Model B, Case 1: Temporal behaviour of the PER protein with miRNA regulation. The degradation rate of the miRNA is kept constant at c2 = 0.029, and the volume is fixed at 100. In (a) the red curve shows the variation of PER in the absence of regulation, while the blue curve corresponds to regulation with c1 = 0.3 h-1, c3 = 0.08 h -1 and c4 = 0.01 h-1. The green curve has parameters c1 = 0.5 h-1, c3 = 0.1 h-1 and c4 = 0.05 h-1. (b) and (c) are expanded views of (a).