442 research outputs found
The Vela and Geminga pulsars in the mid-infrared
The Vela and Geminga pulsars are rotation powered neutron stars, which have
been identified in various spectral domains, from the near-infrared to hard
-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 m range and compared them with the data in other
spectral domains. In the 3.6 and 5.8 m bands we detected at
(4--5) 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 1-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 2
detection level in one 3.6 m 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
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
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
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
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
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
Development of methodological approaches for evaluation of cardioprotective activity of drugs in doxorubicin cardiomyopath
Spectral multiplicity for powers of weakly mixing automorphisms
We study the behavior of maximal multiplicities for the powers of
a weakly mixing automorphism . For some special infinite set we show the
existence of a weakly mixing rank-one automorphism such that
and for all . Moreover, the cardinality
of the set of spectral multiplicities for is not bounded. We have
and , , . We
also construct another weakly mixing automorphism with the following
properties: for but ,
all powers have homogeneous spectrum, and the set of limit points of
the sequence is infinite
Doping awareness among amateur adolescent athletes
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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