Friday, 31 December 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Climate Models Miss Effects of Wind-Shattered Dust

Posted: 30 Dec 2010 11:01 AM PST

Clumps of dust in the desert shatter like glass on a kitchen floor. This similarity may mean the atmosphere carries more large dust particles than climate models assume.

Dust and other airborne particles' effect in the atmosphere is "one of the most important problems we need to solve in order to provide better predictions of climate," said climate scientist Jasper Kok of the National Center for Atmospheric Research in Boulder, Colorado. Other researchers suspect current models also neglect a large fraction of the climate-warming dust that clogs the skies after dust storms.

Most climate models use dust data from satellites that measure how many particles of different sizes are suspended in the atmosphere. These measurements reveal an abundance of tiny clay particles roughly 2 micrometers across (about one-third the width of a red blood cell), which can reflect sunlight back into space and cool the planet.

But satellites may be missing larger particles, called silts, which don't hang around in the air as long. Silts up to 20 micrometers in diameter can act as a warm blanket to trap heat inside the Earth's atmosphere.

To figure out how much clay and silt is actually kicked up from the Earth's deserts, Kok turned to a well-studied problem in physics: how glass breaks.


Cracks spread through breaking glass in specific patterns, creating predictable numbers and sizes of glass shards. The final distribution of small, medium and large glass fragments follows a mathematical law called scale invariance.

"It shows up all across nature, from asteroids to atomic nuclei," Kok said. "It's really just beautiful."

In a paper published Dec. 28 in the Proceedings of the National Academy of Sciences, Kok showed that the physics of how dust clumps break apart is similar to glass breaking.

Soil scientists have long known that dust clumps act like brittle materials, and physicists have well-tested mathematical descriptions of how brittle materials break. "But no one had put one and two together," Kok said.

When wind picks up in the desert, Kok says, the particles that move first are large sand particles, up to 500 micrometers across. Silt-sized and smaller dust grains tend to stick together until a bouncing sand particle smacks into them.

"It's physically analogous to hitting your windshield with a hammer, or dropping a drinking glass on the kitchen floor," Kok said.

Cracks spread through the clump of soil as they would through a pane of glass, sending the same fraction of small, medium and large particles bouncing into the atmosphere. Kok compared his theory to ground measurements made in the middle of dust storms in six locations around the world and found they matched perfectly.

"Even though we don't have an abundance of measurements, I think we have sufficient measurements to say this theory is a step in the right direction," Kok said.

Kok's theory suggests that dust storms produce two to eight times more silt-sized particles than climatologists previously thought. Neglecting the boost in particles suggests that climate models, and even short-term weather models for dusty regions, are somewhat off. Until climate scientists better understand how dust changes over time, however, Kok said it's tough to gauge the effects.

"I thought it was a breakthrough, a real original idea," said atmospheric physicist Charles Zender of the University of California at Irvine, who was not involved in the new work. Similarities to fractured glass may show up in other earth science systems, like earthquakes or glacier calving, he added. "Whether it's submicron and invisible to the human eye, or as large as Greenland, it doesn't matter. It's the same property."

Dust expert Tom Gill of the University of Texas at El Paso thinks Kok's theory is elegant, though it will have to be backed up by lab and field experiments. If it holds up, however, "it has the potential to make some real improvements in modeling how dust and dust-like things move around and disperse and fall out of the air. That has implications for everything from global climate to volcanoes to hurricanes," he said. "I'm very encouraged by it."

Image: A dust storm in Asia in 2001. /NASA

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Top Scientific Breakthroughs of 2010

Posted: 30 Dec 2010 04:00 AM PST

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In a year full of major advances, over-hyped findings and controversial studies, it was tough for the Wired Science staff to choose which breakthroughs were the biggest in 2010. So we've collected the ones that stood out the most to us.

From synthetic life and three-parent embryos to the possibility of a new human ancestor and a habitable exoplanet, here are the breakthroughs that made us shout "Science!" the loudest this year.

Dinosaur Colors

For the first time, scientists were able to use direct fossil evidence to make a reasonable interpretation of a dinosaur's color.

