A Model of Optimal Network Structure for Decentralized Nearest Neighbor Search

One of the approaches for the nearest neighbor search problem is to build a network which nodes correspond to the given set of indexed objects. In this case the search of the closest object can be thought as a search of a node in a network. A procedure in a network is called decentralized if it uses only local information about visited nodes and its neighbors. Networks, which structure allows efficient performing the nearest neighbour search by a decentralised search procedure started from any node, are of particular interest especially for pure distributed systems. Several algorithms that construct such networks have been proposed in literature. However, the following questions arise: "Are there network models in which decentralised search can be performed faster?"; "What are the optimal networks for the decentralised search?"; "What are their properties?". In this paper we partially give answers to these questions. We propose a mathematical programming model for the problem of determining an optimal network structure for decentralized nearest neighbor search. We have found an exact solution for a regular lattice of size 4x4 and heuristic solutions for sizes from 5x5 to 7x7. As a distance function we use L1 , L2 and L_inf metrics. We hope that our results and the proposed model will initiate study of optimal network structures for decentralised nearest neighbour search

Isoflurane Anesthesia Initiated at the Onset of Reperfusion Attenuates Oxidative and Hypoxic-Ischemic Brain Injury

This study demonstrates that in mice subjected to hypoxia-ischemia (HI) brain injury isoflurane anesthesia initiated upon reperfusion limits a release of mitochondrial oxidative radicals by inhibiting a recovery of complex-I dependent mitochondrial respiration. This significantly attenuates an oxidative stress and reduces the extent of HI brain injury. Neonatal mice were subjected to HI, and at the initiation of reperfusion were exposed to isoflurane with or without mechanical ventilation. At the end of HI and isoflurane exposure cerebral mitochondrial respiration, H₂O₂ emission rates were measured followed by an assessment of cerebral oxidative damage and infarct volumes. At 8 weeks after HI navigational memory and brain atrophy were assessed. In vitro, direct effect of isoflurane on mitochondrial H₂O₂ emission was compared to that of complex-I inhibitor, rotenone. Compared to controls, 15 minutes of isoflurane anesthesia inhibited recovery of the compex I-dependent mitochondrial respiration and decreased H₂O₂ production in mitochondria supported with succinate. This was associated with reduced oxidative brain injury, superior navigational memory and decreased cerebral atrophy compared to the vehicle-treated HI-mice. Extended isoflurane anesthesia was associated with sluggish recovery of cerebral blood flow (CBF) and the neuroprotection was lost. However, when isoflurane anesthesia was supported with mechanical ventilation the CBF recovery improved, the event associated with further reduction of infarct volume compared to HI-mice exposed to isoflurane without respiratory support. Thus, in neonatal mice brief isoflurane anesthesia initiated at the onset of reperfusion limits mitochondrial release of oxidative radicals and attenuates an oxidative stress. This novel mechanism contributes to neuroprotective action of isoflurane. The use of mechanical ventilation during isoflurane anesthesia counterbalances negative effect of isoflurane anesthesia on recovery of cerebral circulation which potentiates protection against reperfusion injury

A new platform for high-throughput therapy testing on iPSC-derived lung progenitor cells from cystic fibrosis patients

For those people with cystic fibrosis carrying rare CFTR mutations not responding to currently available therapies, there is an unmet need for relevant tissue models for therapy development. Here, we describe a new testing platform that employs patient-specific induced pluripotent stem cells (iPSCs) differentiated to lung progenitor cells that can be studied using a dynamic, high-throughput fluorescence-based assay of CFTR channel activity. Our proof-of-concept studies support the potential use of this platform, together with a Canadian bioresource that contains iPSC lines and matched nasal cultures from people with rare mutations, to advance patient-oriented therapy development. Interventions identified in the high-throughput, stem cell-based model and validated in primary nasal cultures from the same person have the potential to be advanced as therapies

Means of Ukrainian scientific language

1. Муромцева І. В. Українська мова : енциклопедія. Київ: Видавництво «Майстер-клас», 2011. 400 с. 2. Пономарів О. Д. Стилістика сучасної української мови. Тернопіль : Богдан, 2000. 248 с.3. Сіроштан Т. В. Абстрактні іменники в словотвірній системі сучасної української мови (на матеріалі «малої прози» початку XXI століття). Науковий вісник Міжнародного гуманітарного університету. Серія : Філологія, 2016. Вип. 20 (1). С. 42–44.Методологія науки розглядає мову як засіб вираження фіксації, переробки, передачі та зберігання наукових знань. Кожен стиль характеризується певною властивою йому системою мовних засобів і стилістичними нормами. У цілому мовий стиль визначається як сукупність засобів, вибір яких зумовлюється змістом, метою та характером висловлювання.The methodology of science considers language as a means of expressing the recording, processing, transmission and storage of scientific knowledge. Each style is characterised by a specific system of linguistic means and stylistic norms. In general, the language style is defined as a set of means, the choice of which is determined by the content, purpose and nature of the statement

7th International Conference in Network Analysis

Contributions in this volume focus on computationally efficient algorithms and rigorous mathematical theories for analyzing large-scale networks. Researchers and students in mathematics, economics, statistics, computer science and engineering will find this collection a valuable resource filled with the latest research in network analysis. Computational aspects and applications of large-scale networks in market models, neural networks, social networks, power transmission grids, maximum clique problem, telecommunication networks, and complexity graphs are included with new tools for efficient network analysis of large-scale networks. This proceeding is a result of the 7th International Conference in Network Analysis, held at the Higher School of Economics, Nizhny Novgorod in June 2017. The conference brought together scientists, engineers, and researchers from academia, industry, and government

