RESEARCH INTERESTS
My research has four major areas of emphasis presently. The first area is the
documentation of radiation dispersion in rural and urban areas subsequent to release from
a nuclear accident. Reconstruction of plume dispersion from the Chernobyl accident is
permitting us to document how radionuclides are deposited in forested areas, around
buildings and avenues, and in waterways. This information will be used to refine models
for predicting fallout patterns subsequent to nuclear dispersive weapons (dirty bombs)
and other man-made or accidental releases of radiation from storage or reactor facilities.
The second area of my research is in the development of accurate methods for estimating
radiation dose in various organisms exposed to environmental radiation. This research
requires detailed mathematical and computer models to determine the energy absorbed
within tissues as a function of sources of radiation inside and outside of the body.
Radiation dosimetry is a central tenet of my third area of research, the biological/genetic
effects of radiation. I collaborate with excellent scientists (Drs. Robert J. Baker, Carleton
J. Phillips, Brenda E. Rodgers, Jeffrey W. Wickliffe and others) to assess genetic changes
associated with acute, sub-acute, and chronic doses of radiation. Methods employed
include DNA sequencing, karyology, fluorescent in-situ hybridization, micronucleus
assay, DNA-unwinding, flow cytometry, and microsatellite surveys. The genetic
information within populations may be a function of environmental factors as well as
behavioral characteristics, including mating and dispersal behavior. This is my fourth
area of research. I have developed matrix models that predict the dynamics of genetic
variation within and among structured populations. I also developed similar models for
assessing gene diversity associated with different modes of inheritance and for organelles
during and subsequent to ontogeny.