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For last 30 years Russian science and education system has been experiencing constant, profound institutional transformation in order to increase the quality of education, it's access ability and with a point to encrease the effectiveness of science. This article is devoted to the attempt to analysis the results of undertaken reforms and evaluating the quality of economic institutions which coordinate the order of market agents of researching field. The analysis of narratives approach was chosen with the intention for estimating the quality of reforms undertaken. Narratives are defined to be stories in direct speech of actors themselves of researching field: professors, students, Master’s and graduated students of all forms of education, as soon as scientists and researchers of universities and research institutes and different levels of responsibility and competencies administrators. The "Integrum" database taken as the main source of information for searching for narratives. This informational base consists of 1250 Russian newspapers (federal and regional) and 500 journals which help us to select 250 narratives (stories in direct speech) of people who are directly involved in transformational process of education system and science being studied. The obtained results pointed out the number of stable ineffective rules and practices which have a negative impact on our researching area functioning and also made it possible to classify out a few groups of institutional traps such as: metric's trap, trap of raising level of bureacracy, trap of shortage of finansing, electronization and digitalization trap and trap of staff capacity. Each determined trap reflected in the article is also pointed out and argued with selected narratives.

We study a three-component universe filled with dust-like matter in the form of discrete inhomogeneities (e.g., galaxies) and perfect fluids characterized by linear and nonlinear equations of state. Within the cosmic screening approach, we develop the theory of scalar and vector perturbations. None of the energy density contrasts associated with the distinct components is treated as small. Consequently, the derived equations are valid at both sub- and super-horizon scales and enable simulations for a variety of cosmological models., Comment: 11 pages, no figures

Searching for possible indicators of spatial topology of the Universe in the Cosmic Microwave Background data, one recognizes a quite promising interpretation which suggests that the shape of the space manifests itself in the form of anomalies in the large angular scale observations, such as the quadrupole and octopole alignment. Motivated by the presumptive existence of such a tempting connection, we study the chimney topology, T×T×R, which belongs to the class of toroidal topologies with a preferred direction. The infinite axis in this case may be attributed to the preferred axis of the aforementioned quadrupole and octopole alignment. We investigate the gravitational aspects of such a configuration. Namely, we reveal the form of the gravitational potential sourced by point-like massive bodies. Starting from the perturbed Einstein equations, which ensure the proper demonstration of relativistic effects, one can derive the Helmholtz equation for the scalar perturbation (gravitational potential). Through distinct alternative methods, we present the physically meaningful nontrivial exact solutions of this equation. Our approach excludes any presumptions regarding the spatial distribution of gravitating sources. We show that the particular solution that appears in the form of summed Yukawa potentials is indeed very convenient for the use in numerical calculations, in the sense that it provides the desired accuracy with fewer terms in the series.

We study the effect of the slab topology $T\times R\times R$ of the Universe on the form of gravitational potentials and forces created by point-like masses. We obtain two alternative forms of solutions: one is based on the Fourier series expansion of the delta function using the periodical property along the toroidal dimension, and another one is derived by direct summation of solutions of the Helmholtz equation for the source particle and all its images. The latter one takes the form of the sum of Yukawa-type potentials. We demonstrate that for the present Universe the latter solution is preferable for numerical calculations since it requires less terms of the series to achieve the necessary precision., This is a preprint of an article published in the European Physical Journal Plus. The final authenticated version is available online at: https://doi.org/10.1140/epjp/s13360-021-01139-y

We investigate the influence of the chimney topology T×T×R of the Universe on the gravitational potential and force that are generated by point-like massive bodies. We obtain three distinct expressions for the solutions. One follows from Fourier expansion of delta functions into series using periodicity in two toroidal dimensions. The second one is the summation of solutions of the Helmholtz equation, for a source mass and its infinitely many images, which are in the form of Yukawa potentials. The third alternative solution for the potential is formulated via the Ewald sums method applied to Yukawa-type potentials. We show that, for the present Universe, the formulas involving plain summation of Yukawa potentials are preferable for computational purposes, as they require a smaller number of terms in the series to reach adequate precision.

