Protection and vulnerability processes relevant for early onset of substance use: a test among African American children.

This research tested predictions from a self-regulation model of factors relevant for early onset of tobacco and alcohol use with a community sample of 889 African American children (mean age = 10.5 years). Criterion variables were peer substance use, willingness to use substances, and resistance efficacy (intention to refuse substance offers). Structural modeling indicated effects of temperament dimensions were mediated through self-control and risk-taking constructs, which were related to school involvement, life events, and perceived vulnerability to harmful effects of substances. Peer use was predicted by life events, poor self-control, and parent-child conflict; willingness was predicted by life events, risk taking, and (inversely) parental support; and resistance efficacy was predicted by perceived vulnerability and (inversely) poor self-control. Findings are discussed with reference to theoretical models of early protection and vulnerability processes.     

Perforant path activation modulates the induction of long-term potentiation of the schaffer collateral--hippocampal CA1 response: theoretical and experimental analyses

In one computational model of hippocampal function, the entorhinal cortical input to CA1 is hypothesized to play a key role in the ability of CA1 to decode CA3 recodings. Here, we develop a modification of this CA1 decoder hypothesis that is applicable to several computational theories of hippocampal function, and then we electrophysiologically investigate one assumption of this new hypothesis. First, using biologically realistic estimates, we calculate that CA3-induced CA1 excitation is too high and that inhibition plausibly plays a role in this CA1 decoder model. Thus motivated, we turn to a physiological demonstration to substantiate the plausibility of the proposed mechanism. Using the rat hippocampal slice, we examine an interlaminar interaction between the distal perforant path input to hippocampal CA1 stratum moleculare and the more proximal Schaffer collateral input to stratum radiatum. Perforant path activation provides sufficient inhibition to block homosynaptic long-term potentiation elicited by a suitably strong stratum radiatum input. For this interlaminar interaction to be most effective, perforant path activation must both precede and follow Schaffer collateral activation. Perforant path-evoked inhibition in CA1 can thus serve as a viable mechanism in the learned decoder theory of hippocampal CA1.     

Differences in the micromechanical properties of dendrites and interdendritic regions in superalloys

Statistical analysis of white-light interferometry (WLI) experiments performed on Ni-based single-crystal superalloys (SX) have revealed a different height distribution between the dendritic cores (DCs) and the interdendritic regions (IRs) of the polished samples. The micromechanical property difference is largely ascribed to the uneven distribution of the alloying elements. In this context, possible reasons for this difference are discussed by comparing with different experiment results obtained by previous researchers, and a proposal forecasting the hardness ratio of IRs/DCs is put forward.     

Resurgence is greater following a return to the training context than remaining in the extinction context

The present study examined whether resurgence of a previously reinforced target response upon removing alternative reinforcement would be greater when (1) returning to the original training context (ABA context changes) versus (2) remaining in the analogue treatment context in which the alternative response was differentially reinforced (ABB context changes). Experiment 1 arranged reinforcement of button pressing with points exchangeable for money in university students. Experiment 2 arranged reinforcement of lever pressing with food for rats. Experiment 3 arranged reinforcement of responses to a touchscreen with small bites of food with children diagnosed with ASD. Overall, resurgence of target responding tended to be greater when returning to the original training context (A) than when remaining in the analogue treatment context (B). These findings suggest context changes with differential reinforcement treatments could exacerbate the recurrence of problem behavior resulting from reductions in treatment integrity through failure to reinforce appropriate behavior.     

Effect of pressure on the mechanical and dynamical stability of NaAlSi

The effects of pressure on the mechanical and dynamical stability of NaAlSi have been fully investigated by first-principles calculations within the generalised gradient approximation (GGA). The obtained results show that the optimised lattice constants, atomic positions and elastic constants at ambient pressure are in good agreement with the available experimental and theoretical data. The lattice constants decrease monotonically with increasing pressure. The elastic constant C₁₁, C₁₂, C₁₃, C₃₃ and C₆₆ increase while C₄₄ decreases with increasing pressure. It is found that NaAlSi is mechanically unstable when the pressure is above 25.97?GPa. The phonon-dispersion curves along several high symmetry lines are obtained. The phonon frequencies at the Z point decrease with increasing pressure and completely soften to zero at 27.52?GPa, further confirming the structural instability of NaAlSi.     

Gender differences in psychological morbidity,burnout, job stress and job satisfaction among Chinese neurologists: a national cross-sectional study

Women are an important part of the medical workforce, yet little is known about gender differences in psychological morbidity, burnout, job stress and job satisfaction among neurologists. This study assessed gender differences in a large national sample of Chinese neurologists. Multivariate analyses were performed to examine associations. A total of 5558 neurologists were included in the analysis. Compared with their male counterparts, female neurologists were generally younger; were less likely to be married or to have children; had higher levels of education; were in practice for a shorter period of time; were less likely to hold senior roles; and had lower incomes. Male and female neurologists worked similar hours and spent a similar number of nights on call. No gender differences were found in psychological morbidity, burnout, and high levels of job stress for female and male, respectively. Women had higher emotional exhaustion scores, while men were more likely to have low levels of job satisfaction. The multivariate analysis showed that factors independently associated with psychological morbidity, burnout, high levels of job stress and low levels of job satisfaction were generally similar for women and men. These findings increase our understanding of gender differences in psychological morbidity, burnout, job stress, and job satisfaction among neurologists. As more women join the medical profession, these differences may be useful in designing medical training and practice.