Turbulence Model Development Using Approximate Bayesian Computation

Turbulent flows are present in a wide variety of real-world engineering problems, often by design due to their favorable mixing characteristics. At the same time, however, these flows are challenging to simulate due to the computational cost of resolving the wide ranges of spatial and temporal scales associated with practical engineering applications. There are two main approaches --- large-eddy simulations (LES) and Reynolds averaged Navier Stokes (RANS) simulations --- to reduce the computational cost of such simulations, and both approaches use models to represent unresolved small-scale processes and close the governing equations. To date, however, there is still no universally accurate closure model for either LES or RANS, and the most widely used models continue to employ empirical coefficients that have been calibrated for different flows and geometries. To achieve more flexible turbulence model calibration using a range of reference data sources, in this dissertation we develop and demonstrate a method based on approximate Bayesian Computation (ABC). This approach provides probability distributions of calibrated parameters, and thus naturally provides uncertainties in parameter estimates. Moreover, compared to full Bayesian analyses, the ABC approach does not require the direct computation of a likelihood function, thereby enabling substantially faster estimation of unknown parameters and the calibration of more complicated models. In this dissertation, we describe the ABC approach in detail, including the use of a Markov chain Monte Carlo (MCMC) technique, calibration step, adaptive proposal, and a linear regression correction. We demonstrate the baseline ABC method without MCMC by estimating unknown boundary conditions in simulations of turbulent buoyant jets, where lower-dimensional experimental measurements from laser absorption spectroscopy are used as reference data. Then, to demonstrate how the ABC approach can be applied to turbulence model calibration, we estimate parameters for three different turbulence models. First, ABC and MCMC methods are used to estimate values of model coefficients, as well as their joint probability distributions, in a subgrid-scale nonlinear model for LES of turbulent flows. The results from both a priori and a posteriori tests are provided for homogeneous isotropic turbulence. We also demonstrate how parameters can be calibrated without external reference data using ABC in an autonomic closure procedure. Second, we use ABC and MCMC to estimate parameters in a nonequilibrium anisotropy closure for RANS simulations of unsteadily strained homogeneous flows. Unknown model parameters are estimated based on turbulence kinetic energy reference data for four impulsively-sheared homogeneous turbulence test cases, as well as for periodically-sheared homogeneous turbulence with five different shearing frequencies. The ABC and MCMC methods are shown to yield parameter values for the nonequilibrium anisotropy closure that provide good agreement between model results and reference data. Finally, we demonstrate the ABC and MCMC approaches applied to a more complicated inhomogeneous flow, in particular the axisymmetric transonic bump case, and calibrate parameters in the RANS Menter Shear-Stress Transport model, using experiments as reference data. In this dissertation, we thus demonstrate how the ABC approach can be applied to successfully calibrate a range of turbulence models, even those containing many parameters and partial differential equations.</p

EDUCATION AS AN AGENT OF RESOCIALIZATION OF ELDERLY PEOPLE

Due to the aging of population there is a need for reevaluation of the importance and the necessity of elderly people’s participation in the life of society and as a result reevaluation of the methods of their adjustment. Modern “third aged people” want to continue living in the habitual rhythm of life, being the full participants of the society even after their retirement. The social portrait of a modern elderly differs significantly from the one 15-20 years ago. The level of medicine in the developed countries provides them with good state of health and therefore they can retain high level of social and emotional activity. Using several countries (Japan, Australia, Canada,) as an example the article aims to present different ways of inclusion of elderly people in socially useful activities in order to solve the problems of the modern society, in other words, to suggest how third aged people may be helpful. The article sums up that giving the opportunity of social and professional activity to the elderly people helps them to prevent social maladjustment and arising feeling of needlessness after the termination of active employment

