Stability and variability may respond differently to changes in walking speed

In gait research it has often been assumed that variability and stability are negatively correlated, where increases in variability are assumed to equate with increases in instability. The purpose of this paper is to illustrate that variability does not always equate with stability. To proof this point, a method was developed to directly assess stability and variability during the application of a visual perturbation at different walking speeds. Walking variability was measured by using the average standard deviation of the knee joint angle across the gait cycle. Walking stability was measured by the recovery time of the knee joint angle trajectory from the distortion induced by a visual perturbation that was delivered at the beginning of the stance phase. Five participants were required to walk at six different velocities on a treadmill (0.67, 0.80, 0.94, 1.07, 1.21, and 1.34 m/s). The coefficients of intraclass correlations for the experiment were 83% and 80% for the calculated stability and variability, respectively. The calculated stabilities were not sensitive to changes in walking speed (p>0.98). The calculated variability however decreased with increases in walking speed (p=0.004). No significant correlation between variability and stability was observed (r=-0.002). We suggest that gait stability is independent of variability during locomotion and should thus be measured independently.     

青少年的人格特征与互联网信息服务使用的关系

互联网上的信息服务为青少年的个性化学习提供了可能,如何使青少年健康地进行网上冲浪,使他们在冲浪的过程中增强自律意识,就需要我们深入地了解互联网信息服务在哪些方面能够满足青少年的需要。该研究通过对339名中学生进行问卷调查,对青少年的人格特征、社会支持与互联网信息服务之间的关系进行了探讨,结果表明:(1)开放性、客观社会支持和对社会支持的利用对互联网信息服务的使用偏好有直接而显著的影响。(2)宜人性和外向性通过社会支持的三个方面间接地对互联网信息服务的使用偏好产生影响。(3)客观社会支持会影响主观社会支持,主观社会支持对社会支持的利用水平也有影响。     

非英语专业大学生短文写作元认知发展的一般特点

对1043名大学生(有效被试1012人)进行英文写作元认知、自我效能、成就目标、价值、内控性的测量,旨在了解非英语专业大学生英文写作元认知各维度的一般性发展特点。结果发现:语言策略、作文标准、准备性和计划性上存在年级差异;对作为作者的自己的优点的了解、对作为作者的自己的缺点的了解、语言策略知识、元认知体验、计划性、准备性、调节性上存在性别差异;在英文写作自我效能、价值、成就目标、内控性高分组与低分组间元认知水平差异达到显著性,且高分组具有较高的英文写作元认知水平。     

试论管仲人才思想中的民本因素--以《管子》为中心

民本思想是齐文化的重要组成部分,也是管仲施政思想的基石,其言论．行动中都展示着民本思想的精华。而体现管仲思想的《管子》一书,对人才思想有较系统的论述。本文试以管仲为例,以《管子》一书为中心,来探析其人才思想中的民本因素,即“任其所长,不任其所短”的人才原则,包括其产生原因、表现方式、对后世所带来的社会影响等。     

Solving combinatorial problems: The 15-puzzle

We present a series of experiments in which human subjects were tested with a well-known combinatorial problem called the 15-puzzle and in different-sized variants of this puzzle. Subjects can solve these puzzles reliably by systematically building a solution path, without performing much search and without using distances among the states of the problem. The computational complexity of the underlying mental mechanisms is very low. We formulated a computational model of the underlying cognitive processes on the basis of our results. This model applied a pyramid algorithm to individual stages of each problem. The model's performance proved to be quite similar to the subjects' performance.     

Gay adolescents and suicide: understanding the association

Suicide among gay adolescents is a major public health concern, but it is still under-emphasized within mainstream healthcare. This article brings together information garnered from past studies, articles, and experiences to create a more in-depth understanding of why gay adolescents are at a higher risk for suicide. By creating a better understanding, this article attempts to push forward the significance of this issue and encourages physicians to take a more active role in suicide prevention. The article initially explores why issues involving homosexuality are seldom discussed and provides evidence for an increased risk in suicide among gay adolescents. By addressing major psychosocial issues faced by gay adolescents, it spends the majority of time facilitating an understanding of the increased risk. In this article "gay" refers to homosexual males and females, and bisexuals unless otherwise indicated.     

动觉监督早期介入对动作技能形成的影响

通过人工动作技能项目和典型职业操作技能项目的训练活动,研究了动觉监督早期介入对动作技能形成的影响,结果表明早期进行动觉监督训练可以更为充分、有效地发挥动觉监督的作用,提高动作技能形成的成绩和效率。据此讨论了“视觉为主转化为动觉为主”监督机制观点的局限性,认为自觉的职业操作技能训练活动无须遵循这一结论;提出了含有动觉训练的职业操作技能训练模式。     

Biocultural orchestration of developmental plasticity across levels: the interplay of biology and culture in shaping the mind and behavior across the life span

The author reviews reemerging coconstructive conceptions of development and recent empirical findings of developmental plasticity at different levels spanning several fields of developmental and life sciences. A cross-level dynamic biocultural coconstructive framework is endorsed to understand cognitive and behavioral development across the life span. This framework integrates main conceptions of earlier views into a unifying frame, viewing the dynamics of life span development as occurring simultaneously within different time scales (i.e., moment-to-moment microgenesis, life span ontogeny, and human phylogeny) and encompassing multiple levels (i.e., neurobiological, cognitive, behavioral, and sociocultural). Viewed through this metatheoretical framework, new insights of potential interfaces for reciprocal cultural and experiential influences to be integrated with behavioral genetics and cognitive neuroscience research can be more easily prescribed.     

Synaptogenesis and heritable aspects of executive attention

In humans, changes in brain structure and function can be measured non-invasively during postnatal development. In animals, advanced optical imaging measures can track the formation of synapses during learning and behavior. With the recent progress in these technologies, it is appropriate to begin to assess how the physiological processes of synapse, circuit, and neural network formation relate to the process of cognitive development. Of particular interest is the development of executive function, which develops more gradually in humans. One approach that has shown promise is molecular genetics. The completion of the human genome project and the human genome diversity project make it straightforward to ask whether variation in a particular gene correlates with variation in behavior, brain structure, brain activity, or all of the above. Strategies that unify the wealth of biochemical knowledge pertaining to synapse formation with the functional measures of brain structure and activity may lead to new insights in developmental cognitive psychology.