80beats

Found: Dino-Munching Crocodiles Who Swam in the Sahara

Brett Israel — Fri, 20 Nov 2009 21:25:55 +0000

A thrilling set of ancient crocodile fossils have been unearthed in northern Africa. A “saber-toothed cat in armor” and a pancake-shaped predator are among the strange crocodile cousins whose bones have been found beneath the windswept dunes of the Sahara, archaeologists say [National Geographic News].

At a news conference organized by the National Geographic Society, which sponsored the research, scientists announced that the fossils represent 5 species; 3 new species and 2 that were previously known. These ancient croc ancestors, known as crocodilyforms, are unlike any crocodiles encountered in the Northern Hemisphere, according to the research team. Their findings are detailed in the journal ZooKeys.

The crocs were spectacularly diverse, and included a species that ate dinosaurs, two that grew up to 20 feet long, and two that had long legs for quick movement on land but also had long tails for swimming. The three new species are:

• BoarCroc (Kaprosuchus saharicus), a 20-foot meat-eater. It used its snout for ramming and three sets of dagger-shaped fangs for slicing dinosaurs it ate.

• PancakeCroc (Laganosuchus thaumastos): a 20-foot-long, squat fish-eater with a 3-foot long flat head with spike-shaped teeth.

• RatCroc (Araripesuchus rattoides), a 3-foot-long plant and grub eater with buckteeth used for digging [Chicago Sun-Times].

The two previously known species are nicknamed DuckCroc, a three-foot long, long-legged croc that feasted on fish and frogs, and DogCroc, another small and lanky croc that mostly ate plants and grubs.

“These species open a window on a croc world completely foreign to what was living on northern continents,” [researcher Paul] Sereno said of the unusual animals that lived 100 million years ago on the southern continent known as Gondwana [AP]. From the fossils, researchers believe that at least some of these crocs were equally at home on land and in the water. They roamed what is now Morocco and Niger at a time when the landscape was covered with lush plains and broad rivers. The crocs included meat eaters that could have devoured man—if any humans had existed at the time.

From studying the fossil skulls, the researchers made predictions about the crocs’ brain power. The scientists studied the animals’ brains by creating digital and physical casts from CT-scans, 3D X-rays. Both DogCroc and DuckCroc had broad, spade-shaped forebrains that looked different from those of living crocodiles [Telegraph]. Researcher Hans Larsson, who discovered the fossils of BoarCroc and PancakeCroc, said the brain models suggest these crocs had superior brain power compared to their modern ancestors, possibly because chasing after your meals on land requires more energy than milling around in the water waiting for your food to arrive.

Serano, the team leader, has a penchant for discovering the ancient crocs. He discovered SuperCroc—the largest of them all—nine years ago in the same region. His latest findings are the subject of “When Crocs Ate Dinosaurs,” which airs on the evening of Saturday, November 21, on the National Geographic Channel.

Image: Mike Hettwer, courtesy National Geographic

Ripped From the Journals: The Biggest Discoveries of the Week

Eliza Strickland — Fri, 20 Nov 2009 19:16:28 +0000

Proceedings of the National Academy of Sciences, November 17
When is a goat like a reptile? When it’s cold-blooded, slow-moving, and fond of sitting on warm rocks. Researchers have discovered a bizarre dwarf goat species that lived on the Spanish island Majorca, but that went extinct when human hunters arrived on the island about 3,000 years ago. The study says that the goat’s cold-blooded ways allowed it to survive on the resource-scarce island, as it could match its growth and metabolism to the available food supplies, but its sluggish movements made it easy prey for humans. In medical news, a research team investigating the dramatic failure of an HIV vaccine trial, in which vaccinated people seemed to be at higher risk of infection, has proposed a new theory for the failure. The study suggests that the common cold virus, which was used in the vaccine to carry HIV material around the body so the immune system could learn to recognize HIV, may have been at fault. The vaccine didn’t cause infection. But for people who have previously been exposed to this cold virus, its appearance may have triggered a gathering of immune cells called CD4 T-cells which were ready to fight it off. But those are the cells that HIV infects, so if people were then exposed to the HIV virus, the virus would have been presented with a ready availability of targets. Finally, an interesting study captured a snapshot of evolution-in-action on the Galapagos islands. A husband and wife team of evolutionary biologists is documenting what appears to be the emergence of a new species among Galapagos finches, the same birds that inspired Charles Darwin’s theory of evolution.

New England Journal of Medicine, November 19
Who can resist a story about brain-eaters that also has valuable medical and evolutionary lessons? A NEJM study describes a tribe in Papua New Guinea that used to engage in ritualistic cannibalism; when a member of the tribe died, the others ate the person’s brain as a mark of respect. The practice became a problem in the early 20th century, when some people became infected with a disease similar to mad cow disease and its human variant, Creutzfeldt Jakob disease. These fatal diseases are caused by misfolded proteins in the brain, so when the Fore people of Papua New Guinea consumed an affected brain the disease quickly spread. But a new study of living Fore people revealed that many are immune to the disease, which suggests that evolution has been acting quickly: Those people who had no resistance to the disease died off quickly, while people with resistance lived and multiplied. Researchers also hope to study the Fore people for clues on how to treat or prevent such diseases.