Building on the discovery of preserved traces of pigment structures in cells in fossilized dinosaur feathers (above), paleontologists compared the dinosaur cells with the corresponding cells in living birds. By studying the colors created by different combinations of these melanosomes in bird feathers, the researchers recreated the coloring of a recently discovered feathered dinosaur, Anchiornis huxleyi (right).

The dinosaur probably had bright orange feathers on its head and speckled on its throat, a grey body and white accents on its wings.

The same technique was subsequently used to determine the color of a giant fossil penguin.

Images: 1) Sam Ose /Wikimedia Commons 2) Michael DiGiorgio/Yale University

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Thursday, 30 December 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

U.S. Science-Funding Boost Faces Uncertain Future

Posted: 29 Dec 2010 02:10 PM PST

Despite coming under attack by congressional republicans, federal science funding has received a major and mostly overlooked boost.

The America Competes Act, passed by Congress shortly before Christmas, calls for $46 billion in science and technology research funding over the next three years.

Final approval awaits the signature of President Barack Obama, who in a recent speech framed the need for continued research support.

"Our generation's Sputnik moment is back," he said, referring to the 1957 Soviet satellite launch that catalyzed the U.S. space program and accelerated the development of American technology.


The act was overshadowed by the Democrats' other legislative victories after midterm election losses and the successful Republican defense of tax cuts for the wealthy.

Legislation on gays in the military, food safety, health care for 9/11 first responders and additional economic stimulus spending all had higher profiles than science funding, leaving the passage of America Competes remarked mostly by press releases and trade publications.

As Eli Kintisch noted for ScienceInsider, President Obama declined to mention the act during the week before Christmas. That omission may signal trouble, as passage of the act doesn't guarantee its funding.

In January and February, Congress will decide how much money will actually be spent on it. House Republicans have made the National Science Foundation a symbol of wasteful spending, so America Competes may still lose.

It fell to Presidential science advisor John Holdren to celebrate the act's passage on the White House blog.

"Full funding of the Competes Act is among the most important things that Congress can do to ensure America's continued leadership in the decades ahead," he wrote.

The act calls for a total of $7.4 billion above 2010 funding levels, directed towards a host of agencies including the Department of Energy, the National Institute for Science and Technology, and the National Science Foundation. It shifts funding away from basic research and towards applications, and calls for regular X-Prize-style competitions to solve engineering problems.

The act is rooted in a 2005 National Academies report, "Rising Above the Gathering Storm: Energizing and Employing America," and its sequel released in September.

America's "vitality is derived in large part from the production of well-trained people and the steady stream of scientific and technical innovations they produce," concluded the first report. "Without a renewed effort to bolster the foundations of our competitiveness, we can expect to lose our privileged position," warned the latter.

During its crafting in congressional committee last spring, America Competes received bipartisan support. It was held up, however, by Representative Ralph Hall (R-Texas), formerly the ranking Republican member of the House Committee on Science and Technology.

Hall's objections failed to stop the act, but he is now the science committee's incoming chair.

Image: Replica of Sputnik 1./Wikimedia Commons.

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The Weirdest Indicators of Serious Medical Risks

Posted: 29 Dec 2010 12:10 PM PST

As databases of information about people's lifestyles and medical ailments grow, ever-stranger omens of our health seem to emerge.

Today's computer-powered studies allow researchers to look beyond obvious health risks of the past. New analyses show, for example, that finger length, grip strength and even height may be reliable predictors of cancer, longevity and heart disease.

But not all statistically-based findings are created equal, said Rebecca Goldin, a mathematician at George Mason University and volunteer for

"It's easy to get results that look impressive by trying a whole bunch of things on large databases of information. Things pop out, but they can be completely spurious because of chance," Goldin said. "It's now a fairly common thing to see something published and have someone say that it's not true."

Although the ease of mining medical databases for results can outpace scientists' abilities to review them (clinical trial journals alone publish about 75 in-depth studies every day, yet only 11 reviews of these studies), some do stand up to statistical and cause-and-effect scrutiny.

We recap here some of the weirdest, yet credible, indicators of medical risks ever discovered.


