Impact of raized bogs on export of carbon and river water chemical composition in Western Siberia

NASA Astrophysics Data System (ADS)

Voistinova, Elena

2010-05-01

Bogs play an important role in functioning of the biosphere. Specific geochemical environment of the bogs results in formation of the special biogeochemical cycle of the elements. Processes of decay and transformation of organic material define the reductive conditions of bog water, form and migratory mobility of the chemical elements. Particular interest in recent years is aroused by the question of content and dynamics of the carbon in bog and river water according to indicated natural and climatic changes on the territory. The most important parts of the carbon balance in bog ecosystems together with processes of exhalation from deposit surface in the form of CO2 is its export with river water. The results of research carried out in scientific station "Vasyugansky" in south taiga subzone of Western Siberia showed that chemical composition of raised bog water includes high amounts of total iron (2,13 mg/l), ammonium ions (5,33 mg/l), humic and fulvic acids (5,21 mg/l and 45,8 mg/l), dissolved organic carbon (69,1 mg/l), COD (236,93 mgO/l), there are low mineralization and indicators of pH. Carbon comes in bog water in organic compounds: carboxylic acids, phenols, aromatic and paraffin hydrocarbons, organic phosphates, phthalates and other compounds. Formation of river waters composition in the Western Siberia takes place in the following context: high level of bogged river catchments (sometimes up to 70%), excess humidification and low heat provision. Basing on the results of study of hydrochemical runoff in small and medium rivers with different levels of bogged in river catchments (Chaya, Bakchar, Klyuch, Gavrilovka) it was noted that raised bog influence on river waters chemical composition shows in ion runoff decrease, organic substances runoff increase, increase of amounts of total iron, ammonium irons and water pH indicators decrease. Study of humic matters migration is very important in the context of formation of flexible complexes of humic and fulvic

A stonefly species extinct in Europe (Taeniopteryx araneoides Klapalek, 1902, Taeniopterygidae, Plecoptera) is thriving in the Irtysh River in West Siberia and North Kazakhstan.

PubMed

Kosterin, Oleg E; Akimbekova, Nazymgul; Dubatolov, Vladimir V; Sivec, Ignac

2017-03-27

Taeniopteryx araneoides Klápalek, 1902, a stonefly species with brachypterous males, known historically from the Danube, Elbe, and Dniester rivers, but considered to be extinct at least in Europe for more than a century. This species has also been doubtfully reported from Krasnoyarsk, Central Siberia. However, we report this species to be still thriving in the Irtysh River at the cities of Omsk (West Siberia, Russia) and Pavlodar (North Kazakhstan). The occurrence of this species reported least fifty years ago from the Yenisey River at Krasnoyarsk, Russia is considered possible. Unlike the widespread Palaearctic T. nebulosa (Linnaeus, 1758) that occurs in a broad range of stream types, T. araneoides is a potomon species, apparently confined to large rivers. In this habitat, it appears vulnerable to anthropogenic impacts and may be unable to compete with T. nebulosa. The construction of dams and reservoirs has apparently extirpated T. araneoides from most of its former geographical range.

Dragon Lake, Siberia

NASA Technical Reports Server (NTRS)

2002-01-01

Nicknamed 'Dragon Lake,' this body of water is formed by the Bratskove Reservoir, built along the Angara river in southern Siberia, near the city of Bratsk. This image was acquired in winter, when the lake is frozen. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on December 19, 1999. This is a natural color composite image made using blue, green, and red wavelengths. Image provided by the USGS EROS Data Center Satellite Systems Branch

Taenia sp. in human burial from Kan River, East Siberia.

PubMed

Slepchenko, Sergey Mikhailovich; Ivanov, Sergey Nikolaevich; Vybornov, Anton Vasilevich; Alekseevich, Tsybankov Alexander; Sergeyevich, Slavinsky Vyacheslav; Lysenko, Danil Nikolaevich; Matveev, Vyacheslav Evgenievich

2017-05-01

We present an arhaeoparasitological analysis of a unique burial from the Neftprovod II burial ground in East Siberia, which dated from the Bronze Age. Analysis of a sediment sample from the sacral region of the pelvis revealed the presence of Taenia sp. eggs. Because uncooked animal tissue is the primary source of Taenia, this indicated that the individual was likely consuming raw or undercooked meat of roe deer, red deer, or elk infected with Taenia. This finding represents the oldest case of a human infected with Taenia sp. from Eastern Siberia and Russia.

Trace elements transport in western Siberia rivers across a permafrost gradient

NASA Astrophysics Data System (ADS)

Pokrovsky, O. S.; Manasypov, R. M.; Loiko, S.; Krickov, I. A.; Kopysov, S. G.; Kolesnichenko, L. G.; Vorobyev, S. N.; Kirpotin, S. N.

2015-11-01

Towards a better understanding of trace element transport in permafrost-affected Earth surface environments, we sampled ∼ 60 large and small rivers (< 100 to ≤ 150 000 km2 watershed area) of Western Siberia Lowland (WSL) during spring flood and summer and winter base-flow across a 1500 km latitudinal gradient covering continuous, discontinuous, sporadic and permafrost-free zones. Analysis of ∼ 40 major and trace elements in dissolved (< 0.45 μm) fraction allowed establishing main environmental factors controlling the transport of metals and trace elements in rivers of this environmentally important region. No statistically significant effect of the basin size on most TE concentration was evidenced. Three category of trace elements were distinguished according to their concentration - latitude pattern: (i) increasing northward in spring and winter (Fe, Al, Ga (only winter), Ti (only winter), REEs, Pb, Zr, Hf, Th (only winter)), linked to leaching from peat and/or redox processes and transport in the form of Fe-rich colloids, (ii) decreasing northward during all seasons (Sr, Mo, U, As, Sb) marking the underground water influence of river feeding and (iii) elements without distinct trend from S to N whose variations within each latitude range were higher than the difference between latitudinal ranges (B, Li, Ti (except summer), Cr, V, Mn, Zn, Cd, Cs, Hf, Th). In addition to these general features, specific, northward increase during spring period was mostly pronounced for Fe, Mn, Co, Zn and Ba and may stem from a combination of enhanced leaching from the topsoil and vegetation and bottom waters of the lakes (spring overturn). A spring time northward decrease was observed for Ni, Cu, Zr, Rb. The southward increase in summer was strongly visible for Fe, Ni, Ba, Rb and V, probably due to peat/moss release (Ni, Ba, Rb) or groundwater feeding (Fe, V). The Principal Component Analysis demonstrated two main factors potentially controlling the ensemble of TE

Enzymatic regulation of organic matter metabolism in Siberia's Kolyma River Watershed

NASA Astrophysics Data System (ADS)

Mann, P. J.; Sobczak, W.; Vonk, J. E.; Davydova, A.; Schade, J.; Bulygina, E.; Davydov, S.; Zimov, N.; Holmes, R. M.

2012-04-01

Arctic soils contain vast amounts of ancient organic carbon stored in permafrost that can be unlocked and remobilised via permafrost thaw and bacterial degradation. The mechanisms regulating the release and fate of this carbon are important to understand if we wish to predict future changes in the global carbon cycle. Microbial communities release enzymes into the environment (ectoenzymes) as a means of degrading organic matter and to acquire carbon, nitrogen and phosphorus for assimilation. We measured potential activities of a suite of ectoenzymes within surface waters collected from a range of streams and rivers throughout the Kolyma River basin, Siberia. Ectoenzyme activities were additionally measured in Kolyma river waters collected at three distinct periods of the hydrograph (under-ice, freshet and summer conditions). Seven enzymes were studied allowing bacterial requirements for a wide range of compounds including lignin, carbohydrates, proteins and cellulose to be assessed. Concurrent measurements of DOC lability were conducted using biological oxygen demand assays conducted over 5 days (BOD). Phenol oxidase activity was found to strongly correlate to BOD (r2=0.68) and stream CO2 concentration (r2=0.76) across all of the study sites, suggesting the rate of phenolic degradation may be a controlling factor in organic carbon metabolism. The activity rate in ectoenzymes that catalyze phosphate, lignin and carbon substrates varied significantly within the Kolyma river over the hydrograph, suggesting that seasonal changes in organic matter composition may also shift the limiting resource for bacterial degradation. Extremely high activity rates in ectoenzymes that catalyze lignin, chitin, cellulose and proteins were measured in waters draining permafrost ice complexes. It is apparent that organic carbon is continually processed throughout the stream network, and that its ultimate fate is linked to organic matter composition. We demonstrate that organic carbon

Enzymatic Regulation of Organic Matter Metabolism in Siberia's Kolyma River Watershed

NASA Astrophysics Data System (ADS)

Mann, P. J.; Sobczak, W. V.; Vonk, J. E.; Davydova, A.; Schade, J. D.; Bulygina, E. B.; Davydov, S.; Zimov, N.; Holmes, R. M.

2011-12-01

Arctic soils contain vast amounts of ancient organic carbon locked up in permafrost. This organic matter can be unlocked via permafrost thaw and bacterial processing. Microbial communities release enzymes into the environment (ectoenzymes) as a means of degrading organic matter and to acquire carbon, nitrogen and phosphorus for assimilation. Limited ectoenzyme production, or unfavourable in-situ conditions (e.g. temperature, oxygen) can limit degradation of permafrost on land. Environmental conditions may become more favourable for bacterial degradation as carbon compounds are released from permafrost into Arctic streams and rivers. We measured the potential activities of a suite of ectoenzymes within surface waters collected from a range of streams and rivers throughout the Kolyma River basin, Siberia. Ectoenzyme activities were additionally measured in Kolyma river waters collected at three distinct periods of the hydrograph (under-ice, freshet and summer conditions). In total, seven enzymes were studied allowing bacterial requirements for a wide range of compounds including lignin, carbohydrates, proteins and cellulose to be assessed. To investigate the lability of the carbon pool within these waters, we measured the biological oxygen demand over 5 days (BOD). Significant correlations were observed between phenol oxidase activity and BOD across all of the study sites, suggesting the rate of phenolic degradation may be a controlling factor in organic carbon metabolism. The activity rate in ectoenzymes that catalyze phosphate, lignin and carbon substrates varied significantly within the Kolyma river over the hydrograph, indicating that seasonal changes in organic matter composition may also shift the limiting resource for bacterial degradation. High activity rates in ectoenzymes that catalyze lignin, chitin, cellulose and proteins were measured in waters draining permafrost ice complexes. These results suggest that organic carbon is continually processed

Expedition to Siberia: A Firsthand Account

NASA Technical Reports Server (NTRS)

Ranson, Jon; Kharuk, Slava; Howl, Joanne

2007-01-01

Nowhere on Earth is warming faster than the Arctic. In northern Siberia, average temperatures have risen 3-5 deg F over the past 30 years, whereas the worldwide average increase in that time is 1 deg F. Betweeen July 28 and August 12, 2007, a small international team of remote sensing and forest ecosystem scientists from NASA and Russia's Academy of Science set off on a three-week scientific expedition through the heart of the remote, wild forests of Siberia. They traveled southward down the Kochechum River observing the gradual transition from tundra to taiga, taking inventory of plant species along the way, and making ground-truth measurements to validate data being collected by several NASA satellites flying 700 kilometers overhead.

Influence of atmospheric internal variability on the long-term Siberian water cycle during the past 2 centuries

NASA Astrophysics Data System (ADS)

Oshima, Kazuhiro; Ogata, Koto; Park, Hotaek; Tachibana, Yoshihiro

2018-05-01

River discharges from Siberia are a large source of freshwater into the Arctic Ocean, whereas the cause of the long-term variation in Siberian discharges is still unclear. The observed river discharges of the Lena in the east and the Ob in the west indicated different relationships in each of the epochs during the past 7 decades. The correlations between the two river discharges were negative during the 1980s to mid-1990s, positive during the mid-1950s to 1960s, and became weak after the mid-1990s. More long-term records of tree-ring-reconstructed discharges have also shown differences in the correlations in each of the epochs. It is noteworthy that the correlations obtained from the reconstructions tend to be negative during the past 2 centuries. Such tendency has also been obtained from precipitations in observations, and in simulations with an atmospheric general circulation model (AGCM) and fully coupled atmosphere-ocean GCMs conducted for the Fourth Assessment Report of the IPCC. The AGCM control simulation further demonstrated that an east-west seesaw pattern of summertime large-scale atmospheric circulation frequently emerges over Siberia as an atmospheric internal variability. This results in an opposite anomaly of precipitation over the Lena and Ob and the negative correlation. Consequently, the summertime atmospheric internal variability in the east-west seesaw pattern over Siberia is a key factor influencing the long-term variation in precipitation and river discharge, i.e., the water cycle in this region.

Ablation of ghrelin receptor in leptin-deficient ob/ob mice has paradoxical effects on glucose homeostasis when compared with ablation of ghrelin in ob/ob mice.

PubMed

Ma, Xiaojun; Lin, Yuezhen; Lin, Ligen; Qin, Guijun; Pereira, Fred A; Haymond, Morey W; Butte, Nancy F; Sun, Yuxiang

2012-08-01

The orexigenic hormone ghrelin is important in diabetes because it has an inhibitory effect on insulin secretion. Ghrelin ablation in leptin-deficient ob/ob (Ghrelin(-/-):ob/ob) mice increases insulin secretion and improves hyperglycemia. The physiologically relevant ghrelin receptor is the growth hormone secretagogue receptor (GHS-R), and GHS-R antagonists are thought to be an effective strategy for treating diabetes. However, since some of ghrelin's effects are independent of GHS-R, we have utilized genetic approaches to determine whether ghrelin's effect on insulin secretion is mediated through GHS-R and whether GHS-R antagonism indeed inhibits insulin secretion. We investigated the effects of GHS-R on glucose homeostasis in Ghsr-ablated ob/ob mice (Ghsr(-/-):ob/ob). Ghsr ablation did not rescue the hyperphagia, obesity, or insulin resistance of ob/ob mice. Surprisingly, Ghsr ablation worsened the hyperglycemia, decreased insulin, and impaired glucose tolerance. Consistently, Ghsr ablation in ob/ob mice upregulated negative β-cell regulators (such as UCP-2, SREBP-1c, ChREBP, and MIF-1) and downregulated positive β-cell regulators (such as HIF-1α, FGF-21, and PDX-1) in whole pancreas; this suggests that Ghsr ablation impairs pancreatic β-cell function in leptin deficiency. Of note, Ghsr ablation in ob/ob mice did not affect the islet size; the average islet size of Ghsr(-/-):ob/ob mice is similar to that of ob/ob mice. In summary, because Ghsr ablation in leptin deficiency impairs insulin secretion and worsens hyperglycemia, this suggests that GHS-R antagonists may actually aggravate diabetes under certain conditions. The paradoxical effects of ghrelin ablation and Ghsr ablation in ob/ob mice highlight the complexity of the ghrelin-signaling pathway.

Eastern Siberia terrain intelligence

USGS Publications Warehouse

,

1942-01-01

The following folio of terrain intelligence maps, charts and explanatory tables represent an attempt to bring together available data on natural physical conditions such as will affect military operations in Eastern Siberia. The area covered is the easternmost section of the U.S.S.R.; that is the area east of the Yenisei River. Each map and accompanying table is devoted· to a specialized set of problems; together they cover such subjects as geology, construction materials, mineral fuels, terrain, water supply, rivers and climate. The data is somewhat generalized due to the scale of treatment as well as to the scarcity of basic data. Each of the maps are rated as to reliability according to the reliability scale on the following page. Considerable of the data shown is of an interpretative nature, although precise data from literature was used wherever possible. The maps and tables were compiled  by a special group from the United States Geological Survey in cooperation with the Intelligence Branch of the Office, Chief of Engineers, War Department.

Ablation of ghrelin receptor in leptin-deficient ob/ob mice has paradoxical effects on glucose homeostasis when compared with ablation of ghrelin in ob/ob mice

USDA-ARS?s Scientific Manuscript database

The orexigenic hormone ghrelin is important in diabetes because it has an inhibitory effect on insulin secretion. Ghrelin ablation in leptin-deficient ob/ob (Ghrelin(-/-):ob/ob) mice increases insulin secretion and improves hyperglycemia. The physiologically relevant ghrelin receptor is the growth ...

Effect of leptin administration on myelination in ob/ob mouse cerebrum after birth.

PubMed

Hashimoto, Ryuju; Matsumoto, Akihiro; Udagawa, Jun; Hioki, Kyoji; Otani, Hiroki

2013-01-09

Brain weight and size are known to be reduced in adult leptin-deficient Lep/Lep (OB) mice when compared with the wild-type (+/+) mice (C57BL/6: B6). We here analyzed leptin's effects on myelination by examining morphometrically the myelin sheath (MS) in the cerebrum of postnatal day (P) 14 and P28 OB that had received leptin 1 nmol/capita/day from P7 to P14 or P28 (OB+lep), in comparison with OB and B6. We examined myelin basic protein (MBP) mRNA levels and the differentiation of oligodendrocytes by comparing the number of oligodendrocyte precursor cells (OPCs) and the mature oligodendrocytes in the cerebrum between OB, OB+lep, and B6 on P14 and P28. MBP-mRNA expression was lower in OB than in B6 on P14 and P28. On P14, it was higher in OB+lep than in OB but was still lower than in B6, whereas on P28 it was even higher in OB+lep than in B6. On P28, the radii of myelinated axons were larger in OB than in B6 and OB+lep. The MS on P28 was significantly thinner in OB than in B6, but there was no significant difference between OB and OB+lep. There were significantly fewer mature oligodendrocytes in OB and OB+lep than in B6 on P28, whereas on P14 there were significantly fewer OPCs in OB and OB+lep than in B6. Our results suggested that leptin regulates the myelination of oligodendrocytes and that the replenishment of leptin in OB recovered myelination but did not affect the differentiation of OPCs from P7 to P28.

Genetically obese (ob/ob) mice are resistant to the lethal effects of thioacetamide hepatotoxicity

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

Won, Young-Suk; Song, Ji-Won; Lim, Jong-Hwan

Obesity increases the risk of chronic liver diseases, including viral hepatitis, alcohol-induced liver disease, and non-alcoholic steatohepatitis. In this study, we investigated the effects of obesity in acute hepatic failure using a murine model of thioacetamide (TA)-induced liver injury. Genetically obese ob/ob mice, together with non-obese ob/+ littermates, were subjected to a single intraperitoneal injection of TA, and examined for signs of hepatic injury. ob/ob mice showed a significantly higher survival rate, lower levels of serum alanine aminotransferase and aspartate aminotransferase, and less hepatic necrosis and apoptosis, compared with ob/+ mice. In addition, ob/ob mice exhibited significantly lower levels ofmore » malondialdehyde and significantly higher levels of glutathione and antioxidant enzyme activities compared with their ob/+ counterparts. Bioactivation analyses revealed reduced plasma clearance of TA and covalent binding of [{sup 14}C]TA to liver macromolecules in ob/ob mice. Together, these data demonstrate that genetically obese mice are resistant to TA-induced acute liver injury through diminished bioactivation of TA and antioxidant effects. - Highlights: • ob/ob mice are resistant to lethal doses of thioacetamide, compared to ob/+ mice. • ob/ob mice show reduced oxidative stress and enhanced antioxidant enzyme activity. • ob/ob mice exhibit diminished bioactivation of thioacetamide.« less

Sirtuin-2 Regulates Sepsis Inflammation in ob/ob Mice

PubMed Central

Wang, Xianfeng; Buechler, Nancy L.; Martin, Ayana; Wells, Jonathan; Yoza, Barbara; McCall, Charles E.; Vachharajani, Vidula

2016-01-01

Objective Obesity increases morbidity and resource utilization in sepsis patients. Sepsis transitions from early/hyper-inflammatory to late/hypo-inflammatory phase. Majority of sepsis-mortality occurs during the late sepsis; no therapies exist to treat late sepsis. In lean mice, we have shown that sirtuins (SIRTs) modulate this transition. Here, we investigated the role of sirtuins, especially the adipose-tissue abundant SIRT-2 on transition from early to late sepsis in obese with sepsis. Methods Sepsis was induced using cecal ligation and puncture (CLP) in ob/ob mice. We measured microvascular inflammation in response to lipopolysaccharide/normal saline re-stimulation as a “second-hit” (marker of immune function) at different time points to track phases of sepsis in ob/ob mice. We determined SIRT-2 expression during different phases of sepsis. We studied the effect of SIRT-2 inhibition during the hypo-inflammatory phase on immune function and 7-day survival. We used a RAW264.7 (RAW) cell model of sepsis for mechanistic studies. We confirmed key findings in diet induced obese (DIO) mice with sepsis. Results We observed that the ob/ob-septic mice showed an enhanced early inflammation and a persistent and prolonged hypo-inflammatory phase when compared to WT mice. Unlike WT mice that showed increased SIRT1 expression, we found that SIRT2 levels were increased in ob/ob mice during hypo-inflammation. SIRT-2 inhibition in ob/ob mice during the hypo-inflammatory phase of sepsis reversed the repressed microvascular inflammation in vivo via activation of endothelial cells and circulating leukocytes and significantly improved survival. We confirmed the key finding of the role of SIRT2 during hypo-inflammatory phase of sepsis in this project in DIO-sepsis mice. Mechanistically, in the sepsis cell model, SIRT-2 expression modulated inflammatory response by deacetylation of NFκBp65. Conclusion SIRT-2 regulates microvascular inflammation in obese mice with sepsis and may

iNOS inhibits hair regeneration in obese diabetic (ob/ob) mice.

PubMed

Sasaki, Mari; Shinozaki, Shohei; Morinaga, Hironobu; Kaneki, Masao; Nishimura, Emi; Shimokado, Kentaro

2018-07-02

Previous studies have shown that androgenic alopecia is associated with metabolic syndrome and diabetes. However, the detailed mechanism whereby diabetes causes alopecia still remains unclear. We focused on the inflammatory response that is caused by diabetes or obesity, given that inflammation is a risk factor for hair loss. Inducible nitric oxide synthase (iNOS) is known to be upregulated under conditions of acute or chronic inflammation. To clarify the potential role of iNOS in diabetes-related alopecia, we generated obese diabetic iNOS-deficient (ob/ob; iNOS-KO mice). We observed that ob/ob; iNOS-KO mice were potentiated for the transition from telogen (rest phase) to anagen (growth phase) in the hair cycle compared with iNOS-proficient ob/ob mice. To determine the effect of nitric oxide (NO) on the hair cycle, we administered an iNOS inhibitor intraperitoneally (compound 1400 W, 10 mg/kg) or topically (10% aminoguanidine) in ob/ob mice. We observed that iNOS inhibitors promoted anagen transition in ob/ob mice. Next, we administered an NO donor (S-nitrosoglutathione, GSNO), to test whether NO has the telogen elongation effects. The NO donor was sufficient to induce telogen elongation in wild-type mice. Together, our data indicate that iNOS-derived NO plays a role in telogen elongation under the inflammatory conditions associated with diabetes in mice. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Energy balance in adrenalectomized ob/ob mice: effects of dietary starch and glucose.

PubMed

Warwick, B P; Romsos, D R

1988-07-01

Effects of different carbohydrate types on energy balance, fatty acid synthesis, and plasma insulin concentrations in adrenalectomized ob/ob mice were investigated. Obese (ob/ob) and lean mice adrenalectomized at 4 wk of age received one of four high-carbohydrate powdered diets for 3 wk: stock, glucose, starch, or starch plus wheat bran. Adrenalectomy reduced energy intake of ob/ob mice equally independent of diet type, whereas energetic efficiency, in vivo rates of fatty acid synthesis in liver and white adipose tissue, and plasma insulin concentrations were substantially reduced to approach values in lean mice in all adrenalectomized ob/ob mice except those fed glucose. The ability of adrenalectomy to normalize energy balance in ob/ob mice depends on factors other than the reduced circulating concentration of glucocorticoids alone. Diet composition is a crucial factor, and striking differences exist between semipurified diets containing a simple sugar (glucose) and those containing a complex carbohydrate (starch), with no additional effect of dietary fiber (wheat bran).

Role of estrogen receptor signaling in skeletal response to leptin in female ob/ob mice.

PubMed

Turner, Russell T; Philbrick, Kenneth A; Kuah, Amida F; Branscum, Adam J; Iwaniec, Urszula T

2017-06-01

Leptin, critical in regulation of energy metabolism, is also important for normal bone growth, maturation and turnover. Compared to wild type (WT) mice, bone mass is lower in leptin-deficient ob/ob mice. Osteopenia in growing ob/ob mice is due to decreased bone accrual, and is associated with reduced longitudinal bone growth, impaired cancellous bone maturation and increased marrow adipose tissue (MAT). However, leptin deficiency also results in gonadal dysfunction, disrupting production of gonadal hormones which regulate bone growth and turnover. The present study evaluated the role of increased estrogen in mediating the effects of leptin on bone in ob/ob mice. Three-month-old female ob/ob mice were randomized into one of the 3 groups: (1) ob/ob  + vehicle (veh), (2) ob/ob  + leptin (leptin) or (3) ob/ob  + leptin and the potent estrogen receptor antagonist ICI 182,780 (leptin + ICI). Age-matched WT mice received vehicle. Leptin (40 µg/mouse, daily) and ICI (10 µg/mouse, 2×/week) were administered by subcutaneous injection for 1 month and bone analyzed by X-ray absorptiometry, microcomputed tomography and static and dynamic histomorphometry. Uterine weight did not differ between ob/ob mice and ob/ob mice receiving leptin + ICI, indicating that ICI successfully blocked the uterine response to leptin-induced increases in estrogen levels. Compared to leptin-treated ob/ob mice, ob/ob mice receiving leptin + ICI had lower uterine weight; did not differ in weight loss, MAT or bone formation rate; and had higher longitudinal bone growth rate and cancellous bone volume fraction. We conclude that increased estrogen signaling following leptin treatment is dispensable for the positive actions of leptin on bone and may attenuate leptin-induced bone growth. © 2017 Society for Endocrinology.

Going with the flow: Hydrologic response of middle Lena River (Siberia) to the climate variability and change

NASA Astrophysics Data System (ADS)

Gautier, Emmanuèle; Dépret, Thomas; Costard, François; Virmoux, Clément; Fedorov, Alexander; Grancher, Delphine; Konstantinov, Pavel; Brunstein, Daniel

2018-02-01

Recent observations indicate that over the last decades, climate change has increasingly influenced the frequency, intensity and duration of extreme climatic and hydrologic events. The main aim of this study is to determine the hydrologic response, especially the flood evolution, of the Lena River in Eastern Siberia to ongoing climate change. Draining the coldest region of the Northern Hemisphere, the Lena River is impacted by global warming, which is particularly pronounced in periglacial areas characterized by deep and continuous permafrost. We document the hydrologic variability of the Middle Lena River, first by characterizing trend and stationarity of monthly discharges. Second, we analyze on the basis of the peak over threshold method (POT) the temporal evolution of intensity and duration of three discharge classes: bar-full discharge, bank-full discharge and large floods. Finally, we also determined the dates of the flood beginning and of the flood peak. Data on mean monthly discharge and flood peaks are available since 1936 and daily discharges since 1954. Our results provide evidence for a net hydrologic change with an increase in the intensity and duration of floods in the two decades ending in 2012. The frequency of high floods is unprecedented, and small floods no longer occur. The tail of the temporal distribution of the flood peak is also changing. More frequent early floods are occurring in spring with secondary flood peaks in summer, the latest probably represents the most striking change. Furthermore, the changes have been accelerating since 2004. Finally, two islands were instrumented (2008-2012) in order to study the flooding dynamics with a better precision.

Peripheral nervous system insulin resistance in ob/ob mice

PubMed Central

2013-01-01

Background A reduction in peripheral nervous system (PNS) insulin signaling is a proposed mechanism that may contribute to sensory neuron dysfunction and diabetic neuropathy. Neuronal insulin resistance is associated with several neurological disorders and recent evidence has indicated that dorsal root ganglion (DRG) neurons in primary culture display altered insulin signaling, yet in vivo results are lacking. Here, experiments were performed to test the hypothesis that the PNS of insulin-resistant mice displays altered insulin signal transduction in vivo. For these studies, nondiabetic control and type 2 diabetic ob/ob mice were challenged with an intrathecal injection of insulin or insulin-like growth factor 1 (IGF-1) and downstream signaling was evaluated in the DRG and sciatic nerve using Western blot analysis. Results The results indicate that insulin signaling abnormalities documented in other “insulin sensitive” tissues (i.e. muscle, fat, liver) of ob/ob mice are also present in the PNS. A robust increase in Akt activation was observed with insulin and IGF-1 stimulation in nondiabetic mice in both the sciatic nerve and DRG; however this response was blunted in both tissues from ob/ob mice. The results also suggest that upregulated JNK activation and reduced insulin receptor expression could be contributory mechanisms of PNS insulin resistance within sensory neurons. Conclusions These findings contribute to the growing body of evidence that alterations in insulin signaling occur in the PNS and may be a key factor in the pathogenesis of diabetic neuropathy. PMID:24252636

Siberia, the wandering northern terrane, and its changing geography through the Palaeozoic

NASA Astrophysics Data System (ADS)

Cocks, L. Robin M.; Torsvik, Trond H.

2007-05-01

The old terrane of Siberia occupied a very substantial area in the centre of today's political Siberia and also adjacent areas of Mongolia, eastern Kazakhstan, and northwestern China. Siberia's location within the Early Neoproterozoic Rodinia Superterrane is contentious (since few if any reliable palaeomagnetic data exist between about 1.0 Ga and 540 Ma), but Siberia probably became independent during the breakup of Rodinia soon after 800 Ma and continued to be so until very near the end of the Palaeozoic, when it became an integral part of the Pangea Supercontinent. The boundaries of the cratonic core of the Siberian Terrane (including the Patom area) are briefly described, together with summaries of some of the geologically complex surrounding areas, and it is concluded that all of the Palaeozoic underlying the West Siberian Basin (including the Ob-Saisan Surgut area), Tomsk Terrane, Altai-Sayan Terranes (including Salair, Kuznetsk Alatau, Batenov, Kobdin and West Sayan), Ertix Terrane, Barguzin Terrane, Tuva-Mongol Terrane, Central Mongolia Terrane Assemblage, Gobi Altai and Mandalovoo Terranes, Okhotsk Terrane and much of the Verkhoyansk-Kolyma region all formed parts of peri-Siberia, and thus rotated with the main Siberian Craton as those areas were progressively accreted to the main Siberian Terrane at various times during the latest Neoproterozoic and Palaeozoic. The Ertix Terrane is a new term combining what has been termed the "Altay Terrane" or "NE Xinjiang" area of China, and the Baytag, Baaran and Bidz terranes of Mongolia. The Silurian Tuvaella brachiopod fauna is restricted only to today's southern parts of peri-Siberia. Thus, allowing for subsequent rotation, the fauna occurs only in the N of the Siberian Terrane, and, as well as being a helpful indicator of what marginal terranes made up peri-Siberia, is distinctive as being the only Silurian fauna known from northern higher latitudes globally. In contrast, the other terranes adjacent to peri-Siberia

Hydrogen sulfide improves diabetic wound healing in ob/ob mice via attenuating inflammation.

PubMed

Zhao, Huichen; Lu, Shengxia; Chai, Jiachao; Zhang, Yuchao; Ma, Xiaoli; Chen, Jicui; Guan, Qingbo; Wan, Meiyan; Liu, Yuantao

2017-09-01

The proposed mechanisms of impaired wound healing in diabetes involve sustained inflammation, excess oxidative stress and compromised agiogenesis. Hydrogen sulfide (H 2 S) has been reported to have multiple biological activities. We aim to investigate the role of H 2 S in impaired wound healing in ob/ob mice and explore the possible mechanisms involved. Full-thickness skin dorsal wounds were created on ob/ob mice and C57BL/6 mice. Cystathionine-γ-lyase (CSE) expression and H 2 S production were determined in granulation tissues of the wounds. Effects of NaHS on wound healing were evaluated. Inflammation and angiogenesis in granulation tissues of the wounds were examined. CSE expression, and H 2 S content were significantly reduced in granulation tissues of wounds in ob/ob mice compared with control mice. NaHS treatment significantly improved wound healing in ob/ob mice, which was associated with reduced neutrophil and macrophage infiltration, decreased production of tumor necrosis factor (TNF)-α, interleukin (IL)-6. NaHS treatment decreased metalloproteinase (MMP)-9, whereas increased collagen deposition and vascular-like structures in granulation tissues of wounds in ob/ob mice. CSE down-regulation may play a role in the pathogenesis of diabetic impaired wound healing. Exogenous H 2 S could be a potential agent to improve diabetic impaired wound healing by attenuating inflammation and increasing angiogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Chromium (D-phenylalanine)3 improves obesity-induced cardiac contractile defect in ob/ob mice.

PubMed

Dong, Feng; Yang, Xiaoping; Sreejayan, Nair; Ren, Jun

2007-11-01

Low-molecular weight chromium compounds, such as chromium picolinate [Cr(pic)(3)], improve insulin sensitivity, although toxicity is a concern. We synthesized a novel chromium complex, chromium (d-phenylalanine)(3) [Cr(d-phe)(3)], in an attempt to improve insulin sensitivity with reduced toxicity. The aim of this study was to compare the two chromium compounds on cardiac contractile function in ob/ob obese mice. C57BL lean and ob/ob obese mice were randomly divided into three groups: H(2)O, Cr(d-phe)(3), or Cr(pic)(3) (45 mug/kg per day orally for 6 months). The glucose tolerance test displayed improved glucose clearance by Cr(d-phe)(3) but not Cr(pic)(3). Myocytes from ob/ob mice exhibited depressed peak shortening (PS) and maximal velocity of shortening/relengthening (+/-dL/dt), prolonged time-to-PS and time-to-90% relengthening (TR90), reduced electrically stimulated rise in intracellular Ca(2+) (Deltafura-2 fluorescence intensity), and slowed intracellular Ca(2+) decay. Although a 3-month Cr(d-phe)(3) treatment for a separate group of ob/ob and lean 2-month-old mice only rectified reduced +/-dL/dt in ob/ob mice, all mechanical and intracellular Ca(2+) abnormalities were significantly attenuated or ablated by 6 months of Cr(d-phe)(3) but not Cr(pic)(3) treatment (except TR90). Sarco(endo)plasmic reticulum Ca(2+) ATPase activity and Na(+)-Ca(2+) exchanger expression were depressed in ob/ob mice, which were reversed by both Cr(d-phe)(3) and Cr(pic)(3), with a more pronounced effect from Cr(d-phe)(3). Cr(d-phe)(3) corrected reduced insulin-stimulated glucose uptake and improved basal phosphorylation of Akt and insulin receptor, as well as insulin-stimulated phosphorylation of Akt and insulin receptor in ob/ob myocytes. Heart homogenates from ob/ob mice had enhanced oxidative stress and protein carbonyl formation compared with the lean group, which were attenuated by both Cr(d-phe)(3) and Cr(pic)(3). Our data suggest that the new Cr(d-phe)(3) compound possesses

Impaired steroidogenesis in the testis of leptin-deficient mice (ob/ob -/-).

PubMed

Martins, Fabiane Ferreira; Aguila, Marcia Barbosa; Mandarim-de-Lacerda, Carlos Alberto

2017-06-01

The obesity and its comorbidities, including resistance to leptin, impacts the reproductive function. Testes express leptin receptors in the germ cells and Leydig cells. Then, leptin-deficient animals are obese and infertile. We aimed to evaluate the structure and steroidogenic pathway of the testis of deficient leptin mice. Three months old male C57BL/6 mice (wild-type, WT) and deficient leptin (ob/ob) mice had their testes dissected and prepared for analyses. Compared to the WT group, the ob/ob group showed a greater body mass with smaller testes, and alterations in the germinative epithelium: fewer spermatogonia, spermatocytes, and spermatids. The Sertoli cells and the germ cells showed condensed nuclei and nuclear fragmentation indicating cell death, in agreement with a low expression of the proliferating cell nuclear antigen and a high expression of Caspase3. In the ob/ob group, the sperm was absent in the seminiferous tubules, and the steroidogenic pathway was compromised (low 3Beta hydroxysteroid dehydrogenase and steroidogenic acute regulatory protein). Further, all hormone receptors involved in the testicular function were down expressed (androgen, estrogen, follicle-stimulating, luteinizing, aromatase, and nicotinamide adenine dinucleotide phosphate). In conclusion, the findings indicate significant morphological, hormonal and enzymatic changes in the testis of the ob/ob mice. The shifts in the enzymatic steroidogenic pathway and the enzymes related to spermatic activity support the insights about the failures in the fertility of these animals. The study provides new evidence and contributes to the understanding of how the lack of leptin and obesity might negatively modulate the testicular function leading to infertility. Copyright © 2017 Elsevier GmbH. All rights reserved.

Morphological and biochemical alterations of skeletal muscles from the genetically obese (ob/ob) mouse.

PubMed

Kemp, J G; Blazev, R; Stephenson, D G; Stephenson, G M M

2009-08-01

Knowledge of the morphological and biochemical alterations occurring in skeletal muscles of obese animals is relatively limited, particularly with respect to non-limb muscles and relationship to fibre type. Sternomastoid (SM; fast-twitch), extensor digitorum longus (EDL; fast-twitch), and soleus (SOL; mixed) muscles of ob/ob mouse (18-22 weeks) were examined with respect to size (mass, muscle mass-to-body mass ratio, cross-sectional area (CSA)), fibre CSA, protein content, myosin heavy chain (MHC) content, MHC isoform (MHC(i)) composition, MHC(i)-based fibre type composition, and lactate dehydrogenase isoenzyme (LDH(iso)) composition. Compared with (control) muscles from lean mice, all the three muscles from ob/ob mice were smaller in size (by 13-30%), with SM and EDL being the most affected. The CSA of IIB and IIB+IID fibres (the predominant fibre types in SM and EDL muscles) was markedly smaller (by approximately 30%) in ob/ob mice, consistent with differences in muscle size. Total protein content (normalised to muscle mass) was significantly lower in EDL (-9.7%) and SOL (-14.1%) muscles of ob/ob mice, but there were no differences between SM, EDL, and SOL muscles from the two animal groups with respect to MHC content (also normalised to muscle mass). Electrophoretic analyses of MHC(i) composition in whole muscle homogenates and single muscle fibres showed a shift towards slower MHC(i) content, slower MHC(i) containing fibres, and a greater proportion of hybrid fibres in all the three muscles of ob/ob mice, with a shift towards a more aerobic-oxidative phenotype also observed with respect to LDH(iso) composition. This study showed that SM, EDL, and SOL muscles of ob/ob mice display size reductions to an extent that seems to be largely related to fibre type composition, and a shift in fibre type composition that may result from a process of structural remodelling, as suggested by the increased proportion of hybrid fibres in muscles of ob/ob mice.

Thermal processes of thermokarst lakes in the continuous permafrost zone of northern Siberia - observations and modeling (Lena River Delta, Siberia)

NASA Astrophysics Data System (ADS)

Boike, J.; Georgi, C.; Kirilin, G.; Muster, S.; Abramova, K.; Fedorova, I.; Chetverova, A.; Grigoriev, M.; Bornemann, N.; Langer, M.

2015-10-01

Thermokarst lakes are typical features of the northern permafrost ecosystems, and play an important role in the thermal exchange between atmosphere and subsurface. The objective of this study is to describe the main thermal processes of the lakes and to quantify the heat exchange with the underlying sediments. The thermal regimes of five lakes located within the continuous permafrost zone of northern Siberia (Lena River Delta) were investigated using hourly water temperature and water level records covering a 3-year period (2009-2012), together with bathymetric survey data. The lakes included thermokarst lakes located on Holocene river terraces that may be connected to Lena River water during spring flooding, and a thermokarst lake located on deposits of the Pleistocene Ice Complex. Lakes were covered by ice up to 2 m thick that persisted for more than 7 months of the year, from October until about mid-June. Lake-bottom temperatures increased at the start of the ice-covered period due to upward-directed heat flux from the underlying thawed sediment. Prior to ice break-up, solar radiation effectively warmed the water beneath the ice cover and induced convective mixing. Ice break-up started at the beginning of June and lasted until the middle or end of June. Mixing occurred within the entire water column from the start of ice break-up and continued during the ice-free periods, as confirmed by the Wedderburn numbers, a quantitative measure of the balance between wind mixing and stratification that is important for describing the biogeochemical cycles of lakes. The lake thermal regime was modeled numerically using the FLake model. The model demonstrated good agreement with observations with regard to the mean lake temperature, with a good reproduction of the summer stratification during the ice-free period, but poor agreement during the ice-covered period. Modeled sensitivity to lake depth demonstrated that lakes in this climatic zone with mean depths > 5 m develop

Hormone-sensitive lipase deficiency suppresses insulin secretion from pancreatic islets of Lep{sup ob/ob} mice

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

Sekiya, Motohiro; Yahagi, Naoya, E-mail: nyahagi-tky@umin.ac.jp; Laboratory of Molecular Physiology on Energy Metabolism, Graduate School of Medicine, University of Tokyo, Tokyo 113-8655

2009-09-25

It has long been a matter of debate whether the hormone-sensitive lipase (HSL)-mediated lipolysis in pancreatic {beta}-cells can affect insulin secretion through the alteration of lipotoxicity. We generated mice lacking both leptin and HSL (Lep{sup ob/ob}/HSL{sup -/-}) and explored the role of HSL in pancreatic {beta}-cells in the setting of obesity. Lep{sup ob/ob}/HSL{sup -/-} developed elevated blood glucose levels and reduced plasma insulin levels compared with Lep{sup ob/ob}/HSL{sup +/+} in a fed state, while the deficiency of HSL did not affect glucose homeostasis in Lep{sup +/+} background. The deficiency of HSL exacerbated the accumulation of triglycerides in Lep{sup ob/ob} islets,more » leading to reduced glucose-stimulated insulin secretion. The deficiency of HSL also diminished the islet mass in Lep{sup ob/ob} mice due to decreased cell proliferation. In conclusion, HSL affects insulin secretary capacity especially in the setting of obesity.« less

Natural and environmental vulnerability analysis through remote sensing and GIS techniques: a case study of Indigirka River basin, Eastern Siberia, Russia

NASA Astrophysics Data System (ADS)

Boori, Mukesh S.; Choudhary, Komal; Kupriyanov, Alexander; Sugimoto, Atsuko; Evers, Mariele

2016-10-01

The aim of this research work is to understand natural and environmental vulnerability situation and its cause such as intensity, distribution and socio-economic effect in the Indigirka River basin, Eastern Siberia, Russia. This paper identifies, assess and classify natural and environmental vulnerability using landscape pattern from multidisciplinary approach, based on remote sensing and Geographical Information System (GIS) techniques. A model was developed by following thematic layers: land use/cover, vegetation, wetland, geology, geomorphology and soil in ArcGIS 10.2 software. According to numerical results vulnerability classified into five levels: low, sensible, moderate, high and extreme vulnerability by mean of cluster principal. Results are shows that in natural vulnerability maximum area covered by moderate (29.84%) and sensible (38.61%) vulnerability and environmental vulnerability concentrated by moderate (49.30%) vulnerability. So study area has at medial level vulnerability. The results found that the methodology applied was effective enough in the understanding of the current conservation circumstances of the river basin in relation to their environment with the help of remote sensing and GIS. This study is helpful for decision making for eco-environmental recovering and rebuilding as well as predicting the future development.

Advective transport observations with MODPATH-OBS--documentation of the MODPATH observation process

USGS Publications Warehouse

Hanson, R.T.; Kauffman, L.K.; Hill, M.C.; Dickinson, J.E.; Mehl, S.W.

2013-01-01

. Though the program name MODPATH-OBS specifically refers to observations, the program also can be used to calculate model prediction of observations. MODPATH-OBS is primarily intended for use with separate programs that conduct sensitivity analysis, data needs assessment, parameter estimation, and uncertainty analysis, such as UCODE_2005, and PEST. In many circumstances, refined grids in selected parts of a model are important to simulated hydraulics, detailed inflows and outflows, or other system characteristics. MODFLOW-LGR and MODPATH-LGR support accurate local grid refinement in which both mass (flows) and energy (head) are conserved across the local grid boundary. MODPATH-OBS is designed to take advantage of these capabilities. For example, particles tracked between a pumping well and a nearby stream, which are simulated poorly if a river and well are located in a single large grid cell, can be simulated with improved accuracy using a locally refined grid in MODFLOW-LGR, MODPATH-LGR, and MODPATH-OBS. The locally-refined-grid approach can provide more accurate simulated equivalents to observed transport between the well and the river. The documentation presented here includes a brief discussion of previous work, description of the methods, and detailed descriptions of the required input files and how the output files are typically used.

Linkage between seasonal hydrology and carbon flux dynamics in tundra ponds: Samoylov Island, Lena River Delta, Siberia

NASA Astrophysics Data System (ADS)

Abnizova, Anna; Bornemann, Niko; Boike, Julia

2010-05-01

Arctic ponds have been recently recognized as being highly sensitive to changing climate. To date, ponds and lakes are disappearing in Alaska, Siberia and Canadian High Arctic because of climate warming (Fitzgerald et al. 2003; Smith et al. 2005; and Smol et al. 2007). While numerous limnological studies have been done on arctic ponds located in the Canadian High Arctic (Douglas and Smol, 1994; Hamilton et al. 2001; Lim et al., 2001), there is a limited number of studies on tundra ponds located in other circumpolar environments (e.g. Northern Siberia). Duff et al. (1999) describes tundra lakes in northern Russia as clear, dilute, oligotrophic lakes with low nutrients and dissolved organic carbon concentration. While numerous ponds and lakes exists in the Lena River Delta averaging to 2120 lakes of all sizes for every 1000 km2, no studies have been done to understand carbon flux dynamics of these freshwater ecosystems. In this study hydrological monitoring based on water balance framework was applied to a series of ponds and lakes located on Samoylov Island, 120 km south of the Arctic Ocean in the southern central Lena River Delta (72° 22' N, 126 ° 30' E) from July to September 2008. To better understand spatial differences in pond hydrology and carbon flux dynamics, the physical and biochemical data was collected from 42 tundra ponds. The selection of the ponds was based on their size (small, medium, large) and depth values ranging from 10 to 120 cm. The estimation of the seasonal water budget in 2008 showed that losses through evapotranspiration were offset by similar precipitation inputs and resulted in the equilibrium storage values in the study ponds prior to the freeze-back. Preliminary analysis showed that more than 50% of the ponds had DOC > 6.5 mg/l which exceeds average value of other Arctic ponds reported in literature (Duff et al. 1999 and Hamilton et al. 2001). Elevated DOC concentrations (> 8 mg/l) were found in the small and medium ponds with depth

Flooding of the Taz, Pur, and Yenisey Rivers, Russia

NASA Technical Reports Server (NTRS)

2002-01-01

Each spring and summer, rivers across Siberia experience flooding as the waters in the south begin to melt and run before the ice has retreated from the northern limits. The ice causes jams which are sometimes loosened up using explosives. This pair of MODIS images from June 18, 2002, shows flooding on the Pur (left), Taz (center), and Yenisey (right) Rivers in central Siberia. In the false-color image, ice and snow are red, clouds are white, water is black, and vegetation is green. Bare soil is brown. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

Ob/ob Mouse Livers Show Decreased Oxidative Phosphorylation Efficiencies and Anaerobic Capacities after Cold Ischemia

PubMed Central

Tagaloa, Sherry; Zhang, Linda; Dare, Anna J.; MacDonald, Julia R.; Yeong, Mee-Ling; Bartlett, Adam S. J. R.; Phillips, Anthony R. J.

2014-01-01

Background Hepatic steatosis is a major risk factor for graft failure in liver transplantation. Hepatic steatosis shows a greater negative influence on graft function following prolonged cold ischaemia. As the impact of steatosis on hepatocyte metabolism during extended cold ischaemia is not well-described, we compared markers of metabolic capacity and mitochondrial function in steatotic and lean livers following clinically relevant durations of cold preservation. Methods Livers from 10-week old leptin-deficient obese (ob/ob, n = 9) and lean C57 mice (n = 9) were preserved in ice-cold University of Wisconsin solution. Liver mitochondrial function was then assessed using high resolution respirometry after 1.5, 3, 5, 8, 12, 16 and 24 hours of storage. Metabolic marker enzymes for anaerobiosis and mitochondrial mass were also measured in conjunction with non-bicarbonate tissue pH buffering capacity. Results Ob/ob and lean mice livers showed severe (>60%) macrovesicular and mild (<30%) microvesicular steatosis on Oil Red O staining, respectively. Ob/ob livers had lower baseline enzymatic complex I activity but similar adenosine triphosphate (ATP) levels compared to lean livers. During cold storage, the respiratory control ratio and complex I-fueled phosphorylation deteriorated approximately twice as fast in ob/ob livers compared to lean livers. Ob/ob livers also demonstrated decreased ATP production capacities at all time-points analyzed compared to lean livers. Ob/ob liver baseline lactate dehydrogenase activities and intrinsic non-bicarbonate buffering capacities were depressed by 60% and 40%, respectively compared to lean livers. Conclusions Steatotic livers have impaired baseline aerobic and anaerobic capacities compared to lean livers, and mitochondrial function indices decrease particularly from after 5 hours of cold preservation. These data provide a mechanistic basis for the clinical recommendation of shorter cold storage durations in steatotic donor

Thermogenesis, fatty acid synthesis with oxidation, and inflammation in the brown adipose tissue of ob/ob (-/-) mice.

PubMed

Martins, Fabiane Ferreira; Bargut, Thereza Cristina Lonzetti; Aguila, Marcia Barbosa; Mandarim-de-Lacerda, Carlos Alberto

2017-03-01

Brown adipose tissue (BAT) is specialized in heat production, but its metabolism in ob/ob mice is still a matter of debate. We aimed to verify ob/ob mice BAT using C57Bl/6 male mice (as the wild-type, WT) and leptin-deficient ob/ob mice (on the C57Bl/6 background strain), at three months of age (n=10/group). At euthanasia, animals had their interscapular BAT weighed, and prepared for analysis (Western blot, and RT-qPCR). In comparison with the WT group, the ob/ob group showed reduced thermogenic signaling markers (gene expression of beta 3-adrenergic receptor, beta3-AR; PPARgamma coactivator 1 alpha, PGC1alpha, and uncoupling protein 1, UCP1). The ob/ob group also showed impaired gene expression for lipid utilization (perilipin was increased, while other markers were diminished: carnitine palmitoyltransferase-1b, CPT-1b; cluster of differentiation 36, CD36; fatty acid binding protein 4, FABP4; fatty acid synthase, FAS, and sterol regulatory element-binding protein 1c, SREBP1c), and altered protein expression of insulin signaling (diminished pAKT, TC10, and GLUT-4). Lastly, the ob/ob group showed increased gene expression of markers of inflammation (interleukin 1 beta, IL-1beta; IL-6, tumor necrosis factor alpha, TNFalpha; and monocyte chemotactic protein-1, MCP-1). In conclusion, the ob/ob mice have decreased thermogenic markers associated with reduced gene expression related to fatty acid synthesis, mobilization, and oxidation. There were also alterations in insulin signaling and protein and gene expressions of inflammation. The findings suggest that the lack of substrate for thermogenesis and the local inflammation negatively regulated thermogenic signaling in the ob/ob mice. Copyright © 2016 Elsevier GmbH. All rights reserved.

Soil temperature of peatland landscapes as a factor in the development of exogenous processes of biogenic relief formation in engineering development of territory

NASA Astrophysics Data System (ADS)

Korkin, S.; Talyneva, O.; Kail, E.

2018-03-01

In the presented work we consider mire landscapes in the context of temperature monitoring. The mire landscapes in engineering development of the territory are very sensitive to anthropogenic impact that leads to a change in surface conditions, changes in natural succession and, as a rule, to changes in soil temperature and properties, which in turn may develop a complex of hostile geodynamic processes. For this study we used recording systems for field measurement of peat and subsoil temperatures. The measurements were made in two key areas: the territory of the north-taiga landscapes of Western Siberia (the Siberian Ridges), and the territory of the middle-taiga landscapes of Western Siberia (the Ob middle-river lowland). The paper analyses the data obtained from five observation sites (3, 5, 5a, 6 and 8) referred to hydromorphic landscapes. For the territory of the Siberian Ridges the 5-year average soil temperature was 3°C. For the Ob middle-river lowland the 6-year average soil temperature was 4.2°C. The annual soil temperature in the period 2015-2016 for Site 5a (man-disturbed area) was 8.3°C at all depths, which is 3.8°C higher than in a natural bog (Site 5 was a control area).

Ongoing climatic extreme dynamics in Siberia

NASA Astrophysics Data System (ADS)

Gordov, E. P.; Shulgina, T. M.; Okladnikov, I. G.; Titov, A. G.

2013-12-01

Ongoing global climate changes accompanied by the restructuring of global processes in the atmosphere and biosphere are strongly pronounced in the Northern Eurasia regions, especially in Siberia. Recent investigations indicate not only large changes in averaged climatic characteristics (Kabanov and Lykosov, 2006, IPCC, 2007; Groisman and Gutman, 2012), but more frequent occurrence and stronger impacts of climatic extremes are reported as well (Bulygina et al., 2007; IPCC, 2012: Climate Extremes, 2012; Oldenborh et al., 2013). This paper provides the results of daily temperature and precipitation extreme dynamics in Siberia for the last three decades (1979 - 2012). Their seasonal dynamics is assessed using 10th and 90th percentile-based threshold indices that characterize frequency, intensity and duration of climatic extremes. To obtain the geographical pattern of these variations with high spatial resolution, the sub-daily temperature data from ECMWF ERA-Interim reanalysis and daily precipitation amounts from APHRODITE JMA dataset were used. All extreme indices and linear trend coefficients have been calculated using web-GIS information-computational platform Climate (http://climate.scert.ru/) developed to support collaborative multidisciplinary investigations of regional climatic changes and their impacts (Gordov et al., 2012). Obtained results show that seasonal dynamics of daily temperature extremes is asymmetric for tails of cold and warm temperature extreme distributions. Namely, the intensity of warming during cold nights is higher than during warm nights, especially at high latitudes of Siberia. The similar dynamics is observed for cold and warm day-time temperatures. Slight summer cooling was observed in the central part of Siberia. It is associated with decrease in warm temperature extremes. In the southern Siberia in winter, we also observe some cooling mostly due to strengthening of the cold temperature extremes. Changes in daily precipitation extremes

Leptin Increases Striatal Dopamine D2 Receptor Binding in Leptin-Deficient Obese (ob/ob) Mice

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

Pfaffly, J.; Michaelides, M.; Wang, G-J.

2010-06-01

Peripheral and central leptin administration have been shown to mediate central dopamine (DA) signaling. Leptin-receptor deficient rodents show decreased DA D2 receptor (D2R) binding in striatum and unique DA profiles compared to controls. Leptin-deficient mice show increased DA activity in reward-related brain regions. The objective of this study was to examine whether basal D2R-binding differences contribute to the phenotypic behaviors of leptin-deficient ob/ob mice, and whether D2R binding is altered in response to peripheral leptin treatment in these mice. Leptin decreased body weight, food intake, and plasma insulin concentration in ob/ob mice but not in wild-type mice. Basal striatal D2Rmore » binding (measured with autoradiography [{sup 3}H] spiperone) did not differ between ob/ob and wild-type mice but the response to leptin did. In wild-type mice, leptin decreased striatal D2R binding, whereas, in ob/ob mice, leptin increased D2R binding. Our findings provide further evidence that leptin modulates D2R expression in striatum and that these effects are genotype/phenotype dependent.« less

Odor-Induced Neuronal Rhythms in the Olfactory Bulb Are Profoundly Modified in ob/ob Obese Mice

PubMed Central

Chelminski, Yan; Magnan, Christophe; Luquet, Serge H.; Everard, Amandine; Meunier, Nicolas; Gurden, Hirac; Martin, Claire

2017-01-01

Leptin, the product of the Ob(Lep) gene, is a peptide hormone that plays a major role in maintaining the balance between food intake and energy expenditure. In the brain, leptin receptors are expressed by hypothalamic cells but also in the olfactory bulb, the first central structure coding for odors, suggesting a precise function of this hormone in odor-evoked activities. Although olfaction plays a key role in feeding behavior, the ability of the olfactory bulb to integrate the energy-related signal leptin is still missing. Therefore, we studied the fate of odor-induced activity in the olfactory bulb in the genetic context of leptin deficiency using the obese ob/ob mice. By means of an odor discrimination task with concomitant local field potential recordings, we showed that ob/ob mice perform better than wild-type (WT) mice in the early stage of the task. This behavioral gain of function was associated in parallel with profound changes in neuronal oscillations in the olfactory bulb. The distribution of the peaks in the gamma frequency range was shifted toward higher frequencies in ob/ob mice compared to WT mice before learning. More notably, beta oscillatory activity, which has been shown previously to be correlated with olfactory discrimination learning, was longer and stronger in expert ob/ob mice after learning. Since oscillations in the olfactory bulb emerge from mitral to granule cell interactions, our results suggest that cellular dynamics in the olfactory bulb are deeply modified in ob/ob mice in the context of olfactory learning. PMID:28154537

Transient modeling of the ground thermal conditions using satellite data in the Lena River delta, Siberia

NASA Astrophysics Data System (ADS)

Westermann, Sebastian; Peter, Maria; Langer, Moritz; Schwamborn, Georg; Schirrmeister, Lutz; Etzelmüller, Bernd; Boike, Julia

2017-06-01

Permafrost is a sensitive element of the cryosphere, but operational monitoring of the ground thermal conditions on large spatial scales is still lacking. Here, we demonstrate a remote-sensing-based scheme that is capable of estimating the transient evolution of ground temperatures and active layer thickness by means of the ground thermal model CryoGrid 2. The scheme is applied to an area of approximately 16 000 km2 in the Lena River delta (LRD) in NE Siberia for a period of 14 years. The forcing data sets at 1 km spatial and weekly temporal resolution are synthesized from satellite products and fields of meteorological variables from the ERA-Interim reanalysis. To assign spatially distributed ground thermal properties, a stratigraphic classification based on geomorphological observations and mapping is constructed, which accounts for the large-scale patterns of sediment types, ground ice and surface properties in the Lena River delta. A comparison of the model forcing to in situ measurements on Samoylov Island in the southern part of the study area yields an acceptable agreement for the purpose of ground thermal modeling, for surface temperature, snow depth, and timing of the onset and termination of the winter snow cover. The model results are compared to observations of ground temperatures and thaw depths at nine sites in the Lena River delta, suggesting that thaw depths are in most cases reproduced to within 0.1 m or less and multi-year averages of ground temperatures within 1-2 °C. Comparison of monthly average temperatures at depths of 2-3 m in five boreholes yielded an RMSE of 1.1 °C and a bias of -0.9 °C for the model results. The highest ground temperatures are calculated for grid cells close to the main river channels in the south as well as areas with sandy sediments and low organic and ice contents in the central delta, where also the largest thaw depths occur. On the other hand, the lowest temperatures are modeled for the eastern part, which is an

Radioisotope contaminations from releases of the Tomsk-Seversk nuclear facility (Siberia, Russia).

PubMed

Gauthier-Lafaye, F; Pourcelot, L; Eikenberg, J; Beer, H; Le Roux, G; Rhikvanov, L P; Stille, P; Renaud, Ph; Mezhibor, A

2008-04-01

Soils have been sampled in the vicinity of the Tomsk-Seversk facility (Siberia, Russia) that allows us to measure radioactive contaminations due to atmospheric and aquatic releases. Indeed soils exhibit large inventories of man-made fission products including 137Cs (ranging from 33,000 to 68,500 Bq m(-2)) and actinides such as plutonium (i.e. 239+240Pu from 420 to 5900 Bq m(-2)) or 241Am (160-1220 Bq m(-2)). Among all sampling sites, the bank of the Romashka channel exhibits the highest radioisotope concentrations. At this site, some short half-life gamma emitters were detected as well indicating recent aquatic discharge in the channel. In comparison, soils that underwent atmospheric depositions like peat and forest soils exhibit lower activities of actinides and 137Cs. Soil activities are too high to be related solely to global fallout and thus the source of plutonium must be discharges from the Siberian Chemical Combine (SCC) plant. This is confirmed by plutonium isotopic ratios measured by ICP-MS; the low 241Pu/239Pu and 240Pu/239Pu atomic ratios with respect to global fallout ratio or civil nuclear fuel are consistent with weapons grade signatures. Up to now, the influence of Tomsk-Seversk plutonium discharges was speculated in the Ob River and its estuary. Isotopic data from the present study show that plutonium measured in SCC probably constitutes a significant source of plutonium in the aquatic environment, together with plutonium from global fallout and other contaminated sites including Tomsk, Mayak (Russia) and Semipalatinsk (Republic of Kazakhstan). It is estimated that the proportion of plutonium from SCC source can reach 45% for 239Pu and 60% for 241Pu in the sediments.

New Data on Vegetation and Climate Reconstruction in the Baikal-Patom Highland (Eastern Siberia) in the Last Glacial Maximum and Early Holocene

NASA Astrophysics Data System (ADS)

Henry, A.; Bezrukova, E. V.; Teten'kin, A. V.; Kuz'min, M. I.

2018-02-01

The first results of anthracological investigation for Eastern Siberia on the carbonaceous remains of woody and shrubby plants at the archaeological sites Kovrizhka III and IV in the lower reaches of the Vitim River are presented. The results of anthracological studies enabled us to obtain new data on changes in vegetation and climate along the lower reaches of the Vitim River. As a result, new data on human habitation in the lower reaches of the Vitim River in the last glacial maximum and early Holocene were obtained.

Radionuclide contamination of sediment deposits in the Ob and Yenisey estuaries and areas of the Kara Sea.

PubMed

Standring, W J F; Stepanets, O; Brown, J E; Dowdall, M; Borisov, A; Nikitin, A

2008-04-01

The Ob and Yenisey rivers are major contributors to total riverine discharge to the Arctic Ocean. Several large nuclear facilities discharge into these rivers, which could affect actual and potential discharges of radionuclides to the Arctic region. This article presents new radionuclide concentration and grain-size data resulting from analyses of several sediment samples collected during research cruises in the Ob and Yenisey estuaries and adjacent areas during 2000 and 2001. Results indicate that discharges from the main nuclear facilities do not constitute a major contribution to the level of radioactive contamination in the marine areas studied, though Co-60 was detected at low concentrations in some sediment horizons. However, the aggregate contamination from different sources is not radioecologically significant in sediments within the study area, maximum Cs-137 levels being approximately 80 Bq kg(-1) dry weight.

Chronic ethanol consumption lessens the gain of body weight, liver triglycerides, and diabetes in obese ob/ob mice.

PubMed

Fromenty, Bernard; Vadrot, Nathalie; Massart, Julie; Turlin, Bruno; Barri-Ova, Nadège; Lettéron, Philippe; Fautrel, Alain; Robin, Marie-Anne

2009-10-01

Clinical studies suggest that moderate alcohol consumption can have beneficial effects, in particular regarding cardiovascular events, insulin resistance, and type 2 diabetes. In this study, lean and obese diabetic ob/ob mice were submitted or not to chronic ethanol intake via the drinking water for 6 months, which was associated with moderate levels of plasma ethanol. Plasma levels of alanine aminotransferase and aspartate aminotransferase were not increased by alcohol intake. Ethanol consumption progressively reduced the gain of body weight in ob/ob mice, but not in lean mice, and this was observed despite higher calorie intake. Increased plasma free fatty acids and glycerol in ethanol-treated ob/ob mice suggested peripheral lipolysis. Glycemia and insulinemia were significantly reduced, whereas adiponectinemia was increased in ethanol-treated ob/ob mice. Liver weight and triglycerides were significantly decreased in ethanol-treated ob/ob mice, and this was associated with less microvesicular steatosis. Hepatic levels of AMP-activated protein kinase and the phosphorylated form of acetyl-CoA carboxylase were higher in ethanol-treated ob/ob mice, suggesting better fatty acid oxidation. However, hepatic mRNA expression of several lipogenic genes was not reduced by ethanol consumption. Finally, mild oxidative stress was noticed in the liver of ethanol-treated mice, regardless of their genotype. Hence, our data are in keeping with clinical studies suggesting that moderate ethanol intake can have beneficial effects on type 2 diabetes and insulin sensitivity, at least in part through increased levels of plasma adiponectin. However, further studies are needed to determine whether long-term drinking of light-to-moderate amounts of ethanol is safe for the liver.

Structural anatomy of telomere OB proteins.

PubMed

Horvath, Martin P

2011-10-01

Telomere DNA-binding proteins protect the ends of chromosomes in eukaryotes. A subset of these proteins are constructed with one or more OB folds and bind with G+T-rich single-stranded DNA found at the extreme termini. The resulting DNA-OB protein complex interacts with other telomere components to coordinate critical telomere functions of DNA protection and DNA synthesis. While the first crystal and NMR structures readily explained protection of telomere ends, the picture of how single-stranded DNA becomes available to serve as primer and template for synthesis of new telomere DNA is only recently coming into focus. New structures of telomere OB fold proteins alongside insights from genetic and biochemical experiments have made significant contributions towards understanding how protein-binding OB proteins collaborate with DNA-binding OB proteins to recruit telomerase and DNA polymerase for telomere homeostasis. This review surveys telomere OB protein structures alongside highly comparable structures derived from replication protein A (RPA) components, with the goal of providing a molecular context for understanding telomere OB protein evolution and mechanism of action in protection and synthesis of telomere DNA.

Trends in the normalized difference vegetation index (NDVI) associated with urban development in arctic and subarctic Western Siberia

NASA Astrophysics Data System (ADS)

Outten, S.; Miles, V.; Ezau, I.

2015-12-01

Changes in normalized difference vegetation index (NDVI) in the high Arctic have been reliably documented, with widespread "greening" (increase in NDVI), specifically along the northern rim of Eurasia and Alaska. Whereas in West Siberia south of 65N, widespread "browning" (decrease in NDVI) has been noted, although the causes remain largely unclear. In this study we report results of statistical analysis of the spatial and temporal changes in NDVI around 28 major urban areas in the arctic and subarctic Western Siberia. Exploration and exploitation of oil and gas reserves has led to rapid industrialization and urban development in the region. This development has significant impact on the environment and particularly in the vegetation cover in and around the urbanized areas. The analysis is based on 15 years (2000-2014) of high-resolution (250 m) Moderate Resolution Imaging Spectroradiometer (MODIS) data acquired for summer months (June through August) over the entire arctic and subarctic Western Siberian region. The analysis shows that the NDVI background trends are generally in agreement with the trends reported in previous coarse-resolution NDVI studies. Our study reveals greening over the arctic (tundra and tundra-forest) part of the region. Simultaneously, the southern (boreal taiga forest) part is browning, with the more densely vegetation areas or areas with highest NDVI, particularly along Ob River showing strong negative trend. The unexpected and interesting finding of the study is statistically robust indication of the accelerated increase of NDVI ("greening") in the older urban areas. Many Siberian cities become greener even against the decrease in the NDVI background. Moreover, interannual variations of urban NDVI are not coherent with the NDVI background variability. We also find that in tundra zones, NDVI values are higher in a 5-10 km buffer zone around the city edge than in rural areas (40 km distance from the city edge), and in taiga in a 5-10 km

Glycerol-3-Phosphate Acyltransferase 1 Deficiency in ob/ob Mice Diminishes Hepatic Steatosis but Does Not Protect Against Insulin Resistance or Obesity

PubMed Central

Wendel, Angela A.; Li, Lei O.; Li, Yue; Cline, Gary W.; Shulman, Gerald I.; Coleman, Rosalind A.

2010-01-01

OBJECTIVE Hepatic steatosis is strongly associated with insulin resistance, but a causal role has not been established. In ob/ob mice, sterol regulatory element binding protein 1 (SREBP1) mediates the induction of steatosis by upregulating target genes, including glycerol-3-phosphate acyltransferase-1 (Gpat1), which catalyzes the first and committed step in the pathway of glycerolipid synthesis. We asked whether ob/ob mice lacking Gpat1 would have reduced hepatic steatosis and improved insulin sensitivity. RESEARCH DESIGN AND METHODS Hepatic lipids, insulin sensitivity, and hepatic insulin signaling were compared in lean (Lep+/?), lean-Gpat1−/−, ob/ob (Lepob/ob), and ob/ob-Gpat1−/− mice. RESULTS Compared with ob/ob mice, the lack of Gpat1 in ob/ob mice reduced hepatic triacylglycerol (TAG) and diacylglycerol (DAG) content 59 and 74%, respectively, but increased acyl-CoA levels. Despite the reduction in hepatic lipids, fasting glucose and insulin concentrations did not improve, and insulin tolerance remained impaired. In both ob/ob and ob/ob-Gpat1−/− mice, insulin resistance was accompanied by elevated hepatic protein kinase C-ε activation and blunted insulin-stimulated Akt activation. CONCLUSIONS These results suggest that decreasing hepatic steatosis alone does not improve insulin resistance, and that factors other than increased hepatic DAG and TAG contribute to hepatic insulin resistance in this genetically obese model. They also show that the SREBP1-mediated induction of hepatic steatosis in ob/ob mice requires Gpat1. PMID:20200319

Adipose Deficiency of Nrf2 in ob/ob Mice Results in Severe Metabolic Syndrome

PubMed Central

Xue, Peng; Hou, Yongyong; Chen, Yanyan; Yang, Bei; Fu, Jingqi; Zheng, Hongzhi; Yarborough, Kathy; Woods, Courtney G.; Liu, Dianxin; Yamamoto, Masayuki; Zhang, Qiang; Andersen, Melvin E.; Pi, Jingbo

2013-01-01

Nuclear factor E2–related factor 2 (Nrf2) is a transcription factor that functions as a master regulator of the cellular adaptive response to oxidative stress. Our previous studies showed that Nrf2 plays a critical role in adipogenesis by regulating expression of CCAAT/enhancer-binding protein β and peroxisome proliferator–activated receptor γ. To determine the role of Nrf2 in the development of obesity and associated metabolic disorders, the incidence of metabolic syndrome was assessed in whole-body or adipocyte-specific Nrf2-knockout mice on a leptin-deficient ob/ob background, a model with an extremely positive energy balance. On the ob/ob background, ablation of Nrf2, globally or specifically in adipocytes, led to reduced white adipose tissue (WAT) mass, but resulted in an even more severe metabolic syndrome with aggravated insulin resistance, hyperglycemia, and hypertriglyceridemia. Compared with wild-type mice, WAT of ob/ob mice expressed substantially higher levels of many genes related to antioxidant response, inflammation, adipogenesis, lipogenesis, glucose uptake, and lipid transport. Absence of Nrf2 in WAT resulted in reduced expression of most of these factors at mRNA or protein levels. Our findings support a novel role for Nrf2 in regulating adipose development and function, by which Nrf2 controls the capacity of WAT expansion and insulin sensitivity and maintains glucose and lipid homeostasis. PMID:23238296

Structural anatomy of telomere OB proteins

PubMed Central

Horvath, Martin P.

2015-01-01

Telomere DNA-binding proteins protect the ends of chromosomes in eukaryotes. A subset of these proteins are constructed with one or more OB folds and bind with G+T-rich single-stranded DNA found at the extreme termini. The resulting DNA-OB protein complex interacts with other telomere components to coordinate critical telomere functions of DNA protection and DNA synthesis. While the first crystal and NMR structures readily explained protection of telomere ends, the picture of how single-stranded DNA becomes available to serve as primer and template for synthesis of new telomere DNA is only recently coming into focus. New structures of telomere OB fold proteins alongside insights from genetic and biochemical experiments have made significant contributions towards understanding how protein-binding OB proteins collaborate with DNA-binding OB proteins to recruit telomerase and DNA polymerase for telomere homeostasis. This review surveys telomere OB protein structures alongside highly comparable structures derived from replication protein A (RPA) components, with the goal of providing a molecular context for understanding telomere OB protein evolution and mechanism of action in protection and synthesis of telomere DNA. PMID:21950380

Kinematics of OB-associations in Gaia epoch

NASA Astrophysics Data System (ADS)

Mel'nik, A. M.; Dambis, A. K.

2017-12-01

We use stellar proper motions from the Tycho-Gaia Astrometric Solution (TGAS) catalogue to study the kinematics of OB-associations. The TGAS proper motions of OB-associations generally agree well with the Hipparcos proper motions. The parameters of the Galactic rotation curve obtained with TGAS and Hipparcos proper motions agree within the errors. The average one-dimensional velocity dispersion inside 18 OB-associations with more than 10 TGAS stars is σv = 3.9 km s-1, which is considerably smaller, by a factor of 0.4, than the velocity dispersions derived from Hipparcos data. The effective contribution from orbital motions of binary OB-stars into the velocity dispersion σv inside OB-associations is σb = 1.2 km s-1. The median virial and stellar masses of OB-associations are equal to 7.1 × 105 and 9.0 × 103 M⊙, respectively. Thus, OB-associations must be unbound objects, provided they do not include a lot of dense gas. The median star-formation efficiency is ε = 2.1 per cent. Nearly one-third of stars of OB-associations must lie outside their tidal radius. We found that the Per OB1 and Car OB1 associations are expanding with the expansion started in a small region of 11-27 pc 7-10 Myr ago. The average expansion velocity is 6.3 km s-1.

The Cygnus OB2 Star Forming Complex

NASA Astrophysics Data System (ADS)

Rybarczyk, Daniel R.; Bania, Thomas

2018-01-01

Almost all astrophysical systems—from planets to stars to supernovae to entire galaxies—are impacted by the process of star formation. The brightest, most massive stars (OB stars) form in hot young clusters called OB associations. Cygnus OB2 is an OB association containing over 160 OB stars, making it one of the largest in the Milky Way Galaxy. At a distance of less than 1.5 kpc, its proximity to the Sun makes it optimal for assessing the process of Galactic star formation and its implications for stellar evolution, Galactic structure, and Galactic chemical evolution. Using existing data sets, we derive comprehensive maps of the distribution of thermal continuum, atomic, and molecular emission from the interstellar gas in Cyg OB2. The thermal continuum emission stems from the plasma ionized by OB stars. The atomic gas is probed by emission from atomic hydrogen, HI, at 21 cm wavelength. The molecular gas is traced by emission from the CO molecule which is a proxy for molecular hydrogen, H2. We combine these atomic and molecular data to derive a map of the total proton column density distribution in Cyg OB2. We also analyze the velocity fields of the OB stars, the atomic and molecular hydrogen gas, and the HII regions' radio recombination emission. As expected, we find HII regions to be spatially coincident with zones of higher cloud density. Surrounding the greatest concentration of OB stars is a cavity in the radio continuum and CO emission. This results from shock waves produced by the combined action of the high HII region pressure and winds from the OB stars. Such a distribution implies that Cyg OB2 is old enough to have evolved to this state.

Reduced adiposity in ob/ob mice following total body irradiation and bone marrow transplantation.

PubMed

Ablamunits, Vitaly; Weisberg, Stuart P; Lemieux, Jacob E; Combs, Terry P; Klebanov, Simon

2007-06-01

The objective of this study was to assess long-term metabolic consequences of total body irradiation (TBI) and bone marrow transplantation. Severe obesity develops due to both hypertrophy and hyperplasia of adipocytes. We hypothesized that TBI would arrest adipose tissue growth and would affect insulin resistance (IR). We exposed 2-month-old female ob/ob mice to 8 Grays of TBI followed by bone marrow transplantation and tested the animals for body weight (BW) gain, body composition, blood glucose, and insulin sensitivity. Two months after TBI, irradiated mice stopped gaining BW, whereas non-treated mice continued to grow. At the age of 9.5 months, body mass of irradiated mice was 60.6 +/- 1.4 grams, which was only 61% of that in non-treated ob/ob controls (99.4 +/- 1.6 grams). Body composition measurements by DXA showed that decreased BW was primarily due to an impaired fat accumulation. This could not result from the production of leptin by bone marrow-derived adipocyte progenitors because inhibition of the obese phenotype was identical in recipients of both B6 and ob/ob bone marrow. Inability of the irradiated mice to accumulate fat was associated with hepatomegaly, lower levels of monocyte chemoattractant protein-1 expression in adipose tissue, and increased IR. Our data argue in favor of the hypothesis that inability of adipose tissue to expand may increase IR. This mouse model may be valuable for studies of late-onset radiation-induced IR in humans.

New massive members of Cygnus OB2

NASA Astrophysics Data System (ADS)

Berlanas, S. R.; Herrero, A.; Comerón, F.; Pasquali, A.; Motta, C. Bertelli; Sota, A.

2018-04-01

Context. The Cygnus complex is one of the most powerful star forming regions at a close distance from the Sun ( 1.4 kpc). Its richest OB association Cygnus OB2 is known to harbor many tens of O-type stars and hundreds of B-type stars, providing a large homogeneous population of OB stars that can be analyzed. Many studies of its massive population have been developed in the last decades, although the total number of OB stars is still incomplete. Aim. Our aim is to increase the sample of O and B members of Cygnus OB2 and its surroundings by spectroscopically classifying 61 candidates as possible OB-type members of Cygnus OB2, using new intermediate resolution spectroscopy. Methods: We have obtained intermediate resolution (R 5000) spectra for all of the OB-type candidates between 2013 and 2017. We thus performed a spectral classification of the sample using HeI-II and metal lines rates, as well as the Marxist Ghost Buster (MGB) software for O-type stars and the IACOB standards catalog for B-type stars. Results: From the whole sample of 61 candidates, we have classified 42 stars as new massive OB-type stars, earlier than B3, in Cygnus OB2 and surroundings, including 11 O-type stars. The other candidates are discarded as they display later spectral types inconsistent with membership in the association. We have also obtained visual extinctions for all the new confirmed massive OB members, placing them in a Hertzsprung-Russell Diagram using calibrations for Teff and luminosity. Finally, we have studied the age and extinction distribution of our sample within the region. Conclusions: We have obtained new blue intermediate-resolution spectra suitable for spectral classification of 61 OB candidates in Cygnus OB2 and surroundings. The confirmation of 42 new OB massive stars (earlier than B3) in the region allows us to increase the young massive population known in the field. We have also confirmed the correlation between age and Galactic longitude previously found in the

Optical properties and bioavailability of dissolved organic matter along a flow-path continuum from soil pore waters to the Kolyma River, Siberia

NASA Astrophysics Data System (ADS)

Frey, K. E.; Sobczak, W. V.; Mann, P. J.; Holmes, R. M.

2015-08-01

The Kolyma River in Northeast Siberia is among the six largest arctic rivers and drains a region underlain by vast deposits of Holocene-aged peat and Pleistocene-aged loess known as yedoma, most of which is currently stored in ice-rich permafrost throughout the region. These peat and yedoma deposits are important sources of dissolved organic matter (DOM) to inland waters that in turn play a significant role in the transport and ultimate remineralization of organic carbon to CO2 and CH4 along the terrestrial flow-path continuum. The turnover and fate of terrigenous DOM during offshore transport will largely depend upon the composition and amount of carbon released to inland and coastal waters. Here, we measured the optical properties of chromophoric DOM (CDOM) from a geographically extensive collection of waters spanning soil pore waters, streams, rivers, and the Kolyma River mainstem throughout a ∼ 250 km transect of the northern Kolyma River basin. During the period of study, CDOM absorbance values were found to be robust proxies for the concentration of DOM, whereas additional CDOM parameters such as spectral slopes (S) were found to be useful indicators of DOM quality along the flow-path. In particular, CDOM absorption at 254 nm showed a strong relationship with dissolved organic carbon (DOC) concentrations across all water types (r2 = 0.958, p < 0.01). The spectral slope ratio (SR) of CDOM demonstrated statistically significant differences between all four water types and tracked changes in the concentration of bioavailable DOC, suggesting that this parameter may be suitable for clearly discriminating shifts in organic matter characteristics among water types along the full flow-path continuum across this landscape. The heterogeneity of environmental characteristics and extensive continuous permafrost of the Kolyma River basin combine to make this a critical region to investigate and monitor. With ongoing and future permafrost degradation, peat and yedoma

New genetic lineage within the Siberian subtype of tick-borne encephalitis virus found in Western Siberia, Russia.

PubMed

Tkachev, Sergey E; Chicherina, Galina S; Golovljova, Irina; Belokopytova, Polina S; Tikunov, Artem Yu; Zadora, Oksana V; Glupov, Victor V; Tikunova, Nina V

2017-12-01

Tick-borne encephalitis virus (TBEV), a member of the Flaviviridae family, is a causative agent of a severe neurological disease. There are three main TBEV subtypes: the European (TBEV-Eu), Far Eastern (TBEV-FE), and Siberian (TBEV-Sib). Currently, three lineages within TBEV-Sib have been recorded. In this study, the genetic and biological characteristics of a new original strain, TBEV-2871, isolated in the Novosibirsk province of Western Siberia, Russia were investigated. The strain has low neuroinvasiveness in mice. Phylogenetic analysis demonstrated that TBEV-2871 belongs to TBEV-Sib, but does not cluster with any of the TBEV-Sib lineages. The TBEV-2871 strain has 88-89% nucleotide sequence identity with the other TBEV-Sib strains, 84-86% nucleotide sequence identity with the TBEV-FE and TBEV-Eu subtypes and is genetically close to the subtype division border. The TBEV-2871 polyprotein sequence includes 43 unique amino acid substitutions, 30 of which are recorded at positions that are conserved among all TBEV subtypes. Strain TBEV-2871 and two similar but not identical isolates found in Kemerovo province, Western Siberia are separated into a new lineage tentatively named Obskaya after the name of Ob riber, in the vicinity of which the TBEV-2871 was first found. A molecular evolution investigation demonstrated that within TBEV-Sib, the Obskaya lineage likely separated 1535years ago, which is even earlier than the Baltic lineage. Copyright © 2017 Elsevier B.V. All rights reserved.

iPLA2β deficiency attenuates obesity and hepatic steatosis in ob/ob mice through hepatic fatty-acyl phospholipid remodeling.

PubMed

Deng, Xiuling; Wang, Jiliang; Jiao, Li; Utaipan, Tanyarath; Tuma-Kellner, Sabine; Schmitz, Gerd; Liebisch, Gerhard; Stremmel, Wolfgang; Chamulitrat, Walee

2016-05-01

PLA2G6 or GVIA calcium-independent PLA2 (iPLA2β) is identified as one of the NAFLD modifier genes in humans, and thought to be a target for NAFLD therapy. iPLA2β is known to play a house-keeping role in phospholipid metabolism and remodeling. However, its role in NAFLD pathogenesis has not been supported by results obtained from high-fat feeding of iPLA2β-null (PKO) mice. Unlike livers of human NAFLD and genetically obese rodents, fatty liver induced by high-fat diet is not associated with depletion of hepatic phospholipids. We therefore tested whether iPLA2β could regulate obesity and hepatic steatosis in leptin-deficient mice by cross-breeding PKO with ob/ob mice to generate ob/ob-PKO mice. Here we observed an improvement in ob/ob-PKO mice with significant reduction in serum enzymes, lipids, glucose, insulin as well as improved glucose tolerance, and reduction in islet hyperplasia. The improvement in hepatic steatosis measured by liver triglycerides, fatty acids and cholesterol esters was associated with decreased expression of PPARγ and de novo lipogenesis genes, and the reversal of β-oxidation gene expression. Notably, ob/ob livers contained depleted levels of lysophospholipids and phospholipids, and iPLA2β deficiency in ob/ob-PKO livers lowers the former, but replenished the latter particularly phosphatidylethanolamine (PE) and phosphatidylcholine (PC) that contained arachidonic (AA) and docosahexaenoic (DHA) acids. Compared with WT livers, PKO livers also contained increased PE and PC containing AA and DHA. Thus, iPLA2β deficiency protected against obesity and ob/ob fatty liver which was associated with hepatic fatty-acyl phospholipid remodeling. Our results support the deleterious role of iPLA2β in severe obesity associated NAFLD. Copyright © 2016 Elsevier B.V. All rights reserved.

Reduced inflammatory response and increased microcirculatory disturbances during hepatic ischemia-reperfusion injury in steatotic livers of ob/ob mice

PubMed Central

Hasegawa, Tadashi; Ito, Yoshiya; Wijeweera, Jayanthika; Liu, Jie; Malle, Ernst; Farhood, Anwar; McCuskey, Robert S.; Jaeschke, Hartmut

2016-01-01

Steatosis is a major risk factor for complications after liver surgery. Since neutrophil cytotoxicity is critical for ischemia-reperfusion injury in normal livers, the aim of the present study was to evaluate whether an exaggerated inflammatory response could cause the increased injury in steatotic livers. In C57Bl/6 mice, 60 min of warm hepatic ischemia triggered a gradual increase in hepatic neutrophil accumulation during reperfusion with peak levels of 100-fold over baseline at 12 h of reperfusion. Neutrophil extravasation and a specific neutrophil-induced oxidant stress (immunostaining for hypochlorous acid-modified epitopes) started at 6 h of reperfusion and peaked at 12–24 h. Ob/ob mice, which had a severe macrovesicular steatosis, suffered significantly higher injury (alanine transaminase activity: 18,000 ± 2,100 U/l; 65% necrosis) compared with lean littermates (alanine transaminase activity: 4,900 ± 720 U/l; 24% necrosis) at 6 h of reperfusion. However, 62% fewer neutrophils accumulated in steatotic livers. This correlated with an attenuated increase in mRNA levels of several proinflammatory genes in ob/ob mice during reperfusion. In contrast, sham-operated ob/ob mice had a 50% reduction in liver blood flow and 35% fewer functional sinusoids compared with lean littermates. These deficiencies in liver blood flow and the microcirculation were further aggravated only in ob/ob mice during reperfusion. The attenuated inflammatory response and reduced neutrophil-induced oxidant stress observed in steatotic livers during reperfusion cannot be responsible for the dramatically increased injury in ob/ob mice. In contrast, the aggravated injury appears to be mediated by ischemic necrosis due to massive impairment of blood and oxygen supply in the steatotic livers. PMID:17307725

Complete Genome Sequence of Escherichia coli Strain M8, Isolated from ob/ob Mice

PubMed Central

Siddharth, Jay; Membrez, Mathieu; Chakrabarti, Anirikh; Betrisey, Bertrand; Chou, Chieh Jason

2017-01-01

ABSTRACT Escherichia coli is one of the common inhabitants of the mammalian gastrointestinal track. We isolated a strain from an ob/ob mouse and performed whole-genome sequencing, which yielded a chromosome of ~5.1 Mb and three plasmids of ~160 kb, ~6 kb, and ~4 kb. PMID:28572322

Leptin differentially regulates STAT3 activation in the ob/ob mice adipose mesenchymal stem cells

USDA-ARS?s Scientific Manuscript database

Leptin-deficient genetically obese ob/ob mice exhibit adipocyte hypertrophy and hyperplasia as well as elevated adipose tissue and systemic inflammation. Studies have shown that multipotent stem cells isolated from adult adipose tissue can differentiate into adipocytes ex vivo and thereby contribute...

