Abstract
The aggregation of Dictysotelium amoebae is an exciting example of how biological systems can utilize pattern-formation mechanisms to accomplish needed tasks. This talk will focus on the specific issue of chemotactic motion by which is meant the biasing of cell motion by external gradients. Cells must actively sense external concentrations in space and time and use reaction-diffusion based processing schemes to make a decision about the direction of motion. How this works and what limits the achievable accuracy are important issues that can be addressed by combining analytical insights, new computational schemes and quantitative experiments.