- Congress, Obama Take Sudden Interest in Synthetic Biology
- Video: Designing Bridges to Be Drivable After Quakes
- The Science of Horror-Movie Screams
- Origin of Milky Way Clouds Revealed
- Video: The Butterfly Effect on the Sun’s Surface
- Black Hole Found in Unexpected Place
- New Flu Vaccines Could Protect Against All Strains
- Video: Kamikaze Comet Dives Into Sun’s Lower Atmosphere
- Planetary Bullies Make Astronomers Rethink the Habitable Zone
- Testosterone Makes People Suspicious of One Another
Posted: 27 May 2010 01:31 PM PDT
Congress explicitly took up the subject of synthetic biology for the first time Thursday during a hastily convened hearing of the House Energy and Commerce Committee.
The Wired crowd has been talking about how to engineer biological machines for years, but Craig Venter's announcement last week that he's created a synthetic cell has drawn the attention of the very highest levels of government.
The hearing came shortly after President Barack Obama ordered a six-month review of synthetic biology by a panel of scientific stars.
The House committee members seemed primarily interested in the potential of synthetic biology to create micro-organisms that could effectively produce hydrocarbons that could be used to power the nation's transportation system.
"Synthetic biology also has the potential to reduce our dependence on oil and to address
The committee heard testimony from an excellent panel of scientists composed of Venter himself, Berkeley's Jay Keasling, Stanford's Drew Endy, and the director of the National Institute of Allergy and Infectious Diseases, Anthony Fauci.
Committee members did not seem overwhelmingly familiar with the state of the science, generally reading clunkily from prepared statements. The event did not have any of the sharp give-and-takes between representatives and panelists that they sometimes do.
In fact, the hearing was technically an oversight task, but it played out closer to a gee-whiz commercial for the new firms that are trying to commercialize the technology. Venter, Keasling and Endy all have ties to companies trying to make money from synthetic biological techniques.
Keasling made the smoothest transition from his scientific work, coming up with a way to produce the anti-malarial drug artemisinin in yeast, which could substantially reduce the cost of its distribution, to his sales pitch.
"Fortuitously, artemisinin is a hydrocarbon, a fundamental building block for fuel. We are
Only one witness, Gregory Kaebnick, a bioethicist at the Hastings Center, a nonprofit that studies the ethics of biotechnology, could be said to be an outside observer of the synthetic biology industry.
"I was the only one on the panel who didn't have a vested stake in it one way or the other. I think that's probably a mistake," Kaebnick told Wired.com. "The president's panel will take it up, and they'll probably bring in more perspectives."
Image: Venter's blue synthetic cells
Posted: 27 May 2010 08:37 AM PDT
RICHMOND, California — Sure, earthquake engineers can now make bridges safe during even the biggest earthquakes, but they're still rendered unusable in the key hours after a temblor.
Now, they have a new goal: building bridges that cars can keep driving over in the immediate wake of a quake. And they unveiled a set of technologies Wednesday at the Pacific Earthquake Engineering Research Center that may be able to make cities more resilient in the wake of a disaster.
"Can we design bridges to not just be safe but remain open after an earthquake?" asked Stephen Mahin, the director of the center.
Recent earthquakes in China and Haiti showed how vulnerable poorly designed buildings are, but in the rich countries around the quake-prone Pacific Rim like the United States and Japan, earthquake engineers have solutions to the basic architectural problem of keeping a building standing under extreme forces. Seismic isolators allow buildings to slide around a bit as a way to dissipate the energy of an earthquake. New ways of making and reinforcing concrete keep columns from cracking.
Now, though, engineers want to keep buildings not only intact, but functional. In the video above, engineer Kenneth Ogorzalek, a graduate student in civil engineering at the University of California at Berkeley, built a test railroad bridge complete with tracks ona shake table. To simulate the weight of the real thing, he used every scrap of lead the engineering center could muster. Thehttp://blog-admin.wired.com/wiredscience/wp-admin/edit.phpn, the movements caused by several earthquakes like 1989's Loma Prieta quake were re-enacted by a series of actuators located underneath the floor of the experiment area.
You can see two systems at work in the video. First, there is a series of a new type of isolator called a "triple pendulum." The isolator reduces the amount of force the bridge experiences by slowing down its acceleration. The triple pendulums are like nested bearings, so the bridge can respond appropriately to different-size quakes.
