Multi-Periodic Oscillations in Cepheids and RR Lyrae-Type Stars

Classical Cepheids and RR Lyrae-type stars are usually considered to be textbook examples of purely radial, strictly periodic pulsators. Not all the variables, however, conform to this simple picture. In this review I discuss different forms of multi-periodicity observed in Cepheids and RR Lyrae stars, including Blazhko effect and various types of radial and nonradial multi-mode oscillations.Comment: Proceedings of the 20th Stellar Pulsation Conference Series: "Impact of new instrumentation & new insights in stellar pulsations", 5-9 September 2011, Granada, Spai

Kepler photometry of RRc stars: peculiar double-mode pulsations and period doubling

We present the analysis of four first overtone RR Lyrae stars observed with the Kepler space telescope, based on data obtained over nearly 2.5 yr. All four stars are found to be multiperiodic. The strongest secondary mode with frequency f2 has an amplitude of a few mmag, 20–45 times lower than the main radial mode with frequency f1. The two oscillations have a period ratio of P2/P1 = 0.612–0.632 that cannot be reproduced by any two radial modes. Thus, the secondary mode is non-radial. Modes yielding similar period ratios have also recently been discovered in other variables of the RRc and RRd types. These objects form a homogenous group and constitute a new class of multimode RR Lyrae pulsators, analogous to a similar class of multimode classical Cepheids in the Magellanic Clouds. Because a secondary mode with P2/P1 ∼ 0.61 is found in almost every RRc and RRd star observed from space, this form of multiperiodicity must be common. In all four Kepler RRc stars studied, we find subharmonics of f2 at ∼1/2f2 and at ∼3/2f2. This is a signature of period doubling of the secondary oscillation, and is the first detection of period doubling in RRc stars. The amplitudes and phases of f2 and its subharmonics are variable on a time-scale of 10–200 d. The dominant radial mode also shows variations on the same time-scale, but with much smaller amplitude. In three Kepler RRc stars we detect additional periodicities, with amplitudes below 1 mmag, that must correspond to non-radial g-modes. Such modes never before have been observed in RR Lyrae variables

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Рефрактерна нейробластома, перемога над болем (клінічний випадок)

Нейробластома належить до злоякісних пухлин, розвивається зі стовбурових клітин симпатичних гангліїв і мозкової речовини надниркових залоз та входить до групи нейроендокринних пухлин. Частіше локалізується в ділянці надниркових залоз та заочеревинному просторі, значно рідше – в симпатичних вузлах шиї та грудної порожнини. Больовий синдром є одним із провідних проявів у пацієнтів з прогресуванням захворювання. На відміну від інших пацієнтів, у онкологічних хворих больовий синдром не є тимчасовим чи періодичним відчуттям, у ньому немає фізіологічної доцільності, він не має захисного механізму, а навпаки, біль уданої групи хворих призводить до дезадаптації, спотвореного сприйняття больових та небольових імпульсів, а головне – супроводжується різноманітними розладами функцій ЦНС в організмі хворого

Association of haplotypes for SNPs in the LTR regions of bovine leukemia virus with hematological indices of cattle

Molecular typing of BLV samples isolated from Holsteinized Russian Black Pied cattle was carried out, and various cytofluorometric and morphological blood indices were examined. We performed the total count of white blood cells (WBC), lymphocyte (lymf), granulocyte (gran), monocyte (mon), red blood cell (RBC), hemoglobin (HGB), hematocrit (HTC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red blood cell distribution width (RDW), platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and platelet crit count (PCT). The LTR-region of BLV was haplotyped. Only viruses of haplotypes I (0.33±0.03) and III (0.67±0.03) of the eight possible were detected. The ratio of hematologically sick, healthy, and suspected carriers of BLV of haplotypes I and II was comparable with the results of other researchers. The numbers of leukocytes, erythrocytes and platelets in the blood of carriers of haplotype III exceeded the corresponding parameters of cattle affected by the virus of haplotype I. It is interesting to note that the difference in the hemolytic status of animals was manifested not only by the concentration of leukocytes as direct immune agents but also by the count of erythrocytes and platelets, which are not directly involved in the immune response. The number of particles of haplotype III of the BLV circulating in the blood of infected individuals exceeded that of the carriers of haplotype I. In this connection, an assumption was made about the evolutionary advantage of the more virulent haplotype III. However, the results of our own research in conjunction with the data of other scientists indicate that the high virulence of individual virus strains is a consequence of the tendency to implement the maximum possible intensity of the synthesis of virus particles but not of the high damaging effect alone. It is shown that high lethality is evolutionarily disadvantageous for viruses, since the extinction of the carrier as a biological species is fraught with the disappearance of the virus itself

Германістика в транскультурному вимірі: теорія та практика = Germanistik in transkulturellen Raumen: Theorie und Praxis : матеріали XХVІІ Міжнар. наук.-практ. конф. Асоціації українських германістів (25–26 вересня 2020 р.). / редкол. : А. Й. Паславська (голова) [та ін.].

У збірнику вміщено матеріали XХVІІ Міжнародної науково-практичної конференції Асоціації українських германістів, яка відбулася 25–26 вересня 2020 р. у Львівському національному університеті імені Івана Франка. У матеріалах наукової конференції висвітлено актуальні проблеми германської філології, подано результати досліджень у галузях граматики, фразеології, стилістики, дидактики, літературознавства, перекладознавства та міжкультурної комунікації

ВАРІАНТИ СИСТЕМ ТЕХНІЧНОГО ОБСЛУГОВУВАННЯ ПОТОЧНОГО УТРИМАННЯ КОЛІЇ МАШИНІЗОВАНИМИ КОМПЛЕКСАМИ

The alternative choice questions are considered for the track maintenance by the machine complexes under the transition the track keeping of MPS RF to new management and control systems providing the maintenance expences reduction. The transition takes place in accordance with the general administration and management reorganization of railway transport.Рассматриваются вопросы выбора вариантов систем технического обслуживания пути машинизированными комплексами при переходе путевого хозяйства МПС РФ в рамках общей реформы железнодорожного транспорта на новые организационные структуры и системы управления, обеспечивающие снижение эксплуатационных расходов по хозяйству пути.Розглядаються питання вибору варіантів систем технічного обслуговування колії машинізованими комплексами при переході колійного господарства МПС РФ у рамках загальної реформи залізничного транспорту на нові організаційні структури і системи керування, що забезпечують зниження експлуатаційних витрат по колійному господарству

USE OF MOBILE APPLICATIONS IN THE LEARNING PROCESS

Nowadays the interest in integrating mobile applications into the learning process is increasing rapidly, so we need such teaching methods that will facilitate and accelerate the transmission of knowledge to students, intensify the process of learning, teach them techniques for independent work with material, increase productivity of learning and teacher's work. Such teaching methods can be implemented through the use of mobile information technology in education.  Mobile technology can make the learning process more interesting, meeting today's requirements, providing the right information at the right time.&#x0D; The article considers the concept of "mobile learning", analyzes the features and directions of its use in modern education. It is noted that the use of mobile electronic devices and applications in higher mathematics allows you to check quickly the solution, to draw the chart in a few minutes as well as to apply them to distance learning, which greatly facilitates and accelerates knowledge, increases students' productivity and  independent work. It is also noted that despite the widespread use and availability of mobile phones among students, mobile learning is not widespread in native universities. The didactic principles to which mobile applications should correspond are defined, and also the attention to the basic advantages and disadvantages of the use of mobile applications in learning process of higher mathematics is paid.</jats:p

Automated supervised classification of variable stars in the CoRoT programme. Method and application to the first four exoplanet fields

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