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Showing papers by "Russian Academy of Sciences published in 1986"


Book
01 Jan 1986
TL;DR: In this article, the authors present examples of stable laws in applications, including analytical properties of the distributions in the family, special properties of laws in the class, and estimators of the parameters of stable distributions.
Abstract: Examples of stable laws in applications Analytic properties of the distributions in the family $\mathfrak S$ Special properties of laws in the class $\mathfrak W$ Estimators of the parameters of stable distributions.

1,707 citations


Journal ArticleDOI
TL;DR: The equilibrium control hypothesis (λ model) is considered with special reference to the length-force invariant characteristic of the muscle together with central and reflex systems subserving its activity.
Abstract: The equilibrium control hypothesis (λ model) is considered with special reference to the following concepts: (a) the length-force invariant characteristic (IC) of the muscle together with central and reflex systems subserving its activity; (b) the tonic stretch reflex threshold (λ) as an independent measure of central commands descending to alpha and gamma motoneurons; (c) the equilibrium point, defined in terms of λ, IC and static load characteristics, which is associated with the notion that posture and movement are controlled by a single mechanism; and (d) the muscle activation area (a reformulation of the “size principle”)— the area of kinematic and command variables in which a rank-ordered recruitment of motor units takes place. The model is used for the interpretation of various motor phenomena, particularly electromyographic patterns. The stretch reflex in the λ model has no mechanism to follow-up a certain muscle length prescribed by central commands. Rather, its task is to bring the system to an ...

1,287 citations


Journal ArticleDOI
TL;DR: For small mixing angles θ the amplification of ν oscillations in matter has the resonance form (resonance in neutrino energy or matter density) in the Sun resonance effect.
Abstract: For small mixing angles θ the amplification of ν oscillations in matter has the resonance form (resonance in neutrino energy or matter density). In the Sun resonance effect results in nontrivial changing (suppression) of ν-flux for a wide range of neutrino parameters Δm2=(3·10−4÷10−8) (eV)2, sin22θ>10−4.

912 citations


Journal ArticleDOI
TL;DR: This work has shown that not only the intensity of the response of the immune system to carbon dioxide but also its ability to reprogram theresponse of the nervous system to accommodate high levels of carbon dioxide.
Abstract: Note: Tagantsev, Ak Af Ioffe Engn Phys Inst,Leningrad 194021,UssrPart 2E4504Times Cited:19Cited References Count:16 Reference LC-ARTICLE-1986-010doi:10.1103/PhysRevB.34.5883 Record created on 2006-08-21, modified on 2017-11-27

583 citations


Journal ArticleDOI
TL;DR: The Ising model on a collection of all planar lattices with coordination number 4 is shown to be equivalent to the exactly solvable two-matrix model in the large N limit.

443 citations


Journal ArticleDOI
TL;DR: It is proposed that central regulation of stretch reflex thresholds governs voluntary control over muscle force and length and concluded that voluntary movements are effected by the central nervous system with the help of the mechanisms that underlie the variability and modifiability of innate motor patterns.
Abstract: The following factors underlying behavioral plasticity are discussed: (1) reflex adaptability and its role in the voluntary control of movement, (2) degrees of freedom and motor equivalence, and (3) the problem of the discrete organization of motor behavior. Our discussion concerns a variety of innate motor patterns, with emphasis on the wiping reflex in the frog.It is proposed that central regulation of stretch reflex thresholds governs voluntary control over muscle force and length. This suggestion is an integral part of the equilibrium-point hypothesis, two versions of which are compared.Kinematic analysis of the wiping reflex in the spinal frog has shown that each stimulated skin site is associated with a group of different but equally effective trajectories directed to the target site. Such phenomena reflect the principle of motor equivalence -the capacity of the neuronal structures responsible for movement to select one or another of a set of possible trajectories leading to the goal. Redundancy of degrees of freedom at the neuronal level as well as at the mechanical level of the body's joints makes motor equivalence possible. This sort of equivalence accommodates the overall flexibility of motor behavior.An integrated behavioral act or a single movement consists of dynamic components. We distinguish six components for the wiping reflex, each associated with a certain functional goal, specific body positions, and motor-equivalent movement patterns. The nervous system can combine the available components in various ways in forming integrated behavioral sequences. The significance of command neuronal organization is discussed with respect to (1) the combinatory strategy of the nervous system and (2) the relation between continuous and discrete forms of motor control. We conclude that voluntary movements are effected by the central nervous system with the help of the mechanisms that underlie the variability and modifiability of innate motor patterns.

