681 research outputs found

    Renormalized theory of the ion cyclotron turbulence in magnetic field--aligned plasma shear flow

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    The analytical treatment of nonlinear evolution of the shear-flow-modified current driven ion cyclotron instability and shear-flow-driven ion cyclotron kinetic instabilities of magnetic field--aligned plasma shear flow is presented. Analysis is performed on the base of the nonlinear dispersion equation, which accounts for a new combined effect of plasma turbulence and shear flow. It consists in turbulent scattering of ions across the shear flow with their convection by shear flow and results in enhanced nonlinear broadening of ion cyclotron resonances. This effect is found to lead to the saturation of ion cyclotron instabilities as well as to the development of nonlinear shear flow driven ion cyclotron instability. 52.35.RaComment: 21 page

    Universality in a Class of Q-Ball Solutions: An Analytic Approach

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    The properties of Q-balls in the general case of a sixth order potential have been studied using analytic methods. In particular, for a given potential, the initial field value that leads to the soliton solution has been derived and the corresponding energy and charge have been explicitly evaluated. The proposed scheme is found to work reasonably well for all allowed values of the model parameters.Comment: 9 Pages, 6 Figure

    Metal-insulator transition induced by 16O -18O oxygen isotope exchange in colossal negative magnetoresistance manganites

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    The effect of 16O-18O isotope exchange on the electric resistivity was studied for (La(1-y)Pr(y))0.7Ca0.3MnO3 ceramic samples. Depending on y, this mixed perovskite exhibited different types of low-temperature behavior ranging from ferromagnetic metal (FM) to charge ordered (CO) antiferromagnetic insulator. It was found that at y=0.75, the substitution of 16O by 18O results in the reversible transition from a FM to a CO insulator at zero magnetic field. The applied magnetic field (H >= 2 T) transformed the sample with 18O again to the metallic state and caused the increase in the FM transition temperature Tc of the 16O sample. As a result, the isotope shift of Tc at H = 2 T was as high as 63 K. Such unique sensitivity of the system to oxygen isotope exchange, giving rise even to the metal-insulator transition, is discussed in terms of the isotope dependence of the effective electron bandwidth which shifts the balance between the CO and FM phases.Comment: 5 pages (RevTeX), 2 eps figures included, to appear in J. Appl. Phys. 83, (1998

    Possibilities of using naftidrofuryl in the therapy of cerebrovascular diseases: Literature review and the authors’ observations

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    The efficacy of naftidrofuryl in treating cerebrovascular diseases is analyzed on the basis of a review of the Russian and foreign literature. Naftidrofuryl is a seroton 5-HT2 receptor antagonist and acts on brain energy metabolism mainly during hypoxia or ischemia. The results of preclinical studies proving the antispasmodic and neuroprotective properties of the drug and its capacity to normalize microcirculation in hypoxia are briefly considered. Experimental findings served as a basis for further studies of the efficacy of naftidrofuryl in patients with stroke, chronic cerebral ischemia, or vascular dementia. The use of naftidrofuryl (dusopharm) was demonstrated to statistically significantly enhance the efficiency of rehabilitation in post-stroke patients and to be followed by significant psychoemotional improvement. According to a Cochrane review, the naftidrofuryl-treated patients with vascular dementia showed a tendency towards better executive and cognitive functions, behavior, and mood. The drug was noted to have a positive effect on the health of patients with chronic cerebral ischemia.The authors provide the data of their trial of naftidrofuryl used in patients with dyscirculatory encephalopathy, which have confirmed its efficacy in this category of patients. The data available in the literature suggest that oral naftidrofuryl has a good tolerability and safety profile in patients with cerebrovascular diseases

