798 research outputs found
Calmodulin as a major calcium buffer shaping vesicular release and short-term synaptic plasticity : facilitation through buffer dislocation
Action potential-dependent release of synaptic vesicles and short-term synaptic plasticity are dynamically regulated by the endogenous Ca2+ buffers that shape [Ca2+] profiles within a presynaptic bouton. Calmodulin is one of the most abundant presynaptic proteins and it binds Ca2+ faster than any other characterized endogenous neuronal Ca2+ buffer. Direct effects of calmodulin on fast presynaptic Ca2+ dynamics and vesicular release however have not been studied in detail. Using experimentally constrained three-dimensional diffusion modeling of Ca2+ influx–exocytosis coupling at small excitatory synapses we show that, at physiologically relevant concentrations, Ca2+ buffering by calmodulin plays a dominant role in inhibiting vesicular release and in modulating short-term synaptic plasticity. We also propose a novel and potentially powerful mechanism for short-term facilitation based on Ca2+-dependent dynamic dislocation of calmodulin molecules from the plasma membrane within the active zone
Health technology in education: Challenges to the effectiveness of the application
The development of healthy and harmonious personality – is the first importance of any modern school. The topical issue of health declining of pupils makes a question about reconsideration of educational system and goal’s correction towards the health technology as a formula to success of developing new generationРазвитие здоровой и гармоничной личности является приоритетом любой школы. Актуальная проблема ухудшения здоровья школьников ставит вопрос о пересмотре системы образования и смещении ориентиров на здоровьесберегающие технологии как залог успеха формирования подрастающего поколени
Socio-economic stratification and the penitentiary system
The development of market relations in Russia, the sharp socioeconomic stratification of the society into rich and poor has given rise to corruption, terrorism, prostitution, the demographic crisis, and the devaluation of the values of family life. The increase in mortality, the decline in the birth rate in Russia are not only because of economic difficulties, but also because of the crisis of the spiritual values of youth and, above all, minorities.
Theoretical and methodological studies of the process of the formation of a spiritually-moral personality were reflected in the fundamental works of philosophers, sociologists, psychologists and teachers. In these conditions, the importance of the educational colonies (EC) for the correction of minors, because of the quality of educational work on them.
The revealed contradictions, relevance and insufficient theoretical elaboration have shown the need for a fundamental, complex and interdisciplinary study of the process of formation of the spiritual and moral values of under-age female convicts in educational colonies, in connection with the development of gender conceptual and methodological foundations for the formation of spiritual and moral values of under-age female convicts in the domestic educational colonies. This is the goal of this study on the basis of the person-centered, pedagogical-axiological, subject and socially-gender approaches.
The outlook of the research consists in the development of the theory and methodology of constructing gender-communicative strategies and tactics for the development of the personal, actionable and cognitive levels of the formation of the spiritual and moral values of under-age female convicts, taking into account the characteristics of their sex.peer-reviewe
Low-rate firing limit for neurons with axon, soma and dendrites driven by spatially distributed stochastic synapses
Analytical forms for neuronal firing rates are important theoretical tools for the analysis of network states. Since the 1960s, the majority of approaches have treated neurons as being electrically compact and therefore isopotential. These approaches have yielded considerable insight into how single-cell properties affect network activity; however, many neuronal classes, such as cortical pyramidal cells, are electrically extended objects. Calculation of the complex flow of electrical activity driven by stochastic spatio-temporal synaptic input streams in these structures has presented a significant analytical challenge. Here we demonstrate that an extension of the level-crossing method of Rice, previously used for compact cells, provides a general framework for approximating the firing rate of neurons with spatial structure. Even for simple models, the analytical approximations derived demonstrate a surprising richness including: independence of the firing rate to the electrotonic length for certain models, but with a form distinct to the point-like leaky integrate-and-fire model; a non-monotonic dependence of the firing rate on the number of dendrites receiving synaptic drive; a significant effect of the axonal and somatic load on the firing rate; and the role that the trigger position on the axon for spike initiation has on firing properties. The approach necessitates only calculating the mean and variances of the non-thresholded voltage and its rate of change in neuronal structures subject to spatio-temporal synaptic fluctuations. The combination of simplicity and generality promises a framework that can be built upon to incorporate increasing levels of biophysical detail and extend beyond the low-rate firing limit treated in this paper
Modernization of Traditional Educational Forms in the Context of Distance Learning
