Figure 2: Geometry of motility supporting zone for simulations. (a) Generalized geometry with one part of the zone defined by an ellipse and another part defined by a second degree polynomial (e.g., filled or dashed line). Polynomials selected to be continuous with the ellipse and also with continuity of first derivative. (b) Special case with 𝑅 m a x = 𝑅 m i n and very small value of 𝐿 1 . This special case was exclusively used here.