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Dudka A.,Russian Academy of Sciences
Journal of Applied Crystallography | Year: 2010

New methods have been developed for scaling the intensities of diffraction reflections measured on a diffractometer with a CCD detector. The algorithm involves cyclic alternation of the refinement of a structure model from experimental data corrected for anisotropic effects with the refinement of anisotropic parameters from initial data for a fixed structure model. The first method consists of refining scale factors for the intensities after they have first been corrected for anisotropic effects of known physical nature (thermal diffuse scattering, absorption, extinction etc.). It has been shown that the majority of the observed biases of intensities are caused by the characteristics of the CCD detector and the technique used for data collection on the diffractometer, rather than by the properties of the sample. The second (alternative) method of fixed scaling has been implemented here. This method does not require refinement of empirical scale factors but uses intensity correction maps obtained by averaging the results derived from several experiments with different crystals. The first map describes the non-uniformity of the response over the surface area of the detector. The second map accounts for distortions dependent on the setting angles of the goniometer. The methods were checked for data measured on an Oxford Diffraction Xcalibur Sapphire 3 CCD diffractometer. The proposed methods significantly improve the results of the refinement and make it possible to obtain a structure model that is reproduced in repeated investigations of samples of the same compound. © 2010 International Union of Crystallography Printed in Singapore-all rights reserved.

Khramov A.V.,Russian Academy of Sciences
Insect Systematics and Evolution | Year: 2013

Two new species of Mantispidae, Mesithone carnaria sp.n. and M. monstruosa sp.n., from the Upper Jurassic deposits at Karatau (Kazakhstan) are described. These new species are assigned to the extinct subfamily Mesithoninae. M. protea Panfilov, 1980 and M. gracilis Panfilov, 1980 are excluded from Mesithone. The family Mesithonidae is synonymized with Mantispidae and the relationship of Mesithoninae with the four recent mantispid subfamilies is briefly discussed. © Koninklijke Brill NV, Leiden, 2013.

Maslov V.P.,Russian Academy of Sciences
Russian Journal of Mathematical Physics | Year: 2010

By an "ideal gas" we mean a gas which formally does not depend on the form of the interaction between the particles. We construct the thermodynamics (the equation of state) of such a gas, and this thermodynamics depends on three parameters corresponding to the Zeno-line and to the value of the compressibility factor Z at the critical point (a three-parameter family of three-dimensional Lagrangian manifolds). © 2010 Pleiades Publishing, Ltd.

Samoylovich M.I.,Central Research and Technology Institute TechnoMash | Talis A.L.,Russian Academy of Sciences
Acta Crystallographica Section A: Foundations of Crystallography | Year: 2010

It is established that the eight-dimensional lattice E 8 and the Mathieu group M 12 determine a unique sequence of algebraic geometry constructions which define a special class of simple 24-vertex, 14-face polyhedra with four-, five- and six-edge faces. As an example, the graphs of the ten stereohedra that generate most known tetrahedrally coordinated water cages of gas hydrates have been derived a priori. A structural model is proposed for the phase transition between gas hydrate I and ice. © 2010 International Union of Crystallography Printed in Singapore - all rights reserved.

Chukhovskii F.N.,Russian Academy of Sciences | Polyakov A.M.,National University of Science and Technology "MISIS"
Acta Crystallographica Section A: Foundations of Crystallography | Year: 2010

The Green function formalism is applied to the problem of grazing-incidence small-angle X-ray scattering from statistically rough surfaces. Kirchhoffs integral equation is used to describe the X-ray wavefield propagation through a single rough surface separating vacuum and medium. Taking into account multiple diffuse X-ray scattering effects, the reflection R coh(θ) and transmission T coh(θ) coefficients of the specular wave are obtained using the Gaussian statistical model of rough surfaces in terms of the two-point height-height correlation function. In the limiting cases when the correlation length ξ is equal to zero or infinity, analytical formulae for the reflection R coh(θ) and transmission T coh(θ) coefficients of the specular wave are obtained. It is important that in the case ξ → they coincide with the corresponding reflection R DW(θ) and transmission T DW(θ) coefficients related to the conventional Debye-Waller approximation for describing the grazing X-ray scattering from a rough surface. In the case of finite values of correlation length ξ the reflection |R coh(θ)| 2 and transmission |T coh(θ) | 2 scans are numerically calculated. © 2010 International Union of Crystallography Printed in Singapore - all rights reserved.

Dudka A.,Russian Academy of Sciences
Journal of Applied Crystallography | Year: 2010

A new method is proposed to improve structure modeling by taking into account the half-wavelength contribution (γ/2) to X-ray data measured on CCD and image-plate diffractometers. Such an effect arises because the reflection intensities contain contributions associated with both the γand the γ/2 wavelengths. The ratio w of these two contributions is a new parameter refined using the full-matrix least-squares techniques. The new method does not require any additional measurement or information. According to the tests performed, proper account of the γ/2 contribution lowers the wR 2(|F|2) factors by a relative percent difference of 4-14% and the atomic displacement parameters by ̃1-4 s.u. Other effects are analyzed that might correlate with the γ/2 contribution, such as absorption, charge-density redistribution, thermal diffuse scattering and extinction. Strong correlation was found between w and the other parameters, but a fixed γ/2 correction reduces this difficulty. The value of w is found to be both characteristic of the diffractometer and a general indicator of the refinement quality (similar to R factors). © 2010 International Union of Crystallography Printed in Singapore-all rights reserved.

Galzitskaya O.V.,Russian Academy of Sciences
Current Protein and Peptide Science | Year: 2010

The problem of protein self-organization is one of the most important problems of molecular biology nowadays. Despite the recent success in the understanding of general principles of protein folding, details of this process are yet to be elucidated. Moreover, the prediction of protein folding rates has its own practical value due to the fact that aggregation directly depends on the rate of protein folding. The time of folding has been calculated for 67 proteins with known experimental data at the point of thermodynamic equilibrium between unfolded and native states using a Monte Carlo model where each residue is considered to be either folded as in the native state or completely disordered. The times of folding for 67 proteins which reach the native state within the limit of 10 8 Monte Carlo steps are in a good correlation with the experimentally measured folding rate at the mid-transition point (the correlation coefficient is -0.82). Theoretical consideration of a capillarity model for the process of protein folding demonstrates that the difference in the folding rate for proteins sharing more spherical and less spherical folds is the result of differences in the conformational entropy due to a larger surface of the boundary between folded and unfolded phases in the transition state for proteins with more spherical fold. The capillarity model allows us to predict the folding rate at the same level of correlation as by Monte Carlo simulations. The calculated model entropy capacity (conformational entropy per residue divided by the average contact energy per residue) for 67 proteins correlates by about 78% with the experimentally measured folding rate at the mid-transition point. © 2010 Bentham Science Publishers Ltd.

Kuzmin M.I.,Russian Academy of Sciences | Yarmolyuk V.V.,RAS Institute of Geology and Mineralogy | Kravchinsky V.A.,University of Alberta
Earth-Science Reviews | Year: 2010

We review intraplate magmatism in Siberia and its folded surroundings from 480. Ma to the present. We describe several large igneous provinces (LIPs) and the intervals in which they were continuously formed within the limits of the Siberian continent: the Altay-Sayan Early Paleozoic magmatic area (598-446. Ma), the Altay-Sayan LIP (408-393. Ma), the Viluy LIP (380-350. Ma), the Barguzin-Vitim LIP (310-275. Ma), the Late Paleozoic rift system of Central Asia (318-242. Ma), the Siberian traps and West Siberian rift system (250-249. Ma), the East-Mongolian and West-Trans-Baikalian LIP (228-195. Ma), and a number of various aged Late Mesozoic and Cenozoic rift zones and magmatic areas (from 160. Ma to the present day).Following Lawver and Muller (1994), Kharin (2000), Lawver et al. (2002) and Chernysheva et al. (2005), we accept the position of the Icelandic hot spot under the Siberian trap area at the Permo-Triassic boundary. That enables us to estimate the geographic coordinates of the Siberian trap location at 250. Ma (they are the same as Iceland today). Presently the Icelandic hot spot is situated above the African large low shear velocity province (LLSVP) that indicates a hot mantle plume. We suggest a set of paleogeographic reconstructions of the Siberian continent for which we evaluate the paleolatitude based on the paleomagnetic data and estimate the paleolongitude position by placing Siberia above the African LLSVP. Furthermore, we estimate the geographic coordinates for other ancient hot spots in the framework of the African LLSVP that we consider to be responsible for the intraplate magmatism during different time periods in the Phanerozoic eon.Available rare element and isotopic characteristics of the intraplate magmatic rocks of Siberia enable us to determine three primary sources - moderately depleted mantle (PREMA), enriched mantle (EM-I and EM-II) - of the mantle origin magma. We propose that the model explains the interaction of the hot mantle plume including hot spots (plume tails) with the Siberian intraplate magmatism areas throughout the Phanerozoic eon. © 2010 Elsevier B.V.

Mirzade F.Kh.,Russian Academy of Sciences
Physica B: Condensed Matter | Year: 2011

The mechanical behavior of solid layers subjected to laser irradiation is investigated by a dynamical model that is based on coupled evolution equations for the elastic displacement of the medium and lattice defect-density fields. The evolution of defect-density is governed by the (i) generation of defects by irradiation, (ii) their diffusion and recombination and (iii) diffusion induced by strain field. The strain field associated with lattice dilatation due to atomic defects is shown to couple with deformation fields of the layer. Frequency equations corresponding to the symmetric and anti-symmetric modes of vibration of the layer are obtained. It is found that coupling between diffusion and strain fields cause dispersion of the general waveform. Explicit expressions are defined for the wave velocity, and the attenuation (amplification) coefficients which characterize these waves. © 2011 Elsevier B.V. All rights reserved.

Savanov I.S.,Russian Academy of Sciences
Astronomy Reports | Year: 2012

We have determined activity cycles for coolest M dwarfs using photometry from the ASAS survey. The time scales of brightness variations were determined for the program stars using calculated amplitude power spectra and wavelet spectra. Most of ther program stars display periodicities in their light-curve variations, with periods from hundreds of days to years. Analysis of diagrams plotting P cyc/P rot versus 1/P rot in logarithmic coordinates shows that the data for all our program objects fit the general relation quite well. No differences in the activity cycles are found for our sample stars, which have different masses and thus internal structures, some having convective envelopes and others being totally convective. Our analysis indicates that the slope i of this relation is close to unity, regardless of whether it is determined from all data, from data for the shortest cycles, or from data for the longest cycles. This value of i differs from values in the literature for stars of other spectral types. Our analysis of the P cyc-P rot relation indicates that the activity cycles for the studied sample of M dwarfs do not depend on the rotation periods of these objects. The data for the studied objects do not agree with any of the relations for relatively young (active) stars or older (less active) stars. The studied M dwarfs probably form another branch of low-mass stars that display more random, irregular magnetic activity on their surfaces, which is generated and supported by the distributed dynamo mechanism or a small-scale dynamo mechanism. © 2012 Pleiades Publishing, Ltd.

Tikhonov N.A.,Russian Academy of Sciences
Astronomy Letters | Year: 2012

Based on archival Hubble Space Telescope images, we have performed stellar photometry for eight edge-on spiral and irregular galaxies. We have identified stars with ages of 20, 50, 80, 160, and 500 Myr in the derived Hertzsprung-Russell diagrams and constructed their number density distributions perpendicularly to the plane of the galactic disk. We have determined the sizes of the stellar subsystems and constructed the size-age diagrams for the stars constituting these subsystems. The stellar subsystems have been found to expand in all of the investigated galaxies within the range of ages studied (from 20 to 500 Myr). The expansion velocity of the subsystems decreases as one recedes from the galactic plane. The subsystems with ages of 1.5 and 6 Gyr also exhibit an increase in their sizes with age. The sizes of these subsystems approach those of the thick disk consisting of red giants. Our results confirm the model of thick-disk formation in irregular and low-mass spiral galaxies through thin-disk expansion. © 2012 Pleiades Publishing, Ltd.

Nagovitsyn Y.A.,Russian Academy of Sciences | Pevtsov A.A.,U.S. National Solar Observatory | Livingston W.C.,U.S. National Solar Observatory
Astrophysical Journal Letters | Year: 2012

Recent studies revealed a controversy in long-term variations in sunspot field strengths. On one hand, the sunspot field strengths computed by averaging both large and small sunspots and pores show a gradual decrease over the declining phase of solar Cycle 23 and the rising phase of Cycle 24. On the other hand, the strongest sunspot field strengths demonstrate only solar cycle variations with no long-term decline. Here, we investigate the field strength and area properties of sunspots in an attempt to reconcile the presence of both tendencies in recent sunspot field strength measurements. First, we analyze the data set from Penn & Livingston, and we show that in addition to the previously reported long-term decline, the data show the solar cycle variation when only sunspots with the strongest magnetic fields are included. Next, we investigate the variations in the number of sunspots of different sizes, and we find a negative correlation between the numbers of small and large sunspots. Finally, we show that during the period of 1998-2011, the number of large sunspots gradually decreased, while the number of small sunspots steadily increased. We suggest that this change in the fraction of small and large sunspots (perhaps, due to changes in the solar dynamo) can explain the gradual decline in average sunspot field strength as observed by Penn & Livingston. © 2012. The American Astronomical Society. All rights reserved.

Altshuler B.L.,Columbia University | Aleiner I.L.,Columbia University | Yudson V.I.,Russian Academy of Sciences
Physical Review Letters | Year: 2013

We consider chiral electrons moving along the one-dimensional helical edge of a two-dimensional topological insulator and interacting with a disordered chain of Kondo impurities. Assuming the electron-spin couplings of random anisotropies, we map this system to the problem of the pinning of the charge density wave by the disordered potential. This mapping proves that arbitrary weak anisotropic disorder in coupling of chiral electrons with spin impurities leads to the Anderson localization of the edge states. © 2013 American Physical Society.

Kartashov Y.V.,Polytechnic University of Catalonia | Kartashov Y.V.,Russian Academy of Sciences | Konotop V.V.,University of Lisbon | Abdullaev F.K.,Sao Paulo State University
Physical Review Letters | Year: 2013

We report a diversity of stable gap solitons in a spin-orbit-coupled Bose-Einstein condensate subject to a spatially periodic Zeeman field. It is shown that the solitons can be classified by the main physical symmetries they obey, i.e., symmetries with respect to parity (P), time (T), and internal degree of freedom, i.e., spin (C), inversions. The conventional gap and gap-stripe solitons are obtained in lattices with different parameters. It is shown that solitons of the same type but obeying different symmetries can exist in the same lattice at different spatial locations. PT and CPT symmetric solitons have antiferromagnetic structure and are characterized, respectively, by nonzero and zero total magnetizations. © 2013 American Physical Society.

The two-state model for a protein molecule with attached single donor-acceptor (D-A) pair is considered. The model uses the intensity fluctuations in D- and A-fluorescence for studying fluctuations of the amplitude and rate of FRET resulting from folding/unfolding fluctuations in the protein molecule. Such approach is in contrast to the ordinary approach which analyses the shape S(E) of the distribution of FRET efficiency E in the fluorescence of single D-A pair. Analysis of the shapes of the photon distribution functions and statistical treating of D- and A-fluorescence traces of single D-A pair enables one to find the amplitude and the rate of changes in the distance RDA between the donor and the acceptor molecules attached to a single protein molecule. © 2015 American Chemical Society.

Moiseev S.A.,Russian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

A scheme of photon echo-based quantum memory in the optimal optical QED cavity with off-resonant Raman atomic transition is proposed. The scheme employs the atomic ensembles characterized by an optically thin resonant transition and natural inhomogeneous broadening of the resonant line composed of the arbitrary narrow homogeneous spectral components. The scheme provides robust and quite simple coherent control of the light atoms dynamics that can be implemented by using an existing optical technique and opens a practical way for realization of the efficient long-lived multimode optical quantum memory. © 2013 American Physical Society.

Gontcharov G.A.,Russian Academy of Sciences
Astronomy Letters | Year: 2012

The sample of 37 485 suspected OB stars selected by Gontcharov (2008) from the Tycho-2 catalogue has been cleaned of the stars that are not of spectral types OV-A0V. For this purpose, the apparent magnitude V T from Tycho-2, the absolute magnitude M VT calibrated as a function of the dereddened color index (B T - V T) 0, the interstellar extinction A VT calculated from the 3D analytical model by Gontcharov (2009) as a function of the Galactic coordinates, and the photometric distance r ph calculated as a function of V T, M VT, and A VT have been reconciled in an iterative process. The 20 514 stars that passed the iterations have (B T - V T) 0 < 0 and M VT > -5 and are considered as a sample of OV-A0V stars complete within 350 pc of the Sun. Based on the theoretical relation between the dereddened color and age of the stars, the derived sample has been divided into three subsamples: (B T - V T) 0 < -0. 2, -0. 2 < (B T - V T) 0 < -0. 1, and -0. 1 < (B T - V T) 0 < 0, younger than 100, 100-200, and 200-400 Myr, respectively. The spatial distribution of all 20 514 stars and the kinematics analyzed for more than 1500 stars with radial velocities from the PCRV and RAVE catalogues are different for the subsamples, showing smooth rotations, shears, and deformations of the layer of gas producing stars with the formation of the Gould Belt, the Great Tunnel, the Local Bubble, and other structures within the last 200 Myr. The detected temporal variations of the velocity dispersions, solar motion components, Ogorodnikov-Milne model parameters, and Oort constants are significant, agree with the results of other authors, and show that it is meaningless to calculate the kinematic parameters for samples of stars with uncertain ages or with a wide range of ages. © 2012 Pleiades Publishing, Ltd.

Arkhincheev V.E.,Russian Academy of Sciences
Physica A: Statistical Mechanics and its Applications | Year: 2010

The anisotropic sub-diffusion random walks on multi-dimensional comb structure model have been studied in the continuum approximation. The problem is that in the considered model mean square displacements on different directions have different power temporal dependencies. So this case essentially differs from usual anisotropic diffusion case and it is not obviously how to describe such a diffusion by a unified way. Nevertheless the unified continuum description for such random walks has been developed. As result the new generalization of Fick's law for diffusion current has been obtained for anisotropic anomalous sub-diffusion random walks in multi-dimensional case. Namely, it has been shown that the effective diffusion coefficient in the generalized Fick's law has new operator form: components of diffusion tensor instead of constant values have the fractional order temporal derivatives. © 2009 Elsevier B.V. All rights reserved.

The studies of small helium clusters (up to 100 atoms) and molecular-hydrogen clusters (up to 20 molecules) that are formed in a supersonic gas jet and are coupled by the weak van der Waals interaction with a linear chromophore molecule are reviewed The shift of the frequency of the fundamental vibration of the chromophore, as well as a change in the moment of inertia of a cluster with its growth, has been detected by their rotational and vibrational-rotational spectra. A nonclassical behavior of the moment of inertia manifested in its decrease beginning with a certain number of attached He atoms (H2 molecules) has been revealed. This behavior indicates that a part of a cluster is decoupled from the rotational motion of a molecule. The key question of these studies is whether such behavior of the moment of inertia is the manifestation of the super-fluidity of helium and hydrogen at microscopic level. The results are compared to the spectroscopy of molecules and hydrogen clusters in liquid-helium nanodroplets. © 2013 Pleiades Publishing, Ltd.

Parfenyev V.M.,Russian Academy of Sciences | Vergeles S.S.,Moscow Institute of Physics and Technology
Optics Express | Year: 2014

We present a quantum theory of a spaser-based nanolaser, under the bad-cavity approximation. We find first- and second-order correlation functions g(1)(t ) and g(2)(t ) below and above the generation threshold, and obtain the average number of plasmons in the cavity. The latter is shown to be of the order of unity near the generation threshold, where the spectral line narrows considerably. In this case the coherence is preserved in a state of active atoms in contradiction to the good-cavity lasers, where the coherence is preserved in a state of photons. The damped oscillations in g(2)(t ) above the generation threshold indicate the unusual character of amplitude fluctuations of polarization and population, which become interconnected in this case. Obtained results allow to understand the fundamental principles of operation of nanolasers. © 2014 Optical Society of America.

A new species, Phytoptus atherodes, an eriophyoid mite found on Carex atherodes Spreng. in North-West Russia, is described and a supplementary description of the poorly known species, Phytoptus hirtae Roivainen 1950, from Carex hirta L. is given. P. atherodes sp. n. has deutogyne and protogyne females which differ in the length of the body, prodorsal shield, setae v, ψ and c1; the number of dorsal annuli and length and number of empodial rays. Variability of empodial ray numbers among summer (protogyne) and winter (deutogyne) females of P. atherodes sp. n. and P. hirtae was studied for the first time and may reflect different stages of evolution within the genus Phytoptus. Copyright © 2011 · Magnolia Press.

Vedenina V.,Russian Academy of Sciences
Biological Journal of the Linnean Society | Year: 2011

Closely related grasshopper species of the Chorthippus albomarginatus group are notable for their extremely complex courtship songs, accompanied by a visual display. Two species of this group, Ch. albomarginatus and Ch. oschei, were previously shown to hybridize in a wide mosaic hybrid zone in Ukraine and Moldova. In this paper, variation in five courtship song characters, one character of visual display and the number of stridulatory pegs were analysed across the hybrid zone to estimate selection against hybrids and strength of assortative mating. Comparison of cline width and position across the hybrid zone showed concordant and coincident clines in four traits, such as three song characters and one morphological character, and discordant and non coincident clines in two other song characters and the character of visual display. Concordance of clines in different characters suggests an equal strength of selection acting on underlying loci. Increase of variance and covariance between phenotypic traits at the cline centre could more likely result from assortative mating than from selection against hybrids. Most pairwise cases showed the highest covariance for the oschei like, than for the albomarginatus like hybrid populations. This indicates that introgression of the oschei genes into the albomarginatus genome is stronger than vice versa, and may be evidence of the movement of the hybrid zone in favour of Ch. albomarginatus. Analysis of associations between phenotype and local vegetation showed that mosaic structure of the hybrid zone is explained to a great extent by habitat-phenotype associations. © 2011 The Linnean Society of London.

Turitsyn S.K.,Aston University | Bale B.G.,Aston University | Bale B.G.,Lincoln Laboratory | Fedoruk M.P.,Russian Academy of Sciences
Physics Reports | Year: 2012

Nonlinear systems with periodic variations of nonlinearity and/or dispersion occur in a variety of physical problems and engineering applications. The mathematical concept of dispersion managed solitons already has made an impact on the development of fibre communications, optical signal processing and laser science. We overview here the field of the dispersion managed solitons starting from mathematical theories of Hamiltonian and dissipative systems and then discuss recent advances in practical implementation of this concept in fibre-optics and lasers. © 2012 Elsevier B.V.

Mirzade F.K.,Russian Academy of Sciences
Physica B: Condensed Matter | Year: 2011

A model of the diffusionelastic instability that appears in an ensemble of non-equilibrium atomic defects in unbounded condensed media as well as on the free surface of a half-space is introduced and studied. The dynamical model developed here is based on coupled evolution equations for the elastic displacement of the medium and atomic defect density fields. The idea of an instability model is related to a drift of atomic defects under the influence of elastic fields. It is shown that the development of this instability creates ordered structures of coupled strain and defect-concentration fields. Dispersion relationships for the growth increment of these structures are derived and their characteristic scales are obtained. © 2010 Elsevier B.V.All rights reserved.

Veretennikova E.E.,Russian Academy of Sciences
Ecological Engineering | Year: 2015

In this study the lead (Pb) concentrations and Pb accumulation rates are investigated in the two cores of remote ridge-hollow complex (RHC). RHC is a raised bog located in north-eastern spurs of the Great Vasyugan Mire in West Siberia (56°58'N 82°36'E). One of the cores was formed at the ridge (Rc) while the second at the hollow (Hc). Peat cores present the period of Hc - 5439. ca. yr BP and Rc - 2591. ca. yr BP.The investigated peat bog is considered appropriate to study atmospheric Pb deposition due to Pb being immobile in these peat cores. The average values of Pb concentrations for complete vertical peat cores were obtained for Rc and Hc (1.48±1.90 and 1.67±1.65μgg-1, respectively) and demonstrated to have a good agreement with those for natural peat bogs in the north of West Siberia. The background values were also calculated (0.39±0.26 and 0.37±0.29μgg-1) demonstrating to have a good agreement with peat archives from pre-anthropogenic times in Europe, but both anthropogenic Pb concentrations (2.80±1.73 and 2.47±1.58μgg-1) and Pb accumulation rates (0.32±0.22 and 0.28±0.18mgm-2y-1) are very low in comparison with Europe. Using calculations for the RHC, time period of first records of anthropogenic Pb concentrations, when Pb was supplied by anthropogenic activity, has been defined. This time corresponds to 800cayr BP. It dates much later than in Europe and Russian Plain where the Pb concentration provided information on early human activities dated from 1000 to 3000 14C BP. The average values of anthropogenic Pb concentration and Pb accumulation rate in investigated cores are higher compared with the background values of both parameters in ~7-18 times, but even the maximum Pb concentration is much lower compared to other countries of Europe.The Pb concentrations in RHC are generally low and therefore the local atmospheric deposition and terrestrial pathways do not represent major environmental hazard. In modern times in the peatlands such as RHC remote from industrial Pb sources and located in areas with low levels of production and economic activity, Pb concentrations and accumulations rates mainly result from the global atmospheric pollution typical for the beginning of the industrial age. © 2015 Elsevier B.V.

Leinson L.B.,Russian Academy of Sciences
Journal of Cosmology and Astroparticle Physics | Year: 2014

Direct Chandra observations of a surface temperature of isolated neutron star in Cassiopeia A (Cas A NS) and its cooling scenario which has been recently simultaneously suggested by several scientific teams put stringent constraints on poorly known properties of the superfluid neutron star core. It was found also that the thermal energy losses from Cas A NS are approximately twice more intensive than it can be explained by the neutrino emission. We use these unique data and well-defined cooling scenario to estimate the strength of KSVZ axion interactions with neutrons. We speculate that enlarged energy losses occur owing to emission of axions from superfluid core of the neutron star. If the axion and neutrino losses are comparable we find cn 2m a 2∼ 5.7× 10-6 eV2, where ma is the axion mass, and cn is the effective Peccei-Quinn charge of the neutron. (Given the QCD uncertainties of the hadronic axion models, the dimensionless constant cn could range from -0.05 to 0.14.).

Glagolevskij Y.V.,Russian Academy of Sciences
Astrophysics | Year: 2014

Estimates of the ages of magnetic stars show that the oldest have ages of t = 109 years. The theoretical calculations are confirmed by indications that the damping constant for the magnetic field owing to ohmic losses is τ ≫109 years. This also supports the assumption that, prior to the onset of convection, there are no reasons for decay of the magnetic field in the atmospheres of magnetic stars other than ohmic damping. The time variation of the surface magnetic field is actually determined only by two simultaneously acting, oppositely directed factors: a decrease in the field with increasing stellar radius and an increase owing to the relaxation of small structures. Additional data show that the reduction in the average surface magnetic field with the evolutionary increase in a star's radius essentially has a cubic dependences. This confirms the assumption that the large-scale magnetic field approaches a dipole configuration. © 2014 Springer Science+Business Media New York.

Burinskaya T.M.,Russian Academy of Sciences
Plasma Physics Reports | Year: 2014

The Moon's surface illuminated by the Sun acquires an electric charge due to photoelectron emission and interaction with the solar wind plasma. The influence of the solar wind on the nonmonotonic distribution of the electric potential near the Moon's surface is studied in a wide range of the densities of emitted photoelectrons. It is found that, for any photoelectron density, the surface potential reaches its minimum value for a slow solar wind. Although the electron thermal velocity can exceed the solar wind velocity by several times, taking into account the directed flow velocity in the electron velocity distribution function substantially affects the value of the potential in the lunar regolith regions not enriched with hydrogen, for which the photoelectric work function under solar irradiation is significantly higher than for regions enriched with hydrogen. © 2014 Pleiades Publishing, Ltd.

Vysloukh V.A.,Universidad de Las Americas Puebla | Kartashov Y.V.,Polytechnic University of Catalonia | Kartashov Y.V.,Russian Academy of Sciences
Optics Letters | Year: 2014

We study resonant mode conversion in parity time (PT)-symmetric multimode waveguides, where symmetry breaking manifests itself in the sequential destabilization (i.e., the appearance of complex eigenvalues) of the pairs of adjacent guided modes. We show that efficient mode conversion is possible even in the presence of the resonant longitudinal modulation of the complex refractive index. The distinguishing feature of the resonant mode conversion in the PT-symmetric structure is a drastic growth of the width of the resonance curve when the gain/losses coefficient approaches a critical value, at which symmetry breaking occurs. We found that in the system with broken symmetry, the resonant coupling between the exponentially growing mode and the stable higher-order one effectively stabilizes dynamically coupled pairs of modes and remarkably diminishes the average rate of the total power growth. © 2014 Optical Society of America

Korshunov M.M.,Russian Academy of Sciences
Physics-Uspekhi | Year: 2014

The multiorbital spin-fluctuation theory of pairing can explain many observed features of iron-based superconductors, in particular, the different variants of the experimentally examined behaviors of the superconducting gap. Soon after the discovery of superconductivity in pnictides, estimates were made of the possibility of pairing due to the electron-phonon interaction. The coupling constant appears to be even smaller than that for aluminum. This led to the conclusion that it is unlikely that the pairing caused by electron-phonon interaction could play a leading role in the emergence of superconductivity. The anisotropic s∓state and its nodal structure on Fermi surfaces are quite sensitive to some details of the electronic structure, such as the orbital character of the bands, spin-orbit interaction, and changes in the band structure due to the doping.

Kataev A.L.,Russian Academy of Sciences
Journal of High Energy Physics | Year: 2014

Conformal symmetry-based relations between concrete perturbative QED and QCD approximations for the Bjorken , the Ellis-Jaffe sum rules of polarized lepton- nucleon deep-inelastic scattering (DIS), the Gross-Llewellyn Smith sum rules of neutrino-nucleon DIS, and for the Adler functions of axial-vector and vector channels are derived. They result from the application of the operator product expansion to three triangle Green functions, constructed from the non-singlet axial-vector, and two vector currents, the singlet axialvector and two non-singlet vector currents and the non-singlet axial-vector, vector and singlet vector currents in the limit, when the conformal symmetry of the gauge models with fermions is considered unbroken. We specify the perturbative conditions for this symmetry to be valid in the case of the U(1) and SU(N c) models. The all-order perturbative identity following from the conformal invariant limit between the concrete contributions to the Bjorken, the Ellis-Jaffe and the Gross-Llewellyn Smith sum rules is proved. The analytical and numerical O(α4) and O α2 s) conformal symmetry based approximations for these sum rules and for the Adler function of the non-singlet vector currents are summarized. Possible theoretical applications of the results presented are discussed. © 2014 The Authors.

Goubko M.,Russian Academy of Sciences
Match | Year: 2016

In 1997 Klavzar and Gutman suggested a generalization of the Wiener index to vertex-weighted graphs. We minimize the Wiener index over the set of trees with the given vertex weights' and degrees' sequences and show an optimal tree to be the, so-called, Huffman tree built in a bottom-up manner by sequentially connecting vertices of the least weights.

