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."
Science & Technology
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.
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.
© NASA
A gravity tug
A gravity tug
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.
© 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.
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.
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).
© Christian Franck, Brown University
Three-dimensional cell.
Three-dimensional cell.
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.
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.
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.
© 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.
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.
"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.
© ESO/L. Calçada
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.
© Unknown
First hypothesized 60 years ago by planetary expert Gerard Kuiper, the existence of such an outer comet belt wasn't proven to exist until astronomers began discovering objects in the Kuiper Belt (other than Pluto) in the early 1990s. Now Hubble Space Telescope has stumbled across the smallest thing ever seen in the Kuiper belt.
The previous record holder is 30 miles across. But the interloper Hubble spotted is merely one half-mile across. It would just stretch across the width of New York City's Central Park. In terms of angular size, the object would be the apparent width of a dime located 1/3rd of the way between here and the moon! It is 100 times fainter that Hubble's detection limit.
So how did the Hubble ever uncover such a puny object?
It's a world first: thanks to new technology developed by the University of Victoria, Canada, researchers can now show how multiple parts of the right brain dynamically process spatial relationships.
"We already know that most people's right brains deal with the relationship between things in 3-D space," says UVic researcher Phil Zeman. "But until now we didn't know how multiple areas in the right brain interact with each other for spatial processing. This information is vital to understanding the key functions of the right brain, including why people with traumatic brain injury have difficulties with spatial navigation and how pharmaceuticals such as antidepressants affect the brain."
Zeman, along with his supervisor Dr. Ron Skelton, and PhD student Sharon Lee, are using UVic-developed technology to show how people process information. The MOST-EEG (Multiple Origin Spatio-Temporal -EEG) uses the electrical activity obtained from a person's scalp, recorded while a study participant plays a video game for example, to construct a meaningful representation of the brain activity that took place while the participant learned and used the layout of the virtual environment.
"We already know that most people's right brains deal with the relationship between things in 3-D space," says UVic researcher Phil Zeman. "But until now we didn't know how multiple areas in the right brain interact with each other for spatial processing. This information is vital to understanding the key functions of the right brain, including why people with traumatic brain injury have difficulties with spatial navigation and how pharmaceuticals such as antidepressants affect the brain."
Zeman, along with his supervisor Dr. Ron Skelton, and PhD student Sharon Lee, are using UVic-developed technology to show how people process information. The MOST-EEG (Multiple Origin Spatio-Temporal -EEG) uses the electrical activity obtained from a person's scalp, recorded while a study participant plays a video game for example, to construct a meaningful representation of the brain activity that took place while the participant learned and used the layout of the virtual environment.
