Synaptic GABA release prevents GABA transporter type-1 reversal during excessive network activity.

GABA transporters control extracellular GABA, which regulates the key aspects of neuronal and network behaviour. A prevailing view is that modest neuronal depolarization results in GABA transporter type-1 (GAT-1) reversal causing non-vesicular GABA release into the extracellular space during intense network activity. This has important implications for GABA uptake-targeting therapies. Here we combined a realistic kinetic model of GAT-1 with experimental measurements of tonic GABAA receptor currents in ex vivo hippocampal slices to examine GAT-1 operation under varying network conditions. Our simulations predict that synaptic GABA release during network activity robustly prevents GAT-1 reversal. We test this in the 0 Mg(2+) model of epileptiform discharges using slices from healthy and chronically epileptic rats and find that epileptiform activity is associated with increased synaptic GABA release and is not accompanied by GAT-1 reversal. We conclude that sustained efflux of GABA through GAT-1 is unlikely to occur during physiological or pathological network activity

Dynamics of streamer discharge development in semiconductors

Space-time dynamics of streamer discharges in semiconductors in view of processes of shock (tunnel and photo-) ionization, radiating spontaneous and stimulated recombination as well as electron-photon interaction in a strong electric field has been modeled. The possibility of formation in these conditions of space-nonuniform dissipative structures, self-oscillatory regular and other modes were shown; their laws and interrelation with dynamics of streamer laser discharge were established. Nonmonotonic dependence of system characteristics on key parameters - excitation rate, life time of nonequilibrium carriers and photons, quantum efficiency of active environment as well as strengthening of structure interaction in conditions of stimulated recombination causing variety of own system dynamics were revealed. Radiating processes provide high speed of structure distribution compared with phase speed of light, and they are the basic generation mechanism of nonequilibrium carriers generation in self-oscillatory mode respective to optimum conditions of streamer occurrence and developmen

Optimization of limiting modes of streamer semiconductor laser

The influence of intensive electric and optical fields produced by streamer discharge in wide-gap semiconductor on their spectroscopic properties has been studied. The given effect is developed at appearance of reversed reconstruction of active environment luminescent characteristics. The methods of sufficient increase in durability and efficiency of streamer laser at limiting modes based on application of semiconductor protecting layers of a definite crystallographic orientation and crystal microrelief with element size of light wave length order. Streamer luminescence in new perspective CaGa2S4:Eu, Ca4Ga2S7:Eu compounds is found and studied

Asymptotic Learning Curve and Renormalizable Condition in Statistical Learning Theory

Bayes statistics and statistical physics have the common mathematical structure, where the log likelihood function corresponds to the random Hamiltonian. Recently, it was discovered that the asymptotic learning curves in Bayes estimation are subject to a universal law, even if the log likelihood function can not be approximated by any quadratic form. However, it is left unknown what mathematical property ensures such a universal law. In this paper, we define a renormalizable condition of the statistical estimation problem, and show that, under such a condition, the asymptotic learning curves are ensured to be subject to the universal law, even if the true distribution is unrealizable and singular for a statistical model. Also we study a nonrenormalizable case, in which the learning curves have the different asymptotic behaviors from the universal law

Summing Over Inequivalent Maps in the String Theory Interpretation of Two Dimensional QCD

Following some recent work by Gross, we consider the partition function for QCD on a two dimensional torus and study its stringiness. We present strong evidence that the free energy corresponds to a sum over branched surfaces with small handles mapped into the target space. The sum is modded out by all diffeomorphisms on the world-sheet. This leaves a sum over disconnected classes of maps. We prove that the free energy gives a consistent result for all smooth maps of the torus into the torus which cover the target space $p$ times, where $p$ is prime, and conjecture that this is true for all coverings. Each class can also contain integrations over the positions of branch points and small handles which act as ``moduli'' on the surface. We show that the free energy is consistent for any number of handles and that the first few leading terms are consistent with contributions from maps with branch points.Comment: 17 pages, 5 eps figures contained in a uuencoded file, UVA-HET-92-1

Fluoride technology of obtaining REM magnetic alloys and master alloys

Rare earth permanent magnets (REPM) based on neodymium-Fe-boron system are the most promising, since they have the highest magnetic and satisfactory mechanical characteristics. The paper covers physical-chemical principles and shows the results of experimental studies of the process of obtaining REM alloys and master alloys using fundamentally new fluoride technology based on ladle calciothermal REM fluorides and Fe reduction

Андрокур в терапии больных раком предстательной железы

Androcur is one of basic drugs for the hormonal treatment of patients with prostate cancer. A great number of randomized studies showing the efficacy of androcur alone and in combination with other hormonal treatments have been completed. When orally or intramuscularly administered, the drug is well tolerated, showing the equal efficacy. Androcur used before treatment with luteinizing hormone-realizing hormone agonists is effective in inhibiting the «flash» syndrome. A combination of the agent with surgical or medical castration enhances the efficiency of therapy and improves the quality of life, by reducing the incidence of adverse reactions, such as hot flashes and hyperhidrosis. Androcur therapy prior to radical prostatectomy decreases the frequency of positive surgical edge while neoadjuvant therapy used before radiotherapy enhances the efficiency of radiation and reduces the number of local recurrences.

Принципи організаціїї інтер'єрів центру підготовки пілотів-операторів безпілотної авіації

This paper studies the development of specialized training interiors. We found the principles of functional and spatial organization of interiors center pilot training operators of unmanned aircraft. All rooms are categorized on the basis of the center functionality.Проведены исследования вопросов развития специализированных учебных интерьеров. Выявлены принципы функционально–пространственной организации интерьеров центра подготовки пилотов–операторов беспилотной авиации. Все помещения центра классифицированы по принципу функциональности.В даній статті проведені дослідження питання розвитку спеціалізованих навчальних інтер’єрів. Виявлено принципи функціонально–просторової організації інтер’єрів центру підготовки пілотів–операторів безпілотної авіації. Всі приміщення центру класифіковані за принципом функціональності