Glagolevskij Y.V.,Russian Academy of Sciences
Astrophysics | Year: 2014

A possible scenario is proposed for the origin and evolution of magnetic stars based on the observational data accumulated up to now. The large difference in magnetic structures and the predominant orientation of the magnetic dipoles are explained, along with the mechanism by which 10% of the magnetic stars differ from normal. A reason is discovered for the slow axial rotation of the stars and a cause is found for the absence of strong magnetic fields in Ae/Be Herbig stars. © 2014, Springer Science+Business Media New York.

Kondratyev B.P.,Russian Academy of Sciences
Monthly Notices of the Royal Astronomical Society | Year: 2014

In this paper, the idea of a single Gaussian elliptical ring on a circular two-dimensional ring or, in the limit, a continuous disc is generalized. Such a ring (hereafter, the R-ring) can consist of identical Keplerian elliptic orbits, of fixed a and e, uniformly portioned on the azimuth angle, or/and filled with orbits that precess around a central star or black hole. The special method of radially averaging the mass of moving bodies is developed. For this wide annulus, we compute the surface density, the two-dimensional and three-dimensional potentials, the mutual gravitational energy and the rotational energy. The surface density has two sharp peaks at the edges of the R-ring and a deep internal minimum. The Newtonian potential of the R-ring is carefully studied and the spatial equipotential surfaces are calculated. The force of attraction at the edges of the R-ring strives for infinity, and in cavity the circular orbits do not exist. The R-rings can be formed naturally in systems of bodies with a large central mass and play a dynamical role. The model is applied to the assessment of some properties of the clockwise disc in the centre of the Galaxy. For the relation of the rotational energy to the module of mutual gravitational energy, we found τ ≈0.29. The R-ring model offers an explanation for the existence of sharp local minima on rotation curves, which are observed in many flat galaxies. We discuss the physical sources of apsidal precession, and of the associated time-scales. We have found the relations of time-scales of apsidal precession from the supermassive black hole and the nuclear star cluster for orbits inside and outside the cluster. The apsidal precession rate of stars can largely be determined not to be a relativistic effect from the black hole and the Newtonian gravitational influence of the densest stellar cluster around the supermassive black hole. © 2014 The Author. Published by Oxford University Press on behalf of the Royal Astronomical Society.

Gorynya N.A.,Russian Academy of Sciences | Tokovinin A.,Cerro Tololo Inter American Observatory
Monthly Notices of the Royal Astronomical Society | Year: 2014

Several nearby solar-type dwarfs with variable radial velocity were monitored to find their spectroscopic orbits. Orbital elements of HIP 179, 1989, 2981, 5276, 6439, 11218, 21443, 96434 are determined, as well as tentative orbits for HIP 28678 and 41214.We discuss each of those objects. Three of the four double-lined binaries are twins with nearly equal components. All four orbits with periods shorter than 10 d are circular, the remaining orbits are eccentric. © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.

Orlov A.Yu.,Russian Academy of Sciences
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2014

We consider three Ginibre ensembles (real, complex and quaternion-real) with deformed measures and relate them to known integrable systems by presenting partition functions of these ensembles in form of fermionic expectation values. We also introduce double deformed Dyson-Wigner ensembles and compare their fermionic representations with those of Ginibre ensembles. © 2013 Elsevier B.V.

Shevchenko I.I.,Russian Academy of Sciences
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2014

The problem of estimating the maximum Lyapunov exponents of the motion in a multiplet of interacting nonlinear resonances is considered for the case when the resonances have comparable strength. The corresponding theoretical approaches are considered for the multiplets of two, three, and infinitely many resonances (i.e., doublets, triplets, and "infinitets"). The analysis is based on the theory of separatrix and standard maps. A "multiplet separatrix map" is introduced, valid for description of the motion in the resonance multiplet under certain conditions. In numerical experiments it is shown that, at any given value of the adiabaticity parameter (which controls the degree of interaction/overlap of resonances in the multiplet), the value of the maximum Lyapunov exponent in the multiplet of equally-spaced equally-sized resonances is minimal in the doublet case and maximal in the infinitet case. This is consistent with the developed theory. © 2013 Elsevier B.V.

Pollock M.D.,Russian Academy of Sciences
Foundations of Physics | Year: 2014

The Schrödinger equation for a particle of rest mass m and electrical charge ne interacting with a four-vector potential Ai can be derived as the non-relativistic limit of the Klein-Gordon equation (□′ + m2) ψ = 0 for the wave function ψ, where □′ = ηjk ∂′ j∂′ k and ∂′ j = ∂j - ine Aj, or equivalently from the one-dimensional action S1 = - ∫ mds + ∫ ne Aidxi for the corresponding point particle in the semi-classical approximation ψ ~ exp (iS1), both methods yielding the equation i∂0Ψ ≈ (1/2m ηαβ ∂′ α ∂′ β + m + ne Φ) ψ in Minkowski space-time, where α, β = 1, 2, 3 and Φ = -A0. We show that these two methods generally yield equations that differ in a curved background space-time gij, although they coincide when g0α = 0 if m is replaced by the effective mass M ≡ √m2 - ξ R in both the Klein-Gordon action S and S1, allowing for non-minimal coupling to the gravitational field, where R is the Ricci scalar and ξ is a constant. In this case i∂0Ψ ≈ (1/2M′gαβ ∂′ α ∂′ β + MΦ(g) + ne Φ) ψ, where Φ(g) = √g00 and M′ = M/Φ(g) the correctness of the gravitational contribution to the potential having been verified to linear order mΦ(g) in the thermal-neutron beam interferometry experiment due to Colella et al. Setting n = 2 and regarding ψ as the quasi-particle wave function, or order parameter, we obtain the generalization of the fundamental macroscopic Ginzburg-Landau equation of superconductivity to curved space-time. Conservation of probability and electrical current requires both electromagnetic gauge and space-time coordinate conditions to be imposed, which exemplifies the gravito-electromagnetic analogy, particularly in the stationary case, when divA = div A(g) = 0, where Aα = -Aα and A(g)α = -Φ(g) g0α. The quantum-cosmological Schrödinger (Wheeler-DeWitt) equation is also discussed in the D-dimensional mini-superspace idealization, with particular regard to the vacuum potential V and the characteristics of the ground state, assuming a gravitational Lagrangian LD which contains higher-derivative terms up to order R4. For the heterotic superstring theory, LD consists of an infinite series in α′R, where α′ is the Regge slope parameter, and in the perturbative approximation α′{pipe}R{pipe} ≪ 1, V is positive semi-definite for D ≥ 4. The maximally symmetric ground state satisfying the field equations is Minkowski space for 3 ≤ D ≤ 7 and anti-de Sitter space for 8 ≤ D ≤10. © 2014 Springer Science+Business Media New York.

Four new water mite species in the genus Atractides are described: A. yaroslavlensis sp. n. (male, female and larva) and A. ildicus sp. n. (female) from streams in the Yaroslavl Province, and A. komarovkaensis (female) and A. primoryensis (female) from the Primory Territory of Russia are presented. Copyright © 2011 Magnolia Press.

Lobkina V.A.,Russian Academy of Sciences
Earth's Cryosphere | Year: 2015

The analysis of the current state of the regulatory framework used in the evaluation of the snow load on the stages of design and construction has been fulfilled. The observed method of calculation of the value of snow load on the ground for the poorly studied areas has been considered. The method is based on the value of the maximum water equivalence of snow cover and vertical gradient increment of the weight of the snow cover. The algorithm of zoning by the snow load has been carried out. The map "Zoning of the territory of Sakhalin by snow load" has been created using this algorithm.

Ustinovshchikov Yu.I.,Russian Academy of Sciences
Physics-Uspekhi | Year: 2014

We present a critical analysis of research on the thermodynamics, kinetics, and morphology of diffusion phase transitions in alloys. We show that diffusion phase transitions are mainly driven by the chemical potential difference due to a change in the sign of the chemical interaction among the component atoms. We explain how the sign of the chemical interaction energy can be obtained from experimental measurements. Examples are given to illustrate the kinetics and morphology of the ordering-separation phase transition in Ni- and Co-based alloys. We show how introducing the concept of the ordering-separation phase transition may affect our thinking in this area. ©2014 Uspekhi Fizicheskikh Nauk, Russian Academy of Sciences.

Aleksandrova N.I.,Russian Academy of Sciences
Wave Motion | Year: 2014

We study the propagation of transient waves under the action of a vertical step point load on the surface of a half-space filled by a block medium. The block medium is modeled by a square lattice of masses connected by springs in the directions of the axes x, y, and in the diagonal directions. The problem is solved by two methods. Analytically, we obtain asymptotic solutions in the vicinity of the Rayleigh wave at large time intervals. Numerically, we obtain a solution for any finite time interval. We compare these solutions with each other and with the solution to the Lamb problem for an elastic medium. © 2014 Elsevier B.V.

Fotiev S.M.,Russian Academy of Sciences
Earth's Cryosphere | Year: 2015

The typical features of the ice layers occurring in situ in the full sections of the marine sediments have been specified. The comparison of the mineralization and the chemical composition of the ice of the lacustrine and marine waters have proved that the ice layers had been saturated by the lacustrine waters. It was determined that the ice layers began forming only after the full sea regression and considerably later than the perennial freezing of the surrounding deposits. It has been ascertained that thick ice layers cannot be formed during the process of segregational accumulation. The leading role of the process of injective ice accumulation during the formation of the thick layers of the ultrafresh ice inside the strata of the frozen deposits have been proved. The source "feeding" the ice layer occurred to be not inside but outside the surrounding deposits. The conditions of penetration of the lacustrine waters into the strata of the frozen deposits and the layerwise formation of the ice layers have been examined. It was revealed that the delivery of the water from lake to ice layer and its transportation to enormous distances was provided by the huge cryogenic pressure occurring during ice freezing inside the closed lake depression.

Okulov A.Yu.,Russian Academy of Sciences
Applied Optics | Year: 2014

The mechanisms of nonlinear phase-locking of a large fiber amplifier array are analyzed. The preference is given to the most suitable configuration for a coherent coupling of thousands of fundamental spatial mode fiber beams into a single smooth beam ready for chirped pulse compression. It is shown that a Michelson phase-conjugating configuration with double passage through an array of fiber amplifiers has the definite advantage compared to a one-way fiber array coupled in a Mach-Zehnder configuration. Regardless of the amount of synchronized fiber amplifiers, the Michelson phase-conjugating interferometer is expected to do a perfect compensation of the phase-piston errors and collimation of backwardly amplified fiber beams on an entrance/output beam splitter. In both configurations, the nonlinear transformation of the stretched pulse envelope, due to gain saturation, is capable of randomizing the position of chirp inside an envelope; thus it may reduce the visibility of the interference pattern at an output beam splitter. Certain advantages are inherent to the sech-form temporal envelope because of the exponential precursor and self-similar propagation in gain medium. The Gaussian envelope is significantly compressed in a deep gain saturation regime, and the frequency chirp position inside pulse envelope is more deformed. © 2014 Optical Society of America.

Moiseev A.V.,Russian Academy of Sciences
Astrophysical Bulletin | Year: 2014

We present the results of study of the ionized gas velocity fields in 28 nearby (systemic velocity below 1000 km s-1) dwarf galaxies. The observations were made at the 6-m BTA telescope of the SAO RAS with the scanning Fabry-Perot interferometer in the Hα emission line. We were able to measure regular circular rotation parameters in 25 galaxies. As a rule, rotation velocities measured in HII are in a good agreement with the data on the HI kinematics at the same radii. Three galaxies reveal position angles of the kinematic axis in the HII velocity fields that strongly (tens of degrees) differ from the measurements in neutral hydrogen at large distances from the center or from the orientation of the major axis of optical isophotes. The planes of the gaseous and stellar disks in these galaxies most likely do not coincide. Namely, in DDO99 the gaseous disk is warped beyond the optical radius, and in UGC3672 and UGC8508 the inclination of orbits of gas clouds varies in the inner regions of galaxies. It is possible that the entire ionized gas in UGC8508 rotates in the plane polar to the stellar disk. © 2014 Pleiades Publishing, Ltd.

Sachkov M.E.,Russian Academy of Sciences
Astrophysical Bulletin | Year: 2014

Rapidly oscillating chemically peculiar A stars (roAp) pulsate in high-overtone, low degree p-modes and form a sub-group of chemically peculiar magnetic A stars (Ap). Until recently, the classical asteroseismic research, i.e., frequency analysis, of these stars was based on photometric observations both ground-based and space-based. Significant progress has been achieved by obtaining uninterrupted, ultra-high precision data from the MOST, COROT, and Kepler satellites. Over the last ten years, a real breakthrough was achieved in the study of roAp stars due to the time-resolved, high spectral resolution spectroscopic observations. Unusual pulsational characteristics of these stars, caused by the interaction between propagating pulsationwaves and strong stratification of chemical elements, provide an opportunity to study the upper roAp star atmosphere in more detail than is possible for any star but the Sun, using spectroscopic data. In this paper the results of recent pulsation studies of these stars are reviewed. © 2014 Pleiades Publishing, Ltd.

Volovik G.E.,Aalto University | Volovik G.E.,Russian Academy of Sciences | Zubkov M.A.,University of Western Ontario
Nuclear Physics B | Year: 2014

In Ref. [1] Hořava suggested, that the multi-fermion many-body system with topologically stable Fermi surfaces may effectively be described (in a vicinity of the Fermi surface) by the theory with coarse-grained fermions. The number of the components of these coarse-grained fermions is reduced compared to the original system. Here we consider the 3 + 1 D system and concentrate on the particular case when the Fermi surface has co-dimension p = 3, i.e. it represents the Fermi point in momentum space. First we demonstrate explicitly that in agreement with Hořava conjecture, in the vicinity of the Fermi point the original system is reduced to the model with two-component Weyl spinors. Next, we generalize the construction of Hořava to the situation, when the original 3 + 1 D theory contains multi-component Majorana spinors. In this case the system is also reduced to the model of the two-component Weyl fermions in the vicinity of the topologically stable Fermi point. Those fermions experience the emergent gauge field and the gravitational field given by the emergent vierbein. Both these fields (the emergent gauge field and the emergent gravitational field) originate from certain collective excitations of the original system. We speculate, that the given construction may be relevant for the high energy physics in the paradigm, in which the Lorentz symmetry as well as the gravitational and gauge fields are the emergent phenomena, i.e. they appear dynamically in the low energy approximation of the underlined high energy theory. © 2014 The Authors.

Verkhodanov O.V.,Russian Academy of Sciences
Astrophysical Bulletin | Year: 2014

We present a comparison of the angular power spectra and maps represented by the WMAP and Planck mission teams. The spectra are compared in the the multi pole range (2 ≤ ℓ ≤ 50). The ℓ =5, 7, 13, 29, 37, 41-46 harmonics have a discrepancy in the angular power spectra. The maps of the microwave background and their phase characteristics are studied at these spatial frequencies. We show that the discrepancy of the spectra is due to a different account of the systematics linked with the Galaxy, the ecliptic, and possibly with the Earth. These effects, leading to a statistical anisotropy, may be responsible for the observed anomalies in both experiments at low harmonics. © 2014 Pleiades Publishing, Ltd.

Tsukanov A.V.,Russian Academy of Sciences
Russian Microelectronics | Year: 2012

A quantum system, which is one of the most popular and promising in experimental quantum informatics, namely, the NV-center in diamond, is considered. We draw the reader's attention to the results obtained for the past several years, which envelope a wide circle of questions associated with the fabrication, control, and measurement of NV-centers; and with their use as elementary carriers of quantum information. The problem of the construction of a full-scale quantum computer is discussed. © Pleiades Publishing, Ltd.

Panov A.V.,Russian Academy of Sciences
European Physical Journal B | Year: 2012

We theoretically determine the probability distribution function of the net field of the random planar structure of dipoles which represent polarized particles. At small surface concentrations c of the point dipoles this distribution is expressed in terms of special functions. At the surface concentrations of the dipoles as high as 0.6 the dipolar field obey the Gaussian law. To obtain the distribution function within transitional region c < 0.6, we propose the method based on the cumulant expansion. We calculate the parameters of the distributions for some specific configurations of the dipoles. The distribution functions of the ordered ensembles of the dipoles at the low and moderate surface concentrations have asymmetric shape with respect to distribution medians. The distribution functions allow to calculate various physical parameters of two-dimensional interacting nanoparticle ensembles. © EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2012.

Kiselev K.V.,Russian Academy of Sciences
Applied Microbiology and Biotechnology | Year: 2011

The polyphenol trans-resveratrol (3,5,4′-trihydroxy-trans-stilbene) is one of the best known plant secondary metabolites. The number of articles devoted to trans-resveratrol has been steadily increasing. Trans-resveratrol is a molecule that is beneficial to human health; this explains the high level of interest in trans-resveratrol among different research groups. Therefore, it is important to develop an effective method to produce this compound commercially. The applicability of biotechnology for trans-resveratrol extraction is still uncertain. This review describes and compares the available biotechnological methods of trans-resveratrol production, focusing on their advantages and disadvantages. © 2011 Springer-Verlag.

Pogosov W.V.,Russian Academy of Sciences
Journal of Physics Condensed Matter | Year: 2012

It is known that solutions of Richardson equations can be represented as stationary points of the energy of classical free charges on the plane. We suggest considering the probabilities of the system of charges occupying certain states in the configurational space at the effective temperature given by the interaction constant, which goes to zero in the thermodynamical limit. It is quite remarkable that the expression of probability has similarities with the square of the Laughlin wavefunction. Next, we introduce the partition function, from which the ground state energy of the initial quantum-mechanical system can be determined. The partition function is given by a multidimensional integral, which is similar to the Selberg integrals appearing in conformal field theory and random-matrix models. As a first application of this approach, we consider a system with the constant density of energy states at arbitrary filling of the energy interval where potential acts. In this case, the partition function is rather easily evaluated using properties of the Vandermonde matrix. Our approach thus yields a quite simple and short way to find the ground state energy, which is shown to be described by a single expression all over from the dilute to the dense regime of pairs. It also provides additional insight into the physics of Cooper-paired states. © 2012 IOP Publishing Ltd.

Ivantsov A.Y.,Russian Academy of Sciences
Paleontological Journal | Year: 2010

Abstarct: The paper discusses a group of the Late Vendian fossils supposedly related to mollusks. The fossils include imprints with some anatomical characteristics of mollusks, traces resembling scratch marks left by radula, and structures resembling soft shells. Kimberella quadrata, which is represented by all the above kinds of fossils was most likely a trochophore animal of a pre-molluscan evolutionary stage. Remains of Armillifera parva and Solza margarita only slightly resemble shells, and in the absence of the knowledge on the soft body of these animals there are no enongh evidences affiliate them with mollusks. © 2010 Pleiades Publishing, Ltd.

Lukichev A.A.,Russian Academy of Sciences
Journal of Non-Crystalline Solids | Year: 2012

In this study a new graphical method for the dielectric relaxation spectra analysis is presented. The method is based on the graphical determination of characteristic segment values. The Debye, Cole-Cole, Davidson-Cole, Havriliak-Negami distributions are analyzed using the suggested method. The relationships between the segment values and the parameters of distributions are found. The method is more simple and informative in comparison with the Cole-Cole diagram. © 2011 Elsevier B.V. All rights reserved.

Rozhkov A.V.,Russian Academy of Sciences
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

It is known that many-body correlations qualitatively modify the properties of a one-dimensional metal. However, for a quasi-one-dimensional metal these correlations are suppressed, at least partially. We study conditions under which the one-dimensional effects significantly influence the dimensional crossover of a quasi-one-dimensional metal. It is proved (i) that even a system with very high anisotropy of the single-particle hopping might behave on both sides of the crossover as an ordinary weakly nonideal Fermi gas. Further, (ii) to demonstrate well-developed signatures of one-dimensional correlations the system must have extremely (exponentially) high anisotropy. Between cases (i) and (ii) an intermediate regime lies: (iii) the one-dimensional phenomena affect the two-particle susceptibilities, but do not reveal themselves in single-particle quantities. Unlike the normal state properties, (iv) the ordering transition is always very sensitive to the anisotropy: the mean field theory quickly becomes invalid as the anisotropy increases. An expression for the transition temperature is derived. The attributes (i)-(iv) are used to classify the weakly interacting quasi-one-dimensional fermion systems. © 2012 American Physical Society.

Surzhikov S.T.,Russian Academy of Sciences
Journal of Heat Transfer | Year: 2012

To design space vehicles aimed for returning payloads from a geostationary orbit, the Moon and other large or small planets of Solar system, a knowledge of the total (convective and radiative) heating from an environment is required. It is well known that the radiative heat load on a space vehicle moving through the atmosphere increases as the speed and the size increase, therefore, in many of these missions the large part of the trajectory will pass at high altitude, where the low atmospheric density can lead to significant thermal, chemical and physical nonequilibrium effects. Physical models and computational codes used to predict the aerothermodynamics must account for not only high temperature equilibrium thermodynamics (as a rule, within the framework of the local thermodynamic equilibrium (LTE) approach), but also for nonequilibrium one. Therefore, an accurate prediction of radiative heating as well as convective one under both equilibrium and nonequilibrium conditions becomes important to designers and space mission planners. To develop a prediction computational fluid dynamics (CFD) tool for reentry flows, where dissociation, ionization and radiation are important, some major areas are addressed. The most significant of them are following: (1) physical-chemical kinetics of high temperature dissociated and ionized gases, (2) transport properties of the gas mixtures, (3) spectral radiation properties of high temperature gases and low-temperature plasmas, (4) numerical simulation algorithms for prediction of nonequilibrium gas mixtures dynamics and radiation heat transfer in volumes of various geometry, and (5) models of physical and chemical processes accompanied by interaction of gas flows and radiation with thermoprotection systems (TPS) of space vehicles (including their thermochemical destruction, ablation, sublimation, etc.). In literatures (See Refs. (Park, C, 1990, Nonequilibrium Hypersonic Aerothermodynamics, Willey-Interscience Publication, J. Wiley & Sons, New York; Park, C., 1993, "Review of Chemical Kinetic Problems of Future NASA Missions. I: Earth Entries", J. Thermophys. Heat Transfer, 7(3), pp. 385-398; Park, 1994, "Review of Chemical-Kinetic Problems of Future NASA Missions, II: Mars Entries", J. Thermophys. Heat Transfer, 8(1), pp. 9-23; Sarma, G., 2000, "Physico-Chemical Modelling in Hypersonic Flow Simulation," Prog. Aerosp. Sci., 36, pp. 281-349; Huo, and Thuemmel, 1995, Electron-Air Molecule Collisions in Hypersonic Flows. Molecular Physics and Hypersonic Flows, Capitelli M., ed., Kluwer Academic Publishers, pp. 115-138.)) one can find reviews of governing equations used in the aerophysics, boundary conditions and the associated inputs using the physical-chemical models and their partially successful applications. This article presents the states of the art of models of electronic kinetics in the nonequilibrium low-temperature plasma of complex chemical compositions (air and carbon dioxide mixtures) widely met in various aerospace applications. Special attention is given to electronic kinetics of atoms and diatomic molecules within the framework of the radiative-collisional models. © 2012 American Society of Mechanical Engineers.

Lozovik Y.E.,Moscow Institute of Physics and Technology | Ogarkov S.L.,National Research Nuclear University | Sokolik A.A.,Russian Academy of Sciences
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

Condensation of pairs formed by spatially separated electrons and holes in a system of two isolated graphene layers is studied beyond the mean-field approximation. Suppression of the screening of the pairing interaction at large distances, caused by the appearance of the gap, is considered self-consistently. A mutual positive feedback between the appearance of the gap and the enlargement of the interaction leads to a sharp transition to a correlated state with a greatly increased gap above some critical value of the coupling strength. At a coupling strength below the critical value, this correlation effect increases the gap approximately by a factor of 2. The maximal coupling strength achievable in experiments is close to the critical value. This indicates the importance of correlation effects in closely spaced graphene bilayers at weak substrate dielectric screening. Another effect beyond the mean-field approximation considered is the influence of vertex corrections on the pairing, which is shown to be very weak. © 2012 American Physical Society.

Korshunov S.E.,Russian Academy of Sciences
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

The phase diagram of the fully frustrated XY model on a honeycomb lattice is shown to incorporate three different ordered phases. In the most unusual of them, a long-range order is related not to the dominance of a particular periodic vortex pattern but to the orientation of the zero-energy domain walls separating domains with different orientations of vortex stripes. The phase transition leading to the destruction of this phase can be associated with the appearance of free fractional vortices and is of the first order. The stabilization of the two other ordered phases (existing at lower temperatures) relies on a positive contribution to the domain-wall free energy induced by the presence of spin waves. This effect has a substantial numerical smallness, in accordance with which these two phases can be observed only in the systems of really macroscopic sizes. In physical systems (like magnetically frustrated Josephson junction arrays and superconducting wire networks), the presence of additional interactions must lead to a better stabilization of a phase with a long-range order in terms of vortex pattern and improve the possibilities of its observation. © 2012 American Physical Society.

Korshunov S.E.,Russian Academy of Sciences
Physical Review B - Condensed Matter and Materials Physics | Year: 2012

The quantum antiferromagnetic spin-1/2 Ising model on a triangular lattice and analogous fully frustrated Ising model on a square lattice with quantum fluctuation induced by the application of the transverse magnetic field are studied at finite temperatures by constructing an exact mapping onto a purely classical model with a more complex interaction. It is shown that in weak fields the temperatures of the phase transitions separating the critical phase from the ordered and disordered phases in both models are proportional to the magnitude of the field. © 2012 American Physical Society.

Sobol' I.M.,Russian Academy of Sciences | Kucherenko S.,Imperial College London
Computer Physics Communications | Year: 2010

A new derivative based criterion τ y for groups of input variables is presented. It is shown that there is a link between global sensitivity indices and the new derivative based measure. It is proved that small values of derivative based measures imply small values of total sensitivity indices. However, for highly nonlinear functions the ranking of important variables using derivative based importance measures can be different from that based on the global sensitivity indices. The computational costs of evaluating global sensitivity indices and derivative based measures, are compared and some important tests are considered. © 2010 Elsevier B.V. All rights reserved.

Ivanov B.A.,Russian Academy of Sciences | Melosh H.J.,Purdue University
Journal of Geophysical Research E: Planets | Year: 2013

We numerically modeled the formation of Rheasilvia crater, an enormous impact basin centered on asteroid 4 Vesta's south pole. Using a trial and error method, our models were adjusted to produce the best possible fit to Rheasilvia's size and shape, as observed during the Vesta orbital stage of the Dawn mission. The final model yields estimates of the shock wave decay, escaped material volume, depth of excavation, and other relevant characteristics, to the extent allowed by the two-dimensional (axially symmetric) approximation of the Simplified Arbitrary Lagrangian Eulerian hydrocode. Our model results permit interpretation of the Dawn data on Vesta's shape, topographic crater profiles, and the origin of the Vestoid asteroid family as escaped ejecta from the Rheasilvia crater. Key Points The numerical model is fitted to reproduce Rheasilvia crater size and shape We estimate shock decay, escaped mass, and excavation depth We analyze the Rheasilvia crater formation over the older Veneneia basin ©2013. American Geophysical Union. All Rights Reserved.

It is usually believed that angular aperture of seismic data should be at least 20° to allow estimation of the subsurface anisotropy. Although this is certainly true for reflection data, for which anisotropy parameters are inverted from the stacking velocities or the nonhyperbolic moveout, traveltimes of direct P- and S-waves recorded in typical downhole microseismic geometries make it possible to infer seismic anisotropy in angular apertures as narrow as about 10°. To ensure the uniqueness of such an inversion, it has to be performed in a local coordinate frame tailored to a particular data set. Because any narrow fan of vectors is naturally characterized by its average direction, we choose the axes of the local frame to coincide with the polarization vectors of three plane waves corresponding to such a direction. This choice results in a significant simplification of the conventional equations for the phase and group velocities in anisotropic media and makes it possible to predict which elements of the elastic stiffness tensor are constrained by the available data. We illustrate our approach on traveltime synthetics and then apply it to perforation-shot data recorded in a shale-gas field. Our case study indicates that isotropic velocity models are inadequate and accounting for seismic anisotropy is a prerequisite for building a physically sound model that explains the recorded traveltimes. © 2012 Society of Exploration Geophysicists.

Andreev A.F.,Russian Academy of Sciences
Journal of Low Temperature Physics | Year: 2012

A simple model based on the concept of resonant tunneling clusters of lattice defects is used to explain the low temperature anomalies of hcp 4He crystals (mass decoupling from a torsional oscillator, shear modulus anomaly, dissipation peaks, heat capacity peak). Mass decoupling is a result of an internal Josephson effect: mass supercurrent inside phase coherent tunneling clusters. Quantitative results are in reasonable agreement with experiments. © Springer Science+Business Media, LLC 2012.

Kirillov A.S.,Russian Academy of Sciences
Quantum Electronics | Year: 2012

Using the experimental rates of O 2(b 1Σ g +, ν = 1 - 3) quenching by oxygen molecules at different temperatures available from the literature, estimates were made of the parameters for analytical formulas which permit calculating the quenching constants for singlet oxygen. The calculated O 2(b 1Σ g +, ν = 1 - 15) and O 2(a 1Δ g, ν = 1 - 20) constants of quenching by unexcited oxygen molecules for temperatures T = 300 and 155 K are in good agreement with experimental data. The main channels of O 2(a 1Δ g, ν = 0 - 20) and O 2(b 1Σ g +, ν = 0 - 15) quenching by vibrationally excited O 2(X 3Σ g -, ν = 1 - 4) oxygen molecules were investigated. © 2012 Kvantovaya Elektronika and Turpion Ltd.

Preliminary analysis of long-term hydrological data shows that sediment dynamics of Russian Arctic rivers is largely affected by hysteresis effects in relation of water discharge to suspended sediment concentration (SSC). The role of large-scale geomorphic and geocryological conditions in sediment transport is still relatively understudied. This research aims to assess the links between hydrogeomorphology and regularities of sediment formation and movement in Russian Arctic rivers. A dataset containing information on measured water discharges and SSC for 27 gauges on 16 medium and large rivers of the Russian Arctic was used in this research. Clockwise hysteresis is typical during spring events, while in summer counterclockwise and 'figure eight' curves are widely observed. The results show that the form of the rating curve can be attributed to the dominant sediment source, dominant channel pattern and, to certain extent, to the cross-section position within the river basin. Seasonality in hysteresis effects reflects the role frozen ground dynamic plays in sediment flux formation. Thus, reaction of permafrost landscapes on the widely observed climate shift should lead to significant changes in sediment transfer systems. © IWA Publishing 2015.

Prants S.V.,Russian Academy of Sciences
European Physical Journal: Special Topics | Year: 2014

Dynamical systems theory approach has been successfully used in physical oceanography for the last two decades to study mixing and transport of water masses in the ocean. The basic theoretical ideas have been borrowed from the phenomenon of chaotic advection in fluids, an analogue of dynamical Hamiltonian chaos in mechanics. The starting point for analysis is a velocity field obtained by this or that way. Being motivated by successful applications of that approach to simplified analytic models of geophysical fluid flows, researchers now work with satellite-derived velocity fields and outputs of sophisticated numerical models of ocean circulation. This review article gives an introduction to some of the basic concepts and methods used to study chaotic mixing and transport in the ocean and a brief overview of recent results with some practical applications of Lagrangian tools to monitor spreading of Fukushima-derived radionuclides in the ocean. © 2014, EDP Sciences and Springer.

