544 research outputs found

    Scientometrics: A Tool for Monitoring and Support of Research

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    The origins of scientometrics (research metrics) are discussed. The approaches to research evaluation are reviewed, and the tendency to replacing formal quantitative indicators by expert review based on bibliometric indicators is emphasized. The principles of “Leiden Manifesto of Scientometrics” are set out, providing for transparent monitoring and support of research and encouraging constructive dialog between the scientific community and the public. The methodological framework and the peculiarities of implementation of the information and analytical system “Bibliometryka Ukrayinskoyi Nauky” (“Bibliometrics of the Ukrainian Science”), constructed by the Vernadsky National Library of Ukraine, are shown. The proposals on creating advisory councils, responsible for formulating conclusions on the research effectiveness of institutions, are given. The feasibility of building a common platform for expert evaluation of research for the Eastern Partnership Countries by launching similar bibliometric projects in these countries and their further convergence is considered.Досліджено витоки наукометрії. Розглянуто підходи до оцінювання результативності наукової діяльності та відмічено тенденцію переходу від формальних кількісних індикаторів до отримання експертного висновку на основі бібліометричних показників. Викладено принципи Лейденського маніфесту наукометрії, дотримання яких забезпечує прозорий моніторинг і підтримку розвитку науки, а також сприяє налагодженню конструктивного діалогу між науковим середовищем та суспільством. Показано концептуальні положення і особливості практичної реалізації інформаційно-аналітичної системи «Бібліометрика української науки», розробленої в Національній бібліотеці України імені В. І. Вернадського. Розглянуто пропозиції щодо формування експертних рад, які ухвалюватимуть висновки про ефективність наукової діяльності установ. Обґрунтовано доцільність побудови загальної платформи для експертного оцінювання наукових досліджень країн Східного партнерства шляхом ініціювання аналогічних бібліометричних проектів у цих країнах та їх подальшої конвергенції.Исследованы истоки наукометрии. Рассмотрены подходы к оцениванию результативности научной деятельности и отмечена тенденция перехода от формальных количественных индикаторов к получению экспертного вывода на основе библиометрических показателей. Изложены принципы Лейденского манифеста наукометрии, соблюдение которых обеспечивает прозрачный мониторинг и поддержку развития науки, а также способствует налаживанию конструктивного диалога между научной средой и обществом. Представлены концептуальные положения и особенности практической реализации информационно-аналитической системы «Библиометрика украинской науки», разработанной в Национальной библиотеке Украины имени В. И. Вернадского. Рассмотрены предложения по формированию экспертных советов, которые будут принимать заключения об эффективности научной деятельности учреждений. Обоснована целесообразность построения общей платформы для экспертного оценивания научных исследований стран Восточного партнерства путем инициирования аналогичных библиометрических проектов в этих странах и их последующей конвергенции

    Epigenetics in the primary and secondary prevention of cardiovascular disease: influence of exercise and nutrition

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    Increasing evidence links changes in epigenetic systems, such as DNA methylation, histone modification, and non-coding RNA expression, to the occurrence of cardiovascular disease (CVD). These epigenetic modifications can change genetic function under influence of exogenous stimuli and can be transferred to next generations, providing a potential mechanism for inheritance of behavioural intervention effects. The benefits of exercise and nutritional interventions in the primary and secondary prevention of CVD are well established, but the mechanisms are not completely understood. In this review, we describe the acute and chronic epigenetic effects of physical activity and dietary changes. We propose exercise and nutrition as potential triggers of epigenetic signals, promoting the reshaping of transcriptional programmes with effects on CVD phenotypes. Finally, we highlight recent developments in epigenetic therapeutics with implications for primary and secondary CVD prevention

    Relativistic outflow from two thermonuclear shell flashes on neutron stars

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    We study the exceptionally short (32-41 ms) precursors of two intermediate-duration thermonuclear X-ray bursts observed with RXTE from the neutron stars in 4U 0614+09 and 2S 0918-549. They exhibit photon fluxes that surpass those at the Eddington limit later in the burst by factors of 2.6 to 3.1. We are able to explain both the short duration and the super-Eddington flux by mildly relativistic outflow velocities of 0.1cc to 0.3cc subsequent to the thermonuclear shell flashes on the neutron stars. These are the highest velocities ever measured from any thermonuclear flash. The precursor rise times are also exceptionally short: about 1 ms. This is inconsistent with predictions for nuclear flames spreading laterally as deflagrations and suggests detonations instead. This is the first time that a detonation is suggested for such a shallow ignition column depth (yigny_{\rm ign} = 1010^{10} g cm2^{-2}). The detonation would possibly require a faster nuclear reaction chain, such as bypassing the alpha-capture on 12^{12}C with the much faster 12^{12}C(p,γ\gamma)13^{13}N(α\alpha,p)16^{16}O process previously proposed. We confirm the possibility of a detonation, albeit only in the radial direction, through the simulation of the nuclear burning with a large nuclear network and at the appropriate ignition depth, although it remains to be seen whether the Zel'dovich criterion is met. A detonation would also provide the fast flame spreading over the surface of the neutron star to allow for the short rise times. (...) As an alternative to the detonation scenario, we speculate on the possibility that the whole neutron star surface burns almost instantly in the auto-ignition regime. This is motivated by the presence of 150 ms precursors with 30 ms rise times in some superexpansion bursts from 4U 1820-30 at low ignition column depths of ~108^8 g cm2^{-2}.Comment: 11 pages, 6 figures, accepted by Astronomy and Astrophysic

