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Exploiting ecology in drug pulse sequences in favour of population reduction

Fig 3

Which value of s gives the lowest population minimum for fixed t_r?

a) Lowest population minimum n_min for a single pulse with constant τ = 60 for all possible pulse shape parameters t_r and s. The optimal skewness s_o = 2t_o/(τ − t_r) − 1 which gives the smallest n_min for each t_r is marked in white, while the gray (dashed) line marks the skewness , where n_min has dropped to its smallest value across t_r. The constant contours (dotted lines) serve as guides to the eye. b-d) Explaining t_o (c, cf. b) and (d), the timescales for which the (high) environment is not more effective than the (low) environment. In b) is longer than t_o: the population (black) starts growing during the (low) environment, even though the wild type (blue dotted) decays, as the more resistant species (red) is not affected by the antibiotic. In c), and so the total population keeps decaying. d) If and the pulse ends there, a minimal n is achieved, while for n grows again.

doi: https://doi.org/10.1371/journal.pcbi.1005747.g003