Distribution and genetic diversity of three apple viruses in Belarus

Apple chlorotic leaf spot virus (ACLSV), apple stem pitting virus (ASPV), and apple stem grooving virus (ASGV) are common in all apple cultivating countries including Belarus. The aim of this investigation was to study the genetic diversity of the apple-tree viruses in Belarus. Virus-infected apple trees were identified by RT- PCR in modern horticultural plantations and were not found among old trees aged more than 50 years. The genome fragments of the ACLSV, ASPV, and ASGV viruses detected were cloned and sequenced. The analysis of their nucleotide sequences gives evidence of high molecular variability generated mostly by single nucleotide substitutions and rarely by single nucleotide deletions and insertions. Recombination processes could also make some contribution to the existing genetic diversity of the virus populations studied. Estimates of selective pressure on the genome fragments of ACLSV, ASPV and ASGV obtained in this study as well as homologous sequences from the GenBank database indicate negative selection, except for one codon in the sequence of the ACLSV coat protein, which is under positive selection. The study of phylogenetic relationships between viruses isolated in different countries did not reveal any clear-cut relationship between their geographical origin and the degree of similarity of virus genome fragments

FEATURES MODIFYING VARIOUS TYPES OF IRON-CARBON ALLOYS

The article describes the features of the modification of cast iron, high chrome cast iron and steel. It is shown that the modification of cast iron complex modifier should be based on the thickness of the walls of castings, and for steel and high chrome cast iron, it is beneficial to the macro and microstructure. The data confirming the removal of transcrystallization and size reduction microand macrostructure of castings in various types of iron-carbon alloys. Experimentally proved that in the transition from columnar to equiaxed structure observed increase in the number of eutectic cells, which confirms the position that transcrystallization terminated as a result of nucleation and growth of equiaxed crystalsin the area of concentration supercoolin

ABOUT THE PROJECT ON DEVELOPMENT OF PERSONALLY-ORIENTED ELECTRONIC EDUCATIONAL COURSES

Развитие самостоятельной познавательной деятельности, познавательного интереса, умения самостоятельно планировать, выполнять и контролировать результаты выполненной работы является личностным требованием к результатам освоения образовательных программ основного общего и среднего общего образования. Для этого следует активно внедрять в образовательный процесс дистанционные образовательные технологии и электронное обучение. Цель проекта заключается в разработке электронных учебных курсов, ориентированных на развитие самостоятельной познавательной деятельности обучающихся, учитывающих личностные, метапредметные и предметные требования к результатам освоения обучающимися основных образовательных программ соответствующего уровняThe development of independent cognitive activity, cognitive interest, the ability to independently plan, perform and monitor the results of work performed are personal requirements to the results of mastering educational programs of basic general and secondary general education. For this, distance educational technologies and e learning should be actively introduced into the educational process. The aim of the project is to develop e learning courses aimed at developing independent cognitive activity of students, taking into account personal, meta-subject and subject requirements to the results of mastering the basic educational programs of the appropriate leve

ИССЛЕДОВАНИЕ ГЕНЕТИЧЕСКОГО РАЗНООБРАЗИЯ СОРТОВ СЛИВ С ПОМОЩЬЮ МОЛЕКУЛЯРНЫХ МАРКЕРОВ SSR-ТИПА

Genetic diversity of the 50 plum accessions (species and varieties) cultivated in Belarus was studied by the SSR analysis using 20 markers. On the average 17.7 and 13.3 alleles were identified among domestic and diploid plum accessions respectively. Percentage of the unique genotypes were 0.681 and 0.552 and discrimination power levels were 0.811 and 0.741 for domestic and diploid plum accessions respectively. Cluster analysis allowed division of almost all accessions into two big groups according to their ploidy level. Genetic distances between the diploid plum varieties belonging to different species or interspecific hybrids were similar to the distances between intraspecific ones that indicates on low interspecific differentiation of diploid plum.Генетическое разнообразие 50 образцов сортов и видов слив, выращиваемых в Беларуси, было исследовано методом SSR-анализа с помощью 20 маркеров. Среди образцов сливы домашней выявлено в среднем 17,7 аллеля, сливы диплоидной – 13,3. Значение доли уникальных генотипов среди образцов сливы домашней составило в среднем 0,681, сливы диплоидной – 0,552, дискриминационной силы маркера – 0,8106 и 0,7405 соответственно. Кластерный анализ позволил разделить образцы, за небольшим исключением, на две большие группы в соответствии с их уровнем плоидности. Генетические расстояния между сортами сливы диплоидной, относящимися к разным видам или являющимися межвидовыми гибридами, сходны с внутривидовыми, что указывает на низкую межвидовую дифференциацию диплоидных слив

Влияние электроэрозионной обработки поверхности твердосплавных пластин на их фазовый состав и пайку режущих элементов из нитридной керамики

