Hyperfine structure of EPR spectra of Gd3+ odd isotopes in PbMoO4, Pb5Ge3O11, YVO4, and quadrupole interaction (temperature dependence)

A hyperfine structure of EPR signals of odd isotopes Gd3+ in Pb5Ge3O11, PbMoO4, and YVO4 single crystals has been investigated at different temperatures. The observation of forbidden (with the nuclear spin flip) transitions has made it possible to determine quadrupole interaction P2 0 associated with the gradient of the electric field of ligands at the impurity. It has been shown for the first time that, under the condition pipeP2 0pipe ≥ pipeAx, ypipe (Ai are the tensor components), not only the magnitudes of splitting but also the observed asymmetry in a hyperfine structure (in perpendicular orientations of the magnetic field) depends on mutual signs of parameters of initial splitting b2 0 and P2 0. Results of studying the spectra have demonstrated that pipeb2 0(T)pipe/pipeP2 0(T)pipe ∼ const for a concrete single crystal, which assumes the similarity of physical mechanisms determining these parameters. © 2013 Pleiades Publishing, Ltd

Mathematical model of a two-stage process of laser fragmentation of nitrocompound molecules and subsequent laser-induced fluorescence of characteristic fragments

The paper presents a mathematical model describing the kinetics of the two-stage process of laser fragmentation of vapors of nitrocompounds and subsequent nitric oxide (NO-fragments) laser-induced fluorescence. The use of the developed model in the lidar equation for the case of fluorescent objects allows to calculate the expected value of the lidar signal for a particular nitrocompound on the basis of spectroscopic information about the object of detection, parameters of the radiation propagation medium, and transceiver equipment parameter

Relative effects of mutability and selection on single nucleotide polymorphisms in transcribed regions of the human genome

<p>Abstract</p> <p>Motivation</p> <p>Single nucleotide polymorphisms (SNPs) are the most common type of genetic variation in humans. However, the factors that affect SNP density are poorly understood. The goal of this study was to estimate the relative effects of mutability and selection on SNP density in transcribed regions of human genes. It is important for prediction of the regions that harbor functional polymorphisms.</p> <p>Results</p> <p>We used frequency-validated SNPs resulting from single-nucleotide substitutions. SNPs were subdivided into five functional categories: (i) 5' untranslated region (UTR) SNPs, (ii) 3' UTR SNPs, (iii) synonymous SNPs, (iv) SNPs producing conservative missense mutations, and (v) SNPs producing radical missense mutations. Each of these categories was further subdivided into nine mutational categories on the basis of the single-nucleotide substitution type. Thus, 45 functional/mutational categories were analyzed. The relative mutation rate in each mutational category was estimated on the basis of published data. The proportion of segregating sites (PSSs) for each functional/mutational category was estimated by dividing the observed number of SNPs by the number of potential sites in the genome for a given functional/mutational category. By analyzing each functional group separately, we found significant positive correlations between PSSs and relative mutation rates (Spearman's correlation coefficient, at least r = 0.96, df = 9, <it>P </it>< 0.001). We adjusted the PSSs for the mutation rate and found that the functional category had a significant effect on SNP density (F = 5.9, df = 4, <it>P </it>= 0.001), suggesting that selection affects SNP density in transcribed regions of the genome. We used analyses of variance and covariance to estimate the relative effects of selection (functional category) and mutability (relative mutation rate) on the PSSs and found that approximately 87% of variation in PSS was due to variation in the mutation rate and approximately 13% was due to selection, suggesting that the probability that a site located in a transcribed region of a gene is polymorphic mostly depends on the mutability of the site.</p

The contradiction of the public education reform in the USSR at the end of the 1950s. - early 1960s.

