Friday, 30 April 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Plan B: California Braces for Climate Change

Posted: 29 Apr 2010 01:07 PM PDT


When it comes to environmental regulation, California doesn't wait for the Feds to ride in and lay down the law. The Golden State led the way on mandating emissions-control equipment in motor vehicles in 1961. It pioneered tailpipe-emissions standards in 1967 and ratcheted them up into the 1990s, prompting the federal government to follow. When the Environmental Protection Agency proved reluctant to tighten fuel-economy standards, California outmaneuvered it in 2002 by limiting carbon dioxide from cars. That decision achieved the same end — and was the first move in the United States to control greenhouse gases.

climate_desk_bugAnd so it goes with climate change. By the mid-2000s, when the rest of the country was waking up to the challenge of global warming, California was already pursing an aggressive program to assess the likely damage. According to the state energy commission's climate research, the U.S. west coast faces sea-level rise of 12 to 18 inches by 2050, and as much as nearly six feet by the turn of the century. Precipitation is projected to fall increasingly as water rather than snow, draining into the sea rather than lying in cold storage until the long, dry summers. Higher-than-average temperatures and more frequent extreme weather promise heat waves, wildfires, droughts and floods.

The sense of impending crisis sent California Governor Arnold Schwarzenegger into action-hero mode. In 2006, he signed the Global Warming Solutions Act, capping carbon emissions statewide throughout all activities and sectors. Then, last December, he stood on Treasure Island — an expanse of landfill in the San Francisco Bay that stands to be inundated by the upwelling of glacial melt — and unveiled the 2009 California Climate Adaptation Strategy, a plan to prepare for what many scientists regard as inevitable changes. "We have the responsibility to have a Plan B just in case we can't stop the global warming," he said, apparently missing the document's emphatic assertion that mitigation (making efforts to minimize the onset of climate change) and adaptation (learning to live with it) are equally necessary and inherently complementary undertakings.

The strategy document is 200 pages of meticulously footnoted, thoroughly bureaucratic prose that directs state agencies to take climate change into account. Individual chapters are devoted to seven critical sectors: agriculture, biodiversity, coastal resources, energy and transportation, forestry, public health, and water supply and flood protection. The plan outlines the range and severity of potential impacts — eroding coastlines, flooded freeways, extended wildfire seasons, devastating disease outbreaks. The executive summary lists a dozen action items and an appendix of 163 further recommendations.

Mostly, these directives call for better coordination between federal, state and local regulators; updating existing resource-management plans in light of the latest scientific findings; ongoing research to sharpen estimates of impending change; and funding to accomplish these aims and, presumably, the more concrete actions that would follow. Perhaps most interesting is the recommendation to create a website called CalAdapt that would mash up government data with Google maps, providing officials with up-to-date visualizations of rising waters, increasing temperatures and other risks.

Not all of this is new. California's coastal and water agencies have been planning for the impact of climate change since the mid-1980s. Until the turn of the century, though, adaptation was a dirty word in Sacramento. "You got slapped on the head if you mentioned it," says Anthony Brunello, who worked for the Pew Center for Global Climate Change from 1999 to 2001. "It equated to giving up."

But evidence began to mount that the effects were already being felt, particularly a 7-inch rise in sea level at the Golden Gate over the past century, which convinced even hard-core advocates of mitigation that it wasn't too early to consider, say, building sea walls. In late 2008, Schwarzenegger ordered the California Natural Resources Agency to look into what it would take to adapt to the changes wrought by global warming.

By then, Brunello had become California's Deputy Secretary for Climate Change and Energy — and the state was deep into a fiscal crisis. He directed state agencies to form sector-specific working groups that invited business leaders, academics and NGOs to help hash out the strategy. The governor released the plan just in time for the Copenhagen climate summit — only to see it swept off the front pages when leaked e-mails from eminent climate scientists sparked the Climategate scandal.

That was a pity because — lack of bold proposals notwithstanding — the Climate Adaptation Strategy is a significant step forward in the U.S. response to climate change. "Of the dozen states published or working on plans that include adaptation measures, California stands out for the breadth and depth," says Terri Cruce, a climate researcher with the Pew Center for Global Climate Change and the Georgetown Climate Center. (Cruce maintains a website detailing climate-change adaptation initiatives on a state-by-state basis.) The report covers every state agency and reaches into every vital sector that's touched by climate change. Most important, it establishes a permanent task force to guide implementation, so the effort won't die when Schwarzenegger leaves office. And although it may seem trendy, the CalAdapt website looks like an especially smart move, creating a convenient, cost-effective way for officials see how latest projections play out in their jurisdiction.

Which is not to say the document is perfect. "It's a strategy, not a plan," Cruce notes — a set of general directions, not a detailed roadmap. Generally, action items are divided between politically low-cost/low-impact maneuvers (such as adding agricultural inspection stations to catch pests following warmer temperatures northward) and more ambitious goals (a host of measures to restore wetlands that would absorb storm surges) with no deadline, budget or process attached.

The milquetoast language of many recommendations ("Consider requiring applicants to address how sea-level rise will affect their project….") leaves officials with any number of ways to avoid taking action. Moreover, economic analysis is almost entirely absent. Given that both adaptation and mitigation will have a price tag, it's impossible to know which is more expensive in any given case. Is it more costly to cut emissions or relocate San Francisco International Airport on higher ground? And where will the money come from?

The strategy's harshest critics believe that such flaws render it ineffectual. Susanne Moser, a geographer who worked as a consultant on the project, dismisses the near-term goals as merely "best practices" and the long-term objectives as unattainable without a more forceful mandate. But she finds some good in the effort. The most important outcome, she says, isn't the document itself but a cultural shift in Sacramento: The disparate agencies, accustomed to competing for jurisdiction and funding, have discovered the value of cooperation. "They realized they needed to work together if they were going to get beyond business as usual," she says. "That's a huge shift — from 'I don't want to talk to these people' to 'let's work together.' It will make all the difference moving forward."

Despite weaknesses in the plan, most observers view it as an important first step. "There's a broad range of decision makers," says Matt Vander Sluis, who contributed to the effort as global warming program manager at the Planning and Conservation League, an environmental lobbying group based in Sacramento. "Some get it, but others need this type of guidance to wrap their heads around the problem." One immediate result, he points out, is that officials will think twice about approving proposed San Francisco Bay Area developments that would stand below sea level. "It's a useful set of recommendations," he says. "Now, state and federal decision makers need to make the investment in carrying them out, because without resources, it's going to be like trying to put out a fire without a fire hose."

The follow-up is already underway, starting with the top-line directive: formation of a task force to establish future priorities. William Reilly, who served as the first President Bush's head of the Environmental Protection Agency, leads the group, which is due to report its recommendations to the governor by summer. Meanwhile, the strategy will be updated every two years. By the time the first biennial review rolls around in late 2011, the short-term goals should be complete and presumably the roadmap to the more politically challenging recommendations will have been sketched in. That is, unless California finds that adapting to the new politics of climate change even harder than responding to the change itself.

This report was produced by the Climate Desk collaboration.

Image: The central San Francisco Bay coastline has areas, including the San Francisco International Airport, that will be inundated by a 16-inch sea-level rise (in light blue) and a 55-inch sea-level rise (in dark blue)./San Francisco Bay Conservation and Development Commission.

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Ted Greenwald is a writer and editor in Northern California.

What Cuba Can Teach Us About Health Care

Posted: 29 Apr 2010 10:55 AM PDT


Just a morning's boat ride from the tip of Florida is a place where medical costs are low and doctors plentiful. It's Cuba, and Stanford University physician Paul Drain says it's time for the United States to pay attention to our neighbor's shoestring success.

Despite a 50-year trade embargo by the United States and a post-Soviet collapse in international support, the impoverished nation has developed a world-class health care system. Average life expectancy is 77.5 years, compared to 78.1 years in the United States, and infant and child mortality rates match or beat our own. There's one doctor for every 170 people, more than twice the per-capita U.S. average.

Not everything is perfect in Cuba. There are shortages of medicines, and the best care is reserved for elites. But it's still a powerful feat. "In Cuba, a little over $300 per person is spent on health care each year. In the U.S., we're spending over $7,000 per person," said Drain, co-author of Caring for the World and an essay published April 29 in Science. "They're able to achieve great health outcomes on a modest budget."

With Fidel Castro's reign as Cuba's leader ending two years ago, relations with the United States have thawed. President Obama eased restrictions on travel to Cuba last year, and the oft-introduced Free Trade With Cuba Act finally has a chance of passing Congress. Drain would like the Institutes of Medicine to conduct a full study of the island nation's success.

