28 research outputs found

    КЛИНИКО-БИОХИМИЧЕСКАЯ ХАРАКТЕРИСТИКА НЕДОНОШЕННЫХ НОВОРОЖДЕННЫХ С ЭКСТРЕМАЛЬНО НИЗКОЙ И ОЧЕНЬ НИЗКОЙ МАССОЙ ТЕЛА ПРИ РОЖДЕНИИ

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    The purpose of this work was to study the levels of neurotrophic factor nerve growth of the brain, the levels of vascular endothelial growth factor, the levels of neurospecific enolase and the activity of endothelin-1 in the serum of blood in preterm infants with extremely low birth weight in association with the state of the cerebral circulation, and morphologic changes in the brain. We examined 60 preterm infants, which were divided into two groups depending on weight at birth. In neonates with extremely low birth weight the dysfunction of mechanism of autoregulation in cerebral blood flow was characterized by a decrease in blood flow velocities in the anterior cerebral and in the basilar arteries, in association with low levels of trophic factors in serum to month of life and the developments of degenerative changes in the brain. In neonates with very low birth weight infants in the early neonatal period the vasospasm of cerebral vessels with the activity of neurotrophic factors to month of life gave way to the stabilization of the cerebral hemodynamics.Целью работы стало изучение сывороточного содержания нейротрофического фактора роста нервов головного мозга, васкулоэндотелиального фактора роста, сывороточной концентрации нейроспецифической енолазы и сывороточной активности эндотелина-1 у недоношенных новорожденных с экстремально низкой массой тела в ассоциации с состоянием мозгового кровообращения и морфоструктурными изменениями головного мозга. Обследовано 60 недоношенных новорожденных, которые были разделены на две группы в зависимости от массы тела при рождении. У новорожденных с экстремально низкой массой тела дисфункция механизма ауторегуляции мозгового кровотока в раннем неонатальном периоде характеризовалась снижением показателей скоростей кровотока в передней мозговой и базилярной артериях в ассоциации с низким сывороточным содержанием трофических факторов роста, что к 1 мес жизни обусловливало развитие дистрофических изменений головного мозга. У новорожденных с очень низкой массой тела в раннем неонатальном периоде вазоспазм церебральных сосудов в сочетании с активностью нейротрофических факторов роста к 1 мес жизни сменялся стабилизацией мозговой гемодинамики

    Data descriptor: a global multiproxy database for temperature reconstructions of the Common Era

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    Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high-and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python. (TABLE) Since the pioneering work of D'Arrigo and Jacoby1-3, as well as Mann et al. 4,5, temperature reconstructions of the Common Era have become a key component of climate assessments6-9. Such reconstructions depend strongly on the composition of the underlying network of climate proxies10, and it is therefore critical for the climate community to have access to a community-vetted, quality-controlled database of temperature-sensitive records stored in a self-describing format. The Past Global Changes (PAGES) 2k consortium, a self-organized, international group of experts, recently assembled such a database, and used it to reconstruct surface temperature over continental-scale regions11 (hereafter, ` PAGES2k-2013'). This data descriptor presents version 2.0.0 of the PAGES2k proxy temperature database (Data Citation 1). It augments the PAGES2k-2013 collection of terrestrial records with marine records assembled by the Ocean2k working group at centennial12 and annual13 time scales. In addition to these previously published data compilations, this version includes substantially more records, extensive new metadata, and validation. Furthermore, the selection criteria for records included in this version are applied more uniformly and transparently across regions, resulting in a more cohesive data product. This data descriptor describes the contents of the database, the criteria for inclusion, and quantifies the relation of each record with instrumental temperature. In addition, the paleotemperature time series are summarized as composites to highlight the most salient decadal-to centennial-scale behaviour of the dataset and check mutual consistency between paleoclimate archives. We provide extensive Matlab code to probe the database-processing, filtering and aggregating it in various ways to investigate temperature variability over the Common Era. The unique approach to data stewardship and code-sharing employed here is designed to enable an unprecedented scale of investigation of the temperature history of the Common Era, by the scientific community and citizen-scientists alike

    Strong changes in englacial temperatures despite insignificant changes in ice thickness at Dome du Gouter glacier (Mont Blanc area)

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    The response of very-high-elevation glaciated areas on Mont Blanc to climate change has been analysed using observations and numerical modelling over the last 2 decades. Unlike the changes at low elevations, we observe very low glacier thickness changes, of about - 2.6 m on average since 1993. The slight changes in horizontal ice flow velocities and submergence velocities suggest a decrease of about 10 % in ice flux and surface mass balance. This is due to less snow accumulation and is consistent with the precipitation decrease observed in meteorological data. Conversely, measurements performed in deep boreholes since 1994 reveal strong changes in englacial temperature reaching a 1.5 degrees C increase at a depth of 50 m. We conclude that at such very high elevations, current changes in climate do not lead to visible changes in glacier thickness but cause invisible changes within the glacier in terms of englacial temperatures. Our analysis from numerical modelling shows that glacier near-surface temperature warming is enhanced by increasing melt frequency at high elevations although the impact on surface mass balance is low. This results in a non-linear response of englacial temperature to currently rising air temperatures. In addition, borehole temperature inversion including a new dataset confirms previous findings of similar air temperature changes at high and low elevations in the Alps

    Технология ДНК-штрихкодирования в Беларуси: перспективы и востребованность

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    The DNA identification of rare and endangered plant species started in 2017 at the Republican DNA Bank. DNA barcoding is the best approach and tool to study flora and fauna and organize the obtained data in a special database. At present, the database contains barcodes (ITS2, rbcL, psbA-trnH) of 35 wild plant species growing in the territory of the Republic of Belarus. This is the first effort Belarus has made in compiling a Reference DNA Barcode Library to provide for the identification of rare and endangered plant species in the protected areas and biological collections
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