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Sample records for east siberian cryophilic

  1. High rate of N2 fixation by East Siberian cryophilic soil bacteria as determined by measuring acetylene reduction in nitrogen-poor medium solidified with gellan gum.

    Science.gov (United States)

    Hara, Shintaro; Hashidoko, Yasuyuki; Desyatkin, Roman V; Hatano, Ryusuke; Tahara, Satoshi

    2009-05-01

    For evaluating N(2) fixation of diazotrophic bacteria, nitrogen-poor liquid media supplemented with at least 0.5% sugar and 0.2% agar are widely used for acetylene reduction assays. In such a soft gel medium, however, many N(2)-fixing soil bacteria generally show only trace acetylene reduction activity. Here, we report that use of a N(2) fixation medium solidified with gellan gum instead of agar promoted growth of some gellan-preferring soil bacteria. In a soft gel medium solidified with 0.3% gellan gum under appropriate culture conditions, bacterial microbiota from boreal forest bed soils and some free-living N(2)-fixing soil bacteria isolated from the microbiota exhibited 10- to 200-fold-higher acetylene reduction than those cultured in 0.2% agar medium. To determine the N(2) fixation-activating mechanism of gellan gum medium, qualitative differences in the colony-forming bacterial components from tested soil microbiota were investigated in plate cultures solidified with either agar or gellan gum for use with modified Winogradsky's medium. On 1.5% agar plates, apparently cryophilic bacterial microbiota showed strictly distinguishable microbiota according to the depth of soil in samples from an eastern Siberian Taiga forest bed. Some pure cultures of proteobacteria, such as Pseudomonas fluorescens and Burkholderia xenovorans, showed remarkable acetylene reduction. On plates solidified with 1.0% gellan gum, some soil bacteria, including Luteibacter sp., Janthinobacterium sp., Paenibacillus sp., and Arthrobacter sp., uniquely grew that had not grown in the presence of the same inoculants on agar plates. In contrast, Pseudomonas spp. and Burkholderia spp. were apparent only as minor colonies on the gellan gum plates. Moreover, only gellan gum plates allowed some bacteria, particularly those isolated from the shallow organic soil layer, to actively swarm. In consequence, gellan gum is a useful gel matrix to bring out growth potential capabilities of many soil

  2. Methane from the East Siberian Arctic shelf

    DEFF Research Database (Denmark)

    Petrenko...[], Vasilii V.; Etheridge, David M.

    2010-01-01

    that the release of Arctic CH4 was implied in previous climate shifts as well as in the recently renewed rise in atmospheric CH4. These claims are not supported by all the literature they cite. Their reference 5 (1) presents measurements of emissions only of carbon dioxide, not CH4. Their reference 8 (2), a study...... that is changing in response to Arctic warming. Shakhova et al. do acknowledge these distinctions, but in these times of enhanced scrutiny of climate change science, it is important to communicate all evidence to the scientific community and the public clearly and accurately......In their Report “Extensive methane venting to the atmosphere from sediments of the East Siberian Arctic Shelf” (5 March, p. 1246), N. Shakhova et al. write that methane (CH4) release resulting from thawing Arctic permafrost “is a likely positive feedback to climate warming.” They add...

  3. The De Long Trough: a newly discovered glacial trough on the East Siberian continental margin

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    M. O'Regan

    2017-09-01

    Full Text Available Ice sheets extending over parts of the East Siberian continental shelf have been proposed for the last glacial period and during the larger Pleistocene glaciations. The sparse data available over this sector of the Arctic Ocean have left the timing, extent and even existence of these ice sheets largely unresolved. Here we present new geophysical mapping and sediment coring data from the East Siberian shelf and slope collected during the 2014 SWERUS-C3 expedition (SWERUS-C3: Swedish – Russian – US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions. The multibeam bathymetry and chirp sub-bottom profiles reveal a set of glacial landforms that include grounding zone formations along the outer continental shelf, seaward of which lies a  >  65 m thick sequence of glacio-genic debris flows. The glacial landforms are interpreted to lie at the seaward end of a glacial trough – the first to be reported on the East Siberian margin, here referred to as the De Long Trough because of its location due north of the De Long Islands. Stratigraphy and dating of sediment cores show that a drape of acoustically laminated sediments covering the glacial deposits is older than ∼ 50 cal kyr BP. This provides direct evidence for extensive glacial activity on the Siberian shelf that predates the Last Glacial Maximum and most likely occurred during the Saalian (Marine Isotope Stage (MIS 6.

  4. Effect of the East Siberian barrier on the echinoderm dispersal in the Arctic Ocean

    Science.gov (United States)

    Mironov, A. N.; Dilman, A. B.

    2010-06-01

    The distributional patterns were analyzed for 43 species and 33 genera of echinoderms in the Laptev and East Siberian seas and for 59 species and 35 genera of the asteroid species in the Arctic Ocean. The probable colonization route through the Arctic was suggested for each species based on (1) the distributional patterns of the Arctic species, (2) the distributional patterns of the closely related species, and (3) the location of the center of the diversity of the species belonging to a certain genus. The species of the Pacific origin prevailed in the asteroid fauna of the Arctic seas. The asteroid species diversity and the ratio of the species of Pacific origin decreased from the Barents towards the Laptev Sea and increased, respectively, in the East Siberian and the Chukchee seas. The species range limits were found for 19 species in the East Siberian Sea compared to only 3 species in the Laptev Sea. The East Siberian Sea was a limiting area for the dispersal of four species groups: (1) invaders from the North Pacific dispersing along the Asian coast of the Arctic (shallow-water stenobathic species), (2) invaders from the North Pacific dispersing along the American coast of the Arctic and further on back into the Arctic along the Eurasian coast (secondarily Atlantic species); (3) originally invaders from the Northern Atlantic; (4) representatives of the Arctic autochthonous fauna. A great width of the biotic boundaries (i.e., the zones of the species range boundaries crowding) was typical for the Arctic Basin, which was a sign of their young geological age.

  5. New Result on Methane Emissions from the East Siberian Arctic Shelf

    Science.gov (United States)

    Shakhova, N. E.; Semiletov, I. P.; Sergienko, V.; Lobkovsky, L. I.; Dmitrevsky, N.; Salyuk, A.; Yusupov, V.; Salomatin, A.; Karnaukh, V.; Chernykh, D.; Kosmach, D.; Ananiev, R.; Meluzov, A.; Nicolsky, D.; Panteleev, G.

    2013-12-01

    Methane release from thawing Arctic permafrost is one of the few carbon-climate mechanisms that could change projected climate forcing substantially in this century. Venting of methane to the atmosphere in the East Siberian Arctic Shelf, the world's largest yet shallowest shelf, was recently shown to be ubiquitous. Here we report results of multi-year investigations performed in the coastal East Siberian Arctic Shelf (ESAS), where invasion of relatively warm seawater occurred most recently. Observational data and simulation of the warming effect of seawater on subsea permafrost suggest that disintegrating subsea permafrost allows formation of migration pathways for methane bubbles released from the sea floor. Sonar data collected in the coastal area and in the mid-outer shelf area together with data, obtained using high-resolution high-speed video camera, enabled area-weighted methane fluxes to be estimated. New factors controlling spatial and temporal variability of methane fluxes on the ESAS were found. In the outer shelf, it was shown that methane releases from the seabed via strong flare-like ebullition that produces fluxes much greater than on the shallow shelf, where largely frozen sediments restrict fluxes. The coastward progression of thawing subsea permafrost in a warming Arctic could potentially result in a significant increase in methane emissions from the East Siberian Arctic Shelf.

  6. Tectonics of East Siberian Sea Basin and its influence on petroleum systems

    Science.gov (United States)

    Karpov, Yury; Antonina, Stoupakova; Anna, Suslova; Mariia, Agasheva

    2016-04-01

    The East Siberian Sea basin (ESSB) is the largest part of the Siberian Arctic shelf, extending for over 1000 km from New Siberian Islands archipelago to Wrangel Island. Nowadays East Siberian Sea margin is considered as a region with probable high petroleum potential. This part of Russian Arctic shelf is the least studied. The major problems in geological investigation of East Siberian Sea shelf are absence of deep wells in area and low seismic exploration maturity. Only general conclusions on its geology and hydrocarbon systems can be drawn based on limited seismic, gravity and magnetic data, supported by projection of onshore geological data to offshore. So, that's why now only complex geological and seismic stratigraphy interpretations are provided. Today we have several concepts and can summarize the tectonic history of the basin. The basin is filled with siliclastic sediments. In the deepest depocentres sediments thickness exceed 8 km in average. Seismic data was interpreted using methods of seismic stratigraphy. Stratigraphic interpretation was possible to achieve because seismic reflections follow chronostratigraphic correlations. Finally, main seismic horizons were indicated. Each indicated horizon follows regional stratigraphic unconformity. In case of absence of deep wells in ESSB, we can only prove possible source rocks by projection of data about New Siberian Islands archipelago source rocks on offshore. The petroleum potential of these rocks was investigated by several authors [1, 2, 3]. Perspective structures, investigated in ESSB were founded out by comparing seismogeological cross-sections with explored analogs in other Russian and foreign onshore and offshore basins. The majority of structures could be connected with stratigraphic and fault traps. New data on possible petroleum plays was analyzed, large massif of data on geology and tectonic history of the region was collected, so now we can use method of basin modelling to evaluate hydrocarbon

  7. Terpenoid emissions from fully grown East Siberian Larix cajanderi trees

    Directory of Open Access Journals (Sweden)

    M. K. Kajos

    2013-03-01

    Full Text Available While emissions of many volatile compounds, such as terpenoids, have been studied quite intensively in North American and Scandinavian boreal forests, the vast Siberian boreal forests have remained largely unexplored by experimental emission studies. In this study the shoot scale terpenoid emission rates from mature Larix cajanderi trees growing in their natural habitat in Eastern Siberia were measured. Dynamic flow-through enclosure technique was applied for adsorbent sampling (Tenax-TA and Carbopack-B used as adsorbents, and the samples were analysed offline with a gas chromatograph. The emissions were dominated by monoterpenes, which constituted between 61 and 92% of the total emission. About half of the monoterpene emissions comprised of Δ3-carene; α- and β-pinene had significant emissions as well. Linalool emissions were also substantial, especially in June. Sesquiterpenes accounted for less than 3% and isoprene less than 1% of the total emissions. Based on the measured emission rates, the relative atmospheric concentration of each compound was estimated. Monoterpenes were the species with the highest relative concentration, while linalool and sesquiterpenes had a notably smaller contribution to the estimated atmospheric concentration than to the emission rates. Temperature dependent pool algorithm with a constant β (0.09 °C−1 for monoterpenes and 0.143 °C−1 for sesquiterpenes was used to normalize the measured emission data. For monoterpenes the emission potential varied between 0.5–18.5 μg gdw−1 h−1 and for sesquiterpenes between 0.02 and 0.4 μg gdw−1 h−1.

  8. Terpenoid emissions from fully grown east Siberian Larix cajanderi trees

    Directory of Open Access Journals (Sweden)

    M. K. Kajos

    2013-07-01

    Full Text Available While emissions of many biogenic volatile organic compounds (BVOCs, such as terpenoids, have been studied quite intensively in North American and Scandinavian boreal forests, the vast Siberian boreal forests have remained largely unexplored by experimental emission studies. In this study the shoot-scale terpenoid emission rates from two mature Larix cajanderi trees growing in their natural habitat in eastern Siberia were measured at the Spasskaya Pad flux measurement site (62°15´18.4" N, 129°37´07.9" E located on the western bank of the Lena river. The measurements were conducted during three campaigns: 3–24 June, 8–26 July, and 14–30 August, in the summer of 2009. A dynamic flow-through enclosure technique was applied for adsorbent sampling, and the samples were analysed offline with a gas chromatograph. Between 29 and 45 samples were taken from each shoot during all three campaigns. Seven different monoterpenes, six different sesquiterpenes, linalool isoprene, and 2-methyl-3-buten-2-ol (MBO were identified. The monthly median value of the total terpenoid emissions varied between 0.006 and 10.6 μg gdw−1 h−1. The emissions were dominated by monoterpenes, which constituted between 61 and 92% of the total emissions. About half of the monoterpene emissions were comprised of Δ 3-carene; α- and β-pinene had significant emissions as well. Linalool emissions were also substantial, comprising 3–37% of the total emissions, especially in June. Sesquiterpenes accounted for less than 3% and isoprene less than 1% of the total emissions. Based on the measured emission rates, the relative atmospheric concentration of each compound was estimated. Monoterpenes were the species with the highest relative concentration, while linalool and sesquiterpenes had a notably smaller contribution to the estimated atmospheric concentration than to the emission rates. A temperature-dependent pool algorithm with a constant β (0.09 °C−1 for monoterpenes

  9. Terpenoid emissions from fully grown east Siberian Larix cajanderi trees

    Science.gov (United States)

    Kajos, M. K.; Hakola, H.; Holst, T.; Nieminen, T.; Tarvainen, V.; Maximov, T.; Petäjä, T.; Arneth, A.; Rinne, J.

    2013-07-01

    While emissions of many biogenic volatile organic compounds (BVOCs), such as terpenoids, have been studied quite intensively in North American and Scandinavian boreal forests, the vast Siberian boreal forests have remained largely unexplored by experimental emission studies. In this study the shoot-scale terpenoid emission rates from two mature Larix cajanderi trees growing in their natural habitat in eastern Siberia were measured at the Spasskaya Pad flux measurement site (62°15´18.4" N, 129°37´07.9" E) located on the western bank of the Lena river. The measurements were conducted during three campaigns: 3-24 June, 8-26 July, and 14-30 August, in the summer of 2009. A dynamic flow-through enclosure technique was applied for adsorbent sampling, and the samples were analysed offline with a gas chromatograph. Between 29 and 45 samples were taken from each shoot during all three campaigns. Seven different monoterpenes, six different sesquiterpenes, linalool isoprene, and 2-methyl-3-buten-2-ol (MBO) were identified. The monthly median value of the total terpenoid emissions varied between 0.006 and 10.6 μg gdw-1 h-1. The emissions were dominated by monoterpenes, which constituted between 61 and 92% of the total emissions. About half of the monoterpene emissions were comprised of Δ 3-carene; α- and β-pinene had significant emissions as well. Linalool emissions were also substantial, comprising 3-37% of the total emissions, especially in June. Sesquiterpenes accounted for less than 3% and isoprene less than 1% of the total emissions. Based on the measured emission rates, the relative atmospheric concentration of each compound was estimated. Monoterpenes were the species with the highest relative concentration, while linalool and sesquiterpenes had a notably smaller contribution to the estimated atmospheric concentration than to the emission rates. A temperature-dependent pool algorithm with a constant β (0.09 °C-1 for monoterpenes and 0.143 °C-1 for

  10. An East Siberian ice shelf during the Late Pleistocene glaciations: Numerical reconstructions

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    Colleoni, Florence; Kirchner, Nina; Niessen, Frank; Quiquet, Aurélien; Liakka, Johan

    2016-09-01

    A recent data campaign in the East Siberian Sea has revealed evidence of grounded and floating ice dynamics in regions of up to 1000 m water depth, and which are attributed to glaciations older than the Last Glacial Maximum (21 kyrs BP). The main hypothesis based on this evidence is that a small ice cap developed over Beringia and expanded over the East Siberian continental margin during some of the Late Pleistocene glaciations. Other similar evidence of ice dynamics that have been previously collected on the shallow continental shelves of the Arctic Ocean have been attributed to the penultimate glaciation, i.e. Marine Isotopes Stage 6 (≈140 kyrs BP). We use an ice sheet model, forced by two previously simulated MIS 6 glacial maximum climates, to carry out a series of sensitivity experiments testing the impact of dynamics and mass-balance related parameters on the geometry of the East Siberian ice cap and ice shelf. Results show that the ice cap developing over Beringia connects to the Eurasian ice sheet in all simulations and that its volume ranges between 6 and 14 m SLE, depending on the climate forcing. This ice cap generates an ice shelf of dimensions comparable with or larger than the present-day Ross ice shelf in West Antarctica. Although the ice shelf extent strongly depends on the ice flux through the grounding line, it is particularly sensitive to the choice of the calving and basal melting parameters. Finally, inhibiting a merging of the Beringia ice cap with the Eurasian ice sheet affects the expansion of the ice shelf only in the simulations where the ice cap fluxes are not large enough to compensate for the fluxes coming from the Eurasian ice sheet.

  11. Model simulations of the annual cycle of the landfast ice thickness in the East Siberian Sea

    Institute of Scientific and Technical Information of China (English)

    YANG Yu; Matti Leppranta; LI Zhijun; Bin Cheng; ZHAI Mengxi; Denis Demchev

    2015-01-01

    The annual cycle of the thickness and temperature of landfast sea ice in the East Siberian Sea has been examined using a one-dimensional thermodynamic model. The model was calibrated for the year August 2012–July 2013, forced using the data of the Russian weather station Kotel’ny Island and ECMWF reanalyses. Thermal growth and decay of ice were reproduced well, and the maximum annual ice thickness and breakup day became 1.64 m and the end of July. Oceanic heat lfux was 2 W.m–2 in winter and raised to 25 W.m–2 in summer, albedo was 0.3–0.8 depending on the surface type (snow/ice and wet/dry). The model outcome showed sensitivity to the albedo, air temperature and oceanic heat lfux. The modelled snow cover was less than 10 cm having a small inlfuence on the ice thickness. In situ sea ice thickness in the East Siberian Sea is rarely available in publications. This study provides a method for quantitative ice thickness estimation by modelling. The result can be used as a proxy to understand the sea ice conditions on the Eurasian Arctic coast, which is important for shipping and high-resolution Arctic climate modelling.

  12. Acidification of East Siberian Arctic Shelf waters through addition of freshwater and terrestrial carbon

    Science.gov (United States)

    Semiletov, Igor; Pipko, Irina; Gustafsson, Örjan; Anderson, Leif G.; Sergienko, Valentin; Pugach, Svetlana; Dudarev, Oleg; Charkin, Alexander; Gukov, Alexander; Bröder, Lisa; Andersson, August; Spivak, Eduard; Shakhova, Natalia

    2016-05-01

    Ocean acidification affects marine ecosystems and carbon cycling, and is considered a direct effect of anthropogenic carbon dioxide uptake from the atmosphere. Accumulation of atmospheric CO2 in ocean surface waters is predicted to make the ocean twice as acidic by the end of this century. The Arctic Ocean is particularly sensitive to ocean acidification because more CO2 can dissolve in cold water. Here we present observations of the chemical and physical characteristics of East Siberian Arctic Shelf waters from 1999, 2000-2005, 2008 and 2011, and find extreme aragonite undersaturation that reflects acidity levels in excess of those projected in this region for 2100. Dissolved inorganic carbon isotopic data and Markov chain Monte Carlo simulations of water sources using salinity and δ18O data suggest that the persistent acidification is driven by the degradation of terrestrial organic matter and discharge of Arctic river water with elevated CO2 concentrations, rather than by uptake of atmospheric CO2. We suggest that East Siberian Arctic Shelf waters may become more acidic if thawing permafrost leads to enhanced terrestrial organic carbon inputs and if freshwater additions continue to increase, which may affect their efficiency as a source of CO2.

  13. Deglacial sea level history of the East Siberian Sea and Chukchi Sea margins

    Science.gov (United States)

    Cronin, Thomas M.; O'Regan, Matt; Pearce, Christof; Gemery, Laura; Toomey, Michael; Semiletov, Igor; Jakobsson, Martin

    2017-09-01

    Deglacial (12.8-10.7 ka) sea level history on the East Siberian continental shelf and upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC1) and multicore SWERUS-L2-4-MC1 (4-MC1), and a gravity core from an East Siberian Sea transect, SWERUS-L2-20-GC1 (20-GC1). Cores 4-PC1 and 20-GC were taken at 120 and 115 m of modern water depth, respectively, only a few meters above the global last glacial maximum (LGM; ˜ 24 kiloannum or ka) minimum sea level of ˜ 125-130 meters below sea level (m b.s.l.). Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleodepths, the data reveal a dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1) followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal) period. A rapid relative sea level rise beginning at roughly 11.4 to 10.8 ka ( ˜ 400 cm of core depth) is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 m b.s.l. at the 4-PC1 site and 102 m b.s.l. at 20-GC1. Regional sea level near the end of the YD was up to 42-47 m lower than predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

  14. East Siberian Sea, an Arctic region of very high biogeochemical activity

    Directory of Open Access Journals (Sweden)

    L. G. Anderson

    2011-06-01

    Full Text Available Shelf seas are among the most active biogeochemical marine environments and the East Siberian Sea is a prime example. This sea is supplied by seawater from both the Atlantic and Pacific Oceans and has a substantial input of river runoff. All of these waters contribute chemical constituents, dissolved and particulate, but of different signatures. Sea ice formation during the winter season and melting in the summer has a major impact on physical as well as biogeochemical conditions. The internal circulation and water mass distribution is significantly influenced by the atmospheric pressure field. The western region is dominated by input of river runoff from the Laptev Sea and an extensive input of terrestrial organic matter. The microbial decay of this organic matter produces carbon dioxide (CO2 that oversaturates all waters from the surface to bottom relative to atmospheric level, even when primary production, inferred from low surface water nutrients, has occurred. The eastern surface waters were under-saturated with respect to CO2 illustrating the dominance of marine primary production. The drawdown of dissolved inorganic carbon equals a primary production of ~0.8 ± 2 mol C m−2, which when multiplied by half the area of the East Siberian Sea, ~500 000 km2, results in an annual primary production of 0.4 (± 1 × 1012 mol C or ~4 (± 10 × 1012 gC. Microbial decay occurs through much of the water column, but dominates at the sediment interface where the majority of organic matter ends up, thus more of the decay products are recycled to the bottom water. High nutrient concentrations and fugacity of CO2 and low oxygen and pH were observed in the bottom waters. Another signature of organic matter decomposition, methane (CH4, was observed in very high but variable concentrations. This is due to its seabed sources of glacial origin or modern production from

  15. Atmospheric constraints on the methane emissions from the East Siberian Shelf

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    A. Berchet

    2015-09-01

    Full Text Available Sub-sea permafrost and hydrates in the East Siberian Arctic Ocean Continental Shelf (ESAS constitute a substantial carbon pool, and a potentially large source of methane to the atmosphere. Previous studies based on interpolated oceanographic campaigns estimated atmospheric emissions from this area at 8–17 Tg CH4 y−1. Here, we propose insights based on atmospheric observations to evaluate these estimates. Isotopic observations suggest a biogenic origin (either terrestrial or marine of the methane in air masses originating from ESAS during summer 2010. The comparison of high-resolution simulations of atmospheric methane mole fractions to continuous methane observations during the entire year 2012 confirms the high variability and heterogeneity of the methane releases from ESAS. Simulated mole fractions including a 8 Tg CH4 y−1 source from ESAS are found largely overestimated compared to the observations in winter, whereas summer signals are more consistent with each other. Based on a comprehensive statistical analysis of the observations and of the simulations, annual methane emissions from ESAS are estimated in a range of 0.5–4.3 Tg CH4 y−1.

  16. Spatial distribution of methane seepage on the East Siberian Arctic Shelf

    Science.gov (United States)

    Stubbs, C.; Leifer, I.; Shakhova, N. E.; Semiletov, I. P.; Luyendyk, B. P.

    2010-12-01

    A 2009 multibeam sonar survey of the shallow water-column (mean depth 10 m), near-coastal region of the East Siberian Arctic Shelf (ESAS) adjacent to the Lena River Delta detected tens of thousands of widespread bubble plume seeps. The ESAS contains an estimated 1400 GT (109 tons = 1 GT) of carbon sequestered within and beneath a sub-sea permafrost unit that has become inundated due to sea-level transgression over the last ~15,000 years. This carbon pool includes methane (CH4) as free and dissolved gas, as well as potentially extensive methane hydrate deposits, yet its contribution to global carbon stocks has traditionally been ignored due to the assumed integrity of the sub-sea permafrost as an impermeable barrier to hydrocarbon migration. Recent results indicate that in some regions of the ESAS, methane is migrating through destabilized permafrost into the shallow water-column from which it efficiently vents to the atmosphere. This process represents an unknown but potentially significant contribution to the global greenhouse gas budget and is likely to accelerate under global warming scenarios. We hypothesize that the mapped seeps are fed by methane deposits within and beneath capping permafrost units that release gas into the thin overlying sediments through columns of thaw sediments and other permeable structures within the permafrost. Such sub-sea permafrost features have been previously identified in association with isolated bubble plumes in the ESAS as close as 25 km from the study area (Rekant et al., 2009). These proposed migration pathways suggest thermal destabilization within the subsea permafrost cap; however, the rates at which these processes are occurring remain unknown. The spatial distributions of the most numerous and intense areas of seepage correlate with the areas of greatest fluvial discharge from the Lena and Olenek Rivers and their tributaries. This thermal influence is also evident in seasonal time series of adjacent sea ice retreat over

  17. Sources, degradation and transport of terrigenous organic carbon on the East Siberian Arctic Shelf Seas

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    Tesi, Tommaso; Semiletov, Igor; Dudarev, Oleg; Gustafsson, Örjan

    2013-04-01

    Recent studies suggest that the present hydrological regime increase observed in the Arctic rivers is mainly the consequence of the changes in permafrost conditions as a result of climate warming. Given the enormous amount of carbon stored in coastal and terrestrial permafrost the potentially increased supply from this large carbon pool to the coastal Arctic Ocean, possibly associated with a translocated release to the atmosphere as CO2, is considered a plausible scenario in a warming climate. However, there is not sufficient information regarding the reactivity of terrigenous material once supplied to the Arctic Ocean. In this study, we address this critical issue by examining the organic composition of surface sediments collected over extensive scales on the East Siberian Arctic Shelf (ESAS) as part of the International Siberian Shelf Study (ISSS). The ESAS represents by far the largest shelf of the Arctic Ocean. Samples were collected from the inner- to the outer-shelf following the sediment transport pathway in a region between the Lena and the Kolyma rivers. The analytical approach includes the characterization of marine and land-derived carbon using a large number of molecular biomarkers obtained by alkaline CuO oxidation such as lignin-phenols, cutin-derived products, p-hydroxy benzenes, benzoic acids, fatty acids, and dicarboxylic acids. Our results indicated high concentrations of terrigenous material in shallow sediments and a marked decrease of terrestrial biomarkers with increasing distance from the coastline. In parallel, lignin-based degradation proxies suggested highly altered terrigenous carbon in mid- and outer-shelf sediments compared to coastal sediments. Furthermore, the ratio of cutin-derived products over lignin significantly increased along the sediment transport pathway. Considering that cutin is considered to be intrinsically more reactive compared to lignin, high values of this ratio off the coastal region were interpreted as selective

  18. East Siberian Sea, an arctic region of very high biogeochemical activity

    Directory of Open Access Journals (Sweden)

    L. G. Anderson

    2011-02-01

    Full Text Available Shelf seas are among the most active biogeochemical marine environments and the East Siberian Sea is a prime example. This sea is supplied by seawater from both the Atlantic and Pacific Oceans and has a substantial input of river runoff. All of these waters contribute chemical constituents, dissolved and particulate, but of different signatures. Sea ice formation during the winter season and melting in the summer has a major impact on physical as well as biochemical conditions. The internal circulation and water mass distribution is significantly influenced by the atmospheric pressure field. The western region is dominated by input of river runoff from the Laptev Sea and an extensive input of terrestrial organic matter. The microbial decay of this organic matter produces carbon dioxide (CO2 over-saturating all waters from the surface to the bottom relative to atmospheric values, even if the nutrient concentrations of the surface waters showed recent primary production. The eastern surface waters were under-saturated with respect to CO2 illustrating the dominance of marine primary production. The drawdown of dissolved inorganic carbon equals a primary production of ∼1 mol C m−2, which when multiplied by half the area of the East Siberian Sea, 500 000 km2, results in an annual primary production of 0.5×1012 mol C or 6×1012 gC. Even though microbial decay occurs through much of the water column it dominates at the sediment surface where the majority of organic matter ends up, and most of the decay products are added to the bottom water. High nutrient concentrations and fugacity of CO2 and low oxygen and pH were observed in the bottom waters. Another signature of organic matter decomposition, methane (CH4, was observed in very high but variable concentrations. This is due to its seabed sources of glacial origin or modern production from ancient organic

  19. Export of calcium carbonate corrosive waters from the East Siberian Sea

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    Anderson, Leif G.; Ek, Jörgen; Ericson, Ylva; Humborg, Christoph; Semiletov, Igor; Sundbom, Marcus; Ulfsbo, Adam

    2017-04-01

    The Siberian shelf seas are areas of extensive biogeochemical transformation of organic matter, both of marine and terrestrial origin. This in combination with brine production from sea ice formation results in a cold bottom water of relative high salinity and partial pressure of carbon dioxide (pCO2). Data from the SWERUS-C3 expedition compiled on the icebreaker Oden in July to September 2014 show the distribution of such waters at the outer shelf, as well as their export into the deep central Arctic basins. Very high pCO2 water, up to ˜ 1000 µatm, was observed associated with high nutrients and low oxygen concentrations. Consequently, this water had low saturation state with respect to calcium carbonate down to less than 0.8 for calcite and 0.5 for aragonite. Waters undersaturated in aragonite were also observed in the surface in waters at equilibrium with atmospheric CO2; however, at these conditions the cause of under-saturation was low salinity from river runoff and/or sea ice melt. The calcium carbonate corrosive water was observed all along the continental margin and well out into the deep Makarov and Canada basins at a depth from about 50 m depth in the west to about 150 m in the east. These waters of low aragonite saturation state are traced in historic data to the Canada Basin and in the waters flowing out of the Arctic Ocean north of Greenland and in the western Fram Strait, thus potentially impacting the marine life in the North Atlantic Ocean.

  20. Source, transport and fate of soil organic matter inferred from microbial biomarker lipids on the East Siberian Arctic Shelf

    Science.gov (United States)

    Bischoff, Juliane; Sparkes, Robert B.; Doğrul Selver, Ayça; Spencer, Robert G. M.; Gustafsson, Örjan; Semiletov, Igor P.; Dudarev, Oleg V.; Wagner, Dirk; Rivkina, Elizaveta; van Dongen, Bart E.; Talbot, Helen M.

    2016-09-01

    The Siberian Arctic contains a globally significant pool of organic carbon (OC) vulnerable to enhanced warming and subsequent release by both fluvial and coastal erosion processes. However, the rate of release, its behaviour in the Arctic Ocean and vulnerability to remineralisation is poorly understood. Here we combine new measurements of microbial biohopanoids including adenosylhopane, a lipid associated with soil microbial communities, with published glycerol dialkyl glycerol tetraethers (GDGTs) and bulk δ13C measurements to improve knowledge of the fate of OC transported to the East Siberian Arctic Shelf (ESAS). The microbial hopanoid-based soil OC proxy R'soil ranges from 0.0 to 0.8 across the ESAS, with highest values nearshore and decreases offshore. Across the shelf R'soil displays a negative linear correlation with bulk δ13C measurements (r2 = -0.73, p = balance between delivery and removal of OC from different sources. The good correlation between the hopanoid and bulk terrestrial signal suggests a broad range of hopanoid sources, both fluvial and via coastal erosion, whilst GDGTs appear to be primarily sourced via fluvial transport. Analysis of ice complex deposits (ICDs) revealed an average R'soil of 0.5 for the Lena Delta, equivalent to that of the Buor-Khaya Bay sediments, whilst ICDs from further east showed higher values (0.6-0.85). Although R'soil correlates more closely with bulk OC than the BIT, our understanding of the endmembers of this system is clearly still incomplete, with variations between the different East Siberian Arctic regions potentially reflecting differences in environmental conditions (e.g. temperature, pH), but other physiological controls on microbial bacteriohopanepolyol (BHP) production under psychrophilic conditions are as yet unknown.

  1. Assessment of Undiscovered Petroleum Resources of the North and East Margins of the Siberian Craton, Russian Federation

    Science.gov (United States)

    Klett, T.R.

    2008-01-01

    Four geologic provinces located along the north and east margins of the Siberian craton were assessed for undiscovered crude oil, natural gas, and natural gas liquids/condensates resources as part of the U.S. Geological Survey's (USGS) Circum-Arctic Oil and Gas Resource Appraisal. Using a geology-based methodology, the USGS estimated the mean undiscovered, conventional petroleum resources in these provinces to be approximately 28 billion barrels of oil equivalent, including approximately 8 billion barrels of crude oil, 106 trillion cubic feet of natural gas, and 3 billion barrels of natural gas liquids.

  2. Macromolecular composition of terrestrial and marine organic matter in sediments across the East Siberian Arctic Shelf

    Science.gov (United States)

    Sparkes, Robert B.; Doğrul Selver, Ayça; Gustafsson, Örjan; Semiletov, Igor P.; Haghipour, Negar; Wacker, Lukas; Eglinton, Timothy I.; Talbot, Helen M.; van Dongen, Bart E.

    2016-10-01

    Mobilisation of terrestrial organic carbon (terrOC) from permafrost environments in eastern Siberia has the potential to deliver significant amounts of carbon to the Arctic Ocean, via both fluvial and coastal erosion. Eroded terrOC can be degraded during offshore transport or deposited across the wide East Siberian Arctic Shelf (ESAS). Most studies of terrOC on the ESAS have concentrated on solvent-extractable organic matter, but this represents only a small proportion of the total terrOC load. In this study we have used pyrolysis-gas chromatography-mass spectrometry (py-GCMS) to study all major groups of macromolecular components of the terrOC; this is the first time that this technique has been applied to the ESAS. This has shown that there is a strong offshore trend from terrestrial phenols, aromatics and cyclopentenones to marine pyridines. There is good agreement between proportion phenols measured using py-GCMS and independent quantification of lignin phenol concentrations (r2 = 0.67, p < 0.01, n = 24). Furfurals, thought to represent carbohydrates, show no offshore trend and are likely found in both marine and terrestrial organic matter. We have also collected new radiocarbon data for bulk OC (14COC) which, when coupled with previous measurements, allows us to produce the most comprehensive 14COC map of the ESAS to date. Combining the 14COC and py-GCMS data suggests that the aromatics group of compounds is likely sourced from old, aged terrOC, in contrast to the phenols group, which is likely sourced from modern woody material. We propose that an index of the relative proportions of phenols and pyridines can be used as a novel terrestrial vs. marine proxy measurement for macromolecular organic matter. Principal component analysis found that various terrestrial vs. marine proxies show different patterns across the ESAS, and it shows that multiple river-ocean transects of surface sediments transition from river-dominated to coastal-erosion-dominated to marine

  3. Pore water geochemistry along continental slopes north of the East Siberian Sea: inference of low methane concentrations

    Science.gov (United States)

    Miller, Clint M.; Dickens, Gerald R.; Jakobsson, Martin; Johansson, Carina; Koshurnikov, Andrey; O'Regan, Matt; Muschitiello, Francesco; Stranne, Christian; Mörth, Carl-Magnus

    2017-06-01

    Continental slopes north of the East Siberian Sea potentially hold large amounts of methane (CH4) in sediments as gas hydrate and free gas. Although release of this CH4 to the ocean and atmosphere has become a topic of discussion, the region remains sparingly explored. Here we present pore water chemistry results from 32 sediment cores taken during Leg 2 of the 2014 joint Swedish-Russian-US Arctic Ocean Investigation of Climate-Cryosphere-Carbon Interactions (SWERUS-C3) expedition. The cores come from depth transects across the slope and rise extending between the Mendeleev and the Lomonosov ridges, north of Wrangel Island and the New Siberian Islands, respectively. Upward CH4 flux towards the seafloor, as inferred from profiles of dissolved sulfate (SO42-), alkalinity, and the δ13C of dissolved inorganic carbon (DIC), is negligible at all stations east of 143° E longitude. In the upper 8 m of these cores, downward SO42- flux never exceeds 6.2 mol m-2 kyr-1, the upward alkalinity flux never exceeds 6.8 mol m-2 kyr-1, and δ13C composition of DIC (δ13C-DIC) only moderately decreases with depth (-3.6 ‰ m-1 on average). Moreover, upon addition of Zn acetate to pore water samples, ZnS did not precipitate, indicating a lack of dissolved H2S. Phosphate, ammonium, and metal profiles reveal that metal oxide reduction by organic carbon dominates the geochemical environment and supports very low organic carbon turnover rates. A single core on the Lomonosov Ridge differs, as diffusive fluxes for SO42- and alkalinity were 13.9 and 11.3 mol m-2 kyr-1, respectively, the δ13C-DIC gradient was 5.6 ‰ m-1, and Mn2+ reduction terminated within 1.3 m of the seafloor. These are among the first pore water results generated from this vast climatically sensitive region, and they imply that abundant CH4, including gas hydrates, do not characterize the East Siberian Sea slope or rise along the investigated depth transects. This contradicts previous modeling and discussions, which

  4. Can we explain vagrancy in Europe with the autumn migration phenology of Siberian warbler species in East Russia?

    Directory of Open Access Journals (Sweden)

    Bozó László

    2016-06-01

    Full Text Available We examined the autumn migration phenology of nine Siberian breeding songbirds: Thick-billed Warbler (Iduna aedon, Black-browed Reed Warbler (Acrocephalus bistrigiceps, Pallas’s Grasshopper Warbler (Locustella certhiola, Lanceolated Warbler (L. lanceolata, Yellow-browed Warbler (Phylloscopus inornatus, Arctic Warbler (Ph. borealis, Dusky Warbler (Ph. fuscatus, Radde’s Warbler (Ph. schwarzi, Two-barred Warbler (Ph. plumbeitarsus and compared the migration dynamic characteristics with their European occurrence time. The study was carried out within the Amur Bird Project in the Russian Far East along the river Amur at Muraviovka Park between 2011 and 2014. The birds were caught with mistnets and ringed with individually numbered rings. For the characterization of the migration, we used timing, the intervals and the peaks of the migration, the percentage of the recaptures and the average time between the first and the last captures. The timing of migration in the studied species differed in the timing, the intervals (30-67 days and the migration peaks (14 August - 17 September.

  5. Chapter 27: Geology and petroleum potential of the north and east margins of the Siberian Craton, north of the Arctic Circle

    Science.gov (United States)

    Klett, T.R.; Wandrey, C.J.; Pitman, J.K.

    2011-01-01

    The Siberian Craton consists of crystalline rocks and superimposed Precambrian sedimentary rocks deposited in rift basins. Palaeozoic rocks, mainly carbonates, were deposited along the margins of the craton to form an outwardly younger concentric pattern that underlies an outward-thickening Mesozoic sedimentary section. The north and east margins of the Siberian Craton subsequently became foreland basins created by compressional deformation during collision with other tectonic plates. The Tunguska Basin developed as a Palaeozoic rift/sag basin over Proterozoic rifts. The geological provinces along the north and east margins of the Siberian Craton are immature with respect to exploration, so exploration-history analysis alone cannot be used for assessing undiscovered petroleum resources. Therefore, other areas from around the world having greater petroleum exploration maturity and similar geological characteristics, and which have been previously assessed, were used as analogues to aid in this assessment. The analogues included those of foreland basins and rift/sag basins that were later subjected to compression. The US Geological Survey estimated the mean undiscovered, technically recoverable conventional petroleum resources to be approximately 28 billion barrels of oil equivalent, including approximately 8 billion barrels of crude oil, 103 trillion cubic feet of natural gas and 3 billion barrels of natural gas liquids. ?? 2011 The Geological Society of London.

  6. Ice Complex permafrost of MIS5 age in the Dmitry Laptev Strait coastal region (East Siberian Arctic)

    Science.gov (United States)

    Wetterich, Sebastian; Tumskoy, Vladimir; Rudaya, Natalia; Kuznetsov, Vladislav; Maksimov, Fedor; Opel, Thomas; Meyer, Hanno; Andreev, Andrei A.; Schirrmeister, Lutz

    2016-09-01

    Ice Complex deposits (locally known as the Buchchagy Ice Complex) are exposed at both coasts of the East Siberian Dmitry Laptev Strait and preserved below the Yedoma Ice Complex that formed during MIS3 and MIS2 (Marine Isotope Stage) and lateglacial-Holocene thermokarst deposits (MIS1). Radioisotope disequilibria (230Th/U) of peaty horizons date the Buchchagy Ice Complex deposition to 126 + 16/-13 kyr and 117 + 19/-14 kyr until 98 ± 5 kyr and 89 ± 5 kyr. The deposit is characterised by poorly-sorted medium-to-coarse silts with cryogenic structures of horizontal ice bands, lens-like, and lens-like reticulated segregation ice. Two peaty horizons within the Buchchagy Ice Complex and syngenetic ice wedges (2-4 m wide, up to 10 m high) are striking. The isotopic composition (δ18O, δD) of Buchchagy ice-wedge ice indicates winter conditions colder than during the MIS3 interstadial and warmer than during MIS2 stadial, and similar atmospheric winter moisture sources as during the MIS2 stadial. Buchchagy Ice Complex pollen spectra reveal tundra-steppe vegetation and harsher summer conditions than during the MIS3 interstadial and rather similar vegetation as during the MIS2 stadial. Short-term climatic variability during MIS5 is reflected in the record. Even though the regional chronostratigraphic relationship of the Buchchagy Ice Complex to the Last Interglacial remains unclear because numerical dating is widely lacking, the present study indicates permafrost (Ice Complex) formation during MIS5 sensu lato, and its preservation afterwards. Palaeoenvironmental insights into past climate and the periglacial landscape dynamics of arctic lowlands in eastern Siberia are deduced from the record.

  7. Fate of organic matter released from permafrost to the East Siberian Arctic Shelf: burial vs lateral transport

    Science.gov (United States)

    Bröder, Lisa; Tesi, Tommaso; Dudarev, Oleg; Semiletov, Igor; Gustafsson, Örjan

    2015-04-01

    Ongoing global warming may trigger the remobilization of old terrigenous organic carbon (TerrOC) pools into the modern carbon cycle, which could then provide a potential positive feedback for global warming. A better understanding of the fate of such material, released from thawing permafrost via rivers and coastal erosion into the Arctic shelves seas, is therefore crucial for anticipating its influence on putative carbon-climate couplings. The main goal of this study is therefore to explore how sources and degradation status of TerrOC on the East Siberian Arctic Shelf (ESAS) vary both spatially and over time. To compare processes occurring during the cross-shelf transport and after burial we analyzed a suite of well-known terrestrial and marine biomarkers as well as source-diagnostic bulk carbon isotopes (δ13C, Δ14C) in sediments from the vast ESAS. Sediments were collected at increasing distances from the main river outlets (Kolyma and Lena rivers) while sediment cores encompassed over a century of accumulation. Our results show that TerrOC concentrations vary noticeably more during cross-shelf transport than during burial in sediments. The concentrations of lignin phenols and cutin acids (tracers of vascular plants) do not display clear changes down-core, whereas they decrease over one order of magnitude along the transect. From the molecular-based degradation proxies for TerrOC (CPI of HMW lipids, the HMW acids/alkanes ratio and the acid/aldehyde ratio of lignin phenols) no clear picture arises for down-core changes. With increasing distance from the coast there appears to be a trend to more degraded TerrOC. Furthermore, across the shelf bulk parameters indicate growing relative importance of marine organic matter at the expense of TerrOC. Strongly decreasing marine biomarker concentrations over time confirm the lability of this fresh marine material towards degradation. Overall, we infer that two different key processes affect the TerrOC cycling on this

  8. The Origin(s) of the Methane Excess in the Shallow East Siberian Arctic Shelf Unraveled with Triple Isotope Analysis

    Science.gov (United States)

    Sapart, C. J.; Shakhova, N. E.; Semiletov, I. P.; Jansen, J.; Kosmach, D.; Dudarev, O.; Szidat, S.; van der Veen, C.; Sergienko, V.; Salyuk, A.; Tumskoy, V.; Tison, J. L.; Egger, M.; Röckmann, T.

    2015-12-01

    Methane (CH4) is a strong greenhouse gas emitted by both human activity and natural processes. Its emissions from vast marine and terrestrial carbon pools in Arctic shallow reservoirs could create a strong positive feedback to climate change as permafrost is thawing. The East Siberian Arctic Shelf (ESAS) overlays large areas of subsea permafrost that is degrading and causing the release of large amount of CH4 originally stored or formed there towards the water column. Large scale CH4 super-saturation has been observed in the ESAS waters, pointing out to leakages of CH4 through the sea floor and possibly to the atmosphere but the origin(s) of this gas is still debated. Here we present CH4 concentration and isotope data analyzed on gas extracted from sediment and water sampled over the shallow ESAS from 2007-2013. We find the presence of large amount (up to 500μM) of CH4 within the partially thawed subsea permafrost of this region. For all sediment cores, both hydrogen and carbon CH4 isotope data show the presence of highly depleted (in comparison with the atmospheric CH4 isotope signature) CH4, indicative of a microbial origin. Radiocarbon data demonstrates that in most cases the CH4 present in the ESAS sediment is of Pleistocene age or older. These results reveal the presence of CH4 that is not from thermogenic/natural gas (isotopically enriched CH4) origin as it has long been thought, but the results of microbial CH4 formation using as primary substrate old organic matter in the deep subsea permafrost or below. Our observations show that this CH4 accumulates under the Holocene marine sediment layer (when present) and slowly diffuses towards the sediment surface where it undergoes anaerobic methane oxidation. However, at locations where deep and/or open taliks develop in subsea permafrost, CH4 escapes to the water column as bubble plumes. In that case ebullition processes prevent CH4 anaerobic oxidation to occur in the surface sediment. CH4 will thus migrate

  9. Decadal changes in carbon fluxes at the East Siberian continental margin: interactions of ice cover, ocean productivity, particle sedimentation and benthic life

    Science.gov (United States)

    Boetius, A.; Bienhold, C.; Felden, J.; Fernandez Mendez, M.; Gusky, M.; Rossel, P. E.; Vedenin, A.; Wenzhoefer, F.

    2015-12-01

    The observed and predicted Climate-Carbon-Cryosphere interactions in the Arctic Ocean are likely to alter productivity and carbon fluxes of the Siberian continental margin and adjacent basins. Here, we compare field observations and samples obtained in the nineties, and recently in 2012 during the sea ice minimum, to assess decadal changes in the productivity, export and recycling of organic matter at the outer East Siberian margin. In the 90s, the Laptev Sea margin was still largely ice-covered throughout the year, and the samples and measurements obtained represent an ecological baseline against which current and future ecosystem shifts can be assessed. The POLARSTERN expedition IceArc (ARK-XXVII/3) returned in September 2012 to resample the same transects between 60 and 3400 m water depth as well as stations in the adjacent deep basins. Our results suggest that environmental changes in the past two decades, foremost sea ice thinning and retreat, have led to a substantial increase in phytodetritus sedimentation to the seafloor, especially at the lower margin and adjacent basins. This is reflected in increased benthic microbial activities, leading to higher carbon remineralization rates, especially deeper than 3000 m. Besides a relative increase in typical particle degrading bacterial types in surface sediments, bacterial community composition showed little variation between the two years, suggesting that local microbial communities can cope with changing food input. First assessments of faunal abundances suggest an increase in polychaetes,holothurians and bivalves at depth, which fits the prediction of higher productivity and particle deposition rates upon sea ice retreat. The presentation also discusses the controversial issue whether there is evidence for an Arctic-wide increase in carbon flux, or whether we are looking at a spatial shift of the productive marginal ice zone as the main factor to enhance carbon flux to the deep Siberian margin.

  10. Contrasting composition of terrigenous organic matter in the dissolved, particulate and sedimentary organic carbon pools on the outer East Siberian Arctic Shelf

    Science.gov (United States)

    Salvadó, Joan A.; Tesi, Tommaso; Sundbom, Marcus; Karlsson, Emma; Kruså, Martin; Semiletov, Igor P.; Panova, Elena; Gustafsson, Örjan

    2016-11-01

    Fluvial discharge and coastal erosion of the permafrost-dominated East Siberian Arctic delivers large quantities of terrigenous organic carbon (Terr-OC) to marine waters. The composition and fate of the remobilized Terr-OC needs to be better constrained as it impacts the potential for a climate-carbon feedback. In the present study, the bulk isotope (δ13C and Δ14C) and macromolecular (lignin-derived phenols) composition of the cross-shelf exported organic carbon (OC) in different marine pools is evaluated. For this purpose, as part of the SWERUS-C3 expedition (July-September 2014), sediment organic carbon (SOC) as well as water column (from surface and near-bottom seawater) dissolved organic carbon (DOC) and particulate organic carbon (POC) samples were collected along the outer shelves of the Kara Sea, Laptev Sea and East Siberian Sea. The results show that the Lena River and the DOC may have a preferential role in the transport of Terr-OC to the outer shelf. DOC concentrations (740-3600 µg L-1) were 1 order of magnitude higher than POC (20-360 µg L-1), with higher concentrations towards the Lena River plume. The δ13C signatures in the three carbon pools varied from -23.9 ± 1.9 ‰ in the SOC, -26.1 ± 1.2 ‰ in the DOC and -27.1 ± 1.9 ‰ in the POC. The Δ14C values ranged between -395 ± 83 (SOC), -226 ± 92 (DOC) and -113 ± 122 ‰ (POC). These stable and radiocarbon isotopes were also different between the Laptev Sea and the East Siberian Sea. Both DOC and POC showed a depleted and younger trend off the Lena River plume. Further, the Pacific inflow and the sea-ice coverage, which works as a barrier preventing the input of "young" DOC and POC, seem to have a strong influence in these carbon pools, presenting older and more enriched δ13C signatures under the sea-ice extent. Lignin phenols exhibited higher OC-normalized concentrations in the SOC (0.10-2.34 mg g-1 OC) and DOC (0.08-2.40 mg g-1 OC) than in the POC (0.03-1.14 mg g-1 OC). The good

  11. On the connection among components of carbon cycling and water mass parameters in the East Siberian Arctic Shelf: The First Quantitative Assessment.

    Science.gov (United States)

    Semiletov, Igor; Shakhova, Natalia; Pugach, Svetlana; Pipko, Irina; Dudarev, Oleg

    2010-05-01

    The East Siberian Arctic Shelf (ESAS), the widest and shallowest ocean shelf in the world, is an important region for producing and processing organic matter before the material is transported into the Arctic Ocean. Up to 100% of the total organic carbon (TOC) in the ESAS surface sediments is terrestrial by origin (TOCterr). TOCterr flux in the ESAS integrates riverine and coastal erosion signals, transforming TOCterr to carbon dioxide and other components within the land-shelf-atmosphere system. Degradation of eroded organic carbon produces a decrease in values of pH (causing ocean acidification) and dissolved oxygen, while producing an increase in the partial pressure of carbon dioxide (pCO2), total CO2 (TCO2), and nutrients (Semiletov, 1999; Semiletov et al., 2007; Anderson et al., 2009). Ongoing warming causes thawing of the permafrost underlying a majority of arctic river watersheds and more than 80% of the ESAS area; this process could accelerate river discharge, carbon losses from soils, involvement of old carbon in the modern carbon cycle, and the mobilization of previously-originated methane (CH4) that is currently stored within seabed deposits (Shakhova and Semiletov, 2009). Given current and predicted dramatic Arctic climate changes, baseline measurements are critical to elucidating Arctic carbon cycle feedback processes, predicting climate response, and understanding the likely ecological changes in the oligotrophic ESAS under future warmer (ice-free) climate scenarios. Here we present the first quantitative assessment of the connection among the components of carbon cycling and water mass parameters in the ESAS. Our results are based on a complex biogeochemical study performed by our group during 1997-2007. A strong regional correlation (~0.96) was found between the dissolved organic carbon (DOC) concentration and colored dissolved organic matter (CDOM) fluorescence measured in situ using the WETStar fluorometer, and between the "filtered" particulate

  12. 40Ar/39Ar dates from the West Siberian Basin: Siberian flood basalt province doubled.

    Science.gov (United States)

    Reichow, Marc K; Saunders, Andrew D; White, Rosalind V; Pringle, Malcolm S; Al'Mukhamedov, Alexander I; Medvedev, Alexander I; Kirda, Nikolay P

    2002-06-07

    Widespread basaltic volcanism occurred in the region of the West Siberian Basin in central Russia during Permo-Triassic times. New 40Ar/39Ar age determinations on plagioclase grains from deep boreholes in the basin reveal that the basalts were erupted 249.4 +/- 0.5 million years ago. This is synchronous with the bulk of the Siberian Traps, erupted further east on the Siberian Platform. The age and geochemical data confirm that the West Siberian Basin basalts are part of the Siberian Traps and at least double the confirmed area of the volcanic province as a whole. The larger area of volcanism strengthens the link between the volcanism and the end-Permian mass extinction.

  13. Decadal to millennial-scale variability in sea ice, primary productivity, and Pacific-Water inflow in the Chukchi/East Siberian Sea area (Arctic Ocean)

    Science.gov (United States)

    Stein, Ruediger; Fahl, Kirsten; Matthiessen, Jens; Méheust, Marie; Nam, Seung-il; Niessen, Frank; Schade, Inka; Schreck, Michael; Wassmuth, Saskia; Xiao, Xiaotong

    2014-05-01

    Sea-ice is an essential component of the global climate system and, especially, the Polar Oceans. An alarming decrease in term of sea-ice concentration, thickness and duration, has been observed in the Arctic Ocean and its marginal seas over the last 30 years. Thus, understanding the processes controlling modern sea-ice variability and reconstructing paleo-sea-ice extent and variability in polar regions have become of great interest for the international scientific community during the last years. Here, we present new proxy records determined in sediment cores from the East Siberian Sea (RV Polarstern Expedition ARK-XXIII/3 in 2008; Core PS72/350) and from the Chukchi Sea (RV Araon Expedition ARA2B in 2011; Core ARA2B-1A, -1B). These records, including organic-geochemical bulk parameters, specific biomarkers (IP25 and sterols; PIP25; for recent reviews see Stein et al., 2012; Belt and Müller, 2013), biogenic opal, mineralogical data as well as high-resolution XRF scanning data, give new insight into the short-term (decadal-, centennial- to millennial-scale) variability in sea-ice, primary productivity and Pacific-Water inflow during Holocene times. Maximum concentrations of phytoplankton biomarkers and biogenic opal were determined between 8.5 and 4 kyrs. BP, suggesting enhanced primary productivity triggered by increased inflow of nutrient-rich Pacific Water (and/or an increased nutrient input due to an ice-edge position). Short-lived peak values in productivity might be related to strong pulses of Pacific-Water input during this time period (cf., Ortiz et al., 2009). A seasonal sea-ice cover was present in the Chukchi Sea throughout the last 10 kyrs. During the last 3-4 kyrs. BP, the sea-ice cover significantly extended. References Belt, S.T. and Müller, J., 2013. The Arctic sea ice biomarker IP25: a review of current understanding, recommendations for future research and applications in palaeo sea ice reconstructions. Quaternary Science Review 73, 9-25. Ortiz

  14. Methane release from the East Siberian Arctic Shelf: The role of subsea permafrost and other controlling factors as inferred from decadal observational and modeling efforts

    Science.gov (United States)

    Shakhova, N. E.

    2015-12-01

    Sustained methane (CH4) release from thawing Arctic permafrost to atmosphere may be a positive, major feedback to climate warming. East Siberian Arctic Shelf (ESAS) atmospheric CH4 venting was reported as on par with flux from Arctic tundra. Unlike release when ancient carbon in thawed on-land permafrost is mobilized, ESAS CH4 release is not determined by modern methanogenesis. Pre-formed CH4 largely stems from seabed deposits. Our investigation, including observational studies using hydrological, biogeochemical, geophysical, geo-electrical, microbiological, and isotopic methods, and modeling efforts to assess current subsea permafrost state and the ESAS' contribution to the regional CH4 budget, have clarified processes driving ESAS CH4 emissions. Subsea permafrost state is a major emission determinant; rates vary by 3-5 orders of magnitude. Outer ESAS CH4 emission rates, where subsea permafrost is predicted to be degraded due to long submergence by seawater, in places are similar to near-shore rates, where deep/open taliks can form due to combined heating effects of seawater, river runoff, geothermal flux, and pre-existing thermokarst. Progressive subsea permafrost thawing and decreasing ice extent could significantly increase ESAS CH4 emissions. Subsea permafrost drilling results reveal modern recently submerged subsea permafrost degradation rates, contradicting previous hypotheses that thousands of years required to form escape paths for permafrost-preserved gas. We used a decadal observational ESAS water column and atmospheric boundary layer (ABL) data set to define the minimum source strength required to explain observed seasonally-increased ABL CH4 concentration. Modeling results agree with estimates from in-situ sonar data. In <10 m shallow water ≤72% of CH4 remains in surfacing bubbles. Dissolved CH4 fate largely depends on 3 factors: dissolved CH4 water column turnover time, water column stability against vertical mixing, and turbulent diffusion and

  15. Observing Muostakh Island disappear: erosion of a ground-ice-rich coast in response to summer warming and sea ice reduction on the East Siberian shelf

    Directory of Open Access Journals (Sweden)

    F. Günther

    2013-08-01

    observations made for various permafrost coastlines different from East Siberian Ice Complex coasts elsewhere in the Arctic. Seasonality and recent interannual variations of coastline retreat rates suggest that the combination of macro ground ice distribution in the ground and changes in enviromental forcing generate a cyclicity in coastal thermo-erosion, that is currently increasing in frequency.

  16. Siberian Pine Decline and Mortality in Southern Siberian Mountains

    Science.gov (United States)

    Kharuk, V. I.; Im, S. T.; Oskorbin, P. A.; Petrov, I. A.; Ranson, K. J.

    2013-01-01

    The causes and resulting spatial patterns of Siberian pine mortality in eastern Kuznetzky Alatau Mountains, Siberia were analyzed based on satellite (Landsat, MODIS) and dendrochronology data. Climate variables studied included temperature, precipitation and Standardized Precipitation-Evapotranspiration Index (SPEI) drought index. Landsat data analysis showed that stand mortality was first detected in the year 2006 at an elevation of 650 m, and extended up to 900 m by the year 2012. Mortality was accompanied by a decrease in MODIS derived vegetation index (EVI).. The area of dead stands and the upper mortality line were correlated with increased drought. The uphill margin of mortality was limited by elevational precipitation gradients. Dead stands (i.e., >75% tree mortality) were located mainly on southern slopes. With respect to slope, mortality was observed within a 7 deg - 20 deg range with greatest mortality occurring on convex terrain. Tree radial incrementmeasurements correlate and were synchronous with SPEI (r sq = 0.37, r(sub s) = 80). Increasing synchrony between tree ring growth and SPEI indicates that drought has reduced the ecological niche of Siberian pine. The results also showed the primary role of drought stress on Siberian pine mortality. A secondary role may be played by bark beetles and root fungi attacks. The observed Siberian pine mortality is part of a broader phenomenon of "dark needle conifers" (DNC, i.e., Siberian pine, fir and spruce) decline and mortality in European Russia, Siberia, and the Russian Far East. All locations of DNC decline coincided with areas of observed drought increase. The results obtained are one of the first observations of drought-induced decline and mortality of DNC at the southern border of boreal forests. Meanwhile if model projections of increased aridity are correct DNC, within the southern part of its range may be replaced by drought-resistant Pinus silvestris and Larix sibirica.

  17. Methane release from the East-Siberian Arctic Shelf and its connection with permafrost and hydrate destabilization: First results and potential future developments

    Science.gov (United States)

    Shakhova, N.; Semiletov, I.

    2012-04-01

    The East Siberian Arctic Shelf (ESAS) is home to the world's largest hydrocarbon stocks, which consist of natural gas, coal bed methane (CH4), and shallow Arctic hydrates. Until recently, the ESAS was not considered a CH4 source due to the supposed impermeability of sub-sea permafrost, which was thought to completely isolate the CH4 beneath from modern biogeochemical cycles. However, the ESAS represents an enormous potential CH4 source that could be responsive to ongoing global warming. Such response could occur in substantially shorter time than that of terrestrial Arctic ecosystems, because sub-sea permafrost has experienced long-lasting destabilization initiated by its inundation during the Holocene ocean transgression. ESAS permafrost stability and integrity is key to whether sequestered ancient carbon escapes as the potent greenhouse gas CH4. Recent data suggest the sub-sea permafrost is currently experiencing significant changes in its thermal regime. For example, our recent data obtained in the ESAS during the drilling expedition of 2011 showed no frozen sediments at all within the 53 m long drilling core at water temperatures varying from -0.6°C to -1.3°C. Unfrozen sediments provide multiple potential CH4 migration pathways. We suggest that open taliks have formed beneath the areas underlain or influenced by the nearby occurrence of fault zones, under paleo-valleys, and beneath thaw lakes submerged several thousand years ago during the ocean transgression. Temporary gas migration pathways might occur subsequent to seismic and tectonic activity in an area, due to sediment settlement and subsidence; hydrates could destabilize due to development of thermokarst-related features or ice-scouring. Recently obtained geophysical data identified numerous gas seeps, mostly above prominent reflectors, and the ubiquitous occurrence of shallow gas-charged sediments containing numerous gas chimneys, underscoring the likelihood that the ability of sub-sea permafrost to

  18. Methane emission from sub-sea permafrost in the East Siberian Arctic shelf: model-based evaluation of potential impact on global climate

    Science.gov (United States)

    Anisimov, O. A.; Lavrov, S. A.; Borzenkova, I. I.

    2011-12-01

    Several recent publications suggest that the observed high concentration of methane over the East Siberian Shelf (ESS) may be attributed to thawing and increased gas permeability (through taliks) of the sub-sea permafrost. Methane is released from unstable gas hydrates and propagates through newly formed taliks in the bottom sediments to the water and further to the atmosphere. Under sustained warming in the following decades it may have potentially dramatic effect on global climate. In this study we examine this hypothesis using comprehensive modelling approach. Direct observations indicate that since the mid-1980s bottom waters over the ESS warmed by ca. 2.1°C. We used the model to examine whether such changes may have caused substantial degradation of methane bearing sub-sea permafrost and CH4 supersaturation of the ESS sea waters. The model is based on the heat transfer equation and explicitly accounts for the effect of salt diffusion in the bottom sediments by coupling the thermal and mass fluxes. We forced the model by the prescribed seasonal bottom water temperature and salinity to calculate changes in the thermal state of permafrost after the inundation of the ESS, and to predict the changes in the following 1000 years. We used a climate scenario suggesting that at the time of inundation (ca 8 Ky BP) the top sediment layer warmed by ca. 12 °C from -13.5 °C (mean annual air temperature) to -1.5 °C (bottom water temperature). Afterwards temperature remained unchanged until 1985. Since then in accord with modern observations we imposed 0.09°C/year trend until 2100, and prescribed temperature to constant value of 11.5 °C afterwards. The rate of temperature change in the 21st century in this highly schematic scenario by far exceeds all IPCC projections. We did it intentionally to explore the most extreme pathway for potential sub-see permafrost degradation underneath the ESS. Model results indicated ca 1 m deepening of the upper sub-sea permafrost boundary

  19. Volatiles formation from grape must fermentation using a cryophilic and thermotolerant yeast.

    Science.gov (United States)

    Kopsahelis, Nikolaos; Bosnea, Loulouda; Kanellaki, Maria; Koutinas, Athanasios A

    2012-07-01

    Grape must fermentation performance and volatiles formation by simultaneously cryophilic and thermotolerant yeast (strain AXAZ-1), isolated from grapes in Greece, was evaluated in a wide temperature range (5-40°C). Yeast strain was immobilized on brewer's spent grains (BSG) and the formed biocatalyst was introduced into a Multi-Stage Fixed Bed Tower (MFBT) bioreactor. Almost complete sugar utilization from the aforementioned biocatalyst was observed in a wide temperature spectrum, ranging from 5 °C to 37 °C, while at 40 °C residual sugar was up to 29 g/l. Time to complete fermentation with the immobilized yeast ranged from 290 h at 5 °C and 120 h at 40 °C to 25 h at 33 °C. The daily ethanol productivity reached maximum (88.6 g/l) and minimum (5.6 g/l) levels at 33 °C and 5 °C, respectively. The aroma-related compounds' profiles of immobilized cells at different fermentation temperatures were evaluated by using solid phase microextraction (SPME) gas chromatography/mass spectrometry (GC/MS). Must fermentation resulted in a high-quality fermentation product due to the low concentrations of higher and amyl alcohols at all temperatures tested. AXAZ-1 is a very promising strain for quality wine production, as it is capable of performing fermentations of high ethanol concentration and productivities in both low and high temperatures.

  20. Outbreaks of Mass Reproduction of Siberian Moth in the 2nd Half of the 20th Century in Priamurye

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Siberian moth Dendcrolimus superans sibiricus Tschetw. is the main important insect pest not only in Siberian coniferous taiga, but it often forms foci of mass reproduction in larch stands in the Russian Far East. This article has described outbreaks of the Siberian moth and other insect pests since 1960 till now.

  1. Evolution of the West Siberian Basin

    Energy Technology Data Exchange (ETDEWEB)

    Vyssotski, A.V. [Chevron, 1500 Louisiana Street, Houston (United States); Vyssotski, V.N. [TNK-BP, 1 Arbat St, Moscow 119019 (Russian Federation); Nezhdanov, A.A. [OOO TyumenNIIgiprogas, 2 Vorovskogo Str., Tyumen 625019 (Russian Federation)

    2006-01-01

    The West Siberian Basin is one of the largest intra-cratonic basins of the world and an important hydrocarbon province of Russia. Perhaps the most important geologic event in Siberia was the emplacement of basalts around {approx} 250Ma (i.e. Permo-Triassic boundary) covering an area of about 5x10{sup 6} km{sup 2}. This volcanism may be responsible for a mass extinction that occurred around Permian-Triassic time. The pre-basaltic rifting event was limited to the north-northeastern sector of the basin. Initial basin wide subsidence took place in the Jurassic as a result of which the western part of Siberia became the West Siberian Basin bounded by uplifts to the east and to the west. One of the surprising aspects of the West Siberian Basin is the abundance of sub-vertical faults believed to be result of strike-slip movement. While intra-plate inversions and fault reactivation structures have been observed in many cratons, sub-vertical faults observed in the West Siberian Basin are unique because of their geometries and abundance. The differentiation between the effects of tectonics and eustasy in cratonic basins is simple-the global eustatic signal is basin-wide with regional and local tectonics playing an overprinting role. Thus, the Middle Jurassic-Turonian 1st, 2nd, and 3rd order cycles in the West Siberian Basin were primarily driven by eustasy. The Middle Jurassic-Turonian series can be subdivided into two second-order and 16 third-order transgressive-regressive cycles (within dataset extent). Fourth-order cycles appear to be controlled by delta shifting. Although extensively studied, a number of fundamental questions regarding the origin and evolution of the West Siberian Basin remain unresolved or poorly documented in the literature. [Author].

  2. Variability and ecology of Siberian larch species

    Energy Technology Data Exchange (ETDEWEB)

    Abaimov, A.P.; Milyutin, L.I. [Russian Academy of Sciences, Krasnoyarsk (Russian Federation). Sukachev Inst. of Forest, Siberian Branch; Lesinski, J.A.; Martinsson, Owe [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Silviculture

    1998-12-31

    There are at least four larch taxons distinguished in Siberia that occupy almost 37 percent of the the Russian forests. The natural distribution of the taxons is clinal from the west to the east with L. sibirica Ledeb. in the west followed by L. x czekanowskii Szafer, L. gmelinii Rupr. and L. cajanderi Mayr. L. sibirica and L. x czekanowskii are phytocenosis builders only at the northern timberline and in the South-Siberian mountains whereas L. gmelinii and L. cajanderi are the main species over the vast territory within and beyond the permafrost zone of East Siberia. Due to large variety of growing conditions, the main features of the larch forests in terms of age structure and growth rates are also enormously variable. Thanks to specific life strategies with respect to seed dispersion patterns and very high adaptability to fires that often affect Siberian forests, these larch species regenerate very well being only seldom temporary replaced by Betula sp. forming secondary forest associations. Larch forests of different categories (protective and commercial) are exploited and regenerated in the same way as it is applied for Scots pine in Siberia. There is a growing interest in Siberian larch species among researchers and practitioners from abroad, mainly due to their fast growth and excellent wood properties. Some attempts of introducing Siberian larch species as commercial plantations have already been initiated in western countries. However, the knowledge of botanical, ecological and silvicultural features of Siberian larch species is rather poor outside of Russia. Because of its economic importance for Russian forestry the Siberian larch species have been comprehensively studied for many years and many papers as well as a number of monographs have been published, most of them in Russian. The large Russian expertise concerning regionalisation of seed sources, seed crop and quality, seed orchards, seedling production in nurseries and silvicultural practices in

  3. Assessment of Sea-Air Fluxes of Methane from the East Siberian Arctic Shelf Based on Multi-Year High-Precision Observations in the Atmospheric Boundary Layer and Seawater

    Science.gov (United States)

    Salyuk, A.; Semiletov, I. P.; Repina, I.; Chernykh, D.; Kosmach, D.; Shakhova, N. E.

    2015-12-01

    The latitude specific monthly mean (LSMM) methane (CH4) mixing ratio in the Arctic region atmospheric boundary layer (ABL) is established at 1.85 ppm (monitoring station at Barrow, Alaska, USA). This LSMM is about 10% higher than in Antarctica and about 5-7% higher than in the mid-latitudes, where the majority of anthropogenic activity occurs. So far, there is no reasonable explanation for the atmospheric CH4 maximum above the Arctic and no models have succeeded in satisfactorily reproducing the inter-polar gradient, due to the assumption that there are no Arctic region CH4 sources sufficient to serve year-round to maintain the existing maximum. The East Siberian Arctic Shelf (ESAS), from which extensive CH4 release was recently reported, has never been considered to be an atmospheric source of CH4, because no knowledge existed about this area until very recently. One focus of our multi-year ESAS investigations was to collect a comprehensive data set of continuous ABL CH4 mixing ratio measurements along with continuous measurements of dissolved CH4 in the surface water. When collecting the data set, we aimed to assess CH4 fluxes by using top-down and bottom-up approaches. Achieving representative spatial coverage of the study area with high-resolution, high-accuracy measurements was our priority. We collected data from 2006-2012 with a high-accuracy fast CH4 analyzer; two sonic anemometers measured the 3D wind vector and sonic temperature; a meteorological station measured wind speed and direction, moisture, and temperature; and an open path infrared gas analyzer measured H2O and CO2. Other instruments included a pressure transducer and a motion package that measured 6 components of ship's motion and also acceleration, magnetic field, and position. In 2011 and 2012 we performed such measurements in the outer ESAS seepage area. Data were synchronized in time and space to demonstrate correspondence of increased atmospheric CH4 levels (up to 3.2 ppm) to observed

  4. Hydrocarbon potential of hydrocarbon source rocks of the New Siberian Islands, Russian Arctic

    Science.gov (United States)

    Gaedicke, Christoph; Sobolev, Peter; Franke, Dieter; Piepjohn, Karsten; Brandes, Christian; Kus, Jolanta; Scheeder, Georg

    2016-04-01

    The New Siberian Islands are bridging the Laptev Sea with the East Siberian Sea. The Laptev and East Siberian Seas cover large areas of the continental margin of northeastern Arctic Russia. The East Siberian Shelf encompassing an area of 935.000 km2 is still virtually unexplored and most of the geological models for this shelf are extrapolations of the geology of the New Siberian Islands, the Wrangel Island and the northeast Siberian landmass. Apart from few seismic reflection lines, airborne magnetic data were the primary means of deciphering the structural pattern of the East Siberian Shelf. The Laptev Shelf covers an area of about 66.000 km2 and occupies a shelf region, where the active mid-oceanic spreading ridge of the Eurasian Basin hits the slope of the continental margin. During the joint VSEGEI/BGR field expedition CASE 13 (Circum Arctic Structural Events) in summer 2011 we sampled outcrops from the New Siberian Archipelago including the De Long Islands. 102 samples were collected and the Upper Palaeozoic to Lower Cenozoic units are found to be punctuated by several organic-rich intervals. Lithology varies from continental dominated clastic sedimentary rocks with coal seams to shallow marine carbonates and deep marine black shales. Rock-Eval pyrolysis, gas chromatography/mass spectrometry and organic petrography studies were performed to estimate organic matter contents, composition, source, and thermal maturity. According to the results of our analyses, samples from several intervals may be regarded as potential petroleum source rocks. The Lower Devonian shales have the highest source rock potential of all Paleozoic units. Triassic samples have a good natural gas potential. Cretaceous and Cenozoic low-rank coals, lignites, and coal-bearing sandstones display some gas potential. The kerogen of type III (humic, gas-prone) dominates. Most of the samples (except some of Cretaceous and Paleogene age) reached the oil generation window.

  5. Siberian Platform: Geology and Natural Bitumen Resources

    Science.gov (United States)

    Meyer, Richard F.; Freeman, P.A.

    2006-01-01

    Summary: The Siberian platform is located between the Yenisey River on the west and the Lena River on the south and east. The Siberian platform is vast in size and inhospitable in its climate. This report is concerned principally with the setting, formation, and potential volumes of natural bitumen. In this report the volumes of maltha and asphalt referred to in the Russian literature are combined to represent natural bitumen. The generation of hydrocarbons and formation of hydrocarbon accumulations are discussed. The sedimentary basins of the Platform are described in terms of the Klemme basin classification system and the conditions controlling formation of natural bitumen. Estimates of in-place bitumen resources are reviewed and evaluated. If the bitumen volume estimate is confined to parts of identified deposits where field observations have verified rock and bitumen grades values, the bitumen resource amounts to about 62 billion barrels of oil in-place. However, estimates of an order of magnitude larger can be obtained if additional speculative and unverified rock volumes and grade measures are included.

  6. Influence of Siberian High on temperature variability over northern areas of South Asia

    Science.gov (United States)

    Riaz, Syed Muhammad Fahad; Iqbal, Muhammad Jawed; Baig, Mirza Jawwad

    2017-05-01

    Siberian High pressure plays a significant role in wintertime climate variability over South Asia. It brings coldest air masses in the region. The available literature has linked Siberian High with climate of East Asia, central Asia, and Eurasia. This paper examines the linkage between Siberian High pressure and inter-annual variations in temperature over the region of South Asia during winters. The methods employed in this study are that of centers of action approach, maximum covariance, and canonical correlation analyses. The wintertime temperature is not only significantly influenced by the intensity of Siberian High pressure, but it is also significantly correlated with zonal movement of Indian Ocean High. The intensity of Siberian High pressure explains more variance of the temperature during winters over the South Asian region than that of large-scale circulation phenomena, namely, Arctic Oscillation, North Atlantic Oscillation, and El-Nino-Southern Oscillation. A linear model of wintertime temperature has also been constructed using the Siberian High pressure index and the Indian Ocean High longitudinal index, which explains 28% variability of wintertime temperature for the Northern part of South Asia. We have also presented the justification that this statistical evidence is supported by the circulations and changes in the atmosphere. The modes having maximum possible covariance between the regional wintertime temperature and sea-level pressure of Siberian High have been isolated using the method of maximum covariance analysis and the modes having maximum possible correlations between the two fields have been isolated using canonical correlation analysis.

  7. Polarized protons and Siberian snakes

    Energy Technology Data Exchange (ETDEWEB)

    Krisch, A.D. [Michigan Univ., Ann Arbor, MI (United States). Randall Lab. of Physics

    1999-07-01

    The lecture started with a brief review of the history of polarized proton beams. Then it described the unexpected and still unexplained large transverse spin effects found in high energy proton spin experiments at the ZGS, AGS, and Fermilab. Next there was detailed discussion of Siberian snakes and some of their tests at the IUCF Cooler Ring. Finally there was a review of the use of Siberian Snakes in some possible high energy polarized proton beams at RHIC, HERA and Fermilab. Since a similar lecture is being published elsewhere, this manuscript will only contain this brief summary and the references. (author)

  8. Taxonomic characterization, adaptation strategies and biotechnological potential of cryophilic yeasts from ice cores of Midre Lovénbreen glacier, Svalbard, Arctic.

    Science.gov (United States)

    Singh, Purnima; Tsuji, Masaharu; Singh, Shiv Mohan; Roy, Utpal; Hoshino, Tamotsu

    2013-04-01

    Ten strains of cryophilic yeast were studied from glacier ice cores of Svalbard, Arctic. The ice melt samples contained about 3×10(3) - 1×10(4) colony forming unit (CFUs) per ml. Sequence analysis of the isolates, using D1/D2 domain identified five species of yeasts: Cryptococcus adeliensis (MLB-18 JX192655), Cryptococcus albidosimilis (MLB-19 JX192656), Cryptococcus saitoi (MLB-22 JX192659), Rhodosporidium lusitaniae (MLB-20 JX192657), and Rhodotorula mucilaginosa (MLB-27 JX192664). Effect of temperature on growth of these isolates was studied. The strains are able to grow at temperatures ranging between 1 and 20°C. Screening of the cultures for amylase, cellulase, protease, lipase, urease and catalase activity were carried out indicating varying amounts of enzyme production at different temperatures. Characterization of lipase in strain Cryptococcus sp. MLB-24 was performed. Fatty acid methyl ester (FAME) analysis of the cultures grown at four different temperatures (1, 4, 15, and 20°C) was also done. Decrease in temperature was reported to cause increase in concentration of unsaturated fatty acids. High amount of oleic acid accumulated with increase in temperature. These fatty acids possibly help the strains to survive in glacial ice core cold environment. The extracellular and intracellular filtrate of the cultures showed negative antifreeze protein (AFP) activity. The observations indicate that probably the isolates in the present undertaking adapt to low temperatures, by enzyme and PUFA secretion rather than by antifreeze protein secretion.

  9. [Induction of androgenic cultures in Siberian larch].

    Science.gov (United States)

    Ivanova, A N; Tret'iakova, I N; Viazovetskova, A S

    2006-01-01

    Male generative buds of the Siberian larch have no organic quiescence during the autumn-winter period and are capable of completing the development of male generative structures under favorable conditions. When microsporophylls of the Siberian larch were cultivated on medium MS with 0.2 mg/l 2,4-D, embryoids of two types were obtained: directly from the microspore body and via formation of organogenic callus. This means that in the Siberian larch, direct and indirect androgenesis in vitro is possible. The Siberian larch pollen was first germinated in vitro, which was enhanced by pretreatment with hydrogen peroxide.

  10. The facial levels of the melting of the Permian - Triassic trap basalts of West Siberian plate and Siberian platform.

