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Tatarstan Republic, Russia

Krinari G.A.,Kazan Federal University | Khramchenkov M.G.,Kazan Federal University | Rakhmatulina Y.,Tatarstan Academy of science
Russian Geology and Geophysics

A difference-spectrum method is proposed for the qualitative assessment of changes of illite-smectite structures accompanying the flooding of oil reservoirs. The method permits one to get an open system and reduce the application of procedures based on Markov's chain formalism. A computer simulation is made to obtain spectra by subtracting the spectrum of an ethylene glycol-saturated sample from the spectrum of an air-dried preparation throughout the entire range of concentrations of illite and smectite components with a short-range order factor R = 0 or R = 3.It has been established that only in the presence of filtration are the maximum and minimum of the spectra in the range of 12.5-9.4 A complicated by a number of local extrema, whose position is specified by the structure of intermediate phases. The flooding process first involves mixed-layer phases with R = 0, leading to a partial segregation of the structures into phase with one and two networks of interlayer H2O. When the secondary mica particles break, phases with R = 3 appear along the boundaries of nanoblocks, first only with 1 H2O and then only with 2 H2O in labile interspaces. Their coexistence with the phases R = 0 in the sample proves the existence of percolation effects due to two-phase filtration in the porous medium. The fully flooded reservoir is always dominated by a mechanical mixture of illite-smectite phases of different nature with R = 0 and with different ratios of components. Transformation of mica that can drastically reduce oil production begins long before the appearance of flooding zones, which are revealed by standard logging methods. © 2014 . Source

Spyrou M.A.,Max Planck Institute for the Science of Human History | Tukhbatova R.I.,Kazan Federal University | Feldman M.,Max Planck Institute for the Science of Human History | Drath J.,University of Tubingen | And 11 more authors.
Cell Host and Microbe

Ancient DNA analysis has revealed an involvement of the bacterial pathogen Yersinia pestis in several historical pandemics, including the second plague pandemic (Europe, mid-14th century Black Death until the mid-18th century AD). Here we present reconstructed Y. pestis genomes from plague victims of the Black Death and two subsequent historical outbreaks spanning Europe and its vicinity, namely Barcelona, Spain (1300-1420 cal AD), Bolgar City, Russia (1362-1400 AD), and Ellwangen, Germany (1485-1627 cal AD). Our results provide support for (1) a single entry of Y. pestis in Europe during the Black Death, (2) a wave of plague that traveled toward Asia to later become the source population for contemporary worldwide epidemics, and (3) the presence of an historical European plague focus involved in post-Black Death outbreaks that is now likely extinct. © 2016 Elsevier Inc. Source

Khusainov A.,Kazan Federal University | Suleymanov D.,Tatarstan Academy of science
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

This paper describes a speech identification system for the Tatar, English and Russian languages. It also presents a newly created Tatar speech corpus, which is used for building a language model. The main idea is to investigate the potential of basic phonotactic approaches (i.e. PRLM-approach) when working with the Tatar language. The results indicate that the proposed system can be successfully employed for identifying the Tatar, English and Russian languages. © 2013 Springer International Publishing. Source

Askeyev O.V.,Tatarstan Academy of science | Sparks T.H.,University of Life Sciences in Poznan | Askeyev I.V.,Tatarstan Academy of science | Tishin D.V.,Kazan Federal University | Tryjanowski P.,University of Life Sciences in Poznan
Global Ecology and Biogeography

Aim To examine whether change in the timing of a large number of phenological events and their response to temperature differs between trophic levels during the period 1988-2008.Location In the vicinity of Kazan, Tatarstan Republic, Russia (55°45' N, 49°08' E).Methods Observations of the dates of first events of 22 plant phases, 8 insect phases, 3 herpetofauna phases and 26 migrant bird phases were examined using regression to assess changes over time and response to temperature. Differences between trophic levels were assessed using ANOVA.Results In comparison to studies from western Europe, relatively few phenological series (15) revealed a significant advance over time, but a much larger number (37), including all the herpetofauna and nearly all the plants, showed a response to temperature. Trends in birds were, on average, twice as great as those for plants, but plants had a significantly greater temperature response. Over the study period local temperatures had not risen significantly but some phenological change was still evident.Main conclusions Phenological change has been less marked in the eastern edge of Europe than in western and central Europe. This is compatible with a lack of significant local warming during the study period. A large number of species show strong responses to temperature so will be expected to advance if/when local temperatures do increase. In contrast to results from elsewhere in Europe, early events were not the most temperature responsive, suggesting local adaptation preventing precocious behaviour and the consequent dangers of sub-zero temperatures. © 2010 Blackwell Publishing Ltd. Source

Maric S.,University of Belgrade | Alekseyev S.,Russian Academy of Sciences | Snoj A.,University of Ljubljana | Askeyev O.,Tatarstan Academy of science | And 2 more authors.
Journal of Fish Biology

New concatenated mtDNA sequences (three genes; n = 22) of Siberian taimen Hucho taimen primarily from west Siberian and European regions of the species' range were added to 12 previously published sequences to provide a phylogeographic overview of the species. European samples show only very minor divergence from west Siberian populations, supporting a late Pleistocene expansion from Siberia into the Urals, with no particular relation to the Danube River basin huchen Hucho hucho as once hypothesized. The disjunct distribution of the genus is most likely based on an early Pleistocene vicariant event. © 2014 The Fisheries Society of the British Isles. Source

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