Concentration profiles for motors moving (a) inwards and (b) outwards in asterlike arrays of filaments as functions of the radial coordinate r. Parameters are for motor complexes as described by Nédélec et al. (2001), see text. The numbers of motors are (from bottom to top) N = 104 (○), 105 (⋄), 106 (▵), 107 (□), 108 (*), and 109 (▹). The profiles shown are profiles of the total motor concentration Because of the logarithmic scale, discrete data points are only indicated for small r.