High-Q bismuth silicate nonlinear glass microsphere resonators

The fabrication and characterization of a bismuth-silicate glass microsphere resonator has been demonstrated. At wavelengths near 1550 nm, high-modes can be efficiently excited in a 179 µm diameter bismuth-silicate glass microsphere via evanescent coupling using a tapered silica fiber with a waist diameter of circa 2 µm. Resonances with Q-factors as high as were observed. The dependence of the spectral response on variations in the input power level was studied in detail to gain an insight into power-dependent thermal resonance shifts. Because of their high nonlinearity and high- factors, bismuth-silicate glass microspheres offer the potential for robustly assembled fully integrated all-optical switching devices

Abnormal behavior, striatal dopamine turnover and opioid peptide gene expression in histamine-deficient mice

Hypothalamic histaminergic neurons regulate a variety of homeostatic, metabolic and cognitive functions. Recent data have suggested a modulatory role of histamine and histamine receptors in shaping striatal activity and connected the histaminergic system to neuropsychiatric disorders. We characterized exploratory behavior and striatal neurotransmission in mice lacking the histamine producing enzyme histidine decarboxylase (Hdc). The mutant mice showed a distinct behavioral pattern during exploration of novel environment, specifically, increased frequency of rearing seated against the wall, jumping and head/body shakes. This behavioral phenotype was associated with decreased levels of striatal dopamine and serotonin and increased level of dopamine metabolite DOPAC. Gene expression levels of dynorphin and enkephalin, opioids released by medium spiny neurons of striatal direct and indirect pathways respectively, were lower in Hdc mutant mice than in control animals. A low dose of amphetamine led to similar behavioral and biochemical outcomes in both genotypes. Increased striatal dopamine turnover was observed in Hdc KO mice after treatment with dopamine precursor l-Dopa. Overall, our study suggests a role for striatal dopamine and opioid peptides in formation of distinct behavioral phenotype of Hdc KO mice.Peer reviewe

Constraint algebra for Regge-Teitelboim formulation of gravity

We consider the formulation of the gravity theory first suggested by Regge and Teitelboim where the space-time is a four-dimensional surface in a flat ten-dimensional space. We investigate a canonical formalism for this theory following the approach suggested by Regge and Teitelboim. Under constructing the canonical formalism we impose additional constraints agreed with the equations of motion. We obtain the exact form of the first-class constraint algebra. We show that this algebra contains four constraints which form a subalgebra (the ideal), and if these constraints are fulfilled, the algebra becomes the constraint algebra of the Arnowitt-Deser-Misner formalism of Einstein's gravity. The reasons for the existence of additional first-class constraints in the canonical formalism are discussed.Comment: LaTeX, 12 pages; in this version the misprints in eq. (37) and (41) was correcte

Адаптация студентов к дистанционному формату обучения

Introduction. The problems that arise for students and teachers in the transition from full-time education to distance learning are considered. The results of the current control and intermediate certification of students received in full-time and distance learning are presented, their comparative analysis is carried out. Purpose setting. The purpose of the study was determined: to generalize the existing experience in organizing distance learning and to create tools for developing skills in working with the software necessary to complete tasks in synchronous and asynchronous learning. The tasks that need to be solved to achieve this goal are listed. Methodology of the study. The research methodology was general scientific methods of theoretical knowledge, methods of analysis and generalization of scientific works devoted to the study of the competency-based approach to the formation of a specialist. Results. The option of supplementing the general competence "Use information technologies in professional activities" with relevant, in the opinion of the author,knowledge and skills is considered. The article presents the algorithm for the development and implementation of the discipline "Business Informatics" in the educational program of the specialty 18.02.12 "Technology of analytical control of chemical compounds", the thematic plan and structure of the work program of the discipline are given. Conclusion. The possibilities of web2.0 services for developing tasks are considered, their functionality is briefly outlined, and an assessment of the listed ones according to the criteria chosen by the author is given.Введение. Рассмотрены проблемы, возникающие у студентов и преподавателей при переходе с очного формата обучения на дистанционный формат. Приведены результаты текущего контроля и промежуточной аттестации обучающихся, полученных в очной форме обучения и дистанционной, проведен их сравнительный анализ. Постановка задачи. Определены цели исследования: обобщение имеющегося опыта работы при организации дистанционного обучения и разработка инструментария для развития навыков работы с программным обеспечением, необходимым для выполнения заданий при синхронном и асинхронном обучении. Перечислены задачи, которые необходимо решить для достижения поставленных целей. Методика и методология исследования. Методологией исследования выступили общенаучные методы теоретического познания, методы анализа и обобщения научных работ, посвященных изучению компетентностного подхода формирования специалиста. Результаты. Рассмотрен вариант дополнения общей компетенции «использовать информационные технологии в профессиональной деятельности» актуальными, на взгляд автора, знаниями и умениями. В статье представлен алгоритм разработки и внедрения в образовательную программу специальности 18.02.12 «Технология аналитического контроля химических соединений» дисциплины «Деловая информатика», приведены тематический план и структура рабочей программы дисциплины. Выводы. Рассмотрены возможности сервисов web2.0 для разработки заданий, кратко обозначен их функционал, приведена оценка перечисленных по выбранным автором критериям

PriorVAE: encoding spatial priors with variational autoencoders for small-area estimation.

Gaussian processes (GPs), implemented through multivariate Gaussian distributions for a finite collection of data, are the most popular approach in small-area spatial statistical modelling. In this context, they are used to encode correlation structures over space and can generalize well in interpolation tasks. Despite their flexibility, off-the-shelf GPs present serious computational challenges which limit their scalability and practical usefulness in applied settings. Here, we propose a novel, deep generative modelling approach to tackle this challenge, termed PriorVAE: for a particular spatial setting, we approximate a class of GP priors through prior sampling and subsequent fitting of a variational autoencoder (VAE). Given a trained VAE, the resultant decoder allows spatial inference to become incredibly efficient due to the low dimensional, independently distributed latent Gaussian space representation of the VAE. Once trained, inference using the VAE decoder replaces the GP within a Bayesian sampling framework. This approach provides tractable and easy-to-implement means of approximately encoding spatial priors and facilitates efficient statistical inference. We demonstrate the utility of our VAE two-stage approach on Bayesian, small-area estimation tasks

The RATAN-600 multi-frequency catalogue of blazars -- BLcat

In this paper we present the RATAN-600 multi-frequency catalogue of blazars, an updated version of the BLcat: the RATAN-600 multi-frequency catalogue of BL Lacertae objects. The main novelty in the catalogue is an extension of the sample with flat-spectrum radio quasars (FSRQs), thus currently it contains more than 1700 blazars of different types. The main feature of the BLcat is a compilation of radio continuum data for blazars based on the RATAN-600 quasi-simultaneous measurements at frequencies of 1.1, 2.3, 4.7, 7.7/8.2, 11.2, and 21.7/22.3 GHz. We additionally supplement the catalogue with the radio data from external sources to provide an opportunity to more complete study of radio spectra and radio light curves. For the convenience of users, we developed tools to calculate the spectral index, variability index, and radio luminosity. We briefly describe basic radio properties of blazar subsamples of the catalogue: spectral classification, spectral indices, flux density variability, and radio luminosity.Comment: 9 pages, 8 figure