171 research outputs found

    Cavity optomechanics with ultra-high Q crystalline micro-resonators

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    We present the first observation of optomechanical coupling in ultra-high Q crystalline whispering-gallery-mode (WGM) resonators. The high purity of the crystalline material enables optical quality factors in excess of 10^{10} and finesse exceeding 10^{6}. Simultaneously, mechanical quality factors greater than 10^{5} are obtained, still limited by clamping losses. Compared to previously demonstrated cylindrical resonators, the effective mass of the mechanical modes can be dramatically reduced by the fabrication of CaF2 microdisc resonators. Optical displacement monitoring at the 10^{-18} m/sqrt{Hz}-level reveals mechanical radial modes at frequencies up to 20 MHz, corresponding to unprecedented sideband factors (>100). Together with the weak intrinsic mechanical damping in crystalline materials, such high sindeband factors render crystalline WGM micro-resonators promising for backaction evading measurements, resolved sideband cooling or optomechanical normal mode splitting. Moreover, these resonators can operate in a regime where optomechanical Brillouin lasing can become accessible

    Implementation of the nonlinear programming algorithm when optimizing the final turning mode

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    For computer-aided multi-variant design of machining technologies, it is important to optimize the cutting parameters at the final pass in each technological operation. When carrying out designing procedures, there emerge problems relating to the algorithm of choosing the decision-making method, the objective function, and the regions of feasibility at final machining steps. Linear programming is time-consuming for multi-variant and multi-pass machining, if the algorithm is to be clear. It is known that when simulating the optimal metal-cutting process, the optimization criterion and the system of constraints are non-linear. Therefore, a computational algorithm can be made significantly more efficient if it is a non-linear algorithm based on Lagrange multipliers Such approach to design helps simplify automating the computational algorithm for multi-pass single-tool machining with a precision cutting tool (a reamer) This is the method discussed herein. © 2020 IOP Publishing Ltd. All rights reserved

    Extended effect of chronic social defeat stress in childhood on behaviors in adulthood

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    Individuals exposed to social stress in childhood are more predisposed to developing psychoemotional disorders in adulthood. Here we use an animal model to determine the influence of hostile social environment in adolescence on behavior during adult life. One-month-old adolescent male mice were placed for 2 weeks in a common cage with an adult aggressive male. Animals were separated by a transparent perforated partition, but the adolescent male was exposed daily to short attacks from the adult male. After exposure to social stress, some of the adolescent mice were placed for 3 weeks in comfortable conditions. Following this rest period, stressed young males and adult males were studied in a range of behavioral tests to evaluate the levels of anxiety, depressiveness, and communicativeness with an unfamiliar partner. In addition, adult mice exposed to social stress in adolescence were engaged in agonistic interactions. We found that 2 weeks of social stress result in a decrease of communicativeness in the home cage and diminished social interactions on the novel territory. Stressed adolescents demonstrated a high level of anxiety in the elevated plus-maze test and helplessness in the Porsolt test. Furthermore, the number of dividing (BrdU-positive) cells in the subgranular zone of the dentate gyrus was significantly lower in stressed adolescents. After 3 weeks of rest, most behavioral characteristics in different tests, as well as the number of BrdU-positive cells in the hippocampus, did not differ from those of the respective control mice. However, the level of anxiety remained high in adult males exposed to chronic social stress in childhood. Furthermore, these males were more aggressive in the agonistic interactions. Thus, hostile social environment in adolescence disturbs psychoemotional state and social behaviors of animals in adult life

    Mathematical model for changing the surface roughness of aluminum alloys when changing the final treatment modes

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    In the process of multivariate design of machining technology, one of the important tasks is the selection of optimal cutting conditions at the final transitions of the shaping process, ensuring a given surface quality on a workpiece made of the corresponding material. At the same time, to describe the majority of design procedures for the machining process, there are problems associated with the algorithm for choosing a solution method, response function, and areas of feasible solutions at all stages of processing. In this paper, as an algorithm for solving the problem, it is proposed to use the well-known technique of extreme experimental design, which allows to obtain a mathematical model of the investigated multifactor process with incomplete knowledge of its optimization mechanism. Such a study allows us to simplify the procedure for setting the processing regime of the workpiece at the final stage in the conditions of the existing production, while ensuring the specified quality of the machined surfaces and maintaining the productivity of the forming process. This technique is the subject of consideration in this work. © 2020 IOP Publishing Ltd. All rights reserved

