Walter Schrabi�s most recent post was examined and compared to a modified version of my uxb program using the data he presented. There is good general agreement between my use of a power fit instead of an exponential fit and my concept of a 1-compartment model compared to his 2- compartment model, and a tweak of my original program had to be used. Besides this, I don�t understand the real difference between 1 - and 2-compartment models anyway. The idea here is �take it or leave it!