Could a Computer One Day Rewire Itself? New Nanomaterial 'Steers' Electric Currents in Multiple Dimensions
|12:11:12 AM, Monday, October 17, 2011|
"Scientists at Northwestern University have developed a new nanomaterial that can "steer" electrical currents. The development could lead to a computer that can simply reconfigure its internal wiring and become an entirely different device, based on changing needs.
As electronic devices are built smaller and smaller, the materials from which the circuits are constructed begin to lose their properties and begin to be controlled by quantum mechanical phenomena. Reaching this physical barrier, many scientists have begun building circuits into multiple dimensions, such as stacking components on top of one another.
The Northwestern team has taken a fundamentally different approach. They have made reconfigurable electronic materials: materials that can rearrange themselves to meet different computational needs at different times.
"Our new steering technology allows use to direct current flow through a piece of continuous material," said Bartosz A. Grzybowski, who led the research. "Like redirecting a river, streams of electrons can be steered in multiple directions through a block of the material -- even multiple streams flowing in opposing directions at the same time."
Grzybowski is professor of chemical and biological engineering in the McCormick School of Engineering and Applied Science and professor of chemistry in the Weinberg College of Arts and Sciences.
The Northwestern material combines different aspects of silicon- and polymer-based electronics to create a new classification of electronic materials: nanoparticle-based electronics.
The study, in which the authors report making preliminary electronic components with the hybrid material, will be published online Oct. 16 by the journal Nature Nanotechnology. The research also will be published as the cover story in the November print issue of the journal..."
New Metal-Eating Bacteria Found on Titanic
|3:23:18 AM, Saturday, October 15, 2011|
"Bacteria scooped from the wreckage of the Titanic almost 20 years ago have been confirmed as a new species in the December issue of a microbiology journal.
While new scientific discoveries are usually heralded as joyous news, this discovery is bittersweet.
The bacteria, found on the ship's "rusticles" (rust formations that look like icicles), are eating the Titanic.
The strain, dubbed Halomonas titanicae, was initially designated BH1T in honor of the researchers who discovered it, then-graduate student Bhavleen Kaur and Dr. Henrietta Mann at Dalhousie University in Halifax, Canada.
The researchers tested the bacteria to see whether it was "good bacteria" or "bad bacteria," according to the school's website.
Let's just say the bug has an appetite for destruction.
"The BH1 cells stuck to the surface of these [small metal tags] and eventually destroyed the metal. So we knew we had a bad bacteria,” Mann is quoted as saying on the Dalhousie University website.
"In 1995, I was predicting that Titanic had another 30 years," said Mann, who still works at the university, according to CBS News. "But I think it's deteriorating much faster than that now ... Eventually there will be nothing left but a rust stain," she is quoted as saying.
The metal-eating bug presents a dilemma for scientists.
"Letting it proceed with its deterioration is also a learning process," said Kaur, who now works with the Ontario Science Centre, according to National Geographic. "If we stop and preserve it, then we stop the process of degradation," Kaur is quoted as saying.
The findings were published in the December 8 issue of the International Journal of Systematic and Evolutionary Microbiology.
The Titanic, heralded in its day as the largest passenger ship in the world, sank on its maiden voyage in 1912, killing more than 1,500 people. The wreckage was found in 1985 by an expedition team more than 2 miles deep in the Atlantic Ocean."
Scientists Solve Puzzle of Black Death’s DNA
|2:01:39 AM, Saturday, October 15, 2011|
"After the Black Death reached London in 1348, about 2,400 people were buried in East Smithfield, near the Tower of London, in a cemetery that had been prepared for the plague’s arrival. From the teeth of four of those victims, researchers have now reconstructed the full DNA of a microbe that within five years felled one-third to one-half of the population of Western Europe.
The bacterium that causes plague, Yersinia pestis, is still highly virulent today but has different symptoms, leading some historians to doubt that it was the agent of the Black Death.