Chibisov A.N.,Russian Academy of Sciences
Materials Letters | Year: 2013

We have used molecular dynamics and first-principles calculations to investigate the structure, electronic properties, and agglomeration of Ti nanoparticles. The results indicate that cluster agglomeration leads to a decrease in the band gap compared with the isolated Ti13 cluster. In addition, we found that titanium nanocluster growth occurred along the [0001] direction. The difference of the atomic structures of the icosahedral Ti 13 cluster and the bulk phase of titanium was also studied. The results show that spin polarization disappears when nanoparticles agglomerate. © 2013 Elsevier B.V. All rights reserved.

Vinogradov A.E.,Russian Academy of Sciences
Journal of Molecular Evolution | Year: 2012

Proteome complexity increases in the evolution mostly by means of gene duplication followed by divergence. In this genome-scale study of human genome I show that density distribution of duplicate gene pairs along the axis of protein divergence between pair members forms two main peaks with a small peak and plateau before the first main peak. This picture indicates the existence of three evolutionary stages of duplicate gene evolution. The analysis of various functional parameters (gene expression level and breadth, transcription factor targets, protein interaction networks) suggests that subfunctionalization (partition of function) is a predominant mode of divergence in the first main peak, whereas neofunctionalization (acquiring of novel functions) prevails in the second main peak. The young duplicate pairs show a much higher expression level compared with singleton genes and more diverged duplicates, which indicates that requirement for high gene dosage is important for retention of duplicates just after the duplication event. Thus, a prevailing route of duplicate evolution seems to be the high gene dosage-subfunctionalization- neofunctionalization. This adaptationist model suggests that an organism is evolving in the direction of its most intensively used functions. © Springer Science+Business Media, LLC 2012.

A dynamic-stochastic approach, which combines a deterministic model of snowmelt runoff formation with a stochastic weather generator, has been proposed. The model describes snow accumulation and melt, vertical heat and moisture transfer in a soil, detention of melt water by the depressions at the catchment surface, overland and channel flow. The weather generator includes stochastic models that produce daily values of precipitation, air temperature, and air humidity during a whole year. Daily weather variables have been simulated by Monte Carlo procedure and transposed to snowmelt flood hydrographs on the basis of continuous simulation by the model of runoff generation. A specific censoring procedure has been developed to select among the generated weather scenarios the ones that can lead to generation of the extremely high floods. The developed procedure makes simulations more efficient and computationally fast. The proposed approach has been used to generate extreme snowmelt floods exceeding the maximum observed flood in the Seim River basin of central European Russia (catchment area, 7460 km2), to estimate their frequencies and, importantly, to assess characteristic conditions of the genesis of such extreme floods. © 2010 Elsevier B.V. All rights reserved.

Blank M.,Russian Academy of Sciences
Journal of Statistical Physics | Year: 2010

A new class of exclusion type processes acting in continuum with synchronous updating is introduced and studied. Ergodic averages of particle velocities are obtained and their connections to other statistical quantities, in particular to the particle density (the so called Fundamental Diagram) is analyzed rigorously. The main technical tool is a "dynamical" coupling applied in a nonstandard fashion: we do not prove the existence of the successful coupling (which even might not hold) but instead use its presence/absence as an important diagnostic tool. Despite that this approach cannot be applied to lattice systems directly, it allows to obtain new results for the lattice systems embedding them to the systems in continuum. Applications to the traffic flows modelling are discussed as well. © 2010 Springer Science+Business Media, LLC.

Gontcharov G.A.,Russian Academy of Sciences
Astronomy Letters | Year: 2012

Multicolor photometry from the Tycho-2 and 2MASS catalogues for 11 990 OB and 30 671 K-type red giant branch stars is used to detect systematic large-scale variations of the interstellar extinction law within the nearest kiloparsec. The characteristic of the extinction law, the total-to-selective extinction ratio Rv, which also characterizes the size and other properties of interstellar dust grains, has been calculated for various regions of space by the extinction law extrapolation method. The results for the two classes of stars agree: the standard deviation of the "red giants minus OB" Rv differences within 500 pc of the Sun is 0. 2. The detected Rv variations between 2. 2 and 4. 4 not only manifest themselves in individual clouds but also span the entire space near the Sun, following Galactic structures. In the Local Bubble within about 100 pc of the Sun, Rv has a minimum. In the inner part of the Gould Belt and at high Galactic latitudes, at a distance of about 150 pc from the Sun, Rv reaches a maximum and then decreases to its minimum in the outer part of the Belt and other directions at a distance of about 500 pc from the Sun, returning to its mean values far from the Sun. The detected maximum of Rv at high Galactic latitudes is important when allowance is made for the interstellar extinction toward extragalactic objects. In addition, a monotonic increase in Rv by 0. 3 per kpc toward the Galactic center has been found near the Galactic equator. It is consistent with the result obtained by Zasowski et al. (2009) for much of the Galaxy. Ignoring the Rv variations and traditionally using a single value for the entire space must lead to systematic errors in the calculated distances reaching 10%. © 2012 Pleiades Publishing, Ltd.

Ksanfomality L.V.,Russian Academy of Sciences
Solar System Research | Year: 2012

New classes of extrasolar planets with relatively small masses ("super-Earths") located in low orbits near low luminosity stars possess moderately high temperature and atmospheric pressure at their surfaces. Such physical conditions and composition of an atmosphere is incompatible with the Earth's aminonucleic acid form of life. But should they be considered as conditions incompatible with any form of life at all? Considering the conditions on Venus as a possible analogue of physical conditions on low-orbiting exoplanets of the "super-Earths" type, a new analysis of Venusian surface panoramas' details has been made. These images were produced by the VENERA landers in 1975 and 1982. Also the images which had not been previously considered were included in the processing. A few relatively large objects were found with size ranging from a decimeter to half meter and with unusual morphology. The objects were observed in some images, but were absent in the other or altered their shape. The article presents the obtained results and analyzes the evidence of reality of these objects. © 2012 Pleiades Publishing, Ltd.

Gontcharov G.A.,Russian Academy of Sciences
Astronomy Letters | Year: 2012

The product of the previously constructed 3D maps of stellar reddening (Gontcharov 2010) and Rv variations (Gontcharov 2012) has allowed us to produce a 3D interstellar extinction map within the nearest kiloparsec from the Sun with a spatial resolution of 50 pc and an accuracy of 0 m.2. This map is compared with the 2D reddening map by Schlegel et al. (1998), the 3D extinction map at high latitudes by Jones et al. (2011), and the analytical extinctionmodels by Arenou et al. (1992) and Gontcharov (2009). In all cases, we have found good agreement and show that there are no systematic errors in the new map everywhere except the direction toward the Galactic center. We have found that the map by Schlegel et al. (1998) reaches saturation near the Galactic equator at E(B - V) > 0. 8, has a zero-point error and systematic errors gradually increasing with reddening, and among the analytical models those that take into account the extinction in the Gould Belt are more accurate. Our extinction map shows that it is determined by reddening variations at low latitudes and Rv variations at high ones. This naturally explains the contradictory data on the correlation or anticorrelation between reddening and Rv available in the literature. There is a correlation in a thin layer near the Galactic equator, because both reddening and Rv here increase toward the Galactic center. There is an anticorrelation outside this layer, because higher values of Rv correspond to lower reddening at high and middle latitudes. Systematic differences in sizes and other properties of the dust grains in different parts of the Galaxy manifest themselves in this way. The largest structures within the nearest kiloparsec, including the Local Bubble, the Gould Belt, the Great Tunnel, the Scorpius, Perseus, Orion, and other complexes, have manifested themselves in the constructed map. © 2012 Pleiades Publishing, Ltd.

Malkin A.Y.,Russian Academy of Sciences
Journal of Non-Newtonian Fluid Mechanics | Year: 2013

Different possible mechanisms of non-Newtonian behavior of polymeric and multi-component materials in shearing are discussed. There are two main types of the non-Newtonian media: fluids with the maximal (zero-shear-rate) Newtonian viscosity and yielding visco-plastic materials. Numerous intermediate and superimposing situations can also exist. The main concept of the non-Newtonian viscosity of such elastic fluids as polymer melts is based on definition of their "structure" as the set of relaxation modes modified by deformation. Shear-induced relaxation spectrum transformations lead to non-linearity, formation of anisotropic structures, and changes in the macromolecule entanglement topology. A general approach to quantitative description of non-Newtonian flow of polymer melts is achieved if to assume that the dominant reason of non-linear flow properties is molecular-weight distribution of polydisperse polymers with continuous flow-to rubbery transition from the side of slow relaxation modes with increasing shear rate. The non-Newtonian viscosity of such multi-component systems as numerous suspensions, emulsions, and mixtures is characterized by transition from the flow curves with the zero-shear-rate viscosity to the yield-type behavior. The latter is the direct evidence of a spatial structure which changes in shearing. The yield stress value can be rigorously determined only for rigid structures. For soft matters, the structural breakdown/buildup processes are a time dependent (thixotropic/rheopectic) phenomenon, and the concept of yielding becomes uncertain. Nature of structures in various multi-component materials can be very different but just their existence determines a possibility of non-linear effects in shearing. A special type of the non-Newtonian flow is instability and inhomogeneity of a stream. Different forms of these phenomena (shear banding, layered flow, surface distortions, periodic oscillations, concentration separation, and movement of large structural aggregates) are known. In such situations, the "measured" non-Newtonian viscosity can appear an artifact depending on the size factor. © 2012 Elsevier B.V.

Ivanova E.P.,Russian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

A new-generation x-ray laser project is explained. It is based on the transitions in Pd-like ions in nanoplasmas. The gain coefficient is calculated for the 4d3/295d3/2[J=0]-4d3/295p1/2[J=1] transition (λ10.8 nm) in Pd-like tungsten. It is suggested that a cylindrical target made of nanostructured tungsten is pumped in the longitudinal direction by a laser pulse with energy 1-2 keV and duration ∼500 ps. For this pump pulse the target density and dimensions are calculated, as well as the temporal variations of the optimal plasma parameters for attaining gL ∼ 14. The energy yield in the 10.8-nm line is more than 1020 eV. © 2010 The American Physical Society.

Borisenkov M.F.,Russian Academy of Sciences
Chronobiology International | Year: 2011

Recently, it was shown that the sleep-wake rhythm of the inhabitants of the temperate zone is entrained to sun time. In the North, significant seasonal changes in the photoperiod may interfere with entrainment of the circadian system to sunlight. This investigation assessed the influence of photoperiod characteristics on the sleep length and sleep-wake rhythm of residents of high latitude. The study was conducted in four towns and six villages located between 59.5°N and 67.6°N latitude between the months of October and May from 2009 through 2011 and included 2822 subjects aged 10 to 97 yrs, 1621 of whom were females and 1201 males. The chronotype and sleep length of the subjects were assessed using the Munich Chronotype Questionnaire. The instructions for the questionnaire stressed the need to specify the sleep-wake schedule during the week preceding the date of completing the questionnaire. The study found that the length of sleep and the chronotype of the inhabitants surveyed in Northern European Russia depend on age, sex, type of settlement, and place of residence. The time of sunrise was a stronger predictor of sleep length and chronotype than the time of sunset and day length. A later chronotype and shorter sleep length were found for the subjects during the equinox (sunrise at 06:00h) than under long-photoperiod conditions (sunrise at 04:0005:00h). During short-photoperiod conditions (sunrise at 07:0010:00h), no significant changes in the self-reported sleep-wake rhythm were found. The time of sunrise had the strongest impact on the sleep-wake rhythm of 30- to 97-yr-old persons. Sunrise had a stronger influence on chronotype and sleep length in January to May, when the days become longer, than in October to December, when the days become shorter. Age- and season-associated changes were found in the entrainment of the sleep-wake rhythm by photoperiod in the North. © Informa Healthcare USA, Inc.

Polyanin A.D.,Moscow State Technical University | Zhurov A.I.,Russian Academy of Sciences
International Journal of Non-Linear Mechanics | Year: 2014

We present a number of new generalized separable, functional separable, periodic and antiperiodic exact solutions to non-linear delay reaction-diffusion equations of the formut=kuxx+F(u,w),where u=u(x,t) and w=u(x,t-τ), with τ being the delay time. The generalized separable solutions are sought in the form u=Σn=1NΦn(x) Ψn(t), with the functions Φn(x) and Ψn(t) to be determined in the analysis. Most of the equations considered contain one or two arbitrary functions of a single argument or one arbitrary function of two arguments of special form. All solutions involve free parameters (in some cases, infinitely many parameters) and so can be suitable for solving certain problems and testing approximate analytical and numerical methods for non-linear delay PDEs. Some results are extended to non-linear delay partial differential equations of any order. © 2013 Elsevier Ltd.

Kalverda B.,Netherlands Cancer Institute | Pickersgill H.,Netherlands Cancer Institute | Shloma V.V.,Russian Academy of Sciences | Fornerod M.,Netherlands Cancer Institute
Cell | Year: 2010

Nuclear pore complexes (NPCs) mediate transport across the nuclear envelope. In yeast, they also interact with active genes, attracting or retaining them at the nuclear periphery. In higher eukaryotes, some NPC components (nucleoporins) are also found in the nucleoplasm, with a so far unknown function. We have functionally characterized nucleoporin-chromatin interactions specifically at the NPC or within the nucleoplasm in Drosophila. We analyzed genomic interactions of full-length nucleoporins Nup98, Nup50, and Nup62 and nucleoplasmic and NPC-tethered forms of Nup98. We found that nucleoporins predominantly interacted with transcriptionally active genes inside the nucleoplasm, in particular those involved in developmental regulation and the cell cycle. A smaller set of nonactive genes interacted with the NPC. Genes strongly interacting with nucleoplasmic Nup98 were downregulated upon Nup98 depletion and activated on nucleoplasmic Nup98 overexpression. Thus, nucleoporins stimulate developmental and cell-cycle gene expression away from the NPC by interacting with these genes inside the nucleoplasm. © 2010 Elsevier Inc. All rights reserved.

Pollock M.D.,Russian Academy of Sciences
Acta Physica Polonica B | Year: 2010

We discuss in detail the general-relativistically covariant Dirac equation derived by Fock for a particle of rest mass m and charge e in an electromagnetic potential Ai, [iγk(∂k -F k- ieAk) - m]ψ = 0. The spinorial affine connection is given in terms of the spin connection ωabi and spin operator s̄ab by the formula Fi = - ωabiS̄ab/4, which follows from the assumption that the curved-space gamma matrices γi are covariantly constant, and which we prove to be equivalent to the 'tetrad postulate' of van Nieuwenhuizen, that the tetrad ti a is covariantly constant. The intermediate result that γkFiγ k = 0 is also proven. Extension to dimensionality D is straightforward, and results in the formula F̂I = -ω̂abIs̄̂ab /4 for the spinorial connection. Reduction of the five-dimensional Dirac equation to four dimensions has been shown by Klein, in the approximation linear in Ai, to yield in addition an anomalous Pauli mass term 1/2i√πGN F ijsij, which produces a correction to the intrinsic magnetic moment of the electron by the factor (1+δ), where δ = - √1/αm/Mp = -4.90′10-22, of theoretical interest but beyond the range of current experiment. We also discuss the TCP theorem in curved space-time, with particular reference to the heterotic sxiperstring theory of Gross et al., in the expanding Friedmann Universe. Previously, we have established the interrelationship between non-invariance of the metric under T, defined with regard to comoving time by t -t, due to general relativity, and non-invariance of the superstring under P, due to the asymmetric construction of the world sheet, which contains only right-moving Majorana fermions, while TP is conserved. This motivates study of C and the dimensional fermionic existence conditions found by van Nieuwenhuizen, Chapline and Slansky, Wetterich and Gliozzi et al.

Konopsky V.N.,Russian Academy of Sciences
New Journal of Physics | Year: 2010

The propagation of bound optical waves along the surface of a one-dimensional (1D) photonic crystal (PC) structure is considered. A unified description of the waves in 1D PCs for both s-and p-polarizations is done via an impedance approach. A general dispersion relation that is valid for optical surface waves with both polarizations is obtained, and conditions are presented for long-range propagation of plasmon-polariton waves in nanofilms (including lossy ones) deposited on the top of the 1D PC structure. A method is described for designing 1D PC structures to fulfill the conditions required for the existence of the surface mode with a particular wavevector at a particular wavelength. It is shown that the propagation length of the long-range surface plasmon polaritons in a thin metal film can be maximized by wavelength tuning, which introduces a slight asymmetry in the system. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Liseykina T.V.,University of Rostock | Liseykina T.V.,Russian Academy of Sciences | Bauer D.,University of Rostock
Physical Review Letters | Year: 2013

We study the ionization dynamics in intense laser-droplet interaction using three-dimensional, relativistic particle-in-cell simulations. Of particular interest is the laser intensity and frequency regime for which initially transparent, wavelength-sized targets are not homogeneously ionized. Instead, the charge distribution changes both in space and in time on a subcycle scale. One may call this the extreme nonlinear Mie-optics regime. We find that - despite the fact that the plasma created at the droplet surface is overdense - oscillating electric fields may penetrate into the droplet under a certain angle, ionize, and propagate in the just generated plasma. This effect can be attributed to the local field enhancements at the droplet surface predicted by standard Mie theory. The penetration of the fields into the droplet leads to the formation of a highly inhomogeneous charge density distribution in the droplet interior, concentrated mostly in the polarization plane. We present a self-similar, exponential fit of the fractional ionization degree which depends only on a dimensionless combination of electric field amplitude, droplet radius, and plasma frequency with only a weak dependence on the laser frequency in the overdense regime. © 2013 American Physical Society.

Shevchenko I.I.,Russian Academy of Sciences
Astrophysical Journal | Year: 2011

We estimate the Lyapunov times (characteristic times of predictability of motion) in Quillen's models for the dynamics in the solar neighborhood. These models take into account perturbations due to the Galactic bar and spiral arms. For estimating the Lyapunov times, an approach based on the separatrix map theory is used. The Lyapunov times turn out to be typically of the order of 10 Galactic years. We show that only in a narrow range of possible values of the problem parameters the Galactic chaos is adiabatic; usually it is not slow. We also estimate the characteristic diffusion times in the chaotic domain. In a number of models, the diffusion times turn out to be small enough to permit migration of the Sun from the inner regions of the Milky Way to its current location. Moreover, due to the possibility of ballistic flights inside the chaotic layer, the chaotic mixing might be even far more effective and quicker than in the case of normal diffusion. This confirms the dynamical possibility of Minchev and Famaey's migration concept. © 2011. The American Astronomical Society. All rights reserved..

Leinson L.B.,Russian Academy of Sciences
Physical Review C - Nuclear Physics | Year: 2010

Neutrino energy losses through neutral weak currents in the triplet-spin superfluid neutron liquid are studied for the case of condensate involving several magnetic quantum numbers. Low-energy excitations of the multicomponent condensate in the timelike domain of the energy and momentum are analyzed. Along with the well-known excitations in the form of broken Cooper pairs, the theoretical analysis predicts the existence of collective waves of spin density in the one-component condensate at very low energy. Because of a rather small excitation energy of spin waves, their decay leads to a substantial neutrino emission at the lowest temperatures when all other mechanisms of neutrino energy loss are killed by a superfluidity. Neutrino energy losses caused by the pair recombination and spin-wave decays are examined in all of the multicomponent phases that might represent the ground state of the condensate, according to modern theories, and for the case when a phase transition occurs in the condensate at some temperature. Our estimate predicts a sharp increase in the neutrino energy losses followed by a decrease, along with a decrease in the temperature that takes place more rapidly than it would without the phase transition. We demonstrate the important role of the neutrino radiation caused by the decay of spin waves in the cooling of neutron stars. © 2010 The American Physical Society.

Lukichev A.A.,Russian Academy of Sciences
Chemical Physics | Year: 2014

This study presents the new relaxation function describing the non-Debye relaxation phenomena. The relaxation function is based on a new theoretical model of the relaxation polarization. The non-Debye relaxation is explained with the model of nonlinear damped oscillator. It is shown that the relaxation function describes the relaxation spectra of the Davidson-Cole and Havriliak-Negami types as well as spectra with the left-skewed loss peak. © 2013 Elsevier B.V. All rights reserved.

Leven E.J.,Russian Academy of Sciences
Stratigraphy and Geological Correlation | Year: 2010

Fusulinids from the Rosh Gol, Mastuj, Reshun Gol (East Hindu Kush) and Baroghil (West Karakorum) localities are studied. Five successive fusulinid assemblages from the Rosh Gol section characterize the Sakmarian (?), Yakhtashian-Bolorian, and Kubergandian stages of the Permian. Fusulinids of the Sakmarian (?) Stage are discovered in the Baroghil locality. In the Mastuj and Reshun Gol localities, rocks of natural outcrops, talus cones, and pebbles of the Cretaceous conglomerates yield predominantly the Kubergandian fusulinids accompanied sometimes by the Sakmarian (?) and Bolorian forms. Four new species Monodiexodina talenti, Nonpseudofusulina conaghani, N. yarkhunensis, and N. mawsoni are described. © 2010 Pleiades Publishing, Ltd.

Peretyazhko I.S.,Russian Academy of Sciences
Petrology | Year: 2010

Analysis the development of large fluid segregations in a flux of small fluid bubbles during the degassing of granitic (pegmatitic) melts indicates that the velocity of the buoyant ascent of fluid bubbles depends on their sizes, the viscosity and density of the melts, and the duration of melt flow. Possible variants of the primary and secondary boiling of magma are discussed depending on the P-T conditions and concentrations of H2O, F, B, and other components dissolved in the magma. The possible density ranges of the fluid phases are considered, along with the viscosity and density of granitic (pegmatitic) melts, velocities of the buoyant ascent of fluid bubbles in them, and the processes of their coalescence and accumulation in the temperature range of 650-850°C. Provisional evaluates are obtained for the duration of melt crystallization and the development of intrusive massifs and dikes of granites and syngenetic intragranite and epigenetic (intruded into the host rocks) granite pegmatites. Simulation data and geological observations suggest that large fluid segregations were formed already in the magma chambers in which the heterogeneous granite (pegmatitic) magma was derived, before its emplacement into the host rocks. These generation regions could be magma chamber areas within granite intrusions, in which melts enriched in volatiles were accumulated and then degassed with the release of fluid phases of various composition and density. The crystallization of fluid-rich melts under favorable conditions gives rise to granites with miarolitic structures. The emplacement of heterogeneous pegmatitic magma (which consists of immiscible silicate melts and large fluid segregations) into the host rocks results in that these segregations (would-be miaroles) occur in any part of the pegmatite-hosting chamber. This explains why miaroles of significantly different composition and with broadly varying proportions of their filling minerals may occur in various parts of pegmatite veins or their swells, as well as near contacts with the host rocks. © Pleiades Publishing, Ltd., 2010.

Sokolov S.D.,Russian Academy of Sciences
Geotectonics | Year: 2010

The tectonic units of the Verkhoyansk-Chukotka Mesozoides and the Koryak-Kamchatka Fold Region substantially differ from each other in the structure and composition of terranes. The geodynamic settings of terrane formation are defined and the main stages of their tectonic history are reconstructed. The formation of Mesozoides was mainly controlled by collision, largely between the continent and the Kolyma-Omolon and Chukchi microcontinents. The accretionary structure of the Koryak Highland comprises various terranes transported by Pacific plates and docked to the Asian continent, periodically accreting its margin. The following evolutionary stages are established: destruction of the North Asian continent (Ordovician, Late Devonian-Early Carboniferous, Permian-Triassic); amalgamation (Middle Jurassic for Kolyma and Mid-Cretaceous for Koryak terranes); collision (terminal Early Cretaceous); and continental growth (terminal Early Cretaceous, terminal Late Cretaceous, middle Eocene). © 2010 Pleiades Publishing, Ltd.

Jones V.,University College London | Solomina O.,Russian Academy of Sciences
Global and Planetary Change | Year: 2015

This paper briefly reviews the physical and human geography of the Kamchatka region and summarises previous research on Holocene climate dynamics. We provide context for the rest of the Special Issue of the Journal Global and Planetary Change entitled 'Holocene climate change in Kamchatka', the primary focus of which is the use of lake sediment records for palaeoclimatic inferences. In this paper an additional perspective from ongoing tree ring, ice core and borehole temperature reconstructions illustrates that the Kamchatka region is rich in paleoclimatic proxies. The period of the last 200 years is sufficiently covered by the proxy information, including reconstructions with annual resolution. In this period the tree-rings, ice cores, boreholes, and glacier fluctuations recorded a 1. °C warming and a general glacier retreat, i.e. the transition from the Little Ice Age climate to the modern one. Although the proxies have different resolution, accuracy and seasonality in general they demonstrate a coherent picture of environmental changes in the last two centuries. The tree ring and ice core records are up to four-six hundred years long and they provide information on annual to decadal variability of summer temperature, accumulation processes, volcanic eruptions and lahar activity. © 2015 The Authors.

Shustov B.M.,Russian Academy of Sciences
Physics-Uspekhi | Year: 2011

The asteroid-comet hazard (ACH) has attracted attention from scientists, technicians, and the general public, both globally and in Russia. While until the mid-1990s hazardous objects were detected either by chance or within individual asteroid/comet research programs, the launch in 1998 of the Space-guard Survey program supported by the U.S. Congress, enabled detection at a much higher rate. About 8,000 NEOs (near earth objects) had been discovered as of mid-April 2011. Most of this number are asteroids; a few comets are a class of minor bodies which are very difficult to observe. Radar observations of asteroids are of a great value not only in providing very accurate information on the orbital motion of an asteroid but also in providing data on its physical properties, such as size, shape, and the composition of surface layers. Assessing the degree of threat is a crucial component of the ACH problem, because the underassessment or over-assessment of risk leads to devastating consequences or huge material and social losses.

Ronquist F.,Swedish Museum of Natural History | Klopfstein S.,Swedish Museum of Natural History | Vilhelmsen L.,Universitetsparken 15 | Schulmeister S.,Ludwig Maximilians University of Munich | And 2 more authors.
Systematic Biology | Year: 2012

Phylogenies are usually dated by calibrating interior nodes against the fossil record. This relies on indirect methods that, in the worst case, misrepresent the fossil information. Here, we contrast such node dating with an approach that includes fossils along with the extant taxa in a Bayesian total-evidence analysis. As a test case, we focus on the early radiation of the Hymenoptera, mostly documented by poorly preserved impression fossils that are difficult to place phylogenetically. Specifically, we compare node dating using nine calibration points derived from the fossil record with total-evidence dating based on 343 morphological characters scored for 45 fossil (4 - 20 complete) and 68 extant taxa. In both cases we use molecular data from seven markers (∼5 kb) for the extant taxa. Because it is difficult to model speciation, extinction, sampling, and fossil preservation realistically, we develop a simple uniform prior for clock trees with fossils, and we use relaxed clock models to accommodate rate variation across the tree. Despite considerable uncertainty in the placement of most fossils, we find that they contribute significantly to the estimation of divergence times in the total-evidence analysis. In particular, the posterior distributions on divergence times are less sensitive to prior assumptions and tend to be more precise than in node dating. The total-evidence analysis also shows that four of the seven Hymenoptera calibration points used in node dating are likely to be based on erroneous or doubtful assumptions about the fossil placement. With respect to the early radiation of Hymenoptera, our results suggest that the crown group dates back to the Carboniferous, ∼309 Ma (95 interval: 291 - 347 Ma), and diversified into major extant lineages much earlier than previously thought, well before the Triassic. [Bayesian inference; fossil dating; morphological evolution; relaxed clock; statistical phylogenetics.] © 2012 The Author(s).

Molotkov I.A.,Russian Academy of Sciences
Russian Journal of Mathematical Physics | Year: 2010

The Maslov distribution for a system of identical particles is used. The entropy and some other thermodynamical characteristics of this system are found for diverse fractal dimensions. A general formula for the entropy is established, which shows that the entropy is proportional to the derivative of the system energy with respect to the temperature. It is shown that a parastatistical parameter b, which is introduced formally, is related to the temperature of the system indeed. The nature of the phase transition in the system is studied in the two-dimensional case. © 2010 Pleiades Publishing, Ltd.

Maslov V.P.,Russian Academy of Sciences
Russian Journal of Mathematical Physics | Year: 2010

In the paper, the binodal, which describes the density jump, is constructed in another way, by using the fact that the pressure in the liquid and gaseous phases coincides. The process of vitrifying the fluid, which leads to a hypothetical λ-point, is studied by using a new distribution constructed by the author in the previous paper [V. P. Maslov, "Solution of the Gibbs Paradox Using the Notion of Entropy as a Function of the Fractal Dimension," Russ. J. Math. Phys. 17 (3), 251-261 (2010)]. The application of the theory to a rather small number of particles (of the order of million) is also considered. © 2010 Pleiades Publishing, Ltd.

Makarkin V.N.,Russian Academy of Sciences
Annales de la Societe Entomologique de France | Year: 2010

Two new genera and five new species of the psychopsoid Neuroptera (one of which is unnamed) are described from the Early Cretaceous locality at Baissa, Transbaikalia, Russia: Epipsychopsis fusca n. gen., n. sp., E. variegata n. sp. (Psychopsidae), Pseudopsychopsisgradata n. gen., n. sp., P. baissensis n. sp. (Brongniartiellidae), and Sophogramma sp. (Kalligrammatidae).

The morphology of the mandible and stomach lateralia in some Lake Baikal amphipods has been investigated in regard to their food preference. Six species of endemic amphipods with different life styles (so-called "life forms") have been studied by means of light and scanning electron microscopy. The modifications of the mandible are attributed to the food resources used. The position of the incisor and lacinia mobilis, their width and length, the structure of the triturative area of the molar, the wearing of incisor and lacinia mobilis between two moults, and the relative length of the stomach depend on the type of food. None of the species studied revealed complete reduction of any part of the mandible. The most specialized species are the oophage Pachyschesis bazikalovae G. Karaman, 1976, the necrophage Ommatogammarus albinus (Dybowsky, 1874), and a species biting holes in sponges with a siliceous skeleton, Eulimnogammarus violaceus (Dybowsky, 1874). The morphology of the lateralia seems not to be connected with the food type, but is probably important from a phylogenetic point of view. © 2010 Koninklijke Brill NV, Leiden.

Kolomak E.A.,Russian Academy of Sciences
Regional Research of Russia | Year: 2011

An empirical test is conducted for a model in which spatial externalities generated by regional economic growth are considered a source of development of neighboring territories. Our estimates based on the data on Russian regions show that these externalities do affect other regions' growth rates, but the pattern of this effect in the western regions of Russia differs from the one observed in the eastern regions. © Pleiades Publishing, Ltd., 2011. Original Russian Text © E.A. Kolomak, 2010.

Shelkovnikova T.A.,University of Cardiff | Shelkovnikova T.A.,Russian Academy of Sciences
Biochemical Society Transactions | Year: 2013

The discovery of a causative link between dysfunction of a number of RNA-binding proteins with prionlike domains and the development of certain (neuro)degenerative diseases has completely changed our perception of molecular mechanisms instigating pathological process in these disorders. Irreversible aggregation of these proteins is a crucial pathogenic event delineating a type of proteinopathy. FUS (fused in sarcoma) is a prototypical member of the class, and studies into the causes and consequences of FUSopathies have been instrumental in characterizing the processes leading to deregulation of RNA metabolism in neurodegeneration. In vivo models of FUSopathy have provided critical insights into the mechanisms of FUS toxicity and clues on the role of non-amyloid aggregates, which are hallmarks of these diseases. The present review summarizes the data on FUS aggregation signatures in available model organisms on the basis of overexpression of FUS variants. © 2013 Biochemical Society.