The other innovation is a way of coupling the sections of the bridge together. The idea is to make sure that even if the segments of a bridge move a little after a quake, they still form a straight line that can be used. The Segmental Displacement Control Isolation System was tested for the very first time Wednesday.
The new technology probably won't be used for years, but Mahin said that his group was "doing research now to support what policymakers will want to do in 10 or 15 years."
Posted: 26 May 2010 01:45 PM PDT
As horror-flick titles go, Night of the Living Chaos and Rosemary's Nonlinearity aren't the catchiest. But filmmakers know that chaos — the mathematical kind — is scary. Now scientists know it too.
Filmmakers use chaotic, unpredictable sounds to evoke particular emotions, say researchers who have assessed screams and other outbursts from more than 100 movies. The new findings, reported May 25 in Biology Letters, come as no surprise, but they do highlight an emerging if little-known area of study, says cognitive biologist W. Tecumseh Fitch of the University of Vienna in Austria, who was not involved in the study.
"The classic example would be a screaming baby on an airplane," says Fitch, "the kind you can't ignore and makes your life hell."
Cries are harder to ignore when they become irregular and chaotic, recent research suggests. Scientists think that these noises, uttered or roared when an animal is really worked up, have a crucial role in communication: They frantically demand attention.
By exploring the use of such dissonant, harsh sounds in film, scientists hope to get a better understanding of how fear is expressed, says study co-author Daniel Blumstein of the University of California, Los Angeles.
"Potentially, there are universal rules of arousal and ways to communicate fear," says Blumstein, who typically studies screams in marmots, not starlets.
Blumstein and his co-authors acoustically analyzed 30-second cuts from more than 100 movies representing a broad array of genres. The movies included titles such as Aliens, Goldfinger, Annie Hall, The Green Mile, Slumdog Millionaire, Titanic, Carrie, The Shining and Black Hawk Down.
Not unexpectedly, the horror films had a lot of harsh and atonal screams. Dramatic films had sound tracks with fewer screams but a lot of abrupt changes in frequency. And adventure films, it turns out, had a surprising number of harsh male screams.
"Screams are basically chaos," Fitch says.
Filmmakers have long been deliberately distorting sounds for dramatic effect, says musicologist James Wierzbicki of the University of Sydney. In Hitchcock's classic The Birds, the only true avian sounds are heard near the beginning of the movie, in a pet shop. The calls of the demented, attacking birds were all electronically generated.
A true, harsh scream "is not a trivial thing to do," Fitch says. In fact, capturing a realistic, blood-curdling cry is so difficult that filmmakers have used the very same one, now found on many websites, in more than 200 movies. Known as the Wilhelm scream, it is named for the character who unleashed it in the 1953 western The Charge at Feather River.
Posted: 26 May 2010 11:03 AM PDT
Mysterious clouds of gas hovering above the plane of the Milky Way may be the fractured remnants of superbubbles blown by stellar winds and exploding stars.
"There's a fundamental, interesting connection between gas far away from the Milky Way and the amount of star formation below it in the galactic plane," F. Jay Lockman of the National Radio Astronomy Observatory told Wired Science in a phone interview. The results could provide insight into how heavy elements traverse the galaxy and get incorporated into later generations of stars, planets and, perhaps, life.
The bulk of the matter in the Milky Way, including stars, hot star-forming regions and the gas and dust between stars called the interstellar medium, lies in a relatively flat disk called the galactic plane.
"It's a flattened system, kind of like a pierogi," Lockman said today at the American Astronomical Society in Miami.
The Milky Way also has a gaseous halo that extends above and below the galactic pastry. For years, astronomers expected the density of that gas to get thinner as it got farther from the Milky Way, the way Earth's atmosphere thins out at high altitudes. But earlier observations Lockman made at the Green Bank Telescope in West Virginia showed dense clouds hundreds of times more massive than the sun floating between the disk and the halo, hundreds to thousands of light-years above the galactic plane.
"This turned my whole conception of what was going on upside down," he said. "It's very much like seeing, all your life, a distant hillside that's covered in green fuzz. Then one day you get a pair of binoculars and you look and say, 'My God, there's trees!'"
To investigate these clouds further, Lockman and colleagues used data from the Parkes Observatory radio telescope in Australia of two regions of the Milky Way, one on either side of the galactic center from Earth's point of view.
