Two separate research groups are reporting groundbreaking measurements of the fluid flow that surrounds freely swimming microorganisms.
Researchers have mapped the flow field around a swimming Volvox carteri microbe by tracking the movements of tiny tracer particles. The spherical Volvox is swimming towards the top of the image. Streamlines appear as red curves, and the color map corresponds to the fluid velocity.
Credit: K. Drescher, R. E. Goldstein, N. Michel, M. Polin, and I. Tuval, University of Cambridge
Experiments involving two common types of microbes reveal the ways that one creature's motion can affect its neighbors, which in turn can lead to collective motions of microorganism swarms. In addition, the research is helping to clarify how the motions of microscopic swimmers produces large scale stirring that distributes nutrients, oxygen and chemicals in lakes and oceans. A pair of papers describing the experiments will appear in the October 11 issue of the APS journal Physical Review Letters.
In order to observe the flow that microorganisms produce, researchers at the University of Cambridge tracked the motion of tiny tracer beads suspended in the fluid surrounding the tiny swimmers. They used the technique to study the fluid around two very different types of creatures: a small, blue-green form of algae called Chlamydomonas reinhardtii that swims by paddling with a pair of whip-like flagella, and the larger, spherical alga Volvox carterii that propels itself with thousands of flagella covering its surface. The tracer beads showed that the two types of organisms generate distinctly different flow patterns, both of which are much more complex than previously assumed. In a related study performed at Haverford College in Pennsylvania, researchers used a high speed camera to track the flow of tracer particles around Chlamydomonas in a thin, two-dimension film of fluid over the course of a single stroke of its flagella.
The studies should help scientists develop new models to predict the fluid motions associated with aquatic microorganisms. The models will provide clearer pictures of the ways microbes mix bodies of water, and potentially offer insights into the role plankton plays in the carbon cycle as it stirs the world's oceans. David Saintillan (University of Illinois at Urbana Champagne) gives an overview of the microorganism swimming research in a Viewpoint article in the October 11 edition of APS Physics (physics.aps.org). Advance copies of the Physical Review Letters articles and the related Physics Viewpoint are available to journalists on request.
Also in Physics: LHC takes the reins of high energy particle physics
The Large Hadron Collider (LHC) has just begun collecting data from colliding bunches of protons, and is still running at only half its design limits, but after a few months of operation it has already surpassed some of the major accomplishments of its predecessor – the Fermilab particle accelerator laboratory in Batavia Illinois. The LHC's first achievements put tighter limits on extensions of the highly successful Standard Model of physics, which describes the currently known subatomic particles. A Synopsis describing the landmark publication of the LHC's early results will appear in the October 11 edition of Physics. Advance copies of the Physical Review Letters article describing the research, and the associated Physics Synopsis, are available on request.
Physics (http://physics.aps.org) is a production of the American Physical Society that provides expert written commentaries and highlights of papers appearing in the Society's journals.
MEMS chips get metatlenses
21.02.2018 | American Institute of Physics
International team publishes roadmap to enhance radioresistance for space colonization
21.02.2018 | Biogerontology Research Foundation
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
21.02.2018 | Life Sciences
21.02.2018 | Life Sciences
21.02.2018 | Materials Sciences