442 research outputs found

    The Vela and Geminga pulsars in the mid-infrared

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    The Vela and Geminga pulsars are rotation powered neutron stars, which have been identified in various spectral domains, from the near-infrared to hard γ\gamma-rays. In the near-infrared they exhibit tentative emission excesses, as compared to the optical range. To check whether these features are real, we analysed archival mid-infrared broadband images obtained with the Spitzer Space Telescope in the 3.6--160 μ\mum range and compared them with the data in other spectral domains. In the 3.6 and 5.8 μ\mum bands we detected at \sim (4--5)σ\sigma significance level a point-like object, that is likely to be the counterpart of the Vela pulsar. Its position coincides with the pulsar at < 0.4 arcsec 1σ\sigma-accuracy level. Combining the measured fluxes with the available multiwavelength spectrum of the pulsar shows a steep flux increase towards the infrared, confirming the reality of the near-infrared excess reported early, and, hence, the reality of the suggested mid-infrared pulsar identification. Geminga is also identified, but only at a marginal 2σ\sigma detection level in one 3.6 μ\mum band. This needs a farther confirmation by deeper observations, while the estimated flux is also compatible with the near-infrared Geminga excess. The detection of the infrared excess is in contrast to the Crab pulsar, where it is absent, but is similar to the two magnetars, 4U 0142+61 and 1E 2259+586, showing similar features. We discuss X-ray irradiated fall-back discs around the pulsars, unresolved pulsar nebula structures, and pulsar magnetospheres as possible origins of the excesses. We note also possible infrared signatures of an extended tail behind Geminga and of the Vela plerion radio lobes.Comment: 16 pages, 9 figures, 2 table

    Social and psychological features of inter-cultural adaptation of Russian students in different universities

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    Modern globalisation processes, the rapid entry of Russia into the world community, have given more opportunities to interact with various ethnic groups ranging from short-term tourist and business contacts to complex processes of migration and emigration. Migrants and visitors have different goals for staying in a new country, meanwhile the researchers note a lot in common within the adaptation processes of both groups. In particular, tension, stresses and experience of cultural shock during adaptation are observed. Therefore, it is necessary to conduct psychological studies not only of migrants who come for a long time to a new country, but also of visitors, i.e., interns, students who come to study in foreign universitie

    Study of dose-dependent effect of 2-ethyl-6-methyl-3 hydroxypyridine succinate on the contractile function of isolated rat heat

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    In experiments on the isolated rat heart there were studied the effects of different doses (21.43 mg/kg/day and 85 . 72 mg/kg/day) 2-ethyl-6-methyl-3 hydroxypy ridine succinate ("EkoPharmInvest", Russia), on the contractile function of isolated hearts subjected to prior doxorubicin model (20 mg/kg, intraperitoneal) of pathology. The dynamic of the power mechanisms of ion transport was evaluated by imposing high h eart rate (480 BPM) and increase concentration of Са2+ to 5 mmol in perfusat

    Evaluation of cardioprotective effects of the incritinmimetics exenatideand vildagliptin in the experiment

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    The results of experimental and clinical trials make it clear that incretin mimetics possess pleiotropic effects and demonstrate the value in terms of assessment of their potential opportunities as cardioprotectors. Goals: To study the cardioprotective effects of exenatide and vildagliptin on the model of doxorubicin-induced cardiomyopath

    Effect of multipotent mesenchymal stromal cells secretome on imiquimod-induced psoriasis in rats

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    Multipotent mesenchymal stromal cells secretome contains a range of anti-inflammatory factors and can be used for the treatment of psoriasi

