20 research outputs found

    Tectonic sources of caucasus strong earthquakes

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    International audienceThe method called "phase cone" is developed in order to define the location, time of arising and velocity of the earthquakes initiating the low-speed interference stress waves. From the data of the strong earthquakes with M?6.0 in Caucasus region during 1900-1992, the immigrators or tectonic sources of low-speed waves were revealed, interference nodes of which had initiated 19 earthquakes out of total 33. The time of arising of low-speed stress waves or periods of awaking of tectonic sources is defined. The velocities of constant initiative waves for all events were calculated. Its average value is equal to 2.97km per year

    Relatively small earthquakes of Javakheti Highland as the precursors of large earthquakes occuring in the Caucasus

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    International audienceJavakheti Highland is one of the most seismic active regions of the Caucasus. The majority of earthquakes observed throughout the region occur within this small area (f = 40.8° ? 41.8° ; l = 43.3° ? 44.3°). One can expect that exclusive seismic activity of Javakheti Highland testifies to global geophysical processes which take place throughout the Caucasus region. Based on the above-mentioned, of interest was to study variation with time of the number of earthquakes occurring in Javakheti region. We analysed some 695 relatively small earthquakes (2.5 M > 6.0 of the region which occurred in the same period. It was found that each large earthquake of the Caucasus is anticipated by clear precursor in a form of an anomalous change in the number of relatively small earthquakes in Javakheti Highland

    Connection of large earthquakes occurring moment with the movement of the Sun and the Moon and with the Earth crust tectonic stress character

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    It is acceptable that earthquakes certain exogenous (cosmic) triggering factors may exist in every seismoactive (s/a) region and in Caucasus among them. They have to correct earthquake occurring moment or play the triggering role in case when the region is at the limit of the critical value of the geological medium of course. <br><br> Our aim is to reveal some exogenous factors possible to initiate earthquakes, on example of Caucasus s/a region, taking into account that the region is very complex by the point of view of the tectonic stress distribution. <br><br> The compression stress directed from North to South (and vice versa) and the spread stress directed from East to West (and vice versa) are the main stresses acted in Caucasus region. No doubt that action of the smallest external stress may "work" as earthquakes triggering factor. <br><br> In the presented work the Moon and the Sun perturbations are revealed as initiative agents of earthquakes when the directions of corresponding exogenous forces coincide with the directions of the compression stress or the spreading tectonic stress in the region

    Early Pleistocene enamel proteome from Dmanisi resolves Stephanorhinus phylogeny

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    The sequencing of ancient DNA has enabled the reconstruction of speciation, migration and admixture events for extinct taxa. However, the irreversible post-mortem degradation2 of ancient DNA has so far limited its recovery—outside permafrost areas—to specimens that are not older than approximately 0.5 million years (Myr). By contrast, tandem mass spectrometry has enabled the sequencing of approximately 1.5-Myr-old collagen type I, and suggested the presence of protein residues in fossils of the Cretaceous period—although with limited phylogenetic use. In the absence of molecular evidence, the speciation of several extinct species of the Early and Middle Pleistocene epoch remains contentious. Here we address the phylogenetic relationships of the Eurasian Rhinocerotidae of the Pleistocene epoch, using the proteome of dental enamel from a Stephanorhinus tooth that is approximately 1.77-Myr old, recovered from the archaeological site of Dmanisi (South Caucasus, Georgia). Molecular phylogenetic analyses place this Stephanorhinus as a sister group to the clade formed by the woolly rhinoceros (Coelodonta antiquitatis) and Merck’s rhinoceros (Stephanorhinus kirchbergensis). We show that Coelodonta evolved from an early Stephanorhinus lineage, and that this latter genus includes at least two distinct evolutionary lines. The genus Stephanorhinus is therefore currently paraphyletic, and its systematic revision is needed. We demonstrate that sequencing the proteome of Early Pleistocene dental enamel overcomes the limitations of phylogenetic inference based on ancient collagen or DNA. Our approach also provides additional information about the sex and taxonomic assignment of other specimens from Dmanisi. Our findings reveal that proteomic investigation of ancient dental enamel—which is the hardest tissue in vertebrates, and is highly abundant in the fossil record—can push the reconstruction of molecular evolution further back into the Early Pleistocene epoch, beyond the currently known limits of ancient DNA preservation

    Can environment or allergy explain international variation in prevalence of wheeze in childhood?

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    Asthma prevalence in children varies substantially around the world, but the contribution of known risk factors to this international variation is uncertain. The International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two studied 8–12 year old children in 30 centres worldwide with parent-completed symptom and risk factor questionnaires and aeroallergen skin prick testing. We used multilevel logistic regression modelling to investigate the effect of adjustment for individual and ecological risk factors on the between-centre variation in prevalence of recent wheeze. Adjustment for single individual-level risk factors changed the centre-level variation from a reduction of up to 8.4% (and 8.5% for atopy) to an increase of up to 6.8%. Modelling the 11 most influential environmental factors among all children simultaneously, the centre-level variation changed little overall (2.4% increase). Modelling only factors that decreased the variance, the 6 most influential factors (synthetic and feather quilt, mother’s smoking, heating stoves, dampness and foam pillows) in combination resulted in a 21% reduction in variance. Ecological (centre-level) risk factors generally explained higher proportions of the variation than did individual risk factors. Single environmental factors and aeroallergen sensitisation measured at the individual (child) level did not explain much of the between-centre variation in wheeze prevalence

    Экзогенние Иницирующие Факторы Землетресений

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    Planets or planets couple special distribution on heavenly sphere is considered as earthquakes triggering factors. There are revealed sectors on heavenly sphere in which planets or planets couples being occurs maximal or minimal quantity of earthquakes.პლანეტების ან პლანეტათა წყვილების ცის თაღზე განსაკუთრებული განაწილება განიხილება, როგორც მიწისძვრათა ტრიგერული ფაქტორი. გამოვლენილია სექტორები, რომლებშიც პლანეტების ან პლანეტათა წყვილების მოხვედრისას მიწისძვრათა მაქსიმალური ან მინიმალური რაოდენობა ხდებაОсобое распределение планет или пар планет на небесном своде рассматривается как триггерный фактор землятрясений. Выявлены секторы на небеснои своде при нахождении в которых планет или пар планет происходит максимальное или минимильное количество землятрясений
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