Showing papers by "Russian Academy of Sciences published in 1985"
TL;DR: In this article, the authors estimate the rate of anomalous electroweak baryon-number nonconserving processes in the cosmic plasma and find that it exceeds the expansion rate of the universe at T > (a few) × 102 GeV.
2,079 citations
TL;DR: It is found that cyclic GMP acting from the inner side of the membrane markedly increases the cationic conductance of such patches of the rod outer segment in a reversible manner, while Ca2+ is ineffective.
Abstract: Vertebrate rod photoreceptors hyperpolarize when illuminated, due to the closing of cation-selective channels in the plasma membrane. The mechanism controlling the opening and closing of these channels is still unclear, however. Both 3′, 5′-cyclic GMP1,2 and Ca2+ ions3 have been proposed as intracellular messengers for coupling the light activation of the photopigment rhodopsin to channel activity and thus modulating light-sensitive conductance. We have now studied the effects of possible conductance modulators on excised ‘inside-out’ patches from the plasma membrane of the rod outer segment (ROS), and have found that cyclic GMP acting from the inner side of the membrane markedly increases the cationic conductance of such patches (EC50 30 µM cyclic GMP) in a reversible manner, while Ca2+ is ineffective. The cyclic GMP-induced conductance increase occurs in the absence of nucleoside triphosphates and, hence, is not mediated by protein phosphorylation, but seems rather to result from a direct action of cyclic GMP on the membrane. The effect of cyclic GMP is highly specific; cyclic AMP and 2′, 3′-cyclic GMP are completely ineffective when applied in millimolar concentrations. We were unable to recognize discrete current steps that might represent single-channel openings and closings modulated by cyclic GMP. Analysis of membrane current noise shows the elementary event to be 3 f A with 110 mM Na+ on both sides of the membrane at a membrane potential of −30 mV. If the initial event is assumed to be the closure of a single cyclic GMP-sensitive channel, this value corresponds to a single-channel conductance of 100 fS. It seems probable that the cyclic GMP-sensitive conductance is responsible for the generation of the rod photoresponse in vivo.
1,122 citations
TL;DR: In this article, a discrete version of the Polyakov string is studied by analytical and numerical methods, where the role of the intrinsic metric is played by random triangulation and the critical exponents for the solvable cases D = 0 and D = −2 are shown to be larger than those calculated perturbatively.
590 citations
TL;DR: In this article, a new climatic-time series for the past 150 kyr was obtained using δ18 O data from an Antarctic ice core, which was used to reconstruct the last interglacial, the last glacial and the present holocene interglastic.
Abstract: During much of the Quaternary, the Earth's climate has undergone drastic changes most notably successive glacial and interglacial episodes. The past 150 kyr includes such a climatic cycle: the last interglacial, the last glacial and the present holocene interglacial. A new climatic–time series for this period has been obtained using δ18 O data from an Antarctic ice core.
569 citations
TL;DR: In this article, the authors consider l'instabilite gravitationnelle d'un etat spatialement uniforme de un champ scalaire relativiste sur un fond independant du temps.
Abstract: On considere l'instabilite gravitationnelle d'un etat spatialement uniforme d'un champ scalaire relativiste sur un fond independant du temps. On demontre que l'instabilite est semblable a l'instabilite de Jeans pour la matiere non relativiste du type poussiere. Les effets «hydrodynamiques» peuvent modifier considerablement le caractere de l'instabilite. Application au calcul de la probabilite de formation de trous noirs originels
456 citations
TL;DR: In this article, a critical comparison and synthesis of data from the four Pioneer Venus Probes, the Pioneer Venus Orbiter, and the Venera 10, 12, and 13 landers is derived.
417 citations
01 Dec 1985
TL;DR: For small mixing angles in vacuum the enhancement displays a resonance behavior in the neutrino energies or the density of the medium as discussed by the authors, which leads to a strong suppression of neutrinos flux even for small sin/sup 2/ 2theta.