"There are so many lessons we might be able to learn from Cuba's health care and medical education system, but we don't know too much about it," said Drain. How does Cuba keep health care costs so low?

Paul Drain: Partly by keeping physicians' salaries low. Obviously, given the government they have, they can do that. But they also emphasize primary care and preventive care, addressing diseases and problems before they become major. It's a very different approach to health care.

In the United States, we essentially do the opposite. We treat diseases when they occur. We're not very good at the preventive component, which causes the costs of our health system to be much higher. What are the origins of Cuba's approach?

Drain: Starting in 1964, they encouraged all medical school graduates to do at least two years of service in a rural area. That program became so popular that by the mid-1970s, almost all new physicians were doing rural service. From there, almost all medical graduates were channeled into a three-year family medicine residency. That's where they do clinical training, making the transition to full doctor from medical student.

Almost all their residents do family medicine. They focus on primary care for all ages. Once everybody learns primary care, about 35 percent go on and specialize. It's quite the opposite of what we have here. How so?

Drain: Our medical students choose what they want to do. Only about 7 or 8 percent go into family medicine, which is our primary care system. In Cuba, everyone becomes a primary care doctor. They learn to prevent diseases.

Cuba also provides very good access. In the mid-1980s, they created a system of neighborhood doctors' clinics. One doctor is responsible for a catchment area of a couple of city blocks. They get to know their patients well. If somebody has a problem, they can see the doctor in the clinic that day. Could the U.S. government ever mandate a system like that?

Drain: It would be a big leap, but there are smaller steps that could be taken. We're the only developed country without universal access to a nationalized health care system. Other countries have seen health care as a basic right and insured everybody. Everyone gets primary care. That would be a first step.

I saw someone in my clinic yesterday who hadn't seen a doctor in 10 years. Her blood pressure was through the roof, and it's probably been like that for a decade. She's at tremendous risk for having a stroke or heart problems. If she'd seen somebody back when this started, it could have been controlled. But because of her high blood pressure, who knows what her future medical bills will be like.

If she were in the Cuban system, she would have had a visit scheduled yearly for the last 10 years. If she hadn't shown up, someone would have gone to her home to see if she was OK. Blood pressure is an easy thing to check. It would have been controlled. One problem in the United States is the shortage of doctors. How does Cuba train physicians?

Drain: Education is paid by the government, so students don't have debt. In the United States, medical students come out $200,000 or $300,000 in the hole, which deters them from going into primary care. Cuban doctors are making a fraction of what we make in the U.S., but most Cubans aren't going into medicine to earn money. They're going into it to treat people in their communities.

In 1999, Cuba created a school of medicine for Latin America. They bring students in, train them for six years, give them room and board and a stipend. Afterward the students are required to go home and practice in poorer communities. It's a remarkable program, with 10,000 students now from 33 countries, and an interesting model for developing health care workers. Do President Obama's health reforms move the United States toward what's seen in Cuba?

Drain: What we're passing is starting to move us in a better direction. I'm an advocate for universal health care, and there's still a long way to go. But I think we'll eventually catch up to our western counterparts, and realize that we're the only country not providing full equity in terms of accessing health care, and that's reflected in health outcomes. When you compare us against most developed countries, we're near the bottom in most health indicators. Our life expectancy isn't as good, our infant mortality rates are higher, and we're spending twice as much money.

Image: Cuba and the southern tip of Florida./NASA.

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Citation: "Fifty Years of U.S. Embargo: Cuba's Health Outcomes and Lessons." By Paul K. Drain and Michele Barry. Science, Vol. 328 No. 5977, April 30, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Gene Grows Worm Heads

Posted: 29 Apr 2010 10:13 AM PDT


A worm named Schmidtea mediterranea has the unique ability to regenerate not only its limbs, but also its head and brain. Now, scientists studying the worm have discovered one of the genes that allows it to accomplish this amazing feat.

The gene, called "smed-prep," regulates the location and structure of the flatworm's brain during regeneration. When the gene is absent, the worm forms a stump with random junk from other parts of its body, but no brain. When it's expressed in other areas of the body, heads can be made to sprout from anywhere.

"One of the main goals in the lab was to understand the mechanisms that allowed this worm to regenerate its head, brain and sensory organs," said molecular biologist Aziz Aboobaker of the University of Nottingham, lead author of the paper published in PLoS Genetics April 22. "It's a big problem because you have to make this all from the old tissue. The cells have to mobilize, migrate to the right place and differentiate."

The S. med worm is small, but has complex organs and a primitive bilateral brain. Not only can it regenerate its head and brain, but each piece you cut off (down to about 1 millimeter) can re-grow into a complete organism. The worm can do this because about 25 percent of its cells are stem cells, which can differentiate into any cell type.

To find the gene, Aboobaker scanned the worm's genome looking for developmental genes. After testing several other genes, Aboobaker's team stumbled upon smed-prep, whose expression was concentrated in the worm's head region.

To see how the gene affected the worm's ability to regenerate, they tricked the cell into destroying any messenger RNA or protein made from it, using interfering RNA. The worms who had their gene expression cut down were unable to regenerate their brains after amputation, but other aspects of the regeneration process were unaffected.

"That's the interesting thing, we haven't killed them off, they are still healthy," Aboobaker said. "They just can't navigate or find food."

Humans have a gene that is similar in biochemical structure and genetic code to smed-prep, but its function in humans is unknown. Related genes in other vertebrates, like mice and zebrafish, are expressed in the brain during embryo formation.

"The most interesting aspect of this paper is its evolutionary perspective," said cell biologist Alejandro Sánchez Alvarado, of the University of Utah, because C. elegans (a commonly studied worm) and drosophila (the fruitfly) do not appear to have evolved a directly corresponding gene. Alvarado previously discovered two other genes involved with S. med's head regeneration process.

The worm and its properties can teach us more about human health, because it's a good model system to learn about stem cells, regeneration and aging, said Aboobaker.

"You can't just make neurons from stem cells, then insert them into your brain, because you have no idea what would happen," he said. "If you ask someone to make you a brain from a ball of tissue, they won't be able to, because we don't know how. But the worm does."

The team's next step is to determine what other genes are regulated when smed-prep is turned on and off."Finding [smed-prep] means you can find which genes don't turn on properly when it is knocked down," Aboobaker said. "Those are the genes that must be involved in this network that makes the brain."

Image: Wikimedia Commons/Alejandro64

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Citation: "The TALE Class Homeobox Protein Smed-prep Defines the Anterior Compartment for Head Regeneration." By Daniel A. Felix and A. Aziz Aboobaker. PLoS Genetics Vol. 6, Issue 4, April 22, 2010.

See Better by Believing You Can

Posted: 29 Apr 2010 10:04 AM PDT


Imagine seeing better by thinking differently. That's a vision with a future, according to Harvard University psychologist Ellen Langer.

sciencenewsEyesight markedly improved when people were experimentally induced to believe that they could see especially well, Langer and her colleagues report in the April Psychological Science. Such expectations actually enhanced visual clarity, rather than simply making volunteers more alert or motivated to focus on objects, they assert.

Langer's new findings build on long-standing evidence that visual perception depends not just on relaying information from the eyes to the brain but on experience-based assumptions about what can be seen in particular situations. Those expectations lead people to devote limited attention to familiar scenes and, as a result, to ignore unusual objects and events.

In perhaps the most eye-popping of Langer's new findings, 20 men and women who saw a reversed eye chart — arranged so that letters became progressively larger further down the chart, with a giant "E" at the bottom — accurately reported more letters from the smallest two lines than they did when shown a traditional eye chart with the big letters on top. All volunteers had normal eyesight.

These results reflect people's expectation, based on experience with standard eye charts, that letters are easy to see at the top and become increasingly difficult to distinguish on lower lines, the researchers suggest.

Participants who said they thought that they could improve their eyesight with practice displayed a bigger vision boost on the reversed chart than those who didn't think improvement was possible, but only for the next-to-smallest line. Both groups did equally well at reading the smallest, topmost line.

Another set of experiments included 63 members of the Reserve Officers' Training Corps at MIT. Eye testing determined that their vision ranged from below average to excellent.

An experimenter told a group of 22 cadets to assume the role of a fighter pilot while operating a flight simulator. During this exercise, participants tried to identify letters shown on four plane wings of approaching aircraft. Each wing contained one of the bottom four lines of an eye chart.