    Co-expression of glutamatergic and autism-related genes in the hippocampus of male mice with disturbances of social behavior

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    There is a hypothesis of the involvement of the glutamatergic system in the development of autism. It has been shown that the chronic experience in daily intermale confrontations leads to disturbances in social behavior: a decrease in communicativeness, disturbances of socialization, emergence of stereotypical behaviors that can be considered as symptoms of the autistic spectrum disorders. So, the aim of this study was to investigate changes in the expression of glutamatergic (GG) and autism-related (GA) genes in the hippocampus of animals with impaired social behavior caused by repeated experience of social defeat or aggression in daily agonistic confrontations. To form groups of animals with contrasting behaviors, a model of sensory contact (chronic social stress) was used. The collected brain samples were sequenced at JSC Genoanalytica (http://genoanalytica.ru/, Moscow, Russia). Transcriptomic analysis revealed a down-regulation of autism-related (Shank3, Auts2, Ctnnd2, Nrxn2) and glutamatergic (Grm4) genes in aggressive mice. At the same time, the expression of GA-related genes (Shank2, Nlgn2, Ptcdh10, Reln, Arx) and GG genes (Grik3, Grm2, Grm4, Slc17a7, Slc1a4, Slc25a22) excluding Grin2a was increased in defeated mice. Correlative analysis revealed a statistically significant association between GG and GA expression. These results can serve as a confirmation of the participation of the glutamatergic system in the pathophysiology of the autistic spectrum disorder

    Altered Hippocampal Neurogenesis and Amygdalar Neuronal Activity in Adult Mice with Repeated Experience of Aggression

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    Repeated experience of winning in a social conflict setting elevates levels of aggression and may lead to violent behavioral patterns. Here, we use a paradigm of repeated aggression and fighting deprivation to examine changes in behavior, neurogenesis, and neuronal activity in mice with positive fighting experience. We show that for males, repeated positive fighting experience induces persistent demonstration of aggression and stereotypic behaviors in daily agonistic interactions, enhances aggressive motivation, and elevates levels of anxiety. When winning males are deprived of opportunities to engage in further fights, they demonstrate increased levels of aggressiveness. Positive fighting experience results in increased levels of progenitor cell proliferation and production of young neurons in the hippocampus. This increase is not diminished after a fighting deprivation period. Furthermore, repeated winning experience decreases the number of activated (c-fos-positive) cells in the basolateral amygdala and increases the number of activated cells in the hippocampus; a subsequent no-fight period restores the number of c-fos-positive cells. Our results indicate that extended positive fighting experience in a social conflict heightens aggression, increases proliferation of neuronal progenitors and production of young neurons in the hippocampus, and decreases neuronal activity in the amygdala; these changes can be modified by depriving the winners of the opportunity for further fights

    Dysfunction in Ribosomal Gene Expression in the Hypothalamus and Hippocampus following Chronic Social Defeat Stress in Male Mice as Revealed by RNA-Seq

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    Chronic social defeat stress leads to the development of anxiety-and depression-like states in male mice and is accompanied by numerous molecular changes in brain. The influence of 21-day period of social stress on ribosomal gene expression in five brain regions was studied using the RNA-Seq database. Most Rps, Rpl, Mprs, and Mprl genes were upregulated in the hypothalamus and downregulated in the hippocampus, which may indicate ribosomal dysfunction following chronic social defeat stress. There were no differentially expressed ribosomal genes in the ventral tegmental area, midbrain raphe nuclei, or striatum. This approach may be used to identify a pharmacological treatment of ribosome biogenesis abnormalities in the brain of patients with "ribosomopathies.&quot