We consider a universe filled with perfect fluid with the constant equation of state parameter $\omega$. In the theory of scalar perturbations, we study the effect of peculiar velocities on the gravitational potential. For radiation with $\omega=1/3$, we obtain the expression for the gravitational potential in the integral form. Numerical calculation clearly demonstrates the modulation of the gravitational potential by acoustic oscillations due to the presence of peculiar velocities. We also show that peculiar velocities affect the gravitational potential in the case of the frustrated network of cosmic strings with $\omega =-1/3$., Comment: 7 pages, 4 figures, references added, matches published version

An algorithm proposed for searching the topology of the ground-to-air radio network (GARN) to ensure the connectivity of ground nodes and improve the quality of their service. The search for a solution for the implementation of the target functions of network management is carried out by directed enumeration of options for the position of telecommunication aerial platforms (TA).

We study the effects associated with nonlinearity of $f(R)$ gravity and of the background perfect fluid manifested in the Kaluza-Klein model with spherical compactification. The background space-time is perturbed by a massive gravitating source which is pressureless in the external space but has an arbitrary equation of state (EoS) parameter in the internal space. As characteristics of a nonlinear perfect fluid, the squared speeds of sound are not equal to the background EoS parameters in the external and internal spaces. In this setting, we find exact solutions to the linearized Einstein equations for the perturbed metric coefficients. For nonlinear models with $f^{\prime\prime}(R_0)\neq0$, we show that these coefficients acquire correction terms in the form of two summed Yukawa potentials and that in the degenerated case, the solutions are reduced to a single Yukawa potential with some "corrupted" prefactor (in front of the exponential function), which, in addition to the standard $1/r$ term, contains a contribution independent of the three-dimensional distance $r$. In the linear $f''(R)=0$ model, we generalize the previous studies to the case of an arbitrary nonlinear perfect fluid. We also investigate the particular case of the nonlinear background perfect fluid with zero speed of sound in the external space and demonstrate that a non-trivial solution exists only in the case of $f''(R_0)=0$., Comment: v2 (matching the publication in European Physical Journal C) = v1 + minor changes + new Refs.; 14 pages, no figures

We investigate cosmological perturbations for nonlinear $f(R)$ models within the cosmic screening approach. Matter is considered both in the form of a set of discrete point-like massive bodies and in the form of a continuous pressureless perfect fluid. We perform full relativistic analysis of the first-order theory of scalar perturbations for arbitrary nonlinear $f(R)$ models and demonstrate that scalar potentials $\Phi(t,\mathbf{r})$ and $\Psi(t,\mathbf{r})$ are determined by a system of only two master equations. Our equations are applicable at all spatial scales as long as the approximation $\delta R/\bar R \ll 1$ (which is usually assumed in studies devoted to cosmological perturbations in $f(R)$ models) works., Comment: 7 pages, no figures and tables; matches the version published in EPJC

Synchronization of cell division in yeast cultures of Saccharomyces cerevisiae is widely used in studies on regulation of eukaryotic gene expression and biochemical processes at different stages of the cell cycle. In this study, we compared the efficacy of modern widely used methodologies to achieve and assess the degree of synchronization of cell division in yeast. Based on the literature and our own data, we propose practical recommendations for synchronization of cell divisions in S. cerevisiae using chemical reagents (alpha-factor, hydroxyurea, nocodazole), and a genetic cell-cycle block (temperature-sensitive mutation cdc28-4).

The main purpose of our paper is to construct a viable Kaluza-Klein model satisfying the observable constraints. To this end, we investigate the six-dimensional model with spherical compactification of the internal space. Background matter is considered in the form of a perfect fluid with non-linear equations of state both in the external/our and internal spaces and the model is set to include an additional bare cosmological constant $\Lambda_6$. In the weak-field approximation, the background is perturbed by pressureless gravitating mass that is a static point-like particle. The non-linearity of the equations of state of a perfect fluid makes it possible to solve simultaneously a number of problems. The demand that the parameterized post-Newtonian parameter $\gamma$ be equal to 1 in this configuration, first, ensures compatibility with gravitational tests in the Solar system (deflection of light and time delay of radar echoes) at the same level of accuracy as General Relativity. Second, it translates into the absence of internal space variations so that the gravitational potential coincides exactly with the Newtonian one, securing the absence of the fifth force. Third, the gravitating mass remains pressurless in the external space as in the standard approach to non-relativistic astrophysical objects and meanwhile, acquires effective tension in the internal space., Comment: v2 (matching the publication in Gravitation and Cosmology) = v1 + minor changes; 5 pages, no figures

