It is noted that there is also some potential uncertainty in the diffusion coefficients which shall be investigated further below.
Once the ROIs were created, the PICo algorithm was run without any angular threshold to account for the high curvature of ML and with a relatively low FA threshold, 0.1, to allow the tracts to reach the extremities of the OR ending in grey matter regions while avoiding a too high number of spurious tracts associated with voxels exhibiting high uncertainty in the diffusion directions.
The uncertainties affecting the diffusion coefficient D have a large scatter in the first life years of an RC structure, while after that time the overall uncertainty of the diffusion coefficient results reduced (Saassouh and Lounis 2012).
Because the diffusion length depends on the square root of the diffusion coefficient, the uncertainties on the diffusion coefficient do not noticeably influence the results.
Recent studies have identified uncertainties in fuel diffusion coefficients as a source of significant uncertainty in combustion modeling.
For example, we see that the uncertainty over the diffusion parameter d is much smaller than the uncertainty over the other parameters.
In the primate retina, the dendritic arbors of DA cells have diameters of ∼400 µm near the fovea and ∼600 µm in the periphery, whereas the axon-like arbors encompass a diameter of at least 6 mm, the exact value being difficult to ascertain due to uncertainty in the extent of diffusion of the injected label [24].
This approach enabled us to estimate ancestral spatial locations throughout the phylogenetic history while accounting for uncertainty in the phylogenetic and diffusion process (17 ).
AF participated in the diffusion experiments.
Too many geographic locations in a dataset forces the diffusion process to average over a very high state space, which can be difficult, and may lead to uncertainties in the model (P. Lemey, personal communication).
