sperm selection techniques have became an important tool to improve sub fertile ejaculates. the main aim of this study was to assess the dynamics of motile sperm subpopulations of ejaculates from subfertile stallions subjected to density gradient centrifugation (dgc) involving a double layer colloid [dgc2], before and after storage for 24 and 48 hours. ejaculates from eight stallions with ferti...

Twitching motility is an important migration mechanism for the Gram-negative bacterium Pseudomonas aeruginosa. In the commonly used subsurface twitching assay, the sub-population of P. aeruginosa with active twitching motility is difficult to harvest for high-throughput studies. Here we describe the development of a novel method that allows efficient isolation of bacterial sub-populations condu...

Artificially designed self-propelled objects can allow studying active matter phenomena with great detail that is not possible in natural, e.g. biological systems. Here, we show experimental results on helical shaped, magnetically actuated, reciprocal swimmers, where the degree of randomness sequence plays an important role determining their effective motility. for first time at high activity l...

We explore a generic mechanism whereby a droplet of active matter acquires motility by the spontaneous breakdown of a discrete symmetry. The model we study offers a simple representation of a "cell extract" comprising, e.g., a droplet of actomyosin solution. (Such extracts are used experimentally to model the cytoskeleton). Actomyosin is an active gel whose polarity describes the mean sense of ...