123 research outputs found

    ОЦЕНКА ВИБРАЦИИ ПУТИ ПРИ ВЫСОКИХ СКОРОСТЯХ ДВИЖЕНИЯ

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    This article proposes an analytical method of assessment of track’s vibration level, based on the spectral decomposition of functions of sleeper deflections under the influence of passing axles of rolling stock. Train is considered to be formed from vehicles of the same type and of unlimited length. Vibrations are studied within a stable system of coordinated, related to the ground, for one sleeper during the passage of a train of unlimited length through track’s cross section. The computational scheme takes into account vibration damping of a track, considered as an infinitely long beam on a viscoelastic foundation. The algorithm and the results of numerical calculation of track’s vibration are given at speeds in the area of conventionally critical speed (the speed at which the model that does not take into account energy dissipation on the way predicts vibrations of unrestricted amplitude).It is shown that when the train’s speed is equal to conditionally critical (of about 500–600 km / h), the track’s vibrations reach their peak in the whole frequency range. Results are obtained for a wide frequency range from 16 to 32000 Hz in 12 octave bands in decibel scale. Methods, outlined in this article, make it possible to solve problems of accumulation of residual track’s deformations, as well as give direction for solving problems associated with the vibrations of the roadbed.Авторами предложен аналитический метод оценки уровня вибрации пути и, в частности, виброускорений шпалы при прохождении поезда со скоростями свыше 500 км/ч. В расчетной схеме учтено демпфирование пути как бесконечной балки на упругом основании. Приведены алгоритм и результаты численного расчета вибраций при скоростях движения экипажа в зоне условно-критической скорости (когда в модели, не учитывающей рассеяния энергии в пути, прогнозируется возникновение колебаний неограниченно большой амплитуды). Показано, что при движении поезда со скоростью, равной условно-критической – порядка 500-600 км/ч, вибрации достигают максимума во всем частотном диапазоне. Решения получены для широкого спектра частот от 16 до 32000 Гц в двенадцати октавных полосах в децибельной шкале

    The optical identifcation of events with poorly defined locations: The case of the Fermi GBM GRB140801A

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    We report the early discovery of the optical afterglow of gamma-ray burst (GRB) 140801A in the 137 deg2^2 3-σ\sigma error-box of the Fermi Gamma-ray Burst Monitor (GBM). MASTER is the only observatory that automatically react to all Fermi alerts. GRB 140801A is one of the few GRBs whose optical counterpart was discovered solely from its GBM localization. The optical afterglow of GRB 140801A was found by MASTER Global Robotic Net 53 sec after receiving the alert, making it the fastest optical detection of a GRB from a GBM error-box. Spectroscopy obtained with the 10.4-m Gran Telescopio Canarias and the 6-m BTA of SAO RAS reveals a redshift of z=1.32z=1.32. We performed optical and near-infrared photometry of GRB 140801A using different telescopes with apertures ranging from 0.4-m to 10.4-m. GRB 140801A is a typical burst in many ways. The rest-frame bolometric isotropic energy release and peak energy of the burst is Eiso=5.540.24+0.26×1052E_\mathrm{iso} = 5.54_{-0.24}^{+0.26} \times 10^{52} erg and Ep,rest280E_\mathrm{p, rest}\simeq280 keV, respectively, which is consistent with the Amati relation. The absence of a jet break in the optical light curve provides a lower limit on the half-opening angle of the jet θ=6.1\theta=6.1 deg. The observed EpeakE_\mathrm{peak} is consistent with the limit derived from the Ghirlanda relation. The joint Fermi GBM and Konus-Wind analysis shows that GRB 140801A could belong to the class of intermediate duration. The rapid detection of the optical counterpart of GRB 140801A is especially important regarding the upcoming experiments with large coordinate error-box areas.Comment: in press MNRAS, 201

