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Sample records for winter temperate zone

  1. Aerosol influenza transmission risk contours: A study of humid tropics versus winter temperate zone

    Directory of Open Access Journals (Sweden)

    Borup Birthe

    2010-05-01

    Full Text Available Abstract Background In recent years, much attention has been given to the spread of influenza around the world. With the continuing human outbreak of H5N1 beginning in 2003 and the H1N1 pandemic in 2009, focus on influenza and other respiratory viruses has been increased. It has been accepted for decades that international travel via jet aircraft is a major vector for global spread of influenza, and epidemiological differences between tropical and temperate regions observed. Thus we wanted to study how indoor environmental conditions (enclosed locations in the tropics and winter temperate zones contribute to the aerosol spread of influenza by travelers. To this end, a survey consisting of 632 readings of temperature (T versus relative humidity (RH in 389 different enclosed locations air travelers are likely to visit in 8 tropical nations were compared to 102 such readings in 2 Australian cities, including ground transport, hotels, shops, offices and other publicly accessible locations, along with 586 time course readings from aircraft. Results An influenza transmission risk contour map was developed for T versus RH. Empirical equations were created for estimating: 1. risk relative to temperature and RH, and 2. time parameterized influenza transmission risk. Using the transmission risk contours and equations, transmission risk for each country's locations was compared with influenza reports from the countries. Higher risk enclosed locations in the tropics included new automobile transport, luxury buses, luxury hotels, and bank branches. Most temperate locations were high risk. Conclusion Environmental control is recommended for public health mitigation focused on higher risk enclosed locations. Public health can make use of the methods developed to track potential vulnerability to aerosol influenza. The methods presented can also be used in influenza modeling. Accounting for differential aerosol transmission using T and RH can potentially explain

  2. Winter climate change: a critical factor for temperate vegetation performance.

    Science.gov (United States)

    Kreyling, Juergen

    2010-07-01

    Winter ecological processes are important drivers of vegetation and ecosystem functioning in temperate ecosystems. There, winter conditions are subject to rapid climate change. The potential loss of a longer-lasting snow cover with implications to other plant-related climate parameters and overwintering strategies make the temperate zone particularly vulnerable to winter climate change. A formalized literature search in the ISI Web of Science shows that plant related research on the effects of winter climate change is generally underrepresented. Temperate regions in particular are rarely studied in this respect, although the few existing studies imply strong effects of winter climate change on species ranges, species compositions, phenology, or frost injury. The generally positive effect of warming on plant survival and production may be counteracted by effects such as an increased frost injury of roots and shoots, an increased insect pest risk, or a disrupted synchrony between plants and pollinators. Based on the literature study, gaps in current knowledge are discussed. Understanding the relative effects of interacting climate parameters, as well as a stronger consideration of shortterm events and variability of climatic conditions is urgent. With respect to plant response, it would be particularly worthwhile to account for hidden players such as pathogens, pollinators, herbivores, or fungal partners in mycorrhization.

  3. Winter Storm Zones on Mars

    Science.gov (United States)

    Hollingsworth, J. L.; Haberle, R. M.; Barnes, J. R.; Bridger, A. F. C.; Cuzzi, Jeffrey N. (Technical Monitor)

    1995-01-01

    Preferred regions of weather activity in Mars' winter middle latitudes-so called 'storm zones' are found in a general circulation model of Mars' atmospheric circulation. During northern winter, these storm zones occur in middle latitudes in the major planitia (low-relief regions) of the western and eastern hemisphere. In contrast, the highlands of the eastern hemisphere are mostly quiescent. Compared to Earth's storm zones where diabatic heating associated with land-sea thermal contrasts is crucial, orography on Mars is fundamental to the regionalization of weather activity. Future spacecraft missions aimed at assessing Mars' climate and its variability need to include such regions in observation strategies.

  4. Ice duration drives winter nitrate accumulation in north temperate lakes

    Science.gov (United States)

    Powers, Steven M; Labou, Stephanie G.; Baulch, Helen M.; Hunt, Randall J.; Lottig, Noah R.; Hampton, Stephanie E.; Stanley, Emily H.

    2017-01-01

    The duration of winter ice cover on lakes varies substantially with climate variability, and has decreased over the last several decades in many temperate lakes. However, little is known of how changes in seasonal ice cover may affect biogeochemical processes under ice. We examined winter nitrogen (N) dynamics under ice using a 30+ yr dataset from five oligotrophic/mesotrophic north temperate lakes to determine how changes in inorganic N species varied with ice duration. Nitrate accumulated during winter and was strongly related to the number of days since ice-on. Exogenous inputs accounted for less than 3% of nitrate accumulation in four of the five lakes, suggesting a paramount role of nitrification in regulating N transformation and the timing of chemical conditions under ice. Winter nitrate accumulation rates ranged from 0.15 μg N L−1 d−1 to 2.7 μg N L−1 d−1 (0.011–0.19 μM d−1), and the mean for intermediate depths was 0.94 μg N L−1 d−1(0.067 μM d−1). Given that winters with shorter ice duration (< 120 d) have become more frequent in these lakes since the late 1990s, peak winter nitrate concentrations and cumulative nitrate production under ice may be declining. As ice extent and duration change, the physical and chemical conditions supporting life will shift. This research suggests we may expect changes in the form and amount of inorganic N, and altered dissolved nitrogen : phosphorus ratios, in lakes during winters with shorter ice duration.

  5. Winter habitat occurrence patterns of temperate migrant birds in Belize

    Science.gov (United States)

    Dawson, D.K.; Robbins, C.S.; Sauer, J.R.

    1992-01-01

    We used mist nets and point counts to sample bird populations in 61 sites in Belize during January-March of 1987-1991. Sites were classified as forest, second growth, woody agricultural crops (citrus, mango, cacao, and cashew), or non-woody agricultural crops (rice and sugar cane). We evaluated patterns of occurence of wintering temperate migrant bird species in these habitats. Mist net captures of 22 of 31 migrant species differed significantly among habitats. Of these, 13 species were captured more frequently in the agricultural habitats. American Redstart (Setophaga ruticilla), Black-and-white Warbler (Mniotilta varia), and Magnolia Warbler (Dendroica magnolia) were among the species captured most frequently in woody agricultural habitats; captures of Common Yellowthroat (Geothlypis trichas), Indigo Bunting (Passerina cyanea), and Northern (lcterus galbula) and Orchard orioles (I. spur/anus) were highest in the non-woody agricultural sites. We relate these occurrence patterns to trends in breeding populations in North America. While count data provide a wide picture of winter habitat distribution of migrants, more intensive work is necessary to assess temporal and geographic variation of migrant bird use of agricultural habitats.

  6. Does Zoning Winter Recreationists Reduce Recreation Conflict?

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    Miller, Aubrey D.; Vaske, Jerry J.; Squires, John R.; Olson, Lucretia E.; Roberts, Elizabeth K.

    2017-01-01

    Parks and protected area managers use zoning to decrease interpersonal conflict between recreationists. Zoning, or segregation, of recreation—often by non-motorized and motorized activity—is designed to limit physical interaction while providing recreation opportunities to both groups. This article investigated the effectiveness of zoning to reduce recreation conflict in the Vail Pass Winter Recreation Area in Colorado, USA. Despite a zoning management system, established groomed travel routes were used by both non-motorized recreationists (backcountry skiers, snowboarders, snowshoers) and motorized recreationists (snowmobilers). We hypothesized that persistent recreation conflict reported by non-motorized recreationists was the result of recreation occurring in areas of mixed non-motorized and motorized use, mostly along groomed routes. We performed a geospatial analysis of recreation [from Global Positioning System (GPS) points, n = 1,233,449] in the Vail Pass Winter Recreation Area to identify areas of mixed non-motorized and motorized use. We then surveyed non-motorized recreationists ( n = 199) to test whether reported conflict is higher for respondents who traveled in areas of mixed-use, compared with respondents traveling outside areas of mixed-use. Results from the geospatial analysis showed that only 0.7 % of the Vail Pass Winter Recreation Area contained recreation from both groups, however that area contained 14.8 % of all non-motorized recreation and 49.1 % of all motorized recreation. Survey analysis results showed higher interpersonal conflict for all five standard conflict variables among non-motorized respondents who traveled in areas of mixed-use, compared with those traveling outside mixed-use areas. Management implications and recommendations for increasing the effectiveness of zoning are provided.

  7. Does Zoning Winter Recreationists Reduce Recreation Conflict?

    Science.gov (United States)

    Miller, Aubrey D; Vaske, Jerry J; Squires, John R; Olson, Lucretia E; Roberts, Elizabeth K

    2017-01-01

    Parks and protected area managers use zoning to decrease interpersonal conflict between recreationists. Zoning, or segregation, of recreation-often by non-motorized and motorized activity-is designed to limit physical interaction while providing recreation opportunities to both groups. This article investigated the effectiveness of zoning to reduce recreation conflict in the Vail Pass Winter Recreation Area in Colorado, USA. Despite a zoning management system, established groomed travel routes were used by both non-motorized recreationists (backcountry skiers, snowboarders, snowshoers) and motorized recreationists (snowmobilers). We hypothesized that persistent recreation conflict reported by non-motorized recreationists was the result of recreation occurring in areas of mixed non-motorized and motorized use, mostly along groomed routes. We performed a geospatial analysis of recreation [from Global Positioning System (GPS) points, n = 1,233,449] in the Vail Pass Winter Recreation Area to identify areas of mixed non-motorized and motorized use. We then surveyed non-motorized recreationists (n = 199) to test whether reported conflict is higher for respondents who traveled in areas of mixed-use, compared with respondents traveling outside areas of mixed-use. Results from the geospatial analysis showed that only 0.7 % of the Vail Pass Winter Recreation Area contained recreation from both groups, however that area contained 14.8 % of all non-motorized recreation and 49.1 % of all motorized recreation. Survey analysis results showed higher interpersonal conflict for all five standard conflict variables among non-motorized respondents who traveled in areas of mixed-use, compared with those traveling outside mixed-use areas. Management implications and recommendations for increasing the effectiveness of zoning are provided.

  8. Hardy exotics species in temperate zone: can "warm water" crayfish invaders establish regardless of low temperatures?

    Science.gov (United States)

    Veselý, Lukáš; Buřič, Miloš; Kouba, Antonín

    2015-11-17

    The spreading of new crayfish species poses a serious risk for freshwater ecosystems; because they are omnivores they influence more than one level in the trophic chain and they represent a significant part of the benthic biomass. Both the environmental change through global warming and the expansion of the pet trade increase the possibilities of their spreading. We investigated the potential of four "warm water" highly invasive crayfish species to overwinter in the temperate zone, so as to predict whether these species pose a risk for European freshwaters. We used 15 specimens of each of the following species: the red swamp crayfish (Procambarus clarkii), the marbled crayfish (Procambarus fallax f. virginalis), the yabby (Cherax destructor), and the redclaw (Cherax quadricarinatus). Specimens were acclimatized and kept for 6.5 months at temperatures simulating the winter temperature regime of European temperate zone lentic ecosystems. We conclude that the red swamp crayfish, marbled crayfish and yabby have the ability to withstand low winter temperatures relevant for lentic habitats in the European temperate zone, making them a serious invasive threat to freshwater ecosystems.

  9. Climate Change Affects Winter Chill for Temperate Fruit and Nut Trees

    OpenAIRE

    Eike Luedeling; Girvetz, Evan H.; Semenov, Mikhail A.; Brown, Patrick H.

    2011-01-01

    BACKGROUND: Temperate fruit and nut trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. METHODOLOGY/PRINCIPAL FINDINGS: We estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Win...

  10. Plasmodium vivax malaria: a re-emerging threat for temperate climate zones?

    Science.gov (United States)

    Petersen, Eskild; Severini, Carlo; Picot, Stephane

    2013-01-01

    Plasmodium vivax was endemic in temperate areas in historic times up to the middle of last century. Temperate climate P. vivax has a long incubation time of up to 8-10 months, which partly explain how it can be endemic in temperate areas with a could winter. P. vivax disappeared from Europe within the last 40-60 years, and this change was not related to climatic changes. The surge of P. vivax in Northern Europe after the second world war was related to displacement of refugees and large movement of military personnel exposed to malaria. Lately P. vivax has been seen along the demilitarized zone in South Korea replication a high endemicity in North Korea. The potential of transmission of P. vivax still exist in temperate zones, but reintroduction in a larger scale of P. vivax to areas without present transmission require large population movements of P. vivax infected people. The highest threat at present is refugees from P. vivax endemic North Korea entering China and South Korea in large numbers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Responses of Winter Wheat Yields to Warming-Mediated Vernalization Variations Across Temperate Europe

    Directory of Open Access Journals (Sweden)

    Xiuchen Wu

    2017-10-01

    Full Text Available Rapid climate warming, with much higher warming rates in winter and spring, could affect the vernalization fulfillment, a critical process for induction of crop reproductive growth and consequent grain filling in temperate winter crops. However, regional observational evidence of the effects of historical warming-mediated vernalization variations on temperate winter crop yields is lacking. Here, we statistically quantified the interannual sensitivity of winter wheat yields to vernalization degree days (VDD during 1975–2009 and its spatial relationship with multi-year mean VDD over temperate Europe (TE, using EUROSTAT crop yield statistics, observed and simulated crop phenology data and gridded daily climate data. Our results revealed a pervasively positive interannual sensitivity of winter wheat yields to variations in VDD (γVDD over TE, with a mean γVDD of 2.8 ± 1.5 kg ha−1 VDD−1. We revealed a significant (p < 0.05 negative exponential relationship between γVDD and multi-year mean VDD for winter wheat across TE, with higher γVDD in winter wheat planting areas with lower multi-year mean VDD. Our findings shed light on potential vulnerability of winter wheat yields to warming-mediated vernalization variations over TE, particularly considering a likely future warmer climate.

  12. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    NARCIS (Netherlands)

    Ciais, P.; Wang, T.; Piao, S.L.; Ottlé, C.; Brender, P.; Moors, E.J.

    2011-01-01

    Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the

  13. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    Science.gov (United States)

    T. Wang; P. Ciais; S.L. Piao; C. Ottle; P. Brender; F. Maignan; A. Arain; A. Cescatti; D. Gianelle; C. Gough; L Gu; P. Lafleur; T. Laurila; B. Marcolla; H. Margolis; L. Montagnani; E. Moors; N. Saigusa; T. Vesala; G. Wohlfahrt; C. Koven; A. Black; E. Dellwik; A. Don; D. Hollinger; A. Knohl; R. Monson; J. Munger; A. Suyker; A. Varlagin; S. Verma

    2011-01-01

    Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal...

  14. Winter chilling speeds spring development of temperate butterflies.

    Science.gov (United States)

    Stålhandske, Sandra; Gotthard, Karl; Leimar, Olof

    2017-07-01

    Understanding and predicting phenology has become more important with ongoing climate change and has brought about great research efforts in the recent decades. The majority of studies examining spring phenology of insects have focussed on the effects of spring temperatures alone. Here we use citizen-collected observation data to show that winter cold duration, in addition to spring temperature, can affect the spring emergence of butterflies. Using spatial mixed models, we disentangle the effects of climate variables and reveal impacts of both spring and winter conditions for five butterfly species that overwinter as pupae across the UK, with data from 1976 to 2013 and one butterfly species in Sweden, with data from 2001 to 2013. Warmer springs lead to earlier emergence in all species and milder winters lead to statistically significant delays in three of the five investigated species. We also find that the delaying effect of winter warmth has become more pronounced in the last decade, during which time winter durations have become shorter. For one of the studied species, Anthocharis cardamines (orange tip butterfly), we also make use of parameters determined from previous experiments on pupal development to model the spring phenology. Using daily temperatures in the UK and Sweden, we show that recent variation in spring temperature corresponds to 10-15 day changes in emergence time over UK and Sweden, whereas variation in winter duration corresponds to 20 days variation in the south of the UK versus only 3 days in the south of Sweden. In summary, we show that short winters delay phenology. The effect is most prominent in areas with particularly mild winters, emphasising the importance of winter for the response of ectothermic animals to climate change. With climate change, these effects may become even stronger and apply also at higher latitudes. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  15. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    Directory of Open Access Journals (Sweden)

    T. Wang

    2011-07-01

    Full Text Available Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal patterns of winter ecosystem respiration (Reco of northern ecosystems are poorly understood. For this reason, we analyzed eddy covariance flux data from 57 ecosystem sites ranging from ~35° N to ~70° N. Deciduous forests were characterized by the highest winter Reco rates (0.90 ± 0.39 g C m−2 d−1, when winter is defined as the period during which daily air temperature remains below 0 °C. By contrast, arctic wetlands had the lowest winter Reco rates (0.02 ± 0.02 g C m−2 d−1. Mixed forests, evergreen needle-leaved forests, grasslands, croplands and boreal wetlands were characterized by intermediate winter Reco rates (g C m−2 d−1 of 0.70(±0.33, 0.60(±0.38, 0.62(±0.43, 0.49(±0.22 and 0.27(±0.08, respectively. Our cross site analysis showed that winter air (Tair and soil (Tsoil temperature played a dominating role in determining the spatial patterns of winter Reco in both forest and managed ecosystems (grasslands and croplands. Besides temperature, the seasonal amplitude of the leaf area index (LAI, inferred from satellite observation, or growing season gross primary productivity, which we use here as a proxy for the amount of recent carbon available for Reco in the subsequent winter, played a marginal role in winter CO2 emissions from forest ecosystems. We found that winter Reco sensitivity to temperature variation across space (

  16. Winter soil respiration in a humid temperate forest: The roles of moisture, temperature, and snowpack

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    Contosta, Alexandra R.; Burakowski, Elizabeth A.; Varner, Ruth K.; Frey, Serita D.

    2016-12-01

    Winter soil respiration at midlatitudes can comprise a substantial portion of annual ecosystem carbon loss. However, winter soil carbon dynamics in these areas, which are often characterized by shallow snow cover, are poorly understood due to infrequent sampling at the soil surface. Our objectives were to continuously measure winter CO2 flux from soils and the overlying snowpack while also monitoring drivers of winter soil respiration in a humid temperate forest. We show that the relative roles of soil temperature and moisture in driving winter CO2 flux differed within a single soil-to-snow profile. Surface soil temperatures had a strong, positive influence on CO2 flux from the snowpack, while soil moisture exerted a negative control on soil CO2 flux within the soil profile. Rapid fluctuations in snow depth throughout the winter likely created the dynamic soil temperature and moisture conditions that drove divergent patterns in soil respiration at different depths. Such dynamic conditions differ from many previous studies of winter soil microclimate and respiration, where soil temperature and moisture are relatively stable until snowmelt. The differential response of soil respiration to temperature and moisture across depths was also a unique finding as previous work has not simultaneously quantified CO2 flux from soils and the snowpack. The complex interplay we observed among snow depth, soil temperature, soil moisture, and CO2 flux suggests that winter soil respiration in areas with shallow seasonal snow cover is more variable than previously understood and may fluctuate considerably in the future given winter climate change.

  17. Does zoning winter recreationists reduce recreation conflict?

    Science.gov (United States)

    Aubrey D. Miller; Jerry J. Vaske; John R. Squires; Lucretia E. Olson; Elizabeth K. Roberts

    2017-01-01

    Parks and protected area managers use zoning to decrease interpersonal conflict between recreationists. Zoning, or segregation, of recreation - often by nonmotorized and motorized activity - is designed to limit physical interaction while providing recreation opportunities to both groups. This article investigated the effectiveness of zoning to reduce recreation...

  18. Climate change affects winter chill for temperate fruit and nut trees.

    Directory of Open Access Journals (Sweden)

    Eike Luedeling

    Full Text Available BACKGROUND: Temperate fruit and nut trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. METHODOLOGY/PRINCIPAL FINDINGS: We estimated winter chill for two past (1975 and 2000 and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios. For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC, the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the "Dynamic Model" and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG. CONCLUSIONS/SIGNIFICANCE: The extent of projected changes in winter chill in many major growing regions of fruits and nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops.

  19. Climate change affects winter chill for temperate fruit and nut trees.

    Science.gov (United States)

    Luedeling, Eike; Girvetz, Evan H; Semenov, Mikhail A; Brown, Patrick H

    2011-01-01

    Temperate fruit and nut trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. We estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC), the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the "Dynamic Model" and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP) for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG. The extent of projected changes in winter chill in many major growing regions of fruits and nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops.

  20. Hardy exotics species in temperate zone: can “warm water” crayfish invaders establish regardless of low temperatures?

    Science.gov (United States)

    Veselý, Lukáš; Buřič, Miloš; Kouba, Antonín

    2015-01-01

    The spreading of new crayfish species poses a serious risk for freshwater ecosystems; because they are omnivores they influence more than one level in the trophic chain and they represent a significant part of the benthic biomass. Both the environmental change through global warming and the expansion of the pet trade increase the possibilities of their spreading. We investigated the potential of four “warm water” highly invasive crayfish species to overwinter in the temperate zone, so as to predict whether these species pose a risk for European freshwaters. We used 15 specimens of each of the following species: the red swamp crayfish (Procambarus clarkii), the marbled crayfish (Procambarus fallax f. virginalis), the yabby (Cherax destructor), and the redclaw (Cherax quadricarinatus). Specimens were acclimatized and kept for 6.5 months at temperatures simulating the winter temperature regime of European temperate zone lentic ecosystems. We conclude that the red swamp crayfish, marbled crayfish and yabby have the ability to withstand low winter temperatures relevant for lentic habitats in the European temperate zone, making them a serious invasive threat to freshwater ecosystems. PMID:26572317

  1. Does winter warming enhance cold CO2 emission from temperate continental soils?

    Science.gov (United States)

    Kurganova, Irina; Lopes de Gerenyu, Valentin; Khoroshaev, Dmitry

    2016-04-01

    In subboreal and temperate regions, the cold season generally lasts more than 3 months of the year, influencing the carbon cycle in terrestrial ecosystems. The permanent snow pack plays an important role in the functioning of the ecosystem, especially in temperate continental regions, preventing frost penetration into the soil. The extent and duration of the permanent snow pack are predicted to decrease markedly in transitional seasons for many boreal and subboreal regions during the next 50 years. This study focused on: (i) assessment of current winter climate trends in the Moscow region pertaining to the continental temperate region, (ii) comparison of soil temperature regimes at different snow pack depths, (iii) estimation of cold CO2 fluxes from soils under various frozen regime and vegetation cover, and (iv) the contribution of freezing-thawing events to the total cold CO2 emission from soils in the temperate continental region. An experiment with regulated snow cover was established on grassland and bare soil (Luvisols Haplic, Moscow region, 54o50'N, 37o36'E; continental temperate climate). The following winter scenarios were foreseen: (1) reference plot, designated "Ref", with natural depth of snow cover, (2) no-frost, "NoFr" (simulation of deep snow cover using artificial heat insulation material), and (3) no-snow, "NoSn" (without snow cover). We observed inverse trends as the air temperature increased and precipitation decreased, which resulted in a 1-month prolongation of the snow-free period and a decrease in the snow pack over the last 20 years. Soil freezing significantly reduced the cold CO2 fluxes from soils: by 10-70% in the bare areas and by up to double that amount in the grass plots. There were six freezing-thawing cycles (FTC; 1-7 weeks' duration) from October 2014 to early April 2015, which induced CO2 emission pulses of varying intensity. The highest peaks of CO2 emission rate (3-30-fold increase compared to the pre-thawing period) were

  2. Silicon pools in human impacted soils of temperate zones

    Science.gov (United States)

    Vandevenne, F. I.; Barão, L.; Ronchi, B.; Govers, G.; Meire, P.; Kelly, E. F.; Struyf, E.

    2015-09-01

    Besides well-known effects of climate and parent material on silicate weathering the role of land use change as a driver in the global silicon cycle is not well known. Changes in vegetation cover have altered reservoirs of silicon and carbon in plants and soils. This has potential consequences for plant-Si availability, agricultural yields, and coastal eutrophication, as Si is a beneficial element for many crop plants and an essential nutrient for diatom growth. We here examined the role of sustained and intensive land use and human disturbance on silicon (Si) pool distribution in soils with similar climatological and bulk mineralogical characteristics. We show that land use impacts both biogenic and nonbiogenic Si pools. While biogenic Si strongly decreases along the land use change gradient (from forest to croplands), pedogenic silica fractions (e.g. pedogenic clays) increase in topsoils with a long duration of cultivation and soil disturbance. Our results suggest that nonbiogenic Si pools might compensate for the loss of reactive biogenic silicon in temperate zones.

  3. Changes in winter conditions impact forest management in north temperate forests.

    Science.gov (United States)

    Rittenhouse, Chadwick D; Rissman, Adena R

    2015-02-01

    Climate change may impact forest management activities with important implications for forest ecosystems. However, most climate change research on forests has focused on climate-driven shifts in species ranges, forest carbon, and hydrology. To examine how climate change may alter timber harvesting and forest operations in north temperate forests, we asked: 1) How have winter conditions changed over the past 60 years? 2) Have changes in winter weather altered timber harvest patterns on public forestlands? 3) What are the implications of changes in winter weather conditions for timber harvest operations in the context of the economic, ecological, and social goals of forest management? Using meteorological information from Climate Data Online and Autoregressive Integrated Moving Average (ARIMA) models we document substantial changes in winter conditions in Wisconsin, including a two- to three-week shortening of frozen ground conditions from 1948 to 2012. Increases in minimum and mean soil temperatures were spatially heterogeneous. Analysis of timber harvest records identified a shift toward greater harvest of jack pine and red pine and less harvest of aspen, black spruce, hemlock, red maple, and white spruce in years with less frozen ground or snow duration. Interviews suggested that frozen ground is a mediating condition that enables low-impact timber harvesting. Climate change may alter frozen ground conditions with complex implications for forest management. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. How predictable is the winter extremely cold days over temperate East Asia?

    Science.gov (United States)

    Luo, Xiao; Wang, Bin

    2017-04-01

    Skillful seasonal prediction of the number of extremely cold day (NECD) has considerable benefits for climate risk management and economic planning. Yet, predictability of NECD associated with East Asia winter monsoon remains largely unexplored. The present work estimates the NECD predictability in temperate East Asia (TEA, 30°-50°N, 110°-140°E) where the current dynamical models exhibit limited prediction skill. We show that about 50 % of the total variance of the NECD in TEA region is likely predictable, which is estimated by using a physics-based empirical (P-E) model with three consequential autumn predictors, i.e., developing El Niño/La Niña, Eurasian Arctic Ocean temperature anomalies, and geopotential height anomalies over northern and eastern Asia. We find that the barotropic geopotential height anomaly over Asia can persist from autumn to winter, thereby serving as a predictor for winter NECD. Further analysis reveals that the sources of the NECD predictability and the physical basis for prediction of NECD are essentially the same as those for prediction of winter mean temperature over the same region. This finding implies that forecasting seasonal mean temperature can provide useful information for prediction of extreme cold events. Interpretation of the lead-lag linkages between the three predictors and the predictand is provided for stimulating further studies.

  5. Influence of tropical easterlies in southern Africa's winter rainfall zone during the Holocene

    Science.gov (United States)

    Chase, Brian M.; Lim, Sophak; Chevalier, Manuel; Boom, Arnoud; Carr, Andrew S.; Meadows, Michael E.; Reimer, Paula J.

    2015-01-01

    South Africa's southwestern Cape occupies a critical transition zone between Southern Hemisphere temperate (winter) and tropical (summer) moisture-bearing systems. In the recent geological past, it has been proposed that the relative influence of these systems may have changed substantially, but little reliable evidence regarding regional hydroclimates and rainfall seasonality exists to refine or substantiate the understanding of long-term dynamics. In this paper we present a mid-to late Holocene multi-proxy record of environmental change from a rock hyrax midden from Katbakkies Pass, located along the modern boundary between the winter and summer rainfall zones. Derived from stable carbon and nitrogen isotopes, fossil pollen and microcharcoal, these data provide a high resolution record of changes in humidity, and insight into changes in rainfall seasonality. Whereas previous work concluded that the site had generally experienced only subtle environmental change during the Holocene, our records indicate that significant, abrupt changes have occurred in the region over the last 7000 years. Contrary to expectations based on the site's location, these data indicate that the primary determinant of changes in humidity is summer rather than winter rainfall variability, and its influence on drought season intensity and/or length. These findings are consistent with independent records of upwelling along the southern and western coasts, which indicate that periods of increased humidity are related to increased tropical easterly flow. This substantially refines our understanding of the nature of temperate and tropical circulation system dynamics in SW Africa, and how changes in their relative dominance have impacted regional environments during the Holocene.

  6. Warmer winters increase the rhizosphere carbon flow to mycorrhizal fungi more than to other microorganisms in a temperate grassland.

    Science.gov (United States)

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

    2017-12-01

    A decisive set of steps in the terrestrial carbon (C) cycle is the fixation of atmospheric C by plants and the subsequent C-transfer to rhizosphere microorganisms. With climate change winters are expected to become milder in temperate ecosystems. Although the rate and pathways of rhizosphere C input to soil could be impacted by milder winters, the responses remain unknown. To address this knowledge-gap, a winter-warming experiment was established in a seminatural temperate grassland to follow the C flow from atmosphere, via the plants, to different groups of soil microorganisms. In situ 13 CO2 pulse labelling was used to track C into signature fatty acids of microorganisms. The winter warming did not result in any changes in biomass of any of the groups of microorganisms. However, the C flow from plants to arbuscular mycorrhizal (AM) fungi, increased substantially by winter warming. Saprotrophic fungi also received large amounts of plant-derived C-indicating a higher importance for the turnover of rhizosphere C than biomass estimates would suggest-still, this C flow was unaffected by winter warming. AM fungi was the only microbial group positively affected by winter warming-the group with the closest connection to plants. Winter warming resulted in higher plant productivity earlier in the season, and this aboveground change likely induced plant nutrient limitation in warmed plots, thus stimulating the plant dependence on, and C allocation to, belowground nutrient acquisition. The preferential C allocation to AM fungi was at the expense of C flow to other microbial groups, which were unaffected by warming. Our findings imply that warmer winters may shift rhizosphere C-fluxes to become more AM fungal-dominated. Surprisingly, the stimulated rhizosphere C flow was matched by increased microbial turnover, leading to no accumulation of soil microbial biomass. © 2017 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

  7. Responses of the photosynthetic apparatus to winter conditions in broadleaved evergreen trees growing in warm temperate regions of Japan.

    Science.gov (United States)

    Tanaka, Chizuru; Nakano, Takashi; Yamazaki, Jun-Ya; Maruta, Emiko

    2015-01-01

    Photosynthetic characteristics of two broadleaved evergreen trees, Quercus myrsinaefolia and Machilus thunbergii, were compared in autumn and winter. The irradiance was similar in both seasons, but the air temperature was lower in winter. Under the winter conditions, net photosynthesis under natural sunlight (Anet) in both species dropped to 4 μmol CO2 m(-2) s(-1), and the quantum yield of photosystem II (PSII) photochemistry in dark-adapted leaves (Fv/Fm) also dropped to 0.60. In both species the maximum carboxylation rates of Rubisco (V(cmax)) decreased, and the amount of Rubisco increased in winter. A decline in chlorophyll (Chl) concentration and an increase in the Chl a/b ratio in winter resulted in a reduction in the size of the light-harvesting antennae. From measurements of Chl a fluorescence parameters, both the relative fraction and the energy flux rates of thermal dissipation through other non-photochemical processes were markedly elevated in winter. The results indicate that the photosynthetic apparatus in broadleaved evergreen species in warm temperate regions responds to winter through regulatory mechanisms involving the downregulation of light-harvesting and photosynthesis coupled with increased photoprotective thermal energy dissipation to minimize photodamage in winter. These mechanisms aid a quick restart of photosynthesis without the development of new leaves in the following spring. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  8. Variations of Soil Microbial Community Structures Beneath Broadleaved Forest Trees in Temperate and Subtropical Climate Zones.

    Science.gov (United States)

    Yang, Sihang; Zhang, Yuguang; Cong, Jing; Wang, Mengmeng; Zhao, Mengxin; Lu, Hui; Xie, Changyi; Yang, Caiyun; Yuan, Tong; Li, Diqiang; Zhou, Jizhong; Gu, Baohua; Yang, Yunfeng

    2017-01-01

    Global warming has shifted climate zones poleward or upward. However, understanding the responses and mechanism of microbial community structure and functions relevant to natural climate zone succession is challenged by the high complexity of microbial communities. Here, we examined soil microbial community in three broadleaved forests located in the Wulu Mountain (WLM, temperate climate), Funiu Mountain (FNM, at the border of temperate and subtropical climate zones), or Shennongjia Mountain (SNJ, subtropical climate). Although plant species richness decreased with latitudes, the microbial taxonomic α-diversity increased with latitudes, concomitant with increases in soil total and available nitrogen and phosphorus contents. Phylogenetic NRI (Net Relatedness Index) values increased from -0.718 in temperate zone (WLM) to 1.042 in subtropical zone (SNJ), showing a shift from over dispersion to clustering likely caused by environmental filtering such as low pH and nutrients. Similarly, taxonomy-based association networks of subtropical forest samples were larger and tighter, suggesting clustering. In contrast, functional α-diversity was similar among three forests, but functional gene networks of the FNM forest significantly (P climate zones. Using a strategy of space-for-time substitution, we predict that poleward climate range shift will lead to decreased microbial taxonomic α-diversities in broadleaved forest.

  9. Pulsed resources at tundra breeding sites affect winter irruptions at temperate latitudes of a top predator, the snowy owl.

    Science.gov (United States)

    Robillard, A; Therrien, J F; Gauthier, G; Clark, K M; Bêty, J

    2016-06-01

    Irruptive migration is mostly observed in species specialized on pulsed resources and is thought to be a response to unpredictable changes in food supply. We assessed two alternative hypotheses to explain the periodic winter irruptions of snowy owls Bubo scandiacus every 3-5 years in temperate North America: (a) the lack-of-food hypothesis, which states that a crash in small mammal abundance on the Arctic breeding grounds forces owls to move out of the tundra massively to search for food in winter; (b) the breeding-success hypothesis, which states that high abundance of tundra small mammals during the summer allows for high production of young, thus increasing the pool of migrants moving south the following winter. We modeled winter irruptions of snowy owls in relation to summer food resources and geographic location. Winter abundance of owls was obtained from citizen-based surveys from 1994 to 2011 and summer abundance of small mammals was collected in summer at two distant sites in Canada: Bylot Island, NU (eastern High Arctic) and Daring Lake, NWT (central Low Arctic). Winter owl abundance was positively related to prey abundance during the previous summer at both sites and tended to decrease from western to eastern temperate North America. Irruptive migration of snowy owls was therefore best explained by the breeding success hypothesis and was apparently caused by large-scale summer variations in food. Our results, combined with previous findings, suggest that the main determinants of irruptive migration may be species specific even in a guild of apparently similar species.

  10. Role of temperate zone forests in the world carbon cycle: problem definition and research needs

    Energy Technology Data Exchange (ETDEWEB)

    Armentano, T.V.; Hett, J. (eds.)

    1979-01-01

    The proceedings of a workshop on carbon uptake and losses from temperate zone forests are presented. The goals of the workshop were to analyze existing data on growth and utilization of the temperate zone forest carbon pool and to identify further research needs in relation to the role of temperate forests in the global carbon cycle. Total standing stock and growth recovery transients were examined for most of the temperate region over a period from pre-settlement times to the present, with emphasis on the last three decades. Because of data availability, certain regions and topics were covered more in detail than others. Forest inventory data from most of the commercial timberlands of the north temperate zone suggest these forests have functioned over the past several decades as an annual sink for about 10/sup 9/ metric tons of carbon. Thus, net growth of these forests has withdrawn carbon from the atmosphere at a rate equivalent, approximately, to 50% of the annual rise in atmospheric carbon. Various data inadequacies make this estimate probably no more precise than plus or minus half of the value. Analysis of growth and vegetation changes in New England and the southeastern United States shows that forest biomass has partly recovered since extensive clearing took place in the 18th and 19th centuries. This regrowth represents a net withdrawal of carbon (carbon sink) from the atmosphere in recent decades, although the difference in pool size between present and original forests means that, in the longer term, the two regions have functioned as carbon sources.

  11. Possibilities and limitations of weed management in fruit crops of the temperate climate zone

    OpenAIRE

    Lisek Jerzy

    2014-01-01

    This manuscript contains information on the species composition of weed communities in orchards in Poland and other countries of the temperate climate zone. The manuscript deals with the influence of weeds on crops and the interaction between the weeds and other living organisms. The main methods of weed regulation are described. Characteristics of the particular crops – fruit trees and small fruits – and solutions that are either objects of study or have already been introduced into...

  12. Economic analysis of stockless, horticultural crop rotations on a model farm in temperate zone organic systems

    OpenAIRE

    SCHMUTZ Ulrich; Firth, Chris; Rayns, Francis

    2005-01-01

    Research draws on an organic research farm site in central England with a temperate zone climate - fairly common for the northern lowlands of Europe. The soil type is a sandy loam with 591 mm rainfall. Detailed economic and agronomic data have been collected since conversion began in 1995. The economic analysis discusses rotational gross and net margins of more than 30 different rotations with different fertility building and vegetable crops (potatoes, cabbages, onions, carrots, leeks and par...

  13. Use of the Dynamic Model for the Assessment of Winter Chilling in a Temperate and a Subtropical Climatic Zone of Chile Utilización del Modelo Dinámico para Evaluar el Frío Invernal en una Localidad de Clima Templado y otra Subtropical de Chile

    Directory of Open Access Journals (Sweden)

    Francisco J Pérez

    2008-06-01

    Full Text Available Accumulated chilling was estimated by applying three different models to the hourly autumn-winter temperature records from Santiago (33°34 S lat; 625 m.a.s.l. and Vicuña (30°02´ S lat; 643 m.a.s.l. for the years 2005 and 2006. The model of chilling hours, currently used in Chile as an agroclimatic indicator, was of limited use for effectively contrasting a subtropical condition (Vicuña with a temperate area such as Santiago. The application of the Utah model gave negative values from March to May, and even up to June in Vicuña, since in this model the chilling effect is “negated” by warmer temperatures. However, a modified version of the Utah model named Positive Chilling Units (PCU, in which negative values are omitted, showed differences in the accumulated chilling between both regions, although these differences were of small magnitude and were noted only from July onwards. The Dynamic Model, which considers that chilling is irreversibly accumulated as quantum or Chill Portions (CP, showed that chilling in Santiago doubled that of Vicuña, and that these differences in location were already expressed at the beginning of autumn, confirming, thus, the suitability of the model for subtropical conditions. In this work the advantages of the dynamic model over other models are discussed.Se evaluó el frío invernal acumulado en Santiago (33°34´ lat. Sur; 625 m.s.n.m.; Región Metropolitana y Vicuña (30°02´ lat. Sur; 643 m.s.n.m.; Región de Coquimbo durante las temporadas 2005 y 2006 aplicando tres diferentes modelos. El modelo de horas-frío (CH, actualmente empleado como indicador agroclimático en Chile, resultó de poca utilidad para contrastar efectivamente la condición subtropical de Vicuña con la condición templada de Santiago. Al utilizar el modelo de Utah se obtuvieron valores negativos de marzo a mayo e incluso hasta el mes de junio en Vicuña, ya que, precisamente, con este modelo el efecto del frío es anulado por las

  14. Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies

    Directory of Open Access Journals (Sweden)

    J. C. Stager

    2012-05-01

    Full Text Available The austral westerlies strongly influence precipitation and ocean circulation in the southern temperate zone, with important consequences for cultures and ecosystems. Global climate models anticipate poleward retreat of the austral westerlies with future warming, but the available paleoclimate records that might test these models have been limited to South America and New Zealand, are not fully consistent with each other and may be complicated by influences from other climatic factors. Here we present the first high-resolution diatom and sedimentological records from the winter rainfall region of South Africa, representing precipitation in the equatorward margin of the westerly wind belt during the last 1400 yr. Inferred rainfall was relatively high ∼1400–1200 cal yr BP, decreased until ∼950 cal yr BP, and rose notably through the Little Ice Age with pulses centred on ∼600, 530, 470, 330, 200, 90, and 20 cal yr BP. Synchronous fluctuations in Antarctic ice core chemistry strongly suggest that these variations were linked to changes in the westerlies. Equatorward drift of the westerlies during the wet periods may have influenced Atlantic meridional overturning circulation by restricting marine flow around the tip of Africa. Apparent inconsistencies among some aspects of records from South America, New Zealand and South Africa warn against the simplistic application of single records to the Southern Hemisphere as a whole. Nonetheless, these findings in general do support model projections of increasing aridity in the austral winter rainfall zones with future warming.

  15. Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies

    Science.gov (United States)

    Stager, J. C.; Mayewski, P. A.; White, J.; Chase, B. M.; Neumann, F. H.; Meadows, M. E.; King, C. D.; Dixon, D. A.

    2012-05-01

    The austral westerlies strongly influence precipitation and ocean circulation in the southern temperate zone, with important consequences for cultures and ecosystems. Global climate models anticipate poleward retreat of the austral westerlies with future warming, but the available paleoclimate records that might test these models have been limited to South America and New Zealand, are not fully consistent with each other and may be complicated by influences from other climatic factors. Here we present the first high-resolution diatom and sedimentological records from the winter rainfall region of South Africa, representing precipitation in the equatorward margin of the westerly wind belt during the last 1400 yr. Inferred rainfall was relatively high ∼1400-1200 cal yr BP, decreased until ∼950 cal yr BP, and rose notably through the Little Ice Age with pulses centred on ∼600, 530, 470, 330, 200, 90, and 20 cal yr BP. Synchronous fluctuations in Antarctic ice core chemistry strongly suggest that these variations were linked to changes in the westerlies. Equatorward drift of the westerlies during the wet periods may have influenced Atlantic meridional overturning circulation by restricting marine flow around the tip of Africa. Apparent inconsistencies among some aspects of records from South America, New Zealand and South Africa warn against the simplistic application of single records to the Southern Hemisphere as a whole. Nonetheless, these findings in general do support model projections of increasing aridity in the austral winter rainfall zones with future warming.

  16. Differences of the changes in soil temperature of cold and mid-temperate zones, Northeast China

    Science.gov (United States)

    Yang, Yue; Wu, Zhengfang; He, Hongshi; Du, Haibo; Wang, Lei; Guo, Xiangyu; Zhao, Weihong

    2017-10-01

    Rapid changes in soil temperature are unequivocal under global change, especially in mid-high latitudes. Studies on the relationships between soil temperature and climate system are lacking at regional climatic scale. Here, changes in shallow soil temperature (0, 5, 10, 15, 20 cm), both in the cold temperate zone (CTZ) and the mid-temperate zone (MTZ) in Northeast China, were compared and analyzed using daily data from growing seasons (May to September) from 1964 to 2011. The influences of air temperature and precipitation on soil temperature were analyzed. The results showed that for nearly half a century, the increasing trend of surface soil temperature in the CTZ was lower than that in the MTZ, with + 0.17 and + 0.54 °C/decade, respectively. Air temperature increased faster for the MTZ than the CTZ. Precipitation increased in the CTZ but decreased in the MTZ. Since 1996, the temperature increase and precipitation decrease were more obvious in the MTZ. In summary, given the complex effects of temperature and precipitation, the response of soil temperature was more significant in the MTZ than in the CTZ. These results emphasize the importance of independently researching soil temperature of different climate zones. Susceptibility of soil temperature to global warming will advance our understanding on utilization of climatic resources in the development of agricultural production.

  17. Texture-based segmentation of temperate-zone woodland in panchromatic IKONOS imagery

    Science.gov (United States)

    Gagnon, Langis; Bugnet, Pierre; Cavayas, Francois

    2003-08-01

    We have performed a study to identify optimal texture parameters for woodland segmentation in a highly non-homogeneous urban area from a temperate-zone panchromatic IKONOS image. Texture images are produced with the sum- and difference-histograms depend on two parameters: window size f and displacement step p. The four texture features yielding the best discrimination between classes are the mean, contrast, correlation and standard deviation. The f-p combinations 17-1, 17-2, 35-1 and 35-2 are those which give the best performance, with an average classification rate of 90%.

  18. Rainfall as a trigger for stratification and winter phytoplankton growth in temperate shelf seas

    Science.gov (United States)

    Jardine, Jenny; Palmer, Matthew; Mahaffey, Claire; Holt, Jason; Mellor, Adam; Wakelin, Sarah

    2017-04-01

    We present new data from ocean gliders to investigate physical controls on stratification and phytoplankton dynamics, collected in the Celtic Sea between November 2014 and August 2015 as part of the UK Shelf Sea Biogeochemistry programme. This presentation focuses on the winter period (Jan-March) when the diurnal heating cycle results in regular but weak near surface stratification followed by night-time convection. Despite low light conditions, this daily cycle often promotes a daytime increase in observed chlorophyll fluorescence, indicative of phytoplankton growth. This daily cycle is occasionally interrupted when buoyancy inputs are sufficient to outcompete night-time convection and result in short-term periods of sustained winter stratification, typically lasting 2-3 days. Sustained stratification often coincides with periods of heavy rainfall, suggesting freshwater input from precipitation may play a role on these events by producing a subtle yet significant freshening of the surface layer of the order of 0.005 PSU. Comparing rainfall estimates with observed salinity changes confirms rainfall to often be the initiator of these winter stratification periods. As winter winds subside and solar heating increases towards spring, the water column becomes more susceptible to periods of halo-stratification, such that heavy rainfall during the winter-spring transition is likely to promote sustained stratification. The timing and extent of a heavy rainfall event in March 2015 does suggest it may be the critical trigger for shelf-wide stratification that eventually instigates the spring bloom. We propose that the timing of these downpours relative to the daily heating cycle can be a triggering mechanism for both short term and seasonal stratification in shelf seas, and so play a critical role in winter and early spring phytoplankton growth and the shelf sea carbon cycle. We further test the importance of this process using historical data, and results from the NEMO-AMM7

  19. Divergence in strategies for coping with winter embolism among co-occurring temperate tree species: the role of positive xylem pressure, wood type and tree stature

    Science.gov (United States)

    Cun-Yang Niu; Frederick C. Meinzer; Guang-You. Hao

    2017-01-01

    1. In temperate ecosystems, freeze-thaw events are an important environmental stress that can induce severe xylem embolism (i.e. clogging of conduits by air bubbles) in overwintering organs of trees. However, no comparative studies of different adaptive strategies among sympatric tree species for coping with winter embolism have examined the potential role of the...

  20. Ecological impacts of winter water level drawdowns on lake littoral zones: A review

    Science.gov (United States)

    Roy, Allison

    2017-01-01

    Freshwater littoral zones harbor diverse ecological communities and serve numerous ecosystem functions that are controlled, in part, by natural water level fluctuations. However, human alteration of lake hydrologic regimes beyond natural fluctuations threaten littoral zone ecological integrity. One type of hydrologic alteration in lakes is winter water level drawdowns, which are frequently employed for hydropower, flood control, and macrophyte control, among other purposes. Here, we synthesize the abiotic and biotic responses to annual and novel winter water level drawdowns in littoral zones of lakes and reservoirs. The dewatering, freezing, and increased erosion of exposed lakebeds drive changes in the littoral zone. Shoreline-specific physicochemical conditions such as littoral slope and shoreline exposure further induce modifications. Loss of fine sediment decreases nutrient availability over time, but desiccation may promote a temporary nutrient pulse upon re-inundation. Annual winter drawdowns can decrease taxonomic richness of macrophytes and benthic invertebrates and shift assemblage composition to favor taxa with r-selected life history strategies and with functional traits resistant to direct and indirect drawdown effects. Fish assemblages, though less directly affected by winter drawdowns (except where there is critically low dissolved oxygen), experience negative effects via indirect pathways like decreased food resources and spawning habitat. We identify eight general research gaps to guide future research that could improve our understanding about the complex effects of winter drawdowns on littoral zone ecology.

  1. Heterogeneous responses of temperate-zone amphibian populations to climate change complicates conservation planning

    Science.gov (United States)

    Muths, Erin L.; Chambert, Thierry A.; Schmidt, B. R.; Miller, D. A. W.; Hossack, Blake R.; Joly, P.; Grolet, O.; Green, D. M.; Pilliod, David; Cheylan, M.; Fisher, Robert N.; McCaffery, R. M.; Adams, M. J.; Palen, W. J.; Arntzen, J. W.; Garwood, J.; Fellers, Gary M.; Thirion, J. M.; Grant, Evan H. Campbell; Besnard, A.

    2017-01-01

    The pervasive and unabated nature of global amphibian declines suggests common demographic responses to a given driver, and quantification of major drivers and responses could inform broad-scale conservation actions. We explored the influence of climate on demographic parameters (i.e., changes in the probabilities of survival and recruitment) using 31 datasets from temperate zone amphibian populations (North America and Europe) with more than a decade of observations each. There was evidence for an influence of climate on population demographic rates, but the direction and magnitude of responses to climate drivers was highly variable among taxa and among populations within taxa. These results reveal that climate drivers interact with variation in life-history traits and population-specific attributes resulting in a diversity of responses. This heterogeneity complicates the identification of conservation ‘rules of thumb’ for these taxa, and supports the notion of local focus as the most effective approach to overcome global-scale conservation challenges.

  2. Cytotoxic Meroterpenoids with Rare Skeletons from Psidium guajava Cultivated in Temperate Zone

    Science.gov (United States)

    Qin, Xu-Jie; Yan, Huan; Ni, Wei; Yu, Mu-Yuan; Khan, Afsar; Liu, Hui; Zhang, Hong-Xia; He, Li; Hao, Xiao-Jiang; di, Ying-Tong; Liu, Hai-Yang

    2016-09-01

    Three new meroterpenoids, guajavadials A-C (1-3), were isolated from Psidium guajava cultivated in temperate zone. Their structures were established by extensive spectroscopic evidence and electronic circular dichroism (ECD) calculations. Guajavadial A (1) represents a novel skeleton of the 3,5-diformylbenzyl phloroglucinol-coupled monoterpenoid, while guajavadials B (2) and C (3) are new adducts of the 3,5-diformylbenzyl phloroglucinol and a sesquiterpene with different coupling models. The plausible biosynthetic pathways as well as antimicrobial and cytotoxic activities of these meroterpenoids are also discussed. All these isolates exhibited moderate cytotoxicities against five human cancer cell lines, with 3 being most effective with an IC50 value of 3.54 μM toward SMMC-7721 cell lines.

  3. Microclimate buffering of winter temperatures by pine stumps in a temperate forest

    Science.gov (United States)

    Walczyńska, Aleksandra; Kapusta, Paweł

    2017-03-01

    In the presented study we evaluated the role of wood in buffering its inhabitants against winter temperatures. We followed the microscale temperature patterns inside and outside decaying pine stumps during two winter periods. We analyzed the data by extracting the minimum, maximum and mean temperatures for the episodes of snow, frost or no frost. We compared the temperature variation by applying an absolute values calculation (=modulus) for the subsequent measurements. Finally, we tested the buffering effect of the horizontal depth inside the stumps by comparing the pattern for 5 and 15 cm depths. The results show that (1) the minimum temperature was significantly higher inside than outside the stumps, while temperature variation tended to be larger outside than inside, (2) the dynamics of temperature varied between weather episodes, i.e. the periods characterized by the presence/absence of snow and of frost, (3) the minimum temperature inside the stumps increased with the horizontal depth, while temperature variation decreased. The results presented are the first truly microclimatic data on wood buffering and they are important for the understanding of the possible effects of climate change on the thermal relationships at the microscale.

  4. Conference on the Rehabilitation of Severely Damaged Land and Freshwater Ecosystems in Temperate Zones

    CERN Document Server

    Woodman, M

    1978-01-01

    This volume contains the papers presented at a conference on "The rehabilitation of severely damaged land and freshwater eco­ systems in temperate zones", held at Reykjavik, Iceland, from 4th to 11th July, 1976. The meeting was held under the auspices of the Ecosciences Panel of the N.A.T.O. Science Committee, and the organising expenses and greater part of the expenses of the speakers and chairmen were provided by N.A.T.O. The scientific programme was planned by M. W. Holdgate and M. J. Woodman, in consultation with numerous colleagues, and especially with the Administrative Director of the Conference in Iceland, Dr. Sturla Fridriksson. Iceland proved a particularly suitable location for such a Conference. Geologically, it is one of the youngest countries 1n the world, owing its origin to the up-welling of volcanic rock along the spreading zone of the mid-Atlantic ridge within the past 20 million years. Its structure, northern oceanic situation, recent glaciation and continuing volcanic activity make it dis...

  5. Effects of winter temperature and summer drought on net ecosystem exchange of CO2 in a temperate peatland

    Science.gov (United States)

    Helfter, Carole; Campbell, Claire; Dinsmore, Kerry; Drewer, Julia; Coyle, Mhairi; Anderson, Margaret; Skiba, Ute; Nemitz, Eiko; Billett, Michael; Sutton, Mark

    2014-05-01

    Northern peatlands are one of the most important global sinks of atmospheric carbon dioxide (CO2); their ability to sequester C is a natural feedback mechanism controlled by climatic variables such as precipitation, temperature, length of growing season and period of snow cover. In the UK it has been predicted that peatlands could become a net source of carbon in response to climate change with climate models predicting a rise in global temperature of ca. 3oC between 1961-1990 and 2100. Land-atmosphere exchange of CO2in peatlands exhibits marked seasonal and inter-annual variations, which have significant short- and long-term effects on carbon sink strength. Net ecosystem exchange (NEE) of CO2 has been measured continuously by eddy-covariance (EC) at Auchencorth Moss (55° 47'32 N, 3° 14'35 W, 267 m a.s.l.), a temperate peatland in central Scotland, since 2002. Auchencorth Moss is a low-lying, ombrotrophic peatland situated ca. 20 km south-west of Edinburgh. Peat depth ranges from 5 m and the site has a mean annual precipitation of 1155 mm. The vegetation present within the flux measurement footprint comprises mixed grass species, heather and substantial areas of moss species (Sphagnum spp. and Polytrichum spp.). The EC system consists of a LiCOR 7000 closed-path infrared gas analyser for the simultaneous measurement of CO2 and water vapour and of a Gill Windmaster Pro ultrasonic anemometer. Over the 10 year period, the site was a consistent yet variable sink of CO2 ranging from -34.1 to -135.9 g CO2-C m-2 yr-1 (mean of -69.1 ± 33.6 g CO2-C m-2 yr-1). Inter-annual variability in NEE was positively correlated to the length of the growing seasons and mean winter air temperature explained 93% of the variability in summertime sink strength, indicating a phenological memory-effect. Plant development and productivity were stunted by colder winters causing a net reduction in the annual carbon sink strength of this peatland where autotrophic processes are thought to be

  6. Effects of storm runoff on the thermal regime and water quality of a deep, stratified reservoir in a temperate monsoon zone, in Northwest China

    NARCIS (Netherlands)

    Huanga, Tinglin; Xuan Li,; Rijnaarts, H.H.M.; Grotenhuis, J.T.C.; Weixing Ma,; Xin Sun,; Jinlan Xu,

    2014-01-01

    Jinpen Reservoir is a deep, stratified reservoir in Shaanxi province, located in a warm temperate zone of Northwest China. Influenced by a temperate monsoon climate, more than 60% of the annual precipitation is concentrated from late summer to autumn (July–September). In recent years, extreme

  7. The northern limit of corals of the genus Acropora in temperate zones is determined by their resilience to cold bleaching.

    Science.gov (United States)

    Higuchi, Tomihiko; Agostini, Sylvain; Casareto, Beatriz Estela; Suzuki, Yoshimi; Yuyama, Ikuko

    2015-12-18

    The distribution of corals in Japan covers a wide range of latitudes, encompassing tropical to temperate zones. However, coral communities in temperate zones contain only a small subset of species. Among the parameters that determine the distribution of corals, temperature plays an important role. We tested the resilience to cold stress of three coral species belonging to the genus Acropora in incubation experiments. Acropora pruinosa, which is the northernmost of the three species, bleached at 13 °C, but recovered once temperatures were increased. The two other species, A. hyacinthus and A. solitaryensis, which has a more southerly range than A. pruinosa, died rapidly after bleaching at 13 °C. The physiological effects of cold bleaching on the corals included decreased rates of photosynthesis, respiration, and calcification, similar to the physiological effects observed with bleaching due to high temperature stress. Contrasting hot bleaching, no increases in antioxidant enzyme activities were observed, suggesting that reactive oxygen species play a less important role in bleaching under cold stress. These results confirmed the importance of resilience to cold stress in determining the distribution and northern limits of coral species, as cold events causing coral bleaching and high mortality occur regularly in temperate zones.

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

    Directory of Open Access Journals (Sweden)

    Suresh D Desai

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

  9. Challenges in the nutrition and management of herbivores in the temperate zone.

    Science.gov (United States)

    van Vuuren, A M; Chilibroste, P

    2013-03-01

    The expected higher global demand for animal proteins and the competition for starch and sugars between food, fuel and feed seem to favour herbivores that convert solar energy captured in fibrous plants into animal products. However, the required higher production level of herbivores questions the sustainability of this conversion. An increase in herbivore production can be achieved by increasing the number of animals associated with the increasing demand of plant biomass or by improving the efficiency with which plant biomass is converted into meat and milk. The potential to increase food production by cattle, the main food-producing herbivore in the temperate zones outside China, was considered in three production systems: grassland-based, mixed rain-fed and mixed irrigated systems. The potential to increase plant biomass production in grassland-based systems seems limited, unless fertiliser is imported in large quantities and crop production is increased, sacrificing valuable, high-quality grasslands, which often conflicts with sustainable production methods. Also, in mixed systems with high inputs of fertiliser or water, improvements in plant biomass production seem marginal and the main challenges for these systems are in breeding high-quality plant biomass at lower levels of fertiliser and the use of new co-products from food processing and bio-based economies. Consequently, the main challenge in herbivore nutrition management is to improve the efficiency of plant biomass utilisation. Stocking rate management along with seasonal variation in the grazing capacity of grasslands and moderate use of fertiliser may increase meat production in grassland-based systems by 400%. Improving plant biomass utilisation in the more industrialised mixed rain-fed systems seems possible by better feed storage technologies and for dairy cattle by improving animal health and lifetime production level. Managing the transition period seems crucial to achieve more sustainable mixed

  10. Winter energy behaviour in multi-family block buildings in a temperate-cold climate in Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Filippin, C. [CONICET - CC302, Santa Rosa, 6300 La Pampa (Argentina); Larsen, S. Flores [CONICET - CC302, Santa Rosa, 6300 La Pampa (Argentina); INENCO - Instituto de Investigaciones en Energias No Convencionales, U.N.Sa., CONICET, Avda. Bolivia 5150 - CP 4400, Salta Capital (Argentina); Mercado, V. [LAHV-Laboratorio de Ambienet Humano y Vivienda (INCIHUSA-CCT-CONICET) (Argentina)

    2011-01-15

    This paper analyzes the thermal and energy behaviour of apartments in three-story block buildings located along a NE-SW axis (azimuth = 120 ) in a temperate-cold climate (latitude: 36 57'; longitude: 64 27') in the city of Santa Rosa, La Pampa, central Argentina. Four apartments had been monitored during May and June 2009. Three of them are located in Block 126. Two of these apartments face South: 15 and 23 on the SE end, ground and first floor, respectively; 18 faces N on the second floor. Finally apartment, 12 is located in Block 374, on the first floor, faces N and shows a carpentry-closed balcony. The purpose of this work is - to study the evolution of the indoor temperature in each apartment; to analyze energy consumption and comfort conditions; to study energy potential and energy intervention in order to reduce energy consumption; to analyze bioclimatic alternatives feasibility and the possibility to extrapolate results to all blocks. On the basis of the analysis of natural gas historical consumption records, results showed that regarding heating energy consumption during the period May-June, Apartment 12, facing N, with its only bedroom facing NW and its carpentry-closed, transparent glass balcony, presented a mean temperature of 21.2 C, using a halogen heater for 6 h/day between 9 pm and 2 am (0.16 kWh/day/m{sup 2}). Apartment 15, on the SE end, first floor of the block consumed 22.5 kWh/day (0.43 kWh/day/m{sup 2}) (mean temperature = 22.2 C). Apartment 23, located on the second and top floor (on top of Apartment 15) with higher energy loss, consumed 28 kWh/day (0.54 kWh/day/m{sup 2}) (mean temperature 23.7 C). Apartment 18, also on the second floor and facing N, located in the centre and with its only bedroom facing SE, consumed 18.8 kWh/day (0.48 kWh/day/m{sup 2}) (mean temperature = 22.3 C). Apartment 23, with higher thermal loss through its envelope, but with heat transfer from the apartment located below, is the one that showed the highest

  11. Biological, chemical and physical characteristics of downwelling and upwelling zones in the hyporheic zone of a north-temperate stream

    NARCIS (Netherlands)

    Franken, R.J.M.; Storey, R.G.; Williams, D.D.

    2001-01-01

    Along a single stream riffle, there is a typical flow pattern in which surface water enters the hyporheic zone in a downwelling zone at the head of the riffle and hyporheic water returns to the stream surface in an upwelling zone at the tail of the riffle. Distinct patterns of physical and chemical

  12. Dynamics of low-temperature acclimation in temperate and boreal conifer foliage in a mild winter climate

    Science.gov (United States)

    G. Richard Strimbeck; Trygve D. Kjellsen; Paul G. Schaberg; Paula F. Murakami

    2008-01-01

    To provide baseline data for physiological studies of extreme low-temperature (LT) tolerance in boreal conifers, we profiled LT stress responses, liquid nitrogen (LN2)-quench tolerance, and sugar concentrations in foliage of boreal-temperate species pairs in the genera Abies, Picea and Pinus, growing in an...

  13. Fresh Water Lens Persistence and Root Zone Salinization Hazard Under Temperate Climate

    NARCIS (Netherlands)

    Stofberg, Sija F.; Oude Essink, G.H.P.; Pauw, Pieter S.; Louw, de Perry G.B.; Leijnse, Anton; Zee, van der Sjoerd E.A.T.M.

    2017-01-01

    In low lying deltaic areas in temperate climates, groundwater can be brackish to saline at shallow depth, even with a yearly rainfall excess. For primary production in horticulture, agriculture, and terrestrial nature areas, the fresh water availability may be restricted to so-called fresh water

  14. Fresh Water Lens Persistence and Root Zone Salinization Hazard Under Temperate Climate

    NARCIS (Netherlands)

    Stofberg, Sija F.; Oude Essink, G.H.P.; Pauw, Pieter S.; De Louw, Perry G.B.; Leijnse, A.; van der Zee, Sjoerd E.A.T.M.

    2016-01-01

    In low lying deltaic areas in temperate climates, groundwater can be brackish to saline at shallow depth, even with a yearly rainfall excess. For primary production in horticulture, agriculture, and terrestrial nature areas, the fresh water availability may be restricted to so-called fresh water

  15. The hyporheic zone as a source of dissolved organic carbon and carbon gases to a temperate forested stream

    Science.gov (United States)

    Schindler, J.E.; Krabbenhoft, D.P.

    1998-01-01

    The objective of this study was to examine chemical changes in porewaters that occur over small scales (cm) as groundwater flows through the hyporheic zone and discharges to a stream in a temperate forest of northern Wisconsin. Hyporheic-zone porewaters were sampled at discrete depths of 2, 10, 15, 61, and 183 cm at three study sites in the study basin. Chemical profiles of dissolved organic carbon (DOC), CO2, CH4, and pH show dramatic changes between 61 cm sediment depth and the water-sediment interface. Unless discrete samples at small depth intervals are taken, these chemical profiles are not accounted for. Similar trends were observed at the three study locations, despite each site having very different hydraulic-flow regimes. Increases in DOC concentration by an order of magnitude from 61 to 15 cm depth with a corresponding decrease in pH and rapid decreases in the molecular weight of the DOC suggest that aliphatic compounds (likely organic acids) are being generated in the hyporheic zone. Estimated efflux rates of DOC, CO2, and CH4 to the stream are 6.2, 0.79, 0.13 moles m2 d-1, respectively, with the vast majority of these materials produced in the hyporheic zone. Very little of these materials are accounted for by sampling stream water, suggesting rapid uptake and/or volatilization.

  16. The winter pack-ice zone provides a sheltered but food-poor habitat for larval Antarctic krill

    OpenAIRE

    Meyer, Bettina; Freier, Ulrich; Grimm, Volker; Groeneveld, Jürgen; Hunt, Brian P. V.; Kerwath, Sven; King, Rob; Klaas, Christine; Pakhomov, Evgeny A.; Meiners, Klaus M.; Melbourne-Thomas, Jessica; Murphy, Eugene J.; Thorpe, Sally E.; Stammerjohn, Sharon; Wolf-Gladrow, Dieter

    2017-01-01

    A dominant Antarctic ecological paradigm suggests that winter sea ice is generally the main feeding ground for krill larvae. Observations from our winter cruise to the southwest Atlantic sector of the Southern Ocean contradict this view and present the first evidence that the pack-ice zone is a food-poor habitat for larval development. In contrast, the more open marginal ice zone provides a more favourable food environment for high larval krill growth rates. We found that complex under-ice ha...

  17. Winter warming delays dormancy release, advances budburst, alters carbohydrate metabolism and reduces yield in a temperate shrub

    DEFF Research Database (Denmark)

    Pagter, Majken; Andersen, Uffe Brandt; Andersen, Lillie

    2015-01-01

    winter warming modifies phenological traits in a woody perennial known to have a large chilling requirement and to be sensitive to spring frost. Warming delayed dormancy release more in the cultivar ‘Narve Viking’ than in the cultivar ‘Titania’, but advanced budburst and flowering predominantly...

  18. The impact of winter and spring temperatures on temperate tree budburst dates: results from an experimental climate manipulation.

    Directory of Open Access Journals (Sweden)

    Yongshuo H Fu

    Full Text Available Budburst phenology is a key driver of ecosystem structure and functioning, and it is sensitive to global change. Both cold winter temperatures (chilling and spring warming (forcing are important for budburst. Future climate warming is expected to have a contrasting effect on chilling and forcing, and subsequently to have a non-linear effect on budburst timing. To clarify the different effects of warming during chilling and forcing phases of budburst phenology in deciduous trees, (i we conducted a temperature manipulation experiment, with separate winter and spring warming treatments on well irrigated and fertilized saplings of beech, birch and oak, and (ii we analyzed the observations with five temperature-based budburst models (Thermal Time model, Parallel model, Sequential model, Alternating model, and Unified model. The results show that both winter warming and spring warming significantly advanced budburst date, with the combination of winter plus spring warming accelerating budburst most. As expected, all three species were more sensitive to spring warming than to winter warming. Although the different chilling requirement, the warming sensitivity was not significantly different among the studied species. Model evaluation showed that both one- and two- phase models (without and with chilling, respectively are able to accurately predict budburst. For beech, the Sequential model reproduced budburst dates best. For oak and birch, both Sequential model and the Thermal Time model yielded good fit with the data but the latter was slightly better in case of high parameter uncertainty. However, for late-flushing species, the Sequential model is likely be the most appropriate to predict budburst data in a future warmer climate.

