(Press-News.org) Nematodes, microscopic worms, are making engineers look twice at their ability to exhibit the "Cheerios effect" when they move in a collective motion.
These parasites will actually stick together like Cheerios swimming in milk in a cereal bowl after a chance encounter "due to capillary force." This observation has made Virginia Tech engineers speculate about the possible impacts on the study of biolocomotion.
Their work appears in the journal, Soft Matter, a publication of the Royal Society of Chemistry, the week of Feb. 7. Soft Matter is the premier journal in the ongoing multidisciplinary work between physics, material science, and biology. http://www.rsc.org/Publishing/Journals/sm/News/impactfactor_2009.asp
Two Harvard physicists first defined the Cheerios effect. In 2005, Dominic Vella and Lakshminarayanan Mahadevan wrote an article on this activity, defined by scientists as relating to fluid mechanics, in the Journal of Physics. They cited its usefulness in the study of self-assembly of small structures. Self-assembly is used in the science of nanotechnology.
Dominic Vella who now teaches at the University of Oxford, United Kingdom, collaborated with Sunghwan "Sunny" Jung, an assistant professor of engineering science and mechanics at Virginia Tech, and his student, Sean Gart, of Salem, Va., a senior in engineering science and mechanics, and authored the new paper, "The collective motion of nematodes in a thin liquid layer."
Their work highlights the behaviors of the nematode Panagrellus redivivus, a creature that feeds on bacteria, in a watery liquid layer that is thinner than a human hair. In this environment the nematodes crawl by creating waves that travel backwards down their body, and the force pushes them forward.
"The inspiration for the project came when we observed the nematodes crawling up the side of their container and sticking together. We knew part of the reason for this behavior was due to the capillary force, the same force that causes Cheerios to stick together in a cereal bowl, but we wanted to see whether or not the nematodes moved faster or more efficiently while stuck together," Jung and Gart explained.
"Thin water refers to the air/liquid interface. Like Cheerios in milk, the nematodes are aggregating on top of the air surface, not on the bulk or on the bottom," Jung said.
Gart has been working in Virginia Tech's Biologically Inspired Fluids Laboratory directed by Jung since last summer. Gart found that the nematodes did not crawl faster or more efficiently while stuck together.
"This is an interesting behavior that has not been studied very widely in the biolocomotion field," Jung said. "The result implies that nematodes gain neither a mechanical advantage nor disadvantage by being grouped together. The capillary forces merely keep them together after a chance encounter. This result also extends a better understanding of capillary effects in colloidal particles in engineering systems such as pickering emulsions. These emulsions are stabilized by solid particles. An example would be homogenized milk."
INFORMATION:
When worms stick together and swim on thin water, what happens and why does it matter?
2011-02-09
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
In February journal, UC and industry researchers predict future of electronic devices
2011-02-09
VIDEO:
University of Cincinnati researcher Jason Heikenfeld is part of an internationally prestigious team that specializes in research and development of e-devices. Based on his work, he provides a top ten...
Click here for more information.
The just-released February issue of the Journal of the Society for Information Display contains the first-ever critical review of current and future prospects for electronic paper functions – in other words reviewing and critiquing ...
New data obtained on liposomes employed in drug encapsulation and gene therapies
2011-02-09
This release is available in Spanish.
University of Granada scientists and the Spanish Higher Institute for Scientific Research (CSIC) have made significant progress in understanding lipid membranes, which are extensively employed in the development of cosmetic and drug products, and which have potential application in the field of nanotechnology.
Phospholipid vesicles (liposomes) are colloidal systems that arise considerable interest from the pharmaceutical, cosmetic and food industry, since they are biocompatible in protein, nucleic acid, drug, etc encapsulation. ...
Lower mental health co-pays do not help seniors seek care
2011-02-09
PROVIDENCE, R.I. [Brown University] — Despite the intent of recent mental health "parity" legislation, including the Affordable Care Act, even steep reductions in co-pays for outpatient mental health care will not motivate more seniors in managed care plans to seek that care, according to a new study by Brown University researchers.
