- EPA Orders BP to Use Less-Toxic Oil Dispersant
- Lightning May Cause Hallucinations
- Hubble Watches as Star Slowly Devours Planet
- Scientists Create First Self-Replicating Synthetic Life
- Video: An Artificial Butterfly Takes Flight
- Argonaut Octopus Mystery Solved
- 30-Year Time-Lapse: Mount St. Helens Recovery From Space
- Foucault’s Pendulum Dented in Museum Mishap
- Dementia Caregivers More Likely to Also Get the Disease
- Judge Issues Legal Opinion in Brooklyn fMRI Case
Posted: 20 May 2010 02:32 PM PDT
The Environmental Protection Agency ordered British Petroleum to change the type of dispersant the company is using to keep oil from reaching American shores.
The EPA gave the company 72 hours to switch to a less toxic chemical for use in breaking up oil slicks. Persistent questions about the toxicity of Corexit 9500 have plagued BP over the last several weeks. But the company continued to purchase and use the chemical.
On May 5, Wired Science reported on EPA data showing that a competitive product, U.S. Polychemical's Dispersit, appeared to be less toxic and perform better. Corexit is manufactured by Nalco, which has senior management from the major oil companies.
"The reality is, we blow them out of the water. But Corexit is the Exxon product, the 800-pound gorilla," U.S. Polychemical's Bruce Gebhardt told Wired Science two days later. "We've never been able to move off the shelves. We were never successful in getting them to switch stockpiles. The Coast Guard expressed interest, but it's a big expense, and you don't do it unless you're in pain. Now they're in pain."
Now, while BP has not announced how it will comply with the EPA order, U.S. Polychemical told The New York Times it had "received a large order from BP" for Dispersit and could ramp up production to 60,000 gallons a day.
Image: A Coast Guard plane spraying dispersant./ U.S. Coast Guard.
Posted: 20 May 2010 01:05 PM PDT
Talk about a flash of insight. Lightning strokes could stimulate people's brains and cause them to hallucinate bright blobs of light the same way a medical procedure that applies magnetic fields to the brain does, two physicists propose. The findings could help explain some reports of "ball lightning," mysterious floating orbs that have been reported for centuries but are poorly understood. A paper describing the idea will appear in Physics Letters A.
"We don't claim to have a solution for the mystery of ball lightning," says study co-author Alexander Kendl, a plasma physicist at the University of Innsbruck in Austria. "But this is a possible hypothesis."
Lightning forms when electrical charges become physically separated in a storm cloud and build up electrical potential between them, which is then discharged in the sudden bolt. Strokes typically come in clusters. In some cases, Kendl says, they can come extremely rapidly: something like 20 to 60 lightning strokes, each on the order of 100 milliseconds long, raining down over the course of several seconds.
These rare repetitive strokes, Kendl's team found, generate magnetic fields that are very similar — in strength and in how they rise and decay over time — to those used in a brain-stimulation technique called transcranial magnetic stimulation, or TMS.
TMS applies magnetic fields to the brain to treat neurological and psychiatric conditions like stroke and depression. While the stimulation is being applied to the visual cortex, some patients report seeing blobs of light in their field of vision. Such experiences, of seeing light when light is not actually entering the eye, are known as phosphenes. (The patterns of light you see when you rub your closed eyes hard are another type of phosphene.)
Working with Innsbruck graduate student Josef Peer, Kendl calculated that repetitive lightning strokes would trigger phosphenes "astonishingly well." A person would need to be within about 200 meters of the lightning to experience the effect.
But Thomas Kammer, a TMS expert at the University of Ulm in Germany, isn't convinced. Patients report seeing many different kinds of TMS-induced phosphenes, but they don't generally mesh with descriptions of ball lightning. "I cannot imagine that long-lasting visual phenomena as described with ball lightning might be based on induced phosphenes," Kammer wrote in an e-mail.
