The Influence of Hypoxic Hypoxia and Antiorthostatic Hypokinesia on the Activity of Motoneuron Pools in Man

The paper presents study results of the possible modulating effects of intermittent normobaric hypoxic hypoxia and antiorthostatic hypokinesia on motoneuron pools activity m. soleus and m. gastrocnemius. The unidirectional conditioning of the monosynaptic spinal H-reflex was revealed under non-specific effects of hypoxia and antiorthostasis. After 19 days of exposure, an increase in the amplitudes of the H- and M- responses, activation thresholds of the action potential of Ia sensory fibers was observed, which led to the induction of a maximal H-response in both muscles at a greater stimulus level. There was also a pronounced decrease in the H-reflex depression, which is apparently associated with a weakening effect of suprasegmental control systems in the cumulative effect of a 19-day intermittent (interval) normobaric hypoxic hypoxia and antiorthostatic hypokinesia

Transfer in Implicit Learning

The article describes the research, the aim of which is to discover the effect of transfer of the implicit knowledge of artificial grammar to solving of sensory-motor tasks. The article considers the role of implicit knowledge in actual cognitive activity. Forty volunteers took part in the experiment. Participants of the experiment wereimplicitly taught the rule of artificial grammar. At the control phase, the assignment consisted of solving the sensory-motor problem – to react to the appearance of the green or yellow circle by pressing a certain key. In the experimental group, the grammatical line always appeared before the green-colored circle was presented, and the ungrammatical line appeared before the yellow-colored circle. In the control group the color of the circle didn’t depend on the grammaticality of the line. As a result, we established the considerable reduction in the reaction time in the experimental group. Thus, the transfer of the implicitly learned knowledge of artificial grammar leads to enhancement of efficiency of sensory-motor activity. The implicit rule of artificialgrammar has acquired role of prime-stimulation. Keywords: implicit knowledge, implicit learning, artificial grammar learning, sensorymotor activity, transfer effect, primin

The course of experimental staphylococcus infection in albino mice during action of certain factors of space flight

A study was made of the effect of certain factors of space flight, acceleration and hypokinesia, on the course of experimental staphylococcus infection in mice. Combined action of hypokinesia and acceleration caused a marked depression of the phagocytic activity of leukocytes and formation of a considerable amount of alpha toxin

Temperature dependence of self-trapped exciton luminescence in nanostructured hafnia powder

The intrinsic optical properties and peculiarities of the energy structure of hafnium dioxide largely determine the prospects for applying the latter in new generation devices of optoelectronics and nanoelectronics. In this work, we have studied the diffuse reflectance spectra at room temperature for a nominally pure nanostructured $HfO_2$ powder with a monoclinic crystal structure and, as well its photoluminescence in the temperature range of 40 - 300 K. We have also estimated the bandgap $E_g$ under the assumption made for indirect (5.31 eV) and direct (5.61 eV) allowed transitions. We have detected emission with a 4.2 eV maximum at T < 200 K and conducted an analysis of the experimental dependencies to evaluate the activation energies of thermal quenching (140 meV) and enhancement (3 meV) processes. Accounting for both the temperature behavior of the spectral characteristics and the estimation of the Huang-Rhys factor S >> 1 has shown that radiative decay of self-trapped excitons forms the mechanism of the indicated emission. In this case, the localization is mainly due to the interaction of holes with active vibrational modes of oxygen atoms in non-equivalent ($O_{3f}$ and $O_{4f}$) crystal positions. Thorough study of the discussed excitonic effects can advance development of hafnia-based structures with a controlled optical response.Comment: 21 pages, 7 figures, 2 tables, 56 references. Keywords: hafnium dioxide, self-trapped exciton, F-center, thermal quenching of luminescence, luminescence enhacement, Huang-Rhys factor, effective phonon energy, bandgap widt

A Chebyshev minimax technique oriented to aerospace trajectory optimization problems.

