Models of crowding effect on phytoplankton competition for nitrogen In the previous study, we consider a chemostat model of phytoplankton competing for nitrogen taking into account effects of both intra- and interspecific crowding. Crowding can be modeled as an additive density-dependent mortality rate. Crowding effects maybe classified into intra- and interspecific crowding depending on whether …
Reflections on the use of models to study global environmental change The work of my lab revolves around the mathematical modeling to understand interactions between major elements that cycle between atmosphere, land and ocean, between life and environment. The cycle of the major elements carbon, nitrogen and phosphorus touches our existence, in terms of feeding …
Empirical Nonlinear Dynamics: Reconstructing the Dynamics of Real-World Systems from Available Data This seminar presents an empirical dynamics approach that permits available data to ‘speak first’ regarding the nature of real-world processes generating them, and thus provides valuable guidance for subsequent modeling. This data-driven approach is compatible with the classic scientific method in which “ …
The aim of Computational and Mathematical Population Dynamics 5 is to serve as a forum for researchers to exchange ideas and present mathematical results on topics including biology, ecology, environmental science, epidemiology, immunology, medical sciences, etc. In the last three decades, population dynamics have become much more approachable due to the rapid development and advances …
Spreading Mechanics and Differentiation of Astrocytes During Retinal Development In embryonic development, formation of the retinal vasculature is critically dependent on prior establishment of a mesh of astrocytes. Astrocytes emerge from the optic nerve head and then migrate over the retinal surface in a radially symmetric manner and mature through differentiation. We develop aPDE model describing …
Zika Modeling The Zika virus (ZIKV) epidemic has caused an ongoing threat to global health security and spurred new investigations of the virus. Use of epidemiological models for arbovirus diseases can be a powerful tool to assist in prevention and control of the emerging disease. In this talk, we introduce six models of ZIKV, beginning with a …
An Update on the Multi-Stage Model for Carcinogenesis The multistage model for carcinogenesis was first proposed by Armitage and Doll in 1954. There were two supporting pillars that supported the proposition. The first was that changes could be observed in normal cells on the pathway to becoming cancerous. The second support for the theory was …
Soil carbon dynamics: models and questions Soil decomposition models are critical forunderstanding future climate, providing insight into a major natural source ofcarbon dioxide. Several recent models have been proposed which explicitlyrepresent microbial processes, as well as other key chemical and physicalprocesses affecting decomposition. While soil carbon models have historically beenfirst order linear ODE's these new …
Modeling HIV persistence during suppressive therapy HIV persists in infected individuals despite prolonged antiretroviral therapy. Although the latent infection of CD4+ T cells might be a major barrier to viral eradication, other factors such as cell-to-cell viral transmission and infection of macrophages can also contribute to viral persistence. In this talk, I will discuss some recent …
Penalization of Singular Control Problems that Arise in Math Biology Optimal control problems applied to biological models tend to incorporate an objective function that increases quadratically with respect to the control. However, the principle of parsimony would lead one to assume linear dependence on the control instead. Problems of this form may have a solution …
