On the evolution of compact binary black holes

Based on the consideration of potential energy of the di-black-hole as a function of mass asymmetry (transfer) collective coordinate, the possibility of matter transfer between the black holes in a binary system is investigated. The sensitivity of the calculated results is studied to the value of the total mass of binary system. The conditions for the merger of two black holes are analyzed in the context of gravitational wave emission.

NUMERICAL RESEARCH OF THE CHANGE OF REGIME FOR UNSTABLE MASS TRANSFER IN A TERNARY GAS MIXTURE HYDROGEN- NITRIC OXIDE-NITROGEN

On the basis of the software package "MathCad", by solving the Stefan-Maxwell diffusion equations, the evolution of the features of mass transfer in a three-component gas mixture, depending on pressure changes, has been numerically studied. In this analysis, the mixing process is studied in a vertical cylindrical channel of a finite size and at the isothermal conditions. The governing equations are solved at the boundary conditions assuming the absence of matter transfer through the walls of diffusion channel. Through the Rayleigh partial numbers, the influence of the pressure change on the behaviour of diffusion and convective flows is examined. The numerical results reveal that an increase in the pressure leads to a change of modes in ternary gas mixture. The present results are in good agreement with the existing experimental data.

Gut Pathology and Its Rescue by ACE2 (Angiotensin-Converting Enzyme 2) in Hypoxia-Induced Pulmonary Hypertension

Therapeutic advances for pulmonary hypertension (PH) have been incremental because of the focus on the pulmonary vasculature in PH pathology. Here, we evaluate the concept that PH is, rather, a systemic disorder involving interplay among multiorgan systems, including brain, gut, and lungs. Therefore, the objective of this study was to evaluate the hypothesis that PH is associated with a dysfunctional brain-gut-lung axis and that global overexpression of ACE2 (angiotensin-converting enzyme 2) rebalances this axis and protects against PH. ACE2 knockin and wild-type (WT; C57BL/6) mice were subjected to chronic hypoxia (10% FIO2) or room air for 4 weeks. Cardiopulmonary hemodynamics, histology, immunohistochemistry, and fecal 16S rRNA microbial gene analyses were evaluated. Hypoxia significantly increased right ventricular systolic pressure, sympathetic activity as well as the number and activation of microglia in the paraventricular nucleus of the hypothalamus in WT mice. This was associated with a significant increase in muscularis layer thickening and decreases in both villi length and goblet cells and altered gut microbiota. Global overexpression of ACE2 prevented changes in hypoxia-induced pulmonary and gut pathophysiology and established distinct microbial communities from WT hypoxia mice. Furthermore, WT mice subjected to fecal matter transfer from ACE2 knockin mice were resistant to hypoxia-induced PH compared with their controls receiving WT fecal matter transfer. These observations demonstrate that ACE2 ameliorates these hypoxia-induced pathologies and attenuates PH. The data implicate dysfunctional brain-gut-lung communication in PH and provide novel avenues for therapeutic interventions.

Seasonal dynamics in fish and squid trophic status in the pelagic Sea of Okhotsk, based on d13C and d15N stable isotope data analysis

Seasonal trophic dynamics was analyzed based on d13C and d15N stable isotope mass content in the Sea of Okhotsk 35 nekton species (fish and squid (Teuthida)). It was shown that considerable differences between species in stable isotope mass contents were associated with diet type. The d15N average values of the Sea of Okhotsk species were 4.5 ‰ in spring, 7.5 ‰ in summer, and 5.4 ‰ in autumn. The summer increase was caused by the appearance of juvenile fish and squid with low trophic status and minimal d15N values, and the autumn decline was due increased trophic status of growing up young individuals. Variability range in d15N values was 11.5 ‰ for all nekton species in summer including migrants into the Sea of Okhotsk from the Pacific Ocean. Relatively narrow variability range in d13C for nekton species, of 2.2–3.3 ‰, reflects seasonal homogeneity in the trophic web basement in the pelagic Sea of Okhotsk. The structure of the food web of the pelagic nekton, presented according to the d15N and d13C data, provides useful information on the pathways of organic matter transfer to the pelagic zone at the upper trophic levels and can be further used to construct trophodynamic models of the Sea of Okhotsk.

