Epilepsy genetics: An abundance of riches for biologists

AbstractTwenty-five genes have been identified in which mutations cause epileptic seizures in mice. The gene for a Na+/H+ exchanger has recently been found to underlie the spontaneous mutant slow wave epilepsy. Studies of such mutants should help elucidate the mechanisms that control neuronal excitability

Genetic variability, character association and path analysis in ashwagandha [Withania somnifera (L.) Dunal] under rainfed conditions

Twenty six diverse genotypes of ashwagandha [Withania somnifera (L.) Dunal]were evaluated for fourteen quantitative traits under rainfed conditions. Both phenotypicand genotypic coefficients of variation were higher for important traits like number ofberries/plant, fresh weight of berries/plant, biomass yield at maturity and ratio of freshabove ground biomass: fresh root biomass. High heritability in conjunction with highgenetic advance were observed for number of berries/plant, fresh weight of berries/plant,seed yield/plant, fresh root yield/plant, biomass yield at maturity and ratio of fresh aboveground biomass : fresh root biomass which indicated predominant role of additive geneaction for the expression of these characters. Fresh root yield/ plant was found to bepositively and significantly correlated with number of berries/plant, fresh weight ofberries/plant, seed yield/plant and root diameter. Path analysis revealed that totalalkaloid content showed the highest positive direct effect on fresh root yield/plantfollowed by biomass yield at maturity, seed yield/plant, root diameter and number ofberries/plant which suggested that selection for these traits would be quite effective toimprove fresh root yield in ashwagandha

Covalent bonding and the nature of band gaps in some half-Heusler compounds

Half-Heusler compounds \textit{XYZ}, also called semi-Heusler compounds, crystallize in the MgAgAs structure, in the space group $F\bar43m$. We report a systematic examination of band gaps and the nature (covalent or ionic) of bonding in semiconducting 8- and 18- electron half-Heusler compounds through first-principles density functional calculations. We find the most appropriate description of these compounds from the viewpoint of electronic structures is one of a \textit{YZ} zinc blende lattice stuffed by the \textit{X} ion. Simple valence rules are obeyed for bonding in the 8-electron compound. For example, LiMgN can be written Li$^+$ + (MgN)$^-$, and (MgN)$^-$, which is isoelectronic with (SiSi), forms a zinc blende lattice. The 18-electron compounds can similarly be considered as obeying valence rules. A semiconductor such as TiCoSb can be written Ti$^{4+}$ + (CoSb)$^{4-}$; the latter unit is isoelectronic and isostructural with zinc-blende GaSb. For both the 8- and 18-electron compounds, when \textit{X} is fixed as some electropositive cation, the computed band gap varies approximately as the difference in Pauling electronegativities of \textit{Y} and \textit{Z}. What is particularly exciting is that this simple idea of a covalently bonded \textit{YZ} lattice can also be extended to the very important \textit{magnetic} half-Heusler phases; we describe these as valence compounds \textit{ie.} possessing a band gap at the Fermi energy albeit only in one spin direction. The \textit{local} moment in these magnetic compounds resides on the \textit{X} site.Comment: 18 pages and 14 figures (many in color

ΔI=4\Delta I=4 and ΔI=8\Delta I=8 bifurcations in rotational bands of diatomic molecules

It is shown that the recently observed $\Delta I=4$ bifurcation seen in superdeformed nuclear bands is also occurring in rotational bands of diatomic molecules. In addition, signs of a $\Delta I=8$ bifurcation, of the same order of magnitude as the $\Delta I=4$ one, are observed both in superdeformed nuclear bands and rotational bands of diatomic molecules.Comment: LaTex twice, 10 pages and 5 PS figures provided upon demand by the Author

Completely splittable representations of affine Hecke-Clifford algebras

We classify and construct irreducible completely splittable representations of affine and finite Hecke-Clifford algebras over an algebraically closed field of characteristic not equal to 2.Comment: 39 pages, v2, added a new reference with comments in section 4.4, added two examples (Example 5.4 and Example 5.11) in section 5, mild corrections of some typos, to appear in J. Algebraic Combinatoric

The Anodic Dissolution Of ZnS Electrodes In Sulfuric Acid Solutions

The anodic dissolution of reagent grade ZnS and ZnS concentrate has been studied. The majority of the research was conducted in H2SO4 although a limited number of tests were made in HCl and KOH. Polarization studies showed that both Zn2+ and S were products in the acidic solutions. ZnS passivated in KOH solutions. The electrodes were fabricated by hand pressing mixtures of ZnS + pitch (5-15%) and sintering at 800°C in a N2 atmosphere. The open circuit potentials were considered to be mixed potentials resulting from the anodic dissolution of ZnS and cathodic reduction of S or O2. Current efficiencies and Zn2+ / S ratios were determined at 0.5 and 0.85 V vs. SHE. The results indicated the occurrence of both electrochemical and chemical dissolution steps as well as the further oxidation of H2S, namely, ZnS(s)=Zn2+(aq)+S(s)+2eZnS(s)=2H+(aq)=Zn2+(aq)+H2S(aq)H2S(aq)+4 H2O(I)=HSO4(aq)+9H+(aq)+8e The overall dissolution appears to be mass transfer-limited, probably either by the diffusion of Zn2+ from the reaction interface, through the reacted layer to the bulk solution, or the dissolution of precipitated Zn(OH)2 in the reacted layer by the diffusion of H+ into the layer. The concentrate anodes polarized more drastically than the reagent grade ZnS anodes, possibly due to the presence of PbS impurity which would form PbSO4 in the anode pores. © 1982

Isolation of Fungi from Lake Vostok Accretion Ice

Here we report the characterization of fungi from 10 accretion ice sections (3300-5100 y old) as well as two deep glacial ice sections that are close to the bottom of the glacier (1 000 000-2 000 000 y old) from the Vostok, Antarctica, 5G ice core. Fungi were characterized by fluorescence microscopy culturing and sequence analyses of ribosomal DNA internal transcribed spacers. A total of 270 fungal colonies were cultured from the accretion ice of subglacial Lake Vostok and an additional 14 from the glacial ice immediately above the accretion ice. Mean concentrations were 0-4.42 cells mL-1 ice meltwater of which 0-100% exhibited viability (as determined by fluorescence microscopy). Thirty-one unique fungal ribosomal DNA sequences (28 from accretion ice and three from glacial ice) were determined and compared to recent taxa. The results, plus tests for growth at low temperatures, indicated that Lake Vostok contains a mixture of heterotrophic psychrotolerant fungal species. This indicates that the lake is not sterile but contains a unique ecosystem

Implications of area scaling of quantum fluctuations

Quantum fluctuations of a certain class of bulk operators defined in spatial sub-volumes of Minkowski space-time, have an unexpected area scaling property. We wish to present evidence that such area scaling may be ascribed to a boundary theory. We first highlight the implications of area scaling with two examples in which the boundary area of the spatial regions is not monotonous with their volume. Next, we prove that the covariance of two operators that are restricted to two different regions in Minkowski space scales linearly with their mutual boundary area. Finally, we present an example which demonstrates why this implies an underlying boundary theory.Comment: 12 pages, 5 figure