The relation between gas density and velocity power spectra in galaxy clusters: qualitative treatment and cosmological simulations

We address the problem of evaluating the power spectrum of the velocity field of the ICM using only information on the plasma density fluctuations, which can be measured today by Chandra and XMM-Newton observatories. We argue that for relaxed clusters there is a linear relation between the rms density and velocity fluctuations across a range of scales, from the largest ones, where motions are dominated by buoyancy, down to small, turbulent scales: $(\delta\rho_k/\rho)^2 = \eta_1^2 (V_{1,k}/c_s)^2$, where $\delta\rho_k/\rho$ is the spectral amplitude of the density perturbations at wave number $k$, $V_{1,k}^2=V_k^2/3$ is the mean square component of the velocity field, $c_s$ is the sound speed, and $\eta_1$ is a dimensionless constant of order unity. Using cosmological simulations of relaxed galaxy clusters, we calibrate this relation and find $\eta_1\approx 1 \pm 0.3$. We argue that this value is set at large scales by buoyancy physics, while at small scales the density and velocity power spectra are proportional because the former are a passive scalar advected by the latter. This opens an interesting possibility to use gas density power spectra as a proxy for the velocity power spectra in relaxed clusters, across a wide range of scales.Comment: 6 pages, 3 figures, submitted to ApJ Letter

X-ray line formation in the spectrum of SS 433

The mechanisms for the formation of X-ray lines in the spectrum of SS 433 are investigated by taking into account the radiative transfer inside the jets. The results of Monte Carlo numerical simulations are presented. The effect of a decrease in line intensity due to scattering inside the jet turns out to be pronounced, but it does not exceed 60% in magnitude on the entire grid of parameters. The line broadening due to scattering, nutational motion, and the contribution of satellites can lead to overestimates of the jet opening angle $\Theta$ from the line widths in Chandra X-ray observations. The fine structure of the lines turns out to be very sensitive to the scattering effects. This makes its investigation by planned X-ray observatories equipped with high-resolution spectrometers (primarily Astro-H) a powerful tool for diagnosing the parameters of the jets in SS 433.Comment: 23 pages, 14 figures, to be published in Astronomy Letters, v. 38, n. 7, p. 443 (2012

Complex experiment on studying the microphysical, chemical, and optical properties of aerosol particles and estimating the contribution of atmospheric aerosol-to-earth radiation budget

The primary objective of this complex aerosol experiment was the measurement of microphysical, chemical, and optical properties of aerosol particles in the surface air layer and free atmosphere. The measurement data were used to retrieve the whole set of aerosol optical parameters, necessary for radiation calculations. Three measurement cycles were performed within the experiment during 2013: in spring, when the aerosol generation is maximal; in summer (July), when atmospheric boundary layer altitude and, hence, mixing layer altitude are maximal; and in late summer/early autumn, during the period of nucleation of secondary particles. Thus, independently obtained data on the optical, meteorological, and microphysical parameters of the atmosphere allow intercalibration and inter-complement of the data and thereby provide for qualitatively new information which explains the physical nature of the processes that form the vertical structure of the aerosol field

Pressure effect on magnetic susceptibility of LaCoO3_3

The effect of pressure on magnetic properties of LaCoO$_3$ is studied experimentally and theoretically. The pressure dependence of magnetic susceptibility $\chi$ of LaCoO$_3$ is obtained by precise measurements of $\chi$ as a function of the hydrostatic pressure $P$ up to 2 kbar in the temperature range from 78 K to 300 K. A pronounced magnitude of the pressure effect is found to be negative in sign and strongly temperature dependent. The obtained experimental data are analysed by using a two-level model and DFT+U calculations of the electronic structure of LaCoO$_3$. In particular, the fixed spin moment method was employed to obtain a volume dependence of the total energy difference $\Delta$ between the low spin and the intermediate spin states of LaCoO$_3$. Analysis of the obtained experimental $\chi(P)$ dependence within the two-level model, as well as our DFT+U calculations, have revealed the anomalous large decrease in the energy difference $\Delta$ with increasing of the unit cell volume. This effect, taking into account a thermal expansion, can be responsible for the temperatures dependence of $\Delta$, predicting its vanishing near room temperature.Comment: 7 pages, 9 figure

Allergy to peanuts and nuts: who, why and for how long?