    The G292.0+1.8 pulsar wind nebula in the mid-infrared

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    G292.0+1.8 is a Cas A-like supernova remnant that contains the young pulsar PSR J1124-5916 powering a compact torus-like pulsar wind nebula visible in X-rays. A likely counterpart to the nebula has been detected in the optical VRI bands. To confirm the counterpart candidate nature, we examined archival mid-infrared data obtained with the Spitzer Space Telescope. Broad-band images taken at 4.5, 8, 24, and 70 microns were analyzed and compared with available optical and X-ray data. The extended counterpart candidate is firmly detected in the 4.5 and 8 micron bands. It is brighter and more extended in the bands than in the optical, and its position and morphology agree well with the coordinates and morphology of the torus-like pulsar wind nebula in X-rays. The source is not visible in 24 and 70 micron images, which are dominated by bright emission from the remnant shell and filaments. We compiled the infrared fluxes of the nebula, which probably contains a contribution from an unresolved pulsar in its center, with the optical and X-ray data. The resulting unabsorbed multiwavelength spectrum is described by power laws of significantly steeper slope in the infrared-optical than in X-rays, implying a double-knee spectral break between the optical and X-rays. The 24 and 70 microns flux upper limits suggest a second break and a flatter spectrum at the long wavelength limit. These features are common to two other pulsar wind nebulae associated with the remnants B0540-69.3 and 3C 58 and observed in all three ranges. The position, morphology, and spectral properties of the detected source allow us to comfirm that it is the infrared-optical counterpart to both the pulsar and its wind nebula system in the G292.0+1.8 supernova remnant.Comment: 5 pages, 2 figure

    Experimental approaches to the assessment of potential cardioprotective means with doxorubicin-associated cardiomyopathy

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    Development of methodological approaches for evaluation of cardioprotective activity of drugs in doxorubicin cardiomyopath

    Spectral multiplicity for powers of weakly mixing automorphisms

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    We study the behavior of maximal multiplicities mm(Rn)mm (R^n) for the powers of a weakly mixing automorphism RR. For some special infinite set AA we show the existence of a weakly mixing rank-one automorphism RR such that mm(Rn)=nmm (R^n)=n and mm(Rn+1)=1mm(R^{n+1}) =1 for all nAn\in A. Moreover, the cardinality cardm(Rn)cardm(R^n) of the set of spectral multiplicities for RnR^n is not bounded. We have cardm(Rn+1)=1cardm(R^{n+1})=1 and cardm(Rn)=2m(n)cardm(R^n)=2^{m(n)}, m(n)m(n)\to\infty, nAn\in A. We also construct another weakly mixing automorphism RR with the following properties: mm(Rn)=nmm(R^{n}) =n for n=1,2,3,...,2009,2010n=1,2,3,..., 2009, 2010 but mm(T2011)=1mm(T^{2011}) =1, all powers (Rn)(R^{n}) have homogeneous spectrum, and the set of limit points of the sequence {mm(Rn)n:nN}\{\frac{mm (R^n)}{n} : n\in \N \} is infinite

    Doping awareness among amateur adolescent athletes

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    Objective: to determine the level of awareness of the doping issues among adolescents aged 10–19 years who are engaged in amateur sports as a part of high performance sport.Materials and methods: a special survey of 106 respondents was conducted to assess attitudes towards doping and the level of awareness in anti-doping issues. The average age of the respondents was 17.33 ± 1.54 years.Results: despite the fact that 96 % of the respondents stated that they know what doping is, generally, there is a low level of awareness among young athletes in anti-doping issues. One fourth of the respondents can justify the use of doping, only 13.2 % of adolescents believe that winning a competition with the use of doping can be considered as a well-deserved victory. More than 56 % of the respondents do not warn medical staff that they are athletes, only 32.1 % of adolescents are interested in whether medications prescribed or taken by themselves are included in the prohibited list. The study found that the main sources of information on anti-doping rules for adolescent athletes are television (64.1 %) and specialized websites (47.2 %).Conclusion: the study results revealed the need to popularize information on anti-doping issues. Educational programs should be carried out taking into account the psychological and emotional characteristics of adolescents and include actively promoting doping awareness both using conventional media and new media resources, such as the Internet and social networks
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