Showing papers by "Russian Academy of Sciences published in 1991"
TL;DR: Binding of the hydrophobia fluorescent probe, 1‐anilino‐naphthalene‐8‐sulfonate (ANS), to synthetic polypeptides and proteins with a different structural organization has been studied and it has been shown that ANS has a much stronger affinity to the protein “molten globule” state.
Abstract: Binding of the hydrophobic fluorescent probe, 1-anilino-naphthalene-8-sulfonate (ANS), to synthetic polypeptides and proteins with a different structural organization has been studied. It has been shown that ANS has a much stronger affinity to the protein "molten globule" state, with a pronounced secondary structure and compactness, but without a tightly packed tertiary structure as compared with its affinity to the native and coil-like proteins, or to coil-like, alpha-helical, or beta-structural hydrophilic homopolypeptides. The possibility of using ANS for the study of equilibrium and kinetic molten globule intermediates is demonstrated, with carbonic anhydrase, beta-lactamase, and alpha-lactalbumin as examples.
1,193 citations
Book•
01 Oct 1991TL;DR: In this article, the orthogonality relation (2.0.1) is reduced to 2.0, where w(x) is a function of jumps, i.e. the piecewise constant function with jumps ϱ i at the points x = x i.
Abstract: The basic properties of the polynomials p n (x) that satisfy the orthogonality relations
$$ \int_a^b {{p_n}(x)} {p_m}(x)\rho (x)dx = 0\quad (m
e n) $$
(2.0.1)
hold also for the polynomials that satisfy the orthogonality relations of a more general form, which can be expressed in terms of Stielties integrals
$$ \int_a^b {{p_n}(x)} {p_m}(x)dw(x) = 0\quad (m
e n), $$
(2.0.2)
where w(x) is a monotonic nondecreasing function (usually called the distribution function). The orthogonality relation (2.0.2) is reduced to (2.0.1) in the case when the function w(x) has a derivative on (a, b) and w′(x) = ϱ(x). For solving many problems orthogonal polynomials are used that satisfy the orthogonality relations (2.0.2) in the case when w(x) is a function of jumps, i.e. the piecewise constant function with jumps ϱ i at the points x = x i . In this case the orthogonality relation (2.0.2) can be rewritten in the form
$$ \sum\limits_i {{p_n}({x_i})pm} ({x_i}){\rho_i} = 0\quad (m
e n). $$
(2.0.3)
1,032 citations
01 Jan 1991
TL;DR: X is the vector space which acts in the n-dimensional (complex) vector space R.1.1 and is related to Varepsilon by the following inequality.
Abstract: $$X = {X_0} + \varepsilon {X_1} + {\varepsilon ^2}{X_2} + \cdots $$
(1.1.1)
which acts in the n-dimensional (complex) vector space R.
971 citations
TL;DR: Phylogenetic analysis using three independent methods of three construction confirmed the separation of the positive-strand RNA viral polymerases into three supergroups and revealed some unexpected clusters within the supergroups.
Abstract: Representative amino acid sequences of the RNA-dependent RNA polymerases of all groups of positive-strand RNA viruses were aligned hierarchically, starting with the most closely related ones. This resulted in delineation of three large supergroups. Within each of the supergroups, the sequences of segments of approximately 300 amino acid residues originating from the central and/or C-terminal portions of the polymerases could be aligned with statistically significant scores. Specific consensus patterns of conserved amino acid residues were derived for each of the supergroups. The composition of the polymerase supergroups was as follows. I. Picorna-, noda-, como-, nepo-, poty-, bymo-, sobemoviruses, and a subset of luteoviruses (beet western yellows virus and potato leafroll virus). II. Carmo-, tombus-, dianthoviruses, another subset of luteoviruses (barley yellow dwarf virus), pestiviruses, hepatitis C virus (HCV), flaviviruses and, unexpectedly, single-stranded RNA bacteriophages. III. Tobamo-, tobra-, hordei-, tricornaviruses, beet yellows virus, alpha-, rubi-, furoviruses, hepatitis E virus (HEV), potex-, carla-, tymoviruses, and apple chlorotic leaf spot virus. An unusual organization was shown for corona- and torovirus polymerases whose N-terminal regions were found to be related to the respective domains of supergroup I, and the C-terminal regions to those of the supergroup III polymerases. The alignments of the three polymerase supergroups were superimposed to produce a comprehensive final alignment encompassing eight distinct conserved motifs. Phylogenetic analysis using three independent methods of tree construction confirmed the separation of the positive-strand RNA viral polymerases into three supergroups and revealed some unexpected clusters within the supergroups. These included the grouping of HCV and the pestiviruses with carmoviruses and related plant viruses in supergroup II, and the grouping of HEV and rubiviruses with furoviruses in supergroup III.