Individual clouds in both regions looked about the same, Lockman said — on average they were 600 times the mass of the sun and spanned 30 to 40 light-years. But the region on the "northern" side, to the left of the galactic center, had three times as many clouds as the "southern" region.
"I thought we would see a difference between north and south, but I thought it would be pretty subtle," Lockman said. "It's not subtle at all."
It turned out the northern region included part of the bar of the Milky Way. A new survey of hydrogen gas in the galaxy that was presented at the same meeting confirmed this region is an active stellar nursery.
"At the end of the galactic bar emanating from the galactic center, there is a huge complex of star forming regions," said Tom Bania of Boston University.
The southern region, by contrast, fell between two spiral arms, "not particularly associated with anything at all," Lockman said.
Lockman and his colleagues concluded that the gas clouds were blown away from the galactic plane by stellar winds from these intense star-forming regions. When the more massive of these stars die, they explode as supernovas, blowing enormous bubbles of gas "like supersonic lava lamps," Lockman said. These bubbles pop like soap after they rise, leaving behind the mysterious clouds.
"There are still lots of questions," Lockman said. "But I think we've finally solved the question of their origin."
These clouds could also be responsible for transporting heavy elements around the galaxy. All elements heavier than hydrogen and helium are built in nuclear reactions inside stars, and are blown off into the interstellar medium when stars explode as supernovas. That material later condenses into new, metal-rich stars — and ultimately planets.
"When our galaxy formed, planets like the Earth could not form," Bania said. "Put the Earth in a blender and you've got silicon, magnesium, the stuff that's formed in supernovas."
If the clouds are in fact the remnants of supernova bubbles, Lockman said, then "it's quite possible that these clouds as they fall back to the Milky Way are the way that metals get mixed in through the disk, and this controls the overall evolution of the interstellar medium and the next generation of stars."
Image: Bill Saxton, NRAO/AUI/NSF
Posted: 25 May 2010 04:11 PM PDT
New data from NASA's Solar Dynamics Observatory shows that on the sun, little changes can have big consequences. High-resolution images of layers of the sun's surface show how small flares can trigger larger flares and coronal mass ejections hundreds of thousands of miles away.
"We are in essence watching the butterfly effect on the sun," said W. Dean Pesnell of NASA's Goddard Spaceflight Center at a press briefing at the American Astronomical Society meeting in Miami on May 25.
The images were taken with SDO's Atmospheric Imaging Assembly, which takes images of the full disk of the sun at eight different temperatures from 10,000 to 36 million degrees Fahrenheit. They show a small flare in the right part of the screen, which sets off a magnetic instability that cascades across the surface of the sun at hundreds of thousands to millions of miles per hour. This wave builds as it travels, culminating in a flare that triggers a large loop of hot, charged plasma at the top left of the sun's disk.
"For the first time, we're beginning to be able to see these connections," said Alan Title of the Lockheed Martin Advanced Technology Center. "We still don't know how far these cascades go. AIA is showing us that these cascades in fact exist."
Video: SDO/NASA/AIA consortium
Posted: 25 May 2010 04:08 PM PDT
Detailed Hubble images reveal a single supermassive black hole wandering away from its host galaxy's center where it belongs. The misplaced black hole is probably the result of a merger between two smaller black holes, but could also have been pushed by a jet of matter extending from the galaxy's core.
Nearly every galaxy has a supermassive black hole — millions to billions of times more massive than our sun — nestled in its center. Astronomers think galaxies frequently collide and merge to make bigger galaxies. When the galaxies merge, the theory goes, so do their black holes. Previous observations have caught such mergers in the act — but always when the black holes were thousands of light years apart, before they merged.
"This is the first time we have seen the merger after it has happened," said Eric Perlman of the Florida Institute of Technology at a press conference at the American Astronomical Society meeting in Miami on May 25. The results will also appear in a paper in an upcoming issue of Astrophysical Journal Letters.
Perlman and colleagues analyzed images of the largest local galaxy, M87, taken with the Hubble Space Telescope's highest-resolution camera, the Advanced Camera for Surveys. Black holes by nature are invisible, but the mass of gas and dust that heats up as it falls onto the guzzling giant, called an active galactic nucleus, can glow brightly and give away its location. The team located this bright nucleus, and found that it was 22 light-years away from the galaxy's center.
