TY - JOUR

T1 - Exits in order

T2 - how crowding affects particle lifetimes

AU - Penington, Catherine J.

AU - Baker, Ruth E.

AU - Simpson, Matthew J.

PY - 2016/6/28

Y1 - 2016/6/28

N2 - Diffusive processes are often represented using stochastic random walk frameworks. The amount of time taken for an individual in a random walk to intersect with an absorbing boundary is a fundamental property that is often referred to as the particle lifetime, or the first passage time. The mean lifetime of particles in a random walk model of diffusion is related to the amount of time required for the diffusive process to reach a steady state. Mathematical analysis describing the mean lifetime of particles in a standard model of diffusion without crowding is well known. However, the lifetime of agents in a random walk with crowding has received much less attention. Since many applications of diffusion in biology and biophysics include crowding effects, here we study a discrete model of diffusion that incorporates crowding. Using simulations, we show that crowding has a dramatic effect on agent lifetimes, and we derive an approximate expression for the mean agent lifetime that includes crowding effects. Our expression matches simulation results very well, and highlights the importance of crowding effects that are sometimes overlooked.

AB - Diffusive processes are often represented using stochastic random walk frameworks. The amount of time taken for an individual in a random walk to intersect with an absorbing boundary is a fundamental property that is often referred to as the particle lifetime, or the first passage time. The mean lifetime of particles in a random walk model of diffusion is related to the amount of time required for the diffusive process to reach a steady state. Mathematical analysis describing the mean lifetime of particles in a standard model of diffusion without crowding is well known. However, the lifetime of agents in a random walk with crowding has received much less attention. Since many applications of diffusion in biology and biophysics include crowding effects, here we study a discrete model of diffusion that incorporates crowding. Using simulations, we show that crowding has a dramatic effect on agent lifetimes, and we derive an approximate expression for the mean agent lifetime that includes crowding effects. Our expression matches simulation results very well, and highlights the importance of crowding effects that are sometimes overlooked.

UR - http://www.scopus.com/inward/record.url?scp=84977139775&partnerID=8YFLogxK

UR - http://purl.org/au-research/grants/arc/DP140100249

UR - http://purl.org/au-research/grants/arc/FT130100148

U2 - 10.1063/1.4953913

DO - 10.1063/1.4953913

M3 - Article

C2 - 27369497

SN - 0021-9606

VL - 144

SP - 1

EP - 7

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

IS - 24

M1 - 244107

ER -