220 research outputs found

    The Myth about Universal Higher Education: Russia in the International Context

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    This is the final version. Available from the National Research University Higher School of Economics (HSE) via the DOI in this recordIt is widely believed that higher education in Russia has become almost universal and more people go to universities compared to most European countries. In this paper we explore this issue empirically with the Russian and European census data and data from the Trajectories in Education and Careers (TREC), a longitudinal cohort study. According to the 2010 census, only 34% of people aged between 25 and 34 in Russia have university degrees, which is nearly the same as in most Eastern European countries and slightly fewer than in Western Europe. The TREC data show that only about 50% of 2012 ninthgrade graduates were university students in 2015. The expansion of higher education in Russia has been in line with the overall European trends. Similar to other countries, there have been changes to the gender composition of university students in Russia over the last two decades, with girls being more likely to attend university than boys. The analysis of social backgrounds of students with different educational trajectories reveals a considerable social inequality within the Russian education system. Eighty-four percent of school graduates with university-educated parents are admitted to university, as compared to only 32% of children from less-educated families. Graduation from ninth grade represents an educational fork that is crucial for inequality, as children from less socially advantaged families tend to opt for vocational education at this stage. Graduation from eleventh grade is a less important educational transition: at least 80% of high school students get admitted to university after graduating from 11th grade

    The PDZ Domain as a Complex Adaptive System

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    Specific protein associations define the wiring of protein interaction networks and thus control the organization and functioning of the cell as a whole. Peptide recognition by PDZ and other protein interaction domains represents one of the best-studied classes of specific protein associations. However, a mechanistic understanding of the relationship between selectivity and promiscuity commonly observed in the interactions mediated by peptide recognition modules as well as its functional meaning remain elusive. To address these questions in a comprehensive manner, two large populations of artificial and natural peptide ligands of six archetypal PDZ domains from the synaptic proteins PSD95 and SAP97 were generated by target-assisted iterative screening (TAIS) of combinatorial peptide libraries and by synthesis of proteomic fragments, correspondingly. A comparative statistical analysis of affinity-ranked artificial and natural ligands yielded a comprehensive picture of known and novel PDZ ligand specificity determinants, revealing a hitherto unappreciated combination of specificity and adaptive plasticity inherent to PDZ domain recognition. We propose a reconceptualization of the PDZ domain in terms of a complex adaptive system representing a flexible compromise between the rigid order of exquisite specificity and the chaos of unselective promiscuity, which has evolved to mediate two mutually contradictory properties required of such higher order sub-cellular organizations as synapses, cell junctions, and others – organizational structure and organizational plasticity/adaptability. The generalization of this reconceptualization in regard to other protein interaction modules and specific protein associations is consistent with the image of the cell as a complex adaptive macromolecular system as opposed to clockwork

    Order without design

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    Experimental reality in molecular and cell biology, as revealed by advanced research technologies and methods, is manifestly inconsistent with the design perspective on the cell, thus creating an apparent paradox: where do order and reproducibility in living systems come from if not from design

    Similarity classes of 3x3 matrices over a local principal ideal ring

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    In this paper similarity classes of three by three matrices over a local principal ideal commutative ring are analyzed. When the residue field is finite, a generating function for the number of similarity classes for all finite quotients of the ring is computed explicitly.Comment: 14 pages, final version, to appear in Communications in Algebr

    Dynamic redistribution of the electric field of the channel in AlGaN/GaN high electron mobility transistor with nanometer-scale gate length

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    Transport peculiarities and the physical origin of noise properties in AlGaN/GaN-based high electron mobility transistors (HEMTs) with a large ratio of channel length to gate length were investigated. Dependence of deviations of low-frequency noise spectra from the 1/f law on applied gate voltages was studied in an extended range of frequencies. The behavior is explained in terms of a model based on the dynamic redistribution of the electric field along the two-dimensional channel of the HEMT. The results show that the main contribution to the noise originates from the region under the gate and adjacent to the gate channel regions. (C) 2005 American Institute of Physics

