Leader in Politics and Governance: Russian Aspect

The paper analyzes the nature of the political leader's image; interaction of the political leader with different faces, sides and aspects of political life is considered; distinctness of its manifestations is identified. Analysis of the political leader's image formation, comparison of models and comparative analysis of political leaders’ characters are made with reference of Russia

Plasma 2020 - Intracluster Medium Plasmas

Galaxy clusters are the largest and most massive bound objects resulting from cosmic hierarchical structure formation. Baryons account for somewhat more than 10% of that mass, with roughly 90% of the baryonic matter distributed throughout the clusters as hot ($T>1$ keV), high-$\beta$, very weakly collisional plasma; the so-called "intracluster medium" (ICM). Cluster mergers, close gravitational encounters and accretion, along with violent feedback from galaxies and relativistic jets from active galactic nuclei, drive winds, gravity waves, turbulence and shocks within the ICM. Those dynamics, in turn, generate cluster-scale magnetic fields and accelerate and mediate the transport of high-energy charged particles. Kinetic-scale, collective plasma processes define the basic character and fundamental signatures of these ICM phenomena, which are observed primarily by X-ray and radio astronomers.Comment: 5 pages, 2 figures, submitted for the 2020 Decadal Assessment of Plasma Scienc

Deep Chandra Observations of Abell 2199: the Interplay between Merger-Induced Gas Motions and Nuclear Outbursts in a Cool Core Cluster

We present new Chandra observations of Abell 2199 that show evidence of gas sloshing due to a minor merger, as well as impacts of the radio source, 3C 338, hosted by the central galaxy, NGC 6166, on the intracluster gas. The new data are consistent with previous evidence of a Mach 1.46 shock 100" from the cluster center, although there is still no convincing evidence for the expected temperature jump. Other interpretations of this feature are possible, but none is fully satisfactory. Large scale asymmetries, including enhanced X-ray emission 200" southwest of the cluster center and a plume of low entropy, enriched gas reaching 50" to the north of the center, are signatures of gas sloshing induced by core passage of a merging subcluster about 400 Myr ago. An association between the unusual radio ridge and low entropy gas are consistent with this feature being the remnant of a former radio jet that was swept away from the AGN by gas sloshing. A large discrepancy between the energy required to produce the 100" shock and the enthalpy of the outer radio lobes of 3C 338 suggests that the lobes were formed by a more recent, less powerful radio outburst. Lack of evidence for shocks in the central 10" indicates that the power of the jet now is some two orders of magnitude smaller than when the 100" shock was formed.Comment: 17 pages, 20 figures, accepted for publication in Ap

Physics of cosmic plasmas from high angular resolution X-ray imaging of galaxy clusters

Galaxy clusters are massive dark matter-dominated systems filled with X-ray emitting, optically thin plasma. Their large size and relative simplicity (at least as astrophysical objects go) make them a unique laboratory to measure some of the interesting plasma properties that are inaccessible by other means but fundamentally important for understanding and modeling many astrophysical phenomena -- from solar flares to black hole accretion to galaxy formation and the emergence of the cosmological Large Scale Structure. While every cluster astrophysicist is eagerly anticipating the direct gas velocity measurements from the forthcoming microcalorimeters onboard XRISM, Athena and future missions such as Lynx, a number of those plasma properties can best be probed by high-resolution X-ray imaging of galaxy clusters. Chandra has obtained some trailblazing results, but only grazed the surface of such studies. In this white paper, we discuss why we need arcsecond-resolution, high collecting area, low relative background X-ray imagers (with modest spectral resolution), such as the proposed AXIS and the imaging detector of Lynx.Comment: Science white paper submitted for Astro2020 Decadal survey. 9 pages, 4 figure

The Quiescent Intracluster Medium in the Core of the Perseus Cluster

Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host of astrophysical processes. Knowledge of the dynamics of the pervasive hot gas, which dominates in mass over stars in a cluster, is a crucial missing ingredient. It can enable new insights into mechanical energy injection by the central supermassive black hole and the use of hydrostatic equilibrium for the determination of cluster masses. X-rays from the core of the Perseus cluster are emitted by the 50 million K diffuse hot plasma filling its gravitational potential well. The Active Galactic Nucleus of the central galaxy NGC1275 is pumping jetted energy into the surrounding intracluster medium, creating buoyant bubbles filled with relativistic plasma. These likely induce motions in the intracluster medium and heat the inner gas preventing runaway radiative cooling; a process known as Active Galactic Nucleus Feedback. Here we report on Hitomi X-ray observations of the Perseus cluster core, which reveal a remarkably quiescent atmosphere where the gas has a line-of-sight velocity dispersion of 164+/-10 km/s in a region 30-60 kpc from the central nucleus. A gradient in the line-of-sight velocity of 150+/-70 km/s is found across the 60 kpc image of the cluster core. Turbulent pressure support in the gas is 4% or less of the thermodynamic pressure, with large scale shear at most doubling that estimate. We infer that total cluster masses determined from hydrostatic equilibrium in the central regions need little correction for turbulent pressure.Comment: 31 pages, 11 Figs, published in Nature July