Scientists have proposed before that ball lightning reports could be ascribed to visual hallucinations, but the new study is the first to quantify the phenomenon in such detail and relate it to a known phenomenon. In 2008, researchers in Sweden proposed that magnetic fields associated with lightning could affect neurons in the part of the brain known as the occipital lobe, setting off epileptic seizures and inducing visions later described as ball lightning.
"Evidence is mounting that most, if not all, of ball lightning observations are created by the interaction of lightning-generated magnetic fields with the human brain," says a co-author of that study, electricity expert Vernon Cooray of Uppsala University in Sweden.
Scientists have struggled for centuries to explain ball lightning, in part because reports of it are so varied. It is often described as a yellowish ball that hovers around eye height for a couple of seconds before vanishing. But other reports describe ball lightning of various colors moving rapidly, fizzling or even exploding; some say it is accompanied by a sharp smell or sound.
The diversity of descriptions, Kendl says, suggests ball lightning may be a catchall term describing many different types of experience.
Image: Ball Lightning, 1886./G. Hartwig, NOAA Photo Library collection.
Posted: 20 May 2010 11:39 AM PDT
Six hundred light-years from Earth, a huge exoplanet circling close to its home star is slowly, inexorably being devoured.
WASP 12B orbits just 2 million miles from its star, which means the surface of the planet reaches temperatures over 2,800 Fahrenheit. The sun's gravitational pull is stronger on the front surface of the planet than on the back, so the planet has been pulled into a football shape. If you were floating on the gaseous planet, and looking heavenward, the sun would take up nearly the entire sky.
And in the next 10 million years, the star that so dominates the planet will destroy it, according to a paper published in May in The Astrophysical Journal Letters.
It's not exactly the kind of solar system that human beings anticipated finding in the great beyond.
"All sorts of things that we
She and her team used the Hubble Space Telescope's Cosmic Origins Spectrograph to investigate the planet by looking in the ultraviolet part of the spectrum.
"The near ultraviolet is a very sensitive probe to the presence of stuff and that allows you to deduce an effective radius for the planet," she said.
WASP 12B has a puffed up atmosphere that its star is siphoning off. That observation happily matches theoretical predictions made just a few months ago by astronomer Shu-lin Li at Peking University, Beijing. The confirmation shows yet again that exoplanetology, particularly the study of other solar systems not just individual planets, is advancing at a breakneck pace.
"It is a really nice example of theorists predicting something and we'd already observed something close to what they predicted," Haswell said.
To date, 455 exoplanets have been discovered.
Posted: 20 May 2010 11:32 AM PDT
Man-made DNA has booted up a cell for the first time.
In a feat that is the culmination of two and a half years of tests and adjustments, researchers at the J. Craig Venter Institute inserted artificial genetic material — chemically printed, synthesized and assembled — into cells that were then able to grow naturally.
"We all had a very good feeling that it was going to work this time," said Venter Institute synthetic biologist Daniel Gibson, co-author of the study published May 20 in Science. "But we were cautiously optimistic because we had so many letdowns following the previous experiments."
On a Friday in March, scientists inserted over 1 million base pairs of synthetic DNA into Mycoplasma capricolum cells before leaving for the weekend. When they returned on Monday, their cells had bloomed into colonies.
"When we look at life forms, we see fixed entities," said J. Craig Venter, president of the Institute, in a recent podcast. "But this shows in fact how dynamic they are. They change from second to second. And that life is basically the result of an information process. Our genetic code is our software."
Coaxing the software to power a cell proved harder than expected.
After the Venter Institute announced in early 2008 that it had assembled a synthetic Mycoplasma genitalium genome, the assumption was that it would be running cells in no time. But this particular cell type, despite its minimal size, was not an ideal research partner. One problem was speed.
"We had to deal with the fact that M. genitalium had an extremely slow growth rate," Gibson said. "For every experiment that was done, it took more than a month to get results."