Parity measures, included in laws passed in 2008 and 2010, end an insurance industry practice of charging higher co-pays for mental health care than for other care. While the laws will allow many seniors who undergo treatment to save money, ...
The great tonsil dilemma
2011-02-09
ANN ARBOR, Mich. — Without fanfare, hundreds of thousands of children surrender their tonsils to a surgeon's scalpel each year, usually to alleviate recurring infections and obstructive sleep problems. Most of the time, the snipped tonsils are sent to a pathologist, who looks for evidence of more serious medical problems, like unsuspected cancer.
But this common practice may not be cost-effective because those additional examinations rarely lead to the discovery of hidden disease, a new University of Michigan Heath System analysis shows.
The approximately $35 million ...
CeBIT 2011: Electronic fitness trainer
2011-02-09
This release is available in German.
Eating a healthier diet, getting more exercise and doing more sports – lots of people recommit themselves to these goals over and over. But one's baser instincts are often stronger and invincible. On the couch in the evening, you take stock of the day only to admit that you have failed to rally once again. And yet, physical fitness is now considered a remedy for many illnesses. Particularly for older people, daily exercise is important – not only during rehabilitation following major surgery but also for one's general sense of physical ...
The success of male bustards is measured by their 'beards'
2011-02-09
Up until now it was unknown whether males of the great bustard (Otis tarda), an emblematic bird in Spain and endangered at a global level, transmit information on their weight, size, and age through their plumage. For the first time a study shows that the 'beards' and the design of the neck are "reliable" indicators of the weight and age of their bearers, and are used to both avoid fights with competitors and to attract females.
"The heaviest males (best physical condition) make it known to other males through the length and number of 'beards', and thereby avoid bloody ...
Fingerprint makes chips counterfeit-proof
2011-02-09
This release is available in German.
Product piracy long ago ceased to be limited exclusively to the consumer goods sector. Industry, too, is increasingly having to combat this problem. Cheap fakes cost business dear: The German mechanical and plant engineering sector alone lost 6.4 billion euros of revenue in 2010, according to a survey by the German Engineering Federation (VDMA). Sales losses aside, low-quality counterfeits can also damage a company's brand image. Worse, they can even put people's lives at risk if they are used in areas where safety is paramount, ...
The most genes in an animal? Tiny crustacean holds the record
2011-02-09
Scientists have discovered that the animal with the most genes--about 31,000--is the near-microscopic freshwater crustacean Daphnia pulex, or water flea.
By comparison, humans have about 23,000 genes. Daphnia is the first crustacean to have its genome sequenced.
The water flea's genome is described in a Science paper published this week by members of the Daphnia Genomics Consortium, an international network of scientists led by the Center for Genomics and Bioinformatics (CGB) at Indiana University (IU) Bloomington and the U.S. Department of Energy's Joint Genome Institute.
"Daphnia's ...
Wolverines threatened by climate change, earlier springs
2011-02-09
The aggressive wolverine may not be powerful enough to survive climate change in the contiguous United States, new research concludes.
Wolverine habitat in the northwestern United States is likely to warm dramatically if society continues to emit large amounts of greenhouse gases, according to new computer model simulations carried out at the National Center for Atmospheric Research (NCAR) in Boulder, Colo.
"The researchers have combined regional-scale climate projections with knowledge of a single species and its unique habitat to examine its vulnerability to a changing ...
Experimental approach may improve healing of diabetic wounds and bed sores
2011-02-09
MAYWOOD, Ill. -- Loyola University Health System researchers are reporting on a promising new approach to treating diabetic wounds, bed sores, chronic ulcers and other slow-to-heal wounds.
It may be possible to speed healing by suppressing certain immune system cells, researchers wrote in the February, 2011, issue of the journal Expert Review of Dermatology.
The cells are called neutrophils and natural killer T (NKT) cells. These white blood cells act to kill bacteria and other germs that can infect wounds. NKT cells also recruit other white blood cells to the site ...