Mathematical modeling of thermal stabilization of vertical wells on high performance computing systems

Temperature stabilization of oil and gas wells is used to ensure stability and prevent deformation of a subgrade estuary zone. In this work, we consider the numerical simulation of thermal stabilization using vertical seasonal freezing columns. A mathematical model of such problems is described by a time-dependent temperature equation with phase transitions from water to ice. The resulting equation is a standard nonlinear parabolic equation. Numerical implementation is based on the finite element method using the package Fenics. After standard purely implicit approximation in time and simple linearization, we obtain a system of linear algebraic equations. Because the size of freezing columns are substantially less than the size of the modeled area, we obtain mesh refinement near columns. Due to this, we get a large system of equations which are solved using high performance computing systems.Comment: 9 pages, 5 figure

Design and implementation of adaptive technology for teaching mathematics to school children based on integrated diagnostic approach to subject preparation and competence development

The development of school teaching  systems to enable effective adaptive communication of information requires specific pedagogical solutions to several important theoretical and methodological problems .These include 1) the discernment of basic characteristics needed to diagnose and improve the quality of subject preparation for schoolchildren, 2) clarifying the role of the teacher in the structure of adaptive learning  process, and  3) finding ways to integrate adaptive content into the framework of courses on mathematics. The purpose of our study was to determine theoretical and methodological foundations of teaching mathematics to schoolchildren taking into account their level of ability with the consequent development of appropriate adaptive content. The basic characteristics that underpin the concept of adaptive learning which contributes to both individual profiles of student ability to learn and subsequent success outcomes are: proficiency, motivation to learn and level of mathematical knowledge. The evaluation of individual profile structure of schoolchildren determines the choice of methodologies for presentation of adaptive content in ways allowing development and motivation. The system of educational process management developed in this way includes both content-methodical and procedural-technological components. This makes it possible to automatically evaluate the level of each students' mathematical training (knowledge, motivation, development) and to ensure continuous improvement. This system can also be used by secondary teachers of mathematics as a part of extracurricular activities, or as a distance learning support. In addition, the recommendations for structuring multi-level problem material can be used by mathematics teachers to self-construct adaptive sets tasks at various stages of teaching mathematics. As a result, students have the opportunity to improve their own profile of learning success, particularly by solving a chain of tasks

Cell wall functional activity and metal accumulation of halophytic plant species Plantago maritima and Triglochin maritima on the White Sea littoral zone (NW Russia)

The presented study supplements the knowledge on ion-exchange capacity, swelling capacity (elasticity) of the plant cell wall, and the accumulation of heavy metals in halophytic species Plantago maritima and Triglochin maritima in the tidal zone of the White Sea western coast. The littoral soils of the coastal territories are sandy or rocky-sandy, medium and slightly saline with poor content of organic substances, Mn, Zn, Ni, and Pb. Studied soils are considered as uncontaminated by heavy metals because they contain background amounts of Fe and Cu. Sea water is significantly polluted by Fe (3.8 MPC) and Ni (55 MPC), has poor content of Zn and Cu and background level of Pb and Mn. The coastal dominant plant species P. maritima and T. maritima were characterized by intensive metals accumulation which was reflected in the coefficient of biological absorption (CBA) of metal by a whole plant. For P. maritima the following metal accumulation series was obtained: Cu (3.29)> Zn (2.81)> Ni (1.57)> Pb (1.30)> Mn (1.21)> Fe (0.97), and for T. maritima: Ni (3.80)> Fe (2.08)> Cu (1.91)> Zn (1.84)> Pb (1.51)> Mn (1.31). Roots accumulated 50–70% of Ni, Cu, Zn, Pb and Mn of the total metal content in the plant while leaves and stems contained 30–50%. Fe was allocated mainly in the roots (80%). The ion-exchange capacity of the plant cell wall for P. maritima and T. maritima was established as follows correspondingly: 3570–3700 and 2710–3070 μmol g-1 dry cell weight per leaf; 2310–2350 and 1160–1250 μmol g-1 dry cell weight per root

Antiproliferative effect of D-glucuronyl C5-epimerase in human breast cancer cells

