Inhibition of the LH Surge by Restraint Stress in Cyclic Rats: Studies on the Role of GABAA and GABAB Receptors

There is evidence that stress can alter the activity in the brain of gamma-aminobutyricacid (GABA), a neurotransmitter that has been implicated in the regulation of LH secretion. In the present study the role of GABA in the restraint stress-induced inhibition of the LH surge was investigated in the intact cyclic rat. Intracerebroventricular (icv) administration of the GABAA receptor agonist muscimol (0.1, 0.5 or 1 μg) 5 min before the presumed onset of the pro-oestrous LH surge (at 0900 h) caused a dose dependent suppression of the surge. A single dose of the GABAB receptor agonist baclofen (1 μg; icv) injected at 0855 h postponed the onset of the LH surge, and repeated injections at 0855 and 1130 h suppressed the surge. These data indicate that GABA-ergic activity in the brain can inhibit the LH surge in the cyclic rat via GABAA and GABAB receptors. Pro-oestrous rats were subjected to 5 hrs of restraint starting at 0855 h. Pretreatment with the GABAA receptor antagonist bicuculine (1 μg; icv) at 0840, 0940 and 1040 h or pretreatment with the GABAB receptor antagonist phaclofen (10 μg; icv) at 0840 h were ineffective in preventing the restraint-induced inhibition of the LH surge. The results suggest that GABAA and GABAB receptors are not involved in the inhibitory effect of restraint stress on the LH surge.     

Effects of Acute Stress or Centrally Injected Interleukin-1beta on Neuropeptide Expression in the Immune System

Acute stress stimulates the expression and release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus, and the pro-opiomelanocortin products beta-endorphin and ACTH from the anterior pituitary. These neuropeptides are also expressed in immune tissues, and it has been proposed that they may modulate immune responses to stress through paracrine mechanisms. We subjected rats to restraint stress or central injection of interleukin (IL)-1beta to determine whether these acute stimuli can alter the expression of neuropeptides in the spleen and thymus. Restraint stress significantly increased the contents of all these neuropeptides in thymic, but not splenic, extracts. A single icv injection of IL-1beta increased contents of CRH, AVP, ACTH and beta-endorphin in the spleens of both sham-operated and adrenalectomised (ADX) rats. IL-1beta increased thymic contents of CRH and ACTH in sham-operated rats but these increases were not observed in ADX rats. These results suggest that the effects of IL-1beta on neuropeptide expression in the spleen are independent of glucocorticoids, whereas IL-1beta stimulation of neuropeptide expression in the thymus is dependent on circulating glucocorticoids. There were significant correlations between increases in CRH, ACTH and beta-endorphin in the spleen, and between CRH and ACTH in the thymus, consistent with the suggestion that IL-1beta-induced increases in ACTH and beta-endorphin may be mediated through CRH. These results provide evidence that stressors can directly influence neuropeptide expression in immune tissues. Thus stress may influence immune functions through paracrine mechanisms involving locally synthesised neuropeptides as well as through activation of the hypothalamo-pituitary-adrenal axis.     

Change in physical self-perceptions across the transition to secondary school: Relationships with perceived teacher-emphasised achievement goals in physical education

ObjectivesThis study aimed to examine the effects of change in perceived teacher achievement goal emphasis in physical education (PE) on physical self-perceptions and self-esteem across the transition to secondary school.Design & methodsA longitudinal design was adopted with three time points, one at the end of primary school and two during the first year of secondary school. Participants (N = 491) were cross-classified by primary (N = 42) and secondary (N = 46) PE class in order to examine the association between perceived class-level teacher-emphasised goals and within-class student goals with self-beliefs.ResultsPersonal approach goals and class perceptions of teacher mastery approach goal promotion were all positively associated with ratings of co-ordination, sport competence, flexibility, and endurance in primary school. More favourable perceptions of coordination, sport competence, strength, flexibility, and endurance during the first year of secondary school were predicted by an increase in performance approach goal emphasis, whereas ratings of sport competence and flexibility were negatively associated with an increase in mastery approach goal emphasis.ConclusionsAlthough not entirely consonant with theoretical predictions, current findings suggest that teacher-emphasised performance approach goals in PE can promote development of several physical self-perceptions in the initial year of secondary school.     

