Collective Reputation in Higher Education: An Equilibrium Model

Higher education is valued as a source of skills and knowledge, and also as means to signal à talent of degree holders. The policy reforms intended to make higher education more accessible and strengthen incentives for quality.second of these benefits, unlike the first one, could survive a decline of academic standards. A model of post-secondary education is considered where there are two categories of universities - mass and elite, and their separation is maintained by collective reputation. The model produces an equilibrium in which the university system can still be used for signaling but makes no contribution to the human capital accumulation. The model describes the outcomes of the recent transformation of the Russian university system which was driven primarily by the profit-seeking motives and witnessed precipitous drop of the quality of post-secondary education in both mass and elite segments. That model can also be used to assessmarket signaling, collective reputation, single-crossing condition, university rating

Structure-based mechanism of proton transport through the influenza A M2 protein

Influenza A/M2 is a minimalistic integral membrane protein that mediates proton transport across the viral membrane and is of interest as an antiviral drug target. This protein has been extensively studied by electrophysiologists, biophysicists, structural biologists, and medicinal chemists, but a synthesis and unified extension of the knowledge bases from these fields has not been undertaken. The principal aim of this thesis is to develop a comprehensive, quantitative, structure-based mechanism that accounts for the key functional and biophysical properties of A/M2. To demonstrate the electrophysiological equivalence of the protein’s transmembrane domain (M2TM) and full length A/M2, proteoliposome flux experiments are conducted as a first step. Next, high-resolution crystals of an M2TM variant are obtained; the resulting structure and computational simulations provide a structural basis for the unusually high degree of charge stabilization inside the M2TM helical bundle, suggest a previously unseen mechanism used by Nature to stabilize charge in a membrane, and shed light on the likely pH-dependent structural transitions that the protein undergoes. Fluorescence quenching and EPR spectroscopy experiments confirm that M2 reconstituted in bilayers undergoes pH-driven changes in its conformational equilibrium that are consistent with available structures and governed by previously reported pKa values. Mechanistic models of this process are constructed and successfully fit to functional data. The fitting results show that proton transport and rectification are mediated by conformational transitions between structural ensembles with different proton affinities. Finally, the functional implications of targeted changes to the geometric and electronic properties of the key His 37 sidechain are observed, indicating that the shape of the His 37 imidazole rings is exquisitely tuned to mediate proton transport

Star product formula of theta functions

As a noncommutative generalization of the addition formula of theta functions, we construct a class of theta functions which are closed with respect to the Moyal star product of a fixed noncommutative parameter. These theta functions can be regarded as bases of the space of holomorphic homomorphisms between holomorphic line bundles over noncommutative complex tori.Comment: 12 page

ФОРМУВАННЯ ПРИНЦИПІВ ОРГАНІЗАЦІЇ ДОРОЖНЬОГО РУХУ В СИСТЕМІ „ПЕРЕГІН”

The development of road transport, both economically and socially, is of great importance for humanity. But along with the tremendous benefits andunlimited potential of road transport, there are many problems, particularly with its operation in human settlements, particularly in cities. Theseproblems are related to the oversaturation of the road network of cities with road transport, which leads to a decrease in speed, congestion, increased traveltime. Ensuring the required capacity of the site is the main indicator of creating conditions for the efficient functioning of the transport system of cities.Each section has its own planning features that allow the car to move at an acceptable speed and at the same time not create any situations that could lead to the formation of congestion.It is known that the lower the speed, the greater the time spent. Speed is one of the most important indicators of traffic flow. Any reduction in the speed of traffic flows compared to the permitted leads to economic losses. And if we consider the reduction of speed, taking into account the stop in motion (delay), it leads to much greater economic losses.The development of road transport, both economically and socially, is of great importance for humanity. But along with the tremendous benefits andunlimited potential of road transport, there are many problems, particularly with its operation in human settlements, particularly in cities. Theseproblems are related to the oversaturation of the road network of cities with road transport, which leads to a decrease in speed, congestion, increased traveltime. Ensuring the required capacity of the site is the main indicator of creating conditions for the efficient functioning of the transport system of cities.Each section has its own planning features that allow the car to move at an acceptable speed and at the same time not create any situations that could lead to the formation of congestion.It is known that the lower the speed, the greater the time spent. Speed is one of the most important indicators of traffic flow. Any reduction in the speed of traffic flows compared to the permitted leads to economic losses. And if we consider the reduction of speed, taking into account the stop in motion (delay), it leads to much greater economic losses

The effect of Aharanov-Bohm phase on the magnetic-field dependence of two-pulse echos in glasses at low temperatures

The anomalous response of glasses in the echo amplitude experiment is explained in the presence of a magnetic field. We have considered the low energy excitations in terms of an effective two level system. The effective model is constructed on the flip-flop configuration of two interacting two level systems. The magnetic field affects the tunneling amplitude through the Aharanov-Bohm effect. The effective model has a lower scale of energy in addition to the new distribution of tunneling parameters which depend on the interaction. We are able to explain some features of echo amplitude versus a magnetic field, namely, the dephasing effect at low magnetic fields, dependence on the strength of the electric field, pulse separation effect and the influence of temperature. However this model fails to explain the isotope effects which essentially can be explained by the nuclear quadrupole moment. We will finally discuss the features of our results.Comment: 8 pages, 7 figure

Effect of nuclear quadrupole interactions on the dynamics of two-level systems in glasses

The standard tunneling model describes quite satisfactorily the thermal properties of amorphous solids at temperatures $T<1K$ in terms of an ensemble of two-level systems possessing logarithmically uniform distribution over their tunneling amplitudes and uniform distribution over their asymmetry energies. In particular, this distribution explains the observable logarithmic temperature dependence of the dielectric constant. Yet, experiments have shown that at ultralow temperatures $T<5mK$ such a temperature behavior breaks down and the dielectric constant becomes temperature independent (plateau effect). In this letter we suggest an explanation of this behavior exploiting the effect of the nuclear quadrupole interaction on tunneling. We show that below a temperature corresponding to the characteristic energy of the nuclear quadrupole interaction the effective tunneling amplitude is reduced by a small overlap factor of the nuclear quadrupole ground states in the left and right potential wells of the tunneling system. It is just this reduction that explains the plateau effect . We predict that the application of a sufficiently large magnetic field $B>10T$ should restore the logarithmic dependence because of the suppression of the nuclear quadrupole interaction.Comment: To appear in the Physical Review Letter

Антенна решітка для радіомоніторингу

The radio control system based on the three elements antenna array with noise suppressionfunction is considered. Using of three elements allow to narrow the sector of space reviewing and to simplifythe block diagram. The proposed system provides suppression of the noise by means of simple technicalmeans including situation, when frequencies of the noise and useful signal coincideРассмотрена система радиоконтроля, в основу которой положена трехэлементная антенная решетка с функцией подавления помехи. Использование трех элементов позволяет сузить сектор обзора пространства и упростить блок-схему обработки сигнала. Предложенная система обеспечивает подавление помехи, в том числе совпадающей по частоте с полезным сигналом, при помощи простых технических средствРозглянуто систему радіоконтролю, що засновується на триелементній антенній решітці з функцією придушення завади. Використання трьох елементів дозволяє звузити сектор огляду простору та спростити блок-схему оброблення сигналу. Запропонована система забезпечує придушення завади, у тому числі співпадаючої за частотою з корисним сигналом, за допомогою простих технічних засобі