Related papers: Cytoplasmic streaming in C. elegans: forces that d…
The enteric bacterium Proteus mirabilis, which is a pathogen that forms biofilms in vivo, can swarm over hard surfaces and form concentric ring patterns in colonies. Colony formation involves two distinct cell types: swarmer cells that…
Background Despite its status as a model organism, the development of Caenorhabditis elegans is not necessarily archetypical for nematodes. The phylum Nematoda is divided into the Chromadorea (indcludes C. elegans) and the Enoplea. Compared…
This paper describes the five development stages of the rope worm, which could be human parasite. Rope worms have been discovered as a result of cleansing enemas. Thousands or people have passed the rope worms from all over the World. Adult…
Conjugation accelerates bacterial evolution by enabling bacteria to acquire genes horizontally from their neighbors. Plasmid donors must physically encounter and connect with recipients to allow plasmid transfer, and different environments…
Galaxies evolve under the influence of gas flows between their interstellar medium and their surrounding gaseous halos known as the circumgalactic medium (CGM). The CGM is a major reservoir of galactic baryons and metals, and plays a key…
We quantitatively study the transport of E. coli near the walls of confined microfluidic channels, and in more detail along the edges formed by the interception of two perpendicular walls. Our experiments establish the connection between…
Galactic outflows play a major role in the evolution of galaxies and the intergalactic medium (IGM). The energy deposited into the interstellar medium by supernovae and active galactic nuclei can accelerate the gas past the escape velocity,…
It has long been believed that swimming eukaryotes feel solid boundaries through direct ciliary contact. Specifically, based on observations of behavior of green alga Chlamydomonas reinhardtii it has been reported that it is their "flagella…
Circular milling, a stunning manifestation of collective motion, is found across the natural world, from fish shoals to army ants. It has been observed recently that the plant-animal worm $Symsagittifera~roscoffensis$ exhibits circular…
The circumgalactic medium (CGM) is fed by galaxy outflows and accretion of intergalactic gas, but its mass, heavy element enrichment, and relation to galaxy properties are poorly constrained by observations. In a survey of the outskirts of…
Patterns in biology can be considered as predetermined, or arising from a self-organizing instability. Variability in the pattern can thus be interpreted as a trace of an instability, growing out from noise. Variability can thus hint toward…
Actin flow in the cortical cytoskeleton underneath the cell membrane generates mechanical stresses that shape the cell surface. We study this mechanism using a hydrodynamic model of a compressible active gel polymerizing at the membrane and…
Swimming cells and microorganisms are a critical component of many biological processes. In order to better interpret experimental studies of low Reynolds number swimming, we combine experimental and numerical methods to perform an analysis…
Traditionally, the primary mode for locomotion of amoeboid cells was thought to be crawling on a substrate. Recently, it has been experimentally shown that \textit{Dictostelium} amoeba and neutrophils can also swim in a directed fashion.…
Spectacular collective phenomena such as jamming, turbulence, wetting, and waves emerge when living cells migrate in groups.
Acoustical and optical vortices have attracted large interest due to their ability in capturing and manipulating particles with the use of the radiation pressure. Here we show that acoustical vortices can also induce axial vortical flow…
We propose an alternative mechanism for intracellular cargo transport which results from motor induced longitudinal fluctuations of cytoskeletal microtubules (MT). The longitudinal fluctuations combined with transient cargo binding to the…
In tissues as diverse as amphibian skin and the human airway, the cilia that propel fluid are grouped in sparsely distributed multiciliated cells (MCCs). We investigate fluid transport in this "mosaic" architecture, with emphasis on the…
Rheotaxis is a well-known phenomenon among microbial organisms and artificial active colloids, wherein the swimmers respond to an imposed flow. We report the first experimental evidence of upstream rheotaxis by spherical active droplets. It…
The need for organisms to regulate their volume and osmolarity when surrounded by freshwater is a basic physical challenge for many bacteria, protists and algae. Taking inspiration from the contractile vacuole complex found in many…