The neuroprotective kappa-opioid CI-977 alters glutamate-induced calcium signaling in vitro

The effect of the neuroprotective kappa opioid agonist CI-977 on glutamate (GLU)-stimulated calcium signaling was studied in individual primary rat cortical neurons. Using laser scanning confocal microscopy and the fluorescent calcium probe fluo-3, both the sustained and biphasic intracellular calcium concentration [Ca2+]i changes induced by GLU (20-40 microM) were altered by CI-977 (25-100 nM), thereby shifting the neuronal population response from unbuffered to buffered patterns of [Ca2+]i flux. This effect was consistent with the previously demonstrated neuroprotective action of CI-977 against glutamate toxicity in vitro. The effect of CI-977 in altering GLU-induced [Ca2+]i signaling was attenuated by naloxone, consistent with a neuroprotective action of CI-977 at opioid receptors, presumably of the kappa subtype.     

Brief, high-frequency stimulation of the corticomedial amygdala induces a delayed and prolonged increase of aggressiveness in male Syrian golden hamsters.

Brief 200-Hz stimulation of the corticomedial amygdala (CMA) increases the aggressiveness of male Syrian golden hamsters for about 30 min; the effect peaks 10–15 min after stimulation. This effect is sensitive to stimulation amplitude and frequency. Stimulation at the parameters that reduce attack latency increases flank marking but does not affect copulation latency or general activity. Immunocytochemical analysis suggests that stimulation effects may be coupled to c-fos expression and that unilateral stimulation has bilateral effects. CMA stimulation effects appear to mimic part of the time course of behaviorally induced attack priming. The temporal persistence of aggression may result from long-term potentiation-like changes within CMA-related neural circuitry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer to adult court: A national study of how juvenile court judges weigh pertinent Kent criteria.

Evaluation of juvenile offenders considered for transfer to adult court entails consideration of three factors: (a) potential risk of dangerousness, (b) level of sophistication-maturity, and (c) treatment amenability. Despite the centrality of these concepts to dispositional decision making, virtually no information or guidelines exist describing how juvenile court judges or mental health professionals should weigh these constructs when making vivid line distinctions with respect to transfer. The authors asked judges (N = 361) from the National Council of Juvenile and Family Court Judges to examine a hypothetical case that varied the level of dangerousness, sophistication-maturity, and treatment amenability. Results showed that dangerousness and sophistication-maturity had a significant impact on transfer, whereas amenability to treatment did not. Policy implications for this important area of law and psychology are threefold: (a) Although individualized assessments may be preferred, key to such evaluations are specific guidelines for weighing Kent criteria; (b) eventually, a national standard should be adopted to outline how to weigh criteria and to reduce disparity across states; and (c) psychologists should continue to refine juvenile assessment technology and ultimately the information they provide courts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A confidence-credibility model of expert witness persuasion: Mediating effects and implications for trial consultation.

Trial consultation is a quickly growing domain of professional practice for psychologists. Preparing expert witnesses to testify is just one prime example of practice options for consultants. A wealth of evidence shows that developing expert confidence and credibility are important goals for witness training. However, research has yet to articulate a list of testimony delivery skills needed to bolster perceptions of credibility and agreement with the expert. The present study advances expert credibility theory and trial consultation practice by empirically validating a confidence-credibility mediation model of expert witness persuasion. It is argued that this model, grounded in credibility and confidence theories, can be integrated with existing methods of witness preparation training. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Thermal Conductivity and Phonon Scattering Processes of ALD Grown PbTe–PbSe Thermoelectric Thin Films

This work studies the thermal conductivity and phonon scattering processes in a series of n‐type lead telluride‐lead selenide (PbTe–PbSe) nanostructured thin films grown by atomic layer deposition (ALD). The ALD growth of the PbTe–PbSe samples in this work results in nonepitaxial films grown directly on native oxide/Si substrates, where the Volmer–Weber mode of growth promotes grains with a preferred columnar orientation. The ALD growth of these lead‐rich PbTe, PbSe, and PbTe–PbSe thin films results in secondary oxide phases, along with an increase microstructural quality with increased film thickness. The compositional variation and resulting point and planar defects in the PbTe–PbSe nanostructures give rise to additional phonon scattering events that reduce the thermal conductivity below that of the corresponding ALD‐grown control PbTe and PbSe films. Temperature‐dependent thermal conductivity measurements show that the phonon scattering in these ALD‐grown PbTe–PbSe nanostructured materials, along with ALD‐grown PbTe and PbSe thin films, are driven by extrinsic defect scattering processes as opposed to phonon–phonon scattering processes intrinsic to the PbTe or PbSe phonon spectra. The implication of this work is that polycrystalline, nanostructured ALD composites of thermoelectric PbTe–PbSe films are effective in reducing the phonon thermal conductivity, and represent a pathway for further improvement of the figure of merit (ZT), enhancing their thermoelectric application potential.     

Knowledge acquisition, accessibility, and use in person perception and stereotyping: Simulation with a recurrent connectionist network.

Connectionist models contrast in many ways with the symbolic models that have traditionally been applied within social psychology. In this article the authors apply an autoassociative connectionist model originally developed by J. L. McClelland and D. E. Rumelhart (1986) to reproduce several well-replicated and theoretically important phenomena related to person perception and stereotyping. These phenomena are exemplar-based inference, group-based stereotyping, the simultaneous application of several stereotypes to generate emergent characteristics, and the effects of recency and frequency of prior exposures on accessibility (the probability of a representation's use). Though many of these phenomena are explained by current theories in social psychology, the simulation contributes to parsimony and theoretical integration by showing that a single, very simple mechanism can generate them all. The model also predicts a new phenomenon—rapid recovery of accessibility after it has declined to zero. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A conceptual and empirical examination of justifications for dichotomization.

Despite many articles reporting the problems of dichotomizing continuous measures, researchers still commonly use this practice. The authors’ purpose in this article was to understand the reasons that people still dichotomize and to determine whether any of these reasons are valid. They contacted 66 researchers who had published articles using dichotomized variables and obtained their justifications for dichotomization. They also contacted 53 authors of articles published in Psychological Methods and asked them to identify any situations in which they believed dichotomized indicators could perform better. Justifications provided by these two groups fell into three broad categories, which the authors explored both logically and with Monte Carlo simulations. Continuous indicators were superior in the majority of circumstances and never performed substantially worse than the dichotomized indicators, but the simulations did reveal specific situations in which dichotomized indicators performed as well as or better than the original continuous indictors. The authors also considered several justifications for dichotomization that did not lend themselves to simulation, but in each case they found compelling arguments to address these situations using techniques other than dichotomization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Staple leg profile influence on pullout strength: a biomechanical study

Bone staples have widespread applicability in orthopaedic surgery. Their use, however, is limited by inconsistent quality of fixation. Prior studies have shown potential for improvement in the reliability of staple fixation through a change in the design of the staple legs. To identify a superior leg cross section profile, pullout strength of 5 different newly designed staple leg cross sections were evaluated in fresh frozen human cadaveric bones before and after toggle loading. The tests were repeated in a synthetic bone model with variable but consistent densities. The curvilinear square profile had the highest pullout strength in both the cadaveric and synthetic bone, followed in descending order by square, circular, and triangular profiles. Controlling for density, the pullout strength of the curvilinear square profile was 8% higher than the square profile and 34% higher than the circular profile. The triangular profiles had the least resistance to pullout force before and after cyclic loading. The curvilinear square may be the best profile for the cross section of the staple leg for maximum pullout strength and may expand the clinical use of staples in bone fixation.