a long-term time series with which to perform basic scientific research related to characterizing the general dynamical patterns of the region, quantifying seasonal variability of water column properties, and establishing a time series of sufficient duration to deduce the potential impacts of climate change. Furthermore, observations taken over the full, 20+ year lifetime of a typical cabled system will be extremely useful for evaluating numerical ocean circulation and coupled atmospheric

  9. Functional Genomics of Cardioprotection by Ischemic Conditioning and the Influence of Comorbid Conditions: Implications in Target Identification.

    PubMed

    Varga, Zoltan V; Giricz, Zoltan; Bencsik, Peter; Madonna, Rosalinda; Gyongyosi, Mariann; Schulz, Rainer; Mayr, Manuel; Thum, Thomas; Puskas, Laszlo G; Ferdinandy, Peter

    2015-01-01

    Ischemic heart disease including myocardial infarction develops on the basis of several risk-factors and comorbidities such as obesity, diabetes, hypertension, and hypercholesterolemia. Ischemic heart disease is the leading cause of mortality worldwide, therefore, identification of novel drug targets for cardioprotection is of great importance. Ischemic preconditioning, postconditioning, and remote conditioning trigger endogenous cardioprotective mechanisms that render the heart more resistant to lethal ischemic-reperfusion injury. However, major cardiovascular co-morbidities such as hyperlipidemia, diabetes, and their co-medications interfere with these cardioprotective mechanisms thereby limiting the efficacy of cardioprotective ischemic conditioning maneuvers. Ischemia reperfusion injury and cardioprotection by conditioning have been shown to affect global myocardial gene expression profile at the transcript level. Further understanding and the comprehensive analysis of the cardioprotective gene expression fingerprint in normal, protected, and in comorbid conditions may lead to identification of novel molecular targets for cardioprotection.

  10. Winter conditioning of the Cascadian margin upwelling system: Remote forcing and coastal river influences (Invited)

    NASA Astrophysics Data System (ADS)

    Hales, B. R.; Goni, M. A.; Evans, W.; Harris, K. E.; Siedlecki, S. A.; Skyllingstad, E. D.; Wall, C.; Wetz, M.; White, A. E.

    2013-12-01

    The Cascadian margin stretches along the North American Pacific coast from Cape Mendocino to Vancouver Island, and across the land-ocean margin from the crest of the coastal mountains to the California Current. Carbonate system chemistry in these coastal waters is among the most dynamic in the world, with high net community productivity driving the system to a regionally important CO2 sink, while upwelled, respiration-influenced waters carry such elevated CO2 that they are often corrosive to biogenic carbonates. Most of the focus on this ecosystem has been on the influence of the seasonal upwelling and interaction with the upper thermocline of the ocean interior; recently, however, the downwelling-season has been recognized as critical in shaping the carbon cycling of the ecosystem. We present a combination of in-water survey and mooring data from river, estuary, and shelf waters; remote-sensing of coastal surface waters and watershed precipitation; and modeling results describing the physics of coastal circulation and storm-event precipitation and river discharge that shows how the winter conditions control carbon cycling. Coastally-trapped internal waves propagating northward from remote upwelling regions to the south lead to shoaling of the pycnocline such that upwelled source waters are present far inshore of the shelfbreak months before the onset of upwelling favorable winds. The close proximity of upwelled source waters to inner shelf upwelling locations leads to rapid transition in response to late winter and early spring upwelling favorable wind events. Winter storms and closely coupled flooding events deliver regionally significant amounts of nutrient-rich, low-CO2 fresh waters to the coastal ocean during downwelling conditions that retain these inputs on the shelf, and this fuels phytoplankton blooms that are a significant contribution to the annual net community production. These blooms and river influences maintain low coastal surface water pCO2 during

  11. The Flushing of the Northern Lower Stratosphere and the Influence of the Monsoon: Results from Tacts/Esmval 2012

    NASA Astrophysics Data System (ADS)

    Hoor, P. M.; Mueller, S.; Bozem, H.; Fischer, H.; Gute, E.; Engel, A.; Boenisch, H.; Keber, T.; Zahn, A.; Kraemer, M.; Schlager, H.; Wernli, H.; Vogel, B.

    2014-12-01

    We present results from the German research aircraft HALO during the TACTS/ESMVal project (Transport and Composition in the UT/LMS and Earth System Model Validationj). Global measurements of various trace species were performed from the arctic to the early antarctic vortex in August to September 2012. Here, we focus on the northern hemispheric distribution of CO, N2O and ozone above 380 K. In this region we could for the first time identify mixing lines, which indicate mixing between stratospheric air masses of different origin. Introducing a new pair of correlation species (N2O-CO) we could identify air masses, which do not involve mixing directly at the tropopause. The use of CO-N2O correlations provides additional knowledge on the end members and therefore the reservoirs involved in the mixing processes within the stratosphere compared to the CO-O3-correlation. Trace gas distributions for the atmospheric region between the extratropical tropopause and potential temperatures up to Θ = 405 K indicate mixing of 'young' stratospheric air with aged processed air. Backward trajectories indicate that the "younger" stratospheric air masses originate in the Asian monsoon region and contribute to the chemical composition of air above Θ = 380 K, thereby circumventing the TTL region. Therefore we conclude that the monsoon significantly contributes to the flushing of the extratropical UTLS during summer and autumn.

  12. The Influence of Mining and Human Immunodeficiency Virus Infection Among Patients Admitted for Retreatment of Tuberculosis in Northern Tanzania.

    PubMed

    Mpagama, Stellah G; Lekule, Isaack A; Mbuya, Alexander W; Kisonga, Riziki M; Heysell, Scott K

    2015-08-01

    In tuberculosis (TB)-prevalent settings, patients admitted for retreatment of TB may account for a high burden of poor treatment outcome. We performed a retrospective cohort study to characterize retreatment patients and outcomes at a TB referral hospital in northern Tanzania. From 2009 to 2013, 185 patients began a retreatment regimen, the majority for relapse after prior treatment completion. Men accounted for an unexpected majority (88%), 36 (20%) were human immunodeficiency virus (HIV) infected and for 45 (24%) mining was their primary occupation. A poor outcome (death, default, or persistent smear positivity after 7 months of treatment) was found in 37 (23%). HIV infection was the only significant predictor of poor outcome (adjusted odds ratio [aOR] = 2.50, 95% confidence interval [CI] = 1.07-5.83, P = 0.034). Interventions to minimize need for retreatment or improve retreatment success may be regionally specific. In our setting, community-based diagnosis and management among at-risk subpopulations such as miners and those HIV infected appear of highest yield.

  13. The Influence of Mining and Human Immunodeficiency Virus Infection among Patients Admitted for Retreatment of Tuberculosis in Northern Tanzania

    PubMed Central

    Mpagama, Stellah G.; Lekule, Isaack A.; Mbuya, Alexander W.; Kisonga, Riziki M.; Heysell, Scott K.

    2015-01-01

    In tuberculosis (TB)–prevalent settings, patients admitted for retreatment of TB may account for a high burden of poor treatment outcome. We performed a retrospective cohort study to characterize retreatment patients and outcomes at a TB referral hospital in northern Tanzania. From 2009 to 2013, 185 patients began a retreatment regimen, the majority for relapse after prior treatment completion. Men accounted for an unexpected majority (88%), 36 (20%) were human immunodeficiency virus (HIV) infected and for 45 (24%) mining was their primary occupation. A poor outcome (death, default, or persistent smear positivity after 7 months of treatment) was found in 37 (23%). HIV infection was the only significant predictor of poor outcome (adjusted odds ratio [aOR] = 2.50, 95% confidence interval [CI] = 1.07–5.83, P = 0.034). Interventions to minimize need for retreatment or improve retreatment success may be regionally specific. In our setting, community-based diagnosis and management among at-risk subpopulations such as miners and those HIV infected appear of highest yield. PMID:26013368

  14. Bioethanol production from Scenedesmus obliquus sugars: the influence of photobioreactors and culture conditions on biomass production.

    PubMed

    Miranda, J R; Passarinho, P C; Gouveia, L

    2012-10-01

    A closed-loop vertical tubular photobioreactor (PBR), specially designed to operate under conditions of scarce flat land availability and irregular solar irradiance conditions, was used to study the potential of Scenedesmus obliquus biomass/sugar production. The results obtained were compared to those from an open-raceway pond and a closed-bubble column. The influence of the type of light source and the regime (natural vs artificial and continuous vs light/dark cycles) on the growth of the microalga and the extent of the sugar accumulation was studied in both PBRs. The best type of reactor studied was a closed-loop PBR illuminated with natural light/dark cycles. In all the cases, the relationship between the nitrate depletion and the sugar accumulation was observed. The microalga Scenedesmus was cultivated for 53 days in a raceway pond (4,500 L) and accumulated a maximum sugar content of 29 % g/g. It was pre-treated for carrying out ethanol fermentation assays, and the highest ethanol concentration obtained in the hydrolysate fermented by Kluyveromyces marxianus was 11.7 g/L. PMID:22899495

  15. Experimental investigation of the influence of inlet conditions to a bluff body wake

    NASA Astrophysics Data System (ADS)

    Fallenius, Bengt; Fransson, Jens

    2010-11-01

    Wind tunnel experiments have been performed in a bluff body wake with varying inlet conditions in order to enhance the physical understanding of the wake flow instability, which may lead to successful flow control and in turn reduced aerodynamic drag. The geometry consists of a rectangular-based forebody with permeable surfaces, an elliptic leading edge and a blunt trailing edge. Length, width and base height of the forebody is 2.3, 0.5 and 0.04 meters, respectively. Applying continuous suction or blowing, of different levels, through the permeable surfaces along the forebody, varies the wall-normal trailing edge velocity profile in a systematic way and hence the inlet condition to the wake. The streamwise velocity component has been measured both throughout the boundary layer and in the wake behind the body using hot-wire anemometry. High-speed stereo PIV has been used in the wake in order to collect statistics of vortical structures in the wake. The influence of boundary layer parameters on the wake flow characteristics, such as vortex shedding frequency and base pressure, will be presented.

  16. Bioethanol production from Scenedesmus obliquus sugars: the influence of photobioreactors and culture conditions on biomass production.

    PubMed

    Miranda, J R; Passarinho, P C; Gouveia, L

    2012-10-01

    A closed-loop vertical tubular photobioreactor (PBR), specially designed to operate under conditions of scarce flat land availability and irregular solar irradiance conditions, was used to study the potential of Scenedesmus obliquus biomass/sugar production. The results obtained were compared to those from an open-raceway pond and a closed-bubble column. The influence of the type of light source and the regime (natural vs artificial and continuous vs light/dark cycles) on the growth of the microalga and the extent of the sugar accumulation was studied in both PBRs. The best type of reactor studied was a closed-loop PBR illuminated with natural light/dark cycles. In all the cases, the relationship between the nitrate depletion and the sugar accumulation was observed. The microalga Scenedesmus was cultivated for 53 days in a raceway pond (4,500 L) and accumulated a maximum sugar content of 29 % g/g. It was pre-treated for carrying out ethanol fermentation assays, and the highest ethanol concentration obtained in the hydrolysate fermented by Kluyveromyces marxianus was 11.7 g/L.

  17. Influence of Crystal Growth Cooling Conditions on Thermoelectric Properties of Aurivillius Phase Bi-V-O

    NASA Astrophysics Data System (ADS)

    Kohri, Hitoshi; Segawa, Mizuki; Yagasaki, Takayoshi

    2016-11-01

    Aurivillius phase Bi2VO5.5 is known as an oxygen ion conductor. In previous studies on Bi2VO5.5, the Seebeck coefficient of the sintered body was about 10 mVK-1 at 800 K. However, the resistivity was 103 Ω m at 800 K. It seemed that this high resistivity was caused by high grain boundary resistance because of cracks at boundaries. In this study, specimens have been prepared by a melting method, aimed at reducing the boundaries. The influence of crystal growth cooling conditions on the thermoelectric properties of Aurivillius phase Bi-V-O is discussed. The crystal growth cooling conditions investigated were slow cooling with cooling rate of 9 K h-1, furnace cooling, and quenching. The surface and cross-section of the sample were observed by scanning electron microscopy (SEM). The crystalline phase was identified by x-ray diffraction (XRD) analysis. The resistivity was measured by the direct current (DC) two or four terminals method. The Seebeck coefficient was measured by the small temperature difference method. The transgranular resistance and grain boundary resistance were evaluated by the complex impedance method. All samples consisted of layered grains. The grain thickness at cross section decreased with increasing cooling rate. The resistivity of the quenched and slowly cooled specimens was approximately 1000 times lower compared with the furnace cooled specimen and sintered body over the measured temperature range.

  18. Influence of taro (Colocasia esculenta L. Shott) growth conditions on the phenolic composition and biological properties.

    PubMed

    Gonçalves, Rui F; Silva, Artur M S; Silva, Ana Margarida; Valentão, Patrícia; Ferreres, Federico; Gil-Izquierdo, Angel; Silva, João B; Santos, Delfim; Andrade, Paula B

    2013-12-15

    Colocasia esculenta (L.) Shott, commonly known as taro, is an essential food for millions of people. The leaves are consumed in sauces, purees, stews, and soups, being also used in wound healing treatment. Nowadays, the consumers' demand for bioactive compounds from the diet led to the development of new agricultural strategies for the production of health-promoting constituents in vegetables. In this work, two strategies (variety choice and irrigation conditions) were considered in the cultivation of C. esculenta. The effect on the phenolic composition of the leaves was evaluated. Furthermore, a correlation between the biological activity of the different varieties and their chemical composition was established. Qualitative and quantitative differences in the phenolic composition were observed between varieties; furthermore, the irrigation conditions also influenced the composition. C. esculenta varieties were able to scavenge several oxidant species and to inhibit hyaluronidase, but data suggest that metabolites other than phenolics are involved. The results show that cultivation strategies can effectively modulate the accumulation of these types of bioactive compounds. Furthermore C. esculenta wound healing potential can be attributed, at least in part, to the protection of the wound site against oxidative/nitrosative damage and prevention of hyaluronic acid degradation.

