On the performance of existing acoustic energy models when applied to multi-purpose performance halls

Acoustical measurements were done in two multi-purpose performance halls in the present study. The measured data are compared with predictions from three acoustic energy models in existing literature derived for churches and large reverberant theatres. Results show that the model suitable for the present multi-purpose performance halls is the one which takes into account the time difference between direct sound arrival and onset time of reverberant sound decay. However, unlike the church cases, the time difference appears to have no direct definite relationship with the source-receiver distance alone. A method for the prediction of time difference is then proposed for multi-purpose performance hall application. In addition, the prediction of the late reflected energy is not satisfactory, and this deficiency is the main problem leading to the inaccurate estimation of clarity, definition and centre time in the present study

Phospholemman: a novel cardiac stress protein.

Phospholemman (PLM), a member of the FXYD family of regulators of ion transport, is a major sarcolemmal substrate for protein kinases A and C in cardiac and skeletal muscle. In the heart, PLM co-localizes and co-immunoprecipitates with Na(+)-K(+)-ATPase, Na(+)/Ca(2+) exchanger, and L-type Ca(2+) channel. Functionally, when phosphorylated at serine(68), PLM stimulates Na(+)-K(+)-ATPase but inhibits Na(+)/Ca(2+) exchanger in cardiac myocytes. In heterologous expression systems, PLM modulates the gating of cardiac L-type Ca(2+) channel. Therefore, PLM occupies a key modulatory role in intracellular Na(+) and Ca(2+) homeostasis and is intimately involved in regulation of excitation-contraction (EC) coupling. Genetic ablation of PLM results in a slight increase in baseline cardiac contractility and prolongation of action potential duration. When hearts are subjected to catecholamine stress, PLM minimizes the risks of arrhythmogenesis by reducing Na(+) overload and simultaneously preserves inotropy by inhibiting Na(+)/Ca(2+) exchanger. In heart failure, both expression and phosphorylation state of PLM are altered and may partly account for abnormalities in EC coupling. The unique role of PLM in regulation of Na(+)-K(+)-ATPase, Na(+)/Ca(2+) exchanger, and potentially L-type Ca(2+) channel in the heart, together with the changes in its expression and phosphorylation in heart failure, make PLM a rational and novel target for development of drugs in our armamentarium against heart failure. Clin Trans Sci 2010; Volume 3: 189-196