429 citations


Journal ArticleDOI
TL;DR: The stability of the structure of sperm whale metmyoglobin has been studied in various solutions by scanning microcalorimetry, light absorption, circular dichroism, nuclear magnetic resonance spectroscopy and viscosimetry and it has been shown that in 10 mM-sodium acetate solutions the protein molecule undergoes a reversible conformational transition into a non-compact disordered state.

381 citations


Journal ArticleDOI
TL;DR: In this article, it has been shown that the form of a low-frequency boson peak in Raman scattering is universal for glasses of different chemical compositions and that from this form one can determine the structural correlation function, i.e. the character of violations of ordered arrangement of atoms within several coordination spheres in non-crystalline solids.

366 citations


Book ChapterDOI
01 Jan 1986
TL;DR: In this paper, modern interpretations of the kinetics, thermodynamics and mechanisms of curing of epoxy oligomers with primary, secondary, and tertiary amines and their mixtures, as well as the structure of the resulting polymers are discussed.
Abstract: In this review, modern interpretations of the kinetics, thermodynamics and mechanisms of curing of epoxy oligomers with primary, secondary, and tertiary amines and their mixtures, as well as the structure of the resulting polymers are discussed The effect of the structure of the reagents on their reactivity is analyzed Kinetic peculiarities of the deep stages of the curing process are emphasized Problems to be solved in the future are formulated

345 citations


Journal ArticleDOI
01 Apr 1986-Nature
TL;DR: This work shows for the first time a direct interaction between the signal sequence of a secretory protein and a component of SRP, the 54K polypeptide (relative molecular mass (Mr) 54,000), achieved by means of a new method of affinity labelling which involves the translational incorporation of an amino acid, carrying a photoreactive group, into nascentpolypeptides.
Abstract: Hydrophobic signal sequences direct the translocation of nascent secretory proteins and many membrane proteins across the membrane of the endoplasmic reticulum. Initiation of this process involves the signal recognition particle (SRP), which consists of six polypeptide chains and a 7S RNA and interacts with ribosomes carrying nascent secretory polypeptide chains. In the case of aminoterminal, cleavable signal sequences, in the absence of microsomal membranes it exerts a site-specific translational arrest in vitro. The size of the arrested fragment (60-70 amino-acid residues) suggests that elongation stops when the signal sequence has emerged fully from the ribosome. However, a direct interaction between the signal sequence and SRP has not previously been demonstrated and has even been questioned recently. We now show for the first time a direct interaction between the signal sequence of a secretory protein and a component of SRP, the 45K polypeptide (relative molecular mass (Mr) 54,000). This was achieved by means of a new method of affinity labelling which involves the translational incorporation of an amino acid, carrying a photoreactive group, into nascent polypeptides.

321 citations


Journal ArticleDOI
TL;DR: In this article, a regular procedure for constructing an infinite set of additional (spacetime variables explicitly dependent) symmetries of integrable nonlinear evolution equations (INEEs) is presented.
Abstract: We present a regular procedure for constructing an infinite set of additional (spacetime variables explicitly dependent) symmetries of integrable nonlinear evolution equations (INEEs). In our method, additional symmetry equations arise together with their L-A pairs, so that they are integrable themselves. This procedure is based on a modified ‘dressing’ method. For INEEs in 1+1 dimensions, some appropriate symmetry equations are shown to form the vector fields on a circle S1 algebra representation. In contrast to the so-called isospectral deformations, these symmetries result from conformal transformations of the associated linear problem spectrum. For INEEs in 2+1 dimensions, the commutation relations for symmetry equations are shown to coincide with operators \(\lambda ^m \partial _\lambda \), with integer m, p. Some additional results about Kac-Moody algebra applications are presented.