  19. Immobilization of selenate by iron in aqueous solution under anoxic conditions and the influence of uranyl

    NASA Astrophysics Data System (ADS)

    Puranen, Anders; Jonsson, Mats; Dähn, Rainer; Cui, Daqing

    2009-08-01

    In proposed high level radioactive waste repositories a large part of the spent nuclear fuel (SNF) canisters are commonly composed of iron. Selenium is present in spent nuclear fuel as a long lived fission product. This study investigates the influence of iron on the uptake of dissolved selenium in the form of selenate and the effect of the presence of dissolved uranyl on the above interaction of selenate. The iron oxide, and selenium speciation on the surfaces was investigated by Raman spectroscopy. X-ray Absorption Spectroscopy was used to determine the oxidation state of the selenium and uranium on the surfaces. Under the simulated groundwater conditions (10 mM NaCl, 2 mM NaHCO 3, <0.1 ppm O 2) the immobilized selenate was found to be reduced to oxidation states close to zero or lower and uranyl was found to be largely reduced to U(IV). The near simultaneous reduction of uranyl was found to greatly enhance the rate of selenate reduction. These findings suggest that the presence of uranyl being reduced by an iron surface could substantially enhance the rate of reduction of selenate under anoxic conditions relevant for a repository.

  20. Influence of Crystal Growth Cooling Conditions on Thermoelectric Properties of Aurivillius Phase Bi-V-O

    NASA Astrophysics Data System (ADS)

    Kohri, Hitoshi; Segawa, Mizuki; Yagasaki, Takayoshi

    2016-08-01

    Aurivillius phase Bi2VO5.5 is known as an oxygen ion conductor. In previous studies on Bi2VO5.5, the Seebeck coefficient of the sintered body was about 10 mVK-1 at 800 K. However, the resistivity was 103 Ω m at 800 K. It seemed that this high resistivity was caused by high grain boundary resistance because of cracks at boundaries. In this study, specimens have been prepared by a melting method, aimed at reducing the boundaries. The influence of crystal growth cooling conditions on the thermoelectric properties of Aurivillius phase Bi-V-O is discussed. The crystal growth cooling conditions investigated were slow cooling with cooling rate of 9 K h-1, furnace cooling, and quenching. The surface and cross-section of the sample were observed by scanning electron microscopy (SEM). The crystalline phase was identified by x-ray diffraction (XRD) analysis. The resistivity was measured by the direct current (DC) two or four terminals method. The Seebeck coefficient was measured by the small temperature difference method. The transgranular resistance and grain boundary resistance were evaluated by the complex impedance method. All samples consisted of layered grains. The grain thickness at cross section decreased with increasing cooling rate. The resistivity of the quenched and slowly cooled specimens was approximately 1000 times lower compared with the furnace cooled specimen and sintered body over the measured temperature range.

  1. Influence of raised plastic floors compared with pine shaving litter on environment and Pekin duck condition.

    PubMed

    Karcher, D M; Makagon, M M; Fraley, G S; Fraley, S M; Lilburn, M S

    2013-03-01

    Commercial poultry production management practices have been under increased public scrutiny driven by concerns for food safety and animal welfare. Within the United States, wood shavings and raised plastic floors are common flooring systems used in duck production. It is intuitive that each flooring type would present different management challenges influencing physical characteristics of growing ducks. This study evaluated the relationship between flooring type and duck condition during the winter. Random samples of 20 ducks from 5 predetermined areas (n = 100) were examined in commercial duck houses (n = 9, litter; n = 11, raised plastic slats). Ducks were assessed at 7, 21, and 32 d of age for eye, nostril, and feather cleanliness, feather and foot pad quality, and gait. The data were analyzed to determine the proportion of ducks with a given score. In both housing types, the proportion of 0 scores for foot pad quality improved during the production cycle (P < 0.0001). Feather hygiene declined with age in ducks reared on litter flooring, whereas ducks reared on slatted flooring had cleaner feathers at d 32 (P < 0.011). With the exception of foot pad scores, the majority of ducks had no detectable problems for any single trait. The only main effect due to flooring pertained to feather quality with the proportion of ducks having a 0 or 1 score greater in litter flooring systems than slats (P < 0.05). Overall, the condition of ducks reared, regardless of flooring system, was considered to be good.

  2. Influence of taro (Colocasia esculenta L. Shott) growth conditions on the phenolic composition and biological properties.

    PubMed

    Gonçalves, Rui F; Silva, Artur M S; Silva, Ana Margarida; Valentão, Patrícia; Ferreres, Federico; Gil-Izquierdo, Angel; Silva, João B; Santos, Delfim; Andrade, Paula B

    2013-12-15

    Colocasia esculenta (L.) Shott, commonly known as taro, is an essential food for millions of people. The leaves are consumed in sauces, purees, stews, and soups, being also used in wound healing treatment. Nowadays, the consumers' demand for bioactive compounds from the diet led to the development of new agricultural strategies for the production of health-promoting constituents in vegetables. In this work, two strategies (variety choice and irrigation conditions) were considered in the cultivation of C. esculenta. The effect on the phenolic composition of the leaves was evaluated. Furthermore, a correlation between the biological activity of the different varieties and their chemical composition was established. Qualitative and quantitative differences in the phenolic composition were observed between varieties; furthermore, the irrigation conditions also influenced the composition. C. esculenta varieties were able to scavenge several oxidant species and to inhibit hyaluronidase, but data suggest that metabolites other than phenolics are involved. The results show that cultivation strategies can effectively modulate the accumulation of these types of bioactive compounds. Furthermore C. esculenta wound healing potential can be attributed, at least in part, to the protection of the wound site against oxidative/nitrosative damage and prevention of hyaluronic acid degradation. PMID:23993510

  3. Gramicidin channel-induced lipid membrane deformation energy: influence of chain length and boundary conditions.

    PubMed

    Ring, A

    1996-01-31

    The influence of boundary conditions on the deformation energy of a lipid membrane containing a gramicidin A channel was evaluated numerically. A liquid crystal model was used to calculate the relative contributions of compression, splay and surface tension. It is proposed that the nearest neighbor lipid molecules are displaced from the channel end in a direction perpendicular to the bilayer and it is concluded that surface tension is the major component of the deformation free energy for monoolein (gmo)/n-alkane membranes. This unexpected result supports the validity of the liquid crystal models of membrane deformation since gramicidin lifetime has been shown to correlate with surface tension for gmo membranes. The theory accurately predicts the experimentally measured relative lifetimes without the use of adjustable parameters. For conditions where splay may be neglected surface tension is always the major component of the deformation energy, irrespective of the magnitude of the compression coefficient. The deformation may extend for hundreds of angstroms from the peptide. The results obtained here are expected to be important for the characterization of protein-membrane interactions in general.

  4. Habitat conditions and phenological tree traits overrule the influence of tree genotype in the needle mycobiome-Picea glauca system at an arctic treeline ecotone.

    PubMed

    Eusemann, Pascal; Schnittler, Martin; Nilsson, R Henrik; Jumpponen, Ari; Dahl, Mathilde B; Würth, David G; Buras, Allan; Wilmking, Martin; Unterseher, Martin

    2016-09-01

    Plant-associated mycobiomes in extreme habitats are understudied and poorly understood. We analysed Illumina-generated ITS1 sequences from the needle mycobiome of white spruce (Picea glauca) at the northern treeline in Alaska (USA). Sequences were obtained from the same DNA that was used for tree genotyping. In the present study, fungal metabarcoding and tree microsatellite data were compared for the first time. In general, neighbouring trees shared more fungal taxa with each other than trees growing in further distance. Mycobiomes correlated strongly with phenological host traits and local habitat characteristics contrasting a dense forest stand with an open treeline site. Genetic similarity between trees did not influence fungal composition and no significant correlation existed between needle mycobiome and tree genotype. Our results suggest the pronounced influence of local habitat conditions and phenotypic tree traits on needle-inhabiting fungi. By contrast, the tree genetic identity cannot be benchmarked as a dominant driver for needle-inhabiting mycobiomes, at least not for white spruce in this extreme environment. PMID:27144386

  5. Influence of Barometric Pressure Changes on Ventilation Conditions in Deep Mines

    NASA Astrophysics Data System (ADS)

    Wasilewski, Stanisław

    2014-10-01

    Barometric air pressure and its changes have a critical impact on ventilation conditions in the underground workings of deep mines. Changes in pressure are particularly important because they are responsible for the transient states of ventilation conditions, therefore, assessing the scale of pressure change is essential. Unfortunately, previously for many years in the Polish mining industry barometric pressure was recorded only on tapes of mechanical barographs by the ventilation department on the surface and therefore such dependencies of methane concentration due to barometric pressure changes have not been properly documented. Today, after the implementation in mines of instruments enabling the monitoring of absolute pressure in the workings of mines (Wasilewski, 2009) the conditions have been created to study the influence of pressure changes on changes of air parameters in the mine workings. Barometric pressure changes were observed and recorded over a course of approximately two years using monitoring system that utilized high accuracy pressure sensors on the surface and in selected workings of an underground mine. This paper presents a statistical analysis of the data that we generated from assessing pressure changes on the surface and at selected underground points in the mine. In the article, which presents the results of the first part of the study, some examples of when significant changes in pressure prior to the tragic events, which were not accompanied by changes in the methane concentration in mine workings, will also be shown. Interestingly, we found that the relationship between methane ignitions and explosions in longwall gob mined via the cave-in method is associated with changes in the barometric pressure. Several instances of methane ignitions and explosions in the gob of cave-in longwalls in recent years were compared with background barometric pressure changes. Research carried out in within the strategic project "Improving work safety in

  6. The influence of temperature on ozone production under varying NOx conditions - a modelling study

    NASA Astrophysics Data System (ADS)

    Coates, Jane; Mar, Kathleen A.; Ojha, Narendra; Butler, Tim M.

    2016-09-01

    Surface ozone is a secondary air pollutant produced during the atmospheric photochemical degradation of emitted volatile organic compounds (VOCs) in the presence of sunlight and nitrogen oxides (NOx). Temperature directly influences ozone production through speeding up the rates of chemical reactions and increasing the emissions of VOCs, such as isoprene, from vegetation. In this study, we used an idealised box model with different chemical mechanisms (Master Chemical Mechanism, MCMv3.2; Common Representative Intermediates, CRIv2; Model for OZone and Related Chemical Tracers, MOZART-4; Regional Acid Deposition Model, RADM2; Carbon Bond Mechanism, CB05) to examine the non-linear relationship between ozone, NOx and temperature, and we compared this to previous observational studies. Under high-NOx conditions, an increase in ozone from 20 to 40 °C of up to 20 ppbv was due to faster reaction rates, while increased isoprene emissions added up to a further 11 ppbv of ozone. The largest inter-mechanism differences were obtained at high temperatures and high-NOx emissions. CB05 and RADM2 simulated more NOx-sensitive chemistry than MCMv3.2, CRIv2 and MOZART-4, which could lead to different mitigation strategies being proposed depending on the chemical mechanism. The increased oxidation rate of emitted VOC with temperature controlled the rate of Ox production; the net influence of peroxy nitrates increased net Ox production per molecule of emitted VOC oxidised. The rate of increase in ozone mixing ratios with temperature from our box model simulations was about half the rate of increase in ozone with temperature observed over central Europe or simulated by a regional chemistry transport model. Modifying the box model set-up to approximate stagnant meteorological conditions increased the rate of increase of ozone with temperature as the accumulation of oxidants enhanced ozone production through the increased production of peroxy radicals from the secondary degradation of

  7. Influences of immunocontraception on time budgets, social behavior, and body condition in feral horses

    USGS Publications Warehouse

    Ransom, J.I.; Cade, B.S.; Hobbs, N.T.

    2010-01-01

    Managers concerned with shrinking habitats and limited resources for wildlife seek effective tools for limiting population growth in some species. Fertility control is one such tool, yet little is known about its impacts on the behavioral ecology of wild, free-roaming animals. We investigated influences of the immunocontraceptive porcine zona pellucida (PZP) on individual and social behavior in bands of feral horses (Equus caballus) in three discrete populations and used 14 hierarchical mixed effect models to gain insight into the influences of PZP treatment on feral horse behavior. A model of body condition was the strongest predictor of feeding, resting, maintenance, and social behaviors, with treated females allocating their time similarly to control females. Time spent feeding declined 11.4% from low condition to high condition females (F1,154 = 26.427, P < 0.001) and was partially reciprocated by a 6.0% increase in resting (F1,154 = 7.629, P = 0.006), 0.9% increase in maintenance (F1,154 = 7.028, P = 0.009), and 1.8% increase in social behavior (F1,154 = 15.064, P < 0.001). There was no difference detected in body condition of treated versus control females (F1,154 = 0.033, P = 0.856), but females with a dependent foal had lower body condition than those without a foal (F1,154 = 4.512, P = 0.038). Herding behavior was best explained by a model of treatment and the interaction of band fidelity and foal presence (AICc weight = 0.660) which estimated no difference in rate of herding behavior directed toward control versus treated females (F1,102 = 0.196, P = 0.659), but resident females without a dependent foal were herded 50.9% more than resident females with a foal (F3,102 = 8.269, P < 0.001). Treated females received 54.5% more reproductive behaviors from stallions than control mares (F1,105 = 5.155, P = 0.025), with the model containing only treatment being the most-supported (AICc weight = 0.530). Treated and control females received harem-tending behaviors

  8. Characterizing drought stress and trait influence on maize yield under current and future conditions.

    PubMed

    Harrison, Matthew T; Tardieu, François; Dong, Zhanshan; Messina, Carlos D; Hammer, Graeme L

    2014-03-01

    Global climate change is predicted to increase temperatures, alter geographical patterns of rainfall and increase the frequency of extreme climatic events. Such changes are likely to alter the timing and magnitude of drought stresses experienced by crops. This study used new developments in the classification of crop water stress to first characterize the typology and frequency of drought-stress patterns experienced by European maize crops and their associated distributions of grain yield, and second determine the influence of the breeding traits anthesis-silking synchrony, maturity and kernel number on yield in different drought-stress scenarios, under current and future climates. Under historical conditions, a low-stress scenario occurred most frequently (ca. 40%), and three other stress types exposing crops to late-season stresses each occurred in ca. 20% of cases. A key revelation shown was that the four patterns will also be the most dominant stress patterns under 2050 conditions. Future frequencies of low drought stress were reduced by ca. 15%, and those of severe water deficit during grain filling increased from 18% to 25%. Despite this, effects of elevated CO2 on crop growth moderated detrimental effects of climate change on yield. Increasing anthesis-silking synchrony had the greatest effect on yield in low drought-stress seasonal patterns, whereas earlier maturity had the greatest effect in crops exposed to severe early-terminal drought stress. Segregating drought-stress patterns into key groups allowed greater insight into the effects of trait perturbation on crop yield under different weather conditions. We demonstrate that for crops exposed to the same drought-stress pattern, trait perturbation under current climates will have a similar impact on yield as that expected in future, even though the frequencies of severe drought stress will increase in future. These results have important ramifications for breeding of maize and have implications for

  9. Influence of Indoor Hygrothermal Conditions on Human Quality of Life in Social Housing

    PubMed Central

    Soares, Sara; Fraga, Silvia; Delgado, Joao M.P.Q.

