525 research outputs found

    The parallax distorsion via a weak microlensing effect

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    Parallax measurements allow distances to celestial objects to be determined. Coupled with measurement of their position on the celestial sphere, it gives a full three-dimensional picture of the location of the objects relative to the observer. The distortion of the parallax value of a remote source affected by a weak microlensing is considered. This means that the weak microlensing leads to distortion of the distance scale. It is shown that the distortions to appear may change strongly the parallax values in case they amount to several microseconds of arc. In particular, at this accuracy many measured values of the parallaxes must be negative.Comment: 34 LaTeX pages, 12 PostScript figure (epsfig.sty

    Microarcsecond instability of the celestial reference frame

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    The fluctuation of the angular positions of reference extragalactic radio and optical sources under the influence of the irregular gravitational field of visible Galactic stars is considered. It is shown that these angular fluctuations range from a few up to hundreds of microarcseconds. This leads to a small rotation of the celestial reference frame. The nondiagonal coefficients of the rotation matrix are of the order of a microarcsecond. The temporal variation of these coefficients due to the proper motion of the foreground stars is of the order of one microsecond per 20 years. Therefore, the celestial reference frame can be considered inertial and homogeneous only to microarcsecond accuracy. Astrometric catalogues with microarcsecond accuracy will be unstable, and must be reestablished every 20 years.Comment: 5 pages, 2 figures, accepted to MNRA

    Formation of Anthropometric, Functional and Psychophysiological Indicators in Students of Medical Colleges under the Influence of Physical Activity

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    Purpose: to define the dynamics of physical development indicators among medical college students in 2017 and to compare it with the results of the previous study of 2005. Method: The inclusion criteria were: no health complaints at the time of the examination, no chronic diseases in family medical history, no deviations from the norm in clinical and laboratory tests. The selected young men were examined by medical specialists (neuropathologist, ophthalmologist, otolaryngologist, therapist, surgeon); detailed clinical, laboratory and diagnostic tests were conducted: X-ray; spirography; electrocardiography; dental examination; ultrasound examination (cardiovascular, thyroid, abdominal, urological); biochemical blood testing. The participants were subdivided into two groups: Group 1 (students (n=140) who studied at Zhytomyr Medical College in 2004-2005) and Group 2 (students (n=150) who studied at Zhytomyr Medical Institute in 2016-2017). Results: According to the results of studying the dynamics of anthropometric, functional and psychophysiological indicators of physical development among Ukrainian medical college students (n=290; 17-21 years old) in 2017, comparing them with the results of the previous study, conducted in 2005, the tendency to gain in body mass in average values from (0.88 ± 0.26) to (2.7 ± 0.67), in body mass index from (0.88 ± 0.26) to (1.38 ± 0.38), in the fat component from (8.70 ± 0.22) to (9.36 ± 0.21) was established. Conclusions: An increase in body mass index, the fat component in medical college students was revealed, which is related to problems in the quality of the students' diet. Though the muscle mass has increased, and the study indicates that there is insufficient physical activity; sustainability and concentration of attention indicators tend to decrease under the influence of intensification of the educational process. The dynamics of the indicators under analysis indicates the stabilization of the growth process in Ukrainian male students

    Prognostic Significance of the Integral Index of the Alcohol Situation in Assessing Regional Differences in Mortality from Cardiovascular Diseases in the Russian Federation

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    Aim. To evaluate the stability of the integral index of the alcohol situation in the regions of the Russian and its prognostic significance regarding adult mortality from diseases of the circulatory system.Material and methods. The dynamics of standardized mortality rate for cardiovascular diseases (CVD) and TM in 2012 and 2018 in regions of Russia with safe and unsafe alcohol situations was analyzed. The average group mortality rate were evaluated, as well as the average rate of dynamics of the indicator reduction for the period from 2012 to 2018.Results. In 2012, differences in the rates of total mortality, as well as mortality from CSD, IHD, and CVD in regions with different levels of alcohol wellbeing were significant with a significance level of p <0.05. In 2018, intergroup differences in mortality from CSD and IHD were unreliable. Differences in average mortality rates from other causes significantly differed with a significance level of p <0.05. Total mortality and mortality from CVD, including individual forms, decreased in all regions, regardless of the level of alcohol well-being. The average rate of decline in mortality in the group of regions with an unfavorable situation was lower than the same indicator in regions with a favorable situation, with the exception of mortality from CVD. The most pronounced were differences between regions in the rate of decline in mortality from MI (p <0.05). For the remaining causes of death, the differences were not significant.Conclusion. The hypothesis of a significant contribution of the alcohol factor to cardiovascular mortality is confirmed. In the groups of regions that differ in the integral index of the alcohol situation, significant differences were noted in the indicators of both total mortality and mortality from the main groups of cardiovascular diseases. These differences persist over time, which confirms the hypothesis that the proposed integral indicator can be used for a long-term forecast of the influence of the alcohol situation on public indicators