Those doubts were laid to rest last year by detection of the bacterium’s DNA in plague victims from mass graves across Europe. With the full genome now in hand, the researchers hope to recreate the microbe itself so as to understand what made the Black Death outbreak so deadly.
So far, the evidence points more toward the conditions of the time than to properties of the bacterium itself. The genome recovered from the East Smithfield victims is remarkably similar to that of the present-day bacterium, says the research team, led by Kirsten I. Bos of McMaster University in Ontario and Johannes Krause of the University of Tübingen in Germany.
This is the first time the genome of an ancient pathogen has been reconstructed, opening the way to tracking other ancient epidemics and how their microbes adapted to human hosts.
The bacterium’s genome consists of a single chromosome, about 4.6 million DNA units long, and three small rings of DNA called plasmids. In the 660 years since the Black Death struck, only 97 of these DNA units have changed and only a dozen of these changes occur in genes and therefore would affect the organism’s physical properties, the researchers report in Wednesday’s issue of the journal Nature. Dr. Krause and others reported the DNA sequence of one of the plasmids in August. The changes in the genome will be studied one by one to see how each affects the microbe’s virulence.
The researchers hope eventually to modify a living plague bacterium so that its genome is identical to that of the agent of the Black Death. Such a microbe could be handled only in special secure facilities. But even if it did infect a person, the bacterium would be susceptible to antibiotics, like its living descendants, said Hendrik Poinar of McMaster University, a team member.
If the microbe’s genome is so little changed, the deadliness of the Black Death may reflect the condition of its medieval victims. Harsh as the economic stresses assailing Europe today may be, they are a breeze compared with problems in the mid-14th century. The climate was cooling, heavy rains rotted out crops and caused frequent famines, and the Hundred Years’ War began in 1337. People were probably already suffering from malnutrition and other diseases when the plague arrived like the fourth horseman of the apocalypse. “People honestly thought it was the end of the world,” Ms. Bos said..."
What’s the Most Important Lesson You Learned from a Teacher?
|3:08:10 AM, Wednesday, October 12, 2011|
"Five mornings a week, Keith gets up before dawn, puts on one of his geekiest bow ties (think Space Invaders, DNA helices, and daVinci’s Vitruvian Man), and drives half an hour down the freeway to teach teenagers about the wonders of science and the rigors of the scientific method at a local high school.
It’s a demanding life with little downtime. Keith’s evenings and weekends are often consumed by lesson planning and other school-related activities, but he’s perpetually stressed out about whether he’s doing enough for his kids. With his Ph.D. in chemical engineering from Berkeley — one of the top five such programs in the country — he could triple his schoolteacher’s salary by taking a job as a bench scientist at DuPont or Exxon-Mobil, as many of his fellow Berkeley grads have done.
But Keith has a passion for teaching. He lives for those moments when he can help a student make sense of the world through science. (He’s also my husband.)
People who make the career choices that Keith did don’t get a lot of respect these days. In endless discussions of “the crisis in education,” teachers are routinely described as burned out, bumbling, underqualified, and unfit — particularly if they belong to a union. In his new book Class Warfare, aspiring education reformer Steven Brill calls school districts “the most lavishly funded and entrenched bureaucracies in America… supported by an interest group — the teachers’ unions — which [have] money and playbooks every bit as effective in thwarting the public interest as Big Oil, the NRA, or Big Tobacco.”
It’s as if we’ve collectively decided that anyone who devotes his life to standing at the head of a classroom, when salaries are so low and school budgets are being slashed, can’t be that smart after all — an insidious legacy of the era when teaching was one of the few acceptable occupations for women.
Conversely, teachers who are clearly effective are portrayed as exceptional: self-sacrificing superheroes who single-handedly boost their students’ scores on standardized tests with little regard for such mundane concerns as a living wage, job security, health benefits, and adequate class resources. Meanwhile, billionaire venture capitalists like PayPal founder Peter Thiel advise young entrepreneurs to drop out of college altogether as a “bad investment” and get down to the serious business of raising capital in their teens — as if a wide-ranging education was just another expendable item on a spreadsheet.
