Methodist school at present: reviving traditions in market conditions

The article is devoted to the shortage of Methodists of a new format. The idea of reviving the schools of Methodists has been put forward as a solution to the contradiction between the demand for Methodists al consulting and the insufficient number of experts prepared for methodical work. The authors compare the real requirements for the Methodists and the formal qualification characteristics of the Meth-odists as one of the positions of teachers.Статья посвящена проблеме дефицита методистов нового формата. Выдвинута идея возрождения школ методистов как решение противоречия между спросом на методический консалтинг и недостаточным количеством экспертов, подготовленных к методической работе

Response of Seven Crystallographic Orientations of Sapphire Crystals to Shock Stresses of 16 to 86 GPa

Shock-wave profiles of sapphire (single-crystal Al2O3) with seven crystallographic orientations were measured with time-resolved VISAR interferometry at shock stresses in the range 16 to 86 GPa. Shock propagation was normal to the surface of each cut. The angle between the c-axis of the hexagonal crystal structure and the direction of shock propagation varied from 0 for c-cut up to 90 degrees for m-cut in the basal plane. Based on published shock-induced transparencies, shock-induced optical transparency correlates with the smoothness of the shock-wave profile. The ultimate goal was to find the direction of shock propagation in sapphire that is most transparent as a window. Particle velocity histories were recorded at the interface between a sapphire crystal and a LiF window. In most cases measured wave profiles are noisy as a result of heterogeneity of deformation. Measured values of Hugoniot Elastic Limits (HELs) depend on direction of shock compression and peak shock stress. The largest HEL values were recorded for shock loading along the c-axis and perpendicular to c along the m-direction. Shock compression along the m- and s-directions is accompanied by the smallest heterogeneity of deformation and the smallest rise time of the plastic shock wave. m- and s-cut sapphire most closely approach ideal elastic-plastic flow, which suggests that m- and s-cut sapphire are probably the orientations that remains most transparent to highest shock pressures. Under purely elastic deformation sapphire has very high spall strength, which depends on load duration and peak stress. Plastic deformation of sapphire causes loss of its tensile strength.Comment: 18 pages, 18 figure

Обработка ретранслированных навигационных сигналов глобальной навигационной спутниковой системы GPS в задаче оценивания полного электронного содержания в ионосфере

Objectives. For a method for estimating the total electron content in the ionosphere based on the retransmission of the L1 GPS navigation signal by a repeater nanosatellite (SR) to the frequencies of 150/400 MHz allocated for geophysical research and their reception at a ground-based receiving point (RP), it is necessary to develop the algorithms for coherent accumulation of received relayed signals and measurement of the difference between their delays at observation intervals up to a few seconds.Methods. The proposed algorithms provide phase demodulation of the received signals at each of the relay frequencies in accordance with the dynamics of the mutual spatial movement of the navigation satellite (NS), SR and RP; multiplying the result by the estimate of the navigation message combined time delay, generated by the receiver of the direct navigation signal on the NS-RP route, intra-period processing over the entire duration of the observation in a filter matched with the signal of the navigation satellite, and inter-period coherent accumulation of the results of intra-period processing at a single-valued range interval. Coherent accumulation, taking into account a random uncontrolled shift in the frequency of the retransmitted signal, is implemented by discrete Fourier transform of the vectors formed for each resolution element in the delay time from inter-period readings of the results of intra-period processing, taking into account the range migration during the mutual movement of the NS, SR and RP.Results. It is shown that by the output signal of the coherent accumulator makes it is possible to detect retransmitted signals at each of the retransmission frequencies, to measure accurately the difference in delay times, and estimate the total electron content on the SR-RP path. The results of modeling are presented, confirming the efficiency of the proposed algorithms in estimating the total electron content on the SR-RP route.Conclusion. An algorithm for coherent accumulation of received retransmitted signals and measurement of the difference between their delays is developed, and its simulation is performed. The algorithm can be used for estimating TEC based on the retransmission of signals from GPS.Цели. Для способа оценивания полного электронного содержания в ионосфере на основе ретрансляции навигационного сигнала L1 GPS наноспутником-ретранслятором (СР) на выделенные для геофизических исследований частоты 150/400 МГц и их приема на наземном приемном пункте (ПП) необходимо разработать алгоритмы когерентного накопления принимаемых ретранслированных сигналов и измерения разности их задержек на интервалах наблюдения продолжительностью до единиц секунды.Методы. Предлагаемые алгоритмы предусматривают фазовую демодуляцию принимаемых сигналов на каждой из частот ретрансляции в соответствии с динамикой взаимного пространственного перемещения навигационного спутника (НС), СР и ПП; умножение результата на совмещенную по времени задержки оценку навигационного сообщения, формируемую приемником прямого навигационного сигнала на трассе НС - ПП, внутрипериодную обработку на всей длительности наблюдения в согласованном с сигналом НС фильтре и междупериодное когерентное накопление результатов внутрипериодной обработки на интервале однозначной дальности. Когерентное накопление с учетом случайного неконтролируемого сдвига по частоте ретранслированного сигнала реализуется путем дискретного преобразования Фурье векторов, сформированных для каждого элемента разрешения по времени задержки из междупериодных отсчетов результатов внутрипериодной обработки с учетом миграции дальности при взаимном перемещении НС, СР и ПП.Результаты. Показано, что по выходному сигналу когерентного накопителя возможно обнаружение ретранслированных сигналов на каждой из частот ретрансляции, точное измерение разности времен задержек и оценивание полного электронного содержания на трассе СР - ПП. Приведены результаты моделирования, подтверждающие работоспособность предлагаемых алгоритмов при оценивании полного электронного содержания на трассе СР - ПП.Заключение. Разработан алгоритм когерентного накопления принимаемых ретранслированных сигналов и измерения разности их задержек, проведено его моделирование. Алгоритм может быть использован при определении ПЭС на основе ретрансляции сигналов глобальной навигационной спутниковой системы GPS

