A Model of Force Generation in a Three Dimensional Toroidal Cluster of Cells

Observation of the self assembly of clusters of cells in three dimensions has raised questions about the forces that drive changes in the shape of the cell clusters. Cells that self assemble into a toroidal cluster about the base of a conical pillar have been observed in the laboratory to spontaneously climb the conical pillar. Assuming that cell cluster reorganization is due solely to surface diffusion, a mathematical model based on thermodynamics of an isothermal dissipative system is presented. The model shows that the cluster can reduce its surface area by climbing the conical pillar but at the expense of increasing its gravitational potential energy. As a result, the kinetics of the climb is affected by parameters that influence this energy competition such as the slope of the conical pillar or a parameter of the model k that gives an idea of the relative influence of the surface energy of the cluster to its gravitational potential energy.

Speaker Bio: Asha K. Nurse was born in Trinidad and Tobago. In 1998, she graduated from St. Augustine Girls' High School where she discovered her love for the sciences. She then taught high school Physics for some time in Trinidad while deciding where to continue her education. Her decision to attend Spelman College in Atlanta, GA was invaluable as she was introduced to scientific research. She also became a member of Phi Beta Kappa and earned a Bachelor of Science degree in Physics in 2005. Wanting to continue doing scientific research, she then went on to earn her doctorate degree in the Mechanics of Solids program at the School of Engineering at Brown University. Her research, guided by Professor L.B. Freund, on the mathematical modeling of self-assembly experiments sought to gain better understanding of the configurational forces that affect the morphology of self assembled clusters. She is currently a NIST-ARRA postdoctoral fellow and plans to merge both her love of teaching and research by obtaining an academic position.

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