While reading this moving NPR story about a neurosurgeon who phoned his high-school science teacher to express his gratitude after performing a tricky operation, it struck me how rarely we hear from accomplished people about the debt they owe to their teachers. The words of a true teacher stay with us a long time, offering wise counsel in a confusing world and a potent inoculation against foolishness. Yet we rarely get to thank them explicitly. Perhaps only in mid-life, we realize that the career path we chose was set, at least in part, by the recognition, praise, or clarifying criticism of a respected teacher when we were young.
In that spirit, I’ve asked some of the brightest folks I know in science and media to answer this simple question: What’s the most important lesson you learned from a teacher?
I’m delighted to report that a wide range of writers and thinkers were eager to share their stories. Among those who pay tribute to their most influential teachers here are two bestselling authors, Rebecca Skloot and Deborah Blum; the brilliant culture critic Mark Dery; award-winning science journalists David Dobbs, Amy Harmon, and Hillary Rosner; cognitive psychologist Uta Frith, the pioneer of autism research who translated Hans Asperger’s original paper; and several of the most perceptive and prolific bloggers around, including Maggie Koerth-Baker of BoingBoing, Geoff Manaugh of BLDGBLOG, and Ed Yong of Not Exactly Rocket Science. It turns out that by asking people that simple question, you open floodgates of memory and understanding.
If you feel inspired after reading these marvelous, charming, and occasionally terrifying tales from the classroom, please consider Googling up a memorable teacher and sending them an email to tell them what you’re up to now and express your appreciation. I guarantee that doing so will improve your day and profoundly touch the heart of someone who helped guide you into the world. Life is brief.
One of my favorite stories about a teacher’s enduring impact comes from Pulitzer prize-winning poet Gary Snyder, the real-life model for the hero of Jack Kerouac’s novel The Dharma Bums, and one of the first American students to study Zen in Japan. Snyder’s teacher there was a tough old monk who delivered his lengthy discourses on Buddhadharma in such a soft voice that his students strained to hear them, struggling to stay awake on their meditation cushions..."
World's Oldest Running Car Fetches $4.6 Million at Auction
|1:03:08 AM, Wednesday, October 12, 2011|
"The world's oldest running car, an 1884 De Dion Bouton Et Trapardoux Dos-A-Dos Steam Runabout, made history Friday, fetching $4.62 million at RM Auctions' Hershey, Pennsylvania event. Before a packed house, the 127-year-old ride quickly eclipsed its $500,000 starting bid.
By the time the dust had settled, the gavel fell at $4.2 million. The final price included a ten-percent buyer's premium. The crowd began applauding as soon as the car crept onto the stage and the enthusiasm didn't wane until well after the sale.
The Runabout had been in the same family for 81 years prior to the sale, and is one of six De Dion tricycles known to still exist. A total of 20 of the three-wheelers were built. When new, the trike had a top speed of 38 mph and a range of 20 miles on one tank of water. The vehicle that sold last night was the only car to show up for the world's first auto race, where it averaged 16 mph over a 20-mile course. Hop the jump for a press release."
Light-Attack Plane Seeks New Life In Navy
|2:27:06 AM, Tuesday, October 11, 2011|
"Lockheed Martin and Hawker-Beechcraft are considering pitching its AT-6B light-attack counterinsurgency plane for the upcoming Navy-led Combat Dragon II program, according to sources familiar with the effort.
The Navy recently shifted over $17 million into the Combat Dragon II program, designed to prove that a small, turboprop-driven aircraft can be used for "high end/special aviation" missions in Afghanistan.
The program was driven by the need coming out of from Central Command to have aircraft do close air support missions that larger fighters and bombers could not do, specifically in support of Naval Special Warfare units.
