Electromagnetic wave propagating along a space curve

Using the thin-layer approach, we derive the effective equation for the electromagnetic wave propagating along a space curve. We find intrinsic spin-orbit, extrinsic spin-orbit and extrinsic orbital angular momentum and intrinsic orbital angular momentum couplings induced by torsion, which can lead to geometric phase, spin and orbital Hall effects. And we show the helicity inversion induced by curvature that can convert the right-handed circularly polarized electromagnetic wave into left-handed polarized one, vice verse. Finally, we demonstrate that the gauge invariance of the effective dynamics is protected by the geometrically induced gauge potential

Policies and Practices of Professional Development in China: What do Early Childhood Teachers Think?

This paper focuses on early childhood teachers’ professional development in China. It reports a study which aims to elicit twelve in-service early childhood teachers’ perspectives of the values and issues of professional development policies and the learning opportunities they experienced. Two themes arising from the study are addressed, namely the teachers’ positive responses to the government aspirations for enhancing teaching in early childhood education, and the complexities of the organizational and role structures of the early childhood community in ChangChun where the study took place. An important aspect of the teachers’ perspectives of their professional development, which connects up to the early childhood environment in ChangChun, is the view that professional development was oriented to their own employment continuity. Teachers’ learning was perceived as a useful means to offset the insecurity of their careers, but not closely related to children’s learning

Progressive decay of Ca2+ homeostasis in the development of diabetic cardiomyopathy

BACKGROUND: Cardiac dysfunction in diabetic cardiomyopathy may be associated with abnormal Ca(2+) homeostasis. This study investigated the effects of alterations in Ca(2+) homeostasis and sarcoplasmic reticulum Ca(2+)-associated proteins on cardiac function in the development of diabetic cardiomyopathy. METHODS: Sprague–Dawley rats were divided into 4 groups (n = 12, each): a control group, and streptozotocin-induced rat models of diabetes groups, examined after 4, 8, or 12 weeks. Evaluations on cardiac structure and function were performed by echocardiography and hemodynamic examinations, respectively. Cardiomyocytes were isolated and spontaneous Ca(2+) spark images were formed by introducing fluorescent dye Fluo-4 and obtained with confocal scanning microscopy. Expressions of Ca(2+)-associated proteins were assessed by Western blotting. RESULTS: Echocardiography and hemodynamic measurements revealed that cardiac dysfunction is associated with the progression of diabetes, which also correlated with a gradual but significant decline in Ca(2+) spark frequency (in the 4-, 8- and 12-week diabetic groups). However, Ca(2+) spark decay time constants increased significantly, relative to the control group. Expressions of ryanodine receptor 2 (RyR2), sarcoplasmic reticulum Ca(2+)-2ATPase (SERCA) and Na(+)/Ca(2+) exchanger (NCX1) were decreased, together with quantitative alterations in Ca(2+)regulatory proteins, FKBP12.6 and phospholamban progressively and respectively in the diabetic rats. CONCLUSIONS: Ca(2+) sparks exhibited a time-dependent decay with progression of diabetic cardiomyopathy, which may partly contribute to cardiac dysfunction. This abnormality may be attributable to alterations in the expressions of some Ca(2+)-associated proteins