275 research outputs found

    Non-LTE abundances of zinc in different spectral type stars and the Galactic [Zn/Fe] trend based on quantum-mechanical data on inelastic processes in zinc-hydrogen collisions

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    We present a new model atom of Zn I-II based on the most up-to-date photoionisation cross-sections, electron-impact excitation rates, and rate coefficients for the Zn I + H I and Zn II + H- collisions. The latter were calculated using the multi-channel quantum asymptotic treatment based on the Born-Oppenheimer approach. Non-LTE analysis was performed for the first time for lines of Zn I and Zn II in the ultraviolet (UV) spectra of two very metal-poor reference stars, HD 84937 and HD 140283. We found consistent non-LTE abundance from the resonance Zn I 2138 A line, the subordinate lines, and the lines of Zn II. In both stars, non-LTE leads to 0.17 dex higher average abundance from Zn I, while, for Zn II lines, non-LTE corrections are minor and do not exceed 0.06 dex. Using lines of Zn I in the high-resolution spectra, we determined the non-LTE abundances for a sample of 80 stars in the -2.5 < [Fe/H] < 0.2 metallicity range. The [Zn/Fe] versus [Fe/H] diagram reveals a dip, with [Zn/Fe] = 0.3 in the most metal-poor stars, a close-to-solar value for [Fe/H] = -1.2, and increasing [Zn/Fe] up to 0.3 in the thick disk stars. The close-to-solar metallicity stars have subsolar [Zn/H] = -0.1, on average. Non-LTE abundances of zinc were derived for the first time for seven reference F to B-type stars. We provide a grid of the non-LTE abundance corrections.Comment: 15 pages, 9 figures, accepted to MNRA

    Designing an independently installed educational standard for Teacher Education

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    The problem of creating self-established educational standards (SES) is considered by the authors associated with the need to ensure the quality of educational programs and quality of preparation of the future teacher to solve new professional problems. The present work is aimed at scientifically recognising the technology of designing SES. Research methods: theoretical (analysis, synthesis and modelling) and empirical: survey methods (questioning and interviewing

    X-ray film chamber with carbon target of Tien-Shan complex array

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    X-ray films were exposed inside the ionization calorimeter under 74g/sq cm of carbon and 5 cm of lead. The X-ray film chamber area is 35 sq. m. Moving X-ray films were used, 50% of the events, which succeeded to determine incidence time, were identified with corresponding extensive air showers (EAS). For such events the size spectrum of associated EAS was derived. Two methods of energy measurement using X-ray films and ionization calorimeter were compared. The energy transfer from selected hadron to electromagnetic component is illustrated. It is found that in cascades with high energy release into electromagnetic components the hadron component is practically absent

    NGC 7468: a galaxy with an inner polar disk

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    We present our spectroscopic observations of the galaxy NGC 7468 performed at the 6-m Special Astrophysical Observatory telescope using the UAGS long-slit spectrograph, the multipupil fiber spectrograph MPFS, and the scanning Fabry-Perot interferometer (IFP). We found no significant deviations from the circular rotation of the galactic disk in the velocity field in the regions of brightness excess along the major axis of the galaxy (the putative polar ring). Thus, these features are either tidal structures or weakly developed spiral arms. However, we detected a gaseous disk at the center of the galaxy whose rotation plane is almost perpendicular to the plane of the galactic disk. The central collision of NGC 7468 with a gas-rich dwarf galaxy and their subsequent merging seem to be responsible for the formation of this disk.Comment: 8 pages, 6 figures, accepted in Astronomy Letters, 2004, vol 30., N 9, p. 58

    2D Spectroscopy of Candidate Polar-Ring Galaxies: I. The Pair of Galaxies UGC 5600/09

