title: Reconciling transport models across scales: The role of volume exclusion.
abstract: Diffusive transport is a universal phenomenon, throughout both biological and physical sciences, and models of diffusion are routinely used to interrogate diffusion-driven processes. However, most models neglect to take into account the role of volume exclusion, which can significantly alter diffusive transport, particularly within biological systems where the diffusing particles might occupy a significant fraction of the available space. In this work we use a random walk approach to provide a means to reconcile models that incorporate crowding effects on different spatial scales. Our work demonstrates that coarse-grained models incorporating simplified descriptions of excluded volume can be used in many circumstances, but that care must be taken in pushing the coarse-graining process too far.
authors.affiliation: Mathematical Institute, University of Oxford, Woodstock Road, Oxford OX2 6GG, United Kingdom.
authors.forename: P R
authors.initials: PR
authors.lastname: Taylor
authors.affiliation: Department of Mathematical Sciences, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom.
authors.forename: C A
authors.initials: CA
authors.lastname: Yates
authors.affiliation: Mathematical Sciences, Queensland University of Technology, G.P.O. Box 2434, Brisbane 4001, Australia.
authors.forename: M J
authors.initials: MJ
authors.lastname: Simpson
authors.affiliation: Mathematical Institute, University of Oxford, Woodstock Road, Oxford OX2 6GG, United Kingdom.
authors.forename: R E
authors.initials: RE
authors.lastname: Baker
mesh_terms: D004058:Diffusion; D008962:Models, Theoretical; D013269:Stochastic Processes