Diffusion kinetics for divacancies in the bcc lattice

In this letter we employ high-precision Monte Carlo simulations to investigate tracer diffusion kinetics for diffusion via divacancies in the bcc lattice. We utilize the mechanisms originally identified by Mehrer in which the divacancy can move by nearest-neighbour jumps with stable first-nearest-neighbour, second-nearest-neighbour and fourth-nearest-neighbour configurations of the divacancy. The tracer correlation factor and the 'impurity-form' correlation factor were found to be some 4-6% lower than those found by the matrix method. The tracer diffusion data and isotope effect for sodium were revisited in terms of monovacancy and divacancy contributions. The main change is a revision upwards from 0.55 to 0.61 of the j K kinetic factor for divacancies.     

Clamped Corticosterone (B) Reveals the Effect of Endogenous B on Both Facilitated Responsivity to Acute Restraint and Metabolic Responses to Chronic Stress

To determine the effects of both corticosterone (B) and chronic stressors on acute ACTH responses to restraint, young male rats were exposed to streptozotocin-induced diabetes, cold (5-7 degreesC) or intracerebroventricular (icv) neuropeptide Y (NPY) for 5 d and then exposed to restraint within 2 h after lights on. Two groups of rats were studied: intact and adrenalectomized replaced with B pellets that maintained plasma B in the normal mean 24-h range of intact rats. In addition to ACTH and B responses to restraint on d 5, body weight, food intake, fat depots, glucose and other hormones were measured to determine the role of stress-induced elevations in B on energy balance. ACTH responses to restraint were normal in intact rats subjected to diabetes or cold. By contrast, there was no ACTH or B response to restraint in NPY-infused intact rats. All 3 groups of chronically stimulated adrenalectomized rats with clamped B had facilitated ACTH responses to restraint compared to their treatment controls. Overall food intake increased in all groups of stressed rats; however, augmented intake occurred only during the light in intact rats and equally in the light and dark in B-clamped rats. White adipose depot weights were decreased by both diabetes and cold and increased by NPY in intact rats; the decreases with cold and increases with NPY were both blunted and changes in fat stores were not significant in adrenalectomized, B-clamped rats. We conclude that: 1. diabetes- and cold-induced facilitation of restraint-induced afferent input to hypothalamic control of the hypothalamo-pituitary-adrenal (HPA) axis is opposed in intact rats by the elevated feedback signal of B secretion; 2. NPY does not induce facilitation of afferent stress pathways; 3. chronic stimulation of the HPA axis induces acute hyperresponsiveness of hypothalamic neurons to restraint provided that the afferent input of this acute stimulus is not prevented by B feedback; 4. stimulus-induced elevations in B secretion result in day-time feeding; 5. insensitivity of both caloric efficiency and white fat stores to chronic stress in adrenalectomized, B-clamped rats results from loss of normally variable B levels.     

Repetition effects: a methodological issue in motor short-term memory

A source of possible error in the design of many motor short-term memory studies- the effect of repeated testing of the same criterion positions- was evaluated together with a secondary factor, motivation. Using an arm-positioning task, three groups of five subjects, representing different motivational levels, were tested repeatedly on the same three test positions. Constant and variable error measures indicated significant effects of the repetition factor. Subjects became more accurate with repeated testing of the same positions as reflected by a positive shift in constant error in the direction of the criterion. There was an initial decrease and subjects' motivational level. The apparent assumption in prior studies, that presentations of intervening test items obviates a repetition effect, was clearly refuted. Thus, in many motor short-term memory studies, treatment effects have been inextricably mixed with the effects of repetition.     