The Navy tried to fill that requirement through the Imminent Fury program, using the Brazilian-built Embraer Super Tucano. But that program fizzled out shortly before the planes headed out to Afghanistan for operational tests.
Combat Dragon II, which is set to kick off in Afghanistan by next spring, will use modified, Vietnam-era OV-10 Broncos, sources say. But the Lockheed Martin-Hawker Beechcraft team are pushing the Navy to include their plane in that mix.
While no decision has been made on whether to roll the AT-6B into Combat Dragon II, its inclusion could breath some new life into the program.
To date, the only firm commitment to buy a light-attack aircraft has come from the Afghan Ministry of Defense to support its fledgling air forces.
The Air Force was looking at the AT-6B, along with the Super Tucano, to build a fleet of aircraft specifically to train partner nations in counterinsurgency and counterterrorism operations. But to date, the Air Force has yet to formally solicit proposals from industry for that international training effort.
Moreover, Air Force leaders -- including Air Force Chief of Staff Gen. Norton Schwartz -- have said the service will never field a light-attack aircraft of its own, despite the fact the Joint Requirements Oversight Council and Joint Requirements Board validated the need for the plane, sources say.
But since the AT-6B already uses the same fire controls as the venerable A-10 Warthog, and that it can be fitted with key sensor and communication systems needed for counterinsurgency missions, makes the plane a good fit for the Navy or whoever needs a light-attack airplane, Lockheed Martin Business Development chief Bob Silva said."
Virus Hits US Drone Fleet: Report
|1:49:06 AM, Tuesday, October 11, 2011|
"A computer virus has hit the US Predator and Reaper drone fleet that Washington deploys to hunt down militants, logging the keystrokes of pilots remotely flying missions, Wired magazine reported.
The virus was first detected about two weeks ago by the military's Host-Based Security System, but it had not halted missions flown remotely over Afghanistan and other warzones from Nevada's Creech Air Force Base, Wired said Friday.
No classified information was believed to have been lost or sent outside the network, though the resilient virus resisted several attempts to remove it.
"We keep wiping it off, and it keeps coming back," a source familiar with the network infection told the US magazine. "We think it's benign. But we just don't know."
Military network security specialists said it remained unclear whether the virus was intentional and how far it had spread, but they were certain it had infected Creech's classified and unclassified machines. Secret data may thus have leaked out and reached someone outside military officials.
The US military does not hide its own drone flights in Libya or the war in Afghanistan, in contrast to the CIA's covert missions to take out Al-Qaeda extremists in Pakistan, Yemen and elsewhere. The drones have become a critical weapon of choice for the United States in fighting militants abroad..."
Huge New Dinosaur Trackway Found in U.S.
|11:49:03 PM, Monday, October 10, 2011|
"Fossilized tracks of dinosaurs "stomping in the mud" have been discovered in southwestern Arkansas, scientists say.
Spanning the length of two football fields, the footprints hint that a giant predator was a bit pigeon-toed.
Several species, including the eight-ton Acrocanthosaurus atokensis—one of the largest predators ever to walk Earth—and sauropods, or long-necked plant-eaters, left their footprints in the 120-million-year-old Cretaceous limestone.
At the time, Arkansas was a broad mud flat, similar to the hot, dry, and salty shores of the modern-day Persian Gulf—not a particularly "pleasant place," said team leader Stephen Boss, a geoscientist at the University of Arkansas in Fayetteville.
Predators like Acrocanthosaurus were likely attracted to the site by sauropods and other prey species, but "what the sauropods are doing out there, who knows?" Boss said.
Though found elsewhere in North America, dinosaur trackways are rare in the southern U.S., he said. Indeed, most people tend to think of dinosaurs dwelling in the "classic" western lands of Colorado and Utah.
"They don't think this is a place that dinosaurs once roamed, but it is—and here's the proof."