We consider higher-dimensional massive Brans-Dicke theory with Ricci-flat internal space. The background model is perturbed by a massive gravitating source which is pressureless in the external (our space) but has an arbitrary equation-of-state parameter $\Omega$ in the internal space. We obtain the exact solution of the system of linearized equations for the perturbations of the metric coefficients and scalar field. For a massless scalar field, relying on the fine-tuning between the Brans-Dicke parameter $\omega$ and $\Omega$, we demonstrate that (i) the model does not contradict gravitational tests relevant to the parameterized post-Newtonian parameter $\gamma$, and (ii) the scalar field is not ghost in the case of nonzero $|\Omega|\sim O(1)$ along with the natural value $|\omega|\sim O(1)$. In the general case of a massive scalar field, the metric coefficients acquire the Yukawa correction terms, where the Yukawa mass scale $m$ is defined by the mass of the scalar field. For the natural value $\omega\sim O(1)$, the inverse-square-law experiments impose the following restriction on the lower bound of the mass: $m\gtrsim 10^{-11}\,$GeV. The experimental constraints on $\gamma$ requires that $\Omega$ must be extremely close to $-1/2$., Comment: 8 pages, no figures and tables; matches the version published in Physical Review D

We consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. At such scales, the Universe is highly inhomogeneous and is filled with inhomogeneities in the form of galaxies and the groups of galaxies. We also suggest that the Universe is filled with a perfect fluid, and its fluctuations have peculiar velocities of the same (non-relativistic) order of magnitude as for the inhomogeneities. In this sense, the inhomogeneities (e.g. galaxies) and fluctuations of perfect fluids are coupled with each other. We clarify some important points of this approach and present a brief review of previous studies (e.g. CPL model and Chaplygin gas). We demonstrate that considered perfect fluids which satisfy our approach are really coupled to galaxies concentrating around them. The averaged (over the whole Universe) value of their fluctuations is equal to zero., This mini review (based on papers arXiv: 1301.0418; 1502.04693; 1509.06963) is a contribution to a special issue of Gravitation&Cosmology devoted to 100 year anniversary of K.P. Stanyukovich

We study the second-order scalar perturbations in the conventional $\Lambda$CDM Universe within the cosmic screening approach. The analytic expressions for both the velocity-independent and velocity-dependent second-order scalar perturbations are derived. We demonstrate how the Yukawa screening effect, which is inherent in the first-order metric corrections, manifests itself in the second-order ones. It is shown that the obtained formulas for the second-order perturbations are reduced to the known post-Newtonian expressions at distances much smaller than the Yukawa screening length. In the era of precision cosmology, these analytic formulas play an important role since the second-order metric corrections may affect the interpretation of observational data (e.g., the luminosity-redshift relation, gravitational lensing, baryon acoustic oscillations)., Comment: v2 (matching the publication in Physics of the Dark Universe) = v1 + new Section 4 + minor changes + extra discussion + new Refs.; 14 pages, no figures

The tactical wireless sensor networks control problem formalization was formulated, theoretical bases development directions of tactical WSN control (methods of sensor network control with variable topology for providing the given quality of monitoring and data transmission) are proposed.

The problem of constructing a control system by non-uniform wireless sensor sensors (WSN) is considered. A new paradigm for constructing of a control system for wireless sensor network is proposed — subsystem of coordination and integration of functions monitoring and telecommunications subsystem introduced.

In a multidimensional Kaluza-Klein model with Ricci-flat internal space, we study the gravitational field in the weak-field limit. This field is created by two coupled sources. First, this is a point-like massive body which has a dust-like equation of state in the external space and an arbitrary parameter $\Omega$ of equation of state in the internal space. The second source is a static spherically symmetric massive scalar field centered at the origin where the point-like massive body is. The found perturbed metric coefficients are used to calculate the parameterized post-Newtonian (PPN) parameter $\gamma$. We define under which conditions $\gamma$ can be very close to unity in accordance with the relativistic gravitational tests in the Solar system. This can take place for both massive or massless scalar fields. For example, to have $\gamma \approx 1$ in the Solar system, the mass of scalar field should be $\mu \gtrsim 5.05\times 10^{-49}$g $\sim 2.83\times 10^{-16}$eV. In all cases, we arrive at the same conclusion that to be in agreement with the relativistic gravitational tests, the gravitating mass should have tension: $\Omega=-1/2$., Comment: 7 pages, no figures

