NLIN procedure

Figure 3.7 Scatter plot of log-thermometer resistance as a function of temperature and model predicted fit using Eq. (3.83). Starting values were 01 = —5, 02 = 6000, 03 = 344. Model was fit using the Gauss-Newton method within the NLIN procedure in SAS.

Figure 3.12 Model predicted fit and 95% confidence band for data pre-sented in Table 3.5. A 1-compartment model with absorption was fit to the data using the Levenberg Marquardt algorithm within the NLIN procedure in SAS. Starting values were 100 L, 1.0 per hour, and 0.05 per hour for Vd, Iq, and kio, respectively.

The plasma /8-carotene-dg and retinol-d4 concentration-time data were described using an empirical multiexponential description of the data using weighted, nonlinear least squares regression and the SAS NLIN procedure. Each observation was weighted by the reciprocal of its predicted value. 

Another approach for the determination of the kinetic parameters is to use the SAS NLIN (NonLINear regression) procedure (SAS, 1985) which produces weighted least-squares estimates of the parameters of nonlinear models. The advantages of this technique are that (1) it does not require linearization of the Michaelis-Menten equation, (2) it can be used for complicated multiparameter models, and (3) the estimated parameter values are reliable because it produces weighted least-squares estimates. 

Radionuclide Labeling of Blood Components. Autologous platelets were isolated, labeled with nlIn, and reinjected 24 to 48 h prior to the experiment. Because of the fragility of goat red blood cells and the difficulty in separating platelets from these cells, the following procedures were developed to prevent hemolysis and to allow isolation of platelets ... 

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