895 citations
TL;DR: In this article, the failure process in a brittle granite sample can be stabilized by controlling axial stress to maintain a constant rate of acoustic emission, and the post-failure stress curve can be followed quasi-statically, extending to hours the fault growth process.
Abstract: The failure process in a brittle granite sample can be stabilized by controlling axial stress to maintain a constant rate of acoustic emission. As a result, the post-failure stress curve can be followed quasi-statically, extending to hours the fault growth process which normally would occur violently in a fraction of a second. Using a procedure originally developed to locate earthquakes, acoustic emission arrival-time data are inverted to obtain three-dimensional locations of microseisms. These locations provide a detailed view of fracture nucleation and growth.
870 citations
TL;DR: A physical mechanism and proposed theory permits a quantitative explanation for the main characteristics of experimentally observed effects of weak magnetic fields with biological systems.
Abstract: A physical mechanism is suggested for a resonant interaction of weak magnetic fields with biological systems. An ion inside a Ca(2+)-binding protein is approximated by a charged oscillator. A shift in the probability of ion transition between different vibrational energy levels occurs when a combination of static and alternating magnetic fields is applied. This in turn affects the interaction of the ion with the surrounding ligands. The effect reaches its maximum when the frequency of the alternating field is equal to the cyclotron frequency of this ion or to some of its harmonics or sub-harmonics. A resonant response of the biosystem to the magnetic field results. The proposed theory permits a quantitative explanation for the main characteristics of experimentally observed effects.
553 citations
01 Jan 1991
TL;DR: In this article, an uncertainty relation between energy and time having a simple physical meaning is rigorously deduced from the principles of quantum mechanics, and some examples of its application are discussed, as well as its application in computer vision.
Abstract: An uncertainty relation between energy and time having a simple physical meaning is rigorously deduced from the principles of quantum mechanics. Some examples of its application are discussed.
493 citations
TL;DR: The weather generator developed by the authors contains a stochastic weather model based on a new approach to weather data analysis and also a computer program package that carries out the tuning of the model on real time series and generates the random weather processes.
484 citations
TL;DR: In this article, the authors presented the results of the total analytical reevaluation of the massless next-next-to-leading αs3 QCD correction to R(s) = σtot(e+e−→γ→hadrons)/σ(e−e −→μ+μ−).
464 citations
TL;DR: In vivo electroporation can be used for the introduction of plasmid DNA into skin cells of mouse and NEO-resistant colonies were found in primary cell cultures obtained from the treated skin.
432 citations
TL;DR: Submissive males after 20 defeats demonstrated passive defense postures instead of active defense and withdrawal which they had displayed in first encounters, and new immobile postures appeared, which were very rare in the first confrontations.
Abstract: Long experience of defeat in daily social intermale confrontations and permanent living with aggressive males under sensory contact conditions [Kudryavtseva (8)] has been shown to produce changes in the patterns of submissive behavior of male mice of C57BL/6J strain. The submissive males after 20 defeats demonstrated passive defense postures instead of active defense and withdrawal which they had displayed in first encounters. Moreover, new immobile postures appeared, which were very rare in the first confrontations. Submissive animals displayed a decrease of ambulation in the open-field test and increase the immobility time in the Porsolt's test. Chronic treatment with imipramine prevented the increase of “depressiveness” estimated by means of the Porsolt's test. There was a loss of weight and some disturbances in gastrointestinal functions. The data are discussed in terms of the development of depression in submissive male C57BL/6J mice as a result of chronic unavoidable social stress.
