997 research outputs found

    Signum Function Method for Generation of Correlated Dichotomic Chains

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    We analyze the signum-generation method for creating random dichotomic sequences with prescribed correlation properties. The method is based on a binary mapping of the convolution of continuous random numbers with some function originated from the Fourier transform of a binary correlator. The goal of our study is to reveal conditions under which one can construct binary sequences with a given pair correlator. Our results can be used in the construction of superlattices and waveguides with selective transport properties.Comment: 14 pages, 7 figure

    The evaluation of approaches to the treatment of myasthenia gravis.

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    Myasthenia gravis is a relatively rare autoimmune disease with an undetermined aetiology which affects neuromuscular junctions. Currently, the following approaches to the treatment of myasthenia gravis are mainly distinguished: symptomatic treatment with anticholinesterase inhibitors (AChEIs), immunomodulatory therapy (“basic” therapy) with glucocorticoids, cytostatics, monoclonal antibodies; surgical treatment — thymectomy; short-term treatment with plasmapheresis and intravenous administration of immuno­globulin. The efficiency of treatment approaches to myasthenia gravis in Ukraine remains insufficiently studied. The purpose of this work is to analyse the therapeutic approaches in patients with myasthenia gravis depending on the clinical form and severity of the disease. Between 2014 and 2017, 182 patients with myasthenia gravis have been examined, out of which 147 (80.8%) were the patients with the generalized form of the disease and 35 (19.2%) — with its ocular form. The clinical neurological examination included the collection of complaints, an anamnesis of disease and life as well as a neurological examination. In all the patients, the level of antibodies to acetylcholine receptors (AchR) and to muscle-specific tyrosine kinase (MuSK) has been measured, in terms of quantity as well, using the enzyme-linked immunosorbent assay (ELISA), and the presence of antibodies to titin and SOX1 has also been detected by means of indirect immunofluorescence. Of the total sample, less than a third (28.0%) of the patients examined received basic therapy; among them, there were no patients with the ocular form and only 34.7% — with the generalized form (p<0.001). Basic therapy is found more often among the patients with class II myasthenia gravis (51.9%), with a statistically significant (p<0.001) higher share of the patients receiving such a therapy than in classes III and IV (26.6% and 22.6% respectively). The structure of therapy in patients with classes III and IV has not shown any statistically significant difference (p=0.658), with symptomatic treatment being the predominant type of therapy. Undergoing basic therapy reduces the chances of a severe clinical course of myasthenia gravis (the QMG score of 17 and higher) — OR=0.52 (95.0% CI 0.14-0.90), p=0.032; fatal cases of the disease — OR=0.36 (95.0% CI 0.02-0.70), p=0.049. When basic therapy is used, the survival rate of the patients (Figure 2) is 42.0 years on average (95% CI 42.0-42.7) which is considerably higher (p=0.021) compared to that of the patients receiving symptomatic treatment only — 33.0 years (95% CI 30.9-36.7). Immunomodulatory therapy was prescribed for only 28% of the patients in the total sample, for none of the patients with the ocular form of myasthenia gravis, and for 34.7% of the patients with the generalized myasthenia gravis. The prescription of immunomodulatory therapy reduces relative risks of a severe clinical course of myasthenia gravis — OR=0.52 (95.0% CI 0.14-0.90), p=0.032. The prescription of immunomo­dulatory therapy decreases the probability of a fatal outcome of the disease — OR=0.36 (95.0% CI 0.02-0.70), p=0.049). With the use of immunomodulatory therapy, the patient survival rate rises considerably reaching an average of 42.0 years (95% CI 42.0-42.7), which is much higher compared to that in the group of the patients receiving symptomatic treatment only — 33.0 years (95% CI 30.9-36.7), p=0.021

    The right hippocampus leads the bilateral integration of gamma-parsed lateralized information

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    It is unclear whether the two hippocampal lobes convey similar or different activities and how they cooperate. Spatial discrimination of electric fields in anesthetized rats allowed us to compare the pathway-specific field potentials corresponding to the gamma-paced CA3 output (CA1 Schaffer potentials) and CA3 somatic inhibition within and between sides. Bilateral excitatory Schaffer gamma waves are generally larger and lead from the right hemisphere with only moderate covariation of amplitude, and drive CA1 pyramidal units more strongly than unilateral waves. CA3 waves lock to the ipsilateral Schaffer potentials, although bilateral coherence was weak. Notably, Schaffer activity may run laterally, as seen after the disruption of the connecting pathways. Thus, asymmetric operations promote the entrainment of CA3-autonomous gamma oscillators bilaterally, synchronizing lateralized gamma strings to converge optimally on CA1 targets. The findings support the view that interhippocampal connections integrate different aspects of information that flow through the left and right lobes