  19. Assessment of Natural Ventilation Potential for Residential Buildings across Different Climate Zones in Australia

    OpenAIRE

    Zijing Tan; Xiang Deng

    2017-01-01

    In this study, the natural ventilation potential of residential buildings was numerically investigated based on a typical single-story house in the three most populous climate zones in Australia. Simulations using the commercial simulation software TRNSYS (Transient System Simulation Tool) were performed for all seasons in three representative cities, i.e., Darwin for the hot humid summer and warm winter zone, Sydney for the mild temperate zone, and Melbourne for the cool temperate zone. A na...

  20. Effect of low winter temperatures on milk production of dairy cows grazed on farms in a warm temperate climate (Australia)

    Science.gov (United States)

    Dragovich, D.

    1980-06-01

    Two-day milk production figures for dairymen at Armidale (31° S Lat.) and Goulburn (35° S Lat.), Australia, were compared with minimum daily temperatures. Comparisons were made between production levels on days with temperatures above and below 0°C, and between days with varying intensities of cold: differences in production were minor. The infrequent, more prolonged periods of cold weather (“cold” being days on which the minimum temperature was below 0°C) were also associated with only very slight reductions in milk output; and the most pronounced decline in production was not attributable to low temperatures. Although short-term fluctuations in output were not related to low temperature events or low temperatures in combination with rain, thermal stress on plant growth during winter contributed to a seasonal downturn in production and below-average annual milk yields in areas with low winter temperatures.

  1. Recovery of coastal ecosystems after large tsunamis in various climatic zones - review of cases from tropical, temperate and polar zones (Invited)

    Science.gov (United States)

    Szczucinski, W.

    2013-12-01

    Large tsunamis cause significant changes in coastal ecosystems. They include modifications in shoreline position, sediment erosion and deposition, new initial soil formation, salination of soils and waters, removal of vegetation, as well as direct impact on humans and infrastructure. The processes and rate of coastal zone recovery from large tsunamis has been little studied but during the last decade a noteworthy progress has been made. This study focus on comparison of recovery processes in various climatic zones, namely in monsoonal-tropical, temperate and polar zone. It is based on own observation and monitoring in areas affected by 2004 Indian Ocean Tsunami in Thailand, 2011 Tohoku-oki tsunami in Japan and 2000 Paatuut landslide-generated tsunami in Vaigat Strait (west Greenland), as well as on review of published studies from those areas. The particular focus is on physical and biological recoveries of beaches, recovery of coastal vegetation, new soil formation in eroded areas and those covered by tsunami deposits, marine salt removal from soils, surface- and groundwater, as well as landscape adjustment after the tsunamis. The beach zone - typically the most tsunami-eroded zone, has been recovered already within weeks to months and has been observed to be in the pre-tsunami equilibrium stage within one year in all the climate zones, except for sediment-starved environments. The existing data on beach ecosystems point also to relatively fast recovery of meio- and macrofauna (within weeks to several months). The recovery of coastal vegetation depends on the rate of salt removal from soils or on the rate of soil formation in case of its erosion or burial by tsunami deposits. The salt removal have been observed to depend mainly on precipitation and effective water drainage. In tropical climate with seasonal rainfall of more 3000 mm the salt removal was fast, however, in temperate climate with lower precipitation and flat topography the salinities still exceeded

  2. Intraseasonal variability of the Atlantic Intertropical Convergence Zone during austral summer and winter

    Science.gov (United States)

    Tomaziello, Ana Carolina Nóbile; Carvalho, Leila M. V.; Gandu, Adilson W.

    2016-09-01

    The Atlantic Intertropical Convergence Zone (A-ITCZ) exhibits variations on several time-scales and plays a crucial role in precipitation regimes of northern South America and western Africa. Here we investigate the variability of the A-ITCZ on intraseasonal time-scales during austral summer (November-March) and winter (May-September) based on a multivariate index that describes the main atmospheric features of the A-ITCZ and retains its variability on interannual, semiannual, and intraseasonal time-scales. This index is the time coefficient of the first combined empirical orthogonal function mode of anomalies (annual cycle removed) of precipitation, and zonal and meridional wind components at 850 hPa from the climate forecast system reanalysis (1979-2010). We examine associations between the intraseasonal variability of the A-ITCZ and the activity of the Madden-Julian oscillation (MJO). We show that during austral summer intraseasonal variability of the A-ITCZ is associated with a Rossby wave train in the Northern Hemisphere. In austral winter this variability is associated with the propagation of a Rossby wave in the Southern Hemisphere consistent with the Pacific-South American pattern. Moreover, we show that intense A-ITCZ events on intraseasonal time-scales are more frequent during the phase of MJO characterized by convection over western Pacific and suppression over the Indian Ocean. These teleconnection patterns induce anomalies in the trade winds and upper level divergence over the equatorial Atlantic that modulate the intensity of the A-ITCZ.

  3. The nursery role of a sheltered surf-zone in warm-temperate ...

    African Journals Online (AJOL)

    Marine fish nurseries such as surf-zones have usually been classified as nurseries based solely on the density of pre-adult fish, yet the full suite of developmental stages are seldom assessed because of difficulties associated with sampling these habitats. The larval and early juvenile fish assemblage was studied in a ...

  4. Biological soil crusts are the main contributor to winter soil respiration in a temperate desert ecosystem of China

    Science.gov (United States)

    He, M. Z.

    2012-04-01

    Aims Biological soil crusts (BSCs) are a key biotic component of desert ecosystems worldwide. However, most studies carried out to date on carbon (fluxes) in these ecosystems, such as soil respiration (RS), have neglected them. Also, winter RS is reported to be a significant component of annual carbon budget in other ecosystems, however, we have less knowledge about winter RS of BSCs in winter and its contribution to carbon cycle in desert regions. Therefore, the specific objectives of this study were to: (i) quantify the effects of different BSCs types (moss crust, algae crust, physical crust) on the winter RS; (ii) explore relationships of RS against soil temperature and water content for different BSCs, and (iii) assess the relative contribution of BSCs to the annual amount of C released by RS at desert ecosystem level. Methods Site Description The study sites are located at the southeast fringe of the Tengger Desert in the Shapotou region of the Ningxia Hui Autonomous Region [37°32'N and 105°02'E, at 1340 m above mean sea level (a.m.s.l.)], western China. The mean daily temperature in January is -6.9°C , while it is 24.3°C in July. The mean annual precipitation is 186 mm, approximately 80% of which falls between May and September. The annual potential evaporation is 2800 mm. The landscape of the Shapotou region is characterized by large and dense reticulate barchans chains of sand dunes that migrate south-eastward at a velocity of 3-6 m per year. The soil is loose, infertile and mobile and can thus be classified as orthic sierozem and Aeolian sandy soil. Additionally, the soil has a consistent gravimetric water content that ranges from 3 to 4%. The groundwater in the study area is too deep (>60 m) to support large areas of the native vegetation cover; therefore, precipitation is usually the only source of freshwater. The predominant native plants are Hedysarum scoparium Fisch. and Agriophyllum squarrosum Moq., Psammochloa cillosa Bor, which scattered

  5. Wintering seabirds in West Africa: foraging hotspots off Western ...

    African Journals Online (AJOL)

    This paper describes the distribution of wintering seabirds in the context of fisheries and hydrography. The avifauna was dominated by surface-feeding and shallow plunge-diving, often planktivorous, seabirds, originating from West Palaearctic breeding grounds (Arctic, subarctic and temperate zones). Many seabirds were ...

  6. Tempering-Induced Microstructural Changes in the Weld Heat-Affected Zone of 9 to 12 Pct Cr Steels and Their Influence on Sliding Wear

    Science.gov (United States)

    Velkavrh, Igor; Kafexhiu, Fevzi; Klien, Stefan; Diem, Alexander; Podgornik, Bojan

    2017-01-01

    Increasing amount of tribological applications is working under alternating high/low temperature conditions where the material is subjected to temperature fatigue mechanisms such as creep, softening due to annealing, and at the same time must withstand mechanical wear due to sliding contact with pairing bodies. Steam turbine valves, gate valves, valve heads, stems, seats and bushings, and contacting surfaces of the carrier elements are some examples of such applications. The purpose of the present study is to evaluate the potential of X20 and P91 steels as materials for applications operating under combined effect of mechanical wear and alternating high/low temperature conditions. It was focused on how the microstructural changes occurring in the weld zone affect the wear properties of the selected materials. Generally, with longer tempering time and higher tempering temperature, the number of carbide precipitates decreased, while their relative spacing increased. Before tempering, the morphology of the steel matrix (grain size, microstructure homogeneity) governed the wear resistance of both steels, while after tempering wear response was determined by the combination of the number and the size of carbide particles. After tempering, in X20 steel larger number of stable M23C6 carbides was observed as compared with P91 steel, resulting in lower wear rates. It was observed that for both steels, a similar combination of number density and size distribution of carbide particles provided the highest wear resistance.

  7. Holocene climate variability in the winter rainfall zone of South Africa

    Directory of Open Access Journals (Sweden)

    S. Weldeab

    2013-10-01

    Full Text Available We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes, grain size of terrigenous fraction, and δ18O and δ13C in tests of Neogloboquadrina pachyderma (sinistral from a marine sediment sequence recovered off the Orange River. The records reveal coherent patterns of variability that reflect changes in wind strength, precipitation over the river catchments, and upwelling of cold and nutrient-rich coastal waters off western South Africa. The wettest episode of the Holocene in the winter rainfall zone (WRZ of South Africa occurred during the "Little Ice Age" (700–100 cal years BP most likely in response to a northward shift of the austral westerlies. Wet phases and strengthened coastal water upwellings are companied by a decrease of Agulhas water leakage into the South Atlantic and a reduced dust incursion over Antarctica, as indicated in previous studies. A continuous aridification trend in the WRZ and a weakening of the southern Benguela Upwelling System (BUS between 9000 and 5500 cal years BP parallel with increase of dust deposition over Antarctica and an enhanced leakage of warm Agulhas water into the eastern South Atlantic. The temporal relationship between precipitation changes in the WRZ, the thermal state of the coastal surface water, and leakage of warm water in the South Atlantic, and variation of dust incursion over Antarctica suggests a causal link that most likely was related to latitudinal shifts of the Southern Hemisphere westerlies. Our results of the mid-Holocene time interval may serve as an analogue to a possible long-term consequence of the current and future southward shift of the westerlies. Furthermore, warming of the coastal surface water as a result of warm Agulhas water incursion into the southern BUS may affect coastal fog formation.

  8. Holocene climate variability in the winter rainfall zone of South Africa

    Science.gov (United States)

    Weldeab, S.; Stuut, J.-B. W.; Schneider, R. R.; Siebel, W.

    2013-10-01

    We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes, grain size of terrigenous fraction, and δ18O and δ13C in tests of Neogloboquadrina pachyderma (sinistral) from a marine sediment sequence recovered off the Orange River. The records reveal coherent patterns of variability that reflect changes in wind strength, precipitation over the river catchments, and upwelling of cold and nutrient-rich coastal waters off western South Africa. The wettest episode of the Holocene in the winter rainfall zone (WRZ) of South Africa occurred during the "Little Ice Age" (700-100 cal years BP) most likely in response to a northward shift of the austral westerlies. Wet phases and strengthened coastal water upwellings are companied by a decrease of Agulhas water leakage into the South Atlantic and a reduced dust incursion over Antarctica, as indicated in previous studies. A continuous aridification trend in the WRZ and a weakening of the southern Benguela Upwelling System (BUS) between 9000 and 5500 cal years BP parallel with increase of dust deposition over Antarctica and an enhanced leakage of warm Agulhas water into the eastern South Atlantic. The temporal relationship between precipitation changes in the WRZ, the thermal state of the coastal surface water, and leakage of warm water in the South Atlantic, and variation of dust incursion over Antarctica suggests a causal link that most likely was related to latitudinal shifts of the Southern Hemisphere westerlies. Our results of the mid-Holocene time interval may serve as an analogue to a possible long-term consequence of the current and future southward shift of the westerlies. Furthermore, warming of the coastal surface water as a result of warm Agulhas water incursion into the southern BUS may affect coastal fog formation.

  9. Seasonality in a temperate zone bird can be entrained by near equatorial photoperiods.

    Science.gov (United States)

    Dawson, Alistair

    2007-03-07

    Birds use photoperiod to control the time of breeding and moult. However, it is unclear whether responses are dependent on absolute photoperiod, the direction and rate of change in photoperiod, or if photoperiod entrains a circannual clock. If starlings (Sturnus vulgaris) are kept on a constant photoperiod of 12h light:12h darkness per day (12L:12D), then they can show repeated cycles of gonadal maturation, regression and moult, which is evidence for a circannual clock. In this study, starlings kept on constant 11.5L:12.5D for 4 years or 12.5L:11.5D for 3 years showed no circannual cycles in gonadal maturation or moult. So, if there is a circannual clock, it is overridden by a modest deviation in photoperiod from 12L:12D. The responses to 11.5L:12.5D and 12.5L:11.5D were very different, the former perceived as a short photoperiod (birds were photosensitive for most of the time) and the latter as a long photoperiod (birds remained permanently photorefractory). Starlings were then kept on a schedule which ranged from 11.5L:12.5D in mid-winter to 12.5L:11.5D in mid-summer (simulating the annual cycle at 9 degrees N) for 3 years. These birds entrained precisely to calendar time and changes in testicular size and moult were similar to those of birds under a simulated cycle at 52 degrees N. These data show that birds are very sensitive to changes in photoperiod but that they do not simply respond to absolute photoperiod nor can they rely on a circannual clock. Instead, birds appear to respond to the shape of the annual change in photoperiod. This proximate control could operate from near equatorial latitudes and would account for similar seasonal timing in individuals of a species over a wide range of latitudes.

  10. Genetic diversity of Persian walnut (Juglans regia) in the cold-temperate zone of the United States and Europe

    Science.gov (United States)

    Aziz Ebrahimi; AbdolKarim Zarei; James R. McKenna; Geza Bujdoso; Keith E. Woeste

    2017-01-01

    We compared the genetic diversity of Juglans regia L. growing in the cold temperate region of the eastern U.S. with J. regia growing in the cold-temperate and Mediterranean regions of Europe. Ten microsatel-lite (SSR) loci were used to assess the genetic relationships among 114 total trees originating from the Midwestern USA (n...

  11. Influence of orientation, glazing proportion and zone aspect ratio on the thermal performance of buildings during the winter period.

    Science.gov (United States)

    Zenginis, Dimitrios G; Kontoleon, Karolos J

    2017-07-25

    The objective of this study is to assess the effect of orientation, glazing proportion and aspect ratio of building zones on heat fluxes through their surfaces, under specific environmental conditions. The investigation is carried out for thermally-insulated building zones with a varying facade orientation corresponding to each cardinal point, during the winter period in the northern Greek region. For this purpose, three glazing-to-facade ratios (GR) are taken into account; along with the glazing ratio the influence of the glazing U value is also considered. Regarding the impact of the fenestration layout geometry, five different building aspect ratio profiles are examined. Thermal fluxes are assessed for two different indoor temperature settings, while the operation of the heating unit is assumed to be continuous. The transient thermal analysis with its mathematical formulation and solution are based on the thermal-network modelling approach, while the solar heat gain through glazing relies on the sunlit-pattern approach; in this way, the stricken by the solar rays glazing area is projected onto any interior surfaces to form the so called "sunlit" areas. As the orientation, glazing proportion and aspect ratio of the building zone vary, so do the sizes and shapes of the illuminated "sunlit" areas. Accordingly, the delivered into the zone direct solar energy and its diffused and ground reflected components can be determined. The adopted methodology provides a more accurate determination of solar heat gain with respect to glazing proportion and orientation as well as zone aspect ratio. With regard to surface orientation, glazing proportion and aspect ratio, computer results demonstrate the improvement of the thermal performance for a building zone with a south oriented glazing surface, as well as the deterioration for the other surface orientations; relative increases/decreases in the energy fluxes of a rectangular shaped building zone compared to a square

  12. The winter pack-ice zone provides a sheltered but food-poor habitat for larval Antarctic krill.

    Science.gov (United States)

    Meyer, Bettina; Freier, Ulrich; Grimm, Volker; Groeneveld, Jürgen; Hunt, Brian P V; Kerwath, Sven; King, Rob; Klaas, Christine; Pakhomov, Evgeny; Meiners, Klaus M; Melbourne-Thomas, Jessica; Murphy, Eugene J; Thorpe, Sally E; Stammerjohn, Sharon; Wolf-Gladrow, Dieter; Auerswald, Lutz; Götz, Albrecht; Halbach, Laura; Jarman, Simon; Kawaguchi, So; Krumpen, Thomas; Nehrke, Gernot; Ricker, Robert; Sumner, Michael; Teschke, Mathias; Trebilco, Rowan; Yilmaz, Noyan I

    2017-12-01

    A dominant Antarctic ecological paradigm suggests that winter sea ice is generally the main feeding ground for krill larvae. Observations from our winter cruise to the southwest Atlantic sector of the Southern Ocean contradict this view and present the first evidence that the pack-ice zone is a food-poor habitat for larval development. In contrast, the more open marginal ice zone provides a more favourable food environment for high larval krill growth rates. We found that complex under-ice habitats are, however, vital for larval krill when water column productivity is limited by light, by providing structures that offer protection from predators and to collect organic material released from the ice. The larvae feed on this sparse ice-associated food during the day. After sunset, they migrate into the water below the ice (upper 20 m) and drift away from the ice areas where they have previously fed. Model analyses indicate that this behaviour increases both food uptake in a patchy food environment and the likelihood of overwinter transport to areas where feeding conditions are more favourable in spring.

  13. Selection on a eumelanic ornament is stronger in the tropics than in temperate zones in the worldwide-distributed barn owl.

    Science.gov (United States)

    Roulin, A; Wink, M; Salamin, N

    2009-02-01

    Spatial variation in the pattern of natural selection can promote local adaptation and genetic differentiation between populations. Because heritable melanin-based ornaments can signal resistance to environmentally mediated elevation in glucocorticoids, to oxidative stress and parasites, populations may vary in the mean degree of melanic coloration if selection on these phenotypic aspects varies geographically. Within a population of Swiss barn owls (Tyto alba), the size of eumelanic spots is positively associated with survival, immunity and resistance to stress, but it is yet unknown whether Tyto species that face stressful environments evolved towards a darker eumelanic plumage. Because selection regimes vary along environmental gradients, we examined whether melanin-based traits vary clinally and are expressed to a larger extent in the tropics where parasites are more abundant than in temperate zones. To this end, we considered 39 barn owl species distributed worldwide. Barn owl species living in the tropics displayed larger eumelanic spots than those found in temperate zones. This was, however, verified in the northern hemisphere only. Parasites being particularly abundant in the tropics, they may promote the evolution of darker eumelanic ornaments.

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

    Science.gov (United States)

    Zhang, Hui; Wang, Huihui; Zhou, Xuan

    2017-04-01

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

  15. Outflow Characteristics of Total Nitrogen and Total Phosphorous of an Andisol Paddy Field in the Cool-temperate Zone during a Cropping Period

    Science.gov (United States)

    Yuto, Matsuura; Eikichi, Shima; Nagamitsu, Maie

    We investigated the water budget and outflow characteristics of total phosphorous (T-P) and total nitrogen (T-N) of an irrigated paddy field on an Andisol in the cool-temperate zone area. Total effluent flux of water from the paddy field during one cropping period was 2192 mm, 1490 mm (ca. 70%) of which flowed out through the downward percolation. The net discharge of T-P and T-N from the paddy field during one cropping period was 0.47 kg/ha and 35.9 kg/ha, respectively, most of which flowed out through downward percolation. Amounts of T-P and T-N discharged through sublayer soil to the ground water with the downward water percolation corresponded to 23% and 80% of those leached out from the plow layer soil, respectively.

  16. Relative importance of management, meteorological and environmental factors in the spatial distribution of Fasciola hepatica in dairy cattle in a temperate climate zone.

    Science.gov (United States)

    Bennema, S C; Ducheyne, E; Vercruysse, J; Claerebout, E; Hendrickx, G; Charlier, J

    2011-02-01

    Fasciola hepatica, a trematode parasite with a worldwide distribution, is the cause of important production losses in the dairy industry. Diagnosis is hampered by the fact that the infection is mostly subclinical. To increase awareness and develop regionally adapted control methods, knowledge on the spatial distribution of economically important infection levels is needed. Previous studies modelling the spatial distribution of F. hepatica are mostly based on single cross-sectional samplings and have focussed on climatic and environmental factors, often ignoring management factors. This study investigated the associations between management, climatic and environmental factors affecting the spatial distribution of infection with F. hepatica in dairy herds in a temperate climate zone (Flanders, Belgium) over three consecutive years. A bulk-tank milk antibody ELISA was used to measure F. hepatica infection levels in a random sample of 1762 dairy herds in the autumns of 2006, 2007 and 2008. The infection levels were included in a Geographic Information System together with meteorological, environmental and management parameters. Logistic regression models were used to determine associations between possible risk factors and infection levels. The prevalence and spatial distribution of F. hepatica was relatively stable, with small interannual differences in prevalence and location of clusters. The logistic regression model based on both management and climatic/environmental factors included the factors: annual rainfall, mowing of pastures, proportion of grazed grass in the diet and length of grazing season as significant predictors and described the spatial distribution of F. hepatica better than the model based on climatic/environmental factors only (annual rainfall, elevation and slope, soil type), with an Area Under the Curve of the Receiver Operating Characteristic of 0.68 compared with 0.62. The results indicate that in temperate climate zones without large climatic

  17. Winter stream temperature in the rain-on-snow zone of the Pacific Northwest: influences of hillslope runoff and transient snow cover

    Directory of Open Access Journals (Sweden)

    J. A. Leach

    2014-02-01

    Full Text Available Stream temperature dynamics during winter are less well studied than summer thermal regimes, but the winter season thermal regime can be critical for fish growth and development in coastal catchments. The winter thermal regimes of Pacific Northwest headwater streams, which provide vital winter habitat for salmonids and their food sources, may be particularly sensitive to changes in climate because they can remain ice-free throughout the year and are often located in rain-on-snow zones. This study examined winter stream temperature patterns and controls in small headwater catchments within the rain-on-snow zone at the Malcolm Knapp Research Forest, near Vancouver, British Columbia, Canada. Two hypotheses were addressed by this study: (1 winter stream temperatures are primarily controlled by advective fluxes associated with runoff processes and (2 stream temperatures should be depressed during rain-on-snow events, compared to rain-on-bare-ground events, due to the cooling effect of rain passing through the snowpack prior to infiltrating the soil or being delivered to the stream as saturation-excess overland flow. A reach-scale energy budget analysis of two winter seasons revealed that the advective energy input associated with hillslope runoff overwhelms vertical energy exchanges (net radiation, sensible and latent heat fluxes, bed heat conduction, and stream friction and hyporheic energy fluxes during rain and rain-on-snow events. Historical stream temperature data and modelled snowpack dynamics were used to explore the influence of transient snow cover on stream temperature over 13 winters. When snow was not present, daily stream temperature during winter rain events tended to increase with increasing air temperature. However, when snow was present, stream temperature was capped at about 5 °C, regardless of air temperature. The stream energy budget modelling and historical analysis support both of our hypotheses. A key implication is that

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

    Directory of Open Access Journals (Sweden)

    Marta Ziemińska-Smyk

    2013-12-01

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

  19. Field observations of climbing behavior and seed predation by adult ground beetles (Coleoptera: Carabidae) in a lowland area of the temperate zone.

    Science.gov (United States)

    Sasakawa, Kôji

    2010-10-01

    Granivory is a specialized food habit in the predominantly carnivorous beetle family Carabidae. Most studies of carabid granivory have been conducted under laboratory conditions; thus, our knowledge of the feeding ecology of granivorous carabids in the field is insufficient. I conducted field observations of climbing behavior and seed predation by adult carabids in a lowland area of eastern Japan, from early October to late November in 2008. This is the first systematic field observation of the feeding ecology of granivorous carabids in the temperate zone. In total, 176 carabid individuals of 11 species were observed, with 108 individuals feeding on plant seeds/flowers. Each carabid species was primarily observed feeding on a particular plant species. Frequently observed combinations were: Amara gigantea Motschulsky on Humulus scandens (Loureiro) Merrill (Moraceae) seed, Amara lucens Baliani on Artemisia indica Willdenow (Asteraceae) flower, and Amara macronota (Solsky) and Harpalus (Pseudoophonus) spp. on Digitaria ciliaris (Retzius) Koeler (Poaceae) seed. In all but one species, the sex ratio of individuals observed feeding was female-biased. In Am. gigantea and Am. macronota, a larger proportion of females than males ate seeds. In the three Amara species, copulations on plants, with the female feeding on its seeds/flowers, were often observed. These observations may indicate that, whereas females climb onto plants to feed on seeds, males climb to seek females for copulation rather than forage. Because granivorous carabids play important roles as weed-control agents in temperate agro-ecosystems, the present results would provide valuable basic information for future studies on this subject.

  20. Sedimentary Processes of Unstable Ice Sheet Grounding Zones: Comparing Polar and Temperate Grounding Zone Wedges Using Marine Geophysical Data and Outcrop Studies

    Science.gov (United States)

    Demet, B. P.; Anderson, J. B.; Nittrouer, J. A.; Simkins, L.; Halberstadt, A. R.; Prothro, L. O.

    2015-12-01

    Current understanding of ice sheet grounding zone dynamics is limited because direct observation of grounding zones and their deposits (grounding zone wedges, GZW) is restricted to marine geophysical methods, which provide large-scale measurements of planform morphology and internal stratigraphy, but little information regarding sedimentary architecture. Seismic data nevertheless reveal that GZW range meters to kilometers in length scale and typically possess foresets and incised channels. Sediment cores from measured wedges are helpful for evaluating vertical changes in stratigraphy, but leave significant uncertainty regarding the spatial variability of deposits and the nature of their contacts, which are necessary data to evaluate sedimentary processes operating within grounding zones. This study presents results from outcrop studies of GZW exposed in sea cliffs of the Puget Sound, Washington (U.S.A.), where a series of back-stepping GZW record rapid grounding line retreat of the Puget Lobe. These outcrops are used to evaluate first-order physical controls on depositional processes. The data are compared to geophysical observations and cores collected from the Ross Sea, Antarctic, to evaluate similarities between the outcrop-scale deposits and polar grounding zone wedges that possess wavelengths measuring several kilometers, and amplitudes of tens of meters. The preliminary results show that for these larger features, wedge progradation is facilitated by foreset deposition. Alternatively, for small-scale wedges (100's of m wavelength, m-scale amplitudes), wedge development occurs through topset aggradation. Additionally, based on the Puget Sound GZW deposits, progradation arises due to sediment gravity flows on the foreset. Sand and silt couplets, preserved within wedge foresets, suggest that tidal pumping occurred under ice, producing deposits between punctuated sediment gravity flows. These data show a multitude of sedimentary and morphological scales that are

  1. Verlorenvlei - The first continuous Holocene high-resolution lake sediment record from the Winter Rainfall Zone of South Africa

    Science.gov (United States)

    Haberzettl, T.; Kasper, T.; Lederer, M.; Wündsch, M.; Frenzel, P.; Zabel, M.; Kirsten, K. L.; Meadows, M. E.; Quick, L. J.; St-Onge, G.; Maeusbacher, R.

    2015-12-01

    Verlorenvlei is a coastal lake in the Winter Rainfall Zone of the Western Cape Province of South Africa. Up to now several attempts have been made to recover sediment cores from this lake. However, no continuous high-resolution record covering large parts of the Holocene has been available so far. Within the project RAIN (Regional Archives for Integrated iNvestigations) it was possible to recover a 14.2 m paired parallel core from the central part of Verlorenvlei. Investigations on recent surface sediment distributions (elemental composition and grain sizes) indicate that this sediment core is very well suited for paleoenvironmental reconstructions. Using a set of 23 radiocarbon ages, a chronology for the past 9,000 cal BP was established which suggests continuous sedimentation over this period. Preliminary lithological and geochemical investigations show that this record can be used for sea level reconstructions as the lake was periodically inundated by the ocean during the past 9,000 cal BP. This is recorded in distinctly elevated Ca and Sr contents as well as the occurrence of marine indicator species (snail and mussel shells) in parts of the sediment core. Thin, pale grey layers of fine sediment occurring at various sediment depths seem to reflect event related deposits. In terms of lithology, geochemical and magnetic composition, the upper 50 cm clearly differ from the rest of the record and indicate increased sediment supply from the catchment, which is likely linked to anthropogenic farming activities. In conclusion, the newly recovered sediment record from Verlorenvlei offers excellent potential for a detailed, high-resolution reconstruction of sea level changes, climate variations and anthropogenic impact during the past 9,000 cal BP in an area in which natural archives are very scarce or poorly dated.

  2. Seasonal succession of phytoplankton community and its relationship with environmental factors of North Temperate Zone water of the Zhalong Wetland, in China.

    Science.gov (United States)

    Ma, Yun; Li, Guibai; Li, Jing; Zhou, Hao; Jiang, Bing

    2014-05-01

    A data set of phytoplankton community and environmental parameters in a hydrological integrity period, i.e. a poor water term, a medium term and a rich water term of North Temperate Zone climate, was analyzed in order to describe seasonal variation of phytoplankton community and its relationship with environmental variables in the Zhalong Wetland of China. The algal population of the Zhalong Wetland was not abundant, with a mean density of 5.08 × 10(7) cell/L (ranged from 4.54 × 10(7) cell/L in a poor term to 5.56 × 10(7) cell/L a medium term). However, its diversity was essentially limited to Cryptophyta, Bacillariophyta, Chlorophyta, Euglenophyta being the group with highest densities. There were considerable seasonal variations in phytoplankton composition. In general, the dominance of Bacillariophyceae was found in a medium term, which was higher than the other period (p NO2-N), suspend solid, nitrate (NO3-N), silicon dioxide (SiO2) and all the 10 physical-chemical parameters had a higher marginal effect and λA in the series of constrained CCAs though they were not significant.

  3. Variation in cold hardiness of nondiapausing eggs of nine Aedes (Stegomyia) species (Diptera: Culicidae) from eastern Asia and Pacific islands ranging from the tropics to the cool-temperate zone.

    Science.gov (United States)

    Mogi, Motoyoshi

    2011-03-01

    Variation in cold hardiness was studied in the laboratory for the nondiapausing eggs of nine Aedes (Stegomyia) species from eastern Asia and Pacific islands, ranging from the tropics to the cool-temperate zone. Species included were Aedes aegypti (L.), Aedes albopictus (Skuse), Aedes flavopictus Yamada, Aedes galloisi Yamada, Aedes hensilli Farner, Aedes palauensis Bohart, Aedes paullusi Stone and Farner, Aedes riversi Bohart and Ingram, and Aedes scutellaris (Walker). For species with distributions covering two or three climatic zones, at least one population was included from each zone, except for Ae. aegypti (subtropical populations were unavailable). Some eggs of four species confined to the tropical zone survived short exposure to freezing temperature (> or = -5 degrees C) when humidity was high. There were inter- and intraspecies variations in cold hardiness of nondiapausing eggs. Cold hardiness in each climatic zone differed in that populations of species with more northerly distributions were more cold-hardy than species with southerly distributions. In Ae. albopictus and Ae. flavopictus that cover three climatic zones, populations from cooler regions were more cold-hardy than populations from warmer regions. A possibility of southern species without diapausing eggs to colonize temperate eastern Asia was discussed.

  4. Contrasting patterns of groundwater evapotranspiration in grass and tree dominated riparian zones of a temperate agricultural catchment

    Science.gov (United States)

    Satchithanantham, Sanjayan; Wilson, Henry F.; Glenn, Aaron J.

    2017-06-01

    Consumptive use of shallow groundwater by phreatophytic vegetation is a significant part of the water budget in many regions, particularly in riparian areas. The influence of vegetation type on groundwater level fluctuations and evapotranspiration has rarely been quantified for contrasting plant communities concurrently although it has implications for downstream water yield and quality. Hourly groundwater evapotranspiration (ETG) rates were estimated for grass and tree riparian vegetation in southwestern Manitoba, Canada using two modified White methods. Groundwater table depth was monitored in four 21 m transects of five 3 m deep monitoring wells in the riparian zone of a stream reach including tree (Acer negundo; boxelder) and grass (Bromus inermis; smooth brome) dominated segments. The average depths to the groundwater table from the surface were 1.4 m and 1 m for the tree and grass segments, respectively, over the two-year study. During rain free periods of the growing season ETG was estimated for a total of 70 days in 2014 and 79 days in 2015 when diurnal fluctuations were present in groundwater level. Diurnal groundwater level fluctuations were observed during dry periods under both segments, however, ETG was significantly higher (p < 0.001) under trees compared to grass cover in 2014 (a wet year with 72% higher than normal growing season precipitation) and 2015 (a drier year with 15% higher than normal growing season precipitation). The two methods used to estimate ETG produced similar daily and seasonal values for the two segments. In 2014, total ETG was approximately 50% (148 mm) and 100% (282-285 mm) of reference evapotranspiration (ETref, 281 mm) for the grass and tree segments, respectively. In 2015, total ETG was approximately 40% (106-127 mm) and 120% (369-374 mm) of ETref (307 mm) for the grass and tree segments, respectively. Results from the study show the tree dominated portions of the stream reach consumed approximately 2.4 ML ha-1 yr-1 more

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

    Directory of Open Access Journals (Sweden)

    Xiao Chen

    2016-09-01

    Full Text Available With the urbanization process of the hot summer and cold winter (HSCW zone in China, the energy consumption of space and water heating in urban residential buildings of the HSCW zone has increased rapidly. This study presents the energy efficiency and sustainability evaluation of various ways of space and water heating taking 10 typical cities in the HSCW zone as research cases. Two indicators, primary energy efficiency (PEE and sustainability index based on exergy efficiency, are adopted to perform the evaluation. Models for the energy and total exergy efficiencies of various space and water heating equipment/systems are developed. The evaluation results indicate that common uses of electricity for space and water heating are the most unsustainable ways of space and water heating. In terms of PEE and sustainability index, air-source heat pumps for space and water heating are suitable for the HSCW zone. The PEE and sustainability index of solar water heaters with auxiliary electric heaters are greatly influenced by local solar resources. Air-source heat pump assisted solar hot water systems are the most sustainable among all water heating equipment/systems investigated in this study. Our works suggest the key potential for improving the energy efficiency and the sustainability of space and water heating in urban residential buildings of the HSCW zone.

  6. Primary production and microbial activity in the euphotic zone of Lake Baikal (Southern Basin) during late winter

    Science.gov (United States)

    Straškrábová, V.; Izmest'yeva, L. R.; Maksimova, E. A.; Fietz, S.; Nedoma, J.; Borovec, J.; Kobanova, G. I.; Shchetinina, E. V.; Pislegina, E. V.

    2005-04-01

    Three years of regular weekly/biweekly monitoring of seasonal changes in temperature, transparency, chlorophyll a (CHL) and bacteria [erythrosine-stained microscopic counts and cultivable colony forming units (CFUs)] at the vertical profile in the South basin of Lake Baikal (51°54'195″N, 105°04'235″E, depth 800 m) were evaluated. In more detail, the structure and function of phytoplankton and the microbial loop in the euphotic layer at the same site were investigated during the late-winter-early-spring period under the ice. The depth of euphotic zone (up to 1% of surface irradiation) was 35 to 40 m. Primary production was measured three times a week with the 14C method in 2, 10, 20, 30 and 40 m. Maximum production was found in 10 m, with lower values towards the surface (light inhibition) and towards the lower layers. The total production in cells larger than 1 μm in the column (0-40 m) was 204-240 mg C d -1 m -2, 30-40% of it being in cells 1-3 μm (mostly picocyanobacteria), which represented roughly 9% of the total chlorophyll a (estimated from pigment analyses). A major part of phytoplankton biomass was formed by diatoms ( Synedra acus Hust., Asterionella formosa Hass. and Stephanodiscus meyerii Genkal & Popovskaya). Total production (including extracellular, dissolved organic matter) was 235-387 mg C day -1 m -2, and the exudates were readily used by bacteria (particles 0.2-1 μm). This part amounted to 1-5% of cellular production in 2 to 20 m and 11-77% of cellular production in 20-40 m, i.e., in light-limited layers. From 0 to 30 m, chlorophyll a concentration was 0.8 to 1.3 μg l -1, wherefrom it decreased rapidly to 0.1 μg l -1 towards the depth of 40 m. Bacteria (DAPI-stained microscopic counts) reached 0.5-1.4×10 6 ml -1; their cell volumes measured via image analysis were small (average 0.05 μm -3), often not well countable when erythrosine stain was used. Bacterial biomasses were in the range of 6-21 μg C l -1. Numbers of colony forming

  7. Effects of Climate Change on Stratification-Destratification Cycles and Resulting Cyanobacterial Blooms in Shallow Lakes of the North Temperate Zone

    Science.gov (United States)

    King, A. T.; Schaffner, L. R.; Gilman, B.; Gronwall, T. R.; Gronwall, D.; Dietz, E. R.; Hairston, N., Jr.

    2016-12-01

    function of lake morphometry, summer temperature, and summer storm frequency and intensity. This allows projection of the effects of different climate change scenarios on the incidence of cyanoHABs for this lake and for lakes along a continuum of length-depth morphometries across the North Temperate Zone.

  8. Salmonid behaviour under winter conditions

    OpenAIRE

    Watz, Johan

    2015-01-01

    Winter conditions are believed to play an important role in the population dynamics of northern temperate stream fish, challenging the ability of fish to physiologically and behaviourally adapt. Climate change is predicted to increase both mean temperature and temperature fluctuations, especially during winter, leading to dynamic environmental conditions in terms of river ice production and flow. Therefore, knowledge about the winter ecology of stream fish is important for predicting and miti...

  9. Prey type and foraging ecology of sanderlings Calidris alba in different climate zones : Are tropical areas more favourable than temperate sites?

    NARCIS (Netherlands)

    Grond, Kirsten; Ntiamoa-Baidu, Yaa; Piersma, Theunis; Reneerkens, Jeroen

    2015-01-01

    Sanderlings (Calidris alba) are long-distance migratory shorebirds with a non-breeding range that spans temperate and tropical coastal habitats. Breeding in the High Arctic combined with non-breeding seasons in the tropics necessitate long migrations, which are energetically demanding. On an annual

  10. Temper Foam

    Science.gov (United States)

    1981-01-01

    Fabricated by Expanded Rubber & Plastics Corporation, Temper Foam provides better impact protection for airplane passengers and enhances passenger comfort on long flights because it distributes body weight and pressure evenly over the entire contact area. Called a "memory foam" it matches the contour of the body pressing against it and returns to its original shape once the pressure is removed. As a shock absorber, a three-inch foam pad has the ability to absorb the impact of a 10-foot fall by an adult. Applications include seat cushioning for transportation vehicles, padding for furniture and a variety of athletic equipment medical applications including wheelchair padding, artificial limb socket lining, finger splint and hand padding for burn patients, special mattresses for the bedridden and dental stools. Production and sales rights are owned by Temper Foam, Inc. Material is manufactured under license by the Dewey and Almy Division of Grace Chemical Corporation. Distributors of the product are Kees Goebel Medical Specialties, Inc. and Alimed, Inc. They sell Temper Foam in bulk to the fabricators who trim it to shapes required by their customers.

  11. Myctophid and pelagic shrimp assemblages in the oxygen minimum zone of the Andaman Sea during the winter monsoon

    Digital Repository Service at National Institute of Oceanography (India)

    Karuppasamy, P.K.; LaluRaj, C.M.; Muraleedharan, K.R.; Nair, M.

    . These micronektonic animals show strong vertical and horizontal migrations and play a significant role in the transport and redistribution of organic matter from epipelagic to mesopelagic zones2. During the daytime they migrate to deeper suboxic waters where... like tuna, sharks, and barracudas. The abundance and distribution of the barracudas in the oceanic waters provide clues to the quantitative and qualitative nature of micronekton4. Larger animals migrate to deeper waters (300-400 m) than the smaller...

  12. The dynamic relationship between temperate and tropical circulation systems across South Africa since the last glacial maximum

    Science.gov (United States)

    Chase, Brian M.; Chevalier, Manuel; Boom, Arnoud; Carr, Andrew S.

    2017-10-01

    A fundamental and long-standing question of southern African palaeoclimatology is the way tropical and temperate climate system dynamics have influenced rainfall regimes across the subcontinent since the Last glacial maximum. In this paper, we analyse a selection of recently published palaeoclimate reconstructions along a southwest-northeast transect across South Africa. These records span the last 22,000 years, and encompass the transition between the region's winter and summer rainfall zones. In synthesis, these records confirm broad elements of the dominant paradigm, which proposes an inverse coeval relationship between temperate and tropical systems, with increased precipitation in the winter (summer) rainfall zone during glacial (interglacial) periods. Revealed, however, is a substantially more complex dynamic, with millennial-scale climate change events being strongly - even predominantly - influenced by the interaction and combination of temperate and tropical systems. This synoptic forcing can create same sign anomalies across the South African rainfall zones, contrary to expectations based on the classic model of phase opposition. These findings suggest a new paradigm for the interpretation of southern African palaeoenvironmental records that moves beyond simple binary or additive influences of these systems.

  13. TEMPERED FRACTIONAL CALCULUS

    Science.gov (United States)

    MEERSCHAERT, MARK M.; SABZIKAR, FARZAD; CHEN, JINGHUA

    2014-01-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series. PMID:26085690

  14. Tempered fractional calculus

    Energy Technology Data Exchange (ETDEWEB)

    Sabzikar, Farzad, E-mail: sabzika2@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Meerschaert, Mark M., E-mail: mcubed@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Chen, Jinghua, E-mail: cjhdzdz@163.com [School of Sciences, Jimei University, Xiamen, Fujian, 361021 (China)

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  15. TEMPERED FRACTIONAL CALCULUS.

    Science.gov (United States)

    Meerschaert, Mark M; Sabzikar, Farzad; Chen, Jinghua

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  16. Prey type and foraging ecology of Sanderlings Calidris alba in different climate zones: are tropical areas more favourable than temperate sites?

    Science.gov (United States)

    Ntiamoa-Baidu, Yaa; Piersma, Theunis; Reneerkens, Jeroen

    2015-01-01

    Sanderlings (Calidris alba) are long-distance migratory shorebirds with a non-breeding range that spans temperate and tropical coastal habitats. Breeding in the High Arctic combined with non-breeding seasons in the tropics necessitate long migrations, which are energetically demanding. On an annual basis, the higher energy expenditures during migration might pay off if food availability in the tropics is higher than at temperate latitudes. We compared foraging behaviour of birds at a north temperate and a tropical non-breeding site in the Netherlands and Ghana, respectively. In both cases the birds used similar habitats (open beaches), and experienced similar periods of daylight, which enabled us to compare food abundance and availability, and behavioural time budgets and food intake. During the non-breeding season, Sanderlings in the Netherlands spent 79% of their day foraging; in Ghana birds spent only 38% of the daytime period foraging and the largest proportion of their time resting (58%). The main prey item in the Netherlands was the soft-bodied polychaete Scolelepis squamata, while Sanderlings in Ghana fed almost exclusively on the bivalve Donax pulchellus, which they swallowed whole and crushed internally. Average availability of polychaete worms in the Netherlands was 7.4 g ash free dry mass (AFDM) m−2, which was one tenth of the 77.1 g AFDM m−2 estimated for the beach in Ghana. In the tropical environment of Ghana the Sanderlings combined relatively low energy requirements with high prey intake rates (1.64 mg opposed to 0.13 mg AFDM s−1 for Ghana and the Netherlands respectively). Although this may suggest that the Ghana beaches are the most favourable environment, processing the hard-shelled bivalve (D. pulchellus) which is the staple food could be costly. The large amount of daytime spent resting in Ghana may be indicative of the time needed to process the shell fragments, rather than indicate rest. PMID:26290790

  17. Prey type and foraging ecology of Sanderlings Calidris alba in different climate zones: are tropical areas more favourable than temperate sites?

    Directory of Open Access Journals (Sweden)

    Kirsten Grond

    2015-08-01

    Full Text Available Sanderlings (Calidris alba are long-distance migratory shorebirds with a non-breeding range that spans temperate and tropical coastal habitats. Breeding in the High Arctic combined with non-breeding seasons in the tropics necessitate long migrations, which are energetically demanding. On an annual basis, the higher energy expenditures during migration might pay off if food availability in the tropics is higher than at temperate latitudes. We compared foraging behaviour of birds at a north temperate and a tropical non-breeding site in the Netherlands and Ghana, respectively. In both cases the birds used similar habitats (open beaches, and experienced similar periods of daylight, which enabled us to compare food abundance and availability, and behavioural time budgets and food intake. During the non-breeding season, Sanderlings in the Netherlands spent 79% of their day foraging; in Ghana birds spent only 38% of the daytime period foraging and the largest proportion of their time resting (58%. The main prey item in the Netherlands was the soft-bodied polychaete Scolelepis squamata, while Sanderlings in Ghana fed almost exclusively on the bivalve Donax pulchellus, which they swallowed whole and crushed internally. Average availability of polychaete worms in the Netherlands was 7.4 g ash free dry mass (AFDM m−2, which was one tenth of the 77.1 g AFDM m−2 estimated for the beach in Ghana. In the tropical environment of Ghana the Sanderlings combined relatively low energy requirements with high prey intake rates (1.64 mg opposed to 0.13 mg AFDM s−1 for Ghana and the Netherlands respectively. Although this may suggest that the Ghana beaches are the most favourable environment, processing the hard-shelled bivalve (D. pulchellus which is the staple food could be costly. The large amount of daytime spent resting in Ghana may be indicative of the time needed to process the shell fragments, rather than indicate rest.

  18. Winter Use Plans Final Environmental Impact Statement Summary for the Yellowstone and Grand Teton National Parks and John D. Rockefeller, Jr., Memorial Parkway

    OpenAIRE

    United States, Department of the Interior, National Forest Service

    2000-01-01

    This document presents and analyzes seven alternatives for winter use management in Yellowstone National Park (YNP), Grand Teton National Park (GTNP), and the John D. Rockefeller, Jr., Memorial Parkway (the Parkway). YNP, encompassing 2.22 million acres, and GTNP, comprising 310,000 acres, form the core of the Greater Yellowstone Ecosystem, described as the last large, nearly intact ecosystem in the northern temperate zone. The approved plan will serve as a management plan for the three na...

  19. TEMPERED FRACTIONAL CALCULUS

    OpenAIRE

    MEERSCHAERT, MARK M.; SABZIKAR, FARZAD; CHEN, JINGHUA

    2015-01-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly obs...

  20. Temporal dynamics of soil organic carbon after land-use change in the temperate zone – carbon response functions as a model approach

    DEFF Research Database (Denmark)

    Poeplau, Christopher; Don, Axel; Vesterdal, Lars

    2011-01-01

    Land-use change (LUC) is a major driving factor for the balance of soil organic carbon (SOC) stocks and the global carbon cycle. The temporal dynamic of SOC after LUC is especially important in temperate systems with a long reaction time. On the basis of 95 compiled studies covering 322 sites...... of 0.38±0.04 Mg ha-1 yr-1 in afforestations adding up to 38±4 Mg ha-1 labile carbon after 100 years. Carbon loss after deforestation (-32±20%) and grassland conversion to cropland (-36±5%), was rapid with a new SOC equilibrium being reached after 23 and 17 years, respectively. The change rate of SOC...

  1. Temperature characteristics of winter roost-sites for birds and mammals: tree cavities and anthropogenic alternatives

    Science.gov (United States)

    Grüebler, Martin U.; Widmer, Silv; Korner-Nievergelt, Fränzi; Naef-Daenzer, Beat

    2014-07-01

    The microclimate of potential roost-sites is likely to be a crucial determinant in the optimal roost-site selection of endotherms, in particular during the winter season of temperate zones. Available roost-sites for birds and mammals in European high trunk orchards are mainly tree cavities, wood stacks and artificial nest boxes. However, little is known about the microclimatic patterns inside cavities and thermal advantages of using these winter roost-sites. Here, we simultaneously investigate the thermal patterns of winter roost-sites in relation to winter ambient temperature and their insulation capacity. While tree cavities and wood stacks strongly buffered the daily cycle of temperature changes, nest boxes showed low buffering capacity. The buffering effect of tree cavities was stronger at extreme ambient temperatures compared to temperatures around zero. Heat sources inside roosts amplified Δ T (i.e., the difference between inside and outside temperatures), particularly in the closed roosts of nest boxes and tree cavities, and less in the open wood stacks with stronger circulation of air. Positive Δ T due to the installation of a heat source increased in cold ambient temperatures. These results suggest that orchard habitats in winter show a spatiotemporal mosaic of sites providing different thermal benefits varying over time and in relation to ambient temperatures. At cold temperatures tree cavities provide significantly higher thermal benefits than nest boxes or wood stacks. Thus, in winter ecology of hole-using endotherms, the availability of tree cavities may be an important characteristic of winter habitat quality.

  2. Potential effects of climate change on the temperate zones of North and South America Potenciales efectos del cambio climático en zonas templadas de América del Norte y del Sur

    Directory of Open Access Journals (Sweden)

    W.K. LAUENROTH

    2004-09-01

    Full Text Available Under current conditions, large areas of temperate western North America and temperate southern South America have arid to subhumid climates that make them vulnerable to changes as a result of human-induced climate change. Predictions of climate change from global circulation models with a doubling of present atmospheric levels of CO2 suggest large changes in mean annual temperature and small to no changes in mean annual precipitation and the proportion of precipitation received during the summer. Our objective here was to evaluate how predictions of climate change from global circulation models will influence climatic patterns and by inference the distribution of temperate zone ecosystems in North and South America. Calculations of annual water deficits suggest that the area affected by very dry conditions will double as a result of climate change. This expansion will take place in the vicinity of the currently dry areas. Monthly water deficit calculations suggest that approximately half of the temperate zone on each continent is affected by at least one month of deficit. Under a doubled CO2 climate, these areas would expand to cover up to 77 % of the temperate zone of North America and up to 80 % of South America. The resulting changes to the current distribution of ecosystems will likely be an expansion of deserts at the expense of grasslands in North and South America and an expansion of grasslands at the expense of deciduous and boreal forest in North America. Our analyses assumed that future climatic changes will be encompassed by the predictions of our three doubled CO2 scenarios. The most likely situation is that actual changes, if they occur, will be different from our scenarios. Therefore, our analyses should be interpreted as indications of the sensitivity of portions of the North and South American temperate zones to increases in temperature. The key conclusion from our analyses is that any increase in temperature caused by climate

  3. The potential of coastal lakes in the Winter-Rainfall-Zone of South Africa for paleoenvironmental reconstructions - an example from Verlorenvlei

    Science.gov (United States)

    Kasper, Thomas; Haberzettl, Torsten; Lederer, Martin; Wündsch, Michael; Frenzel, Peter; Zabel, Matthias; Kirsten, Kelly; Carr, Andrew; Daut, Gerhard; Cawthra, Hayley; Baade, Jussi; Meadows, Michael; Quick, Lynne; Mäusbcher, Roland

    2016-04-01

    Verlorenvlei is a coastal lake in the winter rainfall zone of the Western Cape Province of South Africa. Up to now, several attempts have been made to recover sediment cores from this lake. However, no continuous high-resolution record covering the entire Holocene has been acquired. Within the project RAiN (Regional Archives for Integrated iNvestigations) a 14.2 m paired parallel core from the central part of Verlorenvlei was recovered. Based on analyses of surface sediment samples, recent elemental and grain size distributions indicate that this sediment core is well suited for paleoenvironmental reconstructions. Using a set of 23 radiocarbon ages, a chronology was established for the past 9,400 cal BP suggesting continuous sediment deposition throughout the entire period. Preliminary lithological and geochemical investigations show that this record can be used for sea level reconstructions as the lake was periodically inundated by the ocean during the past 9,400 cal BP. This is recorded in distinctly elevated Ca and Sr contents as well as the occurrence of marine indicator species (gastropods) in parts of the sediment core. Thin, pale grey layers of fine sediment occurring at various sediment depths seem to reflect event-related deposits, but do not showing erosional structures. In terms of lithology, geochemical and magnetic composition, the upper 50 cm (ca. 100 cal BP) clearly differ from the rest of the record indicating increased sediment supply from the catchment, which is likely linked to anthropogenic activities. The presented sediment record from Verlorenvlei offers excellent potential for a detailed, high-resolution reconstruction of sea level changes, climate variations and anthropogenic impact during the past 9,400 cal BP in an area in which natural archives are very scarce or poorly dated.

  4. Evidence for an Early Origin of Vernalization Responsiveness in Temperate Pooideae Grasses.

    Science.gov (United States)

    McKeown, Meghan; Schubert, Marian; Marcussen, Thomas; Fjellheim, Siri; Preston, Jill C

    2016-09-01

    The ability of plants to match their reproductive output with favorable environmental conditions has major consequences both for lifetime fitness and geographic patterns of diversity. In temperate ecosystems, some plant species have evolved the ability to use winter nonfreezing cold (vernalization) as a cue to ready them for spring flowering. However, it is unknown how important the evolution of vernalization responsiveness has been for the colonization and subsequent diversification of taxa within the northern and southern temperate zones. Grasses of subfamily Pooideae, including several important crops, such as wheat (Triticum aestivum), barley (Hordeum vulgare), and oats (Avena sativa), predominate in the northern temperate zone, and it is hypothesized that their radiation was facilitated by the early evolution of vernalization responsiveness. Predictions of this early origin hypothesis are that a response to vernalization is widespread within the subfamily and that the genetic basis of this trait is conserved. To test these predictions, we determined and reconstructed vernalization responsiveness across Pooideae and compared expression of wheat vernalization gene orthologs VERNALIZATION1 (VRN1) and VRN3 in phylogenetically representative taxa under cold and control conditions. Our results demonstrate that vernalization responsive Pooideae species are widespread, suggesting that this trait evolved early in the lineage and that at least part of the vernalization gene network is conserved throughout the subfamily. These results are consistent with the hypothesis that the evolution of vernalization responsiveness was important for the initial transition of Pooideae out of the tropics and into the temperate zone. © 2016 American Society of Plant Biologists. All rights reserved.

  5. Spatial and temporal changes in invertebrate assemblage structure from the entrance to deep-cave zone of a temperate marble cave

    Directory of Open Access Journals (Sweden)

    Benjamin W. Tobin

    2013-09-01

    Full Text Available Seasonality in surface weather results in seasonal temperature and humidity changes in caves. Ecological and physiological differences among trogloxenes, troglophiles, and troglobionts result in species-dependent responses to this variability. To investigate these responses, we conducted five biological inventories in a marble cave in the Sierra Nevada Range, California, USA between May and December 2010. The cave was divided into six quadrats and temperature was continuously logged in each (humidity was logged at the entrance and in the deep cave. With increasing distance from the entrance, temperature changes were increasingly attenuated and lagged relative to surface temperature. Linear regressions were created to determine the relationship between measured environmental variables and diversity for cavernicoles (troglobionts and troglophiles and trogloxenes cave– wide and in the transition zone. Diversity for cavernicoles and trogloxenes peaked in the entrance and deep cave zones, respectively. Quadrat, date, 2-week antecedent temperature average, 2-week antecedent temperature range, and trogloxene abundance explained 76% of cavernicole diversity variability. Quadrat explained 55% of trogloxene diversity variability. In the transition zone, trogloxene abundance explained 26% of cavernicole variability and 2-week antecedent temperature and 2-week antecedent temperature range explained 40% of trogloxene variability. In the transition zone, trogloxene diversity was inversely related to 2-week antecedent temperature average and 2-week antecedent temperature range, suggesting that species were moving into the transition zone when temperature was most stable. In a CCA of cavernicoles distribution data and environmental variables, 35% of variation in species-specific distributions was attributable to quadrat, and non-significant percentages were explained by date and environmental variables. Differences in assemblage structure among quadrats were

  6. Winter MVC

    OpenAIRE

    Castellón Gadea, Pasqual

    2013-01-01

    Winter MVC és un framework de presentació basat en Spring MVC que simplifica la metodologia de configuracions. Winter MVC es un framework de presentación basado en Spring MVC que simplifica la metodología de configuraciones. Winter MVC is a presentation framework that simplifies Spring MVC configuration methodology.

  7. Serial tempering without exchange.

    Science.gov (United States)

    Nymeyer, Hugh

    2010-09-21

    Serial tempering is a computational method that turns the temperature T (or more generally any independent λ parameter) into a dynamical variable. It is shown that, under conditions for which this variable is fast, serial tempering is equivalent to the umbrella sampling method with a single effective potential. This equivalence is demonstrated using both a small one-dimensional system and a small solvated peptide. The suggestion is then made to replace the serial tempering protocol with the equivalent umbrella sampling calculation. This approach, serial tempering without exchange (STeWiE), has the same performance as serial tempering in the limit that exchanges are frequent, is simpler to implement, and has fewer adjustable parameters than conventional serial tempering. The equivalence of serial tempering and STeWiE also provides a convenient route for estimating and optimizing the performance of serial tempering simulations and other generalized-ensemble methods.

  8. Take-off time of the first generation of the overwintering small brown planthopper, Laodelphax striatellus in the temperate zone in East Asia.

    Directory of Open Access Journals (Sweden)

    Sachiyo Sanada-Morimura

    Full Text Available Overseas migration of the small brown planthopper, Laodelphax striatellus (Fallén, occurs during the winter wheat harvest season in East Asia. Knowing the take-off time of emigrating L. striatellus is crucial for predicting such migrations with a simulation technique because winds, carriers of migratory insects, change continuously. Several methods were used in China and Japan from late May to early June 2012 and again in 2013 to identify the precise timing of take-off. These methods included: a tow net trap mounted to a pole at 10 m above the ground, a helicopter-towed net trap, and a canopy trap (which also had video monitoring set over wheat plants. Laodelphax striatellus emigrated from wheat fields mainly in the early evening, before dusk. The insects also emigrated during the daytime but rarely emigrated at dawn, showing a pattern that is unlike the bimodal emigration at dusk and dawn of two other rice planthoppers, the brown planthopper, Nilaparvata lugens (Stål, and the white-backed planthopper, Sogatella furcifera (Horváth. There was no significant difference in the temporal pattern of take-off behavior between females and males of Japanese L. striatellus populations.

  9. Determinação por cromatografia gasosa de açúcares em frutíferas de clima temperado Gas chromatography determination of sugars in temperate-zone fruit trees

    Directory of Open Access Journals (Sweden)

    Alexandre Couto Rodrigues

    2005-04-01

    Full Text Available As frutíferas de clima temperado apresentam o fenômeno da dormência. Na saída da dormência, há a conversão do amido para açúcares solúveis, como substrato para a retomada de crescimento na primavera. Visando à maior compreensão da fisiologia das plantas em respostas a eventos, como as variações climáticas, estresses e problemas de adaptação, desenvolveu-se este trabalho, no Laboratório de Fisiologia Vegetal da Embrapa Clima Temperado, com o objetivo de descrever uma metodologia para a determinação das concentrações dos açúcares solúveis (frutose, sorbitol, alfa-glicose, beta-glicose e sacarose, em tecidos vegetais de frutíferas, via cromatografia gasosa. O cromatógrafo utilizado para as análises dos açúcares por essa metodologia é o GAS CHROMATOGRAPH e a coluna do tipo Packed Column J. K. de 3,2mm de diâmetro por 2m de comprimento, empacotada com Silicone SE-52 Uniport HP 80/100 mesh. Através da cromatografia gasosa, obtêm-se eficiência e resolução cromatográfica, para análises de açúcares solúveis, sendo, desta forma, vantajoso e executável esse tipo de análise pelo método descrito.The temperate-zone deciduous fruit trees present the phenomenon of dormancy. In that period, there is the conversion of the starch in soluble sugars, as substratum for the resumption of growth in the spring. Seeking to better understanding the physiology of the plants in answers to events as the climatic variations, stresses and adaptation problems, this study was done in the Laboratory of Crop Physiology of Embrapa Temperate Climate, with the objective of describing a methodology for determination of concentrations of the soluble sugars (fructose, sorbitol, alpha-glucose, beta-glucose and sucrose, in tissues of fruit tree, through gaseous chromatography. The chromatograph used for the analyses of the sugars was the GAS CHROMATOGRAPH with the column of the type Packed Column J. K. of 3,2mm of diameter for 2m of length

  10. Does outdoor work during the winter season protect against depression and mood difficulties?

    DEFF Research Database (Denmark)

    Hahn, Ina H; Grynderup, Matias; Dalsgaard, Sofie B

    2011-01-01

    At temperate latitudes, 1-5% of the population suffer from winter depression; during winter, mood difficulties tend to increase but may be alleviated by bright light therapy. Unlike indoor workers, outdoor workers are exposed to therapeutic levels of sunlight during winter. We hypothesized that o...... that outdoor work may protect against mood difficulties and depression.......At temperate latitudes, 1-5% of the population suffer from winter depression; during winter, mood difficulties tend to increase but may be alleviated by bright light therapy. Unlike indoor workers, outdoor workers are exposed to therapeutic levels of sunlight during winter. We hypothesized...

  11. The Need for Temperance

    Directory of Open Access Journals (Sweden)

    Karl Inge Tangen

    2015-11-01

    Full Text Available This article explores how temperance as a virtue relates to organizational leadership. The study begins with a short survey of classical Greek and Christian notions of temperance before proceeding to ex-plore temperance in relation to self-leadership, visionary and strategic leadership, and relational lead-ership. The final part of the article offers reflections on how temperance might be cultivated from a theological perspective. Temperance is understood not only as sound thinking but also as embodied self-control and active patience. On the level of self-leadership, it is argued that temperance enables the leader to establish forms of integrity that protect the leader’s self from chaos and destruction. Moreover, temperance may also nurture focused visionary leadership that accepts ethical limits and has an eye to the common good. The study also suggests that organizations should cultivate a culture of strategic discipline that is capable of realizing such visions. On the interpersonal level, temperance is viewed as critical in terms of enabling leaders to treat co-workers with respect and wisdom and han-dle conflict with consideration. Finally, is argued that that the cultivation of temperance is not a one-way street from the inside to the outside or a subordination of feelings to reason but rather a very complex process that includes interpersonal humility, finds vision in an encounter with the good, and yet remains a personal responsibility.

  12. Patrones geográficos de distribuci��n de árboles y arbustos en la zona de transición climática mediterráneo-templada de Chile Geographic patterns of distribution of trees and shrubs in the transitional Mediterranean-temperate climatic zone of Chile

    Directory of Open Access Journals (Sweden)

    ERNESTO A. TENEB

    2004-03-01

    Full Text Available Uno de los principales objetivos de la biogeografía es determinar si las especies se distribuyen en el espacio en forma aleatoria o si existen grupos de especies con patrones de distribución comunes. En el presente estudio determinamos a través de técnicas cuantitativas si existen corotipos, es decir, grupos de especies con patrones de distribución común entre los árboles y arbustos en la zona de transición climática mediterráneo-templada de Chile, Octava Región de Chile. Adicionalmente, evaluamos la relación entre el clima y la distribución de los diferentes grupos de árboles y arbustos de la Octava Región. El análisis de agrupamiento de especies permitió definir 24 corotipos significativos, de los cuales 18 responden significativamente con alguna variable ambiental analizada. La temperatura media anual, la temperatura media invernal y la temperatura media de verano resultaron ser las variables que mejor explican el patrón de distribución de la mayoría de los corotipos. Las tendencias geográficas de los corotipos y su relación con las variables ambientales fueron evaluadas mediante un análisis de ordenación. Los resultados señalan que los corotipos con distribución en la cordillera de los Andes se correlacionan con la temperatura de invierno en tanto que los corotipos con distribución costera se correlacionan con la mediterraneidad. Se discute respecto de la utilización de una nueva aproximación para el análisis fitogeográfico y de su utilidad en el estudio de la relación entre la vegetación y los factores ambientales que determinan su distribuciónOne main aim of biogeography is to determine if species are randomly distributed or if there exist groups of species with common distributional patterns known as chorotypes. In this study, we determined through quantitative techniques if there exists such chorotypes for trees and shrubs in the transitional Mediterranean-temperate climatic zone of Chile, Eigth

  13. Vernal Keratoconjunctivitis in Kashmir: A temperate zone.

    Science.gov (United States)

    Sofi, Rayees Ahmad; Mufti, Asmat

    2016-12-01

    The objective of this study was to observe the clinical features of patients with vernal keratoconjunctivitis attending the Outpatient Department of a mobile eye unit, Directorate of Health Services, Jammu and Kashmir over a period of 1 year. The greater prevalence of VKC is seen in the regions with hot, humid climate, and higher load of airborne allergens. The clinical profile of this disease seems to have geographical variation. The study was conducted in the mobile eye unit, Directorate of Health Services, Kashmir, a comparatively cooler area. All the patients with vernal keratoconjunctivitis who presented to the OPD during this period were examined. The diagnosis of vernal keratoconjunctivitis was based on typical history, clinical features, and examination. All the patients with the complaints of itching, watering, and photophobia were examined. After proper history, clinical features, and ocular examination under slit lamp, the data were recorded for patients who were diagnosed with vernal keratoconjunctivitis. Of all the patients who had allergic ocular disorders, a total of 212 patients were diagnosed as cases with vernal keratoconjunctivitis. This is a non-interventional study, and the ethical clearance was obtained from the regulatory board of the hospital. The study abides by the tenets laid down in the declaration of Helsinki. During this 1-year period, 212 vernal keratoconjunctivitis patients were examined, of whom 155 (73 %) were males and 57 (27 %) were females. As per the age group, 40 % (85) of patients were in the age group of 11-15 years. 93 % (197) of patients had bilateral disease, and 7 % (15) had unilateral. It was seen that 75 % (159) had seasonal attack. Different types of disease were observed: 77 % (163) had bulbar disease, 7 % (15) had palpebral, and 16 % (34) had mixed disease. During this period, we noticed that VKC led to complications also. It was seen that 3 % (6) of patients had steroid induced glaucoma, 5 % (11) had developed cataract, 6 % (13) of patients had keratoconus, and 6 % (13) of patients had corneal scarring. Other complications were also seen. VKC is a bilateral disease. Males are affected more than females. Ocular complications were seen in around 30 % of patients. Visual impairment ranging from severe visual impairment to blindness was observed in 2 % of patients. VKC patients should be instructed to use medication under the supervision of an ophthalmologist. There is a need to assess disease severity in order to develop standardized guidelines based on the stage of vernal keratoconjunctivitis.