大学二年级学生人际宽恕与报复心理及其与抑郁的关系研究

采用沉思量表、报复动机量表、宽恕倾向量表、宽恕态度量表和流调中心用抑郁量表对236名大二学生进行问卷调查,综合探讨大学生人际宽恕和报复心理及其与抑郁的关系。研究发现:(1)男大学生的报复倾向显著高于女大学生。(2)宽恕倾向与报复倾向及对侵犯的沉思程度显著负相关。沉思程度和抑郁显著正相关。(3)沉思程度和宽恕倾向对抑郁分别具有显著的正向和负向的预测作用。(4)大学生的宽恕倾向和宽恕态度的相互作用以及宽恕倾向和报复倾向之间的交互作用对抑郁均没有显著预测作用。     

A qualitative investigation exploring the motivational climate in early career sports participants: Coach,parent and peer influences on sport motivation

ObjectivesThe objectives of this research were a) to explore the applicability of ‘motivational climate’ research to early career athletes under the age of twelve, b) to re-examine the concept of ‘motivational climate’ in the light of recent scientific developments, and c) to concurrently study the influences of coaches, parents and peers on athletic motivation.Design and MethodUsing a qualitative design, 40 participants (7–11 years of age) from various sports were interviewed in focus groups, using a semi-structured format to investigate the roles played by coaches, parents, and peers in influencing athlete motivation. An inductive content analysis was conducted to determine which behaviours among these social agents influenced key motivational outcomes.FindingsThe analysis indicated that young athletes experience a motivational climate which shows consistencies with existing models of motivation; suggesting this population is worthy of further study. The influences of coaches related most strongly to the manner in which they perform their roles of instruction and assessment, whereas parents' influences were most salient in terms of the way they support the child's participation and learning. Both parents and coaches exerted influences through their leadership styles, affective responses and pre-performance behaviours. Peers influenced participants' motivation through competitive behaviours, collaborative behaviours, evaluative communications and through their social relationships.ConclusionsThis study provides an insight into the motivational climate experienced by young athletes and helps to delineate the different roles of social agents in influencing their motivation at this early stage of development.     

Absolute error revisited: an accuracy indicator in disguise

When target accuracy is defined as the probability that an individual will respond to an accuracy task within a fixed distance around the target, then the composite error measures, E and AE, are shown to be fairly strong indicators of target accuracy in a relative sense. When AE and E are compared, AE is shown to be an even stronger accuracy indicator than E for most reasonable accuracy requirements. This, plus the fact that AE has certain desirable properties in ANOVA procedures, suggests that AE is a good, composite measure of target accuracy and should be analyzed first to determine if target accuracy differences exist. Subsequent analyses of bias and/or variability are then recommended.     

Motivational climate interventions in physical education: A meta-analysis

Objective

The purpose of this study was to synthesize findings from motivational climate interventions employing [Ames, 1992a] and [Ames, 1992b] and [Epstein, 1988] and [Epstein, 1989] TARGET framework within school-based physical education contexts.

Design

The present study employed a quantitative research synthesis design. Meta-analysis uses empirical studies to summarize past research by drawing overall conclusions from separate investigations. This research design highlights important and unsolved issues related to motivational climate interventions within physical education.

Methods

Standard meta-analytic procedures incorporating inclusion and exclusion criteria, literature search, coding procedures, and statistical methods were used to identify and synthesize 22 studies with 24 independent samples. Cohen’s (1988) criteria for effect sizes were used to interpret and evaluate results.

Results

There was an overall small positive treatment effect (g = 0.103) for groups exposed to mastery motivational climates. Outcome analyses identified the most consistent and largest overall treatment effects for behavioral outcomes (g = 0.39–0.49) followed by affective outcomes (g = −0.27 to 0.59) and cognitive outcomes (g = −0.25 to 0.32). Moderator analyses were directed by study heterogeneity and identified several trends in intervention features and study features with the most substantial trend for participant features as elementary students had the largest overall treatment effect (g = 0.41).

Conclusions

Outcome and moderator analyses identified several trends in methodological features, participant features, and study features that should be addressed in future physical education motivational climate interventions.     

Jurors' locus of control and defendants' attractiveness in death penalty sentencing

The authors examined the relationship between jurors' locus of control and defendants' attractiveness in death penalty sentencing. Ninety-eight participants voluntarily served as mock jurors. The authors administered J. B. Rotter's (1966) Internal-External Locus of Control Scale to participants and then randomly assigned them to a group with either an attractive or an unattractive defendant (represented by photographs). Participants read a murder vignette and selected a punishment--either a lifetime jail sentence or the death penalty-for the defendant. Results indicated that neither jurors' locus of control nor defendants' attractiveness influenced sentencing. However, jurors' age and gender significantly influenced sentencing. Men, with the exception of the youngest men, were more likely than women to choose the death penalty. Additionally, young women were more likely than older women to select the death penalty. The authors discuss the implications of these results for the study of jury behavior and bias.     

Information processing bias against emotional facial expressions in social anxiety

The present study examined whether information processing bias against emotional facial expressions is present among individuals with social anxiety. College students with high (high social anxiety group; n  = 26) and low social anxiety (low social anxiety group; n  = 26) performed three different types of working memory tasks: (a) ordering positive and negative facial expressions according to the intensity of emotion; (b) ordering pictures of faces according to age; and (c) ordering geometric shapes according to size. The high social anxiety group performed significantly more poorly than the low social anxiety group on the facial expression task, but not on the other two tasks with the nonemotional stimuli. These results suggest that high social anxiety interferes with processing of emotionally charged facial expressions.