369 research outputs found
Probing AGN with spectropolarimetry: accretion disk and SMBH parameters
The interaction of a supermassive black hole with the matter of an accretion
disk in the presence of a magnetic field is the key mechanism of energy release
in active galactic nuclei. However, determining the physical parameters of this
system, such as the spin and mass of the black hole, the shape and parameters
of the rotation of the accretion disk, and the geometry of the magnetic field
in the accretion disk is a complex and not completely solved problem. We have
previously shown, based on our numerical models, that these estimates can be
obtained from just three parameters: the black hole mass, bolometric
luminosity, and optical polarization. In this paper, we estimate the accretion
disk and black hole parameters for a sample of 14 type 1 Seyfert galaxies.
Using the spectropolarimetric data obtained by us, we selected only those
objects in which the polarization of optical radiation is generated mainly by
the mechanism in the accretion disk. Despite the small statistics, our results
for such a sample are consistent with our previous conclusions and show a
discrepancy between the disk magnetic field parameters and the classical
Shakura-Sunyaev disk model.Comment: 9 pages, 5 figure
International Transport Corridors of Eurasia and the Silk Road Economic Belt
The paper discusses the interaction of Eurasian Economic Union and the Silk Road Economic Belt within the framework of transport routes and international transport corridors development. Today’s Eurasian international transport corridors are reviewed together with the discussion of rebuild and renovated transport infrastructure, considering corresponding realization issues. The paper gives the perspective of collaboration in the transport section of planned Big Eurasian Partnership, which is virtually realized within the framework of the Shanghai Cooperation Organization
Сross-analysis of big data in accreditation of health specialists
Objective: The relevance of this study is due to the mass accreditation of health professionals that is developing in Russia, which requires innovative measurement tools and opens new opportunities for a well-founded cross-analysis of specialists’ professional readiness quality. Purpose of the study: The purpose of this article is to present approved methodical approaches to the transformation of accreditation data into a format suitable for secondary analysis of medical schools graduates quality based on the requirements of Professional Standards. Method: The leading methods of secondary data analysis are: a) codification of indicators in the primary data accumulation array; b) statistical processing of study results (evaluation of the relationships between the arrays of primary data accumulation and instrumental data, the correlation of test scores obtained by accreditation results with the labor functions of Professional Standards); c) the creation of representative samples for data analysis. The implementation of methods is carried out in the mode of working with arrays of big data, which also uses the method of cross-analysis to identify additional factors that affect to specialists’ professional readiness quality. Results: As a results of the research, there were: 1) approaches to the codification of data in the array and their secondary analysis were developed; 2) three samples were constructed with an estimation of representativeness for different strata, including subjects, assignments and corresponding labor functions; 3) the matrix of primary data in the specialty “Pediatrics” was verified using the example of the results of students from 50 medical universities in Russia. Conclusion: Approbation of methods of secondary data analysis conducted on representative samples of the subjects showed the effectiveness of the developed approaches that should be used when analyzing large data sets in the procedures of certification or accreditation. The materials of the article can be useful for specialists in the field of assessing the quality of education or assessing the professional readiness of health professionals, managers, professors and pedagogical staff of medical schools, specialists of centers for independent assessment of qualifications. © 2018, Modestum Ltd.. All rights reserved
Models of Evaluation of Educational Programs
Описываются различные модели проведения эвалюации образовательных программ. Приводится краткий обзор опыта проведения эвалюации по модели «вход – процесс – выход» в рамках дополнительных профессиональных программThe article describes different models for the evaluation of educational programs. A brief overview of the use «input – process – output» model for the evaluation of additional professional programs is give
Mathematical modeling of the stationary nucleation and crystallization process in super saturated systems with a crystallizer
Local Volume dwarf KK242: radial velocity, SF region, and metallicity
KK242 is a LV dwarf of transition type residing in the void environment. Koda
et al. present clear indications on its connection with Scd galaxy NGC6503.
This implies the distance to KK242 of ~6.3 Mpc and its M_B = -10.5 mag. Its
radial velocity, known from the Effelsberg radio telescope \HI\ observations,
reveals, however, the difference with that of NGC6503, dV ~ 400 km/s. If real,
this fact implies the substantial constraints on its origin. To clear-up the
issue of KK242 radial velocity, we obtained with the SAO 6-m telescope spectra
of its faint star-forming (SF) complex. H-alpha and H-beta emission is detected
in two adjacent compact regions, the southern and northern, separated by ~2"
(~60 pc). Their mean radial velocity is V_hel = -66 km/s, ~100 km/s lower than
that of NGC6503. We use the HST Legacy Archive images and photometry of
individual stars from the Extragalactic Distance Database, available for KK242,
to identify in the SF complex the exciting hot stars, the probable BHeB and
RHeB stars and a supernova remnant. We address, based on the possible range of
its gas metallicity, the probable evolutionary paths of KK242. Using package
Cloudy and parameters of the exciting B0V stars, we conclude that the observed
flux ratio of [Sii] doublet to H-alpha is consistent with the value of
12+log(O/H) ~7.35+/-0.18 dex, expected for a stripped void dIrr galaxy.Comment: 15 pages, 8 figures, 4 tables, published at MNRA
Positioning of subdomain IIId and apical loop of domain II of the hepatitis C IRES on the human 40S ribosome
The 5′-untranslated region of the hepatitis C virus (HCV) RNA contains a highly structured motif called IRES (Internal Ribosome Entry Site) responsible for the cap-independent initiation of the viral RNA translation. At first, the IRES binds to the 40S subunit without any initiation factors so that the initiation AUG codon falls into the P site. Here using an original site-directed cross-linking strategy, we identified 40S subunit components neighboring subdomain IIId, which is critical for HCV IRES binding to the subunit, and apical loop of domain II, which was suggested to contact the 40S subunit from data on cryo-electron microscopy of ribosomal complexes containing the HCV IRES. HCV IRES derivatives that bear a photoactivatable group at nucleotide A275 or at G263 in subdomain IIId cross-link to ribosomal proteins S3a, S14 and S16, and HCV IRES derivatized at the C83 in the apex of domain II cross-link to proteins S14 and S16
Small telescopes being effective: MAGIC or not?
The paper describes the MAGIC multi-mode focal reducer (Monitoring of Active
Galaxies by Investigation of their Cores), commissioned on the 1-m Zeiss-1000
telescope of the Special Astrophysical Observatory of the Russian Academy of
Sciences in September 2020. Three observational modes are currently realised:
photometry, polarimetry, and long-slit spectroscopy. Reducing the focal length
makes it possible to obtain a sufficiently large field of view for photometry
and a large slit height for spectroscopy of 12, as well as a large
field of view for polarimetry with a quadrupole Wollaston prism of
6.4. This feature makes the complex study of extended nebulae and
galaxies efficient. The MAGIC capabilities are presented in examples of
observations of various astronomical objects. The spectral mode in the range of
4000-7200 AA provides the spectral resolution 1000; for a starlike
target up to 14 mag in medium-band filters with a seeing of 1 for 20
minutes of total exposure, the photometry accuracy is better than 0.01 mag and
the polarization accuracy is better than 0.6%. Especially for the new focal
reducer, an offset guide and a position angle rotation system were implemented.
The results of the modernization of the baffle system in the optical scheme of
the telescope for the suppression of scattered light are also described
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