Modelling of large-scale structures arising under developed turbulent convection in a horizontal fluid layer (with application to the problem of tropical cyclone origination)

International audienceThe work is concerned with the results of theoretical and laboratory modelling the processes of the large-scale structure generation under turbulent convection in the rotating-plane horizontal layer of an incompressible fluid with unstable stratification. The theoretical model describes three alternative ways of creating unstable stratification: a layer heating from below, a volumetric heating of a fluid with internal heat sources and combination of both factors. The analysis of the model equations show that under conditions of high intensity of the small-scale convection and low level of heat loss through the horizontal layer boundaries a long wave instability may arise. The condition for the existence of an instability and criterion identifying the threshold of its initiation have been determined. The principle of action of the discovered instability mechanism has been described. Theoretical predictions have been verified by a series of experiments on a laboratory model. The horizontal dimensions of the experimentally-obtained long-lived vortices are 4÷6 times larger than the thickness of the fluid layer. This work presents a description of the laboratory setup and experimental procedure. From the geophysical viewpoint the examined mechanism of the long wave instability is supposed to be adequate to allow a description of the initial step in the evolution of such large-scale vortices as tropical cyclones - a transition form the small-scale cumulus clouds to the state of the atmosphere involving cloud clusters (the stage of initial tropical perturbation)

Влияние функциональной взаимосвязи понятия, образа и действия на процесс решения междисциплинарных технологически ориентированных задач

This article studies the influence of the methods used by students to solve tasks on the effectiveness of the learning process based on their analysis. The study has revealed that mastering the combined method based on the functional relationship between concept, image and action in the process of solving interdisciplinary technological tasks is one of the mechanisms of effective preparation of students for professional activity in the labour market of related professions.En este artículo, basado en un análisis de los métodos utilizados por los estudiantes para resolver problemas, se investiga su influencia en la efectividad del proceso de aprendizaje. En el curso del estudio, se reveló que el dominio del método combinado, basado en la relación funcional del concepto, la imagen y la acción, en el proceso de resolución de problemas tecnológicos interdisciplinarios es uno de los mecanismos para la preparación efectiva de los estudiantes para actividades profesionales en el contexto de la aparición de profesiones relacionadas en el mercado laboral.В данной статье на основе анализа используемых обучающимися способов решения задач исследуется их влияние на результативность процесса обучения. В процессе исследования выявлено, что владение комбинированным способом, основанном на функциональной взаимосвязи понятия, образа и действия, в процессе решения междисциплинарных технологических задач выступает одним из механизмов эффективной подготовки обучающихся к профессиональной деятельности в условиях появления на рынке труда смежных профессий

Diagnostics and therapy of peripheral neuropathy (literature review)

The review is devoted to diagnostics and treatment of neuropathic pain in patients with peripheral nervous system diseases. Main assessment tools are shown including Visual analog Scale (VAS), Neuropathic Pain Scale (NPS), Leeds Assessment of Neuropathic Symptoms and Signs (LANSS), self-report version of the Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS), Neuropathic Pain Questionnaire (NPQ), Questionnaire Douleur Neuropathique 4 (DN-4), pain DETECT Questionnaire, Standardized Evaluation of Pain (StEP), identification pain questionnaire (ID-pain), clinical investigation (quantitative sensorial test are included), neurophysiological studies (electroneuromyography, evoked potentials) and MRI. Novel therapy in neuropathic pain disorders is described including both medicamentous and additional therapeutics methods

Analysis of the results of intraoperative neurophysiological monitoring in the Center of Neurosurgery of Railway Clinical Hospital at the Irkutsk-Passazhirskiy Railway Station of Russian Railways Ltd

