Kazan Federal University

About: Kazan Federal University is a education organization based out in Kazan’, Russia. It is known for research contribution in the topics: Population & Chemistry. The organization has 9868 authors who have published 14390 publications receiving 135726 citations. The organization is also known as: Kazan (Volga region) Federal University & Kazan State University.

Internal protein dynamics on ps to μs timescales as studied by multi-frequency (15)N solid-state NMR relaxation.

Abstract: A comprehensive analysis of the dynamics of the SH3 domain of chicken alpha-spectrin is presented, based upon 15N T1 and on- and off-resonance T1ρ relaxation times obtained on deuterated samples with a partial back-exchange of labile protons under a variety of the experimental conditions, taking explicitly into account the dipolar order parameters calculated from 15N–1H dipole–dipole couplings. It is demonstrated that such a multi-frequency approach enables access to motional correlation times spanning about 6 orders of magnitude. We asses the validity of different motional models based upon orientation autocorrelation functions with a different number of motional components. We find that for many residues a “two components” model is not sufficient for a good description of the data and more complicated fitting models must be considered. We show that slow motions with correlation times on the order of 1–10 μs can be determined reliably in spite of rather low apparent amplitudes (below 1 %), and demonstrate that the distribution of the protein backbone mobility along the time scale axis is pronouncedly non-uniform and non-monotonic: two domains of fast (τ 10−6 s) we observe a sharp ~1 order of magnitude decrease of the apparent motional amplitudes. Such a distribution obviously reflects different nature of backbone motions on different time scales, where the slow end may be attributed to weakly populated “excited states.” Surprisingly, our data reveal no clearly evident correlations between secondary structure of the protein and motional parameters. We also could not notice any unambiguous correlations between motions in different time scales along the protein backbone emphasizing the importance of the inter-residue interactions and the cooperative nature of protein dynamics.

Interplay of charge density wave and multiband superconductivity in layered quasi-two-dimensional materials: The case of 2 H -Nb S 2 and 2 H -Nb Se 2

Abstract: Despite intense efforts on all known quasi-two-dimensional superconductors, the origin and exact boundary of the electronic orderings, particularly charge density waves and superconductivity, are still attractive problems with several open questions. Here, in order to reveal how the superconducting gap evolves, we report on high quality complementary measurements of magneto-optical imaging, specific heat, magnetic susceptibility, resistivity measurements, Andreev spectroscopy, and London penetration depth ${\ensuremath{\lambda}}_{ab}(T)$ measurements supplemented with theoretical calculations for $2\mathrm{H}\text{\ensuremath{-}}\mathrm{Nb}{\mathrm{Se}}_{2}$ and $2\mathrm{H}\text{\ensuremath{-}}\mathrm{Nb}{\mathrm{S}}_{2}$ single crystals. The temperature dependence of ${\ensuremath{\lambda}}_{ab}(T)$ calculated from the lower critical field and Andreev spectroscopy can be well described by using a two-band model with $s$-wave-like gaps. The effect of pressure on the superconducting gap of both systems illustrates that both bands are practically affected. Upon compression, the Fermi surfaces do not change significantly, and the nesting remains almost unaffected compared to that at ambient condition. However, a strong bending in the upper critical fields (${H}_{\mathrm{c}2}$) curves is obtained under pressure and support the presence of a strong Pauli paramagnetic effect. In $\mathrm{Nb}{\mathrm{Se}}_{2}$, using a two-band model with $s$-wave-like gaps, the temperature dependence ${H}_{\mathrm{c}2}(T)$ can be properly described. In contrast to that, the behavior of ${H}_{\mathrm{c}2}$ for $\mathrm{Nb}{\mathrm{S}}_{2}$ is ruled by the spin paramagnetic effect. The estimated values of the penetration depth at $T=0\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ confirm that $\mathrm{Nb}{\mathrm{Se}}_{2}$ and $\mathrm{Nb}{\mathrm{S}}_{2}$ superconductors depart from a Uemura-style relationship between ${T}_{\mathrm{c}}$ with ${\mathbit{\ensuremath{\lambda}}}_{ab}^{\ensuremath{-}2}(T)$, the in-plane superconducting penetration depth.

ARID1A spatially partitions interphase chromosomes.

Abstract: ARID1A, a subunit of the SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin-remodeling complex, localizes to both promoters and enhancers to influence transcription. However, the role of ARID1A in higher-order spatial chromosome partitioning and genome organization is unknown. Here, we show that ARID1A spatially partitions interphase chromosomes and regulates higher-order genome organization. The SWI/SNF complex interacts with condensin II, and they display significant colocalizations at enhancers. ARID1A knockout drives the redistribution of condensin II preferentially at enhancers, which positively correlates with changes in transcription. ARID1A and condensin II contribute to transcriptionally inactive B-compartment formation, while ARID1A weakens the border strength of topologically associated domains. Condensin II redistribution induced by ARID1A knockout positively correlates with chromosome sizes, which negatively correlates with interchromosomal interactions. ARID1A loss increases the trans interactions of small chromosomes, which was validated by three-dimensional interphase chromosome painting. These results demonstrate that ARID1A is important for large-scale genome folding and spatially partitions interphase chromosomes.

Early to Middle Jurassic history of the southern Siberian continent (Transbaikalia) recorded in sediments of the Siberian Craton: Sm-Nd and U-Pb provenance study

Abstract: The deposition of Jurassic continental sedimentary rocks in the southern part of the Siberian continent (Transbaikalia) reflects the intensification of tectonomagmatic processes in this region The most likely cause of this intensification was associated with the formation and development of the Mongol-Okhotsk orogenic belt The latter was controlled in its turn by the closure of the Mongol-Okhotsk Ocean, for which the timing of its closure, as well as the formation of a collisional orogeny and its subsequent collapse are still under debate We address this question by studying sediments of the Irkutsk Basin, which were deposited in a short time span in the Middle Jurassic, most likely during the Aalenian The Sm-Nd data for bulk-rock sandstones demonstrate that the youngest samples of the Irkutsk Basin are characterized by a prominent contribution from a source within the juvenile crust of the Mongol-Okhotsk orogenic belt U-Pb detrital zircon ages concur with the Sm-Nd data and show that the amount of material derived from local cratonic sources decreased in time whereas material from the remote Transbaikalian sources increased Our data provide evidence that mountain growth in Transbaikalia intensified rapidly close to the Early and Middle Jurassic boundary

3D modelling and simulation of a crawler robot in ROS/Gazebo

Abstract: Modelling and animation of crawler UGV's caterpillars is a complicated task, which has not been completely resolved in ROS/Gazebo simulators. In this paper, we proposed an approximation of track-terrain interaction of a crawler UGV, perform modelling and simulation of Russian crawler robot "Engineer" within ROS/Gazebo and visualize its motion in ROS/RViz software. Finally, we test the proposed model in heterogeneous robot group navigation scenario within uncertain Gazebo environment.