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    Observations of the pair of galaxies VV 330 with the SCORPIO multimode instrument on the 6-m Special Astrophysical Observatory telescope are presented. Large-scale velocity fields of the ionized gas in H-alfa and brightness distributions in continuum and H-alfa have been constructed for both galaxies with the help of a scanning Fabry Perot interferometer. Long-slit spectroscopy is used to study the stellar kinematics. Analysis of the data obtained has revealed a complex structure in each of the pair components. Three kinematic subsystems have been identified in UGC 5600: a stellar disk, an inner gas ring turned with respect to the disk through ~80degrees, and an outer gas disk. The stellar and outer gas disks are noncoplanar. Possible scenarios for the formation of the observed multicomponent kinematic galactic structure are considered, including the case where the large-scale velocity field of the gas is represented by the kinematic model of a disk with a warp. The velocity field in the second galaxy of the pair, UGC 5609, is more regular. A joint analysis of the data on the photometric structure and the velocity field has shown that this is probably a late-type spiral galaxy whose shape is distorted by the gravitational interaction, possibly, with UGC 5600.Comment: 18 pages, 6 figure

    Riistaeläinten populaatioiden dynamiikka Pohjois-Euroopassa: tiivistelmä : 7. kansainvälinen symposium. 24. – 28. Syyskuuta

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    We have studied Black Grouse population abundance and its dynamics in large regions of North-Europe and Urals’ taiga (Finland, Russian Karelia, Murmansk, Arhangel, Kirov and Komi regions and). The data is based on Winter Track Counts (WTC, Priklonski, 1973), where all grouse sightings are recorded. We also studied the longterm Black Grouse abundance changes in Russian and Belarus Natural Reserves (by “Chronical of Natural” Programme, including summer counts of forest grouses): Pinezhsky, Pechoro-Ilychskiy, National Park "Mechera", Nature Reserve "Kivach", "Bryansk Forest", Kostomuksha Nature Reserve Volzhsko-Kamsky National Nature Biosphere Reserve and Visimskiy State Nature Reserves. The highest and most stable abundances of Black Grouse were recorded from East Fennoscandia (Karelia – 3.6 birds per 10 km; Finland – 4.4, coefficient of variation – 12% and 27%, respectively), whereas in the Murmansk and Arkhangelsk Regions and Komi republic, e.g. the species abundance indices were 0.5, 2.5 and 1.1 birds per 10 km, respectively. The “Peak” and minimal abundance years do not concur in different regions of north-European taiga. In Komi in the period from 2001 to 2013, the number of the black grouse declined twice, in Arhangel in the period 30 years – decreased fivefold. In Tatarstan Republic (Volzhsko-Kamsky National Nature Biosphere Reserve) after 1980 abundance decreased rapidly and at last 10 tears – disappeared. In Central Siberia BG are small in numbers and rare. The data suggest Black Grouse abundance varies significantly across Northern Eurasia and among years. One may presume there are some factors acting in different directions: towards convergence and towards divergence of the trends.Peer reviewe

    Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing

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    Ultraviolet radiation shapes seaweed communities

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    Предикторы неблагоприятного течения сердечной недостаточности с сохраненной фракцией выброса левого желудочка у больных с синдромом обструктивного апноэ во сне