Introduction. The relevance of the topic of the article is due to the importance of the Soviet education system in the development of Russian society, despite political, economic and social changes in society. The article analyzes the reasons for the reform of public education in the USSR in the late 1950s – early 1960s, examines the concept of polytechnic training in Soviet secondary schools in the late 1950s, combining schooling with productive labor. The concept of polytechnic training in Soviet secondary schools stimulated the reform of public education. The restructuring of secondary and higher education was designed to play a major role in eliminating the essential difference between physical and mental labor, in creating the conditions necessary for the country's transition to communism.Materials and methods. This study is based on an analysis of documents related to party office work in the 1960s-80s: decrees, resolutions and decisions of congresses, conferences and plenums of the Central Committee of the CPSU. The methodological basis of the research is a complex of general scientific, special historical methods, as well as the theory of modernization. The retrospective method, evaluating events and phenomena in their historical development, played a big role. A comparative analysis made it possible to compare the documentation of different times in order to establish the qualitative level of the changes taking place in the USSR in the field of education.Results. The article analyzes the problems of the formation of the Soviet polytechnic school. In the conditions of a planned economy, technical schools and vocational schools of the USSR trained specialists primarily for the needs of Soviet industry. The role of public education, the increase in the number of extended-day schools and boarding schools is considered. The inconsistency of the reform of public education in the USSR, which did not bring the expected results, is analyzed. The emphasis on the polytechnic school did not allow the development of the scientific component, interfering with the intellectual development of school students, the education reform led to a deterioration in the quality of the study of basic sciences.Conclusion. The article uses special historical methods: comparative historical, retrospective, chronological. The study was carried out on the basis of a problem-historical analysis taking into account the social conditions of that time

Enhancement of the Raman lidar sensitivity using overtones of vibrational-rotational Raman bands of oxygen or nitrogen as the reference signals

Influence of the vibrational-rotational Raman bands of molecules of the main components of the atmosphere (oxygen and nitrogen) on the sensitivity of Raman lidar is considered. A method is proposed of using the first overtones of the vibrational-rotational Raman bands of oxygen and nitrogen molecules as the reference signals for the measurement of low concentrations of chemicals in the atmosphere by the Raman method

Genes With a Large Intronic Burden Show Greater Evolutionary Conservation on the Protein Level

Background: The existence of introns in eukaryotic genes is believed to provide an evolutionary advantage by increasing protein diversity through exon shuffling and alternative splicing. However, this eukaryotic feature is associated with the necessity of exclusion of intronic sequences, which requires considerable energy expenditure and can lead to splicing errors. The relationship between intronic burden and evolution is poorly understood. The goal of this study was to analyze the relationship between the intronic burden and the level of evolutionary conservation of the gene. Results: We found a positive correlation between the level of evolutionary conservation of a gene and its intronic burden. The level of evolutionary conservation was estimated using the conservation index (CI). The CI value was determined on the basis of the most distant ortholog of the human protein sequence and ranged from 0 (the gene was unique to the human genome) to 9 (an ortholog of the human gene was detected in plants). In multivariable model, both the number of introns and total intron size remained significant predictors of CI. We also found that the number of alternative splice variants was positively correlated with CI. The expression level of a gene was negatively correlated with the number of introns and total size of intronic region. Genes with a greater intronic burden had lower density of missense and nonsense mutations in the coding regions of the gene, which suggests that they are under a stronger pressure from purifying selection. Conclusions: We identified a positive association between intronic burden and CI. One of the possible explanations of this is the idea of a cost-benefits balance. Evolutionarily conserved (functionally important) genes can “afford” the negative consequences of maintaining multiple introns because these consequences are outweighed by the benefit of maintaining the gene. Evolutionarily conserved and functionally important genes may use introns to create novel splice variants to tune the gene function to developmental stage and tissue type

Developing Methods and Algorithms for Cloud Computing Management Systems in Industrial Polymer Synthesis Processes

To date, the resources and computational capacity of companies have been insufficient to evaluate the technological properties of emerging products based on mathematical modelling tools. Often, several calculations have to be performed with different initial data. A remote computing system using a high-performance cluster can overcome this challenge. This study aims to develop unified methods and algorithms for a remote computing management system for modelling polymer synthesis processes at a continuous production scale. The mathematical description of the problem-solving algorithms is based on a kinetic approach to process investigation. A conceptual scheme for the proposed service can be built as a multi-level architecture with distributed layers for data storage and computation. This approach provides the basis for a unified database of laboratory and computational experiments to address and solve promising problems in the use of neural network technologies in chemical kinetics. The methods and algorithms embedded in the system eliminate the need for model description. The operation of the system was tested by simulating the simultaneous statement and computation of 15 to 30 tasks for an industrially significant polymer production process. Analysis of the time required showed a nearly 10-fold increase in the rate of operation when managing a set of similar tasks. The analysis shows that the described formulation and solution of problems is more time-efficient and provides better production modes. Doi: 10.28991/esj-2021-01324 Full Text: PD

Why are female engineers so rare? Reasons for a gender-based choice of profession. Germany in comparison to Sweden