Science, November 20
A fascinating study brought new insight into the disappearance of North America’s prehistoric megafauna, via a study of a fungus present in their mega-dung. The fungus releases a spore that is preserved in sediment samples, which researchers can analyze to determine how prevalent the great beasts were throughout history. The new analysis suggests that megafauna like mastodons, mammoths, and sabre-toothed tigers began a slow decline around 15,000 years ago and vanished completely about 1,000 years later. This suggests that their extinction was not a result of an asteroid or comet that is thought to have exploded over North America much later. It also takes the blame off the Clovis people, who were thought to be North America’s first settlers, but who didn’t establish themselves until about 13,300 years ago. Some researchers have suggested that the Clovis people hunted mammoths and the like into extinction. While the new study makes a good argument, it’s unlikely to persuade all proponents of alternate theories–expect rebuttals to follow. Another study revealed the results of a four-year effort to map the genome of corn. The task turned out to be surprisingly complex, as the corn genome has 12,000 more genes than the human genome, but the resulting data has already helped scientists understand how maize was domesticated, and should help agricultural researchers increase the efficiency of corn crops.

Journal of the American Medical Association, November18
Upper-crust ancient Egyptians weren’t so different from modern Americans in one way: a new study that X-rayed 20 Egyptian mummies found signs of clogged arteries and heart disease in 16 of them. Since only the Egyptian elite were mummified, it’s impossible to say if cardiovascular problems were widespread in ancient Egypt. But the researchers note that the elite often dined on rich dishes such as beef, mutton, and cakes with honey and butter, and suggest that this fatty diet may have contributed to heart disease among the nobility.

Nature, November 19
In another warning bell regarding global warming, a study found that the world’s oceans are absorbing less globe-warming carbon dioxide than they used to. Until about the 1980s, researchers say, the absorption rate kept pace with increasing greenhouse gas emissions. But since then the intake rate has slowed, due to a gradual change in the oceans’ chemistry. The increased load of CO2 in the seawater is changing the pH balance of the oceans and making them more acidic, which then limits the amount of CO2 they can sop up. The results are troubling, because they indicate that even more greenhouse gases will remain in the atmosphere.

Star Trek-Style “Phaser” Paralyzes Worms With a UV Blast

Andrew Moseman — Fri, 20 Nov 2009 18:09:34 +0000

Feel like teaching a lesson to that pinhead-sized worm that’s been bothering you? According to a study in the Journal of the American Chemical Society, a material called dithienylethene plus a blast of UV light can stop a worm in the midst of its worming, rendering it temporarily paralyzed.

The researchers fed a light-sensitive material — a “photoswitch” known as dithienylethene — to the transparent worms. When exposed to ultraviolet rays, the molecule turned blue and the worms became paralyzed. Using visible light instead made the chemical turn colorless and the paralysis ended [LiveScience]. Scientists aren’t sure why the transparent nematodes became paralyzed, but they know dithienylethene changes shapes and suspect it interferes with the worm’s energy-producing metabolic pathways. Repeated cycles of UV-induced paralysis actually killed some of the worms.

Unsurprisingly, news of this worm stun-gun led to longing for Star Trek-style phasers, and the scientists, though skeptical, were good sports about it. As lead researcher Neil Branda said tactfully: “I’m not convinced there’s a legitimate use of turning organisms on and off in terms of paralysis, but until somebody tells me otherwise, I’m not going to say that there isn’t an application” [BBC News].

But while phasers remain a fantasy, light-activated materials certainly have a future in medical research. Light-activated drugs could be used to activate tumour-killing drugs once they reach a particular location in the body. Similar chemicals have been used before, but have required a steady supply of light – often harmful UV bandwidths – to stay active. The new compounds, known as diarylethenes, could be more useful because they can be switched on and off with a single light pulse, Branda says [New Scientist].

Image: Wiki Commons / Yonatanh

IBM’s Billion-Neuron Simulation Can Match a Cat’s Brainpower

Andrew Moseman — Fri, 20 Nov 2009 15:52:56 +0000

An artificial brain as powerful as a human’s remains a distant goal, but scientists are inching closer. This week IBM announced that by using a brain-simulating algorithm called BlueMatter, researchers created an artificial brain simulation that packs more brainpower than a cat.

Researchers used an IBM supercomputer at the Lawrence Livermore Lab to model the movement of data through a structure with 1 billion neurons and 10 trillion synapses, which allowed them to see how information “percolates” through a system that’s comparable to a feline cerebral cortex [San Jose Mercury News]. The team’s previous effort two years ago, modeled after a rat brain, simulated only about 55 million neurons.

The staggering surge in computing power has engineers like IBM’s Dharmendra Modha drooling over the possibilities for more brain-like computers. By reverse engineering [the] cortical structure, Modha says, researchers could give machines the ability to interpret biological senses such as sight, hearing and touch. And artificial machine brains could process, intelligently, senses that don’t currently exist in the natural world, such as radar and laser range-finding [Popular Mechanics].