TL;DR: This study completes the sequence of the MHV genome, which is 31 kb long, and constitutes the largest viral RNA known.
TL;DR: In this paper, a mean-field analytical theory describing the conformational transition related to the collapse of the layers of polymer chains grafted onto the impermeable surfaces of different morphologies (a planar surface, a sphere, and a cylinder) has been developed.
Abstract: The mean-field analytical theory describing the conformational transition related to the collapse of the layers of polymer chains grafted onto the impermeable surfaces of different morphologies (a planar surface, a sphere, and a cylinder) has been developed. The dependence of the character of this transition on the type of the surface morphology is analyzed. Analytical expressions describing the distribution of monomer units density and chain ends along the layer height at arbitrary solvent strength are obtained
TL;DR: In this paper, the analytical expressions for the probability of tunnel ionization of atoms and atomic ions and for the energy and angular electron spectra in a strong low-frequency electromagnetic field are obtained.
Abstract: The analytic expressions for the probabilities of tunnel ionization of atoms and atomic ions and for the energy and angular electron spectra in a strong low-frequency electromagnetic field are obtained. The adiabatic approximation of quantum mechanics is used. The cases of linear and circular polarization of the field are considered.
TL;DR: It was noted that papain‐like proteases of positive‐stranded RNA viruses are much more variable both in their sequences and in genomic locations than chymotrypsin‐related proteases found in the same virus class.
TL;DR: In this paper, the authors report that, as a result of these policy initiatives, lead concentrations in Greenland snow have decreased by a factor of 7.5 over the past twenty years.
Abstract: MORE than twenty years ago, Patterson and co-workers1 showed that evidence of lead concentrations in Greenland ice and snow had increased about 200-fold since ancient times. From their results, they concluded that more than 99% of this highly toxic metal in the global troposphere of the Northern Hemisphere originated from human activities in the mid 1960s—mainly from the use of alkyl-leaded petrol. At least in part because of this evidence, the United States and other countries limited the use of lead additives in petrol from about 1970. Here we report that, as a result of these policy initiatives, lead concentrations in Greenland snow have decreased by a factor of 7.5 over the past twenty years. We also show that over the same time period, cadmium and zinc concentrations have decreased by a factor of 2.5.
TL;DR: In this paper, the Markov lattice: local construction and global construction are used to estimate the decay of correlations in deterministic systems, and the central limit theorem is proved.
Abstract: CONTENTS ??1. Introduction ??2. Billiards: necessary information ??3. The Markov lattice: local construction ??4. The Markov lattice: global construction ??5. An estimate for the decay of correlations ??6. The central limit theorem ??7. Applications. Diffusion in deterministic systems Appendix 1 Appendix 2 Appendix 3 References
TL;DR: It is shown that binding of the ssb mRNA to 30S ribosomes is S1-dependent and the oligo(U)-sequence preceding the SD domain was found to be the target for S1.
Abstract: Ribosomal protein S1 is known to play an important role in translational initiation, being directly involved in recognition and binding of mRNAs by 30S ribosomal particles. Using a specially developed procedure based on efficient crosslinking of S1 to mRNA induced by UV irradiation, we have identified S1 binding sites on several phage RNAs in preinitiation complexes. Targets for S1 on Q beta and fr RNAs are localized upstream from the coat protein gene and contain oligo(U)-sequences. In the case of Q beta RNA, this S1 binding site overlaps the S-site for Q beta replicase and the site for S1 binding within a binary complex. It is reasonable that similar U-rich sequences represent S1 binding sites on bacterial mRNAs. To test this idea we have used E. coli ssb mRNA prepared in vitro with the T7 promoter/RNA polymerase system. By the methods of toeprinting, enzymatic footprinting, and UV crosslinking we have shown that binding of the ssb mRNA to 30S ribosomes is S1-dependent. The oligo(U)-sequence preceding the SD domain was found to be the target for S1. We propose that S1 binding sites, represented by pyrimidine-rich sequences upstream from the SD region, serve as determinants involved in recognition of mRNA by the ribosome.
