Please note unusual time (11:00 a.m.) and day (Thursday) for this seminar:


Seminar Notice
 
Statistical Laboratory
Iowa State University
 
DATE AND TIME:  Thursday, November 17, 2005, 11:00 a.m.
 
PLACE:  319 Snedecor
 
SPEAKER:  Xia Xu, Department of Statistics, Iowa State University
 
TITLE:   Toxicokinetic-based survival model on analysis of toxicity data with changing dose
 
ABSTRACT
 
In toxicology studies, some data sets are dose-time-response data with changing doses over time and death/alive as response. We developed a toxicokinetic-based survival model that relates survivorship and bioaccumulation. The model assumes toxicant uptake and elimination follow a single compartment model and the hazard rate is proportional to the internal concentration. Several diagnostics methods were described for this model to check assumptions of proportional hazard and the functional form of covariates. Maximum likelihood and ordinary least square estimation were compared by comparing the estimating equations and a simulation study. The results showed that maximum likelihood is the most unbiased and efficient estimation method for this model.
 
COFFEE:  10:40 a.m., 104 Snedecor Hall
 
Seminar schedules and abstracts are available via WWW:  http://www.stat.iastate.edu/

Jeanette La Grange
Department of Statistics
102 Snedecor
Iowa State University
Ames, IA  50010-1210
515 294-3440 (office)
515 294-4040 (fax)
http://www.stat.iastate.edu/directory/staff/jeanette.html