The effect of electroerosive treatment of the surface of carbide plates from superhard nitride ceramics on their phase composition and vacuum soldering of cutting elements is studied. Studies of the surface quality and elemental composition have been carried out. The surface of the plates for soldering is processed by the method of electroerosive cutting with brass wire in water, as well as by the method of electroerosive direct burn-through using copper and graphite electrodes in kerosene. The microstructure and elemental composition of the surfaces of hard-alloy plates were investigated by scanning electron microscopy and energy-dispersive X-ray spectroscopy before and after their processing. The analysis of the obtained data indicates that the best results at electro-erosion treatment of the hard-alloyed plate and the strongest bonding of brazed materials are achieved using a copper electrode and brass wire, since this ensures maximum wetting of the plate surface with solder based on Cu–Ti–Sn and the absence of pores. The hard-alloy cutter plate and ceramic cutting element were joined by high-temperature brazing in vacuum. Tests of hard-alloy plates with brazed cutting elements showed that the roughness of the machined surface of workpieces made of ХВГ steel with hardness of HRC 47–62 and ШХ15 steel with hardness of HRC 57–58 corresponded to 6–8 purity class at cutting speed of 155–170 m/min. The wear of the cutter along the trailing edge of 0.4 mm served as a criterion for evaluation of the cutting properties of superhard materials according to the results of durability tests.Изучено влияние электроэрозионной обработки поверхности твердосплавных пластин на их фазовый состав и вакуумную пайку режущих элементов из сверхтвердой нитридной керамики. Проведены исследования качества поверхности и элементного состава твердосплавных пластин для пайки режущих элементов из сверхтвердых материалов. Поверхность пластин для напайки обработана методом электроэрозионной резки латунной проволокой в воде, а также методом электроэрозионного прямого прожога с использованием медного и графитового электродов в керосине. Микроструктура и элементный состав поверхностей твердосплавных пластин были исследованы методами электронной микроскопии и энергодисперсионной рентгеновской спектроскопии до и после их обработки. Анализ полученных данных свидетельствует, что наилучшие результаты при электроэрозионной обработке твердосплавной пластины и наиболее прочное сцепление спаиваемых материалов достигаются при использовании медного электрода и латунной проволоки, так как при этом обеспечиваются максимальное смачивание поверхности пластины припоем на основе Cu–Ti–Sn и отсутствие пор. Соединение твердосплавной резцовой пластины и керамического режущего элемента производилось методом высокотемпературной пайки в вакууме. Испытания пластин с напайными режущими элементами показали, что шероховатость обработанной поверхности заготовок из стали ХВГ с твердостью HRC 47–62 и из стали ШХ15 с твердостью HRC 57–58 соответствовала 6–8-му классам чистоты при скорости резания 155–170 м/мин. Критерием для оценки режущих свойств сверхтвердых материалов по результатам стойкостных испытаний служил износ резца по задней грани 0,4 мм

ИССЛЕДОВАНИЕ СОВРЕМЕННЫХ БЕСКОЛЛЕКТОРНЫХ ДВИГАТЕЛЕЙ ПОСТОЯННОГО ТОКА ДЛЯ ПРИМЕНЕНИЯ В СИСТЕМЕ УПРАВЛЕНИЯ И СТАБИЛИЗАЦИИ АНТЕНН МИЛЛИМЕТРОВОГО ДИАПАЗОНА

The results of the reserch of possibilities of using brushless motors in the stabilization systems of scanning antennas onboard millimeter wave radar are given. For this purpose, peculiarities of change of momentary motor shaft speed for various values of acceleration have been studied in the course of experimental studies, as well as a comparison of the possible operating modes have been complited. The reserch was carried out with engines MAXON EC-max-2 .Приведены результаты исследования возможности применения бесколлекторных двигателей в системах стабилизации сканирующих антенн миллиметрового диапазона бортового радиолокатора. Для этого, в ходе экспериментальных исследований, были изучены особенности изменения моментальной скорости вращения вала двигателя при различных значениях ускорения, а также проведено сравнение возможных рабочих режимов. Исследования производились с двигателями MAXON EC-max-2

Resource flows and levels of spending for the response to HIV and AIDS in Belarus

<p>Abstract</p> <p>Background</p> <p>Belarus has a focused HIV epidemic concentrated among injecting drug users, female sex workers and men who have sex with men. However, until 2008, Belarus had no way of evaluating HIV spending priorities. In 2008, Belarus committed to undertaking a comprehensive National AIDS Spending Assessment (NASA) in order to analyze HIV spending priorities. NASA was used to 'follow the money' from the funding sources to agents and providers, and eventually to beneficiary populations.</p> <p>Findings</p> <p>Belarus spent the majority of its funding on prevention, diagnosis and treatment of sexually transmitted infections and on securing the blood supply. International donors and NGOs working within Belarus spent the majority of their funding on preventative activities for high risk groups while Global Fund to Fight AIDS, Tuberculosis, and Malaria (GFATM) solely funded antiretroviral treatment.</p> <p>Conclusions</p> <p>The data and experience obtained through conducting NASA will help build capacity for future resource tracking activities for HIV and other health priorities. This experience established the foundation for enhanced and future consistent quality-reporting of National Health Accounts. Monitoring the flow of resources for Belarus' HIV response provides valuable strategic information that can improve operations and planning as well as mobilize greater resources. NASA offers Belarusian policy makers an overview of HIV activities that merit their priority attention. In addition, the findings from Belarus are particularly relevant for the rest of the Commonwealth of Independent States due to their similar epidemiological profiles and centrally planned systems. The Belarusian government faces future challenges, especially in increasing public investments in HIV prevention for female sex workers and their clients, men who have sex with men, and among intravenous drug users.</p

INFLUENCE OF THE MACROSTRUCTURE ON SEGREGATION OF THE STEEL INGOT

A theoretical analysis of the influence of carbon content in the steel and nature of macrostructure on segregation of impurities in the crystallization process were made. It is shown that increase of carbon content and transgranular macrostructure creation degree of segregation is being increased. A comparison of sulfur segregation in the ingot with equiaxial and transgranular structure was carried out and the theoretical points were confirmed