TL;DR: The existence of a phase transition within the vortex-lattice state is demonstrated: the superconducting coherence between distant layers vanishes at a temperature which is substantially lower than the melting temperature.
Abstract: We study thermal fluctuations in a layered superconductor in the presence of a magnetic field applied orthogonal to the layers. A phase diagram for this case is proposed. In the weak-field region, fluctuations of a vortex lattice are of three-dimensional (3D) nature. This leads to a two-stage melting: When the temperature is raised, a phase transition to the vortex-line liquid occurs, then independent liquid systems of 2D vortices in different layers are formed. For fields larger than the crossover value, both fluctuations and melting of the vortex lattice become of 2D type. We study the effect of vortex-lattice fluctuations on the long-range superconducting order. We demonstrate the existence of a phase transition within the vortex-lattice state: The superconducting coherence between distant layers vanishes at a temperature which is substantially lower than the melting temperature.
TL;DR: It is reported that the α-latrotoxin receptor specifically binds to a synaptic vesicle protein, synaptotagmin, and modulates its phosphorylation, suggesting that a physiological role of this toxin may be the docking ofaptic vesicles at the active zone.
Abstract: A VERTEBRATE neurotoxin, α-latrotoxin, from black widow spider venom causes synaptic vesicle exocytosis and neurotransmitter release from presynaptic nerve terminals11–4. Although the mechanism of action of α-latrotoxin is not known, it does require binding of α-latrotoxin to a high-affinity receptor on the presynaptic plasma membrane5. The α-latrotoxin receptor seems to be exclusively at the presynaptic plasmamembrane6. Here we report that the α-latrotoxin receptor specifically binds to a synaptic vesicle protein, synaptotagmin, and modulates its phosphorylation. Synaptotagmin is a synaptic vesicle-specific membrane protein that binds negatively charged phospholipids and contains two copies of a putative Ca2+-binding domain from protein kinase C (the C2-domain), suggesting a regulatory role in synaptic vesicle fusion7,8. Our findings suggest that a physiological role of the α-latrotoxin receptor may be the docking of synaptic vesicles at the active zone. The direct interaction of the α-latrotoxin receptor with a synaptic vesicle protein also suggests a mechanism of action for this toxin in causing neurotransmitter release.
TL;DR: In this paper, an analytical treatment of the problem of pattern selection in a fully non-local symmetrical model of dendritic crystal growth is presented, based on the assumption that anisotropies of surface energy and kinetic effects are small.
Abstract: We present an analytical treatment of the problem of pattern selection in a fully non-local symmetrical model of dendritic crystal growth. Simplifications of mathematical equations are based on the assumption that anisotropies of surface energy and kinetic effects are small. Selection rules for growth velocity and instability increments are derived at arbitrary Peclet numbers. For a dendrite growing in a channel, a double-valued velocity versus undercooling dependence is obtained. The upper branch of the solution is stable and changes into a free dendrite with increased channel width. Interplay between surface energy and kinetic effects results in morphological transition from surface energy dendrite to dense branching morphology and then to kinetic dendrite. In the framework of the boundary-layer model it is shown that at deep undercooling parabolic dendrite turns into angular dendrite and then into planar front.
TL;DR: A model that accounts for all proteolytic processing events in the potyviral polyprotein is presented and suggests that the 35-kDa protein functions as a proteinase to cleave at its C-terminus.
TL;DR: It was concluded that the capsid proteins of all rod-shaped viruses, on the one hand, and filamentous viruses,on the other hand, evolved from common ancestors.
TL;DR: In this article, the authors present the results of a full analytic reevaluation of all diagrams in the O(n)-symmetric φ4theory in D = 4-ϵ dimensions.
TL;DR: It is reported that injection of the anti-kinesin antibody into human fibroblasts results in the redistribution of intermediate filaments to a tight perinuclear aggregate but had no effect on the distribution of microtubules, indicating that kinesin is involved not only in organelle movement but also in interaction of the two major cytoskeletal systems, intermediate Filaments and micro Tubules.
