272 research outputs found
Clinical manifestations of functionally autonomous cortisol secretion in patients with adrenal masse
The aim of the study was to determine the most significant clinical manifestations of FASC in unoperated AM patients.Цель исследования – определить наиболее значимые клинические проявления ФАСК у неоперированных пациентов с ОН
Evolution in Binary and Triple Stars, with an application to SS Lac
We present equations governing the way in which both the orbit and the
intrinsic spins of stars in a close binary should evolve subject to a number of
perturbing forces, including the effect of a third body in a possibly inclined
wider orbit. We illustrate the solutions in some binary-star and triple-star
situations: tidal friction in a wide but eccentric orbit of a radio pulsar
about a B star, the Darwin and eccentricity instabilities in a more massive but
shorter-period massive X-ray binary, and the interaction of tidal friction with
Kozai cycles in a triple such as Algol (beta-Per), at an early stage in that
star's life when all 3 components were ZAMS stars. We also attempt to model in
some detail the interesting triple system SS Lac, which stopped eclipsing in
about 1950. We find that our model of SS Lac is quite constrained by the
relatively good observational data of this system, and leads to a specific
inclination (29 deg) of the outer orbit relative to the inner orbit at epoch
zero (1912). Although the intrinsic spins of the stars have little effect on
the orbit, the converse is not true: the spin axes can vary their orientation
relative to the close binary by up to 120 deg on a timescale of about a
century.Comment: 30 pages, 6 figure
Specific nature of the integrative (complex) effect of environmental factors on hazelnut cultivars in the Russian humid subtropics
Corylus pontica K. Koch is a valuable nut crop. The expediency of the crop’s large-scale cultivation calls for measuring the parameters of agroclimatic indicators, ranging in variability, intensity, and duration of their impact. Environmental factors were assessed using phenological techniques based on recording the flowering and fruiting dates, recognized as the function demonstrating the complex effect of these factors on the hazelnut yield throughout the crop’s perennial cycle. Climate change urges the selection of adaptable cultivars for such areas where limiting factors are turning into stressors. Dependence of hazel cultivars on climate indicators (air temperature and humidity, and total precipitation) was observed in the phases of harvest formation. The crop’s genotypic diversity contributed to the specific nature of the complex effect produced by environmental factors. Peculiar responses of hazel plants to weather conditions in both flowering and fruiting phases were instigated by the biology of their development. Flowering started in January and depended on air temperature and humidity. Fruiting was affected by air temperatures and precipitation amounts (in July/August). Dependencies between yield and weather were well expressed, with module values of 0.86–1.0 (p < 0.05). The effect size of limiting factors is better measured with the coefficient of determination (%), a direct indicator of the correlations between harvest and weather factors. Flowering (I–III) under unpredictable conditions is regarded as a “critical” stage in the ontogenesis of hazel trees. No less critical is the fruiting phase, occurring simultaneously with the setting and differentiation of generative organs for the next year’s yield. Registration of limiting factors and their variations over the perennial plant cycle made it possible to recommend cvs. ‘Cherkesskiy-2’, ‘Anastasiya’, ‘Kristina’ and ‘Viktoriya’ as adaptable to the subtropics of Krasnodar Territory
The Multiple Origin of Blue Straggler Stars: Theory vs. Observations
In this chapter we review the various suggested channels for the formation
and evolution of blue straggler stars (BSSs) in different environments and
their observational predictions. These include mass transfer during binary
stellar evolution - case A/B/C and D (wind Roche-lobe overflow) mass transfer,
stellar collisions during single and binary encounters in dense stellar
cluster, and coupled dynamical and stellar evolution of triple systems. We also
explore the importance of the BSS and binary dynamics in stellar clusters. We
review the various observed properties of BSSs in different environments (halo
and bulge BSSs, BSSs in globular clusters and BSSs in old open clusters), and
compare the current observations with the theoretical predictions for BSS
formation. We try to constrain the likely progenitors and processes that play a
role in the formation of BSSs and their evolution. We find that multiple
channels of BSS formation are likely to take part in producing the observed
BSSs, and we point out the strengths and weaknesses of each the formation
channel in respect to the observational constraints. Finally we point out
directions to further explore the origin of BSS, and highlight eclipsing binary
BSSs as important observational tool.Comment: Chapter 11, in Ecology of Blue Straggler Stars, H.M.J. Boffin, G.
Carraro & G. Beccari (Eds), Astrophysics and Space Science Library, Springe
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