title: Effective temperature of red-blood-cell membrane fluctuations.
abstract: Biologically driven nonequilibrium fluctuations are often characterized by their non-Gaussianity or by an "effective temperature", which is frequency dependent and higher than the ambient temperature. We address these two measures theoretically by examining a randomly kicked particle, with a variable number of kicking motors, and show how these two indicators of nonequilibrium behavior can contradict. Our results are compared with new experiments on shape fluctuations of red-blood cell membranes, and demonstrate how the physical nature of the motors in this system can be revealed using these global measures of nonequilibrium.
authors.affiliation: Department of Chemical Physics, The Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Eyal
authors.initials: E
authors.lastname: Ben-Isaac
authors.forename: Yongkeun
authors.initials: Y
authors.lastname: Park
authors.forename: Gabriel
authors.initials: G
authors.lastname: Popescu
authors.forename: Frank L H
authors.initials: FL
authors.lastname: Brown
authors.forename: Nir S
authors.initials: NS
authors.lastname: Gov
authors.forename: Yair
authors.initials: Y
authors.lastname: Shokef
mesh_terms: D003198:Computer Simulation; D004910:Erythrocyte Membrane / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D008560:Membrane Fluidity / Q000502:physiology; D008954:Models, Biological; D013314:Stress, Mechanical; D013696:Temperature