117 research outputs found

    «ВАВИЛОН ЖИВ. ВАВИЛОН БУДЕТ ЖИТЬ» (К 130-ЛЕТИЮ СО ДНЯ РОЖДЕНИЯ АКАДЕМИКА Н.И. ВАВИЛОВА)

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    The N.I. Vavilov’s contribution into national and world’s science including plant systematic, plant genetics and breeding, plant immunity and introduction was described in the article. His scientific elaborations on distribution of plant species and varieties on the earth and in regions and centers of origin of cultivated plants, where they intensively formed themselves were given in the article. The scientific significance and practical use of plant genetic resources and ways for their mobilization were regarded in the paper. The further development of Vavilov’s ideas is a tribute of gratitude to rich heritage having been preserved for descendants. Описан вклад Н.И. Вавилова в развитие отечественной и мировой науки, включая систематику, генетику, селекцию, иммунитет и интродукцию. Приведены научные разработки ученого о распределении сортовых и видовых ресурсов на земном шаре и районах (центрах) интенсивного их формообразования. Показана значимость растительных ресурсов мира и пути их мобилизации с целью практического использования. Дальнейшее развитие идей Н.И. Вавилова – дань благодарности за богатое наследие, оставленное потомкам.

    Influence of cratonic lithosphere on the formation and evolution of flat slabs : insights from 3-D time-dependent modeling.

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    Several mechanisms have been suggested for the formation of flat slabs including buoyant features on the subducting plate, trenchward motion and thermal or cratonic structure of the overriding plate. Analysis of episodes of flat subduction indicate that not all flat slabs can be attributed to only one of these mechanisms and it is likely that multiple mechanisms work together to create the necessary conditions for flat slab subduction. In this study we examine the role of localized regions of cratonic lithosphere in the overriding plate in the formation and evolution of flat slabs. We explicitly build on previous models, by using time-dependent simulations with three-dimensional variation in overriding plate structure. We find that there are two modes of flat subduction: permanent underplating occurs when the slab is more buoyant (shorter or younger), while transient flattening occurs when there is more negative buoyancy (longer or older slabs). Our models show how regions of the slab adjacent to the subcratonic flat portion continue to pull the slab into the mantle leading to highly contorted slab shapes with apparent slab gaps beneath the craton. These results show how the interpretation of seismic images of subduction zones can be complicated by the occurrence of either permanent or transient flattening of the slab, and how the signature of a recent flat slab episode may persist as the slab resumes normal subduction. Our models suggest that permanent underplating of slabs may preferentially occur below thick and cold lithosphere providing a built-in mechanism for regeneration of cratons

    The TREAT-NMD DMD Global Database: analysis of more than 7,000 Duchenne muscular dystrophy mutations.

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    Analyzing the type and frequency of patient-specific mutations that give rise to Duchenne muscular dystrophy (DMD) is an invaluable tool for diagnostics, basic scientific research, trial planning, and improved clinical care. Locus-specific databases allow for the collection, organization, storage, and analysis of genetic variants of disease. Here, we describe the development and analysis of the TREAT-NMD DMD Global database (http://umd.be/TREAT_DMD/). We analyzed genetic data for 7,149 DMD mutations held within the database. A total of 5,682 large mutations were observed (80% of total mutations), of which 4,894 (86%) were deletions (1 exon or larger) and 784 (14%) were duplications (1 exon or larger). There were 1,445 small mutations (smaller than 1 exon, 20% of all mutations), of which 358 (25%) were small deletions and 132 (9%) small insertions and 199 (14%) affected the splice sites. Point mutations totalled 756 (52% of small mutations) with 726 (50%) nonsense mutations and 30 (2%) missense mutations. Finally, 22 (0.3%) mid-intronic mutations were observed. In addition, mutations were identified within the database that would potentially benefit from novel genetic therapies for DMD including stop codon read-through therapies (10% of total mutations) and exon skipping therapy (80% of deletions and 55% of total mutations)

