Ciliary chemosensitivity is enhanced by cilium geometry and motility
(2021)
Complex A-site magnetism in quadruple perovskite materials
ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES 77 (2021) C151-C151
Coupling Turing stripes to active flows
Soft Matter (2021)
Abstract:
We numerically solve the active nematohydrodynamic equations of motion, coupled to a Turing reaction-diffusion model, to study the effect of active nematic flow on the stripe patterns resulting from a Turing instability. If the activity is uniform across the system, the Turing patterns dissociate when the flux from active advection balances that from the reaction-diffusion process. If the activity is coupled to the concentration of Turing morphogens, and neighbouring stripes have equal and opposite activity, the system self organises into a pattern of shearing flows, with stripes tending to fracture and slip sideways to join their neighbours. We discuss the role of active instabilities in controlling the crossover between these limits, Our results are of relevance to mechanochemical coupling in biological systems.
Sustained Enzymatic Activity and Flow in Crowded Protein Droplets
(2021)
The role of dimensionality and geometry in quench-induced nonequilibrium forces
J. Phys.: Condens. Matter 33 (2021) 375102 (13pp)
Abstract:
We present an analytical formalism, supported by numerical simulations, for studying forces
that act on curved walls following temperature quenches of the surrounding ideal Brownian
fluid. We show that, for curved surfaces, the post-quench forces initially evolve rapidly to an
extremal value, whereafter they approach their steady state value algebraically in time. In
contrast to the previously-studied case of flat boundaries (lines or planes), the algebraic decay
for curved geometries depends on the dimension of the system. Specifically, steady-state
values of the force are approached in time as t
−d/2 in d-dimensional spherical (curved)
geometries. For systems consisting of concentric circles or spheres, the exponent does not
change for the force on the outer circle or sphere. However, the force exerted on the inner
circles or sphere experiences an overshoot and, as a result, does not evolve to the steady state
in a simple algebraic manner. The extremal value of the force also depends on the dimension
of the system, and originates from curved boundaries and the fact that particles inside a sphere
or circle are locally more confined, and diffuse less freely than particles outside the circle or
sphere.
that act on curved walls following temperature quenches of the surrounding ideal Brownian
fluid. We show that, for curved surfaces, the post-quench forces initially evolve rapidly to an
extremal value, whereafter they approach their steady state value algebraically in time. In
contrast to the previously-studied case of flat boundaries (lines or planes), the algebraic decay
for curved geometries depends on the dimension of the system. Specifically, steady-state
values of the force are approached in time as t
−d/2 in d-dimensional spherical (curved)
geometries. For systems consisting of concentric circles or spheres, the exponent does not
change for the force on the outer circle or sphere. However, the force exerted on the inner
circles or sphere experiences an overshoot and, as a result, does not evolve to the steady state
in a simple algebraic manner. The extremal value of the force also depends on the dimension
of the system, and originates from curved boundaries and the fact that particles inside a sphere
or circle are locally more confined, and diffuse less freely than particles outside the circle or
sphere.