Another 20 cadets performed the visual task while pretending to fly a plane in a simulator that they were told was broken. Ten other cadets read a motivational essay before the exercise. A final group of 11 cadets didn't use a simulator but practiced eye exercises that researchers described as capable of improving eyesight before taking an eye test.

Vision improved substantially for nine of 22 simulator pilots compared with none of those who pretended to fly, two of 11 eye exercisers and one person in the motivational group. Simulator pilots did so well relative to the others because they more thoroughly adopted a mind-set of being real fighter pilots with presumably superior vision, the researchers posit. An initial survey of ROTC members found that they attributed particularly good vision to fighter pilots.

Simulator pilots with below-average vision displayed the biggest jumps in visual performance, perhaps because they had more room for improvement, the researchers suggest.

These results suggest that if eye exercise programs designed to improve vision work for some people, it's not because of any physical effect on the eyes or brain. Such regimens "may be effective because they prime the belief that exercise improves vision," Langer and her colleagues write.

Mind-set may boost visual performance without sharpening vision itself, comments psychologist Daniel Simons of the University of Illinois at Urbana-Champaign. Experimental manipulations in the new study, such as reversing the arrangement of an eye chart, may have made volunteers more willing to guess when they felt a bit unsure, Simons says. Such guesses stand a good chance of being right, in his view.

Image: lenoz/flickr

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Twin Study Deepens Multiple Sclerosis Mystery

Posted: 28 Apr 2010 02:28 PM PDT


The most detailed genetic investigation ever of multiple sclerosis has produced more questions than answers.

Using extremely fine-grained analytical tools, scientists compared genetic information in three sets of identical twins. One of each pair had MS, and the other didn't — yet their genes proved essentially identical.

"We find no smoking gun on the genetic level," said National Center for Genome Resources geneticist Stephen Kingsmore, co-author of the study published April 28 in Nature.

The research cost $1.5 million, and the scientists took 18 months to sequence 2.8 billion DNA units in each twin, and determine whether they came from the mother or father. Most genomic comparisons look for differences in a just handful of suspect genes, and even whole-genome approaches don't differentiate between parental contributions.

The researchers also analyzed the twins' CD4 cells, a type of white blood cell that plays a central role in the development of MS. In these cells, the researchers sequenced epigenomes — chemical instructions that turn genes on and off — and transcriptomes, or a chemical record of genes that are actively coding proteins.

These multiple layers of information represent the cutting edge of genomic analysis, and are expected to reveal what rougher tools cannot. "This was a technical tour de force, and potentially represents a new way of looking at disease states," said Kingsmore. Nevertheless, they found no differences.

The absence of genetic differences doesn't mean that genetics are irrelevant to multiple sclerosis. Identical twins, who are descended from the same egg, are six times more likely to develop MS than non-identical twins, who come from two different eggs.

It's still possible that some as-yet-unknown genetic factor, undetectable by even the most advanced tools, may explain the discordance in the study. However, Kingsmore thinks the culprit is probably an unknown environmental influence. "There must be a nongenetic factor, probably environmental," that combines with known genetic and environmental risks, he said.

The researchers would like to look at more twins, and other types of cells. Even so, the study "was a pioneering effort on a scale that hasn't been done before," said Kingsmore. "We're left with this mystery."

Image: Combination of cover image of the current issue of Nature and transcriptome readings from the study./Nature

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Citation: "Genome, epigenome and RNA sequences of monozygotic twins discordant for multiple sclerosis." By Sergio E. Baranzini, Joann Mudge, Jennifer C. van Velkinburgh, Pouya Khankhanian, Irina Khrebtukova, Neil A. Miller, Lu Zhang, Andrew D. Farmer, Callum J. Bell, Ryan W. Kim, Gregory D. May, Jimmy E. Woodward, Stacy J. Caillier, Joseph P. McElroy, Refujia Gomez, Marcelo J. Pando, Leonda E. Clendenen, Elena E. Ganusova, Faye D. Schilkey, Thiruvarangan Ramaraj, Omar A. Khan, Jim J. Huntley, Shujun Luo, Pui-yan Kwok, Thomas D. Wu, Gary P. Schroth, Jorge R. Oksenberg, Stephen L. Hauser, & Stephen F. Kingsmore. Nature, Vol. 464 No. 7293, April 29, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Ice Discovered on Asteroid, Suggests Earth’s Oceans Came From Space

Posted: 28 Apr 2010 01:50 PM PDT


Water ice and organic molecules have been discovered on the surface of an asteroid for the first time.

Researchers glimpsed the ice on 24 Themis, the largest member of an asteroid family located between the orbits of Mars and Jupiter, using the NASA Infrared Telescope on Mauna Kea in Hawaii. This frosty little rock could be the key to understanding how Earth became the blue planet.

"What we've found suggests that an asteroid like this one may have hit Earth and brought our planet its water," said astronomer Humberto Campins of the University of Central Florida, the lead of one of the two separate teams that reported similar findings April 28 in Nature.

While there is plenty of debate around how Earth got its oceans, this new evidence suggests some of the water came from extraterrestrial sources. Here's how it may have happened: More than four billion years ago, after a massive collision between Earth and another large object created the moon, our planet was completely dessicated. Then, during the Late Heavy Bombardment period that followed, during which lots of asteroids hit Earth, the ice that the objects carried became our store of water.

"The more we find in our asteroid belt objects that do have water, the more convinced we are that that was a possible process to rehydrate the earth," said NASA astrobiologist Mary Voytek.

The ice on Themis 24 could be a sort of time capsule from the early solar system and could be similar to the ice that may have arrived on Earth from asteroids during the Heavy Bombardment.

"The ice that we see there, right now, is sort of related to the ice that could have come from the main asteroid belt that hit us about 4 billion years ago," astronomer Henry Hsieh of Queen's University Belfast told NPR. "It gives us a way to kind of probe the cousins of the asteroids that hit us and probably gave us water in the early stages of the Earth's formation." Hsieh wrote a commentary that accompanied the stories in Nature.

The presence of ice and organic molecules on the surface of an asteroid is the latest in a string of discoveries that collectively indicate water ice is a more common substance than we might have thought. In just the past few years, scientists have confirmed the presence of ice at the moon's north pole as well as beneath the surface of Mars.

It had previously been thought that asteroids were too warm to retain water ice on their surfaces. The exact method for how they do so remains unclear.

Image: Artist's conception of asteroid 24 Themis and two small fragments of this dynamic family, which resulted from a large impact more than one billion years ago. One of the small fragments is inert (as most asteroids are), and the other has a comet-like tail, produced by the sublimation of water ice from its surface.
Gabriel Pérez/Servicio MultiMedia, Instituto de Astrofisica de Canarias, Tenerife, Spain

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Feathered Dinosaurs Molted Like Birds

Posted: 28 Apr 2010 10:30 AM PDT


Like kids today who don't want to dress like Mom and Dad, some young feathered dinosaurs sported a look totally unlike their elders, a new study shows.

sciencenewsThe finding hints that feathered dinosaurs, like modern birds, molted as they grew, says study coauthor Xing Xu, a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing.

The dramatic age-related shift in plumage was noted in newly described fossils of Similicaudipteryx, a feathered creature that lived in what is now China about 125 million years ago. Xu and his colleagues analyzed two well preserved specimens of Similicaudipteyrx and report their findings in the April 29 Nature.

Both fossils are thought to come from juveniles, because the vertebrae aren't completely fused, which happens as animals reach adulthood, Xu says. In the larger and presumably older of the two specimens — a creature with an upper leg bone about 12 centimeters long and a body the size of a goose — the long feathers on the forelimbs and tail look just like modern bird feathers.

But in the pigeon-sized smaller creature, feathers on the forelimb and tail look modern only near their tips, Xu says. Closer to the body, those feathers have a ribbonlike shape but no central shaft — a type of structure previously seen in the tail feathers of some other Chinese feathered dinosaurs.

Unlike today's birds, these dinosaurs changed the basic structure of their feathers some time during adolescence, says Xu, probably due to different timing and patterns of gene activity.

Image: The strikingly different flight feathers of two individuals at different ontogenetic stages of the oviraptorosaurian Similicaudipteryx./Xing Lida and Song Qijin.

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Semi-Natural Biotech Hack Makes Bones Heal 3 Times Faster

Posted: 28 Apr 2010 10:05 AM PDT


Mice healed three times faster than normal after their broken bones were flooded by proteins naturally used to regrow new tissues. The discovery raises the possibility of a stem cell–free route to regeneration.

The Wnt family of proteins used in the mice are involved in healing many other types of tissue; the researchers hope they will find many other uses for them.

