Modern biology has largely been built from a select group of model organisms, such as Drosophila, mouse, and the budding yeast. However, there exists an enormous molecular and phenotypic diversity outside of these organisms. I study the biology of ciliates - an enormously diverse yet relatively undestudied clade of single celled eukaryotes that exhibit complex developmental processes. Of specific interest is the ciliate Oxytricha trifallax (class: Spirotrichea), which undergoes global genome remodelling during sexual reproduction. This consists of massive genome fragmentation, DNA elimination, gene unscrambling, and polyploidization. Given that the packaging of DNA into nucleosomes limits its physical accessibility, it is likely that nucleosome organization must be highly dynamic during genome remodeling. I am currently investigating changes in nucleosome positioning and histone modifications that occur during Oxytricha sexual reproduction, to better understand how chromatin structure modulates genome rearrangements.
I am interested in mathematical models of disease spread, both in populations and within the body. My research focuses on HIV and Hepatitis C Virus (HCV) dynamics. The population level models I work on -- in Newark, NJ and Ho Chi Minh City, Vietnam -- aim to capture the past and current epidemic patterns of one or both infections and use them to predict future incidence and mortality. These future predictions can be modified with a series of theoretical public health interventions, and the modeling results used to assess the potential efficacy of these interventions. HIV and HCV infections can have potentiating effects on each other at the population level and also at the within-host level. My within-host work aims to model these potentiating effects with an eye to identifying optimal treatment strategies for coinfected patients.
Humans exact change on the food-webs of which they are part, but altered food-webs subsequently affect human communities. I think (as many more qualified people have before me) that quantitatively linking both ecological and economic processes to make explicit the connection between human and non-human communities would be a valuable addition to the discourse surrounding natural resource use and conservation, and a basis for fascinating ecological questions. So, I'm hoping to address applied problems (e.g. problems due to predators, livestock, fishing, and agricultural practices) by understanding the theoretical ecological (and sometimes economic) principles which underlie and perpetuate these issues.
Catherine first encountered collective behaviour as an undergraduate in zoology, where she developed an interest in behavioural economics and decision making in animal groups. As a second year graduate student she is working on understanding how the level of variability in an environment affects the the evolution of collectives. She has an inordinate fondness for social insects and is particularly interested in how behavioural variation within insect colonies can influence the outcome of collective decision making.
I am interested in understanding how nutrient losses are coupled with disturbances in tropical landscapes. Specifically, I am working in tropical savanna to understand the implications of fire driven nutrient losses for the recovery of forests. Within savanna, I am also exploring the role that elephants play in driving changes in vegetation structure and biogeochemical patterns that are coupled with fire. Hopefully these studies will help us to better understand how disturbance legacies arise and what is required for ecosystem recovery following extensive disturbance
I'm interested in the effects of sexual selection on hybridization and speciation. Sexual selection plays a major role in reproductive isolation between species, especially when postzygotic isolation is weak. Theoretically, drift in sexually selected traits, or novel combinations of existing sexually selected traits achieved through hybridization, could result in speciation. My research focuses on identifying the genetic basis of sexually selected traits in the freshwater fish group Xiphophorus and understanding the effects of sexual selection on patterns of hybridization in this genus.