Science News
Hummingbirds evolved a strange taste for sugar
Nectar-sipping birds seem to have regained a sweet tooth lost by an ancestor
by Laura Sanders
Hummingbirds are drawn to nectar in an unusual way. Instead of depending on a sugar sensor found in many vertebrates, the flitting, frenetic birds use a repurposed sensor that normally responds to savory flavors, scientists report in the Aug. 22 Science.
Researchers led by Maude Baldwin of Harvard University and Yasuka Toda of University of Tokyo studied the genomes of 10 bird species and found no hint of the gene that encodes the sweet detector that most vertebrates rely on. Like those birds, hummingbirds probably also lack the gene, the researchers reasoned. But experiments on cells in dishes revealed that hummingbirds’ umami receptors, which normally detect savory amino acids, pick up the slack and detect sucrose, glucose and fructose.
In both lab tests and the wild, hummingbirds preferred liquid sweetened with sucrose over water. The birds lapped up a low-calorie sweetener called erythritol that the umami receptor can sense, but didn’t enjoy the sugar substitute aspartame, which didn’t get a response from the receptor.
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X-ray laser probes tiny quantum tornadoes in superfluid droplets
DOE/SLAC National Accelerator Laboratory
An experiment at the Department of Energy's SLAC National Accelerator Laboratory revealed a well-organized 3-D grid of quantum "tornadoes" inside microscopic droplets of supercooled liquid helium -- the first time this formation has been seen at such a tiny scale.
The findings by an international research team provide new insight on the strange nanoscale traits of a so-called "superfluid" state of liquid helium. When chilled to extremes, liquid helium behaves according to the rules of quantum mechanics that apply to matter at the smallest scales and defy the laws of classical physics. This superfluid state is one of just a few examples of quantum behavior on a large scale that makes the behavior easier to see and study.
The results, detailed in the Aug. 22 issue of Science, could help shed light on similar quantum states, such as those in superconducting materials that conduct electricity with 100 percent efficiency or the strange collectives of particles, dubbed Bose-Einstein condensates, which act as a single unit.
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Technology News
Motorized Roller Skates That Make 12 MPH Feel Absolutely Terrifying
By Tim Moynihan
Here’s the first thing I learned when riding a pair of RocketSkates: 12 mph might seem slow, but strap a pair of motorized roller skates to your feet and that speed becomes instantly terrifying.
After a quick tutorial, I donned on these hefty electric skates, pushed off, heard the motor kick in with a delightful digitized afterburner sound effect, and… then I immediately freaked out and bailed onto my toes like a chump. This happened roughly 10 times in a row. Luckily, the RocketSkates are easy to stop: You can either lean back on your heel to engage the brake, or you can simply step onto your toes like I did. The footplates of each skate end at about mid-sole, so your toes are always available for freak-out braking.
I’ve ridden electric bikes, electric unicycles, and electric lawnmowers, and nothing felt quite like the feeling of those skates kicking in. That probably has to do with the fact that these wheels are attached directly to your feet. The best balance scenario involves riding with one foot out in front of the other, giving you a wider base for balance. I couldn’t get the hang of using them right away, but I wanted to keep trying.
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Traffic lights are dangerously easy to hack
By Jose Pagliery
Traffic lights all across the United States are dangerously easy to hack.
Anyone with a radio hooked up to a laptop can wreak havoc by remotely changing lights at will -- or by shutting them all down. That's according to findings by computer researchers at the University of Michigan.
"There's an assumption that these devices are secure. We all just trust them so much," said Branden Ghena, a computer science PhD student at the university and the lead researcher on the study. "This is critical infrastructure. We were shocked that was going on."
Under the watchful eye of local transportation officials in May, the Michigan researchers field-tested the hack in an undisclosed Michigan city, changing the traffic lights from a laptop in their truck.
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Environmental News
Severe drought is causing the western US to rise like a spring uncoiling
University of California - San Diego
The severe drought gripping the western United States in recent years is changing the landscape well beyond localized effects of water restrictions and browning lawns. Scientists at Scripps Institution of Oceanography at UC San Diego have now discovered that the growing, broad-scale loss of water is causing the entire western U.S. to rise up like an uncoiled spring.
Investigating ground positioning data from GPS stations throughout the west, Scripps researchers Adrian Borsa, Duncan Agnew, and Dan Cayan found that the water shortage is causing an "uplift" effect up to 15 millimeters (more than half an inch) in California's mountains and on average four millimeters (0.15 of an inch) across the west. From the GPS data, they estimate the water deficit at nearly 240 gigatons (62 trillion gallons of water), equivalent to a six-inch layer of water spread out over the entire western U.S.
Adrian Borsa, an assistant research geophysicist at Scripps Institution of Oceanography, UC San Diego.
Results of the study, which was supported by the U.S. Geological Survey (USGS), appear in the August 21 online edition of the journal Science.
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Sunlight, not microbes, key to carbon dioxide in Arctic
Oregon State University
The vast reservoir of carbon stored in Arctic permafrost is gradually being converted to carbon dioxide (CO2) after entering the freshwater system in a process thought to be controlled largely by microbial activity.
However, a new study -- funded by the National Science Foundation and published this week in the journal Science -- concludes that sunlight and not bacteria is the key to triggering the production of CO2 from material released by Arctic soils.
