251 research outputs found
MOTIVATIONAL MECHANISMS OF ROSACEA TIDES: Part I
The subject of the study – rosacea tides. The aim of the study was to find out the triggering role of sexual motivations in the development of rosacea tides. These data indicate the role of sexual motivation as a vital need and in case of failure of a number of necessary mechanisms for its implementation there are disorders in the leading centers of regulation of homeostasis, the earliest - in the hemodynamic center, which becomes one of the triggers of labile vascular response. in the centers of the brain and in the microcirculatory tract of the skin.Keywords: rosacea tides, sexual motivation, vascular reactions
Conservation laws for multidimensional systems and related linear algebra problems
We consider multidimensional systems of PDEs of generalized evolution form
with t-derivatives of arbitrary order on the left-hand side and with the
right-hand side dependent on lower order t-derivatives and arbitrary space
derivatives. For such systems we find an explicit necessary condition for
existence of higher conservation laws in terms of the system's symbol. For
systems that violate this condition we give an effective upper bound on the
order of conservation laws. Using this result, we completely describe
conservation laws for viscous transonic equations, for the Brusselator model,
and the Belousov-Zhabotinskii system. To achieve this, we solve over an
arbitrary field the matrix equations SA=A^tS and SA=-A^tS for a quadratic
matrix A and its transpose A^t, which may be of independent interest.Comment: 12 pages; proof of Theorem 1 clarified; misprints correcte
On the classification of conditionally integrable evolution systems in (1+1) dimensions
We generalize earlier results of Fokas and Liu and find all locally analytic
(1+1)-dimensional evolution equations of order that admit an -shock type
solution with .
To this end we develop a refinement of the technique from our earlier work
(A. Sergyeyev, J. Phys. A: Math. Gen, 35 (2002), 7653--7660), where we
completely characterized all (1+1)-dimensional evolution systems
\bi{u}_t=\bi{F}(x,t,\bi{u},\p\bi{u}/\p x,...,\p^n\bi{u}/\p x^n) that are
conditionally invariant under a given generalized (Lie--B\"acklund) vector
field \bi{Q}(x,t,\bi{u},\p\bi{u}/\p x,...,\p^k\bi{u}/\p x^k)\p/\p\bi{u} under
the assumption that the system of ODEs \bi{Q}=0 is totally nondegenerate.
Every such conditionally invariant evolution system admits a reduction to a
system of ODEs in , thus being a nonlinear counterpart to quasi-exactly
solvable models in quantum mechanics.
Keywords: Exact solutions, nonlinear evolution equations, conditional
integrability, generalized symmetries, reduction, generalized conditional
symmetries
MSC 2000: 35A30, 35G25, 81U15, 35N10, 37K35, 58J70, 58J72, 34A34Comment: 8 pages, LaTeX 2e, now uses hyperre
Effect of Cultural Priming on Social Behavior and EEG Correlates of Self-Processing
Humans are social beings and the self is inevitably conceptualized in terms of social environment. The degree to which the self is perceived as fundamentally similar or fundamentally different from other people is modulated by cultural stereotypes, such as collectivism and individualism. These stereotypes are not hardwired in our brains and individuals differ in the degree to which they adopt the attitudes that define their culture. Moreover, individuals can acquire multiple sets of cultural knowledge and, depending on the context, either individualistic or collectivistic cultural mindset could be activated. In this study, we used cultural priming techniques to activate either individualistic or collectivistic mindset and investigated the association between source-level EEG connectivity in the default mode network (DMN) and spontaneous self-related thoughts in the subsequent resting state. Afterward, participants performed a social interaction task, in which they were allowed to choose between friendly, avoidant, or aggressive behavior. After collectivism priming, self-related thoughts were associated with increased connectivity of DMN with the right temporoparietal junction (TPJ), which is involved in taking the perspective of others and is more active in representatives of collectivistic cultures, whereas after individualism priming they were associated with increased connectivity with the temporal pole, which is involved in self/other discrimination and is more active in representatives of individualistic cultures. Individual differences in the intensity of post-priming self-related thoughts and the strength of DMN-temporal pole connectivity predicted individual differences in behavior during the social interaction task, with individualistic mindset predisposing to more friendly and trustful social behavior
Classification of integrable Weingarten surfaces possessing an sl(2)-valued zero curvature representation
In this paper we classify Weingarten surfaces integrable in the sense of
soliton theory. The criterion is that the associated Gauss equation possesses
an sl(2)-valued zero curvature representation with a nonremovable parameter.
