50 research outputs found

    Radiation of a Charge Exiting Open-Ended Waveguide with Dielectric Filling

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    We consider a semi-infinite open-ended cylindrical waveguide with uniform dielectric filling placed into collinear infinite vacuum waveguide with larger radius. Electromagnetic field produced by a point charge or Gaussian bunch moving along structure's axis from the dielectric waveguide into the vacuum one is investigated. We utilize the modified residue-calculus technique and obtain rigorous analytical solution of the problem by determining coefficients of mode excitation in each subarea of the structure. Numerical simulations in CST Particle Studio are also performed and an excellent agreement between analytical and simulated results is shown. The main attention is paid to analysis of Cherenkov radiation generated in the inner dielectric waveguide and penetrated into vacuum regions of the outer waveguide. The discussed structure can be used for generation of Terahertz radiation by modulated bunches (bunch trains) by means of high-order Cherenkov modes. In this case, numerical simulations becomes difficult while the developed analytical technique allows for efficient calculation of the radiation characteristics.Comment: 13 pages, 11 figure

    Genome assembly of Vitis rotundifolia Michx. using third-generation sequencing (Oxford Nanopore Technologies)

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    The immune North American grapevine species Vitis rotundifolia Michaux (subgen. Muscadinia Planch.) is regarded as a potential donor of disease resistance genes, withstanding such dangerous diseases of grapes as powdery and downy mildews. The cultivar ‘Dixie’ is the only representative of this species preserved ex situ in Russia: it is maintained by the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) in the orchards of its branch, Krymsk Experiment Breeding Station. Third-generation sequencing on the MinION platform was performed to obtain information on the primary structure of the cultivar’s genomic DNA, employing also the results of Illumina sequencing available in databases. A detailed description of the technique with modifications at various stages is presented, as it was used for grapevine genome sequencing and whole-genome sequence assembly. The modified technique included the main stages of the original protocol recommended by the MinION producer: 1) DNA extraction; 2) preparation of libraries for sequencing; 3) MinION sequencing and bioinformatic data processing; 4) de novo whole-genome sequence assembly using only MinION data or hybrid assembly (MinION+Illumina data); and 5) functional annotation of the whole-genome assembly. Stage 4 included not only de novo sequencing, but also the analysis of the available bioinformatic data, thus minimizing errors and increasing precision during the assembly of the studied genome. The DNA isolated from the leaves of cv. ‘Dixie’ was sequenced using two MinION flow cells (R9.4.1)

    Analysis of opinions of the faculty of preventive medicine graduates on education in the USMU and preparedness for the state final examination and accreditation

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    The purpose of this survey is to analyze the satisfaction level of the graduates of the Faculty of preventive medicine with the quality of education in the Ural state medical University and evaluation of their preparedness for the State Final Examination and accreditation. In this article there are the results of the questionnaire among the 6th year students of the Faculty of preventive medicine over a period from 2017 till 2018. Indicators that were analyzed are the applicants’ awareness of their future career, the graduates’ interest in occupational work and evaluation of their knowledge and skills acquired during education and their preparedness for professional activity.Целью данного исследования являлся анализ степени удовлетворенности выпускников медико-профилактического факультета качеством обучения в Уральском государственном медицинском университете и оценки своей готовности к государственной итоговой аттестации и аккредитации. В статье представлены результаты анкетирования учащихся 6 курса медико-профилактического факультета, проведенного в 2017 и 2018 годах. Были проанализированы следующие показатели: осведомленность абитуриентов о своей будущей профессии при поступлении в УГМУ, заинтересованность выпускников в работе по специальности, а также оценка выпускниками полученных ими за период обучения знаний и умений и своей готовности к осуществлению различных видов профессиональной деятельност

