A graphical illustration of the sensitivity of the worm count in the age-structured spatially implicit model, discussed in Results and Discussion and in SI Appendix, 2.2 Spatially Implicit Model, to varying the three free parameters in the model. The parameter c, the saturation rate of the Hollings type II functional response (SI Appendix, Eq. S.3), is varied over a 15-fold increase, from c= 5×10−10 to c= 7.5×10−9 cells−1. The parameter σ, which controls how the worms’ foraging efficiency changes with plates size (SI Appendix, Eq. S.4), is varied over a 20-fold increase, from σ= 100 to σ= 2,000 cm2. The parameter s, the rate at which bacteria is spread by farmers (SI Appendix, Eq. S.5), is varied over a 300-fold increase, from s= 7×10−11 to s= 2.1×10−8 min−1cm−2.
Shashi Thutupalli, Sravanti Uppaluri, George W. A. Constable, Simon A. Levin, Howard A. Stone, Corina E. Tarnita, and Clifford P. Brangwynne
PNAS. 2017. DOI: 10.1073/pnas.1608961114