Under certain restrictions on the jet order, the answer is given by a third
order ordinary differential equation to govern the functional dependence of the
principal curvatures. Employing the scaling and translation (offsetting)
symmetry, we give a general solution of the governing equation in terms of
elliptic integrals. We show that the instances when the elliptic integrals
degenerate to elementary functions were known to nineteenth century geometers.
Finally, we characterize the associated normal congruences
Biological activity differences between TGF-β1 and TGF-β3 correlate with differences in the rigidity and arrangement of their component monomers
[Image: see text] TGF-β1, -β2, and -β3 are small, secreted signaling proteins. They share 71–80% sequence identity and signal through the same receptors, yet the isoform-specific null mice have distinctive phenotypes and are inviable. The replacement of the coding sequence of TGF-β1 with TGF-β3 and TGF-β3 with TGF-β1 led to only partial rescue of the mutant phenotypes, suggesting that intrinsic differences between them contribute to the requirement of each in vivo. Here, we investigated whether the previously reported differences in the flexibility of the interfacial helix and arrangement of monomers was responsible for the differences in activity by generating two chimeric proteins in which residues 54–75 in the homodimer interface were swapped. Structural analysis of these using NMR and functional analysis using a dermal fibroblast migration assay showed that swapping the interfacial region swapped both the conformational preferences and activity. Conformational and activity differences were also observed between TGF-β3 and a variant with four helix-stabilizing residues from TGF-β1, suggesting that the observed changes were due to increased helical stability and the altered conformation, as proposed. Surface plasmon resonance analysis showed that TGF-β1, TGF-β3, and variants bound the type II signaling receptor, TβRII, nearly identically, but had small differences in the dissociation rate constant for recruitment of the type I signaling receptor, TβRI. However, the latter did not correlate with conformational preference or activity. Hence, the difference in activity arises from differences in their conformations, not their manner of receptor binding, suggesting that a matrix protein that differentially binds them might determine their distinct activities
Digitalization: Mainstream for the University Education and Challenges for the Teachers
Широкомасштабное распространение цифровых технологий, их транснациональность, транскультурность, доступность почти в каждой семье, а также воплощение идей построения цифровой экономики являют собой вызов для российской системы профессионального образования. Ответами на этот вызов, в частности, явились интеграция в образовательные программы вузов открытых образовательных ресурсов, формирование архитектуры профессионального образования на основе сетевых форм взаимодействия в национальном и мировом пространстве, широкое распространение которых сопровождается трудностями и требует дополнительного изучения. Цель данной обзорной статьи – проанализировать ситуацию в области цифровизации высшего образования, определить направления трансформации, условия и факторы занятости преподавателей российских вузов, связанные с внедрением онлайн-курсов в образовательные программы профессионального образования, а также сформулировать и обосновать вопросы, которые требуют изучения в процессе дополнительного эмпирического исследования. Методологическим ориентиром исследования являлись концепции и теории электронного обучения в высшей школе на основе интеграции в образовательный процесс открытых образовательных ресурсов. Информационной базой послужили результаты исследований отечественных и зарубежных ученых по вопросам трансформации процессов получения знаний в современном мире, цифровизации образования, оценки эффектов использования открытых образовательных ресурсов, лояльности к ним университетского сообщества и принятия им онлайн-курсов. В качестве основных методов исследования использованы обзор, анализ и синтез, что дало возможность расширить представление об использовании онлайн-курсов в системе университетского образования и сформулировать исследовательские задачи, которые требуют дополнительного изучения по отношению к преподавателям университетов, интегрирующих онлайн-курсы. Осмысление проанализированных материалов позволило заключить, что интеграция онлайн-курсов в образовательные программы высшего образования – требование времени, обусловленное изменением принципов и технологий передачи и освоения знаний. Ведущие университеты все в большей степени делают ставку на открытые образовательные ресурсы, внедрение которых позволяет получить информационные, технологические, временны́е, экономические, имиджевые эффекты всем сторонам этого процесса (университету, преподавателю, студенту). Впервые в отечественном научном пространстве авторами поставлен вопрос о необходимости изучения: 1) изменений условий занятости преподавателей российских вузов в связи с внедрением онлайн-курсов в