The 42nd International S.B. Stechkin’s Workshop-Conference on Function Theory

The paper is devoted to the description of the history and results of the 42nd International S.B.Stechkin's Workshop on function theory, held in August 2017 in the Ilmen Nature Reserve near the town of Miass, Chelyabinsk region

Mapping Problems of Geophysical Fields in Ocean and Extremum Problems of Underwater Objects Navigation

The paper focuses on mathematical and technical problems of navigation and control of unmanned underwater vehicles (AUV). Such problems arise during geophysical fields mapping, development of map-aided navigation methods, and optimal routes finding. To address map creation problem, the results of measurements on trajectory were used; then the field map reconstruction in fixed frame of a reference followed. The paper discusses optimization of the survey routes and optimization of measurements of the parameters of local fields and their anomalies on trajectory of an AUV. The field map reconstruction methods based on measurement results on trajectory are considered. Some mathematical problems of navigation by geophysical field maps are discussed. More specifically, matching algorithms for fragment taken in motion with a reference map are studied, the problem of the best reference map approximation for data compression on the AUV board is considered, the field informativity criterion is offered, and the problem of optimal route construction on the basis of such criterion is solved. The estimates obtained in the paper are based on theoretical studies, the results of simulation experiments, and field experimental trials of the AUV systems. © 201

Assessment of technological capabilities to counter fraudulent practices in the banking sector

In connection with the strengthening of Western sanctions on the Russian banking sector, the number of malefactors, who enjoy the confidence of panicking depositors and the unstable situation in the banking market, has increased dramatically. The article discusses the key issues of the application of big data analysis as a technological basis for countering fraud in the practical activities of banks. The objectives of such a struggle are to determine the operations of intruders in the flow of large volumes of statistical information with the greatest accuracy and to take preventive measures to minimize damage. The purpose of the article is to assess the possibility of using machine learning technology by banks and develop an algorithm for detecting fraudulent transactions based on programming. Particular attention is paid to the current economic environment, its impact on the financial system as a whole, and in particular, on the reorientation of the banking sector to combat fraud in the context of increased fraud activity

O международной школе-конференции по теории функций, посвященной 100-летию со дня рождения С. Б. Стечкина

The paper provides an overview of the main events of the International Workshop–Conference on Function Theory dedicated to the Centenary of the birth of S. B. Stechkin, which was held in Yekaterinburg online from August 3 to August 12, 2020, for the 45th time since 1971. A description of the traditions and peculiarities of such workshops that have developed over the years as well as a list of reports by the conference participants are given. The paper also contains memoirs about Sergei Borisovich Stechkin, the initiator of such workshops–conferences, the founder and head of the scientific school on function theory. © 2020 Krasovskii Institute of Mathematics and Mechanics. All rights reserved

Информация о смерти клеток необходима для жизни всего организма

In present paper we give the review of own experimental and literary data, devoted to programmed cells destruction— apoptosis in animal and plants. We show, that the inheritable information about cell death is necessary for life and evolutionary prosperity of multicellular organisms.В настоящей статье мы даем обзор собственных экспериментальных и литературных данных, посвященных запрограммированной гибели клеток — апоптозу у животных и растений, показываем, что наследственная информация о смерти необходима для жизни и эволюционного процветания многоклеточных организмов. За эти работы группе американских и английских учёных в 2002 г. была присуждена Нобелевская премия по физиологии и медицине. Апоптоз — центральная проблема современного комплекса наук о жизни

Stimulation of sphingosine 1-phosphate signaling as an alveolar cell survival strategy in emphysema

