Motivated by recent experiments on the hovering of passive bodies, we demonstrate how a simple shape-changing body can hover or ascend in an oscillating background flow. We study this ratcheting effect through numerical simulations of the two-dimensional Navier–Stokes equations at intermediate Reynolds number. This effect could describe a viable means of locomotion or transport in such environm...

We examine the accelerating ‘obesity epidemic’ in the US from the perspective of generalized language-of-thought arguments relating a cognitive hypothalamic-pituitary-adrenal axis to an embedding context of structured psychosocial stress. From a Rate Distortion perspective, the obesity epidemic is an image of ratcheting social pathology – indexed by massive, policydriven, deurbanization and dei...

Brownian transport of self-propelled overdamped microswimmers (like Janus particles) in a two-dimensional periodically compartmentalized channel is numerically investigated for different compartment geometries, boundary collisional dynamics, and particle rotational diffusion. The resulting time-correlated active Brownian motion is subject to rectification in the presence of spatial asymmetry. W...