    Influence of different forest management techniques on the quality of wood

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    The issue of accelerated forestry plantation with high-quality wood using the best soils in terms of productivity, fertilizers, and intensive treatment has become quite relevant due to increased demand for forestry products and higher requirements for environmentally friendly use of forest resources. This paper presents the results of a study on the impact of various techniques for treating coniferous plantations, including thinning, fertilization, and herbicide processing, on wood quality key indicators. The paper examined the wood density, correlation of early and late wood zones, and the cell wall thickness for 38-year-old pine trees grown on the sample plots of Siversky leskhoz (Leningrad region, Gatchinskiy district) at different treatment and density control techniques. It has been established that the highest basis density of wood corresponds to the samples grown at the density variant of 1 t/ha and double herbicides treatment, and the lowest basis density value was recorded at the option of 4 t/ha with combined treatment. It has been shown that the increase of width index for early wood is influenced by the lower density of 1 t/ha and one-time herbicide treatment, for late wood – by the lower density of 1 t/ha and repeated treatment with herbicides. The increase in average cell wall thickness for early and late wood is observed when the density increases up to 4 t/ha and double herbicides treatment. The results obtained provide a valuable scientific contribution to general forestry knowledge and have practical value in plantation forestry. © 2021, Tech Science Press. All rights reserved

    Проблематика и методология языковой локализации продукта

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    This article is devoted to reviewing important components of globalization such as localization and internationalization. The article presents the main concepts of these processes and establishes the basic differences between language localization and translation. The text also concerns the systematization of problems in the process of working on the localization of a product, methods of performing localization, theoretical methods of internationalization and localization.Данная статья посвящена ознакомлению с такими важными составляющими глобализации как локализация и интернационализация. В статье приведены основные понятия данных процессов и установлены базовые различия между языковой локализацией и переводом. Так же текст касается систематизации проблематик в процессе работы над локализацией продукта, способах выполнения локализации и теоретических методах интернационализации и локализации

    Строение приповерхностной части ледника в районе бухты Тала (Восточная Антарктида) по результатам георадарных работ сезона 2018/19 г.

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    The paper discusses the results of the ground-penetrating radar (GPR) survey carried out in February 2019 in the area of Thala Bay (Larsemann Hills, East Antarctica). Thala Bay is one of the strategic facilities of the Russian Antarctic Expedition (RAE) in the Progress station area as since 2019 heavy cargo has been unloaded here intended for the construction of new facilities at the Vostok station. Transportation of goods to the point of formation of logistic traverses takes place on ice tracks, whose safety must be evaluated taking into account the expanded system of crevasses. In addition, the current track is characterized by a significant slope of the terrain, which also complicates the relocation of heavy equipment.In February 2019, a GPR survey was carried out within the Thala Bay area to assess the possibility of organizing an alternative section of the route within it. According to the visual observations, this area was characterized by an extensive system of crevasses, the width of which at the surface reached 20-30 cm, and the prevailing longitudinal direction coincided with the direction of the route. The task of the geophysical survey was to map the crevasses not identified by visual inspection and to determine their morphology. According to the GPR data, it was shown that the crevasses within the site are located to the firn layer and are characterized by an irregular shape, significantly expanding at the deeper levels and reaching a width of 6 m. The results of the survey are illustrated with the scheme of the firn thickness which shows location of the crevasses. According to the recommendations of the authors, the section of the glacier is suitable for operation provided the glaciological situation using the GPR method is monitored annualy.В настоящей работе обсуждаются результаты георадиолокационных исследований, выполненных в районе российской антарктической станции Прогресс (оазис Холмы Ларсеманн, Восточная Антарктида) в сезон 64-й Российской антарктической экспедиции (РАЭ) в 2018/19 г. Изыскания проводились с целью оценки безопасности участка ледника в районе пункта разгрузки судов в бухте Тала для проложения в его пределах трассы передвижения тяжелой санно-гусеничной техники. По итогам георадарного профилирования в пределах исследуемого района выявлена сеть трещин, развитых в снежно-фирновой толще и достигающих максимальной ширины 6 м. Результаты работ проиллюстрированы схемой мощности снежно-фирновой толщи по участку работ и их распространения по состоянию на февраль 2019 г

    Факторы формирования поверхностного притока к озерам антарктического оазиса Холмы Ларсеманн