RATIONALE: Vascular endothelial growth factor receptor (VEGFR) inhibition increases ceramides in lung structural cells of the alveolus, initiating apoptosis and alveolar destruction morphologically resembling emphysema. The effects of increased endogenous ceramides could be offset by sphingosine 1-phosphate (S1P), a prosurvival by-product of ceramide metabolism. OBJECTIVES: The aims of our work were to investigate the sphingosine-S1P-S1P receptor axis in the VEGFR inhibition model of emphysema and to determine whether stimulation of S1P signaling is sufficient to functionally antagonize alveolar space enlargement. METHODS: Concurrent to VEGFR blockade in mice, S1P signaling augmentation was achieved via treatment with the S1P precursor sphingosine, S1P agonist FTY720, or S1P receptor-1 (S1PR1) agonist SEW2871. Outcomes included sphingosine kinase-1 RNA expression and activity, sphingolipid measurements by combined liquid chromatography-tandem mass spectrometry, immunoblotting for prosurvival signaling pathways, caspase-3 activity and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assays, and airspace morphometry. MEASUREMENTS AND MAIN RESULTS: Consistent with previously reported de novo activation of ceramide synthesis, VEGFR inhibition triggered increases in lung ceramides, dihydroceramides, and dihydrosphingosine, but did not alter sphingosine kinase activity or S1P levels. Administration of sphingosine decreased the ceramide-to-S1P ratio in the lung and inhibited alveolar space enlargement, along with activation of prosurvival signaling pathways and decreased lung parenchyma cell apoptosis. Sphingosine significantly opposed ceramide-induced apoptosis in cultured lung endothelial cells, but not epithelial cells. FTY720 or SEW2871 recapitulated the protective effects of sphingosine on airspace enlargement concomitant with attenuation of VEGFR inhibitor-induced lung apoptosis. CONCLUSIONS: Strategies aimed at augmenting the S1P-S1PR1 signaling may be effective in ameliorating the apoptotic mechanisms of emphysema development

Intracellular S1P Generation Is Essential for S1P-Induced Motility of Human Lung Endothelial Cells: Role of Sphingosine Kinase 1 and S1P Lyase

Earlier we have shown that extracellular sphingosine-1-phosphate (S1P) induces migration of human pulmonary artery endothelial cells (HPAECs) through the activation of S1P(1) receptor, PKCε, and PLD2-PKCζ-Rac1 signaling cascade. As endothelial cells generate intracellular S1P, here we have investigated the role of sphingosine kinases (SphKs) and S1P lyase (S1PL), that regulate intracellular S1P accumulation, in HPAEC motility

Evaluation of bioactive sphingolipids in 4-HPR-resistant leukemia cells

<p>Abstract</p> <p>Background</p> <p><it>N</it>-(4-hydroxyphenyl)retinamide (4-HPR, fenretinide) is a synthetic retinoid with potent pro-apoptotic activity against several types of cancer, but little is known regarding mechanisms leading to chemoresistance. Ceramide and, more recently, other sphingolipid species (e.g., dihydroceramide and dihydrosphingosine) have been implicated in 4-HPR-mediated tumor cell death. Because sphingolipid metabolism has been reported to be altered in drug-resistant tumor cells, we studied the implication of sphingolipids in acquired resistance to 4-HPR based on an acute lymphoblastic leukemia model.</p> <p>Methods</p> <p>CCRF-CEM cell lines resistant to 4-HPR were obtained by gradual selection. Endogenous sphingolipid profiles and in situ enzymatic activities were determined by LC/MS, and resistance to 4-HPR or to alternative treatments was measured using the XTT viability assay and annexin V-FITC/propidium iodide labeling.</p> <p>Results</p> <p>No major crossresistance was observed against other antitumoral compounds (i.e. paclitaxel, cisplatin, doxorubicin hydrochloride) or agents (i.e. ultra violet C, hydrogen peroxide) also described as sphingolipid modulators. CCRF-CEM cell lines resistant to 4-HPR exhibited a distinctive endogenous sphingolipid profile that correlated with inhibition of dihydroceramide desaturase. Cells maintained acquired resistance to 4-HPR after the removal of 4-HPR though the sphingolipid profile returned to control levels. On the other hand, combined treatment with sphingosine kinase inhibitors (unnatural (dihydro)sphingosines ((dh)Sph)) and glucosylceramide synthase inhibitor (PPMP) in the presence or absence of 4-HPR increased cellular (dh)Sph (but not ceramide) levels and were highly toxic for both parental and resistant cells.</p> <p>Conclusions</p> <p>In the leukemia model, acquired resistance to 4-HPR is selective and persists in the absence of sphingolipid profile alteration. Therapeutically, the data demonstrate that alternative sphingolipid-modulating antitumoral strategies are suitable for both 4-HPR-resistant and sensitive leukemia cells. Thus, whereas sphingolipids may not be critical for maintaining resistance to 4-HPR, manipulation of cytotoxic sphingolipids should be considered a viable approach for overcoming resistance.</p