    2015-01-01

    Background: Modern societies spend most of their time indoors, namely at home, and the indoor environment quality turns out to be a crucial factor to health, quality of life and well-being of the residents. The present study aims to understand how indoor environment relates with quality of life and how improving housing conditions impacts on individuals’ health. Design and Methods: This study case will rely on the following assessments in both rehabilitated and non-rehabilitated social housing: i) field measurements, in social dwellings (namely temperature, relative humidity, carbon dioxide concentration, air velocity, air change rate, level of mould spores and energy consumption); ii) residents’ questionnaires on social, demogaphic, behavioural, health characteristics and quality of life. Also, iii) qualitative interviews performed with social housing residents from the rehabilitated houses, addressing the self-perception of living conditions and their influence in health status and quality of life. All the collected information will be combined and analysed in order to achieve the main objective. Expected impact It is expected to define a Predicted Human Life Quality (PHLQ) index, that combines physical parameters describing the indoor environment measured through engineering techniques with residents’ and neighbourhood quality of life characteristics assessed by health questionnaires. Improvement in social housing should be related with better health indicators and the new index might be an important tool contributing to enhance quality of life of the residents. Significance for public health This study will contribute to understand how indoor environment relates with quality of life and how improving housing conditions impacts on individuals’ health, in social housing neighbourhoods. As so, it is important to share the undertaken methodology carried out by a multidisciplinary team, in order to allow other researchers following comparable studies to

  10. Influence of treatment conditions on the oxidation of micropollutants by Trametes versicolor laccase.

    PubMed

    Margot, Jonas; Maillard, Julien; Rossi, Luca; Barry, D A; Holliger, Christof

    2013-09-25

    Many organic compounds present at low concentrations in municipal wastewater, such as various pharmaceuticals and biocides, are recalcitrant in conventional wastewater treatment plants (WWTPs). To improve their biodegradation, oxidoreductase enzymes such as laccases were tested. The goal was to find optimal conditions for the transformation of two anti-inflammatory pharmaceuticals (diclofenac (DFC) and mefenamic acid (MFA)), one biocide (triclosan (TCN)) and one plastic additive (bisphenol A (BPA)) by Trametes versicolor laccase. Experiments were conducted in spiked solutions at different pH values (from 3 to 9), enzyme concentrations (70-1400 Ul(-1)), reaction times (0-26 hours) and temperatures (10, 25 and 40°C) following a Doehlert experimental design. A semi-empirical model was developed to understand better the combined effects of the four factors and to determine optimal values. This model was able to fit well the experimental data (R(2)>0.97) and showed good predictive ability. All four factors had a significant effect on the micropollutant oxidation with the greatest influence shown by pH. Results for single compounds were different from those obtained for mixtures of micropollutants. For instance, DFC transformation occurred at much higher rates in mixtures under alkaline conditions. Optimal conditions were compound-dependent, but were found to be between pH 4.5 to 6.5 and between 25°C to more than 40°C. A laccase concentration of 730 Ul(-1) was sufficient to obtain a high removal rate (>90%) of the four individual compounds (range of times: 40 min to 5 hours), showing the potential of laccases to improve biodegradation of environmentally persistent compounds. PMID:23831273

  11. Texture-defined objects influence responses of blowfly motion-sensitive neurons under natural dynamical conditions

    PubMed Central

    Ullrich, Thomas W.; Kern, Roland; Egelhaaf, Martin

    2014-01-01

    The responses of visual interneurons of flies involved in the processing of motion information do not only depend on the velocity, but also on other stimulus parameters, such as the contrast and the spatial frequency content of the stimulus pattern. These dependencies have been known for long, but it is still an open question how they affect the neurons’ performance in extracting information about the structure of the environment under the specific dynamical conditions of natural flight. Free-flight of blowflies is characterized by sequences of phases of translational movements lasting for just 30–100 ms interspersed with even shorter and extremely rapid saccade-like rotational shifts in flight and gaze direction. Previous studies already analyzed how nearby objects, leading to relative motion on the retina with respect to a more distant background, influenced the response of a class of fly motion sensitive visual interneurons, the horizontal system (HS) cells. In the present study, we focused on objects that differed from their background by discontinuities either in their brightness contrast or in their spatial frequency content. We found strong object-induced effects on the membrane potential even during the short intersaccadic intervals, if the background contrast was small and the object contrast sufficiently high. The object evoked similar response increments provided that it contained higher spatial frequencies than the background, but not under reversed conditions. This asymmetry in the response behavior is partly a consequence of the depolarization level induced by the background. Thus, our results suggest that, under the specific dynamical conditions of natural flight, i.e., on a very short timescale, the responses of HS cells represent object information depending on the polarity of the difference between object and background contrast and spatial frequency content. PMID:24808836

  12. Influence of season on daytime behavioral activities of donkeys in the Northern Guinea Savanna zone of Nigeria.

    PubMed

    Zakari, Friday Ocheja; Ayo, Joseph Olusegun; Rekwot, Peter Ibrahim; Kawu, Mohammed Umar

    2015-01-01

    The present experiment was performed with the aim of investigating the effect of season on behavioral activities of donkeys during the rainy and harmattan seasons in the Northern Guinea zone of Nigeria. Sixteen apparently healthy donkeys were used as subjects and divided into four groups based on age. During each season, behavioral activities of each donkey were evaluated for three weeks using the focal animal sampling technique. The dry-bulb temperature (DBT), relative humidity (RH), and temperature-humidity index (THI) were obtained three times each day during the experimental period using standard procedures. In the rainy season, the mean DBT (31.65 ± 0.49°C), RH (73.63 ± 1.09%), and THI (84.39 ± 0.71) were significantly (P<0.0001) higher than the corresponding values of 24.00 ± 0.44°C, 36.80 ± 0.92%, and 64.80 ± 0.62 in the harmattan season. During the rainy season, the donkeys spent 60.00 ± 0.77%, 25.40 ± 0.69%, and 2.94 ± 0.21% on grazing, resting, and grooming, respectively. During the harmattan season, the donkeys spent the most time on grazing (76.76 ± 0.43%), less time on resting (11.97 ± 0.38%), and the least time on grooming (0.89 ± 0.05%). In conclusion, season and seasonal variations affect the daytime behavioral activities of donkeys in the zone, and this should be considered in husbandry practices for donkeys. PMID:26858575

  13. Influence of season on daytime behavioral activities of donkeys in the Northern Guinea Savanna zone of Nigeria.

    PubMed

    Zakari, Friday Ocheja; Ayo, Joseph Olusegun; Rekwot, Peter Ibrahim; Kawu, Mohammed Umar

    2015-01-01

    The present experiment was performed with the aim of investigating the effect of season on behavioral activities of donkeys during the rainy and harmattan seasons in the Northern Guinea zone of Nigeria. Sixteen apparently healthy donkeys were used as subjects and divided into four groups based on age. During each season, behavioral activities of each donkey were evaluated for three weeks using the focal animal sampling technique. The dry-bulb temperature (DBT), relative humidity (RH), and temperature-humidity index (THI) were obtained three times each day during the experimental period using standard procedures. In the rainy season, the mean DBT (31.65 ± 0.49°C), RH (73.63 ± 1.09%), and THI (84.39 ± 0.71) were significantly (P<0.0001) higher than the corresponding values of 24.00 ± 0.44°C, 36.80 ± 0.92%, and 64.80 ± 0.62 in the harmattan season. During the rainy season, the donkeys spent 60.00 ± 0.77%, 25.40 ± 0.69%, and 2.94 ± 0.21% on grazing, resting, and grooming, respectively. During the harmattan season, the donkeys spent the most time on grazing (76.76 ± 0.43%), less time on resting (11.97 ± 0.38%), and the least time on grooming (0.89 ± 0.05%). In conclusion, season and seasonal variations affect the daytime behavioral activities of donkeys in the zone, and this should be considered in husbandry practices for donkeys.

  14. Influence of season on daytime behavioral activities of donkeys in the Northern Guinea Savanna zone of Nigeria

    PubMed Central

    ZAKARI, Friday Ocheja; AYO, Joseph Olusegun; REKWOT, Peter Ibrahim; KAWU, Mohammed Umar

    2016-01-01

    ABSTRACT The present experiment was performed with the aim of investigating the effect of season on behavioral activities of donkeys during the rainy and harmattan seasons in the Northern Guinea zone of Nigeria. Sixteen apparently healthy donkeys were used as subjects and divided into four groups based on age. During each season, behavioral activities of each donkey were evaluated for three weeks using the focal animal sampling technique. The dry-bulb temperature (DBT), relative humidity (RH), and temperature-humidity index (THI) were obtained three times each day during the experimental period using standard procedures. In the rainy season, the mean DBT (31.65 ± 0.49°C), RH (73.63 ± 1.09%), and THI (84.39 ± 0.71) were significantly (P<0.0001) higher than the corresponding values of 24.00 ± 0.44°C, 36.80 ± 0.92%, and 64.80 ± 0.62 in the harmattan season. During the rainy season, the donkeys spent 60.00 ± 0.77%, 25.40 ± 0.69%, and 2.94 ± 0.21% on grazing, resting, and grooming, respectively. During the harmattan season, the donkeys spent the most time on grazing (76.76 ± 0.43%), less time on resting (11.97 ± 0.38%), and the least time on grooming (0.89 ± 0.05%). In conclusion, season and seasonal variations affect the daytime behavioral activities of donkeys in the zone, and this should be considered in husbandry practices for donkeys. PMID:26858575

  15. A comparison of rates of hornblende etching in soils in glacial deposits of the northern Rocky Mountains: Influence of climate and characteristics of parent material

    SciTech Connect

    Horn, L.L. . Dept. of Geology); Hall, R.D. . Dept. of Geology)

    1993-04-01

    Etching rates of hornblende grains in the soil matrix of glacial deposits in the Northern Rocky Mountains are dependent primarily upon the influences on soil moisture of the climate and texture of the parent materials. Etching is measured as the deepest penetration of weathering along cleavages. Previous works have shown that hornblende etching is a logarithmic function of depth. Hornblende etching is also a logarithmic function of age of the parent material, with etching rates declining rapidly after initially high rates during the first 10 to 15 kyr after deposition. A comparison of etching rates was made among four chronosequences from the Wind River Range, Wyoming and the Tobacco Root Range, Montana, which have differences in mean annual precipitation (MAP) and texture of the till parent materials. Using rates calculated from both ranges for the first 12 kyr after deposition, etching is slowest (0.02 [mu]m/1,000 yrs) in coarse-textured granitic parent materials where the MAP is 25--40 cm. In contrast, etching is faster by an order of magnitude (0.21 [mu]m/1,000 yrs) where MAP is 110--150 cm and the parent material is finer textured due to about 15% sedimentary rock material mixed with a granitic component. Within individual chronosequences, deposits at higher elevations have accelerated etching rates due to higher orographic precipitation or the influence of late-lying snow. These factors result in higher soil moisture content.

  16. The Influence of Vegetation and Landscape Structural Connectivity on Butterflies (Lepidoptera: Papilionoidea and Hesperiidae), Carabids (Coleoptera: Carabidae), Syrphids (Diptera: Syrphidae), and Sawflies (Hymenoptera: Symphyta) in Northern Italy Farmland.

    PubMed

    Burgio, Giovanni; Sommaggio, Daniele; Marini, Mario; Puppi, Giovanna; Chiarucci, Alessandro; Landi, Sara; Fabbri, Roberto; Pesarini, Fausto; Genghini, Marco; Ferrari, Roberto; Muzzi, Enrico; van Lenteren, Joop C; Masetti, Antonio

    2015-10-01

    Landscape structure as well as local vegetation influence biodiversity in agroecosystems. A study was performed to evaluate the effect of floristic diversity, vegetation patterns, and landscape structural connectivity on butterflies (Lepidoptera: Papilionoidea and Hesperiidae), carabids (Coleoptera: Carabidae), syrphids (Diptera: Syrphidae), and sawflies (Hymenoptera: Symphyta). Vegetation analysis and insect samplings were carried out in nine sites within an intensively farmed landscape in northern Italy. Plant species richness and the percentage of tree, shrub, and herb cover were determined by means of the phytosociological method of Braun-Blanquet. Landscape structural connectivity was measured as the total length of hedgerow network (LHN) in a radius of 500 m around the center of each sampling transect. Butterflies species richness and abundance were positively associated both to herb cover and to plant species richness, but responded negatively to tree and shrub cover. Shrub cover was strictly correlated to both species richness and activity density of carabids. The species richness of syrphids was positively influenced by herb cover and plant richness, whereas their abundance was dependent on ligneous vegetation and LHN. Rarefaction analysis revealed that sawfly sampling was not robust and no relationship could be drawn with either vegetation parameters or structural connectivity. The specific responses of each insect group to the environmental factors should be considered in order to refine and optimize landscape management interventions targeting specific conservation endpoints.

  17. Blood meal analysis, flavivirus screening, and influence of meteorological variables on the dynamics of potential mosquito vectors of West Nile virus in northern Italy.

