Beta-binomial/Poisson regression models for repeated bivariate counts

We analyze data obtained from a study designed to evaluate training effects on the performance of certain motor activities of Parkinson`s disease patients. Maximum likelihood methods were used to fit beta-binomial/Poisson regression models tailored to evaluate the effects of training on the numbers of attempted and successful specified manual movements in 1 min periods, controlling for disease stage and use of the preferred hand. We extend models previously considered by other authors in univariate settings to account for the repeated measures nature of the data. The results suggest that the expected number of attempts and successes increase with training, except for patients with advanced stages of the disease using the non-preferred hand. Copyright (c) 2008 John Wiley & Sons, Ltd.

Deactivation of Ferrylmyoglobin by Vanillin as Affected by Vanillin Binding to beta-Lactoglobulin

Vanillin was found to be efficient as a deactivator of ferrylmyoglobin with a second-order rate constant of k(2) = S7 +/- 1 L mol(-1) s(-1) for reduction to metmyoglobin with Delta H(double dagger) = 58.3 +/- 0.3 kJ mol(-1) and Delta S(double dagger) = -14 +/- 1 J mol(-1) K(-1) in aqueous pH 7.4 solution at 25 degrees C. Binding to beta-lactoglobulin (AG) was found to affect the reactivity of vanillin at 25 degrees C only slightly to k(2) = 48 +/- 2 L mol(-1) s(-1) (Delta H(double dagger) = 68.4 +/- 0.4 kJ mol(-1) and Delta S(double dagger) = 17 +/- 1 J mol(-1) K(-1)) for deactivation of ferrylmyoglobin. Binding of vanillin to beta LG was found to have a binding stoichiometry vanillin/beta LG > 10 with K(A) = 6 x 10(2) L mol(-1) and an apparent total Delta H degrees of approximately -38 kJ mol(-1) and Delta S degrees = -S5.4 +/- 4J mol(-1) K(-1) at 25 degrees C and Delta C(p), (obs) = -1.02 kJ mol(-1) K(-1) indicative of increasing ordering in the complex, as determined by isothermal titration microcalorimetry. From tryptophan fluorescence quenching for beta LG by vanillin, approximately one vanillin was found to bind to each beta LG far stronger with K(A) = 5 x 10(4) L, mol(-1) and a Delta H degrees = 10.2 kJ mol(-1) and Delta S degrees = 55J mol(-1) K(-1) at 25 degrees C. The kinetic entropy/enthalpy compensation effect seen for vanillin reactivity by binding to beta LG is concluded to relate to the weakly bound vanillin oriented through hydrogen bonds on the beta LG surface with the phenolic group pointing toward the solvent, in effect making both Delta H(double dagger) and Delta S(double dagger) more positive. The more strongly bound vanillin capable of tryptophan quenching in the fiLG calyx seems less or nonreactive.