Dependent coordinates in path integral measure factorization

The transformation of the path integral measure under the reduction procedure in the dynamical systems with a symmetry is considered. The investigation is carried out in the case of the Wiener--type path integrals that are used for description of the diffusion on a smooth compact Riemannian manifold with the given free isometric action of the compact semisimple unimodular Lie group. The transformation of the path integral, which factorizes the path integral measure, is based on the application of the optimal nonlinear filtering equation from the stochastic theory. The integral relation between the kernels of the original and reduced semigroup are obtained.Comment: LaTeX2e, 28 page

REMAGNETIZATION PROCESSES IN SINTERED Sm-Co И Nd-Fe-B PERMANENT MAGNETS

The processes of remagnetization in permanent magnets of the Sm2Co17 and Nd2Fe14B systems were studied. The mechanism for the formation of coercivity is established via su-perposition coherent rotation or pinning in accordance of the Kondorski and Stoner-Wohlfarth models.Проект выполнен при финансовой поддержке Российского фонда фундаментальных исследований, грант № 20-32-90211\20

Pathogenicity of the SARS-CoV-2 Virus Variants of Concern for the Syrian Golden Hamster

The aim of the work was to study the pathogenicity of newly emerging variants of SARS-CoV-2 on the model of the Syrian golden hamster.Materials and methods. We used the strains of SARS-CoV-2 virus related to the VOC circulating in the territory of the Russian Federation. The experiments were carried out on outbreed Syrian hamsters obtained from the nursery of the SSC VB “Vector”. The infectious titer of coronavirus in tissue samples collected from infected laboratory animals was determined on a Vero E6 cell culture. The Ct in RT-PCR was considered an additional parameter for monitoring the viral load in the samples. The severity of lung tissue damage in Syrian hamsters with COVID-19 was assessed by histological preparations.Results and discussion. 50 % infecting doses in case of the intranasal infection have been determined, histological analysis of lung tissues performed. The pathogenicity of various variants of the SARS-CoV-2 virus for the Syrian hamster has been evaluated, differences in infecting doses and pathological changes in the lungs have been revealed. SARS-CoV-2 viruses belonging to Beta genetic variant have the highest virulence, while Alpha variant has the lowest one when comparing the studied strains by the ID50 value. The Delta and Omicron variants have a matched ability to cause specific damage to the tissues of the respiratory tract, while being inferior only to the Beta variant. It has been demonstrated that Syrian hamsters are an adequate model for assessing the pathogenicity of the SARS-CoV-2 virus variants of concern. Variants of SARS-CoV-2 virus during intranasal infection has shown different degree of pathogenicity in the Syrian hamster model

Evaluation of a strategy for tumor-initiating stem cell eradication in primary human glioblastoma cultures as a model

Primary cultures of human glioblastoma were obtained from the surgical material of patients K. (female, 61 years, Ds: relapse of glioblastoma) and Zh. (female, 60 years, Ds: relapse of glioblastoma). The effectiveness of a new therapeutic approach aimed at destroying the cancer cell community was evaluated on the primary cell lines of human glioblastoma culture by employing a new strategy of tumor-initiating stem cell synchronization and a domestic strategy of their eradication "3+1". The key elements of the strategy were the following indicator results: (1) evaluation of the presence of tumor-initiating stem cells in a population of cells from analyzed cultures by their ability to internalize double-stranded labeled DNA (TAMRA+ cells); (2) determination of the reference time points of the repair cycle of DNA interstrand cross-links induced by cross-linking cytostatic mitomycin C; (3) evaluation of cell cycle synchronization; (4) determination of the time (day after therapy initiation) when TAMRA+ cells were synchronously present in phase G1/S of the cell cycle, sensitive to the therapy; and (5) establishment of the TAMRA+ (tumor-initiating stem cells) eradication schedule. The cultures were treated with cross-linking cytostatic mitomycin C and a compositional DNA preparation. After the treatments, cell division slows down, and the cultures degrade. The K cell line completely degraded within 30 days of observation. The cell number of the Zh culture fell to nearly one-third of the starting value by day 15 of observation. On day 15, this indicator constituted 1/7.45 for mitomycin C and 1/10.28 for mitomycin C + DNA with reference to the control. The main target of the mitomycin C + DNA regimen was TAMRA+ tumor-initiating stem cells of the glioblastoma cell populations. The action of mitomycin C alone or in the combination with DNA demonstrated effective elimination of TAMRA+ tumor-initiating stem cells and the whole primary cultures of human glioblastomas