Finger Length

At least two genes — HOXA and HOXD — control testicle development in the womb, and testicles in turn create testosterone. But these two genes also mandate hand development, especially the index and ring fingers.

The discovery has spawned odd testosterone-based hypotheses about what the ratio of the two fingers means, from sexual fitness and exam performance to personality and sporting ability.

Most of the proposals have fallen short of any meaningful significance, but an upcoming study in the British Journal of Cancer suggests there is a significant link to prostate cancer: If the index finger is longer than the ring finger, a man is less likely to develop the cancer.

"It seems strange, but this isn't guesswork," said Rosalind Eeles, cancer geneticist at the Institute for Cancer Research (ICR) in London and co-author of the study.

Eeles and her team compared more than 1,500 men with prostate cancer against more than 3,000 random men. Ignoring family history and other factors, men older than 60 years with a longer index finger were 33 percent less likely (on average) to develop prostate cancer. Younger men with a longer index finger fared even better, with an 87 percent average reduction in risk.

The association still needs to be tried against other populations to be a meaningful assessment of prostate cancer risk, but Goldin said "its speed and non-invasiveness does have something going for it."

"It's way too early to say how much hand screening could help," said Elizabeth Rapley, a molecular geneticist and spokesperson for ICR. "If anything, it gives us more of a handle on how prostate cancer starts, that testosterone may have big role in the development of the disease."

Grip Strength

According to a 25-year study of more than 6,000 men aged 45 through 68, grip strength was the best predictor of how well they'd avoid being disabled later in life. The weakest-gripping men suffered twice the disabilities of strongest grippers. And in a separate study of older men and women, good grip strength was correlated with longer lifespan.

But correlation is not causation. The best bet to living a long life, according to a plethora of research, is eating well, exercising regularly and avoiding harmful habits like smoking.


The crud between your teeth may seem innocuous, but study after study has shown chronic infections of the mouth (also called periodontal diseases) increase the risk of circulatory woes, including coronary heart disease.

Mouth bacteria sneaking into the blood via the gums, the thinking goes, may lead to more heart-clogging arterial plaques. Inflammation caused by such a persistent infection may also prime the body for heart attacks.


If you're close to an airport and can fly cheap, you may get to see more of the world, but this could also increase your risk of developing skin cancer.

During a British economic rebound in the 1970s, Rapley said, people enjoyed the jump in their money's value by traveling abroad.

"Many of them went to the beaches of Spain and spent a lot of time in the sun," she said. "We now see an increase in the rate of melanoma in that population."

Birth Order

First-born boys may be more likely to develop testicular cancer later in life.

"Lots of series of studies suggest the first child is exposed to higher levels of estrogen, which gives greater risk of testicular cancer. But this has never been definitively proven," Rapley said.

Chemicals similar to estrogen are one major suspect for the doubling of testicular cancer in the past 40 years (an increase not from improved screening, she said). Estrogen analogs may get into food and water supplies, for example, from the pesticides they're found in.

Perhaps the strongest medical risk of early birth order is childhood leukemia. It develops more often in older siblings and seems to be tied to socioeconomic status. Rapley suspects immune-system training may also be part of the explanation.

"There are suggestions that it may have to do with exposure to viruses and colds and bacteria," she said. Siblings aren't around to give them as much exposure, she said, so "kids who go to child-care at an early age are less likely to develop leukemia than kids kept at home."

In assessing any database-powered medical study, Goldin said it's important to look for large sample sizes, proposed causes, accounting for chance and extraneous effects, and acknowledgment of other hypotheses. But putting a health risk into perspective is perhaps the most important thing of all.

"There's a lot of medicine where it's just not clear how helpful it is to know something," Goldin says. "If you're doubling your risk of one in a million, for example, that's still two in a million. Unless it's got some significant impact to way we evaluate treatment, it's hard to see any benefit."


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Wednesday, 29 December 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

The World’s Biggest, Iciest Particle Detector

Posted: 28 Dec 2010 01:52 PM PST

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Construction of the world's largest particle detector is now complete after 10 years of drilling deeper than a mile into ultraclear Antarctic ice.

Called the IceCube, the three-dimensional array of sensors can detect neutrinos expelled by some of the universe's most violent sources, including black holes, supernovas and energetic stars.

