Anomalous diffusion is a diffusion process with a non-linear relationship to time, in contrast to a typical diffusion process, in which the mean squared displacement (MSD), σr2, of a particle is a linear function of time. Physically, the MSD can be considered the amount of space the particle has "explored" in the system.
Diffusion is often described by a power law, σr2 ~ Dtα, where D is the diffusion coefficient and t is the elapsed time. In a typical diffusion process, α = 1. If α > 1, the phenomenon is called super-diffusion. Super-diffusion can be the result of active cellular transport processes. If α < 1, the particle undergoes sub-diffusion.
Recently, the role of Anomalous diffusion has received attention within the literature to describe many physical scenarios, most prominently within crowded systems, for example protein diffusion within cells, or diffusion through porous media.
Sub-diffusion has been proposed as a measure of macromolecular crowding in the cytoplasm.
Read more about Anomalous Diffusion: Types of Anomalous Diffusion
Famous quotes containing the word anomalous:
“Before the land rose out of the ocean, and became dry land, chaos reigned; and between high and low water mark, where she is partially disrobed and rising, a sort of chaos reigns still, which only anomalous creatures can inhabit.”
—Henry David Thoreau (1817–1862)