321 research outputs found

    Student's metacompetences development in the information society context

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    The educational resource of volunteering in the information society is considered. The analysis of student’s metacompetencies which are developed in the process of volunteering is given. In the article metacompetencies describe the levels of student’s agency development, which determines the personal and professional formation of the future university alumnus. The relevance of pedagogical support for the student’s agency development in volunteering participating is given

    Social Programs of South Korean’s TNC in Sub-Saharan Africa

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    Доклад посвящен важному аспекту гуманитарного сотрудничества Республики Корея со странами Африки — проектам на Черном континенте южнокорейских ТНК. Источниковой базой исследования стали материалы официальных сайтов ТНК, а также СМИ. Автор приходит к выводу о том, что южнокорейские ТНК вносят серьезный вклад в инфраструктурное развитие стран Африки.The report is devoted to an important aspect of the humanitarian cooperation of the Republic of Korea with African countries — projects on the Black Continent of South Korean TNCs. The source base for the study was the materials of the official websites of TNCs, as well as the media. The author concludes that South Korean TNCs make a significant contribution to the infrastructure development of African countries

    Methyltrimethoxysilane-based elastic aerogels: effects of the supercritical medium on structure-sensitive properties

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    Effects caused by the type of solvent used for supercritical drying on the properties of methyltrimethoxysilane-based aerogels were studied. All of the aerogel samples studied were found to be hydrophobic and to efficiently adsorb nonpolar organic compounds

    Hygienic assessment of nutrition in a neurological hospital

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    The article provides a hygienic assessment of nutrition of patients with various spinal injuries who are undergoing rehabilitation in a neurological hospital. The results of the analysis are presented.В статье произведена гигиеническая оценка питания пациентов с различными спинальными травмами, находящихся на реабилитации в неврологическом стационаре. Представлены результаты анализ

    Topological Photonics

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    Topology is revolutionizing photonics, bringing with it new theoretical discoveries and a wealth of potential applications. This field was inspired by the discovery of topological insulators, in which interfacial electrons transport without dissipation even in the presence of impurities. Similarly, new optical mirrors of different wave-vector space topologies have been constructed to support new states of light propagating at their interfaces. These novel waveguides allow light to flow around large imperfections without back-reflection. The present review explains the underlying principles and highlights the major findings in photonic crystals, coupled resonators, metamaterials and quasicrystals.Comment: progress and review of an emerging field, 12 pages, 6 figures and 1 tabl

    RAD50 Is Required for Efficient Initiation of Resection and Recombinational Repair at Random, γ-Induced Double-Strand Break Ends

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    Resection of DNA double-strand break (DSB) ends is generally considered a critical determinant in pathways of DSB repair and genome stability. Unlike for enzymatically induced site-specific DSBs, little is known about processing of random “dirty-ended” DSBs created by DNA damaging agents such as ionizing radiation. Here we present a novel system for monitoring early events in the repair of random DSBs, based on our finding that single-strand tails generated by resection at the ends of large molecules in budding yeast decreases mobility during pulsed field gel electrophoresis (PFGE). We utilized this “PFGE-shift” to follow the fate of both ends of linear molecules generated by a single random DSB in circular chromosomes. Within 10 min after γ-irradiation of G2/M arrested WT cells, there is a near-synchronous PFGE-shift of the linearized circular molecules, corresponding to resection of a few hundred bases. Resection at the radiation-induced DSBs continues so that by the time of significant repair of DSBs at 1 hr there is about 1–2 kb resection per DSB end. The PFGE-shift is comparable in WT and recombination-defective rad52 and rad51 strains but somewhat delayed in exo1 mutants. However, in rad50 and mre11 null mutants the initiation and generation of resected ends at radiation-induced DSB ends is greatly reduced in G2/M. Thus, the Rad50/Mre11/Xrs2 complex is responsible for rapid processing of most damaged ends into substrates that subsequently undergo recombinational repair. A similar requirement was found for RAD50 in asynchronously growing cells. Among the few molecules exhibiting shift in the rad50 mutant, the residual resection is consistent with resection at only one of the DSB ends. Surprisingly, within 1 hr after irradiation, double-length linear molecules are detected in the WT and rad50, but not in rad52, strains that are likely due to crossovers that are largely resection- and RAD50-independent

