Cataclysmic Variables from USNO-B1.0 Catalog: Stars with Outbursts on Infrared Palomar Plates

The search was performed for cataclysmic variable stars with outlying infrared magnitudes in USNO-B1.0 catalog. The selection was limited to objects in the Northern hemisphere with (B1-R1) 3.5. The search method is described, and the details on individual stars are given. In total 27 variable objects were found with 20 being the previously known ones and 7 - new discoveries. 4 of newly found variables are dwarf novae, while the remaining 3 - pulsating red variables of Mira or semi-regular types, including a heavily reddened one in Pelican nebula. The correct pulsation period is determined for two stars discovered by other researchers, and the dwarf nova nature is confirmed for another object previously suspected as such. The perspectives of the proposed search technique in the framework of Virtual Observatory are also discussed.Comment: 8 pages, 10 figures, submitted to Astronomy Letter

Identification of new cataclysmic variables in the 1RXS and USNO-B1.0 catalogs

As a result of applying the original optical variability search method on publicly available data, we have found eight new cataclysmic variables and two possible Optically Violent Variable quasars among the previously unidentified X-ray sources in the ROSAT catalog. We describe the search method and present the characteristics of the newly identified variable stars. The obtained results demonstrate the large potential of the concept of Virtual Observatory for identifying new objects of astrophysical interest.Comment: 16 pages, 11 figures, 2 tables; submitted to Astronomy Letter

Calculation of the inductive resistance of the phase of the anker winding of the sup-exciter of the combined multifunctional brushless exciter

In this paper, the picture of the magnetic field of scattering and mutual induction of the anker winding of the sup-exciter for the three types of configuration of the tooth-groove layer is considered.. The inductive resistance of scattering and mutual induction for the entire phase is calculated.В данной статье рассмотрена картина магнитного поля рассеяния и взаимоиндукции якорной обмотки подвозбудителя для трёх типов конфигурации зубцово-пазового слоя. Рассчитано индуктивное сопротивление рассеяния и взаимоиндукции для всей фазы

Muon pair creation from positronium in a circularly polarized laser field

We study elementary particle reactions that result from the interaction of an atomic system with a very intense laser wave of circular polarization. As a specific example, we calculate the rate for the laser-driven reaction $e^+e^- \to \mu^+\mu^-$, where the electron and positron originate from a positronium atom or, alternatively, from a nonrelativistic $e^+e^-$ plasma. We distinguish accordingly between the coherent and incoherent channels of the process. Apart from numerical calculations, we derive by analytical means compact formulas for the corresponding reaction rates. The rate for the coherent channel in a laser field of circular polarization is shown to be damped because of the destructive interference of the partial waves that constitute the positronium ground-state wave packet. Conditions for the observation of the process via the dominant incoherent channel in a circularly polarized field are pointed out

Measurement of the Beam Asymmetry Sigma and the Target Asymmetry T in the Photoproduction of Omega Mesons off the Proton Using CLAS at Jefferson Laboratory

The photoproduction of omega mesons off the proton has been studied in the reaction γp -\u3e pω using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target in Hall B at the Thomas Jefferson National Accelerator Facility. For the first time, the target asymmetry T has been measured in photoproduction from the decay ω -\u3e π+π-π0, using a transversely polarized target with energies ranging from just above the reaction threshold up to 2.8 GeV. Significant nonzero values are observed for these asymmetries, reaching about 30-40% in the third-resonance region. New measurements for the photon-beam asymmetry Σ are also presented, which agree well with previous CLAS results and extend the world database up to 2.1 GeV. These data and additional ω photoproduction observables from CLAS were included in a partial-wave analysis within the Bonn-Gatchina framework. Significant contributions from s-channel resonance production were found in addition to t-channel exchange processes

Discovery of an unusual bright eclipsing binary with the longest known period: TYC 2505-672-1 / MASTER OT J095310.04+335352.8

We report on the MASTER Global Robotic Net discovery of an eclipsing binary, MASTER OT J095310.04+335352.8, previously known as unremarkable star TYC 2505-672-1, which displays extreme orbital parameters. The orbital period P=69.1 yr is more than 2.5 times longer than that of epsilon-Aurigae, which is the previous record holder. The light curve is characterized by an extremely deep total eclipse with a depth of more than 4.5 mag, which is symmetrically shaped and has a total duration of 3.5 yrs. The eclipse is essentially gray. The spectra acquired with the Russian 6 m BTA telescope both at minimum and maximum light mainly correspond to an M0-1III--type red giant, but the spectra taken at the bottom of eclipse show small traces of a sufficiently hot source. The observed properties of this system can be better explained as the red giant eclipsed by a large cloud (the disk) of small particles surrounding the invisible secondary companion.Comment: 8 figures, 9 pages, Astronomy and astrophysics in prin