    PubMed

    Roiz, David; Vazquez, Ana; Rosà, Roberto; Muñoz, Joaquin; Arnoldi, Daniele; Rosso, Fausta; Figuerola, Jordi; Tenorio, Antonio; Rizzoli, Annapaola

    2012-06-01

    An extended area of northern Italy has experienced several West Nile virus (WNV) outbreaks and the emergence of Usutu virus (USUV) during previous years. Our aim was to study some of the factors that could explain disease patterns in the Trentino region, where circulation was detected in human sera and sentinel chickens, but no human or equine cases were reported. We collected Culex species (Diptera: Culicidae) in peridomestic environments. The collected specimens were analyzed for feeding behavior, the influence of temperature and rainfall on the abundance of mosquitoes, and the occurrence of flaviviruses. Analysis of blood meals showed that Culex pipiens fed mainly on blackbirds (Turdus merula) and house sparrows (Passer domesticus), while Culex hortensis fed strictly on lizards. The abundance of Cx. pipiens females correlated positively with mean temperature and negatively with rainfall (one to four weeks before capture). This negative relationship could be due to the direct effect of the flushing of habitats together with an indirect effect of oviposition repellency. The mean weekly temperature influenced the abundance of Cx. hortensis. No flaviviruses were detected in the analyzed Culex mosquitoes. These data suggest a silent cycle at low enzootic transmission levels in the area. Furthermore, we present the first contribution to understanding the transmission role of Cx. pipiens mosquitoes in Italy by identifying vertebrate hosts to species level. PMID:22548533

  18. The Sand Seas of northern China: Important sinks and sources of global sediment fluxes and their changing roles during different climate conditions of Late Quaternary

    NASA Astrophysics Data System (ADS)

    Yang, X.

    2014-12-01

    Although the occurrence of aeolian sands in sedimentary sequences has been widely used as indicators of desert formation or proxies of desert climate, one should be aware that accumulation of aeolian sands does occur along river channels, in lake shores not necessarily associated with arid environment. Our ongoing geomorphological and paleoenvironmental studies in the deserts of northern China reconfirm that formation of sand seas is dependent on not only erodibility (arising from bare surface due to aridity) and wind power but more importantly sand availability related to sediment cycles under interactions between fluvial, lacustrine and aeolian processes. Here we present our ongoing geomorphological and paleoclimatic research on the Late Quaternary landscape and climatic changes in the Taklamkan Desert of northwestern China, the largest sand sea of China in arid zone, and in the Hunshandake Sandy Land at the east part of the Asian mid-latitude desert belt under semiarid climate. We find out that the occurrence of tall sand dunes in the over 300,000 km2 large Taklamakan Sand Sea is closely related to the sites of intensive fluvial sedimentation and convergence zone of surface winds. In the case of Hunshandake, the dunes (although much smaller) mainly occur along the shorelines of the former lake basins, and sediment sources are generally limited because of open hydrological systems in the south and east portions of this desert. The sedimentological and geomorphological records suggest that the climate has changed between arid and less-arid conditions in both of these deserts during Late Quaternary. Under wetter conditions the Taklamakan acts as an important sink of sediments brought by rivers with headwaters in the Tibetan Plateau and Tianshan, while under more arid conditions it acts as an important global sediment source whose dust is transported not only to East Asia and Pacific but also to Greenland ice via westerlies. The Hunshandake has the same pattern of

  19. The influence of spatially and temporally varying oceanographic conditions on meroplanktonic metapopulations

    NASA Astrophysics Data System (ADS)

    Botsford, L. W.; Moloney, C. L.; Hastings, A.; Largier, J. L.; Powell, T. M.; Higgins, K.; Quinn, J. F.

    We synthesize the results of several modelling studies that address the influence of variability in larval transport and survival on the dynamics of marine metapopulations distributed along a coast. Two important benthic invertebrates in the California Current System (CCS), the Dungeness crab and the red sea urchin, are used as examples of the way in which physical oceanographic conditions can influence stability, synchrony and persistence of meroplanktonic metapopulations. We first explore population dynamics of subpopulations and metapopulations. Even without environmental forcing, isolated local subpopulations with density-dependence can vary on time scales roughly twice the generation time at high adult survival, shifting to annual time scales at low survivals. The high frequency behavior is not seen in models of the Dungeness crab, because of their high adult survival rates. Metapopulations with density-dependent recruitment and deterministic larval dispersal fluctuate in an asynchronous fashion. Along the coast, abundance varies on spatial scales which increase with dispersal distance. Coastwide, synchronous, random environmental variability tends to synchronize these metapopulations. Climate change could cause a long-term increase or decrease in mean larval survival, which in this model leads to greater synchrony or extinction respectively. Spatially managed metapopulations of red sea urchins go extinct when distances between harvest refugia become greater than the scale of larval dispersal. All assessments of population dynamics indicate that metapopulation behavior in general dependes critically on the temporal and spatial nature of larval dispersal, which is largely determined by physical oceanographic conditions. We therfore explore physical influences on larval dispersal patterns. Observed trends in temperature and salinity applied to laboratory-determined responses indicate that natural variability in temperature and salinity can lead to variability in

  20. Influence of fermentation conditions on the surface properties and adhesion of Lactobacillus rhamnosus GG

    PubMed Central

    2012-01-01

    Background The surface properties of probiotic bacteria influence to a large extent their interactions within the gut ecosystem. There is limited amount of information on the effect of the production process on the surface properties of probiotic lactobacilli in relation to the mechanisms of their adhesion to the gastrointestinal mucosa. The aim of this work was to investigate the effect of the fermentation pH and temperature on the surface properties and adhesion ability to Caco-2 cells of the probiotic strain Lactobacillus rhamnosus GG. Results The cells were grown at pH 5, 5.5, 6 (temperature 37°C) and at pH 6.5 (temperature 25°C, 30°C and 37°C), and their surfaces analysed by X-ray photoelectron spectrometry (XPS), Fourier transform infrared spectroscopy (FT-IR) and gel-based proteomics. The results indicated that for all the fermentation conditions, with the exception of pH 5, a higher nitrogen to carbon ratio and a lower phosphate content was observed at the surface of the bacteria, which resulted in a lower surface hydrophobicity and reduced adhesion levels to Caco-2 cells as compared to the control fermentation (pH 6.5, 37°C). A number of adhesive proteins, which have been suggested in previous published works to take part in the adhesion of bacteria to the human gastrointestinal tract, were identified by proteomic analysis, with no significant differences between samples however. Conclusions The temperature and the pH of the fermentation influenced the surface composition, hydrophobicity and the levels of adhesion of L. rhamnosus GG to Caco-2 cells. It was deduced from the data that a protein rich surface reduced the adhesion ability of the cells. PMID:22931558

  1. Quantifying the local influence at a tall tower site in nocturnal conditions

    SciTech Connect

    Werth, David; Buckley, Robert; Zhang, Gengsheng; Kurzeja, Robert; Leclerc, Monique; Duarte, Henrique; Parker, Matthew; Watson, Thomas

    2015-10-17

    The influence of the local terrestrial environment on nocturnal atmospheric CO2 measurements at a 329-m television transmitter tower (and a component of a CO2 monitoring network) was estimated with a tracer release experiment and a subsequent simulation of the releases. This was done to characterize the vertical transport of emissions from the surface to the uppermost tower level and how it is affected by atmospheric stability. The tracer release experiment was conducted over two nights in May of 2009 near the Department of Energy’s Savannah River Site (SRS) in South Carolina. Tracer was released on two contrasting nights—slightly stable and moderately stable—from several upwind surface locations. Measurements at the 329-m level on both nights indicate that tracer was able to mix vertically within a relatively short (~24 km) distance, implying that nocturnal stable conditions do not necessarily prevent vertical dispersion in the boundary layer and that CO2 measurements at the tower are at least partly influenced by nearby emissions. A simulation of the tracer release is used to calculate the tower footprint on the two nights to estimate the degree to which the local domain affects the tower readings. The effect of the nocturnal boundary layer on the area sampled by the tower can be seen clearly, as the footprints were affected by changes in stability. The contribution of local sources to the measurements at the tower was minimal, however, suggesting that nocturnal concentrations at upper levels are contributed mostly by regional sources.

  2. Modeling the influence of varying hydraulic conditions on aerobic respiration and denitrification in the hyporheic zone

    NASA Astrophysics Data System (ADS)

    Trauth, N.; Schmidt, C.; Fleckenstein, J. H.

    2013-12-01

    Exchange of water and solutes across the stream-sediment interface is an important control for biogeochemical transformations in the hyporheic zone (HZ) with measurable impacts on nutrient cycling and solute attenuation in fluvial systems. Here we investigate the interplay between turbulent stream flow and HZ flow under various hydraulic conditions applied to two cases: a) three-dimensional generic pool-riffle sequences with different morphological properties, and b) a real mid-stream gravel-bar. Stream flow is simulated by the open source computational fluid dynamics (CFD) software OpenFOAM which provides the hydraulic head distribution at the streambed. It is sequentially coupled to the top of the groundwater model code MIN3P, simulating flow, solute transport, aerobic respiration (AR) and denitrification (DN) in the HZ. Flow in the HZ is directly influenced by the hydraulic head distribution at the streambed surface and the ambient groundwater flow. Three reactive transport scenarios are considered: 1) stream water as the primary source of dissolved oxygen (DO), nitrate (NO3) and dissolved organic carbon (DOC), 2) upwelling groundwater as an additionally source of NO3, and 3) upwelling groundwater as an additional source of DO in various concentrations. Results show an increase in hyporheic exchange flow for increasing stream discharge with a concurrent decrease in residence time. The fraction of circulating stream water through the HZ is in the range of 1x10-5 to 1x10-6 per unit stream length, decreasing with increasing discharge. Ambient groundwater flow in both the up- and downwelling direction diminishes significantly the hyporheic exchange flow and extent. Biogeochemical processes in the HZ are strongly controlled by ambient groundwater flow, even more so than by changes in stream discharge. AR and DN efficiencies of the HZ are significantly reduced by up- and downwelling groundwater and are positively correlated with median residence times. AR occurs in

  3. Meteorological conditions influencing the formation of level ice within the Baltic Sea

    NASA Astrophysics Data System (ADS)

    Mazur, A. K.; Krezel, A.

    2012-12-01

    short term changes in sea ice cover and meteorological conditions. In following studies we analyzed the formation of level sea ice depending on some weather conditions (temperature, humidity, pressure at sea level, 10 meter wind). It can be clearly seen that the most important factors influencing formation of level ice are the temperature and wind.

  4. A new parameterization of the UV irradiance altitude dependence for clear-sky conditions and its application in the on-line UV tool over Northern Eurasia

    NASA Astrophysics Data System (ADS)

    Chubarova, Nataly; Zhdanova, Yekaterina; Nezval, Yelena

    2016-09-01

    A new method for calculating the altitude UV dependence is proposed for different types of biologically active UV radiation (erythemally weighted, vitamin-D-weighted and cataract-weighted types). We show that for the specified groups of parameters the altitude UV amplification (AUV) can be presented as a composite of independent contributions of UV amplification from different factors within a wide range of their changes with mean uncertainty of 1 % and standard deviation of 3 % compared with the exact model simulations with the same input parameters. The parameterization takes into account for the altitude dependence of molecular number density, ozone content, aerosol and spatial surface albedo. We also provide generalized altitude dependencies of the parameters for evaluating the AUV. The resulting comparison of the altitude UV effects using the proposed method shows a good agreement with the accurate 8-stream DISORT model simulations with correlation coefficient r > 0.996. A satisfactory agreement was also obtained with the experimental UV data in mountain regions. Using this parameterization we analyzed the role of different geophysical parameters in UV variations with altitude. The decrease in molecular number density, especially at high altitudes, and the increase in surface albedo play the most significant role in the UV growth. Typical aerosol and ozone altitude UV effects do not exceed 10-20 %. Using the proposed parameterization implemented in the on-line UV tool (http://momsu.ru/uv/) for Northern Eurasia over the PEEX domain we analyzed the altitude UV increase and its possible effects on human health considering different skin types and various open body fraction for January and April conditions in the Alpine region.

  5. The influence of exogenous conditions on mobile measured gamma-ray spectrometry

    NASA Astrophysics Data System (ADS)

    Dierke, C.; Werban, U.; Dietrich, P.

    2012-12-01

    In the past, gamma ray measurements have been used for geological surveys and exploration using airborne and borehole logging systems. For these applications, the relationships between the measured physical parameter - the concentration of natural gamma emitters 40K, 238U and 232Th - and geological origin or sedimentary developments are well described. Based on these applications and knowledge in combination with adjusted sensor systems, gamma ray measurements are used to derive soil parameters to create detailed soil maps e.g., in digital soil mapping (DSM) and monitoring of soils. Therefore, not only qualitative but also quantitative comparability is necessary. Grain size distribution, type of clay minerals and organic matter content are soil parameters which directly influence the gamma ray emitter concentration. Additionally, the measured concentration is influenced by endogenous processes like soil moisture variation due to raining events, foggy weather conditions, or erosion and deposition of material. A time series of gamma ray measurements was used to observe changes in gamma ray concentration on a floodplain area in Central Germany. The study area is characterised by high variations in grain size distribution and occurrence of flooding events. For the survey, we used a 4l NaI(Tl) detector with GPS connection mounted on a sledge, which is towed across the field sites by a four-wheel-vehicle. The comparison of data from different time steps shows similar structures with minor variation between the data ranges and shape of structures. However, the data measured during different soil moisture contents differ in absolute value. An average increase of soil moisture of 36% leads to a decrease of Th (by 20%), K (by 29%), and U (by 41%). These differences can be explained by higher attenuation of radiation during higher soil moisture content. The different changes in nuclide concentration will also lead to varying ratios. We will present our experiences concerning

  6. Influence of environmental factors on the abundance of Anopheles farauti larvae in large brackish water streams in Northern Guadalcanal, Solomon Islands

    PubMed Central

    2011-01-01

    Background The main vector of malaria in Solomon Islands is Anopheles farauti, which has a mainly coastal distribution. In Northern Guadalcanal, Solomon Islands, high densities of An. farauti are supported by large brackish streams, which in the dry season are dammed by localized sand migration. The factors controlling the high larval productivity of these breeding sites have not been identified. Accordingly the influence of environmental factors on the presence and density of An. farauti larvae was assessed in three large naturally dammed streams. Methods Larval sites were mapped and anopheline larvae were collected monthly for 12 months (July 2007 to June 2008) from three streams using standard dippers. Larval collections were made from 10 locations spaced at 50 m intervals along the edge of each stream starting from the coast. At each collection point, floating filamentous algae, aquatic emergent plants, sun exposure, and salinity were measured. These environmental parameters along with rainfall were correlated with larval presence and density. Results The presence and abundance of An. farauti larvae varied between streams and was influenced by the month of collection, and distance from the ocean (p < 0.001). Larvae were more frequently present and more abundant within 50 m of the ocean during the dry season when the streams were dammed. The presence and density of larvae were positively associated with aquatic emergent plants (presence: p = 0.049; density: p = 0.001). Although filamentous algae did not influence the presence of larvae, this factor did significantly influence the density of larvae (p < 0.001). Rainfall for the month prior to sampling was negatively associated with both larval presence and abundance (p < 0.001), as high rainfall flushed larvae from the streams. Salinity significantly influenced both the presence (p = 0.002) and density (p = 0.014) of larvae, with larvae being most present and abundant in brackish water at < 10‰ seawater

  7. Geologic framework of the northern North Carolina, USA inner continental shelf and its influence on coastal evolution

    USGS Publications Warehouse

    Thieler, E. Robert; Foster, David S.; Himmelstoss, Emily A.; Mallinson, David J.