Shevchenko I.I.,Russian Academy of Sciences
Astrophysical Journal | Year: 2015

The extent of the continuous zone of chaotic orbits of a small-mass tertiary around a system of two gravitationally bound primaries of comparable masses (a binary star, a binary black hole, a binary asteroid, etc.) is estimated analytically, as a function of the tertiary's orbital eccentricity. The separatrix map theory is used to demonstrate that the central continuous chaos zone emerges (above a threshold in the primaries' mass ratio) due to overlapping of the orbital resonances corresponding to the integer ratios p:1 between the tertiary and the central binary periods. In this zone, the unlimited chaotic orbital diffusion of the tertiary takes place, up to its ejection from the system. The primaries' mass ratio, above which such a chaotic zone is universally present at all initial eccentricities of the tertiary, is estimated. The diversity of the observed orbital configurations of biplanetary and circumbinary exosystems is shown to be in accord with the existence of the primaries' mass parameter threshold. © 2015. The American Astronomical Society. All rights reserved.

Burinskii A.,Russian Academy of Sciences
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2016

We consider the chiral field model of the source of the Kerr-Newman (KN) solution and obtain that it represents a supersymmetric spinning soliton, bounded by the chiral domain wall (DW) of the ellipsoidal form. The known method for transformation of the planar DW to Bogomolnyi form we generalize to the curved DW-bubble adapted to the Kerr coordinate system and obtain the supersymmetric BPS-saturated source of the KN solution, having some remarkable features, in particular, the quantum angular momentum. The main new result is that the source forms a breather, i.e. the DW-antiDW combination. Taking into account that the KN solution describes the spinning particles with gyromagnetic ratio g=. 2, as that of the Dirac electron, we touch the problem of the compatibility of the spinning particles with gravity. © 2016 The Author.

Revich B.,Russian Academy of Sciences
International journal of circumpolar health | Year: 2012

Climate change in the Russian Arctic is more pronounced than in any other part of the country. Between 1955 and 2000, the annual average air temperature in the Russian North increased by 1.2°C. During the same period, the mean temperature of upper layer of permafrost increased by 3°C. Climate change in Russian Arctic increases the risks of the emergence of zoonotic infectious diseases. This review presents data on morbidity rates among people, domestic animals and wildlife in the Russian Arctic, focusing on the potential climate related emergence of such diseases as tick-borne encephalitis, tularemia, brucellosis, leptospirosis, rabies, and anthrax.

Motohashi H.,University of Tokyo | Starobinsky A.A.,University of Tokyo | Starobinsky A.A.,Russian Academy of Sciences | Yokoyama J.,University of Tokyo
Physical Review Letters | Year: 2013

It is shown that the tension between recent neutrino oscillation experiments, favoring sterile neutrinos with masses of the order of 1 eV, and cosmological data which impose stringent constraints on neutrino masses from the free streaming suppression of density fluctuations, can be resolved in models of the present accelerated expansion of the Universe based on f(R) gravity. © 2013 American Physical Society.

Khalaim A.I.,Russian Academy of Sciences
African Invertebrates | Year: 2013

Thirteen Afrotropical species of the ichneumonid genus Diaparsis are recognised (including one species from Seychelles and one species from Reunion). Eleven new species are described from Gabon, Tanzania, South Africa and Uganda: D. abstata sp. n., D. aneucliformis sp. n., D. interstitialis sp. n., D. inusitata sp. n., D. kolyadai sp. n., D. minuscula sp. n., D. mostovskii sp. n., D. probleformis sp. n., D. robusta sp. n., D. voluptuosa sp. n. and D. vulgaris sp. n. Two previously known species, D. evanescens (Morley, 1912) and D. moesta (Holmgren, 1868), are re-described following re-examination of their types. The latter species is found to belong to the genus Tersilochus Holmgren, 1859 (subgenus Tersilochus s. str.), in which it was originally described. An identification key to 13 Afrotropical species of Diaparsis is provided.

Sobolev G.A.,Russian Academy of Sciences
Izvestiya, Physics of the Solid Earth | Year: 2013

The records from wideband seismic stations are analyzed for studying the oscillations of the Earth that emerged after the earthquakes in Sumatra on December 26, 2004 (M = 9.2), Chile on February 27, 2010 (M = 8.8), and after the Tohoku megaearthquake on March 11, 2011 (M = 9.0). Attention is focused on the band with a period of 20.46 min, which includes the free radial mode 0S0. It is established that the emergence of oscillations in the frequency interval corresponding to the free oscillations of the Earth is delayed by a lag, which increases with increasing period. Pulsations of the 20.46-min band, which appear in the interval from 5 to 7 days after the earthquake and have a period of 127-129 min, are revealed. The patterns of the amplitude attenuation of the 20.46-min band are different at stations located in zones with different tectonic activity. These features manifest themselves in the search through different stations and through different earthquakes. © 2013 Pleiades Publishing, Ltd.

Averianov A.O.,Russian Academy of Sciences
Paleontological Journal | Year: 2013

A computer reconstruction of isolated cervical vertebrae of Azhdarcho lancicollis from the Turonian of Uzbekistan allows three-dimensional model of the cervical region of the vertebral column of this animal. The relative length of cervical vertebrae (I + II < III < IV < V > VI > VII > VIII > IX) is the same as in pterodactyloids with short cervical vertebrae. An increase in neck length is provided mostly by the middle cervical vertebrae (IV-VI). In a neutral posture, the neck of azhdarchids was not straight, as often reconstructed, but S-shaped, with the maximum angles between the V-VI (20°), VI-VII (20°), and VIII-IX (17°) vertebrae. The feeding strategy of azhdarchids was probably similar to that of pelicans. In a search for prey, azhdarchids were soaring above the water surface of large inland or nearshore marine water bodies. Their prey (predominantly fish) was captured by the widely open mouth and fell into the throat sac, the presence of which is suggested by the spiral jaw joint. Prey was swallowed during the abrupt neck flexion in the posterior segment, which brought the head in an almost horizontal position. A storklike wading ecology for azhdarchids is less probable, because these clumsy on land animals were vulnerable to terrestrial predators. © 2013 Pleiades Publishing, Ltd.

Uversky V.N.,University of South Florida | Uversky V.N.,Russian Academy of Sciences | Dunker A.K.,Indiana University
Analytical Chemistry | Year: 2012

Intrinsically disordered proteins are highly abundant in various proteomes. They are different from ordered proteins at many levels, and their structural and functional characterization requires special experimental and computational tools. © 2011 American Chemical Society.

Holevo A.S.,Russian Academy of Sciences
Theoretical and Mathematical Physics | Year: 2011

We consider the entropy gain for infinite-dimensional evolutions and show that unlike in the finitedimensional case, there are many channels with positive minimal entropy gain. We obtain a new lower bound and compute the minimal entropy gain for a broad class of bosonic Gaussian channels. We mathematically formulate the Choi-Jamiolkowski (CJ) correspondence between channels and states in the infinite-dimensional case in a form close to the form used in quantum information theory. In particular, we obtain an explicit expression for the CJ operator defining a general nondegenerate bosonic Gaussian channel and compute its norm. © 2011 MAIK/Nauka.

Puchkov V.N.,Russian Academy of Sciences
Mineralogy and Petrology | Year: 2013

Five main structural and historical stages are established in the territory of the Urals: 1) Archean-Paleoproterozoic, a time of formation of the Volgo-Uralia subcontinent and its amalgamation with the other blocks of the craton of Baltica; 2) Riphean-Vendian (Meso- and Neoproterozoic), a{cyrillic} stage that was finished with formation of Timanides; 3) Paleozoic-Early Mesozoic stage, corresponding to the development of the Uralides; 4) Mid-Jurassic-to Miocene platform stage; 5) Pliocene-Quaternary neo-orogenic stage. In this paper stratigraphic data are discussed, schemes of the structural zonation are presented, and the problems of the structural geology and geodynamics of sedimentary and magmatic complexes are discussed in a chronological order. Ideologically, the paper is based on plate and plume tectonics, in their modern versions. © 2012 Springer-Verlag Wien.

Sabirov D.S.,Russian Academy of Sciences
RSC Advances | Year: 2014

The review summarizes data on dipole polarizability of fullerenes and their derivatives, covering the most widespread classes of fullerene-containing molecules (fullerenes, fullerene exohedral derivatives, fullerene dimers, endofullerenes, fullerene ions, and derivatives with ionic bonds). These are currently presented by experimental and mainly theoretical works. Particular attention is paid to the analysis of the computational data in terms of additive schemes that assist in understanding the changes in polarizability upon fullerene functionalization and provide a general formula for calculation of polarizability for certain classes of the exohedral derivatives. Additionally, application of polarizability to the physical and chemical problems of fullerene science is discussed. It includes aspects of fullerene reactivity, physicochemical processes in carbon nanostructures (quenching of electronically-excited states, nanocapillarity, etc.) as well as use of fullerene adducts as electron-acceptor materials for organic solar cells and molecular switch devices. This journal is © the Partner Organisations 2014.

Semenov V.V.,Russian Academy of Sciences
Russian Chemical Reviews | Year: 2011

The studies devoted to methods of preparation of oligomeric and polymeric organosilanes, their properties and their use are reviewed. Industrial sources, as well as processes underlying the laboratory syntheses of these compounds are analyzed. Characteristics of the silicon - silicon σ-bond and electronic interactions in oligoorganosi-lanes are discussed. Physicochemical properties of oligomeric and polymeric organosilanes and their known and prospective applications are considered. The bibliography includes 336 references. © 2011 Russian Academy of Sciences and Turpion Ltd.

Vislobokova I.A.,Russian Academy of Sciences
Paleontological Journal | Year: 2013

Giant deer or megacerines (tribe Megacerini, family Cervidae, order Artiodactyla) dwelt in Eurasia from the Late Miocene to Holocene and in Africa in the Late Pleistocene. Based on comparative morphological data and morphofunctional analysis, morphogenetic and ecogenetic trends in this group are improved. Classification, taxonomy, phylogeny, and geographical and stratigraphical ranges of megacerines are revised. © 2013 Pleiades Publishing, Ltd.

High-throughput sequencing of whole genomes and transcriptomes allows one to generate large amounts of sequence data very rapidly and at a low cost. The goal of most mRNA sequencing studies is to perform the comparison of the expression level between different samples. However, given a broad variety of modern sequencing protocols, platforms and versions thereof, it is not clear to what extent the obtained results are consistent across platforms and laboratories. The comparison of 117 human mRNA and genome high-throughput sequencing experiments performed on the Illumina and SOLiD platforms at 26 institutions all over the world demonstrated high dependency of the gene coverage profiles on the producing laboratory. Gene coverage profiles showed laboratory-specific non-uniformity that survived the 3'-bias correction and mappability normalization, suggesting that there are other yet unknown mRNA-associated biases.

Voronova N.S.,National Research Nuclear University MEPhI | Elistratov A.A.,Russian Academy of Sciences | Lozovik Yu.E.,Moscow Institute of Physics and Technology
Physical Review Letters | Year: 2015

We theoretically analyze exciton-photon oscillatory dynamics within a homogenous polariton gas in the presence of energy detuning between the cavity and quantum well modes. Whereas pure Rabi oscillations consist of the particle exchange between the photon and exciton states in the polariton system without any oscillations of the phases of the two subcondensates, we demonstrate that any nonzero detuning results in oscillations of the relative phase of the photon and exciton macroscopic wave functions. Different initial conditions reveal a variety of behaviors of the relative phase between the two condensates, and a crossover from Rabi-like to Josephson-like oscillations is predicted. © 2015 American Physical Society. © 2015 American Physical Society.

Savanov I.S.,Russian Academy of Sciences
Astrophysical Bulletin | Year: 2015

Based on the high precision photometric observations of the Kepler space telescope, we have investigated the properties of the active regions (cold spots) on the surface of 279 stars of the spectral class G, for which 1547 superflares with energies in the range of 1033–1036 erg have been revealed. The main conclusion of our study is the quantitative estimation of the increased surface spottedness of superflare stars, which indicates enhancedmagnetic activity of these objects. The increased spottedness on the surfaces of the studied stars was confirmed based on two independent estimations of stellar brightness variations. In addition, it was concluded that superflare stars do not stand out in the common dataset of differential rotation parameters. Based on the data considered, no correlation was found of the spottedness parameters or the differential rotation parameters with the characteristics of these objects—their Rossby numbers and superflare energy. Additionally, the correlation between the superflare energy and the inverse Rossby number was considered. None of these comparisons gave an indication for the presence of any obvious correlation. The results of the analysis of five stars with a few dozen flares registered indicate that for the same star whereas spottedness S variations are small, significant changes in the superflare energy can be achieved. On the example of KIC 10422252, we show that at sixfold S variations, the flare energy varies by orders of magnitude at any given S value. ©Pleiades Publishing, Ltd.

Gabdeev M.M.,Russian Academy of Sciences
Astrophysical Bulletin | Year: 2015

We present photometric observations of two polar candidates, IPHAS J052832.69+283837.6 and 1RXS J073346.0+261933. Both objects reveal brightness variations related to the orbital period with an amplitude of about 1m, and about 0ṃ5 on the long-termscale. The object IPHASJ052832.69+283837.6 also exhibits variations of color indices and light curve shape. Long-term observations allowed us to determine the orbital period of the first system and refine the orbital period of the second system, which proved to be $${P_{ord}} = 0_.^d055593(4)$$ and $${P_{ord}} = 0_.^d139095(2)$$ respectively. The photometric data analysis proves that these systems are polars. © 2015, Pleiades Publishing, Ltd.

Linkov A.M.,Russian Academy of Sciences
Journal of Mining Science | Year: 2013

The paper presents the analytical solution to a hydraulic fracture driven by a non-Newtonian fluid and propagating under plane strain conditions in cross sections parallel to the fracture front. Conclusions are drawn on the influence of fluid properties on the fracture propagation. © 2013 Pleiades Publishing, Ltd.

Ivantsov A.Y.,Russian Academy of Sciences
Stratigraphy and Geological Correlation | Year: 2013

Metazoan trace fossils from the Upper Vendian are preserved together with remains of corresponding organisms. The traces belong to "Vendobionta", representing the Precambrian phylum Proarticulata and to a presumably trochophoran animal Kimberella quadrata. These organisms fed on microbial mats, which preserved fossil traces. Impressions of the mat surface structures, traces, and bodies of animals are preserved in marine terrigenous sediments on the basal surfaces of sandstone beds. Proarticulata grazing traces are represented by groups and chains of impressions left by the ventral side of a body or its central and posterior parts. Kimberella traces are represented by long ridges united into bundles, fans, and chains of fans. All these traces were largely formed mechanically, i.e., by mat scratching with cilia (Proarticulata) or teeth (Kimberella). Proarticulata representatives destroyed only a thin upper layer of the mat, while Kimberella could possibly scratch the mat through its entire thickness or even tear off pieces from it. © 2013 Pleiades Publishing, Ltd.

Serezhnikova E.A.,Russian Academy of Sciences
Paleontological Journal | Year: 2013

A recent study has revealed the problematic nature of "cyclic" and "radial" fossils which represent a mixed group of organisms and are most abundant in the Vendian. As a result, the validity of dozens of genera and species has become ambiguous. The situation has emerged after descriptions of variation in fossil preservation and discovery of attachment discs which have the same morphology as "cyclic" and "radial" imprints. In this paper we attempt to describe basic morphotypes of the attachments using system-structural analysis and summarizing previously known taphonomic and morphological data. The morphotypes are arranged in a matrix table with basic lines such as "Cyclomedusa" (discs) and "Hiemalora" (rootlike offshoots). Members of mean matrix points are selected according to the basic features of the attachment discs, a possible hierarchy of these objects and the stratigraphic position of the specimens. The reconstructed pattern (morphogenetic?(?) trends) appears to be similar to that in the root system of plants (or homologous parts). Flavostratum incrustatum gen. et sp. nov., a new benthic organism with a substrate-encrusting filmlike attachment is described from the Zimnegory Formation (Upper Vendian of the Arkhangelsk Region). © 2013 Pleiades Publishing, Ltd.

Ivanov K.G.,Russian Academy of Sciences
Geomagnetism and Aeronomy | Year: 2013

The dynamics of the occurrence frequency and intensity of solar-terrestrial storms at the current solar cycle (cycle 24) onset (2007-2011) is considered. The storms were identified based on the moving semidiurnal average planetary index of activity, beginning from Ap* ≥ 30. It has been established that 12, 11, and 2 only moderate storms (Ap* = 30-49), which were randomly distributed during the year, were successively observed in the first three years. After a prolonged period without storms (August 2009-March 2010), a series of storms with mixed or only moderate activity, which were regularly distributed over the seasons (ecliptic longitudes) from April to August, started appearing beginning from the storm of April 1-6, 2010. This period followed the tendency toward the transformation of the slowly rotating four-sector structure (Large-Scale Open Solar Magnetic Field, LOSMF) from the two-sector structure (March 2010). The first storm in the new cycle (April 2010) was very powerful and originated owing to the successive destabilization of the complex of two magnetic filamentary ropes. It is interesting that the origination of a new LOSMF sector was associated with a 27-day interval, during which thermal neutrons appeared at Kamchatka and volcanoes erupted in Iceland, and a strong earthquake occurred in March 2011 in Japan when the Earth was located precisely in this sector. © 2013 Pleiades Publishing, Ltd.

Vislobokova I.A.,Russian Academy of Sciences
Paleontological Journal | Year: 2013

The data on phylogeny and early evolution of Cetartiodactyla are analyzed and a model for the initial stage of their history is proposed. It is shown that the roots of Cetartiodactyla go back to generalized Cretaceous terrestrial Eutheria, and a hypothetical basal group of Cetartiodactyla was probably ancestral to the orders Artiodactyla and Cetacea. The Artiodactyla-Cetacea divergence and adaptive radiation of Artiodactyla, which gave rise to the suborders Ruminantia, Tylopoda, and Suiformes, apparently occurred in the pre-Eocene time, earlier than 55 Ma. Molecular similarity between Hippopotamidae and Cetacea is evidence of common origin of Artiodactyla and Cetacea and adaptation to aquatic environment. © 2013 Pleiades Publishing, Ltd.

Kulagina E.I.,Russian Academy of Sciences
Bulletin of Geosciences | Year: 2013

The taxonomic diversity of foraminifers from the Devonian-Carboniferous boundary beds was studied in the key sections on the western slope of the South Urals in Russia and from Mugodzhary in Kazakhstan. These sections are mainly composed of marine carbonates, apparently deposited in a shallow-water environment. The boundary interval contains 111 species belonging to 30 genera within the foraminiferal zones Quasiendothyra communis, Q. kobeitusana, Tournayellina beata pseudobeata, Earlandia minima, and Chernyshinella disputabilis of the Russian General Stratigraphic Scale. Maximum diversification is recorded in the Q. kobeitusana Zone, and minimum species diversity is observed in the Earlandia minima Zone.

The aging process is often associated with more or less prominent shifts of the entrained phases of behavioral and physiological rhythms at earlier clock hours, but the oscillatory mechanisms underlying these shifts have to be determined. The analysis of self-reports on home sleep times and self-scorings of sleepiness provided by 130 participants of sleep deprivation experiments revealed the difference between intro-individual (age-related) and inter-individual (gender- and chronotype-related) variation in phase angle between sleep timing and timing of nocturnal rise of sleepiness. This angle was found to be smaller in older participants, but larger in early chronotypes and female participants. To explain this difference, a heterochrony of age-related changes in general oscillatory features of the underlying regula- tory processes was suggested. A decline in strength of a weak circadian rhythm, such as the homeostatic process underlying oscillations of slow wave activity in the sleep-wake cycle, might occur already in middle adulthood. In contrast, such a decline might happen somewhat later in the cases of homeostatic processes underlying stronger circadian rhythms, such as the daily oscillations of alertness-sleepiness, body temperature, melatonin secretion, etc. In turn, the strengths of any of such oscillatory processes might be weakened earlier compared to the weakening of the strength of the circadian pace- maker. In turn, this weakening of the pacemaker’s strength might occur earlier compared to the decline of its ability to entrain to the light-dark cycle. Such heterochronic declines in the circadian entrainment mechanisms predict gradual advance rather than delay of the entrained phases of circadian rhythms with progression of age from middle adulthood to elderly. © 2016 Bentham Science Publishers.

Mostepanenko V.M.,Russian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

We investigate the thermal Casimir force between two parallel plates made of different isotropic materials which are separated by a uniaxial anisotropic film. Numerical computations of the Casimir pressure at T=300 K are performed using the complete Lifshitz formula adapted for an anisotropic intervening layer and in the nonrelativistic limit. It is shown that the standard (nonrelativistic) theory of the van der Waals force is not applicable in this case, because the effects of retardation contribute significantly even for film thicknesses of a few nanometers. We have also obtained simple analytic expressions for the classical Casimir free energy and pressure for large film thicknesses (high temperatures). Unlike the case of isotropic intervening films, for two metallic plates the classical Casimir free energy and pressure are shown to depend on the static dielectric permittivities of an anisotropic film. One further interesting feature is that the classical limit is achieved at much shorter separations between the plates than for a vacuum gap. Possible applications of the obtained results are discussed. © 2015 American Physical Society. ©2015 American Physical Society.

Khlebtsov N.,Chernyshevsky Saratov State University | Dykman L.,Russian Academy of Sciences
Chemical Society Reviews | Year: 2011

Recent advances in wet chemical synthesis and biomolecular functionalization of gold nanoparticles have led to a dramatic expansion of their potential biomedical applications, including biosensorics, bioimaging, photothermal therapy, and targeted drug delivery. As the range of gold nanoparticle types and their applications continues to increase, human safety concerns are gaining attention, which makes it necessary to better understand the potential toxicity hazards of these novel materials. Whereas about 80 reports on the in vivo biodistribution and in vitro cell toxicity of gold nanoparticles are available in the literature, there is lack of correlation between both fields and there is no clear understanding of intrinsic nanoparticle effects. At present, the major obstacle is the significant discrepancy in experimental conditions under which biodistribution and toxicity effects have been evaluated. This critical review presents a detailed analysis of data on the in vitro and in vivo biodistribution and toxicity of most popular gold nanoparticles, including atomic clusters and colloidal particles of diameters from 1 to 200 nm, gold nanoshells, nanorods, and nanowires. Emphasis is placed on the systematization of data over particle types and parameters, particle surface functionalization, animal and cell models, organs examined, doses applied, the type of particle administration and the time of examination, assays for evaluating gold particle toxicity, and methods for determining the gold concentration in organs and distribution of particles over cells. On the basis of a critical analysis of data, we arrive at some general conclusions on key nanoparticle parameters, methods of particle surface modification, and doses administered that determine the type and kinetics of biodistribution and toxicity at cellular and organismal levels (197 references). © 2011 The Royal Society of Chemistry.

Lunin V.Y.,Russian Academy of Sciences
Acta Crystallographica Section D: Biological Crystallography | Year: 2012

A number of methods to detect twinning are based upon the assumption that the statistical properties of diffracted intensities are different for twinned and untwinned specimens. This may not be true for a large portion of the reflections in a twinned specimen if a noncrystallographic screw axis parallel to the twinning axis is present. In this case, up to half of all reflections can obey Wilson statistics, which are typical of untwinned crystals. The distribution corresponding to a whole set of observed intensities is biased towards the Wilson distribution in this case. © 2012 International Union of Crystallography Printed in Singapore - all rights reserved.

Filimonova S.A.,Russian Academy of Sciences
Arthropod Structure and Development | Year: 2013

All life stages of B. chanayi (Acariformes: Cheyletidae) are characterized by occasional bloodsucking and a long period of digestion. No newly engorged mites were found during the period of their host birds' migration. The fine structure of the digestive tract of a blood-feeding acariform mite is described for the first time. The anterior midgut (AMG) is a place of blood digestion, while the posterior midgut (PMG) is involved in nitrogen metabolism forming guanine crystals as the main end-product. The AMG epithelium consists of digestive cells that probably arise from mitotically active basal cells with high synthesizing activity.As observed in ticks, blood digestion is accompanied by the formation of huge endosomes that serve as places of storage and sorting of ingested material. Digestive cells show different types of endocytotic activity as well as various late endosomes, which implies different subcellular pathways for different blood components. In both midgut regions, elimination of the excretory material occurs by apocrine secretion or by discharging of apical cell fragments (loaded with lysosomes) into the gut lumen. The formation of guanine granules occurs inside the lysosomes of PMG epithelial cells thus having much in common with intracellular digestion. Peculiarities of intracellular blood digestion were analyzed according to the modern hypothesis of endocytosis and compared to what is known in ticks. © 2013 Elsevier Ltd.

Dolgopolova E.N.,Russian Academy of Sciences
Water Resources | Year: 2013

Approaches to the mathematical description of bore propagation upstream a river in its mouth area are briefly reviewed. Data on some river mouths, where bores were observed, are given, and the conditions of their formation are considered. The existence of a bore is determined by tide magnitude, river runoff, and the depth profile in the estuary. The same factors govern seawater penetration distance into river mouths, the degree of mixing of seawater and river water, and the regularities of sediment motion at river mouths. The types of water circulation at the mouths of the greatest rivers, where bore takes place, are considered, and its effect on seawater intrusion range into river mouths is analyzed. The results of comparison of the effect of channel training on bore existence conditions and the propagation range of saline water into the estuaries of the Seine (France) and Qiantang (China) are given. © 2013 Pleiades Publishing, Ltd.

Shaposhnikov M.V.,Russian Academy of Sciences
Advances in gerontology = Uspekhi gerontologii / Rossiǐskai{combining double inverted breve}a akademii{combining double inverted breve}a nauk, Gerontologicheskoe obshchestvo | Year: 2011

Age-dependent accumulation of genome rearrangements leads to cellular senescence, overall aging and lifespan decreasing of the organism. In this respect, it is important to study the effect of overexpression of DNA repair genes on the lifespan and aging parameters (rates of age-related decline of fertility and locomotor activity). The present work investigates how the overexpression of the PARP-1 gene, which is involved in various mechanisms of DNA repair (base excision repair and DNA double-strand breaks repair), combined with a pharmacological inhibition of the NF-kB transcription factor that controls the genes of inflammatory response, affects the lifespan of Drosophila melanogaster. It is demonstrated that in males, constitutive activation of PARP-1 overexpression in the nervous system throughout the lifetime results in reduced median (by 14%) and maximum (by 8%) lifespan, whereas in females the median (by 14%) and maximum (by 20%) lifespan increases. Activation of PARP-1 overexpression in the imago (conditionally) results in extension of the median (by 3-16%) and the maximum (by 10-15%) lifespan in females and males, respectively. The lifespan increase in females with PARP-1 conditional overexpression was accompanied by decrease of fertility. Selective pharmacological inhibition of transcription factor NF-kB with pyrrolidine dithiocarbamate increases the median (by 13-20%) and the maximum (by 11-14%) lifespan in females and males, respectively. No synergic effect between conditionally activated PARP-1 expression and NF-kB inhibition is observed. The geroprotective effect of PARP-1 overexpression depends on the sex and the life history stage of overexpression induction.

Although representatives with spiral-shaped cells are described for many functional groups of bacteria, this cell morphotype has never been observed among methanotrophs. Here, we show that spiral-shaped methanotrophic bacteria do exist in nature but elude isolation by conventional approaches due to the preference for growth under micro-oxic conditions. The helical cell shape may enable rapid motility of these bacteria in water-saturated, heterogeneous environments with high microbial biofilm content, therefore offering an advantage of fast cell positioning under desired high methane/low oxygen conditions. The pmoA genes encoding a subunit of particulate methane monooxygenase from these methanotrophs form a new genus-level lineage within the family Methylococcaceae, type Ib methanotrophs. Application of a pmoA-based microarray detected these bacteria in a variety of high-latitude freshwater environments including wetlands and lake sediments. As revealed by the environmental pmoA distribution analysis, type Ib methanotrophs tend to live very near the methane source, where oxygen is scarce. The former perception of type Ib methanotrophs as being typical for thermal habitats appears to be incorrect because only a minor proportion of pmoA sequences from these bacteria originated from environments with elevated temperatures.The ISME Journal advance online publication, 8 April 2016; doi:10.1038/ismej.2016.48. © 2016 International Society for Microbial Ecology

Uversky V.N.,University of South Florida | Uversky V.N.,Russian Academy of Sciences
FEBS Letters | Year: 2013

Many functional proteins do not have well-folded structures in their substantial parts, representing hybrids that possess both ordered and disordered regions. Disorder is unevenly distributed within these hybrid proteins and is typically more common at protein termini. Disordered tails are engaged in a wide range of functions, some of which are unique for termini and cannot be found in other disordered parts of a protein. This review covers some of the key functions of disordered protein termini and emphasizes that these tails are not simple flexible protrusions but are evolved to serve. © 2013 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Sedukhin A.G.,Russian Academy of Sciences
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2010

A model of discontinuity-free edge diffraction is proposed that is valid in the framework of the scalar Debye approximation and describes the formation process and approximate structure of the stationary diffracted field of a monochromatic converging spherical wave of limited angular opening throughout the whole space about the focus. The field is represented semianalytically in terms of the sum of a direct quasi-spherical wave and two edge quasi-conical waves of the zeroth and first order. The angular spectrum amplitudes of all these waves have smooth continuous variations of the real and imaginary parts in polar angle and radius, the separable nonanalytic functions defining the polar-angle variations of the amplitudes being found by optimization techniques. © 2010 Optical Society of America.

Lebedev V.S.,Russian Academy of Sciences
Problems of Information Transmission | Year: 2010

We propose a new group testing model, which is related to separating codes and cover-free codes. © 2010 Pleiades Publishing, Ltd.

Barr I.D.,Queens University of Belfast | Solomina O.,Russian Academy of Sciences
Global and Planetary Change | Year: 2014

This review summarises landform records and published age-estimates (largely based upon tephrochronology) to provide an overview of glacier fluctuations upon the Kamchatka Peninsula during the Holocene and, to a lesser degree, earlier phases of glaciation. The evidence suggests that following deglaciation from the Last Glacial Maximum (LGM), the peninsula experienced numerous phases of small-scale glacial advance. During the Late Glacial, moraine sequences appear to reflect the former presence of extensive glaciers in some parts of the peninsula, though little chronological control is available for deposits of this period. During the Holocene, the earliest and most extensive phase of advance likely occurred sometime prior to c. 6.8. ka, when glaciers extended up to 8. km beyond their current margins. However, these deposits lack maximum age constrains, and pre-Holocene ages cannot be discounted. Between c. 6.8. ka and the onset of 'Neoglaciation' c. 4.5. ka, there is little evidence of glacial advance upon the peninsula, and this period likely coincides with the Holocene climatic optimum (or 'hypsithermal'). Since c. 4.5. ka, numerous moraines have been deposited, likely reflecting a series of progressively less extensive phases of ice advance during the Late Holocene. The final stage of notable ice advance occurred during the Little Ice Age (LIA), between c. 1350 and 1850 C.E., when reduced summer insolation in the Northern Hemisphere likely coincided with solar activity minima and several strong tropical volcanic eruptions to induce widespread cooling. Following the LIA, glaciers upon the peninsula have generally shown a pattern of retreat, with accelerated mass loss in recent decades. However, a number of prominent climatically and non-climatically controlled glacial advances have also occurred during this period. In general, there is evidence to suggest that millennial scale patterns in the extent and timing of glaciation upon the peninsula (encompassing much of the last glacial period) are governed by the extent of ice sheets in North America. Millennial-to-centennial scale fluctuations of Kamchatkan glaciers (encompassing much of the Holocene) are governed by the location and relative intensity of the Aleutian Low and Siberian High pressure systems. Decadal scale variations in glacier extent and mass balance (particularly since the LIA) are governed by inter-decadal climatic variability over the North Pacific (as reflected by the Pacific Decadal Oscillation), alongside a broader trend of hemispheric warming. © 2013.

