  Biologically driven non-equilibrium 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
non-equilibrium 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 non-equilibrium.
