Structures and orientational transitions in thin films of tilted hexatic smectics

We present detailed systematic studies of structural transformations in thin liquid crystal films with the smectic-C to hexatic phase transition. For the first time all possible structures reported in the literature are observed for one material (5 O.6) at the variation of temperature and thickness. In unusual modulated structures the equilibrium period of stripes is twice with respect to the domain size. We interpret these patterns in the frame work of phenomenological Landau type theory, as equilibrium phenomena produced by a natural geometric frustration in a system having spontaneous splay distortion.Comment: 7 pages, 6 figure

Informative modeling of subjective reality for intellectual anthropomorphic robots

This research is aimed at solving the problem of safeguarding robot operation by modeling the subjective reality of an intellectual anthropomorphic robot. Analysis has been carried out on trends in designing advanced robot control systems and methods of improving the safety of robot usage. The following conclusions are drawn: the risk of causing damage to human life, health or property increases when people interact with robots; it is necessary to combine neural network control systems with expert control systems in order to enhance the intellect of a robot and raise the level of trust held by humans towards robots; developing norms and regulations, designing collaborative robots, drawing visualization diagrams for safety zones cannot really provide the depth of robot socialization sufficient for the human society; an informative model of the subjective reality could be integrated into an intellectual anthropomorphic robot to provide a safer 'human-robot' interaction. Such an approach should result in achieving the greatest trust of humans and their safety due to anthropomorphic conversion of both the external design of a robot and its internal control structure. By its nature, the research is interdisciplinary - it is run in the fields of artificial intelligence and philosophy of subjective reality. © Published under licence by IOP Publishing Ltd

Inhibition of Respiration by Nitric Oxide Induces a Mycobacterium tuberculosis Dormancy Program

An estimated two billion persons are latently infected with Mycobacterium tuberculosis. The host factors that initiate and maintain this latent state and the mechanisms by which M. tuberculosis survives within latent lesions are compelling but unanswered questions. One such host factor may be nitric oxide (NO), a product of activated macrophages that exhibits antimycobacterial properties. Evidence for the possible significance of NO comes from murine models of tuberculosis showing progressive infection in animals unable to produce the inducible isoform of NO synthase and in animals treated with a NO synthase inhibitor. Here, we show that O2 and low, nontoxic concentrations of NO competitively modulate the expression of a 48-gene regulon, which is expressed in vivo and prepares bacilli for survival during long periods of in vitro dormancy. NO was found to reversibly inhibit aerobic respiration and growth. A heme-containing enzyme, possibly the terminal oxidase in the respiratory pathway, likely senses and integrates NO and O2 levels and signals the regulon. These data lead to a model postulating that, within granulomas, inhibition of respiration by NO production and O2 limitation constrains M. tuberculosis replication rates in persons with latent tuberculosis

A Bistable Switch and Anatomical Site Control Vibrio cholerae Virulence Gene Expression in the Intestine

A fundamental, but unanswered question in host-pathogen interactions is the timing, localization and population distribution of virulence gene expression during infection. Here, microarray and in situ single cell expression methods were used to study Vibrio cholerae growth and virulence gene expression during infection of the rabbit ligated ileal loop model of cholera. Genes encoding the toxin-coregulated pilus (TCP) and cholera toxin (CT) were powerfully expressed early in the infectious process in bacteria adjacent to epithelial surfaces. Increased growth was found to co-localize with virulence gene expression. Significant heterogeneity in the expression of tcpA, the repeating subunit of TCP, was observed late in the infectious process. The expression of tcpA, studied in single cells in a homogeneous medium, demonstrated unimodal induction of tcpA after addition of bicarbonate, a chemical inducer of virulence gene expression. Striking bifurcation of the population occurred during entry into stationary phase: one subpopulation continued to express tcpA, whereas the expression declined in the other subpopulation. ctxA, encoding the A subunit of CT, and toxT, encoding the proximal master regulator of virulence gene expression also exhibited the bifurcation phenotype. The bifurcation phenotype was found to be reversible, epigenetic and to persist after removal of bicarbonate, features consistent with bistable switches. The bistable switch requires the positive-feedback circuit controlling ToxT expression and formation of the CRP-cAMP complex during entry into stationary phase. Key features of this bistable switch also were demonstrated in vivo, where striking heterogeneity in tcpA expression was observed in luminal fluid in later stages of the infection. When this fluid was diluted into artificial seawater, bacterial aggregates continued to express tcpA for prolonged periods of time. The bistable control of virulence gene expression points to a mechanism that could generate a subpopulation of V. cholerae that continues to produce TCP and CT in the rice water stools of cholera patients

