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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…)

Book explains astrobiology for a general audience

By Guest PostJanuary 13, 2014Scienceacid, acknowledge the wonder, alkaline, astrobiology, d h lawrence, david catling, enceladus, europa, extraterrestrial microbes, geology, icy particles, mars, moon of jupiter, moon of saturn, origin of life, oxford university press, ph, planetary science, plume, political realms, seafloor, solar system, southwest native americans, united states

In the late 1990s, the University of Washington created what was arguably the world’s first graduate program in astrobiology, aimed at preparing scientists to hunt for life away from Earth. In 2001, David Catling became one of the first people brought to the UW specifically to teach astrobiology.

Catling, a UW professor of Earth and space sciences, is the author of Astrobiology: A Very Short Introduction, the 370^th offering in the Oxford University Press series of “very short introduction” books by experts in various fields. Catling was commissioned by editors to write the book, which was published in the United States on Jan. 1. Following are his answers to some questions about the book and astrobiology. (more…)

A Micro-Muscular Break Through

By Guest PostJanuary 13, 2014Scienceartificial muscles, berkeley lab, break through, carbon nanotubes, chromium, chun cheng, electronics industry, electrostatics, energy-efficient, helix, joonki suh, junqiao wu, kai liu, micro explosion, micro muscular, micro systems, milliseconds, motion, optical devices, pantheon of superstars, piezoelectrics, vanadium dioxide

Berkeley Lab Researchers Make a Powerful New Microscale Torsional Muscle/Motor from Vanadium Dioxide

Vanadium dioxide is poised to join the pantheon of superstars in the materials world. Already prized for its extraordinary ability to change size, shape and physical identity, vanadium dioxide can now add muscle power to its attributes. A team of researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) has demonstrated a micro-sized robotic torsional muscle/motor made from vanadium dioxide that for its size is a thousand times more powerful than a human muscle, able to catapult objects 50 times heavier than itself over a distance five times its length within 60 milliseconds – faster than the blink of an eye. (more…)

Intimate yeast: Mating and meiosis

By Guest PostJanuary 13, 2014Scienceexotic sex, fused program, intimate yeast, mating, meiosis

Mating and meiosis – the specialized cell division that reduces the number of chromosomes in a cell – are related, but in most yeasts they are regulated separately. Not so in Candida lusitaniae, where the two programs work in unison, according to a new study in Nature. Comparison with other species suggests that this fusion may support C. lusitaniae’s “haploid lifestyle” of maintaining only one set of chromosomes in each cell. (more…)

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