Abstract: Matter can enhance neutrino oscillations (increase the mixing parameter sin/sup 2/ 2theta/sub m/). For small mixing angles in vacuum the enhancement displays a resonance behavior in the neutrino energies or the density of the medium. This resonance effect is important for solar neutrinos in a wide range of oscillation parameters ..delta..m/sup 2/ = 10/sup -4/--10/sup -8/ eV/sup 2/ and sin/sup 2/ 2theta>10/sup -4/. It leads to a strong suppression of the neutrino flux even for small sin/sup 2/ 2theta.
366 citations
TL;DR: In this article, it is shown that the most rational method for determining the mesopore specific surface area necessary for correcting the isotherm is the Dubinin-Kadlec γ F method identical to the t F method.
320 citations
TL;DR: Analysis of nuclear Overhauser effects, spin‐spin couplings and solvent accessibility of NH groups show that the conformation of the Na+ complex of gramicidin A in detergent micelles is an N‐terminal to N‐ terminal (head‐to‐head) dimer formed by two right‐handed, single‐stranded β6.3 helices, differing from Urry's structure by handedness of the helices.
290 citations
TL;DR: In this article, the theoretical analysis of unstationary holographic recording in photorefractive crystals under an external alternating electric field is presented, and the experimental curves for the gain factor Γ obtained in Bi12TiO20 (λ = 0.63μm) under an ac step-like field illustrate the field and spatial frequency dependencies of the hologram amplitude characteristics.
283 citations
TL;DR: In this paper, it was shown that when glucose is brought into contact with a platinum electrode, the catalytic decomposition of glucose molecules occurs in addition to the formation of strongly chemisorbed particles.
TL;DR: In this article, a geodynamic model for the Aldan shield is discussed in terms of Archaean island arc development and the most important assemblages from different units of the shield have been studied using the electron microprobe in order to unravel the metamorphic evolution of the granulites and to deduce the thermodynamic regime of this evolution.
Abstract: Precambrian granulites of the Aldan shield in southern Yakutia, USSR, form a massif of 200,000 km2 bounded by younger fold-belts to the south, west and east. The massif consists of several blocks that reflect a primary heterogeneity of composition and differences in structural and thermodynamic evolution of different parts of the area. According to structural and petrological data the massif can be divided into two megablocks: eastern Aldan and western Aldan. They are separated by a narrow meridional fold-belt. Structural evolution of this central zone was determined by the geodynamics of the mega-blocks and was completed in the late Archaean. Towards the south, this central zone is ‘transformed’into the relatively small Sutam block adjoining the Stanovoy fold-belt that bounds the Aldan shield on the south. The Sutam block is separated from the other structural units of the Aldan shield by a system of north trending grabens filled by post-Archaean sediments.
The Aldan shield is composed of Archaean high-grade granulites, while the Stanovoy fold-belt, to the south, consists of highly foliated Proterozoic rocks metamorphosed under relatively lower-grade conditions. However, relics of the granulites are mapped within the fold-belt. They contain high-grade assemblages (e.g. Opx + Sil + Qz, Sap + Qz, Opx + Gr + Sil, etc.). One of the relics, the Tokskii block, which is only slightly touched by diaphthoresis, is located in the southeastern part of the Stanovoy fold-belt. Metamorphic conditions of the Tokskii block are compared with those of the Sutam block and a similar evolution of the units is revealed.
Mineral assemblages and mineral compositions do not vary within each unit, but they change in a north-south direction. The Opx + Sil + Qz assemblage has been found only in Sutam and Tok, but not in eastern Aldan and western Aldan. The Sap + Qz assemblage has been found in the Tokskii block but has not yet been found in the Sutam block. The pyrope content in garnets, from metapelites of both blocks, is significantly higher than that from the Aldan (eastern and western blocks) rocks to the north. The most important assemblages from different units of the Aldan shield have been studied using the electron microprobe in order to unravel the metamorphic evolution of the granulites and thus to deduce the thermodynamic regime of this evolution. A geodynamic model for the Aldan shield is discussed in terms of Archaean island arc development.
01 Feb 1985
TL;DR: In this article, the parameters of an exponential isotherm of the structural component of disjoining pressure for liquid interlayers and films are found on the quartz surface, using Frumkin-Derjaguin's equation and theoretical isotherms, II( h ), as the basis, the values of contact angles are calculated.