Volkov A.F.,Ruhr University Bochum | Volkov A.F.,Russian Academy of Sciences | Efetov K.B.,Ruhr University Bochum
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We study the dc Josephson effect in a diffusive multilayered SF ′ FF′ S structure, where S is a superconductor and F and F′ are different ferromagnets. We assume that the exchange energies in the F′ and F layers are different (h and H, respectively) and the middle F layer consists of two layers with parallel or antiparallel magnetization vectors M. The M vectors in the left and right F ′ layers are generally not collinear to those in the F layer. In the limit of a weak proximity effect we use a linearized Usadel equation. Solving this equation, we calculate the Josephson critical current for arbitrary temperatures, arbitrary thicknesses of the F′ and F layers (Lh and LH) in the case of parallel and antiparallel M orientations in the F layer. The part of the critical current IcSR formed by the short-range singlet and S=0 triplet condensate components decays on a short length ξH =√ D/H, whereas the part IcLR due to the long-range triplet |S| =1 component decreases with increasing LH on the length ξN =√ D/πT. Our results are in a qualitative agreement with the experiment. © 2010 The American Physical Society.

Postnov K.A.,Moscow State University | Yungelson L.R.,Russian Academy of Sciences
Living Reviews in Relativity | Year: 2014

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Mergings of compact-star binaries are expected to be the most important sources for forthcoming gravitational-wave (GW) astronomy. In the first part of the review, we discuss observational manifestations of close binaries with NS and/or BH components and their merger rate, crucial points in the formation and evolution of compact stars in binary systems, including the treatment of the natal kicks, which NSs and BHs acquire during the core collapse of massive stars and the common envelope phase of binary evolution, which are most relevant to the merging rates of NS-NS, NS-BH and BH-BH binaries. The second part of the review is devoted mainly to the formation and evolution of binary WDs and their observational manifestations, including their role as progenitors of cosmologically-important thermonuclear SN Ia. We also consider AM CVn-stars, which are thought to be the best verifcation binary GW sources for future low-frequency GW space interferometers.

Kaganer V.M.,Paul Drude Institute for Solid State Electronics | Sabelfeld K.K.,Russian Academy of Sciences
Acta Crystallographica Section A: Foundations of Crystallography | Year: 2010

X-ray diffraction peak profiles are calculated by the Monte Carlo method for arbitrarily correlated dislocations without making any approximations or simplifications. The arrangement of dislocations in pairs with opposite Burgers vectors provides screening of the long-range strains. Moreover, any screening can be modeled by appropriate distribution of the dislocation pairs. Analytical description of the peak profiles is compared with the Monte Carlo results. Symmetric peaks due to screw dislocations and asymmetric peaks due to edge dislocations are simulated and analyzed. © 2010 International Union of Crystallography Printed in Singapore - all rights reserved.

A multi-level stochastic model taking into account the magnetic anisotropy, precession and diffusion of the uniform magnetization of single-domain particles is developed in order to describe the Mössbauer absorption spectra of an ensemble of magnetic nanoparticles in the presence of quadrupolar hyperfine interaction with an arbitrary orientation of its principal axes. This model allows one to take into account physical mechanisms for forming the hyperfine structure in a real situation and can be easily realized even on a personal computer. In particular, now one can numerically describe qualitative features of temperature evolution of the Mössbauer spectral shape from a symmetric magnetic sextet to a quadrupolar doublet of lines, which has been observed in a large number of experimental spectra of 57Fe nuclei in magnetic nanoparticles for almost half a century. © 2011 IOP Publishing Ltd.

Levshina S.,Russian Academy of Sciences
Water, Air, and Soil Pollution | Year: 2012

To have a better understanding of the industrial organic contamination of the city of Khabarovsk, southern Russian Far East, snow cover of the winter seasons of 2009-2010 and 2010-2011 was sampled at the end of March of 2010 and 2011 at six sites (and at eight sites in 2011) of the urban area and on the adjacent snow cover of the Amur River. The samples were analyzed by high-performance liquid chromatography and gas chromatography/mass spectrometry techniques for petroleum products and phenols. Themain groups of the detected pollutantswere n-alkanes, isoalkanes, paraffins, phenols, and phthalates. The total concentration of the petroleum products was 0.08-2.84 mg/L, volatile phenols 0.17-3.61 μg/L. 4-Nitrophenol has been found among the phenols (0.22-1.65 μg/L). The minimum toxicant concentrations were found in background sites (first hundred meters) off the urban highways, and the maximum, in dumps of snow from the urban highways and the vicinities of Heat Power-3. Of aromatic compounds, insignificant amounts of isopropylbenzene (0.5 μg/L) and xylenes (0.2-0.3 μg/L) and a high content of ethylbenzene (1.3 μg/L) originated from local emission were found. For the unpolluted sites, identification of n-alkanes revealed high-molecular paraffins C 26-C 33 (50 % of the total n-alkane content); fractions in the range of C 19-C 21 and C 24 were found for the snow dumps, 55.0 % and 90.0 % of the total alkane content in 2010 and 2011, correspondingly. These compounds originated most probably from the wasted diesel fuel and mineral greases (derivatives). The study indicated the dangerous level of the Khabarovsk urban atmosphere deterioration with a range of organic pollutants of transport and industrial origin. The snow (and rain) urban runoff may affect the local soil and water ecosystems subsequently. © Springer Science+Business Media B.V. 2012.

In addition to the major functions performed by in the cell, mitochondria play a major role in cell-light interaction. Accordingly it is generally accepted that mitochondria are crucial in cell photobiomodulation; however a variety of biomolecules themselves proved to be targets of light irradiation. We describe whether and how mitochondria can interact with monochromatic and narrow band radiation in the red and near IR optical regions with dissection of both structural and functional effects likely leading to photobiostimulation. Moreover we also report that a variety of biomolecules localized in mitochondria and/or in other cell compartments including cytochrome c oxidase, some proteins, nucleic acids and adenine nucleotides are light sensitive with major modifications in their biochemistry. All together the reported investigations show that the elucidation of the mechanism of the light interaction with biological targets still remains to be completed, this needing further research, however the light sensitivity of a variety of molecules strongly suggests that photobiomodulation could be used in both in photomedicine and in biotechnology. © 2014 Elsevier B.V. All rights reserved.

Aref'eva I.Y.,Russian Academy of Sciences
Physics-Uspekhi | Year: 2014

We review recent applications of the dual holographic approach to describing the quark±gluon plasma observed in high-energy collisions of relativistic heavy nuclei. Holography and AdS/CFT duality provide a means to study the properties of strong-coupling quantum field theories using higher-dimen- sional gravity theories. The appearance of quark±gluon plasma in heavy ion collisions can be described in dual terms as the formation of a black hole. To illustrate the major achievements of holographic theory, we discuss the calculation of the follow- ing quantities: the shear viscosity and other transport coeffi- cients (all calculated by second order hydrodynamic models), the energy dependence of multiplicities, and the anisotropic thermalization and isotropization times. We also compare the- oretical predictions with available experimental data, including the recent LHC results. © 2014 Uspekhi Fizicheskikh Nauk, Russian Academy of Sciences.

Sturman B.,Russian Academy of Sciences | Breunig I.,Albert Ludwigs University of Freiburg
Journal of the Optical Society of America B: Optical Physics | Year: 2011

Extending Yariv's generic approach to the description of optical microresonators, we describe the secondharmonic generation and the optical parametric oscillation in whispering-gallery resonators (WGRs). The output characteristics of these nonlinear processes are expressed in terms of conventional cavity/coupling parameters and nonlinear material coefficients. The found relations are relevant to the description and optimization of experiments with nonlinearly active WGRs at ultralow input light powers. © 2011 Optical Society of America.

Khalaman V.V.,Russian Academy of Sciences
Hydrobiologia | Year: 2013

Patterns of long-term changes in fouling communities developing on artificial substrates in the White Sea are reviewed. The most significant shifts occurring in these communities are caused by biological successions that can last for several decades. Terminal stages of succession are the communities of a mussel Mytilus edulis or a solitary ascidian Styela rustica which can periodically replace one another within a narrow range of depths: from 1-1. 5 to 5 m. Sporadic local invasion of a sponge Halichondria panicea can transiently modify the composition and performance of fouling communities. Sudden invasion of species that are not a typical component of fouling communities (infaunal polychaetes and molluscs, crabs) is not rare phenomenon but these organisms do not play a significant role there. Representatives of the associated polychaete fauna in fouling communities show long-term cyclic fluctuations in their abundances. Duration of these cycles is 7-8, 11-14, or 20 years. © 2012 Springer Science+Business Media Dordrecht.

Dedysh S.N.,Russian Academy of Sciences
Frontiers in Microbiology | Year: 2011

Northern wetlands play a key role in the global carbon budget, particularly in the budgets of the greenhouse gas methane. These ecosystems also determine the hydrology of northern rivers and represent one of the largest reservoirs of fresh water in the Northern Hemisphere. Sphagnum-dominated peat bogs and fens are the most extensive types of northern wetlands. In comparison to many other terrestrial ecosystems, the bacterial diversity in Sphagnum-dominated wetlands remains largely unexplored. As demonstrated by cultivation-independent studies, a large proportion of the indigenous microbial communities in these acidic, cold, nutrient-poor, and water-saturated environments is composed of as-yet-uncultivated bacteria with unknown physiologies. Most of them are slow-growing, oligotrophic microorganisms that are difficult to isolate and to manipulate in the laboratory. Yet, significant breakthroughs in cultivation of these elusive organisms have been made during the last decade. This article describes the major prerequisites for successful cultivation of peat-inhabiting microbes, gives an overview of the currently captured bacterial diversity from northern wetlands and discusses the unique characteristics of the newly discovered organisms. © 2011 Dedysh.

Morozov V.A.,Russian Academy of Sciences
Physical Chemistry Chemical Physics | Year: 2013

A statistical theory of temperature-induced spin-crossover-like transitions has been developed for spin chains with a few exchange clusters in a unit cell. Using static magnetic susceptibility measurements, a general expression for the effective magnetic moment μeff of exchange clusters is obtained for an arbitrary structure of cluster terms. For heterospin Cu(hfac) 2LR complexes ("breathing crystals") with a "head-to-head" chain motif, a two-point approximation for a partition function of the Jahn-Teller Cu+2 paramagnetic center (spin 1/2) is suggested. Theoretical results are compared with available experimental data on thermal spin-crossover-like transitions in the "breathing crystal" compounds. It is shown that the model developed is able to successfully describe both of the cases of smooth and abrupt (cooperative) spin transitions for chains of three-spin exchange clusters. Spin-crossover-like transitions of a new type with step-wise changes in a positive exchange integral are predicted. © 2013 the Owner Societies.

The subfamily Protoscelinae from the Middle to Late Jurassic of Karatau is transferred from the family Chrysomelidae to the family Anthribidae. The genus Protoscelis, comprising five species, is reviewed. Males and females of the genus are described and keys to the identification of male and female specimens are provided. The new species P. medvedevi sp. nov. is described. The generic names Cerambyomima Medvedev, 1968, Pseudomegamerus Medvedev, 1968 and Protosceloides Medvedev, 1968 are synonymized under Protoscelis Medvedev, 1968, and the species Pseudomegamerus grandis Medvedev, 1968 is synonymized under Cerambyomima longicornis Medvedev, 1968. The new combinations Protoscelis longicornis (Medvedev, 1968) comb. nov. and P. nitidicornis (Medvedev, 1968) comb. nov. are established. © 2013 Pleiades Publishing, Ltd.

Koulakov I.,Russian Academy of Sciences
Journal of Volcanology and Geothermal Research | Year: 2013

This paper presents an overview of several examples of multiscale studies of different volcanic systems including intracontinental, collisional and subduction-related volcanic areas. Regional tomographic models of the upper mantle are presented for three regions with the Cenozoic intracontinental volcanism in Eurasia, namely Europe, Southern Siberia and Eastern Arctic. In all cases, recent volcanic fields correlate with low-velocity anomalies in the mantle. The modeling results show that these volcanic manifestations are related to large hot areas in the mantle and not to thin column-shaped contrasted plumes, as presumed by many. Collisional-type volcanism is discussed with an example of the Caucasus and the surrounding areas. The regional tomographic model for this region reveals a lack of mantle lithosphere beneath the collision zone. Volcanism in this area is most likely due to the direct heating of the thick crust by the hot asthenosphere. A dominantly felsic composition of the crust facilitates upward transport of the fluids and melts that leads to volcanic eruption. Subduction-related volcanic systems are discussed for three different scale levels. An example of a regional model of the mantle beneath the Sunda arc reveals the general configuration of the slab. Middle-scale tomographic models in areas of the Toba Caldera, Central Java and Central Andes display feeding paths of the arc volcanoes from the slab. The feeding paths are apparent in all of the considered cases but have different shapes depending on the unique features of the subduction regimes. An example of a detailed local-scale study of magmatic sources in the crust is discussed for the Kluchevskoy volcano group. It is found that the main volcano, Kluchevskoy, is fed through a complex three-layered system of magma sources. Another volcano of the same group, Bezymianny, seems to be connected with the mantle through a direct short-lived channel, which appears only during the eruption periods. A time-dependent tomography study performed for this group over a period of ten years clearly reveals the correlation between the changes in the seismic structures and the stages of the volcanic process, namely, preparation, activation and relaxation. © 2013 Elsevier B.V.

Alferov Zh.I.,Russian Academy of Sciences
Russian Chemical Reviews | Year: 2013

This review is based on the plenary lecture presented by the author at the German - Russian Scientific Symposium 'Chemistry Shaping the Future' held in November, 2012, at the Central House of Scientists in Moscow. The review considers the background and milestones of the revolutionary development of semiconductor electronics in the 20th century, including the discovery of the transistor and semiconductor laser. The role of heterostructures and quantum size effects is highlighted. The significance of semiconductor solar energy converters for solving energy problems is discussed. The bibliography includes 32 references. © 2013 Russian Academy of Sciences and Turpion Ltd.

Svinin A.K.,Russian Academy of Sciences
Journal of Physics A: Mathematical and Theoretical | Year: 2011

We show that by the Miura-type transformation the Itoh-Narita- Bogoyavlenskii lattice, for any n > 1, is related to some differential-difference (modified) equation. We present corresponding integrable hierarchies in their explicit form. We study the elementary Darboux transformation for modified equations. © 2011 IOP Publishing Ltd.

Maslov V.P.,Russian Academy of Sciences
Russian Journal of Mathematical Physics | Year: 2011

In the paper, the principal aspects of the mathematical theory of equilibrium thermodynamics are distinguished. It is proved that the points of degeneration of a Bose gas of fractal dimension in the momentum space coincide with critical points or real gases, whereas the jumps of critical indices and the Maxwell rule are related to the tunnel generalization of thermodynamics. Semiclassical methods are considered for the tunnel generalization of thermodynamics and also for the second and ultrasecond quantization (operators of creation and annihilation of pairs). To every pure gas there corresponds a new critical point of the limit negative pressure below which the liquid passes to a dispersed state (a foam). Relations for critical points of a homogeneous mixture of pure gases are given in dependence on the concentration of gases. © 2011 Pleiades Publishing, Ltd.

Maslov V.P.,Russian Academy of Sciences
Russian Journal of Mathematical Physics | Year: 2011

For a gas mixture, the new concept of number-theoretic internal energy is introduced. This energy does not depend on the masses of the miscible gases. © 2011 Pleiades Publishing, Ltd.

Nazarov S.A.,Russian Academy of Sciences
Russian Journal of Mathematical Physics | Year: 2011

It is proved that, under a certain geometrical assumption in the linear water-wave problem, a body approaching the water surface of a symmetric three-dimensional channel gets any number of trapped modes with frequencies in the interval (0, δ) of the continuous spectrum; here δ can be any given positive number. © 2011 Pleiades Publishing, Ltd.

Svinin A.K.,Russian Academy of Sciences
Journal of Physics A: Mathematical and Theoretical | Year: 2011

We introduce two classes of homogeneous polynomials and show their role in construction of integrable hierarchies for some integrable lattices. © 2011 IOP Publishing Ltd.

Mellerowicz E.J.,Umea Plant Science Center | Gorshkova T.A.,Russian Academy of Sciences
Journal of Experimental Botany | Year: 2012

Gelatinous fibres are specialized fibres, distinguished by the presence of an inner, gelatinous cell-wall layer. In recent years, they have attracted increasing interest since their walls have a desirable chemical composition (low lignin, low pentosan, and high cellulose contents) for applications such as saccharification and biofuel production, and they have interesting mechanical properties, being capable of generating high tensional stress. However, the unique character of gelatinous layer has not yet been widely recognized. The first part of this review presents a model of gelatinous-fibre organization and stresses the unique character of the gelatinous layer as a separate type of cell-wall layer, different from either primary or secondary wall layers. The second part discusses major current models of tensional stress generation by these fibres and presents a novel unifying model based on recent advances in knowledge of gelatinous wall structure. Understanding this mechanism could potentially lead to novel biomimetic developments in material sciences. © 2011 The Author.

Bashan Y.,National Polytechnic Institute of Mexico | Kamnev A.A.,Russian Academy of Sciences | de-Bashan L.E.,National Polytechnic Institute of Mexico
Biology and Fertility of Soils | Year: 2013

Literature analysis and chemical considerations of biological phosphate solubilization have shown that the commonly used selection factor for this trait, tricalcium phosphate (TCP), is relatively weak and unreliable as a universal selection factor for isolating and testing phosphate-solubilizing bacteria (PSB) for enhancing plant growth. Most publications describing isolation of PSB employed TCP. The use of TCP usually yields many (up to several thousands per study) isolates "supposedly" PSB. When these isolates are further tested for direct contribution of phosphorus to the plants, only a very few are true PSB. Other compounds are also tested, but on a very small scale. These phosphates (P), mainly Fe-P, Al-P, and several Ca-P, are even less soluble than TCP in water. Because soils greatly vary by pH and several chemical considerations, it appears that there is no metal-P compound that can serve as the universal selection factor for PSB. A practical approach is to use a combination of two or three metal-P compounds together or in tandem, according to the end use of these bacteria-Ca-P compounds (including rock phosphates) for alkaline soils, Fe-P and Al-P compounds for acidic soils, and phytates for soils rich in organic P. Isolates with abundant production of acids will be isolated. This approach will reduce the number of potential PSB from numerous isolates to just a few. Once a potential isolate is identified, it must be further tested for direct contribution to P plant nutrition and not necessarily to general growth promotion, as commonly done because promotion of growth, even by PSB, can be the outcome of other mechanisms. Isolates that do not comply with this general sequence of testing should not be declared as PSB. © 2012 Springer-Verlag.

Klimchitskaya G.L.,Russian Academy of Sciences
International Journal of Modern Physics A | Year: 2016

We present theoretical description of the Casimir interaction in graphene systems which is based on the Lifshitz theory of dispersion forces and the formalism of the polarization tensor in (2+1)-dimensional space-time. The representation for the polarization tensor of graphene allowing the analytic continuation to the whole plane of complex frequencies is given. This representation is used to obtain simple asymptotic expressions for the reflection coefficients at all Matsubara frequencies and to investigate the origin of large thermal effect in the Casimir force for graphene. The developed theory is shown to be in a good agreement with the experimental data on measuring the gradient of the Casimir force between a Au-coated sphere and a graphene-coated substrate. The possibility to observe the thermal effect for graphene due to a minor modification of the already existing experimental setup is demonstrated. © 2016 World Scientific Publishing Company.

Chalov S.V.,Russian Academy of Sciences
Monthly Notices of the Royal Astronomical Society | Year: 2010

The non-linear evolution of unstable acoustic waves in the precursors of cosmic ray mediated shocks with large Mach numbers results in the formation of a host of weak shock waves. These weak shocks heat the thermal plasma, and therefore change the parameters of the strong large-scale shock. © 2009 RAS.

Bagderina Y.Yu.,Russian Academy of Sciences
Journal of Physics A: Mathematical and Theoretical | Year: 2010

For a system of second-order ordinary differential equations conditions of linearizability to the form x″ = 0 are well known. However, an arbitrary linear system need not be equivalent via an invertible point transformation to this simple form. We provide the criteria for a system of two second-order equations to be mapped to the linear system of the general form. Necessary and sufficient conditions for linearization by means of a point transformation are given in terms of coefficients of the system. These results are illustrated with a number of examples. © 2010 IOP Publishing Ltd.

Nazarov S.A.,Russian Academy of Sciences
Theoretical and Mathematical Physics | Year: 2011

We establish that by choosing a smooth local perturbation of the boundary of a planar quantum waveguide, we can create an eigenvalue near any given threshold of the continuous spectrum and the corresponding trapped wave exponentially decaying at infinity. Based on an analysis of an auxiliary object, a unitary augmented scattering matrix, we asymptotically interpret Wood's anomalies, the phenomenon of fast variations in the diffraction pattern due to variations in the near-threshold wave frequency. © 2011 MAIK/Nauka.

Burinskii A.,Russian Academy of Sciences
Journal of Physics A: Mathematical and Theoretical | Year: 2010

The charged, spinning and gravitating soliton is realized as a regular solution of the Kerr-Newman (KN) field coupled with a chiral Higgs model. A regular core of the solution is formed by a domain wall bubble interpolating between the external KN solution and a flat superconducting interior. An internal electromagnetic (em) field is expelled to the boundary of the bubble by the Higgs field. The solution reveals two new peculiarities: (i) the Higgs field is oscillating, similar to the known oscillon models; (ii) the em field forms on the edge of the bubble a Wilson loop, resulting in quantization of the total angular momentum. © 2010 IOP Publishing Ltd.

Birger B.I.,Russian Academy of Sciences
Geophysical Journal International | Year: 2013

Large-scale mantle convection forms the upper boundary layer (lithosphere) where the vertical temperature drop is about 1300 K. Theoretical rheology and laboratory experiments with rock samples show that transient creep occurs while creep strains are sufficiently small. The transient creep is described by the temperature-dependent Andrade rheological model. Since plate tectonics allows only small deformations in lithospheric plates, creep of the lithosphere plates is transient whereas steady-state creep, described by non-Newtonian power-law rheological model, takes place in the underlying mantle. The solution of stability problem shows that the lithosphere is stable but small-scale convective oscillations are attenuated very weakly in regions of thickened lithosphere beneath continental cratons (subcratonic roots) where the thickness of the lithosphere is about 200 km. These oscillations create small-scale convective cells (the horizontal dimensions of the cells are of the order of the subcratonic lithosphere thickness). Direction of motion within the cells periodically changes (the period of convective oscillations is of the order of 3 × 108 yr). In this study, the oscillations of cratonic lithosphere caused by initial relief perturbation are considered. This relief perturbation is assumed to be created by overthrusting in orogenic belts surrounding cratons. The perturbation of the Earth's surface relief leads to a fast isothermal process of isostatic recovery. In the presence of vertical temperature gradient, vertical displacements, associated with the recovery process in the lithosphere interior, instantly produce the initial temperature perturbations exciting thermoconvective oscillations in the cratonic lithosphere. These small-amplitude convective oscillations cause oscillatory crustal movements which form sedimentary basins on cratons. © The Authors 2013. Published by Oxford University Press on behalf of The Royal Astronomical Society.

Dronov A.,Russian Academy of Sciences
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2013

The Upper Ordovician of the Tungus Basin on the Siberian Platform is represented by cool-water carbonates. Onset of cool-water conditions starts at the Darriwilian, and it is associated with widespread phosphatization, especially in the Volginian, Kirensko-Kudrinian and Chertovskian regional stages (mid-Darriwilian-lower Sandbian). The shift from tropical-type to temperate-type carbonates was preceded by destruction of the warm-water "carbonate factory" and a large input of siliciclastic material (Baykit Sandstone) during the Vikhorevian and Mukteian regional stages (lower to mid-Darriwilian). Wide distribution of temperate-type carbonates across the Siberian Platform, located in the low latitudes in the Ordovician time, can be explained by upwelling of cold oceanic waters and their penetration into epicontinental seas. The same situation was recorded for the Upper Ordovician of the North American Platform. Newly discovered K-bentonite beds in the uppermost Sandbian-Katian of the Tungus Basin are also associated with cool-water carbonates. The K-bentonite beds point to extensive volcanism on or near the western (in present-day orientation) margin of the Siberian Craton in the Late Ordovician time. Timing of the volcanism is surprisingly close to the period of volcanic activity of the Taconic Arc near the margin of Laurentia. Both upwelling and volcanism seem to be activated by the same plate-tectonic reorganization, and both these processes seem to play an important role in a global, later Ordovician cooling terminated by the Hirnantian glaciation. © 2013 Elsevier B.V.

Tarahovsky Y.S.,Russian Academy of Sciences
Biochemistry (Moscow) | Year: 2010

The perspectives of using liposomes for delivery of drugs to desired parts of the human body have been intensively investigated for more than 30 years. During this time many inventions have been suggested and different kinds of liposomal devices developed, and a number of them have reached the stages of preclinical or clinical trials. The latest techniques can be used to develop biocompatible nano-sized liposomal containers having some abilities of artificial intellect, such as the presence of sensory and responsive units. However, only a few have been clinically approved. Further improvements in this area depend on our knowledge of the interactions of drugs with the lipid bilayer of liposomes. Further studies on liposomal transport through the human body, their targeting of cells requiring therapeutic treatment, and finally, the development of techniques for controlled drug delivery to desired acceptors on cell surfaces or in cytoplasm are still required. © 2010 Pleiades Publishing, Ltd.

Purpose: The aim of this study was to investigate the effect of a 120-day 5° head-down tilt (HDT) bed-rest on the mechanical properties of the human triceps surae muscle in healthy young women subjects. Methods: Measurements included examination of the properties of maximal voluntary contractions (MVC), twitch contractions (P t) and tetanic contractions (P o). The difference between P o and MVC expressed as a percentage of P o and referred to as force deficiency (P d), was calculated. Electromyographic (EMG) activity in the soleus muscle, electromechanical delay (EMD) and total reaction time (TRT) were also calculated. EMD was the time interval between the change in EMG and the onset of muscle tension. Premotor time (PMT) was taken to be the time interval from the delivery of the signal to change in EMG. Results: After HDT P t, MVC and P o had decreased by 11.5, 36.1, 24.4 %, respectively, P d had increased by 38.8 %. Time-to-peak tension had increased by 13.6 %, but half-relaxation time had decreased by 19.2 %. The rate of rise in isometric voluntary tension development had reduced, but no changes were observed in the electrically evoked contraction. EMD had increased by 27.4 %; PMT and TRT decreased by 21.4, and 13.7 %, respectively. Conclusion: The experimental findings indicated that neural as well as muscle adaptation occurred in response to HDT. EMD is a simple and quick method for evaluation of muscle stiffness changes and can serve as an indicator of the functional condition of the neuromuscular system. © 2014 The Author(s).

Karimova S.,Russian Academy of Sciences
International Journal of Remote Sensing | Year: 2013

Examination of non-stationary eddies in the Black Sea is presented based on satellite visible and infrared imagery. The images were obtained by the Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectrometer (MODIS) between September 2004 and December 2010. As a result of the analysis performed, it was discovered that there are four main non-stationary eddy types which can be frequently observed in such imagery: near-shore anticyclonic eddies, mushroom-like currents, eddies of the Anatolian coast, and eddy chains. For each type of eddy, spatio-temporal parameters were retrieved such as areas of the most frequent generation and typical length scale, as well as their seasonality. Every non-stationary eddy type was shown to have its own area of location. Analysis of eddy spatial scale revealed that anticyclonic eddies of all types were greater in size than cyclonic ones (on average 52 km for anticyclones and 36 km for cyclones). © 2013 Taylor & Francis.

Vikhlyantsev I.M.,Russian Academy of Sciences
Biochemistry. Biokhimii{combining double inverted breve}a | Year: 2012

This review summarizes results of our studies on titin isoform composition in vertebrate striated muscles under normal conditions, during hibernation, real and simulated microgravity, and under pathological conditions (stiff-person syndrome, post-apoplectic spasticity, dilated cardiomyopathy, cardiac hypertrophy). Experimental evidence for the existence in mammalian striated muscles of higher molecular weight isoforms of titin (NT-isoforms) in addition to the known N2A-, N2BA-, and N2B-titin isoforms was obtained. Comparative studies of changes in titin isoform composition and structure-functional properties of human and animal striated muscles during adaptive and pathological processes led to a conclusion about the key role of NT-isoforms of titin in maintenance of sarcomere structure and contractile function of these muscles.

Filimonova T.V.,Russian Academy of Sciences
Stratigraphy and Geological Correlation | Year: 2013

Six assemblages of smaller foraminifers are first distinguished and described from sections of the Kalmard tectonic block, Central Iran. The assemblages that have been studied are correlated with concurrent assemblages from the East European platform, Cis-Urals, Darvaz, Northern Pamir, and some other regions of the Tethyan Realm. The results of correlation and available data on fusulinids and conodonts occurring in association with smaller foraminifers are used for dating the assemblages whose distribution ranges span the stratigraphic interval from the early Sakmarian (lower assemblage) up to the Kubergandian (uppermost assemblage). New species Frondina iranica sp. nov. discovered in the study region is described. © 2013 Pleiades Publishing, Ltd.

Recently, representatives of the genus Cuboctostylus Bragina (order Entactinaria) were included in the Upper Cretaceous radiolarian regional stratigraphic scale of Sakhalin. The Late Cretaceous species Hexacromyum pergamenti Bragina (order Spumellaria) has morphological similarity to representatives of the genus Cuboctostylus. Peculiar features of H. pergamenti internal structure are considered. Collections of Upper Cretaceous radiolarians from southern Cyprus, Serbia, northern Turkey, Crimean Mountains, East European Platform, northwestern Kamchatka, eastern slope of the Sredinnyi Range in Kamchatka, and Shikotan Island (Lesser Kurile Range) were used for the analysis of the taxonomic composition of Late Cretaceous representatives of the genera Cuboctostylus Bragina and Hexacromyum Haeckel as well as their stratigraphic and paleobiogeographic distribution. It is established that Cuboctostylus is distributed from tropical to south boreal realms. This genus is shown to exist through almost the entire Late Cretaceous: from the middle Cenomanian to initial Maastrichtian. Hexacromyum Haeckel populated both the south boreal realm and marginal areas of the Tethys Ocean in the Late Cretaceous. The new data presented may be used for distant interregional correlations. Cuboctostylus stellatus sp. nov. and several other Cuboctostylus taxa identified in open nomenclature are described; some morphological features of Hexacromyum pergamenti are specified. © 2013 Pleiades Publishing, Ltd.