Gene Conversion amongst Alu SINE Elements

The process of non-allelic gene conversion acts on homologous sequences during recombination, replacing parts of one with the other to make them uniform. Such concerted evolution is best described as paralogous ribosomal RNA gene unification that serves to preserve the essential house-keeping functions of the converted genes. Transposed elements (TE), especially 'Alu' short interspersed elements (SINE) that have more than a million copies in primate genomes, are a significant source of homologous units and a verified target of gene conversion. The consequences of such a recombination-based process are diverse, including multiplications of functional TE internal binding domains and, for evolutionists, confusing divergent annotations of orthologous transposable elements in related species. We systematically extracted and compared 68,097 'Alu' insertions in various primates looking for potential events of TE gene conversion and discovered 98 clear cases of 'Alu–Alu' gene conversion, including 64 cases for which the direction of conversion was identified (e.g., 'AluS' conversion to 'AluY'). Gene conversion also does not necessarily affect the entire homologous sequence, and we detected 69 cases of partial gene conversion that resulted in virtual hybrids of two elements. Phylogenetic screening of gene-converted 'Alus' revealed three clear hotspots of the process in the ancestors of Catarrhini, Hominoidea, and gibbons. In general, our systematic screening of orthologous primate loci for gene-converted TEs provides a new strategy and view of a post-integrative process that changes the identities of such elements

Стрептококк группы В в акушерстве: нерешенные проблемы

For several decades, among all possible pathogens of neonatal infections, group B streptococcus has been one of the leading positions. Sepsis, meningitis, and pneumonia are among the most common clinical manifestations of neonatal infection associated with group B streptococcus. In this review, our goal was to analyze the literature demonstrating a worldwide approach to the prevention of vertical transmission of group B streptococcus from mother to child. When writing the review, scientific publications of foreign and domestic authors from the PubMed database were studied. The review considers the drugs of choice for intranatal antibiotic prophylaxis, and their pharmacodynamic, and pharmacokinetic features. The analysis details the problem of the growth of resistance of group B streptococcus to antibacterial drugs. The antimicrobial activity of lactoferrin was noted at a minimum inhibitory concentration of 500 μg/ml. The presented review also reflects the protective and therapeutic effects of oral intake of probiotics containing Lactobacillus acidophilus, Lactobacillus salivarius, Lactobacillus rhamnosus GR-1, and Lactobacillus reuteri RC-14 . Based on the analysis, it can be concluded that penicillin G and ampicillin have the most pronounced bactericidal effect against group B streptococcus. At the same time, the most common side effects of β-lactam penicillins include an allergic reaction with the possible development of anaphylactic shock. Given this, the antibiotics of the first-line reserve group include cefazolin, clindamycin, and vancomycin. At the same time, it is important to take into account the decrease in the therapeutic concentration of clindamycin with a change in the alpha-1-acid glycoprotein in the blood of the mother and fetus, the nephrotoxic effect of vancomycin and the cross-a llergic reaction of cefazolin with antibiotics of the penicillin group. A promising direction in solving the problem of group B streptococcus is the development of new strategies for the prevention of perinatal infection of the fetus and newborn based on a more detailed study of the effects of lactoferrin and probiotics.На протяжении нескольких десятилетий среди всех возможных возбудителей неонатальных инфекций стрептококк группы В занимает одну из ведущих позиций. Сепсис, менингит и пневмонию относят к наиболее частым клиническим проявлениям неонатальной инфекции, ассоциированной стрептококком группы В. В рамках данного обзора перед нами стояла цель - провести анализ литературных источников, демонстрирующих всемирный подход к профилактике вертикальной трансмиссии стрептококка группы В от матери ребенку. При написании обзора изучены научные публикации зарубежных и отечественных авторов из базы данных PubMed. В обзоре рассмотрены препараты выбора для проведения интранатальной антибиотикопрофилактики, их фармакодинамические и фармакокинетические особенности. При анализе детализирована проблема роста резистентности стрептококка группы В к антибактериальным препаратам. Отмечена антимикробная активность лактоферрина в минимальной ингибирующей концентрации 500 мкг/мл. Также в представленной работе отражены протективные и терапевтические эффекты перорального приема пробиотиков, содержащих Lactobacillus acidophilus, Lactobacillus salivarius, Lactobacillus rhamnosus GR - 1 и Lactobacillus reuteri RC - 14. На основании анализа можно сделать вывод, что пенициллин G и ампициллин оказывают наиболее выраженное бактерицидное действие против стрептококка группы В. При этом к наиболее частым побочным эффектам β-лактамных пенициллинов относят аллергическую реакцию с возможным развитием анафилактического шока. Ввиду этого, к антибиотикам группы резерва первой линии относят: цефазолин, клиндамицин и ванкомицин. Вместе с тем важно учитывать снижение терапевтической концентрации клиндамицина при изменении показателя альфа-1-кислого гликопротеина в крови матери и плода, нефротоксическое действие ванкомицина и перекрестную аллергическую реакцию цефазолина с антибиотиками группы пенициллинов. Перспективным направлением в решении проблемы стрептококка группы В является разработка новых стратегий профилактики перинатального инфицирования плода и новорожденного на основе более детального изучения эффектов лактоферрина и пробиотиков

