Fig. 5. Tracheal diameters vs position in the first plasticity trial (similar patterns were observed in the other trials). Alphanumerical values along the x-axis correspond to the six measurement positions described in Fig. 2, with a being the diameter at the anterior anastomosis and f being the diameter at the posterior anastomosis. Lines are defined using spline curves. Asterisks indicate a significant effect (P<0.02) of oxygen on diameter.