105 research outputs found
Phylogenetic Analysis of <i>Yersinia pestis</i> Strains of Medieval Biovar from Natural Plague Foci of the Russian Federation and Bordering Countries
Objective of the study is to conduct phylogenetic investigation of Yersinia pestis strains (medieval biovar) from plague foci of Russia and bordering countries, using SNP-analysis of the genome-wide sequences of these strains. Materials and methods. Carried out has been sequencing of 14 Y. pestis strains, medieval biovar, from 13 natural plague foci of Russia and neighboring states, as well as their comparison to 9 strains of the same biovar, contained in the NCBI GenBank database. Using software products - Wombac 2.0 and Bionumerics 7.1, revealed is the presence of 1875 core SNPs, on the basis of which a dendrogram of phylogenetic relations between medieval strains is constructed. Results and conclusions. In consequence of genome-wide SNP-analysis, it is established that Y. pestis strains, medieval biovar, from plague foci of Russia and bordering states are assigned to 2.MED1 phylogenetic line and fall under two major evolutionary branches, the first one of which includes strains from the Caucasus and Caspian-Sea regions, and the second one - from Central Asia and China. The data obtained can be used for the development of molecular-genetic methods for differentiation of Y. pestis strains, medieval biovar
Phenotypic and Molecular-Genetic Peculiarities of Yersinia pestis Strains from Trans-Baikal Steppe Plague Focus
The paper contains the data on the complex phenotypic and genotypic characteristics of
Yersinia pestisstrains isolated in Trans-Baikal steppe plague focus before and after the succession of the main carrier which took place in the 1960s. Based on the PCR-analysis and multilocus sequence typing of
glpD, melB, napA, rhaA, and
iclR genes, encoding differentially significant properties such as glycerin, melibiose, rhamnose fermentation, isocitrate lyase production, and denitrification activity, developed are the proofs of affiliation of the studied strains to the biovariant antiqua of the plague agent main subspecies. Multilocus VNTR-analysis by seven locuses of variable tandem repeats – ms01, ms04, ms06, ms07, ms46, ms62 – has been used to establish genetic relations between the strains. Thus on the basis of the results obtained, it is established that the strains of the plague agent, isolated in the Trans-Baikal steppe focus in various periods of its existence, form one common branch on the phylogenetic tree of
Y. pestis evolution
Updating of Intra-Specific <i>Yersinia pestis</i> Classification, Based on the Results of Whole-Genome Sequencing of the Strains from the Russian Federation and the Neighboring States
Carried out has been genome-wide sequencing of 20 Yersinia pestis strains from all 11 natural plague foci in Russia and some foci in the neighboring states. Phylogenetic analysis on the basis of 1918 core SNPs, identified in the genomes of these strains and 16 Y. pestis strains from NCBI GenBank, has revealed 5 clusters of closely related strains. Taking these clusters into account, up-dated has been subspecific classification of plague agent. New taxonomy has combined 5 subspecies: major (ssp. pestis ), Caucasian (ssp. caucasica ), ulegeisk (ssp. ulegeica ), and two novel ones - Central Asian (ssp. central asiatica ) and Angolan (ssp. angola ). Central Asian subspecie comprises evolutionally related strains, earlier classified as altaica and hissarica, as well as the strains from Talas high-mountain focus in Kirghizia and Uzbekistan, and microtus strains from China. Central asiatica is divided into three biovars - altai, hissar, and microtus. Set forward is a serviceable designation for the strains: 0.PE4a - for altai ones, 0.PE4h - for hissar, 0.PE4t - for talas, and 0.PE4m - for microtus, and also for ulegeica subspecie - 0.PE5
Особенности расчета двухкорпусной вакуум-выпарной кристаллизации
A technique for calculating a two-case vacuum-evaporating crystallization installation was considered. The first case of the installation it is used for concentrating the initial solution by its evaporation. The second case is used for evaporating crystallization. Thus, secondary steams of the evaporating device are used for crystallizer heating.Рассмотрена методика расчета двухкорпусной установки для вакуум-выпарной кристаллизации, при проведении которой в первом корпусе установки производится концентрирование исходного раствора путем его упаривания, а во втором корпусе осуществляется процесс выпарной кристаллизации
