Figure 6.

Distribution of flux solutions during replicate fitting for the standard (○) and elevated (•) O₂ datasets. A, Net fluxes. B, Exchange [0,1] fluxes. The best (lowest sum of squared residuals) 25 solutions for each dataset are shown, with each point representing a single solution. Exchange fluxes (Xch [0,1]) are expressed on a normalized scale following hyperbolic transformation, defined by Xch [0,1] = J^Xch/(1 + J^Xch), where J^Xch is the true exchange flux. Net (J), exchange, forward (J^f), and reverse (J^r) fluxes are related by J = J^f − J^r and J^Xch = min (J^f, J^r) (Wiechert et al., 2001).