  14. Does outdoor work during the winter season protect against depression and mood difficulties?

    DEFF Research Database (Denmark)

    Hahn, Ina H; Grynderup, Matias Brødsgaard; Dalsgaard, Sofie B

    2011-01-01

    At temperate latitudes, 1-5% of the population suffer from winter depression; during winter, mood difficulties tend to increase but may be alleviated by bright light therapy. Unlike indoor workers, outdoor workers are exposed to therapeutic levels of sunlight during winter. We hypothesized...... that outdoor work may protect against mood difficulties and depression....

  15. Coastal Temperate Rainforest Symposium

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The North Pacific LCC is helping sponsor the April 2012 science symposium - Coastal Temperate Rainforests: Integrating Communities, Climate Science, and Resource...

  16. Sensitivity of WRF model estimates to various PBL parameterizations in different climatic zones over India

    Science.gov (United States)

    Gunwani, Preeti; Mohan, Manju

    2017-09-01

    In the present work sensitivity of Weather Research Forecasting (WRF) Model has been carried out using five planetary boundary layer (PBL) schemes - Yonsei University Scheme (YSU), Mellor-Yamada-Janjić scheme (MYJ), Aymmetric Convective Model version 2 (ACM2), Quasi Normal Scale Elimination scheme (QNSE), Mellor-Yamada-Nakanishi-Niino scheme (MYNN) in different climatic zones over India namely Tropical, Temperate and Arid for surface meteorological parameters, upper air variables and planetary boundary layer height during summer and winter season. The model outputs have been compared with observations through standard statistical measures. The aim is to study the relative performance of these schemes, selecting the best option climatic zone-wise and thereby minimizing uncertainty in model predictions. WRF model performance evaluation shows better agreement for temperature and relative humidity compared to wind speed. Overall for India, ACM2, QNSE show good performance for temperature and relative humidity whereas ACM2, MYNN show better performance for wind speed though these may vary for different climatic zones. Geopotential height and wind over 850 hPa is well simulated by ACM2 and MYNN over India. For PBL height ACM2, MYNN and MYJ works best for Chennai, New Delhi and Kolkata respectively during summer period. However, for winter period MYJ works best for Chennai while, QNSE works best for New Delhi and Kolkata. Considering all meteorological parameters together, it is seen that for arid zone ACM2, QNSE and MYJ schemes work reasonably well. For temperate zone, ACM2, QNSE and MYNN schemes show better results. For tropical zone all PBL schemes work closely. Hence, depending on the application, parameter and climate zone, this study provides suitable recommendations for choosing PBL schemes appropriately for each zone and parameter separately for the Indian region.

  17. Is the evaporation water loss of Knot Calidris canutus higher in tropical than in temperate climates?

    NARCIS (Netherlands)

    Verboven, N.; Piersma, T.

    1995-01-01

    To test whether Knot Calidris canutus wintering in the tropics suffer higher rates of water loss through evaporation than do Knot wintering at temperate latitudes, we tried to develop a physically realistic model to predict evaporative heat loss from air temperature, wind and humidity. In separate

  18. Seed quality of winter wheat varieties after black fallow depending on organo-mine­ral fertilizer application in the Left-Bank Forest-Steppe zone of Ukraine

    Directory of Open Access Journals (Sweden)

    С. В. Авраменко

    2017-09-01

    Full Text Available Purpose. To determine the effect of the basic organo-mineral fertilizer on the formation and stability of grain quality of winter wheat varieties in multiple crop rotation after black fallow as a predecessor. Methods. Field experiments were based on a multifactorial scheme using split-plot method with due regard to all requirements of the field experiment procedure, analysis of variance was used for statistical processing of the obtained results. Results. Investigation data was given concerning determination of grain quality indices in winter wheat varieties of diffe­rent ecotypes after black fallow as a predecessor depending on organo-mineral fertilizer application in the Left-Bank Forest-Steppe zone of Ukraine. In average for the period of investigation (2011–2015, the highest protein content in winter wheat grains was formed in no treatment variant [in such varieties as ‘Doridna’ (14.1%, ‘Dykanka’ (14.3% and ‘Levada’ (14.2%] and in case of organo-mineral fertilizer application [in the varieties ‘Hordovyta’ (14.0%, ‘Kalyta’ (14.0%, ‘Dykanka’ (14.7% and ‘Levada’ (14.6%]. The highest content of crude gluten in grains, without regard for the variant of the experiment, was found in the following varieties as ‘Dykanka’ (24.9–25.1% and ‘Levada’ (23.7–25.4%. Conclusions. It was established that the content of protein and crude gluten in grains as well as the falling number of winter wheat was highly dependent on such factors as the variety and the year of cultivation as compared to the fertilizer background. The following varieties as ‘Hordovyta’, ‘Mulan’, Dykanka’ and ‘Levada’ were very sensitive to the application of organo-mineral fertilizer for the protein content, while ‘Hordovyta’ (2.4%, ‘Levada’ (1.7%, ‘Borvii’ (1.2% and ‘Mulan’ (1.1% – for the crude gluten content.

  19. Variation in phytoplankton composition between two North Pacific frontal zones along 158°W during winter-spring 2008-2011

    Science.gov (United States)

    Howell, Evan A.; Bograd, Steven J.; Hoover, Aimee L.; Seki, Michael P.; Polovina, Jeffrey J.

    2017-01-01

    Data from three research cruises along the 158°W meridian through the North Pacific Subtropical Frontal Zone (STF) during spring 2008, 2009, and 2011 were used to estimate phytoplankton functional types and size classes. These groups were used to describe phytoplankton composition at the North Pacific Subtropical (STF) and Transition Zone Chlorophyll (TZCF) Fronts, which represent ecologically important large-scale features in the central North Pacific. Phytoplankton class composition was consistent at each front through time, yet significantly different between fronts. The STF contained lower integrated chlorophyll-a concentrations, with surface waters dominated by picophytoplankton and a deep chlorophyll maximum equally comprised of pico- and nanophytoplankton. The TZCF contained significantly higher concentrations of nanophytoplankton through the water column, specifically the prymnesiophyte group. Integrated chlorophyll-a concentrations at the TZCF were 30-90% higher than at the STF, with the dominant increase in the signal from the nanophytoplanktonic prymnesiophyte group. The meridional position of the STF was consistently located near 32°N through these three years, with the more spatially variable TZCF ranging from 2° to 4° further north of the STF. This variability in the frontal position of the TZCF may lead to ecological impacts though the food web. Continued in-situ and remote monitoring, specifically during El Niño and ENSO neutral phases, will provide additional ecological information to help understand mechanistic causes of phytoplankton variability in this important ecological region.

  20. Simulated Solute Tempering.

    Science.gov (United States)

    Denschlag, Robert; Lingenheil, Martin; Tavan, Paul; Mathias, Gerald

    2009-10-13

    For the enhanced conformational sampling in molecular dynamics (MD) simulations, we present "simulated solute tempering" (SST) which is an easy to implement variant of simulated tempering. SST extends conventional simulated tempering (CST) by key concepts of "replica exchange with solute tempering" (REST, Liu et al. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 13749). We have applied SST, CST, and REST to molecular dynamics (MD) simulations of an alanine octapeptide in explicit water. The weight parameters required for CST and SST are determined by two different formulas whose performance is compared. For SST only one of them yields a uniform sampling of the temperature space. Compared to CST and REST, SST provides the highest exchange probabilities between neighboring rungs in the temperature ladder. Concomitantly, SST leads to the fastest diffusion of the simulation system through the temperature space, in particular, if the "even-odd" exchange scheme is employed in SST. As a result, SST exhibits the highest sampling speed of the investigated tempering methods.

  1. Variation of respiratory syncytial virus and the relation with meteorological factors in different winter seasons.

    NARCIS (Netherlands)

    Meerhoff, T.J.; Paget, W.J.; Kimpen, J.L.; Schellevis, F.

    2009-01-01

    Background: Respiratory syncytial virus (RSV) is the most important viral agent causing severe respiratory disease in infants and children. In temperate climates, RSV activity typically peaks during winter. We have described the seasonal variation in RSV activity and investigated which

  2. Evaluation of tropically adapted straightbred and crossbred cattle: postweaning gain and feed efficiency when finished in a temperate climate.

    Science.gov (United States)

    Coleman, S W; Chase, C C; Phillips, W A; Riley, D G; Olson, T A

    2012-06-01

    Beef cows in the subtropical USA must be adapted to the stressors of the environment, typically supplied by using Brahman (Br) breeding. Calves produced in the region, however, are usually grown and finished in more temperate regions, and have a perceived reputation for poor ADG and feed efficiency during finishing. Compromised fertility and carcass quality often associated with the Br have increased interest in tropically adapted Bos taurus breed types. The objective of this study was to evaluate 3 breeds [An = Angus (Bos taurus, temperate); Br (B. indicus, tropical); and Ro = Romosinuano (B. taurus, tropical)] and all possible crosses during various segments of post-weaning growth, and for feed efficiency during the finishing phase. Steer calves (n = 473) born over 3 yr were weaned in late September, backgrounded for at least 21 d (BKG), shipped 2,025 km to El Reno, OK, in October, fed a preconditioning diet for 28 d (RCV), grazed wheat (Triticum aestivum L.) pasture from November to May (WHT), finished on a conventional feedlot diet (FIN), and serially harvested after approximately 95, 125, and 150 d on feed. Body weight and ADG during each segment were tested using a mixed model that included calf age at weaning, year (Y), breed of sire (SB), breed of dam (DB), and interactions. In addition, winter treatment (continuous wheat or reduced grazing of wheat with supplement) was included for the wheat and feedlot phases. Sire within SB × SB [and pen (barn × year) for feedlot phase] were considered random. The SB × DB interaction was significant for all traits (P residual feed intake. No heterosis was evident. These data show that in temperate zones, winter is the period when productivity of tropically adapted cattle is compromised.

  3. Englacial Hydrology of Temperate Glaciers

    Science.gov (United States)

    Fountain, A. G.; Creyts, T. T.

    2015-12-01

    The englacial region of temperate glaciers is generally treated as a passive conveyor of water from the surface to the bed. Consequently, few studies have examined this region and relatively little is known. This is an important issue because englacial processes probably exert a first order control on the distribution of water to the subglacial hydraulic system. Controlling the water distribution probably controls the type of subglacial hydraulic features present and therefore sliding behavior. Certainly, englacial conduits play a major, if not primary, role in conveying water in the ablation zone. In regions of over-deepenings, areas highly crevassed, or in the accumulation zone, the importance of englacial conduits is less clear. Field studies have shown that intersecting englacial passageways in these regions are relatively common, implying that large water fluxes can drain efficiently through a network of fractures. Hypothetically, efficient drainage systems composed of englacial conduits develop in response to point input of large surface water fluxes. Where input is small and distributed, common to highly crevassed areas or the accumulation zone, water is probably routed through a network of englacial fractures. Glacier geometry may also play a role. Conduits may not develop in the over-deepened (closed basins) regions of a glacier requiring another flow pathway. That englacial fractures exist and can convey water presents a promising alternative. Measured rates of flow in fractures strongly suggest laminar conditions and a sufficient fracture density exists to accommodate the estimated water flux generated upstream by surface melt. The slow flow rates do not generate sufficient viscous heat to compensate expected rates of closure by freezing, however field observations and seismic evidence point to spontaneous fracture formation at depth that must regenerate the fracture network. It is unfortunate that englacial investigations are ignored in favor of

  4. Comparison of seasonal soil microbial process in snow-covered temperate ecosystems of northern China.

    Directory of Open Access Journals (Sweden)

    Xinyue Zhang

    Full Text Available More than half of the earth's terrestrial surface currently experiences seasonal snow cover and soil frost. Winter compositional and functional investigations in soil microbial community are frequently conducted in alpine tundra and boreal forest ecosystems. However, little information on winter microbial biogeochemistry is known from seasonally snow-covered temperate ecosystems. As decomposer microbes may differ in their ability/strategy to efficiently use soil organic carbon (SOC within different phases of the year, understanding seasonal microbial process will increase our knowledge of biogeochemical cycling from the aspect of decomposition rates and corresponding nutrient dynamics. In this study, we measured soil microbial biomass, community composition and potential SOC mineralization rates in winter and summer, from six temperate ecosystems in northern China. Our results showed a clear pattern of increased microbial biomass C to nitrogen (N ratio in most winter soils. Concurrently, a shift in soil microbial community composition occurred with higher fungal to bacterial biomass ratio and gram negative (G- to gram positive (G+ bacterial biomass ratio in winter than in summer. Furthermore, potential SOC mineralization rate was higher in winter than in summer. Our study demonstrated a distinct transition of microbial community structure and function from winter to summer in temperate snow-covered ecosystems. Microbial N immobilization in winter may not be the major contributor for plant growth in the following spring.

  5. WINTER SAECULUM

    Directory of Open Access Journals (Sweden)

    Emil Mihalina

    2017-03-01

    Full Text Available Accumulated imbalances in the economy and on the markets cause specific financial market dynamics that have formed characteristic patterns kept throughout long financial history. In 2008 Authors presented their expectations of key macroeconomic and selected asset class markets developments for period ahead based on Saeculum theory. Use of term Secular describes a specific valuation environment during prolonged period. If valuations as well as selected macro variables are considered as a tool for understanding business cycles then market cycles become much more obvious and easily understandable. Therefore over the long run, certain asset classes do better in terms of risk reward profile than others. Further on, there is no need for frequent portfolio rebalancing and timing of specific investment positions within a particular asset class market. Current stage in cycle development suggests a need for reassessment of trends and prevailing phenomena due to cyclical nture of long lasting Saeculums. Paper reviews developments in recognizable patterns of selected metrics in current Winter Saeculum dominated with prevailing forces of delivering, deflation and decrease in velocity of money.

  6. Off-season uptake of nitrogen in temperate heath vegetation

    DEFF Research Database (Denmark)

    Andresen, Louise C.; Michelsen, Anders

    2005-01-01

    , and the graminoids Carex arenaria and Deschampsia flexuosa, showed high root uptake of both forms of nitrogen, both 1 day after labelling and after a month, in species specific temporal patterns. Plant uptake of 13C was not significant, providing no further evidence of intact uptake of glycine. Translocation....... The winter temperatures were similar to those of an average winter in the northern temperate region of Europe, with only few days of soil temperatures below zero or above 5 degrees C. The vegetation, consisting of the evergreen dwarf shrub Calluna vulgaris, the deciduous dwarf shrub Salix arenaria...

  7. Silviculture for restoration of degraded temperate and boreal forests

    Science.gov (United States)

    John A. Stanturf; Palle Madsen; Emile S. Gardiner

    2004-01-01

    Throughout the temperate and boreal zones, human intervention has influenced landscapes and forests for millennia. The degree of human disturbance has only been constrained by the technology and resources available to different cultures and by time since initial habitation. Humans have influenced forests by regulating populations of browsers, clearing for agriculture,...

  8. Unravelling Diurnal Asymmetry of Surface Temperature in Different Climate Zones.

    Science.gov (United States)

    Vinnarasi, R; Dhanya, C T; Chakravorty, Aniket; AghaKouchak, Amir

    2017-08-04

    Understanding the evolution of Diurnal Temperature Range (DTR), which has contradicting global and regional trends, is crucial because it influences environmental and human health. Here, we analyse the regional evolution of DTR trend over different climatic zones in India using a non-stationary approach known as the Multidimensional Ensemble Empirical Mode Decomposition (MEEMD) method, to explore the generalized influence of regional climate on DTR, if any. We report a 0.36 °C increase in overall mean of DTR till 1980, however, the rate has declined since then. Further, arid deserts and warm-temperate grasslands exhibit negative DTR trends, while the west coast and sub-tropical forest in the north-east show positive trends. This transition predominantly begins with a 0.5 °C increase from the west coast and spreads with an increase of 0.25 °C per decade. These changes are more pronounced during winter and post-monsoon, especially in the arid desert and warm-temperate grasslands, the DTR decreased up to 2 °C, where the rate of increase in minimum temperature is higher than the maximum temperature. We conclude that both maximum and minimum temperature increase in response to the global climate change, however, their rates of increase are highly local and depend on the underlying climatic zone.

  9. Land Cover Analysis of Temperate Asia

    Science.gov (United States)

    Justice, Chris

    1998-01-01

    Satellite data from the advanced very high resolution radiometer (AVHRR) instrument were used to produce a general land cover distribution of temperate Asia (referred to hence as Central Asia) from 1982, starting with the NOAA-7 satellite, and continuing through 1991, ending with the NOAA-11 satellite. Emphasis was placed upon delineating the and and semi-arid zones of Central Asia (largely Mongolia and adjacent areas), mapping broad categories of aggregated land cover, and upon studying photosynthetic capacity increases in Central Asia from 1982 to 1991.

  10. Kajian Pembuatan Cokelat Batang dengan Metode Tempering dan Tanpa Tempering

    OpenAIRE

    Eti Indarti; Normalina Arpi; Slamet Budijanto*

    2013-01-01

    This research is aimed to improve stability of milk chocolate bars by tempering process. The making of chocolate bars consisted of two formulations, namely a higher fat bar (40%) and low fat bar (21.5%).The study includes the chocolate bar preparation with and without tempering results. The melting point of milk chocolate bars that use cocoa butter tempering (L1) is higher than the milk chocolate bars that use fat without tempering (L2) for all treatments. Solid fat content (SFC) of F1 has hi...

  11. IS THE EVAPORATIVE WATER-LOSS OF KNOT CALIDRIS-CANUTUS HIGHER IN TROPICAL THAN IN TEMPERATE CLIMATES

    NARCIS (Netherlands)

    VERBOVEN, N; PIERSMA, T

    To test whether Knot Calidris canutus wintering in the tropics suffer higher rates of water loss through evaporation than do Knot wintering at temperate latitudes, we tried to develop a physically realistic model to predict evaporative heat loss from air temperature, wind and humidity. In separate

  12. Winter bird population studies and project prairie birds for surveying grassland birds

    Science.gov (United States)

    Daniel J. Twedt; Paul B. Hamel; Mark S. Woodrey

    2008-01-01

    We compared 2 survey methods for assessing winter bird communities in temperate grasslands: Winter Bird Population Study surveys are area-searches that have long been used in a variety of habitats whereas Project Prairie Bird surveys employ active-flushing techniques on strip-transects and are intended for use in grasslands.

  13. Potential energy expenditure by litter-roosting bats associated with temperature under leaf litter during winter

    Science.gov (United States)

    Roger W. Perry

    2013-01-01

    In temperate portions of North America, some bats that remain active during winter undergo short periods of hibernation below leaf litter on the forest floor during episodes of below-freezing weather. These winter roosts may provide above-freezing conditions, but the thermal conditions under leaf litter are unclear. Further, little is known of the relationship between...

  14. Independently founded populations of Sclerotinia sclerotiorum from a tropical and a temperate region have similar genetic structure

    OpenAIRE

    Lehner,Miller S.; de Paula J?nior, Trazilbo J.; Del Ponte, Emerson M.; MIZUBUTI,EDUARDO S. G.; Sarah J. Pethybridge

    2017-01-01

    Sclerotinia sclerotiorum populations from tropical agricultural zones have been suggested to be more variable compared to those from temperate zones. However, no data were available comparing populations from both zones using the same set of markers. In this study, we compared S. sclerotiorum populations from the United States of America (USA, temperate) and southeast Brazil (tropical) using the frequency of mycelial compatibility groups (MCGs) and 13 microsatellite (SSR) markers. Populations...

  15. Multiple satellite-based analysis reveals complex climate effects of temperate forests and related energy budget

    Science.gov (United States)

    Ma, Wei; Jia, Gensuo; Zhang, Anzhi

    2017-04-01

    Forest conversion-driven biophysical processes have been examined in various case studies that largely depend on sensitivity analysis of climate modeling. However, much remains unknown in the real world due to the complicated process and uncertainty in magnitude, especially in the temperate bioclimate regions. This study applied satellite-based observation to investigate the biophysical climate response to potential forest conversion in China, especially on the spatial and temporal patterns and underlying mechanisms. We evaluated the differences of land surface temperature (ΔLST) between adjacent forest and cropland, in terms of the latitudinal and seasonal patterns. Compared to cropland, the temperate forest to the south of 40°N showed the cooling effect of -0.61 ± 0.02°C (95% confidence interval, and hereafter), and it presented the warming effect of 0.48 ± 0.06°C to the north of 48°N (the transition zone was between 40°N and 48°N). Seasonal analysis further demonstrated that the cooling effects of temperate forest in China in spring (March, April, May), summer (June, July, August), and autumn (September, October, November) were -0.53 ± 0.02°C, -0.55 ± 0.02°C, and -0.30 ± 0.02°C, respectively, while the forest caused the warming effect of 0.10 ± 0.04°C in winter (December, January, February). However, the biophysical climate response to forest conversion in temperate regions was complex and showed highly spatial and temporal heterogeneity. We further assessed the role of two major biophysical processes, i.e., albedo and evapotranspiration (ET), in shaping land surface temperature from surface energy budget perspective. Results showed that the latitudinal, seasonal, and spatiotemporal patterns of ΔLST was determined by the net effect of ET-induced latent heat changes and albedo-induced solar radiation absorption changes.

  16. Vegetation zones in changing climate

    Science.gov (United States)

    Belda, Michal; Holtanova, Eva; Halenka, Tomas; Kalvova, Jaroslava

    2017-04-01

    of individual types, in the continental scale some shifts of boundaries between the selected types can be studied as well providing the information on climate change signal. The shift of the boundary between the boreal zone and continental temperate zone to the north is clearly seen in most simulations as well as eastern move of the boundary of the maritime and continental type of temperate zone. However, there can be quite clear problem with model biases in climate types association. When analysing climate types in Europe and their shifts under climate change using Köppen-Trewartha classification (KTC), for the temperate climate type there are subtypes defined following the continentality patterns, and we can see their generally meridionally located divide across Europe shifted to the east. There is a question whether this is realistic or rather due to the simplistic condition in KTC following the winter minimum temperature, while other continentality indices consider rather the amplitude of temperature during the year. This leads us to connect our analysis of climate change effects using climate classification to the more detailed analysis of continentality patterns development in Europe to provide better insight on the climate regimes and to verify the continentality conditions, their definitions and climate change effects on them. The comparison of several selected continentality indices is shown.

  17. Shifts in Köppen-Geiger climate zones over southern Africa in relation to key global temperature goals

    Science.gov (United States)

    Engelbrecht, Christien J.; Engelbrecht, Francois A.

    2016-01-01

    Potential changes in Köppen-Geiger climate zones over southern Africa (Africa south of 22 °S) under future climate change are investigated using an ensemble of high-resolution projections of a regional climate model. The projections are performed under the A2 scenario of the Special Report on Emission Scenarios (SRES), and changes are presented for those times in the future when the increase in global average surface temperature reaches thresholds of 1, 2, and 3 °C, relative to the present-day baseline climatology. Widespread shifts in climate regimes are projected, of which the southern and eastern expansion of the hot desert and hot steppe zones is the most prominent. From occupying 33.1 and 19.4 % of southern Africa under present-day climate, these regions are projected to occupy between 47.3 and 59.7 % (hot desert zone) and 24.9 and 29.9 % (hot steppe zone) of the region in a future world where the global temperature has increased by 3 °C. The cold desert and cold steppe zones are projected to decrease correspondingly. The temperate regions of eastern South Africa, the Cape south coast, and winter rainfall region of the southwestern Cape are also projected to contract. An expansion of the hot steppe zone into the cold steppe and temperate zones may favor the intrusion of trees (and therefore the savanna biome) into the most pristine grasslands of southern Africa. However, the correlative climate-vegetation approach of using projected changes in Köppen-Geiger zones to infer future vegetation patterns is of limited value in the savanna complex of southern Africa, where complex feedbacks occur between carbon dioxide (CO2) concentrations, trees, C4 grasses, fire, and climate. The present-day temperate Cape Fynbos regime may come under increasing pressure as the encompassing temperate zone is invaded mainly from the east by the hot steppe climate regime under climate change, with the incidence of Fynbos fires also becoming more likely in a generally warmer and

  18. Assessment of Natural Ventilation Potential for Residential Buildings across Different Climate Zones in Australia

    Directory of Open Access Journals (Sweden)

    Zijing Tan

    2017-09-01

    Full Text Available In this study, the natural ventilation potential of residential buildings was numerically investigated based on a typical single-story house in the three most populous climate zones in Australia. Simulations using the commercial simulation software TRNSYS (Transient System Simulation Tool were performed for all seasons in three representative cities, i.e., Darwin for the hot humid summer and warm winter zone, Sydney for the mild temperate zone, and Melbourne for the cool temperate zone. A natural ventilation control strategy was generated by the rule-based decision-tree method based on the local climates. Natural ventilation hour (NVH and satisfied natural ventilation hour (SNVH were employed to evaluate the potential of natural ventilation in each city considering local climate and local indoor thermal comfort requirements, respectively. The numerical results revealed that natural ventilation potential was related to the local climate. The greatest natural ventilation potential for the case study building was observed in Darwin with an annual 4141 SNVH out of 4728 NVH, while the least natural ventilation potential was found in the Melbourne case. Moreover, summer and transition seasons (spring and autumn were found to be the optimal periods to sustain indoor thermal comfort by utilising natural ventilation in Sydney and Melbourne. By contrast, natural ventilation was found applicable over the whole year in Darwin. In addition, the indoor operative temperature results demonstrated that indoor thermal comfort can be maintained only by utilising natural ventilation for all cases during the whole year, except for the non-natural ventilation periods in summer in Darwin and winter in Melbourne. These findings could improve the understanding of natural ventilation potential in different climates, and are beneficial for the climate-conscious design of residential buildings in Australia.

  19. Cold in the common garden: comparative low-temperature tolerance of boreal and temperate conifer foliage

    Science.gov (United States)

    G. Richard Strimbeck; Trygve D. Kjellsen; Paul G. Schaberg; Paula F. Murakami

    2007-01-01

    Because they maintain green foliage throughout the winter season, evergreen conifers may face special physiological challenges in a warming world. We assessed the midwinter low-temperature (LT) tolerance of foliage from eight temperate and boreal species in each of the genera Abies, Picea, and Pinus growing in an arboretum in...

  20. Winter maintenance performance measure.

    Science.gov (United States)

    2016-01-01

    The Winter Performance Index is a method of quantifying winter storm events and the DOTs response to them. : It is a valuable tool for evaluating the States maintenance practices, performing post-storm analysis, training : maintenance personnel...

  1. Concussion in Winter Sports

    Science.gov (United States)

    ... this? Submit Button Past Emails Concussion in Winter Sports Recommend on Facebook Tweet Share Compartir Get prepared ... to enjoy, practice, and compete in various winter sports. There’s no doubt that these sports are a ...

  2. Analysis of yield and plant traits of oilseed rape (Brassica napus L. cultivated in temperate region in light of the possibilities of sowing in arid areas

    Directory of Open Access Journals (Sweden)

    Tadeusz Zając

    2016-12-01

    Full Text Available This work is a review of selected literature on the species of Brassica with the greatest economic significance. Oilseed rape (Brassica napus ssp. oleifera currently ranks third worldwide among oilseed crops used for oil production and is the most important in the temperate zone. The manifold uses of rape include not only human consumption of oil, but also the use of post-extraction meal to feed livestock as well as industrial applications as a source of bioenergy or cellulose. The improvement in the economic position of rape among crop plants is also due to the doubling of its yield between 1970 and 2009; the average annual increase in seed yield worldwide was 27 kg ha−1 yr−1. The yield level in Europe exceeds the average yields achieved in the world, particularly in Asia. Recently, the cultivation of oilseed rape was started on a relatively large acreage in Iran where the yield amounted 2.1 t ha−1, exceeding the yields of China and India. In Poland, the acreage of oilseed rape cultivation between 1965 and 2013 increased 3–4 times, and during this period the annual increase in seed yield was 29 kg ha−1 yr−1. Under the field conditions of the temperate climate zone, winter oilseed rape yield is mainly determined by agro-climatic conditions during the growing period, the level of nitrogen fertilization, and the production potential of varieties, which is currently highest in hybrids. There is a noticeable tendency of hybrids towards formation of more siliques by individual oilseed plants. Different production categories of plants appear in a rape crop. Semi-dwarf varieties of winter rapeseed are distinguished by greater silique density, particularly on the main shoot. Moreover, these hybrids are characterized by faster growth of the root system, which enables them to take up nitrogen from the soil more efficiently.

  3. Fruiting and flushing phenology in Asian tropical and temperate forests: implications for primate ecology.

    Science.gov (United States)

    Hanya, Goro; Tsuji, Yamato; Grueter, Cyril C

    2013-04-01

    In order to understand the ecological adaptations of primates to survive in temperate forests, we need to know the general patterns of plant phenology in temperate and tropical forests. Comparative analyses have been employed to investigate general trends in the seasonality and abundance of fruit and young leaves in tropical and temperate forests. Previous studies have shown that (1) fruit fall biomass in temperate forest is lower than in tropical forest, (2) non-fleshy species, in particular acorns, comprise the majority of the fruit biomass in temperate forest, (3) the duration of the fruiting season is shorter in temperate forest, and (4) the fruiting peak occurs in autumn in most temperate forests. Through our comparative analyses of the fruiting and flushing phenology between Asian temperate and tropical forests, we revealed that (1) fruiting is more annually periodic (the pattern in one year is similar to that seen in the next year) in temperate forest in terms of the number of fruiting species or trees, (2) there is no consistent difference in interannual variations in fruiting between temperate and tropical forests, although some oak-dominated temperate forests exhibit extremely large interannual variations in fruiting, (3) the timing of the flushing peak is predictable (in spring and early summer), and (4) the duration of the flushing season is shorter. The flushing season in temperate forests (17-28 % of that in tropical forests) was quite limited, even compared to the fruiting season (68 %). These results imply that temperate primates need to survive a long period of scarcity of young leaves and fruits, but the timing is predictable. Therefore, a dependence on low-quality foods, such as mature leaves, buds, bark, and lichens, would be indispensable for temperate primates. Due to the high predictability of the timing of fruiting and flushing in temperate forests, fat accumulation during the fruit-abundant period and fat metabolization during the

  4. Early wound reactions of Japanese maple during winter dormancy – the effect of two contrasting temperature regimes

    NARCIS (Netherlands)

    Copini, P.; Ouden, den J.; Decuyper, M.; Mohren, G.M.J.; Loomans, A.J.M.; Sass-Klaassen, U.G.W.

    2014-01-01

    During winter dormancy, temperate trees are capable of only a restricted response to wounding. Depending on the ambient temperature during winter dormancy, wounded trees may start compartmentalization, e.g. by producing inhibitory compounds, but it is thought that processes involving cell

  5. Citril finches during the winter: patterns of distribution, the role of pines and implications for the conservation of the species

    Directory of Open Access Journals (Sweden)

    Borras, A.

    2010-06-01

    Full Text Available The Citril finch Serinus citrinella is a Paleartic endemic species that breeds in the subalpine mountain zones of western temperate Europe. The species seems to be suffering a serious decline in its northern range, mainly in the Black Forest and the NE of the Alps. Numerous reasons have been provided for this decline, but all of them have been related to breeding habitats. Given that the species undergoes an altitudinal migration and that during winter it may use very different habitats, a sound knowledge of the distribution patterns and habitats used outside the breeding period is needed to conduct adequate conservation policies and management. This information, however, is largely lacking. The aim of this paper was to determine the current habitat used by Citril finches in north-eastern Spain during the winter, to analyse habitat suitability and to study movements, by investigating the origin of birds that overwinter in Catalonia. Citril finch distribution was modelled using both discriminant analysis and maximum entropy modelling, on the basis of species occurrences during winter in Catalonia (data from 1972-2009. Results showed that the presence of two tree species, Black pine (Pinus nigra subsp. salzmanii and Scots pine (Pinus sylvestris, both as part of mixed open forests, and the presence of abundant farmland and arvensic plants -the two vegetation units located in a typical submediterranean context, where the warm temperatures (sunny days in late winter permit the cones to open-, were the ecological and bioclimatic variables that explain the distribution model. All these variables in tandem seem to be the key for the current potential distribution of the Citril finch in winter (AUCscores: training data AUC= 0.955; test data AUC = 0.953. We analyzed recoveries (N = 238 of 2,368 birds ringed at wintering grounds and 12,648 birds ringed at subalpine localities in the adjacent Pyrenees from 1977-2004. We found that in the study area, we

  6. Kajian Pembuatan Cokelat Batang dengan Metode Tempering dan Tanpa Tempering

    Directory of Open Access Journals (Sweden)

    Eti Indarti

    2013-02-01

    Full Text Available This research is aimed to improve stability of milk chocolate bars by tempering process. The making of chocolate bars consisted of two formulations, namely a higher fat bar (40% and low fat bar (21.5%.The study includes the chocolate bar preparation with and without tempering results. The melting point of milk chocolate bars that use cocoa butter tempering (L1 is higher than the milk chocolate bars that use fat without tempering (L2 for all treatments. Solid fat content (SFC of F1 has higher solid phase at room temperature (55-60% in all treatments compared with milk chocolate bar F2 (40-43% and chocolate produced by UKM (Malaysia 40-48 % and soccolatte 35-38% at the same temperature (350C. Blooming was not formed on the milk chocolate bars containing cocoa butter L1, while the milk chocolate bars showed blooming with L2 treatment. Keywords: chocolate bar, tempering, moulding, melting point, solid fat content, blooming

  7. Phenology of temperate trees in tropical climates

    Science.gov (United States)

    Borchert, Rolf; Robertson, Kevin; Schwartz, Mark D.; Williams-Linera, Guadalupe

    2005-09-01

    Several North American broad-leaved tree species range from the northern United States at ˜47°N to moist tropical montane forests in Mexico and Central America at 15-20°N. Along this gradient the average minimum temperatures of the coldest month (T Jan), which characterize annual variation in temperature, increase from -10 to 12°C and tree phenology changes from deciduous to leaf-exchanging or evergreen in the southern range with a year-long growing season. Between 30 and 45°N, the time of bud break is highly correlated with T Jan and bud break can be reliably predicted for the week in which mean minimum temperature rises to 7°C. Temperature-dependent deciduous phenology—and hence the validity of temperature-driven phenology models—terminates in southern North America near 30°N, where T Jan>7°C enables growth of tropical trees and cultivation of frost-sensitive citrus fruits. In tropical climates most temperate broad-leaved species exchange old for new leaves within a few weeks in January-February, i.e., their phenology becomes similar to that of tropical leaf-exchanging species. Leaf buds of the southern ecotypes of these temperate species are therefore not winter-dormant and have no chilling requirement. As in many tropical trees, bud break of Celtis, Quercus and Fagus growing in warm climates is induced in early spring by increasing daylength. In tropical climates vegetative phenology is determined mainly by leaf longevity, seasonal variation in water stress and day length. As water stress during the dry season varies widely with soil water storage, climate-driven models cannot predict tree phenology in the tropics and tropical tree phenology does not constitute a useful indicator of global warming.

  8. Diversity and abundance of photosynthetic sponges in temperate Western Australia

    Directory of Open Access Journals (Sweden)

    Brümmer Franz

    2009-02-01

    Full Text Available Abstract Background Photosynthetic sponges are important components of reef ecosystems around the world, but are poorly understood. It is often assumed that temperate regions have low diversity and abundance of photosynthetic sponges, but to date no studies have investigated this question. The aim of this study was to compare the percentages of photosynthetic sponges in temperate Western Australia (WA with previously published data on tropical regions, and to determine the abundance and diversity of these associations in a range of temperate environments. Results We sampled sponges on 5 m belt transects to determine the percentage of photosynthetic sponges and identified at least one representative of each group of symbionts using 16S rDNA sequencing together with microscopy techniques. Our results demonstrate that photosynthetic sponges are abundant in temperate WA, with an average of 63% of sponge individuals hosting high levels of photosynthetic symbionts and 11% with low to medium levels. These percentages of photosynthetic sponges are comparable to those found on tropical reefs and may have important implications for ecosystem function on temperate reefs in other areas of the world. A diverse range of symbionts sometimes occurred within a small geographic area, including the three "big" cyanobacterial clades, Oscillatoria spongeliae, "Candidatus Synechococcus spongiarum" and Synechocystis species, and it appears that these clades all occur in a wide range of sponges. Additionally, spongin-permeating red algae occurred in at least 7 sponge species. This study provides the first investigation of the molecular phylogeny of rhodophyte symbionts in sponges. Conclusion Photosynthetic sponges are abundant and diverse in temperate WA, with comparable percentages of photosynthetic to non-photosynthetic sponges to tropical zones. It appears that there are three common generalist clades of cyanobacterial symbionts of sponges which occur in a wide

  9. Winters fuels report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-27

    The outlook for distillate fuel oil this winter is for increased demand and a return to normal inventory patterns, assuming a resumption of normal, cooler weather than last winter. With industrial production expected to grow slightly from last winter`s pace, overall consumption is projected to increase 3 percent from last winter, to 3.4 million barrels per day during the heating season (October 1, 1995-March 31, 1996). Much of the supply win come from stock drawdowns and refinery production. Estimates for the winter are from the Energy Information Administration`s (EIA) 4th Quarter 1995 Short-Tenn Energy Outlook (STEO) Mid-World Oil Price Case forecast. Inventories in place on September 30, 1995, of 132 million barrels were 9 percent below the unusually high year-earlier level. Inventories of high-sulfur distillate fuel oil, the principal type used for heating, were 13 percent lower than a year earlier. Supply problems are not anticipated because refinery production and the ready availability of imports should be adequate to meet demand. Residential heating off prices are expected to be somewhat higher than last winter`s, as the effects of lower crude oil prices are offset by lower distillate inventories. Heating oil is forecast to average $0.92 per gallon, the highest price since the winter of 1992-93. Diesel fuel (including tax) is predicted to be slightly higher than last year at $1.13 per gallon. This article focuses on the winter assessment for distillate fuel oil, how well last year`s STEO winter outlook compared to actual events, and expectations for the coming winter. Additional analyses include regional low-sulfur and high-sulfur distillate supply, demand, and prices, and recent trends in distillate fuel oil inventories.

  10. Impact of special early harvest seasons on subarctic-nesting and temperate-nesting Canada geese

    Science.gov (United States)

    Sheaffer, S.E.; Kendall, W.L.; Bowers, E. Frank

    2005-01-01

    Dramatic changes in wintering distributions of Canada geese (Branta canadensis) have occurred over the past 50 years in eastern North America. Declines in numbers of subarctic-nesting geese wintering in southern states, and increases in numbers wintering in northern regions, have resulted in a northern shift in winter distributions. In contrast, numbers of temperate-nesting geese have increased throughout eastern North America. Management efforts to control overabundant temperate-nesting flocks have included the establishment of special early harvest seasons in September. However, the effect of early seasons on survival and harvest of subarctic-nesting populations has not been documented. Understanding the timing of migration movements and the fidelity of subarctic-nesting flocks to terminal winter refuges in the Southeast also is necessary to design early harvest seasons that target temperate-nesting flocks and protect subarctic-nesting populations. We used recoveries of marked geese to estimate survival and harvest rates before and after implementation of early harvest seasons within the Mississippi Flyway during 1976-1999. In addition, we used observations of neck-banded geese from the Southern James Bay Population (SJBP) to evaluate the hypothesis that subarctic-nesting geese arriving prior to mid-December on several key terminal winter refuges in the Southeast (early arriving migrants) were more likely to return to those refuges in subsequent years than were migrants, arriving after mid-December (late arriving migrants). September seasons during 1987-1994 were a minor source of mortality for subarctic-nesting populations and accounted for migrants had higher survival and higher return probabilities than did late arriving migrants or geese that failed to return, numbers of geese wintering on southeastern refuges likely declined because < 60% of the surviving geese affiliated with the refuges would return in a given year and because of lower survival for geese

  11. Protective coating of austenitic steel using robotized GMAW temper-bead technique; Rechargement d'inox austenitique en MAG temperbead robotise

    Energy Technology Data Exchange (ETDEWEB)

    Carpreau, J.M. [Electricite de France (EDF/R and D), Recherche et Developpement, 92 - Chatou (France); Dainelli, P. [Institut de Soudure, 57 - Yutz (France)

    2009-07-15

    This paper summarises experimental results obtained in a study of GMAW temper-bead on low alloyed steel with austenitic consumables. Temper-bead on low alloyed steel with austenitic consumables is mainly used for repairing operations of heavy components such as vessel reactor of nuclear power plants. Experimental work aims at showing the performance of GMAW compared to GTAW and the consequences of GMAW temper-bead on 2OMND5 heat affected zones. (authors)

  12. Effect of climate, intra and inter-annual variability, on nutrients emission (C,N, P) in stream water: lessons from an agricultural long term observatory of the temperate zone

    Science.gov (United States)

    Gascuel-Odoux, Chantal; Remi, Dupas; Patrick, Durand; Ophélie, Fovet; Gerard, Gruau; Anne, Jaffrezic; Guillaume, Humbert; Philippe, Merot; Gu, Sen

    2016-04-01

    Agriculture greatly contributes to modify C, N and P cycles, particularly in animal breeding regions due to high inputs. Climatic conditions, intra and inter-annual variabilities, modify nutrient stream water emissions, acting in time on transfer and transformation, accumulation and mobilization processes, connecting and disconnecting in time different compartments (soil, riparian areas, groundwater). In agricultural catchments, nutrient perturbations are dominated by agricultural land use, and decoupling human activities and climate effects is far from easy. Climate change generally appears as a secondary driver compared to land use. If studied, generally only one nutrient is considered. Only long term, high frequency and multiple element data series can decouple these two drivers. The Kervidy-Naizin watershed belongs to the AgrHyS environmental research observatory (http://www6.inra.fr/ore_agrhys_eng), itself included in RBV (French catchment network of the CZO). On this catchment, 6 years of daily data on DOC, NO3, SRP, TP concentrations allow us to analyze the effect of seasonal and inter-annual climatic variabilities on water quality (C, N, P). Different papers have been published on the effect of climate on nitrate (Molenat et al, 2008), SRP and TP (Dupas et al, 2015) and DOC (Humbert et al, 2015). We will present first results comparing the effect of climate on these three major solute forms of C, N and P. While C and P dynamics are very close and controlled by fluctuation of water table downslope, i.e. in riparian areas, mobilizing C and P in time, nitrate dynamics is controlled by GW dynamics upslope acting as the major N reservoir. As example, the dryness conditions in summer appears a key factor of the C and P emissions in autumn. All the three solute forms interact when anoxic conditions are observed in riparian zones. These basic processes explain how climatic variability can influence and explain interactions between C, N and P emissions in stream

  13. Sub-zero cold tolerance of Spartina pectinata (prairie cordgrass) and Miscanthus × giganteus: candidate bioenergy crops for cool temperate climates.

    Science.gov (United States)

    Friesen, Patrick C; Peixoto, Murilo de Melo; Lee, D K; Sage, Rowan F

    2015-07-01

    Miscanthus × giganteus grown in cool temperate regions of North America and Europe can exhibit severe mortality in the year after planting, and poor frost tolerance of leaves. Spartina pectinata (prairie cordgrass), a productive C4 perennial grass native to North America, has been suggested as an alternative biofuel feedstock for colder regions; however, its cold tolerance relative to M. × giganteus is uncertain. Here, we compare the cold tolerance thresholds for winter-dormant rhizomes and spring/summer leaves of M. × giganteus and three accessions of S. pectinata. All genotypes were planted at a field site in Ontario, Canada. In November and February, the temperatures corresponding to 50% rhizome mortality (LT(50)) were near -24°C for S. pectinata and -4°C for M. × giganteus. In late April, the LT50 of rhizomes rose to -10°C for S. pectinata but remained near -4°C for M. × giganteus. Twenty percent of the M. × giganteus rhizomes collected in late April were dead while S. pectinata rhizomes showed no signs of winter injury. Photosynthesis and electrolyte leakage measurements in spring and summer demonstrate that S. pectinata leaves have greater frost tolerance in the field. For example, S. pectinata leaves remained viable above -9°C while the mortality threshold was near -5°C for M. × giganteus. These results indicate M. × giganteus will be unsuitable for production in continental interiors of cool-temperate climate zones unless freezing and frost tolerance are improved. By contrast, S. pectinata has the freezing and frost tolerance required for a higher-latitude bioenergy crop. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  14. Seasonal Variation of Carbon Metabolism in the Cambial Zone of Eucalyptus grandis.

    Science.gov (United States)

    Budzinski, Ilara G F; Moon, David H; Lindén, Pernilla; Moritz, Thomas; Labate, Carlos A

    2016-01-01

    Eucalyptus species are the most widely hardwood planted in the world. It is one of the successful examples of commercial forestry plantation in Brazil and other tropical and subtropical countries. The tree is valued for its rapid growth, adaptability and wood quality. Wood formation is the result of cumulative annual activity of the vascular cambium. This cambial activity is generally related to the alternation of cold and warm, and/or dry and rainy seasons. Efforts have focused on analysis of cambial zone in response to seasonal variations in trees from temperate zones. However, little is known about the molecular changes triggered by seasonal variations in trees from tropical countries. In this work we attempted to establish a global view of seasonal alterations in the cambial zone of Eucalyptus grandis Hill ex Maiden, emphasizing changes occurring in the carbon metabolism. Using transcripts, proteomics and metabolomics we analyzed the tissues harvested in summer-wet and winter-dry seasons. Based on proteomics analysis, 70 proteins that changed in abundance were successfully identified. Transcripts for some of these proteins were analyzed and similar expression patterns were observed. We identified 19 metabolites differentially abundant. Our results suggest a differential reconfiguration of carbon partioning in E. grandis cambial zone. During summer, pyruvate is primarily metabolized via ethanolic fermentation, possibly to regenerate NAD(+) for glycolytic ATP production and cellular maintenance. However, in winter there seems to be a metabolic change and we found that some sugars were highly abundant. Our results revealed a dynamic change in E. grandis cambial zone due to seasonality and highlight the importance of glycolysis and ethanolic fermentation for energy generation and maintenance in Eucalyptus, a fast growing tree.

  15. Interspecific variation in total phenolic content in temperate brown algae

    Directory of Open Access Journals (Sweden)

    Anna Maria Mannino

    2017-09-01

    Full Text Available Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae (Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the sheet-like alga D. polypodioides, living in the upper infralittoral zone, showed the highest concentration of phenolic compounds. These results are in agreement with the hypothesis that total phenolic content in temperate brown algae is influenced by a combination of several factors, such as growth form, depth, and exposition to solar radiation.

  16. Climate change effects on reference crop evapotranspiration across different climatic zones of China during 1956-2015

    Science.gov (United States)

    Fan, Junliang; Wu, Lifeng; Zhang, Fucang; Xiang, Youzhen; Zheng, Jing

    2016-11-01

    Global climate change has been an increasing challenge to agricultural ecosystems, which will significantly affect the reference crop evapotranspiration (ET0) and subsequently crop water requirements. In this study, the temporal trends and magnitudes of key climatic variables and the accompanying effects on ET0 during 1956-2015 were evaluated at 200 meteorological stations across the temperate continental zone (TCZ), temperate monsoon zone (TMZ), mountain plateau zone (MPZ), and subtropical monsoon zone (SMZ) of China. Results show that maximum and minimum temperatures have increased significantly over the past 60 years, whilst relative humidity, wind speed and sunshine hour exhibited significant decreasing trends across all climatic zones. The overall decreasing trends in annual ET0 were more pronounced than the increasing trends, whereas more increasing trends were found in spring and winter. Abrupt changes for climatic variables and ET0 series were detected in 1990s in the MPZ, while in 1980s in the other climatic zones mainly due to the aggregated emission of greenhouse gases and air pollution from energy consumption in recent decades. Relative humidity was the most sensitive climatic variable in all climatic zones except for the MPZ where ET0 was most sensitive to sunshine hour. However, ET0 had different responses to changing climatic variables in different regions and climatic conditions. The negative contribution of wind speed to the decrease in ET0 was greater than the other climatic variables in the TCZ and the TMZ, whilst the significant increase in minimum temperature and the decrease in sunshine hour contributed most to increasing ET0 in the MPZ and to decreasing ET0 in the SMZ, respectively. Although ET0 displayed a generally decreasing trend during 1956-2015, there was a significantly increasing trend from 1985 to 2015 across China except for the SMZ, especially in the arid and semi-arid zones of China during dry seasons (spring and winter). This may

  17. Mid-winter Waterfowl Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Mid-winter Waterfowl Survey is a nationwide effort to survey waterfowl in areas of major concentration on their wintering grounds and provide winter distribution...

  18. Winter Bottom Trawl Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were covered...

  19. Deer Wintering Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — Deer winter habitat is critical to the long term survival of white-tailed deer (Odocoileus virginianus) in Vermont. Being near the northern extreme of the...

  20. Confounded winter and spring phenoclimatology on large herbivore ranges

    Science.gov (United States)

    Christianson, David; Klaver, Robert W.; Middleton, Arthur; Kauffman, Matthew

    2013-01-01

    Annual variation in winter severity and growing season vegetation dynamics appear to influence the demography of temperate herbivores but parsing winter from spring effects requires independent metrics of environmental conditions specific to each season. We tested for independence in annual variation amongst four common metrics used to describe winter severity and early growing season vegetation dynamics across the entire spatial distribution of elk (Cervus elaphus) in Wyoming from 1989 to 2006. Winter conditions and early growing season dynamics were correlated in a specific way. Winters with snow cover that ended early tended to be followed by early, but slow, rises in the normalized difference vegetation index (NDVI), while long winters with extended periods of snow cover were often followed by late and rapid rises in NDVI. Across the 35 elk ranges, 0.4–86.8 % of the variation in the rate of increase in NDVI’s in spring was explained by the date snow cover disappeared from SNOTEL stations. Because phenoclimatological metrics are correlated across seasons and shifting due to climate change, identifying environmental constraints on herbivore fitness, particularly migratory species, is more difficult than previously recognized.

  1. Silicon pools in human impacted soils of temperate zones

    National Research Council Canada - National Science Library

    Vandevenne, F. I; Barão, L; Ronchi, B; Govers, G; Meire, P; Kelly, E. F; Struyf, E

    2015-01-01

    .... This has potential consequences for plant‐Si availability, agricultural yields, and coastal eutrophication, as Si is a beneficial element for many crop plants and an essential nutrient for diatom growth...

  2. Will afforestation in temperate zones warm the earth?

    Science.gov (United States)

    David B. South; Xuhui Lee; Michael G. Messina

    2012-01-01

    For decades, forest researchers have known that afforestation can lower the surface albedo and that landscapes with low albedo will absorb more solar radiation than more reflective surfaces. As a result, afforestation will typically darken the surface of the Earth (when compared to grasslands or deserts). This darkening of the landscape can be measured and the local...

  3. Introduction: Forest restoration in temperate and boreal zones

    Science.gov (United States)

    Emile Gardiner; Katrine Hahn; Magnus Löf

    2003-01-01

    The past decade has witnessed an acceleration of forest restoration activities around the globe. Afforestation of former agricultural land, rehabilitation of natural forest processes and structures at the stand and landscape levels, and conversion of single-species plantations to mixed-species stands are among the prominent types of restoration practices currently...

  4. Habitat fragmentation in the temperate zone: a perspective for managers

    Science.gov (United States)

    John Faaborg; Margaret Brittingham; Therese Donovan; John Blake

    1993-01-01

    Habitat fragmentation occurs when a large, fairly continuous tract of vegetation is converted to other vegetation types such that only scattered fragments of the original type remain. Problems associated with habitat fragmentation include overall habitat loss, increase in edge habitat and edge effects (particularly higher parasitism and nest predation rates), and...

  5. Restoration Concepts for Temperate and Boreal Forests of North America and Western Europe

    Science.gov (United States)

    John A. Stanturf; P. Madsen

    2002-01-01

    Throughout the boreal and temperate zones, forest restoration efforts attempt to counteract negative effects of conversion to other land use (afforestation and remediation) and disturbance and stress on existing forests (rehabilitation). Appropriate silvicultural practices can be designed for any forest restoration objective. Most common objectives include timber,...

  6. Coastal karren features in temperate microtidal settings: spatial organization and temporal evolution

    Directory of Open Access Journals (Sweden)

    Lluís Gómez-Pujol

    2010-04-01

    Full Text Available Basin pools are the diagnostic feature of Coastal Karren landscape at temperate settings. According to the size and connectivity parameters four morphological zones are identified along limestone coastal profiles. Each zone reflects the balance between the effects of physical and chemical weathering-erosion agents. Broadly, marine abrasion, bioerosion and biological driven solution show a larger influence seaward, whereas non-biological driven solution enhances its participation landward

  7. Biochar boosts tropical but not temperate crop yields

    Science.gov (United States)

    Jeffery, Simon; Abalos, Diego; Prodana, Marija; Catarina Bastos, Ana; van Groenigen, Jan Willem; Hungate, Bruce A.; Verheijen, Frank

    2017-05-01

    Applying biochar to soil is thought to have multiple benefits, from helping mitigate climate change [1, 2], to managing waste [3] to conserving soil [4]. Biochar is also widely assumed to boost crop yield [5, 6], but there is controversy regarding the extent and cause of any yield benefit [7]. Here we use a global-scale meta-analysis to show that biochar has, on average, no effect on crop yield in temperate latitudes, yet elicits a 25% average increase in yield in the tropics. In the tropics, biochar increased yield through liming and fertilization, consistent with the low soil pH, low fertility, and low fertilizer inputs typical of arable tropical soils. We also found that, in tropical soils, high-nutrient biochar inputs stimulated yield substantially more than low-nutrient biochar, further supporting the role of nutrient fertilization in the observed yield stimulation. In contrast, arable soils in temperate regions are moderate in pH, higher in fertility, and generally receive higher fertilizer inputs, leaving little room for additional benefits from biochar. Our findings demonstrate that the yield-stimulating effects of biochar are not universal, but may especially benefit agriculture in low-nutrient, acidic soils in the tropics. Biochar management in temperate zones should focus on potential non-yield benefits such as lime and fertilizer cost savings, greenhouse gas emissions control, and other ecosystem services.

  8. Frontiers in alley cropping: Transformative solutions for temperate agriculture.

    Science.gov (United States)

    Wolz, Kevin J; Lovell, Sarah T; Branham, Bruce E; Eddy, William C; Keeley, Keefe; Revord, Ronald S; Wander, Michelle M; Yang, Wendy H; DeLucia, Evan H

    2017-12-08

    Annual row crops dominate agriculture around the world and have considerable negative environmental impacts, including significant greenhouse gas emissions. Transformative land-use solutions are necessary to mitigate climate change and restore critical ecosystem services. Alley cropping (AC)-the integration of trees with crops-is an agroforestry practice that has been studied as a transformative, multifunctional land-use solution. In the temperate zone, AC has strong potential for climate change mitigation through direct emissions reductions and increases in land-use efficiency via overyielding compared to trees and crops grown separately. In addition, AC provides climate change adaptation potential and ecological benefits by buffering alley crops to weather extremes, diversifying income to hedge financial risk, increasing biodiversity, reducing soil erosion, and improving nutrient- and water-use efficiency. The scope of temperate AC research and application has been largely limited to simple systems that combine one timber tree species with an annual grain. We propose two frontiers in temperate AC that expand this scope and could transform its climate-related benefits: (i) diversification via woody polyculture and (ii) expanded use of tree crops for food and fodder. While AC is ready now for implementation on marginal lands, we discuss key considerations that could enhance the scalability of the two proposed frontiers and catalyze widespread adoption. © 2017 John Wiley & Sons Ltd.

  9. Analysis of growth trend changes for 51 temperate tree species using Korea national forest inventory data

    Science.gov (United States)

    Park, M.; Moon, M.; Park, J.; Cho, S.; Kim, H. S.

    2016-12-01

    Individual tree growth rates can be affected by various factors such as species, soil fertility, stand development stage, disturbance, and climate etc. To estimate the effect of changes in tree growth rate on the structure and functionality of forest ecosystem in the future, we analyzed the change of species-specific growth trends using the fifth Korea national forest inventory data, which was collected from 2006 to 2010. The ring samples of average tree were collected from nationwide inventory plots and the total number of individual tree ring series was 69,128 covering 185 tree species. Among those, fifty one species with more than 100 tree ring series were used for our analysis. For growth-trend analysis, standardized regional curves of individual species growth were generated from three forest zone in South Korea; subarctic, cool temperate, warm temperate forest zone. Then individual tree ring series was indexed by dividing the growth of the tree by expected growth from standardized regional curves. Then the ratio of all tree ring series were aligned by year and the Spearman's correlation coefficient of each species was calculated. The results show that most of species had increasing growth rates as forests developed after Korean war. For the last thirty years, 67.3% of species including Quercus spp. and Zelkova serrata had positive growth trends, on the other hand, 11.5% of species including Pinus spp. showed negative growth trends probably due to the changes in successional stages in Korean forests and climate change. These trends also vary with climate zone and species. For examples, Pinus densiflora, which showed negative growth trend overall, had steep negative growth trends in boreal and temperate zone, whereas it showed no specific trend in sub-tropical climate zone. Our trend analysis on 51 temperate tree species growth will be essential to predict the temperate forests species change for the this century.

  10. Employment and winter construction

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Larsen, Jacob Norvig

    2011-01-01

    hemisphere. Can climatic conditions alone explain the sizeable difference in reduction in building activity in the construction sector in European countries in the winter months, or are other factors such as technology, economic cycles and schemes for financial compensation influential as well? What...... of contracts for workers is more likely to explain differences in seasonal activity than climatic or technological factors....

  11. Global warming reduces plant reproductive output for temperate multi-inflorescence species on the Tibetan plateau.

    Science.gov (United States)

    Liu, Yinzhan; Mu, Junpeng; Niklas, Karl J; Li, Guoyong; Sun, Shucun

    2012-07-01

    • Temperature is projected to increase more during the winter than during the summer in cold regions. The effects of winter warming on reproductive effort have not been examined for temperate plant species. • Here, we report the results of experimentally induced seasonal winter warming (0.4 and 2.4°C increases in growing and nongrowing seasons, respectively, using warmed and ambient open-top chambers in a Tibetan Plateau alpine meadow) for nine indeterminate-growing species producing multiple (single-flowered or multi-flowered) inflorescences and three determinate-growing species producing single inflorescences after a 3-yr period of warming. • Warming reduced significantly flower number and seed production per plant for all nine multi-inflorescence species, but not for the three single-inflorescence species. Warming had an insignificant effect on the fruit to flower number ratio, seed size and seed number per fruit among species. The reduction in seed production was largely attributable to the decline in flower number per plant. The flowering onset time was unaffected for nine of the 12 species. Therefore, the decline in flower production and seed production in response to winter warming probably reflects a physiological response (e.g. metabolic changes associated with flower production). • Collectively, the data indicate that global warming may reduce flower and seed production for temperate herbaceous species and will probably have a differential effect on single- vs multi-inflorescence species. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  12. A selective integrated tempering method.

    Science.gov (United States)

    Yang, Lijiang; Qin Gao, Yi

    2009-12-07

    In this paper, based on the integrated tempering sampling we introduce a selective integrated tempering sampling (SITS) method for the efficient conformation sampling and thermodynamics calculations for a subsystem in a large one, such as biomolecules solvated in aqueous solutions. By introducing a potential surface scaled with temperature, the sampling over the configuration space of interest (e.g., the solvated biomolecule) is selectively enhanced but the rest of the system (e.g., the solvent) stays largely unperturbed. The applications of this method to biomolecular systems allow highly efficient sampling over both energy and configuration spaces of interest. Comparing to the popular and powerful replica exchange molecular dynamics (REMD), the method presented in this paper is significantly more efficient in yielding relevant thermodynamics quantities (such as the potential of mean force for biomolecular conformational changes in aqueous solutions). It is more important that SITS but not REMD yielded results that are consistent with the traditional umbrella sampling free energy calculations when explicit solvent model is used since SITS avoids the sampling of the irrelevant phase space (such as the boiling water at high temperatures).

  13. Frost stress evolution and winter pea ideotype in the context of climate warming at a regional scale

    OpenAIRE

    Castel Thierry; Lecomte Christophe; Richard Yves; Lejeune-Hénaut Isabelle; Larmure Annabelle

    2017-01-01

    Pea (Pisum sativum L.) is an important crop in temperate regions for its high seed protein concentration that is particularly sensitive to abiotic stresses. The abrupt temperature increase known as the “1987/1988 temperature regime shift” that occurs over Europe is questioning how winter pea will perform in the changing climate. This study assessed the winter frost damage evolution along from 1961 to 2015 in Burgundy-Franche-Comté by using: (1) daily observed and gridded regional temperature ...

  14. Mapping Forest Fire Susceptibility in Temperate Mountain Areas with Expert Knowledge. A Case Study from Iezer Mountains, Romanian Carpathians

    Science.gov (United States)

    Mihai, Bogdan; Savulescu, Ionut

    2014-05-01

    Forest fires in Romanian Carpathians became a frequent phenomenon during the last decade, although local climate and other environmental features did not create typical conditions. From 2004, forest fires affect in Romania more than 100 hectares/year of different forest types (deciduous and coniferous). Their magnitude and frequency are not known, since a historical forest fire inventory does not exist (only press papers and local witness for some selected events). Forest fires features the summer dry periods but there are dry autumns and early winter periods with events of different magnitudes. The application we propose is based on an empirical modeling of forest fire susceptibility in a typical mountain area from the Southern Carpathians, the Iezer Mountains (2462 m). The study area features almost all the altitudinal vegetation zones of the European temperate mountains, from the beech zone, to the coniferous zone, the subalpine and the alpine zones (Mihai et al., 2007). The analysis combines GIS and remote sensing models (Chuvieco et al., 2012), starting from the ideas that forest fires are featured by the ignition zones and then by the fire propagation zones. The first data layer (ignition zones) is the result of the crossing between the ignition factors: lightning - points of multitemporal occurence and anthropogenic activities (grazing, tourism and traffic) and the ignition zones (forest fuel zonation - forest stands, soil cover and topoclimatic factor zonation). This data is modelled from different sources: the MODIS imagery fire product (Hantson et al., 2012), detailed topographic maps, multitemporal orthophotos at 0.5 m resolution, Landsat multispectral imagery, forestry cadastre maps, detailed soil maps, meteorological data (the WorldClim digital database) as well as the field survey (mapping using GPS and local observation). The second data layer (fire propagation zones) is the result of the crossing between the forest fuel zonation, obtained with the

  15. Temper Fragileness Study for RUL 2 Steel

    Directory of Open Access Journals (Sweden)

    Rodica Rădulea

    2007-10-01

    Full Text Available This paper presents an experimental study about the tenacity variation depending on the tempering temperature of the steel RUL2 grade, within q wide range of temperatures. By this analysis it is possible to study the cooling of the above mentioned heat treatment on the temper fragileness.

  16. Solar Radiation Determines Site Occupancy of Coexisting Tropical and Temperate Deer Species Introduced to New Zealand Forests.

    Directory of Open Access Journals (Sweden)

    Robert B Allen

    Full Text Available Assemblages of introduced taxa provide an opportunity to understand how abiotic and biotic factors shape habitat use by coexisting species. We tested hypotheses about habitat selection by two deer species recently introduced to New Zealand's temperate rainforests. We hypothesised that, due to different thermoregulatory abilities, rusa deer (Cervus timorensis; a tropical species would prefer warmer locations in winter than red deer (Cervus elaphus scoticus; a temperate species. Since adult male rusa deer are aggressive in winter (the rut, we also hypothesised that rusa deer and red deer would not use the same winter locations. Finally, we hypothesised that in summer both species would prefer locations with fertile soils that supported more plant species preferred as food. We used a 250 × 250 m grid of 25 remote cameras to collect images in a 100-ha montane study area over two winters and summers. Plant composition, solar radiation, and soil fertility were also determined for each camera location. Multiseason occupancy models revealed that direct solar radiation was the best predictor of occupancy and detection probabilities for rusa deer in winter. Multistate, multiseason occupancy models provided strong evidence that the detection probability of adult male rusa deer was greater in winter and when other rusa deer were present at a location. Red deer mostly vacated the study area in winter. For the one season that had sufficient camera images of both species (summer 2011 to allow two-species occupancy models to be fitted, the detection probability of rusa deer also increased with solar radiation. Detection probability also varied with plant composition for both deer species. We conclude that habitat use by coexisting tropical and temperate deer species in New Zealand likely depends on the interplay between the thermoregulatory and behavioural traits of the deer and the abiotic and biotic features of the habitat.

  17. Parallel tempering for the traveling salesman problem

    Energy Technology Data Exchange (ETDEWEB)

    Percus, Allon [Los Alamos National Laboratory; Wang, Richard [UCLA MATH DEPT; Hyman, Jeffrey [UCLA MATH DEPT; Caflisch, Russel [UCLA MATH DEPT

    2008-01-01

    We explore the potential of parallel tempering as a combinatorial optimization method, applying it to the traveling salesman problem. We compare simulation results of parallel tempering with a benchmark implementation of simulated annealing, and study how different choices of parameters affect the relative performance of the two methods. We find that a straightforward implementation of parallel tempering can outperform simulated annealing in several crucial respects. When parameters are chosen appropriately, both methods yield close approximation to the actual minimum distance for an instance with 200 nodes. However, parallel tempering yields more consistently accurate results when a series of independent simulations are performed. Our results suggest that parallel tempering might offer a simple but powerful alternative to simulated annealing for combinatorial optimization problems.

  18. Safety Zones

    Science.gov (United States)

    These are established primarily to reduce the accidental spread of hazardous substances by workers or equipment from contaminated areas to clean areas. They include the exclusion (hot) zone, contamination reduction (warm) zone, and support (cold) zone.