SOME FEATURES OF CURRENT TECHNOGENIC MOVEMENTS OF THE EARTH’S CRUST
We describe the history of studying the current crustal movements by various methods and discuss technogenic effects recorded at large water-reservoir zones and mineral deposits in Siberia. Initially, classical surveying techniques aimed to obtain high-accuracy ground-based measurements of height, tilt and direction. Modern geodesy techniques and methods for measuring absolute gravity are now available to investigate displacement, deformation, tilt and other phenomena taking place on the Earth’s surface. These methods are used to estimate kinematic parameters of the crust areas (e.g. rates of subsidence and horizontal movements) and to monitor fluid motions in mineral deposits. Such data are critical for ensuring a proper management of the mineral deposits. In this article, we analyse technogenic processes observed in the Ust Balyk oil-gas field, the Zapolyarny gas deposit, the water-reservoir zone at the Sayano-Shushenskaya hydroelectric power station (SSHPS) on the Yenisei river, and large open-pit mines in the Kuzbass basin. Our analysis is based on surface displacement rates estimated from the data collected in different periods of observations at large man-made facilities. In the study of the hydro technical objects, we estimated the displacement rates at 5.0 mm per year. In the northern areas of the West Siberian petroleum basin, subsidence rates amounted to 20–25 mm per year in the early 2000s. These estimates were supported by the high-accuracy gravity measurements showing an increase up to 6–7 microGal per year in the oil-gas field development areas. We assess a possibility of triggering effects related to weak seismicity due to a high stress accumulation rate (1 KPa per hour) in the SSHPS area. A connection between earth tides and catastrophic events, such as gas emissions in high amounts on mining sites, is discussed. Having analysed the surface monitoring records taken in South Primorye in September 2017, we conclude that underground nuclear explosions in North Korea in this period did not cause any significant displacement of the surface in this most southerly region of the Russian Far East territories
Evaluation of Effectiveness of Yersinia pestis Molecular Diagnostics in the Field Material from Sarydzhas Focus in Kyrgyzstan
Objective of the study is to assess the effectiveness of the methods for molecular diagnostics and identification of Yersinia pestis strains in the field material obtained from Sarydzhas high-mountain focus in Kyrgyz Republic. Materials and methods. Investigated were the samples of the field material, isolated in 2016 in Sarydzhas high-mountain plague focus, using conventional methods of laboratory diagnostics and PCR with hybridization-fluorescent and electrophoretic registration of results. Results and conclusions. It is demonstrated that in a number of cases molecular-genetic method has a higher resolution as compared to conventional methods of laboratory diagnostics of plague. It proves the necessity of wider usage of molecular-diagnostic methods in epizootiological monitoring of plague in natural foci in Kyrgyz Republic
Fast optical variability of SS 433
We study the optical variability of the peculiar Galactic source SS 433 using
the observations made with the Russian Turkish 1.5-m telescope (RTT150). A
simple technique which allows to obtain high-quality photometric measurements
with 0.3-1 s time resolution using ordinary CCD is described in detail. Using
the test observations of nonvariable stars, we show that the atmospheric
turbulence introduces no significant distortions into the measured light
curves. Therefore, the data obtained in this way are well suited for studying
the aperiodic variability of various objects.
The large amount of SS 433 optical light curve measurements obtained in this
way allowed us to obtain the power spectra of its flux variability with a
record sensitivity up to frequencies of ~0.5 Hz and to detect its break at
frequency =~2.4e-3 Hz. We suggest that this break in the power spectrum results
from the smoothing of the optical flux variability due to a finite size of the
emitting region. Based on our measurement of the break frequency in the power
spectrum, we estimated the size of the accretion-disk photosphere as 2e12 cm.
