Mathematics Graduate Student Instructors (GSIs) have a significant impact on the teaching and learning of mathematics in post-secondary contexts through their work as instructors of record, tutors, graders, and recitation, laboratory, or discussion leaders for mathematics courses. Perhaps more importantly, GSIs are future teachers of mathematics: more than 60 percent...
We describe two combinatorial problems in the theory of automorphism groups of compact Riemann surfaces of genus two or greater: enumerate the topological actions of a finite group on surfaces and determine the set of genera of surfaces admitting such a group action, called the genus spectrum. We illustrate results...
Consider a polygon lying in the Euclidean plane with labeled edge lengths. The moduli space of polygons is the space of all polygons with the same labeled edge lengths, modulo orientation preserving isometries. It is well known that this space is generically a smooth manifold. For certain combinations of edge...
In this work we consider a mathematical and computational model for biofilm growth and nutrient utilization. In particular, we are interested in a model appropriate at a scale of interface. The model is a system of two coupled nonlinear diffusion--reaction partial differential equations (PDEs). One of these PDEs is subject...
We propose a time dependent Eulerian model for sea surface entrainment, buoyancy transport and droplet dynamics of ocean oil. The model captures the microscale vertical oil mass exchanges in the neighborhood of the sea surface. This model is in turn part of an oil fate model designed to capture oil...
In this work, we consider a convexity splitting scheme for a coupled phase field and energy equation, a modification of Stefan problem. The Stefan problem is a free boundary value problem that models the temperature in a homogeneous multiphase medium. Each phase is modeled using a heat diffusion parabolic partial...
Markov Chain Monte Carlo methods may be used to determine normalizations and moments of distributions. However, these methods may perform poorly when starting from distributions that have little overlap with the target. We develop a homotopy based iterative process of incremental importance sampling to normalize distributions when observations can only...
Microbial ecology has been transformed by metagenomics, the study of the genetic in-formation in entire communities of organisms. In the following we develop metagenomic tools arising from the classic Wasserstein metric as applied to questions regarding the diversity between microbial communities. We provide a novel proof of the characteriza-tion of...
Malaria is a vector-borne disease that has affected humans and other animals for a long time and which has shown high prevalence among different populations. During the beginning of the 20th century, Sir Ronald Ross and George Macdonald developed a model that represents the spread of malaria through the interaction...