The aim of the study - to study the history of life and clinical symptoms of the disease in children with a history of food anaphylaxis for peanuts and nuts.Цель исследования – изучить анамнез жизни и клинические симптомы болезни у детей с пищевой анафилаксией на арахис и орехи в анамнезе

Effect of dapagliflozin therapy on achieving cardiovascular mortality target indicators in patients with heart failure

Aim. To assess the effect of therapy with sodium glucose co-transporter type 2 inhibitor dapagliflozin in patients with heart failure with reduced ejection fraction (CHrEF) on the state cardiovascular mortality target indicators.Material and methods. All adult Russian patients with NYHA class II-IV HFrEF (left ventricular ejection fraction ≤40%) were considered as the target population. The characteristics of patients in the study corresponded to those in the Russian Hospital HF Registry (RUS-HFR). The study suggests that the use of dapagliflozin in addition to standard therapy will be expanded by 10% of the patient population annually in 2022-24. Cardiovascular mortality modeling was performed based on the extrapolation of DAPA-HF study result. The number of deaths that can be prevented was calculated when using dapagliflozin in addition to standard therapy. Further, the contribution of prevented deaths with dapagliflozin therapy to the achievement of federal and regional cardiovascular mortality target indicators (1, 2 and 3 years) was calculated.Results. The use of dapagliflozin in addition to standard therapy for patients with NYHA class II-IV CHrEF with the expansion of dapagliflozin therapy by 10% of the patient population annually will additionally prevent 1729 cardiovascular death in the first year. This will ensure the implementation of cardiovascular mortality target indicators in Russia in 2022 by 11,8%. In the second year, 3769 cardiovascular deaths will be prevented, which will ensure the implementation of target indicators in 2023 by 17,2%. In the third year, 5465 cardiovascular deaths prevented, which will ensure the implementation of implementation of target indicators in 2024 by 18,7%.Conclusion. The use of dapagliflozin in addition to standard therapy for patients with NYHA class II-IV CHrEF will ensure the implementation of implementation of target indicators in 2024 by 18,7%

Formalization of sustainable innovative development process in the model of innovations diffusion

© 2016, Econjournals. All rights reseved. The relevance of the study is reasoned by the fact that the sustainability of innovative development cannot be fully estimated by using the parameters which are traditionally observed by the official statistical bodies, so it suggests the need to improve methodological solutions and technology economic interpretation as well as scaling of indicators’ values in this field. At the macro level there is a small number of indicators on the basis of which we can conclude about the stability of innovative development of economic systems at the meso-and macro level. In this regard, this article aims to formalize the process of sustainable innovation development on the basis of the parameters’ set formation of the innovations’ diffusion model and diagnosis of major economic systems’ development level. The leading method is the parameters’ set formalization of the quantitative model to estimate the level of economic systems’ innovative development based on managerial interpretation of descriptive statistics’ indicators of innovation activity in the framework of economic activities. Aset of quantitative parameters of 9 parametric model of economic systems’ innovative development level is formalized in the article, allowing to diagnose the impact of cyclical factors and the institutional environment that are not fully implemented in the existing macro- systems assessing the level of economic systems’ innovative development; methods of diagnosis and economic interpretation of the relevant indices and indicators’ levels are proposed. The material of this paper is of practical value for enterprises’ innovative activities regulators and monitoring agencies, for regional innovation infrastructure and transfer technology entities, for innovation-active enterprises, because on the basis of the obtained model the optimal solutions in the development of strategies for the upgrading of industries, regions, macro-economic system as a whole are possible

СТ- perfusion possibilities in evaluation brain gliomas combined and complex treatment results

Today, neuroperfusion is one of the actively developed and researched techniques in the annex to the MRI, and to the CT examination. If the advisability of its use for the assessment of ischemic changes in the brain has no one in doubt, the application of this technique in neurooncology still under investigation. For many clinicians necessity of use this method in diagnostic algorithms remains controversial and questionable. In this article we want to share our experiences in use of CT-perfusion during monitoring the results of combined treatment of glial brain tumors.Нейроперфузия является одной из активно развиваемых и исследуемых методик как в приложении к МРТ, так и к компьютерной томографии. Если целесообразность ее использования для оценки ишемических изменения головного мозга не вызывает сомнения, то применение этой методики в нейроонкологии еще находится в стадии изучения. Для многих клиницистов необходимость использования перфузионной КТ в диагностических алгоритмах остается спорной и сомнительной. В статье представлен наш опытом использования перфузионной КТ в мониторинге результатов комбинированного лечения глиальных опухолей головного мозга