    DNA Resection at Chromosome Breaks Promotes Genome Stability by Constraining Non-Allelic Homologous Recombination

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    DNA double-strand breaks impact genome stability by triggering many of the large-scale genome rearrangements associated with evolution and cancer. One of the first steps in repairing this damage is 5′→3′ resection beginning at the break site. Recently, tools have become available to study the consequences of not extensively resecting double-strand breaks. Here we examine the role of Sgs1- and Exo1-dependent resection on genome stability using a non-selective assay that we previously developed using diploid yeast. We find that Saccharomyces cerevisiae lacking Sgs1 and Exo1 retains a very efficient repair process that is highly mutagenic to genome structure. Specifically, 51% of cells lacking Sgs1 and Exo1 repair a double-strand break using repetitive sequences 12–48 kb distal from the initial break site, thereby generating a genome rearrangement. These Sgs1- and Exo1-independent rearrangements depend partially upon a Rad51-mediated homologous recombination pathway. Furthermore, without resection a robust cell cycle arrest is not activated, allowing a cell with a single double-strand break to divide before repair, potentially yielding multiple progeny each with a different rearrangement. This profusion of rearranged genomes suggests that cells tolerate any dangers associated with extensive resection to inhibit mutagenic pathways such as break-distal recombination. The activation of break-distal recipient repeats and amplification of broken chromosomes when resection is limited raise the possibility that genome regions that are difficult to resect may be hotspots for rearrangements. These results may also explain why mutations in resection machinery are associated with cancer

    Sgs1 and Exo1 Redundantly Inhibit Break-Induced Replication and De Novo Telomere Addition at Broken Chromosome Ends

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    In budding yeast, an HO endonuclease-inducible double-strand break (DSB) is efficiently repaired by several homologous recombination (HR) pathways. In contrast to gene conversion (GC), where both ends of the DSB can recombine with the same template, break-induced replication (BIR) occurs when only the centromere-proximal end of the DSB can locate homologous sequences. Whereas GC results in a small patch of new DNA synthesis, BIR leads to a nonreciprocal translocation. The requirements for completing BIR are significantly different from those of GC, but both processes require 5′ to 3′ resection of DSB ends to create single-stranded DNA that leads to formation of a Rad51 filament required to initiate HR. Resection proceeds by two pathways dependent on Exo1 or the BLM homolog, Sgs1. We report that Exo1 and Sgs1 each inhibit BIR but have little effect on GC, while overexpression of either protein severely inhibits BIR. In contrast, overexpression of Rad51 markedly increases the efficiency of BIR, again with little effect on GC. In sgs1Δ exo1Δ strains, where there is little 5′ to 3′ resection, the level of BIR is not different from either single mutant; surprisingly, there is a two-fold increase in cell viability after HO induction whereby 40% of all cells survive by formation of a new telomere within a few kb of the site of DNA cleavage. De novo telomere addition is rare in wild-type, sgs1Δ, or exo1Δ cells. In sgs1Δ exo1Δ, repair by GC is severely inhibited, but cell viaiblity remains high because of new telomere formation. These data suggest that the extensive 5′ to 3′ resection that occurs before the initiation of new DNA synthesis in BIR may prevent efficient maintenance of a Rad51 filament near the DSB end. The severe constraint on 5′ to 3′ resection, which also abrogates activation of the Mec1-dependent DNA damage checkpoint, permits an unprecedented level of new telomere addition

    Development of DNA-Biochip for Identification of Influenza A Virus Subtypes

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    Developed was the DNA-biochip to identify subtypes of influenza A virus, pathogenic for humans. Microchip was capable of detecting H1, H3, H5-subtypes of hemagglutinin (including H1-subtype of pandemic A/H1N1(2009) influenza virus ) and neuraminidase subtypes N1,N2 of influenza virus. This microchip was successfully tested on the strains of A/H5N1 highly pathogenic avian influenza virus, A/H1N1(2009) pandemic influenza virus, A/H1N1 and A/H3N2 seasonal influenza viruses
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