The finding is particularly important, scientists say, because climate change could affect when and how permafrost is thawed, which begins the process of converting the organic carbon into CO2.
"Arctic permafrost contains about half of all the organic carbon trapped in soil on the entire Earth -- and equals an amount twice of that in the atmosphere," said Byron Crump, an Oregon State University microbial ecologist and co-author on the Science study. "This represents a major change in thinking about how the carbon cycle works in the Arctic."
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Medical News
Laser device may end pin pricks, improve quality of life for diabetics
Princeton University, Engineering School
Princeton University researchers have developed a way to use a laser to measure people's blood sugar, and, with more work to shrink the laser system to a portable size, the technique could allow diabetics to check their condition without pricking themselves to draw blood.
"We are working hard to turn engineering solutions into useful tools for people to use in their daily lives," said Claire Gmachl, the Eugene Higgins Professor of Electrical Engineering and the project's senior researcher. "With this work we hope to improve the lives of many diabetes sufferers who depend on frequent blood glucose monitoring."
In an article published June 23 in the journal Biomedical Optics Express, the researchers describe how they measured blood sugar by directing their specialized laser at a person's palm. The laser passes through the skin cells, without causing damage, and is partially absorbed by the sugar molecules in the patient's body. The researchers use the amount of absorption to measure the level of blood sugar.
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Children with autism have extra synapses in brain: May be possible to prune synapses with drug after diagnosis
Columbia University Medical Center
Children and adolescents with autism have a surplus of synapses in the brain, and this excess is due to a slowdown in a normal brain "pruning" process during development, according to a study by neuroscientists at Columbia University Medical Center (CUMC). Because synapses are the points where neurons connect and communicate with each other, the excessive synapses may have profound effects on how the brain functions. The study was published in the August 21 online issue of the journal Neuron.
A drug that restores normal synaptic pruning can improve autistic-like behaviors in mice, the researchers found, even when the drug is given after the behaviors have appeared.
"This is an important finding that could lead to a novel and much-needed therapeutic strategy for autism," said Jeffrey Lieberman, MD, Lawrence C. Kolb Professor and Chair of Psychiatry at CUMC and director of New York State Psychiatric Institute, who was not involved in the study.
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Space News
Astronomers Capture Spectacular NGC 3576, NGC 3603
A group of astronomers using the Wide Field Imager at ESO’s La Silla Observatory has captured an image of two intriguing and beautiful star formation regions in our Milky Way Galaxy known as NGC 3603 and NGC 3576.
by Sci-News.com
NGC 3576, also known as the Statue of Liberty Nebula and ESO 129-EN5, was discovered by John Herschel in 1834.
It drifts through the Sagittarius arm of our Milky Way Galaxy, about 9,000 light-years away.
Within the region, episodes of star formation are thought to contribute to the complex and suggestive shapes.
Strong stellar winds from the NGC 3576′s embedded young, massive stars shape two huge filaments resembling the curled horns of a ram.
Also discovered by John Herschel in 1834, NGC 3603 is a glowing cloud of gas, dust, and stars some 20,000 light years distant toward the constellation Carina.
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Scientists Discover 101 Geysers on Enceladus
A team of U.S. researchers using data from NASA’s Cassini spacecraft has discovered 101 active geysers erupting on Enceladus, the sixth-largest moon of Saturn.
by Sci-News.com
After the first sighting of geysers on Enceladus in 2005, planetary scientists suspected that repeated flexing of the moon by Saturn’s tides as the moon orbits the planet had something to do with their behavior.
One suggestion included the back-and-forth rubbing of opposing walls of the fractures generating frictional heat that turned ice into geyser-forming vapor and liquid.
Alternate views held that the opening and closing of the fractures allowed water vapor from below to reach the surface.
To determine the surface locations of the geysers, University of California and Space Science Institute scientists employed the same process of triangulation used historically to survey geological features on Earth, such as mountains.
When they compared the geysers’ locations with maps of thermal emission, it became apparent the greatest geyser activity coincided with the greatest thermal radiation. Comparisons between the geysers and tidal stresses revealed similar connections.
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Odd News
Beam Trees
SLAC
Some very beautiful designs are made in clear plastic by bombarding the plastic with a defocused low-energy electron beam traveling almost the velocity of light.
The electrons penetrate the plastic about a quarter of an inch, and then stick there without visual effect. As more and more electrons are embedded in the plastic, their mutual repulsion causes great forces to build in the plastic to expel them.
If the filling process is stopped before the electrons break out, a small prick with a metal punch at one point on the surface of the plastic will cause all of the electrons to come out at that point with an arc and a bang.
Permanent damage to the plastic caused by the current flow appears as a tree-like structure, though more accurately it should be viewed as a map of the confluence of many small streams flowing into larger ones and eventually to a single river of charge exiting at the discharge point. This tree-like structure is known as a Lichtenberg figure or Lichtenberg tree, and is named for Georg Christoph Lichtenberg (1743-1799) who first documented the phenomenon.
During the bombardment process, 16 inches of steel are used to shield the operators from the electron beam's radiation. After about a minute the beam is turned off, and the plastic block is ready to be pricked. At first the plastic retains a brown color due to the intense radiation caused by the electrons striking it. But the plastic does not retain any radiation, and is completely harmless. In time, the brown color fades and disappears. (Placing the block in direct sunlight will speed the process.)
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