<p>Abstract</p> <p>Background</p> <p>D-glucuronyl C5-epimerase (GLCE) is one of the key enzymes in the biosynthesis of heparansulfate proteoglycans. Down-regulation of <it>GLCE </it>expression in human breast tumours suggests a possible involvement of the gene in carcinogenesis. In this study, an effect of <it>GLCE </it>ectopic expression on cell proliferation and viability of breast carcinoma cells MCF7 <it>in vitro </it>and its potential molecular mechanisms were investigated.</p> <p>Results</p> <p><it>D-glucuronyl C5-epimerase </it>expression was significantly decreased in MCF7 cells compared to normal human breast tissue. Re-expression of <it>GLCE </it>inhibited proliferative activity of MCF7 cells according to CyQUANT NF Cell Proliferation Assay, while it did not affect their viability in Colony Formation Test. According to Cancer PathFinder RT Profiler PCR Array, antiproliferative effect of <it>GLCE </it>in <it>vitro </it>could be related to the enhanced expression of tumour suppressor genes р53 (+3.3 fold), E2F1 (+3.00 fold), BRCA1 (+3.5 fold), SYK (+8.1 fold) and apoptosis-related genes BCL2 (+4.2 fold) and NFKB1 (+2.6 fold). Also, <it>GLCE </it>re-expression in MCF7 cells considerably changed the expression of some genes involved in angiogenesis (IL8, +4.6 fold; IFNB1, +3.9 fold; TNF, +4.6 fold and TGFB1, -5.7 fold) and invasion/metastasis (SYK, +8.1 fold; NME1, +3.96 fold; S100A4, -4.6 fold).</p> <p>Conclusions</p> <p>The ability of <it>D-glucuronyl С5-epimerase </it>to suppress proliferation of breast cancer cells MCF7 through the attenuated expression of different key genes involved in cell cycle regulation, angiogenesis and metastasis molecular pathways supports the idea on the involvement of the gene in regulation of breast cancer cell proliferation.</p

Defining the probability of bank debtors’ default using financial solvency assessment models

Due implementation of debtors’ financial solvency assessment models by Ukrainian banks with the aim of calculating the probability of their default (PD) is the next step towards the integration of Ukrainian banking system into global banking community, convergence of methodical approaches to assessing the credit risk with standards of international practice, possibility of using IRB-approach (an approach based on internal ratings) for calculating the regulatory requirements to capital adequacy.The analysis of approaches to bank credit portfolio segmentation according to types of debtors and debtors’ financial solvency assessment models, depending on the performed segmentation and accumulated bank statistical data, from the point of view of its suitability for Ukrainian banks, will enable the banks to choose the most suitable ones for implementation taking into account nature and complexity of operations performed.Such approaches will be more adapted to minimum capital requirements, simultaneously agreeing with national supervisory priorities

μ-Oxalato-bis­[(2,2′-bipyridyl)­copper(II)] bis(perchlorate) dimethyl­formamide disolvate monohydrate

The title compound, [Cu2(C2O4)(C10H8N2)4](ClO4)2·2C3H7NO·H2O, contains doubly charged centrosymmetric dinuclear oxalato-bridged copper(II) complex cations, perchlorate anions, and DMF and water solvate mol­ecules. In the complex cation, the oxalate ligand is coordinated in a bis-bidentate bridging mode to the Cu atoms. Each Cu atom has a distorted tetra­gonal-bipyramidal environment, being coordinated by two N atoms of the two chelating bipy ligands and two O atoms of the doubly deprotonated oxalate anion. Pairs of perchlorate anions and water mol­ecules are linked into recta­ngles by O—H⋯O bonds in which the perchlorate O atoms act as acceptors and the water mol­ecules as donors. Methyl groups of the DMF solvent molecule are disordered over two sites with occupancies of 0.453 (7):0.547 (7), and the water molecule is half-occupied

Characteristics of antibiotic resistance of non-typhoidal Salmonella circulating in the Russian Federation in the period from 2019 to 2022

