Recurrent horizontal transfer identifies mitochondrial positive selection in a transmissible cancer

Abstract: Autonomous replication and segregation of mitochondrial DNA (mtDNA) creates the potential for evolutionary conflict driven by emergence of haplotypes under positive selection for ‘selfish’ traits, such as replicative advantage. However, few cases of this phenomenon arising within natural populations have been described. Here, we survey the frequency of mtDNA horizontal transfer within the canine transmissible venereal tumour (CTVT), a contagious cancer clone that occasionally acquires mtDNA from its hosts. Remarkably, one canine mtDNA haplotype, A1d1a, has repeatedly and recently colonised CTVT cells, recurrently replacing incumbent CTVT haplotypes. An A1d1a control region polymorphism predicted to influence transcription is fixed in the products of an A1d1a recombination event and occurs somatically on other CTVT mtDNA backgrounds. We present a model whereby ‘selfish’ positive selection acting on a regulatory variant drives repeated fixation of A1d1a within CTVT cells

JUNIORSKILLS AS A FACTOR OF CREATION OF MULTIMEDIA JOURNALISM OF THE FUTURE (ON THE EXAMPLE OF THE REGIONAL CHAMPIONSHIP “JUNIORSKILLS” 2018 MOSCOW) / JUNIORSKILLS КАК ФАКТОР СОЗДАНИЯ МУЛЬТИМЕДИЙНОЙ ЖУРНАЛИСТИКИ БУДУЩЕГО (НА ПРИМЕРЕ РЕГИОНАЛЬНОГО ЧЕМПИОНАТА JUNIORSKILLS 2018 МОСКВА)

The article presents a brief history of the development of the non-commercial international movement of professional training of qualified personnel “WorldSkills International” (“WSI”). For the first time in the world of scholarship the authors of the article are exploring this direction, determining the prospects of the “JuniorSkills” Championship for Multimedia Journalism in Russia and its role in the training and career guidance of young professionals. The article uses the method of systemic analysis obtained as a result of personal experience in judging and expert evaluation of the regional Championship “JuniorSkills” 2018 in Moscow. Professions forming a unified whole are being presented in the form of diagrams in one of the most popular formats for multimedia storytelling – “longread”, the production of which is the main task of the competence of “Multimedia journalism”. The conducted survey allowed to identify critical issues of training participants (students) and experts for the next “JuniorSkills” Championships. On the basis of the analysis concrete actions are proposed aimed at raising the standards of professional training and the development of multimedia journalism as an independent profession of the future. In this article for the first time conclusions are formulated making it possible to estimate this direction of “JuniorSkills” (“JS”) as being perspective and innovative for training new generations of universal journalists. В работе представлена краткая история развития некоммерческого международного движения профессиональной подготовки квалифицированных ка-дров «WorldSkills International» («WSI»). Авторы статьи впервые в научном мире исследуют данное направление, определяют перспективы проведения Чемпиона-та «JuniorSkills» по мультимедийной журналистике в России и его роль в профессиональной подготовке и профориентации молодых специалистов. В статье используется метод системного анализа, полученного в результате личного опыта по судейству и экспертной оценке Регионального Чемпионата «JuniorSkills» 2018 в Москве. В виде схемы представлены профессии, которые составляют единое целое наиболее популярного формата мультимедийного сторителлинга — лонгрид, производство которого является основным заданием по компетенции «Мультимедийная журналистика». Проведенное анкетирование позволило определить важнейшие вопросы подготовки участников (школьников) и экспертов к следующим Чемпионатам «JuniorSkills». На основании анализа предложены конкретные действия, направленные на повышение стандартов профессиональной подготовки и развитие мультимедийной журналистики как самостоятельной профессии будущего. В данной статье впервые сформулированы выводы, позволяющие оценить данное направление «JuniorSkills» («JS») как перспективное и инновационное для подготовки универсальных журналистов нового поколения

Evolution of an ensemble of spherical particles in metastable media with allowance for their unsteady-state growth rates

The process of particle nucleation and growth at the initial and intermediate stages of bulk crystallization in metastable liquids is studied. An integrodifferential model of balance and kinetic equations with corresponding boundary and initial conditions is formulated with allowance for non-stationary temperature/concentration field around each evolving particle. The model is solved using the saddle-point technique in a parametric form. The particle-radius distribution function, supercooling/supersaturation of liquid, total number of particles in liquid and their average size are found analytically. The melt supercolling (solution supersaturation) decreases with time due to the latent heat of phase transformation released by evolving crystals. As this takes place, the particle-radius distribution function is bounded by the maximal size of crystals and shifts to larger crystal radii with time as a result of particle nucleation and growth

Some Aspects of Development and Histological Structure of the Visual System of Nothobranchius Guentheri

In this, work some aspects of the development of the visual system of Nothobranchius guentheri at the main stages of ontogenesis were described for the first time. It was possible to establish that the formation of the visual system occurs similarly to other representatives of the order Cyprinodontiformes, but significantly differs in terms of the individual stages of embryogenesis due to the presence of diapause. In the postembryonic period, there is a further increase in the size of the fish’s eyes and head, to the proportions characteristic of adult fish. The histological structure of the eye in adult N. guentheri practically does not differ from most teleost fish living in the same environmental conditions. The study of the structure of the retina showed the heterogeneity of the thickness of the temporal and nasal areas, which indicates the predominant role of peripheral vision. Morphoanatomical measurements of the body and eyes of N. guentheri showed that their correlation was conservative. This indicates an important role of the visual system for the survival of fish in natural conditions, both for the young and adults. In individuals of the older age group, a decrease in the amount of sodium (Na) and an increase in magnesium (Mg) and calcium (Ca) were found in the eye lens. Such changes in the elemental composition of the lens can be a sign of the initial stage of cataractogenesis and disturbances in the metabolism of lens fibers as a result of aging. This allows us to propose N. guentheri as a model for studying the structure, formation, and aging of the visual and nervous systems