Еволюція рослинного світу в природному і культигенному середовищі

У ході засідань Міжнародної наукової конференції “Еволюція рослинного світу в природному і культигенному середовищі”, присвяченої 200-річчю від Дня народження Чарльза Дарвіна, обговорено актуальні питання еволюційної теорії, ботаніки, фізіології рослин, інтродукції, генетики й селекції, екології, збереження і примноження глобального та локального біорізноманіття, лісових культур і фітомеліорації та інших біологічних наук.В ходе заседаний Международной научной конференции “Эволюция растительного мира в естественной и культигенной среде”, посвященной 200-летию со дня рождения Чарльза Дарвина, обсуждены актуальные вопросы эволюционной теории, ботаники, физиологии растений, интродукции, генетики и селекции, экологии, сохранения и приумножения глобального и локального биоразнообразия, лесных культур и фитомелиорации и других биологических наук.During meetings of the International scientific conference “Evolution of the natural and cultivated plants” to devoted a 200-year from the day of birth of Charles Darwin topical problems of the evolutional theory are discussed, including botany, physiology of plants, introduction of plants, genetics and breeding of plants, ecology, preventing the loss of global and loca biodiversity, arboriculture, forest-growing and other biological sciences

Kepler-22b: A 2.4 Earth-radius Planet in the Habitable Zone of a Sun-like Star

A search of the time-series photometry from NASA's Kepler spacecraft reveals a transiting planet candidate orbiting the 11th magnitude G5 dwarf KIC 10593626 with a period of 290 days. The characteristics of the host star are well constrained by high-resolution spectroscopy combined with an asteroseismic analysis of the Kepler photometry, leading to an estimated mass and radius of 0.970 +/- 0.060 MSun and 0.979 +/- 0.020 RSun. The depth of 492 +/- 10ppm for the three observed transits yields a radius of 2.38 +/- 0.13 REarth for the planet. The system passes a battery of tests for false positives, including reconnaissance spectroscopy, high-resolution imaging, and centroid motion. A full BLENDER analysis provides further validation of the planet interpretation by showing that contamination of the target by an eclipsing system would rarely mimic the observed shape of the transits. The final validation of the planet is provided by 16 radial velocities obtained with HIRES on Keck 1 over a one year span. Although the velocities do not lead to a reliable orbit and mass determination, they are able to constrain the mass to a 3{\sigma} upper limit of 124 MEarth, safely in the regime of planetary masses, thus earning the designation Kepler-22b. The radiative equilibrium temperature is 262K for a planet in Kepler-22b's orbit. Although there is no evidence that Kepler-22b is a rocky planet, it is the first confirmed planet with a measured radius to orbit in the Habitable Zone of any star other than the Sun.Comment: Accepted to Ap

The free energy of NOAA active region AR 11029

The NOAA active region AR 11029 was a small but highly active sunspot region which produced 73 GOES soft X-ray flares. The flares appear to show a departure from the well known power-law frequency-size distribution. Specifically, too few GOES C-class and no M-class flares were observed by comparison with a power-law distribution (Wheatland in Astrophys. J. 710, 1324, 2010). This was conjectured to be due to the region having insufficient magnetic energy to power large events. We construct nonlinear force-free extrapolations of the coronal magnetic field of active region AR 11029 using data taken on 24 October by the SOLIS Vector-SpectroMagnetograph (SOLIS/VSM), and data taken on 27 October by the Hinode Solar Optical Telescope SpectroPolarimeter (Hinode/SP). Force-free modeling with photospheric magnetogram data encounters problems because the magnetogram data are inconsistent with a force-free model, and we employ a recently developed `self-consistency' procedure which addresses this and accommodates uncertainties in the boundary data (Wheatland and Regnier in Astrophys. J. 700, L88, 2009). We calculate the total energy and free energy of the self-consistent solution and find that the free energy was 4x10^29 erg on 24 October, and 7x10^31 erg on 27 October. An order of magnitude scaling between RHESSI non-thermal energy and GOES peak X-ray flux is established from a sample of flares from the literature and is used to estimate flare energies from observed GOES peak X-ray flux. Based on the scaling, we conclude that the estimated free energy of AR 11029 on 27 October when the flaring rate peaked is sufficient to power M-class or X-class flares, and hence the modeling does not appear to support the hypothesis that the absence of large flares is due to the region having limited energy.Comment: Accepted for publication in Solar Physic

The geology and geophysics of Kuiper Belt object (486958) Arrokoth

The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, are primitive objects preserving information about Solar System formation. The New Horizons spacecraft flew past one of these objects, the 36 km long contact binary (486958) Arrokoth (2014 MU69), in January 2019. Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters diameter) within a radius of 8000 km, and has a lightly-cratered smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism

An Observational Overview of Solar Flares

We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

Heparan sulphate, its derivatives and analogues share structural characteristics that can be exploited, particularly in inhibiting microbial attachment

Heparan sulphate (HS) and the related polysaccharide, heparin, exhibit conformational and charge arrangement properties, which provide a degree of redundancy allowing several seemingly distinct sequences to exhibit the same activity. This can also be mimicked by other sulphated polysaccharides, both in overall effect and in the details of interactions and structural consequences of interactions with proteins. Together, these provide a source of active compounds suitable for further development as potential drugs. These polysaccharides also possess considerable size, which bestows upon them an additional useful property: the capability of disrupting processes comprising many individual interactions, such as those characterising the attachment of microbial pathogens to host cells. The range of involvement of HS in microbial attachment is reviewed and examples, which include viral, bacterial and parasitic infections and which, in many cases, are now being investigated as potential targets for intervention, are identified