Figure 3. Propagation of a pulse wave.

(Top) Experimental results under abundant nutrient conditions: M9 minimal medium supplemented with 4% glucose and 1% casamino acids (both ten times more concentrated than in the case of Fig. 5). (Bottom) Numerical simulations of system (2)–(3) in the case of unlimited nutrient, and a stiff response function φ. We observe the propagation of a traveling pulse with constant speed and asymmetric profile. Specific parameters are: (δ = 10⁻¹ and N ₀ = 103 (arbitrary units).