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Ancient Pygmy Sea Cow Discovered


ScienceDaily
Fri, 18 Dec 2009 15:00 UTC
Image
© McGill University
A McGill researcher has discovered a near-complete skull of a primitive "dugong" illuminating a virtually unknown period in Madagascar fossil history.
A McGill researcher has discovered a near-complete skull of a primitive dugong dugon illuminating a virtually unknown period in Madagascar fossil history.

The discovery of a Middle Eocene (48.6-37.2 million years ago) sea cow fossil by McGill University professor Karen Samonds has culminated in the naming of a new species. This primitive dugong is among the world's first fully-aquatic sea cows, having evolved from terrestrial herbivores that began exploiting coastal waters. Within this ancient genus, the newly discovered species is unusual as it is the first species known from the southern hemisphere (its closest relatives are from Egypt and India), and is extremely primitive in its skull morphology and dental adaptations. The fossil is a pivotal step in understanding Madagascar's evolutionary history -- as it represents the first fossil mammal ever named from the 80-million-year gap in Madagascar's fossil record.

The research is to be published in the Journal of Vertebrate Paleontology on December 12.
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Looking for the Heartbeat of Cellular Networks


ScienceDaily
Fri, 18 Dec 2009 06:00 UTC
Our cells' molecules form an intricate network of interactions. Today's techniques, however, can only be used to measure individual molecular reactions outside the cells. Since molecular concentrations are much higher in cells than in the laboratory, scientists suspect that the kinetics of molecular reactions in living cells differ substantially from external probes.

"We expected the cellular reaction speed to be higher," confirms LMU biophysicist Professor Dieter Braun. "However, our novel optical approach showed that -- depending on the length of the strands -- the coupling of DNA-strands inside living cells can be both faster and slower than outside." Data yielded from living cells are highly valuable for the development of models to understand the complex interactions as well as pathological processes in biological cells. Braun and his team now plan to probe a variety of molecular reactions in living cells, visualizing the heartbeat of cellular networks.

In their work, the scientists investigated the hybridization -- the coupling and de-coupling -- of two DNA-strands, which they introduced into living cells. To determine the reaction time constant they used an infrared laser to induce temperature oscillations of different frequencies in the cell and measured the concentration of the reaction partners, namely of coupled and de-coupled DNA. At low frequencies, these concentrations followed the temperature oscillations, whereas at higher frequencies they experienced a phase delay and oscillated with diminished amplitude. Both delay time and amplitude decrease, were evaluated to obtain the reaction time constant.
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Scientists Use Light to Map Neurons' Effects on One Another


ScienceDaily
Fri, 18 Dec 2009 15:00 UTC
Scientists at Harvard University have used light and genetic trickery to trace out neurons' ability to excite or inhibit one another, literally shedding new light on the question of how neurons interact with one another in live animals.

The work is described in the current issue of the journal Nature Methods. It builds upon scientists' understanding of the neural circuitry of the nematode worm Caenorhabditis elegans, frequently used as a model in biological research. While the detailed physical structure of C. elegans' scant 302 neurons is well documented, the new research helps measure how neurons in this organism affect each others' activity, and could ultimately help researchers map out in detail how neural impulses flow throughout the organism.

"This approach gives us a powerful new tool for analyzing small neural circuits, and directly measuring how neurons talk to each other," says Sharad Ramanathan, an assistant professor of molecular and cellular biology and of applied physics at Harvard. "While we've only mapped out the interplay of four neurons, it's the first time scientists have determined the ability of multiple neurons in a circuit to excite or inhibit their neighbors."
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Bizarro Earth

The Art of Asteroid Deflection

Cynthia Mills
Discovery News
Thu, 17 Dec 2009 09:53 UTC
There's really nothing to worry about. These guys have got it handled. All they need is to convince Congress they need $500 million and the international community to agree on which direction to go to push a hurtling asteroid off its path of fiery Earth annihilation.

These guys are a loose association of scientists, including a retired astronaut and many work for NASA's Jet Propulsion Laboratory. Together they study the risk of an Earth impact from an asteroid big enough to do damage, you know, like the one that caused all the dinosaurs to become extinct.

Only they don't call it an "asteroid" -- instead they use a more general term: Near Earth Object (NEO). They concentrate on anything bigger than 140 meters across (but mostly worry about the ones at least a mile across) and traveling on a trajectory that brings them within 4.6 million miles of the earth. They're watching, calculating and ready to do something.
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Bizarro Earth

Saving Earth From an Asteroid Will Take Bureaucrats, Not Heroes

Alexis Madrigal
Wired
Wed, 16 Dec 2009 18:29 UTC
gravity_tug
© NASA
A gravity tug
San Francisco - In the movie version of stopping an asteroid from hitting Earth popularized by Armageddon, a few brave Americans quickly head out to the near-Earth object and blow it up.

The reality will be far less dramatic, former astronaut Rusty Schweickart told scientists at the American Geophysical Union meeting here Wednesday. Asteroid-deflection efforts will have to start years before a prospective impact and will have to be essentially international.
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Telescope

Fog Discovered on Saturn's Largest Moon, Titan


Science Daily
Fri, 18 Dec 2009 15:42 UTC
Image
© Mike Brown/Caltech
Fingers of fog can be seen moving across the south pole of Titan in this image constructed by Mike Brown and his colleagues using data from the Cassini spacecraft. The fog shows regions where pools of liquid methane sitting on the surface of Titan are evaporating into the atmosphere. After a long summer of frequent clouds and rain at the south pole, it appears in this late summer image that evaporating liquid methane covers large areas of the pole.
Saturn's largest moon, Titan, looks to be the only place in the solar system -- aside from our home planet, Earth -- with copious quantities of liquid (largely, liquid methane and ethane) sitting on its surface. According to planetary astronomer Mike Brown of the California Institute of Technology (Caltech), Earth and Titan share yet another feature, which is inextricably linked with that surface liquid: common fog.

