Pattern dynamics in inhomogeneous active media
We study pattern dynamics in inhomogeneous active media described by a reaction–diffusion model. This is done by means of numerical simulations in one-, two- and three-dimensional systems with radial symmetry. We consider inhomogeneities corresponding to the space variation of the (nonlinear) reaction characteristic of the system. Two different problems are treated: a bistable domain immersed in an oscillatory medium and an oscillatory domain immersed in an excitable medium. The different complex behaviours arising in these systems are studied.
Summary: A medium containing propamidine is described which has high selective activity for the species Bacillus anthracis. The spore form of the organism is essential as inoculum for the medium.