    Динамика маркеров стресс-реакции при эмболизации маточных артерий

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    Aim. To estimate immunobiochemical markers of the stress response during uterine artery embolization (UAE), and to assess the connection of the endocrine and immune response with pain severity Materials and мethods: 62 patients (ages 31 to 56) with a diagnosis of multiple symptomatic uterine body fibroids were made EMA, and analgesia was achieved by intravenous injection of narcotic and non-narcotic analgesics. Immunobiochemical profile of the stress reaction was investigated (IL-1, IL-6, TNFα, IL-4, IL-10, C-reactive protein (CRP), adrenocorticotropic hormone (ACTH), cortisol, blood glucose) at four (I ONLY SEE 3-SMT) time points (baseline at 2 hours after occlusion of the uterine arteries, and 24 and 48 hours after surgery). Pain syndrome was assessed using a visual analogue scale (VAS) by means of hemodynamic profile.Results. The occlusion of the uterine arteries and ischemia myoma nodes lead to the development of the stress response, as anincrease in the serum concentration of pro-inflammatory (IL-1, IL-6, TNFα) and anti-inflammatory (IL-4, IL-10) cytokines, CRP, stress hormones (ACTH, cortisol) levels of glucose was observed. Pain of various intensity was recorded in all cases, and 18% of patients experienced marked pain (7 to 10 points on the VAS).Conclusion. The maximum increase in immunobiochemical stress markers coincides with the highest manifestations of pain. The necessity of optimization methods of analgesia when performing EMA with the use of immunobiochemical stress markers as a control reaction taking into account hemodynamic profile and VAS data was observed.Цель исследования. Оценка иммунобиохимических маркеров стресс-реакции при эмболизации маточных артерий (ЭМА), оценка связи выраженности эндокринного и иммунного ответа с выраженностью болевого синдрома.Материал и методы. Пациенткам (n = 62) в возрасте 31–56 лет с диагнозом «симптомная множественная миома тела матки» выполнена ЭМА, анальгезия достигалась внутривенным введением наркотических и ненаркотических анальгетиков. Исследован иммунобиохимический профиль стресс-реакции (IL-1, IL-6, TNFα, IL-4, IL-10, С-реактивный протеин (CRP), адренокортикотропный гормон (АКТГ), кортизол, глюкоза крови) в динамике, на четырех точках контроля (исходный уровень, через 2 ч после окклюзии маточных артерий, через 24 и 48 ч после операции). Болевой синдром оценивался по визуально-аналоговой шкале (ВАШ), с помощью гемодинамического профиля.Результаты. Окклюзия маточных артерий и ишемия в миоматозных узлах ведет к развитию стресс-реакции: увеличение концентрации в сыворотке крови провоспалительных (IL-1, IL-6, TNFα) и противовоспалительных (IL-4, IL-10) цитокинов, CRP, гормонов стресса (АКТГ, кортизола), уровня гликемии. Болевой синдром разной степени интенсивности регистрируется в 100% случаев, 18% пациенток испытывали выраженные болевые ощущения (7–10 баллов по ВАШ).Заключение. Максимальный прирост иммунобиохимических маркеров стресса совпадает по времени с максимальными проявлениями болевого синдрома. Выявлена необходимость оптимизации методов анальгезии при выполнении ЭМА с использованием в качестве контроля иммунобиохимических маркеров стресс-реакции, учитывая гемодинамический профиль и данные ВАШ

    Distribution maps of vegetation alliances in Europe

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    Aim The first comprehensive checklist of European phytosociological alliances, orders and classes (EuroVegChecklist) was published by Mucina et al. (2016, Applied Vegetation Science, 19 (Suppl. 1), 3–264). However, this checklist did not contain detailed information on the distribution of individual vegetation types. Here we provide the first maps of all alliances in Europe. Location Europe, Greenland, Canary Islands, Madeira, Azores, Cyprus and the Caucasus countries. Methods We collected data on the occurrence of phytosociological alliances in European countries and regions from literature and vegetation-plot databases. We interpreted and complemented these data using the expert knowledge of an international team of vegetation scientists and matched all the previously reported alliance names and concepts with those of the EuroVegChecklist. We then mapped the occurrence of the EuroVegChecklist alliances in 82 territorial units corresponding to countries, large islands, archipelagos and peninsulas. We subdivided the mainland parts of large or biogeographically heterogeneous countries based on the European biogeographical regions. Specialized alliances of coastal habitats were mapped only for the coastal section of each territorial unit. Results Distribution maps were prepared for 1,105 alliances of vascular-plant dominated vegetation reported in the EuroVegChecklist. For each territorial unit, three levels of occurrence probability were plotted on the maps: (a) verified occurrence; (b) uncertain occurrence; and (c) absence. The maps of individual alliances were complemented by summary maps of the number of alliances and the alliance–area relationship. Distribution data are also provided in a spreadsheet. Conclusions The new map series represents the first attempt to characterize the distribution of all vegetation types at the alliance level across Europe. There are still many knowledge gaps, partly due to a lack of data for some regions and partly due to uncertainties in the definition of some alliances. The maps presented here provide a basis for future research aimed at filling these gaps
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