    Future teachers’ training for learners’ individual projects management

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    © 2016 by iSER, International Society of Educational Research.The relevance of the issue considered in the article concerning the training of future teachers in the higher education institution for learners’ project and research activity as an obligatory component of professional pedagogical education is caused by current trends of social development which sets new tasks for school – keen interest in exceptional and talented children, in the peculiarities of their abilities advancement in the course of education. The leading method of the designated research is the method of content and procedural modeling of higher education institution students vocational competences connected with the arrangement of learners’ project activity. The article contains the experience of future language and literature teachers’ methodical training content development to implement learners’ individual projects arrangement. The authors lay emphasis on the procedural component of future teacher’s vocational training – a step-by-step training aimed to model learners’ individual projects arrangement in the form of an educational project or educational research. The offered material may be useful for bachelors, masters, graduate students trained according to humanitarian programs approved for teachers’ training institutes, as well as for language and literature teachers

    МАРКЕРЫ ВОСПАЛЕНИЯ СОСУДИСТОЙ СТЕНКИ В ПОПУЛЯЦИИ КОРЕННОГО НАСЕЛЕНИЯ НЕНЕЦКОГО АВТОНОМНОГО ОКРУГА

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    Study of inflammatory markers of vascular wall in nenets population showed access of adopted reference values that can indicate serious violations of hemostasis system. However, apparent increase of inflammatory markers of vascular wall in blood can also give evidence of genetic traits of studied population and of necessity of review of reference values of inflammatory markers for studied population of native ethnos of the Arctic Region that is warrant further investigation.Исследование маркеров воспаления сосудистой стенки в выборке ненцев показало превышение принятых референсных значений, что может свидетельствовать о серьезных нарушениях в системе гемостаза. Однако наблюдаемое увеличение маркеров может также говорить о генетических особенностях изучаемой выборки и о целесообразности пересмотра референсных значений маркеров воспаления для исследуемой популяции коренного этноса Арктического региона, что требует дальнейшего изучения

    Semantic features of the phraseological units with the component light within the artistic discourse

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    Conduct lexical and semantic analysis on the concept light in the artistic discourse of postmodern fictio

    Pathogenic characteristics of intracellular infection in chlamydiosis

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    This review analyzes scientific data and systematized information regarding microbiological aspects and pathogenesis of chlamydia infection. Chlamydia are obligate intracellular microorganisms that are sensitive to any human cells where energy parasitism is possible: various types of epithelium, fibrocytes, histiocytes, glial and muscle cells, squamous epithelium of the meninges and eyeball, neurons, monocytes, macrophages. Structure, chemical composition and enzymatic activity of Chlamydia closely resemble those in Gram-negative bacteria, as they retain their morphological identity throughout the life cycle, possess cell wall, ribosomes, DNA, RNA, biochemical elements of glycolysis, tissue respiration, peptose production being sensitive to some broad-spectrum antibiotics, and are able to vegetative form division. In recent decades, the pathogenesis and clinical symptoms of chlamydial lesions in the urogenital tract, nervous, cardiovascular, musculoskeletal and bronchopulmonary systems have been actively studied, and new approaches and treatment schemes for chlamydia-infected patients are still developing. Over many decades, Chlamydia infection has been an important and urgent problem, not only due to its high prevalence, but also because of high rate of complications negatively affecting populational health and related demographic parameters. Chlamydia causes multiple diseases resulting in chronization of inflammatory process in all human organs and systems, and affects reproduction of population. Mandatory statistical recording of chlamydiosis cases introduced as early as in 1994 in the Russian Federation does not reflect the actual incidence rate. A rise in number of inflammatory diseases of the upper respiratory tract caused by Chlamydia undoubtedly increases its etiological importance, but data regarding etiopathogenetic role of Chlamydia in ENT pathology are ambiguous and contradictory. Available publications describe a large range of variation in rate of detected Chlamydia due to poor awareness of doctors about the microbiological properties of chlamydia, pathogenetic and clinical features of clinical signs of this infection, and lack of common and clear understanding on the algorithms for identifying and treating chlamydiosis. Since the majority of chlamydia-associated nosological forms are asymptomatic, knowing pathogenetic features of related will allow to prevent the spread of the infection and reduce subsequent socio-economic consequences
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