Possibility of using a mouse SCID as a model animal to variola virus for evaluating anti-smallpox drug efficacy

At present, there is no animal model for smallpox that reflects the weakened immune system in people and can therefore help assess the prophylactic (highly preventive) efficiency of antiviral drugs. To fill in the gap, we have explored the possibility of using outbred immunodeficient SCID mice as a model animal for smallpox with the aid of virolo­gical, histological and electron microscopic and sta­tistical methods. There was no clinical evidence of disease by intranasal infection of mice at a dose of 5.2 log10 PFU (plaque forming units). At the same time, the 50 % infective dose (ID50) of VARV estimated for animals by registering the presence of the virus in their lungs after 4 days post i.n. infection was 3.5 log10 PFU and was relatively similar to that in humans, theoretically determined by identification of the clinical picture of the disease. Virus replication was detected only in the respiratory organs of mice challenged i.n. with VARV at a dose of 5.2 log10 PFU (50 ID50). The values for its concentrations in the lungs and nose resembled those for affected people and well-known animal models (Macaca cynomolgus and ICR mice), respiratorily infected with VARV at similar doses. The existing model animals were not significantly different from SCID mice in the duration of viral presence in the lungs. Moreover, in SCID mice, as in humans and other animal models, similar pathomor- phological changes of inflammatory necrotic nature in the respiratory organs have been reported. Using SCID mice in assessing the prophylactic efficacy of the antiviral drugs NIOCH-14 and ST-246 demonstrated the adequacy of the results obtained to those described in the literature. This opens up the prospect of using SCID mice as an animal model for smallpox to develop antiviral drugs intended for people with severe immuno­suppressive states

Understanding complex dynamics of behavioral, neurochemical and transcriptomic changes induced by prolonged chronic unpredictable stress in zebrafish

Stress-related neuropsychiatric disorders are widespread, debilitating and often treatment-resistant illnesses that represent an urgent unmet biomedical problem. Animal models of these disorders are widely used to study stress pathogenesis. A more recent and historically less utilized model organism, the zebrafish (Danio rerio), is a valuable tool in stress neuroscience research. Utilizing the 5-week chronic unpredictable stress (CUS) model, here we examined brain transcriptomic profiles and complex dynamic behavioral stress responses, as well as neurochemical alterations in adult zebrafish and their correction by chronic antidepressant, fluoxetine, treatment. Overall, CUS induced complex neurochemical and behavioral alterations in zebrafish, including stable anxiety-like behaviors and serotonin metabolism deficits. Chronic fluoxetine (0.1 mg/L for 11 days) rescued most of the observed behavioral and neurochemical responses. Finally, whole-genome brain transcriptomic analyses revealed altered expression of various CNS genes (partially rescued by chronic fluoxetine), including inflammation-, ubiquitin- and arrestin-related genes. Collectively, this supports zebrafish as a valuable translational tool to study stress-related pathogenesis, whose anxiety and serotonergic deficits parallel rodent and clinical studies, and genomic analyses implicate neuroinflammation, structural neuronal remodeling and arrestin/ubiquitin pathways in both stress pathogenesis and its potential therapy. © 2020, The Author(s).The research was supported by the Russian Science Foundation (RSF) Grant 19‐15‐00053. KAD is supported by the President of Russia Graduate Fellowship, the Special Rector’s Productivity Fellowship for SPSU PhD Students, and the Russian Foundation for Basic Research (RFBR) grant 18‐34‐00996. ADP was supported by St. Petersburg University (project ID 51555422). The research team was supported by St. Petersburg State University state budgetary funds (project ID 51130521). AVK is the Chair of the International Zebrafish Neuroscience Research Consortium (ZNRC) and President of the International Stress and Behavior Society (ISBS, www.stress-and-behavior.com) that coordinated this collaborative multi-laboratory project. The consortium provided a collaborative idea exchange platform for this study. It is not considered as an affiliation, and did not fund the study. AVK is supported by the Southwest University Zebrafish Platform Construction Fund. TGA’s research is supported by the budgetary funding for basic research from the Scientific Research Institute of Physiology and Basic Medicine (AAAA-A16-116021010228-0, Novosibirsk, Russia). This study utilized equipment of the Core Facilities Centre “Centre for Molecular and Cell Technologies” of St. Petersburg State University. The funders had no role in the design, analyses, and interpretation of the submitted study, or decision to publish