Khonina S.N.,Russian Academy of Sciences
Optics Communications | Year: 2011

A new kind of truncated Airy beams is investigated and discussed. These beams are a superposition of shifted and truncated Airy functions and its specular counterparts, where zeroes or extremal points of the Airy function are chosen as a truncation point. The specular Airy beams are smooth at the truncation point and produce a diffraction pattern similar to Hermite-Gaussian modes. Under propagation in Fresnel zone, specular Airy beams demonstrate a symmetrical acceleration in opposite sides and the beam divergence is proportional to the traveled distance squared. The astigmatic mode converter transforms a two-dimensional specular Airy beam into a quasi-annular field with a nonzero orbital angular momentum. Vortical Airy beams based on truncated Airy functions are also discussed. These beams are similar to Laguerre-Gaussian modes, while their annular structure is changed during propagation. © 2011 Elsevier B.V.

Spiridonov V.P.,Russian Academy of Sciences | Vartanov G.S.,Max Planck Institute For Gravitationsphysik
Communications in Mathematical Physics | Year: 2011

We give a full list of known N = 1 supersymmetric quantum field theories related by the Seiberg electric-magnetic duality conjectures for SU(N), SP(2N) and G2 gauge groups. Many of the presented dualities are new, not considered earlier in the literature. For all these theories we construct superconformal indices and express them in terms of elliptic hypergeometric integrals. This gives a systematic extension of the related Römelsberger and Dolan-Osborn results. Equality of indices in dual theories leads to various identities for elliptic hypergeometric integrals. About half of them were proven earlier, and another half represents new challenging conjectures. In particular, we conjecture a dozen new elliptic beta integrals on root systems extending the univariate elliptic beta integral discovered by the first author. © 2011 Springer-Verlag.

The kinematics of the Early Caledonian accretion process in the southwest (in modern coordinate) of the Siberian paleocontinent, and the structure of its active continental margin are debatable subjects. This paper contains a generalization of paleomagnetic data on island-arc terranes of the territories of the Altai-Sayan and Baikal-Vitim folded areas for the Late Vendian/Cambrian-Early Ordovician time interval, obtained mostly with the author's participation during the last two decades. The large accumulated database finally allows one to find unambiguously interpretable patterns in the distribution of paleomagnetic poles for the analyzed terrane system and to justify numerically the kinematics of the Early Caledonian accretion. In particular, the analysis of paleomagnetic data proves our idea stating that the transformation of the active continental margin in the Cambrian consisted in its breakup and segmentation as well as in the detachment of fragments of the initially whole island arc along a system of sinistral strike-slips during the clockwise rotation of the craton and conform drift of the continental and oceanic lithospheric plates. It also validates the mostly oblique conditions of the subduction and subsequent accretion, which means a subduction-transform mode on the ocean-continent margin. We propose a complemented version of the paleotectonic reconstruction for the Cambrian evolution of the Siberian continent western margin, based on the kinematic scheme constructed from paleomagnetic data. © 2013 .

Faddeev L.D.,Russian Academy of Sciences
Theoretical and Mathematical Physics | Year: 2011

We describe an alternative formalism for Einstein's theory of gravity. The role of dynamical variables is played by a collection of ten vector fields fμ A A = 1,...,10. The metric is a composite variable, gμν = fμ Afν A. The proposed scheme may lead to further progress in a theory of gravity where Einstein's theory is to play the role of an effective theory, with Newton's constant appearing by introducing an anomalous Green's function. © 2011 MAIK/Nauka.

Shevchenko I.I.,Russian Academy of Sciences
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

We consider statistics of the disruption and Lyapunov times in an hierarchical restricted three-body problem. We show that at the edge of disruption the orbital periods and the size of the orbit of the escaping body exhibit Lévy flights. Due to them, the time decay of the survival probability is heavy-tailed with the power-law index equal to -2/3, while the relation between the Lyapunov and disruption times is quasilinear. Applicability of these results in an "hierarchical resonant scattering" setting for a three-body interaction is discussed. © 2010 The American Physical Society.

Chibisov A.N.,Russian Academy of Sciences
Computational Materials Science | Year: 2014

We have used density functional theory calculations to investigate the interaction of titanium (Ti) nanoparticles with oxygen. We found the energy-favorable site for oxygen atoms on a Ti13 cluster surface and investigated the atomic structure of the oxidized cluster. Our results showed that during oxidation, the oxygen atoms advantageously occupied positions on the titanium clusters that are similar to "bulk" interstitial sites. © 2013 Elsevier B.V. All rights reserved.

Koval A.,University of Konstanz | Katanaev V.L.,University of Konstanz | Katanaev V.L.,Russian Academy of Sciences
Biochemical Journal | Year: 2011

Receptors of the Fz (Frizzled) family initiate Wnt ligand-dependent signalling controlling multiple steps in organism development and carcinogenesis. Fz proteins possess seven transmembrane domains, and their signalling depends on heterotrimeric G-proteins in various organisms; however, Fz proteins constitute a distinct group within the GPCR (G-protein-coupled receptor) superfamily, and Fz signalling can be G-protein-independent in some experimental setups, leading to concerns about the GPCR nature of these proteins. In the present study, we demonstrate that mammalian Fz proteins act as GPCRs on heterotrimeric Go/i proteins. Addition of the Wnt3a ligand to rat brain membranes or cultured cells elicits Fz-dependent guanine-nucleotide exchange on Go/i proteins. These responses were sensitive to a Wnt antagonist and to pertussis toxin, which decouples the Go/i proteins from their receptors through covalent modification. The results of the present study provide the long-awaited biochemical proof of the GPCR nature of Fz receptors. © The Authors Journal compilation © 2011 Biochemical Society.

Mikhalevich V.I.,Russian Academy of Sciences
Micropaleontology | Year: 2013

A new suprageneric classification of the Foraminifera is here presented based on fundamentally new concepts of their evolution and classification. The predominant significance is given to the shell morphology as the most conservative feature, while the wall composition and shell wall ultrastructure are considered as having important but nevertheless subordinate meaning. Foraminifera are regarded as a phylum that includes five classes: Astrorhizata Saidova 1981, Spirillinata Mikhalevich 1992, Miliolata Saidova 1981, Nodosariata Mikhalevich 1992 and Rotaliata Mikhalevich 1980. Each of the five classes unite forms that can be characterized by a complex of common features of their shell morphology reflecting the building plan of the organism (number of chambers, their form, the predominant mode of coiling, position and character of the aperture and its inner structures, the presence or absence of additional apertures, the presence or absence of integrative systems and their peculiarities, and some other features - all of them having evolutionary significance). Each of these classes represents independent and well-outlined phyletic lines. Some characters of the cell structure and nuclear apparatus are also used as taxonomic features of some higher-ranking taxa where the accumulated data permit. Isomorphic agglutinated forms differing from their calacareous analogues in their shell wall composition are separated as subclasses within the appropriate classes: the subclasses Ammodiscana Mikhalevich 1980, Miliamminana Mikhalevich 1980, Hormosinana Mikhalevich 1992, Textulariana Mikhalevich 1980 within the Spirillinata, Miliolata, Nodosariata and Rotaliata correspondingly (the latter also includes two calcareous subclasses - the Rotaliana Mikhalevich 1980 and Globigerinana Mikhalevich 1980).Within the class Astrorhizata, subclasses with organic (Lagynana Mikhalevich 1980) and agglutinated (Astrorhizana Saidova 1981) shell walls are included. In total, the phylum Foraminifera embraces 73 orders, 27 suborders, 98 superfamilies, 499 families and 368 subfamilies among which 2 orders (Cymbaloporida, Cassigerinellida), one suborder Duostominina, two families (Cymbaloporettidae, Haynesinidae), and two subfamilies (Cushmanellinae and Tristixinae) are described as new. The composition of the classes and subclasses is also partially revised. The largest changes were made within the classes Spirillinata, Miliolata and Nodosariata: thus the Fusulinids were included into the Miliolata, the Chapmaninids - into the Spirillinata, the Stilostomellids, Pleurostomellids and Paleozoic Nodosariids - into the Nodosariata. The former suborder Textulariina (= Textulariacea Ehrenberg 1838 sensu lata Loeblich and Tappan 1987) was shown to be heterogenous and its representatives are split out into several subclasses of the different classes according to their shell morphology. The composition of the subclasses is here given up to the family level; most of the subclasses need further revision at the family and generic level. Under the new approach the morphologically similar agglutinated and calcareous shells within each class could be regarded as closely related rather than convergent forms. The rise and development of the classes took place independently and in parallel in each of the phylogenetic lines examined.

Volovich I.V.,Russian Academy of Sciences
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2016

We discuss non-classicality of photon antibunching and sub-Poisson photon statistics. The difference K between the variance and the mean of the particle number operator as a measure of non-classicality of a state is discussed. The non-classicality of quantum states, discussed here, is different from another non-classicality, related with Bell's inequalities and entanglement though both can be traced to the violation of an inequality implied by an assumption of classicality that utilized the Cauchy-Schwarz inequality in the derivation. © 2015 Elsevier B.V.

Chuburin Y.P.,Russian Academy of Sciences
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2016

We study, within the tight-binding approximation, the scattering problem for the Hamiltonian of the carbon nanotube with the non-local impurity potential. The Green function of the non-perturbed Hamiltonian was found explicitly. In the case where the potential and the electron velocity are small, we obtained a simple expression for the transmission probability. The scattering occurs mainly in the two subbands. The transmission probability increases by increasing the diameter of a carbon nanotube, or when the Fermi energy tends to zero. We found the condition when the transmission probability is close to unity. © 2015 Elsevier B.V.

Leinson L.B.,Russian Academy of Sciences
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2015

In a simple model it is demonstrated that the neutron star surface temperature evolution is sensitive to the phase state of the triplet superfluid condensate. A multicomponent triplet pairing of superfluid neutrons in the core of a neutron star with participation of several magnetic quantum numbers leads to neutrino energy losses exceeding the losses from the unicomponent pairing. A phase transition of the neutron condensate into the multicomponent state triggers more rapid cooling of superfluid core in neutron stars. This makes it possible to simulate an anomalously rapid cooling of neutron stars within the minimal cooling paradigm without employing any exotic scenarios suggested earlier for rapid cooling of isolated neutron star in Cassiopeia A. © 2014 The Author.

Morozov S.V.,Russian Academy of Sciences
Physics-Uspekhi | Year: 2012

A review of the experiments on high-mobility graphene structures, which were performed by S V Morozov with A Geim's group at the University of Manchester, is studied. Two ways of obtaining more perfect graphene structures began to show, the use of suspended bridges, and encapsulation of graphene between boron nitride (BN) crystallites. The charge carriers in graphene are similar to relativistic particles with a zero rest mass. As the carrier concentration lowers and the electroneutrality point is approached, the screening length increases and the electron-electron interaction plays an increasingly important part. The inclusion of electron-electron interaction results in a lowering of the density of states at low energies and in an increase in Fermi velocity. When graphene resides at the point of electroneutrality, this gives rise to a finite concentration of electrons and holes with opposite spin directions.

Burinskii A.,Russian Academy of Sciences
Journal of Physics: Conference Series | Year: 2012

The observable gravitational and electromagnetic parameters of an electron: mass m, spin J = ℏ/2, charge e and magnetic moment ea = eℏ/(2m) indicate unambiguously that the electron should had the Kerr-Newman background geometry - exact solution of the Einstein-Maxwell gravity for a charged and rotating black hole. Contrary to the widespread opinion that gravity plays essential role only on the Planck scales, the Kerr-Newman gravity displays a new dimensional parameter a = ℏ/(2m), which for parameters of an electron corresponds to the Compton wavelength and turns out to be very far from the Planck scale. Extremely large spin of the electron with respect to its mass produces the Kerr geometry without horizon, which displays very essential topological changes at the Compton distance resulting in a two-fold structure of the electron background. The corresponding gravitational and electromagnetic fields of the electron are concentrated near the Kerr ring, forming a sort of a closed string, structure of which is close to the described by Sen heterotic string. The indicated by Gravity stringlike structure of the electron contradicts to the statements of Quantum theory that electron is pointlike and structureless. However, it confirms the peculiar role of the Compton zone of the "dressed" electron and matches with the known limit of the localization of the Dirac electron. We discuss the relation of the Kerr string with the low energy string theory and with the Dirac theory of electron and suggest that the predicted by the Kerr-Newman gravity closed string in the core of the electron, should be experimentally observable by the novel regime of the high energy scattering - the Deeply Virtual (or "nonforward") Compton Scattering".

Burinskii A.,Russian Academy of Sciences
Journal of Physics: Conference Series | Year: 2012

The observable parameters of the electron indicate unambiguously that its gravitational background should be the Kerr-Newman solution without horizons. This background is not flat and has a non-trivial topology created by the Kerr singular ring. This ring was identified with a closed gravitational string. We discuss the relation of this string to the closed heterotic string of the low energy string theory and show that travelling waves along the KN string give rise to the Dirac theory of electron. Gravitational strings form a bridge between gravity and quantum theory, indicating a new way to consistent Quantum Gravity. We explain the pointlike experimental exhibition of the electron and argue that the predicted closed string may be observed by the novel experimental method of the "nonforward" Compton scattering.

Lozhkin A.V.,Russian Academy of Sciences | Anderson P.M.,University of Washington
Climate of the Past | Year: 2013

Preliminary analyses of Lake El'gygytgyn sediment indicate a wide range of ecosystem responses to warmer than present climates. While palynological work describing all interglacial vegetation is ongoing, sufficient data exist to compare recent warm events (the postglacial thermal maximum, PGTM, and marine isotope stage, MIS5) with "super" interglaciations (MIS11, MIS31). Palynological assemblages associated with these climatic optima suggest two types of vegetation responses: one dominated by deciduous taxa (PGTM, MIS5) and the second by evergreen conifers (MIS11, MIS31). MIS11 forests show a similarity to modern Picea-Larix-Betula-Alnus forests of Siberia. While dark coniferous forest also characterizes MIS31, the pollen taxa show an affinity to the boreal forest of the lower Amur valley (southern Russian Far East). Despite vegetation differences during these thermal maxima, all glacial-interglacial transitions are alike, being dominated by deciduous woody taxa. Initially Betula shrub tundra established and was replaced by tundra with tree-sized shrubs (PGTM), Betula woodland (MIS5), or Betula-Larix (MIS11, MIS31) forest. The consistent occurrence of deciduous forest and/or high shrub tundra before the incidence of maximum warmth underscores the importance of this biome for modeling efforts. The El'gygytgyn data also suggest a possible elimination or massive reduction of Arctic plant communities under extreme warm-earth scenarios. © Author(s) 2013.

Kuznetsov V.D.,Russian Academy of Sciences
Physics-Uspekhi | Year: 2012

The processes occurring in the Sun-Earth system are understood by realizing how the Sun is structured and how it operates, and what the space environment of Earth is and how it changes. Information about the processes occurring in the solar core is obtained from ground-based neutrino measurements. The differentiated character of solar rotation manifests itself in the equatorial plasma, together with its frozen magnetic field, moving faster than at high latitudes. Among the most powerful manifestations of sporadic solar activity are flares and mass ejections which possess the highest geoefficiency from the standpoint of their terrestrial effect. One hypothesis for the cause of variations in the solar cycle period and the amplitude is associated with separation of the meridian circulation vortex in the convective zone into two vortices, which changes the circulation time of the major vortex. It is also hypothesized that solar wind on the Sun emanates from the boundaries of the chromospheric network.

A scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) devoted to the 'Physical properties of graphene' was held in the conference hall of the Lebedev Physical Institute on March 28, 2012. The agenda of the session included reports by alkovsky L A and Varlamov A A. The participants were informed that the methods for studying the metallic state appeared to be magnetotransport and magnetooptical investigations. One of the clearest manifestations of the specific character of the graphene spectrum was provided by the behavior of its dynamic conductivity. The spatial dispersion of conductivity and the frequency of collisions of charge carriers were insignificant in the optical range at higher frequencies.

Koulakov I.,Russian Academy of Sciences
Journal of Geophysical Research: Solid Earth | Year: 2011

A model of seismic P and S anomalies in the upper mantle beneath Asia (in limits of 35°E-140°E, 12°N-57°N) was constructed based on the tomographic inversion of traveltime data from the revised ISC catalog for the years 1964-2004. The inversions were performed independently in 32 overlapping circular windows that cover the entire study area. The free inversion parameters in each window were defined individually depending on the available data based on synthetic modeling. Such adaptive tuning of parameters enables more optimal usage of the input data in areas with inhomogeneous ray coverage compared to global inversions. This approach resolves high-frequency patterns but is less sensitive to large anomalies with sizes comparable to the window diameter. Thus, this approach is somewhat similar to high-frequency filtration of the velocity distribution. The resolution capacity of the model was tested using checkerboard tests with various pattern sizes. To assess the role of random noise, independent test inversions of two data subsets (with odd and even numbers of events) were performed. Clear reconstructions of known structures, such as subducting plates beneath the Japan and Ryukyu arcs whose locations and shapes have been constrained by other studies, further indicate the reliability of the model. The 3-D models of P and S anomalies presented in horizontal and vertical sections show complex interactions of the lithospheric segments beneath the Alpine-Himalayan orogenic belts. Particular attention is focused on the collisional areas of Iran, Pamir-Hindukush, Tien-Shan, and Burma. The digital version of the 3-D P and S models is available at http://www.ivan-art.com/ science/REGIONAL. Copyright 2011 by the American Geophysical Union.

D'Yakonova V.E.,Russian Academy of Sciences
Neuroscience and Behavioral Physiology | Year: 2014

Behavioral choice is known to depend on context, i.e., a variety of internal and external factors: previous experience, behavioral state, presence of food, etc. How is the totality of factors determining behavioral choice translated at the cellular level? This review presents neuroethological data providing evidence that context is expressed at the neurological level in terms of the composition of neuroactive molecules in the extracellular milieu, controlling the functioning of the corresponding neuron ensembles. © 2014 Springer Science+Business Media New York.

Stolyarov V.V.,Russian Academy of Sciences
Journal of Alloys and Compounds | Year: 2013

The features of the influence of electroplastic deformation on the structure and the mechanical properties of shape-memory TiNi alloys in coarse-grained and nanostructured states are investigated. Introduction of pulse current during cold rolling stimulates deformability increase, and causes occurrence of stress jumps during tension connected with reverse martensite transformation or electroplastic effect. It is shown that electroplastic effect is a structurally sensitive property dependent on the grain size. © 2012 Elsevier B.V.

Shlyannikov V.N.,Russian Academy of Sciences
Engineering Fracture Mechanics | Year: 2013

Fatigue crack paths for inclined cracks are studied through experiments and computations under different mixed-mode loading. The elaborated theoretical model is applied for modeling crack growth trajectories in common experimental fracture mechanics specimen geometries. For the particular specimen geometries considered, the T-stress distributions are calculated along the curved crack path. It is shown that there is a greater variation of T-stress along the crack trajectories under mixed mode fracture for specimen with different geometries. The experimental data for mixed mode fracture trajectories during crack growth are compared with theoretical predictions. Discrepancies in fatigue crack path have been observed in various specimen configurations. The results presented in this study for fracture specimens seem to indicate the relevance of crack tip constraint parameter, the T-stress, to fatigue crack path behavior that conventional LEFM fails to explain. © 2013 Elsevier Ltd.

Audiogenic kindling (AK) represents a model of naturally occurring epileptogenesis in which intensification of repeatedly induced audiogenic seizures results from propagation of epileptic activity from the brainstem to forebrain. Previously it has been shown that unilateral cortical spreading depression (SD) is a reliable earliest manifestation of mild AK produced by repetition of minimal audiogenic seizures (running) in Wistar rats. The unilateral triggering SD suggests the existence of asymmetry in the forebrain recruitment during the kindling and the present study examined whether epileptogenesis produced by this mild AK paradigm is a lateralized process. Twenty five running episodes were induced by brief sound stimulation in Wistar rats susceptible to audiogenic seizures. Behavioral and EEG correlates of AK development were assessed. Running behavior elicited by brief sound stimulation had an asymmetrical pattern with profound preference for one direction. Most rats expressing leftward running displayed full kindling development whereas the majority of rats with rightward running were resistant to AK. The EEG marker of AK, a cortical epileptiform discharge, was recorded only in rats with leftward running and the first discharge appeared in the left cortex. Cortical SD was recorded after repeated running seizures in all rats with reproducible audiogenic response irrespective of the running lateralization and propensity to kindling. Until the late kindling stages, SD was triggered unilaterally in the cortex ipsilateral to the running direction. These findings indicate intrinsically determined lateralization of epileptogenic process in the mild AK model and enhanced vulnerability of the left hemisphere to epileptogenesis. © 2010 Elsevier B.V. All rights reserved.

Glagolevskij Y.V.,Russian Academy of Sciences
Astrophysics | Year: 2015

The rate of magnetic field relaxation in magnetic CP-stars after they emerge from the zero age Main-sequence line is discussed. Data are introduced which indicate a slow increase in the large-scale dipole component of the magnetic field and a simultaneous slow disappearance of its small-scale component. The magnetic field of CP-stars reaches a maximum after 0.2-0.5 times their lifetime. Data are introduced to support the assumption that the large-scale magnetic field of CP-stars vanishes at the end of their time in the Main sequence because convection develops in the corresponding phases of their evolution. There are indications that the observed dependence of the magnitude of the field on the rotation period of CPstars largely reflects a similar dependence in the protostellar clouds. © 2015, Springer Science+Business Media New York.

Savanov I.S.,Russian Academy of Sciences
Astrophysical Bulletin | Year: 2015

Based on the photometric observations obtained with the Kepler telescope, we investigated the properties of the active regions (cold spots) on the surfaces of 737 stars with planetary systems (exoplanets). We used three methods for determining the spottedness (S) of stellar surfaces. A comparison of the results of the S determination through these three methods was performed for two stars (KOI 877 and KOI 896), taken as examples. We studied the dependences of the spottedness of the stars with exoplanets on the effective temperature and on the period of their axial rotation. There is no evidence that the magnetic activity of a star with exoplanets has any special features that distinguish it fromthe activity of the stars froma wider sample. The spottedness of stars with planetary systems in most cases does not exceed 5% of the area of their surface. The three objects for which it exceeds 5% were examined in detail. It was found that for the stars with effective temperatures less than 5750 K, there is a monotonic decrease of the spottedness with the increase of the rotation period of the star. We established the absence of stars with small values of S (less than 0.002) among the stars with effective temperatures less than 5750 K and rotation periods less than 10 days. Stars with effective temperatures of more than 5750 K have small spottedness in the case of rapid rotation, but S increases for objects with rotation periods of 20–25 days. © 2015, Pleiades Publishing, Ltd.

The wavelengths of the 3d 94d [J = 0]-3d 94p [J = 1] transitions of x-ray lasers in Ni-like sequence ions with nucleus charges Z 79 are refined. The results of calculations are within the experimental error. It was found that the wavelengths of [J = 0]-4p1/2 [J = 1] and 4d3/2[J = 0]-4p3/2[J = 1] transitions in Sm34+ and Gd36+, respectively, are in the range of 6.70-6.75 nm. Exactly for this narrow range, multilayer mirrors with high reflectance are developed. The gain of the x-ray laser with λ = 6.748 nm in Gd36+ is calculated under the assumption that plasma is formed during the interaction of a nanostructured (cluster-like) gadolinium target with high-intensity pump laser radiation. The optimum plasma density, temperature, length, and pump parameters are determined to achieve the highest Gd36+ ion fraction and emission quantum yield of ∼1013 photons. © 2015 Astro Ltd.

If the motion of a body along a rough surface is modeled such that the point of contact has a zero velocity, in many cases qualitatively incorrect results can be obtained. For the model to be physically valid, it is necessary to take into account the finite contact area and the presence of rotational friction, along with the sliding friction. © 2015 Uspekhi Fizicheskikh Nauk, Russian Academy of Sciences.

Alekseev G.,Russian Academy of Sciences
Classical and Quantum Gravity | Year: 2015

Some classes of the so-called 'travelling wave' solutions of Einstein and Einstein-Maxwell equations in general relativity and of dynamical equations for massless bosonic fields in string gravity in four and higher dimensions are presented. Similarly to the well known plane-fronted waves with parallel rays (pp-waves), these travelling wave solutions may depend on arbitrary functions of a null coordinate which determine the arbitrary profiles and polarizations of the waves. However, in contrast with pp-waves, these waves do not admit the null Killing vector fields and can exist in some curved (expanding and spatially homogeneous) background space-times, where these waves propagate in certain directions without any scattering. Mathematically, some of these classes of solutions arise as the fixed points of Kramer-Neugebauer transformations for hyperbolic integrable reductions of the above mentioned field equations or, in other cases, after imposing the ansatz that these waves do not change the part of the spatial metric transverse to the direction of wave propagation. It is worth noting that the strikingly simple forms of all the solutions presented prospectively make possible the consideration of the nonlinear interaction of these waves with the background curvature and singularities, as well as the collision of such wave pulses with solitons or with each other in the backgrounds where such travelling waves may exist. © 2015 IOP Publishing Ltd.

Romanyuk I.I.,Russian Academy of Sciences
Astrophysical Bulletin | Year: 2015

We make a critical analysis of the results of studies of magnetic fields in chemically peculiar and related stars, published mostly in 2014. Methodological matters are discussed, and research results are analyzed. Most of the measurements of magnetic fields were obtained with well-known instruments. In 2014 a large observational project MiMeS was accomplished, the observations of more than 500 objects were performed, magnetic fields were found in 35 of them. Twenty new magnetic stars have been detected from the observations with the SAORAS 6-m telescope. Regular measurements of magnetic fields with an accuracy of units of gauss are conducted on a number of telescopes using the HARPS, ESPaDOnS, and NARVAL spectropolarimeters. The fields of complex topology have been studied, magnetic maps have been built, a connection with the distribution of anomalies of chemical composition has been found. The debate about the existence of a magnetic field of about 1 G in Vega and some other objects is ongoing. Apparently, the absence of a large-scale magnetic field greater than tens of gauss in the mercury-manganese and Am stars is confirmed. First CP stars were detected outside the Galaxy, in the Large Magellanic Cloud. Observations of magnetic fields in solar-type stars are continued, a strong correlation between the field strength and the degree of chromospheric activity was discovered. © 2015, Pleiades Publishing, Ltd.

Kurganova I.,University of Gottingen | Lopes de Gerenyu V.,Russian Academy of Sciences | Six J.,ETH Zurich | Kuzyakov Y.,University of Gottingen
Global Change Biology | Year: 2014

The collapse of collective farming in Russia after 1990 and the subsequent economic crisis led to the abandonment of more than 45 million ha of arable lands (23% of the agricultural area). This was the most widespread and abrupt land use change in the 20th century in the northern hemisphere. The withdrawal of land area from cultivation led to several benefits including carbon (C) sequestration. Here, we provide a geographically complete and spatially detailed analysis of C sequestered in these abandoned lands. The average C accumulation rate in the upper 20 cm of mineral soil was 0.96 ± 0.08 Mg C ha-1 yr-1 for the first 20 years after abandonment and 0.19 ± 0.10 Mg C ha-1 yr-1 during the next 30 years of postagrogenic evolution and natural vegetation establishment. The amount of C sequestered over the period 1990-2009 accounts to 42.6 ± 3.8 Tg C per year. This C sequestration rate is equivalent to ca. 10% of the annual C sink in all Russian forests. Furthermore, it compensates all fire and postfire CO2 emissions in Russia and covers about 4% of the global CO2 release due to deforestation and other land use changes. Our assessment shows a significant mitigation of increasing atmospheric CO2 by prolonged C accumulation in Russian soils caused by collective farming collapse. © 2013 John Wiley & Sons Ltd.

Gilfanov M.R.,Russian Academy of Sciences
Physics-Uspekhi | Year: 2013

X-ray emission of the majority of galaxies in the observable part of the Universe is due to X-ray binaries, accreting neutron stars and black holes in close binary systems. Their population is determined by the entire history of star formation of the host galaxy, and in the first approximation by its mass and the star formation rate. The total number of compact sources and their total luminosity in star-forming (young) and elliptical (old) galaxies are respectively proportional to the star formation rate and the stellar mass. The luminosity functions of compact stars in young and old galaxies are radically different, which is related to different regimes of mass accretion in high-mass and low-mass X-ray binaries. The specific number of high-mass X-ray binaries per unit star formation rate suggests that a significant fraction of compact objects becomes accreting X-ray sources during the first 100 Myrs after their birth.

Klyuchevskii A.V.,Russian Academy of Sciences
Journal of Geodynamics | Year: 2010

This is an attempt to analyze the current lithospheric stress pattern in the Baikal rift in terms of nonlinear dynamics as an open self-organizing system in order to gain more insights into the general laws of regional seismicity. According to the suggested approach, the stress pattern inferred from seismic moments of 70,000 M LH ≥ 2.0 events that occurred in the region between 1968 and 1994 is presented as a phase portrait in the phase spaces of the seismic moments. The obtained phase portrait of the system evolution fits well a scenario with triple equilibrium bifurcation where stress bifurcations account for the frequency of M > 5.5 earthquakes. Extrapolation of the results into the nearest future indicates probability of such a bifurcation (a catastrophe of stress), i.e., there is growing risk that M ≈ 7 events may happen in the region within a few years. © 2009 Elsevier Ltd. All rights reserved.

Khramov A.V.,Russian Academy of Sciences
Paleontological Journal | Year: 2010

A new lacewing species, Leptolingia shartegica sp. nov., (Grammolingiidae), from the Upper Jurassic of the Mongolian Shar-Teg locality is described. © 2010 Pleiades Publishing, Ltd.

Dorogokupets P.I.,Russian Academy of Sciences
Physics and Chemistry of Minerals | Year: 2010

A simplest equation within the framework of the Mie-Grüneisen-Einstein approach is considered. Pressure estimation values are presented that are derived by conventional arithmetic and algebraic calculations as a function of temperature and volume. The equation under consideration complies with the Mie-Grüneisen-Debye model at high temperature. Different versions of an equation of state (EoS) of MgO proposed by Speziale et al. (J Geophys Res 106B:515-528, 2001) as a pressure standard at high temperatures are subject to analyses. In the literature, at least four versions of Speziale et al. EoS of MgO are discussed; the discrepancy between them reaching a few GPa at T > 2,000 K and P > 100 GPa. Our analyses of these equations suggest that the volume dependence of the Debye temperature is accepted arbitrarily and does not agree with the definition of the Grüneisen parameter, γ = -(∂lnΘ/∂lnV)T. Pressure as a function of temperature and volume in the Mie-Grüneisen-Einstein approach or the Gao pressure calculator can be used to estimate true pressure at compression x = V/V0 < 1 with the Speziale et al. EoS of MgO. © 2010 Springer-Verlag.