The research aims to reveal the contradictions and issues of higher education in the context of a rapid digital transformation related to the pandemic. We carry out a comparative analysis of students’ academic performance in traditional, distance, and mixed educational formats. Based on the analysis of the literature, teaching practice, and the survey conducted with students, we revealed that despite the visible increase in academic performance during online studying and mixed learning environment, issues regarding technical equipment, stable Internet connection, students’ non-involvement in the educational process, the change of their priorities in favor of part-time job or even the complete loss of communication with the university became more complicated. We conclude that improving the traditional educational form towards more effective ICT adaptation to lectures is crucial, including practical and laboratory classes. It is necessary to conduct classes in a digital format, despite the presence or absence of a pandemic. The mixed learning format will allow us to combine the advantages of traditional and distance learning
Stress-induced thermoelastic martensitic transformations and functional properties in [011]-oriented NiTiHfPd single crystals
The stress-induced martensitic transformation in the [011]-oriented Ni45.3Ti29.7Hf20Pd5 (at. %) single crystals in as-grown, homogenized and aged states were investigated in compression. It is experimentally shown that heat treatments of single crystals result in increase in martensitic transformation temperatures, two-fold decrease in reversible strain and increase in strain-hardening coefficient. As-grown single crystals demonstrate large temperature range of superelasticity (up to 140 K), large reversible strain (up to 4.3%) and large work output in comparison with homogenized and aged crystals
Synaptotagmin 1 oligomers clamp and regulate different modes of neurotransmitter release
Release of neurotransmitters relies on submillisecond coupling of synaptic vesicle fusion to the triggering signal: AP-evoked presynaptic Ca2+ influx. The key player that controls exocytosis of the synaptic vesicle is the Ca2+ sensor synaptotagmin 1 (Syt1). While the Ca2+ activation of Syt1 has been extensively characterized, how Syt1 reversibly clamps vesicular fusion remains enigmatic. Here, using a targeted mutation combined with fluorescence imaging and electrophysiology, we show that the structural feature of Syt1 to self-oligomerize provides the molecular basis for clamping of spontaneous and asynchronous release but is not required for triggering of synchronous release. Our findings propose a mechanistic model that explains how Syt1 oligomers regulate different modes of transmitter release in neuronal synapses
The release of inhibition model reproduces kinetics and plasticity of neurotransmitter release in central synapses
Calcium-evoked release of neurotransmitters from synaptic vesicles (SVs) is catalysed by SNARE proteins. The predominant view is that, at rest, complete assembly of SNARE complexes is inhibited ('clamped') by synaptotagmin and complexin molecules. Calcium binding by synaptotagmins releases this fusion clamp and triggers fast SV exocytosis. However, this model has not been quantitatively tested over physiological timescales. Here we describe an experimentally constrained computational modelling framework to quantitatively assess how the molecular architecture of the fusion clamp affects SV exocytosis. Our results argue that the 'release-of-inhibition' model can indeed account for fast calcium-activated SV fusion, and that dual binding of synaptotagmin-1 and synaptotagmin-7 to the same SNARE complex enables synergistic regulation of the kinetics and plasticity of neurotransmitter release. The developed framework provides a powerful and adaptable tool to link the molecular biochemistry of presynaptic proteins to physiological data and efficiently test the plausibility of calcium-activated neurotransmitter release models
Intuitive Thinking of Artificial Intelligence
The article deals with ways of teaching artificial intelligence by a person before the first person independently applies the developed forms of analysis and data processing schemes. The author, along with others, notes the creative component of artificial intelligence as the most similar to human intuition.В статье рассматриваются способы обучения искусственного интеллекта человеком до самостоятельного применения первым отработанных форм анализа и схем обработки данных. Автор, наряду с прочими, отмечает творческую составляющую искусственного интеллекта в качестве наиболее схожей с человеческой интуицией
The Publishing Life of L. A. Charskoy’s Works
В докладе рассматривается творчество Лидии Алексеевны Чарской — детского писателя начала XX в. описывается жизнь изданий и переизданий ее произведений: от невероятной популярности до полного забвения в начале ХХ в. и возрождения в конце века. Цель исследования — выдвинуть гипотезу причин появления переизданий в наше время, возвращения внимания современного читателя к творчеству Чарской.The report examines the work of Lydia Alekseevna Charskaya, a children’s writer of the early XXth century. The life of publications and reprints of her works is described: from incredible popularity to complete oblivion at the beginning of the twentieth century and revival at the end of the century. The purpose of the study is to put forward a hypothesis of the reasons for the appearance of reprints in our time, the return of the attention of the modern reader to the work of Charskaya
- …