образовательные программы; 2) мотивов их деятельности по разработке и поддержанию онлайн-курсов в актуальном состоянии; 3) позиции, связанной с принятием или непринятием онлайн-курсов в профессиональной деятельности. Настоящая статья может быть полезна представителям администрации университетов (в части обобщения информации о внедрении онлайн-курсов в образовательный процесс, а также постановки исследовательских вопросов, изучение и осмысление которых требуется для формирования лояльности преподавательского состава к данной системе обучения и к ее принятию) и преподавателям вузов (в части определения содержания онлайн-курсов и идентификации эффектов от их внедрения). В ближайшее время авторы намерены опубликовать результаты эмпирического исследования восприятия технологий онлайн-обучения вузовскими преподавателями и их отношения к данным технологиям.The extensive dissemination of digital technologies, their transnationality, transculturality, accessibility in almost every family and the implementation of ideas for building a digital economy are a challenge for the Russian system of professional education. The answers to this challenge are, in particular, the integration of open educational resources into the educational programs of higher education institutions, the formation of professional education architecture based on network forms of interaction in the national and global space, their wide extension containing certain difficulties and requiring additional study. The aim of this review article is to analyze the situation in the sphere of digitalization of higher education, to specify the directions of transformation, the conditions and factors of Russian university teachers’ employment associated with the introduction of online courses in the educational programs of professional education, and to formulate and justify issues, which are to be studied in the process of additional empirical research. The methodological reference point of the research is the concepts and theories of e-learning in higher education based on the integration of open educational resources into the educational process. The information base are the results of Russian and foreign scientists’ studies on the transformation of knowledge acquisition processes in the modern world, digitalization of education, evaluation of the effects of using open educational resources, loyalty and acceptance of online courses by the university community. The main research methods are review, analysis and synthesis, which allow to expand the understanding of online courses use in the university education system, and to formulate tasks for additional research of the teachers who integrate online courses. Our analysis shows that the integration of online courses in higher education programs is an epoch’s demand conditioned by changes in the principles and technologies of knowledge transfer and development. Leading universities increasingly rely on open educational resources, the introduction of the latter providing all the participants (the University, the teacher, the student) with information, technological, temporary, economic, and image effects. The Russian scientific space sees here the first raise of the following issues to be studied: 1) changes in the conditions of Russian university teachers’ employment in connection with the introduction of online courses in educational programs; 2) motivation for their activities on development and maintenance of online courses to date; 3) the opinion on the online courses as acceptable or rejectable in their professional activities. This article might be of use for representatives of the university administration (concerning the problems of summarizing information about the introduction of online courses in the educational process, setting research questions to be studied for the formation of teaching staff’s loyalty and acceptance of this or that training system). Of no less interest should it be for any university teacher, as we try to detalize the content of online courses and to identify the effects of their implementation. In the nearest future, the authors intend to publish the results of an empirical study on online learning technologies perception by university teachers and on their attitude to these technologies.Работа над данной статьей С. В. Лобовой поддержана Российским фондом фундаментальных исследований в рамках научного проекта № 19-010-00900 «Влияние прекаризации занятости научно-педагогических работников на кадровый потенциал региональных вузов». Также авторы благодарят анонимных рецензентов, выразивших положительное мнение о статье, что позволило представить ее общественности.S. Lobova’s work on this article is supported by the Russian Federal Property Fund in the framework of the scientific project No. 19-010-00900 «The influence of precarization of the employment of scientific and pedagogical workers on the personnel potential of regional universities». The authors thank anonymous reviewers who expressed a positive opinion about the article, which allowed them to present it to the public
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