Kefir improves fatty liver syndrome by inhibiting the lipogenesis pathway in leptin-deficient ob/ob knockout mice.

PubMed

Chen, H-L; Tung, Y-T; Tsai, C-L; Lai, C-W; Lai, Z-L; Tsai, H-C; Lin, Y-L; Wang, C-H; Chen, C-M

2014-09-01

Fatty liver disease is commonly associated with obesity, insulin resistance and diabetes. Severe fatty liver is sometimes accompanied by steatohepatitis and may lead to the development of hepatocellular carcinoma. At present, there is no effective treatment for non-alcoholic fatty liver disease (NAFLD); thus, recent investigations have focused on developing effective therapeutics to treat this condition. This study aimed to evaluate the effects of kefir on the hepatic lipid metabolism of ob/ob mice, which are commonly used to model fatty liver disease. In this study, we used leptin receptor-deficient ob/ob mice as an animal disease model of NAFLD. Six-week-old ob/ob mice were orally administered the dairy product kefir (140 mg kg(-1) of body weight (BW) per day) for 4 weeks. The data demonstrated that kefir improved fatty liver syndrome on BW, energy expenditure and basal metabolic rate by inhibiting serum glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) activities (P<0.05) and by decreasing the triglyceride (TG) and total cholesterol (TC) contents of the liver (P<0.05). Oral kefir administration also significantly reduced the macrovesicular fat quantity in liver tissue. In addition, kefir markedly decreased the expression of the genes sterol regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) (P<0.05) but not the expression of peroxisome proliferator-activated receptor α (PPARα) or hepatic carnitine palmitoyltransferase-1α (CPT1α) in the livers of ob/ob mice. On the basis of these results, we conclude that kefir improves NAFLD on BW, energy expenditure and basal metabolic rate by inhibiting the lipogenesis pathway and that kefir may have the potential for clinical application to the prevention or treatment of NAFLD.

Geochemistry of obsidian from Krasnoe Lake on the Chukchi Peninsula (Northeastern Siberia)

NASA Astrophysics Data System (ADS)

Popov, V. K.; Grebennikov, A. V.; Kuzmin, Ya. V.; Glascock, M. D.; Nozdrachev, E. A.; Budnitsky, S. Yu.; Vorobey, I. E.

2017-09-01

This report considers features of the geochemical composition of obsidian from beach sediments of Krasnoe Lake along the lower course of the Anadyr River, as well as from lava-pyroclastic rocks constituting the lake coastal outcrops and the surrounding branches of Rarytkin Ridge. The two geochemical types of obsidian, for the first time distinguished and researched, correspond in their chemical composition to lavas and ignimbrite-like tuffs of rhyolites from the Rarytkin area. The distinguished types represent the final stage of acidic volcanism in the West Kamchatkan-Koryak volcanic belt. It was assumed that the accumulation of obsidian in coastal pebble beds was caused by the erosion of extrusive domes and pyroclastic flows. The geochemical studies of obsidian artifacts from archeological sites of the regions of the Sea of Okhotsk, the Kolyma River, and the Chukchi Peninsula along with the correlation of geological and archeological samples show that Krasnoe Lake was an important source of "archeological" obsidian in Northeastern Siberia.

Genetic ablation of phosphatidylcholine transfer protein/StarD2 in ob/ob mice improves glucose tolerance without increasing energy expenditure.

PubMed

Krisko, Tibor I; LeClair, Katherine B; Cohen, David E

2017-03-01

Phosphatidylcholine transfer protein (PC-TP; synonym StarD2) is highly expressed in liver and oxidative tissues. PC-TP promotes hepatic glucose production during fasting and aggravates glucose intolerance in high fat fed mice. However, because PC-TP also suppresses thermogenesis in brown adipose tissue (BAT), its direct contribution to obesity-associated diabetes in mice remains unclear. Here we examined the effects of genetic PC-TP ablation on glucose homeostasis in leptin-deficient ob/ob mice, which exhibit both diabetes and altered thermoregulation. Mice lacking both PC-TP and leptin (Pctp -/- ;ob/ob) were prepared by crossing Pctp -/- with ob/+ mice. Glucose homeostasis was assessed by standard assays, and energy expenditure was determined by indirect calorimetry using a comprehensive laboratory animal monitoring system, which also recorded physical activity and food intake. Body composition was determined by NMR and hepatic lipids by enzymatic assays. Core body temperature was measured using a rectal thermocouple probe. Pctp -/- ;ob/ob mice demonstrated improved glucose homeostasis, as evidenced by markedly improved glucose and pyruvate tolerance tests, without changes in insulin tolerance. However, there were no differences in EE at any ambient temperature. There were also no effects of PC-TP expression on physical activity, food intake or core body temperature. Improved glucose tolerance in Pctp -/- ;ob/ob mice in the absence of increases in energy expenditure or core body temperature indicates a direct pathogenic role for PC-TP in diabetes in leptin deficient mice. Copyright © 2016 Elsevier Inc. All rights reserved.

EC FP6 Siberia-focused Enviro-RISKS Project and its Outcomes

NASA Astrophysics Data System (ADS)

Baklanov, A. A.; Gordov, E. P.

2009-04-01

The FP6 Project "Man-induced Environmental Risks: Monitoring, Management and Remediation of Man-made Changes in Siberia" (Enviro-RISKS) strategic objective is to facilitate elaboration of solid scientific background and understanding of man-made associated environmental risks, their influence on all aspects of regional environment and optimal ways for it remediation by means of coordinated initiatives of a range of relevant RTD projects as well as to achieve their improved integration thus giving the projects additional synergy in current activities and potential for practical applications. List of Partners includes 3 leading European research organizations, 6 leading Russian research organizations (5 - located in Siberia) and 1 organization from Kazakhstan. Additionally several Russian and European research organizations joined to the Project as Associated Partners. Scientific background and foundation for the project performance is formed by a number of different levels RTD projects carried out by Partners and devoted to near all aspects of the theme. The set comprise coordinated/performed by partners EC funded thematic international projects, Russian national projects and other projects performed by NIS partners. Project outcomes include, in particular, development and support of the bilingual Enviro-RISKS web portal (http://risks.scert.ru/) as the major tool for disseminations of environmental information and project results; achieved level of development of Siberia Integrated Regional Study (SIRS, http://sirs.scert.ru/), which is the Siberia-focused NEESPI Environmental Mega-Project ongoing under the auspices of the Siberian Branch of the Russian Academy of Sciences. The main Project outcome are Memorandum on the state of the art of environmental RTD activity in Siberia and Recommendations on future environmental RTD activity in Siberia elaborated by four Working Experts Groups working in most important for Siberia Thematic Focuses. Three Thematic Focuses

Manta A New BroadBand OBS

NASA Astrophysics Data System (ADS)

Hello, Y.; Yegikyan, M.; Charvis, P.; Philippe, O.

2017-12-01

Manta is a new BroadBand OBS developed at Geoazur and commercialized by Osean. The design is inspired by 3-years autonomy MUG-OBS a Multiparameter Ocean Bottom System which carry a lot of sort of sensor types. As Mug-OBS, Manta-OBS rated 6000m is designed to resist a trawling. All the components are non corrosive such polyethylene, titanium and buoyancy is ensured by syntactic foam. Equipped in standard version with a Trillium compact OBS Manta has an autonomy of 18 months, but can accept on its 4 input channels any kind of signal as low as from an hydrophone or larger from other type of a seismometer or accelerometer. Tri-axial geophones unit (2 Hz or 4.5 Hz ) can replace the seismometer and will expend the lifespan for the instrument. The seismometer is encapsulated in a central well established by four panels of the main structure to protect it from sea current convection and is decoupled from main chassis. An health bulletin is recoverable by acoustic any time to facilitate the installation and during a visit when instrument is deployed. Main parameters for acquisition can be changed by acoustics command from surface at any time. Once at the bottom, release for the main sensor installation is programmed on a timer but controlled by the tilt of the OBS. If the tilt is too important based on programmed limits, sensor will not released automatically, but this can be forced by acoustic command after returning the tilt informations to the boat operator. Manta is equipped with flash light and AIS system for easy location at recovery, and can also send it's position by Iridium satellite in case of an unexpected ascent such caused by a possible trawling if deployed in shallow water. Clock drift calculation is automatically made against GPS time signal once the OBS return at the surface. The recovery of the OBS is initiated by an acoustic command. These new features made Manta a very versatile instrument for monitoring earthquakes.

Tumour necrosis factor-α inhibition with lenalidomide alleviates tissue oxidative injury and apoptosis in ob/ob obese mice.

PubMed

Zhu, Xiaoling; Jiang, Shasha; Hu, Nan; Luo, Fuling; Dong, Hailong; Kang, Yu-Ming; Jones, Kyla R; Zou, Yunzeng; Xiong, Lize; Ren, Jun

2014-07-01

Lenalidomide (Revlimid; Selleck Chemicals, Houston, TX, USA), an analogue of thalidomide, possesses potent cytokine modulatory capacity through inhibition of cytokines such as tumour necrosis factor (TNF)-α, a cytokine pivotal for the onset and development of complications in obesity and diabetes mellitus. The present study was designed to evaluate the effect of lenalidomide on oxidative stress, protein and DNA damage in multiple organs in an ob/ob murine model of obesity. To this end, C57BL/6 lean and ob/ob obese mice were administered lenalidomide (50 mg/kg per day, p.o.) for 5 days. Oxidative stress, protein and DNA damage were assessed using the conversion of reduced glutathione (GSH) to oxidized glutathione (GSSG), carbonyl formation and Comet assay, respectively. Apoptosis was evaluated using caspase 3 activity, and levels of Bax, Bcl-2, Bip, caspase 8, caspase 9 and TNF-α were assessed using western blot analysis. Lenalidomide treatment did not affect glucose clearance in lean or ob/ob mice. Obese mice exhibited a reduced GSH/GSSG ratio in the liver, gastrocnemius skeletal muscle and small intestine, as well as enhanced protein carbonyl formation, DNA damage and caspase 3 activity in the liver, kidney, skeletal muscle and intestine; these effects were alleviated by lenalidomide, with the exception of obesity-associated DNA damage in the liver and kidney. Western blot analysis revealed elevated TNF-α, Bax, Bcl-2, Bip, caspase 8 and caspase 9 in ob/ob mice with various degrees of reversal by lenalidomide treatment. Together, these data indicate that lenalidomide protects against obesity-induced tissue injury and protein damage, possibly in association with antagonism of cytokine production and cytokine-induced apoptosis and oxidative stress. © 2014 Wiley Publishing Asia Pty Ltd.

Tau hyperphosphorylation in the brain of ob/ob mice is due to hypothermia: Importance of thermoregulation in linking diabetes and Alzheimer's disease.

PubMed

Gratuze, Maud; El Khoury, Noura B; Turgeon, Andréanne; Julien, Carl; Marcouiller, François; Morin, Françoise; Whittington, Robert A; Marette, André; Calon, Frédéric; Planel, Emmanuel

2017-02-01

Over the last few decades, there has been a significant increase in epidemiological studies suggesting that type 2 diabetes (T2DM) is linked to a higher risk of Alzheimer's disease (AD). However, how T2DM affects AD pathology, such as tau hyperphosphorylation, is not well understood. In this study, we investigated the impact of T2DM on tau phosphorylation in ob/ob mice, a spontaneous genetic model of T2DM. Tau phosphorylation at the AT8 epitope was slightly elevated in 4-week-old ob/ob mice while 26-week-old ob/ob mice exhibited tau hyperphosphorylation at multiple tau phospho-epitopes (Tau1, CP13, AT8, AT180, PHF1). We then examined the mechanism of tau hyperphosphorylation and demonstrated that it is mostly due to hypothermia, as ob/ob mice were hypothermic and normothermia restored tau phosphorylation to control levels. As caffeine has been shown to be beneficial for diabetes, obesity and tau phosphorylation, we, therefore, used it as therapeutic treatment. Unexpectedly, chronic caffeine intake exacerbated tau hyperphosphorylation by promoting deeper hypothermia. Our data indicate that tau hyperphosphorylation is predominately due to hypothermia consequent to impaired thermoregulation in ob/ob mice. This study establishes a novel link between diabetes and AD, and reinforces the importance of recording body temperature to better assess the relationship between diabetes and AD. Copyright © 2016 Elsevier Inc. All rights reserved.

The Last Glacial Ecosystems of North Siberia: Permafrost-Sealed Evidence from Fossiliferous Cryolithic Formations

NASA Astrophysics Data System (ADS)

Chlachula, Jiri

2017-04-01

Multi-proxy palaeoecology and geoarchaeology records released from degrading permafrost in the Yana River Basin and the tributary valleys (66-67°N) confirm the past existence of natural conditions for sustainment of the Pleistocene megafauna as well as the last glacial peopling of this sub-polar area. Well-preserved and taxonomically diverse large fossil fauna skeletal remains sealed in the Pleistocene colluvial and alluvial-plain formations in intact geological positions 10-20 m above the present river and scattered on gravelly river banks after their erosion from the primary geo-contexts attest to a high biotic potential of the Late Pleistocene (MIS 3-2) sub-Arctic forest-tundra. Pollen records from the ancient interstratified boggy sediments and megafauna coprolites (14C-dated to 41-38 ka BP) show a predominance of the Siberian larch, dwarf birch and willow in the local vegetation cover accompanied by grassy communities during the mid-Last Glacial stage not dissimilar from the present northern taiga forest. Articulated and humanly used/worked fauna bones (mammoth, rhinoceros, horse, bison and reindeer among other species) point to co-existence of the large animals with the Upper Palaeolithic people within the mosaic open riverine ecosystems of the late Last Ice Age. The time-trangressive macro-lithic stone industry produced from pre-selected river gravel cobbles document some specific ways of human environmental adjustment to past periglacial settings. Geomorphology and hydrogeology indices of field mappings in congruence with the long-term statistical meteorology data illustrate a steadily increasing annual temperature trend in the broader Yana-Adycha Basins (current MAT -14.5°C) that triggers accelerated permafrost thaw across the Verkhoyansk Region of NE Siberia, particularly the lowlands, similarly as in the Indigirka and Kolyma Basins further East. The regional fluvial discharge is most dynamic during late spring due to the cumulative effects of snow

Automated identification of OB associations in M31

NASA Technical Reports Server (NTRS)

Magnier, Eugene A.; Battinelli, Paolo; Lewin, Walter H. G.; Haiman, Zoltan; Paradijs, Jan Van; Hasinger, Guenther; Pietsch, Wolfgang; Supper, Rodrigo; Truemper, Joachim

1993-01-01

A new identification of OB associations in M31 has been performed using the Path Linkage Criterion (PLC) technique of Battinelli (1991). We found 174 associations with a very small contamination (less than 5%) by random clumps of stars. The expected total number and average size of OB associations in the region of M 31 covered by our data set (Magnier et al. 1992) are approximately 280 and approximately 90 pc, respectively. M31 associations therefore have sizes similar to those of OB associations observed in nearby galaxies, so that we can consider them to be classical OB associations. This list of OB associations will be used for the study of the spatial distribution of OB associations and their correlation with other objects. Taking into account the fact that we do not cover the entire disk of M31, we extrapolate a total number of association in M31 of approximately 420.

The fluvial geochemistry of the rivers of Eastern Siberia: I. tributaries of the Lena River draining the sedimentary platform of the Siberian Craton

NASA Astrophysics Data System (ADS)

Huh, Youngsook; Tsoi, Mai-Yin; Zaitsev, Alexandr; Edmond, John M.

1998-05-01

The response of continental weathering rates to changing climate and atmospheric PCO 2 is of considerable importance both to the interpretation of the geological sedimentary record and to predictions of the effects of future anthropogenic influences. While comprehensive work on the controlling mechanisms of contemporary chemical and mechanical weathering has been carried out in the tropics and, to a lesser extent, in the strongly perturbed northern temperate latitudes, very little is known about the peri-glacial environments in the subarctic and arctic. Thus, the effects of climate, essentially temperature and runoff, on the rates of atmospheric CO 2 consumption by weathering are not well quantified at this climatic extreme. To remedy this lack a comprehensive survey has been carried out of the geochemistry of the large rivers of Eastern Siberia, the Lena, Yana, Indigirka, Kolyma, Anadyr, and numerous lesser streams which drain a pristine, high-latitude region that has not experienced the pervasive effects of glaciation and subsequent anthropogenic impacts common to western Eurasia and North America. The scale of the terrain sampled, in terms of area, is comparable to that of the continental United States or the Amazon/Orinoco and includes a similarly diverse range of geologic and climatic environments. In this paper the chemical fluxes from the western region, the very large, ancient, and geologically stable sedimentary basin, Precambrian to Quaternary, of the Siberian Platform will be presented and compared to published results from analogous terrains in the tropical basins of China. While the range in the chemical signatures of the various tributaries included here (˜60 sampled) is large, this mainly reflects lithology rather than the weathering environment. The areal chemical fluxes are comparable to those of the Chinese rivers, being dominated by the dissolution of carbonates and evaporites. The net consumption of atmospheric CO 2 by aluminosilicate

Switching performance of OBS network model under prefetched real traffic

NASA Astrophysics Data System (ADS)

Huang, Zhenhua; Xu, Du; Lei, Wen

2005-11-01

Optical Burst Switching (OBS) [1] is now widely considered as an efficient switching technique in building the next generation optical Internet .So it's very important to precisely evaluate the performance of the OBS network model. The performance of the OBS network model is variable in different condition, but the most important thing is that how it works under real traffic load. In the traditional simulation models, uniform traffics are usually generated by simulation software to imitate the data source of the edge node in the OBS network model, and through which the performance of the OBS network is evaluated. Unfortunately, without being simulated by real traffic, the traditional simulation models have several problems and their results are doubtable. To deal with this problem, we present a new simulation model for analysis and performance evaluation of the OBS network, which uses prefetched IP traffic to be data source of the OBS network model. The prefetched IP traffic can be considered as real IP source of the OBS edge node and the OBS network model has the same clock rate with a real OBS system. So it's easy to conclude that this model is closer to the real OBS system than the traditional ones. The simulation results also indicate that this model is more accurate to evaluate the performance of the OBS network system and the results of this model are closer to the actual situation.

All-trans retinoic acid stimulates gene expression of the cardioprotective natriuretic peptide system and prevents fibrosis and apoptosis in cardiomyocytes of obese ob/ob mice.

PubMed

Manolescu, Daniel-Constantin; Jankowski, Marek; Danalache, Bogdan A; Wang, Donghao; Broderick, Tom L; Chiasson, Jean-Louis; Gutkowska, Jolanta

2014-10-01

In hypertensive rodents, retinoic acid (RA) prevents adverse cardiac remodelling and improves myocardial infarction outcome, but its role in obesity-related changes of cardiac tissue are unclear. We hypothesized that all-trans RA (ATRA) treatment will improve the cardioprotective oxytocin-natriuretic peptides (OT-NP) system, preventing apoptosis and collagen accumulation in hearts of ob/ob mice, a mouse model of obesity and insulin resistance. Female 9-week-old B6.V-Lep/J ob/ob mice (n = 16) were divided into 2 groups: 1 group (n = 8) treated with 100 μg of ATRA dissolved in 100 μL of corn oil (vehicle) delivered daily (∼2 μg·g body weight(-1)·day(-1)) by stomach intubation for 16 days, and 1 group (n = 8) that received the vehicle alone. A group of nonobese littermate mice (n = 9) served as controls. Ob/ob mice exhibited obesity, hyperglycaemia, and downregulation of the cardiac OT-NP system, including the mRNA for the transcription factor GATA4, OT receptor and brain NP, and the protein expression for endothelial nitric oxide synthase. Hearts from ob/ob mice also demonstrated increased apoptosis and collagen accumulation. ATRA treatment induced weight loss and decreased adipocytes diameter in the visceral fat, thus reducing visceral obesity, which is associated with a high risk for cardiovascular disease. RA treatment was associated with a reduction in hyperglycemia and a normalization of the OT-NP system's expression in the hearts of ob/ob mice. Furthermore, ATRA treatment prevented apoptosis and collagen accumulation in hearts of ob/ob mice. The present study indicates that ATRA treatment was effective in restoring the cardioprotective OT-NP system and in preventing abnormal cardiac remodelling in the ob/ob mice.

NASA Soil Moisture Active Passive Mission Status and Science Highlights

NASA Technical Reports Server (NTRS)

Yueh, Simon; Entekhabi, Dara; O'Neill, Peggy; Entin, Jared

2017-01-01

The Soil Moisture Active Passive (SMAP) observatory was launched January 31, 2015, and its L-band radiometer and radar instruments became operational during April 2015. This paper provides a summary of the quality assessment of its baseline soil moisture and freeze/thaw products as well as an overview of new products. The first new product explores the Backus Gilbert optimum interpolation based on the oversampling characteristics of the SMAP radiometer. The second one investigates the disaggregation of the SMAP radiometer data using the European Space Agency's Sentinel-1 C-band synthetic aperture radar (SAR) data to obtain soil moisture products at about 1 to 3 km resolution. In addition, SMAPs L-band data have been found useful for many scientific applications, including depictions of water cycles, vegetation opacity, ocean surface salinity and hurricane ocean surface wind mapping. Highlights of these new applications will be provided.The SMAP soil moisture, freeze/taw state and SSSprovide a synergistic view of water cycle. For example, Fig.7 illustrates the transition of freeze/thaw state, change of soilmoisture near the pole and SSS in the Arctic Ocean fromApril to October in 2015 and 2016. In April, most parts ofAlaska, Canada, and Siberia remained frozen. Melt onsetstarted in May. Alaska, Canada, and a big part of Siberia havebecome thawed at the end of May; some freshwater dischargecould be found near the mouth of Mackenzie in 2016, but notin 2015. The soil moisture appeared to be higher in the Oband Yenisei river basins in Siberia in 2015. As a result,freshwater discharge was more widespread in the Kara Seanear the mouths of both rivers in June 2015 than in 2016. TheNorth America and Siberia have become completely thawedin July. After June, the freshwater discharge from other riversinto the Arctic, indicated by blue, also became visible. Thefreeze-up started in September and the high latitude regionsin North America and Eurasia became frozen. Comparing

OB's high voltage laboratory

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

Not Available

1966-01-01

The January issue of Hi-Tension News provides a detailed description of the advanced surge test facilities and procedures in daily operation at the OB High Voltage Laboratory in Barberton, Ohio. Technical competences achieved in this laboratory contribute to the essential factors of design confirmation to basic studies of ehv insulation systems, conductor and hardware performance, and optimum tower construction. Known throughout the industry for authenticity of its full scale, all weather outdoor testing, OB's High Voltage Laboratory is a full-fledged participant in the NEMA-sponsored program to make testing facilities available on a cooperative basis.

Database of Alluvial Radiocarbon Dates in European Russia and Siberia and its Palaeohydrological Interpretation

NASA Astrophysics Data System (ADS)

Matlakhova, Ekaterina; Panin, Andrei

2017-04-01

We collected and analyzed published radiocarbon dates from East European Plain (EEP) and Siberia to pick absolute dates on alluvial and associated deposits. After filtering unreliable dates, 1000 radiocarbon dates from EEP and 500 from Siberia were included into the database. Each date was supplied with information on geographic location and coordinates, catchment area, geomorphological position, characteristics of geological section and dated materials. Also the information about published sources was given. Documented sections refer to fluvial forms in a wide range of catchment sizes. To extract palaeohydrological signal we used two kinds of proxies: sedimentological and geomorphological. We used the following indicators of low activity: organic horizons (soil, peat) in overbank alluvium, balka bottoms and gully fans, small river palaeochannels; and the following indicators of high activity: active sedimentation on river floodplains (burial of organic horizons), balka bottoms and gully fans, erosion by flood flows on floodplains, in bottoms of balkas and gullies, river incision, big palaeochannels, channel avulsions and chute cutoffs. 
 Each date that received palaeohydrological interpretation was regarded as the indicator of a particular Local Palaeohydrological Event. Combined probability density functions of high- and low-activity dates were used to detect time intervals of different palaeohydrological status. For EEP after low fluvial activity during LGM two palaeohydrological epochs were designated: extremely high activity in the end of MIS 2 (ca. 18-11.7 ka b2k), and much lower activity in the Holocene. Within the Holocene two hierarchical levels of hydroclimatic variability were designated according to their duration and magnitude - regional palaeohydrological phases (centuries to few millennia) and regional palaeofluvial episodes (decades to few centuries). Tendency is rather clear of activity lowering in the first half and rise in the second half of

The CIDA Variability Survey of Orion OB1. I. The Low-Mass Population of Ori OB1a and 1b

NASA Astrophysics Data System (ADS)

Briceño, Cesar; Calvet, Nuria; Hernández, J.; Vivas, A. K.; Hartmann, Lee; Downes, J. J.; Berlind, Perry

2005-02-01

We present results of a large-scale, multiepoch optical survey of the Orion OB1 association, carried out with the QUEST camera at the Venezuela National Astronomical Observatory. We identify for the first time the widely spread low-mass, young population in the Ori OB1a and OB1b subassociations. Candidate members were picked up by their variability in the V band and position in color-magnitude diagrams. We obtained spectra to confirm membership. In a region spanning ~68 deg2, we found 197 new young stars; of these, 56 are located in the Ori OB1a subassociation and 141 in Ori OB1b. The spatial distribution of the low-mass young stars is spatially coincident with that of the high-mass members but suggests a much sharper edge to the association. Comparison with the spatial extent of molecular gas and extinction maps indicates that the subassociation Ori OB1b is concentrated within a ringlike structure of radius ~2°(~15 pc at 440 pc), centered roughly on the star ɛ Ori in the Orion belt. The ring is apparent in 13CO and corresponds to a region with an extinction AV>=1. The stars exhibiting strong Hα emission, an indicator of active accretion, are found along this ring, whereas the center is populated with weak Hα-emitting stars. In contrast, Ori OB1a is located in a region devoid of gas and dust. We identify a grouping of stars within a ~3 deg2 area located in Ori OB1a, roughly clustered around the B2 star 25 Ori. The Herbig Ae/Be star V346 Ori is also associated with this grouping, which could be an older analog of σ Ori. Using several sets of evolutionary tracks, we find an age of 7-10 Myr for Ori OB1a and of ~4-6 Myr for Ori OB1b, consistent with previous estimates from OB stars. Indicators such as the equivalent width of Hα and near-IR excesses show that the number of accreting low-mass stars decreases sharply between Ori OB1b and Ori OB1a. These results indicate that although a substantial fraction of accreting disks remain at ages ~5 Myr, inner disks are

Dissolved organic matter composition and biodegradability in a permafrost-dominated watershed network in central Siberia

NASA Astrophysics Data System (ADS)

Coble, A. A.; Rodriguez-Cardona, B.; Wymore, A.; Prokishkin, A. S.; Kolosov, R.; McDowell, W. H.

2016-12-01

Thawing permafrost soils can mobilize large quantities of dissolved organic matter (DOM) from soils to headwater streams, and DOM may undergo rapid transformations in streams and rivers in transit to the Arctic Ocean. With climate change an increased frequency of fire is also expected, which will further alter the DOM entering streams, and may contribute to changes in its biodegradability. Elucidating how DOM composition varies across a fire gradient within a river network underlain by continuous permafrost will therefore improve our understanding of the impact of climate change on Arctic ecosystems and its role in the global carbon cycle. To determine DOM composition we measured optical properties via excitation-emission matrices (EEMs) and subsequent parallel factor analysis across a spatially extensive collection of sites in central Siberia. Within a subset of streams in the Nizhnyaya Tunguska watershed network, we also measured biodegradable dissolved organic carbon (BDOC) incubated at in situ temperatures over a 7 day period during spring freshet on two dates in early June. Despite clear changes in optical properties of DOM and background DOC concentration along the fire gradient (range: 3 to >100 y since burn) BDOC did not vary systematically with years since fire for either incubation date. In the first incubation conducted near peak flow BDOC ranged from negligible to 7.6% (BDOC concentration = negligible to 1.4 mg C L-1) within a 7 day period. In the second incubation conducted 5 days later BDOC was negligible across all sites (as both a percentage and a concentration). Our results suggest that DOC exported from permafrost soils in the central Siberian plateau is relatively unreactive at in situ temperatures over 7 day time scales, which contrasts with previous studies conducted in watersheds underlain with Yedoma outcrops where biodegradability comprises a large fraction of DOC. Our preliminary results suggest that melting of permafrost soils in central

Leptin Reduces the Expression and Increases the Phosphorylation of the Negative Regulators of GLUT4 Traffic TBC1D1 and TBC1D4 in Muscle of ob/ob Mice

PubMed Central

Sáinz, Neira; Rodríguez, Amaia; Catalán, Victoria; Becerril, Sara; Ramírez, Beatriz; Lancha, Andoni; Burgos-Ramos, Emma; Gómez-Ambrosi, Javier; Frühbeck, Gema

2012-01-01

Leptin improves insulin sensitivity in skeletal muscle. Our goal was to determine whether proteins controlling GLUT4 traffic are altered by leptin deficiency and in vivo leptin administration in skeletal muscle of wild type and ob/ob mice. Leptin-deficient ob/ob mice were divided in three groups: control, leptin-treated (1 mg/kg/d) and leptin pair-fed ob/ob mice. Microarray analysis revealed that 1,546 and 1,127 genes were regulated by leptin deficiency and leptin treatment, respectively. Among these, we identified 24 genes involved in intracellular vesicle-mediated transport in ob/ob mice. TBC1 domain family, member 1 (Tbc1d1), a negative regulator of GLUT4 translocation, was up-regulated (P = 0.001) in ob/ob mice as compared to wild types. Importantly, leptin treatment reduced the transcript levels of Tbc1d1 (P<0.001) and Tbc1d4 (P = 0.004) in the leptin-treated ob/ob as compared to pair-fed ob/ob animals. In addition, phosphorylation levels of TBC1D1 and TBC1D4 were enhanced in leptin-treated ob/ob as compared to control ob/ob (P = 0.015 and P = 0.023, respectively) and pair-fed ob/ob (P = 0.036 and P = 0.034, respectively) mice. Despite similar GLUT4 protein expression in wild type and ob/ob groups a different immunolocalization of this protein was evidenced in muscle sections. Leptin treatment increased GLUT4 immunoreactivity in gastrocnemius and extensor digitorum longus sections of leptin-treated ob/ob mice. Moreover, GLUT4 protein detected in immunoprecipitates from TBC1D4 was reduced by leptin replacement compared to control ob/ob (P = 0.013) and pair-fed ob/ob (P = 0.037) mice. Our findings suggest that leptin enhances the intracellular GLUT4 transport in skeletal muscle of ob/ob animals by reducing the expression and activity of the negative regulators of GLUT4 traffic TBC1D1 and TBC1D4. PMID:22253718

Deficient copper concentrations in dried-defatted hepatic tissue from ob/ob mice: A potential model for study of defective copper regulation in metabolic liver disease.

PubMed

Church, Stephanie J; Begley, Paul; Kureishy, Nina; McHarg, Selina; Bishop, Paul N; Bechtold, David A; Unwin, Richard D; Cooper, Garth J S

2015-05-08

Ob/ob mice provide an animal model for non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH) in patients with obesity and type-2 diabetes. Low liver copper has been linked to hepatic lipid build-up (steatosis) in animals with systemic copper deficiency caused by low-copper diets. However, hepatic copper status in patients with NAFLD or NASH is uncertain, and a validated animal model useful for the study of hepatic copper regulation in common forms of metabolic liver disease is lacking. Here, we report parallel measurements of essential metal levels in whole-liver tissue and defatted-dried liver tissue from ob/ob and non-obese control mice. Measurements in whole-liver tissue from ob/ob mice at an age when they have developed NAFLD/NASH, provide compelling evidence for factitious lowering of copper and all other essential metals by steatosis, and so cannot be used to study hepatic metal regulation in this model. By marked contrast, metal measurements in defatted-dried liver samples reveal that most essential metals were actually normal and indicate specific lowering of copper in ob/ob mice, consistent with hepatic copper deficiency. Thus ob/ob mice can provide a model useful for the study of copper regulation in NAFLD and NASH, provided levels are measured in defatted-dried liver tissue. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Reanalysis Data Evaluation to Study Temperature Extremes in Siberia

NASA Astrophysics Data System (ADS)

Shulgina, T. M.; Gordov, E. P.

2014-12-01

Ongoing global climate changes are strongly pronounced in Siberia by significant warming in the 2nd half of 20th century and recent extreme events such as 2010 heat wave and 2013 flood in Russia's Far East. To improve our understanding of observed climate extremes and to provide to regional decision makers the reliable scientifically based information with high special and temporal resolution on climate state, we need to operate with accurate meteorological data in our study. However, from available 231 stations across Siberia only 130 of them present the homogeneous daily temperature time series. Sparse, station network, especially in high latitudes, force us to use simulated reanalysis data. However those might differ from observations. To obtain reliable information on temperature extreme "hot spots" in Siberia we have compared daily temperatures form ERA-40, ERA Interim, JRA-25, JRA-55, NCEP/DOE, MERRA Reanalysis, HadEX2 and GHCNDEX gridded datasets with observations from RIHMI-WDC/CDIAC dataset for overlap period 1981-2000. Data agreement was estimated at station coordinates to which reanalysis data were interpolated using modified Shepard method. Comparison of averaged over 20 year annual mean temperatures shows general agreement for Siberia excepting Baikal region, where reanalyses significantly underestimate observed temperature behavior. The annual temperatures closest to observed one were obtained from ERA-40 and ERA Interim. Furthermore, t-test results show homogeneity of these datasets, which allows one to combine them for long term time series analysis. In particular, we compared the combined data with observations for percentile-based extreme indices. In Western Siberia reanalysis and gridded data accurately reproduce observed daily max/min temperatures. For East Siberia, Lake Baikal area, ERA Interim data slightly underestimates TN90p and TX90p values. Results obtained allows regional decision-makers to get required high spatial resolution (0,25°×0

North Fork Snoqualmie River Basin Wildlife Study.

DTIC Science & Technology

1981-03-01

purposes other than travel. In Olympic National Park , marked mountain goats have been ob- served to descend several thousand feet to a valley floor for...Howard Hanson Reservoir near the mouth of the Green River. The reservoir’s pool was full. These gillnets were the "experimental type " and included...river below the proposed damsite. A secondary purpose was to allow comparisons of the amount and type of habitat in different river sections. We used the

Trace element fractionation and transport in boreal rivers and soil porewaters of permafrost-dominated basaltic terrain in Central Siberia

NASA Astrophysics Data System (ADS)

Pokrovsky, O. S.; Schott, J.; Dupré, B.

2006-07-01

The chemical status of ˜40 major and trace elements (TE) and organic carbon (OC) in pristine boreal rivers draining the basaltic plateau of Central Siberia (Putorana) and interstitial solutions of permafrost soils was investigated. Water samples were filtered in the field through progressively decreasing pore size (5 μm → 0.22 μm → 0.025 μm → 10 kDa → 1 kDa) using cascade frontal filtration technique. Most rivers and soil porewaters exhibit 2-5 times higher than the world average concentration of dissolved (i.e., <0.22 μm) iron (0.03-0.4 mg/L), aluminum (0.03-0.4 mg/L), OC (10-20 mg/L) and various trace elements that are usually considered as immobile in weathering processes (Ti, Zr, Ga, Y, REEs). Ultrafiltration revealed strong relationships between concentration of TE and that of colloidal Fe and Al. According to their partition during filtration and association with colloids, two groups of elements can be distinguished: (i) those weakly dependent on ultrafiltration and that are likely to be present as truly dissolved inorganic species (Li, Na, K, Si, Mn, Mo, Rb, Cs, As, Sb) or, partially (20-30%) associated with small size Fe- and Al-colloids (Ca, Mg, Sr, Ba) and to small (<1-10 kDa) organic complexes (Co, Ni, Cu, Zn), and (ii) elements strongly associated with colloidal iron and aluminum in all ultrafiltrates largely present in 1-100 kDa fraction (Ga, Y, REEs, Pb, V, Cr, Ti, Ge, Zr, Th, U). TE concentrations and partition coefficients did not show any detectable variations between different colloidal fractions for soil porewaters, suprapermafrost flow and surface streams. TE concentration measurements in river suspended particles demonstrated significant contribution (i.e., ⩾30%) of conventionally dissolved (<0.22 μm) forms for usually "immobile" elements such as divalent transition metals, Cd, Pb, V, Sn, Y, REEs, Zr, Hf, Th. The Al-normalized accumulation coefficients of TE in vegetation litter compared to basalts achieve 10-100 for B, Mn, Zn

Oral Administration of Apple Procyanidins Ameliorates Insulin Resistance via Suppression of Pro-Inflammatory Cytokine Expression in Liver of Diabetic ob/ob Mice.

PubMed

Ogura, Kasane; Ogura, Masahito; Shoji, Toshihiko; Sato, Yuichi; Tahara, Yumiko; Yamano, Gen; Sato, Hiroki; Sugizaki, Kazu; Fujita, Naotaka; Tatsuoka, Hisato; Usui, Ryota; Mukai, Eri; Fujimoto, Shimpei; Inagaki, Nobuya; Nagashima, Kazuaki

2016-11-23

Procyanidins, the main ingredient of apple polyphenols, are known to possess antioxidative and anti-inflammatory effects associated closely with the pathophysiology of insulin resistance and type 2 diabetes. We investigated the effects of orally administered apple procyanidins (APCs) on glucose metabolism using diabetic ob/ob mice. We found no difference in body weight or body composition between mice treated with APCs and untreated mice. A 4 week oral administration of APCs containing water [0.5% (w/v)] ameliorated glucose tolerance, insulin resistance, and hepatic gluconeogenesis in ob/ob mice. APCs also suppressed the increase in the level of the pancreatic β-cell. Insulin-stimulated Akt phosphorylation was significantly enhanced; pro-inflammatory cytokine expression levels were significantly decreased, and c-Jun N-terminal kinase phosphorylation was downregulated in the liver of those mice treated with APCs. In conclusion, APCs ameliorate insulin resistance by improving hepatic insulin signaling through suppression of hepatic inflammation in ob/ob mice, which may be a mechanism with possible beneficial health effects of APCs in disturbed glucose metabolism.

Sterculic Oil, a Natural SCD1 Inhibitor, Improves Glucose Tolerance in Obese ob/ob Mice

PubMed Central

Ortinau, Laura C.; Pickering, R. Taylor; Nickelson, Karen J.; Stromsdorfer, Kelly L.; Naik, Chaitasi Y.; Haynes, Rebecca A.; Bauman, Dale E.; Rector, R. Scott; Fritsche, Kevin L.; Perfield, James W.

2012-01-01

Obesity and its metabolic complications are associated with increased expression/activity of stearoyl-CoA desaturase-1 (SCD1), a major regulator of lipid metabolism. Reduction or ablation of this enzyme is associated with an improved metabolic profile and has gained attention as a target for pharmaceutical development. Sterculic oil (SO) is a known inhibitor of SCD1 and may provide a natural approach for treating obesity and/or insulin resistance. The purpose of this study was to evaluate the effects of SO consumption in leptin-deficient ob/ob mice, a model of obesity and insulin resistance. Five-week-old male mice received either an AIN-93G (control) or an AIN-93G diet containing 0.5% SO. After 9 weeks, SO supplementation did not alter food intake or body weight; however, the desaturase indices, a proxy of SCD1 activity, were reduced in liver and adipose tissue of SO-supplemented animals. This reduction was associated with improved glucose and insulin tolerance and attenuated hepatic inflammation in obese ob/ob mice, while no appreciable changes were observed in lean control mice receiving SO. Future studies are needed to better understand the mechanism(s) by which SO is functioning to improve glucose metabolism and to further explore the nutraceutical potential and health implications of SO supplementation. PMID:23209931

Circulation patterns governing October snowfalls in southern Siberia

NASA Astrophysics Data System (ADS)

Bednorz, Ewa; Wibig, Joanna

2017-04-01

This study is focused on early fall season in southern Siberia (50-60 N) and is purposed as a contribution to the discussion on the climatic relevance of October Eurasian snow cover. Analysis is based on the daily snow depth data from 43 stations from years 1980-2012, available in the database of All-Russian Research Institute of Hydrometeorological Information—World Data Centre. The snow cover season in southern Siberia starts in early autumn and the number of days with snowfall varies from less than 5 days in the southernmost zone along the parallel 50 N to more than 25 days in the northeastern part of the analyzed area. October snowfall in southern Siberia is associated with occurrence of negative anomalies of sea level pressure (SLP), usually spreading right over the place of recorded intense snowfall or extending eastward from it. Negative anomalies of air temperature at the 850 hPa geopotential level (T850) occurring with increased cyclonic activity are also observed. Negative T850 anomalies are located west or northwest of the SLP depressions. Counterclockwise circulation around low-pressure systems transports cold Arctic air from the north or even colder Siberian polar air from the east, to the west, and northwest parts of cyclones, and induces negative anomalies of temperature. The pattern of T850 anomalies during heavy snowfalls in the eastern part of the southern Siberia is shifted counterclockwise in regard to SLP anomalies: the strongest negative T850 anomalies are located west or northwest of the SLP depressions.

East Siberia and Bering Sea, Russia

NASA Technical Reports Server (NTRS)

2002-01-01

On June 5, 2001 MODIS captured this true-color image of Eastern Siberia and the Bering Strait. To the right of the image is the western tip of Alaska's St. Lawrence Island. Credit: Jacques Descloitres, MODIS Land Rapid Response Team

Reduction of protein tyrosine phosphatase 1B increases insulin-dependent signaling in ob/ob mice.

PubMed

Gum, Rebecca J; Gaede, Lori L; Koterski, Sandra L; Heindel, Matthew; Clampit, Jill E; Zinker, Bradley A; Trevillyan, James M; Ulrich, Roger G; Jirousek, Michael R; Rondinone, Cristina M

2003-01-01

Protein tyrosine phosphatase 1B (PTP1B) is a negative regulator of insulin receptor (IR) signal transduction and a drug target for treatment of type 2 diabetes. Using PTP1B antisense oligonucleotides (ASOs), effects of decreased PTP1B levels on insulin signaling in diabetic ob/ob mice were examined. Insulin stimulation, prior to sacrifice, resulted in no significant activation of insulin signaling pathways in livers from ob/ob mice. However, in PTP1B ASO-treated mice, in which PTP1B protein was decreased by 60% in liver, similar stimulation with insulin resulted in increased tyrosine phosphorylation of the IR and IR substrate (IRS)-1 and -2 by threefold, fourfold, and threefold, respectively. IRS-2-associated phosphatidylinositol 3-kinase activity was also increased threefold. Protein kinase B (PKB) serine phosphorylation was increased sevenfold in liver of PTP1B ASO-treated mice upon insulin stimulation, while phosphorylation of PKB substrates, glycogen synthase kinase (GSK)-3alpha and -3beta, was increased more than twofold. Peripheral insulin signaling was increased by PTP1B ASO, as evidenced by increased phosphorylation of PKB in muscle of insulin-stimulated PTP1B ASO-treated animals despite the lack of measurable effects on muscle PTP1B protein. These results indicate that reduction of PTP1B is sufficient to increase insulin-dependent metabolic signaling and improve insulin sensitivity in a diabetic animal model.

Sucrose diet induced enzymatic and hormonal responses affecting carbohydrate, lipid and energy metabolism in two species differing in insulin availability: spiny and ob/ob mice.

PubMed

Shafrir, E; Trostler, N

1984-01-01

The low-insulin responding spiny mice (Acomys cahirinus), maintained on a 50% sucrose diet vs isocaloric regular diet, responded with an impressive increase in the activity of hepatic enzymes of glycolysis and lipogenesis and in hyperlipidemia. There was no hyperinsulinemia or hyperglycemia and spiny mice did not gain weight on sucrose due to loss of adipose tissue. Serum T3 levels rose 1.8 fold and the activity of the hepatic mitochondrial FAD-glycerol-3-phosphate oxidase became induced 2.6 fold representing the enhancement of multiple, T3-dependent, energy-consuming metabolic cycles. An increased TG lipolysis in adipose tissue was also observed. C57BL/6J ob/ob mice were markedly hyperinsulinemic and gained weight on sucrose almost as much as those on regular diet, without changes in serum glucose or insulin. Serum triglyceride level decreased, whereas liver triglycerides accumulated markedly. The extent of the increase in hepatic enzyme activities related to lipogenesis was much lower both in the ob/ob mice and their lean siblings, than in spiny mice, but the basal enzyme activities in ob/ob mice were remarkably elevated. Serum T3 level was also elevated already on the regular diet and rose only slightly on sucrose. Basal glycerol phosphate oxidase activity in ob/ob mice exceeded that in spiny mice and rose only marginally on sucrose. Adipose tissue lipolysis was not increased. Thus, sucrose diet by enhancing the T3 production appeared to activate protective mechanism against weight gain in normoinsulinemic spiny mice, whereas the full expression of these mechanisms appeared to be precluded by the hyperinsulinemia of ob/ob mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Will the river Irtysh survive the year 2030? Impact of long-term unsuitable land use and water management of the upper stretch of the river catchment (North Kazakhstan)

NASA Astrophysics Data System (ADS)

Hrkal, Zbyněk; Gadalia, Alain; Rigaudiere, Pierre

2006-07-01

The Irtysh river basin all the way from river spring in China across Kazakhstan as far as the Russian part of Siberia is among the most ecologically endangered and affected regions on our planet. The study provides a summary of the historical reasons for anthropological interventions in this area, which began with the construction of plants of the military—industrial complexes in the forties of the last century during World War II. These plants have a major share in extreme high concentrations of heavy metals in surface as well in groundwaters locally. The Semipalatinsk nuclear polygon plays a specific role as a source of contamination of local waters. The release of top secret data enabled us to gain knowledge about serious problems related to high radioactivity of groundwaters, which should spread uncontrollably through a system of secondary fissures activated by nuclear blasts. Another serious problem in this region is the quantitative aspect of contamination. Model simulations of water balance indicate that large industrial development in the spring area in China and continuously increasing water consumption in Kazakhstan may lead to desiccation of the lower stretch of this large river in Siberia during the summer months of 2030.

Proteomics Analysis of Skeletal Muscle from Leptin-Deficient ob/ob Mice Reveals Adaptive Remodeling of Metabolic Characteristics and Fiber Type Composition.

PubMed

Schönke, Milena; Björnholm, Marie; Chibalin, Alexander V; Zierath, Juleen R; Deshmukh, Atul S

2018-03-01

Skeletal muscle insulin resistance, an early metabolic defect in the pathogenesis of type 2 diabetes (T2D), may be a cause or consequence of altered protein expression profiles. Proteomics technology offers enormous promise to investigate molecular mechanisms underlying pathologies, however, the analysis of skeletal muscle is challenging. Using state-of-the-art multienzyme digestion and filter-aided sample preparation (MED-FASP) and a mass spectrometry (MS)-based workflow, we performed a global proteomics analysis of skeletal muscle from leptin-deficient, obese, insulin resistant (ob/ob) and lean mice in mere two fractions in a short time (8 h per sample). We identified more than 6000 proteins with 118 proteins differentially regulated in obesity. This included protein kinases, phosphatases, and secreted and fiber type associated proteins. Enzymes involved in lipid metabolism in skeletal muscle from ob/ob mice were increased, providing evidence against reduced fatty acid oxidation in lipid-induced insulin resistance. Mitochondrial and peroxisomal proteins, as well as components of pyruvate and lactate metabolism, were increased. Finally, the skeletal muscle proteome from ob/ob mice displayed a shift toward the "slow fiber type." This detailed characterization of an obese rodent model of T2D demonstrates an efficient workflow for skeletal muscle proteomics, which may easily be adapted to other complex tissues. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Neuroglial metabolic compartmentation underlying leptin deficiency in the obese ob/ob mice as detected by magnetic resonance imaging and spectroscopy methods

PubMed Central

Delgado, Teresa C; Violante, Inês R; Nieto-Charques, Laura; Cerdán, Sebastián

2011-01-01

Manganese-Enhanced Magnetic Resonance Imaging (MEMRI), 1H and 13C High-Resolution-Magic Angle Spinning (HR-MAS) Spectroscopy, and genomic approaches were used to compare cerebral activation and neuronal and glial oxidative metabolism in ad libitum fed C57BL6/J leptin-deficient, genetically obese ob/ob mice. T1-weighted Magnetic Resonance Images across the hypothalamic Arcuate and the Ventromedial nuclei were acquired kinetically after manganese infusion. Neuroglial compartmentation was investigated in hypothalamic biopsies after intraperitoneal injections of [1-13C]glucose or [2-13C]acetate. Total RNA was extracted to determine the effects of leptin deficiency in the expression of representative genes coding for regulatory enzymes of hypothalamic energy pathways and glutamatergic neurotransmission. Manganese-Enhanced Magnetic Resonance Imaging revealed enhanced cerebral activation in the hypothalamic Arcuate and Ventromedial nuclei of the ob/ob mice. 13C HR-MAS analysis showed increased 13C accumulation in the hypothalamic glutamate and glutamine carbons of ob/ob mice after the administration of [1-13C]glucose, a primarily neuronal substrate. Hypothalamic expression of the genes coding for glucokinase, phosphofructokinase, pyruvate dehydrogenase, and glutamine synthase was not significantly altered while pyruvate kinase expression was slightly upregulated. In conclusion, leptin deficiency associated with obesity led to increased cerebral activation in the hypothalamic Arcuate and Ventromedial nuclei, concomitant with significant increases in neuronal oxidative metabolism and glutamatergic neurotransmission. PMID:21971349

G Protein–Coupled Receptor Kinase 2, With β-Arrestin 2, Impairs Insulin-Induced Akt/Endothelial Nitric Oxide Synthase Signaling in ob/ob Mouse Aorta

PubMed Central

Taguchi, Kumiko; Matsumoto, Takayuki; Kamata, Katsuo; Kobayashi, Tsuneo

2012-01-01

In type 2 diabetes, impaired insulin-induced Akt/endothelial nitric oxide synthase (eNOS) signaling may decrease the vascular relaxation response. Previously, we reported that this response was negatively regulated by G protein–coupled receptor kinase 2 (GRK2). In this study, we investigated whether/how in aortas from ob/ob mice (a model of type 2 diabetes) GRK2 and β-arrestin 2 might regulate insulin-induced signaling. Endothelium-dependent relaxation was measured in aortic strips. GRK2, β-arrestin 2, and Akt/eNOS signaling pathway proteins and activities were mainly assayed by Western blotting. In ob/ob (vs. control [Lean]) aortas: 1) insulin-induced relaxation was reduced, and this deficit was prevented by GRK2 inhibitor, anti-GRK2 antibody, and an siRNA specifically targeting GRK2. The Lean aorta relaxation response was reduced to the ob/ob level by pretreatment with an siRNA targeting β-arrestin 2. 2) Insulin-stimulated Akt and eNOS phosphorylations were decreased. 3) GRK2 expression in membranes was elevated, and, upon insulin stimulation, this expression was further increased, but β-arrestin 2 was decreased. In ob/ob aortic membranes under insulin stimulation, the phosphorylations of Akt and eNOS were augmented by GRK2 inhibitor. In mouse aorta, GRK2 may be, upon translocation, a key negative regulator of insulin responsiveness and an important regulator of the β-arrestin 2/Akt/eNOS signaling, which is implicated in diabetic endothelial dysfunction. PMID:22688330

G protein-coupled receptor kinase 2, with β-arrestin 2, impairs insulin-induced Akt/endothelial nitric oxide synthase signaling in ob/ob mouse aorta.

PubMed

Taguchi, Kumiko; Matsumoto, Takayuki; Kamata, Katsuo; Kobayashi, Tsuneo

2012-08-01

In type 2 diabetes, impaired insulin-induced Akt/endothelial nitric oxide synthase (eNOS) signaling may decrease the vascular relaxation response. Previously, we reported that this response was negatively regulated by G protein-coupled receptor kinase 2 (GRK2). In this study, we investigated whether/how in aortas from ob/ob mice (a model of type 2 diabetes) GRK2 and β-arrestin 2 might regulate insulin-induced signaling. Endothelium-dependent relaxation was measured in aortic strips. GRK2, β-arrestin 2, and Akt/eNOS signaling pathway proteins and activities were mainly assayed by Western blotting. In ob/ob (vs. control [Lean]) aortas: 1) insulin-induced relaxation was reduced, and this deficit was prevented by GRK2 inhibitor, anti-GRK2 antibody, and an siRNA specifically targeting GRK2. The Lean aorta relaxation response was reduced to the ob/ob level by pretreatment with an siRNA targeting β-arrestin 2. 2) Insulin-stimulated Akt and eNOS phosphorylations were decreased. 3) GRK2 expression in membranes was elevated, and, upon insulin stimulation, this expression was further increased, but β-arrestin 2 was decreased. In ob/ob aortic membranes under insulin stimulation, the phosphorylations of Akt and eNOS were augmented by GRK2 inhibitor. In mouse aorta, GRK2 may be, upon translocation, a key negative regulator of insulin responsiveness and an important regulator of the β-arrestin 2/Akt/eNOS signaling, which is implicated in diabetic endothelial dysfunction.

Searching for self-enrichment in Cygnus OB2

NASA Astrophysics Data System (ADS)

Berlanas, Sara R.; Herrero, Artemio; Comerón, Fernando; Pasquali, Anna; Simón-Díaz, Sergio

2017-11-01

Cygnus OB2 is a rich and relatively close (d~1.4 kpc) OB association in our Galaxy. It represents an ideal testbed for our theories about self-enrichment processes produced by pollution of the interstellar medium by successive generations of massive stars. Comerón & Pasquali (2012, A&A, 543, A101) found a correlation between the age of young stellar groups in Cygnus OB2 and their Galactic longitude. If is associated with a chemical composition gradient, it could support these self-enrichment processes.

Oral delivery of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, synthetic peptide leptin mimetics: Immunofluorescent localization in the mouse hypothalamus.

PubMed

Anderson, Brian M; Jacobson, Lauren; Novakovic, Zachary M; Grasso, Patricia

2017-06-01

This study describes the localization of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, synthetic peptide leptin mimetics, in the hypothalamus of Swiss Webster and C57BL/6J wild-type mice, leptin-deficient ob/ob mice, and leptin-resistant diet-induced obese (DIO) mice. The mice were given [D-Leu-4]-OB3 or MA-[D-Leu-4]-OB3 in 0.3% dodecyl maltoside by oral gavage. Once peak serum concentrations were reached, the mice received a lethal dose of pentobarbital and were subjected to intracardiac perfusion fixation. The brains were excised, post-fixed in paraformaldehyde, and cryo-protected in sucrose. Free-floating frozen coronal sections were cut at 25-µm and processed for imaging by immunofluorescence microscopy. In all four strains of mice, dense staining was concentrated in the area of the median eminence, at the base and/or along the inner wall of the third ventricle, and in the brain parenchyma at the level of the arcuate nucleus. These results indicate that [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 cross the blood-brain barrier and concentrate in an area of the hypothalamus known to regulate energy balance and glucose homeostasis. Most noteworthy is the localization of [D-Leu-4]-OB3 immunoreactivity within the hypothalamus of DIO mice via a conduit that is closed to leptin in this rodent model, and in most cases of human obesity. Together with our previous studies describing the effects of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on energy balance, glucose regulation, and signal transduction pathway activation, these findings are consistent with a central mechanism of action for these synthetic peptide leptin mimetics, and suggest their potential usefulness in the management of leptin-resistant obesity and type 2 diabetes in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Expression of the P2X2 receptor in different classes of ileum myenteric neurons in the female obese ob/ob mouse

PubMed Central

Mizuno, Márcia Sanae; Crisma, Amanda Rabello; Borelli, Primavera; Castelucci, Patricia

2012-01-01

AIM: To examine whether the ob/ob mouse model of obesity is accompanied by enteric nervous system abnormalities such as altered motility. METHODS: The study examined the distribution of the P2X2 receptor (P2X2R) in myenteric neurons of female ob/ob mice. Specifically, we used immunohistochemistry to analyze the co-expression of the P2X2R with neuronal nitric oxide synthase (nNOS), choline acetyltransferase (ChAT), and calretinin (CalR) in neurons of the small intestine myenteric plexus in ob/ob and control female mice. In these sections, we used scanning confocal microscopy to analyze the co-localization of these markers as well as the neuronal density (cm2) and area profile (μm²) of P2X2R-positive neurons. In addition, enteric neurons were labeled using the nicotinamide adenine dinucleotide (NADH) diaphorase method and analyzed with light microscopy as an alternate means by which to analyze neuronal density and area. RESULTS: In the present study, we observed a 29.6% increase in the body weight of the ob/ob animals (OG) compared to the control group (CG). In addition, the average small intestine area was increased by approximately 29.6% in the OG compared to the CG. Immunoreactivity (IR) for the P2X2R, nNOS, ChAT and CalR was detectable in the myenteric plexus, as well as in the smooth muscle, in both groups. This IR appeared to be mainly cytoplasmic and was also associated with the cell membrane of the myenteric plexus neurons, where it outlined the neuronal cell bodies and their processes. P2X2R-IR was observed to co-localize 100% with that for nNOS, ChAT and CalR in neurons of both groups. In the ob/ob group, however, we observed that the neuronal density (neuron/cm2) of P2X2R-IR cells was increased by 62% compared to CG, while that of NOS-IR and ChAT-IR neurons was reduced by 49% and 57%, respectively, compared to control mice. The neuronal density of CalR-IR neurons was not different between the groups. Morphometric studies further demonstrated that the

Effect of Leptin Replacement on PCSK9 in ob/ob Mice and Female Lipodystrophic Patients.

PubMed

Levenson, Amy E; Haas, Mary E; Miao, Ji; Brown, Rebecca J; de Ferranti, Sarah D; Muniyappa, Ranganath; Biddinger, Sudha B

2016-04-01

Leptin treatment has beneficial effects on plasma lipids in patients with lipodystrophy, but the underlying mechanism is unknown. Proprotein convertase subtilisin/kexin type 9 (PCSK9) decreases low-density lipoprotein (LDL) clearance, promotes hypercholesterolemia, and has recently emerged as a novel therapeutic target. To determine the effect of leptin on PCSK9, we treated male and female ob/ob mice with leptin for 4 days via sc osmotic pumps (∼24 μg/d). Leptin reduced body weight and food intake in all mice, but the effects of leptin on plasma PCSK9 and lipids differed markedly between the sexes. In male mice, leptin suppressed PCSK9 but had no effect on plasma triglycerides or cholesterol. In female mice, leptin suppressed plasma triglycerides and cholesterol but had no effect on plasma PCSK9. In parallel, we treated female lipodystrophic patients (8 females, ages 5-23 y) with sc metreleptin injections (∼4.4 mg/d) for 4-6 months. In this case, leptin reduced plasma PCSK9 by 26% (298 ± 109 vs 221 ± 102 ng/mL; n = 8; P = .008), and the change in PCSK9 was correlated with a decrease in LDL cholesterol (r(2) = 0.564, P = .03). In summary, in leptin-deficient ob/ob mice, the effects of leptin on PCSK9 and plasma lipids appeared to be independent of one another and strongly modified by sex. On the other hand, in lipodystrophic females, leptin treatment reduced plasma PCSK9 in parallel with LDL cholesterol.

Effect of Leptin Replacement on PCSK9 in ob/ob Mice and Female Lipodystrophic Patients

PubMed Central

Levenson, Amy E.; Haas, Mary E.; Miao, Ji; Brown, Rebecca J.; de Ferranti, Sarah D.; Muniyappa, Ranganath

2016-01-01

Leptin treatment has beneficial effects on plasma lipids in patients with lipodystrophy, but the underlying mechanism is unknown. Proprotein convertase subtilisin/kexin type 9 (PCSK9) decreases low-density lipoprotein (LDL) clearance, promotes hypercholesterolemia, and has recently emerged as a novel therapeutic target. To determine the effect of leptin on PCSK9, we treated male and female ob/ob mice with leptin for 4 days via sc osmotic pumps (∼24 μg/d). Leptin reduced body weight and food intake in all mice, but the effects of leptin on plasma PCSK9 and lipids differed markedly between the sexes. In male mice, leptin suppressed PCSK9 but had no effect on plasma triglycerides or cholesterol. In female mice, leptin suppressed plasma triglycerides and cholesterol but had no effect on plasma PCSK9. In parallel, we treated female lipodystrophic patients (8 females, ages 5–23 y) with sc metreleptin injections (∼4.4 mg/d) for 4–6 months. In this case, leptin reduced plasma PCSK9 by 26% (298 ± 109 vs 221 ± 102 ng/mL; n = 8; P = .008), and the change in PCSK9 was correlated with a decrease in LDL cholesterol (r2 = 0.564, P = .03). In summary, in leptin-deficient ob/ob mice, the effects of leptin on PCSK9 and plasma lipids appeared to be independent of one another and strongly modified by sex. On the other hand, in lipodystrophic females, leptin treatment reduced plasma PCSK9 in parallel with LDL cholesterol. PMID:26824363

Antisense protein tyrosine phosphatase 1B reverses activation of p38 mitogen-activated protein kinase in liver of ob/ob mice.

PubMed

Gum, Rebecca J; Gaede, Lori L; Heindel, Matthew A; Waring, Jeffrey F; Trevillyan, James M; Zinker, Bradley A; Stark, Margery E; Wilcox, Denise; Jirousek, Michael R; Rondinone, Cristina M; Ulrich, Roger G

2003-06-01

Phosphorylation of stress-activated kinase p38, a MAPK family member, was increased in liver of ob/ob diabetic mice relative to lean littermates. Treatment of ob/ob mice with protein tyrosine phosphatase 1B (PTP1B) antisense oligonucleotides (ASO) reduced phosphorylation of p38 in liver-to below lean littermate levels-and normalized plasma glucose while reducing plasma insulin. Phosphorylation of ERK, but not JNK, was also decreased in ASO-treated mice. PTP1B ASO decreased TNFalpha protein levels and phosphorylation of the transcription factor cAMP response element binding protein (CREB) in liver, both of which can occur through decreased phosphorylation of p38 and both of which have been implicated in insulin resistance or hyperglycemia. Decreased p38 phosphorylation was not directly due to decreased phosphorylation of the kinases that normally phosphorylate p38-MKK3 and MKK6. Additionally, p38 phosphorylation was not enhanced in liver upon insulin stimulation of ASO-treated ob/ob mice (despite increased activation of other signaling molecules) corroborating that p38 is not directly affected via the insulin receptor. Instead, decreased phosphorylation of p38 may be due to increased expression of MAPK phosphatases, particularly the p38/ERK phosphatase PAC1 (phosphatase of activated cells). This study demonstrates that reduction of PTP1B protein using ASO reduces activation of p38 and its substrates TNFalpha and CREB in liver of diabetic mice, which correlates with decreased hyperglycemia and hyperinsulinemia.

The Organic Brain Syndrome (OBS) scale: a systematic review.

PubMed

Björkelund, Karin Björkman; Larsson, Sylvia; Gustafson, Lars; Andersson, Edith

2006-03-01

The Organic Brain Syndrome (OBS) Scale was developed to determine elderly patients' disturbances of awareness and orientation as to time, place and own identity, and assessment of various emotional and behavioural symptoms appearing in delirium, dementia and other organic mental diseases. The aim of the study was to examine the OBS Scale, using the eight criteria and guidelines formulated by the Scientific Advisory Committee of the Medical Outcomes Trust (SAC), and to investigate its relevance and suitability for use in various clinical settings. Systematic search and analysis of papers (30) on the OBS Scale were carried out using the criteria suggested by the SAC. The OBS Scale in many aspects satisfies the requirements suggested by the SAC: conceptual and measurement model, reliability, validity, responsiveness, interpretability, respondent and administrative burden, alternative forms of administration, and cultural and language adaptations, but there is a need for additional evaluation, especially with regard to different forms of reliability, and the translation and adaptation to other languages. The OBS Scale is a sensitive scale which is clinically useful for the description and long-term follow-up of patients showing symptoms of acute confusional state and dementia. Although the OBS Scale has been used in several clinical studies there is need for further evaluation.

Emission of greenhouse gases from geographically isolated wetlands of Western Siberia

NASA Astrophysics Data System (ADS)

Golovatskaya, E.; Dyukarev, E.; Veretennikova, E.

2014-12-01

Wetlands are integral components of landscapes with specific nutrient dynamics and carbon sequestration potentials, which frequently differ, based on hydroperiod and seasonal hydropattern, as well as the constituent concentration of inputs, site-specific storages and vegetation structures. Human modifications have the potential to significantly alter controls on carbon dynamics. This study focused on determining carbon emissions (CO2 and CH4) from geographically isolated peatlands within the Ob-Tom River Interfluve area of Western Siberia affected by water diversion for municipal use by the city of Tomsk, Russia. Two oligotrophic wetlands within the study area were selected for site-specific CO2 studies, the Timiryazevskoe (16 ha) and Kirsanovskoe wetlands (29 ha), both affected by the Tomsk water intake (177 water wells 250 000 m3 water daily). Measurements of СО2 and CH4 emissions from peat surfaces were carried out bi-monthly in growing periods from 2008-2013 in two dominate vegetation zones, pine- shrub-sphagnum phytocenosis (ryam) and sedge-sphagnum fens. СО2 emissions were measured using OPTOGAS-500.4 infrared gas analyzer and dark chamber. Methane emissions were measured using static chamber method. Air samples were collected by syringes and analyzed at gas chromatograph Shimadzu-GC14B. Observations were accompanied by measurement of air temperature and humidity, surface temperature, peat temperature at various depths and the water table level. CО2 emission over the vegetative growing period had clearly pronounced seasonal dynamics with maximum values in the middle of the growing season (mid-July) and minimum values in spring and autumn. The average total flux over the studied period is 123±55 gС/m2 at sedge-sphagnum fen of Kirsanovskoe wetland and 323±66 gС/m2 at fen of Timiryazevskoe wetland. Total СО2 flux for the snow-free period at ryam sites of Timiryazevskoe and Kirsanovskoe wetlands is 238±84 and 260±47 gС/m2 accordingly. Methane

Obs4MIPS: Satellite Observations for Model Evaluation

NASA Astrophysics Data System (ADS)

Ferraro, R.; Waliser, D. E.; Gleckler, P. J.

2017-12-01

This poster will review the current status of the obs4MIPs project, whose purpose is to provide a limited collection of well-established and documented datasets for comparison with Earth system models (https://www.earthsystemcog.org/projects/obs4mips/). These datasets have been reformatted to correspond with the CMIP5 model output requirements, and include technical documentation specifically targeted for their use in model output evaluation. The project holdings now exceed 120 datasets with observations that directly correspond to CMIP5 model output variables, with new additions in response to the CMIP6 experiments. With the growth in climate model output data volume, it is increasing more difficult to bring the model output and the observations together to do evaluations. The positioning of the obs4MIPs datasets within the Earth System Grid Federation (ESGF) allows for the use of currently available and planned online tools within the ESGF to perform analysis using model output and observational datasets without necessarily downloading everything to a local workstation. This past year, obs4MIPs has updated its submission guidelines to closely align with changes in the CMIP6 experiments, and is implementing additional indicators and ancillary data to allow users to more easily determine the efficacy of an obs4MIPs dataset for specific evaluation purposes. This poster will present the new guidelines and indicators, and update the list of current obs4MIPs holdings and their connection to the ESGF evaluation and analysis tools currently available, and being developed for the CMIP6 experiments.

No evidence of disk destruction by OB stars

NASA Astrophysics Data System (ADS)

Richert, Alexander J. W.; Feigelson, Eric

2015-01-01

It has been suggested that the hostile environments observed in massive star forming regions are inhospitable to protoplanetary disks and therefore to the formation of planets. The Orion Proplyds show disk evaporation by extreme ultraviolet (EUV) photons from Theta1 Orionis C (spectral type O6). In this work, we examine the spatial distributions of disk-bearing and non-disk bearing young stellar objects (YSOs) relative to OB stars in 17 massive star forming regions in the MYStIX (Massive Young Star-Forming Complex Study in Infrared and X-ray) survey. Any tendency of disky YSOs, identified by their infrared excess, to avoid OB stars would reveal complete disk destruction.We consider a sample of MYStIX that includes 78 O3-O9 stars, 256 B stars, 5,606 disky YSOs, and 5,794 non-disky YSOs. For each OB star, we compare the cumulative distribution functions of distances to disky and non-disky YSOs. We find no significant avoidance of OB stars by disky YSOs. This result indicates that OB stars are not sufficiently EUV-luminous and long-lived to completely destroy a disk within its ordinary lifetime. We therefore conclude that massive star forming regions are not clearly hostile to the formation of planets.

Systemic anti-TNFalpha treatment restores diabetes-impaired skin repair in ob/ob mice by inactivation of macrophages.

PubMed

Goren, Itamar; Müller, Elke; Schiefelbein, Dana; Christen, Urs; Pfeilschifter, Josef; Mühl, Heiko; Frank, Stefan

2007-09-01

To date, diabetes-associated skin ulcerations represent a therapeutic problem of clinical importance. The insulin-resistant type II diabetic phenotype is functionally connected to obesity in rodent models of metabolic syndrome through the release of inflammatory mediators from adipose tissue. Here, we used the impaired wound-healing process in obese/obese (ob/ob) mice to investigate the impact of obesity-mediated systemic inflammation on cutaneous wound-healing processes. Systemic administration of neutralizing monoclonal antibodies against tumor necrosis factor (TNF)alpha (V1q) or monocyte/macrophage-expressed EGF-like module-containing mucin-like hormone receptor-like (Emr)-1 (F4/80) into wounded ob/ob mice at the end of acute wound inflammation initiated a rapid and complete neo-epidermal coverage of impaired wound tissue in the presence of a persisting diabetic phenotype. Wound closure in antibody-treated mice was paralleled by a marked attenuation of wound inflammation. Remarkably, anti-TNFalpha- and anti-F4/80-treated mice exhibited a strong reduction in circulating monocytic cells and reduced numbers of viable macrophages at the wound site. Our data provide strong evidence that anti-TNFalpha therapy, widely used in chronic inflammatory diseases in humans, might also exert effects by targeting "activated" TNFalpha-expressing macrophage subsets, and that inactivation or depletion of misbehaving macrophages from impaired wounds might be a novel therapeutic clue to improve healing of skin ulcers.

A Holocene molluscan succession from floodplain sediments of the upper Lena River (Lake Baikal region), Siberia

NASA Astrophysics Data System (ADS)

White, Dustin; Preece, Richard C.; Shchetnikov, Alexander A.; Parfitt, Simon A.; Dlussky, Konstantin G.

2008-05-01

Floodplain sediments of the upper Lena River near Basovo in south-central Siberia have yielded the most detailed Holocene molluscan succession yet reported from the entire eastern Palaearctic. Over 72,500 shells from at least 28 species of terrestrial and 23 species of freshwater mollusc have been recovered, an abundance and diversity far higher than previously reported from the region. The molluscan assemblages are dominated by land snails, especially members of the genus Vallonia, represented by five species including Vallonia tenuilabris and two poorly known species Vallonia kamtschatica and Vallonia cf. chinensis. Other noteworthy species recovered include Gastrocopta theeli, Carychium pessimum, Vertigo extima (southernmost record), Vertigo microsphaera and the first Asian records of three other taxa ( Vertigo geyeri, Vertigo genesii and Vertigo parcedentata). Illustrations are provided for the critical species, since opinions differ about the status of various taxa and the correct names that should be used. The molluscan assemblages show clear successional trends during the early to mid-Holocene, reflecting episodes of dryness/wetness on the floodplain. Drier conditions at ca 6350 14C yr BP coincide with major changes in the archaeological record seen at other sites in the region but it remains unclear whether the two are linked. A prominent charcoal-rich horizon dated to ca 2800 14C yr BP marks a burning event in the catchment, which resulted in a two-fold increase in sediment accumulation rate. Remains of small mammals occurred throughout the sequence including a tooth of Microtus cf. maximowiczii, possibly the first occurrence of Ungar vole west of Lake Baikal. The faunal analyses have been integrated with a detailed pedological study of the sedimentary profile and a chronology was obtained by means of 12 AMS radiocarbon dates. This study provides the first detailed palaeoecological information relating to Holocene molluscan assemblages from the Cis

LXR activation by GW3965 alters fat tissue distribution and adipose tissue inflammation in ob/ob female mice[S

PubMed Central

Archer, Amena; Stolarczyk, Émilie; Doria, Maria Luisa; Helguero, Luisa; Domingues, Rosário; Howard, Jane K.; Mode, Agneta; Korach-André, Marion; Gustafsson, Jan-Åke

2013-01-01

To investigate the role of liver X receptor (LXR) in adipose tissue metabolism during obesity, ob/ob mice were treated for 5 weeks with the synthetic LXR agonist GW3965. MRI analysis revealed that pharmacological activation of LXR modified fat distribution by decreasing visceral (VS) fat and inversely increasing subcutaneous (SC) fat storage without affecting whole body fat content. This was concordant with opposite regulation by GW3965 of the lipolytic markers hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) in the two fat depots; moreover, the expression of genes involved in lipogenesis was significantly induced in SC fat. Lipidomic analysis suggested that changes in lipid composition in response to GW3965 also varied between VS and SC fat. In both depots, the observed alteration in lipid composition indicated an overall change toward less lipotoxic lipids. Flow cytometry analysis showed decreased immune cell infiltration in adipose tissue of ob/ob mice in response to GW3965 treatment, which in VS fat mainly affected the macrophage population and in SC fat the lymphocyte population. In line with this, the expression and secretion of proinflammatory markers was decreased in both fat deposits with GW3965 treatment. PMID:23446231

Mining the Obscured OB Star Population in Carina

NASA Astrophysics Data System (ADS)

Smith, Michael

2016-04-01

Massive OB stars are very influential objects in the ecology of galaxies like our own. Current catalogues of Galactic OB stars are heavily biased towards bright (g < 13) objects, only typically including fainter objects when found in prominent star clusters (Garmany et al., 1982; Reed, 2003; Maíz-Apellaniz et al., 2004). Exploitation of the VST Photometric Hα Survey (VPHAS+) allows us to build a robust catalogue of photometrically-selected OB stars across the entire Southern Galactic plane, both within clusters and in the field, down to ∼20th magnitude in g. For the first time, a complete accounting of the OB star runaway phenomenon becomes possible. Along with making the primary selection using VPHAS+ colours, I have performed Markov-Chain Monte Carlo fitting of the spectral energy distributions of the selected stars by combining VPHAS+ u, g, r, i with published J, H, K photometry. This gives rough constraints on effective temperature and distance, whilst delivering much more precise reddening parameters A0 and RV - allowing us to build a much richer picture of how extinction and extinction laws vary across the Galactic Plane. My thesis begins with a description of the method of photometric selection of OB star candidates and its validation across a 2 square degree field including the well-known young massive star cluster Westerlund 2 (Mohr-Smith et al., 2015). Following on from this I present spectroscopy with AAOmega of 283 candidates identified by our method, which confirms that ∼94% of the sample are the expected O and early B stars. I then develop this method further and apply it to a Galactic Plane strip of 42 square-degrees that runs from the Carina Arm tangent region to the much studied massive cluster in NGC 3603. A new aspect I attend to in this expansion of method is tightening up the uniform photometric calibration of the data, paying particular attention to the always-challenging u band. This leads to a new and reliable catalogue of 5915 OB

[D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, small molecule synthetic peptide leptin mimetics, improve glycemic control in diet-induced obese (DIO) mice.

PubMed

Wang, Anke; Anderson, Brian M; Novakovic, Zachary M; Grasso, Patricia

2018-03-01

We have previously shown that following oral delivery in dodecyl maltoside (DDM), [D-Leu-4]-OB3 and its myristic acid conjugate, MA-[D-Leu-4]-OB3, improved energy balance and glucose homeostasis in genetically obese/diabetic mouse models. More recently, we have provided immunohistochemical evidence indicating that these synthetic peptide leptin mimetics cross the blood-brain barrier and concentrate in the area of the arcuate nucleus of the hypothalamus in normal C57BL/6J and Swiss Webster mice, in genetically obese ob/ob mice, and in diet-induced obese (DIO) mice. In the present study, we describe the effects of oral delivery of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on glycemic control in diet-induced (DIO) mice, a non-genetic rodent model of obesity and its associated insulin resistance, which more closely recapitulates common obesity and diabetes in humans. Male C57BL/6J and DIO mice, 17, 20, and 28 weeks of age, were maintained on a low-fat or high-fat diet and given vehicle (DDM) alone or [D-Leu-4]-OB3 or MA-[D-Leu-4]-OB3 in DDM by oral gavage for 12 or 14 days. Body weight gain, food and water intake, fasting blood glucose, oral glucose tolerance, and serum insulin levels were measured. Our data indicate that (1) [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 restore glucose tolerance in male DIO mice maintained on a high-fat diet to levels comparable to those of non-obese C57BL/6J wild-type mice of the same age and sex maintained on a low-fat diet; and (2) the influence of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on glycemic control appears to be independent of their effects on energy balance. These results suggest that [D-Leu-4]-OB3 and/or MA-[D-Leu-4]-OB3 may have application to the management of the majority of cases of common obesity in humans, a state characterized at least in part, by leptin resistance resulting from a defect in leptin transport across the blood-brain barrier. They further suggest that these small molecule synthetic peptide leptin mimetics, through their

Hydrological and climate changes in southeast Siberia over the last 33 kyr

NASA Astrophysics Data System (ADS)

Katsuta, Nagayoshi; Ikeda, Hisashi; Shibata, Kenji; Saito-Kokubu, Yoko; Murakami, Takuma; Tani, Yukinori; Takano, Masao; Nakamura, Toshio; Tanaka, Atsushi; Naito, Sayuri; Ochiai, Shinya; Shichi, Koji; Kawakami, Shin-ichi; Kawai, Takayoshi

2018-05-01

Paleoenvironmental and paleoclimate changes in intracontinental Siberia were reconstructed by continuous, high-resolution records (biogenic silica, U, total organic carbon and N, total S, and grain size) from a sediment core retrieved from the Buguldeika Saddle, Lake Baikal, dating back to the last 33 cal. ka BP. The Holocene climate was wet relative to the last glacial period. The climate became gradually warm and wet from the early to middle Holocene, followed by a shift at ca. 6.5 cal. ka BP toward warm and dry, possibly because of evapotranspiration. This suggests that the climate system transition from the glacial to interglacial state occurred at that time. In the last glacial, the deposition of carbonate mud from the Primorsky Range was associated with Heinrich events (H3 and H1) and the Selenga River inflow during the Last Glacial Maximum was caused by meltwater of mountain glaciers in the Khamar-Daban Range. The anoxic bottom-water during the Allerød-Younger Dryas was probably a result of weakened ventilation associated with reduced Selenga River inflow and microbial decomposition of organic matters originating from moderate input of nutrients from the Primorsky Range. The rapid decline in precipitation during the early Holocene may have been a response to the 8.2 ka cooling event.

Emodin, an 11β-hydroxysteroid dehydrogenase type 1 inhibitor, regulates adipocyte function in vitro and exerts anti-diabetic effect in ob/ob mice

PubMed Central

Wang, Yue-jing; Huang, Su-ling; Feng, Ying; Ning, Meng-meng; Leng, Ying

2012-01-01

Aim: Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a potent and selective inhibitor of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) with the ability to ameliorate metabolic disorders in diet-induced obese mice. In the present study, we investigated the effects of emodin on adipocyte function and the underlying mechanisms in vitro, and its anti-diabetic effects in ob/ob mice. Methods: 3T3-L1 adipocytes were used for in vitro studies. 11β-HSD1A activity was evaluated with a scintillation proximity assay. The adipogenesis, glucose uptake, lipolysis and adiponectin secretion were investigated in 3T3-L1 adipocytes treated with emodin in the presence of active (corticosterone) or inactive glucocorticoid (11-dehydrocorticosterone). For in vivo studies, ob/ob mice were administered emodin (25 and 50 mg·kg−1·d−1, ip) for 26 d. On the last day of administration, the serum was collected and the mesenteric and perirenal fat were dissected for analyses. Results: Emodin inhibited the 11β-HSD1 activity in 3T3-L1 adipocytes in concentration- and time-dependent manners (the IC50 values were 7.237 and 4.204 μmol/L, respectively, after 1 and 24 h treatment. In 3T3-L1 adipocytes, emodin (30 μmol/L) suppressed 11-dehydrocorticosterone-induced adipogenesis without affecting corticosterone-induced adipogenesis; emodin (3 μmol/L) reduced 11-dehydrocorticosterone-stimulated lipolysis, but had no effect on corticosterone-induced lipolysis. Moreover, emodin (3 μmol/L) partly reversed the impaired insulin-stimulated glucose uptake and adiponectin secretion induced by 11-dehydrocorticosterone but not those induced by corticosterone. In ob/ob mice, long-term emodin administration decreased 11β-HSD1 activity in mesenteric adipose tissues, lowered non-fasting and fasting blood glucose levels, and improved glucose tolerance. Conclusion: Emodin improves the inactive glucocorticoid-induced adipose tissue dysfunction by selective inhibition on 11β-HSD1 in adipocyte in vitro

Recent Seismic Experiments of OBS in the South China Sea

NASA Astrophysics Data System (ADS)

Ruan, A.; Li, J.; Wu, Z.

2012-12-01

Since 2006 some research institutions of China have carried out some important seismic experiments by using ocean bottom seismometer(OBS) in the South China Sea (SCS) and obtained many concrete progresses in modeling the crustal structure of SCS and also in understanding of its formation and evolution as well. In 2006 three wide-angle profiles were completed in the northern margin, named OBS2006-1 across the northwestern sub-basin, OBS2006-2 parallel to the sea basin boundary and OBS2006-3 across the Dongsha Rise and Chaoshan Depression respectively. In 2010 two wide- angle profiles were completed, named OBS2010-1 and OBS 2010-2 both perpendicular to the northern off-shore faulting system. During 2009-2011 four wide-angle profiles were completed in the southern margin, named OBS973-1 from southern margin to the southwestern sub-basin, OBS973-2 from Liyue Bank to the southwestern sub-basin and OBS973-3 from Xisha to the southwestern sub-basin, OBS2011-2 from Xisha to Hainan Island respectively. In 2011 two 3D seismic array of OBS were completed in the Zhongnan-Changlong sea mount chain and Huangyan-Zhenbei sea mount chain respectively. Here we present some primary but important results as follows. (1) The velocity model of OBS2006-1 indicates that the crust under the continental slope decreases from 21km to 11km, and to 7.7km in the northwestern sub-basin with Moho depth ascends from 21km to 11km. The tectonic geometry and velocity structure of the northwestern sub-basin and its margins on both sides shows symmetrical and conjugate and indicates pure shear mode of continental margin rifting mechanism. (2) The velocity model of OBS2006-3 reveals remarkable thickness with maximum 8 km of the Mesozoic sediment in Chaoshan Depression in which velocity increases downward from 4.4 km/s at top to 5.3 km/s at the bottom. The buried depth of Moho decreases from 24-25 km under Dongsha Rise to 17 km in the lower slope and an obviously velocity abnormal is detected in the upper

ObsPy: A Python Toolbox for Seismology

NASA Astrophysics Data System (ADS)

Wassermann, J. M.; Krischer, L.; Megies, T.; Barsch, R.; Beyreuther, M.

2013-12-01

Python combines the power of a full-blown programming language with the flexibility and accessibility of an interactive scripting language. Its extensive standard library and large variety of freely available high quality scientific modules cover most needs in developing scientific processing workflows. ObsPy is a community-driven, open-source project extending Python's capabilities to fit the specific needs that arise when working with seismological data. It a) comes with a continuously growing signal processing toolbox that covers most tasks common in seismological analysis, b) provides read and write support for many common waveform, station and event metadata formats and c) enables access to various data centers, webservices and databases to retrieve waveform data and station/event metadata. In combination with mature and free Python packages like NumPy, SciPy, Matplotlib, IPython, Pandas, lxml, and PyQt, ObsPy makes it possible to develop complete workflows in Python, ranging from reading locally stored data or requesting data from one or more different data centers via signal analysis and data processing to visualization in GUI and web applications, output of modified/derived data and the creation of publication-quality figures. All functionality is extensively documented and the ObsPy Tutorial and Gallery give a good impression of the wide range of possible use cases. ObsPy is tested and running on Linux, OS X and Windows and comes with installation routines for these systems. ObsPy is developed in a test-driven approach and is available under the LGPLv3 open source licence. Users are welcome to request help, report bugs, propose enhancements or contribute code via either the user mailing list or the project page on GitHub.

Optical properties and bioavailability of dissolved organic matter along a flow-path continuum from soil pore waters to the Kolyma River mainstem, East Siberia

NASA Astrophysics Data System (ADS)

Frey, Karen E.; Sobczak, William V.; Mann, Paul J.; Holmes, Robert M.

2016-04-01

The Kolyma River in northeast Siberia is among the six largest Arctic rivers and drains a region underlain by vast deposits of Holocene-aged peat and Pleistocene-aged loess known as yedoma, most of which is currently stored in ice-rich permafrost throughout the region. These peat and yedoma deposits are important sources of dissolved organic matter (DOM) to inland waters that in turn play a significant role in the transport and ultimate remineralization of organic carbon to CO2 and CH4 along the terrestrial flow-path continuum. The turnover and fate of terrigenous DOM during offshore transport largely depends upon the composition and amount of carbon released to inland and coastal waters. Here, we measured the ultraviolet-visible optical properties of chromophoric DOM (CDOM) from a geographically extensive collection of waters spanning soil pore waters, streams, rivers, and the Kolyma River mainstem throughout a ˜ 250 km transect of the northern Kolyma River basin. During the period of study, CDOM absorption coefficients were found to be robust proxies for the concentration of DOM, whereas additional CDOM parameters such as spectral slopes (S) were found to be useful indicators of DOM quality along the flow path. In particular, the spectral slope ratio (SR) of CDOM demonstrated statistically significant differences between all four water types and tracked changes in the concentration of bioavailable DOC, suggesting that this parameter may be suitable for clearly discriminating shifts in organic matter characteristics among water types along the full flow-path continuum across this landscape. However, despite our observations of downstream shifts in DOM composition, we found a relatively constant proportion of DOC that was bioavailable ( ˜ 3-6 % of total DOC) regardless of relative water residence time along the flow path. This may be a consequence of two potential scenarios allowing for continual processing of organic material within the system, namely (a

Multilingual Education in South Siberia: National Schools in the Republics of Altai and Tyva

ERIC Educational Resources Information Center

Chevalier, Joan F.