Journal ArticleDOI
TL;DR: It is concluded that QA, KA and L-Glu activate the same excitatory receptors with apparent Kd values of 9.3X 10(-5) M, 5.0 X 10(-4) M and 1.1 X 10−3 M, respectively.


Journal ArticleDOI
TL;DR: In this paper, the apparent polar wander curves for stable Eurasia and Africa since the Triassic were re-examined and combined with curves of North and South America according to the kinematics of the Atlantic ocean and a synthetic polar wander curve was given.

Book ChapterDOI
TL;DR: In this paper, the authors describe the formation, structure (stereochimie and stereodynamique), and donnees de spectroscopie RMN des composes du titre.
Abstract: Formation, structure (stereochimie et stereodynamique), et donnees de spectroscopie RMN des composes du titre

Journal ArticleDOI
TL;DR: A general scheme for the different types of solutions in dependence on the initial phase space domain has been obtained as for as the chaotization thresshold and a velocity-space diffusion coefficient in strongly curved fields as mentioned in this paper.

Journal ArticleDOI
TL;DR: The present analysis confirms the view that such a selection on sufficiently polymorphic traits for speciation is ecologically realistic and shows that populations with bimodal distributions of some genetically determined quantitative characters can have a considerable life-time.
Abstract: This paper is written to compare the results of theoretical investigations of sympatric speciation with the relevant experimental data. We understand sympatric speciation as a formation of species out of a population whose spatial structure is not important genetically. A necessary prerequisite for speciation is an action of disruptive selection on sufficiently polymorphic traits. The present analysis confirms the view that such a selection is ecologically realistic. The genetical part of speciation begins with a development of reproductive isolation between those individuals that are opposed in some characters. It is shown that selection for reproductive isolation may be quite strong. Extinction of intermediate individuals, which completes speciation, proceeds under a wide range of conditions, including those when the newly formed species differ in quantitative characters, though most of the genes arc likely to remain the same in both species. The whole process seems possible if differences in several (up to 10) loci are sufficient to adapt the forming species to different niches and to establish reproductive isolation. It is shown that populations with bimodal distributions of some genetically determined quantitative characters can have a considerable life-time. Such distributions may be formed either as a transition stage of sympatric speciation or represent a stationary state under conditions close to those necessary to complete speciation. They are very important for experimental investigations. Sympatric speciation always follows the same principal course; it does not contradict the idea of a genome coadaptedness. The occurrence of sympatric speciation is different for different taxa depending rather on how frequently populations are subjected to the appropriate kind of selection than on their ability to obey it.

Journal ArticleDOI
TL;DR: In this article, it was shown that using multi-scale expansions conventionally employed in the theory of nonlinear waves one can transform systems integrable by the IST method into other systems of this type.

Journal ArticleDOI
TL;DR: (Na+ + K+)‐ATPase α‐Sub Unit β‐Subunit β-Subunit cDNA nucleotide sequence Primary structure Glycopeptide Transmembrane arrangement

Journal ArticleDOI
TL;DR: It was shown that systematic addition of 5-HT in physiological concentrations to the nutrient medium during cultivation of the explants stimulates glia proliferation, neuron differentiation, neuropil formation, axon myelination and synaptogenesis, and the effects of serotonin (5-HT) on these processes were studied.

Journal ArticleDOI
TL;DR: For homopurine-homopyrimidine tracts in superhelical DNA, a structure involving Watson-Crick and Hoogsteen paired triple helixes, hairpin loops and unstructured domains is proposed, consistent with available S1 cleavage, pH and alkylation data and energetics undersuperhelical stress.
Abstract: For homopurine-homopyrimidine tracts in superhelical DNA, we propose a structure involving Watson-Crick and Hoogsteen paired triple helixes, hairpin loops and unstructured domains. Topologically, the whole structure is equivalent to an open region. The proposed structure is consistent with available S1 cleavage, pH and alkylation data and energetics under superhelical stress; this new structure is a much more probable candidate than the one proposed by us recently (V.I. Lyamichev, S.M. Mirkin & M.D. Frank-Kamenetskii, J. Biomole. Str. Dyns 3, 327-338, 1985).