    Science.gov (United States)

    Sharapov, Victor; Vasiliev, Yury

    2014-05-01

    Statistical processing of numerical information allow to indicate the following regional petro- geochemical characteristics of Permo-Triassic trap magmatism in West Siberian plate WSP: 1) Examined regional petrochemical trend of major element chemistry variation of trap magmatism from north to the south is appeared in increase of the acidity, a decrease of Mg and alumina and potassium of the igneous rocks, for other components existing data do not allow to determine regularities; 2) According to (La/Yb)n, (Gd/Yb)n and(Tb/Yb)n ratios all basic melts belong to the spinel facie. In general the trap basalts of Siberian Platform reveal the following structural facial features are characteristic: 1) From west and east the region of the basalt effusions practically coincides with the area of Devonian sea depressions, 2) from the west to east lava shields are framed by the zones of the variously differentiated intrusive basic bodies grouped within the zones of arched and linear faults; 3) the region of effusive volcanics appearance has the zone - distributed structural - material areas, the tholeitic "super-shield" (plateau Putorana) occupyingthe center part of the Tunguska syneclise), framed from the West, and NW by the local lava shields located in rounded depressions( mulda) in which the lavas are more magnesian, titaniferrous and alkaline. 4) examined overall petrochemical zonation of basic rocks in Siberian platform reveal general decrease from the Norilsk mulda to Angara- Ilim iron-ore deposit region, with the growth of Ti02 and alkalinity of the basic rocks. The statistical wavelet analysis of the cyclic recurrence of the effusive rock sections along the eastern board of Khatanga rift show substantially different characteristics of the spectra of time series, in Norilsk -Kharaelakh depression the low-frequency modules predominate, whereas for The Meimecha-Kotuy effusion section the high frequency values are characteristic. The comparison of the possible facial

  11. Local Mesozoic remagnitization of New Siberian Islands sediments

    Science.gov (United States)

    Chernova, Anna; Metelkin, Dmitry; Vernikovsky, Valery; Matushkin, Nikolay

    2017-04-01

    New Siberian Islands (NSI) terrane is one of the key structures of the East Arctic but its tectonic history is still debated. Mesozoic stage in the East Arctic is characterized by active geodynamic events such as closing of the South Anyui Ocean, South Anyui suture forming and Verkhoyansk-Chukotka folding in which NSI terrane has been involved during collision with Siberia. On Lyakhov islands there are discovered thick clastic strata and it is expected that its accumulation occurred in the foretrough during Anyui orogeny in the Late Jurassic - Early Cretaceous [Danukalova, 2009]. During international expeditions to the New Siberian Islands in 2011 and 2013 for paleomagnetic studies Triassic and Devonian deposits on the Kotelny Is. and Late Jurassic-Early Cretaceous sediments of Stolbovoi Is. and Great Lyakhov Is. were tested. The collection was studied by standard paleomagnetic methods and the paleomagnetic directions for these objects were obtained as a result of stepwise demagnetization. The synchronicity of determined magnetization and rock formation was verified by fold test. For all of them it was negative that means the magnetization is post-folding. To estimate the age of expected remagnetization we compared the poles calculated on directions in geographic coordinates with Mesozoic interval of Siberian APWP [Metelkin et al., 2010]. It revealed that obtained NST poles match with its 140-80 Ma interval within the error limits. So we can assume that remagnetization of sediments located along the southern and western boundary of the NSI archipelago coincides with the closure of an oceanic basin and end of accretion-collisional processes associated with the attaching the NSI terrane to Siberia.

  12. Spin flipping in rings with Siberian Snakes

    Energy Technology Data Exchange (ETDEWEB)

    Mane, S.R. [Convergent Computing Inc., P.O. Box 561, Shoreham, NY 11786 (United States)], E-mail: srmane@optonline.net

    2009-07-01

    I display numerical spin tracking simulations for spin flippers in model storage rings with full or nearly full Siberian Snakes. In many cases, the results differ from the predictions using the Froissart-Stora formula.

  13. Accelerating Polarized Protons with Siberian Snakes

    Energy Technology Data Exchange (ETDEWEB)

    Krisch, A.D. [Randall Laboratory of Physics, University of Michigan, Ann Arbor (United States)

    1998-05-01

    There is a brief review of the history of polarized proton beams and the unexpected and still unexplained large transverse spin effects found in high energy proton spin experiments at the ZGS, AGS and Fermilab. Next there is a detailed discussion of Siberian snakes and some of their tests at the IUCF Cooler Ring. Finally there is a report on the use of Siberian snakes in some possible high energy polarized proton beams at RHIC, HERA and Fermilab. (author) 19 refs, 12 figs

  14. Siberian Arctic black carbon sources constrained by model and observation

    Science.gov (United States)

    Winiger, Patrik; Andersson, August; Eckhardt, Sabine; Stohl, Andreas; Semiletov, Igor P.; Dudarev, Oleg V.; Charkin, Alexander; Shakhova, Natalia; Klimont, Zbigniew; Heyes, Chris; Gustafsson, Örjan

    2017-02-01

    Black carbon (BC) in haze and deposited on snow and ice can have strong effects on the radiative balance of the Arctic. There is a geographic bias in Arctic BC studies toward the Atlantic sector, with lack of observational constraints for the extensive Russian Siberian Arctic, spanning nearly half of the circum-Arctic. Here, 2 y of observations at Tiksi (East Siberian Arctic) establish a strong seasonality in both BC concentrations (8 ngṡm-3 to 302 ngṡm-3) and dual-isotope-constrained sources (19 to 73% contribution from biomass burning). Comparisons between observations and a dispersion model, coupled to an anthropogenic emissions inventory and a fire emissions inventory, give mixed results. In the European Arctic, this model has proven to simulate BC concentrations and source contributions well. However, the model is less successful in reproducing BC concentrations and sources for the Russian Arctic. Using a Bayesian approach, we show that, in contrast to earlier studies, contributions from gas flaring (6%), power plants (9%), and open fires (12%) are relatively small, with the major sources instead being domestic (35%) and transport (38%). The observation-based evaluation of reported emissions identifies errors in spatial allocation of BC sources in the inventory and highlights the importance of improving emission distribution and source attribution, to develop reliable mitigation strategies for efficient reduction of BC impact on the Russian Arctic, one of the fastest-warming regions on Earth.

  15. Methane fluxes from the sea to the atmosphere across the Siberian shelf seas

    Science.gov (United States)

    Thornton, Brett F.; Geibel, Marc C.; Crill, Patrick M.; Humborg, Christoph; Mörth, Carl-Magnus

    2016-06-01

    The Laptev and East Siberian Seas have been proposed as a substantial source of methane (CH4) to the atmosphere. During summer 2014, we made unique high-resolution simultaneous measurements of CH4 in the atmosphere above, and surface waters of, the Laptev and East Siberian Seas. Turbulence-driven sea-air fluxes along the ship's track were derived from these observations; an average diffusive flux of 2.99 mg m-2 d-1 was calculated for the Laptev Sea and for the ice-free portions of the western East Siberian Sea, 3.80 mg m-2 d-1. Although seafloor bubble plumes were observed at two locations in the study area, our calculations suggest that regionally, turbulence-driven diffusive flux alone accounts for the observed atmospheric CH4 enhancements, with only a local, limited role for bubble fluxes, in contrast to earlier reports. CH4 in subice seawater in certain areas suggests that a short-lived flux also occurs annually at ice-out.

  16. Impact of Siberian forest fires on the atmosphere over the Korean Peninsula during summer 2014

    Science.gov (United States)

    Jung, Jinsang; Lyu, Youngsook; Lee, Minhee; Hwang, Taekyung; Lee, Sangil; Oh, Sanghyub

    2016-06-01

    Extensive forest fires occurred during late July 2014 across the forested region of Siberia, Russia. Smoke plumes emitted from Siberian forest fires underwent long-range transport over Mongolia and northeast China to the Korean Peninsula, which is located ˜ 3000 km south of the Siberian forest. A notably high aerosol optical depth of ˜ 4 was observed at a wavelength of 500 nm near the source of the Siberian forest fires. Smoke plumes reached 3-5 km in height near the source and fell below 2 km over the Korean Peninsula. Elevated concentrations of levoglucosan were observed (119.7 ± 6.0 ng m-3), which were ˜ 4.5 times higher than those observed during non-event periods in July 2014. During the middle of July 2014, a haze episode occurred that was primarily caused by the long-range transport of emission plumes originating from urban and industrial complexes in East China. Sharp increases in SO42- concentrations (23.1 ± 2.1 µg m-3) were observed during this episode. The haze caused by the long-range transport of Siberian forest fire emissions was clearly identified by relatively high organic carbon (OC) / elemental carbon (EC) ratios (7.18 ± 0.2) and OC / SO42- ratios (1.31 ± 0.07) compared with those of the Chinese haze episode (OC / EC ratio: 2.4 ± 0.4; OC / SO42- ratio: 0.21 ± 0.05). Remote measurement techniques and chemical analyses of the haze plumes clearly show that the haze episode that occurred during late July 2014 was caused mainly by the long-range transport of smoke plumes emitted from Siberian forest fires.

  17. CULTURAL LANDSCAPES AND LOCAL IDENTITIES IN THE DEVELOPMENT OF EASTERN SIBERIAN CITIES (FROM LATE 18TH TO EARLY 19TH CENTURY

    Directory of Open Access Journals (Sweden)

    Maria Mihailovna Plotnikova

    2015-09-01

    Full Text Available This article considers the interaction of geographical and cultural landscape in identity formation of the East-Siberian cities of Irkutsk, Krasnoyarsk, and Kirensk in the late 18th century and early 19th century. The comparative analysis of the European city of Valga with the East-Siberian city of Kirensk revealed that, while most of the citizens of the European city were artisans, the military personnel played a significant role in the outskirts of the Russian Empire. At the end of 18th century and during the early 19th century, the Eastern Siberian cities collected taxes as revenue for the city, using the advantage of their geographical position. The author concludes that the study into the essence of the "genius loci" of a city gives insight into the origins of the local identity formation.

  18. Proximity to Intrinsic Depolarizing Resonances with a Partial Siberian Snake

    Science.gov (United States)

    Crandell, D. A.; Alexeeva, L. V.; Anferov, V. A.; Blinov, B. B.; Chu, C. M.; Caussyn, D. D.; Courant, E. D.; Gladycheva, S. E.; Hu, S.; Krisch, A. D.; Nurushev, T. S.; Phelps, R. A.; Ratner, L. G.; Varzar, S. M.; Wong, V. K.; Derbenev, Ya. S.; Lee, S. Y.; Rinckel, T.; Schwandt, P.; Sperisen, F.; Stephenson, E. J.; von Przewoski, B.; Baiod, R.; Russell, A. D.; Ohmori, C.; Sato, H.

    1996-05-01

    Partial Siberian snakes are effective in overcoming imperfection depolarizing resonances, but they may also change the crossing energy for intrinsic depolarizing resonances. We experimentally investigated the effect of a partial Siberian snake near intrinsic depolarizing resonances with stored 140 MeV and 160 MeV polarized proton beams. Using various partial Siberian snake strengths up to 30%, depolarization was observed; this may be due to a change in the spin precession frequency which moves the energy of nearby intrinsic depolarizing resonances.

  19. The emergence of obesity among indigenous Siberians.

    Science.gov (United States)

    Snodgrass, J Josh; Leonard, William R; Sorensen, Mark V; Tarskaia, Larissa A; Alekseev, Vasili P; Krivoshapkin, Vadim

    2006-01-01

    Once considered a disease of affluence and confined to industrialized nations, obesity is currently emerging as a major health concern in nearly every country in the world. Available data suggest that the prevalence rate of obesity has reached unprecedented levels in most developing countries, and is increasing at a rate that far outpaces that of developed nations. This increase in obesity has also been documented among North American circumpolar populations and is associated with lifestyle changes related to economic development. While obesity has not been well studied among indigenous Siberians, recent anthropological studies indicate that obesity and its associated comorbidities are important health problems.The present study examines recent adult body composition data from four indigenous Siberian populations (Evenki, Ket, Buriat, and Yakut) with two main objectives: 1) to determine the prevalence of overweight and obesity among these groups, and 2) to assess the influence of lifestyle and socioeconomic factors on the development of excess body fat. The results of this study indicate that obesity has emerged as an important health issue among indigenous Siberians, and especially for women, whose obesity rates are considerably higher than those of men (12% vs. 7%). The present study investigated the association between lifestyle and body composition among the Yakut, and documented substantial sex differences in lifestyle correlates of obesity. Yakut men with higher incomes and who owned more luxury consumer goods were more likely to have excess body fat while, among Yakut women, affluence was not strongly associated with overweight and obesity.

  20. High levels of Y-chromosome differentiation among native Siberian populations and the genetic signature of a boreal hunter-gatherer way of life.

    Science.gov (United States)

    Karafet, Tatiana M; Osipova, Ludmila P; Gubina, Marina A; Posukh, Olga L; Zegura, Stephen L; Hammer, Michael F

    2002-12-01

    We examined genetic variation on the nonrecombining portion of the Y chromosome (NRY) to investigate the paternal population structure of indigenous Siberian groups and to reconstruct the historical events leading to the peopling of Siberia. A set of 62 biallelic markers on the NRY were genotyped in 1432 males representing 18 Siberian populations, as well as nine populations from Central and East Asia and one from European Russia. A subset of these markers defines the 18 major NRY haplogroups (A-R) recently described by the Y Chromosome Consortium (YCC 2002). While only four of these 18 major NRY haplogroups accounted for -95% of Siberian Y-chromosome variation, native Siberian populations differed greatly in their haplogroup composition and exhibited the highest phiST value for any region of the world. When we divided our Siberian sample into four geographic regions versus five major linguistic groupings, analyses of molecular variance (AMOVA) indicated higher phiST and phiCT values for linguistic groups than for geographic groups. Mantel tests also supported the existence of NRY genetic patterns that were correlated with language, indicating that language affiliation might be a better predictor of the genetic affinity among Siberians than their present geographic position. The combined results, including those from a nested cladistic analysis, underscored the important role of directed dispersals, range expansions, and long-distance colonizations bound by common ethnic and linguistic affiliation in shaping the genetic landscape of Siberia. The Siberian pattern of reduced haplogroup diversity within populations combined with high levels of differentiation among populations may be a general feature characteristic of indigenous groups that have small effective population sizes and that have been isolated for long periods of time.

  1. Ascarid infestation in captive Siberian tigers in China.

    Science.gov (United States)

    Peng, Zhiwei; Liu, Shijie; Hou, Zhijun; Xing, Mingwei

    2016-08-15

    The Siberian tiger is endangered and is listed by the International Union for the Conservation of Nature; the captive environment is utilized to maintain Siberian tiger numbers. Little information regarding the prevalence of parasites in Siberian tigers is available. A total of 277 fecal samples of Siberian tigers were analyzed in this study. The microscopic analysis indicated the presence of ascarid eggs of Toxascaris leonina and Toxocara cati. The ascarid infection rate was 67.5% in Siberian tigers. The internal transcribed spacer-1 (ITS-1) phylogenetic analysis indicated that T. leonina belonged to Toxascaris and that Toxo. cati belonged to Toxocara. The infestation rate and intensity of T. leonina were higher than those of Toxo. cati. One-way analysis of variance showed that the presence of T. leonina was significantly associated with age (Ptigers and is helpful for the prevention of the spread of infectious parasitic diseases among other tigers in the zoo.

  2. Insertion of helical Siberian snakes in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Luccio, A.; Pilat, F.

    1995-05-01

    Spin rotators and Siberian snakes for RHIC can be built using 4 helical magnets obtained, by twisting, from the cosine dipoles. The authors found that the fringe fields are important. In the calculations they have used a plausible model for the fringe. However, only magnetic measurements on the prototypes presently being built will allow a final optimization. The linear coupling at injection, {Delta}Q{sub min} < 10{sup {minus}2}, is well within the range of the RHIC decoupling system. At storage, the coupling introduced by the devices ({Delta}Q{sub min} < 10{sup {minus}4}) is negligible.

  3. Siberian Snakes in high-energy accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Mane, S R [Convergent Computing Inc, PO Box 561, Shoreham, NY 11786 (United States); Shatunov, Yu M [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation); Yokoya, K [National Laboratory for High-Energy Physics (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2005-09-01

    We review modern techniques to accelerate spin-polarized beams to high energy and to preserve their polarization in storage rings. Crucial to the success of such work is the use of so-called Siberian Snakes. We explain these devices and the reason for their necessity. Closely related to Snakes is the concept of 'spin rotators'. The designs and merits of several types of Snakes and spin rotators are examined. Theoretical work with Snakes and spin rotators, and experimental results from several storage rings, are reviewed, including the so-called Snake resonances. (topical review)

  4. Spin rotators and split Siberian Snakes

    Energy Technology Data Exchange (ETDEWEB)

    Roser, Thomas

    1994-03-01

    The study of spin effects in the collision of polarized high energy beams requires flexible and compact spin rotators to manipulate the beam polarization direction. Design criteria and specific examples are presented for high energy, orbit transparent spin rotators ranging from small angle rotators to be used for the excitation of spin resonances to large angle rotators to be used as Siberian Snakes. It is shown that all the requirements for spin rotators can be met with a simple 6-magnet spin rotator design, for which a complete continuous solution is presented.

  5. Spin rotators and split Siberian Snakes

    Energy Technology Data Exchange (ETDEWEB)

    Roser, T. (Brookhaven National Lab., Upton, NY (United States))

    1994-03-22

    The study of spin effects in the collision of polarized high energy beams requires flexible and compact spin rotators to manipulate the beam polarization direction. Design criteria and specific examples are presented for high energy, orbit transparent spin rotators ranging from small angle rotators to be used for the excitation of spin resonances to large angle rotators to be used as Siberian Snakes. It is shown that all the requirements for spin rotators can be met with a simple 6-magnet spin rotator design, for which a complete continuous solution is presented. (orig.)

  6. Multiple Partial Siberian Snakes in the AGS

    Science.gov (United States)

    Takano, J.; Ahrens, L. A.; Bai, M.; Brown, K.; Courant, E. D.; Gardner, C. J.; Glenn, J. W.; Hattori, T.; Huang, H.; Lin, F.; Luccio, A. U.; MacKay, W. W.; Okamura, M.; Roser, T.; Tepikian, S.; Tsoupas, N.; Yip, K.; Zelenski, A.; Zeno, K.

    2007-06-01

    Polarized protons are accelerated up to 24.3 GeV in the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL). To accelerate the beam with preserving the polarization, two different types of helical dipole partial Siberian snake have been installed to the AGS. One is a superconducting magnet (Cold Snake, CSNK), and the other is a normal conducting one (Warm Snake, WSNK). With these snake magnets, the polarization at the AGS extraction achieved 65%. However, the AGS has spin mismatches at the injection and extraction. This description shows calculated results to have better spin matching with using two or three snakes.

  7. ACCELERATION OF POLARIZED BEAMS USING MULTIPLE STRONG PARTIAL SIBERIAN SNAKES.

    Energy Technology Data Exchange (ETDEWEB)

    ROSER,T.AHRENS,L.BAI,M.ET AL.

    2004-07-05

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20-30% partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.

  8. ACCELERATION OF POLARIZED BEAMS USING MULTIPLE STRONG PARTIAL SIBERIAN SNAKES.

    Energy Technology Data Exchange (ETDEWEB)

    ROSER,T.; AHRENS,L.; BAI,M.; COURANT,E.; GLENN,J.W.; GUPTA,R.C.; HUANG,H.; LUCCIO,A.U.; MACKAY,W.W.; TSOUPAS,N.; WILLEN,E.; OKAMURA,M.; TAKANO,J.

    2004-10-10

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20-30% partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.

  9. Beam polarization during a Siberian snake turn-on

    CERN Document Server

    Anferov, V A

    1999-01-01

    Installing Siberian snakes in a circular proton accelerator allows one to overcome all spin depolarizing resonances even at very high energies. However, Siberian snake application at low energies is technically rather difficult. Turning snake on at some energy during acceleration would allow using Siberian snakes even in rings with low injection energies. It is shown that the beam polarization would be preserved during the snake ramp, provided that the snake is turned on in more than ten turns, and the energy is set near a half-integer G gamma.

  10. Acceleration of Polarized Beams Using Multiple Strong Partial Siberian Snakes

    Science.gov (United States)

    Roser, T.; Ahrens, L. A.; Bai, M.; Courant, E. D.; Glenn, J. W.; Gupta, R. C.; Huang, H.; Luccio, A. U.; Mackay, W. W.; Tsoupas, N.; Willen, E.; Okamura, M.; Takano, J.

    2005-08-01

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization, but full Siberian snakes cause intolerably large orbit excursions. Using a 20 - 30 % partial Siberian snake, both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical super-conducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.

  11. Mapping post-disturbance stand age distribution in Siberian larch forest based on a novel method

    Science.gov (United States)

    Chen, D.; Loboda, T. V.; Krylov, A.; Potapov, P.

    2014-12-01

    The Siberian larch forest, which accounts for nearly 20% of the global boreal forest biome, is unique, important, yet significantly understudied. These deciduous needleleaf forests with a single species dominance over a large continuous area are not found anywhere except the extreme continental zones of Siberia and the Russian Far East. Most of these forests are located in remote and sparsely populated areas and, therefore, little is known about spatial variability of their structure and dynamics. Wall-to-wall repeated observations of this area are available only since the 2000s. Previously, we developed methods for reconstruction of stand-age distribution from a sample of 1980-2000 disturbances in Landsat TM and ETM+ imagery. However, availability of those images in Siberian larch forests is particularly limited. Built upon the hypothesis that the spectral characteristics of the disturbed forest in the region change with time consistently, this paper proposes a novel method utilizing the newly released Global Forest Change (GFC) 2000-2012 dataset. We exploit the data-rich era of annual forest disturbance samples identified between 2000 and 2012 in the Siberian larch forest by the GFC dataset to build a robust training set of spectral signatures from regrowing larch forests as they appear in Landsat imagery in 2012. The extracted statistics are ingested into a random forest, which predicts the approximate stand age for every forested pixel in the circa 2000 composite. After merging the estimated stand age distribution for 1989-2000 with the observed disturbance records for 2001-2012, a gap-free 30 m resolution 24-year long record of stand age distribution is obtained. A preliminary accuracy assessment against the Advanced Very High Resolution Radiometer (AVHRR) burned area product suggested satisfactory performance of the proposed method.

  12. Assessment of Undiscovered Oil and Gas Resources of the West Siberian Basin Province, Russia, 2008

    Science.gov (United States)

    Schenk, Christopher J.; Bird, Kenneth J.; Charpentier, Ronald R.; Gautier, Donald L.; Houseknecht, David W.; Klett, Timothy R.; Moore, Thomas E.; Pawlewicz, Mark J.; Pitman, Janet K.; Tennyson, Marilyn E.

    2008-01-01

    The U.S. Geological Survey (USGS) recently assessed the undiscovered oil and gas potential of the West Siberian Basin Province in Russia as part of the USGS Circum-Arctic Resource Appraisal program. This province is the largest petroleum basin in the world and has an areal extent of about 2.2 million square kilometers. It is a large rift-sag feature bounded to the west by the Ural fold belt, to the north by the Novaya Zemlya fold belt and North Siberian Sill, to the south by the Turgay Depression and Altay-Sayan fold belt, and to the east by the Yenisey Ridge, Turukhan-Igarka uplift, Yenisey-Khatanga Basin, and Taimyr High. The West Siberian Basin Province has a total discovered oil and gas volume of more than 360 billion barrels of oil equivalent (Ulmishek, 2000). Exploration has led to the discovery of tens of giant oil and gas fields, including the Urengoy gas field with more than 3500 trillion cubic feet of gas reserves and Samotlar oil field with reserves of nearly 28 billion barrels of oil (Ulmishek, 2003). This report summarizes the results of a reassessment of the undiscovered oil and gas potential of that part of the province north of the Arctic Circle; a previous assessment that included the entire province was completed in 2000 (Ulmishek, 2000). The total petroleum system (TPS) and assessment units (AU) defined by the USGS for the assessments in 2000 were adopted for this assessment. However, only those parts of the Aus lying wholly or partially north of the Arctic Circle were assessed for this study.

  13. Siberian snakes for the Fermilab Main Injector

    Energy Technology Data Exchange (ETDEWEB)

    Anferov, V.A.; Baiod, R.; Courant, E.D. [and others

    1993-04-01

    Appropriate Siberian snakes were designed to maintain the proton beam polarization during acceleration in the Fermilab Main Injector from 8 to 150 GeV. Various snake designs were investigated to find one fitting into the 14 m straight section spaces with the required spin rotation axis and the minimum orbit excursion. The authors studied both cold and warm discrete magnet snakes as well as warm snakes with helical magnets. For the warm discrete magnet snake, obtaining small orbit excursions required a nearly longitudinal snake axis, while axes near {+-}45{degrees} are needed when using two snakes in a ring. The authors found acceptable snakes either by using superconducting magnets or by using warm magnets with a helical dipole field.

  14. Neuropeptide Y induces torpor-like hypothermia in Siberian hamsters.

    Science.gov (United States)

    Paul, Matthew J; Freeman, David A; Park, Jin Ho; Dark, John

    2005-09-01

    Intracerebroventricular (ICV) injections of neuropeptide Y (NPY) are known to decrease body temperature (Tb) of laboratory rats by 1-3 degrees C. Several NPY pathways in the brain terminate in hypothalamic structures involved in energy balance and thermoregulation. Laboratory rats are homeothermic, maintaining Tb within a narrow range. We examined the effect of ICV injected NPY on Tb in the heterothermic Siberian hamster (Phodopus sungorus), a species that naturally undergoes daily torpor in which Tb decreases by as much as 15-20 degrees C. Minimum effective dose was determined in preliminary testing then various doses of NPY were tested in cold-acclimated Siberian hamsters while food was withheld. NPY markedly reduced Tb in the heterothermic Siberian hamster. In addition, the reduction in Tb in 63% of the observations was sufficient to reach the criterion for daily torpor (Tb Siberian hamster. NPY treatment may be activating hypothalamic systems that normally integrate endogenous torpor-producing signals and initiate torpor.

  15. Field of a helical Siberian Snake

    Energy Technology Data Exchange (ETDEWEB)

    Luccio, A. [Brookhaven National Lab., Upton, NY (United States)

    1995-02-01

    To preserve the spin polarization of a beam of high energy protons in a circular accelerator, magnets with periodic magnetic field, called Siberian Snakes are being used. Recently, it was proposed to build Siberian Snakes with superconducting helical dipoles. In a helical, or twisted dipole, the magnetic field is perpendicular to the axis of the helix and rotates around it as one proceeds along the magnet. In an engineering study of a 4 Tesla helical snake, the coil geometry is derived, by twisting, from the geometry of a cosine superconducting dipole. While waiting for magnetic measurement data on such a prototype, an analytical expression for the field of the helice is important, to calculate the particle trajectories and the spin precession in the helix. This model will also allow to determine the optical characteristics of the snake, as an insertion in the lattice of the accelerator. In particular, one can calculate the integrated multipoles through the magnet and the equivalent transfer matrix. An expression for the field in the helix body, i.e., excluding the fringe field was given in a classical paper. An alternate expression can be found by elaborating on the treatment of the field of a transverse wiggler obtained under the rather general conditions that the variables are separable. This expression exactly satisfies Maxwell`s div and curl equations for a stationary field, {del} {center_dot} B = 0, {del} x B = 0. This approach is useful in that it will allow one to use much of the work already done on the problem of inserting wigglers and undulators in the lattice of a circular accelerator.

  16. Siberian larch at the western edge of its area

    Directory of Open Access Journals (Sweden)

    Kishchenko Ivan Tarasovich

    2015-06-01

    In the vertical structure of phytocenoses with Siberian larch up to 4 plant tiers are formed: the 1st and 2nd tier of the forest stand; the 3rd - grassy and shrubby; the 4th - mossy. The last two layers are usually developed very moderately, floristically poor and are noted for strong mosaic. There is no undergrowth. The reliable undergrowth of conifers is completely absent. Resumption of Siberian larch stopped 50-60 years ago.

  17. Complete mitochondrial genome of a wild Siberian tiger.

    Science.gov (United States)

    Sun, Yujiao; Lu, Taofeng; Sun, Zhaohui; Guan, Weijun; Liu, Zhensheng; Teng, Liwei; Wang, Shuo; Ma, Yuehui

    2015-01-01

    In this study, the complete mitochondrial genome of Siberian tiger (Panthera tigris altaica) was sequenced, using muscle tissue obtained from a male wild tiger. The total length of the mitochondrial genome is 16,996 bp. The genome structure of this tiger is in accordance with other Siberian tigers and it contains 12S rRNA gene, 16S rRNA gene, 22 tRNA genes, 13 protein-coding genes, and 1 control region.

  18. Did the Siberian Traps eruptions emit enough halogens to have an impact on ozone geochemistry?

    Science.gov (United States)

    Sibik, Svetlana; Edmonds, Marie; Villemant, Benoit; Thierry, Pauline; Polozov, Alexander

    2015-04-01

    The Siberian Traps Large Igneous Province is thought to have formed over 1 Ma at the end of the Permian, synchronous with the largest mass extinction in Earth's history. There remains much controversy as to the exact mechanism of the mass extinction, but all hypotheses revolve around the emission of volatiles in various forms. The research to date has tended to focus on sulfur and carbon rather than halogen degassing, despite this being probably critical in terms of environmental impact as they might have been played a crucial role in ozone layer depletion and therefore promote mass extinction. Current study aims to look at the behaviour of chlorine, bromine, iodine and fluorine to evaluate the halogen budget contribution from heterogeneous mantle source and from evaporates, which dominate in the south (Cambrian evaporites) and north (Devonian evaporites) of Siberian platform. For this study we use basaltic sills and lava flows emplaced in the area with no volatile-rich sediments south-east from Norilsk (Dyupkin lake and Lower Tunguska river regions) and a sill intruded into evaporates in Nepa location in the south of the platform, originally aimed at prospecting for potassium salts. Borehole samples of basalts intruded into evaporites might have been penetrated by salts and anhydrite. In order to eliminate this effect and ensure that we analyse halogen contents in pure basalts prior to any further analysis the samples were specifically treated so that penetrated material was removed as leachates. Whole rock fine powders of basalts were analysed for halogens, major and trace elements. The solutions obtained by basalt pyrohydrolysis extraction, leachates of basaltic powders and dissolved evaporites were analysed by ion chromatography for chlorine and fluorine and by ICP-MS for bromine and iodine. Basalts intruded into evaporites demonstrate predicted pronounced chlorine, bromine and iodine enrichments associated with salt assimilation. The results show that bromine

  19. Exhuming the Meso–Cenozoic Kyrgyz Tianshan and Siberian Altai-Sayan: A review based on low-temperature thermochronology

    Directory of Open Access Journals (Sweden)

    Stijn Glorie

    2016-03-01

    Full Text Available Thermochronological datasets for the Kyrgyz Tianshan and Siberian Altai-Sayan within Central Asia reveal a punctuated exhumation history during the Meso–Cenozoic. In this paper, the datasets for both regions are collectively reviewed in order to speculate on the links between the Meso–Cenozoic exhumation of the continental Eurasian interior and the prevailing tectonic processes at the plate margins. Whereas most of the thermochronological data across both regions document late Jurassic–Cretaceous regional basement cooling, older landscape relics and dissecting fault zones throughout both regions preserve Triassic and Cenozoic events of rapid cooling, respectively. Triassic cooling is thought to reflect the Qiangtang–Eurasia collision and/or rifting/subsidence in the West Siberian basin. Alternatively, this cooling signal could be related with the terminal terrane-amalgamation of the Central Asian Orogenic Belt. For the Kygyz Tianshan, late Jurassic–Cretaceous regional exhumation and Cenozoic fault reactivations can be linked with specific tectonic events during the closure of the Palaeo-Tethys and Neo-Tethys Oceans, respectively. The effect of the progressive consumption of these oceans and the associated collisions of Cimmeria and India with Eurasia probably only had a minor effect on the exhumation of the Siberian Altai-Sayan. More likely, tectonic forces from the east (present-day coordinates as a result of the building and collapse of the Mongol-Okhotsk orogen and rifting in the Baikal region shaped the current Siberian Altai-Sayan topography. Although many of these hypothesised links need to be tested further, they allow a first-order insight into the dynamic response and the stress propagation pathways from the Eurasian margin into the continental interior.

  20. Study of Siberian forest genetic resources

    Directory of Open Access Journals (Sweden)

    L. I. Milyutin

    2016-06-01

    Full Text Available Forest genetic resources are the aggregate of genofonds of native and cultivar populations of forest woody plants, valuable really or potential for specific territory (A brief dictionary… 2014. Forest genetic resources are studied in practice in most cases on example of forest-forming woody plants. It is necessary to consider of study of these resources in two positions: taxonomic and geographic. Forest forming coniferous species are studied best of all from the taxonomic point of view taking into account biodiversity. Genetic polymorphism is studied most in detail with such species as Pinus sylvestris, Pinus sibirica, Larix sibirica, Larix sukaczevii, Picea obovata, Abies sibirica. Populations of Larix gmelinii, Larix cajanderi, Picea ajanensis are studied considerable worse. Materials about genetic polymorphism of forest forming foliage species – representative of genera Betula and Populus are absent. Caryological polymorphism is studied sufficiently well in all Siberian conifer species. It should be noted especially attached to examination of this problem, that individuals with B-chromosome were discovered first by gymnosperms as an example Picea obovata. Discovery in Siberia of triploid asp deserve special attention. Geographic variability is shown most broadly in the investigations of Pinus sylvestris, Pinus sibirica, Larix sibirica. These investigations were conducted both in natural populations and in provenance trials. Such investigations of another conifer and foliage species either are shown by separate fragments or are absent at all Geographic variability is shown in a large measure in the operative forest seed sources regionalization. Numerous investigations directed to the analysis of morphological variability are conducted by all forest forming species in the first place by conifers. Questions of hereditary determination of either signs remain in this problem. Similar questions concern the variability of other signs

  1. Paleoproterozoic postcollisional magmatic belt of the southern Siberian craton

    Science.gov (United States)

    Salnikova, E. B.; Larin, A. M.; Kotov, A. B.; Levitsky, V. I.; Reznitsky, L. Z.; Kovach, V. P.; Yakovleva, S. Z.

    2003-04-01

    Paleoproterozoic time is characterized by large-scale collisional and postcollisional magmatic activity evidenced in the most of ancient cratons. This global event is related to the Arctic supercontinent assemblage (Rogers, 1996). The formation of postcollisional magmatic belt at 1.9-1.8 Ga within the south-west flanking of the Siberian craton is a remarkable example of these processes happened during overall lithospheric convergence. This belt is extends for about 3000 km from the southern Enisey ridge at the west to the central Aldan shield at the east. Within the central Aldan shield the latest collisional event occurred 1925+/-5 Ma (Kotov et al, 2003) and post-collisional subalkaline S- and I-type granites emplaced at 1916+/-10 Ma (Bibikova et al., 1989), 1901+/-1 Ma (Frost et al., 1998) and 1899+/-6 Ma (Kotov et al, 2003). However at the southern Olekma terrain (western Aldan shield) the syncollisional granites have formed at 1906+/-4 Ma and postcollisional Kodar granitoids were generated at 1876-1873 Ma (Larin et al., 2000). The is a tendency outlined in timing of postcollision processes to the west (in modern coordinates). Ages of postcollisional Kevakta granitoid plutons (1846+/-8 Ma) and volcanics of North-Baikal volcano-plutonic belt (1869+/-6 Ma 1856+/-3 Ma), Baikal folded area, support this tendency. Emplacement of the Primorsky complex postcollisional rapakivi-type granitoids (southern Baikal lake) occurred at 1859+/-16 Ma (Donskaya et al., 2002). New results of U-Pb single zircon and baddeleyite dating demonstrate that formation of late-synkinematic syenite, charnockite and pegmatitic veins (1856±12 Ma, 1853±20 Ma) and calciphyre (1868±2 Ma) within the eastern part of the Sharyzhalgay block (southern Baikal lake) occurred virtually within the same episode. Postcollisional intrusive charnockite of the Shumikha complex from the western Sharyzhalgay block dated at 1861±1 Ma (Donskaya et al., 2001) and 1871±17 Ma (Levitsky et al., 2002). Subalcaline

  2. Green synthesis of multifunctional silver and gold nanoparticles from the oriental herbal adaptogen: Siberian ginseng

    National Research Council Canada - National Science Library

    Abbai R; Mathiyalagan R; Markus J; Kim YJ; Wang C; Singh P; Ahn S; Farh ME; Yang DC

    2016-01-01

    ... *These authors contributed equally to this work Abstract: Pharmacologically active stem of the oriental herbal adaptogen, Siberian ginseng, was employed for the ecofriendly synthesis of Siberian ginseng silver nanoparticles (Sg-AgNPs...

  3. Wildfires Dynamics in Siberian Larch Forests

    Science.gov (United States)

    Ponomarev, Evgenii I.; Kharuk, Viacheslav I.; Ranson, Kenneth J.

    2016-01-01

    Wildfire number and burned area temporal dynamics within all of Siberia and along a south-north transect in central Siberia (45deg-73degN) were studied based on NOAA/AVHRR (National Oceanic and Atmospheric Administration/ Advanced Very High Resolution Radiometer) and Terra/MODIS (Moderate Resolution Imaging Spectroradiometer) data and field measurements for the period 1996-2015. In addition, fire return interval (FRI) along the south-north transect was analyzed. Both the number of forest fires and the size of the burned area increased during recent decades (p forest fires, burned areas and air temperature (r = 0.5) and drought index (The Standardized Precipitation Evapotranspiration Index, SPEI) (r = 0.43). Within larch stands along the transect, wildfire frequency was strongly correlated with incoming solar radiation (r = 0.91). Fire danger period length decreased linearly from south to north along the transect. Fire return interval increased from 80 years at 62 N to 200 years at the Arctic Circle (6633' N), and to about 300 years near the northern limit of closed forest stands (about 71+ N). That increase was negatively correlated with incoming solar radiation (r = 0.95). Keywords: wildfires; drought index; larch stands; fire return interval; fire frequency; burned area; climate-induced trends in Siberian wildfires

  4. Pyometra in a Siberian Polecat (Mustela eversmanni)

    Science.gov (United States)

    Johnson, J.D.; Biggins, D.E.; Wrigley, R.H.; Mangone, B.A.; Wimsatt, J.

    1999-01-01

    A 2-year-old Siberian polecat (Mustela eversmanni) from a breeding colony presented for ultrasound evaluation for pregnancy. It was paired with a male for 2.75 months and had remained absent of pregnancy signs when it was anesthetized and clinically evaluated. Until this time, the animal had eaten well and shown no outward signs of debility. On palpation, the animal had a fluid-filled tubular structure in the caudal abdomen, consistent in location and size with the uterus. No sign of vaginal discharge was present. Ultrasonography revealed 10 fluid-filled evaginations (approximately 12 mm in diameter) of the uterine horns. A presumptive diagnosis of a fluid-filled reproductive tract and likely reproductive failure was made in light of the animal's history, its clinical signs, and the ultrasound findings. Euthanasia was performed because the animal was nonreproductive and might yield information relevant to the breeding colony as a whole. Necropsy of the polecat revealed a distended fluctuant uterus containing mildly odiferous, thick, yellow-green, purulent material. Histopathology confirmed the diagnosis of pyometra. A pure and heavy growth of Enterococcus fecalis was cultured from the uterine contents. In light of results from routine minimal inhibitory concentration antibiotic sensitivity screening, this isolate was resistant to all antibiotics tested in the standard teaching hospital screen.

  5. Uveodermatologic Syndrome in a Siberian Husky: Clinical and Histopathological Findings

    Directory of Open Access Journals (Sweden)

    Min-Hee Kang

    2014-01-01

    Full Text Available A 2-year-old, intact male Siberian Husky was presented with corneal opacity, eye lid swelling, depigmentation, alopecia and erythema predominantly on face. Bilateral uveitis preceded periocular and nasal planum depigmentation. Ancillary tests excluded other systemic diseases. Histopathology of the skin revealed lichenoid interface dermatitis with pigmentary incontinence. Diffuse pyogranulomatous inflammation of the globes was also noted. Based on the clinical signs and characteristic histopathological findings, the dog was diagnosed as uveodermatologic syndrome (UDS. Further treatment was not attempted in this case and the dog was euthanized. This case report describes typical clinical and histopathologic features of UDS in a Siberian Husky.

  6. Variability of needle structure in Siberian stone pine in provenance plantations

    Directory of Open Access Journals (Sweden)

    O. Bender

    2013-12-01

    Full Text Available Siberian stone pine (Pinus sibirica Du Tour is one of the most common trees in Siberia. Its natural range is from the Ural Mountains to the Aldan river and from the Arctic Circle to northern Mongolia. The climate in natural Siberian stone pine sites influences the whole plant organism, particularly its needle structure, and the response to thisoccurs at specific morphological and anatomical levels. The genotypical and environmental effects on needle structure in different Siberianstone pine ecotypes are very little known. One effective way to examine and to separate genotypical effects from environmental ones is byusing a common garden experiment. The purpose is to analyze morphological and anatomical needle variability in Siberian stone pinemarginal populations that have been grown in provenance plantations in southern West Siberia, Russia. The needle samples were collectedin the provenance plantation located 30 km south of Tomsk (the southeastern West Siberian Plain, southern limit of the taiga zone,optimum site conditions for Siberian stone pine. We investigated the grafts of mother trees taken from natural sites. Four ecotypeswere selected for the study. Three ecotypes originated from northern (Urengoy, western (Neviyansk, and eastern (Severobaikalskmarginal populations. The fourth, the Tomsk ecotype, was a local control. The local Tomsk ecotype grows on a site where natural conditions are worse due to reduction of mean annual temperature and increase of the humid factor northward, humidity reduction eastward and its rise westward. Variability of 10 needle morphologicaland anatomical characteristics was studied. The northern ecotype had smaller needle length (28%, leaf cross-section area (21%, mesophyll area (29%, mesophyll cell size (27%, and conducting bundle area (16% but the number of stomata per unit leaf area increased by 16% over the local Tomsk ecotype. The resin canal area, epidermal andhypodermal

  7. Numerical optimization of Siberian snakes and spin rotators for RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Luccio, A.U.

    1995-12-31

    The structure of the four Siberian Snakes and eight Spin Rotators being designed for RHIC is discussed. These devices consist each of four helical dipoles. Results of orbit and spin tracking through the magnets are presented. 14 refs., 8 figs., 4 tabs.

  8. Volatile Release From The Siberian Traps Inferred From Melt Inclusions

    Science.gov (United States)

    Black, Benjamin A.; Elkins-Tanton, Linda T.; Rowe, Michael C.; Ukstins Peate, Ingrid

    2010-05-01

    The Siberian Traps Large Igneous Province is one of the largest known continental flood volcanic provinces in the Phanerozoic. The quantification of volatile degassing is particularly important because the Siberian Traps have often been invoked as a possible trigger for the end-Permian mass extinction (e.g. Campbell et al., 1992; Wignall, 2001). Volatile degassing provides a crucial mechanism to link mafic volcanic eruption with global environmental change. Mafic flood basalt magmas are expected to have low volatile contents (similar to mid-ocean ridge basalts). However, Siberian Traps magmas were chambered in and erupted through a thick sedimentary basin and may have interacted with, and obtained volatiles from, sedimentary lithologies such as limestone, coal, and evaporite. Melt inclusions from the Siberian Traps provide insight into the potential total volatile budget throughout the evolution of the large igneous province. These droplets of trapped melt may preserve volatile species that would otherwise have degassed at the time of eruption. We present data from the analysis of more than 100 melt inclusions, including both homogenized inclusions and rare glassy inclusions with low crystallinity. Many melt inclusions from tuffs and flows near the base of the Siberian Traps sequence are substantially enriched in chlorine and fluorine compared to Deccan Traps and Laki melt inclusions (Self et al., 2008; Thordarson et al., 1996). These inclusions record chlorine concentrations up to ~1400 ppm, and fluorine concentrations up to ~5000 ppm. Olivines from the Maymechinsky suite, recognized as the last extrusive products of Siberian Traps volcanism, contain melt inclusions with maximum sulfur concentrations in the range of ~5000 ppm and substantial concentrations of chlorine. Intrusive igneous rocks from the province also display significant volatile contents. A sill from the Ust-Ilimsk region yielded plagioclase-hosted melt inclusions which contain chlorine and fluorine

  9. Hydrological modelling for siberian crane Grus Leucogeranus stopover sites in northeast China.

    Science.gov (United States)

    Jiang, Haibo; He, Chunguang; Sheng, Lianxi; Tang, Zhanhui; Wen, Yang; Yan, Tingting; Zou, Changlin

    2015-01-01

    Habitat loss is one of the key factors underlying the decline of many waterbird species, including Siberian Crane (Grus leucogeranus), a threatened species worldwide. Wetlands are the primary stopover for many waterbirds and restoration of these wetlands involves both hydrological restoration and water resource management. To protect the stopover sites of Siberian Cranes, we collected Siberian Crane stopover numbers, meteorological and hydrological data, and remote sensing data from 2008 to 2011 in Momoge National Nature Reserve, one of the largest wetlands in northeastern China. A model was developed to estimate the suitability of Siberian Crane stopover sites. According to our results, the most suitable daily water level for Siberian Cranes between 2008 and 2012 occurred in the spring of 2008 and in the Scirpus planiculmis growing season and autumn of 2010. We suggest a season-dependent water management strategy in order to provide suitable conditions at Siberian Crane stopover sites.

  10. Hydrological modelling for siberian crane Grus Leucogeranus stopover sites in northeast China.

    Directory of Open Access Journals (Sweden)

    Haibo Jiang

    Full Text Available Habitat loss is one of the key factors underlying the decline of many waterbird species, including Siberian Crane (Grus leucogeranus, a threatened species worldwide. Wetlands are the primary stopover for many waterbirds and restoration of these wetlands involves both hydrological restoration and water resource management. To protect the stopover sites of Siberian Cranes, we collected Siberian Crane stopover numbers, meteorological and hydrological data, and remote sensing data from 2008 to 2011 in Momoge National Nature Reserve, one of the largest wetlands in northeastern China. A model was developed to estimate the suitability of Siberian Crane stopover sites. According to our results, the most suitable daily water level for Siberian Cranes between 2008 and 2012 occurred in the spring of 2008 and in the Scirpus planiculmis growing season and autumn of 2010. We suggest a season-dependent water management strategy in order to provide suitable conditions at Siberian Crane stopover sites.

  11. Dyke belt in North Western margin of Siberian platform

    Science.gov (United States)

    Ryabov, Victor

    2015-04-01

    The Early Triassic dyke swarm belt is strengthening at about 500 km (50-60 km width) along the northern margin of Siberian platform. Its locations is limited from the north by rift structure of the Yenisei-Khatanga trough, and from the south by Kystyktah-Ayan-Ambardah uprise. From west to east dyke belt is crossing Norilsk, Kamensky and Maimecha-Kotuiskaya province. In this direction the composition of dykes changing from basic rthrough alkali-basic to alkali-ultramafic varieties. The sickness of dykes varies from 0,5-10m up to 90 m and length - from 5-15 m to 140 km. The orientation of the bulk of dykes coincides with the direction of the major structural and tectonic lineaments of the region. Dykes are often refer to the fault planes. The composition of dykes may vary along the stretches. The density of hundreds of basaltic dykes and small intrusions in the dyke swarms is not permanent and sometimes essentially uneven. They form a compact dyke swarms of dykes, stocks and sub layering bodies veins. In dyke package on Huor-Uyallah river here are 20 subparallel dykes of different chemical composition at a distance of 2 km Lack of the evidence of the dykes crossing allows to assume their formation during the same magmatic cycle. Dykes cross cut through the entire incision of basaltic plateau. They did not created the flow effusions and refer to the final stage trap magmatism. Ar/Ar age of the youngest dykes in the province Kamenska 238-247 Ma. the age of lamproite dyke in Norilsk province is 235 Ma. Dykes are represented by dolerites trachydolerites, syenites, minettes, lamprophyres (camptonite, spessartite, vosgesite), avgitites, melanephelinite, alnoites, limburgites alkaline picrites, meimechites. Their content vary widely: SiO2 - 35,7-62,6; TiO2- 0,4-7,5; Al2O3- 4,4-17,5; Fe2O3- 4,6-20,6; MnO- 0,08-0,44; MgO- 0,8-31,5; CaO- 0,7-15,4; Na2O- 0,01-6,5; K2O 0,8-5,3 wt.%; P2O5 0,1-1,2 wt.%. The h Bolsheavamskaya volcanic basin in Kamensky province is most abundant in

  12. Overcoming Depolarizing Resonances with Dual Helical Partial Siberian Snakes

    Science.gov (United States)

    Huang, H.; Ahrens, L. A.; Bai, M.; Brown, K.; Courant, E. D.; Gardner, C.; Glenn, J. W.; Lin, F.; Luccio, A. U.; Mackay, W. W.; Okamura, M.; Ptitsyn, V.; Roser, T.; Takano, J.; Tepikian, S.; Tsoupas, N.; Zelenski, A.; Zeno, K.

    2007-10-01

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is challenging. In a medium energy accelerator, the depolarizing spin resonances are strong enough to cause significant polarization loss but full Siberian snakes cause intolerably large orbit excursions and are also not feasible since straight sections usually are too short. Recently, two helical partial Siberian snakes with double pitch design have been installed in the Brookhaven Alternating Gradient Synchrotron (AGS). With a careful setup of optics at injection and along the energy ramp, this combination can eliminate the intrinsic and imperfection depolarizing resonances otherwise encountered during acceleration to maintain a high intensity polarized beam in medium energy synchrotrons. The observation of partial snake resonances of higher than second order will also be described.

  13. Overcoming depolarizing resonances with dual helical partial Siberian snakes.

    Science.gov (United States)

    Huang, H; Ahrens, L A; Bai, M; Brown, K; Courant, E D; Gardner, C; Glenn, J W; Lin, F; Luccio, A U; Mackay, W W; Okamura, M; Ptitsyn, V; Roser, T; Takano, J; Tepikian, S; Tsoupas, N; Zelenski, A; Zeno, K

    2007-10-12

    Acceleration of polarized protons in the energy range of 5 to 25 GeV is challenging. In a medium energy accelerator, the depolarizing spin resonances are strong enough to cause significant polarization loss but full Siberian snakes cause intolerably large orbit excursions and are also not feasible since straight sections usually are too short. Recently, two helical partial Siberian snakes with double pitch design have been installed in the Brookhaven Alternating Gradient Synchrotron (AGS). With a careful setup of optics at injection and along the energy ramp, this combination can eliminate the intrinsic and imperfection depolarizing resonances otherwise encountered during acceleration to maintain a high intensity polarized beam in medium energy synchrotrons. The observation of partial snake resonances of higher than second order will also be described.

  14. Circadian rhythms of photorefractory siberian hamsters remain responsive to melatonin.

    Science.gov (United States)

    Butler, Matthew P; Paul, Matthew J; Turner, Kevin W; Park, Jin Ho; Driscoll, Joseph R; Kriegsfeld, Lance J; Zucker, Irving

    2008-04-01

    Short day lengths increase the duration of nocturnal melatonin (Mel) secretion, which induces the winter phenotype in Siberian hamsters. After several months of continued exposure to short days, hamsters spontaneously revert to the spring-summer phenotype. This transition has been attributed to the development of refractoriness of Mel-binding tissues, including the suprachiasmatic nucleus (SCN), to long-duration Mel signals. The SCN of Siberian hamsters is required for the seasonal response to winter-like Mel signals, and becomes refractory to previously effective long-duration Mel signals restricted to this area. Acute Mel treatment phase shifts circadian locomotor rhythms of photosensitive Siberian hamsters, presumably by affecting circadian oscillators in the SCN. We tested whether seasonal refractoriness of the SCN to long-duration Mel signals also renders the circadian system of Siberian hamsters unresponsive to Mel. Males manifesting free-running circadian rhythms in constant dim red light were injected with Mel or vehicle for 5 days on a 23.5-h T-cycle beginning at circadian time 10. Mel injections caused significantly larger phase advances in activity onset than did the saline vehicle, but the magnitude of phase shifts to Mel did not differ between photorefractory and photosensitive hamsters. Similarly, when entrained to a 16-h light/8-h dark photocycle, photorefractory and photosensitive hamsters did not differ in their response to Mel injected 4 h before the onset of the dark phase. Activity onset in Mel-injected hamsters was masked by light but was revealed to be significantly earlier than in vehicle-injected hamsters upon transfer to constant dim red light. The acute effects of melatonin on circadian behavioral rhythms are preserved in photorefractory hamsters.

  15. ACCELERATING AND COLLIDING POLARIZED PROTONS IN RHIC WITH SIBERIAN SNAKES.

    Energy Technology Data Exchange (ETDEWEB)

    ROSER,T.; AHRENS,L.; ALESSI,J.; BAI,M.; BEEBE - WANG,J.; BRENNAN,J.M.; BROWN,K.A.; BUNCE,G.; CAMERON,P.; COURANT,E.D.; DREES,A.; FISCHER,W.; ET AL

    2002-06-02

    We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180{sup o} about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV. We report on our experiences during commissioning and operation of collider with polarized protons.

  16. Paleoproterozoic, High-Metamorphic, Metasedimentary Units of Siberian Craton

    Institute of Scientific and Technical Information of China (English)

    Lena URMANTSEVA; Olga TURKINA

    2009-01-01

    Sensitive, high-resointion ion microprobe zircon U-Pb ages of Paleoproterozoic, high-grade,metasedimentary rocks from the south-western part of the Siberian Craton are reported. Early Precambrian, high-grade complexes, including garnet-biotite, hypersthene-biotite, and cordierite-bearing gneisses compose the Irkut terrane of the Sharyzhalgay Uplift. Protoliths of studied gneisses correspond to terrigenous sediments, ranging from greywacke to shale. The paragneiss model Nd ages of 2.4-3.1 Ga indicate Archean-to-Paleoproterozoic source provinces. Zircons from gneisses show core-rim textures in cathodoluminescence (CL) image. Round or irregular shaped cores indicate detrital origin. Structureless rims with low Th/U are metamorphic in origin. The three age groups of detrital cores are: ≥2.7, -2.3, and 1.95-2 Ga. The ages of metamorphic rims range from 1.86 to 1.85 Ga;therefore, the sediments were deposited between 1.95 and 1.86 Ga and derived from Archean and Paleoproterozoic source rocks. It should be noted that Paleoproterozoic metasedimentary rocks of the Irkut Block are not unique. High-grade metaterrigenons sediments, with model Nd ages ranging from 2.3 to 2.5 Ga, are widely distributed within the AIdan and Anabar Shields of the Siberian Craton. The same situation is observed in the North China Craton, where metasedimentary rocks contain detrital igneous zircon grains with ages ranging from 3 to 2.1 Ga (Wan et al., 2006). All of these sedimentary units were subjected to Late Paleoproterozoic metamorphism. In the Siberian Craton, the Paleoproterozoic sedimentary deposits are possibly marked passive margins of the Early Precambrian crustal blocks, and their high-grade metamorphism was related to the consolidation of the Siberian Craton.

  17. Vertical plate motions in the West Siberian Basin

    Science.gov (United States)

    Vibe, Yulia

    2014-05-01

    The West Siberian Basin is a sedimentary basin situated between the Ural Mountains and the Siberian Craton. The Basin has experienced several periods of subsidence and uplift since the arrival of the Siberian Traps c. 250 Ma. Although the Basin is extensively explored and hosts large reserves of Oil and Gas, the forces driving the vertical motions are poorly understood. In this work we attempt to analyse the amount, timing and location of subsidence and uplift in the Basin to shed light on the possible causes of these motions. A detailed description of sedimentary layers is published in a number of Soviet-era books and articles and serves as a basis for our research. This data is first converted into sediment grids through time. Subsequently, the sediments, the sediment load and the compaction are taken into account ('backstripping') to produce the depth of the Basin at respective time steps. With this technique we calculate the tectonic component of subsidence. Uncertainties related to uplift events are estimated by the unconformities in the stratigraphic charts. One of the possible driving forces of vertical motions is a change of force balance arising at plate boundaries. Since active plate tectonics have been absent from West Siberia since the formation of the Urengoy and Khodosey Rifts, c. 250Ma, we study the far-field tectonic effects as a potential driving mechanism. Indeed, some of the significant vertical events in the West Siberian Basin coincide with the major tectonic events around Siberia. An example is the spreading in the Arctic (Eurasian Basin) in the Eocene (56 Ma) which was synchronous with initiation of uplift events in the northern part of West Siberia. In the middle Oligocene (33 Ma), the northern and eastern parts of the basin were subjected to uplift as subsidence migrated southwards and the Basin rose above the sea level. This was coincident with the changes of plate motions in the northern North Atlantic and Indo-European collision.

  18. Triumph of Technology Over Geography - Unlocking the Siberian Maritime Icebox,

    Science.gov (United States)

    1987-05-22

    submersible support hold) Zakarpatye 3 3 Leskov 10 10 Juniper S S Bertolt Brecht 4 4 Walter Dehmel 6 6 Super Atlantik - *3,000 Tn 178 178 Vityaz 2 2...engineering support for a fleet of eighteen Coast Guard towboats on the Mississippi River emphasized in my mind the vital role rivers must play In a...and along the corridor between the Siberian industrial centers of Sverdlovsk and Chita.( 1 7) All-terrain vehicles are playing increasingly important

  19. The Siberian Stone Pine Stands Near Settlements in Tomsk Region. Problems of Sustainable Forest Use

    Directory of Open Access Journals (Sweden)

    N. M. Debkov

    2014-06-01

    Full Text Available A review of the Siberian stone pine stands' formation near settlements in Tomsk region is given in historical aspect. Their current status is described in detail. Age, tree species, and typological structure, as well as productivity and dynamics of forest inventory indices have been identified. Forest management practices in leased and non-leased Siberian stone pine stands have been analyzed. The ways and procedures for an expansion of the existing Siberian stone pine stands and creation of new Siberian stone pine forests near settlements is proposed.

  20. Helical dipole partial Siberian snake for the AGS

    Energy Technology Data Exchange (ETDEWEB)

    Takano, J [RIKEN, Saitama, (Japan); Ahrens, L A [Brookhaven National Laboratory, Upton, NY 11973 (United States); Alforque, R [Brookhaven National Laboratory, Upton, NY 11973 (United States); Bai, M [Brookhaven National Laboratory, Upton, NY 11973 (United States); Brown, K [Brookhaven National Laboratory, Upton, NY 11973 (United States); Courant, E D [Brookhaven National Laboratory, Upton, NY 11973 (United States); Ganetis, G [Brookhaven National Laboratory, Upton, NY 11973 (United States); Gardner, C J [Brookhaven National Laboratory, Upton, NY 11973 (United States); Glenn, J W [Brookhaven National Laboratory, Upton, NY 11973 (United States); Hattori, T [Tokyo Institute of Technology, Tokyo, (Japan); Huang, H [Brookhaven National Laboratory, Upton, NY 11973 (United States); Jain, A [Brookhaven National Laboratory, Upton, NY 11973 (United States); Luccio, A U [Brookhaven National Laboratory, Upton, NY 11973 (United States); MacKay, W W [Brookhaven National Laboratory, Upton, NY 11973 (United States); Okamura, M [Brookhaven National Laboratory, Upton, NY 11973 (United States); Roser, T [Brookhaven National Laboratory, Upton, NY 11973 (United States); Tsoupas, N [Brookhaven National Laboratory, Upton, NY 11973 (United States); Tepikian, S [Brookhaven National Laboratory, Upton, NY 11973 (United States); Tuozzolo, J [Brookhaven National Laboratory, Upton, NY 11973 (United States); Wood, J [Brookhaven National Laboratory, Upton, NY 11973 (United States); Zelenski, A [Brookhaven National Laboratory, Upton, NY 11973 (United States); Zeno, K [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2006-11-15

    Overcoming depolarization resonances in medium class synchrotrons (3 to 50 GeV) is one of the key issues in accelerating a highly polarized proton beam up to very high energies. Since such synchrotrons, including the Alternating Gradient Synchrotron (AGS) and the J-PARC Main Ring, generally do not have sufficiently long straight sections to accommodate full Siberian snakes with reasonable beam excursions, the practical solution is to use partial Siberian snakes that rotate the particle spin about a horizontal axis by a fraction of 180 degrees. For the AGS, we designed and installed a new partial Siberian snake consisting of a helical dipole magnet with a double pitch structure. The helical structure reduced the amount of transverse coupling as compared to that achieved by the previous solenoidal partial snake. This coupling led to partial depolarization at certain energies from horizontal betatron oscillations. The helical magnetic field in the snake magnet was calculated using a 3D magnetic field code TOSCA, and was optimized by segmenting the helical pitch and varying the lengths of the segments. Fabrication errors were checked and verified to be within required tolerances. Finally, the transverse field was measured by rotating harmonic coils. After installation, we achieved a 37.5% improvement in polarization - from 40% with the old solenoid to 55% with the new helical snake, thereby demonstrating that the helical partial snake is an effective device to suppress depolarization resonances in medium-sized synchrotrons.

  1. Helical dipole partial Siberian snake for the AGS

    Science.gov (United States)

    Takano, J.; Ahrens, L. A.; Alforque, R.; Bai, M.; Brown, K.; Courant, E. D.; Ganetis, G.; Gardner, C. J.; Glenn, J. W.; Hattori, T.; Huang, H.; Jain, A.; Luccio, A. U.; MacKay, W. W.; Okamura, M.; Roser, T.; Tsoupas, N.; Tepikian, S.; Tuozzolo, J.; Wood, J.; Zelenski, A.; Zeno, K.

    2006-11-01

    Overcoming depolarization resonances in medium class synchrotrons (3 to 50 GeV) is one of the key issues in accelerating a highly polarized proton beam up to very high energies. Since such synchrotrons, including the Alternating Gradient Synchrotron (AGS) and the J-PARC Main Ring, generally do not have sufficiently long straight sections to accommodate full Siberian snakes with reasonable beam excursions, the practical solution is to use partial Siberian snakes that rotate the particle spin about a horizontal axis by a fraction of 180 degrees. For the AGS, we designed and installed a new partial Siberian snake consisting of a helical dipole magnet with a double pitch structure. The helical structure reduced the amount of transverse coupling as compared to that achieved by the previous solenoidal partial snake. This coupling led to partial depolarization at certain energies from horizontal betatron oscillations. The helical magnetic field in the snake magnet was calculated using a 3D magnetic field code TOSCA, and was optimized by segmenting the helical pitch and varying the lengths of the segments. Fabrication errors were checked and verified to be within required tolerances. Finally, the transverse field was measured by rotating harmonic coils. After installation, we achieved a 37.5% improvement in polarization - from 40% with the old solenoid to 55% with the new helical snake, thereby demonstrating that the helical partial snake is an effective device to suppress depolarization resonances in medium-sized synchrotrons.

  2. Chemical characteristics of Siberian boreal forest fire emissions

    Science.gov (United States)

    Engling, G.; Popovicheva, O.; Fan, T. S.; Eleftheriadis, K.; Diapouli, E.; Kozlov, V.

    2014-12-01

    Smoke emissions from Siberian boreal forest fires exert critical impacts on the aerosol/climate system of subarctic regions and the Arctic. It is, therefore, crucial to assess the ability of such particles to absorb/scatter incoming solar radiation as well as act as cloud condensation nuclei, which is closely linked to the physical and chemical aerosol properties. However, observations of Siberian wildfire emissions are limited, and no systematic database of smoke particle properties is available for this region to date. As part of this study, ambient aerosol samples were collected during two smoke episodes in Tomsk, Siberia, in the summers of 2012 and 2013. In addition, the chemical composition and optical properties of smoke particles derived from the combustion of typical Siberian fuels, including pine wood and debris, were determined during chamber burn experiments in a large aerosol/combustion chamber under controlled combustion conditions representative of wildfires and prescribed burns. Detailed multi-component characterization of individual particles and bulk properties was accomplished with a suite of techniques, including various types of chromatography, microscopy, spectroscopy, and thermo-optical analysis. Individual particle analysis by SEM-EDX combined with cluster analysis revealed characteristic smoke structural components and major types of particles, which allowed to discriminate between flaming and smoldering regimes, reflected in specific morphological and chemical microstructure. The physicochemical properties representing the combustion phase (smoldering versus flaming) and the degree of processing (fresh versus aged) were assessed in the ambient aerosol based on the chamber burn results. For instance, some chemical transformation (aging of smoke particles) was noticed over a period of two days in the absence of sun light in the combustion chamber for certain chemical species, while the molecular tracer levoglucosan appeared to be rather

  3. THE SOUTHERN FRAGMENT OF THE SIBERIAN CRATON: “LANDSCAPE” HISTORY OVER TWO BILLION YEARS

    Directory of Open Access Journals (Sweden)

    Arkady M. Stanevich

    2015-09-01

    divergence events, which most probably occurred in the period of 1000–850 mln years in the east, and in the interval of 780–730 mln years in the west of the territory. The latest period is logically aligned with disintegration of Rodini, the super-continent. The period of 780–680 mln years in the eastern part of the region can defined by the beginning of convergency processes, formation and evolution of the island arc and the back-arc basin. It is supposed that basal layers of the Baikalskaya and Oselokskaya suites and their analogues occurred 730 mln years ago, and evidences of glacial processes in these series correlate with the global Sturtian glaciations. The period of 680–630 mln years was characterized by formation of the foreland-type peripheral basin which was then replaced by a system of orogen-type submontain troughs in the Early Vendian (from 630 mln years, see Fig. 3Г. The second half of the Vendian in various zones of SSC was distinguished by shallow-water carbonate-terrigenous sediments of a similar type. Compensatory sedimentation occurred in residual valleys of the basin. Fast infill of the basin and leveling of the relief resulted in the stationary regime of the relatively shallow, yet vast basin. In the Early Cambrian, carbonate sedimentation occurred throughout the Siberian Platform and in the area adjacent to the SSC (see Fig. 3Д.The Paleozoic sediments preserved mainly in the central and northern regions of the Siberian Platform reflect a complex evolution of internal and epicontinental seas and shallower basins of the Siberian continent named Angarida. In the Ordovician, predominating were carbonate rocks with marine fauna. In the Silurian was characterized by a variety of sediments formed in different marine environments, ranging from distal shelf to shallow water and salted gulfs. In the Late Silurian and the Early Devonian, the territory of Angarida was land. Local volcanism with mafic lava eruptions through fractures took place at the

  4. Analytical solutions for spin response functions in model storage rings with Siberian Snakes

    Energy Technology Data Exchange (ETDEWEB)

    Mane, S.R. [Convergent Computing Inc., P.O. Box 561, Shoreham, NY 11786 (United States)], E-mail: srmane@optonline.net

    2009-03-01

    I present analytical solutions for the spin response functions for radial field rf dipole spin flippers in models of storage rings with one Siberian Snake or two diametrically opposed orthogonal Siberian Snakes. The solutions can serve as benchmarks tests for computer programs. The spin response functions can be used to calculate the resonance strengths for radial field rf dipole spin flippers in storage rings.

  5. Factors Influencing Formation of the Siberian Stone Pine Stands Near Settlements in Northern Taiga

    Directory of Open Access Journals (Sweden)

    V. N. Sedykh

    2014-04-01

    Full Text Available The peculiarities of formation of seed productive Siberian stone pine stands near settlements, due to the total destruction of the living ground cover and forest litter, providing heat influx in the root-inhabited zone of the Siberian stone pine trees is discussed in the paper.

  6. The Chemistry of Cold: Mechanisms of Torpor Regulation in the Siberian Hamster.

    Science.gov (United States)

    Cubuk, Ceyda; Bank, Jonathan H H; Herwig, Annika

    2016-01-01

    Siberian hamsters use spontaneous daily torpor, a state of hypometabolism and hypothermia, to save energy during winter. Multiple neuroendocrine signals set the scene for spontaneous torpor to occur, and several brain areas have been identified as potential sites for torpor regulation. Here, we summarize the known mechanisms of a fascinating physiological state in the Siberian hamster.

  7. Some Contact Languages and Pidgin and Creole Languages in the Siberian Region.

    Science.gov (United States)

    Wurm, Stephen A.

    1992-01-01

    Discusses the role of Russian colonization of the Siberian region and the impact of demographic changes on languages in the region. Topics addressed include intercommunication through contact languages based on one-way bilingualism, pidgin and creole languages in the Siberian region, and Eskimo Pidgin. (33 references) (Author/JP)

  8. [Genetic passportization and identification of Siberian cranes (Grus leucogeranus Pallas) in captivity].

    Science.gov (United States)

    Mudrik, E A; Kashentseva, T A; Gamburg, E A; Politov, D V

    2014-01-01

    The genetic diversity of the founders of an artificial population of the Siberian crane Grus leucogeranus Pallas (rare species of cranes) was characterized using 10 microsatellite loci. It was established that the allelic diversity (on average, 5.9 alleles per locus) and genic (H(o) = 0.739) diversity of the Siberian crane is rather high and comparable with the estimations for natural populations of different crane species. Genetic passportization of the birds (119 individuals) from the register of the Siberian crane International Studbook was carried out at the initial stage. The efficiency of genetic passportization for individual identification, identification of the origin, paternity analysis, and exclusion of inbreeding was demonstrated in Siberian cranes under natural mating and artificial insemination. Cases of natural reproduction in pairs of Siberian cranes imprinted to the human and continuous storage of spermatozoa in the female reproductive ducts were registered.

  9. Fir Decline and Mortality in the Southern Siberian Mountains

    Science.gov (United States)

    Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Dvinskaya, Mariya, L.; Fedotova, Elena V.; Ranson, Kenneth J.

    2016-01-01

    Increased dieback and mortality of dark needle conifer (DNC) stands (composed of fir (Abies sibirica),Siberian pine (Pinus sibirica) and spruce (Picea obovata))were documented in Russia during recent decades. Here we analyzed spatial and temporal patterns of fir decline and mortality in the southern Siberian Mountains based on satellite, in situ and dendrochronological data. The studied stands are located within the boundary between DNC taiga to the north and forest-steppe to the south. Fir decline and mortality were observed to originate where topographic features contributed to maximal water-stress risk, i.e., steep (1825),convex, south-facing slopes with a shallow well-drained root zone. Fir regeneration survived droughts and increased stem radial growth, while upper canopy trees died. Tree ring width(TRW) growth negatively correlated with vapor pressure deficit (VPD), drought index and occurrence of late frosts, and positively with soil water content. Previous year growth conditions (i.e., drought index, VPD, soil water anomalies)have a high impact on current TRW (r 0.600.74). Fir mortality was induced by increased water stress and severe droughts (as a primary factor) in synergy with bark-beetles and fungi attacks (as secondary factors). Dendrochronology data indicated that fir mortality is a periodic process. In a future climate with increased aridity and drought frequency, fir (and Siberian pine) may disappear from portions of its current range (primarily within the boundary with the forest steppe)and is likely to be replaced by drought-tolerant species such as Pinus sylvestris and Larix sibirica.

  10. Torpor shortens the period of Siberian hamster circadian rhythms.

    Science.gov (United States)

    Thomas, E M; Jewett, M E; Zucker, I

    1993-10-01

    We investigated the influence of ambient and body temperature (Ta and Tb) on circadian rhythms of gonadectomized male Siberian hamsters. Animals that entered torpor (Tb circadian periods (tau s) than did nontorpid hamsters at a Ta of 13 degrees C (24.17 +/- 0.05 vs. 24.33 +/- 0.04 h). The tau s of homeothermic hamsters were not affected by Ta change. Short-term decreases in Tb, rather than changes in Ta, appear to affect tau. Access to activity wheels inhibited expression of torpor in short daylengths and was associated with significant increases in body mass. Running wheel activity can mask or block specific short-day responses.

  11. The Nature of Mantle Sources for Perm-Triassic Traps of Western Siberian Plate and Siberian Platform

    Science.gov (United States)

    Sharapov, V.; Perepechko, Y.; Rakhmenkulova, I.

    2007-12-01

    This work deals with the consistent dynamics for the development of melting zones due to convection in the upper mantle and the adjacent melting zones in inhomogeneous lithosphere. This model is studied for magma systems of Western Siberian Plate and Siberian Platform (SP). The results of numerical modeling allow us to conclude the following: 1. Structural and petrochemical zoning for Perm-Triassic trap magmatism of the Siberian Platform can be explained due to two-level melting of mantle rocks over hotspots (McKenzie, 1984). An alternative approach to explain mechanism of trap magmatism because of hydrodynamic evolution of magma under inhomogeneous lithosphere (King, Anderson, 1995) does not allow us to obtain voluminous melting of the mantle rocks for the lithosphere. 2. Main volumes of tholeiitic magmas (which compose both the intrusives in the SP platform cover and SP profiles of lava shield) are due to melting of mantle rocks in the thinned parts of the lithosphere over a number of spread hotspots. 3. The area of partial melting in the lithosphere is appearing after the zone of decompressing melting developed to its maximum extent, under the conditions of convection in the upper mantle. The melting zone appearing at the depth about 70-100 km has a plate-like shape, thickness up to ~20-30 km and horizontal extent coexistent with the sizes of the lava shield. This research was supported by the President's grants NSh-1573.2003.5, and by the Russian Ministry Science and Education grant RNP.2.1.1.702.

  12. Siberian Chemical Combine laboratory project work plan, fiscal year 1999

    Energy Technology Data Exchange (ETDEWEB)

    Morgado, R.E.; Acobyan, R.; Shropsire, R.

    1998-12-31

    The Siberian Chemical Combine (SKhK), Laboratory Project Work Plan (Plan) is intended to assist the US Laboratory Project Team, and Department of Energy (DOE) staff with the management of the FY99 joint material protection control and accounting program (MPC and A) for enhancing nuclear material safeguards within the Siberian Chemical Combine. The DOE/Russian/Newly Independent States, Nuclear Material Task Force, uses a project work plan document for higher-level program management. The SKhK Plan is a component of the Russian Defense related Sites` input to that document. In addition, it contains task descriptions and a Gantt Chart covering the FY99 time-period. This FY99 window is part of a comprehensive, Project Status Gantt Chart for tasking and goal setting that extends to the year 2003. Secondary and tertiary levels of detail are incorporated therein and are for the use of laboratory project management. The SKhK Plan is a working document, and additions and modifications will be incorporated as the MPC and A project for SKhK evolves.

  13. Biodiversity and endemism of the Silurian vertebrates in the Siberian palaeocraton

    Science.gov (United States)

    Žigaitä-, Živilä--

    2010-05-01

    Vertebrate fossil record in the Silurian successions of northwestern Mongolia, Tuva, central and southern parts of the East Siberia between Yenisey and Lena rivers (Siberian platform) comprises large diversity of endemic fish species and genera. All this present day terrirories are infered to have been existed as united Siberian palaeocraton, an independent geological terrane in the Palaeozoic. Comparative isolation of the Siberian palaeocontinent throughout the Palaeozoic also meant that the area was colonised by marine faunas, which are not found elsewhere on Earth (Cocks & Torsvik, 2007). A separate palaeobiogeographical province has been suggested, and can be confirmed by the abundance, content, and distribution of early fish. Majority of vertebrate groups, such as thelodonts and acanthodians, reported from the region (Karatajūtė-Talimaa, 1978; Karatajūtė-Talimaa & Smith, 2003; Žigaitė, in press) are diverse, abundant and restricted to the province, showing palaeobiogeographical unity of the territory. Distinct in their taxonomic content, but less common are chondrichthyans (Žigaitė & Karatajūtė-Talimaa, 2008). Finally, the most peculiar types of early vertebrates as mongolepids, tesakoviaspids, and tesserated galeaspids (Afanasieva & Janvier, 1985; Karatajūtė-Talimaa et al., 1990; Karatajūtė-Talimaa & Smith, 2004; Karatajūtė-Talimaa & Žigaitė, 2005), also specific heterostracans refer the region to strong faunal endemism and favours consideration of the separate palaeobiogeographical province. The biodiversity of vertebrates indicates warm and productive palaeobasins, which most likely have been existed as well connected epeiric seas on the integral Siberian palaeocraton. It might have been a proper place for origin and radiation of at least some early vertebrates in the Silurian (Žigaitė & Blieck, 2006). Nevertheless, recent palaeogeographical studies place Siberia at high northern latitudes, inferring the inherent endemic brachiopod

  14. Power Scaling and Seasonal Changes of Floe Areas in the Arctic East Siberian Sea

    Science.gov (United States)

    Geise, Gregory R.; Barton, Christopher C.; Tebbens, Sarah F.

    2017-01-01

    The cumulative number versus floe area distribution of seasonal sea floes from six satellite images of the Arctic Ocean during the summer breakup and melting is fit by two scale-invariant power law scaling regimes for floe areas ranging from 30 to 28,400,000 m2. Scaling exponents, β, for larger floe areas range from -0.6 to -1.0 with an average of -0.8. Scaling exponents, β, for smaller floe areas range from -0.3 to -0.6 with an average of -0.5. The inflection point between the two scaling regimes ranges from 283 × 102 to 4850 × 102 m2 and generally moves from larger to smaller floe areas through the summer melting season. The stability of the power scaling results is demonstrated for two of the images by dividing each in half and analyzing each half separately, with the result that the scaling exponents and the size of the inflection points are nearly the same for each half as for the whole image. We propose that the two scaling regimes and the inflection between them are established during the initial breakup of sea ice solely by the process of fracture. The distributions of floe size regimes retain their scaling exponents as the floe pack evolves from larger to smaller floe areas from the initial breakup through the summer season, due to grinding, crushing, fracture, and melting. The scaling exponents for floe area distribution are in the same range as those reported in previous studies of Arctic floes and for the single scaling exponents found for crushed and ground geologic materials including streambed gravel, lunar debris, and artificially crushed quartz. The single scaling exponent found for fault gouge falls below the range for floes possibly because the fracturing and grinding process in fault gouge takes place under high confining pressure. A probabilistic model of fragmentation is proposed that generates a single power law scaling distribution of fragment size.

  15. Sources and characteristics of terrestrial carbon in Holocene-scale sediments of the East Siberian Sea

    DEFF Research Database (Denmark)

    Keskitalo, K.; Tesi, T.; Bröder, L.

    2017-01-01

    Thawing of permafrost carbon (PF-C) due to climate warming can remobilise considerable amounts of terrestrial carbon from its long term storage to the marine environment. PF-C can be then buried in sediments or remineralised to CO2 with implications for the carbon-climate feedback. Studying histo...

  16. Historical records of organic matter supply and degradation status in the East Siberian Sea

    DEFF Research Database (Denmark)

    Bröder, Lisa; Tesi, Tommaso; Andersson, August

    2016-01-01

    Destabilization and degradation of permafrost carbon in the Arctic regions could constitute a positive feedback to climate change. A better understanding of its fate upon discharge to the Arctic shelf is therefore needed. In this study, bulk carbon isotopes as well as terrigenous and marine bioma...

  17. The Function of a Trade of a Post-Reform Siberian Town

    Directory of Open Access Journals (Sweden)

    Valery A. Skubnevsky

    2015-12-01

    Full Text Available The second half of the 19th Century saw the development of capitalism in Russia and formation of all-national market. The role of towns as centers of economy was growing, including trade-related ones. In Siberia before construction of Siberian railway in the 90s of the 19th cent. these processes were slow. The article shows peculiarities of Siberian trade, in particular, the role of town fairs and the ratio of fair and stationary trade in towns; it points out the main centers of trade and hierarchy of Siberian towns with regard to trade turnover. The author uses mainly pre-revolutionary statistical and reference works.

  18. First test of a partial Siberian snake for acceleration of polarized protons

    Science.gov (United States)

    Caussyn, D. D.; Baiod, R.; Blinov, B. B.; Chu, C. M.; Courant, E. D.; Crandell, D. A.; Derbenev, Ya. S.; Ellison, T. J. P.; Kaufman, W. A.; Krisch, A. D.; Lee, S. Y.; Minty, M. G.; Nurushev, T. S.; Ohmori, C.; Phelps, R. A.; Raczkowski, D. B.; Ratner, L. G.; Schwandt, P.; Stephenson, E. J.; Sperisen, F.; Przewoski, B. von; Wienands, U.; Wong, V. K.

    1995-09-01

    We recently studied the first acceleration of a spin-polarized proton beam through a depolarizing resonance using a partial Siberian snake. We accelerated polarized protons from 95 to 140 MeV with a constant 10% partial Siberian snake obtained using rampable solenoids. The 10% partial snake suppressed all observable depolarization during acceleration due to the Gγ=2 imperfection depolarizing resonance which occurred near 108 MeV. However, 20% and 30% partial Siberian snakes apparently moved an intrinsic depolarizing resonance, normally near 177 MeV, into our energy range; this caused some interesting, although not-yet-fully understood, depolarization.

  19. Cathinone increases body temperature, enhances locomotor activity, and induces striatal c-fos expression in the Siberian hamster.

    Science.gov (United States)

    Jones, S; Fileccia, E L; Murphy, M; Fowler, M J; King, M V; Shortall, S E; Wigmore, P M; Green, A R; Fone, K C F; Ebling, F J P

    2014-01-24

    Cathinone is a β-keto alkaloid that is the major active constituent of khat, the leaf of the Catha edulis plant that is chewed recreationally in East Africa and the Middle East. Related compounds, such as methcathinone and mephedrone have been increasing in popularity as recreational drugs, resulting in the recent proposal to classify khat as a Class C drug in the UK. There is still limited knowledge of the pharmacological effects of cathinone. This study examined the acute effects of cathinone on core body temperature, locomotor and other behaviors, and neuronal activity in Siberian hamsters. Adult male hamsters, previously implanted with radio telemetry devices, were treated with cathinone (2 or 5mg/kg i.p.), the behavioral profile scored and core body temperature and locomotor activity recorded by radio telemetry. At the end of the study, hamsters received vehicle or cathinone (5mg/kg) and neuronal activation in the brain was determined using immunohistochemical evaluation of c-fos expression. Cathinone dose-dependently induced significant (phamster.