2012-01-01

Subtractive bilingualism is widespread throughout Siberia, with indigenous youth often more proficient in Russian than in their non-Russian local languages. Siberia's national schools, which are secondary schools offering instruction in local languages of Russia, provide critical institutional support for minority languages. The goal of this…

African Swine Fever Virus, Siberia, Russia, 2017.

PubMed

Kolbasov, Denis; Titov, Ilya; Tsybanov, Sodnom; Gogin, Andrey; Malogolovkin, Alexander

2018-04-01

African swine fever (ASF) is arguably the most dangerous and emerging swine disease worldwide. ASF is a serious problem for the swine industry. The first case of ASF in Russia was reported in 2007. We report an outbreak of ASF in Siberia, Russia, in 2017.

Cygnus OB2 DANCe: A high-precision proper motion study of the Cygnus OB2 association

NASA Astrophysics Data System (ADS)

Wright, Nicholas J.; Bouy, Herve; Drew, Janet E.; Sarro, Luis Manuel; Bertin, Emmanuel; Cuillandre, Jean-Charles; Barrado, David

2016-08-01

We present a high-precision proper motion study of 873 X-ray and spectroscopically selected stars in the massive OB association Cygnus OB2 as part of the DANCe project. These were calculated from images spanning a 15 yr baseline and have typical precisions <1 mas yr-1. We calculate the velocity dispersion in the two axes to be σ _α (c) = 13.0^{+0.8}_{-0.7} and σ _δ (c) = 9.1^{+0.5}_{-0.5} km s-1, using a two-component, two-dimensional model that takes into account the uncertainties on the measurements. This gives a three-dimensional velocity dispersion of σ3D = 17.8 ± 0.6 km s-1 implying a virial mass significantly larger than the observed stellar mass, confirming that the association is gravitationally unbound. The association appears to be dynamically unevolved, as evidenced by considerable kinematic substructure, non-isotropic velocity dispersions and a lack of energy equipartition. The proper motions show no evidence for a global expansion pattern, with approximately the same amount of kinetic energy in expansion as there is in contraction, which argues against the association being an expanded star cluster disrupted by process such as residual gas expulsion or tidal heating. The kinematic substructures, which appear to be close to virial equilibrium and have typical masses of 40-400 M⊙, also do not appear to have been affected by the expulsion of the residual gas. We conclude that Cyg OB2 was most likely born highly substructured and globally unbound, with the individual subgroups born in (or close to) virial equilibrium, and that the OB association has not experienced significant dynamical evolution since then.

Isolation of dissolved organic matter from permafrost soil and freshwater environments of the Kolyma River basin, east Siberia, for high resolution structural analysis

NASA Astrophysics Data System (ADS)

Dubinenkov, I. V.; Perminova, I. V.; Bulygina, E. B.; Holmes, R. M.; Davydov, S.; Mann, P. J.; Vonk, J.; Zimov, S. A.

2010-12-01

, we used from 20 to 40 liters of water sample per one cartridge depending on DOC concentration in water. To isolate DOM from permafrost soil samples, the water extract was first prepared and used for further isolation of DOM. The fluorescence measurements of the samples before and after discharge through the cartridge showed a lack of specific sorption. As an outcome of the undertaken studies a set of 19 samples from the different environments of the Kolyma River basin was collected including samples from the modern soil, transitory layer, permafrost, floodplain streams, permafrost melting streams, the Kolyma River mainstream and the Arctic Ocean. Each sample is represented by 50mg DOM, which enables its further analysis using Fourier transform ion cyclotron resonance mass spectrometry and 1H NMR spectroscopy. This study is part of the Polaris Project, an NSF-funded undergraduate field program based out of the Northeast Science Station in Cherskiy, Northeast Siberia (www.thepolarisproject.org).

The Puppis region and the last crusade for faint OB stars

NASA Astrophysics Data System (ADS)

Orsatti, Ana M.

1992-08-01

UBV photoelectric and photographic measurements of OB stars from a list of 397 OB stars and 5 early-type supergiants and from the Luminous Stars Survey are presented. The galactic distribution of the OB stars in the region shows concentrations around the open clusters Ruprecht 44 and Ruprecht 55, and the presence of an important grouping of young stars located far below the plane. The distribution in latitude shows that young stars in the region are not restricted to a thin sheet around the plane but are spread over negative latitudes reaching at least b = -5 deg. In longitude, the OB distribution exhibits a concentration of Ob stars in the interval 244-251 deg; this is argued to be due to the presence of the local arm extension.

Wind collisions in three massive stars of Cygnus OB2

NASA Astrophysics Data System (ADS)

Cazorla, Constantin; Nazé, Yaël; Rauw, Gregor

2014-01-01

Aims: We wish to study the origin of the X-ray emission of three massive stars in the Cyg OB2 association: Cyg OB2 #5, Cyg OB2 #8A, and Cyg OB2 #12. Methods: To this aim, dedicated X-ray observations from XMM-Newton and Swift are used, as well as archival ROSAT and Suzaku data. Results: Our results on Cyg OB2 #8A improve the phase coverage of the orbit and confirm previous studies: the signature of a wind-wind collision is conspicuous. In addition, signatures of a wind-wind collision are also detected in Cyg OB2 #5, but the X-ray emission appears to be associated with the collision between the inner binary and the tertiary component orbiting it with a 6.7 yr period, without a putative collision inside the binary. The X-ray properties strongly constrain the orbital parameters, notably allowing us to discard some proposed orbital solutions. To improve the knowledge of the orbit, we revisit the light curves and radial velocity of the inner binary, looking for reflex motion induced by the third star. Finally, the X-ray emission of Cyg OB2 #12 is also analyzed. It shows a marked decrease in recent years, compatible with either a wind-wind collision in a wide binary or the aftermath of a recent eruption. Based on observations collected at the Observatoire de Haute Provence (OHP) as well as with Swift and XMM-Newton.Tables 1-3 and 5 are available in electronic form at http://www.aanda.org

Impaired contractile responses and altered expression and phosphorylation of Ca2+ sensitization proteins in gastric antrum smooth muscles from ob/ob mice

PubMed Central

Bhetwal, Bhupal P.; An, Changlong; Baker, Salah A.; Lyon, Kristin L.

2013-01-01

Diabetic gastroparesis is a common complication of diabetes, adversely affecting quality of life with symptoms of abdominal discomfort, nausea, and vomiting. The pathogenesis of this complex disorder is not well understood, involving abnormalities in the extrinsic and enteric nervous systems, interstitial cells of Cajal (ICCs), smooth muscles and immune cells. The ob/ob mouse model of obesity and diabetes develops delayed gastric emptying, providing an animal model for investigating how gastric smooth muscle dysfunction contributes to the pathophysiology of diabetic gastroparesis. Although ROCK2, MYPT1, and CPI-17 activities are reduced in intestinal motility disorders, their functioning has not been investigated in diabetic gastroparesis. We hypothesized that reduced expression and phosphorylation of the myosin light chain phosphatase (MLCP) inhibitory proteins MYPT1 and CPI-17 in ob/ob gastric antrum smooth muscles could contribute to the impaired antrum smooth muscle function of diabetic gastroparesis. Spontaneous and carbachol- and high K+-evoked contractions of gastric antrum smooth muscles from 7 to 12 week old male ob/ob mice were reduced compared to age- and strain-matched controls. There were no differences in spontaneous and agonist-evoked intracellular Ca2+ transients and myosin light chain kinase expression. The F-actin:G-actin ratios were similar. Rho kinase 2 (ROCK2) expression was decreased at both ages. Basal and agonist-evoked MYPT1 and myosin light chain 20 phosphorylation, but not CPI-17 phosphorylation, was reduced compared to age-matched controls. These findings suggest that reduced MLCP inhibition due to decreased ROCK2 phosphorylation of MYPT1 in gastric antrum smooth muscles contributes to the antral dysmotility of diabetic gastroparesis. PMID:23576331

Hog millet (Panicum miliaceum L.)-supplemented diet ameliorates hyperlipidemia and hepatic lipid accumulation in C57BL/6J-ob/ob mice

PubMed Central

Park, Mi-Young; Jang, Hwan-Hee; Kim, Jung Bong; Yoon, Hyun Nye; Lee, Jin-Young; Lee, Young-Min; Kim, Jae-Hyun

2011-01-01

Dietary intake of whole grains reduces the incidence of chronic diseases such as obesity, diabetes, cardiovascular disease, and cancer. In an earlier study, we showed that Panicum miliaceum L. extract (PME) exhibited the highest anti-lipogenic activity in 3T3-L1 cells among extracts of nine different cereal grains tested. In this study, we hypothesized that PME in the diet would lead to weight loss and augmentation of hyperlipidemia by regulating fatty acid metabolism. PME was fed to ob/ob mice at 0%, 0.5%, or 1% (w/w) for 4 weeks. After the experimental period, body weight changes, blood serum and lipid profiles, hepatic fatty acid metabolism-related gene expression, and white adipose tissue (WAT) fatty acid composition were determined. We found that the 1% PME diet, but not the 0.5%, effectively decreased body weight, liver weight, and blood triglyceride and total cholesterol levels (P < 0.05) compared to obese ob/ob mice on a normal diet. Hepatic lipogenic-related gene (PPARα, L-FABP, FAS, and SCD1) expression decreased, whereas lipolysis-related gene (CPT1) expression increased in animals fed the 1% PME diet (P < 0.05). Long chain fatty acid content and the ratio of C18:1/C18:0 fatty acids decreased significantly in adipose tissue of animals fed the 1% PME diet (P < 0.05). Serum inflammatory mediators also decreased significantly in animals fed the 1% PME diet compared to those of the ob/ob control group (P < 0.05). These results suggest that PME is useful in the chemoprevention or treatment of obesity and obesity-related disorders. PMID:22259675

Frankfurt Medical Department Activity (FMEDDAC) OB/GYN Clinic Study

DTIC Science & Technology

1993-08-01

ideas took hold and flourished in post-World War II Japan ( Arikan , 1990). The Japanese institutionalized the following chain FMEDDAC OB-GYN 8 reaction...be required for most organizations. FMEDDAC OB-GYN 69 References Arikan , V.L. (1991). Total quality management - Applications to nursing service

Woolly rhino discovery in the lower Kolyma River

NASA Astrophysics Data System (ADS)

Boeskorov, Gennady G.; Lazarev, Peter A.; Sher, Andrei V.; Davydov, Sergei P.; Bakulina, Nadezhda T.; Shchelchkova, Marina V.; Binladen, Jonas; Willerslev, Eske; Buigues, Bernard; Tikhonov, Alexey N.

2011-08-01

A nearly complete frozen mummy of a woolly rhinoceros ( Coelodonta antiquitatis Blum., 1799) was discovered in a gold mine on the lower reaches of the Kolyma River, north-eastern Siberia. This is the first find of the whole body of woolly rhino in permafrost. A large part of the mummified body was preserved, including the left part of the body, covered by skin, including skin of the head and ear, fore and hind legs. The skull with 2 horns and the lower jaw were also preserved. Most of the internal organs were lost, except the intestines, stomach, and their contents. A rib fragment from this individual was dated by AMS-radiocarbon method to 39,140 ± 390 years BP (OxA-18755). Spore and pollen analyses of the stomach contents indicate that grasses and sagebrushes formed the main part of the diet of C. antiquitatis in this region of Arctic Siberia.

A CATALOG OF NEW SPECTROSCOPICALLY CONFIRMED MASSIVE OB STARS IN CARINA

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

Alexander, Michael J.; Hanes, Richard J.; McSwain, M. Virginia

2016-12-01

The Carina star-forming region is one of the largest in the Galaxy, and its massive star population is still being unveiled. The large number of stars combined with high, and highly variable, interstellar extinction makes it inherently difficult to find OB stars in this type of young region. We present the results of a spectroscopic campaign to study the massive star population of the Carina Nebula, with the primary goal to confirm or reject previously identified Carina OB star candidates. A total of 141 known O- and B-type stars and 94 candidates were observed, of which 73 candidates had highmore » enough signal-to-noise ratio to classify. We find 23 new OB stars within the Carina Nebula, a 32% confirmation rate. One of the new OB stars has blended spectra and is suspected to be a double-lined spectroscopic binary (SB2). We also reclassify the spectral types of the known OB stars and discover nine new SB2s among this population. Finally, we discuss the spatial distribution of these new OB stars relative to known structures in the Carina Nebula.« less

Ablation of ghrelin O-acyltransferase does not improve glucose intolerance or body adiposity in mice on a leptin-deficient ob/ob background.

PubMed

Kirchner, Henriette; Heppner, Kristy M; Holland, Jenna; Kabra, Dhiraj; Tschöp, Matthias H; Pfluger, Paul T

2013-01-01

Type 2 Diabetes is a global health burden and based on current estimates will become an even larger problem in the future. Developing new strategies to prevent and treat diabetes is a scientific challenge of high priority. The stomach hormone ghrelin has been associated with playing a role in the regulation of glucose homeostasis. However, its precise mechanism and impact on whole glucose metabolism remains to be elucidated. This study aims to clarify the role of the two ghrelin isoforms acyl- and desacyl ghrelin in regulating glucose homeostasis. Therefore ghrelin activating enzyme Ghrelin-O-acyltransferase (GOAT) was ablated in leptin-deficient ob/ob mice to study whether specific acyl ghrelin deficiency or desacyl ghrelin abundance modifies glucose tolerance on a massively obese background. As targeted deletion of acyl ghrelin does not improve glucose homeostasis in our GOAT-ob/ob mouse model we conclude that neither acyl ghrelin nor the increased ratio of desacyl/acyl ghrelin is crucial for controlling glucose homeostasis in the here presented model of massive obesity induced by leptin deficiency.

Arctigenin, a natural compound, activates AMP-activated protein kinase via inhibition of mitochondria complex I and ameliorates metabolic disorders in ob/ob mice.

PubMed

Huang, S-L; Yu, R-T; Gong, J; Feng, Y; Dai, Y-L; Hu, F; Hu, Y-H; Tao, Y-D; Leng, Y

2012-05-01

Arctigenin is a natural compound that had never been previously demonstrated to have a glucose-lowering effect. Here it was found to activate AMP-activated protein kinase (AMPK), and the mechanism by which this occurred, as well as the effects on glucose and lipid metabolism were investigated. 2-Deoxyglucose uptake and AMPK phosphorylation were examined in L6 myotubes and isolated skeletal muscle. Gluconeogenesis and lipid synthesis were evaluated in rat primary hepatocytes. The acute and chronic effects of arctigenin on metabolic abnormalities were observed in C57BL/6J and ob/ob mice. Changes in mitochondrial membrane potential were measured using the J-aggregate-forming dye, JC-1. Analysis of respiration of L6 myotubes or isolated mitochondria was conducted in a channel oxygen system. Arctigenin increased AMPK phosphorylation and stimulated glucose uptake in L6 myotubes and isolated skeletal muscles. In primary hepatocytes, it decreased gluconeogenesis and lipid synthesis. The enhancement of glucose uptake and suppression of hepatic gluconeogenesis and lipid synthesis by arctigenin were prevented by blockade of AMPK activation. The respiration of L6 myotubes or isolated mitochondria was inhibited by arctigenin with a specific effect on respiratory complex I. A single oral dose of arctigenin reduced gluconeogenesis in C57BL/6J mice. Chronic oral administration of arctigenin lowered blood glucose and improved lipid metabolism in ob/ob mice. This study demonstrates a new role for arctigenin as a potent indirect activator of AMPK via inhibition of respiratory complex I, with beneficial effects on metabolic disorders in ob/ob mice. This highlights the potential value of arctigenin as a possible treatment of type 2 diabetes.

Additional red and reddened stars in Cyg OB2 association

NASA Technical Reports Server (NTRS)

Parthasarathy, M.; Jain, S. K.

1989-01-01

Several new red and reddened stars are detected in the most heavily reddened associations Cyg OB2. About 47 IRAS sources are detected in Cyg OB2. Their flux distributions, and colors, suggest that they are young stellar objects embedded in dust envelopes or disks (some of them may be proto stars) and are most likely members of the Cyg OB2 association. The large values of the flux ratio L sub IR/L sub VIS suggests that the central objects are obscured because of very large extinction.

Using New Remotely-sensed Biomass To Estimate Co2 Fluxes Over Siberia

NASA Astrophysics Data System (ADS)

Lafont, S.; Kergoat, L.; Dedieu, G.; Le Toan, T.

Two european programs recently focused on Siberia. The first one, Eurosiberian Car- bonflux was a faisability study for an observation system of the regional CO2 fluxes. The second one, SIBERIA was a big effort to develop and validate a biomass map on Siberia using radar data from satelltes (J-ERS, ERS). Here, we extend the simula- tion of NPP performed for the first program by using the biomass data of the second program. The TURC model, used here, is a global NPP model, based on light use efficiency, where photosynthetic assimilation is driven by satellite vegetation index, and au- totrophic respiration is driven by biomass. In this study, we will present a n´ zoom z on siberian region. The TURC model was run with a fine resolution (few kilometers) and a daily time step. We will discuss the impact of a new biomass dataset description on Net Primary Pro- ductivity (NPP) and CO2 fluxes estimation.

Evaluation of Seismic Risk of Siberia Territory

NASA Astrophysics Data System (ADS)

Seleznev, V. S.; Soloviev, V. M.; Emanov, A. F.

The outcomes of modern geophysical researches of the Geophysical Survey SB RAS, directed on study of geodynamic situation in large industrial and civil centers on the territory of Siberia with the purpose of an evaluation of seismic risk of territories and prediction of origin of extreme situations of natural and man-caused character, are pre- sented in the paper. First of all it concerns the testing and updating of a geoinformation system developed by Russian Emergency Ministry designed for calculations regarding the seismic hazard and response to distructive earthquakes. The GIS database contains the catalogues of earthquakes and faults, seismic zonation maps, vectorized city maps, information on industrial and housing fund, data on character of building and popula- tion in inhabited places etc. The geoinformation system allows to solve on a basis of probabilistic approaches the following problems: - estimating the earthquake impact, required forces, facilities and supplies for life-support of injured population; - deter- mining the consequences of failures on chemical and explosion-dangerous objects; - optimization problems on assurance technology of conduct of salvage operations. Using this computer program, the maps of earthquake risk have been constructed for several seismically dangerous regions of Siberia. These maps display the data on the probable amount of injured people and relative economic damage from an earthquake, which can occur in various sites of the territory according to the map of seismic zona- tion. The obtained maps have allowed determining places where the detailed seismo- logical observations should be arranged. Along with it on the territory of Siberia the wide-ranging investigations with use of new methods of evaluation of physical state of industrial and civil establishments (buildings and structures, hydroelectric power stations, bridges, dams, etc.), high-performance detailed electromagnetic researches of ground conditions of city

The over-expression of miR-200a in the hypothalamus of ob/ob mice is linked to leptin and insulin signaling impairment.

PubMed

Crépin, Delphine; Benomar, Yacir; Riffault, Laure; Amine, Hamza; Gertler, Arieh; Taouis, Mohammed

2014-03-25

Early in life, leptin plays a crucial role in hypothalamic neural organization. Leptin, most likely, controls neural gene expression conferring then specific phenotype regarding energy homeostasis. MicroRNAs are new regulators for several physiological functions, including the regulation of metabolism. However, the impact of leptin on hypothalamic microRNA patterns remains unknown. Here, we demonstrate that miR-200a, miR-200b and miR-429 are up-regulated in the hypothalamus of genetically obese and leptin deficient ob/ob mice. Leptin treatment down-regulates these miRNAs in ob/ob hypothalamus. The hypothalamic silencing of miR-200a increased the expression level of leptin receptor and insulin receptor substrate 2, reduced body weight gain, and restored liver insulin responsiveness. In addition, the overexpression of pre-miR-200a in a human neuroblastoma cell line impaired insulin and leptin signaling. These findings link the alteration of leptin and insulin signaling to the up-regulation of hypothalamic miR-200a which could be a new target for treatment of obesity. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Phytoremediation of Excavation in Eastern Siberia

NASA Astrophysics Data System (ADS)

Timofeeva, S. S.; Zhmurova, T. M.

2017-04-01

The paper deals with prospects and applicability of phytoremediation technology in the conditions of Eastern Siberia as applied to gypsum stone extraction of Zalarinsky deposit in Irkutsk region. It analyses dust intensity for different technological processes of the deposit and evaluates the dust loading on the workers of the deposit. The selection of plantings that have potential to neutralize the dust loading produced by the plot “Severniy” is carried out.

Testate amoebae analysis in the peat deposits of the swamp Dolgon’koye in the south of Western Siberia and peatland paleohydrology for last 3100 years

NASA Astrophysics Data System (ADS)

Kurina, Irina V.; Blyakharchuk, Tatiana A.

2018-03-01

Our research is devoted to paleohydrological reconstruction in the swamp located in the river valley on the piedmont of the Altai Mountains in the south of Western Siberia. The reconstruction was carried out based on rhizopod analysis for the last 3100 cal yr. A large amount of different testate amoebae was found in the peat. Total 64 testate amoebae taxa were recorded in the peat core with the most abundant being: Trinema lineare, Centropyxis aculeata, C. aerophila, Euglypha rotunda, Cryptodifflugia sp. Decrease of surface wetness in the swamp are observed 2280, 2140, 1900–600 cal yr BP and increase – in 2700, 2500–1900, 230–215 cal yr BP. The results of our reconstruction of the swamp paleohydrology agrees well with the paleoclimatic data obtained earlier for the central area of the south of Western Siberia Plain. It indicates a high sensitivity of the swamp to climatic changes in the Holocene. The rhizopod analysis proved to be very effective when used for paleohydrology reconstruction in minerotrophic peat.

Flooding on Russia's Lena River

NASA Technical Reports Server (NTRS)

2002-01-01

Nearly every year in the late spring, ice blocks the flow of water at the mouth of the Lena River in northeastern Russia and gives rise to floods across the Siberian plains. This year's floods can be seen in this image taken on June 2, 2002, by the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra satellite. The river runs down the left side of the image, and its delta is shrouded in ice (red) at the top of the image. Normally, the river would resemble a thin black line in MODIS imagery. The river, which is Russia's longest, flows 2,641 miles (4,250 kilometers) south to north through Siberia and into the Laptev Sea. In the winter, the river becomes nearly frozen. In the spring, however, water upstream thaws earlier than water at the mouth of the river. As the southern end of the river begins to melt, blocks of ice travel downstream to the still frozen delta, pile up, and often obstruct the flow of water. Flooding doesn't always occur on the same parts of the river. The floods hit further south last year. If the flooding grows severe enough, explosive charges are typically used to break up the ice jams. In these false-color images land areas are a dull, light green or tan, and water is black. Clouds appear pink, and ice comes across as bright red. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

Antidiabetic effects of the Cimicifuga racemosa extract Ze 450 in vitro and in vivo in ob/ob mice.

PubMed

Moser, C; Vickers, S P; Brammer, R; Cheetham, S C; Drewe, J

2014-09-25

It was the aim of the present experiments to examine potential antidiabetic effects of the Cimicifuga racemosa extract Ze 450. Ze 450 and some of its components (23-epi-26-deoxyactein, protopine and cimiracemoside C) were investigated in vitro for their effects on AMP-activated protein kinase (AMPK) compared to metformin in HepaRG cells. Ze 450 (given orally (PO) and intraperitonally (IP)), metformin (PO) and controls were given over 7 days to 68 male ob/ob mice. Glucose and insulin concentrations were measured at baseline and during an oral glucose tolerance test (OGTT). Ze 450 and its components activated AMPK to the same extent as metformin. In mice, Ze 450 (PO/IP) decreased significantly average daily and cumulative weight gain, average daily food and water intake, while metformin had no effect. In contrast to metformin, PO Ze 450 virtually did not change maximum glucose levels during OGTT, however, prolonged elimination. Ze 450 administered PO and IP decreased significantly post-stimulated insulin, whereas metformin did not. HOMA-IR index of insulin resistance improved significantly after IP and PO Ze 450 and slightly after metformin. In summary, the results demonstrate that Ze 450 reduced significantly body weight, plasma glucose, improved glucose metabolism and insulin sensitivity in diabetic ob/ob mice. In vitro experiments suggest that part of the effects may be related to AMPK activation. Ze 450 may have utility in the treatment of type 2 diabetes. However, longer term studies in additional animal models or patients with disturbed glucose tolerance or diabetes may be of use to investigate this further. Copyright © 2014 Elsevier GmbH. All rights reserved.

Glacial Refugium of Pinus pumila (Pall.) Regel in Northeastern Siberia

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

Shilo, N A; Lozhkin, A V; Anderson, P M

One of the most glowing representatives of the Kolyma flora [1], ''Pinus pumila'' (Pall.) Regel (Japanese stone pine), is a typical shrub in larch forests of the northern Okhotsk region, basins of the Kolyma and Indigirka rivers, and high-shrub tundra of the Chukchi Peninsula. It also forms a pine belt in mountains above the forest boundary, which gives way to the grass-underbrush mountain tundra and bald mountains. In the southern Chukchi Peninsula, ''Pinus pumila'' along with ''Duschekia fruticosa'' (Rupr.) Pouzar and ''Betula middendorffii'' Trautv. et C. A. Mey form trailing forests transitional between tundra and taiga [2]. Pinus pumila pollen,more » usually predominating in subfossil spore-and-pollen spectra of northeastern Siberia, is found as single grains or a subordinate component (up 2-3%, rarely 10%) in spectra of lacustrine deposits formed during the last glacial stage (isotope stage 2) in the Preboreal and Boreal times of the Holocene. Sometimes, its content increases to 15-22% in spectra of lacustrine deposits synchronous to the last glacial stage near the northern coast of the Sea of Okhotsk [3], evidently indicating the proximity of Japanese stone pine thickets.« less

Zinc metabolism in genetically obese (ob/ob) mice

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

Kennedy, M.L.; Failla, M.L.

1987-05-01

Recent reports indicate that the concentrations and total amounts of several essential trace metals in various tissues of genetically obese rodents differ markedly from those in lean controls. In the present studies the absorption, retention and tissue distribution of zinc and constitutive levels of zinc-metallothionein (Zn-MT) in selected tissues were compared in obese (ob/ob) and lean (+/.) C57BL/6J mice. When 5-, 10- and 22-wk-old mice were administered 1.2 mumol /sup 65/Zn by stomach tube the apparent absorption of /sup 65/Zn by obese mice was 1.5, 2.2 and 3.9 times higher, respectively, than that in age-matched lean mice. Retention of orallymore » administered /sup 65/Zn after 96 h was also substantially higher in obese mice than in lean mice. To assess the possible influences of hyperphagia and intestinal hypertrophy on the enhanced apparent absorption of /sup 65/Zn by obese mice food intake by an additional group of obese mice was restricted to that of age-matched lean controls. When actual absorption of zinc was determined according to the method of Heth and Hoekstra, groups of ad libitum--fed obese, pair-fed obese and lean mice absorbed 38, 32 and 18% of administered /sup 65/Zn, respectively. In contrast, the rate of /sup 65/Zn excretion 2-6 d after oral or subcutaneous administration of the metal was similar for obese and lean mice. Unrestricted and pair-fed obese mice had significantly lower percentages of carcass /sup 65/Zn present in skin, muscle plus bone, spleen and testes and higher percentages present in liver, small intestine and adipose tissue than lean mice.« less

Reduction of obesity, as induced by leptin, reverses endothelial dysfunction in obese (Lep(ob)) mice

NASA Technical Reports Server (NTRS)

Winters, B.; Mo, Z.; Brooks-Asplund, E.; Kim, S.; Shoukas, A.; Li, D.; Nyhan, D.; Berkowitz, D. E.

2000-01-01

Obesity is a major health care problem and is associated with significant cardiovascular morbidity. Leptin, a neuroendocrine hormone released by adipose tissue, is important in modulating obesity by signaling satiety and increasing metabolism. Moreover, leptin receptors are expressed on vascular endothelial cells (ECs) and mediate angiogenesis. We hypothesized that leptin may also play an important role in vasoregulation. We investigated vasoregulatory mechanisms in the leptin-deficient obese (ob/ob) mouse model and determined the influence of leptin replacement on endothelial-dependent vasorelaxant responses. The direct effect of leptin on EC nitric oxide (NO) production was also tested by using 4, 5-diaminofluorescein-2 diacetate staining and measurement of nitrate and nitrite concentrations. Vasoconstrictor responses to phenylephrine, norepinephrine, and U-46619 were markedly enhanced in aortic rings from ob/ob mice and were modulated by NO synthase inhibition. Vasorelaxant responses to ACh were markedly attenuated in mesenteric microvessels from ob/ob mice. Leptin replacement resulted in significant weight loss and reversal of the impaired endothelial-dependent vasorelaxant responses observed in ob/ob mice. Preincubation of ECs with leptin enhanced the release of NO production. Thus leptin-deficient ob/ob mice demonstrate marked abnormalities in vasoregulation, including impaired endothelial-dependent vasodilation, which is reversed by leptin replacement. These findings may be partially explained by the direct effect of leptin on endothelial NO production. These vascular abnormalities are similar to those observed in obese, diabetic, leptin-resistant humans. The ob/ob mouse may, therefore, be an excellent new model for the study of the cardiovascular effects of obesity.

Cygnus OB2: Star Formation Ugly Duckling Causes a Flap

NASA Astrophysics Data System (ADS)

Drake, Jeremy J.; Wright, Nicholas; Guarcello, Mario

2015-08-01

Cygnus OB2 is one of the largest known OB associations in our Galaxy, with a total stellar mass of 30,000 Msun and boasting an estimated 65 O-type stars and hundreds of OB stars. At a distance of only 1.4kpc, it is also the closest truly massive star forming region and provides a valuable testbed for star and planet formation theory. We have performed a deep stellar census using observations from X-ray to infrared, which has enabled studies of sub-structuring, mass segregation and dynamics, while infrared data reveal a story of protoplanetary disk attrition in an extremely harsh radiation environment. I will discuss how Cygnus OB2 challenges the idea that stars must form in dense, compact clusters, and demonstrates that stars as massive as 100 Msun can form in relatively low-density environments. Convincing evidence of disk photoevaporation poses a potential problem for planet formation and growth in starburst environments.

Carbon budget of oligotrophic mires in the Southern Taiga of Western Siberia under anthropogenic impact

NASA Astrophysics Data System (ADS)

Golovatskaya, Eugenia; Dyukarev, Egor

2010-05-01

Role of peatlands in the global greenhouse gases budget is highly relevant. According to present estimates peatlands in undisturbed conditions act as a sink for the atmospheric carbon. Anthropogenic impact on peatlands (melioration, changes in land use, influence of underground water catchments) results in water table lowering, changing in vegetation cover, and degradation of peat deposit. Peatlands could provide a significant positive feedback for climate changes if warming and peatlands drying stimulates bulk soil organic matter decomposition which enhances CO2 release to the atmosphere. Western Siberian peatlands usually represented big bog massifs. Big peatlands have higher stability to external influence. Small peatlands have all signs of big bogs but react on changes in environmental variables more quickly. The present study is devoted to investigation of primary carbon fluxes (CO2 emission and net primary productivity) and carbon balance at oligotrophic bogs in native condition (key area "Bakchar") and under anthropogenic impact (key area "Ob'-Tom'"). The key area "Bakchar" is located between the Iksa and Bakchar rivers (56o58`N 82o36`E) at the Bakcharskoe bog (area 1400 km2). The key area "Ob'-Tom'"is located in the northern part of Ob' and Tom' interfluve (56o21`N 82o31`E). The "Bakchar" key area includes the following ecosystems: pine- shrub-sphagnum community, a similar community with stunted (low) pine trees, and sedge-sphagnum fen. Two small peatlands were studied at Ob' and Tom' interfluve. Kirsanovskoe bog includes pine- shrub-sphagnum community and sedge fen. Timiryazevskoe bog was represented by pine- shrub-sphagnum (TPSS) community and sedge fen. An infrared gas analyzer OPTOGAS 500.4 (OPTEC Corp., St.-Petersburg, Russia) attached to a static opaque plastic been used for carbon dioxide emission measurements. The net primary productivity was measured by clipping method (Golovatskaya and Dyukarev, Plant Soil 2009). Peatlands at "Ob'-Tom'" key area

An allosteric antibody to the leptin receptor reduces body weight and reverses the diabetic phenotype in the Lep(ob) /Lep(ob) mouse.

PubMed

Bhaskar, Vinay; Goldfine, Ira D; Gerstner, Resi; Michelson, Kristen; Tran, Catarina; Nonet, Genevieve; Bohmann, David; Pongo, Elizabeth; Zhao, Jingsong; Horwitz, Arnold H; Takeuchi, Toshihiko; White, Mark; Corbin, John A

2016-08-01

Leptin (LEP) deficiency results in major metabolic perturbations, including obesity, dyslipidemia, and diabetes. Although LEP deficiency can be treated with daily injections of a recombinant LEP, generation of an antibody activating the LEP receptor (LEPR) that has both an intrinsically long half-life and low immunogenicity could be useful in the treatment of this condition. Phage display technology coupled with flow cytometry and cell-based in vitro assays were employed to identify an allosteric agonist of the mouse LEPR. LEP-deficient Lep(ob) /Lep(ob) mice were used to compare in vivo effects of LEP to antibody administration. To evaluate hypothalamic effects of treatment, changes in mRNA levels of neuropeptide Y and proopiomelanocortin were measured. XPA.80.037 is a monoclonal antibody that demonstrates allosteric agonism of the mouse LEPR. Treatment of Lep(ob) /Lep(ob) mice with XPA.80.037 markedly reduced hyperphagia and body weight, normalized blood glucose and plasma insulin levels, and corrected dyslipidemia. These metabolic alterations correlated with changes in mRNA levels of neuropeptide Y and proopiomelanocortin, suggesting that XPA.80.037 had hypothalamic effects. Agonist allosteric monoclonal antibodies to the LEPR can correct metabolic effects associated with LEP deficiency in vivo and thereby have the potential to treat conditions of LEP deficiency. © 2016 The Obesity Society.

Late Pleniglacial vegetation in eastern-central Europe: are there modern analogues in Siberia?

NASA Astrophysics Data System (ADS)

Magyari, Enikő Katalin; Kuneš, Petr; Jakab, Gusztáv; Sümegi, Pál; Pelánková, Barbora; Schäbitz, Frank; Braun, Mihály; Chytrý, Milan

2014-07-01

To characterize Late Pleniglacial (LPG: 26.5-15 ka cal BP) and particularly Last Glacial Maximum (LGM: 21 ± 2 ka cal BP) vegetation and climate, fossil pollen assemblages are often compared with modern pollen assemblages. Given the non-analogue climate of the LPG, a key question is how glacial pollen assemblages and thereby vegetation compare with modern vegetation. In this paper we present three LPG pollen records from the Carpathian Basin and the adjoining Carpathian Mountains to address this question and provide a concise compositional characterization of the LPG vegetation. Fossil pollen assemblages were compared with surface pollen spectra from the Altai-Sayan Mountains in southern Siberia. This area shows many similarities with the LPG vegetation of eastern-central Europe, and has long been considered as its best modern analogue. Ordination and analogue matching were used to characterize vegetation composition and find the best analogues. Our results show that few LPG pollen assemblages have statistically significant analogues in southern Siberia. When analogue pairings occur they suggest the predominance of wet and mesic grasslands and dry steppe in the studied region. Wooded vegetation types (continental and suboceanic hemiboreal forest, continental taiga) appear as significant analogues only in a few cases during the LGM and more frequently after 16 ka cal BP. These results suggest that the LPG landscape of the Carpathian Basin was dominated by dry steppe that occurred outside the river floodplains, while wet and mesic grasslands occurred in the floodplains and on other sites influenced by ground water. Woody vegetation mainly occurred in river valleys, on wet north-facing hillsides, and scattered trees were likely also present on the loess plateaus. The dominant woody species were Larix, Pinus sylvestris, Pinus mugo, Pinus cembra, Picea abies, Betula pendula/pubescens, Betula nana, Juniperus, Hippophaë rhamnoides, Populus, Salix and Alnus. The pollen

AIRS Obs4MIPs V2 data set

NASA Astrophysics Data System (ADS)

Tian, B.

2017-12-01

The Coupled Model Intercomparison Project (CMIP) has become a central element of national and international assessments of climate change. The CMIP Phase 6 (CMIP6) model experiments will be the foundation for the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6), scheduled for publication around 2021. To increase the fidelity of the IPCC AR6, the CMIP6 model experiments need rigorous evaluation. The "Observations for Model Intercomparison Projects" (Obs4MIPs) collects, organizes and publishes various well-established satellite data sets for CMIP model evaluation. The Atmospheric Infrared Sounder (AIRS) and Advanced Microwave Sounding Unit (AMSU), the NASA's temperature and humidity sounding system on the Aqua satellite, has provided over a decade-long high-quality tropospheric temperature and moisture sounding data. Under the current support of the NASA Data for Operation and Assessment (NDOA) program, we are generating and publishing the AIRS Obs4MIPs V2 data set including the monthly mean tropospheric air temperature, specific humidity, and relative humidity profiles from September 2002 to September 2016. This will provide the latest AIRS data in Obs4MIPs and assist the climate modeling community to better use the AIRS data for CMIP (including CMIP3, CMIP5, and CMIP6) model evaluation. In this presentation, we will discuss the AIRS Obs4MIPs V2 data set and their possible use for CMIP6 climate model evaluation.

Droughts and Excessive Moisture Events in Southern Siberia in the Late XXth - Early XXIst Centuries

NASA Astrophysics Data System (ADS)

Ryazanova, A. A.; Voropay, N. N.

2017-11-01

In recent years much research has been devoted to global and regional climate changes. Special attention was paid to climate extremes, such as droughts and excessive moisture events. In this study the moisture and aridity of Southern Siberia are estimated using web-GIS called “CLIMATE”. The system “CLIMATE” is part of a hardware and software cloud storage complex for data analysis of various climatic data sets, with algorithms for searching, extracting, processing, and visualizing the data. The ECMWF ERA-Interim reanalysis data for Southern Siberia (50-65°N, 60-120°E) from 1979 to 2010 with a grid cell of 0.75×0.75° is used. Some hydrothermal conditions are estimated using the so-called Ped index (Si), which is a normalized indicator of the ratio of air temperature to precipitation. The mountain regions of Eastern Siberia are becoming more and more arid each month during the last 30 years. In Western Siberia, aridity increases in May and decreases in June, in the other months positive and negative trends are found. The greatest differences between the trends of the aridity index (Si), air temperature, and precipitation are observed in July.

Mapping of Geographically Isolated Wetlands of Western Siberia Using High Resolution Space Images

NASA Astrophysics Data System (ADS)

Dyukarev, E.; Pologova, N.; Dyukarev, A.; Lane, C.; Autrey, B. C.

2014-12-01

Using the remote sensing data for integrated study of natural objects is actual for investigation of difficult to access areas of West Siberia. The research of this study focuses on determining the extent and spectral signatures of isolated wetlands within Ob-Tom Interfluve area using Landsat and Quickbird space images. High-resolution space images were carefully examined and wetlands were manually delineated. Wetlands have clear visible signs at the high resolution space images. 567 wetlands were recognized as isolated wetlands with the area about 10 000 ha (of 2.5% of the study area). Isolated wetlands with area less 2 ha are the most frequent. Half of the total amount of wetlands has area less than 6.4 ha. The largest isolated wetland occupies 797 ha, and only 5% have area more than 50 ha. The Landsat 7 ETM+ data were used for analysis of vegetation structure and spectral characteristics of wetlands. The masked isolated wetlands image was classified into 12 land cover classes using ISODATA unsupervised classification. The attribution of unsupervised classification results allowed us to clearly recognize 7 types of wetlands: tall, low and sparse ryams (Pine-Shrub-Sphagnum community), open wetlands with shrub, moss or sedge cover, and open water objects. Analysis of spectral profiles for all classes has shown that Landsat spectral bands 4 and 5 have higher variability. These bands allow to separate wetland classed definitely. Accuracy assessment of isolated wetland map shows a good agreement with expert field data. The work was supported by grants ISTC № 4079.

A reconstruction of vegetation and paleohydrologycal changes from peatland in Kansk forest-steppe, Yenisei Siberia

NASA Astrophysics Data System (ADS)

Rodionova, Alexandra

2016-04-01

Peatlands are an important natural archive for past climatic changes. Climatic changes throughout the Holocene have been reconstructed from peat using a wide array of biological and other proxies. Many different proxy indicators can be derived from peat cores allowing for a multi-proxy approach to climatic reconstructions. Peat-based climatic and environmental reconstructions are currently available from many sites in Yenisei Siberia, mainly for its northern territories. The purpose of this paper is to study some features of peatland development and environmental reconstructions from the Holocene period in the south part of Yenisei Siberia (Kansk forest-steppe zone). The main method used in this research is macrofossil analysis. It can be used to reconstruct the development of local vegetation and surface wetness on peatlands. The macrofossil analysis in the peat resulted from the study of the vegetation in a particular place over a period of time, and it allowed the reconstruction of environmental changes that have occurred since the Late Glacial. Then we used ecological scales of moisture and reconstructed surface wetness for the entire period of the bog formation. Radiocarbon dating was carried out at Sobolev Institute of Geology and Mineralogy, Russian Academy of Sciences, Novosibirsk . Peatland "Pinchinskoye" was selected for investigation in Kansk forest-steppe. It is located on the right bank of the Yenisei River in the floodplain of Esaulovka River. Peat cores of 350 cm were selected in the southern part of the peatbog, including 225 cm of peat (with loam layers in the range of 90 to 135 cm), 75 cm of organic and mineral sapropel with the inclusion of fossil shells of mollusks and different plant macrofossils and 50 cm of the loam below. The process of peat accumulation dated back 8400 ± 140 years, which is the oldest date for the forest-steppe zone of Yenisei Siberia. The climate of Boreal period of the Holocene was chilly. Under these conditions, in the

Potential sources of Southern Siberia aerosols by data of AERONET site in Tomsk, Russia

NASA Astrophysics Data System (ADS)

Shukurov, K. A.; Shukurova, L. M.

2017-11-01

For all days of measurements in 2002-2015 of volume concentration of aerosols at the AERONET Tomsk/Tomsk-22 station an array of 10-day backward trajectories of air parcels arriving in Tomsk into seven layers of the troposphere with heights in the range of 0.5-5.0 km is calculated using the trajectory model NOAA HYSPLIT_4. For the three fractions of the aerosol with particle sizes < 1.0 μm, 1.0-2.5 μm, 2.5-5.0 μm and their sum (< 5.0 μm), the field of capacity of the potential sources of aerosols of these fractions for southern Siberia is determined by the CWT (concentration weighted trajectory) method using the backward trajectory array. The analysis is carried out taking into account the processes both the scavenging of the aerosols with precipitation and the dry deposition. Trajectories arriving at different heights were analyzed taking into account the weight coefficients proportional to the backward light scattering coefficients of an aerosols at corresponding heights for warm and cold seasons in Western Siberia. The most capable (in unit of volume concentration μm3 /μm2 ) potential sources of these fractions for southern Siberia are located above North Africa, Eastern Siberia, Central Asia and the Dzhungarian desert in the Xinjiang-Uyghur Autonomous Region of China.

SPM response to tide and river flow in the hyper-turbid Ems River

NASA Astrophysics Data System (ADS)

Winterwerp, Johan C.; Vroom, Julia; Wang, Zheng-B.; Krebs, Martin; Hendriks, Erik C. M.; van Maren, Dirk S.; Schrottke, Kerstin; Borgsmüller, Christine; Schöl, Andreas

2017-05-01

In this paper, we analyse the behaviour of fine sediments in the hyper-turbid Lower Ems River, with focus on the river's upper reaches, a stretch of about 25 km up-estuary of Terborg. Our analysis is based on long records of suspended particulate matter (SPM) from optical backscatter (OBS) measurements close to the bed at seven stations along the river, records of salinity and water level measurements at these stations, acoustic measurements on the vertical mud structure just up-estuary of Terborg and oxygen profiles in the lower 3 m of the water column close to Leerort and Terborg. Further, we use cross-sectionally averaged velocities computed with a calibrated numerical model. Distinction is made between four timescales, i.e. the semi-diurnal tidal timescale, the spring-neap tidal timescale, a timescale around an isolated peak in river flow (i.e. about 3 weeks) and a seasonal timescale. The data suggest that a pool of fluid/soft mud is present in these upper reaches, from up-estuary of Papenburg to a bit down-estuary of Terborg. Between Terborg and Gandersum, SPM values drop rapidly but remain high at a few gram per litre. The pool of fluid/soft mud is entrained/mobilized at the onset of flood, yielding SPM values of many tens gram per litre. This suspension is transported up-estuary with the flood. Around high water slack, part of the suspension settles, being remixed during ebb, while migrating down-estuary, but likely not much further than Terborg. Around low water slack, a large fraction of the sediment settles, reforming the pool of fluid mud. The rapid entrainment from the fluid mud layer after low water slack is only possible when the peak flood velocity exceeds a critical value of around 1 m/s, i.e. when the stratified water column seems to become internally supercritical. If the peak flood velocity does not reach this critical value, f.i. during neap tide, fluid mud is not entrained up to the OBS sensors. Thus, it is not classical tidal asymmetry, but

[Entification of the Rubella virus genotype 1H in Western Siberia].

PubMed

Seregin, S V; Babkin, I V; Petrova, I D; Iashina, L N; Malkova, E M; Petrov, V S

2011-01-01

Molecular epidemiological study of novel strain of Rubella virus isolated during the outbreak in Western Siberia in 2004 was described. Detailed phylogenetic analysis performed based upon entire SP-region, which encodes all three Rubella structural proteins (C, E2, and E1), was implemented. This analysis provides characterization of this strain and classifies it as 1H genotype, thereby correcting previous classification of this strain based upon shorter nucleotide sequence, only encoding E1 protein. Therefore, this study identified the genotype of the Rubella virus not previously detected in Western Siberia (and even entire Russian Federation), which highlights the importance of more extensive characterization of genetic variability of the Rubella virus, especially with regard to potential influence of vaccination on the Rubella virus mutagenesis.

Changes of Geo-Runoff Components in Russian Arctic Rivers

NASA Astrophysics Data System (ADS)

Groisman, P. Y.; Georgiadi, A.; Kashutina, E.; Milyukova, I.

2017-12-01

Long-term phases of changes in naturalized components of the geo-runoff (streamflow, heat flow and suspended sediment yield) of Russian Arctic Rivers during the period of observation (from 1930-1940 till 2000s) were revealed on the basis of normalized cumulative curves. Their characteristics and the effects of impact of anthropogenic factors are evaluated. Since 1930-1940s till the beginning of the 21st century, the naturalized annual and seasonal river runoff in the largest river basins (Ob', Yenisei, Lena) was characterized by two main long-term phases of its changes. The phase of decreased runoff (since the 1930-1940s) was replaced in the 1970-1980s by a long-term phase of increased streamflow. The duration of phases was several decades and are characterized by significant runoff differences. In the long-term variations of the heat flow of the Ob, Yenisei, Lena, Northern Dvina and Pechora also were found two major long-term phases. The phase of the heat flow decrease, which began in 1930-1940-ies and lasted for 35-55 years, was replaced in 1970-1980 by 20-year phase of its increase (except the Yenisei, where this phase began in the late 1990s.) and has continued until now. Similar long-term phases are observed for river water temperature of considered rivers. Differences in heat flow reaches 20% during the phase of its increased and decreased values for the Northern Dvina and the Yenisei Rivers, but for other rivers they are not higher than 10%. Long-term changes of annual suspended sediment yield for the Yenisei and Lena Rivers are also characterized by two major long-term phases, which replaced each another in the 1970-1990. Differences in the suspended sediment yield during the increase and decrease phases reach 40% for Lena, whereas for Yenisei they are substantially less (10%). Anthropogenic factors (mainly water reservoirs) have significantly changed the characteristics of the long-term phases on the Yenisei River while their impact is not significant on

A Behavioral Approach to Improving Self-Care Skills in OBS Patients.

ERIC Educational Resources Information Center

McEvoy, Cathy L.; Patterson, Roger L.

Traditionally, the treatment of geriatric patients suffering from Organic Brain Syndrome (OBS) has been characterized by non-therapeutic custodial care. To determine whether elderly clients with dementia can benefit from self-care skill training, and to compare their progress with clients without OBS, 30 clients of the Residential Aging Program in…

Industrial Development of Siberia and the Soviet Far East.

DTIC Science & Technology

1984-09-01

21 (This argument is perhaps unintentionally fed by the central leadership’s emphasis on investing in renovation and technical reequipment of...Malov, "Po programme ’ energia ’," Pravda, May 12, 1982, p. 2. " M. Matafonov, "Open up Siberia’s Treasure Houses," Sotsialisticheskaia industriia

PHOTOEVAPORATING PROPLYD-LIKE OBJECTS IN CYGNUS OB2

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

Wright, Nicholas J.; Drake, Jeremy J.; Guarcello, Mario G.

2012-02-20

We report the discovery of 10 proplyd-like objects in the vicinity of the massive OB association Cygnus OB2. They were discovered in IPHAS H{alpha} images and are clearly resolved in broadband Hubble Space Telescope/Advanced Camera for Surveys, near-IR, and Spitzer mid-IR images. All exhibit the familiar tadpole shape seen in photoevaporating objects such as the Orion proplyds, with a bright ionization front at the head facing the central cluster of massive stars and a tail stretching in the opposite direction. Many also show secondary ionization fronts, complex tail morphologies, or multiple heads. We consider the evidence that these are eithermore » proplyds or 'evaporating gaseous globules' (EGGs) left over from a fragmenting molecular cloud, but find that neither scenario fully explains the observations. Typical sizes are 50,000-100,000 AU, larger than the Orion proplyds, but in agreement with the theoretical scaling of proplyd size with distance from the ionizing source. These objects are located at projected separations of {approx}6-14 pc from the OB association, compared to {approx}0.1 pc for the Orion proplyds, but are clearly being photoionized by the {approx}65 O-type stars in Cyg OB2. Central star candidates are identified in near- and mid-IR images, supporting the proplyd scenario, though their large sizes and notable asymmetries are more consistent with the EGG scenario. A third possibility is therefore considered that these are a unique class of photoevaporating partially embedded young stellar objects that have survived the destruction of their natal molecular cloud. This has implications for the properties of stars that form in the vicinity of massive stars.« less

NEAR INFRARED DIFFUSE INTERSTELLAR BANDS TOWARD THE CYGNUS OB2 ASSOCIATION

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

Hamano, Satoshi; Kondo, Sohei; Sameshima, Hiroaki

2016-04-10

We obtained the near-infrared (NIR) high-resolution (R ≡ λ/Δλ ∼ 20,000) spectra of the seven brightest early-type stars in the Cygnus OB2 association for investigating the environmental dependence of diffuse interstellar bands (DIBs). The WINERED spectrograph mounted on the Araki 1.3 m telescope in Japan was used to collect data. All 20 of the known DIBs within the wavelength coverage of WINERED (0.91 < λ < 1.36 μm) were clearly detected along all lines of sight because of their high flux density in the NIR wavelength range and the large extinction. The equivalent widths (EWs) of DIBs were not correlated with the column densities of C{sub 2} molecules,more » which trace the patchy dense component, suggesting that the NIR DIB carriers are distributed mainly in the diffuse component. On the basis of the correlations among the NIR DIBs both for stars in Cyg OB2 and stars observed previously, λλ10780, 10792, 11797, 12623, and 13175 are found to constitute a “family,” in which the DIBs are correlated well over the wide EW range. In contrast, the EW of λ10504 is found to remain almost constant over the stars in Cyg OB2. The extinction estimated from the average EW of λ10504 (A{sub V} ∼ 3.6 mag) roughly corresponds to the lower limit of the extinction distribution of OB stars in Cyg OB2. This suggests that λ10504 is absorbed only by the foreground clouds, implying that the carrier of λ10504 is completely destroyed in Cyg OB2, probably by the strong UV radiation field. The different behaviors of the DIBs may be caused by different properties of the DIB carriers.« less

ObsPy: A Python Toolbox for Seismology

NASA Astrophysics Data System (ADS)

Krischer, Lion; Megies, Tobias; Sales de Andrade, Elliott; Barsch, Robert; MacCarthy, Jonathan

2017-04-01

In recent years the Python ecosystem evolved into one of the most powerful and productive scientific environments across disciplines. ObsPy (https://www.obspy.org) is a fully community-driven, open-source project dedicated to providing a bridge for seismology into that ecosystem. It does so by offering Read and write support for essentially every commonly used data format in seismology with a unified interface and automatic format detection. This includes waveform data (MiniSEED, SAC, SEG-Y, Reftek, …) as well as station (SEED, StationXML, …) and event meta information (QuakeML, ZMAP, …). Integrated access to the largest data centers, web services, and real-time data streams (FDSNWS, ArcLink, SeedLink, ...). A powerful signal processing toolbox tuned to the specific needs of seismologists. Utility functionality like travel time calculations with the TauP method, geodetic functions, and data visualizations. ObsPy has been in constant development for more than seven years and is developed and used by scientists around the world with successful applications in all branches of seismology. Additionally it nowadays serves as the foundation for a large number of more specialized packages. This presentation will give a short overview of the capabilities of ObsPy and point out several representative or new use cases. Additionally we will discuss the road ahead as well as the long-term sustainability of open-source scientific software.

Comparative analysis of marine paleogene sections and biota from West Siberia and the Arctic Region

NASA Astrophysics Data System (ADS)

Akhmet'ev, M. A.; Zaporozhets, N. I.; Iakovleva, A. I.; Aleksandrova, G. N.; Beniamovsky, V. N.; Oreshkina, T. V.; Gnibidenko, Z. N.; Dolya, Zh. A.

2010-12-01

The analysis of the main biospheric events that took place in West Siberia and the Arctic region during the Early Paleogene revealed the paleogeographic and paleobiogeographic unity of marine sedimentation basins and close biogeographic relations between their separate parts. Most biotic and abiotic events of the first half of the Paleogene in the Arctic region and West Siberia were synchronous, unidirectional, and interrelated. Shelf settings, sedimentation breaks, and microfaunal assemblages characteristic of these basins during the Paleogene are compared. The comparative analysis primarily concerned events of the Paleocene-Eocene thermal maximum (PETM) and beds with Azolla (aquatic fern). The formation of the Eocene Azolla Beds in the Arctic region and West Siberia was asynchronous, although it proceeded in line with a common scenario related to the development of a system of estuarine-type currents in a sea basin partly isolated from the World Ocean.

Metabolic profiling of ob/ob mouse fatty liver using HR-MAS 1H-NMR combined with gene expression analysis reveals alterations in betaine metabolism and the transsulfuration pathway.

PubMed

Gogiashvili, Mikheil; Edlund, Karolina; Gianmoena, Kathrin; Marchan, Rosemarie; Brik, Alexander; Andersson, Jan T; Lambert, Jörg; Madjar, Katrin; Hellwig, Birte; Rahnenführer, Jörg; Hengstler, Jan G; Hergenröder, Roland; Cadenas, Cristina

2017-02-01

Metabolic perturbations resulting from excessive hepatic fat accumulation are poorly understood. Thus, in this study, leptin-deficient ob/ob mice, a mouse model of fatty liver disease, were used to investigate metabolic alterations in more detail. Metabolites were quantified in intact liver tissues of ob/ob (n = 8) and control (n = 8) mice using high-resolution magic angle spinning (HR-MAS) 1 H-NMR. In addition, after demonstrating that HR-MAS 1 H-NMR does not affect RNA integrity, transcriptional changes were measured by quantitative real-time PCR on RNA extracted from the same specimens after HR-MAS 1 H-NMR measurements. Importantly, the gene expression changes obtained agreed with those observed by Affymetrix microarray analysis performed on RNA isolated directly from fresh-frozen tissue. In total, 40 metabolites could be assigned in the spectra and subsequently quantified. Quantification of lactate was also possible after applying a lactate-editing pulse sequence that suppresses the lipid signal, which superimposes the lactate methyl resonance at 1.3 ppm. Significant differences were detected for creatinine, glutamate, glycine, glycolate, trimethylamine-N-oxide, dimethylglycine, ADP, AMP, betaine, phenylalanine, and uridine. Furthermore, alterations in one-carbon metabolism, supported by both metabolic and transcriptional changes, were observed. These included reduced demethylation of betaine to dimethylglycine and the reduced expression of genes coding for transsulfuration pathway enzymes, which appears to preserve methionine levels, but may limit glutathione synthesis. Overall, the combined approach is advantageous as it identifies changes not only at the single gene or metabolite level but also deregulated pathways, thus providing critical insight into changes accompanying fatty liver disease. Graphical abstract A Evaluation of RNA integrity before and after HR-MAS 1 H-NMR of intact mouse liver tissue. B Metabolite concentrations and gene expression

Monitoring industrial contaminants release to Russian Arctic rivers

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

NONE

1995-12-31

Reports suggest that over 100 billion metric tons of mixed industrial wastes have been dumped or disposed of in the Northern and Arctic regions of the former Soviet Union in crude landfill facilities or directly into rivers. GERG has undertaken studies in two of the principal river systems transporting contaminants from large watersheds to the Arctic Ocean and Kara Seas, and has obtained samples of sediment and biota for analysis. In the current phase of the study, 20 surficial sediments down each of the axis of the Ob and Yenisey Rivers into the Kara Sea were analyzed for industrially derivedmore » trace organic compounds (hydrocarbons, pesticides, PCBs) and trace metals. Twenty sediments from the two rivers were subjected to high resolution OCIMS analysis for dioxins, furans, and coplanar PCBs to determine the concentrations of these industrial pollutants. In addition, similar analyses were conducted on 10 tissue samples (fish and other invertebrate animals) down the axis of each river.« less

Contradicting climate versus vegetation history in NE-Siberia?

NASA Astrophysics Data System (ADS)

Zech, M.; Zech, R.

2009-04-01

Northern Siberia may play a key role for the climate on the entire Earth. The classical Milankovitch Theory suggests that changes in summer insolation due to the Earth' orbital parameters caused build-up of snow and ice over the extensive continental masses at high northern latitudes. Various positive feedback mechanisms, like surface albedo and sequestration/release of atmospheric carbon dioxide in/from frozen, organic-rich soils, could then be responsible for the onset of global glaciations. More recently, high northern latitudes have also gained a lot of attention due to the potential of their soils and peats to release large amounts of methane and carbon dioxide. The Siberian ecosystems may turn into significant greenhouse gas sources as global warming continues and causes melting of permafrost and mineralisation of soil organic material that has been built up and stored over thousands of years. Quaternary scientists are therefore searching for long-term and continuous archives in order to reconstruct the Siberian climate and landscape history. A wide range of different analytical tools (e.g. different dating techniques, elemental composition, mineralogy, magnetic properties, grain size distribution, characterisation of organic matter and palynology) is used to infer palaeoclimatically and palaeoecologically relevant information. All of these methods have their advantages and their disadvantages. For instance, pollen analyses allow a high taxonomic differentiation, but variable pollination rates of different plant species, influx of long-distance transported pollen, and variable preservation of different pollen taxa have to be considered. Concerning the interpretation of pollen spectra in NE-Siberia, arboreal pollen, especially larch pollen, are traditionally considered to be ‘warm plant taxa', hence the occurrence of these pollen in archives is interpreted as reflecting warm interglacial or interstadial conditions. We have recently presented a multi

Methane turnover and methanotrophic communities in arctic aquatic ecosystems of the Lena Delta, Northeast Siberia.

PubMed

Osudar, Roman; Liebner, Susanne; Alawi, Mashal; Yang, Sizhong; Bussmann, Ingeborg; Wagner, Dirk

2016-08-01

Large amounts of organic carbon are stored in Arctic permafrost environments, and microbial activity can potentially mineralize this carbon into methane, a potent greenhouse gas. In this study, we assessed the methane budget, the bacterial methane oxidation (MOX) and the underlying environmental controls of arctic lake systems, which represent substantial sources of methane. Five lake systems located on Samoylov Island (Lena Delta, Siberia) and the connected river sites were analyzed using radiotracers to estimate the MOX rates, and molecular biology methods to characterize the abundance and the community composition of methane-oxidizing bacteria (MOB). In contrast to the river, the lake systems had high variation in the methane concentrations, the abundance and composition of the MOB communities, and consequently, the MOX rates. The highest methane concentrations and the highest MOX rates were detected in the lake outlets and in a lake complex in a flood plain area. Though, in all aquatic systems, we detected both, Type I and II MOB, in lake systems, we observed a higher diversity including MOB, typical of the soil environments. The inoculation of soil MOB into the aquatic systems, resulting from permafrost thawing, might be an additional factor controlling the MOB community composition and potentially methanotrophic capacity. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Historical earthquakes studies in Eastern Siberia: State-of-the-art and plans for future

NASA Astrophysics Data System (ADS)

Radziminovich, Ya. B.; Shchetnikov, A. A.

2013-01-01

Many problems in investigating historical seismicity of East Siberia remain unsolved. A list of these problems may refer particularly to the quality and reliability of data sources, completeness of parametric earthquake catalogues, and precision and transparency of estimates for the main parameters of historical earthquakes. The main purpose of this paper is to highlight the current status of the studies of historical seismicity in Eastern Siberia, as well as analysis of existing macroseismic and parametric earthquake catalogues. We also made an attempt to identify the main shortcomings of existing catalogues and to clarify the reasons for their appearance in the light of the history of seismic observations in Eastern Siberia. Contentious issues in the catalogues of earthquakes are considered by the example of three strong historical earthquakes, important for assessing seismic hazard in the region. In particular, it was found that due to technical error the parameters of large M = 7.7 earthquakes of 1742 were transferred from the regional catalogue to the worldwide database with incorrect epicenter coordinates. The way some stereotypes concerning active tectonics influences on the localization of the epicenter is shown by the example of a strong М = 6.4 earthquake of 1814. Effect of insufficient use of the primary data source on completeness of earthquake catalogues is illustrated by the example of a strong M = 7.0 event of 1859. Analysis of the state-of-the-art of historical earthquakes studies in Eastern Siberia allows us to propose the following activities in the near future: (1) database compilation including initial descriptions of macroseismic effects with reference to their place and time of occurrence; (2) parameterization of the maximum possible (magnitude-unlimited) number of historical earthquakes on the basis of all the data available; (3) compilation of an improved version of the parametric historical earthquake catalogue for East Siberia with

Norilsk, Siberia

NASA Technical Reports Server (NTRS)

2008-01-01

Norilsk is a major city in Krasnoyarsk Krai, Russia, and the northernmost city in Siberia. The city was founded in the 1930s as a settlement for the Norilsk mining-metallurgic complex, sitting near the largest nickel-copper-palladium deposits on Earth. Mining and smelting of nickel, copper, cobalt, platinum, palladium are the major industries. The nickel ore is smelted on site at Norilsk. The smelting is directly responsible for severe pollution, generally acid rain and smog. By some estimates, 1 percent of the entire global emissions of sulfur dioxide comes from this one city. Heavy metal pollution near Norilsk is so severe that it is now economically feasible to mine the soil, which has been polluted so severely that it has economic grades of platinum and palladium.

The image was acquired July 21, 2000, covers an area of 36.9 x 37.6 km, and is located at 69.3 degrees north latitude, 88.2 degrees east longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Potential Climate-driven Silvicultural and Agricultural Transformations in Siberia in the 21 Century

NASA Astrophysics Data System (ADS)

Tchebakova, N. M.; Parfenova, E. I.; Shvetsov, E.; Soja, A. J.

2017-12-01

Simulations of Siberian forests in a changing climate showed them to be changed in composition, decreased, and shifted northwards. Our goals were to evaluate the ecological consequences for the forests and agriculture in Siberia and to offer adaptive measures that may be undertaken to minimize negative consequences and maximize benefits from a rapidly changing environment in the socially important region of southern Siberia. We considered two strategies to estimate climate-change effects on potentially failing forests within an expanding forest-steppe ecotone. To support forestry, seed transfers from locations that are best suited to the genotypes in future climates may be applied to assist trees and forests in a changing climate. To support agriculture, in view of the growing world concerns on food safety, new farming lands may be established in a new forest-steppe ecotone with its favorable climatic and soil resources. We used our bioclimatic vegetation models of various levels: a forest type model to predict forest shifts and forest-failing lands, tree species range and their climatypes models to predict what tree species/climatype would be suitable and crop models to predict crops to introduce in potentially climate-disturbed areas in Siberia. Climate change data for the 2080s were calculated from the ensemble of 20 general circulation models of the Coupled Model Intercomparison Project phase 5 (CMIP5) and two scenarios to characterize the range of climate change: mild climate (RCP2.6 scenario) and sharp climate (RCP 8.5 scenario). By the 2080s, forest-steppe and steppe rather than forests would dominate up to half of Siberia in the warmer and dryer RCP 8.5 climate. Water stress tolerant and fire-resistant light-needled species Pinus sylvestris and Larix spp. would dominate the forest-steppe ecotone. Failing forests in a dryer climate may be maintained by moving and substituting proper climatypes from locations often hundreds of km away. Agriculture in Siberia

Late orogenic processes between Baltica and Siberia cratons during the building of Pangea

NASA Astrophysics Data System (ADS)

Puchkov, V.

2003-04-01

Since the Middle Carboniferous, the territory between the Baltica, Kazakhstania and Siberia plates have been part of the continental crust, the last oceanic crust having by then been subducted. At this time continent-continent collision started and proceeded until the latest epochs of the Paleozoic, forming the Uralide orogen. Two features of this collision standout: 1) The northward movement of the Kazakhstanian block between the Baltica and Siberia plates resulted in a large-scale oroclinal bend of structures in West Siberia, which is well expressed in the magnetic field, as well as in the exposed Kazakhstanian structures, and 2) The orogenic event affected the whole territory between the Baltica and Siberia cratons, including the Kazakhstanian continent. A series of intermontane molasse basins are distributed throughout the orogen and in some places, like Bolshoi Karatau, are affected by Late Paleozoic deformation. Continent-continent collision had ceased by the end of the Permian, and in many places Triassic sediments unconformably overly the orogen. Triassic sedimentary sequences are typically coarse-grained (eventually proluvial), evidencing a new stage of mountain building, though many researchers have attributed this to a superplume event. The reason being the widespread flood basalt eruptions that took place not only between, but also on the cratons under discussion. There is a point of view that the break-up of the supercontinents (e.g., Pangea and Rodinia) was preceded by such a superplume event, passing to formation of linear graben systems and then to oceanic spreading. In the case under discussion, the process was arrested (the West Siberian basin with its grabens is often called a "failed ocean"). There is reason to suspect that the Paleozoic collision that led to formation of the Uralides left an enclosed ocean basin in the North, between the Baltica and Siberia plates. Only in the Early Jurassic, with the advent of the Old Kimmerian collision did

Leptin stimulates bone formation in ob/ob mice at doses having minimal impact on energy metabolism.

PubMed

Philbrick, Kenneth A; Wong, Carmen P; Branscum, Adam J; Turner, Russell T; Iwaniec, Urszula T

2017-03-01

Leptin, the protein product of the ob gene, is essential for normal bone growth, maturation and turnover. Peripheral actions of leptin occur at lower serum levels of the hormone than central actions because entry of leptin into the central nervous system (CNS) is limited due to its saturable transport across the blood-brain barrier (BBB). We performed a study in mice to model the impact of leptin production associated with different levels of adiposity on bone formation and compared the response with well-established centrally mediated actions of the hormone on energy metabolism. Leptin was infused (0, 4, 12, 40, 140 or 400 ng/h) for 12 days into 6-week-old female ob/ob mice (n = 8/group) using sc-implanted osmotic pumps. Treatment resulted in a dose-associated increase in serum leptin. Bone formation parameters were increased at EC 50 infusion rates of 7-17 ng/h, whereas higher levels (EC 50 , 40-80 ng/h) were required to similarly influence indices of energy metabolism. We then analyzed gene expression in tibia and hypothalamus at dose rates of 0, 12 and 140 ng/h; the latter dose resulted in serum leptin levels similar to WT mice. Infusion with 12 ng/h leptin increased the expression of genes associated with Jak/Stat signaling and bone formation in tibia with minimal effect on Jak/Stat signaling and neurotransmitters in hypothalamus. The results suggest that leptin acts peripherally to couple bone acquisition to energy availability and that limited transport across the BBB insures that the growth-promoting actions of peripheral leptin are not curtailed by the hormone's CNS-mediated anorexigenic actions. © 2017 Society for Endocrinology.

The Seismic Broad Band Western Mediterranean (wm) Network and the Obs Fomar Pool: Current state and Obs activities.

NASA Astrophysics Data System (ADS)

Pazos, Antonio; Davila, Jose Martin; Buforn, Elisa; Bezzeghoud, Mourad; Harnafi, Mimoun; Mattesini, Mauricio; Caldeira, Bento; Hanka, Winfried; El Moudnib, Lahcen; Strollo, Angelo; Roca, Antoni; Lopez de Mesa, Mireya; Dahm, Torsten; Cabieces, Roberto

2016-04-01

The Western Mediterranean (WM) seismic network started in 1996 as an initiative of the Royal Spanish Navy Observatory (ROA) and the Universidad Complutense de Madrid (UCM), with the collaboration of the GeoForschungsZentrum (GFZ) of Potsdam. A first broad band seismic station (SFUC) was installed close to Cádiz (South Spain). Since then, additional stations have been installed in the Ibero-Moghrebian region. In 2005, the "WM" code was assigned by the FDSN and new partners were jointed: Evora University (UEVO, Portugal), the Scientifique Institute of Rabat (ISRABAT, Morocco), and GFZ. Now days, the WM network is composed by 15 BB stations, all of them with Streckaisen STS-2 or STS-2.5 sensors, Quanterra or Earthdata digitizers and SeiscomP. Most them have co-installed a permanent geodetic GPS stations, and some them also have an accelerometer. There are 10 stations deployed in Spanish territory (5 in the Iberian peninsula, 1 in Balearic islands and 4 in North Africa Spanish places) with VSAT or Internet communications, 2 in Portugal (one of them without real time), and 3 in Morocco (2 VSAT and 1 ADSL). Additionally, 2 more stations (one in South Spain and one in Morocco) will be installed along this year. Additionally ROA has deployed a permanent real time VBB (CMG-3T: 360s) station at the Alboran Island. Due to the fact that part of the seismic activity is located at marine areas, and also because of the poor geographic azimuthal coverage at some zones provided by the land stations (specially in the SW of the San Vicente Cape area), ROA and UCM have acquired six broad band "LOBSTERN" OBS, manufactured by KUM (Kiel, Germany), conforming the OBS FOMAR pool. Three of them with CMG-40T sensor and the other with Trillium 120. These OBS were deployed along the Gibraltar strait since January to November 2014 to study the microseismicity in the Gibraltar strait area. In September 2015 FOMAR network has been deployed in SW of the San Vicente Cape for 8 months as a part of

Cnidarian-like embryos associated with the first shelly fossils in Siberia

NASA Astrophysics Data System (ADS)

Kouchinsky, Artem; Bengtson, Stefan; Gershwin, Lisa-Ann

1999-07-01

Phosphatized spheroids, ˜0.5 mm in diameter, in the Lower Cambrian Manykay Formation at the Bol'shaya Kuonamka River in northern Sakha (Yakutia) are interpreted as cnidarian embryos of late developmental stages. One of the poles has a double cross-like structure, consisting of two sets of four bands each. The bands of the upper set radiate at 90° from each other; those of the lower set also radiate at about right angles from each other, but the set is rotated 45° in respect to the upper set. Although there is a resemblance to the cross-like arrangements of cells in pregastrulation spiralian eggs, in particular those of annelids, the combined evidence favors an interpretation of the bands as incipient tentacles of a cnidarian actinula larva. The embryos occur with one of the first assemblages of shelly fossils in northern Siberia, that of the Angustiochrea lata zone. The co-occurring shelly fossils, anabaritids, probably also represent the phylum Cnidaria, but because their tubes have a consistent triradial symmetry, the connection with the tetraradially symmetrical embryos is problematic. The size of the embryos suggests that they are nonplanktotrophic, and the presence of actinula-like features suggests the lack of a free planula stage.

Improving OBS operations in ultra-deep ocean during the Southern Mariana Trench expeditions

NASA Astrophysics Data System (ADS)

Zeng, X.; Lin, J.; Xu, M.; Zhou, Z.

2017-12-01

The Mariana Trench Research Initiative, led by the South China Sea Institute of Oceanology of the Chinese Academy of Sciences and through international collaboration, focuses on investigating the deep and shallow lithospheric structure, earthquake characteristics, extreme geological environments, and the controlling geodynamic mechanisms for the formation of Earth's deepest basins in the southern Mariana Trench. Two multidisciplinary research expeditions were executed during December 2016 and June 2017, respectively, on board R/V Shiyan 3. A main task of the Mariana Initiative is to conduct the Southern Mariana OBS Experiment (SMOE), the first OBS seismic experiment across the Challenger Deep. The SMOE expeditions include both active and passive source seismic experiments and employed a large number of broadband OBS instruments. Due to the deep water, rough weather, strong winds, and other unfavorable factors, it was challenging to deploy/recover the OBSs. During the two expeditions we developed and experimented with a number of ways to improve the success rate of OBS operations in the harsh ultra-deep ocean environment of the Southern Mariana Trench. All newly acquired OBSs underwent a series of uniquely designed deep-ocean tests to improve the instrument performance and maximize reliability during their deployment under the ultra-high pressure conditions. The OBS deployment and recovery followed a unified standard operation procedure and aided by an instrumental checklist, which were specifically designed and strictly enforced for operation during the expeditions. Furthermore, an advanced ship-based radio positioning system was developed to rapidly and accurately locate the OBS instruments when they reached the sea surface; the system proved its effectiveness even under extreme weather conditions. Through the development and application of the novel methods for operation in deep oceans, we overcame the rough sea and other unfavorable factors during the first two

OBS development for long term observation in the Marmara Sea, NW Turkey

NASA Astrophysics Data System (ADS)

Takahashi, Narumi; Shimizu, Satoshi; Maekawa, Takuya; Kalafat, Dogan; Pinar, Ali; Citak, Seckin; Kaneda, Yoshiyuki

2015-04-01

We have carried out a collaboration study between Japan and Turkey since 2013, which is one of SATREPS projects, "Earthquake and Tsunami Disaster Mitigation in The Marmara Region and Disaster Education in Turkey". The main objective of this project is to reduce risk brought by earthquakes and tsunamis. In particular, the North Anatolian Fault system runs through the Marmara sea and it is expected that the seismic gap exists there according to past seismic studies. The details of seismicity distribution in the Marmara Sea is, however, still insufficient to construct fault model along the active faults. Therefore, we prepare ten ocean bottom seismographs (OBSs) to realize long term observation. We aim to identify size and depth of seismogenic zones using micro seismicity. In addition, we need to cover relative broad area from off-shore Istanbul city to the western end of the Marmara Sea. To clear these conditions, OBS specifications we need are high dynamic range and low instrument noise to observe micro seismicity, low electrical consumption to realize long term observation of over one year, high cost performance to cover the broad area for OBS installation, low cost implementation, and good operability to treat by relatively small number of persons. All items, which are three components velocity sensor, batteries, a recorder, a GPS receiver, a transponder and its transducer to control OBS retrieval, a flasher and a beacon, are installed in the 17 inches glass sphere. The natural frequency of the velocity sensor is 4.5 Hz and the frequency range of our OBS is from 4.5 Hz to 250 Hz. Data sampling is selectable among 100 Hz, 250 Hz and 500 Hz. Because our OBS is deployed by free fall, accuracy of the OBS clock is essentially one of important factors, and it is less than 0.1 ppm. And the resolution of A/D conversion performed on the recorder is 24 bit and we keep the dynamic range of over 135 dB. These data is stored on a semiconductor memory and the capacity is over

X-Ray Emission from Massive Stars in Cyg OB2

NASA Astrophysics Data System (ADS)

Rauw, G.; Nazé, Y.; Wright, N. J.; Drake, J. J.; Guarcello, M. G.; Prinja, R. K.; Peck, L. W.; Albacete Colombo, J. F.; Herrero, A.; Kobulnicky, H. A.; Sciortino, S.; Vink, J. S.

2015-11-01

We report on the analysis of the Chandra-ACIS data of O, B, and WR stars in the young association Cyg OB2. X-ray spectra of 49 O-stars, 54 B-stars, and 3 WR-stars are analyzed and for the brighter sources, the epoch dependence of the X-ray fluxes is investigated. The O-stars in Cyg OB2 follow a well-defined scaling relation between their X-ray and bolometric luminosities: {log}\\\\frac{{L}{{X}}}{{L}{bol}}=-7.2+/- 0.2. This relation is in excellent agreement with the one previously derived for the Carina OB1 association. Except for the brightest O-star binaries, there is no general X-ray overluminosity due to colliding winds in O-star binaries. Roughly half of the known B-stars in the surveyed field are detected, but they fail to display a clear relationship between LX and Lbol. Out of the three WR stars in Cyg OB2, probably only WR 144 is itself responsible for the observed level of X-ray emission, at a very low {log}\\\\frac{{L}{{X}}}{{L}{bol}}=-8.8+/- 0.2. The X-ray emission of the other two WR-stars (WR 145 and 146) is most probably due to their O-type companion along with a moderate contribution from a wind-wind interaction zone.

Fire Impact on Surface Fuels and Carbon Emissions in Scots pine Logged Sites of Siberia

NASA Astrophysics Data System (ADS)

Ivanova, G. A.; Kukavskaya, E. A.; Bogorodskaya, A. V.; Ivanov, V. A.; Zhila, S. V.; Conard, S. G.

2012-04-01

Forest fire and large-scale forest harvesting are the two major disturbances in the Russian boreal forests. Non-recovered logged sites total about a million hectares. Logged sites are characterized by higher fire hazard than forest sites due great amounts of logging slash, which dries out much more rapidly compared to understory fuels. Moreover, most logging sites can be easily accessed by local population. Both legal and illegal logging are also increasing rapidly in many forest areas of Siberia. Fire effects on forest overstory, subcanopy woody layer, and ground vegetation biomass were estimated on logged vs. unlogged sites in the Central Siberia region in 2009-2012 as a part of the project "The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia" supported by NASA (NEESPI). Dead down woody fuels are significantly less at unburned/logged area of dry southern regions compared to more humid northern regions. Fuel consumption was typically less in spring fires than during summer fires. Fire-caused carbon emissions on logged sites appeared to be twice that on unlogged sites. Soil respiration is less at logged areas compared to undisturbed forest. After fire soil respiration decreases both at logged and unlogged areas. arbon emissions from fire and post-fire ecosystem damage on logged sites are expected to increase under changing climate conditions and as a result of anticipated increases in future forest harvesting in Siberia.

Modern nature and climate changes in Siberia: new methods and results of analysis of instrumented observations

NASA Astrophysics Data System (ADS)

Kabanov, Mikhail V.

2002-02-01

Peculiarity of nature and climate changes in middle latitudes of the Northern Hemisphere and in Siberia is that the temporal variability of meteorological quantities here has a wide range and their spatial variability has a complicated zone structure. Therefore, regional monitoring of modern nature and climate changes in Siberia is of scientific interest from the viewpoint of the global changes observed. Another Siberian peculiarity is associated with the fact that there are many unique objects that have global importance both as natural complexes (boreal forests, water- bog systems, Baikal lake, etc.) And as technogenic objects (oil and gas production, coal mining, metallurgy, transport, etc.). Therefore monitoring and modeling of regional nature and climate changes in Siberia have great practical importance, which is underestimated now, for industrial development of Siberia. Taking into account the above peculiarities and tendencies on investigation of global and regional environmental and climate changes, the multidisciplinary project on Climate and Ecological Monitoring of Siberia (CEMS) was accepted to the research and development program Sibir' since 1993. To realize this project, the Climate and Ecological Observatory was established in Tomsk at the Institute for Optical Monitoring (IOM) SB RAS. At the present time the stations (the basic and background ones) of this observatory are in a progress and theory and instruments for monitoring are being developed as well. In this paper we discuss some results obtained in the framework of CEMS project that were partially published in the monographs, in scientific journals, and will be published in the Proceedings of the 8th Joint International Symposium on Atmospheric and Ocean Optics and Atmosphere Physics. This review has a purpose not only to discuss the obtained regularities but also to formulate scientific and technical tasks for further investigations into the regional changes of technogenic, natural, and

Modelling Climate/Global Change and Assessing Environmental Risks for Siberia

NASA Astrophysics Data System (ADS)

Lykosov, V. N.; Kabanov, M. V.; Heimann, M.; Gordov, E. P.

2009-04-01

The state-of-the-art climate models are based on a combined atmosphere-ocean general circulation model. A central direction of their development is associated with an increasingly accurate description of all physical processes participating in climate formation. In modeling global climate, it is necessary to reconstruct seasonal and monthly mean values, seasonal variability (monsoon cycle, parameters of storm-tracks, etc.), climatic variability (its dominating modes, such as El Niño or Arctic Oscillation), etc. At the same time, it is quite urgent now to use modern mathematical models in studying regional climate and ecological peculiarities, in particular, that of Northern Eurasia. It is related with the fact that, according to modern ideas, natural environment in mid- and high latitudes of the Northern hemisphere is most sensitive to the observed global climate changes. One should consider such tasks of modeling regional climate as detailed reconstruction of its characteristics, investigation of the peculiarities of hydrological cycle, estimation of the possibility of extreme phenomena to occur, and investigation of the consequences of the regional climate changes for the environment and socio-economic relations as its basic tasks. Changes in nature and climate in Siberia are of special interest in view of the global change in the Earth system. The vast continental territory of Siberia is undoubtedly a ponderable natural territorial region of Eurasian continent, which is characterized by the various combinations of climate-forming factors. Forests, water, and wetland areas are situated on a significant part of Siberia. They play planetary important regulating role due to the processes of emission and accumulation of the main greenhouse gases (carbon dioxide, methane, etc.). Evidence of the enhanced rates of the warming observed in the region and the consequences of such warming for natural environment are undoubtedly important reason for integrated regional

Unified study of Quality of Service (QoS) in OPS/OBS networks

NASA Astrophysics Data System (ADS)

Hailu, Dawit Hadush; Lema, Gebrehiwet Gebrekrstos; Yekun, Ephrem Admasu; Kebede, Samrawit Haylu

2017-07-01

With the growth of Internet traffic, an inevitable use of optical networks provide a large bandwidth, fast data transmission rates and Quality of Service (QoS) support. Currently, Optical Burst Switched (OBS)/Optical Packet Switched (OPS) networks are under study as future solutions for addressing the increase demand of Internet traffic. However, due to their high blocking probability in the intermediate nodes they have been delayed in the industries. Packet loss in OBS/OPS networks is mainly occur due to contention. Hence, the contribution of this study is to analyze the file loss ratio (FLR), packet overhead and number of disjoint paths, and processing delay over Coded Packet Transport (CPT) scheme for OBS/OPS network using simulation. The simulations show that CPT scheme reduces the FLR in OBS/OPS network for the evaluated scenarios since the data packets are chopped off into blocks of the data packet for transmission over a network. Simulation results for secrecy and survivability are verified with the help of the analytical model to define the operational range of CPT scheme.

Limits of pastoral adaptation to permafrost regions caused by climate change among the Sakha people in the middle basin of Lena River

NASA Astrophysics Data System (ADS)

Takakura, Hiroki

2016-09-01

This article focuses on the pastoral practices of the Sakha people in eastern Siberia to explore the impact of climate change on human livelihood in permafrost regions. Sakha use grassland resources in river terraces and the alaas thermokarst landscape for cattle-horse husbandry. Although they practice a different form of subsistence than other indigenous arctic peoples, such as hunter - gatherers or reindeer herders, the adaptation of Sakha has been relatively resilient in the past 600-800 years. Recent climate change, however, could change this situation. According to hydrologists, increased precipitation is now observed in eastern Siberia, which has resulted in the increase of permafrost thawing, causing forests to die. Moreover, local meteorologists report an increase of flooding in local rivers. How do these changes affect the local pastoral adaptation? While describing recent uses of grassland resource by local people, and their perception of climate change through anthropological field research, I investigated the subtle characteristics of human-environment interactions in pastoral adaptation, in order to identify the limits of adaptation in the face of climate change.

Views of American OB/GYNs on the ethics of prenatal whole-genome sequencing.

PubMed

Bayefsky, Michelle J; White, Amina; Wakim, Paul; Hull, Sara Chandros; Wasserman, David; Chen, Stephanie; Berkman, Benjamin E

2016-12-01

Given public demand for genetic information, the potential to perform prenatal whole-genome sequencing (PWGS) non-invasively in the future, and decreasing costs of whole-genome sequencing, it is likely that OB/GYN practice will include PWGS. The goal of this project was to explore OB/GYNs' views on the ethical issues surrounding PWGS and their preparedness for counseling patients on its use. A national survey was administered to 2500 members of American Congress of Obstetricians and Gynecologists. A total of 1114 respondents completed the survey (response rate = 45%). OB/GYNs are most concerned with ordering non-medical fetal genetic information, are worried about increasing parental anxiety, and feel it is appropriate to be directive when counseling parents about PWGS. Furthermore, most OB/GYNs have limited knowledge of genetics, rely heavily on genetic counselors and would like more guidance regarding the clinical adoption of PWGS. OB/GYNs do not completely accept or reject PWGS, but a substantial number have significant ethical and practical concerns. They are most concerned with issues that will directly affect their practices and interactions with patients, such as increasing parental anxiety and costs of care. Professional guidance would be instrumental in directing the adoption of PWGS and alleviating the ethical burden posed by PWGS on individual OB/GYNs. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

The Overt Behaviour Scale-Self-Report (OBS-SR) for acquired brain injury: exploratory analysis of reliability and validity.

PubMed

Kelly, Glenn; Simpson, Grahame K; Brown, Suzanne; Kremer, Peter; Gillett, Lauren

2017-05-23

The objectives were to test the properties, via a psychometric study, of the Overt Behaviour Scale-Self-Report (OBS-SR), a version of the OBS-Adult Scale developed to provide a client perspective on challenging behaviours after acquired brain injury. Study sample 1 consisted of 37 patients with primary brain tumour (PBT) and a family-member informant. Sample 2 consisted of 34 clients with other acquired brain injury (mixed brain injury, MBI) and a service-provider informant. Participants completed the OBS-SR (at two time points), and the Awareness Questionnaire (AQ) and Mayo Portland Adaptability Inventory-III (MPAI-III) once; informants completed the OBS-Adult and AQ once only. PBT-informant dyads displayed "good" levels of agreement (ICC 2,k  = .74; OBS-SR global index). Although MBI-informant dyads displayed no agreement (ICC 2,k  = .22; OBS-SR global index), the sub-group (17/29) rated by clinicians as having moderate to good levels of awareness displayed "fair" agreement (ICC 2,k  = .58; OBS-SR global index). Convergent/divergent validity was demonstrated by significant correlations between OBS-SR subscales and MPAI-III subscales with behavioural content (coefficients in the range .36 -.61). Scores had good reliability across one week (ICC 2,k  = .69). The OBS-SR took approximately 15 minutes to complete. It was concluded that the OBS-SR demonstrated acceptable reliability and validity, providing a useful resource in understanding clients' perspectives about their behaviour.

