Figure 9:

The effect of biological response uncertainty coupled with the uncertainty in the mechanical behavior for the two age groups. The two age groups are differentiated by the mechanical response μ. For the young group the mean value of the shear modulus is μ_y = 0.3, with standard deviation 0.051. For the old group, the mean value of the shear modulus is μ_o = 0.75, and the standard deviation is 0.026. The contours of the growth field ϑ^g show distinct trends between the two age groups, but little variation as the biological parameter [K, k, n] are varied. At day 7, the young group has an average growth greater compared to the older group. The biological parameters mostly influence the transient response. The parameter K controls the saturation of the growth rate in response to elastic stretch, leading to either underdamped or overdamped curves for the three points of interest: apex (red), middle (blue) and periphery (black). The parameter k controls the speed of the adaptation. The parameter n influences the nonlinearity of the growth rate function, leading to underdamped or overdamped responses.