Moreover, transplanting the code into recipient cells was failing. So researchers cut their losses and called in a substitute, opting for the larger, speedier and less finicky Mycoplasma mycoides. The choice was a good one.
"Over the last five years the field has seen a 100-fold increase in the length of genetic material wholly constructed from raw chemicals," said synthetic biologist Drew Endy of Stanford University. "This is over six doublings in the max length of a genome that can be constructed."
Plunging costs of synthesis allowed a leap past the 1 million base-pair mark, from code to assembly. "Imagine doubling the diameter of a silicon wafer that can be manufactured that much, going from 1 cm to 1 meter [fabrications] in just five years," Endy said. "That would have been an incredible achievement."
"They rebuilt a natural sequence and they put in some poetry," said University of California at San Francisco synthetic biologist Chris Voigt. "They recreated some quotes in the genome sequence as watermarks."
It's an impressive trick, no doubt, but replicating a natural genome with a little panache is also the limit of our present design capabilities.
Researchers, for instance, figure yeast can handle the assembly of 2 million base pairs, but they're not sure about more. And an energy-producing cyanobacteria that sequesters carbon, Gibson says, is still several years off.
The ultimate goal, of course, is a brand-new genome from the ground up. Now, Voigt said, "what do you do with all that design capacity?"
Images: 1) Schematic demonstrating the assembly of a synthetic M. mycoides genome in yeast./Science/AAAS. 2) Images of the phenotype of the JCVI-syn1.0 and WT strains./Science/AAAS.
Posted: 19 May 2010 12:49 PM PDT
A tiny artificial butterfly takes flight in a new high-speed video.
Engineers Hiroto Tanaka and Isao Shimoyama of Harvard University and University of Tokyo, respectively, created the tiny butterfly to try to understand the biomechanics of butterfly flight.
But the tiny machine may not teach us too much about how butterflies actually row through the air, said Robert Dudley, a physiologist at the University of California, Berkeley, co-author of the research to be published May 20 in the journal Bioinspiration & Biomimetics.
"As a technical accomplishment, this work is impressive, but there are a number of aerodynamic and biological issues that need further attention," Dudley wrote in an e-mail to Wired.com.
Butterfly flight is somewhat mysterious because it's roughly the opposite of "as the crow flies." Butterflies flit about rather than flying in a straight line. That actually costs them more energy, Dudley said, so scientists assume their looping flying serves some evolutionary purpose.
"The advantage is that it's thought to be an anti-predator behavior," Dudley said. "The claim is that irregular flight paths are a permanent signal of prey unprofitability."
Would-be predators presumably take one look at the chaotic, loopy butterfly flight and decide to go after easier to predict snacks.
The Japanese researchers somewhat capture this oscillating type of flight with their plastic-winged flyer, but Dudley argued that the differences between the bot and a real butterfly are so great as to invalidate the biological lessons the researchers try to draw.
"There is nothing fundamentally wrong with this approach but it severely limits any claims to the biology," Dudley said.
Posted: 19 May 2010 11:58 AM PDT
After centuries of speculation, biologists have documented one way a strange group of octopus-like creatures use their seashell-shaped cases.
Female argonauts, a group of four species that are close cousins of octopuses, grow delicate white shell-like cases. Biologists have found argonauts with air bubbles in their cases, and now it turns out the animals use the trapped air to float at a comfortable depth, says Julian Finn of Museum Victoria in Melbourne, Australia.
In the first reports from scuba observations of wild argonauts, Finn maneuvered Argonauta argo females so air escaped from their cases. The animals flailed as if struggling to maintain their orientation and quickly jetted to the water surface.
Once at the surface, argonauts rocked their cases and took on air, he says. Then they positioned body parts to seal in some of the air and jetted downward, leaving behind a trail of bubbles.
When the argonauts stopped several meters below the surface, water pressure compressed the remaining air inside the case enough that it counteracted the animals' weight, leaving the argonauts floating neutrally buoyant at a chosen depth.