Entropy-Dominated Dissipation in Sapphire Shock-Compressed up to 400 GPa (4 Mbar)

Sapphire (single-crystal Al2O3) is a representative Earth material and is used as a window and/or anvil in shock experiments. Pressure, for example, at the core-mantle boundary is about 130 gigapascals (GPa). Defects induced by 100-GPa shock waves cause sapphire to become opaque, which precludes measuring temperature with thermal radiance. We have measured wave profiles of sapphire crystals with several crystallographic orientations at shock pressures of 16, 23, and 86 GPa. At 23 GPa plastic-shock rise times are generally quite long (~100 ns) and their values depend sensitively on the direction of shock propagation in the crystal lattice. The long rise times are probably caused by the high strength of inter-atomic interactions in the ordered three-dimensional sapphire lattice. Our wave profiles and recent theoretical and laser-driven experimental results imply that sapphire disorders without significant shock heating up to about 400 GPa, above which Al2O3 is amorphous and must heat. This picture suggests that the characteristic shape of shock compression curves of many Earth materials at 100 GPa pressures is caused by a combination of entropy and temperature.Comment: 12 pages, 4 figure

Preparation of NZP-type Ca0.75+0.5xZr1.5Fe0.5(PO4)3-x(SiO4)x powders and ceramic, thermal expansion behavior

Ca0.75+0.5xZr1.5Fe0.5(PO4)3–x(SiO4)x (x = 0–0.5) solid solutions have been synthesized by a sol–gel process and characterized by X-ray diffraction, IR spectroscopy, and differential scanning calorimetry. As expected, the synthesized phosphatosilicates crystallize in a NaZr2(PO4)3-type structure (trigonal symmetry, sp. gr. R3c). The thermal expansion of the solid solutions has been studied by high-temperature Xray diffraction in the temperature range from 25 to 800°C. Their thermal expansion parameters have been calculated and analyzed as functions of composition. Highdensity ceramics based on the Ca0.875Zr1.5Fe0.5(PO4)2.75(SiO4)0.25 phosphatosilicate have been produced by spark plasma sintering and their structure and properties have been studied in detail.This work was supported by the Russian Science Foundation, project no. 16-13-10464: Advanced ceramic like mineral materials with improved and adjustable service characteristics: design, synthesis, study.Peer reviewe

Способ оценивания полного электронного содержания в ионосфере на основе ретрансляции сигналов глобальной навигационной спутниковой системы GPS

