Figure 2

Time series and limit cycles for system ( 2.7 ) with kinetics ( 4.1 ) [upper row] and ( 4.3 ) [lower row], respectively. Parameter values: (a), (b) \(\sigma=0.5, \beta=0.032, \gamma=0.8, \delta=0.3\) and \(t=4{,}000\). For panels (c), (d) \(\sigma=0.25, \beta=1.05, \gamma=0.5\) at \(t=100\) and initial data \((u_{0},v_{0})=(0.25, 0.15)\).