par Lefever, René ;Horsthemke, Werner
Référence Bulletin of mathematical biology, 41, 4, page (469-490)
Publication Publié, 1979
Article révisé par les pairs
Résumé : We analyze under different environmental conditions the occurrence of bistability, i.e. of two simultaneously stable steady states, in a biological model system which describes the immunological interactions of neoplastic-target cells and cytotoxic-effector cells. As a result of environmental fluctuations such complex biological systems may undergo drastic modifications of their steady state properties. In particular, when the variance of fluctuations increases around a well defined mean value, transition phenomena appear which are absent in the usual bifurcation diagrams. The properties of the non-fluctuating systems can no longer be considered as a first approximation of the properties of the real system. Interestingly, in the case of the model, these transitions correspond to a rejection of tumor cells.