414 research outputs found
GR 290 (Romano's Star): 2. Light history and evolutionary state
We have built the historical light curve of the luminous variable GR 290 back
to 1901, from old observations of the star found in several archival plates of
M 33. These old recordings together with published and new data show that for
at least half a century the star was in a low luminosity state, with B ~18.
After 1960, five large variability cycles of visual luminosity were recorded.
The amplitude of the oscillations was seen increasing towards the 1992-1994
maximum, then decreasing during the last maxima. The recent light curve
indicates that the photometric variations have been quite similar in all the
bands, and that the B-V color index has been constant within +/-0.1 m despite
the 1.5m change of the visual luminosity. The spectrum of GR 290 at the large
maximum of 1992-94, was equivalent to late-B type, while, during 2002-2014, it
has varied between WN10h-11h near the visual maxima to WN8h-9h at the
luminosity minima. We have detected, during this same period, a clear
anti-correlation between the visual luminosity, the strength of the HeII 4686 A
emission line, the strength of the 4600-4700 A lines blend and the spectral
type. From a model analysis of the spectra collected during the whole 2002-2014
period we find that the Rosseland radius R_{2/3}, changed between the minimum
and maximum luminosity phases by a factor of 3, while T_eff varied between
about 33,000 K and 23,000 K. The bolometric luminosity of the star was not
constant, but increased by a factor of ~1.5 between minimum and maximum
luminosity, in phase with the apparent luminosity variations. In the light of
current evolutionary models of very massive stars, we find that GR 290 has
evolved from a ~60 M_Sun progenitor star and should have an age of about 4
million years. We argue that it has left the LBV stage and is moving to a
Wolf-Rayet stage of late nitrogen spectral type.Comment: Accepted on The Astronomical Journal, 10 figures. Replaced because
the previous uploaded file was that without the final small corrections
requested by the refere
Expression of a quantitative character radius incompletus, temperature effects, and localization of a mobile genetic element Dm-412 in Drosophila melanogaster
Methods for investigating the mechanical properties of isolated subendocardial and subepicardial cells ffom mouse heart
Supported by the Russia Foundation for Basic Research (14-01-00885, 14-01-31134, 13-04-00365) and JSPS KAKENHI2628212
CONDITION OF THE ERYTHROID PART OF BLOOD SYSTEM AT STRESSED ANIMALS WITH HYPOTHYREOSIS
Hypothyreosis, caused by introduction of mercazolil, leads to reduction of production of thyroid hormones, destabilization of membranes and. acceleration of erythrocytes destruction, activation of erythropoiesis, development of macroerythrocytosis in blood. In 28 days after cancelling of mercazolil reserves of red bone marrow are exhausted, in blood microerythrocytosis accrues. The stress in animals with hypothyreosis does not change the composition of blood erythrocytes and activity of erythrocytopoiesis, but promotes preservation of a marrowy reserve of erythrocytes and increases a level of thyroid hormones
Влияние задымления атмосферного воздуха в период аномальной жары на показатели заболеваемости и смертности по причине острых и хронических болезней дыхательной системы
Summary. Atmospheric air pollutants can cause pathologic response of airways and the total organism ranging from irritation of the airway mucosa to severe allergic reactions and bronchopulmonary diseases. Besides of anthropogenic sources the environmental smoke can originate from natural disasters such as earthquakes and fires. Solar irradiation can overheat the atmosphere and catalyze interactions between toxic air substances followed by fires and synthesis of new hazard chemicals. One of such natural phenomena was abnormally hot summer with extensive fires in 2010. Findings of ecological, statistical and healthcare emergency facilities of Moscow region showed a significant growth in respiratory morbidity and mortality during extreme smoke and abnormal heat. Number of emergency calls due to bronchopulmonary diseases was twice higher than in 2008 and 2009. The most frequent cause of seeking the emergency aid were bronchial asthma, acute bronchitis, and exacerbation of chronic obstructive pulmonary disease.Резюме. Поллютанты, содержащиеся в атмосферном воздухе, способны вызвать у гиперчувстительных людей негативные реакции со стороны дыхательных путей и всего организма – от раздражения слизистых оболочек респираторного тракта до развития тяжелых аллергических реакций и заболеваний бронхолегочной системы. Помимо техногенного воздействия причиной загрязнения окружающей среды могут стать природные катаклизмы – землетрясения и пожары. Лучистая энергия солнца способствует перегреванию слоев атмосферы и усилению реакций между токсическими субстанциями воздуха, приводящих к развитию пожаров с образованием новых химических соединений, опасных для здоровья. Ярким примером природных аномальных явлений является жара летом 2010 г., сопровождавшаяся обширными пожарами. На основании проведенного анализа данных ГПУ "Мосэкомониторинга", материалов Управления ЗАГС, ФГУЗ ЦГЭМ и сведений со станций скорой медицинской помощи регионов Подмосковья были получены результаты, свидетельствующие о значительном росте числа случаев заболеваний органов дыхания и увеличении смертности в периоды максимального задымления воздуха на фоне аномальной жары. Показатели количества вызовов скорой помощи по причине бронхолегочных заболеваний в июле–августе 2010 г. превышали таковые в 2008 и 2009 гг. в ≥ 2 раза. Наиболее частой причиной обращений за скорой помощью были бронхиальная астма, острый бронхит, обострение хронической обструктивной болезни легких