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76822/1/AIAA-6604-910.pd

Mutual Fund Theorem for continuous time markets with random coefficients

We study the optimal investment problem for a continuous time incomplete market model such that the risk-free rate, the appreciation rates and the volatility of the stocks are all random; they are assumed to be independent from the driving Brownian motion, and they are supposed to be currently observable. It is shown that some weakened version of Mutual Fund Theorem holds for this market for general class of utilities; more precisely, it is shown that the supremum of expected utilities can be achieved on a sequence of strategies with a certain distribution of risky assets that does not depend on risk preferences described by different utilities.Comment: 17 page

The role of alkane coordination in C–H bond cleavage at a Pt(II) center

The rates of CFormula H bond activation for various alkanes by [(N–N)Pt(Me)(TFEd3)]+ (N Formula N = ArFormula NFormula C(Me)Formula C(Me)Formula NFormula Ar; Ar = 3,5-di-tert-butylphenyl; TFE-d3 = CF3CD2OD) were studied. Both linear and cyclic alkanes give the corresponding alkene-hydride cation [(N–N)Pt(H)(alkene)]+ via (i) rate determining alkane coordination to form a CFormula H {sigma} complex, (ii) oxidative cleavage of the coordinated CFormula H bond to give a platinum(IV) alkyl-methyl-hydride intermediate, (iii) reductive coupling to generate a methane {sigma} complex, (iv) dissociation of methane, and (v) beta-H elimination to form the observed product. Second-order rate constants for cycloalkane activation (CnH2n), are proportional to the size of the ring (k ~ n). For cyclohexane, the deuterium kinetic isotope effect (kH/kD) of 1.28 (5) is consistent with the proposed rate determining alkane coordination to form a CFormula H {sigma} complex. Statistical scrambling of the five hydrogens of the Pt-methyl and the coordinated methylene unit, via rapid, reversible steps ii and iii, and interchange of geminal CFormula H bonds of the methane and cyclohexane CFormula H {sigma} adducts, is observed before loss of methane

Developing Students’ Skills of Identifying Reliable Scientific Sources: The Role of a Librarian

Purpose. The purpose of this paper is to provide modes of teaching Russian undergraduate students fundamental critical analysis of scientifc papers and ways of identifying misinformation and disinformation in “Academic Writing” discipline. design/methodology/approach. “Academic Writing” discipline was taught to frst-year undergraduate students by scientifc library experts. At a starting period students were asked to complete a questionnaire and perform a test, and then write an essay to identify how students were able to assess Web scientifc literature and verify their “tolerance” to inaccurate and fake scientifc information. Then contact hours on theory and practice of identifying and assessing information were introduced into the curriculum. At the end of the semester lists of works cited in original essays and fnal assays were compared.Findings. The fndings reveal that entirely all frst year undergraduate students lack the ability to differentiate between qualitative certain scientifc information and misinformation and disinformation, and they willingly borrow anything from the Web. However, students acquired necessary skills to assess information critically using socio-technical systems infrastructures.This was demonstrated with list of literature analysis in students’ essays and peer-checking. originality. It is headline news and social networks when it is necessary to distinguish from authentic and inaccurate information. However, skills of critical assessment of scientifc publications are of vital importance at a starting period of studies. In publications of that sort falsifcations, fabrications and other fake discoveries can lead to reputational and fnancial risks, and then trigger unethical demeanour of future researchers. It is qualifed librarians being experts in electronic resources and data based use who are able to get students to “digital hygiene”.Practical implications. The results of the paper can be used for teaching in university curriculum. Embedding information literacy and academic writing as well as involving information resources into students’ curriculum are aimed at the ability to identify misinformation and disinformation. Librarian-developed “Academic writing” discipline component might be introduced into curriculum as a self-contained short course or a composing element of any students’ academic discipline. All this mitigate the risks of applying low-equality, unverifed and openly fake information in educational and scientifc works

ADRENERGIC REGULATION OF IMMUNE RESPONSE UNDER EXPERIMENTAL THYROTOXICOSIS IN RATS

It was established that a changes of antibody production and reaction of delayed—type hypersensitivity at the local immune response to thymus-dependent antigen were opposite in rats with varying severity of experimental thyrotoxicosis — stimulation under a mild form of thyrotoxicosis and depression under more severe form. The increase in glucocorticoid level may be involved in the mechanism of immunosuppression under severe form thyrotoxicosis. The administration of agonist or antagonist of beta-adrenoceptors to animals with thyrotoxicosis led to the significant modification of changes of an immune response parameters, that confirms the participation of an increase in the sensitivity to beta-adrenergic regulation of immune system cells in immunomodulation under thyrotoxicosis