Figure 1.

Theoretical model underpinning the reentry vulnerability index (RVI). A: A re-entrant wavefront is blocked (RT at point P longer than AT at point D = large RVI) B: A re-rentrant wavefront conducts and enables a re-entry (RT at point P shorted than AT at point D = negative RVI). See “Methods” for a detailed description of this figure. Similar diagrams can be found in Coronel et al,⁶ Child et al,⁷ and Martin et al.¹⁰