The reduction of postoperative complication rate is a significant trend in modern surgery. One of the most important methods of intraoperative diagnostics is intraoperative neurophysiological monitoring (IONM). The aim of the research was to assess capabilities of intraoperative neurophysiological monitoring in neurosurgical practice considering literature data and experience of IONM application in the Center of Neurosurgery Railway Clinical Hospital at the Irkutsk-Passazhirskiy Railway Station of Russian Railways Ltd. We conducted 17 surgeries using IONM. We described the procedure, analyzed data of monitoring and patients' condition in early postoperative period. No deviations requiring modifications in surgical manipulations were found during neuromonitoring. No iatrogenic neurological disorders were registered in postoperative period. Intraoperative neurophysiological monitoring is an additional effective method which allows reducing the risk of postoperative complications and indirectly improving the results of surgical manipulations

Improving the information system of university management

© 2015, Canadian Center of Science and Education. All rights reserved. University management is currently supported by information system providing storage and data structuring of information required. Managing the development and improvement of the educational process quality requires creation of a monitoring system covering all of its objects and various measurement tools, which monitors the set of all features. The paper presents the components of pedagogical management, considers indicators of pedagogical processes and methods of evaluation, which define the basis for monitoring the educational processes at the University. Also the structure of a software module is shown, that works on the principle of the expert system and identifies problem characteristics of the educational activity. The results of the experimental work show the effectiveness of the presented software, that supports management decision-making of university departments’ leadership and faculty

Non-hemagglutinating flaviviruses: molecular mechanisms for the emergence of new strains via adaptation to European ticks

Tick-borne encephalitis virus (TBEV) causes human epidemics across Eurasia. Clinical manifestations range from inapparent infections and fevers to fatal encephalitis but the factors that determine disease severity are currently undefined. TBEV is characteristically a hemagglutinating (HA) virus; the ability to agglutinate erythrocytes tentatively reflects virion receptor/fusion activity. However, for the past few years many atypical HA-deficient strains have been isolated from patients and also from the natural European host tick, Ixodes persulcatus. By analysing the sequences of HA-deficient strains we have identified 3 unique amino acid substitutions (D67G, E122G or D277A) in the envelope protein, each of which increases the net charge and hydrophobicity of the virion surface. Therefore, we genetically engineered virus mutants each containing one of these 3 substitutions; they all exhibited HA-deficiency. Unexpectedly, each genetically modified non-HA virus demonstrated increased TBEV reproduction in feeding Ixodes ricinus, not the recognised tick host for these strains. Moreover, virus transmission efficiency between infected and uninfected ticks co-feeding on mice was also intensified by each substitution. Retrospectively, the mutation D67G was identified in viruses isolated from patients with encephalitis. We propose that the emergence of atypical Siberian HA-deficient TBEV strains in Europe is linked to their molecular adaptation to local ticks. This process appears to be driven by the selection of single mutations that change the virion surface thus enhancing receptor/fusion function essential for TBEV entry into the unfamiliar tick species. As the consequence of this adaptive mutagenesis, some of these mutations also appear to enhance the ability of TBEV to cross the human blood-brain barrier, a likely explanation for fatal encephalitis. Future research will reveal if these emerging Siberian TBEV strains continue to disperse westwards across Europe by adaptation to the indigenous tick species and if they are associated with severe forms of TBE

Finite-size and correlation-induced effects in Mean-field Dynamics

The brain's activity is characterized by the interaction of a very large number of neurons that are strongly affected by noise. However, signals often arise at macroscopic scales integrating the effect of many neurons into a reliable pattern of activity. In order to study such large neuronal assemblies, one is often led to derive mean-field limits summarizing the effect of the interaction of a large number of neurons into an effective signal. Classical mean-field approaches consider the evolution of a deterministic variable, the mean activity, thus neglecting the stochastic nature of neural behavior. In this article, we build upon two recent approaches that include correlations and higher order moments in mean-field equations, and study how these stochastic effects influence the solutions of the mean-field equations, both in the limit of an infinite number of neurons and for large yet finite networks. We introduce a new model, the infinite model, which arises from both equations by a rescaling of the variables and, which is invertible for finite-size networks, and hence, provides equivalent equations to those previously derived models. The study of this model allows us to understand qualitative behavior of such large-scale networks. We show that, though the solutions of the deterministic mean-field equation constitute uncorrelated solutions of the new mean-field equations, the stability properties of limit cycles are modified by the presence of correlations, and additional non-trivial behaviors including periodic orbits appear when there were none in the mean field. The origin of all these behaviors is then explored in finite-size networks where interesting mesoscopic scale effects appear. This study leads us to show that the infinite-size system appears as a singular limit of the network equations, and for any finite network, the system will differ from the infinite system