Neutrinos weigh hardly anything, so the particles usually travel through matter — including the sun and Earth — without interacting. But every now and then they slam into the cores of atoms to create nuclear particle showers. The events emit faint blue trails of light which IceCube's 5,160 sensors can track with extreme precision.

"About one in a million neutrinos crash into a proton. We're measuring the energy and the directions of those nuclear reactions to build a neutrino-based map of the sky," said Francis Halzen, a theoretical physicist at the University of Wisconsin-Madison and leader of IceCube.

The $100-million neutrino-detection effort is one of the most challenging ever attempted by engineers and physicists, Halzen said.

"Nobody would have bet on the success of this project, and rightfully so," Halzen said. "If we knew how complex it would be to build, we may have never started."

In this gallery, take a tour of the world's biggest, iciest particle detector.

Video: Animations show the drilling of IceCube's 1.5-mile-deep holes, the completed array of light-detecting sensors and a simulation of a neutrino collision event.
Credit: NSF, IceCube/University of Madison-Wisconsin and Chris Bickel.

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Rare Cambodian Elephant Captured on Video

Posted: 28 Dec 2010 11:11 AM PST

A rare Cambodian elephant has finally been caught on video.

The footage was taken in August by photographer Allan Michaud for the Wildlife Conservation Society, who say it's the first high-quality video of an Asian elephant in Cambodia.

Michaud filmed the adult male in the Seima Forest, a Rhode Island–sized sanctuary along the country's border with Vietnam.

Newly protected by Cambodia's government and the WCS, the forest is home to some of Asia's rarest creatures: tigers, forest bison, langurs and, of course, elephants. But decades of war and instability, followed by contemporary threats from poaching and development, have spooked the gentle, highly social creatures.

From their droppings, a 2006 survey of Seima's elephants counted 116, but without actually seeing a single animal. Most photos have come from camera traps. According to WCS researcher Edward Pollard, the video is "visual confirmation that Seima is vitally important for biodiversity."

And for those people less moved by biodiversity than life, it's a rare glimpse of a magnificent animal.

Video: Allan Michaud, Wildlife Conservation Society.

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Brain Volume Linked to Social Networking

Posted: 28 Dec 2010 10:00 AM PST

By Yun Xie, Ars Technica

The size of your amygdala might indicate how large and complex your social network is. Amygdala volume has been connected to social network and behavior in past research, as scientists have found that nonhuman primate species with larger social groups tend to have greater amygdala volumes. Kevin Bickart and his coauthors took the next logical step and examined how amygdala volume varies in humans with different social networks. Their results appear in a recent issue of Nature Neuroscience.

The researchers measured two social network factors in 58 adults. First, they calculated the size of a participant's network, which is simply the total number of people who are in regular contact with the participant. Second, they measured the network's complexity, based on how many different groups a participant's contacts can be divided into. The authors then examined how well those two factors correlated with the size of a participant's amygdala and hippocampus. The hippocampus served as a negative control, as it should not vary based on social networks.

Linear regression revealed a positive correlation in amygdala size with both social network size and complexity. This effect showed no lateralization, meaning both left and right amygdala volumes followed this relationship. In addition, the effect is relatively specific, as other social factors like life satisfaction and perceived social support failed to correlate with amygdala volume.


Social network size and complexity did not significantly correspond with the size of the hippocampus or other subcortical areas. The authors did find that three regions in the cerebral cortex of the brain (caudal inferior temporal sulcus, caudal superior frontal gyrus, and subgenual anterior cingulate cortex) might correlate with social networks. They propose that those regions might have evolved along with amygdala to deal with the complexities of growing social circles.

This is one of the first publications that demonstrates a relationship between amygdala volume and social networks in humans. It would be fascinating to determine if a cause-and-effect relationship can be established. Are certain people born with larger amygdala and therefore create bigger social networks, or does the amygdala grow as we gain more friends and foes?

Images: 1) Flickr/AJ Cann. 2) Amygdala position./NIH.