Dinosaur Tracks Reveal Pigeon-Toed Predator?
A private citizen recently found the tracks, which were possibly exposed after a rainstorm scoured away a thin layer of shale. The shape of the footprints and the age of the limestone leaves "no doubt" that they were left by dinosaurs, said Boss, whose new research has not yet been published.
"The photographs seem to make it clear that they are indeed theropod dinosaur tracks," vertebrate paleontologist Thomas R. Holtz, Jr. said via email. Theropods, which included T. rex, were two-legged predators.
"Acrocanthosaurus tracks are already well known from Texas, and we have fossils of Acrocanthosaurus and closely related forms from Texas, Oklahoma, and Maryland, so almost certainly it lived in Arkansas, too," added Holtz, of the University of Maryland.
The tracks were likely left by multiple dinosaurs and must have been filled in fairly quickly—if they'd been exposed for long, the prints would have eroded beyond recognition, team member Boss said.
Set Lasers to "Discover"
Boss and colleagues scanned the trackway with a laser at a high resolution. The scan digitally preserved the tracks so that the scientists could analyze them and "walk across that surface in cyberspace," he said..."
Double Impact: Did 2 Giant Collisions Turn Uranus on Its Side?
|11:38:05 PM, Monday, October 10, 2011|
"Knock, knock. That's not the start of a joke but the hard-luck history of Uranus. New research suggests that the giant planet may have suffered two massive impacts early in its history, which would account for its extreme, mysterious axial tilt.
Uranus orbits nearly on its side; its axis of rotation is skewed by 98 degrees relative to an ordinary upright orientation, perpendicular to the orbital plane. Many planetary scientists have sought to explain the odd tilt by invoking a giant impact into Uranus billions of years ago. But the giant planet has a system of moons circling its equator that would have been disrupted by such an impact.
"If Uranus is suddenly tilted, the satellites keep moving like that from north pole to south pole, and [wouldn't be] equatorial at all," Alessandro Morbidelli of the Observatory of Côte d’Azur in Nice, France, reported here Thursday at a joint meeting of the American Astronomical Society Division for Planetary Sciences and the European Planetary Science Congress.
But what if the tilting was a more gradual process, caused not by one mammoth impact but by two somewhat smaller nudges? Simulations show that the two-strike mechanism appears to solve the problem, knocking Uranus sideways and allowing it to develop equatorially orbiting moons, Morbidelli said.
The key is that the impacts must have come very early, before Uranus's moons had coalesced from a disk of gas and dust surrounding the planet. That disk, supplemented by debris stirred up by the collisions, would have migrated around the planet to form a thin equatorial disk that gave rise to Uranus's five large moons.
In the simulations, the same sort of equatorial migration also worked for the single-impact tilt scenario, but that scenario came with one important and disqualifying caveat: the moons orbited in the wrong direction, counter to Uranus's rotation. "If you tilt Uranus all in one shot, you produce regular satellites on the equator, but they will all be retrograde, and the satellites are actually prograde," Morbidelli said..."
Chevrolet Corvette Turns Into Speedboat With $1.7 Million Price Tag
|3:15:47 AM, Sunday, October 09, 2011|
"Seeing a Chevy Corvette tearing up a freeway is a common site all over the United States, but we never thought we'd see one riding the waves. Performance boat manufacturer Marine Technology, Inc. wanted to change that, and the result is an insanely powerful aquatic speed demon called the ZR48 — a boat that boasts neck-snapping speeds and a massive price tag.
Built using parts from a genuine Corvette ZR1, the ZR48 oozes style. Its sleek body lines are undeniably auto-inspired, and great touches like genuine taillights and Corvette badges make it a treat to look at. The boat's body is built out of lightweight carbon fiber, which is as strong as metal but much lighter.
But it's not just the outside that will appeal to Chevy diehards, the interior has been given an equally stunning treatment. After entering through custom gull wing doors, the driver is treated to a true Corvette cockpit, complete with an original shifter and steering wheel. Leather and suede seating provides room for six, and a 8,000 watt sound system ensures that the party never stops.