Somatostatin subtype-2 receptor-targeted metal-based anticancer complexes

Conjugates of a dicarba analogue of octreotide, a potent somatostatin agonist whose receptors are overexpressed on tumor cells, with [PtCl 2(dap)] (dap = 1-(carboxylic acid)-1,2-diaminoethane) (3), [(η 6-bip)Os(4-CO 2-pico)Cl] (bip = biphenyl, pico = picolinate) (4), [(η 6-p-cym)RuCl(dap)] + (p-cym = p-cymene) (5), and [(η 6-p-cym)RuCl(imidazole-CO 2H)(PPh 3)] + (6), were synthesized by using a solid-phase approach. Conjugates 3-5 readily underwent hydrolysis and DNA binding, whereas conjugate 6 was inert to ligand substitution. NMR spectroscopy and molecular dynamics calculations showed that conjugate formation does not perturb the overall peptide structure. Only 6 exhibited antiproliferative activity in human tumor cells (IC 50 = 63 ± 2 μ in MCF-7 cells and IC 50 = 26 ± 3 μ in DU-145 cells) with active participation of somatostatin receptors in cellular uptake. Similar cytotoxic activity was found in a normal cell line (IC 50 = 45 ± 2.6 μ in CHO cells), which can be attributed to a similar level of expression of somatostatin subtype-2 receptor. These studies provide new insights into the effect of receptor-binding peptide conjugation on the activity of metal-based anticancer drugs, and demonstrate the potential of such hybrid compounds to target tumor cells specifically. © 2012 American Chemical Society

STUDY, FORECAST AND CONTROLLED SEISMIC HAZARD REDUCTION IN THE IDENTIFIED SEGMENTS OF THE MAIN FAULTS BY CYCLIC INJECTION OF FLUID THROUGH DEEP MULTI-BRANCH DIRECTIONALLY INCLINED WELLS

The methods developed by the world community to date to withstand strong natural and induced destructive earthquakes do not effectively reduce material losses and the number of victims. The authors propose for discussion an integrated approach to solving the problem of ensuring seismic safety, based on the use of new important information about the geological conditions for earthquake generation. This involved the use of results of numerical and physical modeling, as well as physical full-scale experiments in the natural fault areas. The paper analyzes the petrophysical conditions of deep-seated frictional processes in coseismic faults, revealed through detailed studies of the fragments of paleoearthquake centers that became accessible after their exhumation from seismic-focal depths of the Earth’s crust. The collected information allowed the authors to clarify with a high degree of certainty the origin and occurrence of seismic motions. This paper presents briefly the results of the medium-term forecast of earthquakes with M≥5.0 as applied to the seismodynamic regime of the Baikal rift zone. The forecast emphasizes the detection of places for 1–11-year earthquake generation cycles.A comprehensive analysis of the collected information made it possible to substantiate the conclusion about an opportunity to prevent earthquake damage by using hydrodynamic damping of seismically hazardous fault segments. In the last section, consideration is being given to one of the most promising methods of such man-made impacts, which uses modern technological advances in drilling deep multil-branch and directionally inclined wells with horizontal deviation. The paper discusses the techniques that make it possible to prevent episodes of unexpected reactivation of fault segments in the form of excitation of earthquakes with M≥6.0. Attention is drawn to conducting tests at selected sites in order to improve the technology as part of the approach to earthquake damping