VI. SENSITIVE PERIODS     

Charles H. Zeanah  Megan R. Gunnar  Robert B. McCall  Jana M. Kreppner  Nathan A. Fox 《Monographs of the Society for Research in Child Development》2011,76(4):147-162

This chapter reviews sensitive periods in human brain development based on the literature on children raised in institutions. Sensitive experiences occur when experiences are uniquely influential for the development of neural circuitry. Because in humans, we make inferences about sensitive periods from evaluations of complex behaviors, we underestimate the occurrence of sensitive periods at the level of neural circuitry. Although we are most interested in complex behaviors, such as IQ or attachment or externalizing problems, many different sensitive periods at the level of circuits probably underlie these complex behaviors. Results from a number of studies suggest that across most, but not all, domains of development, institutional rearing limited to the first 4–6 months of life is associated with no significant increase risk for long‐term adverse effects relative to noninstitutionalized children. Beyond that, evidence for sensitive periods is less compelling, meaning that “the earlier the better” rule for enhanced caregiving is a reasonable conclusion at the current state of the science.  相似文献   

Study of resonance-cone propagation in truncated hyperbolic metamaterial grids using transmission-line matrix simulations     

Omar F. Siddiqui  George V. Eleftheriades 《Journal of The Franklin Institute》2011,348(7):1285-1297

In this paper, we utilize transmission-line matrix simulations to study the electromagnetic properties of hyperbolic metamaterial grids, which are synthesized by arranging unloaded transmission lines over electrical ground planes, such that the unit cells are rectangular in shape. The hyperbolic grids support Bragg and Hyperbolic resonant modes that have rectangular and hyperbolic dispersion surfaces, respectively. We demonstrate the formation of these resonant modes in the hyperbolic grids and their refraction, and spatial scanning properties via circuit simulations. The simulation results are compared with experimental results of a two-layer anisotropic hyperbolic metamaterial.  相似文献   

Muscle metabolism and performance improvement after two training programmes of sprint running differing in rest interval duration     

Saraslanidis P  Petridou A  Bogdanis GC  Galanis N  Tsalis G  Kellis S  Mougios V 《Journal of sports sciences》2011,29(11):1167-1174

Repeated-sprint training often involves short sprints separated by inadequate recovery intervals. The effects of interval duration on metabolic and performance parameters are unclear. We compared the effects of two training programmes, differing in rest interval duration, on muscle (vastus lateralis) metabolism and sprint performance. Sixteen men trained three times a week for 8 weeks, each training session comprising 2-3 sets of two 80-m sprints. Sprints were separated by 10 s (n = 8) or 1 min (n = 8). Both training programmes improved performance in the 100-, 200-, and 300-m sprints, but the improvement was greater in the 10-s group during the final 100 m of the 200- and 300-m runs. Independent of interval duration, training mitigated the drop of muscle ATP after two 80-m sprints. The drop in phosphocreatine and the increases in glucose-6-phosphate and fructose-6-phosphate after two 80-m sprints were greater in the 10-s group. In conclusion, training with a limited number of repeated short sprints (≤10 s) may be more effective in improving speed maintenance in 200- and 300-m runs when performed with a 1:1 rather than a 1:6 exercise-to-rest ratio. This may be due to a greater activation of glycolysis caused, in part, by the limited resynthesis of phosphocreatine during the very short rest interval.  相似文献   