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    The study aims to identify formation factors of water inflow to the Antarctic lakes of the Larsemann Hills oasis (East Antarctica). The objects of study are 11 lakes of the oasis. The analysis was performed based on the expeditionary data of the Russian Antarctic Expedition (RAE): 63rd season (23 December 2017 – 3 February 2018), 64th season (12 January 2019 – 27 February 2019), 65th season (2 November 2019 – 24 March 2020). Data of lakes water level observations, aerial photography of the unmanned aerial vehicle (UAV) and route surveys are given, the results of identifying the boundaries of the lakes catchments are presented. The factors that determine the formation of water inflow to the lakes in this region were identified based on the analysis of the materials. The most significant are the meteorological conditions, the presence of perennial snowfields and glacial areas in the catchments, and the presence of lakes that can cause outburst flood. The seasonally thawed layer also has an impact on the formation of the inflow to the lakes. The vegetation cover is not so important for inflow formation in this region due to the physical and geographical conditions. As for anthropogenic activity, it mainly affects the environmental situation of the catchments and water quality, while the anthropogenic influence on the formation of water inflow to the lakes in the oasis is limited to the territories of polar stations. The factors identified should be taken into account in the further study of hydrological processes, the creation of models that describe them, and the organization of field observations.Объектами исследования являются 11 водоемов антарктического оазиса Холмы Ларсеманн. Работа выполнена по материалам сезонных работ 63 — 65-й РАЭ: используются наблюдения за уровнем воды озер, аэрофотосъемки БПЛА, маршрутные обследования, приведены результаты выделения границ водосборных площадей озер. Наиболее значимыми выявленными факторами, определяющими формирование притока воды к озерам, являются метеорологические условия (количество твердых осадков, ветровой режим, температура воздуха), наличие многолетних снежников и ледниковых участков на водосборах, прорыв верхнего в системе озера. Сезонно-талый слой рыхлых отложений регулирует склоновый сток по мере протаивания и промерзания. Особенностью оазиса является то, что на формирование стока практически не влияют растительный покров и антропогенная деятельность

    Строение снежно-ледовых перемычек прорывных озёр полуострова Брокнес (оазис Холмы Ларсеманн, Восточная Антарктида) по данным георадиолокации

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    During the summer field season of the 65th Russian Antarctic Expedition a research aimed at studying the structure of the snow-­ice dams of the Lakes Progress and Discussion (Larsemann Hills, East Antarctica), which are characterized with annual outburst floods, was carried out. Survey was performed using ground­penetrating radar sounding complemented with non­core drilling and analysis of the aerial photo data acquired with unmanned aerial vehicle during the last field seasons. The results show that location of the waterways, which occur during the outbursts of the both lakes, does not change significantly year in year out and fits a linear depression in basement topography under the dam and a following flexure of the ice layer. During the winter period, the opened channels are being filled with snow, and thereby a natural soſtened zone is being formed. Further outburst flood propagates mainly within this zone. Monitoring survey of the snow­i-ce dam of the Progress Lake during the summer period showed that destruction of the dam does not happen rapidly when the outburst takes place, but begins a few weeks before it with gradual filtration within the snow layer.Приведены результаты изучения строения снежно-ледовых перемычек прорывоопасных озёр Прогресс и Дискашн (оазис Холмы Ларсеманн, Восточная Антарктида), выполненные методом георадиолокации. Дополнительно проведены бескерновое механическое бурение и аэрофотосъёмка с использованием беспилотного летательного аппарата. На примере изученных водоёмов установлены основные геолого-гляциологические тенденции формирования прорывных паводков ледниковых озёр

    ЭКСПЕРИМЕНТАЛЬНАЯ ОЦЕНКА ОТДАЛЕННЫХ ПОСЛЕДСТВИЙ ТОКСИЧЕСКОГО ДЕЙСТВИЯ ЦИТОСТАТИЧЕСКИХ ПРЕПАРАТОВ НА МУЖСКУЮ РЕПРОДУКТИВНУЮ ФУНКЦИЮ

