1. From the Department of Biomedical Sciences (F.H.F., S.L., E.M.C., N.F.O., R.F.G.) and Laboratory of Solid State Physics and Department of Mechanical and Aerospace Engineering (E.B.), Cornell University, Ithaca, NY; Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany (S.L., E.B.); Institute Non Lineáire de Nice, Valbonne, France (V.K.); and Laboratoire de Physique, Ecole Normale Supérieure de Lyon, Lyon, France (A.P.).