    ТИПОЛОГИЯ КРИЗИСОВ В СОЦИАЛЬНО-ЭКОНОМИЧЕСКИХ СИСТЕМАХ

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    The causes and problems of crisis in socio-economic systems are considered as the main reason that influences the situation of railways.The indicator of the level of crisis situation in a system is proposed. The crises are classified by institutional sign, which helps to better understand their phenomenon. The study pays special attention to Kondratiev waves (also called supercycles, great surges, long waves, K-waves, the long economic cycle) and the cause-and-effect relations within them. The Kondratiev supercycles are taken as a reference point for the brief relevant study of developments of Russian railways in 19–20th centuries, including the impact of military risks of the reviewed period. The study substantiates the consistency of assessment of a crisis as of the event that is characteristic of a system, organization or economic sector at any stage of their developments. The conclusion accentuates the necessity to promptly assess the risks and to develop crisis management measures for railways, which run primary risks following general economic crises.Рассматриваются причины и проблемы возникновения кризисов в социально-экономических системах, первозначимость их влияния на железнодорожную отрасль. Вводится индикатор кризисности системы. Дается институциональная классификация кризисов, которая помогает глубже понять их феномен. Особое внимание уделено циклам деловой конъюнктуры Николая Кондратьева и их причинно-следственным связям, включая и зону военных рисков. Подтверждается сама закономерность квалификации кризиса как события, характерного для системы на любой стадии развития.

    Off-Critical SLE(2) and SLE(4): a Field Theory Approach

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    Using their relationship with the free boson and the free symplectic fermion, we study the off-critical perturbation of SLE(4) and SLE(2) obtained by adding a mass term to the action. We compute the off-critical statistics of the source in the Loewner equation describing the two dimensional interfaces. In these two cases we show that ratios of massive by massless partition functions, expressible as ratios of regularised determinants of massive and massless Laplacians, are (local) martingales for the massless interfaces. The off-critical drifts in the stochastic source of the Loewner equation are proportional to the logarithmic derivative of these ratios. We also show that massive correlation functions are (local) martingales for the massive interfaces. In the case of massive SLE(4), we use this property to prove a factorisation of the free boson measure.Comment: 30 pages, 1 figures, Published versio

    Microwave realization of quasi one-dimensional systems with correlated disorder

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    A microwave setup for mode-resolved transport measurement in quasi-one-dimensional (quasi-1D) structures is presented. We will demonstrate a technique for direct measurement of the Green's function of the system. With its help we will investigate quasi-1D structures with various types of disorder. We will focus on stratified structures, i.e., structures that are homogeneous perpendicular to the direction of wave propagation. In this case the interaction between different channels is absent, so wave propagation occurs individually in each open channel. We will apply analytical results developed in the theory of one-dimensional (1D) disordered models in order to explain main features of the quasi-1D transport. The main focus will be selective transport due to long-range correlations in the disorder. In our setup, we can intentionally introduce correlations by changing the positions of periodically spaced brass bars of finite thickness. Because of the equivalence of the stationary Schr\"odinger equation and the Helmholtz equation, the result can be directly applied to selective electron transport in nanowires, nanostripes, and superlattices.Comment: 11 pages, 9 figure

    Critical curves in conformally invariant statistical systems

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    We consider critical curves -- conformally invariant curves that appear at critical points of two-dimensional statistical mechanical systems. We show how to describe these curves in terms of the Coulomb gas formalism of conformal field theory (CFT). We also provide links between this description and the stochastic (Schramm-) Loewner evolution (SLE). The connection appears in the long-time limit of stochastic evolution of various SLE observables related to CFT primary fields. We show how the multifractal spectrum of harmonic measure and other fractal characteristics of critical curves can be obtained.Comment: Published versio

    Analysis of the D2O absorption spectrum near 2.5 μm

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    The D2O absorption spectrum recorded with a selective modulation Girard spectrometer in the region of 3690-4190 cm-1 (resolution ∼0.07 cm-1) has been analyzed. Based on the fitting of experimental data the spectroscopic parameters of the vibrational state (011) have been determined and the parameters of the vibrational states (110) and (030) have been estimated. © 1987
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