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    The purpose of the study was a comparative assessment of long-term toxic effects of cytotoxic drugs (anthracycline antibiotics, topoisomerase activity inhibitors, platinum and taxane complex compounds) on male reproductive function. Material and methods. 2.5-month-old male Wistar rats were used in the experiment. The following cytotoxic drugs were administered to animals in the maximum tolerated dose: Vepesid (etoposide, Teva, Israel), Irinotecan (Campto, Rhone-Poulens, Great Britain), Carboplatin (kemokarb, Dabur India Ltd., India), Paclitaxel (mitotax, Dr. Reddy`s, India), Platidiam (Lachema, Czech Republic), Pharmorubicin (Farmitalia, Carlo Erba). The reproductive status was assessed 90 and 180 days after administration of cytotoxic drugs. The fertilizing ability, productivity of spermatogenesis and the viability of a fertilized egg were evaluated. To determine the sensitivity of different types of spermatogonia to the drugs, we studied the dynamics of the number of their cell populations 2, 5, 10, 15, 30, 90 and 180 days after starting the experiment. Results. In long-term follow-up following administration of farmorubicin and paclitaxel to male rats, a complete (pharmacorubicin) or partial (paclitaxel) decrease in the fertilizing ability due to oligospermia was detected. The decrease in spermatogenesis productivitywas reversible. In rats treated with topoisomerase activity inhibitors, the fertilizing ability was preserved, however spermatogenic failure was also seen, as judged by the total sperm number. In the long term after the administration of platinum complexes, no decline in the reproductive function was observed, and the spermatogenesis productivity corresponded to the control values. The severity of toxic effects on gonads was determined by the sensitivity of different types of spermatogonia to the action of drugs. Pharmorubicin and paclitaxel exerted a pronounced toxic effect on stem spermatogonial cells. Paclitaxel and carboplatin induced dominant lethal mutations in spermatogonia, but the likelihood of gametes bearing genetic damage incompatible with life decreased over time.  Целью исследования явилась сравнительная оценка отдаленных токсических эффектов цитостатических препаратов (антрациклиновых антибиотиков, ингибиторов топоизомеразной активности, комплексных соединений платины и таксанов) на мужскую репродуктивную функцию. Материал и методы. Эксперименты проведены на крысах-самцах сток Вистар, возраст 2,5 мес. Животным вводили в максимально-переносимой дозе следующие цитостатические препараты: Вепезид (этопозид, Теvа, Израиль), Иринотекан (Кампто, Rhone-Poulens, Великобритания), Карбоплатин (кемокарб, Дабур Индия Лтд, Индия), Паклитаксел (митотакс, Dr. Reddy`s, Индия), Платидиам (Lachema, Чехия), Фарморубицин (Farmitalia, Carlo Erba). Оценка репродуктивного статуса проводилась через 90 и 180 сут после их введения, что соответствует токсическому действию на сперматогонии. Оценивались способность к зачатию, продуктивность сперматогенеза, жизнеспособность оплодотворенной яйцеклетки. Для определения чувствительности разных типов сперматогоний к действию препаратов проводилось изучение динамики численности их клеточной популяции через 2, 5, 10, 15, 30, 90 и 180 сут после начала эксперимента.Результаты. В отдаленные сроки после введения крысам-самцам фарморубицина и паклитаксела выявлялось полное (фарморубицин) или частичное (паклитаксел) снижение способности к зачатию, обусловленное олигоспермией. Снижение продуктивности сперматогенеза носило обратимый характер. У крыс, получавших ингибиторы топоизомеразной активности, способность к зачатию сохранялась, но наблюдалась, судя по общему количеству сперматозоидов, недостаточность сперматогенеза. В отдаленные сроки после введения комплексных соединений платины воспроизводящая функция не снижалась, продуктивность сперматогенеза соответствовала контрольным значениям. Степень выраженности токсических эффектов на гонады определялась чувствительностью разных типов сперматогоний к действию препаратов. Фарморубицин и паклитаксел оказывали выраженное токсическое действие на стволовые сперматогониальные клетки. Паклитаксел и карбоплатин индуцировали доминантные летальные мутации в сперматогониях, но с течением времени вероятность появления гамет, несущих генетические повреждения, несовместимые с жизнью, снижалась
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