Search for OB stars running away from young star clusters. I. NGC 6611

NASA Astrophysics Data System (ADS)

Gvaramadze, V. V.; Bomans, D. J.

2008-11-01

N-body simulations have shown that the dynamical decay of the young (~1 Myr) Orion Nebula cluster could be responsible for the loss of at least half of its initial content of OB stars. This result suggests that other young stellar systems could also lose a significant fraction of their massive stars at the very beginning of their evolution. To confirm this expectation, we used the Mid-Infrared Galactic Plane Survey (completed by the Midcourse Space Experiment satellite) to search for bow shocks around a number of young (⪉several Myr) clusters and OB associations. We discovered dozens of bow shocks generated by OB stars running away from these stellar systems, supporting the idea of significant dynamical loss of OB stars. In this paper, we report the discovery of three bow shocks produced by O-type stars ejected from the open cluster NGC 6611 (M16). One of the bow shocks is associated with the O9.5Iab star HD165319, which was suggested to be one of “the best examples for isolated Galactic high-mass star formation” (de Wit et al. 2005, A&A, 437, 247). Possible implications of our results for the origin of field OB stars are discussed.

CYP2C19 polymorphism frequency in Russian patients in Central Russia and Siberia with acute coronary syndrome

PubMed Central

Mirzaev, Karin B; Zelenskaya, Elena M; Barbarash, Olga L; Ganyukov, Vladimir I; Apartsin, Konstantin A; Saraeva, Natalya O; Nikolaev, Konstantin Y; Ryzhikova, Kristina A; Lifshits, Galina I; Sychev, Dmitry A

2017-01-01

Purpose The aim of this study is to investigate the frequency of CYP2C19*2, *3 allelic variants, associated with poor response to clopidogrel, and CYP2C19*17, associated with excessive response to clopidogrel, in patients with acute coronary syndrome (ACS) from Siberia and Moscow regions of Russia. Patients and methods The study included 512 ACS patients who were subsequently treated with coronary arterial stenting. The subjects assigned were from the cities of Central (Novosibirsk, Kemerovo), Eastern (Irkutsk), Northern (Surgut) Siberia regions and from Moscow region. The mean age of patients enrolled was 63.9±10.9 years. Among the assigned subjects, the proportion of men accounted for 80% and women 20%. Results According to the results obtained in the present study, from 16% up to 27.5% of patients in different regions of Russia have at least one CYP2C19 “poor metabolizer” (PM) allele variant affecting clopidogrel metabolism and, therefore, suppressing its antiplatelet activity. CYP2C19*17 allele variant was identified with the frequency of 15.4% up to 33.3%. The study revealed the presence of statistically significant differences in CYP2C19*3 allele frequency between the Russian ethnic group patients from Eastern and Central Siberia (p=0.001; odds ratio=1.05 [95% confidence interval 1.01–1.09]). Conclusion The study revealed statistically significant differences between the allele frequencies in Eastern and Central Siberia, which can probably be caused by a considerable number of Buryats inhabiting Eastern Siberia. PMID:28442925

The Est3 protein associates with yeast telomerase through an OB-fold domain

PubMed Central

Lee, Jaesung S.; Mandell, Edward K.; Tucey, Timothy M.; Morris, Danna K.; Victoria, Lundblad

2009-01-01

The Est3 protein is a small regulatory subunit of yeast telomerase which is dispensable for enzyme catalysis but essential for telomere replication in vivo. Using structure prediction combined with in vivo characterization, we show here that Est3 consists of a predicted OB (oligo-saccharide/oligo-nucleotide binding) fold. Mutagenesis of predicted surface residues was used to generate a functional map of one surface of Est3, which identified a site that mediates association with the telomerase complex. Surprisingly, the predicted OB-fold of Est3 is structurally similar to the OB-fold of the mammalian TPP1 protein, despite the fact that Est3 and TPP1, as components of telomerase and a telomere capping complex, respectively, perform functionally distinct tasks at chromosome ends. The analysis performed on Est3 may be instructive in generating comparable missense mutations on the surface of the OB-fold domain of TPP1. PMID:19172754

Occurrence and genetic variability of Kemerovo virus in Ixodes ticks from different regions of Western Siberia, Russia and Kazakhstan.

PubMed

Tkachev, Sergey E; Tikunov, Artem Yu; Babkin, Igor V; Livanova, Natalia N; Livanov, Stanislav G; Panov, Victor V; Yakimenko, Valeriy V; Tantsev, Alexey K; Taranenko, Dmitrii E; Tikunova, Nina V

2017-01-01

Kemerovo virus (KEMV), a member of the Reoviridae family, Orbivirus genus, is transmitted by Ixodes ticks and can cause aseptic meningitis and meningoencephalitis. Recently, this virus was observed in certain provinces of European part of Russia, Ural, and Western and Eastern Siberia. However, the occurrence and genetic diversity of KEMV in Western Siberia remain poorly studied. Therefore, the aim of this work was to investigate the prevalence and genetic variability of KEMV in Ixodes ticks from Western Siberia. A total of 1958 Ixodes persulcatus, I. pavlovskyi ticks and their hybrids from Novosibirsk and Omsk provinces, Altai Republic (Russia) and East Kazakhstan province (Kazakhstan) were analyzed for the presence of KEMV and tick-borne encephalitis virus (TBEV) RNA. It was observed that the KEMV distribution area in Western Siberia was wider than originally thought and included Northern and Northeastern Altai in addition to the Omsk and Novosibirsk provinces. For the first time, this virus was found in Kazakhstan. The occurrence of KEMV was statistically lower than TBEV in most locations in Western Siberia. KEMV was found both in I. persulcatus and I. pavlovskyi ticks and in their hybrids. Notably, KEMV variants observed in the 2010s were genetically different from those isolated in the 1960s, which indicated the ongoing process of evolution of the Kemerovo virus group. Moreover, the possibility of reassortment for KEMV was demonstrated for the first time. Copyright © 2016 Elsevier B.V. All rights reserved.

An All-Optical Access Metro Interface for Hybrid WDM/TDM PON Based on OBS

NASA Astrophysics Data System (ADS)

Segarra, Josep; Sales, Vicent; Prat, Josep

2007-04-01

A new all-optical access metro network interface based on optical burst switching (OBS) is proposed. A hybrid wavelength-division multiplexing/time-division multiplexing (WDM/TDM) access architecture with reflective optical network units (ONUs), an arrayed-waveguide-grating outside plant, and a tunable laser stack at the optical line terminal (OLT) is presented as a solution for the passive optical network. By means of OBS and a dynamic bandwidth allocation (DBA) protocol, which polls the ONUs, the available access bandwidth is managed. All the network intelligence and costly equipment is located at the OLT, where the DBA module is centrally implemented, providing quality of service (QoS). To scale this access network, an optical cross connect (OXC) is then used to attain a large number of ONUs by the same OLT. The hybrid WDM/TDM structure is also extended toward the metropolitan area network (MAN) by introducing the concept of OBS multiplexer (OBS-M). The network element OBS-M bridges the MAN and access networks by offering all-optical cross connection, wavelength conversion, and data signaling. The proposed innovative OBS-M node yields a full optical data network, interfacing access and metro with a geographically distributed access control. The resulting novel access metro architectures are nonblocking and, with an improved signaling, provide QoS, scalability, and very low latency. Finally, numerical analysis and simulations demonstrate the traffic performance of the proposed access scheme and all-optical access metro interface and architectures.

Peatland classification of West Siberia based on Landsat imagery

NASA Astrophysics Data System (ADS)

Terentieva, I.; Glagolev, M.; Lapshina, E.; Maksyutov, S. S.

2014-12-01

Increasing interest in peatlands for prediction of environmental changes requires an understanding of its geographical distribution. West Siberia Plain is the biggest peatland area in Eurasia and is situated in the high latitudes experiencing enhanced rate of climate change. West Siberian taiga mires are important globally, accounting for about 12.5% of the global wetland area. A number of peatland maps of the West Siberia was developed in 1970s, but their accuracy is limited. Here we report the effort in mapping West Siberian peatlands using 30 m resolution Landsat imagery. As a first step, peatland classification scheme oriented on environmental parameter upscaling was developed. The overall workflow involves data pre-processing, training data collection, image classification on a scene-by-scene basis, regrouping of the derived classes into final peatland types and accuracy assessment. To avoid misclassification peatlands were distinguished from other landscapes using threshold method: for each scene, Green-Red Vegetation Indices was used for peatland masking and 5th channel was used for masking water bodies. Peatland image masks were made in Quantum GIS, filtered in MATLAB and then classified in Multispec (Purdue Research Foundation) using maximum likelihood algorithm of supervised classification method. Training sample selection was mostly based on spectral signatures due to limited ancillary and high-resolution image data. As an additional source of information, we applied our field knowledge resulting from more than 10 years of fieldwork in West Siberia summarized in an extensive dataset of botanical relevés, field photos, pH and electrical conductivity data from 40 test sites. After the classification procedure, discriminated spectral classes were generalized into 12 peatland types. Overall accuracy assessment was based on 439 randomly assigned test sites showing final map accuracy was 80%. Total peatland area was estimated at 73.0 Mha. Various ridge

Analysis of Terrestrial Carbon Stocks in a Small Catchment of Northeastern Siberia

NASA Astrophysics Data System (ADS)

Heard, K.; Natali, S.; Bunn, A. G.; Loranty, M. M.; Kholodov, A. L.; Schade, J. D.; Berner, L. T.; Spektor, V.; Zimov, N.; Alexander, H. D.

2015-12-01

As arctic terrestrial ecosystems comprise about one-third of the global terrestrial ecosystem carbon total, understanding arctic carbon cycling and the feedback of terrestrial carbon pools to accelerated warming is an issue of global concern. For this research, we examined above- and belowground carbon stocks in a larch-dominated catchment underlain by yedoma and located within the Kolyma River watershed in northeastern Siberia. We quantified carbon stocks in vegetation, active layer, and permafrost, and we assessed the correlation between plant and active layer carbon pools and four environmental correlates — slope, solar insolation, canopy density, and leaf area index ­— at 20 sites. Carbon in the active layer was approximately four times greater than aboveground carbon pools (972 g C m-2), and belowground carbon to 1 m depth was approximately 18 times greater than aboveground carbon pools. Canopy density and slope had a robust positive association with aboveground carbon pools, and soil moisture was positively related to %C in organic, thawed mineral and permafrost soil. Thaw depth was negatively correlated with moss cover and larch biomass, highlighting the importance of vegetation and surface characteristics on permafrost carbon vulnerability. These data suggest that landscape and ecosystem characteristics affect carbon accumulation and storage, but they also play an important role in stabilizing permafrost carbon pools.

ObsPy: A Python Toolbox for Seismology - Recent Developments and Applications

NASA Astrophysics Data System (ADS)

Megies, T.; Krischer, L.; Barsch, R.; Sales de Andrade, E.; Beyreuther, M.

2014-12-01

ObsPy (http://www.obspy.org) is a community-driven, open-source project dedicated to building a bridge for seismology into the scientific Python ecosystem. It offersa) read and write support for essentially all commonly used waveform, station, and event metadata file formats with a unified interface,b) a comprehensive signal processing toolbox tuned to the needs of seismologists,c) integrated access to all large data centers, web services and databases, andd) convenient wrappers to legacy codes like libtau and evalresp.Python, currently the most popular language for teaching introductory computer science courses at top-ranked U.S. departments, is a full-blown programming language with the flexibility of an interactive scripting language. Its extensive standard library and large variety of freely available high quality scientific modules cover most needs in developing scientific processing workflows. Together with packages like NumPy, SciPy, Matplotlib, IPython, Pandas, lxml, and PyQt, ObsPy enables the construction of complete workflows in Python. These vary from reading locally stored data or requesting data from one or more different data centers through to signal analysis and data processing and on to visualizations in GUI and web applications, output of modified/derived data and the creation of publication-quality figures.ObsPy enjoys a large world-wide rate of adoption in the community. Applications successfully using it include time-dependent and rotational seismology, big data processing, event relocations, and synthetic studies about attenuation kernels and full-waveform inversions to name a few examples. All functionality is extensively documented and the ObsPy tutorial and gallery give a good impression of the wide range of possible use cases.We will present the basic features of ObsPy, new developments and applications, and a roadmap for the near future and discuss the sustainability of our open-source development model.

Timber Volume and Biomass Estimates in Central Siberia from Satellite Data

NASA Technical Reports Server (NTRS)

Ranson, K. Jon; Kimes, Daniel S.; Kharuk, Vyetcheslav I.

2007-01-01

Mapping of boreal forest's type, structure parameters and biomass are critical for understanding the boreal forest's significance in the carbon cycle, its response to and impact on global climate change. The biggest deficiency of the existing ground based forest inventories is the uncertainty in the inventory data, particularly in remote areas of Siberia where sampling is sparse, lacking, and often decades old. Remote sensing methods can help overcome these problems. In this joint US and Russian study, we used the moderate resolution imaging spectroradiometer (MODIS) and unique waveform data of the geoscience laser altimeter system (GLAS) and produced a map of timber volume for a 10degx12deg area in Central Siberia. Using these methods, the mean timber volume for the forested area in the total study area was 203 m3/ ha. The new remote sensing methods used in this study provide a truly independent estimate of forest structure, which is not dependent on traditional ground forest inventory methods.

High rate of vaginal erosions associated with the mentor ObTape.

PubMed

Yamada, Brian S; Govier, Fred E; Stefanovic, Ksenija B; Kobashi, Kathleen C

2006-08-01

The transobturator tape method is a newer surgical technique for the treatment of stress urinary incontinence. Limited data exist related to complications with this approach or the types of mesh products used. We report our experience with vaginal erosions associated with the Mentor ObTape and American Medical Systems Monarc transobturator slings. Beginning in December 2003 selected female patients with anatomic urinary incontinence were prospectively followed after placement of the Mentor ObTape. Beginning in January 2004 we also began using the American Medical Systems Monarc in similar patients. Patients were admitted overnight after surgery, discharged on oral antibiotics, and seen in the clinic at 6 weeks postoperatively. A total of 67 patients have undergone placement of the Mentor ObTape and 9 of those patients (13.4%) have had vaginal extrusions of the sling. Eight patients reported a history of persistent vaginal discharge. One patient presented initially to an outside facility with a left thigh abscess tracking to the left inguinal incision site. Each patient was taken back to the operating room for mesh removal. A total of 56 patients have undergone placement of the AMS Monarc and none have had any vaginal erosions. Our high rate of vaginal extrusion using the ObTape has led us to discontinue the use of this product in our institution. Continued followup of all of these patients will be of critical importance.

Interferometric imaging of crustal structure from wide-angle multicomponent OBS-airgun data

NASA Astrophysics Data System (ADS)

Shiraishi, K.; Fujie, G.; Sato, T.; Abe, S.; Asakawa, E.; Kodaira, S.

2015-12-01

In wide-angle seismic surveys with ocean bottom seismograph (OBS) and airgun, surface-related multiple reflections and upgoing P-to-S conversions are frequently observed. We applied two interferometric imaging methods to the multicomponent OBS data in order to highly utilize seismic signals for subsurface imaging.First, seismic interferometry (SI) is applied to vertical component in order to obtain reflection profile with multiple reflections. By correlating seismic traces on common receiver records, pseudo seismic data are generated with virtual sources and receivers located on all original shot positions. We adopt the deconvolution SI because source and receiver spectra can be canceled by spectral division. Consequently, gapless reflection images from just below the seafloor to the deeper are obtained.Second, receiver function (RF) imaging is applied to multicomponent OBS data in order to image P-to-S conversion boundary. Though RF is commonly applied to teleseismic data, our purpose is to extract upgoing PS converted waves from wide-angle OBS data. The RF traces are synthesized by deconvolution of radial and vertical components at same OBS location for each shot. Final section obtained by stacking RF traces shows the PS conversion boundaries beneath OBSs. Then, Vp/Vs ratio can be estimated by comparing one-way traveltime delay with two-way traveltime of P wave reflections.We applied these methods to field data sets; (a) 175 km survey in Nankai trough subduction zone using 71 OBSs with from 1 km to 10 km intervals and 878 shots with 200 m interval, and (b) 237 km survey in northwest pacific ocean with almost flat layers before subduction using 25 OBSs with 6km interval and 1188 shots with 200 m interval. In our study, SI imaging with multiple reflections is highly applicable to OBS data even in a complex geological setting, and PS conversion boundary is well imaged by RF imaging and Vp/Vs ratio distribution in sediment is estimated in case of simple structure.

Experimental demonstration of OSPF-TE extensions in muiti-domain OBS networks connected by GMPLS network

NASA Astrophysics Data System (ADS)

Tian, Chunlei; Yin, Yawei; Wu, Jian; Lin, Jintong

2008-11-01

The interworking network of Generalized Multi-Protocol Label Switching (GMPLS) and Optical Burst Switching (OBS) is attractive network architecture for the future IP/DWDM network nowadays. In this paper, OSPF-TE extensions for multi-domain Optical Burst Switching networks connected by GMPLS controlled WDM network are proposed, the corresponding experimental results such as the advertising latency are also presented by using an OBS network testbed. The experimental results show that it works effectively on the OBS/GMPLS networks.

Mapping wetland and forest landscapes in Siberia with Landsat data

NASA Astrophysics Data System (ADS)

Maksyutov, Shamil; Kleptsova, Irina; Glagolev, Mikhail; Sedykh, Vladimir; Kuzmenko, Ekaterina; Silaev, Anton; Frolov, Alexander; Nikolaeva, Svetlana; Fedorov, Alexander

2014-05-01

Landsat data availability provides opportunity for improving the knowledge of the Siberian ecosystems necessary for quantifying the response of the regional carbon cycle to the climate change. We developed a new wetland map based on Landsat data for whole West Siberia aiming at scaling up the methane emission observations. Mid-summer Landsat scenes were used in supervised classification method, based on ground truth data obtained during multiple field surveys. The method allows distinguishing following wetland types: pine-dwarf shrubs-sphagnum bogs or ryams, ridge-hollows complexes, shallow-water complexes, sedge-sphagnum poor fens, herbaceous-sphagnum poor fens, sedge-(moss) poor fens and fens, wooded swamps or sogra, palsa complexes. In our estimates wetlands cover 36% of the taiga area. Total methane emission from WS taiga mires is estimated as 3.6 TgC/yr,which is 77% larger as compared to the earlier estimate based on partial Landsat mapping combined with low resolution map due to higher fraction of fen area. We make an attempt to develop a forest typology system useful for a dynamic vegetation modeling and apply it to the analysis of the forest type distribution for several test areas in West and East Siberia, aiming at capability of mapping whole Siberian forests based on Landsat data. Test region locations are: two in West Siberian middle taiga (Laryegan and Nyagan), and one in East Siberia near Yakutsk. The ground truth data are based on analysis of the field survey, forest inventory data from the point of view of the successional forest type classification. Supervised classification was applied to the areas where ample ground truth and inventory data are available, using several limited area maps and vegetation survey. In Laryegan basin the upland forest areas are dominated (as climax forest species) by Scots pine on sandy soils and Siberian pine with presence of fir and spruce on the others. Those types are separable using Landsat spectral data alone. In

VizieR Online Data Catalog: OB association members in ACT+TRC Catalogs (Hoogerwerf, 2000)

NASA Astrophysics Data System (ADS)

Hoogerwerf, R.

2000-05-01

The Hipparcos Catalogue (Cat. I/239) contains members of nearby OB associations brighter than 12th magnitude in V. However, membership lists are complete only to magnitude V=7.3. In this paper we discuss whether proper motions listed in the `Astrographic Catalogue+Tycho' reference catalogue (ACT, Cat. I/246) and the Tycho Reference Catalogue (TRC, Cat. I/250), which are complete to V~10.5mag, can be used to find additional association members. Proper motions in the ACT/TRC have an average accuracy of ~3mas/yr. We search for ACT/TRC stars which have proper motions consistent with the spatial velocity of the Hipparcos members of the nearby OB associations already identified by de Zeeuw et al. (1999, Cat. J/AJ/117/354). These stars are first selected using a convergent-point method, and then subjected to further constraints on the proper-motion distribution, magnitude and colour to narrow down the final number of candidate members. Monte Carlo simulations show that the proper-motion distribution, magnitude, and colour constraints remove ~97% of the field stars, while at the same time retain more than 90% of the cluster stars. The procedure has been applied to five nearby associations: the three subgroups of Sco OB2, plus Per OB3 and Cep OB6. In all cases except Cep OB6, we find evidence for new association members fainter than the completeness limit of the Hipparcos Catalogue. However, narrow-band photometry and/or radial velocities are needed to pinpoint the cluster members, and to study their physical characteristics. (1 data file).

Temporal and Spatial Wildfire Dynamics of Northern Siberia: Larch Forests and Insect Outbreak Areas

NASA Astrophysics Data System (ADS)

Kharuk, Viacheslav; Antamoshkina, Olga; Ponomarev, Eugene

2017-04-01

Wildfire number and burned area temporal dynamics within all of Siberia and along a south-north transect in central Siberia (45 - 73°N) were studied based on NOAA/AVHRR and Terra/MODIS data and field measurements for the period since 1996. In addition, fire return interval along the south-north transect was analyzed. Third, pest outbreak (Siberian silkmoth) impact on the wildfires was studied. Both, number of forest fires and burned area in Siberia increased during recent decades. Significant correlations were found between forest fires, burned areas and air temperature (r = 0.5) and drought 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 (66°33'N), and to about 300 years near the northern limit of closed forest stands ( 71+°N). That increase was negatively correlated with incoming solar radiation (r = -0.95). Siberian silkmoth outbreaks leads to an order of magnitude increase in burned area and fire frequency. Multiple fires turns former "dark needle conifer" taiga into grass and bush communities for decades.

Paleoenvironmental dynamics of Western Beringia - New studies from the Yedoma key site Duvanny Yar (Lower Kolyma River, Siberia)

NASA Astrophysics Data System (ADS)

Strauss, Jens; Schirrmeister, Lutz; Wetterich, Sebastian

2010-05-01

Duvanny Yar is a stratigraphic key site for the late Quaternary in Western Beringia. It is characteristic for ice-rich permafrost sequences of the so-called Yedoma Suite in north-east Siberia (e.g. KAPLINA et al. 1978; SHER et al. 1979) and is an important reference site for the late Pleistocene history of Beringia (HOPKINS 1982). The aim of our study was to reconstruct the paleoenvironmental dynamics at the Duvanny Yar site during the late Quaternary using its terrestrial archive. A multidisciplinary approach using geocryological, geochronological, sedimentological, hydrochemical, isotope geochemical, and paleoecological methods was applied to obtain multiproxy records. Sediment samples were analysed for ice contents, grain size parameters, biogeochemistry (total carbon, total organic carbon, total nitrogen, stable carbon isotopes), mineral density, mass specific magnetic susceptibility, and for radiocarbon age. Stable isotopes of water were measured for ground ice (ice wedges, segregated ice, and pore ice), modern surface waters and modern precipitation. Six profiles along the riverbank were sampled in August 2008. They contained Eemian lacustrine deposits, long sequences of Ice Complex deposits of the Late Pleistocene Yedoma, Holocene lacustrine and boggy deposits in thermokarst depressions. All profiles showed very bad sorted sediment of fine to coarse silt. A homogenous and polymodal grain size distribution for the ice rich (~30 to 60 wt %) Yedoma Suite revealed a polygenetic origin and disproves the pure "arctic loess" hypothesis for these deposits. Measurements of bulk density, ice content and total organic carbon content (TOC) enable for a relative TOC content in Ice Complex deposits at Duvanny Yar. The mean value of organic carbon at Duvanny Yar is 16 ± 11 kg/m^3. Geochronological results based on 11 new AMS ages revealed that the Yedoma Suite was continuously formed from the end of the Middle Weichselian (~ 40000 years BP) and at least until the Late

Ecosystem resilience to abrupt late Quaternary change in continental southern Siberia

NASA Astrophysics Data System (ADS)

Harding, Poppy; Mackay, Anson; Bezrukova, Elena; Shchetnikov, Alexander

2017-04-01

Quaternary climate variability is dominated by long term orbital forcing along with abrupt sub-Milankovitch events on the scales of millennia to centuries, driven by internal feedback mechanisms, volcanic forcing and fluctuating solar activity. Although these are well documented in the North Atlantic region, their expression is poorly understood in Siberia, particularly in relation to abrupt climatic events. Siberia has the world's highest level of continentality offering an opportunity to study changes remote from oceanic influences and improving understanding of interactions between the Siberian High and other atmospheric systems including the Aleutian Low, Arctic oscillation and Icelandic Low1 and ENSO2. Understanding of palaeoenvironmental change in Siberia is essential due to the region's high sensitivity to climatic change, with warming rates considerably higher than the global average over the past 50 years3, triggering significant environmental changes, including permafrost degradation, shifts in the forest-steppe biome, increases in forest fires and warming of seasonally ice-covered lakes. Additionally, the region provides essential palaeoenvironmental context for early hominins, for example at globally important sites such as Denisova cave4, and megafauna extinctions5. This presentation outlines ongoing work at Lake Baunt, SE Siberia including: key quaternary climate forcings, the site and its regional context, the key methods and preliminary results. These include a dated record back to ˜30ka BP (based on multiple 14C dates and Bayesian age modelling), multiproxy indicators of palaeoproductivity (e.g. biogenic silica and diatom analyses) and lake mixing regimes (inferred from diatom analyses). Together these highlight several key Quaternary fluctuations potentially correlated to events recorded in Greenland Ice Cores (GS2, GS2.1, GI1, GS1), and these are considered against key Quaternary records including those from nearby Lake Baikal and Hulu Cave in

Genetic Relatedness of WNIN and WNIN/Ob with Major Rat Strains in Biomedical Research.

PubMed

Battula, Kiran Kumar; Nappanveettil, Giridharan; Nakanishi, Satoshi; Kuramoto, Takashi; Friedman, Jeffry M; Kalashikam, Rajender Rao

2015-06-01

WNIN (Wistar/NIN) is an inbred rat strain maintained at National Institute of Nutrition (NIN) for more than 90 years, and WNIN/Ob is an obese mutant originated from it. To determine their genetic relatedness with major rat strains in biomedical research, they were genotyped at various marker loci. The recently identified markers for albino and hooded mutations which clustered all the known albino rats into a single lineage also included WNIN and WNIN/Ob rats. Genotyping using microsatellite DNA markers and phylogenetic analysis with 49 different rat strains suggested that WNIN shares a common ancestor with many Wistar originated strains. Fst estimates and Fischer's exact test suggest that WNIN rats differed significantly from all other strains tested. WNIN/Ob though shows hyper-leptinemia, like Zucker fatty rat, did not share the Zucker fatty rat mutation. The above analyses suggest WNIN as a highly differentiated rat strain and WNIN/Ob a novel obese mutant evolved from it.

Flow-oriented dynamic assembly algorithm in TCP over OBS networks

NASA Astrophysics Data System (ADS)

Peng, Shuping; Li, Zhengbin; He, Yongqi; Xu, Anshi

2008-11-01

OBS is envisioned as a promising infrastructure for the next generation optical network, and TCP is likely to be the dominant transport protocol in the next generation network. Therefore, it is necessary to evaluate the performance of TCP over OBS networks. The assembly at the ingress edge nodes will impact the network performance. There have been several Fixed Assembly Period (FAP) algorithms proposed. However, the assembly period in FAP is fixed, and it can not be adjusted according to the network condition. Moreover, in FAP, the packets from different TCP sources are assembled into one burst. In that case, if such a burst is dropped, the TCP windows of the corresponding sources will shrink and the throughput will be reduced. In this paper, we introduced a flow-oriented Dynamic Assembly Period (DAP) algorithm for TCP over OBS networks. Through comparing the previous and current burst lengths, DAP can track the variation of TCP window, and update the assembly period dynamically for the next assembly. The performance of DAP is evaluated over a single TCP connection and multiple connections, respectively. The simulation results show that DAP performs better than FAP at almost the whole range of burst dropping probability.

Conditions and development case studies for mountainous deposits in Siberia

NASA Astrophysics Data System (ADS)

Talgamer, B. L.; Franchuk, A. V.

2017-10-01

The article contains the materials on deposits development intensification under challenging climatic and mining conditions, including mountainous areas of Siberia. The exploitation case studies for mountainous deposits all over the world and in Russia have been described. The authors have been set out the factors impeding the development of such deposits, and the extent of mining and transportation equipment performance degradation is also indicated. There have been stated the characteristics and the description of one of the newly mountainous gold ore deposits in Siberia which is being developed at an altitude of 2684m. A number of specific factors concerning its development have also been introduced as well as the description of mining technologies engineered by Irkutsk National Research Technical University (IRNRTU) specialists. The depth and principal dimensions of the open pit together with the mining and transportation equipment and facilities have been justified. The prime cost analysis of mineral extraction has been made, which results showed the substantial growth in expenditures for the transportation of the overburden rocks and ores. In view of the above mentioned research, there appeared the necessity for the search of new and the enhancement of current transport vehicles and communications.

Multi-Sensor Remote Sensing of Forest Dynamics in Central Siberia

NASA Technical Reports Server (NTRS)

Ransom, K. J.; Sun, G.; Kharuk, V. I.; Howl, J.

2011-01-01

The forested regions of Siberia, Russia are vast and contain about a quarter of the world's forests that have not experienced harvesting. However, many Siberian forests are facing twin pressures of rapidly changing climate and increasing timber harvest activity. Monitoring the dynamics and mapping the structural parameters of the forest is important for understanding the causes and consequences of changes observed in these areas. Because of the inaccessibility and large extent of this forest, remote sensing data can play an important role for observing forest state and change. In Central Siberia, multi-sensor remote sensing data have been used to monitor forest disturbances and to map above-ground biomass from the Sayan Mountains in the south to the taiga-tundra boundaries in the north. Radar images from the Shuttle Imaging Radar-C (SIR-C)/XSAR mission were used for forest biomass estimation in the Sayan Mountains. Radar images from the Japanese Earth Resources Satellite-1 (JERS-1), European Remote Sensing Satellite-1 (ERS-1) and Canada's RADARSAT-1, and data from ETM+ on-board Landsat-7 were used to characterize forest disturbances from logging, fire, and insect damage in Boguchany and Priangare areas.

Molar tooth structures in calcareous nodules, early Neoproterozoic Burovaya Formation, Turukhansk region, Siberia

NASA Astrophysics Data System (ADS)

Pope, Michael C.; Bartley, Julie K.; Knoll, Andrew H.; Petrov, Peter Yu.

2003-05-01

Molar tooth structures are abundant in large (1-2 m diameter) carbonate nodules within fine-grained, subtidal carbonates of the early Neoproterozoic (lower Upper Riphean) Burovaya Formation along the Sukhaya Tunguska River, Turukhansk Uplift, northwestern Siberia. Although molar tooth structures are regionally abundant in this unit, here they occur only within the nodules. Stable isotopic compositions of molar-tooth-filling dolomicrospar cements and of thinly bedded dolomicrite within and surrounding the nodules are indistinguishable from one another. The carbon isotopic compositions (mean δ13C=+2.8‰ PDB±0.4) reflect mean average oceanic surface water composition during their formation; the light oxygen isotopic compositions (mean δ18O=-6.4‰ PDB±2.2) are generally similar to those of other little-altered Meso- to Neoproterozoic limestones and dolostones. These molar tooth structures have no features that would support a tectonic origin; they more likely formed through bacterial processes. Carbonate cement filling of these voids occurred soon after their formation, but the mechanism responsible for this carbonate precipitation is currently uncertain. Local restriction of molar tooth structures to early diagenetic nodules suggests that penecontemporaneous lithification was required for the formation, or at least preservation, of these widespread Mesoproterozoic to Neoproterozoic features.

Diversity of mitochondrial DNA lineages in South Siberia.

PubMed

Derenko, M V; Grzybowski, T; Malyarchuk, B A; Dambueva, I K; Denisova, G A; Czarny, J; Dorzhu, C M; Kakpakov, V T; Miścicka-Sliwka, D; Woźniak, M; Zakharov, I A

2003-09-01

To investigate the origin and evolution of aboriginal populations of South Siberia, a comprehensive mitochondrial DNA (mtDNA) analysis (HVR1 sequencing combined with RFLP typing) of 480 individuals, representing seven Altaic-speaking populations (Altaians, Khakassians, Buryats, Sojots, Tuvinians, Todjins and Tofalars), was performed. Additionally, HVR2 sequence information was obtained for 110 Altaians, providing, in particular, some novel details of the East Asian mtDNA phylogeny. The total sample revealed 81% East Asian (M*, M7, M8, M9, M10, C, D, G, Z, A, B, F, N9a, Y) and 17% West Eurasian (H, U, J, T, I, N1a, X) matrilineal genetic contribution, but with regional differences within South Siberia. The highest influx of West Eurasian mtDNAs was observed in populations from the East Sayan and Altai regions (from 12.5% to 34.5%), whereas in populations from the Baikal region this contribution was markedly lower (less than 10%). The considerable substructure within South Siberian haplogroups B, F, and G, together with the high degree of haplogroup C and D diversity revealed there, allows us to conclude that South Siberians carry the genetic imprint of early-colonization phase of Eurasia. Statistical analyses revealed that South Siberian populations contain high levels of mtDNA diversity and high heterogeneity of mtDNA sequences among populations (Fst = 5.05%) that might be due to geography but not due to language and anthropological features.

ObsPy - A Python Toolbox for Seismology - and Applications

NASA Astrophysics Data System (ADS)

Krischer, L.; Megies, T.; Barsch, R.; MacCarthy, J.; Lecocq, T.; Koymans, M. R.; Carothers, L.; Eulenfeld, T.; Reyes, C. G.; Falco, N.; Sales de Andrade, E.

2017-12-01

Recent years witnessed the evolution of Python's ecosystem into one of the most powerful and productive scientific environments across disciplines. ObsPy (https://www.obspy.org) is a fully community driven, open-source project dedicated to provide a bridge for seismology into that ecosystem. It is a Python toolbox offering: Read and write support for essentially every commonly used data format in seismology with a unified interface and automatic format detection. This includes waveform data (MiniSEED, SAC, SEG-Y, Reftek, …) as well as station (SEED, StationXML, SC3ML, …) and event meta information (QuakeML, ZMAP, …). Integrated access to the largest data centers, web services, and real-time data streams (FDSNWS, ArcLink, SeedLink, ...). A powerful signal processing toolbox tuned to the specific needs of seismologists. Utility functionality like travel time calculations with the TauP method, geodetic functions, and data visualizations. ObsPy has been in constant development for more than eight years and is developed and used by scientists around the world with successful applications in all branches of seismology. Additionally it nowadays serves as the foundation for a large number of more specialized packages. Newest features include: Full interoperability of SEED and StationXML/Inventory objects Access to the Nominal Response Library (NRL) for easy and quick creation of station metadata from scratch Support for the IRIS Federated Catalog Service Improved performance of the EarthWorm client Several improvements to MiniSEED read/write module Improved plotting capabilities for PPSD (spectrograms, PSD of discrete frequencies over time, ..) Support for.. Reading ArcLink Inventory XML Reading Reftek data format Writing SeisComp3 ML (SC3ML) Writing StationTXT format This presentation will give a short overview of the capabilities of ObsPy and point out several representative or new use cases and show-case some projects that are based on ObsPy, e.g.: seismo

Photoionization of the diffuse interstellar medium and galactic halo by OB associtations

NASA Technical Reports Server (NTRS)

Dove, James B.; Shull, J. Michael

1994-01-01

Assuming smoothly varying H I distributions in te Galactic disk, we have calculated the geometry of diffuse II regions due to OB associations in the Galactic plane. Near the solar circle, OB associations with a Lyman continuum (Lyc) photon luminosity Psi(sub Lyc) = 3.3 x 10(exp 7) cm(exp -2) s(exp -1), produce H II regions that are density bounded in the vertical direction (H II chimneys) allowing Lyc to escape the gaseous disk and penetrate into the Galactic halo. We provide analytic formulae for the Lyc escape fraction as functions of S(sub 0) O-star catalog of Garmany and a new Lyc stellar stellar Lyc stellar flux calibration, we find a production rate of Lyc photons by OB associations within 2.5 kpc of Psi(sub Lyc) = 3.3 x 10(exp 7) cm(exp -2) s(exp -1). Integrating the fraction of Lyc photons that escape the disk over our adopted luminosity function of OB associations, we estimate that approximately 7% of the ionizing photons, or Phi(sub Lyc) = 2.3 x 10(exp 6) cm(exp -2) s(exp -1), escape each side of the H I disk layer and penetrate the diffuse ionized medium ('Reynolds layer'). This flux is sufficient to explain the potoionization of this, although we have not constructed a model for the observed H-alpha emission and pulsar dispersion measures that is fully consistent with the absorption rate of Lyc in the H II layer. Since our quiescent model does not account for the effects of dynamic chimneys and superbubbles, which should enhance Lyc escape, we conclude the O stars are the probable source of ionizing radiation for the Reynolds layer. For a random distribution of OB associations throughout the disk, the Lyc flux is nearly uniform for heights Z is greater than approximately 0.8 kpc above the midplane.

ObsPy: A Python toolbox for seismology - Sustainability, New Features, and Applications

NASA Astrophysics Data System (ADS)

Krischer, L.; Megies, T.; Sales de Andrade, E.; Barsch, R.; MacCarthy, J.

2016-12-01

ObsPy (https://www.obspy.org) is a community-driven, open-source project dedicated to offer a bridge for seismology into the scientific Python ecosystem. Amongst other things, it provides Read and write support for essentially every commonly used data format in seismology with a unified interface. This includes waveform data as well as station and event meta information. A signal processing toolbox tuned to the specific needs of seismologists. Integrated access to the largest data centers, web services, and databases. Wrappers around third party codes like libmseed and evalresp. Using ObsPy enables users to take advantage of the vast scientific ecosystem that has developed around Python. In contrast to many other programming languages and tools, Python is simple enough to enable an exploratory and interactive coding style desired by many scientists. At the same time it is a full-fledged programming language usable by software engineers to build complex and large programs. This combination makes it very suitable for use in seismology where research code often must be translated to stable and production ready environments, especially in the age of big data. ObsPy has seen constant development for more than six years and enjoys a large rate of adoption in the seismological community with thousands of users. Successful applications include time-dependent and rotational seismology, big data processing, event relocations, and synthetic studies about attenuation kernels and full-waveform inversions to name a few examples. Additionally it sparked the development of several more specialized packages slowly building a modern seismological ecosystem around it. We will present a short overview of the capabilities of ObsPy and point out several representative use cases and more specialized software built around ObsPy. Additionally we will discuss new and upcoming features, as well as the sustainability of open-source scientific software.

Possible detection of π^0^-decay γ-ray emission from CYG OB2 by EGRET.

NASA Astrophysics Data System (ADS)

Chen, W.; White, R. L.; Bertsch, D.

1996-12-01

We report possible detection of π^0^-decay radiation from Cyg OB2, a nearby (1.7kpc) massive OB star association. The EGRET flux (>100MeV) maps clearly indicate a point source whose error circle includes both Cyg OB2 and Cyg X-3. We show that Cyg X-3 is unlikely to be the counterpart for the EGRET source, because of the marginal spatial consistency and the lack of the 4.8-hour modulation seen in other high energy emissions from Cyg X-3. If confirmed, this will be the first detection by EGRET of massive stars.

Benthic bioindicators from the lakes of Northern Yakutia (Siberia, Russia) in paleoclimatic research

NASA Astrophysics Data System (ADS)

Tumanov, O. N.; Nazarova, L. B.; Frolova, L. A.; Pestryakova, L. A.

2012-04-01

High latitude regions are particularly affected by global climate change. Aquatic ecosystems are known to respond quickly and sensitively to such changes (Carpenter et al., 1992; Findlay et al. 2001; Smol et al., 2005). This effect is especially dramatic in regions with continental climates such as Northern and Eastern Siberia. In 2008, Russian-German expedition investigated 33 lakes of Kolyma river basin, North-Eastern Yakutia. The region of investigation is located in the mouth of Kolyma river between approximately 68°2' and 69°4' N and between 159°8' and 161°9' E. It's a most north-eastern region of Yakutia, so it's suitable for paleolimnological investigations. The investigated lakes are situated along the 200 km transect crossing 3 vegetation zones: polygonal tundra, forest tundra and northern taiga. The main aims were establishing a calibration dataset for paleoenvironmental reconstructions by using aquatic organisms, investigation of limnological variables and the influence of the environmental conditions on distribution of aquatic organisms in Yakutian lakes. The modern benthic fauna of the lakes is represented by 89 taxa from 14 taxonomic groups. The most abundant group was Mollusca. The most taxonomically diverse group was Chironomidae. A unique for this region species were discovered, such as Cincinna kamchatica, Physa jarochnovitschae, Colymbetes dolabratus, Ilybius wasastjernae, Xestochironomus sp., Agrypnia sp. etc. Cluster analysis of taxonomical composition of the benthic fauna of these lakes showed high dependency to vegetation zones. The highest levels of hydrobiological indexes (Shannon, Evenness, species richness) were registered in forest tundra. CCA analysis showed that the most influential factors in species distribution were climate-dependant factors, such as mean Tair of July, pH and water depth. Data from taxonomical analysis of Chironomidae group were used for establishing a calibration dataset for paleoenvironmental reconstructions.

Parameterization of DFTB3/3OB for Sulfur and Phosphorus for Chemical and Biological Applications

PubMed Central

2015-01-01

We report the parametrization of the approximate density functional tight binding method, DFTB3, for sulfur and phosphorus. The parametrization is done in a framework consistent with our previous 3OB set established for O, N, C, and H, thus the resulting parameters can be used to describe a broad set of organic and biologically relevant molecules. The 3d orbitals are included in the parametrization, and the electronic parameters are chosen to minimize errors in the atomization energies. The parameters are tested using a fairly diverse set of molecules of biological relevance, focusing on the geometries, reaction energies, proton affinities, and hydrogen bonding interactions of these molecules; vibrational frequencies are also examined, although less systematically. The results of DFTB3/3OB are compared to those from DFT (B3LYP and PBE), ab initio (MP2, G3B3), and several popular semiempirical methods (PM6 and PDDG), as well as predictions of DFTB3 with the older parametrization (the MIO set). In general, DFTB3/3OB is a major improvement over the previous parametrization (DFTB3/MIO), and for the majority cases tested here, it also outperforms PM6 and PDDG, especially for structural properties, vibrational frequencies, hydrogen bonding interactions, and proton affinities. For reaction energies, DFTB3/3OB exhibits major improvement over DFTB3/MIO, due mainly to significant reduction of errors in atomization energies; compared to PM6 and PDDG, DFTB3/3OB also generally performs better, although the magnitude of improvement is more modest. Compared to high-level calculations, DFTB3/3OB is most successful at predicting geometries; larger errors are found in the energies, although the results can be greatly improved by computing single point energies at a high level with DFTB3 geometries. There are several remaining issues with the DFTB3/3OB approach, most notably its difficulty in describing phosphate hydrolysis reactions involving a change in the coordination number of

Determining OBS Instrument Orientations: A Comparison of Algorithms

NASA Astrophysics Data System (ADS)

Doran, A. K.; Laske, G.

2015-12-01

The alignment of the orientation of the horizontal seismometer components with the geographical coordinate system is critical for a wide variety of seismic analyses, but the traditional deployment method of ocean bottom seismometers (OBS) precludes knowledge of this parameter. Current techniques for determining the orientation predominantly rely on body and surface wave data recorded from teleseismic events with sufficiently large magnitudes. Both wave types experience lateral refraction between the source and receiver as a result of heterogeneity and anisotropy, and therefore the arrival angle of any one phase can significantly deviate from the great circle minor arc. We systematically compare the results and uncertainties obtained through current determination methods, as well as describe a new algorithm that uses body wave, surface wave, and differential pressure gauge data (where available) to invert for horizontal orientation. To start with, our method is based on the easily transportable computer code of Stachnik et al. (2012) that is publicly available through IRIS. A major addition is that we utilize updated global dispersion maps to account for lateral refraction, as was done by Laske (1995). We also make measurements in a wide range of frequencies, and analyze surface wave trains of repeat orbits. Our method has the advantage of requiring fewer total events to achieve high precision estimates, which is beneficial for OBS deployments that can be as short as weeks. Although the program is designed for the purpose of use with OBS instruments, it also works with standard land installations. We intend to provide the community with a program that is easy to use, requires minimal user input, and is optimized to work with data cataloged at the IRIS DMC.

BOREAS TF-9 SSA-OBS Branch Level Flux Data

NASA Technical Reports Server (NTRS)

Rayment, Mark B.; Jarvis, Paul G.; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

The BOREAS TF-9 team collected data that describe carbon dioxide and water vapor fluxes from foliage at the BOREAS SSA-OBS site from 07-April through 23-November-1996. The data are available in tabular ASCII files.

Increasing Alkalinity Export from Large Russian Arctic Rivers

NASA Astrophysics Data System (ADS)

Drake, T.; Zhulidov, A. V.; Gurtovaya, T. Y.; Spencer, R. G.

2017-12-01

Riverine carbonate alkalinity (HCO3- and CO32-) sourced from chemical weathering of minerals on land represents a significant sink for atmospheric CO2 over geologic timescales. The flux of alkalinity from rivers in the Arctic depends on precipitation, permafrost extent and thaw, groundwater flow paths, and surface vegetation, all of which are changing under a warming climate. Here we show that over the past four decades, the export of alkalinity from the Ob' and Yenisei Rivers has more than doubled. The increase is likely due to a combination of increasing precipitation and permafrost thaw in the watersheds, which lengthens hydrologic flow paths and increases residence time in soils. These trends have broad implications for the rate of carbon sequestration on land and the delivery of buffering capacity to the Arctic Ocean.

Biodegradation of trichloroethylene by Methylosinus trichosporium OB3b.

PubMed Central

Tsien, H C; Brusseau, G A; Hanson, R S; Waclett, L P

1989-01-01

The methanotroph Methylosinus trichosporium OB3b, a type II methanotroph, degraded trichloroethylene at rates exceeding 1.2 mmol/h per g (dry weight) following the appearance of soluble methane monooxygenase in continuous and batch cultures. Cells capable oxidizing trichloroethylene contained components of soluble methane monooxygenase as demonstrated by Western blot (immunoblot) analysis with antibodies prepared against the purified enzyme. Growth of cultures in a medium containing 0.25 microM or less copper sulfate caused derepression of the synthesis of soluble methane monooxygenase. In these cultures, the specific rates of methane and methanol oxidation did not change during growth, while trichloroethylene oxidation increased with the appearance of soluble methane monooxygenase. M. trichosporium OB3b cells that contained soluble methane monooxygenase also degraded vinyl chloride, 1,1-dichloroethylene, cis-1,2-dichloroethylene, and trans-1,2-dichloroethylene. Images PMID:2515801

OBS Data Denoising Based on Compressed Sensing Using Fast Discrete Curvelet Transform

NASA Astrophysics Data System (ADS)

Nan, F.; Xu, Y.

2017-12-01

OBS (Ocean Bottom Seismometer) data denoising is an important step of OBS data processing and inversion. It is necessary to get clearer seismic phases for further velocity structure analysis. Traditional methods for OBS data denoising include band-pass filter, Wiener filter and deconvolution etc. (Liu, 2015). Most of these filtering methods are based on Fourier Transform (FT). Recently, the multi-scale transform methods such as wavelet transform (WT) and Curvelet transform (CvT) are widely used for data denoising in various applications. The FT, WT and CvT could represent signal sparsely and separate noise in transform domain. They could be used in different cases. Compared with Curvelet transform, the FT has Gibbs phenomenon and it cannot handle points discontinuities well. WT is well localized and multi scale, but it has poor orientation selectivity and could not handle curves discontinuities well. CvT is a multiscale directional transform that could represent curves with only a small number of coefficients. It provide an optimal sparse representation of objects with singularities along smooth curves, which is suitable for seismic data processing. As we know, different seismic phases in OBS data are showed as discontinuous curves in time domain. Hence, we promote to analysis the OBS data via CvT and separate the noise in CvT domain. In this paper, our sparsity-promoting inversion approach is restrained by L1 condition and we solve this L1 problem by using modified iteration thresholding. Results show that the proposed method could suppress the noise well and give sparse results in Curvelet domain. Figure 1 compares the Curvelet denoising method with Wavelet method on the same iterations and threshold through synthetic example. a)Original data. b) Add-noise data. c) Denoised data using CvT. d) Denoised data using WT. The CvT can well eliminate the noise and has better result than WT. Further we applied the CvT denoise method for the OBS data processing. Figure 2a

In situ produced branched glycerol dialkyl glycerol tetraethers in suspended particulate matter from the Yenisei River, Eastern Siberia

NASA Astrophysics Data System (ADS)

De Jonge, Cindy; Stadnitskaia, Alina; Hopmans, Ellen C.; Cherkashov, Georgy; Fedotov, Andrey; Sinninghe Damsté, Jaap S.

2014-01-01

Soil-derived branched glycerol dialkyl glycerol tetraethers (brGDGTs) in marine river fan sediments have a potential use for determining changes in the mean annual temperature (MAT) and pH of the river watershed soils. Prior to their incorporation in marine sediments, the compounds are transported to the marine system by rivers. However, emerging evidence suggests that the brGDGTs in freshwater systems can be derived from both soil run-off and in situ production. The production of brGDGTs in the river system can complicate the interpretation of the brGDGT signal delivered to the marine system. Therefore, we studied the distribution of brGDGT lipids in suspended particulate matter (SPM) of the Yenisei River. Chromatographic improvements allowed quantification of the recently described hexamethylated brGDGT isomer, characterized by having two methyl groups at the 6/6‧ instead of the 5/5‧ positions, in an environmental dataset for the first time. This novel compound was the most abundant brGDGT in SPM from the Yenisei. Its fractional abundance correlated well with that of the 6-methyl isomer of the hexamethylated brGDGT that contains one cyclopentane moiety. The Yenisei River watershed is characterized by large differences in MAT (>11 °C) as it spans a large latitudinal range (46-73°N), which would be expected to be reflected in brGDGT distributions of its soils. However, the brGDGT distributions in its SPM show little variation. Furthermore, the reconstructed pH values are high compared to the watershed soil pH. We, therefore, hypothesize that the brGDGTs in the Yenisei River SPM are predominantly produced in situ and not primarily derived from erosion of soil. This accounts for the absence of a change in the temperature signal, as the river water temperature is more stable. Using a lake calibration, the reconstructed temperature values agree with the mean summer temperatures (MST) recorded. The brGDGTs delivered to the sea by the Yenisei River during this

Reconstructing the landscape structure of the Lena-Angara interfluve (south part of Eastern Siberia)

NASA Astrophysics Data System (ADS)

Atutova, Zhanna

2015-04-01

which were sown as a test and as frost/freeze protection for grain crops. The meadow complexes in this territory are the result of the economic activities; therefore, they were concentrated mainly nearby human residence. The banks of the Ilga river were populated by Tungus tribes, who were engaged in hunting, because they fell short of meadow spaces. The upper reaches of the Kulenga were the home for uluses (inhabited summer localities of the Buryats) with nearby utuks, a peculiar kind of artificial meadows where grasses were not sown but grew by themselves, without any human participation. The research done in this study forms part of the program focusing on the study into different-time characteristics of the landscape structure for the southern areas of the Angara-Lena interfluve. The findings will be compared with the contemporary landscape structure in order to determine the spatiotemporal specific character of variability in natural and transformed complexes. The reported study was partially supported by RFBR and Government of Irkutsk region, project No 14-45-04002 r_siberia_a.

Opisthorchis felineus infection prevalence in Western Siberia: A review of Russian literature.

PubMed

Fedorova, Olga S; Fedotova, Marina M; Sokolova, Tatiana S; Golovach, Ekaterina A; Kovshirina, Yulia V; Ageeva, Tatiana S; Kovshirina, Anna E; Kobyakova, Olga S; Ogorodova, Ludmila M; Odermatt, Peter

2018-02-01

In this study we reviewed Russian scientific literature (scientific publications, book chapters, monographs) published between 1 January 1979 and 31 August 2015 from two sources: Main database of the Russian Scientific Electronic Library (eLIBRARY, http://elibrary.ru/), and the Scientific Medical Library of Siberian State Medical University (http://medlib.tomsk.ru/). Specifically, the review details the infection prevalence of Opisthorchis felineus (O. felineus) in Western Siberia, Russian Federation. From the primary key words screening, 1591 records were identified from which 32 Russian-language publications were relevant. The lowest O. felineus infection rate of 0.4% was reported in Tatarstan Republic, and the highest reached 83.9% in the Khanty-Mansiysk Autonomous Okrug. The infection prevalence was lower in children than in adults and increased with age. O. felineus infection was detected more often in indigenous population than in migrants. Infection intensity in western regions (Permskaya, Bryanskaya Oblast) was low and varied from 15 to 336 eggs per gram stool (epg), while in endemic regions it reached more than 2000 epg. In some settlements the mean intensity infection was 5234 epg. The high rates of intensity were registered in regions with a high prevalence of infection. Based on obtained data, a map of O. felineus infection prevalence in Western Siberia was developed. After mapping the results, the highest prevalence was detected in Tyumenskaya Oblast with over 60%, while the Tomskaya Oblast had the lowest prevalence at fewer than 19.0%. Khanty-Mansiysk Autonomus Okrug, Altaiskii Krai, Novosibirskaya Oblast and Omskaya Oblast had an average level of O. felineus infection of 20-39%. According to the results of the review, Western Siberia must be considered as highly endemic region for opisthorchiasis in the Russian Federation. The development of a control program specific for the Russian community is warranted. Copyright © 2017 Elsevier B.V. All rights

Fire Impact on Phytomass and Carbon Emissions in the Forests of Siberia

NASA Astrophysics Data System (ADS)

Ivanova, Galina A.; Zhila, Sergei V.; Ivanov, Valery A.; Kovaleva, Nataly M.; Kukavskaya, Elena A.; Platonova, Irina A.; Conard, Susan G.

2014-05-01

Siberian boreal forests contribute considerably to the global carbon budget, since they take up vast areas, accumulate large amount of carbon, and are sensitive to climatic changes. Fire is the main forest disturbance factor, covering up to millions of hectares of boreal forests annually, of which the majority is in Siberia. Carbon emissions released from phytomass burning influence atmospheric chemistry and global carbon cycling. Changing climate and land use influence the number and intensity of wildfires, forest state, and productivity, as well as global carbon balance. Fire effects on forest overstory, subcanopy woody layer, and ground vegetation phytomass were estimated on sites in light-conifer forests of the Central Siberia as a part of the project "The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia" supported by NASA (NEESPI). This study focuses on collecting quantitative data and modeling the influence of fires of varying intensity on fire emissions, carbon budget, and ecosystem processes in coniferous stands. Fires have a profound impact on forest-atmospheric carbon exchange and transform forests from carbon sinks to carbon sources lasting long after the time of burning. Our long-term experiments allowed us to identify vegetation succession patterns in taiga Scots pine stands after fires of known behavior. Estimating fire contributions to the carbon budget requires consideration of many factors, including vegetation type and fire type and intensity. Carbon emissions were found to depend on fire intensity and weather. In the first several years after fire, the above-ground phytomass appeared to be strongly controlled by fire intensity. However, the influence of burning intensity on organic matter accumulation was found to decrease with time.

Content and distribution of trace metals in pristine permafrost environments of Northeastern Siberia, Russia

NASA Astrophysics Data System (ADS)

Antcibor, I.; Eschenbach, A.; Kutzbach, L.; Bolshiyanov, D.; Pfeiffer, E.-M.

2012-04-01

Arctic regions are one of the most sensitive areas with respect to climatic changes and human impacts. Research is required to discover how the function of permafrost soils as a buffering system for metal pollutants could change in response to the predicted changes. The goal of this work is to determine the background levels of trace metals in the pristine arctic ecosystems of the Lena River Delta in Northeastern Siberia and to evaluate the possible effect of human impacts on this arctic region. The Lena River Delta represents areas with different dominating geomorphologic processes that can generally be divided between accumulation and erosion sites. Frequent changes of the river water level create different periods of sedimentation and result in the formation of stratified soils and sediment layers which are dominated either by mineral substrates with allochthonous organic matter or pure autochthonous peat. The deposited sediments that have formed the delta islands are mostly composed of sand fractions; therefore the buffering effects of clay materials can be neglected. Samoylov Island is representative of the south-central and eastern modern delta surfaces of the Lena River Delta and is selected as a pilot study site. We determined total element contents of Fe, Mn, Zn, Cd, Ni, Cu, As, Pb, Co and Hg in soil horizons from different polygonal elevated rims, polygonal depressed centers and the middle floodplain. High gravimetric concentrations (related to dry mass of soil material) of Mn and Fe are found within all soil profiles and vary from 0.14 to 1.39 g kg-1 and from 10.7 to 41.2 g kg-1, respectively. While the trace element concentrations do not exceed typical crustal abundances, the maximum values of most of the metals are observed within the soil profile situated at the middle floodplain. This finding suggests that apart from the parent material the second potential source of trace metals is due to allochthonous substance input during annual flooding of the

Continental hydrology from satellite multi-sensor data and in situ observations

NASA Astrophysics Data System (ADS)

Kouraev, A. V.

2009-04-01

Continental waters represent a tiny part of the total water amount on Earth, but play a major role in climate variability and have paramount importance for terrestrial ecosystems and human needs. They are an integral part of the global climate system with important links and feedbacks generated through its influence on surface energy and moisture fluxes between continental water, atmosphere and oceans. It is important to well understand what are temporal and spatial scales of variability of continental waters, what are teleconnections, feedbacks and mechanisms responsible for the changes, what are natural and anthropogenic causes of recent and historical changes in the hydrometeorological parameters. In this respect, continental hydrology is one of the research fields where acquired knowledge and understanding of natural processes will benefit from combination of conventional observations with data from SMOS and other Earth Observation satellites. We present studies of two key regions where SMOS data have the potential to significantly expand the potential of scientific and applied studies: a) Western Siberia and b) Euphrates-Tigris river system. Main part of the Western Siberia is covered by Ob' river system; which will be the main object of study for this region. This river basin is characterised by large flooded areas, frequently described as the biggest world swamp. Wetlands are also an important source of methane and source/sink for the CO2. Although wetlands played a key role in the natural variations of carbon cycle during the last climatic cycles, their temporal and spatial variations are still poorly modelled. As a consequence, it is very difficult to predict the effect of their variations with climate change and the resulting effect on the carbon cycle for the next decades. Water resources of the extensive Euphrates-Tigris (ET) river basin have vital importance for people living on its watershed, and for its ecosystems. This river basin also provides

[Wood transformation in dead-standing trees in the forest-tundra of Central Siberia].

PubMed

Mukhortova, L V; Kirdianov, A V; Myglan, V S; Guggenberger, G

2009-01-01

Changes in the composition of wood organic matter in dead-standing spruce and larch trees depending on the period after their death have been studied in the north of Central Siberia. The period after tree death has been estimated by means of cross-dating. The results show that changes in the composition of wood organic matter in 63% of cases are contingent on tree species. Wood decomposition in dead-standing trees is accompanied by an increase in the contents of alkali-soluble organic compounds. Lignin oxidation in larch begins approximately 80 years after tree death, whereas its transformation in spruce begins not earlier than after 100 years. In the forest-tundra of Central Siberia, the rate of wood organic matter transformation in dead-standing trees is one to two orders of magnitude lower than in fallen wood, which accounts for their role as a long-term store of carbon and mineral elements in these ecosystems.

Possible Detection of Pi(exp 0)-Decay Gamma-Ray Emission from Cyg OB2 by EGRET

NASA Technical Reports Server (NTRS)

Chen, W.; White, R. L.; Bertsch, D.

1996-01-01

We report possible detection of pi (exp 0) decay radiation from Cyg OB2, a nearby (1.7 kpc) massive OB star association. The EGRET flux (greater than 100 MeV) maps clearly indicate a point source whose error circle includes both Cyg OB2 and Cyg X-3. We show that Cyg X-3 is unlikely to be the counterpart for the EGRET source, because of the marginal spatial consistency and the lack of the 4.8 hour modulation seen in other high energy emissions from Cyg X-3. If confirmed, this will be the first detection by EGRET of massive stars.

VizieR Online Data Catalog: Kinematic data for stars in OB-associations (Melnik+, 2017)

NASA Astrophysics Data System (ADS)

Melnik, A. M.; Dambis, A. K.

2017-10-01

Table 1 gives the coordinates and kinematic parameters for OB-associations from the list by Blaha and Humphreys (1989AJ.....98.1598B). It presents the average Galactic coordinates l and b, the average heliocentric distance r, the total number of stars with known photometric measurements, Nt, used for determination of the distance for an OB-association. The distance r is equal to the distance from the catalog by Blaha and Humphreys, rBH, multiplied by a factor of 0.8, r=0.8*rBH. Table 1 also lists the median line-of-sight velocities Vr of OB-associations, the dispersions of line-of-sight velocities, sigma_vr, and the number of stars with known line-of-sight velocity nvr in an OB-association. The line-of-sight velocities of individual stars were taken from the catalog by Barbier-Brossat and Figon (1999, Cat. III/213). We used only the velocities measured with errors of less than 10 km/s which corresponds to the quality estimations A, B, C and D. We also present the median proper motions of OB-associations along l- and b-coordinates, mul and mub, derived from stellar proper motions taken from the catalog TGAS (2016, Cat. I/337), the dispersions of proper motions, sigma_mul and sigma_mub, as well as a number of stars, nmu, with known TGAS proper motions. Table 2 gives the spectral, photometric and kinematic data for stars in OB-associations. It presents the name of a star, the name of the OB-association to which it is assigned by Blaha and Humphreys (1989), spectral type of the star, code of its luminosity class cL: 2 - Ia, 4 - Iab, 6 - Ib, 8 - II, 10 - III, 12 - IV, 14 - V, where the corresponding odd numbers (1, 3,..., 13) reflect the uncertainty in its determination. Table 2 also shows the Galactic coordinates l and b of a star, the heliocentric distance r to its assigned OB-association, the line-of-sight velocity of the star Vr, if available, and its error evr taken from the catalog Barbier-Brossat and Figon (1999, Cat. III/213). Table 2 gives the Hipparcos number

Palaeodistribution modelling of European vegetation types at the Last Glacial Maximum using modern analogues from Siberia: Prospects and limitations

NASA Astrophysics Data System (ADS)

Janská, Veronika; Jiménez-Alfaro, Borja; Chytrý, Milan; Divíšek, Jan; Anenkhonov, Oleg; Korolyuk, Andrey; Lashchinskyi, Nikolai; Culek, Martin

2017-03-01

We modelled the European distribution of vegetation types at the Last Glacial Maximum (LGM) using present-day data from Siberia, a region hypothesized to be a modern analogue of European glacial climate. Distribution models were calibrated with current climate using 6274 vegetation-plot records surveyed in Siberia. Out of 22 initially used vegetation types, good or moderately good models in terms of statistical validation and expert-based evaluation were computed for 18 types, which were then projected to European climate at the LGM. The resulting distributions were generally consistent with reconstructions based on pollen records and dynamic vegetation models. Spatial predictions were most reliable for steppe, forest-steppe, taiga, tundra, fens and bogs in eastern and central Europe, which had LGM climate more similar to present-day Siberia. The models for western and southern Europe, regions with a lower degree of climatic analogy, were only reliable for mires and steppe vegetation, respectively. Modelling LGM vegetation types for the wetter and warmer regions of Europe would therefore require gathering calibration data from outside Siberia. Our approach adds value to the reconstruction of vegetation at the LGM, which is limited by scarcity of pollen and macrofossil data, suggesting where specific habitats could have occurred. Despite the uncertainties of climatic extrapolations and the difficulty of validating the projections for vegetation types, the integration of palaeodistribution modelling with other approaches has a great potential for improving our understanding of biodiversity patterns during the LGM.

Alterations in Oral [1-14C] 18:1n-9 Distribution in Lean Wild-Type and Genetically Obese (ob/ob) Mice

PubMed Central

Wang, Xinxia; Feng, Jie; Yu, Caihua; Shen, Qingwu W.; Wang, Yizhen

2015-01-01

Obesity may result from altered fatty acid (FA) disposal. Altered FA distribution in obese individuals is poorly understood. Lean wild-type C57BL/6J and obese C57BL/6Job/ob mice received an oral dose of [1-14C]18:1n-9 (oleic acid), and the radioactivity in tissues was evaluated at various time points. The 14C concentration decreased rapidly in gastrointestinal tract but gradually increased and peaked at 96 h in adipose tissue, muscle and skin in lean mice. The 14C concentration was constant in adipose tissue and muscle of obese mice from 4h to 168h. 14C-label content in adipose tissue was significantly affected by genotype, whereas muscle 14C-label content was affected by genotype, time and the interaction between genotype and time. There was higher total 14C retention (47.7%) in obese mice than in lean mice (9.0%) at 168 h (P<0.05). The 14C concentrations in the soleus and gastrocnemius muscle were higher in obese mice than in lean mice (P<0.05). Perirenal adipose tissue contained the highest 14C content in lean mice, whereas subcutaneous adipose tissue (SAT) had the highest 14C content and accounted for the largest proportion of total radioactivity among fat depots in obese mice. More lipid radioactivity was recovered as TAG in SAT from obese mice than from lean mice (P<0.05). Gene expression suggested acyl CoA binding protein and fatty acid binding protein are important for FA distribution in adipose tissue and muscle. The FA distribution in major tissues was altered in ob/ob mice, perhaps contributing to obesity. Understanding the disparity in FA disposal between lean and obese mice may reveal novel targets for the treatment and prevention of obesity. PMID:25826747

Effects of soil freezing and thawing on vegetation carbon density in Siberia: A modeling analysis with the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM)

NASA Astrophysics Data System (ADS)

Beer, C.; Lucht, W.; Gerten, D.; Thonicke, K.; Schmullius, C.

2007-03-01

The current latitudinal gradient in biomass suggests a climate-driven limitation of biomass in high latitudes. Understanding of the underlying processes, and quantification of their relative importance, is required to assess the potential carbon uptake of the biosphere in response to anticipated warming and related changes in tree growth and forest extent in these regions. We analyze the hydrological effects of thawing and freezing of soil on vegetation carbon density (VCD) in permafrost-dominated regions of Siberia using a process-based biogeochemistry-biogeography model, the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ-DGVM). The analysis is based on spatially explicit simulations of coupled daily thaw depth, site hydrology, vegetation distribution, and carbon fluxes influencing VCD subject to climate, soil texture, and atmospheric CO2 concentration. LPJ represents the observed high spring peak of runoff of large Arctic rivers, and simulates a realistic fire return interval of 100 to 200 years in Siberia. The simulated VCD changeover from taiga to tundra is comparable to inventory-based information. Without the consideration of freeze-thaw processes VCD would be overestimated by a factor of 2 in southern taiga to a factor of 5 in northern forest tundra, mainly because available soil water would be overestimated with major effects on fire occurrence and net primary productivity. This suggests that forest growth in high latitudes is not only limited by temperature, radiation, and nutrient availability but also by the availability of liquid soil water.

Defatted safflower seed extract inhibits adipogenesis in 3T3-L1 preadipocytes and improves lipid profiles in C57BL/6J ob/ob mice fed a high-fat diet.

PubMed

Hwang, Eun-Young; Yu, Mi-Hee; Jung, Yeon-Seop; Lee, Sam-Pin; Shon, Jin Han; Lee, Syng-Ook

2016-09-01

In the present study, we hypothesized that defatted safflower seed which is known to be rich in polyphenols might influence adipogenesis and obesity-related disorders, and therefore the anti-adipogenic and hypolipidemic effects of ethanol extract from defatted safflower (Cathamus tinctorius L.) seeds (CSE) were investigated both in cultured 3T3-L1 preadipocytes and in C57BL/6J ob/ob mice fed a high-fat diet. CSE inhibited adipocyte differentiation of 3T3-L1 preadipocytes and decreased expression of the adipogenic transcription factors, SREBP1c and PPARγ, and their target genes. Six-week-old obese (ob/ob) mice were fed a high-fat diet and treated with CSE (50 or 100 mg/kg/day) by oral gavage for 6 weeks. Body fat mass (epididymal and perirenal white adipose tissues) in the CSE-treated groups was significantly lower than that in the high-fat diet control (HFD) group, whereas average daily food intake was not significantly different among the groups. Plasma and hepatic triglyceride levels and plasma low-density lipoprotein cholesterol level were also significantly lower in the CSE groups compared to the HFD group. These results suggest that CSE which decreases body fat mass and improves lipid profiles in plasma and liver, represents a potential treatment option for obesity and associated metabolic disorders, including hyperlipidemia. Copyright © 2016 Elsevier Inc. All rights reserved.

The kinematics of the Scorpius-Centaurus OB association from Gaia DR1

NASA Astrophysics Data System (ADS)

Wright, Nicholas J.; Mamajek, Eric E.

2018-05-01

We present a kinematic study of the Scorpius-Centaurus (Sco-Cen) OB association (Sco OB2) using Gaia DR1 parallaxes and proper motions. Our goal is to test the classical theory that OB associations are the expanded remnants of dense and compact star clusters disrupted by processes such as residual gas expulsion. Gaia astrometry is available for 258 out of 433 members of the association, with revised Hipparcos astrometry used for the remainder. We use these data to confirm that the three subgroups of Sco-Cen are gravitationally unbound and have non-isotropic velocity dispersions, suggesting that they have not had time to dynamically relax. We also explore the internal kinematics of the subgroups to search for evidence of expansion. We test Blaauw's classical linear model of expansion, search for velocity trends along the Galactic axes, compare the expanding and non-expanding convergence points, perform traceback analysis assuming both linear trajectories and using an epicycle approximation, and assess the evidence for expansion in proper motions corrected for virtual expansion/contraction. None of these methods provide coherent evidence for expansion of the subgroups, with no evidence to suggest that the subgroups had a more compact configuration in the past. We find evidence for kinematic substructure within the subgroups that supports the view that they were not formed by the disruption of individual star clusters. We conclude that Sco-Cen was likely to have been born highly substructured, with multiple small-scale star formation events contributing to the overall OB association, and not as single, monolithic burst of clustered star formation.

Origin of carbon released from ecosystems affected by permafrost degradation in Northern Siberia

NASA Astrophysics Data System (ADS)

Gandois, L.; Hoyt, A.; Xu, X.; Hatte, C.; Teisserenc, R.; Tananaev, N.

2016-12-01

Permafrost soils and peatlands store half of the soil organic carbon stock worldwide, and are rapidly evolving as a result of permafrost thaw. Determining the origin (permafrost or recent photosynthesis) of carbon which is released to surface waters and the atmosphere is crucial to assess Arctic ecosystems' potential feedback to climate change. In order to evaluate it, we investigated the stable and radioactive content of carbon in solid organic matter, dissolved organic matter (DOM) and dissolved CO2 and CH4 in a discontinuous permafrost area of Siberia affected by permafrost degradation (Igarka, Graviyka catchment (67°27'11''N, 86°32'07''E)). We collected samples from the active layer, permafrost, surface water and bubbles from thermokarst lakes. We further investigated DOM and dissolved CO2 and CH4 in porewater profiles, streams and the catchment outlet. In thermokarst lakes, DOM of surface water as well as CO2 and CH4 from bubbles from lake sediments predominantly originate from modern carbon. In two locations, CO2 and CH4 from bubbles have relatively low 14C contents, with ages greater than 700 yr BP, but still younger that what was previously reported in Eastern Siberia. In all samples the Δ14C of CH4 and CO2 were strongly correlated, with CH4 being consistently older than CO2, indicating strong interrelation between CO2 and CH4 cycles. In our study, permafrost influenced CO2 and CH4 is found in small ponds where palsa collapse and the resulting bank erosion has mobilized sequestered carbon. In peatland porewater, the Δ14C of DOM, CO2 and CH4 increases with depth (DOM: 1385 ±45 yr BP at 2m), indicating a contribution from Holocene peatlands affected by permafrost. In deep layers, CO2 reduction is the dominant pathway of CH4 production, whereas acetate fermentation dominates in thermokarst lakes. In summary, the majority of dissolved CO2 and CH4 analyzed from thermokarst lakes and degraded peatlands is modern and originates from recently fixed carbon

Middle-Late Holocene environmental history of Kulunda (Southwestern Siberia): vegetation, climate, humans

NASA Astrophysics Data System (ADS)

Rudaya, N.; Nazarova, L.; Papin, D.; Nourgaliev, D.

2012-04-01

Environmental reconstruction of Mid-Late Holocene vegetation and climate was inferred from pollen records of Lake Big Yarovoe (Kulunda steppe, Southwestern Siberia). Reconstruction suggests generally prevalence of steppe during last 4.45 ka. Relatively warm and dry climate, open semi-desert and dry steppes with patchy birch forest spread between 4.45 and 3.80 ka BP. The largest development of conifers forest started in Kulunda after 3.80 ka BP. Constant presence of dark-coniferous trees Abies and especially Picea between 3.80 and 2.7 ka BP indicates the most humid period in the region during studied time. Onset of the Late Holocene is characterised by dominance of steppe with birch and pine forests in lowlands and river valleys. After AD 1860, open steppe and semi-desert vegetation with fragmentary birch forest have been dominated parallel to sharp reduction of conifers in Kulunda. These results are in agreement with general scheme of Holocene environmental history of surrounding areas including Baraba forest-steppe, Kazakh Upland and Altai Mountains. Territory of Kulunda consists many archaeological sites of Bronze, Iron and Middle Ages. Second half of Bronze Age (4.45-3.80 ka BP) was represented by local human cultures or migrants from the North Kazakhstan. The main archaeological culture of Kulunda alike in the whole Ob`-Irtysh interfluve in this period was Elunino culture. The economical activities of Elunino community were connected with animal breeding especially with sheep and goats. The most humid period (~1795-710 BC; 3.8-2.7 ka BP) in Kulunda corresponded to the end of early Bronze Age and to the onset of the Iron Age. In 18 century BC Andronovo culture, associated with the Indo-Iranians and migrants from Central Kazakhstan, spread in the region. Cattle breeding economy was distinctive features of Andronovo people, however, increase of sheep, goats and horses with transition to nomadic life style was characteristic of the late Bronze Age. This trend is in

[Testate amoebae inhabiting middle taiga bogs in Western Siberia].

PubMed

Kur'ina, I V; Preĭs, Iu I; Bobrov, A A

2010-01-01

The population of testate amoebae from the most typical middle taiga bogs of Western Siberia have been studied. More than one hundred (103) species and intraspecific taxons of testate amoebae have been revealed in recent surface samples. The relation between ecological characteristics of habitats and the composition of a Protozoa population has been demonstrated. The ecological preferences of species concerning the index of wetness, ash level, and acidity have been revealed. Using the correspondence analysis, the ecological optimums and the tolerance of species and intraspecific taxons of testate amoebae have been established.

Differential effects of n-3 polyunsaturated fatty acids on metabolic control and vascular reactivity in the type 2 diabetic ob/ob mouse.

PubMed

Mustad, Vikkie A; Demichele, Stephen; Huang, Yung-Sheng; Mika, Amanda; Lubbers, Nathan; Berthiaume, Nathalie; Polakowski, Jim; Zinker, Brad

2006-10-01

Diets rich in monounsaturated fatty acids (MUFA) are recommended for individuals with type 2 diabetes mellitus (T2DM). The American Heart Association recommends increasing intakes of n-3 polyunsaturated fatty acids (PUFA) to reduce the risk of vascular disease in high-risk individuals; however, the long-term effects of these bioactive fatty acids on glucose metabolism in insulin resistance are controversial. The present studies were conducted to evaluate the effects of diets rich in both MUFA and alpha linolenic acid (C18:3n-3, ALA), eicosapentaenoic acid (C20:5n-3, EPA), or docosahexaenoic acid (C22:6n-3, DHA), on glycemic control and other parameters related to vascular health in a mouse model of T2DM and insulin resistance. Male ob/ob mice (n = 15 per treatment) were fed 1 of 4 lipid-modified formula diets (LFDs) for 4 weeks: (1) MUFA control, (2) ALA blend, (3) EPA blend, and (4) DHA blend. A portion of a MUFA-rich lipid blend in the control LFD was replaced with 11% to 14% energy as n-3 PUFA. After 4 weeks, plasma glucose response to a standard meal (1.5 g carbohydrate/kg body weight) and insulin challenge (2 U/kg body weight, IP) was assessed, and samples were collected for analysis of glucose, insulin, and lipids. Vascular reactivity of isolated aortic rings was assessed in an identical follow-up study. The results showed that insulin-resistant mice fed an LFD with EPA and/or DHA blends had significantly (P < .05) lower triglycerides and free fatty acids, but insulin sensitivity and fasting plasma glucose were not improved. However, mice fed with the ALA blend had significantly improved insulin sensitivity when compared to those fed with other LFD (P < .05). Animals fed an LFD with n-3 PUFA from marine or plant sources showed significantly improved vascular responses as compared with the MUFA-rich LFD (E(max), P < .05) and ob/ob reference mice consuming chow (E(max) and pEC(50), P < .05). In summary, long-term consumption of LFD with n-3 PUFAs improved blood

Massive Stars in the SDSS-IV/APOGEE SURVEY. I. OB Stars

NASA Astrophysics Data System (ADS)

Roman-Lopes, A.; Román-Zúñiga, C.; Tapia, Mauricio; Chojnowski, Drew; Gómez Maqueo Chew, Y.; García-Hernández, D. A.; Borissova, Jura; Minniti, Dante; Covey, Kevin R.; Longa-Peña, Penélope; Fernandez-Trincado, J. G.; Zamora, Olga; Nitschelm, Christian

2018-03-01

In this work, we make use of DR14 APOGEE spectroscopic data to study a sample of 92 known OB stars. We developed a near-infrared semi-empirical spectral classification method that was successfully used in case of four new exemplars, previously classified as later B-type stars. Our results agree well with those determined independently from ECHELLE optical spectra, being in line with the spectral types derived from the “canonical” MK blue optical system. This confirms that the APOGEE spectrograph can also be used as a powerful tool in surveys aiming to unveil and study a large number of moderately and highly obscured OB stars still hidden in the Galaxy.

Structure-function analysis of the OB and latch domains of chlorella virus DNA ligase.

PubMed

Samai, Poulami; Shuman, Stewart

2011-06-24

Chlorella virus DNA ligase (ChVLig) is a minimized eukaryal ATP-dependent DNA sealing enzyme with an intrinsic nick-sensing function. ChVLig consists of three structural domains, nucleotidyltransferase (NTase), OB-fold, and latch, that envelop the nicked DNA as a C-shaped protein clamp. The OB domain engages the DNA minor groove on the face of the duplex behind the nick, and it makes contacts to amino acids in the NTase domain surrounding the ligase active site. The latch module occupies the DNA major groove flanking the nick. Residues at the tip of the latch contact the NTase domain to close the ligase clamp. Here we performed a structure-guided mutational analysis of the OB and latch domains. Alanine scanning defined seven individual amino acids as essential in vivo (Lys-274, Arg-285, Phe-286, and Val-288 in the OB domain; Asn-214, Phe-215, and Tyr-217 in the latch), after which structure-activity relations were clarified by conservative substitutions. Biochemical tests of the composite nick sealing reaction and of each of the three chemical steps of the ligation pathway highlighted the importance of Arg-285 and Phe-286 in the catalysis of the DNA adenylylation and phosphodiester synthesis reactions. Phe-286 interacts with the nick 5'-phosphate nucleotide and the 3'-OH base pair and distorts the DNA helical conformation at the nick. Arg-285 is a key component of the OB-NTase interface, where it forms a salt bridge to the essential Asp-29 side chain, which is imputed to coordinate divalent metal catalysts during the nick sealing steps.

Structure-Function Analysis of the OB and Latch Domains of Chlorella Virus DNA Ligase*

PubMed Central

Samai, Poulami; Shuman, Stewart

2011-01-01

Chlorella virus DNA ligase (ChVLig) is a minimized eukaryal ATP-dependent DNA sealing enzyme with an intrinsic nick-sensing function. ChVLig consists of three structural domains, nucleotidyltransferase (NTase), OB-fold, and latch, that envelop the nicked DNA as a C-shaped protein clamp. The OB domain engages the DNA minor groove on the face of the duplex behind the nick, and it makes contacts to amino acids in the NTase domain surrounding the ligase active site. The latch module occupies the DNA major groove flanking the nick. Residues at the tip of the latch contact the NTase domain to close the ligase clamp. Here we performed a structure-guided mutational analysis of the OB and latch domains. Alanine scanning defined seven individual amino acids as essential in vivo (Lys-274, Arg-285, Phe-286, and Val-288 in the OB domain; Asn-214, Phe-215, and Tyr-217 in the latch), after which structure-activity relations were clarified by conservative substitutions. Biochemical tests of the composite nick sealing reaction and of each of the three chemical steps of the ligation pathway highlighted the importance of Arg-285 and Phe-286 in the catalysis of the DNA adenylylation and phosphodiester synthesis reactions. Phe-286 interacts with the nick 5′-phosphate nucleotide and the 3′-OH base pair and distorts the DNA helical conformation at the nick. Arg-285 is a key component of the OB-NTase interface, where it forms a salt bridge to the essential Asp-29 side chain, which is imputed to coordinate divalent metal catalysts during the nick sealing steps. PMID:21527793

Southern Mariana OBS Experiment and Preliminary Results of Passive-Source Investigations

NASA Astrophysics Data System (ADS)

Le, B. M.; Lin, J.; Yang, T.; Shiyan 3, S. P. O. R.

2017-12-01

The Southern Mariana OBS Experiment (SMOE) was one of the first seismic experiments targeting the deepest part of Earth's surface. During the Phase I experiment in December 2016, an array of OBS instruments were deployed across the Challenger Deep that recorded both active-source and passive-source data. During the Phase II experiment in December 2016-June 2017, passive-source data were recorded. We have retrieved earthquake signals and processed the waveforms from the recorded global, regional and local events, respectively, during the Phase I experiment. Most of the waveforms recorded by the OBS array have fairly good quality with discernible main phases. Rayleigh waves from many earthquakes were analyzed using the frequency-time analysis and their group velocities at different periods were obtained. The dispersion curves from different Rayleigh wave propagating paths would be valuable for inverting the structure of the subducting Pacific and overriding Philippine Sea plates. Furthermore, we applied the ambient noise cross-correlation method and retrieved high-quality coherence surface wave waveforms. With its relatively high frequencies, the surface waves can be used to study the crustal structure of the region. Together with the Phase II data, we expect that this seismic experiment will provide unprecedented constraints on the structure and geodynamic processes of the southern Mariana trench.

Bacterial community in ancient permafrost alluvium at the Mammoth Mountain (Eastern Siberia).

PubMed

Brouchkov, Anatoli; Kabilov, Marsel; Filippova, Svetlana; Baturina, Olga; Rogov, Victor; Galchenko, Valery; Mulyukin, Andrey; Fursova, Oksana; Pogorelko, Gennady

2017-12-15

Permanently frozen (approx. 3.5Ma) alluvial Neogene sediments exposed in the Aldan river valley at the Mammoth Mountain (Eastern Siberia) are unique, ancient, and poorly studied permafrost environments. So far, the structure of the indigenous bacterial community has remained unknown. Use of 16S metagenomic analysis with total DNA isolation using DNA Spin Kit for Soil (MO-Bio) and QIAamp DNA Stool Mini Kit (Qiagen) has revealed the major and minor bacterial lineages in the permafrost alluvium sediments. In sum, 61 Operational Taxonomic Units (OTUs) with 31,239 reads (Qiagen kit) and 15,404 reads (Mo-Bio kit) could be assigned to the known taxa. Only three phyla, Bacteroidetes, Proteobacteria and Firmicutes, comprised >5% of the OTUs abundance and accounted for 99% of the total reads. OTUs pertaining to the top families (Chitinophagaceae, Caulobacteraceae, Sphingomonadaceae, Bradyrhizobiaceae, Halomonadaceae) held >90% of reads. The abundance of Actinobacteria was less (0.7%), whereas members of other phyla (Deinococcus-Thermus, Cyanobacteria/Chloroplast, Fusobacteria, and Acidobacteria) constituted a minor fraction of reads. The bacterial community in the studied ancient alluvium differs from other permafrost sediments, mainly by predominance of Bacteroidetes (>52%). The diversity of this preserved bacterial community has the potential to cause effects unknown if prompted to thaw and spread with changing climate. Therefore, this study elicits further reason to study how reintroduction of these ancient bacteria could affect the surrounding ecosystem, including current bacterial species. Copyright © 2017 Elsevier B.V. All rights reserved.

Chemical and dispersal characteristics of particulate emissions from forest fires in Siberia

Treesearch

Y. N. Samsonov; V. A. Ivanov; D. J. McRae; S. P. Baker

2012-01-01

Approximately 20 experimental fires were conducted on forest plots of 1-4 ha each in 2000-07 in two types of boreal forests in central Siberia, and 18 on 6 x 12-m plots in 2008-10. These experiments were designed to mimic wildfires under similar burning conditions. The fires were conducted in prescribed conditions including full documentation on pre-fire weather, pre-...

Effectiveness of forest management strategies to mitigate effects of global change in Siberia

Treesearch

Eric Gustafson; Anatoly Shvidenko; Robert Scheller; Brian Sturtevant

2011-01-01

Siberian forest ecosystems are experiencing multiple global changes. Climate change produces direct (temperature and precipitation) and indirect (altered fire regimes and increase in cold-limited insect outbreaks) effects. Although much of Siberia has not yet been subject to timber harvest, the frontier of timber cutting is advancing steadily across the region. We...

Adipose cell differentiation: evidence for a two-step process in the polyamine-dependent Ob1754 clonal line.