    Epigenetics in the primary and secondary prevention of cardiovascular disease: influence of exercise and nutrition

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    Increasing evidence links changes in epigenetic systems, such as DNA methylation, histone modification, and non-coding RNA expression, to the occurrence of cardiovascular disease (CVD). These epigenetic modifications can change genetic function under influence of exogenous stimuli and can be transferred to next generations, providing a potential mechanism for inheritance of behavioural intervention effects. The benefits of exercise and nutritional interventions in the primary and secondary prevention of CVD are well established, but the mechanisms are not completely understood. In this review, we describe the acute and chronic epigenetic effects of physical activity and dietary changes. We propose exercise and nutrition as potential triggers of epigenetic signals, promoting the reshaping of transcriptional programmes with effects on CVD phenotypes. Finally, we highlight recent developments in epigenetic therapeutics with implications for primary and secondary CVD prevention

    Management of heart failure patients in Russia: perspectives and realities of the second decade of the XXI century

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    The article highlights the central components of Russian heart failure (HF) management programs in actual clinical practice. The experience of the Competence Center of Almazov National Medical Research Center, as well as opportunities and prospects for improving the monitoring of decompensated HF

    Combined search for the standard model Higgs boson decaying to a bb pair using the full CDF data set

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    We combine the results of searches for the standard model Higgs boson based on the full CDF Run II data set obtained from sqrt(s) = 1.96 TeV p-pbar collisions at the Fermilab Tevatron corresponding to an integrated luminosity of 9.45/fb. The searches are conducted for Higgs bosons that are produced in association with a W or Z boson, have masses in the range 90-150 GeV/c^2, and decay into bb pairs. An excess of data is present that is inconsistent with the background prediction at the level of 2.5 standard deviations (the most significant local excess is 2.7 standard deviations).Comment: To be published in Phys. Rev. Lett (v2 contains minor updates based on comments from PRL

    Observation of Exclusive Gamma Gamma Production in p pbar Collisions at sqrt{s}=1.96 TeV

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    We have observed exclusive \gamma\gamma production in proton-antiproton collisions at \sqrt{s}=1.96 TeV, using data from 1.11 \pm 0.07 fb^{-1} integrated luminosity taken by the Run II Collider Detector at Fermilab. We selected events with two electromagnetic showers, each with transverse energy E_T > 2.5 GeV and pseudorapidity |\eta| < 1.0, with no other particles detected in -7.4 < \eta < +7.4. The two showers have similar E_T and azimuthal angle separation \Delta\phi \sim \pi; 34 events have two charged particle tracks, consistent with the QED process p \bar{p} to p + e^+e^- + \bar{p} by two-photon exchange, while 43 events have no charged tracks. The number of these events that are exclusive \pi^0\pi^0 is consistent with zero and is < 15 at 95% C.L. The cross section for p\bar{p} to p+\gamma\gamma+\bar{p} with |\eta(\gamma)| < 1.0 and E_T(\gamma) > 2.5$ GeV is 2.48^{+0.40}_{-0.35}(stat)^{+0.40}_{-0.51}(syst) pb.Comment: 7 pages, 4 figure

    A search for resonant production of ttˉt\bar{t} pairs in $4.8\ \rm{fb}^{-1}ofintegratedluminosityof of integrated luminosity of p\bar{p}collisionsat collisions at \sqrt{s}=1.96\ \rm{TeV}$

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    We search for resonant production of tt pairs in 4.8 fb^{-1} integrated luminosity of ppbar collision data at sqrt{s}=1.96 TeV in the lepton+jets decay channel, where one top quark decays leptonically and the other hadronically. A matrix element reconstruction technique is used; for each event a probability density function (pdf) of the ttbar candidate invariant mass is sampled. These pdfs are used to construct a likelihood function, whereby the cross section for resonant ttbar production is estimated, given a hypothetical resonance mass and width. The data indicate no evidence of resonant production of ttbar pairs. A benchmark model of leptophobic Z \rightarrow ttbar is excluded with m_{Z'} < 900 GeV at 95% confidence level.Comment: accepted for publication in Physical Review D Sep 21, 201
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