Energetic Cost and Stability during Human Walking at the Preferred Stride Frequency

The possibility that preferred modes of locomotion emerge from dynamical and optimality constraints and the energetic and dynamical constraints on preferred and predicted walking frequency are explored in this article. Participants were required to walk on a treadmill at their preferred frequency, at a frequency predicted as the resonance of a hybrid pendulum-spring model of the legs, and at frequencies ±15%, ±25%, ±35% of the predicted frequency. Walking at the preferred and predicted frequencies resulted in minimal metabolic costs and maximal stability of the head and joint actions. Mechanical energy conservation was constant across conditions. The head was more stable than the joints. The joints appeared to be in service of the head in maintaining a stable trajectory. The major findings of this study suggest a complementary relationship between energetic (physiological) and stability constraints in the adoption of a preferred frequency of walking. Multiple subsystems may be involved in constraining observed macroscopic behavior in intact biological systems. The approach and results of the study imply that a useful tack in understanding how dynamical control structures arise is to study the potential criteria that serve to act as constraints on skilled movement patterns in unimpaired and impaired populations.     

Interlimb Coordination During Step-to-Step Transition and Gait Performance

Most energy spent in walking is due to step-to-step transitions. During this phase, the interlimb coordination assumes a crucial role to meet the demands of postural and movement control. The authors review studies that have been carried out regarding the interlimb coordination during gait, as well as the basic biomechanical and neurophysiological principles of interlimb coordination. The knowledge gathered from these studies is useful for understanding step-to-step transition during gait from a motor control perspective and for interpreting walking impairments and inefficiency related to pathologies, such as stroke. This review shows that unimpaired walking is characterized by a consistent and reciprocal interlimb influence that is supported by biomechanical models, and spinal and supraspinal mechanisms. This interlimb coordination is perturbed in subjects with stroke.     

Effectiveness of a Hearing Conservation and Vocal Hygiene Program for Kindergarten Children

Abstract

Noise-induced hearing loss and disorders of the voice are two potentially preventable communication disorders. This study sought to determine if young children's knowledge regarding potentially abusive hearing and voice behaviors can be changed through education. An interactive educational program-“Ears for Listening, Voice for Speaking” (ELVS)-was presented to 66 kindergarten students. A questionnaire, testing the students' knowledge regarding anatomy, abusive behaviors, and conservation practices, was administered pre- and post-ELVS participation. A statistically significant increase was found in the students' knowledge post-ELVS participation. Scores on the voice questions were lower than hearing, and, although the difference was not statistically significant, girls scored higher than boys, both pre- and post-ELVS participation. This study highlights the importance of early intervention through education in preventing noise-induced hearing loss and voice disorders.     

情绪劳动的效应、影响因素及作用机制

情绪劳动是指员工遵照一定的组织规则, 在工作场所与顾客互动过程中进行的情绪调节。研究证明情绪劳动对组织情境中一系列结果变量影响显著, 既有积极影响也有消极影响, 作用对象包括施动者员工、受动者顾客和规则制定者组织。情绪劳动与结果变量的关系受多个员工、工作和顾客特征变量的影响。资源保存理论为情绪劳动的作用机制提供了一种有力的解释。即时、短期与长期效应的整合、指向内部顾客的情绪劳动以及组织氛围的影响是未来研究值得关注的方向。     

Functional magnetic resonance imaging study of Piaget's conservation-of-number task in preschool and school-age children: a neo-Piagetian approach

Jean Piaget’s theory is a central reference point in the study of logico-mathematical development in children. One of the most famous Piagetian tasks is number conservation. Failures and successes in this task reveal two fundamental stages in children’s thinking and judgment, shifting at approximately 7 years of age from visuospatial intuition to number conservation. In the current study, preschool children (nonconservers, 5-6 years of age) and school-age children (conservers, 9-10 years of age) were presented with Piaget’s conservation-of-number task and monitored by functional magnetic resonance imaging (fMRI). The cognitive change allowing children to access conservation was shown to be related to the neural contribution of a bilateral parietofrontal network involved in numerical and executive functions. These fMRI results highlight how the behavioral and cognitive stages Piaget formulated during the 20th century manifest in the brain with age.     