    2013-01-01

    The inner continental shelf off the northern Outer Banks of North Carolina was mapped using sidescan sonar, interferometric swath bathymetry, and high-resolution chirp and boomer subbottom profiling systems. We use this information to describe the shallow stratigraphy, reinterpret formation mechanisms of some shoal features, evaluate local relative sea-levels during the Late Pleistocene, and provide new constraints, via recent bedform evolution, on regional sediment transport patterns. The study area is approximately 290 km long by 11 km wide, extending from False Cape, Virginia to Cape Lookout, North Carolina, in water depths ranging from 6 to 34 m. Late Pleistocene sedimentary units comprise the shallow geologic framework of this region and determine both the morphology of the inner shelf and the distribution of sediment sources and sinks. We identify Pleistocene sedimentary units beneath Diamond Shoals that may have provided a geologic template for the location of modern Cape Hatteras and earlier paleo-capes during the Late Pleistocene. These units indicate shallow marine deposition 15–25 m below present sea-level. The uppermost Pleistocene unit may have been deposited as recently as Marine Isotope Stage 3, although some apparent ages for this timing may be suspect. Paleofluvial valleys incised during the Last Glacial Maximum traverse the inner shelf throughout the study area and dissect the Late Pleistocene units. Sediments deposited in the valleys record the Holocene transgression and provide insight into the evolutionary history of the barrier-estuary system in this region. The relationship between these valleys and adjacent shoal complexes suggests that the paleo-Roanoke River did not form the Albemarle Shelf Valley complex as previously proposed; a major fluvial system is absent and thus makes the formation of this feature enigmatic. Major shoal features in the study area show mobility at decadal to centennial timescales, including nearly a kilometer of

  8. Orographic and Climatic Influence on Leaf Wax Carbon and Hydrogen Isotopic Ratios: a Field Survey From Northern California

    NASA Astrophysics Data System (ADS)

    Tipple, B. J.; Pagani, M.; Smith, R.; Anders, A.

    2007-12-01

    The primary objective of this research was to empirically ground-truth environmental controls on δD and δ13C values of higher plant n-alkanes, since these higher-plant specific compounds are refractory and commonly preserved in the geologic record they hold great paleoclimatic and paleoenvironmental information. Our approach was to extensively sample leaves and stems of nine species of trees across two Northern California east-west transects twice during the growing season. One hundred and ninety trees from ninety-three sites were collected along with topsoils and surface waters from most localities. Bigleaf Maple ( Acer macrophyllum), California White Oak ( Quercus lobata) and Blue Oak ( Quercus douglasii) n--alkanes δ13C have been analyzed and range from -38.0 to -29.6‰, -35.2 to - 30.4‰ and -34.5 to -30.4‰, respectively. Currently, all tree species show little to no relationship with any physical variable, such as longitude, elevation, tree height, aspect, slope, etc. The large range in tree isotope values suggests these plants are reacting to a yet unknown climatic variable or these species operate within a range of water-use efficiencies. Similarly, soil-extracted n--alkane δ13C values range between -36.5 to -29.2‰ and do not strongly correlate with any physical parameter. Surface water δD and δ18O are highly correlated and similar to the meteoric water line, however, not as robust, soil-extracted n--alkane δD show similar trends. Notably, the apparent enrichment factor between soil lipids and surface waters is not as stable as seen in other localities, varying by over 30‰, illustrating uncertainties in paleo-applications. Interestingly, water δD and δ18O from surface waters varied little between early June and mid-September and demonstrate a roughly -90‰ depletion in deuterium across the two transects. This D-depletion is reflected in the early growing season stem waters with a consistent slope to that of surface waters.

  9. Mosses influence phosphorus cycling in rich fens by driving redox conditions in shallow soils.

    PubMed

    Crowley, Katherine F; Bedford, Barbara L

    2011-09-01

    Mosses play an integral role in the hydrologic regimes of ecosystems where they cover the soil surface, and thus affect biogeochemical cycling of elements influenced by soil oxidation-reduction (redox) reactions, including the plant growth-limiting nutrients, nitrogen and phosphorus (P). In rich fens where P often limits plant growth, we hypothesized that feedbacks between mosses and redox conditions would determine P availability to shallow-rooted forb species that constitute much of these wetlands' unusually high plant species diversity. In a moss removal experiment in three fens, forb tissue P and microbial P were greater while anion exchange membrane (AEM) resin P was lower where mosses occurred than where they were removed, suggesting both higher availability and greater demand for P in moss-covered soils. Coupled physicochemical and biological mechanisms drove moss effects on P cycling, ultimately through effects on soil oxygenation or reduction: higher redox potential underlying mosses corresponded to greater microbial activity, phosphatase enzyme activity, and colonization by arbuscular mycorrhizal fungi (AMF), all of which can promote greater P availability to plants. These more oxidized soils stimulated: (1) greater microbial activity and root vigor; (2) correspondingly greater P demand via microbial uptake, forb uptake, and iron (Fe)-P reactions; and (3) greater P supply through soil and root phosphatase activity and AMF colonization. This work demonstrates that mosses improve vascular plant P acquisition by alleviating stresses caused by reducing conditions that would otherwise prevail in shallow underlying soils, thus providing a mechanism by which mosses facilitate plant species diversity in rich fens.

  10. Influence of inlet boundary conditions on the local haemodynamics of intracranial aneurysms.

    PubMed

    Marzo, Alberto; Singh, Pankaj; Reymond, Philippe; Stergiopulos, Nikos; Patel, Umang; Hose, Rodney

    2009-08-01

    Haemodynamics is believed to play an important role in the initiation, growth and rupture of intracranial aneurysms. In this context, computational haemodynamics has been extensively used in an effort to establish correlations between flow variables and clinical outcome. It is common practice in the application of Dirichlet boundary conditions at domain inlets to specify transient velocities as either a flat (plug) profile or a spatially developed profile based on Womersley's analytical solution. This paper provides comparative haemodynamics measures for three typical cerebral aneurysms. Three dimentional rotational angiography images of aneurysms at three common locations, viz. basilar artery tip, internal carotid artery and middle cerebral artery were obtained. The computational tools being developed in the European project @neurIST were used to reconstruct the fluid domains and solve the unsteady Navier-Stokes equations, using in turn Womersley and plug-flow inlet velocity profiles. The effects of these assumptions were analysed and compared in terms of relevant haemodynamic variables within the aneurismal sac. For the aneurysm at the basilar tip geometries with different extensions of the afferent vasculature were considered to study the plausibility of a fully-developed axial flow at the inlet boundaries. The study shows that assumptions made on the velocity profile while specifying inlet boundary conditions have little influence on the local haemodynamics in the aneurysm, provided that a sufficient extension of the afferent vasculature is considered and that geometry is the primary determinant of the flow field within the aneurismal sac. For real geometries the Womersley profile is at best an unnecessary over-complication, and may even be worse than the plug profile in some anatomical locations (e.g. basilar confluence).

  11. Prediction of methotrexate CNS distribution in different species - influence of disease conditions.

    PubMed

    Westerhout, Joost; van den Berg, Dirk-Jan; Hartman, Robin; Danhof, Meindert; de Lange, Elizabeth C M

    2014-06-16

    Children and adults with malignant diseases have a high risk of prevalence of the tumor in the central nervous system (CNS). As prophylaxis treatment methotrexate is often given. In order to monitor methotrexate exposure in the CNS, cerebrospinal fluid (CSF) concentrations are often measured. However, the question is in how far we can rely on CSF concentrations of methotrexate as appropriate surrogate for brain target site concentrations, especially under disease conditions. In this study, we have investigated the spatial distribution of unbound methotrexate in healthy rat brain by parallel microdialysis, with or without inhibition of Mrp/Oat/Oatp-mediated active transport processes by a co-administration of probenecid. Specifically, we have focused on the relationship between brain extracellular fluid (brainECF) and CSF concentrations. The data were used to develop a systems-based pharmacokinetic (SBPK) brain distribution model for methotrexate. This model was subsequently applied on literature data on methotrexate brain distribution in other healthy and diseased rats (brainECF), healthy dogs (CSF) and diseased children (CSF) and adults (brainECF and CSF). Important differences between brainECF and CSF kinetics were found, but we have found that inhibition of Mrp/Oat/Oatp-mediated active transport processes does not significantly influence the relationship between brainECF and CSF fluid methotrexate concentrations. It is concluded that in parallel obtained data on unbound brainECF, CSF and plasma concentrations, under dynamic conditions, combined with advanced mathematical modeling is a most valid approach to develop SBPK models that allow for revealing the mechanisms underlying the relationship between brainECF and CSF concentrations in health and disease.

  12. Influence of microorganisms on the oxidation state distribution of multivalent actinides under anoxic conditions

    SciTech Connect

    Reed, Donald Timothy; Borkowski, Marian; Lucchini, Jean - Francois; Ams, David; Richmann, M. K.; Khaing, H.; Swanson, J. S.

    2010-12-10

    The fate and potential mobility of multivalent actinides in the subsurface is receiving increased attention as the DOE looks to cleanup the many legacy nuclear waste sites and associated subsurface contamination. Plutonium, uranium and neptunium are the near-surface multivalent contaminants of concern and are also key contaminants for the deep geologic disposal of nuclear waste. Their mobility is highly dependent on their redox distribution at their contamination source as well as along their potential migration pathways. This redox distribution is often controlled, especially in the near-surface where organic/inorganic contaminants often coexist, by the direct and indirect effects of microbial activity. Under anoxic conditions, indirect and direct bioreduction mechanisms exist that promote the prevalence of lower-valent species for multivalent actinides. Oxidation-state-specific biosorption is also an important consideration for long-term migration and can influence oxidation state distribution. Results of ongoing studies to explore and establish the oxidation-state specific interactions of soil bacteria (metal reducers and sulfate reducers) as well as halo-tolerant bacteria and Archaea for uranium, neptunium and plutonium will be presented. Enzymatic reduction is a key process in the bioreduction of plutonium and uranium, but co-enzymatic processes predominate in neptunium systems. Strong sorptive interactions can occur for most actinide oxidation states but are likely a factor in the stabilization of lower-valent species when more than one oxidation state can persist under anaerobic microbiologically-active conditions. These results for microbiologically active systems are interpreted in the context of their overall importance in defining the potential migration of multivalent actinides in the subsurface.

  13. Water quality, streamflow conditions, and annual flow-duration curves for streams of the San Juan–Chama Project, southern Colorado and northern New Mexico, 1935-2010

    USGS Publications Warehouse

    Falk, Sarah E.; Anderholm, Scott K.; Hafich, Katya A.

    2013-01-01

    The Albuquerque–Bernalillo County Water Utility Authority supplements the municipal water supply for the Albuquerque metropolitan area, in central New Mexico, with water diverted from the Rio Grande. Water diverted from the Rio Grande for municipal use is derived from the San Juan–Chama Project, which delivers water from streams in the southern San Juan Mountains in the Colorado River Basin in southern Colorado to the Rio Chama watershed and the Rio Grande Basin in northern New Mexico. The U.S. Geological Survey, in cooperation with Albuquerque–Bernalillo County Water Utility Authority, has compiled historical streamflow and water-quality data and collected new water-quality data to characterize the water quality and streamflow conditions and annual flow variability, as characterized by annual flow-duration curves, of streams of the San Juan–Chama Project. Nonparametric statistical methods were applied to calculate annual and monthly summary statistics of streamflow, trends in streamflow conditions were evaluated with the Mann–Kendall trend test, and annual variation in streamflow conditions was evaluated with annual flow-duration curves. The study area is located in northern New Mexico and southern Colorado and includes the Rio Blanco, Little Navajo River, and Navajo River, tributaries of the San Juan River in the Colorado River Basin located in the southern San Juan Mountains, and Willow Creek and Horse Lake Creek, tributaries of the Rio Chama in the Rio Grande Basin. The quality of water in the streams in the study area generally varied by watershed on the basis of the underlying geology and the volume and source of the streamflow. Water from the Rio Blanco and Little Navajo River watersheds, primarily underlain by volcanic deposits, volcaniclastic sediments and landslide deposits derived from these materials, was compositionally similar and had low specific-conductance values relative to the other streams in the study area. Water from the Navajo River

  14. The structural influence of family and parenting on young people's sexual and reproductive health in rural northern Tanzania

    PubMed Central

    Wamoyi, Joyce; Wight, Daniel; Remes, Pieter

    2015-01-01

    This paper explores the structural role of the family and parenting in young people's sexual and reproductive health. The study involved eight weeks of participant observation, 26 in-depth interviews, and 11 group discussions with young people aged 14–24 years, and 20 in-depth interviews and 6 group discussions with parents/carers of children in this age group. At an individual level, parenting and family structure were found to affect young people's sexual behaviour by influencing children's self-confidence and interactional competence, limiting discussion of sexual health and shaping economic provision for children, which in turn affected parental authority and daughters' engagement in risky sexual behaviour. Sexual norms are reproduced both through parents' explicit prohibitions and their own behaviours. Girls are socialised to accept men's superiority, which shapes their negotiation of sexual relationships. Interventions to improve young people's sexual and reproductive health should recognise the structural effects of parenting, both in terms of direct influences on children and the dynamics by which structural barriers such as gendered power relations and cultural norms around sexuality are transmitted across generations. PMID:25597368

  15. Influence of cue-conditioning on acquisition, maintenance and relapse of cocaine intravenous self-administration.

    PubMed

    Deroche-Gamonet, Véronique; Piat, Frédéric; Le Moal, Michel; Piazza, Pier Vincenzo

    2002-04-01

    Conditioning theories propose that, through a Pavlovian associative process, discrete stimuli acquire the ability to elicit neural states involved in the maintenance and relapse of a drug-taking behaviour. Experimental evidence indicates that drug-related cues play a role in relapse, however, their influence on the development and maintenance of drug self-administration has been poorly investigated. In this report, we analysed the effects of a drug-associated cue light on acquisition, maintenance and reinstatement of intravenous cocaine self-administration. The results show that a cocaine-associated cue light can act as an incentive in absence of the drug, but does not directly modify drug-reinforcing effects. Contingent and non-contingent presentations of a cocaine-associated cue light reinstated an extinguished self-administration behaviour. However, regardless of whether or not a cue light was associated with cocaine infusions, rats acquire cocaine intravenous self-administration reaching the same levels of intake. Furthermore, after self-administration has been acquired in presence of the cue light, the omission of the cue light or its non-contingent presentation did not modify rat behaviour. In conclusion, our work shows that cocaine-associated explicit cues do not directly interfere with the reinforcing effects of the drug.

