Electrical and mechanical response of skeletal muscle to electrical stimulation after acute passive stretching in humans: a combined electromyographic and mechanomyographic approach

Two mechanisms have been suggested to explain stretching-induced maximum force depression: a mechanical alteration in the stretched muscle and an impairment of neural activation. Electrical stimulation allows standardization of the level of muscle activation without being limited by neural control. The aim of this study was to evaluate the stretching-induced changes in the electrical and mechanical properties of muscle during electrically elicited contractions. Twelve participants (age 22 +/- 1 years; body mass 75 +/- 2 kg; stature 1.79 +/- 0.02 m; mean +/- standard error) underwent six electrical stimulations of the medial gastrocnemius muscle before and after stretching. During the contractions, surface electromyogram (EMG) and mechanomyogram (MMG) were recorded simultaneously together with force. After stretching we found: (i) no differences in EMG parameters; (ii) MMG amplitude decreased by 4 +/- 1% (P < 0.05); and (iii) the peak force, the peak rate of force development, and the acceleration peak of force development decreased by 12 +/- 3%, 14 +/- 1%, and 24 +/- 5%, respectively (P < 0.05). In conclusion, acute passive stretching did not change EMG properties but altered the mechanical characteristics of the contracting muscle. Indeed, muscle force-generating capacity and stiffness of the muscle-tendon unit were significantly impaired.     

The Potential of Conjoint Analysis for Communication Research

Surveys on choices oftentimes rely on Likert-type scales. However, they prevent researchers from identifying the relative importance of different stimulus features for the choice decision. Here, it is shown that conjoint analysis offers a variety of advantages emerging from its use of questions that force the subject to trade off conflicting attribute levels. This study discusses some problems of Likert-type scale measures and shows when conjoint analysis may solve some of these problems. Differences between measurements are illustrated in a uses and gratifications study, assessing convergent validity on Likert-type scale measures with traditional conjoint analysis and choice-based conjoint analysis. Results show that subjects prefer “cognitive needs” by Likert-type scale measures against “tension release needs” by both conjoint analyses. The different outcome is independent from linguistic variation and from dual-process models of information processing. Implications for communication research are discussed.     

Discrimination of Biomechanically Possible and Impossible Hand Movements at Birth

The development of human body perception has long been investigated, but little is known about its early origins. This study focused on how a body part highly relevant to the human species, namely the hand, is perceived a few days after birth. Using a preferential‐looking paradigm, 24‐ to 48‐hr‐old newborns watched biomechanically possible and impossible dynamic hand gestures (Experiment 1, N = 15) and static hand postures (Experiment 2, N = 15). In Experiment 1, newborns looked longer at the impossible, compared to the possible, hand movement, whereas in Experiment 2 no visual preference emerged. These findings suggest that early in life the representation of the human body may be shaped by sensory‐motor experience.     

Changing classroom culture,curricula, and instruction for proof and proving: how amenable to scaling up,practicable for curricular integration,and capable of producing long-lasting effects are current interventions?

This paper is a commentary on the classroom interventions on the teaching and learning of proof reported in the seven empirical papers in this special issue. The seven papers show potential to enhance student learning in an area of mathematics that is not only notoriously difficult for students to learn and for teachers to teach, but also critically important to knowing and doing mathematics. Although the seven papers, and the intervention studies they report, vary in many ways—student population, content domain, goals and duration of the intervention, and theoretical perspectives, to name a few—they all provide valuable insight into ways in which classroom experiences might be designed to positively influence students’ learning to prove. In our commentary, we highlight the contributions and promise of the interventions in terms of whether and how they present capacity to change the classroom culture, the curriculum, or instruction. In doing so, we distinguish between works that aim to enhance students’ preparedness for, and competence in, proof and proving and works that explicitly foster appreciation for the need and importance of proof and proving. Finally, we also discuss briefly the interventions along three dimensions: how amenable to scaling up, how practicable for curricular integration, and how capable of producing long-lasting effects these interventions are.     

The family caregiver after the institutionalization of the dependent elderly relative

The objective of this study was to assess the relationship between the institutionalization of a dependent elderly relative and the family caregiver’s mental health, quality of life and caregiving satisfaction. We present data from 140 family caregivers caring for elderly family members, of whom 77 continued to live with family members and 63 had been institutionalized. We evaluated the factors influencing the decision to institutionalize the dependent relative, the effect of institutionalization on the caregiver’s psychological well-being and quality of life and the impact of strategies to find the meaning and cope with the relative’s placement on the caregiver’s emotional health and quality of life. Care does not end after institutionalization, but the stressors the caregiver faces change. Our results suggest that finding meaning increases satisfaction and reduces feelings of overload. They show that after institutionalization, stressors affecting caregivers are partly relieved, and that finding meaning increases the caregiver’s satisfaction, while decreasing the degree of overload. Our data, further, indicates that a good relationship and cooperation between the staff of the institution and the family are important to improve the caregivers’ emotional health and quality of life, and consequently, the quality of life of the dependent elderly relative.     

Civil society and control of corruption: Assessing governance of Romanian public universities

Romania is perceived as the most corrupt EU member state according to Transparency International Corruption Perception Index. In 2008–2009, a grassroots coalition of civil society organizations and education stakeholders created the Coalition for Clean Universities which organized the first assessment of integrity of the Romanian higher education system, The Coalition evaluated 42 state universities on the basis of an original methodology, in terms of Administrative Integrity, Academic Integrity, Democratic Governance, Academic Governance and Sound Finance for a time internal of one academic year. The evaluation found systemic problems in the organization and functioning of university life, and attributed them to the failure to build accountability systems at university level following decentralization of higher education after 1989. The results, in the form of a ranking of universities, were made public and hotly debated, creating a major incentive for universities to compete for a better public image, and therefore for reform of their practices.     

The European university landscape: A micro characterization based on evidence from the Aquameth project

This paper provides a new and systematic characterization of 488 universities, from 11 European countries: Finland, France, Germany, Hungary, Italy, Netherlands, Norway, Portugal, Spain, Switzerland and UK. Using micro indicators built on the integrated Aquameth database, we characterize the European university landscape according to the following dimensions: history/foundation of university, dynamics of growth, specialization pattern, subject mix, funding composition, offer profile and productivity.     

Adolescents’ future wishes and fears in their acculturation process

In this study we aim at learning about adolescents’ future fears and wishes from different cultural origins with a view to finding implications for intervention in the furthering of their satisfaction and social integration in their acculturation process. The study sample comprised 938 secondary school students—64.4% Spanish, 19.7% South American and 12.8% African. Wishes and fears were evaluated by means of two open questions and the answers were categorized following traditional content analysis methodology. Results show that the adolescents wish for a satisfactory job, family and economic situation, and that they are concerned about aspects such as their own health and that of their family, the possibility of having a precarious job, isolation from their family of origin, and not forming a family. The findings also allow us to give differential profiles according to the cultural origin of the adolescents.     

阅读使人明理

有人曾说,"写作"是人类创造美的天赋,那么"阅读"就是这种天赋的延伸。通过阅读,我们能涤荡灵魂,体会我们未曾体验过的人生。请看本刊来自德国的实习生埃琳娜是因何与书结缘,如何通过阅读改变自己的人生轨迹。