Submicron beam X-ray diffraction of nanoheteroepitaxily grown GaN: Experimental challenges and calibration procedures

Highly relaxed GaN nanodots and submicron ridges have been selectively grown in the NSAG regime using MOVPE on lattice mismatched 6H–SiC and AlN substrates. 2D real space and 3D reciprocal space mapping was performed with a CCD detector using 10.4 keV synchrotron X-ray radiation at the 2-ID-D micro-diffraction beamline at Advanced Photon Source (APS). Calibration procedures have been developed to overcome the unique challenges of analyzing NSAG structures grown on highly mismatched substrates. We studied crystallographic planar bending on the submicron scale and found its correlation with strain relaxation in the NSAG ridges.     

The GABAergic-like system in the marine demosponge Chondrilla nucula

Gamma-amino butyric acid (GABA) is believed to be the principal inhibitory neurotransmitter in the mammalian central nervous system, a function that has been extended to a number of invertebrate systems. The presence of GABA in the marine demosponge Chondrilla nucula was verified using immunofluorescence detection and high-pressure liquid chromatography. A strong GABA-like immunoreactivity (IR) was found associated with choanocytes, exopinacocytes, endopinacocytes lining inhalant, and exhalant canals, as well as in archaeocytes scattered in the mesohyl. The capacity to synthesize GABA from glutamate and to transport it into the vesicles was confirmed by the presence in C. nucula of glutamate decarboxylase (GAD) and vesicular GABA transporters (vGATs), respectively. GAD-like and vGAT-like IR show the same distribution as GABA-like IR. Supporting the similarity between sponge and mammalian proteins, bands with an apparent molecular weight of about 65-67 kDa and 57 kDa were detected using antibodies raised against mammalian GAD and vGAT, respectively. A functional metabotropic GABA(B)-like receptor is also present in C. nucula. Indeed, both GABA(B) R1 and R2 isoforms were detected by immunoblot and immunofluorescence. Also in this case, IR was found in choanocytes, exopinacocytes, and endopinacocytes. The content of GABA in C. nucula amounts to 1225.75 +/- 79 pmol/mg proteins and GABA is released into the medium when sponge cells are depolarized. In conclusion, this study is the first indication of the existence of the GABA biosynthetic enzyme GAD and of the GABA transporter vGAT in sponges, as well as the first demonstration that the neurotransmitter GABA is released extracellularly.     

Anger expression and adaptation to childhood sexual abuse: The role of disclosure.

Previous research on anger and childhood sexual abuse (CSA) is largely cross-sectional and retrospective. In this study, we prospectively examined the consequences of expressing anger among sexually abused women in contexts of either voluntarily disclosing or not disclosing a previous abuse episode (n = 94). All CSA survivors in the study had documented histories of CSA. These participants and a matched, nonabused sample were asked to describe their most distressing experience while being videotaped to allow coding of anger expression. Approximately two thirds of the CSA survivors voluntarily disclosed a previous abuse experience. Participants completed measures of internalizing symptoms and externalizing symptoms at the time of disclosure and again two years later. The expression of anger was associated with better long-term adjustment (decreased internalizing and externalizing symptoms), but only among CSA survivors who had expressed anger while not disclosing an abuse experience. For CSA survivors who disclosed an abuse experience and for nonabused women, anger expression was unrelated to long-term outcome. These findings suggest that the benefits of anger expression for CSA survivors may be context specific. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Effects of diet on casein and fatty acid profiles of milk from goats differing in genotype for αS1-casein synthesis

This study investigated the interactions between nutrition and the genotype at α_S1-CN loci (CSN1S1) in goats, evaluating the impact of fresh forage-based diets and an energy supplement on the casein and fatty acid (FA) profiles of milk from Girgentana goats. Twelve goats were selected for having the same genotype at the α_S2-CN, β-CN, and κ-CN loci and differing in the CSN1S1 genotype: homozygous for strong alleles (AA) or heterozygous for strong and weak alleles (AF). Goats of each genotype were divided into three groups and, according to a 3 × 3 Latin square design, fed ad libitum three diets: sulla fresh forage (SFF), SFF plus 800 g/day of barley (SFB), and mixed hay plus 800 g/day of barley (MHB). The SFB diet led to higher-energy intake and milk yield. The energy-supplemented diets (SFB, MHB) reduced milk fat and urea and increased coagulation time. The fresh forage diets (SFF, SFB) increased dry matter (DM) and crude protein (CP) intake and milk β-CN. Diet had a more pronounced effect than CSN1S1 genotype on milk FA profile, which was healthier from goats fed the SFF diet, due to the higher content of rumenic acid, polyunsaturated, and omega-3 FAs. The AA milk had longer coagulation time and higher curd firmness, higher short- and medium-chain FAs (SMFA), and lower oleic acid than AF milk. Significant diet by genotype interactions indicated the higher milk yield of AA goats than AF goats with the higher-energy SFB diet and the lower synthesis of SMFA in AF than in AA goats with the SFF diet.     