    Bottom-Water Conditions in a Marine Basin after the Cretaceous–Paleogene Impact Event: Timing the Recovery of Oxygen Levels and Productivity

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    An ultra-high-resolution analysis of major and trace element contents from the Cretaceous–Paleogene boundary interval in the Caravaca section, southeast Spain, reveals a quick recovery of depositional conditions after the impact event. Enrichment/depletion profiles of redox sensitive elements indicate significant geochemical anomalies just within the boundary ejecta layer, supporting an instantaneous recovery –some 102 years– of pre-impact conditions in terms of oxygenation. Geochemical redox proxies point to oxygen levels comparable to those at the end of the Cretaceous shortly after impact, which is further evidenced by the contemporary macrobenthic colonization of opportunistic tracemakers. Recovery of the oxygen conditions was therefore several orders shorter than traditional proposals (104–105 years), suggesting a probable rapid recovery of deep-sea ecosystems at bottom and in intermediate waters.This research was supported by Projects CGL2009-07603, CGL2008-03007, CGL2012-33281 and CGL2012-32659 (Secretaría de Estado de I+D+I, Spain), Projects RNM-3715 and RNM 05212, and Research Groups RNM-178 and 0179 (Junta de Andalucía)

    Stochastic Inversion of P-to-S Converted Waves for Mantle Composition and Thermal Structure: Methodology and Application

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    We present a new methodology for inverting P‐to‐S receiver function (RF) waveforms directly for mantle temperature and composition. This is achieved by interfacing the geophysical inversion with self‐consistent mineral phase equilibria calculations from which rock mineralogy and its elastic properties are predicted as a function of pressure, temperature, and bulk composition. This approach anchors temperatures, composition, seismic properties, and discontinuities that are in mineral physics data, while permitting the simultaneous use of geophysical inverse methods to optimize models of seismic properties to match RF waveforms. Resultant estimates of transition zone (TZ) topography and volumetric seismic velocities are independent of tomographic models usually required for correcting for upper mantle structure. We considered two end‐member compositional models: the equilibrated equilibrium assemblage (EA) and the disequilibrated mechanical mixture (MM) models. Thermal variations were found to influence arrival times of computed RF waveforms, whereas compositional variations affected amplitudes of waves converted at the TZ discontinuities. The robustness of the inversion strategy was tested by performing a set of synthetic inversions in which crustal structure was assumed both fixed and variable. These tests indicate that unaccounted‐for crustal structure strongly affects the retrieval of mantle properties, calling for a two‐step strategy presented herein to simultaneously recover both crustal and mantle parameters. As a proof of concept, the methodology is applied to data from two stations located in the Siberian and East European continental platforms.This work was supported by a grant from the Swiss National Science Foundation (SNF project 200021_159907). B. T. was funded by a Délégation CNRS and Congé pour Recherches et Conversion Thématique from the Université de Lyon to visit the Research School of Earth Sciences (RSES), The Australian National University (ANU). B. T. has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement 79382

    Untangling the chemical evolution of Titan's atmosphere and surface–from homogeneous to heterogeneous chemistry

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    The arrival of the Cassini-Huygens probe at Saturn's moon Titan - the only Solar System body besides Earth and Venus with a solid surface and a thick atmosphere with a pressure of 1.4 atm at surface level - in 2004 opened up a new chapter in the history of Solar System exploration. The mission revealed Titan as a world with striking Earth-like landscapes involving hydrocarbon lakes and seas as well as sand dunes and lava-like features interspersed with craters and icy mountains of hitherto unknown chemical composition. The discovery of a dynamic atmosphere and active weather system illustrates further the similarities between Titan and Earth. The aerosol-based haze layers, which give Titan its orange-brownish color, are not only Titan's most prominent optically visible features, but also play a crucial role in determining Titan's thermal structure and chemistry. These smog-like haze layers are thought to be very similar to those that were present in Earth's atmosphere before life developed more than 3.8 billion years ago, absorbing the destructive ultraviolet radiation from the Sun, thus acting as 'prebiotic ozone' to preserve astrobiologically important molecules on Titan. Compared to Earth, Titan's low surface temperature of 94 K and the absence of liquid water preclude the evolution of biological chemistry as we know it. Exactly because of these low temperatures, Titan provides us with a unique prebiotic 'atmospheric laboratory' yielding vital clues - at the frozen stage - on the likely chemical composition of the atmosphere of the primitive Earth. However, the underlying chemical processes, which initiate the haze formation from simple molecules, have been not understood well to date