Media framing of proposed nuclear reactors: An analysis of print media

Nuclear energy has received substantial recent attention, marketed as a ‘green’ solution to global climate change (GCC) with calls for new reactors. However, considerable debate exists about whether it represents a viable solution to GCC. Given the complexity and urgency of the issue, a full and balanced debate is desirable. Since media play an important role in shaping public perception, we examined print media coverage of proposed reactors in Georgia—one site in the southeastern United States, which has been the focus of such proposals. We analysed the content of editorials and news articles from two local newspapers—the Augusta Chronicle and Atlanta Journal‐Constitution. The former exclusively published pro‐nuclear opinion pieces whereas the latter published a mix of pro‐ and anti‐nuclear opinions. The majority of news articles in both newspapers generally presented balanced arguments. Pro‐ and anti‐nuclear arguments most often reflected economic and environmental benefits and risks, whereas informational text primarily detailed regulatory processes and financing. Findings suggested that informational text was not necessarily ‘neutral’, sometimes masking covert pro‐ and anti‐nuclear content. Implications for how findings might shape public opinion and strategies for shaping media and extending public deliberation are discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

The authorship of Uri Zohar: the ethics and aesthetics of the Archimedean lever

This article discusses Zohar’s subversive reflexive aesthetics, termed the “Archimedean-lever ethics,” comprised of three stages: the world rendered from one perspective; the same world rendered from a different perspective, challenging or destroying the first; and awareness of the shift of perspectives. It argues that Zohar’s creative energy, imbued with male sexuality, derives from this collision, and examines its ethical aspect in relation to Zionist values during the 1950s and 1960s. Zionism and Israel should always consider more than one perspective, being able not only to build but also to destroy (convictions, territories) in order to bring change, with destruction thus becoming a particular form of creation. However, in Zohar’s films made during the 1970s, the male sexual energy becomes an endless sexual appetite, expressed mostly through coveting gazes, which is no more than a cover up for male impotency, tantamount to Israel’s endless appetite for land.     

The Relationship between Workplace Incivility and Helping Behavior: Roles of Job Dissatisfaction and Political Skill

This article investigates the mediating role of job dissatisfaction in the relationship between employees’ perceptions of workplace incivility and their helping behavior, as well as the buffering role of political skill in this process. Three-wave, time-lagged data collected from employees and their supervisors revealed that employees’ exposure to workplace incivility diminished their helping behavior through their sense of job dissatisfaction. This mediating role of job dissatisfaction was less salient, however, to the extent that employees were equipped with political skill. For organizations, this study accordingly pinpoints a key mechanism—namely, unhappiness about their job situation—through which rude coworker treatment links to lower voluntary workplace behaviors among employees, and it reveals how this mechanism can be better contained in the presence of political skill.     

Axiomatizing Relativistic Dynamics without Conservation Postulates

A part of relativistic dynamics is axiomatized by simple and purely geometrical axioms formulated within first-order logic. A geometrical proof of the formula connecting relativistic and rest masses of bodies is presented, leading up to a geometric explanation of Einstein’s famous E = mc ². The connection of our geometrical axioms and the usual axioms on the conservation of mass, momentum and four-momentum is also investigated.     

建言效能感结构及其在员工建言行为发生中的作用

作为一种组织促进性行为, 员工建言在知识经济时代对组织的作用日益显著。学界从多角度探讨了建言的发生机制, 然而从认知的视角的研究则较为缺乏。本研究从社会认知理论视角, 构建了建言效能感结构(研究一), 并探索了建言效能感在建言行为发生中的作用(研究二)。研究一从长三角地区企业的26名基层员工中提取建言效能感关键事件, 编制初始问卷, 通过对188个样本的探索性因子分析及对另188个样本的验证性因子分析, 探索并验证了建言效能感的结构及其量表; 研究二通过对401份“员工－上级”配对样本的问卷研究显示, 一般自我效能感对建言行为有着正向影响, 且建言效能感在其中起着中介作用, 工作可得性缓冲调节建言效能感与建言行为之间的关系。