Stochastic Resonance Whole-Body Vibration Improves Postural Control in Health Care Professionals: A Worksite Randomized Controlled Trial

Slip, trip, and fall injuries are frequent among health care workers. Stochastic resonance whole-body vibration training was tested to improve postural control. Participants included 124 employees of a Swiss university hospital. The randomized controlled trial included an experimental group given 8 weeks of training and a control group with no intervention. In both groups, postural control was assessed as mediolateral sway on a force plate before and after the 8-week trial. Mediolateral sway was significantly decreased by stochastic resonance whole-body vibration training in the experimental group but not in the control group that received no training (p < .05). Stochastic resonance whole-body vibration training is an option in the primary prevention of balance-related injury at work.

Comment: Earnings Returns to Education in Urban China: A Note on Testing Differences among Groups

Comment on Wu and Xie, ASR, June 2003

Molecular control of cardiac sodium homeostasis in health and disease.

INTRODUCTION Cardiac myocytes utilize three high-capacity Na transport processes whose precise function can determine myocyte fate and the triggering of arrhythmias in pathological settings. We present recent results on the regulation of all three transporters that may be important for an understanding of cardiac function during ischemia/reperfusion episodes. METHODS AND RESULTS Refined ion selective electrode (ISE) techniques and giant patch methods were used to analyze the function of cardiac Na/K pumps, Na/Ca exchange (NCX1), and Na/H exchange (NHE1) in excised cardiac patches and intact myocytes. To consider results cohesively, simulations were developed that account for electroneutrality of the cytoplasm, ion homeostasis, water homeostasis (i.e., cell volume), and cytoplasmic pH. The Na/K pump determines the average life-time of Na ions (3-10 minutes) as well as K ions (>30 minutes) in the cytoplasm. The long time course of K homeostasis can determine the time course of myocyte volume changes after ion homeostasis is perturbed. In excised patches, cardiac Na/K pumps turn on slowly (-30 seconds) with millimolar ATP dependence, when activated for the first time. In steady state, however, pumps are fully active with <0.2 mM ATP and are nearly unaffected by high ADP (2 mM) and Pi (10 mM) concentrations as may occur in ischemia. NCX1s appear to operate with slippage that contributes to background Na influx and inward current in heart. Thus, myocyte Na levels may be regulated by the inactivation reactions of the exchanger which are both Na- and proton-dependent. NHE1 also undergo strong Na-dependent inactivation, whereby a brief rise of cytoplasmic Na can cause inactivation that persists for many minutes after cytoplasmic Na is removed. This mechanism is blocked by pertussis toxin, suggesting involvement of a Na-dependent G-protein. Given that maximal NCX1- and NHE1-mediated ion fluxes are much greater than maximal Na/K pump-mediated Na extrusion in myocytes, the Na-dependent inactivation mechanisms of NCX1 and NHE1 may be important determinants of cardiac Na homeostasis. CONCLUSIONS Na/K pumps appear to be optimized to continue operation when energy reserves are compromised. Both NCX1 and NHE1 activities are regulated by accumulation of cytoplasmic Na. These principles may importantly control cardiac cytoplasmic Na and promote myocyte survival during ischemia/reperfusion episodes by preventing Ca overload.

Multigrade teaching in primary education as a promising pedagogy for teacher education in Austria and Finland

This chapter focuses on teaching practices used in multigrade classes and the importance of them being incorporated in teacher education as promising pedagogies for future use. Multigrade classes - defined as classes in which two or more grades are taught together - are common worldwide. Hence, there is a need for teacher candidates to become familiar with how to teach in split grade classrooms. However, research on multigrade teaching as well as its development in teacher education studies has been neglected, even though multigrade teachers need special skills to organize instruction in their heterogeneous classrooms. We argue that in successful multigrade teaching practices, the heterogeneity of students is taken into account and cultivated. Based on content analysis of teacher interviews conducted in Austrian and Finnish primary schools, we recommend teaching practices such as spiral curricula, working plans, and peer learning as promising teacher education pedagogies for future multigrade class teaching. We also suggest that the professional skills required in high-quality teaching practices in multigrade teaching should be further studied by researchers and educators.

How Do Second-Generation Immigrant Students Access Higher Education? The Importance of Vocational Routes to Higher Education in Switzerland, France, and Germany

We analyse the access to different institutional pathways to higher education for second-generation students, focusing on youths that hold a higher-education entrance certificate. The alternative vocational pathway appears to compensate to some degree, compared to the traditional academic one, for North-African and Southern-European youths in France, those from Turkey in Germany, and to a lesser degree those from Portugal, Turkey, Ex-Yugoslavia, Albania/Kosovo in Switzerland. This is not the case in Switzerland for Western-European, Italian, and Spanish youths who indeed access higher education via the academic pathway more often than Swiss youths. Using youth panel and survey data, multinomial models are applied to analyse these pathway choices.