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International Conference on Mathematical Biology and

Annual Meeting of The Society for Mathematical Biology,

July 27-30, 2009

University of British Columbia, Vancouver

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Program

Poster PS18B
Magdalena Musielak
The George Washington University
Title Nutrient Transport and Acquisition by Diatom Chains in a Moving Fluid
Abstract The role of fluid motion in delivery of nutrients to phytoplankton cells is a fundamental question in biological and chemical oceanography. Experimental data to test the contribution of advection to nutrient acquisition by phytoplankton are scarce, mainly because of the inability to visualize, record and thus imitate fluid motions in the vicinities of cells in natural flows. Steady flows, most often used in laboratory experiments, produce spatially uniform shear, and fail to capture the diffusion of momentum and vorticity, the essence of turbulence. Thus, numerical modelling plays an important role in the study of effects of fluid motion on diffusive and advective nutrient fluxes. We use the immersed boundary method to model the interaction of rigid and flexible diatom chains with the surrounding fluid and nutrients. We examine this interaction in two nutrient regimes. We also vary the length and flexibility of chains, as whether chains are straight or bent, rigid or flexible will affect their behavior in the flow and hence their nutrient fluxes. The results of numerical experiments suggest that stiff chains consume more nutrients than solitary cells. Stiff chains also experience larger nutrient fluxes compared to flexible chains, and the nutrient uptake per cell increases with increasing stiffness of the chain, suggesting a major advantage of silica frustules in diatoms.
CoauthorsLisa Fauci, Lee Karp-Boss, Peter Jumars
LocationWoodward Lobby (Wednesday-Thursday)