The incidence of maternity and newborn infections associated with the provision of medical care in obstetric hospitals in Yekaterinburg
The purpose of the study is to study the manifestations of cysts and cystic formations in the lungs, their semiotics and scialogy for further analysis of computed tomograms and analysis of a clinical case.Цель исследования – изучить проявления кист и кистозных образований в легких, их семиотику и скиалогию для дальнейшего анализа компьютерных томограмм и разбора клинического случая
The study of the educational process with the use of electronic learning tools for schoolchildren of grades 6 – 8
The purpose of the study is to study the educational process with the use of ESO in the school N. and recommendations for optimizing the educational process in order to prevent fatigue.Цель исследования – изучение образовательного процесса с применением ЭСО в МБОУ СОШ г. N. и рекомендации по оптимизации учебного процесса с целью профилактики утомления
Specific shoot formation in Miscanthus sacchariflorus (Poaceae) under different environmental factors and DNA passportization using ISSR markers
The generic complex Miscanthus Anderss. (Poaceae) is a unique example among herbaceous plants characterized by high values of growth of aboveground vegetative mass and practical use as a valuable source of alternative energy. Miscanthus is one of the most efficient solar energy accumulators, and since phytomeliorative use implies the cultivation of these resource plants in inconvenient and semi-shady areas, the question about the effect of insufficient lighting on the productivity of Miscanthus arises. As a result of a long-lasing introduction effort, the Central Siberian Botanical Garden SB RAS created a population of Miscanthus sacchariflorus (Maxim.) Benth., which has good prospects for growing under the conditions of the forest-steppe area in Western Siberia. The goals of our study were: (1) to determine the peculiarities of shoot formation, (2) to assess the cellulose and lignin accumulation in M. sacchariflorus populations under different lighting conditions and (3) to perform a DNA passportization of the Miscanthus population by ISSR marking. Evaluation of shoot formation and the amount of accumulated cellulose and lignin in plants was carried out under different degrees of illumination: one variant was grown in a sunny area, and the other, in partial shade. As a result of analysis of variance, it was found that the number of shoots does not depend on environmental conditions, but on the age of the plant, while environmental conditions have a significant effect on plant height. Although the samples of both M. sacchariflorus variants were characterized by different rates of creation of a continuous projective cover, plants in semi-shaded areas formed up to 89.34 % of shoots compared to their peers in illuminated areas, which did not affect significantly the size of the aboveground mass and the cellulose content in it. As a result of ISSR-analysis of genomic DNA in the M. sacchariflorus population, unique molecular polymorphic fragments were identified, which can be used for identification and DNA passportization at the inter-population level. Thus, the complex use of M. sacchariflorus as a valuable meliorative and bioenergetic culture is due to the high adaptive potential of this species. It was found that the illumination factor has virtually no effect on the amount of the cellulose content in the shoot, and a reduced content of the technologically undesirable lignin was observed in plants growing in the partial shade conditions
3D RECONSTRUCTION OF THE ANCIENT EGYPTIAN MUMMY SKELETON FROM THE PUSHKIN STATE MUSEUM OF FINE ARTS (I,1 1240)
The aim of this study was to obtain a non-destructive three-dimensional model of the ancient Egyptian mummy skeleton from the collection of the Pushkin State Museum of Fine Arts (I,1 1240). The objective of this research was to study the possibility of precise segmentation of bone structures and their separation from the surrounding mummified soft tissues, as well as the reconstruction of destroyed bone fragments according to the preserved shape. With the help of additive technology made all fragments of the skeleton, including the distal phalanx. The digital models and plastic reconstructions of historical artifacts can be used for further research, for example, the biomechanical and morphometric ones, as well as for the purpose of information and education, or as a supplement to the original museum objects
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