Nature Neuroscience, 2010. DOI: 10.1038/nn.2724

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Tuesday, 28 December 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Gigantic Storm With Huge Tail Erupts on Saturn

Posted: 27 Dec 2010 01:00 PM PST

An enormous storm has erupted in Saturn's northern hemisphere.

Amateurs first sighted the storm earlier this month, but the Cassini spacecraft moved into a good position on Dec. 24 to photograph it from about 1.1 million miles away. Earth received the raw and unprocessed shots today.

The storm has a huge central funnel and a long tail that sweeps around Saturn's northern hemisphere for tens of thousands of miles. A shot in blue light (left) reveals the extent of the tail, but infrared light (right) shows detail of the storm's amorphous core. The photos were taken exactly a month after Cassini recovered from a solar-flare-induced error that temporarily silenced the spacecraft from Nov. 2 through Nov. 24.

Saturn's weather is complex like Jupiter's, but it's often difficult to see such storms beneath Saturn's hazy outer atmosphere, wrote Carolyn Porco, a planetary scientist and leader of Cassini's imaging team, on Twitter.


Images: NASA/JPL/Space Science Institute

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Honeybees May Be Spreading Disease to Wild Bees

Posted: 27 Dec 2010 10:16 AM PST

Eleven species of wild pollinators in the United States have turned up carrying some of the viruses known to menace domestic honeybees, possibly picked up via flower pollen.

Most of these native pollinators haven't been recorded with honeybee viruses before, according to Diana Cox-Foster of Pennsylvania State University in University Park. The new analysis raises the specter of diseases swapping around readily among domestic and wild pollinators, Cox-Foster and her colleagues report online Dec. 22 in PLoS ONE.

Gone are any hopes that viral diseases in honeybees will stay in honeybees, she says. "Movement of any managed pollinator may introduce viruses."

A pattern showed up in the survey that fits that unpleasant scenario. Researchers tested for five viruses in pollinating insects and in their pollen hauls near apiaries in Pennsylvania, New York and Illinois. Israeli acute parasitic virus showed up in wild pollinators near honeybee installations carrying the disease but not near apiaries without the virus.

In domestic honeybees, such viruses rank as one of the possible contributors to the still-mysterious malady known as colony collapse disorder that abruptly wipes out a hive's workforce, Cox-Foster says.


Now she and others are looking at what the viruses do to wild pollinators. Preliminary results of ongoing lab tests show some disturbing effects, Cox-Foster says. "Is this part of the reason why we've seen the decline of native pollinator species in the U.S.?" she muses.

Surveys show that wild bumblebees, for example, are dwindling in numbers, and the new study raises further concerns. "We recognize that those viruses likely pose a major threat to wild bumblebees," says Sarina Jepsen of the Xerces Society, an invertebrate conservation group in Portland, Oregon.

One of the most interesting results in the study is the detection of deformed-wing virus and sacbrood virus in pollen carried by foraging bees that weren't infected themselves, comments Michelle Flenniken of the University of California, San Francisco, who has studied bee viruses but was not involved in the new work.

Healthy foraging insects carrying virus-laden pollen are one of the pieces of evidence that Cox-Foster and her colleagues use to argue that pollen by itself can transmit viral infections. "Knowing that viruses are found in and can be transmitted from pollen is an important finding," says Flenniken.

This raises concerns about possible virus transmission through the 200 tons of honeybee-collected pollen used to feed bumblebees in bee-raising operations worldwide, Cox-Foster says.

Image: A wild bee (the bumblebee, Bombus vosnesenskii) and a honey bee forage together on a sunflower. Sarah Greenleaf/UC Berkeley

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Snowflakes Under an Electron Microscope

Posted: 27 Dec 2010 09:41 AM PST

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If you've ever wondered what snowflakes truly look like, spend a few moments with these images from the Electron Microscopy Unit of the Beltsville Agricultural Research Center in Beltsville, Maryland.

At the EMU, where other areas of focus include crop pathogens and livestock diseases, "studying the structure of snow is vital to several areas of science as well as to activities that affect our daily lives."

That's no doubt true. But for the rest of us, snow's structure is just beautiful. Enjoy!

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Image: Electron and Confocal Microscopy Laboratory, Agricultural Research Service, U. S. Department of Agriculture.

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