If you feel like enjoying some quality programming while cruising the open sea, you can switch on the built-in LCD displays which come complete with Apple TV and a mobile wifi hotspot. iPad owners get additional treatment with a custom dock and charging station. The accessories alone are powered by a standalone Fischer diesel motor. The ZR48 has just as much "go" as it has show, and a pair of 1,350 horsepower, twin-turbo Mercury Racing engines deliver speed on demand.
The 48-foot monster boat comes with a special, tricked-out trailer to suit its extra wide stance. The transporter features a total of 5 TVs, a DVD player, LED display lighting, and matching paint scheme. In transit, the boat is situated sideways on the trailer to avoid the need for special highway permits.
As you may have guessed, the customer nature of the ZR48 and its luxurious touches demand top dollar, and a price of no less than $1.7 million is being asked. The one-of-a-kind boat will undoubtedly make you the star of whatever marina you frequent, and wealthy Corvette fans will surely find its charm hard to resist."
Secret Panel Can Put Americans on 'Kill List'
|3:06:04 AM, Sunday, October 09, 2011|
"WASHINGTON (Reuters) - American militants like Anwar al-Awlaki are placed on a kill or capture list by a secretive panel of senior government officials, which then informs the president of its decisions, according to officials.
There is no public record of the operations or decisions of the panel, which is a subset of the White House's National Security Council, several current and former officials said. Neither is there any law establishing its existence or setting out the rules by which it is supposed to operate.
The panel was behind the decision to add Awlaki, a U.S.-born militant preacher with alleged al Qaeda connections, to the target list. He was killed by a CIA drone strike in Yemen late last month.
The role of the president in ordering or ratifying a decision to target a citizen is fuzzy. White House spokesman Tommy Vietor declined to discuss anything about the process.
Current and former officials said that to the best of their knowledge, Awlaki, who the White House said was a key figure in al Qaeda in the Arabian Peninsula, al Qaeda's Yemen-based affiliate, had been the only American put on a government list targeting people for capture or death due to their alleged involvement with militants.
The White House is portraying the killing of Awlaki as a demonstration of President Barack Obama's toughness toward militants who threaten the United States. But the process that led to Awlaki's killing has drawn fierce criticism from both the political left and right.
In an ironic turn, Obama, who ran for president denouncing predecessor George W. Bush's expansive use of executive power in his "war on terrorism," is being attacked in some quarters for using similar tactics. They include secret legal justifications and undisclosed intelligence assessments.
Liberals criticized the drone attack on an American citizen as extra-judicial murder.
Conservatives criticized Obama for refusing to release a Justice Department legal opinion that reportedly justified killing Awlaki. They accuse Obama of hypocrisy, noting his administration insisted on publishing Bush-era administration legal memos justifying the use of interrogation techniques many equate with torture, but refused to make public its rationale for killing a citizen without due process.
Some details about how the administration went about targeting Awlaki emerged on Tuesday when the top Democrat on the House Intelligence Committee, Representative Dutch Ruppersberger, was asked by reporters about the killing.
The process involves "going through the National Security Council, then it eventually goes to the president, but the National Security Council does the investigation, they have lawyers, they review, they look at the situation, you have input from the military, and also, we make sure that we follow international law," Ruppersberger said..."
Jupiter Mistaken for Distress Flare, Rescue Mission Launched
|2:38:05 AM, Sunday, October 09, 2011|
"An RAF Boulmer rescue helicopter and Tynemouth RNLI responded to a call on Monday evening.
As they sought to locate any troubled vessels off the coast of Tynemouth Longsands, in North Tyneside, they could only spot some fishing boats making their way back to the Tyne.
'As the Tynemouth Volunteer Life Brigade spoke further to the member of the public it became apparent that the flares were in fact the planet Jupiter which is very low in the sky at this time of year,' said Tynemouth RNLI's Adrian Don.
