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Cilia use different motors for different tasks

By Guest PostJanuary 17, 2014Scienceanita zimmerman, brown biologist, brown university, cilia, hair like fibers, ilyong jung, james valles, liquid, locomotion, motor behaviors, oral groove, plain water, single celled paramecia, tiny oars, viscosity, viscosity of water

Cilia — short, hair-like fibers — are widely present in nature. Single-celled paramecia use one set of cilia for locomotion and another set to sweep nutrients into their oral grooves. Researchers at Brown have discovered that those two cilia sets operate at different speeds when the viscosity of the environment changes. That suggests different molecular motors driving them, which could help explain how cilia have come to be used for so many different tasks in nature.

PROVIDENCE, R.I. [Brown University] — Cilia are one of nature’s great multipurpose tools. The tiny, hair-like fibers protrude from cell membranes and perform all kinds of tasks in all kinds of creatures, from helping clear debris from human lungs to enabling single-celled organisms to swim. Now, physicists from Brown University have discovered something that could help scientists understand how cilia have been adapted for so many varied tasks. (more…)

‘Standing on a comet’: Rosetta mission will contribute to space weather research

By Guest PostJanuary 16, 2014Scienceandre bieler, archeological artifacts, carbon dioxide, churyumov gerasimenko, comet 67p, comet bound spacecraft, electric grid, electrified particles, european space agency, evolution, ionosphere, kenneth hansen, michael combi, model, on a comet, orbit of neptune, origin, planets, rosetta, rosetta mission, rosetta mission lander, rosetta orbiter, satellites, solar system, space weather research, standing, sun, tamas gombosi, the philae lander, university of michigan, valeriy tenishev

ANN ARBOR — A comet-bound spacecraft that’s been in sleep mode for more than two years is scheduled to wake up on the morning of Jan. 20—beginning the home stretch of its decade-long journey to a mile-wide ball of rock, dust and ice.

If all goes as planned, Rosetta—a European Space Agency-led mission that involves University of Michigan engineers and scientists—will be the first craft to actually land on a comet as well as track it for an extended period of time. (more…)

Discovery spotlights key role of mystery RNA modification in cells

By Guest PostJanuary 16, 2014Sciencecell differentiation, cells, chuan he, demethylation, deoxyribonucleic acid, diabetes, discovery, DNA, exact function, healthy cells, infertility, key role, m6a, messenger ribonucleic acid, methyl, methylation, mrna, mrna in question, mystery, n6 methyladenosine, neurobiology, obesity, organic compounds, parameter, peking university, proteins, regulating mrna lifetime, rna modification, san diego, sequence, university of california, university of chicago, xiao wang, ythdf2

Researchers had known for several decades that a certain chemical modification exists on messenger ribonucleic acid (mRNA), which is essential to the flow of genetic information. But only recently did experiments at the University of Chicago show that one major function of this modification governs the longevity and decay of RNA, a process critical to the development of healthy cells.

The chemical modification on mRNA in question is called N⁶-methyladenosine (m⁶A). A recent study by UChicago scientists reveals how the m⁶A modification on mRNA could affect the half-life of mRNA that in turn regulates cellular protein quantities. That discovery could provide fundamental insights into healthy functioning and disorders such as obesity, diabetes and infertility. (more…)

Tiny acts of microbe justice help reveal how nature fights freeloaders

By Guest PostJanuary 16, 2014Sciencebacteria vibrio cholerae, bioremediation, biosphere, bonnie bassler, carey nadell, fights freeloaders, history, howard stone, industrial cleanup, infection, knut drescher, life on earth, mechanism, microbe, nitrogen containing molecules, princeton university, public goods dilemma, recycle, tiny acts, treating a disease, v cholera

The idea of everyone in a community pitching in is so universal that even bacteria have a system to prevent the layabouts of their kind from enjoying the fruit of others’ hard work, Princeton University researchers have discovered.