  19. Adaptation to seasonality and the winter freeze

    Directory of Open Access Journals (Sweden)

    Jill Christine Preston

    2013-06-01

    Full Text Available Flowering plants initially diversified during the Mesozoic era at least 140 million years ago in regions of the world where temperate seasonal environments were not encountered. Since then several cooling events resulted in the contraction of warm and wet environments and the establishment of novel temperate zones in both hemispheres. In response, less than half of modern angiosperm families have members that evolved specific adaptations to cold seasonal climates, including cold acclimation, freezing tolerance, endodormancy, and vernalization responsiveness. Despite compelling evidence for multiple independent origins, the level of genetic constraint on the evolution of adaptations to seasonal cold is not well understood. However, the recent increase in molecular genetic studies examining the response of model and crop species to seasonal cold offers new insight into the evolutionary lability of these traits. This insight has major implications for our understanding of complex trait evolution, and the potential role of local adaptation in response to past and future climate change. In this review, we discuss the biochemical, morphological, and developmental basis of adaptations to seasonal cold, and synthesize recent literature on the genetic basis of these traits in a phylogenomic context. We find evidence for multiple genetic links between distinct physiological responses to cold, possibly reinforcing the coordinated expression of these traits. Furthermore, repeated recruitment of the same or similar ancestral pathways suggests that land plants might be somewhat pre-adapted to dealing with temperature stress, perhaps making inducible cold traits relatively easy to evolve.

  20. Adaptation to seasonality and the winter freeze.

    Science.gov (United States)

    Preston, Jill C; Sandve, Simen R

    2013-01-01

    Flowering plants initially diversified during the Mesozoic era at least 140 million years ago in regions of the world where temperate seasonal environments were not encountered. Since then several cooling events resulted in the contraction of warm and wet environments and the establishment of novel temperate zones in both hemispheres. In response, less than half of modern angiosperm families have members that evolved specific adaptations to cold seasonal climates, including cold acclimation, freezing tolerance, endodormancy, and vernalization responsiveness. Despite compelling evidence for multiple independent origins, the level of genetic constraint on the evolution of adaptations to seasonal cold is not well understood. However, the recent increase in molecular genetic studies examining the response of model and crop species to seasonal cold offers new insight into the evolutionary lability of these traits. This insight has major implications for our understanding of complex trait evolution, and the potential role of local adaptation in response to past and future climate change. In this review, we discuss the biochemical, morphological, and developmental basis of adaptations to seasonal cold, and synthesize recent literature on the genetic basis of these traits in a phylogenomic context. We find evidence for multiple genetic links between distinct physiological responses to cold, possibly reinforcing the coordinated expression of these traits. Furthermore, repeated recruitment of the same or similar ancestral pathways suggests that land plants might be somewhat pre-adapted to dealing with temperature stress, perhaps making inducible cold traits relatively easy to evolve.

  1. Generalized provisional seed zones for native plants

    Science.gov (United States)

    Andrew D. Bower; J. Bradley St.Clair; Vicky. Erickson

    2014-01-01

    Deploying well-adapted and ecologically appropriate plant materials is a core component of successful restoration projects. We have developed generalized provisional seed zones that can be applied to any plant species in the United States to help guide seed movement. These seed zones are based on the intersection of high-resolution climatic data for winter minimum...

  2. Editorial - The winter Atomiades

    CERN Multimedia

    Staff Association

    2011-01-01

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

  3. Winter in Bavaria

    Directory of Open Access Journals (Sweden)

    Anthony Stephens

    2004-08-01

    Full Text Available "A Winter In Bavaria" was written on location in Regensburg, Germany, and is the first-hand account of a cataclysm, already predicted by Nostradamus, which changed the direction of Bavarian culture forever. Anything vaguely resembling an allusion to any real person or institution is entirely coincidental, has no foundation in fact and is clearly the product of a mind estranged - except that Bavarian beer is, by and large, still to be highly recommended.

  4. Net ecosystem carbon exchange of a dry temperate eucalypt forest

    Science.gov (United States)

    Hinko-Najera, Nina; Isaac, Peter; Beringer, Jason; van Gorsel, Eva; Ewenz, Cacilia; McHugh, Ian; Exbrayat, Jean-François; Livesley, Stephen J.; Arndt, Stefan K.

    2017-08-01

    Forest ecosystems play a crucial role in the global carbon cycle by sequestering a considerable fraction of anthropogenic CO2, thereby contributing to climate change mitigation. However, there is a gap in our understanding about the carbon dynamics of eucalypt (broadleaf evergreen) forests in temperate climates, which might differ from temperate evergreen coniferous or deciduous broadleaved forests given their fundamental differences in physiology, phenology and growth dynamics. To address this gap we undertook a 3-year study (2010-2012) of eddy covariance measurements in a dry temperate eucalypt forest in southeastern Australia. We determined the annual net carbon balance and investigated the temporal (seasonal and inter-annual) variability in and environmental controls of net ecosystem carbon exchange (NEE), gross primary productivity (GPP) and ecosystem respiration (ER). The forest was a large and constant carbon sink throughout the study period, even in winter, with an overall mean NEE of -1234 ± 109 (SE) g C m-2 yr-1. Estimated annual ER was similar for 2010 and 2011 but decreased in 2012 ranging from 1603 to 1346 g C m-2 yr-1, whereas GPP showed no significant inter-annual variability, with a mean annual estimate of 2728 ± 39 g C m-2 yr-1. All ecosystem carbon fluxes had a pronounced seasonality, with GPP being greatest during spring and summer and ER being highest during summer, whereas peaks in NEE occurred in early spring and again in summer. High NEE in spring was likely caused by a delayed increase in ER due to low temperatures. A strong seasonal pattern in environmental controls of daytime and night-time NEE was revealed. Daytime NEE was equally explained by incoming solar radiation and air temperature, whereas air temperature was the main environmental driver of night-time NEE. The forest experienced unusual above-average annual rainfall during the first 2 years of this 3-year period so that soil water content remained relatively high and the forest

  5. Net ecosystem carbon exchange of a dry temperate eucalypt forest

    Directory of Open Access Journals (Sweden)

    N. Hinko-Najera

    2017-08-01

    Full Text Available Forest ecosystems play a crucial role in the global carbon cycle by sequestering a considerable fraction of anthropogenic CO2, thereby contributing to climate change mitigation. However, there is a gap in our understanding about the carbon dynamics of eucalypt (broadleaf evergreen forests in temperate climates, which might differ from temperate evergreen coniferous or deciduous broadleaved forests given their fundamental differences in physiology, phenology and growth dynamics. To address this gap we undertook a 3-year study (2010–2012 of eddy covariance measurements in a dry temperate eucalypt forest in southeastern Australia. We determined the annual net carbon balance and investigated the temporal (seasonal and inter-annual variability in and environmental controls of net ecosystem carbon exchange (NEE, gross primary productivity (GPP and ecosystem respiration (ER. The forest was a large and constant carbon sink throughout the study period, even in winter, with an overall mean NEE of −1234 ± 109 (SE g C m−2 yr−1. Estimated annual ER was similar for 2010 and 2011 but decreased in 2012 ranging from 1603 to 1346 g C m−2 yr−1, whereas GPP showed no significant inter-annual variability, with a mean annual estimate of 2728 ± 39 g C m−2 yr−1. All ecosystem carbon fluxes had a pronounced seasonality, with GPP being greatest during spring and summer and ER being highest during summer, whereas peaks in NEE occurred in early spring and again in summer. High NEE in spring was likely caused by a delayed increase in ER due to low temperatures. A strong seasonal pattern in environmental controls of daytime and night-time NEE was revealed. Daytime NEE was equally explained by incoming solar radiation and air temperature, whereas air temperature was the main environmental driver of night-time NEE. The forest experienced unusual above-average annual rainfall during the first 2 years of this 3-year period so

  6. Vertical distribution of mesozooplankton in the central and eastern Arabian Sea during the winter monsoons

    Digital Repository Service at National Institute of Oceanography (India)

    Padmavati, G.; Haridas, P.; Nair, K.K.C.; Gopalakrishnan, T.C.; Shiney, P.; Madhupratap, M.

    The vertical distribution of mesozooplankton in the central and eastern Arabian Sea was investigated during the winter monsoon in 1995. Samples were analysed from discrete depth zones defined according to oxygen and temperature profiles of the water...

  7. The interaction between freezing tolerance and phenology in temperate deciduous trees

    Directory of Open Access Journals (Sweden)

    Yann eVitasse

    2014-10-01

    Full Text Available Temperate climates are defined by a distinct temperature seasonality with large and often unpredictable weather during any of the four seasons. To thrive in such climates, trees have to withstand a cold winter and the stochastic occurrence of freeze events during any time of the year. The physiological mechanisms trees adopt to escape, avoid and tolerate freezing temperatures include a cold acclimation in autumn, a dormancy period during winter (leafless in deciduous trees, and the maintenance of a certain freezing tolerance during dehardening in early spring. The change from one phase to the next is mediated by complex interactions between temperature and photoperiod. This review aims at providing an overview of the interplay between phenology of leaves and species-specific freezing resistance. First, we address the long-term evolutionary responses that enabled temperate trees to tolerate certain low temperature extremes. We provide evidence that short term acclimation of freezing resistance plays a crucial role both in dormant and active buds, including re-acclimation to cold conditions following warm spells. This ability declines to almost zero during leaf emergence. Second, we show that the risk that native temperate trees encounter freeze injuries is low and is confined to spring and underline that this risk might be altered by climate warming depending on species-specific phenological responses to environmental cues.

  8. Appropriate welding conditions of temper bead weld repair for SQV2A pressure vessel steel

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, R.; Matsuda, F. [NDE Center, Japan Power Engineering and Inspection Corp. (Japan); Brziak, P. [Welding Research Inst. - Industrial Inst. of Slovak Republic (Slovakia); Lomozik, M. [Inst. of Welding (Poland)

    2004-07-01

    Temper bead welding technique is one of the most important repair welding methods for large structures for which it is difficult to perform the specified post weld heat treatment. In this study, appropriate temper bead welding conditions to improve the characteristics of heat affected zone (HAZ) are studied using pressure vessel steel SQV2A corresponding to ASTM A533 Type B Class 1. Thermal/mechanical simulator is employed to give specimens welding thermal cycles from single to quadruple cycle. Charpy absorbed energy and hardness of simulated CGHAZ by first cycle were degraded as compared with base metal. Improvability of these degradations by subsequent cycles is discussed and appropriate temper bead thermal cycles are clarified. When the peak temperature lower than Ac1 and near Ac1 in the second thermal cycle is applied to CGAHZ by first thermal cycle, the characteristics of CGHAZ improve enough. When the other peak temperatures (that is, higher than Ac1) in the second thermal cycle are applied to the CGHAZ, third or more thermal cycle temper bead process should be applied to improve the properties. Appropriate weld condition ranges are selected based on the above results. The validity of the selected ranges is verified by the temper bead welding test. (orig.)

  9. Genetic analysis of bolting after winter in sugar beet (Beta vulgaris L.).

    Science.gov (United States)

    Pfeiffer, Nina; Tränkner, Conny; Lemnian, Ioana; Grosse, Ivo; Müller, Andreas E; Jung, Christian; Kopisch-Obuch, Friedrich J

    2014-11-01

    This study reveals for the first time a major QTL for post-winter bolting resistance in sugar beet ( Beta vulgaris L.). The knowledge of this QTL is a major contribution towards the development of a winter sugar beet with controlled bolting behavior. In cool temperate climates, sugar beets are currently grown as a spring crop. They are sown in spring and harvested in autumn. Growing sugar beet as a winter crop with an extended vegetation period fails due to bolting after winter. Bolting after winter might be controlled by accumulating genes for post-winter bolting resistance. Previously, we had observed in field experiments a low post-winter bolting rate of 0.5 for sugar beet accession BETA 1773. This accession was crossed with a biennial sugar beet with regular bolting behavior to develop a F3 mapping population. The population was grown in the greenhouse, exposed to artificial cold treatment for 16 weeks and transplanted to the field. Bolting was recorded twice a week from May until October. Post-winter bolting behavior was assessed by two different factors, bolting delay (determined as days to bolt after cold treatment) and post-winter bolting resistance (bolting rate after winter). For days to bolt, means of F3 families ranged from 25 to 164 days while for bolting rate F3 families ranged from 0 to 1. For each factor one QTL explaining about 65% of the phenotypic variation was mapped to the same region on linkage group 9 with a partially recessive allele increasing bolting delay and post-winter bolting resistance. The results are discussed in relation to the potential use of marker-assisted breeding of winter sugar beets with controlled bolting.

  10. Unexpected winter phytoplankton blooms in the North Atlantic subpolar gyre

    Science.gov (United States)

    Lacour, L.; Ardyna, M.; Stec, K. F.; Claustre, H.; Prieur, L.; Poteau, A.; D'Alcala, M. Ribera; Iudicone, D.

    2017-11-01

    In mid- and high-latitude oceans, winter surface cooling and strong winds drive turbulent mixing that carries phytoplankton to depths of several hundred metres, well below the sunlit layer. This downward mixing, in combination with low solar radiation, drastically limits phytoplankton growth during the winter, especially that of the diatoms and other species that are involved in seeding the spring bloom. Here we present observational evidence for widespread winter phytoplankton blooms in a large part of the North Atlantic subpolar gyre from autonomous profiling floats equipped with biogeochemical sensors. These blooms were triggered by intermittent restratification of the mixed layer when mixed-layer eddies led to a horizontal transport of lighter water over denser layers. Combining a bio-optical index with complementary chemotaxonomic and modelling approaches, we show that these restratification events increase phytoplankton residence time in the sunlight zone, resulting in greater light interception and the emergence of winter blooms. Restratification also caused a phytoplankton community shift from pico- and nanophytoplankton to phototrophic diatoms. We conclude that transient winter blooms can maintain active diatom populations throughout the winter months, directly seeding the spring bloom and potentially making a significant contribution to over-winter carbon export.

  11. The Effect of Tempering on Strength Properties and Seed Coat ...

    African Journals Online (AJOL)

    ... tempering on seed coat adhesion strength and mechanical strength of sorghum and millet grain kernels was investigated at different tempering durations. Tempering reduced the kernel breaking strength and had significant effect on seed coat adhesion strength. Tempering the grain for 60 minutes at ambient temperature ...

  12. [Suitability evaluation of great bustard (Otis tarda)'s wintering habitat in Baiyangdian basin].

    Science.gov (United States)

    Zhao, Zhi-xuan; Yan, Deng-hua; Weng, Bai-sha; Zhang, Biao

    2011-07-01

    Based on the related researches of great bustard's wintering habitat selection as well as the advices of related experts and the distribution records of great bustard in Baiyangdian basin, 3 first class indices and 13 second indices were chosen to characterize the key factors affecting the wintering habitat selection of great bustard, and a habitat quality evaluation model was built to assess the quality of wintering habitat selection of great bustard in Baiyangdian basin. In 2005, the suitable wintering habitats of great bustard in the basin had an area of 11907.25 km2, accounting for 34.1% of the total. Of the suitable wintering habitats, the most suitable habitats had an area of 4596.25 km2, only 13.2% of the total and comparatively concentrated in two zones, i.e., Baiyangdian Wetland Natural Reserve and its peripheral area (zone I) in the east of Baiyangdian basin, and Xingtang and Quyang counties (zone II) in the southwest of Baiyangdian basin. The total area of the most suitable habitats in zone I and zone II was 2803.55 km2, accounting for 61.0% of the most suitable habitats in the basin. To protect the wintering habitat of great bustard in the basin, proper measures should be taken according to the environmental features of the two zones.

  13. Comparisons of invasive plants in southern Africa originating from southern temperate, northern temperate and tropical regions

    Directory of Open Access Journals (Sweden)

    L. Henderson

    2006-08-01

    Full Text Available A subset of invasive alien plant species in southern Africa was analysed in terms of their history of introduction, rate of spread, countries/region of origin, taxonomy, growth forms, cultivated uses, weed status and current distribution in southern Africa, and comparisons made of those originating from south of the tropic of Capricorn, north of the tropic of Cancer and from the tropics. The subset of 233 species, belonging to 58 families, includes all important declared species and some potentially important species. Almost as many species originate from temperate regions (112 as from the tropics (121. Most southern temperate species came from Australia (28/36, most tropical species from tropical America (92/121 and most northern temperate species from Europe (including the Mediterranean and Asia (58/76. Transformers account for 33% of  all species. More transformers are of tropical origin (36 than of northern temperate (24 and southern temperate origin (18. However. 50% of southern temperate species are transformers, compared to 32% of northern temperate and 29% of tropical species. Southern temperate transformer species are mainly woody trees and shrubs that were established on a grand scale as silvicultural crops, barriers (hedges, windbreaks and screens and cover/binders. Most aquatics, herbs, climbers and succulent shrubs an. trom the tropics. Ornamentals are the single largest category of plants from all three regions, the tropics having contributed twice as many species as temperate regions.

  14. Comparisons of invasive plants in southern Africa originating from southern temperate, northern temperate and tropical regions

    Directory of Open Access Journals (Sweden)

    L. Henderson

    2006-12-01

    Full Text Available A subset of invasive alien plant species in southern Africa was analysed in terms of their history of introduction, rate of spread, countries/region of origin, taxonomy, growth forms, cultivated uses, weed status and current distribution in southern Africa, and comparisons made of those originating from south of the tropic of Capricorn, north of the tropic of Cancer and from the tropics. The subset of 233 species, belonging to 58 families, includes all important declared species and some potentially important species. Almost as many species originate from temperate regions (112 as from the tropics (121. Most southern temperate species came from Australia (28/36, most tropical species from tropical America (92/121 and most northern temperate species from Europe (including the Mediterranean and Asia (58/76. Transformers account for 33% of  all species. More transformers are of tropical origin (36 than of northern temperate (24 and southern temperate origin (18. However. 50% of southern temperate species are transformers, compared to 32% of northern temperate and 29% of tropical species. Southern temperate transformer species are mainly woody trees and shrubs that were established on a grand scale as silvicultural crops, barriers (hedges, windbreaks and screens and cover/binders. Most aquatics, herbs, climbers and succulent shrubs an. trom the tropics. Ornamentals are the single largest category of plants from all three regions, the tropics having contributed twice as many species as temperate regions.

  15. Disturbance to wintering western snowy plovers

    Science.gov (United States)

    Lafferty, Kevin D.

    2001-01-01

    In order to better understand the nature of disturbances to wintering snowy plovers, I observed snowy plovers and activities that might disturb them at a beach near Devereux Slough in Santa Barbara, California, USA. Disturbance (activity that caused plovers to move or fly) to wintering populations of threatened western snowy plovers was 16 times higher at a public beach than at protected beaches. Wintering plovers reacted to disturbance at half the distance (∼40 m) as has been reported for breeding snowy plovers (∼80 m). Humans, dogs, crows and other birds were the main sources of disturbance on the public beach, and each snowy plover was disturbed, on average, once every 27 weekend min and once every 43 weekday min. Dogs off leash were a disproportionate source of disturbance. Plovers were more likely to fly from dogs, horses and crows than from humans and other shorebirds. Plovers were less abundant near trail heads. Over short time scales, plovers did not acclimate to or successfully find refuge from disturbance. Feeding rates declined with increased human activity. I used data from these observations to parameterize a model that predicted rates of disturbance given various management actions. The model found that prohibiting dogs and a 30 m buffer zone surrounding a 400 m stretch of beach provided the most protection for plovers for the least amount of impact to beach recreation.

  16. Winter School Les Houches

    CERN Document Server

    Lannoo, Michel; Bastard, Gérald; Voos, Michel; Boccara, Nino

    1986-01-01

    The Winter School held in Les Houches on March 12-21, 1985 was devoted to Semiconductor Heterojunctions and Superlattices, a topic which is recognized as being now one of the most interesting and active fields in semiconductor physics. In fact, following the pioneering work of Esaki and Tsu in 1970, the study of these two-dimensional semiconductor heterostructures has developed rapidly, both from the point of view of basic physics and of applications. For instance, modulation-doped heterojunctions are nowadays currently used to investigate the quantum Hall effect and to make very fast transistors. This book contains the lectures presented at this Winter School, showing in particular that many aspects of semiconductor heterojunctions and super­ lattices were treated, extending from the fabrication of these two-dimensional systems to their basic properties and applications in micro-and opto-electron­ ics. Among the subjects which were covered, one can quote as examples: molecular beam epitaxy and metallorgani...

  17. Comparison of sampling efficiency between simulated tempering and replica exchange

    OpenAIRE

    Zhang, Cheng; Ma, Jianpeng

    2008-01-01

    We compared the sampling efficiency of simulated tempering and replica exchange. Our results indicate that simulated tempering is superior to replica exchange if the parameters for temperature transition in simulated tempering are adjusted to be proportional to the partition function. It is shown that, in simulated tempering, the rate of traversing energy space of different temperatures is much higher than that in replica exchange, especially in the case of low tempering frequency and∕or larg...

  18. Comparison of sampling efficiency between simulated tempering and replica exchange.

    Science.gov (United States)

    Zhang, Cheng; Ma, Jianpeng

    2008-10-07

    We compared the sampling efficiency of simulated tempering and replica exchange. Our results indicate that simulated tempering is superior to replica exchange if the parameters for temperature transition in simulated tempering are adjusted to be proportional to the partition function. It is shown that, in simulated tempering, the rate of traversing energy space of different temperatures is much higher than that in replica exchange, especially in the case of low tempering frequency and/or larger temperature separations.

  19. Sub-zero cold tolerance of Spartina pectinata (prairie cordgrass) and Miscanthus ? giganteus: candidate bioenergy crops for cool temperate climates

    OpenAIRE

    Friesen, Patrick C.; Peixoto, Murilo de Melo; Lee, D. K.; Sage, Rowan F.

    2015-01-01

    Miscanthus ? giganteus grown in cool temperate regions of North America and Europe can exhibit severe mortality in the year after planting, and poor frost tolerance of leaves. Spartina pectinata (prairie cordgrass), a productive C4 perennial grass native to North America, has been suggested as an alternative biofuel feedstock for colder regions; however, its cold tolerance relative to M. ? giganteus is uncertain. Here, we compare the cold tolerance thresholds for winter-dormant rhizomes and s...

  20. Impacts of cloud immersion on microclimate, photosynthesis and water relations of fraser fir in a temperate mountain cloud forest

    Science.gov (United States)

    Keith Reinhardt; William K. Smith

    2010-01-01

    The red spruce-Fraser fir ecosystem (Picea rubens Sarg.-Abies fraseri [Pursh] Poir.) of the southern Appalachian mountains is a temperate zone cloud forest immersed in clouds for 30 to 40 percent of a typical summer day, and experiencing immersion on about 65 percent of all days annually. We compared the microclimate,...

  1. The role of seasonal flowering responses in adaptation of grasses to temperate climates.

    OpenAIRE

    Siri eFjellheim; Scott eBoden; Ben eTrevaskis

    2014-01-01

    Grasses of the subfamily Pooideae, which includes important cereal crops and pasture grasses, are widespread in temperate zones. Seasonal regulation of developmental transitions coordinates the life cycles of Pooideae with the passing seasons, so that flowering and seed production coincide with favourable conditions in spring. This review examines the molecular pathways that control the seasonal flowering responses of Pooideae and how variation in the activity of genes controlling these pathw...

  2. Measurements for winter road maintenance

    OpenAIRE

    Riehm, Mats

    2012-01-01

    Winter road maintenance activities are crucial for maintaining the accessibility and traffic safety of the road network at northerly latitudes during winter. Common winter road maintenance activities include snow ploughing and the use of anti-icing agents (e.g. road salt, NaCl). Since the local weather is decisive in creating an increased risk of slippery conditions, understanding the link between local weather and conditions at the road surface is critically important. Sensors are commonly i...

  3. Stamena winter wheat variety

    Directory of Open Access Journals (Sweden)

    Mišić Todor

    2001-01-01

    Full Text Available Stamena is a winter wheat variety developed at the Institute of Field and Vegetable Crops in Novi Sad, Yugoslavia. It was released by the Federal Commission for varietals Approval in 1999. Stamena was developed by crossing genetically divergent and highly productive parents Lasta and Rodna (Breeders: T. Mišić. N. Mladenov, Z. Jerković and R. Jevtić. Spike is white, smooth, awn less, medium compact with 18-21 spike lets. The grain is vitreous and dark red (Triticum aestivum L. ssp. vulgar e var. lutescens. Stamena is a medium early variety, 1 day earlier than Partizanka and 3 days earlier than Jugoslavija (Table 4. It has excellent resistance to winterkilling, as in very winter hardy Partizanka. The average stem height is 78 cm, with a good resistance to lodging. Stamena has field resistance to leaf rust (Pucce, recondita tritict, horizontal resistance, which is the type of resistance that modern wheat breeding is interested in. The resistance to stem rust (Pucce, graminis tritict is good and to powdery mildew (Erysiphegraminis tritici very good. The 1000 grain mass is about 32 g and volume grain mass 81.3 kg/hi. (Table 2. Stamena is classified in the subgroup A-l. It has excellent milling and baking quality and it belong to the 1st technological group (quality enhancer. The quantity of dry gluten is about 9%. The variety Stamena is a very productive, with the genetic potential for grain above 11 t/ha suitable for growing on fertile and less fertile soils. It has started to be grown commercially in 2000.

  4. Plasmodium vivax populations revisited: mitochondrial genomes of temperate strains in Asia suggest ancient population expansion

    Directory of Open Access Journals (Sweden)

    Miao Miao

    2012-02-01

    Full Text Available Abstract Background Plasmodium vivax is the most widely distributed human malaria parasite outside of Africa, and its range extends well into the temperate zones. Previous studies provided evidence for vivax population differentiation, but temperate vivax parasites were not well represented in these analyses. Here we address this deficit by using complete mitochondrial (mt genome sequences to elucidate the broad genetic diversity and population structure of P. vivax from temperate regions in East and Southeast Asia. Results From the complete mtDNA sequences of 99 clinical samples collected in China, Myanmar and Korea, a total of 30 different haplotypes were identified from 26 polymorphic sites. Significant differentiation between different East and Southeast Asian parasite populations was observed except for the comparison between populations from Korea and southern China. Haplotype patterns and structure diversity analysis showed coexistence of two different groups in East Asia, which were genetically related to the Southeast Asian population and Myanmar population, respectively. The demographic history of P. vivax, examined using neutrality tests and mismatch distribution analyses, revealed population expansion events across the entire P. vivax range and the Myanmar population. Bayesian skyline analysis further supported the occurrence of ancient P. vivax population expansion. Conclusions This study provided further resolution of the population structure and evolution of P. vivax, especially in temperate/warm-temperate endemic areas of Asia. The results revealed divergence of the P. vivax populations in temperate regions of China and Korea from other populations. Multiple analyses confirmed ancient population expansion of this parasite. The extensive genetic diversity of the P. vivax populations is consistent with phenotypic plasticity of the parasites, which has implications for malaria control.

  5. Optimal Cross Hedging Winter Canola

    OpenAIRE

    Kim, Seon-Woong; Brorsen, B. Wade; Yoon, Byung-Sam

    2014-01-01

    Winter canola in the southern Great Plains has shown large price fluctuations and there have been questions about which futures market could be used to reduce price risk. Our results indicate that the optimal futures contract to cross hedge winter canola is soybean oil futures.

  6. Autodeformation of Carburized Steel during Tempering

    Directory of Open Access Journals (Sweden)

    Regita BENDIKIENĖ

    2013-03-01

    Full Text Available The article analyses the results of autodeformation registered during tempering of carburized steel. Test pieces for the tests were carburized till the different depth in order to examine influence of depth of carburization on the deformation of steel during heat treatment operation. Carburization was performed on the one surface of test pieces seeking to analyze extent of acted normal stresses to autodeformation of steel. Different bending loads were applied for analyzed steel from 5 MPa to 100 MPa. Deflection of test pieces was analyzed. The obtained results proved that size and direction of deflection were affected by depth of carburization. Particular results of stretched and compressed surface examination showed different behavior of test pieces during tempering process. Test pieces, which undergo deformation at the beginning of martensitic transformation, after unloading bend further. When tempered test pieces with assimetrically carburized layer bend during hardening, its direction and extent of autodeformation depend on depth of carburization and tempering temperature. Kinetics of autodeformation (during tempering is affected by difference of volume changes in the carburized part and in the unaffected low carbon part of specimen, and similarly by decomposition of retained austenite in the carburized part.DOI: http://dx.doi.org/10.5755/j01.ms.19.1.3820

  7. First Temperate Exoplanet Sized Up

    Science.gov (United States)

    2010-03-01

    Combining observations from the CoRoT satellite and the ESO HARPS instrument, astronomers have discovered the first "normal" exoplanet that can be studied in great detail. Designated Corot-9b, the planet regularly passes in front of a star similar to the Sun located 1500 light-years away from Earth towards the constellation of Serpens (the Snake). "This is a normal, temperate exoplanet just like dozens we already know, but this is the first whose properties we can study in depth," says Claire Moutou, who is part of the international team of 60 astronomers that made the discovery. "It is bound to become a Rosetta stone in exoplanet research." "Corot-9b is the first exoplanet that really does resemble planets in our solar system," adds lead author Hans Deeg. "It has the size of Jupiter and an orbit similar to that of Mercury." "Like our own giant planets, Jupiter and Saturn, the planet is mostly made of hydrogen and helium," says team member Tristan Guillot, "and it may contain up to 20 Earth masses of other elements, including water and rock at high temperatures and pressures." Corot-9b passes in front of its host star every 95 days, as seen from Earth [1]. This "transit" lasts for about 8 hours, and provides astronomers with much additional information on the planet. This is fortunate as the gas giant shares many features with the majority of exoplanets discovered so far [2]. "Our analysis has provided more information on Corot-9b than for other exoplanets of the same type," says co-author Didier Queloz. "It may open up a new field of research to understand the atmospheres of moderate- and low-temperature planets, and in particular a completely new window in our understanding of low-temperature chemistry." More than 400 exoplanets have been discovered so far, 70 of them through the transit method. Corot-9b is special in that its distance from its host star is about ten times larger than that of any planet previously discovered by this method. And unlike all such

  8. Relating Leaf Nitrogen, Leaf Photosynthesis and Canopy CO2 Exchange in a Temperate Winter Barley Field

    Science.gov (United States)

    Jensen, R.; Boegh, E.; Herbst, M.; Friborg, T.

    2012-12-01

    Net exchange of CO2 between the atmosphere and the soil-vegetation interface (NEE) is controlled by a wide range of biochemical and biophysical processes where leaf photosynthesis is often the most important. In mechanistically and physically based photosynthesis models (e.g. Farquhar et al. 1980) leaf nutrient status is a limiting factor for the photosynthetic capacity since it is implicitly incorporated through the parameters of maximum rate of carboxylation of CO2 (Vcmax) and the maximum rate of electron transport (Jmax). These are closely related to leaf nitrogen concentration (Na) and leaf chlorophyll content (Cab) and often show a characteristic seasonal dynamic. When simulating CO2 exchange, model outputs are sensitive to leaf photosynthetic capacity, which is labour consuming to verify through field measurements. A less time consuming method is to measure leaf "greenness" (SPAD), which is closely related to chlorophyll content and thus photosynthetic capacity. In the present study field measurements of leaf photosynthesis (LI-6400, LICOR Inc.), leaf reflectance (SPAD-502, Minolta), and LAI (LAI-2000, LICOR Inc.) were conducted on agricultural fields in Western Denmark during one growing season. The leaf photosynthesis measurements provided the basis for estimating photosynthetic capacity. SPAD measurements and LAI was measured with a higher spatial and temporal resolution. SPAD readings were calibrated against Cab and Na analyzed on leaf material in the laboratory and later correlated to photosynthetic capacity. These data were used to parameterize a coupled photosynthesis and stomatal model that was run for the growing season 2012 to estimate NEE. As a part of the hydrological observatory HOBE (hobe.dk), fluxes of greenhouse gasses are continuously measured by eddy covariance systems at three field sites in the Skjern River Catchment, Western Denmark, providing the basis for estimating the exchange of energy, water vapour, and CO2 on canopy scale. One of the sites is situated at the field under investigation in the present study. Here we compare modeled NEE with the measured CO2 fluxes. The presented approach is shown to provide an efficient field sampling method for model parameterization with high temporal and spatial resolution and a physiological basis for scaling fluxes from leaf level to canopy scale. We further evaluate the potential for applying the model approach in connection with upscaling by means of satellite data.

  9. Tempering of Low-Temperature Bainite

    Science.gov (United States)

    Peet, Mathew J.; Babu, Sudarsanam Suresh; Miller, Mike K.; Bhadeshia, H. K. D. H.

    2017-07-01

    Electron microscopy, X-ray diffraction, and atom probe tomography have been used to identify the changes which occur during the tempering of a carbide-free bainitic steel transformed at 473 K (200 °C). Partitioning of solute between ferrite and thin-films of retained austenite was observed on tempering at 673 K (400 °C) for 30 minutes. After tempering at 673 K (400 °C) and 773 K (500 °C) for 30 minutes, cementite was observed in the form of nanometre scale precipitates. Proximity histograms showed that the partitioning of solutes other than silicon from the cementite was slight at 673 K (400 °C) and more obvious at 773 K (500 °C). In both cases, the nanometre scale carbides are greatly depleted in silicon.

  10. Klaus Winter (1930 - 2015)

    CERN Multimedia

    2015-01-01

    We learned with great sadness that Klaus Winter passed away on 9 February 2015, after a long illness.   Klaus was born in 1930 in Hamburg, where he obtained his diploma in physics in 1955. From 1955 to 1958 he held a scholarship at the Collège de France, where he received his doctorate in nuclear physics under the guidance of Francis Perrin. Klaus joined CERN in 1958, where he first participated in experiments on π+ and K0 decay properties at the PS, and later became the spokesperson of the CHOV Collaboration at the ISR. Starting in 1976, his work focused on experiments with the SPS neutrino beam. In 1984 he joined Ugo Amaldi to head the CHARM experiment, designed for detailed studies of the neutral current interactions of high-energy neutrinos, which had been discovered in 1973 using the Gargamelle bubble chamber at the PS. The unique feature of the detector was its target calorimeter, which used large Carrara marble plates as an absorber material. From 1984 to 1991, Klau...

  11. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    1995-01-13

    The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and State and local governments on the following topics: distillate fuel oil net production, imports and stocks on a US level and for all Petroleum Administration for Defense Districts (PADD) and product supplied on a US level; propane net production, imports and stocks on a US level and for PADD`s I, II, and III; natural gas supply and disposition and underground storage for the US and consumption for all PADD`s, as well as selected National average prices; residential and wholesale pricing data for heating oil and propane for those States participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the US and selected cities; and a 6-10 day, 30-Day, and 90-Day outlook for temperature and precipitation and US total heating degree-days by city.

  12. NEW Fe-C-Mn-Si-Cr BEARING ALLOY: TEMPERING CURVES AND TEMPERED MARTENSITE EMBRITTLEMENT

    Directory of Open Access Journals (Sweden)

    José Benedito Marcomini

    2012-12-01

    Full Text Available SAE 52100 steel is not only used as a rolled raw material for bearing manufacturing but for building some rolling devices as well, such as guide rollers and straightener rollers. The purpose of this work is the characterization of a Fe-C-Mn-Si-Cr bearing alloy (SAE 52100 steel, modified with 1.74% Si by plotting the variation of quenched and tempered hardness curve (tempering curve and tempered martensite embrittlement susceptibility. The present application is based on the same idea as 300M steel regarding SAE 4340 steel. The effect of silicon on the kinetics of cementite precipitation leads to a rise in temperature of tempered martensite embrittlement. Quench and temper treatments were carried out and impact tests were performed with modified and commercial steels and the results were compared. Microstructure aspects are studied by scanning electron microscopy and x-ray diffraction analysis. The silicon alloyed steel presents great resistance to softening after tempering and no tempered martensite embrittlement.

  13. Effects of over-winter green cover on soil solution nitrate concentrations beneath tillage land.

    Science.gov (United States)

    Premrov, Alina; Coxon, Catherine E; Hackett, Richard; Kirwan, Laura; Richards, Karl G

    2014-02-01

    There is a growing need to reduce nitrogen losses from agricultural systems to increase food production while reducing negative environmental impacts. The efficacy of vegetation cover for reducing nitrate leaching in tillage systems during fallow periods has been widely investigated. Nitrate leaching reductions by natural regeneration (i.e. growth of weeds and crop volunteers) have been investigated to a lesser extent than reductions by planted cover crops. This study compares the efficacy of natural regeneration and a sown cover crop (mustard) relative to no vegetative cover under both a reduced tillage system and conventional plough-based system as potential mitigation measures for reducing over-winter soil solution nitrate concentrations. The study was conducted over three winter fallow seasons on well drained soil, highly susceptible to leaching, under temperate maritime climatic conditions. Mustard cover crop under both reduced tillage and conventional ploughing was observed to be an effective measure for significantly reducing nitrate concentrations. Natural regeneration under reduced tillage was found to significantly reduce the soil solution nitrate concentrations. This was not the case for the natural regeneration under conventional ploughing. The improved efficacy of natural regeneration under reduced tillage could be a consequence of potential stimulation of seedling germination by the autumn reduced tillage practices and improved over-winter plant growth. There was no significant effect of tillage practices on nitrate concentrations. This study shows that over winter covers of mustard and natural regeneration, under reduced tillage, are effective measures for reducing nitrate concentrations in free draining temperate soils. © 2013.

  14. Modification of Low-Alloy Steel Surface by High-Temperature Gas Nitriding Plus Tempering

    Science.gov (United States)

    Jiao, Dongling; Li, Minsong; Ding, Hongzhen; Qiu, Wanqi; Luo, Chengping

    2018-01-01

    The low-alloy steel was nitrided in a pure NH3 gas atmosphere at 640 660 °C for 2 h, i.e., high-temperature gas nitriding (HTGN), followed by tempering at 225 °C, which can produce a high property surface coating without brittle compound (white) layer. The steel was also plasma nitriding for comparison. The composition, microstructure and microhardness of the nitrided and tempered specimens were examined, and their tribological behavior investigated. The results showed that the as-gas-nitrided layer consisted of a white layer composed of FeN0.095 phase (nitrided austenite) and a diffusional zone underneath the white layer. After tempering, the white layer was decomposed to a nano-sized (α-Fe + γ'-Fe4N + retained austenite) bainitic microstructure with a high hardness of 1150HV/25 g. Wear test results showed that the wear resistance and wear coefficient yielded by the complex HTGN plus tempering were considerably higher and lower, respectively, than those produced by the conventional plasma nitriding.

  15. A Transnational Temperance Discourse? William Wells Brown, Creole Civilization, and Temperate Manners

    Directory of Open Access Journals (Sweden)

    Carole Lynn Stewart

    2011-03-01

    Full Text Available

    In the nineteenth century, temperance movements provided the occasion for a transnational discourse. These conversations possessed an intensity throughout Britain and the United States. In America temperance often became associated with strongly nationalistic Euro-American forms of identity and internal purity. Nonetheless, African American reformers and abolitionists bound themselves to temperance ideals in forming civil societies that would heal persons and provide communal modes of democratic freedom in the aftermath and recovery from chattel slavery. This paper explores the possibilities of temperance as a transnational discourse by considering its meaning in the life and work of the African American author and activist, William Wells Brown. Brown expressed a “creole civilization” that employed the stylistics of the trickster as a unique mode of restraint that revealed a peculiar power of passivity that was able to claim efficacy over one’s life and community. This meaning of temperance diverges from and dovetails with certain European meanings of civilization that were being forged in the nineteenth century. Brown was in conversation with temperance reformers in America, Britain, and Europe. He imagined the possible meaning of temperance in African, Egyptian, Christian, and Islamic civilizations. He speculated upon the possibility of temperance as a defining characteristic of a transnational civilization and culture that would provide spaces for the expression of democratic freedom. Brown reimagined temperance as a form of corporeal restraint that offered a direct and sacred relation to the land, space, people that appeared in between an ethnic nationalist ethos and the European imperialistic civilization.

  16. Multisystem altruistic metadynamics—Well-tempered variant

    Science.gov (United States)

    Hošek, Petr; Kříž, Pavel; Toulcová, Daniela; Spiwok, Vojtěch

    2017-03-01

    Metadynamics method has been widely used to enhance sampling in molecular simulations. Its original form suffers two major drawbacks, poor convergence in complex (especially biomolecular) systems and its serial nature. The first drawback has been addressed by introduction of a convergent variant known as well-tempered metadynamics. The second was addressed by introduction of a parallel multisystem metadynamics referred to as altruistic metadynamics. Here, we combine both approaches into well-tempered altruistic metadynamics. We provide mathematical arguments and trial simulations to show that it accurately predicts free energy surfaces.

  17. Multisystem altruistic metadynamics-Well-tempered variant.

    Science.gov (United States)

    Hošek, Petr; Kříž, Pavel; Toulcová, Daniela; Spiwok, Vojtěch

    2017-03-28

    Metadynamics method has been widely used to enhance sampling in molecular simulations. Its original form suffers two major drawbacks, poor convergence in complex (especially biomolecular) systems and its serial nature. The first drawback has been addressed by introduction of a convergent variant known as well-tempered metadynamics. The second was addressed by introduction of a parallel multisystem metadynamics referred to as altruistic metadynamics. Here, we combine both approaches into well-tempered altruistic metadynamics. We provide mathematical arguments and trial simulations to show that it accurately predicts free energy surfaces.

  18. Warm-temperate deciduous forests around the Northern Hemisphere

    National Research Council Canada - National Science Library

    Box E.O; Fujiwara K

    2015-01-01

    Warm-temperate deciduous forests are "southern", mainly oak-dominated deciduous forests, as found over the warmer southern parts of the temperate deciduous forest regions of East Asia, Europe and eastern North America...

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

    Science.gov (United States)

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

    2011-03-01

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

  20. Impact of Early Sowing on Winter Wheat Receiving Manure or Mineral Fertilizers

    DEFF Research Database (Denmark)

    Christensen, Bent Tolstrup; Jensen, Johannes Lund; Thomsen, Ingrid Kaag

    2017-01-01

    To reduce over-winter nitrate leaching from temperate soil, nitrate catch crops can be grown between main crops. We hypothesize that earlier sowing can replace catch crops sown before winter wheat (Triticum aestivum L.) and improve wheat yields and N uptake. Early sown (late August) and timely sown...... (late September) wheat were tested over two cropping seasons (2011–2012 and 2013–2014) using two contemporary cultivars (Hereford and Mariboss) and increasing rates of N (0–300 kg total N ha–1) with animal manure (AM; cattle slurry) or mineral fertilizers (NPK), surface applied in late March. We...... to late August provided higher grain and straw yields; the increased over-winter N uptake suggests that the beneficial effect of earlier sowing may surpass that of a catch crop. Cattle slurry surface applied in late March gave poor N use efficiency and low grain protein content....

  1. Seasonal sediment dynamics shape temperate bedrock reef communities

    Science.gov (United States)

    Figurski, Jared D.; Freiwald, Jan; Lonhart, Steve I.; Storlazzi, Curt

    2016-01-01

    Mobilized seafloor sediment can impact benthic reef communities through burial, scour, and turbidity. These processes are ubiquitous in coastal oceans and, through their influence on the survival, fitness, and interactions of species, can alter the structure and function of benthic communities. In northern Monterey Bay, California, USA, as much as 30% of the seafloor is buried or exposed seasonally, making this an ideal location to test how subtidal temperate rocky reef communities vary in the presence and absence of chronic sediment-based disturbances. Designated dynamic plots were naturally inundated by sediment in summer (50 to 100% cover) and swept clean in winter, whereas designated stable plots remained free of sediment during our study. Multivariate analyses indicated significant differences in the structure of sessile and mobile communities between dynamic and stable reef habitats. For sessile species, community structure in disturbed plots was less variable in space and time than in stable plots due to the maintenance of an early successional state. In contrast, community structure of mobile species varied more in disturbed plots than in stable plots, reflecting how mobile species distribute in response to sediment dynamics. Some species were found only in these disturbed areas, suggesting that the spatial mosaic of disturbance could increase regional diversity. We discuss how the relative ability of species to tolerate disturbance at different life history stages and their ability to colonize habitat translate into community-level differences among habitats, and how this response varies between mobile and sessile communities.

  2. Modeling the distribution of water travel time through catchments using the tempered Levy (TOSS) density

    Science.gov (United States)

    Safeyeh Soltani, Sofie; Cvetkovic, Vladimir

    2017-04-01

    In this work we model the advective travel time distribution through a catchment focusing on groundwater. Our hypothesis is that the tempered Levy (or tempered one-sided stable) distribution (Cvetkovic et al., 2012) is suitable for quantifying travel time distributions in catchments; the hypothesis builds on the fact that the tempered Levy density generalizes most of the models that have been used in the literature (from plug flow, exponential and Gamma distributions, to ADE and anomalous models). The hypothesis is tested on thoroughly investigated and simulated Forsmark catchment (Sweden). Our approach is Lagrangian where we follow trajectories and compute first passage (arrival) times of passive tracer particles injected at recharge zones and monitored at different discharge zones. In this study we consider long-term, steady-state conditions. It is shown that asymptotically, the late arrivals are well reproduced by an inverse-Gaussian (ADE) model up to 10%, whereas early arrivals tend to be between the inverse-Gaussian and Gamma distributions. Comparison between the Lagrangian and Eulerian velocities indicates strong preferential flow in the catchment,where less than 5% of the Eulerian velocities contribute to advective transport over the simulated 375 years.

  3. Paleosol stable isotope evidence for early hominid occupation of East Asian temperate environments

    Science.gov (United States)

    Wang, Hongfang; Ambrose, S.H.; Liu, Chen; Follmer, L.R.

    1997-01-01

    Hominids left Africa and occupied mainland Asia by 1.8 myr ago. About 1.15 myr ago Homo erectus and an associated Stegodon-Ailuropoda fauna migrated from subtropical China across the Qinling Mountains into the temperate Loess Plateau. This migration may be an evolutionary milestone in human adaptability because it may represent the first occupation of a nontropical environment. Loess-paleosol stable isotope ratios from the last interglacial-glacial cycle provide comparative data for reconstructing the hominid paleoenvironments. The climate during Gongwangling hominid occupation about 1.15 myr ago was influenced by both Siberian-Mongolian winter and Indian summer monsoon systems characterized as a cold/cool, dry winter and warm/mild, semihumid summer and fall. The Gongwangling hominids preyed mainly on warm-climate-adapted animals such as Stegodon-Ailuropoda fauna, suggesting a warm season occupation. The stable isotope ratios also indicate that the Chenjiawo hominids occupied an environment similar to that of the Gongwangling about 650,000 yr ago. The associated fauna, with a mixture of forest and steppe, warm-and cold/cool-climate-adapted animal assemblage's, suggests a permanent occupation by this time. Thus, the reliable earliest and permanent occupation of temperate environments may have occurred 150,000 yr earlier in eastern Asia rather than in Europe. ?? 1997 University of Washington.

  4. The Temperance Movement and Social Work

    Science.gov (United States)

    Murdach, Allison D.

    2009-01-01

    This article examines a forgotten episode in social work history: the involvement of the profession in the temperance movement in the late 19th and early 20th centuries. Though some notable social workers such as Jane Addams, Robert A. Woods, and Representative Jeannette Rankin (the first woman elected to the U.S. Congress), championed the…

  5. Simulation of quenching and tempering of steels

    Science.gov (United States)

    Jin, Long

    An efficient simulation method, which includes microstructure, temperature and stress analysis applicable to both quenching and tempering processes, is developed and implemented using the commercial FEM package ABAQUS. This simulation encompasses phase transformations and their effects on the temperature distribution and stress/strain evolution, including the dependency of material properties on temperature and microstructure, transformation strains, latent heats and transformation plasticity. Three different multi-phase constitutive models, namely the average property model, the Voigt model and the Reuss model, have been implemented. The average property model is based on the linear mixture of material properties of different phase, while the Voigt model assumes the same strain field in all phases and the Reuss model assumes the iso-stress field. The simulation model has been applied to quenching and tempering of modified 4320 steel. Experiments of tempering and quenching on carburized circular plates of the same steel have been performed. The calculated distortion and residual stress profiles are in good agreement with corresponding measurements made in experiments and thus verifies the correctness of the model. The simulation model developed in this study is a useful design tool for quenching and tempering as well as machining of steels.

  6. The Challenge of Winter Backpacking.

    Science.gov (United States)

    Cavanaugh, Michael; Mapes, Alan

    1981-01-01

    Tips and techniques for safe and enjoyable winter backpacking are offered. Topics covered include cross county skis, snowshoes, clothing, footwear, shelter, sleeping bags, food, hypothermia prevention, as well as general rules and requirements. (CO)

  7. Winter waterfowl survey, southeastern Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Little is known of the total numbers of wintering waterfowl within the north pacific coastal region. The random stratified plot sampling methods used in 1980, as...

  8. Winter/Summer Monsoon Experiment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Winter/Summer Monsoon Experiment (MONEX) was conducted during the First Global GARP (Global Atmospheric Research Program) Experiment (FGGE). An international...

  9. Shining Light on "Dark Winter"

    National Research Council Canada - National Science Library

    Tara O'Toole; Michael Mair; Thomas V. Inglesby

    2002-01-01

    ... Security, and the Oklahoma National Memorial Institute for the Prevention of Terrorism, held a senior-level exercise entitled "Dark Winter" that simulated a covert smallpox attack on the United States...

  10. Modeling temperature inversion in southeastern Yellow Sea during winter 2016

    Science.gov (United States)

    Pang, Ig-Chan; Moon, Jae-Hong; Lee, Joon-Ho; Hong, Ji-Seok; Pang, Sung-Jun

    2017-05-01

    A significant temperature inversion with temperature differences larger than 3°C was observed in the southeastern Yellow Sea (YS) during February 2016. By analyzing in situ hydrographic profiles and results from a regional ocean model for the YS, this study examines the spatiotemporal evolution of the temperature inversion and its connection with wind-induced currents in winter. Observations reveal that in winter, when the northwesterly wind prevails over the YS, the temperature inversion occurs largely at the frontal zone southwest of Korea where warm/saline water of a Kuroshio origin meets cold/fresh coastal water. Our model successfully captures the temperature inversion observed in the winter of 2016 and suggests a close relation between northwesterly wind bursts and the occurrence of the large inversion. In this respect, the strong northwesterly wind drove cold coastal water southward in the upper layer via Ekman transport, which pushed the water mass southward and increased the sea level slope in the frontal zone in southeastern YS. The intensified sea level slope propagated northward away from the frontal zone as a shelf wave, causing a northward upwind flow response along the YS trough in the lower layer, thereby resulting in the large temperature inversion. Diagnostic analysis of the momentum balance shows that the westward pressure gradient, which developed with shelf wave propagation along the YS trough, was balanced with the Coriolis force in accordance with the northward upwind current in and around the inversion area.

  11. The role of seasonal flowering responses in adaptation of grasses to temperate climates.

    Directory of Open Access Journals (Sweden)

    Siri eFjellheim

    2014-08-01

    Full Text Available Grasses of the subfamily Pooideae, which includes important cereal crops and pasture grasses, are widespread in temperate zones. Seasonal regulation of developmental transitions coordinates the life cycles of Pooideae with the passing seasons, so that flowering and seed production coincide with favourable conditions in spring. This review examines the molecular pathways that control the seasonal flowering responses of Pooideae and how variation in the activity of genes controlling these pathways can adapt cereals or grasses to different climates and geographical regions. The possible evolutionary origins of the seasonal flowering responses of the Pooideae are discussed and key questions for future research highlighted. These include the need to develop a better understanding of the molecular basis for seasonal flowering in perennial Pooideae and in temperate grasses outside the core Pooideae group.

  12. The role of seasonal flowering responses in adaptation of grasses to temperate climates.

    Science.gov (United States)

    Fjellheim, Siri; Boden, Scott; Trevaskis, Ben

    2014-01-01

    Grasses of the subfamily Pooideae, including important cereal crops and pasture grasses, are widespread in temperate zones. Seasonal regulation of developmental transitions coordinates the life cycles of Pooideae with the passing seasons so that flowering and seed production coincide with favorable conditions in spring. This review examines the molecular pathways that control the seasonal flowering responses of Pooideae and how variation in the activity of genes controlling these pathways can adapt cereals or grasses to different climates and geographical regions. The possible evolutionary origins of the seasonal flowering responses of the Pooideae are discussed and key questions for future research highlighted. These include the need to develop a better understanding of the molecular basis for seasonal flowering in perennial Pooideae and in temperate grasses outside the core Pooideae group.

  13. What are the effects of agricultural management on soil organic carbon in boreo-temperate systems?

    DEFF Research Database (Denmark)

    Haddaway, Neal R.; Hedlund, Katarina; Jackson, Louise E.

    2015-01-01

    intensification has led to practices that may decrease soil organic carbon (SOC), and agricultural management has the potential to be a powerful tool for climate change mitigation and increased soil fertility through SOC sequestration. Here, we systematically map evidence relating to the impacts of agricultural...... management on SOC in arable systems of the warm temperate and snow climate zones (subset of temperate and continental climates: Köppen–Geiger Classification).......Background Soils contain the largest stock of organic carbon (C) in terrestrial ecosystems and changes in soil C stocks may significantly affect atmospheric CO2. A significant part of soil C is present in cultivated soils that occupy about 35 % of the global land surface. Agricultural...

  14. Marine Biodiversity in Temperate Western Australia: Multi-Taxon Surveys of Minden and Roe Reefs

    Directory of Open Access Journals (Sweden)

    Zoe Richards

    2016-03-01

    Full Text Available A growing body of evidence indicates that temperate marine ecosystems are being tropicalised due to the poleward extension of tropical species. Such climate mediated changes in species distribution patterns have the potential to profoundly alter temperate communities, as this advance can serve to push temperate taxa, many of which are southern Australian endemics, southward. These changes can lead to cascading effects for the biodiversity and function of coastal ecosystems, including contraction of ranges/habitats of sensitive cool water species. Hence there is growing concern for the future of Australia’s temperate marine biodiversity. Here we examine the diversity and abundance of marine flora and fauna at two reefs near Perth’s metropolitan area—Minden Reef and Roe Reef. We report the presence of 427 species of marine flora and fauna from eight taxon groups occurring in the Perth metropolitan area; at least three species of which appear to be new to science. Our data also extends the known range of 15 species, and in numerous instances, thousands of kilometres south from the Kimberley or Pilbara and verifies that tropicalisation of reef communities in the Perth metropolitan area is occurring. We report the presence of 24 species endemic to south-west Australia that may be at risk of range contractions with continued ocean warming. The results of these surveys add to our knowledge of local nearshore marine environments in the Perth metropolitan area and support the growing body of evidence that indicates a diverse and regionally significant marine fauna occurs in temperate Western Australia. Regular, repeated survey work across seasons is important in order to thoroughly document the status of marine biodiversity in this significant transition zone.

  15. The role of China's temperate forests in the atmospheric carbon budget

    Energy Technology Data Exchange (ETDEWEB)

    Xu, D.; Zhang, X.Q. [Chinese Academy of Forestry, Forest Ecology and Environment Inst., Beijing (China)

    2002-10-01

    Temperate forests are considered to be a net sink of atmospheric carbon. Approximately half of China's forests are located in the temperate zone. In addition, there remains a large area of land available for forest development, offering great potential for carbon uptake and for forests to play a vital role in the atmospheric carbon budget. The carbon emission and sequestration by temperate forests in the northern part of China in 1990 was calculated using the newly developed F-Carbon computer model and then projected for 60 years later. The data used was based on China's national forestry inventories, the national forestry development plan, and information from ecological research. Forests were classified into 5 age classes. The model considers the differences between biomass density and growth rates for the forests of different age classes, as well as the life time for biomass oxidation and decomposition. The changes in soil carbon between harvesting and reforestation were also estimated. It was shown that in 1990, the temperate forests in China had taken up 52.6 MtC, released 16.5 MtC and accumulated 6.1 MtC in forest soils. The net absorption was 42.2 MtC, representing 7.5 per cent of the national industrial carbon dioxide emissions in that year. It was predicted that in 2050, the net carbon uptake by China's temperate forests will be about 87.7 MtC. It was concluded that the greatest potential for carbon sequestration through forest development lies in the North and Northwestern region of China. 45 refs., 3 tabs., 5 figs.

  16. Winter climate change and fine root biogenic silica in sugar maple trees (Acer saccharum): Implications for silica in the Anthropocene

    Science.gov (United States)

    Maguire, Timothy J.; Templer, Pamela H.; Battles, John J.; Fulweiler, Robinson W.

    2017-03-01

    Winter temperatures are projected to increase over the next century, leading to reductions in winter snowpack and increased frequency of soil freezing in many northern forest ecosystems. Here we examine biogenic silica (BSi) concentrations in sugar maple (Acer saccharum) fine roots collected from a snow manipulation experiment at Hubbard Brook Experimental Forest (New Hampshire, USA). Increased soil freezing significantly lowered the BSi content of sugar maple fine roots potentially decreasing their capacity to take up water and dissolved nutrients. The reduced silica uptake (8 ± 1 kmol silica km-2) by sugar maple fine roots is comparable to silica export from temperate forest watersheds. We estimate that fine roots account for 29% of sugar maple BSi, despite accounting for only 4% of their biomass. These results suggest that increased frequency of soil freezing will reduce silica uptake by temperate tree roots, thereby changing silica availability in downstream receiving waters.

  17. Frost stress evolution and winter pea ideotype in the context of climate warming at a regional scale

    Directory of Open Access Journals (Sweden)

    Castel Thierry

    2017-01-01

    Full Text Available Pea (Pisum sativum L. is an important crop in temperate regions for its high seed protein concentration that is particularly sensitive to abiotic stresses. The abrupt temperature increase known as the “1987/1988 temperature regime shift” that occurs over Europe is questioning how winter pea will perform in the changing climate. This study assessed the winter frost damage evolution along from 1961 to 2015 in Burgundy-Franche-Comté by using: (1 daily observed and gridded regional temperature data and (2 a validated crop winter frost stress model calibrated for pea. This study shows a global decrease of the frost stress nevertheless resulting from a subtle balance between the decrease in its intensity and the increase of the number of events. The frost stress evolution patterns with warming depend on both plant frost resistance level and acclimation rate and are still sensitive to winter climate fluctuations. This study provides relevant information for breeding performant winter crop ideotypes able to moderate detrimental effects of climate change and offering new cropping opportunities in temperate regions.

  18. Hydrology and morphology of two river mouth regions (temperate Vistula Delta and subtropical Red River Delta

    Directory of Open Access Journals (Sweden)

    Zbigniew Pruszak

    2005-09-01

    Full Text Available The paper presents a comparative analysis of two different river mouths from two different geographical zones (subtropical and temperate climatic regions. One is the multi-branch and multi-spit mouth of the Red River on the Gulf of Tonkin (Vietnam, the other is the smaller delta of the river Vistula on a bay of the Baltic Sea (Poland. The analysis focuses on the similarities and differences in the hydrodynamics between these estuaries and the adjacent coastal zones, the features of sediment transport, and the long-term morphodynamics of the river outlets. Salinity and water level are also discussed, the latter also in the context of the anticipated global effect of accelerated sea level rise. The analysis shows that the climatic and environmental conditions associated with geographical zones give rise to fundamental differences in the generation and dynamic evolution of the river mouths.

  19. Sensitivity of temperate grassland species to elevated atmospheric CO2 and the interaction with temperature and water stress

    Directory of Open Access Journals (Sweden)

    M.B. JONES

    2008-12-01

    Full Text Available The annual cycle of growth of many temperate grasses is limited by low temperatures during the winter and spring and water stress during the summer. Climate change, induced by increase in the concentration of greenhouse gases in the atmosphere, can affect the growth and community structure of temperate grasslands in two ways. The first is directly through changes in atmospheric concentration of CO2 and the second is indirectly through changes in temperature and rainfall. At higher latitudes, where growth is largely temperature limited, it is probable that the direct effects of enhanced CO2 will be less than at low latitudes. However, interactions with increasing temperature and water stress are complex. Temperate grasslands range from intensively managed monocultures of sown species to speciesrich natural and semi-natural communities whose local distributions are controlled by variations in soil type and drainage. The different species can show marked differences in their responses to increasing CO2 concentrations, rising temperatures and water stress. This will probably result in major alterations in the community structure of temperate grasslands in the future. In addition to impacts on primary productivity and community structure, a long-term effect of elevated CO2 on grasslands is likely to be a significant increase in soil carbon storage. However, this may be counteracted by increases in temperature.;

  20. NEARSHORE ZONE

    African Journals Online (AJOL)

    hb"'/ H“ —_'~. Fig. l: Schematic plan showing the incident wave and subsequent breaking in the nearshore zone. The still-water line indicates the mean water level and .... obtained by taking the square of the high frequency velocity components.

  1. Yield and adaptive potential of modern varieties of soft winter wheat in the Northern Steppe conditions

    Directory of Open Access Journals (Sweden)

    М. М. Солодушко

    2014-11-01

    Full Text Available Results obtained during the study of special features of cultivation and productivity of soft winter wheat varieties that differ by origin in the Steppe zone in Ukraine are presented. Relevance of the executed work was determined by ambiguous assessment and selection of available soft winter wheat variety assortment that is used in Steppe zone farms. Findings allow to find out  and expose to a greater extent unused reserves for increasing the croppage level. It was found in the process of the study that now according to comprehensive assessment the best varieties of a soft winter wheat for corn growers in the steppe zone are Smuhlianka, Epokha odes`ka, Kiriia, Zolotokolosa, Blahodarka odes`ka, Bohdana, Lyst 25, Rozkishna.

  2. World temperate fruit production: characteristics and challenges

    Directory of Open Access Journals (Sweden)

    Jorge B. Retamales

    2011-10-01

    Full Text Available In the last 30 years world population has increased 70% but per capita global fruit consumption is only 20% higher. Even though tropical and temperate fruit have similar contributions to the 50 kg/person/year of US consumption of fresh fruit, in the last 30 years this has been slightly greater for temperate fruit. Within fruit consumption, the largest expansion has been for organic fruit which increased more than 50% in the 2002-2006 period. The largest expansion of area planted in the 1996-2006 has been for kiwi (29% and blueberries (20%, while apples (-24% and sour cherries (-13% have had the largest reductions. Nearly 50% of the total global volume of fruit is produced by 5 countries: China, USA, Brazil, Italy and Spain. The main producer (China accounts for 23% of the total. While the main exporters are Spain, USA and Italy, the main importers are Germany, Russia and UK. Demands for the industry have evolved towards quality, food safety and traceability. The industry faces higher productions costs (labor, energy, agrichemicals. The retailers are moving towards consolidation while the customers are changing preferences (food for health. In this context there is greater pressure on growers, processors and retailers. Emerging issues are labor supply, climate change, water availability and sustainability. Recent developments in precision agriculture, molecular biology, phenomics, crop modelling and post harvest physiology should increase yields and quality, and reduce costs for temperate fruit production around the world.

  3. The importance of phenology for the evaluation of impact of climate change on growth of boreal, temperate and Mediterranean forests [sic] ecosystems: an overview

    NARCIS (Netherlands)

    Kramer, K.; Leinonen, I.; Loustau, D.

    2000-01-01

    An overview is presented of the phenological models relevant for boreal coniferous, temperate-zone deciduous and Mediterranean coniferous forest ecosystems. The phenology of the boreal forests is mainly driven by temperature, affecting the timing of the start of the growing season and thereby its

  4. Analysis of grain characters in temperate grasses reveals distinctive patterns of endosperm organization associated with grain shape

    OpenAIRE

    Hands, Philip; Kourmpetli, Sofia; Sharples, Donna; Harris, Robert G.; Drea, Sinéad

    2012-01-01

    Members of the core pooids represent the most important crops in temperate zones including wheat, barley, and oats. Their importance as crops is largely due to the grain, particularly the storage capabilities of the endosperm. In this study, a comprehensive survey of grain morphology and endosperm organization in representatives of wild and cultivated species throughout the core pooids was performed. As sister to the core pooid tribes Poeae, Aveneae, Triticeae, and Bromeae within the Pooideae...

  5. Influence of Low Frequency Variability on Climate and Carbon Fluxes in a Temperate Pine Forest in Eastern Canada

    Directory of Open Access Journals (Sweden)

    Robin Thorne

    2015-08-01

    Full Text Available Carbon, water and energy exchanges between forests and the atmosphere depend upon seasonal dynamics of both temperature and precipitation, which are influenced by low frequency climate oscillations such as: El Niño-Southern Oscillation (ENSO, North Atlantic Oscillation (NAO, Arctic Oscillation (AO, Eastern Pacific Oscillation (EPO and the Pacific-North American (PNA. This study investigated the influence of climate oscillations on the local climate and carbon fluxes in a 75-year old temperate pine (Pinus strobus L. forest, near Lake Erie in southern Ontario, Canada. Analyses indicated mean winter temperatures were correlated to NAO, AO and EPO, total winter precipitation was influenced by PNA and AO, while total snowfall was correlated with PNA and ENSO. These impacts influenced carbon dynamics of the forest during the winter and spring seasons. The EPO had a significant inverse correlation with winter and spring carbon fluxes, while the Pacific Decadal Oscillation (PDO was significantly correlated with winter respiration. In 2012, an extreme warm event linked to climate oscillations raised temperatures and resulted in a large release of carbon from the forest due to higher ecosystem respiration. As low frequency climate oscillations are important drivers of extreme weather events, affecting their intensity, frequency and spatial patterns, they can cause large changes in carbon exchanges in forest ecosystems in the northeastern parts of North America.

  6. Oceanic temperate forest versus warm temperate rainforest: a reply to Grubb et al. (2017)

    DEFF Research Database (Denmark)

    McGlone, Matt S.; Buitenwerf, Robert; Richardson, Sarah J.

    2017-01-01

    that they ‘see no virtue in using climatic variables to define a [vegetation] formation type’, and then discuss problems with the climate- based global biome schemes of Holdridge (1947), Whittaker (1970), Box (1981) and Prentice et al. (1992). As our oceanic temperate forest (OTF) concept is underpinned......Grubb et al. (2017) point out that we (McGlone et al. 2016) erroneously stated that the definition of warm temperate rain forest (WTRF; Grubb et al. 2013) was based in part on climatic criteria. We apologise: their text made clear that this was not the case. However, they go on to say...... by climatic variables, and as they suggest that it largely falls within their WTRF and cool temperate rain forest (CTRF) concepts, we take this opportunity to further discuss the relative merits of these contrasting ways of classifying vegetation cover....

