Controlling the swimming behavior of bacteria is crucial, for example, to prevent contamination ducts and catheters. We show that modeled by deformable microswimmers can accumulate in flows through straight microchannels either their center or on previously unknown attractors near channel walls. In wavy we predict a resonance effect semiflexible microswimmers. As result, be deflected controlled...

Extremal six-dimensional black string solutions with some non-trivial momentum distribution along the wave are considered. These solutions were recently shown to contain a singularity at the would-be position of the event horizon. In the black string geometry, all curvature invariants are finite at the horizon. It is shown that if the effects of infalling matter are included, there are curvatur...

A simple model to explain the numerically observed behavior of chaotically varying stripes and square patterns in zero-Prandtl-number convection in Boussinesq fluid is presented. The nonlinear interaction of mutually perpendicular sets of wavy rolls, via higher-order modes, may lead to a competition between the two sets of rolls. The appearance of square patterns is due to a secondary forward b...

This paper reports theoretical and experimental studies on spatio-temporal dynamics in the choruses of male Japanese tree frogs. First, we theoretically model their calling times and positions as a system of coupled mobile oscillators. Numerical simulation of the model as well as calculation of the order parameters show that the spatio-temporal dynamics exhibits bistability between two-cluster ...

Graphical abstract

We report on a newly discovered bifurcation that occurs in dry grains flowing down a chute with a wavy bottom. We find that the bifurcation outwardly resembles the long-know fluid analog of inviscid channel flow over a wavy bottom reported in 1886 by Lord Kelvin, however in detail the two situations differ significantly. We compare three distinct states seen in the granular system: a ‘regular’ ...

BACKGROUND To present an intraoperative acute Descemet's fold formation using swept-source optical coherence tomography (SS-OCT) imaging. CASE REPORT A 67-year-old man complaining of reduced visual acuity in the left eye. A 25-gauge pars plana vitrectomy combined with phacoemulsification cataract surgery was performed to remove the vitreomacular traction. When hydro-sealing was performed, str...

Poor understanding of flow boiling in microgravity has recently emerged as a key obstacle to the development of many types of power generation and life support systems intended for space exploration. This study examines flow boiling CHF in microgravity that was achieved in parabolic flight experiments with FC-72 onboard NASA s KC-135 turbojet. At high heat fluxes, bubbles quickly coalesced into...