Adequateness assessement of percolate and temperature model using MSU Large lysimeters

The assessement of PEARL model adequateness was carried out on the basis of temperature and percolate data obtained by means of MSU Large Lysimeters. Lysimeters are used in experimental soil science mostly for investigating water balance and substance or ions transport from observed horizons or full soil profile. PEARL 4 model, the water prediction block of which is built on the basis of classical SWAP model, uses preferential water flow describing mechanism. Systematical observation of experimental soils in MSU Large lysimeters allowed obtaining extensive data on temperature and soil moisture dynamics, as well as percolate from bottom border. Thеsе measurements are unique and can become the basis for adaptation, verification and setting of mass and energy transfer models. It was shown, that mathematical parametric model requires adjustment for reaching reliable values of percolate from bottom border, moisture and temperature profiles. It can be achieved by selection of water retention curve (WTC) approximation parameters. It was noticed that the error for all predicted parameters increases in winter period. Thereby, the use of such matter transfer models in soil are problematic for long-term prognosis. For example, due to the annual error accumulation before the spring season such models cannot be applied for estimation of the risk of ground water pollution with agrochemicals.

Entropy Density Acceleration and Minimum Dissipation Principle: Correlation with Heat and Matter Transfer in Glucose Catabolism

The heat and matter transfer during glucose catabolism in living systems and their relation with entropy production are a challenging subject of the classical thermodynamics applied to biology. In this respect, an analogy between mechanics and thermodynamics has been performed via the definition of the entropy density acceleration expressed by the time derivative of the rate of entropy density and related to heat and matter transfer in minimum living systems. Cells are regarded as open thermodynamic systems that exchange heat and matter resulting from irreversible processes with the intercellular environment. Prigogine’s minimum energy dissipation principle is reformulated using the notion of entropy density acceleration applied to glucose catabolism. It is shown that, for out-of-equilibrium states, the calculated entropy density acceleration for a single cell is finite and negative and approaches as a function of time a zero value at global thermodynamic equilibrium for heat and matter transfer independently of the cell type and the metabolic pathway. These results could be important for a deeper understanding of entropy generation and its correlation with heat transfer in cell biology with special regard to glucose catabolism representing the prototype of irreversible reactions and a crucial metabolic pathway in stem cells and cancer stem cells.

Entropy Density Acceleration and Minimum Dissipation Principle: Correlation with Heat and Matter Transfer in Glucose Catabolism

The heat and matter transfer during glucose catabolism in living systems and their relation with entropy production are a challenging subject of the classical thermodynamics applied to biology. In this respect, an analogy between mechanics and thermodynamics has been performed via the definition of the entropy density acceleration expressed by the time derivative of the rate of entropy density and related to heat and matter transfer in minimum living systems. Cells are regarded as open thermodynamic systems that exchange heat and matter resulting from irreversible processes with the intercellular environment. Prigogine’s minimum energy dissipation principle is reformulated using the notion of entropy density acceleration applied to glucose catabolism. It is shown that, for out-of-equilibrium states, the calculated entropy density acceleration is finite and negative and approaches as a function of time a zero value at global thermodynamic equilibrium for heat and matter transfer independently of the cell type and the metabolic pathway. These results could be important for a deeper understanding of entropy generation and its correlation with heat transfer in cell biology with special regard to glucose catabolism representing the prototype of irreversible reactions and a crucial metabolic pathway in stem cells and cancer stem cells.

Magnetic steering of liquid metal mobiles

In this study, we proposed a magnetic actuation scenario for steering liquid metal locomotion in an easily accessible and highly directed manner. And it could have potential applications in flexible electronics, matter transfer, as well as vessel cleaning.