'There were several stars visible in the sky at the time. But we were able to plot the position of Jupiter and discovered it was where the caller had reported seeing the distress flare.
'Jupiter gives off a bright red light which could be mistaken for flames. And the fact that it was also partly covered by clouds could have possibly given it the appearance of a flare.'
The RNLI has stressed that the call about the flare was made with the 'best intentions' and was definitely not a prank call."
Plants May Have the Genetic Flexibility to Respond to Climate Change
|12:23:59 AM, Saturday, October 08, 2011|
"Plants may have the genetic flexibility to respond to climate change. In experiments with the common European plant Arabidopsis thaliana, a team of researchers led by Brown University scientists learned that climate is the agent that determines the suite of genes that gives the plant the best chance of surviving and reproducing throughout its natural range. The finding may unlock the molecular basis for other plants' adaptability to climate change. Results appear in Science.
In the face of climate change, animals have an advantage over plants: They can move. But a new study led by Brown University researchers shows that plants may have some tricks of their own.
In a paper published in Science, the research team identifies the genetic signature in the common European plant Arabidopsis thaliana that governs the plant's fitness -- its ability to survive and reproduce -- in different climates. The researchers further find that climate in large measure influences the suite of genes passed on to Arabidopsis to optimize its survival and reproduction. The set of genes determining fitness varies, the team reports, depending on the climate conditions in the plant's region -- cold, warm, dry, wet, or otherwise.
"This is the first study to show evolutionary adaptation for Arabidopsis thaliana on a broad geographical scale and to link it to molecular underpinnings," said Johanna Schmitt, director of the Environmental Change Initiative at Brown and an author on the paper. "Climate is the selective agent."
The researchers believe that by identifying the genetic signatures that mark Arabidopsis' response to changing climate, scientists may understand how climate may cause the re-engineering of the genetic profiles of other plants. "There is still evolutionary flexibility to help plants take one direction or another," said Alexandre Fournier-Level, a postdoctoral researcher at Brown and the paper's first author. "It gives us good hope to see, yes, it's adapting."
"This was a truly massive undertaking, tracking more than 75,000 plants in the field, from near the arctic circle to the Mediterranean coast," said Amity Wilczek, a former postdoctoral researcher in Schmitt's lab now on the faculty at Deep Springs College. "Arabidopsis is an annual plant, so we could measure total lifetime success of an individual within a single year. We gathered plants from a variety of native climates and grew some of each in our four widely distributed European garden sites. We shipped our harvested plants back to Brown and began the laborious task of counting fruits on these plants. In the end, we were able to assemble a very large and comprehensive dataset that gives us new insight into what it takes for a plant to be succesful in nature under a broad range of climate conditions."
The team then burrowed into the Arabidopsis genome to find the molecular mechanisms that might give the plant genetic flexibility to roll with climate punches. To identify variations in the genome among the regional representatives, the researchers carried out a genome-wide association study for survival and fruiting comprising more than 213,000 single-nucleotide polymorphisms. These SNPs, Fournier-Level explained, are like signposts pointing to areas in the genome where survival and reproduction may be emphasized and areas that show variations in the regional representatives' genetic makeup.
From the experiments, the team discovered that the SNPs that determined fitness for Arabidopsis in one region are surprisingly different from those associated with the plant's fitness in another region. The team also learned from the experiments that SNP variants -- "alleles" -- associated with high fitness within each field site were locally abundant in that region, demonstrating a kind of home court advantage at the genomic level..."
Venus Has an Ozone Layer Too: Probe Finds
|12:15:58 AM, Saturday, October 08, 2011|
"ESA's Venus Express spacecraft has discovered an ozone layer high in the atmosphere of Venus. Comparing its properties with those of the equivalent layers on Earth and Mars will help astronomers refine their searches for life on other planets.
