Black Hole Formation in X-Ray Binaries: The Case of XTE J1118+480

In recent years, an increasing number of proper motions have been measured for Galactic X-ray binaries. When supplemented with accurate determinations of the component masses, orbital period, and donor luminosity and effective temperature, these kinematical constraints harbor a wealth of information on the systems' past evolution. The constraints on compact object progenitors and kicks derived from this are of immense value for understanding compact object formation and exposing common threads and fundamental differences between black hole and neutron star formation. Here, we present the results of such an analysis for the black hole X-ray binary XTE J1118+480. We present results from modeling the mass transfer phase, following the motion in the Galaxy back to the birth site of the black hole, and examining the dynamics of symmetric and asymmetric core-collapses of the black hole progenitor

Eccentric double white dwarfs as LISA sources in globular clusters

We consider the formation of double white dwarfs (DWDs) through dynamical interactions in globular clusters. Such interactions can give rise to eccentric DWDs, in contrast to the exclusively circular population expected to form in the Galactic disk. We show that for a 5-year Laser Interferometer Space Antenna (LISA) mission and distances as far as the Large Magellanic Cloud, multiple harmonics from eccentric DWDs can be detected at a signal-to-noise ratio higher than 8 for at least a handful of eccentric DWDs, given their formation rate and typical lifetimes estimated from current cluster simulations. Consequently the association of eccentricity with stellar-mass LISA sources does not uniquely involve neutron stars, as is usually assumed. Due to the difficulty of detecting (eccentric) DWDs with present and planned electromagnetic observatories, LISA could provide unique dynamical identifications of these systems in globular clusters.Comment: Published in ApJ 665, L5

Why didn’t Russia become a constitutional monarchy in the XIX century?

The article deals with the main problems associated with the possibility of implementing a constitutional alternative in Russia in the XIX century. The authors consider the prerequisites for the development of constitutional projects during this period, including their regularity or randomness, and relationship with previous stages of development of the Russian statehood. They pay particular attention to the subjective factor, i.e. personal views and worldview of the Russian emperors as the main condition for the implementation of the constitutional alternative to the development of the country. The reigns of Alexander I and Alexander II, who were either the initiators of the development of constitutional projects (Alexander I) or did not prevent it (Alexander II), are the focus of attention. The comparative analysis of the main constitutional projects of the XIX century is carried out in this article: of the Letter of Commendation to the Russian people in 1801, the project of M.M. Speransky in 1809, the Charter Diploma of the Russian Empire in 1818-1820, the project of P.A. Valuev in 1863, the grand prince Konstantin Nikolaevich in 1866 and 1880, the P.A. Shuvalov in 1874 and of the M.T. Loris-Melikov in 1880-1881.The projects of the time period of Alexander II are much more moderate than of the epoch of Alexander I and they can be recognized as constitutional ones with a great stretch. It was a step backwards in the development of Russian constitutionalism. This is explained by a subjective factor: much more moderate political views of Alexander II and his greater commitment to the autocratic tradition inherited from his father. In conclusion, there are the reasons for the lack of implementation of the constitutional alternative in Russia in the XIX century in this article, they are the following: peculiarities of the social structure of the Russian society, narrowness of the social base of the constitutional reforms, lack of understanding and disinterestedness of the majority of the population in their implementation and necessity, indecision of the emperors

Supernova Ia: a Converging Delayed Detonation Wave

A model of a carbon-oxygen (C--O) presupernova core with an initial mass 1.33 M_\odot, an initial carbon mass fraction 0.27, and with an average mass growth-rate 5 x 10^{-7} M_\odot/yr due to accretion in a binary system was evolved from initial central density 10^9 g/cm^3, and temperature 2.05 x 10^8 K through convective core formation and its subsequent expansion to the carbon runaway at the center. The only thermonuclear reaction contained in the equations of evolution and runaway was the carbon burning reaction 12C + 12C with an energy release corresponding to the full transition of carbon and oxygen (with the same rate as carbon) into 56Ni. As a parameter we take \alpha_c - a ratio of a mixing length to the size of the convective zone. In spite of the crude assumptions, we obtained a pattern of the runaway acceptable for the supernova theory with the strong dependence of its duration on \alpha_c. In the variants with large enough values of \alpha_c=4.0 x 10^{-3} and 3.0 x 10^{-3} the fuel combustion occurred from the very beginning as a prompt detonation. In the range of 2.0 x 10^{-3} >= \alpha_c >= 3.0 x 10^{-4} the burning started as a deflagration with excitation of stellar pulsations with growing amplitude. Eventually, the detonation set in, which was activated near the surface layers of the presupernova (with m about 1.33 M_\odot) and penetrated into the star down to the deflagration front. Excitation of model pulsations and formation of a detonation front are described in detail for the variant with \alpha_c=1.0 x 10^{-3}.Comment: 13 pages, 11 figures, to appear in Astronomy Letter