    ТЕКТОНИКА И МОДЕЛЬ ФОРМИРОВАНИЯ ОНЕЖСКОГО СИНКЛИНОРИЯ В ПАЛЕОПРОТЕРОЗОЕ

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    Consideration is being given to the Onega Paleoproterozoic structure (Onega synclinorium, OS) as a tectonotype of intraplate negative structures, which experience intermittent subsidence over a long period of time. The paper presents a model of the OS and discusses its tectonic evolution. The model is based on the geological and structural data, already published and collected so far by the authors, as well as on the data concerning the OS deep structure, particularly on the interpretation of the 1-EV seismic profile and potential fields. The proposed model illustrates an example of conjectured interaction between different geodynamic factors and explains reasons for the development of the OS throughout the Paleoproterozoic, including the periods of intense subsidence and magmatism, inversions of local basins comprising the Onega trough, and deformations of the Paleoproterozoic strata. An important role in the formation of the OS was played by shear dislocations within an imbricate fan of its controlling Central-Karelian shear zone. The shear dislocations were accompanied by rotation of a large block located to the west of the OS, which led to the rotational-indentational interaction between adjacent blocks and to compensated coexistence among transtensional and transpressional regimes along their separating shear zone. Compensatory dynamic mechanism also manifested itself in crustal layers at the base of the OS. Horizontal flow of the mid-crustal masses and their outflow from the depression were compensated by the development of deep-seated thrust duplexes and uplifts around the depression as well as by the upper crustal extension associated with low-angle dilatant normal faulting. Successive propagation of these faults, dynamically related to shear dislocations within an imbricate fan of the Central Karelia zone, controlled the formation features and southward migration of the OS-contained basins as well as magmatic and syllogenesis-related occurrences. Multilayered subhorizontal flow of low-viscosity rocks at the base and inside the OS section against the background of shear dislocations gave rise to the occurrence of crest-like and diapir-like folding. The processes of OS formation occurred amid the development and localization of active mantle plumes and asthenospheric diapirs. One of the factors of their development and localization were the phenomena of relative decompression within the imbrication fan of the Central Karelian shear zone.Охарактеризовано строение и разработана модель тектонической эволюции Онежской палеопротерозойской структуры (синклинория, ОС), представляющей собой тектонотип внутриплитных отрицательных структур, испытывавших периодическое прогибание на протяжении длительного времени. Модель разработана на основе обобщения опубликованных и авторских геолого-структурных материалов, а также сведений о глубинном строении ОС, в частности интерпретации сейсмического разреза 1-ЕВ и потенциальных полей. Модель иллюстрирует пример сопряженного взаимодействия различных геодинамических факторов и объясняет причины длительного формирования ОС на протяжении всего палеопротерозоя, включая периоды интенсивного прогибания и магматизма, инверсии составляющих Онежский прогиб локальных бассейнов и деформации палеопротерозойских толщ. При формировании ОС большое значение имели сдвиговые дислокации, проявленные в пределах имбрикационного веера Центрально-Карельской зоны сдвига, контролирующего позицию этой структуры. Сдвиговые перемещения были сопряжены с вращением крупного блока, расположенного западнее ОС, что привело к ротационно-инденторному взаимодействию смежных блоков и компенсационному сосуществованию областей транспрессии и транстенсии вдоль разделяющей их зоны сдвига. Компенсационный динамический механизм проявился и в коровых слоях основания ОС. Горизонтальное течение и отток среднекоровых масс из области депрессии компенсировались формированием глубинных надвиговых дуплексов и поднятий в обрамлении депрессии, а также растяжением верхней коры с развитием систем пологих дилатансионных сбросов. Последовательная пропагация этих сбросов, динамически сопряженных со сдвиговыми нарушениями имбрикационного веера Центрально-Карельской зоны, контролировала особенности формирования и миграцию бассейнов ОС в южном направлении, а также проявления магматизма и силлогенеза. Многоярусное субгоризонтальное течение маловязких пород в основании и внутри разреза ОС, проявившееся на фоне сдвиговых дислокаций, привело к развитию гребневидной и диапироподобной складчатости. Процессы формирования ОС проходили на фоне высокой активности мантийных плюмов и астеносферных диапиров. Одним из факторов их развития и локализации были явления относительной декомпрессии в пределах имбрикационного веера Центрально-Карельской зоны сдвига

    New PNM Mutation in SUP35

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    A number of [PSI+]-no-more (PNM) mutations, eliminating [PSI+] prion, were previously described in SUP35. In this study, we designed and analyzed a new PNM mutation based on the parallel in-register β-structure of Sup35 prion fibrils suggested by the known experimental data. In such an arrangement, substitution of non-charged residues by charged ones may destabilize the fibril structure. We introduced Q33K/A34K amino acid substitutions into the Sup35 protein, corresponding allele was called sup35-M0. The mutagenized residues were chosen based on ArchCandy in silico prediction of high inhibitory effect on the amyloidogenic potential of Sup35. The experiments confirmed that Sup35-M0 leads to the elimination of [PSI+] with high efficiency. Our data suggested that the elimination of the [PSI+] prion is associated with the decreased aggregation properties of the protein. The new mutation can induce the prion with very low efficiency and is able to propagate only weak [PSI+] prion variants. We also showed that Sup35-M0 protein co-aggregates with the wild-type Sup35 in vivo. Moreover, our data confirmed the utility of the strategy of substitution of non-charged residues by charged ones to design new mutations to inhibit a prion formationRFBR grant 19-04-00173, RFBR grant 17-54-150002, and PRC CNRS grant PRC1524,18-34-00536, RSF grant 18-14-0005

