Vol 488, No 2 (2019)

In the paper we discuss a new bound of the total variation distance in terms of L² distance for random variables that are polynominals in log-concave random vectors.

The paper proves (assuming the continuum hypothesis CH) that there exists a perfectly normal compact topological space Z and a countable set E ⊂ Z, such that Z\E is not condensed onto a compact. The existence of such a space answers (in CH) negatively to the question of V.I. Ponomareva: Is every perfectly normal compact an α-space? It is proved that in the class of ordered compacts the property of being an α-space is not multiplicative.

The static bending and longitudinal stability of nanowires under liquid or gas pressure are considered. Two surface effects are taken into account. The first is due to the difference in elastic properties in the thin surface layer and in the bulk of the material. Effective tensile and flexural stiffness can be more or less than conventional stiffness, depending on the material. The second effect is due to the interaction of excess pressure on the circular side surface of the wire and the difference of the areas of the convex and concave sides of the surface that appears during bending. This effect is manifested the stronger, the greater the ratio of pressure to the modulus of elasticity of the material and the length of the wire to its diameter. These effects are determined by dimensionless parameters. It has been established that a loss of wire stability may occur under the influence of the second effect. A possible method for determining the dimensionless parameter, which determines the differences of elastic properties in a thin layer near the surface and the base material, is proposed.

Results of experiments in low-turbulence subsonic wind tunnel sustaining the possibility of significant attenuation of the cross-flow velocity and the intensity of stationary instability vortices due to the body force impact on three-dimensional boundary layer are presented. The unidirectional body force over a significant area of the streamlined surface has been created with the help of dielectric barrier discharge actuator.

The paper presents the experimental results of possibility obtaining ultra-high temperature composite Ta₄ZrC₅ using a single-stage method. The method is based on the use of exothermic synthesis of refractory compounds by electro-thermal explosion (ETE) and their consolidation under conditions of quasi-isostatic compression. The effect of mechanical activation of the reaction mixture of tantalum, zirconium and carbon powders on the formation of the phase composition of the ceramic composite Ta₄ZrC₅ was studied. The conditions for obtaining a single-phase ultra-high temperature composites had were determined. The composites were prepared with the average particle size of 1-2 µm and a residual porosity of 8-10%.

A kinetic model describing the impulse of increasing oxygen in the excited nervous tissue of the human brain in response to an external signal is presented. The model is based on biochemical data and describes experimental data on an impulsed hemodynamic response. The model predicts the dynamic behavior of the process participants, which preceding the oxygen impulse and determining the level of the BOLD-signal.

The obtained original materials, in conjunction with the literature data (hydrochemical contrasting halos), make it possible to predict a new (Tarakonsky) gold ore field within the eastern part of the Argun superterrane. Industrial concentrations of gold are noted in quartz metasomatites from granites and limestones. The amount of ore minerals usually does not exceed 5-10%. They are present in the rocks in micron and submicron size, represented mainly by pyrite, less often galena, sphalerite, chalcopyrite, ilmenite, hematite, magnetite, faded ores, and native high-grade gold. It is assumed that the formation of the Tarakonsky gold ore field, as well as most of the ore objects in the region, is associated with the manifestation of Late Mesozoic magmatism.

The isotope composition of the natural waters of the Eastern Transbaikalia is studied. It is established that the water of the soda lakes is more enriched with oxygen-18, but in smaller - with deuterium. It is shown that the enrichment of the waters of salt lakes with heavy isotopes is due not only to the evaporation process, but to the interaction of water with the rock. The participation of the reactions of hydrolysis of alumosilicates in the fractionation of oxygen is confirmed by the direct dependence of the magnitude of the oxygen shift on pH, the value of which depends on the degree of such interaction.

This study presents the first data set of sulfurisotope compositions of primary Ru-Os sulfides, represented by laurite (RuS₂) - erlichmanite (OsS₂) series, within a primary platinum-group mineral (PGM) assemblage derived from the Verkh-Neivinsky dunite-harzburgite massif, a typical example of the mantle ophiolite association at the Middle Urals. The S-isotope signatures of Ru-Os sulfides studied are consistent with derivation of the ore material from a mantle source for Ru-Os sulfides.

Saltating particle aleurite mode is discovered in the windsand flux over desertified area. Approximation of the saltating particle distribution measured is received using two lognormal distribution functions. It is shown that aleurite and sand number concentration particles in the windsand flux depends on wind velocity in the surface layer in different way.

The article considers the geography of emerging and re-emerging natural focal diseases in Russia. The data on the distribution and peculiarities of epidemic manifestations of eight key infections (ixodid tick-borne borrelioses, tick-borne encephalitis, hemorrhagic fever with renal syndrome, tularemia, leptospirosis, West Nile fever, Crimean-Congo hemorrhagic fever and Astrakhan rickettsiosis fever) belonging to different groups of emerging and re-emerging diseases are presented. We estimated and mapped the risk of exposure to these infections in the European territory of Russia within natural borders (biomes).

Analytical expressions of the hydrodynamic reaction of a point dipole in two-layer circulatory fluid flow around it are obtained. The dependence of the wave resistance and the lift force on the flow velocity, the density jump, the circulation and the depth of the sea is investigated. It is shown that the influence of the velocity circulation leads to a change in the lift force acting on the dipole. Moreover, such changes are reversible in a relatively narrow range of the velocity of flow around the pipeline. Along with the pipeline, such features in the nature of the effect of circulation on the lift force can be manifested for self-propelled underwater objects and aerial vehicles.

The search of potential partners of human SELM in lysates of two cancer cell lines HT-1080 (fibrosarcoma) and MCF-7 (breast adenocarcinoma) was carried out. Two cytoplasmic actin isoforms: cytoplasmic actin 1 (cytoskeleton b-actin) and cytoplasmic actin 2 (cytoskeletal g-actin) was identified as partners. In addition, the influence of two widely used antitumor selenium compounds (sodium selenite and methylseleninic acid) on the expression SELM in cancer cells was studied. According to the results obtained by real-time PCR and Western blotting, we was concluded that 1 µM and 10 µM sodium selenite was not affected on the expression SELM in fibrosarcoma cells, whereas in breast adenocarcinoma cells 1 µM sodium selenite slightly increased of expression and 10 µM resulted in a significant decrease (about 2 times). Methylseleninic acid in both cancer cell lines increased the expression of SELM gene, the most pronounced effect was observed when fibrosarcoma cells were treated with 10 µM MSC (increased expression of the hSelm gene by almost 4 times).

Using Fura-2AM microfluorimetry we have shown for the first time that sigma-1 receptor agonist - tricyclic antidepressant amitriptyline - significantly inhibits store-dependent Ca²⁺ entry, induced by endoplasmic Ca²⁺-ATPase inhibitors thapsigargin and cyclopiazonic acid, in rat peritoneal macrophages. The results suggest possible involvement of sigma-1 receptors in the regulation of store-dependent Ca²⁺ entry in macrophages.