    Factors of successful diversification for machine-building enterprises

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    The relevance of the study is due to the need to diversify production in order to increase competitiveness and strengthen the economic sustainability of enterprises. Increasing the output of high-tech civil and dual-use products by enterprises of the military-industrial complex as part of the conversion is complicated by the lack of enterprises work experience in the market. Conversion of defense industry enterprises is an important and promising task, the solution of which is connected with the future of defense industry enterprises, the development of import substitution, the expansion of high-tech exports. The purpose of the study is to analyze the world experience of conversion, to study existing approaches to solving conversion implementation problems, creating a system of conversion success factors, monitoring the effect of external and internal conversion implementation factors, identifying actual problems of this process. The author's approach to solving conversion problems consists of identifying external and internal conversion success factors and combining them into a single system for the interaction between the state and defense enterprises. The study of the implementation of the indicated factors showed the degree of their development, as well as the directions that will contribute to the development of diversification. © Published under licence by IOP Publishing Ltd

    Large Oligomeric Complex Structures Can Be Computationally Assembled by Efficiently Combining Docked Interfaces

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    Macromolecular oligomeric assemblies are involved in many biochemical processes of living organisms. The benefits of such assemblies in crowded cellular environments include increased reaction rates, efficient feedback regulation, cooperativity and protective functions. However, an atom‐level structural determination of large assemblies is challenging due to the size of the complex and the difference in binding affinities of the involved proteins. In this study, we propose a novel combinatorial greedy algorithm for assembling large oligomeric complexes from information on the approximate position of interaction interfaces of pairs of monomers in the complex. Prior information on complex symmetry is not required but rather the symmetry is inferred during assembly. We implement an efficient geometric score, the transformation match score, that bypasses the model ranking problems of state‐of‐the‐art scoring functions by scoring the similarity between the inferred dimers of the same monomer simultaneously with different binding partners in a (sub)complex with a set of pregenerated docking poses. We compiled a diverse benchmark set of 308 homo and heteromeric complexes containing 6 to 60 monomers. To explore the applicability of the method, we considered 48 sets of parameters and selected those three sets of parameters, for which the algorithm can correctly reconstruct the maximum number, namely 252 complexes (81.8%) in, at least one of the respective three runs. The crossvalidation coverage, that is, the mean fraction of correctly reconstructed benchmark complexes during crossvalidation, was 78.1%, which demonstrates the ability of the presented method to correctly reconstruct topology of a large variety of biological complexes. Proteins 2015; 83:1887–1899. © 2015 The Authors. Proteins: Structure, Function, and Bioinformatics Published by Wiley Periodicals, Inc

    SOCIO-ECONOMIC DAMAGE BY ACUTE CORONARY SYNDROME IN RUSSIAN FEDERATION

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    Aim. To estimate the economic damage by acute coronary syndrome (ACS) in Russia in 2006-2009. Material and Methods. Direct costs and economic losses associated with ACS were estimated. The structure of direct costs includes the costs of hospitalization, medical emergencies, out-patient visits, high-tech medical care, as well as drug therapy in outpatient treatment. Losses in the economy associated with ACS include loss of gross domestic product due to death in working-age, temporary disability and payments of disability benefits. Estimation of economic damage by cardio-vascular diseases was based on analysis of Russian Ministry of Health official statistics. Results. Approximately 520,000 cases of ACS are registered annually (36,4% - myocardial infarction, 63,6% - unstable angina). Trend to increased mortality from myocardial infarction, especially among women, was found during the analyzed period. From 2000 to 2009 this index rose from 34.9 to 41.1 per 100,000 of population among women, and from 52.3 to 55.9 per 100,000 of population among men. Total direct costs of health care for patients with ACS in 2009 amounted to almost 21 billion rubles, and indirect – 53.5 billion rubles. The total economic damage by ACS in Russia in 2008-2009 exceeded 70 billion rubles per year. Conclusion. ACS in Russia is connected with significant social and economic damage. Most part of this damage is indirect losses in economy due to premature mortality of working aged men

    Resistance to viruses of potato: current status and prospects

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    The potato (Solanum tuberosum), one of the most important food crops in the world, is infected by various viruses, nine of which have great economic significance, causing substantial losses in the yield and quality of the crop. To minimize consequences of virus infections, in developed countries specific phytosanitary measures have been established and are being improved to monitor the spread of viruses and certify seed potato material using virus diagnostics and production of virus-free potato cultivars. However, in the longer-term, the development and deployment of potato cultivars resistant to viruses would be a priority. Some new potato cultivars and lines resistant to many viruses have already been generated using either traditional breeding methods or genetic engineering. For this purpose, natural resistance genes, primarily from wild Solanum species, or virus derived nucleotide sequences have been used as sources of resistance. However, these approaches have essential limitations because the acquired resistance is highly specific (against individual viruses only), is not durable, can be overcome by viruses and, finally due to regulatory bans on genetically modified organisms. Recently developed new genome editing technologies with the potential to be a powerful tool for gene design open up broad opportunities for development of next-generation resistance genes. The most promising approaches are (1) site-directed mutagenesis of the genes conferring specific resistance to make their action much broader and (2) the use of non-specific (nonhost) resistance to generate plants resistant to unrelated viruses and, in some cases, to other pathogens and even abiotic stresses. Identification of genes involved in mechanisms of non-host resistance is just beginning. The cell nucleus is a new source of novel factors involved in various signaling pathways resulting in defence response to virus infection. This review focuses on the approaches and challenges related to the development of potato plants resistant to virus infections
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