  7. Ecological Causes and Consequences of Intratropical Migration in Temperate-Breeding Migratory Birds.

    Science.gov (United States)

    Stutchbury, Bridget J M; Siddiqui, Raafia; Applegate, Kelly; Hvenegaard, Glen T; Mammenga, Paul; Mickle, Nanette; Pearman, Myrna; Ray, James D; Savage, Anne; Shaheen, Tim; Fraser, Kevin C

    2016-09-01

    New discoveries from direct tracking of temperate-breeding passerines show that intratropical migration (ITM) occurs in a growing number of species, which has important implications for understanding their evolution of migration, population dynamics, and conservation needs. Our large sample size ([Formula: see text]) for purple martins (Progne subis subis) tracked with geolocators to winter sites in Brazil, combined with geolocator deployments at breeding colonies across North America, allowed us to test hypotheses for ITM, something which has not yet been possible to do for other species. ITM in purple martins was not obligate; only 44% of individuals exhibited ITM, and movements were not coordinated in time or space. We found no evidence to support the resource hypothesis; rainfall and temperature experienced by individual birds during their last 2 weeks at their first roost site were similar to conditions at their second roost site after ITM. Birds generally migrated away from the heavily forested northwestern Amazon to less forested regions to the south and east. ITM in this aerial insectivore appears to support the competition-avoidance hypothesis and may be triggered by increasing local density in the core wintering region. Full life cycle models and migratory networks will need to incorporate ITM to properly address seasonal carryover effects and identify which wintering regions are most important for conservation.

  8. Seasonal determinations of algal virus decay rates reveal overwintering in a temperate freshwater pond.

    Science.gov (United States)

    Long, Andrew M; Short, Steven M

    2016-07-01

    To address questions about algal virus persistence (i.e., continued existence) in the environment, rates of decay of infectivity for two viruses that infect Chlorella-like algae, ATCV-1 and CVM-1, and a virus that infects the prymnesiophyte Chrysochromulina parva, CpV-BQ1, were estimated from in situ incubations in a temperate, seasonally frozen pond. A series of experiments were conducted to estimate rates of decay of infectivity in all four seasons with incubations lasting 21 days in spring, summer and autumn, and 126 days in winter. Decay rates observed across this study were relatively low compared with previous estimates obtained for other algal viruses, and ranged from 0.012 to 11% h(-1). Overall, the virus CpV-BQ1 decayed most rapidly whereas ATCV-1 decayed most slowly, but for all viruses the highest decay rates were observed during the summer and the lowest were observed during the winter. Furthermore, the winter incubations revealed the ability of each virus to overwinter under ice as ATCV-1, CVM-1 and CpV-BQ1 retained up to 48%, 19% and 9% of their infectivity after 126 days, respectively. The observed resilience of algal viruses in a seasonally frozen freshwater pond provides a mechanism that can support the maintenance of viral seed banks in nature. However, the high rates of decay observed in the summer demonstrate that virus survival and therefore environmental persistence can be subject to seasonal bottlenecks.

  9. Sound Zones

    DEFF Research Database (Denmark)

    Møller, Martin Bo; Olsen, Martin

    2017-01-01

    Sound zones, i.e. spatially confined regions of individual audio content, can be created by appropriate filtering of the desired audio signals reproduced by an array of loudspeakers. The challenge of designing filters for sound zones is twofold: First, the filtered responses should generate...... an acoustic separation between the control regions. Secondly, the pre- and post-ringing as well as spectral deterioration introduced by the filters should be minimized. The tradeoff between acoustic separation and filter ringing is the focus of this paper. A weighted L2-norm penalty is introduced in the sound...

  10. PENGARUH VARIASI SUHU PADA PROSES SELF TEMPERING DAN VARIASI WAKTU TAHAN PADA PROSES TEMPERING TERHADAP SIFAT MEKANIS BAJA AISI 4140

    Directory of Open Access Journals (Sweden)

    Sunardi Sunardi

    2016-07-01

    Full Text Available Tujuan penelitian ini adalah untuk mengetahui sifat mekanis pada baja AISI 4140 dengan proses tempering dengan variasi waktu tahan dan variasi suhu pada proses self tempering. Material terlebih dahulu dipanaskan pada suhu 850°C, di tahan dengan waktu 14 dan 28 menit, media pendinginan adalah Oli SAE 20. Pada proses tempering baja dipanaskan kembali dengan suhu 200°C di tahan dengan waktu 30 dan 120 menit. Sedangkan untuk proses self tempering, baja di panaskan pada suhu 850°C di tahan dengan waktu 14 dan 28 menit kemudian didinginkan, suhu yang harus dicapai pada pendinginan adalah 200°C, 400°C dan 600°C. Proses tempering dengan variasi waktu tahan mempunyai nilai kekerasan terbesar 50,1 HRC dengan waktu tahan 120 menit, sedangkan nilai kekerasan terbesar pada proses self tempering dengan variasi suhu adalah 29,68 HRC pada suhu 200°C. Nilai ketangguhan terbesar pada saat proses tempering adalah 0,341 (J/mm2 dengan waktu tahan 120 menit, sedangkan pada saat proses self tempering ketangguhan terbesar pada suhu 600°C dengan nilai 0,375 (J/mm2. Laju korosi terbesar pada saat tempering adalah 0,055 (mpy dengan waktu tahan 30 menit, sedangkan pada saat proses self tempering laju korosi terbesar pada suhu 400°C dengan nilai 0,0388 (mpy. 

  11. Eikenprocessierups doorstaat koude winter goed

    NARCIS (Netherlands)

    Mulder, S.

    2010-01-01

    Eikenprocessierupsen zijn niet gedeerd door de langdurige koude van deze winter. Bij het opensnijden van eipakketjes blijken de rupsjes springlevend naar buiten te komen. Het is nog te vroeg om nu al iets te zeggen over de mogelijke overlast later dit jaar. Dat is afhankelijk van de

  12. Seasonal habitat selection by lake trout (Salvelinus namaycush) in a small Canadian shield lake: Constraints imposed by winter conditions

    Science.gov (United States)

    Blanchfield, P.J.; Tate, L.S.; Plumb, J.M.; Acolas, M.-L.; Beaty, K.G.

    2009-01-01

    The need for cold, well-oxygenated waters significantly reduces the habitat available for lake trout (Salvelinus namaycush) during stratification of small temperate lakes. We examined the spatial and pelagic distribution of lake trout over two consecutive summers and winters and tested whether winter increased habitat availability and access to littoral regions in a boreal shield lake in which pelagic prey fish are absent. In winter, lake trout had a narrowly defined pelagic distribution that was skewed to the upper 3 m of the water column and spatially situated in the central region of the lake. Individual core areas of use (50% Kernel utilization distributions) in winter were much reduced (75%) and spatially non-overlapping compared to summer areas, but activity levels were similar between seasons. Winter habitat selection is in contrast to observations from the stratified season, when lake trout were consistently located in much deeper waters (>6 m) and widely distributed throughout the lake. Winter distribution of lake trout appeared to be strongly influenced by ambient light levels; snow depth and day length accounted for up to 69% of the variation in daily median fish depth. More restricted habitat use during winter than summer was in contrast to our original prediction and illustrates that a different suite of factors influence lake trout distribution between these seasons. ?? Springer Science+Business Media B.V. 2009.

  13. Biodiversity of Chironomidae at the North Temperate Lakes LTER Site

    Science.gov (United States)

    Berg, M. B.; Olson, S.; Hayford, B.; Gresens, S. E.; Kennedy, J.; Bouchard, R. W.; Ferrington, L. C.

    2005-05-01

    The National Science Foundation has established a network of Long Term Ecological Research (LTER) sites to enhance research at large spatial scales, extended temporal scales, and to facilitate intersite comparisons of system structure and processes. Present knowledge of Chironomidae community structure at LTER sites is insufficient to accomplish these goals. Our project objectives are to determine species composition of Chironomidae in a wide variety of aquatic habitats at LTERs, describe all undescribed species/life stage associations, determine the temporal seasonality of emergence and develop a data base of species by habitat and emergence times. Our methods include light trapping and sweep netting for adults, dip-netting and hand-picking wood/aquatic vegetation for larvae, collecting surface-floating pupal exuviae, and rearing to associate life stages. Our initial focus on the North Temperate Lakes LTER in Wisconsin and has documented 80 genera (representing > 125 species, including 18 undescribed species and/or unknown life stages) from 11 lakes, 5 streams and 2 bogs. Taxa include species with larvae that are: epiphytic, endophytic, xylophagic, phoretic on mollusks or other aquatic insects, specialized to feed on freshwater sponges, predators of black fly pupae, and those occurring in hyporheic zones, marginal semi-aquatic habitats or terrestrial soils.

  14. Simulated Tempering and Swapping on Mean-Field Models

    OpenAIRE

    Bhatnagar, Nayantara; Randall, Dana

    2015-01-01

    Simulated and parallel tempering are families of Markov Chain Monte Carlo algorithms where a temperature parameter is varied during the simulation to overcome bottlenecks to convergence due to multimodality. In this work we introduce and analyze the convergence for a set of new tempering distributions which we call \\textit{entropy dampening}. For asymmetric exponential distributions and the mean field Ising model with and external field simulated tempering is known to converge slowly. We show...

  15. Winter respiratory C losses provide explanatory power for net ecosystem productivity

    Czech Academy of Sciences Publication Activity Database

    Haeni, M.; Zweifel, R.; Eugster, W.; Gessler, A.; Zielis, S.; Bernhofer, C.; Carrara, A.; Gruenwald, T.; Havránková, Kateřina; Heinesch, B.; Herbst, M.; Ibrom, A.; Knohl, A.; Lagergren, F.; Law, B. E.; Marek, Michal V.; Matteucci, G.; McCaughey, J. H.; Minerbi, S.; Montagnani, L.; Moors, E.; Olejnik, Janusz; Pavelka, Marian; Pilegaard, K.; Pita, G.; Rodrigues, A.; Sanz Sanchez, M. J.; Schelhaas, M.J.; Urbaniak, M.; Valentini, R.; Varlagin, A.; Vesala, T.; Vincke, C.; Wu, J.; Buchmann, N.

    2017-01-01

    Roč. 122, č. 1 (2017), s. 243-260 ISSN 2169-8953 R&D Projects: GA MŠk(CZ) LO1415 Grant - others:COST(IT) FP0903 Action Institutional support: RVO:68378076 Keywords : spaceborne imaging spectroscopy * temperate deciduous forest * mixedwood boreal forest * beech fagus-sylvatica * water-vapor exchange * stem radius change s * carbon uptake * interannual variability * photosynthetic capacity * leaf characteristics * eddy covariance * CO2 exchange * carbon sink * carbon source * growing season length * winter respiration Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.395, year: 2016

  16. Xanthophyll cycle pigment and antioxidant profiles of winter-red (anthocyanic) and winter-green (acyanic) angiosperm evergreen species.

    Science.gov (United States)

    Hughes, Nicole M; Burkey, Kent O; Cavender-Bares, Jeannine; Smith, William K

    2012-03-01

    Leaves of many angiosperm evergreen species change colour from green to red during winter, corresponding with the synthesis of anthocyanin pigments. The ecophysiological function of winter colour change (if any), and why it occurs in some species and not others, are not yet understood. It was hypothesized that anthocyanins play a compensatory photoprotective role in species with limited capacity for energy dissipation. Seasonal xanthophyll pigment content, chlorophyll fluorescence, leaf nitrogen, and low molecular weight antioxidants (LMWA) of five winter-red and five winter-green angiosperm evergreen species were compared. Our results showed no difference in seasonal xanthophyll pigment content (V+A+Z g(-1) leaf dry mass) or LMWA between winter-red and winter-green species, indicating red-leafed species are not deficient in their capacity for non-photochemical energy dissipation via these mechanisms. Winter-red and winter-green species also did not differ in percentage leaf nitrogen, corroborating previous studies showing no difference in seasonal photosynthesis under saturating irradiance. Consistent with a photoprotective function of anthocyanin, winter-red species had significantly lower xanthophyll content per unit chlorophyll and less sustained photoinhibition than winter-green species (i.e. higher pre-dawn F(v)/F(m) and a lower proportion of de-epoxidized xanthophylls retained overnight). Red-leafed species also maintained a higher maximum quantum yield efficiency of PSII at midday (F'(v)/F'(m)) during winter, and showed characteristics of shade acclimation (positive correlation between anthocyanin and chlorophyll content, and negative correlation with chlorophyll a/b). These results suggest that the capacity for photon energy dissipation (photochemical and non-photochemical) is not limited in red-leafed species, and that anthocyanins more likely function as an alternative photoprotective strategy to increased VAZ/Chl during winter.

  17. Evolution of cold-tolerant fungal symbionts permits winter fungiculture by leafcutter ants at the northern frontier of a tropical ant-fungus symbiosis.

    Science.gov (United States)

    Mueller, Ulrich G; Mikheyev, Alexander S; Hong, Eunki; Sen, Ruchira; Warren, Dan L; Solomon, Scott E; Ishak, Heather D; Cooper, Mike; Miller, Jessica L; Shaffer, Kimberly A; Juenger, Thomas E

    2011-03-08

    The obligate mutualism between leafcutter ants and their Attamyces fungi originated 8 to 12 million years ago in the tropics, but extends today also into temperate regions in South and North America. The northernmost leafcutter ant Atta texana sustains fungiculture during winter temperatures that would harm the cold-sensitive Attamyces cultivars of tropical leafcutter ants. Cold-tolerance of Attamyces cultivars increases with winter harshness along a south-to-north temperature gradient across the range of A. texana, indicating selection for cold-tolerant Attamyces variants along the temperature cline. Ecological niche modeling corroborates winter temperature as a key range-limiting factor impeding northward expansion of A. texana. The northernmost A. texana populations are able to sustain fungiculture throughout winter because of their cold-adapted fungi and because of seasonal, vertical garden relocation (maintaining gardens deep in the ground in winter to protect them from extreme cold, then moving gardens to warmer, shallow depths in spring). Although the origin of leafcutter fungiculture was an evolutionary breakthrough that revolutionized the food niche of tropical fungus-growing ants, the original adaptations of this host-microbe symbiosis to tropical temperatures and the dependence on cold-sensitive fungal symbionts eventually constrained expansion into temperate habitats. Evolution of cold-tolerant fungi within the symbiosis relaxed constraints on winter fungiculture at the northern frontier of the leafcutter ant distribution, thereby expanding the ecological niche of an obligate host-microbe symbiosis.

  18. Trichinella in arctic, subarctic and temperate regions

    DEFF Research Database (Denmark)

    Kapel, C. M O

    1997-01-01

    and the human activity are all very important interacting factors affecting epidemiology. In Greenland, where only sylvatic trichinellosis is present, the high prevalence in wildlife appears closely connected with polar bear hunting. In the Scandinavian countries, the prevalence of both sylvatic and domestic......The transmission and occurrence of Trichinella spp according to the zoogeography of different climatic conditions, socioeconomy and human activity are discussed. Comparing arctic, subarctic and temperate regions, it appears that the species of Trichinella present, the composition of the fauna...... populations may have epidemiological importance in relation to the recent changes in production and infrastructure in these former Soviet states....

  19. Extended Hamiltonian approach to continuous tempering.

    Science.gov (United States)

    Gobbo, Gianpaolo; Leimkuhler, Benedict J

    2015-06-01

    We introduce an enhanced sampling simulation technique based on continuous tempering, i.e., on continuously varying the temperature of the system under investigation. Our approach is mathematically straightforward, being based on an extended Hamiltonian formulation in which an auxiliary degree of freedom, determining the effective temperature, is coupled to the physical system. The physical system and its temperature evolve continuously in time according to the equations of motion derived from the extended Hamiltonian. Due to the Hamiltonian structure, it is easy to show that a particular subset of the configurations of the extended system is distributed according to the canonical ensemble for the physical system at the correct physical temperature.

  20. A temperature predictor for parallel tempering simulations.

    Science.gov (United States)

    Patriksson, Alexandra; van der Spoel, David

    2008-04-21

    An algorithm is proposed that generates a set of temperatures for use in parallel tempering simulations (also known as temperature-replica exchange molecular dynamics simulations) of proteins to obtain a desired exchange probability Pdes. The input consists of the number of protein atoms and water molecules in the system, information about the use of constraints and virtual sites and the lower temperature limits. The temperatures generated yield probabilities which are very close to Pdes (correlation 97%), independent of force field and over a wide temperature range. To facilitate its use, the algorithm has been implemented as a web server at .

  1. Oceanic temperate forest versus warm temperate rainforest: a reply to Grubb et al. (2017)

    DEFF Research Database (Denmark)

    Buitenwerf, Robert

    2017-01-01

    Grubb et al. (2017) point out that we (McGlone et al. 2016) erroneously stated that the definition of warm temperate rain forest (WTRF; Grubb et al. 2013) was based in part on climatic criteria. We apologise: their text made clear that this was not the case. However, they go on to say that they ‘...

  2. Mexican Mid-winter Waterfowl Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Mexican Mid-winter Waterfowl Survey is a continuation of the annual winter waterfowl survey which is conducted in the United States and Mexico. Since the...

  3. Essential Outdoor Sun Safety Tips for Winter

    Science.gov (United States)

    ... Weekend Warriors expand/collapse Vitamin D Essential Outdoor Sun Safety Tips for Winter Winter sports enthusiasts are ... skiing! Be Mindful of Time Spent in the Sun, Regardless of the Season If possible, ski early ...

  4. Variation in carbon storage and its distribution by stand age and forest type in boreal and temperate forests in northeastern China.

    Science.gov (United States)

    Wei, Yawei; Li, Maihe; Chen, Hua; Lewis, Bernard J; Yu, Dapao; Zhou, Li; Zhou, Wangming; Fang, Xiangmin; Zhao, Wei; Dai, Limin

    2013-01-01

    The northeastern forest region of China is an important component of total temperate and boreal forests in the northern hemisphere. But how carbon (C) pool size and distribution varies among tree, understory, forest floor and soil components, and across stand ages remains unclear. To address this knowledge gap, we selected three major temperate and two major boreal forest types in northeastern (NE) China. Within both forest zones, we focused on four stand age classes (young, mid-aged, mature and over-mature). Results showed that total C storage was greater in temperate than in boreal forests, and greater in older than in younger stands. Tree biomass C was the main C component, and its contribution to the total forest C storage increased with increasing stand age. It ranged from 27.7% in young to 62.8% in over-mature stands in boreal forests and from 26.5% in young to 72.8% in over-mature stands in temperate forests. Results from both forest zones thus confirm the large biomass C storage capacity of old-growth forests. Tree biomass C was influenced by forest zone, stand age, and forest type. Soil C contribution to total forest C storage ranged from 62.5% in young to 30.1% in over-mature stands in boreal and from 70.1% in young to 26.0% in over-mature in temperate forests. Thus soil C storage is a major C pool in forests of NE China. On the other hand, understory and forest floor C jointly contained less than 13% and boreal and temperate forests respectively, and thus play a minor role in total forest C storage in NE China.

  5. Effects of initial temperature and tempering medium on thermal tempering of dental porcelains.

    Science.gov (United States)

    Hojjatie, B; Anusavice, K J

    1993-03-01

    The objective of this study was to test the hypothesis that quenching of porcelain in silicone oil rather than in compressed air will significantly increase the flexure strength by reducing the potential for crack formation during transient cooling. A secondary hypothesis to be tested is that the initial tempering temperature can be reduced significantly below the porcelain maturing temperature of 982 degrees C but well above Tg without a decrease in strength. Opaque-body porcelain disks, 16 mm in diameter and 2 mm in thickness, with a thermal contraction mismatch (delta alpha) of -1.5, 0, and +3.2 ppm/degrees C were tempered from initial temperatures of 650, 750, 850, and 982 degrees C in silicone oil with kinematic viscosities of 50, 1000, and 5000 centistokes. Porcelain disks were also subjected to three cooling procedures in air: slow cooling in a furnace (SC), free convective cooling in a laboratory bench (FC), and tempering (T) by blasting the surface of body porcelain with air. The crack size induced by a Vickers microhardness indenter was measured within one minute after crack development. For determination of the influence of initial cooling temperature on biaxial flexure strength, six body porcelain disks (delta alpha = 0) were tempered in air from initial temperatures of 650, 750, 850, and 982 degrees C. The mean crack size of specimens tempered in oil was significantly smaller (p < or = 0.001) than that of specimens that were slowly-cooled or fast-cooled in air for all thermal contraction mismatch cases.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Quaternary phylogeography: the roots of hybrid zones.

    Science.gov (United States)

    Hewitt, Godfrey M

    2011-05-01

    The older history of hybrid zones is explored through consideration of recent advances in climatology, paleontology and phylogeography in the Late Cenozoic, particularly the Quaternary Period with its major climatic cycles. The fossil record shows that these ice ages and their nested millennial oscillations caused substantial changes in species distributions and with genetic evidence allows deduction of refugia and colonization routes in arctic, temperate, desert and tropical regions. The age of divergence between hybridizing lineages varies from the Late Pleistocene to the Late Miocene, implying much range change and varying selection on sister lineages. Hybridizing lineages in the Tropical and Temperate regions range in age from young to old, but those studied in the Arctic are no more than a few ice ages old and their refugial roots are not clear. Mid to low latitude regions often show parapatric patchworks of lineages and multiple refugia stable through many climatic oscillations. Particular hybrid zones may have formed more than once; while some expansions were not the same, producing reticulation and introgression in previous glacial cycles. Hybrid-zone roots are complex and deep, and considerations of their complexity can reveal evolutionary pathways of species. They are indeed windows on evolution.

  7. Seedling growth and biomass allocation in relation to leaf habit and shade tolerance among 10 temperate tree species.

    Science.gov (United States)

    Modrzyński, Jerzy; Chmura, Daniel J; Tjoelker, Mark G

    2015-08-01

    Initial growth of germinated seeds is an important life history stage, critical for establishment and succession in forests. Important questions remain regarding the differences among species in early growth potential arising from shade tolerance. In addition, the role of leaf habit in shaping relationships underlying shade tolerance-related differences in seedling growth remains unresolved. In this study we examined variation in morphological and physiological traits among seedlings of 10 forest tree species of the European temperate zone varying in shade tolerance and leaf habit (broadleaved winter-deciduous species vs needle-leaved conifers) during a 10-week period. Seeds were germinated and grown in a controlled environment simulating an intermediate forest understory light environment to resolve species differences in initial growth and biomass allocation. In the high-resource experimental conditions during the study, seedlings increased biomass allocation to roots at the cost of leaf biomass independent of shade tolerance and leaf habit. Strong correlations between relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf mass fraction (LMF) indicate that physiology and biomass allocation were equally important determinants of RGR as plant structure and leaf morphology among these species. Our findings highlight the importance of seed mass- and seed size-related root morphology (specific root length-SRL) for shade tolerance during early ontogeny. Leaf and plant morphology (SLA, LAR) were more successful in explaining variation among species due to leaf habit than shade tolerance. In both broadleaves and conifers, shade-tolerant species had lower SRL and greater allocation of biomass to stems (stem mass fraction). Light-seeded shade-intolerant species with greater SRL had greater RGR in both leaf habit groups. However, the greatest plant mass was accumulated in the group of heavy-seeded shade

  8. Leadership in American Indian Communities: Winter Lessons

    Science.gov (United States)

    Metoyer, Cheryl A.

    2010-01-01

    Winter lessons, or stories told in the winter, were one of the ways in which tribal elders instructed and directed young men and women in the proper ways to assume leadership responsibilities. Winter lessons stressed the appropriate relationship between the leader and the community. The intent was to remember the power and purpose of that…

  9. Estimativa de horas de frio abaixo de 7 e de 13°C para regionalização da fruticultura de clima temperado no estado de São Paulo Temperate fruit crop zoning in the State of São Paulo - Brazil based upon estimated number of hours with temperature below 7 and 13°C

    Directory of Open Access Journals (Sweden)

    Mário J. Pedro Júnior

    1979-01-01

    Full Text Available Estimativa e mapeamento do número de horas com temperaturas abaixo de 7 e 13°C no Estado de São Paulo e análise comparativa do comportamento de fruteiras de clima temperado constituem os objetivos do presente trabalho. Foi cotado o número de horas com temperaturas inferiores a 7 e 13°C, índices considerados limites necessários à dormência dessas plantas. Foram selecionados termogramas de doze postos agrometeorológicos do Instituto Agronômico, situados em altitudes variáveis entre 25 e 1.000m, correspondentes ao período 1964-1973. Estabeleceram-se equações para estimativa do número de horas com temperaturas inferiores a 7°C (HF-7 e 13°C (HF-13 em função da temperatura média do mês de julho, cujos coeficientes de correlação foram de -0,88 e -0,93, respectivamente. Com base nessas equações foram mapeadas as isolinhas de HF-7 e HF-13 para o Estado de São Paulo, encontrando-se desde valores médios anuais de HF-7 inferiores a 20 horas, característicos das regiões de transição de clima mesotérmico a megatérmico do Planalto Ocidental e das regiões mais baixas do norte e oeste do Estado, até valores anuais de HF-7 superiores a 200 horas, característicos das áreas acima de 1.500 metros de altitude no Sul do Estado, na serra da Mantiqueira, limítrofe com Minas Gerais, e na serra do Mar, limítrofe com o Rio de Janeiro. Com base na introdução de diferentes frutíferas de clima temperado no Estado de São Paulo, verificou-se uma relação muito grande entre os índices HF-7 e HF-13 mapeados com o comportamento e potencialidade de exploração comercial.The behavior of temperate climate fruit crops in the State of São Paulo - Brazil as function of "dormancy units" (DAMARIO, 1969 was analysed with the object of providing a simple method for mapping areas with aptitude for commercial development of the crop trees. Thermographs from 12 agrometeorological stations located at altitudes varying from 25 to 1000 meters above

  10. Not-so-well-tempered neutralino

    Science.gov (United States)

    Profumo, Stefano; Stefaniak, Tim; Stephenson-Haskins, Laurel

    2017-09-01

    Light electroweakinos, the neutral and charged fermionic supersymmetric partners of the standard model SU (2 )×U (1 ) gauge bosons and of the two SU(2) Higgs doublets, are an important target for searches for new physics with the Large Hadron Collider (LHC). However, if the lightest neutralino is the dark matter, constraints from direct dark matter detection experiments rule out large swaths of the parameter space accessible to the LHC, including in large part the so-called "well-tempered" neutralinos. We focus on the minimal supersymmetric standard model (MSSM) and explore in detail which regions of parameter space are not excluded by null results from direct dark matter detection, assuming exclusive thermal production of neutralinos in the early universe, and illustrate the complementarity with current and future LHC searches for electroweak gauginos. We consider both bino-Higgsino and bino-wino "not-so-well-tempered" neutralinos, i.e. we include models where the lightest neutralino constitutes only part of the cosmological dark matter, with the consequent suppression of the constraints from direct and indirect dark matter searches.

  11. Drought-deciduous behavior reduces nutrient losses from temperate deciduous trees under severe drought.

    Science.gov (United States)

    Marchin, Renée; Zeng, Hainian; Hoffmann, William

    2010-08-01

    Nutrient resorption from senescing leaves is an important mechanism of nutrient conservation in temperate deciduous forests. Resorption, however, may be curtailed by climatic events that cause rapid leaf death, such as severe drought, which has been projected to double by the year 2100 in the eastern United States. During a record drought in the southeastern US, we studied 18 common temperate winter-deciduous trees and shrubs to understand how extreme drought affects nutrient resorption of the macronutrients N, P, K, and Ca. Four species exhibited drought-induced leaf senescence and maintained higher leaf water potentials than the remaining 14 species (here called drought-evergreen species). This strategy prevented extensive leaf desiccation during the drought and successfully averted large nutrient losses caused by leaf desiccation. These four drought-deciduous species were also able to resorb N, P, and K from drought-senesced leaves, whereas drought-evergreen species did not resorb any nutrients from leaves lost to desiccation during the drought. For Oxydendrum arboreum, the species most severely affected by the drought, our results indicate that trees lost 50% more N and P due to desiccation than would have been lost from fall senescence alone. For all drought-deciduous species, resorption of N and P in fall-senesced leaves was highly proficient, whereas resorption was incomplete for drought-evergreen species. The lower seasonal nutrient losses of drought-deciduous species may give them a competitive advantage over drought-evergreen species in the years following the drought, thereby impacting species composition in temperate deciduous forests in the future.

  12. Seasonal in situ observations of glyoxal and methylglyoxal over the temperate oceans of the Southern Hemisphere

    Science.gov (United States)

    Lawson, S. J.; Selleck, P. W.; Galbally, I. E.; Keywood, M. D.; Harvey, M. J.; Lerot, C.; Helmig, D.; Ristovski, Z.

    2015-01-01

    The dicarbonyls glyoxal and methylglyoxal have been measured with 2,4-dinitrophenylhydrazine (2,4-DNPH) cartridges and high-performance liquid chromatography (HPLC), optimised for dicarbonyl detection, in clean marine air over the temperate Southern Hemisphere (SH) oceans. Measurements of a range of dicarbonyl precursors (volatile organic compounds, VOCs) were made in parallel. These are the first in situ measurements of glyoxal and methylglyoxal over the remote temperate oceans. Six 24 h samples were collected in summer (February-March) over the Chatham Rise in the south-west Pacific Ocean during the Surface Ocean Aerosol Production (SOAP) voyage in 2012, while 34 24 h samples were collected at Cape Grim Baseline Air Pollution Station in the late winter (August-September) of 2011. Average glyoxal mixing ratios in clean marine air were 7 ppt at Cape Grim and 23 ppt over Chatham Rise. Average methylglyoxal mixing ratios in clean marine air were 28 ppt at Cape Grim and 10 ppt over Chatham Rise. The mixing ratios of glyoxal at Cape Grim are the lowest observed over the remote oceans, while mixing ratios over Chatham Rise are in good agreement with other temperate and tropical observations, including concurrent Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations. Methylglyoxal mixing ratios at both sites are comparable to the only other marine methylglyoxal observations available over the tropical Northern Hemisphere (NH) ocean. Ratios of glyoxal : methylglyoxal > 1 over Chatham Rise but water absorption or the use of an inappropriate normalisation reference value in the retrieval algorithm. This study provides much-needed data to verify the presence of these short-lived gases over the remote ocean and provide further evidence of an as yet unidentified source of both glyoxal and also methylglyoxal over the remote oceans.

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

    Science.gov (United States)

    Zhao, Xia; Yang, Guang

    2017-01-01

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

  14. 33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Lobster Boat Race, Winter Harbor, ME. (a) Regulated area. The regulated area includes all waters of Winter...

  15. Modelling the occurrence of postflexion stages of a marine estuarine-dependent fish in temperate South African estuaries

    Directory of Open Access Journals (Sweden)

    Yanasivan Kisten

    2017-03-01

    Full Text Available The movement of postflexion larvae of marine estuarine-dependent species into estuaries is critical for the survival of fishes reliant on estuaries as nurseries. However, detailed studies focused on environmental variability experienced by postflexion larvae entering a range of estuary types under varying conditions are rare. This study assessed the in situ conditions (temperature, salinity and water clarity under which the southern African endemic fish Rhabdosargus holubi (Sparidae recruits into estuaries. Postflexion larvae were sampled in three biogeographic regions (cool temperate, warm temperate and subtropical boundary, which included three estuary types (permanently open estuaries (POEs, temporarily open/closed estuaries and estuarine lake systems on a seasonal basis, independent of each other. Rhabdosargus holubi larvae were more abundant in spring and summer, in POEs in the warm temperate region. Models predicted that higher larval occurrence in estuaries is a function of lower salinity (e.g. mesohaline zones of 5-17.9 salinity and lower water clarity (e.g. 0-0.2 Kd, light extinction coefficient, particularly for warm, temperate POEs. This re-emphasizes the importance of freshwater for optimal nursery functioning, which may be compromised by impoundments, abstraction and climate change in water-short countries like South Africa.

  16. Influence of climate change on the flowering of temperate fruit trees

    Science.gov (United States)

    Perez-Lopez, D.; Ruiz-Ramos, M.; Sánchez-Sánchez, E.; Centeno, A.; Prieto-Egido, I.; Lopez-de-la-Franca, N.

    2012-04-01

    It is well known that winter chilling is necessary for the flowering of temperate trees. The chilling requirement is a criterion for choosing a species or variety at a given location. Also chemistry products can be used for reducing the chilling-hours needs but make our production more expensive. This study first analysed the observed values of chilling hours for some representative agricultural locations in Spain for the last three decades and their projected changes under climate change scenarios. Usually the chilling is measured and calculated as chilling-hours, and different methods have been used to calculate them (e.g. Richarson et al., 1974 among others) according to the species considered. For our objective North Carolina method (Shaltout and Unrath, 1983) was applied for apples, Utah method (Richardson et al. 1974) for peach and grapevine and the approach used by De Melo-Abreu et al. (2004) for olive trees. The influence of climate change in temperate trees was studied by calculating projections of chilling-hours with climate data from Regional Climate Models (RCMs) at high resolution (25 km) from the European Project ENSEMBLES (http://www.ensembles-eu.org/). These projections will allow for analysing the modelled variations of chill-hours between 2nd half of 20C and 1st half of 21C at the study locations.

  17. Improved management of winter operations to limit subsurface contamination with degradable deicing chemicals in cold regions

    NARCIS (Netherlands)

    French, H.K.; Zee, van der S.E.A.T.M.

    2014-01-01

    This paper gives an overview of management considerations required for better control of deicing chemicals in the unsaturated zone at sites with winter maintenance operations in cold regions. Degradable organic deicing chemicals are the main focus. The importance of the heterogeneity of both the

  18. Greater sage-grouse winter habitat use on the eastern edge of their range

    Science.gov (United States)

    Christopher C. Swanson; Mark A. Rumble; Nicholas W. Kaczor; Robert W. Klaver; Katie M. Herman-Brunson; Jonathan A. Jenks; Kent C. Jensen

    2013-01-01

    Greater sage-grouse (Centrocercus urophasianus) at the western edge of the Dakotas occur in the transition zone between sagebrush and grassland communities. These mixed sagebrush (Artemisia sp.) and grasslands differ from those habitats that comprise the central portions of the sage-grouse range; yet, no information is available on winter habitat selection within this...

  19. Four-year measurement of methane flux over a temperate forest with a relaxed eddy accumulation method

    Science.gov (United States)

    Sakabe, A.; Kosugi, Y.; Ueyama, M.; Hamotani, K.; Takahashi, K.; Iwata, H.; Itoh, M.

    2013-12-01

    Forests are generally assumed to be an atmospheric methane (CH4) sink (Le Mer and Roger, 2001). However, under Asian monsoon climate, forests are subject to wide spatiotemporal range in soil water status, where forest soils often became water-saturated condition heterogeneously. In such warm and humid conditions, forests may act as a CH4 source and/or sink with considerable spatiotemporal variations. Micrometeorological methods such as eddy covariance (EC) method continuously measure spatially-representative flux at a canopy scale without artificial disturbance. In this study, we measured CH4 fluxes over a temperate forest during four-year period using a CH4 analyzer based on tunable diode laser spectroscopy detection with a relaxed eddy accumulation (REA) method (Hamotani et al., 1996, 2001). We revealed the amplitude and seasonal variations of canopy-scale CH4 fluxes. The REA method is the attractive alternative to the EC method to measure trace-gas flux because it allows the use of analyzers with an optimal integration time. We also conducted continuous chamber measurements on forest floor to reveal spatial variations in soil CH4 fluxes and its controlling processes. The observations were made in an evergreen coniferous forest in central Japan. The site has a warm temperate monsoon climate with wet summer. Some wetlands were located in riparian zones along streams within the flux footprint area. For the REA method, the sonic anemometer (SAT-550, Kaijo) was mounted on top of the 29-m-tall tower and air was sampled from just below the sonic anemometer to reservoirs according to the direction of vertical wind velocity (w). After accumulating air for 30 minutes, the air in the reservoirs was pulled into a CO2/H2O gas analyzer (LI-840, Li-Cor) and a CH4 analyzer (FMA-200, Los Gatos Research). Before entering the analyzers, the sampled air was dried using a gas dryer (PD-50 T-48; Perma Pure Inc.). The REA flux is obtained from the difference in the mean concentrations

  20. An Integrated Time-Temperature Approach for Predicting Mechanical Properties of Quenched and Tempered Steels

    OpenAIRE

    O'Connell, Corey James

    2014-01-01

    The purpose of this work was to develop a steel tempering model that is useful to the commercial heat treater. Most of the tempering models reported address isothermal conditions which are not typical of most heating methods used to perform the tempering heat treatment. In this work, a non-isothermal tempering model was developed based on the tempering response of four steel alloys. This tempering model employs the quantity resulting from the numerical integration of the time-temperature prof...

  1. The tempering quality evaluation of cocoa liquor during industrial ...

    African Journals Online (AJOL)

    The tempering quality evaluation of the crude cocoa liquor with average fat content 55.0 ± 0.3 % and an average acid value, 1.57 ± 0.34) has been established. The various parameters considered were recasting time (RT) and appearance (AP) of the tempered product on one hand and the flow (F) of the crude liquor on ...

  2. Mercury in wintering seabirds, an aggravating factor to winter wrecks?

    Science.gov (United States)

    Fort, Jérôme; Lacoue-Labarthe, Thomas; Nguyen, Hanh Linh; Boué, Amélie; Spitz, Jérôme; Bustamante, Paco

    2015-09-15

    Every year, thousands of seabirds are cast ashore and are found dead along the coasts of North America and Western Europe. These massive mortality events called 'winter wrecks' have generally been attributed to harsh climatic conditions and prolonged storms which affect bird energy balance and impact their body condition. Nevertheless, additional stress factors, such as contaminant body burden, could potentially cumulate to energy constraints and actively contribute to winter wrecks. However, the role played by these additional factors in seabird massive winter mortality has received little attention to date. In February/March 2014, an unprecedented seabird wreck occurred along the Atlantic French coasts during which > 43,000 seabirds were found dead. By analyzing mercury (Hg) concentrations in various tissues collected on stranded birds, we tested the hypothesis that Hg played a significant role in this mortality. More specifically, we aimed to (1) describe Hg contamination in wintering seabirds found along the French coasts in 2014, and (2) determine if Hg concentrations measured in some vital organs such as kidney and brain reached toxicity thresholds that could have led to deleterious effects and to an enhanced mortality. We found some of the highest Hg levels ever reported in Atlantic puffins, common guillemots, razorbills and kittiwakes. Measured concentrations ranged from 0.8 to 3.6 μg · g(-1) of dry weight in brain, 1.3 to 7.2 μg · g(-1) in muscle, 2.5 to 13.5 μg · g(-1) in kidney, 2.9 to 18.6 μg · g(-1) in blood and from 3.1 to 19.5 μg · g(-1) in liver. Hg concentrations in liver and brain were generally below the estimated acute toxicity levels. However, kidney concentrations were not different than those measured in the liver, and above levels associated to renal sub-lethal effects, suggesting a potential Hg poisoning. We concluded that although Hg was not directly responsible for the high observed mortality, it has been a major aggravating

  3. Spray mist cooling heat transfer in glass tempering process

    Science.gov (United States)

    Sozbir, Nedim; Yao, S. C.

    2017-05-01

    Energy saving is a very important issue in glass plants, especially in a glass tempering process, where very high velocity air jet impingement is applied during the cooling process of glass tempering. In fact, air compressor energy may be reduced by a spray cooling due to its high heat transfer capabilities. Presently, in this paper, both pure air and water mist spray cooling are investigated in the glass tempering process. The test results indicate that thin and low-cost tempered glass can be made by mist cooling without fracture. It is possible to find the optimal water flux and duration of mist application to achieve a desirable temperature distribution in the glass for deep penetration of the cooling front but without inducing cracking during the tempering. The use of mist cooling could give about 29 % air pressure reduction for 2-mm glass plate and 50 % reduction for both 3- and 4-mm glass plates.

  4. Quantifying Uncertainty in Estimation of Potential Recharge in Tropical and Temperate Catchments using a Crop Model and Microwave Remote Sensing

    Science.gov (United States)

    Krishnan Kutty, S.; Sekhar, M.; Ruiz, L.; Tomer, S. K.; Bandyopadhyay, S.; Buis, S.; Guerif, M.; Gascuel-odoux, C.

    2012-12-01

    -arid region of South India (AMBHAS research observatory), wherein the recharge occurs mainly during the crop growth period and Indian summer monsoon (June-November). The second catchment is in the temperate climate region of South-east of France (Avignon), wherein recharge occurs during the winter when crop growth is minimal. The effect of parameter uncertainty on the potential recharge and its uncertainty is compared in these contrasting catchments. References Martinez, J.J., Skaggs, T.H., van Genuchten, M. Th. and Candela, L. (2009). A root zone modelling approach to estimating groundwater recharge from irrigated areas. Journal of Hydrology, 367,138-149 Rushton, K. R. (2003). Groundwater Hydrology. Conceptual and computational models, John Wiley, 416 p. Sreelash, K., Sekhar, M., Ruiz, L., Tomer, S. K., Guérif, M., Buis, S., Durand, P., and Gascuel-Odoux, C. (2012). Parameter estimation of a two-horizon soil profile by combining crop canopy and surface soil moisture observations using GLUE, Journal of Hydrology, 456-457, pp.57-67.

  5. Divergent responses to spring and winter warming drive community level flowering trends.

    Science.gov (United States)

    Cook, Benjamin I; Wolkovich, Elizabeth M; Parmesan, Camille

    2012-06-05

    Analyses of datasets throughout the temperate midlatitude regions show a widespread tendency for species to advance their springtime phenology, consistent with warming trends over the past 20-50 y. Within these general trends toward earlier spring, however, are species that either have insignificant trends or have delayed their timing. Various explanations have been offered to explain this apparent nonresponsiveness to warming, including the influence of other abiotic cues (e.g., photoperiod) or reductions in fall/winter chilling (vernalization). Few studies, however, have explicitly attributed the historical trends of nonresponding species to any specific factor. Here, we analyzed long-term data on phenology and seasonal temperatures from 490 species on two continents and demonstrate that (i) apparent nonresponders are indeed responding to warming, but their responses to fall/winter and spring warming are opposite in sign and of similar magnitude; (ii) observed trends in first flowering date depend strongly on the magnitude of a given species' response to fall/winter vs. spring warming; and (iii) inclusion of fall/winter temperature cues strongly improves hindcast model predictions of long-term flowering trends compared with models with spring warming only. With a few notable exceptions, climate change research has focused on the overall mean trend toward phenological advance, minimizing discussion of apparently nonresponding species. Our results illuminate an understudied source of complexity in wild species responses and support the need for models incorporating diverse environmental cues to improve predictability of community level responses to anthropogenic climate change.

  6. Linking energetics and overwintering in temperate insects.

    Science.gov (United States)

    Sinclair, Brent J

    2015-12-01

    Overwintering insects cannot feed, and energy they take into winter must therefore fuel energy demands during autumn, overwintering, warm periods prior to resumption of development in spring, and subsequent activity. Insects primarily consume lipids during winter, but may also use carbohydrate and proteins as fuel. Because they are ectotherms, the metabolic rate of insects is temperature-dependent, and the curvilinear nature of the metabolic rate-temperature relationship means that warm temperatures are disproportionately important to overwinter energy use. This energy use may be reduced physiologically, by reducing the slope or elevation of the metabolic rate-temperature relationship, or because of threshold changes, such as metabolic suppression upon freezing. Insects may also choose microhabitats or life history stages that reduce the impact of overwinter energy drain. There is considerable capacity for overwinter energy drain to affect insect survival and performance both directly (via starvation) or indirectly (for example, through a trade-off with cryoprotection), but this has not been well-explored. Likewise, the impact of overwinter energy drain on growing-season performance is not well understood. I conclude that overwinter energetics provides a useful lens through which to link physiology and ecology and winter and summer in studies of insect responses to their environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Communicating Certainty About Nuclear Winter

    Science.gov (United States)

    Robock, A.

    2013-12-01

    I have been spending much of my time in the past several years trying to warn the world about the continuing danger of nuclear weapons, and that the solution is a rapid reduction in the nuclear arsenal. I feel that a scientist who discovers dangers to society has an ethical duty to issue a warning, even if the danger is so scary that it is hard for people to deal with. The debate about nuclear winter in the 1980s helped to end the nuclear arms race, but the planet still has enough nuclear weapons, even after reductions planned for 2017 under the New START treaty, to produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet. New research by myself, Brian Toon, Mike Mills, and colleagues over the past six years has found that a nuclear war between any two countries, such as India and Pakistan, using 50 atom bombs each of the size dropped on Hiroshima could produce climate change unprecedented in recorded human history, and a world food crisis because of the agricultural effects. This is much less than 1% of the current global arsenal. Communicating certainty - what we know for sure - has been much more effective than communicating uncertainty. The limited success I have had has come from persistence and serendipity. The first step was to do the science. We have published peer-reviewed articles in major journals, including Science, Nature, Proceedings of the National Academy of Sciences, Journal of Geophysical Research, Atmospheric Chemistry and Physics, Physics Today, and Climatic Change. But policymakers do not read these journals. Through fairly convoluted circumstances, which will be described in this talk, we were able to get papers published in Scientific American and the Bulletin of Atomic Scientists. I have also published several encyclopedia articles on the subject. As a Lead Author of Chapter 8 (Radiative Forcing) of the recently published Fifth Assessment

  8. Behavioural plasticity in wintering Mediterranean ospreys revealed by stable isotopes analyses and GPS tracking.

    Science.gov (United States)

    Monti, Flavio; Robert, Aloïs; Dominici, Jean-Marie; Sforzi, Andrea; Triay Bagur, Rafel; Muñoz Navarro, Antoni; Guillou, Gaël; Bentaleb, Ilham; Duriez, Olivier

    2015-04-01

    To infer wintering ecology in Mediterranean ospreys (Pandion haliaetus) we relied on a dual and complementary approach, using both GPS tracking and multi stable isotope tracer approaches. A control sample of feathers from 80 individuals (mostly chicks) was collected over a large latitudinal gradient (from Lapland to Africa) to assess the variability of carbon, nitrogen and sulphur stable isotope ratios between breeding sites and habitat types across the Western Palearctic. Then, C, N and S isotopic compositions from an experimental set of 18 Mediterranean adults were examined to infer wintering ground locations and habitat types used during the inter-breeding period. Additionally, 12 adult ospreys were fitted with GPS devices and tracked during migration and the wintering season. By combining the two techniques we evidenced a partial migratory population with 41.7% of tagged individuals being resident and 58.3% that actually migrated. Ospreys spent the winter at temperate latitudes and showed a high plasticity in habitat selection. They made use of marine bays, coastal lagoons/marshland and inland freshwater sites. Movements and home range areas were reduced during the season. Wintering grounds were largely spread over the coasts of different countries of the basin, rather than concentrated in one single area. Such behavioural plasticity in the choice of location and habitat type suggests the implementing of broad-scale approaches for the protection of important areas for ospreys in winter. To contribute at assuring a right level of conservation of the osprey populations in the Mediterranean basin, a harmonization of the management protocols of wetland sites among countries is necessary.

  9. Temperate Ice Depth-Sounding Radar

    Science.gov (United States)

    Jara-Olivares, V. A.; Player, K.; Rodriguez-Morales, F.; Gogineni, P.

    2008-12-01

    Glaciers in several parts of the world are reported to be retreating and thinning rapidly over the last decade. Radar instruments can be used to provide a wealth of information regarding the internal and basal conditions of large and small ice masses. These instruments typically operate in the VHF and UHF regions of the electromagnetic spectrum. For temperate-ice sounding, however, the high water content produces scattering and attenuation in propagating radar waves at VHF and UHF frequencies, which significantly reduce the penetration depths. Radars operating in the HF band are better suited for systematic surveys of the thickness and sub-glacial topography of temperate-ice regions. We are developing a dual-frequency Temperate-Ice-Depth Sounding Radar (TIDSoR) that can penetrate through water pockets, thus providing more accurate measurements of temperate ice properties such as thickness and basal conditions. The radar is a light-weight, low power consumption portable system for surface-based observations in mountainous terrain or aerial surveys. TIDSoR operates at two different center frequencies: 7.7 MHz and 14 MHz, with a maximum output peak power of 20 W. The transmit waveform is a digitally generated linear frequency-modulated chirp with 1 MHz bandwidth. The radar can be installed on aircrafts such as the CReSIS UAV [1], DCH-6 (Twin Otter), or P-3 Orion for aerial surveys, where it could be supported by the airplane power system. For surface based experiments, TIDSoR can operate in a backpack configuration powered by a compact battery system. The system can also be installed on a sled towed by a motorized vehicle, in which case the power supply can be replaced by a diesel generator. The radar consists of three functional blocks: the digital section, the radio-frequency (RF) section, and the antenna, and is designed to weigh less than 2 kg, excluding the power supply. The digital section generates the transmit waveforms as well as timing and control signals

  10. Moist temperate forest butterflies of western Bhutan

    Directory of Open Access Journals (Sweden)

    Arun P. Singh

    2016-03-01

    Full Text Available Random surveys were carried out in moist temperate forests (1,860–3,116 m around Bunakha Village and Dochula Pass, near Thimphu in western Bhutan, recording 65 species of butterflies.  Of these, 11 species, viz., Straightwing Blue Orthomiella pontis pontis Elwes, Slate Royal Maneca bhotea bhotea Moore, Dull Green Hairstreak Esakiozephyrus icana Moore, Yellow Woodbrown Lethe nicetas Hewitson, Small Silverfork Zophoessa jalaurida elwesi Moore, Scarce Labyrinth, Neope pulahina (Evans, Chumbi Wall Chonala masoni Elwes, Pale Hockeystick Sailer Neptis manasa manasa Moore and White Commodore Parasarpa dudu dudu Westwood, are restricted to the eastern Himalaya, northeastern India and Myanmar.  Two other species, Tawny Mime Chiasa agestor agestor (Gray and Himalayan Spotted Flat Celaenorrhinus munda Moore have been only rarely recorded from Bhutan and a few individuals of the rare Bhutan Glory Bhutanitis lidderdalei Atkinson were also recorded near Bunakha.  

  11. Study on tempering behaviour of AISI 410 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Gopa, E-mail: gopa_mjs@igcar.gov.in [Metallurgy & Materials Group, Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India); Das, C.R.; Albert, S.K.; Bhaduri, A.K.; Thomas Paul, V. [Metallurgy & Materials Group, Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India); Panneerselvam, G. [Chemistry Group, Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India); Dasgupta, Arup [Metallurgy & Materials Group, Indira Gandhi Center for Atomic Research, Kalpakkam 603102 (India)

    2015-02-15

    Martensitic stainless steels find extensive applications due to their optimum combination of strength, hardness and wear-resistance in tempered condition. However, this class of steels is susceptible to embrittlement during tempering if it is carried out in a specific temperature range resulting in significant reduction in toughness. Embrittlement of as-normalised AISI 410 martensitic stainless steel, subjected to tempering treatment in the temperature range of 673–923 K was studied using Charpy impact tests followed by metallurgical investigations using field emission scanning electron and transmission electron microscopes. Carbides precipitated during tempering were extracted by electrochemical dissolution of the matrix and identified by X-ray diffraction. Studies indicated that temper embrittlement is highest when the steel is tempered at 823 K. Mostly iron rich carbides are present in the steel subjected to tempering at low temperatures of around 723 K, whereas chromium rich carbides (M{sub 23}C{sub 6}) dominate precipitation at high temperature tempering. The range 773–823 K is the transition temperature range for the precipitates, with both Fe{sub 2}C and M{sub 23}C{sub 6} types of carbides coexisting in the material. The nucleation of Fe{sub 2}C within the martensite lath, during low temperature tempering, has a definite role in the embrittlement of this steel. Embrittlement is not observed at high temperature tempering because of precipitation of M{sub 23}C{sub 6} carbides, instead of Fe{sub 2}C, preferentially along the lath and prior austenite boundaries. Segregation of S and P, which is widely reported as one of the causes for temper embrittlement, could not be detected in the material even through Auger electron spectroscopy studies. - Highlights: • Tempering behaviour of AISI 410 steel is studied within 673–923 K temperature range. • Temperature regime of maximum embrittlement is identified as 773–848 K. • Results show that type of

  12. Forecasting cyanobacteria dominance in Canadian temperate lakes.

    Science.gov (United States)

    Persaud, Anurani D; Paterson, Andrew M; Dillon, Peter J; Winter, Jennifer G; Palmer, Michelle; Somers, Keith M

    2015-03-15

    Predictive models based on broad scale, spatial surveys typically identify nutrients and climate as the most important predictors of cyanobacteria abundance; however these models generally have low predictive power because at smaller geographic scales numerous other factors may be equally or more important. At the lake level, for example, the ability to forecast cyanobacteria dominance is of tremendous value to lake managers as they can use such models to communicate exposure risks associated with recreational and drinking water use, and possible exposure to algal toxins, in advance of bloom occurrence. We used detailed algal, limnological and meteorological data from two temperate lakes in south-central Ontario, Canada to determine the factors that are closely linked to cyanobacteria dominance, and to develop easy to use models to forecast cyanobacteria biovolume. For Brandy Lake (BL), the strongest and most parsimonious model for forecasting % cyanobacteria biovolume (% CB) included water column stability, hypolimnetic TP, and % cyanobacteria biovolume two weeks prior. For Three Mile Lake (TML), the best model for forecasting % CB included water column stability, hypolimnetic TP concentration, and 7-d mean wind speed. The models for forecasting % CB in BL and TML are fundamentally different in their lag periods (BL = lag 1 model and TML = lag 2 model) and in some predictor variables despite the close proximity of the study lakes. We speculate that three main factors (nutrient concentrations, water transparency and lake morphometry) may have contributed to differences in the models developed, and may account for variation observed in models derived from large spatial surveys. Our results illustrate that while forecast models can be developed to determine when cyanobacteria will dominate within two temperate lakes, the models require detailed, lake-specific calibration to be effective as risk-management tools. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Phosphorous dynamics in a temperate intertidal estuary

    Science.gov (United States)

    Lillebø, A. I.; Neto, J. M.; Flindt, M. R.; Marques, J. C.; Pardal, M. A.

    2004-09-01

    Conservation and management of aquatic systems require detailed information of the processes that affect their functioning and development. The objectives of the present work were to describe the phosphorus dynamics during a complete tidal cycle and to quantify the relative contribution of the most common estuarine areas (e.g. seagrass beds, salt marshes, mud- and sand-flats without vegetation) to phosphorus net internal loading in a temperate intertidal estuary. Results show that phosphate efflux rates were higher during the first hours of tidal flood, and that phosphate concentrations were lowest at high tide. During tidal ebbing, ephemeral tide pools may cover a considerable percentage of the intertidal area. In these tide pools, water shallowness combined with enhanced temperatures stimulate the occurrence of high phosphate effluxes. The effluxes to the main water body during high tide contributed 57% of dissolved inorganic phosphorus and efflux during low tide contributed 43% to the net internal loading. Calculations of the phosphate net effluxes (kg P) indicate a strong contribution of the bare bottom mud-flats to the whole system internal phosphate loading, especially during the warmer periods. As a consequence of eutrophication, perennial benthic macrophytes are commonly replaced by fast-growing epiphytic macroalgae. Calculations showed that for a hypothetical intertidal estuary in a temperate region, management programs considering an eventual re-colonization of mud-flats by seagrasses or salt marsh plants may reduce the P-efflux by 13-16 kg ha -1. For example, in the small Mondego estuary, eutrophication has contributed to a reduction of the Zostera noltii meadows, leading to an increase in 190 kg of phosphorus net internal loading.

  14. Forage plants of an Arctic-nesting herbivore show larger warming response in breeding than wintering grounds, potentially disrupting migration phenology.

    Science.gov (United States)

    Lameris, Thomas K; Jochems, Femke; van der Graaf, Alexandra J; Andersson, Mattias; Limpens, Juul; Nolet, Bart A

    2017-04-01

    During spring migration, herbivorous waterfowl breeding in the Arctic depend on peaks in the supply of nitrogen-rich forage plants, following a "green wave" of grass growth along their flyway to fuel migration and reproduction. The effects of climate warming on forage plant growth are expected to be larger at the Arctic breeding grounds than in temperate wintering grounds, potentially disrupting this green wave and causing waterfowl to mistime their arrival on the breeding grounds. We studied the potential effect of climate warming on timing of food peaks along the migratory flyway of the Russian population of barnacle geese using a warming experiment with open-top chambers. We measured the effect of 1.0-1.7°C experimental warming on forage plant biomass and nitrogen concentration at three sites along the migratory flyway (temperate wintering site, temperate spring stopover site, and Arctic breeding site) during 2 months for two consecutive years. We found that experimental warming increased biomass accumulation and sped up the decline in nitrogen concentration of forage plants at the Arctic breeding site but not at temperate wintering and stop-over sites. Increasing spring temperatures in the Arctic will thus shorten the food peak of nitrogen-rich forage at the breeding grounds. Our results further suggest an advance of the local food peak in the Arctic under 1-2°C climate warming, which will likely cause migrating geese to mistime their arrival at the breeding grounds, particularly considering the Arctic warms faster than the temperate regions. The combination of a shorter food peak and mistimed arrival is likely to decrease goose reproductive success under climate warming by reducing growth and survival of goslings after hatching.

  15. Winter therapy for the accelerators

    CERN Multimedia

    Corinne Pralavorio

    2016-01-01

    Hundreds of people are hard at work during the year-end technical stop as all the accelerators are undergoing maintenance, renovation and upgrade operations in parallel.   The new beam absorber on its way to Point 2 before being lowered into the LHC tunnel for installation. The accelerator teams didn’t waste any time before starting their annual winter rejuvenation programme over the winter. At the end of November, as the LHC ion run was beginning, work got under way on the PS Booster, where operation had already stopped. On 14 December, once the whole complex had been shut down, the technical teams turned their attention to the other injectors and the LHC. The year-end technical stop (YETS) provides an opportunity to carry out maintenance work on equipment and repair any damage as well as to upgrade the machines for the upcoming runs. Numerous work projects are carried out simultaneously, so good coordination is crucial. Marzia Bernardini's team in the Enginee...

  16. Cryptococcus gattii infections on Vancouver Island, British Columbia, Canada: emergence of a tropical fungus in a temperate environment.

    Science.gov (United States)

    Fyfe, M; MacDougall, L; Romney, M; Starr, M; Pearce, M; Mak, S; Mithani, S; Kibsey, P

    2008-06-01

    Cryptococcus gattii causes disease among immunocompetent individuals in the tropics and subtropics. We document the appearance of C. gattii infections on Vancouver Island (VI), a temperate region, and discuss reasons for this emergence. Data on Cryptococcus hospitalizations for the calendar years 1995 through 2004 were reviewed. Viable historic isolates stored at the provincial public health laboratory between 1987 and 2000 were serotyped. Human cases were mapped by place of residence. Cryptococcosis among HIV negative individuals diagnosed on VI increased sharply after 1999. C. gattii was not detected in stored isolates prior to 1999. C. gattii cases lived in a specific biogeoclimatic zone on VI. Higher rates of illness were associated with exposure to the central region of VI. The emergence of C. gattii in a temperate region is unprecedented. Clinicians should consider C. gattii in the differential diagnosis of individuals who travelled to certain areas in British Columbia.

  17. Microbial colonization and degradation of polyethylene and biodegradable plastic bags in temperate fine-grained organic-rich marine sediments.

    Science.gov (United States)

    Nauendorf, Alice; Krause, Stefan; Bigalke, Nikolaus K; Gorb, Elena V; Gorb, Stanislav N; Haeckel, Matthias; Wahl, Martin; Treude, Tina

    2016-02-15

    To date, the longevity of plastic litter at the sea floor is poorly constrained. The present study compares colonization and biodegradation of plastic bags by aerobic and anaerobic benthic microbes in temperate fine-grained organic-rich marine sediments. Samples of polyethylene and biodegradable plastic carrier bags were incubated in natural oxic and anoxic sediments from Eckernförde Bay (Western Baltic Sea) for 98 days. Analyses included (1) microbial colonization rates on the bags, (2) examination of the surface structure, wettability, and chemistry, and (3) mass loss of the samples during incubation. On average, biodegradable plastic bags were colonized five times higher by aerobic and eight times higher by anaerobic microbes than polyethylene bags. Both types of bags showed no sign of biodegradation during this study. Therefore, marine sediment in temperate coastal zones may represent a long-term sink for plastic litter and also supposedly compostable material. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    OpenAIRE

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

    2017-01-01

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

  19. Uptake and resource allocation of ammonium and nitrate in temperate seagrasses Posidonia and Amphibolis.

    Science.gov (United States)

    Nayar, S; Collings, G J; Miller, D J; Bryars, S; Cheshire, A C

    2010-09-01

    Ecologically relevant estimates of seasonal variability in nitrogen uptake and allocation in two species of temperate seagrasses were obtained using in situ isotope-labelling approach. Significantly higher uptake rates of ammonium by leaves, roots and epiphytes of Amphibolis than Posidonia were observed. Overall, root uptake rates were lower than other components. Effect of season was not significant for leaves, roots or epiphytes of the two species. However, plankton uptake varied seasonally with higher rates in winter (0.98 mg N g(-1)D Wh(-1)). In contrast, nitrate uptake rates for various components were significantly affected by seasons. Uptake rates by plankton were highest ranging from 0.003 mg N g(-1)D Wh(-1) (summer, Amphibolis) to 0.69 mg N g(-1)DWh(-1) (winter, Posidonia). Uptake of nitrate by roots was negligible. Biotic uptake rates for nitrate were an order of magnitude slower than ammonium, demonstrating an affinity for ammonium over nitrate as a preferred inorganic nitrogen source. Adelaide coastal waters have lost over 5000 ha of seagrasses, much of this attributed to nutrient inputs from wastewater, industrial and stormwater. Managing these inputs into future requires better understanding of the fate of nutrients, particularly biological uptake. This study attempts to quantify uptake rates of nitrogen by seagrasses. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Effects of land use/land cover on diurnal temperature range in the temperate grassland region of China.

    Science.gov (United States)

    Shen, Xiangjin; Liu, Binhui; Lu, Xianguo

    2017-01-01

    As a fragile ecological zone, the temperate grassland region of China has experienced dramatic land use/land cover (LULC) changes due to human disturbances. So far, the impacts of LULC change on climate especially the diurnal temperature range (DTR) in this region are still not well understood. Based on the OMR (observation minus reanalysis) method, this study investigated the effects of LULC on DTR in the temperate grassland region of China. Considering the possible uncertainty of the results due to spatial resolution of the reanalysis dataset, two reanalysis datasets with different spatial resolutions were utilized. Results showed that LULC generally contributed to the decline of DTR in the temperate grassland region of China during 1980 to 2005. Due to different warming effects on monthly maximum temperature (Tmax) and minimum temperature (Tmin), grassland and forest tend to slightly decrease monthly DTR (approximately -0.053 to -0.050°C/decade and approximately -0.059 to -0.055°C/decade, respectively), while bare land has a slightly positive effect on DTR (approximately 0.018-0.021°C/decade). By contrast, cropland and urban tend to slightly decrease Tmax, obviously increase Tmin and thus result in a rapid decline of DTR (approximately -0.556 to -0.503°C/decade and approximately -0.617 to -0.612°C/decade, respectively). In the temperate grassland region of China, grassland vegetation changes due to human disturbances can have some effects on DTR mainly by changing the Tmax. Conversion from grassland to cropland could decrease the DTR by slowing down the increase of Tmax. But the conversion from grassland to bare land, as well as the reduction of grassland vegetation cover will increase Tmax, and consequently the DTR. The results suggest that grassland degradation is likely to result in daylight warming and increased DTR in the temperate grassland region of China. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Global analysis of threat status reveals higher extinction risk in tropical than in temperate bird sister species

    Directory of Open Access Journals (Sweden)

    Reif Jiří

    2016-06-01

    Full Text Available Given increasing pressures upon biodiversity, identification of species’ traits related to elevated extinction risk is useful for more efficient allocation of limited resources for nature conservation. Despite its need, such a global analysis was lacking in the case of birds. Therefore, we performed this exercise for avian sister species using information about their global extinction risk from IUCN Red List. We focused on 113 pairs of sister species, each containing a threatened and an unthreatened species to factor out the effects of common evolutionary history on the revealed relationship. We collected data on five traits with expected relationships to species’ extinction risk based on previous studies performed at regional or national levels: breeding habitat (recognizing forest, grassland, wetland and oceanic species, latitudinal range position (temperate and tropics species, migration strategy (migratory and resident species, diet (carnivorous, insectivorous, herbivorous and omnivorous species and body mass. We related the extinction risk using IUCN threat level categories to species’ traits using generalised linear mixed effects models expecting lower risk for forest, temperate, omnivorous and smaller-bodied species. Our expectation was confirmed only in the case of latitudinal range position, as we revealed higher threat level for tropical than for temperate species. This relationship was robust to different methods of threat level expression and cannot be explained by a simple association of high bird species richness with the tropical zone. Instead, it seems that tropical species are more threatened because of their intrinsic characteristics such as slow life histories, adaptations to stable environments and small geographic ranges. These characteristics are obviously disadvantageous in conditions of current human-induced environmental perturbations. Moreover, given the absence of habitat effects, our study indicates that such

  2. Ductile-Brittle Transition Behavior in Tempered Martensitic SA508 Gr. 4N Ni-Mo-Cr Low Alloy Steels for Reactor Pressure Vessels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ki Hyoung; Wee, Dang Moon [KAIST, Daejeon (Korea, Republic of); Kim, Min Chul; Lee, Bong Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    Reactor pressure vessels (RPVs) operate under severe conditions of elevated temperature, high pressure, and irradiation. Therefore, a combination of sufficient strength, toughness, good weldability, and high irradiation resistance are required for RPV materials. SA508 Gr.4N low alloy steel, which has higher Ni and Cr contents than those of commercial RPV steel, Gr.3 steel, is considered as a candidate material due to its excellent mechanical properties from tempered martensitic microstructure. The ferritic steels such as Gr.3 and Gr.4N low alloy steels reveal a ductile-brittle transition and large scatters in the fracture toughness within a small temperature range. Recently, there are some observations of the steeper transition behavior in the tempered martensitic steels, such as Eurofer97 than the transition behavior of commercial RPV steels. It was also reported that the fracture toughness increased discontinuously when the phase fraction of the tempered martensite was over a critical fraction in the heat affected zones of SA508 Gr.3. Therefore, it may be necessary to evaluate the changes of transition behavior with a microstructure for the tempered martensitic SA508 Gr.4N low alloy steel. In this study, the fracture toughness for SA508 Gr.4N low alloy steels was evaluated from a view point of the temperature dependency with phase fraction of tempered martensite controlled by cooling rate. Additionally, a possible modification of the fracture toughness master curve was proposed and discussed

  3. Stress relaxation in tempered glass caused by heat soak testing

    DEFF Research Database (Denmark)

    Schneider, Jens; Hilcken, Jonas; Aronen, Antti

    2016-01-01

    of commercial soda-lime-silica glass, it causes stress relaxation in tempered glass and the fracture pattern of the glass changes accordingly, especially thin glasses are affected. Based on the Tool-Narayanaswamy-Model, this paper comprises the theoretical background of the stress......Heat soak testing of tempered glass is a thermal process required after the tempering process itself to bring glasses of commercial soda-lime-silica-glass to failure that are contaminated with nickel sulphide inclusions, diameter 50 mm to 500 mm typically. Thus, the tests avoid a so...

