Effects of Electromyostimulation on Knee Extensors and Flexors Strength and Steadiness in Older Adults

It is known that electromyostimulation (EMS) alone or superimposed over voluntary contraction (EV) can effectively improve muscle strength. However, the effect of this type of training on the ability to control force production at submaximal levels is unknown. The authors examined the effects of EV training on steadiness in force production of knee extensors and flexors in older adults. Forty participants, including 20 men and 20 women, 60–77 years of age, were randomly allocated into a control group (CG) and an electromyostimulation superimposed over voluntary contraction (EVG) group. The EVG performed 30 bilateral isometric knee extension and flexion contractions per session, 3 training sessions per week, for 6 weeks. The variations in force production, expressed in absolute (standard deviation [SD]) and relative (coefficient of variation [CV]) terms, were assessed in isometric contractions at 5%, 15% and 25% maximal voluntary contraction (MVC) levels. Results indicated that MVC increased in knee extension and flexion in EVG (p < .05) after the training; steadiness CV also improved at 15% MVC in knee flexion (p < .05) but no significant changes were found in knee extension and steadiness SD. The training-induced changes in MVC were not correlated to steadiness CV that might indicate different mechanisms underlying these adaptations.     

Exposure to Repetitive Tasks Induces Motor Changes Related to Skill Acquisition and Inflammation in Rats

The authors elucidate exposure-response relationships between repetitive tasks, inflammation, and motor changes with work-related musculoskeletal disorders. Using a rat model of reaching and handle pulling, they examined effects of performing a high-repetition, low-force (HRLF); low-repetition, high-force (LRHF); or high-repetition, high-force (HRHF) task (2 hr/day, 3 days/week, 12 weeks) on reach rate and force, percentage of successful reaches, duration of participation, and grip strength. Reach rate and reach force improved with HRLF, and percentage success increased in all groups in Week 9, and in HRLF and HRHF in Week 12, indicative of skill acquisition. Duration and grip strength showed force-dependent declines with task performance. A subset of HRHF rats received ibuprofen in Weeks 5–12. Ibuprofen significantly improved reach rate, reach force, and duration in treated rats, indicative of an inflammatory influence on reach performance. Ibuprofen improved percentage of successful reaches in Week 9, although this increase was not sustained. However, declines in grip strength, a nocifensive behavior, were not prevented by ibuprofen. Examination of cervical spinal cords of untreated and ibuprofen treated HRHF rats showed increased IL-1beta, an inflammatory cytokine, in neurons. These findings suggest that only a preventive intervention could have addressed all motor declines.     

Creativity,chaos, and self‐renewal in human systems

The research findings from the psychology of creativity are shown to be of considerable relevance to the study of self‐organization and self‐renewal in human systems. The characteristics of the creative person, and the nature of the creative process, particularly as they have been elaborated by Barron, are shown to be remarkably congruent with recent findings and theoretical elaborations by Abraham, Jantsch, Laszlo, Prigogine, and others in the fields of evolutionary and chaos theory. The broader social implications of chaos and evolutionary theories are fleshed out through an understanding of their characteristics in creative human systems.     

THE SECOND SPHERE AND THE STORY OF NO STORY

The author discusses Roy Schafer's ideas of the second self and second reality, as well as his consistent theme of storyteller and story. The latter theme is also explored in the context of more recent psychoanalytic influences, such as Bionian thought, trauma theory, the French approach, and the interpersonal perspective. To illustrate the idea of the nonstory in today's clinical encounters, the author presents two clinical vignettes.     

公交行业一线员工人格特质对工作绩效影响的实证分析--以工作态度作为调节变量

通过问卷调查法,探讨在工作态度调节下大五人格特质与工作绩效的关联。对1277名公交行业一线员工的研究结果表明：(1)人格特质与工作绩效有显著的相关,工作态度在这一关系中起到调节作用。在高工作态度中,人格特质与任务绩效联系较为紧密,工作绩效的良好预测指标是尽责性和外向性;在低工作态度中,人格特质与关系绩效联系较为紧密,工作绩效的良好预测指标是宜人性和外向性。(2)在高工作态度的环境中,人们更看重工作的完成;在低工作态度的环境中,人们更看重关系的协调。工作态度调节着人格特质对工作绩效的影响。     

Self-determination and functional persuasion to encourage physical activity

This research advances a novel approach to promoting physical activity, based on the principle of functional matching in persuasion, and the self-concordance (SC) of people's motivations for physical activity. We propose that SC establishes a positive or negative orientation toward the challenge inherent in physical activity, and that the maximum yield of participation will be achieved by communications that appeal to each orientation. In two studies, we compared how messages emphasizing challenge versus available social support would influence recipients’ self-reported practices of physical activity and attitudes toward a physical activity setting. As hypothesized, these messages had differential effects for recipients whose pursuit of physical activity varied in SC, such that favorable outcomes were more reliably associated with challenge-oriented messages among respondents higher in SC versus support-oriented messages among respondents lower in SC. The findings suggest the merits of using self-regulatory, compared with object- or personality-based, constructs and measures to indicate psychological functions of ongoing health-related behaviors.     

Resolving the theory of planned behaviour's ‘expectancy-value muddle’ using dimensional salience

The theory of planned behaviour is one of the most widely used models of decision-making in the health literature. Unfortunately, the primary method for assessing the theory's belief-based expectancy-value models results in statistically uninterpretable findings, giving rise to what has become known as the ‘expectancy-value muddle’. Moreover, existing methods for resolving this muddle are associated with various conceptual or practical limitations. This study addresses these issues by identifying and evaluating a parsimonious method for resolving the expectancy-value muddle. Three hundred and nine Australian residents aged 18–24 years rated the expectancy and value of 18 beliefs about posthumous organ donation. Participants also nominated their five most salient beliefs using a dimensional salience approach. Salient beliefs were perceived as being more likely to eventuate than non-salient beliefs, indicating that salient beliefs could be used to signify the expectancy component. The expectancy-value term was therefore represented by summing the value ratings of salient beliefs, an approach that predicted attitude (adjusted R ²?=?0.21) and intention (adjusted R ²?=?0.21). These findings suggest that the dimensional salience approach is a useful method for overcoming the expectancy-value muddle in applied research settings.     

Structure images of unaged martensite containing a high carbon content

Abstract

A highly tetragonal (large c/a ratio) martensite in a Fe-4 wt% Al-1·6 wt% Mn-2 wt% Calloy, which is not aged and considered to be as ‘fresh’ as possible, has been observed by high-resolution electron microscope. From the arrangement of atom rows in the [010] structure image and the corresponding electron diffraction pattern, it is concluded that carbon atoms are clustered on the (305) plane. The unit structure of these carbon-clustered regions is similar to that of the modulated structure observed in Fe-C alloys, although a periodic layer distribution of carbon atoms is not observed.