=?utf-8?B?UkU6IFVucmVhc29uYWJsZSBWU1MgZXN0aW1hdGU=?=

From: =?utf-8?B?R2liaWFuc2t5LCBMZW9uaWQ=?= <gibianskyl@globomax.com> Subject: =?utf-8?B?UkU6IFVucmVhc29uYWJsZSBWU1MgZXN0aW1hdGU=?= Date: Mon, 7 May 2001 14:59:27 -0400 Yes, that is true. But with the parameterization KA=THETA(1)*EXP(ETA(1)) ALPHA=KA+THETA(2)*EXP(ETA(2)) BETA=ALPHA+THETA(3)*EXP(ETA(3)) you may have strongly correlated ETAs, and this correlation will be an artifact of the parameterization. Moreover, if you rewrite it as KA=THETA(1)*EXP(ETA(1)) ALPHA=THETA(1)*EXP(ETA(1))+THETA(2)*EXP(ETA(2)) BETA=THETA(1)*EXP(ETA(1)) +THETA(2)*EXP(ETA(2))+THETA(3)*EXP(ETA(3)) you will see that it will be hard to interpret the meaning of ETA2 and ETA3. Also, absorption often is not well-defined, with large OMEGA. With the parameterization above, you will have all three ETAs poorly defined in this case. As to the individual estimates, population inequality should "provide support" to the corresponding inequalities on the individual's level. Flip-flop kinetics results from the identifiability problem, when you do not have any means to distinguish between the exponent terms in the equation. Population inequality will most likely remove this problem. Leonid