МЕТОДОЛОГІЯ ПОБУДОВИ МАТЕМАТИЧНОЇ МОДЕЛІ ЗАБЕЗПЕЧЕННЯ ПАЛЬНИМ АВТОБРОНЕТАНКОВОЇ ТЕХНІКИ НАЦІОНАЛЬНОЇ ГВАРДІЇ УКРАЇНИ (НА ПРИКЛАДІ АВТОМОБІЛЯ КрАЗ-6322)

The author proposes to consider mathematical modeling as a simplified form of the representation of real processes and interconnections in the system, which allows studying, evaluating and predicting the influence of the constituent elements (factors) on the behavior of the system as a whole (a set of interrelated elements). The accuracy of the mathematical model of the process should be increased mainly for important operations, their importance should be expressed through economic and technical indicators. Simplification of the mathematical model can be achieved by excluding nonessential variables, changing the nature of variables (assuming some value is constantly variable instead of discrete), replacing nonlinear with linear equations (linearization of equations).The author proposes the following procedure for developing a mathematical model: the formulation of the problem in such a way as to ensure the uniqueness of its understanding. Then the identification of the theory of processes, the physicochemical laws of the process based on the literature and experimental data of other researchers, and in the absence of such data, the nomination of a working hypothesis with its subsequent verification. On the basis of physicochemical laws or the accepted working hypothesis, the compilation of a single equation or system of equations relating parameters to facts in the simplest and clearest form, the determination of the method of solving the adopted mathematical equations, methods for determining the parameters of the equation. Then it checks the conformity of the adopted model to the actual process when there is evidence and comparing it with the calculated ones using a mathematical model.The mathematical model of fuel consumption should be based on a fairly accurate equation that takes into account the variety of operating conditions for cars and arises from the theory of the car, as well as an algorithm for solving it, which allows for simulation modeling.Автори пропонують розглянути математичне моделювання як спрощену форму подання реальних процесів і взаємозв’язків у системі, що дозволяє вивчити, оцінити і прогнозувати вплив складових елементів (факторів) на поведінку системи в цілому (сукупність взаємопов’язаних елементів). Точність математичної моделі процесу слід підвищувати, головним чином, на важливих операціях, важливість їх слід виражати через економічні і технічні показники. Пропонується порядок розробки математичної моделі

Effect of shock wave treatment at low and high temperatures on the mechanical and structural properties of ferrous alloys

Translated from Russian (Report of the A.A. Balikov Institute of Metallurgy and Materials Science, Moscow, 2000)Available from British Library Document Supply Centre-DSC:9023.190(10401)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

A RDMA Interface for Ultra-Fast Ultrasound Data-Streaming over an Optical Link

Digital ultrasound (US) probes integrate the analog-to-digital conversion directly on the probe and can be conveniently connected to commodity devices. Existing digital probes are however limited to a relatively small number of channels, do not guarantee access to the raw US data, or cannot operate at very high frame rates (e.g., due to exhaustion of computing and storage units on the receiving device). In this work, we present an open, compact, power-efficient, 192-channels digital US data acquisition system capable of streaming US data at transfer rates greater than 80 Gbps towards a host PC for ultra-high frame rate imaging (in the multi-kHz range). Our US probe is equipped with two power-efficient Field Programmable Gate Arrays (FPGAs) and is interfaced to the host PC with two optical-link 100G Ethernet connections. The high-speed performance is enabled by implementing a Remote Direct Memory Access (RDMA) communication protocol between the probe and the controlling PC, that utilizes a high-performance Non-Volatile Memory Express (NVMe) interface to store the streamed data. To the best of our knowledge, thanks to the achieved datarates, this is the first high-channel-count compact digital US platform capable of raw data streaming at frame rates of 20 kHz (for imaging at 3.5 cm depths), without the need for sparse sampling, consuming less than 40 W