PubMed Central

Amri, E Z; Dani, C; Doglio, A; Etienne, J; Grimaldi, P; Ailhaud, G

1986-01-01

A subclone of preadipocyte Ob17 cells has been isolated (Ob1754 clonal line). Confluent Ob1754 cells treated with an inhibitor of spermidine and spermine synthesis, methylglyoxal bis(guanylhydrazone), were totally dependent upon putrescine addition for the expression of glycerol-3-phosphate dehydrogenase which behaved as a late marker of adipose conversion. Under these conditions, the early expression of lipoprotein lipase during growth arrest remained unchanged. Studies at the mRNA level showed that the expression of unidentified pOb24 and pGH3 mRNAs, which was parallel to that of lipoprotein lipase, is independent of polyamine addition whereas the late emergence of glycerol-3-phosphate dehydrogenase mRNA was putrescine-dependent and co-ordinated with the expression of pAL422 mRNA encoding for a myelin-P2 homologue [Bernlohr, Angus, Lane, Bolanowski & Kelly (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 5468-5472]. The appearance of lipoprotein lipase preceded DNA synthesis and post-confluent mitoses which were both putrescine-dependent and which took place before the appearance of glycerol-3-phosphate dehydrogenase. Thus the adipose conversion of Ob1754 cells involves the expression of at least two separate sets of markers which are differently regulated. Images Fig. 3. Fig. 6. PMID:3800927

PREDICTING GAIA’S PARALLAX DISTANCE TO THE CYGNUS OB2 ASSOCIATION WITH ECLIPSING BINARIES

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

Kiminki, Daniel C.; Kobulnicky, Henry A.; Álvarez, Carlos A. Vargas

2015-10-01

The Cygnus OB2 Association is one of the nearest and largest collections of massive stars in the Galaxy. Situated at the heart of the “Cygnus X” complex of star-forming regions and molecular clouds, its distance has proven elusive owing to the ambiguous nature of kinematic distances along this ℓ ≃ 80° sightline and the heavy, patchy extinction. In an effort to refine the three-dimensional geometry of key Cygnus X constituents, we have measured distances to four eclipsing double-lined OB-type spectroscopic binaries that are probable members of Cyg OB2. We find distances of 1.33 ± 0.17, 1.32 ± 0.07, 1.44 ±more » 0.18, and 1.32 ± 0.13 kpc toward MT91 372, MT91 696, CPR2002 A36, and Schulte 3, respectively. We adopt a weighted average distance of 1.33 ± 0.06 kpc. This agrees well with spectrophotometric estimates for the Association as a whole and with parallax measurements of protostellar masers in the surrounding interstellar clouds, thereby linking the ongoing star formation in these clouds with Cyg OB2. We also identify Schulte 3C (O9.5V), a 4″ visual companion to the 4.75 day binary Schulte 3(A+B), as a previously unrecognized Association member.« less

Integrated approaches to terminal Proterozoic stratigraphy: an example from the Olenek Uplift, northeastern Siberia

NASA Technical Reports Server (NTRS)

Knoll, A. H.; Grotzinger, J. P.; Kaufman, A. J.; Kolosov, P.

1995-01-01

In the Olenek Uplift of northeastern Siberia, the Khorbusuonka Group and overlying Kessyusa and Erkeket formations preserve a significant record of terminal Proterozoic and basal Cambrian Earth history. A composite section more than 350 m thick is reconstructed from numerous exposures along the Khorbusuonka River. The Khorbusuonka Group comprises three principal sedimentary sequences: peritidal dolomites of the Mastakh Formation, which are bounded above and below by red beds; the Khatyspyt and most of the overlying Turkut formations, which shallow upward from relatively deep-water carbonaceous micrites to cross-bedded dolomitic grainstones and stromatolites; and a thin upper Turkut sequence bounded by karst surfaces. The overlying Kessyusa Formation is bounded above and below by erosional surfaces and contains additional parasequence boundaries internally. Ediacaran metazoans, simple trace fossils, and vendotaenids occur in the Khatyspyt Formation; small shelly fossils, more complex trace fossils, and acritarchs all appear near the base of the Kessyusa Formation and diversify upward. The carbon-isotopic composition of carbonates varies stratigraphically in a pattern comparable to that determined for other terminal Proterozoic and basal Cambrian successions. In concert, litho-, bio-, and chemostratigraphic data indicate the importance of the Khorbusuonka Group in the global correlation of terminal Proterozoic sedimentary rocks. Stratigraphic data and a recently determined radiometric date on basal Kessyusa volcanic breccias further underscore the significance of the Olenek region in investigations of the Proterozoic-cambrian boundary.

Integrated approaches to terminal Proterozoic stratigraphy: an example from the Olenek Uplift, northeastern Siberia.

PubMed

Knoll, A H; Grotzinger, J P; Kaufman, A J; Kolosov, P

1995-01-01

In the Olenek Uplift of northeastern Siberia, the Khorbusuonka Group and overlying Kessyusa and Erkeket formations preserve a significant record of terminal Proterozoic and basal Cambrian Earth history. A composite section more than 350 m thick is reconstructed from numerous exposures along the Khorbusuonka River. The Khorbusuonka Group comprises three principal sedimentary sequences: peritidal dolomites of the Mastakh Formation, which are bounded above and below by red beds; the Khatyspyt and most of the overlying Turkut formations, which shallow upward from relatively deep-water carbonaceous micrites to cross-bedded dolomitic grainstones and stromatolites; and a thin upper Turkut sequence bounded by karst surfaces. The overlying Kessyusa Formation is bounded above and below by erosional surfaces and contains additional parasequence boundaries internally. Ediacaran metazoans, simple trace fossils, and vendotaenids occur in the Khatyspyt Formation; small shelly fossils, more complex trace fossils, and acritarchs all appear near the base of the Kessyusa Formation and diversify upward. The carbon-isotopic composition of carbonates varies stratigraphically in a pattern comparable to that determined for other terminal Proterozoic and basal Cambrian successions. In concert, litho-, bio-, and chemostratigraphic data indicate the importance of the Khorbusuonka Group in the global correlation of terminal Proterozoic sedimentary rocks. Stratigraphic data and a recently determined radiometric date on basal Kessyusa volcanic breccias further underscore the significance of the Olenek region in investigations of the Proterozoic-cambrian boundary.

Biomarkers of Contaminant Exposure in Chub (Leuciscus cephalus L.) – Biomonitoring of Major Rivers in the Czech Republic

PubMed Central

Havelkova, Marcela; Blahova, Jana; Kroupova, Hana; Randak, Tomas; Slatinska, Iveta; Leontovycova, Drahomira; Grabic, Roman; Pospisil, Richard; Svobodova, Zdenka

2008-01-01

Biochemical analysis of organisms to assess exposure to environmental contaminants is of great potential use. Biochemical markers, specifically liver enzymes of the first and the second phase of xenobiotic transformation - cytochrome P450 (CYP 450), ethoxyresorufin-O-deethylase (EROD), glutathione-S-transferase (GST) and tripeptide reduced glutathione (GSH) - were used to assess contamination of the aquatic environment at 12 locations near the mouths of major rivers in the Czech Republic. These rivers were the Lužnice, Otava, Sázava, Berounka, Vltava, Labe, Ohře, Svratka, Dyje, Morava and Odra. The indicator species selected was the Chub (Leuciscus cephalus L.). The highest levels of CYP 450 and EROD catalytic activity were found in livers of fish from the Labe (Obříství; (0.32±0.10 nmol mg−1 protein and 1061.38±545.51 pmol min−1 mg−1 protein, respectively). The highest levels of GST catalytic activity and GSH content were found in fish from the Otava (35.39±13.35 nmol min−1 mg−1 protein and 4.29±2.10 nmol GSH mg−1 protein, respectively). They were compared with levels of specific inductors of these biochemical markers in muscle. The results confirmed contamination of some river locations (Labe Obříství, Svratka;. PMID:27879837

Demonstrating appropriate silviculture for sustainable forestry in central Siberia: a Russian - American partnership

Treesearch

J. C. Brissette; S. T. Eubanks; A. J. R. Gillespie; R. J. Lasko; A. V. Rykoff

1997-01-01

A joint Northeastern Forest Experiment Station - Eastern Region team is working with Russian counterparts on a Forests for the Future Initiative in the Krasnoyarsk region of central Siberia. Russian team members include scientists from the Sukachev Institute of the Russian Academy of Sciences, managers from a number of units of the Federal Forest Service of Russia, and...

Submarine cable OBS using a retired submarine telecommunication cable: GeO-TOC program

NASA Astrophysics Data System (ADS)

Kasahara, Junzo; Utada, Hisashi; Sato, Toshinori; Kinoshita, Hajimu

1998-06-01

In order to study the Earth's structure and subduction zone tectonics, seismic data from the oceanic region are extremely important. The present seismograph distribution in the oceanic region, however, provides a very poor coverage. To improve this poor seismic coverage, a cable OBS system using a retired submarine telecommunication cable is proposed. The GeO-TOC cable runs from Ninomiya, Japan, to Guam through the Izu-Bonin forearc and the Marina Trough. The total length of the cable is 2659 km. An OBS, IZU, using the GeO-TOC cable, was successfully installed at the landward slope of the Izu-Bonin Trench in January 1997. The IZU OBS is located approximately 400 km south of Tokyo. The installation method is similar to repair work on submarine cables. The IZU OBS is equipped with three accelerometers, a hydrophone, a quartz pressure gauge, and a quartz precision thermometer with a few temperature sensors to monitor overheating of the internal electronics. After installation, the voltage increase is 90 V when the current is maintained at a constant 370 mA. Data from accelerometers are digitized by 24-bit A/D converters and sent to Ninomiya at 9600 bps for each component. Hydrophone data are sent to Ninomiya as analog signals using the AM (Amplitude Modulation) method for safety reasons. Hydrophone data are digitized at the shore station. Other slow-rate data are multiplexed and sent to the shore at 9600 bps. The instrument can be controlled by a shore computer. All data will be transmitted from Ninomiya to Tokyo and combined with other existing seismic data.

The Luminosity Function of OB Associations in the Galaxy

NASA Astrophysics Data System (ADS)

McKee, Christopher F.; Williams, Jonathan P.

1997-02-01

OB associations ionize the interstellar medium, producing both localized H II regions and diffuse ionized gas. The supernovae resulting from these associations pressurize and stir the interstellar medium. Using Smith, Biermann, & Mezger's compilation of radio H II regions in the Galaxy, and Kennicutt, Edgar, & Hodge's optical study of H II regions in nearby galaxies, we show that the luminosity distribution of giant OB associations in the Galaxy can be fit by a truncated power law of the form \\Nscra(>S)=\\Nscrau[(Su/S)-1], where S is the ionizing photon luminosity, \\Nscra(>S) is the number of associations with a luminosity of at least S, and Su is the upper limit to the distribution. The coefficient \\Nscrau is the number of the most luminous associations, with a luminosity between 0.5Su and Su. For the Galaxy, \\Nscrau=6.1 the fact that the number of the most luminous associations is significantly larger than unity indicates that there is a physical limit to the maximum size of H II regions in the Galaxy. To extend the luminosity distribution to small H II regions, we assume that the birthrate of associations, \\Nscr\\dota(>\\Nscr*), is also a truncated power law, \\Nscr\\dota(>\\Nscr*)~[(\\Nscr*u/\\Nscr*)-1], where \\Nscr* is the number of stars in the association. For large associations, the ionizing luminosity is proportional to the number of stars, S~\\Nscr* for smaller associations, we use both an analytic and a Monte Carlo approach to find the resulting luminosity distribution \\Nscra(>S). H II regions are generally centrally concentrated, with only the dense central regions being bright enough to appear in radio catalogs. Anantharamaiah postulated that radio H II regions have extended envelopes in order to account for diffuse radio recombination line emission in the Galaxy. Some of these envelopes are visible as the ionized ``worms'' discussed by Heiles and coworkers. We estimate that on the average the envelopes of radio H II regions absorb about twice

The influence of climate on peatland extent in Western Siberia since the Last Glacial Maximum

PubMed Central

Alexandrov, G. A.; Brovkin, V. A.; Kleinen, T.

2016-01-01

Boreal and subarctic peatlands are an important dynamical component of the earth system. They are sensitive to climate change, and could either continue to serve as a carbon sink or become a carbon source. Climatic thresholds for switching peatlands from sink to source are not well defined, and therefore, incorporating peatlands into Earth system models is a challenging task. Here we introduce a climatic index, warm precipitation excess, to delineate the potential geographic distribution of boreal peatlands for a given climate and landscape morphology. This allows us to explain the present-day distribution of peatlands in Western Siberia, their absence during the Last Glacial Maximum, their expansion during the mid-Holocene, and to form a working hypothesis about the trend to peatland degradation in the southern taiga belt of Western Siberia under an RCP 8.5 scenario for the projected climate in year 2100. PMID:27095029

The influence of climate on peatland extent in Western Siberia since the Last Glacial Maximum.

PubMed

Alexandrov, G A; Brovkin, V A; Kleinen, T

2016-04-20

Boreal and subarctic peatlands are an important dynamical component of the earth system. They are sensitive to climate change, and could either continue to serve as a carbon sink or become a carbon source. Climatic thresholds for switching peatlands from sink to source are not well defined, and therefore, incorporating peatlands into Earth system models is a challenging task. Here we introduce a climatic index, warm precipitation excess, to delineate the potential geographic distribution of boreal peatlands for a given climate and landscape morphology. This allows us to explain the present-day distribution of peatlands in Western Siberia, their absence during the Last Glacial Maximum, their expansion during the mid-Holocene, and to form a working hypothesis about the trend to peatland degradation in the southern taiga belt of Western Siberia under an RCP 8.5 scenario for the projected climate in year 2100.

Preliminary results of the Source China Sea passive source OBS array experiment

NASA Astrophysics Data System (ADS)

Yang, T.; Liu, C.; Pei, Y.; Xia, S.

2013-12-01

The Scarborough, or Huangyan, Seamount chain in South China Sea (SCS) represents an extreme case of the global mid-ocean ridge system where the magmatism continues for many million years after the cessation of spreading. To understand this unique process, the South China Sea Deep (SCSD) program funded an experiment deploying a passive source OBS array to image the lithospheric structure beneath the extinct ridge. In April 2012, 18 passive source OBSs, including 15 Guralp CMG-40T OBS and 3 I-4C OBS, were deployed around the Huangyan Island for one year. 11 OBSs were successfully recovered this April, and their data are being processed. Here we present some preliminary results from analyses of this dataset, including the general quality of three-component seismograms, characteristics of seafloor ambient noise spectra, determining the OBS orientation from the Rayleigh wave polarization, and the dispersion analysis of Rayleigh waves. We found that, for most stations, seismograms from teleseismic, regional and local events are generally good with the horizontal records being comparable with vertical component. The noise levels in these seafloor stations are much higher than land-based stations, especially in shorter periods, likely suggesting the direct and stronger impact from the tempestuous SCS. Applications of more sophisticated seismic techniques such as surface wave tomography, seismic anisotropy, receiver function and ambient noise cross-correlation are underway. In addition to the low recovery rate, there are other lessons learned from this experiment. For example, at least two stations have detectable timing problems; Airgun shots should have been used to constrain the timings and orientations in both deployment and recovery. It is still challenging and costly to carry out long-term passive source seismic observations in deep sea.

[Julian Talko-Hryncewicz--physician, anthropologist and Siberia explorer].

PubMed

Supady, Jerzy

2007-01-01

Julian Talko-Hryncewicz was born in Polish family of noble descent in Lithuania in 1850. He graduated from University in Kiev with diploma in medicine in 1876. He begun his practice in Zwinogródka in Ukraine. He left to Siberia in 1891 where he got the job of regional physician in the town Troickosowsk. He got back to Poland to run the Department of Anthropology at the Jagiellonian University in 1809. During the First World War he organised the Buriacki Field Hospital (1915-1917) in Petersburg. In the independent Poland he got back to the Jagiellonian University where he published many medical and anthropological publications. He died in Cracow in 1936.

Climate-Driven Changes Within the Larch Forest of Northern Siberia

NASA Astrophysics Data System (ADS)

Kharuk, V.

2015-12-01

Thanks to the support of NASA's Carbon Cycle and Ecosystem Focus Area programs, joint NASA/ Siberian Branch of the Russian Academy of Sciences studies have been conducted throughout Siberia. The overall objective has been to obtain field and satellite measurements to examine carbon stocks and track changes in forests across this vast area. In this presentation, we discuss some of the finding from this 25+ year collaboration' i.e., observed climate-driven changes within larch communities in northern Siberia. Field measurements and satellite data, including Terra/MODIS, Landsat, GRACE and QuickBird were used for analysis of forest conditions. The following results will be discussed. (1). At the northern limit of larch (Larix gmelinii) range (i.e.,~72°N) tree mortality was observed during the cooling period from the 16th century to the beginning of the 19th century. Post- Little Ice Age (LIA) trees re-establishment followed warming temperatures by the middle of the19th century. The current tree line has recovered to the pre-LIA line location although tree heights and stand densities are comparatively lower. The mean rate of upward migration was found to be 0.35 m yr-1 (with a range of 0.21-0.58). (2) The migration of the "dark needle conifers" (DNC: Abies sibirica, Pinus sibirica, Picea obovata) into the southern margin zone of larch dominated forest was documented. Meanwhile, within the traditional DNC range decline and mortality of both Siberian pine and fir were observed and attributed, primarily, due to an increased drought. (3) Within Central Siberia larch growth is limited by early summer temperatures and available water from thawing permafrost. Larch tree ring width (TRW) correlated with early summer temperatures and water vapor pressure (r = 0.73 and r = 0.69, respectively), drought (SPEI; r = 0.68-0.82), snow accumulation (r = 0.61), previous year precipitation (r = 0.63) and soil water anomalies (r = 0.79). Larch TRW growth and Gross Primary Productivity

River Export of Dissolved and Particulate Organic Carbon from Permafrost and Peat Deposits across the Siberian Arctic

NASA Astrophysics Data System (ADS)

Wild, B.; Andersson, A.; Bröder, L.; Vonk, J.; Hugelius, G.; McClelland, J. W.; Raymond, P. A.; Gustafsson, O.

2017-12-01

Permafrost and peat deposits of northern high latitudes store more than 1300 Pg of organic carbon. This carbon has been preserved for thousands of years by cold and moist conditions, but is now increasingly mobilized as temperatures rise. While part will be degraded to CO2 and CH4 and amplify global warming, part will be exported by rivers to the Arctic Ocean where it can be degraded or re-buried by sedimentation. We here use the four large Siberian rivers Ob, Yenisey, Lena, and Kolyma as natural integrators of carbon mobilization in their catchments. We apply isotope based source apportionments and Markov Chain Monte Carlo Simulations to quantify contributions of organic carbon from permafrost and peat deposits to organic carbon exported by these rivers. More specifically, we compare the 14C signatures of dissolved and particulate organic carbon (DOC, POC) sampled close to the river mouths with those of five potential carbon sources; (1) recent aquatic and (2) terrestrial primary production, (3) the active layer of permafrost soils, (4) deep Holocene deposits (including thermokarst and peat deposits) and (5) Ice Complex Deposits. 14C signatures of these endmembers were constrained based on extensive literature review. We estimate that the four rivers together exported 2.4-4.5 Tg organic carbon from permafrost and peat deposits per year. While total organic carbon export was dominated by DOC (90%), the export of organic carbon from permafrost and peat deposits was more equally distributed between DOC (56%) and POC (44%). Recent models predict that ca. 200 Pg carbon will be lost as CO2 or CH4 by 2100 (RCP8.5) from the circumarctic permafrost area, of which roughly a quarter is drained by the Ob, Yenisey, Lena, and Kolyma rivers. Our comparatively low estimates of river carbon export thus suggest limited transfer of organic carbon from permafrost and peat deposits to high latitude rivers, or its rapid degradation within rivers. Our findings highlight the importance

Further RIOTS4 Characterization of Field OB Stars in the SMC

NASA Astrophysics Data System (ADS)

Oey, M. S.; Barnes, Jesse R.; Paggeot, Kevin J.; Dorigo Jones, John; Castro, Norberto; Simon-Diaz, Sergio; Kratter, Kaitlin M.; Moe, Maxwell; Szymanski, Michal

2018-06-01

We present recent results from the Runaways and O-Type Star Spectroscopic Survey of the SMC (RIOTS4), a survey quantifying properties of the field OB stars in the Small Magellanic Cloud (SMC). Based on PSF-fitting photometry and astrometry of OGLE-III I-band images, we quantify the degree of isolation for the target OB stars, classifying them as "tip-of-the-iceberg" stars accompanied by small, sparse, clusters; or as true, isolated field stars. Many of these field stars must be runaways, which we evaluate using GAIA DR2 proper motions. We measure v sin i using the IACOB code Fourier analysis, finding that the bimodal distribution of projected rotation velocities is less pronounced for O stars than early B stars. We examine rotation in relation to relative isolation and runaway status.

VizieR Online Data Catalog: Properties of OB associations in IC 1613 (Garcia+, 2010)

NASA Astrophysics Data System (ADS)

Garcia, M.; Herrero, A.; Castro, N.; Corral, L.; Rosenberg, A.

2014-06-01

To understand the structure and evolution of massive stars, systematic surveys of the Local Group galaxies have been undertaken, to find these objects in environments of different chemical abundances. We focus on the metal-poor irregular galaxy IC 1613 to analyze the stellar and wind structure of its low-metallicity massive stars. We ultimately aim to study the metallicity-dependent driving mechanism of the winds of blue massive stars and use metal-poor massive stars of the Local Volume as a proxy for the stars in the early Universe. In a previous paper we produced a list of OB associations in IC 1613. Their properties are not only a powerful aid towards finding the most interesting candidate massive stars, but also reveal the structure and recent star formation history of the galaxy. We characterize these OB associations and study their connection with the galactic global properties. The reddening-free Q parameter is a powerful tool in the photometric analysis of young populations of massive stars, since it exhibits a smaller degree of degeneracy with OB spectral types than the B-V color. The color-magnitude diagram (Q vs. V) of the OB associations in IC 1613 is studied to determine their age and mass, and confirm the population of young massive stars. We identified more than 10 stars with M>=50M⊙. Spectral classification available for some of them confirm their massive nature, yet we find the common discrepancy with the spectroscopically derived masses. There is a general increasing trend of the mass of the most massive member with the number of members of each association, but not with the stellar density. The average diameter of the associations of this catalog is 40pc, half the historically considered typical size of OB associations. Size increases with the association population. The distribution of the groups strongly correlates with that of neutral and ionized hydrogen. We find the largest dispersion of association ages in the bubble region of the galaxy

Teaching Soil Science and Ecology in West Siberia: 17 Years of Field Courses

ERIC Educational Resources Information Center

Siewert, Christian; Barsukov, Pavel; Demyan, Scott; Babenko, Andrey; Lashchinsky, Nikolay; Smolentseva, Elena

2014-01-01

Since 1995, soil-ecological field courses across climatic zones in West Siberia have been organized by scientists from Russia and Germany to meet growing demands for better land use practices. They are focused on virgin landscapes and soils undisturbed by anthropogenic influences to facilitate the learning processes by excluding concealing changes…

Carbon Emission from Forest Fires on Scots Pine Logging Sites in the Angara Region of Central Siberia

NASA Astrophysics Data System (ADS)

Ivanova, G. A.; Conard, S. G.; McRae, D. J.; Kukavskaya, E. A.; Bogorodskaya, A. V.; Kovaleva, N. M.

2010-12-01

Wildfire and large-scale forest harvesting are the two major disturbances in the Russian boreal forests. Non-recovered logged sites total about a million hectares in Siberia. Logged sites are characterized by higher fire hazard than forest sites due to the presence of generally untreated logging slash (i.e., available fuel) which dries out much more rapidly compared to understory fuels. Moreover, most logging sites can be easily accessed by local population; this increases the risk for fire ignition. Fire impacts on the overstory trees, subcanopy woody layer, and ground vegetation biomass were estimated on 14 logged and unlogged comparison sites in the Lower Angara Region in 2009-2010 as part of the NASA-funded NEESPI project, The Influence of Changing Forestry Practices on the Effects of Wildfire and on Interactions Between Fire and Changing Climate in Central Siberia. Based on calculated fuel consumption, we estimated carbon emission from fires on both logged and unlogged burned sites. Carbon emission from fires on logged sites appeared to be twice that on unlogged sites. Soil respiration decreased on both site types after fires. This reduction may partially offset fire-produced carbon emissions. Carbon emissions from fire and post-fire ecosystem damage on logged sites are expected to increase under changing climate conditions and as a result of anticipated increases in future forest harvesting in Siberia.

Dynamics of water mass in the Central Siberia permafrost zone based on gravity survey from the grace satellites

NASA Astrophysics Data System (ADS)

Im, S. T.; Kharuk, V. I.

2015-12-01

The GRACE gravimetric survey is applied to analyze the equivalent water mass anomalies (EWMAs) in the permafrost zone of Central Siberia. Variations in EWMAs are related to precipitation, air temperature, potential evapotranspiration, and soil composition (drainage conditions). The EWMA dynamics demonstrates two periods. The period of 2003-2008 is characterized by a positive trend. The one of 2008-2012 shows a decrease in the trend with a simultaneous increase by 30-70% of EWMA dispersion in the background of growth (up to 40%) of precipitation variability. The rate of water mass increment demonstrates a positive correlation with the sand and gravel contents in soil ( r = 0.72) and a negative one with clay content ( r =-0.69 to-0.77). For Taimyr Peninsula, there is a deficit of residual water mass (~250 mm for the period of 2012-2013) indicating the deeper thawing of permafrost soils. In the Central Siberian Plateau, the indicator of more intensive permafrost thawing (and that of an increase in active layer thickness) is a considerable trend of water mass increase (2003-2008). The increasing trend of the largest Siberian rivers (Yenisei and Lena) is revealed in the period of 2003-2012.

Revising the archaeological record of the Upper Pleistocene Arctic Siberia: Human dispersal and adaptations in MIS 3 and 2

NASA Astrophysics Data System (ADS)

Pitulko, Vladimir; Pavlova, Elena; Nikolskiy, Pavel

2017-06-01

As the main external driver, environmental changes largely predetermine human population distribution, especially in the Arctic, where environmental conditions were often too extreme for human survival. Not that long ago the only evidence of human presence here was the Berelekh site in the lower reaches of the Indighirka River. This landmark dates to 13,000-12,000 years ago but it was widely accepted as documentation of the earliest stage of human dispersal in the Arctic. New research discussed here, shows that humans began colonizing the Siberian Arctic at least by the end of the early stage of MIS 3 at around 45,000 years ago. For now, this earliest known stage of human occupation in the arctic regions is documented by the evidence of human hunting. The archaeological record of continued human occupation is fragmentary; nevertheless, evidence exists for each significant phase including the Last Glacial Maximum (LGM). Siberian Arctic human populations were likely supported by the local mammoth population, which provided humans with food and raw material in the form of mammoth tusks. Processing of mammoth ivory is recognized widely as one of the most important peculiarities of the material culture of ancient humans. In fact, ivory tool manufacturing is one of the most important innovations of the Upper Palaeolithic in northern Eurasia. Technology that allowed manufacturing of long ivory shafts - long points and full-size spears - was critical in the tree-less open landscapes of Eurasian mammoth steppe belt. These technological skills reach their greatest extent and development shortly before the Last Glacial Maximum but are recognizable until the Pleistocene-Holocene boundary across Northern Eurasia in all areas populated by mammoths and humans. Loss of this stable source of raw material due to the late Pleistocene mammoth extinction may have provoked a shift in post-LGM Siberia to the Beringian microblade tradition. This paper reviews the most important

The significance of mid-latitude rivers for weathering rates and chemical fluxes: Evidence from northern Xinjiang rivers

NASA Astrophysics Data System (ADS)

Zhu, Bingqi; Yu, Jingjie; Qin, Xiaoguang; Rioual, Patrick; Liu, Ziting; Zhang, YiChi; Jiang, Fengqing; Mu, Yan; Li, Hongwei; Ren, Xiaozong; Xiong, Heigang

2013-04-01

signatures of dissolution of carbonates and evaporites and of continental playa deposits. Carbonates are the general predominant lithology undergoing dissolution particularly within the lesser arid areas. The pCO2 in the study rivers is out of equilibrium with respect to atmospheric pCO2, about up to ˜20 times supersaturated relative to the atmosphere but not to such an extent as the Amazon in the floodplain. A roughly positive relationship is observed between solute concentrations and the drought index (DI) for natural waters in the region, indicating a coupled mountain-basin climate has a direct effect. The relative contributions of end-member solute sources to the total dissolved cations from each watershed have been quantitatively estimated using dissolved load balance models, showing the results as evaporite dissolution > carbonate weathering > silicate weathering > atmospheric input for the whole catchment. The areal total dissolved fluxes range from 0.05 to 2.53 × 106 mol/km2/yr, 0.02-2.09 × 106 mol/km2/yr and 0.01-1.04 × 106 mol/km2/yr in the Yili, Zhungarer and Erlqis, respectively, comparable to those of Chinese and Siberia rivers draining sedimentary platforms, even though they are in drastically different climatic regimes. In general, the fluxes from rivers in sedimentary basins are comparable to those from orogenic zones, but are much higher than in the shield regions. The CO2 consumption by aluminosilicate weathering (0.2-284 × 103 mol/km2/yr) is much smaller than in active orogenic belts (19-1750 × 103 mol/km2/yr in similar latitudes and 143-1000 × 103 mol/km2/yr in the tropical basins), but comparable to those of the Chinese (7-106 × 103 mol/km2/yr) and Siberia (16-112 × 103 mol/km2/yr) rivers.

Neanderthals in central Asia and Siberia.

PubMed

Krause, Johannes; Orlando, Ludovic; Serre, David; Viola, Bence; Prüfer, Kay; Richards, Michael P; Hublin, Jean-Jacques; Hänni, Catherine; Derevianko, Anatoly P; Pääbo, Svante

2007-10-18

Morphological traits typical of Neanderthals began to appear in European hominids at least 400,000 years ago and about 150,000 years ago in western Asia. After their initial appearance, such traits increased in frequency and the extent to which they are expressed until they disappeared shortly after 30,000 years ago. However, because most fossil hominid remains are fragmentary, it can be difficult or impossible to determine unambiguously whether a fossil is of Neanderthal origin. This limits the ability to determine when and where Neanderthals lived. To determine how far to the east Neanderthals ranged, we determined mitochondrial DNA (mtDNA) sequences from hominid remains found in Uzbekistan and in the Altai region of southern Siberia. Here we show that the DNA sequences from these fossils fall within the European Neanderthal mtDNA variation. Thus, the geographic range of Neanderthals is likely to have extended at least 2,000 km further to the east than commonly assumed.

BOREAS TF-7 SSA-OBS Tower Flux and Meteorological Data

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Pattey, Elizabeth; Desjardins, Raymond L.

2000-01-01

The BOREAS TF-7 team collected meteorological data as well as energy, carbon dioxide, water vapor, methane, and nitrous oxide flux data at the BOREAS SSA-OBS site. The data were collected from 24-May to 19-Sep-1994. The data are available in tabular ASCII files.

BOREAS TGB-8 Monoterpene Concentration Data over the SSA-OBS

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Lerdau, Manuel

2000-01-01

The BOREAS TGB-8 team collected data to investigate the controls over NMHC fluxes from boreal forest tree species. This data set contains measurements of monoterpene concentrations in collected foliar gas emissions and foliar samples. The data were collected at the OJP and OBS tower flux sites in the SSA and were the locus for the monoterpene emission measurements. These areas contained mature stands of jack pine and black spruce and were the focal sites in the BOREAS program for studies of biosphere/atmosphere exchange from these two habitat types. The OBS site is situated in a black spruce/sphagnum bog with the largest trees 155 years old and 10-15 m tall. The OJP site is in a jack pine forest, 80 to 120 years old, which lies on a sandy bench of glacial outwash with the largest tree standing 15 m tall. Temporally, the data cover the period of 24-May-1994 to 19-Sep-1994. The data are stored in tabular ASCII files.

Crystal Structures of RMI1 and RMI2, Two OB-Fold Regulatory Subunits of the BLM Complex

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

Wang, Feng; Yang, Yuting; Singh, Thiyam Ramsing

Mutations in BLM, a RecQ-like helicase, are linked to the autosomal recessive cancer-prone disorder Bloom's syndrome. BLM associates with topoisomerase (Topo) III{alpha}, RMI1, and RMI2 to form the BLM complex that is essential for genome stability. The RMI1-RMI2 heterodimer stimulates the dissolution of double Holliday junction into non-crossover recombinants mediated by BLM-Topo III{alpha} and is essential for stabilizing the BLM complex. However, the molecular basis of these functions of RMI1 and RMI2 remains unclear. Here we report the crystal structures of multiple domains of RMI1-RMI2, providing direct confirmation of the existence of three oligonucleotide/oligosaccharide binding (OB)-folds in RMI1-RMI2. Our structuralmore » and biochemical analyses revealed an unexpected insertion motif in RMI1N-OB, which is important for stimulating the dHJ dissolution. We also revealed the structural basis of the interaction between RMI1C-OB and RMI2-OB and demonstrated the functional importance of the RMI1-RMI2 interaction in genome stability maintenance.« less

Endurance of larch forest ecosystems in eastern Siberia under warming trends

NASA Astrophysics Data System (ADS)

Sato, H.; Iwahana, G.; Ohta, T.

2015-12-01

The larch (Larix spp.) forest in eastern Siberia is the world's largest coniferous forest. However, its existence depends on near-surface permafrost, which increases water availability for trees, and the boundary of the forest closely follows the permafrost zone. Therefore, the degradation of near-surface permafrost due to forecasted warming trends during the 21st century is expected to affect the larch forest in Siberia. However, predictions of how warming trends will affect this forest vary greatly, and many uncertainties remain about land-atmospheric interactions within the ecosystem. We developed an integrated land surface model to analyze how the Siberian larch forest will react to current warming trends. This model analyzed interactions between vegetation dynamics and thermo-hydrology and showed that, under climatic conditions predicted by the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathway (RCP) scenarios 2.6 and 8.5, annual larch net primary production (NPP) increased about 2 and 3 times, respectively, by the end of 21st century compared with that in the 20th century. Soil water content during larch growing season showed no obvious trend, even after decay of surface permafrost and accompanying sub-surface runoff. A sensitivity test showed that the forecasted warming and pluvial trends extended leafing days of larches and reduced water shortages during the growing season, thereby increasing productivity.

Investigation of ancient DNA from Western Siberia and the Sargat culture.

PubMed

Bennett, Casey C; Kaestle, Frederika A

2010-04-01

Mitochondrial DNA from 14 archaeological samples at the Ural State University in Yekaterinburg, Russia, was extracted to test the feasibility of ancient DNA work on their collection. These samples come from a number of sites that fall into two groupings. Seven samples are from three sites, dating to the 8th-12th century AD, that belong to a northern group of what are thought to be Ugrians, who lived along the Ural Mountains in northwestern Siberia. The remaining seven samples are from two sites that belong to a southern group representing the Sargat culture, dating between roughly the 5th century BC and the 5th century AD, from southwestern Siberia near the Ural Mountains and the present-day Kazakhstan border. The samples are derived from several burial types, including kurgan burials. They also represent a number of different skeletal elements and a range of observed preservation. The northern sites repeatedly failed to amplify after multiple extraction and amplification attempts, but the samples from the southern sites were successfully extracted and amplified. The sequences obtained from the southern sites support the hypothesis that the Sargat culture was a potential zone of intermixture between native Ugrian and/or Siberian populations and steppe peoples from the south, possibly early Iranian or Indo-Iranian, which has been previously suggested by archaeological analysis.

VizieR Online Data Catalog: Faint OB stars between Car and Cen (Lynga 1968)

NASA Astrophysics Data System (ADS)

Lynga, G.

2016-03-01

The instrument used is the 50/65/175cm Schmidt telescope of the Uppsala Southern Station at Mount Stromlo. The objective prism gives a dispersion of 470Angstrom/mm et Hγ. The emulsion has constantly been Kodak IIa-O, the exposure time 20min, and the width of the spectra 0.2mm. A 12 degree zone centered on the galactic equator has been scanned for OB stars. Accurate positions of the stars were added in 2016, using the results from B. Skiff (Lowell Obs.) (2 data files).

Improving Depression Treatment for Women: Integrating a Collaborative Care Depression Intervention into OB-GYN Care

PubMed Central

LaRocco-Cockburn, Anna; Reed, Susan D.; Melville, Jennifer; Croicu, Carmen; Russo, Joan; Inspektor, Michal; Edmondson, Eddie; Katon, Wayne

2013-01-01

Background Women have higher rates of depression and often experience depression symptoms during critical reproductive periods, including adolescence, pregnancy, postpartum, and menopause. Collaborative care intervention models for mood disorders in patients receiving care in an OB-GYN clinic setting have not been evaluated. Study design and methodology for a randomized, controlled trial of collaborative care depression management versus usual care in OB-GYN clinics and the details of the adapted collaborative care intervention and model implementation are described in this paper. Methods Women over age 18 years with clinically significant symptoms of depression, as measured by a Patient Health Questionnaire-9 (PHQ-9) score ≥10 and a clinical diagnosis of major depression or dysthymia, were randomized to the study intervention or to usual care and were followed for 18 months. The primary outcome assessed was change over time in the SCL-20 depression scale between baseline and 12 months. Baseline Results 205 women were randomized: 57% white, 20% African American, 9% Asian or Pacific Islander, 7% Hispanic, and 6% Native American. Mean age was 39 years. 4.6% were pregnant and 7.5% were within 12 months postpartum. The majority were single, (52%), and 95% had at least the equivalent of a high school diploma. Almost all patients met DSM IV criteria for major depression (99%) and approximately 33% met criteria for dysthymia. Conclusions An OB-GYN collaborative care team including a social worker, psychiatrist and OB-GYN physician who met weekly and used an electronic tracking system for patients were essential elements of the proposed depression care treatment model described here. Further study of models that improve quality of depression care that are adapted to the unique OB-GYN setting are needed. PMID:23939510

Possible climate warming effects on vegetation, forests, biotic (insect, pathogene) disturbances and agriculture in Central Siberia for 1960- 2050

NASA Astrophysics Data System (ADS)

Tchebakova, N. M.; Parfenova, E. I.; Soja, A. J.; Lysanova, G. I.; Baranchikov, Y. N.; Kuzmina, N. A.

2012-04-01

Regional Siberian studies have already registered climate warming over the last half a century (1960-2010). Our analysis showed that winters are already 2-3°C warmer in the north and 1-2°C warmer in the south by 2010. Summer temperatures increased by 1°C in the north and by 1-2°C in the south. Change in precipitation is more complicated, increasing on average 10% in middle latitudes and decreasing 10-20% in the south, promoting local drying in already dry landscapes. Our goal was to summarize results of research we have done for the last decade in the context of climate warming and its consequences for biosystems in Central Siberia. We modeled climate change effects on vegetation shifts, on forest composition and agriculture change, on the insect Siberian moth (Dendrolimus suprans sibiricus Tschetv) and pathogene (Lophodermium pinastri Chev) ranges in Central Siberia for a century (1960-2050) based on historical climate data and GCM-predicted data. Principal results are: In the warmer and drier climate projected by these scenarios, Siberian forests are predicted to decrease and shift northwards and forest-steppe and steppe ecosystems are predicted to dominate over 50% of central Siberia due to the dryer climate by 2080. Permafrost is not predicted to thaw deep enough to sustain dark (Pinus sibirica, Abies sibirica, and Picea obovata) taiga. Over eastern Siberia, larch (Larix dahurica) taiga is predicted to continue to be the dominant zonobiome because of its ability to withstand continuous permafrost. The model also predicts new temperate broadleaf forest and forest-steppe habitats; At least half of central Siberia is predicted to be climatically suitable for agriculture at the end of the century although potential croplands would be limited by the availability of suitable soils agriculture in central Siberia would likely benefit from climate warming Crop production may twofold increase as climate warms during the century; traditional crops (grain, potato

MUG-OBS - Multiparameter Geophysical Ocean Bottom System : a new instrumental approach to monitor earthquakes.

NASA Astrophysics Data System (ADS)

Hello, Y.; Yegikyan, M.; Charvis, P.; Verfaillie, R.; Philippe, O.

2015-12-01

There are several attempts to monitor real time seismic activity, using regional scale wired nodes, such as Neptune in Canada and in the U.S, Antares in France or DONET in Japan.On another hand there are also initiatives in deploying repeatedly OBS array like during the amphibious Cascadia Initiative (four 1-year deployments), the Japanese Pacific Array (broadband OBSs "ocean-bottom broadband dispersion survey" with 2-years autonomy), the Obsismer program in the French Lesser Antilles (eight 6-months deployments) and the Osisec program in Ecuador (four 6-months deployments). These OBSs are autonomous, they are self-recovered or recovered using an ROV. These systems are costly including ship time, and require to recover the OBS before to start working on data.Among the most recent alternative we developed a 3-years autonomy OBS equipped with a Nanometrics Trillium 120 s, a triaxial accelerometer, a differential, an absolute pressure gauge, and a hydrophone. MUG-OBS is a free falling instrument rated down to 6000 m. The installation of the sensor is monitored by acoustic commands from the surface and a health bulletin with data checking is recovered by acoustic during the installation. The major innovation is that it is possible to recover the data any time on demand (regularly every 6-months or after a seismic crisis) utilizing one of the 6 data-shuttles released from the surface by acoustic command using a one day fast cruise boat of opportunity. Since sensors stayed at the same location for 3 years (when an OBS is redeployed on the same site, it will not land in the same place), it is a perfect tool to monitor slow seismic events, background seismic activity and aftershock distribution. Clock, drift measurement and GPS localization is automatic when the shuttle reaches the surface. A new version is being developed; for remote areas, shuttles released automatically and a seismic events bulletin is transmitted. Selected data can be recovered by two- way Iridium

H-alpha LEGUS: Insights into the Field OB Star Population in Nearby Galaxies

NASA Astrophysics Data System (ADS)

Lee, Janice; Thilker, David; Kayitesi, Bridget; Chandar, Rupali; Halpha LEGUS Team

2018-01-01

The question of whether O-stars can form in isolation, without attendant clusters or associations of lower mass stars, is a topic of interest because the answer to the question can distinguish between models of star formation. To begin to investigate whether such isolated O-stars can be identified in nearby galaxies beyond the Local Group, we identify candidate field OB-stars in NGC 1313, NGC 4395 and NGC 7793, the three nearest spiral galaxies in the HST Legacy ExtraGalactic Ultraviolet Survey (LEGUS). Candidates are selected using a technique based on: (1) a reddening-free Q parameter, adapted for photometry in HST filters covering the NUV, U, & B bands; (2) isolation based on projected distance from the nearest young cluster and candidate OB star, and (3) the presence of an HII region, identified based on HST H-alpha narrowband imaging. Our catalogs enable a range of follow-up studies on massive stars, and in particular provide targets for future spectroscopic observation and analysis. We describe the candidate OB star sample, the spatial distribution of the stars, and their HII region properties, with special focus on the most isolated objects in the sample.

The Low-Mass Stellar Content of the Scorpius-Centaurus OB Association

NASA Technical Reports Server (NTRS)

Yorke, H.; Kunkel, M.; Brander, W.; Zinnecker, H.; Neuhauser, R.; Schmitt, J.; Mayor, M.; Udry, S.

2000-01-01

Based on ROSAT observations and data obtained with ground-based telescopes, we have carried out an extensive study of the low-mass pre-main-sequence population in Upper Scorpius, the youngest subgroup of the Scorpius-Centaurus OB association.

Modeling of larch forest dynamics under a changing climate in eastern Siberia

NASA Astrophysics Data System (ADS)

Nakai, T.; Kumagai, T.; Iijima, Y.; Ohta, T.; Kotani, A.; Maximov, T. C.; Hiyama, T.

2017-12-01

According to the projection by an earth system model under RCP8.5 scenario, boreal forest in eastern Siberia (near Yakutsk) is predicted to experience significant changes in climate, in which the mean annual air temperature is projected to be positive and the annual precipitation will be doubled by the end of 21st century. Since the forest in this region is underlain by continuous permafrost, both increasing temperature and precipitation can affect the dynamics of forest through the soil water processes. To investigate such effects, we adopted a newly developed terrestrial ecosystem dynamics model named S-TEDy (SEIB-DGVM-originated Terrestrial Ecosystem Dynamics model), which mechanistically simulates "the way of life" of each individual tree and resulting tree mortality under the future climate conditions. This model was first developed for the simulation of the dynamics of a tropical rainforest in the Borneo Island, and successfully reproduced higher mortality of large trees due to a prolonged drought induced by ENSO event of 1997-1998. To apply this model to a larch forest in eastern Siberia, we are developing a soil submodel to consider the effect of thawing-freezing processes. We will present a simulation results using the future climate projection.

Analysis of Climatic and Environmental Changes Using CLEARS Web-GIS Information-Computational System: Siberia Case Study

NASA Astrophysics Data System (ADS)

Titov, A. G.; Gordov, E. P.; Okladnikov, I.; Shulgina, T. M.

2011-12-01

Analysis of recent climatic and environmental changes in Siberia performed on the basis of the CLEARS (CLimate and Environment Analysis and Research System) information-computational system is presented. The system was developed using the specialized software framework for rapid development of thematic information-computational systems based on Web-GIS technologies. It comprises structured environmental datasets, computational kernel, specialized web portal implementing web mapping application logic, and graphical user interface. Functional capabilities of the system include a number of procedures for mathematical and statistical analysis, data processing and visualization. At present a number of georeferenced datasets is available for processing including two editions of NCEP/NCAR Reanalysis, JMA/CRIEPI JRA-25 Reanalysis, ECMWF ERA-40 and ERA Interim Reanalysis, meteorological observation data for the territory of the former USSR, and others. Firstly, using functionality of the computational kernel employing approved statistical methods it was shown that the most reliable spatio-temporal characteristics of surface temperature and precipitation in Siberia in the second half of 20th and beginning of 21st centuries are provided by ERA-40/ERA Interim Reanalysis and APHRODITE JMA Reanalysis, respectively. Namely those Reanalyses are statistically consistent with reliable in situ meteorological observations. Analysis of surface temperature and precipitation dynamics for the territory of Siberia performed on the base of the developed information-computational system reveals fine spatial and temporal details in heterogeneous patterns obtained for the region earlier. Dynamics of bioclimatic indices determining climate change impact on structure and functioning of regional vegetation cover was investigated as well. Analysis shows significant positive trends of growing season length accompanied by statistically significant increase of sum of growing degree days and total

The CIDA-QUEST large-scale survey of Orion OB1: evidence for rapid disk dissipation in a dispersed stellar population.

PubMed

Briceño, C; Vivas, A K; Calvet, N; Hartmann, L; Pacheco, R; Herrera, D; Romero, L; Berlind, P; Sánchez, G; Snyder, J A; Andrews, P

2001-01-05

We are conducting a large-scale, multiepoch, optical photometric survey [Centro de Investigaciones de Astronomia-Quasar Equatorial Survey Team (CIDA-QUEST)] covering about 120 square degrees to identify the young low-mass stars in the Orion OB1 association. We present results for an area of 34 square degrees. Using photometric variability as our main selection criterion, as well as follow-up spectroscopy, we confirmed 168 previously unidentified pre-main sequence stars that are about 0.6 to 0.9 times the mass of the sun (Mo), with ages of about 1 million to 3 million years (Ori OB1b) and about 3 million to 10 million years (Ori OB1a). The low-mass stars are spatially coincident with the high-mass (at least 3 Mo) members of the associations. Indicators of disk accretion such as Halpha emission and near-infrared emission from dusty disks fall sharply from Ori OB1b to Ori OB1a, indicating that the time scale for disk dissipation and possibly the onset of planet formation is a few million years.

A Business Case Analysis (BCA) of the One Box - One Wire (OB1) Joint Combined Technology Demonstration (JCTD)

DTIC Science & Technology

2009-03-01

Framework ( IATF ) as their guidance for information assurance. The IATF defines what high 5 OB1 is compatible with and intends to use legacy...standardized levels of security. The OB1 team using the IATF as guidance defines high robustness as proving to the maximum extent possible, that

Structure-guided mutational analysis of the OB, HhH, and BRCT domains of Escherichia coli DNA ligase.

PubMed

Wang, Li Kai; Nair, Pravin A; Shuman, Stewart

2008-08-22

NAD(+)-dependent DNA ligases (LigAs) are ubiquitous in bacteria and essential for growth. LigA enzymes have a modular structure in which a central catalytic core composed of nucleotidyltransferase and oligonucleotide-binding (OB) domains is linked via a tetracysteine zinc finger to distal helix-hairpin-helix (HhH) and BRCT (BRCA1-like C-terminal) domains. The OB and HhH domains contribute prominently to the protein clamp formed by LigA around nicked duplex DNA. Here we conducted a structure-function analysis of the OB and HhH domains of Escherichia coli LigA by alanine scanning and conservative substitutions, entailing 43 mutations at 22 amino acids. We thereby identified essential functional groups in the OB domain that engage the DNA phosphodiester backbone flanking the nick (Arg(333)); penetrate the minor grove and distort the nick (Val(383) and Ile(384)); or stabilize the OB fold (Arg(379)). The essential constituents of the HhH domain include: four glycines (Gly(455), Gly(489), Gly(521), Gly(553)), which bind the phosphate backbone across the minor groove at the outer margins of the LigA-DNA interface; Arg(487), which penetrates the minor groove at the outer margin on the 3 (R)-OH side of the nick; and Arg(446), which promotes protein clamp formation via contacts to the nucleotidyltransferase domain. We find that the BRCT domain is required in its entirety for effective nick sealing and AMP-dependent supercoil relaxation.

Determination of OB/OD/SF Emission Factors using Unmanned Aerial Systems

EPA Science Inventory

Instrumented, unmanned aerial systems (UASs) have been used successfully in eight campaigns since 2010 to determine emission factors from open burning (OB), open detonation (OD), and static firing (SF) demilitarization activities. These systems have sampled directly from the plu...

Diacylglycerol production induced by growth hormone in Ob1771 preadipocytes arises from phosphatidylcholine breakdown

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

Catalioto, R.M.; Ailhaud, G.; Negrel, R.

1990-12-31

Growth Hormone has recently been shown to stimulate the formation of diacylglycerol in Ob1771 mouse preadipocyte cells without increasing inositol lipid turnover. Addition of growth hormone to Ob1771 cells prelabelled with ({sup 3}H)glycerol or ({sup 3}H)choline led to a rapid, transient and stoechiometric formation of labelled diacylglycerol and phosphocholine, respectively. In contrast, no change was observed in the level of choline and phosphatidic acid whereas the release of water-soluble metabolites in ({sup 3}H)ethanolamine prelabelled cells exposed to growth hormone was hardly detectable. Stimulation by growth hormone of cells prelabelled with (2-palmitoyl 9, 10 ({sup 3}H))phosphatidylcholine also induced the production ofmore » labelled diacyglycerol. Pertussis toxin abolished both diacylglycerol and phosphocholine formation induced by growth hormone. It is concluded that growth hormone mediates diacylglycerol production in Ob1771 cells by means of phosphatidylcholine breakdown involving a phospholipase C which is likely coupled to the growth hormone receptor via a pertussis toxin-sensitive G-protein.« less

Close genetic relationships in vast territories: autosomal and X chromosome Alu diversity in Yakuts from Siberia.

PubMed

Rocañín-Arjó, Ares; Rodríguez-Botigué, Laura; Esteban, Esther; Theves, Catherine; Evdokimova, Larissa E; Fedorova, Sardana A; Gibert, Morgane; Crubezy, Eric; Moral, Pedro

2013-01-01

Twelve autosomal and 8 X chromosome Alu markers were genotyped for the first time in 161 Central and West Yakuts to test their ability to reconstruct the genetic history of these populations, the northernmost Turkic-speaker ethnic group living in Siberia. Autosomal data revealed that both groups showed extremely close genetic distances to other populations of Siberian origins that occupied areas from Lake Baikal, the ancestral place of origin of Yakuts, to North Siberia, their current territories. Autosomal and X chromosome data revealed some discrepancies on the genetic differentiation and the effective sizes of Central and West Yakuts. Such discrepancies could be related to the patrilineal and occasionally polygamous structure of these populations. Autosomal and X Alu markers are informative markers to reconstruct population past demography and history, but their utility is limited by the available data. This study represents a contribution for further investigations on these populations.

Full waveform inversion of combined towed streamer and limited OBS seismic data: a theoretical study

NASA Astrophysics Data System (ADS)

Yang, Huachen; Zhang, Jianzhong

2018-06-01

In marine seismic oil exploration, full waveform inversion (FWI) of towed-streamer data is used to reconstruct velocity models. However, the FWI of towed-streamer data easily converges to a local minimum solution due to the lack of low-frequency content. In this paper, we propose a new FWI technique using towed-streamer data, its integrated data sets and limited OBS data. Both integrated towed-streamer seismic data and OBS data have low-frequency components. Therefore, at early iterations in the new FWI technique, the OBS data combined with the integrated towed-streamer data sets reconstruct an appropriate background model. And the towed-streamer seismic data play a major role in later iterations to improve the resolution of the model. The new FWI technique is tested on numerical examples. The results show that when starting models are not accurate enough, the models inverted using the new FWI technique are superior to those inverted using conventional FWI.

Technical-Environmental Permafrost Observatories (TEPO) of northern West Siberia

NASA Astrophysics Data System (ADS)

Kurchatova, A. N.; Griva, G. I.; Osokin, A. B.; Smolov, G. K.

2005-12-01

During the last decade one of the most developed topics in environmental studies was the effect of global climate change. This has been shown to be especially pronounced in northern regions, having an important influence on the subsequent transformation of frozen soil distribution and potential permafrost degradation. In West Siberia such studies are especially important with the prospect of plans for development of oil-gas fields (Yamal, Gydan and Kara Sea shelf). Presently the enterprises independently determine the necessary research for ecological control of the territory. Therefore, the Tyumen State Oil and Gas University (TSOGU) together with one of the leading gas enterprises "Nadymgasprom" started to create an observational network along the meridian transect of northern West Siberia (Yamal-Nenets administrative district). Observational network consists from a number of monitoring sites - Technical-Environmental permafrost Observatories (TEPO). The research complex includes temperature observations in boreholes (depths of 30) equipped with automatic systems for registration and data collection; seasonal field investigations on spatial distribution and temporal variability of the snow cover and vegetation and soil distribution. TSOGU and "Nadymgasprom" plan for the realization of long-term monitoring to obtain representative results on permafrost-climate interaction. At present there are three monitoring observatories located in the main landscape types and gas fields in use since 1972 (Medvezhye), 1992 (Yubileynoe) and in development (Harasavey). The next contribution to International Polar Year (2007-2008) will be renewal of one of the former monitoring sites (established in 1972) with a long-term period of observation and creation of a new site at the Yamal peninsula (Arctic tundra zone). At the last site the installation of an automatic Climate-Soil Station is being planned in the framework of the INTAS Infrastructure Action project with cooperation of

Human evolution in Siberia: from frozen bodies to ancient DNA.

PubMed

Crubézy, Eric; Amory, Sylvain; Keyser, Christine; Bouakaze, Caroline; Bodner, Martin; Gibert, Morgane; Röck, Alexander; Parson, Walther; Alexeev, Anatoly; Ludes, Bertrand

2010-01-25

The Yakuts contrast strikingly with other populations from Siberia due to their cattle- and horse-breeding economy as well as their Turkic language. On the basis of ethnological and linguistic criteria as well as population genetic studies, it has been assumed that they originated from South Siberian populations. However, many questions regarding the origins of this intriguing population still need to be clarified (e.g. the precise origin of paternal lineages and the admixture rate with indigenous populations). This study attempts to better understand the origins of the Yakuts by performing genetic analyses on 58 mummified frozen bodies dated from the 15th to the 19th century, excavated from Yakutia (Eastern Siberia). High quality data were obtained for the autosomal STRs, Y-chromosomal STRs and SNPs and mtDNA due to exceptional sample preservation. A comparison with the same markers on seven museum specimens excavated 3 to 15 years ago showed significant differences in DNA quantity and quality. Direct access to ancient genetic data from these molecular markers combined with the archaeological evidence, demographical studies and comparisons with 166 contemporary individuals from the same location as the frozen bodies helped us to clarify the microevolution of this intriguing population. We were able to trace the origins of the male lineages to a small group of horse-riders from the Cis-Baïkal area. Furthermore, mtDNA data showed that intermarriages between the first settlers with Evenks women led to the establishment of genetic characteristics during the 15th century that are still observed today.

Human evolution in Siberia: from frozen bodies to ancient DNA

PubMed Central

2010-01-01

Background The Yakuts contrast strikingly with other populations from Siberia due to their cattle- and horse-breeding economy as well as their Turkic language. On the basis of ethnological and linguistic criteria as well as population genetic studies, it has been assumed that they originated from South Siberian populations. However, many questions regarding the origins of this intriguing population still need to be clarified (e.g. the precise origin of paternal lineages and the admixture rate with indigenous populations). This study attempts to better understand the origins of the Yakuts by performing genetic analyses on 58 mummified frozen bodies dated from the 15th to the 19th century, excavated from Yakutia (Eastern Siberia). Results High quality data were obtained for the autosomal STRs, Y-chromosomal STRs and SNPs and mtDNA due to exceptional sample preservation. A comparison with the same markers on seven museum specimens excavated 3 to 15 years ago showed significant differences in DNA quantity and quality. Direct access to ancient genetic data from these molecular markers combined with the archaeological evidence, demographical studies and comparisons with 166 contemporary individuals from the same location as the frozen bodies helped us to clarify the microevolution of this intriguing population. Conclusion We were able to trace the origins of the male lineages to a small group of horse-riders from the Cis-Baïkal area. Furthermore, mtDNA data showed that intermarriages between the first settlers with Evenks women led to the establishment of genetic characteristics during the 15th century that are still observed today. PMID:20100333

An unidentified TeV source in the vicinity of Cygnus OB2

NASA Astrophysics Data System (ADS)

Aharonian, F.; Akhperjanian, A.; Beilicke, M.; Bernlöhr, K.; Börst, H.; Bojahr, H.; Bolz, O.; Coarasa, T.; Contreras, J.; Cortina, J.; Denninghoff, S.; Fonseca, V.; Girma, M.; Götting, N.; Heinzelmann, G.; Hermann, G.; Heusler, A.; Hofmann, W.; Horns, D.; Jung, I.; Kankanyan, R.; Kestel, M.; Kettler, J.; Kohnle, A.; Konopelko, A.; Kornmeyer, H.; Kranich, D.; Krawczynski, H.; Lampeitl, H.; Lopez, M.; Lorenz, E.; Lucarelli, F.; Magnussen, N.; Mang, O.; Meyer, H.; Milite, M.; Mirzoyan, R.; Moralejo, A.; Ona, E.; Panter, M.; Plyasheshnikov, A.; Prahl, J.; Pühlhofer, G.; Rauterberg, G.; Reyes, R.; Rhode, W.; Ripken, J.; Röhring, A.; Rowell, G. P.; Sahakian, V.; Samorski, M.; Schilling, M.; Schröder, F.; Siems, M.; Sobzynska, D.; Stamm, W.; Tluczykont, M.; Völk, H. J.; Wiedner, C. A.; Wittek, W.; Uchiyama, Y.; Takahashi, T.; HEGRA Collaboration

2002-10-01

Deep observation ( ~ 113 hrs) of the Cygnus region at TeV energies using the HEGRA stereoscopic system of air Čerenkov telescopes has serendipitously revealed a signal positionally inside the core of the OB association Cygnus OB2, at the edge of the 95% error circle of the EGRET source 3EG J2033+4118, and ~ 0.5o north of Cyg X-3. The source centre of gravity is RA alphaJ2000: 20h 32m 07s+/- 9.2sstat +/-2.2ssys, Dec deltaJ2000: +41o 30' 30''+/- 2.0'stat +/- 0.4'sys. The source is steady, has a post-trial significance of +4.6sigma , indication for extension with radius 5.6' at the ~ 3sigma level, and has a differential power-law flux with hard photon index of -1.9 +/-0.3stat +/-0.3sys. The integral flux above 1 TeV amounts ~ 3% that of the Crab. No counterpart for the TeV source at other wavelengths is presently identified, and its extension would disfavour an exclusive pulsar or AGN origin. If associated with Cygnus OB2, this dense concentration of young, massive stars provides an environment conducive to multi-TeV particle acceleration and likely subsequent interaction with a nearby gas cloud. Alternatively, one could envisage gamma -ray production via a jet-driven termination shock.

Effectiveness of forest management strategies to mitigate effects of global change in south-central Siberia

Treesearch

Eric J. Gustafson; Anatoly Z. Shvidenko; Robert M. Scheller

2011-01-01

We investigated questions about the ability of broad silvicultural strategies to achieve multiple objectives (reduce disturbance losses, maintain the abundance of preferred species, mitigate fragmentation and loss of age-class diversity, and sequester aboveground carbon) under future climate conditions in Siberia. We conducted a factorial experiment using the LANDIS-II...

AmeriFlux CA-Obs Saskatchewan - Western Boreal, Mature Black Spruce

DOE Data Explorer

Black, T. Andrew [The University of British Columbia

2017-01-01

This is the AmeriFlux version of the carbon flux data for the site CA-Obs Saskatchewan - Western Boreal, Mature Black Spruce. Site Description - 53.98717° N, 105.11779° W, elavation of 628.94 m, BOREAS 1994, 1996, BERMS climate measurements began Dec. 1996 and flux measurements in Apr. 1999

Open clusters in Auriga OB2

NASA Astrophysics Data System (ADS)

Marco, Amparo; Negueruela, Ignacio

2016-06-01

We study the area around the H II region Sh 2-234, including the young open cluster Stock 8, to investigate the extent and definition of the association Aur OB2 and the possible role of triggering in massive cluster formation. We obtained Strömgren and J, H, KS photometry for Stock 8 and Strömgren photometry for two other cluster candidates in the area, which we confirm as young open clusters and name Alicante 11 and Alicante 12. We took spectroscopy of ˜33 early-type stars in the area, including the brightest cluster members. We calculate a common distance of 2.80^{+0.27}_{-0.24} kpc for the three open clusters and surrounding association. We derive an age 4-6 Ma for Stock 8, and do not find a significantly different age for the other clusters or the association. The star LS V +34°23, with spectral type O8 II(f), is likely the main source of ionization of Sh 2-234. We observe an important population of pre-main-sequence stars, some of them with discs, associated with the B-type members lying on the main sequence. We interpret the region as an area of recent star formation with some residual and very localized ongoing star formation. We do not find evidence for sequential star formation on a large scale. The classical definition of Aur OB2 has to be reconsidered, because its two main open clusters, Stock 8 and NGC 1893, are not at the same distance. Stock 8 is probably located in the Perseus arm, but other nearby H II regions whose distances also place them in this arm show quite different distances and radial velocities and, therefore, are not connected.

Siberia Integrated Regional Study megaproject: approaches, first results and challenges

NASA Astrophysics Data System (ADS)

Gordov, E. P.; Vaganov, E. A.

2010-12-01

Siberia Integrated Regional Study (SIRS, http://sirs.scert.ru/en/) is a NEESPI megaproject coordinating national and international activity in the region in line with Earth System Science Program approach whose overall objectives are to understand impact of Global change on on-going regional climate and ecosystems dynamics; to study future potential changes in both, and to estimate possible influence of those processes on the whole Earth System dynamics. Needs for SIRS are caused by accelerated warming occurring in Siberia, complexity of on-going and potential land-surface processes sharpened by inherent hydrology pattern and permafrost presence, and lack of reliable high-resolution meteorological and climatic modeling data. The SIRS approaches include coordination of different scale national and international projects, capacity building targeted to early career researchers thematic education and training, and development of distributed information-computational infrastructure required in support of multidisciplinary teams of specialists performing cooperative work with tools for sharing of data, models and knowledge. Coordination within SIRS projects is devoted to major regional and global risks rising with regional environment changes and currently is concentrated on three interrelated problems, whose solution has strong regional environmental and socio-economical impacts and is very important for understanding potential change of the whole Earth System dynamics: Permafrost border shift, which seriously threatens the oil and gas transporting infrastructure and leads to additional carbon release; Desert - steppe- forest-tundra ecosystems changes, which might vary region input into global carbon cycle as well as provoke serious socio-economical consequences for local population; and Temperature/precipitation/hydrology regime changes, which might increase risks of forest and peat fires, thus causing significant carbon release from the region under study. Some

BOREAS TF-3 Automated Chamber CO2 Flux Data from the NSA-OBS

NASA Technical Reports Server (NTRS)

Goulden, Michael L.; Crill, Patrick M.; Hall, Forrest G. (Editor); Conrad, Sara (Editor)

2000-01-01

The BOReal Ecosystem Atmosphere Study Tower Flux (BOREAS TF-3) and Trace Gas Biogeochemistry (TGB-1) teams collected automated CO2 chamber flux data in their efforts to fully describe the CO2 flux at the Northern Study Area-Old Black Spruce (NSA-OBS) site. This data set contains fluxes of CO2 at the NSA-OBS site measured using automated chambers. In addition to reporting the CO2 flux, it reports chamber air temperature, moss temperature, and light levels during each measurement. The data set covers the period from 23-Sep-1995 through 26-Oct-1995 and from 28-May-1996 through 21-Oct-1996. The data are stored in tabular ASCII files.

Marked augmentation of PLGA nanoparticle-induced metabolically beneficial impact of γ-oryzanol on fuel dyshomeostasis in genetically obese-diabetic ob/ob mice.

PubMed

Kozuka, Chisayo; Shimizu-Okabe, Chigusa; Takayama, Chitoshi; Nakano, Kaku; Morinaga, Hidetaka; Kinjo, Ayano; Fukuda, Kotaro; Kamei, Asuka; Yasuoka, Akihito; Kondo, Takashi; Abe, Keiko; Egashira, Kensuke; Masuzaki, Hiroaki

2017-11-01

Our previous works demonstrated that brown rice-specific bioactive substance, γ-oryzanol acts as a chaperone, attenuates exaggerated endoplasmic reticulum (ER) stress in brain hypothalamus and pancreatic islets, thereby ameliorating metabolic derangement in high fat diet (HFD)-induced obese diabetic mice. However, extremely low absorption efficiency from intestine of γ-oryzanol is a tough obstacle for the clinical application. Therefore, in this study, to overcome extremely low bioavailability of γ-oryzanol with super-high lipophilicity, we encapsulated γ-oryzanol in polymer poly (DL-lactide-co-glycolide) (PLGA) nanoparticles (Nano-Orz), and evaluated its metabolically beneficial impact in genetically obese-diabetic ob/ob mice, the best-known severest diabetic model in mice. To our surprise, Nano-Orz markedly ameliorated fuel metabolism with an unexpected magnitude (∼1000-fold lower dose) compared with regular γ-oryzanol. Furthermore, such a conspicuous impact was achievable by its administration once every 2 weeks. Besides the excellent impact on dysfunction of hypothalamus and pancreatic islets, Nano-Orz markedly decreased ER stress and inflammation in liver and adipose tissue. Collectively, nanotechnology-based developments of functional foods oriented toward γ-oryzanol shed light on the novel approach for the treatment of a variety of metabolic diseases in humans.

Structure-guided Mutational Analysis of the OB, HhH, and BRCT Domains of Escherichia coli DNA Ligase*S⃞

PubMed Central

Wang, Li Kai; Nair, Pravin A.; Shuman, Stewart

2008-01-01

NAD+-dependent DNA ligases (LigAs) are ubiquitous in bacteria and essential for growth. LigA enzymes have a modular structure in which a central catalytic core composed of nucleotidyltransferase and oligonucleotide-binding (OB) domains is linked via a tetracysteine zinc finger to distal helix-hairpin-helix (HhH) and BRCT (BRCA1-like C-terminal) domains. The OB and HhH domains contribute prominently to the protein clamp formed by LigA around nicked duplex DNA. Here we conducted a structure-function analysis of the OB and HhH domains of Escherichia coli LigA by alanine scanning and conservative substitutions, entailing 43 mutations at 22 amino acids. We thereby identified essential functional groups in the OB domain that engage the DNA phosphodiester backbone flanking the nick (Arg333); penetrate the minor grove and distort the nick (Val383 and Ile384); or stabilize the OB fold (Arg379). The essential constituents of the HhH domain include: four glycines (Gly455, Gly489, Gly521, Gly553), which bind the phosphate backbone across the minor groove at the outer margins of the LigA-DNA interface; Arg487, which penetrates the minor groove at the outer margin on the 3 ®-OH side of the nick; and Arg446, which promotes protein clamp formation via contacts to the nucleotidyltransferase domain. We find that the BRCT domain is required in its entirety for effective nick sealing and AMP-dependent supercoil relaxation. PMID:18515356

25 Orionis: A Kinematically Distinct 10 Myr Old Group in Orion OB1a

NASA Astrophysics Data System (ADS)

Briceño, César; Hartmann, Lee; Hernández, Jesús; Calvet, Nuria; Vivas, A. Katherina; Furesz, Gabor; Szentgyorgyi, Andrew

2007-06-01

We report here on the photometric and kinematic properties of a well-defined group of nearly 200 low-mass pre-main-sequence stars, concentrated within ~1° of the early-B star 25 Ori, in the Orion OB1a subassociation. We refer to this stellar aggregate as the 25 Orionis group. The group also harbors the Herbig Ae/Be star V346 Ori and a dozen other early-type stars with photometry, parallaxes, and some with IR excess emission, indicative of group membership. The number of high- and low-mass stars is in agreement with expectations from a standard initial mass function. The velocity distribution for the low-mass stars shows a narrow peak at 19.7 km s-1, offset ~-10 km s-1 from the velocity characterizing the younger stars of the Ori OB1b subassociation, and -4 km s-1 from the velocity of widely spread young stars of the Ori OB1a population; this result provides new and compelling evidence that the 25 Ori group is a distinct kinematic entity, and that considerable space and velocity structure is present in the Ori OB1a subassociation. The low-mass members follow a well-defined band in the color-magnitude diagram, consistent with an isochronal age of ~7-10 Myr. The ~2 time drop in the overall Li I equivalent widths and accretion fraction between the younger Ori OB1b and the 25 Ori group is consistent with the latter being significantly older. In a simple-minded kinematic evolution scenario, the 25 Ori group may represent the evolved counterpart of the younger σ Ori cluster. The 25 Ori stellar aggregate is the most populous ~10 Myr sample yet known within 500 pc, setting it as an excellent laboratory to study the evolution of solar-like stars and protoplanetary disks. Based on observations obtained at the Llano del Hato National Astronomical Observatory of Venezuela, operated by CIDA for the Ministerio de Ciencia y Tecnología the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona; and the Fred Lawrence Whipple Observatory of

Warmth and friendship abound in Siberia

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

Whitworth, K.

1978-08-01

Despite the harsh climate, 20,000,000 people occupy 6,500,000 square kilometers of land, which contains approximately 60% of all the known fuel resources of the Soviet Union. More than 12% of the world's coal reserves are concentrated in Central Siberia between the Kuznetsk basin and the Yenisei, in an area no more than two percent of the land surface. It is for this reason and knowing that many technological advances in mining had been made in this area that, in discussion with the Soviet Coal Ministry, it was agreed that a WORLD COAL Editor, in pursuant to the agreement made betweenmore » the Soviet coal magazine UGOL and WORLD COAL should visit surface openpit, deep mines and coal preparation plants and prepare this article in the issue specially devoted to Russian coal mining achievements. The trip was undertaken in the short summer months around July when the climate is unbelievably like that of the Mediterranean. Four main areas were visited, Novokusnetsk, Mezdurechensk, Irkutsk and Cheremhovo.« less

Uptake and effect of rare earth elements on gene expression in Methylosinus trichosporium OB3b

DOE PAGES

Gu, Wenyu; Farhan Ul Haque, Muhammad; DiSpirito, Alan A.; ...

2016-05-12

It is well-known that M. trichosporium OB3b has two forms of methane monooxygenase responsible for the initial conversion of methane to methanol, a cytoplasmic (soluble) methane monooxygenase (sMMO) and a membrane-associated (particulate) methane monooxygenase (pMMO) and that copper strongly regulates expression of these alternative forms of MMO. More recently, it has been discovered that M. trichosporium OB3b has multiple types of the methanol dehydrogenase (MeDH), i.e. the Mxa-MeDH and Xox-MeDH, and the expression of these two forms is regulated by the availability of the rare earth element, cerium. Here we extend these studies and show that lanthanum, praseodymium, neodymium andmore » samarium also regulate expression of alternative forms of MeDH. The effect of these rare earth elements on MeDH expression, however, was only observed in the absence of copper. Further, a mutant of M. trichosporium OB3b where the Mxa-MeDH was knocked out was able to grow in the presence of lanthanum, praseodymium and neodymium, but was not able to grow in the presence of samarium. In conclusion, collectively these data suggest that multiple levels of gene regulation by metals exist in M. trichosporium OB3b but that copper overrides the effect of other metals by an as yet unknown mechanism.« less

OB glue paste technique for establishing nude mouse human gastric cancer orthotopic transplantation models

PubMed Central

Shi, Jun; Wei, Pin-Kang; Zhang, Shen; Qin, Zhi-Feng; Li, Jun; Sun, Da-Zhi; Xiao, Yan; Yu, Zhi-Hong; Lin, Hui-Ming; Zheng, Guo-Jing; Su, Xiao-Mei; Chen, Ya-Lin; Liu, Yan-Fang; Xu, Ling

2008-01-01

AIM: To establish nude mouse human gastric cancer orthotopic transplantation models using OB glue paste technique. METHODS: Using OB glue paste technique, orthotopic transplantation models were established by implanting SGC-7901 and MKN-45 human gastric cancer cell strains into the gastric wall of nude mice. Biological features, growth of the implanted tumors, the success rate of transplantation and the rate of auto-metastasis of the two models were observed. RESULTS: The success rates of orthotopic transplan-tation of the two models were 94.20% and 96%. The rates of hepatic metastasis, pulmonary metastasis, peritoneal metastasis, lymphocytic metastasis and splenic metastasis were 42.13% and 94.20%, 48.43% and 57.97%, 30.83% and 36.96%, 67.30% and 84.06%, and 59.75% and 10.53%, respectively. The occurrence of ascites was 47.80% and 36.96%. CONCLUSION: OB glue paste technique is easy to follow. The biological behaviors of the nude mouse human gastric cancer orthotopic transplantation models established with this technique are similar to the natural processes of growth and metastasis of human gastric cancer, and, therefore, can be used as an ideal model for experimental research of proliferative metastasis of tumors. PMID:18720543

Improvements to the gridding of precipitation data across Europe under the E-OBS scheme

NASA Astrophysics Data System (ADS)

Cornes, Richard; van den Besselaar, Else; Jones, Phil; van der Schrier, Gerard; Verver, Ge

2016-04-01

Gridded precipitation data are a valuable resource for analyzing past variations and trends in the hydroclimate. Such data also provide a reference against which model simulations may be driven, compared and/or adjusted. The E-OBS precipitation dataset is widely used for such analyses across Europe, and is particularly valuable since it provides a spatially complete, daily field across the European domain. In this analysis, improvements to the E-OBS precipitation dataset will be presented that aim to provide a more reliable estimate of grid-box precipitation values, particularly in mountainous areas and in regions with a relative sparsity of input station data. The established three-stage E-OBS gridding scheme is retained, whereby monthly precipitation totals are gridded using a thin-plate spline; daily anomalies are gridded using indicator kriging; and the final dataset is produced by multiplying the two grids. The current analysis focuses on improving the monthly thin-plate spline, which has overall control on the final daily dataset. The results from different techniques are compared and the influence on the final daily data is assessed by comparing the data against gridded country-wide datasets produced by various National Meteorological Services

Variability of fire behavior, fire effects, and emissions in Scotch pine forests of central Siberia

Treesearch

D. J. McRae; Susan Conard; G. A. Ivanova; A. I. Sukhinin; Steve Baker; Y. N. Samsonov; T. W. Blake; V. A. Ivanov; A. V. Ivanov; T. V. Churkina; WeiMin Hao; K. P. Koutzenogij; Nataly Kovaleva

2006-01-01

As part of the Russian FIRE BEAR (Fire Effects in the Boreal Eurasia Region) Project, replicated 4-ha experimental fires were conducted on a dry Scotch pine (Pinus sylvestris)/lichen (Cladonia sp.)/feathermoss (Pleurozeum schreberi) forest site in central Siberia. Observations from the initial seven surface fires (2000-2001) ignited under a range of burning...

Warm Arctic-cold Siberia: comparing the recent and the early 20th-century Arctic warmings

NASA Astrophysics Data System (ADS)

Wegmann, Martin; Orsolini, Yvan; Zolina, Olga

2018-02-01

The Warm Arctic-cold Siberia surface temperature pattern during recent boreal winter is suggested to be triggered by the ongoing decrease of Arctic autumn sea ice concentration and has been observed together with an increase in mid-latitude extreme events and a meridionalization of tropospheric circulation. However, the exact mechanism behind this dipole temperature pattern is still under debate, since model experiments with reduced sea ice show conflicting results. We use the early twentieth-century Arctic warming (ETCAW) as a case study to investigate the link between September sea ice in the Barents-Kara Sea (BKS) and the Siberian temperature evolution. Analyzing a variety of long-term climate reanalyses, we find that the overall winter temperature and heat flux trend occurs with the reduction of September BKS sea ice. Tropospheric conditions show a strengthened atmospheric blocking over the BKS, strengthening the advection of cold air from the Arctic to central Siberia on its eastern flank, together with a reduction of warm air advection by the westerlies. This setup is valid for both the ETCAW and the current Arctic warming period.

Classifying seismic noise and sources from OBS data using unsupervised machine learning

NASA Astrophysics Data System (ADS)

Mosher, S. G.; Audet, P.

2017-12-01

The paradigm of plate tectonics was established mainly by recognizing the central role of oceanic plates in the production and destruction of tectonic plates at their boundaries. Since that realization, however, seismic studies of tectonic plates and their associated deformation have slowly shifted their attention toward continental plates due to the ease of installation and maintenance of high-quality seismic networks on land. The result has been a much more detailed understanding of the seismicity patterns associated with continental plate deformation in comparison with the low-magnitude deformation patterns within oceanic plates and at their boundaries. While the number of high-quality ocean-bottom seismometer (OBS) deployments within the past decade has demonstrated the potential to significantly increase our understanding of tectonic systems in oceanic settings, OBS data poses significant challenges to many of the traditional data processing techniques in seismology. In particular, problems involving the detection, location, and classification of seismic sources occurring within oceanic settings are much more difficult due to the extremely noisy seafloor environment in which data are recorded. However, classifying data without a priori constraints is a problem that is routinely pursued via unsupervised machine learning algorithms, which remain robust even in cases involving complicated datasets. In this research, we apply simple unsupervised machine learning algorithms (e.g., clustering) to OBS data from the Cascadia Initiative in an attempt to classify and detect a broad range of seismic sources, including various noise sources and tremor signals occurring within ocean settings.

New Approach to Road Construction in Oil-Producing Regions of Western Siberia

NASA Astrophysics Data System (ADS)

Piirainen, V. Y.; Estrin, Y.

2017-10-01

This article presents, as a polemic exercise, a new approach to road construction in marshland areas of oil and gas producing regions of Western Siberia. The approach is based on the use of novel modular elements that can be assembled into an integral structure by means of topological interlocking. The use of modern superlight concrete in conjunction with the new design systems based on the modular principle opens up new avenues to solving problems of road construction in regions with unstable, boggy soils.

Paleobiology of the Mesoproterozoic Billyakh Group, Anabar Uplift, northern Siberia.

PubMed

Sergeev, V N; Knoll, A H; Grotzinger, J P

1995-01-01

Silicified peritidal carbonates of the Mesoproterozoic Kotuikan and Yusmastakh Formations, Anabar Uplift, northeastern Siberia, contain exceptionally well-preserved microfossils. The assemblage is dominated by ellipsoidal akinetes of nostocalean cyanobacteria (Archaeoellipsoides) and problematic spheroidal unicells (Myxococcoides); both are allochthonous and presumably planktonic. The assemblage also includes distinctive mat-forming scytonematacean and entophysalidacean cyanobacteria, diverse short trichomes interpreted as cyanobacterial hormogonia or germinated akinetes, rare longer trichomes, and several types of colonial unicells. Although many taxa in the Kotuikan-Yusmastakh assemblage are long-ranging prokaryotes, the overall character of the assemblage is distinctly Mesoproterozoic, with its major features shared by broadly coeval floras from Canada, China, India, and elsewhere in Siberia. Microfossils also occur in middle to inner shelf shales of the Ust'-Il'ya and lower Kotuikan Formations. Leiosphaerid acritarchs (up to several hundred microns in diameter) characterize this facies. As in other Mesoproterozoic acritarch assemblages, acanthomorphic and other complex forms that typify Neoproterozoic assemblages are absent. The combination in Billyakh assemblages of exceptional preservation and low eukaryotic diversity supports the hypothesis that nucleated organisms diversified markedly near the Mesoproterozoic-Neoproterozoic boundary. The assemblages also demonstrate the antiquity of cyanobacteria capable of cell differentiation and suggest the importance of both changing peritidal substrates and evolving eukaryotes in determining stratigraphic patterns of Proterozoic prokaryotes. The permineralized assemblage contains 33 species belonging to 17 genera. Ten new species or new combinations are proposed: Archaeoellipsoides costatus n. sp., A. elongatus n. comb., A. dolichos n. comb., A. minor n. nom., A. crassus n. comb., A. major n. comb., A. bactroformis n

Paleobiology of the Mesoproterozoic Billyakh Group, Anabar Uplift, northern Siberia

NASA Technical Reports Server (NTRS)

Sergeev, V. N.; Knoll, A. H.; Grotzinger, J. P.

1995-01-01

Silicified peritidal carbonates of the Mesoproterozoic Kotuikan and Yusmastakh Formations, Anabar Uplift, northeastern Siberia, contain exceptionally well-preserved microfossils. The assemblage is dominated by ellipsoidal akinetes of nostocalean cyanobacteria (Archaeoellipsoides) and problematic spheroidal unicells (Myxococcoides); both are allochthonous and presumably planktonic. The assemblage also includes distinctive mat-forming scytonematacean and entophysalidacean cyanobacteria, diverse short trichomes interpreted as cyanobacterial hormogonia or germinated akinetes, rare longer trichomes, and several types of colonial unicells. Although many taxa in the Kotuikan-Yusmastakh assemblage are long-ranging prokaryotes, the overall character of the assemblage is distinctly Mesoproterozoic, with its major features shared by broadly coeval floras from Canada, China, India, and elsewhere in Siberia. Microfossils also occur in middle to inner shelf shales of the Ust'-Il'ya and lower Kotuikan Formations. Leiosphaerid acritarchs (up to several hundred microns in diameter) characterize this facies. As in other Mesoproterozoic acritarch assemblages, acanthomorphic and other complex forms that typify Neoproterozoic assemblages are absent. The combination in Billyakh assemblages of exceptional preservation and low eukaryotic diversity supports the hypothesis that nucleated organisms diversified markedly near the Mesoproterozoic-Neoproterozoic boundary. The assemblages also demonstrate the antiquity of cyanobacteria capable of cell differentiation and suggest the importance of both changing peritidal substrates and evolving eukaryotes in determining stratigraphic patterns of Proterozoic prokaryotes. The permineralized assemblage contains 33 species belonging to 17 genera. Ten new species or new combinations are proposed: Archaeoellipsoides costatus n. sp., A. elongatus n. comb., A. dolichos n. comb., A. minor n. nom., A. crassus n. comb., A. major n. comb., A. bactroformis n

International Permafrost Field Courses in Siberia: the Synthesis of Research and Education

NASA Astrophysics Data System (ADS)

Ablyazina, D.; Boitsov, A.; Grebenets, V.; Kaverin, D.; Klene, A.; Kurchatova, A.; Pfeiffer, E. M.; Zschocke, A.; Shiklomanov, N.; Streletskiy, D.

2009-04-01

During summers of 2007 and 2008 a series of International University Courses on Permafrost (IUCP) were conducted in West Siberia, Russia. Courses were organized as part of the International Permafrost Association (IPA) International Polar Year activities. The North of West Siberia region was selected to represent diverse permafrost, climatic and landscape conditions. The courses were jointly organized by the Moscow State University (MSU) and the Tumen' Oil and Gas University (TOGU) with the help from German and U.S. institutions. The program attracted undergraduate and graduate students with diverse interests and backgrounds from Germany, Russia and the U.S. and involved instructors specializing in different aspects of permafrost research. Courses were designed to address three major topics of permafrost-related research: a) permafrost environments characteristic of the discontinuous and continuous zones; b) field instrumentation and techniques; c) permafrost engineering and problems of development in permafrost regions. Methodologically, courses consisted of systematic permafrost investigations at long-term monitoring sites and survey-type expeditions. Systematic, process-based investigations were conducted at a network of sites which constitute the TEPO established by TOGU in collaboration with the gas company NadymGasProm. The observation complex includes an array of 30-m deep boreholes equipped with automatic data collection systems and representing characteristic permafrost landscapes of West Siberia. Boreholes are complemented by sites for snow cover, vegetation, soil, ground ice, and geomorphologic investigations. As part of student research activities, four new Circumpolar Active Layer Monitoring (CALM) sites were established in proximity to boreholes for monitoring spatial distribution and long-term dynamic of the active layer. New sites represent diverse landscapes characteristic of the West Siberian previously underrepresented in the CALM network

A critical remark on the applicability of E-OBS European gridded temperature data set for validating control climate simulations

NASA Astrophysics Data System (ADS)

Kyselý, Jan; Plavcová, Eva

2010-12-01

The study compares daily maximum (Tmax) and minimum (Tmin) temperatures in two data sets interpolated from irregularly spaced meteorological stations to a regular grid: the European gridded data set (E-OBS), produced from a relatively sparse network of stations available in the European Climate Assessment and Dataset (ECA&D) project, and a data set gridded onto the same grid from a high-density network of stations in the Czech Republic (GriSt). We show that large differences exist between the two gridded data sets, particularly for Tmin. The errors tend to be larger in tails of the distributions. In winter, temperatures below the 10% quantile of Tmin, which is still far from the very tail of the distribution, are too warm by almost 2°C in E-OBS on average. A large bias is found also for the diurnal temperature range. Comparison with simple average series from stations in two regions reveals that differences between GriSt and the station averages are minor relative to differences between E-OBS and either of the two data sets. The large deviations between the two gridded data sets affect conclusions concerning validation of temperature characteristics in regional climate model (RCM) simulations. The bias of the E-OBS data set and limitations with respect to its applicability for evaluating RCMs stem primarily from (1) insufficient density of information from station observations used for the interpolation, including the fact that the stations available may not be representative for a wider area, and (2) inconsistency between the radii of the areal average values in high-resolution RCMs and E-OBS. Further increases in the amount and quality of station data available within ECA&D and used in the E-OBS data set are essentially needed for more reliable validation of climate models against recent climate on a continental scale.