Journal ArticleDOI
TL;DR: In this paper, the Vlasov kinetic approach is used to study the stability of magnetopause magnetic surfaces that can be destructed by the growth and overlapping of magnetic islands.
Abstract: This review is devoted to the problem of the internal fine structure of the Earth's magnetopause. A number of theoretical and experimental papers dealing with this subject is discussed from a unified viewpoint. The Vlasov kinetic approach is used to study the stability of magnetopause magnetic surfaces that can be destructed by the growth and overlapping of magnetic islands. The stochastic wandering of magnetic field lines between the destructed surfaces can result in magnetic percolation, i.e. the appearance of a topological connection of interplanetary and geomagnetic field lines. Such a process may be considered as a mechanism of the macroscopic (but spatially localized) reconnection. We discuss this in relation with the phenomena of spontaneous ‘patchy’ reconnection, recently observed at ISEE satellites and now known as flux transfer events. Drift tearing mode, which is responsible for the growth of magnetic islands can be stabilized due to its coupling with ion sound waves, and the process of percolation will be interrupted if even a thin region with smooth stable magnetic surfaces exists within the magnetopause. Accordingly, we obtain a magnetopause stability threshold for localized reconnection. It is represented in the form of dependence of marginal dimensionless thickness of the magnetopause on the angle of magnetic field rotation within it. Further, we discuss the possible role of lower hybrid turbulence permanently observed within the. magnetopause and speeding up the process of reconnection. Nonlinear calculations supporting the developed model are given in the appendices. We consider briefly the motion of reconnecting flux tubes and evaluate the time necessary for the accomplishment of percolation. The calculations show that the appearance of reconnection ‘patchies’ at the dayside magnetopause cannot occur too far from the stagnation region. The latter agrees with experimental indications on the most probable site of the formation of flux transfer events. In the concluding part of the review we discuss the necessary limitations on the theory, possible lines of its future advance and comparison with the experimental data.

Journal ArticleDOI
TL;DR: In this article, a series of laboratory experiments were conducted to study convective structures in rotating fluids (distilled water) in ranges of Rayleigh flux number Raf from 106 to 2 × 1011 and of Taylor number Ta from 106-1012.
Abstract: We describe a series of laboratory experiments to study convective structures in rotating fluids (distilled water) in ranges of Rayleigh flux number Raf from 106 to 2 × 1011 and of Taylor number Ta from 106 to 1012. An intermediate quasi-stationary ring pattern of convection was found to arise from the interaction of the onset of convection with the fluid spin-up, for which we determined the times of origin and destruction, the distances between the rings, and the diameter of the central ring in terms of Raf and Ta. The ring structure evolves into a vortex grid which can be regular or irregular. In terms of Raf and Ta the regular grid exists in the linear regime, when the number of vortices N is in accord with the linear theory, when , or in the nonlinear regime when N ∝ h−2Ta½Raf−⅙ ∝ where Ω is the angular velocity and h is the fluid depth. In the irregular regime we always have N ∝ Ω. The transition from the regular regime to the irregular one is rather gradual and is determined by the value of the ordinary Rayleigh number, which we found to be greater than the first critical number Ra ∝ Ta2/3 by a factor about 25–40. In the transition region vortex interactions are observed, which start with rotation of two adjacent vortices around a common axis, then the vortices come closer and rotation accelerates, following which the vortices form a double helix and then coalesce into one stronger vortex.Some other qualitative experiments show that if the rotating vessel with the convective fluid is inclined to the horizontal, the vortex grid is formed along the rotation axis in accordance with the Proudman–Taylor theorem.

Book ChapterDOI
01 Jan 1986
TL;DR: In this article, the authors proposed a method for determining the functional type distribution (FTD) of telechelic polymers based on the regularities of the adsorption of macromolecules.
Abstract: Telechelic polymers are widely used to obtain various types of polymers. Of exceptional importance in the behaviour of Telechelic polymers is the nature and number of reactive functional groups (RFG). Along with molecular weight distribution (MWD), a telechelic polymer is to be characterized by a new quantity, introduced by us, — the functionality type distribution (FTD). This characteristic determines to a considerable extent the topology of the resulting polymer. The determination of FTD is, however, very complicated. A unique method developed by us — chromatography of macromolecules at “critical conditions” close to the coil-adsorbed coil transition point — solves this problem for telechelic polymers. The basis of the method derived from the regularities of the adsorption of macromolecules is discussed and examples of separation of a number of hydroxyl-containing telechelic polymers with respect to the functionality types are given. Further development of the method for the analysis of other types of macromolecular heterogeneity is briefly discussed (the separation of cyclic and linear macromolecules is taken as an example).

