Fig. 1.

Model Definition and Properties. a Setup of the competitive interaction model between PR-B and inflammation where each variable has a growth term and acts to inhibit and deplete the other. b A setting of the phase space when k>i and b=0.5 where probability of labor is equal to 0.5 indicated by the shaded region, the basin of attraction, about the laboring equilibrium point. c A setting of the phase space when k=i where regardless of the value of b the probability of labor is equal to 1. The blue and orange lines are the null clines and correspond to the lines produced when we set $\frac{\mathit{\text{dB}}}{\mathrm{d\tau }}=0$ and $\frac{\mathit{\text{dI}}}{\mathrm{d\tau }}$=0. d The dependence of the probability of labor upon the parameter values b and i for a k fixed at 1 and the model used to make predictions