Sub region-specific modulation of synchronous neuronal burst firing after a kainic acid insult in organotypic hippocampal cultures

Background  

Excitotoxicity occurs in a number of pathogenic states including stroke and epilepsy. The adaptations of neuronal circuits in response to such insults may be expected to play an underlying role in pathogenesis. Synchronous neuronal firing can be induced in isolated hippocampal slices and involves all regions of this structure, thereby providing a measure of circuit activity. The effect of an excitotoxic insult (kainic acid, KA) on Mg²⁺-free-induced synchronized neuronal firing was tested in organotypic hippocampal culture by measuring extracellular field activity in CA1 and CA3.     

Optical characterization of InGaN/AlGaN/GaN diode grown on silicon carbide

Electroluminescence (EL) properties of In_xGa_1−xN/Al_yGa_1−yN/GaN/SiC diode were studied. The spectral range for which EL spectra were recorded is 1–3.5 eV. Room temperature EL was obtained for forward bias (3.18 V, 220 μA) at 446.067 nm (blue luminescence band), 606.98 nm (yellow luminescence band) and 893.84 nm (Infrared luminescence band). The EL temperature dependence shows that, BL band is mostly given by e–h recombination corresponding to indium composition equal to 0.17 ± 0.01 and 0.14 ± 0.02 obtained theoretically and experimentally, respectively. The yellow band is generally weak and absent at low temperature. The IRL band is more consistent with the DAP recombination and could be explained by the thermal activation of Mg states. The luminescence bands shift to lower energies is due probably to the larger potential fluctuations effect.     

R-Deformed Heisenberg Algebra, Quantum Mechanics, and Virasoro Algebra

We review the R-deformed Heisenberg algebra and its Fock space representation.We construct the R-deformed quantum mechanics in N dimensions, and proposea new R-deformed Virasoro algebra.     

Mechanism and kinetics of the reversible transformation lda-hda of amorphous ice under pressure

An ultrasonic investigation of pressure-induced direct and reverse transformations lda-hda between the amorphous phases of low-and high-density ice is performed and the change in the shear modulus is determined. It is found that elastic softening of the amorphous network precedes both transformations, and the behavior of lda phase is similar to that of hexagonal 1h ice before amorphization. At the same time a number of features of the lda-hda transformation are due to the topological disordering of the amorphous phases, and the kinetics of the transformation is different from the standard behavior at a first-order phase transition and also from the compression kinetics of “ classic” glasses of the type a-SiO₂ and a-GeO2. It is shown that the difference in the behavior of the lda and hda amorphous phases under pressure can be attributed to characteristic features of their spectra of low-energy two-level states. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 9, 653–658 (10 May 1999)     

Control of simultaneous effects of the temperature,indium composition and the impact ionization process on the performance of the InN/InxGa1-xN quantum dot solar cells

The impact ionization in semiconductor materials is a process that produces multiple charge carrier pairs from a single excitation. This mechanism constitutes a possible road to increase the efficiency of the p-n and p-i-n solar cells junctions. Our study considers the structure of InN/InGaN quantum dot solar cell in the calculation. In this work, we study the effect of indium concentration and temperature on the coefficient $\theta$ of the material type parameter of the impact ionization process for a p(InGaN)-n(InGaN) and p(InGaN)-i(QDs-InN)-n(InGaN) solar cell. Next, we investigate the effect of perturbation such as temperature and indium composition on conventional solar cell’s (p(InGaN)-n(InGaN)) and solar cells of the third generation with quantum dot intermediate band IBSC (p(InGaN-i(QD-InN)-n(InGaN)) by analyzing their behaviour in terms of efficiency of energy conversion at the presence of the impact ionization process. Our numerical results show that the efficiency is strongly influenced by all of these parameters. It is also demonstrated that $\theta$ decreased with the increase of indium concentration and temperature which contributes to an overall improvement of the conversion efficiency.     

AN APPLICATION OF MULTI‐CRITERIA DECISION MAKING INCORPORATING STOCHASTIC PRODUCTION FRONTIERS: A CASE STUDY OF ORGANIC COFFEE PRODUCTION IN KONA,HAWAII

Abstract In this paper, we develop a land use allocation model to search for the optimal ratio of organic (nonchemical) and conventional (chemical‐use) farming acreage. The idea is to incorporate stochastic production frontiers (SPFs) to a multi‐criteria decision making (MCDM) model as technological constraints. The objectives of this model are to maximize net returns, minimize chemical inputs, and optimize organic inputs given environmental and ecological concerns. The compromise solutions suggest the desirable ratio of organic and conventional farming acreage and targetable operations for each farming system to improve regional welfare. This method was applied to the Kona coffee belt, Hawaii, and the analysis determined the optimal proportion of organic and conventional Kona coffee farming fields as 0.265 to 0.735 in terms of optimizing community benefits or regional welfare.     

Existence of Renormalized Solutions for Nonlinear Parabolic Equations

We give an existence result of a renormalized solution for a class of nonlin- ear parabolic equations b（x,u）/ t-div （a（x,t,u, u））＋g（x,t,u,u ）＋H（x,t, u）=f,in QT, where the right side belongs to LP＇ （0,T;W-1,p＇（Ω）） and where b（x,u） is unbounded function of u and where - div （ a （ x, t, u, u） ） is a Leray-Lions type operator with growth ｜u ｜p- 1 in V u. The critical growth condition on g is with respect to u and no growth condition with re sp ect to u, while the function H （x, t, u） grows as｜ u ｜p - 1.     

Oxidation of Methyl Propanoate by the OH Radical

Russian Journal of Physical Chemistry A - Atmospheric oxidation of methyl propanoate (MP) by the OH radical has been performed using density functional theory (BMK, BBIK) and ab initio (MP2,...