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     Aim. To study the relationship of obstructive respiratory disorders during sleep with subclinical development of right ventricular dysfunction and pulmonary hypertension, as well as with the risk of an adverse course of chronic heart failure (CHF) with preserved left ventricular ejection fraction (LVEF).Materials and methods. The study included 86 men with moderate and severe forms of obstructive sleep apnea syndrome (OSAS) (with an apnea/hypopnea index (AHI) &gt; 15 per hour). All patients had abdominal obesity and hypertension. Upon inclusion in the study, all patients underwent polysomnography and echocardiography according to the  standard protocol with an additional assessment of the fractional area  change in the right ventricular myocardium (ΔSRV) and the right ventricular  stroke work index (RVSWI). Also, the content of the N-terminal brain natriuretic peptide precursor (NT-proBNP) in the blood serum was  determined by enzyme immunoassay analysis. A six-minute walk test (6MWT) was performed after inclusion in the study and after 12 months of  follow-up. Depending on the course of CHF during the follow-up,  retrospectively, the patients were divided into 2 groups: with an unfavorable (n = 33) and favorable (n = 53) prognosis.Results. A significant relationship between AHI and ΔSRV, RVSWI, NT-proBNP, and 6MWT was revealed. Based on the results of one-way correlation analysis, it was found that ΔSRV (odds ratio (OR) 2.51; 95%  confidence interval (CI) 2.42–3.24; p = 0.0009), NT-proBNP (OR 1.92; 95% CI  1.32–2.78; p = 0.003), and AHI (OR 3.93; 95% CI 2.87–4.11; p = 0.018) were predictors of an adverse course of CHF. In a multivariate analysis, it was found that AHI was an independent predictor of an adverse course of CHF (OR 3.49; 95% CI 2.17–11.73; p = 0.0008), while the addition of NT-proBNP improved risk stratification of an adverse course of CHF (OR 4.66; 95% CI 3.87–13.11; p &lt; 0.0001).Conclusion. The fractional area change in the right ventricular myocardium (ΔSRV) can be considered as a non-invasive marker for determining the  emerging right ventricular dysfunction and predicting adverse cardiovascular events in patients with preserved LVEF and OSAS. Moreover, the combined use of echocardiographic (ΔSRV) and laboratory (NT-proBNP) markers can improve risk stratification of CHF progression.   Цель. Изучить взаимосвязь обструктивных нарушений дыхания во сне с развитием дисфункции правого желудочка (ПЖ) и легочной гипертензии, а также с риском  неблагоприятного течения хронической сердечной  недостаточности (ХСН) с сохраненной фракцией выброса  левого желудочка (ФВ ЛЖ). Материалы и методы. В исследование включены 86  мужчин со среднетяжелой и тяжелой формами синдрома  обструктивного апноэ во сне (СОАС) (с индексом апноэ/ гипопноэ (ИАГ) более 15 в час). Все пациенты имели  абдоминальное ожирение и артериальную гипертензию.  При включении в исследование всем больным выполнено полисомнографическое исследование, а также  эхокардиография по стандартному протоколу с  дополнительной оценкой фракционного изменения  площади и индекса работы миокарда правого желудочка (ΔSПЖ и ИРМПЖ), определено содержание  предшественника мозгового натрийуретического пептида (NT-proBNP) в сыворотке крови методом  иммуноферментного анализа. Тест 6-минутной ходьбы (ТШХ) выполняли после включения в исследование и через  12 мес наблюдения. В зависимости от характера течения  ХСН за период наблюдения, ретроспективно, пациенты  были разделены на две группы: с неблагоприятным (n = 33) и благоприятным (n = 53) прогнозом.Результаты. Выявлена значимая взаимосвязь между ИАГ и  ΔSПЖ, ИРМПЖ, ТШХ, уровнем NT-proBNP. На основании результатов однофакторного корреляционного анализа  установлено, что ΔSПЖ (отношение шансов (ОШ) 2,51; 95%-й доверительный интервал (ДИ) 2,42–3,24; p = 0,0009), NT- proBNP 1,92; 95%-й ДИ 1,32–2,78; p = 0,003), ИАГ (ОШ 3,93; 95%-й ДИ 2,87–4,11; p = 0,018) были предикторами  неблагоприятного течения ХСН. При проведении  многофакторного анализа установлено, что независимым  предиктором неблагоприятного течения ХСН являлся ИАГ (ОШ 3,49; 95%-й ДИ 2,17–11,73; р = 0,0008), при этом  добавление NT-proBNP улучшало стратификацию риска  неблагоприятного течения ХСН (ОШ 4,66; 95%-й ДИ 3,87–13,11; р &lt; 0,0001).Заключение. Фракционное изменение площади ПЖ ΔSПЖ  можно рассматривать в качестве неинвазивного маркера  для определения формирующейся правожелудочковой  дисфункции и прогнозирования неблагоприятных  сердечно-сосудистых событий у больных с сохраненной ФВ  ЛЖ и СОАС. При этом комбинированное использование  эхокардиографического (ΔSПЖ) и лабораторного (NT- proBNP) маркеров позволяет улучшить стратификацию риска прогрессирования ХСН.
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