"Gut, skin, brain, muscle, cardiac muscle, corneas, retinas — people have studied the role of Wnt signals in all those tissues," said Stanford University reconstructive surgeon and study co-author Jill Helms. "Maybe there could be a therapeutic approach to all this."

The experiment, published April 28 in Science Translational Medicine, is rooted in two decades of research on Wnt genes and proteins, which play a variety of regenerative roles. They help embryonic stem cells make copies of themselves, keeping a body's supply fresh, and guide the maturation of stem cells into specific cell types.

Wnt proteins are found throughout the animal kingdom, from sponges and flatworms to mice and humans, and their function seems to be consistent. When tissues are injured, Wnt genes in surrounding cells become more active, pumping out extra Wnt proteins. Arriving repair cells divide faster and grow more rapidly.

Study co-author Roel Nusse, a cell biologist at Stanford, has pioneered much of the Wnt research. He was responsible for cloning the Wnt family genes, allowing proteins to be produced in tissue cultures in a lab. His success encouraged the study's other authors to see if the proteins could be used therapeutically.

"This pathway may be the key to regenerating, or at least rapidly repairing, tissues," said Helms. "We're augmenting nature's own response to injury."

The researchers started their tests by genetically engineering a strain of mice that produced exceptionally high amounts of Wnt proteins. Three days after their bones were broken, they grew three and half times more new bone tissue than regular mice.

That test's purpose wasn't to investigate a role for genetic engineering, but rather to see if extra Wnt had an effect. The researchers next injected lab-grown Wnt proteins into mice with broken bones. These again healed three times faster.

There were no obvious side effects from the treatment, though the tests were preliminary. Somewhat disturbingly, Wnt genes were originally identified while malfunctioning in cancerous cells. The likelihood of causing cancer is also a major obstacle to developing safe stem cell therapies. But Helms is confident that it won't be a problem with potential Wnt therapies.

"In cancer, mutations cause the pathway to be always on. Delivering the protein only causes the pathway to be turned on for a moment," she said. "Mutations in the insulin pathway also cause cancer, but insulin treatments do not."

According to Thomas Einhorn, a Boston University biochemist and orthopedic surgeon who wasn't involved in the study, Wnt is an alluring therapeutic target. Malfunctions in Wnt regulation have been linked to human bone disorders, underscoring their importance. But he cautioned that "animal studies are animal studies, and human conditions are something else."

In mice, challenges still remain. A broken bone is relatively easy to target with an injection, but many conditions are less localized, involving entire organs or large amounts of tissue.

The researchers are now conducing mouse tests of Wnt proteins for skin wounds, stroke and heart-attack recovery, and cartilage injuries.

"Nature uses this recipe over and over again," said Helms.

Image: Healing in the skeletal tissues of mice given a placebo (top) and Wnt proteins (bottom).
Science Translational Medicine.

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Citation: "Wnt Proteins Promote Bone Regeneration." By S. Minear, P. Leucht, J. Jiang, B. Liu, Y. A. Zeng, C. Fuerer, R. Nusse, J. A. Helms. Science Translational Medicine, Vol. 2 No. 29, April 28, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

High Metabolism Fueled Evolution of Bat Flight

Posted: 27 Apr 2010 11:49 AM PDT


From wings to low-density bones to echolocation, the evolution of flight in bats required many radical changes. But the most important change may have been metabolic.

A genetic comparison of dozens of mammal species shows that bats possess highly modified versions of genes responsible for turning food into energy. Improved energy efficiency would have encouraged their ancestors to move from treetop gliding, like modern flying squirrels, to actively flapping their arms.

"Gliding doesn't require huge amounts of energy, but when you start flapping your arms, you start needing more," said David Irwin, a University of Toronto evolutionary biologist. "Changes in energy synthesis need to get well underway before you get sustained flight."

The bat evolution study, published April 26 in the Proceedings of the National Academy of Sciences, grew from lead author Ya-Ping Zhang's interest in avian energy metabolism. In an earlier comparison of flightless and flying birds, the Chinese Academy of Sciences zoologist found that flightless birds had fewer genetic changes in their mitochondria — the cellular structures that turn oxygen and nutrients into chemical energy. Zhang wondered if mitochondria and flight were tightly linked in mammals, too.

The researchers analyzed mitochondrial genes from four species of bats and 60 other mammal species. By comparing the differences against known evolutionary histories, they extrapolated what mitochondria in a last common ancestor might have looked like.

When they compared modern bat mitochondria to the ancestral animal, they found profound changes in a subset of genes that code for enzymes that break down nutrients — the fuel cells of the fuel cells, so to speak. In bats, up to 23 percent of these genes show signs of adaptations. Just 2 percent of other genes have changed.

Because bats were fully formed by the time they appear in the fossil record, scientists don't know which adaptations came first. But Irwin thinks the mitochondrial changes must have come early, and are most important. To support their airborne lifestyle, bats require three to five times more energy than other mammals their size.

Irwin next hopes to study the physical structure of enzymes produced by bat mitochondria, with the aim of discovering exactly what makes them so efficient. The insights might eventually be applied to metabolic disorders like obesity and diabetes. "Maybe this will give us a better understanding of how to make our own energy system more efficient," Irwin said.

Image: Jessica Nelson/National Science Foundation.

Citation: "Adaptive evolution of energy metabolism genes and the origin of flight in bats ." By Yong-Yi Shen, Lu Liang, Zhou-Hai Zhu, Wei-Ping Zhou, David M. Irwin and Ya-Ping Zhang. Proceedings of the National Academy of Sciences, Vol. 107. No. 17, April 27, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

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EPA Scientist Says East Coast Beaches Threatened by Sea Level, But Nobody’s Listening

Posted: 27 Apr 2010 11:26 AM PDT


For most of the 20th century, Chesapeake Beach, Maryland, was known for its boardwalk, amusement park and wide, sandy beaches, popular with daytrippers from Washington, D.C. "The bathing beach has a frontage of three miles," boasted a tourist brochure from about 1900, "and is equal, if not superior, to any beach on the Atlantic Coast."

climate_desk_bugToday, on a cloudless spring afternoon, the resort town's sweeping view of Chesapeake Bay is no less stunning. But there's no longer any beach in Chesapeake Beach. Where there once was sand, water now laps against a seven-foot-high wall of boulders protecting a strip of pricey homes marked with "No Trespassing" signs.

Surveying the armored shoreline, Jim Titus explains how the natural sinking of the shoreline and slow but steady sea-level rise, mostly due to climate change, have driven the bay's water more than a foot higher over the past century. Reinforcing the eroding shore with a sea wall held the water back, but it also choked off the natural supply of sand that had replenished the beach. What sand remained gradually sank beneath the rising water.

Titus, the Environmental Protection Agency's resident expert on sea-level rise, first happened upon Maryland's disappearing beaches 15 years ago while looking for a place to windsurf. "Having the name beach," he discovered, "is not a very good predictor of having a beach." Since then, he's kept an eye out for other beach towns that have lost their namesakes—Maryland's Masons Beach and Tolchester Beach, North Carolina's Pamlico Beach, and many more. (See a map of Maryland's phantom beach towns here.) A 54-year old with a thick shock of hair and sturdy build, Titus could pass for a vacationer in his Panama hat, khakis and polo shirt. But as he picks his way over the rocky shore, he's anything but relaxed.

For nearly 30 years, Titus has been sounding the alarm about our rising oceans. Global warming is melting polar ice, adding to the volume of the oceans, as well as warming up seawater, causing it to expand. Most climatologists expect oceans around the world to rise between 1.5 and 5 feet this century. Some of the hardest-hit areas could be in our own backyard: Erosion and a shift in ocean currents could cause water to rise 4 feet or more along much of the East Coast. Titus, who contributed to the Intergovernmental Panel on Climate Change's Nobel Prize-winning 2007 report, has done more than anyone to determine how those rising seas will affect us and what can be done about them.

Like his occasional collaborator, NASA climatologist James Hansen, Titus has decided to speak out. He's crisscrossed the country to meet with state and local officials in coastal areas, urging them to start planning now for the slow-motion flood. Yet his warnings have mostly fallen on deaf ears. "We were often told by midlevel officials that their bosses did not want to plan for anything past the next election," he says.

Neither, it seems, does the federal government. Over the past decade, Titus and a team of contractors combined reams of data to construct a remarkably detailed model of how sea-level rise will impact the eastern seaboard. It was the largest such study ever undertaken, and its findings were alarming: Over the next 90 years, 1,000 square miles of inhabited land on the east coast could be flooded, and most of the wetlands between Massachusetts and Florida could be lost. The favorably peer-reviewed study was scheduled for publication in early 2008 as part of a Bush Administration report on sea-level rise, but it never saw the light of day — an omission criticized by the EPA's own scientific advisory committee. Titus has urged the more science-friendly Obama administration to publish his work, but so far, it hasn't — and won't say why.

