Palestras e Seminários
29/11/2024
15:30
Sala 4-001
Palestrante: Clarice Demétrio
Responsável: Ricardo Sanders Ehlers (Este endereço de email está sendo protegido de spambots. Você precisa do JavaScript ativado para vê-lo.)
Modo: Presencial
Abstract: We consider discrete mortality data for groups of individuals observed over time. The fitting cumulative mortality curves as a function of time involves the longitudinal modeling of the multinomial response. Typically such data exhibit overdispersion, that is greater variation than predicted by the multinomial distribution. To model the extra-multinomial variation (overdispersion) we consider a Dirichlet-multinomial model, a random intercept model, and a random intercept and slope model. We construct asymptotic and robust covariance matrix estimators for the regression parameter standard errors. Applying this model to a specific insect bioassay of the fungus Beauveria bassiana, we note some simple relationships in the results and explore why these are simply a consequence of the data structure. Fitted models are used to make inferences on the effectiveness of different fungus isolates. The results are compared with a simple empirical analysis to provide recommendations for the field use of this fungus as a biological control.
