Envelope tomography of long-period variable stars: I. The Schwarzschild mechanism and the Balmer emission lines

This paper is the first one in a series devoted to the study of the dynamics of the atmospheres of long-period variable stars. Results from a two-month-long monitoring of the Mira variables RT Cyg and X Oph around maximum light with the ELODIE spectrograph at the Haute-Provence Observatory are presented. The monitoring covers phases 0.80 to 1.16 for RT Cyg and phases 0.83 to 1.04 for X Oph. The cross-correlation profile of the spectrum of RT Cyg with a K0 III mask confirms that the absorption lines of RT Cyg in the optical domain appear double around maximum light. No line doubling was found in the optical spectrum of X Oph around maximum light, indicating that this feature is not common to all long-period variables. This paper also presents the application to RT Cyg of a new tomographic technique deriving the velocity field across the atmosphere by cross-correlating the optical spectrum with numerical masks constructed from synthetic spectra and probing layers of increasing depths. This technique reveals that both the temporal evolution of the line doubling, and its variation with depth in the atmosphere of RT Cyg, are consistent with the ``Schwarzschild scenario''. This scenario relates the temporal evolution of the red and blue peaks of the double absorption lines to the progression of a shock wave in the atmosphere. The temporal evolution of the Balmer Halpha, H beta, Hgamma and Hdelta emission lines around maximum light is also presented for RT Cyg and X Oph. The velocity variations of Halpha and of the absorption lines are discussed in the framework of two competing models for the formation of Balmer emission lines in long-period variable stars.Comment: 11 pages, 8 figures, Latex, accepted for publication in Astronomy and Astrophysics main journal. Also available at http://www-astro.ulb.ac.be/Html/ps.htm

Statistic data simulation at estimation of biological system state

It has been shown by the method of statistic data simulation that using samples of small volume characterizing reference state of biological systems results in overstatement of difficulty degree of state integral estimation. It was stated that using asymptotic integral estimations obtained at unlimited increase of modeling reference sample volume is effective as integral estimation of biological system stat

Проблемы формирования и оценки степени сформированности общекультурных компетенций в условиях новых подходов к образованию

In this article, the author considers problems that universities encounter because of new federal state educational standards that are now taking effect (“third generation” standards). The author raises questions about the necessity of raising emphasis on activities that involve all the students and about development precise assessment tools for measuring the forming of general cultural competences.В работе рассмотрены проблемы, стоящие перед вузами в результате введения в действие федеральных государственных образовательных стандартов (стандартов «третьего» поколения). Автор ставит вопросы об усилении акцента на мероприятия, охватывающие весь контингент студентов с целью формирования общекультурных компетенций, а также о необходимости разработки инструментария оценки степени сформированности общекультурных компетенций

Sinus-preserving modification of eversional carotid endarterectomy: early and late results

Universitatea de Stat de Medicină de Sud Ural, Spitalul Clinic Regional, Celiabinsk, Federația Rusă, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Endarterectomia carotidiană (EAEC) și-a demonstrat avantajul în tratamentul stenozelor hemodinamic semnificative ale arterei carotide interne (ACI). Tehnica prin eversiune este cea mai populară, însă în versiunea sa standard se asociază cu traumatizarea frecventă a sinusului carotidian, cu impact negativ asupra reglării vegetative a tonusului vascular și hemodinamicii. Scopul: Evaluarea eficacității EAEC prin eversiune cu prezervarea nervilor sinusului carotid, comparând rezultatele precoce și la distanță cu cele ale unui lot de control. Material și metode: Studiul a inclus 375 pacienți supuși tratamentului chirurgical în Spitalul Clinic Regional Celiabinsk în perioada anilor 2012-2018. În lotul I (208 bolnavi) EAEC prin eversiune s-a efectuat conform tehnicii standard. În lotul II (167 pacienți) s-a practicat EAEC modificată, cu prezervarea sinusului. Loturile au fost comparabile în funcție de vârstă, gen, statutul neurologic și hipertensiv inițial, utilizarea șuntului temporar, timpul de clampaj al ACI și gradul leziunii arteriale carotidiene contralaterale. Pe lângă înregistrarea parametrilor hemodinamici comuni, a fost evaluată și activitatea vegetativă în baza analizei prospective a variabilității frecvenței cardiace utilizând ritmocardiografia. La etapa de follow-up, parametrii hemodinamici au fost evaluați la 103 pacienți: cu păstrarea nervilor sinusului carotidian (39) și după secționarea acestora (64). Rezultate: În prima zi atât presiunea sistolică, diastolică, cât și presiunea pulsului, precum și frecvența cardiacă au fost mai reduse la bolnavii după EAEC cu prezervarea sinusului în comparație cu lotul de control. În plus, diminuarea influenței simpatice asupra ritmului conform ritmocardiografiei a fost notabilă. La pacienții operați cu prezervarea nervilor sinusului carotidian elevarea tensiunii arteriale s-a atestat mai rar, iar doza necesară de remedii antihipertensive a fost mai mică. Concluzii: S-au constatat diferențe semnificative dintre parametrii, evaluați precoce și la distanță, ai hemodinamicii arteriale postoperatorii și reglării vegetative a tonusului vascular, în funcție de prezervarea nervilor sinusului carotidian. Practicarea EAEC prin eversiune cu prezervarea sinusului carotid reduce riscul complicațiilor postoperatorii cauzate de dereglările vegetative.Introduction: Carotid endarterectomy (CEAE) has proven its advantage in correcting hemodynamically significant stenoses of the internal carotid arteries (ICA). The eversion technique is the most popular, but with its standard procedure, traumatization of carotid sinus nerves occurs, which has a negative effect on the vegetative regulation of vascular tonus and hemodynamics. Aim: To evaluate the effectiveness of eversional CEAE with preservation of carotid sinus nerves, by comparing of early and long-term results with a control group of patients. Materials and methods: The study included 375 patients treated surgically at the Chelyabinsk Regional Clinical Hospital from 2012 to 2018. In the first group (208 patients), eversional CEAE was performed according to standard technique. In the second group (167 patients), a sinus-preserving modification of CEAE was applied. The groups were comparable by age, sex, baseline neurological status, baseline hypertension, use of a temporary shunt, ICA cross-clamping time, and degree of contralateral lesion of the carotid arteries. In addition to common hemodynamic parameters, mediator vegetative activity evaluated based on a prospective analysis of heart rate variability using rhythmocardiography. In the follow-up period, hemodynamic parameters assessed in 103 patients: with preservation of the carotid sinus nerves (39) and after their transection (64). Results: On the 1st day, systolic, diastolic and pulse blood pressure, as well as a heart rate were lower in patients after sinuspreserving CEAE as compared with the control group. In addition, a decrease in sympathetic pressure effect on the rhythm according to rhythmocardiography was noticeable. In patients operated with the preservation of carotid sinus nerves, an increased blood pressure is less common and they require a lower dosage of antihypertensive drugs. Conclusions: There are significant differences between early and distant parameters of postoperative arterial hemodynamics and vegetative regulation of vascular tonus, depending on preservation of the carotid sinus nerves. Practical application of sinus- preserving eversional CEAE reduces the risk of postoperative complications due to vegetative dysregulation

