Sexual orientation-related differences in prepulse inhibition of the human startle response.

Prepulse inhibition (PPI) refers to a reduction in the startle response to a strong sensory stimulus when this stimulus is preceded by a weaker stimulus--the prepulse. PPI reflects a nonlearned sensorimotor gating mechanism and also shows a robust gender difference, with women exhibiting lower PPI than men. The present study examined the eyeblink startle responses to acoustic stimuli of 59 healthy heterosexual and homosexual men and women. Homosexual women showed significantly masculinized PPI compared with heterosexual women, whereas no difference was observed in PPI between homosexual and heterosexual men. These data provide the first evidence for within-gender differences in basic sensorimotor gating mechanisms and implicate the known neural substrates of PPI in human sexual orientation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis and activation of Pt nanoparticles with controlled size for fuel cell electrocatalysts

Well-dispersed Pt nanoparticles with controlled size and narrow size distribution were prepared by polyalcohol reduction of platinum acetylacetonate, using oleylamine as a capping agent. The particle size was varied from 3.5 nm to 11.5 nm by decreasing the amount of oleylamine added in the synthesis. Size selection of the as-prepared particles by solvent fractionation yielded nearly monodispersed Pt particles. The as-prepared particles were loaded on a carbon support by physical deposition, but showed no electrocatalytic activity due to the oleylamine bound to the particle surface. The particles were activated for electrocatalysis after heating the particles in air at 185 °C for 5 h, conditions that gave no particle-sintering and no oxidation. Cyclic voltammetry showed that the particles after the heat treatment in air were electrocatalytically active for methanol oxidation. The smaller 3.5 nm and 4.0 nm Pt particles had a higher intrinsic activity for methanol oxidation, but a lower tolerance to CO poisoning, compared with 6.0 nm, 9.5 nm and 11.5 nm particles. CO-stripping results suggest that CO is more easily oxidized on larger Pt particles.     

Investigations of surface characterization of silicone rubber due to tracking phenomena under a.c. and d.c. voltages

In the present work, tracking phenomena has been studied with silicone rubber material under the a.c. and d.c. voltages following IEC-587 standards. The surface condition of the tracked zone was analysed using wide angle X-ray diffraction (WAXD) and thermogravimetric differential thermal analysis (TG-DTA) studies. The tracking time was different for a.c. and d.c. voltages.     

Binders for jute-reinforced unsaturated polyester resin

Reinforcement of polyester resin with jute cloth under constant load is studied, The pretreatment of jute cloth with tetrahydrofuran and the effect of binding properties of poly(vinyl acetate) and acrylic acid and their effect on the impact, tensile, and water absorptions of jute cloth polyester composites are reported and their chemical reactions are discussed.     

A Novel UWB Pulse Shape Modulation System

In this paper novel modified Hermite polynomial functions for use in impulse radio (ultra-wideband) communications are proposed. With these functions pulse shapes which are orthogonal and have nearly constant pulse width regardless of the pulse order are generated. These properties hold under the effects of differentiation. An M-ary communication system is constructed using these pulse shapes. A Matlab model for generating the pulses is designed and the effect of timing jitter on the performance of the system is investigated by computer simulation.     

A note on the Consecutive Ones Submatrix problem

A binary matrix has the Consecutive Ones Property (C1P) for columns if there exists a permutation of its rows that leaves the 1's consecutive in every column. The problem of Consecutive Ones Property for a matrix is a special variant of Consecutive Ones Submatrix problem in which a positive integer K is given and we want to know if there exists a submatrix B of A consisting of K columns of A with C1P property. This paper presents an error in the proof of NP-completeness for this problem in the reference cited in text by Garey and Johnson [Computers and Intractability, A Guide to the Theory of NP-Completeness, 1979].     

Comments on “Equivalence of characterizations of fixed models”

In this note we present a proof to the conjecture given in the above paper, and therefore establish the equivalence of characterizations of fixed modes for the general case.     

Bryostatin 1 induces ubiquitin COOH-terminal hydrolase in acute lymphoblastic leukemia cells

It has been previously reported that Bryostatin 1 (Bryo1) induces differentiation of the human acute lymphoblastic leukemia (ALL) cell line, Reh, to a monocytoid B-cell stage. In this study we demonstrate that a novel protein, ubiquitin COOH-terminal hydrolase (UCH-L1), is associated with this differentiation. Reh cells were treated with 200 nmol/l of Bryo1 for 72 h and analyzed for changes in morphology, surface immunophenotype, acid phosphatase and terminal deoxynucleotidyl transferase. Protein patterns of the parent and differentiated cells, by two-dimensional polyacrylamide gel electrophoresis (2D PAGE), were studied. Bryo1-treated cells expressed morphologic, phenotypic and enzymatic features of the monocytoid B-cell stage. The UCH-L1 enzyme (MW-pl 34-5.3) was detected by 2 D PAGE in the differentiated, but not in parent cells. The presence of UCH-L1 in the Bryo1-treated cells was further confirmed by immunoblotting of 2 D PAGE using UCH-L1 polyclonal antibody. Ubiquitin expression was studied in parent and Bryo1-treated cells and was compared with 12-O-tetradecanoylphorbol-13-acetate (TPA)-treated cells. Both agents, TPA and Bryo1, increased the level of ubiquitin expression as detected by flow cytometry. Sodium borohydride, an inhibitor of UCH-L1, inhibited the Bryo1-induced differentiating effect on Reh cells. To date, the mechanism by which Bryo1, exerts its B-cell differentiating effect is not fully understood. This study shows that UCH-L1 expression may play a major role in Bryo1-induced differentiation in pre-B-ALL.     

Progress and prospects of group-III nitride semiconductors

We review recent progress in the group-III nitride and related materials, and electronic and optical devices based on them. Blue and UV (e.g. ultra violet) emitters and detectors, and high temperature/high power electronics which has long been coveted are beginning to be realized either in the laboratory or in the commercial arena, due in part to the breathtaking progress made in the last few years in the art and science of GaN, InN, AlN and their salloys. With brief references to the historical aspect of the relevant developments, this review concerns itself primarily with the current status of wide bandgap gallium nitride and related semiconductors from both the materials and devices points of view. Following a discussion of the structural properties of these materials, their electrical and optical properties are described in detail. The available data on metal contacts, the properties of which are indeed very conducive for the devices mentioned, from the points of view of ohmic contacts and Schottky barriers, are elaborated on. Recent progress on processing issues such as etching are reviewed. The review then embarks on an indash;depth discussion and analysis of field effect transistors, bipolar transistors, light emitting diodes, laser and photo detectors.