"The supermassive black hole is not where it is expected to be," said Daniel Batcheldor of the Florida Institute of Technology at the same press conference, but it's "a very slight, subtle offset."
The researchers came up with four possible explanations for the wayward black hole. First they thought it could be one of a pair of black holes spiraling in toward a merger. But the second black hole, which would have to be around the same size as the first, was nowhere to be found.
"It would be very very difficult for nature to mask such a large mass in that galaxy," Batcheldor said.
The researchers also dismissed the idea that the black hole was nudged aside by the combined gravitational tugs of other galaxies and globular clusters in M87's immediate neighborhood, the Virgo Cluster. All that mass would be enough to move the black hole just 0.3 light-years.
A more realistic possibility is the jet of material extending more than 5,000 light years from M87 could have pushed the black hole away from the center of the galaxy. The jet is massive enough to provide only a soft push on galactic scales, but it could be sufficient to move the black hole if the jet were 100 million years old or older. The jet would also have had to be much more massive in the past for this scenario to work, Batcheldor said.
"We don't rule this out as an offset mechanism because we do not know the history of accretion in M87 very well," he said. "It's very possible that in the past … there was more jet power that could have produced the offset."
The most likely solution is that the black hole is the product of a merger between two smaller black holes. Theory states that when two black holes merge, they emit gravitational waves that can give the resulting large black hole a "kick" of momentum, sending it flying through the galaxy. Because many galaxies are similar to M87, wandering black holes could be common in the universe.
"We expect there to be displaced black holes in the universe due to gravitational wave recoil," commented Julie Comerford of the University of California, Berkeley, who was not involved in the study. "This work shows that the black hole in M87 is a compelling candidate for a recoiling black hole."
Regardless of how M87's black hole left home, Batcheldor said, astronomers should rethink how black holes and galaxies normally fit together.
"It could well be that we need to shift the standard supermassive-black-hole paradigm that black holes are at the centers of galaxies, and revise it slightly to say that they're near the centers of galaxies," he said.
Posted: 25 May 2010 02:55 PM PDT
A new vaccine may be able to provide some protection against all strains of influenza.
Current immunizations create antibodies that target a specific piece of a molecule on the surface of the virus that researchers call its "head." That piece of the hemaglutinin protein evolves very quickly, which is why you have to get a different flu shot each year as new types of flu develop.
The next-generation vaccine causes antibodies to go after a piece of the hemaglutinin that changes less often and that is present in many influenza strains. Researchers are calling them "headless HA" vaccines, and they could be the key to a universal flu shot.
Mice immunized with the new vaccine survived a flu that killed unprotected mice.
"Our results suggest that the response induced by headless HA vaccines is sufficiently potent to warrant their further development toward a universal influenza virus vaccine," Peter Palese of Mt. Sinai Medical School, who led the effort, said in a press release. "Through further development and testing, we predict that a single immunization with a headless HA vaccine will offer effective protection through several influenza epidemics."
The early research appears in the new open access journal mBio. In a commentary accompanying the paper, two Italian researchers suggested that many other types of disease that currently require multiple vaccines may soon have broader solutions.
"Is influenza the only disease that warrants approaches for universal vaccines? Clearly it is not," wrote Antonio Cassone of the Instituto Superiore di Sanità in Rome and Rino Rappuoli of Novartis Vaccines and Diagnostics.
Posted: 24 May 2010 05:03 PM PDT
NASA's twin sun-observing spacecraft tracked a comet further than ever before as it dove into the sun.
The video above is a compilation of images from the two STEREO spacecraft that orbit with the Earth, one ahead of the planet and the other behind. The configuration allows for nearly full, continuous coverage of the sun, increasing the chance of witnessing something like the kamikaze comet that they spotted in March.
Seeing comets and other small objects approach the sun is difficult because the objects are overwhelmed by the sun's brightness. Scientists were able to track this one closer to the sun than ever, before it it burned up in the sun's lower atmosphere.
"We believe this is the first time a comet has been tracked in 3-D space this low down in the solar corona," Claire Raftery of the University of California, Berkeley said in a press release. The images were presented at the American Astronomical Meeting in Miami May 24.
Posted: 24 May 2010 03:22 PM PDT
Exoplanet orbits that seem just right for life could be bent out of shape by pushy neighbors. New simulations of extrasolar planetary systems may mean the definition of "habitable" planets needs to be completely overhauled.