We show that the amplitude of the variability in SS 433 decreases sharply
during accretion-disk eclipses, but it does not disappear completely. This
suggests that the size of the variable optical emission source is comparable to
that of the normal star whose size is therefore R_O \approx 2e12 cm \approx 30
R_sun. The decrease in flux variability amplitude during eclipses suggests the
presence of a nonvariable optical emission component with a magnitude
m_R=~13.2.Comment: 12 pages, 11 figures. Accepted for publication in Astronomy Letters.
The original version in Russian is available at
http://hea.iki.rssi.ru/rtt150/ru/ss433_pazh10/pss433_fast.pd
Molecular-Genetic and Phenotypic Peculiarities of Plague Agent Strains Isolated in Vietnam
Objective of the study is to investigate phenotypic and molecular-genetic features and perform whole genome sequencing of Y. pestis strains isolated in Vietnam. Materials and methods. Studied were phenotypic and genotypic peculiarities of 20 plague agent strains isolated in different prefectures of Vietnam. Carried out was SNP-analysis of the strains, sequenced were genomes of 8 Y. pestis strains. Results and conclusions. Based on the results of studies of differential biochemical characteristics all the investigated strains were attributed to oriental biovar of the main subspecies of plague agent, which was confirmed by the presence of marker indel mutation – deletion of 93 bps in glpD gene. Investigated was also the plasmid composition of the strains. On the basis of the conducted genome sequencing and SNP-analysis appurtenance of 19 out of 20 strains under examination was determined. They belong to 1.ORI2v phylogenetic branch, relative to the strains isolated in Yunnan Province, China, which points to their common origin. Identified was a marker SNP and developed the method of SNP-typing for 1.ORI2v strains from Vietnam
Effect of Phytopreparations Based on Bioreactor-Grown Cell Biomass of Dioscorea Deltoidea, Tribulus Terrestris and Panax Japonicus on Carbohydrate and Lipid Metabolism in Type 2 Diabetes Mellitus
In the present study, we explored the therapeutic potential of bioreactor-grown cell cultures of the medicinal plant species Dioscorea deltoidea, Tribulus terrestris and Panax japonicus to treat carbohydrate metabolism disorders (CMDs) in laboratory rats. In the adrenaline model of hyperglycemia, aqueous suspensions of cell biomass pre-administered at a dose of 100 mg dry biomass/kg significantly reduced glucose level in animal blood 1–2.5 h (D. deltoidea and T. terrestris) or 1 h (P. japonicus) after adrenaline hydrochloride administration. In a streptozotocin-induced model of type 2 diabetes mellitus, the cell biomass of D. deltoidea and T. terrestris acted towards normalization of carbohydrate and lipid metabolism, as evidenced by a significant reduction of daily diuresis (by 39– 57%), blood-glucose level (by 46–51%), blood content in urine (by 78–80%) and total cholesterol (25– 36%) compared to animals without treatment. Bioactive secondary metabolites identified in the cell cultures and potentially responsible for their actions were deltoside, 25(S)-protodioscin and protodioscin in D. deltoidea; furostanol-type steroidal glycosides and quinic acid derivatives in T. terrestris; and ginsenosides and malonyl-ginsenosides in P. japonicus. These results evidenced for high potential of bioreactor-grown cell suspensions of these species for prevention and treatment of CMD, which requires further investigation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This.Funding: Bioreactor cultivation of plant cell suspensions and their biochemical analysis were financially supported by the Ministry of Science and Higher Education of Russian Federation through Megagrant project no. 075-15-2019-1882 and performed by using the equipment of the large-scale research facilities “Experimental biotechnological facility” and “All-Russian Collection of cell cultures of higher plants” of the IPPRAS (EBF IPPRAS and ARCCC HP IPPRAS). Hypoglycemic activity evaluation of the cell biomass was performed with the financial support of the Russian Science Foundation project no. 19-14-00387. The results of the hypoglycemic activity evaluation were obtained by using the equipment of the Center for Collective Use “Analytical Center of the Federal State Budgetary Educational Institution of Higher Education Saint Petersburg State Chemical Pharmaceutical University (SPCPU) of the Ministry of Health of Russia”, equipped with the financial support of the Ministry of Education and Science of Russia
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