Energy storage systems (ESS) have a wide spectrum of functions. They must provide power quality, shaving of load change, coordination of distributed power systems, bulk energy storage, and end-user reliability, e.g., uninterrupted power supply. In present paper the configuration and design of experimental ESS based on both Li-ion batteries and supercapacitors have been proposed. Such a hybrid energy storage system (HESS) includes three main components: Li-ion batteries, supercapacitors, and grid interconnection consisting of two invertors and control and monitoring system. Energy storage capacity of developed HESS prototype is 100 kWh, nominal power—100 kW, peak power—200 kW. HESS was created and tested within the experimental facility also including 1.5 MW gas turbine power plant, 200 kW controllable active and reactive loads, and control and measurement system. Experimental results showed that HESS successfully provides the following advantages: (i) suppression of voltage, current, and frequency disturbances in the grid; (ii) compensation of reactive power in the circuit; and (iii) uninterrupted power supply. Cost analysis of proposed hybrid system has also been carried out. In comparison with battery ESS without supercapacitors, HESS showed longer life time, lower cost, and higher peak power.

We study a universe filled with dust-like matter in the form of discrete inhomogeneities (e.g., galaxies and their groups and clusters) and two sets of perfect fluids with linear and nonlinear equations of state, respectively. The background spacetime geometry is defined by the FLRW metric. In the weak gravitational field limit, we develop the first-order scalar and vector cosmological perturbation theory. Our approach works at all cosmological scales (i.e. sub-horizon and super-horizon ones) and incorporates linear and nonlinear effects with respect to energy density fluctuations. We demonstrate that the scalar perturbation (i.e. the gravitational potential) as well as the vector perturbation can be split into individual contributions from each matter source. Each of these contributions satisfies its own equation. The velocity-independent parts of the individual gravitational potentials are characterized by a finite time-dependent Yukawa interaction range being the same for each individual contribution. We also obtain the exact form of the gravitational potential and vector perturbation related to the discrete matter sources. The self-consistency of our approach is thoroughly checked. The derived equations can form the theoretical basis for numerical simulations for a wide class of cosmological models., 17 pages, no figures

In this paper, we consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. At these scales, we consider the Universe to be filled with dust-like matter in the form of discretely distributed galaxies, a minimally coupled scalar field and radiation as matter sources. We investigate such a Universe in the mechanical approach. This means that the peculiar velocities of the inhomogeneities (in the form of galaxies) as well as fluctuations of other perfect fluids are non-relativistic. Such fluids are designated as coupled because they are concentrated around inhomogeneities. In the present paper we investigate the conditions under which a scalar field can become coupled, and show that, at the background level, such coupled scalar field behaves as a two component perfect fluid: a network of frustrated cosmic strings with EoS parameter $w=-1/3$ and a cosmological constant. The potential of this scalar field is very flat at the present time. Hence, the coupled scalar field can provide the late cosmic acceleration. The fluctuations of the energy density and pressure of this field are concentrated around the galaxies screening their gravitational potentials. Therefore, such scalar fields can be regarded as coupled to the inhomogeneities., 14pages, 1 figure

In this paper, we consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. At these scales, the Universe is filled with inhomogeneously distributed discrete structures (galaxies, groups and clusters of galaxies). Supposing that the Universe contains also the cosmological constant and a perfect fluid with a negative constant equation of state (EoS) parameter $\omega$ (e.g., quintessence, phantom or frustrated network of topological defects), we investigate scalar perturbations of the FRW metrics due to inhomogeneities. Our analysis shows that, to be compatible with the theory of scalar perturbations, this perfect fluid, first, should be clustered and, second, should have the equation of state parameter $\omega=-1/3$. In particular, this value corresponds to the frustrated network of cosmic strings. Therefore, the frustrated network of domain walls with $\omega =-2/3$ is ruled out. A perfect fluid with $\omega =-1/3$ neither accelerates nor decelerates the Universe. We also obtain the equation for the nonrelativistic gravitational potential created by a system of inhomogeneities. Due to the perfect fluid with $\omega = -1/3$, the physically reasonable solutions take place for flat, open and closed Universes. This perfect fluid is concentrated around the inhomogeneities and results in screening of the gravitational potential., Comment: 10 pages, no figures