  20. Oil and gas resources in the West Siberian Basin, Russia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The primary objective of this study is to assess the oil and gas potential of the West Siberian Basin of Russia. The study does not analyze the costs or technology necessary to achieve the estimates of the ultimate recoverable oil and gas. This study uses reservoir data to estimate recoverable oil and gas quantities which were aggregated to the field level. Field totals were summed to a basin total for discovered fields. An estimate of undiscovered oil and gas, from work of the US Geological Survey (USGS), was added to give a total basin resource volume. Recent production decline points out Russia`s need to continue development of its discovered recoverable oil and gas. Continued exploration is required to discover additional oil and gas that remains undiscovered in the basin.

  1. Persistent hyperplastic primary vitreous (PHPV) in two Siberian husky dogs.

    Science.gov (United States)

    Ori, J; Yoshikai, T; Yoshimura, S; Takenaka, S

    1998-02-01

    Three eyes in two Siberian husky dogs were clinically diagnosed as persistent hyperplastic primary vitreous (PHPV) by means of ophthalmoscopy and ultrasonography (USG). Examination of mildly affected PHPV eyes with an ophthalmoscope showed the axial part of the posterior capsule to be opaque. The central lesion of the posterior capsule in severely affected eyes had been opaque with many blood vessels. Echographic changes in mild cases of PHPV were outside of the lens, linearly hyperechoic, parallel to the posterior lens capsule. In a severely affected eyeball, funnel-shaped hyperechoic change was noted in the retrolental space. Two months later, phacoemulsification was performed for diagnostic treatment of PHPV since progressive cataract was observed in this eye.

  2. [Data from an expedition to study a Siberian vegan settlement].

    Science.gov (United States)

    Medkova, I L; Manchuk, V T; Mosiakina, L I; Polivanova, T V; Lundina, T A; Koroleva-Munts, L I

    1998-01-01

    Health status, the way of life and nourishment of 84 vegans in Siberian village (Krasnoyarsk region) were studied and compared with those of 26 meat-eaters. The investigation included work with a questionnaire, clinico-diagnostic and laboratory research. It was shown that a vegetarian diet improves the serum lipid spectrum (cholesterol, LPLD, cholesterol of LPNP, atherogenic coefficient), normalizes weight and cardiovascular system. The vegans had normal levels of vitamin B12 and serum Fe but the calcium level in this group was lowered as compared with the control group. The pathology of internals (nephroptosis, lithic diathesis, tendency to lithogenesis) was observed. Apparently, the high serum Zn levels found in both groups aren't directly caused by the diet but by climate and geographic factors.

  3. The Siberian Craton and its evolution in terms of the Rodinia hypothesis

    Institute of Scientific and Technical Information of China (English)

    Dmitry Gladkochub; Sergei Pisarevsky; Tatiana Donskaya; Lev Natapov; Anatoliy Mazukabzov; Arkadiy Stanevich; Eugene Sklyarov

    2006-01-01

    @@ Recent geochronological studies in southern Siberia support a Siberian assembly between 2.1 and 1.8 Ga. This broadly coincides with major orogenic events in most other Precambrian continents including Laurentia.

  4. Photoperiod Regulates vgf-Derived Peptide Processing in Siberian Hamsters.

    Science.gov (United States)

    Noli, Barbara; Brancia, Carla; Pilleri, Roberta; D'Amato, Filomena; Messana, Irene; Manconi, Barbara; Ebling, Francis J P; Ferri, Gian-Luca; Cocco, Cristina

    2015-01-01

    VGF mRNA is induced in specific hypothalamic areas of the Siberian hamster upon exposure to short photoperiods, which is associated with a seasonal decrease in appetite and weight loss. Processing of VGF generates multiple bioactive peptides, so the objective of this study was to determine the profile of the VGF-derived peptides in the brain, pituitary and plasma from Siberian hamsters, and to establish whether differential processing might occur in the short day lean state versus long day fat. Antisera against short sequences at the C- or N- termini of proVGF, as well as against NERP-1, TPGH and TLQP peptides, were used for analyses of tissues, and both immunohistochemistry and enzyme linked immunosorbent assay (ELISA) coupled with high-performance liquid (HPLC) or gel chromatography were carried out. VGF peptide immunoreactivity was found within cortex cholinergic perikarya, in multiple hypothalamic nuclei, including those containing vasopressin, and in pituitary gonadotrophs. ELISA revealed that exposure to short day photoperiod led to a down-regulation of VGF immunoreactivity in the cortex, and a less pronounced decrease in the hypothalamus and pituitary, while the plasma VGF levels were not affected by the photoperiod. HPLC and gel chromatography both confirmed the presence of multiple VGF-derived peptides in these tissues, while gel chromatography showed the presence of the VGF precursor in all tissues tested except for the cortex. These observations are consistent with the view that VGF-derived peptides have pleiotropic actions related to changing photoperiod, possibly by regulating cholinergic systems in the cortex, vasopressin hypothalamic pathways, and the reproductive axis.

  5. [Seasonal development of phloem in Siberian larch stems].

    Science.gov (United States)

    Antonova, G F; Stasova, V V

    2008-01-01

    The seasonal development of phloem in the stems of Siberian larch (Larix sibirica Ldb.) was studied over two seasons on 50-60-year-old trees growing in a natural stand in the Siberian forest-steppe zone. Trees at the age of 20-25 years were used to study metabolites in differentiating and mature phloem elements, cambial zone, and radially growing xylem cells in the period of early and late wood formation. The development of the current-year phloem in the stems of 50-60-year-old trees started, depending on climatic conditions, in the second-third decades of May, 10-20 days before the xylem formation, and ended together with the shoot growth cessation in late July. Monitoring of the seasonal activity of cambium producing phloem sieve cells and the duration of their differentiation compared to the xylem derivatives in the cambium demonstrated that the top production of phloem and xylem cells could coincide or not coincide during the season, while their differentiation activity was always in antiphase. Sieve cells in the early phloem are separated from those in the late phloem by a layer of tannin-containing cells, which are formed in the period when late xylem formation starts. The starch content in the structural elements of phloem depends on the state of annual xylem layer development. The content of low molecular weight carbohydrates, amino acids, organic acids, and phenols in phloem cells, cambial zone, and xylem derivatives of the cambium depends on the cell type and developmental stage as well as on the type of forming wood (early or late) differing by the cell wall parameters and, hence, by the requirement for assimilates. Significant differences in the dynamics of substances per dry weight and cell were observed during cell development.

  6. Photoperiod Regulates vgf-Derived Peptide Processing in Siberian Hamsters.

    Directory of Open Access Journals (Sweden)

    Barbara Noli

    Full Text Available VGF mRNA is induced in specific hypothalamic areas of the Siberian hamster upon exposure to short photoperiods, which is associated with a seasonal decrease in appetite and weight loss. Processing of VGF generates multiple bioactive peptides, so the objective of this study was to determine the profile of the VGF-derived peptides in the brain, pituitary and plasma from Siberian hamsters, and to establish whether differential processing might occur in the short day lean state versus long day fat. Antisera against short sequences at the C- or N- termini of proVGF, as well as against NERP-1, TPGH and TLQP peptides, were used for analyses of tissues, and both immunohistochemistry and enzyme linked immunosorbent assay (ELISA coupled with high-performance liquid (HPLC or gel chromatography were carried out. VGF peptide immunoreactivity was found within cortex cholinergic perikarya, in multiple hypothalamic nuclei, including those containing vasopressin, and in pituitary gonadotrophs. ELISA revealed that exposure to short day photoperiod led to a down-regulation of VGF immunoreactivity in the cortex, and a less pronounced decrease in the hypothalamus and pituitary, while the plasma VGF levels were not affected by the photoperiod. HPLC and gel chromatography both confirmed the presence of multiple VGF-derived peptides in these tissues, while gel chromatography showed the presence of the VGF precursor in all tissues tested except for the cortex. These observations are consistent with the view that VGF-derived peptides have pleiotropic actions related to changing photoperiod, possibly by regulating cholinergic systems in the cortex, vasopressin hypothalamic pathways, and the reproductive axis.

  7. Development of survival skills in captive-raised Siberian polecats (Mustela eversmanni) I: locating prey

    Science.gov (United States)

    Miller, Brian; Biggins, Dean; Wemmer, Chris; Powell, Roger; Hanebury, Lou; Horn, Deborah; Vargas, Astrid

    1990-01-01

    Captive-raised mustelids appear to have a rudimentary capacity to kill prey, but the skills necessary for locating prey may be eroded during captivity. We tested the maturational component of prey-searching behavior with captive-raised Siberian polecats (Mustela eversmanni) by subjecting polecats to a simulated prairie dog colony of 6 burrows within a 200 m2 arena. Ten naive Siberian polecats at ages 2.5, 3.5, and 4.5 months (30 total) were deprived of food for 12 hours. A dead prairie dog was placed in 1 prairie dog burrow and the other 5 were empty. A single Siberian polecat was released onto the colony shortly before sunset and its movements monitored from an observation tower. Older Siberian polecats located prey significantly quicker than younger polecats, but all age groups spent a great deal of time in surface activity not directed toward a burrow. When Siberian polecats were about 10 months old, all burrows in the arena were plugged with dirt including the burrow with the prairie dog. In this winter test, Siberian polecats located the prey but still spent a great deal of time in non-burrow directed surface activity. Economical use of surface time, with a low amount of non-burrow directed behavior, would presumably reduce the risk of predation for hunting polecats.

  8. Comparison of East Asian winter monsoon indices

    Directory of Open Access Journals (Sweden)

    Gao Hui

    2007-01-01

    Full Text Available Four East Asian winter monsoon (EAWM indices are compared in this paper. In the research periods, all the indices show similar interannual and decadal-interdecadal variations, with predominant periods centering in 3–4 years, 6.5 years and 9–15 years, respectively. Besides, all the indices show remarkable weakening trends since the 1980s. The correlation coefficient of each two indices is positive with a significance level of 99%. Both the correlation analyses and the composites indicate that in stronger EAWM years, the Siberian high and the higher-level subtropical westerly jet are stronger, and the Aleutian low and the East Asia trough are deeper. This circulation pattern is favorable for much stronger northwesterly wind and lower air temperature in the subtropical regions of East Asia, while it is on the opposite in weaker EAWM years. Besides, EAWM can also exert a remarkable leading effect on the summer monsoon. After stronger (weaker EAWM, less (more summer precipitation is seen over the regions from the Yangtze River valley of China to southern Japan, while more (less from South China Sea to the tropical western Pacific.

  9. Reserve Growth in Oil Fields of West Siberian Basin, Russia

    Science.gov (United States)

    Verma, Mahendra K.; Ulmishek, Gregory F.

    2006-01-01

    Although reserve (or field) growth has proven to be an important factor contributing to new reserves in mature petroleum basins, it is still a poorly understood phenomenon. Limited studies show that the magnitude of reserve growth is controlled by several major factors, including (1) the reserve booking and reporting requirements in each country, (2) improvements in reservoir characterization and simulation, (3) application of enhanced oil recovery techniques, and (4) the discovery of new and extensions of known pools in discovered fields. Various combinations of these factors can affect the estimates of proven reserves in particular fields and may dictate repeated estimations of reserves during a field's life. This study explores the reserve growth in the 42 largest oil fields in the West Siberian Basin, which contain about 55 percent of the basin's total oil reserves. The West Siberian Basin occupies a vast swampy plain between the Ural Mountains and the Yenisey River, and extends offshore into the Kara Sea; it is the richest petroleum province in Russia. About 600 oil and gas fields with original reserves of 144 billion barrels of oil (BBO) and more than 1,200 trillion cubic feet of gas (TCFG) have been discovered. The principal oil reserves and most of the oil fields are in the southern half of the basin, whereas the northern half contains mainly gas reserves. Sedimentary strata in the basin consist of Upper Triassic through Tertiary clastic rocks. Most oil is produced from Neocomian (Lower Cretaceous) marine to deltaic sandstone reservoirs, although substantial oil reserves are also in the marine Upper Jurassic and continental to paralic Lower to Middle Jurassic sequences. The majority of oil fields are in structural traps, which are gentle, platform-type anticlines with closures ranging from several tens of meters to as much as 150 meters (490 feet). Fields producing from stratigraphic traps are generally smaller except for the giant Talin field which

  10. Magmatism evolution on the last Neoproterozoic development stage of the western Siberian active continental margin

    Science.gov (United States)

    Vernikovskaya, Antonina E.; Vernikovsky, Valery A.; Matushkin, Nikolay Yu.; Kadilnikov, Pavel I.; Romanova, Irina V.

    2017-04-01

    .B., Kovach V.P. Neoproterozoic accretionary and collisional events on the western margin of the Siberian craton: new geological and geochronological evidence from the Yenisey Ridge // Tectonophysics, 2003, V. 375, P. 147-168. Vernikovsky V.A., Vernikovskaya A.E., Sal'nikova E.B., Berezhnaya N.G., Larionov A.N., Kotov A.B., Kovach V.P., Vernikovskaya I.V., Matushkin N.Yu., Yasenev A.M. Late Riphean alkaline magmatism in the western margin of the Siberian Craton: A result of continental rifting or accretionary events? // Doklady Earth Sciences, 2008, V. 419, Iss. 1, P. 226-230. Khanchuk A.I., Kemkin I.V., Kruk N.N. The Sikhote-Alin orogenic belt, Russian South East: Terranes and the formation of continental lithosphere based on geological and isotopic Data // Journal of Asian Earth Sciences, 2016, V. 120, P. 117-138.

  11. Last straw versus Blitzkrieg overkill: Climate-driven changes in the Arctic Siberian mammoth population and the Late Pleistocene extinction problem

    Science.gov (United States)

    Nikolskiy, P. A.; Sulerzhitsky, L. D.; Pitulko, V. V.

    2011-08-01

    A set of radiocarbon dates on woolly mammoth were obtained from several regions of Arctic Siberia: the New Siberian Islands ( n = 68), north of the Yana-Indigirka Lowland ( n = 43), and the Taimyr Peninsula ( n = 18). Based on these and earlier published dates ( n = 201) from the East Arctic, a comparative analysis of the time-related density distribution of 14C dates was conducted. It was shown that the frequencies of 14C dates under certain conditions reflect temporal fluctuations in mammoth numbers. At the end of the Pleistocene the number of mammoths in the East Arctic changed in a cyclic manner in keeping with a general "Milankovitch-like" trend. The fluctuations in numbers at the end of the Pleistocene occurred synchronously with paleoenvironmental changes controlled by global climatic change. There were three minima of relative mammoth numbers during the last 50 000 years: 22 000, 14 500-19 000, and 9500 radiocarbon years ago, or around 26 000, 16-20 000, and 10 500 calendar years respectively. The last mammoths lived on the New Siberian Islands, which were connected to the continent at that time, 9470 ± 40 radiocarbon years ago (10 700 ± 70 calendar years BP). This new youngest date approximates the extinction time of mammoths in the last continental refugium of the Holarctic. The adverse combination of environmental parameters was apparently a major factor in the critical reduction in mammoth numbers. The dispersal of humans into the Arctic areas of Siberia no later than 28 000 radiocarbon years ago did not overtly influence animal numbers. Humans were not responsible for the destruction of a sustainable mammoth population. The expanding human population could have become fatal to mammoths during strong the minima of their numbers, one of which occurred at the very beginning of the Holocene.

  12. Melatonin production accompanies arousal from daily torpor in Siberian hamsters.

    Science.gov (United States)

    Larkin, Jennie E; Yellon, Steven M; Zucker, Irving

    2003-01-01

    Arousal from deep hibernation is accompanied by a transient rise of melatonin (Mel) in circulation; there are no comparable analyses of Mel concentrations in species that undergo much shallower, shorter duration episodes of daily torpor. Serum Mel concentrations were determined during arousal from both natural daily torpor and torpor induced by 2-deoxy-D-glucose (2-DG) treatment (2,500 mg/kg, intraperitoneal [IP]); blood samples were drawn from the retro-orbital sinus of anesthetized Siberian hamsters. For animals kept in darkness during torpor, Mel concentrations were highest during early arousal when thermogenesis is maximal, and they decreased as body temperature increased during arousal and returned to baseline once euthermia was reestablished. In hamsters kept in the light during the torpor bout, Mel concentrations were elevated above basal values during arousal, but the response was significantly blunted in comparison with values recorded in darkness. Increased Mel concentrations were detected in hamsters only during arousal from torpor (either natural or 2-DG induced) and were not simply a result of the drug treatment; hamsters that remained euthermic or manifested mild hypothermia after drug treatment maintained basal Mel concentrations. We propose that increased Mel production may reflect enhanced sympathetic activation associated with intense thermogenesis during arousal from torpor rather than an adjustment of the circadian rhythm of Mel secretion.

  13. Sex differences in Siberian hamster ultradian locomotor rhythms.

    Science.gov (United States)

    Prendergast, Brian J; Stevenson, Tyler J; Zucker, Irving

    2013-02-17

    Sex differences in ultradian activity rhythms (URs) and circadian rhythms (CRs) were assessed in Siberian hamsters kept in long day (LD) or short day (SD) photoperiods for 40 weeks. For both sexes URs of locomotor activity were more prevalent, greater in amplitude and more robust in SDs. The UR period was longer in females than males in both day lengths. The reproductive system underwent regression and body mass declined during the initial 10 weeks of SD treatment, and in both sexes these traits spontaneously reverted to the LD phenotype at or before 40 weeks in SD, reflecting the development of neuroendocrine refractoriness to SD patterns of melatonin secretion. Hamsters of both sexes, however, continued to display SD-like URs at the 40 weeks time point. CRs were less prevalent and the waveform less robust and lower in amplitude in SDs than LDs; the SD circadian waveform also did not revert to the long-day phenotype after 40 weeks of SD treatment. Short day lengths enhanced ultradian and diminished circadian rhythms in both sexes. Day length controls several UR characteristics via gonadal steroid and melatonin-independent mechanisms. Sex differences in ultradian timing may contribute to sex diphenisms in rhythms of sleep, food intake and exercise.

  14. Constant darkness restores entrainment to phase-delayed Siberian hamsters.

    Science.gov (United States)

    Ruby, Norman F; Joshi, Nirav; Heller, H Craig

    2002-12-01

    Over 90% of Siberian hamsters (Phodopus sungorus) fail to reentrain to a 5-h phase delay of a 16:8-h photocycle. Because constant darkness (DD) restores rhythms disrupted by constant light, we tested whether DD could also restore entrainment. DD began 0, 5, or 14 days after a 5-h phase delay, and the light-dark cycle was reinstated 14 days later. All hamsters exposed to DD on day 0 reentrained, whereas 42% reentrained irrespective of whether DD began 5 or 14 days later. For these latter two groups, tau (tau) and alpha (alpha) in DD predicted reentrainment; animals that reentrained had a mean tau and alpha of 24.1 and 8.9 h, respectively, whereas those that failed to reentrain maintained a mean tau and alpha of 25.0 and of 7.1 h, respectively. Restoration of entrainment by DD is somewhat paradoxical because it suggests that reentrainment to the photocycle was prevented by continued exposure to that same photocycle. The dichotomy of circadian responses to DD suggests "entrainment" phenotypes that are similar to those of photoperiodic responders and nonresponders.

  15. Interval timer control of puberty in photoinhibited Siberian hamsters.

    Science.gov (United States)

    Park, Jin Ho; Kauffman, Alexander S; Paul, Matthew J; Butler, Matthew P; Beery, Annaliese K; Costantini, Ruth M; Zucker, Irving

    2006-10-01

    Puberty, which is markedly delayed in male Siberian hamsters (Phodopus sungorus) born into short day lengths, is controlled by an interval timer regulated by the duration of nocturnal melatonin secretion. Properties of the interval timer were assessed by perturbing normal patterns of melatonin secretion in males gestated and maintained thereafter in 1 of 2 short day lengths, 10 h light/day (10 L) or 12L. Melatonin secretion of short-day hamsters was suppressed by constant light treatment or modified by daily injection of propranolol to mimic nocturnal melatonin durations typical of long-day hamsters. Constant light treatment during weeks 3 to 5 induced early incomplete gonadal growth in 12L but not 10 L hamsters but did not affect late onset of gonadal development indicative of puberty in either photoperiod. Propranolol treatment during postnatal weeks 3 to 5 induced transient growth of the testes and ultimately delayed the timing of puberty by 3 weeks. Similar treatments between weeks 5 and 7 or on alternate weeks for 24 weeks did not affect the interval timer. The first 2 weeks after weaning may constitute a critical period during which the interval timer is highly responsive to photoperiod. Alternatively, the hamsters' photoperiodic history rather than age or developmental stage may be the critical variable. The interpolation of long-day melatonin signals at the time of weaning does not appear to reset the interval timer to its zero position but may reduce timer responsiveness to long-day melatonin signals several weeks later.

  16. North Atlantic Origin of Interdecadal variability of Siberian High

    Science.gov (United States)

    Kim, Seon-Hwa; Sung, Mi-Kyung; Kim, Baek-Min

    2017-04-01

    We suggest that the changes in the mean atmospheric circulation structure in the North Atlantic Ocean upstream region of Eurasian continent play an important role in the interdecadal variability of Siberian High (SH) through the modulation of Ural blocking frequency. Previous studies suggested that the interdecadal variability of SH is partly explained by the Arctic Oscillation. However, in this study, we emphasize the role of 'Warm Arctic and Cold Eurasia (WACE)', which is the second mode of winter surface air temperature variability over Eurasia. We show that the correlation between SH and WACE is high in general compared to that between SH and AO. However, the correlation between SH and WACE does not always exhibit high constant value. It shows a distinctive interdecadal fluctuation in the correlation. We found that this fluctuation in the correlation is due to the interdecadal fluctuation of the continental trough over the North Atlantic and the resultant strengthening of in-situ atmospheric baroclinicity. This accompanies changes in the transient vorticity flux divergence which leads to the downstream wave development and anomalous anticyclonic flow near Ural region. Obviously, the existence of anticyclonic flow over Ural region helps more frequent occurrence of Ural blocking and it is shown that this condition favors positive WACE event, which links to an intensified SH.

  17. Learned magnetic compass orientation by the Siberian hamster, Phodopus sungorus

    Energy Technology Data Exchange (ETDEWEB)

    Deutschlander, Mark E.; Freake, Michael J.; Borland, Christopher; Phillips, John B.; Madden, R C.; Anderson, Larry E.; Wilson, B W.

    2003-04-01

    Magnetic orientation has been demonstrated in Siberian hamsters, Phodopus sungorus. The behavior, using a nest building assay, shows a directional preference in nest position and appears in this animal to be a learned behavior. Hamsters were housed prior to testing in rectangular cages aligned along perpendicular axes. When subsequently tested in a radially-symmetrical arena, the hamsters positioned their nests in a bimodal distribution that coincided with the magnetic direction of the long-axis of the holding cages. In addition, results are presented that illustrate some of the factors that can influence behavioral responses to the magnetic field. In particular for P. sungorus, holding conditions prior to testing and the presence of non-magnetic cues may influence the strength and expression of magnetic orientation. Failure to consider these and other factors may help to explain why previous attempts to demonstrate magnetic orientation in a number of rodent species have failed or, when positive results have been obtained, have been difficult to replicate in other laboratories.

  18. Arable weed flora in the Western Siberian grain belt

    Directory of Open Access Journals (Sweden)

    Kämpf, Immo

    2016-02-01

    Full Text Available Between Ekaterinburg and Nowosibirsk, in the Western Siberian grain belt, spring wheat is grown on fertile Chernozem soils. Field and farm sizes are large but the land-use intensity per area is low compared to Central Europe. Fertilizers and pesticides are applied only in low to moderate quantities and yields range between 10 and 20 dt ha-1. We studied the arable weed flora in the northern forest steppe zone of Tyumen region using a randomized sampling design. Surprisingly, the species richness was only moderate, on average 9.8 ± 3.8 species per 100 m². Compared to weed communities of Bashkiria (Southern Ural and less intensively used arable land of Central Europe these numbers are rather low. Moreover, most of the recorded species were cosmopolitans or widely distributed throughout the temperate zone. We suggest that the land use intensity was high enough to reduce the density of a number of weed species in a way that they were not registered by our random sampling design. The limited conservational value of the weed vegetation of large grain fields in Tyumen leads to the conclusion that if intensification of land use is unavoidable, it should be directed to arable land and not to ex-arable land or ancient grassland, which is of higher conservation value.

  19. Palynological constraints on timing and duration of Siberian Traps volcanic events

    Science.gov (United States)

    Visscher, Henk; Svensen, Henrik; Looy, Cindy; Fristad, Kirsten; Polozov, Alexander; Planke, Sverre

    2010-05-01

    Lacustrine sediments intercalated locally in the voluminous flood basalts and pyroclastic rocks of the Siberian Traps igneous province are characterized by the presence of surprisingly diverse assemblages of macroscopic and microscopic plant fossils. In addition, these intertrappean sediments contain a wide variety of faunal remains, such as conchostracans, ostracodes, gastropods and insects. Outside the area of presently exposed flood basalt, plant fossils may also occur abundantly in the sedimentary infill of crater lakes above vent structures in the southern part of the Tunguska Basin on the Siberian Platform. Because of a possible cause-effect relationship between Siberian Traps magmatism and end-Permian mass-extinctions, vegetation that must have grown in the immediate vicinity of the eruptive centres is one of the most obvious biota to be investigated for evidence of terrestrial biosphere crisis. On the basis of literature information and new palynological data from cored crater-lake sediments, in this presentation we briefly address the basic question to what extent the Siberian plant fossil record confirms age-equivalence between biotic and volcanic events. At present, most published biostratigraphic interpretations of the floral and faunal records refute any correspondence of end-Permian biotic turnover with the Siberian Traps. In effect, the records are long since being used to advocate an exclusively Triassic age for the Siberian volcanism, the main phase of flood basalt eruption taking place during late Early Triassic (Olenekian) and early Middle Triassic (Anisian) times. However, re-evaluation of the chronostratigraphic significance of plant megafossils and faunal remains has resulted in alternative views, which suggest a Late Permian age for part or the whole of the volcanic sequence exposed on the Siberian Platform. Compositional characters of palynomorph assemblages indicate age-equivalence of the flood basalts in the northern part of the Tunguska

  20. Radix dolgini: The integrative taxonomic approach supports the species status of a Siberian endemic snail (Mollusca, Gastropoda, Lymnaeidae).

    Science.gov (United States)

    Vinarski, Maxim V; Aksenova, Olga V; Bespalaya, Yulia V; Bolotov, Ivan N; Schniebs, Katrin; Gofarov, Mikhail Yu; Kondakov, Alexander V

    2016-01-01

    The molecular techniques are the standard tool for the study of the taxonomic position and phylogenetic affinities of the lymnaeid genus Radix Montfort, 1810, and the majority of the European representatives of this taxon have been studied in this respect. However, a plethora of nominal species of Radix described from Northern Asia (Siberia and the Russian Far East) are still characterized only morphologically, raising some doubts concerning their validity. In this paper, we present the triple (morphological, molecular, and zoogeographical) evidence that there is at least one endemic species of Radix, Radix dolgini (Gundrizer and Starobogatov, 1979), widely distributed in Siberia and Western Mongolia. Phylogenetically, it is a sister species to the European R. labiata (Rossmaessler, 1835) [=R. peregra auct.], and their common ancestor most probably lived in the Pliocene, nearly 3.25Myr ago. Our results assume the existence of an extended dispersal barrier for freshwater hydrobionts between Europe and Siberia in the Late Pliocene that may be important for biogeographical explanations. Three other nominal Siberian species of Radix: R. kurejkae (Gundrizer and Starobogatov, 1979), R. gundrizeri (Kruglov and Starobogatov, 1983), and R. ulaganica (Kruglov and Starobogatov, 1983) proved to be the junior synonyms of R. dolgini.

  1. The crust and mantle beneath the Siberian provinces: a preliminary model based on new receiver function analysis

    DEFF Research Database (Denmark)

    Soliman, Mohammad Youssof Ahmad; Artemieva, Irina; Thybo, Hans;

    2012-01-01

    The new receiver function (RF) study complements the existing seismic data on the crustal and upper mantle structure at the margins of the Siberian craton and the West Siberian Basin. So far, RF studies of Siberia have been largely restricted to the Baikal rift zone (Gao et al., 2004; Liu and Gao...

  2. Being at the right time at the right place: interpreting the annual life cycle of Afro-Siberian red knots

    NARCIS (Netherlands)

    Leyrer, J.

    2011-01-01

    This thesis describes the possible selection pressures acting on survival and, indirectly, on reproduction of Afro-Siberian red knots Calidris canutus canutus while wintering and migrating. Afro-Siberian red knots are long-distance migrants. They travel between the West African wintering areas and t

  3. Plume or no Plume, the Case of the Siberian Trap Formation

    Science.gov (United States)

    Reichow, M. K.; Saunders, A. D.; White, R. V.; Al'Mukhamedov, A. I.; Medvedev, A. I.; Inger, S.

    2003-12-01

    The generation mechanism of continental large igneous provinces, such as the Siberian Traps, are matters of recent debate, particularly their relation to mantle plumes derived from the Earth's interior. Alternative models relate the formation of large igneous provinces to bolide impacts or small-scale convection at the boundary of asymmetric lithospheres. Neither of these models is without criticism and each model cannot explain all characteristics of continental flood basalt formation alone. However, strong support for the involvement of a mantle plume comes from the observation that large volumes of basaltic melts ( ˜3 x 106 km3) erupted within a short period of time (pulse of volcanism extruded over large areas of the Siberian craton. Although the major and trace element data are consistent with a plume origin for the Siberian Traps, they cannot prove it; however, magma volume and timing constraints do strongly suggest that a mantle plume was involved in the formation of the Earth's largest continental flood basalt province.

  4. The first paleomagnetic data on dolerites from Jeannette Island (New Siberian Islands, Arctic)

    Science.gov (United States)

    Zhdanova, A. I.; Metelkin, D. V.; Vernikovsky, V. A.; Matushkin, N. Yu.

    2016-06-01

    The first paleomagnetic data on dolerite dikes from the volcanogenic-sedimentary section of Jeannette Island (De Long Archipelago, New Siberian Islands) are discussed. The petromagnetic data and results of the baked contact and fold tests are used to substantiate the nature of the characteristic magnetization component, which in combination with the 40Ar/39Ar dates implies its likely Late Precambrian-Early Paleozoic age. The calculated paleomagnetic pole makes it possible to extend the trajectory of the apparent polar movement for the New Siberian Islands block and confirms the assumption that this structural element of the Arctic shelf evolved as a terrane. Two variants of paleotectonic interpretation of the obtained data and their consistency with the available data on the geology and tectonics of the New Siberian Islands are considered.

  5. Photoperiodic influences on ultradian rhythms of male Siberian hamsters.

    Science.gov (United States)

    Prendergast, Brian J; Zucker, Irving

    2012-01-01

    Seasonal changes in mammalian physiology and behavior are proximately controlled by the annual variation in day length. Long summer and short winter day lengths markedly alter the amplitude of endogenous circadian rhythms and may affect ultradian oscillations, but the threshold photoperiods for inducing these changes are not known. We assessed the effects of short and intermediate day lengths and changes in reproductive physiology on circadian and ultradian rhythms of locomotor activity in Siberian hamsters. Males were maintained in a long photoperiod from birth (15 h light/day; 15 L) and transferred in adulthood to 1 of 7 experimental photoperiods ranging from 14 L to 9 L. Decreases in circadian rhythm (CR) robustness, mesor and amplitude were evident in photoperiods ≤14 L, as were delays in the timing of CR acrophase and expansion of nocturnal activity duration. Nocturnal ultradian rhythms (URs) were comparably prevalent in all day lengths, but 15 L markedly inhibited the expression of light-phase URs. The period (τ'), amplitude and complexity of URs increased in day lengths ≤13 L. Among hamsters that failed to undergo gonadal regression in short day lengths (nonresponders), τ' of the dark-phase UR was longer than in photoresponsive hamsters; in 13 L the incidence and amplitude of light-phase URs were greater in hamsters that did not undergo testicular regression. Day lengths as long as 14 L were sufficient to trigger changes in the waveform of CRs without affecting UR waveform. The transition from a long- to a short-day ultradian phenotype occurred for most UR components at day lengths of 12 L-13 L, thereby establishing different thresholds for CR and UR responses to day length. At the UR-threshold photoperiod of 13 L, differences in gonadal status were largely without effect on most UR parameters.

  6. Circadian arrhythmia dysregulates emotional behaviors in aged Siberian hamsters.

    Science.gov (United States)

    Prendergast, Brian J; Onishi, Kenneth G; Patel, Priyesh N; Stevenson, Tyler J

    2014-03-15

    Emotional behaviors are influenced by the circadian timing system. Circadian disruptions are associated with depressive-like symptoms in clinical and preclinical populations. Circadian rhythm robustness declines markedly with aging and may contribute to susceptibility to emotional dysregulation in aged individuals. The present experiments used a model of chronic circadian arrhythmia generated noninvasively, via a series of circadian-disruptive light treatments, to investigate interactions between circadian desynchrony and aging on depressive- and anxiety-like behaviors, and on limbic neuroinflammatory gene expression that has been linked with emotionality. We also examined whether a social manipulation (group housing) would attenuate effects of arrhythmia on emotionality. In aged (14-18 months of age) male Siberian hamsters, circadian arrhythmia increased behavioral despair and decreased social motivation, but decreased exploratory anxiety. These effects were not evident in younger (5-9 months of age) hamsters. Social housing (3-5 hamsters/cage) abolished the effects of circadian arrhythmia on emotionality. Circadian arrhythmia alone was without effect on hippocampal or cortical interleukin-1β (IL-1β) and indoleamine 2,3-dioxygenase (Ido) mRNA expression in aged hamsters, but social housing decreased hippocampal IL-1β and Ido mRNAs. The data demonstrate that circadian disruption can negatively impact affective state, and that this effect is pronounced in older individuals. Although clear associations between circadian arrhythmia and constitutive limbic proinflammatory activity were not evident, the present data suggest that social housing markedly inhibits constitutive hippocampal IL-1β and Ido activity, which may contribute to the ameliorating effects of social housing on a number of emotional behaviors.

  7. Homeostatic regulation of sleep in arrhythmic Siberian hamsters.

    Science.gov (United States)

    Larkin, Jennie E; Yokogawa, Tohei; Heller, H Craig; Franken, Paul; Ruby, Norman F

    2004-07-01

    Sleep is regulated by independent yet interacting circadian and homeostatic processes. The present study used a novel approach to study sleep homeostasis in the absence of circadian influences by exposing Siberian hamsters to a simple phase delay of the photocycle to make them arrhythmic. Because these hamsters lacked any circadian organization, their sleep homeostasis could be studied in the absence of circadian interactions. Control animals retained circadian rhythmicity after the phase shift and re-entrained to the phase-shifted photocycle. These animals displayed robust daily sleep-wake rhythms with consolidated sleep during the light phase beginning about 1 h after light onset. This marked sleep-wake pattern was circadian in that it persisted in constant darkness. The distribution of sleep in the arrhythmic hamsters over 24 h was similar to that in the light phase of rhythmic animals. Therefore, daily sleep amounts were higher in arrhythmic animals compared with rhythmic ones. During 2- and 6-h sleep deprivations (SD), it was more difficult to keep arrhythmic hamsters awake than it was for rhythmic hamsters. Because the arrhythmic animals obtained more non-rapid eye movement sleep (NREMS) during the SD, they showed a diminished compensatory response in NREMS EEG slow-wave activity during recovery sleep. When amounts of sleep during the SD were taken into account, there were no differences in sleep homeostasis between experimental and control hamsters. Thus loss of circadian control did not alter the homeostatic response to SD. This supports the view that circadian and homeostatic influences on sleep regulation are independent processes.

  8. Melatonin attenuates photic disruption of circadian rhythms in Siberian hamsters.

    Science.gov (United States)

    Ruby, N F; Kang, T; Heller, H C

    1997-10-01

    Body temperature (Tb) was recorded via a biotelemetry system from 28 adult male Siberian hamsters maintained in a light-dark (LD) cycle of 16 h light/day for several months. After Tb was recorded for 3 wk, the LD cycle was phase delayed by extending the light phase by 5 h for 1 day; animals remained on a 16:8 LD cycle for the remainder of the experiment. Hamsters were injected daily with melatonin or vehicle solution for several weeks, beginning either 2 mo after (experiment 1) or on the day of (experiment 2) the phase shift; injections occurred within 30 min of dark onset. In experiment 1, 75% of animals free ran with circadian periods >24 h, beginning on the day of the phase shift, and never reentrained to the LD cycle; no hamsters unambiguously entrained to daily injections. In contrast, 78% of animals in experiment 2 entrained to melatonin injections, and 71% of those animals subsequently reentrained to the photocycle when the injection regimen ended. No vehicle-treated animals entrained to the injection schedule. Melatonin had no effect on daily mean Tb and Tb rhythm amplitude in either experiment; however, melatonin doubled the duration of a hyperthermic response that occurred after each injection. Thus melatonin can prevent loss of entrainment induced by a phase shift of the LD cycle but cannot restore entrainment to free-running animals. Failure to reentrain in the presence of two appropriately coordinated entraining agents also suggests that a phase shift of the photocycle can diminish the sensitivity of the circadian system to both photic and nonphotic input.

  9. Multiple oil families in the west Siberian basin

    Energy Technology Data Exchange (ETDEWEB)

    Peters, K.E.; Huizinga, B.J.; Lee, C.Y. [Chevron Overseas Petroleum Inc., San Ramon, CA (United States); Kontorovich, A.Eh. [Siberian Scientific Research Institute for Geology, Novosibirsk (Russian Federation); Moldowan, J.M. [Chevron Petroleum Technology Company, Richmond, CA (United States)

    1994-06-01

    Two major oil families are identified in the West Siberian basin. Twenty-six of 32 analyzed oils occur in Jurassic and cretaceous reservoirs and are derived from anoxic marine Upper Jurassic Bazhenov source rock. These oils are widely distributed both north and immediately south of the Ob River, and their biomarker ratios indicate a wide range of source rock thermal maturity from early to middle oil window (Van-Egan, Russkoye, Samotlor, Sovninsko-Sovyet, Olyenye, Ozynornoye, and Kogolym), to peak oil window (Srednekhulym, Yem-Yegov, Vostochno-Surgut, Khokhryakov, Fedorov, and Urengoi), to late oil window (Salym). Some of these oils have been mildly (e.g., Fedorov 75) to heavily (e.g., Russkoye) biodegraded in the reservoir. The Bazhenov-sourced oils show different compositions that support regional variations of organic facies in the source rock. Six nonbiodegraded, highly mature oils show geochemical characteristics that suggest they were derived from clastic-rich lacustrine or nearshore marine source rocks dominated by terrigenous higher plant input like those in the Lower to Middle Jurassic Tyumen Formation, although no correlation was observed between the oils and single rock sample (Yem-Yegov 15) from the formation. The six oils occur in the Tyumen (Taitym, Geologiche, and Cheremshan) and fractured basement/Paleozoic (Gerasimov, Yagyl Yakh, and Verchnekombar) reservoirs in positions readily accessible to any oil migrating from the Tyumen source rock. For example, at the Gerasimov locations, the Tyumen Formation lies unconformably on weathered basement-Paleozoic reservoir rocks. Most of the probable Tyumen-sourced oils are from south of the Ob River, but the occurrence of Geologiche oil to the north suggests that related oils may be widespread in the basin.

  10. Numerical studies of Siberian snakes and spin rotators for RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Luccio, A.

    1995-04-17

    For the program of polarized protons in RHIC, two Siberian snakes and four spin rotators per ring will be used. The Snakes will produce a complete spin flip. Spin Rotators, in pairs, will rotate the spin from the vertical direction to the horizontal plane at a given insertion, and back to the vertical after the insertion. Snakes, 180{degrees} apart and with their axis of spin precession at 90{degrees} to each other, are an effective means to avoid depolarization of the proton beam in traversing resonances. Classical snakes and rotators are made with magnetic solenoids or with a sequence of magnetic dipoles with fields alternately directed in the radial and vertical direction. Another possibility is to use helical magnets, essentially twisted dipoles, in which the field, transverse the axis of the magnet, continuously rotates as the particles proceed along it. After some comparative studies, the authors decided to adopt for RHIC an elegant solution with four helical magnets both for the snakes and the rotators proposed by Shatunov and Ptitsin. In order to simplify the construction of the magnets and to minimize cost, four identical super conducting helical modules will be used for each device. Snakes will be built with four right-handed helices. Spin rotators with two right-handed and two left-handed helices. The maximum field will be limited to 4 Tesla. While small bore helical undulators have been built for free electron lasers, large super conducting helical magnets have not been built yet. In spite of this difficulty, this choice is dictated by some distinctive advantages of helical over more conventional transverse snakes/rotators: (i) the devices are modular, they can be built with arrangements of identical modules, (ii) the maximum orbit excursion in the magnet is smaller, (iii) orbit excursion is independent from the separation between adjacent magnets, (iv) they allow an easier control of the spin rotation and the orientation of the spin precession axis.

  11. Photoperiodic regulation of FGF21 production in the Siberian hamster.

    Science.gov (United States)

    Samms, Ricardo J; Fowler, Maxine J; Cooper, Scott; Emmerson, Paul; Coskun, Tamer; Adams, Andrew C; Kharitonenkov, Alexei; Tsintzas, Kostas; Ebling, Francis J P

    2014-06-01

    This article is part of a Special Issue "Energy Balance". FGF21 is an endocrine member of the fibroblast growth factor superfamily that has been shown to play an important role in the physiological response to nutrient deprivation. Food restriction enhances hepatic FGF21 production, which serves to engage an integrated response to energy deficit. Specifically, elevated FGF21 levels lead to reduced gluconeogenesis and increased hepatic ketogenesis. However, circulating FGF21 concentrations also paradoxically rise in states of metabolic dysfunction such as obesity. Furthermore, multiple peripheral tissues also produce FGF21 in addition to the liver, raising questions as to its endocrine and paracrine roles in the control of energy metabolism. The objectives of this study were to measure plasma FGF21 concentrations in the Siberian hamster, a rodent which undergoes a seasonal cycle of fattening and body weight gain in the long days (LD) of summer, followed by reduction of appetite and fat catabolism in the short days (SD) of winter. Groups of adult male hamsters were raised in long days, and then exposed to SD for up to 12 weeks. Chronic exposure of LD animals to SD led to a significant increase in circulating FGF21 concentrations. This elevation of circulating FGF21 was preceded by an increase in liver FGF21 protein production evident as early as 4 weeks of exposure to SD. FGF21 protein abundance was also increased significantly in interscapular brown adipose tissue, with a positive correlation between plasma levels of FGF21 and BAT protein abundance throughout the experimental period. Epididymal white adipose tissue and skeletal muscle (gastrocnemius) also produced FGF21, but levels did not change in response to a change in photoperiod. In summary, a natural programmed state of fat catabolism was associated with increased FGF21 production in the liver and BAT, consistent with the view that FGF21 has a role in adapting hamsters to the hypophagic winter state.

  12. Social thermoregulation and torpor in the Siberian hamster.

    Science.gov (United States)

    Jefimow, Małgorzata; Głabska, Marta; Wojciechowski, Michał S

    2011-04-01

    Social thermoregulation and huddling bring about energy benefits to animals sharing a nest because of the smaller surface-to-volume ratio of a huddle and the higher local temperature in the nest. We tested whether living in groups and huddling affect daily torpor, metabolic rate and seasonal changes in the body mass of a small heterothermic rodent, the Siberian hamster (Phodopus sungorus), housed under semi-natural conditions both singly and in groups of four litter-mates. We predicted that in hamsters housed in groups: (1) synchronized torpor bouts would be longer and deeper than non-synchronized ones but shallower than in solitary hamsters, (2) seasonal variations in metabolic rate would be lower than in solitary hamsters, and (3) the winter decrease in body mass would be smaller in grouped than in singly housed hamsters. We found that group housing led to a smaller decrease in body mass in winter, and affected the length and depth of daily torpor. In group-living hamsters more than 50% of all torpor episodes were synchronized and torpid animals were often found in huddles formed of all cage-mates. The longest and deepest torpor bouts in groups were recorded when all animals in a group entered torpor simultaneously. Although the minimum body temperature during torpor was higher, torpor duration was slightly longer than in solitary hamsters. We did not record significant differences in the body mass-adjusted rate of oxygen consumption between solitary and grouped animals, either in the cold or at the lower critical temperature. We conclude that social thermoregulation enables maintenance of a larger body mass, and thus a larger body fat content, which can ensure better body condition at the beginning of the reproductive season.

  13. Photoperiodic influences on ultradian rhythms of male Siberian hamsters.

    Directory of Open Access Journals (Sweden)

    Brian J Prendergast

    Full Text Available Seasonal changes in mammalian physiology and behavior are proximately controlled by the annual variation in day length. Long summer and short winter day lengths markedly alter the amplitude of endogenous circadian rhythms and may affect ultradian oscillations, but the threshold photoperiods for inducing these changes are not known. We assessed the effects of short and intermediate day lengths and changes in reproductive physiology on circadian and ultradian rhythms of locomotor activity in Siberian hamsters. Males were maintained in a long photoperiod from birth (15 h light/day; 15 L and transferred in adulthood to 1 of 7 experimental photoperiods ranging from 14 L to 9 L. Decreases in circadian rhythm (CR robustness, mesor and amplitude were evident in photoperiods ≤14 L, as were delays in the timing of CR acrophase and expansion of nocturnal activity duration. Nocturnal ultradian rhythms (URs were comparably prevalent in all day lengths, but 15 L markedly inhibited the expression of light-phase URs. The period (τ', amplitude and complexity of URs increased in day lengths ≤13 L. Among hamsters that failed to undergo gonadal regression in short day lengths (nonresponders, τ' of the dark-phase UR was longer than in photoresponsive hamsters; in 13 L the incidence and amplitude of light-phase URs were greater in hamsters that did not undergo testicular regression. Day lengths as long as 14 L were sufficient to trigger changes in the waveform of CRs without affecting UR waveform. The transition from a long- to a short-day ultradian phenotype occurred for most UR components at day lengths of 12 L-13 L, thereby establishing different thresholds for CR and UR responses to day length. At the UR-threshold photoperiod of 13 L, differences in gonadal status were largely without effect on most UR parameters.

  14. Sources and the flux pattern of dissolved carbon in rivers of the Yenisey basin draining the Central Siberian Plateau

    Science.gov (United States)

    Prokushkin, A. S.; Pokrovsky, O. S.; Shirokova, L. S.; Korets, M. A.; Viers, J.; Prokushkin, S. G.; Amon, R. M. W.; Guggenberger, G.; McDowell, W. H.

    2011-10-01

    Frequent measurements of dissolved organic (DOC) and inorganic (DIC) carbon concentrations in rivers during snowmelt, the entire ice-free season, and winter were made in five large watersheds (15 000-174 000 km2) of the Central Siberian Plateau (Yenisey River basin). These differ in the degree of continuous permafrost coverage, mean annual air temperature, and the proportion of tundra and forest vegetation. With an annual DOC export from the catchment areas of 2.8-4.7 gC m - 2 as compared to an annual DIC export of 1.0-2.8 gC m - 2, DOC was the dominant component of terrigenous C released to rivers. There was strong temporal variation in the discharge of DOC and DIC. Like for other rivers of the pan-arctic and boreal zones, snowmelt dominated annual fluxes, being 55-71% for water runoff, 64-82% for DOC and 37-41% for DIC. Likewise, DOC and DIC exhibited also a strong spatial variation in C fluxes, with both dissolved C species decreasing from south to north. The rivers of the southern part of the plateau had the largest flow-weighted DOC concentrations among those previously reported for Siberian rivers, but the smallest flow-weighted DIC concentrations. In the study area, DOC and DIC fluxes were negatively correlated with the distribution of continuous permafrost and positively correlated with mean annual air temperature. A synthesis of literature data shows similar trends from west to east, with an eastward decrease of dissolved C concentrations and an increased proportion of DOC in the total dissolved C flux. It appears that there are two contemporary limitations for river export of terrigenous C across Siberia: (1) low productivity of ecosystems with respect to potentially mobilizable organic C, slow weathering rates with concomitant small formation of bicarbonate, and/or wildfire disturbance limit the pools of organic and inorganic C that can be mobilized for transport in rivers (source-limited), and (2) mobilization of available pools of C is constrained by

  15. An East Asian Subtropical Summer Monsoon Index and Its Relationship to Summer Rainfall in China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ping; ZHOU Zijiang

    2009-01-01

    Using the monthly mean NCEP/NCAR reanalysis data and the monthly rainfall observations at 160 rain gauge stations of China during 1961-1999, and based on major characteristics of the atmospheric circulation over East Asia and the western Pacific, a simple index for the East Asian subtropical summer monsoon (EASSM) is defined. The relationship between this index and summer rainfall in China and associated circulation features are examined. A comparison is made between this index and other monsoon indices. The results indicate that the index defined herein is reflective of variations of both the thermal low pressure centered in Siberia and the subtropical ridge over the western Pacific. It epitomizes the intensity of the EASSM and the variability of summer rainfall along the Yangtze River. Analysis shows that the Siberian low has a greater effect on the rainfall than the subtropical ridge, suggesting that the summer rainfall variability over the eastern parts of China is to a large extent affected by anomalies of the atmospheric circulation and cold air development in the midlatitudes. Taking into account of the effects of both the Siberian low and the subtropical ridge can better capture the summer rainfall anomalies of China. The index exhibits interannual and decadai variabilities, with high-index values occurring mainly in the 1960s and 1970s and low-index values in the 1980s and 1990s. When the EASSM index is low, the Siberian low and the subtropical ridge are weaker, and northerly wind anomalies appear at low levels over the midlatitudes and subtropics of East Asia, whereas southwesterly wind anomalies dominate in the upper troposphere over the tropics and subtropics of Asia and the western Pacific. The northerly wind anomalies bring about frequent cold air disturbances from the midlatitudes of East Asia, strengthening the convergence and ascending motions along the Meiyu front, and result in an increase of summer rainfall over the Yangtze River.

  16. Variability of needle structure in Siberian stone pine in provenance plantations

    OpenAIRE

    2013-01-01

    Siberian stone pine (Pinus sibirica Du Tour) is one of the most common trees in Siberia. Its natural range is from the Ural Mountains to the Aldan river and from the Arctic Circle to northern Mongolia. The climate in natural Siberian stone pine sites influences the whole plant organism, particularly its needle structure, and the response to thisoccurs at specific morphological and anatomical levels. The genotypical and environmental effects on needle structure in different Siberianstone pine ...

  17. Do Siberian yoga practitioners risk health if they follow lacto vegetarian diet?

    OpenAIRE

    Klimatskaya, Liudmila; Zaitseva, Olga

    2015-01-01

    Background: Practicing yoga has become widely popular in Siberia and vegetarian diet constitutes one of its most important assumptions with a great impact on the human body. However, vegetarians are not the tradition in Siberia. Aim of the study: To evaluate the diet and assess whether Siberian yoga practitioners risk health reducing some nutrients’ intake. Material and methods: 47 Siberian women practicing yoga (program “Art of Living”), aged 31.9±7.4 years and the residents of Krasno...

  18. Arctic-Asian Mobile Belt - Global Structure in the North, Central, and East Asia

    Science.gov (United States)

    Shokalsky, Sergey; Petrov, Oleg; Pospelov, Igor; Kashubin, Sergey; Sobolev, Nikolay; Petrov, Evgeny

    2014-05-01

    Over the last decade under the international project of five countries, the geological surveys of Russia, China, Kazakhstan, Mongolia, and the Republic of Korea, with the participation of national academies of sciences in these countries compiled a set of digital maps at 1:2.5 M scale. It includes geological, tectonic, metallogenic maps and map of energy resources with databases for North, Central, and East Asia, area of more than 30 million km2. Map compilation was supervised by the Subcommission for Northern Eurasia and Subcommission for Tectonic Maps of the Commission for the Geological Map of the World under the auspices of UNESCO (CGMW). The set of maps was displayed at the 33rd IGC (Oslo, 2008) and 34th IGC (Brisbane, 2012). One of the largest accretion collages of orogenic belts of different ages on the planet (from the Neoproterozoic to Early Mesozoic) is clearly shown in the tectonic map compiled under the joint project. Extended polychronous mobile belt is bounded in the west by the East European Craton, in the east, by the Siberian Craton, in the south, by a chain of Gondwana cratonic blocks - North China, Tarim, Tajik. In the north it can be traced as a broad band within the Circumpolar Region, where it is limited by the North American Craton. The central part of the accretionary belt is hidden under the Meso-Cenozoic sediments of Western Siberia. Analysis of vast geological material shows that the Arctic-Asian mobile belt was formed on place of an extensive paleo-ocean, which closed with a successive rejuvenation of suture ophiolite zones from the marginal to axial zone and along strike to the north and east of the South Siberian segment towards Paleopacific. Arctic-Asian mobile belt is characterized by a complex combination of accretionary and riftogenic tectonic-magmatic processes. At its early stages, accretionary tectonics with a wide development of volcanic belts dominated; at the late ones (in the Late Paleozoic, Mesozoic, and Cenozoic

  19. Magmatism evolution in the Nori'lsk region (Siberian trap province)

    Science.gov (United States)

    Krivolutskaya, Nadezhda

    2010-05-01

    The NW Siberian trap province is very important for our understanding of evolution of huge magmatic system (T1) and origin unique Pt-Cu-Ni deposits. To solve these genetic problems (including correlation between effusive and intrusive rocks) it is necessary to get accurate information about magmatism migration in space and in time inside different tectonic structures in the Noril'sk region. Thed latter takes outstanding place on the Siberian platform due to its geological features. It consists of two main areas covered by volcanic rocks: I. Kharaelakhsky trough (on West) and II. plateau Putorana (on East) are subdivided by carbonate-terrigenouse rocks (C-P2) of Khantaisko-Rybninsky swell . These two zones differ one from another by thickness of basalts and their composition.The fist zone extents along the Khatanga fault and contains all suits, including three lowest ones - ivakinsky (Iv), syverminsky (Sv), gudchikhinsky (Gd). II zone essentially consists of the middle and upper suits - hakanchansky (Hk), tuklonsky (Tk), nadezhdinsky (Nd), morongovsky (Mr), mokulaevsky (Mk), kharaekakhsky (Kh), kumginsky (Km) and samoedsky (Sm). Usually it is constructed the complete section of the Noril'sk volcanites from rocks of two zones. But every suit has its own areal extent., which to contour it not so easy because volcanic rocks represent very similar tholeiitic basalts ( in term of texture and petrochemistry). Their differentiation is just possible using rare elements and isotopes contents in the rocks [1]. We have studied a lot of basalt sections based on their outcrops and cores of drill holes (4 570 m) and intrusive bodies graduated in mineralization (internal structure, geochemistry, mineralogy, isotopes composition). According new data areoles of the lowers and the upper suits separate in space. The thicknesses Iv and Sv suits (TiO2=2-4 mas. %; Gg/Yb = 2.2.) decreases synchronously from NW Kharaelakh and the towards Putorana at 30%. Gd suit (TiO2=1-2 mas.% and Gd

  20. Upper Palaeolithic Siberian genome reveals dual ancestry of Native Americans

    DEFF Research Database (Denmark)

    Raghavan, Maanasa; Skoglund, Pontus; Graf, Kelly E.;

    2014-01-01

    The origins of the First Americans remain contentious. Although Native Americans seem to be genetically most closely related to east Asians, there is no consensus with regard to which specific Old World populations they are closest to. Here we sequence the draft genome of an approximately 24...... this ancient population. This is likely to have occurred after the divergence of Native American ancestors from east Asian ancestors, but before the diversification of Native American populations in the New World. Gene flow from the MA-1 lineage into Native American ancestors could explain why several crania......,000-year-old individual (MA-1), from Mal'ta in south-central Siberia, to an average depth of 1×. To our knowledge this is the oldest anatomically modern human genome reported to date. The MA-1 mitochondrial genome belongs to haplogroup U, which has also been found at high frequency among Upper Palaeolithic...

  1. Spin flip by RF-field at storage rings with siberian snakes

    Energy Technology Data Exchange (ETDEWEB)

    Koop, I.; Shatunov, Y. [Budker Institute for Nuclear Physics, Novosibirsk, 630090 (Russia)

    1995-09-01

    The beam dynamics and optics of spin flipping polarized beams with an RF field in storage rings with Siberian Snakes is discussed. The dispersion relations are determined and depolarization of the beams are discussed. (AIP) {copyright} {ital 1995 American Institute of Physics.}

  2. The Central European, Tarim and Siberian Large Igneous Provinces, Late Palaeozoic orogeny and coeval metallogeny

    NARCIS (Netherlands)

    de Boorder, H.

    2014-01-01

    The formation of the Central European and Tarim Large Igneous Provinces (LIPs) in the Early Permian coincided with the demise of the Variscan and the Southern Tianshan orogens, respectively. The Early Triassic Siberian LIP was formed in the wake of the Western Altaid orogeny in the Late Permian. The

  3. Estimation and extrapolation of soil properties in the Siberian tundra, using field spectroscopy

    NARCIS (Netherlands)

    Bartholomeus, H.; Schaepman-Strub, G.; Blok, D.; Udaltsov, S.; Sofronov, R.

    2010-01-01

    The Siberian tundra is a complex and sensitive ecosystem. Predicted global warming will be highest in the Arctic and will severely affect permafrost environments. Due to its large spatial extent and large stocks of soil organic carbon, changes to the carbon fluxes in the Arctic will have significant

  4. Plant metabolites of the Siberian flora. Chemical transformations and the scope of practical application

    Energy Technology Data Exchange (ETDEWEB)

    Shults, Elvira E; Raldugin, Victor A; Volcho, Konstantin P; Salakhutdinov, Nariman F; Tolstikov, Genrikh A [N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2007-07-31

    The results of studies of some terpenoids, alkaloids and phenolic derivatives isolated from Siberian plants are summarised. The structures of the compounds studied are presented and the chemical transformations of the available terpenoids and alkaloids are considered. Examples of practical application of natural compounds and their derivatives are given.

  5. Plant metabolites of the Siberian flora. Chemical transformations and the scope of practical application

    Science.gov (United States)

    Shults, Elvira E.; Raldugin, Victor A.; Volcho, Konstantin P.; Salakhutdinov, Nariman F.; Tolstikov, Genrikh A.

    2007-07-01

    The results of studies of some terpenoids, alkaloids and phenolic derivatives isolated from Siberian plants are summarised. The structures of the compounds studied are presented and the chemical transformations of the available terpenoids and alkaloids are considered. Examples of practical application of natural compounds and their derivatives are given.

  6. Why do few Afro-Siberian Knots Calidris canutus canutus now visit Britain?

    NARCIS (Netherlands)

    Boyd, H; Piersma, T

    2001-01-01

    The nominate (Afro-Siberian) subspecies of the Knot Calidris canutus canutus breeds on the Taimyr Peninsula in Siberia and occurs commonly in the westernmost Wadden Sea during migration to West and South Africa. The recoveries and controls of 2045 Knots ringed in Britain and Ireland provide no evide

  7. Combined effect of the East Atlantic/West Russia and Western Pacific teleconnections on the East Asian winter monsoon

    Science.gov (United States)

    Oh, Hyoeun; Jhun, Jong-Ghap; Ha, Kyung-Ja; Seo, Kyong-Hwan

    2017-05-01

    This study investigates the individual effects of the East Atlantic/West Russia (EATL/WRUS) and Western Pacific (WP) teleconnection patterns and their combined effect on the East Asian winter monsoon (EAWM). The contributions of the respective EATL/WRUS and WP teleconnection patterns to the EAWM are revealed by removing the dependence on the Arctic Oscillation (AO) and the El Niño-Southern Oscillation (ENSO) using a linear regression, which are named as N_EATL/WRUS and N_WP, respectively. This is because the EATL/WRUS (WP) is closely linked to the Arctic (tropics) region. A significant increase (decrease) in temperature over East Asia (EA) corresponding to a weak (strong) EAWM is associated with the N_EATL/WRUS and N_WP teleconnection patterns during the positive (negative) phases. In order to examine impacts of these two teleconnections on the EAWM, three types of effects are reconstructed on the basis of ± 0.5 standard deviation: 1) Combined effect, 2) N_EATL/WRUS effect, and 3) N_WP effect. The positive N_EATL/WRUS teleconnection induces to a weakened Siberian High and a shallow EA trough at the mid-troposphere through wave propagation, leading to the weak EAWM. During the positive N_WP pattern, warm air from the tropics flows toward the EA along western flank of an anomalous anticyclone over the North Pacific that is relevant to the meridional shift of the Aleutian Low. When the two mid-latitude teleconnections have the in-phase combination, the increase in temperature over EA appears to be more pronounced than the individual effects by transporting warm air from tropics via strong southeasterly wind anomalies induced by anomalous zonal pressure gradient between the Siberian High and Aleutian Low. Therefore, the impact of the mid-latitude teleconnections on the EAWM becomes robust and linearly superimposed, unlike a nonlinear in-phase combined effect of the AO and ENSO.

  8. Carbohydrate accumulation in the needles of Siberian stone pine seedlings

    Directory of Open Access Journals (Sweden)

    A. Panov

    2013-12-01

    Full Text Available The aim of the research presented is to study effects extracted from biologically active peat substances on carbohydrate accumulationprocesses. The study was carried out on 5-year-old Siberian stone pine seedlings grown in the nursery forest in the southern part of the Tomsk region. These seedlings were treated with a peat preparation, which was created in Tomsk. Four groups of experimental plants were organized on the analog principle. Each group consisted of 30 seedlings of average size and half of these seedlings were control. At the beginning of the vegetative season, a single treatment was applied to experimental plants with water solution peat preparation. The first group of plants was treated with a 0.1% solution; the dose was calculated by dry substance. For the second group, the dose was increased by 25%. For the third and fourth groups, the dose was decreased by 25% relative to the first group. Control plants were sprayed with water. Accumulation of carbohydrates and pigments as well as growth values in the 2-year- old needles were studied by standard methods. Glucose levels in the experimental plants existed within the limits 117-120%. On the whole, simple sugar quantity did not differs between experimental variants.Glucose synthesis was accompanied by changes in quantitative values of fructose. This, connected with glucose being a more stable compound, and compulsory conversion from glucose to labile form fructose was necessary. The amount of fructose in the experimental seedlings had a very wide range. This process was accompanied by shoot elongationin Siberian stone pine in the first year after treatment, with the fructose amount of 14% exceeding control values in the first and fourth group. Shoot growth was accompanied by increased fructose amount to 20% relative to control. A similar situation was observed afterwinter with respect to buds. Experimental plants dominated by number of buds

  9. Tracing of submarine groundwater discharge in the Siberian Arctic coastal zone: the case study in the Buor-Khaya Bay, Laptev Sea.

    Science.gov (United States)

    Charkin, A. N.; Dudarev, O.; Semiletov, I. P.; Shakhova, N. E.; Rutgers van der Loeff, M.; Salyuk, A.

    2015-12-01

    That is suggested and widely accepted that a significant portion of the Great Siberian Rivers discharge comes to the Arctic ocean via submarine groundwater discharge (SGD). However, that statement was never proofed by observations. When groundwater discharges from the coastal aquifer to the ocean, the radium isotopes are transported with the groundwater, and they can be measured to trace and quantify SGD, and the flux of constituents associated with SGD. The primary goal of this study is to use radium isotopes to proof that SGD is existing in the Laptev Sea coastal zone close to the Lena River delta, which supposed to be characterized by continuous permafrost with thickness up to 600-800m. If so, we supposed to quantify methane fluxes to the coastal ocean through SGD. Discrete seawater, and Lena river water samples were collected from different horizons from the holes made in fast ice using submerged pump and Niskin bottle in the western part of Buor- Khaya Bay in March-April 2014 and 2015. We identified and traced SGD using short-lived radium (224Ra and 223Ra) and radon (222Rn) isotopes in complex with geophysical (electromagnetic technique) , geological (sediment core results from 16 boreholes), hydrological (temperature, salinity), and hydrochemical (total alkalinity, dissolved methane and oxygen) data. It was found that the SGD is controlled by the processes associated with changing state of the subsea permafrost. Thus, this technique can give an unique information about the location of SGD "leakage" sites across the East Siberian Arctic Shelf, which represents > 80% of subsea permafrost existing in the entire Arctic ocean.

  10. Paleomagnetism of Siberian Trap Intrusions: Implications for the Timing and Intensity of the Magmatic Activity

    Science.gov (United States)

    Latyshev, Anton; Veselovskiy, Roman; Mirsayanova, Elina; Ulyahina, Polina

    2016-04-01

    Large Igneous Provinces (LIPs) are the areas of the exceptional interest due to associated Cu-Ni-Pt deposits, problems of the causal link between volcanic hazards and mass extinctions, and questions about mantle plume dynamics. High-precise U-Pb and 40Ar/39Ar dating determined the duration of the main phase of the most voluminous Siberian Trap province formation as 1-2 Ma (Kamo et al., 2003; Reichow et al., 2008). Recent paleomagnetic investigations demonstrated the predominance of pulsating volcanic activity during LIPs formation (Chenet et al., 2009; Pavlov et al., 2015). We perform the results of detailed paleomagnetic study of intrusive complexes from Tunguska syncline and Angara-Taseeva depression (Siberian Trap province). Our data taken together with the previous paleomagnetic results from trap intrusions revealed two different styles of magmatic activity. In the central part of Tunguska syncline emplacement of was rather even without sharp bursts. Local intrusive events coeval to volcanic eruptions took place within spatially limited areas. In contrast, in the periphery of Tunguska syncline several short and powerful peaks of magmatic activity happened on the background of weak prolonged magmatism. These events resulted in huge Padunsky, Tulunsky and some other sills in the southern part of the Siberian platform. According to our paleomagnetic data, the duration of such pulses did not exceed 10-100 thousand years. Taking into account our paleomagnetic data and recent U-Pb ages for Siberian trap intrusions from (Burgess, Bowring, 2015), it is possible to correlate intrusive complexes with the volcanic section. In particular, formation the largest Tulunsky and Padunsky sills happened right after the termination of the main phase of Permian-Triassic volcanic activity on the Siberian platform. This work was supported by grants RFBR # 16-35-60114 and 15-35-20599 and Ministry of Education and Science of the Russian Federation (grant 14.Z50.31.0017).

  11. Identification, expression, and physiological functions of Siberian hamster gonadotropin-inhibitory hormone.

    Science.gov (United States)

    Ubuka, Takayoshi; Inoue, Kazuhiko; Fukuda, Yujiro; Mizuno, Takanobu; Ukena, Kazuyoshi; Kriegsfeld, Lance J; Tsutsui, Kazuyoshi

    2012-01-01

    Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic neuropeptide that inhibits gonadotropin secretion in birds and mammals. To further understand its physiological roles in mammalian reproduction, we identified its precursor cDNA and endogenous mature peptides in the Siberian hamster brain. The Siberian hamster GnIH precursor cDNA encoded two RFamide-related peptide (RFRP) sequences. SPAPANKVPHSAANLPLRF-NH(2) (Siberian hamster RFRP-1) and TLSRVPSLPQRF-NH(2) (Siberian hamster RFRP-3) were confirmed as mature endogenous peptides by mass spectrometry from brain samples purified by immunoaffinity chromatography. GnIH mRNA expression was higher in long days (LD) compared with short days (SD). GnIH mRNA was also highly expressed in SD plus pinealectomized animals, whereas expression was suppressed by melatonin, a nocturnal pineal hormone, administration. GnIH-immunoreactive (-ir) neurons were localized to the dorsomedial region of the hypothalamus, and GnIH-ir fibers projected to hypothalamic and limbic structures. The density of GnIH-ir perikarya and fibers were higher in LD and SD plus pinealectomized hamsters than in LD plus melatonin or SD animals. The percentage of GnRH neurons receiving close appositions from GnIH-ir fiber terminals was also higher in LD than SD, and GnIH receptor was expressed in GnRH-ir neurons. Finally, central administration of hamster RFRP-1 or RFRP-3 inhibited LH release 5 and 30 min after administration in LD. In sharp contrast, both peptides stimulated LH release 30 min after administration in SD. These results suggest that GnIH peptides fine tune LH levels via its receptor expressed in GnRH-ir neurons in an opposing fashion across the seasons in Siberian hamsters.

  12. Influence of contemporary carbon originating from the 2003 Siberian forest fire on organic carbon in PM{sub 2.5} in Nagoya, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Ikemori, Fumikazu, E-mail: ikemori@nagoyakankaken.net [Nagoya City Institute for Environmental Sciences, 5-16-8, Toyoda, Minami-ku, Nagoya 457-0841 (Japan); Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464–8601 (Japan); Honjyo, Koji [Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464–8601 (Japan); Yamagami, Makiko [Nagoya City Institute for Environmental Sciences, 5-16-8, Toyoda, Minami-ku, Nagoya 457-0841 (Japan); Nakamura, Toshio [Centre for Chronological Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

    2015-10-15

    In May 2003, high concentrations of organic carbon (OC) in PM{sub 2.5} were measured in Nagoya, a representative metropolitan area in Japan. To investigate the influence of possible forest fires on PM{sub 2.5} in Japan via long-range aerosol transport, the radiocarbon ({sup 14}C) concentrations of PM{sub 2.5} samples from April 2003 to March 2004 were measured. {sup 14}C concentrations in total carbon (TC) from May to early June showed higher values than those in other periods. The OC/elemental carbon (EC) ratios from May to early June were also significantly higher than the ones in other periods. In addition, OC concentrations from May to early June were typically high. These results indicate that the abundant OC fraction from May to early June in Nagoya consisted predominantly of contemporary carbon. Furthermore, simulations of diffusion and transport of organic matter (OM) in East Asia showed that abundant OM originating from East Siberia spread over East Asia and Japan in May and early June. Backward air mass trajectories from this time frame indicate that the air mass in Nagoya likely first passed through East Siberia where fire events were prevalent. However, the backward trajectories showed that the air mass after early June did not originate mainly from Siberia, and correspondingly, the {sup 14}C and OC concentrations showed lower values than those from May to early June. Therefore, the authors conclude that contemporary carbon originating from the forest fire in East Siberia was transported to Nagoya, where it significantly contributed to the high observed concentrations of both OC and {sup 14}C. - Highlights: • We analyzed the radiocarbon ({sup 14}C) concentration of TC in PM{sub 2.5} from Nagoya, Japan. • {sup 14}C concentrations from May to early June in 2003 were elevated. • The air mass at this time in Nagoya likely first passed through East Siberia. • Fire location data from MODIS indicate that fire events were prevalent in East Siberia.

  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)

    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. PMID:28178351

  14. 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.

  15. Co-infection of the Siberian hamster (Phodopus sungorus) with a novel Helicobacter sp. and Campylobacter sp.

    Science.gov (United States)

    Nagamine, Claude M; Shen, Zeli; Luong, Richard H; McKeon, Gabriel P; Ruby, Norman F; Fox, James G

    2015-05-01

    We report the isolation of a novel helicobacter isolated from the caecum of the Siberian hamster (Phodopus sungorus). Sequence analysis showed 97% sequence similarity to Helicobacter ganmani. In addition, we report the co-infection of these Siberian hamsters with a Campylobacter sp. and a second Helicobacter sp. with 99% sequence similarity to Helicobacter sp. flexispira taxon 8 (Helicobacter bilis), a species isolated previously from patients with bacteraemia. Gross necropsy and histopathology did not reveal any overt pathological lesions of the liver and gastrointestinal tract that could be attributed to the Helicobacter or Campylobacter spp. infections. This is the first helicobacter to be identified in the Siberian hamster and the first report of co-infection of Helicobacter spp. and Campylobacter sp. in asymptomatic Siberian hamsters.

  16. Layering of the lithospheric mantle beneath the Siberian Craton: Modeling using thermobarometry of mantle xenolith and xenocrysts

    Science.gov (United States)

    Ashchepkov, I. V.; Vladykin, N. N.; Ntaflos, T.; Kostrovitsky, S. I.; Prokopiev, S. A.; Downes, H.; Smelov, A. P.; Agashev, A. M.; Logvinova, A. M.; Kuligin, S. S.; Tychkov, N. S.; Salikhov, R. F.; Stegnitsky, Yu. B.; Alymova, N. V.; Vavilov, M. A.; Minin, V. A.; Babushkina, S. A.; Ovchinnikov, Yu. I.; Karpenko, M. A.; Tolstov, A. V.; Shmarov, G. P.

    2014-11-01

    Single-grain thermobarometric studies of xenocrysts were used to compile local SCLM transects through the major regions of kimberlite magmatism in Siberia and longer transects through the subcontinental mantle lithosphere (SCLM) beneath the Siberian craton. The mantle structure was obtained using P-Fe#, Ca in garnets, oxygen fugacity values fO2 and calculated temperatures T°C. The most detail transect obtained for the Daldyn field on the Udachnaya-Zarnitsa reveals layering showing an inclination of > 35° to Udachnaya. Mantle layering beneath the Alakit field determined from the Krasnopresnenskaya-Sytykanskaya transect shows a moderate inclination from N to S. The inflection near Yubileinaya-Aykhal is also supported by the extreme depletion in peridotites with low-Fe sub-Ca garnets. Beneath the Malo-Botuobinsky field the sharply layered mantle section starts from 5.5 GPa and reveals step-like P-Fe#Ol trends for garnets and ilmenites. The deeper part of SCLM in this field was originally highly depleted but has been regenerated by percolation of protokimberlites and hybrid melts especially beneath Internationalnaya pipe. The three global transects reveal flat layering in granite-greenstone terranes and fluctuations in the granulite-orthogneiss Daldyn collision terranes. The mantle layering beneath the Daldyn - Alakite region may have been created by marginal accretion. Most of southern fields including the Malo-Botuobinsky field reveal flat layering. The primary subduction layering is smoothed beneath the Alakit field. Lower Jurassic kimberlites from the Kharamai-Anabar kimberlite fields reveal a small decrease of the thickness of the SCLM and heating of its base. The Jurassic Kuoyka field shows an uneven base of the SCLM inclined from west to east. SCLM sequences sampled at this time started mainly from depths of 130 km, but some pipes still showed mantle roots to 250 km. The garnet series demonstrates an inclined straight line pyroxenite P-Fe# trend due to

  17. The impact of political decisions on sustainable urban development (case study of Siberian cities during the Russo-Japanese war)

    Science.gov (United States)

    Ageev, Ilya A.; Ageeva, Vera V.; Bleikher, Oksana V.; Larionova, Alyona V.

    2017-01-01

    The paper examines the impact of public-political factors on the regional sustainable development in the light of the historical experience of the Siberian cities during the Russo-Japanese war (1904-1905). Based on the analysis of archival materials and publications in the Siberian printed press at the beginning of the 20th century, the authors have identified the reasons why the sustainable development of the largest Siberian cities was hindered at that period. The construction of the railway eliminated the problem of transport links with Siberian cities; however it made them dependent on external supply of goods. Local Siberian production declined with the advent of cheap imported goods; warehouse infrastructure reduced due to the uselessness; the alternative modes of transport could not compete with the railroad and left the main traffic directions. The Russo-Japanese war began in 1904 and left Tomsk, Krasnoyarsk and Irkutsk without transport service for nearly eighteen months, since cargo railway transportation which was not related to the supply of the army, was discontinued. Siberian cities were in catastrophic conditions: food prices increased several times, hospitals worked without pharmaceuticals, urban construction was stopped. Historical examples of unsatisfactory supply of cities under the influence of intense public and political factors demonstrate that sustainable urban development is impossible without the diversification of the sources and means of subsistence. Diversification is proved to be necessary, it can guarantee the use of the transport and economic infrastructure in the interests of the city in unexpected situations.

  18. Upper Palaeolithic Siberian genome reveals dual ancestry of Native Americans

    DEFF Research Database (Denmark)

    Raghavan, Maanasa; Skoglund, Pontus; Graf, Kelly E.

    2014-01-01

    ,000-year-old individual (MA-1), from Mal'ta in south-central Siberia, to an average depth of 1×. To our knowledge this is the oldest anatomically modern human genome reported to date. The MA-1 mitochondrial genome belongs to haplogroup U, which has also been found at high frequency among Upper Palaeolithic......The origins of the First Americans remain contentious. Although Native Americans seem to be genetically most closely related to east Asians, there is no consensus with regard to which specific Old World populations they are closest to. Here we sequence the draft genome of an approximately 24...... that the region was continuously occupied by humans throughout the Last Glacial Maximum. Our findings reveal that western Eurasian genetic signatures in modern-day Native Americans derive not only from post-Columbian admixture, as commonly thought, but also from a mixed ancestry of the First Americans....

  19. A minimum UPb age for Siberian flood-basalt volcanism

    Science.gov (United States)

    Kamo, S. L.; Czamanske, G. K.; Krogh, T. E.

    1996-09-01

    Establishing an accurate and precise age for Siberian flood-basalt volcanism is of great importance in evaluating causes for the unequaled mass extinction of flora and fauna at the Permian-Triassic boundary. We report a new, minimum UPb age obtained from zircon and baddeleyite from the mineralized Noril'sk I intrusion that cuts the lower third of this rapidly deposited, 3500-m-thick volcanic sequence near Noril'sk. This 251.2 ± 0.3 (2σ) Ma age is within analytical error of the SHRIMP UPb age for zircon from the Permian-Triassic boundary at Meishan, South China [251.1 ± 3.6 Ma (2σ)], and confirms Siberian basaltic volcanism as a possible contributor to the mass extinction.

  20. A minimum U-Pb age for Siberian flood-basalt volcanism

    Science.gov (United States)

    Kamo, S.L.; Czamanske, G.K.; Krogh, T.E.

    1996-01-01

    Establishing an accurate and precise age for Siberian flood-basalt volcanism is of great importance in evaluating causes for the unequaled mass extinction of flora and fauna at the Permian-Triassic boundary. We report a new, minimum U-Pb age obtained from zircon and baddeleyite from the mineralized Noril'sk I intrusion that cuts the lower third of this rapidly deposited, 3500-m-thick volcanic sequence near Noril'sk. This 251.2 ?? 0.3 (2??) Ma age is within analytical error of the SHRIMP U-Pb age for zircon from the Permian-Triassic boundary at Meishan, South China [251.1 ?? 3.6 Ma (2??)], and confirms Siberian basaltic volcanism as a possible contributor to the mass extinction.

  1. Trouble Upstairs: Reconstructing Permian-Triassic Climate during Siberian Traps Magmatism

    Science.gov (United States)

    Black, B. A.; Neely, R. R., III; Lamarque, J. F.; Elkins-Tanton, L. T.; Mills, M. J.

    2014-12-01

    The eruption of large igneous provinces can transfer significant masses of volatiles from Earth's interior to the atmosphere. What are the consequences of this degassing for habitability and extinction? In this presentation, we consider this question in the context of Siberian Traps magmatism, which has been shown to overlap within geochronologic uncertainty with catastrophic deterioration of Permian-Triassic marine and terrestrial ecosystems. To investigate the impacts of endogenic gases on climate, atmospheric chemistry, and ocean circulation, we conducted a series of numerical experiments with a comprehensive global model for the Permian-Triassic. Our simulations predict the intensity and distribution of acid rain and ozone depletion, with implications for terrestrial biota. We further explore feedbacks between sulfur emissions, transient cooling, and shifts in ocean circulation. We suggest that Siberian Traps magmatism may have triggered several distinct kill mechanisms in the oceans and on land, contributing to a complex combined pattern of environmental stress and latest Permian ecological failure.

