title: Nonequilibrium phase transition in a self-activated biological network.
abstract: We present a lattice model for a two-dimensional network of self-activated biological structures with a diffusive activating agent. The model retains basic and simple properties shared by biological systems at various observation scales, so that the structures can consist of individuals, tissues, cells, or enzymes. Upon activation, a structure emits a new mobile activator and remains in a transient refractory state before it can be activated again. Varying the activation probability, the system undergoes a nonequilibrium second-order phase transition from an active state, where activators are present, to an absorbing, activator-free state, where each structure remains in the deactivated state. We study the phase transition using Monte Carlo simulations and evaluate the critical exponents. As they do not seem to correspond to known values, the results suggest the possibility of a separate universality class.
authors.affiliation: Equipe de Recherche sur les Relations Matrice Extracellulaire-Cellules (ERRMECe), Département de Biologie, Université de Cergy-Pontoise, Boîte Postale 222, 2 Avenue A. Chauvin, 95302 Cergy-Pontoise Cedex, France. hugues.berry@bio.u-cergy.fr
authors.forename: Hugues
authors.initials: H
authors.lastname: Berry
mesh_terms: D000495:Allosteric Site; D000818:Animals; D001695:Biology; D055592:Biophysical Phenomena; D001703:Biophysics; D002468:Cell Physiological Phenomena; D004058:Diffusion; D004330:Drosophila; D004798:Enzymes / Q000737:chemistry; D046911:Macromolecular Substances; D008962:Models, Theoretical; D009010:Monte Carlo Method; D013997:Time Factors
chemical_list: D004798:Enzymes; D046911:Macromolecular Substances