69 research outputs found

    Population of higher-energy levels in LiY_(1-x)Er_xF_4 (x=O.003 ÷1) crystals under CW IR laser-diode pumping

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    Steady-state population of 7 lowest excited erbium. levels in LiY¬¬_(1-x)Er_xF_4 (YLF:Er^(3+) (x=0.003-1) crystals was studied under upconversion. CW InGaAs laser-diode pumping with varied power density. Theoretical and experimental concentration and power dependencies of population of higher-energy radiative levels were obtained. Relative changes in populations of studied levels in YLF:Er^(3+) crystals were experimentally controlled by visible spectra of steady-state luminescence in the wavelength ranges corresponding to transitions ^4S_(3/2) --> ^4I(15/2) (0.52--0.57) mum and ^4 F_(9/2) --> ^I_(15/2) (0.64--0.68) µm. IR-pumped luminescence kinetic curves of higher-energy transitions ^4S_(3/2) --> ^4I_(15/2) (0.55 µm) and ^2H_(9/2) --> ^4I_(15/2) (0.41 µm) were recorded. The energy-transfer mechanisms were determined, and the predominant mechanisms responsible for upconversion excitation were elucidated. Microparameters of energy transfer and concentration dependencies of the selfquenching rates and non-linear coupling were obtained on the basis of theoretical and experimental estimates of the rates of intra- and intercenter relaxation processes (migration, selfquenching, and upconversion) allowing for statistics of coupling between the impurity centers in the system. The steady-state dependencies of population on the erbium concentration and pumping power density were calculated within the framework of rate balance equations. Good agreement between the theory and experimental data was obtained

    Species-specific differences in the Pro-Ala rich region of cardiac myosin binding protein-C

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    Cardiac myosin binding protein-C (cMyBP-C) is an accessory protein found in the A-bands of vertebrate sarcomeres and mutations in the cMyBP-C gene are a leading cause of familial hypertrophic cardiomyopathy. The regulatory functions of cMyBP-C have been attributed to the N-terminus of the protein, which is composed of tandem immunoglobulin (Ig)-like domains (C0, C1, and C2), a region rich in proline and alanine residues (the Pro-Ala rich region) that links C0 and C1, and a unique sequence referred to as the MyBP-C motif, or M-domain, that links C1 and C2. Recombinant proteins that contain various combinations of the N-terminal domains of cMyBP-C can activate actomyosin interactions in the absence of Ca2+, but the specific sequences required for these effects differ between species; the Pro-Ala region has been implicated in human cMyBP-C whereas the C1 and M-domains appear important in mouse cMyBP-C. To investigate whether species-specific differences in sequence can account for the observed differences in function, we compared sequences of the Pro-Ala rich region in cMyBP-C isoforms from different species. Here we report that the number of proline and alanine residues in the Pro-Ala rich region varies significantly between different species and that the number correlates directly with mammalian body size and inversely with heart rate. Thus, systematic sequence differences in the Pro-Ala rich region of cMyBP-C may contribute to observed functional differences in human versus mouse cMyBP-C isoforms and suggest that the Pro-Ala region may be important in matching contractile speed to cardiac function across species

    Impact of SARS-CoV-2 on training and mental well-being of surgical gynecological oncology trainees

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    Introduction: The SARS-CoV-2 global pandemic has caused a crisis disrupting health systems worldwide. While efforts are being made to determine the extent of the disruption, the impact on gynecological oncology trainees/training has not been explored. We conducted an international survey of the impact of SARS-CoV-2 on clinical practice, medical education, and mental well-being of surgical gynecological oncology trainees. Methods: In our cross-sectional study, a customized web-based survey was circulated to surgical gynecological oncology trainees from national/international organizations from May to November 2020. Validated questionnaires assessed mental well-being. The Wilcoxon rank-sum test and Fisher's exact test were used to analyse differences in means and proportions. Multiple linear regression was used to evaluate the effect of variables on psychological/mental well-being outcomes. Outcomes included clinical practice, medical education, anxiety and depression, distress, and mental well-being. Results: A total of 127 trainees from 34 countries responded. Of these, 52% (66/127) were from countries with national training programs (UK/USA/Netherlands/Canada/Australia) and 48% (61/127) from countries with no national training programs. Altogether, 28% (35/125) had suspected/confirmed COVID-19, 28% (35/125) experienced a fall in household income, 20% (18/90) were self-isolated from households, 45% (57/126) had to re-use personal protective equipment, and 22% (28/126) purchased their own. In total, 32.3% (41/127) of trainees (16.6% (11/66) from countries with a national training program vs 49.1% (30/61) from countries with no national training program, p=0.02) perceived they would require additional time to complete their training fellowship. The additional training time anticipated did not differ between trainees from countries with or without national training programs (p=0.11) or trainees at the beginning or end of their fellowship (p=0.12). Surgical exposure was reduced for 50% of trainees. Departmental teaching continued throughout the pandemic for 69% (87/126) of trainees, although at reduced frequency for 16.1% (14/87), and virtually for 88.5% (77/87). Trainees reporting adequate pastoral support (defined as allocation of a dedicated mentor/access to occupational health support services) had better mental well-being with lower levels of anxiety/depression (p=0.02) and distress (p<0.001). Trainees from countries with a national training program experienced higher levels of distress (p=0.01). Mean (SD) pre-pandemic mental well-being scores were significantly higher than post-pandemic scores (8.3 (1.6) vs 7 (1.8); p<0.01). Conclusion: SARS-CoV-2 has negatively impacted the surgical training, household income, and psychological/mental well-being of surgical gynecological oncology trainees. The overall clinical impact was worse for trainees in countries with no national training program than for those in countries with a national training program, although national training program trainees reported greater distress. COVID-19 sickness increased anxiety/depression. The recovery phase must focus on improving mental well-being and addressing lost training opportunities