Glenohumeral joint rotation range of motion in competitive swimmers     

Riemann BL  Witt J  Davies GJ 《Journal of sports sciences》2011,29(11):1191-1199

Much research has examined shoulder range of motion adaptations in overhead-unilateral athletes. Based on the void examining overhead-bilateral athletes, especially competitive swimmers, we examined shoulder external rotation, isolated internal rotation, composite internal rotation, and total arc of motion range of motion of competitive swimmers. The range of motion of registered competitive swimmers (n = 144, age = 12-61 years) was compared by limb (dominant, non-dominant), sex, and age group (youth, high school, college, masters). Significantly (P < 0.05) greater dominant external rotation was observed for both men and women high school and college swimmers, youth women swimmers, and men masters swimmers compared with the non-dominant limb. The isolated internal rotation (glenohumeral rotation), composite internal rotation (glenohumeral rotation plus scapulothoracic protraction), and total arc of motion (external rotation plus composite internal rotation) of the non-dominant limb was significantly greater than that of the dominant limb by sex and age group. Youth and high school swimmers demonstrated significantly greater composite internal rotation than college and masters swimmers. Youth swimmers displayed significantly greater total arc of motion than all other age groups. These data will aid in the interpretation of shoulder range of motion values in competitive swimmers during preseason screenings, injury evaluations and post-rehabilitation programmes, with the results suggesting that differences exist in bilateral external rotation, isolated internal rotation, composite internal rotation, and total arc of motion range of motion.  相似文献   

Understanding Bereavement in a Christian University: A Qualitative Exploration          下载免费PDF全文

Andrea C. Walker  Rachelle Gewecke  Illene N. Cupit  Jeffrey T. Fox 《Journal of College Counseling》2014,17(2):131-149

This phenomenological study, based on ecological systems theory, examined the college student bereavement experience in a Christian university. Undergraduate students (N = 127) from a small Christian university provided answers to open‐ended questions about their experiences regarding college following a death loss. Results indicate that students are generally successful in adapting to bereavement and prefer an environment open to discussing death and asking difficult religious questions. Implications for counselors are provided.  相似文献   

360° Feedback: Ready,Fire, Aim—Issues With Improper Implementation     

George Vukotich 《Performance Improvement》2014,53(1):30-35

This article looks at 360° feedback, as well as mistakes and misuses that are often made in its implementation and use. Too often individuals look for tools to give them facts to support predetermined opinions rather than gathering facts to support individuals in their growth and development process. By identifying these issues and addressing them up front, larger issues that can negatively affect the overall culture of an organization can be avoided.  相似文献   

Domestic abuse prevention education: listening to the views of young people     

Claire L. Fox  Rebecca Hale  David Gadd 《Sex education》2014,14(1):28-41

This paper reports on findings derived as part of a two-year project funded by the European Union's Daphne III scheme, involving collaboration between seven partner organisations across six European countries. The project involved an evaluation, using questionnaires and focus groups, of domestic abuse prevention education programmes delivered in schools in the UK, France and Spain. This paper presents the findings from the UK focus group discussions, conducted with young people aged 10–11 years, and 13–14 years to explore their opinions about the intervention delivered in their school. The focus groups revealed the following challenges for service providers in this area: young people can misunderstand issues related to domestic abuse, especially the role of power and control within relationships; there is a tension between educators giving young people free expression to share their opinions and challenging sexism and other prejudices; and boys can become disengaged with gender-based interventions. These issues point towards three key considerations when implementing a domestic abuse prevention education intervention: programme content (the what); the teaching methods used (the how); and whether teachers or external organisations should deliver the programme (the who).  相似文献   

传世经典     

George Gissing  赵秀明 《世界文化》2006,(9):34-34

……当春天从玫瑰红的云彩中露出她的碧眼,当阳光在我的书桌上闪烁时,我渴望的发疯般地闻一闻那百花绽放的大地的芳香,看一看那山坡上落叶松的葱郁,听一听高地上云雀的歌唱。曾几何时,似乎比童年还要遥远的那个时刻,我满腔热情地拿起了笔。如果那时我的手在颤抖,那也只是因为希  相似文献   

On the application of gunpowder as an instrument of engineering operations,exemplified by its use in blasting marl rocks in the River Severn     

George Edwards 《Journal of The Franklin Institute》1847,43(5):353-359

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The dyslexic copes     

Norman Phillips  George Bright M.D.  Richard Berg  Foster Nowell 《Annals of dyslexia》1974,24(1):170-173

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