Sad and happy emotion discrimination in music by children with cochlear implants

Children using cochlear implants (CIs) develop speech perception but have difficulty perceiving complex acoustic signals. Mode and tempo are the two components used to recognize emotion in music. Based on CI limitations, we hypothesized children using CIs would have impaired perception of mode cues relative to their normal hearing peers and would rely more heavily on tempo cues to distinguish happy from sad music. Study participants were children with 13 right CIs and 3 left CIs (M = 12.7, SD = 2.6 years) and 16 normal hearing peers. Participants judged 96 brief piano excerpts from the classical genre as happy or sad in a forced-choice task. Music was randomly presented with alterations of transposed mode, tempo, or both. When music was presented in original form, children using CIs discriminated between happy and sad music with accuracy well above chance levels (87.5%) but significantly below those with normal hearing (98%). The CI group primarily used tempo cues, whereas normal hearing children relied more on mode cues. Transposing both mode and tempo cues in the same musical excerpt obliterated cues to emotion for both groups. Children using CIs showed significantly slower response times across all conditions. Children using CIs use tempo cues to discriminate happy versus sad music reflecting a very different hearing strategy than their normal hearing peers. Slower reaction times by children using CIs indicate that they found the task more difficult and support the possibility that they require different strategies to process emotion in music than normal.     

Health behaviour and attitudes to publicity campaigns for health promotion

Abstract

A sample of 403 members of the public responded to a postal questionnaire concerning their own health behaviour and their attitudes towards health publicity. A principal components analysis of these attitudes revealed three factors, the first of which reflected a tendency to deny the “relevance” of health campaigns. This tendency was higher among those who smoked, took less exercise and had less healthy diets. It is inferred that the direct effects of such campaigns may be impeded by the fact that they appeal most to those people whose own behaviour (from the point of view of health) is in least need of change.     

阅读预期对快速阅读理解的影响的实验研究

探讨阅读预期对快速阅读的理解水平与进程的影响。实验１探讨阅读预期对快速阅读理解水平的影响。阅读文章前分别给予被试正确、中性与误导的标题提示,结果表明,不同类型的标题提示对快速阅读的理解成绩有显著的影响,而对正常速度阅读的理解成绩影响效果不显著。实验２探讨阅读预期对快速阅读过程的词句加工程度的影响。结果表明,对优生来说,正确标题提示组发现文章中锗字的成绩显著低于误导标题提示组,差生的不同标题提示组发现错字的成绩差异不显著。两个实验的结果初步表明,快速阅读文章过程会更多地利用概念推动,较少地需要材料信息。     

Mental context reinstatement or drawing: Which better enhances children's recall of witnessed events and protects against suggestive questions?

The aim of this experiment was to examine the effectiveness of two techniques in enhancing children's recall of an event that they experienced approximately a week earlier. Younger (5–6 years) and older (8–9 years) children were interviewed about a magic show event in one of three conditions. Before recalling the event, some children were instructed to mentally reinstate the context of the event (MCR group), others were asked to draw the context of the event (DCR group), and others received no reinstatement instructions (NCR). Results showed that these instructions had no impact on children's free recall or responses to open‐ended prompts. However, reinstatement instructions impacted children's responses to suggestive questions: those in the DCR group gave more accurate responses than those in the NCR group. These findings provide preliminary support for the use of drawing as a potentially protective exercise that lessens the impact of biased questions with child witnesses.     

Mental Disorders,Comorbidity, and Pre‐enlistment Suicidal Behavior Among New Soldiers in the U.S. Army: Results from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS)

We examined the associations between mental disorders and suicidal behavior (ideation, plans, and attempts) among new soldiers using data from the New Soldier Study (NSS) component of the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS; N = 38,507). Most new soldiers with a pre‐enlistment history of suicide attempt reported a prior mental disorder (59.0%). Each disorder examined was associated with increased odds of suicidal behavior (ORs = 2.6–8.6). Only PTSD and disorders characterized by irritability and impulsive/aggressive behavior (i.e., bipolar disorder, conduct disorder, oppositional defiant disorder, and attention‐deficit/hyperactivity disorder) predicted unplanned attempts among ideators. Mental disorders are important predictors of pre‐enlistment suicidal behavior among new soldiers and should figure prominently in suicide screening and prevention efforts.