  2. Establishment and Characterization of Fibroblast Cell Line Derived from Siberian Tiger (Panthera tigris altaica).

    Science.gov (United States)

    Liu, Changqing; Guo, Yu; Liu, Dan; Guan, Weijun; Ma, Yuehui

    2010-06-01

    The Siberian tiger ear marginal tissue fibroblast cell line (STF34) from 34 samples was successfully established using primary explants technique and cell cryoconservation technology. STF34 cells were adherent, with a population doubling time of 24 h. Chromosome analysis showed that 90.2%-91.6% of cells were diploid (2n = 38). Isoenzyme analyses of lactate dehydrogenase and malate dehydrogenase showed that STF34 cells had no cross-contamination with other species. Tests for cell line contamination with bacteria, fungi, viruses, and mycoplasmas were all negative. Every index of the STF34 cell line meets all the standard quality controls of American Type Culture Collection. Not only has the germline of this important Siberian tiger species been preserved at the cell level, but also valuable material had been provided for genome, postgenome, and somacloning research.

  3. The deep structures of the junction of the Urals with the Russian and West Siberian Platforms

    Science.gov (United States)

    Ivanov, K. S.; Koroteev, V. A.; Kostrov, N. P.

    2017-07-01

    A new model of the junction of the Ural fold belt with the Russian and West Siberian Platforms along the Europrobe Seismic Reflection profiling in the Urals (ESRU) down to a depth of 15 km is constructed. 2Dmodeling of the density and magnetic properties was performed using seven profiles and was accompanied by an estimate of applicability of the method. In the west, the upper part of the model is represented by terrigeneous- carbonate deposits, and the bottom part shows the structures of the basement of the Russian platform, which becomes thinner eastward and plunges beneath the Ural structures. The most significant difference in the West Siberian part of the transect is the great "length" of the entire structure of the Earth's crust. This is caused by the Early Triassic extension accompanied by the formation of a system of Triassic graben-rifts.

  4. Neuropeptides and anticipatory changes in behaviour and physiology: seasonal body weight regulation in the Siberian hamster.

    Science.gov (United States)

    Mercer, Julian G; Tups, Alexander

    2003-11-01

    The Siberian hamster, Phodopus sungorus, is a powerful model of physiological body weight regulation. This seasonal model offers the potential to distinguish between the compensatory neuroendocrine systems that defend body weight against imposed negative energy balance, and those that are involved in the programming of the level of body weight that will be defended-a seasonally appropriate body weight. Of the known, studied, components of the hypothalamic energy balance system, the anorexogenic peptide, cocaine- and amphetamine-regulated transcript (CART), is the only candidate where gene expression changes in a manner consistent with a role in initiating or sustaining photoperiod-induced differences in body weight trajectory. Siberian hamsters effect a reversible biannual switch in leptin sensitivity in which only short day (SD)-acclimated hamsters that have undergone a reduction in body weight, adiposity and plasma leptin are sensitive to peripheral exogenous leptin. The suppressor of cytokine signalling protein, SOCS3, appears to be the molecular correlate of this seasonal sensitivity.

  5. Siberian Regional Identity in the Context of Historical Consciousness (Content Analysis of Tomsk Regional Media

    Directory of Open Access Journals (Sweden)

    A V Bocharov

    2011-12-01

    Full Text Available The article presents a model to study the Siberian regional identity in the context of historical consciousness, as well as the results of its practical application in the content analysis of the publications by the Tomsk regional media. On the basis of the content analysis procedures the author demonstrates how, through historical memory, the regional identity is formed and manifested in the regional media in various spheres of society.

  6. Green synthesis of multifunctional silver and gold nanoparticles from the oriental herbal adaptogen: Siberian ginseng.

    Science.gov (United States)

    Abbai, Ragavendran; Mathiyalagan, Ramya; Markus, Josua; Kim, Yeon-Ju; Wang, Chao; Singh, Priyanka; Ahn, Sungeun; Farh, Mohamed El-Agamy; Yang, Deok Chun

    2016-01-01

    Pharmacologically active stem of the oriental herbal adaptogen, Siberian ginseng, was employed for the ecofriendly synthesis of Siberian ginseng silver nanoparticles (Sg-AgNPs) and Siberian ginseng gold nanoparticles (Sg-AuNPs). First, for metabolic characterization of the sample, liquid chromatography-tandem mass spectrometry analysis (indicated the presence of eleutherosides A and E), total phenol content, and total reducing sugar were analyzed. Second, the water extract of the sample mediated the biological synthesis of both Sg-AgNPs and Sg-AuNPs that were crystalline face-centered cubical structures with a Z-average hydrodynamic diameter of 126 and 189 nm, respectively. Moreover, Fourier transform infrared analysis indicated that proteins and aromatic hydrocarbons play a key role in the formation and stabilization of Sg-AgNPs, whereas phenolic compounds accounted for the synthesis and stability of Sg-AuNPs. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay determined that Sg-AgNPs conferred strong cytotoxicity against MCF7 (human breast cancer cell line) and was only slightly toxic to HaCaT (human keratinocyte cell line) at 10 µg⋅mL(-1). However, Sg-AuNPs did not display cytotoxic effects against both of the cell lines. The disc diffusion assay indicated a dose-dependent increase in the zone of inhibition of Staphylococcus aureus (ATCC 6538), Bacillus anthracis (NCTC 10340), Vibrio parahaemolyticus (ATCC 33844), and Escherichia coli (BL21) treated with Sg-AgNPs, whereas Sg-AuNPs did not show inhibitory activity. In addition, the 2,2-diphenyl-1-picrylhydrazyl assay demonstrated that both Sg-AgNPs and Sg-AuNPs possess strong antioxidant activity. To the best of our knowledge, this is the first report unraveling the potential of Eleutherococcus senticosus for silver and gold nanoparticle synthesis along with its biological applications, which in turn would promote widespread usage of the endemic Siberian ginseng.

  7. Histopathological effects of silver and copper nanoparticles on the epidermis, gills, and liver of Siberian sturgeon.

    Science.gov (United States)

    Ostaszewska, Teresa; Chojnacki, Maciej; Kamaszewski, Maciej; Sawosz-Chwalibóg, Ewa

    2016-01-01

    The influence of nanoparticles (NPs) on aquatic environments is still poorly documented. The aim of the study was to determine the effects of silver (AgNPs) and copper (CuNPs) nanoparticles on larval Siberian sturgeon (Acipenser baerii) after 21 days of exposure. Acute toxicity of AgNPs on Siberian sturgeon was investigated in a 96-h static renewal study and compared with the toxicity of CuNPs. The AgNPs and CuNPs 96 h mean lethal concentrations (96 h LC50) were 15.03 ± 2.91 and 1.41 ± 0.24 mg L(-1), respectively. Toxicity tests were done in triplicates for each concentration of AgNPs 0.1, 0.5, 1.5 mg L(-1) and CuNPs 0.01, 0.05, 0.15 mg L(-1). The control group was exposed in freshwater. The results indicate that AgNPs and CuNPs exposure negatively influenced survival; body length and mass; and morphology and physiology of the epidermis, gills, and liver of Siberian sturgeon larvae. Fish exposed to AgNPs and CuNPs showed similar pathological changes: irregular structure and pyknotic nuclei of epidermis, aplasia and/or fusion of lamellae, telangiectasis, epithelial necrosis and lifting of the gills, dilation of sinusoidal space, overfilled blood vessels, and pyknotic nuclei of the liver. Fish exposed to CuNPs only demonstrated hyaline degeneration in the gills epithelium and liver. The study shows that CuNPs were more toxic to Siberian sturgeon larvae than AgNPs.

  8. Analysis of spin flip data in rings with nearly full Siberian Snakes

    Energy Technology Data Exchange (ETDEWEB)

    Mane, S.R. [Convergent Computing Inc., P.O. Box 561, Shoreham, NY 11786 (United States)], E-mail: srmane@optonline.net

    2009-04-01

    I calculate theoretical values to fit experimental measurements of spin flip resonance widths in rings with nearly full strength Siberian Snakes. Some measurements were made using an rf solenoid, and others using vertical field rf dipoles. In particular, the staff of the MIT-Bates Linear Accelerator Laboratory kindly made available to me additional unpublished data for the spin flipping of stored polarized electrons at 850 MeV using a vertical field rf dipole spin flipper.

  9. Assessment of undiscovered oil and gas resources of the West Siberian Basin Province, Russia, 2010

    Science.gov (United States)

    Klett, T.R.

    2011-01-01

    The U.S. Geological Survey, using a geology-based assessment methodology, estimated mean volumes of technically recoverable, conventional, undiscovered petroleum resources at 8 billion barrels of crude oil, 670 trillion cubic feet of natural gas, and 21 billion barrels of natural gas liquids for the West Siberian Basin Province in Russia as part of a program to estimate petroleum resources for priority basins throughout the world.

  10. Free Electron Laser For The Siberian Centre For Photochemical Research The Control System

    CERN Document Server

    Avlasov, Y K; Miginskaya, E G; Oreshkov, A D; Ovchar, A V; Salikova, T V; Selivanov, P A; Serednyakov, S I; Tararyshkin, S V; Tribendis, A G; Vinokurov, N A

    2004-01-01

    This article describes the software for the control system of the Free Electron Laser for the Siberian Center for photochemical research. The main components of subsystems composing the control system as well as their hardware and software components are considered. Also main features of each of the subsystems and of the whole control system are mentioned. The prospects of control system development to meet the future requirements are discussed.

  11. First lasing at the high-power free electron laser at Siberian center for photochemistry research

    Science.gov (United States)

    Antokhin, E. A.; Akberdin, R. R.; Arbuzov, V. S.; Bokov, M. A.; Bolotin, V. P.; Burenkov, D. B.; Bushuev, A. A.; Veremeenko, V. F.; Vinokurov, N. A.; Vobly, P. D.; Gavrilov, N. G.; Gorniker, E. I.; Gorchakov, K. M.; Grigoryev, V. N.; Gudkov, B. A.; Davydov, A. V.; Deichuli, O. I.; Dementyev, E. N.; Dovzhenko, B. A.; Dubrovin, A. N.; Evtushenko, Yu. A.; Zagorodnikov, E. I.; Zaigraeva, N. S.; Zakutov, E. M.; Erokhin, A. I.; Kayran, D. A.; Kiselev, O. B.; Knyazev, B. A.; Kozak, V. R.; Kolmogorov, V. V.; Kolobanov, E. I.; Kondakov, A. A.; Kondakova, N. L.; Krutikhin, S. A.; Kryuchkov, A. M.; Kubarev, V. V.; Kulipanov, G. N.; Kuper, E. A.; Kuptsov, I. V.; Kurkin, G. Ya.; Labutskaya, E. A.; Leontyevskaya, L. G.; Loskutov, V. Yu.; Matveenko, A. N.; Medvedev, L. E.; Medvedko, A. S.; Miginsky, S. V.; Mironenko, L. A.; Motygin, S. V.; Oreshkov, A. D.; Ovchar, V. K.; Osipov, V. N.; Persov, B. Z.; Petrov, S. P.; Petrov, V. M.; Pilan, A. M.; Poletaev, I. V.; Polyanskiy, A. V.; Popik, V. M.; Popov, A. M.; Rotov, E. A.; Salikova, T. V.; Sedliarov, I. K.; Selivanov, P. A.; Serednyakov, S. S.; Skrinsky, A. N.; Tararyshkin, S. V.; Timoshina, L. A.; Tribendis, A. G.; Kholopov, M. A.; Cherepanov, V. P.; Shevchenko, O. A.; Shteinke, A. R.; Shubin, E. I.; Scheglov, M. A.

    2004-08-01

    The first lasing near wavelength 140 μm was achieved in April 2003 on a high-power free electron laser (FEL) constructed at the Siberian Center for Photochemical Research. In this paper, we briefly describe the design of FEL driven by an accelerator-recuperator. Characteristics of the electron beam and terahertz laser radiation, obtained at the first experiments, are also presented in the paper.

  12. Architectural Trend of the Epoch: Architect Chernyshev as a bright representative of the Siberian Modern

    OpenAIRE

    Olga Uspenskaya

    2016-01-01

    The article is about a bright representative of the Siberian Modern, Leonid Alexandrovich Chernyshev, who made a great contribution to the development of Krasnoyarsk city architecture. On the initiative of the Board of the Krasnoyarsk regional organization of the Union of Architects of Russia the year 2015 in Krasnoyarsk was announced the Year of the Architect Chernyshev to commemorate his 140th anniversary. During the anniversary year several important events will be held to demonstrate the ...

  13. III STATE DUMA IN ESTIMATIONS OF SIBERIAN SOCIALISTS-REVOLUTIONARIES (ON MATERIALS OF ILLEGAL PRESS

    Directory of Open Access Journals (Sweden)

    N. P. KURUSKANOVA

    2016-01-01

    Full Text Available In article on basis of published and archival documents, research literature estimations given by an illegal press of Siberian organizations of PSR, to various aspects of activity of III State Duma per 1907-1912 are considered. On the basis of studying illegal editions of socialists-revolutionaries author has found out their position in relation to elections in Duma of third convocation. In article illegal editions of Siberian socialists-revolutionaries, describing social and party structure of the deputy case, prominent representatives of different fractions, and their behavior within precincts of parliament are quoted. The maintenance of editions of Siberian socialists-revolutionaries, various parties of legislative activity of III Duma, devoted to estimations is in detail stated: statement of state budget, agrarian and working legislation, etc. Estimations of socialists-revolutionaries to P.A. Stolypin’s agrarian transformations are resulted. The reasons of accrued indifferent attitude of population to activity of III Duma are opened. In article it is drawn a conclusion, that Siberian socialists-revolutionaries in illegal press III Dumas dominated over it conservative ideas have adequately enough estimated social and party structure, progovernmental orientation of majority of deputies, slipping to right positions of cadets. In opinion of members of PSR, Russian parliament practically did not represent broad masses of population. Esser’s authors considered not productive legislative activity of Duma, fairly marking, that III Duma has not managed to execute main task – to express political will of population in form of legislation. Therefore in all editions socialists-revolutionaries called citizens to struggle for Constituent assembly which, in their opinion, could resolve all national needs.

  14. Maternal pinealectomy increases depressive-like responses in Siberian hamster offspring.

    Science.gov (United States)

    Workman, Joanna L; Weil, Zachary M; Tuthill, Christiana R; Nelson, Randy J

    2008-06-01

    This study investigated the effect of maternal pinealectomy and postnatal pinealectomy on affective responses. Siberian hamsters were born to either pinealectomized or sham-operated dams and then underwent pinealectomy or a sham operation. Maternal pinealectomy increased depressive-like responses of offspring in the forced swim test. Maternal pinealectomy increased rearing behaviour and postnatal pinealectomy increased locomotor behaviour in the open field test. These results suggest that prenatal melatonin organizes adult affective responses.

  15. Hypothalamic gene expression rapidly changes in response to photoperiod in juvenile Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    Herwig, A; Petri, I; Barrett, P

    2012-07-01

    Siberian hamsters are seasonal mammals that survive a winter climate by making adaptations in physiology and behaviour. This includes gonadal atrophy, reduced food intake and body weight. The underlying central mechanisms responsible for the physiological adaptations are not fully established but involve reducing hypothalamic tri-iodthyronine (T3) levels. Juvenile Siberian hamsters born or raised in short days (SD) respond in a similar manner, although with an inhibition of gonadal development and growth instead of reversing an established long day (LD) phenotype. Using juvenile male hamsters, the present study aimed to investigate whether the central mechanisms are similar before the establishment of the mature LD phenotype. By in situ hybridisation, we examined the response of genes involved in thyroid hormone (Dio2 and Dio3, which determine hypothalamic T3 levels) and glucose/glutamate metabolism in the ependymal layer, histamine H3 receptor and VGF as representatives of the highly responsive dorsomedial posterior arcuate nucleus (dmpARC), and somatostatin, a hypothalamic neuropeptide involved in regulating the growth axis. Differential gene expression of type 2 and type 3 deiodinase in the ependymal layer, histamine H3 receptor in the dmpARC and somatostatin in the ARC was established by the eighth day in SD. These changes are followed by alterations in glucose metabolism related genes in the ependymal layer by day 16 and increased secretogranin expression in the dmpARC by day 32. In conclusion, our data demonstrate similar but rapid and highly responsive changes in gene expression in the brain of juvenile Siberian hamsters in response to a switch from LD to SD. The data also provide a temporal definition of gene expression changes relative to physiological adaptations of body weight and testicular development and highlight the likely importance of thyroid hormone availability as an early event in the adaptation of physiology to a winter climate in juvenile

  16. Cholecystokinin-33 acutely attenuates food foraging, hoarding and intake in Siberian hamsters.

    Science.gov (United States)

    Teubner, Brett J W; Bartness, Timothy J

    2010-04-01

    Neurochemicals that stimulate food foraging and hoarding in Siberian hamsters are becoming more apparent, but we do not know if cessation of these behaviors is due to waning of excitatory stimuli and/or the advent of inhibitory factors. Cholecystokinin (CCK) may be such an inhibitory factor as it is the prototypic gastrointestinal satiety peptide and is physiologically important in decreasing food intake in several species including Siberian hamsters. Systemic injection of CCK-33 in laboratory rats decreases food intake, doing so to a greater extent than CCK-8. We found minimal effects of CCK-8 on food foraging and hoarding previously in Siberian hamsters, but have not tested CCK-33. Therefore, we asked: Does CCK-33 decrease normal levels or food deprivation-induced increases in food foraging, hoarding and intake? Hamsters were housed in a wheel running-based foraging system with simulated burrows to test the effects of peripheral injections of CCK-33 (13.2, 26.4, or 52.8 microg/kg body mass), with or without a preceding 56 h food deprivation. The highest dose of CCK-33 caused large baseline reductions in all three behaviors for the 1st hour post-injection compared with saline; in addition, the intermediate CCK-33 dose was sufficient to curtail food intake and foraging during the 1st hour. In food-deprived hamsters, we used a 52.8 microg/kg body mass dose of CCK-33 which decreased food intake, hoarding, and foraging almost completely compared with saline controls for 1h. Therefore, CCK-33 appears to be a potent inhibitor of food intake, hoarding, and foraging in Siberian hamsters.

  17. Environmental Hazard Identification Technique Developing of Territorial Administrations Strategy as Exemplified in Siberian Federal District

    Science.gov (United States)

    Timofeeva, S. S.; Garmishev, V. V.; Lugovtsova, N. Yu

    2016-04-01

    This work, on the example of the Siberian Federal District of the Russian Federation, presents a method for determining mass airbursts of combustion gaseous eco-toxicants, as a technique for assessing the contributory environmental load on the atmosphere. Potential environmental hazards are analyzed by mass of contaminated airbursts. A comparison of specific gross toxicants’ emissions in territorial entities of the Russian Federation is made.

  18. The Complex Admixture History and Recent Southern Origins of Siberian Populations.

    Science.gov (United States)

    Pugach, Irina; Matveev, Rostislav; Spitsyn, Viktor; Makarov, Sergey; Novgorodov, Innokentiy; Osakovsky, Vladimir; Stoneking, Mark; Pakendorf, Brigitte

    2016-07-01

    Although Siberia was inhabited by modern humans at an early stage, there is still debate over whether it remained habitable during the extreme cold of the Last Glacial Maximum or whether it was subsequently repopulated by peoples with recent shared ancestry. Previous studies of the genetic history of Siberian populations were hampered by the extensive admixture that appears to have taken place among these populations, because commonly used methods assume a tree-like population history and at most single admixture events. Here we analyze geogenetic maps and use other approaches to distinguish the effects of shared ancestry from prehistoric migrations and contact, and develop a new method based on the covariance of ancestry components, to investigate the potentially complex admixture history. We furthermore adapt a previously devised method of admixture dating for use with multiple events of gene flow, and apply these methods to whole-genome genotype data from over 500 individuals belonging to 20 different Siberian ethnolinguistic groups. The results of these analyses indicate that there have been multiple layers of admixture detectable in most of the Siberian populations, with considerable differences in the admixture histories of individual populations. Furthermore, most of the populations of Siberia included here, even those settled far to the north, appear to have a southern origin, with the northward expansions of different populations possibly being driven partly by the advent of pastoralism, especially reindeer domestication. These newly developed methods to analyze multiple admixture events should aid in the investigation of similarly complex population histories elsewhere.

  19. “The History and Culture of the Western Siberian Tatars”: Some Notes about the Book

    Directory of Open Access Journals (Sweden)

    Z.A. Tychinskikh

    2017-03-01

    Full Text Available The article presents a collective monograph “The History and Culture of the Western Siberian Tatars” published in 2015 by Sh. Marjani Institute of History of Tatarstan Academy of Sciences. This book is the first academic work, which integrated and multidimensionally accumulated almost all materials (of demography, genetics, linguistics, history, ethnography and ethnosociology available in modern science related to the formation and development of the Turkic-Tatar population of Western Siberia from ancient times to the early 21st century. The monograph is distinguished by the ethnoterritorial approach: the authors focus on the entire Turkic-Tatar population of Western Siberia, which was formed in different historical periods and includes two main components – population called in ethnographic science the “Siberian Tatars” and the group of Tatars who migrated (mainly from the Volga region to the Siberian region during the 16th–20th centuries. The book contains a large number of illustrations, which were collected during the expeditions of the authors in the rural settlements of the Tatars of Western Siberia, during archaeological excavations, in numerous archives and museums in Russia. Many photos are presented for the first time.

  20. [HYGIENIC ASSESSMENT OF WORKING CONDITIONS AND HEALTH OF EMPLOYEES OF THE "SIBERIAN LIFT CO., LTD."].

    Science.gov (United States)

    Rodkin, V P; Usatov, A N

    2015-01-01

    There was carried out a hygienic assessment of the working conditions and health of employees of the "Siberian Lift Co., Ltd.". When studying occupational factors on workplaces intensity, the temperature radiation, natural and artificial lighting, and also the content of chemicals they were revealed to fail to answer to the hygienic specifications. It is established that in 82% of employees the class of working conditions was detected as admissible (2) and in 18%--harmful (3.1 and 3.2). Results of the performed periodic medical examination of employees of the "Siberian Lift Co., Ltd.". It is testified that 6.14% out of them are persistently unfit of the work with harmful and (or) dangerous substances and occupational factors also. 4.68% of employees demand an additional examination. 11,70% of workers need for out-patient examination and treatment. Sanatorium treatment is required for 1 (0.29%) the person. 4,68% of employees of the "Siberian Lift Co., Ltd." need dispensary supervision. There are suggested measures for the improvement of working conditions and health of the employees.

  1. Male-induced estrus synchronization in the female Siberian hamster (Phodopus sungorus sungorus).

    Science.gov (United States)

    Dodge, James C; Kristal, Mark B; Badura, Lori L

    2002-11-01

    Olfactory cues play an integral role in the organization of events that mediate reproductive success. In a variety of species, priming pheromones, in particular, are important for ensuring reproductive fitness. To date, very little research has focused on how male-emitted priming pheromones, such as those that regulate the onset of puberty and estrus synchronization in females, affect the reproductive physiology of the female Siberian hamster (Phodopus sungorus sungorus). This lack of research may be due to the physiology of the Phodopus genus; vaginal cytology cannot be used as a reliable indicator of estrus or ovulation. Using a jugular cannulation technique to determine estrous stage by blood analysis of prolactin and luteinizing hormone, we sought to determine if male priming pheromones affect estrous cyclicity in the female Siberian hamster and, if so, whether the production of these priming pheromones is androgen dependent. Our results showed that females exposed to bedding from mature, intact males showed a significantly higher incidence of proestrus 3 days later than did females exposed to the bedding of mature, gonadectomized males. Therefore, we found that not only do male Siberian hamsters emit chemical signals that induce estrus synchronization, but also that this ability is likely to be androgen dependent.

  2. Preliminary Results of De Novo Whole Genome Sequencing of the Siberian Larch (Larix sibirica Ledeb. and the Siberian Stone Pine (Pinus sibirica Du Tour

    Directory of Open Access Journals (Sweden)

    K. V. Krutovsky

    2014-08-01

    Full Text Available The Illumina HiSeq2000 DNA sequencing generated 2 906 977 265 high quality paired-end nucleotide sequences (reads and 576 Gbp for Siberian larch (Larix sibirica Ledeb. that corresponds to 48X coverage of the larch genome (12.03 Gbp, and 3 427 566 813 reads and 679 Gbp for Siberian stone pine (Pinus sibirica Du Tour that corresponds to 29X coverage of its genome (23.6 Gbp. These data are not enough to assemble and annotate whole genomes, but the obtained nucleotide sequences have allowed us to discover and develop effective highly polymorphic molecular genetic markers, such as microsatellite loci that are required for population genetic studies and identification of the timber origin. Sequence data can be used also to discover single nucleotide polymorphisms (SNPs. Genomic studies of Russian boreal forests and major phytopathogens associated with them will also allow us to identify biomarkers that can be used for solving important scientific and economic problems related to the conservation of forest genetic resources and breeding more resilient and fast growing trees with improved timber and resistance to diseases and adverse environmental factors.

  3. Navy Tactical Applications Guide, Volume 8 Part 2: Arctic - East Siberian/Chukchi/Beaufort Seas. Weather Analysis and Forecast Applications

    Science.gov (United States)

    1992-12-01

    Including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson ...evident (see NTAG Vol. 6, Section IC: Fett et al., 1986). Such cloud formations are always associated with severe thunderstorms and, frequently, tomadic

  4. The Medical Research Progress on Siberian Cocklebur Fruit%苍耳子药用研究进展

    Institute of Scientific and Technical Information of China (English)

    杜毅; 麻瑞平; 孟凡红

    2015-01-01

    本文简单介绍了炮制对苍耳子毒性及活性成分的影响,毒性、预防,如加热温度为150℃,并保温60分钟时,苍耳子中绿原酸含量最高,而绿原酸为主的酚酸类成分被认为是苍耳子中的主要镇痛抗炎活性成分。炒后去刺不但镇痛作用增强,而且毒性降低,可能是苍耳子毒蛋白受热后凝固变性不易浸出使然。重点从苍耳子复方制剂、中西结合、外用等4方面综述了近年苍耳子治疗急慢性鼻炎、鼻窦炎等的进展情况。%This paper introduced the effect of processing on toxicity and active ingredient of siberian cocklebur fruit.When it is heated to 150℃, and maintains the constant temperature 60 minutes, the content of chlorogenicacid in siberian cocklebur fruit reaches its highest density, therefore chlorogenic acid, such kind of the acid phenol acids, is considered as the main active components of analgesic & anti -inflammatory in siberian cocklebur fruit.The siberian cocklebur fruit’ s analgesic result will be enhanced, and toxicity reduced after stir-frying.We assumed that poisonous protein in siberian cocklebur fruit was resist being leached.This paper reviewed the recent research progress on siberian cocklebur fruit in the treatment of acute or chronic rhinitis and sinusitis.This paper had four sections:siberian cocklebur fruit compound preparations, therapy of integrated medicine and external use, etc.

  5. Molecular and immunological characterization of the first allergenic lipocalin in hamster: the major allergen from Siberian hamster (Phodopus sungorus).

    Science.gov (United States)

    Torres, José Alberto; de Las Heras, Manuel; Maroto, Aroa Sanz; Vivanco, Fernando; Sastre, Joaquín; Pastor-Vargas, Carlos

    2014-08-22

    The most frequent pet allergy is to cat and dog, but in recent years, it has become increasingly popular to have other pets, and the risk of exposure to new allergens is more prevalent. The list of new pets includes hamsters, and one of the most popular hamsters is the Siberian hamster (Phodopus sungorus). The aim of this study was the characterization and cloning of the major allergen from this hamster. The study of its allergenicity and cross-reactivity could improve the specific diagnosis and treatment for hamster-allergic patients. Thirteen Siberian hamster-allergic patients were recruited at the outpatient clinic. Protein extracts were prepared from the hair, urine, and salivary glands of four hamster species (European, golden, Siberian, and Roborovski). IgE-binding proteins were detected by immunoblotting and identified by mass spectrometry. The recombinant protein was produced in Escherichia coli and then purified by metal chelate affinity chromatography. The allergenic properties of the recombinant protein were tested by ELISA and immunoblotting, and biological activity was tested according to capacity for basophil activation. Three IgE-binding proteins were identified in extracts obtained from Siberian hamster hair, urine, and salivary glands. All proteins corresponded to the same protein, which was identified as a lipocalin. This lipocalin had no cross-reactivity with common and golden hamsters. The recombinant allergen was cloned and purified, showing similar IgE reactivity in vitro to Siberian hamster protein extracts. Also, the recombinant allergen was capable of producing biological activation in vivo. The major Siberian hamster allergen was cloned, and allergenic properties were characterized, providing a new tool for specific diagnosis of allergy to Siberian hamster.

  6. East Asia Rolls On

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The economic recovery in East Asia remains unchanged on its upward trajectory despite the earthquake and devastating tsunami in Japan on March 11.Growth in East Asia slowed after a sharp rebound from the global financial crisis but is improving nonetheless.The World Bank’s East Asia and Pacific Economic Update issued on March 21 projects real GDP growth in East Asia will be smaller than that of 2010 in the following two years.Besides future East Asian economic trends,the report also discusses the impact of the Japanese catastrophe.Edited excerpts follow:

  7. Green synthesis of multifunctional silver and gold nanoparticles from the oriental herbal adaptogen: Siberian ginseng

    Directory of Open Access Journals (Sweden)

    Abbai R

    2016-07-01

    Full Text Available Ragavendran Abbai,1,* Ramya Mathiyalagan,1,* Josua Markus,1 Yeon-Ju Kim,2 Chao Wang,2 Priyanka Singh,2 Sungeun Ahn,2 Mohamed El-Agamy Farh,2 Deok Chun Yang1,2 1Ginseng Bank, Graduate School of Biotechnology, 2Department of Oriental Medicinal Biotechnology, College of Life Sciences, Kyung Hee University, Yongin, Republic of Korea *These authors contributed equally to this work Abstract: Pharmacologically active stem of the oriental herbal adaptogen, Siberian ginseng, was employed for the ecofriendly synthesis of Siberian ginseng silver nanoparticles (Sg-AgNPs and Siberian ginseng gold nanoparticles (Sg-AuNPs. First, for metabolic characterization of the sample, liquid chromatography-tandem mass spectrometry analysis (indicated the presence of eleutherosides A and E, total phenol content, and total reducing sugar were analyzed. Second, the water extract of the sample mediated the biological synthesis of both Sg-AgNPs and Sg-AuNPs that were crystalline face-centered cubical structures with a Z-average hydrodynamic diameter of 126 and 189 nm, respectively. Moreover, Fourier transform infrared analysis indicated that proteins and aromatic hydrocarbons play a key role in the formation and stabilization of Sg-AgNPs, whereas phenolic compounds accounted for the synthesis and stability of Sg-AuNPs. 3-(4,5-Dimethyl-2-thiazolyl-2,5-diphenyl-2H tetrazolium bromide (MTT assay determined that Sg-AgNPs conferred strong cytotoxicity against MCF7 (human breast cancer cell line and was only slightly toxic to HaCaT (human keratinocyte cell line at 10 µg·mL-1. However, Sg-AuNPs did not display cytotoxic effects against both of the cell lines. The disc diffusion assay indicated a dose-dependent increase in the zone of inhibition of Staphylococcus aureus (ATCC 6538, Bacillus anthracis (NCTC 10340, Vibrio parahaemolyticus (ATCC 33844, and Escherichia coli (BL21 treated with Sg-AgNPs, whereas Sg-AuNPs did not show inhibitory activity. In addition, the 2,2-diphenyl-1

  8. Possible causes of methane release from the East Arctic seas shelf

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    O. A. Anisimov

    2014-01-01

    Full Text Available We analyze data on methane concentration in the water and lower atmosphere over the shelf of the East Siberian Arctic Seas, which were obtained using marine, terrestrial, and satellite observations. Our study is targeted towards attribution of the enhanced concentrations of methane above the latitudinal-mean, which have been detected at selected locations of these seas. We compare two hypothesis, which attribute it to the effect of modern changes of the sub aquatic permafrost, and to geological factors (tectonics, presence of fault zones and paleo river beds in the study region. Our analysis showed that the methane concentration in sea water are directly related to the distance to the nearest fault zone or paleo river bed, where permafrost is absent and bottom sediments are perforated allowing methane to escape from the deep layers containing gas hydrates. This result indicate that the enhanced emission of methane, which was observed at selected locations of the shelf, is not related to the modern climate change. Earlier study, which was based on mathematical modeling, did not find intensive development of taliks as well as other processes that lead to increased gas permeability of the bottom sediments. Taken together, these results reject the hypothesis of methane catastrophe on the East Siberian Arctic Seas shelf over the foreseeable future.

  9. A potential vorticity-based index for the East Asian winter monsoon

    Science.gov (United States)

    Huang, Wenyu; Wang, Bin; Wright, Jonathon S.

    2016-08-01

    A novel dynamically based index that reflects the strength of the regional potential vorticity (PV) intrusion on the 300 K isentropic surface is proposed as a reliable measure of East Asian winter monsoon (EAWM) intensity. The index captures essential aspects of the EAWM, including its climatic influences on East Asia, its continuous weakening trend since the 1980s, and its close relationships with the Siberian high, Arctic Oscillation, and El Niño. The use of a potential vorticity framework enables the definition of a new metric called continuous PV intrusion duration (CPVID), which can be used to monitor and explain wintertime weather extremes like the extreme snowfall event that occurred in south China during January 2008. The CPVID of March is comparable to that of December, indicating that data from this month should be included in estimates of the strength of the EAWM.

  10. East Scandinavian and Noril'sk plume mafic large igneous provinces of Pd-Pt ores: Geological and metallogenic comparison

    Science.gov (United States)

    Mitrofanov, F. P.; Bayanova, T. B.; Korchagin, A. U.; Groshev, N. Yu.; Malitch, K. N.; Zhirov, D. V.; Mitrofanov, A. F.

    2013-09-01

    This paper compares the geological, geophysical, and isotopic geochemical data on the Paleoproterozoic East Scandinavian Pd-Pt province in the Baltic Shield and the Late Paleozoic Noril'sk Pd-Pt province in the Siberian Craton. Both provinces contain large magmatic PGE deposits: low-sulfide in the Baltic Shield and high-sulfide in the Siberian Craton. Multidisciplinary evidence shows that the East Scandinavian mafic large igneous province, which has a plume nature, is intracratonic and was not subjected to the crucial effect of subduction-related and other contamination processes, whereas the Noril'sk province is pericratonic with substantial crustal contamination of the intrusive processes. Low-sulfide Pd-Pt deposits dominate in the East Scandinavian province, while high-sulfide Ni-Cu-PGE deposits play the leading role in the Noril'sk province. The U-Pb, Sm-Nd, and Rb-Sr isotopic data indicate multistage and long-term (tens of millions of years) geological history of mafic large igneous provinces. The plume magmatism with specific geochemistry and metallogeny is probably related to lower mantle sources.

  11. Impact of climate change on radial growth of Siberian spruce and Scots pine in North-western Russia

    Directory of Open Access Journals (Sweden)

    Lopatin E

    2008-02-01

    Full Text Available When adapting forest management practices to a changing environment, it is very important to understand the response of an unmanaged natural forest to climate change. The method used to identify major climatic factors influencing radial growth of Siberian spruce and Scots pine along a latitudinal gradient in north-western Russia is dendroclimatic analysis. A clear increasing long-term trend was identified in air temperature and precipitation. During the last 20 years, all meteorological stations experienced temperature increases, and 40 years ago precipitation began to increase. This is shown by the radial increment of Siberian spruce and Scots pine. Therefore, climate change could partly explain the increased forest productivity. The total variance explained by temperature varied from 22% to 41% and precipitation from 19% to 38%. The significant climatic parameters for radial increment in Komi Republic were identified, and the relation between temperature and precipitation in explained variance changes over time for Siberian spruce.

  12. Control of origin of larch wood: discrimination between European (Austrian) and Siberian origin by stable isotope analysis.

    Science.gov (United States)

    Horacek, Micha; Jakusch, Michael; Krehan, Hannes

    2009-12-01

    Most of the coniferous wood of non-European origin that is imported into the European Union (EU) has to be inspected phytosanitarily, to prevent the introduction and spread of harmful pests in EU territory. Wood importers have been caught declaring Siberian larch wood as being of European origin to save the costs of the inspection. Therefore, an unequivocal method has to be developed in addition to the traditional analysis of the tree ring density to identify incorrect declarations of larch wood origin. For this purpose, delta18O and delta13C analyses have been carried out to check if Siberian larch wood can be discriminated from European larch. Measurements have been carried out on bulk wood samples, as the method has to be designed to be as simple as possible. The results show an overlapping of the Siberian and Austrian delta13C, and no overlapping for the delta18O values. Copyright 2009 John Wiley & Sons, Ltd.

  13. Impact of climate change on radial growth of Siberian spruce and Scots pine in North-western Russia

    Directory of Open Access Journals (Sweden)

    Lopatin E

    2007-01-01

    Full Text Available When adapting forest management practices to a changing environment, it is very important to understand the response of an unmanaged natural forest to climate change. The method used to identify major climatic factors influencing radial growth of Siberian spruce and Scots pine along a latitudinal gradient in north-western Russia is dendroclimatic analysis. A clear increasing long-term trend was identified in air temperature and precipitation. During the last 20 years, all meteorological stations experienced temperature increases, and 40 years ago precipitation began to increase. This is shown by the radial increment of Siberian spruce and Scots pine. Therefore, climate change could partly explain the increased forest productivity. The total variance explained by temperature varied from 22% to 41% and precipitation from 19% to 38%. The significant climatic parameters for radial increment in Komi Republic were identified, and the relation between temperature and precipitation in explained variance changes over time for Siberian spruce.

  14. Genome-wide analysis of cold adaptation in indigenous Siberian populations.

    Directory of Open Access Journals (Sweden)

    Alexia Cardona

    Full Text Available Following the dispersal out of Africa, where hominins evolved in warm environments for millions of years, our species has colonised different climate zones of the world, including high latitudes and cold environments. The extent to which human habitation in (sub-Arctic regions has been enabled by cultural buffering, short-term acclimatization and genetic adaptations is not clearly understood. Present day indigenous populations of Siberia show a number of phenotypic features, such as increased basal metabolic rate, low serum lipid levels and increased blood pressure that have been attributed to adaptation to the extreme cold climate. In this study we introduce a dataset of 200 individuals from ten indigenous Siberian populations that were genotyped for 730,525 SNPs across the genome to identify genes and non-coding regions that have undergone unusually rapid allele frequency and long-range haplotype homozygosity change in the recent past. At least three distinct population clusters could be identified among the Siberians, each of which showed a number of unique signals of selection. A region on chromosome 11 (chr11:66-69 Mb contained the largest amount of clustering of significant signals and also the strongest signals in all the different selection tests performed. We present a list of candidate cold adaption genes that showed significant signals of positive selection with our strongest signals associated with genes involved in energy regulation and metabolism (CPT1A, LRP5, THADA and vascular smooth muscle contraction (PRKG1. By employing a new method that paints phased chromosome chunks by their ancestry we distinguish local Siberian-specific long-range haplotype signals from those introduced by admixture.

  15. Differential expression of matrix metalloproteinases during stimulated ovarian recrudescence in Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    Salverson, Trevor J; McMichael, Greer E; Sury, Jonathan J; Shahed, Asha; Young, Kelly A

    2008-02-01

    The matrix metalloproteinases (MMPs) are a family of extracellular matrix-cleaving enzymes involved in ovarian remodeling. In many non-tropical species, including Siberian hamsters, ovarian remodeling is necessary for the functional changes associated with seasonal reproduction. We evaluated MMPs and their endogenous inhibitors (TIMPs), during photoperiod-induced ovarian recrudescence in Siberian hamsters. Hamsters were transferred from long day (LD; 16:8) to short day (SD; 8:16) photoperiods for 14weeks, and then returned to LD for 0, 1, 2, 4, or 8weeks for collection of ovaries and plasma. Post-transfer (PT) LD exposure increased body and ovarian mass. Number of corpora lutea and antral, but not preantral follicles increased in PT groups. Plasma estradiol concentrations were lower in PT weeks 0-4, and returned to LD levels at PT week 8. No change was observed in relative MMP/TIMP mRNA levels at PT week 0 (SD week 14) as compared to LD. Photostimulation increased MMP-2 mRNA at PT week 8 as compared to PT weeks 0-1. MMP-14 mRNA expression peaked at PT weeks 1-2 as compared to LD levels, while MMP-13 expression was low during this time. TIMP-1 mRNA peaked at PT week 8 as compared to PT weeks 0-4. No changes were noted in MMP-9 and TIMP-2 mRNA expression. In general, MMP/TIMP protein immunodetection followed the same patterns with most staining occurring in granulosa cells of follicles and corpora lutea. Our data suggest that mRNA and protein for several members of the MMP/TIMP families are expressed in Siberian hamster ovaries during recrudescence. Because of the variation observed in expression patterns, MMPs and TIMPs may be differentially involved with photostimulated return to ovarian function.

  16. An intact dorsomedial posterior arcuate nucleus is not necessary for photoperiodic responses in Siberian hamsters.

    Science.gov (United States)

    Teubner, Brett J W; Leitner, Claudia; Thomas, Michael A; Ryu, Vitaly; Bartness, Timothy J

    2015-04-01

    Seasonal responses of many animal species are triggered by changes in daylength and its transduction into a neuroendocrine signal by the pineal gland through the nocturnal duration of melatonin (MEL) release. The precise central sites necessary to receive, transduce, and relay the short day (SD) fall-winter MEL signals into seasonal responses and changes in physiology and behavior are unclear. In Siberian hamsters, SDs trigger decreases in body and lipid mass, testicular regression and pelage color changes. Several candidate genes and their central sites of expression have been proposed as components of the MEL transduction system with considerable recent focus on the arcuate nucleus (ARC) and its component, the dorsomedial posterior arcuate nucleus (dmpARC). This site has been postulated as a critical relay of SD information through the modulation of a variety of neurochemicals/receptors important for the control of energy balance. Here the necessity of an intact dmpARC for SD responses was tested by making electrolytic lesions of the Siberian hamster dmpARC and then exposing them to either long days (LD) or SDs for 12wks. The SD typical decreases in body and fat mass, food intake, testicular volume, serum testosterone concentrations, pelage color change and increased UCP-1 protein expression (a proxy for brown adipose tissue thermogenesis) all occurred despite the lack of an intact dmpARC. Although the Siberian hamster dmpARC contains photoperiod-modulated constituents, these data demonstrate that an intact dmpARC is not necessary for SD responses and not integral to the seasonal energy- and reproductive-related responses measured here.

  17. Impact of Siberian observations on the optimization of surface CO2 flux

    Science.gov (United States)

    Kim, Jinwoong; Kim, Hyun Mee; Cho, Chun-Ho; Boo, Kyung-On; Jacobson, Andrew R.; Sasakawa, Motoki; Machida, Toshinobu; Arshinov, Mikhail; Fedoseev, Nikolay

    2017-02-01

    To investigate the effect of additional CO2 observations in the Siberia region on the Asian and global surface CO2 flux analyses, two experiments using different observation data sets were performed for 2000-2009. One experiment was conducted using a data set that includes additional observations of Siberian tower measurements (Japan-Russia Siberian Tall Tower Inland Observation Network: JR-STATION), and the other experiment was conducted using a data set without the above additional observations. The results show that the global balance of the sources and sinks of surface CO2 fluxes was maintained for both experiments with and without the additional observations. While the magnitude of the optimized surface CO2 flux uptake and flux uncertainty in Siberia decreased from -1.17 ± 0.93 to -0.77 ± 0.70 Pg C yr-1, the magnitude of the optimized surface CO2 flux uptake in the other regions (e.g., Europe) of the Northern Hemisphere (NH) land increased for the experiment with the additional observations, which affect the longitudinal distribution of the total NH sinks. This change was mostly caused by changes in the magnitudes of surface CO2 flux in June and July. The observation impact measured by uncertainty reduction and self-sensitivity tests shows that additional observations provide useful information on the estimated surface CO2 flux. The average uncertainty reduction of the conifer forest of Eurasian boreal (EB) is 29.1 % and the average self-sensitivities at the JR-STATION sites are approximately 60 % larger than those at the towers in North America. It is expected that the Siberian observations play an important role in estimating surface CO2 flux in the NH land (e.g., Siberia and Europe) in the future.

  18. Connection between the Silk Road Pattern in July and the following January temperature over East Asia

    Science.gov (United States)

    He, Shengping; Liu, Yang; Wang, Huijun

    2017-04-01

    This study investigates a cross-seasonal influence of the Silk Road Pattern (SRP) in July and discusses the related mechanism. Both the reanalysis and observational datasets indicate that the July SRP is closely related to the following January temperature over East Asia during 1958/59-2001/02. Linear regression results reveal that, following a higher-than-normal SRP index in July, the Siberian high, Aleutian low, Urals high, East Asian trough, and meridional shear of the East Asian jet intensify significantly in January. Such atmospheric circulation anomalies are favorable for northerly wind anomalies over East Asia, leading to more southward advection of cold air and causing a decrease in temperature. Further analysis indicates that the North Pacific sea surface temperature anomalies (SSTAs) might play a critical role in storing the anomalous signal of the July SRP. The significant SSTAs related to the July SRP weaken in October and November, re-emerge in December, and strengthen in the following January. Such an SSTA pattern in January can induce a surface anomalous cyclone over North Pacific and lead to dominant convergence anomalies over northwestern Pacific. Correspondingly, significant divergence anomalies appear, collocated in the upper-level troposphere in situ. Due to the advection of vorticity by divergent wind, which can be regarded as a wave source, a stationary Rossby wave originates from North Pacific and propagates eastward to East Asia, leading to temperature anomalies through its influence on the large-scale atmospheric circulation.

  19. Spin flipping in rings with Siberian Snakes II: Simulations with localized orbit excursions

    Energy Technology Data Exchange (ETDEWEB)

    Mane, S.R., E-mail: srmane001@gmail.com [Convergent Computing Inc., P.O. Box 561, Shoreham, NY 11786 (United States)

    2012-07-21

    A new program EILMS is used to perform spin tracking simulations, for spin flippers in model rings with full strength Siberian Snakes, at a spin tune of 1/2 . EILMS employs canonical variables and symplectic-unitary integrators for all beamline elements. In particular, tracking studies are presented for a new design of a spin flipper proposed for stored polarized proton beams in RHIC. The induced coherent vertical betatron oscillations are localized within the flipper system. Points of detail which require further study are elucidated.

  20. About Characteristics of Diamonds of Perspective Areas of the Siberian Platform

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    N N Zinchuk

    2015-06-01

    Full Text Available As a result of carried out research and summarized materials on specific features of diamonds of the Siberian platform, conclusions were made that indications exist at all the levels of their occurrence: from diamondiferous provinces, sub-provinces, fields, diatremes, to ore columns. All the diamond varieties in kimberlite rocks forms not paragenetic, but parasteric associations based on the similarity of their coexistence in the kimberlites. Morphological criteria of kimberlite diamondiferousness according the quantitative content of rounded diamonds were formulated. Sufficient differences in diamondiferousness of kimberlites through all the explored depth of diatremes (up to 1200 m were not revealed.

  1. Comment on “Full spin flipping in the presence of full Siberian Snake”

    Directory of Open Access Journals (Sweden)

    S. R. Mane

    2009-09-01

    Full Text Available Bai and Roser {Phys. Rev. ST Accel. Beams 11, 091001 (2008PRABFM1098-440210.1103/PhysRevSTAB.11.091001 [Phys. Rev. ST Accel. Beams 12, 019901(E (2009]PRABFM1098-440210.1103/PhysRevSTAB.12.019901} have published an idea for a design of a spin flipper, consisting of two radial field rf dipoles with correlated phases, to operate with full strength Siberian Snakes, at a spin tune of 1/2. Some details of their design analysis are oversimplified.

  2. Exploration of horizontal intrinsic spin resonances with two partial Siberian snakes

    Science.gov (United States)

    Lin, F.; Ahrens, L. A.; Bai, M.; Brown, K.; Courant, E. D.; Gardner, C.; Glenn, J. W.; Huang, H.; Lee, S. Y.; Luccio, A. U.; Mackay, W. W.; Ptitsyn, V.; Roser, T.; Takano, J.; Tepikian, S.; Tsoupas, N.; Zelenski, A.; Zeno, K.

    2007-04-01

    Two partial Siberian snakes were used to avoid all the spin imperfection and vertical intrinsic resonances in the alternating gradient synchrotron (AGS) at Brookhaven National Laboratory. However, the horizontal betatron motion can cause polarization loss resulting from the nonvertical stable spin direction in the presence of two partial snakes. This type of resonance, called a horizontal intrinsic spin resonance, was observed and systematically studied in the AGS. A simplified analytic model and numerical simulation have been developed to compare with experimental data. Properties of the horizontal intrinsic resonance are discussed.

  3. Glycerides and phospholipids of the cambial zone of the Siberian larch

    Energy Technology Data Exchange (ETDEWEB)

    Levin, E.D.; Rubchevskaya, L.P.; Vol, Ye.V.

    1983-01-01

    The composition is studied of glycerides and phospholipids of cambial zone of the Siberian larch and its annual dynamics. It is shown that monoglycerides, diglycerides and triglycerides are in the composition of the glycerides. The fatty acids of the glycerides are represented by a C12 to C24 series. The basic component of these compounds are unsaturated C18 acids. In the cambial zone there are phospholipids whose basic components are phosphatidylcholine and phosphatidylethanolamines. Their share of the weight in March exceeds 80 percent and in August is 69 percent of the weight of the phospholipids.

  4. ETHNOCULTURAL CONTEXT IN “SIBERIAN TALES” OF V.G. KOROLENKO

    Directory of Open Access Journals (Sweden)

    Oxana Ivanova

    2012-05-01

    Full Text Available The special features of ethnocultural context in the “Siberian Tales” of V.G. Korolenko based on the stories “Makar’s Dream”, “Sokolinets”,“Marusya’s wood house” are analyzed in this paper. The representatives of such nationalities as Yakuts, Russians and Tatars are regarded. The specific peculiarities of the representatives of these nationalities are pointed out. The dependence of the main national character features from the environment, severe climate and Yakut conditions is underlined.

  5. Exploration of horizontal intrinsic spin resonances with two partial Siberian snakes

    Directory of Open Access Journals (Sweden)

    F. Lin

    2007-04-01

    Full Text Available Two partial Siberian snakes were used to avoid all the spin imperfection and vertical intrinsic resonances in the alternating gradient synchrotron (AGS at Brookhaven National Laboratory. However, the horizontal betatron motion can cause polarization loss resulting from the nonvertical stable spin direction in the presence of two partial snakes. This type of resonance, called a horizontal intrinsic spin resonance, was observed and systematically studied in the AGS. A simplified analytic model and numerical simulation have been developed to compare with experimental data. Properties of the horizontal intrinsic resonance are discussed.

  6. Orbital parameters of proton and deuteron beams in the NICA collider with solenoid Siberian snakes

    Science.gov (United States)

    Kovalenko, A. D.; Butenko, A. V.; Kekelidze, V. D.; Mikhaylov, V. A.; Kondratenko, M. A.; Kondratenko, A. M.; Filatov, Yu N.

    2016-02-01

    Two solenoid Siberian snakes are required to obtain ion polarization in the “spin transparency” mode of the NICA collider. The field integrals of the solenoid snakes for protons and deuterons at maximum momentum of 13.5 GeV/c are equal to 2×50 T·m and 2×160 T·m respectively. The snakes introduce strong betatron oscillation coupling. The calculations of orbital parameters of proton and deuteron beams in NICA collider with solenoid snakes are presented.

  7. Architectural Trend of the Epoch: Architect Chernyshev as a bright representative of the Siberian Modern

    Directory of Open Access Journals (Sweden)

    Olga Uspenskaya

    2016-10-01

    Full Text Available The article is about a bright representative of the Siberian Modern, Leonid Alexandrovich Chernyshev, who made a great contribution to the development of Krasnoyarsk city architecture. On the initiative of the Board of the Krasnoyarsk regional organization of the Union of Architects of Russia the year 2015 in Krasnoyarsk was announced the Year of the Architect Chernyshev to commemorate his 140th anniversary. During the anniversary year several important events will be held to demonstrate the architect’s creative heritage both to architects and citizens.

  8. ANALYSIS OF ACTIVITIES PROVIDING IMPACT ON TUBERCULOSIS MORTALITY RATE ESTIMATION IN THE REGIONS WITHIN SIBERIAN FEDERAL DISTRICT

    Directory of Open Access Journals (Sweden)

    O. V. Revyakina

    2016-01-01

    Full Text Available Basing on the data about achievement of targeted rates for efficiency evaluation of the actions aimed at tuberculosis mortality reduction in 2015 and statistic rates for 2014-2015 in 12 regions within Siberian Federal District, the impact of organizational medical activities performed by primary medical services and tuberculosis control services was analyzed in the respect of tuberculosis mortality rate. The article presents results of ranging of regions within Siberian Federal District as per tuberculosis mortality rate and indicators providing impact on the number of those died of tuberculosis.

  9. NUMBER AND STRUCTURE OF MEDICAL STAFF IN THE SIBERIAN CITIES IN THE GREAT PATRIOTIC WAR OF 1941-1945

    Directory of Open Access Journals (Sweden)

    Yuliya A. Davidova

    2013-01-01

    Full Text Available A dynamics of the number of medical personnel Siberian cities in the Great Patriotic war is analyzed in the article. The author studies quantity and structure of senior and low-grade medical personnel of healthcare institutions, shows its impact on medical and sanitarian anti-epidemic work, as well as considers methods of decision of personnel problem in the region. The study is based on analysis of documents of the State Archive of the Russian Federation, the Russian State Archive of Socio-Political History, the Russian State Archive of Economy and the Regional Archives of the Siberian cities.

  10. Surface wave group velocity tomography of East Asia, part 1

    Science.gov (United States)

    Wu, Francis T.

    1993-07-01

    Group velocities of both Rayleigh and Love waves are used in a tomographic inversion to obtain group velocity maps of East Asia (60 deg E-140 deg E and 20 deg N-50 deg N). The period range studied is 30-70 seconds. For periods longer than 40 seconds, a high group velocity gradient clearly exists along longitude 105 deg E; the velocities are noticeably higher east of this longitude than west of this longitude. The Tibetan Plateau appears as a prominent low velocity (about 15%) structure in this area; central Tibet appears as the area with the lowest velocity. The North China Plain is an area of high velocities, probably as a result of thin crust. The variability of deep crustal and upper mantle structures underneath the different tectonic provinces in the study can clearly be seen. In a separate study, using the dataset above and that from the former Soviet Union, we have derived the Rayleigh tomographic images of a larger area (40 deg E-160 deg E and 20 deg N-70 deg N). While the Tibetan plateau still remains to be the most prominent low velocity features, two other features are also clear, a very high velocity Siberian platform and a high velocity ridge extending from Lake Baikal to Central Mongolia. These studies are useful in delineating tectonics.

  11. The Middle East.

    Science.gov (United States)

    Blouin, Virginia; And Others

    This sixth grade resource unit focuses on Middle East culture as seen through five areas of the social sciences: anthropology-sociology, geography, history, economics, and political science. Among objectives that the student is expected to achieve are the following: 1) given general information on the Middle East through the use of film, visuals,…

  12. Middle East Respiratory Syndrome

    Centers for Disease Control (CDC) Podcasts

    2014-07-07

    This podcast discusses Middle East Respiratory Syndrome, or MERS, a viral respiratory illness caused by Middle East Respiratory Syndrome Coronavirus—MERS-CoV.  Created: 7/7/2014 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 7/7/2014.

  13. Recovery in the East

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    As robust as the economic recovery in East Asia has been in recent months,attention must now be turned to managing emerging risks challenging macroeconomic stability,said World Bank’s latest East Asia and Pacific Economic Update released on October 19.Edited excerpts follow

  14. Evaluation of four suture materials for surgical incision closure in Siberian sturgeon

    Science.gov (United States)

    Boone, S. Shaun; Hernandez, Sonia M.; Camus, Alvin C.; Peterson, Douglas C.; Jennings, Cecil A.; Shelton, James L.; Divers, Stephen J.

    2015-01-01

    The visual and microscopic tissue reactions to the absorbable monofilament Monocryl, absorbable monofilament triclosan-coated Monocryl-Plus, absorbable multifilament Vicryl, and nonabsorbable monofilament Prolene were evaluated for their use of surgical closure in Siberian Sturgeon Acipenser baerii. Postoperative assessments were conducted at 1, 2, 8, 12, and 26 and 55 weeks to visually evaluate the surgical incision for suture retention, incision healing, erythema, and swelling. Incisions were also assessed microscopically at 1, 2, and 8 weeks for necrosis, inflammation, hemorrhage, and fibroplasia. The results indicated that incisions closed with either Vicryl or Prolene suture materials were more likely to exhibit more erythema or incomplete healing compared with those closed with Monocryl or Monocryl-Plus. The surgical implantation of a transmitter in the coelomic cavity did not significantly affect the response variables among the four suture materials. Monocryl or Monocryl-Plus were equally effective and superior to other suture materials used for closing surgical incisions in Siberian Sturgeon or closely related species of sturgeon. Furthermore, Monocryl or Monocryl-Plus may decrease the risk of transmitter expulsion through the incision, as surgical wounds appear to heal faster and exhibit less erythema compared with those closed with Vicryl.

  15. Geochemical evaluation of oils and source rocks from the Western Siberian basin, U. S. S. R

    Energy Technology Data Exchange (ETDEWEB)

    Peters, K.E.; Huizinga, B.J. (Chevron Overseas Petroleum, Inc., San Ramon, CA (United States)); Moldowan, J.M. (Chevron Oil Field Research Co., Richmond, CA (United States)); Kontorovich, A.E.; Stasova, O. (Siberian Scientific Research Institute for Geology, Geophysics and Mineral Resources, Novobsibirsk (Russian Federation)); Demaison, G.J.

    1991-03-01

    Although the Western Siberian basin is among the most prolific in the world, there has been disagreement among Soviet geoscientists on the origin of the petroleum within this basin. Screening geochemical analyses were used to select several oils and potential source rocks for a preliminary study using detailed biomarker and supporting geochemistry. Possible sources for this petroleum include rocks of Middle Jurassic, Upper Jurassic, and Lower Cretaceous age. Results indicate that most of the analyzed Western Siberian oils, occurring in reservoirs from Middle Jurassic to Late Cretaceous in age, are derived from the Upper Jurassic Bazhenov Formation. The locations of the samples in the study generally correspond to the distribution of the most effective oil-generative parts of the Bazhenov Formation. Analyses show that the Bazhenov rock samples contain abundant marine algal and bacterial organic matter, preserved under anoxic depositional conditions. Biomarkers show that thermal maturities of the samples range from the early to late oil-generative window and that some are biodegraded. For example, the Salym No. 114 oil, which flowed directly from the Bazhenov Formation, shows a maturity equivalent to the late oil window. The Van-Egan no. 110 oil shows maturity equivalent to the early oil window and is biodegraded. This oil shows preferential microbial conversion of lower homologs of the 17{alpha}, 21{beta}(H)-hopanes to 25-nor-17{alpha}(H)-hopanes.

  16. The Siberian Traps and the End-Permian mass extinction: a critical review

    Institute of Scientific and Technical Information of China (English)

    Andy SAUNDERS; Marc REICHOW

    2009-01-01

    The association between the Siberian Traps,the largest continental flood basalt province,and thelargest-known mass extinction event at the end of the Permian period,has been strengthened by re-cently-published high-precision 40Ar/39Ar dates from widespread localities across the Siberian prov-ince[i].We argue that the impact of the volcanism was amplified by the prevailing late Permian envi-ronmental conditions-in particular,the hothouse climate,with sluggish oceanic circulation,that wasleading to widespread oceanic anoxia.Volcanism released large masses of sulphate aerosols andcarbon dioxide,the former triggering short-duration volcanic winters,the latter leading to long-termwarming.Whilst the mass of CO2 released from individual eruptions was small compared with the totalmass of carbon in the atmosphere-ocean system,the long 'mean lifetime' of atmospheric C02,com-pared with the eruption flux and duration,meant that significant accumulation could occur over periodsof 10s years.Compromise of the carbon sequestration systems (by curtailment of photosynthesis,de-struction of biomass,and warming and acidification of the oceans) probably led to rapid atmosphericCO2 build-up,warming,and shallow-water anoxia,leading ultimately to mass extinction.

  17. Estimating the variations in paleointensity from the Siberian traps of Maymecha-Kotui and Norilsk regions

    Science.gov (United States)

    Scherbakova, V. V.; Zhidkov, G. V.; Latyshev, A. V.; Scherbakov, V. P.

    2013-07-01

    The results of determining the paleointensity of the Siberian traps sampled from the Kotui sequence, Truba ravine, Onkuchak Suite, and dated to Permian-Triassic are presented. Most of the H anc values for separate lava flows are significantly lower than the values of the present geomagnetic field at the observation point (approximately 50 μT). This is consistent with the known conclusion that the intensity of the geomagnetic field at the Permian-Triassic boundary was lower by a factor of two to three lower than its present value. We carried out the comparative analysis of the behavior of H an and VDM for two trap sequences (Kotui (the Onkuchak Suite) and Norilsk) from the standpoint of the eruptive pulse hypothesis. In both sections, the average VDM values and their dispersion are similar. For comparison, similar analysis of the VDM behavior is conducted for the Brunhes epoch and Miocene in the interval of 5-10 Ma. It is hypothesized that during the three considered periods, namely, the eruption of the Siberian traps, in the Brunhes epoch, and in Miocene (in the interval of 5-10 Ma), the time behavior of the geomagnetic field was close to a stationary stochastic process.

  18. Hematologic, serologic, and histologic profile of aged Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    McKeon, Gabriel P; Nagamine, Claude M; Ruby, Norman F; Luong, Richard H

    2011-05-01

    Biologic samples from 18 (12 female, 6 male) Siberian hamsters (Phodopus sungorus) representing an aged colony (17 to 27 mo) were examined. Values for CBC and serum biochemical parameters were determined, and macroscopic and microscopic pathologic evaluations were performed. Blood urea nitrogen levels were significantly higher in male (54.2 ± 14 mg/dL) compared with female (35.3 ± 22 mg/dL) hamsters and correlated histologically with a higher incidence of chronic glomerulonephropathy in males (5 of 6 males; 0 of 12 females). All 18 hamsters had histologic evidence of follicular mite infestation. Half (6 of 12) of the female hamsters showed cystic rete ovarii. Other histologic findings included thymic or thyroid branchial cysts (3 of 18), focal enteritis (2 of 18), and single cases of hepatic hemangiosarcoma, renal adenoma, subcutaneous mast cell tumor, cutaneous sebaceous adenoma, cutaneous trichofolliculoma, squamous papilloma of the nonglandular stomach, epididymal cholesteatoma, pyometra, and pituitary craniopharyngeal cyst. This study is the first published report of hematologic and serum chemical values for any population of Siberian hamsters and the first published report showing a potential male predisposition for chronic progressive glomerulonephropathy and a potential female predisposition for cystic rete ovarii.

  19. New data on biostratigraphy of the Vendian Nemakit-Daldynian stage in the southern Siberian platform

    Science.gov (United States)

    Kochnev, B. B.; Karlova, G. A.

    2010-10-01

    New paleontological finds in sediments of the Upper Vendian Nemakit-Dadynian Stage from different areas of the southern Siberian Platforms (Yenisei Range, Sayany region, central areas, Patom Highland) are discussed. The base of the Lower Cambrian Tommotian Stage (˜540 Ma) is established at the first appearance level of characteristic small-shelled fossils in the western part of the Patom Highland. This boundary coincides with the episode of a brief sea-level fall and enhanced terrigenous sedimentation in the basin with dominant carbonate sediment deposition. The base of the Purella antiqua Zone (544 Ma), which is registered by paleontological data in the Yenisei Range sections, is marked by the replacement of terrigenous sedimentation by the carbonate one. In the northwestern Yenisei Range, this boundary coincides, in addition, with a major hiatus and subsequent paleobasin extension. The base of the Nemakit-Daldynian Stage (base of the Anabarites trisulcatus Zone, ˜550 Ma) in most sections corresponds to the onset of sea transgression. In addition to small-shelled remains, sediments of this zone contain characteristic ichnofossils and Vendotaenia flora. It is shown that defined boundaries are traceable through the entire southern part of the Siberian Platform. This makes them useful for wider stratigraphic interpretations.

  20. Histiocytic Sarcoma and Bilateral Facial Vein Thrombosis in a Siberian Hamster (Phodopus sungorus).

    Science.gov (United States)

    Coble, Dondrae J; Shoemaker, Margaret; Harrington, Bonnie; Dardenne, Adrienne D; Bolon, Brad

    2015-04-01

    A 21-mo-old, male Siberian hamster (Phodopus sungorus) presented with left-sided facial swelling, proptosis of the left eye, and blepharospasm of the right eye. The hamster had been used only for breeding. Because of the poor prognosis, the hamster was euthanized without additional diagnostic assays or treatments. Routine gross pathologic evaluation demonstrated exophthalmos and presumptive hyphema of the left eye, bilateral facial edema, freely movable nodules within the mesentery, white foci within the liver, and a large mass effacing the cranial pole of the right kidney. On histologic evaluation, the mesenteric nodules and liver foci expressed histiocytic marker CD163 and thus were diagnosed as sites of histiocytic sarcoma, whereas the kidney mass was a well-differentiated renal cell carcinoma. The facial swelling resulted from bilateral, chronic, severe, branching thrombi in many facial veins. Additional age-related histopathologic findings were observed in other organs, including diffuse glomerulopathy, nesidioblastosis (pancreatic islet neoformation), and multiple foci of severe cartilage degeneration in the axial skeleton. To our knowledge, this report provides the first description of histiocytic sarcoma in a Siberian hamster.

  1. The upper mountain forest and tree response to climate change in south Siberian Mountains

    Science.gov (United States)

    Kharuk, V.; Ranson, J.

    2010-12-01

    The aim of this study is to evaluate topographic features of high elevation mountain environments govern spatial distribution and climate-driven dynamics of the forests growing there. The study area included upper mountain forest stands formed by larch (Larix sibirica Ledeb) and Siberian pine(Pinus sibirica Du Tour) (elevation range 1800-2600 m) in the mountains of southern Siberia. We used archive maps, satellite and on-ground data from 1960-2002. Data were normalized to avoid bias caused by uneven distribution of elevation, and slope steepness within the analyzed area. Spatial distribution of forest stands were analyzed with respect to topography based on a DEM. The primary results show that mountain forest spatial patterns are anisotropic with respect to topography. At a given elevation, the majority of forests occupied slopes with greater than mean slope values. As the elevation increased forests shifted to steeper slopes. The forest azimuth distribution orientation changed clockwise with elevation increase (total shift was 120 deg) indicating a combined effect of wind and water stress on the observed forest patterns. Warming caused changes in the forest distribution patterns during the last four decades. The area of closed forests increased 1.5 times, which was attributed to increased stand density and tree migration. The migration rate was 1.5 ± 0.9 m yr^-1 and caused a mean forest line shift of 63 ± 37m. Along with upward migration, downward tree migration onto hill slopes was observed. Changes in tree morphology were also noted as wide-spread transformation of the prostrate forms of Siberian pine and larch into erect forms. An analysis of the radial growth increments showed that the widespread vertical transformation of krummholz began in the mid -1980s. Radial and apical growth increments correlated with increase in air temperature (summer and “cold period”) and CO2 concentration. Regeneration responded to temperature increase of 1 deg C by migration

  2. Siberian Origins of Neoproterozoic to Upper Triassic Rocks of Arctic Alaska

    Science.gov (United States)

    Clough, J. G.; Blodgett, R. B.

    2007-12-01

    Evidence for a connection of the Arctic Alaska plate (including Chukotka) with Siberia from Cambrian until Late Triassic time can be made on the basis of paleobiogeography. Arctic Alaska contains a number of biogeographically distinctive megafossils for select time intervals, notably the Middle Cambrian, Early and Late Ordovician, Early and Middle Devonian, Mississippian, and Late Triassic. Middle Cambrian trilobites are strictly Siberian in affinity, but also show close affinities with coeval trilobites from the Farewell terrane of SW Alaska. Late Ordovician brachiopods, gastropods, trilobites, and ostracodes are known from the Shublik Mountains, NE Brooks Range and York Mountains of the Seward Peninsula. Affinities are likewise primarily with Siberia (sharing the primarily Siberian pentameroid brachiopod genera Tcherskidium and Eoconchidium and the strictly Siberian trilobite genus Monorakos), but also with the Farewell terrane. Late Early Devonian and Middle Devonian brachiopods and calcareous green algae from Arctic Alaska are similarly allied with Siberia and the Farewell and Alexander terranes of southern Alaska. Early Mississippian faunas from the lower part of the Lisburne Group and underlying Endicott Group contain relatively widespread fauna, including taxa recognized both in North America and Eurasia, consistent with the relatively cosmopolitan paleobiogeographic conditions of this interval. However, Late Mississippian brachiopod fauna from the upper part of the Lisburne Group contain many brachiopods of strictly Eurasian affinities, notably the gigantoproductids, which are unknown in cratonic North America, but widespread across Eurasia and even North Africa. Late Mississippian lycopods from this terrane have previously been noted as demonstrating strong Angaran affinities. Permian faunas of Arctic Alaska show strong affinities as well with the Siberian Arctic, virtually lacking any fusilinids and reefal buildups, which in contradistinction are commonly

  3. Central Siberian taiga mapping using by SPOT 4 and inventory data

    Science.gov (United States)

    Romanov, Aleksey

    2013-04-01

    One of the main purposes of this research was evaluation of the suitability of satellite data middle resolution for Central Siberian forest mapping. The study area is located on the right bank of the Yenisei River between Podkamennaya Tunguska and Nizhnyaya Tunguska rivers (the Central Siberian Plateau) on the Central Siberian Natural Biosphere reserve. Nowadays there are several maps for this region which could be divided for two types conditionally: cartographic material obtained through field work of the 1930-1980 (for some part the last inventory was conducted in 1990) and satellite maps based on the coarse resolution images (such as AVHRR, SPOT VEGETATION and MODIS). General idea was to develop methodology main trees species precision mapping by SPOT 4 data sets. Training samples for the images classification was based on the results of the field inventory researches conducted in 2009-2011. A technology sample plot lying was oriented on the spatial resolution of SPOT4 multispectral bands. Each point geometrically represented a square of 20 x 20 meters and describes the following each of trees species parameters: max and min diameters, numbers of stems, max/min height, density, plot's altitude. During the field works was prepared 43 sample plots spread over a total area of 70 sq km (total Reserve area is about 1 million sq ha); each point's location determined by the landscape oriented approach, geo-referencing was carried out with the GPS. Also during the project the digital elevation model of the Reserve has been adjusted using the updated field data. Time series of satellite images was selected not only for summer periods of 2009-2011 but also a few clouds free winter images. Mapping technology involves several stages thematic processing: initially classification carried out strictly according to the results of fields' works data sets inside the local area of 70 sq km; processing was based on statistical supervised methods of classification. On the next step

  4. Valanginian ammonites in East Greenland

    DEFF Research Database (Denmark)

    Alsen, Peter

    2001-01-01

    ammonites, Boreal, Tethys, bed-by-bed collection, Valanginian, Wollaston Forland, East Greenland......ammonites, Boreal, Tethys, bed-by-bed collection, Valanginian, Wollaston Forland, East Greenland...

  5. On 4 June 2008 Siberian Red Knots at Elbe Mouth kissed the canonical evening migration departure rule goodbye

    NARCIS (Netherlands)

    Leyrer, Jutta; Pruiksma, Sytze; Piersma, Theunis; Heg, Dierik

    2009-01-01

    Observations of departing Siberian-breeding Red Knots Calidris canutus canutus from their central staging site during northward migration, the Schleswig-Holstein Wadden Sea, Germany, in early June 2008, challenge the established notion that departing long-distance migrating waders only leave around

  6. Photoperiod and acute energy deficits interact on components of the thyroid hormone system in hypothalamic tanycytes of the Siberian hamster

    NARCIS (Netherlands)

    A. Herwig; D. Wilson; T.J. Logie; A. Boelen; P.J. Morgan; J.G. Mercer; P. Barrett

    2009-01-01

    Herwig A, Wilson D, Logie TJ, Boelen A, Morgan PJ, Mercer JG, Barrett P. Photoperiod and acute energy deficits interact on components of the thyroid hormone system in hypothalamic tanycytes of the Siberian hamster. Am J Physiol Regul Integr Comp Physiol 296: R1307-R1315, 2009. First published March

  7. Morphological Characteristics and Water-Use Efficiency of Siberian Elm Trees (Ulmus pumila L. within Arid Regions of Northeast Asia

    Directory of Open Access Journals (Sweden)

    Go Eun Park

    2016-11-01

    Full Text Available The Siberian elm (Ulmus pumila L. is one of the most commonly found tree species in arid areas of northeast Asia. To understand the morphological and physiological characteristics of Siberian elms in arid regions, we analyzed leaves from seven study sites (five arid or semi-arid and two mesic in China, Mongolia and the Republic of Korea, which covered a wide range of average annual precipitation (232 mm·year−1 to 1304 mm·year−1 under various aridity indexes (AI and four different microenvironments: sand dune, steppe, riverside and forest. The traits of Siberian elms varied widely along different annual precipitation (P and AI gradients. Tree height (H, leaf size (LS and stomatal area per unit leaf area (AS/AL decreased with increasing AI, whereas leaf mass per unit leaf area (LMA and water-use efficiency (WUE increased significantly. In addition, trees at the five arid sites showed significant differences in LS, LMA and AS/AL but not in H and WUE. Thus, our study indicated that indigenous Siberian elm trees in arid areas have substantially altered their morphological and physiological characteristics to avoid heat stress and increase water conservation in comparison to mesic areas. However, their changes differed depending on the surrounding microenvironment even in arid areas. Trees in sand dunes had a smaller LS, higher LMA, thicker leaf cuticle layer and higher stomatal density and AS than those in steppes and near a riverside.

  8. Initial assessment of multi-scale measures of C02 and H20 flux in the Siberian taiga

    Science.gov (United States)

    D.Y. Hollinger; F.M. Kelliher; E.-D. Schulze; N.N. Vygodskaya; A. Varlagin; I. Milukova; J.N. Byers; A. Sogachov; J.E. Hunt; T.M. McSeveny; K.I. Kobak; G. Bauer; A. Arneth

    1995-01-01

    We measured CO2 and H2O fluxes between undisturbed Larix gmelinii forest and the atmosphere at a remote Eastern Siberian site in July 1993. Scaled-up leaf-level porometer measurements agreed with those derived from the eddy correlation technique for the canopy fluxes of CO2 and H...

  9. Xylazine-midazolam-ketamine versus medetomidine-midazolam-ketamine anesthesia in captive Siberian tigers (Panthera tigris altaica).

    Science.gov (United States)

    Curro, Thomas G; Okeson, Danelle; Zimmerman, Dawn; Armstrong, Douglas L; Simmons, Lee G

    2004-09-01

    Two alpha2-adrenoceptor agents, xylazine and medetomidine, in combination with midazolam and ketamine safely and effectively immobilized Siberian tigers (Panthera tigris altaica). The medetomidine protocol used smaller drug volumes, and induction and recovery times were shorter. Although cardiopulmonary abnormalities were noted, none were likely to be life threatening.

  10. Distribution, densities, and ecology of Siberian cranes in the Khroma River region of northern Yakutia in northeastern Russia

    Science.gov (United States)

    Bysykatova, Inga P.; Krapu, Gary L.; Germogenov, Nicolai I.; Buhl, Deborah A.; Aborn, David

    2014-01-01

    The Siberian crane (Grus leucogeranus) is the third rarest crane species in the world with a breeding range now centered on 3 core areas and a buffer zone in the arctic of northern Yakutia in northeastern Russia. During 16 July-2 August 2009, we undertook ground surveys within the Khroma River core breeding area, surrounding buffer zone, and lands lying to the west of the known rbeeding range to estimate densities and determine habitat use and social status of Siberian cranes. A total of 142 Siberian cranes were sighted (including 55 pairs) at 54 locations with 32 cranes (including 13 pairs) sighted outside the currently known breeding range in the lower drainages of the Syalakh and Syuryuktyakh Rivers. After adjusting for a probability of detection of 0.484 (95% CI = 0.281-0.833), Siberian crane densities in the Khroma core area and the buffer zone averaged 0.0921 cranes/km2 and 0.0363 cranes/km2, respectively. A majority of cranes (n = 93 [65%]) occurred in complexes of large basin wetlands, with use centered in those having extensive beds of pendant grass (Arctophila fulva). Of the 142 cranes seen, 110 (77%) were paired, 21 (15%) were singles, and 11 (8%) were in groups of 3-5. The Khroma core supports 1 of 2 large concentrations of breeding Siberian cranes remaining in the wild; therefore, we recommend that consideration be given to designating a nature reserve that would encompass the Khroma core, adjacent buffer zone, and lands to the west (including coastal tundra areas along the lower drainages of the Syalah and Syuryuktyah Rivers). Further research is needed to gain additional insight into Siberian crane distribution and numbers on lands beyond the currently delineated western boundary of the Siberian crane breeding range in the Ust-Yana District of northern Yakutia. Important gaps remain in information needed to effectively guide conservation efforts for the Eastern Population, and recent advances in remote tracking technology offer potential

  11. Fluxus East / Petra Stegmann

    Index Scriptorium Estoniae

    Stegmann, Petra

    2008-01-01

    Näitusest "Fluxus East" Kumu Kunstimuuseumis. Fluxuse liikumisest leedu kunstniku George Maciunase (1931-1978) eestvedamisel. Liikumise ilmingutest Eestis (happeningid, muusikaaktsioonid, visuaalne poeesia, mail art). Kuraator Petra Stegmann, kujundaja Andrea Pichl

  12. East- African Medical Journal

    African Journals Online (AJOL)

    East African Medical Journal Vol 83 No. 8 August 2006 ... urology, ENT and orthopaedic groups and these ... no significant difference in orthopaedic patients mortality' with standard; we .... applying TRISS analysis to pediatric blunt trauma.

  13. EAST AFRICAN MEDICAL JOURNAL

    African Journals Online (AJOL)

    2001-12-01

    Dec 1, 2001 ... DIETARY PATTERNS AND DENTAL CARIES IN NURSERY SCHOOL CHILDREN IN NAIROBI ..... bottle act as a bacterial substrate and especially when the ... children for their co-operation, Colgate Palmolive (East Africa) for.

