  Chemotaxis is the process by which cells behave in a way that follows the
chemical gradient. Applications to bacteria growth, tissue inflammation, and
vascular tumors provide a focus on optimization strategies. Experiments can
characterize the form of possible chemotactic sensitivities. This paper
addresses the recovery of the chemotactic sensitivity from these experiments
while allowing for nonlinear dependence of the parameter on the state
variables. The existence of solutions to the forward problem is analyzed. The
identification of a chemotactic parameter is determined by inverse problem
techniques. Tikhonov regularization is investigated and appropriate convergence
results are obtained. Numerical results of concentration dependent chemotactic
terms are explored.