Abstract: On the basis of an analysis of the experimental and theoretical data, the parameters of an exponential isotherm of the structural component of disjoining pressure for liquid interlayers and films are found. Inclusion of the isotherm of structural forces, II s ( h ), in the DLVO theory and the heterocoagulation theory permitted to explain the phenomena of stability and the reversible coagulation of the hydrophilic sols of silica, as well as to plot the isotherm of disjoining pressure of the wetting aqueous films on the quartz surface, II( h ). Using Frumkin-Derjaguin's equation and theoretical isotherms, II( h ), as the basis, the values of contact angles are calculated. The methods for controlling the wetting, which is due to a change in the contribution of different components of long-range surface forces to the II( h ) isotherm of wetting films, are considered.
TL;DR: In this article, the authors show the existence of Hamiltonian structures for a number of plasma situations and show the connection between decay and modulational instability growth rates and matrix elements.
TL;DR: In this paper, the authors derived a nonlinear two-wave equation for long waves on the surface of vertical falling liquid films, valid within a range of moderate Reynolds numbers and reduced in some cases to other well-known equations.
Abstract: The method of integral relations is used to derive a nonlinear two-wave equation for long waves on the surface of vertical falling liquid films. This equation is valid within a range of moderate Reynolds numbers and and be reduced in some cases to other well-known equations.
The theoretical results for the fastest growing waves are compared with the experimental results concerning velocities, wave numbers, and growth rates of the waves in the inception region. The validity of the theoretical assumptions is also confirmed by direct measurements of instantaneous velocity profiles in a wave liquid film.
The results of the experimental investigation concerning nonlinear stationary waves and the evolution of initial solitary disturbances are presented.
TL;DR: In this article, the acid form of bovine α-lactalbumin can be transformed into a similar state by thermal denaturation, which is thermodynamically two state (i.e., all-or-none transition).
Abstract: We describe a novel physical state of a protein molecule which is nearly as compact as the native state and has pronounced secondary structure, but differs from the native state by the large increase of thermal fluctuations (in particular, by the large mobility of side groups). This state has been characterized in detail for the acid form of bovine α-lactalbumin as a result of the study of physical properties of this state by a large variety of different methods (hydrodynamics, diffuse X-ray scattering, circular dichroism and infrared spectra, polarization of the luminescence, proton magnetic resonance, deuterium exchange and microcalorimetry). It has been shown that bovine α-lactalbumin can be transformed into a similar state by thermal denaturation. This process is thermodynamically two state (i.e. all-or-none transition), which means that this state differs from the native one by a phase transition of the first order.
TL;DR: In this paper, the dielectric permeability of superlattices has been calculated with regard to effects of spatial dispersion and the two-dimensional nature of excitons.
TL;DR: In this article, the existence of a local correspondence between parton and hadron distributions in hard processes (local parton-hadron duality) is discussed and a comparison is made to check up local duality at modern energies.
Abstract: A possible existence of the local correspondence between parton and hadron distributions in hard processes (local parton-hadron duality) is discussed. First comparison is made to check up local duality at modern energies. It is shown, in particular, that an account of essential single-logarithmic corrections to leading double-logarithmic approximation proves sufficient to fit π± spectra ine+e− annihilation atW≳20GeV by theoretical perturbative spectra of QCD partons. Rapidity spectra versus the normalized rapidity appear to be similar for π,K, p. Further tests of local duality as well as effects of chromodynamical coherence are suggested.
TL;DR: In this article, a comparative study has been made of glucose electrooxidation on electrodes made of metals of group VIII, Ag, Au, Cu and glassy carbon as well as of phthalocyanines and porphyrins of cobalt, manganese and iron.
TL;DR: In this article, a theoretical model of the monolayer fusion is suggested to explain the results, assuming that the structural reorganization underlying the process involves the formation of a stalk between bilayers as a result of local bending of the interacting monolayers.
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01 Jan 1985TL;DR: In this article, it has been proved that under certain conditions, strictly deterministic equations of motion generate chaos, and it has also been shown that the particles (atoms and molecules) which form the bodies surrounding us do move chaotically (randomly), in an unpredictable way.