The hypothesis on a relationship between the high frequency of mitotic disturbances in bone marrow cells and the change in the activity of the S9 liver fraction containing promutagen-activating enzymes under olfactory stress in the house mouse Mus musculus has been tested. For this purpose, the effect of the pheromone 2,5-dimethylpyrazine on the frequency of mitotic disturbances in mouse bone marrow cells has been measured by the anaphase-telophase assay. The Ames test using Salmonella typhimurium has been employed to compare the capacities of the S9 liver fractions from stressed and intact mice for activating the promutagen 2-aminofluorene. It has been demonstrated that the increased frequency of mitotic disturbances in bone marrow cells induced by the pheromonal stressor in male house mice is accompanied by an increased promutagen-activating capacity of the S9 liver fraction. The model system used in the study allowed the genetic consequences of the exposure to the olfactory stressor to be estimated and the possible mechanisms of genome destabilization to be assumed.

We study a universe filled with cold dark matter in the form of discrete inhomogeneities (e.g., galaxies) and dark energy in the form of a continuous perfect fluid. We develop a first-order scalar perturbation theory in the weak gravity limit around a spatially flat Friedmann universe. Our approach works at all cosmic scales and incorporates linear and nonlinear effects with respect to energy density fluctuations. The gravitational potential can be split into individual contributions from each matter source. Each potential is characterized by a Yukawa interaction with the same range, which is of the order of 3700 Mpc at the present time. The derived equations can form the theoretical basis for numerical simulations for a wide class of modern cosmological models., Comment: This essay received an Honorable Mention in the 2017 Essay Competition of the Gravity Research Foundation

We consider multidimensional cosmological model with a higher-dimensional product manifold M = R x R^{d_0} x H^{d_1}/\Gamma where R^{d_0} is d_0-dimensional Ricci-flat external (our) space and H^{d_1}/\Gamma is d_1-dimensional compact hyperbolic internal space. M2-brane solution for this model has the stage of accelerating expansion of the external space. We apply this model to explain the late time acceleration of our Universe. Recent observational data (the Hubble parameter at the present time and the redshift when the deceleration parameter changes its sign) fix fully all free parameters of the model. As a result, we find that considered model has too big size of the internal space at the present time and variation of the effective four-dimensional fine structure constant strongly exceeds the observational limits., Comment: 5 pages, 3 figures, LaTex, a few remarks and reference added

Let M be either the space of 2π-periodic functions Lp, where 1 ≤ p < ∞, or C; let ωr(f, h) be the continuity modulus of order r of the function f, and let $$D_{n,r,l} (f,x) = \frac{{( - 1)^{\tfrac{r}{2} + 1} 2}}{{C_r^{r/2} }}\int\limits_\mathbb{R} {\left\{ {\sum\limits_{k = 1}^{r/2} {( - 1)^{k + r/2} C_r^{k + r/2} f(x + kt)} } \right\}} V_{n,2l} (t) dt$$ , where $$V_{n,2l} (t) = \frac{{(2l - 1)!2^{2l - 1} }}{{\lambda _{2l} \pi (n + 1)^{2l - 1} }}\left( {\frac{{\sin \tfrac{{(n + 1)t}}{2}}}{t}} \right)^{2l} , \lambda _{2l} = \sum\limits_{k = 0}^{l - 1} {( - 1)^k C_{2l}^k (l - k)^{2l - 1} } $$ , be the generalized Jackson-Vallee-Poussin integral. Denote $$K_m (f) = K_{m,\varphi } (f) = \mathop {\sup }\limits_{0 < v < \infty } \frac{{\omega _m (f,v)}}{{\varphi (v)}}$$ . The paper studies the quantity Km(f − Dn,r,l(f)). The general results obtained are applicable to other approximation methods. Bibliography: 11 titles.

In the paper, a generalization of a known theorem by Hardy and Young is obtained; a formula interrelating the integral of a 2π-periodic function over the period with the integral over the entire axis is established; new approximation characteristics for functions belonging to saturation classes of continuity modules of different orders for the spaces Lp of periodic functions are provided, and some issues concerning approximation, in the uniform metric, of continuous periodic functions even with respect to each of their variables and having nonnegative Fourier coefficients are considered. Bibliography: 17 titles.