When astronomers talk about the "habitable zone," they mean the shell around a star where the temperatures are right for liquid water. Any closer, and oceans will boil. Any farther, and the planet will freeze. But this definition assumes that most planets have roughly circular orbits, like the Earth and most other planets in the solar system.
"What we know from studying exoplanets is that that is definitely not the rule," said Rory Barnes of the University of Washington at the meeting of the American Astronomical Society in Miami. Many of the 454 exoplanets discovered to date have highly elliptical orbits, meaning the planets are not always the same distance from their parent star. Thanks to this uneven geometry, the planet spends more time closer to its star, which tends to make for warmer planets.
Adding another planet, especially a bullying Jupiter-sized planet, can mess with orbits and make a once-hospitable planet move in and out of the habitable zone over time. Using computer simulations of several hypothetical planetary systems, Barnes showed that a giant neighbor can pull an Earth-like planet's orbit like a rubber band, shifting it from circular to elliptical and back to circular again in as little as a few thousand years.
"It's a very stable, repetitive process," Barnes said.
The Earth's orbit actually does feel similar nudges from Jupiter, known as Milankovitch Cycles. But luckily for us, these orbital shape shifts are subtle.
Barnes' simulations predicted more-dire consequences for extrasolar planets near the edge of their habitable zones, though. If the planet is on the cooler edge of the habitable zone, it could go through cycles of freezing and thawing. If it's on the warmer side, the temperature could fluctuate from comfy to boiling from one millennium to the next.
"The inner edge is much more dangerous," Barnes said. All the water could boil off and be lost forever, or the warming planet could experience a "runaway greenhouse" effect and end up a scorched wasteland like Venus.
But it's not all bad news. Barnes suggests that some planets we might dismiss as snowballs could just be going through an eccentric phase.
"Our own Earth has gone through stages of glaciation — we call them snowball Earth phases — and we managed to pull out of it," he said. "On a planet like that, on the outer edge, you will have reservoirs of life, and there will be habitats that will persist."
For planets around dim, low-mass stars, which have to be especially close to be in the habitable zones, neighboring giant planets could wreak havoc with the length of the day, and the gravitational pull could cause cycles of volcanic activity and earthquakes interspersed with relative calm.
"These are fascinating worlds to think about," Barnes said. "It will do lots of interesting things as far as how climates might evolve and how evolution might happen on such a planet."
The results suggest that the current definition of "habitable zone" may be too simplistic. Astronomers may have to consider the whole family of exoplanets in a system before determining if one is habitable or not.
"One of the things that this new work is emphasizing is that one needs to be very careful about defining habitability," commented Phil Armitage of the University of Colorado, Boulder. "Those ideas about terrestrial planet formation and habitability of terrestrial planets will need to be re-evaluated from scratch."
Posted: 24 May 2010 02:47 PM PDT
Testosterone is linked to aggression, competition and social status. Now scientists have found that the hormone also reduces naive individuals' confidence in others.
"Testosterone reduces trust just enough to make people vigilant and careful," said psychologist Jack van Honk of Utrecht University in the Netherlands, who led the study published May 24 in Proceedings of the National Academy of Sciences.
In the study, a few dozen females received half a milligram of testosterone under the tongue — enough to increase hormone levels tenfold. The women viewed pictures of faces and judged how trustworthy they looked. The drug decreased ratings by about half, and the effect was only strong for females who are normally easily fooled.
Van Honk speculates that the effect does not occur in cautious individuals, because the hormone would make them so paranoid that they would become socially disabled.
"I think that people are going to see that testosterone has beneficial effects on social behaviors and carries properties that might be important for applications in certain psychiatric diseases, one of them being social anxiety disorder," he said
"It's interesting work that fits nicely with recent work suggesting that testosterone influences social motivation and perception," said Pranjal Mehta, a psychologist at Columbia University who was not involved in the study. Future studies should test whether testosterone decreases trust in all individuals in more competitive situations, he said. "It's absolutely critical to test the effect of the hormone in real-world social contexts," he said.
Previous studies have found that oxytocin, a hormone involved in bonding, increases faith in others. The two hormones together may keep trust at an optimal level, van Honk said. In future studies, he would like to determine which brain circuits regulate trust through these hormones.
Image: flickr/an untrained eye
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