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. 2014 Aug 14;10(8):e1003783. doi: 10.1371/journal.pcbi.1003783

Figure 5. Stochastic and deterministic simulations exhibit similar dynamic properties.

Figure 5

A: simulated stochastic (upper panel) or deterministic (lower panel) Inline graphic oscillations at Inline graphic Inline graphic. B: a typical stochastic solution projected on the Inline graphic plane. The average Inline graphic represents the average value of Inline graphic over the 20 Inline graphic. Statistics (Inline graphic) of the initiation point (blue square), the peak (red square) and termination point (green square) are shown in the inset. 116 samples are obtained by applying a low threshold of Inline graphic and a high threshold of Inline graphic to Inline graphic. C: a typical periodic solution of the deterministic model (black curve), plotted in the Inline graphic phase space. The arrow indicates the direction of movement. Inline graphic is the slowest variable so that its variation during an oscillation is very small. This allows to treat Inline graphic as a constant (Inline graphic in this case) and study the dynamics of the model in the Inline graphic phase space. The color surface is the surface where Inline graphic (called the critical manifold). The white N-shaped curve is the intersection of the critical manifold and the surface Inline graphic. D: projection of the periodic solution to the Inline graphic plane. The red N-shaped curve is the projection to the Inline graphic plane of the white curve shown in C. The evolution of the deterministic solution exhibits three different time scales separated by green circles (labelled by a, b and c) and indicated by arrows (triple arrow: fastest; double arrow: intermediate; single arrow: slowest).