The presence of fog provides the first direct evidence for the exchange of material between the surface and the atmosphere, and thus of an active hydrological cycle, which previously had only been known to exist on Earth.

In a talk to be delivered December 18 at the American Geophysical Union's 2009 Fall Meeting in San Francisco, Brown, the Richard and Barbara Rosenberg Professor and professor of planetary astronomy, details evidence that Titan's south pole is spotted "more or less everywhere" with puddles of methane that give rise to sporadic layers of fog. (Technically, fog is just a cloud or bank of clouds that touch the ground).
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Cells Move in Mysterious Ways, Experiments Reveal


ScienceDaily
Thu, 17 Dec 2009 15:00 UTC
Image
© Christian Franck, Brown University
Three-dimensional cell.
Scientists at Brown University and the California Institute of Technology have for the first time tracked how cells move in three dimensions by measuring the force exerted by them on their surroundings. The scientists' experiments revealed that cells move in a push-pull fashion, such as probing at depth, redistributing weight at various points and coiling and elongating.

Our cells are more like us than we may think. They're sensitive to their environment, poking and prodding deliberately at their surroundings with hand-like feelers and chemical signals as they decide whether and where to move. Such caution serves us well but has vexed engineers who seek to create synthetic tissue, heart valves, implants and other devices that the human body will accept.

To overcome that obstacle, scientists have sought to learn more about how cells explore what's around them. While numerous studies have looked at cellular movement in two dimensions and a few recent experiments involved cellular motion in three dimensions, scientists remained unsure just how much cells interacted with their surroundings. Now, a study involving Brown University and the California Institute of Technology has recorded for the first time how cells move in three dimensions by measuring the force exerted by cells on their environs. The research gives scientists their most complete assessment to date about how cells move.
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Leprosy Susceptibility Genes Identified; Largest Genome-Wide Association Study of an Infectious Disease


ScienceDaily
Thu, 17 Dec 2009 06:00 UTC
In the first genome-wide association study (GWAS) of leprosy and the largest GWAS on an infectious disease, scientists at the Genome Institute of Singapore (GIS) and 26 institutes in China identified seven genes that increase an individual's susceptibility to leprosy.

The discovery of these genes, reported in the 16 Dec. 2009 New England Journal of Medicine, highlights the important role of the innate immune response in the development of leprosy, said the scientists, who analyzed over 10,000 samples from leprosy patients and healthy controls in China.

"Though leprosy is not common, the discoveries have significant ramifications for chronic infectious disorders and for host-pathogen interactions in other more prevalent mycobacterial diseases such as tuberculosis, said Edison Liu, M.D., Executive Director of GIS, one of the research institutes sponsored by Singapore's Agency for Science, Technology and Research (A*STAR).

"This study represents one of the largest and best organized studies of the host genetics in infectious diseases published," added Dr. Liu.
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Attention

Study Proves Three Monsanto Corn Varieties' Noxiousness to the Organism


Truthout
Fri, 11 Dec 2009 15:13 UTC
Image
© DawnOne
GMO cornfields in Canada. A new European study "clearly reveals ... new side effects linked with GM maize consumption" affected the liver and kidneys, but also other organs for three Monsanto GMO corn varieties.
A study published in the International Journal of Biological Sciences demonstrates the toxicity of three genetically modified corn varieties from the American seed company Monsanto, the Committee for Independent Research and Information on Genetic Engineering (Criigen, based in Caen), which participated in that study, announced Friday, December 11.

"For the first time in the world, we've proven that GMO are neither sufficiently healthy nor proper to be commercialized. [...] Each time, for all three GMOs, the kidneys and liver, which are the main organs that react to a chemical food poisoning, had problems," indicated Gilles-Eric Séralini, an expert member of the Commission for Biotechnology Reevaluation, created by the EU in 2008.
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Telescope

Watery "Super Earth" spotted 40 light years from us

John Timmer
Ars Technica
Wed, 16 Dec 2009 16:53 UTC
Image
© ESO/L. Calçada
Our collection of exoplanets continues to expand and, in recent years, some dedicated hardware like CoRoT and Kepler have joined the search in space. But the latest discovery comes from some pretty mundane hardware - a collection of 40cm telescopes - and has some very compelling properties: a super earth that's likely to harbor liquid water, and orbits a star that's close enough to allow current observatories to image its atmosphere.

The results come courtesy of the MEarth project (a description is available via the arXiv), which is based on Mount Hopkins in Arizona. Instead of exotic, high-end optics, MEarth relies on eight 0.4m telescopes that can be pointed independently. The project works because the hardware is pointed at a very carefully chosen collection of stars: about 2,000 nearby M-dwarfs, which, as the name implies, are relatively small stars. That means that even a moderate-sized planet orbiting one will occlude a significant fraction of its surface during transit. The MEarth scopes are able to spot anything that blocks more than a half of a percent of the light as it transits in front of its host star.
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