Paleomagnetic data for Siberia and Baltica in the context of testing some geodynamic models of the formation of the Central Asian Mobile Belt

NASA Astrophysics Data System (ADS)

Shatsillo, A. V.; Kuznetsov, N. B.; Dronov, A. V.

2017-09-01

The synthesis of the paleomagnetic data for the Siberian (Siberia) and East European (Baltica) platforms shows that since the Early Paleozoic they could have experienced coherent movements as a part of consolidated continental agglomeration (a composite continent), which also includes the Arctida continent. Based on the paleomagnetic data, the relative positions of the Siberia and Baltica during the Ordovician is reconstructed, and a series of paleogeographical reconstructions describing the drift of the composite continent is suggested. The results of the lithologic-facial analysis of the sedimentation settings within the Ordovician basins of the Siberian and East European platforms and paleoclimatic markers are consistent with the suggested configuration and paleogeographical position of the composite continent. The suggested reconstructions and the ages of detrital zircons from the Early Paleozoic complexes of the platform margins and some objects of the Central Asian Mobile Belt (CAMB) reasonably well agree with the hypothesis (Sengör et al., 1993) which interprets the formation of the structure of CAMB Paleozoides as a result of the evolution of the island arc stretching along the margins of Siberia and Baltica.

Examination of the site amplification factor of OBS and their application to magnitude estimation and ground-motion prediction for EEW

NASA Astrophysics Data System (ADS)

Hayashimoto, N.; Hoshiba, M.

2013-12-01

1. Introduction Ocean bottom seismograph (OBS) is useful for making Earthquake Early Warning (EEW) earlier. However, careful handling of these data is required because the installation environment of OBSs may be different from that of land stations. Site amplification factor is an important factor to estimate the magnitudes, and to predict ground motions (e.g. seismic intensity) in EEW. In this presentation, we discuss the site amplification factor of OBS in the Tonankai area of Japan from these two points of view. 2. Examination of magnitude correction of OBS In the EEW of JMA, the magnitude is estimated from the maximum amplitude of the displacement in real time. To provide the fast magnitude estimation, the magnitude-estimation algorithm switches from the P to S formula (Meew(P) to Meew(S)) depending on the expected S-phase arrival (Kamigaichi,2004). To estimate the magnitude correction for OBS, we determine Meew(P) and Meew(S) at OBSs and compare them with JMA magnitude (Mjma). We find Meew(S) at OBS is generally larger than Mjma by approximately 0.6. The slight differences of spatial distribution of Meew(S) amplification are also found among other OBSs. From the numerical simulations, Nakamura et al. (MGR,submitted) pointed out that the oceanic layer and the low-velocity sediment layers causes the large amplifications in low frequency range (0.1-0.2Hz) at OBSs. We conclude that the site effect of OBS characterized by such a low velocity sediment layers causes those amplification of Magnitude. 3. The frequency-dependent site factor of OBS estimated from Fourier spectrum ratio and their application for prediction of seismic intensity of land station We compare Fourier spectra of S-wave portion on OBSs with those on adjacent land stations. Station pair whose distance is smaller than 50 km is analyzed, and we obtain that spectral ratio of land station (MIEH05 of the KiK-net/NIED) to OBS (KMA01 of the DONET/JAMSTEC) is 5-20 for frequencies 10-20Hz for both

Irradiated interfaces in the Ara OB1, Carina, Eagle Nebula, and Cyg OB2 massive star formation regions

DOE PAGES

Hartigan, P.; Palmer, J.; Cleeves, L. I.

2012-09-05

Regions of massive star formation offer some of the best and most easily-observed examples of radiation hydrodynamics. Boundaries where fully-ionized H II regions transition to neutral/molecular photodissociation regions (PDRs) are of particular interest because marked temperature and density contrasts across the boundaries lead to evaporative flows and fluid dynamical instabilities that can evolve into spectacular pillar-like structures. Furthermore, when detached from their parent clouds, pillars become ionized globules that often harbor one or more young stars. H2 molecules at the interface between a PDR and an H II region absorb ultraviolet light from massive stars, and the resulting fluoresced infraredmore » emission lines are an ideal way to trace this boundary independent of obscuring dust. This paper presents H2 images of four regions of massive star formation that illustrate different types of PDR boundaries. The Ara OB1 star formation region contains a striking long wall that has several wavy structures which are present in H2, but the emission is not particularly bright because the ambient UV fluxes are relatively low. In contrast, the Carina star formation region shows strong H2 fluorescence both along curved walls and at the edges of spectacular pillars that in some cases have become detached from their parent clouds. The less-spectacular but more well-known Eagle Nebula has two regions that have strong fluorescence in addition to its pillars. And while somewhat older than the other regions, Cyg OB2 has the highest number of massive stars of the regions surveyed and contains many isolated, fluoresced globules that have head–tail morphologies which point towards the sources of ionizing radiation. Our images provide a collection of potential astrophysical analogs that may relate to ablated interfaces observed in laser experiments of radiation hydrodynamics.« less

Uptake and effect of rare earth elements on gene expression in Methylosinus trichosporium OB3b.

PubMed

Gu, Wenyu; Farhan Ul Haque, Muhammad; DiSpirito, Alan A; Semrau, Jeremy D

2016-07-01

It is well known that Methylosinus trichosporium OB3b has two forms of methane monooxygenase (MMO) responsible for the initial conversion of methane to methanol, a cytoplasmic (soluble) methane monooxygenase and a membrane-associated (particulate) methane monooxygenase, and that copper strongly regulates expression of these alternative forms of MMO. More recently, it has been discovered that M. trichosporium OB3b has multiple types of the methanol dehydrogenase (MeDH), i.e. the Mxa-type MeDH (Mxa-MeDH) and Xox-type MeDH (Xox-MeDH), and the expression of these two forms is regulated by the availability of the rare earth element (REE), cerium. Here, we extend these studies and show that lanthanum, praseodymium, neodymium and samarium also regulate expression of alternative forms of MeDH. The effect of these REEs on MeDH expression, however, was only observed in the absence of copper. Further, a mutant of M. trichosporium OB3b, where the Mxa-MeDH was knocked out, was able to grow in the presence of lanthanum, praseodymium and neodymium, but was not able to grow in the presence of samarium. Collectively, these data suggest that multiple levels of gene regulation by metals exist in M. trichosporium OB3b, but that copper overrides the effect of other metals by an as yet unknown mechanism. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Engineering a Business School in a Former Soviet-Era Closed City: The Case of Omsk, Siberia

ERIC Educational Resources Information Center

Chukhlomin, Valeri; Chukhlomina, Irina

2013-01-01

This article describes a modernization project undertaken by a nationally accredited Russian university located in Omsk, Siberia, and aimed at developing a new international business school. A unique feature of the project is that it was successfully implemented in a former Soviet-era closed city. Until 1991, the university hadn't had any…

OB/GYN boot cAMP using high-fidelity human simulators: enhancing residents' perceived competency, confidence in taking a leadership role, and stress hardiness.

PubMed

Pliego, Jose F; Wehbe-Janek, Hania; Rajab, M Hasan; Browning, Jeff L; Fothergill, Russell E

2008-01-01

To evaluate the effectiveness of an obstetrical and gynecologic (Ob/Gyn) Boot Camp simulation training on perceived technical competency, confidence in a leadership role, and stress hardiness of resident training. We conducted a prospective pilot study on the effectiveness of an Ob/Gyn Boot Camp on resident training. Residents participated in an intensive immersion in clinical simulation of common obstetrical emergencies including shoulder dystocia, neonatal resuscitation, postpartum hemorrhage, and ruptured ectopic pregnancy. After the training, residents completed a Web-based survey on their perceptions of how the Ob/Gyn Boot Camp affected their 1) technical competency in the assessment and management of their patients, 2) confidence in taking a leadership role, and 3) stress hardiness. Residents rated their perceptions on a Likert scale of 1 to 5, 1 = poor to 5 = excellent. Twenty-three (14 Ob/Gyn and 9 family medicine) residents participated in this pilot study. Eighteen (78%) residents completed the online survey; 4 Ob/Gyn and 1 family medicine resident did not complete the survey. The residents reported that the simulation training stimulated an interest in learning key skills for obstetrical and gynecologic emergencies. Ob/Gyn residents reported significant improvement in their perceived technical competence and stress hardiness after the Boot Camp. However both Ob/Gyn and family medicine residents reported no significant improvement of confidence in their leadership abilities during obstetrical emergencies after the Boot Camp. Boot Camp simulation training early in the curriculum has the potential for enhancing residents' self-assessments of confidence, competency, and stress hardiness in managing obstetrical emergencies.

Pest Risk Assessment of the Importation of Larch from Siberia and the Soviet Far East

Treesearch

USDA Forest Service

1991-01-01

Several timber companies in the United States have expressed an interest in importing unprocessed larch logs from Siberia and the Soviet Far East. A variety of exotic forest pests, including insects, nematodes, and fungi, can be transported on or in logs. Many of these organisms can survive in transit and have a high potential to colonize suitable hosts near ports of...

On-farm research in Western Siberia: Potential of adapted management practices for sustainable intensification of crop production systems

NASA Astrophysics Data System (ADS)

Kühling, Insa; Trautz, Dieter

2015-04-01

Western Siberia is of global significance in terms of agricultural production, carbon sequestration and biodiversity preservation. Abandonment of arable land and changes in the use of permanent grasslands were triggered by the dissolution of the Soviet Union in and the following collapse of the state farm system. The peatlands, forests and steppe soils of Western Siberia are one of the most important carbon sinks worldwide. These carbon stocks are, if deteriorated, an important source of radiative forcing even in comparison to anthropogenic emissions. This situation is aggravated by recent and future developments in agricultural land use in the southern part of Western Siberia, in particular in Tyumen province. The increase of drought risk caused by climate change will led to more challenges in these water-limited agricultural production systems. The German-Russian interdisciplinary research project "SASCHA" aims to provide sustainable land management practices to cope with these far-reaching changes for Tyumen province. In particular, on farm scale agricultural strategies are being developed for increased efficiencies in crop production systems. Therefore a 3-factorial field trial with different tillage and seeding operations was installed with spring wheat on 10 ha under practical conditions in 2013. Within all combinations of tillage (no-till/conventional), seed rate (usual/reduced) and seed depth (usual/shallower) various soil parameters as well as plant development and yield components were intensively monitored during the growing seasons. Results after 2-years show significant impacts of the tillage operation on soil moisture and soil temperature. Also a higher trend in nitrogen mineralization could be observed without tillage. Plant development in terms of phenological growth stages took place simultaneously in all variants. Under no-till regime we measured slightly higher grain yields and significant advantages in protein yields. In conjunction with

A M2FS Spectroscopic Study of Low-mass Young Stars in Orion OB1

NASA Astrophysics Data System (ADS)

Kaleida, Catherine C.; Briceno, Cesar; Calvet, Nuria; Mateo, Mario L.; Hernandez, Jesus

2015-01-01

Surveys of pre-main sequence stars in the ~4-10 Myr range provide a window into the decline of the accretion phase of stars and the formation of planets. Nearby star clusters and stellar associations allow for the study of these young stellar populations all the way down to the lowest mass members. One of the best examples of nearby 4-10 Myr old stellar populations is the Orion OB1 association. The CIDA Variability Survey of Orion OB1 (CVSO - Briceño et al. 2001) has used the variability properties of low-mass pre-main-sequence (PMS) stars to identify hundreds of K and M-type stellar members of the Orion OB1 association, a number of them displaying IR-excess emission and thought to be representative of more evolved disk-bearing young stars. Characterizing these young, low-mass objects using spectroscopy is integral to understanding the accretion phase in young stars. We present preliminary results of a spectroscopic survey of candidate and confirmed Orion OB1 low-mass members taken during November 2014 and February 2014 using the Michigan/Magellan Fiber Spectrograph (M2FS), a PI instrument on the Magellan Clay Telescope (PI: M. Matteo). Target fields located in the off-cloud regions of Orion were identified in the CVSO, and observed using the low and high-resolution modes of M2FS. Both low and high-resolution spectra are needed in order to confirm membership and derive masses, ages, kinematics and accretion properties. Initial analysis of these spectra reveal many new K and M-type members of the Orion OB1 association in these low extinction, off-cloud areas. These are the more evolved siblings of the youngest stars still embedded in the molecular clouds, like those in the Orion Nebula Cluster. With membership and spectroscopic indicators of accretion we are building the most comprehensive stellar census of this association, enabling us to derive a robust estimate of the fraction of young stars still accreting at a various ages, a key constraint for the end of

Long-Term Arctic Peatland Dynamics, Vegetation and Climate History of the Pur-Taz Region, Western Siberia

NASA Technical Reports Server (NTRS)

Peteet, Dorothy; Andreev, Andrei; Bardeen, William; Mistretta, Francesca

1998-01-01

Stratigraphic analyses of peat composition, LOI, pollen, spores, macrofossils, charcoal, and AMS ages are used to reconstruct the peatland, vegetation and climatic dynamics in the Pur-Taz region of western Siberia over 5000 years (9300 - 4500 BP). Section stratigraphy shows many changes from shallow lake sediment to different combinations of forested or open sedge, moss, and Equisetum fen and peatland environments. Macrofossil and pollen data indicate that Larix sibirica and Betula pubescens trees were first to arrive, followed by Picea obovata. The dominance of Picea macrofossils 6000-5000 BP in the Pur-Taz peatland along with regional Picea pollen maxima indicate warmer conditions and movement of the spruce treeline northward at this time. The decline of pollen and macrofossils from all of these tree species in uppermost peats suggests a change in the environment less favorable for their growth, perhaps cooler temperatures and/or less moisture. Of major significance is the evidence for old ages of the uppermost peats in this area of Siberia, suggesting a real lack of peat accumulation in recent millennia or recent oxidation of uppermost peat.

[The development and introduction of a rational system for the protection of the personnel in a large enterprise against attack by blood-sucking arthropods in western Siberia].

PubMed

Ermishev, Iu V; Dremova, V P; Stepnov, A P; Semenov, V E

2000-01-01

In the middle Ob River Valley (north and moderate taiga), a large number of bloodsucking dipterans (mosquitoes, blackflies, biting midges, horseflies) are recorded during 90-100 days; the activity of Ixodes persulcatus and their attack on humans are notified during 90-115 days. A package of measures that protect petroleum industrial workers from the attacks of bloodsucking insects and ticks includes the use of protective suits, the treatment of premises with insecticides, the use of repellents, and health education. Protective means for workers should be the items included into the list of expenses on safety measures. Work is done on a cost-accounting principle. The introduced system annually shows a high efficiency (95-98%) in protecting large groups of workers in their working places.

Case Study of Data Mining in Observational Astronomy: The Search for New OB Stars in the Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

Larkin, Cormac; Vink, Jorick; Kalari, Venu; Groh, Jose

2018-01-01

OB stars are the most luminous and massive stars, living short lives and exerting a disproportionate influence on their environments. They are key to understanding progenitors of gravitational wave sources and reionization of the early Universe. To detect new OB stars, we combine photometric catalog data with TLUSTY and ATLAS9 stellar atmospheres. This method is also believed to be sensitive to elusive “stripped” stars, thought to lose their hydrogen envelope through binary interaction.OB stars are intrinsically luminous, so complete populations are assumed for local group galaxies such as the Small Magellanic Cloud. Our findings challenge this, as we find 26 new OB candidates. Spectroscopy of 7 candidates shows a 100% detection rate. Most interestingly, 5 of our candidates are consistent with “stripped” stars.To date only 5 “stripped” candidates have been found serendipitously (e.g. HD 45166) as current methods are not sensitive to them. Our work doubles the sample of detected candidates, highlighting that our approach is the first to identify them in a targeted, systematic way. The finding of “stripped” stars could rewrite our understanding of the early Universe, offering an alternative hypothesis to Wolf-Rayet driven cosmic reionization.

Simulating topographic controls on the abundance of larch forest in eastern Siberia, and its consequences under changing climate

NASA Astrophysics Data System (ADS)

Sato, H.; Kobayashi, H.

2017-12-01

In eastern Siberia, larches (Larix spp.) often exist in pure stands, constructing the world's largest coniferous forest, of which changes can significantly affect the earth's albedo and the global carbon balance. Our previous studies tried to reconstruct this vegetation, aiming to forecast its structures and functions under changing climate (1, 2). In previous studies of simulating vegetation at large geographical scales, the examining area is divided into coarse grid cells such as 0.5 × 0.5 degree resolution, and topographical heterogeneities within each grid cell are just ignored. However, in Siberian larch area, which is located on the environmental edge of existence of forest ecosystem, abundance of larch trees largely depends on topographic condition at the scale of tens to hundreds meters. In our preliminary analysis, we found a quantitative pattern that topographic properties controls the abundance of larch forest via both drought and flooding stresses in eastern Siberia. We, therefore, refined the hydrological sub-model of our dynamic vegetation model SEIB-DGVM, and validated whether the modified model can reconstruct the pattern, examined its impact on the estimation of biomass and vegetation productivity under the current and forecasted future climatic conditions. -- References --1. Sato, H., et al. (2010). "Simulation study of the vegetation structure and function in eastern Siberian larch forests using the individual-based vegetation model SEIB-DGVM." Forest Ecology and Management 259(3): 301-311. 2. Sato, H., et al. (2016). "Endurance of larch forest ecosystems in eastern Siberia under warming trends." Ecology and Evolution

Climate-Induced Mortality of Siberian Pine and Fir in the Lake Baikal Watershed, Siberia

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Im, Sergei T.; Petrova, IIya A.; Golyukov, Alexei S.; Ranson, Kenneth J.; Yagunov, Mikhail N.

2016-01-01

Siberian pine (Pinus sibirica) and fir (Abies sibirica) (so called "dark needle conifers", DNC) showed decreased radial growth increment within the Lake Baikal watershed since the 1980s with increasing mortality recorded since the year 2000. Tree ring width was strongly correlated with vapor pressure deficit, aridity and root zone moisture. Water stress from droughts made trees more susceptible to insect attacks causing mortality in about 10% of DNC stands within the Lake Baikal watershed. Within Siberia DNC mortality increased in the southern part of the DNC range. Biogeographically, tree mortality was located within the DNC - forest-steppes transition. Tree mortality was significantly correlated with drought and soil moisture anomalies. Within the interior of the DNC range mortality occurred within relief features with high water stress risk (i.e., steep convex south facing slopes with shallow well-drained soils). In general, DNC mortality in Siberia was induced by increased aridity and severe drought (inciting factors) in synergy with biotic attacks (contributing factor). In future climate scenarios with predicted increase in aridity DNC could be eliminated from the southern part of its current range and will be replaced by drought-resistant conifers and broadleaf species (e.g., Larix sibirica, Pinus silvestris, and Betula pubescence).

Climate-Induced Mortality of Siberian Pine and Fir in the Lake Baikal Watershed, Siberia

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Im, Sergei T.; Petrov, Ilya A.; Golyukov, Alexei S.; Ranson, Kenneth J.; Yagunov, Mikhail N.

2016-01-01

Siberian pine (Pinus sibirica) and fir (Abies sibirica) (so called ''dark needle conifers", DNC) showed decreased radial growth increment within the Lake Baikal watershed since the 1980s with increasing mortality recorded since the year 2000. Tree ring width was strongly correlated with vapor pressure deficit, aridity and root zone moisture. Water stress from droughts made trees more susceptible to insect attacks causing mortality in about 10% of DNC stands within the Lake Baikal watershed. Within Siberia DNC mortality increased in the southern part of the DNC range. Biogeographically, tree mortality was located within the DNC - forest-steppes transition. Tree mortality was significantly correlated with drought and soil moisture anomalies. Within the interior of the DNC range mortality occurred within relief features with high water stress risk (i.e., steep convex south facing slopes with shallow well-drained soils). In general, DNC mortality in Siberia was induced by increased aridity and severe drought (inciting factors) in synergy with biotic attacks (contributing factor). In future climate scenarios with predicted increase in aridity DNC could be eliminated from the southern part of its current range and will be replaced by drought-resistant conifers and broadleaf species (e.g., Larix sibirica, Pinus silvestris, and Betula pubescence).

Pan-Arctic river discharge: Prioritizing monitoring of future climate change hot spots

NASA Astrophysics Data System (ADS)

Bring, Arvid; Shiklomanov, Alexander; Lammers, Richard B.

2017-01-01

The Arctic freshwater cycle is changing rapidly, which will require adequate monitoring of river flows to detect, observe, and understand changes and provide adaptation information. There has, however, been little detail about where the greatest flow changes are projected, and where monitoring therefore may need to be strengthened. In this study, we used a set of recent climate model runs and an advanced macro-scale hydrological model to analyze how flows across the continental pan-Arctic are projected to change and where the climate models agree on significant changes. We also developed a method to identify where monitoring stations should be placed to observe these significant changes, and compared this set of suggested locations with the existing network of monitoring stations. Overall, our results reinforce earlier indications of large increases in flow over much of the Arctic, but we also identify some areas where projections agree on significant changes but disagree on the sign of change. For monitoring, central and eastern Siberia, Alaska, and central Canada are hot spots for the highest changes. To take advantage of existing networks, a number of stations across central Canada and western and central Siberia could form a prioritized set. Further development of model representation of high-latitude hydrology would improve confidence in the areas we identify here. Nevertheless, ongoing observation programs may consider these suggested locations in efforts to improve monitoring of the rapidly changing Arctic freshwater cycle.

Pan-Arctic River Discharge: Where Can We Improve Monitoring of Future Change?

NASA Astrophysics Data System (ADS)

Bring, A.; Shiklomanov, A. I.; Lammers, R. B.

2016-12-01

The Arctic freshwater cycle is changing rapidly, which will require adequate monitoring of river flow to detect, observe and understand changes and provide adaptation information. There has however been little detail about where the greatest flow changes are projected, and where monitoring therefore may need to be strengthened. In this study, we used a set of recent climate model runs and an advanced macro-scale hydrological model to analyze how flows across the continental pan-Arctic are projected to change, and where the climate models agree on significant changes. We also developed a method to identify where monitoring stations should be placed to observe these significant changes, and compared this set of suggested locations with the existing network of monitoring stations. Overall, our results reinforce earlier indications of large increases in flow over much of the Arctic, but we also identify some areas where projections agree on significant changes but disagree on the sign of change. For monitoring, central and eastern Siberia, Alaska and central Canada are hot spots for the highest changes. To take advantage of existing networks, a number of stations across central Canada and western and central Siberia could form a prioritized set. Further development of model representation of high-latitude hydrology would improve confidence in the areas we identify here. Nevertheless, ongoing observation programs may consider these suggested locations in efforts to improve monitoring of the rapidly changing Arctic freshwater cycle.

A model for the infrared emission from an OB star cluster environment

NASA Technical Reports Server (NTRS)

Leisawitz, D.

1991-01-01

A model for the infrared emission from the neighborhood of an OB star cluster is described. The distribution of gas and dust around the stars, properties of the dust, and the cluster and interstellar radiation fields are variable. The model can be applied to regions around clusters embedded to various degrees in their parental molecular clouds (i.e., compact H II regions, blister-type H II regions, and the tenuous H II regions ionized by naked O stars). The model is used to simulate IRAS observations of a typical blister H II region. Infrared surface brightness and spectral energy distributions are predicted and the impact of limited spatial resolution is illustrated. The model results are shown to be consistent with observations of the exemplary outer Galaxy OB cluster NGC 7380. It is planned to use the model as a diagnostic tool to probe the physical conditions and dust properties in star-formation regions and, ultimately, in an interpretation of the spectral energy distributions of spiral galaxies.

Wavelength assignment algorithm considering the state of neighborhood links for OBS networks

NASA Astrophysics Data System (ADS)

Tanaka, Yu; Hirota, Yusuke; Tode, Hideki; Murakami, Koso

2005-10-01

Recently, Optical WDM technology is introduced into backbone networks. On the other hand, as the future optical switching scheme, Optical Burst Switching (OBS) systems become a realistic solution. OBS systems do not consider buffering in intermediate nodes. Thus, it is an important issue to avoid overlapping wavelength reservation between partially interfered paths. To solve this problem, so far, the wavelength assignment scheme which has priority management tables has been proposed. This method achieves the reduction of burst blocking probability. However, this priority management table requires huge memory space. In this paper, we propose a wavelength assignment algorithm that reduces both the number of priority management tables and burst blocking probability. To reduce priority management tables, we allocate and manage them for each link. To reduce burst blocking probability, our method announces information about the change of their priorities to intermediate nodes. We evaluate its performance in terms of the burst blocking probability and the reduction rate of priority management tables.

Origin of elemental carbon in snow from western Siberia and northwestern European Russia during winter-spring 2014, 2015 and 2016

NASA Astrophysics Data System (ADS)

Evangeliou, Nikolaos; Shevchenko, Vladimir P.; Espen Yttri, Karl; Eckhardt, Sabine; Sollum, Espen; Pokrovsky, Oleg S.; Kobelev, Vasily O.; Korobov, Vladimir B.; Lobanov, Andrey A.; Starodymova, Dina P.; Vorobiev, Sergey N.; Thompson, Rona L.; Stohl, Andreas

2018-01-01

Short-lived climate forcers have been proven important both for the climate and human health. In particular, black carbon (BC) is an important climate forcer both as an aerosol and when deposited on snow and ice surface because of its strong light absorption. This paper presents measurements of elemental carbon (EC; a measurement-based definition of BC) in snow collected from western Siberia and northwestern European Russia during 2014, 2015 and 2016. The Russian Arctic is of great interest to the scientific community due to the large uncertainty of emission sources there. We have determined the major contributing sources of BC in snow in western Siberia and northwestern European Russia using a Lagrangian atmospheric transport model. For the first time, we use a recently developed feature that calculates deposition in backward (so-called retroplume) simulations allowing estimation of the specific locations of sources that contribute to the deposited mass. EC concentrations in snow from western Siberia and northwestern European Russia were highly variable depending on the sampling location. Modelled BC and measured EC were moderately correlated (R = 0.53-0.83) and a systematic region-specific model underestimation was found. The model underestimated observations by 42 % (RMSE = 49 ng g-1) in 2014, 48 % (RMSE = 37 ng g-1) in 2015 and 27 % (RMSE = 43 ng g-1) in 2016. For EC sampled in northwestern European Russia the underestimation by the model was smaller (fractional bias, FB > -100 %). In this region, the major sources were transportation activities and domestic combustion in Finland. When sampling shifted to western Siberia, the model underestimation was more significant (FB < -100 %). There, the sources included emissions from gas flaring as a major contributor to snow BC. The accuracy of the model calculations was also evaluated using two independent datasets of BC measurements in snow covering the entire Arctic. The model underestimated BC concentrations in

High-Resolution Regional Biomass Map of Siberia from Glas, Palsar L-Band Radar and Landsat Vcf Data

NASA Astrophysics Data System (ADS)

Sun, G.; Ranson, K.; Montesano, P.; Zhang, Z.; Kharuk, V.

2015-12-01

The Arctic-Boreal zone is known be warming at an accelerated rate relative to other biomes. The taiga or boreal forest covers over 16 x106 km2 of Arctic North America, Scandinavia, and Eurasia. A large part of the northern Boreal forests are in Russia's Siberia, as area with recent accelerated climate warming. During the last two decades we have been working on characterization of boreal forests in north-central Siberia using field and satellite measurements. We have published results of circumpolar biomass using field plots, airborne (PALS, ACTM) and spaceborne (GLAS) lidar data with ASTER DEM, LANDSAT and MODIS land cover classification, MODIS burned area and WWF's ecoregion map. Researchers from ESA and Russia have also been working on biomass (or growing stock) mapping in Siberia. For example, they developed a pan-boreal growing stock volume map at 1-kilometer scale using hyper-temporal ENVISAT ASAR ScanSAR backscatter data. Using the annual PALSAR mosaics from 2007 to 2010 growing stock volume maps were retrieved based on a supervised random forest regression approach. This method is being used in the ESA/Russia ZAPAS project for Central Siberia Biomass mapping. Spatially specific biomass maps of this region at higher resolution are desired for carbon cycle and climate change studies. In this study, our work focused on improving resolution ( 50 m) of a biomass map based on PALSAR L-band data and Landsat Vegetation Canopy Fraction products. GLAS data were carefully processed and screened using land cover classification, local slope, and acquisition dates. The biomass at remaining footprints was estimated using a model developed from field measurements at GLAS footprints. The GLAS biomass samples were then aggregated into 1 Mg/ha bins of biomass and mean VCF and PALSAR backscatter and textures were calculated for each of these biomass bins. The resulted biomass/signature data was used to train a random forest model for biomass mapping of entire region from 50o

Performance analysis of signaling protocols on OBS switches

NASA Astrophysics Data System (ADS)

Kirci, Pinar; Zaim, A. Halim

2005-10-01

In this paper, Just-In-Time (JIT), Just-Enough-Time (JET) and Horizon signalling schemes for Optical Burst Switched Networks (OBS) are presented. These signaling schemes run over a core dWDM network and a network architecture based on Optical Burst Switches (OBS) is proposed to support IP, ATM and Burst traffic. In IP and ATM traffic several packets are assembled in a single packet called burst and the burst contention is handled by burst dropping. The burst length distribution in IP traffic is arbitrary between 0 and 1, and is fixed in ATM traffic at 0,5. Burst traffic on the other hand is arbitrary between 1 and 5. The Setup and Setup ack length distributions are arbitrary. We apply the Poisson model with rate λ and Self-Similar model with pareto distribution rate α to identify inter-arrival times in these protocols. We consider a communication between a source client node and a destination client node over an ingress and one or more multiple intermediate switches.We use buffering only in the ingress node. The communication is based on single burst connections in which, the connection is set up just before sending a burst and then closed as soon as the burst is sent. Our analysis accounts for several important parameters, including the burst setup, burst setup ack, keepalive messages and the optical switching protocol. We compare the performance of the three signalling schemes on the network under as burst dropping probability under a range of network scenarios.

Energy homeostasis in leptin deficient Lepob/ob mice.

PubMed

Skowronski, Alicja A; Ravussin, Yann; Leibel, Rudolph L; LeDuc, Charles A

2017-01-01

Maintenance of reduced body weight is associated both with reduced energy expenditure per unit metabolic mass and increased hunger in mice and humans. Lowered circulating leptin concentration, due to decreased fat mass, provides a primary signal for this response. However, leptin deficient (Lepob/ob) mice (and leptin receptor deficient Zucker rats) reduce energy expenditure following weight reduction by a necessarily non-leptin dependent mechanisms. To identify these mechanisms, Lepob/ob mice were fed ad libitum (AL group; n = 21) or restricted to 3 kilocalories of chow per day (CR group, n = 21). After losing 20% of initial weight (in approximately 2 weeks), the CR mice were stabilized at 80% of initial body weight for two weeks by titrated refeeding, and then released from food restriction. CR mice conserved energy (-17% below predicted based on body mass and composition during the day; -52% at night); and, when released to ad libitum feeding, CR mice regained fat and lean mass (to AL levels) within 5 weeks. CR mice did so while their ad libitum caloric intake was equal to that of the AL animals. While calorically restricted, the CR mice had a significantly lower respiratory exchange ratio (RER = 0.89) compared to AL (0.94); after release to ad libitum feeding, RER was significantly higher (1.03) than in the AL group (0.93), consistent with their anabolic state. These results confirm that, in congenitally leptin deficient animals, leptin is not required for compensatory reduction in energy expenditure accompanying weight loss, but suggest that the hyperphagia of the weight-reduced state is leptin-dependent.

Holocene Faunal Trends in West Siberia and Their Causes

NASA Astrophysics Data System (ADS)

Gashev, S. N.; Aleshina, A. O.; Zuban, I. A.; Lupinos, M. Y.; Mardonova, L. B.; Mitropolskiy, M. G.; Selyukov, A. G.; Sorokina, N. V.; Stolbov, V. A.; Shapovalov, S. I.

2017-12-01

Based on an analysis of the transformation of vertebrate and invertebrate fauna of West Siberia in the Holocene, the classification and periodization of the main faunal trends are presented. Against the background of changing environmental conditions, the key regularities of the faunal dynamics, and the ways some species penetrate into the territory of the region and others disappear from the beginning of the Holocene to the present time have been indicated. Three global and four fluctuating trends are identified. The anthropogenic trend is ascertained separately. A conclusion is made about the prevailing causes of these changes, associated primarily with periodic climatic processes of different levels, determined by planetary geological and cosmic cycles. It is emphasized that, in the historical period, anthropogenic factors play a significant role in the regional faunal dynamics.

Use of sediment rating curves and optical backscatter data to characterize sediment transport in the Upper Yuba River watershed, California, 2001-03

USGS Publications Warehouse

Curtis, Jennifer A.; Flint, Lorraine E.; Alpers, Charles N.; Wright, Scott A.; Snyder, Noah P.

2006-01-01

Sediment transport in the upper Yuba River watershed, California, was evaluated from October 2001 through September 2003. This report presents results of a three-year study by the U.S. Geological Survey, in cooperation with the California Ecosystem Restoration Program of the California Bay-Delta Authority and the California Resources Agency. Streamflow and suspended-sediment concentration (SSC) samples were collected at four gaging stations; however, this report focuses on sediment transport at the Middle Yuba River (11410000) and the South Yuba River (11417500) gaging stations. Seasonal suspended-sediment rating curves were developed using a group-average method and non-linear least-squares regression. Bed-load transport relations were used to develop bed-load rating curves, and bed-load measurements were collected to assess the accuracy of these curves. Annual suspended-sediment loads estimated using seasonal SSC rating curves were compared with previously published annual loads estimated using the Graphical Constituent Loading Analysis System (GCLAS). The percent difference ranged from -85 percent to +54 percent and averaged -7.5 percent. During water year 2003 optical backscatter sensors (OBS) were installed to assess event-based suspended-sediment transport. Event-based suspended-sediment loads calculated using seasonal SSC rating curves were compared with loads calculated using calibrated OBS output. The percent difference ranged from +50 percent to -369 percent and averaged -79 percent. The estimated average annual sediment yield at the Middle Yuba River (11410000) gage (5 tons/mi2) was significantly lower than that estimated at the South Yuba River (11417500) gage (14 tons/mi2). In both rivers, bed load represented 1 percent or less of the total annual load throughout the project period. Suspended sediment at the Middle Yuba River (11410000) and South Yuba River (11417500) gages was typically greater than 85 percent silt and clay during water year 2003, and

BOREAS TF-3 NSA-OBS Tower Flux, Meteorological, and Soil Temperature Data

NASA Technical Reports Server (NTRS)

Wofsy, Steven; Sutton, Doug; Goulden, Mike; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor)

2000-01-01

The BOReal Ecosystem-Atmosphere Study Tower Flux (BOREAS TF-3) team collected tower flux, surface meteorological, and soil temperature data at the BOREAS Northern Study Area-Old Black Spruce (NSA-OBS) site continuously from the March 1994 through October 1996. The data are available in tabular ASCII files.

Forest fire plumes sampled above Siberia during YAK-AEROSIB/POLARCAT airborne campaigns: properties and sources

NASA Astrophysics Data System (ADS)

Paris, J.-D.; Nedelec, P.; Stohl, A.; Arshinov, M. Yu.; Belan, B. D.; Ciais, P.

2009-04-01

The composition of the Siberian troposphere remains highly unknown due to a lack of measurements in this area. Siberia is a key region for a quantified understanding of many land-atmosphere exchange processes. As an example, Siberian forest fire emissions are a major extratropical source of CO to the atmosphere. Fire-emitted trace gases and particles are subject to long-range transport and may contribute to pollution of nearby Arctic. However, establishing precise top-down estimates of sources strengths based on satellite or surface network measurements for species such as CO is limited by models' ability to represent sub-grid-scale dynamics associated to the wildfire (pyroconvection) and the injection height of the plume. In an experimental effort to address this issue and to increase our knowledge of the properties of the Siberian troposphere, CO, O3, CO2 and fine particles were measured onboard a research aircraft in the frame of the YAK-AEROSIB project, partially as a contribution to the Summer 2008 POLARCAT programme. Two large scale transects were established over Northern and Central Siberia between 7 and 21 July 2008. The aircraft flight pattern consisted of ramp ascents and descents so as to sample as many vertical profiles as possible. Very high CO concentrations were observed at various altitudes, essentially in Eastern Siberia near Yakutsk and Chokurdakh. The highest concentrations (up to 600ppb) were observed between 2 and 5 km (flight ceiling being at 7km) in very thin layers (few hundreds of m thick). A Lagrangian modelling analysis (FLEXPART) revealed that the aircraft sampled fire plumes from regional fire emissions, east of Yakutsk, after about 2 days of transport. The observed fire plumes are also characterized by anomalies in O3 and excess particle concentrations. These data provide new constraints on our understanding of forest fire plume transport. They also constitute a critical testbench for the models used to assess pyrogenic emissions and

Near-infrared luminescence of Bi2ZnOB2O6:Nd3+/PMMA composite

NASA Astrophysics Data System (ADS)

Jaroszewski, K.; Głuchowski, P.; Chrunik, M.; Jastrząb, R.; Majchrowski, A.; Kasprowicz, D.

2018-01-01

Near-infrared luminescence of a novel polymer composite system: PMMA doped with Bi2ZnOB2O6:Nd3+ microparticles, is reported for the first time. Luminescence properties of Bi2ZnOB2O6:Nd3+/PMMA were analyzed on the basis on excitation and emission spectra as well as fluorescence decay profiles. Excitation spectra monitored at 1062 nm (4F3/2 → 4I11/2) indicate numerous bands related to the optical transition of Nd3+ ions: from the 4I9/2 ground state to the 4D3/2, 2P1/2, 2K15/2, 4G7/2 + 4G9/2, 2K13/2, 4G5/2 + 2G7/2, 2H11/2, 4F9/2, 4F7/2 + 4S3/2, 4F5/2 + 2H9/2, 4F3/2 excited states. Many of them may be utilized to excite near-infrared emission of Nd3+ ions. In particular, distinctive Nd3+ emissions of the 4F3/2 → 4I9/2 and 4F3/2 → 4I11/2 transitions were detected, under excitation at 514 nm. The fluorescence decay profiles monitored at 1062 nm, excited at 514 nm, show relatively long emission lifetime of the 4F3/2 → 4I11/2 transition equal to 85 μs. Raman spectroscopy was used to determine vibrational properties and homogeneity of Bi2ZnOB2O6:Nd3+/PMMA composites. The obtained results suggest that Bi2ZnOB2O6:Nd3+/PMMA composite may be applied as an effective source of near-infrared emission in a new integrated optoelectronic devices.

Analysis of methane biodegradation by Methylosinus trichosporium OB3b

PubMed Central

Rodrigues, Andréa dos Santos; Salgado, Belkis Valdman e Andréa Medeiros

2009-01-01

The microbial oxidation of methane in the atmosphere is performed by methanotrophic bacteria that use methane as a unique source of carbon and energy. The objective of this work consisted of the investigation of the best conditions of methane biodegradation by methanotrophic bacteria Methylosinus trichosporium OB3b that oxidize it to carbon dioxide, and the use of these microorganisms in monitoring methods for methane. The results showed that M. trichosporium OB3b was capable to degrade methane in a more effective way with an initial microorganism concentration of 0.0700 g.L-1, temperature of 30ºC, pH 6.5 and using 1.79 mmol of methane. In these same conditions, there was no bacterial growth when 2.69 mmol of methane was used. The specific rate of microorganism growth, the conversion factor, the efficiency and the volumetric productivity, for the optimized conditions of biodegradation were, respectively, 0.0324 h-1, 0.6830 gcells/gCH4, 73.73% and 2.7732.10-3 gcells/L.h. The final product of methane microbiological degradation, carbon dioxide, was quantified through the use of a commercial electrode, and, through this, the grade of methane conversion in carbon dioxide was calculated. PMID:24031362

Methane and Trichloroethylene Degradation by Methylosinus trichosporium OB3b Expressing Particulate Methane Monooxygenase

PubMed Central

Lontoh, Sonny; Semrau, Jeremy D.

1998-01-01

Whole-cell assays of methane and trichloroethylene (TCE) consumption have been performed on Methylosinus trichosporium OB3b expressing particulate methane monooxygenase (pMMO). From these assays it is apparent that varying the growth concentration of copper causes a change in the kinetics of methane and TCE degradation. For M. trichosporium OB3b, increasing the copper growth concentration from 2.5 to 20 μM caused the maximal degradation rate of methane (Vmax) to decrease from 300 to 82 nmol of methane/min/mg of protein. The methane concentration at half the maximal degradation rate (Ks) also decreased from 62 to 8.3 μM. The pseudo-first-order rate constant for methane, Vmax/Ks, doubled from 4.9 × 10−3 to 9.9 × 10−3 liters/min/mg of protein, however, as the growth concentration of copper increased from 2.5 to 20 μM. TCE degradation by M. trichosporium OB3b was also examined with varying copper and formate concentrations. M. trichosporium OB3b grown with 2.5 μM copper was unable to degrade TCE in both the absence and presence of an exogenous source of reducing equivalents in the form of formate. Cells grown with 20 μM copper, however, were able to degrade TCE regardless of whether formate was provided. Without formate the Vmax for TCE was 2.5 nmol/min/mg of protein, while providing formate increased the Vmax to 4.1 nmol/min/mg of protein. The affinity for TCE also increased with increasing copper, as seen by a change in Ks from 36 to 7.9 μM. Vmax/Ks for TCE degradation by pMMO also increased from 6.9 × 10−5 to 5.2 × 10−4 liters/min/mg of protein with the addition of formate. From these whole-cell studies it is apparent that the amount of copper available is critical in determining the oxidation of substrates in methanotrophs that are expressing only pMMO. PMID:16349516

OB stars at the lowest Local Group metallicity. GTC-OSIRIS observations of Sextans A

NASA Astrophysics Data System (ADS)

Camacho, I.; Garcia, M.; Herrero, A.; Simón-Díaz, S.

2016-01-01

Context. Massive stars play an important role in the chemical and dynamical evolution of the Universe. The first metal-poor stars may have started the reionization of the Universe. To understand these early epochs it is necessary to know the behavior and the physical properties of massive stars in very metal-poor environments. We focus on the massive stellar content of the metal-poor irregular galaxy Sextans A. Aims: Our aim is to find and classify OB stars in Sextans A, so as to later determine accurate stellar parameters of these blue massive stars in this low-metallicity region (Z ~ 0.1 Z⊙). Methods: Using UBV photometry, the reddening-free index Q and GALEX imaging, we built a list of blue massive star candidates in Sextans A. We obtained low-resolution (R ~ 1000) GTC-OSIRIS spectra for a fraction of them and carried out spectral classification. For the confirmed O-stars, we derived preliminary stellar parameters. Results: The target selection criteria and observations were successful and have produced the first spectroscopic atlas of OB-type stars in Sextans A. From the whole sample of 18 observed stars, 12 were classified as early OB-types, including 5 O-stars. The radial velocities of all target stars are in agreement with their Sextans A membership, although three of them show significant deviations. We determined the stellar parameters of the O-type stars using the stellar atmosphere code FASTWIND and revisited the sub-SMC temperature scale. Two of the O-stars are consistent with relatively strong winds and enhanced helium abundances, although results are not conclusive. We discuss the position of the OB stars in the HRD. Initial stellar masses run from slightly below 20 up to 40 solar masses. Conclusions: The target selection method worked well for Sextans A. The stellar temperatures are consistent with findings in other galaxies. Some of the targets deserve follow-up spectroscopy because of indications of a runaway nature, an enhanced helium abundance

Dynamical Downscaling over Siberia: Is there an added value in representing recent climate conditions?

NASA Astrophysics Data System (ADS)

Klehmet, K.; Rockel, B.

2012-04-01

The analysis of long-term changes and variability of climate variables for the large areal extent of Siberia - covering arctic, subarctic and temperate northern latitudes - is hampered by the sparseness of in-situ observations. To counteract this deficiency we aimed to provide a reconstruction of regional climate for the period 1948-2010 getting homogenous, consistent fields of various terrestrial and atmospheric parameters for Siberia. In order to obtain in addition a higher temporal and spatial resolution than global datasets can provide, we performed the reconstruction using the regional climate model COSMO-CLM (climate mode of the limited area model COSMO developed by the German weather service). However, the question arises whether the dynamically downscaled data of reanalysis can improve the representation of recent climate conditions. As global forcing for the initialization and the regional boundaries we use NCEP-1 Reanalysis of the National Centers for Environmental Prediction since it has the longest temporal data coverage among the reanalysis products. Additionally, spectral nudging is applied to prevent the regional model from deviating from the prescribed large-scale circulation within the whole simulation domain. The area of interest covers a region in Siberia, spanning from the Laptev Sea and Kara Sea to Northern Mongolia and from the West Siberian Lowland to the border of Sea of Okhotsk. The current horizontal resolution is of about 50 km which is planned to be increased to 25 km. To answer the question, we investigate spatial and temporal characteristics of temperature and precipitation of the model output in comparison to global reanalysis data (NCEP-1, ERA40, ERA-Interim). As reference Russian station data from the "Global Summary of the Day" data set, provided by NCDC, is used. Temperature is analyzed with respect to its climatologically spatial patterns across the model domain and its variability of extremes based on climate indices derived

Medium resolution spectroscopy of the supergiant O31f Cyg OB2 No. 7

NASA Astrophysics Data System (ADS)

Maryeva, O. V.; Zhuchkov, R. Ya.

2012-09-01

We examine the feasibility of using medium resolution spectra for determining the parameters of the atmospheres of hot stars by means of numerical simulations. We chose the star Cyg OB2 No. 7 as a test object and obtained its spectrum (λ/Δλ = 2500) with the Russian-Turkish RTT150 telescope. The CMFGEN code was used to construct a model of the atmosphere of Cyg OB2 No. 7. For the first time we have detected the NIV λλ7103.-2-7129.2 lines in the spectrum of this star and used them to determine the physical parameters of the wind. The rate of mass loss measured using the Hα line exceeds the loss rate measured using lines from the wind. This indicates that the wind is nonuniform, apparently owing to rotation.

Climate-Induced Landslides within the Larch Dominant Permafrost Zone of Central Siberia.

PubMed

Kharuk, Viacheslav I; Shushpanov, Alexandr S; Im, Sergei T; Ranson, Kenneth J

2016-04-01

Climate impact on landslide occurrence and spatial patterns were analyzed within the larch-dominant communities associated with continuous permafrost areas of Central Siberia. We used high resolution satellite imagery (i.e. QuickBird, WorldView) to identify landslide scars over an area of 62000 km 2 . Landslide occurrence was analyzed with respect to climate variables (air temperature, precipitation, drought index SPEI), and GRACE satellite derived equivalent of water thickness anomalies (EWTA). Landslides were found only on southward facing slopes, and the occurrence of landslides increased exponentially with increasing slope steepness. Lengths of landslides correlated positively with slope steepness. The observed upper elevation limit of landslides tended to coincide with the tree line. Observations revealed landslides occurrence was also found to be strongly correlated with August precipitation (r = 0.81) and drought index (r = 0.7), with June-July-August soil water anomalies (i.e., EWTA, r = 0.68-0.7), and number of thawing days (i.e., a number of days with t max > 0°C; r = 0.67). A significant increase in the variance of soil water anomalies was observed, indicating that occurrence of landslides may increase even with a stable mean precipitation level. The key-findings of this study are (1) landslides occurrence increased within the permafrost zone of Central Siberia in the beginning of the 21st century; (2) the main cause of increased landslides occurrence are extremes in precipitation and soil water anomalies; and (3) landslides occurrence are strongly dependent on relief features such as southward facing steep slopes.

Climate-Induced Landsliding within the Larch Dominant Permafrost Zone of Central Siberia

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Shushpanov, Alexandr S.; Im, Sergei T.; Ranson, Kenneth J.

2016-01-01

Climate impact on landslide occurrence and spatial patterns were analyzed within the larch-dominant communities associated with continuous permafrost areas of central Siberia. We used high resolution satellite imagery (i.e. QuickBird, WorldView) to identify landslide scars over an area of 62 000 km2. Landslide occurrence was analyzed with respect to climate variables (air temperature, precipitation, drought index SPEI), and Gravity Recovery and Climate Experiment satellite derived equivalent of water thickness anomalies (EWTA). Landslides were found only on southward facing slopes, and the occurrence of landslides increased exponentially with increasing slope steepness. Lengths of landslides correlated positively with slope steepness. The observed upper elevation limit of landslides tended to coincide with the tree line. Observations revealed landslides occurrence was also found to be strongly correlated with August precipitation (r = 0.81) and drought index (r = 0.7), with June-July-August soil water anomalies (i.e., EWTA, r = 0.68-0.7), and number of thawing days (i.e., a number of days with t (max) > 0 deg C; r = 0.67). A significant increase in the variance of soil water anomalies was observed, indicating that occurrence of landslides may increase even with a stable mean precipitation level. The key-findings of this study are (1) landslides occurrence increased within the permafrost zone of central Siberia in the beginning of the 21st century; (2) the main cause of increased landslides occurrence are extremes in precipitation and soil water anomalies; and (3) landslides occurrence are strongly dependent on relief features such as southward facing steep slopes.

Climate-Induced Landslides within the Larch Dominant Permafrost Zone of Central Siberia

PubMed Central

Shushpanov, Alexandr S; Im, Sergei T; Ranson, Kenneth J

2017-01-01

Climate impact on landslide occurrence and spatial patterns were analyzed within the larch-dominant communities associated with continuous permafrost areas of Central Siberia. We used high resolution satellite imagery (i.e. QuickBird, WorldView) to identify landslide scars over an area of 62000 km2. Landslide occurrence was analyzed with respect to climate variables (air temperature, precipitation, drought index SPEI), and GRACE satellite derived equivalent of water thickness anomalies (EWTA). Landslides were found only on southward facing slopes, and the occurrence of landslides increased exponentially with increasing slope steepness. Lengths of landslides correlated positively with slope steepness. The observed upper elevation limit of landslides tended to coincide with the tree line. Observations revealed landslides occurrence was also found to be strongly correlated with August precipitation (r = 0.81) and drought index (r = 0.7), with June-July-August soil water anomalies (i.e., EWTA, r = 0.68–0.7), and number of thawing days (i.e., a number of days with tmax > 0°C; r = 0.67). A significant increase in the variance of soil water anomalies was observed, indicating that occurrence of landslides may increase even with a stable mean precipitation level. The key-findings of this study are (1) landslides occurrence increased within the permafrost zone of Central Siberia in the beginning of the 21st century; (2) the main cause of increased landslides occurrence are extremes in precipitation and soil water anomalies; and (3) landslides occurrence are strongly dependent on relief features such as southward facing steep slopes. PMID:29326754

EDITORIAL: Siberia Integrated Regional Study: multidisciplinary investigations of the dynamic relationship between the Siberian environment and global climate change

NASA Astrophysics Data System (ADS)

Gordov, E. P.; Vaganov, E. A.

2010-03-01

] Groisman P Y et al 2009 The Northern Eurasia Earth Science Partnership: an example of science applied to societal needs Bull. Am. Meteorol. Soc. 90 671-88 [6] Shiklomanov and Lammers R L 2009 Record Russian river discharge in 2007 and the limits of analysis Environ. Res. Lett. 4 045015 [7] Tchebakova N M, Parfenova E and Soja A J 2009 The effects of climate, permafrost and fire on vegetation change in Siberia in a changing climate Environ. Res. Lett. 4 045013 [8] Soja A et al 2007 Climate-induced boreal forest change: predictions versus current observations Global Planet. Change 56 274-96 [9] Groisman P Y and Bartalev S V 2007 Northern Eurasia Earth Science Partnership Initiative (NEESPI): science plan overview Global Planet. Change 56 215-34 [10] Gordov E P and Begni G 2005 Siberia integrated regional study development Comput. Technol. 10 149-55 [11] Gordov E P, Begni G, Heiman M, Kabanov M V, Lykossov V N, Shvidenko A Z and Vaganov E A 2006 Siberia integrated regional study as a basis for international scientific cooperation Comput. Technol. 11 16-28 [12] Baklanov A and Gordov E P 2006 Man-induced environmental risks: monitoring, management and remediation of man-made changes in Siberia Comput. Technol. 11 162-71 [13] Gordov E P 2004 Computational and information technologies for environmental sciences Comput. Technol. 9 3-10 Gordov E P 2004 Modern tendencies in regional environmental studies Geogr. Nat. Resources. (special issue) 11-18 Akhlyostin A Yu and Fazliev A Z 2003 Software for presentation of scientific information in the framework of a WEB portal Proc. SPIE 5396 111-8 Gordov E P, De Rudder A, Lykosov V N, Fazliev A Z and Fedra K 2004 Web-portal ATMOS as basis for integrated investigations of Siberia environment Comput. Technol. 9 3-13 Gordov E P, Lykosov V N and Fazliev A Z 2006 Web portal on environmental sciences 'ATMOS' Adv. Geosci. 8 33-8 Okladnikov I G and Titov A G 2006 Web-system for processing and visualization of meteorological data Environmental

The Shawmere anorthosite and OB-1 as lunar highland regolith simulants

NASA Astrophysics Data System (ADS)

Battler, Melissa M.; Spray, John G.

2009-12-01

Anorthosite constitutes a major component of the lunar crust and comprises an important, if not dominant, ingredient of the lunar regolith. Given the need for highland regolith simulants in preparation for lunar surface engineering activities, we have selected an appropriate terrestrial anorthosite and performed crushing trials to generate a particle size distribution comparable to Apollo 16 regolith sample 64 500. The root simulant is derived from a granoblastic facies of the Archean Shawmere Complex of the Kapuskasing Structural Zone of Ontario, Canada. The Shawmere exhibits minimal retrogression, is homogeneous and has an average plagioclase composition of An 78 (bytownite). Previous industrial interest in this calcic anorthosite has resulted in quarrying operations, which provide ease of extraction and access for potential large-scale simulant production. A derivative of the Shawmere involves the addition of olivine slag, crushed to yield a particle size distribution similar to that of the agglutinate and glass components of the Apollo sample. This simulant is referred to as OB-1. The Shawmere and OB-1 regolith simulants are lunar highland analogues, conceived to produce geotechnical properties of benefit to designing and testing drilling, excavation and construction equipment for future lunar surface operations.

Using MODIS and GLAS Data to Develop Timber Volume Estimates in Central Siberia

NASA Technical Reports Server (NTRS)

Ranson, K. Jon; Kimes, Daniel; Sun, Guoqing; Kharuk, Viatcheslav; Hyde, Peter; Nelson, Ross

2007-01-01

The boreal forest is the Earth's largest terrestrial biome, covering some 12 million km2 and accounting for about one third of this planet's total forest area. Mapping of boreal forest's type, structure parameters and biomass are critical for understanding the boreal forest's significance in the carbon cycle, its response to and impact on global climate change. Ground based forest inventories, have much uncertainty in the inventory data, particularly in remote areas of Siberia where sampling is sparse and/or lacking. In addition, many of the forest inventories that do exist for Siberia are now a decade or more old. Thus, available forest inventories fail to capture the current conditions. Changes in forest structure in a particular forest-type and region can change significantly due to changing environment conditions, and natural and anthropogenic disturbance. Remote sensing methods can potentially overcome these problems. Multispectral sensors can be used to provide vegetation cover maps that show a timely and accurate geographic distribution of vegetation types rather than decade old ground based maps. Lidar sensors can be used to directly obtain measurements that can be used to derive critical forest structure information (e.g., height, density, and volume). These in turn can used to estimate biomass components using allometric equations without having to use out dated forest inventory. Finally, remote sensing data is ideally suited to provide a sampling basis for a rigorous statistical estimate of the variance and error bound on forest structure measures. In this study, new remote sensing methods were applied to develop estimates timber volume using NASA's MODerate resolution Imaging Spectroradiometer (MODIS) and unique waveform data of the geoscience laser altimeter system (GLAS) for a 10 deg x 10 deg area in central Siberia. Using MODIS and GLAS data, maps were produced for cover type and timber volume for 2003, and a realistic variance (error bound) for

Analyzing the Effects of Nitrogen Deficiency on the PHB Production of Methylosinus trichosporium OB3b

NASA Astrophysics Data System (ADS)

Kyauk, E.

2011-12-01

Polyhydroxybutyrate (PHB) is a biodegradable thermoplastic that is produced by various microorganisms. Because of its potential to replace conventional plastics, it has been closely researched in the past few years. Methanotrophic bacteria, bacteria that consume methane, produce this bioplastic when it lacks certain nutrients. The utilization of methane to produce PHB shows much promise as methane is a cheap, plentiful gas. In this study, we observed the methanotroph, Methylosinus trichosporium OB3b , and its yield of PHB in the absence of nitrogen. The optical density of Methylosinus trichosporium OB3b was measured in order to observe cell growth and PHB production patterns over a 48 hour period.

Transcriptome profiling of visceral adipose tissue in a novel obese rat model, WNIN/Ob & its comparison with other animal models.

PubMed

Sakamuri, Siva Sankara Vara Prasad; Putcha, Uday Kumar; Veettil, Giridharan Nappan; Ayyalasomayajula, Vajreswari

2016-09-01

Adipose tissue dysfunction in obesity is linked to the development of type 2 diabetes and cardiovascular diseases. We studied the differential gene expression in retroperitoneal adipose tissue of a novel obese rat model, WNIN/Ob, to understand the possible underlying transcriptional changes involved in the development of obesity and associatedcomorbidities in this model. Four month old, male WNIN/Ob lean and obese rats were taken, blood was collected and tissues were dissected. Body composition analysis and adipose tissue histology were performed. Global gene expression in retroperitoneal adipose tissue of lean and obese rats was studied by microarray using Affymetrix GeneChips. One thousand and seventeen probe sets were downregulated and 963 probe sets were upregulated (more than two-fold) in adipose tissue of WNIN/Ob obese rats when compared to that of lean rats. Small nucleolar RNA (SnoRNA) made most of the underexpressed probe sets, whereas immune system-related genes werethe most overexpressed in the adipose tissues of obese rats. Genes coding for cytoskeletal proteinswere downregulated, whereas genes related to lipid biosynthesis were elevated in the adipose tissue of obese rats. Majority of the altered genes and pathways in adipose tissue of WNIN/Ob obese rats were similar to the observations in other obese animal models and human obesity. Based on these observations, it is proposed that WNIN/Ob obese rat model may be a good model to study the mechanisms involved in the development of obesity and its comorbidities. Downregulation of SnoRNA appears to be a novel feature in this obese rat model.

Ecologically Safe Geothermal Energy Resources in Western Siberia near high-rise construction zones

NASA Astrophysics Data System (ADS)

Shevchenko, Alexandr; Shiganova, Olga

2018-03-01

The development of geothermal energy in combination with other renewable energy sources (the sun, the wind) will help to solve the problem of heat supply and electrification in near high-rise construction zones of the country, especially in sparsely populated parts, where centralized energy and heat supply is economically unacceptable, and will improve the ecological situation. The aim of the research is to analyze the geothermal resources of the main aquifers in Western Siberia and to develop recommendations for further study and use of heat and power resources of this territory. The article gives retrospective of state research programs and potential use of hydrothermal resources of administrative units geographically entering the territory under consideration. It is noted that by now such programs have been curtailed for various reasons, although there are examples of their successful and effective use in various fields of industry and agriculture. According to the decision of the Supreme Ecological Council of the State Duma Committee of the Russian Federation adopted in 2014 on the beginning of the development of federal targeted programs for the use of heat power water as a source of electricity and heat supply, the Ministry of Natural Resources and Ecology of the Russian Federation made proposals for further research and use of hydrothermal waters in Western Siberia. Implementation of the programs proposed by the authors, alongside with other positive aspects, will solve the problems of heat supply in remote territories and improve the environmental situation in the region.

A Search for Pulsar Companions to OB Runaway Stars

NASA Technical Reports Server (NTRS)

Kaspi, V. M.

1995-01-01

We have searched for radio pulsar companions to 40 nearby OB runaway stars. Observations were made at 474 and 770 MHz with the NRAO 140 ft telescope. The survey was sensitive to long- period pulsars with flux densities of 1 mJy or more. One previously unknown pulsar was discovered, PSRJ2044+4614, while observing towards target O star BD+45,3260. Follow-up timing observations of the pulsar measured its position to high precision, revealing a 9' separation between the pulsar and the target star, unequivocally indicating they are not associated.

ObsPy: Establishing and maintaining an open-source community package

NASA Astrophysics Data System (ADS)

Krischer, L.; Megies, T.; Barsch, R.

2017-12-01

Python's ecosystem evolved into one of the most powerful and productive research environment across disciplines. ObsPy (https://obspy.org) is a fully community driven, open-source project dedicated to provide a bridge for seismology into that ecosystem. It does so by offering Read and write support for essentially every commonly used data format in seismology, Integrated access to the largest data centers, web services, and real-time data streams, A powerful signal processing toolbox tuned to the specific needs of seismologists, and Utility functionality like travel time calculations, geodetic functions, and data visualizations. ObsPy has been in constant unfunded development for more than eight years and is developed and used by scientists around the world with successful applications in all branches of seismology. By now around 70 people directly contributed code to ObsPy and we aim to make it a self-sustaining community project.This contributions focusses on several meta aspects of open-source software in science, in particular how we experienced them. During the panel we would like to discuss obvious questions like long-term sustainability with very limited to no funding, insufficient computer science training in many sciences, and gaining hard scientific credits for software development, but also the following questions: How to best deal with the fact that a lot of scientific software is very specialized thus usually solves a complex problem but at the same time can only ever reach a limited pool of developers and users by virtue of it being so specialized? Therefore the "many eyes on the code" approach to develop and improve open-source software only applies in a limited fashion. An initial publication for a significant new scientific software package is fairly straightforward. How to on-board and motivate potential new contributors when they can no longer be lured by a potential co-authorship? When is spending significant time and effort on reusable

Development of the TeamOBS-PPH - targeting clinical performance in postpartum hemorrhage.

PubMed

Brogaard, Lise; Hvidman, Lone; Hinshaw, Kim; Kierkegaard, Ole; Manser, Tanja; Musaeus, Peter; Arafeh, Julie; Daniels, Kay I; Judy, Amy E; Uldbjerg, Niels

2018-06-01

This study aimed to develop a valid and reliable TeamOBS-PPH tool for assessing clinical performance in the management of postpartum hemorrhage (PPH). The tool was evaluated using video-recordings of teams managing PPH in both real-life and simulated settings. A Delphi panel consisting of 12 obstetricians from the UK, Norway, Sweden, Iceland, and Denmark achieved consensus on (i) the elements to include in the assessment tool, (ii) the weighting of each element, and (iii) the final tool. The validity and reliability were evaluated according to Cook and Beckman. (Level 1) Four raters scored four video-recordings of in situ simulations of PPH. (Level 2) Two raters scored 85 video-recordings of real-life teams managing patients with PPH ≥1000 mL in two Danish hospitals. (Level 3) Two raters scored 15 video-recordings of in situ simulations of PPH from a US hospital. The tool was designed with scores from 0 to 100. (Level 1) Teams of novices had a median score of 54 (95% CI 48-60), whereas experienced teams had a median score of 75 (95% CI 71-79; p < 0.001). (Level 2) The intra-rater [intra-class correlation (ICC) = 0.96] and inter-rater (ICC = 0.83) agreements for real-life PPH were strong. The tool was applicable in all cases: atony, retained placenta, and lacerations. (Level 3) The tool was easily adapted to in situ simulation settings in the USA (ICC = 0.86). The TeamOBS-PPH tool appears to be valid and reliable for assessing clinical performance in real-life and simulated settings. The tool will be shared as the free TeamOBS App. © 2018 Nordic Federation of Societies of Obstetrics and Gynecology.

Preventive effect of Silibinin in combination with Pu-erh tea extract on non-alcoholic fatty liver disease in ob/ob mice.

PubMed

Hu, Wen-Yi; Ma, Xiao-Hui; Zhou, Wang-Yi; Li, Xin-Xin; Sun, Ting-Ting; Sun, He

2017-03-22

There are presently no miracle drugs for non-alcoholic fatty liver disease (NAFLD). This study investigates the synergistic effect of Silibinin combined with Pu-erh tea extract (PTE) against NAFLD and explores the suggested mechanism of action. Ob/ob mice were fed a high fat diet along with the oral administration of Silibinin (86 mg per kg per day), PTE (250 mg per kg per day) or their combination for 6 weeks. Their lean littermates who were fed with standard chow diet were used as the control group. The blood biochemical index and histopathological evaluation were analyzed. The expression of genes involved in the lipogenesis pathway and cholesterol metabolism were evaluated. When compared with that of the NAFLD group, the body weight and blood lipid of the mice from the PTE group or combination group were significantly reduced. To some degree, fat metabolism and the inflammatory response were ameliorated by Silibinin and PTE used alone or in combination. It was notable that the combination group had a stronger efficacy in adjusting fat metabolism and inhibiting oxidative stress than that of Silibinin or PTE used alone. Silibinin and PTE inhibited fat synthesis by regulating the mRNA expression of CRTC2, SREBP-1c, and SCD-1. Moreover, the cholesterol homeostasis was improved in the treatment groups via regulating the mRNA expression of ABCA1 and ApoB100. The improvement of the combination group was superior to each drug used alone. In conclusion, Silibinin in combination with PTE can prevent NAFLD with greater potential than Silibinin or PTE used alone and may be a new therapeutic strategy.

Into the Darkness: Interstellar Extinction Near the Cepheus OB3 Molecular Cloud

NASA Astrophysics Data System (ADS)

Fitzpatrick, Edward L.; Jacklin, S.; Massa, D.

2014-01-01

We present the results of a followup investigation to a study performed by Massa and Savage (1984, ApJ, 279, 310) of the properties of UV interstellar extinction in the region of the Cepheus OB3 molecular cloud. That study was performed using UV photometry and spectro-photometry from the ANS and IUE satellites. We have extended this study into the IR, utilizing the uniform database of IR photometry available from the 2MASS project. This is a part of a larger program whose goal is to study the properties of extinction in localized regions, where we hope to find clues to dust grain growth and destruction processes through spatial correlations of extinction with distinct environmental properties. Similarly to Massa and Savage’s UV results, we find that the IR extinction properties on the Cepheus OB3 region vary systematically with the apparent proximity of the target stars to the molecular cloud. We also find that the UV extinction and the IR extinction are crudely correlated. The methodology leading to these results and their implications are discussed.

Optimal Inversion Parameters for Full Waveform Inversion using OBS Data Set

NASA Astrophysics Data System (ADS)

Kim, S.; Chung, W.; Shin, S.; Kim, D.; Lee, D.

2017-12-01

In recent years, full Waveform Inversion (FWI) has been the most researched technique in seismic data processing. It uses the residuals between observed and modeled data as an objective function; thereafter, the final subsurface velocity model is generated through a series of iterations meant to minimize the residuals.Research on FWI has expanded from acoustic media to elastic media. In acoustic media, the subsurface property is defined by P-velocity; however, in elastic media, properties are defined by multiple parameters, such as P-velocity, S-velocity, and density. Further, the elastic media can also be defined by Lamé constants, density or impedance PI, SI; consequently, research is being carried out to ascertain the optimal parameters.From results of advanced exploration equipment and Ocean Bottom Seismic (OBS) survey, it is now possible to obtain multi-component seismic data. However, to perform FWI on these data and generate an accurate subsurface model, it is important to determine optimal inversion parameters among (Vp, Vs, ρ), (λ, μ, ρ), and (PI, SI) in elastic media. In this study, staggered grid finite difference method was applied to simulate OBS survey. As in inversion, l2-norm was set as objective function. Further, the accurate computation of gradient direction was performed using the back-propagation technique and its scaling was done using the Pseudo-hessian matrix.In acoustic media, only Vp is used as the inversion parameter. In contrast, various sets of parameters, such as (Vp, Vs, ρ) and (λ, μ, ρ) can be used to define inversion in elastic media. Therefore, it is important to ascertain the parameter that gives the most accurate result for inversion with OBS data set.In this study, we generated Vp and Vs subsurface models by using (λ, μ, ρ) and (Vp, Vs, ρ) as inversion parameters in every iteration, and compared the final two FWI results.This research was supported by the Basic Research Project(17-3312) of the Korea Institute of

Influence of wildfires in the boreal forests of Eastern Siberia on atmospheric aerosol parameters

NASA Astrophysics Data System (ADS)

Tomshin, Oleg A.; Solovyev, Vladimir S.

2017-11-01

The results of studies of the dynamics of forest fires in the boreal forests of Yakutia (Eastern Siberia) for 2001-2016 are presented. Variations of aerosol optical thickness (AOT), aerosol index (AI) and total carbon monoxide content during May-September were studied depending on the different forest fire activity level. It is shown that the seasonal variations of AOT, AI and CO in the most fire-dangerous years differ significantly from the fire seasons when forest fire activity was medium or low.

Peculiarities of the atmospheric blocking events over the Siberia and Russian Far East region during summertime

NASA Astrophysics Data System (ADS)

Antokhina, Olga Yu.; Devjatova, Elena V.; Mordvinov, Vladimir I.

2017-11-01

We study the atmospheric blocking event evolution peculiarities over the Siberia and Far Eastern region (Russia) during summertime. Compared are two methods to identify blockings: from the 500 hPa (Z500) isobaric surface height distribution, and from the potential temperature at the dynamic tropopause (PV-θ) for every July 1979 through 2016. We revealed the situations, where blockings are identified only in one of the characteristics. Blocking identification by the PV-θ characteristics is complicated in the cases, when its cyclonic part appears to be filled with air masses of the southern origin, due to which there is no meridional gradient reversal in the PV-θ region. In the Z500 region, the difficulties to identify blocking events may arise in those cases, when the baric field fails to adapt to rapid changes in the temperature field associated with the air mass advection. For example, such events often occur over the ocean surface. We performed a synoptic analysis for several blocking events from the data on the velocity field dynamics at 850 hPa and PV-θ supplemented by the analysis of the observational rainfall data at the stations during those events. Distinguished were several stages of the blocking evolution over the Siberia and Far Eastern region that involved air masses from the East Asian summer monsoon region: 1. The formation of a blocking over Western Siberia; 2. Cold inflow on the blocking eastern periphery, the East Asian summer monsoon front activation, and a cyclone formation (east of Lake Baikal), in whose system the monsoon air was actively involved. Such monsoon cyclones, as a rule, are deep long-living formations, and they bring abnormal precipitations; 3. The formation of a ridge or anticyclone east of the monsoon cyclone, caused by the advection of the same monsoon flow, whose part is involved in a cyclone system. In general, the East Asian summer monsoon influence comes to the effects of regeneration and intensification of the blocking

BOREAS TF-9 SSA-OBS Tower Flux, Meteorological, and Soil Temperature Data

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Massheder, Jonathan M.; Moncrieff, John B.; Rayment, Mark B.; Jarvis, Paul G.

2000-01-01

The BOREAS TF-9 team collected energy, carbon dioxide, and water vapor flux data at the BOREAS SSA-OBS site during the growing season of 1994 and most of the year for 1996. From the winter of 1995 to 1996, soil temperature data were also collected and provided. The data are available in tabular ASCII files.

Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines) from the south of Western Siberia, Russia, and Northeastern Kazakhstan.

PubMed

Vasilyan, Davit; Zazhigin, Vladimir S; Böhme, Madelaine

2017-01-01

The present-day amphibian and reptile fauna of Western Siberia are the least diverse of the Palaearctic Realm, as a consequence of the unfavourable climatic conditions that predominate in this region. The origin and emergence of these herpetofaunal groups are poorly understood. Aside from the better-explored European Neogene localities yielding amphibian and reptile fossil remains, the Neogene herpetofauna of Western Asia is understudied. The few available data need critical reviews and new interpretations, taking into account the more recent records of the European herpetofauna. The comparison of this previous data with that of European fossil records would provide data on palaeobiogeographic affiliations of the region as well as on the origin and emergence of the present-day fauna of Western Siberia. An overview of the earliest occurrences of certain amphibian lineages is still needed. In addition, studies that address such knowledge gaps can be useful for molecular biologists in their calibration of molecular clocks. In this study, we considered critically reviewed available data from amphibian and reptile fauna from over 40 Western Siberian, Russian and Northeastern Kazakhstan localities, ranging from the Middle Miocene to Early Pleistocene. Herein, we provided new interpretations that arose from our assessment of the previously published and new data. More than 50 amphibians and reptile taxa were identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae, and Emydidae. Palaeobiogeographic analyses were performed for these groups and palaeoprecipitation values were estimated for 12 localities, using the bioclimatic analysis of herpetofaunal assemblages. The Neogene assemblage of Western Siberia was found to be dominated by groups of European affinities, such as Palaeobatrachidae, Bombina, Hyla , Bufo bufo , and a small part of this assemblage

Sequence-structure mapping errors in the PDB: OB-fold domains

PubMed Central

Venclovas, Česlovas; Ginalski, Krzysztof; Kang, Chulhee

2004-01-01

The Protein Data Bank (PDB) is the single most important repository of structural data for proteins and other biologically relevant molecules. Therefore, it is critically important to keep the PDB data, as much as possible, error-free. In this study, we have analyzed PDB crystal structures possessing oligonucleotide/oligosaccharide binding (OB)-fold, one of the highly populated folds, for the presence of sequence-structure mapping errors. Using energy-based structure quality assessment coupled with sequence analyses, we have found that there are at least five OB-structures in the PDB that have regions where sequences have been incorrectly mapped onto the structure. We have demonstrated that the combination of these computation techniques is effective not only in detecting sequence-structure mapping errors, but also in providing guidance to correct them. Namely, we have used results of computational analysis to direct a revision of X-ray data for one of the PDB entries containing a fairly inconspicuous sequence-structure mapping error. The revised structure has been deposited with the PDB. We suggest use of computational energy assessment and sequence analysis techniques to facilitate structure determination when homologs having known structure are available to use as a reference. Such computational analysis may be useful in either guiding the sequence-structure assignment process or verifying the sequence mapping within poorly defined regions. PMID:15133161

Insights and issues with simulating terrestrial DOC loading of Arctic river networks

USGS Publications Warehouse

Kicklighter, David W.; Hayes, Daniel J.; McClelland, James W.; Peterson, Bruce J.; McGuire, A. David; Melillo, Jerry M.

2013-01-01

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to hydrology. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that, over the 20th century, the pan-Arctic watershed has contributed, on average, 32 Tg C/yr of DOC to river networks emptying into the Arctic Ocean with most of the DOC coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate of terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of climate-induced increases in water yield. These increases have been offset by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to Arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both offset and enhanced concurrent effects on hydrology to influence terrestrial DOC loading and may be changing the relative importance of terrestrial carbon dynamics on this carbon flux. Improvements in simulating terrestrial DOC loading to pan-Arctic rivers in the future will require better information on the production and consumption of DOC within the soil profile, the transfer of DOC from land to headwater streams, the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in western Russia.

[Industrial production of the LDRD "Siberia-N" digital radiographic devices].

PubMed

Baru, S E; Ukraintsev, Iu G

2004-01-01

It is envisaged, as a key task, in the Federal Program on Tuberculosis Monitoring, that preventive measures and early TB detection is a priority. Fluorography, which is important for the recognition of pulmonary tuberculosis at its early stages, has been used in the diagnostics of pulmonary pathologies. However, according to the statistics provided by the Russian Ministry of Healthcare, around 80% of available medical equipment is now worn and obsolete. Owing to a fruitful research activity related with designing a digital low-dose X-Ray unit (Siberia-N) carried out by the Budker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences (Novosibirsk), a certain progress can be stated in perfecting the fluorography equipment in Russia. The above unit incorporates all advanced achievements in the field of digital X-Ray diagnostics.

Future changes in peak river flows across northern Eurasia as inferred from an ensemble of regional climate projections under the IPCC RCP8.5 scenario

NASA Astrophysics Data System (ADS)

Shkolnik, Igor; Pavlova, Tatiana; Efimov, Sergey; Zhuravlev, Sergey

2018-01-01

Climate change simulation based on 30-member ensemble of Voeikov Main Geophysical Observatory RCM (resolution 25 km) for northern Eurasia is used to drive hydrological model CaMa-Flood. Using this modeling framework, we evaluate the uncertainties in the future projection of the peak river discharge and flood hazard by 2050-2059 relative to 1990-1999 under IPCC RCP8.5 scenario. Large ensemble size, along with reasonably high modeling resolution, allows one to efficiently sample natural climate variability and increase our ability to predict future changes in the hydrological extremes. It has been shown that the annual maximum river discharge can almost double by the mid-XXI century in the outlets of major Siberian rivers. In the western regions, there is a weak signal in the river discharge and flood hazard, hardly discernible above climate variability. Annual maximum flood area is projected to increase across Siberia mostly by 2-5% relative to the baseline period. A contribution of natural climate variability at different temporal scales to the uncertainty of ensemble prediction is discussed. The analysis shows that there expected considerable changes in the extreme river discharge probability at locations of the key hydropower facilities. This suggests that the extensive impact studies are required to develop recommendations for maintaining regional energy security.

Batch conversion of methane to methanol using Methylosinus trichosporium OB3b as biocatalyst.

PubMed

Hwang, In Yeub; Hur, Dong Hoon; Lee, Jae Hoon; Park, Chang-Ho; Chang, In Seop; Lee, Jin Won; Lee, Eun Yeol

2015-03-01

Recently, methane has attracted much attention as an alternative carbon feedstock since it is the major component of abundant shale and natural gas. In this work, we produced methanol from methane using whole cells of Methylosinus trichosporium OB3b as the biocatalyst. M. trichosporium OB3b was cultured on NMS medium with a supply of 7:3 air/methane ratio at 30°C. The optimal concentrations of various methanol dehydrogenase inhibitors such as potassium phosphate and EDTA were determined to be 100 and 0.5 mM, respectively, for an efficient production of methanol. Sodium formate (40 mM) as a reducing power source was added to enhance the conversion efficiency. A productivity of 49.0 mg/l·h, titer of 0.393 g methanol/l, and conversion of 73.8% (mol methanol/mol methane) were obtained under the optimized batch condition.

Instability, finite amplitude pulsation and mass-loss in models of massive OB-type stars

NASA Astrophysics Data System (ADS)

Yadav, Abhay Pratap; Glatzel, Wolfgang

2017-11-01

Variability and mass-loss are common phenomena in massive OB-type stars. It is argued that they are caused by violent strange mode instabilities identified in corresponding stellar models. We present a systematic linear stability analysis with respect to radial perturbations of massive OB-type stars with solar chemical composition and masses between 23 and 100 M⊙. For selected unstable stellar models, we perform non-linear simulations of the evolution of the instabilities into the non-linear regime. Finite amplitude pulsations with periods in the range between hours and 100 d are found to be the final result of the instabilities. The pulsations are associated with a mean acoustic luminosity which can be the origin of a pulsationally driven wind. Corresponding mass-loss rates lie in the range between 10-9 and 10-4 M⊙ yr-1 and may thus affect the evolution of massive stars.

Distribution of the P2X2 receptor and chemical coding in ileal enteric neurons of obese male mice (ob/ob)

PubMed Central

Mizuno, Márcia Sanae; Crisma, Amanda Rabello; Borelli, Primavera; Schäfer, Bárbara Tavares; Silveira, Mariana Póvoa; Castelucci, Patricia

2014-01-01

AIM: To investigate the colocalization, density and profile of neuronal areas of enteric neurons in the ileum of male obese mice. METHODS: The small intestinal samples of male mice in an obese group (OG) (C57BL/6J ob/ob) and a control group (CG) (+/+) were used. The tissues were analyzed using a double immunostaining technique for immunoreactivity (ir) of the P2X2 receptor, nitric oxide synthase (NOS), choline acetyl transferase (ChAT) and calretinin (Calr). Also, we investigated the density and profile of neuronal areas of the NOS-, ChAT- and Calr-ir neurons in the myenteric plexus. Myenteric neurons were labeled using an NADH-diaphorase histochemical staining method. RESULTS: The analysis demonstrated that the P2X2 receptor was expressed in the cytoplasm and in the nuclear and cytoplasmic membranes only in the CG. Neuronal density values (neuron/cm2) decreased 31% (CG: 6579 ± 837; OG: 4556 ± 407) and 16.5% (CG: 7796 ± 528; OG: 6513 ± 610) in the NOS-ir and calretinin-ir neurons in the OG, respectively (P < 0.05). Density of ChAT-ir (CG: 6200 ± 310; OG: 8125 ± 749) neurons significantly increased 31% in the OG (P < 0.05). Neuron size studies demonstrated that NOS, ChAT, and Calr-ir neurons did not differ significantly between the CG and OG groups. The examination of NADH-diaphorase-positive myenteric neurons revealed an overall similarity between the OG and CG. CONCLUSION: Obesity may exert its effects by promoting a decrease in P2X2 receptor expression and modifications in the density of the NOS-ir, ChAT-ir and CalR-ir myenteric neurons. PMID:25320527

DNA analysis of a 30,000-year-old Urocitellus glacialis from northeastern Siberia reveals phylogenetic relationships between ancient and present-day arctic ground squirrels

PubMed Central

Faerman, Marina; Bar-Gal, Gila Kahila; Boaretto, Elisabetta; Boeskorov, Gennady G.; Dokuchaev, Nikolai E.; Ermakov, Oleg A.; Golenishchev, Fedor N.; Gubin, Stanislav V.; Mintz, Eugenia; Simonov, Evgeniy; Surin, Vadim L.; Titov, Sergei V.; Zanina, Oksana G.; Formozov, Nikolai A.

2017-01-01

In contrast to the abundant fossil record of arctic ground squirrels, Urocitellus parryii, from eastern Beringia, only a limited number of fossils is known from its western part. In 1946, unnamed GULAG prisoners discovered a nest with three mummified carcasses of arctic ground squirrels in the permafrost sediments of the El’ga river, Yakutia, Russia, that were later attributed to a new species, Citellus (Urocitellus) glacialis Vinogr. To verify this assignment and to explore phylogenetic relationships between ancient and present-day arctic ground squirrels, we performed 14C dating and ancient DNA analyses of one of the El’ga mummies and four contemporaneous fossils from Duvanny Yar, northeastern Yakutia. Phylogenetic reconstructions, based on complete cytochrome b gene sequences of five Late Pleistocene arctic ground squirrels and those of modern U. parryii from 21 locations across western Beringia, provided no support for earlier proposals that ancient arctic ground squirrels from Siberia constitute a distinct species. In fact, we observed genetic continuity of the glacialis mitochondrial DNA lineage in modern U. parryii of the Kamchatka peninsula. When viewed in a broader geographic perspective, our findings provide new insights into the genetic history of U. parryii in Late Pleistocene Beringia. PMID:28205612

Spatial dynamics of thermokarst and thermo-erosion at lakes and ponds in North Siberia and Northwest Alaska using high-resolution remote sensing

NASA Astrophysics Data System (ADS)

Grosse, G.; Tillapaugh, M.; Romanovsky, V. E.; Walter, K. M.; Plug, L. J.

2008-12-01

Formation, growth, and drainage of thermokarst lakes in ice-rich permafrost deposits are important factors of landscape dynamics in extent Arctic lowlands. Monitoring of spatial and temporal dynamics of such lakes will allow an assessment of permafrost stability and enhance the capabilities for modelling and quantifying biogeochemical processes related to permafrost degradation in a warming Arctic. In this study we use high-resolution remote sensing and GIS to analyze the development of thermokarst lakes and ponds in two study regions in North Siberia and Northwest Alaska. The sites are 1) the Cherskii region in the Kolyma lowland (Siberia) and 2) the Kitluk River area on the northern Seward Peninsula (Alaska). Both regions are characterized by continuous permafrost, a highly dissected and dynamic thermokarst landscape, uplands of Late Pleistocene permafrost deposits with high excess ice contents, and a large total volume of permafrost-stored carbon. These ice-rich Yedoma or Yedoma-like deposits are highly vulnerable to permafrost degradation forced by climate warming or other surface disturbance. Time series of high- resolution imagery (aerial, Corona, Ikonos, Alos Prism) covering more than 50 years of lake dynamics allow detailed assessments of processes and spatial patterns of thermokarst lake expansion and drainage in continuous permafrost. Time series of high-resolution imagery (aerial, Corona, Ikonos, Alos Prism) covering more than 50 years of lake dynamics allow detailed assessments of processes and spatial patterns of thermokarst lake expansion and drainage in continuous permafrost. Processes identified include thaw slumping, wave undercutting of frozen sediments or peat blocks and subsequent mass wasting, thaw collapse of near-shore zones, sinkhole formation and ice-wedge tunnelling, and gully formation by thermo-erosion. We use GIS-based tools to relate the remote sensing results to field data (ground ice content, topography, lithology, and relative age

The discovery of low-mass pre-main-sequence stars in Cepheus OB3b

NASA Astrophysics Data System (ADS)

Pozzo, M.; Naylor, T.; Jeffries, R. D.; Drew, J. E.

2003-05-01

We report the discovery of a low-mass pre-main-sequence (PMS) stellar population in the younger subgroup of the Cepheus OB3 association, Cep OB3b, using UBVI CCD photometry and follow-up spectroscopy. The optical survey covers approximately 1300 arcmin2 on the sky and gives a global photometric and astrometric catalogue for more than 7000 objects. The location of a PMS population is well defined in a V versus (V-I) colour-magnitude diagram. Multifibre spectroscopic results for optically selected PMS candidates confirm the T Tauri nature for 10 objects, with equal numbers of classical TTS (CTTS) and weak-line TTS (WTTS). There are six other objects that we classify as possible PMS stars. The newly discovered TTS stars have masses in the range ~0.9-3.0 Msolar and ages from <1 to nearly 10 Myr, based on the Siess, Dufour & Forestini isochrones. Their location close to the O and B stars of the association (especially the O7n star) demonstrates that low-mass star formation is indeed possible in such an apparently hostile environment dominated by early-type stars and that the latter must have been less effective in eroding the circumstellar discs of their lower-mass siblings compared with other OB associations (e.g. λ-Ori). We attribute this to the nature of the local environment, speculating that the bulk of molecular material, which shielded low-mass stars from the ionizing radiation of their early-type siblings, has only recently been removed.