  14. Maternal entrainment of the developing circadian system in the Siberian hamster (Phodopus sungorus).

    Science.gov (United States)

    Duffield, G E; Ebling, F J

    1998-08-01

    The aim of these studies was to investigate maternal entrainment of developing circadian locomotor activity rhythms in the Siberian hamster. In Experiment 1, mothers were transferred from a 16:8 LD cycle into constant dim red light (DD) from the day of parturition, and wheel-running activity of the mother and pups was individually monitored from the time of weaning. The phases of the individual pups' rhythms were found to be synchronized both to the phase of the mother and to the phase of lights off (ZT 12) of the photo cycle that the mother was exposed to until the day of parturition. To investigate whether this synchrony might reflect direct effects of light acting upon the fetal circadian system in late gestation, the experiment was repeated but with mothers placed into DD early in pregnancy (circadian system. The third experiment investigated whether this entrainment occurred during the postnatal period. Breeding pairs were maintained on alternative light-dark cycles, LD and DL, that were 12 h out of phase. Litters born to mothers on one light-dark cycle were exchanged on the day of birth with foster mothers from the reversed light-dark cycle, then raised in DD. Control litters exchanged between mothers from the same light-dark cycle had similar litter synchrony as shown by nonfostered litters of Experiment 1. However, pups cross-fostered with mothers on reversed LD cycles showed a very different distribution of pup phases. Pups were not synchronized to their natural mother but to their foster mother. Moreover, pups were more scattered over the 24-h period and were found to be significantly synchronized to the phase of the reversed LD cycle. These results demonstrate the occurrence of postnatal entrainment in the Siberian hamster. The increased scatter produced by the cross-fostering paradigm results from some litters being completely entrained to the phase of the foster mother, some with an intermediate distribution between the phase of the natural and foster

  15. Burned and buried by the Siberian traps: tree trunks in volcaniclastics and lavas

    Science.gov (United States)

    Polozov, Alexander G.; Planke, Sverre; Svensen, Henrik H.; Jerram, Dougal A.; Looy, Cindy

    2017-04-01

    Major Phanerozoic mass extinctions could be explained by intense volcanic activity related to the formation of Large Igneous Provinces (LIPs). The Siberian Traps LIP possibly caused the most severe mass extinction on the Earth, the end-Permian extinction. This event is documented by global data showing the extinction of floral and faunal species and by stable isotope excursions. Information about the direct impact of the Siberian Traps on the local flora and fauna is scarce. By our knowledge, no detailed description has been done on the faith of trees in Siberia. However, the story of Late Permian giant trees like Cordaites and wood ferns, could shed light on the impact of the onset of the LIP magmatism and the related mass extinction. For the first time we describe that Late Permian tree trunks were buried in volcaniclastic deposits and at the footwall contact of the oldest lava flows of the Siberian Traps, and despite that this phenomenon is known by local geologists it is not well described in the literature. Tree trunks in volcaniclastic deposits were compressed during consolidation of the volcaniclastic material originated from pyroclastic density currents from nearby volcanic centers. Tree petrification is presented by quartz with minor sulphides, zeolite, calcite and sulphates. Tree trunks at the footwall contact of the lava flows have a better preserved year rings structure and late permineralization presented by calcite with minor quartz and sulphides. Our results demonstrate that intensive magmatic activity related with LIP formation affects land vegetation at various grades. Lavas have had a local violent impact, but burned and buried tree trunks have a better preserved structure reflecting single dominated permineralization processes than the tree trunks buried by pyroclastics that have covered extensive areas and followed by trees compression and later multistage permineralization. In a global context, such type of volcanic activity has a variable

  16. High Water Contents in the Siberian Cratonic Mantle: An FTIR Study of Udachnaya Peridotite Xenoliths

    Science.gov (United States)

    Doucet, Luc S.; Peslier, Anne H.; Ionov, Dimitri A.; Brandon, Alan D.; Golovin, Alexander V.; Ashchepkov, Igor V.

    2013-01-01

    Water is believed to be a key factor controlling the long-term stability of cratonic lithosphere, but mechanisms responsible for the water content distribution in the mantle remain poorly constrained. Water contents were obtained by FTIR in olivine, pyroxene and garnet for 20 well-characterized peridotite xenoliths from the Udachnaya kimberlite (central Siberian craton) and equilibrated at 2-7 GPa. Water contents in minerals do not appear to be related to interaction with the host kimberlite. Diffusion modeling indicates that the core of olivines preserved their original water contents. The Udachnaya peridotites show a broad range of water contents in olivine (6.5 +/- 1.1 to 323 +- 65 ppm H2O (2 sigma)), and garnet (0 - 23 +/- 6 ppm H2O). The water contents of olivine and garnet are positively correlated with modal clinopyroxene, garnet and FeO in olivine. Water-rich garnets are also rich in middle rare earth elements. This is interpreted as the result of interaction between residual peridotites and water rich-melts, consistent with modal and cryptic metasomatism evidenced in the Siberian cratonic mantle. The most water-rich Udachnaya minerals contain 2 to 3 times more water than those from the Kaapvaal craton, the only craton with an intact mantle root for which water data is available. The highest water contents in olivine and orthopyroxene in this study (>= 300 ppm) are found at the bottom of the lithosphere (> 6.5 GPa). This is in contrast with the Kaapvaal craton where the olivines of peridotites equilibrated at > 6.4 GPa have 6 GPa is lower or similar (8.4× 10(exp 16) to 8.0× 10(exp 18) Pa./s) to that of the asthenosphere (<= 3.7x10(exp 18) Pa./s ). Such lithologies would not be able to resist delamination by the convecting asthenosphere. However, seismology studies as well as the high equilibration pressures of our samples indicate that the Udachnaya cratonic lithosphere is 220-250 km thick. Consequently, the water-rich peridotites are likely not

  17. High-precision temporal constraints on intrusive magmatism of the Siberian Traps

    Science.gov (United States)

    Burgess, Seth; Bowring, Sam; Pavlov, Volodia E.; Veselovsky, Roman V.

    2014-05-01

    The broad temporal coincidence between large igneous province magmatism and some of the most severe biotic/environmental crises in Earth history has led many to infer a causal connection between the two. Notable examples include the end-Permian mass extinction and eruption/emplacement of the Siberian Traps large igneous province (LIP) and the end-Triassic mass extinction and the Central Atlantic Magmatic Province. In models proposing a causal connection between LIP magmatism and the environmental changes that lead to mass extinction, gases and particulates injected into the atmosphere are thought to cause abrupt changes in climate and ocean chemistry sufficient to drive mass extinction of marine and terrestrial biota. Magmatism has been proposed to cause voluminous volatile release via contact metamorphism of the sedimentary rocks. In the case of the Siberian Traps LIP, the compositions of sedimentary rocks (carbonates, evaporates, organic-rich shales) that host sills and dikes are ideal for greenhouse gas generation. When coupled with the enormous volume of Siberian LIP intrusive rocks, there is the potential for volatile generation on a scale necessary to drive environmental changes and mass extinction. This model must be tested by comparing the timing of intrusive magmatism with that of the mass extinction. Coupled high-precision geochronology and astrochronology have constrained the timing of biotic crisis and associated environmental perturbations from the deca-millennial to sub-millennial timescale, suggesting that the biotic crisis was abrupt, occurring over < 100 ka. Published geochronology on sills and dikes from the LIP are sparse and lack the necessary precision to resolve the relative timing of the two events outside of age uncertainty. We present new high-precision U-Pb zircon geochronology on seventeen gabbroic sills from throughout the magmatic province. This includes samples from the mineralized and differentiated intrusions in the Noril'sk region

  18. Variability in Albedo Associated with Fire-Mediated Controls on Stand Density in Siberian Larch Forests

    Science.gov (United States)

    Loranty, M. M.; Fullmer, J.; Nguyen, C. L.; Alexander, H. D.; Natali, S.; Bunn, A. G.; Davydov, S. P.; Goetz, S. J.; Mack, M. C.

    2015-12-01

    Fire is an integral component of boreal forests, and exerts strong control over ecosystem structure and function. The frequency and spatial extent of fire controls the age-class distribution of forests on the landscape. In addition, recent evidence from North American boreal forests has show that fire severity influences post-fire succession via impacts on seedling recruitment that manifest in mature ecosystems dominated by either deciduous or coniferous tree species. The effects of fire on ecosystem structure have important climate feedback implications; changes in forest density or leaf habit can influence surface net radiation by altering the snow-masking effects of vegetation. Although Siberian larch forests occupy a more than 2.8 million km2 of the boreal biome, and are the most prevalent forests in Russia, the influence of fire severity on succession and associated surface energy dynamics are less well understood in comparison to North American boreal forests. There is evidence suggesting that increased fire severity may lead to higher density of post-fire regrowth, but the influence of stand density on surface energy dynamics remains poorly quantified. Here, we quantify the effects of stand density on albedo across the Kolyma River basin using satellite-derived albedo and fire history in conjunction with maps and field observations of ecosystem structure. During snow-free periods albedo varies little with stand density. During periods of snow cover we find consistent negative correlations between multiple metrics of canopy cover and albedo. Albedo decreased with fire recovery over the forty-year fire record for the study area. However, the range of albedo observed within individual fire scars was similar to the magnitude of albedo recovery during the study period. This result indicates the importance of variability in post-fire regrowth within individual fire scars, potentially associated with fire severity, for understanding fire effects on surface energy

  19. Ginseng, Siberian

    Science.gov (United States)

    ... An inherited disorder that causes swelling and fevers (Familial Mediterranean fever). Early research suggests that taking a combination of ... the duration, number, and severity of attaches of familial Mediterranean fever in children. Hangover. Early research suggests that taking ...

  20. Siberian Light

    Institute of Scientific and Technical Information of China (English)

    Dorine; Houston

    1998-01-01

    Dear Xiao Lan, Since wishing you the joy of your Spring Festival, opening the Year of the Tiger,I have been reminded of the importance of the tiger in Chinese tradition, and have beenthinking about the tragedy of the extinction of this noble cat. Perhaps you will beinterested in a new novel that addresses the problems of tiger poaching in Siberia.

  1. Siberian forest fires and soil moisture anomalies observed with C-band scatterometer

    Science.gov (United States)

    Bartsch, A.; Balzter, H.; George, C.

    2009-12-01

    Forest fires are frequent in the Siberian taiga and are predicted to increase in frequency as a result of increased fire risk under drought conditions caused by climate change. There is, however, some uncertainty as to the extent to which drought influences forest fire frequency. Both, forest fires and drought conditions can be observed with satellite data. Here, we present an analyses of satellite-derived soil moisture anomaly data (ERS-1/2 scatterometer) and burned area maps (AVHRR/ATSR) over central Siberia for the years 1992-2000. Monthly mean soil moisture deviations were compared to the number of fire scars and the burned area. Results show that above average surface soil moisture conditions limit the possible burned area. The magnitude of a negative deviation does not determine the maximum size of by fire affected areas. More than 50% of area is burned under below average surface soil moisture condition in July and 80% in August.

  2. Feeding schedule controls circadian timing of daily torpor in SCN-ablated Siberian hamsters.

    Science.gov (United States)

    Paul, Matthew J; Kauffman, Alexander S; Zucker, Irving

    2004-06-01

    Timing of daily torpor was assessed in suprachiasmatic nucleus-ablated (SCNx) and sham-ablated Siberian hamsters fed restricted amounts of food each day either in the light or dark phase of a 14:10 light-dark cycle. Eighty-five percent of sham-ablated and 45% of SCNx hamsters displayed a preferred hour for torpor onset. In each group, time of torpor onset was not random but occurred at a mean hour that differed significantly from chance. Time of food presentation almost completely accounted for the timing of torpor onset in SCNx animals and significantly affected timing of this behavior in intact hamsters. These results suggest that the circadian pacemaker in the SCN controls the time of torpor onset indirectly by affecting timing of food intake, rather than by, or in addition to, direct neural and humoral outputs to relevant target tissues.

  3. The Last Expedition of the Siberian A.V. Adrianov (Tuva, 1915–1916

    Directory of Open Access Journals (Sweden)

    Olga B. Belikova

    2014-12-01

    Full Text Available The article presents the results of the examination of archaeological activity of Siberian public figure and scientist A.V. Adrianov (1854–1920 in his last expedition. It took place in the upstream basin of the Yenisei River – in Tuva (Uryankhaysky Kray / Tannu Uryankhay in 1915–1916. The archaeologist could not summarize and publish the results of his successful field research – he died in 1920 due to the unjustified sentence of the Bolsheviks. The expedition prehistory, the content of the archaeological excavations and exploration, the history of the materials deposition to the storage, scientist's last years have been restored. The information, concerning 23 ancient Old Turkic manuscripts, examined by A.V. Adrianov has been identified and summarized. The data on new sources have been introduced into scientific use.

  4. High-3He plume origin and temporal-spatial evolution of the Siberian flood basalts

    Science.gov (United States)

    Basu, A.R.; Poreda, R.J.; Renne, P.R.; Teichmann, F.; Vasiliev, Y.R.; Sobolev, N.V.; Turrin, B.D.

    1995-01-01

    An olivine nephelinite from the lower part of a thick alkalic ultrabasic and mafic sequence of volcanic rocks of the northeastern part of the Siberian flood basalt province (SFBP) yielded a 40ArX39Ar plateau age of 253.3 ?? 2.6 million years, distinctly older than the main tholeiitic pulse of the SFBP at 250.0 million years. Olivine phenocrysts of this rock showed 3He/4He ratios up to 12.7 times the atmospheric ratio; these values suggest a lower mantle plume origin. The neodymium and strontium isotopes, rare earth element concentration patterns, and cerium/lead ratios of the associated rocks were also consistent with their derivation from a near-cnondritic, primitive plume. Geochemical data from the 250-million-year-old volcanic rocks higher up in the sequence indicate interaction of this high-3He SFBP plume with a suboceanic-type upper mantle beneath Siberia.

  5. Half-length model of a Siberian Snake magnet for RHIC

    CERN Document Server

    Okamura, M; Kawaguchi, T; Katayama, T; Jain, A; Muratore, J; Morgan, G; Willen, E

    2000-01-01

    For the Relativistic Heavy Ion Collider (RHIC) Spin Project, super-conducting helical dipole magnets are being constructed. These magnets will be used in 'Siberian Snakes' and 'Spin Rotators', which manipulate spin direction of proton beams in RHIC. The dipole field in these magnets rotates 360 deg. and is required to reach a magnetic field strength of more than 4.0 T. The bore radius of the coils and the magnetic length of the magnets are 50 and 2400 mm, respectively. To ascertain the performance of these magnets, which are built using a new 'coil in a slot' technique, a half-length model has been fabricated and tested. The quench performance, field uniformity and rotation angle have been investigated. The measured values in the model magnet agreed well with field calculations. These results demonstrate the adequacy of the fabrication method adopted in the model magnet. (authors)

  6. Nanostructured lipid carriers (NLC) on the basis of Siberian pine (Pinus sibirica) seed oil.

    Science.gov (United States)

    Averina, E S; Seewald, G; Müller, R H; Radnaeva, L D; Popov, D V

    2010-01-01

    Nanostructured lipid carriers (NLC) are new drug systems composed of physiological lipid materials. The possibility of including different types of lipids into the NLC structure revealed the wide prospects for using biologically active natural oils for the development of the cutaneous preparations. In this study the formulation parameters of NLC on the basis of Siberian pine seed oil were evaluated including concentration of lipids, types of surfactants and storage conditions (4 degrees C, 20 degrees C, 40 degrees C). Size distribution and storage stability of formulations produced by hot high pressure homogenisation were investigated by laser diffractometry and photon correlation spectroscopy. The NLC were characterised by their melting behaviour using differential scanning calorimetry. The obtained data indicated the high physical stability of the developed NLC formulations.

  7. T-lymphocyte-rich thymoma and myasthenia gravis in a Siberian tiger (Panthera tigris altaica).

    Science.gov (United States)

    Allan, K; Masters, N; Rivers, S; Berry, K; Routh, A; Lamm, C

    2014-01-01

    A 10-year-old captive male Siberian tiger (Panthera tigris altaica) presented with acute onset collapse, vomiting and dyspnoea, preceded by a 6-month period of progressive muscle wasting. Following humane destruction, post-mortem examination revealed a large multilobulated mass in the cranial mediastinum, which was diagnosed as a T-lymphocyte-rich thymoma with the aid of immunohistochemistry. Retrospective serology for acetylcholine receptor antibodies (titre 3.90 nmol/l) confirmed a diagnosis of thymoma-associated myasthenia gravis. Thymomas are reported rarely in wild carnivores, but when detected they appear to be similar in morphology to those seen in domestic carnivores and may also be accompanied by paraneoplastic syndromes. The clinical signs of myasthenia gravis in the tiger were consistent with those reported in cats and dogs and the condition is proposed as an important differential diagnosis for generalized weakness in captive Felidae.

  8. Aspartic Acid Racemization and Age-Depth Relationships for Organic Carbon in Siberian Permafrost

    Science.gov (United States)

    Brinton, Karen L. F.; Tsapin, Alexandre I.; Gilichinsky, David; McDonald, Gene D.

    2002-03-01

    We have analyzed the degree of racemization of aspartic acid in permafrost samples from Northern Siberia, an area from which microorganisms of apparent ages up to a few million years have previously been isolated and cultured. We find that the extent of aspartic acid racemization in permafrost cores increases very slowly up to an age of ~25,000 years (around 5 m in depth). The apparent temperature of racemization over the age range of 0-25,000 years, determined using measured aspartic acid racemization rate constants, is -19°C. This apparent racemization temperature is significantly lower than the measured environmental temperature (-11 to -13°C) and suggests active recycling of D-aspartic acid in Siberian permafrost up to an age of around 25,000 years. This indicates that permafrost organisms are capable of repairing some molecular damage incurred while in a "dormant" state over geologic time.

  9. Morphological and electrophysiological characterization of the adult Siberian hamster optic nerve.

    Science.gov (United States)

    James, Emma L; Peacock, Veronique A H; Ebling, Francis J P; Brown, Angus M

    2010-12-01

    Electrophysiological recordings and transmission electron microscopy were used to characterize the compound action potential (CAP) and morphology, respectively, of the optic nerve in the Siberian hamster. The CAP was polyphasic in nature, comprising four separate but overlapping peaks, thereby implying that four sub-populations of axons defined by conduction velocity are present in the nerve. The histological analysis of nerves from four animals revealed a cross-sectional area of 128,171 μm(2) containing 78,109 axons. All of the axons were myelinated, and measurements of axon surface area revealed values ranging from 0.09 to 9.92 μm(2), although 68.3% were 2.5 μm(2)) were selectively distributed throughout the nerve. We conclude that the CAP recorded from hamster optic nerve displays four distinct peaks; however, morphological analysis failed to reveal a similar distribution of axon sizes.

  10. Photoperiod affects distribution of dynorphin A in the brain of Siberian hamster.

    Science.gov (United States)

    Meyza, Ksenia Z; Sotowska-Brochocka, Jolanta

    2006-01-01

    Dynorphin A1-77 (DYN A1-17) acting in the CNS is known to affect thermoregulation, water and energy balance in the short time scale. In this study a long-term alteration of these functions induced by changes of day length in the highly photoperiodic species, the Siberian hamster (Phodopus sungorus) was studied using immunohistochemistry for DYN A1-17. We found that in the long day (LD, L:D 16 h:8 h) more brain areas express DYN A1-17 peptide than in the short day (SD, L:D 8 h:16 h) conditions. Structures of the hypothalamo-pituitary axis as well as cells of the ependyma, subcomissural organ and choroid plexus of the lateral and third brain ventricles are immunoreactive to anti-dynorphin IgG only in the LD. This might indicate a seasonal regulatory role of DYN A1-17 in physiological adaptations to severe climate changes.

  11. Influence of the Siberian larch extract on the processes of peroxide oxidation of lipids in experiment

    Directory of Open Access Journals (Sweden)

    Pateyuk Andrey

    2016-03-01

    Full Text Available In modern conditions wood processing is one of the primary branches of production in Transbaikal region. In connection with big squares of logging the question of processing and utilizing waste products directly on the spot is particularly acute. We researched the activity of water extract from sawdust of Siberian larch "Ekstrapinus" on the power exchange and processes of peroxide oxidation of lipids against immobilized stress in experiment. The data provided in the article prove that the use of Ekstrapinus extract reduces the pathological violations arising under stress. So, Ekstrapinus extract restores energy potential of cages when modeling stress, restores energy potential of cells, normalizes balance in the system "peroxide oxidation of lipids – antioxidant protection" and supports the balance of tiol in an animal organism in the state of stress. Considering absence of toxicity in the recommended doses, it is possible to recommend their application under stress.

  12. Contributions of the Siberian shelf polynyas to the Arctic Ocean intermediate and deep water

    Science.gov (United States)

    Martin, Seelye; Cavalieri, Donald J.

    1989-01-01

    To investigate the role of Siberian Shelf polynyas in water mass formation, and that of Whalers Bay in the cooling of the West Spitsbergen Current, satellite observations from the Nimbus 7 scanning multichannel microwave radiometer are used to determine the size and location of polynyas for November-March, 1978-1982. If salt contributes only to the Arctic Intermediate Water, the results show that the continental shelves can produce 20-60 percent of this water. Alternatively, if the salt contributes only to the deep water of the Eurasian Basin, then without consideration of the mixing of the bottom water with the Greenland and Norwegian Sea water, the contribution from the shelves yields a renewal time of about 100 years. These results imply that there is insufficient water produced in the shelf polynyas to perform all of the roles that have historically been assigned to it.

  13. Effects of dietary arabinoxylan-oligosaccharides (AXOS) and endogenous probiotics on the growth performance, non-specific immunity and gut micrbiota of juvenile Siberian sturgeon (Acipenser baerii)

    NARCIS (Netherlands)

    Geraylou, Z.; Souffreau, C.; Rurangwa, E.; Meester, de L.; Courtin, C.M.; Delcour, J.A.; Buyse, J.; Ollevier, F.

    2013-01-01

    We investigated the effects of administration of putative endogenous probiotics Lactococcus lactis spp. lactis or Bacillus circulans, alone and in combination with arabinoxylan-oligosaccharides (AXOS), a new class of candidate prebiotics, in juvenile Siberian sturgeon (Acipenser baerii). Eight

  14. We Have Nothing to Do with Them; They Live with Their Own Kind: Siberian Estonians’ Representations of the Neighbouring Turkic Peoples

    Directory of Open Access Journals (Sweden)

    Astrid Tuisk

    2014-08-01

    Full Text Available This article explores the representations of Estonians, an ethnic group inhabiting West Siberian villages today, of their neighbouring Turkic peoples. I discuss the way that Siberian Estonians describe the representatives of these peoples and their contacts with the latter. The analysis is based on the interviews conducted within folklore collection fieldwork, in which a common question posed by the researcher was: What do you think/know about or what contacts have you had with the representatives of Turkic peoples? Siberian Estonians’ representations of the neighbouring Turkic peoples are analysed as a creative process based on tradition and expressed by means of various folklore genres, whereas the meanings and interpretations are connected with the social and sociocultural environment. As the article is concerned with the lore of West Siberian Estonians only, it discusses the ethnic groups inhabiting this particular area – the Kazakhs and the Tatars.

  15. Late Holocene Peat Growth at the Northern Siberian Periphery and its Relation to Arctic Climate Change

    Science.gov (United States)

    Bauch, H. A.; Abramova, E.; Alenius, T.; Saarnisto, M.

    2014-12-01

    During the last postglacial evolution of the shallow northern Siberian shelf systems regional sea level in the Arctic came to its Holocene highstand some time between 5 to 6 ka. After that time a general stabilization of the sedimentary regime occurred. That is well noted in a drastic decrease in sedimentation rates observed in all sediment cores taken from middle to outer shelf water depths of the Laptev Sea. But, at water depths lower than 30 meters - i.e., in the inner shelf and nearer to the coasts - sedimentation continued at relatively higher rates, presumably due to input of terrigenous material from river runoff as well as coastal erosion. Compared with that latter process, the huge Lena Delta should comprise a region of sediment catchment where aggradation wins over erosion. However, little is known about the detailed history of this delta during the second half of the Holocene. In order to gain more insight into this issue we have investigated three islands within the Lena Delta. All of these are comprised of massive peat of several meters in thickness. Picking discrete specimens of water mosses (Sphagnum) only, we have radiocarbon-dated these peat sections. The depth/age relation of the sampled profiles reflect the growth rate of peat. It shows that the islands' history above the present-day delta-sea level is about 4000 yrs. old. Moreover, a significant change in peat growth occurred after 2500 yrs BP in both, accumulation and composition, and allows the conclusion of a major shift in Arctic environmental conditions since then. Thus, our results may add further information also for other coastal studies, as the ongoing degradation of the rather vulnerable permafrost coast in the Laptev Sea and elsewhere along the North Siberian margin is often mentioned in context with recent Arctic climate change due to global warming.

  16. Ecology of nonnative Siberian prawn (Palaemon modestus) in the lower Snake River, Washington, USA

    Science.gov (United States)

    Erhardt, John M.; Tiffan, Kenneth F.

    2016-01-01

    We assessed the abundance, distribution, and ecology of the nonnative Siberian prawn Palaemon modestus in the lower Snake River, Washington, USA. Analysis of prawn passage abundance at three Snake River dams showed that populations are growing at exponential rates, especially at Little Goose Dam where over 464,000 prawns were collected in 2015. Monthly beam trawling during 2011–2013 provided information on prawn abundance and distribution in Lower Granite and Little Goose Reservoirs. Zero-inflated regression predicted that the probability of prawn presence increased with decreasing water velocity and increasing depth. Negative binomial models predicted higher catch rates of prawns in deeper water and in closer proximity to dams. Temporally, prawn densities decreased slightly in the summer, likely due to the mortality of older individuals, and then increased in autumn and winter with the emergence and recruitment of young of the year. Seasonal length frequencies showed that distinct juvenile and adult size classes exist throughout the year, suggesting prawns live from 1 to 2 years and may be able to reproduce multiple times during their life. Most juvenile prawns become reproductive adults in 1 year, and peak reproduction occurs from late July through October. Mean fecundity (189 eggs) and reproductive output (11.9 %) are similar to that in their native range. The current use of deep habitats by prawns likely makes them unavailable to most predators in the reservoirs. The distribution and role of Siberian prawns in the lower Snake River food web will probably continue to change as the population grows and warrants continued monitoring and investigation.

  17. Photoperiod-dependent modulation of cardiac excitation contraction coupling in the Siberian hamster.

    Science.gov (United States)

    Dibb, K M; Hagarty, C L; Loudon, A S I; Trafford, A W

    2005-03-01

    In mammals, changes in photoperiod regulate a diverse array of physiological and behavioral processes, an example of which in the Siberian hamster (Phodopus sungorus) is the expression of bouts of daily torpor following prolonged exposure to a short photoperiod. During torpor, body temperature drops dramatically; however, unlike in nonhibernating or nontorpid species, the myocardium retains the ability to contract and is resistant to the development of arrhythmias. In the present study, we sought to determine whether exposure to a short photoperiod results in alterations to cardiac excitation-contraction coupling, thus potentially enabling the heart to survive periods of low temperature during torpor. Experiments were performed on single ventricular myocytes freshly isolated from the hearts of Siberian hamsters that had been exposed to either 12 wk of short-day lengths (SD) or 12 wk of long-day lengths (LD). In SD-acclimated animals, the amplitude of the systolic Ca(2+) transient was increased (e.g., from 142 +/- 17 nmol/l in LD to 229 +/- 31 nmol/l in SD at 4 Hz; P < 0.001). The increased Ca(2+) transient amplitude in the SD-acclimated animals was not associated with any change in the shape or duration of the action potential. However, sarcoplasmic reticulum Ca(2+) content measured after current-clamp stimulation was increased in the SD-acclimated animals (at 4 Hz, 110 +/- 5 vs. 141 +/- 15 mumol/l, P < 0.05). We propose that short photoperiods reprogram the function of the cardiac sarcoplasmic reticulum, resulting in an increased Ca(2+) content, and that this may be a necessary precursor for maintenance of cardiac function during winter torpor.

  18. Leptin mediates seasonal variation in some but not all symptoms of sickness in Siberian hamsters.

    Science.gov (United States)

    Carlton, Elizabeth D; Demas, Gregory E

    2014-11-01

    Many seasonally breeding species, including Siberian hamsters (Phodopus sungorus), exhibit seasonal variation in sickness responses. One hypothesis regarding the mechanism of this variation is that sickness intensity tracks an animal's energetic state, such that sickness is attenuated in the season that an animal has the lowest fat stores. Energetic state may be signaled via leptin, an adipose hormone that provides a signal of fat stores. Siberian hamsters respond to extended housing in short, winter-like days by reducing fat stores and leptin levels, relative to those housed in long, summer-like days. Sickness responses are also attenuated in short-day hamsters as compared to long-day hamsters. We hypothesized that leptin provides a physiological signal by which seasonally breeding animals modulate sickness responses, such that animals with higher leptin levels show increased sickness intensity. To test this, we provided short-day hamsters with a long-day-like leptin signal and assessed their responses to lipopolysaccharide (LPS), a sickness-inducing antigen. We compared these responses to short-day vehicle-, long-day vehicle-, and long-day leptin-treated hamsters. Unexpectedly, LPS induced a hypothermic response (rather than fever) in all groups. Short-day vehicle-treated hamsters exhibited the greatest LPS-induced hypothermia, and leptin treatment attenuated this response, making hypothermia more long-day-like. Contrary to our hypothesis, short-day leptin-treated hamsters showed the least pronounced LPS-induced anorexia among all groups. These results suggest that leptin may mediate some but not all aspects of seasonal sickness variation in this species. Future studies should be targeted at determining roles of other energetic hormones in regulating seasonal sickness response variation.

  19. Daily variations in the influence of noradrenaline on preferred ambient temperature of the Siberian hamster.

    Science.gov (United States)

    Jefimow, Małgorzata; Wojciechowski, Michał; Tegowska, Eugenia

    2003-04-01

    Daily variations in sensitivity to noradrenaline (NA) and the activation of nonshivering thermogenesis (NST) are important for survival under a potentially wide range of environmental conditions. However, little is known regarding the ability of the Siberian hamster and other species to activate NST in the day and night when they may be subjected to marked variations in environmental temperature. In this study, the effects of acclimation temperature and time of day on the behavioral thermoregulatory response to NA injections in Siberian hamsters (Phodopus sungorus) was investigated. Hamsters were acclimated for 4 weeks to 23 degrees C and a L:D 12:12 h photoperiod. After acclimation, preferred ambient temperatures (PT(a)) in saline- and NA-injected animals were measured continuously in the temperature gradient system. NA (0.6 mg/kg; s.c.) was given every 4 h while PT(a) was monitored. After NA injections there was a rapid drop in PT(a), decreasing to approximately 15 degrees C within 10-20 min after each NA injection. Following 4 weeks of acclimation to 10 degrees C and a L:D 8:16 h photoperiod, the same hamsters were re-tested in the temperature gradient system. Cold acclimation led to an accentuation in the behavioral response with a decrease in PT(a) of approximately 10 degrees C. The maximal decrease in preferred ambient temperatures was recorded during the light phase of the day and during the second part of the night. Lowering of PT(a) after NA allows for rapid dissipation of the heat from NST. Overall, the behavioral response reflects the daily changes in brown adipose tissue sensitivity to NA and thus capacity for NST.

  20. Photoperiodic regulation of satiety mediating neuropeptides in the brainstem of the seasonal Siberian hamster (Phodopus sungorus).

    Science.gov (United States)

    Helwig, Michael; Archer, Zoë A; Heldmaier, Gerhard; Tups, Alexander; Mercer, Julian G; Klingenspor, Martin

    2009-07-01

    Central regulation of energy balance in seasonal mammals such as the Siberian hamster is dependent on the precise integration of short-term satiety information arising from the gastrointestinal tract with long-term signals on the status of available energy reserves (e.g. leptin) and prevailing photoperiod. Within the central nervous system, the brainstem nucleus of the solitary tract (NTS) and the parabrachial nucleus (PBN) are major relay nuclei that transmit information from the gastrointestinal tract to higher forebrain centres. We extended studies on the seasonal programming of the hypothalamus to examine the effect of the photoperiod on neuropeptidergic circuitries of this gut-brain axis. In the NTS and PBN we performed gene expression and immunoreactivity (-ir) studies on selected satiety-related neuropeptides and receptors: alpha-melanocyte stimulating hormone, melanocortin-3 receptor, melanocortin-4 receptor (MC4-R), growth hormone secretagogue-receptor, cocaine- and amphetamine-regulated transcript, preproglucagon (PPG), glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), peptide YY, galanin, neurotensin, and corticotrophin releasing hormone (CRH). Gene expression of PPG and MC4-R, and -ir of CCK and GLP-1, in the NTS were up-regulated after 14 weeks in long-day photoperiod (16 h light:8 h dark) compared to short-days (8 h light:16 h dark), whereas CRH-ir and NT-ir were increased in short-days within the PBN. We suggest that brainstem neuroendocrine mechanisms contribute to the long-term regulation of body mass in the Siberian hamster by a photoperiod-related modulation of satiety signalling.

  1. Evidence for a direct effect of melatonin on mitochondrial genome expression of Siberian hamster brown adipocytes.

    Science.gov (United States)

    Prunet-Marcassus, B; Ambid, L; Viguerie-Bascands, N; Pénicaud, L; Casteilla, L

    2001-03-01

    Photoperiod variations are known to participate in the regulation of energy balance in different rodent species via melatonin, a neurosecretory product synthesized by the pineal gland during the night. A direct effect of melatonin on adipose tissue has been suggested since binding sites for the indole have been described on brown adipocytes. The aim of this study was to investigate a genetic effect of melatonin on isolated Siberian hamster brown adipocytes using differential display RT-PCR (DDRT-PCR). Brown adipose cells were isolated from brown adipose tissue and treated for 3 hr with 0.1 and 10 microM melatonin. Total RNA was extracted and DDRT-PCR experiments were performed. A differential band, which disappeared after melatonin treatment, was detected. After confirmation and cloning, the corresponding cDNA fragment B18 was sequenced. B18 had 85 and 81% similarity with a portion of rat and mouse cytochrome b mRNA, respectively, suggesting that B18 corresponds to hamster cytochrome b. This hypothesis was confirmed by the close parallel between the changes in mRNA content, detected by B18, and by cytochrome b mRNA content, detected by a rat probe. Cytochrome b mRNA is encoded by the mitochondrial genome, suggesting a similar effect of melatonin on the whole mitochondrial transcripts. Indeed, 3 hr of treatment with melatonin (10 nM and 0.1 microM) decreased by 44% mitochondrial transcript contents. This work constitutes the first evidence of a direct biological effect of melatonin on Siberian hamster brown adipocytes.

  2. Matrix metalloproteinase inhibition influences aspects of photoperiod stimulated ovarian recrudescence in Siberian hamsters.

    Science.gov (United States)

    Shahed, Asha; Simmons, Jamie J; Featherstone, Sydney L; Young, Kelly A

    2015-05-15

    Blocking matrix metalloproteinase (MMP) activity in vivo with inhibitor GM6001 impedes photostimulated ovarian recrudescence in photoregressed Siberian hamsters. Since direct and indirect effects of MMPs influence a myriad of ovarian functions, we investigated the effect of in vivo MMP inhibition during recrudescence on ovarian mRNA expression of steroidogenic acute regulatory protein (StAR), 3β-hydroxysteroid dehydrogenase (3β-HSD), Cyp19a1 aromatase, epidermal growth factor receptor (EGFR), amphiregulin (Areg), estrogen receptors (Esr1 and Esr2), tissue inhibitors of MMPs (TIMP-1,-2,-3), proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor A (VEGFA), its receptor VEGFR-2, and angiopoietin-2 (Ang-2). Female Siberian hamsters were randomly assigned to one of four photoperiod groups: stimulatory long (LD) or inhibitory short (SD) photoperiods, or transferred from SD to LD for 2 weeks (post-transfer, PT). Half of the PT hamsters were injected (ip) daily with GM6001 (PTG). SD exposure reduced ovarian StAR, 3β-HSD, Cyp19a1, Esr1, Esr2, TIMPs 2-3, PCNA, VEGFR-2 and Ang-2 mRNA expression (p<0.05), and 2 weeks of photostimulation restored mRNA expression of 3β-HSD and PCNA and increased Areg and VEGFA mRNA expression in the PT group. GM6001 treatment during photostimulation (PTG) increased TIMP-1, -2 and -3 and PCNA mRNA, but inhibited Areg mRNA expression compared to PT. Neither photoperiod nor GM6001 altered EGFR expression. Results of this study suggest that in vivo inhibition of MMP activity by GM6001 may impede ovarian recrudescence, particularly follicular growth, in two ways: (1) directly by partially inhibiting the release of EGFR ligands like Areg, thereby potentially affecting EGFR activation and its downstream pathway, and (2) indirectly by its effect on TIMPs which themselves can affect proliferation, angiogenesis and follicular growth.

  3. Ecology of nonnative Siberian prawn (Palaemon modestus) in the lower Snake River, Washington, USA

    Science.gov (United States)

    Erhardt, John M.; Tiffan, Kenneth F.

    2016-01-01

    We assessed the abundance, distribution, and ecology of the nonnative Siberian prawn Palaemon modestus in the lower Snake River, Washington, USA. Analysis of prawn passage abundance at three Snake River dams showed that populations are growing at exponential rates, especially at Little Goose Dam where over 464,000 prawns were collected in 2015. Monthly beam trawling during 2011–2013 provided information on prawn abundance and distribution in Lower Granite and Little Goose Reservoirs. Zero-inflated regression predicted that the probability of prawn presence increased with decreasing water velocity and increasing depth. Negative binomial models predicted higher catch rates of prawns in deeper water and in closer proximity to dams. Temporally, prawn densities decreased slightly in the summer, likely due to the mortality of older individuals, and then increased in autumn and winter with the emergence and recruitment of young of the year. Seasonal length frequencies showed that distinct juvenile and adult size classes exist throughout the year, suggesting prawns live from 1 to 2 years and may be able to reproduce multiple times during their life. Most juvenile prawns become reproductive adults in 1 year, and peak reproduction occurs from late July through October. Mean fecundity (189 eggs) and reproductive output (11.9 %) are similar to that in their native range. The current use of deep habitats by prawns likely makes them unavailable to most predators in the reservoirs. The distribution and role of Siberian prawns in the lower Snake River food web will probably continue to change as the population grows and warrants continued monitoring and investigation.

  4. WARMER URBAN CLIMATES FOR DEVELOPMENT OF GREEN SPACES IN NORTHERN SIBERIAN CITIES

    Directory of Open Access Journals (Sweden)

    Igor Esau

    2016-01-01

    Full Text Available Modern human societies have accumulated considerable power to modify their environment and the earth’s system climate as the whole. The most significant environmental changes are found in the urbanized areas. This study considers coherent changes in vegetation productivity and land surface temperature (LST around four northern West Siberian cities, namely, Tazovsky, Nadym, Noyabrsk and Megion. These cities are located in tundra, forest-tundra, northern taiga and middle taiga bioclimatic zones correspondingly. Our analysis of 15 years (2000–2014 Moderate Resolution Imaging Spectroradiometer (MODIS data revealed significantly (1.3 °C to 5.2 °C warmer seasonally averaged LST within the urbanized territories than those of the surrounding landscapes. The magnitude of the urban LST anomaly corresponds to climates found 300–600 km to the South. In the climate change perspective, this magnitude corresponds to the expected regional warming by the middle or the end of the 21st century. Warmer urban climates, and specifically warmer upper soil layers, can support re-vegetation of the disturbed urban landscapes with more productive trees and tall shrubs. This afforestation is welcome by the migrant city population as it is more consistent with their traditional ecological knowledge. Survival of atypical, southern plant species encourages a number of initiatives and investment to introduce even broader spectrum of temperate blossoming trees and shrubs in urban landscapes. The unintended changes of the urban micro-climates in combination with knowledgeable urban planning could transform the Siberian pioneer settlements into places of belonging.

  5. Maritza East 1 presentation

    Energy Technology Data Exchange (ETDEWEB)

    Crespi, M.; Haillet, J.-M.; Casier, F. [ALSTOM Power (Italy). Enviornmental Control Systems

    2007-07-01

    The paper describes the project to develop a 670 MW gross and 600 MW net lignite-fired power plant, the AES-3C Maritza East 1, to be realised adjacent to the site of the existing Maritza East 1 power plant. The site is 40 kilometres south-east of Stara Zagora and 250 km south-east of Sofia, Bulgaria. The project will be more efficient and have lower emissions of sulphur dioxide per MW of electricity generated than the existing Maritza East 1 facility. The facility will have low NOx emissions, an electrostatic precipitator to control the emissions of particular matter and a flue gas desulfurization system to control emissions of sulphur dioxide. The AES 3-C Maritza East 1 plant meets all emissions criteria as defined by the Bulgarian Government, the EU and all other relevant authorities unlike the plants at Maritza East 2 and 1 which will either have to retrofit abatement technology in the next few years or face the prospect of limited hours operation and eventual closure after 2008. The new facility will have zero discharge of waste water. Condenser cooling will be provided by a natural draught cooling tower fed in part by process waters. This recycling of water for the cooling tower will significantly reduce the amount of water withdrawn from the lake. In addition, cooling tower blowdown and other potential facility discharges will be used within the wet limestone flue gas desulfurization system. ALSTOM has paid careful attention to all the different aspects involved: minimisation of environmental impact for both air, water and soil by applying state of the art technologies in all the different areas of the project and, at the same time, delivering an economically profitable installation. 2 ills.

  6. Multibeam sonar mapping of Siberian seeps: Evaluating trends in methane flux from shallow sub-sea permafrost

    Science.gov (United States)

    Stubbs, Christopher; Leifer, Ira; Luyendyk, Bruce; Semiletov, Igor

    2010-05-01

    The East Siberian Arctic Shelf (ESAS) contains an estimated 1400 GT (109 tons = 1 GT) of carbon sequestered within and beneath a sub-sea permafrost unit that is overlain by thin sediments. This carbon pool includes methane (CH4) as free and dissolved gas, potentially extensive methane hydrate deposits, and carbon dioxide (CO2), yet its contribution has traditionally been ignored in global carbon stocks because of its assumed stability. The ESAS is very shallow averaging loss have been identified from widespread bubble ebullition and enhanced aqueous methane levels well above atmospheric equilibrium. The resulting thaw sediments (taliks) and structural breaches facilitate fluid and gas migration within the permafrost to overlying sediments where some microbial methane oxidation occurs. These destabilizing features may also provide a mechanism for enhanced heat transfer to methane hydrate deposits. The shallow nature of the ESAS means ascending bubbles in the water column experience minimal dissolution before venting to the atmosphere. Additionally, storm mixing extends to the seabed so that virtually all dissolved methane gas from bubbles and sediment fluid exchange is stripped from the oceanic waters and vented to the atmosphere prior to the microbial oxidation. Emission of CH4 and CO2 largely remain unquantified but potentially contribute significantly to atmospheric budgets. Further, rapid Arctic warming suggests these gas emissions could present a significant positive warming feedback. Given the rapid climate changes occurring and predicted to occur in the Arctic, there is a strong need for baseline measurements of ebullition to allow identification of emission trends. Baseline data were collected in Fall 2009 using multibeam sonar surveying techniques developed at UCSB. Data analysis has identified spatial and temporal controls on seepage bubble flux including geologic structure, and currents. Two sonar techniques were used in the ESAS. The first method used a

  7. Nature's knockout: the Mel1b receptor is not necessary for reproductive and circadian responses to melatonin in Siberian hamsters.

    Science.gov (United States)

    Weaver, D R; Liu, C; Reppert, S M

    1996-11-01

    The pineal hormone melatonin regulates seasonal reproduction and influences the timing of circadian rhythms. The Mel1a and Mel1b receptors are the high-affinity melatonin receptors present in mammals. Unexpectedly, the Mel1b receptor gene of the Siberian hamster, Phodopus sungorus, cannot encode a functional receptor; two nonsense mutations are present within the coding region. Southern blot analysis indicates that this is a single copy gene. The Mel1b receptor gene is nonfunctional in outbred populations of P. sungorus and Phodopus campbelli. Siberian hamsters lacking a functional Mel1b receptor nevertheless show seasonal reproductive and circadian responses to melatonin, indicating that the Mel1b receptor is not necessary for these responses. These data support the hypothesis that the Mel1a receptor, which does encode a functional receptor in this species, mediates reproductive and circadian responses to melatonin.

  8. ASSESSMENT OF ANTITUBERCULOSIS CARE TO CHILDREN AND ADOLESCENTS IN THE SIBERIAN FEDERAL DISTRICT IN 2010-2012

    Directory of Open Access Journals (Sweden)

    I. V. Pavlenok

    2014-01-01

    Full Text Available The children and adolescents of the Siberian Federal District continue to have high tuberculosis morbidity rates that are 1.5-1.7 times greater than the average Russian rate. The severe clinical pattern of tuberculosis is noted among new tuberculosis cases. Preventive measures are insufficiently effective.To improve the quality of antituberculosis care to the children and adolescents of the Siberian Federal District, it is necessary to coordinate the work of a specialized and general health service on the specific prevention and early detection of tuberculosis among the children and adolescents; to solve the problem associated with discontacts in the everyday foci of tuberculosis infection; to improve the material and technical basis of children’s sanatoria; to observe infection control measures in children’s hospitals and units (to allow for the reconstruction of existing buildings and the construction of new ones; and to brisk up the work on sanitary education of the population. 

  9. Certain Results of Measurements of Characteristics of Stratospheric Aerosol Layer and Total Ozone Content at Siberian Lidar Station in Tomsk

    Directory of Open Access Journals (Sweden)

    Nevzorov Aleksey

    2016-01-01

    Full Text Available We consider the results of long-term remote optical monitoring, obtained at the Siberian Lidar Station of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences in Tomsk (56.5°N, 85.0°E. The scattering characteristics of stratospheric aerosol layer, obtained according to data of lidar measurements since 1986, are presented. We analyze the trends of changes in the total ozone (TO content over Tomsk for the period 1996-2013 according to data of spectrophotometric measurements with employment of Total Ozone Mapping Spectrometer (TOMS data for the period 1979-1994. We determined the periods of elevated content of stratospheric aerosol over Tomsk aftera series of explosive eruptions of volcanoes of Pacific Ring of Fire and Iceland in 2006-2011. Since the second half of 1990s, we record an increasing TO trend, equaling 0.65 DU/yr for the period 1996-2013.

  10. Certain Results of Measurements of Characteristics of Stratospheric Aerosol Layer and Total Ozone Content at Siberian Lidar Station in Tomsk

    Science.gov (United States)

    Nevzorov, Aleksey; Bazhenov, Oleg; Burlakov, Vladimir; Dolgii, Sergey

    2016-06-01

    We consider the results of long-term remote optical monitoring, obtained at the Siberian Lidar Station of Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences in Tomsk (56.5°N, 85.0°E). The scattering characteristics of stratospheric aerosol layer, obtained according to data of lidar measurements since 1986, are presented. We analyze the trends of changes in the total ozone (TO) content over Tomsk for the period 1996-2013 according to data of spectrophotometric measurements with employment of Total Ozone Mapping Spectrometer (TOMS) data for the period 1979-1994. We determined the periods of elevated content of stratospheric aerosol over Tomsk aftera series of explosive eruptions of volcanoes of Pacific Ring of Fire and Iceland in 2006-2011. Since the second half of 1990s, we record an increasing TO trend, equaling 0.65 DU/yr for the period 1996-2013.

  11. Artificial light at night alters delayed-type hypersensitivity reaction in response to acute stress in Siberian hamsters.

    Science.gov (United States)

    Bedrosian, Tracy A; Aubrecht, Taryn G; Kaugars, Katherine E; Weil, Zachary M; Nelson, Randy J

    2013-11-01

    Several physiological and behavioral processes rely on precisely timed light information derived from the natural solar cycle. Using this information, traits have adapted to allow individuals within specific niches to optimize survival and reproduction, but urbanization by humans has significantly altered natural habitats. Nighttime light exposure alters immune function in several species, which could lead to decreased fitness or survival, particularly in the face of an environmental challenge. We exposed male Siberian hamsters (Phodopus sungorus) to five lux of light at night for four weeks, and then administered six hours of acute restraint stress. Delayed-type hypersensitivity (DTH) response was assessed immediately following stress. Acute restraint increased the DTH reaction in dark nights, but exposure to nighttime light prevented this response. Exposure to light at night prolonged the DTH response in non-stressed control hamsters. These results suggest that light pollution may significantly alter physiological responses in Siberian hamsters, particularly in response to a salient environmental challenge such as stress.

  12. A new dynamical index for classification of cold surge types over East Asia

    Science.gov (United States)

    Park, Tae-Won; Ho, Chang-Hoi; Jeong, Jee-Hoon; Heo, Jin-Woo; Deng, Yi

    2015-11-01

    The cold surges over East Asia can be classified into wave-train type and blocking type according to their dynamic origins. In the present study, two dynamic indices are proposed to objectively identify cold surge types using potential temperature ( θ) on the dynamic tropopause at 2-potential vorticity units (2-PVU) surface. The two indices are designed to represent primary characteristics of the two types of cold surge. The wave-train index ( WI) is defined as a difference of anomalous θ on the 2-PVU surface between the western North Pacific and northeast China, which captures a southward (northward) intrusion of cold (warm) air mass related to the trough-ridge pattern. The blocking index ( BI) is defined as a difference of anomalous θ between the subarctic region and northeast China, which indicates air mass overturning related to a reversal of the usual meridional θ gradient commonly observed in the occurrence of blocking type cold surge. Composite analyses based on the distribution of the WI and BI clearly demonstrate the dynamic evolutions of corresponding cold surge types. The wave-train cold surge is associated with a southeastward expansion of the Siberian High and northerly wind near surface, which is caused by growing baroclinic waves. During the blocking cold surge, a geopotential height dipole indicating the subarctic blocking and deepening of East Asian coastal trough induces a southward expansion of the Siberian High and northeasterly wind. Compared to the wave-train type, the blocking cold surge exhibits a longer duration and stronger intensity. In the new framework of these dynamic indices, we can detect a third type of cold surge when both the wave-train and the blocking occur together. In addition, we can exclude the events that do not have the essential features of the upper tropospheric disturbances or the subarctic anticyclonic circulation, which are responsible for cold surge occurrence, using the new indices.

  13. Genetic diversity of Siberian stone pine under introduction in the South Urals and Bashkir Cis-Urals

    Directory of Open Access Journals (Sweden)

    Z. Kh. Shigapov

    2016-10-01

    Full Text Available Allozyme polymorphism of Siberian stone pine Pinus sibirica Du Tour has been studied in 14 artificial stands in the South Urals and Bashkir Cis-Urals on the base of 7 gene-enzyme system analysis. The following values of genetic diversity are determined: mean number of alleles per locus (A constitutes 1.69±0.08; portion of polymorphic loci (P95 – 50.0 %; the average expected heterozygosity (He – 0.121±0.015; the average observed heterozygosity (Ho – 0.127±0.017.The level of genetic variability in artificial stands of Siberian stone pine in the region is somewhat inferior to that in natural populations of the species. The highest genotype heterozygosity is determined in high-productive 110 year-old artificial stand in the South Urals (Beloretsky-2 site, and also in Ufimsky and Mishkinsky sites in Bashkir Cis-Urals. The lowest heterozygosity values are revealed in Birsky and Tuimazinsky sites characterized by the weakened vital state of individuals. In total we can speak about the maintenance of essential part of the species’ genetic polymorphism under introduction, especially in some stands. Genetic similarity of the studied stands is shown: inter-sample component of the total genetic diversity (FST constitutes 2.2 %, the average Nei’s genetic distance (D – 0.0033±0.00023, that is also typical of natural populations of Siberian stone pine in the species range. The obtained data about the genetic variability level of artificial stands in a complex with forestry characteristics give evidence of the successful species introduction in the region and the necessity of resumption of works on Siberian stone pine culture establishment in an industrial scale.

  14. De novo transcriptomic analysis and development of EST-SSR markers in the Siberian tiger (Panthera tigris altaica).

    Science.gov (United States)

    Lu, Taofeng; Sun, Yujiao; Ma, Qin; Zhu, Minghao; Liu, Dan; Ma, Jianzhang; Ma, Yuehui; Chen, Hongyan; Guan, Weijun

    2016-12-01

    The Siberian tiger, Panthera tigris altaica, is an endangered species, and much more work is needed to protect this species, which is still vulnerable to extinction. Conservation efforts may be supported by the genetic assessment of wild populations, for which highly specific microsatellite markers are required. However, only a limited amount of genetic sequence data is available for this species. To identify the genes involved in the lung transcriptome and to develop additional simple sequence repeat (SSR) markers for the Siberian tiger, we used high-throughput RNA-Seq to characterize the Siberian tiger transcriptome in lung tissue (designated 'PTA-lung') and a pooled tissue sample (designated 'PTA'). Approximately 47.5 % (33,187/69,836) of the lung transcriptome was annotated in four public databases (Nr, Swiss-Prot, KEGG, and COG). The annotated genes formed a potential pool for gene identification in the tiger. An analysis of the genes differentially expressed in the PTA lung, and PTA samples revealed that the tiger may have suffered a series of diseases before death. In total, 1062 non-redundant SSRs were identified in the Siberian tiger transcriptome. Forty-three primer pairs were randomly selected for amplification reactions, and 26 of the 43 pairs were also used to evaluate the levels of genetic polymorphism. Fourteen primer pairs (32.56 %) amplified products that were polymorphic in size in P. tigris altaica. In conclusion, the transcriptome sequences will provide a valuable genomic resource for genetic research, and these new SSR markers comprise a reasonable number of loci for the genetic analysis of wild and captive populations of P. tigris altaica.

  15. Spin motion at and near orbital resonance in storage rings with Siberian snakes I. At orbital resonance

    Energy Technology Data Exchange (ETDEWEB)

    Barber, D.P.; Vogt, M.

    2006-12-15

    Here, and in a sequel, we invoke the invariant spin field to provide an in-depth study of spin motion at and near low order orbital resonances in a simple model for the effects of vertical betatron motion in a storage ring with Siberian Snakes. This leads to a clear understanding, within the model, of the behaviour of the beam polarization at and near so-called snake resonances in proton storage rings. (orig.)

  16. New data on the structure of the Kas Block in the basement of the West Siberian Plate

    Science.gov (United States)

    Kheraskova, T. N.; Kaplan, S. A.; Bubnov, V. P.; Galuev, V. I.

    2013-03-01

    A new concept concerning the structure and stages of evolution of the Kas Block of the West Siberian Plate is stated in this paper. The Kas Block is traditionally considered to be a subsided western margin of the Siberian Platform. The new concept is based on the results of the interpretation of the geophysical data recently obtained along the reference and regional profiles in this territory. The geological interpretation of the deep dynamic sections obtained by reprocessing of the CDP seismic reflection records has been performed for the first time. The structural features of the Kas Block, as well as the character of its junction with the Siberian Platform and the Paleozoic framework, are discussed. The tectonic scheme of the territory and the scheme of the pre-Late Devonian surface of the Kas Block have been compiled. The Baikalian age of the basement of the Kas Block is substantiated. The Salairian allochthonous ophiolite-basalt tectonic nappe is localized for the first time within the sedimentary cover of the Kas Block. The available information allowed us to reconstruct the development of the western margin of the Siberian continent in the Riphean and Early Paleozoic before and after the Baikalian Orogeny, respectively. The informational background of the geological and geophysical interpretation involves the results of the CDP seismic reflection profiling, including the deep dynamic seismic sections and parameters of the P-wave velocities along the reference 1-SB seismic line and the regional Vostok 10, 12, 15, and 16 seismic lines; the results of the deep seismic and magnetotelluric soundings; the gravity measurements; the magnetic exploration; and the new coherent physical geological models.

  17. Spin motion at and near orbital resonance in storage rings with Siberian Snakes. Part I: at orbital resonance

    CERN Document Server

    Barber, D P

    2006-01-01

    Here, and in a sequel, we invoke the invariant spin field to provide an in--depth study of spin motion at and near low order orbital resonances in a simple model for the effects of vertical betatron motion in a storage ring with Siberian Snakes. This leads to a clear understanding, within the model, of the behaviour of the beam polarisation at and near so--called snake resonances in proton storage rings.

  18. Ancient DNA Analysis of the Oldest Canid Species from the Siberian Arctic and Genetic Contribution to the Domestic Dog

    OpenAIRE

    Lee, Esther J.; D Andrew Merriwether; Alexei K Kasparov; Pavel A Nikolskiy; Marina V Sotnikova; Elena Yu Pavlova; Pitulko, Vladimir V.

    2015-01-01

    Modern Arctic Siberia provides a wealth of resources for archaeological, geological, and paleontological research to investigate the population dynamics of faunal communities from the Pleistocene, particularly as the faunal material coming from permafrost has proven suitable for genetic studies. In order to examine the history of the Canid species in the Siberian Arctic, we carried out genetic analysis of fourteen canid remains from various sites, including the well-documented Upper Paleolith...

  19. Surface ultraviolet radiation over east Siberia: seasonal variations

    Directory of Open Access Journals (Sweden)

    A. V. Mikhalev

    Full Text Available The results of spectral measurements of the daily near-noon surface direct solar ultraviolet radiation in the wavelength range of 295–345 nm obtained in Irkutsk (East Siberia for the time interval of 1998–2000 are presented. For the period under consideration, the seasonal UV radiation variations are analysed that are associated with the total ozone dynamics, the transition of cyclonic and anticyclonic (Siberian anticyclone periods, the presence of snow cover, and other factors. The analysis reveals an asymmetric behaviour of the seasonal course in ground-level UV radiation around the time of the summer solstice, with seasonal variation dependence on the wavelength. We have determined the irregular variations of surface UV radiation that is typical for the region, with their properties dependent on the season and on the spectral range analysed. The similarity of the above noted features from year to year was revealed.

    Key words. Atmospheric composition and structure (Transmission and scattering of radiation; instruments and techniques – Meteorology and atmospheric dynamics (middle atmosphere dynamics

  20. East Europe Report

    Science.gov (United States)

    2007-11-02

    Plan Progress Report for CEMA Agriculture (Ngok Bin, Petr Ivashov; INTERNATIONALE ZEITSCHRIFT DER LANDWIRTSCHAFT, No 6, 1985) 1 ECONOMY...INTERNATIONAL AFFAIRS CEMA Civil Air Transport Pilot Training School Described (Dmitri Zassorov; VOLKSARMEE, No 47, 1985) 12 CZECHOSLOVAKIA Former...AFFAIRS CURRENT 5-YEAR PLAN PROGRESS REPORT FOR CEMA AGRICULTURE Moscow/East Berlin INTERNATIONALE ZEITSCHRIFT DER LANDWIRTSCHAFT in German No 6, 1985 pp

  1. JPRS Report East Europe.

    Science.gov (United States)

    2007-11-02

    Radio Broadcasts for Baltic, Ukrainian Polonia Begin [TRYBUNA 8 May] .................................... 2 YUGOSLAVIA Reasons for Tudjman’s...for Baltic, Ukrainian Polonia Elena Lagadinova, deputy chairman; Begin Khristina Pepeldzhiyska, deputy chairman; 90P20027A Warsaw TR YBUNA in Polish 8...Commission for [Text] On 7 May, Polish Radio began broadcasting Socioeconomic Development; special programs for Poles [ Polonia ] residing in the East. 2

  2. Middle East Reform Halts

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The chaos in Iraq poses a great threat to the U.S. plan in the Middle East While the fighting between Israel and Lebanon-based Hezbollah becomes fiercer, security in Iraq also keeps deteriorating, making the region a petrol can that may blow up anytime.

  3. JPRS Report, East Europe.

    Science.gov (United States)

    1988-05-02

    10 Su-22/FITTER K and 15 L-29 " Delfin " (NATO desig- nation: MAYA) from CSSR production as photo-recon- naissance aircraft. The 2 transport aircraft...aircraft within the East Bloc as well: Its trainers, the older L-29 " Delfin " (NATO code name MAYA) and the modern L-39 "Albatros," are being used by the

  4. JPRS Report, East Europe.

    Science.gov (United States)

    1990-02-05

    isolationism. Its leadership ignored the maturing thinking and the social movement in the East and in the [Interview with Cestmir Cisar by Jan Kaspar ...away into archives of erization, robotization , prognostics, cybernetics and philosophy like a fossil from an era in which we no other achievements of

  5. The East Pacific Rise

    NARCIS (Netherlands)

    NN,

    1961-01-01

    Evidence gathered by expeditions of the University of California’s Scripps Institution of Oceanography during the International Geophysical Year suggests that the East Pacific Rise is one of the largest physical structures on earth. It runs in a sickle-shaped curve from near New Zealand 8,000 miles

  6. East African institutions

    DEFF Research Database (Denmark)

    Nordby, Johannes Riber; Jacobsen, Katja

    For the past decade security in East Africa has gained focus internationally. However there is a growing ambition among African states to handle such issues by themselves, sometimes through regional institutions. This has been supported by many Western states but potential risks are often forgotten....

  7. The East Pacific Rise

    NARCIS (Netherlands)

    NN,

    1961-01-01

    Evidence gathered by expeditions of the University of California’s Scripps Institution of Oceanography during the International Geophysical Year suggests that the East Pacific Rise is one of the largest physical structures on earth. It runs in a sickle-shaped curve from near New Zealand 8,000 miles

  8. JPRS Report, East Europe.

    Science.gov (United States)

    1987-09-17

    EAST EUROPE CONTENTS POLITICAL ALBANIA Alia’s Views on Links to Masses Stressed ( Guro Zeneli; BASHKIMI, 8 Jul 87) , 1 Party Control Over Army...ALIA’S VIEWS ON LINKS TO MASSES STRESSED Tirana BASHKIMI in Albanian 8 Jul 87 p 2 [Article by Guro Zeneli: "Always with the Rhythm, the Vigor, the Will

  9. Features of formation of «developmental institutions» in Russia: a case of the Siberian regions

    Directory of Open Access Journals (Sweden)

    Kirill Sergeyevich Sablin

    2014-03-01

    Full Text Available The article is devoted to the features of the process of “developmental institutions” formation in the Siberian regions. The importance of the institutional environment and informal personalized connections affect its formation is articulated. The research is carried out according to the methodological base of public choice theory, especially — economics of bureaucracy, and the concept of D. North. Functional roles, which “developmental institutions” are performed in the Siberian regions, are disclosed: “affiliate” of the regional administration under its full organizational and financial control; “independent agent”, which expresses the interests of academic science and small innovative business; “subdivision” of federal innovative structure that promotes commercialization of innovations in the region; “conductor” of the federal level big business interests that favor large-scale projects realization in the region. As a result, different combinations of the elements of the institutional environment and informal personalized connections between subjects, who are involved in the process of “developmental institutions” formation in the Siberian regions, determine further success or “failure” of these organizational-economic structures.

  10. Effects of sex and scotorefractory state on obesity induced by photostimulation and serum leptin in Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    Cudney, Sarah E; Place, Ned J

    2012-12-01

    The rising prevalence of obesity is associated with an increasing incidence of heart disease, diabetes and other health risks. In addition, severe cases of obesity are associated with an even greater risk of morbidity and mortality. Therefore, animal models of morbid obesity are required to better elucidate the underlying mechanisms. Our investigations in the Siberian hamster (Phodopus sungorus) suggest that pronounced obesity can be reliably induced in this species without relying on genetic manipulation or overly fatty and palatable foods. In a prior study on reproductive aging in female Siberian hamsters, we incidentally observed marked obesity in a group of hamsters that were exposed to a particular photoperiodic regime. In short day (SD) lengths, Siberian hamsters inhibit their reproductive physiology and reduce food intake and body mass. However, hamsters become refractory to SD after 15-20weeks and revert to the long day (LD) phenotype. In the previous study, refractory animals appeared to be particularly sensitive to photostimulation (transfer to LD), in terms of increasing body mass. To test the hypothesis that refractoriness to SD predisposes hamsters to severe obesity, we photostimulated females and males in different states of SD responsiveness (inhibited or refractory). We determined that photostimulation during the SD-refractory state is particularly effective in inducing pronounced obesity and high serum leptin concentration in female hamsters. We propose that this experimental framework is a useful model to investigate the factors and signals that create a predisposition to excessive food intake and body mass, without having to rely on genetic or dietary manipulations.

  11. Evaluating the temporal link between Siberian Traps magmatism and the end-Permian mass extinction (Invited)

    Science.gov (United States)

    Burgess, S. D.; Bowring, S. A.

    2013-12-01

    Interest in Large Igneous Provinces as agents for massive climatic and biological change is steadily increasing, though the temporal constraints on both are seldom precise enough to allow detailed testing of a causal relationship. The end-Permian mass extinction is one of the most biologically important and intensely studied events in Earth history and has been linked to many possible trigger mechanisms, from voluminous volcanism to bolide impact. Proposed kill mechanisms range from acidic and/or anoxic oceans to a cocktail of toxic gases, although the link between trigger and kill mechanisms is unconstrained due to the lack of a high-precision timeline. Critical to assessing the plausibility of different trigger and kill mechanisms is an accurate age model for the biotic crisis and the perturbations to the global carbon cycle and ocean chemistry. Recent work using the EARTHTIME U/Pb tracer solution has refined the timing of the onset and duration of the marine mass extinction event and the earliest Triassic recovery at the GSSP for the Permian-Triassic boundary in Meishan, China. This work constrains the mass extinction duration to less than 100 kyr and provides an accurate and precise time point for the onset of extinction, against which the timing of potential trigger mechanisms may be compared. For more than two decades, eruption and emplacement of the Siberian traps has been implicated as a potential trigger of the end-Permian extinction. In this scenario, magmatism drives the biotic crisis through mobilization of volatiles from the sedimentary rock with which intruding and erupting magmas interact. Massive volatile release is believed to trigger major changes in atmospheric chemistry and temperature, both of which have been proposed as kill mechanisms. Current temporal constrains on the timing and duration of the Siberian magmatism are an order of magnitude less precise than those for the mass extinction event and associated environmental perturbations

  12. Isolation of bacteria from Siberian permafrost capable of growing under simulated Mars atmospheric pressure and composition

    Science.gov (United States)

    Nicholson, Wayne; Gilichinsky, David; Schuerger, Andrew; Mironov, Vasiliy; Fajardo-Cavazos, Patricia; Kerney, Krystal; Krivushin, Kirill; Oliveira, Rafael; Waters, Samantha

    A central goal of Astrobiology is to explore the limits at which life can occur and to search for life and habitable locations outside Earth. Mars is currently an active target in the search for life due to its relative proximity and similarity to Earth, coupled with increasing evidence pointing to the past and present existence of liquid water at the surface and near subsurface [1]. Exchange of rocky impact ejecta between Mars and Earth has been known for at least two decades [2], and evidence has accumulated supporting the hypothesis that living microorganisms embedded in rocks could survive the transfer process [3]. Understanding the ability of terrestrial microbes to grow in the near-surface martian environment is of prime importance both for life detection and for protection of Mars from forward contamination by human or robotic exploration [4]. The surface environment of Mars presents formidable challenges to life, such as: harsh solar radiation; a scarcity of liquid water and nutrients; extreme low temperatures; and a low-pressure, CO2-dominated anoxic atmosphere [5]. Our recent work has concentrated on investigating the possibility that prokaryotes from Earth could survive and proliferate in the Mars environment. Our experiments have involved environmental chambers that can simulate Mars atmospheric conditions of low pressure (P; 0.7 kPa), temperature (T; 0˚C), and a CO2-dominated anoxic atmosphere (A), called here collectively low-PTA conditions. Because much of the water on present-day Mars exists in a permanently frozen state mixed with mineral matrix, terrestrial permafrosts are considered to be analogs of the martian environment [6]. We therefore screened Siberian permafrost soils for microbes capable of growing under low-PTA conditions. Using this approach we reported the isolation of 6 Carnobacterium spp. isolates from Siberian permafrost that were capable of low-PTA growth [7]. One of these isolates has been characterized in detail and proposed as

  13. The stability of the stratospheric ozone layer during the end-Permian eruption of the Siberian Traps.

    Science.gov (United States)

    Beerling, David J; Harfoot, Michael; Lomax, Barry; Pyle, John A

    2007-07-15

    The discovery of mutated palynomorphs in end-Permian rocks led to the hypothesis that the eruption of the Siberian Traps through older organic-rich sediments synthesized and released massive quantities of organohalogens, which caused widespread O3 depletion and allowed increased terrestrial incidence of harmful ultraviolet-B radiation (UV-B, 280-315nm; Visscher et al. 2004 Proc. Natl Acad. Sci. USA 101, 12952-12956). Here, we use an extended version of the Cambridge two-dimensional chemistry-transport model to evaluate quantitatively this possibility along with two other potential causes of O3 loss at this time: (i) direct effects of HCl release by the Siberian Traps and (ii) the indirect release of organohalogens from dispersed organic matter. According to our simulations, CH3Cl released from the heating of coals alone caused comparatively minor O3 depletion (5-20% maximum) because this mechanism fails to deliver sufficiently large amounts of Cl into the stratosphere. The unusual explosive nature of the Siberian Traps, combined with the direct release of large quantities of HCl, depleted the model O3 layer in the high northern latitudes by 33-55%, given a main eruptive phase of less than or equal to 200kyr. Nevertheless, O3 depletion was most extensive when HCl release from the Siberian Traps was combined with massive CH3Cl release synthesized from a large reservoir of dispersed organic matter in Siberian rocks. This suite of model experiments produced column O3 depletion of 70-85% and 55-80% in the high northern and southern latitudes, respectively, given eruption durations of 100-200kyr. On longer eruption time scales of 400-600kyr, corresponding O3 depletion was 30-40% and 20-30%, respectively. Calculated year-round increases in total near-surface biologically effective (BE) UV-B radiation following these reductions in O3 layer range from 30-60 (kJm(-2)d(-1))BE up to 50-100 (kJm(-2)d(-1))BE. These ranges of daily UV-B doses appear sufficient to exert mutagenic

  14. Superb winter fur insulation in the small Siberian musk deer (Moschus moschiferus

    Directory of Open Access Journals (Sweden)

    Arnoldus Schytte Blix

    2015-10-01

    Full Text Available We compared the morphology and thermal characteristics of winter pelage from two Siberian musk deer Moschus moschiferus (aged 5 and 41 mo.; 5.7 and 9.5 kg and two Eurasian reindeer Rangifer tarandus tarandus (aged >48 mo.; 73 and 79 kg.  The depth of the fur over the back of musk deer was less (approximately 30 mm than in reindeer (approximately 40 mm.  Guard hairs of musk deer were longer (mean = 50.0 mm and had greater diameter at half-length (mean = 314.4 μm than those of reindeer (mean = 38.6mm and = 243.9 μm, respectively.  The thermal characteristics (thermal conductivity and resistance of the winter pelage of the two species were nevertheless similar (0.057 W·m-1·K-1 and 0.79 K·m2·W-1; and 0.037 W·m-1 ·K-1 and 1.00 K·m2·W-1, respectively despite a tenfold difference in their body mass.

  15. Intersex gonad differentiation in cultured Russian (Acipenser gueldenstaedtii) and Siberian (Acipenser baerii) sturgeon.

    Science.gov (United States)

    Rzepkowska, Malgorzata; Ostaszewska, Teresa; Gibala, Monika; Roszko, Marek Lukasz

    2014-02-01

    Among sturgeons, the occurrence of individuals with gonads containing both testis and ovary components is considered pathological, and such fish are described as intersex individuals or intersexes. Intersexes are observed in both wild and cultured populations of sturgeon, usually at low frequencies. In the present study, intersex Russian (Acipenser gueldenstaedtii) and Siberian (Acipenser baerii) sturgeons constituted 30% of the studied populations. Macroscopically, intersex gonads were recognizable from 500 days posthatching (dph). Initially, gonads with predominantly male characteristics (testis-ova) were observed, but in older fish gonads with predominantly female traits (ova-testis) were more frequent. Using microscopic analysis, intersex gonads were discernible by 130-200 dph. Observations of intersex germinal epithelium development and analysis of sex distribution in the study populations indicated that feminization was occurring. Histological analysis revealed that differentiation of the germinal epithelium in such gonads was accompanied by various morphological alterations (transformations) that were described using quantitative and localization criteria. The most common type of transformations, massive subepithelial transformations, was manifested by the presence of abundant female germinal tissue located under the gonad surface epithelium in the developing testis. These transformations were identified in the early development stage (100-200 dph). In this type of transformation, differentiation of female germinal tissue at the gonad surface and male tissue at the mesorchium/mesovarium resulted in complete formation of both male and female germinal epithelia within the same gonad.

  16. BVOC fluxes in Eastern Siberian larch forest growing on permafrost soils

    Science.gov (United States)

    Holst, Thomas; Kajos, Maija K.; Hakola, Hannele; Rinne, Janne; Maximov, Ayal; Maximov, Trofim; Arneth, Almut

    2010-05-01

    Emissions of biogenic volatile organic compounds (BVOC) from the boreal forest biome contribute a large precursor source for formation and growth of secondary organic aerosol, with unknown but potentially substantial effects on atmosphere and climate. However, variation in the BVOC source distribution across the boreal forests and over the course of a growing season is poorly quantified, based on a very limited number of short-term studies in northern Europe and northern America. In eastern Siberia, Larix gmelinni forests dominate an area of ca. 28 X 106ha, one quarter of the entire Eurasian boreal forest. So far, no observations of leaf or ecosystem BVOC fluxes have been reported although it has been argued that larch is a substantial emitter of monoterpenes and sesquiterpenes. We will present first results from a number of measurement campaigns performed at the Spasskaya Pad flux station (ca. 40km to the northeast of Yakutsk, 62o15'18.4''N, 129o37'07.9''E) from a larch forest growing on permafrost soils. The forest was a substantial source of monoterpenes and of methanol with maximum rates observed during warm summer periods, when temperatures at this continental location could exceed 30oC. Leaf measurements also identified substantial sesquiterpene emissions; these compounds have a low atmospheric lifetime and could not be detected with the above-canopy flux measurements. Applying measured emission factors for the entire region suggest that the Siberian larch biome is a much larger source of monoterpenes than previously thought.

  17. Increased photic sensitivity for phase resetting but not melatonin suppression in Siberian hamsters under short photoperiods.

    Science.gov (United States)

    Glickman, G L; Harrison, E M; Elliott, J A; Gorman, M R

    2014-03-01

    Light regulates a variety of behavioral and physiological processes, including activity rhythms and hormone secretory patterns. Seasonal changes in the proportion of light in a day (photoperiod) further modulate those functions. Recently, short (SP) versus long days (LP) were found to markedly increase light sensitivity for phase shifting in Syrian hamsters. To our knowledge, photoperiod effects on light sensitivity have not been studied in other rodents, nor is it known if they generalize to other circadian responses. We tested whether photic phase shifting and melatonin suppression vary in Siberian hamsters maintained under LP or SP. Select irradiances of light were administered, and shifts in activity were determined. Photic sensitivity for melatonin suppression was examined in a separate group of animals via pulses of light across a 4 log-unit photon density range, with post-pulse plasma melatonin levels determined via RIA. Phase shifting and melatonin suppression were greater at higher irradiances for both LP and SP. The lower irradiance condition was below threshold for phase shifts in LP but not SP. Melatonin suppression did not vary by photoperiod, and the half saturation constant for fitted sigmoid curves was similar under LP and SP. Thus, the photoperiodic modulation of light sensitivity for phase shifting is conserved across two hamster genera. The dissociation of photoperiod effects on photic phase shifting and melatonin suppression suggests that the modulation of sensitivity occurs downstream of the common retinal input pathway. Understanding the mechanistic basis for this plasticity may yield therapeutic targets for optimizing light therapy practices.

  18. Pregnancy-induced changes in ultradian rhythms persist in circadian arrhythmic Siberian hamsters.

    Science.gov (United States)

    Wang, Z Yan; Cable, Erin J; Zucker, Irving; Prendergast, Brian J

    2014-07-01

    The impact of pregnancy and lactation on ultradian rhythms (URs) and circadian rhythms (CRs) of locomotor activity was assessed in circadian rhythmic and arrhythmic Siberian hamsters maintained in a long-day photoperiod (16h light/day). Progressive decrements in CR robustness and amplitude over the course of gestation were accompanied by enhanced URs. Dark-phase UR period and amplitude increased during early gestation and complexity and robustness increased during late gestation. The persistence of pregnancy-associated enhancements of URs in circadian arrhythmic (ARR) hamsters suggests that reproductive modulation of the UR waveform is not dependent on coherent circadian organization. The increased incidence of dark-phase URs appeared more rapidly in ARR dams than entrained (ENTR) dams. Throughout gestation, the percentage of dams with dark-phase URs was significantly greater in the ARR group. Gestational increases in UR complexity and robustness emerged earlier and were greater in ARR than ENTR dams. The attenuation of CRs during lactation is correlated with increased expression of URs. Relaxation of circadian control of the dam's behavior may increase fitness by permitting more efficient interactions with circadian arrhythmic pups.

  19. Dissociation of ultradian and circadian phenotypes in female and male Siberian hamsters.

    Science.gov (United States)

    Prendergast, Brian J; Cisse, Yasmine M; Cable, Erin J; Zucker, Irving

    2012-08-01

    Three experiments addressed whether pronounced alterations in the circadian system yielded concomitant changes in ultradian timing. Female Siberian hamsters were housed in a 16L:8D photoperiod after being subjected to a disruptive phase-shifting protocol that produced 3 distinct permanent circadian phenotypes: some hamsters entrained their circadian rhythms (CRs) with predominantly nocturnal locomotor activity (ENTR), others displayed free-running CRs (FR), and a third cohort was circadian arrhythmic (ARR). The period of the ultradian locomotor rhythm (UR) did not differ among the 3 circadian phenotypes; neuroendocrine generation of URs remains viable in the absence of coherent circadian organization and appears to be mediated by substrates functionally and anatomically distinct from those that generate CRs. Pronounced light-dark differences in several UR characteristics in ENTR hamsters were completely absent in circadian arrhythmic hamsters. The disruptive phase-shifting protocol may compromise direct visual input to ultradian oscillators but more likely indirectly affects URs by interrupting visual afference to the circadian system. Additional experiments documented that deuterium oxide and constant light, each of which substantially lengthened the period of free-running CRs, failed to change the period of concurrently monitored URs. The resistance of URs to deuteration contrasts with the slowing of virtually all other biological timing processes, including CRs. Considered together, the present results point to the existence of separable control mechanisms for generation of circadian and ultradian rhythms.

  20. Individual differences in circadian waveform of Siberian hamsters under multiple lighting conditions.

    Science.gov (United States)

    Evans, Jennifer A; Elliott, Jeffrey A; Gorman, Michael R

    2012-10-01

    Because the circadian clock in the mammalian brain derives from a network of interacting cellular oscillators, characterizing the nature and bases of circadian coupling is fundamental to understanding how the pacemaker operates. Various phenomena involving plasticity in circadian waveform have been theorized to reflect changes in oscillator coupling; however, it remains unclear whether these different behavioral paradigms reference a unitary underlying process. To test whether disparate coupling assays index a common mechanism, we examined whether there is covariation among behavioral responses to various lighting conditions that produce changes in circadian waveform. Siberian hamsters, Phodopus sungorus, were transferred from long to short photoperiods to distinguish short photoperiod responders (SP-R) from nonresponders (SP-NR). Short photoperiod chronotyped hamsters were subsequently transferred, along with unselected controls, to 24-h light:dark:light: dark cycles (LDLD) with dim nighttime illumination, a procedure that induces bifurcated entrainment. Under LDLD, SP-R hamsters were more likely to bifurcate their rhythms than were SP-NR hamsters or unselected controls. After transfer from LDLD to constant dim light, SP-R hamsters were also more likely to become arrhythmic compared to SP-NR hamsters and unselected controls. In contrast, short photoperiod chronotype did not influence more transient changes in circadian waveform. The present data reveal a clear relationship in the plasticity of circadian waveform across 3 distinct lighting conditions, suggesting a common mechanism wherein individual differences reflect variation in circadian coupling.

  1. Pineal-independent regulation of photo-nonresponsiveness in the Siberian hamster (Phodopus sungorus).

    Science.gov (United States)

    Prendergast, B J; Freeman, D A

    1999-02-01

    The pineal hormone melatonin influences circadian rhythms and also mediates reproductive responses to photoperiod. The authors tested whether pinealectomy influences circadian oscillators responsible for induction of nonresponsiveness to short day lengths by preventing normal short-day patterns of circadian entrainment. Adult male Siberian hamsters were pinealectomized or sham operated, maintained in either 18 h light per day (18L) or 15L for 10 weeks, and then tested for responsiveness to 10L. Because pinealectomized hamsters do not show gonadal regression in short day lengths, responsiveness was assessed by measuring phase angle of entrainment and the length of the nightly activity period following transfer to 10L. The incidence of nonresponsiveness was significantly higher in 18L hamsters than in 15L hamsters but was unaffected by pineal status. Fully 88% of 18L hamsters failed to entrain to 10L in the normal short-day manner; the duration of nightly activity remained compressed, and the phase angle of entrainment was large and negative relative to lights off. The 15L hamsters entrained normally to 10L. Exposure to constant light after 10L treatment was equally effective in inducing arrhythmicity in pinealectomized and intact hamsters. Changes in the period of morning and evening circadian oscillators subsequent to 18L treatment did not predict circadian responsiveness to short photoperiod. Long-day induction of photo-nonresponsiveness, which prevents winter responses to short day lengths, occurs independently of pineal melatonin feedback on the circadian system.