Venus Express made the discovery while watching stars seen right at the edge of the planet set through its atmosphere. Its SPICAV instrument analysed the starlight, looking for the characteristic fingerprints of gases in the atmosphere as they absorbed light at specific wavelengths.
The ozone was detectable because it absorbed some of the ultraviolet from the starlight.
Ozone is a molecule containing three oxygen atoms. According to computer models, the ozone on Venus is formed when sunlight breaks up carbon dioxide molecules, releasing oxygen atoms.
These atoms are then swept around to the nightside of the planet by winds in the atmosphere: they can then combine to form two-atom oxygen molecules, but also sometimes three-atom ozone molecules.
"This detection gives us an important constraint on understanding the chemistry of Venus' atmosphere," says Franck Montmessin, who led the research.
It may also offer a useful comparison for searching for life on other worlds.
Ozone has only previously been detected in the atmospheres of Earth and Mars. On Earth, it is of fundamental importance to life because it absorbs much of the Sun's harmful ultraviolet rays. Not only that, it is thought to have been generated by life itself in the first place.
The build-up of oxygen, and consequently ozone, in Earth's atmosphere began 2.4 billion years ago. Although the exact reasons for it are not entirely understood, microbes excreting oxygen as a waste gas must have played an important role.
Along with plant life, they continue to do so, constantly replenishing Earth's oxygen and ozone.
As a result, some astrobiologists have suggested that the simultaneous presence of carbon dioxide, oxygen and ozone in an atmosphere could be used to tell whether there could be life on the planet.
This would allow future telescopes to target planets around other stars and assess their habitability. However, as these new results highlight, the amount of ozone is crucial.
The small amount of ozone in Mars' atmosphere has not been generated by life. There, it is the result of sunlight breaking up carbon dioxide molecules.
Venus too, now supports this view of a modest ozone build-up by non-biological means. Its ozone layer sits at an altitude of 100 km, about four times higher in the atmosphere than Earth's and is a hundred to a thousand times less dense..."
Astronomers Find Elusive Planets in Decade-Old Hubble Data
|12:09:53 AM, Saturday, October 08, 2011|
"In a painstaking re-analysis of Hubble Space Telescope images from 1998, astronomers have found visual evidence for two extrasolar planets that went undetected back then.
Finding these hidden gems in the Hubble archive gives astronomers an invaluable time machine for comparing much earlier planet orbital motion data to more recent observations. It also demonstrates a novel approach for planet hunting in archival Hubble data.
Four giant planets are known to orbit the young, massive star HR 8799, which is130 light-years away. In 2007 and 2008 the first three planets were discovered in near-infrared ground-based images taken with the W.M. Keck Observatory and the Gemini North telescope by Christian Marois of the National Research Council in Canada and his team. Marois and his colleagues then uncovered a fourth innermost planet in 2010. This is the only multiple exoplanetary system for which astronomers have obtained direct snapshots.
In 2009 David Lafreniere of the University of Montreal recovered hidden exoplanet data in Hubble images of HR 8799 taken in 1998 with the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). He identified the position of the outermost planet known to orbit the star. This first demonstrated the power of a new data-processing technique for retrieving faint planets buried in the glow of the central star.
A new analysis of the same archival NICMOS data by Remi Soummer of the Space Telescope Science Institute in Baltimore has recovered all three of the outer planets. The fourth, innermost planet is 1.5 billion miles from the star and cannot be seen because it is on the edge of the NICMOS coronagraphic spot that blocks the light from the central star.
By finding the planets in multiple images spaced over years of time, the orbits of the planets can be tracked. Knowing the orbits is critical to understanding the behavior of multiple-planet systems because massive planets can perturb each other's orbits. "From the Hubble images we can determine the shape of their orbits, which brings insight into the system stability, planet masses and eccentricities, and also the inclination of the system," says Soummer.
These results are to be published in the Astrophysical Journal..."
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