Journal ArticleDOI
TL;DR: In this paper, the authors generalized the sum rules method to the case of finite temperatures and densities and formulated conditions under which this method is quite efficient for the determination of the spectrum of hadronic matter at T ≠ 0.

Journal ArticleDOI
TL;DR: For mantle peridotite xenoliths from the Tariat Depression in central Mongolia, an origin as partial melt residues has been inferred from the systematic change of bulk chemical compositions with mineral chemistries and modal compositions as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, a charge transport in amorphous silicon (aSi) doped with ion implantation of Mn+, Ni+, Fe+, and Cu+ ions is studied using ESR technique, temperature dependence of conductivity σ(T), and thermopower α(T) measurements with increasing of impurity (Mn, Ni, Fe, Fe) concentration (from 1018to 1019 cm−3), the localized state density and σ decrease owing to the passivation of silicon dangling bonds with impurity atoms.
Abstract: Charge transport in amorphous silicon (aSi) doped with ion implantation of Mn+, Ni+, Fe+, and Cu+ ions is studied using ESR technique, temperature dependence of conductivity σ(T), and thermopower α(T) measurements With increasing of impurity (Mn, Ni, Fe) concentration (from 1018to 1019 cm−3) the localized state density and σ decrease owing to the passivation of silicon dangling bonds with impurity atoms An analysis of conductivity and thermopower data allows to reveal three temperature regions 1) At 250 500 K electron transport dominates 3) At T < 250 K hopping conductivity with variable range hopping near Fermi level prevails For a-Si:Mn in the region of 4 < T < 80 K Coulomb correlations are detected in the behaviour of σ(T) The Coulomb gap is foundto reach a maximum value 25 meV which appears to be one order of value larger than the known (one) in semiconductors doped with shallow impurity levels [Russian Text Ignored]

Journal ArticleDOI
TL;DR: The α‐subunit primary structure of cyclic GMP phosphodiesterase has been determined by parallel analysis of the protein amino acid sequence and the corresponding cDNA nucleotide sequence.

Book ChapterDOI
01 Jan 1986
TL;DR: In this paper, the properties of network polymers, obtained from mixtures with different reactant ratios and at different curing temperatures (Tcure), have been chemically characterized (curing conversion, concentration of chemical crosslinks) at all stages of the cure process.
Abstract: Properties of networks, prepared by curing of diglycidyl ethers of bisphenols with some aromatic amines, have been considered. Network polymers, obtained from mixtures with different reactant ratios and at different curing temperatures (Tcure), have been chemically characterized (curing conversion, concentration of chemical crosslinks) in detail at all stages of the cure process. Polymer properties, i. e. mechanical features such as rigidity and deformability and thermal features such as Tg, heat capacity, and coefficient of thermal expansion, have been analyzed and interpreted in terms of chemical and physical (packing density) structure. Plastic deformation and some fracture peculiarities of network glasses have been examined. In a few cases, the properties of these polymers in the rubbery state have been considered. A comparison of the structure and properties of network and linear polymeric glasses has been made. It has been shown that, in the formation of the structure and properties of these polymers, an important role is played by vitrification during cure. Polymers prepared at low Tcure usually show higher mechanical properties which, however, are not due to the high density of their glassy state. The peculiarities of the mechanical behaviour and vitrification of polymers isothermally cured at different Tcure have been considered.

Journal ArticleDOI
TL;DR: Genome degradation in dying thymocytes of irradiated or hydrocortisone‐treated rats is accounted for by internucleosomal DNA fragmentation and postirradiation DNA cleavage in the 3 investigated cell cultures is disorderly and is probably caused by the activation of hydrolases in dead cells.