Abstract: It had been assumed since Laplace’s time that the behavior of any mechanical system is strictly determined once we know its past (the initial conditions), we can always, having solved the equations of motion, predict its future (i.e. calculate the trajectories of particles and indicate exactly where each particle will be at any subsequent moment of time). On the other hand, our entire experience suggests that the particles (atoms and molecules) which form the bodies surrounding us do move chaotically (randomly), that is, in an unpredictable way. This contradiction is of principal importance for statistical mechanics. In fact, it raises a crucial question: is it possible at all to construct the theory on the basis of equations of the classical mechanics? Jumping ahead, I will say that yes, it is possible, since it has been proved that under certain conditions, strictly deterministic equations of motion generate chaos. This statement is one of the most important achievements of scientific thought in the second half of the twentieth century. True, it has not been crowned with a Nobel prize, but only because the discovery was made by mathematicians, and we know that mathematicians are not given Nobel prizes.
15 Oct 1985-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, an electrostatic integral spectrometer with adiabatic collimation was used to measure the tritium beta spectrum in order to determine the electron antineutrino rest mass.
Abstract: A method is proposed for measuring the tritium beta spectrum in order to determine the electron antineutrino rest mass. This method includes an electrostatic integral spectrometer with adiabatic collimation. The use of a source in the form of atomic polarized tritium in a strong magnetic field or of a gaseous molecular source is considered.
TL;DR: In this article, a method for dielectric measurements in the sub-millimeter range based on the application of a backward-wave-oscillator technique is described and applied to solving real problems of solid-state physics.
TL;DR: In this paper, the authors provided models of the Venus neutral upper atmosphere, based on both in-situ and remote sensing measurements, for the height interval from 100 to 3,500 km.
TL;DR: The ordering of intra‐ and intermolecular hydrogen bonds involving peptide CO groups in collagen and related compounds was discussed and the interpretation of the amide I multicomponent structure in collagenand isomorphous oligo‐ and polypeptides was attempted.
Abstract: The infrared amide I band of collagens (rat and cod skin) and related compounds (polyproline, polyglycine, and polytripeptides) was studied. Assignment of amide I-band components for polyproline II and polytripeptides (Gly-Pro-Pro)n and (Gly-Pro-Gly)n in the solid state and water solution was made. Three amide I components observed in the polypeptide spectra were attributed to three different peptide CO groups in each triplet. On the basis of this assignment, the interpretation of the amide I multicomponent structure in collagen and isomorphous oligo- and polypeptides was attempted. The ordering of intra- and intermolecular hydrogen bonds involving peptide CO groups in collagen and related compounds was discussed.
TL;DR: In this paper, a complex analysis of experimental results on the structure and properties of grain boundaries in different materials has been analyzed on the basis of the original works available by the present time.
TL;DR: The perturbation method for calculating atomic energies by power series in 1/Z and αZ has been extended to include parameters for screening and for expansion in the principal quantum number n as mentioned in this paper.
Abstract: The perturbation method for calculating atomic energies by power series in 1/Z and αZ has been extended to include parameters for screening and for expansion in the principal quantum number n. Numerical results are given and compared with observations for 1s nl and 1s2 nl of the helium and lithium isoelectronic sequences.
TL;DR: It is shown by thermodynamic analysis of the experimentally determined excess heat capacity function that the four calcium-binding domains in these two related proteins are not integrated into a single co-operative system, as would be the case if they formed a common hydrophobic core in the molecule, but still interact with each other in a very specific way.
TL;DR: In this article, it was shown that the EMC-effect can be explained by the nuclear structure and that the binding of nucleons played an important role in the nuclear EMC effect.
TL;DR: The substantial repertoire of laser radiation—its coherence, range of intensity and frequency, controlability of focal area and of beam length—has been comprehensively explored in the contexts of micro- and macro-diagnostics of cells, biochemical kinetics, therapy and surgery.
Abstract: The substantial repertoire of laser radiation—its coherence, range of intensity and frequency, controlability of focal area and of beam length—has been comprehensively explored in the contexts of micro- and macro-diagnostics of cells, biochemical kinetics, therapy and surgery.