Supplementary Table S1-3

Retrotransposon presence/absence pattern

Data from: True homoplasy of retrotransposon insertions in primates

How reliable are the presence/absence insertion patterns of the supposedly homoplasy-free retrotransposons, that were randomly inserted in the quasi infinite genomic space? To systematically examine this question in an up-to-date, multi-genome comparison, we screened millions of primate transposed Alu SINE elements for incidences of homoplasious precise insertions and deletions. In genome-wide analyses, we identified and manually verified nine cases of precise parallel Alu insertions of apparently identical elements at orthologous positions in two ape lineages and twelve incidences of precise deletions of previously established SINEs. Correspondingly, eight precise parallel insertions and no exact deletions were detected in a comparison of lemuriform primate and human insertions spanning the range of primate diversity. With an overall frequency of homoplasious Alu insertions of only 0.01% (for human-chimpanzee-rhesus macaque) and 0.02-0.04% (for human-bushbaby-lemurs) and precise Alu deletions of 0.001-0.002% (for human-chimpanzee-rhesus macaque), real homoplasy is not considered to be a quantitatively relevant source of evolutionary noise. Thus, presence/absence patterns of Alu retrotransposons and, presumably, all LINE1-mobilized elements represent indeed the virtually homoplasy-free markers they are considered to be. Therefore, ancestral incomplete lineage sorting and hybridization remain the only serious sources of conflicting presence/absence patterns of retrotransposon insertions, and as such are detectable and quantifiable

Improvement of methodological support of internal control in the cash management system of the enterprise

Currently, most business operations conducted by an economic entity, including the implementation of settlements with counterparties, associated with the movement of cash flows. Consequently, of particular relevance acquired questions implementation of internal control, which contributes to information and advisory support and optimization of financial and economic activities of the enterprise. The purpose of the article is to develop the system of methodological support of internal control of funds at the enterprise. In article theoretical bases of realization of control procedures are studied. The basic principles, the purpose and methods of internal control of funds are defined. For the development of methodological tools it is suggested to use the developed forms of working documents of internal control. These documents allow to systematize control measures, to evaluate the efficiency of accounting system organization, to generalize the results of cash and bank account transactions inspection, their appropriateness and validity; to record the revealed violations by the results of cash and bank account transactions inspection. Based on the results of internal control, the company’s management makes a decision to improve the efficiency of cash usage based on the creation of a liquidity management system

Cultural assimilator as a technology for preventing maladaptation of foreign students

The article summarizes the author’s experience of using the technology of cultural assimilator for the prevention of maladjustment of foreign students of the university. The procedure for the stage-by-stage construction of cultural assimilator episodes using the technique of a critical incident and an expert method is disclosed. The example shows the options for teaching Russian and Chinese students