Groups of the bacteria Vibrio cholerae deny loafers their unjust desserts by keeping the food generated by the community’s productive members away from V. cholerae that attempt to live on others’ leftover nutrients, the researchers report in the journal Current Biology. The researchers found that individual bacteria produce a thick coating around themselves to prevent nutrients from drifting over to the undeserving. Alternatively, the natural flow of fluids over the surface of bacterial communities can wash away excess food before the freeloaders can indulge. (more…)

Exoplanet study finds ‘super-Earths’ likely have oceans and continents

By Guest PostJanuary 15, 2014Scienceastronomy, continents, dorian abbot, earth, exoplanet study, Galaxy, geological timescale, geophysicist, geophysics, habitable zone, interior, massive terrestrial planets, Milky Way, new model, nicolas b cowan, oceans, proportional to gravity, solar system, super earths, thermostat, university of chicago, water, water cycle

Massive terrestrial planets, called “super-Earths,” are known to be common in Earth’s galaxy, the Milky Way. Now a Northwestern University astrophysicist and a University of Chicago geophysicist report the odds of these planets having an Earth-like climate are much greater than previously thought.

Nicolas B. Cowan and Dorian Abbot’s new model challenges the conventional wisdom, which says super-Earths actually would be very unlike Earth—each would be a waterworld, with its surface completely covered in water. They conclude that most tectonically active super-Earths—regardless of mass—store most of their water in the mantle and will have both oceans and exposed continents, enabling a stable climate such as Earth’s. (more…)

Das Paradox der Fortpflanzung

By Guest PostJanuary 15, 2014Scienceasexuelle invasionen, asexuelle reproduktion, brachionus calyciflorus, claus peter stelzer, cp, das paradox, dauer ei produktion, der fortpflanzung, forschungsinsitut, fwf, limnologie, mondsee, obligater parthenogenese, op, sexuelle reproduktion, zyklischer parthenogenese

Auch wenn asexuelle Reproduktion kurzfristig erfolgreich ist, verspricht sexuelle Reproduktion langfristig mehr Vorteile. Zumindest für Rädertierchen trifft diese Aussage zu, wie ein Wissenschaftler des Forschungsinstituts für Limnologie, Mondsee kürzlich nachweisen konnte.

Das sogenannte „Paradoxon der sexuellen Reproduktion“ ist eines der wichtigsten ungelösten Probleme in der Evolutionsforschung. Es besagt, dass sich die allermeisten mehrzelligen Organismen – trotz hoher Kosten – durch sexuelle Reproduktion vermehren. Beispiele für solche Kosten sind der Aufwand durch die Produktion männlicher Nachkommen, die Kosten der Durchmischung des mütterlichen Genoms beim Sex, oder Kosten, die mit Partnersuche oder Paarung verbunden sind. „Ein besonders interessanter Sonderfall sind deshalb Organismen, die auf natürliche Weise immer wieder asexuelle Vertreter erzeugen“, erklärt Dr. Claus-Peter Stelzer vom Forschungsinsitut für Limnologie, Mondsee. Bei solchen Organismen sollte man erwarten, dass häufig „asexuelle Invasionen“ stattfinden, wobei asexuelle Linien die sexuellen Individuen verdrängen. Der Limnologie hat sich dieses Problem im vom Fonds zur Förderung der wissenschaftlichen Forschung (FWF) finanzierten Projekt „Evolution of asexuality in experimental rotifer populations“ anhand des Rädertiers Brachionus calyciflorus näher angesehen. (more…)

UA Solution for Deadly Shrimp Disease to Become Available Worldwide

By Guest PostJanuary 15, 2014Scienceearly mortality syndrome, livestock industries, screening test, shrimp disease, shrimp producing industry

UA researchers have developed a rapid screening test to detect disease-causing bacteria in commercial shrimp farms

A bacterial disease called early mortality syndrome is killing off the stocks of the world’s three largest shrimp producers: Thailand, China and Vietnam. In some places, production is down by nearly 50 percent from last year. But there is hope. Don Lightner in the School of Animal and Comparative Biomedical Sciences at the UA College of Agriculture and Life Sciences has a solution for detecting the bacteria in the stocks, allowing infected populations to be separated from healthy ones. (more…)

Ladies And Gentlemen, Boot Your Robots!

By Guest PostJanuary 14, 2014Sciencedarpa, emergency response, fukushima nuclear accident, homestead, human engineered environments, humanoids, Japan, march 2011, miami speedway, robosimian, robotics challenge trials

Miami Speedway in Homestead, Fla., was the place to be late last month for an unusual two-day competition: the DARPA Robotics Challenge Trials. But if you went expecting high-octane cars zooming around the track at blazing speed, you might have been disappointed. The 16 robots participating in the challenge moved more like the tortoise than the hare, as they performed such tasks as opening doors or climbing a ladder; tasks aimed to speed the development of robots that could one day perform a number of critical, real-world, emergency-response tasks at natural and human-made disaster sites. (more…)

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