Akhmetiev M.A.,Russian Academy of Sciences
Bulletin of Geosciences | Year: 2010

Paleocene and Eocene floras of Russia and adjacent regions are reviewed with an interpretation of climatic conditions under which they developed. Floristic and climatic changes in western and central regions of Russia in the Paleocene and in the first part of the Eocene were caused by the dynamics and rearrangement of the systems of marine seaways: a longitudinal seaway, which connected the Arctic basin with the marginal seas of Northern Peri-Tethys (Turanian, South Russian and others), and a latitudinal seaway, which connected the marginal seas of Northern Peri-Tethys with the Atlantic Ocean. As these systems were progressively reduced, the climate in the middle latitudes changed from paratropical (like in West and Central Europe) to a subtropical monsoon climate with wet summers (Late Ypresian to Lutetian), and later to a climate with wet winters (Late Lutetian to the first part of the Priabonian). Floristic changes reflect these climatic trends. In the Paleogene, cold currents constantly influenced the climate of regions of the northwestern Pacific and facilitated development of a warm-temperate mesophilic flora. A warmer episode took place in the Early Eocene. At this time thermophilic plants (Sabal, Myrtaceae and Lauraceae) reached Koryakia, North Western Kamchatka, probably as a result of northward migration. Some subtropical plants existed near the Recent Polar circle. The subtropical Raichikha-type Flora lost temperate elements and, by ecological and climatic types, it is more similar to the Recent flora of South-West and South China.

Lisitzin A.P.,Russian Academy of Sciences
Russian Geology and Geophysics | Year: 2010

Research on sedimentogenesis and geochemistry of the Arctic Ocean over the last 10-20 years has allowed direct (in situ) studies to be made for all types of sedimentary matter that mix together and form the bottom deposit. Contrary to common knowledge, river sediment turned out to be insignificant; instead, more important is the dispersed sedimentary matter (suspension) from the atmosphere, cryosphere (snow, ice), marine water, riverine water, biosphere (plankton and benthos), and anthroposphere (all types of pollutants), supplemented by the endogenic mater supplied from spreading zone of the Gakkel Ridge. The mixture is dominated by sedimentary material discharged from sea ice; hence, this type of sedimentogenesis is referred to as the ice-rafted marine sedimentogenesis. Application of new methods and tools (including satellites, remote hydrooptical, hydrophysical, and hydroacoustic survey, etc.) and in situ analyses produced measurements of content, composition, and characteristics of all types of dispersed sedimentary matter, its fluxes (mg/m2/year), vectors of movement, and rates for different segments of the Arctic Ocean; observations were carried out continuously on different time scale, from hours-days to seasons and dozens of years. It is a new approach to the study of sedimentary matter that opens up new possibility for a 4D quantitative sedimentology. © 2009.

Petoukhov V.,Potsdam Institute for Climate Impact Research | Semenov V.A.,Leibniz Institute of Marine Science | Semenov V.A.,Russian Academy of Sciences
Journal of Geophysical Research: Atmospheres | Year: 2010

The recent overall Northern Hemisphere warming was accompanied by several severe northern continental winters, as for example, extremely cold winter 2005-2006 in Europe and northern Asia. Here we show that anomalous decrease of wintertime sea ice concentration in the Barents-Kara (B-K) seas could bring about extreme cold events like winter 2005-2006. Our simulations with the ECHAM5 general circulation model demonstrate that lower-troposphere heating over the B-K seas in the Eastern Arctic caused by the sea ice reduction may result in strong anticyclonic anomaly over the Polar Ocean and anomalous easterly advection over northern continents. This causes a continental-scale winter cooling reaching -1.5°C, with more than 3 times increased probability of cold winter extremes over large areas including Europe. Our results imply that several recent severe winters do not conflict the global warming picture but rather supplement it, being in qualitative agreement with the simulated large-scale atmospheric circulation realignment. Furthermore, our results suggest that high-latitude atmospheric circulation response to the B-K sea ice decrease is highly nonlinear and characterized by transition from anomalous cyclonic circulation to anticyclonic one and then back again to cyclonic type of circulation as the B-K sea ice concentration gradually reduces from 100% to ice free conditions. We present a conceptual model that may explain the nonlinear local atmospheric response in the B-K seas region by counter play between convection over the surface heat source and baroclinic effect due to modified temperature gradients in the vicinity of the heating area. Copyright © 2010 by the American Geophysical Union.

Artyushkov E.V.,Russian Academy of Sciences
Russian Geology and Geophysics | Year: 2010

The large North Chukchi Basin in the northeastern Eurasian shelf is filled with up to 22 km of sediments, which is far thicker than filling a basin upon oceanic crust would require. The basin sedimentation began 380 Myr ago, and about 16 km of sediments have been deposited for the past 125 Myr, long after the oceanic crust would have completed its subsidence. This fact is in favor of the continental instead of oceanic crust origin. Rapid basin subsidence appears to be driven by a mechanism other than crustal stretching as the latter has no evidence over the greatest part of the basin area. The suggested basin formation model implies a transformation of gabbro into denser eclogite in the lower crust and related contraction of mafic rocks. To sustain consolidated crust beneath 22 km thick sediments, the layer of dense eclogites under the granitic layer must be at least ∼25 km thick. The presence of basement flexures formed at several stages of the basin evolution indicates a considerable loss of lithospheric rigidity under the effect of fluid infiltration from small mantle plumes. The fluids catalyzed the eclogitization and thus increased the subsidence rate. Rapid subsidence apparently occurred in Barremian-Albian time when the basin had accumulated up to 11.5 km of sediments. Besides the Early Cretaceous event, there were, possibly several older events of rapid subsidence. This basin subsidence history, along with the evidence of steep lithospheric flexure, is a known feature of large petroleum basins. Therefore, the North Chukchi Basin may be expected to be an oil and gas producer. © 2009.

Spicer R.A.,Open University Milton Keynes | Herman A.B.,Russian Academy of Sciences
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010

Late Cretaceous megafossil floras from the palaeo-Arctic of northeastern Russia and northern Alaska are reviewed in respect of their age, composition, structure and floral dynamics. Palaeofloral correlations and comparisons are made between the two regions. Nine angiosperm-rich, predominantly Cenomanian to Coniacian, floras from the palaeo-Arctic are re-evaluated using Climate Leaf Analysis Multivariate Program (CLAMP) calibrated using a global gridded (0.5°×0.5°) climate data set derived from that used in climate modelling. Additional floras from lower palaeolatitudes were used to derive latitudinal temperature gradients: seven from N. America, five from around 30°N palaeolatitude in Europe and one from Kazakhstan. The Arctic climatic determinations, similar to previous estimates, support the existence of a northern Pacific Ocean cold gyre and a warm Arctic Ocean. At palaeolatitudes greater than 80°N floras are insufficiently diverse in woody dicot taxa to use CLAMP, but using CLAMP-derived latitudinal temperature gradients Arctic Ocean coastal environments at 70Ma and 82°N, and which supported a diverse dinosaur magafauna, are predicted to have experienced a mean annual temperature of 6.3±2.2°C, a warm month mean of 14.5±3.1°C and a cold month mean no colder than -2.0±3.9°C. All uncertainties are 2σ. The new estimates are in good agreement with a wide range of non-palaeobotanical climate proxies and render as an outlier warmer temperature estimates for the Arctic Ocean derived from the TEX86 proxy. Modelling, however, shows that land to ocean temperature gradients could have been steep. The CLAMP estimates also suggest high values for humidity and precipitation consistent with sedimentological indicators and, coupled with warm temperatures, support the existence of a persistent polar cloud cap that helped maintain high terrestrial air temperatures throughout prolonged periods (up to 5months) of winter darkness. © 2010 Elsevier B.V.

Bobylev N.,Russian Academy of Sciences
Tunnelling and Underground Space Technology | Year: 2010

The paper presents a case study of urban underground space (UUS) use in an area of Alexanderplatz in Berlin, Germany. The study analyses data on underground structures, as well as water supply, communications and sewerage. The focus of the study is quantification of UUS: volumes and depth of underground infrastructure, as well as functional use of underground structures. Data on UUS and land use has been collected in two case study areas, both of them include Alexanderplatz. The big case study area covers about half of a square kilometer and has about 700 thousand cubic meters of developed UUS. Main results are presented as diagrams: UUS use by function, distribution of underground infrastructure by depth, and volume of developed underground space per land area. Transport is the main function of underground structures in the area, and accounts for about 60% of UUS volume. Density of underground structures in the area is about 2-3 m. © 2010 Elsevier Ltd.

Magomedov M.N.,Russian Academy of Sciences
Journal of Surface Investigation | Year: 2011

Based on the pair potential of interatomic interaction, we study the dependence of various properties of diamond and silicon nanocrystals with a free surface on size, surface shape, and temperature. A model nanocrystal has the form of a parallelepiped faceted by {100} planes with a square base. The number of atoms N in the nanocrystals is varied from 5 to infinity. The Debye temperature, Gruneisen parameter, specific surface energy, isochoric derivative of specific surface energy with respect to temperature, and surface pressure are calculated as a function of the size and shape of diamond and silicon nanocrystals at temperatures ranging from 20 K to the melting point. The surface pressure Psf(N) ~ N-1/3 is much lower than the pressure calculated by the Laplace formula for similar nanocrystals for given values of density, temperature, and number of atoms. As the temperature increases from 20 K to the melting point, the isotherm Psf(N) lowers and changes the shape of the dependence on N; at high temperatures, it goes to the region of extension of small nanocrystals of diamond and silicon. © 2011 Pleiades Publishing, Ltd.

Ovid'Ko I.A.,Saint Petersburg State University | Sheinerman A.G.,Russian Academy of Sciences | Aifantis E.C.,Aristotle University of Thessaloniki
Acta Materialia | Year: 2011

A new mechanism of fracture toughness enhancement in nanocrystalline metals and ceramics is suggested. The mechanism represents the cooperative grain boundary (GB) sliding and stress-driven GB migration process near the tips of growing cracks. It is shown that this mechanism can increase the critical stress intensity factor for crack growth in nanocrystalline materials by a factor of three or more and thus considerably enhances the fracture toughness of such materials. © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Zavodinsky V.G.,Russian Academy of Sciences
International Journal of Refractory Metals and Hard Materials | Year: 2012

The density functional theory and pseudopotential method are used to study the energy barrier for migration of W and C atoms from one carbide grain to another through the cobalt binder. Calculations show that the pair WC migration is more preferable energetically than the separate migration of W and C atoms. Addition of metals (V, Cr, Ti) which segregate at the WC-Co interface, increases the energy barrier for the WC migration decreasing the WC flow responsible for growth of carbide grains. Vanadium was considered the most effective inhibitor of all atoms studied, titanium has proved as the worst one. © 2011 Elsevier Ltd. All rights reserved.

The diamond-bearing mantle keels underlying Archean cratons are a unique phenomenon of Early Precambrian geology. The common stable assemblage of the Archean TTG early continental crust and underlying subcontinental lithospheric mantle clearly shows their coupled tectogenesis, which was not repeated in younger geological epochs. One of the least studied aspects of this phenomenon is concerned with the eclogitic xenoliths carried up by kimberlite pipes together with mantle-derived nodules. The eclogitic xenoliths reveal evidence for their subduction-related origin, but the Archean crustal counterparts of such xenoliths remained unknown for a long time, and the question of their crustal source and relationships to the formation of early continental crust remained open. The Archean crustal eclogites recently found in the Belomorian Belt of the Baltic Shield are compared in this paper with eclogitic xenoliths from kimberlites in the context of the formation of both Archean subcontinental lithospheric mantle (SCLM) and early continental crust. The crustal eclogites from the Belomorian Belt are identical in mineral and chemical compositions to the eclogite nodules (group B), including their diamond-bearing varieties. The eclogite protoliths are comparable in composition with the primary melts of the Meso and Neoarchean oceanic crust, which was formed at a potential temperature of the upper mantle which exceeded its present-day temperature by 150-250 K. The reconstructed pathways of the Archean oceanic crust plunging in the upper mantle suggest that the Archean mantle was hotter than in the modern convergence settings. The proposed geodynamic model assumes coupled formation of the Archean diamond-bearing SCLM and growth of early continental crust as a phenomenon related to the specific geodynamics of that time controlled by a higher terrestrial heat flow. © 2012 Pleiades Publishing, Ltd.

Pavlov A.V.,Russian Academy of Sciences
Advances in Space Research | Year: 2012

Hourly values of the F2-layer peak density, NmF2, measured by 99 ionosonde stations near noon from 1957 to 2010 at low and middle geomagnetic latitudes of the northern and southern geographic hemispheres are used in a statistical study of the F2-region semi-annual anomaly. The equinox/winter and equinox/summer geomagnetically quiet NmF2 ratios, X and Y, taken near noon over each ionosonde for approximately the same winter, equinox, and summer solar activity conditions are analyzed. The conditional probabilities of occurrences of X and Y in intervals of X and Y, the most frequent values of X and Y, the mean expected values of X and Y, and the conditional probability to observe the F2-region semi-annual anomaly are calculated and studied for the fist time for low, moderate, and high solar activity conditions. These statistical parameters are averaged over 5°geomagnetic latitude interval in the northern and southern geographic hemispheres, and the trends in these averaged statistical characteristics of the NmF2 semi-annual anomaly are calculated and studied for the fist time. It is shown that the median approach can produce the incorrect conclusions about the absence of the NmF2 semi-annual anomaly. © 2011 COSPAR. Published by Elsevier Ltd. All rights reserved.

Yakovlev F.L.,Russian Academy of Sciences
Comptes Rendus - Geoscience | Year: 2012

Linear folding, developing in fold and thrust belts, is treated as a hierarchic system, at each level of which objects are described by special kinematic models. Geometric parameters of natural folded structures are determined by a combination of various mechanisms incorporated in the model, and a value of finite strain. Several case studies demonstrate how such data enables one to solve structural and geodynamic problems for natural objects of different size. Shortening value of two morphological types of folds is determined based on the geometry of competent layers. Application of the method to analyze the folds of the Vorontsov nappe (Greater Caucasus) determines its gravitational origin. Structural cross-sections though several tectonic zones are subdivided into relatively small domains, the geometry of which, particularly in thin-bedded flysch deposits, making it possible to identify the mechanisms of formation of both local and large structures, and also to reconstruct the pre-folded state of each domain and of the entire cross-sections. By aggregation of tectonic domains into large modules and determination of the value of shortening, we have constructed for the first time a 3D model of the present-day structure of the northwestern Caucasus, which is balanced for the whole sedimentary cover. The geometry of large structures makes it possible to validate geodynamic models. © 2012 Académie des sciences.

Kuz'min Y.O.,Russian Academy of Sciences
Izvestiya, Physics of the Solid Earth | Year: 2012

Empirical data on the spatiotemporal migration of recent deformation processes in fault zones are presented. Direct geodesic measurements reveal two types of waves, the interfault and intrafault waves. The velocity of the interfault wave is two-threefold higher than that of the intrafault wave. The phenomenological model describing the formation of autowave deformation processes is developed. The obtained nonlinear diffusion equation for the displacements of the Earth's surface is shown to be structurally similar to the well-known Kolmogorov-Petrovsky-Piskunov equation derived in the population wave theory. Satisfactory agreement between the suggested model and the geodetic measurements is demonstrated. The concept of a pseudowave is discussed, and a way to expand the developed approaches to the spatiotemporal migration of earthquakes is discussed. © 2012 Pleiades Publishing, Ltd.

Khan G.N.,Russian Academy of Sciences
Journal of Mining Science | Year: 2012

The discrete element method is employed to study rapid failure of a test rock specimen under cylindrical tensile wave effect. The author proves the effect exerted by the mechanical characteristics of rocks and the boundary conditions of the problem on the length and shape of fractures, and compares the experimental evidence with the calculation data. © 2012 Pleiades Publishing, Ltd.

Moczydlowska M.,Uppsala University | Nagovitsin K.E.,Russian Academy of Sciences
Precambrian Research | Year: 2012

A new assemblage of morphologically complex, ornamented and large organic-walled microfossils (acritarchs) from the Ura Formation in the Patom Uplift, East Siberia, is identified and taxonomically described as a continuation of the previous studies (Nagovitsin et al., 2004; Sergeev et al., 2011). Nine new species and three new genera are recognised; 10 other species are known from occurrences in the Ediacaran strata of Australia, China, the Siberian Platform (SP), and the East European Platform (EEP). The new species are morphologically advanced phenotypes, showing innovative elements of vesicle ornamentation and variable symmetry, and internal bodies within zygotic cyst-like vesicles that are indicative of the sexual reproduction stage of the microorganism. The morphological features and the preliminarily recognised cell wall ultrastructure are characteristic of phytoplankton; thus the described microfossils are identified as green microalgae. The relative age of the Ura assemblage, by comparison to microfossil records elsewhere and estimated in the regional geologic context of the Dalniaya Taiga (containing the Ura Formation) and the Zhuya (overlying) groups, is suggested to be early Ediacaran. Radiation of the Ura-type microorganisms pre-dates the records of Ediacaran microbiota from Australia (the Pertatataka association/Ediacaran Complex Acanthomorphic Palynoflora), the Siberian Platform (Khamaka-type assemblages), and the EEP (Vychegda association) but is preceded by the appearance of certain species recorded in China at the base of the Doushantuo Formation. The stratigraphic ranges of genera co-occurring in these palaeocontinents (Appendisphaera, Cavaspina, Ceratosphaeridium, Gyalosphaeridium, Labruscasphaeridium, Multifronsphaeridium, Tanarium, and Variomargosphaeridium) are extended by their lower record in the Patom Uplift and may span a major portion of the Ediacaran Period. The refined stratigraphic distribution of microfossils may provide a means for zoning the entire Ediacaran System in addition to the upper zones established in Australia. © 2011 Elsevier B.V.

The article presents a discussion and generalized analysis of in situ stress field in the outer crust of Earth. It has been found that rock masses in mining countries are generally exposed to tectonic stresses, and major horizontal stresses change nonlinearly with increase in the rock mass occurrence depth. © Pleiades Publishing, Ltd., 2012.

Gurvich A.S.,Russian Academy of Sciences
Izvestiya - Atmospheric and Ocean Physics | Year: 2012

A simple derivation of the equations describing the backscatter enhancement (BSE) effect of waves on small inhomogeneities in a randomly inhomogeneous medium is presented. The BSE effect is considered in a locally isotropic turbulent atmosphere. It is shown that a system of remote sounding of atmospheric turbulence can be constructed on the basis of BSE measurements. The scheme of a lidar for BSE measurement, along with routine lidar sounding, is proposed. With the use of models it is shown that regions of increased turbulence can be detected with such a lidar. © 2012 Pleiades Publishing, Ltd.

Pulinets S.,Russian Academy of Sciences
International Journal of Geophysics | Year: 2012

Ionospheric and atmospheric anomalies registered around the time of strong earthquakes in low-latitude regions are reported now regularly. Majority of these reports have the character of case studies without clear physical mechanism proposed. Here we try to present the general conception of low-latitude effects using the results of the recent author's publications, including also rethinking the earlier results interpreted basing on recently established background physical mechanisms of anomalies generation. It should be underlined that only processes initiated by earthquake preparation are considered. Segregation of low-latitude regions for special consideration is connected with the important role of ionospheric equatorial anomaly in the seismoionospheric coupling and specific character of low-latitude earthquake initiated effects. Three main specific features can be marked in low-latitude ionospheric anomalies manifestation: the presence of magnetic conjugacy in majority of cases, local longitudinal asymmetry of effects observed in ionosphere in relation to the vertical projection of epicenter onto ionosphere, and equatorial anomaly reaction even on earthquakes outside equatorial anomaly (i.e., 30-40 LAT). The equality of effects morphology regardless they observed over land or over sea implies only one possible explanation that these anomalies are initiated by gaseous emanations from the Earth crust, and radon plays the major role. © 2012 Sergey Pulinets.

Pavlov V.E.,Russian Academy of Sciences
Izvestiya, Physics of the Solid Earth | Year: 2012

The Meso-Cenozoic paleomagnetic poles from the Siberian platform and its folded margins, which comply with the modern technical and methodological standards, are analyzed. The analysis suggests the following conclusions. (1) The geometrical relationship between the Permo-Triassic poles of the Stable Europe and Siberian Platform prohibits the possibility of relative displacements of these platforms in the post-Paleozoic time. (2) The Mesozoic paleomagnetic poles of the Siberian Platform support the hypothesis of rigid Northern Eurasia. (3) The paleolatitudes of the Mesozoic sections located on the folded margins of the Siberian Platform closely agree with the Apparent Polar Wandering Path (APWP) for Europe. (4) The available data indicate that the vertical-axis rotation of separate local blocks within the folded margins of the Siberian Platform was a widespread phenomenon. Therefore, (1) the modern paleomagnetic data quite certainly show that consolidation of the Northern Eurasian continent was completed by the end of Permian, and, since the very beginning of the Mesozoic, the Siberian and East-European platforms have been parts of a single rigid megablock. (2) The Meso-Cenozoic segment of the APWP for Europe can be used as reference for the Siberian platform. © 2012 Pleiades Publishing, Ltd.

Karimova S.,Russian Academy of Sciences
Advances in Space Research | Year: 2012

Despite spiral eddies were first seen on the sea surface more than 40 years ago, there is still a lot of uncertainty concerning these eddies. The present paper is aimed to provide the comprehensive results on the occurrence and statistics of small-scale eddies in the three inner seas (the Baltic, Black and Caspian) using satellite synthetic aperture radar (SAR) images. The dataset used includes over 2000 medium resolution Envisat ASAR and ERS-2 SAR images obtained in 2009-2010 in the different parts of the seas mentioned. As a result of the analysis performed ∼14,000 vortical structures were detected. 71% of them were visualized due to surfactant films ("black" eddies), while 29% due to wave/current interactions ("white" eddies). Practically all the eddies detected were cyclonically rotating. Their diameter was within 1-20 km. Characteristic size of the "black" eddies in all the basins was discovered to be less than that of the "white" eddies. Characteristic eddy size for the Baltic, Black and Caspian seas proved to be strictly proportional to the values of the baroclinic Rossby radius of deformation typical for these basins. The "black" eddies did not demonstrate a significant connection with the basin- and meso-scale surface circulation of the seas. Most of the "white" eddies detected were attributed to the zones with the most intense drift currents, i.e. those along the western boundaries and (in the Baltic Sea only) in the elongated parts of the basin. © 2011 COSPAR. Published by Elsevier Ltd. All rights reserved.

Safronova U.I.,University of Nevada, Reno | Safronova U.I.,Russian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

Excitation energies of the [Xe]ns1/2, [Xe]npj, and [Xe]ndj (n≤ 12 and [Xe]=1s22s22p63s23p63d104s24p64d105s25p6) in Ba ii are evaluated. First-, second-, third-, and all-order Coulomb energies and first- and second-order Coulomb-Breit energies are calculated. Electric-dipole (6s1/2-npj, n=6-26), electric-quadrupole (6s1/2-ndj, n=5-26), and electric-octupole (6s1/2-nfj, n=4-26) matrix elements are calculated to obtain the ground-state E1, E2, and E3 static polarizabilities. Scalar polarizabilities of the ns1/2, npj, and ndj states and tensor polarizabilities of the np3/2 and ndj excited states of Ba+ are evaluated. All aforementioned matrix elements are determined using the relativistic all-order method. The hyperfine structure in Ba137 ii is also investigated. The hyperfine A and B values are determined for the first low-lying levels up to n=9. The quadratic Stark effect on hyperfine structure levels of Ba137 ii ground state is investigated. The calculated shift for the (F=2, M=0) (F=1, M=0) transition is -0.2931 Hz/(kV/cm)2, in agreement with a previous theoretical result, -0.284(3)). These calculations provide a theoretical benchmark for comparison with experiment and theory. © 2010 The American Physical Society.

Tuchina E.S.,Chernyshevsky Saratov State University | Tuchin V.V.,Russian Academy of Sciences
Laser Physics Letters | Year: 2010

Uncovered TiO2 nanoparticles were shown to provide bactericidal activity against the three pathogens: Staphylococcus aureus, Escherichia coli, and Candida albicans at irradiation by blue (405 nm) light. It was found that the combination of a photocatalyst (TiO2-nanoparticles) and a photosensitizer (methylene blue) at two-wavelength irradiation with blue (405 nm) and red (625 nm) light provides a pronounced antimicrobial effect. © 2010 by Astro Ltd.

This study was undertaken to evaluate the apparent viscosity within the vacuoles of single Saccharomyces cerevisiae cells by steady-state fluorescence anisotropy measurements of quinacrine, using wide-field fluorescence polarization microscopy combined with computer image analysis. Quinacrine was shown to be rather specifically accumulated within the vacuoles of the cells. This accumulation was effectively reversed by ATP depletion of the cells, with no detectable binding of the dye within the vacuoles. Quinacrine fluorescence anisotropy in the sucrose solutions of various viscosities obeyed the Perrin equation. The fluorescence anisotropy of quinacrine was measured in the vacuoles of 39 cells. From cell to cell, this parameter changed in the range 0.032-0.086. Using the Perrin plot as a calibration curve, apparent viscosity values of the vacuolar milieu were calculated for each cell. The population of the cells studied was heterogeneous with regard to vacuolar viscosity, which was in the range 3.5±0.4-14.06±0.64 cP. There was a characteristic distribution of the frequencies of cells with apparent viscosities within certain limits, and cells with viscosity values in the range 5-6 cP were the most frequent. No relationship was found between the sizes of the vacuoles and their apparent viscosities. © 2012 John Wiley & Sons, Ltd.

Usov N.A.,Russian Academy of Sciences
Journal of Applied Physics | Year: 2010

The low frequency hysteresis loops of superparamagnetic nanoparticles with uniaxial anisotropy are calculated as a function of the particle diameter, alternating magnetic field amplitude H0, frequency, and particle magnetic parameters both for oriented and nonoriented assemblies. The magnetic field frequency is assumed so high, f>50-100 kHz, that the mechanical rotation of a particle in surrounding medium is restricted. Thus, only the Neel-Brown magnetization relaxation process is taken into account. Pronounced dependence of the specific loss power on the particle diameter is found in the linear regime pertaining to small magnetic field amplitudes. For an oriented assembly of Co nanoparticles with optimal diameter D≈6 nm the specific power loss can be as high as 1600 W/g for typical values H0 =200 Oe and f=500 kHz. It is three times less for the corresponding nonoriented assembly. Nevertheless, using of particles with low anisotropy field, i.e., particles of soft magnetic type, seems to be preferable for the purpose of magnetic nanoparticle hyperthermia. For such an assembly the nonlinear regime can be easily accessed. Hence the hysteresis loop area increases and is comparable with its maximum possible value. © 2010 American Institute of Physics.

The author has accomplished systematization of ore fields by their geomechanical conditions based on the analysis of their tectonic structures. It is established that natural stress fields in the same type geological and tectonic structures are similar in mining regions worldwide. The author has distinguished four geomedium models differentiating the change of the rock stress state with increase in the rock occurrence depth. © 2012 Pleiades Publishing, Ltd.

Pavlenkova G.A.,Russian Academy of Sciences
Izvestiya, Physics of the Solid Earth | Year: 2012

This work presents the results of reinterpretation of the deep seismic sounding (DSS) data for the Stepnoe-Bakuriani profile and the southern part of the Volgograd-Nakhichevan profile, carried out using new processing methods. Both the profiles cut the trend of the Greater Caucasus. They were acquired in the 1960s by multichannel continuous profiling, which provided high-quality records; however, only the travel-time curves for the main wave types have survived till now. The waves recorded on these profiles have a rather complex origin and their processing by the methods existing at that time was a challenge. At present, the modern computer technologies allowed us to invert the preserved travel-time curves for the velocity models of the Earth's crust and the very tops of the mantle down to 80 km. It is shown that the crustal thickness increases under the Greater Caucasus up to 50-60 km and this increase is not gradual, as implied in the previous reconstructions, but occurs through a system of deep dislocations. Traced by the oblique reflections and sharply contrasting seismic velocities, these dislocations extend into the crust. An extended, north-dipping boundary is revealed at a depth of 50-80 km. The velocity model of the Greater Caucasian crust exhibits slightly decreased velocities compared to the surrounding platform regions. At the same time, the velocities sharply increase in the middle and even upper parts of the crust in the Kura depression. © 2012 Pleiades Publishing, Ltd.

Reshmin S.A.,Russian Academy of Sciences
IEEE Transactions on Automatic Control | Year: 2015

The number of switchings is an important parameter characterizing the complexity of the bang-bang optimal control. A time-optimal control problem for Lagrangian single-degree-of-freedom (single-DOF) systems is considered. The system describes the dynamics of an inertial object under the action of a bounded control force and an external force given as a function of the coordinate. The terminal set consists of the zero point in the phase plane. We analyze the possible motion time along the optimal trajectories with two switchings and obtain corresponding necessary optimality condition. As a result, we suggest a criterion (tool) for quick checking the absence of such trajectories in the phase plane. In this case, the time-optimal feedback control has the simplest structure: the number of switchings is not greater than one for any initial conditions. The corresponding examples are presented. © 2015 IEEE.

The multilayer relaxation model of Mössbauer spectra of an ensemble of single-domain particles has been generalized to the case of the presence of the electric field gradient on nuclei with a chaotic orientation of its principal axes. The generalized model makes it possible to take into account the physical mechanisms of the formation of the hyperfine structure of the spectra in the real situation and to numerically describe the qualitative features of the temperature evolution of the spectra from symmetric magnetic sextet to the quadrupole doublet of lines, which is observed in most experimental spectra of 57Fe nuclei in magnetic nanoparticles. © 2011 Pleiades Publishing, Ltd.

Goncharov V.P.,Russian Academy of Sciences
Journal of Experimental and Theoretical Physics | Year: 2011

The mechanisms and structural elements of an instability whose development results in the collapse of flow fragments have been studied in the scope of the Hamilton version of the "shallow water" 3D model on a slope. The study indicated that the 3D model differs from its 2D analog in a more varied set of collapsing solutions. In particular, the solutions describing anisotropic collapse, during which the area of a collapsing fragment in contact with the slope contracts into a segment rather than a point, exist together with the solutions describing radially symmetric (isotropic) collapse. © Pleiades Publishing, Inc., 2011.

Heikkila T.T.,Aalto University | Volovik G.E.,Russian Academy of Sciences
JETP Letters | Year: 2011

We consider the dimensional crossover in the topological matter, which involves the transformation of different types of topologically protected zeroes in the fermionic spectrum. In the considered case, the multiple Dirac (Fermi) point in quasi 2-dimensional system evolves into the flat band on the surface of the 3-dimensional system when the number of atomic layers increases. This is accompanied by formation of the spiral nodal lines in the bulk. We also discuss the topological quantum phase transition at which the surface flat band shrinks and changes its chirality, while the nodal spiral changes its helicity. © 2011 Pleiades Publishing, Ltd.

Volovik G.E.,Aalto University | Volovik G.E.,Russian Academy of Sciences
JETP Letters | Year: 2011

We discuss the dispersionless spectrum with zero energy in the linear topological defects-vortices. The flat band emerges inside the vortex living in the bulk medium containing topologically stable Fermi points in momentum space. The boundaries of the flat band in the vortex are determined by projections of the Fermi points in bulk to the vortex axis. This bulk-vortex correspondence for flat band is similar to the bulk-surface correspondence discussed earlier in the media with topologically protected lines of zeroes. In the latter case the flat band emerges on the surface of the system, and its boundary is determined by projection of the bulk nodal line on the surface. © 2011 Pleiades Publishing, Ltd.