  16. On the enduring and substantial influence of Carl Rogers' not-quite necessary nor sufficient conditions.

    PubMed

    Farber, Barry A

    2007-09-01

    Carl Rogers' 1957 paper (see record 2007-14639-002) is arguably the most successful of his many attempts to clarify and render testable the ideas behind client-centered therapy. While each of the conditions that Rogers postulated has been linked to positive therapeutic outcome, taken together they have never been conclusively proved (nor disproved) to be either necessary or sufficient for positive outcome. Nevertheless, the overriding "take-home" message in this classic paper--that the therapist's attitude and caring presence is critical for therapeutic success--is one that has had virtually unparalleled influence in every segment of the psychotherapeutic community. Clinical and theoretical innovations in the psychoanalytic community serve as examples of the following proposition: that Rogers' concepts, while accepted more than ever by a remarkably wide variety of psychotherapists, remain essentially unacknowledged as originating with him or in the tradition of humanistic and client-centered therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  17. Ferroelectric domain formation in discotic liquid crystals: Monte Carlo study on the influence of boundary conditions.

    PubMed

    Bose, Tushar Kanti; Saha, Jayashree

    2015-10-01

    The realization of a spontaneous macroscopic ferroelectric order in fluids of anisotropic mesogens is a topic of both fundamental and technological interest. Recently we demonstrated that a system of dipolar achiral disklike ellipsoids can exhibit long-searched ferroelectric liquid crystalline phases of dipolar origin. In the present work, extensive off-lattice Monte Carlo simulations are used to investigate the phase behavior of the system under the influences of the electrostatic boundary conditions that restrict any global polarization. We find that the system develops strongly ferroelectric slablike domains periodically arranged in an antiferroelectric fashion. Exploring the phase behavior at different dipole strengths, we find existence of the ferroelectric nematic and ferroelectric columnar order inside the domains. For higher dipole strengths, a biaxial phase is also obtained with a similar periodic array of ferroelectric slabs of antiparallel polarizations. We have studied the depolarizing effects by using both the Ewald summation and the spherical cutoff techniques. We present and compare the results of the two different approaches of considering the depolarizing effects in this anisotropic system. It is explicitly shown that the domain size increases with the system size as a result of considering a longer range of dipolar interactions. The system exhibits pronounced system size effects for stronger dipolar interactions. The results provide strong evidence to the novel understanding that the dipolar interactions are indeed sufficient to produce long-range ferroelectric order in anisotropic fluids.

  18. Influence of solvothermal synthesis conditions in BiSI nanostructures for application in ionizing radiation detectors

    NASA Astrophysics Data System (ADS)

    Aguiar, I.; Mombrú, M.; Pérez Barthaburu, M.; Bentos Pereira, H.; Fornaro, L.

    2016-02-01

    BiSI belongs to the A V B VI C VII chalcohalides group of compounds. These compounds show several interesting properties such as ferroelectricity, piezoelectricity along the c axis, and photoconductivity. Moreover, BiSI is a potential semiconductor material for room-temperature gamma and x-ray detection, given its band gap of 1.57 eV and its high density, 6.41 g cm-3. In this work we present BiSI nanostructures synthesized by the solvothermal method with the intention of using them for ionizing radiation detection. The solvent was varied to study its influence in morphology, particle size and size distribution. Three different conditions were tested, using either water, monoethylene glycol and a mixture of both solvents. Nanostructures were characterized by XRD to determine the phase obtained and reaction completeness; TEM was used to observe nanostructures morphology, size, size distribution and crystallinity; and finally FT-IR diffuse reflectance was used to study monoethylene glycol presence in the samples. Nanorods in the range of 100-200 nm width were obtained in all samples, but round nanoparticles of around 10 nm in diameter were also detected in samples synthesized only with monoethylene glycol. Samples synthesized in monoethylene glycol were used to fabricate pellets to construct detectors. The detectors responded to ionizing radiation and a resistivity in the order of 1013 Ω cm was estimated. This work proposes, to our knowledge, the first study of BiSI for its application in ionizing radiation detection.

  19. Influences of solution chemical conditions on mobilization of TNT from contaminated soil

    SciTech Connect

    Dante, D.A.; Tiller, C.L.; Pennell, K.D.

    1996-12-31

    Residual explosives and their byproducts are common contaminants at several US military installations. One of the major explosive contaminants is 2,4,6-Trinitrotoluene (TNT) (a hydrophobic organic compound). Contamination from TNT has resulted from manufacturing and handling processes which occurred at military installations, especially Army Ammunition Plants (AAP), over many decades until environmental regulations were implemented. TNT causes adverse effects to the environment, including growth inhibition to plants, toxicity to aquatic life, and possible mutagenicity, and also is toxic to humans. As a result of the effects of TNT on the environment and current environmental regulations, substantial research effort has been focused on determining the fate of TNT in natural systems and the development of remediation processes. Many potential remediation processes, such as those involving plants or microorganisms, are in part limited by the transfer of TNT from solid phases (e.g., sorbed to soil or present as TNT granules) to the aqueous phase. The purpose of this research is to assess the release of TNT from a soil phase to a mobile aqueous phase under varying solution chemical conditions. In particular, influences of pH, aquatic natural organic matter, and surfactants are investigated.

  20. The Influence of Safety, Efficacy, and Medical Condition Severity on Natural versus Synthetic Drug Preference.

    PubMed

    Meier, Brian P; Lappas, Courtney M

    2016-11-01

    Research indicates that there is a preference for natural v. synthetic products, but the influence of this preference on drug choice in the medical domain is largely unknown. We present 5 studies in which participants were asked to consider a hypothetical situation in which they had a medical issue requiring pharmacological therapy. Participants ( N = 1223) were asked to select a natural, plant-derived, or synthetic drug. In studies 1a and 1b, approximately 79% of participants selected the natural v. synthetic drug, even though the safety and efficacy of the drugs were identical. Furthermore, participants rated the natural drug as safer than the synthetic drug, and as that difference increased, the odds of choosing the natural over synthetic drug increased. In studies 2 and 3, approximately 20% of participants selected the natural drug even when they were informed that it was less safe (study 2) or less effective (study 3) than the synthetic drug. Finally, in study 4, approximately 65% of participants chose a natural over synthetic drug regardless of the severity of a specific medical condition (mild v. severe hypertension), and this choice was predicted by perceived safety and efficacy differences. Overall, these data indicate that there is a bias for natural over synthetic drugs. This bias could have implications for drug choice and usage. PMID:26683247

  1. Influence of impact conditions on plasma generation during hypervelocity impact by aluminum projectile

    NASA Astrophysics Data System (ADS)

    Song, Weidong; Lv, Yangtao; Li, Jianqiao; Wang, Cheng; Ning, Jianguo

    2016-07-01

    For describing hypervelocity impact (relative low-speed as related to space debris and much lower than travelling speed of meteoroids) phenomenon associated with plasma generation, a self-developed 3D code was advanced to numerically simulate projectiles impacting on a rigid wall. The numerical results were combined with a new ionization model which was developed in an early study to calculate the ionized materials during the impact. The calculated results of ionization were compared with the empirical formulas concluded by experiments in references and a good agreement was obtained. Then based on the reliable 3D numerical code, a series of impacts with different projectile configurations were simulated to investigate the influence of impact conditions on hypervelocity impact generated plasma. It was found that the form of empirical formula needed to be modified. A new empirical formula with a critical impact velocity was advanced to describe the velocity dependence of plasma generation and the parameters of the modified formula were ensured by the comparison between the numerical predictions and the empirical formulas. For different projectile configurations, the changes of plasma charges with time are different but the integrals of charges on time almost stayed in the same level.

  2. The influence of target irradiation conditions on the parameters of laser-produced plasma jets

    NASA Astrophysics Data System (ADS)

    Kasperczuk, A.; Pisarczyk, T.; Borodziuk, S.; Ullschmied, J.; Krousky, E.; Masek, K.; Pfeifer, M.; Rohlena, K.; Skala, J.; Pisarczyk, P.

    2007-03-01

    Recent experimental results demonstrate that the forming of plasma jets is a fundamental process accompanying the laser-produced plasma expansion, if a massive planar target with relatively high atomic number is irradiated by a defocused laser beam. In this paper some new results on the influence of target irradiation conditions on plasma jet parameters are presented. The experiment was carried out at the Prague Asterix Laser System (PALS) iodine laser [K. Jungwirth, A. Cejnarova, L. Juha, B. Kralikova, J. Krasa, E. Krousky, P. Krupickova, L. Laska, K. Masek, A. Prag, O. Renner, K. Rohlena, B. Rus, J. Skala, P. Straka, and J. Ullschmied, Phys. Plasmas 8, 2495 (2001)]. with the third harmonic beam of the pulse duration of 250ps. The beam energies varied in the range of 13-160J. The planar massive targets used in the experiment were made of copper. For measurements of the electron density evolution a three frame interferometric system was employed. The jets were produced in the whole range of the laser energy used. Calculations of the efficiency of the plasma jet production show that it decreases with increasing the laser energy.

  3. The influence of target irradiation conditions on the parameters of laser-produced plasma jets

    SciTech Connect

    Kasperczuk, A.; Pisarczyk, T.; Borodziuk, S.; Ullschmied, J.; Krousky, E.; Masek, K.; Pfeifer, M.; Rohlena, K.; Skala, J.; Pisarczyk, P.

    2007-03-15

    Recent experimental results demonstrate that the forming of plasma jets is a fundamental process accompanying the laser-produced plasma expansion, if a massive planar target with relatively high atomic number is irradiated by a defocused laser beam. In this paper some new results on the influence of target irradiation conditions on plasma jet parameters are presented. The experiment was carried out at the Prague Asterix Laser System (PALS) iodine laser [K. Jungwirth, A. Cejnarova, L. Juha, B. Kralikova, J. Krasa, E. Krousky, P. Krupickova, L. Laska, K. Masek, A. Prag, O. Renner, K. Rohlena, B. Rus, J. Skala, P. Straka, and J. Ullschmied, Phys. Plasmas 8, 2495 (2001)]. with the third harmonic beam of the pulse duration of 250 ps. The beam energies varied in the range of 13-160 J. The planar massive targets used in the experiment were made of copper. For measurements of the electron density evolution a three frame interferometric system was employed. The jets were produced in the whole range of the laser energy used. Calculations of the efficiency of the plasma jet production show that it decreases with increasing the laser energy.

  4. The influence of temperature on limestone sulfation and attrition under fluidized bed combustion conditions

    SciTech Connect

    Montagnaro, Fabio; Salatino, Piero; Scala, Fabrizio

    2010-04-15

    The influence of temperature on attrition of two limestones during desulfurization in a fluidized bed reactor was investigated. Differences in the microstructure of the two limestones were reflected by a different thickness of the sulfate shell formed upon sulfation and by a different value of the ultimate calcium conversion degree. Particle attrition and fragmentation were fairly small under moderately bubbling fluidization conditions for both limestones. An increase of temperature from 850 C to 900 C led to an increase of the attrition rate, most likely because of a particle weakening effect caused by a faster CO{sub 2} evolution during calcination. This weakening effect, however, was not sufficiently strong to enhance particle fragmentation in the bed. The progress of sulfation, associated to the build-up of a hard sulfate shell around the particles, led in any case to a decrease of the extent of attrition. Sulfation at 900 C was less effective than at 850 C, and this was shown to be related to the porosimetric features of the different samples. (author)

  5. Influence of thermal processing conditions on acrylamide generation and browning in a potato model system.

    PubMed

    Amrein, Thomas M; Limacher, Anita; Conde-Petit, Béatrice; Amado, Renato; Escher, Felix

    2006-08-01

    Fried potato products such as French fries and chips may contain substantial amounts of acrylamide. Numerous efforts are undertaken to minimize the acrylamide content of these products while sensory properties such as color and flavor have to be respected as well. An optimization of the frying process can be achieved if the basic kinetic data of the browning and acrylamide formation are known. Therefore, heating experiments with potato powder were performed under controlled conditions (moisture, temperature, and time). Browning and acrylamide content both increased with heating time at all temperatures and moisture contents tested. The moisture content had a strong influence on the activation energy of browning and acrylamide formation. The activation energy strongly increased at moisture contents below 20%. At higher moisture contents, it was very similar for both parameters. At low moisture contents, the activation energy of acrylamide formation was larger as compared to the one for browning. This explains why the end of the frying process is very critical. Therefore, a lower temperature toward the end of frying reduces the acrylamide content of the product while color development is still good.