    Role of turbulence and electric fields in the formation of transport barriers and the establishment of improved confinement in tokamak plasmas through inter-machine comparison

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    Over the past decade new regimes of tokamak operation have been identified, whereby electrostatic and magnetic turbulence responsible for anomalous transport, can be externally suppressed, leading to improved confinement. Although turbulence measurements have been performed on many confinement devices, the insight gained from these experiments is relatively limited. To make further progress in the understanding of plasma turbulence in relation to improved confinement and transport barriers, an extensive experimental and theoretical research programme should be undertaken. The present INTAS project investigates the correlations between on the one hand the occurrence of transport barriers and improved confinement in the tokamaks TEXTOR & T-10 and Tore Supra as well as on the smaller-scale tokamaks FT-2, TUMAN-3M and CASTOR, and on the other hand electric fields, modified magnetic shear and electrostatic and magnetic turbulence using advanced diagnostics with high spatial and temporal resolution. This is done in a strongly coordinated way and exploiting the complementarity of TEXTOR and T-10 and the backup potential of the other tokamaks, which together have all the relevant experimental tools and theoretical expertise. Advanced theoretical models and numerical simulations are used to check the experimental results.За останні десять років було отримано нові режими роботи токамаків, у яких електростатична і магнітна турбулентність, відповідальна за аномальний перенос, могла заглушатися шляхом зовнішнього впливу, і тим самим досягалося поліпшене утримання. Незважаючи на те, що дослідження турбулентності проводилися на багатьох установках, розуміння цих процесів залишається досить обмеженим. Для досягнення подальшого прогресу в розумінні плазмової турбулентності з погляду поліпшеного утримання і транспортних бар'єрів необхідні інтенсивні експериментальні і теоретичні дослідження. Проект INTAS спрямовано на з'ясування кореляції між виникненням транспортних бар'єрів і поліпшеного утримання в токамаках TEXTOR, Т-10 і Tore Supra, а також у токамаках малих розмірів ФТ-2, ТУМАН-3М и CASTOR, з одного боку, і електричними полями, модифікованим магнітним широм і електростатичною і магнітною турбулентністю, з іншого боку, з використанням передових діагностичних засобів з високим просторовим і тимчасовим розділенням. Дослідження проводяться з високим ступенем координації робіт і використанням взаємодоповнюваності установок TEXTOR і Т-10, і можливостей інших токамаків, що в сукупності забезпечить необхідну експериментальну і теоретичну перевірку. Для перевірки експериментальних результатів буде використано нові теоретичні моделі і чисельне моделювання.В последние десять лет были получены новые режимы работы токамаков, в которых электростатическая и магнитная турбулентность, ответственная за аномальный перенос, могла подавляться путём внешнего воздействия, и тем самым достигалось улучшенное удержание. Несмотря на то, что исследования турбулентности проводились на многих установках, понимание этих процессов остаётся весьма ограниченным. Для достижения дальнейшего прогресса в понимании плазменной турбулентности с точки зрения улучшенного удержания и транспортных барьеров необходимы интенсивные экспериментальные и теоретические исследования. Проект INTAS направлен на выяснение корреляции между возникновением транспортных барьеров и улучшенного удержания в токамаках TEXTOR, Т-10 и Tore Supra, а также в токамаках малых размеров ФТ-2, ТУМАН-3М и CASTOR, с одной стороны, и электрическими полями, модифицированным магнитным широм и электростатической и магнитной турбулентностью, с другой стороны, с использованием передовых диагностических средств с высоким пространственным и временным разрешением. Исследования проводятся с высокой степенью координации работ и использованием взаимодополняемости установок TEXTOR и Т-10, и возможностей других токамаков, что в совокупности обеспечит необходимую экспериментальную и теоретическую проверку. Для проверки экспериментальных результатов будут использованы новые теоретические модели и численное моделирование

