Abstract #301043


The views expressed here are those of the individual authors
and not necessarily those of the ASA or its board, officers, or staff.


Back to main JSM 2002 Program page



JSM 2002 Abstract #301043
Activity Number: 17
Type: Contributed
Date/Time: Sunday, August 11, 2002 : 2:00 PM to 3:50 PM
Sponsor: Biometrics Section*
Abstract - #301043
Title: A Markov Chain Model for Reproductive Cycling Data Analysis
Author(s): Jun Zhai*+ and Richard Morris
Affiliation(s): Analytical Sciences, Inc. and NIEHS
Address: 2605 Meridian Parkway, Suite 200, Durham, North Carolina, 27713, US
Keywords: Estrous cycle ; Gibbs sampler ; Non-stationary
Abstract:

In toxicological studies, data on female rodent reproductive cycling are often used as an outcome variable. For example, some National Toxicology Program (NTP) studies routinely collect vaginal cytology slides from rats and mice, which can be used to determine daily estrous cycle stage. Analyses are typically based on summary statistics of daily data, including proportion of animals regularly cycling, average cycle length, proportion of time animals spend in each estrous stage, and number of cycles in a fixed period of time. We propose a first order non-stationary Markov chain model with transition probabilities depending on unobserved stage lengths. Estrous cycle data have four distinguishable stages: D, P, E, and M. The set of daily status (in one of these four stages) is the state space of our Markov process. We assume stage lengths are independent. A Bayesian approach is used for inference on dose effects on mean stage lengths. Gibbs sampler (implemented using BUGs software) is used to fit the model.


  • The address information is for the authors that have a + after their name.
  • Authors who are presenting talks have a * after their name.

Back to the full JSM 2002 program

JSM 2002

For information, contact meetings@amstat.org or phone (703) 684-1221.

If you have questions about the Continuing Education program, please contact the Education Department.

Revised March 2002