Abstract: INTERMEDIATE filaments in most types of cultured cells coalign with microtubules. Depolymerization of microtubules results in collapse of vimentin and desmin intermediate filaments to the nucleus where they form a perinuclear cap (reviewed in ref. 1). Collapse can also be induced by microinjection of antibodies against intermediate filament or microtubule proteins2–7. Thus, two filament systems interact with each other. But the molecules mediating this interaction are unknown. One of the candidates for this role is a microtubule motor kinesin8. Recent data showed that kinesin is involved in the plus end-directed movement of the membranous organelles along microtubules such as radial extension of lysosomes in macrophages9 and centrifugal movement of pigment in melanophores10. Here we report that injection of the anti-kinesin antibody into human fibroblasts results in the redistribution of intermediate filaments to a tight perinuclear aggregate but had no effect on the distribution of microtubules. Thus, kinesin is involved not only in organelle movement but also in interaction of the two major cytoskeletal systems, intermediate filaments and microtubules.
TL;DR: In this paper, high tip meander was induced by applying pulses of electrical current locally at the tip of the spiral wave. But the BZ reaction does not exhibit simple periodic rotation, but quasiperiodic rotation, in which the spiral's origin (the tip) meanders.
Abstract: ROTATING spiral waves have been observed in various excitable media, including heart muscle1, retinae2, cultures of the slime mould Dyctiostelium discoideum3,4 and chemical oscillators such as the Belousov-Zhabotinsky (BZ) reaction5–7. Under certain conditions the spiral wave does not exhibit simple periodic rotation, but quasiperiodic8 (or 'compound'9) rotation, in which the spiral's origin (the tip) meanders10. Recent calculations11 have shown that highly meandering tip motion can impose superstructures on spiral waves. Here we reproduce these patterns experimentally, using the BZ reaction as the excitable medium. We induce high tip meander by applying pulses of electrical current locally at the tip12. Image processing of the patterns reveals a spiral wave of larger wavelength superimposed on the original wave, an effect that can be described in terms of a Doppler shift in the original spiral.
01 Jan 1991
TL;DR: Thermodynamics of biopolymers, compressibility, and Ultrasound l/elocity in Dilute Solutions of Biological Substances, hydration of biomolecules, conformational transition, acoustic nonlinearity parameter, and biomedical applications of Ultrasonic’ Velocimetry are studied.
Abstract: KEY WORDS: thermodynamics of biopolymers, compressibility of biomole-cules, hydration of biomolecules, conformational transition,acoustical nonlinearity parameterCONTENTSPerspectives and Overview 321Physical Principles of Ultrasonic Felocimetry 324Instrumentation and Constraints 328Density, Compressibility, and Ultrasound l/elocity in Dilute Solutions ofBiological Substances 330Hydration of Biological Substances and State of Water in the Hydration Shell ......... 331Molecular Transition and Interactions 334Thermodynamics and P- V- T State of Biological Substances in Solution 335Nonlinearity of Molecular Interactions 336Conformational Dynamics of Proteins 337Biomedical Applications of Ultrasonic’ Velocimetry 338Summary and Future Outlook 339
TL;DR: The results prove a significant role of DNA electrophoresis in the phenomenon considered and contradict both assumptions of free DNA diffusion into cell through the long-lived pores and of involvement of osmotic effects in DNA translocation.
TL;DR: In this paper, a method for the generation of high-quality soliton trains at a high repetition rate of gigahertz to tera-hertz range was presented, where a train of practically noninteracting fundamental solitons is formed.
Abstract: The authors present a method for the generation of high-quality soliton trains at a high repetition rate of gigahertz to terahertz range During nonlinear propagation of a continuous-wave (CW) dual-frequency signal through a fiber with effective amplification, a train of practically noninteracting fundamental solitons is formed It is shown that the effective amplification can be achieved as in usual fibers with an actual amplification as well as in fibers with nonuniform parameters along the fiber axis The method is demonstrated experimentally Dual-frequency 25 ps pulses at lambda =155 mu m are reshaped into 02 THz combs of 049 ps solitons in fiber with slowly decreasing dispersion It is also shown that stimulated Brillouin scattering (SBS) can prevent a CW soliton train transmission through optical fibers, and suggests a method for suppression of SBS >