Efficiency of Xist-mediated silencing on autosomes is linked to chromosomal domain organisation

BACKGROUND: X chromosome inactivation, the mechanism used by mammals to equalise dosage of X-linked genes in XX females relative to XY males, is triggered by chromosome-wide localisation of a cis-acting non-coding RNA, Xist. The mechanism of Xist RNA spreading and Xist-dependent silencing is poorly understood. A large body of evidence indicates that silencing is more efficient on the X chromosome than on autosomes, leading to the idea that the X chromosome has acquired sequences that facilitate propagation of silencing. LINE-1 (L1) repeats are relatively enriched on the X chromosome and have been proposed as candidates for these sequences. To determine the requirements for efficient silencing we have analysed the relationship of chromosome features, including L1 repeats, and the extent of silencing in cell lines carrying inducible Xist transgenes located on one of three different autosomes. RESULTS: Our results show that the organisation of the chromosome into large gene-rich and L1-rich domains is a key determinant of silencing efficiency. Specifically genes located in large gene-rich domains with low L1 density are relatively resistant to Xist-mediated silencing whereas genes located in gene-poor domains with high L1 density are silenced more efficiently. These effects are observed shortly after induction of Xist RNA expression, suggesting that chromosomal domain organisation influences establishment rather than long-term maintenance of silencing. The X chromosome and some autosomes have only small gene-rich L1-depleted domains and we suggest that this could confer the capacity for relatively efficient chromosome-wide silencing. CONCLUSIONS: This study provides insight into the requirements for efficient Xist mediated silencing and specifically identifies organisation of the chromosome into gene-rich L1-depleted and gene-poor L1-dense domains as a major influence on the ability of Xist-mediated silencing to be propagated in a continuous manner in cis

High energy hadrons in EAS at mountain altitude

An extensive simulation has been carried out to estimate the physical interpretation of dynamical factors such as , in terms of high energy interaction features, concentrated in the present analysis on the average transverse momentum. It appears that the large enhancement observed for versus primary energy, suggesting in earliest analysis a significant rise of with energy, is only the result of the limited resolution of the detectors and remains in agreement with a wide range of models used in simulations.Comment: 13 pages, 6 PostScript figures, LaTeX Subm. to JPhys

Phase Mapping for Cardiac Unipolar Electrograms with Neural Network Instead of Phase Transformation

A phase mapping is an approach to processing signals of electrograms that are recorded from the surface of cardiac tissue. The main concept of the phase mapping is an application of the phase transformation with the aim to obtain signals with useful properties. In our study, we propose to use a simple sawtooth signal instead of a phase of a signal for processing of electrogram data and building of the phase maps. We denote transformation that can provide this signal as a phase-like transformation (PLT). PLT defined via a convolutional neural network that is trained on a dataset from computer models of cardiac tissue electrophysiology. The proposed approaches were validated on data from the detailed personalized model of the human torso electrophysiology. This paper includes visualization of the phase map based on PLT and shows the applicability of the proposed approaches in the analysis of the complex non-stationary periodic activity of the excitable cardiac tissue. © 2020 IEEE.The reported study was funded by RFBR, according to the research project No. 18-31-00401. Development of the mathematical models is supported by IIF UrB RAS theme №AAAA-A19-119070190064-4, RF Government Act №211 of March 16, 2013, the Program of the Presidium RAS

Neuroprotective effects of taurine and 3-hydroxypyridine derivatives in the intracerebral hemorrhage model in rats

At present, the problem of pharmacological correction of free radical processess emerges full-blown. The aim of the study is an experimental study of the neuroprotective effect of taurine and 3-hydroxypyridine derivatives The study was performed in Wistar rats. The neuroprotective effect of the substances was studied in the intracerebral hemorrhage mode

Development of the procedure of testing with the application of the expert evaluation method in psychophysiology

This article provides a detailed description of the stages of development of an information system of personalized psychophysiological testing using expert evaluation. The process of the information system design is presented, the developed functional models, database and algorithm of testing by students-experts are demonstrate

Obstáculos en el aprendizaje de las matemáticas relacionados con deficiencias en la traducción del lenguaje cotidiano al lenguaje matemático y viceversa

El presente trabajo consiste en una serie de reflexiones en torno a los obstáculos en el aprendizaje de las matemáticas que se relacionan con la traducción, del lenguaje cotidiano en que se plantea un problema matemático escolar, al lenguaje matemático y la fase de modelado necesaria para la resolución. Es probable que la influencia del lenguaje no haya recibido mucha atención en la investigación de la matemática educativa, a pesar de los indicadores al respecto de su importancia como mediador de los procesos de aprendizaje complejo, por lo que su estudio podría arrojar información valiosa para determinar su influencia y elaborar estrategias y materiales que atiendan esa situación.Eje: Educación Universitaria ReflexionesRed de Universidades con Carreras en Informática (RedUNCI