Evaluation of a school based comprehensive sexuality education program among very young adolescents in rural Uganda

Background: Limited research has been conducted on the effectiveness of sexuality education for very young adolescents (VYAs) ages 10-14 years in Sub-Saharan Africa. Furthermore, evaluations of sexuality education programs often report outcomes of risky sexual practices, yet positive aspects of sexuality are hardly studied and rarely reported. This study evaluates the effectiveness of a Comprehensive Sexuality Education (CSE) intervention for VYAs in Uganda, analyzing both positive and negative outcome indicators. Methods: We conducted a mixed methods study, incorporating a cluster randomized trial (NCT03669913) among pupils in 33 randomly selected primary schools in Mbarara district. This was followed by a qualitative evaluation of the intervention in 4 schools that included 14 in-depth interviews and 3 focus group discussions distributed among pupils, teachers and parents. Quantitative data were analyzed using ordered logistic regression to compare differences in the change from baseline to endline between the intervention and control arms. We conducted bivariate analysis and multiple regression analysis controlling for key covariates, including age, gender, school location (rural vs urban), truancy, and orphanhood. Qualitative data were analyzed by thematic approach using ATLAS TI. Results: Between July 2016 and August 2017, 1096 pupils were recruited. Outcomes were studied among 380 pupils in the intervention arm and 484 pupils in the control arm. The proportion of pupils who ever had sex increased from 9 to 12.1% in intervention compared to 5.2 to 7.4% in the control group between baseline and endline, however the differences between groups were not statistically significant. We found greater improvements in sexual and reproductive health (SRH) knowledge among intervention schools (AOR: 2.18, 95% CI: 1.66-2.86) and no significant differences in self-esteem, body image or gender equitable norms. Qualitative evidence echoes perceived SRH knowledge acquisition, increased their perception of SRH related risks, and intentions to delay sexual intercourse to prevent unwanted pregnancy, HIV and other STIs. Conclusion: This study demonstrates that CSE can improve SRH knowledge and behavioral intentions among VYAs in Uganda. These results further emphasize the importance of initiating sexuality education before most adolescents have started engaging in sexual activity, enabling them to make informed decisions in the future

Getting over the Crisis of Identity for Stabilization of the Personality Professional Health

Статья посвящена становлению профессионального здоровья психолога как составляющей общего психологического здоровья личности. Профессиональное здоровье во многом обеспечивается успешным преодолением кризиса профессиональной идентичности в период студенчества. Профессиональная идентичность занимает особое место в структуре «Я», нестабильна в процессе обучения, представляет целостное образование, включающее в себя ценностно-мотивационные и когнитивные характеристики. У студентов выпускного курса отмечается более выраженное проявление кризиса идентичности. Помочь личности преодолеть кризис профессиональной идентичности могут умения: 1) рефлексировать изменение в социальном окружении, 2) совершенствовать систему ценностей, 3) анализировать собственную профессиональную идентичность. Статтю присвячено становленню професійного здоров’я психолога як складової частини загального психологічного здоров’я особистості. Професійне здоров’я у багатьох випадках забезпечується успішним подоланням кризи професійної ідентичності в період студентства. Професійна ідентичність займає особливе місце у структурі «Я», нестабільна у процесі навчання, є цілісним утворенням, що включає цінністно-мотиваційні та когнітивні характеристики. У студентів випускного курсу помічено більший прояв кризи ідентичності. Допомогти особистості подолати кризу професійної ідентичності можуть вміння: 1) рефлексувати зміни у соціальному оточенні, 2) удосконалювати особистісну систему цінностей, 3)аналізувати власну професійну ідентичність. This article is devoted to the development of the psychologist’s professional health. We consider professional health as an important part of the psychological health in general. Successful getting over the professional crisis of identity ensures professional health. Professional identity occupies especial place in the structure of personality. Professional identity is a whole formation consisting of cognitive, motivational and valuable characteristics. It is not stable in the process of education. Students-graduators have more implications of identity crisis. In order to get over the crisis a person should get skills: 1) to reflect the changes in the social environment, 2) to develop own value system, 3) to analyze own professional identity

Scaling in the Bombay Stock Exchange Index

In this paper we study BSE Index financial time series for fractal and multifractal behaviour. We show that Bombay stock Exchange (BSE)Index time series is mono-fractal and can be represented by a fractional Brownian motion.Comment: 11 pages,3 figure