In the vacuoles of Saccharomyces cerevisiae yeast cells, vividly moving insoluble polyphosphate complexes (IPCs) <1 μm size, stainable by a fluorescent dye, 4,6- diamidino-2-phenylindole (DAPI), may appear under some growth conditions. The aim of this study was to quantitatively characterize the movement of the IPCs and to evaluate the viscosity in the vacuoles using the obtained data. Studies were conducted on S. cerevisiae cells stained by DAPI and fluorescein isothyocyanate-labelled latex microspheres, using fluorescence microscopy combined with computer image analysis (ImageJ software, NIH, USA). IPC movement was photorecorded and shown to be Brownian motion. On latex microspheres, a methodology was developed for measuring a fluorescing particle's two-dimensional (2D) displacements and its size. In four yeast cells, the 2D displacements and sizes of the IPCs were evaluated. Apparent viscosity values in the vacuoles of the cells, computed by the Einstein-Smoluchowski equation using the obtained data, were found to be 2.16 ± 0.60, 2.52 ± 0.63, 3.32 ± 0.9 and 11.3 ± 1.7 cP. The first three viscosity values correspond to 30-40% glycerol solutions. The viscosity value of 11.3 ± 1.7 cP was supposed to be an overestimation, caused by the peculiarities of the vacuole structure and/or volume in this particular cell. This conclusion was supported by the particular quality of the Brownian motion trajectories set in this cell as compared to the other three cells. Copyright © 2010 John Wiley & Sons, Ltd.

Artyushkov E.V.,Russian Academy of Sciences
Russian Geology and Geophysics | Year: 2012

As evidenced by plentiful data, most of the large recent positive topographic features formed as a result of a dramatically accelerated crustal uplift in the Pliocene-Quaternary after a relatively stable period (~100 Myr in most of the regions). The methods used are illustrated by the well-studied large neotectonic crustal uplifts on the Tibetan Plateau and in the Himalayas. Farther north, neotectonic uplifts with amplitudes of several hundred meters to several kilometers spread over a vast area from Central and Northeast China in the south to the Taimyr Peninsula and Northeastern Asia in the north. They are often attributed to the India-Asia plate collision which began ~50 Ma.Most of the uplifts in these regions have formed only during the last few Myr, unaccompanied by significant crustal shortening. Therefore, the large neotectonic crustal uplifts can be explained by a decrease in the lithospheric density. One of the causes was the rapid convective replacement of the lower part of the denser mantle lithosphere by the asthenosphere or mantle plume. This became possible owing to a drastic weakening of the mantle lithosphere under the influence of asthenospheric fluids. In some areas, a considerable asthenospheric top uplift is evidenced by seismic tomography data.The lower mantle lithosphere (~50-100 km thick) was replaced by the asthenosphere underneath the neotectonic crustal uplifts of ~1.0 km in Central Asia. Areas with a thick lithosphere were affected by relatively small neotectonic uplifts, strongly nonuniform in space. They point to metamorphism with mafic-rock expansion in the lower crust upon the infiltration of an asthenospheric fluid. The large crustal uplifts which formed on the continents in the Pliocene and Pleistocene indicate large-scale quasi-synchronic supply of the mantle fluid to their lithosphere. © 2012.

Trubitsyn V.P.,Russian Academy of Sciences
Izvestiya, Physics of the Solid Earth | Year: 2012

The modern concepts of the rheology of viscous mantle and brittle lithosphere, as well as the results of the numerical experiments on the processes in a heated layer with a viscosity dependent on pressure, temperature, and shear stress, are reviewed. These dependences are inferred from the laboratory studies of olivine and measurements of postglacial rebound (glacial isostatic adjustment) and geoid anomalies. The numerical solution of classical conservation equations for mass, heat, and momentum shows that thermal convection with a highly viscous rigid lithosphere develops in the layer with the parameters of the mantle with the considered rheology under a temperature difference of 3500 K, without any special additional conditions due to the self-organization of the material. If the viscosity parameters of the lithosphere correspond to dry olivine, the lithosphere remains monolithic (unbroken). At a lower strength (probably due to the effects of water), the lithosphere splits into a set of separate rigid plates divided by the ridges and subduction zones. The plates submerge into the mantle, and their material is involved in the convective circulation. The results of the numerical experiment may serve as direct empirical evidence to validate the basic concepts of the theory of plate tectonics; these experiments also reveal some new features of the mantle convection. The probable structure of the flows in the upper and lower mantle (including the asthenosphere), which shows the primary role of the lithospheric plates, is demonstrated for the first time. © 2012 Pleiades Publishing, Ltd.

Legalov A.A.,Russian Academy of Sciences
Paleontological Journal | Year: 2012

New genera and species of curculionid beetles from the Baltic amber, Pseudoglaesotropis martynovi gen. et sp. nov. (Anthribidae), Palaeometrioxena zherikhini gen. et sp. nov. (Belidae), Eocenorhynchites vossi gen. et sp. nov. (Rhynchitidae), and Archaeosciaphilus marshalli gen. et sp. nov. (Curculionidae), are described. © 2012 Pleiades Publishing, Ltd.

Krasovsky V.L.,Russian Academy of Sciences
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2010

An exact solution of Maxwell-Vlasov equations describing a stationary transverse wave with trapped charged particles is analyzed. In the absence of a background plasma, the phase velocity of such a wave is always less than speed of light. Physical structure of the wave looks most simply in the wave frame of reference. In this frame, the constructed solution corresponds to one of the simplest force-free equilibrium plasma configurations of the type of uniformly sheared current sheets and self-consistent magnetostatic field. In the presence of the background plasma, a simple condition for existence of the waves with sublight velocities is established. © 2010 Elsevier B.V. All rights reserved.

Kalachev A.,Russian Academy of Sciences
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

Pulse shaping in a narrowband single-photon source based on cavity-enhanced spontaneous parametric down-conversion is analyzed. The scheme for pulse shaping is developed such that the wave form (both amplitude and phase) of heralded photons can be fully controlled by that of the pump pulse. It is shown that the developed scheme allows one to avoid additional losses introduced by amplitude modulators, thereby achieving the highest possible heralding efficiency. © 2010 The American Physical Society.

Lemasters J.J.,Medical University of South Carolina | Lemasters J.J.,Russian Academy of Sciences
Redox Biology | Year: 2014

Mitophagy (mitochondrial autophagy), which removes damaged, effete and superfluous mitochondria, has several distinct variants. In Type 1 mitophagy occurring during nutrient deprivation, preautophagic structures (PAS) grow into cup-shaped phagophores that surround and sequester individual mitochondria into mitophagosomes, a process requiring phosphatidylinositol-3-kinase (PI3K) and often occurring in coordination with mitochondrial fission. After sequestration, the outer compartment of the mitophagosome acidifies, followed by mitochondrial depolarization and ultimately hydrolytic digestion in lysosomes. Mitochondrial damage stimulates Type 2 mitophagy. After photodamage to single mitochondria, depolarization occurs followed by decoration and then coalescence of autophagic LC3-containing structures on mitochondrial surfaces. Vesicular acidification then occurs. By contrast to Type 1 mitophagy, PI3K inhibition does not block Type 2 mitophagy. Further, Type 2 mitophagy is not associated with phagophore formation or mitochondrial fission. A third form of self-eating of mitochondria is formation of mitochondria-derived vesicles (MDVs) enriched in oxidized mitochondrial proteins that bud off and transit into multivesicular bodies. Topologically, the internalization of MDV by invagination of the surface of multivesicular bodies followed by vesicle scission into the lumen is a form of microautophagy, or micromitophagy (Type 3 mitophagy). Cell biological distinctions are the basis for these three types of mitophagy. Future studies are needed to better characterize the molecular and biochemical differences between Types 1, 2 and 3 mitophagy. © 2014 The Author.

Retinal pigment epithelium (RPE) cells that have the unique ability to reprogram retinal cells in vivo were analyzed in the adult newt. Our own data and that available in the literature on the peculiarities of the biology of these cells (from morphology to molecular profile, which can be associated with the capability of phenotype change) were summarized. It was established that the molecular traits of specialized and poorly differentiated cells are combined in RPE of the adult newt. It was registered that persistent (at a low level) proliferation and rapid change of specific cytoskeleton proteins can contribute to the success of RPE cell reprogramming in the neuronal direction. Each of the considered factors of competence for reprogramming can be found for animal RPE, whose cells are not able in vivo to change the phenotype to a neuronal one; however, their totality (supported by the epigenetic state permissive for conversion) is probably an internal property of only newt RPE. © 2015, Pleiades Publishing, Inc.

Pitjeva E.V.,Russian Academy of Sciences | Pitjev N.P.,Saint Petersburg State University
Monthly Notices of the Royal Astronomical Society | Year: 2013

The high precision of the latest version of the planetary ephemeris Ephemerides of the Planets and the Moon (EPM2011) enables one to explore more accurately a variety of small effects in the Solar system. The processing of about 678 thousand of position observations of planets and spacecraft for 1913-2011 with the predominance of modern radar measurements resulted in improving the PPNparameters, dynamic oblateness of the Sun, secular variation of the heliocentric gravitational constant GM⊙, and the stronger limits on variation of the gravitational constant G. This processing made it possible to estimate the potential additional gravitational influence of dark matter on the motion of the Solar system bodies. The density of dark matter dm, if any, turned out to be substantially below the accuracy achieved by the present determination of such parameters. At the distance of the orbit of Saturn the density ρdm is estimated to be under 1.1 × 10-20 g cm-3, andthe mass of dark matter in the area inside the orbit of Saturn is less than 7.9 × 10-11 M⊙ even takinginto account its possible tendency to concentrate in the centre. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.

Bobylev V.V.,Saint Petersburg State University | Bajkova A.T.,Russian Academy of Sciences
Monthly Notices of the Royal Astronomical Society | Year: 2013

To estimate the parameters of the Galactic spiral structure - namely the pitch angle i and the number of spiral arms - data on Galactic masers with known trigonometric parallaxes were used. We applied the well-known method based on analysis of the 'position angle - distance logarithm' diagram. Estimates of the pitch angle i obtained from four segments of different arms belonging to the global Galactic structure are self-consistent and close to i=-13° ± 1°. The segment which is most interesting is that of the Outer arm. It contains only three masers. Hence, in order to obtain correct estimates, we also used the data on 12 very young star clusters with distances determined by Camargo et al. from infrared photometry. The estimates obtained allow us to conclude in favour of the four-armed model of the Galactic spiral structure. © 2013 The Authors.

Phase transitions in the three-dimensional antiferromagnetic Heisenberg model on a layered triangular lattice with the next-nearest neighbor interactions have been studied by the histogram Monte Carlo method. Phase transitions in this model have been studied in the range of the next-nearest neighbor interactions from 0. 0 to 1. 0. The first-order phase transition has been revealed in the considered interval in the studied model. © 2011 Pleiades Publishing, Ltd.

Nikolaev V.P.,Russian Academy of Sciences
Aviation Space and Environmental Medicine | Year: 2013

Background: As is known, there are many cases when symptoms of decompression sickness (DCS) in divers appear extremely late (> 15 h after completion of diving) and there is much evidence for unsuccessful treatment of DCS by means of recompression. In this study, we have tried to gain insight into the roots of these phenomena. Methods: Using the mathematical model of extravascular gas bubble dynamics, we have analyzed the time history of such bubbles under typical air dives and recompression procedures used for DCS treatment. Results: If the parameters defining the bubble dynamics remained invariable, the bubbles formed in different body tissues would reach their maximal sizes within the well-known latency time range for DCS onset, and later these bubbles would dissolve completely during standard recompression procedures. Actually, the parameters defining the processes of bubble growth and dissolution vary with time. Conclusions: The symptoms of DCS that arise with abnormal latency may be induced by bubbles that grow a very long time in some tissues when the rate of nitrogen washout from them is reduced significantly due to vascular bubbles blocking the microcirculation. An abnormal latency of DCS onset may also appear when the negative effects of the initially asymptomatic bubbles are detected during the very slow process of their dissolution. The failure of recompression to resolve this DCS probably happens when the previously formed bubbles are large and located in tissues with less permeability so that they dissolve very slowly. © by the Aerospace Medical Association, Alexandria, VA.

A report is given about Hydrozoa collected at depths between 455 and 3666. m in the Sea of Japan during the Russian-German expedition on R/V Akademik M.A. Lavrentyev. Ten species were found, with four of them being typical bathyal-abyssal and abyssal zones. A new species, Opercularella angelikae, is described, and it was the dominant hydroid in samples from 970 to 3660. m. Four eurybathic species characteristics of the Sea of Japan were sampled between 455 and 582. m. Abyssal (pseudoabyssal after Andriashev, 1979) hydroid fauna in the Sea of Japan is reported. The hypothesis that an exclusively deep-water fauna is lacking in abyssal regions of the Sea of Japan is disputed. The author's personal opinion considered concerning the borders of 1000. m between shallow and deep hydrozoan species in the Sea of Japan. © 2012 Elsevier Ltd.

Karu T.I.,Russian Academy of Sciences
IUBMB Life | Year: 2010

This article reviews the current knowledge in photobiology and photomedicine about the influence of monochromatic, quasimonochromatic, and bread-band radiation of red-to-near infrared (IR-A) part on solar spectrum upon mammalian cells and human skin. The role of cytochrome c oxidase as the photoacceptor and photosignal transducer is underlined and its photosensitivity at certain circumstances is discussed. The role of ATP as a critical signaling molecule is discussed. © 2010 IUBMB.

Markusova V.,Russian Academy of Sciences
Acta Informatica Medica | Year: 2012

The aim of the paper is to overview the leading information processing domain in Russia and Eastern Europe, namely All Russian Institute for Scientific and Technical Information (VINITI) of the Russian Academy of Sciences. Russian science structure is different from that in the Western Europe and the US. The main aim of VINITI is to collect, process and disseminate scientific information on various fields of science and technology, published in 70 countries in 40 languages, selected from books, journals, conference proceedings, and patents. A special attention is given to the journal selection and depositing manuscripts (a kind of grey literature), an important source for Russian research. VINITI has created the largest database containing about 30 million records dating back to 1980. About 80,000-100,000 new records are added monthly. VINITI publishes the Journal Abstract (JA) on 19 fields of science, including medicine, containing about a million publications annually. Two thirds of these records are foreign and 36.7% - Russian sources. © AVICENA 2012.

Godovsky D.,Russian Academy of Sciences
Organic Electronics: physics, materials, applications | Year: 2011

Polymer solar cell operation is based on the photoinduced charge transfer between polymer donor and acceptor. Marcus theory of electron transfer was applied to calculate the upper limit of the polymer solar cell efficiency in no-recombination approximation. Such calculation becomes possible by optimizing the position of the acceptor LUMO for any band gap value, which in turn maximizes the multiplication product of photocurrent, calculated according to Marcus theory and Voc, which is determined by the difference between the acceptor LUMO and the polymer HOMO. Ultimate efficiency of polymer solar cell critically depends on λ -parameter describing reorientation of neighbouring dipoles in Marcus theory. The model provides a method for selection of optimal acceptor molecules for use in the polymer solar cells. © 2010 Elsevier B.V. All rights reserved.

Gladenkov Y.B.,Russian Academy of Sciences
Stratigraphy and Geological Correlation | Year: 2013

Several Cenozoic orogenic phases marked by deformations and rearrangement of geological structures, by unconformities and hiatuses, and by the cyclicity of ancient sedimentary and volcanic formations are distinguished in the vast territory of a transitional zone between Northeast Asia and the Pacific, from Sakhalin in the south to Chukotka in the north. © 2013 Pleiades Publishing, Ltd.

Legalov A.A.,Russian Academy of Sciences
Insect Science | Year: 2012

The first synopsis of Mesozoic weevils (Curculionoidea: Coleoptera) is presented. Changes of family, genera and species abundance during the Mesozoic revealed three distributional patterns. The Jurassic (Karatau) fauna was dominated by the Nemonychidae. During the Early Cretaceous (beginning at the Jurassic/Cretaceous border), the Ithyceridae was the prevalent group with a significant role played by the Nemonychidae. In the Late Cretaceous (Cenomanian and Turonian), the major groups were the Curculionidae and Brentidae. Obviously, the change of weevil fauna during this period was due to the expansion of the angiosperms, which provided multiple niches in their vegetative and reproductive organs for weevil development. © 2012 The Author Insect Science © 2012 Institute of Zoology, Chinese Academy of Sciences.

Neverov A.D.,Moscow State University | Lezhnina K.V.,Moscow State University | Kondrashov A.S.,Michigan State University | Bazykin G.A.,Russian Academy of Sciences
PLoS Genetics | Year: 2014

Reassortments and point mutations are two major contributors to diversity of Influenza A virus; however, the link between these two processes is unclear. It has been suggested that reassortments provoke a temporary increase in the rate of amino acid changes as the viral proteins adapt to new genetic environment, but this phenomenon has not been studied systematically. Here, we use a phylogenetic approach to infer the reassortment events between the 8 segments of influenza A H3N2 virus since its emergence in humans in 1968. We then study the amino acid replacements that occurred in genes encoded in each segment subsequent to reassortments. In five out of eight genes (NA, M1, HA, PB1 and NS1), the reassortment events led to a transient increase in the rate of amino acid replacements on the descendant phylogenetic branches. In NA and HA, the replacements following reassortments were enriched with parallel and/or reversing replacements; in contrast, the replacements at sites responsible for differences between antigenic clusters (in HA) and at sites under positive selection (in NA) were underrepresented among them. Post-reassortment adaptive walks contribute to adaptive evolution in Influenza A: in NA, an average reassortment event causes at least 2.1 amino acid replacements in a reassorted gene, with, on average, 0.43 amino acid replacements per evolving post-reassortment lineage; and at least ~9% of all amino acid replacements are provoked by reassortments. © 2014 Neverov et al.

Perlovich G.L.,Russian Academy of Sciences
Molecular Pharmaceutics | Year: 2014

This paper considers fundamental aspects determining the processes of drug compound dissolution and distribution in solvents/systems modeling biological media. Special attention is paid to the complex analysis of thermodynamic functions of sublimation and solvation/hydration processes during structural modification of lead/hit compounds and their influence on dissolution processes. The paper shows that at the first stages of drug design it is necessary to develop algorithms of optimizing the properties determining absorption, distribution, metabolism, and excretion (ADME) characteristics of molecules: in particular, diffusion flux density through lipophilic membranes. Using sulfonamides and nonsteroidal anti-inflammatory drugs (NSAIDs) as an example, we have demonstrated the efficiency of approaches to manipulating thermodynamic functions of the basic processes that result from delivering compounds to the points of their operation. We have formulated several criteria of compound selection for further tests. © 2013 American Chemical Society.

Goryachev N.A.,Russian Academy of Sciences
Russian Geology and Geophysics | Year: 2014

The mineral and geochemical compositions of noble-metal (first of all, gold) deposits of the Fennoscandian, Siberian, and Northeast Asian orogenic belts are considered. These deposits are of several types: Au (disseminated Au-sulfide and Au-quartz), Au-Bi, Au-Ag, Au-Sb, Ag-Sb, Au-Sb-Hg, and Ag-Hg. They formed in different geodynamic settings as a result of the active motion of crustal tectonic blocks of different nature. Subduction processes (both at the front and at the rear of continent-marginal and island-arc magmatic arcs) resulted in Au-Ag, Ag-Sb, Ag-Hg, Au-Sb-Hg, and Au-Bi deposits. Collision events gave rise to Au and Au-Bi deposits. Intraplate continental rifting and formation of orogenic belts along the boundaries of block (plate) sliding led to the origin of Au and Au-Bi ores in association with Au-Ag, Au-Sb-Hg, and complex ores. In all cases, the formation of noble-metal mineralization was accompanied by magmatism of different types and metamorphism. Because of this diversity of ores, there is no single concept of the genesis of noble-metal mineralization. Several competing models of genesis exist: hydrothermal-metamorphic, pluton-metamorphic, plutonic, activity of mantle fluid flows, and multistage concentration during the crust-mantle interaction with the leading role of sedimentary complexes. © 2014 Elsevier Inc.

Glazunov A.V.,Russian Academy of Sciences
Izvestiya - Atmospheric and Ocean Physics | Year: 2014

Stably stratified turbulent flows over surfaces with explicit roughness elements simulating an urban built-up area have been calculated using an LES model. A method of conducting numerical experiments allowing turbulent flows with specified values of the Obukhov scale L to reach a quasisteady state at the surface has been proposed. It has been shown that, to calculate both temperature and wind-velocity profiles over such objects, one can use the same universal dependences that are used for a flat surface. It has been found that stable stratification does not affect the roughness parameter z 0u and the displacement height D. © 2014 Pleiades Publishing, Ltd.

Khomentovsky V.V.,Russian Academy of Sciences
Russian Geology and Geophysics | Year: 2014

The Late Neoproterozoic sediments of the Yenisei Ridge formed in several isolated basins. These sediments are correlated, and the composite section of this age in the region is described. Two age limits are of extreme importance: pre-Chapa (650 Ma) and pre-Vendian (600 Ma). The former, observed in a much larger area, predominates. The great importance of the pre-Chapa transformation becomes evident owing to its coevality with the Marino-Nantuo global glaciation and the preceding tectonic events. This glaciation was immediately followed by a significant biotic event that gave rise to the Doushantuo-Pertatataka microfossil assemblage and, afterward, Ediacaran fauna. The Chapa Group is proposed as a prototype of the Angarian-a unit of the General Late Precambrian scale, which is of the same rank as the Vendian. According to these data, the main Late Neoproterozoic units are the Baikalian, Angarian, and Vendian. © 2014.

Chukhovskii F.,Russian Academy of Sciences
Acta Crystallographica Section A: Foundations of Crystallography | Year: 2011

An attempt is made to go beyond the distorted-wave Born approximation addressed to the grazing-incidence small-angle X-ray (GISAX) scattering from a random rough surface. The integral wave equation adjusted with the Green function formalism is applied. To find out an asymptotic solution of the non-averaged integral wave equation in terms of the Green function formalism, the theoretical approach based on a self-consistent approximation for the X-ray wavefunction is elaborated. Such an asymptotic solution allows one to describe the reflected X-ray wavefield everywhere in the scattering (θ,φ) angular range, in particular below the critical angle θcr for total external reflection (θ is the grazing scattering angle with the surface, φ is the azimuth scattering angle; θ0 is the grazing incidence angle). Analytical expressions for the reflected GISAX specular and diffuse scattering waves are obtained using the statistical model of a random Gaussian surface in terms of the r.m.s. roughness and two-point cumulant correlation function. For specular scattering the conventional Fresnel expression multiplied by the Debye-Waller factor is obtained. For the reflected GISAX diffuse scattering the intensity of the Rdif(θ,φ) scan is written in terms of the statistical scattering factor η̃(θ, θ0) and Fourier transform of the two-point cumulant correlation function. To be specific for isotropic solid surfaces, the statistical scattering factor η̃(θ, θ0) and Fourier transform of the two-point cumulant correlation function parametrically depend on the root-mean-square roughness σ [η̃(θ, θ0 = 0 for σ = 0] and cumulant correlation length ℓ, respectively. The reflected Rdif(θ,φ) scans are numerically simulated for the typical-valued {θ0,σ,ℓ} parameters array. © 2011 International Union of Crystallography.

Allakhverdiev S.I.,Russian Academy of Sciences
Photosynthesis research | Year: 2012

In this brief report, we provide a perspective on an international conference "Photosynthesis Research for Sustainability-2011", held in Baku, Azerbaijan, during July 24-30, 2011 ( http://www.photosynthesis2011.cellreg.org/ ). At this conference, awards were given to nine young investigators; they are recognized in this Report. We have also included here some photographs to show the pleasant ambiance at this conference. (See http://www.photosynthesis2011.cellreg.org/Photos.php and http://www.life.illinois.edu/govindjee/g/Photo/Baku.html for more photographs taken by the authors as well as by others.) We invite the readers to the next conference on "Photosynthesis Research for Sustainability-2013" to be held in May or June 2013, in Baku, Azerbaijan. Information will be posted at: http://www.photosynthesis2013.cellreg.org/ .

Mergelov N.S.,Russian Academy of Sciences
Eurasian Soil Science | Year: 2014

The properties and spatial distribution of soils and soil-like bodies in valleys of the coastal Larsemann Hills and Vestfold Hills oases-poorly investigated in terms of the soil areas of East Antarctica-are discussed. In contrast to Dry Valleys-large continental oases of Western Antarctica-the studied territory is characterized by the presence of temporarily waterlogged sites in the valleys. It is argued that the deficit of water rather than the low temperature is the major limiting factor for the development of living organisms and the pedogenesis on loose substrates. The moisture gradients in the surface soil horizons explain the spatial distribution of the different soils and biotic complexes within the studied valleys. Despite the permanent water-logging of the deep suprapermafrost horizons of most of the soils in the valleys, no gley features have been identified in them. The soils of the wet valleys in the Larsemann Hills oasis do not contain carbonates. They have a slightly acid or neutral reaction. The organic carbon and nitrogen contents are mainly controlled by the amount of living and dead biomass rather than by the humic substances proper. The larger part of the biomass is concentrated inside the mineral soil matrix rather than on the soil surface. The stresses caused by surface drying, strong winds, and ultraviolet radiation prevent the development of organisms on the surface of the soil and necessitate the search for shelter within the soil fine earth material (endoedaphic niche) or under the gravelly pavement (hypolithic niche). In the absence of higher plants, humified products of their decomposition, and rainwater that can wash the soil profile and upon the low content of silt and clay particles in the soil material, "classical" soil horizons are not developed. The most distinct (and, often, the only diagnosed) products of pedogenesis in these soils are represented by organomineral films on the surface of mineral particles. © 2014 Pleiades Publishing, Ltd.

Puchkov L.A.,Russian Academy of Sciences
Gornyi Zhurnal | Year: 2014

Forecasts of global energetic consumption (coal, oil, gas and uranium), which have the defining value for planning of development of global economics, are based on long-term analysis of internal parameters and interconnections of global system of mineral-energetic consumption. Such methods are valuable, because they define the dynamics of development of economics of countries, regions, economic blocks and weight of constituents of mineral products in total mineral-energetic balance of modern economics. However, such differentiated methods do not take into account the system-wide regularities of development of mineral-energetic consumption and lead to wrong results on the global level. In the proposed forecast methods, world mineral-energetic consumption is considered as unite system, which movement should correspond to main principle of natural evolution - principle of least action. This means, that mineral-energetic consumption is limited by the possibilities of natural provision of development of civilization and should correspond to the main tasks of natural evolution. This article shows that such main task is provision of growth of Earth population, which nowadays is on the stage of intensive hyperbolic growth. There was made a definition that purposes of growth of global economics, defined by economic indices, are in contradiction with natural evolution and lead to economic crisis. According to this, economic crisis is mostly defined by excess mineral-energetic consumption, when remaining reasons are secondary. On the basis of this, there is given the forecast of economic crisis of 2014-2023, which potential value has already been formed as a result of incorrectly defined purposes. There is also given the long-term forecast of mineral-energetic consumption for the period from 2023 till 2070. There is given the comparative analysis with existing forecasts and, in particular, with forecast of US Energy Information Administration (EIA). There is shown that EIA forecast leads to further excess consumption of mineral-energetic products and can't be realized in connection with existing deviations from natural development purposes.

Klyuchevskii A.V.,Russian Academy of Sciences
Journal of Asian Earth Sciences | Year: 2014

The current geodynamics and tectonophysics of the Baikal rift system (BRS) as recorded in lithospheric stress and strain are discussed in the context of self organization of nonlinear dissipative dynamic systems and nonlinear media. The regional strain field inferred from instrumental seismic moment and fault radius data for almost 70,000 MLH≥2.0 events of 1968 through 1994 shows a complex pattern with zones of high strain anisotropy in the central part and both flanks of the rift system (the South Baikal, Hovsgöl, and Muya rift basins, respectively). The three zones of local strain anisotropy highs coincide with domains of predominantly vertical stress where earthquakes of different magnitudes are mostly of normal slip geometry. Pulse-like reversals of principal stresses in the high-strain domains appear to be nonlinear responses of the system to subcrustal processes. In this respect, the BRS lithosphere is interpreted in terms of the self organization theory as a geological dissipative system. Correspondingly, the domains of high strain anisotropy and stress change, called rifting attractor structures (RAS), are the driving forces of its evolution. The location and nonlinear dynamics of the rifting attractors have controlled lithospheric stress and strain of the rift system over the period of observations, and the same scenario may have been valid also in the Mesozoic-Cenozoic rifting history. The suggested model of a positive-feedback (fire-like) evolution of nonlinear dynamical systems with rifting attractors opens a new perspective on the current geodynamics and tectonophysics of the Baikal rift system. © 2014 Elsevier Ltd.

Lyubushin A.A.,Russian Academy of Sciences
Natural Hazards | Year: 2014

A new method of dynamic estimate of seismic danger is presented which is based on estimating multifractal properties of low-frequency seismic noise. The efficiency of the method is illustrated by the analysis of seismic noise from broadband seismic network F-net in Japan. The analysis of multifractal properties of low-frequency seismic noise from Japan seismic network F-net since the beginning of 1997 allowed a hypothesis about approaching Japan Islands to a future seismic catastrophe to be formulated at the middle of 2008. The base for such a hypothesis was statistically significant decreasing of multi-fractal singularity spectrum support width mean value. The peculiarities of correlation coefficient estimate within 1 year time window between median values of singularity spectra support width and generalized Hurst exponent allowed to make a decision that starting from July 2010, Japan come to the state of waiting strong earthquake. This prediction of Tohoku mega-earthquake, initially with estimate of lower magnitude as 8.3 only (at the middle of 2008) and further on with estimate of the time beginning of waiting earthquake (from the middle of 2010), was published in advance in a number of scientific articles and abstracts on international conferences. The analysis of seismic noise data after Tohoku mega-earthquake indicates increasing probability of the 2nd strong earthquake within the region where the north part of Philippine Sea plate is approaching island Honshu (Nankai Trough). This region is characterized by relatively low values of singularity spectrum support width which is an indicator of seismic danger. In one paper (Sobolev in Izv Phys Solid Earth 47:1034-1044, 2011), the low-frequency seismic noise at the same range of periods was investigated retrospectively using data from the stations of broadband network IRIS which are located around the epicenter of Tohoku mega-earthquake with a distance up to 1,200 km. It was shown that the variance of the noise and the number of high-amplitude asymmetric impulses were grown dramatically before the event for stations which are located within the radius up to 500 km from the epicenter. © 2013 Springer Science+Business Media Dordrecht.

Uversky V.N.,Indiana University | Uversky V.N.,Russian Academy of Sciences
FEBS Journal | Year: 2010

Misfolding and subsequent self-assembly of protein molecules into various aggregates is a common molecular mechanism for a number of important human diseases. Curing protein misfolding pathologies and designing successful drugs for the inhibition or reversal of protein aggregation depends on understanding the peculiarities of the misfolding process. Protein aggregation is a very complex process characterized by a remarkable polymorphism, where soluble amyloid oligomers, amyloid fibrils and amorphous aggregates are found as final products. This polymorphism is associated with the existence of multiple independent and competing assembly pathways leading to aggregation. Regardless of the aggregation mechanism, soluble oligomers are inevitably formed during the self-association process. Some of these oligomers are now considered to be major initiators of the neurodegenerative cascades of corresponding diseases. However, not all oligomers are equally harmful, and several amyloidogenic proteins have been shown to form nontoxic oligomers, some of which were efficient fibrillation inhibitors. Unfortunately, the information on the structural properties of soluble oligomers and the mechanisms of their formation, interconversion and toxicity is sparse. This review provides an overview of some topics related to soluble oligomers and represents several illustrative examples of toxic, nontoxic, productive and off-pathway amyloid oligomers. © 2010 FEBS.