1. From the Bioengineering and Chronobiology Laboratories (R.C.H., D.E.A., A.M., M.J.F., R.S., J.R.F.), University of Vigo, Campus Universitario, Spain; and Hypertension and Vascular Risk Unit (C.C., J.E.L.), Hospital Clínico Universitario, Santiago de Compostela, Spain.