  6. The influence of different hydroponic conditions on thorium uptake by Brassica juncea var. foliosa.

    PubMed

    Wang, Dingna; Zhou, Sai; Liu, Li; Du, Liang; Wang, Jianmei; Huang, Zhenling; Ma, Lijian; Ding, Songdong; Zhang, Dong; Wang, Ruibing; Jin, Yongdong; Xia, Chuanqin

    2015-05-01

    The effects of different hydroponic conditions (such as concentration of thorium (Th), pH, carbonate, phosphate, organic acids, and cations) on thorium uptake by Brassica juncea var. foliosa were evaluated. The results showed that acidic cultivation solutions enhanced thorium accumulation in the plants. Phosphate and carbonate inhibited thorium accumulation in plants, possibly due to the formation of Th(HPO4)(2+), Th(HPO4)2, or Th(OH)3CO3 (-) with Th(4+), which was disadvantageous for thorium uptake in the plants. Organic aids (citric acid, oxalic acid, lactic acid) inhibited thorium accumulation in roots and increased thorium content in the shoots, which suggested that the thorium-organic complexes did not remain in the roots and were beneficial for thorium transfer from the roots to the shoots. Among three cations (such as calcium ion (Ca(2+)), ferrous ion (Fe(2+)), and zinc ion (Zn(2+))) in hydroponic media, Zn(2+) had no significant influence on thorium accumulation in the roots, Fe(2+) inhibited thorium accumulation in the roots, and Ca(2+) was found to facilitate thorium accumulation in the roots to a certain extent. This research will help to further understand the mechanism of thorium uptake in plants.

  7. Influence of thermal processing conditions on acrylamide generation and browning in a potato model system.

    PubMed

    Amrein, Thomas M; Limacher, Anita; Conde-Petit, Béatrice; Amado, Renato; Escher, Felix

    2006-08-01

    Fried potato products such as French fries and chips may contain substantial amounts of acrylamide. Numerous efforts are undertaken to minimize the acrylamide content of these products while sensory properties such as color and flavor have to be respected as well. An optimization of the frying process can be achieved if the basic kinetic data of the browning and acrylamide formation are known. Therefore, heating experiments with potato powder were performed under controlled conditions (moisture, temperature, and time). Browning and acrylamide content both increased with heating time at all temperatures and moisture contents tested. The moisture content had a strong influence on the activation energy of browning and acrylamide formation. The activation energy strongly increased at moisture contents below 20%. At higher moisture contents, it was very similar for both parameters. At low moisture contents, the activation energy of acrylamide formation was larger as compared to the one for browning. This explains why the end of the frying process is very critical. Therefore, a lower temperature toward the end of frying reduces the acrylamide content of the product while color development is still good. PMID:16881694

  8. Influence of Sedimentary Bedding on Reactive Transport Parameters under Unsaturated Conditions

    SciTech Connect

    Mayes, Melanie; Tang, Guoping; Jardine, Philip M; McKay, Larry Donald; Yin, Xiangping Lisa; Pace, M. N.; Parker, Jack C; Zhang, Fan; Mehlhorn, Tonia L; Dansby-Sparks, Royce N

    2009-01-01

    Moisture and contaminant transport in partially saturated, heterogeneous, layered sediments is typically anisotropic. Solute transport parameters, including dispersivity and the adsorption coefficient, and the modeled concentration of reactive minerals may depend on the direction of flow with respect to sedimentary layering. Reaction rates, in contrast, should be independent of flow direction. We determined the influence of flow direction on transport parameters for nonreactive (Br{sup -}) and reactive (cobalt ethylenediaminetetraacetic acid [Co(II)EDTA{sup 2-}]) solutes under partially saturated conditions by imposing flow either parallel to or across sedimentary bedding in 11 intact sediment cores of various textures. Higher dispersivity of nonreactive tracers in parallel-bed cores suggested fluid channeling through permeable layers, while low-conductivity layers dampened channeling in cross-bed samples. Rates of transformation of Co(II)EDTA{sup 2-} into Co(III)EDTA{sup -} and of disassociation of Co{sup 2+} and EDTA{sup 4-} were modeled assuming that the reaction rates were independent of the flow direction. The concentration of Mn oxides that was responsible for the transformation reaction was dependent on the flow direction, which governed the extent of contact between the solution and the solid phase. Similarly, the adsorption constants of Co(II)EDTA{sup 2-} and Co(III)EDTA{sup -} were dependent on the flow direction but were also unique for each experiment. The modeled concentration of reactive minerals was the most sensitive parameter describing the reaction and transformation of Co(II)EDTA{sup 2-}.

  9. Influence of indoor air conditions on radon concentration in a detached house.

    PubMed

    Akbari, Keramatollah; Mahmoudi, Jafar; Ghanbari, Mahdi

    2013-02-01

    Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cancer. Indoor air conditions and ventilation systems strongly influence indoor radon concentrations. This paper focuses on effects of air change rate, indoor temperature and relative humidity on indoor radon concentrations in a one family detached house in Stockholm, Sweden. In this study a heat recovery ventilation system unit was used to control the ventilation rate and a continuous radon monitor (CRM) was used to measure radon levels. FLUENT, a computational fluid dynamics (CFD) software package was used to simulate radon entry into the building and air change rate, indoor temperature and relative humidity effects using a numerical approach. The results from analytical solution, measurements and numerical simulations showed that air change rate, indoor temperature and moisture had significant effects on indoor radon concentration. Increasing air change rate reduces radon level and for a specific air change rate (in this work Ach = 0.5) there was a range of temperature and relative humidity that minimized radon levels. In this case study minimum radon levels were obtained at temperatures between 20 and 22 °C and a relative humidity of 50-60%.

  10. Influence of indoor air conditions on radon concentration in a detached house.

    PubMed

    Akbari, Keramatollah; Mahmoudi, Jafar; Ghanbari, Mahdi

    2013-02-01

    Radon is released from soil and building materials and can accumulate in residential buildings. Breathing radon and radon progeny for extended periods hazardous to health and can lead to lung cancer. Indoor air conditions and ventilation systems strongly influence indoor radon concentrations. This paper focuses on effects of air change rate, indoor temperature and relative humidity on indoor radon concentrations in a one family detached house in Stockholm, Sweden. In this study a heat recovery ventilation system unit was used to control the ventilation rate and a continuous radon monitor (CRM) was used to measure radon levels. FLUENT, a computational fluid dynamics (CFD) software package was used to simulate radon entry into the building and air change rate, indoor temperature and relative humidity effects using a numerical approach. The results from analytical solution, measurements and numerical simulations showed that air change rate, indoor temperature and moisture had significant effects on indoor radon concentration. Increasing air change rate reduces radon level and for a specific air change rate (in this work Ach = 0.5) there was a range of temperature and relative humidity that minimized radon levels. In this case study minimum radon levels were obtained at temperatures between 20 and 22 °C and a relative humidity of 50-60%. PMID:23159846

  11. Influence of low concentrations of an acid preservative on sponge cakes under different storage conditions.

    PubMed

    de la Rosa, P; Jordano, R; Medina, L M

    2009-03-01

    In a previous study, we demonstrated the efficiency of an acid test preservative at concentrations higher than 10 g/kg of product. The aim of the current study has been to assay, in a pilot plant, a preservative at lower and different doses than tested in the aforementioned study, in contrast with different storage temperature and relative humidity (RH) conditions and to check the possibilities of the growth of molds with a toxigenic capacity. The effect of the test preservative is not demonstrable at very low concentrations, as occurs in batch 2. In this case, the influence of the other storage parameters, temperature and RH, has a mixed effect, which makes it difficult to draw conclusions about the convenience of the preservative. In our opinion, the minimal concentration of the test preservative to reach readable results is 4 g/kg, but it is not enough to guarantee a longer shelf life. Regarding the mycotoxigenic study, the majority of molds obtained in the isolations from the cakes after their macroscopic identification corresponded to the genera Aspergillus and Penicillium. Only 5 turned out to be mycotoxigenic, with citrinin and viridicatumtoxin being detected.

  12. Influence of different treatment condition on biopolymer yield production for coagulation-flocculation process

    NASA Astrophysics Data System (ADS)

    Aisyah, I. S.; Murshed, M. F.; Norli, I.

    2016-06-01

    Two different agro wastes (banana pseudostem and rice straw) were utilized in order to extract biopolymer (pectin) known as coagulant aid in water and wastewater treatment. Factors such as pH, temperature and time were chosen due to the critical role in hot acid extraction process. The yield of biopolymer extraction from banana pseudostem was found to be higher at 28% meanwhile only 18% from rice straw was manage to produce from the dry weight 10 g, respectively. It was found that extraction temperature and extraction time were the most important factors influencing the biopolymer yield which increased with temperature and time or decreasing pH. Based on two level factorial design, the same condition of pH 1.5, temperature 90 oC and 4 hours extraction time can produce high amount of extracted biopolymer. Fourier Transform Infrared Spectroscopy (FTIR) was used to detect the existence of functional group which helps in the coagulation-flocculation process. Result indicates a similar functional group of biopolymer were detected for both difference agro wastes.

  13. On the enduring and substantial influence of Carl Rogers' not-quite necessary nor sufficient conditions.

    PubMed

    Farber, Barry A

    2007-09-01

    Carl Rogers' 1957 paper (see record 2007-14639-002) is arguably the most successful of his many attempts to clarify and render testable the ideas behind client-centered therapy. While each of the conditions that Rogers postulated has been linked to positive therapeutic outcome, taken together they have never been conclusively proved (nor disproved) to be either necessary or sufficient for positive outcome. Nevertheless, the overriding "take-home" message in this classic paper--that the therapist's attitude and caring presence is critical for therapeutic success--is one that has had virtually unparalleled influence in every segment of the psychotherapeutic community. Clinical and theoretical innovations in the psychoanalytic community serve as examples of the following proposition: that Rogers' concepts, while accepted more than ever by a remarkably wide variety of psychotherapists, remain essentially unacknowledged as originating with him or in the tradition of humanistic and client-centered therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved). PMID:22122255

  14. Influence of Aerosol Chemical Composition on Heterogeneous Ice Formation under Mid-Upper Troposphere Conditions

    NASA Astrophysics Data System (ADS)

    Kanji, Z. A.; Niemand, M.; Saathoff, H.; Möhler, O.; Chou, C.; Abbatt, J.; Stetzer, O.

    2011-12-01

    Aerosols are involved in cooling/warming the atmosphere directly via interaction with incoming solar radiation (aerosol direct effect), or via their ability to act as cloud condensation or ice nuclei (IN) and thus play a role in cloud formation (indirect effect). In particular, the physical properties of aerosols such as size and solubility and chemical composition can influence their behavior and fate in the atmosphere. Ice nucleation taking place via IN is termed as heterogeneous ice nucleation and can take place with via deposition (ice forming on IN directly from the vapor phase), condensation/immersion (freezing via formation of the liquid phase on IN) or condensation (IN colliding with supercooled liquid drops). This presentation shows how the chemical composition and surface area of various tropospherically relevant aerosols influence conditions of temperature (T) and relative humidity (RH) required for heterogeneous ice formation conditions in the mid-upper troposphere regime (253 - 220K)? Motivation for this comes first from, the importance of being able to predict ice formation accurately so as to understand the hydrological cycle since the ice is the primary initiator of precipitation forming clouds. Second, the tropospheric budget of water vapour, an especially active greenhouse gas is strongly influenced by ice nucleation and growth. Third, ice surfaces in the atmosphere act as heterogeneous surfaces for chemical reactions of trace gases (e.g., SO2, O3, NOx and therefore being able to accurately estimate ice formation rates and quantify ice surface concentrations will allow a more accurate calculation of trace gas budgets in the troposphere. Ice nucleation measurements were conducted using a self-developed continuous flow diffusion chamber and static chamber. A number of tropospherically relevant particulates with naturally-varying and laboratory-modified surface chemistry/structure were investigated for their ice formation efficiency based on highest

  15. Chronic stress, cyclic 17β-estradiol, and daily handling influences on fear conditioning in the female rat.

    PubMed

    Hoffman, Ann N; Armstrong, Charles E; Hanna, Jeffery J; Conrad, Cheryl D

    2010-10-01

    Chronic stress and estrogens alter many forebrain regions in female rats that affect cognition. In order to investigate how chronic stress and estrogens influence fear learning and memory, we ovariectomized (OVX) female Sprague-Dawley rats and repeatedly injected them (s.c.) with 17β-estradiol (E, 10 μg/250 g or sesame oil vehicle, VEH). Concurrently, rats were restrained for 6 h/d/21 d (STR) or left undisturbed (CON). Rats were then fear conditioned with 4 tone-footshock pairings and then after 1 h and 24 h delays, given 15 tone extinction trials. Regardless of E treatment, chronic stress (VEH, E) facilitated freezing to tone during acquisition and extinction following a 1h delay, but not during extinction after a 24 h delay. E did not influence freezing to tone during any phase of fear conditioning for either the control or chronically stressed rats, but did influence contextual conditioning that may have been carried predominately by the STR group. In the second experiment, we investigated "handling" influences on fear conditioning acquisition, given the disparate findings from the current study and previous work (Baran, Armstrong, Niren, & Conrad, 2010; Baran, Armstrong, Niren, Hanna, & Conrad, 2009). Female rats remained gonadally-intact since E did not influence tone fear conditioning. Indeed, brief daily handling (1-3 m/d/21 d) facilitated acquisition of fear conditioning in chronically stressed female rats, and either had no effect or slightly attenuated fear conditioning in controls. Thus, chronic stress impacts amygdala-mediated fear learning in both OVX- and gonadally-intact females as found previously in males, with handling significantly influencing these outcomes.

  16. Influence of Vegetation and Management Conditions of Forest Cathcments on Their Runoff Characteristics

    NASA Astrophysics Data System (ADS)

    Chikamori, H.

    2007-12-01

    There is rising concern that devastation of planted conifer forests due to poor management might change runoff characteristics and provoke severer flood disasters in Japan. Planted conifer forests in Japan were planted from 1960s to 1970s as a countermeasure to building materials shortage. Domestic forestry products, however, lost out in the price competition with imported products after 1970s, so that forestry has stagnated in Japan, which causes the shortage of forestry workers to maintain planted forests. In this study, runoff variations for the same rainfall pattern observed at neighboring catchments with different conditions were compared so that influence of vegetation and management conditions of forest cathcments on their runoff characteristics was examined. Besides, a Long-and-Short Term (LST) model was calibrated for each of the objective catchments to know the difference in hydrological components as surface flow, subsurface flow, groundwater flow, infiltration and percolation. In three observation sites, eleven catchments were selected as objectives. The areas of the catchments vary from 0.17 to 36 ha. First, runoff characteristics between conifer and broadleaf forests was compared. The result clearly showed that total runoff depth and peak runoff for storm events were both larger in conifer forests than in the broadleaf catchments, and that total infiltration was smaller in conifer than in broadleaf catchments. The result supports the fact that natural forests are generally considered to have functions of water retention and flood control. Second, runoff characteristics between well and poorly managed planted conifer forests was compared. The result, however, did not show the clear difference. It was difficult to find correlation between forest management condition of catchments and total amount of each hydrological process during some storm events, so that the existence of forest management impact on runoff characteristics could not be identified only

  17. Large eddy simulation of the influence of CCN and thermodynamic conditions on marine stratocumulus cloud development

    NASA Astrophysics Data System (ADS)

    Song, K.; Yum, S. S.

