  The calcium transport in biological systems is modelled as a
reaction-diffusion process. Nonlinear calcium waves are then simulated using a
stochastic cellular automaton whose rules are derived from the corresponding
coupled partial differential equations. Numerical simulations show
self-organized criticality in the complex calcium waves and patterns. Both the
stochastic cellular automaton approach and the equation-based simulations can
predict the characteristics of calcium waves and complex pattern formation. The
implication of locality of calcium distribution with positional information in
biological systems is also discussed.