    Dermacentor reticulatus: a vector on the rise

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    Dermacentor reticulatus is a hard tick species with extraordinary biological features. It has a high reproduction rate, a rapid developmental cycle, and is also able to overcome years of unfavourable conditions. Dermacentor reticulatus can survive under water for several months and is cold-hardy even compared to other tick species. It has a wide host range: over 60 different wild and domesticated hosts are known for the three active developmental stages. Its high adaptiveness gives an edge to this tick species as shown by new data on the emergence and establishment of D. reticulatus populations throughout Europe. The tick has been the research focus of a growing number of scientists, physicians and veterinarians. Within the Web of Science database, more than a fifth of the over 700 items published on this species between 1897 and 2015 appeared in the last three years (2013–2015). Here we attempt to synthesize current knowledge on the systematics, ecology, geographical distribution and recent spread of the species and to highlight the great spectrum of possible veterinary and public health threats it poses. Canine babesiosis caused by Babesia canis is a severe leading canine vector-borne disease in many endemic areas. Although less frequently than Ixodes ricinus, D. reticulatus adults bite humans and transmit several Rickettsia spp., Omsk haemorrhagic fever virus or Tick-borne encephalitis virus. We have not solely collected and reviewed the latest and fundamental scientific papers available in primary databases but also widened our scope to books, theses, conference papers and specialists colleagues’ experience where needed. Besides the dominant literature available in English, we also tried to access scientific literature in German, Russian and eastern European languages as well. We hope to inspire future research projects that are necessary to understand the basic life-cycle and ecology of this vector in order to understand and prevent disease threats. We conclude that although great strides have been made in our knowledge of the eco-epidemiology of this species, several gaps still need to be filled with basic research, targeting possible reservoir and vector roles and the key factors resulting in the observed geographical spread of D. reticulatus. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1599-x) contains supplementary material, which is available to authorized users

    COVID-19 Pandemic and Self-isolation: Impact on Bibliometrics and Use. Part II. Citation and Use

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    Introduction. The COVID-19 pandemic creates a unique situation for the advancement of science, scholarly communication and open access (OA). We analyzed the impact of the pandemic on citation metrics and use of scholarly resources.Materials and methods. The study employs original keyword searches and services of WoS CC database and  InCites platform of Clarivate Analytics. It studies citation impact of publications in the datasets of WoS CC,  Clinical Medicine and COVID-publications retrieved with the keyword searches. We studied OA reference groups in WoS CC classification represented by two subsets of publications with the  different number of available copies: Single and Multy. Results and discussion. Citation Impact of COVID-publications in OA reference groups exceeds by 5–10 times  Citation Impact of publications in Clinical Medicine and WoS CC. In 2020, the percent of Single and Multy publications varies around 30 % and 70 % in different reference groups. Due to additional citations collected in  OA repositories, the Citation Impact of COVID-publications in the Multy subset is 2–7 times higher than that in the Single subset. Repository copies of Multy publications of DOAJ, Bronze, Hybrid reference groups, collect, respectively, 85 %, 56 % и 85 % of citations in Multy subset. The Multy subsets of DOAJ, Bronze, Hybrid  reference groups make, respectively, the 76 %, 91 %, 80 % input in average Citation Impact of these groups. The citation patterns of publications of the WoS CC and Clinical Medicine datasets are similar but differ from the citation pattern of COVID-publications.Our study confirmed research hypothesis on increase in use of scholarly resources upon pandemic COVID-19 and self-isolation on the example of resources of OA repositories. The number of visits of repositories in May 2020 exceeds by 2 times the number of visits in May 2019.Conclusion. The pandemic of novel coronavirus resulted in the 10-time increase in Citation Impact of COVID  publications as compared with Citation Impact of publications in other fields of research. Citation Impact of the OA COVID-publications in different reference groups is determined by the articles available in OA repositories and depends by their relative share. This can be a reason of different results of studies Open Access Citation Advantage

    NATIONAL SUBSCRIPTION AND LIBRARY ACQUISITION. PART TWO. THE PRINT AND ELECTRONIC BOOK ACQUISITION IN RUSSIA. STRUCTURE OF RUSSIAN MARKETS OF SCHOLARLY INFORMATION

