Effect Of Mirthful Laughter On Vascular Function

In contrast to the well-established scientific evidence linking negative emotional states (e.g., depression, anxiety, or anger) to increased risk for cardiovascular disease, much less is known about the association between positive emotional states (e.g., laughter, happiness) and cardiovascular health. We determined the effects of mirthful laughter, elicited by watching comic movies, on endothelial function and central artery compliance. Seventeen apparently healthy adults (23 to 42 years of age) watched 30 minutes of a comedy or a documentary (control) on separate days (crossover design). Heart rate and blood pressure increased significantly while watching the comedy, whereas no such changes were seen while watching the documentary. Ischemia-induced brachial artery flow-mediated vasodilation (by B-mode ultrasound imaging) increased significantly after watching the comedy (17%) and decreased with watching the documentary (-15%). Carotid arterial compliance (by simultaneous application of ultrasound imaging and applanation tonometry) increased (10%) significantly immediately after watching the comedy and returned to baseline 24 hours after the watching, whereas it did not change significantly throughout the documentary condition. Comedy-induced changes in arterial compliance were significantly associated with baseline flow-mediated dilation (r = 0.63). These results suggest that mirthful laughter elicited by comic movies induces beneficial impact on vascular function. (C) 2010 Elsevier Inc. All rights reserved. (Am J Cardiol 2010;106:856-859)Kinesiology and Health Educatio

Eclipsing Light-Curve Asymmetry for Black-Hole Accretion Flows

We propose an eclipsing light-curve diagnosis for black-hole accretion flows. When emission from an inner accretion disk around a black hole is occulted by a companion star, the observed light curve becomes asymmetric at ingress and egress on a time scale of 0.1-1 seconds. This light-curve analysis provides a means of verifying the relativistic properties of the accretion flow, based on the special/general relativistic effects of black holes. The ``skewness'' for the eclipsing light curve of a thin disk is $\sim 0.08$, whereas that of a slim disk is $\sim 0$, since the innermost part is self-occulted by the disk's outer rim.Comment: 7 pages, 4 figures, PASJ accepte