My research interests include continuum mechanics, PDE's, and mathematical applications to biology, specifically, the relationship between the three dimensional structures of biological molecules, cellular function, and locomotion.

Locomotion of C. elegans

The Department of Mathematics and Statistics at James Madison University has supported the creation of the Wiggling Organisms Research and Modeling (WORM) Lab where we are currently studing the locomotion and behavior of C. elegans (to play movies, double click on the image).

The WORM Lab will soon be looking to hire student researchers so please check back soon for application information.

Dynamics of Torsional Stress in DNA

I model the transport of transciptional stress in DNA as an elastic rod at low Reynolds number (to play the movies below, double click on the image).

Here, the blue line represents the centerline of the rod, or DNA, and the red line represents the imaginary line traced on the surface of the rod by one of the local directors, showing the dynamic change in twist.

Manuscript: Strawbridge, E. M. (2009) "The Mechanics, Dynamics, and Structurs of DNA." PhD Thesis. University of California, Davis.

Surface Traction on Elastic Rods

Slender bodies, such as DNA, C. elegans, or bacterial flagella are often modeled as then elastic bodies immersed in a viscous fluid using the Kirchhoff rod theory combined with resistive force theory. I study the explicit relationship between these two theories and the thresholds at which they might break down in biologically relavent cases.

Journal Article: Strawbridge, E. M. and Wolgemuth, C. (2012) "Surface Traction and the Dynamics of Elastic Rods at Low Reynolds Number." Physical Review E. (86) 031904.

Genomic Distributions of Inverted Repeats in Yeast

I am also engaged in studying the genomic distribution of inverted repeats with the potential for cruciformation. This work provides upper bound cutoffs for imperfect inverted repeats within genomic DNA, beyond which, cruciform extrusion is highly improbable. I then analyze the distributions and attributes of these IRs.

I am also interested in the competition of clusters of extrusionally susceptible inverted repeats and other structures including SIDD. This work takes an equilibrium statistical mechanical approach. These projects are in collaboration with the Benham Lab at the UC Davis Genome Center.

Journal Article: Strawbridge E. M., Benson, G., Gelfand, Y., and Benham, C. J. (2010) "Genomic Distribution of Inverted Repeats in Saccharomyces cerevisea." Current Genetics" (56) 321-340.

The Impact of Disease Control Strategies on the Spread of STIs

A wide range of factors can impact the spread of sexually transmitted diseases including, but not limited to, vaccination, voluntary testing strategies, and STI prevention tools such as condoms. Even human culture and society can impact the spread of disease by its attitudes towards sex and disease. I am interested in the interplay between these human factors and the spread of sexually transmitted infections (STIs).

Journal Article: Podder, C. N., Shormi, O., Gumel, A. B., and Strawbridge, E. (2011) "Mathematical Analysis of a Model for Assessing the Impact of Antiretroviral Therapy, Voluntary Testing, and Condom Use in Curtailing HIV." Differential Equaiotns and Dynamical Systems (19) 283-302.

Workshop Proceedings: Alimadad, A., M. et al. (2006) "Report on the Impact of HIV Testing on the Spread of HIV Infection." Proceedings of the 10th PIMS Problem Solving Workshop, IRMACS Centre, Simon Frasier University.

Student Manuscript: Steinworth, B. M. (Advisor: E. Strawbridge) (2012) "A Mathematical Model of the Spread of HPV." (in prep.)

Student Research Poster: Steinworth, B. M. and Appael, N. (Advisor: E. Strawbridge) (2012) "A Mathematical Model of the Spread of Human Papillomavirus." Chicago Area Undergraduate Research Symposium.

Student Research Poster: Steinworth, B. M. (Advisor: E. M. Strawbridge) (2011) "A Natural History Model of the Spread of Human Papillomavirus in MSM Populations." Chicago Area Undergraduate Research Symposium.