Comparison of Sex Determination in Vertebrates (Nonmammals)

The chapter is devoted to the consideration of sex determination in vertebrate groups of nonmammalians: fish, amphibians, reptiles, and birds. Attention is drawn to the fact that all these groups of animals, unlike mammals, are implemented hormonal control options for primary sex determination, and there is a possibility of sex reversion. Determination of gonadal development in vertebrates like testis or ovary was initially controlled mainly by sex hormones (fish and amphibians). Later, various sex determining genes were involved in this process. The system was quite plastic and was able to respond to changes in external conditions (reptiles). The appearance of heteromorphic sex chromosomes (birds) has led to the emergence of some specific W chromosomal signal, which provides estrogen control of the development of a heterogametic sex. In mammals, the control of the primary determination of sex (the appearance of the gonad) becomes purely genetic, and the role of sex hormones is reduced to the differentiation of testis or ovaries

Polar-ring galaxies in the Illustris TNG50 simulation

Polar-ring galaxies (PRGs) are an outstanding example of galaxies with misaligned kinematics where a typically red central galaxy is surrounded by a large-scale ring or disk of stars, gas and dust oriented almost perpendicular to the main body. It is believed that polar structures are formed in a secondary event after the assembly of a central galaxy, but due to their scarcity, their formation paths are not well constrained yet. We present a study of PRGs from TNG50 cosmological simulations, focusing on the origin of their polar structures. Based on the synthetic images and baryonic mass distribution, we found 6 galaxies with stellar polar rings. Using Supplementary Data Catalogues and available particle data, we confirm that the selected galaxies are direct analogs of real PRGs. In our sample, the polar structures are a result of the close interaction between the host galaxy and its companion. We track two formation paths for the stellar polar rings in our sample: (i) star formation in the accreted gas, (ii) tidal disruption of the satellite's stellar component. Rings formed during the first scenario are, on average, bluer and younger than ones formed due to the satellite disruption. We report a steady increase of the ring's inclination around the two most massive galaxies across a few billion years with a rate of $\approx8^{\circ}$/Gyr. The formation of a polar structure in some cases can increase the nuclear activity of the central galaxy and/or turn the active nucleus off completely.Comment: 19 pages, 18 figures, accepted for publication in MNRA

An Assessment of Policy Measures to Support Russia's Real Economy

"This paper presents the results of an analytical project on the design and approbation of methodology for assessing and monitoring the measures taken by the government of the Russian Federation in response to the recent worldwide fiscal crisis. The paper is based on our analysis of about 100 measures initiated between October 2008 and March 2009 to support Russia's real economy. Within the scope of this analysis, we singled out the main beneficiaries according to industry and enterprise scale, and estimated the effects of the measures during the crisis and recovery phases. The paper also describes the major risks the Russian government will face as a result of implementing the aforementioned measures and identifies the key problems and inconsistencies of the anti-crisis programme." (author's abstract

Peroral Endoscopic Myotomy in Diffuse Thickened Esophageal Wall in an Adolescent

Achalasia is an extremely rare pathology in children. Peroral endoscopic myotomy (POEM) is the gold standard for the surgical treatment of achalasia in adults, but only a limited number of cases of achalasia treatment using POEM in children have been published in the literature. Sometimes, high-resolution manometry signs of achalasia can mimic diffuse esophageal leiomyoma. This case report represents the first known successful performance of POEM on a 15-year-old female with diffuse thickening of the esophagus with signs and symptoms of achalasia and suspicion for Alport syndrome associated with diffuse esophageal leiomyoma

Injection Process Control of the Well at the Hydrodynamic Research of Coalbed

This scientific work is devoted to the study results of water injection process into the well at the hydrodynamic research by using the high pressure unregulated pump. The injection process should be accompanied by the retention of some hydraulic parameters at constant level during some time. Various variants for use of mechatronic nodes for automatization of water injection process are considered. Scheme for reducing the load on the pump and equipment in hydraulic system and also for improving the quality control system with high accuracy is shown. Simulation results of injection process into the well at the pressure and consumption fixation and recommendations for the use of the proposed schemes depending on the technological process are given

Lumbar spine segmental instability in degenerative spine conditions

1240% of people with low back pain have spinal instability in degenerative-dystrophic diseases of the spine. The paper highlights the biomechanical basis for the development of segmental instability and discusses various hypotheses for the development of this condition. The authors describe the modern methods of neuroimaging used in the diagnosis of segmental instability, such as radiography, functional spondylography, CT, functional CT, MRI. Further, the paper presents provocative tests used in the diagnosis of instability: passive extension of the lumbar spine, standing, sitting, pron-instability, "scissors", compression of spinous processes, forward lean in standing position, and some others. The authors shared their experience in diagnosing segmental instability. However, the discrepancy between the data of instrumental examinations and patient complaints, poorly studied rotational and lateral instability in osteochondrosis indicate the need for a more detailed study of the instability of the spine as a whole

Chayandinskoye field is the project of new technologies implementation in East Siberia

Modern level of study of structure of Chayandinskoye oil and gas condensate field is characterized by implementation of 3D seismic survey, carried out using a rich azimuth seismic survey system with a fold of 240. Complex seismic and geological conditions within this part of Eastern Siberia dictate high requirements to quality of field 3D seismic operations. A geological section of an area of operations is characterized by Lower Proterozoic formations of crystalline basement and Vendian, Cambrian, Jurassic, Quaternary deposits of the sedimentary cover. The main role in structure of the sedimentary cover is played by clastic and carbonate deposits of Vendian and halogen-carbonate formations of Cambrian Period. Productive part of a section refers to Botuobinsk, Khamakin and Talakh suits and is characterized by a very complex structure of natural reservoirs. Study of productive section structure is caused by need to prepare a field for production drilling and its subsequent development. In order to reveal features of structure of productive part of a section in a region with complex seismic and geological conditions, migration is used up to the summation in the deep region. Wide-azimuth observation system is aimed to study the most important challenges of medium structure such as direction and nature of change in fracture, study of azimuthal anisotropy of velocity characteristics of section and identification of characteristics of elastic properties change. Base technologies to study anisotropy of geological section properties are adapted and introduced into seismic exploration technique. They are as follows: 1) a method based on study of geometric attributes; 2) azimuthal analysis of velocities; 3) azimuth AVO-analysis (AVAZ); 4) anisotropic inversion. Based on results of processing and complex interpretation of seismic data of MOGT-3D works at the Chayandinskoye oil and gas condensate field the most important information about geological structure of sedimentary cover deposits and productive section was obtained. That allowed to significantly clarifying concept of structure of productive formations and geological development of this area. It also allowed determining distribution of reservoirs and evaluating reserves with considered new built structural and tectonic model