The narrowing of the vocational education space as method and condition of forming of professional competences

The article is devoted to the sources of problems of professionalization. Attention is primarily given to the optimal operating conditions of the learning in natural science and psychology. The main principles of effective learning were discussed. It's contains tutor's work and confidence professional-educational spaceВ статье рассматриваются проблемные вопросы профессионализации, указываются их истоки. Отмечается, что в сфере подготовки специалистов естественно-научного профиля наметился очевидный прогресс в отличие от подготовки гуманитариев в силу специфики гуманитарного знания. Раскрывается значение создания доверительного профессионально-образовательного пространства для формирования профессиональных компетенци

Personal approach as a method and means of promoting professional self the subject of labour

This study examines phenomenon of professional self-determination problems and crisis situation with labour resources in Russia, discusses the problems in psychological consultation. Some types such of problems are marked out. The primary purpose of this study was to describe the personal approach to professional consultation. Author discuss the results with the view that personal approach may serve as a method that increase the effect of professional consultationСтатья посвящена профессиональному самоопределению. Отмечается кризисное состояние трудовых ресурсов в России, недостаточная эффективность работы психологов в области оптимизации профессионального самоопределения, обозначены некоторые ключевые причины этого. В статье предлагается личностный подход, реализуемый через многократные доверительные беседы, как метод и средство участия психологии в профессиональном самоопределении молодеж

Thermal deformation of concentrators in an axisymmetric temperature field

Axisymmetric thermal deformations of paraboloid mirrors, due to heating, are examined for a mirror with a optical axis oriented toward the Sun. A governing differential equation is derived using Mushtari-Donnel-Vlasov simplifications, and a solution is presented which makes it possible to determine the principal deformation characteristics

Understanding the dynamical structure of pulsating stars: The Baade-Wesselink projection factor of the delta Scuti stars AI Vel and beta Cas

Aims. The Baade-Wesselink method of distance determination is based on the oscillations of pulsating stars. The key parameter of this method is the projection factor used to convert the radial velocity into the pulsation velocity. Our analysis was aimed at deriving for the first time the projection factor of delta Scuti stars, using high-resolution spectra of the high-amplitude pulsator AI Vel and of the fast rotator beta Cas. Methods. The geometric component of the projection factor (i.e. p0) was calculated using a limb-darkening model of the intensity distribution for AI Vel, and a fast-rotator model for beta Cas. Then, using SOPHIE/OHP data for beta Cas and HARPS/ESO data for AI Vel, we compared the radial velocity curves of several spectral lines forming at different levels in the atmosphere and derived the velocity gradient associated to the spectral-line-forming regions in the atmosphere of the star. This velocity gradient was used to derive a dynamical projection factor p. Results. We find a flat velocity gradient for both stars and finally p = p0 = 1.44 for AI Vel and p = p0 = 1.41 for beta Cas. By comparing Cepheids and delta Scuti stars, these results bring valuable insights into the dynamical structure of pulsating star atmospheres. They suggest that the period-projection factor relation derived for Cepheids is also applicable to delta Scuti stars pulsating in a dominant radial mode

Electron paramagnetic resonance of Gd3+ ions in Ca1-x-yYxGdyF2+x+y crystals

Electron paramagnetic resonance of Ca1-x-yYxGdyF2+x+y single crystals has revealed spectra that are not typical of gadolinium-doped CaF2 crystals. These spectra have a nearly tetragonal symmetry and are most probably caused by Gd3+ ions localized in yttrium clusters. Weak spectra of tetragonal Gd3+ centers, whose parameters are close to those of a cubic gadolinium center caused by an isolated Gd3+ ion, have been also detected. These centers are attributed to isolated Gd3+ ions localized near octahedral rare-earth clusters or their associations. © 2013 Pleiades Publishing, Ltd