Optical polarization observations with the MASTER robotic net

We present results of optical polarization observations performed with the MASTER robotic net for three types of objects: gamma-ray bursts, supernovae, and blazars. For the Swift gamma-ray bursts GRB100906A, GRB110422A, GRB121011A, polarization observations were obtained during very early stages of optical emission. For GRB100906A it was the first prompt optical polarization observation in the world. Photometry in polarizers is presented for Type Ia Supernova 2012bh during 20 days, starting on March 27, 2012. We find that the linear polarization of SN 2012bh at the early stage of the envelope expansion was less than 3%. Polarization measurements for the blazars OC 457, 3C 454.3, QSO B1215+303, 87GB 165943.2+395846 at single nights are presented. We infer the degree of the linear polarization and polarization angle. The blazars OC 457 and 3C 454.3 were observed during their periods of activity. The results show that MASTER is able to measure substantially polarized light; at the same time it is not suitable for determining weak polarization (less than 5%) of dim objects (fainter than 16$^m$). Polarimetric observations of the optical emission from gamma-ray bursts and supernovae are necessary to investigate the nature of these transient objects.Comment: 31 pages, 12 figures, 4 tables; Exposure times in Table 2 have been correcte

Methodical approaches in experimental modelling of non-alcoholic fatty liver disease

The aim of review. To generalize literature data on ways of non-alcoholic fatty liver disease (NAFLD) modelling in experimental animals, to reveal advantages of various techniques, to present results of original studies on diet-induced NAFLD at rats.Key points. Data of the literature and author’s original data on experimental NAFLD modelling are presented. Today‘s methods of NAFLD modelling can be divided into two extensive groups: induction of liver disease by genetic mutation, and phenotypic development of NAFLD due to alimentary factor. Genetic models are subdivided into two categories. In the first the liver of laboratory animals is the main pathogenic target, metabolic disorders develop insignificantly (lines of animals with of Acetyl-CoA oxidase gene deletion, knockoutmice for methionine-adenosyl transferases-1А gene and animals with deleted specific hepatic phosphatase and tensin homologue gene). Genetic models of NAFLD developing on background of obesity and metabolicsyndrome represent the second category (animals, with leptin gene deletion – ob/ob, mice resistant to leptin action, – db/db and transgenic mice with excessive expression of styrene-regulating element of protein-1 isoform. Diet-induced models of NAFLD are engendered by modulation of various alimentary factors. They include methionine choline-deficient diet, fructoseenriched diet and various variations of high-fat diet. At diet-induced NAFLD the liver undergoes a complex of histological and metabolic disorders to the high extent close to clinical symptoms of this disease in humans.Conclusion. There is a set of various ways of NAFLD modelling in animals. Numerous methods can be used for confirmation or refutation of NAFLD pathogenesis hypotheses. It is necessary to choose the optimal way of NAFLD modelling, allowing to reveal certain part of pathologic mechanisms of disease and to determine strategy of hepatotropic treatment according to determined task

Polyunsaturated fatty acid status of leukocyte membranes in COPD patients

The aim of the study was to analyze n-3 and n-6 polyunsaturated fatty acid (PUFA) profile of blood leukocyte cytomembranes in mild and moderate COPD, and to establish possible role of these fatty acids in COPD progression. The study involved 110 patients with mild disease (n = 60) and moderate COPD (50 patients), at average age of 57.5±4.8 years old. The control group consisted of 32 practically healthy non-smoking people with normal pulmonary function (average age 42.0±3.4 years). The immunological study included flow cytometric determination of blood immune cell subpopulations, i.e., T lymphocytes (CD3+), T helper cells (CD4+), cytotoxic T lymphocytes (CD8+), and B cells (CD19+) using Becton Dickinson machine (USA). Fatty acid methyl esters redissolved in hexane were analyzed using “Shimadzu GC-2010” gas-liquid chromato-graphic system (Japan). Analysis of the polyunsaturated fatty acid profile of leukocyte membranes in COPD patients revealed a reduced concentration of essential linoleic acid (18:2n-6) regardless of the disease severity. The leukocyte membrane levels of the long-chain n-6 PUFAs, such as dihomo-γ-linolenic acid (20:3n-6), arachidonic acid (20:4n-6), and docosatetraenoic acid (22:4n-6), were elevated in patients with COPD compared with the control group. However, the concentration of the described above n-6 PUFAs in leukocyte membranes was increased in patients with moderate COPD compared to the patients with mild COPD. The significant deficiency of a physiologically important n-3 PUFA, eicosapentaenoic acid (20:5n- 3), in leukocyte membranes in the COPD patients was revealed. In turn, the low level of 20:5n-3 could result from the deficiency of its precursor, docosahexaenoic acid (22:6n-3). The results of the study indicate the modification in the PUFA composition of blood leukocyte membranes in the patients with COPD. It was shown that altered composition of long-chain fatty acid of leukocyte membranes emerges already at the early stage of the disease. Therefore, the imbalance in fatty acids composition of leukocytes makes a significant contribution to the development and the progression of COPD