  2. Dim nocturnal illumination alters coupling of circadian pacemakers in Siberian hamsters, Phodopus sungorus.

    Science.gov (United States)

    Gorman, M R; Elliott, J A

    2004-08-01

    The circadian pacemaker of mammals comprises multiple oscillators that may adopt different phase relationships to determine properties of the coupled system. The effect of nocturnal illumination comparable to dim moonlight was assessed in male Siberian hamsters exposed to two re-entrainment paradigms believed to require changes in the phase relationship of underlying component oscillators. In experiment 1, hamsters were exposed to a 24-h light-dark-light-dark cycle previously shown to split circadian rhythms into two components such that activity is divided between the two daily dark periods. Hamsters exposed to dim illumination (rhythms compared to hamsters exposed to completely dark scotophases. In experiment 2, hamsters were transferred to winter photoperiods (10 h light, 14 h dark) from two different longer daylengths (14 h or 18 h light daily) in the presence or absence of dim nighttime lighting. Dim nocturnal illumination markedly accelerated adoption of the winter phenotype as reflected in the expansion of activity duration, gonadal regression and weight loss. The two experiments demonstrate substantial efficacy of light intensities generally viewed as below the threshold of circadian systems. Light may act on oscillator coupling through rod-dependent mechanisms.

  3. West Siberian basin hydrogeology - regional framework for contaminant migration from injected wastes

    Energy Technology Data Exchange (ETDEWEB)

    Foley, M.G.

    1994-05-01

    Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in massive contamination of the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. Our long-term goal at Pacific Northwest Laboratory is to help determine future environmental and human impacts given the releases that have occurred to date and the current waste management practices. In FY 1993, our objectives were to (1) refine and implement the hydrogeologic conceptual models of the regional hydrogeology of western Siberia developed in FY 1992 and develop the detailed, spatially registered digital geologic and hydrologic databases to test them, (2) calibrate the computer implementation of the conceptual models developed in FY 1992, and (3) develop general geologic and hydrologic information and preliminary hydrogeologic conceptual models relevant to the more detailed models of contaminated site hydrogeology. Calibration studies of the regional hydrogeologic computer model suggest that most precipitation entering the ground-water system moves in the near-surface part of the system and discharges to surface waters relatively near its point of infiltration. This means that wastes discharged to the surface and near-surface may not be isolated as well as previously thought, since the wastes may be carried to the surface by gradually rising ground waters.

  4. Simulated natural day lengths synchronize seasonal rhythms of asynchronously born male Siberian hamsters.

    Science.gov (United States)

    Butler, Matthew P; Turner, Kevin W; Park, Jin Ho; Butler, James P; Trumbull, Justin J; Dunn, Sean P; Villa, Philip; Zucker, Irving

    2007-07-01

    Photoperiodism research has relied on static day lengths and abrupt transitions between long and short days to characterize the signals that drive seasonal rhythms. To identify ecologically relevant critical day lengths and to test the extent to which naturally changing day lengths synchronize important developmental events, we monitored nine cohorts of male Siberian hamsters (Phodopus sungorus) born every 2 wk from 4 wk before to 12 wk after the summer solstice in a simulated natural photoperiod (SNP). SNP hamsters born from 4 wk before to 2 wk after the solstice underwent rapid somatic and gonadal growth; among those born 4-6 wk after the solstice, some delayed puberty by many weeks, whereas others manifested early puberty. Hamsters born eight or more weeks after the solstice failed to undergo early testicular development. The transition to delayed development occurred at long day lengths, which induce early puberty when presented as static photoperiods. The first animals to delay puberty may do so predominantly on the basis of postnatal decreases in day length, whereas in later cohorts, a comparison of postnatal day length to gestational day length may contribute to arrested development. Despite differences in timing of birth and timing of puberty, autumn gonadal regression and spring gonadal and somatic growth occurred at similar calendar dates in all cohorts. Incrementally changing photoperiods exert a strong organizing effect on seasonal rhythms by providing hamsters with a richer source of environmental timing cues than are available in simple static day lengths.

  5. Timing of puberty and synchronization of seasonal rhythms by simulated natural photoperiods in female Siberian hamsters.

    Science.gov (United States)

    Butler, Matthew P; Trumbull, Justin J; Turner, Kevin W; Zucker, Irving

    2007-07-01

    The timing of puberty is a critical life history trait of short-lived species; spring-born individuals mature rapidly and breed in the season of birth, whereas young born in mid- to late summer delay puberty until the next spring. The cues that govern the transition from rapid to delayed maturation in natural populations remain unknown. To identify ecologically relevant photoperiod cues that control timing of puberty, we monitored nine cohorts of female Siberian hamsters (Phodopus sungorus) born every 2 wk from 4 wk before to 12 wk after the summer solstice in a simulated natural photoperiod (SNP). Hamsters born by the summer solstice underwent rapid somatic growth and achieved puberty that summer; among females born 2-4 wk after the solstice, some delayed puberty by many weeks, whereas others manifested early puberty. Hamsters born 6 or more weeks after the solstice generally delayed puberty until the following spring. The transition from accelerated to delayed pubertal development in the SNP occurred at day lengths that induce early puberty when presented as static photoperiods. Despite differences in timing of birth and timing of puberty, fall and subsequent spring seasonal events occurred at similar calendar dates in all cohorts. We found no evidence that prenatal photoperiod history influenced postnatal development of female hamsters. Considered together with a parallel study on males, the present findings point to sex differences in responsiveness to natural photoperiod variations. In both sexes, incrementally changing photoperiods exert a strong organizing effect on seasonal rhythms.

  6. Radial mosaic internal structure of rounded diamond crystals from alluvial placers of Siberian platform

    Science.gov (United States)

    Ragozin, A. L.; Zedgenizov, D. A.; Kuper, K. E.; Shatsky, V. S.

    2016-12-01

    The specific gray to almost black diamonds of rounded morphology are especially typical in alluvial placers of the northeastern part of the Siberian platform. The results of study of internal structure of these diamonds are presented. X-ray topography and birefringence patterns of polished plates of studied diamonds show their radial mosaic structure. Diamonds consists of slightly misorientated (up to 20') subindividuals which are combined to mosaic wedge-shaped sectors. Electron back-scatter diffraction technique has demonstrated that subindividuals are often combined in the single large blocks (subgrains). The whole crystals commonly consist of several large subgrains misoriented up to 5° to one another. The total nitrogen content of these diamonds vary in the range 900-3300 ppm and nitrogen aggregation state (NB/(NB + NA)*100) from 25 to 64 %. Rounded diamond crystals of variety V are suggested to have been formed at the high growth rate caused by the high oversaturation of carbon in the crystallization medium. It may result in the splitting of growing crystal and their radial mosaic structure as a sequence. High content of structural nitrogen defects and the great number of mechanical impurities - various mineral and fluid inclusions may also favor to generation of this structure.

  7. Major anion and cation fluxes from the Central SiberianPlateau watersheds with underlying permafrost

    Science.gov (United States)

    Kolosov, Roman R.; Prokushkin, Anatoly S.; Pokrovsky, Oleg S.

    2016-11-01

    The subarctic rivers of the Central Siberian Plateau have specific fed-characteristics due to the permafrost distribution and the active layer thawing dynamics. Two watersheds with different types of permafrost (from insular to continuous) are studied. Different data sources (Roshydromet and our own observations) are used for receiving anions’ (HCO3-, SO4 2-, Cl-) and cations’ (Ca2+, Mg2+) fluxes from the Nizhnyaya Tunguska river (1960-2011) and the Tembenchi river (1970-2011). The annual discharge of N. Tunguska for 1939-2011 is characterized by an increase of 0.3 km3/year/year, and for Tembenchi, 0.04 km3/year/year. The major part of the increase (about 60%) is due to spring flooding (May - June). The volume-weighted mean concentrations of major anions and cations in the N. Tunguska river water increased three times in the spring period (40.7 - 116.8 mg/l) and in the summer-fall period (74-212.9 mg/l). On the contrary, such concentrations decreased sharply during the winter mean water period. Due to these results, the total export of main anions and cations from the N. Tunguska river basin rose more than 4,5 times. Two possible reasons can be identified: 1) a water discharge increase of the Subarctic rivers (Peterson et al., 2002); 2) permafrost degradation induced by global climate warming (Frey and McClelland 2009).

  8. Pathologic and physiologic effects associated with long-term intracoelomic transmitters in captive Siberian sturgeon

    Science.gov (United States)

    Boone, S. Shaun; Divers, Stephen J.; Camus, Alvin C.; Peterson, Douglas C.; Jennings, Cecil A.; Shelton, James L.; Hernandez, Sonia M.

    2015-01-01

    Intracoelomic transmitters are commonly used to evaluate migratory patterns, distribution, and habitat use of many species of fish. Currently, transmitter implantation relies mostly on the assumption that transmitters do not cause any adverse physiological or pathological effects on the animal. To investigate these effects, we surgically implanted 60 Siberian Sturgeon Acipenser baeri with transmitters that weighed less than 2% of their body weight. Postoperative assessments were conducted at 1, 2, 8, 12, 26, and 55 weeks to evaluate surgical healing and transmitter retention. Blood samples were collected before and after the 55-week study for serum cortisol analysis. Overall transmitter loss was 32%. Minor to moderate adhesions were noted at necropsy but did not appear to affect organ function. One fish was noted to have an intraintestinal transmitter at necropsy, but the fish was in overall good health. Long-term transmitter presence does not appear to increase serum cortisol levels or affect overall growth more than nontransmitter fish. Although long-term telemetry studies can be undertaken with minimal concern for negative physiological or pathological effects from transmitters, researchers should be aware that transmitter loss rates may be higher than previously thought. Mechanisms for transmitter loss may include expulsion through the surgical incision, expulsion through the mucocutaneous junction between the large intestine and the vent, or intraintestinal capture and expulsion through the vent. Received February 10, 2013; accepted June 10, 2013

  9. Simultaneous Occurrence of Pancreatic Adenocarcinoma and Brunner's Gland Adenoma in a Siberian Tiger (Panthera tigris altaica).

    Science.gov (United States)

    Gombač, M; Dolenšek, T; Jaušovec, D; Kvapil, P; Švara, T; Pogačnik, M

    2015-11-01

    We describe a case of pancreatic adenocarcinoma and Brunner's gland adenoma in an 18-year-old male Siberian tiger (Panthera tigris altaica) from the Ljubljana Zoo. The tiger was humanely destroyed due to weakness and progressive weight loss. Necropsy examination revealed a large, grey, predominantly necrotic mass replacing the major part of the pancreatic body. Microscopically, the mass was unencapsulated, poorly demarcated, highly cellular and composed of highly pleomorphic, cuboidal to tall columnar cells with basal, round or oval, moderately anisokaryotic nuclei with prominent nucleoli and moderate to large amounts of eosinophilic cytoplasm. The tumour was diagnosed as pancreatic tubular adenocarcinoma with infiltration into the duodenum and mesentery. There were tumour emboli in mesenteric blood vessels and hepatic metastases. The non-affected part of the pancreas exhibited severe chronic pancreatitis. In addition, one firm white neoplastic nodule was observed in the duodenal wall. The nodule was set in the tunica muscularis and was unencapsulated, well demarcated and highly cellular, and consisted of a closely packed layer of normal Brunner's glands and a centrally positioned group of irregularly branched tubules with small amounts of debris in the lumen. The neoplastic nodule was diagnosed as Brunner's gland adenoma. The present case is, to the best of our knowledge, the first report of concurrent pancreatic adenocarcinoma and Brunner's gland adenoma, most probably induced by chronic pancreatitis, either in man or animals.

  10. Testing phylogeographic hypotheses in a Euro-Siberian cold-adapted leaf beetle with coalescent simulations.

    Science.gov (United States)

    Mardulyn, Patrick; Mikhailov, Yuri E; Pasteels, Jacques M

    2009-10-01

    Few studies to date have investigated the impact of Pleistocene climatic oscillations on the genetic diversity of cold-adapted species. We focus on the geographic distribution of genetic diversity in a Euro-Siberian boreo-montane leaf beetle, Gonioctena pallida. We present the molecular variation from three independent gene fragments over the entire geographic range of this insect. The observed sequence variation identifies a genetic diversity hot spot in the Carpathian Mountains, in central Europe, which reveals the presence of (1) an ancestral refuge population or (2) a secondary contact zone in this area. Modeling of population evolution in a coalescent framework allowed us to favor the ancestral refuge hypothesis. These analyses suggest that the Carpathian Mountains served as a refuge for G. pallida, whereas the rest of the species distribution, that spans a large portion of Europe and Asia, experienced a dramatic reduction in genetic variation probably associated to bottlenecks and/or founder events. We estimated the time of isolation of the ancestral refuge population, using an approximate Bayesian method, to be larger than 90,000 years. If true, the current pattern of genetic variation in this cold-adapted organism was shaped by a climatic event predating by far the end of the last ice age.

  11. Post-natal growth of the gastrointestinal tract of the Siberian hamster: morphometric analysis.

    Science.gov (United States)

    Wołczuk, K; Kobak, J

    2014-12-01

    Post-natal growth of the gastrointestinal tract of the Siberian hamster was studied in newborn and 3-, 7-, 14-, 21-, 42- and 90-day-old animals. Morphometric measurements and calculations were carried out: length and internal surface of gastrointestinal tract segments, size (height, width, surface) and density of villi as well as allometric growth rate of the length and internal surface of the segments with respect to the body mass. The fastest growth rate of the gastrointestinal tract segments was noticed during the first 3 days of the post-natal life. Nevertheless, significant regional differences in their growth rate were found. The increase in the length and internal surface of the large intestine was fastest, while the smallest increase was observed in the oesophagus. All segments of the gastrointestinal tract except oesophagus exhibited a positive allometric relationship to the body mass from birth till final weaning, whereas during the post-weaning period, the increase was isometric. Thus, at birth, the gastrointestinal tract segments were relatively smaller compared with those observed in adults, but then, the gastrointestinal tract grew faster than the rest of the body and reached its adult proportions just before the transition to solid food. Most probably, reaching the adult structure of the gastrointestinal tract before the final weaning is an essential condition for the proper growth of an organism after the weaning.

  12. Photoperiod and testosterone regulate androgen receptor immunostaining in the Siberian hamster brain.

    Science.gov (United States)

    Bittman, Eric L; Ehrlich, David A; Ogdahl, Justyne L; Jetton, Amy E

    2003-09-01

    Day length regulates the effects of gonadal steroids on gonadotropin secretion and behavior in seasonal breeders. To determine whether this influence of photoperiod results from changes in androgen receptor expression in Siberian hamster brain regions that regulate neuroendocrine function, androgen receptor immunostaining was examined in castrated animals given either no androgen replacement or one of three doses of testosterone (T) resulting in physiological serum concentrations. Half of the animals were housed under inhibitory photoperiod conditions, and immunostaining was quantified 11 days later. Measurement of serum gonadotropin and prolactin concentrations confirmed that androgen exerted graded effects on pituitary function but that the animals were killed before photoperiodic influences had fully developed. T significantly increased the numbers of androgen receptor-immunoreactive cells in every brain region examined. Photoperiod exerted no significant influence on androgen receptor-immunoreactive cell number in the arcuate nucleus, bed nucleus of the stria terminalis (BNST), medial preoptic nucleus, or in medial amygdala. An interaction between T and photoperiod was observed in the BNST and in the rostral and middle portions of the arcuate nucleus. Although increasing concentrations of T resulted in more intense cellular immunostaining in the BNST and arcuate, this effect was not influenced by day length. These results indicate that relatively short-duration (11 days) exposure to inhibitory photoperiod triggers localized and regionally specific changes in androgen receptor expression.

  13. Early regulation of hypothalamic arcuate nucleus CART gene expression by short photoperiod in the Siberian hamster.

    Science.gov (United States)

    Mercer, Julian G; Ellis, Claire; Moar, Kim M; Logie, Tracy J; Morgan, Peter J; Adam, Clare L

    2003-03-28

    Cocaine- and amphetamine-regulated transcript (CART) mRNA is expressed in a number of hypothalamic nuclei including the arcuate nucleus (ARC). An increase in CART gene expression in the ARC of juvenile female Siberian hamsters (Phodopus sungorus) 14 days after transfer to short photoperiod at weaning and prior to major divergence of body weight trajectory in this seasonal mammal implicates CART in the induction of programmed weight change. In the current series of experiments, elevated CART mRNA in short photoperiod juvenile female animals relative to long photoperiod controls was apparent throughout the caudal-rostral extent of the ARC after 14 days, but was not observed when short photoperiod exposure was limited to 4-7 days. Elevated CART gene expression was also observed in juvenile males 14 days after transfer to short photoperiod at weaning, in adult female hamsters 14 days after transfer to short photoperiod and in adult male hamsters 21 days after transfer to short photoperiod. There were no consistent trends in expression levels of other energy balance-related genes with these relatively short duration photoperiod manipulations, suggesting that CART may be involved in short photoperiod-programmed body weight regulation.

  14. Skeletal bone morphology is resistant to the high amplitude seasonal leptin cycle in the Siberian hamster.

    Science.gov (United States)

    Rousseau, K; Atcha, Z; Denton, J; Cagampang, F R A; Ennos, A R; Freemont, A J; Loudon, A S I

    2005-09-01

    Recent studies have suggested that the adipocyte-derived hormone, leptin, plays a role in the regulation of metabolism. Here, we tested this hypothesis in the seasonally breeding Siberian hamster, as this species exhibits profound seasonal changes in adiposity and circulating leptin concentrations driven by the annual photoperiodic cycle. Male hamsters were kept in either long (LD) or short (SD) photoperiods. Following exposure to short photoperiods for 8 weeks animals exhibited a significant weight-loss and a 16-fold reduction of serum leptin concentrations. At Week 9, animals in both photoperiods were infused with leptin or PBS via osmotic mini-pump for 14 days. Chronic leptin infusion mimicked LD-like concentrations in SD-housed animals and caused a further decline in body weight and adipose tissue. In LD-housed animals, leptin infusion resulted in a significant elevation of serum concentrations above natural LD-like levels, but had no discernable effect on body weight or overall adiposity. Both bending and compression characteristics and histomorphometric measurements of trabecular bone mass were unaltered by leptin treatment or photoperiod. Our data therefore show that despite a high natural amplitude cycle of leptin, this hormone has no apparent role in the regulation of bone metabolism, and therefore do not support recent propositions that this hormone is an important component in the metabolism of bone tissue.

  15. Diet affects resting, but not basal metabolic rate of normothermic Siberian hamsters acclimated to winter.

    Science.gov (United States)

    Gutowski, Jakub P; Wojciechowski, Michał S; Jefimow, Małgorzata

    2011-12-01

    We examined the effect of different dietary supplements on seasonal changes in body mass (m(b)), metabolic rate (MR) and nonshivering thermogenesis (NST) capacity in normothermic Siberian hamsters housed under semi-natural conditions. Once a week standard hamster food was supplemented with either sunflower and flax seeds, rich in polyunsaturated fatty acids (FA), or mealworms, rich in saturated and monounsaturated FA. We found that neither of these dietary supplements affected the hamsters' normal winter decrease in m(b) and fat content nor their basal MR or NST capacity. NST capacity of summer-acclimated hamsters was lower than that of winter-acclimated ones. The composition of total body fat reflected the fat composition of the dietary supplements. Resting MR below the lower critical temperature of the hamsters, and their total serum cholesterol concentration were lower in hamsters fed a diet supplemented with mealworms than in hamsters fed a diet supplemented with seeds. These results indicate that in mealworm-fed hamsters energy expenditure in the cold is lower than in animals eating a seed-supplemented diet, and that the degree of FA unsaturation of diet affects energetics of heterotherms, not only during torpor, but also during normothermy.

  16. An odorant-binding protein as a new allergen from Siberian hamster (Phodopus sungorus).

    Science.gov (United States)

    Torres, J A; Pastor-Vargas, C; de las Heras, M; Vivanco, F; Cuesta, Javier; Sastre, J

    2012-01-01

    A case of anaphylaxis following a bite from a Siberian hamster (SH; Phodopus sungorus) is described. Skin prick tests with hair, urine and salivary gland extracts from SH were positive, while the tests were negative for hair extracts from other rodents. IgE immunoblotting with the patient serum revealed 3 IgE-binding bands of about 18, 21 and 23 kDa. When the patient's serum was preincubated with rabbit, mouse and gerbil hair extracts, no inhibition of the 3 SH IgE-binding bands was demonstrated. Proteins extracted from the 3 bands were analyzed by N-terminal sequencing and matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry, and peptides were sequenced. IgE-binding bands were identified as being an odorant-binding protein belonging to the lipocalin family. Analysis of the 3 IgE-binding bands found in the hair, urine and salivary glands of SH showed a new allergenic protein lacking cross-reactivity with allergens from other rodents. The 3 bands likely correspond to isoforms of a single allergen.

  17. Analysis of adrenergic regulation of melatonin synthesis in Siberian hamster pineal emphasizes the role of HIOMT.

    Science.gov (United States)

    Ceinos, R M; Chansard, M; Revel, F; Calgari, C; Míguez, J M; Simonneaux, V

    2004-01-01

    Seasonal variations of environmental factors are translated into annual fluctuations in synthesis and release of melatonin, which in turn acts as a neuroendocrine messenger for the synchronization of annual functions. So far, most studies performed to understand the regulation of melatonin synthesis have used the non seasonal laboratory rat. It was demonstrated that nocturnal melatonin synthesis depends on alpha- and beta-adrenergic activation of the enzyme arylalkylamine N-acetyltransferase (AA-NAT). In this study, we investigated the mechanisms of melatonin synthesis in the Siberian hamster, a seasonal species with marked photoperiodic variation in melatonin peak duration and amplitude. A beta-adrenergic receptor agonist alone markedly stimulated AA-NAT activity and melatonin synthesis and release. An alpha-adrenergic receptor agonist, while having no effect per se, potentiated the beta-adrenergic stimulation of AA-NAT activity both in vitro and in vivo. Strikingly, the potentiation of AA-NAT activity did not result in a potentiation of melatonin synthesis, suggesting that the rate of melatonin production is limited downstream in the metabolic pathway, most probably at the level of hydroxyindole-O-methyltransferase (HIOMT). HIOMT presented a constitutively high activity that was not acutely (within hours) stimulated by beta-adrenergic agonist, but was rather up-regulated by chronic application of the agonist. This long-term beta-adrenergic regulation may explain the reported large photoperiodic variation of HIOMT activity that drives the photoperiodic variation in melatonin peak.

  18. Photoperiodic regulation of androgen receptor and steroid receptor coactivator-1 in Siberian hamster brain.

    Science.gov (United States)

    Tetel, Marc J; Ungar, Todd C; Hassan, Brett; Bittman, Eric L

    2004-11-24

    Seasonal changes in the neuroendocrine actions of gonadal steroid hormones are triggered by fluctuations in daylength. The mechanisms responsible for photoperiodic influences upon the feedback and behavioral effects of testosterone in Siberian hamsters are poorly understood. We hypothesized that daylength regulates the expression of androgen receptor (AR) and/or steroid receptor coactivator-1 (SRC-1) in specific forebrain regions. Hamsters were castrated and implanted with either oil-filled capsules or low doses of testosterone; half of the animals remained in 16L/8D and the rest were kept in 10L/14D for the ensuing 70 days. The number of AR-immunoreactive (AR-ir) cells was regulated by testosterone in medial amygdala and caudal arcuate, and by photoperiod in the medial preoptic nucleus and the posterodorsal medial amygdala. A significant interaction between photoperiod and androgen treatment was found in medial preoptic nucleus and posterodorsal medial amygdala. The molecular weight and distribution of SRC-1 were similar to reports in other rodent species, and short days reduced the number of SRC-1-ir cells in posteromedial bed nucleus of the stria terminalis (BNST) and posterodorsal medial amygdala. A significant interaction between androgen treatment and daylength in regulation of SRC-1-ir was found in anterior medial amygdala. The present results indicate that daylength-induced fluctuations in SRC-1 and AR expression may contribute to seasonally changing effects of testosterone.

  19. Extensive turnover of plant nitrogen in peats from the West Siberian Lowland

    Science.gov (United States)

    Philben, M. J.; Kaiser, K.; Benner, R. H.

    2012-12-01

    Nitrogen cycling in peatlands is of great interest because N is scarce in peatlands and may limit both primary production and microbial decomposition. The amino acid hydroxyproline (Hyp) was used to determine the proportion of peat N derived from plants in two peat cores collected from the West Siberian Lowland, Russia. Hyp is an effective tracer of plant N because plants are its only significant source in peats. In addition, its reactivity is similar to that of bulk plant N, so its yield in peat can be used to quantitatively estimate plant N. The C:N ratio of the peat was very high (>70) throughout both cores. As N is assumed to be conserved while C is removed with decomposition, high C:N ratios are often interpreted as indicating relatively unaltered peat. However, Hyp yields indicate extensive turnover of plant N. Peat N was mostly plant-derived in the upper 50 cm of both cores, but declined to 30-60% in the catotelm. These results suggest that N from plant litter is rapidly utilized by microbes and incorporated into new forms. Thus despite high C:N ratios, these peats have undergone substantial alteration and decomposition. This demonstrates the organic N pool in peatlands is intensely recycled and is more dynamic than can be inferred by considering the C:N ratio alone.

  20. Effects of Burn Severity and Environmental Conditions on Post-Fire Regeneration in Siberian Larch Forest

    Directory of Open Access Journals (Sweden)

    Thuan Chu

    2017-03-01

    Full Text Available Post-fire forest regeneration is strongly influenced by abiotic and biotic heterogeneity in the pre- and post-fire environments, including fire regimes, species characteristics, landforms, hydrology, regional climate, and soil properties. Assessing these drivers is key to understanding the long-term effects of fire disturbances on forest succession. We evaluated multiple factors influencing patterns of variability in a post-fire boreal Larch (Larix sibirica forest in Siberia. A time-series of remote sensing images was analyzed to estimate post-fire recovery as a response variable across the burned area in 1996. Our results suggested that burn severity and water content were primary controllers of both Larch forest recruitment and green vegetation cover as defined by the forest recovery index (FRI and the fractional vegetation cover (FVC, respectively. We found a high rate of Larch forest recruitment in sites of moderate burn severity, while a more severe burn was the preferable condition for quick occupation by vegetation that included early seral communities of shrubs, grasses, conifers and broadleaf trees. Sites close to water and that received higher solar energy during the summer months showed a higher rate of both recovery types, defined by the FRI and FVC, dependent on burn severity. In addition to these factors, topographic variables and pre-fire condition were important predictors of post-fire forest patterns. These results have direct implications for the post-fire forest management in the Siberian boreal Larch region.

  1. Siberian Ibex (Capra sibirica Neonatal Kid Survival and Morphometric Measurements in Ikh Nart Nature Reserve, Mongolia

    Directory of Open Access Journals (Sweden)

    Baatargal Otgonbayar

    2017-05-01

    Full Text Available Understanding the factors infl uencing survival of ungulate neonates facilitates successful management programs, particularly as they relate to population dynamics and adaptive species management. However, kid survival of near threatened Siberian ibex (Capra sibirica remains poorly understood. During 2005-2013, we captured and collared 21 ibex kids in Ikh Nart Nature Reserve in southeastern Mongolia, to monitor their survival and cause-specifi c mortality. We found no diff erences in morphometric measurements between male and female kids, except body mass being males weighing more than females. A total of 11 mortalities were documented and predations by red foxes (n=5, Vulpes vulpes and grey wolf (n=1, Canis lupus was the leading cause of the mortalities. Known fate models indicate the monthly survival of kids best explained by body mass and fi rst month of life (April-May + weight. Monthly survival estimates ranged from 0.077 (95% CI = 0.60-0.88 in April-May to 0.97 (95% CI = 0.90-0.99 in June-March, with an annual survival rate of 0.45 (95% CI = 0.24-0.68. We found little support for the hypotheses that body mass or birth date infl uenced survival; however, our small sample size limited the power of the analyses. Overall, our results indicated that predation and other factors led to high kid mortality during the period shortly after birth

  2. Siberian Ibex ( Capra sibirica Home Ranges in Ikh Nart Nature Reserve, Mongolia: Preliminary Findings

    Directory of Open Access Journals (Sweden)

    Richard P. Reading

    2007-05-01

    Full Text Available Siberian ibex ( Capra sibirica remain poorly understood, as little is known about their ecology . W e began studying ibex in Ikh Nart Nature Reserve, Dornogobi Aimag, Mongolia to better understand the species’ ecological needs and threats. In this paper we report on home range and core range sizes. We captured 27 ibex and fi t them with radio telemetry collars using drive nets for adults and juveniles ( n = 22 and hand captures for neonatal kids ( n = 5 . W e collected 1,029 locations from September 2003 to February 2007. Throughout the study, 9 ibex with 40+ fi xe s used mean, annual home range sizes of 3,115.5 ± 504.2 ha using the Minimum Convex Polygon method. Home ranges calculated using the fi xe d kernel method were smaller: 475.9 ± 14.7 ha for 50% kernel and 1,808.0 ± 88.1 ha for 95% kernel. Ibex from different demographic groups (males vs. females and juveniles vs. adults used remarkably similar home and core ranges; we found no signifi ca nt differences among any demographic groups. Although not quantifi ed , ibex mostly restricted their activities to areas with steep cliffs and rocky outcrops and home ranges overlapped extensively.

  3. Exploitation of the UV Aerosol Index scattering angle dependence: Properties of Siberian smoke plumes

    Science.gov (United States)

    Penning de Vries, Marloes; Beirle, Steffen; Sihler, Holger; Wagner, Thomas

    2017-04-01

    The UV Aerosol Index (UVAI) is a simple measure of aerosols from satellite that is particularly sensitive to elevated layers of absorbing particles. It has been determined from a range of instruments including TOMS, GOME-2, and OMI, for almost four decades and will be continued in the upcoming Sentinel missions S5-precursor, S4, and S5. Despite its apparent simplicity, the interpretation of UVAI is not straightforward, as it depends on aerosol abundance, absorption, and altitude in a non-linear way. In addition, UVAI depends on the geometry of the measurement (viewing angle, solar zenith and relative azimuth angles), particularly if viewing angles exceed 45 degrees, as is the case for OMI and TROPOMI (on S5-precursor). The dependence on scattering angle complicates the interpretation and further processing (e.g., averaging) of UVAI. In certain favorable cases, however, independent information on aerosol altitude and absorption may become available. We present a detailed study of the scatter angle dependence using SCIATRAN radiative transfer calculations. The model results were compared to observations of an extensive Siberian smoke plume, of which parts reached 10-12 km altitude. Due to its large extent and the high latitude, OMI observed the complete plume in five consecutive orbits under a wide range of scattering angles. This allowed us to deduce aerosol characteristics (absorption and layer height) that were compared with collocated CALIOP lidar measurements.

  4. Large-Scale Plantlet Conversion and Ex Vitro Transplantation Efficiency of Siberian Ginseng by Bioreactor Culture

    Directory of Open Access Journals (Sweden)

    Jingli Yang

    2013-01-01

    Full Text Available To achieve large-scale low-cost ex vitro acclimatization of Siberian ginseng plants, heart- and torpedo-shaped secondary somatic embryos (SEs induced from germinated SEs on agar medium were collected and then inoculated to 10-l bubble column bioreactor, respectively. For plantlet conversion, inoculation of torpedo-shaped secondary SEs was more effective than heart-shaped SEs. TS2 (culture of torpedo-shaped SEs in a bioreactor with a 2-week subculture interval plantlets had a higher root number and leaf number and larger leaf area than did HS3 (culture of heart-shaped SEs in a bioreactor with a 3-week subculture interval and HS2 (culture of heart-shaped SEs in a bioreactor with a 2-week subculture interval plantlets. Of these converted plants, TS2 plantlets had higher survival rate (83.7% and growth characteristics after transplantation in a simple shed covered with a 50% sunshade net only for 6 months. TS2 plantlets also showed significantly lower H2O2 content and significantly increased superoxide dismutase (SOD, glutathione peroxidase (GPX, and glutathione transferase (GST expression levels as compared to HS2 plants when exposure to ex vitro conditions.

  5. Helminth fauna of the Siberian chipmunk, Tamias sibiricus Laxmann (Rodentia, Sciuridae) introduced in suburban French forests.

    Science.gov (United States)

    Pisanu, Benoît; Jerusalem, Christelle; Huchery, Cindy; Marmet, Julie; Chapuis, Jean-Louis

    2007-05-01

    The spread of an immigrant host species can be influenced both by its specific helminth parasites that come along with it and by newly acquired infections from native fauna. The Siberian chipmunk, Tamias sibiricus Laxmann (Rodentia, Sciuridae), a northeastern Eurasiatic ground nesting Sciurid, has been introduced in France for less than three decades. Thirty individuals were collected from three suburban forests in the Ile-de-France Region between 2002 and 2006. Two intestinal nematode species dominated the helminth fauna: Brevistriata skrjabini [Prevalence, P, 99% C.I., 87% (64-97%); mean intensity, M.I., 99% C.I., 43 (28-78)] and Aonchotheca annulosa [P, 47% (25-69%); M.I., 35 (3-157)]. B. skrjabini is a direct life cycle nematode species of North Eurasiatic origin, with a restricted spectrum of phylogenetically related suitable hosts. This result indicates that B. skrjabini successfully settled and spread with founder pet chipmunks maintained in captivity and released in natura. Chipmunks acquired A. annulosa, a nematode species with a large spectrum of phylogenetically unrelated suitable host species, from local Muroid rodent species with similar behavior, life-history traits and habitats. Quantitative studies are needed to evaluate the potential for both B. skrjabini and A. annulosa to impede the spread of Tamias and for B. skrjabini to favor chipmunk colonization through detrimental effects upon native co-inhabiting host species.

  6. Growing East Asia

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ It was a busy exchanging period of East Asia in recent days. From October 28 to 31, 2007 the fourth China-ASEAN Expo (CAEXPO) and the fourth China-ASEAN Business and Investment Summit (CABIS) were held concurrently in Nanning, capital city of Guangxi Province in China. In the Expo,China witnessed a turnout of over 33,000 trade visitors and over 180 investment cooperation projects with ASEAN.

  7. Near East & South Asia.

    Science.gov (United States)

    2007-11-02

    matriculate them into the Air College as pilot candidates, after they have obtained the general sec- ondary "scientific department" diploma. 52 NEAR EAST...Islamic training, Arabic, mathematics , physics, chemistry, biology, geology, history, geography, computer science, and English. Additional material will...This will help prepare the student for military life. The student will continue to advance gradually through the program until he matriculates as a

  8. An Index of East Asian Winter Monsoon Applied to the Description of China's Mainland Winter Temperature Changes

    Institute of Scientific and Technical Information of China (English)

    ZHU Yanfeng

    2008-01-01

    Using the NCEP/NCAR reanalysis data (Version 1.0) and the observation data of China from January 1951 to February 2007, a new index of East Asian winter monsoon circulation (IEAWM) was defined based on the comparison of previous different winter monsoon indices and circulation factors influencing the winter climate over China. Its relationships with winter temperature over China and large-scale circulation were analyzed. Results show that IEAWM can successfully describe the variation of China's mainland winter temperature and the East Asian winter monsoon (EAWM) system. This index reflects the integrated effect of the circulations over high and low latitudes and the thermal difference between the continent and the ocean. While in the previous studies, most monsoon indices only describe the single monsoon member. The IEAWM is a good indicator of the intensity of the EAWM. Positive values of IEAWM correspond to the strong EAWM, the stronger Siberian high and East Asian trough than normal, and the strengthening of the meridional shear of 500-hPa zonal wind between high and low latitudes over East Asia, and therefore, the southward cold advection becomes stronger and leads to the decrease in surface temperature over China; and vice versa. The IEAWM inter decadal change is obviously positive before the mid-1980s, but negative since the mid-1980s, in good agreement with the fact of the winter warming in China after 1985.

  9. Constituents and pharmacological effects of Eucommia and Siberian ginseng%杜仲和西伯利亚人参的化学成分及药理作用

    Institute of Scientific and Technical Information of China (English)

    DEYAMA Takeshi; NISHIBE Sansei; NAKAZAWA Yoshihisa

    2001-01-01

    The bark and leaves of Eucommia ulmoides Oiiv ( Eucommiaceae ) and "Siberian ginseng" ( Ezoukogi in Japanese) prepared from the root bark or stem bark of Eleutherococcus senticosus Maxim ( Acanthopanax senticosta Harms) have been used as tonic and anti-stress drug. The extracts of Eucommia showed anti-hypertensive, anti-complementary, anti-oxidative, and antigastric ulcer effects, and promoting collagen synthesis, accelating granuloma formation, and other pharmacological effects. The Siberian ginseng exhibited anti-fatigue,anti-stress, immuno-enhancing effect, CNS activity, and anti-depressive effect. By now, 40, 28, and 10 compounds have been isolated from Eucommia ulmoides bark, Eucommia ulmoides leaves, and Siberian ginseng,respectively, and their structures were elucidated. Their pharmacological activities were mainly due to lignans and iridoid glycosides.

  10. Variability of Growth Indicators and Generative Development of the Siberian and Korean Stone Pines at the Plantation in the «Green Zone» of Krasnoyarsk City

    Directory of Open Access Journals (Sweden)

    R. N. Matveeva

    2014-04-01

    Full Text Available The growth and seed production of Siberian and Korean stone pines at the age of 24–41 years in the «Izvestkovaya» plantation, located in the area of educational and experimental forest enterprise of the Siberian State Technological University (so-called «Green Zone» of Krasnoyarsk City were analyzed. It has been found that Korean stone pine (Pinus koraiensis Siebold & Zucc. is behind of Siberian stone pine (Pinus sibirica Du Tour in growth rate, the formation of cones and microstrobiles. Inter-and intraspecific variation in the formation of tree crown, cones and seeds size were significant, which allowed selection of individual trees with better reproduction characteristics.

  11. Drugs in East Germany.

    Science.gov (United States)

    Dressler, J; Müller, E

    1997-09-01

    Germany was divided into two parts after World War II. The closed border and a nonconvertible currency in the Eastern part were the factors that did not allow a drug market to develop. Alcohol and medicaments were used as substitute drugs. Since Germany was reunified 5 years ago, there are now the same conditions prevailing for the procurement and sale of drugs in East Germany as there are in the Western German states. This report describes the current state of drug traffic, especially in Saxony, under the new social conditions.

  12. East Asian welfare regime

    DEFF Research Database (Denmark)

    Abrahamson, Peter

    2017-01-01

    . Political science studies tend to conclude that the region has left the old legacies behind and are now welfare states comparable to European states including them either in the conservative type (e.g. Japan), the liberal type (e.g. Korea) or even as a tendency in the Nordic type (e.g. China), while studies......The paper asks if East Asian welfare regimes are still productivist and Confucian? And, have they developed public care policies? The literature is split on the first question but (mostly) confirmative on the second. Care has to a large, but insufficient extent, been rolled out in the region...

  13. Expression and phylogeny of candidate genes for sex differentiation in a primitive fish species, the Siberian sturgeon, Acipenser baerii.

    Science.gov (United States)

    Berbejillo, Julio; Martinez-Bengochea, Anabel; Bedo, Gabriela; Brunet, Frédéric; Volff, Jean-Nicolas; Vizziano-Cantonnet, Denise

    2012-08-01

    The molecular mechanisms underlying testis differentiation in basal actinopterygian fish remains poorly understood. The sex differentiation period was investigated in the Siberian sturgeon, Acipenser baerii, by expression profiling of Sertoli cell transcription factors (dmrt1, sox9) that control testis differentiation in vertebrates; Leydig cell factors (cyp17a1, star) affecting androgen production; the androgen receptor (ar); a growth factor controlling testis development (igf1); and a gene coding for a gonadotropin hormone (lh). Two genes were characterised for the first time in the Siberian sturgeon (dmrt1, cyp17a1), while the others came from public databases. Sturgeon gonad development is very slow, with a late sexual differentiation time during their juvenile stage, and are still immature at 3 years of age. Immature fish showed a sex-dimorphic pattern; all the genes studied displayed a higher expression level in male gonads. We took advantage of the presence of juvenile fish with pre- and post-differentiated gonads (16 and 18 months old) to characterise them at the molecular level. The post-differentiated fish displayed a sex dimorphism of gene expression in their gonads for all genes studied, with the exception of sox9. The trends in undifferentiated fish lead us to propose that sturgeons undergoing male differentiation express high levels of Sertoli cell factors (dmrt1, sox9) and of genes involved in the production and receptivity of androgens (cyp17a1, star and ar) together with lh. Expression profiles and phylogenetic studies suggest that these genes are potential regulators of testis development in the Siberian sturgeon.

  14. Effects of maturity stage and lactic acid bacteria on the fermentation quality and aerobic stability of Siberian wildrye silage.

    Science.gov (United States)

    Li, Ping; Bai, Shiqie; You, Minghong; Shen, Yixin

    2016-09-01

    It is difficult to make good quality of silage from alpine gramineous from the Qinghai Tibetan plateau. The effects of lactic acid bacteria (LAB) on the fermentation quality and aerobic stability of Siberian wildrye silage were studied in southeast of the Qinghai Tibetan plateau. Siberian wildrye materials were freshly cut at the sprouting stage, flowering stage, and milky stage. Silage was prepared by using a small-scale silage fermentation system (bag silos). Lactobacillus plantarum (LP, 5 × 10(8) cfu/kg FM), Lactobacillus buchneri (LB, 5 × 10(8) cfu/kg FM) and their mixture (LP+LB, 5 × 10(8) cfu/kg FM) as silage additives were separately added to ensiled forages, and no additive served as control (CK). These bag silos were kept at room temperature (qualities were analyzed after 60 days of ensiling. The number of indigenous LAB on fresh materials was less than that of yeasts and molds, and LAB species showed specification adapted to low temperature. LAB inoculated silages had lower (P acid content compared with control silage. Silage treated with LB had higher contents of acetic acid, propionic acid, WSC and CP. However, the aerobic stability of silages inoculated with LAB did not differ significantly between stages (P > 0.05). When fermentation characteristics, chemical composition, and aerobic stability were considered, treatment with L. plantarum resulted in high quality of Siberian wildrye silage harvested at the flowering stage in the alpine region.

  15. Twice daily melatonin peaks in Siberian but not Syrian hamsters under 24 h light:dark:light:dark cycles.

    Science.gov (United States)

    Raiewski, Evan E; Elliott, Jeffrey A; Evans, Jennifer A; Glickman, Gena L; Gorman, Michael R

    2012-11-01

    The daily pattern of blood-borne melatonin varies seasonally under the control of a multi-oscillator circadian pacemaker. Here we examine patterns of melatonin secretion and locomotor activity in Siberian and Syrian hamsters entrained to bimodal LDLD8:4:8:4 and LD20:4 lighting schedules that facilitate novel temporal arrangements of component circadian oscillators. Under LDLD, both species robustly bifurcated wheel-running activity in distinct day scotophase (DS) and night scotophase (NS) bouts. Siberian hamsters displayed significant melatonin increases during each scotophase in LDLD, and in the single daily scotophase of LD20:4. The bimodal melatonin secretion pattern persisted in acutely extended 16 h scotophases. Syrian hamsters, in contrast, showed no significant increases in plasma melatonin during either scotophase of LDLD8:4:8:4 or in LD20:4. In this species, detectable levels were observed only when the DS of LDLD was acutely extended to yield 16 h of darkness. Established species differences in the phase lag of nocturnal melatonin secretion relative to activity onset may underlie the above contrast: In non-bifurcated entrainment to 24 h LD cycles, Siberian hamsters show increased melatonin secretion within ≈ 2 h after activity onset, whereas in Syrian hamsters, detectable melatonin secretion phase lags activity onset and the L/D transition by at least 4 h. The present results provide new evidence indicating multi-oscillator regulation of the waveform of melatonin secretion, specifically, the circadian control of the onset, offset and duration of nocturnal secretion.

  16. Hypothalamic ventricular ependymal thyroid hormone deiodinases are an important element of circannual timing in the Siberian hamster (Phodopus sungorus).

    Science.gov (United States)

    Herwig, Annika; de Vries, Emmely M; Bolborea, Matei; Wilson, Dana; Mercer, Julian G; Ebling, Francis J P; Morgan, Peter J; Barrett, Perry

    2013-01-01

    Exposure to short days (SD) induces profound changes in the physiology and behaviour of Siberian hamsters, including gonadal regression and up to 30% loss in body weight. In a continuous SD environment after approximately 20 weeks, Siberian hamsters spontaneously revert to a long day (LD) phenotype, a phenomenon referred to as the photorefractory response. Previously we have identified a number of genes that are regulated by short photoperiod in the neuropil and ventricular ependymal (VE) cells of the hypothalamus, although their importance and contribution to photoperiod induced physiology is unclear. In this refractory model we hypothesised that the return to LD physiology involves reversal of SD expression levels of key hypothalamic genes to their LD values and thereby implicate genes required for LD physiology. Male Siberian hamsters were kept in either LD or SD for up to 39 weeks during which time SD hamster body weight decreased before increasing, after more than 20 weeks, back to LD values. Brain tissue was collected between 14 and 39 weeks for in situ hybridization to determine hypothalamic gene expression. In VE cells lining the third ventricle, expression of nestin, vimentin, Crbp1 and Gpr50 were down-regulated at 18 weeks in SD photoperiod, but expression was not restored to the LD level in photorefractory hamsters. Dio2, Mct8 and Tsh-r expression were altered by SD photoperiod and were fully restored, or even exceeded values found in LD hamsters in the refractory state. In hypothalamic nuclei, expression of Srif and Mc3r mRNAs was altered at 18 weeks in SD, but were similar to LD expression values in photorefractory hamsters. We conclude that in refractory hamsters not all VE cell functions are required to establish LD physiology. However, thyroid hormone signalling from ependymal cells and reversal of neuronal gene expression appear to be essential for the SD refractory response.

  17. Hypothalamic ventricular ependymal thyroid hormone deiodinases are an important element of circannual timing in the Siberian hamster (Phodopus sungorus.

    Directory of Open Access Journals (Sweden)

    Annika Herwig

    Full Text Available Exposure to short days (SD induces profound changes in the physiology and behaviour of Siberian hamsters, including gonadal regression and up to 30% loss in body weight. In a continuous SD environment after approximately 20 weeks, Siberian hamsters spontaneously revert to a long day (LD phenotype, a phenomenon referred to as the photorefractory response. Previously we have identified a number of genes that are regulated by short photoperiod in the neuropil and ventricular ependymal (VE cells of the hypothalamus, although their importance and contribution to photoperiod induced physiology is unclear. In this refractory model we hypothesised that the return to LD physiology involves reversal of SD expression levels of key hypothalamic genes to their LD values and thereby implicate genes required for LD physiology. Male Siberian hamsters were kept in either LD or SD for up to 39 weeks during which time SD hamster body weight decreased before increasing, after more than 20 weeks, back to LD values. Brain tissue was collected between 14 and 39 weeks for in situ hybridization to determine hypothalamic gene expression. In VE cells lining the third ventricle, expression of nestin, vimentin, Crbp1 and Gpr50 were down-regulated at 18 weeks in SD photoperiod, but expression was not restored to the LD level in photorefractory hamsters. Dio2, Mct8 and Tsh-r expression were altered by SD photoperiod and were fully restored, or even exceeded values found in LD hamsters in the refractory state. In hypothalamic nuclei, expression of Srif and Mc3r mRNAs was altered at 18 weeks in SD, but were similar to LD expression values in photorefractory hamsters. We conclude that in refractory hamsters not all VE cell functions are required to establish LD physiology. However, thyroid hormone signalling from ependymal cells and reversal of neuronal gene expression appear to be essential for the SD refractory response.

  18. Benzene and toluene in the surface air of northern Eurasia from TROICA-12 campaign along the Trans-Siberian Railway

    Science.gov (United States)

    Skorokhod, Andrey I.; Berezina, Elena V.; Moiseenko, Konstantin B.; Elansky, Nikolay F.; Belikov, Igor B.

    2017-05-01

    Volatile organic compounds (VOCs) were measured by proton transfer reaction mass spectrometry (PTR-MS) on a mobile laboratory in a transcontinental TROICA-12 (21 July-4 August 2008) campaign along the Trans-Siberian Railway from Moscow to Vladivostok. Surface concentrations of benzene (C6H6) and toluene (C7H8) along with non-methane hydrocarbons (NMHCs), CO, O3, SO2, NO, NO2 and meteorology are analyzed in this study to identify the main sources of benzene and toluene along the Trans-Siberian Railway. The most measurements in the TROICA-12 campaign were conducted under low-wind/stagnant conditions in moderately ( ˜ 78 % of measurements) to weakly polluted ( ˜ 20 % of measurements) air directly affected by regional anthropogenic sources adjacent to the railway. Only 2 % of measurements were identified as characteristic of highly polluted urban atmosphere. Maximum values of benzene and toluene during the campaign reached 36.5 and 45.6 ppb, respectively, which is significantly less than their short-term exposure limits (94 and 159 ppb for benzene and toluene, respectively). About 90 % of benzene and 65 % of toluene content is attributed to motor vehicle transport and 10 and 20 %, respectively, provided by the other local- and regional-scale sources. The highest average concentrations of benzene and toluene are measured in the industrial regions of the European Russia (up to 0.3 and 0.4 ppb for benzene and toluene, respectively) and south Siberia (up to 0.2 and 0.4 ppb for benzene and toluene, respectively). Total contribution of benzene and toluene to photochemical ozone production along the Trans-Siberian Railway is about 16 % compared to the most abundant organic VOC - isoprene. This contribution, however, is found to be substantially higher (up to 60-70 %) in urbanized areas along the railway, suggesting an important role of anthropogenic pollutant sources in regional ozone photochemistry and air quality.

  19. Hypothalamic over-expression of VGF in the Siberian hamster increases energy expenditure and reduces body weight gain

    Science.gov (United States)

    Brameld, John M.; Hill, Phil; Cocco, Cristina; Noli, Barbara; Ferri, Gian-Luca; Barrett, Perry; Ebling, Francis J. P.; Jethwa, Preeti H.

    2017-01-01

    VGF (non-acronymic) was first highlighted to have a role in energy homeostasis through experiments involving dietary manipulation in mice. Fasting increased VGF mRNA in the Arc and levels were subsequently reduced upon refeeding. This anabolic role for VGF was supported by observations in a VGF null (VGF-/-) mouse and in the diet-induced and gold-thioglucose obese mice. However, this anabolic role for VGF has not been supported by a number of subsequent studies investigating the physiological effects of VGF-derived peptides. Intracerebroventricular (ICV) infusion of TLQP-21 increased resting energy expenditure and rectal temperature in mice and protected against diet-induced obesity. Similarly, ICV infusion of TLQP-21 into Siberian hamsters significantly reduced body weight, but this was due to a decrease in food intake, with no effect on energy expenditure. Subsequently NERP-2 was shown to increase food intake in rats via the orexin system, suggesting opposing roles for these VGF-derived peptides. Thus to further elucidate the role of hypothalamic VGF in the regulation of energy homeostasis we utilised a recombinant adeno-associated viral vector to over-express VGF in adult male Siberian hamsters, thus avoiding any developmental effects or associated functional compensation. Initially, hypothalamic over-expression of VGF in adult Siberian hamsters produced no effect on metabolic parameters, but by 12 weeks post-infusion hamsters had increased oxygen consumption and a tendency to increased carbon dioxide production; this attenuated body weight gain, reduced interscapular white adipose tissue and resulted in a compensatory increase in food intake. These observed changes in energy expenditure and food intake were associated with an increase in the hypothalamic contents of the VGF-derived peptides AQEE, TLQP and NERP-2. The complex phenotype of the VGF-/- mice is a likely consequence of global ablation of the gene and its derived peptides during development, as well

  20. Anomalies of Siberian High Intensity and Their Precursors in Climatic Models Output

    Science.gov (United States)

    Martynova, Yuliya; Krupchatnikov, Vladimir

    2016-04-01

    The Siberian High (SH) is a powerful pressure system that determines the weather regime during the wintertime for the huge part of Asia [Sazonov B.I., 1991]. Particularly, SH regulates an intensity and duration of frosts in Siberia. Moreover, this pressure system has a strong connection with another atmospheric centers of action of the Northern Hemisphere such as Arctic High, Icelandic Low, the Azores High [Morozova S.V., 2013]. SH variation is closely related to atmospheric dynamics processes and air temperature variations between surface and middle troposphere. The maintaining of SH mainly depends on downward through the troposphere airflow which variation is strongly affected by the Arctic oscillation (AO). Positive (negative) AO phase causes the remarkably weakening (strengthening) of the downward airflow that has strong effect on the SH behavior [Gong G. et al., 2002; Krupchatnikov V. N. et al., 2009; Martynova Yu.V. and V.N. Krupchatnikov, 2010]. SH is highly exposed to global climate change that increases standard deviation of SH intensity [Fei L.I. and G. A. O. Yong-Qi, 2015]. The changes of SH characteristics result from not only direct climate change effect (such as global temperature rise) but also feedback effect of another climate system parameters variation. Thus, these parameters can serve as precursors of the extremely SH intensity. It's important to remember that the changes of the just one component of this High-Low interaction system could affect whole system. This study is devoted to determination of the precursors of the anomaly SH behavior and estimation of changes of the determined connection in the climate change conditions. The research was provided on a base of climate system models and reanalysis data. Acknowledgements This work is partially supported by SB RAS project VIII.80.2.1, RFBR grants 14-05-00502, 16-35-00301, 16-05-00558. References Fei L.I. and G. A. O. Yong-Qi The Project Siberian High in CMIP5 Models // Atmospheric and

  1. Cryosols of the Northeast Siberian Lena River Delta and its hinterland - genesis and diversity

    Science.gov (United States)

    Zubrzycki, Sebastian; Kutzbach, Lars; Pfeiffer, Eva-Maria

    2016-04-01

    The North-Siberian Lena River Delta (LRD) is the largest Arctic delta and an important interface between the Arctic Ocean in the North and the large Siberian land masses in the South. LRD consists not only of Holocene deltaic sediment deposits as a river terrace and the modern active floodplains but also of remnants of the former Pleistocene mainland including large islands of ice-complex sediments and the Arga-Muora-Sise Island, which is composed of pure sand sediments of still debated origin. The highly diverse landscape structure of LRD is reflected by a great variety of permafrost-affected soils (cryosols). This study aims at describing this great cryosol diversity and at analysing the dominant soil-forming processes in this comparatively scarcely studied soil region. The soil development in the investigated continuous permafrost region is limited by the short thawing period of around three months (June to September) and takes place in the shallow (below 1 m) seasonally thawed active layer. The geological parent material plays an important role for the development of soils in the LRD region. The distribution of the various soil types closely follows the pattern of the geomorphic units characterised by differing sedimentation conditions. The properties and genesis of the soils on the Holocene river terrace and the modern floodplains are strongly affected by the enormous amounts of fluvial sediments (about 12 x 106 tons per year) brought by the Lena River into its delta. The fluvial sedimentation together with the also pronounced aeolian sedimentation results in a fast vertical growth of soils. The upward rise of the soil surface leads to an upward movement of the permafrost table resulting in fast incorporation of soil material formed in the supra-permafrost zone into the permafrost. Due to the morphodynamics of ice-wedge polygons and resulting formation of patterned ground with elevated rims and depressed and water-saturated centres, the Holocene river terrace

  2. Monitoring Western Siberian Wetlands from satellite observations and in situ observations

    Science.gov (United States)

    Zakharova, E. A.; Kouraev, A. V.; Kolmakova, M. V.; Bazanov, V. A.; Skugarev, A. A.; Berezin, A. E.; Kirpotin, S. N.; Zemtsov, V. A.; Mognard, N. M.

    2009-04-01

    Western Siberia is a large region with mostly flat relief. Most of its territory comprises the watershed of the Ob' river, and much smaller part in the north - watersheds of Nadym, Pur and Taz rivers. Flat relief significantly affects the hydrographical network, creating a multitude of interconnected natural objects - large and small rivers streams, large floodplains, lakes, bogs etc. The region is also abundant with lakes, mainly small ones with surface area less than 1 km2 and depths of 2-5 m. Flooded areas and bogs also act as a buffer zone, providing a dampening "sponge" effect on the water redistribution within the river system. Large area covered by rivers and wetlands results in high rate of evaporation compared to any other large boreal watershed. Contrasting processes are occurring in the Southern and Northern parts of the Western Siberian Plain. In the south, bogs are expanding in the taiga zone and there is progressive swamping which leads to forest death. These bogs act as a carbon sink due to carbon sequestration in their peat layers. Among the bogs of this part of Western Siberia there is the Great Vasiugan Bog - world's largest peatland with a total area of 6.78 million hectares. Bogs of Vasyugan have appeared about 10 000 years ago and since then are constantly growing. 75% of the actual surface of the Great Vasyugan Bog have appeared during the last 500 years. The situation in the northern part (affected by permafrost) is different. The bogs there are reducing their surface and the forest-tundra regions are being subjected to thermokarst activity and colonisation of bogs by trees. Two contrast processes are observed here - a) increase of lake surface due to melting of lakes' coasts, and b) decrease of surface area or disappearance of lakes due to water drain downstream the hydrological network. We combine in situ observations with satellite remote sensing to monitor hydrological regime of the Western Siberian wetlands. Radar altimetry (TOPEX

  3. Development of a high resolution modeling tool for prediction of waterflows through complex mires: Example of the Mukhrino bog complex in West Siberian middle Taiga Zone

    Science.gov (United States)

    Zarov, Evgeny A.; Schmitz, Oliver; Bleuten, Wladimir

    2015-04-01

    Water flow through peat bogs differ substantially from mineral soil landscapes. Permeability of the peatlayers decrease dramatically with depth within the permanently watersaturated peat layers (Catotelm), whereas the 10-60 cm thick superficial layer (Acrotelm) has a very high conductivity. Water flows predominantly in this acrotelm layer where an open structure of stems of mosses and few plants hardly limit water flow. By omitting this superficial flow infrastructures in many places block the waterflow. Moreover, the different bog types within a complex bog have different hydrological conductivities. Without considering the typical water-flow of bogs the construction of roads and platforms for oil and gas production threatens downhill mire ecosystems by partly drainage. The objective of our study was to develop a modeling tool which can be used to predict quantitatively spatially distributed water-flow of a bog complex. A part of the extensive bog complex "Mukhrino bog complex" located at the left bank of Irtysh river near the West Siberian town Khanty-Mansiysk' was chosen as modeling area. Water discharge from this bog catchment occurs by "waterfalls" at the East margin where a scarp with ca. 8 m elevation difference has been developed by backward erosion into the bog by the Mukhrino river. From field observations it was proven that no discharge of groundwater occurred at the margin of the bog catchment area. We used PCRaster-MODFLOW as modeling environment. The model area size was 3.8 km2, cell size 5 m and the model included 3 Acrotelm layers and 3 Catotelm layers. Thickness of Acrotelm and Catotelm have been measured by coring in transects. Input data of rain, snow have been recorded in the study area. Evapotranspiration was measured with small lysimeters and crop factors for different land unit types (open water, raised bog, patterned bog, poor fens) were elaborated by water balance modeling (1-D). Land unit types have been mapped by supervised classification

  4. Phenotypic differences in reentrainment behavior and sensitivity to nighttime light pulses in siberian hamsters.

    Science.gov (United States)

    Ruby, Norman F; Barakat, Monique T; Heller, H Craig

    2004-12-01

    Spontaneous reentrainment to phase shifts of the photocycle is a fundamental property of all circadian systems. Siberian hamsters are, however, unique in this regard because most fail to reentrain when the LD cycle (16-h light/day) is phase delayed by 5 h. In the present study, the authors compared reentrainment responses in hamsters from 2 colonies. One colony descended from animals trapped in the wild more than 30 years ago (designated "nonentrainers"), and the other colony was outbred as recently as 13 years ago (designated "entrainers"). As reported previously, only 10% of hamsters from the nonentrainer colony reentrained to a 5-h phase delay of the LD cycle. By contrast, 75% of animals from the entrainer colony reentrained to the phase shift. Another goal of this study was to test the hypothesis that failure to reentrain was a consequence of light exposure during the middle of the night on the day of the 5-h phase delay. This hypothesis was tested by exposing animals to 2 h of light during the early, middle, or late part of the night and then subjecting them on the next day to a 3-h phase delay of the photocycle, which is a phase shift to which all hamsters normally reentrain. All animals from both colonies reentrained when light pulses occurred early in the night, but more animals from the entrainer colony, compared to the nonentrainer colony, reentrained when the light pulse occurred in the middle or late part of the night. The phenotypic variation in reentrainment responses is similar to the variation in photoperiodic responsiveness previously reported for these 2 colonies. Phenotypic variation in both traits is due to underlying differences in circadian organization and suggests a common genetic basis for reentrainment responses and photoperiodic responsiveness.

  5. Dim light at night disrupts the short-day response in Siberian hamsters.

    Science.gov (United States)

    Ikeno, Tomoko; Weil, Zachary M; Nelson, Randy J

    2014-02-01

    Photoperiodic regulation of physiology, morphology, and behavior is crucial for many animals to survive seasonally variable conditions unfavorable for reproduction and survival. The photoperiodic response in mammals is mediated by nocturnal secretion of melatonin under the control of a circadian clock. However, artificial light at night caused by recent urbanization may disrupt the circadian clock, as well as the photoperiodic response by blunting melatonin secretion. Here we examined the effect of dim light at night (dLAN) (5lux of light during the dark phase) on locomotor activity rhythms and short-day regulation of reproduction, body mass, pelage properties, and immune responses of male Siberian hamsters. Short-day animals reduced gonadal and body mass, decreased spermatid nuclei and sperm numbers, molted to a whiter pelage, and increased pelage density compared to long-day animals. However, animals that experienced short days with dLAN did not show these short-day responses. Moreover, short-day specific immune responses were altered in dLAN conditions. The nocturnal activity pattern was blunted in dLAN hamsters, consistent with the observation that dLAN changed expression of the circadian clock gene, Period1. In addition, we demonstrated that expression levels of genes implicated in the photoperiodic response, Mel-1a melatonin receptor, Eyes absent 3, thyroid stimulating hormone receptor, gonadotropin-releasing hormone, and gonadotropin-inhibitory hormone, were higher in dLAN animals than those in short-day animals. These results suggest that dLAN disturbs the circadian clock function and affects the molecular mechanisms of the photoperiodic response.

  6. Light at night alters daily patterns of cortisol and clock proteins in female Siberian hamsters.

    Science.gov (United States)

    Bedrosian, T A; Galan, A; Vaughn, C A; Weil, Z M; Nelson, R J

    2013-06-01

    Humans and other organisms have adapted to a 24-h solar cycle in response to life on Earth. The rotation of the planet on its axis and its revolution around the sun cause predictable daily and seasonal patterns in day length. To successfully anticipate and adapt to these patterns in the environment, a variety of biological processes oscillate with a daily rhythm of approximately 24 h in length. These rhythms arise from hierarchally-coupled cellular clocks generated by positive and negative transcription factors of core circadian clock gene expression. From these endogenous cellular clocks, overt rhythms in activity and patterns in hormone secretion and other homeostatic processes emerge. These circadian rhythms in physiology and behaviour can be organised by a variety of cues, although they are most potently entrained by light. In recent history, there has been a major change from naturally-occurring light cycles set by the sun, to artificial and sometimes erratic light cycles determined by the use of electric lighting. Virtually every individual living in an industrialised country experiences light at night (LAN) but, despite its prevalence, the biological effects of such unnatural lighting have not been fully considered. Using female Siberian hamsters (Phodopus sungorus), we investigated the effects of chronic nightly exposure to dim light on daily rhythms in locomotor activity, serum cortisol concentrations and brain expression of circadian clock proteins (i.e. PER1, PER2, BMAL1). Although locomotor activity remained entrained to the light cycle, the diurnal fluctuation of cortisol concentrations was blunted and the expression patterns of clock proteins in the suprachiasmatic nucleus and hippocampus were altered. These results demonstrate that chronic exposure to dim LAN can dramatically affect fundamental cellular function and emergent physiology.

  7. Adaptation to short photoperiods augments circadian food anticipatory activity in Siberian hamsters.

    Science.gov (United States)

    Bradley, Sean P; Prendergast, Brian J

    2014-06-01

    This article is part of a Special Issue "Energy Balance". Both the light-dark cycle and the timing of food intake can entrain circadian rhythms. Entrainment to food is mediated by a food entrainable circadian oscillator (FEO) that is formally and mechanistically separable from the hypothalamic light-entrainable oscillator. This experiment examined whether seasonal changes in day length affect the function of the FEO in male Siberian hamsters (Phodopus sungorus). Hamsters housed in long (LD; 15 h light/day) or short (SD; 9h light/day) photoperiods were subjected to a timed-feeding schedule for 10 days, during which food was available only during a 5h interval of the light phase. Running wheel activity occurring within a 3h window immediately prior to actual or anticipated food delivery was operationally-defined as food anticipatory activity (FAA). After the timed-feeding interval, hamsters were fed ad libitum, and FAA was assessed 2 and 7 days later via probe trials of total food deprivation. During timed-feeding, all hamsters exhibited increases FAA, but FAA emerged more rapidly in SD; in probe trials, FAA was greater in magnitude and persistence in SD. Gonadectomy in LD did not induce the SD-like FAA phenotype, indicating that withdrawal of gonadal hormones is not sufficient to mediate the effects of photoperiod on FAA. Entrainment of the circadian system to light markedly affects the functional output of the FEO via gonadal hormone-independent mechanisms. Rapid emergence and persistent expression of FAA in SD may reflect a seasonal adaptation that directs behavior toward sources of nutrition with high temporal precision at times of year when food is scarce.

  8. Long-term Impacts of Fire on Permafrost Vulnerability and C loss in Siberian Larch Forests

    Science.gov (United States)

    Egan, J. E.; Natali, S.; Alexander, H. D.; Loranty, M. M.; Spawn, S.; Risk, D. A.

    2015-12-01

    In Boreal forests, which contain large stocks of terrestrial carbon (C), fires have been increasing and are expected to continue to do so as the climate becomes warmer and dryer. Here we studied the indirect, long-term effects of fire on ecosystem C cycling via changes in stand density, organic layer and thaw depth in, in Siberian larch (Larix cajanderi) forests, underlain by continuous permafrost, near Chersky, Russia. Understory net ecosystem exchange (NEE), ecosystem respiration (Reco) and thaw depth were measured for 3 growing seasons from density plots (related to fire severity) found within a 75-yr burn scar and from experimental burn plots. In 2015, Reco was partitioned, using a dual-isotope approach, to determine how fire severity alters the contribution of autotrophic and heterotrophic respiration. Reco gas samples were collected from static chambers, and at the density gradient we also collected carbon dioxide (CO2) from Reco sources (organic and mineral layer soils, above and belowground vegetation). We expect that differences in thaw depth, vegetation and organic layer related to stand density, will impact the contribution of old C sources to Reco. In the experimental burn plots, the severity of the burn and thaw depth were positively correlated, and promoted loss of old C. Following the fires in 2012, higher intensity burns decreased Reco, but 3 years later, Reco was similar across burn treatments. In the 75-yr burn, stand density significantly impacted both thaw depth and understory CO2 exchange, where higher density stands, had lower thaw depths, higher understory NEE, and C loss from young C sources that have assimilated since the fire. Decades after fire, permafrost vulnerability and C accumulation are driven by stand density, where higher-density stands have higher rates of NEE, but C loss from relatively young C.

  9. Investigating carbon dynamics in Siberian peat bogs using molecular-level analyses

    Science.gov (United States)

    Kaiser, K.; Benner, R. H.

    2013-12-01

    Total hydrolysable carbohydrates, and lignin and cutin acid compounds were analyzed in peat cores collected 56.8 N (SIB04), 58.4 N (SIB06), 63.8 N (G137) and 66.5 N (E113) in the Western Siberian Lowland to investigate vegetation, chemical compositions and the stage of decomposition. Sphagnum mosses dominated peatland vegetation in all four cores. High-resolution molecular analyses revealed rapid vegetation changes on timescales of 50-200 years in the southern cores Sib4 and Sib6. Syringyl and vanillyl (S/V) ratios and cutin acids indicated these vegetation changes were due to varying inputs of angiosperm and gymnosperm and root material. In the G137 and E113 cores lichens briefly replaced sphagnum mosses and vascular plants. Molecular decomposition indicators used in this study tracked the decomposition of different organic constituents of peat organic matter. The carbohydrate decomposition index was sensitive to the polysaccharide component of all peat-forming plants, whereas acid/aldehyde ratios of S and V phenols (Ac/AlS,V) followed the lignin component of vascular plants. Low carbohydrate decomposition indices in peat layers corresponded well with elevated (Ad/Al)S,V ratios. This suggested both classes of biochemicals were simultaneously decomposed, and decomposition processes were associated with extensive total mass loss in these ombrotrophic systems. Selective decomposition or transformation of lignin was observed in the permafrost-influenced northern cores G137 and E113. Both cores exhibited the highest (Ad/Al)S,V ratios, almost four-fold higher than measured in peat-forming plants. The extent of decomposition in the four peat cores did not uniformly increase with age, but showed episodic extensive decomposition events. Variable decomposition events independent of climatic conditions and vegetation shifts highlight the complexity of peatland dynamics.

  10. Geochemistry of selected oils and rocks from the central portion of the West Siberian basin, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Peters, K.E.; Huizinga, B.J. (Chevron Overseas Petroleum Inc., San Ramon, CA (United States)); Kontorovich, A.Eh.; Andrusevich, V.E. (Inst. of Geology, Novosibirsk (Russian Federation)); Moldowan, J.M. (Chevron Petroleum Technology Co., Richmond, CA (United States)); Demaison, G.J. (Petroscience Inc., Walnut Creek, CA (United States)); Stasova, O.F. (NPO SIBGEO, Novosibirsk (Russian Federation))

    1993-05-01

    Six analyzed oils, produced from Middle jurassic to Upper Cretaceous strata in the Middle Ob region of the West Siberian basin, show biomarker and stable carbon isotope compositions indicating an origin from the Upper Jurassic Bazhenov Formation. The chemical compositions of these oils are representative of more than 85% of the reserves in West Siberia (Kontorovich et al., 1975). Bazhenov-sourced oil in Cenomanian strata in the Van-Egan field underwent biodegradation in the reservoir, resulting in a low API gravity, an altered homohopane distribution, and the appearance of 25-norhopanes without alteration of the steranes. High API gravity oil from the Salym field has surpassed the peak of the oil window, consistent with abnormally high temperatures and pressures in the Bazhenov source rock from which it is produced. The remaining oils are very similar, including samples from Valanginian and Bathonian-Callovian intervals in a sequence of stacked reservoirs in the Fedorov field. Bazhenov rock samples from the study area contain abundant oil-prone, marine organic matter preserved under anoxic conditions. While the Upper Jurassic Vasyugan Formation shows lower oil-regenerative potential than the Bazhenov Formation, it cannot be excluded as a source rock because insufficient sample was available for biomarker analysis. Core from the Lower to Middle Jurassic Tyumen Formation in the YemYegov 15 well was compared with the oils because it is thermally mature and shows TOC and HI values, indicating slightly more favorable oil-generative characteristics than the average for the formation (2.75 wt. % for 270 samples; 95 mg HC/g TOC for 25 samples). The core contains terrigenous, gas-prone organic matter that shows no relationship with the analyzed oils. 59 refs., 15 figs., 8 tabs.

  11. Mortality of Siberian polecats and black-footed ferrets released onto prairie dog colonies

    Science.gov (United States)

    Biggins, D.E.; Miller, B.J.; Hanebury, L.R.; Powell, R.A.

    2011-01-01

    Black-footed ferrets (Mustela nigripes) likely were extirpated from the wild in 19851986, and their repatriation depends on captive breeding and reintroduction. Postrelease survival of animals can be affected by behavioral changes induced by captivity. We released neutered Siberian polecats (M. eversmanii), close relatives of ferrets, in 19891990 on black-tailed prairie dog (Cynomys ludovicianus) colonies in Colorado and Wyoming initially to test rearing and reintroduction techniques. Captive-born polecats were reared in cages or cages plus outdoor pens, released from elevated cages or into burrows, and supplementally fed or not fed. We also translocated wild-born polecats from China in 1990 and released captive-born, cage-reared black-footed ferrets in 1991, the 1st such reintroduction of black-footed ferrets. We documented mortality for 55 of 92 radiotagged animals in these studies, mostly due to predation (46 cases). Coyotes (Canis latrans) killed 31 ferrets and polecats. Supplementally fed polecats survived longer than nonprovisioned polecats. With a model based on deaths per distance moved, survival was highest for wild-born polecats, followed by pen-experienced, then cage-reared groups. Indexes of abundance (from spotlight surveys) for several predators were correlated with mortality rates of polecats and ferrets due to those predators. Released black-footed ferrets had lower survival rates than their ancestral population in Wyoming, and lower survival than wild-born and translocated polecats, emphasizing the influence of captivity. Captive-born polecats lost body mass more rapidly postrelease than did captive-born ferrets. Differences in hunting efficiency and prey selection provide further evidence that these polecats and ferrets are not ecological equivalents in the strict sense. ?? 2011 American Society of Mammalogists.

  12. Thermal Properties of West Siberian Sediments in Application to Basin and Petroleum Systems Modeling

    Science.gov (United States)

    Romushkevich, Raisa; Popov, Evgeny; Popov, Yury; Chekhonin, Evgeny; Myasnikov, Artem; Kazak, Andrey; Belenkaya, Irina; Zagranovskaya, Dzhuliya

    2016-04-01

    Quality of heat flow and rock thermal property data is the crucial question in basin and petroleum system modeling. A number of significant deviations in thermal conductivity values were observed during our integral geothermal study of West Siberian platform reporting that the corrections should be carried out in basin models. The experimental data including thermal anisotropy and heterogeneity measurements were obtained along of more than 15 000 core samples and about 4 500 core plugs. The measurements were performed in 1993-2015 with the optical scanning technique within the Continental Super-Deep Drilling Program (Russia) for scientific super-deep well Tyumenskaya SG-6, parametric super-deep well Yen-Yakhinskaya, and deep well Yarudeyskaya-38 as well as for 13 oil and gas fields in the West Siberia. Variations of the thermal conductivity tensor components in parallel and perpendicular direction to the layer stratification (assessed for 2D anisotropy model of the rock studied), volumetric heat capacity and thermal anisotropy coefficient values and average values of the thermal properties were the subject of statistical analysis for the uppermost deposits aged by: T3-J2 (200-165 Ma); J2-J3 (165-150 Ma); J3 (150-145 Ma); K1 (145-136 Ma); K1 (136-125 Ma); K1-K2 (125-94 Ma); K2-Pg+Ng+Q (94-0 Ma). Uncertainties caused by deviations of thermal conductivity data from its average values were found to be as high as 45 % leading to unexpected errors in the basin heat flow determinations. Also, the essential spatial-temporal variations in the thermal rock properties in the study area is proposed to be taken into account in thermo-hydrodynamic modeling of hydrocarbon recovery with thermal methods. The research work was done with financial support of the Russian Ministry of Education and Science (unique identification number RFMEFI58114X0008).

  13. Archaeological Monuments of the Siberian Khanates: Search of the Markers of the Statehood.

    Directory of Open Access Journals (Sweden)

    S.F. Tataurov

    2017-06-01

    Full Text Available Research objectives: To identify several sets of archaeological materials, which allow to unite all the Turkic-Tatar population of the forest-steppe zone of Western Siberia not only on the basis of socio-economic relations, but also on the principles of the existence of state entities. Research materials: Archaeological material (ceramics, weapons and funeral rite of warriors, ring-seals and attributes of supreme authority – helmets and tamgas. Results and novelty of the research: At present, the Turkic-Tatar state formations remain one of the most poorly studied issues in the medieval history of Western Siberia. An unformed base of archaeological sources could be added to a small amount of written documents. As a result, academic community is not able to make a full description of specific khanates – of their boundaries, administrative division and management, the level of development of state institutions, etc. Moreover, we do not have a chronological scale of cultural layers of any archaeological complex of this time including the capitals of khanates – Chimgi-Tura and Isker. Ordinary settlements and cemeteries remain with indefinite characteristics (cultural phenomena, which could allow to combine all these complexes into one whole, to become markers of the Siberian statehood. The author proposes to identify several sets of archaeological materials, which allow to unite all the Turkic-Tatar population of the forest-steppe zone of Western Siberia not only on the basis of socio-economic relations, but also on the principles of the existence of state entities. The author presents as these features ceramics, weapons and funeral rite of warriors, ring-seals and attributes of supreme authority – helmets and tamgas. It is possible that in the course of research this range of sources can be increased. Therefore, this work serves as an impulse for the development of scientific research in this direction.

  14. WAIST CIRCUMFERENCE AS INDICATOR COMPONENTS OF METABOLIC SYNDROME IN THE SIBERIAN POPULATION

    Directory of Open Access Journals (Sweden)

    G. I. Simonova

    2014-01-01

    Full Text Available Object of research: to determine the cut-off point of waist circumference (WC identify the components of metabolic syndrome (MS in a large industrial center of Western Siberia.In the period from 2003 to 2005 in the screening population surveyed 9362 people, including 4268 men (45.6% and 5094 women (54.4%.The response rate was 61%. The study protocol included a sociodemographic data, measurement of blood pressure (BP, anthropometry (height, weight, WC, the definition of biochemical parameters. Statistical analysis was performed using the package SPSS. To determine the cut-off points of the used ROC model.In the group with ≥2 components of MS cut-off point WC from the men was 93.3 cm (sensitivity 72%, specificity 83%, women – 90.2 cm (sensitivity 72%, specificity 62%.The lowest cut-off point WC marked BP ≥ 130/85 mm Hg for men – 90 cm (sensitivity 66.8%, specificity 58.1%, for women – 86.5 cm (sensitivity 71.0%, specificity 55.7%. The highest cut-off point from the defined patients with diabetes for men was 99.0 cm (sensitivity 61%, specificity 70.2%, for women – cm (sensitivity 64.1%, specificity 65.9%.Conclusions: Cut-off point from the persons with the presence of ≥2 MS components in Siberian population 45–69 years, in accordance with the ROC analysis are 93.3 cm for men and 90.2 cm for women. The lowest cut-off point WC marked BP ≥ 130/85 mm Hg for men – 90 cm, for women – 86.5 cm. The highest cut-off point from the defined patients with diabetes for men was 99.0 cm, for women – 95 cm.

  15. High resilience in the Yamal-Nenets social-ecological system, West Siberian Arctic, Russia.

    Science.gov (United States)

    Forbes, Bruce C; Stammler, Florian; Kumpula, Timo; Meschtyb, Nina; Pajunen, Anu; Kaarlejärvi, Elina

    2009-12-29

    Tundra ecosystems are vulnerable to hydrocarbon development, in part because small-scale, low-intensity disturbances can affect vegetation, permafrost soils, and wildlife out of proportion to their spatial extent. Scaling up to include human residents, tightly integrated arctic social-ecological systems (SESs) are believed similarly susceptible to industrial impacts and climate change. In contrast to northern Alaska and Canada, most terrestrial and aquatic components of West Siberian oil and gas fields are seasonally exploited by migratory herders, hunters, fishers, and domesticated reindeer (Rangifer tarandus L.). Despite anthropogenic fragmentation and transformation of a large proportion of the environment, recent socioeconomic upheaval, and pronounced climate warming, we find the Yamal-Nenets SES highly resilient according to a few key measures. We detail the remarkable extent to which the system has successfully reorganized in response to recent shocks and evaluate the limits of the system's capacity to respond. Our analytical approach combines quantitative methods with participant observation to understand the overall effects of rapid land use and climate change at the level of the entire Yamal system, detect thresholds crossed using surrogates, and identify potential traps. Institutional constraints and drivers were as important as the documented ecological changes. Particularly crucial to success is the unfettered movement of people and animals in space and time, which allows them to alternately avoid or exploit a wide range of natural and anthropogenic habitats. However, expansion of infrastructure, concomitant terrestrial and freshwater ecosystem degradation, climate change, and a massive influx of workers underway present a looming threat to future resilience.