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    Introduction. The national-level subscription to the global citation indexes Web of Science Core Collection and Scopus and the Freedom Collection of Elsevier released 70% of the electronic acquisition expenditures in the Russian libraries. The article aims at the analysis of the changes in the scope and structure of the book and electronic/print book acquisition budgets in the Russian libraries upon the state-funded national subscription. The article studies changes in the structure of the Russian markets of scholarly information broken in different reference groups.Materials and Methods. The article employs statistical analysis of the survey results. Materials comprise results of the data processing of the Russian surveys on the acquisition budgets in 2016–2018 and published results of the international surveys. We analyze three main reference groups and four sub-groups of the Russian institutions. Results obtained in Russia are compared with the results for American academics.Results. Our findings show that the acquisition budgets of Russian institutions demonstrate a shift towards the book and print book acquisition. Both trends differ from the international ones and the 2022 forecasts of the American libraries. The markets of electronic scholarly information show continuous concentration to the segment of universities. In 2018, relative shares of the university segment of the markets of electronic resources and electronic books made correspondingly 94% and 99%. In the electronic book market, the share of the reference group of the universities of the 5/100 project increased from 24% to 32%, whereas the share of two national universities shrank from 24% to 14%.Discussion and Conclusions. The results obtained probably indicate the effect of the national subscription on the library acquisition. The loss in the market positions of the group of Russian national universities can change leaders in the field of research output

    COVID-19 Pandemic and Self-isolation: Impact on Bibliometrics and Use. Part I. Numbers and Structure of Publication Datasets

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    Introduction. The COVID-19 pandemic is a global challenge but at the same time it creates a unique situation for the advancement of science, scholarly communication and open access (OA). We studied impact of the  pandemic and self-isolation on bibliometric indicators: the number and structure of publications in terms of  fields of research and OA models.Materials and methods. The study employs original keyword searches and services of WoS CC database and InCites platfom of Clarivate Analytics. It studies the dataset of WoS CC and the COVID-publications retrieved with the keyword searches.Results and discussion. In 2020, we see a dramatic increase in the overall number of COVID-publications and a two-time increase in the number of publications in Social Sciences.The structure of the 2020 publications in terms of OA models indicate the 36 % of WoS CC articles and 87 % of COVID articles in OA. The OA journal articles in a single copy make 20 % of WoS CC publications, the OA  articles in multiple copies on the journal platform and in repositories make 60 % of COVID-publications.In 2006, the OA repositories were mainly populated through self-archiving of paywall journal articles, whereas in 2020, the OA journals make the main self-archiving channel. They comprise, respectively, 92 % and  97 % of the input from the WoS CC and COVID datasets.The structure of COVID publications in hybrid and paywall journals has been modified: in 2020, 38 % of articles in those journals were published in hybrid OA. In 2018, that number was 12 %.The proportion of “paywall” articles moved to repositories after the embargo period is low compared to the  possibilities for self-archiving provided by publishers.Conclusion. The pandemic of the novel coronavirus changed the bibliometric indicators of COVID publications: the number and structure of the datasets broken by fields of research and OA models. In the next study, we analyse citation impact and usage of COVID-publications

    NATIONAL SUBSCRIPTION AND LIBRARY ACQUISITION. PART ONE. MATERIAL AND ELECTRONIC ACQUISITION BUDGETS IN RUSSIA

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    Introduction. Electronic acquisition budgets are indicators of the information supply of research and education in the organization and affect its research output. The national level subscription to the global citation indexes Web of Science Core Collection and Scopus and the Freedom Collection of Elsevier released 70% of eleсtronic acquisition expenditures in the Russian libraries. The article studies the effect of the state-funded national subscription on the structure and temporal dynamics of material and electronic acquisition budgets in the Russian libraries.Materials and Methods. Materials comprise results of the data processing of the surveys on acquisition budgets in 2012–2018 and published results of the international surveys. Following our previous studies, we analyzed three main reference groups: universities (with a separate group of the Russian leading universities), research institutions and public libraries. For the purpose of this study, we created additional sub-groups of leading institutions (centers of excellence) in each reference group. From the survey data we calculated the average unit costs (both of the material and electronic acquisition budgets) in each reference group/sub-group. We also calculated relative shares of electronic and print resources in the library material budgets.Results. Since 2016, the material budgets of Russian libraries have grown after the fall caused by the economic crisis in 2014. The state-funded national subscription to the global citation indexes and the Freedom Collection of Elsevier resulted in the 2–4 times decrease in material and electronic acquisition budgets of the centers of excellence in each reference group.Discussion and Conclusions. For the first time, our study revealed the negative effect of the state-funded national subscription on the material and acquisition budgets in Russian organizations. We registered a decrease in the material budgets of the major Russian public and scientific libraries and universities
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