Investigation of the neuro-electrostimulation mechanisms by means of the functional MRI: Case study

The article overviewed contemporary neuromodulation approaches and challenges. The importance of the neurostimulation techniques was justified. The SYMPATHOCOR-01 neuro-electrostimulation device characterization was presented. The case study of the neuro-electrostimulation mechanisms by means of the neuroimaging was described. Case study consisted of 3 phases: imaging prior to the neuro-electrostimulation procedure, imaging right after the neuro-electrostimulation procedure and imaging after a 5-day stimulation course. Results of the functional magnetic resonance imaging revealed improvement of the functional connectivity strength in several brain regions as well as normalization of default mode network activity. Copyright © 2018 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved.The work was supported by Act 211 Government of the Russian Federation, contract № 02.A03.21.0006. The authors thank Ivan Brak, Elena Filimonova and Eugenia Kobeleva for participation in the data processing

Обработка сигналов ЭКГ с помощью вейвлет-анализа: диагностические возможности

The problem of recognition and classification of biomedical signals is a complex problem related to the interdisciplinary field of computer science and medicine. Within the framework of the project implementation of the development of the new defibrillation equipment, it is necessary to solve the problems of analyzing biomedical signals of the electrocardiogram to obtain a diagnostic solution with the possibility of assigning a specific condition to the pathological condition of the patient. This article presents the analysis of electrocardiogram signals, considering the technical aspects of the analysis of multicomponent signals, and describes the diagnostic possibility of wavelet analysis of ECG signals. The paper considers the limited tools of analyzing the electrocardiogram signal, in particular, limitation of parametric data. Wavelet analysis may significantly expand the analysis of signals and transfer them into the time-frequency domain. Thus, the use of various basic functions of the wavelet transform leads to the determination of the additional diagnostically significant information formalized in the parameters extracted from the wavelet scalogram. Chupov A. A., Zhdanov A. E., Rakhmatullov F. K., Rakhmatullov R. F., Dolganov A. Yu. ECG Signals Processing by Using Wavelet Analysis: Diagnostic Capabilities. Ural Radio Engineering Journal. 2021;5(4):337–352. (In Russ.) DOI: 10.15826/urej.2021.5.4.001.Задача распознавания и классификации биомедицинских сигналов является комплексной задачей, относящейся к междисциплинарной области компьютерных наук и медицины. В рамках реализации проекта по разработке нового деффибрилляционного оборудования необходимо решить задачи анализа биомедицинских сигналов электрокардиограммы для получения диагностического решения с возможностью отнесения конкретного состояния к патологическому состоянию пациента. В настоящей статье представлен анализ сигналов электрокардиограммы, учитывающий технические аспекты анализа многокомпонентных сигналов, также описана диагностическая возможность вейвлет-анализа сигналов. Учитывая ограниченный инструментарий анализа сигнала электрокардиограммы с точки зрения набора параметрических данных, вейвлет-анализ позволяет значительно расширить анализ сигналов и перейти в частотно-временную область. Таким образом, использование различных базисных функций вейвлет-преобразования позволяет определить дополнительную диагностически значимую информацию, формализованную в параметрах, извлекаемых из вейвлет-скалограм. Чупов А. А., Жданов А. Е., Князев С. Т., Рахматуллов Ф. К., Рахматуллов Р. Ф., Долганов А. Ю. Обработка сигналов ЭКГ с помощью вейвлет-анализа: диагностические возможности. Ural Radio Engineering Journal. 2021;5(4):337–352. DOI: 10.15826/urej.2021.5.4.001.