  16. High resilience in the Yamal-Nenets social–ecological system, West Siberian Arctic, Russia

    Science.gov (United States)

    Forbes, Bruce C.; Stammler, Florian; Kumpula, Timo; Meschtyb, Nina; Pajunen, Anu; Kaarlejärvi, Elina

    2009-01-01

    Tundra ecosystems are vulnerable to hydrocarbon development, in part because small-scale, low-intensity disturbances can affect vegetation, permafrost soils, and wildlife out of proportion to their spatial extent. Scaling up to include human residents, tightly integrated arctic social-ecological systems (SESs) are believed similarly susceptible to industrial impacts and climate change. In contrast to northern Alaska and Canada, most terrestrial and aquatic components of West Siberian oil and gas fields are seasonally exploited by migratory herders, hunters, fishers, and domesticated reindeer (Rangifer tarandus L.). Despite anthropogenic fragmentation and transformation of a large proportion of the environment, recent socioeconomic upheaval, and pronounced climate warming, we find the Yamal-Nenets SES highly resilient according to a few key measures. We detail the remarkable extent to which the system has successfully reorganized in response to recent shocks and evaluate the limits of the system's capacity to respond. Our analytical approach combines quantitative methods with participant observation to understand the overall effects of rapid land use and climate change at the level of the entire Yamal system, detect thresholds crossed using surrogates, and identify potential traps. Institutional constraints and drivers were as important as the documented ecological changes. Particularly crucial to success is the unfettered movement of people and animals in space and time, which allows them to alternately avoid or exploit a wide range of natural and anthropogenic habitats. However, expansion of infrastructure, concomitant terrestrial and freshwater ecosystem degradation, climate change, and a massive influx of workers underway present a looming threat to future resilience. PMID:20007776

  17. Inhibition of matrix metalloproteinases in Siberian hamsters impedes photostimulated recrudescence of ovaries.

    Science.gov (United States)

    Whited, Julie; Shahed, Asha; McMichael, Carling F; Young, Kelly A

    2010-12-01

    Exposure of Siberian hamsters to short photoperiod for 14 weeks induces ovarian regression. Subsequent transfer to long photoperiod restores ovarian function, and 2 weeks of photostimulation increases plasma estradiol (E(2)), antral follicles, and corpora lutea (CL). Because tissue remodeling involved with photostimulated ovarian recrudescence is associated with differential expression of matrix metalloproteinases (MMPs), we hypothesized that inhibiting MMP activity using a broad-spectrum in vivo MMP inhibitor, GM6001, would curtail recrudescence. One group of hamsters was placed in long days (LD; 16 h light:8 h darkness) for 16 weeks. Another group was placed in inhibitory short days (SD; 8 h light:16 h darkness) for 14 weeks. A third group was placed in SD for 14 weeks and transferred to LD for 2 weeks to stimulate recrudescence. During weeks 14-16, animals were either not treated or treated daily with i.p. injections of GM6001 (20 mg/kg) or vehicle (DMSO). GM6001 reduced gelatinase activity and decreased immunohistochemical staining for MMP1, MMP2, and MMP3 compared with vehicle. No differences between controls, vehicle, or GM6001 treatment were observed among LD animals, despite a trend toward reduction in CL and E(2) with GM6001. Although SD reduced ovarian function, photostimulation of transferred controls increased uterine mass, plasma E(2), appearance of antral follicles, and CL. With GM6001 treatment, photostimulation failed to increase uterine mass, plasma E(2), antral follicles, or CL. These data show, for the first time, that in vivo GM6001 administration inhibits MMP activity in hamster ovaries during photostimulation, and indicate that this inhibition may impede photostimulated recrudescence of ovaries. This study suggests an intriguing link between MMP activity and return to ovarian function during photostimulated recrudescence.

  18. Rapid changes in ovarian mRNA induced by brief photostimulation in Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    Shahed, Asha; McMichael, Carling F; Young, Kelly A

    2015-11-01

    This study sought to characterize the rapid intraovarian mRNA response of key folliculogenic factors that may contribute to the restoration of folliculogenesis during 2-10 days of photostimulation in Siberian hamsters. Adult hamsters were exposed to short photoperiod (8L:16D) for 14 weeks (SD). A subset were then transferred to long photoperiod (16L:8D) for 2 (PT day-2), 4 (PT day-4), or 10 days (PT day-10). Quantitative real-time PCR was used to measure intraovarian mRNA expression of: gonadotropin releasing hormone (GnRH), follicle stimulating hormone β-subunit (FSHβ-subunit), luteinizing hormone β-subunit (LHβ-subunit), FSH and LH receptors, estrogen receptors α and β (Esr1 and Esr2), matrix metalloproteinase (MMP)-2 and -9, anti-Müllerian hormone (AMH), inhibin-α subunit, fibroblast growth factor-2 (FGF-2) and proliferating cell nuclear antigen (PCNA). Compared to SD, plasma FSH concentrations increased on PT day-4 and the number of antral follicles and corpora lutea increased on PT day-10. FSHR and inhibin-α mRNA expression also increased on PT day-4, whereas LHR and proliferation marker PCNA both increased on PT day-10 as compared to SD. Esr1 mRNA increased on PT day-2 and remained significantly increased as compared to SD, whereas Esr1 mRNA increased only on PT day-2, similar to FGF-2 and MMP-2 results. No differences were observed in mRNA expression in ovarian GnRH, FSHβ- and LHβ-subunits, AMH, and MMP-9 mRNA with 2-10 days of photostimulation. Rapid increases in intraovarian FSHR and inhibin-α mRNA and antral follicle/corpora lutea numbers suggest that the ovary is primed to react quickly to the FSH released in response to brief periods of photostimulation.

  19. Pubertal growth of the medial amygdala delayed by short photoperiods in the Siberian hamster, Phodopus sungorus.

    Science.gov (United States)

    Cooke, Bradley M; Jordan, Cynthia L; Breedlove, S Marc

    2007-09-01

    We investigated whether puberty influences the morphology of the medial nucleus of the amygdala (MeA) by comparing Siberian hamsters (Phodopus sungorus) that had been raised from birth in either long day (LD; 16:8 h light:dark) or short day (SD; 8:16) photoperiods. Hamsters were sacrificed at 42-49 days of age, at which point all LD hamsters were reproductively mature, as evidenced by adult-like testes weights (mean: 657 mg). In contrast, the testes weights of the SD hamsters were low (mean: 31 mg), indicating that the SD photoperiod had delayed puberty. The regional volume and mean soma size of the four MeA subnuclei was estimated bilaterally by stereological procedures. In the posterior dorsal and ventral MeA subnuclei, regional volume was 22-25% larger, and mean soma size 18% larger, in LD males than SD males. Unbiased cell counts in the posterior dorsal MeA showed that LD and SD hamsters have equivalent neuron numbers. In the anterior MeA subnuclei, regional volumes and soma sizes from LD and SD hamsters were equivalent. Additionally, the regional volume of the posteroventral subnucleus was larger in the right hemisphere than the left, but this laterality did not respond to photoperiod manipulation. These results suggest that the extant neurons within the posterior MeA, a steroid-sensitive nucleus implicated in socio-sexual behavior, grow in response to the elevated levels of circulating androgen accompanying puberty, and that photoperiodic regulation of puberty affects morphological maturation of this nucleus.

  20. Schiff base protonation changes in Siberian hamster ultraviolet cone pigment photointermediates.

    Science.gov (United States)

    Mooney, Victoria L; Szundi, Istvan; Lewis, James W; Yan, Elsa C Y; Kliger, David S

    2012-03-27

    Molecular structure and function studies of vertebrate ultraviolet (UV) cone visual pigments are needed to understand the molecular evolution of these photoreceptors, which uniquely contain unprotonated Schiff base linkages between the 11-cis-retinal chromophore and the opsin proteins. In this study, the Siberian hamster ultraviolet cone pigment (SHUV) was expressed and purified in an n-dodecyl-β-D-maltoside suspension for optical characterization. Time-resolved absorbance measurements, over a spectral range from 300 to 700 nm, were taken for the purified pigment at time delays from 30 ns to 4.64 s after photoexcitation using 7 ns pulses of 355 nm light. The resulting data were fit globally to a sum of exponential functions after noise reduction using singular-value decomposition. Four exponentials best fit the data with lifetimes of 1.4 μs, 210 μs, 47 ms, and 1 s. The first photointermediate species characterized here is an equilibrated mixture similar to the one formed after rhodopsin's Batho intermediate decays into equilibrium with its successor, BSI. The extremely large red shift of the SHUV Batho component relative to the pigment suggests that SHUV Batho has a protonated Schiff base and that the SHUV cone pigment itself has an unprotonated Schiff base. In contrast to SHUV Batho, the portion of the equilibrated mixture's spectrum corresponding to SHUV BSI is well fit by a model spectrum with an unprotonated Schiff base. The spectra of the next two photointermediate species revealed that they both have unprotonated Schiff bases and suggest they are analogous to rhodopsin's Lumi I and Lumi II species. After decay of SHUV Lumi II, the correspondence with rhodopsin photointermediates breaks down and the next photointermediate, presumably including the G protein-activating species, is a mixture of protonated and unprotonated Schiff base photointermediate species.

  1. Tall shrub and tree expansion in Siberian tundra ecotones since the 1960s.

    Science.gov (United States)

    Frost, Gerald V; Epstein, Howard E

    2014-04-01

    Circumpolar expansion of tall shrubs and trees into Arctic tundra is widely thought to be occurring as a result of recent climate warming, but little quantitative evidence exists for northern Siberia, which encompasses the world's largest forest-tundra ecotonal belt. We quantified changes in tall shrub and tree canopy cover in 11, widely distributed Siberian ecotonal landscapes by comparing very high-resolution photography from the Cold War-era 'Gambit' and 'Corona' satellite surveillance systems (1965-1969) with modern imagery. We also analyzed within-landscape patterns of vegetation change to evaluate the susceptibility of different landscape components to tall shrub and tree increase. The total cover of tall shrubs and trees increased in nine of 11 ecotones. In northwest Siberia, alder (Alnus) shrubland cover increased 5.3-25.9% in five ecotones. In Taymyr and Yakutia, larch (Larix) cover increased 3.0-6.7% within three ecotones, but declined 16.8% at a fourth ecotone due to thaw of ice-rich permafrost. In Chukotka, the total cover of alder and dwarf pine (Pinus) increased 6.1% within one ecotone and was little changed at a second ecotone. Within most landscapes, shrub and tree increase was linked to specific geomorphic settings, especially those with active disturbance regimes such as permafrost patterned-ground, floodplains, and colluvial hillslopes. Mean summer temperatures increased at most ecotones since the mid-1960s, but rates of shrub and tree canopy cover expansion were not strongly correlated with temperature trends and were better correlated with mean annual precipitation. We conclude that shrub and tree cover is increasing in tundra ecotones across most of northern Siberia, but rates of increase vary widely regionally and at the landscape scale. Our results indicate that extensive changes can occur within decades in moist, shrub-dominated ecotones, as in northwest Siberia, while changes are likely to occur much more slowly in the highly continental

  2. Independence of circadian entrainment state and responses to melatonin in male Siberian hamsters

    Directory of Open Access Journals (Sweden)

    Gorman Michael R

    2003-10-01

    Full Text Available Abstract Background Seasonal fluctuations in physiology and behavior depend on the duration of nocturnal melatonin secretion programmed by the circadian system. A melatonin signal of a given duration, however, can elicit different responses depending on whether an animal was previously exposed to longer or shorter photoperiod signals (i.e., its photoperiodic history. This report examined in male Siberian hamsters which of two aspects of photoperiod history – prior melatonin exposure or entrainment state of the circadian system – is critical for generating contingent responses to a common photoperiodic signal. Results In Experiment #1, daily melatonin infusions of 5 or 10 h duration stimulated or inhibited gonadal growth, respectively, but had no effect on entrainment of the locomotor activity rhythm to long or short daylengths, thereby demonstrating that melatonin history and entrainment status could be experimentally dissociated. These manipulations were repeated in Experiment #2, and animals were subsequently exposed to a 12 week regimen of naturalistic melatonin signals shown in previous experiments to reveal photoperiodic history effects. Gonadal responses differed as a function of prior melatonin exposure but were unaffected by the circadian entrainment state. Experiment #3 demonstrated that a new photoperiodic history could be imparted during four weeks of exposure to long photoperiods. This effect, moreover, was blocked in animals treated concurrently with constant release melatonin capsules that obscured the endogenous melatonin signal: Following removal of the implants, the gonadal response depended not on the immediately antecedent circadian entrainment state, but on the more remote photoperiodic conditions prior to the melatonin implant. Conclusions The interpretation of photoperiodic signals as a function of prior conditions depends specifically on the history of melatonin exposure. The photoperiodic regulation of circadian

  3. Co-Opetition (Coexisting Competition and Competitive Coexistaence in the Tourism Field in Siberian Regions

    Directory of Open Access Journals (Sweden)

    Olga Pavlovna Kuznetsova

    2017-03-01

    Full Text Available The relevance of the topic is due to the need to use of such category as “co-opetition” by public and local government authorities when implementing their powers in the tourism sphere. We divide the term “co-opetition” into two categories: “coexisting competition” and “competitive coexistence”. The problem field of the study is that in the conditions of crisis development, it is difficult to choose and implement new measures and approaches aimed at improving the economic situation in Russia and its regions, diversify the economy. In modern conditions, it is important and effective to develop domestic tourism and incoming tourism in Russia as well as its effective functioning. Russia has considerable natural and ecological, cultural and historical resources. However, the imperfection of the authorities operation and a mechanism of combined implementation of projects by different territories prevent the transformation of tourism industry into the economic powerhouse. In this regard, on the example of Siberian regions, we offer to the authorities to use co-opetition (in both of its meanings in the combined development of tourism and to establish on this basis the tourist mega-cluster “Fairy Siberia”. The study of foreign experience has allowed revealing the positions, in which Russia falls behind other countries-leaders in the tourism industry. The proposed approach is promising, and it is based on joint efforts of regions and saving money due to the economies of scale. At the same time, it allows the regions to develop their competitive advantages. The practical significance of the received results consists in the possibility of their use by the public and local authorities in the implementation of effective policy for the development of tourism industry.

  4. Anatomical and functional characterisation of a dopaminergic system in the suprachiasmatic nucleus of the neonatal Siberian hamster.

    Science.gov (United States)

    Duffield, G E; McNulty, S; Ebling, F J

    1999-05-24

    In altricial rodents, maternal influences entrain the developing circadian system in the perinatal period before the capacity to respond directly to photic cues develops. The aim of these studies was to investigate the potential role of dopamine in this process in the Siberian hamster. An initial study investigated the ontogeny of retinal innervation of the suprachiasmatic nuclei (SCN) by using cholera toxin B subunit as a tracer. This revealed that retinal fibres first innervate the SCN on postnatal day 3 (PD3), and ingrowth of fibres is extensive by PD6. In situ hybridisation studies revealed the presence of D1-dopamine receptor (D1-R) mRNA in the SCN on PD2, and levels of expression were similar in PD6 pups and adult hamsters. Immunocytochemical staining for tyrosine hydroxylase revealed abundant catecholaminergic fibres within the ventromedial zone of the SCN from the day of birth through PD20; however, in contrast, few fibres were present in adult SCN. Dopamine-beta-hydroxylase-immunoreactive fibres were absent from the neonatal and adult SCN, suggesting that the fibres in the SCN are dopaminergic. The function of this dopaminergic system was investigated by determining the effects of D1-R agonists on the expression of the immediate-early gene c-fos in the SCN. This was assessed in pups ages PD1- PD5 by in situ hybridisation and immunocytochemical localisation of its protein product. No induction was seen in the SCN, in marked contrast to studies in the developing rat. A final series of studies investigated dopaminergic function by determining whether a D1-agonist could induce phosphorylation of Ca2+/cyclic AMP response element-binding protein (CREB) on Ser133. Hypothalamic slices containing SCN taken from PD1 and PD2 hamsters were treated with D1-R agonists, and levels of phosphorylated CREB were assayed by Western blots. Phosphorylation of CREB was stimulated by D1-R agonists in both Syrian and Siberian hamster hypothalamus, but the response was far greater

  5. East African ROAD

    Science.gov (United States)

    Tekle, Kelali

    2016-10-01

    In the developing world astronomy had been treated as the science of elites. As a result of this overwhelming perception, astronomy compared with other applied sciences has got less attention and its role in development has been insignificant. However, the IAU General Assembly decision in 2009 opened new opportunity for countries and professionals to deeply look into Astronomy and its role in development. Then, the subsequent establishment of regional offices in the developing world is helping countries to integrate astronomy with other earth and space based sciences so as to progressively promote its scientific and development importance. Gradually nations have come to know that space is the frontier of tomorrow and the urgency of preeminence on space frontier starts at primary school and ascends to tertiary education. For this to happen, member nations in east African region have placed STEM education at the center of their education system. For instance, Ethiopian has changed University enrollment strategy to be in favor of science and engineering subjects, i.e. every year seventy percent of new University entrants join science and engineering fields while thirty percent social science and humanities. Such bold actions truly promote astronomy to be conceived as gateway to science and technology. To promote the concept of astronomy for development the East African regional office has actually aligned it activities to be in line with the focus areas identified by the IAU strategy (2010 to 2020).

  6. Vertical velocity of mantle flow of East Asia and adjacent areas

    Institute of Scientific and Technical Information of China (English)

    CHENG Xianqiong; ZHU Jieshou; CAI Xuelin

    2007-01-01

    Based on the high-resolution body wave tomo- graphic image and relevant geophysical data, we calculated the form and the vertical and tangential velocities of mantle flow. We obtained the pattern of mantle convection for East Asia and the West Pacific. Some important results and under- standings are gained from the images of the vertical velocity of mantle flow for East Asia and the West Pacific. There is an upwelling plume beneath East Asia and West Pacific, which is the earth's deep origin for the huge rift valley there. We have especially outlined the tectonic features of the South China Sea, which is of the "工" type in the upper mantle shield type in the middle and divergent in the lower; the Siberian clod downwelling dives from the surface to near Core and mantle bounary (CMB), which is convergent in the upper mantle and divergent in the lower mantle; the Tethyan subduction region, centered in the Qinghai-Tibet plateau, is visible from 300 to 2 000 km, which is also convergent in the upper mantle and divergent in the lower mantle. The three regions of mantle convection beneath East Asia and the West Pacific are in accordance with the West Pacific, Ancient Asia and the Tethyan structure regions. The mantle upwelling orig- inates from the core-mantle boundary and mostly occurs in the middle mantle and the lower part of the upper mantle. The velocities of the vertical mantle flow are about 1-4 cm per year and the tangential velocities are 1-10 cm per year. The mantle flow has an effect on controlling the movement of plates and the distributions of ocean ridges, subduction zones and collision zones. The mantle upwelling regions are clearly related with the locations ofhotspots on the earth's surface.

  7. Change in dust seasonality as the primary driver for orbital-scale dust storm variability in East Asia

    Science.gov (United States)

    Serno, Sascha; Winckler, Gisela; Anderson, Robert F.; Jaccard, Samuel L.; Kienast, Stephanie S.; Haug, Gerald H.

    2017-04-01

    Glacial periods are recognized to be dustier than interglacials, but the conditions leading to greater dust mobilization are poorly defined. Here we present a new high-resolution dust record based on 230Th-normalized 4He flux from Ocean Drilling Program site 882 in the Subarctic North Pacific covering the last 170,000 years. By analogy with modern relationships, we infer the mechanisms controlling orbital-scale dust storm variability in East Asia. We propose that orbital-scale dust flux variability is the result of an expansion of the dust season into summer, in addition to more intense dust storms during spring and fall. The primary drivers influencing dust flux include summer insolation at subarctic latitudes and variable Siberian alpine glaciation, which together control the cold air reservoir in Siberia. Changes in the extent of the Northern Hemisphere ice sheets may be a secondary control.

  8. East Candor Chasma

    Science.gov (United States)

    1997-01-01

    During its examination of Mars, the Viking 1 spacecraft returned images of Valles Marineris, a huge canyon system 5,000 km long, up to 240 km wide, and 6.5 km deep, whose connected chasma or valleys may have formed from a combination of erosional collapse and structural activity. The view shows east Candor Chasma, one of the connected valleys of Valles Marineris; north toward top of frame; for scale, the impact crater in upper right corner is 15 km (9 miles) wide. The image, centered at latitude 7.5 degrees S., longitude 67.5 degrees, is a composite of Viking 1 Orbiter high-resolution (about 80 m/pixel or picture element) images in black and white and low-resolution (about 250 m/pixel) images in color. The Viking 1 craft landed on Mars in July of 1976. East Candor Chasma occupies the eastern part of the large west-northwest-trending trough of Candor Chasma. This section is about 150 km wide. East Candor Chasma is bordered on the north and south by walled cliffs, most likely faults. The walls may have been dissected by landslides forming reentrants; one area on the north wall shows what appears to be landslide debris. Both walls show spur-and-gully morphology and smooth sections. In the lower part of the image northwest-trending, linear depressions on the plateau are younger graben or fault valleys that cut the south wall. Material central to the chasma shows layering in places and has been locally eroded by the wind to form flutes and ridges. These interior layered deposits have curvilinear reentrants carved into them, and in one locale a lobe flows away from the top of the interior deposit. The lobe may be mass-wasting deposits due to collapse of older interior deposits (Lucchitta, 1996, LPSC XXVII abs., p. 779- 780); this controversial idea requires that the older layered deposits were saturated with ice, perhaps from former lakes, and that young volcanism and/or tectonism melted the ice and made the material flow.

  9. The Danish East India Company

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig

    2005-01-01

    The article analysis the first Danish East India Company incorporated in 1616, which was the first Danish Stock Company and which has impacts even on modern Danish company la......The article analysis the first Danish East India Company incorporated in 1616, which was the first Danish Stock Company and which has impacts even on modern Danish company la...

  10. Acute melatonin treatment alters dendritic morphology and circadian clock gene expression in the hippocampus of Siberian hamsters.

    Science.gov (United States)

    Ikeno, Tomoko; Nelson, Randy J

    2015-02-01

    In the hippocampus of Siberian hamsters, dendritic length and dendritic complexity increase in the CA1 region whereas dendritic spine density decreases in the dentate gyrus region at night. However, the underlying mechanism of the diurnal rhythmicity in hippocampal neuronal remodeling is unknown. In mammals, most daily rhythms in physiology and behaviors are regulated by a network of circadian clocks. The central clock, located in the hypothalamus, controls melatonin secretion at night and melatonin modifies peripheral clocks by altering expression of circadian clock genes. In this study, we examined the effects of acute melatonin treatment on the circadian clock system as well as on morphological changes of hippocampal neurons. Male Siberian hamsters were injected with melatonin in the afternoon; 4 h later, mRNA levels of hypothalamic and hippocampal circadian clock genes and hippocampal neuron dendritic morphology were assessed. In the hypothalamus, melatonin treatment did not alter Period1 and Bmal1 expression. However, melatonin treatment increased both Period1 and Bmal1 expression in the hippocampus, suggesting that melatonin affected molecular oscillations in the hippocampus. Melatonin treatment also induced rapid remodeling of hippocampal neurons; melatonin increased apical dendritic length and dendritic complexity in the CA1 region and reduced the dendritic spine density in the dentate gyrus region. These data suggest that structural changes in hippocampal neurons are regulated by a circadian clock and that melatonin functions as a nighttime signal to coordinate the diurnal rhythm in neuronal remodeling.

  11. Construction and analysis of Siberian tiger bacterial artificial chromosome library with approximately 6.5-fold genome equivalent coverage.

    Science.gov (United States)

    Liu, Changqing; Bai, Chunyu; Guo, Yu; Liu, Dan; Lu, Taofeng; Li, Xiangchen; Ma, Jianzhang; Ma, Yuehui; Guan, Weijun

    2014-03-07

    Bacterial artificial chromosome (BAC) libraries are extremely valuable for the genome-wide genetic dissection of complex organisms. The Siberian tiger, one of the most well-known wild primitive carnivores in China, is an endangered animal. In order to promote research on its genome, a high-redundancy BAC library of the Siberian tiger was constructed and characterized. The library is divided into two sub-libraries prepared from blood cells and two sub-libraries prepared from fibroblasts. This BAC library contains 153,600 individually archived clones; for PCR-based screening of the library, BACs were placed into 40 superpools of 10 × 384-deep well microplates. The average insert size of BAC clones was estimated to be 116.5 kb, representing approximately 6.46 genome equivalents of the haploid genome and affording a 98.86% statistical probability of obtaining at least one clone containing a unique DNA sequence. Screening the library with 19 microsatellite markers and a SRY sequence revealed that each of these markers were present in the library; the average number of positive clones per marker was 6.74 (range 2 to 12), consistent with 6.46 coverage of the tiger genome. Additionally, we identified 72 microsatellite markers that could potentially be used as genetic markers. This BAC library will serve as a valuable resource for physical mapping, comparative genomic study and large-scale genome sequencing in the tiger.

  12. Ancient DNA analysis of the oldest canid species from the Siberian Arctic and genetic contribution to the domestic dog.

    Directory of Open Access Journals (Sweden)

    Esther J Lee

    Full Text Available Modern Arctic Siberia provides a wealth of resources for archaeological, geological, and paleontological research to investigate the population dynamics of faunal communities from the Pleistocene, particularly as the faunal material coming from permafrost has proven suitable for genetic studies. In order to examine the history of the Canid species in the Siberian Arctic, we carried out genetic analysis of fourteen canid remains from various sites, including the well-documented Upper Paleolithic Yana RHS and Early Holocene Zhokhov Island sites. Estimated age of samples range from as recent as 1,700 years before present (YBP to at least 360,000 YBP for the remains of the extinct wolf, Canis cf. variabilis. In order to examine the genetic affinities of ancient Siberian canids species to the domestic dog and modern wolves, we obtained mitochondrial DNA control region sequences and compared them to published ancient and modern canid sequences. The older canid specimens illustrate affinities with pre-domestic dog/wolf lineages while others appear in the major phylogenetic clades of domestic dogs. Our results suggest a European origin of domestic dog may not be conclusive and illustrates an emerging complexity of genetic contribution of regional wolf breeds to the modern Canis gene pool.

  13. Net ecosystem exchange and energy fluxes measured with the eddy covariance technique in a western Siberian bog

    Directory of Open Access Journals (Sweden)

    P. Alekseychik

    2017-08-01

    Full Text Available Very few studies of ecosystem–atmosphere exchange involving eddy covariance data have been conducted in Siberia, with none in the western Siberian middle taiga. This work provides the first estimates of carbon dioxide (CO2 and energy budgets in a typical bog of the western Siberian middle taiga based on May–August measurements in 2015. The footprint of measured fluxes consisted of a homogeneous mixture of tree-covered ridges and hollows with the vegetation represented by typical sedges and shrubs. Generally, the surface exchange rates resembled those of pine-covered bogs elsewhere. The surface energy balance closure approached 100 %. Net CO2 uptake was comparatively high, summing up to 202 gC m−2 for the four measurement months, while the Bowen ratio was seasonally stable at 28 %. The ecosystem turned into a net CO2 source during several front passage events in June and July. The periods of heavy rain helped keep the water table at a sustainably high level, preventing a usual drawdown in summer. However, because of the cloudy and rainy weather, the observed fluxes might rather represent the special weather conditions of 2015 than their typical magnitudes.

  14. Net ecosystem exchange and energy fluxes measured with the eddy covariance technique in a western Siberian bog

    Science.gov (United States)

    Alekseychik, Pavel; Mammarella, Ivan; Karpov, Dmitry; Dengel, Sigrid; Terentieva, Irina; Sabrekov, Alexander; Glagolev, Mikhail; Lapshina, Elena

    2017-08-01

    Very few studies of ecosystem-atmosphere exchange involving eddy covariance data have been conducted in Siberia, with none in the western Siberian middle taiga. This work provides the first estimates of carbon dioxide (CO2) and energy budgets in a typical bog of the western Siberian middle taiga based on May-August measurements in 2015. The footprint of measured fluxes consisted of a homogeneous mixture of tree-covered ridges and hollows with the vegetation represented by typical sedges and shrubs. Generally, the surface exchange rates resembled those of pine-covered bogs elsewhere. The surface energy balance closure approached 100 %. Net CO2 uptake was comparatively high, summing up to 202 gC m-2 for the four measurement months, while the Bowen ratio was seasonally stable at 28 %. The ecosystem turned into a net CO2 source during several front passage events in June and July. The periods of heavy rain helped keep the water table at a sustainably high level, preventing a usual drawdown in summer. However, because of the cloudy and rainy weather, the observed fluxes might rather represent the special weather conditions of 2015 than their typical magnitudes.

  15. Seasonal and annual variation of carbon fluxes in a young Siberian larch (Larix sibirica plantation in Iceland

    Directory of Open Access Journals (Sweden)

    B. D. Sigurdsson

    2009-07-01

    Full Text Available This study reports 3-year measurements (2004–2006 of net ecosystem exchange (NEE over a 12–14 year old Siberian larch forest in Iceland established on previously grazed heath land pasture that had been site-prepared prior to planting. The study evaluated interannual and seasonal variation of NEE and its component fluxes, gross primary production (GPP and ecosystem respiration (Re, with the aim to clarify how climatic factors controlled the site's carbon balance. The young plantation acted as a relatively strong sink for CO2 during all of the three years, with a net sequestration of −375, −566 and −245 g CO2 m−2 for years 2004, 2005 and 2006, respectively. The annual carbon balance was strongly influenced by climatic factors leading to a high inter-annual variability in NEE. This variation was more related to variation in carbon efflux (Re than carbon uptake (GPP. The abiotic factors that showed the strongest correlation to Re were air temperature during the growing season and soil water potential. The GPP mostly followed the seasonal pattern in irradiance, except in 2005, when the plantation experienced severe spring frost damage that set the GPP back to zero. It was not expected that the rather slow-growing Siberian larch plantation would be such a strong sink for atmospheric CO2 only twelve years after site preparation and afforestation.

  16. Orchestration of gene expression across the seasons: Hypothalamic gene expression in natural photoperiod throughout the year in the Siberian hamster.

    Science.gov (United States)

    Petri, Ines; Diedrich, Victoria; Wilson, Dana; Fernández-Calleja, José; Herwig, Annika; Steinlechner, Stephan; Barrett, Perry

    2016-07-11

    In nature Siberian hamsters utilize the decrement in day length following the summer solstice to implement physiological adaptations in anticipation of the forthcoming winter, but also exploit an intrinsic interval timer to initiate physiological recrudescence following the winter solstice. However, information is lacking on the temporal dynamics in natural photoperiod of photoperiodically regulated genes and their relationship to physiological adaptations. To address this, male Siberian hamsters born and maintained outdoors were sampled every month over the course of one year. As key elements of the response to photoperiod, thyroid hormone signalling components were assessed in the hypothalamus. From maximum around the summer solstice (late-June), Dio2 expression rapidly declined in advance of physiological adaptations. This was followed by a rapid increase in Mct8 expression (T3/T4 transport), peaking early-September before gradually declining to minimum expression by the following June. Dio3 showed a transient peak of expression beginning late-August. A recrudescence of testes and body mass occurred from mid-February, but Dio2 expression remained low until late-April of the following year, converging with the time of year when responsiveness to short-day length is re-established. Other photoperiodically regulated genes show temporal regulation, but of note is a transient peak in Gpr50 around late-July.

  17. Photoperiodic regulation of histamine H3 receptor and VGF messenger ribonucleic acid in the arcuate nucleus of the Siberian hamster.

    Science.gov (United States)

    Barrett, Perry; Ross, Alexander W; Balik, Ales; Littlewood, Pauline A; Mercer, Julian G; Moar, Kim M; Sallmen, Tina; Kaslin, Jan; Panula, Pertti; Schuhler, Sandrine; Ebling, Francis J; Ubeaud, Caroline; Morgan, Peter J

    2005-04-01

    To survive winter the Siberian hamster has evolved profound physiological and behavioral adaptations, including a moult to winter pelage, regression of the reproductive axis, onset of daily torpor and increased capacity for thermogenesis. However, one of the most striking adaptations is the catabolism of intraabdominal and sc fat reserves contributing to the loss of up to 40% of body weight. These physiological and behavioral adaptations are photoperiodically driven, yet neither the site(s) in the brain nor the molecular mechanism(s) involved in the regulation of these profound adaptations is known. Here we report a dynamic regulation of gene expression in a dorsal region of the medial posterior area of the arcuate nucleus (dmpARC) of the Siberian and Syrian hamster brain in response to altered photoperiod. We show mRNA for the histamine H3 receptor is down-regulated and VGF is up-regulated in the dmpARC in hamsters switched from long- to short-day photoperiod. These data provide further evidence to support the view that the dmpARC is a major site to relay photoperiodic changes and as a site for the long-term regulation of seasonal physiology and behavior.

  18. Fos-like immunoreactivity in Siberian hamster brain during initiation of torpor-like hypothermia induced by 2DG.

    Science.gov (United States)

    Park, Jin Ho; Dark, John

    2007-08-01

    Systemic 2-deoxy-d-glucose (2DG) produces pronounced torpor-like hypothermia (notSiberian hamster. Siberian hamsters are heterothermic, naturally undergoing photoperiod-dependent torpor during winter-like photoperiods. Fos was used to identify neural structures activated during the initiation of torpor-like hypothermia induced by 2DG treatment. The Fos-like immunoreactivity (Fos-li) in the area postrema and nucleus of the solitary tract that predominantly characterizes other 2DG-induced responses was absent during 2DG-induced torpor in the present experiment. Fos-li was seen in a number of forebrain and hindbrain sites during entry into hypothermia, but the densest Fos-li was found in the parvocellular portion of the paraventricular nucleus. Fos-li in the medial nucleus of the amygdala and the dorsal lateral septum also distinguished 2DG-induced torpor from other 2DG-induced behaviors. The possible involvement of neuropeptide Y pathways during 2DG-induced expression of reversible hypothermia is discussed.

  19. New evidence of Holocene atmospheric circulation dynamics based on lake sediments from southern Sweden: a link to the Siberian High

    Science.gov (United States)

    Muschitiello, F.; Schwark, L.; Wohlfarth, B.; Sturm, C.; Hammarlund, D.

    2013-10-01

    Oxygen (δ18O) and carbon (δ13C) isotope records of calcitic carbonate components (Chara sp. algal encrustations and Bithynia tentaculata gastropod opercula) from a lake-sediment succession on the Baltic Sea island of Gotland, south-eastern Sweden, have been obtained to investigate regional climate dynamics during the Holocene. The hydrological sensitivity of the small lake, particularly in terms of spring snowmelt contribution to the local water budget, provides a means of tracing past changes in the influence of snow-bearing easterly winds across the Baltic Sea Proper, which signifies the wintertime strength of the Siberian High. Repeated episodic depletions in 18O at the centennial scale correlate with events of increased potassium concentration in the GISP2 ice-core record from Greenland, which indicates a coupling to large-scale fluctuations in atmospheric circulation patterns. A corresponding correlation with simultaneous depletions in 13C suggests repeated responses of the local lake hydrology to snow-rich winters through decreasing water residence time, perhaps augmented by methanogenesis due to prolonged ice-cover seasons under the influence of an expanding Siberian High. Frequency analysis of the isotopic records reveals well-defined fluctuations at quasi-500-520-, 670-, 830- and 1430-yr periodicities, and a gradually stronger impact of Polar air outbreaks across the southern Baltic Sea region with time after ca 6000 cal. BP.

  20. Low-Ti melts from the southeastern Siberian Traps Large Igneous Province: Evidence for a water-rich mantle source?

    Indian Academy of Sciences (India)

    Alexei V Ivanov; Elena I Demonterova; Sergei V Rasskazov; Tatyana A Yasnygina

    2008-02-01

    Siberian Traps Large Igneous Province (STLIP) is one of the most voluminous volcanic provinces on Earth. The dominant erupted rocks are low-Ti basalts, which make up 80% by volume of the classical Noril’sk lava sequence. In the west Siberian basin and Maymecha-Kotuy area, the low- Ti basalts make up about 99% and 50% by volume, respectively. Dolerite sills in the Angara– Taseevskaya Syncline at the southeastern STLIP exhibit trace element patterns and Sr isotope ratios typical of the low-Ti basalts of the Noril’sk sequence. The most Mg-rich (MgO 9.5–11 wt%) and hence least differentiated dolerites are characterized by trace element patterns with Ta-Nb depletion, low Ce/Pb and high Sr/Pr. These trace element features are similar to water-saturated, mantle wedge-derived island arc basalts. These imply an important role of subduction fluid-derived trace elements in the source of melting beneath the Angara–Taseevskaya Syncline and other regions of the STLIP. Less magnesium rocks (MgO 3.8–6.1 wt%) with less prominent Ta-Nb depletion, higher Ce/Pb and lower Sr/Pr could be produced via olivine-plagioclase fractionation of primary high-magnesium melts.

  1. [Distribution of the genetic diversity of the Siberian stone pine, Pinus sibirica Du Tour, along the latitudinal and longitudinal profiles].

    Science.gov (United States)

    Petrova, E A; Goroshkevich, S N; Belokon', M M; Belokon', Iu S; Politov, D V

    2014-05-01

    The Siberian stone pine (Pinus sibirica Du Tour) is one of the main forest-forming coniferous species of the boreal ecosystems of Western Siberia. We used the isozyme method to analyze 11 ecotypes representing the latitudinal and longitudinal profiles within the species range, including samples from the geographic boundaries of the distribution. The genetic structure of the ecotypes is described on the basis of the variability for 26 isozyme loci encoding for 16 enzyme systems. The greatest genetic diversity was observed in the taiga ecotypes in the central part of the studied area, while the ecotypes along the species range boundaries were shown to be genetically depauperized. Approximately 8.1% of the observed genetic diversity is attributed to differences between the studied ecotypes. We detected high levels of genetic diversity for the Fest_2, Pgm_1, Sod_4, and a few otherloci, as well as a correlation between allele frequencies and geographical locations of the populations. The results of multivariate analysis of allelic frequencies as well as cluster analysis allowed us to discriminate three major groups of ecotypes: north-eastern, central and south-western. In view of our results, we compare two hypotheses: one which attributes the spatial distribution of genetic variations to the selectivity for some of the polymorphic allozyme loci, and the other based in the history of the formation of the range of the Siberian stone pine.

  2. Dietary Administration of Lactobacillus plantarum Enhanced Growth Performance and Innate Immune Response of Siberian Sturgeon, Acipenser baerii.

    Science.gov (United States)

    Pourgholam, Moheb Ali; Khara, Hossein; Safari, Reza; Sadati, Mohammad Ali Yazdani; Aramli, Mohammad Sadegh

    2016-03-01

    We investigated the effects of Lactobacillus plantarum used as a dietary supplement on the growth performance and innate immune response in juvenile Siberian sturgeon Acipenser baerii. Juvenile fish (14.6 ± 2.3 g) were fed three experimental diets prepared by supplementing a basal diet with L. plantarum at different concentrations [1 × 10(7), 1 × 10(8) and 1 × 10(9) colony-forming units (cfu) g(-1)] and a control (non-supplemented basal) diet for 8 weeks. Growth performance indices were increased in fish fed the 1 × 10(8) cfu g(-1) L. plantarum diet compared to the other groups. There was an increased innate immune response in fish fed the experimental diets. The highest levels of lysozyme activity, total immunoglobulin (IgM) and complement component 3 (C3) were observed in fish fed the diet containing L. plantarum at a concentration of 1 × 10(8) cfu g(-1), but there was no significant difference in the level of complement component 4 (C4) in fish fed the experimental diets or the control diet. The present study underlying some positive effects (growth performance and immune indices) of dietary administration of L. plantarum at a concentration of 1 × 10(8) cfu g(-1) in the Siberian sturgeon.

  3. FosB in the suprachiasmatic nucleus of the Syrian and Siberian hamster.

    Science.gov (United States)

    Ebling, F J; Maywood, E S; Mehta, M; Hancock, D C; McNulty, S; De Bono, J; Bray, S J; Hastings, M H

    1996-01-01

    The suprachiasmatic nucleus (SCN) generates circadian rhythms of behavior and hormone secretion in mammals, and integrates responses to light and nonphotic stimuli to synchronize such rhythms with the external environment. Previous studies have demonstrated a close association between the induction of the immediate early gene (IEG) c-fos in the SCN by light and phase shifts of circadian rhythms induced by light, but nonphotic stimuli (e.g., arousal), which also cause phase shifts, do not increase c-fos expression in the SCN. Because c-fos is now known to be a member of a large family of IEGs which can regulate transcription and thus cellular function, the aim of the current study was to determine whether induction of another member of this immediate early gene family, fosB, is associated with photic and nonphotic phase shifts. An antiserum that recognizes a unique peptide sequence derived from FosB was produced so that the expression of fosB could be investigated in cells within the SCN by immunocytochemical detection of its protein product. The regional distribution of FosB-immunoreactive (ir) cells in the SCN of Syrian and Siberian hamsters was broadly similar to that for c-Fos-ir cells. However, whereas c-fos expression in the SCN was constitutively low, but could be massively induced by light at particular circadian phases, FosB-ir cells were present at all circadian phases studied, irrespective of photic stimulation, and light only produced marginal increases in the number of FosB-ir cells compared with nonstimulated controls. Moreover, blockade of glutamatergic neurotransmission by pretreatment of hamsters with the NMDA receptor antagonist MK801 significantly reduced photic induction of c-Fos-ir cells, but did not influence the number of FosB-ir cells in the SCN. Finally, an arousing nonphotic stimulus known to cause phase advances in wheel-running behavior in Syrian hamsters did not alter significantly the number of FosB-ir cells in the SCN. These

  4. Photoperiod affects the diurnal rhythm of hippocampal neuronal morphology of Siberian hamsters.

    Science.gov (United States)

    Ikeno, Tomoko; Weil, Zachary M; Nelson, Randy J

    2013-11-01

    Individuals of many species can regulate their physiology, morphology, and behavior in response to annual changes of day length (photoperiod). In mammals, the photoperiodic signal is mediated by a change in the duration of melatonin, leading to alterations in gene expressions, neuronal circuits, and hormonal secretion. The hippocampus is one of the most plastic structures in the adult brain and hippocampal neuronal morphology displays photoperiod-induced differences. Because the hippocampus is important for emotional and cognitive behaviors, photoperiod-driven remodeling of hippocampal neurons is implicated in seasonal differences of affect, including seasonal affective disorder (SAD) in humans. Because neuronal architecture is also affected by the day-night cycle in several brain areas, we hypothesized that hippocampal neuronal morphology would display a diurnal rhythm and that day length would influence that rhythm. In the present study, we examined diurnal and seasonal differences in hippocampal neuronal morphology, as well as mRNA expression of the neurotrophic factors (i.e., brain-derived neurotrophic factor [Bdnf], tropomyosin receptor kinase B [trkB; a receptor for BDNF], and vascular endothelial growth factor [Vegf]) and a circadian clock gene, Bmal1, in the hippocampus of Siberian hamsters. Diurnal rhythms in total length of dendrites, the number of primary dendrites, dendritic complexity, and distance of the furthest intersection from the cell body were observed only in long-day animals; however, diurnal rhythms in the number of branch points and mean length of segments were observed only in short-day animals. Spine density of dendrites displayed diurnal rhythmicity with different peak times between the CA1 and DG subregions and between long and short days. These results indicate that photoperiod affects daily morphological changes of hippocampal neurons and the daily rhythm of spine density, suggesting the possibility that photoperiod-induced adjustments

  5. Impacts of the July 2012 Siberian fire plume on air quality in the Pacific Northwest

    Science.gov (United States)

    Teakles, Andrew D.; So, Rita; Ainslie, Bruce; Nissen, Robert; Schiller, Corinne; Vingarzan, Roxanne; McKendry, Ian; Macdonald, Anne Marie; Jaffe, Daniel A.; Bertram, Allan K.; Strawbridge, Kevin B.; Leaitch, W. Richard; Hanna, Sarah; Toom, Desiree; Baik, Jonathan; Huang, Lin

    2017-02-01

    large air quality impacts seen during this event were a combination of the efficient transport of the plume across the Pacific, favourable entrainment conditions across the BC interior, and the large scale of the Siberian wildfire emissions. A warming climate increases the risk of increased wildfire activity and events of this scale reoccurring under appropriate meteorological conditions.

  6. Post-fire stand structure impacts carbon storage within Siberian larch forests

    Science.gov (United States)

    Alexander, H. D.; Natali, S.; Loranty, M. M.; Mack, M. C.; Davydov, S. P.; Zimov, N.

    2015-12-01

    Increased fire severity within boreal forests of the Siberian Arctic has the potential to alter forest stand development thereby altering carbon (C) accumulation rates and storage during the post-fire successional interval. One potential change is increased stand density, which may result from fire consumption of the soil organic layer and changes to the seedbed that favor germination and establishment of larch trees during early succession. In this study, we evaluated above- and belowground C pools across 12 stands of varying tree density within a single 75-year old fire scar located near Cherskii, Sakha Republic, Russia. In each stand, we inventoried the size and density of larch trees and large shrubs (Salix and Betula spp.), and in combination with with allometric equations, estimated aboveground contribution to C pools. We quantified woody debris C pools using the line intercept method. We sampled belowground C pools in the soil organic layer + upper (0-10 cm) mineral soil and coarse roots (> 2 mm diameter) using sediment cores and 0.25 x 0.25-m trenches, respectively. We found that high density stands store ~ 20% more C (~7,500 g C m-2) than low density stands (~5,800 g C m-2). In high density stands, about 35% more C is stored aboveground within live larch trees (1650 g C m-2) compared to low density stands (940 g C m-2), and about 15% more C is stored in the soil organic layer and upper mineral soil. Coarse root C was 20% higher in high density stands (~475 g C m-2) compared to those with low density (~350 g C m-2). Less C was stored in large shrubs in high density stands, both in aboveground portions and coarse roots, but these amounts were relatively small (increase C storage, leading to a negative feedback to climate, but the combined effects of density on C dynamics, summer and winter albedo, and future fire regimes will interact to determine the magnitude of any vegetation-climate feedbacks.

  7. Thaw pond dynamics and carbon emissions in a Siberian lowland tundra landscape

    Science.gov (United States)

    van Huissteden, Ko; Heijmans, Monique; Dean, Josh; Meisel, Ove; Goovaerts, Arne; Parmentier, Frans-Jan; Schaepman-Strub, Gabriela; Belelli Marchesini, Luca; Kononov, Alexander; Maximov, Trofim; Borges, Alberto; Bouillon, Steven

    2017-04-01

    Arctic climate change induces drastic changes in permafrost surface wetness. As a result of thawing ground ice bodies, ice wedge troughs and thaw ponds are formed. Alternatively, ongoing thaw may enhance drainage as a result of increased interconnectedness of thawing ice wedge troughs, as inferred from a model study (Liljedahl et al., 2016, Nature Geoscience, DOI: 10.1038/NGEO2674). However, a recent review highlighted the limited predictability of consequences of thawing permafrost on hydrology (Walvoord and Kurylyk, 2016, Vadose Zone J., DOI:10.2136/vzj2016.01.0010). Overall, these changes in tundra wetness modify carbon cycling in the Arctic and in particular the emissions of CO2 and CH4 to the atmosphere, providing a possibly positive feedback on climate change. Here we present the results of a combined remote sensing, geomorphological, vegetation and biogechemical study of thaw ponds in Arctic Siberian tundra, at Kytalyk research station near Chokurdakh, Indigirka lowlands. The station is located in an area dominated by Pleistocene ice-rich 'yedoma' sediments and drained thaw lake bottoms of Holocene age. The development of three types of ponds in the Kytalyk area (polygon centre ponds, ice wedge troughs and thaw ponds) has been traced with high resolution satellite and aerial imagery. The remote sensing data show net areal expansion of all types of ponds. Next to formation of new ponds, local vegetation change from dry vegetation types to wet, sedge-dominated vegetation is common. Thawing ice wedges and thaw ponds show an increase in area and number at most studied locations. In particular the area of polygon centre ponds increased strongly between 2010 and 2015, but this is highly sensitive to antecedent precipitation conditions. Despite a nearly 60% increase of the area of thawing ice wedge troughs, there is no evidence of decreasing water surfaces by increasing drainage through connected ice wedge troughs. The number of thaw ponds shows an equilibrium

  8. Variability in above- and belowground carbon stocks in a Siberian larch watershed

    Science.gov (United States)

    Webb, Elizabeth E.; Heard, Kathryn; Natali, Susan M.; Bunn, Andrew G.; Alexander, Heather D.; Berner, Logan T.; Kholodov, Alexander; Loranty, Michael M.; Schade, John D.; Spektor, Valentin; Zimov, Nikita

    2017-09-01

    Permafrost soils store between 1330 and 1580 Pg carbon (C), which is 3 times the amount of C in global vegetation, almost twice the amount of C in the atmosphere, and half of the global soil organic C pool. Despite the massive amount of C in permafrost, estimates of soil C storage in the high-latitude permafrost region are highly uncertain, primarily due to undersampling at all spatial scales; circumpolar soil C estimates lack sufficient continental spatial diversity, regional intensity, and replication at the field-site level. Siberian forests are particularly undersampled, yet the larch forests that dominate this region may store more than twice as much soil C as all other boreal forest types in the continuous permafrost zone combined. Here we present above- and belowground C stocks from 20 sites representing a gradient of stand age and structure in a larch watershed of the Kolyma River, near Chersky, Sakha Republic, Russia. We found that the majority of C stored in the top 1 m of the watershed was stored belowground (92 %), with 19 % in the top 10 cm of soil and 40 % in the top 30 cm. Carbon was more variable in surface soils (10 cm; coefficient of variation (CV) = 0.35 between stands) than in the top 30 cm (CV = 0.14) or soil profile to 1 m (CV = 0.20). Combined active-layer and deep frozen deposits (surface - 15 m) contained 205 kg C m-2 (yedoma, non-ice wedge) and 331 kg C m-2 (alas), which, even when accounting for landscape-level ice content, is an order of magnitude more C than that stored in the top meter of soil and 2 orders of magnitude more C than in aboveground biomass. Aboveground biomass was composed of primarily larch (53 %) but also included understory vegetation (30 %), woody debris (11 %) and snag (6 %) biomass. While aboveground biomass contained relatively little (8 %) of the C stocks in the watershed, aboveground processes were linked to thaw depth and belowground C storage. Thaw depth was negatively related to stand age, and soil C density

  9. Measurements of trace gas species and aerosols at three Siberian stations

    Science.gov (United States)

    Arshinov, Mikhail Yu.; Belan, Boris D.; Davydov, Denis K.; Kozlov, Artem V.; Ivlev, Georgii A.; Pestunov, Dmitrii A.; Tolmachev, Gennadii N.; Fofonov, Alexander V.

    2014-05-01

    Siberia is of great importance to understand the climate change due to it covers about 10% of Earth's land surface and it has the largest area to be studied under the Pan-Eurasian Experiment (PEEX). In the overview done by Kulmala et al. (2011) authors arrived at a conclusion that continuous and comprehensive measurements of GHGs and aerosols over Siberia are still lacking. Understanding the importance of this problem, in recent years the Institute of Atmospheric Optics SB RAS established several monitoring stations for continuous measurements of aerosol and trace gas species to fill up this gap. In this paper we present some results of continuous measurements of trace gas species and aerosols carried out at three stations located in West Siberia. The first one is a so-called TOR-station located in the scientific campus of Tomsk (56° 28'41"N, 85° 03'15"E), the second one is the Base Experimental Complex (BEC, 56° 28'49"N, 85° 06'08"E) - in the eastern suburbs of Tomsk, and the third one is Fonovaya Observatory (56° 25'07"N, 84° 04'27"E) - in a rural area 60 km west of Tomsk. All equipment of the stations is fully automated and can be monitored via Internet. Gas analyzers are hourly calibrated against standard gas mixtures, micro-flux gas sources, or gas generators, depending on the instrument type and the gas to be detected. Aerosol measurements carried out continuously from March 2010 enabled a frequency and seasonal dependency of the new particle formation (NPF) events to be revealed. NPF events in Siberia are more often observed during spring (from March to May) and early autumn (secondary frequency peak in September). On average, NPF evens took place on 23-28 % of all days. This work was funded by Presidium of RAS (Program No. 4), Brunch of Geology, Geophysics and Mining Sciences of RAS (Program No. 5), Interdisciplinary integration projects of Siberian Branch of RAS (No. 35, No. 70, No. 131), Russian Foundation for Basic Research (grants No 14

  10. Trace element transport in western Siberian rivers across a permafrost gradient

    Science.gov (United States)

    Pokrovsky, Oleg S.; Manasypov, Rinat M.; Loiko, Sergey V.; Krickov, Ivan A.; Kopysov, Sergey G.; Kolesnichenko, Larisa G.; Vorobyev, Sergey N.; Kirpotin, Sergey N.

    2016-03-01

    Towards a better understanding of trace element (TE) transport in permafrost-affected Earth surface environments, we sampled ˜ 60 large and small rivers ( bogs > forest. The lakes decreased export of Mn and Co in summer and Ni, Cu, and Rb in spring, presumably due to biotic processes. The lakes enriched the rivers in insoluble lithogenic elements in summer and winter, likely due to TE mobilization from unfrozen mineral sediments. The rank of environmental factors on TE concentration in western Siberian rivers was latitude (three permafrost zones) > season > watershed size. The effect of the latitude was minimal in spring for most TEs but highly visible for Sr, Mo, Sb and U. The main factors controlling the shift of river feeding from surface and subsurface flow to deep underground flow in the permafrost-bearing zone were the depth of the active (unfrozen) seasonal layer and its position in organic or mineral horizons of the soil profile. In the permafrost-free zone, the relative role of carbonate mineral-bearing base rock feeding versus bog water feeding determined the pattern of TE concentration and fluxes in rivers of various sizes as a function of season. Comparison of obtained TE fluxes in WSL rivers with those of other subarctic rivers demonstrated reasonable agreement for most TEs; the lithology of base rocks was the major factor controlling the magnitude of TE fluxes. Climate change in western Siberia and permafrost boundary migration will essentially affect the elements controlled by underground water feeding (DIC, alkaline earth elements (Ca, Sr), oxyanions (Mo, Sb, As) and U). The thickening of the active layer may increase the export of trivalent and tetravalent hydrolysates in the form of organo-ferric colloids. Plant litter-originated divalent metals present as organic complexes may be retained via adsorption on mineral horizon. However, due to various counterbalanced processes controlling element source and sinks in plant-peat-mineral soil

  11. A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin

    Science.gov (United States)

    Archer, D.

    2014-06-01

    A two-dimensional model of a passive continental margin was adapted to the simulation of the methane cycle on Siberian continental shelf and slope, attempting to account for the impacts of glacial/interglacial cycles in sea level, alternately exposing the continental shelf to freezing conditions with deep permafrost formation during glacial times, and immersion in the ocean in interglacial times. The model is used to gauge the impact of the glacial cycles, and potential anthropogenic warming in the deep future, on the atmospheric methane emission flux, and the sensitivities of that flux to processes such as permafrost formation and terrestrial organic carbon (Yedoma) deposition. Hydrological forcing drives a freshening and ventilation of pore waters in areas exposed to the atmosphere, which is not quickly reversed by invasion of seawater upon submergence, since there is no analogous saltwater pump. This hydrological pump changes the salinity enough to affect the stability of permafrost and methane hydrates on the shelf. Permafrost formation inhibits bubble transport through the sediment column, by construction in the model. The impact of permafrost on the methane budget is to replace the bubble flux by offshore groundwater flow containing dissolved methane, rather than accumulating methane for catastrophic release when the permafrost seal fails during warming. By far the largest impact of the glacial/interglacial cycles on the atmospheric methane flux is attenuation by dissolution of bubbles in the ocean when sea level is high. Methane emissions are highest during the regression (soil freezing) part of the cycle, rather than during transgression (thawing). The model-predicted methane flux to the atmosphere in response to a warming climate is small, relative to the global methane production rate, because of the ongoing flooding of the continental shelf. A slight increase due to warming could be completely counteracted by sea level rise on geologic time scales

  12. Variability in above- and belowground carbon stocks in a Siberian larch watershed

    Directory of Open Access Journals (Sweden)

    E. E. Webb

    2017-09-01

    Full Text Available Permafrost soils store between 1330 and 1580 Pg carbon (C, which is 3 times the amount of C in global vegetation, almost twice the amount of C in the atmosphere, and half of the global soil organic C pool. Despite the massive amount of C in permafrost, estimates of soil C storage in the high-latitude permafrost region are highly uncertain, primarily due to undersampling at all spatial scales; circumpolar soil C estimates lack sufficient continental spatial diversity, regional intensity, and replication at the field-site level. Siberian forests are particularly undersampled, yet the larch forests that dominate this region may store more than twice as much soil C as all other boreal forest types in the continuous permafrost zone combined. Here we present above- and belowground C stocks from 20 sites representing a gradient of stand age and structure in a larch watershed of the Kolyma River, near Chersky, Sakha Republic, Russia. We found that the majority of C stored in the top 1 m of the watershed was stored belowground (92 %, with 19 % in the top 10 cm of soil and 40 % in the top 30 cm. Carbon was more variable in surface soils (10 cm; coefficient of variation (CV  =  0.35 between stands than in the top 30 cm (CV  =  0.14 or soil profile to 1 m (CV  =  0.20. Combined active-layer and deep frozen deposits (surface – 15 m contained 205 kg C m−2 (yedoma, non-ice wedge and 331 kg C m−2 (alas, which, even when accounting for landscape-level ice content, is an order of magnitude more C than that stored in the top meter of soil and 2 orders of magnitude more C than in aboveground biomass. Aboveground biomass was composed of primarily larch (53 % but also included understory vegetation (30 %, woody debris (11 % and snag (6 % biomass. While aboveground biomass contained relatively little (8 % of the C stocks in the watershed, aboveground processes were linked to thaw depth and

  13. Verifying the mesozoic dipole low hypothesis by the Siberian trap data

    Science.gov (United States)

    Shcherbakova, V. V.; Zhidkov, G. V.; Shcherbakov, V. P.; Latyshev, A. V.; Fetisova, A. M.

    2015-05-01

    A complex study is carried out for the collection of trap rocks sampled from two sequences in the geographically distant regions of the Siberian trap province: the Ergalakh section (Norilsk region) and Tyvankitskii and Delkanskii formations (Maymecha-Kotuy region). The magnetic and thermomagnetic properties are studied, petrographic and microscopic investigations are carried out, the paleointensities are determined, and the domain structure of ferromagnetics is assessed using the Day diagram and the thermomagnetic criterion. It is shown that small single-domain and/or pseudo-single-domain grains are the carriers of remanent magnetization. The absolute paleointensities H anc are determined by the Thellier-Coe method with test heating of the samples to lower temperatures (check-point procedure). The paleointensity estimates that meet the modern reliability criteria are obtained in more than 130 samples. The mean H anc values in the lava flows from the Ergalakh section and the TyvankittskiiFormation, as well as in samples from the Delkanskii Formation, vary within 2.1-24.6 mkT, which is considerably lower than the present magnetic field at the sampling site (˜ 50 mkT). The corresponding mean VDM values in these sites vary within (0.54-3.2) × 1022 Am2 (with a dispersion of ˜0.9 × 1022 Am2), which is far lower than the mean VDM value (˜8 × 1022 Am2) in the Late Cenozoic. The agreement of low H anc and VDM determined in the Ergalakh section, Tyvankitskii, and Delkanskii formations with the previous similar data on the traps (Solodovnikov, 1994; Heunemann et al., 2004; Shcherbakova et al., 2005; 2013) supports the Mesozoic Dipole Low (MDL) hypothesis. In the Ergalakh section, low and extremely low H anc (11.2 and 2.7 mkT) are determined in two pulses (five flows) of the Ivakinskii Formation, which precedes the geomagnetic reversal. This probably indicates that these flows recorded a sharp decrease in H anc prior to the geomagnetic reversal (or at its beginning

  14. Wildfire smoke in the Siberian Arctic in summer: source characterization and plume evolution from airborne measurements

    Directory of Open Access Journals (Sweden)

    P. Ciais

    2009-12-01

    Full Text Available We present airborne measurements of carbon dioxide (CO2, carbon monoxide (CO, ozone (O3, equivalent black carbon (EBC and ultra fine particles over North-Eastern Siberia in July 2008 performed during the YAK-AEROSIB/POLARCAT experiment. During a "golden day" (11 July 2008 a number of biomass burning plumes were encountered with CO mixing ratio enhancements of up to 500 ppb relative to a background of 90 ppb. Number concentrations of aerosols in the size range 3.5–200 nm peaked at 4000 cm−3 and the EBC content reached 1.4 μg m−3. These high concentrations were caused by forest fires in the vicinity of the landing airport in Yakutsk where measurements in fresh smoke could be made during the descent. We estimate a combustion efficiency of 90 ± 3% based on CO and CO2 measurements and a CO emission factor of 65.5 ± 10.8 g CO per kilogram of dry matter burned. This suggests a potential increase in the average northern hemispheric CO mixing ratio of 3.0–7.2 ppb per million hectares of Siberian forest burned. For BC, we estimate an emission factor of 0.52 ± 0.07 g BC kg−1, comparable to values reported in the literature. The emission ratio of ultra-fine particles (3.5–200 nm was 26 cm−3 (ppb CO−1, consistent with other airborne studies.

    The transport of identified biomass burning plumes was investigated using the FLEXPART Lagrangian model. Based on sampling of wildfire plumes from the same source but with different atmospheric ages derived from FLEXPART, we estimate that the e-folding lifetimes of EBC and ultra fine particles (between 3.5 and 200 nm in size against removal and growth processes are 5.1 and 5.5 days respectively, supporting lifetime estimates used in various modelling studies.

  15. A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin

    Directory of Open Access Journals (Sweden)

    D. Archer

    2014-06-01

    Full Text Available A two-dimensional model of a passive continental margin was adapted to the simulation of the methane cycle on Siberian continental shelf and slope, attempting to account for the impacts of glacial/interglacial cycles in sea level, alternately exposing the continental shelf to freezing conditions with deep permafrost formation during glacial times, and immersion in the ocean in interglacial times. The model is used to gauge the impact of the glacial cycles, and potential anthropogenic warming in the deep future, on the atmospheric methane emission flux, and the sensitivities of that flux to processes such as permafrost formation and terrestrial organic carbon (Yedoma deposition. Hydrological forcing drives a freshening and ventilation of pore waters in areas exposed to the atmosphere, which is not quickly reversed by invasion of seawater upon submergence, since there is no analogous saltwater pump. This hydrological pump changes the salinity enough to affect the stability of permafrost and methane hydrates on the shelf. Permafrost formation inhibits bubble transport through the sediment column, by construction in the model. The impact of permafrost on the methane budget is to replace the bubble flux by offshore groundwater flow containing dissolved methane, rather than accumulating methane for catastrophic release when the permafrost seal fails during warming. By far the largest impact of the glacial/interglacial cycles on the atmospheric methane flux is attenuation by dissolution of bubbles in the ocean when sea level is high. Methane emissions are highest during the regression (soil freezing part of the cycle, rather than during transgression (thawing. The model-predicted methane flux to the atmosphere in response to a warming climate is small, relative to the global methane production rate, because of the ongoing flooding of the continental shelf. A slight increase due to warming could be completely counteracted by sea level rise on geologic

  16. The role of summer precipitation and summer temperature in establishment and growth of dwarf shrub Betula nana in northeast Siberian tundra

    DEFF Research Database (Denmark)

    Li, Bingxi; Heijmans, Monique M P D; Berendse, Frank;

    2016-01-01

    It is widely believed that deciduous tundra-shrub dominance is increasing in the pan-Arctic region, mainly due to rising temperature. We sampled dwarf birch (Betula nana L.) at a northeastern Siberian tundra site and used dendrochronological methods to explore the relationship between climatic...

  17. The Potential Impact of CO2 and Air Temperature Increases on Krummholz's Transformation into Arborescent Form in the Southern Siberian Mountains

    Science.gov (United States)

    Kharuk, V. I.; Dvinskaya, M. L.; Im, S. T.; Ranson, K. J.

    2011-01-01

    Trees in the southern Siberian Mountains forest-tundra ecotone have considerably increased their radial and apical growth increments during the last few decades. This leads to the widespread vertical transformation of mat and prostrate krummholz forms of larch (Larix sibirica Ledeb) and Siberian pine (Pinus sibirica Du Tour). An analysis of the radial growth increments showed that these transformations began in the mid-1980s. Larch showed a greater resistance to the harsh alpine environment and attained a vertical growth form in areas where Siberian pine is still krummholz. Upper larch treeline is about 10 m higher than Siberian pine treeline. Observed apical and radial growth increment increases were correlated with CO2 concentration (r = 0.83-0.87), summer temperatures (r = 0.55-0.64), and "cold period" (i.e. September-May) air temperatures (r = 0.36-0.37). Positive correlation between growth increments and winter precipitation was attributed to snow cover protection for trees during wintertime.

  18. Effects of 60 Hz Magnetic Field Exposure on the Pineal and Hypothalamic-Pituitary-Gonadal Axis in the Siberian Hamster (Phodopus Sungorus)

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Bary W.(BATTELLE (PACIFIC NW LAB)); Matt, Kathleen S.(Arizona State University); Morris, James E.(BATTELLE (PACIFIC NW LAB)); Sasser, Lyle B.(BATTELLE (PACIFIC NW LAB)); Miller, Douglas L.(BATTELLE (PACIFIC NW LAB)); Anderson, Larry E.(BATTELLE (PACIFIC NW LAB))

    1999-11-15

    Experiments using the dwarf Siberian hamster Phodopus sungorus were carried out to determine possible neuroendocrine consequences of one-time and repeated exposures to 60 Hz magnetic fields (MF). Animals were maintained in either a short-light (SL, 8 h light:16 h dar) or long-light (LL, 16 h light:8h dark) photoperiod.

  19. Assessment of undiscovered continuous oil and shale-gas resources in the Bazhenov Formation of the West Siberian Basin Province, Russia, 2016

    Science.gov (United States)

    Klett, Timothy R.; Schenk, Christopher J.; Brownfield, Michael E.; Leathers-Miller, Heidi M.; Mercier, Tracey J.; Pitman, Janet K.; Tennyson, Marilyn E.

    2016-11-10

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean continuous resources of 12 billion barrels of oil and 75 trillion cubic feet of gas in the Bazhenov Formation of the West Siberian Basin Province, Russia.

  20. The role of summer precipitation and summer temperature in establishment and growth of dwarf shrub Betula nana in northeast Siberian tundra

    NARCIS (Netherlands)

    Bingxi Li,; Heijmans, M.M.P.D.; Berendse, F.; Blok, D.; Maximov, T.; Sass-Klaassen, U.G.W.

    2016-01-01

    It is widely believed that deciduous tundrashrub
    dominance is increasing in the pan-Arctic region,
    mainly due to rising temperature. We sampled dwarf birch
    (Betula nana L.) at a northeastern Siberian tundra site and
    used dendrochronological methods to explore the relationship
    bet

  1. Complete Genome Sequence of Phodopus sungorus Papillomavirus Type 1 (PsPV1), a Novel Member of the Pipapillomavirus Genus, Isolated from a Siberian Hamster.

    Science.gov (United States)

    Kocjan, Boštjan J; Hošnjak, Lea; Račnik, Joško; Zadravec, Marko; Poljak, Mario

    2014-04-10

    We report the complete genomic sequence of Phodopus sungorus papillomavirus type 1 (PsPV1), isolated from an anogenital lesion of a Siberian hamster. PsPV1 is taxonomically classified in the genus Pipapillomavirus and is most closely related to Mesocricetus auratus papillomavirus 1 (MaPV1).

  2. Ovarian matrix metalloproteinases are differentially regulated during the estrous cycle but not during short photoperiod induced regression in Siberian hamsters (Phodopus sungorus

    Directory of Open Access Journals (Sweden)

    Vrooman Lisa A

    2010-06-01

    Full Text Available Abstract Background Matrix metalloproteinases (MMPs are implicated as mediators for ovarian remodeling events, and are involved with ovarian recrudescence during seasonal breeding cycles in Siberian hamsters. However, involvement of these proteases as the photoinhibited ovary undergoes atrophy and regression had not been assessed. We hypothesized that 1 MMPs and their tissue inhibitors, the TIMPs would be present and differentially regulated during the normal estrous cycle in Siberian hamsters, and that 2 MMP/TIMP mRNA and protein levels would increase as inhibitory photoperiod induced ovarian degeneration. Methods MMP-2, -9, -14 and TIMP-1 and -2 mRNA and protein were examined in the stages of estrous (proestrus [P], estrus [E], diestrus I [DI], and diestrus II [DII] in Siberian hamsters, as well as after exposure to 3, 6, 9, and 12 weeks of inhibitory short photoperiod (SD. Results MMP-9 exhibited a 1.6-1.8 fold decrease in mRNA expression in DII (p Conclusions Although MMPs appear to be involved in the normal ovarian estrus cycle at the protein level in hamsters, those examined in the present study are unlikely to be key players in the slow atrophy of tissue as seen in Siberian hamster ovarian regression.

  3. Weak population structure in European roe deer (Capreolus capreolus and evidence of introgressive hybridization with Siberian roe deer (C. pygargus in northeastern Poland.

    Directory of Open Access Journals (Sweden)

    Juanita Olano-Marin

    Full Text Available We investigated contemporary and historical influences on the pattern of genetic diversity of European roe deer (Capreolus capreolus. The study was conducted in northeastern Poland, a zone where vast areas of primeval forests are conserved and where the European roe deer was never driven to extinction. A total of 319 unique samples collected in three sampling areas were genotyped at 16 microsatellites and one fragment (610 bp of mitochondrial DNA (mtDNA control region. Genetic diversity was high, and a low degree of genetic differentiation among sampling areas was observed with both microsatellites and mtDNA. No evidence of genetic differentiation between roe deer inhabiting open fields and forested areas was found, indicating that the ability of the species to exploit these contrasting environments might be the result of its phenotypic plasticity. Half of the studied individuals carried an mtDNA haplotype that did not belong to C. capreolus, but to a related species that does not occur naturally in the area, the Siberian roe deer (C. pygargus. No differentiation between individuals with Siberian and European mtDNA haplotypes was detected at microsatellite loci. Introgression of mtDNA of Siberian roe deer into the genome of European roe deer has recently been detected in eastern Europe. Such introgression might be caused by human-mediated translocations of Siberian roe deer within the range of European roe deer or by natural hybridization between these species in the past.

  4. Methane oxidation associated to submerged brown-mosses buffers methane emissions from Siberian polygonal peatlands

    Science.gov (United States)

    Liebner, Susanne; Zeyer, Josef; Knoblauch, Christian

    2010-05-01

    Circumpolar peatlands store roughly 18 % of the globally stored carbon in soils [based on 1, 2]. Also, northern wetlands and tundra are a net source of methane (CH4), an effective greenhouse gas (GHG), with an estimated annual CH4 release of 7.2% [3] or 8.1% [4] of the global total CH4 emission. Although it is definite that Arctic tundra significantly contributes to the global methane emissions in general, regional variations in GHG fluxes are enormous. CH4 fluxes of polygonal tundra within the Siberian Lena Delta, for example, were reported to be low [5, 6], particularly at open water polygonal ponds and small lakes [7] which make up around 10 % of the delta's surface. Low methane emissions from polygonal ponds oppose that Arctic permafrost thaw ponds are generally known to emit large amounts of CH4 [8]. Combining tools of biogeochemistry and molecular microbiology, we identified sinks of CH4 in polygonal ponds from the Lena Delta that were not considered so far in GHG studies from Arctic wetlands. Pore water CH4 profiling in polygonal ponds on Samoylov, a small island in the central part of the Lena Delta, revealed a pronounced zone of CH4 oxidation near the vegetation surface in submerged layers of brown-mosses. Here, potential CH4 oxidation was an order of magnitude higher than in non-submerged mosses and in adjacent bulk soil. We could additionally show that this moss associated methane oxidation (MAMO) is hampered when exposure of light is prevented. Shading of plots with submerged Scorpidium scorpioides inhibited MAMO leading to higher CH4 concentrations and an increase in CH4 fluxes by a factor of ~13. Compared to non-submerged mosses, the submerged mosses also showed significantly lower δ13C values indicating that they use carbon dioxide derived from methane oxidation for photosynthesis. Applying stable isotope probing of DNA, type II methanotrophs were identified to be responsible for the oxidation of CH4 in the submerged Scorpidium scorpioides. Our

  5. Triggers of Permo-Triassic boundary mass extinction in South China: The Siberian Traps or Paleo-Tethys ignimbrite flare-up?

    Science.gov (United States)

    He, Bin; Zhong, Yu-Ting; Xu, Yi-Gang; Li, Xian-Hua

    2014-09-01

    Assessment of the synchroneity between the Siberian Traps and the Permo-Triassic boundary (PTB) mass extinction has led to the proposition that the Siberian flood volcanism was responsible for the severest biotic crisis in the Phanerozoic. However, recent studies suggest that the Siberian Traps may have postdated the main extinction horizon. In this paper, we demonstrate, using stratigraphy, a time and intensity coincidence between PTB volcanic ash and the main extinction horizon. Geochemistry of the PTB volcanic ashes in five sections in South China indicates that they were derived from continental magmatic arc. Zircons extracted from the PTB volcanic ashes have negative εHf(t) (- 12.9 to - 2.0) and δ18O (6.8 to 10.9‰), consistent with an acidic volcanism and a crustal-derived origin, and therefore exclude a genetic link between the PTB mass extinction and the Siberian Traps. On the basis of spatial variation in the number of the PTB volcanic ash layers and the thickness of the ash layers in South China, we propose that the PTB volcanic ash may be related to Paleo-Tethys continental arc magmatism in the Kunlun area. Ignimbrite flare-up related to rapid plate subduction during the final assemblage of the Pangea super-continent may have generated a volcanic winter, which eventually triggered the collapse of ecosystem and ultimately mass extinction at the end of the Permian. The Siberian Traps may have been responsible for a greenhouse effect and so have been responsible for both a second pulse of the extinction event and Early Triassic ecological evolution.

  6. Winter temperatures over the Korean Peninsula and East Asia: development of a new index and its application to seasonal forecast

    Science.gov (United States)

    Kim, Seon Tae; Sohn, Soo-Jin; Kug, Jong-Seong

    2017-09-01

    This study proposes a new index for monitoring and predicting winter temperatures of the Korean Peninsula based on the dominant atmospheric winter teleconnection patterns. The utilization of this index is further extended to the East Asian Winter Monsoon (EAWM) index because the new index is found to well represent the main feature of the EAWM circulation. Among the teleconnection patterns, the East Atlantic (EA) and Western Pacific (WP) patterns are found to be most strongly correlated with winter temperatures via their partial association with changes in sea level pressure (SLP) around the Korean Peninsula, i.e., the EA and WP patterns are associated with SLP variation over the Siberian High region and the Kuroshio extension region to the east of Japan, respectively. On the basis of this relationship, the two regions representing the northwest-to-southeast SLP gradients are determined to define the new index. It is found that the new index can represent the Korean winter temperatures consistently well regardless of their considerable decadal changes. When compared with the existing SLP-based EAWM indices, the new index shows the best performance in delineating winter air temperatures, not only in the Korean Peninsula but also in the entire East Asian region. We also assess the prediction skill of the new index with seasonal coupled forecast models of the APEC Climate Center of Korea and its capability to predict winter temperatures. This assessment shows that the new index has potential for operationally predicting and monitoring winter temperatures in Korea and the whole of East Asia.

  7. Petrogenesis and timing of mafic magmatism, South Taimyr, Arctic Siberia: A northerly continuation of the Siberian Traps?

    Science.gov (United States)

    Reichow, M. K.; Saunders, A. D.; Scott, R. A.; Millar, I. L.; Barfod, D.; Pringle, M. S.; Rogers, N. W.; Hammond, S.

    2016-04-01

    The Siberian large igneous province (LIP) forms the world's most extensive continental exposure of basalt and has several sub-provinces surrounding it, which may be genetically related. The Taimyr peninsula of north Siberia is one of these sub-provinces and is frequently assumed to be the northerly continuation of the basalts exposed at Noril'sk, the best-studied area of the Siberian LIP. However, the correlation is uncertain. We present new major and trace element data from 35 samples of extrusive and intrusive rocks from Taimyr, with Sr and Nd isotope data from a subset of ten. The Taimyr rocks fall into two groups with low (~ 7 wt.%) and elevated (~ 9 wt.%) MgO concentrations. The high-MgO rocks display a restricted range of initial 87Sr/86Sr (0.705 to 0.706) and 143Nd/144Nd (0.5122 to 0.5124) ratios, and share bulk silicate earth normalised rare earth element patterns strikingly similar to data observed in the ore-related Noril'sk intrusions. The remaining low-MgO group samples have a broader range with higher Sr and lower Nd isotope values and higher incompatible trace element ratios (e.g., Th/Ta > 5.3 and La/Smn > 1.7) similar to the crustally-contaminated Nadezhdinsky and Morongovsky suite basalts of the Noril'sk region. The major and trace element data for both groups are consistent with a process of fractional crystallisation coupled with small degrees of assimilation of incompatible-element-enriched lower crust involving different contaminants. Trace element model calculations indicate a process of magma formation at large degrees of partial melting and at pressures of less than 3 GPa, probably within the garnet-spinel transition zone or the spinel stability field of the asthenospheric mantle. We obtained an argon plateau age of ~ 252 (252.7 ± 1.5) Ma and a ~ 239 Ma total fusion age from a Taimyr lava and intrusive sample, respectively, confirming that volcanism is only partly contemporaneous with the activity of the Siberian LIP. Although this is in

  8. Re-Os isotope measurements of single sulfide inclusions in a Siberian diamond and its nitrogen aggregation systematics

    Science.gov (United States)

    Pearson, D. G.; Shirey, S. B.; Bulanova, G. P.; Carlson, R. W.; Milledge, H. J.