Hitomi (ASTRO-H) X-ray Astronomy Satellite

The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E  >  2  keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month

Hitomi X-Ray Studies of Giant Radio Pulses from the Crab Pulsar

To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satellite Hitomi in the 2300 keV band and the Kashima NICT radio telescope in the 1.41.7 GHz band with a net exposure of about 2 ks on 2016 March 25, just before the loss of the Hitomi mission. The timing performance of the Hitomi instruments was confirmed to meet the timing requirement and about 1000 and 100 GRPs were simultaneously observed at the main pulse and inter-pulse phases, respectively, and we found no apparent correlation between the giant radio pulses and the X-ray emission in either the main pulse or inter-pulse phase. All variations are within the 2 fluctuations of the X-ray fluxes at the pulse peaks, and the 3 upper limits of variations of main pulse or inter-pulse GRPs are 22% or 80% of the peak flux in a 0.20 phase width, respectively, in the 2300 keV band. The values for main pulse or inter-pulse GRPs become 25% or 110%, respectively, when the phase width is restricted to the 0.03 phase. Among the upper limits from the Hitomi satellite, those in the 4.510 keV and 70300 keV bands are obtained for the first time, and those in other bands are consistent with previous reports. Numerically, the upper limits of the main pulse and inter-pulse GRPs in the 0.20 phase width are about (2.4 and 9.3) 10(exp 11) erg cm(exp 2), respectively. No significant variability in pulse profiles implies that the GRPs originated from a local place within the magnetosphere. Although the number of photon-emitting particles should temporarily increase to account for the brightening of the radio emission, the results do not statistically rule out variations correlated with the GRPs, because the possible X-ray enhancement may appear due to a >0.02% brightening of the pulse-peak flux under such conditions

Клинико-генетические аспекты менопаузальной гормональной терапии - современная парадигма. Что изменила пандемия COVID-19?

In the modern paradigm of public health protection, much attention is paid to the health of women in peri- and postmenopause, and a personalized approach prevails. It is generally recognized that the pathogenetic therapy of menopausal disorders is hormone therapy. But the COVID-19 pandemic has made its own adjustments to the routine strategy of choosing menopausal hormone therapy (MHT). The purpose of this review was to analyze studies on the dependence of the effectiveness of MHT on clinical and genetic aspects in the context of the ongoing COVID-19 pandemic. The review highlights the main risks of MHT for thromboembolic diseases and coagulation complications characteristic of COVID-19, discusses genetic predispositions that aggravate the course of the post-COVID period, as well as the effectiveness of estrogens in protecting the vascular endothelium and increasing the number of CD4+ T cells, providing an adequate immune response when infected with SARS-CoV-2. Numerous studies show that the complications characteristic of the severe course of COVID-19 are multifactorial in nature and cannot be unambiguously explained only by genetic predisposition. However, with the development of personalized medicine, special attention should be paid to the study of genetic aspects that can equally contribute to the occurrence of menopausal disorders in healthy women and aggravate the course of the post-pregnancy period. The data presented allow us to conclude that in the context of the ongoing COVID-19 pandemic at the population level, MHT can bring significant benefits to women during menopause due to the beneficial effect of estrogens on vascular walls. Additional study of the relationship between the course of the postcovid period in MHT users and polymorphisms of candidate genes that determine the risks of thrombotic complications and metabolic consequences is required.В современной парадигме охраны здоровья населения здоровью женщин в пери- и постменопаузе уделяется большое внимание, причем господствует персонифицированный подход. Общепризнанно, что патогенетической терапией менопаузальных расстройств является гормональная терапия. Но пандемия COVID-19 внесла свои коррективы в рутинную стратегию выбора менопаузальной гормональной терапии (МГТ). Целью данного обзора являлся анализ исследований зависимости эффективности МГТ от клинико-генетических аспектов в условиях продолжающейся пандемии COVID-19. В обзоре выделяются основные риски МГТ тромбоэмболических заболеваний и коагуляционных осложнений, характерных для COVID-19, обсуждаются генетические предрасположенности, отягчающие течение постковидного периода, а также эффективность эстрогеныов, защищающих эндотелий сосудов и увеличивающих количество CD4+ T-клеток, обеспечивая адекватный иммунный ответ при инфицировании SARS-CoV-2. Многочисленные исследования показывают, что осложнения, характерные для тяжелого течения COVID-19, носят многофакторный характер и не могут быть однозначно объяснены только генетической предрасположенностью. Однако, с развитием персонализированной медицины, особого внимания заслуживает исследование генетических аспектов, которые могут в равной мере способствовать возникновению менопаузальных расстройств у здоровых женщин и отягощать течение постковидного периода. Приведенные данные позволяют сделать вывод, что в условиях продолжающейся пандемии COVID-19 на популяционном уровне МГТ может принести существенную выгоду женщинам в период климактерия за счет благоприятного влияния эстрогенов на стенки сосудов. Требуется дополнительное изучение взаимосвязи течения постковидного периода у пользовательниц МГТ и полиморфизмов генов-кандидатов, определяющих риски тромботических осложнений и метаболических последствий