"Argonauts are fantastic animals to dive with," Finn says, though he does acknowledge that "when they really got going, I couldn't keep up with them."
People have mused about the function of argonauts' striking shell-like structures at least since Aristotle suggested that the animals sail or row them like boats.
Argonauts in the wild aren't easy to find, and previous studies of captive argonauts, which raised the possibility that bubbles were bad for the animals, may have been muddled by the effects of keeping the creatures in aquaria, say Finn and Mark Norman, also of the Museum Victoria. Those tanks were probably too shallow to allow biologists to see the animals' full behavior, the researchers say in their new analysis, posted online in Proceedings of the Royal Society B the week of May 17.
The idea that argonauts use their shells for buoyancy sounds plausible, says cephalopod biologist Michael Vecchione, a National Oceanic and Atmospheric Administration scientist based at the Smithsonian Institution in Washington, D.C. "I wonder how it would function during a storm at sea — and maybe it doesn't," he says.
Bubble trapping, however, may not be the only function of the shell-like case, he says. Female argonauts tuck masses of tiny eggs into spare space in the structure, Vecchione notes, much as bottom-dwelling octopuses protect their eggs in rock crevices.
Only female argonauts grow the shell-like structures, but males have very different bodies, presumably with different buoyancy issues. Males grow to about the size of the eye of a full-grown female and mate by sacrificing a detachable arm specialized for one-time delivery of sperm. Biologists at first mistakenly classified the remnant male arms as some kind of parasite that occasionally infected females' encased body.
Image: Julian Finn, Museum Victoria
Posted: 18 May 2010 03:33 PM PDT
The eruption of Mount St. Helens on May 18, 1980 has a special place in the evolution of our scientific understanding of volcanoes. Though it won't go down in the record books as the biggest, longest or deadliest eruption, it is one of the best-studied eruptions in history and the only major volcanic explosion in the continental United States since geologists and seismologists became equipped with modern technology to analyze such an event.
In the three decades since the eruption, the mountain has been an incredible place for scientists to study how life recovers from a catastrophe and recolonizes the landscape. Some of this can be seen in the time-lapse video above, which combines photo-like images from the Landsat series of satellites, run by the USGS and NASA, from 1984 through 2009. Prior to 1984, the Landsat satellites didn't have the ability to see blue wavelengths of light, and consequently images appear red, such as the ones below of the mountain before the eruption in 1979 and shortly after in 1980.
The area around the mountain was devastated by the collapse of the northern flank of the mountain in what amounted to one of the largest landslides ever recorded, which buried 24 square miles of land under as much as 600 feet of debris. The nine-hour eruption blew 520 million tons of ash over 230 square miles and knocked down 14 billion board feet of timber. Fifty-seven people died, including one geologist, and more than $1 billion in damage (1980 dollars) was done, making it the most destructive eruption in U.S. history. Video of a few minutes of the eruption can be seen below.
In the time-lapse above, you will first notice some recovery in the northwestern part of the blast zone, away from the volcano. Then the area around Spirit Lake becomes greener in the late 1990s. In the most recent images, the only area that still appears to be desolate is known as Pumice Plain. Research on the ground has found the first signs of life in recent years as flowers, insects and small animals have begun to reinhabit the plain. But these changes can't yet be seen from space.
Videos: Fernando Cardoso, Wired.com
Posted: 18 May 2010 12:03 PM PDT
The cable holding a model of Foucault's pendulum snapped last month at the Musée des Arts et Métiers in Paris, sending the 60-pound ball crashing to the ground. It was permanently dented in the fall.
Léon Foucault's 1851 experiment remains a mesmerizing evidence that the Earth does, in fact, rotate. Scientists were aware of this, but the fact that the pendulum swings through many degrees of a circle over the course of a day provides tangible proof that we are on a planet spinning in space. (The actual number of degrees that the Earth rotates underneath the pendulum is equal to the Earth's rotation rate multiplied by the sine of the pendulum's latitude; a Foucault's pendulum installed at the poles would move through 360 degrees, while in Paris, only three-quarters of a revolution (270 degrees) occurs in a 24-hour period.)