    Application of Molecular Typing Methods for Analysis of Strains of Rickettsiae of the Spotted Fever Group and Rabies Virus

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    50 strains of spotted fever group (SFG) rickettsiae and 36 lyssaviruses strains from the collection of Omsk Research Institute of Natural Focus Infections were identified and typed using the approaches of molecular biology, epidemiology and bioinformatics. The taxonomic status of the studied cultures of SFG rickettsiae was identified. Zonation of the Russian Federation territories according to the spread of SFG pathogenic rickettsiae in their hosts - ixodic ticks was carried out. Lyssaviruses distribution in the territory of Siberia was considered

    Rabies re-emergence after long-term disease freedom (Amur Oblast, Russia)

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    Retrospective descriptive epizootological study was conducted in the Amur Oblast (Russian Far East), where a rabies outbreak was reported in 2018. The aim of the study was to analyze probable routes of rabies introduction and features of its spatial and temporal spread in the territory that remained free from this infection from 1972 to 2018. In 2018–2021, altogether 1,416 animals were examined for the infection with the rabies virus. Forty-seven animal rabies cases were confirmed; the proportion of wild animals (Vulpes vulpes, Nyctereutes procyonoides, Canis lupus) amounted to 66%. The first cases were detected within 30 km from the state border with China. Nucleotide sequences of the nucleoprotein gene of three rabies virus isolates were determined and their belonging to the Arctic-like-2 genetic lineage was established. Genetically closest rabies virus isolates have been found in Heilongjiang Province (China, 2011, 2018) and Jewish Autonomous Oblast (Russia, 1980). GIS and open Earth remote sensing data were used to map the rabies cases. After 2018, the epizootic spread within the forest-steppe landscapes of the Zeya-Bureya Plain, where human and animal rabies cases had been earlier reported (until 1972). The front of the epizootic spread in a north-eastern direction at an average speed of 59 (16–302) km during one epizootic cycle. The introduction of the rabies virus was most likely along the Amur River valley from downstream regions of Russia and China that are rabies infected

    Диагностика и мониторинг нейронального повреждения при тяжелой черепно-мозговой травме

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    Objective: to search for an accessible, valid, and easy-to-use method for the diagnosis and monitoring of a neuronal lesion in severe brain injury (SBI). Subjects and methods. Thirty-three patients aged 18—55 years with isolated SBI (the Glasgow coma scores for admission consciousness were 6±2) were examined; the serum content of neuron-specific protein S-100B was further analyzed. Results and discussion. The cell damage marker concentration was substantially increased in the acute period of brain injury. When the pathological process followed a favorable course, S-100B was considerably decreased just on day 2 of the disease. When the changes were negative, S-100B concentrations remained virtually unchanged or even increased, which was indicative of secondary brain reperfusion/ischemic lesions. The mean baseline marker level varied with the type of brain injury diagnosed by computed tomography; the highest figures being noted in the groups where significant brain tissue lesion was detected. Key words: severe brain injury, prognosis, S-100B protein.Цель исследования — поиск доступного, надежного и простого метода диагностики и мониторинга нейронального повреждения при ТЧМТ. Материалы и методы. Проведено обследование 33 пациентов с изолированной ТЧМТ в возрасте 18—55 лет (уровень сознания при поступлении в стационар 6±2 балла по ШКГ), с последующим анализом содержания нейронспецифического протеина S-100В в сыворотке крови. Результаты и обсуждение. Концентрация маркера клеточного повреждения значительно повышалась в остром периоде черепно-мозговой травмы. При благоприятном течении патологического процесса уровень S-100В значительно снижался уже на 2-е сутки болезни. При отрицательной динамике концентрация S-100В оставалась практически неизменной или даже повышалась, что свидетельствовало о вторичных реперфузионных повреждениях головного мозга. Показано, что средние значения начального уровня маркера различались в зависимости от вида ЧМТ, диагностированного КТ, причем наибольшие цифры отмечались в группах, где выявлялось значительное повреждение мозговой ткани. Ключевые слова: тяжелая черепно-мозговая травма, прогноз, белок S-100В
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