    2009-09-01

    The marine stratocumulus topped boundary layer, which prevails in the subtropical oceanic regions where the subsidence inversion associated with the descending branch of the Hadley-Walker cell dominates, is thought to be an important component of the climate system. High albedo (30-40%) of stratocumulus clouds compared to the ocean background (10%) gives rise to large deficits in the absorbed solar radiation flux. Since cloud radiative properties are highly dependent on cloud microphysical properties, which are in turn dependent on the cloud condensation nuclei (CCN) distribution, understanding the influence of anthropogenic CCN on cloud microphysics and dynamics is a key to accurately assess the climatic impact of marine stratocumulus clouds. A large eddy simulation (LES) model is good for studying stratocumulus clouds in the boundary layer because it explicitly resolves turbulent scale eddies and can provide information on detailed microphysical structure that is difficult to be measured over the ocean. We employ the CIMMS (Cooperative Institute for Mesoscale Meteorological Studies, University of Oklahoma) 3D LES model with explicit bin microphysics. We examine the microphysical and dynamical evolution of stratocumulus clouds under different CCN loadings for four different thermodynamic conditions (the key differences are in moisture content and temperature inversion height). Contrasting results of daytime and nocturnal simulations are also examined. Three different measured CCN spectra that represent maritime, continental, and polluted air masses are used as input CCN spectra for the model; the concentrations at 1% supersaturation are 163, 1023, and 5292 cm-3, respectively. The grid spacing is 75 m in the horizontal and 25 m in the vertical, to make the total domain size of 3×3×1.25 km. Total simulation time is 6 hrs. The large-scale subsidence is prescribed by w= -Dz, where the large-scale divergence D = 5×10-6 s-1 is assumed. For the clouds formed under

  18. Joint influence of the Indo-Pacific Warm Pool and Northern Arabian Sea Temperatures on the Indian Summer Monsoon in a Global Climate Model Simulation

    NASA Astrophysics Data System (ADS)

    Befort, Daniel J.; Leckebusch, Gregor C.; Cubasch, Ulrich

    2016-04-01

    Proxy-based studies confirmed that the Indian Summer Monsoon (ISM) shows large variations during the Holocene. These changes might be explained by changes in orbital conditions and solar insolation but are also thought to be associated to changes in oceanic conditions, e.g. over the Indo-Pacific-Warm-Pool region. However, due to the nature of these (proxy-based) analyses no conclusion about atmospheric circulation changes during dry and wet epochs are possible. Here, a fully-coupled global climate simulation (AOGCM) covering the past 6000 years is analysed regarding ISM variability. Several dry and wet epochs are found, the most striking around 2ka BP (dry) and 1.7ka BP (wet). As only orbital parameters change during integration, we expect these "shorter-term" changes to be associated with changes in oceanic conditions. During 1.7ka BP the sea surface temperatures (SST) over the Northern Arabian Sea (NARAB) are significantly warmer compared to 2ka BP, whereas cooler conditions are found over the western Pacific Ocean. Additionally, significant differences are found over large parts of the North Atlantic. To explain in how far these different ocean basins are responsible for anomalous conditions during 1.7ka BP, several sensitivity experiments with changed SST/SIC conditions are carried out. It is found that neither the SST's in the Pacific nor in the Indian Ocean are able to reproduce the anomalous rainfall and atmospheric circulation patterns during 1.7ka on its own. Instead, anomalous dry conditions during 2ka BP and wet conditions during 1.7ka BP are associated with a shift of the Indo-Pacific-Warm-Pool (IPWP) and simultaneous anomalous sea-surface temperatures over the NARAB region. Eventually, it is tested in how far this hypothesis holds true for other dry and wet events in the AOGCM data during the whole 6000 years. In general, a shift of the IPWP without anomalous SST conditions over the NARAB region (and vice versa) is not sufficient to cause long

  19. Investigation of the Offshore Section of the Northern San Andreas Fault: Slip Partitioning, Shallow Deformation, and Fault Trend Influence

    NASA Astrophysics Data System (ADS)

    Beeson, J. W.; Goldfinger, C.; Johnson, S. Y.

    2012-12-01

    Geodetic studies have shown that the angular velocities between the Pacific Sierra Nevada/Great Valley block are roughly 39 mm/yr and that the Northern San Andreas Fault (NSAF), at Pt. Arena, CA, accommodates roughly 25 mm/yr of that motion. The remaining motion is thought to be accommodated by slip on the Maacamma fault zone and the Bartlett Springs fault zone to the east of the NSAF. Since the NSAF moves offshore north of Point Arena, CA, the use of geodetic techniques to evaluate slip rates on roughly 120 km of the NSAF is challenging. We now have a detailed fault location map from Pt. Arena to Pt. Delgada, CA which allows us to evaluate, qualitatively at present, strain partitioning along this section of the plate boundary. The NSAF is mapped with multibeam bathymetry and ~100 seismic reflection profiles. The fault moves offshore north of Pt. Arena and returns onshore at Pt. Delgada. The entire offshore section of the NSAF can be characterized by a narrow, ~1 km wide deformation zone. Utilizing bathymetric and seismic data we infer that the NSAF loses slip northward based primarily on the presence of numerous northwest-trending splay faults and compressional folds. These splay faults, which are visible for ~10 km away from the NSAF and are steeply dipping, appear to be active and accommodating a proportion of the strike slip motion. These splay faults appear to dive below the penetrating depth of the mini-sparker leaving folded strata above them. They also appear to have recent deformation on the seafloor expressed as uplift and generally trend to the NW with apparent reverse and strike slip motion. Incorporating industry released multi-channel seismic reflection profiles we have also mapped and evaluated other large compressional structures to the west on the Viscano block. A sharp bend of the NSAF, ~9 degrees to the north, is mapped near the submarine Noyo Canyon Head. This right bend in a right lateral strike-slip fault has created a small asymmetric basin

  20. Carbon cycling in extratropical terrestrial ecosystems of the Northern Hemisphere during the 20th century: A modeling analysis of the influences of soil thermal dynamics

    USGS Publications Warehouse

    Zhuang, Q.; McGuire, A.D.; Melillo, J.M.; Clein, J.S.; Dargaville, R.J.; Kicklighter, D.W.; Myneni, R.B.; Dong, J.; Romanovsky, V.E.; Harden, J.; Hobbie, J.E.

    2003-01-01

    1990s was enhanced by an additional 0.35 Pg C yr-1 in extratropical terrestrial ecosystems, with most of the additional storage in northern Eurasia. The carbon storage simulated by TEM 5.0 in the 1980s and 1990s was lower than estimates based on other methodologies, including estimates by atmospheric inversion models and remote sensing and inventory analyses. This suggests that other issues besides the role of soil thermal dynamics may be responsible, in part, for the temporal and spatial dynamics of carbon storage of extratropical terrestrial ecosystems. In conclusion, the consideration of soil thermal dynamics and terrestrial cryospheric processes in modeling the global carbon cycle has helped to reduce biases in the simulation of the seasonality of carbon dynamics of extratropical terrestrial ecosystems. This progress should lead to an enhanced ability to clarify the role of other issues that influence carbon dynamics in terrestrial regions that experience seasonal freezing and thawing of soil.

  1. Northern Ireland.

    PubMed

    1998-01-01

    The anti-choice lobby has expressed concern that the government may consider reviewing or reforming abortion law in Northern Ireland. The legal status of abortion is similar to that in Britain before the introduction of the 1967 Abortion Act. However, the commemoration of the 30th anniversary of abortion law reform in Britain presents an opportunity to discuss the benefits of such change in Northern Ireland. Such discussion may cause ministers to reconsider the status of abortion. Anticipating possible discussion, some anti-choice Northern Ireland Members of Parliament tabled Early Day Motion (EDM) 352 "Northern Ireland and the Abortion Act," opposing the introduction of abortion services into Northern Ireland. Member of Parliament Harry Barnes tabled an amendment to the motion noting that current abortion law in Northern Ireland violates the standards of international human rights law and that about 2000 women travel from Northern Ireland annually for abortions. EDM 352 has been signed by 17 Members of Parliament; the amendment, by 13. PMID:12321442

  2. Sources of Below-Ground Respired Carbon in a Northern Minnesota Ombrotrophic Spruce Bog and the Influence of Heating Manipulations.

    NASA Astrophysics Data System (ADS)

    Guilderson, T. P.; McFarlane, K. J.; McNicol, G.; Hanson, P. J.; Chanton, J.; Wilson, R.; Bosworth, R.; Singleton, M. J.

    2015-12-01

    A significant uncertainty in future land-surface carbon budgets is the response of wetlands to climate change. A related question is the future net climate (radiative) forcing impact due to ecosystem and environmental change in wetlands. Active wetlands emit both CO2 and CH4 to the atmosphere. CH4 is, over a few decades, a much more potent greenhouse gas than CO2 whereas as a consequence of a much longer atmospheric lifetime, CO2 has a longer 'tail' to its influence. Whether wetlands are a net source or sink of atmospheric carbon under future climate change will depend on the response of the ecosystem to rising temperatures and elevated CO2. The largest uncertainty in future wetland budgets, and its climate forcing, is the stability of the large belowground carbon stocks, often in the form of peat, and the partitioning of CO2 and CH4released via ecosystem respiration. We have characterized the isotopic signatures (14,13C of CO2 and CH4, D-CH4) of the respired carbon used for the production of CO2 and CH4 from the DOE Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) site in the Marcell Experimental Forest, which contains replicated mesocosm manipulations including above/below ground warming and elevated CO2. Deep warming (1-2 m) was initiated in July of 2014 and above ground heating will be initiated in July 2015. Comparison of the respired CO2 and CH4with recently fixed photosynthate, below-ground peat (up to 11,000 years old), and dissolved organic carbon allow us to determine the primary substrates used by the microbial community. Control and pre-perturbed plots are characterized by the consumption and respiration of recently fixed photosynthate and recent (few years to 15 yr) carbon. Although CH4 fluxes have begun to respond to deep-heating, the source of carbon remains similar in the control and perturbed plots. Respired CO2 remains consistent with being sourced from carbon only a few years old. We will present additional data

  3. Autofluorescence of atmospheric bioaerosols - Biological standard particles and the influence of environmental conditions

    NASA Astrophysics Data System (ADS)

    Pöhlker, Christopher; Huffman, J. Alex; Förster, Jan-David; Pöschl, Ulrich

    2013-04-01

    standard bioparticles (pollen, fungal spores, and bacteria) as well as atmospherically relevant chemical substances. We addressed the sensitivity and selectivity of autofluorescence based online techniques. Moreover, we investigated the influence of environmental conditions, such as relative humidity and oxidizing agents in the atmosphere, on the autofluorescence signature of standard bioparticles. Our results will support the molecular understanding and quantitative interpretation of data obtained by real-time FBAP instrumentation [5,6]. [1] Elbert, W., Taylor, P. E., Andreae, M. O., & Pöschl, U. (2007). Atmos. Chem. Phys., 7, 4569-4588. [2] Huffman, J. A., Treutlein, B., & Pöschl, U. (2010). Atmos. Chem. Phys., 10, 3215-3233. [3] Pöschl, U., et al. (2010). Science, 329, 1513-1516. [4] Lakowicz, J., Principles of fluorescence spectroscopy, Plenum publishers, New York, 1999. [5] Pöhlker, C., Huffman, J. A., & Pöschl, U., (2012). Atmos. Meas. Tech., 5, 37-71. [6] Pöhlker, C., Huffman, J. A., Förster J.-D., & Pöschl, U., (2012) in preparation.

  4. Comparative analysis of electric field influence on the quantum wells with different boundary conditions.

    PubMed Central

    Olendski, Oleg

    2015-01-01

    Analytical solutions of the Schrödinger equation for the one-dimensional quantum well with all possible permutations of the Dirichlet and Neumann boundary conditions (BCs) in perpendicular to the interfaces uniform electric field are used for the comparative investigation of their interaction and its influence on the properties of the system. Limiting cases of the weak and strong voltages allow an easy mathematical treatment and its clear physical explanation; in particular, for the small , the perturbation theory derives for all geometries a linear dependence of the polarization on the field with the BC-dependent proportionality coefficient being positive (negative) for the ground (excited) states. Simple two-level approximation elementary explains the negative polarizations as a result of the field-induced destructive interference of the unperturbed modes and shows that in this case the admixture of only the neighboring states plays a dominant role. Different magnitudes of the polarization for different BCs in this regime are explained physically and confirmed numerically. Hellmann-Feynman theorem reveals a fundamental relation between the polarization and the speed of the energy change with the field. It is proved that zero-voltage position entropies are BC independent and for all states but the ground Neumann level (which has ) are equal to while the momentum entropies depend on the edge requirements and the level. Varying electric field changes position and momentum entropies in the opposite directions such that the entropic uncertainty relation is satisfied. Other physical quantities such as the BC-dependent zero-energy and zero-polarization fields are also studied both numerically and analytically. Applications to different branches of physics, such as ocean fluid dynamics and atmospheric and metallic waveguide electrodynamics, are discussed. PMID:25914413

  5. Watershed-Scale Land Use Activities Influence the Physiological Condition of Stream Fish.

    PubMed

    King, Gregory D; Chapman, Jacqueline M; Midwood, Jonathan D; Cooke, Steven J; Suski, Cory D

    2016-01-01

    Land use changes within watersheds can have large effects on stream ecosystems, but the mechanistic basis of those effects remains poorly understood. While changes to population size presumably reflect underlying variation in organismal health and condition, such individual-level metrics are rarely evaluated in the context of ecosystem disturbance. To ad