  4. Winter color polymorphisms identify global hot spots for evolutionary rescue from climate change.

    Science.gov (United States)

    Mills, L Scott; Bragina, Eugenia V; Kumar, Alexander V; Zimova, Marketa; Lafferty, Diana J R; Feltner, Jennifer; Davis, Brandon M; Hackländer, Klaus; Alves, Paulo C; Good, Jeffrey M; Melo-Ferreira, José; Dietz, Andreas; Abramov, Alexei V; Lopatina, Natalia; Fay, Kairsten

    2018-02-15

    Maintenance of biodiversity in a rapidly changing climate will depend on the efficacy of evolutionary rescue, whereby population declines due to abrupt environmental change are reversed by shifts in genetically driven adaptive traits. However, a lack of traits known to be under direct selection by anthropogenic climate change has limited the incorporation of evolutionary processes into global conservation efforts. In 21 vertebrate species, some individuals undergo a seasonal color molt from summer brown to winter white as camouflage against snow, while other individuals remain brown. Seasonal snow duration is decreasing globally, and fitness is lower for winter white animals on snowless backgrounds. Based on 2713 georeferenced samples of known winter coat color-from eight species across trophic levels-we identify environmentally driven clinal gradients in winter coat color, including polymorphic zones where winter brown and white morphs co-occur. These polymorphic zones, underrepresented by existing global protected area networks, indicate hot spots for evolutionary rescue in a changing climate. Copyright © 2018, American Association for the Advancement of Science.

  5. Foraging flight distances of wintering ducks and geese: a review

    Directory of Open Access Journals (Sweden)

    William P. Johnson

    2014-12-01

    Full Text Available The distance covered by foraging animals, especially those that radiate from a central area when foraging, may affect ecosystem, community, and population dynamics, and has conservation and landscape planning implications for multiple taxa, including migratory waterfowl. Migrating and wintering waterfowl make regular foraging flights between roosting and feeding areas that can greatly impact energetic resources within the foraging zone near roost sites. We reviewed published studies and gray literature for one-way foraging flight distances (FFDs of migrating and wintering dabbling ducks and geese. Thirty reviewed studies reported FFDs and several reported values for multiple species or locations. We obtained FFD values for migration (n = 7 and winter (n = 70. We evaluated the effects of body mass, guild, i.e., dabbling duck or goose, and location, i.e., Nearctic or Palearctic, on FFDs. We used the second-order Akaike's Information Criterion for model selection. We found support for effects of location and guild on FFDs. FFDs of waterfowl wintering in the Nearctic (7.4 ± 6.7 km, mean ± SD; n = 39 values were longer than in the Palearctic (4.2 ± 3.2 km; n = 31 values. The FFDs of geese (7.8 ± 7.2 km, mean ± SD; n = 24 values were longer than FFDs of dabbling ducks (5.1 ± 4.4 km, mean ± SD; n = 46 values. We found mixed evidence that distance flown from the roost changed, i.e., increased or decreased, seasonally. Our results can be used to refine estimates of energetic carrying capacity around roosts and in biological and landscape planning efforts.

  6. Physiological Responses to Firefighting in Extreme Temperatures Do Not Compare to Firefighting in Temperate Conditions

    Directory of Open Access Journals (Sweden)

    Stephanie Windisch

    2017-08-01

    Full Text Available Purpose: The aim of this study was to examine physiological responses to two different simulated firefighting exercises: a firefighting exercise with flashovers, smoke, poor visibility and extreme temperatures (300° in a burning container and a standard firefighting exercise in temperate conditions. Furthermore, a second purpose of the study was to find out if the contribution of strength and endurance capacities to firefighting performance changes when the demands of the firefighting exercise change.Methods: Sixteen professional firefighters performed a maximum treadmill test, strength testing, a standard simulated firefighting exercise (SFE without heat and flashovers and a firefighting exercise with a simulation of the flashover phenomenon in a burning container (FOT. The treadmill testing was used to determine peak oxygen uptake (VO2peak, ventilatory threshold (VT1 and respiratory compensation point (RCP. Three intensity zones were identified according to heart rate (HR values corresponding to VT1 and RCP: zone 1–HR below VT1, zone 2-HR between VT1 and RCP, zone 3–HR above RCP. Firefighting performance was determined by a simple time-strain-air depletion model (TSA taking the sum of z-transformed parameters of time to finish the exercise, strain in terms of mean heart rate, and air depletion from the breathing apparatus. Correlations were then established between TSA based firefighting performance parameters and fitness variables representing strength and endurance.Results: HR was significantly lower during SFE (79.9 ± 6.9%HRmax compared to FOT (85.4 ± 5.2%HRmax. During SFE subjects spent 24.6 ± 30.2% of time in zone 1, 65.8 ± 28.1% in zone 2 and 9.7 ± 16.6% in zone 3. During FOT subjects spent 16.3 ± 12.8% in zone 1, 50.4 ± 13.2% in zone 2 and 33.3 ± 16.6% in zone 3. Out of all correlations, relative VO2peak showed the highest relation to mean HR during SFE (−0.593 as well as FOT (−0.693.Conclusions: Endurance in terms of

  7. Reanalysis of water and carbon cycle models at a critical zone observatory

    Science.gov (United States)

    The Susquehanna Shale Hills Critical Zone Observatory (SSHCZO) is a forested, hill-slope catchment located in the temperate-climate of central Pennsylvania with an extensive network of ground-based instrumentation for model testing and development. In this paper we discuss the use of multi-state fi...

  8. Drilling in tempered glass – modelling and experiments

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik

    The present paper reports experimentally and numerically obtained results for the process of drilling in tempered glass. The experimental results are drilling depths on the edge in 19mm tempered glass with a known residual stress state measured by a scattered light polariscope. The experiments have...... been modelled using a state-of-the-art model and compared with satisfying result to the performed experiments. The numerical model has been used for a parametric study, investigating the redistribution of residual stresses during the process of drilling. This is done for investigating the possibility...... of applying forces in such holes and thereby being able to mechanically assemble tempered glass without the need of drilling holes before the tempering process. The paper is the result of currently ongoing research and the results should be treated as so....

  9. Methane emissions and uptake in temperate and tropical forest trees on free-draining soils.

    Science.gov (United States)

    Welch, Bertie; Sayer, Emma; Siegenthaler, Andy; Gauci, Vincent

    2016-04-01

    Forests play an important role in the exchange of radiatively important gases with the atmosphere. Previous studies have shown that in both temperate and tropical wetland forests tree stems are significant sources of methane (CH4), yet little is known about trace greenhouse gas dynamics in free-draining soils that dominate global forested areas. We examined trace gas (CH4 and N2O) fluxes from both soils and tree stems in a lowland tropical forest on free-draining soils in Panama, Central America and from a deciduous woodland in the United Kingdom. The tropical field site was a long-term experimental litter manipulation experiment in the Barro Colorado Nature Monument within the Panama Canal Zone, fluxes were sampled over the dry to wet season transition (March-August) in 2014 and November 2015. Temperate fluxes were sampled at Wytham Woods, Oxfordshire, over 12 months from February 2015 to January 2016. Tree stem samples were collected via syringe from temporary chambers strapped to the trees (as per Siegenthaler et al. (2015)) and the soil fluxes were sampled from permanently installed collars inserted to a 3cm depth. We found that seasonality (precipitation) is a significant driver of changing soil exchange from methane uptake to emission at the Panama sites. Experimental changes to litter quantity only become significant when coupled with seasonal change. Seasonal variability is an important control of the fluxes at out temperate forest site with changes in temperature and soil water content leading to changes in soil and tree stem trace gas fluxes from Wytham Woods. Siegenthaler, A., Welch, B., Pangala, S. R., Peacock, M., and Gauci, V.: Technical Note: Semi-rigid chambers for methane gas flux measurements on tree-stems, Biogeosciences Discuss., 12, 16019-16048, doi:10.5194/bgd-12-16019-2015, 2015.

  10. Mapping of QTL for the seed storage proteins cruciferin and napin in a winter oilseed rape doubled haploid population and their inheritance in relation to other seed traits.

    Science.gov (United States)

    Schatzki, Jörg; Ecke, Wolfgang; Becker, Heiko C; Möllers, Christian

    2014-05-01

    Cruciferin (cru) and napin (nap) were negatively correlated and the cru/nap ratio was closely negative correlated with glucosinolate content indicating a link between the two biosynthetic pathways. Canola-type oilseed rape (Brassica napus L.) is an economically important oilseed crop in temperate zones. Apart from the oil, the canola protein shows potential as a value-added food and nutraceutical ingredient. The two major storage protein groups occurring in oilseed rape are the 2 S napins and 12 S cruciferins. The aim of the present study was to analyse the genetic variation and the inheritance of napin and cruciferin content of the seed protein in the winter oilseed rape doubled haploid population Express 617 × R53 and to determine correlations to other seed traits. Seed samples were obtained from field experiments performed in 2 years at two locations with two replicates in Germany. A previously developed molecular marker map of the DH population was used to map quantitative trait loci (QTL) of the relevant traits. The results indicated highly significant effects of the year and the genotype on napin and cruciferin content as well as on the ratio of cruciferin to napin. Heritabilities were comparatively high with 0.79 for napin and 0.77 for cruciferin. Napin and cruciferin showed a significant negative correlation (-0.36**) and a close negative correlation of the cru/nap ratio to glucosinolate content was observed (-0.81**). Three QTL for napin and two QTL for cruciferin were detected, together explaining 47 and 35 % of the phenotypic variance. A major QTL for glucosinolate content was detected on linkage group N19 whose confidence interval overlapped with QTL for napin and cruciferin content. Results indicate a relationship between seed protein composition and glucosinolate content.

  11. Error and efficiency of simulated tempering simulations.

    Science.gov (United States)

    Rosta, Edina; Hummer, Gerhard

    2010-01-21

    We derive simple analytical expressions for the error and computational efficiency of simulated tempering (ST) simulations. The theory applies to the important case of systems whose dynamics at long times is dominated by the slow interconversion between two metastable states. An extension to the multistate case is described. We show that the relative gain in efficiency of ST simulations over regular molecular dynamics (MD) or Monte Carlo (MC) simulations is given by the ratio of their reactive fluxes, i.e., the number of transitions between the two states summed over all ST temperatures divided by the number of transitions at the single temperature of the MD or MC simulation. This relation for the efficiency is derived for the limit in which changes in the ST temperature are fast compared to the two-state transitions. In this limit, ST is most efficient. Our expression for the maximum efficiency gain of ST simulations is essentially identical to the corresponding expression derived by us for replica exchange MD and MC simulations [E. Rosta and G. Hummer, J. Chem. Phys. 131, 165102 (2009)] on a different route. We find quantitative agreement between predicted and observed efficiency gains in a test against ST and replica exchange MC simulations of a two-dimensional Ising model. Based on the efficiency formula, we provide recommendations for the optimal choice of ST simulation parameters, in particular, the range and number of temperatures, and the frequency of attempted temperature changes.

  12. The tempered polymerization of human neuroserpin.

    Directory of Open Access Journals (Sweden)

    Rosina Noto

    Full Text Available Neuroserpin, a member of the serpin protein superfamily, is an inhibitor of proteolytic activity that is involved in pathologies such as ischemia, Alzheimer's disease, and Familial Encephalopathy with Neuroserpin Inclusion Bodies (FENIB. The latter belongs to a class of conformational diseases, known as serpinopathies, which are related to the aberrant polymerization of serpin mutants. Neuroserpin is known to polymerize, even in its wild type form, under thermal stress. Here, we study the mechanism of neuroserpin polymerization over a wide range of temperatures by different techniques. Our experiments show how the onset of polymerization is dependent on the formation of an intermediate monomeric conformer, which then associates with a native monomer to yield a dimeric species. After the formation of small polymers, the aggregation proceeds via monomer addition as well as polymer-polymer association. No further secondary mechanism takes place up to very high temperatures, thus resulting in the formation of neuroserpin linear polymeric chains. Most interesting, the overall aggregation is tuned by the co-occurrence of monomer inactivation (i.e. the formation of latent neuroserpin and by a mechanism of fragmentation. The polymerization kinetics exhibit a unique modulation of the average mass and size of polymers, which might suggest synchronization among the different processes involved. Thus, fragmentation would control and temper the aggregation process, instead of enhancing it, as typically observed (e.g. for amyloid fibrillation.

  13. Crenarchaeota and Euryarchaeota in temperate estuarine sediments.

    Science.gov (United States)

    Abreu, C; Jurgens, G; De Marco, P; Saano, A; Bordalo, A A

    2001-05-01

    Application of molecular techniques to ecological studies has unveiled a wide diversity of micro-organisms in natural communities, previously unknown to microbial ecologists. New lineages of Archaea were retrieved from several non-extreme environments, showing that these micro-organisms are present in a large variety of ecosystems. The aim was therefore to assess the presence and diversity of Archaea in the sediments of the river Douro estuary (Portugal), relating the results obtained to ecological data. Total DNA was extracted from sediment samples obtained from an estuary deprived of vegetation, amplified by PCR and the resulting DNA fragments cloned. The archaeal origin of the cloned inserts was checked by Southern blot, dot blot or colony blot hybridization. Recombinant plasmids were further analysed by restriction with AvaII and selected for sequencing. Phylogenetic analyses of 14 sequences revealed the presence of members of the domain Archaea. Most of the sequences could be assigned to the kingdom Crenarchaeota. Most of these sequences were closely related to those obtained from non-extreme Crenarchaeota members previously retrieved from diverse ecosystems, such as freshwater and marine environments. The presence of archaeal 16S rDNA sequences in temperate estuarine sediments emerges as a valuable contribution to the understanding of the complexity of the ecosystem.

  14. Influence of tempering temperature on mechanical properties of cast steels

    Directory of Open Access Journals (Sweden)

    G. Golański

    2008-12-01

    Full Text Available The paper presents results of research on the influence of tempering temperature on structure and mechanical properties of bainite hardened cast steel: G21CrMoV4 – 6 (L21HMF and G17CrMoV5 – 10 (L17HMF. Investigated cast steels were taken out from internal frames of steam turbines serviced for long time at elevated temperatures. Tempering of the investigated cast steel was carried out within the temperature range of 690 ÷ 730 C (G21CrMoV4 – 6 and 700 ÷ 740 C (G17CrMoV5 – 10. After tempering the cast steels were characterized by a structure of tempered lower bainite with numerous precipitations of carbides. Performed research of mechanical properties has shown that high temperatures of tempering of bainitic structure do not cause decrease of mechanical properties beneath the required minimum.oo It has also been proved that high-temperature tempering (>720 oC ensures high impact energy at the 20% decrease of mechanical properties.

  15. Dung beetle communities: a neotropical-north temperate comparison.

    Science.gov (United States)

    Radtke, Meghan G; Fonseca, Cláudio R V da; Williamson, G Bruce

    2010-01-01

    Dung beetle communities have been compared across north temperate latitudes. Tropical dung beetle communities appear to be more diverse based on studies using different methodologies. Here, we present results from a standardized sampling protocol used to compare dung beetle communities across five neotropical forests in Brazil and Ecuador and two warm, north temperate forests in Mississippi and Louisiana. Species richness in the tropical forests was three to seven times higher than the temperate forests, as would be expected by studies of other taxa across tropical and temperate latitudes. Average body size in the temperate forests was larger than the tropical forests, as predicted by Bergmann's rule. Dung beetle abundance and volume per trap-day were generally higher in Ecuador than Brazil, and higher in Mississippi than Louisiana, but there were no tropical-temperate differences. Species rank-abundance curves were similar within countries and between countries. Rank-volume distributions indicated a smaller range of beetle body sizes in Ecuador versus Brazil or the USA. Community similarity was high within countries and low between countries. Community differences between Brazil and Ecuador sites may be explained by differences in productivity based on geological age of the soils.

  16. Evolution of Diurnal Asymmetry of Surface Temperature over Different Climatic Zones

    Science.gov (United States)

    Rajendran, V.; C T, D.; Chakravorty, A.; AghaKouchak, A.

    2016-12-01

    The increase in drought, flood, diseases, crop failure etc. in the recent past has created an alarm amongst the researchers. One of the main reasons behind the intensification of these environmental hazards is the recent revelation of climate change, which is generally attributed to the human induced global warming, represented by an increase in global mean temperature. However, in order to formulate policies to mitigate and prevent the threats due to global warming, its key driving factors should be analysed at high spatial and temporal resolution. Diurnal Temperature Range (DTR) is one of the indicators of global warming. The study of the evolution of the DTR is crucial, since it affects agriculture, health, ecosystems, transport, etc. Recent studies reveal that diurnal asymmetry has decreased globally, whereas a few regional studies report a contradictory pattern and attributed them to localized feedback processes. However, an evident conclusion cannot be made using the linear trend approaches employed in the past studies and the evolution of diurnal asymmetry should be investigated using non-linear trend approach for better perception. Hence, the regional evolution of DTR trend has been analysed using the spatially-temporally Multidimensional Ensemble Empirical Mode Decomposition (MEEMD) method over India and observed a positive trend in over-all mean of DTR, while its rate of increase has declined in the recent decades. Further, the grids showing negative trend in DTR is observed in arid deserts and warm-temperate grasslands and positive trend over the west coast and sub-tropical forest in the North-East. This transition predominantly began from the west coast and is stretched with an increase in magnitude. These changes are more pronounced during winter and post-monsoon seasons, especially in the arid desert and warm-temperate grasslands, where the rate of increase in minimum temperature is higher than that of the maximum temperature. These analyses suggest

  17. Could behaviour and not physiological thermal tolerance determine winter survival of aphids in cereal fields?

    Science.gov (United States)

    Alford, Lucy; Andrade, Thiago Oliveira; Georges, Romain; Burel, Françoise; van Baaren, Joan

    2014-01-01

    Traits of physiological thermotolerance are commonly measured in the laboratory as predictors of the field success of ectotherms at unfavourable temperatures (e.g. during harsh winters, heatwaves, or under conditions of predicted global warming). Due to being more complicated to measure, behavioural thermoregulation is less commonly studied, although both physiology and behaviour interact to explain the survival of ectotherms. The aphids Metopolophium dirhodum, Rhopalosiphum padi and Sitobion avenae are commercially important pests of temperate cereal crops. Although coexisting, these species markedly differ in winter success, with R. padi being the most abundant species during cold winters, followed by S. avenae and lastly M. dirhodum. To better understand the thermal physiology and behavioural factors contributing to differential winter success, the lethal temperature (physiological thermotolerance) and the behaviour of aphids in a declining temperature regime (behavioural thermotolerance) of these three species were investigated. Physiological thermotolerance significantly differed between the three species, with R. padi consistently the least cold tolerant and S. avenae the most cold tolerant. However, although the least cold tolerant of the study species, significantly more R. padi remained attached to the host plant at extreme sub-zero temperatures than S. avenae and M. dirhodum. Given the success of anholocyclic R. padi in harsh winters compared to its anholocyclic counterparts, this study illustrates that behavioural differences could be more important than physiological thermotolerance in explaining resistance to extreme temperatures. Furthermore it highlights that there is a danger to studying physiological thermotolerance in isolation when ascertaining risks of ectotherm invasions, the establishment potential of exotic species in glasshouses, or predicting species impacts under climate change scenarios.

  18. Could behaviour and not physiological thermal tolerance determine winter survival of aphids in cereal fields?

    Directory of Open Access Journals (Sweden)

    Lucy Alford

    Full Text Available Traits of physiological thermotolerance are commonly measured in the laboratory as predictors of the field success of ectotherms at unfavourable temperatures (e.g. during harsh winters, heatwaves, or under conditions of predicted global warming. Due to being more complicated to measure, behavioural thermoregulation is less commonly studied, although both physiology and behaviour interact to explain the survival of ectotherms. The aphids Metopolophium dirhodum, Rhopalosiphum padi and Sitobion avenae are commercially important pests of temperate cereal crops. Although coexisting, these species markedly differ in winter success, with R. padi being the most abundant species during cold winters, followed by S. avenae and lastly M. dirhodum. To better understand the thermal physiology and behavioural factors contributing to differential winter success, the lethal temperature (physiological thermotolerance and the behaviour of aphids in a declining temperature regime (behavioural thermotolerance of these three species were investigated. Physiological thermotolerance significantly differed between the three species, with R. padi consistently the least cold tolerant and S. avenae the most cold tolerant. However, although the least cold tolerant of the study species, significantly more R. padi remained attached to the host plant at extreme sub-zero temperatures than S. avenae and M. dirhodum. Given the success of anholocyclic R. padi in harsh winters compared to its anholocyclic counterparts, this study illustrates that behavioural differences could be more important than physiological thermotolerance in explaining resistance to extreme temperatures. Furthermore it highlights that there is a danger to studying physiological thermotolerance in isolation when ascertaining risks of ectotherm invasions, the establishment potential of exotic species in glasshouses, or predicting species impacts under climate change scenarios.

  19. Seasonal cues induce phenotypic plasticity of Drosophila suzukii to enhance winter survival.

    Science.gov (United States)

    Shearer, Peter W; West, Jessica D; Walton, Vaughn M; Brown, Preston H; Svetec, Nicolas; Chiu, Joanna C

    2016-03-22

    As global climate change and exponential human population growth intensifies pressure on agricultural systems, the need to effectively manage invasive insect pests is becoming increasingly important to global food security. Drosophila suzukii is an invasive pest that drastically expanded its global range in a very short time since 2008, spreading to most areas in North America and many countries in Europe and South America. Preliminary ecological modeling predicted a more restricted distribution and, for this reason, the invasion of D. suzukii to northern temperate regions is especially unexpected. Investigating D. suzukii phenology and seasonal adaptations can lead to a better understanding of the mechanisms through which insects express phenotypic plasticity, which likely enables invasive species to successfully colonize a wide range of environments. We describe seasonal phenotypic plasticity in field populations of D. suzukii. Specifically, we observed a trend of higher proportions of flies with the winter morph phenotype, characterized by darker pigmentation and longer wing length, as summer progresses to winter. A laboratory-simulated winter photoperiod and temperature (12:12 L:D and 10 °C) were sufficient to induce the winter morph phenotype in D. suzukii. This winter morph is associated with increased survival at 1 °C when compared to the summer morph, thus explaining the ability of D. suzukii to survive cold winters. We then used RNA sequencing to identify gene expression differences underlying seasonal differences in D. suzukii physiology. Winter morph gene expression is consistent with known mechanisms of cold-hardening such as adjustments to ion transport and up-regulation of carbohydrate metabolism. In addition, transcripts involved in oogenesis and DNA replication were down-regulated in the winter morph, providing the first molecular evidence of a reproductive diapause in D. suzukii. To date, D. suzukii cold resistance studies suggest that this

  20. Photosynthetic capacity of red spruce during winter

    Science.gov (United States)

    P.G. Schaberg; J.B. Shane; P.F. Cali; J.R. Donnelly; G.R. Strimbeck

    1998-01-01

    We measured the photosynthetic capacity (Pmax) of plantation-grown red spruce (Picea rubens Sarg.) during two winter seasons (1993-94 and 1994-95) and monitored field photosynthesis of these trees during one winter (1993-94). We also measured Pmax for mature montane trees from January through May 1995....

  1. 43 CFR 423.37 - Winter activities.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Winter activities. 423.37 Section 423.37 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE....37 Winter activities. (a) You must not tow persons on skis, sleds, or other sliding devices with a...

  2. 36 CFR 1002.19 - Winter activities.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Winter activities. 1002.19... RECREATION § 1002.19 Winter activities. (a) Skiing, snowshoeing, ice skating, sledding, innertubing.... (c) Failure to abide by area designations or activity restrictions established under this section is...

  3. 36 CFR 2.19 - Winter activities.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Winter activities. 2.19... RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.19 Winter activities. (a) Skiing, snowshoeing, ice... designations or activity restrictions established under this section is prohibited. ...

  4. How to Have a Healthy Winter | Poster

    Science.gov (United States)

    Without a doubt, winter is here. Between the icy weather and the recent hustle and bustle of the holidays, everyone is at an increased risk of getting sick. With that in mind, Occupational Health Services has a few simple tips for staying healthy this winter.

  5. Chapter 7: Migration and winter ecology

    Science.gov (United States)

    Deborah M. Finch; Jeffrey F. Kelly; Jean-Luc E. Cartron

    2000-01-01

    The willow flycatcher (Empidonax traillii) is a Neotropical migrant that breeds in North America, but winters in Central and northern South America. Little specific information is known about migration and wintering ecology of the southwestern willow flycatcher (E. t. extimus) (Yong and Finch 1997). Our report applies principally...

  6. Nutrient stoichiometry in winter wheat: Element concentration pattern reflects developmental stage and weather

    Science.gov (United States)

    Weih, M.; Pourazari, F.; Vico, G.

    2016-10-01

    At least 16 nutrient elements are required by plants for growth and survival, but the factors affecting element concentration and their temporal evolution are poorly understood. The objective was to investigate i) element concentration pattern in winter wheat as affected by crop developmental stage and weather, and ii) whether, in the short term, element stoichiometry reflects the type of preceding crop. We assessed the temporal trajectories of element concentration pattern (N, P, K, Ca, Mg, S, Mn, Fe, Cu, Na, Zn) across the life cycle (from seed to seed) of winter wheat field-grown in cool-temperate Sweden during two years with contrasting weather and when cultivated in monoculture or after different non-wheat preceding crops. We found strong influence of developmental stage on concentration pattern, with the greatest deviation from grain concentrations found in plants at the start of stem elongation in spring. Inter-annual differences in weather affected stoichiometry, but no evidence was found for a short-term preceding-crop effect on element stoichiometry. Winter wheat element stoichiometry is similar in actively growing plant tissues and seeds. Nitrogen exerts a strong influence on the concentration pattern for all elements. Three groups of elements with concentrations changing in concert were identified.

  7. Nutrient stoichiometry in winter wheat: Element concentration pattern reflects developmental stage and weather.

    Science.gov (United States)

    Weih, M; Pourazari, F; Vico, G

    2016-10-24

    At least 16 nutrient elements are required by plants for growth and survival, but the factors affecting element concentration and their temporal evolution are poorly understood. The objective was to investigate i) element concentration pattern in winter wheat as affected by crop developmental stage and weather, and ii) whether, in the short term, element stoichiometry reflects the type of preceding crop. We assessed the temporal trajectories of element concentration pattern (N, P, K, Ca, Mg, S, Mn, Fe, Cu, Na, Zn) across the life cycle (from seed to seed) of winter wheat field-grown in cool-temperate Sweden during two years with contrasting weather and when cultivated in monoculture or after different non-wheat preceding crops. We found strong influence of developmental stage on concentration pattern, with the greatest deviation from grain concentrations found in plants at the start of stem elongation in spring. Inter-annual differences in weather affected stoichiometry, but no evidence was found for a short-term preceding-crop effect on element stoichiometry. Winter wheat element stoichiometry is similar in actively growing plant tissues and seeds. Nitrogen exerts a strong influence on the concentration pattern for all elements. Three groups of elements with concentrations changing in concert were identified.

  8. Foraging patch selection in winter: a balance between predation risk and thermoregulation benefit.

    Science.gov (United States)

    Villén-Pérez, Sara; Carrascal, Luis M; Seoane, Javier

    2013-01-01

    In winter, foraging activity is intended to optimize food search while minimizing both thermoregulation costs and predation risk. Here we quantify the relative importance of thermoregulation and predation in foraging patch selection of woodland birds wintering in a Mediterranean montane forest. Specifically, we account for thermoregulation benefits related to temperature, and predation risk associated with both illumination of the feeding patch and distance to the nearest refuge provided by vegetation. We measured the amount of time that 38 marked individual birds belonging to five small passerine species spent foraging at artificial feeders. Feeders were located in forest patches that vary in distance to protective cover and exposure to sun radiation; temperature and illumination were registered locally by data loggers. Our results support the influence of both thermoregulation benefits and predation costs on feeding patch choice. The influence of distance to refuge (negative relationship) was nearly three times higher than that of temperature (positive relationship) in determining total foraging time spent at a patch. Light intensity had a negligible and no significant effect. This pattern was generalizable among species and individuals within species, and highlights the preponderance of latent predation risk over thermoregulation benefits on foraging decisions of birds wintering in temperate Mediterranean forests.

  9. Aluminium toxicity in winter wheat

    Directory of Open Access Journals (Sweden)

    Szabó A.

    2015-01-01

    Full Text Available Aluminium is the most frequent metal of the earth crust; it occurs mainly as biologically inactive, insoluble deposit. Environmental problems, industrial contaminations and acid rains increase the soil acidity, leading to the mobilization of Al. Half of the world’s potential arable lands are acidic; therefore, Al-toxicity decreases crop productivity. Wheat is a staple food for 35% of the world population. The effects of Al-stress (0.1 mM were studied on winter wheat; seedlings were grown hydroponically, at acidic pH. After two weeks, the root weight was decreased; a significant difference was found in the P- and Ca-content. The shoot weight and element content changed slightly; Al-content in the root was one magnitude higher than in the shoot, while Al-translocation was limited. The root plasma membrane H+-ATPase has central role in the uptake processes; Al-stress increased the Mg2+-ATPase activity of the microsomal fraction.

  10. Effects of root-zone nutrient concentration on cucumber grown in rockwool

    NARCIS (Netherlands)

    Giuffrida, F.; Heuvelink, E.; Stanghellini, C.

    2008-01-01

    We investigated the effects of root-zone heating in early morning to improve the growth of celery and reduce the cost of electricity for root-zone heating during winter in a hilly and mountainous area of Japan. Celery plants were transplanted to a soilless culture system in a sloped greenhouse.

  11. Understory bamboo discrimination using a winter image

    NARCIS (Netherlands)

    Wang, T.; Skidmore, A.K.; Toxopeus, A.G.; Liu, X.

    2009-01-01

    In this study, a new approach is presented that combines forest phenology and Landsat vegetation indices to estimate evergreen understory bamboo coverage in a mixed temperate forest. It was found that vegetation indices, especially the normalized difference vegetation index (NDVI) derived from

  12. Landscape phenology of Wisconsin's temperate mixed forest

    Science.gov (United States)

    Liang, Liang

    This dissertation covers an intensive study of the landscape phenology of Wisconsin's temperate mixed forest. It endeavors to connect conventional plant phenology study back to its ecological complexity (from gardens/trees to the forest) and to compare field-observed phenology with remotely sensed phenology for regional to global monitoring/forecasting applications (from the forest to biomes). A new research perspective: landscape phenology (LP) is proposed in this dissertation. LP is defined as an approach to seasonal vegetation dynamics that integrates spatial patterns and temporal processes within heterogeneous environment across multiple scales. High density in situ observations, remote sensing data, and spatio-temporal analysis are employed for understanding patterns and processes within the complexity of seasonal landscape dynamics. In particular, bi-daily spring forest phenologies of multiple tree/shrub species and understory plants were observed using field protocols or digital photography; high-frequency micrometeorological measurements were used in tandem with LiDAR-based microtopography/canopy heights as well as soil condition data, to characterize microenvironments; and high-resolution, multi-temporal satellite images were employed to facilitate plant community delineation and landscape scaling. A hierarchical upscaling approach is introduced, aiming to integrate in situ phenological observations with the remotely sensed phenological measures. Primary results from this work include: a detailed account of spatio-temporal variations of spring plant phenology and their environmental drivers within a typical seasonal forest; thermal time (accumulated growing degree hours) driven linear phenological models for six forest species; a landscape-level phenological progression regime driven by antecedent weather fluctuations; a conceptual landscape phenology model that assigns phenological behaviors to levels of population, community, and ecosystem patch; and a

  13. Large Plankton Enhance Heterotrophy Under Experimental Warming in a Temperate Coastal Ecosystem

    KAUST Repository

    Huete-Stauffer, Tamara Megan

    2017-12-15

    Microbes are key players in oceanic carbon fluxes. Temperate ecosystems are seasonally variable and thus suitable for testing the effect of warming on microbial carbon fluxes at contrasting oceanographic conditions. In four experiments conducted in February, April, August and October 2013 in coastal NE Atlantic waters, we monitored microbial plankton stocks and daily rates of primary production, bacterial heterotrophic production and respiration at in situ temperature and at 2 and 4°C over ambient values during 4-day incubations. Ambient total primary production (TPP) exceeded total community respiration (< 200 µm, TR) in winter and fall but not in spring and summer. The bacterial contribution to ecosystem carbon fluxes was low, with bacterial production representing on average 6.9 ± 3.2% of TPP and bacterial respiration (between 0.8 and 0.2 µm) contributing on average 35 ± 7% to TR. Warming did not result in a uniform increase in the variables considered, and most significant effects were found only for the 4°C increase. In the summer and fall experiments, under warm and nutrient-deficient conditions, the net TPP/TR ratio decreased by 39 and 34% in the 4°C treatment, mainly due to the increase in respiration of large organisms rather than bacteria. Our results indicate that the interaction of temperature and substrate availability in determining microbial carbon fluxes has a strong seasonal component in temperate planktonic ecosystems, with temperature having a more pronounced effect and generating a shift toward net heterotrophy under more oligotrophic conditions as found in summer and early fall.

  14. Zika vector transmission risk in temperate Australia: a vector competence study.

    Science.gov (United States)

    Duchemin, Jean-Bernard; Mee, Peter T; Lynch, Stacey E; Vedururu, Ravikiran; Trinidad, Lee; Paradkar, Prasad

    2017-06-09

    Zika virus is an emerging pathogen of global importance. It has been responsible for recent outbreaks in the Americas and in the Pacific region. This study assessed five different mosquito species from the temperate climatic zone in Australia and included Aedes albopictus as a potentially invasive species. Mosquitoes were orally challenged by membrane feeding with Zika virus strain of Cambodia 2010 origin, belonging to the Asian clade. Virus infection and dissemination were assessed by quantitative PCR on midgut and carcass after dissection. Transmission was assessed by determination of cytopathogenic effect of saliva (CPE) on Vero cells, followed by determination of 50% tissue culture infectious dose (TCID50) for CPE positive samples. Additionally, the presence of Wolbachia endosymbiont infection was assessed by qPCR and standard PCR. Culex mosquitoes were found unable to present Zika virus in saliva, as demonstrated by molecular as well as virological methods. Aedes aegypti, was used as a positive control for Zika infection and showed a high level of virus infection, dissemination and transmission. Local Aedes species, Ae. notoscriptus and, to a lesser degree, Ae. camptorhynchus were found to expel virus in their saliva and contained viral nucleic acid within the midgut. Molecular assessment identified low or no dissemination for these species, possibly due to low virus loads. Ae. albopictus from Torres Strait islands origin was shown as an efficient vector. Cx quinquefasciatus was shown to harbour Wolbachia endosymbionts at high prevalence, whilst no Wolbachia was found in Cx annulirostris. The Australian Ae. albopictus population was shown to harbour Wolbachia at high frequency. The risk of local Aedes species triggering large Zika epidemics in the southern parts of Australia is low. The potentially invasive Ae. albopictus showed high prevalence of virus in the saliva and constitutes a potential threat if this mosquito species becomes established in mainland

  15. Root and soil carbon distribution at shoulderslope and footslope positions of temperate toposequences cropped to winter wheat

    DEFF Research Database (Denmark)

    Chirinda, Ngoni; Roncossek, Svenja Doreen; Heckrath, Goswin Johann

    2014-01-01

    .06) at footslope (1.2 Mg DM ha- 1) than at shoulderslope positions (0.9 Mg DM ha− 1), in particular in the subsoil. Likewise shoot biomass was higher (P = 0.03) at footslope (10.3 Mg DM ha− 1) compared to shoulderslope (7.1 Mg DM ha− 1) positions. Soil bulk density increased with depth at shoulderslope positions...... root residues and likely soil redistribution processes. Management practices that increase C input at shoulderslope positions potentially enhance soil carbon storage and increase crop productivity, which would probably not be the case for C rich footslope soils. These findings imply that models used...

  16. Impact of Fertilizer N Application on the Grey Water Footprint of Winter Wheat in a NW-European Temperate Climate

    Directory of Open Access Journals (Sweden)

    Holger Brueck

    2016-08-01

    Full Text Available Nutrient management is central in water footprint analyses as it exerts strong control over crop yield and potentially contributes to pollution of freshwater, the so-called grey water footprint. In the frame of grey water footprint accounting, two methods are suggested, the constant leaching fraction approach (10% of applied fertilizer N and the N surplus approach. We compared both approaches and expected that the N surplus approach gives lower estimates of N leaching (and fertilizer-induced freshwater pollution when the N surplus is small and higher N leaching estimates when the N surplus is high. We compared N fertilizer application at which the N balance = 0 with the N application at which profit is highest. We further expect pronounced differences in N surplus between farm sites and years, due to yield and soil fertility differences. N response trials were conducted at several locations over three years in Germany. Fertilizer-induced N surplus was calculated from the difference between applied N fertilizer and grain N removal. N fertilizer application at which N balance = 0 (NBal = 0 was lower than economic optimum N application rates (NEcon. N surplus at NEcon was linearly correlated with the additional N applied. Pooled over years and sites the median N surplus was 39 kg N ha−1. Differences between sites rather than between years dominated variation in fertilizer-induced N surplus. Estimated N leaching at NEcon was on average 9% of applied fertilizer N. The product water footprint was on average 180 m3 per ton of grain, but differences between sites were substantial with values varying between 0 and >400 m3 per ton. Yield and protein contents were lower at NBal = 0 compared to NEcon indicating a trade-off between freshwater protection, yield, wheat grain quality and economic optimum N application. Site-specific fertilizer strategies which consider soil type, crop development, annual field water balance, in-season nutrient dynamics and crop rotational effects are key to minimize fertilizer‑induced leaching of N into groundwater.

  17. Evaluating Thermal Comfort in a Naturally Conditioned Office in a Temperate Climate Zone

    Directory of Open Access Journals (Sweden)

    Andrés Gallardo

    2016-07-01

    Full Text Available This study aims to determine the optimal approach for evaluating thermal comfort in an office that uses natural ventilation as the main conditioning strategy; the office is located in Quito-Ecuador. The performance of the adaptive model included in CEN Standard EN15251 and the traditional PMV model are compared with reports of thermal environment satisfaction surveys presented simultaneously to all occupants of the office to determine which of the two comfort models is most suitable to evaluate the thermal environment. The results indicate that office occupants have developed some degree of adaptation to the climatic conditions of the city where the office is located (which only demands heating operation, and tend to accept and even prefer lower operative temperatures than those considered optimum by applying the PMV model. This is an indication that occupants of naturally conditioned buildings are usually able to match their comfort temperature to their normal environment. Therefore, the application of the adaptive model included in CEN Standard EN15251 seems like the optimal approach for evaluating thermal comfort in naturally conditioned buildings, because it takes into consideration the adaptive principle that indicates that if a change occurs such as to produce discomfort, people tend to react in ways which restore their comfort.

  18. Brooding in a temperate zone land snail: seasonal and regional patterns

    NARCIS (Netherlands)

    Sulikowska-Drozd, A.; Maltz, T.K.; Kappes, H.

    2013-01-01

    The goal of this study is to assess if the reproductive strategy of a brooding land snail shifts along a climatic gradient. We focused on the following traits: timing and length of the reproductive season, brood size, ontogenetic dynamics of embryos, and reproductive mode (viviparity versus

  19. Catch crops and green manures as biological tools in nitrogen management in temperate zones

    OpenAIRE

    Thorup-Kristensen, Kristian; Magid, Jacob; Jensen, Lars Stoumann

    2003-01-01

    The review deals with the effects of nitrogen catch crops or green manures on the N dynamics of agricultural systems. The mechanisms of their effects are discussed, and it is discussed how they can be used to achieve the agricultural and environmental goals of N management.

  20. An examination of ecological isolating mechanisms of temperate North American grebes in their zone of sympatry

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Proposal for a study at Des Lacs National Wildlife Refuge and Lostwood National Wildlife Refuge to attempt to understand the mechanisms of ecological isolation of...

  1. Potential effects of acid precipitation on soils in the humid temperate zone

    Science.gov (United States)

    C. R. Frink; G. K. Voigt

    1976-01-01

    Acid precipitation is not a new phenomenon. As long as water has fallen on the surface of the earth it has probably contained varying amounts of oxides of carbons, nitrogen and sulfur that increase hydrogen ion activity. This was certainly true when volcanism prevailed. With the appearance of life spasmodic geologic expulsions of elements into the atmosphere were...

  2. Detecting `Temperate' Jupiters: the prospects of searching for transiting gas giants in Habitable Zones

    Science.gov (United States)

    Fleming, S. W.; Kane, S. R.; McCullough, P. R.; Chromey, F. R.

    2008-05-01

    Wide-field photometric surveys in search of transiting extrasolar planets are now numerous and have met with some success in finding hot Jupiters. These transiting planets have very short periods and very small semimajor axes, facilitating their discovery in such surveys. Transiting planets with longer periods present more of a challenge, since they transit their parent stars less frequently. This paper investigates the effects of observing windows on detecting transiting planets by calculating the fraction of planets with a given period that have zero, one (single), two (double), or >=3 (multiple) transits occurring while observations are being taken. We also investigate the effects of collaboration by performing the same calculations with combined observing times from two wide-field transit survey groups. For a representative field of the 2004 observing season, both XO and SuperWASP experienced an increase in single and double transit events by up to 20-40 per cent for planets with periods 14 Project using its data alone, between 20-40 per cent of planets with periods 14-150 d should have been observed at least once. For the SuperWASP Project, 50-90 per cent of planets with periods between 14-150 d should have been observed at least once. If XO and SuperWASP combine their observations, 50-100 per cent of planets with periods less than 20 d should be observed three or more times. We find that in general wide-field transit surveys have selected appropriate observing strategies to observe a significant fraction of transiting giant planets with semimajor axes larger than the hot Jupiter regime. The actual number of intermediate-period transiting planets that are detected depends upon their true semimajor axis distribution and the signal-to-noise ratio of the data. We therefore conclude that the investment of resources needed to investigate more sophisticated photometry calibrations or examine single and double transit events from wide-field surveys might be a worthwhile endeavour. The collaboration of different transit surveys by combining photometric data can greatly increase the number of transits observed for all semimajor axes. In addition, the increased number of data points can improve the signal-to-noise ratio of binned data, increasing the chances of detecting transiting extrasolar planets.

  3. Genetic resources as initial material for developing new soft winter wheat varieties

    Directory of Open Access Journals (Sweden)

    В. М. Кір’ян

    2016-12-01

    Full Text Available Purpose. To estimate genetic resources collection of soft winter wheat plants (new collection accessions of Ustymivka Experimental Station for Plant Production and select initial material for breeding of adaptive, productive and qualitative soft winter wheat varieties. Methods. Field experiment, laboratory testing. Results. The authors pre- sented results of study of over 1000 samples of gene pool of soft winter wheat from 25 countries during 2001–2005 in Ustymivka Experimental Station for Plant Production of Plant Production Institute nd. a. V. Ya. Yuriev, NAAS of Ukraine for a complex of economic traits. More than 400 new sources with high adaptive properties were selected that combine traits of high productivity and high quality of grain, early ripening, resistance to biotic and abiotic fac- tors (the assessment of samples for 16 valuable traits is given. The selected material comes from various agro-cli- matic zones, including zones of unsustainable agriculture. Conclusions. Recommended sources of traits that have breeding value will allow to enrich high-quality assortment of wheat and considerably accelerate breeding process du- ring development of new soft winter wheat varieties.

  4. What a difference a year makes: Patterns in CO2 and N2O accumulation during winter and surface and subsurface emissions.

    Science.gov (United States)

    Burton, D.; Janes, D.; Haverstock, J.

    2016-12-01

    In temperate climates soil microbial processes during the winter period may be slowed, but they do not stop. This results in accumulation of CO2 and N2O in the soil profile and often results in significant bursts of microbial activity during thawing events. Winters in Nova Scotia are no longer characterized by a single "spring thaw" event and it is more common to experience numerous thaw events throughout the winter period. We examined the accumulation of CO2 and N2O in the soil atmosphere, surface emissions and dissolved N2O being lost in drainage water from agricultural fields under conventional and no tillage management over a 6-year period. The diversity of patterns in soil gas accumulation in relation to freeze/thaw events and the timing and magnitude of surface and sub-surface emissions will be presented and related to climatic and management events.

  5. A checklist of the winter bird community in different habitat types of Rosekandy Tea Estate of Assam, India

    Directory of Open Access Journals (Sweden)

    A. Ahmed

    2014-02-01

    Full Text Available This study was aimed at preparing an inventory of the avifauna and to document the species composition of birds during winter in different habitat types of Rosekandy Tea Estate of Cachar District of Assam. Four habitat types, viz., tea plantation, ecotone zone, secondary growth forest and water bodies were selected within the tea estate and surveyed from mid-December 2010 (early winter to mid-April 2011 (late winter covering four months of survey. A total of 88 species were recorded during the survey period with the highest number of species in ecotone zone (n=63, followed by secondary forest (n=60, tea plantation (n=48 and water bodies (n=17. The species were further categorized into different feeding and habitat guilds to study the distribution of bird species in different habitat types according to various guilds.

  6. Black-tailed Godwits in West African winter staging areas : habitat use and hunting-related mortality

    NARCIS (Netherlands)

    Kleijn, D.; Kamp, van der J.; Monteiro, H.; Ndiaye, I.; Wymenga, E.; Zwarts, L.

    2010-01-01

    The persistence of the Dutch Black-tailed Godwit population depends largely on high adult survival. Adult survival may be influenced by hunting pressure and land use change in the wintering area, the West African coastal zone. Here we examine hunting pressure on and habitat use of Black-tailed

  7. The winter St. Helena climate index and extreme Benguela upwelling

    Science.gov (United States)

    Hagen, Eberhard; Agenbag, Jacobus J.; Feistel, Rainer

    2005-09-01

    Climate changes in the subtropical South-east Atlantic turn out to be well described by the St. Helena Island Climate Index (HIX) and observed fluctuations are in good agreement with inter-decadal variability of the entire South Atlantic Ocean. Year-to-year variations of the averaged austral winter HIX (July-September), representative of the main upwelling season, were compared with (i) corresponding averages of the geostrophic alongshore component of the south-east trade wind (SET) between St. Helena Island in the south-west and Luanda/Angola in the north-east, (ii) the meridional distribution of surface waters colder than 13 °C to characterise intense Benguela upwelling (IBU), and (iii) the meridional position of the Angola-Benguela Frontal Zone (ABFZ) determined by means of sea surface temperature images for offshore distances between 50 and 400 km. Temporal changes of these parameters were investigated and showed that the frequency of consecutive years of strong and relaxed Benguela upwelling is characterised by a quasi-cycle of about 11-14 years. It is proposed that the index of the winter HIX may be used as a 'surveyor's rod' to describe interannual changes in the Benguela upwelling regime as well as those of the embedded marine ecosystem.

  8. Nitrogen Uptake in the Northeastern Arabian Sea during Winter Cooling

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2010-01-01

    Full Text Available The uptake of dissolved inorganic nitrogen by phytoplankton is an important aspect of the nitrogen cycle of oceans. Here, we present nitrate (NO3- and ammonium (NH4+ uptake rates in the northeastern Arabian Sea using 15N tracer technique. In this relatively underexplored region, productivity is high during winter due to supply of nutrients by convective mixing caused by the cooling of the surface by the northeast monsoon winds. Studies done during different months (January and late February-early March of the northeast monsoon 2003 revealed a fivefold increase in the average euphotic zone integrated NO3- uptake from January (2.3 mmolN m−2d−1 to late February-early March (12.7 mmolN m−2d−1. The f-ratio during January appeared to be affected by the winter cooling effect and increased by more than 50% from the southernmost station to the northern open ocean stations, indicating hydrographic and meteorological control. Estimates of NO3- residence time suggested that NO3- entrained in the water column during January contributed to the development of blooms during late February-early March.

  9. Jasna: A new winter rapeseed cultivar

    Directory of Open Access Journals (Sweden)

    Marjanović-Jeromela Ana

    2009-01-01

    Full Text Available The program of winter rapeseed breeding at Institute of Field and Vegetable Crops covers the development of winter and spring rapeseed cultivars and hybrids. Winter rapeseed cultivars are selected for high and stabile grain and oil yield, good oil quality, low erucic acid and glucosinolate content (type 00 and tolerance to stresses caused by abiotic and biotic factors. This paper reviews agronomic characteristics and grain and oil quality of a new cultivar of winter rapeseed Jasna. In the trials of the Serbian Commission for new cultivars registration, cultivar Jasna had higher grain yield then standard, in the three locations and two years. In average the yield was 4566 kg/ha. Oil content is at the level of the standard. The erucic acid content and glucosinolate content are lower then that in the standard and that are positive characteristics. .

  10. VT Mean Winter Precipitation - 1971-2000

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) ClimatePrecip_PRECIPW7100 includes mean winter precipitation data (October through March) for Vermont (1971-2000). It's a raster dataset derived...

  11. Esteemed Alumnus, Former POW Honors Winter Graduates

    OpenAIRE

    Stewart, Kenneth A.

    2015-01-01

    The Naval Postgraduate School (NPS) honored some 334 graduates from 17 countries earning 335 advanced degrees during its Winter Quarter Commencement Ceremony in King Auditorium, March 27. NPS President retired Vice Adm. Ronald A. Route presided over the ceremony.

  12. Winter swimming improves general well-being.

    Science.gov (United States)

    Huttunen, Pirkko; Kokko, Leena; Ylijukuri, Virpi

    2004-05-01

    This study deals with the effects of regular winter swimming on the mood of the swimmers. Profile of Mood State (POMS) and OIRE questionnaires were completed before (October) and after (January) the four-month winter swimming period. In the beginning, there were no significant differences in the mood states and subjective feelings between the swimmers and the controls. The swimmers had more diseases (about 50%) diagnosed by a physician. Tension, fatigue, memory and mood negative state points in the swimmers significantly decreased with the duration of the swimming period. After four months, the swimmers felt themselves to be more energetic, active and brisk than the controls. Vigour-activity scores were significantly greater (p winter swimming had relieved pains. Improvement of general well-being is thus a benefit induced by regular winter swimming.

  13. Providing plastic zone extrusion

    Science.gov (United States)

    Manchiraju, Venkata Kiran; Feng, Zhili; David, Stan A.; Yu, Zhenzhen

    2017-04-11

    Plastic zone extrusion may be provided. First, a compressor may generate frictional heat in stock to place the stock in a plastic zone of the stock. Then, a conveyer may receive the stock in its plastic zone from the compressor and transport the stock in its plastic zone from the compressor. Next, a die may receive the stock in its plastic zone from the conveyer and extrude the stock to form a wire.

  14. Drought and Winter Drying (Pest Alert)

    Science.gov (United States)

    USDA Forest Service

    Drought and winter drying have periodically caused major damage to trees. Drought reduces the amount of water available in the soil. In the case of winter drying, the water may be in the soil, but freezing of the soil makes the water unavailable to the tree. In both cases, more water is lost through transpiration than is available to the plant. Symptoms of drought and...

  15. Winter swimming improves general well-being

    OpenAIRE

    Huttunen, Pirkko; Kokko, Leena; Ylijukuri, Virpi

    2004-01-01

    Objectives. This study deals with the effects of regular winter swimming on the mood of the swimmers. Methods. Profile of Mood State (POMS) and OIRE questionnaires were completed before (October) and after (January) the fourmonth winter swimming period. Results. In the beginning, there were no significant differences in the mood states and subjective feelings between the swimmers and the controls. The swimmers had more diseases (about 50%) diagnosed by a physician. Tension, fatigue, memory an...

  16. Hail resistance of solar collectors with tempered glass covers

    Science.gov (United States)

    Lof, G. O. G.; French, R. R.

    1980-01-01

    The resistance of solar collectors glazed with 3 mm of tempered glass to hailstones of up to 10 cm in diameter and 0.5 kg in weight which fell on Fort Collins, Colorado is discussed. Of the ten solar heating systems directly in the hailpath with tempered glass covers, seven were undamaged, two lost one collector panel each, and a 700-panel collector had seven broken covers, amounting to a total breakage of nine panels out of 956, approximately 1%. In addition, one system with nontempered glass covers suffered two glass punctures in a 26-panel collector. It is concluded that the risk of hail damage to commercial solar collectors glazed with 3-mm tempered glass is negligibly small, and greatly exceeded by the risk of hail damage to the roofs of buildings and automobiles or to fiberglass-reinforced polyester sheets used as collector glazings.

  17. Tempered stable distributions stochastic models for multiscale processes

    CERN Document Server

    Grabchak, Michael

    2015-01-01

    This brief is concerned with tempered stable distributions and their associated Levy processes. It is a good text for researchers interested in learning about tempered stable distributions.  A tempered stable distribution is one which takes a stable distribution and modifies its tails to make them lighter. The motivation for this class comes from the fact that infinite variance stable distributions appear to provide a good fit to data in a variety of situations, but the extremely heavy tails of these models are not realistic for most real world applications. The idea of using distributions that modify the tails of stable models to make them lighter seems to have originated in the influential paper of Mantegna and Stanley (1994). Since then, these distributions have been extended and generalized in a variety of ways. They have been applied to a wide variety of areas including mathematical finance, biostatistics,computer science, and physics.

  18. Vadose zone microbiology

    Energy Technology Data Exchange (ETDEWEB)

    Kieft, Thomas L.; Brockman, Fred J.

    2001-01-17

    The vadose zone is defined as the portion of the terrestrial subsurface that extends from the land surface downward to the water table. As such, it comprises the surface soil (the rooting zone), the underlying subsoil, and the capillary fringe that directly overlies the water table. The unsaturated zone between the rooting zone and the capillary fringe is termed the "intermediate zone" (Chapelle, 1993). The vadose zone has also been defined as the unsaturated zone, since the sediment pores and/or rock fractures are generally not completely water filled, but instead contain both water and air. The latter characteristic results in the term "zone of aeration" to describe the vadose zone. The terms "vadose zone," "unsaturated zone", and "zone of aeration" are nearly synonymous, except that the vadose zone may contain regions of perched water that are actually saturated. The term "subsoil" has also been used for studies of shallow areas of the subsurface immediately below the rooting zone. This review focuses almost exclusively on the unsaturated region beneath the soil layer since there is already an extensive body of literature on surface soil microbial communities and process, e.g., Paul and Clark (1989), Metting (1993), Richter and Markowitz, (1995), and Sylvia et al. (1998); whereas the deeper strata of the unsaturated zone have only recently come under scrutiny for their microbiological properties.

  19. Winter Dew Harvest in Mexico City

    Directory of Open Access Journals (Sweden)

    Arias-Torres Jorge Ernesto

    2015-12-01

    Full Text Available This study presents experimental and theoretical results of winter dew harvest in México City in terms of condensation rate. A simplified theoretical model based on a steady-state energy balance on a radiator-condenser was fitted, as a function of the ambient temperature, the relative humidity and the wind velocity. A glass sheet and aluminum sheet white-painted were used as samples over the outdoor experiments. A good correlation was obtained between the theoretical and experimental data. The experimental results show that there was condensation in 68% of the winter nights on both condensers. The total winter condensed mass was 2977 g/m2 and 2888 g/m2 on the glass sheet and aluminum sheet white-painted, respectively. Thus, the condensed mass on the glass was only 3% higher than that on the painted surface. The maximum nightly dew harvests occurred during December, which linearly reduced from 50 g/m2 night to 22 g/m2 night as the winter months went by. The condensation occurred from 1:00 a.m. to 9:00 a.m., with maximum condensation rates between 6:00 a.m. and 7:00 a.m. The dew harvest can provide a partial alternative to the winter water shortage in certain locations with similar climates to the winter in Mexico City, as long as pollution is not significant.

  20. Chilling-Mediated DNA Methylation Changes during Dormancy and Its Release Reveal the Importance of Epigenetic Regulation during Winter Dormancy in Apple (Malus x domestica Borkh.)

    Science.gov (United States)

    Kumar, Gulshan; Rattan, Usha Kumari; Singh, Anil Kumar

    2016-01-01

    Winter dormancy is a well known mechanism adopted by temperate plants, to mitigate the chilling temperature of winters. However, acquisition of sufficient chilling during winter dormancy ensures the normal phenological traits in subsequent growing period. Thus, low temperature appears to play crucial roles in growth and development of temperate plants. Apple, being an important temperate fruit crop, also requires sufficient chilling to release winter dormancy and normal phenological traits, which are often associated with yield and quality of fruits. DNA cytosine methylation is one of the important epigenetic modifications which remarkably affect the gene expression during various developmental and adaptive processes. In present study, methylation sensitive amplified polymorphism was employed to assess the changes in cytosine methylation during dormancy, active growth and fruit set in apple, under differential chilling conditions. Under high chill conditions, total methylation was decreased from 27.2% in dormant bud to 21.0% in fruit set stage, while no significant reduction was found under low chill conditions. Moreover, the demethylation was found to be decreased, while methylation increased from dormant bud to fruit set stage under low chill as compared to high chill conditions. In addition, RNA-Seq analysis showed high expression of DNA methyltransferases and histone methyltransferases during dormancy and fruit set, and low expression of DNA glcosylases during active growth under low chill conditions, which was in accordance with changes in methylation patterns. The RNA-Seq data of 47 genes associated with MSAP fragments involved in cellular metabolism, stress response, antioxidant system and transcriptional regulation showed correlation between methylation and their expression. Similarly, bisulfite sequencing and qRT-PCR analysis of selected genes also showed correlation between gene body methylation and gene expression. Moreover, significant association

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

    Directory of Open Access Journals (Sweden)

    Л. М. Голик

    2007-12-01

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

  2. Sexually active bucks are efficient to stimulate female ovulatory activity during the anestrous season also under temperate latitudes.

    Science.gov (United States)

    Chasles, Manon; Chesneau, Didier; Moussu, Chantal; Delgadillo, José Alberto; Chemineau, Philippe; Keller, Matthieu

    2016-05-01

    Goats are seasonal breeders and photoperiod is the main cue controlling the onset and offset of the breeding season. Nevertheless introducing a sexually active buck in a group of females during anestrous can stimulate their reproductive function and induce ovulation. This "male-effect" is very efficient under subtropical latitudes, when using sexually active males previously stimulated by a photoperiodic treatment. However, there is less evidence of its feasibility under temperate latitudes where the more important variation in day length could be responsible for a stronger inhibition of female sexual activity. The aim of this study was therefore to determine whether intense sexual activity can be induced in alpine bucks during the non-breeding season by a long-day treatment under temperate latitude and if these males could be used to produce an efficient male-effect. Bucks (n=21) were divided in two groups, one submitted to a photoperiodic treatment from November 1st to January 15th and then switched to natural photoperiod, while the other group remained entirely under the natural photoperiod. The ones submitted to this light treatment exhibit higher testicular volume and testosterone level 6 weeks after the end of the treatment. At the end of March, bucks were used to stimulate anestrous does (n=41) continuously for 15 days. We showed that (a) light treatment was efficient to induce an increase of sexual activity in bucks and (b) that the introduction of stimulated bucks among females induced a significantly higher proportion of ovulation in anestrous does than control bucks (86% vs 5%). Our results indicate that under temperate latitudes induction of ovulation in females during the anestrous season is feasible using bucks treated with long-days during winter. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Uptake of inorganic phosphorus by temperate seagrass beds of Posidonia and Amphibolis in Southern Australia.

    Science.gov (United States)

    Nayar, S

    2015-08-01

    Seagrasses occupy a narrow band of sandy seabed close to the coast and are therefore vulnerable to anthropogenic influences, particularly meadows near large population centres. Over 5000 ha of seagrasses have been lost from Adelaide coastal waters (South Australia) over the past 70 years and much of this loss has been attributed to nutrient inputs from wastewater, industrial and stormwater discharges. This led to the Adelaide Coastal Waters Study to understand processes along the Adelaide metropolitan coast that led to seagrass loss. This study, a subset of the larger ACWS study, used in situ nutrient spike approach to obtain ecologically relevant estimates of seasonal variability in phosphorus uptake in two species of temperate seagrass common to this coast (Amphibolis antarctica and Posidonia angustifolia). Total uptake of phosphorus by biological components in the seagrass beds, viz., seagrass, epiphytes and phytoplankton, was negligible, never exceeding 0.5% of the total resource. Phosphorus uptake rate varied seasonally with higher rates in winter (1.49 μmol P.g(-1) DW.h(-1)) and lower rates in spring (0.70 μmol P.g(-1) DW.h(-1)) for Amphibolis and highest in winter (2.09 μmol P.g(-1) DW.h(-1)) and least in spring (0.14 μmol P.g(-1) DW.h(-1)) for Posidonia. Low biological uptake rates of inorganic phosphorus could be attributed to carbonate sediments and particulates in the water column binding inorganic phosphorus, limiting its availability for biological uptake. From an environmental perspective, seagrass beds in the Adelaide coastal waters account for the assimilation of only 5.4% (19.53 t yr(-1)) of the total anthropogenic inputs of phosphorus.

  4. Psychrophilic versus psychrotolerant bacteria--occurrence and significance in polar and temperate marine habitats.

    Science.gov (United States)

    Helmke, E; Weyland, H

    2004-07-01

    The numerical dominance and ecological role of psychrophilic bacteria in bottom sediments, sea ice, surface water and melt pools of the polar oceans were investigated using isolates, colony forming units (CFU) and metabolic activities. All sediment samples of the Southern Ocean studied showed a clear numerical dominance of cold-loving bacteria. In Arctic sediments underlying the influence of cold polar water bodies psychrophiles prevailed also but they were less dominant in sediments influenced by the warm Atlantic Water. A predominance of psychrophiles was further found in consolidated Antarctic sea ice as well as in multiyear Arctic sea ice and in melt pools on top of Arctic ice floes. A less uniform adaptation response was, however, met in polar surface waters. In the very northern part of the Fram Strait (Arctic Ocean) we found bacterial counts and activities at 1 degree C exceeding those at 22 degrees C. In surface water of the Weddell Sea (Southern Ocean) psychrophiles also dominated numerically in early autumn but the dominance declined obviously with the onset of winter-water and a decrease of chlorphyll a. Otherwise in surface water of the Southern Ocean CFUs were higher at 22 degrees C than at 1 degree C while activities were vice versa indicating at least a functional dominance of psychrophiles. Even in the temperate sediments of the German Bight true psychrophiles were present and a clear shift towards cold adapted communities in winter observed. Among the polar bacteria a more pronounced cold adaptation of Antarctic in comparison with Arctic isolates was obtained. The results and literature data indicate that stenothermic cold adapted bacteria play a significant role in the global marine environment. On the basis of the temperature response of our isolates from different habitats it is suggested to expand the definition of Morita in order to meet the cold adaptation strategies of the bacteria in the various cold habitats.

  5. Controlling effects of irradiance and heterotrophy on carbon translocation in the temperate coral Cladocora caespitosa.

    Directory of Open Access Journals (Sweden)

    Pascale Tremblay

    Full Text Available Temperate symbiotic corals, such as the Mediterranean species Cladocora caespitosa, live in seasonally changing environments, where irradiance can be ten times higher in summer than winter. These corals shift from autotrophy in summer to heterotrophy in winter in response to light limitation of the symbiont's photosynthesis. In this study, we determined the autotrophic carbon budget under different conditions of irradiance (20 and 120 µmol photons m(-2 s(-1 and feeding (fed three times a week with Artemia salina nauplii, and unfed. Corals were incubated in H(13CO(3 (--enriched seawater, and the fate of (13C was followed in the symbionts and the host tissue. The total amount of carbon fixed by photosynthesis and translocated was significantly higher at high than low irradiance (ca. 13 versus 2.5-4.5 µg cm(-2 h(-1, because the rates of photosynthesis and carbon fixation were also higher. However, the percent of carbon translocation was similar under the two irradiances, and reached more than 70% of the total fixed carbon. Host feeding induced a decrease in the percentage of carbon translocated under low irradiance (from 70 to 53%, and also a decrease in the rates of carbon translocation per symbiont cell under both irradiances. The fate of autotrophic and heterotrophic carbon differed according to irradiance. At low irradiance, autotrophic carbon was mostly respired by the host and the symbionts, and heterotrophic feeding led to an increase in host biomass. Under high irradiance, autotrophic carbon was both respired and released as particulate and dissolved organic carbon, and heterotrophic feeding led to an increase in host biomass and symbiont concentration. Overall, the maintenance of high symbiont concentration and high percentage of carbon translocation under low irradiance allow this coral species to optimize its autotrophic carbon acquisition, when irradiance conditions are not favourable to photosynthesis.