Diese Arbeit befasst sich mit den Möglichkeiten der Umgestaltung des Geschlechterverhältnisses, das sich in der Beziehung der Frauen und Männer zur Technik widerspiegelt. Die Frage, warum Frauen keine Ingenieurberufe wählen, wird aus soziologischer Sicht beleuchtet. Geschlechtsspezifische Sozialisation und strukturelle Rahmenbedingungen der Gesellschaft sind nicht die primären Gründe dafür. Die Geschlechter, als soziale Kategorie, stehen in einem Herrschaftsverhältnis zueinander. Diese soziale Ordnung ist im geschlechtsspezifischen Habitus verankert und korrespondiert mit dem beruflichen Habitus. So steht der naturwissenschaftlich-technische Habitus im Widerspruch zum weiblichen Habitus, was zum Ausschluss der Frauen aus dem technischen Feld führt. Eine symbolische Revolution sollte nach Bourdieu die herrschenden Strukturen in Frage stellen. Der Zusammenhang zwischen den Geschlechterleitbildern und dem Zugang der Frauen zu technischen Berufen wird im Vergleich von Deutschland und Schweden deutlich. Dieser zeigt, welche Maßnahmen in Schweden zur Umgestaltung traditioneller Rollenmuster beigetragen haben.This paper addresses the possibility of reforming the gender relationship which is reflected in the different relation of men and women to technology and the technical field. The question why women rarely choose a profession in the field of engineering is examined from a sociological point of view. Gender specific socialisation and the structural framework of society are not the primary reasons. Socially, the relation of one gender to the other has a hierarchical character. This social order is rooted in gender-specific habitus and corresponds closely to the job related habitus. Thus, the scientific-technical habitus conflicts with the female habitus, which leads to the exclusion of women from the field of engineering. According to Bourdieu, a symbolic revolution should challenge existing structures. The correlation between gender role models and the access of women to technical professions can be seen more clearly through the comparison of German and Swedish models. This comparison shows which measures have led to a realignment of traditional gender role models in Sweden

Mechanisms of Oxidative Stress an d Vessels Sclerotic Transformation Initiated by Uremic Toxin Indoxyl Sulfate

The microspherical carbonaceous adsorbents SCN and AST-120 for oral use prevent chronic disease progression, delay dialysis initiation, lessen atherosclerosis development in kidney and decreased of overall and cardiovascular mortality. This therapeutic effect is due to the binding of indole by sorbents in large intestine, which is a precursor of indoxyl sulfate (IS). It is considered that IS accelerates the progression of chronical kidney disease (CKD) by inducing a formation of reactive oxygen species (ROS) and promotes aortic calcification (mineralization). Molecular mechanisms of IS action is unknown. Using density functional theory calculations in the frames of B3LYP exchange and correlation functional (basis set 6-311G) and solvation accounting on the base of polarizable continuum model (PCM) we have studied some chemical transformations of IS and have shown a possibility of indoxyl sulfate and hydroperoxyl radicals formation through the reaction of IS with endogenous singlet oxygen. Due to the high activity indoxyl sulfate radicals initiate uncontrollable processes of oxidative stress (OS) in kidney and vascular tissues that promote a development of CKD. We also proposed a hypothesis, which can explain the role of OS in the accelerated development of sclerosis (vessels mineralization) in patients with renal diseases. In particular it was hypothesized and then supported by B3LYP/6-311G(d) + PCM calculations that sulfonic groups (products of deep oxidation of thiol groups in tissue proteins under OS, induced by IS) can selectively bind of Ca2+ ions and, consequently, forming RSO3Ca+ groups which can fix НРО42ˉ and CO32ˉ anions. The products of anions fixation can then bind of Ca2+ ions, etc. Notably, these processes are, probably, primary starting point in case of sclerotic vessel changes. The beginning of this starting mineralization process most likely is possible with proteins carboxyl groups forming under OS that also can bind Ca2+

On the correlation between dye coverage and photoelectrochemical performance in dye-sensitized solar cells

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (http://creativecommons.org/licenses/by/3.0/)Concentration depth profiles of the ruthenium based dyes Z907 and N719 adsorbed onto titania are measured directly and used for determining the adsorption isotherm of the dyes. Dye layers formed by both grow in islands on the titania which do not cover the entire titania surface even at the maximum coverage. Impedance spectroscopy in conjunction with the adsorption isotherms shows that recombination losses mainly appear between the dye and the electrolyte solution. The short circuit current and the efficiency increase linearly with the dye coverage. The open circuit voltage slightly increases with increasing dye coverage which is interpreted as most likely to be a consequence of the higher charge in the particles upon higher dye loading on the TiO2 surface