    1999-03-01

    We have measured the Re-Os isotopic compositions of individual syngenetic sulfide inclusions from three different growth zones within a central cross section plate cut from a single Siberian diamond. Individual sulfides in their diamond host were isolated by laser cutting. The sulfides, and hence the different growth zones of the diamond have been suggested to differ in age by up to 2 Ga on the basis of their Pb isotope compositions. Re-Os model ages of the four inclusions range from 3.1 ± 0.3 to 3.5 ± 0.3 Ga and suggest a Middle Archaean age for the diamond. A sulfide inclusion in the rim of the diamond is very different in elemental composition from those of the core and intermediate zones. It is enriched in Os, Re, Pb, and Zn and has more radiogenic Os and Pb isotopes. The inclusion is connected to the surface of the diamond by a healed crack, revealed by cathodoluminescence. The compositional distinction may be caused either by postformational interaction between an ancient sulfide and a fluid, possibly at the time of kimberlite eruption, or later stage growth of new diamond plus sulfide. Such chemical complexities, and the presence of healed fractures within the host diamond, emphasize the desirability of analyzing individual inclusions from well-characterized diamonds if isotope data for inclusions are to be better understood. Nitrogen contents and aggregation state in the core and intermediate zone of the host diamond closely approximate theoretically calculated isotherms based on consideration of experimentally determined nitrogen aggregation kinetics. The nitrogen content of the rim diamond is too low to obtain spectra that allow accurate deconvolution of relative aggregation levels for use in residence time calculations. The aggregation state of nitrogen in the core and intermediate growth zones is compatible with a long, ca. 3 Ga mantle residence time at normal lithospheric temperatures. The similarity of the sulfide inclusion Re-Os model ages to the

  9. Evaluation of oral and subcutaneous delivery of an experimental canarypox recombinant canine distemper vaccine in the Siberian polecate (Mustela eversmanni)

    Science.gov (United States)

    Wimsatt, Jeffrey; Biggins, Dean E.; Innes, Kim; Taylor, Bobbi; Garell, Della

    2003-01-01

    We assessed the safety and efficacy of an experimental canarypox-vectored recombinant canine distemper virus (CDV) subunit vaccine in the Siberian polecat (Mustela eversmanni), a close relative of the black-footed ferret, (M. nigripes), an endangered species that is highly susceptible to the virus. Siberian polecats were randomized into six treatment groups. Recombinant canine distemper vaccine was administered s.c. at three dose levels (104.5, 105.0, and 105.5 plaque-forming units [PFU] per dose) and was administered orally by spraying the vaccine into the oropharnyx at two dose levels (105.5, 108.0 PFU per dose). The sixth group of control animals was not vaccinated. For both routes of administration, two 1-ml doses of reconstituted vaccine were delivered 4 wk apart, followed by live virus challenge 3 wk after the second vaccination. During the challenge, Synder Hill test strain CDV obtained from the National Veterinary Services Laboratory in Ames, Iowa, was administered i.p. Serial blood samples for CDV serology were collected immediately before vaccination and challenge, and 10, 15, and 20 days after challenge. Clinical signs and body weights were recorded up to 32 days after challenge. The survival rate in animals receiving vaccine at the highest oral dose (108.0 PFU per dose) was 83.3%. Survival rate was 50.0% in the high s.c. and 60.0% in the medium s.c. groups. All animals in the low–s.c. dose, low–oral dose, and control groups died after exposure. Vaccine dose overall (oral and s.c.) and dose in response to s.c. administration when considered alone were significant predictors of survival (P = 0.006 and P = 0.04, respectively). Among the polecats challenged with virulent virus, those that died became sick sooner than those that survived. Animals that died lost significantly more weight during the 10 days after challenge than did animals that survived (P = 0.02). Survival rates did not differ by sex, founder female status, or breeding pedigree in any of

  10. East of Eden / M. A.

    Index Scriptorium Estoniae

    M. A.

    2005-01-01

    Palmses toimub sel nädalal rahvusvahelise stsenaariumikoolituse East of Eden seminar. Koolituse koordinatsioonikeskus tegutseb alates 2005.aastast Eesti Filmi Sihtasutuse juures, Eesti--poolseks koordinaatoriks Anu Ernits

  11. Discourse Between East and West

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The first Chinese-hosted cultural dialogue between the East and the West was held in Nishan, Shandong Province The first Nishan Forum on World Civilizations kicked off on September 26 at Nishan Mountain, 25 km southeast

  12. East of Eden / M. A.

    Index Scriptorium Estoniae

    M. A.

    2005-01-01

    Palmses toimub sel nädalal rahvusvahelise stsenaariumikoolituse East of Eden seminar. Koolituse koordinatsioonikeskus tegutseb alates 2005.aastast Eesti Filmi Sihtasutuse juures, Eesti--poolseks koordinaatoriks Anu Ernits

  13. East India Company Logbooks - Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection consists of images of 1,235 ship logbooks created during British East India Company voyages. Period of record 1786-1834, peaking in 1804. The...

  14. Fire Effects on Microbial Enzyme Activities in Larch Forests of the Siberian Arctic

    Science.gov (United States)

    Ludwig, S.; Alexander, H. D.; Bulygina, E. B.; Mann, P. J.; Natali, S.

    2012-12-01

    Arctic forest ecosystems are warming at an accelerated rate relative to lower latitudes, with global implications for C cycling within these regions. As climate continues to warm and dry, wildfire frequency and severity are predicted to increase, creating a positive feedback to climate warming. Increased fire activity will also influence the microenvironment experienced by soil microbes in disturbed soils. Because soil microbes regulate carbon (C) and nitrogen (N) cycling between terrestrial ecosystems and the atmosphere, it is important to understand microbial response to fires, particularly in the understudied larch forests in the Siberian Arctic. In this project, we created experimental burn plots in a mature larch forest in the Kolyma River watershed of Northeastern Siberia. Plots were burned at several treatments: control (no burn), low, moderate, and severe. After, 1 and 8 d post-fire, we measured soil organic layer depth, soil organic matter (SOM) content, soil moisture, and CO2 flux from the plots. Additionally, we leached soils and measured dissolved organic carbon (DOC), total dissolved nitrogen (TDN), NH4, NO3, soluble reactive phosphorus (SRP), and chromophoric dissolved organic matter (CDOM). Furthermore, we measured extracellular activity of four enzymes involved in soil C and nutrient cycling (leucine aminopeptidase (LAP), β-glucosidase, phosphatase, and phenol oxidase). One day post-fire, LAP activity was similarly low in all treatments, but by 8 d post-fire, LAP activity was lower in burned plots compared to control plots, likely due to increased nitrogen content with increasing burn severity. Phosphatase activity decreased with burn severity 1 d post-fire, but after 8 d, moderate and severe burn plots exhibited increased phosphatase activity. Coupled with trends in LAP activity, this suggests a switch in nutrient limitation from N to phosphorus that is more pronounced with burn severity. β-glucosidase activity similarly decreased with burn

  15. Using speleothem growth periods to constrain Quaternary evolution of Siberian permafrost

    Science.gov (United States)

    Vaks, A.; Gutareva, O.; Breitenbach, S.; Osinzev, A.; Henderson, G. M.

    2010-12-01

    We have used speleothems from three caves along a north-south transect in Eastern Siberia to track the evolution of permafrost during the last ~650 ky. Speleothems form in caves only when the cave temperature (which approximates the mean annual surface air temperature) is above 0°C and meteoric waters can penetrate into the cave. Periods of speleothem deposition therefore provide a tracer for presence or absence of the permafrost. The northernmost cave used in this study, the Lenskaya Ledyanaya Cave (Icy Cave of Lena), is located at 60°22’N - 116°56’E, on the southern boundary of the continuous permafrost zone, with no present-day water seepage in the cave and large amounts of ice partially filling its inner chambers. Botovskaya Cave system (55°18'N; 105°21'E) is located in the discontinuous permafrost zone with water seepage and speleothem growth occurring only in a limited area of the cave. Okhotnichya Cave (52°07’N; 105°27’E), near southern Lake Baikal, is located in the zone of island permafrost, with water seepage and speleothem growth occurring in all parts of the cave. The mean annual temperatures vary from -7°C in the area of Lenskaya Ledyanaya Cave, to ~0°C in the Okhotnichya cave region, and the present-day vegetation in the area is sub-arctic taiga forest. More than 60 horizons from 15 speleothems from these three caves were dated by U-Th method. The high initial 234U/238U activity ratios in Siberian speleothems (3-6) extend the dateable range of the U-Th method to more than 650 ky. The youngest speleothem age in the Lenskaya Ledyanaya Cave was 626 ± 46 ky, probably corresponding to interglacial Marine Isotopic Stage (MIS) 15, whereas the other 11 other horizons in 6 additional speleothems from this cave were older than the dating limit. In Botovskaya and Okhotnichya caves speleothem ages clustered into warmest intervals of the interglacial periods at ~500 ky (MIS-13), 420-370 ky (MIS-11), 207-199 ky (MIS-7.2), 131-120 ky (MIS-5.5) and

  16. Use Of Amino Acid Racemization To Investigate The Metabolic Activity Of ?Dormant? Microorganisms In Siberian Permafrost

    Science.gov (United States)

    Tsapin, A.; McDonald, G.

    2002-12-01

    search for extraterrestrial life or its remnants is based on studying the most probable environments in which life (extant or extinct) may be found, and determining the maximum period of time over which such life could be preserved. The terrestrial permafrost, inhabited by cold adapted microbes, can be considered as an extraterrestrial analog environment. The cells and their metabolic end-products in Earth's permafrost can be used in the search for possible ecosystems and potential inhabitants on extraterrestrial cryogenic bodies. The study of microorganisms (or their remnants) that were buried for a few million years in permafrost provides us with a unique opportunity to determine the long-term viability of (micro)organisms. We have analyzed the degree of racemization of aspartic acid in permafrost samples from Northern Siberia (Brinton et al. 2002, Astrobiology 2, 77), an area from which microorganisms of apparent ages up to a few million years have previously been isolated and cultured. We find that the extent of aspartic acid racemization in permafrost cores increases very slowly up to an age of approximately 25,000 years (around 5 m depth). The apparent temperature of racemization over the age range 0-25,000 years, determined using measured aspartic acid racemization rate constants, is ?19 C. This apparent racemization temperature is significantly lower than the measured environmental temperature (?11 to ?13 C), and suggests active recycling of D-aspartic acid in Siberian permafrost up to an age of around 25,000 years. This indicates that permafrost organisms are capable of repairing some molecular damage incurred while they are in a ?dormant? state over geologic time.

  17. Storage and transformation of organic matter fractions in cryoturbated permafrost soils across the Siberian Arctic

    Directory of Open Access Journals (Sweden)

    N. Gentsch

    2015-02-01

    Full Text Available In permafrost soils, the temperature regime and the resulting cryogenic processes are decisive for the storage of organic carbon (OC and its small-scale spatial variability. For cryoturbated soils there is a lack in the assessment of pedon-scale heterogeneity in OC stocks and the transformation of functionally different organic matter (OM fractions such as particulate and mineral-associated OM. Therefore, pedons of 28 Turbels across the Siberian Arctic were sampled in five meter wide soil trenches in order to calculate OC and total nitrogen (TN stocks within the active layer and the upper permafrost based on digital profile mapping. Density fractionation of soil samples was performed to distinguish particulate OM (light fraction, LF, −3, mineral associated OM (heavy fraction, HF, >1.6 g cm−3, and a mobilizable dissolved pool (mobilizable fraction, MoF. Mineral-organic associations were characterized by selective extraction of pedogenic Fe and Al oxides and the clay composition was analyzed by X-ray diffraction. Organic matter transformation in bulk soil and density fractions was assessed by the stable carbon isotope ratio (δ13C and element contents (C and N. Across all investigated soil profiles, total OC stocks were calculated to 20.2 ± 8.0 kg m−2 (mean ± SD to 100 cm soil depth. Of this average, 54% of the OC was located in active layer horizons (annual summer thawing layer showing evidence of cryoturbation, and another 35% was present in the permafrost. The HF-OC dominated the overall OC stocks (55% followed by LF-OC (19% in mineral and 13% in organic horizons. During fractionation about 13% of the OC was released as MoF, which likely represents the most bioavailable OM pool. Cryogenic activity combined with an impaired biodegradation in topsoil horizons (O and A horizons were the principle mechanisms to sequester large OC stocks in the subsoil (16.4 ± 8.1 kg m−2; all mineral B, C, and permafrost horizons. About 22% of the subsoil

  18. Metal ion complex formation in small lakes of the Western Siberian Arctic zone

    Science.gov (United States)

    Kremleva, Tatiana; Dinu, Marina

    2017-04-01

    be predominantly in free, ionic or bound form with inorganic ligands. This state means paradox consequence that the increase of dissolved Fe content will lead to toxicity rise of other elements having less affinity to organic material. For surface waters of Western Siberian Arctic zone this situation is quite common. The total concentration of iron and aluminum ions in most lakes of tundra and northern taiga zones is approximately equal to water complexing ability. From the other side humic substances participation in inactivation of other more toxic metals (Cu, Pb, Cd, Cr, Ni et al.) will be poor. Arctic part of Western Siberia undergoes significant anthropogenic load due to extensive oil and gas recovery in this zone. Surface waters of Western Siberia are characterized by high natural content of iron, aluminum and copper ions and anthropogenic load of heavy metals makes the situation more serious.

  19. A model of the methane cycle, permafrost, and hydrology of the Siberian continental margin

    Science.gov (United States)

    Archer, D.

    2015-05-01

    -freezing) part of the cycle rather than during deglacial transgression (warming and thawing). The atmospheric flux response to a warming climate is small, relative to the rest of the methane sources to the atmosphere in the global budget, because of the ongoing flooding of the continental shelf. The increased methane flux due to ocean warming could be completely counteracted by a sea level rise of tens of meters on millennial timescales due to the loss of ice sheets, decreasing the efficiency of bubble transit through the water column. The model results give no indication of a mechanism by which methane emissions from the Siberian continental shelf could have a significant impact on the near-term evolution of Earth's climate, but on millennial timescales the release of carbon from hydrate and permafrost could contribute significantly to the fossil fuel carbon burden in the atmosphere-ocean-terrestrial carbon cycle.

  20. Regions. [Africa, Middle East].

    Science.gov (United States)

    1985-03-01

    This discussion of population focuses on the regions of Africa and the Middle East. In South Africa more white women are working but fewer black women work. The overall result is that the percentage of women who work is declining. Marita de Beer, research liaison executive at the South African Advertising Research Foundation, reports that the female population grew by 31% in the past 10 years while the number of working women has grown by only 11%. Among blacks the female population rose by 36%, but the number of workers among them declined by about 1%. Married women are among the fastest growing groups of working women in South Africa. The most recent estimate of the population of Nigeria is 92 million. According to Professor Vremudia Diejomaoh, Nigeria's population will probably reach 155 million by 2000 with 33% living in urban areas. In Saudi Arabia the Pan Arab Research Center recently completed a census of retail outlets in 3 metropolitan areas: Jeddah, Riyadh, and Dammam. The types of outlets surveyed include large supermarkets, small supermarkets, groceries with and without deep freeze, tobacco shops, meat shop/delis, small cafeterias, large restaurants/hotels, cosmetics shops or perfumeries, camera stores, toy shops, pharmacies, watch and gift shop, newsstands, department store, and appliance outlets. Using the Census of Retail Outlets as a base, Pan Arab Research Center also has a new distribution audit system that will cover 500 outlets. By plotting Arab countries according to their population policies and their current growth rates, it is possible to project where the middle class will grow fastest in the Arab world. The countries that have declining growth rates and strong population programs designed to encourage lower fertility rates among women are Egypt, Tunisia, Morocco, Algeria, and Lebanon. The countries most likely to have a better per capita distribution of resources within this decade are those where governments encourage reductions in

  1. Remote sensing observations for monitoring and mathematical simulations of transboundary air pollutants migration from Siberian mass wildfires to Kazakhstan

    Science.gov (United States)

    Kaipov, I. V.

    2017-03-01

    Anthropogenic and natural factors have increased the power of wildfires in massive Siberian woodlands. As a consequence, the expansion of burned areas and increase in the duration of the forest fire season have led to the release of significant amounts of gases and aerosols. Therefore, it is important to understand the impact of wildland fires on air quality, atmospheric composition, climate and accurately describe the distribution of combustion products in time and space. The most effective research tool is the regional hydrodynamic model of the atmosphere, coupled with the model of pollutants transport and chemical interaction. Taking into account the meteorological parameters and processes of chemical interaction of impurities, complex use of remote sensing techniques for monitoring massive forest fires and mathematical modeling of long-range transport of pollutants in the atmosphere, allow to evaluate spatial and temporal scale of the phenomenon and calculate the quantitative characteristics of pollutants depending on the height and distance of migration.

  2. [Humanities as a means of survival: the testimony of a Siberian prisoner of war in the First World War].

    Science.gov (United States)

    Inić, Suzana; Fatović-Ferenčić, Stella; Kujundžić, Nikola

    2015-11-01

    This article looks into the autobiography of the Croatian chemist and pharmacognosist Antun Vrgoč (1881-1949) entitled My Memories of the World War 1914-1920 and published in Zagreb in 1937. The author was captured in October 1914 and deported to Siberia, where he remained prisoner of war until 1920. Since there are few memoirs describing the life of Siberian prisoners during the First World War, this work is a precious testimony about the attitude towards the prisoners of war, human relations, and the survival of an AustroHungarian army officer. The book shows a striking lack of civilian or military hostility towards the prisoners and the respect of the Geneva Convention. Antun Vrgoč adopted the culture, customs and language of his formal enemies, took part in their civilian life, and taught at their university. His cathartic experience of survival includes a clear message about the absurdity of war.

  3. Nanoscience and nanotechnology in the Siberian Branch of the Russian Academy of Sciences: bibliometric analysis and evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Lavrik, Olga L., E-mail: lisa@spsl.nsc.ru; Busygina, Tatyana V. [Russian Academy of Sciences, State Public Scientific and Technological Library, Siberian Branch (Russian Federation); Shaburova, Natalya N. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation); Zibareva, Inna V., E-mail: zibareva@catalysis.ru [Russian Academy of Sciences, Boreskov Institute of Catalysis, Siberian Branch (Russian Federation)

    2015-02-15

    The multidimensional bibliometric analysis of publications on nanoscience and nanotechnology (NS&NT) produced by the researchers of the Siberian Branch of the Russian Academy of Sciences (SB RAS) in 2007–2012 has shown their growing publication activity and international visibility in the field and the main objects of research such as nanoparticles, nanostructures (nanostructured materials), nanotubes (especially carbon ones), nanocomposites, nanocrystals, nanotechnology, and nanoelectronics and identified the most productive authors and institutes, as well as the most cited publications. It was made using the data from multidisciplinary (Web of Science, Scopus, and Russian Index of Scientific Citation) and specialized (Chemical Abstracts Plus and Inspec) information resources, that is from international (WoS, Scopus, CAPlus, and Inspec) and national (RISC) data bases. The analysis has shown that most of the SB RAS research works on NS&NT are concentrated in Novosibirsk Scientific Centre.

  4. Rf Depolarizing Resonances In The Presence Of A Full Siberian Snake And Full Snake Spin-flipping

    CERN Document Server

    Blinov, B B

    2000-01-01

    Frequent polarization reversals, or spin-flips, of a stored polarized beam in high energy scattering asymmetry experiments may greatly reduce systematic errors of spin asymmetry measurements. A spin-flipping technique is being developed by using rf magnets running at a frequency close to the spin precession frequency, thereby creating spin-depolarizing resonances; the spin can then be flipped by ramping the rf magnet's frequency through the resonance. We studied, at the Indiana University Cyclotron Facility Cooler Ring, properties of such rf depolarizing resonances in the presence of a nearly-full Siberian snake and their possible application for spin- flipping. By using an rf-solenoid magnet, we reached a 98.7 ± 1% efficiency of spin-flipping. However, an rf-dipole magnet is more practical at high energies; hence, studies of spin-flipping by an rf-dipole are underway at IUCF.

  5. Comparison of mantle lithosphere beneath early Triassic kimberlite fields in Siberian craton reconstructed from deep-seated xenocrysts

    Directory of Open Access Journals (Sweden)

    I.V. Ashchepkov

    2016-07-01

    Kharamai mantle clinopyroxenes represent three geochemical types: (1 harzburgitic with inclined linear REE, HFSE troughs and elevated Th, U; (2 lherzolitic or pyroxenitic with round TRE patterns and decreasing incompatible elements; (3 eclogitic with Eu troughs, Pb peak and high LILE content. Calculated parental melts for garnets with humped REE patterns suggest dissolution of former Cpx and depression means Cpx and garnets extraction. Clinopyroxenes from Ary-Mastakh fields show less inclined REE patterns with HMREE troughs and an increase of incompatible elements. Clinopyroxenes from Kuranakh field show flatter spoon-like REE patterns and peaks in Ba, U, Pb and Sr, similar to those in ophiolitic harzburgites. The PT diagrams for the mantle sections show high temperature gradients in the uppermost SCLM accompanied by an increase of P-Fe#Ol upward and slightly reduced thickness of the mantle keel of the Siberian craton, resulting from the influence of the Permian–Triassic superplume, but with no signs of delamination.

  6. Nanoscience and nanotechnology in the Siberian Branch of the Russian Academy of Sciences: bibliometric analysis and evaluation

    Science.gov (United States)

    Lavrik, Olga L.; Busygina, Tatyana V.; Shaburova, Natalya N.; Zibareva, Inna V.

    2015-02-01

    The multidimensional bibliometric analysis of publications on nanoscience and nanotechnology (NS&NT) produced by the researchers of the Siberian Branch of the Russian Academy of Sciences (SB RAS) in 2007-2012 has shown their growing publication activity and international visibility in the field and the main objects of research such as nanoparticles, nanostructures (nanostructured materials), nanotubes (especially carbon ones), nanocomposites, nanocrystals, nanotechnology, and nanoelectronics and identified the most productive authors and institutes, as well as the most cited publications. It was made using the data from multidisciplinary (Web of Science, Scopus, and Russian Index of Scientific Citation) and specialized (Chemical Abstracts Plus and Inspec) information resources, that is from international (WoS, Scopus, CAPlus, and Inspec) and national (RISC) data bases. The analysis has shown that most of the SB RAS research works on NS&NT are concentrated in Novosibirsk Scientific Centre.

  7. 4-Vinylcyclohexene diepoxide reduces fertility in female Siberian hamsters when treated during their reproductively active and quiescent states.

    Science.gov (United States)

    Roosa, Kristen A; Mukai, Motoko; Place, Ned J

    2015-01-01

    The industrial compound 4-vinylcyclohexene diepoxide (VCD) destroys ovarian follicles and reduces fertility in rodents, but to date VCD has not been tested in species that experience seasonal anestrus. To determine if VCD destroys follicles when administered during reproductive quiescence, Siberian hamsters were treated with VCD (240mg/kg i.p. daily for 10 days) during short days, and outcomes were compared with reproductively active females that were maintained and treated in long days. Primordial follicle numbers were significantly reduced by VCD under both day lengths, and reproductive quiescence in short days did not appear to render the ovaries less susceptible to VCD-induced follicle depletion. Independent of day length and reproductive state, VCD-treated hamsters weaned substantially fewer offspring than controls. These results suggest that time of year may not be an important consideration for optimizing use of VCD in the field when the target pest species is a seasonally breeding rodent.

  8. The contribution of Alaskan, Siberian, and Canadian coastal polynas to the cold halocline layer of the Arctic Ocean

    Science.gov (United States)

    Cavalieri, Donald J.; Martin, Seelye

    1994-01-01

    Numerous Arctic Ocean circulation and geochemical studies suggest that ice growth in polynyas over the Alaskan, Siberian, and Canadian continental shelves is a source of cold, saline water which contributes to the maintenance of the Arctic Ocean halocline. The purpose of this study is to estimate for the 1978-1987 winters the contributions of Arctic coastal polynyas to the cold halocline layer of the Arctic Ocean. The study uses a combination of satellite, oceanographic, and weather data to calculate the brine fluxes from the polynyas; then an oceanic box model is used to calculate their contributions to the cold halocline layer of the Arctic Ocean. This study complements and corrects a previous study of dense water production by coastal polynyas in the Barents, Kara, and Laptev Seas.

  9. A varved lake sediment record from Finland: between the North Atlantic Oscillation and Siberian High Pressure Cell

    Science.gov (United States)

    Saarni, Saija; Saarinen, Timo

    2015-04-01

    Varved lake sediments are widely used for paleoclimatological and paleoenvironmental studies. The advantages of such records are precise time control, which enables high resolution studies of even seasonal scale, and the length of the records extending potentially beyond thousands of years. The clastic organic varved sediments from a small boreal Lake Kalliojärvi (area 0.15 km2, maximum depth 12 m) in Central Finland, record environmental change and snow accumulation history for more than two thousand years. The high quality sediments of the Lake Kalliojärvi are laminated until the present day and reflect the annual circulation of boreal zone. A single varve year consists of two laminae that are composed of i) minerogenic clasts and ii) amorphous organic matter and microfossils. Total varve thickness was measured, and the accumulation of minerogenic and organic matter were analyzed using digital image analysis. The major element composition of the lake sediments was also determined using micro X-ray fluorescence (µ-XRF). The clastic laminae are interpreted as a proxy for catchment erosion, reflecting spring floods triggered by snow melt. Qualitative comparison of minerogenic matter accumulation and reconstructed North Atlantic Oscillation (NAO) phases reveal correspondence between the two records. Positive NAO conditions occur simultaneously with increased minerogenic lamina thicknesses which suggest that the changes in snow accumulation are induced by NAO. However, there are indications that the strong Siberian High Pressure Cell (SHPC) prevailing on eastern Scandinavia may be important for Scandinavian climate via blocking the westerly winds. Strong SHCP potentially leads to colder winter temperatures in Finland and increased ice formation. Stronger and prolonged ice cover in lake environments cause prolonged water column stratification and increased oxygen deficiency which is related to an increased Fe/Mn ratio. This study discusses the importance of NAO and

  10. Short-day aggression is independent of changes in cortisol or glucocorticoid receptors in male Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    Scotti, Melissa-Ann L; Rendon, Nikki M; Greives, Timothy J; Romeo, Russell D; Demas, Gregory E

    2015-06-01

    Testosterone mediates aggression in many vertebrates. In some species, aggression remains high during the non-breeding season (e.g., winter), when testosterone levels are low. In Siberian hamsters (Phodopus sungorus), we have demonstrated photoperiodic changes in aggression with hamsters housed in short, "winter-like" days displaying significantly more territorial aggression than long-day animals, despite low levels of testosterone. The mechanisms by which photoperiod regulates aggression, however, remain largely unknown. Adrenocortical hormones (e.g., glucocorticoids) have been implicated in mediating seasonal aggression; circulating concentrations of these hormones have been correlated with aggression in some species. The goal of this study was to examine the role of cortisol and glucocorticoid receptors in mediating photoperiodic changes in aggression in male Siberian hamsters. Males were housed in long or short days and treated with either exogenous cortisol or vehicle. Circulating levels of cortisol, adrenal cortisol content, and aggression were quantified. Lastly, photoperiodic effects on glucocorticoid receptor (GR) protein levels were quantified in limbic brain regions associated with aggression, including medial prefrontal cortex, amygdala, and hippocampus. Short-day hamsters were more aggressive than long-day hamsters, however cortisol treatment did not affect aggression. Photoperiod had no effect on serum or adrenal cortisol or GR levels in the brain regions examined. Taken together, these data suggest that increases in cortisol levels do not cause increases associated with short-day aggression, and further that GR protein levels are not associated with photoperiodic changes in aggression. The results of this study contribute to our understanding of the role of adrenocortical steroids in mediating seasonal aggression.

  11. Photoperiodic changes in endocannabinoid levels and energetic responses to altered signalling at CB1 receptors in Siberian hamsters.

    Science.gov (United States)

    Ho, J M; Smith, N S; Adams, S A; Bradshaw, H B; Demas, G E

    2012-07-01

    Siberian hamsters (Phodopus sungorus) adapt to seasonal environmental conditions with marked changes in body mass, primarily in the form of adiposity. Winter-like conditions (e.g. short days) are sufficient to decrease body mass by approximately 30% in part via reductions in food intake. The neuroendocrine mechanisms responsible for these changes are not well understood, and homeostatic orexigenic/anorexigenic systems of the hypothalamus provide little explanation. We investigated the potential role of endocannabinoids, which are known modulators of appetite and metabolism, in mediating seasonal changes in energy balance. Specifically, we housed hamsters in long or short days for 0, 3, or 9 weeks and measured endocannabinoid levels in the hypothalamus, brainstem, liver and retroperitoneal white adipose tissue (RWAT). An additional group of males housed in short days for 25 weeks were also compared with long-day controls. Following 9 weeks in short days, levels of the endocannabinoid 2-arachidonoylglycerol (2-AG) were significantly elevated in RWAT and reduced in brainstem, although they returned to long-day levels by week 25 in short-day males that had cycled back to summer-like energy balance. Endocannabinoid levels in these tissues correlated significantly with adiposity and change in body mass. No photoperiodic changes were observed in the hypothalamus or liver; however, sex differences in 2-AG levels were found in the liver (males > females). We further tested the effects of CB(1) receptor signalling on ingestive behaviour. Five daily injections of CB(1) antagonist SR141716 significantly reduced food intake and body mass but not food hoarding. Although the CB(1) agonist arachidonyl-2-chloroethylamide did not appreciably affect either ingestive behaviour, body mass was significantly elevated following 2 days of injections. Taken altogether, these findings demonstrate that endocannabinoid levels vary with sex and photoperiod in a site-specific manner, and that

  12. Photoperiod regulates genes encoding melanocortin 3 and serotonin receptors and secretogranins in the dorsomedial posterior arcuate of the Siberian hamster.

    Science.gov (United States)

    Nilaweera, K N; Archer, Z A; Campbell, G; Mayer, C-D; Balik, A; Ross, A W; Mercer, J G; Ebling, F J P; Morgan, P J; Barrett, P

    2009-02-01

    The mechanism(s) involved in the regulation of the seasonal-appropriate body weight of the Siberian hamster are currently unknown. We have identified photoperiodically regulated genes including VGF in a sub-region of the arcuate nucleus termed the dorsomedial posterior arcuate (dmpARC). Gene expression changes in this nucleus so far account for a significant number of those reported as photoperiodically regulated and are therefore likely to contribute to seasonal physiological responses of the hamsters. The present study aimed to identify additional genes expressed in the dmpARC regulated by photoperiod that could be involved in regulating the activity of this nucleus with respect to seasonal physiology of the Siberian hamster. Using laser capture microdissection coupled with a microarray analysis and a candidate gene approach, we have identified several photoperiodically regulated genes in the dmpARC that are known to have roles in secretory and intracellular signalling pathways. These include secretogranin (sg) III and SgVI (secretory pathway), melanocortin 3 receptor (MC3-R) and serotonin (5-HT) receptors 2A and 7 (signalling pathway), all of which increase in expression under a short photoperiod. The spatial relationship between receptor signalling and potential secretory pathways was investigated by dual in situ hybridisation, which revealed that 5-HT2A and 5-HT7 receptors are expressed in neurones expressing VGF mRNA and that a sub-population (approximately 40%) of these neurones express MC3-R. These gene expression changes in dmpARC neurones may reflect the functional requirement of these neurones for seasonal physiological responses of the hamster.

  13. Photoperiod-dependent regulation of carboxypeptidase E affects the selective processing of neuropeptides in the seasonal Siberian hamster (Phodopus sungorus).

    Science.gov (United States)

    Helwig, M; Herwig, A; Heldmaier, G; Barrett, P; Mercer, J G; Klingenspor, M

    2013-02-01

    The production of bioactive peptides from biologically inactive precursors involves extensive post-translational processing, including enzymatic cleavage by proteolytic peptidases. Endoproteolytic prohormone-convertases initially cleave the precursors of many neuropeptides at specific amino acid sequences to generate intermediates with basic amino acid extensions on their C-termini. Subsequently, the related exopeptidases, carboxypeptidases D and E (CPD and CPE), are responsible for removing these amino acids before the peptides achieve biological activity. We investigated the effect of photoperiod on the processing of the neuropeptide precursor pro-opiomelanocortin (POMC) and its derived neuropeptides, α-melanocyte-stimulating hormone (MSH) and β-endorphin (END), within the hypothalamus of the seasonal Siberian hamster (Phodopus sungorus). We thus compared hypothalamic distribution of CPD, CPE, α-MSH and β-END using immunohistochemistry and measured the enzyme activity of CPE and concentrations of C-terminally cleaved α-MSH in short-day (SD; 8 : 16 h light/dark) and long-day (LD; 16 : 8 h light/dark) acclimatised hamsters. Increased immunoreactivity (-IR) of CPE, as well as higher CPE activity, was observed in SD. This increase was accompanied by more β-END-IR cells and substantially higher levels of C- terminally cleaved α-MSH, as determined by radioimmunoassay. Our results suggest that exoproteolytic cleavage of POMC-derived neuropeptides is tightly regulated by photoperiod in the Siberian hamster. Higher levels of biological active α-MSH- and β-END in SD are consistent with the hypothesis that post-translational processing is a key event in the regulation of seasonal energy balance.

  14. Acute downregulation of Type II and Type III iodothyronine deiodinases by photoperiod in peripubertal male and female Siberian hamsters.

    Science.gov (United States)

    Kampf-Lassin, August; Prendergast, Brian J

    2013-11-01

    Availability of the thyroid hormone triiodothyronine (T3) in the mediobasal hypothalamus plays a central role in seasonal reproductive responses to photoperiod. Across many vertebrates, Type 2 iodothyronine deiodinase (DIO2) is elevated under reproductively stimulatory long days (LD) and synthesizes the conversion of thyroxine to T3; Type 3 iodothyronine deiodinase (DIO3) reduces T3 production and signaling, and is upregulated under reproductively-inhibitory short days (SD). In Siberian hamsters, regulation of hypothalamic T3 is dominated by dio3 expression, whereas dio2 expression is less-consistently affected by photoperiod. In adult hamsters, changes in deiodinase mRNA expression typically require several weeks to manifest, but it is not known whether or how quickly these mechanisms are engaged during the rapid responses to photoperiod observed in young, peri-pubertal hamsters. This experiment tested the hypotheses that (1) deiodinase responses to photoperiod are accelerated in juvenile hamsters and (2) photoperiodic downregulation of deiodinase expression occurs more rapidly than upregulation. Hypothalamic dio2 and dio3 mRNA expression was quantified in male and female Siberian hamsters that were weaned on postnatal day 18 (PND 18) into SD or remained in their natal LD, and on PND 31 were exposed to a single long or short day. In SD males and females, a single long day inhibited dio3 mRNA expression, but did not increase dio2 mRNA. In LD males, a single short day rapidly inhibited dio2 mRNA expression, but did not stimulate expression of dio3 mRNA. Downregulation of dio2 and dio3 mRNAs precedes gonadotrophin responses to day length. Rapid photoperiodic inhibition of deiodinase mRNAs may initiate changes in thyroid hormone signaling in advance of longer-term, melatonin-dependent, responses.

  15. Photoperiod and acute energy deficits interact on components of the thyroid hormone system in hypothalamic tanycytes of the Siberian hamster.

    Science.gov (United States)

    Herwig, Annika; Wilson, Dana; Logie, Tracy J; Boelen, Anita; Morgan, Peter J; Mercer, Julian G; Barrett, Perry

    2009-05-01

    In the Siberian hamster, seasonal weight loss occurs gradually over many weeks during autumn and winter. This is driven by a regulatory mechanism that is able to integrate duration of exposure to short days (SDs) with the size of body energy reserves. After food restriction in SDs, followed by ad libitum refeeding, body weight of the hamster does not return to its former level; rather, it increases to a level defined by the length of time spent in SDs. In this report, we show that components of the thyroid hormone system that are involved in seasonal weight loss change expression in response to 48 h of starvation. Eight weeks in an SD photoperiod induced weight loss in the Siberian hamster. In the hypothalamus of these hamsters, type II deiodinase expression was decreased and type III deiodinase expression was induced, but there was no change in hypothalamic neuropeptide Y or thyrotropin-releasing hormone gene expression. For the first time, we show that the thyroid hormone transporter monocarboxylate transporter 8 is expressed in tanycytes and is increased in response to an SD photoperiod. Food restriction (48 h of starvation) reversed the direction of gene expression change for type II and III deiodinase and monocarboxylate transporter 8 induced by SD photoperiods. Furthermore, fasting increased neuropeptide Y expression and decreased thyrotropin-releasing hormone expression. VGF, a gene upregulated in SDs in the dorsal region of the medial posterior area of the arcuate nucleus, was not changed by starvation. These data point to a mechanism whereby energy deprivation can interact with an SD photoperiod on hypothalamic tanycytes to regulate components of the thyroid hormone system involved in photoperiodic regulation of seasonal physiology.

  16. Somatostatin Agonist Pasireotide Promotes a Physiological State Resembling Short-Day Acclimation in the Photoperiodic Male Siberian Hamster (Phodopus sungorus).

    Science.gov (United States)

    Dumbell, R A; Scherbarth, F; Diedrich, V; Schmid, H A; Steinlechner, S; Barrett, P

    2015-07-01

    The timing of growth in seasonal mammals is inextricably linked to food availability. This is exemplified in the Siberian hamster (Phodopus sungorus), which uses the annual cycle of photoperiod to optimally programme energy expenditure in anticipation of seasonal fluctuations in food resources. During the autumn, energy expenditure is progressively minimised by physiological adaptations, including a 30% reduction in body mass, comprising a reduction in both fat and lean tissues. However, the mechanistic basis of this adaptation is still unexplained. We hypothesised that growth hormone (GH) was a likely candidate to underpin these reversible changes in body mass. Administration of pasireotide, a long-acting somatostatin receptor agonist developed for the treatment of acromegaly, to male hamsters under a long-day (LD) photoperiod produced a body weight loss. This comprised a reduction in lean and fat mass, including kidneys, testes and brown adipose tissue, typically found in short-day (SD) housed hamsters. Furthermore, when administered to hamsters switched from SD to LD, pasireotide retarded the body weight increase compared to vehicle-treated hamsters. Pasireotide did not alter photoperiod-mediated changes in hypothalamic energy balance gene expression but altered the expression of Srif mRNA expression in the periventricular nucleus and Ghrh mRNA expression in the arcuate nucleus consistent with a reduction in GH feedback and concurrent with reduced serum insulin-like growth factor-1. Conversely, GH treatment of SD hamsters increased body mass, which included increased mass of liver and kidneys. Together, these data indicate a role for the GH axis in the determination of seasonal body mass of the Siberian hamster.

  17. Enhanced enzymatic activity of glycerol-3-phosphate dehydrogenase from the cryophilic Saccharomyces kudriavzevii.

    Science.gov (United States)

    Oliveira, Bruno M; Barrio, Eladio; Querol, Amparo; Pérez-Torrado, Roberto

    2014-01-01

    During the evolution of the different species classified within the Saccharomyces genus, each one has adapted to live in different environments. One of the most important parameters that have influenced the evolution of Saccharomyces species is the temperature. Here we have focused on the study of the ability of certain species as Saccharomyces kudriavzevii to grow at low temperatures, in contrast to Saccharomyces cerevisiae. We observed that S. kudriavzevii strains isolated from several regions are able to synthesize higher amounts of glycerol, a molecule that has been shown to accumulate in response to freeze and cold stress. To explain this observation at the molecular level we studied the expression of glycerol biosynthetic pathway genes and we observed a higher expression of GPD1 gene in S. kudriavzevii compared to S. cerevisiae in micro-vinification conditions. We observed higher enzymatic activity of Gpd1p in S. kudriavzevii in response to osmotic and cold stress. Also, we determined that S. kudriavzevii Gpd1p enzyme presents increased catalytic properties that will contribute to increase glycerol production. Finally, we evaluated the glycerol production with S. cerevisiae, S. kudriavzevii or a recombinant Gpd1p variant in the same background and observed that the S. kudriavzevii enzyme produced increased glycerol levels at 12 or 28°C. This suggests that glycerol is increased in S. kudriavzevii mainly due to increased V max of the Gpd1p enzyme. All these differences indicate that S. kudriavzevii has changed the metabolism to promote the branch of the glycolytic pathway involved in glycerol production to adapt to low temperature environments and maintain the NAD(+)/NADH ratio in alcoholic fermentations. This knowledge is industrially relevant due to the potential use, for example, of S. cerevisiae-S. kudriavzevii hybrids in the wine industry where glycerol content is an important quality parameter.

  18. Tug of war for the Eastern Siberian oil pipeline; Touwtrekken om de Oost-Siberische oliepijpleiding

    Energy Technology Data Exchange (ETDEWEB)

    Chrisstoffels, J.H.; Handke, S.

    2007-10-15

    The authors discuss the history and importance of the East-Siberia-Pacific Oil Pipeline (ESPO). This new pipeline is a crucial element of Russia's energy strategy, which calls for the diversification of Russian energy exports by developing East Siberia's oil and gas resources. The authors recall how the Russian state lost its grip on the economy in the 1990s when oligarchs, such as Michail Khodorkovsky, were able to take control over the oil sector, in particular East Siberia's resources. Khodorkovsky bypassed the Moscow government and proposed building a pipeline to China. His plans were only focused on his company's interests, while the Russian state would only get a small share of the revenues. The re-emerging Russian state under president Putin brought a halt to this project and opted for a route that would give Russia the opportunity to export oil to Japan. The struggle for this pipeline and its final route provides an interesting case study of recent political changes in Russia. Furthermore, it illustrates how the Russian state has re-asserted control over the energy industry and which role energy plays in the country's foreign economic policy. Siberia's energy resources can help Russia to participate in the economic rise of the Asia-Pacific region. ESPO is a first step to realize Siberia's potential and to boost Russia's political and economic position in East Asia and beyond. Hence the pipeline is a clear signal of Russia's re-emergence as a powerful player on the Eurasian continent. [Dutch] De auteurs bespreken de geschiedenis en het belang van de Oost-Siberie - Pacific Oil Pipeline (ESPO). Deze nieuwe pijpleiding is een cruciaal onderdeel in de Russische energie-strategie, waarin wordt opgeroepen tot de diversificatie van de Russische energie-export door het ontwikkelen van Oost-Siberische olie- en gasbronnen. De auteurs herinneren eraan hoe de Russische staat zijn greep verloor op de economie in de jaren 1990

  19. Politeness: West and East

    Directory of Open Access Journals (Sweden)

    - Джеффри Лич

    2014-12-01

    Full Text Available The present paper was planned for this issue of our journal, which Geoffrey Leech and I intended to devote to Politeness phenomena across cultures. It is based on his article titled “Politeness: Is there an East-West Divide?” (2005 which he suggested as a theoretical framework and includes results of our discussions held during our personal meetings and our epistolary exchange. Unfortunately the final version of the paper was never read by Geoffrey Leech for the reasons we all sadly know. Nevertheless I decided to publish it as a tribute to him in the knowledge that the result was not going to have the degree of excellence it would have had if he were still with us today. I therefore apologise for any mistakes or misinterpretations of his thoughts that might be found in the paper. The aim of this article is to sum up the main ideas of Politeness Theory presented earlier in Leech 1983, 2003, 2005, and other publications and discuss how that theory applies (or fails to apply to other languages, with the main emphasis on the Russian language and culture. The term ‘maxim’ used in Principles of Pragmatics (Leech 1983 is avoided here as much as possible, as it implies some kind of moral imperative, rather than a pragmatic constraint. Instead, a single constraint, which comprehends all the maxims (the Maxims of Tact, Generosity, Approbation, Modesty, Agreement, Sympathy, and is called the Grand Strategy of Politeness (GSP, is used. The GSP says: In order to be polite, S expresses or implies meanings which place a high value on what pertains to O- his/her wants, qualities, obligation, opinion, feelings (O = other person[s], [mainly the addressee, i.e. H = hearer] or place a low value on what pertains to S (S = self, speaker. The essential point is that these are not separate, independent constraints or maxims: they are instances of the operation of the GSP as ‘super-maxim’ which is an overarching framework for studying linguistic politeness

  20. Simulation Study of the Vegetation Structure and Function in Eastern Siberian Larch Forests Using the Individual-Based Dynamic Vegetation Model SEIB-DGVM

    Science.gov (United States)

    Sato, H.; Kobayashi, H.; Delbart, N.

    2008-12-01

    The global ecosystem model SEIB-DGVM was adapted for an eastern Siberian larch forest through incorporation of empirical rules of allometry, allocation, and phenology developed for a larch stand at the Spasskaya-pad tower site. After calibration, the model reconstructed post-fire successional patterns of forest structure and carbon cycling. It also reconstructed seasonal changes in carbon, water, and energy cycling in a mature larch forest. When the model was applied to the entire larch-dominated region of eastern Siberia, the simulation was comparable to the latitudinal gradient of aboveground biomass. Sensitivity analysis showed that plant productivity and biomass were mainly limited by available water at Spasskaya-pad, where mean annual precipitation is only 257 mm. However, on a geographical scale encompassing all of eastern Siberia, productivity and biomass were limited mainly by temperature. These results suggest that the effects of global warming on Siberian larch forests depend on the adequacy of the water supply.

  1. RANGING RESULTS FOR TERRITORIES OF SIBERIAN AND FAR EASTERN FEDERAL DISTRICTS AIMED AT THE EVALUATION OF THE IMPACT OF TUBERCULOSIS CONTROL MEASURES ON THE EPIDEMIC SITUATION

    Directory of Open Access Journals (Sweden)

    T. V. Аlekseeva

    2016-01-01

    Full Text Available Efficiency of tuberculosis control measures was comprehensively evaluated in the Russian regions (totally 21 regions within Siberian and Far Eastern Federal Districts by means of ranging the sets of indicators. Three sets of indicators were used; these indicators reflected the epidemic situation and main rates of operation in the territories upon the outcomes of 2015. Totally 34 indicators were analyzed. The situation varies in different regions of Siberian and Far Eastern Federal Districts, the analyzed indicators significantly differ in the regions depending on the annual results, which first of all witnesses of differences in the quality and efficiency of tuberculosis control activities. Ranging as per indicators' set demonstrates the correlation between the epidemic situation and quality of tuberculosis control activities and stability of their level.

  2. Peculiarities of mantle lithosphere beneath the large kimberlite pipes in different regions for Siberian craton

    Science.gov (United States)

    Ashchepkov, Igor; Logvinova, Alla; Ntaflos, Theodoros; Vladykin, Nikolai; Spetsius, Zdislav; Kostrovitsky, Sergey; Stegnitsky, Yuri; Prokopyev, Sergey

    2016-04-01

    the walls. 6. Large productive pipes demonstrate abundance of the eclogites showing the signs of re-melting and formation of conduits for the rising melts 7. The temperature and pressure histograms for the xenocrysts and captured xenolith from the large diamondiferous pipes reveal the peaks in the High P -T conditions. Large pipes of low diamond grade demonstrate commonly complex magmatic history with the essential oxidation of melts in the latest stages. In different terranes the structure of the lithosphere have individual features, In Magan terrane Mir and closely located pipes demonstrate very depleted high- pressure SCLM part and developed pyroxenite layer in MSCLM with the metasomatic upper part. . In Daldyn terrane systematic differences in compositions of mantle pyropes and clinopyroxenes from large kimberlite pipes in the Alakit and Daldyn fields in Siberia suggest different geodynamic position. All pipes demonstrate good layering but the most productive pipes reveal more contrast SCLM structures. In the Alakit field, Cr-diopsides are much more alkaline and contain more sub-calcic pyropes and dunitic-type diamond inclusions like in Stykanskaya and some other pipes, while in the Daldyn field harzburgitic pyropes are frequent. The eclogitic diamond inclusions in the Alakit field are sharply divided in types and PT conditions, while in the Daldyn field they show varying compositions and often continuous PT ranges with increasing Fe# with decreasing pressures. In Markha terrane in Nakyn field the rhythmic layering beneath the Nyurbinskaya and Botuobinskaya pipes is accompanied by the abundance of the Al- rich eclogites with the domination of the Ca- rich types in the lower part of mantle section. In Upper Muna field the LSCLM part is abundant in the pyroxenite material in contrast to the other mantle segments of Siberian platform. The diamond grade in this part is lower but the quality of the diamonds is higher. Supported by the RFBR grants: 05-05-64718, 03

  3. U.S. and East Asian Integration

    Institute of Scientific and Technical Information of China (English)

    Lin Limin

    2008-01-01

    the U.S. is directly impacting on the future of the East Asian community. Therefore, finding ways to get along with the U.S. is crucial to the speed, direction, configuration and character of the East Asian community. In this paper, the author has analyzed the interests of the United States in East Asia and its stands towards the East Asian integration. The author concludes that it is to the interest of the United States to make more efforts to further join in the East Asian integration.And East Asia should accept and welcome the American participation.

  4. Big Prospects in East Asia

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    After bottoming out last year, the emerging economies of East Asia are recouping their losses and setting out onto the fast growth track.But short-term growth does not necessarily indicate a prosperous future-the region still needs to rebalance its economies and precipitate a massive shift to green technologies and energy efficiency. The World Bank discussed this issue in the latest EastAsia & Pacific Economic Update,a biannual assessment of economies in the region.Edited excerpts follow:

  5. Interannual variations of the dominant modes of East Asian winter monsoon and possible links to Arctic sea ice

    Science.gov (United States)

    Sun, Chenghu; Yang, Song; Li, Weijing; Zhang, Ruonan; Wu, Renguang

    2016-07-01

    Two dominant modes of the winter temperature over East Asia, a northern mode and a southern mode, and their links with Arctic climate conditions are analyzed. The relationships of the two modes with Arctic sea ice are different. The northern mode is closely linked to variations in sea ice of the Arctic Barents-Laptev Sea in previous autumn and most of the Arctic in concurrent winter. The southern mode seems independent from the Arctic sea ice variations, but is associated with sea surface temperature (SST) anomalies in the equatorial central-eastern Pacific. Results suggest an effect of Arctic sea ice variation on the northern mode and an influence of tropical SST anomalies on the southern mode. Reduced sea ice over the Arctic increases 1000-500-hPa thickness over the high-latitudes of Eurasian continent, which reduces the meridional thickness gradient between the middle and high latitudes and thus weakens the extratropical upper-level zonal wind. The weakened zonal wind provides a favorable dynamic condition for the development of a high-latitude ridge around the Ural Mountain. Reduced Arctic sea ice also tends to enhance the Siberian high through both thermodynamic and dynamic processes. The above atmospheric circulation patterns provide a favorable condition for the intrusion of cold air to northern East Asia.

  6. Characteristics of the Extreme Low Temperature Events in Winter Half Year in China and Its Relationship to East Asian Winter Monsoon

    Science.gov (United States)

    Han, Yongqiu; Zhou, Lian-Tong

    2017-04-01

    Based on daily minimum temperature dataset from 553 stations from 1961 to 2012 in China, extreme low temperature (ELT) thresholds are determined for different stations and occurrence frequency of ELT events in winter half year for each station is estimated and analyzed. And then several partitions in China are divided by empirical orthogonal function and it is verified to be credible by correlation analysis. Meanwhile, the spatial and temporal distribution of ELT events in each sub-region is diagnosed. Finally, the relationship between ELT events and East Asian winter monsoon (EAWM) circulation is studied by doing some correlation analysis. The results suggest that: the ELT events in winter half year in China are remarkably decreased in recent 51 years, but there are some differences between southern and northern areas. From 1964 to 1980, the ELT events in northeast, north and northwest of China are more than average and that are less than average in south, east and southwest of China, while it is just the reverse from 1981 to 1996. Moreover, the distribution of ELT events also shows a longitudinal oscillation. The correlation analysis between the frequency of ELT events in winter half year and EAWM index indicates that the two has good correlation with each other. And meanwhile, the correlation analysis between the frequency of ELT events in winter half year and sea level pressure shows that the former has a good positive correlation with Siberian High. Besides, the distribution of the difference between two period mean sea level pressure, from 1961 to 1979 and from 1980 to 2011, shows that Siberian High has an obviously southwardly movement and a trend of weakening after 1980, which go against the outbreak of the cold, that is why the ELT events in winter half year in most areas of China have an abrupt decrease.

  7. Active components from Siberian ginseng (Eleutherococcus senticosus) for protection of amyloid β(25-35)-induced neuritic atrophy in cultured rat cortical neurons.

    Science.gov (United States)

    Bai, Yanjing; Tohda, Chihiro; Zhu, Shu; Hattori, Masao; Komatsu, Katsuko

    2011-07-01

    Not only neuronal death but also neuritic atrophy and synaptic loss underlie the pathogenesis of Alzheimer's disease as direct causes of the memory deficit. Extracts of Siberian ginseng (the rhizome of Eleutherococcus senticosus) were shown to have protective effects on the regeneration of neurites and the reconstruction of synapses in rat cultured cortical neurons damaged by amyloid β (Aβ)(25-35), and eleutheroside B was one of the active constituents. In this study, a comprehensive evaluation of constituents was conducted to explore active components from Siberian ginseng which can protect against neuritic atrophy induced by Aβ(25-35) in cultured rat cortical neurons. The ethyl acetate, n-butanol and water fractions from the methanol extract of Siberian ginseng showed protective effects against Aβ-induced neuritic atrophy. Twelve compounds were isolated from the active fractions and identified. Among them, eleutheroside B, eleutheroside E and isofraxidin showed obvious protective effects against Aβ(25-35)-induced atrophies of axons and dendrites at 1 and 10 μM.

  8. Isolation and characterization of an atypical Siberian sturgeon herpesvirus strain in Russia: novel North American Acipenserid herpesvirus 2 strain in Europe?

    Science.gov (United States)

    Doszpoly, A; Kalabekov, I M; Breyta, R; Shchelkunov, I S

    2017-02-27

    Siberian sturgeon herpesvirus (SbSHV) was isolated in Russia for the first time in 2006. Nine SbSHV isolates were recovered from different fish hatcheries producing the same cytopathic effect in cell cultures, the same clinical signs and mortality kinetics in virus-infected fish and the same virus neutralization pattern and shared identical nucleotide sequences. In 2011, a new isolate was recovered from juvenile sturgeon, which caused completely different cytopathic effect. That isolate was not readily neutralized by Siberian sturgeon hyperimmune antisera, and its DNA was not recognized by the routine PCR developed for SbSHV detection. Molecular study of the novel isolate revealed that it was more closely related to North American Acipenserid herpesvirus 2 (AciHV-2) isolates from white sturgeon, while the genome sequences of the former SbSHV isolates showed high similarity to the AciHV-2 isolated from shortnose sturgeon. While clinical signs and mortality caused by the novel isolate in infected Siberian sturgeon were similar to those of the formerly described SbSHV isolates, the incubation period and mean time to death produced by the novel isolate were twice as long. The differences between the former isolates and the recent one suggest that a novel SbSHV strain emerged in Europe and the molecular findings imply its North American origin.

  9. Carbon exchange in Western Siberian watershed mires and implication for the greenhouse effect. A spatial temporal modeling approach

    Energy Technology Data Exchange (ETDEWEB)

    Borren, W.

    2007-01-19

    The vast watershed mires of Western Siberia formed a significant sink of carbon during the Holocene. Because of their large area these mires might play an important role in the carbon exchange between terrestrial ecosystems and the atmosphere. However, estimation of the Holocene and future carbon balance of whole Western Siberian mires is hampered by the lack of spatially resolved models. The main objective was to assess the carbon exchange fluxes of the mires using a 3-D dynamic approach. These exchange fluxes comprise the sequestration of carbon dioxide (CO2) by peat growth, the emission of methane (CH4) by anaerobic peat decay and the emission of CO2 by aerobic peat decay. From the detailed analysis of peat cores from different sites in the southern taiga of Western Siberia, it emerged that Holocene peat growth and carbon accumulation had different trends, caused by variations in vegetation succession. These differences were strongly influenced by the position in the landscape. Therefore, the effect of climatic change on mire development varied spatially. The indirect effects of climate change through local hydrology appeared to be more important than direct influences of changes in precipitation and temperature. Mire development is closely connected to hydrological dynamics. In the thesis a 3-D dynamic modeling approach is described that makes use of groundwater modeling. In successive timesteps peat growth and decay as well as mire type distribution were calculated, depending on hydrological conditions. The model was forced with a paleo-precipitation record to include variable climatic input. The model results show the Holocene development of a watershed mire from a few small spots to a contiguous mire landscape. As hydrology is the major limiting factor, the mire development is most sensitive to precipitation and evapotranspiration. Under unchanged conditions the mire will grow further, eventually reaching its maximum peat thickness around 11400 yr A.D. Under

  10. East Man,Global Winner

    Institute of Scientific and Technical Information of China (English)

    Wind Blew; Bai Yifeng

    2007-01-01

    @@ "The Global Human Settlement Environment Green Building Materials Award is a special award with a special significance.My staff and I feel so excited with this award.It is a special honor that means our independent brand,East Man Heath Paint,has received recognition in the international community.

  11. Forests of East Texas, 2014

    Science.gov (United States)

    Thomas J. Brandeis

    2015-01-01

    This resource update provides an overview of forest resources in east Texas derived from an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) Program at the Southern Research Station in cooperation with the Texas A&M Forest Service. These estimates are based on field data collected using the FIA annualized sample design and are...

  12. Forests of east Texas, 2015

    Science.gov (United States)

    Kerry J.W. Dooley

    2017-01-01

    This resource update provides an overview of forest resources in east Texas based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Southern Research Station (SRS) in cooperation with Texas A&M Forest Service. The 254 counties of Texas are consolidated into seven FIA survey units—Southeast (unit 1),...

  13. Forests of east Texas, 2013

    Science.gov (United States)

    K.J.W. Dooley; T.J. Brandeis

    2014-01-01

    This resource update provides an overview of forest resources in east Texas based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Southern Research Station in cooperation with the Texas A&M Forest Service. Forest resource estimates are based on field data collected using the FIA annualized sample design and...

  14. Great Explorers to the East.

    Science.gov (United States)

    Baker, Rosalie F., Ed.; Baker, Charles F. III, Ed.

    1990-01-01

    This issue of "Calliope," a world history magazine for young people is devoted to "Great Explorers of the East" and features articles on famous explorers of the eastern hemisphere. The following articles are included: "Ancient Egyptian Mariners"; "Alexander: The Great Reconciler"; "Marco Polo:…

  15. Great Explorers to the East.

    Science.gov (United States)

    Baker, Rosalie F., Ed.; Baker, Charles F. III, Ed.

    1990-01-01

    This issue of "Calliope," a world history magazine for young people is devoted to "Great Explorers of the East" and features articles on famous explorers of the eastern hemisphere. The following articles are included: "Ancient Egyptian Mariners"; "Alexander: The Great Reconciler"; "Marco Polo: Describing the World"; "By Water to India";…

  16. East African odontopygid millipedes 1

    DEFF Research Database (Denmark)

    Frederiksen, Sara B.; Enghoff, Henrik

    2012-01-01

    Five new species of the endemic East African genus Xystopyge are described: X. pelecys, X. frontieri, X. proplicatus, X. biacanthus, and X. zanzibarensis. Three are from the Eastern Arc Mountains, Tanzania, two are from the Usambara Mtns. and one is from the Uluguru Mtns. One further species is f...

  17. Morbidity from primary glaucoma and its gender-specific aspects amongst the population of Siberian industrial town

    Directory of Open Access Journals (Sweden)

    A. L. Onischenko

    2015-01-01

    Full Text Available Aim: To analyze visual morbidity attributable to primary glaucoma, its eight-year dynamics, and gender differences in Siberian industrial town inhabitants.Methods: Medical records (out-patient and in-patient departments from the database of the sectional information analysis center of Novokuznetsk Health Administration over an eight-year period (2004-2011 were studied. Individual patients diagnosed with primary glaucoma in 2004‑2011 were reviewed only.Results: Standardized primary glaucoma morbidity rate in men and women aged over 40 years was 3.5±0.3 ‰ and 2.6±0.26 ‰, respectively. Men were diagnosed with primary glaucoma earlier than women. In male residents aged over 70 years, primary glaucoma was found more often than in female residents. Male glaucoma patients required in-patient treatment more often than female patients. Primary glaucoma was diagnosed in men and women at 66.1±11.6 and 67.0±10.9 years (on average, respectively (U = 2.27, p = 0.023. 441 of 5424 patients (8.1 % diagnosed with glaucoma in 2004‑2011 subsequently died. The average age at death was 69.0±7.2 years, the median (25 %; 75 % was 71 years (66 years; 75 years. Patients who were diagnosed with primary glaucoma survived for 2.6±1.8 years. The median (25 %; 75 % was 2 years (1 year; 4 years. The distribution of the variable that characterized the difference between the age at death and the age of diagnosis making was abnormal (D = 0.151, p<0.001. Half of glaucoma patients died in the first two years after glaucoma has been diagnosed. Less than 20 % of patients (16 % men, 18 % women survived for ≥4 years after primary glaucoma diagnosis has been made. Conclusion: The analysis of morbidity and mortality rates as well as disability due to impaired vision is of great importance to health official and practitioners. Stably low glaucoma morbidity rate in Siberian industrial town inhabitants indicates a great lack of glaucoma specialists and forces

  18. Above-ground biomass and structure of pristine Siberian Scots pine forests as controlled by competition and fire.

    Science.gov (United States)

    Wirth, C; Schulze, E-D; Schulze, W; von Stünzner-Karbe, D; Ziegler, W; Miljukova, I M; Sogatchev, A; Varlagin, A B; Panvyorov, M; Grigoriev, S; Kusnetzova, W; Siry, M; Hardes, G; Zimmermann, R; Vygodskaya, N N

    1999-10-01

    The study presents a data set of above-ground biomass (AGB), structure, spacing and fire regime, for 24 stands of pristine Siberian Scots pine (Pinus sylvestris) forests with lichens (n = 20) or Vaccinium/mosses (n = 4) as ground cover, along four chronosequences. The stands of the "lichen" site type (LT) were stratified into three chronosequences according to stand density and fire history. Allometric equations were established from 90 sample trees for stem, coarse branch, fine branch, twig and needle biomass. The LT stands exhibited a low but sustained biomass accumulation until a stand age of 383 years. AGB reached only 6-10 kgdw m(-2) after 200 years depending on stand density and fire history compared to 20 kgdw m(-2) in the "Vaccinium" type (VT) stands. Leaf area index (LAI) in the LT stands remained at 0.5-1.5 and crown cover was 30-60%, whereas LAI reached 2.5 and crown cover was >100% in the VT stands. Although nearest-neighbour analyses suggested the existence of density-dependent mortality, fire impact turned out to have a much stronger effect on density dynamics. Fire scar dating and calculation of mean and initial fire return intervals revealed that within the LT stands differences in structure and biomass were related to the severity of fire regimes, which in turn was related to the degree of landscape fragmentation by wetlands. Self-thinning analysis was used to define the local carrying capacity for biomass. A series of undisturbed LT stands was used to characterise the upper self-thinning boundary. Stands that had experienced a moderate fire regime were positioned well below the self-thinning boundary in a distinct fire-thinning band of reduced major axis regression slope -0.26. We discuss how this downward shift resulted from alternating phases of density reduction by fire and subsequent regrowth. We conclude that biomass in Siberian Scots pine forests is strongly influenced by fire and that climate change will affect ecosystem

  19. Climatology of yellow sand (Asian sand, Asian dust or Kosa)in East Asia

    Institute of Scientific and Technical Information of China (English)

    Masatoshi; Yoshino

    2002-01-01

    In order to study climatology of yellow sand (Asian sand, Asian dust or Kosa) in EastAsia, secular fluctuation in China, Korea and Japan in the recent 30 years was presented. Thenumber of days with sand-dust storm at five stations in China-Hotan, Zhangye, Minqin, Jurhand Beijing, decreases a lot at the former three stations, but changed little at the latter two stations.Suggesting that the recent global warming is more evident in Xinjiang and Gansu, where the fre-quency of cold air invasions from the higher latitudes is decreasing. But, the eastern parts ofMongolia, inner Mongolia, and North China encounter stronger cyclones in early spring as a resultof global warming. These cyclones bring cold air from higher latitudes, causing severe duststorms. Secular variation in the annual days with sand-dust storms in China and Kosa days in Ko-rea and Japan show a parallel change with higher frequency from 1975 to 1985. This may be re-lated to the higher frequency of La Nina years. However, different tendency was shown in theperiod from 1986 to 1996. Since 1996 or 1997, a sharp increase is clear, which may be caused bythe developed cyclones in East Asia as well as human activities, and stronger land degradationunder La Nina conditions. Anomalies of the total number of stations with Kosa days were dis-cussed in accordance with some synoptic meteorological conditions such as the differences be-tween Siberian anticyclone and Aleutian cyclone center at 500 hPa level during the previous winter.

  20. Funding problems threaten Middle East's synchrotron

    CERN Multimedia

    McCabe, H

    1999-01-01

    Scientists will tour the Middle East to try to raise support for the Synchrotron radiation for Experimental Science and Applications in the Middle East project. The plan is to dismantle and move a decommissioned synchrotron from Berlin to the Middle East where scientists of any nationality would be able to use it (3 paragraphs).

  1. Karaoke and Interpersonal Communication in East Asia.

    Science.gov (United States)

    Ma, Ringo

    An exploratory study investigated the interpersonal meaning of karaoke to its participants in East Asia. Current research suggests that the popularity of karaoke in East Asia is associated with the cultural value of harmony and the indirect mode of communication in this region. Subjects, 51 East Asian undergraduate-level students who had…

  2. Experiencing the New Geography in East Germany.

    Science.gov (United States)

    Mai, Uli; Burpee, Peter

    1996-01-01

    Considers the difficulties experienced by the East German School system adjusting to a more progressive educational philosophy. Specifically, contrasts the traditional East German geography instruction (focused solely on physical geography) with the West German emphasis on social issues and problem solving. Many East German instructors distrust…

  3. The mystery of Bunge Land (New Siberian Archipelago): implications for its formation based on palaeoenvironmental records, geomorphology, and remote sensing

    Science.gov (United States)

    Schirrmeister, Lutz; Grosse, Guido; Kunitsky, Viktor V.; Fuchs, Margret C.; Krbetschek, Matthias; Andreev, Andrei A.; Herzschuh, Ulrike; Babyi, Olga; Siegert, Christine; Meyer, Hanno; Derevyagin, Alexander Y.; Wetterich, Sebastian

    2010-12-01

    Multiproxy datasets (geocryology, geochronology, sedimentology, palaeo-ecology) from permafrost exposures were used together with land surface information based on satellite imagery and thematic maps in order to reconstruct the Lateglacial to Holocene landscape and environmental dynamics of Bunge Land (Zemlya Bunge). This area of little relief, situated in the New Siberian Archipelago, connects the geomorphologically well-structured islands of Kotel'ny and Fadeevsky. A buried thermokarst landscape was found in the northwest region of the Bunge Land low terrace sand plain, whereas the Bunge Land high terrace seems to be an exposed residue of a similar late Quaternary thermokarst landscape. That is confirmed especially by radiocarbon accelerator mass spectrometry and optically stimulated luminescence age determinations, and by pollen analyses. Palaeogeographically, the late Pleistocene periglacial landscape and sedimentation of Bunge Land was closely connected to Kotel'ny and Fadeevsky; only later on seismotectonical block movements resulted in reshaping parts of Bunge Land. The Bunge Land low terrace area first subsided and the original landscape there was destroyed by marine inundation, followed by marine sedimentation. Subsequent block heave of the low terrace region exposed a vast sheet of marine sands which is continuously surficially reworked by aeolian processes, while the original alluvial plain landscape in the high terrace area was preserved and started degrading only by early Holocene thermokarst development. The studied exposures contain one of the northernmost (74.88°N) environmental records for the late Pleistocene-Holocene transition in the Eurasian Arctic.

  4. The effect of microbial inocula on the growth of black locust, Siberian elm and silver maple seedlings

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    Hajnal-Jafari Timea

    2014-01-01

    Full Text Available Growth and development of forest plants depend mostly on the soil microbial activity since no mineral or organic fertilizers are applied. Microbial processes can be activated and conditions for plants development improved with the introduction of selected microorganisms in the soil. With the aim of obtaining quality planting material in a shorter period of time, the effects of Azotobacter chroococcum and Streptomyces sp. on the early growth of black locust (Robinia pseudoacacia, Siberian elm (Ulmus pumila and silver-leaf maple (Acer dasycarpum were investigated in this study. Microorganisms were applied individually and in a mixture (1:1. Plant height was measured on the 90th, 120th and 180th day after planting. Plant diameter, as well as the number of actinomycetes and azotobacters was measured at the end of the vegetation period (180 days after planting. Applied microorganisms had a positive effect on the seedling height in all three plant species, with the best effect found in the black locust. Effectiveness of applied microorganisms on seedling diameter was the highest in the silver-leaf maple. The largest number of azotobacters was found in the rhizosphere of black locust. Number of microorganisms from both groups was increased in the inoculated variants. [Projekat Ministarstva nauke Republike Srbije, br. III 43002

  5. Effects of Pediococcus pentosaceus as a probiotic on intestinal microbiota and body composition of Siberian sturgeon, Acipenser baerii Brandt, 1869

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    Fateme Moslehi

    2016-02-01

    Full Text Available An eight-week experiment was carried out to determine the effects of dietary Pediococcus pentosaceus as probiotic on the body composition and gut microbiota of Siberian sturgeon, Acipenser baerii. A total of 180 fish with mean body weight of 143±0.01g were randomly distributed into 12 200L fiberglass tanks as four treatments with three replicates, including groups fed with diet containing 2×107, 2×108 and 2×109 CFU g-1 of P. pentosaceus and probiotic-free as control group. Body composition of treatment groups was not influenced by P. pentosaceus except for fat and moisture. The bacteria had a significant colonization in the intestine of fish fed with supplemented diet with P. pentosaceus. High level of acid lactic bacterial load was found in the treatment fed with highest amount of the probiotic i.e. 2×109 CFU g-1. The results showed that application of P. pentosaceus has positive effect on the body composition and intestinal microflora of the A. baerii.

  6. [Distribution and activity of microorganisms in the deep repository for liquid radioactive waste at the Siberian Chemical Combine].

    Science.gov (United States)

    Nazina, T N; Luk'ianova, E A; Zakharova, E V; Ivoĭlov, V S; Poltaraus, A B; Kalmykov, S N; Beliaev, S S; Zubkov, A A

    2006-01-01

    The physicochemical conditions, composition of microbial communities, and the rates of anaerobic processes in the deep sandy horizons used as a repository for liquid radioactive wastes (LRW) at the Siberian Chemical Combine (Seversk, Tomsk oblast), were studied. Formation waters from the observation wells drilled into the production horizons of the radioactive waste disposal site were found to be inhabited by microorganisms of different physiological groups, including aerobic organotrophs, anaerobic fermentative, denitrifying, sulfate-reducing, and methanogenic bacteria. The density of microbial population, as determined by cultural methods, was low and usually did not exceed 10(4) cells/ml. Enrichment cultures of microorganisms producing gases (hydrogen, methane, carbon dioxide, and hydrogen sulfide) and capable of participation in the precipitation of metal sulfides were obtained from the waters of production horizons. The contemporary processes of sulfate reduction and methanogenesis were assayed; the rates of these terminal processes of organic matter destruction were found to be low. The denitrifying bacteria from the underground repository were capable of reducing the nitrates contained in the wastes, provided sources of energy and biogenic elements were available. Biosorption of radionuclides by the biomass of aerobic bacteria isolated from groundwater was demonstrated. The results obtained give us insight into the functional structure of the microbial community inhabiting the waters of repository production horizons. This study indicates that the numbers and activity of microbial cells are low both inside and outside the zone of radioactive waste dispersion, in spite of the long period of waste discharge.

  7. Modeling the large-scale effects of surface moisture heterogeneity on wetland carbon fluxes in the West Siberian Lowland

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    T. J. Bohn

    2013-10-01

    Full Text Available We used a process-based model to examine the role of spatial heterogeneity of surface and sub-surface water on the carbon budget of the wetlands of the West Siberian Lowland over the period 1948–2010. We found that, while surface heterogeneity (fractional saturated area had little overall effect on estimates of the region's carbon fluxes, sub-surface heterogeneity (spatial variations in water table depth played an important role in both the overall magnitude and spatial distribution of estimates of the region's carbon fluxes. In particular, to reproduce the spatial pattern of CH4 emissions recorded by intensive in situ observations across the domain, in which very little CH4 is emitted north of 60° N, it was necessary to (a account for CH4 emissions from unsaturated wetlands and (b use spatially varying methane model parameters that reduced estimated CH4 emissions in the northern (permafrost half of the domain (and/or account for lower CH4 emissions under inundated conditions. Our results suggest that previous estimates of the response of these wetlands to thawing permafrost may have overestimated future increases in methane emissions in the permafrost zone.

  8. Development prospects for Bazhenov formation bituminous claystones in the southeast of the West Siberian Plate (Tomsk Region)

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    Belozerov, V. B.; Baranov, V. E.; Dmitriev, A. Y.

    2015-02-01

    The article considers the use of time-tested bituminous shale development technologies in the southeast of the West Siberian Plate (Tomsk Region). A research target is the bituminous claystones of the Bazhenov formation. The Bazhenov formation was divided into stratigraphic units, and the sequence of forming these units within the territory under study was restored on the basis of the peculiarities of the Bazhenov formation section structure with gamma-ray logging data. The joint analysis of logs (gamma-ray logging, resistivity logging, SP logging, neutron gamma-ray logging, induction logging) and core data revealed the wide development of carbonatization processes in the lower stratigraphic units of the Bazhenov formation, whereas the upper, most bituminous units do not have the signs of carbonatization. It is a favorable factor for using the existing technologies of producing hydrocarbons from analogous sedimentary deposits. Considering the degree of lithological disconnection of an oilbearing object from adjacent reservoir formations allows making a conclusion that the application of the existing technologies for developing bituminous claystones can be implemented only in the insignificant territory of the area under study where the Bazhenov formation overlies Georgiev formation claystones being over 8 meters thick. To develop the oil and gas potential of the Bazhenov formation in other territories, there will be a need for new technologies that allow forming a fracture-cavernous matrix in a carbonate rock.

  9. Abundance, distribution and conservation status of Siberian ibex, Marco Polo and Blue sheep in Karakoram-Pamir mountain area

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    Babar Khan

    2016-07-01

    Full Text Available This study was carried out to investigate abundance, distribution, structure and conservation status of three major ungulate species viz., Capra sibirica, Pseudois nayaur and Ovis ammon polii, in the Karakoram-Pamir mountain area between China and Pakistan. Results showed that the entire study area had a scattered but worthwhile population of Siberian ibex, Blue sheep and Marco Polo sheep, except Khunjerab Pass, Koksil-Pateshek and Barkhun areas of Khunjerab National Park (KNP. Large groups of Blue sheep were sighted in Shimshal and Barkhun valleys (KNP but it did not show up in the Muztagh part of Taxkorgan Nature Reserve (TNR in China. Despite scarcity of natural vegetation and extreme climate, estimated abundance of ibex and Marco Polo sheep was not different from that in Protected Areas of Nepal, China, and India, except for Blue sheep. Marco Polo sheep, Blue sheep and Snow leopard roam across international borders among China, Pakistan and other adjacent countries. Illegal hunting and poaching, removal of natural vegetation for fodder and firewood, and over grazing of pastures by livestock were main habitat issues whereas, border fencing for security reasons, has been a major impediment restricting free movement of the wildlife across international borders. A science based conservation and development strategy is proposed to restore viable wildlife populations and maintain ecological flows of Karakoram Pamir Mountains to benefit both the wild species and the local human communities.

  10. Labile pyrogenic dissolved organic carbon in major Siberian Arctic rivers: Implications for wildfire-stream metabolic linkages

    Science.gov (United States)

    Myers-Pigg, Allison N.; Louchouarn, Patrick; Amon, Rainer M. W.; Prokushkin, Anatoly; Pierce, Kayce; Rubtsov, Alexey

    2015-01-01

    burning produces a spectrum of thermally altered materials that releases pyrogenic carbon (PyC) to terrestrial, atmospheric, and aquatic systems. Most studies focus on the refractory end of the PyC spectrum, derived from middle- to high-temperature combustion. Low-temperature PyC is produced during wildfires and has been found to be particularly labile and water soluble. Here we find that in each of the major Siberian watersheds, low-temperature fire-derived biomarkers are present in detectable concentrations during all flow regimes of the 2004-2006 sampling period, confirming that PyC is an intrinsic component of the dissolved organic carbon (DOC) pool mobilized by hydrologic events. Gymnosperm combustion, from the southern portions of these watersheds, is the primary source of this Py-DOC input. Using first-order degradation rates and transit times of water through these rivers, about half of the total estimated flux of this material may be remineralized during transport from fire source to river mouth (20-40 days), demonstrating the input of a labile source of PyC to these watersheds.

  11. Thermal acclimation and nutritional history affect the oxidation of different classes of exogenous nutrients in Siberian hamsters, Phodopus sungorus.

    Science.gov (United States)

    McCue, Marshall D; Voigt, Christian C; Jefimow, Małgorzata; Wojciechowski, Michał S

    2014-11-01

    During acclimatization to winter, changes in morphology and physiology combined with changes in diet may affect how animals use the nutrients they ingest. To study (a) how thermal acclimation and (b) nutritional history affect the rates at which Siberian hamsters (Phodopus sungorus) oxidize different classes of dietary nutrients, we conducted two trials in which we fed hamsters one of three (13) C-labeled compounds, that is, glucose, leucine, or palmitic acid. We predicted that under acute cold stress (3 hr at 2°C) hamsters previously acclimated to cold temperatures (10°C) for 3 weeks would have higher resting metabolic rate (RMR) and would oxidize a greater proportion of dietary fatty acids than animals acclimated to 21°C. We also investigated how chronic nutritional stress affects how hamsters use dietary nutrients. To examine this, hamsters were fed four different diets (control, low protein, low lipid, and low-glycemic index) for 2 weeks. During cold challenges, hamsters previously acclimated to cold exhibited higher thermal conductance and RMR, and also oxidized more exogenous palmitic acid during the postprandial phase than animals acclimated to 21°C. In the nutritional stress trial, hamsters fed the low protein diet oxidized more exogenous glucose, but not more exogenous palmitic acid than the control group. The use of (13) C-labeled metabolic tracers combined with breath testing demonstrated that both thermal and nutritional history results in significant changes in the extent to which animals oxidize dietary nutrients during the postprandial period.

  12. Short photoperiod-induced decrease of histamine H3 receptors facilitates activation of hypothalamic neurons in the Siberian hamster.

    Science.gov (United States)

    Barrett, P; van den Top, M; Wilson, D; Mercer, J G; Song, C K; Bartness, T J; Morgan, P J; Spanswick, D

    2009-08-01

    Nonhibernating seasonal mammals have adapted to temporal changes in food availability through behavioral and physiological mechanisms to store food and energy during times of predictable plenty and conserve energy during predicted shortage. Little is known, however, of the hypothalamic neuronal events that lead to a change in behavior or physiology. Here we show for the first time that a shift from long summer-like to short winter-like photoperiod, which induces physiological adaptation to winter in the Siberian hamster, including a body weight decrease of up to 30%, increases neuronal activity in the dorsomedial region of the arcuate nucleus (dmpARC) assessed by electrophysiological patch-clamping recording. Increased neuronal activity in short days is dependent on a photoperiod-driven down-regulation of H3 receptor expression and can be mimicked in long-day dmpARC neurons by the application of the H3 receptor antagonist, clobenproprit. Short-day activation of dmpARC neurons results in increased c-Fos expression. Tract tracing with the trans-synaptic retrograde tracer, pseudorabies virus, delivered into adipose tissue reveals a multisynaptic neuronal sympathetic outflow from dmpARC to white adipose tissue. These data strongly suggest that increased activity of dmpARC neurons, as a consequence of down-regulation of the histamine H3 receptor, contributes to the physiological adaptation of body weight regulation in seasonal photoperiod.

  13. Exogenous insulin enhances humoural immune responses in short-day, but not long-day, Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    Garcia, Nicholas W; Greives, Timothy J; Zysling, Devin A; French, Susannah S; Chester, Emily M; Demas, Gregory E

    2010-07-22

    Many animals experience marked seasonal fluctuations in environmental conditions. In response, animals display adaptive alterations in physiology and behaviour, including seasonal changes in immune function. During winter, animals must reallocate finite energy stores from relatively costly, less exigent systems (e.g. reproduction and immunity) to systems critical for immediate survival (e.g. thermoregulation). Seasonal changes in immunity are probably mediated by neuroendocrine factors signalling current energetic state. One potential hormonal candidate is insulin, a metabolic hormone released in response to elevated blood glucose levels. The aim of the present study was to explore the potential role of insulin in signalling energy status to the immune system in a seasonally breeding animal, the Siberian hamster (Phodopus sungorus). Specifically, exogenous insulin was administered to male hamsters housed in either long 'summer-like' or short 'winter-like' days. Animals were then challenged with an innocuous antigen and immune responses were measured. Insulin treatment significantly enhanced humoural immune responses in short, but not long days. In addition, insulin treatment increased food intake and decreased blood glucose levels across photoperiodic treatments. Collectively, these data support the hypothesis that insulin acts as an endocrine signal integrating seasonal energetic changes and immune responses in seasonally breeding rodents.

  14. Hemato-Immunological Responses and Disease Resistance in Sib