  6. Controlling Effects of Irradiance and Heterotrophy on Carbon Translocation in the Temperate Coral Cladocora caespitosa

    Science.gov (United States)

    Tremblay, Pascale; Ferrier-Pagès, Christine; Maguer, Jean François; Rottier, Cécile; Legendre, Louis; Grover, Renaud

    2012-01-01

    Temperate symbiotic corals, such as the Mediterranean species Cladocora caespitosa, live in seasonally changing environments, where irradiance can be ten times higher in summer than winter. These corals shift from autotrophy in summer to heterotrophy in winter in response to light limitation of the symbiont’s photosynthesis. In this study, we determined the autotrophic carbon budget under different conditions of irradiance (20 and 120 µmol photons m−2 s−1) and feeding (fed three times a week with Artemia salina nauplii, and unfed). Corals were incubated in H13CO3−-enriched seawater, and the fate of 13C was followed in the symbionts and the host tissue. The total amount of carbon fixed by photosynthesis and translocated was significantly higher at high than low irradiance (ca. 13 versus 2.5–4.5 µg cm−2 h−1), because the rates of photosynthesis and carbon fixation were also higher. However, the percent of carbon translocation was similar under the two irradiances, and reached more than 70% of the total fixed carbon. Host feeding induced a decrease in the percentage of carbon translocated under low irradiance (from 70 to 53%), and also a decrease in the rates of carbon translocation per symbiont cell under both irradiances. The fate of autotrophic and heterotrophic carbon differed according to irradiance. At low irradiance, autotrophic carbon was mostly respired by the host and the symbionts, and heterotrophic feeding led to an increase in host biomass. Under high irradiance, autotrophic carbon was both respired and released as particulate and dissolved organic carbon, and heterotrophic feeding led to an increase in host biomass and symbiont concentration. Overall, the maintenance of high symbiont concentration and high percentage of carbon translocation under low irradiance allow this coral species to optimize its autotrophic carbon acquisition, when irradiance conditions are not favourable to photosynthesis. PMID:22970284

  7. Continuous measurements of methane flux in two Japanese temperate forests based on the micrometeorological and chamber methods

    Science.gov (United States)

    Yoshikawa, K.; Ueyama, M.; Takagi, K.; Kominami, Y.

    2015-12-01

    Methane (CH4) budget in forest ecosystems have not been accurately quantified due to limited measurements and considerable spatiotemporal heterogeneity. In order to quantify CH4 fluxes at temperate forest at various spatiotemporal scales, we have continuously measured CH4 fluxes at two upland forests based on the micrometeorological hyperbolic relaxed eddy accumulation (HREA) and automated dynamic closed chamber methods.The measurements have been conducted at Teshio experimental forest (TSE) since September 2013 and Yamashiro forest meteorology research site (YMS) since November 2014. Three automated chambers were installed on each site. Our system can measure CH4 flux by the micrometeorological HREA, vertical concentration profile at four heights, and chamber measurements by a laser-based gas analyzer (FGGA-24r-EP, Los Gatos Research Inc., USA).Seasonal variations of canopy-scale CH4 fluxes were different in each site. CH4 was consumed during the summer, but was emitted during the fall and winter in TSE; consequently, the site acted as a net annual CH4 source. CH4 was steadily consumed during the winter, but CH4 fluxes fluctuated between absorption and emission during the spring and summer in YMS. YMS acted as a net annual CH4 sink. CH4 uptake at the canopy scale generally decreased with rising soil temperature and increased with drying condition for both sites. CH4 flux measured by most of chambers showed the consistent sensitivity examined for the canopy scale to the environmental variables. CH4 fluxes from a few chambers located at a wet condition were independent of variations in soil temperature and moisture at both sites. Magnitude of soil CH4 uptake was higher than the canopy-scale CH4 uptake. Our results showed that the canopy-scale CH4 fluxes were totally different with the plot-scale CH4 fluxes by chambers, suggesting the considerable spatial heterogeneity in CH4 flux at the temperate forests.

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

    Science.gov (United States)

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

    2017-05-31

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

  9. Influence of tempering temperature on mechanical properties of cast steels

    OpenAIRE

    G. Golański

    2008-01-01

    The paper presents results of research on the influence of tempering temperature on structure and mechanical properties of bainite hardened cast steel: G21CrMoV4 – 6 (L21HMF) and G17CrMoV5 – 10 (L17HMF). Investigated cast steels were taken out from internal frames of steam turbines serviced for long time at elevated temperatures. Tempering of the investigated cast steel was carried out within the temperature range of 690 ÷ 730 C (G21CrMoV4 – 6) and 700 ÷ 740 C (G17CrMoV5 – 10). After temperin...

  10. Effect of thermal tempering on microstructure and mechanical properties of Mg-AZ31/Al-6061 diffusion bonding

    Energy Technology Data Exchange (ETDEWEB)

    Jafarian, Mojtaba [Young Researchers and Elite Club, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Rizi, Mohsen Saboktakin, E-mail: M.saboktakin@Pa.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of); Department of Industrial Engineering, Lenjan Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Jafarian, Morteza [Young Researchers and Elite Club, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Honarmand, Mehrdad [Department of Mechanical Engineering, Tiran Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Javadinejad, Hamid Reza; Ghaheri, Ali [Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of); Department of Industrial Engineering, Lenjan Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Bahramipour, Mohammad Taghi [Materials Engineering Department, Hakim Sabzevari University, Sabzevar, 397 (Iran, Islamic Republic of); Ebrahimian, Marzieh [Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of); Department of Industrial Engineering, Lenjan Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of)

    2016-06-01

    The objective of this study is to investigate the effect of the types thermal tempering of aluminum alloy on microstructure and mechanical properties of AZ31-O Mg and Al 6061-T6 diffusion bonding. Using Optical Microscope (OM) and Scanning Electron Microscopes (SEM) equipped with EDS analysis and line scan the interfaces of joints were evaluated. The XRD analysis was carried out to characterize phase constitution near the interface zone. The mechanical properties of joints were measured using Vickers micro-hardness and shear strength. According to the results in bonding of AZ31-Mg/Al-6061-O, in less plastic deformation in magnesium alloy, diffusion rate of most magnesium atoms occurred to aluminum alloy and formation of diffusion zone with minimum micro-hardness (140 HV) and maximum shear strength (32 MPa) compared to Al 6061-T6/Mg-AZ31 bonding. Evaluation of fracture surfaces indicates an occurrence of failure from the brittle intermetallic phases. - Highlights: • Diffusion bonding AZ31 to Al-6061withoutany interlayer was successful. • Thermal tempered aluminum alloy plays a vital role in the mechanical properties of joint. • Less thickness of reaction layers and micro-hardness in bonding annealed Al- 6061 layers to AZ31 was achieved. • Fracture surfaces indicated that the onset of fracture from intermetallic compounds resulted in fracture of the cleavage.

  11. SWFSC/MMTD/CCE: Leatherback Use of Temperate Habitat (LUTH) 2008

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Leatherback Use of Temperate Habitat (LUTH) survey is an ecosystem assessment of temperate foraging habitats of endangered leatherback turtles off the coast of...

  12. Morphofunctional state of the adrenal glands in albino rats under conditions of toxic stress caused by cadmium salt in winter and summer periods.

    Science.gov (United States)

    Kotelnikova, S V; Kargina, M V; Kotelnikov, A V

    2011-06-01

    We studied the morphology and function of the adrenal glands in male and female albino rats in cadmium intoxication during winter and summer periods (January and July). In animals of the control group, sex-related differences in the total area of the adrenal glands and in the size of their zones were revealed. In females, zones of adrenal gland were larger than in males. In winter months, these differences were most pronounced. Analysis of seasonal differences in the area of the adrenal glands in males revealed no significant differences in winter and summer months. Irrespective of the season and gender, cadmium chloride treatment led to an increase in the size of the adrenal glands. Cadmium salts caused more pronounced functional strain in males in winter months and in females in summer.

  13. The investigation of applicability of the Hollomon-Jaffe equation on tempering the HSLA steel

    OpenAIRE

    A. Patarić; Mihailović, M.; Z. Gulišija; Z. Janjušević

    2009-01-01

    High strength low-alloyed (HSLA) Cr-Mn-Si steels belong to a group of steels that can reach their full mechanical properties after quenching and tempering. Those properties depend both on the temperature and time of tempering. Knowing the tempering parameters, it is possible to reach the desired properties of the treated steel. Some results on investigating the Hollomon-Jaffe equation (in parametric form) application for tempering of HSLA steel, are shown in this paper. The experiments were p...

  14. Examining winter visitor use in Yellowstone National Park

    Science.gov (United States)

    Mae A. Davenport; Wayne A. Freimund; William T. Borrie; Robert E. Manning; William A. Valliere; Benjamin Wang

    2000-01-01

    This research was designed to assist the managers of Yellowstone National Park (YNP) in their decision making about winter visitation. The focus of this report is on winter use patterns and winter visitor preferences. It is the author’s hope that this information will benefit both the quality of winter experiences and the stewardship of the park resources. This report...

  15. Monitoring Spring Recovery of Photosynthesis and Spectral Reflectance in Temperate Evergreen and Mixed Deciduous Forests

    Science.gov (United States)

    Wong, C. Y.; Arain, M. A.; Ensminger, I.

    2015-12-01

    Evergreen conifers in boreal and temperate regions undergo strong seasonal changes in photoperiod and temperatures, which characterizes their photosynthetic activity with high activity in the growing season and downregulation during the winter season. Monitoring the timing of the transitions in evergreens is difficult since it's a largely invisible process, unlike deciduous trees that have a visible budding and senescence sequence. Spectral reflectance and the photochemical reflectance index (PRI), often used as a proxy for photosynthetic light-use efficiency, provides a promising tool to track the transition of evergreens between inactive and active photosynthetic states. To better understand the relationship between PRI and photosynthetic activity and to contrast this relationship between plant functional types, the spring recovery of an evergreen forest and mixed deciduous forest was monitored using spectral reflectance, chlorophyll fluorescence and gas exchange. All metrics indicate photosynthetic recovery during the spring season. These findings indicate that PRI can be used to observe the spring recovery of photosynthesis in evergreen conifers but may not be best suited for deciduous trees. These findings have implications for remote sensing, which provides a promising long-term monitoring system of whole ecosystems, which is important since their roles in the carbon cycle may shift in response to climate change.

  16. Seasonal dynamics of fungal communities in a temperate oak forest soil.

    Science.gov (United States)

    Voříšková, Jana; Brabcová, Vendula; Cajthaml, Tomáš; Baldrian, Petr

    2014-01-01

    Fungi are the agents primarily responsible for the transformation of plant-derived carbon in terrestrial ecosystems. However, little is known of their responses to the seasonal changes in resource availability in deciduous forests, including photosynthate allocation below ground and seasonal inputs of fresh litter. Vertical stratification of and seasonal changes in fungal abundance, activity and community composition were investigated in the litter, organic and upper mineral soils of a temperate Quercus petraea forest using ergosterol and extracellular enzyme assays and amplicon 454-pyrosequencing of the rDNA-ITS region. Fungal activity, biomass and diversity decreased substantially with soil depth. The highest enzyme activities were detected in winter, especially in litter, where these activities were followed by a peak in fungal biomass during spring. The litter community exhibited more profound seasonal changes than did the community in the deeper horizons. In the litter, saprotrophic genera reached their seasonal maxima in autumn, but summer typically saw the highest abundance of ectomycorrhizal taxa. Although the composition of the litter community changes over the course of the year, the mineral soil shows changes in biomass. The fungal community is affected by season. Litter decomposition and phytosynthate allocation represent important factors contributing to the observed variations. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  17. Inferring basal plasticity in a temperate ice cap from observationally constrained ice-flow models

    Science.gov (United States)

    Minchew, B. M.; Simons, M.; Bjornsson, H.; Palsson, F.; Morlighem, M.; Seroussi, H. L.; Larour, E. Y.; Hensley, S.

    2014-12-01

    Despite the importance of glacier bed mechanics to understanding glacier flow and projecting the future glacier states, our knowledge of some fundamental concepts concerning the coupling of basal shear stress, water pressure, and slip rate remains incomplete. Here we infer the existence of a plastically deforming bed beneath Hofsjökull, a temperate ice cap in central Iceland, using numerical ice flow models constrained by surface velocity observations. Basal plasticity is evident by the independence of basal shear stress and basal slip rate, both of which we inferred using higher-order flow models in the Ice Sheet Systems Model (ISSM). We derived seasonal surface velocity fields from airborne interferometric synthetic aperture radar (InSAR) data collected with NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) in winter and during the early melt season. Using velocity fields from different seasons and applying a simple plastic model for basal stress, we present estimates of surface-melt-driven changes in basal water pressure that correspond to observed variations in surface velocity. Our data and an idealized basal slip model show that the sensitivity of basal slip to basal water pressure variability scales as the inverse of the ice surface slope, making glaciers with shallow surface slopes more sensitive to basal water pressure fluctuations than steep-sloped glaciers.

  18. River conferences under temperate valley glaciers

    Science.gov (United States)

    Lane, Stuart; Egli, Pascal; Irving, James

    2017-04-01

    Both geophysical measurements (ground penetrating radar) and hydrological inference has shown that subglacial drainage networks are dendritic and that means that they must have confluences. In general, there are very few studies of rivers under glaciers and almost no consideration at all of confluences, despite the fact that they could be a critical parameter in understanding coupling at the ice-sediment bed interface. Subglacial channels, normally known as conduits, are typically associated with the combined effect of hydraulic pressure driven ice melt (which opens them) and ice overburden pressure (which closes them). Inferences from dye break out curves shows that has the efficiency of ice melt increases progressively during the summer ablation season, melt rates closure rates and a channelized system becomes progressively more effective. Most recently, measurements at the Upper Arolla Glacier show that the effects of this growing efficiency is an evolution in the subglacial hydrological system towards higher peak flows and lower base flows later in the melt season. This increases the probability that late in the melt season, sediment transport becomes discontinuous, with overnight deposition and daytime erosion. This would in turn produce the rapid reductions in sediment transport capacity overnight needed to deposit sediment and to block conduits, increase basal water pressure and explain the hydraulic jacking observed in snout marginal zones at a time when it should not be expected. The question that follows is what effects do confluences have on this process? The geometry of subglacial channels is such that when they join they lead to rapid changes in hydraulic geometry. Crucially, these are likely to have a non-linear impact upon sediment transport capacity, which should reduce disproportionally in the conduits downstream of the junction. Thus, it is possible that confluence zones under glaciers become sites of very rapid sediment accumulation and blockage

  19. 40 CFR 426.60 - Applicability; description of the automotive glass tempering subcategory.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the automotive glass tempering subcategory. 426.60 Section 426.60 Protection of Environment ENVIRONMENTAL... Automotive Glass Tempering Subcategory § 426.60 Applicability; description of the automotive glass tempering...

  20. A note on the water budget of temperate glaciers

    NARCIS (Netherlands)

    Oerlemans, J.

    2013-01-01

    In this note, the total dissipative melting in temperate glaciers is studied. The analysis is based on the notion that the dissipation is determined by the loss of potential energy due to the downward motion of mass (ice, snow, meltwater and rain). A mathematical formulation of the dissipation is

  1. Effect of climate change on temperate forest ecosystems

    NARCIS (Netherlands)

    Brolsma, R.J.|info:eu-repo/dai/nl/304847364

    2010-01-01

    In temperate climates groundwater can have a strong effect on vegetation, because it can influence the spatio-temporal distribution of soil moisture and therefore water and oxygen stress of vegetation. Current IPCC climate projections based on CO2 emission scenarios show a global temperature rise

  2. Dry kiln schedules for commercial woods : temperate and tropical

    Science.gov (United States)

    R. Sidney Boone; Charles J. Kozlik; Paul J. Bois; Eugene M. Wengert

    1988-01-01

    This report contains suggested dry kiln schedules for over 500 commercial woods, both temperate and tropical. Kiln schedules are completely assembled and written out for easy use. Schedules for several thicknesses and specialty products (e.g. squares, handle stock, gunstock blanks) are given for many species. The majority of the schedules are from the world literature...

  3. ballistic performance of a quenched and tempered steel against ...

    African Journals Online (AJOL)

    eobe

    Author, Tel: +234-805-671-5551. BALLISTIC PERFORMANCE OF A QUENCHED AND TEMPERED STEEL. AGAINST 7.62MM CALIBRE. AGAINST 7.62MM CALIBRE PROJECTILE. PROJECTILE. PROJECTILE. O. M. Sanusi1 and J. O. Akindapo2. 1RESEARCH AND DEVELOPMENT CENTRE, DEFENCE INDUSTRIES ...

  4. The Fracture Process of Tempered Soda-Lime-Silica Glass

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Olesen, John Forbes; Stang, Henrik

    2009-01-01

    This work presents experimental observations of the characteristic fracture process of tempered glass. Square specimens with a side length of 300 mm, various thicknesses and a residual stress state characterized by photoelastic measurements were used. Fracture was initiated using a 2.5 mm diamond...

  5. Mixed livestock grazing in diverse temperate and semi-arid ...

    African Journals Online (AJOL)

    Concerns for product quality, uniformity and continuity and for animal welfare will increasingly drive production processes. In this paper, the potential of mixed grazing for higher output of quality animal products, within these constraints, is assessed under both temperate and semi-arid conditions. Complementary ...

  6. Conservation importance of early post-disturbance temperate forests

    Science.gov (United States)

    Charles Kwit; David I. King; Beverly Collins; Mark E. Swanson

    2014-01-01

    The early post-disturbance stage of temperate forest succession (also referred to as 'early-seral' or 'early-successional' forest) has been the subject of interest and debate. Often thought of as an ephemeral (and often disorganized) state of eventual closed-canopy systems, its direct and immediate role in conservation traditionally has been ignored...

  7. Effects of temperate agriculture on neotropical migrant landbirds

    Science.gov (United States)

    Nicholas L. Rodenhouse; Louis B. Best; Raymond J. O' Connor; Eric K. Bollinger

    1993-01-01

    The ecology of Neotropical migrant landbirds in temperate farmland is reviewed to develop management recommendations for the conservation of migrants. Migrants constitute about 71% of bird species using farmland and 86% of bird species nesting there. The number and abundances of Neotropical migrants using farmland are greatest in uncultivated edges with trees and...

  8. Temperate non-breeding surveys - a key to shorebird conservation

    Science.gov (United States)

    Sue Thomas

    2005-01-01

    Completion of the United States and Canadian shorebird conservation plans recently identified and prioritized shorebird monitoring, management, and conservation needs in the Western Hemisphere. We present an emerging approach to monitor shorebird use of temperate non-breeding areas under the Program for Regional and International Shorebird Monitoring (PRISM). This...

  9. Tempered Water Lower Port Connector Structural Analysis Verification

    Energy Technology Data Exchange (ETDEWEB)

    CREA, B.A.

    2000-05-05

    Structural analysis of the lower port connection of the Tempered Water System of the Cold Vacuum Drying Facility was performed. Subsequent detailed design changes to enhance operability resulted in the need to re-evaluate the bases of the original analysis to verify its continued validity. This evaluation is contained in Appendix A of this report. The original evaluation is contained in Appendix B.

  10. Late Glacial and Holocene Paleoliminology of two temperate lakes ...

    Indian Academy of Sciences (India)

    The stable carbon isotope (13C) and elemental C/N ratios in Total Organic Carbon (TOC) extracted from radiometrically dated cores from two Midwestern USA lakes were determined to investigate the factors that control these values in temperate lakes. The range of 13C values ( -26 to -32%) and C/N ratios (mean value ...

  11. Temperate forest dynamics and carbon storage: A 26-year case ...

    African Journals Online (AJOL)

    Temperate forests are globally important carbon stores that are, in the face of recent improvements in their conservation, likely to increase their storage capacity in the future. Despite this, these ecosystems are poorly understood, especially over longer time periods. To remedy this and to better understand these important ...

  12. Effect of tempering after cryogenic treatment of tungsten carbide ...

    Indian Academy of Sciences (India)

    Cryogenic treatment is a recent advancement in the field of machining to improve the properties of cutting tool materials. Tungsten carbide is the most commonly used cutting tool material in the industry and the technique can also be extended to it. Although the importance of tempering after cryogenic treatment has been ...

  13. Joint measurement of risk aversion, prudence, and temperance

    NARCIS (Netherlands)

    Ebert, S.; Wiesen, D.

    Risk aversion—but also the higher-order risk preferences of prudence and temperance—are fundamental concepts in the study of economic decision making. We propose a method to jointly measure the intensity of risk aversion, prudence, and temperance. Our theoretical approach is to define risk

  14. Root development of fodder radish and winter wheat before winter in relation to uptake of nitrogen

    DEFF Research Database (Denmark)

    Wahlström, Ellen Margrethe; Hansen, Elly Møller; Mandel, A.

    2015-01-01

    occurred. Quantitative data is missing on N leaching of a catch crop compared to a winter cereal in a conventional cereal-based cropping system. The aim of the study was to investigate whether fodder radish (Raphanus sativus L.) (FR) would be more efficient than winter wheat (Triticum aestivum L.) (WW...

  15. Frequency and distribution of winter melt events from passive microwave satellite data in the pan-Arctic, 1988-2013

    Science.gov (United States)

    Wang, Libo; Toose, Peter; Brown, Ross; Derksen, Chris

    2016-11-01

    This study presents an algorithm for detecting winter melt events in seasonal snow cover based on temporal variations in the brightness temperature difference between 19 and 37 GHz from satellite passive microwave measurements. An advantage of the passive microwave approach is that it is based on the physical presence of liquid water in the snowpack, which may not be the case with melt events inferred from surface air temperature data. The algorithm is validated using in situ observations from weather stations, snow pit measurements, and a surface-based passive microwave radiometer. The validation results indicate the algorithm has a high success rate for melt durations lasting multiple hours/days and where the melt event is preceded by warm air temperatures. The algorithm does not reliably identify short-duration events or events that occur immediately after or before periods with extremely cold air temperatures due to the thermal inertia of the snowpack and/or overpass and resolution limitations of the satellite data. The results of running the algorithm over the pan-Arctic region (north of 50° N) for the 1988-2013 period show that winter melt events are relatively rare, totaling less than 1 week per winter over most areas, with higher numbers of melt days (around two weeks per winter) occurring in more temperate regions of the Arctic (e.g., central Québec and Labrador, southern Alaska and Scandinavia). The observed spatial pattern is similar to winter melt events inferred with surface air temperatures from the ERA-Interim (ERA-I) and Modern Era-Retrospective Analysis for Research and Applications (MERRA) reanalysis datasets. There was little evidence of trends in winter melt event frequency over 1988-2013 with the exception of negative trends over northern Europe attributed to a shortening of the duration of the winter period. The frequency of winter melt events is shown to be strongly correlated to the duration of winter period. This must be taken into

  16. Payment mechanisms for winter road maintenance services

    Directory of Open Access Journals (Sweden)

    Adel Abdi

    2013-12-01

    Full Text Available In countries with severe winters a major part of the annual budget for road maintenance is allocated on performance of winter road maintenance tasks. Finding appropriate remuneration forms to compensate entrepreneurs for performed road measures during winter is not an easy task in order to minimise or eliminate disputes and satisfy both client organisations and contractors. On the other hand improper reimbursement models lead either to the client’s annual budget imbalance due to unnecessary cost overruns or affect contractor’s cash-flow. Such cases in turn affect just-in-time winter road maintenance and then traffic safety. To solve such problems, a number of countries in cold regions like Sweden have developed different remuneration models based more on weather data called Weather Index. Therefore the objective of this paper is to investigate and evaluate the payment models applied in Sweden. The study uses a number of approaches namely; domestic questionnaire survey, analysis of a number of contract documents, a series of meetings with the project managers and an international benchmarking. The study recognised four remuneration models for winter maintenance service of which one based on weather data statistics. The study reveals the payment model based on weather data statistics is only applied for the roads with higher traffic flow and the model generates most uncertainty.

  17. Soil moisture dynamics modeling considering multi-layer root zone.

    Science.gov (United States)

    Kumar, R; Shankar, V; Jat, M K

    2013-01-01

    The moisture uptake by plant from soil is a key process for plant growth and movement of water in the soil-plant system. A non-linear root water uptake (RWU) model was developed for a multi-layer crop root zone. The model comprised two parts: (1) model formulation and (2) moisture flow prediction. The developed model was tested for its efficiency in predicting moisture depletion in a non-uniform root zone. A field experiment on wheat (Triticum aestivum) was conducted in the sub-temperate sub-humid agro-climate of Solan, Himachal Pradesh, India. Model-predicted soil moisture parameters, i.e., moisture status at various depths, moisture depletion and soil moisture profile in the root zone, are in good agreement with experiment results. The results of simulation emphasize the utility of the RWU model across different agro-climatic regions. The model can be used for sound irrigation management especially in water-scarce humid, temperate, arid and semi-arid regions and can also be integrated with a water transport equation to predict the solute uptake by plant biomass.

  18. Carbon stock and carbon turnover in boreal and temperate forests - Integration of remote sensing data and global vegetation models

    Science.gov (United States)

    Thurner, Martin; Beer, Christian; Carvalhais, Nuno; Forkel, Matthias; Tito Rademacher, Tim; Santoro, Maurizio; Tum, Markus; Schmullius, Christiane

    2016-04-01

    Long-term vegetation dynamics are one of the key uncertainties of the carbon cycle. There are large differences in simulated vegetation carbon stocks and fluxes including productivity, respiration and carbon turnover between global vegetation models. Especially the implementation of climate-related mortality processes, for instance drought, fire, frost or insect effects, is often lacking or insufficient in current models and their importance at global scale is highly uncertain. These shortcomings have been due to the lack of spatially extensive information on vegetation carbon stocks, which cannot be provided by inventory data alone. Instead, we recently have been able to estimate northern boreal and temperate forest carbon stocks based on radar remote sensing data. Our spatially explicit product (0.01° resolution) shows strong agreement to inventory-based estimates at a regional scale and allows for a spatial evaluation of carbon stocks and dynamics simulated by global vegetation models. By combining this state-of-the-art biomass product and NPP datasets originating from remote sensing, we are able to study the relation between carbon turnover rate and a set of climate indices in northern boreal and temperate forests along spatial gradients. We observe an increasing turnover rate with colder winter temperatures and longer winters in boreal forests, suggesting frost damage and the trade-off between frost adaptation and growth being important mortality processes in this ecosystem. In contrast, turnover rate increases with climatic conditions favouring drought and insect outbreaks in temperate forests. Investigated global vegetation models from the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), including HYBRID4, JeDi, JULES, LPJml, ORCHIDEE, SDGVM, and VISIT, are able to reproduce observation-based spatial climate - turnover rate relationships only to a limited extent. While most of the models compare relatively well in terms of NPP, simulated

  19. Coupled Effects of Climatic and Socio-economic Factors on Winter Cropping in India

    Science.gov (United States)

    Jain, M.; Mondal, P.; Galford, G. L.; DeFries, R. S.

    2015-12-01

    India is predicted to be one of the most vulnerable regions in terms of agricultural sensitivity to future climate changes. Approximately 69% of India's population is rural, and over 55% of the working population relies on agriculture for sustenance and livelihoods. Indian smallholder farmers who own less than 2 ha of farmland represent 78% of the total Indian farmers and produce 41% of the country's food crops. These smallholder farmers are among some of the most vulnerable communities to climatic and economic changes due to limited access to technology, infrastructure, markets, and institutional or financial support in the case of adverse climatic events. Baseline information on agricultural sensitivity to climate variability will provide useful information for regional-level, and eventually state- and national-level, strategies and policies that promote adaption to climate variability. We use a decade of remote sensing analysis of cropping patterns and climatic factors along with census data for irrigation and demographic factors to understand winter cropping trajectories across agro-ecological zones in India. Findings from multiple agro-ecological zones indicate that there are three primary trajectories in winter cropping in India - increasing, fluctuating, and decreasing. In the Central Indian Highlands, for example, the most dominant trend is that of fluctuating cropped area, ranging between ~37,300 km2 in 2010 and ~21,100 km2 in 2013, which is associated with village-level access to irrigation and local labor dynamics. Clay soil type and increasing irrigation coverage were associated with intensification. Yet, suitable soil type and access to irrigation do not reduce vulnerability to high daytime temperatures that is negatively associated with winter crop cover. With pronounced winter warming projected in the coming decades, effective adaptation by smallholder farmers would require additional strategies, such as access to fine-scale temperature forecasts

  20. Root Apex Transition Zone as Oscillatory Zone

    Directory of Open Access Journals (Sweden)

    Frantisek Baluska

    2013-10-01

    Full Text Available Root apex of higher plants shows very high sensitivity to environmental stimuli. The root cap acts as the most prominent plant sensory organ; sensing diverse physical parameters such as gravity, light, humidity, oxygen and critical inorganic nutrients. However, the motoric responses to these stimuli are accomplished in the elongation region. This spatial discrepancy was solved when we have discovered and characterized the transition zone which is interpolated between the apical meristem and the subapical elongation zone. Cells of this zone are very active in the cytoskeletal rearrangements, endocytosis and endocytic vesicle recycling, as well as in electric activities. Here we discuss the oscillatory nature of the transition zone which, together with several other features of this zone, suggest that it acts as some kind of command centre. In accordance with the early proposal of Charles and Francis Darwins, cells of this root zone receive sensory information from the root cap and instruct the motoric responses of cells in the elongation zone.

  1. Vegetation zones shift in changing climate

    Science.gov (United States)

    Belda, Michal; Halenka, Tomas; Kalvova, Jaroslava; Holtanova, Eva

    2016-04-01

    between the selected types can be studied as well providing the information on climate change signal. The shift of the boundary between the boreal zone and continental temperate zone to the north is clearly seen in most simulations as well as eastern move of the boundary of the maritime and continental type of temperate zone. However, there can be quite clear problem with model biases in climate types association.

  2. Groundwater flow modelling of periods with temperate climate conditions - Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Swan, David (Serco Technical Consulting Services (United Kingdom)); Marsic, Niko (Kemakta Konsult AB (Sweden)); Follin, Sven (SF GeoLogic AB (Sweden))

    2010-11-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different climate conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Forsmark site during temperate conditions; i.e. from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 12,000 AD. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a hydrogeological base case (reference case conceptualisation) and then in an examination of various areas of uncertainty within the current understanding by a series of model variants. The hydrogeological base case models at three different scales, 'repository', 'site' and 'regional', make use of continuous porous medium (CPM), equivalent continuous porous medium (ECPM) and discrete fracture network (DFN) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

  3. The engineering approach to winter sports

    CERN Document Server

    Cheli, Federico; Maldifassi, Stefano; Melzi, Stefano; Sabbioni, Edoardo

    2016-01-01

    The Engineering Approach to Winter Sports presents the state-of-the-art research in the field of winter sports in a harmonized and comprehensive way for a diverse audience of engineers, equipment and facilities designers, and materials scientists. The book examines the physics and chemistry of snow and ice with particular focus on the interaction (friction) between sports equipment and snow/ice, how it is influenced by environmental factors, such as temperature and pressure, as well as by contaminants and how it can be modified through the use of ski waxes or the microtextures of blades or ski soles. The authors also cover, in turn, the different disciplines in winter sports:  skiing (both alpine and cross country), skating and jumping, bob sledding and skeleton, hockey and curling, with attention given to both equipment design and on the simulation of gesture and  track optimization.

  4. Risk management model of winter navigation operations.

    Science.gov (United States)

    Valdez Banda, Osiris A; Goerlandt, Floris; Kuzmin, Vladimir; Kujala, Pentti; Montewka, Jakub

    2016-07-15

    The wintertime maritime traffic operations in the Gulf of Finland are managed through the Finnish-Swedish Winter Navigation System. This establishes the requirements and limitations for the vessels navigating when ice covers this area. During winter navigation in the Gulf of Finland, the largest risk stems from accidental ship collisions which may also trigger oil spills. In this article, a model for managing the risk of winter navigation operations is presented. The model analyses the probability of oil spills derived from collisions involving oil tanker vessels and other vessel types. The model structure is based on the steps provided in the Formal Safety Assessment (FSA) by the International Maritime Organization (IMO) and adapted into a Bayesian Network model. The results indicate that ship independent navigation and convoys are the operations with higher probability of oil spills. Minor spills are most probable, while major oil spills found very unlikely but possible. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Ectomycorrhizas in vitro between Tricholoma matsutake, a basidiomycete that associates with Pinaceae, and Betula platyphylla var. japonica, an early-successional birch species, in cool-temperate forests.

    Science.gov (United States)

    Murata, Hitoshi; Yamada, Akiyoshi; Maruyama, Tsuyoshi; Neda, Hitoshi

    2015-04-01

    Tricholoma matsutake is an ectomycorrhizal basidiomycete that associates with Pinaceae in the Northern Hemisphere and produces prized "matsutake" mushrooms. We questioned whether the symbiont could associate with a birch that is an early-successional species in boreal, cool-temperate, or subalpine forests. In the present study, we demonstrated that T. matsutake can form typical ectomycorrhizas with Betula platyphylla var. japonica; the associations included a Hartig net and a thin but distinct fungal sheath, as well as the rhizospheric mycelial aggregate "shiro" that is required for fruiting in nature. The in vitro shiro also emitted a characteristic aroma. This is the first report of an ectomycorrhizal formation between T. matsutake and a deciduous broad-leaved tree in the boreal or cool-temperate zones that T. matsutake naturally inhabits.

  6. Managed nutrient reduction impacts on nutrient concentrations, water clarity, primary production, and hypoxia in a north temperate estuary

    Science.gov (United States)

    Oviatt, Candace; Smith, Leslie; Krumholz, Jason; Coupland, Catherine; Stoffel, Heather; Keller, Aimee; McManus, M. Conor; Reed, Laura

    2017-12-01

    Except for the Providence River and side embayments like Greenwich Bay, Narragansett Bay can no longer be considered eutrophic. In summer 2012 managed nitrogen treatment in Narragansett Bay achieved a goal of reducing effluent dissolved inorganic nitrogen inputs by over 50%. Narragansett Bay represents a small northeast US estuary that had been heavily loaded with sewage effluent nutrients since the late 1800s. The input reduction was reflected in standing stock nutrients resulting in a statistically significant 60% reduction in concentration. In the Providence River estuary, total nitrogen decreased from 100 μm to about 40 μm, for example. We tested four environmental changes that might be associated with the nitrogen reduction. System apparent production was significantly decreased by 31% and 45% in the upper and mid Bay. Nutrient reductions resulted in statistically improved water clarity in the mid and upper Bay and in a 34% reduction in summer hypoxia. Nitrogen reduction also reduced the winter spring diatom bloom; winter chlorophyll levels after nutrient reduction have been significantly lower than before the reduction. The impact on the Bay will continue to evolve over the next few years and be a natural experiment for other temperate estuaries that will be experiencing nitrogen reduction. To provide perspective we review factors effecting hypoxia in other estuaries with managed nutrient reduction and conclude that, as in Narragansett Bay, physical factors can be as important as nutrients. On a positive note managed nutrient reduction has mitigated further deterioration in most estuaries.

  7. Winter camp for pre-school children

    OpenAIRE

    Golc, Mateja

    2017-01-01

    This thesis details the importance of physical activity for a healthy development of pre-school children in all areas of their development. The focus is placed mainly on outdoor physical activity, in all seasons of the year and in all types of weather. Also highlighted is the importance of outdoor physical activity, stretching over several days, in the form of a winter camp for pre-school children. Pre-school teachers, who take over the organisation of a winter camp, face a challenging task, ...

  8. Nuclear winter: The evidence and the risks

    Energy Technology Data Exchange (ETDEWEB)

    Greene, O.

    1985-01-01

    Global concern over nuclear extinction, centered on the holocaust itself, now has turned to the more terrifying consequences of a post-war nuclear winter: ''the long-term effects - destruction of the environment, spread of epidemic diseases, contamination by radioactivity, and ... collapse of agriculture-(that) would spread famine and death to every country.'' Nuclear Winter, the latest in a series of studies by a number of different groups is clinical, analytical, systematic, and detailed. Two physicists and biologist analyze the effects on the climate, plants, animals, and living systems; the human costs; the policy implications.

  9. Zoning Districts - Volusia County HUB Zones

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Historically Underutilized Business (HUB) Zones in Volusia County. Go to http://www.sba.gov/hubzone or contact the Department of Economic Development (386) 248-8048...

  10. Numerical simulation of a rare winter hailstorm event over Delhi, India on 17 January 2013

    KAUST Repository

    Chevuturi, A.

    2014-12-19

    This study analyzes the cause of the rare occurrence of a winter hailstorm over New Delhi/NCR (National Capital Region), India. The absence of increased surface temperature or low level of moisture incursion during winter cannot generate the deep convection required for sustaining a hailstorm. Consequently, NCR shows very few cases of hailstorms in the months of December-January-February, making the winter hail formation a question of interest. For this study, a recent winter hailstorm event on 17 January 2013 (16:00–18:00 UTC) occurring over NCR is investigated. The storm is simulated using the Weather Research and Forecasting (WRF) model with the Goddard Cumulus Ensemble (GCE) microphysics scheme with two different options: hail and graupel. The aim of the study is to understand and describe the cause of hailstorm event during over NCR with a comparative analysis of the two options of GCE microphysics. Upon evaluating the model simulations, it is observed that the hail option shows a more similar precipitation intensity with the Tropical Rainfall Measuring Mission (TRMM) observation than the graupel option does, and it is able to simulate hail precipitation. Using the model-simulated output with the hail option; detailed investigation on understanding the dynamics of hailstorm is performed. The analysis based on a numerical simulation suggests that the deep instability in the atmospheric column led to the formation of hailstones as the cloud formation reached up to the glaciated zone promoting ice nucleation. In winters, such instability conditions rarely form due to low level available potential energy and moisture incursion along with upper level baroclinic instability due to the presence of a western disturbance (WD). Such rare positioning is found to be lowering the tropopause with increased temperature gradient, leading to winter hailstorm formation.

  11. Independently founded populations of Sclerotinia sclerotiorum from a tropical and a temperate region have similar genetic structure.

    Science.gov (United States)

    Lehner, Miller S; de Paula Júnior, Trazilbo J; Del Ponte, Emerson M; Mizubuti, Eduardo S G; Pethybridge, Sarah J

    2017-01-01

    Sclerotinia sclerotiorum populations from tropical agricultural zones have been suggested to be more variable compared to those from temperate zones. However, no data were available comparing populations from both zones using the same set of markers. In this study, we compared S. sclerotiorum populations from the United States of America (USA, temperate) and southeast Brazil (tropical) using the frequency of mycelial compatibility groups (MCGs) and 13 microsatellite (SSR) markers. Populations were sourced from diseased plants within leguminous crops in New York, USA (NY; n = 78 isolates), and Minas Gerais State, Brazil (MG; n = 109). Twenty MCGs were identified in NY and 14 were previously reported in MG. The effective number of genotypes based on Hill's number of order 0, which corresponded to the number of multilocus genotypes (MLGs) were 22 (95% CI = 15.6-28.4) and 24 (95% CI = 18.9-29.1) in NY and MG, respectively. Clonal fractions of MLGs were 71.8% (NY) and 78.0% (MG). The effective number of genotypes based on Hill's number of orders 1 and 2 in NY were 8.9 (95% CI = 5.2-12.6) and 4.4 (95% CI = 2.6-6.1), respectively. For MG these indices were 11.4 (95% CI = 8.7-14.1) and 7.1 (95% CI = 5.1-9.0), respectively. There were no significant differences of allelic richness, private allelic richness, gene diversity, effective number of alleles and genotype evenness between the NY and MG populations. The populations were differentiated, with 29% of total variance attributed to differences between them and G''ST and Jost's D indices higher than 0.50. Cluster analysis revealed dissimilarity higher than 80% among most MLGs from both populations. Different alleles segregated in the populations but both had similar levels of genotypic variability.

  12. Independently founded populations of Sclerotinia sclerotiorum from a tropical and a temperate region have similar genetic structure.

    Directory of Open Access Journals (Sweden)

    Miller S Lehner

    Full Text Available Sclerotinia sclerotiorum populations from tropical agricultural zones have been suggested to be more variable compared to those from temperate zones. However, no data were available comparing populations from both zones using the same set of markers. In this study, we compared S. sclerotiorum populations from the United States of America (USA, temperate and southeast Brazil (tropical using the frequency of mycelial compatibility groups (MCGs and 13 microsatellite (SSR markers. Populations were sourced from diseased plants within leguminous crops in New York, USA (NY; n = 78 isolates, and Minas Gerais State, Brazil (MG; n = 109. Twenty MCGs were identified in NY and 14 were previously reported in MG. The effective number of genotypes based on Hill's number of order 0, which corresponded to the number of multilocus genotypes (MLGs were 22 (95% CI = 15.6-28.4 and 24 (95% CI = 18.9-29.1 in NY and MG, respectively. Clonal fractions of MLGs were 71.8% (NY and 78.0% (MG. The effective number of genotypes based on Hill's number of orders 1 and 2 in NY were 8.9 (95% CI = 5.2-12.6 and 4.4 (95% CI = 2.6-6.1, respectively. For MG these indices were 11.4 (95% CI = 8.7-14.1 and 7.1 (95% CI = 5.1-9.0, respectively. There were no significant differences of allelic richness, private allelic richness, gene diversity, effective number of alleles and genotype evenness between the NY and MG populations. The populations were differentiated, with 29% of total variance attributed to differences between them and G''ST and Jost's D indices higher than 0.50. Cluster analysis revealed dissimilarity higher than 80% among most MLGs from both populations. Different alleles segregated in the populations but both had similar levels of genotypic variability.

  13. Standardized precipitation index zones for Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Giddings, L.; Soto, M. [Instituto de Ecologia, A.C., Xalapa, Veracruz (Mexico); Rutherford, B.M.; Maarouf, A. [Faculty of Environmental Studies, York University, Toronto, Ontario (Canada)

    2005-01-01

    Precipitation zone systems exists for Mexico based on seasonality, quantity of precipitation, climates and geographical divisions, but none are convenient for the study of the relation of precipitation with phenomena such as El nino. An empirical set of seven exclusively Mexican and six shared zones was derived from three series of Standardized Precipitation Index (SPI) images, from 1940 through 1989: a whole year series (SPI-12) of 582 monthly images, a six month series (SPI-6) of 50 images for winter months (November through April), and a six month series (SPI-6) of 50 images for summer months (May through October). By examination of principal component and unsupervised classification images, it was found that all three series had similar zones. A set of basic training fields chosen from the principal component images was used to classify all three series. The resulting thirteen zones, presented in this article, were found to be approximately similar, varying principally at zones edges. A set of simple zones defined by just a few vertices can be used for practical operations. In general the SPI zones are homogeneous, with almost no mixture of zones and few outliers of one zone in the area of others. They are compared with a previously published map of climatic regions. Potential applications for SPI zones are discussed. [Spanish] Existen varios sistemas de zonificacion de Mexico basados en la estacionalidad, cantidad de precipitacion, climas y divisiones geograficas, pero ninguno es conveniente para el estudio de la relacion de la precipitacion con fenomenos tales como El Nino. En este trabajo se presenta un conjunto de siete zonas empiricas exclusivamente mexicanas y seis compartidas, derivadas de tres series de imagenes de SPI (Indice Estandarizado de la Precipitacion), desde 1940 a 1989: una serie de 582 imagenes mensuales (SPI-12), una series de 50 imagenes (SPI-6) de meses de invierno (noviembre a abril), y otra de 50 imagenes (SPI-6) de meses de verano

  14. Does stratosphereic sudden warming occur more frequently during ENSO winters than during normal winters?

    Science.gov (United States)

    Son, Seok-Woo; Song, Kanghyun

    2017-04-01

    Stratospheric sudden warming (SSW) events exhibit pronounced interannual variability. Based on WMO definition of SSW, it has been suggested that SSW events occur more preferably during El Niño-Southern Oscillation (ENSO) winters (both El Niño and La Niña winters) than during normal winters. This nonlinear relationship is re-examined here by considering six different definitions of SSW. For all definitions, SSW events are detected more frequently during El Niño winters than during normal winters, in consistent with an enhanced planetary-scale wave activity. However, a systematic relationship is not found during La Niña winters. While two SSW definitions, including WMO definition, show an increased SSW frequency during La Niña winters, other definitions show no change or even a reduced SSW frequency. This result is insensitive to the choice of reanalysis datasets and ENSO index, indicating that the reported ENSO-SSW relationship is not robust but dependent on the details of SSW definition.

  15. Quantifying the risks of winter damage on overwintering crops under future climates: Will low-temperature damage be more likely in warmer climates?

    Science.gov (United States)

    Vico, G.; Weih, M.

    2014-12-01

    Autumn-sown crops act as winter cover crop, reducing soil erosion and nutrient leaching, while potentially providing higher yields than spring varieties in many environments. Nevertheless, overwintering crops are exposed for longer periods to the vagaries of weather conditions. Adverse winter conditions, in particular, may negatively affect the final yield, by reducing crop survival or its vigor. The net effect of the projected shifts in climate is unclear. On the one hand, warmer temperatures may reduce the frequency of low temperatures, thereby reducing damage risk. On the other hand, warmer temperatures, by reducing plant acclimation level and the amount and duration of snow cover, may increase the likelihood of damage. Thus, warmer climates may paradoxically result in more extensive low temperature damage and reduced viability for overwintering plants. The net effect of a shift in climate is explored by means of a parsimonious probabilistic model, based on a coupled description of air temperature, snow cover, and crop tolerable temperature. Exploiting an extensive dataset of winter wheat responses to low temperature exposure, the risk of winter damage occurrence is quantified under conditions typical of northern temperate latitudes. The full spectrum of variations expected with climate change is explored, quantifying the joint effects of alterations in temperature averages and their variability as well as shifts in precipitation. The key features affecting winter wheat vulnerability to low temperature damage under future climates are singled out.

  16. Winter cooling in the northern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Prasad, T.G.

    forcing that leads to the observed high productivity during winter in the northern Arabian Sea. The weak northerly winds and increased solar insolation during the inter-monsoon period, led to the development of a highly stratified upper layer with warm sea...

  17. Highway user expectations for ITD winter maintenance.

    Science.gov (United States)

    2014-07-01

    Providing a high Level of Service (LOS) to ensure the safety and mobility for the traveling public is a key objective for winter : maintenance operations. The goal of this research was to obtain a better understanding of Idaho highway users expect...

  18. Music Activities for Lemonade in Winter

    Science.gov (United States)

    Cardany, Audrey Berger

    2014-01-01

    "Lemonade in Winter: A Book About Two Kids Counting Money" is a children's book about math; however, when sharing it in the music classroom, street cries and clapping games emerge. Jenkins' and Karas' book provides a springboard to lessons addressing several music elements, including form, tempo, and rhythm, as well as…

  19. Registration of ‘Secretariat’ winter barley

    Science.gov (United States)

    Secretariat’ (PI 673931) is a six-row hulled winter feed barley (Hordeum vulgare L.) cultivar developed by the Virginia Agricultural Experiment Station and released in May 2014. Secretariat, formerly designated VA08B-85, was derived from the cross VA00B-199 / VA00B-259 and was developed using a mod...

  20. Registration of 'Sunshine' Hard White Winter Wheat

    Science.gov (United States)

    ’Sunshine’ (Reg. No. CV-XXXX, PI 674741) hard white winter wheat (Triticum aestivum L.) was developed by the Colorado Agricultural Experiment Station and released in August 2014 through a marketing agreement with the Colorado Wheat Research Foundation. In addition to researchers at Colorado State Un...

  1. Stay Safe and Healthy This Winter!

    Centers for Disease Control (CDC) Podcasts

    2010-11-23

    In this podcast for kids, the Kidtastics offer some simple ways to stay safe and healthy during the winter holiday season.  Created: 11/23/2010 by CDC Office of Women’s Health.   Date Released: 11/23/2010.

  2. How marketers handled deliveries last winter

    Energy Technology Data Exchange (ETDEWEB)

    1984-10-01

    A special study on how fuel oil marketers handled deliveries last winter is presented. A questionnaire was sent to the marketers asking how many fuel oil trucks they had, how penalties for small deliveries are assessed, and if many customers are calling for a summer fill. The results of the questionnaire are presented.

  3. Winter Video Series Coming in January | Poster

    Science.gov (United States)

    The Scientific Library’s annual Summer Video Series was so successful that it will be offering a new Winter Video Series beginning in January. For this inaugural event, the staff is showing the eight-part series from National Geographic titled “American Genius.” 

  4. Nuclear winter - Physics and physical mechanisms

    Science.gov (United States)

    Turco, R. P.; Toon, O. B.; Pollack, J. B.; Ackerman, T. P.; Sagan, C.

    1991-01-01

    The basic physics of the environmental perturbations caused by multiple nuclear detonations is explored, summarizing current knowledge of the possible physical, chemical, and biological impacts of nuclear war. Emphasis is given to the impact of the bomb-generated smoke (soot) particles. General classes of models that have been used to simulate nuclear winter are examined, using specific models as examples.

  5. Estimating inter-annual variability in winter wheat sowing dates from satellite time series in Camargue, France

    Science.gov (United States)

    Manfron, Giacinto; Delmotte, Sylvestre; Busetto, Lorenzo; Hossard, Laure; Ranghetti, Luigi; Brivio, Pietro Alessandro; Boschetti, Mirco

    2017-05-01

    Crop simulation models are commonly used to forecast the performance of cropping systems under different hypotheses of change. Their use on a regional scale is generally constrained, however, by a lack of information on the spatial and temporal variability of environment-related input variables (e.g., soil) and agricultural practices (e.g., sowing dates) that influence crop yields. Satellite remote sensing data can shed light on such variability by providing timely information on crop dynamics and conditions over large areas. This paper proposes a method for analyzing time series of MODIS satellite data in order to estimate the inter-annual variability of winter wheat sowing dates. A rule-based method was developed to automatically identify a reliable sample of winter wheat field time series, and to infer the corresponding sowing dates. The method was designed for a case study in the Camargue region (France), where winter wheat is characterized by vernalization, as in other temperate regions. The detection criteria were chosen on the grounds of agronomic expertise and by analyzing high-confidence time-series vegetation index profiles for winter wheat. This automatic method identified the target crop on more than 56% (four-year average) of the cultivated areas, with low commission errors (11%). It also captured the seasonal variability in sowing dates with errors of ±8 and ±16 days in 46% and 66% of cases, respectively. Extending the analysis to the years 2002-2012 showed that sowing in the Camargue was usually done on or around November 1st (±4 days). Comparing inter-annual sowing date variability with the main local agro-climatic drivers showed that the type of preceding crop and the weather conditions during the summer season before the wheat sowing had a prominent role in influencing winter wheat sowing dates.

  6. Winter severity and snowiness and their multiannual variability in the Karkonosze Mountains and Jizera Mountains

    Science.gov (United States)

    Urban, Grzegorz; Richterová, Dáša; Kliegrová, Stanislava; Zusková, Ilona; Pawliczek, Piotr

    2017-09-01

    This paper analyses winter severity and snow conditions in the Karkonosze Mountains and Jizera Mountains and examines their long-term trends. The analysis used modified comprehensive winter snowiness (WSW) and winter severity (WOW) indices as defined by Paczos (1982). An attempt was also made to determine the relationship between the WSW and WOW indices. Measurement data were obtained from eight stations operated by the Institute of Meteorology and Water Management - National Research Institute (IMGW-PIB), from eight stations operated by the Czech Hydrological and Meteorological Institute (CHMI) and also from the Meteorological Observatory of the University of Wrocław (UWr) on Mount Szrenica. Essentially, the study covered the period from 1961 to 2015. In some cases, however, the period analysed was shorter due to the limited availability of data, which was conditioned, inter alia, by the period of operation of the station in question, and its type. Viewed on a macroscale, snow conditions in the Karkonosze Mountains and Jizera Mountains (in similar altitude zones) are clearly more favourable on southern slopes than on northern ones. In the study area, negative trends have been observed with respect to both the WSW and WOW indices—winters have become less snowy and warmer. The correlation between the WOW and WSW indices is positive. At stations with northern macroexposure, WOW and WSW show greater correlation than at ones with southern macroexposure. This relationship is the weakest for stations that are situated in the upper ranges (Mount Śnieżka and Mount Szrenica).

  7. Characterization of Microstructure and Texture of 13Cr4Ni Martensitic Stainless Steel Weld Before and After Tempering =

    Science.gov (United States)

    Mokhtabad Amrei, Mohsen

    13Cr4Ni martensitic stainless steels are known for their outstanding performances in the hydroelectric industry, where they are mainly used in the construction of turbine components. Considering the size and geometry of turbine runners and blades, multi-pass welding procedures are commonly used in the fabrication and repair of such turbines. The final microstructure and mechanical properties of the weld are sensitive to the welding process parameters and thermal history. In the case of 13Cr4Ni steel, the thermal cycles imposed by the multi-pass welding operation have significant effects on the complex weld microstructure. Additionally, post-weld heat treatments are commonly used to reduce weld heterogeneity and improve the material's mechanical properties by tempering the microstructure and by forming a "room-temperature-stable austenite." In the first phase of this research, the microstructures and crystallographic textures of aswelded single-pass and double-pass welds were studied as a basis to studying the more complex multi-pass weld microstructure. This study found that the maximum hardness is obtained in high temperature heat affected zone inside the base metal. In particular, the results showed that the heat cycle exposed by the second pass increases the hardness of the previous pass because it produces a finer martensite microstructure. In areas of heat affected zone, a tempering effect is reported from 3 up to 6 millimeters far from the fusion line. Finding austenite phase in these areas are matter of interest and it can be indicative of the microstructure complexity of multi-pass welds. In the second phase of research, the microstructure of multi-pass welds was found to be more heterogeneous than that of single- and double-pass welds. Any individual pass in a multi-pass weld consists of several regions formed by adjacent weld passes heat cycle. Results showed that former austenite grains modification occurred in areas close to the subsequent weld passes

  8. Sensitivity of soil permafrost to winter warming: Modeled impacts of climate change.

    Science.gov (United States)

    Bouskill, N.; Riley, W. J.; Mekonnen, Z. A.; Grant, R.

    2016-12-01

    High-latitude tundra soils are warming at nearly twice the rate of temperate ecosystems. Changes in temperature and soil moisture can feedback on the processes controlling the carbon balance of tundra soils by altering plant community composition and productivity and microbial decomposition rates. Recent field manipulation experiments have shown that elevated soil and air temperatures can stimulate both gross primary productivity and ecosystem respiration. However, the observed soil carbon gains following summer time stimulation of plant productivity have been more than offset by elevated decomposition rates during the rest of the year, and particularly over winter. A critical uncertainty is whether these short-term responses also represent the long-term trajectory of tundra ecosystems under chronic disturbance. Herein we employ a mechanistic land-model (ecosys) that represents many of the key above- and belowground processes regulating the carbon balance of tundra soils to simulate a winter warming experiment at Eight Mile Lake, Alaska. Using this model we examined the short-term (5 - 10 year) influence of soil warming through the wintertime by mimicking the accumulation of a deeper snow pack. This deeper snow pack was removed to a height equal to that of the snow pack over control plots prior to snow melt. We benchmarked the model using physical and biological measurements made over the course of a six-year experiment at the site. The model accurately represented the effect of the experimental manipulation on thaw depth, N mineralization, winter respiration, and ecosystem gross and net primary production. After establishing confidence in the modeled short-term responses, we extend the same chronic disturbance to 2050 to examine the long-term response of the plant and microbial communities to warming. We discuss our results in reference to the long-term trajectory of the carbon and nutrient cycles of high-latitude permafrost regions.

  9. Nuclear Winter: Implications for civil defense

    Energy Technology Data Exchange (ETDEWEB)

    Chester, C.V.; Perry, A.M.; Hobbs, B.F.

    1988-05-01

    ''Nuclear Winter'' is the term given to the cooling hypothesized to occur in the Northern Hemisphere following a nuclear war as the result of the injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the paper was published in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. Three-dimensional global circulation models have resulted in reduced estimates of cooling---15 to 25/degree/C for a summer war and a few degrees for a winter war. More serious may be the possibility of suppression of convective precipitation by the altered temperature profiles in the atmosphere. However, very large uncertainties remain in input parameters, the models, and the results of calculations. We believe the state of knowledge about nuclear winter is sufficiently developed to conclude: Neither cold nor drought is likely to be a direct threat to human survival for populations with the wherewithal to survive normal January temperatures. The principal threat from nuclear winter is to food production, and this could present problems to third parties who are without food reserves. Loss of a crop year is neither a new nor an unexpected threat from nuclear war to the United States and the Soviet Union. Both have at least a year's food reserve at all times. Both face formidable organizational problems in distributing their reserves in a war-damaged environment. The consequences of nuclear winter could be expected to fall more heavily on the Soviet Union than the United States due to its higher latitude and less productive agriculture. This may be especially true if disturbances of rainfall amounts and distribution persist for more than a year.

  10. Deposition pattern and throughfall fluxes in secondary cool temperate forest, South Korea

    Science.gov (United States)

    Kumar Gautam, Mukesh; Lee, Kwang-Sik; Song, Byeong-Yeol

    2017-07-01

    Chemistry and deposition fluxes in the rainfall and throughfall of red pine (Pinus densiflora), black locust (Robinia pseudoacacia), and chestnut (Castanea crenata) monocultures, and mixed red pine-black locust-chestnut stands were examined in a nutrient-limited cool temperate forest of central South Korea. Throughfall was enriched in both basic and acidic constituents relative to rainfall, suggesting that both dry deposition and canopy leaching are important sources of throughfall constituents. Net throughfall fluxes (NTFs) of cations and anions significantly differed among four different stands as well as seasonally. Red pine exhibited highest fluxes (TF and NTF) for Ca2+, black locust for K+, mixed stands for Mg2+, and chestnut for Na+. In contrast, NTF of SO42-, NO3-, and NH4+was highest in the red pine, intermediate in the chestnut and mixed stands, and lowest in the black locust. In general, canopy uptake of H+ and NH4+ for all stands was higher in summer than in winter. Dry deposition appears to play a major role in atmospheric deposition to this cool temperate forest, especially in summer. Dry deposition for both cations and anions displayed high spatial variability, even though stands were adjacent to one another and experienced identical atmospheric deposition loads. Canopy leaching of K+ (95-78% of NTF), Mg2+ (92-23% of NTF), and Ca2+ (91-12% of NTF) was highest for the black locust, lowest for chestnut, and intermediate for the red pine and mixed stands. The present study documented significant changes in throughfall chemistry and NTF among different forest stands, which presumably be related with the differences in the canopy characteristics and differences in their scavenging capacity for dry deposition and canopy exchange. Difference in the canopy retention of H+ and base cation leaching suggests that canopy exchange was mainly driven by weak acid excretion and lesser by H+ exchange reaction. Our results indicate that despite a high base cation

  11. Environmental Controls and Management Effects on Ecosystem Carbon Exchange in Two Grazed Temperate Grasslands

    Science.gov (United States)

    Ni Choncubhair, O.; Humphreys, J.; Lanigan, G.

    2013-12-01

    Temperate grasslands constitute over 30% of the Earth's naturally-occurring biomes and make an important contribution towards the partial mitigation of anthropogenic greenhouse gas emissions by terrestrial ecosystems. Accumulation of carbon (C) in grassland systems predominantly takes place in below-ground repositories, enhanced by the presence of a stable soil environment with low carbon turnover rates, active rhizodeposition and high levels of residue and organic inputs. However, this C sequestration is strongly influenced by soil characteristics and climatic variables. Furthermore, in managed pasture systems, carbon exchange across the soil-atmosphere boundary is additionally affected by management activities, such as biomass removal, grazing events and the deposition or application of organic amendments. These biotic and abiotic factors contribute greatly towards the large uncertainty associated with the carbon balance of grassland ecosystems and demand further analysis. In the present study, the controls and drivers of carbon dynamics in two rotationally-grazed grasslands in Ireland were examined. The sites experience similar temperate climatic regimes but differ in soil texture classification and stocking rate. Eddy covariance measurements of net ecosystem exchange of carbon were complemented by regular assessment of standing biomass, leaf cover, harvest exports and organic amendment inputs. Our study showed that mild weather conditions and an extended growing season sustained net C accumulation at both sites for at least ten months of the year. Despite differing soil drainage characteristics, winter fluxes of net carbon exchange and its component fluxes, gross photosynthesis and ecosystem respiration, were highly comparable between the two sites. Management practices during the active growing season exerted a strong influence on both the direction and the rate of C exchange in the grassland systems, with a strong dependence, however, on the timing and

  12. Bifurcation dynamics of the tempered fractional Langevin equation.

    Science.gov (United States)

    Zeng, Caibin; Yang, Qigui; Chen, YangQuan

    2016-08-01

    Tempered fractional processes offer a useful extension for turbulence to include low frequencies. In this paper, we investigate the stochastic phenomenological bifurcation, or stochastic P-bifurcation, of the Langevin equation perturbed by tempered fractional Brownian motion. However, most standard tools from the well-studied framework of random dynamical systems cannot be applied to systems driven by non-Markovian noise, so it is desirable to construct possible approaches in a non-Markovian framework. We first derive the spectral density function of the considered system based on the generalized Parseval's formula and the Wiener-Khinchin theorem. Then we show that it enjoys interesting and diverse bifurcation phenomena exchanging between or among explosive-like, unimodal, and bimodal kurtosis. Therefore, our procedures in this paper are not merely comparable in scope to the existing theory of Markovian systems but also provide a possible approach to discern P-bifurcation dynamics in the non-Markovian settings.

  13. Bifurcation dynamics of the tempered fractional Langevin equation

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Caibin, E-mail: macbzeng@scut.edu.cn; Yang, Qigui, E-mail: qgyang@scut.edu.cn [School of Mathematics, South China University of Technology, Guangzhou 510640 (China); Chen, YangQuan, E-mail: ychen53@ucmerced.edu [MESA LAB, School of Engineering, University of California, Merced, 5200 N. Lake Road, Merced, California 95343 (United States)

    2016-08-15

    Tempered fractional processes offer a useful extension for turbulence to include low frequencies. In this paper, we investigate the stochastic phenomenological bifurcation, or stochastic P-bifurcation, of the Langevin equation perturbed by tempered fractional Brownian motion. However, most standard tools from the well-studied framework of random dynamical systems cannot be applied to systems driven by non-Markovian noise, so it is desirable to construct possible approaches in a non-Markovian framework. We first derive the spectral density function of the considered system based on the generalized Parseval's formula and the Wiener-Khinchin theorem. Then we show that it enjoys interesting and diverse bifurcation phenomena exchanging between or among explosive-like, unimodal, and bimodal kurtosis. Therefore, our procedures in this paper are not merely comparable in scope to the existing theory of Markovian systems but also provide a possible approach to discern P-bifurcation dynamics in the non-Markovian settings.

  14. Climate zones on Pluto and Charon

    Science.gov (United States)

    Binzel, Richard P.; Earle, Alissa M.; Buie, Marc W.; Young, Leslie A.; Stern, S. Alan; Olkin, Cathy B.; Ennico, Kimberly; Moore, Jeffrey M.; Grundy, Will; Weaver, Harold A.; Lisse, Carey M.; Lauer, Tod R.; New Horizons Geology; Geophysics Imaging Team

    2017-05-01

    We give an explanatory description of the unusual ;climate zones; on Pluto that arise from its high obliquity (mean 115°) and high amplitude (±12°) of obliquity oscillation over a 2.8 million year period. The zones we describe have astronomically defined boundaries and do not incorporate atmospheric circulation. For such a high mean obliquity, the lines of tropics (greatest latitudes where the Sun can be overhead) cycle closer to each pole than does each arctic circle, which in turn cycle nearly to the equator. As a consequence in an astronomical context, Pluto is more predominantly ;tropical; than ;arctic.; Up to 97% of Pluto's surface area can experience overhead Sun when the obliquity cycle is at its minimum of 103°. At this same obliquity phase (most recently occurring 0.8 Myr ago), 78% of Pluto's surface experienced prolonged intervals without sunlight or ;arctic winter; (and corresponding ;arctic summer;). The intersection of these climate zones implies that a very broad range of Pluto's latitudes (spanning 13-77° in each hemisphere; 75% of the total surface area) are both tropical and arctic. While some possible correlations to these climate zones are suggested by comparison with published maps of Pluto and Charon yielded by the New Horizons mission, in this work we present a non-physical descriptive analysis only. For example, the planet-wide dark equatorial band presented by Stern et al. (2015; Science, 350, 292-299) corresponds to Pluto's permanent ;diurnal zone.; In this zone spanning latitudes within ±13° of the equator, day-night cycles occur each Pluto rotation (6.4 days) such that neither ;arctic winter; nor ;arctic summer; has been experienced in this zone for at least 20 million years. The stability of this and other climate zones may extend over several Gyr. Temperature modeling shows that the continuity of diurnal cycles in this region may be the key factor enabling a long-term stability for the high albedo contrast between Tombaugh Regio

  15. Tropical fishes dominate temperate reef fish communities within western Japan.

    Science.gov (United States)

    Nakamura, Yohei; Feary, David A; Kanda, Masaru; Yamaoka, Kosaku

    2013-01-01

    Climate change is resulting in rapid poleward shifts in the geographical distribution of tropical and subtropical fish species. We can expect that such range shifts are likely to be limited by species-specific resource requirements, with temperate rocky reefs potentially lacking a range of settlement substrates or specific dietary components important in structuring the settlement and success of tropical and subtropical fish species. We examined the importance of resource use in structuring the distribution patterns of range shifting tropical and subtropical fishes, comparing this with resident temperate fish species within western Japan (Tosa Bay); the abundance, diversity, size class, functional structure and latitudinal range of reef fishes utilizing both coral reef and adjacent rocky reef habitat were quantified over a 2 year period (2008-2010). This region has undergone rapid poleward expansion of reef-building corals in response to increasing coastal water temperatures, and forms one of the global hotspots for rapid coastal changes. Despite the temperate latitude surveyed (33°N, 133°E) the fish assemblage was both numerically, and in terms of richness, dominated by tropical fishes. Such tropical faunal dominance was apparent within both coral, and rocky reef habitats. The size structure of the assemblage suggested that a relatively large number of tropical species are overwintering within both coral and rocky habitats, with a subset of these species being potentially reproductively active. The relatively high abundance and richness of tropical species with obligate associations with live coral resources (i.e., obligate corallivores) shows that this region holds the most well developed temperate-located tropical fish fauna globally. We argue that future tropicalisation of the fish fauna in western Japan, associated with increasing coral habitat development and reported increasing shifts in coastal water temperatures, may have considerable positive economic

  16. First description of underwater acoustic diversity in three temperate ponds

    Directory of Open Access Journals (Sweden)

    Camille Desjonquères

    2015-11-01

    Full Text Available The past decade has produced an increased ecological interest in sonic environments, or soundscapes. However, despite this rise in interest and technological improvements that allow for long-term acoustic surveys in various environments, some habitats’ soundscapes remain to be explored. Ponds, and more generally freshwater habitats, are one of these acoustically unexplored environments. Here we undertook the first long term acoustic monitoring of three temperate ponds in France. By aural and visual inspection of a selection of recordings, we identified 48 different sound types, and according to the rarefaction curves we calculated, more sound types are likely present in one of the three ponds. The richness of sound types varied significantly across ponds. Surprisingly, there was no pond-to-pond daily consistency of sound type richness variation; each pond had its own daily patterns of activity. We also explored the possibility of using six acoustic diversity indices to conduct rapid biodiversity assessments in temperate ponds. We found that all indices were sensitive to the background noise as estimated through correlations with the signal-to-noise ratio (SNR. However, we determined that the AR index could be a good candidate to measure acoustic diversities using partial correlations with the SNR as a control variable. Yet, research is still required to automatically compute the SNR in order to apply this index on a large data set of recordings. The results showed that these three temperate ponds host a high level of acoustic diversity in which the soundscapes were variable not only between but also within the ponds. The sources producing this diversity of sounds and the drivers of difference in daily song type richness variation both require further investigation. Such research would yield insights into the biodiversity and ecology of temperate ponds.