Objectives. The problem of developing hardware effective method for estimating the total electron content in the ionosphere based on retransmission of the L1, L2 signals of the global navigation satellite system GPS using a repeater nanosatellite is solved.Methods. It is shown that with the retransmission of L1, L2 signals at frequencies of 150/400 MHz allocated for geophysical research, a coherent multi-position radar system is formed, including navigation satellites (NS) – signal sources, repeater nanosatellite (SR) and ground receiving points (RP). The delay time and phase of the four received signals contain the information about the total TEC on the propagation paths NS – SR and SR – RP. It is shown that due to retransmission and subsequent processing, it is possible to isolate TECs on each of the propagation paths as well as determination of the coordinates of the SR.Results. The content of the method, the procedure for evaluating TEC based on the results of processing the relayed signals, and the technical requirements for the relay equipment are determined. The accuracy characteristics of the proposed method are obtained. Simulation results are given.Conclusion. The information presented in the article may be useful for specialists and researchers who interested in the issues of radio tomographic research of the ionosphere and forecasting hazardous natural phenomena.Цели. Решается задача разработки эффективного по аппаратурным затратам способа оценивания полного электронного содержания в ионосфере на основе ретрансляции сигналов глобальной навигационной спутниковой системы GPS на двух частотах L1, L2 когерентных сигналов с использованием малогабаритного наноспутника-ретранслятора.Методы. Показано, что при ретрансляции навигационных сигналов на выделенные для геофизических исследований частоты 150/400 МГц образуется когерентная многопозиционная радиолокационная система, включающая навигационные спутники (НС) – источники сигналов, наноспутник-ретранслятор (СР) и наземные приемные пункты (ПП). Время задержки и фазы четырех принимаемых сигналов содержат информацию о суммарном полном электронном содержании на трассах распространения НС – СР и СР – ПП. За счет последующей обработки сигналов возможно выделение полного электронного содержания на каждой из трасс распространения, а также нахождение координат CР.Результаты. Определены способ и порядок оценивания полного электронного содержания по результатам обработки ретранслированных сигналов и технические требования к аппаратуре ретрансляции. Представлены характеристики точности предлагаемого метода и результаты моделирования.Заключение. Приведенные в статье сведения могут быть полезны для специалистов и исследователей, интересующихся вопросами радиотомографического изучения ионосферы и прогнозирования опасных природных явлений

Neonatal and adult recent thymic emigrants produce IL-8 and express complement receptors CR1 and CR2

The maintenance of peripheral naive T lymphocytes in humans is dependent on their homeostatic division, not continuing emigration from the thymus, which undergoes involution with age. However, postthymic maintenance of naive T cells is still poorly understood. Previously we reported that recent thymic emigrants (RTEs) are contained in CD31+CD25- naive T cells as defined by their levels of signal joint T cell receptor rearrangement excision circles (sjTRECs). Here, by differential gene expression analysis followed by protein expression and functional studies, we define that the naive T cells having divided the least since thymic emigration express complement receptors (CR1 and CR2) known to bind complement C3b- and C3d-decorated microbial products and, following activation, produce IL-8 (CXCL8), a major chemoattractant for neutrophils in bacterial defense. We also observed an IL-8-producing memory T cell subpopulation coexpressing CR1 and CR2 and with a gene expression signature resembling that of RTEs. The functions of CR1 and CR2 on T cells remain to be determined, but we note that CR2 is the receptor for Epstein-Barr virus, which is a cause of T cell lymphomas and a candidate environmental factor in autoimmune disease

SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion

Abstract: The B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha)1. In vitro, B.1.617.2 is sixfold less sensitive to serum neutralizing antibodies from recovered individuals, and eightfold less sensitive to vaccine-elicited antibodies, compared with wild-type Wuhan-1 bearing D614G. Serum neutralizing titres against B.1.617.2 were lower in ChAdOx1 vaccinees than in BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies to the receptor-binding domain and the amino-terminal domain. B.1.617.2 demonstrated higher replication efficiency than B.1.1.7 in both airway organoid and human airway epithelial systems, associated with B.1.617.2 spike being in a predominantly cleaved state compared with B.1.1.7 spike. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralizing antibody, compared with that of wild-type spike. We also observed that B.1.617.2 had higher replication and spike-mediated entry than B.1.617.1, potentially explaining the B.1.617.2 dominance. In an analysis of more than 130 SARS-CoV-2-infected health care workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune-evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era