Introduction. Non-typhoidal Salmonella make a significant contribution to the incidence of enteric infections and are characterized by an increasing proportion of strains resistant to antimicrobial agents (AMA), including the first choice antibiotics (cephalosporins III and fluoroquinolones). The purpose of the study is to assess the phenotypic resistance of Salmonella to various classes of AMAs and determine the relationship between the phenotypic resistance, serotype, source of isolation and nature of incidence. Materials and methods. We studied 752 representative strains of Salmonella of 2494 strains isolated from various sources (clinical samples, food products, environment) received from 59 regions of Russia in the period from 2019 to 2022. The phenotypic resistance to 22 antibiotics of 11 CLSI classes of AMAs was assessed by broth microdilution method (minimum inhibitory concentration). The diversity of resistance profiles of Salmonella serotypes was compared using the Shannon index. Results. The dominant position in terms of isolation frequency is occupied by the serotypes Salmonella Enteritidis, S. Infantis, S. Muenchen, S. Typhimurium, S. Bovismorbificans, which accounted for 64.4% of the studied strains. 543 (72.2%) strains showed resistance to at least one of the tested antibiotics; 193 (25.7%) strains were characterized by multidrug resistance phenotype (MDR). Resistance to AMA classes was characterized by the following distribution: quinolones (61.3%), tetracyclines (28.1%), penicillins (19.1%), β-lactam combination agents (18.6%), folate pathway antagonists (16, 5%), phenicols (10.1%), aminoglycosides (5.6%), cephems (4.7%), monobactams (4.4%), lipopeptides (3.9%). No penem-resistant strains have been identified. The features of Salmonella resistance by AMA classes are shown to depend on the sources of isolation, the Salmonella serotype and the nature of the incidence (outbreak and sporadic). Conclusions. Monitoring of phenotypic antibiotic resistance is an important tool for epidemiological surveillance in order to prevent the spread of bacterial resistance to AMAs

Characterization of cerebral blood flow dynamics with multiscale entropy

Based on the laser speckle contrast imaging (LSCI) and the multiscale entropy (MSE), we study in this work the blood flow dynamics at the levels of cerebral veins and the surrounding network of microcerebral vessels. We discuss how the phenylephrine-related acute peripheral hypertension is reflected in the cerebral circulation and show that the observed changes are scale-dependent, and they are significantly more pronounced in microcerebral vessels, while the macrocerebral dynamics does not demonstrate authentic inter-group distinctions. We also consider the permeability of blood–brain barrier (BBB) and study its opening caused by sound exposure. We show that alterations associated with the BBB opening can be revealed by the analysis of blood flow at the level of macrocerebral vessels

The rs738409 (I148M) Variant of the PNPLA3 Gene and Type 2 Diabetes in Yakutia

The purpose of our research was to study the association of the PNPLA3 SNP rs738409 (C>G) with type 2 diabetes (T2D) in the Yakuts. The frequency distribution of alleles and genotypes of the PNPLA3 rs738409 SNP was in accordance with HWE. There were no statistically significant differences in the distribution of alleles and genotypes of the PNPLA3 SNP rs738409 (C>G) between T2D patients and non-T2D patients (P>0.05); the G allele and homozygous GG genotype prevailed in both groups. In T2D patients, a high frequency of the G allele (74.1%) was found, with a predominance of the GG genotype (58.5%). We also found that the mutant allele frequency is higher than in the studied populations of the world. Further studies with larger sample size are required to achieve sufficient statistical power to detect the association of the PNPLA3 SNP (rs738409 with the development of T2D in Yakut patients

Materials of scientific and practical conference «Dietoogy In Practice Of Endocrinologist» at the VIII (XXV) Russian Diabetology Congress With International Participation «Diabetes Mellitus – XXIth Century Pandemia»

The scientific-practical conference Dietoogy In Practice Of Endocrinologist was held during the VIII Russian diabetology congress with international participation &ldquo;Diabetes Mellitus &ndash; XXIth Century Pandemia&rdquo;. It was chaired by Academician of RAS M.V. Shestakova (Moscow), Professors L.A. Ruyatkina (Novosibirsk ) and L.A. Suplotova (Tyumen). The expediency of this event was dictated by the necessity to create a unified national regulated guidelines for the diet therapy of obesity and associated diseases for the medical community and patients. The program of the meeting included a discussion about the formation of a healthy diet and its effect on the body, starting from the pregnant women, fetal development, the breastfeeding period, in the period of perimenopause and postmenopause, in the presence of concomitant pathology of heart and kidneys