Fig. 5. The radial root-mean-square (RMS) displacement of arginine phosphate in P. argus fibers as a function of the square root of the diffusion time. The RMS displacement is described by , where t is the diffusion time (ms). The unrestricted RMS displacement was calculated using a D value for AP of 4.054x10^-6 cm²s^-1 (Ellington and Kinsey, 1998). The effect of restriction is noted by the deviation of the radial RMS displacement values of AP in the fibers (filled squares) from the line depicting the time-dependent displacement in an unrestricted medium. Data points were calculated from the mean values of D shown in Fig. 4A.