    Numerical Simulation of Vortex Crystals and Merging in N-Point Vortex Systems with Circular Boundary

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    In two-dimensional (2D) inviscid incompressible flow, low background vorticity distribution accelerates intense vortices (clumps) to merge each other and to array in the symmetric pattern which is called ``vortex crystals''; they are observed in the experiments on pure electron plasma and the simulations of Euler fluid. Vortex merger is thought to be a result of negative ``temperature'' introduced by L. Onsager. Slight difference in the initial distribution from this leads to ``vortex crystals''. We study these phenomena by examining N-point vortex systems governed by the Hamilton equations of motion. First, we study a three-point vortex system without background distribution. It is known that a N-point vortex system with boundary exhibits chaotic behavior for N\geq 3. In order to investigate the properties of the phase space structure of this three-point vortex system with circular boundary, we examine the Poincar\'e plot of this system. Then we show that topology of the Poincar\'e plot of this system drastically changes when the parameters, which are concerned with the sign of ``temperature'', are varied. Next, we introduce a formula for energy spectrum of a N-point vortex system with circular boundary. Further, carrying out numerical computation, we reproduce a vortex crystal and a vortex merger in a few hundred point vortices system. We confirm that the energy of vortices is transferred from the clumps to the background in the course of vortex crystallization. In the vortex merging process, we numerically calculate the energy spectrum introduced above and confirm that it behaves as k^{-\alpha},(\alpha\approx 2.2-2.8) at the region 10^0<k<10^1 after the merging.Comment: 30 pages, 11 figures. to be published in Journal of Physical Society of Japan Vol.74 No.

    Detection of several daemon populations in Earth-crossing orbits

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    Detection of negative daemons, DArk Electric Matter Objects, viz. Planckian supermassive (~2*10^-5 g) particles, whose population has been detected in March 2000 to populate near-Earth, almost circular, heliocentric orbits (NEACHOs), is being continued. The NEACHO objects hit the Earth with a velocity ~10-15 km/s. The results of these and new experiments (April-June, 2001) are now processed taking into account the scintillation shape depending on the magnitude and sign of the velocity of the daemons crossing our detector. The data accumulated during the time of the experiment and processed in this way reveal also the presence of (1) a high-velocity (~35-50 km/s) daemon population whose objects can be related to a population in the Galactic disk and/or that in strongly elongated, Earth-crossing heliocentric orbits (SEECHOs), as well as (2) a low-velocity (~3-10 km/s) population in geocentric Earth-surface-crossing orbits (GESCOs), whose objects traverse repeatedly the Earth to suffer a decrease in velocity by ~30-40% in a month in the process. An evolutionary relation between all these three (four?) populations is discussed. Assumptions concerning their manifestations in further observations are put forward. An analysis of possible interaction processes of daemons, which may have different velocities and directions of motion, with the detector components [ZnS(Ag) layers, 0.3-mm thick tinned-iron sheets etc.] on the atomic (emission of Auger electrons) and nuclear (nucleon evaporation from a nucleus excited in the capture and, subsequently, the decay of its protons) levels has permitted estimation of some characteristic times. In particular, the decay time of a daemon-containing proton is ~10^-6 s.Comment: 17 pages in PDF format. Ioffe Physical-Technical Institute preprint No.1753 (July 10, 2001). The work was presented at the All-Russian Astronomical Conference, August 6-12, 2001, St.Petersburg, Russi

    Изучение процесса разгерметизации концевой

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    The investigation of the process of de-pressurization in high-pressure hoses under the thermal aging conditions by the evaluation of the de-pressurization pressure in the places of the arrangement of drain holes has been conducted.Установлена взаимосвязь между давлением разгерметизации концевой арматуры рукавов высокого давления в местах расположения на них специально высверленных дренажных отверстий, временем теплового старения рукавов и сроком их эксплуатации
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