So Titus recently launched a personal website,, to publish his work. "I decided to do my best to prevent the taxpayer investment from being wasted," he says. The site includes "When the North Pole Melts," a prescient holiday ditty recorded by his musical alter ego, Captain Sea Level, in the late '80s.

Titus gazes at Chesapeake Beach's jagged shoreline, where two children scramble over the barrier of large gray boulders known as a revetment. "The children of 21st-century Chesapeake Beach, what do they do?" he asks. "They play on revetments." A generation ago, these kids might have been skipping through the waves. A generation from now, many of the rocks they're playing on will almost certainly be underwater.

Living near the ocean has always come with the risk of getting wet. Yet coastal dwellers whose homes got swamped by the occasional storm surge could rely on the water to eventually recede. That certainty is gone. Titus has calculated that a 3-foot rise in sea level will push back East Coast shorelines an average of 300 to 600 feet in the next 90 years, threatening to submerge densely developed areas inhabited by some 3 million people, including large parts of New York City, Philadelphia, and Washington, D.C. As Margaret Davidson, director of the National Oceanic and Atmospheric Administration's Coastal Services Center in Charleston, South Carolina, puts it, "Today's flood is tomorrow's high tide."

The rising waters can be kept at bay by constructing dikes and bulkheads, pumping sand to fill out receding beaches, and elevating existing buildings and roads on embankments or pylons. But such efforts may prove prohibitively expensive: Titus says that in the lower 48 states alone, they could cost as much as $1 trillion over the next century. He estimates that in the process, 60 to 90 percent of the east coast's wetlands could be destroyed as bulkheads and other defensive measures restrict the movement of estuaries and marshes, drowning them when the ocean rises.

So are developers getting ready for the water? The National Association of Home Builders, the housing industry's largest trade group, has no policy on adapting coastal projects to account for rising sea levels. "While sea-level rise may be a real issue in some areas," Susan Asmus, NAHB's senior vice president of regulatory and environmental affairs, told me in an e-mail, "it is but one of many considerations that are likely already taken into account during the planning process." Mother Jones contacted the nation's 10 largest homebuilders, including D.R. Horton, Pulte Homes, and Lennar. None would say how they are responding to sea-level rise.

Nor is there any evidence that the issue has much traction with homeowners — and why should it? Property insurance is readily available in most coastal areas, if not through private insurers, then through state governments and FEMA's National Flood Insurance Program. Though the NFIP requires policyholders to live above the 100-year high-water mark, it doesn't account for how that line may creep inland in the future. Besides, most people would plan to resell their beach houses long before they expect them to be swallowed by encroaching waves.

What about government? Most coastal states have done little or nothing to regulate shoreline development, often from fear of litigation. In 1988, South Carolina's Beachfront Management Act required new beach homes to be set back far enough from the water to be protected from at least 40 years of erosion. A property owner named David Lucas sued, and the U.S. Supreme Court eventually ruled that the construction ban had deprived him of any "economically viable use" of his coastal properties, a "taking" that required the state to compensate him. "After Lucas, fewer people spoke seriously about stopping development," Titus says.

A few state and local governments have taken more constructive action. Several states limit development near tidal waters (Maine and Rhode Island have done this specifically in response to sea-level rise). Chatham, Massachusetts, cites sea-level rise as one reason why it prohibits new homes, even elevated ones, below 100-year flood lines. (State courts have upheld those limits in Chatham and Maine because they still allow property to be used for recreation, farming, and other profitable activities.) In California, where erosion and winter storms routinely knock multimillion-dollar homes off seaside cliffs, the state's Coastal Commission has long required anyone who builds on coastal bluffs to submit a geotechnical report proving that their home won't fall into the ocean. Three years ago, it began requiring the reports to account for sea-level rise. And in a groundbreaking 2008 executive order, Governor Arnold Schwarzenegger directed state agencies to plan for sea-level rise in their construction projects.

A handful of developers have also started to seriously grapple with sea-level rise. A residential high-rise project on Treasure Island, a former naval base in San Francisco Bay, is being built far from the shoreline and is reserving funds for a protective berm if the water rises even higher than the 3 feet that's anticipated. And in the wake of Hurricane Katrina, the insurance industry drew up standards to fortify houses for stronger hurricanes and higher waves. So far, though, only 200 houses nationwide have been built to comply with the standards.

Most coastal dwellers are focused on riding out the next surge, not the next century. You can't really blame them — nobody really wants to hear that their days on the beach are numbered.

Case in point: Beyoncé's dad. Matthew Knowles has been locked in a bitter struggle to save his beach house in Galveston, Texas, which now sits on top of the high-tide line thanks to Hurricane Ike. In most states, Knowles would be allowed to shore up his home, but not in Texas, which is known for one of the most progressive laws in the country on beach access. The state's Open Beaches Act provides that beach is a public resource that must be protected from "erosion or reduction caused by development."

Last year, after Knowles started reinforcing his property with tons of cement, the Texas General Land Office informed him that paving over the beach is illegal. Even so, he continued and then surrounded his home with sod, planters, and sandbags. In March, the agency notified Knowles that it was preparing to fine him up to $2,000 a day for violating the Texas Open Beaches Act by interfering with "the right of the public to use the beach." Knowles did not respond to a request for comment.

Historically, the 51-year-old law has been used to prevent property owners from walling off the beach in front of their homes. But officials say the law clearly applies even when the beach comes to the houses, rather than vice versa. "Even if you make $80 million a year, we don't care," says Jim Suydam, a spokesman for the Texas General Land Office. "The beach is the public's." Incorporated into the state constitution last year and vigorously supported by the state's conservative, gun-packing land commissioner, the Open Beaches Act is remarkably popular, in part because it can guarantee beach access for ATVs.

Titus views the Texas Open Beaches Act as one of the more promising tools for preparing for higher water. It has unintended environmental benefits, ensuring that beaches can migrate inland instead of being walled off and at the same time, it sidesteps any debate over climate change. "Developers who deny that the sea will rise would view the policy as costing them nothing," because it wouldn't prevent them from building near the shore, he notes. Only the diehard beach dwellers would stand to get soaked.

Kate Sheppard contributed to this report.

This piece was produced by Mother Jones as part of the Climate Desk collaboration.

Image: Elevations of land close to sea level in upper Chesapeake Bay. Elevations are above spring water, which is the average high tide during the new and full moons, and approximately the inland boundary of tidal wetlands.
J.G. Titus and J. Wang/EPA (2008)

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Josh Harkinson is a staff reporter at Mother Jones, and Kate Sheppard covers energy and environmental politics in Mother Jones' Washington bureau.

Saturday, 17 April 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Why It’s So Hard to Tell Which Tooth Has the Ache

Posted: 16 Apr 2010 03:27 PM PDT


When it comes to a toothache, the brain doesn't discriminate. A new imaging study shows that to the brain, a painful upper tooth feels a lot like a painful lower tooth. The results, which will be published in the journal Pain, help explain why patients are notoriously bad at pinpointing a toothache.

sciencenewsFor the most part, humans are exquisitely tuned to pain. The brain can immediately distinguish between a splinter in the index finger and a paper cut on the thumb, even though the digits are next-door neighbors. But in the mouth this can be more difficult, depending where and how intense the ache is.

"We don't know much about tooth pain," comments dentist and neuroscientist Alexandre DaSilva of the University of Michigan in Ann Arbor, who was not part of the new research. The new study is one of the first to address the puzzle of toothache localization, he says.

In the study, researchers led by Clemens Forster of the University of Erlangen-Nuremberg in Germany analyzed brain activity in healthy — and brave — volunteers as they experienced tooth pain. The researchers delivered short electrical pulses to either the upper left canine tooth (the pointy one) or the lower left canine tooth in the subjects. These bursts of electrical stimulation produced a painful sensation similar to that felt when biting into an ice cube, Forster says, and were tuned such that the subject always rated the pain to be about 60 percent, with 100 percent being the worst pain imaginable.

To see how the brain responds to pain emanating from different teeth, the researchers used fMRI to monitor changes in activity when the upper tooth or the lower tooth was zapped. "At the beginning, we expected a good difference, but that was not the case," Forster says.