    НЕЙРОЭНДОКРИННЫЕ ОПУХОЛИ ШЕЙКИ МАТКИ

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    The purpose of the study was to summarize the available data on etiology, diagnosis, clinical symptoms and signs as well as on various approaches to the treatment of neuroendocrine cervical tumors.Material and Methods. The relevant sources were searched in the PubMed and cochrane Library systems, and publications from 1980 to 2019 were analyzed, 53 of which were used to write this review. We also included 6 case reports from N.N. Petrov National Research Center of Oncology.Results. Neuroendocrine tumors (NETs) are extremely rare and aggressive malignancies of the female genital tract, among which NETs of the cervix are the most common. Due to the rarity of these tumors, there are currently no treatment standards based on prospective, well-planned clinical trials. For these reasons, NETs present a significant therapeutic challenge for clinicians. Case reports. Six patients ranged in age from 32 to 71 years, with a median age of 46 years, were diagnosed with large-cell neuroendocrine carcinoma (4 patients) and small-cell neuroendocrine carcinoma (2 patients). One patient with stage IIIA dropped out of the follow-up schedule. Out of 5 followed up patients, 2 patients with stage IIIA and IIB died of disease progression after 6 and 11 months, respectively. One patient with stage IB1 is in remission for 16 months. Two patients with stage IIB continue to receive primary treatment.Conclusion. Neuroendocrine carcinoma of the cervix is a rare variant of cervical cancer. The choice of treatment options is decided only by a multidisciplinary team of doctors, and further research is required. Цель исследования – обобщение имеющихся данных об особенности этиологии и диагностики, клинической картине и различных подходах в лечении нейроэндокринных опухолей шейки матки.Материал и методы. Поиск соответствующих источников производился в системах PubMed и cochrane Library, анализировались публикации с 1980 по 2019 г., 53 из которых были использованы для написания данного обзора. Также в публикации освещены 6 случаев собственных наблюдений в НМИЦ онкологии им. Н.Н. Петрова.Результаты. Нейроэндокринные опухоли (НЭО) являются крайне редкими и агрессивными злокачественными новообразованиями нижнего женского полового тракта, среди которых НЭО шейки матки встречаются чаще всего. Из-за редкости этих опухолей в настоящее время отсутствуют стандарты по лечению, основанные на проспективных, хорошо спланированных клинических исследованиях. По этим причинам НЭО представляют собой актуальную проблему для клиницистов. По данным собственных наблюдений, в НМИЦ онкологии им. Н.Н. Петрова средний возраст пациенток (n=6) составил 46 лет, возрастной диапазон 32–71 год; распределение по гистотипу: крупноклеточная нейроэндокринная карцинома – 4, мелкоклеточная нейроэндокринная карцинома – 2 пациентки. Одна пациентка с IIIA стадией выбыла из наблюдения; из 5 прослеженных 2 пациентки с IIIA и IIB стадией умерли от прогрессирования заболевания через 6 и 11 мес соответственно, 1 пациентка с IB1 стадией после комбинированного лечения находится в ремиссии 16 мес. Две пациентки со IIB стадией в настоящее время продолжают получать первичное лечение.Заключение. Основная клиническая проблема заключается в редкой встречаемости данного гистологического подтипа опухоли шейки матки. Выбор тактики лечения решается мультидисциплинарно и требует дальнейших исследований.

    A review of a quarter century of International Workshops on Seismic Anisotropy in the crust (0IWSA–12IWSA)

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