The Umberto Eco novel, Foucault's Pendulum, made the mid-19th-century physics demonstration famous. The novel even opens at the Musée des Arts et Métiers. The pendulum played a key role in the high-literary conspiracy involving the Knights Templar at the heart of the novel.
Photo: Graham Chandler/Flickr
Posted: 18 May 2010 10:42 AM PDT
Elderly people who care for a spouse who has dementia are at increased risk of developing dementia themselves, a study finds. The stress of attending to a mentally incapacitated spouse may somehow contribute to the added risk, scientists report in the May Journal of the American Geriatrics Society.
Previous studies have shown that chronic stress leads to increased levels of the hormone cortisol in the body, which can suppress immunity, says study co-author Peter Rabins, a psychiatrist at Johns Hopkins School of Medicine in Baltimore who teamed with researchers at Utah State University in Logan to do this study. "It's long been thought that this might have adverse outcomes psychologically and physiologically."
Taking care of a spouse with dementia takes a toll in other ways as well, Rabins says. "Caregivers often complain that they lose their friends," he says, because they don't have time to socialize. But the biological mechanisms that might link these challenges to heightened dementia risk remain unclear.
In the new study, the researchers assessed the mental status of 1,221 Utah couples who had agreed to be part of a community-wide health study that started in 1995. The men averaged age 76 and the women 73 at that point, and 95 percent had been married for more than 20 years. Researchers tracked these couples' mental status with up to four exams over the next decade with a median followup of 3.3 years. No participants in this analysis had dementia at the start.
During the followup years, 229 people found themselves caring for a spouse with dementia. The caregivers were six times more likely to develop dementia themselves compared with people whose spouses did not develop dementia. The researchers accounted for differences between the couples in age, education, socioeconomic status and the presence of variants in the APOE gene that can increase risk of Alzheimer's disease.
While this is the first study to look at actual dementia risk in spousal caregivers, other research has documented an array of physical and mental problems associated with caregiving. These include depression, sleep problems, less exercise and unhealthy diet, says Peter Vitaliano, a psychologist at the University of Washington School of Medicine in Seattle, writing in the same issue of the Journal of the American Geriatrics Society. All these conditions may be risk factors for dementia, he notes.
In the new study, the authors point out that some of the increased risk of dementia in caregivers may be due to shared environment. The couples had been married on average for 49 years upon enrollment in the study. But what those shared environmental risk factors might be remains unknown.
One other possible contributor to this dementia risk could be the tendency of people who are prone to distress or mental illness to find and marry one other, Rabins says.
Bruce McEwen, a neuroscientist at Rockefeller University in New York City, says that in the future researchers might do well to investigate whether caregiver spouses who have less social support — or who are just more isolated — might be at the most risk.
Photo: Up Your Ego/Flickr
Posted: 17 May 2010 05:36 PM PDT
The judge in a recent Brooklyn case in which brain scan evidence was offered has delivered an opinion on why he ultimately excluded the fMRI data.
In Judge Robert H. Miller's written opinion, obtained by Wired.com, he decided that under the Frye test, which is slightly different from the Daubert standard used in federal court, lie detection evidence contravenes a jury's key right to decide the credibility of witnesses.
The plaintiff in Miller's case had attempted to establish a key witness was telling the truth.
"Since credibility is a matter solely for the jury and is clearly within the ken of the jury, plaintiff has failed to meet this key prong of the Frye test and no other inquiry is required," Miller wrote. "However, even a cursory review of the scientific literature demonstrates that the plaintiff is unable to establish that the use of the fMRI test to determine truthfulness or deceit is accepted as reliable within the relevant scientific community."
The rest of the short opinion is embedded below.
Image: flickr/Katherine Kenney
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