Many brain regions responded to top and bottom tooth pain — carried by signals from two distinct branches of a fiber called the trigeminal nerve — in the same way. The V2 branch carries pain signals from the upper jaw, and the V3 branch carries pain signals from the lower jaw.

In particular, the researchers found that regions in the cerebral cortex, including the somatosensory cortex, the insular cortex and the cingulate cortex, all behaved similarly for both toothaches. These brain regions are known to play important roles in the pain projection system, yet none showed major differences between the two toothaches. "The activation was more or less the same," Forster says, although he adds that their experiments might have missed subtle differences that could account for why some tooth pain can be localized.

Because the same regions were active in both toothaches, the brain — and the person — couldn't tell where the pain was coming from. "Dentists should be aware that patients aren't always able to locate the pain," Forster says. "There are physiological and anatomical reasons for that."

DaSilva agrees that the brain's inability to tell top-tooth pain from bottom-tooth pain "pairs really well with what we see in the clinic."

Understanding the pathway from tooth to brain may help researchers devise better treatments for acute tooth pain, such as cavities or infections, and more-chronic conditions, DaSilva says. One such condition is phantom pain that persists in the mouth after a tooth has been removed.

Image: assbach/flickr

Obama Lays Out New Vision for Asteroid, Mars Trips

Posted: 16 Apr 2010 01:45 PM PDT


Speaking at NASA's Kennedy Space Center April 15, President Obama outlined a new plan for the space agency that would forgo sending astronauts back to the moon, but would send humans to an asteroid in 2025 and into orbit around Mars a decade later.


The strategy would rely on private aerospace companies to ferry crew and supplies into space. It would also cancel a program known as Constellation, which is aimed at developing a heavy-lift rocket and vehicles to carry astronauts back to the moon, in favor of pursuing a new rocket that would take humans beyond well beyond that destination.

"I am very happy about the introduction of new innovative commercial approaches in human space flight, because we've been trapped into a very bad cul-de-sac for 40 years," says planetary scientist and former NASA associate administrator for science Alan Stern of the Southwest Research Institute in Boulder, Colo. Stern predicts that Congress is likely to approve Obama's plan.

In Obama's blueprint, NASA would get an additional $6 billion over the next five years to begin developing new space technologies, refocusing its efforts away from designing space transportation vehicles. The plan would, however, keep plans to develop the Orion crew vehicle, which would be the only U.S. space transport vehicle once the shuttle is retired later this year. And in 2015, the agency would evaluate plans for a rocket that would carry astronauts into deep space.

Early next decade, Obama said, "a set of crewed flights will test and prove the systems required for exploration beyond low Earth orbit," culminating in the first human journey to an asteroid in 2025.

Journeys to Mars orbit in the mid-2030s would be followed by a landing on Mars, "and I expect to be around to see it," the president told the cheering crowd.

Obama said he recognized that some experts have called it unwise to rely on the private sector for ferrying crews and supplies into space, but "by buying the services of space transportation rather than the vehicles themselves, we can continue to ensure rigorous safety standards are met but will also accelerate the pace for innovations as companies, from young start-ups to established leaders, compete, design, build and launch new ways of carrying people and materials into space."

Norm Augustine, who chaired a committee that last year criticized the Constellation program and NASA funding, spoke after Obama. The former chairman and chief executive officer of the Lockheed Martin Corp. said the agency "was trapped in low Earth orbit" hauling cargo instead of trying to reach a loftier destination in space. He added that if the agency didn't rely on U.S. companies to take astronauts into space, it would have no alternative but to rely on Russians.

Obama criticized the Bush administration's program to send astronauts back to the moon and then eventually on to Mars as a blueprint that lacked both funding and specific goals. "There are also those who have criticized our decision to end parts of Constellation as one that will hinder space exploration beyond low Earth orbit," Obama said."But by investing in groundbreaking research and innovative companies, we have the potential to rapidly transform our capabilities."

Space-policy analyst Howard McCurdy of American University in Washington, D.C., says he doesn't see much difference in adherence to timetables and goals between Bush's plan and that of Obama's. But he says he's intrigued by Obama's willingness to "leapfrog" over smaller goals. According to McCurdy's interpretation, Obama is telling the public "if we go the moon and concentrate on completing project Constellation, it's going to be a dead end, but if we set our sights a little further out and skip those intermediate steps, we can have real accomplishments."

It's a high-risk proposition, says McCurdy, "but as long as NASA has a monopoly on space transportation, it's going to be like the airline industry in the 1960s — high quality and very expensive.

"The real key in all of this is the ability of the private sector to do what NASA has been unable to do for about the last 30 years, and that is cut the cost to low Earth orbit. As long as NASA was spending $4 billion to $5 billion a year flying the space shuttle, [the agency] was going nowhere," McCurdy says.

Image: NASA

Photos Surface of the Day Einstein Died

Posted: 16 Apr 2010 01:16 PM PDT


Ralph Morse, an ambitious photojournalist for Life magazine, covered a funeral in New Jersey on April 18, 1955. Now, 55 years later, is finally publishing the pictures he took that day, during the funeral and cremation of Albert Einstein.

Einstein had died of heart failure at age 76 earlier that morning at Princeton Hospital. The hospital's pathologist removed his brain for preservation and study, in the hopes that scientists could figure out how he got so smart.

Post-autopsy the body was moved briefly to a funeral home, then to a crematorium in Trenton, New Jersey, for a short service and cremation. (His ashes were scattered later on the grounds of Princeton's Institute for Advanced Study.)

Morse followed the mourners as they returned to Einstein's house at 112 Mercer Street in Princeton. He was the only photographer on the scene during these moving moments.

But when he returned to the Life offices, Morse learned that the magazine wasn't going to publish the pictures. At the request of Einstein's son, Hans Albert Einstein, Life respected the family's privacy while they mourned. Morse and the magazine both forgot about the pictures until recently.

Photo: Einstein's body is moved from the hospital to a funeral home in Princeton.
Ralph Morse/TIME & LIFE Pictures

Oldest Martian Meteorite Not as Old as Thought

Posted: 15 Apr 2010 02:47 PM PDT


The Allan Hills meteorite, named for the site where it was found in Antarctica, was once thought to contain fossil traces of life. That idea has been mostly dismissed, and now the rock also appears to be not quite as old as previously thought.


The oldest known Martian meteorite isn't so old after all. Though it's still the oldest chunk of Mars scientists have ever found, new research suggests the Allan Hills meteorite — officially known as ALH84001 — is about 400 million years younger than previously estimated.

A new analysis published in the April 15 Science pegs the meteorite's age at a mere 4.091 billion years. Previously the meteorite was commonly accepted to have formed 4.51 billion years ago, when the planet's surface was still solidifying out of its primordial magma ocean. But the new age indicates the rock would have formed during a later, chaotic period when Mars was being pummeled by meteorites that fractured and shocked the planet's solid surface.

The Allan Hills meteorite has been a lightning rod for controversy since scientists announced in 1996 that it might hold fossils of Martian bacteria. The scientific community has since mostly abandoned that idea, as one by one every line of evidence for life has been given a non-biological explanation.

"People usually ask me about the life aspect, and I'm so sick to death of that," says Allan Treiman of the Lunar and Planetary Institute in Houston, who was not involved in the new work. Treiman and others now believe that what once looked like fossils is actually rock that was shaped by ordinary geological activity.

The previously accepted age of 4.51 billion years old was calculated in 1995 by measuring radioactive isotopes of samarium and neodymium. Radioactive elements decay from a "parent" isotope (in this case, samarium) to a "daughter" isotope (neodymium) at a set rate. By comparing the amount of the parent element to the daughter element, scientists can infer how long a rock has been around.

"To understand how the Martian mantle has evolved, it's critical to get samples that are old, to see what the mantle sources were early in the planet's history," says Thomas Lapen of the University of Houston, a coauthor of the new study. "This is the only sample in that age range."

Lapen and his colleagues used radioactive isotope dating to calculate the age of the meteorite, using different elements than the 1995 analysis did. Lapen says that the elements used back then were mostly found in minerals called phosphates, which succumb relatively quickly to weathering and geological processes. Like hair dye or a fake ID, weathering could disguise the rock's age in some ways, but not so thoroughly that more reliable indicators are obscured.

"If it's subject to weathering, the phosphate would be the first to be disturbed," Lapen says. "Then ages dependent on the phosphates are altered."

Instead of elements found in phosphates, Lapen's group used lutetium and hafnium, elements that are mostly found in more change-resistant components of the rock. This method showed that the meteorite is just 4.091 billion years old.

