Exploiting ecology in drug pulse sequences in favour of population reduction - Fig 2

Top: Inset: Schematic of the two-species model: wild-type w and resistant r grow logistically at rates λ_w or λ_r, decay at rate δ and switch between states at rates μ_w or μ_r, respectively. Main figure: Time-dependent antibiotic pulse shape with the three parameters τ, t_r, and the skewness s as before. During t_r the antibiotic concentration c(t) > MIC_r of the more resistant species ((high) environment), while during the entire treatment duration τ, c(t) > MIC_w ((low) and (high) environment). Initially, the system is in the stress-free environment (free). Bottom: Dynamical landscapes in population phase space corresponding to these three different environments in antibiotic concentration:(high) environment, with one attractive fixed point (red dot) at n = 0; (low) environment, with a saddle point at n = 0 and an attractive fixed point on the r axis; (free) environment: with unstable fixed point at n = 0 and stable fixed point close to the w axis, , which we use as the initial configuration.