Analytical tools for ensuring economic security in the conditions of global competitiveness: theoretical aspect

Global competitiveness, based on the international division of labor, the use of factors of production and the country’s place in the world market ensures the ability of the state to participate in the competition and the full use of its own competitive advantages. Globalization processes have negative consequences for functioning of national economies, which actualizes the problem of ensuring the economic security of countries. The economic security of the state is the criterion of the effectiveness of the state economic policy and characterizes the overall level of the country’s economy; the presence and level of threats to the state, society or person; the effectiveness of state regulation of the economy; the full implementation of the functions of the state. At the same time, its analytical tools are based on the most important parameters of the state of the economic system, its stability and mobility: GDP growth, the level and quality of life of the majority of the population, inflation, unemployment, the structure of the economy, the property stratification of the population, criminalization and shadowing of the economy, the state of the technical and technological base of the economy, spending on research, import dependence, economic openness, internal and external debt

RADON-222 DISTRIBUTION IN THE SOILS OF THE FLOODPLAIN AND FLUVIAL TERRACES ABOVE FLOODPLAIN OF THE IRTYSH AND TOBOL RIVERS

The relevance of the obtained data on distribution in the soils of the natural radionuclide – radon-222, which contributes to the key radiation load for lung cancer development, are relevant as regional indicators for the Tyumen region in assessing the potential radon danger of soils. The main aim of the research is to consider interrelation of physical parameters of soil (temperature, depth) and atmospheric air (temperature, humidity, pressure) with radon-222 flux density in soil, to define potentially radon dangerous sections of soils in flood plains and above flood plain terraces of the Irtysh and Tobol rivers. Objects: radon-222 flux density in soils of floodplains and above floodplain terraces of the Irtysh and Tobol rivers within Tobolsk, Vagaysk and partially Yarkovo districts of the Tyumen region of the Russian Federation. Methods. Radon-222 density in soil was measured by passive sorption of radon-222 on activated carbon with further measurement of activity of sorbed radon-222 in laboratory conditions by means of complex «Camera-01». Radon-222 activity in coal was measured by β-radiation of short-lived decay products of radon – lead-214 and bismuth-214 which are in radioactive equilibrium with radon-222 sorbed in coal. Results. The paper introduces the data (2018–2021) on radon-222 flux density distribution in soils of floodplains and fluvial terraces above floodplain of the Irtysh and Tobol rivers within the boundaries of Tobolsk, Vagaysk and partially Yarkovsky districts of the Tyumen Region of the Russian Federation. Radon-222 flux density from the soil surface does not exceed 80 mBq/(m2·s) in 73 out of 76 investigated plots of soils, located in the floodplain and fluvial terraces above floodplain of the Irtysh and Tobol rivers which corresponds to the first radon hazard class according to Basic Sanitary Rules for Radiation Safety (BSRERS 99/2010), approved in the Russian Federation. The surface of the soils of these sites is not potentially dangerous. Radon-222 flux density at soil depth of 0,4–1,0 m averages 109,3…495 mBq/(m2·s), maximum values vary within the limits of 1085...1280 mBq/(m2·s). The reliable influence of soil depth on distribution of radon-222 flux density was detected – radon-222 concentration decreases from the depth to the soil surface. Radon-222 flux density does not depend on insignificant variations in atmospheric pressure, no statistically significant relations with temperature and atmospheric air humidity were established. The average values of radon-222 flux density in soil in summer (August) and autumn (September) months increased nearly twice as much as in spring (May)

Effects of Sponge-Derived Alkaloids on Activities of the Bacterial α-D-Galactosidase and Human Cancer Cell α-N-Acetylgalactosaminidase

During a search for glycosidase inhibitors among marine natural products, we applied an integrated in vitro and in silico approach to evaluate the potency of some aaptamines and makaluvamines isolated from marine sponges on the hydrolyzing activity of α-N-acetylgalactosaminidase (α-NaGalase) from human cancer cells and the recombinant α-D-galactosidase (α-PsGal) from a marine bacterium Pseudoalteromonas sp. KMM 701. These alkaloids showed no direct inhibitory effect on the cancer α-NaGalase; but isoaaptamine (2), 9-demethylaaptamine (3), damirone B (6), and makaluvamine H (7) reduced the expression of the enzyme in the human colorectal adenocarcinoma cell line DLD-1 at 5 μM. Isoaaptamine (2), 9-demethylaaptamine (3), makaluvamine G (6), and zyzzyanone A (7) are slow-binding irreversible inhibitors of the bacterial α-PsGal with the inactivation rate constants (kinact) 0.12 min−1, 0.092 min−1, 0.079 min−1, and 0.037 min−1, as well as equilibrium inhibition constants (Ki) 2.70 µM, 300 µM, 411 µM, and 105 µM, respectively. Docking analysis revealed that these alkaloids bind in a pocket close to the catalytic amino acid residues Asp451 and Asp516 and form complexes, due to π-π interactions with the Trp308 residue and hydrogen bonds with the Lys449 residue. None of the studied alkaloids formed complexes with the active site of the human α-NaGalase