Surprisingly, the researchers also found that several younger meteorites have essentially the same composition as the Allan Hills meteorite, meaning some of the same basic geologic processes have been at work on Mars for almost its entire history.

"That connection is perhaps the most amazing outcome of this research," Lapen says. "Mars is a very steady state planet. Igneous processes were happening the same way four billion years ago as they are happening right now."

The new age places the rock's birth date right at a period in the solar system's history when all of the inner planets were being bombarded with meteorites. That could clear up some confusion about the meteorite, Treiman says. Parts of the rock show signs of having been melted and reformed a second time since its birth, which would have been tough to explain if the rock were all original Martian crust.

"That had been a bit of a problem," Treiman says. "You'd have to do whatever mantle processing, whatever happened on the planet, before this rock came to be formed. There's not a lot of time for that."

Image: NASA.

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Networked Networks Are Prone to Epic Failure

Posted: 15 Apr 2010 11:16 AM PDT


Networks that are resilient on their own become fragile and prone to catastrophic failure when connected, suggests a new study with troubling implications for tightly linked modern infrastructures.

Electrical grids, water supplies, computer networks, roads, hospitals, financial systems –all are tied to each other in ways that could make them vulnerable.

"When networks are interdependent, you might think they're more stable. It might seem like we're building in redundancy. But it can do the opposite," said Eugene Stanley, a Boston University physicist and co-author of the study, published April 14 in Nature.

Most theoretical research on network properties has focused on single networks in isolation. In reality, many important networks are tied to each other. Anecdotal evidence — the crash of communications networks (.pdf) in lower Manhattan after 9/11, the plummeting of markets around the world after the Black Monday stock market collapse of 1987 — hints at their fragility, but the underlying mathematics are largely unexplored.

The Nature researchers modeled the behavior of two networks, each possessing what's known as "broad degree distribution": A few nodes have many connections, some have an intermediate amount of links and many have just a few. Think of the networks as having only a few branches, but many leaves. On their own, such networks are known to be stable. A random failure is likely to disable a leaf, leaving the rest of the network's connections mostly intact.

In the new study, the researchers connected two of these networks. While many node failures were required to crash the networks when they were independent, a few failures crashed the networks when they were linked.

"Networks with broad distributions are robust against random attacks. But we found that broad interconnected networks are very fragile," said study co-author Gerald Paul, a Boston University physicist.

The interconnections fueled a cascading effect, with the failures coursing back and forth. A damaged node in the first network would pull down nodes in the second, which crashed nodes in the first, which brought down more in the second, and so on. And when they looked at data from a 2003 Italian power blackout, in which the electrical grid was linked to the computer network that controlled it, the patterns matched their models' math.

That broad networks could be so fragile is surprising, but even more important is how rapidly the crash happened, with sudden catastrophic collapse instead of a gradual breakdown, said Indiana University informaticist Alessandro Vespignani in a commentary accompanying the paper. "This makes complete system breakdown even more difficult to control or anticipate than in an isolated network," he wrote.

According to Raissa D'Souza, a University of California, Davis mathematician who studies interdependent networks, the findings are "a starting point for thinking about the implications of interactions."

D'Souza hopes such research will pull together mathematicians and engineers. "We now have some analytic tools in place to study interacting networks, but need to refine the models with information on real systems," she said.

Research into linked systems could help engineers build more resilient networks, or identify existing weaknesses. At the very least, they stress the importance of preparing for sudden, catastrophic failures. "We must recognize the possibility of big disasters, and take steps to prepare," said Stanley, noting how unprepared political and economic leaders were for the financial collapse that triggered the current recession.

"These stories underscore that when trouble happens, we're surprised. But we shouldn't be," said Stanley.

Image: From left to wright, a failure cascades through an Italian power network (overlaid on the map) and the internet nodes that depend on it (above the map)./Nature.

See Also:

Citations: "Catastrophic cascade of failures in interdependent networks." By Sergey V. Buldyrev, Roni Parshani, Gerald Paul, H. Eugene Stanley & Shlomo Havlin. Science, Vol. 328 No. 5976, April 15, 2010.

"The fragility of interdependency." By Alessandro Vespignani. Science, Vol. 328 No. 5976, April 15, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Icelandic Volcano’s Ash Plume as Seen From Space

Posted: 15 Apr 2010 10:40 AM PDT


A NASA satellite captured an image of the ash plume from the Eyjafjallajokull volcano's Wednesday eruption. We can see the ash plume from the event sweeping east just north of the United Kingdom en route to Norway.

The plume has disrupted air travel in western Europe, The New York Times reports, because of (well-founded) fears that the silicates in the ash could turn into molten glass inside planes' jet engines.

"The shutdown, among the most sweeping ever ordered in peacetime, forced the cancellation of thousands of flights and left airplanes stranded on the tarmac at some of the world's busiest airports as the rolling cloud — made up of minute particles of silicate that can severely damage airplane engines — spread over Britain and toward continental Europe," the Times reported.

NASA's TERRA imager has had its eye on the Icelandic volcano since it erupted to life March 20 after more than 190 quiet years.


A closeup of the volcano taken on March 24.

See Also:

WiSci 2.0: Alexis Madrigal's Twitter, Tumblr, and green tech history research site; Wired Science on Twitter and Facebook.

Why NASA Is Sending a Robot to Space That Looks Like You

Posted: 15 Apr 2010 10:13 AM PDT


A humanoid robot will visit space for the first time in September aboard the Space Shuttle Discovery, NASA announced Wednesday.

The Robonaut 2, which was co-developed by NASA with General Motors, will serve as an assistant to the humans on board the International Space Station, using the same tools developed for astronauts.

While plain old robots, such as the Mars Phoenix Lander, are a major part of NASA's operations, humanoid robots are a different story. There is significant science-fiction appeal to the idea of humanoid robotic helpers for humans, but does the idea makes more than literary sense? Yes, said Jeffrey Hoffman, an MIT aerospace professor and former astronaut.

"I'm a very strong believer in human-robotic interaction. You can build up a synergy to accomplish what neither humans nor robots could accomplish on their own," Hoffman said. "That's the inspiration behind Robonaut."

Many successful robots, like Kiva's product-distribution robots or the military's little helpers look nothing like humans. And some space researchers like MIT historian and policy analyst David Mindell don't think humanoid robots are a very good idea. But the International Space Station may be the perfect place for a humanoid robot.

"It's incredibly important that Robonaut have a humanoid form factor because he's being sent into space, and it's incredibly expensive, and he has to do a lot to pay himself off," said former roboticist Daniel Wilson (author of How to Build a Robot Army). "It has to be able to pick up any tool that an astronaut could use and go outside."

Wilson argued that space was a uniquely good environment to showcase both the versatility of people and a general-purpose humanoid robot.

"You can't bring a tool to solve every single problem. There's no way. Astronauts can't haul all that shit up there. It's like, 'I have a screwdriver and my brain, and I need to solve the problem, and I don't know what the problem is before I leave the planet,'" Wilson said. "You can use the humanoid to leverage all those tools."

James Hughes, who studies emerging technologies at Trinity University, suggested that humanoid robots may provide a nice middle ground between hardcore human spaceflight evangelists and those who would rather see robotic missions. Most space watchers feel that the human programs are what drives interest and funding in exploration, while scientific investigation will be driven by robots.

"A humanoid robot splits the difference. You get some of the advantages of both and hopefully it will be a nice compromise between the two," said Hughes. "But it may not satisfy either side."

The Robonaut project began in 1996 and the first version of the bot came out in 2000. In 2006, NASA's Dexterous Robotics Laboratory at Johnson Space Center teamed up with GM to design the new robot.

"It is very safe to say that the United States and NASA possess the state of the art in robotic dexterity," said Nic Radford, the Robonaut deputy project manager. "The ideas are limitless."

The bot will be phased into operation in three stages. First, it'll operate only from a fixed position inside the International Space Station. Then, it'll be allowed to move about inside, and finally within a few years, it will be allowed to do extravehicular activities.

"It's really going more to an autonomous system," Radford said. "Right now, it has a task-based system built up of behaviors. We program in a task and based on the sensory input that it receives, it's able to make decisions on what it's going to do next."

The opportunity to test on the robot in orbit has Radford, Wilson and Hoffman excited.

"This has been a dream of our group for a long time," Radford said.

See Also:

WiSci 2.0: Alexis Madrigal's Twitter, Tumblr, and green tech history research site; Wired Science on Twitter and Facebook.

T. Rex of Leeches Found in Amazon Swimmers’ Noses

Posted: 14 Apr 2010 05:30 PM PDT


A toothy leech found in the noses of Peruvian swimmers has called attention to an unrecognized and gruesome branch on the tree of life.