Not all stars form in clusters - measuring the kinematics of OB associations with Gaia

NASA Astrophysics Data System (ADS)

Ward, Jacob L.; Kruijssen, J. M. Diederik

2018-04-01

It is often stated that star clusters are the fundamental units of star formation and that most (if not all) stars form in dense stellar clusters. In this monolithic formation scenario, low-density OB associations are formed from the expansion of gravitationally bound clusters following gas expulsion due to stellar feedback. N-body simulations of this process show that OB associations formed this way retain signs of expansion and elevated radial anisotropy over tens of Myr. However, recent theoretical and observational studies suggest that star formation is a hierarchical process, following the fractal nature of natal molecular clouds and allowing the formation of large-scale associations in situ. We distinguish between these two scenarios by characterizing the kinematics of OB associations using the Tycho-Gaia Astrometric Solution catalogue. To this end, we quantify four key kinematic diagnostics: the number ratio of stars with positive radial velocities to those with negative radial velocities, the median radial velocity, the median radial velocity normalized by the tangential velocity, and the radial anisotropy parameter. Each quantity presents a useful diagnostic of whether the association was more compact in the past. We compare these diagnostics to models representing random motion and the expanding products of monolithic cluster formation. None of these diagnostics show evidence of expansion, either from a single cluster or multiple clusters, and the observed kinematics are better represented by a random velocity distribution. This result favours the hierarchical star formation model in which a minority of stars forms in bound clusters and large-scale, hierarchically structured associations are formed in situ.

New data on stratigraphy (palynomorphs, ostracods, paleomagnetism) of Cenozoic continental deposits of the Ishim plain, Western Siberia

NASA Astrophysics Data System (ADS)

Kuzmina, O. B.; Gnibidenko, Z. N.; Khazin, L. B.; Khazina, I. V.

2017-05-01

New micropaleontological and paleomagnetic data were obtained by studying core samples of Cenozoic continental deposits from two boreholes drilled in the south of Tyumen oblast (Western Siberia). Palynological assemblages in deposits of the Tavda (upper part), Novomikhailovka, Turtas, Abrosimovka, Tobolsk, Smirnovka, and Suzgun formations were described. Deposits of these formations are enriched in spore-pollen assemblages, which can be correlated with assemblages of regional palynozones of the West Siberian Plain. Ostracods were described in Quaternary deposits. On the basis of biostratigraphic and paleomagnetic data, the Late Eocene (Priabonian)-Holocene age of deposits was substantiated. For the first time, beds with dinocysts of genus Pseudokomewuia were identified in deposits of the Turtas Formation (Upper Oligocene) of the Ishim lithofacial area. In total, nine regional magnetozones were distinguished in the paleomagnetic section. On the basis of palynological and paleomagnetic data, sections of two boreholes were correlated, and hiatuses in sedimentation were revealed. A large hiatus is at the Eocene-Oligocene boundary (Western Siberia): the Lower Oligocene Atlym Horizon and Miocene-Pliocene and Eopleistocene sediments are missing. The Oligocene interval of the section is represented in a reduced volume.

Methanobactin from Methylocystis sp. strain SB2 affects gene expression and methane monooxygenase activity in Methylosinus trichosporium OB3b.

PubMed

Farhan Ul-Haque, Muhammad; Kalidass, Bhagyalakshmi; Vorobev, Alexey; Baral, Bipin S; DiSpirito, Alan A; Semrau, Jeremy D

2015-04-01

Methanotrophs can express a cytoplasmic (soluble) methane monooxygenase (sMMO) or membrane-bound (particulate) methane monooxygenase (pMMO). Expression of these MMOs is strongly regulated by the availability of copper. Many methanotrophs have been found to synthesize a novel compound, methanobactin (Mb), that is responsible for the uptake of copper, and methanobactin produced by Methylosinus trichosporium OB3b plays a key role in controlling expression of MMO genes in this strain. As all known forms of methanobactin are structurally similar, it was hypothesized that methanobactin from one methanotroph may alter gene expression in another. When Methylosinus trichosporium OB3b was grown in the presence of 1 μM CuCl2, expression of mmoX, encoding a subunit of the hydroxylase component of sMMO, was very low. mmoX expression increased, however, when methanobactin from Methylocystis sp. strain SB2 (SB2-Mb) was added, as did whole-cell sMMO activity, but there was no significant change in the amount of copper associated with M. trichosporium OB3b. If M. trichosporium OB3b was grown in the absence of CuCl2, the mmoX expression level was high but decreased by several orders of magnitude if copper prebound to SB2-Mb (Cu-SB2-Mb) was added, and biomass-associated copper was increased. Exposure of Methylosinus trichosporium OB3b to SB2-Mb had no effect on expression of mbnA, encoding the polypeptide precursor of methanobactin in either the presence or absence of CuCl2. mbnA expression, however, was reduced when Cu-SB2-Mb was added in both the absence and presence of CuCl2. These data suggest that methanobactin acts as a general signaling molecule in methanotrophs and that methanobactin "piracy" may be commonplace. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Methanobactin from Methylocystis sp. Strain SB2 Affects Gene Expression and Methane Monooxygenase Activity in Methylosinus trichosporium OB3b

PubMed Central

Farhan Ul-Haque, Muhammad; Kalidass, Bhagyalakshmi; Vorobev, Alexey; Baral, Bipin S.; DiSpirito, Alan A.

2015-01-01

Methanotrophs can express a cytoplasmic (soluble) methane monooxygenase (sMMO) or membrane-bound (particulate) methane monooxygenase (pMMO). Expression of these MMOs is strongly regulated by the availability of copper. Many methanotrophs have been found to synthesize a novel compound, methanobactin (Mb), that is responsible for the uptake of copper, and methanobactin produced by Methylosinus trichosporium OB3b plays a key role in controlling expression of MMO genes in this strain. As all known forms of methanobactin are structurally similar, it was hypothesized that methanobactin from one methanotroph may alter gene expression in another. When Methylosinus trichosporium OB3b was grown in the presence of 1 μM CuCl2, expression of mmoX, encoding a subunit of the hydroxylase component of sMMO, was very low. mmoX expression increased, however, when methanobactin from Methylocystis sp. strain SB2 (SB2-Mb) was added, as did whole-cell sMMO activity, but there was no significant change in the amount of copper associated with M. trichosporium OB3b. If M. trichosporium OB3b was grown in the absence of CuCl2, the mmoX expression level was high but decreased by several orders of magnitude if copper prebound to SB2-Mb (Cu-SB2-Mb) was added, and biomass-associated copper was increased. Exposure of Methylosinus trichosporium OB3b to SB2-Mb had no effect on expression of mbnA, encoding the polypeptide precursor of methanobactin in either the presence or absence of CuCl2. mbnA expression, however, was reduced when Cu-SB2-Mb was added in both the absence and presence of CuCl2. These data suggest that methanobactin acts as a general signaling molecule in methanotrophs and that methanobactin “piracy” may be commonplace. PMID:25616801

Experience and Perspectives of Art History Development in Educational Space of Siberia at the Turn of XX-XXI ?enturies

ERIC Educational Resources Information Center

Nekhvyadovich, Larisa Ivanovna; Chernyaeva, Irina Valerievna

2016-01-01

The article has a program-analytical nature, contains an analysis and assessment of the scientific school of T. M. Stepanskaya, Doctor of Arts, professor, member of Russian Union of Artists. The goal of T. M. Stepanskaya's professional activity is incorporation of Art History in higher educational institutions in Siberia. The authors consider the…

Carnosic acid attenuates obesity-induced glucose intolerance and hepatic fat accumulation by modulating genes of lipid metabolism in C57BL/6J-ob/ob mice.

PubMed

Park, Mi-Young; Sung, Mi-Kyung

2015-03-15

Carnosic acid (CA), a major bioactive component of rosemary (Rosmarinus officinalis) leaves, is known to possess antioxidant and anti-adipogenic activities. In this study it was hypothesized that CA would ameliorate obesity-induced glucose intolerence and hepatic fat accumulation, and possible mechanisms are suggested. It was observed that a 0.02% (w/w) CA diet effectively decreased body weight, liver weight and blood triglyceride (TG) and total cholesterol levels (P < 0.05) compared with the control diet. CA at 0.02% significantly improved glucose tolerance, and hepatic TG accumulation was reduced in a dose-dependent manner. Hepatic lipogenic-related gene (L-FABP, SCD1 and FAS) expression decreased whereas lipolysis-related gene (CPT1) expression increased in animals fed the 0.02% CA diet (P < 0.05). Long-chain fatty acid content and the ratio of C18:1/C18:0 fatty acids were decreased in adipose tissue of animals fed the 0.02% CA diet (P < 0.05). Serum inflammatory mediators were also decreased significantly in animals fed the 0.02% CA diet compared with those of the obese control group (P < 0.05). These results suggest that CA is an effective anti-obesity agent that regulates fatty acid metabolism in C57BL/6J-ob/ob mice. © 2014 Society of Chemical Industry.

Analysis of the Seismicity Associated to the Subduction of the Rivera Plate using OBS and Onland Stations.

NASA Astrophysics Data System (ADS)

Nuñez-Cornu, F. J.; Barba, D. C., Sr.; Danobeitia, J.; Bandy, W. L.; Zamora-Camacho, A.; Marquez-Ramirez, V. H.; Ambros, M.; Gomez, A.; Sandoval, J. M.; Mortera-Gutierrez, C. A.

2016-12-01

The second stage of TsuJal Project includes the study of passive seismic activity in the region of the plate Rivera and Jalisco block by anchoring OBS and densifying the network of seismic stations on land for at least four months. This stage began in April 2016 with the deployment of 25 Obsidian stations with sensor Le-3D MkIII from the northern part of Nayarit state to the south of Colima state, including the Marias Islands. This temporal seismic network complements the Jalisco Seismic Network (RESAJ) for a total of 50 stations. Offshore, ten OBS type LCHEAPO 2000 with 4 channel (3 seismic short period and 1 pressure) were deployed, in the period from 19 to 30 April 2016 using the BO El Puma from UNAM. The OBS were deployed in an array from the Marias Islands to offcoast of the border of Colima and Michoacan states. On May 4, an earthquake with Ml = 4.2 took place in the contact area of the Rivera Plate, Cocos Plate and the Middle America Trench, subsequently occurred a seismic swarm with over 200 earthquakes until May 16, including an earthquake with Ml = 5.0 on May 7. A second swarm took place between May 28 and Jun 4 including an earthquake with Ml = 4.8 on Jun 1. An analysis of the quality of different location methods is presented: automatic preliminary RESAJ location using Antelope; location with revised RESAJ phases in Antelope; relocation of RESAJ data with hypo and a regional velocity model; relocation of RESAJ data with hypo adding data from the temporal seismic network stations; and finally the relocation adding the data from the OBS network. Moreover, the tectonic implications of these earthquakes are discussed.

BOREAS TGB-8 Photosynthetic Rate Data over the SSA-OBS and the SSA-OJP

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Lerdau, Manuel

2000-01-01

The BOREAS TGB-8 team collected data to investigate the controls over NMHC fluxes from boreal forest tree species. This data set includes measurements of photosynthetic rates at mature jack pine and black spruce sites. The data were collected at the OJP and OBS tower flux locations in the BOREAS SSA. These areas contained mature stands of jack pine and black spruce and were the focal sites in the BOREAS program for studies of biosphere/atmosphere exchange from these two habitat types. The OBS site is situated in a black spruce/sphagnum bog with the largest trees 155 years old and 10-15 m tall. The OJP site is in a jack pine forest, 80 to 120 years old, which lies on a sandy bench of glacial outwash with the largest tree standing 15 m tall. Temporally, the data cover the period of 24-May-1994 to 19-Sep-1994. The data are stored in tabular ASCII files.

BOREAS TGB-8 Starch Concentration Data Over the SSA-OBS and the SSA-OJP

NASA Technical Reports Server (NTRS)

Lerdau, Manuel; Hall, Forrest G. (Editor); Conrad, Sara K. (Editor)

2000-01-01

The BOREAS TGB-8 team collected data to investigate the controls over NMHC fluxes from boreal forest tree species. This data set includes measurements of starch concentrations in foliar samples at mature jack pine and black spruce sites. The data were collected at the OJP and OBS tower flux locations in the BOREAS SSA. These areas contained mature stands of jack pine and black spruce and were the focal sites in the BOREAS program for studies of biosphere/atmosphere exchange from these two habitat types. The OBS site is situated in a black spruce/sphagnum bog with the largest trees 155 years old and 10-15 m tall. The OJP site is in a jack pine forest, 80 to 120 years old, which lies on a sandy bench of glacial outwash with the largest tree standing 15 m tall. Temporally, the data cover the period of 24-May-1994 to 19-Sep-1994. The data are stored in tabular ASCII files.

Hard X-ray Flux from Low-Mass Stars in the Cygnus OB2 Association

NASA Astrophysics Data System (ADS)

Caramazza, M.; Drake, J. J.; Micela, G.; Flaccomio, E.

2009-05-01

We investigate the X-ray emission in the 20-40 keV band expected from the flaring low-mass stellar population in Cygnus OB2 assuming that the observed soft X-ray emission is due to a superposition of flares and that the ratio of hard X-ray to soft X-ray emission is described by a scaling found for solar flares by Isola and co-workers. We estimate a low-mass stellar hard X-ray flux in the 20-40 keV band in the range ~7×1031-7×1033 erg/s and speculate the limit of this values. Hard X-ray emission could lie at a level not much below the current observed flux upper limits for Cygnus OB2. Simbol-X, with its broad energy band (10-100 keV) and its sensitivity should be able to detect this emission and would provide insights into the hard X-ray production of flares on pre-main sequence stars.

BOREAS TF-8 NSA-OJP and SSA-OBS Ceilometer Data

NASA Technical Reports Server (NTRS)

Moore, Kathleen E.; Hall, Forrest G. (Editor); Huemmrich, Karl (Editor); Fitzjarrald, David R.

2000-01-01

The BOREAS TF-8 team used ceilometers to collect data on the fraction of the sky covered with clouds and the cloud height. Included with these data is the surface-based lifting condensation level, derived from temperature and humidity values acquired at the flux tower at the NSA-OJP site. Ceilo-meter data were collected at the NSA-OJP site in 1994 and at the NSA-OJP and SSA-OBS sites in 1996. The data are available in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884).

Fuel Consumption and Fire Emissions Estimates in Siberia: Impact of Vegetation Types, Meteorological Conditions, Forestry Practices and Fire Regimes

NASA Astrophysics Data System (ADS)

Kukavskaya, Elena; Conard, Susan; Ivanova, Galina; Buryak, Ludmila; Soja, Amber; Zhila, Sergey

2015-04-01

Boreal forests play a crucial role in carbon budgets with Siberian carbon fluxes and pools making a major contribution to the regional and global carbon cycle. Wildfire is the main ecological disturbance in Siberia that leads to changes in forest species composition and structure and in carbon storage, as well as direct emissions of greenhouse gases and aerosols to the atmosphere. At present, the global scientific community is highly interested in quantitative and accurate estimates of fire emissions. Little research on wildland fuel consumption and carbon emission estimates has been carried out in Russia until recently. From 2000 to 2007 we conducted a series of experimental fires of varying fireline intensity in light-coniferous forest of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions due to fires of known behavior. From 2009 to 2013 we examined a number of burned logged areas to assess the potential impact of forest practices on fire emissions. In 2013-2014 burned areas in dark-coniferous and deciduous forests were examined to determine fuel consumption and carbon emissions. We have combined and analyzed the scarce data available in the literature with data obtained in the course of our long-term research to determine the impact of various factors on fuel consumption and to develop models of carbon emissions for different ecosystems of Siberia. Carbon emissions varied drastically (from 0.5 to 40.9 tC/ha) as a function of vegetation type, weather conditions, anthropogenic effects and fire behavior characteristics and periodicity. Our study provides a basis for better understanding of the feedbacks between wildland fire emissions and changing anthropogenic disturbance patterns and climate. The data obtained could be used by air quality agencies to calculate local emissions and by managers to develop strategies to mitigate negative smoke impacts on the environmentand human health.

A multiwavelength investigation of the massive eclipsing binary Cygnus OB2 #5

NASA Astrophysics Data System (ADS)

Linder, N.; Rauw, G.; Manfroid, J.; Damerdji, Y.; De Becker, M.; Eenens, P.; Royer, P.; Vreux, J.-M.

2009-02-01

Context: The properties of the early-type binary Cyg OB2 #5 have been debated for many years and spectroscopic and photometric investigations yielded conflicting results. Aims: We have attempted to constrain the physical properties of the binary by collecting new optical and X-ray observations. Methods: The optical light curves obtained with narrow-band continuum and line-bearing filters are analysed and compared. Optical spectra are used to map the location of the He ii λ 4686 and Hα line-emission regions in velocity space. New XMM-Newton as well as archive X-ray spectra are analysed to search for variability and constrain the properties of the hot plasma in this system. Results: We find that the orbital period of the system slowly changes though we are unable to discriminate between several possible explanations of this trend. The best fit solution of the continuum light curve reveals a contact configuration with the secondary star being significantly brighter and hotter on its leading side facing the primary. The mean temperature of the secondary star turns out to be only slightly lower than that of the primary, whilst the bolometric luminosity ratio is found to be 3.1. The solution of the light curve yields a distance of 925 ± 25 pc much lower than the usually assumed distance of the Cyg OB2 association. Whilst we confirm the existence of episodes of higher X-ray fluxes, the data reveal no phase-locked modulation with the 6.6 day period of the eclipsing binary nor any clear relation between the X-ray flux and the 6.7 yr radio cycle. Conclusions: The bright region of the secondary star is probably heated by energy transfer in a common envelope in this contact binary system as well as by the collision with the primary's wind. The existence of a common photosphere probably also explains the odd mass-luminosity relation of the stars in this system. Most of the X-ray, non-thermal radio, and possibly γ-ray emission of Cyg OB2 #5 is likely to arise from the

Inverse-Ray Imaging of Gas Hydrates Along a MCS/OBS Profile at the Continental Slope Offshore SW Taiwan

NASA Astrophysics Data System (ADS)

Wang, T. K.; Chen, C.; Yang, B.; Lee, C.

2006-12-01

Prevalence of gas hydrates offshore SW Taiwan has been proposed due to lots of bottom-simulated reflectors (BSR) appeared on the seismic data. In this paper, we analyze a MCS/OBS profile with intensive BSR signals at the continental slope of the northern South China Sea. Firstly, MCS data with 160 channels collected by R/V Maurice-Ewing in September 1995 is re-processed through vertical velocity analysis, horizon velocity analysis, and prestack depth migration. Then, OBS data collected by the first Micro-OBS survey from NTOU team in August 2005 is analyzed through travel-time inversion of reflected and refracted arrivals for which the initial model is constructed from the MCS result. Finally, a novel technique of inverse reflected rays by considering both MCS and OBS data is applied for layer-stripping imaging of sedimentary layers. Velocity models imaged from three methods are confirmed the prevalence of BSR at 100-400 m depth below the sea floor along the whole profile. Relatively smooth sedimentary layers are observed below the lower slope of the continent whereas several mud diapers are imaged below the upper slope of the continent. Above the mud diapers, we find gas hydrates with high velocity of about 1.9-2.1 km/s and thickness of about 100 m immediately above the strong BSR. Similarly, near the mud diapers, free gas with low velocity of about 1.4-1.7 km/s and thickness of about 200 m is imaged. Migration of free gas through diapirism may result in lots of gas hydrates accumulated below the upper slope of the continent offshore SW Taiwan.

Escape fraction of ionizing photons during reionization: Effects due to supernova feedback and runaway ob stars

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

Kimm, Taysun; Cen, Renyue

2014-06-20

The fraction of hydrogen ionizing photons escaping from galaxies into the intergalactic medium is a critical ingredient in the theory of reionization. We use two zoomed-in, high-resolution (4 pc), cosmological radiation hydrodynamic simulations with adaptive mesh refinement to investigate the impact of two physical mechanisms (supernova, SN, feedback, and runaway OB stars) on the escape fraction (f {sub esc}) at the epoch of reionization (z ≥ 7). We implement a new, physically motivated SN feedback model that can approximate the Sedov solutions at all (from the free expansion to snowplow) stages. We find that there is a significant time delaymore » of about ten million years between the peak of star formation and that of escape fraction, due to the time required for the build-up and subsequent destruction of the star-forming cloud by SN feedback. Consequently, the photon number-weighted mean escape fraction for dwarf galaxies in halos of mass 10{sup 8}-10{sup 10.5} M {sub ☉} is found to be 〈f{sub esc}〉∼11%, although instantaneous values of f {sub esc} > 20% are common when star formation is strongly modulated by the SN explosions. We find that the inclusion of runaway OB stars increases the mean escape fraction by 22% to 〈f{sub esc}〉∼14%. As SNe resulting from runaway OB stars tend to occur in less dense environments, the feedback effect is enhanced and star formation is further suppressed in halos with M{sub vir}≳10{sup 9} M{sub ⊙} in the simulation with runaway OB stars compared with the model without them. While both our models produce enough ionizing photons to maintain a fully ionized universe at z ≤ 7 as observed, a still higher amount of ionizing photons at z ≥ 9 appears necessary to accommodate the high observed electron optical depth inferred from cosmic microwave background observations.« less

Neogene amphibians and reptiles (Caudata, Anura, Gekkota, Lacertilia, and Testudines) from the south of Western Siberia, Russia, and Northeastern Kazakhstan

PubMed Central

Zazhigin, Vladimir S.

2017-01-01

Background The present-day amphibian and reptile fauna of Western Siberia are the least diverse of the Palaearctic Realm, as a consequence of the unfavourable climatic conditions that predominate in this region. The origin and emergence of these herpetofaunal groups are poorly understood. Aside from the better-explored European Neogene localities yielding amphibian and reptile fossil remains, the Neogene herpetofauna of Western Asia is understudied. The few available data need critical reviews and new interpretations, taking into account the more recent records of the European herpetofauna. The comparison of this previous data with that of European fossil records would provide data on palaeobiogeographic affiliations of the region as well as on the origin and emergence of the present-day fauna of Western Siberia. An overview of the earliest occurrences of certain amphibian lineages is still needed. In addition, studies that address such knowledge gaps can be useful for molecular biologists in their calibration of molecular clocks. Methods and Results In this study, we considered critically reviewed available data from amphibian and reptile fauna from over 40 Western Siberian, Russian and Northeastern Kazakhstan localities, ranging from the Middle Miocene to Early Pleistocene. Herein, we provided new interpretations that arose from our assessment of the previously published and new data. More than 50 amphibians and reptile taxa were identified belonging to families Hynobiidae, Cryptobranchidae, Salamandridae, Palaeobatrachidae, Bombinatoridae, Pelobatidae, Hylidae, Bufonidae, Ranidae, Gekkonidae, Lacertidae, and Emydidae. Palaeobiogeographic analyses were performed for these groups and palaeoprecipitation values were estimated for 12 localities, using the bioclimatic analysis of herpetofaunal assemblages. Conclusion The Neogene assemblage of Western Siberia was found to be dominated by groups of European affinities, such as Palaeobatrachidae, Bombina, Hyla, Bufo

Characterization of recombinant PPi-dependent 6-phosphofructokinases from Methylosinus trichosporium OB3b and Methylobacterium nodulans ORS 2060.

PubMed

Rozova, O N; Khmelenina, V N; Trotsenko, Y A

2012-03-01

The properties of the purified recombinant PPi-dependent 6-phosphofructokinases (PPi-PFKs) from the methanotroph Methylosinus trichosporium OB3b and rhizospheric phytosymbiont Methylobacterium nodulans ORS 2060 were determined. The dependence of activities of PPi-PFK-His(6)-tag from Ms. trichosporium OB3b (6 × 45 kDa) and PPi-PFK from Mb. nodulans ORS 2060 (4 × 43 kDa) on the concentrations of substrates of forward and reverse reactions conformed to Michaelis-Menten kinetics. Besides fructose-6-phosphate, the enzymes also phosphorylated sedoheptulose-7-phosphate. ADP or AMP (1 mM each) inhibited activity of the Ms. trichosporium PPi-PFK but did not affect the activity of the Mb. nodulans enzyme. Preference of PPi-PFKs to fructose-1,6-bisphosphate implied a predominant function of the enzymes in hexose phosphate synthesis in these bacteria. PPi-PFKs from the methylotrophs have low similarity of translated amino acid sequences (17% identity) and belong to different phylogenetic subgroups of type II 6-phosphofructokinases. The relationship of PPi-PFKs with microaerophilic character of Ms. trichosporium OB3b and adaptation of Mb. nodulans ORS 2060 to anaerobic phase of phytosymbiosis are discussed.

The spatiotemporal distribution of dissolved carbon in the main stems and their tributaries along the lower reaches of Heilongjiang River Basin, Northeast China.

PubMed

Wang, Lili; Song, Changchun; Guo, Yuedong

2016-01-01

The Heilongjiang River Basin in the eastern Siberia, one of the largest river basins draining to the North Pacific Ocean, is a border river between China, Mongolia, and Russia. In this study, we examined the spatial and seasonal variability in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and dissolved total carbon (DTC) concentrations along lower reaches of Heilongjiang River Basin, China. Water samples were collected monthly along the mouths of main rivers (Heilongjiang River, Wusuli River, and Songhua River) and their ten tributary waters for 2 years. The DOC concentrations of waters ranged from 1.74 to 16.64 mg/L, with a mean value of 8.90 ± 0.27 mg/L (n = 165). Notably, mean DIC concentrations were 9.08 ± 0.31 mg/L, accounting for 13.26∼83.27% of DTC. DIC concentrations increased significantly after the Heilongjiang River passed through Northeast China, while DOC concentrations decreased. Over 50% of DIC concentrations were decreased during exports from groundwater to rice fields and from rice fields to ditches. Water dissolved carbon showed large spatial and temporal variations during the 2-year measurement, suggesting that more frequently samplings were required. Carbon (DIC + DOC) loads from the Heilongjiang River to the Sea of Okhotsk were estimated to be 3.26 Tg C/year in this study, accounting for 0.64% of the global water dissolved carbon flux. DIC export contributed an average of 51.84% of the estimated carbon load in the Heilongjiang River, acting as an important carbon component during riverine transport. Our study could provide some guides on agricultural water management and contribute to more accurately estimate global carbon budgets.

ObsPy: A Python toolbox for seismology - Current state, applications, and ecosystem around it

NASA Astrophysics Data System (ADS)

Lecocq, Thomas; Megies, Tobias; Krischer, Lion; Sales de Andrade, Elliott; Barsch, Robert; Beyreuther, Moritz

2016-04-01

ObsPy (http://www.obspy.org) is a community-driven, open-source project offering a bridge for seismology into the scientific Python ecosystem. It provides * read and write support for essentially all commonly used waveform, station, and event metadata formats with a unified interface, * a comprehensive signal processing toolbox tuned to the needs of seismologists, * integrated access to all large data centers, web services and databases, and * convenient wrappers to third party codes like libmseed and evalresp. Python, in contrast to many other languages and tools, is simple enough to enable an exploratory and interactive coding style desired by many scientists. At the same time it is a full-fledged programming language usable by software engineers to build complex and large programs. This combination makes it very suitable for use in seismology where research code often has to be translated to stable and production ready environments. It furthermore offers many freely available high quality scientific modules covering most needs in developing scientific software. ObsPy has been in constant development for more than 5 years and nowadays enjoys a large rate of adoption in the community with thousands of users. Successful applications include time-dependent and rotational seismology, big data processing, event relocations, and synthetic studies about attenuation kernels and full-waveform inversions to name a few examples. Additionally it sparked the development of several more specialized packages slowly building a modern seismological ecosystem around it. This contribution will give a short introduction and overview of ObsPy and highlight a number of use cases and software built around it. We will furthermore discuss the issue of sustainability of scientific software.

ObsPy: A Python toolbox for seismology - Current state, applications, and ecosystem around it

NASA Astrophysics Data System (ADS)

Krischer, L.; Megies, T.; Sales de Andrade, E.; Barsch, R.; Beyreuther, M.

2015-12-01

ObsPy (http://www.obspy.org) is a community-driven, open-source project offering a bridge for seismology into the scientific Python ecosystem. It provides read and write support for essentially all commonly used waveform, station, and event metadata formats with a unified interface, a comprehensive signal processing toolbox tuned to the needs of seismologists, integrated access to all large data centers, web services and databases, and convenient wrappers to third party codes like libmseed and evalresp. Python, in contrast to many other languages and tools, is simple enough to enable an exploratory and interactive coding style desired by many scientists. At the same time it is a full-fledged programming language usable by software engineers to build complex and large programs. This combination makes it very suitable for use in seismology where research code often has to be translated to stable and production ready environments. It furthermore offers many freely available high quality scientific modules covering most needs in developing scientific software.ObsPy has been in constant development for more than 5 years and nowadays enjoys a large rate of adoption in the community with thousands of users. Successful applications include time-dependent and rotational seismology, big data processing, event relocations, and synthetic studies about attenuation kernels and full-waveform inversions to name a few examples. Additionally it sparked the development of several more specialized packages slowly building a modern seismological ecosystem around it.This contribution will give a short introduction and overview of ObsPy and highlight a number of us cases and software built around it. We will furthermore discuss the issue of sustainability of scientific software.

Database of in-situ field measurements for estimates of fuel consumption and fire emissions in Siberia

NASA Astrophysics Data System (ADS)

Kukavskaya, Elena; Conard, Susan; Buryak, Ludmila; Ivanova, Galina; Soja, Amber; Kalenskaya, Olga; Zhila, Sergey; Zarubin, Denis; Groisman, Pavel

2016-04-01

Wildfires show great variability in the amount of fuel consumed and carbon emitted to the atmosphere. Various types of models are used to calculate global or large scale regional fire emissions. However, in the databases used to estimate fuel consumptions, data for Russia are typically under-represented. Meanwhile, the differences in vegetation and fire regimes in the boreal forests in North America and Eurasia argue strongly for the need of regional ecosystem-specific data. For about 15 years we have been collecting field data on fuel loads and consumption in different ecosystem types of Siberia. We conducted a series of experimental burnings of varying fireline intensity in Scots pine and larch forests of central Siberia to obtain quantitative and qualitative data on fire behavior and carbon emissions. In addition, we examined wildfire behavior and effects in different vegetation types including Scots pine, Siberian pine, fir, birch, poplar, and larch-dominated forests; evergreen coniferous shrubs; grasslands, and peats. We investigated various ecosystem zones of Siberia (central and southern taiga, forest-steppe, steppe, mountains) in the different subjects of the Russian Federation (Krasnoyarsk Kray, Republic of Khakassia, Republic of Buryatia, Tuva Republic, Zabaikalsky Kray). To evaluate the impact of forest practices on fire emissions, burned and unburned logged sites and forest plantations were examined. We found large variations of fuel consumption and fire emission rates among different vegetation types depending on growing conditions, fire behavior characteristics and anthropogenic factors. Changes in the climate system result in an increase in fire frequency, area burned, the number of extreme fires, fire season length, fire season severity, and the number of ignitions from lightning. This leads to an increase of fire-related emissions of carbon to the atmosphere. The field measurement database we compiled is required for improving accuracy of existing

Multiwavelength Studies of Young OB Associations

NASA Astrophysics Data System (ADS)

Feigelson, Eric D.

We discuss how contemporary multiwavelength observations of young OB-dominated clusters address long-standing astrophysical questions: Do clusters form rapidly or slowly with an age spread? When do clusters expand and disperse to constitute the field star population? Do rich clusters form by amalgamation of smaller subclusters? What is the pattern and duration of cluster formation in massive star forming regions (MSFRs)? Past observational difficulties in obtaining good stellar censuses of MSFRs have been alleviated in recent studies that combine X-ray and infrared surveys to obtain rich, though still incomplete, censuses of young stars in MSFRs. We describe here one of these efforts, the MYStIX project, that produced a catalog of 31,784 probable members of 20 MSFRs. We find that age spread within clusters is real in the sense that the stars in the core formed after the cluster halo. This is consistent with some recent astrophysical models involving merging star-forming filaments. Cluster expansion is seen in the ensemble of (sub)clusters, and older dispersing populations are found across MSFRs. Long-lived, asynchronous star formation is pervasive across MSFRs.

Increased total DNA damage and oxidative stress in brain are associated with decreased longevity in high sucrose diet fed WNIN/Gr-Ob obese rats.

PubMed

Potukuchi, Aruna; Addepally, Uma; Sindhu, Kirankumar; Manchala, Raghunath

2017-06-01

Obesity and Type 2 Diabetes (T2D) are chronic nutrient-related disorders that occur together and pose a grave burden to society. They are among the most common causes of ageing and death. Obesity and T2D per se accelerate ageing albeit the underlying mechanisms are unclear yet. Also, it is not clear whether or not superimposing T2D on obesity accelerates ageing. Present study validated the hypothesis, 'super-imposing T2D on obesity accelerates ageing' in WNIN/Gr-Ob, the impaired glucose tolerant, obese rat as the model and evaluated probable underlying mechanisms. To estimate the survival analysis of WNIN/Gr-Ob rats induced with T2D. To determine the extent of DNA damage and oxidative stress in the brain, the master controller of the body, in WNIN/Gr-Ob rats with/without high sucrose induced T2D/aggravation of insulin resistance (IR) after 3 and 6 months of feeding. T2D was induced/IR was aggravated by feeding high sucrose diet (HSD) to 9-10 weeks old, male WNIN/Gr-Ob rats. Survival percentage was determined statistically by Kaplan-Meier estimator. Neuronal DNA damage was quantified by the Comet assay while the oxidative stress and antioxidant status were evaluated from the levels of malonaldialdehyde, reduced glutathione, and superoxide dismutase (SOD) activity. HSD feeding decreased longevity of WNIN/Gr-Ob rats and was associated with significantly higher total neuronal DNA damage after three months of feeding but not later. In line with this was the increased neuronal oxidative stress (lipid peroxidation) and decreased antioxidant status (reduced glutathione and SOD activity) in HSD than Starch-based diet (SBD) fed rats. The results suggest that HSD feeding decreased the longevity of WNIN/Gr-Ob obese rats probably by increasing oxidative stress and aggravating IR, a condition that precedes T2D.

Lithospheric structure beneath the extinct ridge of South China Sea: Constraints from Rayleigh wave phase velocity tomography using OBS data

NASA Astrophysics Data System (ADS)

Yang, T.; Le, B. M.; passive-Source Seismic Team, S.

2016-12-01

What would happen when a mid-ocean-ridge stops spreading? Global occurrences of such ridges appear to indicate that magmatic activities had continued for million years after ridges were abandoned and often formed seamount chains over ridges. The extinct ridge and the seamount chain at the South China Sea represent one classic example of such ridges. To understand this unique process and the lithospheric and deep mantle structure, we carry out a Rayleigh wave phase velocity tomography using data from a passive-source OBS array experiment in South China Sea from 2012 to 2013. We correct OBS clock errors by using Scholte waves retrieved through cross-correlating hydrophone records of each OBS pair. 60 regional and teleseismic events with high quality Rayleigh waves are selected and their dispersion curves at the OBS array are used to inverse the phase velocities of periods from 15 s to 100 s. The shear wave velocity model derived from phase velocities of all periods shows a strong low-velocity zone situated beneath the seamounts starting at about 30 km depth. The lithosphere thickness of the extinct ridge inferred from this model provide insights on the cooling process and magmatism at this unique oceanic setting. In addition, our model images the tear of the subducting South China Sea plate beneath the Manila trench and Luzon island, which is clearly generated by the subduction of the extinct ridge and overriding seamounts.

Influence of logging on the effects of wildfire in Siberia

NASA Astrophysics Data System (ADS)

Kukavskaya, E. A.; Buryak, L. V.; Ivanova, G. A.; Conard, S. G.; Kalenskaya, O. P.; Zhila, S. V.; McRae, D. J.

2013-12-01

The Russian boreal zone supports a huge terrestrial carbon pool. Moreover, it is a tremendous reservoir of wood products concentrated mainly in Siberia. The main natural disturbance in these forests is wildfire, which modifies the carbon budget and has potentially important climate feedbacks. In addition, both legal and illegal logging increase landscape complexity and affect burning conditions and fuel consumption. We investigated 100 individual sites with different histories of logging and fire on a total of 23 study areas in three different regions of Siberia to evaluate the impacts of fire and logging on fuel loads, carbon emissions, and tree regeneration in pine and larch forests. We found large variations of fire and logging effects among regions depending on growing conditions and type of logging activity. Logged areas in the Angara region had the highest surface and ground fuel loads (up to 135 t ha-1), mainly due to logging debris. This resulted in high carbon emissions where fires occurred on logged sites (up to 41 tC ha-1). The Shushenskoe/Minusinsk and Zabaikal regions are characterized by better slash removal and a smaller amount of carbon emitted to the atmosphere during fires. Illegal logging, which is widespread in the Zabaikal region, resulted in an increase in fire hazard and higher carbon emissions than legal logging. The highest fuel loads (on average 108 t ha-1) and carbon emissions (18-28 tC ha-1) in the Zabaikal region are on repeatedly burned unlogged sites where trees fell on the ground following the first fire event. Partial logging in the Shushenskoe/Minusinsk region has insufficient impact on stand density, tree mortality, and other forest conditions to substantially increase fire hazard or affect carbon stocks. Repeated fires on logged sites resulted in insufficient tree regeneration and transformation of forest to grasslands. We conclude that negative impacts of fire and logging on air quality, the carbon cycle, and ecosystem

The Impact of Increasing Fire Frequency on Forest Transformations in the Zabaikal Region, Southern Siberia

NASA Astrophysics Data System (ADS)

Conard, S. G.; Kukavskaya, E. A.; Buryak, L. V.; Shvetsov, E.; Kalenskaya, O. P.; Zhila, S.

2017-12-01

The Zabaikal region of southern Siberia is characterized by some of the highest fire activity in Russia. There has been a significant increase of fire frequency and burned area in the region over the last two decades due to a combination of high anthropogenic pressure, decreased funding to the forestry sector, and increased fire danger, which was associated with higher frequency and intensity of extreme weather events. Central and southern parts of the Zabaikal region where population density is higher and road network is relatively more developed are the most disturbed by fires. Larch stands cover the largest proportion of fire-disturbed lands in the region, while the less common pine and birch stands are characterized by higher fire frequency. About 13% (3.9 M ha) of the total forest area in the Zabaikal region was burned more than once in the 20 years from 1996 to 2015, with many sites burned multiple times. Repeat disturbances led to inadequate tree regeneration on all but the moistest sites. Pine stands on dry soils, which are common in the forest-steppe zone, were the most vulnerable. After repeat burns and over large burned sites we observed transformation of the forests to steppe ecosystems. The most likely causes of insufficient forest regeneration are soil overheating, dominance of tall grasses, and lack of nearby seed sources. Extensive tree plantations have potential to mitigate negative fire impacts; however, due to high fire hazard in the recent decade about half of the plantation area has been burned. Changes in the SWVI index were used to assess postfire reforestation based on a combination of satellite and field data. In the southwestern part of the Zabaikal region, we estimated that reforestation had been hampered over 11% of the forest land area. Regional climate models project increasing temperatures and decreasing precipitation across Siberia by the end of the 21st century, with changes in the Zabaikal region projected to be more than twice the

Highly pathogenic influenza H5N1 virus of clade 2.3.2.1c in Western Siberia.

PubMed

Marchenko, V Y; Susloparov, I M; Kolosova, N P; Goncharova, N I; Shipovalov, A V; Ilyicheva, T N; Durymanov, A G; Chernyshova, O A; Kozlovskiy, L I; Chernyshova, T V; Pryadkina, E N; Karimova, T V; Mikheev, V N; Ryzhikov, A B

2016-06-01

In the spring of 2015, avian influenza virus surveillance in Western Siberia resulted in isolation of several influenza H5N1 virus strains. The strains were isolated from several wild bird species. Investigation of biological features of those strains demonstrated their high pathogenicity for mammals. Phylogenetic analysis of the HA gene showed that the strains belong to clade 2.3.2.1c.

High-latitude regions of Siberia and Northeast Russia in the Paleogene: Stratigraphy, flora, climate, coal accumulation

NASA Astrophysics Data System (ADS)

Akhmetiev, M. A.

2015-07-01

The geological structure and development history of superposed depressions on the Arctic coast of East Siberia and Bering Sea region (Chukotka, Koryakiya, northern Kamchatka) in the Early Paleogene are considered with the analysis of their flora and climatic parameters. The paleofloral analysis revealed thermophilic assemblages that reflect phases of maximum warming at the Paleocene-Eocene transition and in the Early Eocene. The appearance of thermophilic plants (Magnoliaceae, Myrtaceae, Lauraceae, Araliaceae, Loranthaceae, and others) in the Siberian segment of the Arctic region is explained by the stable atmospheric heat transfer from the Tethys to higher latitudes and absence of the latitudinal orographic barrier (Alpine-Himalayan belt). The plants migrated to high latitudes also along the meridional seaway that connected the Tethys with the Arctic Ocean via marine basins of the Eastern Paratethys, Turgai Strait, and West Siberia. The migration from the American continent was realized along the southern coast of Beringia under influence of a warm current flowing from low latitudes along the western coast of North America. The palm genus Sabal migrated to northern Kamchatka and Koryakiya precisely in this way via southern Alaska. In the Oligocene, shallow-water marine sediments in high-latitude regions were replaced by terrestrial facies. The Late Oligocene was marked by maximum cooling. Coal accumulation in Northeast Russia through the Paleogene is reviewed.

Ca²⁺ signal contributing to the synthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia'.

PubMed

Hu, Zenghui; Li, Tianjiao; Zheng, Jian; Yang, Kai; He, Xiangfeng; Leng, Pingsheng

2015-06-01

The floral scent is an important part of plant volatile compounds, and is influenced by environmental factors. The emission of monoterpenes of Lilium 'siberia' is regulated by light intensity, but the mechanism is large unknown. In this study, the expression of Li-mTPS, a monoterpene synthase gene in the tepals of Lilium 'siberia', and net Ca(2+) flux were investigated after exposure to different levels of light intensity (0, 100, 300, 600, 1000, and 1500 μmol m(-2) s(-1)). Moreover the effect of LaCl3 and ethylene glycol-bis-(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) on the Li-mTPS expression, monoterpene emission, and net Ca(2+) flux were examined at 600 μmol m(-2) s(-1). The results showed that along with the enhancement of light intensity, the expression level of Li-mTPS increased gradually, and the net Ca(2+) influx was also enhanced showing a similar pattern. It was found that LaCl3 and EGTA effectively inhibited the increase in expression of Li-mTPS and the net Ca(2+) influx induced by light treatment. Moreover, the release amounts of monoterpenes decreased significantly after treatment with LaCl3 and EGTA. So it can be concluded that Ca(2+) signal contributed to the biosynthesis and emission of monoterpenes regulated by light intensity in Lilium 'siberia' tepals. The increased light intensity firstly triggered the Ca(2+) influx to cytoplasm, and then the gene expression of monoterpene synthases downstream was activated to regulate the biosynthesis and emission of monoterpenes. But in the signaling pathway other mechanisms were thought to be involved in the emission of monoterpenes regulated by light intensity, which need to be investigated in future research. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

An arctic fox rabies virus strain as the cause of human rabies in Russian Siberia.

PubMed

Kuzmin, I V

1999-01-01

A case of human rabies in the arctic zone of Siberia is described. The victim was bitten by a wolf, but characterization of the isolate by monoclonal antibodies showed that it was an arctic fox virus strain. This discovery reaffirmed the value of strain typing rabies virus isolates in regions where this has not been done already: such characterization pertains to the identification of the reservoir host, to the natural history of the virus in the reservoir, and to future surveillance, post-exposure treatment, and public education in the region.

The Yudomian of Siberia, Vendian and Ediacaran systems of the International stratigraphic scale

NASA Astrophysics Data System (ADS)

Khomentovsky, V. V.

2008-12-01

In Russia, the terminal Neoproterozoic formally includes the Vendian of western part of the East European platform and the concurrent Yudoma Group of Siberia. As is shown in this work, the designated subdivisions correspond in the stratotypes only to the upper, Yudomian Series of the Vendian. In the Siberian platform, the Ust-Yudoma and Aim horizons of the Yudomian are tightly interrelated. The lower of them, bearing remains of Ediacaran Fauna, represents the Ediacarian Stage, whereas the upper one containing small-shelled fossils (SSF) corresponds to the Nemakit-Daldynian Stage divided into the trisulcatus and antiqua superregional zones. In more complete sections of the platform periphery, sediments of these subdivisions conformably rest on siliciclastic succession that should be ranked as basal subdivision of the Yudomian. The succession is concurrent to the Laplandian Stage of the East European platform. According to geochronological dates obtained recently, the Yudomian Series spans interval of 600-540 Ma. In the East European platform, the Upper Vendian (Yudomian) begins with the Laplandian basal tillites of synonymous stage. In the west of the platform, tillites are dated at 600 Ma like the Upper Vendian base in Siberia. The next Ediacarian Stage of the East European platform is stratigraphic equivalent of the Redkino Horizon, while summary range of the Kotlin and Rovno horizons is concurrent to that of the Nemakit-Daldynian Stage. The Vendian of Russia is conformably overlain by the Tommotian Stage of the Lower Cambrian. Intense pre-Vendian events constrained distribution areas of the Lower Vendian sediments in Russia. The Lower Vendian deposits of the East European platform are most representative and well studied in the central Urals, where they are attributed to the Serebryanka Group. In Siberia, separate subdivisions representing the Lower Vendian are the Maastakh Formation of the Olenek Uplift, two lower members of the Ushakovka Formation in the Baikal

Relict gas hydrates as possible reason of gas emission from shallow permafrost at the northern part of West Siberia

NASA Astrophysics Data System (ADS)

Chuvilin, Evgeny; Bukhanov, Boris; Tumskoy, Vladimir; Istomin, Vladimir; Tipenko, Gennady

2017-04-01

Intra-permafrost gas (mostly methane) is represent a serious geological hazards during exploration and development of oil and gas fields. Special danger is posed by large methane accumulations which usually confined to sandy and silty sand horizons and overlying in the frozen strata on the depth up to 200 meters. Such methane accumulations are widely spread in a number of gas fields in the northern part of Western Siberia. According to indirect indicators this accumulations can be relic gas hydrates, that formed earlier during favorable conditions for hydrate accumulation (1, 2). Until now, they could be preserved in the frozen sediments due to geological manifestation of the self-preservation effect of gas hydrates at temperatures below zero. These gas hydrate formations, which are lying above the gas hydrate stability zone today, are in a metastable state and are very sensitive to various anthropogenic impacts. During drilling and operation of production wells in the areas where the relic of gas hydrates can occur, there are active gas emission and gas explosion, that can lead to various technical complications up to the accident. Mathematical and experimental simulations were were conducted to evaluate the possibility of existence of relic gas hydrates in the northern part of West Siberia. The results of math simulations revealed stages of geological history when the gas hydrate stability zone began virtually from the ground surface and saturated in shallow permafrost horizons. Later permafrost is not completely thaw. Experimental simulations of porous gas hydrate dissociation in frozen soils and evaluation of self-preservation manifestation of gas hydrates at negative temperatures were carried out for identification conditions for relic gas hydrates existence in permafrost of northern part of West Siberia. Sandy and silty sand sediments were used in experimental investigations. These sediments are typical of most gas-seeping (above the gas hydrate stability

A Multi-Fiber Spectroscopic Search for Low-mass Young Stars in Orion OB1

NASA Astrophysics Data System (ADS)

Loerincs, Jacqueline; Briceno, Cesar; Calvet, Nuria; Mateo, Mario L.; Hernandez, Jesus

2017-01-01

We present here results of a low resolution spectroscopic followup of candidate low-mass pre-main sequence stars in the Orion OB1 association. Our targets were selected from the CIDA Variability Survey of Orion (CVSO), and we used the Michigan/Magellan Fiber Spectrograph (M2FS) on the Magellan Clay 6.5m telescope to obtain spectra of 500 candidate T Tauri stars distributed in seven 0.5 deg diameter fields, adding to a total area of ~5.5 deg2. We identify young stars by looking at the distinctive Hα 6563 Å emission and Lithium Li I 6707 Å absorption features characteristic of young low mass pre-main sequence stars. Furthermore, by measuring the strength of their Hα emission lines, confirmed T Tauri stars can be classified as either Classical T Tauris (CTTS) or Weak-line T Tauris (WTTS), which give indication of whether the star is actively accreting material from a gas and dust disk surrounding the star, which may be the precursor of a planetary system. We confirm a total of 90 T Tauri stars, of which 50% are newly identified young members of Orion; out of the 49 new detections,15 are accreting CTTS, and of these all but one are found in the OB1b sub-region. This result is in line with our previous findings that this region is much younger than the more extended Orion OB1a sub-association. The M2FS results add to our growing census of young stars in Orion, that is allowing us to characterize in a systematic and consistent way the distribution of stellar ages across the entire complex, in order to building a complete picture of star formation in this, one of nearest most active sites of star birth.

Forest Aboveground Biomass Estimation in the Greater Mekong, Subregion and Russian Siberia

NASA Astrophysics Data System (ADS)

Pang, Yong; Li, Zengyuan; Sun, Gouqing; Zhang, Zhiyu; Schmullius, Christiane; Meng, Shili; Ma, Zhenyu; Lu, Hao; Li, Shiming; Liu, Qingwang; Bai, Lina; Tian, Xin

2016-08-01

Forests play a vital role in sustainable development and provide a range of economic, social and environmental benefits, including essential ecosystem services such as climate change mitigation and adaptation. We summarized works in forest aboveground biomass estimation in Greater Mekong Subregion (GMS) and Russian Siberia (RuS). Both regions are rich in forest resources. These mapping and estimation works were based on multiple-source remote sensing data and some field measurements. Biomass maps were generated at 500 m and 30 m pixel size for RuS and GMS respectively. With the available of the 2015 PALSAR-2 mosaic at 25 m spacing, Sentinel-2 data at 20 m, we will work on the biomass mapping and dynamic study at higher spatial resolution.

An anomalous extinction law in the Cep OB3b young cluster: Evidence for dust processing during gas dispersal

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

Allen, Thomas S.; Prchlik, Jakub J.; Megeath, S. Thomas

We determine the extinction law through Cep OB3b, a young cluster of 3000 stars undergoing gas dispersal. The extinction is measured toward 76 background K giants identified with MMT/Hectospec spectra. Color excess ratios were determined toward each of the giants using V and R photometry from the literature, g, r, i, and z photometry from the Sloan Digital Sky Survey and J, H, and K{sub s} photometry from the Two Micron All Sky Survey. These color excess ratios were then used to construct the extinction law through the dusty material associated with Cep OB3b. The extinction law through Cep OB3bmore » is intermediate between the R{sub V} = 3.1 and R{sub V} = 5 laws commonly used for the diffuse atomic interstellar medium and dense molecular clouds, respectively. The dependence of the extinction law on line-of-sight A{sub V} is investigated and we find the extinction law becomes shallower for regions with A{sub V} > 2.5 mag. We speculate that the intermediate dust law results from dust processing during the dispersal of the molecular cloud by the cluster.« less

WNIN/GR-Ob - an insulin-resistant obese rat model from inbred WNIN strain.

PubMed

Harishankar, N; Vajreswari, A; Giridharan, N V

2011-09-01

WNIN/GR-Ob is a mutant obese rat strain with impaired glucose tolerance (IGT) developed at the National Institute of Nutrition (NIN), Hyderabad, India, from the existing 80 year old Wistar rat (WNIN) stock colony. The data presented here pertain to its obese nature along with IGT trait as evidenced by physical, physiological and biochemical parameters. The study also explains its existence, in three phenotypes: homozygous lean (+/+), heterozygous carrier (+/-) and homozygous obese (-/-). Thirty animals (15 males and 15 females) from each phenotype (+/+, +/-, -/-) and 24 lean and obese (6 males and 6 females) rats were taken for growth and food intake studies respectively. Twelve adult rats from each phenotype were taken for body composition measurement by total body electrical conductivity (TOBEC); 12 rats of both genders from each phenotype at different ages were taken for clinical chemistry parameters. Physiological indices of insulin resistance were calculated according to the homeostasis model assessment for insulin resistance (HOMA-IR) and also by studying U¹⁴C 2-deoxy glucose uptake (2DG). WNINGR-Ob mutants had high growth, hyperphagia, polydipsia, polyurea, glycosuria, and significantly lower lean body mass, higher fat mass as compared with carrier and lean rats. These mutants, at 50 days of age displayed abnormal response to glucose load (IGT), hyperinsulinaemia, hypertriglyceridaemia, hypercholesterolaemia and hyperleptinaemia. Basal and insulin-stimulated glucose uptakes by diaphragm were significantly decreased in obese rats as compared with lean rats. Obese rats of the designated WNIN/GR-Ob strain showed obesity with IGT, as adjudged by physical, physiological and biochemical indices. These indices varied among the three phenotypes, being lowest in lean, highest in obese and intermediate in carrier phenotypes thereby suggesting that obesity is inherited as autosomal incomplete dominant trait in this strain. This mutant obese rat model is easy to

High S/N Echelle spectroscopy in young stellar groups. II. Rotational velocities of early-type stars in SCO OB2.

NASA Astrophysics Data System (ADS)

Brown, A. G. A.; Verschueren, W.

1997-03-01

We investigate the rotational velocities of early-type stars in the Sco OB2 association. We measure v.sin(i) for 156 established and probable members of the association. The measurements are performed with three different techniques, which are in increasing order of expected v.sin(i): 1) converting the widths of spectral lines directly to v.sin(i), 2) comparing artificially broadened spectra of low v.sin(i) stars to the target spectrum, 3) comparing the HeI λ4026 line profile to theoretical models. The sample is extended with literature data for 47 established members of Sco OB2. Analysis of the v.sin(i) distributions shows that there are no significant differences between the subgroups of Sco OB2. We find that members of the binary population of Sco OB2 on the whole rotate more slowly than the single stars. In addition, we find that the B7-B9 single star members rotate significantly faster than their B0-B6 counterparts. We test various hypotheses for the distribution of v.sin(i) in the association. The results show that we cannot clearly exclude any form of random distribution of the direction and/or magnitude of the intrinsic rotational velocity vector. We also investigate the effects of rotation on colours in the Walraven photometric system. We show that positions of B7-B9 single dwarfs above the main sequence are a consequence of rotation. This establishes the influence of rotation on the Walraven colours, due primarily to surface gravity effects.

Influence of topographic heterogeneity on the abandance of larch forest in eastern Siberia

NASA Astrophysics Data System (ADS)

Sato, H.; Kobayashi, H.

2016-12-01

In eastern Siberia, larches (Larix spp.) often exist in pure stands, constructing the world's largest coniferous forest, of which changes can significantly affect the earth's albedo and the global carbon balance. We have conducted simulation studies for this vegetation, aiming to forecast its structures and functions under changing climate (1, 2). In previous studies of simulating vegetation at large geographical scales, the examining area is divided into coarse grid cells such as 0.5 * 0.5 degree resolution, and topographical heterogeneities within each grid cell are just ignored. However, in Siberian larch area, which is located on the environmental edge of existence of forest ecosystem, abundance of larch trees largely depends on topographic condition at the scale of tens to hundreds meters. We, therefore, analyzed patterns of within-grid-scale heterogeneity of larch LAI as a function of topographic condition, and examined its underlying reason. For this analysis, larch LAI was estimated for each 1/112 degree from the SPOT-VEGETATION data, and topographic properties such as angularity and aspect direction were estimated form the ASTER-GDEM data. Through this analysis, we found that, for example, sign of correlation between angularity and larch LAI depends on hydrological condition on the grid cell. We then refined the hydrological sub-model of our vegetation model SEIB-DGVM, and validated whether the modified model can reconstruct these patterns, and examined its impact on the estimation of biomass and vegetation productivity of entire larch region. -- References --1. Sato, H., et al. (2010). "Simulation study of the vegetation structure and function in eastern Siberian larch forests using the individual-based vegetation model SEIB-DGVM." Forest Ecology and Management 259(3): 301-311.2. Sato, H., et al. (2016). "Endurance of larch forest ecosystems in eastern Siberia under warming trends." Ecology and Evolution

Radiative Characteristics of Aerosol During Extreme Fire Event over Siberia in Summer 2012

NASA Technical Reports Server (NTRS)

Zhuravleva, Tatiana B.; Kabanov, Dmitriy M.; Nasrtdinov, Ilmir M.; Russkova, Tatiana V.; Sakerin, Sergey M.; Smirnov, Alexander; Holben, Brent N.

2017-01-01

Microphysical and optical properties of aerosol were studied during a mega-fire event in summer 2012 over Siberia using ground-based measurements of spectral solarradiation at the AERONET site in Tomsk and satellite observations. The data were analyzed using multi-year (2003-2013) measurements of aerosol characteristics under back-ground conditions and for less intense fires, differing in burning biomass type, stage of fire, remoteness from observation site, etc. (ordinary smoke). In June-August 2012, the average aerosol optical depth (AOD, 500 nm) had been 0.95+/-0.86, about a factor of 6 larger than background values (0.16+/-0.08), and a factor of 2.5 larger than in ordinary smoke. The AOD values were extremely high on 24-28 July and reached 3-5. A comparison with satellite observations showed that ground-based measurements in the region of Tomsk not only reflect the local AOD features, but are also characteristic for the territory of Western Siberia as a whole. Single scattering albedo (SSA, 440 nm) in this period ranged from 0.91 to 0.99 with an average of approx. 0.96 in the entire wavelength range of 440-1020 nm. The increase in absorptance of aerosol particles (SSA(440 nm)=0.92) and decrease in SSA with wavelength observed in ordinary smoke agree with the data from multi-year observations in analogous situations in the boreal zone of USA and Canada. Volume aerosol size distribution in extreme and ordinary smoke had a bimodal character with significant prevalence of fine-mode particles, but in summer 2012 the mean median radius and the width of the fine-mode distribution somewhat increased. In contrast to data from multi-year observations, in summer 2012 an increase in the volume concentration and median radius of the coarse mode was observed with growing AOD.

Linking trace gas measurements and molecular tracers of organic matter in aerosols for identification of ecosystem sources and types of wildfires in Central Siberia

NASA Astrophysics Data System (ADS)

Panov, A. V.; Prokushkin, A. S.; Korets, M. A.; Bryukhanov, A. V.; Myers-Pigg, A. N.; Louchouarn, P.; Sidenko, N. V.; Amon, R.; Andreae, M. O.; Heimann, M.

2016-11-01

Summer 2012 was one of the extreme wildfire years in Siberia. At the surface air monitoring station “ZOTTO” (60°48'N, 89°21'E, 114 m a.s.l.) in Central Siberia we observed biomass burning (BB) influence on the ongoing atmospheric measurements within more than 50 % of the time in June-July 2012 that indicates a 30 times greater wildfire signal compared to previously reported ordinary biomass burning signature for the study area. While previous studies thoroughly estimated a relative input of BB into aerosol composition (i.e. size distribution, physical and optical parameters etc.) at ZOTTO, in this paper we characterize the source apportionment of the smoke aerosols with molecular tracer techniques from large-scale wildfires occurred in 2012 in the two prevailing types of Central Siberian ecosystems: complexes of pine forests and bogs and dark coniferous forests. Wildfires in the selected ecosystems are highly differed by their combustion phase (flaming/smoldering), the type of fire (crown/ground), biomass fuel, and nature of soil that greatly determines the smoke particle composition. Anhydrosugars (levoglucosan and its isomers) and lignin phenols taken as indicators of the sources and the state of particulate matter (PM) inputs in the specific fire plumes were used as powerful tools to compare wildfires in different environmental conditions and follow the role and contribution of different sources of terrestrial organic matter in the transport of BB pollutants into the pristine atmosphere of boreal zone in Central Siberia.

A "Mesosiderite" Rock from Northern Siberia, Russia: Not a Meteorite

NASA Technical Reports Server (NTRS)

Treiman, Allan H.; Lindstrom, David J.; Schwandt, Craig S.; Franchi, Ian A.; Morgan, Matthew L.

2002-01-01

A possible mesosiderite meteorite was found in the area of the Putorana Plateau, Noril'sk district, Siberia, Russia. Although this rock resembles a mesosiderite in its hand-sample aspect and in having Ni-bearing iron metal, it is not a meteorite. This inference is based on the lack of a fusion crust, the lack of cosmogenic nuclides, oxygen with terrestrial isotope ratios, and several mineral chemical criteria. Most likely, the rock is from the iron-metal-bearing basalts of the Siberian Trap basalt sequence, which are mined for their base and platinum-group metals. Mesosiderite imposters like this may be recognized by: (1) the presence of Cu metal in hand sample or as microscopic blebs in the low-Ni metal (kamacite), (2) the absence of high-Ni metal (taenite), and (3) the presence of iron carbide (cohenite) enclosing the kamacite. Even if these macroscopic tests are inconclusive, isotopic and mineral chemical tests will also distinguish rocks like this from mesosiderites.

Fallout traces of the Fukushima NPP accident in southern West Siberia (Novosibirsk, Russia).

PubMed

Melgunov, M S; Pokhilenko, N P; Strakhovenko, V D; Sukhorukov, F V; Chuguevskii, A V

2012-05-01

The fallout of artificially produced radioactive isotopes has been recorded at a site in southern West Siberia (54°50'43.6″ N, 083°06'22.4″ E, Novosibirsk, Russia). The highest activities of (131)I, (134)Cs, and (136)Cs were found in fresh snow precipitated on 02 April 2011, at 0.83, 0.092, and 0.002 Bq L(-1) of meltwater, respectively. The (131)I/(134)Cs ratio decreased from 9.0 on 02 April to 1.2 on 27 April, which is consistent with the radioactive decay of (131)I. This fallout can only have originated from the accidental emission of Fukushima Nuclear Power Plant, Japan, in March 2011.

Birch Stands Growth Increase in Western Siberia

NASA Technical Reports Server (NTRS)

Kharuk, Viacheslav I.; Kuzmichev, Valeriy V.; Im, Sergey T.; Ranson, Kenneth J.

2014-01-01

Birch (Betula pendula Roth) growth within the Western Siberia forest-steppe was analyzed based on long-term (1897-2006) inventory data (height, diameter at breast height [dbh], and stand volume). Analysis of biometry parameters showed increased growth at the beginning of twenty-first century compared to similar stands (stands age = 40-60 years) at the end of nineteenth century. Mean height, dbh, and stem volume increased from 14 to 20 m, from 16 to 22 cm, and from approx. 63 to approx. 220 cu m/ha, respectively. Significant correlations were found between the stands mean height, dbh, and volume on the one hand, and vegetation period length (r(sub s) = 0.71 to 0.74), atmospheric CO2 concentration (r(sub s) = 0.71 to 0.76), and drought index (Standardized Precipitation-Evapotranspiration Index, r(sub s) = -0.33 to -0.51) on the other hand. The results obtained have revealed apparent climate-induced impacts (e.g. increase of vegetation period length and birch habitat drying due to drought increase) on the stands growth. Along with this, a high correlation of birch biometric parameters and [CO2] in ambient air indicated an effect of CO2 fertilization. Meanwhile, further drought increase may switch birch stand growth into decline and greater mortality as has already been observed within the Trans-Baikal forest-steppe ecotone.

Trends in trace organic and metal concentrations in the Pechora and Kara Seas and adjacent rivers

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

Brooks, J.M.; Champ, M.A.; Wade, T.L.

1995-12-31

Trace organic (pesticides, PCBs, PAHs and dioxin/furan) and trace metal concentrations have been measured in surficial sediment and tissue (i.e., clam, fish liver and flesh) samples from the Pechora and Kara Seas and their adjacent rivers -- Pechora, Ob and Yenisey Rivers. Total PAH, PCB and total DDT and chlordane concentrations ranged in surficial sediments from n.d. to 810 ppb, n.d.--8.7 ppb, n.d.--1.2 ppb, and n.d.--1.2 ppb, respectively, in a suite of 40 samples from the Kara Sea and its adjacent rivers. The highest concentrations of many of the trace organic and metal contaminants were found in the lower partmore » of the Yenisey River below the salt wedge. Some trace metals (As for example) were elevated in the Pechora River dispositional plume region. Dioxin ranged from 1.36 to 413 ppt in a subset of 20 sediment samples. Higher trace organic contaminant concentrations compared to sediments were found in tissue samples from the region, especially fish liver samples. Concentrations as high as 1,114 ppb total PAHs, 89 ppb chlordane, 1,011 ppb for total DDT and 663 ppb PCBs were found in some fish liver samples. Dioxin concentrations in tissue samples ranged from 11.7 to 61 ppt. Concentrations of many trace organic and metal contaminants in these Russian marginal seas are influenced by inputs from these large Arctic rivers. Many organic contaminant concentrations in sediments are low, however detecting these compounds in tissue show they are bioavailable.« less

Kinematic Clues to OB Field Star Origins: Radial Velocities, Runaways, and Binaries

NASA Astrophysics Data System (ADS)

Januszewski, Helen; Castro, Norberto; Oey, Sally; Becker, Juliette; Kratter, Kaitlin M.; Mateo, Mario; Simón-Díaz, Sergio; Bjorkman, Jon E.; Bjorkman, Karen; Sigut, Aaron; Smullen, Rachel; M2FS Team

2018-01-01

Field OB stars are a crucial probe of star formation in extreme conditions. Properties of massive stars formed in relative isolation can distinguish between competing star formation theories, while the statistics of runaway stars allow an indirect test of the densest conditions in clusters. To address these questions, we have obtained multi-epoch, spectroscopic observations for a spatially complete sample of 48 OB field stars in the SMC Wing with the IMACS and M2FS multi-object spectrographs at the Magellan Telescopes. The observations span 3-6 epochs per star, with sampling frequency ranging from one day to about one year. From these spectra, we have calculated the radial velocities (RVs) and, in particular, the systemic velocities for binaries. Thus, we present the intrinsic RV distribution largely uncontaminated by binary motions. We estimate the runaway frequency, corresponding to the high velocity stars in our sample, and we also constrain the binary frequency. The binary frequency and fitted orbital parameters also place important constraints on star formation theories, as these properties drive the process of runaway ejection in clusters, and we discuss these properties as derived from our sample. This unique kinematic analysis of a high mass field star population thus provides a new look at the processes governing formation and interaction of stars in environments at extreme densities, from isolation to dense clusters.

New Low-mass Accretors in the Scorpius-Centaurus OB Association

NASA Astrophysics Data System (ADS)

Murphy, Simon J.; Lawson, Warrick A.; Bento, Joao

2016-01-01

We describe the serendipitous discovery of two new lithium-rich M5 members of the Scorpius-Centaurus OB Association (Sco-Cen). Both stars exhibit large 12 and 22 μm excesses and strong, variable Hα emission which we attribute to accretion from circumstellar discs. Such stars are thought to be incredibly rare at the ~16 Myr median age of much of Sco-Cen. The serendipitous discovery of two accreting stars hosting large quantities of circumstellar material may be indicative of a sizeable age spread in Sco-Cen, or further evidence that disc dispersal and planet formation time-scales are longer around lower-mass stars.

Cap-shaped gastropods from Upper Jurassic and Lower Cretaceous deposits of northern East Siberia

NASA Astrophysics Data System (ADS)

Guzhov, A. V.; Zakharov, V. A.

2015-09-01

Cap-shaped gastropods are first identified in Upper Jurassic and Lower Cretaceous sections of northern East Siberia. They belong to three new genera of the subclass Pectinibranchia ( Boreioconus gen. nov., Nixepileolus gen. nov., and Taimyroconus gen. nov.), which are identified at the species level ( B. bojarkensis sp. nov., N. depressus sp. nov., T. zakharovi sp. nov.), and several species with the open nomenclature. The genus Taimyroconus attributed to the family Calyptraeidae is considered as an ancestral form of the genus Crepidula. The stratigraphic position of each taxon is determined for several sections. The facies confinement, habitat conditions, and ethology of defined genera are considered with the analysis of their geographic distribution.

Abundances and Kinematics of OB Stars in the Leading Arm of the Magellanic System

NASA Astrophysics Data System (ADS)

Zhang, L.; Moni Bidin, C.; Casetti-Dinescu, D. I.; Mendez, R. A.; Girard, T. M.; Korchagin, V. I.; Vieira, K.; van Altena, W. F.; Zhao, G.

2018-01-01

We determined seven element abundances (He, C, N, O, Mg, Si, and S) and kinematics for eight O-/B- type stars which is selected from 42 candidates (Casetti-Dinescu et al. 2014) of membership in the Leading Arm (LA) of the Magellanic System. The high resolution spectra were taken with the MIKE instrument on the Magellan 6.5m Clay telescope.

Composition of particulate organic matter sampled in the troposphere over Siberia

NASA Astrophysics Data System (ADS)

Belan, Boris D.; Voronetskaya, Natalya G.; Pevneva, Galina S.; Golovko, Anatoly K.; Kozlov, Alexander S.; Simonenkov, Denis V.; Tolmachev, Gennadii N.

2015-04-01

In this paper we present some results of the analysis of organic compounds contained in the particulate matter sampled in the Siberian air shed during monthly research flights in 2012-2013. Aerosol sampling was performed in the tropospheric layer from 500 to 7000 m over the Karakan pine forest located on the east bank of the Novosibirsk Reservoir (River Ob). The Optik TU-134 aircraft laboratory was used as a research platform for in-situ measurements of atmospheric trace gas species and aerosols, as well as a particulate matter collection on PTFE filters. Analysis of the particulate organic matter sampled in the Siberian air shed in 2012-2013 allowed us to draw the following conclusions: the total content of n-alkanes increases in the spring and decreases in the winter. the length of the n-alkane homologous series had no seasonal dependence. maximum in the molecular weight distribution of n-alkanes varies depending on the season; compounds with C17, C22 and C25 chains dominated in winter and spring 2012, whereas in summer - C17 ones; in 2013 compounds with C17 chains dominated in winter, C18-C20 - in spring, and C21 and C23 - in summer. Carbon preference index (CPI) value for a given chain length of the homologous series (on the average from C12 to C28) did not reflect the contribution of sources of n-alkanes in the atmosphere. This work was supported by Interdisciplinary integration projects of the Siberian Branch of the Russian Academy of Science No. 35, No. 70 and No. 131; the Branch of Geology, Geophysics and Mining Sciences of RAS (Program No. 5); State contracts of the Ministry of Education and Science of Russia No. 14.604.21.0100, (RFMTFIBBB210290) and No. 14.613.21.0013 (RFMEFI61314X0013); and Russian Foundation for Basic Research (grants No. 14-05-00526 and 14-05-00590).

La binaria LSS 3074 y su entorno: ?`una nueva asociación OB?

NASA Astrophysics Data System (ADS)

Niemela, V.; Morrell, N.; Corti, M.

En este trabajo presentamos un nuevo análisis orbital de LSS~3074, junto con tipos espectrales y velocidades radiales de estrellas que podrían constituir con ella una nueva asociación OB. La estrella O4f LSS3074 fue descubierta como binaria espectroscópica de corto período y líneas dobles por Morrell & Niemela (1990, ASP Conf. Ser. 7, 57). Posteriormente, Haefner et~al.(1994, IBVS 3969) encontraron variaciones fotométricas, estimando una inclinación orbital entre 50o y 55o. Teniendo en cuenta la importancia de obtener valores empíricos para las masas de estrellas O tempranas, y considerando la gran dispersión existente entre los valores observados y su discrepancia con los predichos por los modelos teóricos, hemos obtenido nuevas observaciones espectroscópicas de este sistema, con el propósito de mejorar los elementos orbitales derivados en la solución preliminar. Además, como las estrellas O tempranas suelen formar parte de cúmulos y asociaciones OB, hemos llevado a cabo una investigación espectroscópica de varias estrellas tempranas que podrían estar físicamente relacionadas con LSS~3074.

Triggering risk factors of the burnout syndrome in OB/GYN physicians from a reference public university of Brazil.

PubMed

Ferreira Bortoletti, Fátima; Teresa Benevides-Pereira, Ana Maria; Vasconcellos, Esdras Guerreiro; Siqueira, José Oliveira; Araujo Júnior, Edward; Nardozza, Luciano Marcondes Machado; Sebastiani, Ricardo Werner; Moron, Antonio Fernandes

2012-01-01

Objective. To identify the risk factors to the development of Burnout Syndrome in Ob/Gyn Brazilian physicians in four dimensions: emotional exhaustion (EE), professional repression (PR), dehumanization (De), and emotional distancing (EmD). Methods. A prospective cross-sectional study was realized with 48 Ob/Gyn physicians (12 lecturers, 12 attending physicians, 12 medical residents, and 12 graduate students) from Department of Obstetrics, São Paulo Federal University (UNIFESP). We used a sociodemographic questionnaire focusing on the activities (administrative, educational, healthcare, and research). We applied a Burnout Syndrome Inventory (BSI) composed of two parts: triggering factors (ISB1) and the Burnout Syndrome (ISB2). The ISB1 is composed of two scales: positive organizational conditions (POC) and negative organizational conditions (NOC). The ISB2 is composed of four scales: EE, PR, De, and EmD. Results. We observed a rate below and above average to POC and NOC, respectively. The dimensions recorded a level above average to EE, an index at the upper limit of the average to De, a median index to EmD, and a median index to PR. Conclusions. The Ob/Gyn physicians are in an area of vulnerability for the development of Burnout Syndrome due to the high level of EE and De, associated with a median index of PR. The high rate of NOC contributes to the triggering of this scenery.

Triggering Risk Factors of the Burnout Syndrome in Ob/Gyn Physicians from a Reference Public University of Brazil

PubMed Central

Ferreira Bortoletti, Fátima; Teresa Benevides-Pereira, Ana Maria; Vasconcellos, Esdras Guerreiro; Siqueira, José Oliveira; Araujo Júnior, Edward; Nardozza, Luciano Marcondes Machado; Sebastiani, Ricardo Werner; Moron, Antonio Fernandes

2012-01-01

Objective. To identify the risk factors to the development of Burnout Syndrome in Ob/Gyn Brazilian physicians in four dimensions: emotional exhaustion (EE), professional repression (PR), dehumanization (De), and emotional distancing (EmD). Methods. A prospective cross-sectional study was realized with 48 Ob/Gyn physicians (12 lecturers, 12 attending physicians, 12 medical residents, and 12 graduate students) from Department of Obstetrics, São Paulo Federal University (UNIFESP). We used a sociodemographic questionnaire focusing on the activities (administrative, educational, healthcare, and research). We applied a Burnout Syndrome Inventory (BSI) composed of two parts: triggering factors (ISB1) and the Burnout Syndrome (ISB2). The ISB1 is composed of two scales: positive organizational conditions (POC) and negative organizational conditions (NOC). The ISB2 is composed of four scales: EE, PR, De, and EmD. Results. We observed a rate below and above average to POC and NOC, respectively. The dimensions recorded a level above average to EE, an index at the upper limit of the average to De, a median index to EmD, and a median index to PR. Conclusions. The Ob/Gyn physicians are in an area of vulnerability for the development of Burnout Syndrome due to the high level of EE and De, associated with a median index of PR. The high rate of NOC contributes to the triggering of this scenery. PMID:23304541

Colorectal cancer risk factors among the population of South-East Siberia: a case-control study.

PubMed

Zhivotovskiy, Alexey S; Kutikhin, Anton G; Azanov, Artur Z; Yuzhalin, Arseniy E; Magarill, Yuri A; Brusina, Elena B

2012-01-01

Colorectal cancer remains one of the most widespread malignancies in the world. However, there is a lack of comprehensive studies considering colorectal cancer risk factors among Russian populations, particularly in Siberia. The aim of this investigation was to determine the impact of various lifestyle, dietary, family, and socioeconomical factors on colorectal cancer risk in South-East Siberia. We recruited 185 Russian colorectal cancer cases and 210 gender-, age-, and ethnicity-matched asymptomatic controls with no history of any malignant tumor, using a specially designed questionnaire to obtain relevant information. After the statistical analysis, we defined several significant factors affecting colorectal cancer risk. Among these were smoking (OR=2.13, 95%CI=1.4- 3.24, P=0.0004), being overweight (BMI between 25-30, OR=2.45, 95%CI=1.49-4.03, P=0.0004), alcohol drinking (OR=8.73, 95%CI=5.49-13.87, P<0.0001), beer drinking (OR=9.24, 95%CI=5.14-16.61, P<0.0001), consumption of hard liquor (OR=9.37, 95%CI=5.92-14.82, P<0.0001), excessive red meat consumption (P<0.0001), excessive intake of red meat products (P<0.0001), excessive intake of dairy products (P<0.0001), excessive sour cream and cheese consumption (P<0.0001 and 0.0002, respectively), spicy food consumption (OR=2.87, 95%CI=1.9-4.33, P<0.0001), family history of gastrointestinal malignant tumors (OR=3.99, 95%CI=2.09-7.59, P<0.0001), and income exceeding twice the subsistence minimum (OR=5.34, 95%CI=3.35-8.53, P<0.0001). Certain factors, such as high concentration of salt in the food and precancerous colonic lesions, demonstrated borderline significance (OR=3.45, 95%CI=1.68-7.1, P=0.0008, and OR=5.25, 95%CI=1.94-14.22, P=0.001, respectively). Some factors were established as protective, like consumption of rye bread and both rye and wheat bread (OR=0.32, 95%CI=0.21-0.5, P<0,0001, and OR=0.07, 95%CI=0.02-0.21, P<0.0001, respectively), and also low concentration of salt in the food, although this was of

Identifying Massive Runaway Stars by Detecting Infrared Bowshock Nebula: Four OB Stars and a New Massive Early-B Binary System

NASA Astrophysics Data System (ADS)

Sorber, Rebecca L.; Rebecca L. Sorber, Henry A. Kobulnicky, Daniel A. Dale, Matthew S. Povich, William T. Chick, Heather N. Wernke, Julian E. Andrews, Stephan Munari, Grace M. Olivier, Danielle Schurhammer

2016-01-01

Though the main sequence evolution of OB type stars is relatively well known, the mass loss rates for these stars are still highly uncertain. Some OB stars are gravitationally ejected from their birth sites, traveling at speeds of 30 km/s or more which results in a prominent bowshock nebulae. We identified OB bowshock candidates at low Galactic latitudes by visual inspection of the Wide-field Infrared Survey Explorer (WISE) 22-micron images. Each candidate was observed using the Longslit Spectrograph at the Wyoming Infrared Observatory (WIRO) 2.3 meter telescope. We present here the results from observing four such candidates, and all four are confirmed as early type stars: GO92.3191+0.0591 (B1V) (aka ALS11826), GO86.551014-1.0873935 (B2V; a probable short-period binary), G076.6921-2.4071 (B5V), and G075.5711-0.2558 (B0V) (aka HD 194303). These results enlarge the sample of candidate runaway massive stars hosting bowshocks and provide a promising sample of such objects for studying stellar mass loss. This work is supported by the National Science Foundation Grants AST-1063146 (REU), AST-1411851 (RUI), and AST-1412845.

Redistribution of vegetation zones and populations of Larix sibirica Ledb. and Pinus sylvestris L. in central Siberia in a warming climate

Treesearch

N.M. Tchebakova; G.E. Rehfeldt; E.I. Parfenova

2003-01-01

Evidence for global warming over the past 200 years is overwhelming (Hulme et al. 1999), based on both direct weather observation and indirect physical and biological indicators such as retreating glaciers and snow/ice cover, increasing sea level, and longer growing seasons (IPCC 2001). Recent GCM projections of the Hadley Centre (Gordon et al. 2000) for Siberia show...

On the Binary Nature of Massive Blue Hypergiants: High-resolution X-Ray Spectroscopy Suggests That Cyg OB2 12 is a Colliding Wind Binary

NASA Astrophysics Data System (ADS)

Oskinova, L. M.; Huenemoerder, D. P.; Hamann, W.-R.; Shenar, T.; Sander, A. A. C.; Ignace, R.; Todt, H.; Hainich, R.

2017-08-01

The blue hypergiant Cyg OB2 12 (B3Ia+) is a representative member of the class of very massive stars in a poorly understood evolutionary stage. We obtained its high-resolution X-ray spectrum using the Chandra observatory. PoWR model atmospheres were calculated to provide realistic wind opacities and to establish the wind density structure. We find that collisional de-excitation is the dominant mechanism depopulating the metastable upper levels of the forbidden lines of the He-like ions Si xiv and Mg xii. Comparison between the model and observations reveals that X-ray emission is produced in a dense plasma, which could reside only at the photosphere or in a colliding wind zone between binary components. The observed X-ray spectra are well-fitted by thermal plasma models, with average temperatures in excess of 10 MK. The wind speed in Cyg OB2 12 is not high enough to power such high temperatures, but the collision of two winds in a binary system can be sufficient. We used archival data to investigate the X-ray properties of other blue hypergiants. In general, stars of this class are not detected as X-ray sources. We suggest that our new Chandra observations of Cyg OB2 12 can be best explained if Cyg OB2 12 is a colliding wind binary possessing a late O-type companion. This makes Cyg OB2 12 only the second binary system among the 16 known Galactic hypergiants. This low binary fraction indicates that the blue hypergiants are likely products of massive binary evolution during which they either accreted a significant amount of mass or already merged with their companions.

OB Stars and Cepheids From the Gaia TGAS Catalogue: Test of their Distances and Proper Motions

NASA Astrophysics Data System (ADS)

Bobylev, Vadim V.; Bajkova, Anisa T.

2017-12-01

We consider young distant stars from the Gaia TGAS catalog. These are 250 classical Cepheids and 244 OB stars located at distances up to 4 kpc from the Sun. These stars are used to determine the Galactic rotation parameters using both trigonometric parallaxes and proper motions of the TGAS stars. In this case the considered stars have relative parallax errors less than 200%. Following the well-known statistical approach, we assume that the kinematic parameters found from the line-of-sight velocities Vr are less dependent on errors of distances than the found from the velocity components Vl. From values of the first derivative of the Galactic rotation angular velocity '0, found from the analysis of velocities Vr and Vl separately, the scale factor of distances is determined.We found that from the sample of Cepheids the scale of distances of the TGAS should be reduced by 3%, and from the sample of OB stars, on the contrary, the scale should be increased by 9%.

Gammaproteobacterial Methanotrophs Dominate Cold Methane Seeps in Floodplains of West Siberian Rivers

PubMed Central

Oshkin, Igor Y.; Wegner, Carl-Eric; Lüke, Claudia; Glagolev, Mikhail V.; Filippov, Illiya V.; Pimenov, Nikolay V.; Liesack, Werner

2014-01-01

A complex system of muddy fluid-discharging and methane (CH4)-releasing seeps was discovered in a valley of the river Mukhrinskaya, one of the small rivers of the Irtysh Basin, West Siberia. CH4 flux from most (90%) of these gas ebullition sites did not exceed 1.45 g CH4 h−1, while some seeps emitted up to 5.54 g CH4 h−1. The δ13C value of methane released from these seeps varied between −71.1 and −71.3‰, suggesting its biogenic origin. Although the seeps were characterized by low in situ temperatures (3.5 to 5°C), relatively high rates of methane oxidation (15.5 to 15.9 nmol CH4 ml−1 day−1) were measured in mud samples. Fluorescence in situ hybridization detected 107 methanotrophic bacteria (MB) per g of mud (dry weight), which accounted for up to 20.5% of total bacterial cell counts. Most (95.8 to 99.3%) methanotroph cells were type I (gammaproteobacterial) MB. The diversity of methanotrophs in this habitat was further assessed by pyrosequencing of pmoA genes, encoding particulate methane monooxygenase. A total of 53,828 pmoA gene sequences of seep-inhabiting methanotrophs were retrieved and analyzed. Nearly all of these sequences affiliated with type I MB, including the Methylobacter-Methylovulum-Methylosoma group, lake cluster 2, and several as-yet-uncharacterized methanotroph clades. Apparently, microbial communities attenuating methane fluxes from these local but strong CH4 sources in floodplains of high-latitude rivers have a large proportion of potentially novel, psychrotolerant methanotrophs, thereby providing a challenge for future isolation studies. PMID:25063667

H-alpha Variability in the Young Open Cluster Cygnus OB2

NASA Astrophysics Data System (ADS)

Clarke, Seth; Hintz, Eric G.; Joner, Michael D.

2018-01-01

Observations of Cygnus OB2 were obtained in the filters detailed in Joner & Hintz (2015). For the last five years a block of data was secured using the BYU West Mountain 0.9-m telescope. Magnitudes were then determined using DAOPHOT in order to examine as many stars as possible on each frame. These magnitudes were then combined to generate the indexes from Joner & Hintz (2015). We will examine the overall cluster by using a color-color-magnitude plot. We will also present short term and long term time series measurements of a sample of variable objects in the field.

Relative importance of multiple factors on terrestrial loading of DOC to Arctic river networks

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

Kicklighter, David W.; Hayes, Daniel J; Mcclelland, James W

2014-01-01

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to controlling carbon fluxes between the land surface and the atmosphere. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that the pan-arctic watershed has contributed, on average, 32 Tg C/yr of DOC to the Arctic Ocean over the 20th century with most coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate ofmore » terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of increases in air temperatures and precipitation. These increases have been partially compensated by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both compensated and enhanced concurrent effects on hydrology to influence terrestrial DOC loading. Future increases in riverine DOC concentrations and export may occur from warming-induced increases in terrestrial DOC production associated with enhanced microbial metabolism and the exposure of additional organic matter from permafrost degradation along with decreases in water yield associated with warming-induced increases in evapotranspiration. Improvements in simulating terrestrial DOC loading to pan-arctic rivers in the future will require better information on the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in

Morphology and biology of Cyclops scutifer Sars, 1863 in high mountain lakes of East Siberia (including Lake Amut)

NASA Astrophysics Data System (ADS)

Sheveleva, Natalya G.; Itigilova, Mydygma Ts.; Chananbaator, Ayushcuren

2017-03-01

Data on zooplankton from 13 high-mountain lakes of East Siberia have shown that the Holarctic copepod Cyclops scutifer Sars, 1863 dominates among crustaceans. In July, its abundance comprised 64%-98% of the total plankton fauna in the pelagial of these lakes, approximately 30% in the littoral zone and 10% in small northern thermokarst lakes. Biometric measurements and morphological descriptions based on scanning microscope images are supplemented by the data on its geographic distribution and phenology.

MUG-OBS - Multiparameter Geophysical Ocean Bottom System : a new instrumental approach to monitor earthquakes.