Kinetic electron emission in the interactions of slow ions with MgO surfaces

We report experimental energy distributions and yields of electrons emitted from MgO surfaces under the impact of slow noble gas and sodium singly charged ions at varying incident energies.

At impact energies below 1 keV, electron spectra are nearly independent of ion type and energy. A tail of high-energy electrons is observed to grow at higher impact energies.

The results are explained in terms of promotion of oxygen-2p electrons during binary projectile-oxygen collisions populating continuum and excitonic states. Excitons can significantly contribute to electron emission due to the negative electron affinity of the surface.     

Moderators of the emotion inhibition-health relationship: A review and research agenda.

The preponderance of a growing literature suggests that emotion inhibition is associated with poorer health. However, although inhibition and health are clearly related, the "inhibition hypothesis" has taken on the flavor of a contemporary dogma. Conceptual bases are accepted uncritically, and developments from other domains of psychology are incorporated in a selective, self-supporting, and unenlightening manner. Theories have been tested in homogenous samples, with little attention paid to possible contributions from ethnic diversity, developmental differences, or period effects. This article presents an evolutionary framework within which to consider these phenomena. It critiques the conceptual underpinnings of inhibition- health theories and provides a rationale for the expectation of moderator effects across cultures, individuals, and emotions. Directions for future empirical work are provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Continuing bonds and adjustment at 5 years after the death of a spouse.

Thirty-nine bereaved individuals completed the Continuing Bonds Scale (CBS), assessing various aspects of the ongoing attachment to the deceased, at 60 months postloss in a longitudinal conjugal bereavement study. They also completed symptom measures at 6, 14, 25, and 60 months postloss. Higher CBS scores were associated with a more elevated grief-specific symptom pattern over the 5-year postloss period. Moreover, those who expressed greater helplessness and less blame toward the deceased during a monologue role-play involving their deceased spouse at 6 months postloss had higher CBS scores. Finally, greater satisfaction in the past relationship with the spouse was predictive of higher CBS scores. The results were discussed in relation to existing literature on the adaptiveness of continuing bonds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hemodynamic correlates of atrial natriuretic peptide concentration in unselected patients with heart disease of different etiologies

We investigated the ability of patients with frontal-lobe lesions to benefit from advance information in a simple reaction-time task. The task involved pressing a button in response to the appearance of a peripheral target (visual angle of 11.5 degrees). A cue, presented in the centre of the screen, preceded the target onset by either a short (average 500 ms) or a long (average 3000 ms) interval. In half of the trials, the cue was an arrow indicating the location, in the left or right hemifield, of the upcoming target; in the other half, the cue was an uninformative plus sign. In addition to patients with unilateral excisions of frontal cortex, we tested patients with anterior temporal-lobe excisions and normal controls. The frontal-lobe group was mildly impaired with respect to the temporal-lobe group in using advance spatial cues to speed response to the visual target. While the size of the cueing effect changed across the range of cue-target intervals tested, there was no variation across intervals in the size of the impairment exhibited by the frontal-lobe group. The site and the volume of the lesions were determined on the basis of magnetic resonance image (MRI) scans in 10 of the 17 patients in the frontal group. There was no correlation between lesion volume and benefit score in these patients.     

Arrays of Geiger mode avalanche photodiodes

Following our previous work which has led us to fabricate single pixels of geiger mode avalanche photodiodes (GMAPs), we present in this letter the results regarding the fabrication and characterization of a bidimensional array of GMAPs. Low dark count rates and very good uniformity over the sensor are reported. High quantum efficiency in the visible range has been measured. Measurements indicate that not all the nominal active area is effectively sensitive. We have some preliminary evidence that no crosstalk effects are present in our device. Notwithstanding this, in view of a near future shrinking of all dead regions, an optical trench process has been developed and is illustrated here. Possible future trends are highlighted.