  17. Increase in forest growth: new evidences from temperate forests

    Directory of Open Access Journals (Sweden)

    Lingua E

    2010-07-01

    Full Text Available A paper recently published on PNAS provides a new evidence for an increase in forest growth in temperate forests. The possible causes of this process are discussed. The results show a relation between this change in tree growth with the increase in atmospheric CO2 concentration, temperature, and length of growth season. A better understanding of the specific mechanisms involved and the assessment of the consequences on the current and future global changes are needed.

  18. Tropical Fishes Dominate Temperate Reef Fish Communities within Western Japan

    OpenAIRE

    Yohei Nakamura; Feary, David A.; Masaru Kanda; Kosaku Yamaoka

    2013-01-01

    Climate change is resulting in rapid poleward shifts in the geographical distribution of tropical and subtropical fish species. We can expect that such range shifts are likely to be limited by species-specific resource requirements, with temperate rocky reefs potentially lacking a range of settlement substrates or specific dietary components important in structuring the settlement and success of tropical and subtropical fish species. We examined the importance of resource use in structuring t...

  19. Groundwater flow modelling of periods with temperate climate conditions - Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Roberts, David; Swan, David (Serco Technical Consulting Services (United Kingdom)); Gylling, Bjoern; Marsic, Niko (Kemakta Konsult AB, Stockholm (Sweden)); Rhen, Ingvar (SWECO Environment AB, Falun (Sweden))

    2010-12-15

    As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Laxemar-Simpevarp site during temperate climate conditions as a comparison to corresponding modelling carried out for Forsmark /Joyce et al. 2010/. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a Hydrogeological base case (reference case conceptualisation) and then an examination of various areas of uncertainty within the current understanding by a series of model variants. The Hydrogeological base case models at three different scales, 'repository', 'site' and 'regional' make use of a discrete fracture network (DFN) and equivalent continuous porous medium (ECPM) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 15,000 AD. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

  20. The Research and Application of Webpage Temper-proofing System

    OpenAIRE

    Wang Yongquan; Wu Beihua

    2012-01-01

    With the sharp increase of hacking attacks over the last couple of years, web application security has become a key concern. The attack to websites, especially the explosion of webpage interpolating incidents has becomeone of the most serious problems of it. In this paper, the system adopts Web server core embedded technology to imbed tamper detection module and application protection module into the Web server, define correspondingstrategies for temper-proofing, and realize the real-time m...

  1. Computer simulation of quenched and tempered steel properties

    OpenAIRE

    B. Smoljan; D. Iljkić; Novak, H.

    2011-01-01

    Purpose: The algorithm of estimation of mechanical properties based on steel hardness has been established.Design/methodology/approach: Numerical modelling of hardness distribution in as-quenched steel specimen was performed by involving the results of simple experimental test, i.e., Jominy-test. Hardness of quenched and tempered steel has been expressed as function of maximal hardness of actual steel and hardness of actual steel with 50% of martensite in microstructure, according to the time...

  2. First description of underwater acoustic diversity in three temperate ponds

    Science.gov (United States)

    Rybak, Fanny; Depraetere, Marion; Gasc, Amandine; Le Viol, Isabelle; Pavoine, Sandrine; Sueur, Jérôme

    2015-01-01

    The past decade has produced an increased ecological interest in sonic environments, or soundscapes. However, despite this rise in interest and technological improvements that allow for long-term acoustic surveys in various environments, some habitats’ soundscapes remain to be explored. Ponds, and more generally freshwater habitats, are one of these acoustically unexplored environments. Here we undertook the first long term acoustic monitoring of three temperate ponds in France. By aural and visual inspection of a selection of recordings, we identified 48 different sound types, and according to the rarefaction curves we calculated, more sound types are likely present in one of the three ponds. The richness of sound types varied significantly across ponds. Surprisingly, there was no pond-to-pond daily consistency of sound type richness variation; each pond had its own daily patterns of activity. We also explored the possibility of using six acoustic diversity indices to conduct rapid biodiversity assessments in temperate ponds. We found that all indices were sensitive to the background noise as estimated through correlations with the signal-to-noise ratio (SNR). However, we determined that the AR index could be a good candidate to measure acoustic diversities using partial correlations with the SNR as a control variable. Yet, research is still required to automatically compute the SNR in order to apply this index on a large data set of recordings. The results showed that these three temperate ponds host a high level of acoustic diversity in which the soundscapes were variable not only between but also within the ponds. The sources producing this diversity of sounds and the drivers of difference in daily song type richness variation both require further investigation. Such research would yield insights into the biodiversity and ecology of temperate ponds. PMID:26587351

  3. Small Sample Sizes Yield Biased Allometric Equations in Temperate Forests

    OpenAIRE

    Duncanson, L.; Rourke, O.; Dubayah, R.

    2015-01-01

    Accurate quantification of forest carbon stocks is required for constraining the global carbon cycle and its impacts on climate. The accuracies of forest biomass maps are inherently dependent on the accuracy of the field biomass estimates used to calibrate models, which are generated with allometric equations. Here, we provide a quantitative assessment of the sensitivity of allometric parameters to sample size in temperate forests, focusing on the allometric relationship between tree height a...

  4. Indirect effects of sea otter recovery on temperate reef fish

    OpenAIRE

    Silberg, Joshua Neal

    2015-01-01

    The loss or recovery of apex predators can have profound positive or negative ecological and socio-economic impacts. Effects of predator depletion or recovery are frequently accompanied by time lags, which are often context-dependent. In temperate rocky reef ecosystems, sea otters (Enhydra lutris) trigger a cascade of direct and indirect effects driving transitions between kelp-depleted and kelp-dominated states. We quantified the indirect effects of sea otter recovery on copper rockfish (Seb...

  5. Tropical fishes dominate temperate reef fish communities within western Japan.

    Directory of Open Access Journals (Sweden)

    Yohei Nakamura

    Full Text Available Climate change is resulting in rapid poleward shifts in the geographical distribution of tropical and subtropical fish species. We can expect that such range shifts are likely to be limited by species-specific resource requirements, with temperate rocky reefs potentially lacking a range of settlement substrates or specific dietary components important in structuring the settlement and success of tropical and subtropical fish species. We examined the importance of resource use in structuring the distribution patterns of range shifting tropical and subtropical fishes, comparing this with resident temperate fish species within western Japan (Tosa Bay; the abundance, diversity, size class, functional structure and latitudinal range of reef fishes utilizing both coral reef and adjacent rocky reef habitat were quantified over a 2 year period (2008-2010. This region has undergone rapid poleward expansion of reef-building corals in response to increasing coastal water temperatures, and forms one of the global hotspots for rapid coastal changes. Despite the temperate latitude surveyed (33°N, 133°E the fish assemblage was both numerically, and in terms of richness, dominated by tropical fishes. Such tropical faunal dominance was apparent within both coral, and rocky reef habitats. The size structure of the assemblage suggested that a relatively large number of tropical species are overwintering within both coral and rocky habitats, with a subset of these species being potentially reproductively active. The relatively high abundance and richness of tropical species with obligate associations with live coral resources (i.e., obligate corallivores shows that this region holds the most well developed temperate-located tropical fish fauna globally. We argue that future tropicalisation of the fish fauna in western Japan, associated with increasing coral habitat development and reported increasing shifts in coastal water temperatures, may have considerable

  6. Convergence, Consilience, and the Evolution of Temperate Deciduous Forests.

    Science.gov (United States)

    Edwards, Erika J; Chatelet, David S; Chen, Bo-Chang; Ong, Jin Yao; Tagane, Shuichiro; Kanemitsu, Hironobu; Tagawa, Kazuki; Teramoto, Kentaro; Park, Brian; Chung, Kuo-Fang; Hu, Jer-Ming; Yahara, Tetsukazu; Donoghue, Michael J

    2017-08-01

    The deciduous habit of northern temperate trees and shrubs provides one of the most obvious examples of convergent evolution, but how did it evolve? Hypotheses based on the fossil record posit that deciduousness evolved first in response to drought or darkness and preadapted certain lineages as cold climates spread. An alternative is that evergreens first established in freezing environments and later evolved the deciduous habit. We monitored phenological patterns of 20 species of Viburnum spanning tropical, lucidophyllous (subtropical montane and warm temperate), and cool temperate Asian forests. In lucidophyllous forests, all viburnums were evergreen plants that exhibited coordinated leaf flushes with the onset of the rainy season but varied greatly in the timing of leaf senescence. In contrast, deciduous species exhibited tight coordination of both flushing and senescence, and we found a perfect correlation between the deciduous habit and prolonged annual freezing. In contrast to previous stepwise hypotheses, a consilience of independent lines of evidence supports a lockstep model in which deciduousness evolved in situ, in parallel, and concurrent with a gradual cooling climate. A pervasive selective force combined with the elevated evolutionary accessibility of a particular response may explain the massive convergence of adaptive strategies that characterizes the world's biomes.

  7. Grain boundary diffusion in terms of the tempered fractional calculus

    Energy Technology Data Exchange (ETDEWEB)

    Sibatov, R.T., E-mail: ren_sib@bk.ru [Ulyanovsk State University, 432017, 42 Leo Tolstoy str., Ulyanovsk (Russian Federation); Svetukhin, V.V. [Ulyanovsk State University, 432017, 42 Leo Tolstoy str., Ulyanovsk (Russian Federation); Institute of Nanotechnology and Microelectronics of the Russian Academy of Sciences, 115487, 18 Nagatinskaya str., Moscow (Russian Federation)

    2017-06-28

    Mathematical treatment of grain-boundary diffusion based on the model first proposed by Fisher is usually formulated in terms of normal diffusion equations in a two-component nonhomogeneous medium. On the other hand, fractional equations of anomalous diffusion proved themselves to be useful in description of grain-boundary diffusion phenomena. Moreover, the most important propagation regime predicted by Fisher's model demonstrates subdiffusive behavior. However, the direct link between fractional approach and the Fisher model and its modifications has not found yet. Here, we fill this gap and show that solution of fractional subdiffusion equation offers general properties of classical solutions obtained by Whipple and Suzuoka. The tempered fractional approach is a convenient tool for studying precipitation in granular materials as the tempered subdiffusion limited process. - Highlights: • The link connected fractional diffusion approach and Fisher's model of grain-boundary diffusion is derived. • The subdiffusion exponent of grain-boundary diffusion can differ from 1/2. • Nucleation in granular materials is modeled by the process limited by tempered subdiffusion.

  8. Sliding mode controllers for a tempered glass furnace.

    Science.gov (United States)

    Almutairi, Naif B; Zribi, Mohamed

    2016-01-01

    This paper investigates the design of two sliding mode controllers (SMCs) applied to a tempered glass furnace system. The main objective of the proposed controllers is to regulate the glass plate temperature, the upper-wall temperature and the lower-wall temperature in the furnace to a common desired temperature. The first controller is a conventional sliding mode controller. The key step in the design of this controller is the introduction of a nonlinear transformation that maps the dynamic model of the tempered glass furnace into the generalized controller canonical form; this step facilitates the design of the sliding mode controller. The second controller is based on a state-dependent coefficient (SDC) factorization of the tempered glass furnace dynamic model. Using an SDC factorization, a simplified sliding mode controller is designed. The simulation results indicate that the two proposed control schemes work very well. Moreover, the robustness of the control schemes to changes in the system's parameters as well as to disturbances is investigated. In addition, a comparison of the proposed control schemes with a fuzzy PID controller is performed; the results show that the proposed SDC-based sliding mode controller gave better results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  9. Comparative visual ecophysiology of mid-Atlantic temperate reef fishes

    Directory of Open Access Journals (Sweden)

    Andrij Z. Horodysky

    2013-11-01

    The absolute light sensitivities, temporal properties, and spectral sensitivities of the visual systems of three mid-Atlantic temperate reef fishes (Atlantic spadefish [Ephippidae: Chaetodipterus faber], tautog [Labridae: Tautoga onitis], and black sea bass [Serranidae: Centropristis striata] were studied via electroretinography (ERG. Pelagic Atlantic spadefish exhibited higher temporal resolution but a narrower dynamic range than the two more demersal foragers. The higher luminous sensitivities of tautog and black sea bass were similar to other benthic and demersal coastal mid-Atlantic fishes. Flicker fusion frequency experiments revealed significant interspecific differences at maximum intensities that correlated with lifestyle and habitat. Spectral responses of the three species spanned 400–610 nm, with high likelihood of cone dichromacy providing the basis for color and contrast discrimination. Significant day-night differences in spectral responses were evident in spadefish and black sea bass but not tautog, a labrid with characteristic structure-associated nocturnal torpor. Atlantic spadefish responded to a wider range of wavelengths than did deeper-dwelling tautog or black sea bass. Collectively, these results suggest that temperate reef-associated fishes are well-adapted to their gradient of brighter to dimmer photoclimates, representative of their unique ecologies and life histories. Continuing anthropogenic degradation of water quality in coastal environments, at a pace faster than the evolution of visual systems, may however impede visual foraging and reproductive signaling in temperate reef fishes.

  10. West Nile Virus Activity in a Winter Roost of American Crows (Corvus brachyrhynchos): Is Bird-To-Bird Transmission Important in Persistence and Amplification?

    Science.gov (United States)

    Hinton, M G; Reisen, W K; Wheeler, S S; Townsend, A K

    2015-07-01

    Since its emergence in North America, West Nile virus (WNV) has had a large impact on equines, humans, and wild bird communities, yet gaps remain in our understanding of how the virus persists at temperate latitudes when winter temperatures preclude virus replication and host-seeking activity by mosquito vectors. Bird-to-bird transmission at large communal American Crow roosts could provide one mechanism for WNV persistence. Herein, we describe seasonal patterns of crow and Culex mosquito abundance, WNV infection rates, and the prevalence of WNV-positive fecal samples at a winter crow roost to test the hypothesis that bird-to-bird transmission allows WNV to persist at winter crow roosts. Samples were collected from large winter crow roosts in the Sacramento Valley of California from January 2013 until August 2014, encompassing two overwintering roost periods. West Nile virus RNA was detected in local crow carcasses in both summer [13/18 (72% WNV positive)] and winter [18/44 (41% WNV positive)] 2013-2014. Winter infections were unlikely to have arisen by recent bites from infected mosquitoes because Culex host-seeking activity was very low in winter and all Culex mosquitoes collected during winter months tested negative for WNV. Opportunities existed for fecal-oral transfer at the overwintering roost: most carcasses that tested positive for WNV had detectable viral RNA in both kidney and cloacal swabs, suggesting that infected crows were shedding virus in their feces, and >50% of crows at the roost were stained with feces by mid-winter. Moreover, 2.3% of fecal samples collected in late summer, when mosquitoes were active, tested positive for WNV RNA. Nevertheless, none of the 1,119 feces collected from three roosts over two winters contained detectable WNV RNA. This study provided evidence of WNV infection in overwintering American crows without mosquito vector activity, but did not elucidate a mechanism of WNV transmission during winter. © The Authors 2015

  11. The possibility of tribopair lifetime extending by welding of quenched and tempered stainless steel with quenched and tempered carbon steel

    Directory of Open Access Journals (Sweden)

    V. Marušić

    2015-04-01

    Full Text Available In the conditions of tribocorrosion wear, extending of parts lifetime could be achieved by using stainless steel,which is hardened to sufficiently high hardness. In the tribosystem bolt/ bushing shell/link plate of the bucket elevator transporter conveyor machine, the previously quenched and tempered martensitic stainless steel for bolts is hardened at ≈47 HRC and welded with the quenched and tempered high yield carbon steel for bolts. Additional material, based on Cr-Ni-Mo (18/8/6 is used. The microstructure and hardness of welded samples are tested. On the tensile tester, resistance of the welded joint is tested with a simulated experiment. Dimensional control of worn tribosystem elements was performed after six months of service.

  12. Round herring (genus Etrumeus) contain distinct evolutionary lineages coincident with a biogeographic barrier along Australia’s southern temperate coastline

    KAUST Repository

    DiBattista, Joseph

    2014-08-28

    Molecular genetic surveys of marine fishes have revealed that some widely distributed species are actually a composite of multiple evolutionary lineages. This is apparent in the round herrings (genus Etrumeus), wherein a globally distributed taxon (Etrumeus sadina Mitchill 1814) has proven to contain at least seven valid taxa, with more likely awaiting discovery. Here, we survey evolutionary lineages of the nominal E. sadina (formerly E. teres, a junior synonym) across the southern temperate zone of Australia, a marine region divided into three biogeographic provinces based primarily on the distribution of intertidal faunas. Results from morphological and mitochondrial DNA data reveal two evolutionary lineages corresponding to eastern and southwestern provinces (d = 0.007 for cytochrome c oxidase subunit I and d = 0.017 for cytochrome b), possibly initiated by the Bassian Isthmus between Australia and Tasmania during low sea-level stands. The Australian round herring is also genetically distinct from the nearest congeneric forms in the Indian and Pacific Oceans, with a corresponding modal difference in gill-raker counts in most cases. Based on these data, we resurrect the title Etrumeus jacksoniensis for the Australian round herring. While the Bassian Isthmus may have initiated the partition of evolutionary lineages within Australia, additional oceanographic and ecological factors must reinforce this separation in order to maintain diagnostic genetic differences along a continuous temperate coastline. © 2014 Springer-Verlag Berlin Heidelberg.

  13. Studying the Effect of PWHT on Microstructural Evolution and Mechanical Properties of Welded A517 Quenched and Tempered Steel

    Science.gov (United States)

    Rabiei, Arash; Derakhshandeh-Haghighi, Reza

    2017-09-01

    Sometimes post-weld heat treatment (PWHT) is required for stress relieving both the weld metal and heat-affected zone in A517 Quenched and Tempered (QT) steels. This process unavoidably results in further tempering which adversely affects the mechanical properties of the welded joints. Investigations on A517 QT steel are presented in as-welded condition and after PWHT at 560 and 630 °C. Microstructural variation upon applying PWHT and its influence on impact absorbed energy, fatigue behavior, tensile and hardness properties of the material in as-welded condition and after PWHT are studied. The decrease in hardness is very remarkable after PWHT at 630 °C. Increasing heat treatment temperature from 560 to 630 °C results in reduction of YS and UTS. Void coalescence and coarsening of carbides after PWHT makes the fracture easier and results in reduction of absorbed impact energy. Elimination of acicular ferrite after PWHT at 630 °C increases crack growth rate, and fatigue endurance limit is reduced.

  14. School of Culinary Arts & Food Technology Winter Newsletter 2016

    OpenAIRE

    Murphy, James Peter

    2016-01-01

    The School of Culinary Arts & Food Technology - Winter Newsletter captured the many events, research, awards, significant contributions and special activities which the students and staff members of the school have successfully completed leading up to the Winter period of 2016.

  15. Safety and mobility impacts of winter weather - phase 3.

    Science.gov (United States)

    2014-09-01

    Highway agencies spend millions of dollars to ensure safe and efficient winter travel. However, the effectiveness of winter-weather : maintenance practices on safety and mobility are somewhat difficult to quantify. Safety and Mobility Impacts of Wint...

  16. Safety and mobility impacts of winter weather : phase I.

    Science.gov (United States)

    2011-08-01

    Highway agencies spend millions of dollars to ensure safe and efficient winter travel. However, the effectiveness of winter weather maintenance practices on safety and mobility are somewhat difficult to quantify. : Phase I of this project investigate...

  17. Seasonal affective disorder, winter type: current insights and treatment options

    National Research Council Canada - National Science Library

    Meesters Y; Gordijn MCM

    2016-01-01

    ...., Groningen, the Netherlands Abstract: Seasonal affective disorder (SAD), winter type, is a seasonal pattern of recurrent major depressive episodes most commonly occurring in autumn or winter and remitting in spring/summer...

  18. Seed wintering and deterioration characteristics between weedy and cultivated rice

    OpenAIRE

    Baek, Jung-Sun; Chung, Nam-Jin

    2012-01-01

    Background Incidences of weedy rice continuously occurred in paddy fields because its shattering seeds were able to over-winter. In this research, the seed deterioration of weedy rice was investigated compared with cultivated rice, and the wintering characteristics of these two types of rice were investigated with the field wintering test, freezing resistance test, and accelerated aging test. Results For the wintering test, the seeds of weedy rice were placed on the soil surface of a paddy wi...

  19. Wetter and cooler: pronounced temperate climate conditions in western Anatolia during the Middle Miocene Climatic Optimum

    Science.gov (United States)

    Güner, Tuncay H.; Bouchal, Johannes M.; Köse, Nesibe; Denk, Thomas

    2017-04-01

    During the course of an ongoing palaeobotanical investigation of the lignite mines of the Yataǧan Basin, Muǧla province, Turkey, the fossil leaves of the Eskihisar lignite mine were analysed using the Climate Leaf Analysis Multivariate Program (CLAMP). The investigated fossil leaves derive from the marls and clayey limestones (Sekköy Member) overlying the exploited lignite seam (uppermost Turgut Member). The age of the studied sedimentary rocks is well constrained by vertebrate fossils occuring in the main lignite seam (MN6 → Gomphoterium angustidens Cuvier, 1817; Percrocuta miocenica Pavlov & Thenius, 1965) and at the Yenieskihisar Mammal locality (MN7/8, uppermost Sekköy Member). 719 specimens were measured and assigned to 65 leaf morphotypes. Using this data, CLAMP reconstructed the following climate parameters: mean annual temperature (MAT) 12.58 (+/-1.5)°C, warm month mean temperature (WMMT) 23.72 (+/-2.5)°C, cold month mean temperature (WMMT) 2.29 (+/-2)°C, length of growing season (LGS) 7.52 (+/-0.75) month, mean growing season precipitation (GSP) 130.1 (+/-40) cm, precipitation during the three wettest months (3-WET) 67 (+/-25) cm, precipitation during the three driest months (3-DRY) 20.4 (+/-7.5) cm. The reconstructed parameters are too cool for tropical climates (the 18˚ C winter isotherm being a threshold for tropical climates) and indicate temperate conditions; climates fitting these parameters (Cfb according to the Köppen-Geiger climate classification) can be found today in regions known as "Tertiary relict areas" (e.g. Black sea coast of Northeast Turkey, eastern China, Japan). Based on a substantial amount of rainfall during the three driest months, it is further possible to exclude markedly seasonal climates such as a summer-dry and winter-wet Mediterranean climate and a summer-wet and winter-dry monsoon climate as commonly found along the southern foothills of the Himalayas and in southwestern China. Instead, a fully humid Cf climate is

  20. Postharvest tillage reduces Downy Brome infestations in winter wheat

    Science.gov (United States)

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

  1. Probabilistic Weather Forecasting for Winter Road Maintenance

    Science.gov (United States)

    2007-04-03

    2002–2003. . . 5 3 Bayesian estimates of α0, α1, α2, α3, α4 and σ 2 versus time. . . . . . . . . . . . . . . 9 4 Empirical variogram of the residuals...equations, and forecast future weather by integrating them forward in time. Both kinds of forecast are deterministic and do not assess uncertainty ...the 2002–2003 winter season. We constructed the empirical variogram of the residuals of the linear regression of the observed temperature on the

  2. Measuring Transpiration to Regulate Winter Irrigation Rates

    Energy Technology Data Exchange (ETDEWEB)

    Samuelson, Lisa [Auburn University

    2006-11-08

    Periodic transpiration (monthly sums) in a young loblolly pine plantation between ages 3 and 6 was measured using thermal dissipation probes. Fertilization and fertilization with irrigation were better than irrigation alone in increasing transpiration of young loblolly pines during winter months, apparently because of increased leaf area in fertilized trees. Irrigation alone did not significantly increase transpiration compared with the non-fertilized and non-irrigated control plots.

  3. 31st Winter Workshop in Nuclear Dynamics

    CERN Document Server

    2015-01-01

    The 31st edition of the Winter Workshop will be held January 25-31st, 2015 in the Keystone Resort, Colorado, USA. As with previous years, the workshop will bring together scientists from all fields of nuclear physics for engaging and friendly exchanges of ideas. Much emphasis will be on the recent LHC and RHIC heavy ion results, but advances in the ongoing and future programs at FAIR, FRIB, NICA and JLab will also be featured.

  4. Holt-Winters Method with Missing Observations

    OpenAIRE

    Tomá\\v{s} Cipra; José Trujillo; Asunción Robio

    1995-01-01

    The paper presents a simple procedure for interpolating, smoothing, and predicting in seasonal time series with missing observations. The approach suggested by Wright (Wright, D. J. 1986. Forecasting data published at irregular time intervals using extension of Holt's method. Management Sci. 32 499--510.) for the Holt's method with nonseasonal data published at irregular time intervals is extended to the Holt-Winters method in the seasonal case. Numerical examples demonstrate the procedure.

  5. Bionomics of temperate and tropical Culicoides midges: knowledge gaps and consequences for transmission of Culicoides-borne viruses.

    Science.gov (United States)

    Purse, B V; Carpenter, S; Venter, G J; Bellis, G; Mullens, B A

    2015-01-07

    Culicoides midges are abundant hematophagous flies that vector arboviruses of veterinary and medical importance. Dramatic changes in the epidemiology of Culicoides-borne arboviruses have occurred since 1998, including the emergence of exotic viruses in northern temperate regions, increases in global disease incidence, and enhanced virus diversity in tropical zones. Drivers may include changes in climate, land use, trade, and animal husbandry. New Culicoides species and new wild reservoir hosts have been implicated in transmission, highlighting the dynamic nature of pathogen-vector-host interactions. Focusing on potential vector species worldwide and key elements of vectorial capacity, we review the sensitivity of Culicoides life cycles to abiotic and biotic factors. We consider implications for designing control measures and understanding impacts of environmental change in different ecological contexts. Critical geographical, biological, and taxonomic knowledge gaps are prioritized. Recent developments in genomics and mathematical modeling may enhance ecological understanding of these complex arbovirus systems.

  6. Altitudinal variation in soil organic carbon stock in coniferous subtropical and broadleaf temperate forests in Garhwal Himalaya

    Directory of Open Access Journals (Sweden)

    Kumar Munesh

    2009-08-01

    Full Text Available Abstract Background The Himalayan zones, with dense forest vegetation, cover a fifth part of India and store a third part of the country reserves of soil organic carbon (SOC. However, the details of altitudinal distribution of these carbon stocks, which are vulnerable to forest management and climate change impacts, are not well known. Results This article reports the results of measuring the stocks of SOC along altitudinal gradients. The study was carried out in the coniferous subtropical and broadleaf temperate forests of Garhwal Himalaya. The stocks of SOC were found to be decreasing with altitude: from 185.6 to 160.8 t C ha-1 and from 141.6 to 124.8 t C ha-1 in temperature (Quercus leucotrichophora and subtropical (Pinus roxburghii forests, respectively. Conclusion The results of this study lead to conclusion that the ability of soil to stabilize soil organic matter depends negatively on altitude and call for comprehensive theoretical explanation

  7. Net ecosystem exchange of CO2 and carbon balance for eight temperate organic soils under agricultural management

    DEFF Research Database (Denmark)

    Elsgaard, Lars; Görres, C.-M.; Hoffmann, Carl Christian

    2012-01-01

    This study presents the first annual estimates of net ecosystem exchange (NEE) of CO2 and net ecosystem carbon balances (NECB) of contrasting Danish agricultural peatlands. Studies were done at eight sites representing permanent grasslands (PG) and rotational (RT) arable soils cropped to barley......) sites, NEE (mean ± standard error, SE) was 5.1 ± 0.9 and 8.6 ± 2.0 Mg C ha−1 yr−1, respectively, but with the overall lowest value observed for potato cropping (3.5 Mg C ha−1 yr−1). This was partly attributed to a short-duration vegetation period and drying of the soil especially in potato ridges. NECB...... and temperate climate zones. It was stressed that evaluation of emission factors should explicitly differentiate between data representing net C balance from a soil perspective and CO2-C balance from an atmospheric perspective. Modelling of inter-annual variability in NEE for three selected sites during a 21...

  8. Comparison of N2O Emissions from Soils at Three Temperate Agricultural Sites

    Science.gov (United States)

    Frolking, S. E.; Moiser, A. R.; Ojima, D. S.; Li, C.; Parton, W. J.; Potter, C. S.; Priesack, E.; Stenger, R.; Haberbosch, C.; Dorsch, P.; hide

    1997-01-01

    Nitrous oxide (N2O) flux simulations by four models were compared with year-round field measurements from five temperate agricultural sites in three countries. The field sites included an unfertilized, semi-arid rangeland with low N2O fluxes in eastern Colorado, USA; two fertilizer treatments (urea and nitrate) on a fertilized grass ley cut for silage in Scotland; and two fertilized, cultivated crop fields in Germany where N2O loss during the winter was quite high. The models used were daily trace gas versions of the CENTURY model, DNDC, ExpertN, and the NASA-Ames version of the CASA model. These models included similar components (soil physics, decomposition, plant growth, and nitrogen transformations), but in some cases used very different algorithms for these processes. All models generated similar results for the general cycling of nitrogen through the agro-ecosystems, but simulated nitrogen trace gas fluxes were quite different. In most cases the simulated N20 fluxes were within a factor of about 2 of the observed annual fluxes, but even when models produced similar N2O fluxes they often produced very different estimates of gaseous N loss as nitric oxide (NO), dinitrogen (N2), and ammonia (NH3). Accurate simulation of soil moisture appears to be a key requirement for reliable simulation of N2O emissions. All models simulated the general pattern of low background fluxes with high fluxes following fertilization at the Scottish sites, but they could not (or were not designed to) accurately capture the observed effects of different fertilizer types on N2O flux. None of the models were able to reliably generate large pulses of N2O during brief winter thaws that were observed at the two German sites. All models except DNDC simulated very low N2O fluxes for the dry site in Colorado. The US Trace Gas Network (TRAGNET) has provided a mechanism for this model and site intercomparison. Additional intercomparisons are needed with these and other models and additional data

  9. Investigating Aquatic Dead Zones

    Science.gov (United States)

    Testa, Jeremy; Gurbisz, Cassie; Murray, Laura; Gray, William; Bosch, Jennifer; Burrell, Chris; Kemp, Michael

    2010-01-01

    This article features two engaging high school activities that include current scientific information, data, and authentic case studies. The activities address the physical, biological, and chemical processes that are associated with oxygen-depleted areas, or "dead zones," in aquatic systems. Students can explore these dead zones through both…

  10. Work zone safety analysis.

    Science.gov (United States)

    2013-11-01

    This report presents research performed analyzing crashes in work zones in the state of New Jersey so as to : identify critical areas in work zones susceptible to crashes and key factors that contribute to these crashes. A field : data collection on ...

  11. $\\mu$-tempered metadynamics: Artifact independent convergence times for wide hills

    CERN Document Server

    Dickson, Bradley M

    2015-01-01

    Recent analysis of well-tempered metadynamics (WTmetaD) showed that it converges without mollification artifacts in the bias potential. Here we explore how metadynamics heals mollification artifacts, how healing impacts convergence time, and whether alternative temperings may be used to improve efficiency. We introduce "$\\mu$-tempered" metadynamics as a simple tempering scheme, inspired by a related mollified adaptive biasing potential (mABP), that results in artifact independent convergence of the free energy estimate. We use a toy model to examine the role of artifacts in WTmetaD and solvated alanine dipeptide to compare the well-tempered and $\\mu$-tempered frameworks demonstrating fast convergence for hill widths as large as $60^{\\circ}$ for $\\mu$TmetaD.

  12. Dilatometric and hardness analysis of C45 steel tempering with different heating-up rates

    Directory of Open Access Journals (Sweden)

    A. Kulawik

    2012-01-01

    Full Text Available Modelling of technological processes of heat treatment or welding, involving multiple heat source transitions, requires considering the phenomenon of tempering. In work have been presented results of dilatometric research of hardened C45 steel subjected to tempering. The analysis of the influence of heating rate at the kinetic determined from dilatometric curves has been made. There have also been estimated quantities of transformation expansions and thermal expansion coefficients of hardening and tempering structures (austenite, ferrite, pearlite, martensite and sorbite. The analysis of tempering time influence on the hardness of tempered steel has been made. Functions associating hardness with tempering time (rate of heating-up in technological processes based on short-timed action of a heat source (eg. laser treatment have been suggested.

  13. Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse.

    Directory of Open Access Journals (Sweden)

    Kamil Erguler

    Full Text Available The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations.

  14. Sediment carbon and nutrient fluxes from cleared and intact temperate mangrove ecosystems and adjacent sandflats.

    Science.gov (United States)

    Bulmer, Richard H; Schwendenmann, Luitgard; Lohrer, Andrew M; Lundquist, Carolyn J

    2017-12-01

    The loss of mangrove ecosystems is associated with numerous impacts on coastal and estuarine function, including sediment carbon and nutrient cycling. In this study we compared in situ fluxes of carbon dioxide (CO2) from the sediment to the atmosphere, and fluxes of dissolved inorganic nutrients and oxygen across the sediment-water interface, in intact and cleared mangrove and sandflat ecosystems in a temperate estuary. Measurements were made 20 and 25months after mangrove clearance, in summer and winter, respectively. Sediment CO2 efflux was over two-fold higher from cleared than intact mangrove ecosystems at 20 and 25months after mangrove clearance. The higher CO2 efflux from the cleared site was explained by an increase in respiration of dead root material along with sediment disturbance following mangrove clearance. In contrast, sediment CO2 efflux from the sandflat site was negligible (≤9.13±1.18mmolm(-2)d(-1)), associated with lower sediment organic matter content. The fluxes of inorganic nutrients (NH4(+), NOx and PO4(3-)) from intact and cleared mangrove sediments were low (≤20.37±18.66μmolm(-2)h(-)(1)). The highest NH4(+) fluxes were measured at the sandflat site (69.21±13.49μmolm(-2)h(-)(1)). Lower inorganic nutrient fluxes within the cleared and intact mangrove sites compared to the sandflat site were associated with lower abundance of larger burrowing macrofauna. Further, a higher fraction of organic matter, silt and clay content in mangrove sediments may have limited nutrient exchange. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Predicting a change in the order of spring phenology in temperate forests.

    Science.gov (United States)

    Roberts, Adrian M I; Tansey, Christine; Smithers, Richard J; Phillimore, Albert B

    2015-03-02

    The rise in spring temperatures over the past half-century has led to advances in the phenology of many nontropical plants and animals. As species and populations differ in their phenological responses to temperature, an increase in temperatures has the potential to alter timing-dependent species interactions. One species-interaction that may be affected is the competition for light in deciduous forests, where early vernal species have a narrow window of opportunity for growth before late spring species cast shade. Here we consider the Marsham phenology time series of first leafing dates of thirteen tree species and flowering dates of one ground flora species, which spans two centuries. The exceptional length of this time series permits a rare comparison of the statistical support for parameter-rich regression and mechanistic thermal sensitivity phenology models. While mechanistic models perform best in the majority of cases, both they and the regression models provide remarkably consistent insights into the relative sensitivity of each species to forcing and chilling effects. All species are sensitive to spring forcing, but we also find that vernal and northern European species are responsive to cold temperatures in the previous autumn. Whether this sensitivity reflects a chilling requirement or a delaying of dormancy remains to be tested. We then apply the models to projected future temperature data under a fossil fuel intensive emissions scenario and predict that while some species will advance substantially others will advance by less and may even be delayed due to a rise in autumn and winter temperatures. Considering the projected responses of all fourteen species, we anticipate a change in the order of spring events, which may lead to changes in competitive advantage for light with potential implications for the composition of temperate forests. © 2015 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  16. Nekton response to freshwater inputs in a temperate European estuary with regulated riverine inflow.

    Science.gov (United States)

    González-Ortegón, E; Subida, M D; Arias, A M; Baldó, F; Cuesta, J A; Fernández-Delgado, C; Vilas, C; Drake, P

    2012-12-01

    The aim of this 12-year study was to assess the nekton (fish, decapod crustaceans) response to freshwater inputs (rainfall, dam discharges) in a temperate estuary with regulated riverine inflow. Although interannual variability in river discharges to the Guadalquivir estuary has been extremely high since the construction of a dam in 1930, a significant decreasing trend in the dam's discharges has been observed in the last 80 years. During this study, an alternation of wet, standard and dry years occurred in the estuarine area but no significant long-term trend was observed. River discharge, in turn, showed a considerable interannual variability and a significantly decreasing long-term trend. Freshwater inputs had an immediate effect on estuarine salinity and turbidity, and consequently on prey availability (mysids). Although 124 nektonic species were collected, only 47 of them (adding up to 99.7% of total abundance) were regularly present in the estuary: 32 marine migrants, 13 estuarine species and 2 diadromous species. Well-defined temporal changes in species composition and abundance yielded clear seasonal patterns in the estuarine nektonic community. Considerable intermonth and interannual changes were occasionally observed relating to freshwater inputs, mainly in winter/autumn of wet years. Thus, within each two-month period, some significant interannual differences in the nektonic community were also observed, with marine migrants tending to be more abundant in dry years. However, changes in the studied nektonic community did not show long-term trends. In conclusion, natural and human-controlled freshwater inputs currently play a significant role in determining the physicochemical conditions and the biota of the Guadalquivir estuary. However, although freshwater input seemed to transitorily affect the estuarine nekton, either directly (flushing out) or indirectly (through changes in salinity, turbidity and prey availability), a quick reestablishment of the

  17. Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse)

    Science.gov (United States)

    Erguler, Kamil; Smith-Unna, Stephanie E.; Waldock, Joanna; Proestos, Yiannis; Christophides, George K.; Lelieveld, Jos; Parham, Paul E.

    2016-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations. PMID:26871447

  18. Reproductive performance of different breeds of broiler rabbits under sub-temperate climatic conditions

    Directory of Open Access Journals (Sweden)

    D. Kumar

    2013-09-01

    Full Text Available This study was conducted to assess the effect of breed, season, age and weight of doe at mating on reproductive performance of 4 broiler rabbit breeds, Grey Giant, White Giant, Soviet Chinchilla, and New Zealand White, reared under standard management practices in sub-temperate climatic conditions of India. They were first mated at 6 to 7 mo of age, whereupon an extensive breeding system (re-mating after weaning was followed. Weaning was done 42 d after kindling. The data from the records on reproduction consisting of 503 matings and 377 kindlings were analysed. The parameters considered were fertility rate, litter size at birth (LSB, litter weight at birth (LWB, litter size at weaning (LSW, litter weight at weaning (LWW, doe weight at mating (DWM, gestation length and sex ratio. Among 4 breeds, the LSB, LWB and LSW were higher in Grey Giant followed by White Giant, Soviet Chinchilla and New Zealand White. The LSB and LSW in Grey Giant breed differed significantly (P<0.05 from Soviet Chinchilla and New Zealand White. Season had significant (P<0.05 effect on LSW with higher values during spring (5.68±0.24, followed by summer (5.29±0.30, winter (5.13±0.25 and autumn (4.17±0.49. The body weight of doe at service significantly influenced fertility. The fertility increased as body weight increased. The age of the doe at mating had a significant effect on LSW, with higher values for does more than 2 yr and less than 1 yr old compared to 1- to 2-yr old does. The parity did not affect any of the parameters studied. It is concluded that the factors studied affect the reproductive performance of rabbit does. Grey Giant breed showed the highest litter size at birth and weaning, and the highest litter size and weight at weaning was in spring.

  19. Hydrogen induced cold cracking studies on armour grade high strength, quenched and tempered steel weldments

    Energy Technology Data Exchange (ETDEWEB)

    Magudeeswaran, G.; Balasubramanian, V. [Centre for Materials Joining Research (CEMAJOR), Department of Manufacturing Engineering, Annamalai University, Annamalai Nagar 608 002, Tamil Nadu (India); Madhusudhan Reddy, G. [Metal Joining Section, Defence Metallurgical Research Laboratory (DMRL), Kanchanbagh (P.O.) Hyderabad 560 058 Andhra Pradesh (India)

    2008-04-15

    Quenched and tempered (Q and T) steels are prone to hydrogen induced cracking (HIC) in the heat affected zone after welding. The use of austenitic stainless steel (ASS) consumables to weld the above steel was the only available remedy because of higher solubility for hydrogen in austenitic phase. The use of stainless steel consumables for a non-stainless steel base metal is not economical. Hence, alternate consumables for welding Q and T steels and their vulnerability to HIC need to be explored. Recent studies proved that low hydrogen ferritic (LHF) steel consumables can be used to weld Q and T steels, which can give very low hydrogen levels in the weld deposits. In this investigation an attempt has been made to study the influence of welding consumables and welding processes on hydrogen induced cold cracking of armour grade Q and T steel welds by implant testing. Shielded metal arc welding (SMAW) and flux cored arc welding (FCAW) processes were used for making welds using ASS and LHF welding consumables. ASS welds made using FCAW process offered a higher resistance to HIC than all other welds considered in this investigation. (author)

  20. Effects of wave exposure on circulation in a temperate reef environment

    Science.gov (United States)

    Symonds, Graham; Zhong, Liejun; Mortimer, Nick A.

    2011-09-01

    Observations of waves and currents in a temperate reef environment off southwestern Western Australia over a period of 1 year reveal the relative importance of wind and wave forcing. During periods of low waves, linear regression analysis shows alongshore currents seaward and shoreward of the reef line are reasonably well predicted using 1% and 0.5% of the wind speed, respectively. However, shoreward of the reef line anomalously strong currents were often observed during periods of light or even opposing winds and the mean sea surface was elevated relative to offshore of the reefs. These anomalous currents and elevated sea level occur during periods of high waves and both are correlated with the root-mean-square wave height seaward of the reefs, similar to what has been observed in coral reef environments. The observations were simulated with the numerical model XBeach which includes radiation stress forcing due to the presence of the waves. The model was also used to examine the dynamics of the wave-driven flow in terms of the momentum balance. As on a coral reef, through the surf zone over the reef bottom, friction is balanced by the sum of the radiation stress gradient and pressure gradient. Away from the reefs the radiation stress gradients are small and the momentum balance is between bottom friction and pressure gradient.

  1. Domestic queens under natural temperate photoperiod do not manifest seasonal anestrus.

    Science.gov (United States)

    Faya, M; Carranza, A; Priotto, M; Abeya, M; Diaz, J D; Gobello, C

    2011-11-01

    Domestic cat seasonality between the tropics and the arctic zones is scarcely described and results are inconsistent. The aim of this study was to describe domestic feline seasonal patterns under a natural temperate photoperiod. A total of 372 estrous cycles were studied in 34 post pubertal cats during 900 days. The queens were housed in a cat colony (31°25' South Latitude, 64°11' West Longitude), acclimated under natural photoperiod and daily observed for reproductive behavior. Vaginal cytology was conducted three times a week. For each cat the number of estrous cycles and days in estrus per month for each year were recorded. The months of the year were grouped in four periods of 3 months each according to day length and photoperiod. Comparisons of estrous days among periods were performed by ANOVA for repeated measures. All the cats had estrous cycles throughout the year without intervals of anestrus. Mean number of estrous days differed among the periods (Pphotoperiod being greater (12.5±0.6) to those of descending photoperiod either with long (8.9±0.7) or short (9.3±0.7) days. When the two periods with ascending day lengths were merged and compared to the two periods with descending day lengths merged, the number of estrous days were greater when day length ascended (Pphotoperiod have estrous cycles throughout the year showing peak activity the months with increasing photoperiod. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Emergent Toxins in North Atlantic Temperate Waters: A Challenge for Monitoring Programs and Legislation

    Directory of Open Access Journals (Sweden)

    Marisa Silva

    2015-03-01

    Full Text Available Harmful Algal Blooms (HAB are complex to manage due to their intermittent nature and their severe impact on the economy and human health. The conditions which promote HAB have not yet been fully explained, though climate change and anthropogenic intervention are pointed as significant factors. The rise of water temperature, the opening of new sea canals and the introduction of ship ballast waters all contribute to the dispersion and establishment of toxin-producing invasive species that promote the settling of emergent toxins in the food-chain. Tetrodotoxin, ciguatoxin, palytoxin and cyclic imines are commonly reported in warm waters but have also caused poisoning incidents in temperate zones. There is evidence that monitoring for these toxins exclusively in bivalves is simplistic and underestimates the risk to public health, since new vectors have been reported for these toxins and as well for regulated toxins such as PSTs and DSTs. In order to avoid public health impacts, there is a need for adequate monitoring programs, a need for establishing appropriate legislation, and a need for optimizing effective methods of analysis. In this review, we will compile evidence concerning emergent marine toxins and provide data that may indicate the need to restructure the current monitoring programs of HAB.

  3. Emergent toxins in North Atlantic temperate waters: a challenge for monitoring programs and legislation.

    Science.gov (United States)

    Silva, Marisa; Pratheepa, Vijaya K; Botana, Luis M; Vasconcelos, Vitor

    2015-03-16

    Harmful Algal Blooms (HAB) are complex to manage due to their intermittent nature and their severe impact on the economy and human health. The conditions which promote HAB have not yet been fully explained, though climate change and anthropogenic intervention are pointed as significant factors. The rise of water temperature, the opening of new sea canals and the introduction of ship ballast waters all contribute to the dispersion and establishment of toxin-producing invasive species that promote the settling of emergent toxins in the food-chain. Tetrodotoxin, ciguatoxin, palytoxin and cyclic imines are commonly reported in warm waters but have also caused poisoning incidents in temperate zones. There is evidence that monitoring for these toxins exclusively in bivalves is simplistic and underestimates the risk to public health, since new vectors have been reported for these toxins and as well for regulated toxins such as PSTs and DSTs. In order to avoid public health impacts, there is a need for adequate monitoring programs, a need for establishing appropriate legislation, and a need for optimizing effective methods of analysis. In this review, we will compile evidence concerning emergent marine toxins and provide data that may indicate the need to restructure the current monitoring programs of HAB.

  4. A temperate rocky super-Earth transiting a nearby cool star.

    Science.gov (United States)

    Dittmann, Jason A; Irwin, Jonathan M; Charbonneau, David; Bonfils, Xavier; Astudillo-Defru, Nicola; Haywood, Raphaëlle D; Berta-Thompson, Zachory K; Newton, Elisabeth R; Rodriguez, Joseph E; Winters, Jennifer G; Tan, Thiam-Guan; Almenara, Jose-Manuel; Bouchy, François; Delfosse, Xavier; Forveille, Thierry; Lovis, Christophe; Murgas, Felipe; Pepe, Francesco; Santos, Nuno C; Udry, Stephane; Wünsche, Anaël; Esquerdo, Gilbert A; Latham, David W; Dressing, Courtney D

    2017-04-19

    M dwarf stars, which have masses less than 60 per cent that of the Sun, make up 75 per cent of the population of the stars in the Galaxy. The atmospheres of orbiting Earth-sized planets are observationally accessible via transmission spectroscopy when the planets pass in front of these stars. Statistical results suggest that the nearest transiting Earth-sized planet in the liquid-water, habitable zone of an M dwarf star is probably around 10.5 parsecs away. A temperate planet has been discovered orbiting Proxima Centauri, the closest M dwarf, but it probably does not transit and its true mass is unknown. Seven Earth-sized planets transit the very low-mass star TRAPPIST-1, which is 12 parsecs away, but their masses and, particularly, their densities are poorly constrained. Here we report observations of LHS 1140b, a planet with a radius of 1.4 Earth radii transiting a small, cool star (LHS 1140) 12 parsecs away. We measure the mass of the planet to be 6.6 times that of Earth, consistent with a rocky bulk composition. LHS 1140b receives an insolation of 0.46 times that of Earth, placing it within the liquid-water, habitable zone. With 90 per cent confidence, we place an upper limit on the orbital eccentricity of 0.29. The circular orbit is unlikely to be the result of tides and therefore was probably present at formation. Given its large surface gravity and cool insolation, the planet may have retained its atmosphere despite the greater luminosity (compared to the present-day) of its host star in its youth. Because LHS 1140 is nearby, telescopes currently under construction might be able to search for specific atmospheric gases in the future.

  5. Recent carbonate sedimentation on Balearic platform: model for temperate-climate carbonate shelves

    Energy Technology Data Exchange (ETDEWEB)

    Fornos, J.; Rodriguez-Perea, A.; Massuti, C.; Pomar, L.; Acosta, J.; Herranz, P.; Sanz, J.L.

    1989-03-01

    Existing models for carbonate sedimentation on continental platforms are derived from the study of modern carbonate platforms in tropical climates. The Balearic platform in the western Mediterranean provides a new model for carbonate sedimentation in a temperature, semiarid climate. On most of the continental shelf around the Balearic Islands, modern sediments are exclusively bioclastic carbonates. Shoreline carbonate sediments are bioclastic sands and muds accumulating in beach-dune systems without significant tidal influence (there are no astronomical tides in the western Mediterranean ). From the upper shoreface to 35 m deep, the sandy bottom is extensively colonized by sea grass (Posidonia oceanica), the rhizomes and roots of which form a rigid entrapment that retains the sediment derived from calcareous organisms living within the sea grass and from calcareous epiphytes living on the stems and leaves. Archeological dating establishes a rate of vertical accretion in this zone of 10/sup 3/ Bubnoff units (1 Bubnoff unit = 1 mm/1000 years). Between depths of 40 and 60 m, carbonate sands are composed predominantly or red-algal fragments. Intensely bioturbated wave ripples occur in environments dominated by laminar red algae (Lithothamnium and Phymatolithon). Below depths of 60 m, coarse sediment produced by rhodolitic and ramose red algae is deposited in areas of tens to hundreds of meters in size. Biogenic buildups up to 2 m high occur in sandy areas as well as in deeper muddy areas. At the same depth in open-platform zones, the bottom topography is characterized by large hummocks several hundred meters across. From the horizontal distribution of facies, it is possible to construct the probable vertical sequence of lithofacies which would characterize carbonates accumulating on a temperate-climate carbonate shelf. Many of these lithofacies are recognized in upper Miocene limestones on the Balearic Islands.

  6. A temperate rocky super-Earth transiting a nearby cool star

    Science.gov (United States)

    Dittmann, Jason A.; Irwin, Jonathan M.; Charbonneau, David; Bonfils, Xavier; Astudillo-Defru, Nicola; Haywood, Raphaëlle D.; Berta-Thompson, Zachory K.; Newton, Elisabeth R.; Rodriguez, Joseph E.; Winters, Jennifer G.; Tan, Thiam-Guan; Almenara, Jose-Manuel; Bouchy, François; Delfosse, Xavier; Forveille, Thierry; Lovis, Christophe; Murgas, Felipe; Pepe, Francesco; Santos, Nuno C.; Udry, Stephane; Wünsche, Anaël; Esquerdo, Gilbert A.; Latham, David W.; Dressing, Courtney D.

    2017-04-01

    M dwarf stars, which have masses less than 60 per cent that of the Sun, make up 75 per cent of the population of the stars in the Galaxy. The atmospheres of orbiting Earth-sized planets are observationally accessible via transmission spectroscopy when the planets pass in front of these stars. Statistical results suggest that the nearest transiting Earth-sized planet in the liquid-water, habitable zone of an M dwarf star is probably around 10.5 parsecs away. A temperate planet has been discovered orbiting Proxima Centauri, the closest M dwarf, but it probably does not transit and its true mass is unknown. Seven Earth-sized planets transit the very low-mass star TRAPPIST-1, which is 12 parsecs away, but their masses and, particularly, their densities are poorly constrained. Here we report observations of LHS 1140b, a planet with a radius of 1.4 Earth radii transiting a small, cool star (LHS 1140) 12 parsecs away. We measure the mass of the planet to be 6.6 times that of Earth, consistent with a rocky bulk composition. LHS 1140b receives an insolation of 0.46 times that of Earth, placing it within the liquid-water, habitable zone. With 90 per cent confidence, we place an upper limit on the orbital eccentricity of 0.29. The circular orbit is unlikely to be the result of tides and therefore was probably present at formation. Given its large surface gravity and cool insolation, the planet may have retained its atmosphere despite the greater luminosity (compared to the present-day) of its host star in its youth. Because LHS 1140 is nearby, telescopes currently under construction might be able to search for specific atmospheric gases in the future.

  7. Quantitative characteristics of the littoral fauna of Grønfjorden Gulf (Spitsbergen) during winter and spring of 2016.

    Science.gov (United States)

    Zimina, O L; Meshcheryakov, N I

    2017-05-01

    The first description of the quantitative and qualitative compositions of the littoral fauna of Grønfjorden Gulf during the winter and spring period is given. Granulometric analysis of the surface sediments of the littoral has been performed. Thirty invertebrate taxa that did not leave the littoral zone during wintertime and could survive complete freezing during ebb have been identified. Species diversity and population density of the invertebrates were shown to depend on the granulometric size composition of the surface sediments.

  8. Method to Predict Tempering of Steels Under Non-isothermal Conditions

    Science.gov (United States)

    Poirier, D. R.; Kohli, A.

    2017-05-01

    A common way of representing the tempering responses of steels is with a "tempering parameter" that includes the effect of temperature and time on hardness after hardening. Such functions, usually in graphical form, are available for many steels and have been applied for isothermal tempering. In this article, we demonstrate that the method can be extended to non-isothermal conditions. Controlled heating experiments were done on three grades in order to verify the method.

  9. Timing of the compensation of winter respiratory carbon losses provides explanatory power for net ecosystem productivity of forests

    DEFF Research Database (Denmark)

    Haeni, M.; Zweifel, R.; Eugster, W.

    2017-01-01

    , and Australia, using different NEPc integration methods. We found cDOY to be a particularly powerful predictor for NEPc of temperate evergreen needle-leaf forests (R2 = 0.58) and deciduous broadleaf forests (R2 = 0.68). In general, the latest cDOY correlated with the lowest NEPc. The explanatory power of c......Accurate predictions of net ecosystem productivity (NEPc) of forest ecosystems are essential for climate change decisions and requirements in the context of national forest growth and greenhouse gas inventories. However, drivers and underlying mechanisms determining NEPc (e.g. climate, nutrients......) are not entirely understood yet, particularly when considering the influence of past periods. Here we explored the explanatory power of the compensation day (cDOY) —defined as the day of year when winter net carbon losses are compensated by spring assimilation— for NEPc in 26 forests in Europe, North America...

  10. Systematics of the hypervariable Moraea tripetala complex (Iridaceae: Iridoideae of the southern African winter rainfall zone

    Directory of Open Access Journals (Sweden)

    P. Goldblatt

    2012-12-01

    Full Text Available Field and laboratory research has shown that the Moraea tripetala complex of western South Africa, traditionally treated as a single species, sometimes with two additional varieties, has a pattern of morphological and cytological variation too complex to be accommodated in a single species. Variation in floral structure, especially the shape of the inner tepals, degree of union of the filaments, anther length and pollen colour form coherent patterns closely correlated with morphology of the corm tunics, mode of vegetative reproduction, and in some instances capsule and seed shape and size. The morphological patterns also correlate with geography, flowering time and sometimes habitat. It is especially significant that different variants of the complex may co-occur, each with overlapping or separate flowering times, a situation that conflicts with a single species taxonomy. We propose recognizing nine species and three additional subspecies for plants currently assigned to M. tripetala. M. grandis, from the western Karoo, has virtually free filaments and leaves often ± plane distally; closely allied M. amabilis, also with ± free filaments and often hairy leaves, is centred in the western Karoo and Olifants River Valley. Its range overlaps that of M. cuspidata, which has narrowly channelled, smooth leaves, linear inner tepals spreading distally and filaments united for up to 1.5 mm. M. decipiens from the Piketberg, M. hainebachiana, a local endemic of coastal limestone fynbos in the Saldanha District, M. ogamana from seasonally wet lowlands, and early flowering M. mutila constitute the remaining species of the complex in the southwestern Western Cape. M. helmei, a local endemic of middle elevations in the Kamiesberg, Namaqualand, has small flowers with short, tricuspidate inner tepals. All but M. amabilis and M. mutila are new species. We divide M. tripetala sensu stricto into three subspecies: widespread subsp. tripetala, subsp. violacea from the interior Cape flora region, and late-flowering subsp. jacquiniana from the Cape Peninsula and surrounding mountains.

  11. Holocene climate variability in the winter rainfall zone of South Africa

    NARCIS (Netherlands)

    Weldeab, S.; Stuut, J.-B.W.; Schneider, R.R.; Siebel, W.

    2013-01-01

    We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes, grain size of terrigenous fraction, and d18O and d13C in tests of Neogloboquadrina pachyderma (sinistral) from a marine sediment sequence recovered off the Orange River. The records

  12. Have winter fuel payments reduced excess winter mortality in England and Wales?

    Science.gov (United States)

    Iparraguirre, J

    2015-03-01

    The historical series of excess winter mortality (EWM) in England and Wales presents a negative trend. Winter fuel payments (WFPs) are the most important benefits for people aged 65 or over directly related to Winter Mortality in the UK. This study presents a time series analysis of the direct effect of WFPs on EWM in England and Wales. We find a significant structural break in trend and volatility in the EWM series in England and Wales in 1999-2000. After controlling for a number of covariates, an ARIMA-X model finds that WFPs can account for almost half of the reduction in EWM in England and Wales since 1999/2000. Almost half of the reduction in EWM since 1999/2000 is attributable to WFPs. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Joints in Tempered Glass Using Glass Dowel Discs

    DEFF Research Database (Denmark)

    Nielsen, Jens Henrik; Poulsen, Peter Noe

    One of the major reasons for using glass in structures is its transparency; however, traditional mechanical joints such as friction joints and steel dowel pinned connections are compromising the transparency. The present paper describes a novel joint which is practically maintaining the complete...... transparency of the glass. This is achieved by using a dowel disc made entirely of tempered glass. The concept of the joint is proved by pilot tests and numerical models. From the work it is seen that the load-carrying capacity of such a connection is similar to what is found for traditionally in-plane loaded...

  14. Transport in the spatially tempered, fractional Fokker-Planck equation

    Science.gov (United States)

    Kullberg, A.; del-Castillo-Negrete, D.

    2012-06-01

    A study of truncated Lévy flights in super-diffusive transport in the presence of an external potential is presented. The study is based on the spatially tempered, fractional Fokker-Planck (TFFP) equation in which the fractional diffusion operator is replaced by a tempered fractional diffusion (TFD) operator. We focus on harmonic (quadratic) potentials and periodic potentials with broken spatial symmetry. The main objective is to study the dependence of the steady-state probability density function (PDF), and the current (in the case of periodic potentials) on the level of tempering, λ, and on the order of the fractional derivative in space, α. An expansion of the TFD operator for large λ is presented, and the corresponding equation for the coarse grained PDF is obtained. The steady-state PDF solution of the TFFP equation for a harmonic potential is computed numerically. In the limit λ → ∞, the PDF approaches the expected Boltzmann distribution. However, nontrivial departures from this distribution are observed for finite (λ > 0) truncations, and α ≠ 2. In the study of periodic potentials, we use two complementary numerical methods: a finite-difference scheme based on the Grunwald-Letnikov discretization of the truncated fractional derivatives and a Fourier-based spectral method. In the limit λ → ∞, the PDFs converges to the Boltzmann distribution and the current vanishes. However, for α ≠ 2, the PDF deviates from the Boltzmann distribution and a finite non-equilibrium ratchet current appears for any λ > 0. The current is observed to converge exponentially in time to the steady-state value. The steady-state current exhibits algebraical decay with λ, as J ˜ λ-ζ, for α ⩾ 1.75. However, for α ⩽ 1.5, the steady-state current decays exponentially with λ, as J ˜ e-ξλ. In the presence of an asymmetry in the TFD operator, the tempering can lead to a current reversal. A detailed numerical study is presented on the dependence of the

  15. Transport in the spatially tempered, fractional Fokker-Planck equation

    Energy Technology Data Exchange (ETDEWEB)

    Kullberg, A. [University of California, Los Angeles; Del-Castillo-Negrete, Diego B [ORNL

    2012-01-01

    A study of truncated Levy flights in super-diffusive transport in the presence of an external potential is presented. The study is based on the spatially tempered, fractional Fokker-Planck (TFFP) equation in which the fractional diffusion operator is replaced by a tempered fractional diffusion (TFD) operator. We focus on harmonic (quadratic) potentials and periodic potentials with broken spatial symmetry. The main objective is to study the dependence of the steady-state probability density function (PDF), and the current (in the case of periodic potentials) on the level of tempering, lambda, and on the order of the fractional derivative in space, alpha. An expansion of the TFD operator for large lambda is presented, and the corresponding equation for the coarse grained PDF is obtained. The steady-state PDF solution of the TFFP equation for a harmonic potential is computed numerically. In the limit lambda -> infinity, the PDF approaches the expected Boltzmann distribution. However, nontrivial departures from this distribution are observed for finite (lambda > 0) truncations, and alpha not equal 2. In the study of periodic potentials, we use two complementary numerical methods: a finite-difference scheme based on the Grunwald-Letnikov discretization of the truncated fractional derivatives and a Fourier-based spectral method. In the limit lambda -> infinity, the PDFs converges to the Boltzmann distribution and the current vanishes. However, for alpha not equal 2, the PDF deviates from the Boltzmann distribution and a finite non-equilibrium ratchet current appears for any lambda > 0. The current is observed to converge exponentially in time to the steady-state value. The steady-state current exhibits algebraical decay with lambda, as J similar to lambda(-zeta), for alpha >= 1.75. However, for alpha <= 1.5, the steady-state current decays exponentially with lambda, as J similar to e(-xi lambda). In the presence of an asymmetry in the TFD operator, the tempering can lead

  16. Tempered fractional Feynman-Kac equation: Theory and examples.

    Science.gov (United States)

    Wu, Xiaochao; Deng, Weihua; Barkai, Eli

    2016-03-01

    Functionals of Brownian and non-Brownian motions have diverse applications and attracted a lot of interest among scientists. This paper focuses on deriving the forward and backward fractional Feynman-Kac equations describing the distribution of the functionals of the space and time-tempered anomalous diffusion, belonging to the continuous time random walk class. Several examples of the functionals are explicitly treated, including the occupation time in half-space, the first passage time, the maximal displacement, the fluctuations of the occupation fraction, and the fluctuations of the time-averaged position.

  17. VT Data - Zoning 20120709, Huntington

    Data.gov (United States)

    Vermont Center for Geographic Information — Zoning district data for the Town of Huntington, Vermont. For details regarding each zoning district refer to the current zoning regulations on town of Huntington's...

  18. VT Data - Zoning 20130529, Readsboro

    Data.gov (United States)

    Vermont Center for Geographic Information — Models a municipality’s zoning zones and related information. Data were originally created by John Whitman of Readsboro in 2004 as prooposed zoning, and were adopted...

  19. Spectrum of winter dermatoses in rural Yemen.

    Science.gov (United States)

    Al-Kamel, Mohamed A

    2016-05-01

    Surveys that have been carried out to determine the prevalence of skin diseases in rural Yemen are scarce or not available. To investigate the spectrum of winter dermatoses in a rural Yemeni community. A retrospective study was conducted at the dermatology outpatient clinic of the Al-Helal Specialized Hospital (Radaa' district of Al Bayda' Governorate) using data analysis of 700 selected records of patients managed during four months of the 2013-14 winter season. Seven hundred patients with 730 diseases were reported in this study; the major bulk of patients (46.57%) were in the >18-40-year age group, and females outnumbered males. By far, dermatitis, eczematous, and allergic disorders (38.49%) topped the list of the most frequent skin disorders groups, followed by skin infections and infestations (20%) and the pigmentary disorders (13.70%) group. Contact dermatitis (10.68%) was the most prevalent skin disorder, followed by hyperpigmentations (8.77%), acne (8.08%), viral infections (5.75%), atopic dermatitis (5.62%), and parasitic infestations (5.34%). This survey has documented the spectrum of winter dermatoses in a rural Yemeni community but also reflects the pattern of common dermatoses in the whole country. Dermatitis, eczematous, and allergic disorders, skin infections, and pigmentary disorders are the commonest groups. Contact dermatitis is the most prevalent disorder, and leishmaniasis is the most prevalent skin infectious disease. Climate, occupational, social, and environmental factors are the main contributors. Such statistics can form an important basis for community-based health policies. © 2015 The International Society of Dermatology.

  20. Genetic and Morphological Diversity of Temperate and Tropical Isolates of Phytophthora capsici.

    Science.gov (United States)

    Bowers, J H; Martin, F N; Tooley, P W; Luz, E D M N

    2007-04-01

    ABSTRACT Phytophthora capsici is a diverse species causing disease on a broad range of both temperate and tropical plants. In this study, we used cultural characteristics, amplified fragment length polymorphism (AFLP), and DNA sequence analyses of the ribosomal internal transcribed spacer (ITS) region and mitochondrial cytochrome oxidase II (cox II) genes to characterize temperate and tropical isolates from a wide range of host species. All but one temperate isolate grew at 35 degrees C, while all tropical isolates did not. All but two tropical isolates formed chlamydospores, while temperate isolates did not. There was strong bootstrap support for separation of temperate and tropical isolates using AFLP analysis; however, the temperate isolates appeared as a subgroup within the observed variation of the tropical isolates. The majority of temperate isolates clustered within a single clade with low variation regardless of host or geographical origin, while the tropical isolates were more variable and grouped into three distinct clades. Two clades of tropical isolates grouped together and were affiliated closely with the temperate isolates, while the third tropical clade was more distantly related. Phylogenetic analysis of the ITS regions resulted in similar groupings and variation within and between the temperate and tropical isolates as with the AFLP results. Sequence divergence among isolates and clades was low, with more variation within the tropical isolates than within the temperate isolates. Analysis of other species revealed shorter branch lengths separating temperate and tropical isolates than were observed in comparisons among other phylogenetically closely related species in the genus. Analysis of cox II sequence data was less clear. Although the temperate and tropical isolates grouped together apart from other species, there was no bootstrap support for separating these isolates. Restriction fragment length polymorphism (RFLP) analysis of the ITS regions