NASA Astrophysics Data System (ADS)

hello, yann; Charvis, Philippe; Yegikyan, Manuk; verfaillie, Romain; Rivet, Diane

2016-04-01

Real time monitoring of seismic activity is a major issue for early warning of earthquakes and tsunamis. It can be done using regional scale wired nodes, such as Neptune in Canada and in the U.S, or DONET in Japan. Another approach to monitor seismic activity at sea is to deploying repeatedly OBS array like during the amphibious Cascadia Initiative (four time 1-year deployments), the Japanese Pacific Array (broadband OBSs "ocean-bottom broadband dispersion survey" with 2-years autonomy), the Obsismer program in the French Lesser Antilles (eight time 6-months deployments) and the Osisec program in Ecuador (four time 6-months deployments). These autonomous OBSs are self-recovered or recovered using an ROV. These systems are costly including ship time, and require to recover the OBS before to start working on data. Among the most recent alternative we developed a 3/4 years autonomy ocean bottom system with 9 channels (?) allowing the acquisition of different seismic or environmental parameters. MUG-OBS is a free falling instrument rated down to 6000 m. The installation of the sensor is monitored by acoustic commands from the surface and a health bulletin with data checking is recovered by acoustic during the installation. The major innovation is that it is possible to recover the data any time on demand (regularly every 6-months or after a crisis) using one of the 6 data-shuttles released from the surface by acoustic command using a one day fast cruise boat of opportunity. Since sensors stayed at the same location for 3 years, it is a perfect tool to monitor large seismic events, background seismic activity and aftershock distribution. Clock, drift measurement and GPS localization is automatic when the shuttle reaches the surface. For remote areas, shuttles released automatically and a seismic events bulletin is transmitted. Selected data can be recovered by two-way Iridium satellite communication. After a period of 3 years the main station is self-recovered by

Nature vs. Nurture: The influence of OB star environments on proto-planetary disk evolution.

NASA Astrophysics Data System (ADS)

Bouwman, Jeroen; Feigelson, Eric; Getman, Kostantin; Henning, Thomas; Lawson, Warrick; Linz, Hendrik; Luhman, Kevin; Roccatagliata, Veronica; Sicilia Aguilar, Aurora; Townsley, Leisa; Wang, Junfeng

2006-05-01

A natural approach for understanding the origin and diversity of planetary systems is to study the birth sites of planetary systems under varying environmental conditions. Dust grains in protoplanetary disks, the building blocks of planets, are structurally and chemically altered, and grow through coagulation into planetesimals. The disk geometry may change from a flaring to a more flattened structure, gaps may develop under the gravitational influence of protoplanets, and eventually the disk will dissipate, terminating the planet formation process. While the infrared properties of disks in quiet cloud environments have been extensively studied, investigations under the conditions of strong UV radiation and stellar winds in the proximity of OB stars have been limited. We propose a combined IRAC/IRS study of a large, well-defined and unbiased X-ray selected sample of pre-main-sequence stars in three OB associations: Pismis 24 in NGC 6357, NGC 2244 in the Rosette Nebula, and IC 1795 in the W3 complex. The samples are based on recent Chandra X-ray Observatory studies which reliably identify hundreds of cluster members and were carefully chosen to avoid high infrared nebular background. A new Chandra exposure of IC 1795 is requested, and an optical followup to characterise the host stars is planned. Modelling the Spitzer findings will provide the composition and size of dust present as well as the geometry, mass, and gaps in the global structure of the disk. As hundreds of cluster members will be covered with IRAC and dozens with IRS, good statistics on the disk evolution and dispersal as a function of location with respect to OB stars will be obtained. Comparison of disk properties within our sample and with existing Spitzer studies of quiescent star-forming regions should significantly advance the aim of characterising the influence of the environment on the evolution of protoplanetary disks. This effort relies on a powerful synergy between the Chandra and Spitzer

Search for OB stars running away from young star clusters. II. The NGC 6357 star-forming region

NASA Astrophysics Data System (ADS)

Gvaramadze, V. V.; Kniazev, A. Y.; Kroupa, P.; Oh, S.

2011-11-01

Dynamical few-body encounters in the dense cores of young massive star clusters are responsible for the loss of a significant fraction of their massive stellar content. Some of the escaping (runaway) stars move through the ambient medium supersonically and can be revealed via detection of their bow shocks (visible in the infrared, optical or radio). In this paper, which is the second of a series of papers devoted to the search for OB stars running away from young ( ≲ several Myr) Galactic clusters and OB associations, we present the results of the search for bow shocks around the star-forming region NGC 6357. Using the archival data of the Midcourse Space Experiment (MSX) satellite and the Spitzer Space Telescope, and the preliminary data release of the Wide-Field Infrared Survey Explorer (WISE), we discovered seven bow shocks, whose geometry is consistent with the possibility that they are generated by stars expelled from the young (~1-2 Myr) star clusters, Pismis 24 and AH03 J1725-34.4, associated with NGC 6357. Two of the seven bow shocks are driven by the already known OB stars, HD 319881 and [N78] 34. Follow-up spectroscopy of three other bow-shock-producing stars showed that they are massive (O-type) stars as well, while the 2MASS photometry of the remaining two stars suggests that they could be B0 V stars, provided that both are located at the same distance as NGC 6357. Detection of numerous massive stars ejected from the very young clusters is consistent with the theoretical expectation that star clusters can effectively lose massive stars at the very beginning of their dynamical evolution (long before the second mechanism for production of runaway stars, based on a supernova explosion in a massive tight binary system, begins to operate) and lends strong support to the idea that probably all field OB stars have been dynamically ejected from their birth clusters. A by-product of our search for bow shocks around NGC 6357 is the detection of three circular

L'obésité en consultation cardiologique à Lomé: prévalence et facteurs de risque cardio-vasculaire associés - étude chez 1200 patients

PubMed Central

Pessinaba, Soulemane; Yayehd, Komlavi; Pio, Machiude; Baragou, Réné; Afassinou, Yaovi; Tchérou, Tchaa; Damorou, Findibé

2012-01-01

Introduction Introduction: Les objectifs de ce travail étaient de déterminer la fréquence de l'obésité et celle des autres facteurs de risque cardio-vasculaire chez ces patients obèses à Lomé (Togo). Méthodes Il s'est agi d'une étude multicentrique transversale de prévalence. Elle s'est déroulée du 05 septembre 2005 au 04 mars 2006 et a porté sur les malades vus en consultation externe dans 3 services de cardiologie de la commune de Lomé. Ont été inclus dans cette étude les malades ayant un surpoids selon les normes de l'OMS. Résultats Parmi 1200 patients vus en consultations, 779 (64,92%) avaient une surcharge pondérale. L’âge moyen était de 49,53 ± 17,24 ans. L'obésité était plus fréquente chez les femmes (79,49%) que chez les hommes (20,51%). Un antécédent d'obésité familiale (61,8%) était le principal facteur favorisant. Les autres facteurs de risque cardio-vasculaire retrouvés étaient: sédentarité (82% vs50% chez les non obèses), hypertension artérielle (54,8% vs 39,2%), alcool (50,9% vs 43,9%), dyslipidémie (34,5% vs 20%), diabète (30,9% vs 10,7%) et tabac (14,1% vs 20,3%). La différence était statistiquement significative entre les deux groupes. Les principales complications cardiovasculaires observées chez les obèses étaient: l'ischémie myocardique (26,7%), l'hypertrophie ventriculaire gauche (46,4%), la dilatation cavitaire cardiaque (30,1%) et les accidents vasculaires cérébraux (7,1%). Conclusion L'obésité est un problème de santé publique au Togo. Sa prévalence est très élevée et elle est le plus souvent associée aux autres facteurs de risque cardio-vasculaire. Des mesures préventives doivent être mises en jeu pour lutter contre ce facteur de risque. Mots clés: Obésité, prévalence, facteurs de risque. PMID:23133699

Beyond the Ivory Tower: A Comparison of Grades Across Academic and Community OB/GYN Clerkship Sites.

PubMed

Fay, Emily E; Schiff, Melissa A; Mendiratta, Vicki; Benedetti, Thomas J; Debiec, Kate

2016-01-01

CONSTRUCT: Decentralized clinical education is the use of community facilities and community physicians to educate medical students. The theory behind decentralized clinical education is that academic and community sites will provide educational equivalency as determined by objective and subjective performance measures, while training more medical students and exposing students to rural or underserved communities. One of the major challenges of decentralized clinical education is ensuring site comparability in both learning opportunities and evaluation of students. Previous research has examined objective measures of student performance, but less is known about subjective performance measures, particularly in the field of obstetrics and gynecology (OB/GYN). This study explores the implications of clinical site on the adequacy of subjective and objective performance measures. This was a retrospective cohort study of 801 students in the University of Washington School of Medicine OB/GYN clerkship from 2008 to 2012. Academic sites included those with OB/GYN residency programs (n = 2) and community sites included those without residency programs (n = 29). The association between clerkship site and National Board of Medical Examiners (NBME) grade was assessed using linear regression and clinical and final grade using multinomial regression, estimating β coefficient and relative risks (RR), respectively, and 95% confidence intervals (CIs), adjusting for gender, academic quarter of clerkship, and year of clerkship. There were no differences in NBME exam grades of students at academic sites (76.4 (7.3) versus 74.6 (8.0), β = -0.11, 95% CI [1.35, 1.12] compared to community sites. For clinical grade, students at community sites were 2.4 times more likely to receive honors relative to high pass (RR 2.45), 95% CI [1.72, 3.50], and for final grade, students at community sites were 1.9 times more likely to receive honors relative to pass (RR 1.98), 95% CI [1.27, 3.09], and 1

Accretion and outflow in the proplyd-like objects near Cygnus OB2

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

Guarcello, M. G.; Drake, J. J.; Wright, N. J.

2014-09-20

Cygnus OB2 is the most massive association within 2 kpc from the Sun, hosting hundreds of massive stars, thousands of young low mass members, and some sights of active star formation in the surrounding cloud. Recently, 10 photoevaporating proplyd-like objects with tadpole-shaped morphology were discovered in the outskirts of the OB association, approximately 6-14 pc away from its center. The classification of these objects is ambiguous, being either evaporating residuals of the parental cloud that are hosting a protostar inside or disk-bearing stars with an evaporating disk, such as the evaporating proplyds observed in the Trapezium Cluster in Orion. Inmore » this paper, we present a study based on low-resolution optical spectroscopic observations made with the Optical System for Imaging and low Resolution Integrated Spectroscopy, mounted on the 10.4 m Gran Telescopio CANARIAS, of two of these protostars. The spectrum of one of the objects shows evidence of accretion but not of outflows. In the latter object, the spectra show several emission lines indicating the presence of an actively accreting disk with outflow. We present estimates of the mass loss rate and the accretion rate from the disk, showing that the former exceeds the latter as observed in other known objects with evaporating disks. We also show evidence of a strong variability in the integrated flux observed in these objects as well as in the accretion and outflow diagnostics.« less

Morphotectonic analysis and 10Be dating of the Kyngarga river terraces (southwestern flank of the Baikal rift system, South Siberia)

NASA Astrophysics Data System (ADS)

Arzhannikova, A.; Arzhannikov, S.; Braucher, R.; Jolivet, M.; Aumaître, G.; Bourlès, D.; Keddadouche, K.

2018-02-01

The formation of the Baikal rift system basins is controlled by active faults separating each basin from the adjacent horsts. The kinematics of these faults is mainly explored through investigation of complex sequences of the fault-intersecting river terraces that record both tectonic and climatic events. This study focuses on the northern margin of the major Tunka basin that develops south-west of Lake Baikal. The development of the basin is controlled by the segmented Tunka fault. We performed a detailed mapping of the Kyngarga river terraces, the best preserved terraces staircase in Baikal rift system, at their intersection with the Tunka fault. In order to decipher the chronology of seismic events and the slip rates along that segment of the fault, key terraces were dated using in situ produced cosmogenic 10Be. We demonstrate that the formation of the terrace staircase occurred entirely during MIS1-MIS2. The obtained data allowed us to estimate the rate of incision at different stages of the terrace staircase formation and the relationship between the vertical and horizontal slip rates along this sub-latitudinal segment of the Tunka fault making respectively 0.8 and 1.12 mm yr- 1 over the past 12.5 ka. Analysis of the paleoseismology and paleoclimate data together with terrace dating provided the possibility to estimate the influence of tectonic and climatic factors on the terrace formation. Our proposed model of the Kyngarga river terrace development shows that the incisions into terraces T3 and T6 were induced by the abrupt climatic warming episodes GI-1 and GI-2, respectively, whereas terraces T5, T4 and T2 were abandoned due to the vertical tectonic displacement along the Tunka fault caused by coseismic ruptures.

Satellite Analysis of the Severe 1987 Forest Fires in Northern China and Southeastern Siberia

NASA Technical Reports Server (NTRS)

Cahoon, Donald R., Jr.; Stocks, Brian J.; Levine, Joel S.; Cofer, Wesley R., III; Pierson, Joseph M.

1994-01-01

Meteorological conditions, extremely conducive to fire development and spread in the spring of 1987, resulted in forest fires burning over extremely large areas in the boreal forest zone in northeastern China and the southeastern region of Siberia. The great China fire, one of the largest and most destructive forest fires in recent history, occurred during this period in the Heilongjiang Province of China. Satellite imagery is used to examine the development and areal distribution of 1987 forest fires in this region. Overall trace gas emissions to the atmosphere from these fires are determined using a satellite-derived estimate of area burned in combination with fuel consumption figures and carbon emission ratios for boreal forest fires.

Satellite analysis of the severe 1987 forest fires in northern China and southeastern Siberia

NASA Technical Reports Server (NTRS)

Cahoon, Donald R, Jr.; Stocks, Brian J.; Levine, Joel S.; Cofer, Wesley R., III; Pierson, Joseph M.

1994-01-01

Meteorological conditions, extremely conducive to fire development and spread in the spring of 1987, resulted in forest fires burning over extremely large areas in the boreal forest zone in northeastern China and the southeastern region of Siberia. The great China fire, one of the largest and most destructive forest fires in recent history, occurred during this period in the Heilongjiang Province of China. Satellite imagery is used to examine the development and areal distribution of 1987 forest fires in this region. Overall trace gas emissions to the atmosphere from these fires are determined using a satellite-derived estimate of area burned in combination with fuel consumption figures and carbon emission ratios for boreal forest fires.

On the Binary Nature of Massive Blue Hypergiants: High-resolution X-Ray Spectroscopy Suggests That Cyg OB2 12 is a Colliding Wind Binary

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

Oskinova, L. M.; Hamann, W.-R.; Shenar, T.

The blue hypergiant Cyg OB2 12 (B3Ia{sup +}) is a representative member of the class of very massive stars in a poorly understood evolutionary stage. We obtained its high-resolution X-ray spectrum using the Chandra observatory. PoWR model atmospheres were calculated to provide realistic wind opacities and to establish the wind density structure. We find that collisional de-excitation is the dominant mechanism depopulating the metastable upper levels of the forbidden lines of the He-like ions Si xiv and Mg xii. Comparison between the model and observations reveals that X-ray emission is produced in a dense plasma, which could reside only atmore » the photosphere or in a colliding wind zone between binary components. The observed X-ray spectra are well-fitted by thermal plasma models, with average temperatures in excess of 10 MK. The wind speed in Cyg OB2 12 is not high enough to power such high temperatures, but the collision of two winds in a binary system can be sufficient. We used archival data to investigate the X-ray properties of other blue hypergiants. In general, stars of this class are not detected as X-ray sources. We suggest that our new Chandra observations of Cyg OB2 12 can be best explained if Cyg OB2 12 is a colliding wind binary possessing a late O-type companion. This makes Cyg OB2 12 only the second binary system among the 16 known Galactic hypergiants. This low binary fraction indicates that the blue hypergiants are likely products of massive binary evolution during which they either accreted a significant amount of mass or already merged with their companions.« less

Impacts of river segmentation strategies on reach-averaged product uncertainties for the upcoming Surface Water and Ocean Topography (SWOT) mission

NASA Astrophysics Data System (ADS)

Frasson, R. P. M.; Wei, R.; Minear, J. T.; Tuozzolo, S.; Domeneghetti, A.; Durand, M. T.

2016-12-01

Averaging is a powerful method to reduce measurement noise associated with remote sensing observation of water surfaces. However, when dealing with river measurements, the choice of which points are averaged may affect the quality of the products. We examine the effectiveness of three fully automated reach definition strategies: In the first, we break up reaches at regular intervals measured along the rivers' centerlines. The second strategy consists of identifying hydraulic controls by searching for inflection points on water surface profiles. The third strategy takes into consideration river planform features, breaking up reaches according to channel sinuosity. We employed the Jet Propulsion Laboratory's (JPL) SWOT hydrology simulator to generate 9 synthetic SWOT observations of the Sacramento River in California, USA and 14 overpasses of the Po River in northern Italy. In order to create the synthetic SWOT data, the simulator requires the true water digital elevation model (DEM), which we constructed from hydraulic models of both rivers, and the terrain DEM, which we built from LiDAR data of both basins. We processed the simulated pixel clouds using the JPL's RiverObs package, which traces the river centerline and estimates water surface height and river width on equally spaced nodes located along the centerline. Subsequently, we applied the three reach definition methodologies to the nodes and to the hydraulic models' outputs to generate simulated reach-averaged observations and the reach-averaged truth respectively. Our results generally indicate that height, width, slope, and discharge errors decrease with increasing reach length, with most of the accuracy gains occurring when reach length increases to up to 15 km for both the narrow (Sacramento) and the wide (Po) rivers. The "smart" methods led to smaller slope, width, and discharge errors for the Sacramento River when compared to arbitrary reaches of similar length whereas, for the for the Po River all

Hypothyroidism reduces ObRb-STAT3 leptin signalling in the hypothalamus and pituitary of rats associated with resistance to leptin acute anorectic action.

PubMed

Calvino, Camila; Souza, Luana L; Costa-e-Sousa, Ricardo H; Almeida, Norma A S; Trevenzoli, Isis H; Pazos-Moura, Carmen C

2012-10-01

Leptin has been shown to regulate the hypothalamus-pituitary-thyroid axis, acting primarily through the STAT3 pathway triggered through the binding of leptin to the long-chain isoform of the leptin receptor, ObRb. We previously demonstrated that although hyperthyroid rats presented leptin effects on TSH secretion, those effects were abolished in hypothyroid rats. We addressed the hypothesis that changes in the STAT3 pathway might explain the lack of TSH response to leptin in hypothyroidism by evaluating the protein content of components of leptin signalling via the STAT3 pathway in the hypothalamus and pituitary of hypothyroid (0·03% methimazole in the drinking water/21 days) and hyperthyroid (thyroxine 5 μg/100 g body weight /5 days) rats. Hypothyroid rats exhibited decreased ObRb and phosphorylated STAT3 (pSTAT3) protein in the hypothalamus, and in the pituitary gland they exhibited decreased ObRb, total STAT3, pSTAT3 and SOCS3 (P<0·05). Except for a modest decrease in pituitary STAT3, no other alterations were observed in hyperthyroid rats. Moreover, unlike euthyroid rats, the hypothyroid rats did not exhibit a reduction in food ingestion after a single injection of leptin (0·5 mg/kg body weight). Therefore, hypothyroidism decreased ObRb-STAT3 signalling in the hypothalamus and pituitary gland, which likely contributes to the loss of leptin action on food intake and TSH secretion, as previously observed in hypothyroid rats.

The diversity and prevalence of hard ticks attacking human hosts in Eastern Siberia (Russian Federation) with first description of invasion of non-endemic tick species.

PubMed

Khasnatinov, Maxim Anatolyevich; Liapunov, Alexander Valeryevich; Manzarova, Ellina Lopsonovna; Kulakova, Nina Viktorovna; Petrova, Irina Viktorovna; Danchinova, Galina Anatolyevna

2016-02-01

Hard ticks are the vectors of many pathogens including tick-borne encephalitis virus and the Lyme disease agent Borrelia burgdorferi sensu lato. In Eastern Siberia, Ixodes persulcatus, Dermacentor nuttalli, Dermacentor silvarum and Haemaphysalis concinna are regarded as aggressive to humans. Recently, significant changes in world tick fauna have been reported and this affects the spread of tick-borne pathogens. We studied the current species diversity, population structure and prevalence of tick-borne pathogens of hard ticks (Acari: Ixodidae) that attacked humans in Eastern Siberia (Irkutsk region, Russia). In total, 31,892 individual ticks were identified and analysed during the years 2007-2014. The majority (85.4%) of victims was bitten by I. persulcatus, 14.55% of attacks on humans were caused by D. nuttalli and D. silvarum, whereas H. concinna was documented only in 15 cases (0.05%). The seasonal activity and the age/gender structure of the tick population were studied as well. Among all the studied ticks, three unconventional species, i.e. Rhipicephalus sanguineus, Dermacentor reticulatus and Amblyomma americanum, were identified. Analysis of tick bite histories indicates at least three events of invasion of non-endemic ticks into the ecosystems of northern Eurasia with harsh continental climates. Invading ticks are able to reach the adult life stage and are aggressive to the local human population. Phylogenetic analysis of mt 16S rRNA gene fragments suggests multiple independent routes of tick migration to Eastern Siberia. Possible implications to human health and epidemiology of tick-borne infections are discussed.

Burying Dogs in Ancient Cis-Baikal, Siberia: Temporal Trends and Relationships with Human Diet and Subsistence Practices

PubMed Central

Losey, Robert J.; Garvie-Lok, Sandra; Leonard, Jennifer A.; Katzenberg, M. Anne; Germonpré, Mietje; Nomokonova, Tatiana; Sablin, Mikhail V.; Goriunova, Olga I.; Berdnikova, Natalia E.; Savel’ev, Nikolai A.

2013-01-01

The first objective of this study is to examine temporal patterns in ancient dog burials in the Lake Baikal region of Eastern Siberia. The second objective is to determine if the practice of dog burial here can be correlated with patterns in human subsistence practices, in particular a reliance on terrestrial mammals. Direct radiocarbon dating of a suite of the region’s dog remains indicates that these animals were given burial only during periods in which human burials were common. Dog burials of any kind were most common during the Early Neolithic (∼7–8000 B.P.), and rare during all other time periods. Further, only foraging groups seem to have buried canids in this region, as pastoralist habitation sites and cemeteries generally lack dog interments, with the exception of sacrificed animals. Stable carbon and nitrogen isotope data indicate that dogs were only buried where and when human diets were relatively rich in aquatic foods, which here most likely included river and lake fish and Baikal seal (Phoca sibirica). Generally, human and dog diets appear to have been similar across the study subregions, and this is important for interpreting their radiocarbon dates, and comparing them to those obtained on the region’s human remains, both of which likely carry a freshwater old carbon bias. Slight offsets were observed in the isotope values of dogs and humans in our samples, particularly where both have diets rich in aquatic fauna. This may result from dietary differences between people and their dogs, perhaps due to consuming fish of different sizes, or even different tissues from the same aquatic fauna. This paper also provides a first glimpse of the DNA of ancient canids in Northeast Asia. PMID:23696851

Dinosaur evolution. A Jurassic ornithischian dinosaur from Siberia with both feathers and scales.

PubMed

Godefroit, Pascal; Sinitsa, Sofia M; Dhouailly, Danielle; Bolotsky, Yuri L; Sizov, Alexander V; McNamara, Maria E; Benton, Michael J; Spagna, Paul

2014-07-25

Middle Jurassic to Early Cretaceous deposits from northeastern China have yielded varied theropod dinosaurs bearing feathers. Filamentous integumentary structures have also been described in ornithischian dinosaurs, but whether these filaments can be regarded as part of the evolutionary lineage toward feathers remains controversial. Here we describe a new basal neornithischian dinosaur from the Jurassic of Siberia with small scales around the distal hindlimb, larger imbricated scales around the tail, monofilaments around the head and the thorax, and more complex featherlike structures around the humerus, the femur, and the tibia. The discovery of these branched integumentary structures outside theropods suggests that featherlike structures coexisted with scales and were potentially widespread among the entire dinosaur clade; feathers may thus have been present in the earliest dinosaurs. Copyright © 2014, American Association for the Advancement of Science.

Work and Family Research in IO/OB: Content Analysis and Review of the Literature (1980-2002)

ERIC Educational Resources Information Center

Eby, Lillian T.; Casper, Wendy J.; Lockwood, Angie; Bordeaux, Chris; Brinley, Andi

2005-01-01

This monograph reviews 190 work-family studies published in IO/OB journals from 1980 to 2002. The results of a content analysis are presented which catalog these articles with respect to the study focus, nature and direction of the proposed effects, and predictor, criterion, and mediator variables examined. Then a narrative review of the articles…

Food and water security issues in Russia III: food- and waterborne diseases in the Russian Arctic, Siberia and the Far East, 2000-2011.

PubMed

Dudarev, Alexey A; Dorofeyev, Vitaliy M; Dushkina, Eugenia V; Alloyarov, Pavel R; Chupakhin, Valery S; Sladkova, Yuliya N; Kolesnikova, Tatjana A; Fridman, Kirill B; Nilsson, Lena Maria; Evengard, Birgitta

2013-01-01

The food- and waterborne disease situation in Russia requires special attention. Poor quality of centralized water supplies and sewage systems, biological and chemical contamination of drinking water, as well as contamination of food products, promote widespread infectious diseases, significantly exceeding nationwide rates in the population living in the two-thirds of Russian northern territories. The general aim was to assess the levels of food- and waterborne diseases in selected regions of Russian Arctic, Siberia and the Far East (for the period 2000-2011), and to compare disease levels among regions and with national levels in Russia. This study is the first comparative assessment of the morbidity in these fields of the population of 18 selected regions of Russian Arctic, Siberia and the Far East, using official statistical sources. The incidences of infectious and parasitic food- and waterborne diseases among the general population (including indigenous peoples) have been analyzed in selected regions (per 100,000 of population, averaged for 2000-2011). Among compulsory registered infectious and parasitic diseases, there were high rates and widespread incidences in selected regions of shigellosis, yersiniosis, hepatitis A, tularaemia, giardiasis, enterobiasis, ascariasis, diphyllobothriasis, opistorchiasis, echinococcosis and trichinellosis. Incidences of infectious and parasitic food- and waterborne diseases in the general population of selected regions of the Russian Arctic, Siberia and the Far East (2000-2011) are alarmingly high. Parallel solutions must be on the agenda, including improvement of sanitary conditions of cities and settlements in the regions, modernization of the water supply and of the sewage system. Provision and monitoring of the quality of the drinking water, a reform of the general healthcare system and the epidemiological surveillance (including gender-divided statistics), enhancement of laboratory diagnostics and the introduction of

A proposed OB-fold with a protein-interaction surface in Candida albicans telomerase protein Est3

PubMed Central

Yu, Eun Young; Wang, Feng; Lei, Ming; Lue, Neal F

2008-01-01

Ever shorter telomeres 3 (Est3) is an essential telomerase regulatory subunit thought to be unique to budding yeasts. Here we use multiple sequence alignment and hidden Markov model–hidden Markov model (HMM-HMM) comparison to uncover potential similarities between Est3 and the mammalian telomeric protein Tpp1. Analysis of site-specific mutants of Candida albicans Est3 revealed functional distinctions between residues that are conserved between Est3 and Tpp1 and those that are unique to Est3. Although both types of residues are important for telomere maintenance in vivo, only the former contributes to telomerase activity in vitro and facilitates the association of Est3 with telomerase core components. Consistent with a function in protein-protein interaction, the residues common to Est3 and Tpp1 map to one face of an OB-fold model structure, away from the canonical nucleic acid binding surface. We propose that Est3 and the OB-fold domain of Tpp1 mediate a conserved function in telomerase regulation. PMID:19172753

Draft genome sequence of Mycobacterium tuberculosis strain B9741 of Beijing B0/W lineage from HIV positive patient from Siberia.

PubMed

Shur, K V; Zaychikova, M V; Mikheecheva, N E; Klimina, K M; Bekker, O B; Zhdanova, S N; Ogarkov, O B; Danilenko, V N

2016-12-01

We report a draft genome sequence of Mycobacterium tuberculosis strain B9741 belonging to Beijing B0/W lineage isolated from a HIV patient from Siberia, Russia. This clinical isolate showed MDR phenotype and resistance to isoniazid, rifampin, streptomycin and pyrazinamide. We analyzed SNPs associated with virulence and resistance. The draft genome sequence and annotation have been deposited at GenBank under the accession NZ_LVJJ00000000.

Sources of particulate organic matter discharged by the Lena River using lignin phenols

NASA Astrophysics Data System (ADS)

Winterfeld, M.; Trojahn, S.; Hefter, J.; Pittauer, D.; Zubrzycki, S.; Han, P.; Rethemeyer, J.; Mollenhauer, G.

2016-12-01

Particulate organic matter (POM) discharged by rivers and deposited offshore their mouths is generally assumed to record an integrated signal from the watershed and therefore provides an archive of past environmental changes. Yet, in large river systems the riverine POM might be trapped in flood plains and the lower reaches resulting in an inefficient transport of POM particularly from the distal parts of the watershed. Further, the POM likely undergoes degradation during transport from source to sink. The Lena River is one of these large river systems stretching from 53°N to 71°N in central Siberia. The watershed can be broadly divided into two different biomes, taiga in the south and tundra in the northernmost part. The relative contribution of these biomes to the POM load of the river and its discharge to the ocean as well as the changes it is undergoing during transport are not well understood. Here we present the lignin phenol composition of different grain size fractions (bulk, 2mm-63µm, <63µm) of soil samples taken along a latitudinal transect (63°N to 72°N) as well as in marine surface sediments and two short sediment cores covering the last 120 years offshore the main Lena discharge channels. The lignin phenol composition of the soil samples (bulk, 2mm-63µm, <63µm) reflects the change in vegetation from south to north with increasing contribution of tundra vegetation. The degree of degradation between the soil sample locations as well as grain size fractions was very heterogeneous and did not show a clear trend. However, the POM seems to be slightly more degraded in the tundra, which is unexpected as the summer period when degradation in the upper thawed part of the soil can take place is shorter in the tundra compared to the southern taiga region. The marine surface sediments were dominated by gymnosperm-derived POM, particularly close to the river mouth and in the <63µm fraction. Because of the large heterogeneity of organic matter degradation

Carbenoxolone Treatment Ameliorated Metabolic Syndrome in WNIN/Ob Obese Rats, but Induced Severe Fat Loss and Glucose Intolerance in Lean Rats

PubMed Central

Prasad Sakamuri, Siva Sankara Vara; Sukapaka, Mahesh; Prathipati, Vijay Kumar; Nemani, Harishankar; Putcha, Uday Kumar; Pothana, Shailaja; Koppala, Swarupa Rani; Ponday, Lakshmi Raj Kumar; Acharya, Vani; Veetill, Giridharan Nappan; Ayyalasomayajula, Vajreswari

2012-01-01

Background 11beta-hydroxysteroid dehydrogenase type 1 (11β-HSD1) regulates local glucocorticoid action in tissues by catalysing conversion of inactive glucocorticoids to active glucocorticoids. 11β-HSD1 inhibition ameliorates obesity and associated co-morbidities. Here, we tested the effect of 11β-HSD inhibitor, carbenoxolone (CBX) on obesity and associated comorbidities in obese rats of WNIN/Ob strain, a new animal model for genetic obesity. Methodology/Principal Findings Subcutaneous injection of CBX (50 mg/kg body weight) or volume-matched vehicle was given once daily for four weeks to three month-old WNIN/Ob lean and obese rats (n = 6 for each phenotype and for each treatment). Body composition, plasma lipids and hormones were assayed. Hepatic steatosis, adipose tissue morphology, inflammation and fibrosis were also studied. Insulin resistance and glucose intolerance were determined along with tissue glycogen content. Gene expressions were determined in liver and adipose tissue. CBX significantly inhibited 11β-HSD1 activity in liver and adipose tissue of WNIN/Ob lean and obese rats. CBX significantly decreased body fat percentage, hypertriglyceridemia, hypercholesterolemia, insulin resistance in obese rats. CBX ameliorated hepatic steatosis, adipocyte hypertrophy, adipose tissue inflammation and fibrosis in obese rats. Tissue glycogen content was significantly decreased by CBX in liver and adipose tissue of obese rats. Severe fat loss and glucose- intolerance were observed in lean rats after CBX treatment. Conclusions/Significance We conclude that 11β-HSD1 inhibition by CBX decreases obesity and associated co-morbidities in WNIN/Ob obese rats. Our study supports the hypothesis that inhibition of 11β-HSD1 is a key strategy to treat metabolic syndrome. Severe fat loss and glucose -intolerance by CBX treatment in lean rats suggest that chronic 11β-HSD1 inhibition may lead to insulin resistance in normal conditions. PMID:23284633

Plant response to climate change along the forest-tundra ecotone in northeastern Siberia.

PubMed

Berner, Logan T; Beck, Pieter S A; Bunn, Andrew G; Goetz, Scott J

2013-11-01

Russia's boreal (taiga) biome will likely contract sharply and shift northward in response to 21st century climatic change, yet few studies have examined plant response to climatic variability along the northern margin. We quantified climate dynamics, trends in plant growth, and growth-climate relationships across the tundra shrublands and Cajander larch (Larix cajanderi Mayr.) woodlands of the Kolyma river basin (657 000 km(2) ) in northeastern Siberia using satellite-derived normalized difference vegetation indices (NDVI), tree ring-width measurements, and climate data. Mean summer temperatures (Ts ) increased 1.0 °C from 1938 to 2009, though there was no trend (P > 0.05) in growing year precipitation or climate moisture index (CMIgy ). Mean summer NDVI (NDVIs ) increased significantly from 1982 to 2010 across 20% of the watershed, primarily in cold, shrub-dominated areas. NDVIs positively correlated (P < 0.05) with Ts across 56% of the watershed (r = 0.52 ± 0.09, mean ± SD), principally in cold areas, and with CMIgy across 9% of the watershed (r = 0.45 ± 0.06), largely in warm areas. Larch ring-width measurements from nine sites revealed that year-to-year (i.e., high-frequency) variation in growth positively correlated (P < 0.05) with June temperature (r = 0.40) and prior summer CMI (r = 0.40) from 1938 to 2007. An unexplained multi-decadal (i.e., low-frequency) decline in annual basal area increment (BAI) occurred following the mid-20th century, but over the NDVI record there was no trend in mean BAI (P > 0.05), which significantly correlated with NDVIs (r = 0.44, P < 0.05, 1982-2007). Both satellite and tree-ring analyses indicated that plant growth was constrained by both low temperatures and limited moisture availability and, furthermore, that warming enhanced growth. Impacts of future climatic change on forests near treeline in Arctic Russia will likely be influenced by shifts in both temperature and moisture, which implies

Lower Troposphere Stratification and Pollutant Transport over Siberia in April 2006

NASA Astrophysics Data System (ADS)

Paris, J.; Nedelec, P.; Ramonet, M.; Golitsyn, G. S.; Belan, B. D.; Granberg, I. G.; Arshinov, M. Y.; Athier, G.; Boumard, F.; Cousin, J.; Ciais, P.

2006-12-01

In-situ airborne measurement of trace gases CO2, CO and O3 were performed during an intensive campaign over Central and Eastern Siberia, as part of the YAK-AEROSIB project. The campaign took place in April 11-14, 2006. At that time, the region was a weak source of CO2 (<1 gC m-2 d-1) but a number of fires occurred (http://maps.geog.umd.edu) south of the flight track, over north-eastern China. A total of 26 vertical profiles were collected from the ground level up to 7 km along a flight track of 5000 km between Novossibirsk and Yakutsk. The signature of local and more remote pollution sources was observed, associated with layers of elevated CO2 and CO concentrations, typically higher than 390 ppm and 250 ppb respectively. In most layers, a positive correlation between CO2 and CO is observed. The spatial extent of these layers can be tracked coherently on profiles up to 800 km apart. Layers are encountered above 3500 m, but they are more marked above 5000 m. This agrees well with a previously established climatology of ozone and water vapour layers in the troposphere from the MOZAIC programme. The representation of such layers in current chemistry transport is challenging, due to the model's limited vertical resolution and vertical mixing parameterization. The CO vertical distribution indicated a high variability near the surface (140-300 ppbv), more stable, but still variable concentrations between 1 and 4 km (120-200 ppbv) and surprisingly elevated CO values aloft, reaching up to 250 ppbv in the Eastern part of the flight track. High ozone values were occasionally found in the free troposphere (50-60 ppbv) with one intrusion of stratospheric air and one occurrence of active photochemistry in the Kemerovo area. Elsewhere, the lack of correlation between CO and ozone suggests the presence of aged air masses, without active photochemistry. Systematic back-trajectories calculated for each profile pointed out to zonal flow conditions, bringing pollution from Europe to

Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

NASA Technical Reports Server (NTRS)

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

2016-01-01

Fire history within the northern larch forests of Central Siberia was studied (65 + deg N). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRIs) were found to be 112 ± 49 years (based on fire scars) and 106 ± 36 years (based on fire scars and tree natality dates). FRI were increased with latitude increase and observed to be about 80 years at 64 deg N, about 200 years near the Arctic Circle and about 300 years nearby the northern range limit of larch stands (approximately 71 deg + N). Northward FRI increase correlated with incoming solar radiation (r = -0.95). Post Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase.

Genetic history of an archaic hominin group from Denisova Cave in Siberia

PubMed Central

Reich, David; Green, Richard E.; Kircher, Martin; Krause, Johannes; Patterson, Nick; Durand, Eric Y.; Viola, Bence; Briggs, Adrian W.; Stenzel, Udo; Johnson, Philip L. F.; Maricic, Tomislav; Good, Jeffrey M.; Marques-Bonet, Tomas; Alkan, Can; Fu, Qiaomei; Mallick, Swapan; Li, Heng; Meyer, Matthias; Eichler, Evan E.; Stoneking, Mark; Richards, Michael; Talamo, Sahra; Shunkov, Michael V.; Derevianko, Anatoli P.; Hublin, Jean-Jacques; Kelso, Janet; Slatkin, Montgomery; Pääbo, Svante

2015-01-01

Using DNA extracted from a finger bone found in Denisova Cave in southern Siberia, we have sequenced the genome of an archaic hominin to about 1.9-fold coverage. This individual is from a group that shares a common origin with Neanderthals. This population was not involved in the putative gene flow from Neanderthals into Eurasians; however, the data suggest that it contributed 4–6% of its genetic material to the genomes of present-day Melanesians. We designate this hominin population ‘Denisovans’ and suggest that it may have been widespread in Asia during the Late Pleistocene epoch. A tooth found in Denisova Cave carries a mitochondrial genome highly similar to that of the finger bone. This tooth shares no derived morphological features with Neanderthals or modern humans, further indicating that Denisovans have an evolutionary history distinct from Neanderthals and modern humans. PMID:21179161

Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

PubMed Central

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

2017-01-01

Fire history within the northern larch forests of Central Siberia was studied (65+°N). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRI) were found to be 112 ± 49 years (based on fire scars) and 106 ± 36 years (based on fire scars and tree natality dates). FRI were increased with latitude increase, and observed to be about 80 years at 64°N, about 200 years near the Arctic Circle, and about 300 years nearby the northern range limit of larch stands (~71°+N). Northward FRI increase correlated with incoming solar radiation (r = − 0.95). Post Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase. PMID:28966554

Landsat imagery evidences great recent land cover changes induced by wild fires in central Siberia*

NASA Astrophysics Data System (ADS)

Antamoshkina, O. A.; Trofimova, N. V.; Antamoshkin, O. A.

2016-04-01

The article discusses the methods of satellite image classification to determine general types of forest ecosystems, as well as the long-term monitoring of ecosystems changes using satellite imagery of medium spatial resolution and the daily data of space monitoring of active fires. The area of interest of this work is 100 km footprint of the Zotino Tall Tower Observatory (ZOTTO), located near the Zotino settlement, Krasnoyarsk region. The study area is located in the middle taiga subzone of Western Siberia, are presented by the left and right banks of the Yenisei river. For Landsat satellite imagery supervised classification by the maximum likelihood method was made using ground-based studies over the last fifteen years. The results are the identification of the 10 aggregated classes of land surface and composition of the study area thematic map. Operational satellite monitoring and analysis of spatial information about ecosystem in the 100-kilometer footprint of the ZOTTO tall tower allows to monitor the dynamics of forest disturbance by fire and logging over a long time period and to estimate changes in forest ecosystems of the study area. Data on the number and area of fires detected in the study region for the 2000-2014 received in the work. Calculations show that active fires have burned more than a quarter of the footprint area over the study period. Fires have a significant impact on the redistribution of classes of land surface. Area of all types of vegetation ecosystems declined dramatically under the influence of fires, whereas industrial logging does not impact seriously on it. The results obtained in our work indicate the highest occurrence of fires for lichen forest types within study region, probably due to their high natural fire danger, which is consistent with other studies. The least damage the fire caused to the wetland ecosystem due to high content of moisture and the presence of a large number of fire breaks in the form of open water.

Molecular & genetic characteristics of Mycobacterium tuberculosis strains circulating in the southern part of West Siberia

PubMed Central

Pasechnik, Oksana; Dymova, Maya Alexandrovna; Stasenko, Vladimir Leonidovich; Blokh, Aleksey Igorevich; Tatarintseva, Marina Petrovna; Kolesnikova, Lyubov Pavlovna; Filipenko, Maksim Leonidovich

2017-01-01

Background & objectives: A complicated epidemiological situation characterized by significantly high tuberculosis (TB) morbidity is observed in West Siberia. This study was aimed to investigate the genetic characteristics of Mycobacterium tuberculosis circulating in the southern part of West Siberia (in the Omsk region). Methods: From March 2013 to January 2015, 100 isolates of M. tuberculosis were obtained from patients with pulmonary TB living in the Omsk region. Drug susceptibility testing was performed on Lowenstein-Jensen medium (absolute concentration method). Genetic typing of isolates was carried out by variable number tandem repeats of mycobacterial interspersed repetitive units (MIRU-VNTR) typing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The genetic types and characteristics of cluster strains were determined using 15 MIRU-VNTR loci. Results: Thirty six VNTR types were found. Twenty six (26.0%) isolates had a unique profile, and the remaining 74 were grouped in 10 clusters containing from 2 to 23 isolates. The Beijing genotype was found in 72 isolates, 61 (85.0%) of which were part of five clusters that included two large clusters containing 23 isolates. Other genetic families, such as Latin-American Mediterranean (LAM, 11.0%), S family (2.0%) and Haarlem (4.0%), were also detected. The genetic family of 11 isolates could not be determined. Six different VNTR profiles were found in these non-classified isolates. Only 16 per cent of isolates were sensitive to anti-TB drugs. The katG315 (94.8%) and rpoB531 (92.2%) mutations were identified in 77 multidrug-resistant M. tuberculosis isolates. Interpretation & conclusions: This study showed that the M. tuberculosis population in the Omsk region was heterogeneous. The Beijing genotype predominated and was actively spreading. The findings obtained point to the need for the implementation of more effective preventive measures to stop the spread of drug-resistant M

Greenhouse gas aerosols and pollutants over Siberia: the YAK-AEROSIB French Russian Joint International Laboratory

NASA Astrophysics Data System (ADS)

Paris, Jean-Daniel; Belan, Boris D.; Ancellet, Gérard; Nédélec, Philippe; Arshinov, Mikhail Yu.; Pruvost, Arnaud; Berchet, Antoine; Arzoumanian, Emmanuel; Pison, Isabelle; Ciais, Philippe; Law, Kathy

2014-05-01

Despite the unique scientific value of better knowing atmospheric composition over Siberia, regional observations of the tropospheric composition over this region are still lacking. Large local anthropogenic emissions, strong ecosystem gas exchange across the vast forest expanse, and processes feeding back to global climate such as wetlands CH4 emissions, seabed hydrates destabilization and degrading permafrost make this region particularly crucial to investigate. We aim at addressing this need in the YAK-AEROSIB program by collecting high-precision in-situ measurements of the vertical distribution of CO2, CH4, CO, O3, black carbon and ultrafine particles distribution in the Siberian troposphere, as well as other parameters including aerosol lidar profiles, on a pan-Siberian aircraft transect. Campaigns are performed almost annually since 2006 until now on this regular route, while special campaigns are occasionnally arranged to sample the troposphere elsewere (e.g. Russian Arctic coast). We show the background tropospheric composition obtained from these surveys, the variability and the impact of large-scale transport of anthropogenic emissions from Europe and Asia, as well as the impact of biomass burning plumes both from local wildfires (2012) and from remote sources elsewhere in Asia. Long range transport of anthropogenic emissions is shown to have a discernible impact on O3 distribution, although its lower-tropospheric variability is largely driven by surface deposition. Regional sources and sinks drive the lower troposphere CO2 and CH4 concentrations. Recent efforts aim at better understanding the respective role of CH4 emission processes (including methanogenesis in wetlands and emissions by wildfires) in driving its large scale atmospheric variability over the region. Generally, the YAK AEROSIB provide unique observations over Siberia, documenting both direct impact of regional sources and aged air masses experiencing long range transport toward the high

Molecular Gas toward the Gemini OB1 Molecular Cloud Complex. II. CO Outflow Candidates with Possible WISE Associations

NASA Astrophysics Data System (ADS)

Li, Yingjie; Li, Fa-Cheng; Xu, Ye; Wang, Chen; Du, Xin-Yu; Yang, Wenjin; Yang, Ji

2018-03-01

We present a large-scale survey of CO outflows in the Gem OB1 molecular cloud complex and its surroundings, using the Purple Mountain Observatory Delingha 13.7 m telescope. A total of 198 outflow candidates were identified over a large area (∼58.5 square degrees), of which 193 are newly detected. Approximately 68% (134/198) are associated with the Gem OB1 molecular cloud complex, including clouds GGMC 1, GGMC 2, BFS 52, GGMC 3, and GGMC 4. Other regions studied are: the Local arm (Local Lynds, West Front), Swallow, Horn, and Remote cloud. Outflow candidates in GGMC 1, BFS 52, and Swallow are mainly located at ring-like or filamentary structures. To avoid excessive uncertainty in distant regions (≳3.8 kpc), we only estimated the physical parameters for clouds in the Gem OB1 molecular cloud complex and in the Local arm. In those clouds, the total kinetic energy and the energy injection rate of the identified outflow candidates are ≲1% and ≲3% of the turbulent energy and the turbulent dissipation rate of each cloud, indicating that the identified outflow candidates cannot provide enough energy to balance turbulence of their host cloud at the scale of the entire cloud (several to dozens of parsecs). The gravitational binding energy of each cloud is ≳135 times the total kinetic energy of the identified outflow candidates within the corresponding cloud, indicating that the identified outflow candidates cannot cause major disruptions to the integrity of their host cloud at the scale of the entire cloud.

Direct observations of reactive atmospheric gases at ZOTTO station in the middle of Siberia as a base for large-scale modeling of atmospheric chemistry over Northern Eurasia

NASA Astrophysics Data System (ADS)

Skorokhod, Andrey; Belikov, Igor; Shtabkin, Yury; Moiseenko, Konstantin; Pankratova, Natalia; Vasileva, Anastasia; Rakitin, Vadim; Heimann, Martin

2015-04-01

Direct observations of atmospheric air composition are very important for a comprehensive understanding of atmospheric chemistry over Northern Eurasia and its variability and trends driven by abrupt climatic and ecosystem changes and anthropogenic pressure. Atmospheric air composition (including greenhouse gases and aerosols), its trends and variability is still insufficiently known for most of the nearly uninhabited areas of Northern Eurasia. This limits the accuracy of both global and regional models, which simulate climatological and ecosystem changes in this highly important region. From that point of view, the Zotino Tall Tower Observatory (ZOTTO) in the middle of Siberia (near 60N, 90E), launched in 2006 and governed by a scientific international consortium plays an important role providing unique information about concentrations of greenhouse and reactive trace gases, as well as aerosols. Simulations of surface concentrations of O3, NOx and CO performed by global chemical-transport model GEOS-Chem using up-to-date anthropogenic and biogenic emissions databases show very good agreement with values observed at ZOTTO in 2007-2012. Observed concentration of ozone has a pronounced seasonal variation with a clear peak in spring (40-45 ppbv in average and up to 80 ppbv in extreme cases) and minimum in winter. Average ozone level is about 20 ppbv that corresponds to the background conditions. Enhanced concentration in March-July is due to increased stratospheric-tropospheric exchange. In autumn and winter distribution of ozone is close to uniform. NOx concentration does not exceed 1 ppb that is typical for background areas but may vary by order and some more in few hours. Higher surface NOx(=NO+NO2) concentrations during day time generally correspond to higher ozone when NO/NO2 ratio indicates on clean or slightly polluted conditions. CO surface concentration has a vivid seasonal course and varies from about 100 ppb in summer till 150 ppb in winter. But during

Cloud Structure of Galactic OB Cluster-forming Regions from Combining Ground- and Space-based Bolometric Observations

NASA Astrophysics Data System (ADS)

Lin, Yuxin; Liu, Hauyu Baobab; Li, Di; Zhang, Zhi-Yu; Ginsburg, Adam; Pineda, Jaime E.; Qian, Lei; Galván-Madrid, Roberto; McLeod, Anna Faye; Rosolowsky, Erik; Dale, James E.; Immer, Katharina; Koch, Eric; Longmore, Steve; Walker, Daniel; Testi, Leonardo

2016-09-01

We have developed an iterative procedure to systematically combine the millimeter and submillimeter images of OB cluster-forming molecular clouds, which were taken by ground-based (CSO, JCMT, APEX, and IRAM-30 m) and space telescopes (Herschel and Planck). For the seven luminous (L\\gt {10}6 L ⊙) Galactic OB cluster-forming molecular clouds selected for our analyses, namely W49A, W43-Main, W43-South, W33, G10.6-0.4, G10.2-0.3, and G10.3-0.1, we have performed single-component, modified blackbody fits to each pixel of the combined (sub)millimeter images, and the Herschel PACS and SPIRE images at shorter wavelengths. The ˜10″ resolution dust column density and temperature maps of these sources revealed dramatically different morphologies, indicating very different modes of OB cluster-formation, or parent molecular cloud structures in different evolutionary stages. The molecular clouds W49A, W33, and G10.6-0.4 show centrally concentrated massive molecular clumps that are connected with approximately radially orientated molecular gas filaments. The W43-Main and W43-South molecular cloud complexes, which are located at the intersection of the Galactic near 3 kpc (or Scutum) arm and the Galactic bar, show a widely scattered distribution of dense molecular clumps/cores over the observed ˜10 pc spatial scale. The relatively evolved sources G10.2-0.3 and G10.3-0.1 appear to be affected by stellar feedback, and show a complicated cloud morphology embedded with abundant dense molecular clumps/cores. We find that with the high angular resolution we achieved, our visual classification of cloud morphology can be linked to the systematically derived statistical quantities (I.e., the enclosed mass profile, the column density probability distribution function (N-PDF), the two-point correlation function of column density, and the probability distribution function of clump/core separations). In particular, the massive molecular gas clumps located at the center of G10.6-0.4 and

Hydrodynamics Offshore of the North Beach of Indian River Inlet, DE

NASA Astrophysics Data System (ADS)

DiCosmo, N. R.; Puleo, J. A.

2014-12-01

The Indian River Inlet (IRI) on the east coast of Delaware, USA connects the Atlantic Ocean to the Indian River and Rehoboth Bays. Long-term and large-scale net alongshore sediment transport along this portion of coastline is from south to north. The north beach of IRI suffers from severe erosion due to interruption of the alongshore transport and current variability near the inlet. The magnitude of such erosion has increased over the past decade and questions have arisen as to the cause. The goal of this study is to quantify currents and wave patterns and estimate sediment transport rates at the north beach and near the inlet in an effort to determine the causes of persistent erosion. Data were obtained from October 2013 to March 2014 in the form of 3 separate 28-day deployments. Each deployment consisted of 4 proposed deployment sites. Data at each site were collected using a bottom mounted Nortek Aquadopp Acoustic Doppler Current Profiler (ADCP) and 2 Campbell Scientific Optical Backscatter Sensors (OBS). Currents and OBS data were sampled every 120 s. Waves were sampled for approximately 17 minutes at the beginning of every hour. Data analysis from the deployments indicates the presence of several interesting trends in currents that can be linked to the persistent erosion. Current data are filtered to quantify typical current speed and direction for a tidal cycle (peak flood to peak flood) at each deployment site. The typical currents off of the north beach and up to 800 m north of the north jetty are mostly directed southward over the entire tidal cycle. This consistent southward flow implies: 1) there is no flow reversal based on tide, contrary to what might be expected at an inlet adjacent beach, 2) the typical current direction is opposite of the expectations for the known long-term large-scale net alongshore transport and 3) the consistency of this atypical current may be responsible for transporting sediment southward and away from the north beach

New stands of species of the Paramecium aurelia complex (Ciliophora, Protista) in Russia (Siberia, Kamchatka).

PubMed

Przyboś, Ewa; Rautian, Maria; Surmacz, Marta; Bieliavskaya, Alexandra

2013-01-01

New stands of P. primaurelia, P. biaurelia, and P. dodecaurelia were found in Russia. P. primaurelia was recorded in Tulun (Siberia, Irkutsk region) and in three stands situated on the Kamchatka peninsula: in Lake Chalaktyrskoye, in the Valley of Geysers, and Petropavlovsk Kamchatski. P. biaurelia was also found in Tulun and in two stands in the vicinity of Lake Baikal and the Buriatia region. P. dodecaurelia was recorded in Cheboksary in European Russia and in other stands situated in Asian Russia: Novosibirsk, the vicinity of Lake Baikal, Buriatia, Kamchatka (Petropavlovsk Kamchatski, Lake Chalaktyrskoye, and Nalychevo). These data extend the ranges of species of the P. aurelia complex in Russia, however, this large territory remains understudied.

Variable millimetre radiation from the colliding-wind binary Cygnus OB2 #8A

NASA Astrophysics Data System (ADS)

Blomme, R.; Fenech, D. M.; Prinja, R. K.; Pittard, J. M.; Morford, J. C.

2017-12-01

Context. Massive binaries have stellar winds that collide. In the colliding-wind region, various physically interesting processes occur, leading to enhanced X-ray emission, non-thermal radio emission, as well as non-thermal X-rays and gamma-rays. Non-thermal radio emission (due to synchrotron radiation) has so far been observed at centimetre wavelengths. At millimetre wavelengths, the stellar winds and the colliding-wind region emit more thermal free-free radiation, and it is expected that any non-thermal contribution will be difficult or impossible to detect. Aims: We aim to determine if the material in the colliding-wind region contributes substantially to the observed millimetre fluxes of a colliding-wind binary. We also try to distinguish the synchrotron emission from the free-free emission. Methods: We monitored the massive binary Cyg OB2 #8A at 3 mm with the NOrthern Extended Millimeter Array (NOEMA) interferometer of the Institut de Radioastronomie Millimétrique (IRAM). The data were collected in 14 separate observing runs (in 2014 and 2016), and provide good coverage of the orbital period. Results: The observed millimetre fluxes range between 1.1 and 2.3 mJy, and show phase-locked variability, clearly indicating that a large part of the emission is due to the colliding-wind region. A simple synchrotron model gives fluxes with the correct order of magnitude, but with a maximum that is phase-shifted with respect to the observations. Qualitatively this phase shift can be explained by our neglect of orbital motion on the shape of the colliding-wind region. A model using only free-free emission results in only a slightly worse explanation of the observations. Additionally, on the map of our observations we also detect the O6.5 III star Cyg OB2 #8B, for which we determine a 3 mm flux of 0.21 ± 0.033 mJy. Conclusions: The question of whether synchrotron radiation or free-free emission dominates the millimetre fluxes of Cyg OB2 #8A remains open. More detailed

Current Soviet exploration plays: Success and potential

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

Grace, J.D.

1991-03-01

Soviet hydrocarbon exploration in the 1980s took four distinct directions. First was extension exploration and the search for smaller new fields in discrete traps in traditional producing regions, such as the Apsheron Peninsula, North Caucasus, and Volga-Urals. This strategy produced a large number of small discoveries close to established infrastructure. Second was new field exploration in West Siberia in the stratigraphically complex Jurassic and the lower Neocomian sections. Third was expansion of the prolific gas plays in northern West Siberia. Exploratory success in West Siberia has created a backlog of several hundred discoveries awaiting full delineation and development. Most ofmore » these fields are distant from the established oil production center in the Middle Ob region and, therefore, may remain in inventory. Fourth was initial tests of new exploration frontiers, most important, the Paleozoic and Mesozoic plays of the Barents and Kara seas and the subsalt plays of the North Caspian basin. While these plays have yielded very important discoveries, significant technological barriers impede their development. The outlook for Soviet oil exploration in the 1990s is for significant opportunities for discovery of large volumes of oil, but at radically increasing exploration and production costs. In established regions, these costs arise from small field sizes and low well productivities. In frontier regions, exploitation of new fields will require technology not currently available in the USSR. The outlook for gas exploration continues to be very bright, as the onshore northern West Siberia is not fully explored and initial results from the Barents and Kara seas promise more very large gas discoveries.« less

The Revised OB-1 Method for Metal-Water Systems

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

Westfall, Robert Michael; Wright, Richard Q

The OB-1 method for the calculation of the minimum critical mass (mcm) of fissile actinides in metal/water systems was described in a 2008 Nuclear Science and Engineering (NS&E) article. The purpose of the present work is to update and expand the application of this method with current nuclear data, including data uncertainties. The mcm and the hypothetical fissile metal density ({rho}{sub F}) in grams of metal/liter are obtained by a fit to values predicted with transport calculations. The input parameters required are thermal values for fission and absorption cross sections and nubar. A factor of ({radical}{pi})/2 is used to convertmore » to Maxwellian averaged values. The uncertainties for the fission and capture cross sections and the estimated nubar uncertainties are used to determine the uncertainties in the mcm, either in percent or grams.« less

Low energy gamma ray emission from the Cygnus OB2 association

NASA Technical Reports Server (NTRS)

Chen, Wan; White, Richard L.

1992-01-01

According to our newly developed model of gamma-ray emission from chaotic early-type stellar winds, we predict the combined gamma-ray flux from the circumstellar winds of many very luminous early-type stars in the Cyg OB2 association can be detectable by the Energetic Gamma Ray Experiment Telescope (EGRET) (and maybe also by OSSE) on CGRO. Due to different radiation mechanisms, the gamma-ray spectrum from stellar winds can be quite different from that of CYG X-3; this spectral difference and the time-variation of Cyg X-3 flux will help to distinguish the gamma-ray components from different sources in this small region, which is spatially unresolvable by CGRO.

[Features of the structure and parameters of the intra-alveolar septa in residents of Western Siberia].

PubMed

Shishkin, G S; Ustiuzhaninova, N V

1998-01-01

In inhabitants of Novosibirsk and Moscow district intraalveolar septum, the basic functional element of the lung consists of interstitial connective tissue and capillar network, limited with basement membranes, on which cells of epithelial lining are placed. There are no principal differences in septal structure between individuals from both regions. The majority of morphometric parameters are statistically similar, although certain peculiarities were noted in human subjects from Siberia, the most important of which is that air-blood barrier in them is 33% thinner than those in inhabitants of Moscow district. Majority of capillaries possess the air-blood barrier from both sides. This increases diffous capacity of the lungs and blood oxygenation level.

Investigating the prehistory of Tungusic peoples of Siberia and the Amur-Ussuri region with complete mtDNA genome sequences and Y-chromosomal markers.

PubMed

Duggan, Ana T; Whitten, Mark; Wiebe, Victor; Crawford, Michael; Butthof, Anne; Spitsyn, Victor; Makarov, Sergey; Novgorodov, Innokentiy; Osakovsky, Vladimir; Pakendorf, Brigitte

2013-01-01

Evenks and Evens, Tungusic-speaking reindeer herders and hunter-gatherers, are spread over a wide area of northern Asia, whereas their linguistic relatives the Udegey, sedentary fishermen and hunter-gatherers, are settled to the south of the lower Amur River. The prehistory and relationships of these Tungusic peoples are as yet poorly investigated, especially with respect to their interactions with neighbouring populations. In this study, we analyse over 500 complete mtDNA genome sequences from nine different Evenk and even subgroups as well as their geographic neighbours from Siberia and their linguistic relatives the Udegey from the Amur-Ussuri region in order to investigate the prehistory of the Tungusic populations. These data are supplemented with analyses of Y-chromosomal haplogroups and STR haplotypes in the Evenks, Evens, and neighbouring Siberian populations. We demonstrate that whereas the North Tungusic Evenks and Evens show evidence of shared ancestry both in the maternal and in the paternal line, this signal has been attenuated by genetic drift and differential gene flow with neighbouring populations, with isolation by distance further shaping the maternal genepool of the Evens. The Udegey, in contrast, appear quite divergent from their linguistic relatives in the maternal line, with a mtDNA haplogroup composition characteristic of populations of the Amur-Ussuri region. Nevertheless, they show affinities with the Evenks, indicating that they might be the result of admixture between local Amur-Ussuri populations and Tungusic populations from the north.

Food and water security issues in Russia III: food- and waterborne diseases in the Russian Arctic, Siberia and the Far East, 2000–2011

PubMed Central

Dudarev, Alexey A.; Dorofeyev, Vitaliy M.; Dushkina, Eugenia V.; Alloyarov, Pavel R.; Chupakhin, Valery S.; Sladkova, Yuliya N.; Kolesnikova, Tatjana A.; Fridman, Kirill B.; Nilsson, Lena Maria; Evengard, Birgitta

2013-01-01

Background The food- and waterborne disease situation in Russia requires special attention. Poor quality of centralized water supplies and sewage systems, biological and chemical contamination of drinking water, as well as contamination of food products, promote widespread infectious diseases, significantly exceeding nationwide rates in the population living in the two-thirds of Russian northern territories. Objectives The general aim was to assess the levels of food- and waterborne diseases in selected regions of Russian Arctic, Siberia and the Far East (for the period 2000–2011), and to compare disease levels among regions and with national levels in Russia. Study design and methods This study is the first comparative assessment of the morbidity in these fields of the population of 18 selected regions of Russian Arctic, Siberia and the Far East, using official statistical sources. The incidences of infectious and parasitic food- and waterborne diseases among the general population (including indigenous peoples) have been analyzed in selected regions (per 100,000 of population, averaged for 2000–2011). Results Among compulsory registered infectious and parasitic diseases, there were high rates and widespread incidences in selected regions of shigellosis, yersiniosis, hepatitis A, tularaemia, giardiasis, enterobiasis, ascariasis, diphyllobothriasis, opistorchiasis, echinococcosis and trichinellosis. Conclusion Incidences of infectious and parasitic food- and waterborne diseases in the general population of selected regions of the Russian Arctic, Siberia and the Far East (2000–2011) are alarmingly high. Parallel solutions must be on the agenda, including improvement of sanitary conditions of cities and settlements in the regions, modernization of the water supply and of the sewage system. Provision and monitoring of the quality of the drinking water, a reform of the general healthcare system and the epidemiological surveillance (including gender

Energy and Resource-Saving Sources of Energy in Small Power Engineering of Siberia

NASA Astrophysics Data System (ADS)

Baranova, Marina

2017-11-01

The sustainable development of distant areas of Siberia is associated with the structures of energy demand and supply, the implementation and promotion of the process of environmentally safe restructuring of the energy supply system. It has been established that suspension coal fuels derived from brown coal, coal mining, coal processing wastes can be used as fuel. The results of experimental and industrial boilers on suspension water coal fuel are presented. The designs of vortex combustion chambers of various powers are developed and tested. The possibility of using coal-enrichment wastes and substandard coals for the production of manure-coal fuel briquettes was studied. It is shown that the strength and thermal power characteristics of briquettes depend on the moisture content and degree of metamorphism of the raw materials. The most effective percentage of the solid phase and manure, as a binder, was determined.

Earth Obsersation taken by the Expedition 11 crew

NASA Image and Video Library

2005-05-24

ISS011-E-09913 (24 May 2005) --- Irkutsk, Siberia, Russian Federation is featured in this image photographed by an Expedition 11 crewmember on the International Space Station. Located approximately 55 kilometers (34 miles) to the northwest of Lake Baikal, Irkutsk is also the chief city of Irkutsk Oblast (equating to a province) in Siberia. The city is located on the Angara River. The central downtown area of the city is depicted in this photograph, as well as the Akademgorodok district around the State University (left of image along the southern bank of the Angara River). The oblique (non-vertical) look angle of this image imparts a three dimension perspective to the scene that accentuates the blockiness of Soviet-era building projects to the east of the downtown area. The Irkutsk Dam (center), built for the generation of hydroelectric power, dramatically widened the river and drowned several stream outlet channels along the north and south banks. The Angara River is the only outlet from Lake Baikal to the southeast, and impoundment of water behind the dam has raised the lake level by 6 meters (20 ft).

[Soil functioning in foci of Siberian moth population outbreaks in the southern taiga subzone of Central Siberia].

PubMed

Krasnoshchekov, Iu N; Beskorovaĭnaia, I N

2008-01-01

The results of experimental studies on the contribution of zoogenic debris to transformation of soil properties in the southern taiga subzone of Central Siberia are analyzed. They show that water-soluble carbon outflow from the forest litter increases by 21-26% upon a Siberian moth invasion, with this value decreasing to 14% one year later. The burning of forest in an area completely defoliated by the pest leads to changes in the stock, fractional composition, actual acidity, and ash element contents of the litter. The litter-dwelling invertebrate assemblage is almost completely destroyed by fire and begins to recover only after two years.

The Sredne-Amursky basin: A migrating cretaceous depocenter for the Amur river, eastern Siberia

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

Light, M.; Maslanyj, M.; Davidson, K.

1993-09-01

Recently acquired seismic, well, and regional geological data imply favorable conditions for the accumulation of oil and gas in the 20,000 km[sup 2] Sredne-Amursky basin. Major graben and northeast-trending sinistral wrench-fault systems are recognized in the basin. Lower and Upper Cretaceous sediments are up to 9000 and 3000 m thick, respectively. Paleogeographic reconstructions imply that during the Late Triassic-Early Cretaceous the Sredne-Amursky basin was part of a narrow marine embayment (back-arc basin), which was open to the north. During the Cretaceous, the region was part of a foreland basin complicated by strike-slip, which produced subsidence related to transtension during obliquemore » collision of the Sikhote-Alin arc with Eurasian margin. Contemporaneous uplift also related to this collision migrated from south to north and may have sourced northward-directed deltas and alluvial fans, which fed northward into the closing back-arc basin between 130 and 85 Ma. The progradational clastic succession of the Berriasian-Albian and the Late Cretaceous fluvial, brackish water and paralic sediments within the basin may be analogous to the highly productive late Tertiary clastics of the Amur River delta in the northeast Sakhalin basin. Cretaceous-Tertiary lacustrine-deltaic sapropelic shales provide significant source and seal potential and potential reservoirs occur in the Cretaceous and Tertiary. Structural plays were developed during Cretaceous rifting and subsequent strike-slip deformation. If the full hydrocarbon potential of the Sredne-Amursky basin is to be realized, the regional appraisal suggests that exploration should be focused toward the identification of plays related to prograding Cretaceous deltaic depositional systems.« less

Larch Forests of Middle Siberia: Long-Term Trends in Fire Return Intervals

NASA Technical Reports Server (NTRS)

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

2016-01-01

Fire history within the northern larch forests of Central Siberia was studied (65+degN). Fires within this area are predominantly caused by lightning strikes rather than human activity. Mean fire return intervals (FRIs) were found to be 112 +/- 49 years (based on firescars) and 106 +/- 36 years (based on firescars and tree natality dates). FRIs were increased with latitude increase and observed to be about 80 years at 64N, about 200 years near the Arctic Circle and about 300 years nearby the northern range limit of larch stands (approx.71+degN). Northward FRIs increase correlated with incoming solar radiation (r = -0.95). Post- Little Ice Age (LIA) warming (after 1850) caused approximately a doubling of fire events (in comparison with a similar period during LIA). The data obtained support a hypothesis of climate-induced fire frequency increase. Keywords Fire ecology Fire history Fire frequency Siberian wildfires Larch forests Climate change

New Low-mass Stars in the 25 Orionis Stellar Group and Orion OB1a Sub-association from SDSS-III/BOSS Spectroscopy

NASA Astrophysics Data System (ADS)

Suárez, Genaro; Downes, Juan José; Román-Zúñiga, Carlos; Covey, Kevin R.; Tapia, Mauricio; Hernández, Jesús; Petr-Gotzens, Monika G.; Stassun, Keivan G.; Briceño, César

2017-07-01

The Orion OB1a sub-association is a rich low-mass star (LMS) region. Previous spectroscopic studies have confirmed 160 LMSs in the 25 Orionis stellar group (25 Ori), which is the most prominent overdensity of Orion OB1a. Nonetheless, the current census of the 25 Ori members is estimated to be lower than 50% complete, leaving a large number of members to be still confirmed. We retrieved 172 low-resolution stellar spectra in Orion OB1a observed as ancillary science in the SDSS-III/BOSS survey, for which we classified their spectral types and determined physical parameters. To determine memberships, we analyzed the {{{H}}}α emission, Li I λ6708 absorption, and Na I λλ8183, 8195 absorption as youth indicators in stars classified as M type. We report 50 new LMSs spread across the 25 Orionis, ASCC 18, and ASCC 20 stellar groups with spectral types from M0 to M6, corresponding to a mass range of 0.10≤slant m/{M}⊙ ≤slant 0.58. This represents an increase of 50% in the number of known LMSs in the area and a net increase of 20% in the number of 25 Ori members in this mass range. Using parallax values from the Gaia DR1 catalog, we estimated the distances to these three stellar groups and found that they are all co-distant, at 338 ± 66 pc. We analyzed the spectral energy distributions of these LMSs and classified their disks into evolutionary classes. Using H-R diagrams, we found a suggestion that 25 Ori could be slightly older than the other two observed groups in Orion OB1a.

Detrital zircon geochronology of the Adams Argillite and Nation River Formation, east-central Alaska, U.S.A

USGS Publications Warehouse

Gehrels, G.E.; Johnsson, M.J.; Howell, D.G.

1999-01-01

The Cambrian Adams Argillite and the Devonian Nation River Formation are two sandstone-bearing units within a remarkably complete Paleozoic stratigraphic section in east-central Alaska. These strata, now foreshortened and fault-bounded, were originally contiguous with miogeoclinal strata to the east that formed as a passive-margin sequence along the northwestern margin of the North American continent. Seventy-five detrital zircon grains from the Adams Argillite and the Nation River Formation were analyzed in an effort to provide constraints on the original sources of the grains, and to generate a detrital zircon reference for miogeoclinal strata in the northern Cordillera. Thirty-five single zircon grains from a quartzite in the Adams Argillite yield dominant age clusters of 1047-1094 (n = 6), 1801-1868 (n = 10), and 2564-2687 (n = 5) Ma. Forty zircons extracted from a sandstone in the Nation River Formation yield clusters primarily of 424-434 (n = 6), 1815-1838 (n = 6), 1874-1921 (n = 7), and 2653-2771 (n = 4) Ma. The Early Proterozoic and Archean grains in both units probably originated in basement rocks in a broad region of the Canadian Shield. In contrast, the original igneous sources for mid-Protcrozoic grains in the Adams Argillite and ??? 430 Ma grains in the Nation River Formation are more difficult to identify. Possible original sources for the mid-Proterozoic grains include: (1) the Grenville Province of eastern Laurentia, (2) the Pearya terrane along the Arctic margin, and (3) mid-Proterozoic igneous rocks that may have been widespread along or outboard of the Cordilleran margin. The ??? 430 Ma grains may have originated in: (1) arc-type sources along the Cordilleran margin, (2) the Caledonian orogen, or (3) a landmass, such as Pearya, Siberia, or crustal fragments now in northern Asia, that resided outboard of the Innuitian orogen during mid-Paleozoic time. Copyright ?? 1999, SEPM (Society for Sedimentary Geology).

Perspectives on Fire Research Collaboration in Siberia: What Have We Learned; Why Does It Matter; and Where Do We Go from Here?

NASA Astrophysics Data System (ADS)

Conard, S. G.

2010-12-01

My first experience of the vast taiga forests of Russia, and my first chance to meet and work with Russian fire researchers, was at a 1993 conference and field experiment planned jointly by Johann G. Goldammer from Germany and Valentin V. Furyaev from Russia. This meeting was the beginning of a long and fruitful collaboration among US, Canadian, and Russian fire scientists. We all became increasingly aware of the global signifiance of the circumpolar boreal zone, and of the need for better information on the extent and effects of boreal fires. Wildfires are the dominant disturbance regime in the Russian boreal zone, burning 10 to 20 million hectares per year. These fires are a significant source of CO2 and other greenhouse gases and aerosols. Our research team published some of the first remote-sensing based estimates of the extent of fire in Russia and of the potential variability in emissions that could result from different burning conditions. Through a series of 20 prescribed burns we were able to mimic a wide range of burning conditions and obtain information on the impacts on soils, vegetation, and fuel consumption. Based on these experimental fires, we have modeled the effects of weather and fuels on fuel consumption and other factors, and related fire characteristics to emissions, carbon stocks, and soil and vegetation processes. For the past 10 years, we have focused on the ecosystem effects of fires of varying severity in the Scots pine and mixed larch forests of central Siberia, on improved remote-sensing based estimates of burned area and fire effects, and on relating fire weather indices to fire potential and fuel consumption. Logging is an increasingly important disturbance in Russia’s forests, and logged sites, with their high fuel loads seem particularly susceptible to fire. We are currently studying interactions between logging and fire, with an emphasis on the differences in fuel consumption, emissions, and carbon stocks when fires burn in

Alpine forest-tundra ecotone response to temperature change,Sayan Mountains, Siberia

NASA Technical Reports Server (NTRS)

Ranson, K Jon; Kharuk, Vyetcheslav I.

2007-01-01

Models of climate change predict shifts of vegetation zones. Tree response to climate trends is most likely observable in the forest-tundra ecotone, where temperature mainly limits tree growth. There is evidence of vegetation change on the northern treeline However, observations on alpine tree line response are controversial. In this NEESPI related study we show that during the past three decades in the forest-tundra ecotone of the Sayan Mountains, Siberia, there was an increase in forest stand crown closure, regeneration propagation into the alpine tundra, and transformation of prostrate Siberian pine and fir into arboreal forms. We found that these changes occurred since the mid 1980s, and strongly correlates with positive temperature (and to a lesser extent, precipitation) trends. Improving climate for forest growth( i.e., warmer temperatures and increased precipitation) provides competitive advantages to Siberian pine in the alpine forest-tundra ecotone, as well as in areas typically dominated by larch, where it has been found to be forming a secondary canopy layer. Substitution of deciduous conifer, larch, for evergreen conifers, decreases albedo and provides positive feedback for temperature increase.

Robotic Surgery Training in an OB/GYN Residency Program: A Survey Investigating the Optimal Training and Credentialing of OB/GYN Residents.

PubMed

Peterson, Shannon; Mayer, Allan; Nelson, Beth; Roland, Phillip

2015-08-01

Many community hospital gynecologic surgery training programs now include robotics.At St. Francis Hospital and Medical Center, we have integrated robotic surgical training since 2006. This study is designed to assess the success in training gynecology residents in robotic surgery. An anonymous web-based survey tool (www. survey monkey. com) was sent to all Ob/Gyn residency graduates from 2007-2010 (n = 17). From 2011-2014, we emailed three reevaluation questions to all 2007-2014 graduates (N = 32). Design Classification: II-3. The response rate was 95%, and 11 of 17 initial graduates (65%) indicated that they had received adequate robotic training. Currently, 24 of 32 (75%) graduates practice in hospitals with robotic availability. Twenty of the 32 graduates (63%) are using robotics in their surgical practices. Nine of these 20 graduates (45%) were fully credentialed following their residency. The other 11 graduates (55%)required further proctoring to obtain full robotic credentials. Robotic surgical training is a component of modern gynecologic surgical training. Postresidency robotic credentialing is a realistic graduation goal for residents who plan to practice gynecologic surgery.

The YAK-AEROSIB transcontinental aircraft campaigns: new insights on the transport of CO2, CO and O3 across Siberia

NASA Astrophysics Data System (ADS)

Paris, J.-D.; Ciais, P.; Nédélec, P.; Ramonet, M.; Belan, B. D.; Arshinov, M. Yu.; Golitsyn, G. S.; Granberg, I.; Stohl, A.; Cayez, G.; Athier, G.; Boumard, F.; Cousin, J.-M.

2008-09-01

Two airborne campaigns were carried out to measure the tropospheric concentrations and variability of CO2, CO and O3 over Siberia. In order to quantify the influence of remote and regional natural and anthropogenic sources, we analysed a total of 52 vertical profiles of these species collected in April and September 2006, every ~200 km and up to 7 km altitude. CO2 and CO concentrations were high in April 2006 (respectively 385-390 ppm CO2 and 160-200 ppb CO) compared to background values. CO concentrations up to 220 ppb were recorded above 3.5 km over eastern Siberia, with enhancements in 500-1000 m thick layers. The presence of CO enriched air masses resulted from a quick frontal uplift of a polluted air mass exposed to northern China anthropogenic emissions and to fire emissions in northern Mongolia. A dominant Asian origin for CO above 4 km (71.0%) contrasted with a dominant European origin below this altitude (70.9%) was deduced both from a transport model analysis, and from the contrasted ΔCO/ΔCO2 ratio vertical distribution. In September 2006, a significant O3 depletion (~ -30 ppb) was repeatedly observed in the boundary layer, as diagnosed from virtual potential temperature profiles and CO2 gradients, compared to the free troposphere aloft, suggestive of a strong O3 deposition over Siberian forests.

GIS-technologies application for calculation of potential soil loss of Marha River basin (Republic of Saha)

NASA Astrophysics Data System (ADS)

Shynbergenov, Y.; Maltsev, K.; Sihanova, N.

2018-01-01

In the article the presentation of estimation methods of potential soil loss in the conditions of Siberia with application of geographical information systems is resulted. For the reference area of the Marha river basin, which is a part of the Lena river catchment, there was created a specialized geographic information database of potential soil erosion, with scale of 1: 1,000,000. Digital elevation model “GMTED2010” and the hydroset layer corresponding to the scale of 1: 1,000,000 are taken to calculate the soil loss values. The formation of the geobase data is considered in detail being constructed on the basis of the multiplicative structure which reflects the main parameters of the relief (slope steepness, exposition, slope length, erosion potential of the relief), soil, climatic characteristics and modern types of land cover. At the quantitative level with sufficiently high degree of spatial detail results were obtained for calculating the potential erosion of soils. The average value of potential soil loss in the basin without taking into account the factor of land cover types, was 12.6 t/ha/yr. The calculations carried out, taking into account the types of land cover obtained from remote sensing data from outer space resulted in an appreciable reduction of the soil loss values (0.04 t/ha/yr.).

Nonthermal X-ray emission from winds of OB supergiants

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

Chen, W.; White, R.L.

1991-01-01

The mechanisms responsible for the hard X-ray emission of OB supergiants (OBSGs) are investigated theoretically, modifying the periodic-shock model of Lucy (1982). The physical processes discussed include (1) the particle acceleration (PA) mechanism and its effect on the structure of individual shocks, (2) the energy cutoff and spectral index of the relativistic electrons and ions, and (3) the efficiency of PA by shocks and its implications for the number densities of relativistic particles. The model is used to predict the spectrum and intensity of the dominant nonthermal X-ray emission source from OBSGs, and the results are shown to be inmore » good agreement with Einstein Observatory Solid-State Spectrometer observations of three OBSGs in Orion (Cassinelli and Swank, 1983). It is inferred that the surface magnetic fields of OBSGs are no greater than a few G, and that the PA rates are significantly lower than generally predicted for collisionless astrophysical shocks. 66 refs.« less

Irrigation and streamflow depletion in Columbia River basin above The Dalles, Oregon

USGS Publications Warehouse

Simons, Wilbur Douglas

1953-01-01

The Columbia River is the largest stream in western United States. Above The Dalles, Oregon, it drains an area of 237,000 square miles, of which 39,000 square miles is in Canada. This area is largely mountainous and lies between the Rocky Mountains and the Cascade Range. The Kootenai, Pend Oreille, and Snake Rivers are the principal tributaries. Precipitation varies from 7 inches near Kennewick, Wash. to over 100 inches in some of the mountainous regions. Most of the runoff occurs in the spring and summer months as a result of melting snow. Precipitation is generally light during the summer months, and irrigation is necessary for sustained crop production. Historical data indicate that irrigation in the Columbia River basin began prior to 1840 at the site of missions established near Walla Walla, Wash. and Lewiston, Idaho. During the next half century the increase in irrigated area was slow and by 1890 included only 506,000 acres. The period 1890 to 1910 was marked by phenomenal increase to a total of 2,276,000 acres in 1910. Since that time there has been more gradual addition to a total of 4,004,S00 acres of irrigated land in 1946 in the Columbia River basin above The Dalles, Oreg. Of this total 918,000 acres were located in the Columbia Basin above the mouth of the Snake River; 2,830,000 acres in the Snake River basin, and the balance, 256,000 acres below the mouth of the Snake River. Values of net consumptive use were determined or estimated for various tributary basins of the Columbia River basin and compared to available experimental data. These values were then used to compute the average depletion which could be directly attributed to irrigation. The yield of a drainage basin was considered to be the rum of the ob- served runoff and the estimated depletion. For purposes of comparison, the depletion was expressed both in terms of acre-feet and as a percentage of the yield of the basin. This percentage depletion varied from less than 1 percent for many

New OBS network deployment offshore Ireland

NASA Astrophysics Data System (ADS)

Le Pape, Florian; Bean, Chris; Craig, David; Jousset, Philippe; Horan, Clare; Hogg, Colin; Donne, Sarah; McCann, Hannah; Möllhoff, Martin; Kirk, Henning; Ploetz, Aline

2016-04-01

With the presence of the stormy NE Atlantic, Ireland is ideally located to investigate further our understanding of ocean generated microseisms and use noise correlation methods to develop seismic imaging in marine environments as well as time-lapse monitoring. In order to study the microseismic activity offshore Ireland, 10 Broad Band Ocean Bottom Seismographs (OBSs) units including hydrophones have been deployed in January 2016 across the shelf offshore Donegal and out into the Rockall Trough. This survey represents the first Broadband passive study in this part of the NE Atlantic. The instruments will be recovered in August 2016 providing 8 months worth of data to study microseisms but also the offshore seismic activity in the area. One of the main goal of the survey is to investigate the spatial and temporal distributions of dominant microseism source regions, close to the microseism sources. Additionally we will study the coupling of seismic and acoustic signals at the sea bed and its evolution in both the deep water and continental shelf areas. Furthermore, the survey also aims to investigate further the relationship between sea state conditions (e.g. wave height, period), seafloor pressure variations and seismic data recorded on both land and seafloor. Finally, the deployed OBS network is also the first ever attempt to closely monitor local offshore earthquakes in Ireland. Ireland seismicity although relatively low can reduce slope stability and poses the possibility of triggering large offshore landslides and local tsunamis.

Characterization of the role of copCD in copper uptake and the 'copper-switch' in Methylosinus trichosporium OB3b.

PubMed

Gu, Wenyu; Farhan Ul Haque, Muhammad; Semrau, Jeremy D

2017-05-01

Methanotrophs or methane-oxidizing bacteria exhibit a unique 'copper-switch' where expression of two forms of methane monooxygenase (MMO) is controlled by the availability of copper. In the absence of copper, a cytoplasmic or soluble methane monooxygenase (sMMO) is expressed. In the presence of copper, a membrane-bound or particulate methane monooxygenase (pMMO) is expressed. These two forms of MMO have very different properties, and elucidation of the basis of the copper-switch is of significant interest as methanotrophs are becoming increasingly popular for the valorization of methane. Recently, it was suggested via characterization of a mutant of Methylosinus trichosporium OB3b that expresses sMMO in the presence of copper (smmoC mutant) that the copper-switch may be based on copCD. These genes encode for a periplasmic copper-binding protein and an inner membrane protein, respectively, and are used by other bacteria for copper uptake. Specific knockouts of copCD in M. trichosporium OB3b wild type, however, show that these genes are not part of the copper-switch in methanotrophs, nor do they appear to be critical for copper uptake. Rather, it appears that the constitutive expression of sMMO in the smmoC mutant of M. trichosporium OB3b may be due to multiple lesions as smmoC was generated via random chemical mutagenesis. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Agrolandscape Research of Geosystems in the South of Central Siberia

NASA Astrophysics Data System (ADS)

Lysanova, G.; Soja, A. J.

2012-12-01

Minusinskaya basin, the area under research, is situated in the south of Central Siberia and is an agrarian region, which differs from another territories of Siberia. The territory provides for foodstuff not only its population but another regions as well. Nature-climate conditions favour the development of agriculture and cattle-breeding. Complex geographical study of rural lands, which is implemented by two approaches: a natural and industrial system block is necessary for rational use of agrolandscapes. Agrolandscapes are objects for rationalization of land management in agricultural regions. From our point of view application of a landscape map as a base for working out of agrolandscape map (Fig. 1a) and a map of agronatural potential of geosystems (Fig. 2), gives an opportunity to take stock of reserves of agricultural lands not only in quantitative but qualitative respects and also to determine the ways of optimal transformation of arable lands depending on nature conditions of regions and their development. Landscape maps that reflect differentiation of not only natural formations, changed by anthropogenious influence and also natural analogues, concern to a number of important tools of planning for optimal land use. The main principles of working out of typological landscape map of a medium scale aroused from targets and tasks of agrolandscape estimation of the territory [1]. The landscape map was worked out according to V.A. Nikolaev's methodology [2]: types of landscapes correlated with types of lands use, composition of cereals in rotation of crops, agro-techniques, crop capacity, climate indices, etc. Existing natural-agricultural systems are shown in the map. Their characteristics includes information about natural and agricultural blocks. Agronatural potential had been calculated by summarize estimations of its component parts. As a result of these calculations 30 arable agrolandscapes, marked out into the landscape map, were joined according to summ

Simulated long-term changes in river discharge and soil moisture due to global warming

USGS Publications Warehouse

Manabe, S.; Milly, P.C.D.; Wetherald, R.

2004-01-01

By use of a coupled ocean atmosphere-land model, this study explores the changes of water availability, as measured by river discharge and soil moisture, that could occur by the middle of the 21st century in response to combined increases of greenhouse gases and sulphate aerosols based upon the "IS92a" scenario. In addition, it presents the simulated change in water availability that might be realized in a few centuries in response to a quadrupling of CO2 concentration in the atmosphere. Averaging the results over extended periods, the radiatively forced changes, which are very similar between the two sets of experiments, were successfully extracted. The analysis indicates that the discharges from Arctic rivers such as the Mackenzie and Ob' increase by up to 20% (of the pre-Industrial Period level) by the middle of the 21st century and by up to 40% or more in a few centuries. In the tropics, the discharges from the Amazonas and Ganga-Brahmaputra rivers increase substantially. However, the percentage changes in runoff from other tropical and many mid-latitude rivers are smaller, with both positive and negative signs. For soil moisture, the results of this study indicate reductions during much of the year in many semiarid regions of the world, such as the southwestern region of North America, the northeastern region of China, the Mediterranean coast of Europe, and the grasslands of Australia and Africa. As a percentage, the reduction is particularly large during the dry season. From middle to high latitudes of the Northern Hemisphere, soil moisture decreases in summer but increases in winter.