Dubbed Tyrannobdella rex, "tyrant leech king," the pinkie-finger-sized bloodsucker has a single jaw, with teeth five times longer than those found in any other leech.

Described in a paper published April 14 in PLoS ONE, the first specimen was found by doctors in 1997 in the nose of a 6-year-old boy in San Martin, Peru. He had complained of headaches.


Another specimen was taken that year from a 16-month-old boy in Ayacucho, Peru. A decade later, a third T. rex was taken from the nose of a 9-year-old Peruvian girl who felt a "sliding" sensation in her nose. All had bathed frequently in Amazonian streams.

The habit of invading an orifice and feeding on mucous membranes is known as hirudiniasis, and had been seen in a variety of leech species in the Middle East, Africa and Asia. Scientists assumed these species to be unrelated, regarding their feeding habits "only as a loathsome oddity and not a unifying character for a group of related organisms," wrote the researchers.

But when they took a closer look at these species, the researchers noticed anatomical similarities. Genetic comparisons supported the observation. T. rex and the other mucous-membrane feeders actually belong to a single group. DNA differences between them, combined with known mutation rates, suggest a last common ancestor about 200 million years ago, when dinosaurs rose to Earthly dominance.

An ancestor of T. rex may have swum up the other T. rex's nose.

Images: From PLoS ONE: 1. Close-up of the T. rex jaw at left, and its front sucker at right.
2. Examples of other mucous-membrane–feeding leech species.

See Also:

Citation: "Tyrannobdellarex N. Gen. N. Sp. and the Evolutionary Origins of Mucosal Leech Infestations." By Anna J. Phillips, Renzo Arauco-Brown, Alejandro Oceguera-Figueroa, Gloria P. Gomez, Maria Beltran, Yi-Te Lai, Mark E. Siddall.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.

Cassini Captures First Video of Extraterrestrial Lightning

Posted: 14 Apr 2010 11:45 AM PDT

The Cassini spacecraft has captured lightning flashing in a cloud on Saturn's dark side in a first-of-its-kind video.

Scientists have picked up radio signals for years that indicated that lightning storms happened on the planet, but this is the first time that they were able to see and "hear" the electrical storms at the same time.

"This is the first time we have the visible lightning flash together with the radio data," said Georg Fischer, a radio and plasma wave scientist based at the Space Research Institute in Graz, Austria, in a press release. "Now that the radio and visible light data line up, we know for sure we are seeing powerful lightning storms."

The video was shot over 16 minutes and compressed down into the 10 seconds that you see here. The cloud, which is about 1,900 miles along its longest side, is illuminated by the reflection of Saturn's rings. Each flash is about 190 miles (300 kilometers) across with an energy comparable to the most intense lightning here on Earth. In real time, they lasted for about one second.

The crackling soundtrack to the video is synthetic. It approximates the actual sounds received by Cassini's radio recording instrument, which are above the human hearing range.


Images: NASA/JPL/SSI/University of Iowa

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3-Parent Embryos Could Prevent Disease, But Raise Ethical Issues

Posted: 14 Apr 2010 10:54 AM PDT


Researchers have produced human embryos containing DNA from three people, a biotechnological proof-of-principle with profound medical and ethical implications.

To accomplish this, chromosomes were taken from one zygote — the single cell formed when sperm and egg fuse — and put into a zygote stripped of its original chromosomes, but left with its original mitochondria, which provide each human cell with energy.

As they grew, the resulting embryos contained so-called nuclear DNA — the 25,000 genes responsible for physical and developmental traits — from two traditional parents, and mitochondrial DNA from a third.

The technique is a subtle form of genetic engineering, which many people consider taboo, and raises other ethical dilemmas. It could also allow parents whose progeny would otherwise suffer from deadly mitochondrial diseases to have healthy children. It's been done in mice and monkeys, but not in people.

"Previous work showed that these manipulations were possible. This showed that we can get the development of these embryos up to the blastocyst stage," said Doug Turnbull, a Newcastle University neurologist and co-author of the study, published April 14 in Nature.

Thousands of mitochondria float freely in each human cell, using 17 genes to convert oxygen and nutrients into chemical energy. During reproduction, mitochondria in sperm are destroyed. Only the mitochondria in a mother's egg are passed on.

Malfunctions in aging mitochondria have been linked to a variety of common diseases, including Alzheimer's and cancer, but researchers like Turnbull focus on a subset of rare conditions caused early in life by defective mitochondria. About one in 4,000 children develops a mitochondrial disease by age 10. Such diseases are often debilitating, sometimes fatal and presently incurable.

In recent decades, doctors wondered whether defective mitochondria might be swapped for healthy ones in an embryo. In the last few years, sophisticated reproductive technologies and cell-manipulating tools have made that possible — first with mice, and then with more complex creatures.

Two years ago, Turnbull performed the basic steps of the technique with embryos left over from in vitro fertilization. Last August, other researchers performed a variation of the technique, starting with unfertilized eggs rather than zygotes, on rhesus macaque monkeys.

Of 80 embryos in the the Nature study, again taken from IVF leftovers, eight were sustained for six days, long enough to become blastocysts with about 100 cells.

The technique "introduces some inefficiencies because it's more complicated" to use a zygote, said Shoukhrat Mitalipov, an Oregon Health & Science University reproductive biologist who led the rhesus macaque experiment. Both techniques may ultimately be used, depending on circumstance, he said. But the new results are still powerful.

"This is great. We've been thinking about this for years," said Eric Schon, a Columbia University mitochhondrial geneticist. "That possibility is now closer."

Many steps remain before mitochondria swapping could be considered for humans. Though engineered mice have matured and reproduced normally, the monkeys are just a year old. But while safety is yet to be determined, ethical questions are emerging.

One issue involves the nature of parenthood: Would a mitochondrial donor be a parent? Turnbull compared mitochondria to the power source for a laptop. "All the characteristics of the computer are stored on the computer. We're just changing the battery," he said.

Potentially more tricky is the healthy mitochondria's source. While leftover embryos used in Turnbull's approach are plentiful, eggs used by Mitalipov's technique would need to be donated. Egg donation involves a series of grueling and potentially risky hormone treatments.

Marcy Darnovsky, executive director of the Center for Genetics and Society, worried that the risks of mitochondrial swapping might not be immediately evident. She mentioned intracytoplasmic sperm injection, in which sperm is injected directly into an egg. It's an approved workaround for male fertility, but some studies now suggest an increased risk of birth defects (pdf). "Observers have said that human beings were the guinea pigs," Darnovsky said.

Because mitochondria are inherited, both Turnbull's and Mitalipov's techniques are a type of germline, or heritable, genetic engineering. Many people think altering DNA is fine when changes aren't inherited, as with gene therapy to repair eyes, but troubling when traits are passed on. Fearful of designer babies and long-term health uncertainties, countries like France and Germany have banned germline genetic engineering.

Mitochondrial swapping might seem less controversial than regular genetic engineering, because it involves metabolism rather than obvious physical traits. "On the other hand, when embryo manipulations for heritable changes start being done, even with the best intentions, we're on slippery ground," said Darnovsky.

"I think this strategy for handling mitochondrial disease is fascinating, important and ethical, but it certainly crosses the line of engineering genes," said Art Caplan, director of the University of Pennsylvania's Center for Bioethics. "It's a quiet intrusion, but it crosses a line that a lot of people said shouldn't be crossed."

Doug Wallace, a mitochondrial geneticist at the University of California, Irvine, framed the ethics differently. "Is it fair for society to make it impossible for a woman who has a high percentage of mutant mitochondrial issues to have a healthy baby? That's what I'm confronted with in my clinic," he said. "There's an ethic of what's best for the patient."

"For these families, there isn't a cure," said Turnbull. "That's our motivation."

Image: A nucleus is transferred into a recipient zygote./Nature.

See Also:

Citation: "Pronuclear transfer in human embryos to prevent transmission of mitochondrial DNA disease." By Lyndsey Craven, Helen A. Tuppen, Gareth D. Greggains, Stephen J. Harbottle, Julie L. Murphy, Lynsey M. Cree, Alison P. Murdoch, Patrick F. Chinnery, Robert W. Taylor, Robert N. Lightowlers, Mary Herbert, & Douglass M. Turnbull. Nature, Vol. 464 No. 7291, April 15, 2010.

Brandon Keim's Twitter stream and reportorial outtakes; Wired Science on Twitter. Brandon is currently working on a book about ecological tipping points.