It should come as no surprise that the design suggests such military applications, as DARPA provided much of the funding. But like the Internet and other technologies originally developed for the military, BlueMatter’s abilities could lead in a multitude of directions. “As our digital and physical worlds collide, there is a tsunami of information,” Modha said. “There is a need for a new kind of intelligence that can sort through, prioritize and extract the most important information, much like how the brain deals with sight, sounds, tastes, touch and smell” [San Jose Mercury News].

Image: IBM Almaden research lab, Stanford University

Spores in Mastodon Dung Suggest Humans Didn’t Kill Off Ancient Mammals

Brett Israel — Fri, 20 Nov 2009 12:00:53 +0000

A fungus found within ancient mammoth dung is providing scientists with clues about how the large ancient mammals collectively known as megafauna went extinct. The fungus, Sporormiella, produces spores in the dung of large herbivores. These are then preserved in the layers of mud and can provide an index of the number of these animals, or megafauna, that roamed the environment at a particular time [BBC News]. For a new study, researcher Jacquelyn Gill collected and analyzed spores in sediment samples from an Indiana lake and several sites in New York.

From Gill’s analysis, published in the journal Science, she concluded that North American megafauna began a slow decline around 15,000 years ago and vanished about 1,000 years later. The data suggests megafauna started going extinct much earlier than previously though, which basically wipes out two theories of their extinction.

There are several theories surrounding the extinction of North American megafuana, but there are a lot more questions than answers. Much of the uncertainty surrounding the extinction of the North American megafauna, which includes mastadons, saber-tooth tigers and giant ground sloths, is due to a scarcity of evidence and difficulty pinning down the timing of events. Several major events occurred around the same time the animals disappeared: Major environmental upheaval associated with the end of the Ice Age; an asteroid explosion over North America; and the arrival of man [Wired.com]. But the new data points to an extinction culprit other than an asteroid or comet impact, because the impact is believed to have occurred long after the megafauna began their decline.

If humans were responsible for the extinction, it would have to be settlers that came along before the Clovis people, which is another debate in itself. The Clovis culture is thought to have been the first civilization to take hold in North America around 13,300 years ago–after the bulk of the megafauna extinctions, according to the new analysis. But some researchers believe that earlier settlers walked the land before the Clovis people, and could have hunted the mastodons and mammoths. The new study adds crucial info to the fossil record, but it is likely to kindle, rather than quench, the debate over megafauna extinction.

Image: Barry Roal Carlsen, University of Wisconsin-Madison

New Guinean Cannibals Evolved Resistance To Mad Cow-Like Disease

Andrew Moseman — Thu, 19 Nov 2009 20:24:59 +0000

Members of a tribe in Papua New Guinea has evolved resistance to a affliction similar to mad cow disease (called Creutzfeldt Jakob disease, or CJD, in people). How did they do it? Cannibalism, according to a study in the New England Journal of Medicine.

The Papua New Guinea variant is called kuru, and it was a disaster there. When members of the Fore people in Papua New Guinea died, others would eat the dead person’s brain during funeral rituals as a mark of respect. Kuru passed on in this way killed at least 2500 Fore in the 20th century until the cause was identified in the late 1950s and the practice halted [New Scientist].

The scientists compared DNA samples of about 3,000 living Fore people, some of whom had participated in the old rituals, to 152 samples of stored DNA from Fore that kuru killed. They looked at the genes for prions, ordinary brain proteins that take on a misfolded shape in prion disease such as CJD and kuru. They found a mutation called G127V that protected people from kuru. Only people who ate brains and survived have it, they found [Reuters].

The discovery excited scientists with the possibility of understanding and even treating other prion diseases, like CJD. And British neurologist John Hardy exemplified the scientific glee at seeing human evolution happen in such a short time. “It’s fantastic demonstration of natural selection… In Papua New Guinea kuru became the major cause of death, so there was a clear survival advantage and the selection pressure was enormous” [BBC News].

Image: D. Carleton Gajdusek

NASA Invites You to “Be a Martian” & Explore the Red Planet’s Terrain

Eliza Strickland — Thu, 19 Nov 2009 18:05:02 +0000

With NASA’s manned space flight program in tumult, it’s an open question when/if human boots will tramp on Martian soil. But the space agency has provided a virtual way for humans to explore the red planet, with its new “Be a Martian” program.

The online project, a collaboration between NASA and Microsoft, enlists the power of crowdsourcing. Users are invited to sort through the hundreds of thousands of photos of Mars that have been sent back by rovers and orbiters. To convince people to spend hours pouring over pictures of dusty Martian landscapes, two tasks have been set up as games where participants can win points and badges. One game asks people to count craters in photos of Mars; the other asks people to match small, high-res photos of the Martian surface with their corresponding locations on a low-res photo taken from a higher altitude [Seattle Post-Intelligencer]. (You’ll need to have Microsoft’s Silverlight application for the games and videos on the site to work.)

By enlisting citizen scientists, NASA hopes to both interest students in space careers and to make real progress in Martian research. “We really need the next generation of explorers,” says Michelle Viotti, from the agency’s Jet Propulsion Laboratory, which oversees Mars missions. “And we’re also accomplishing something important for Nasa. There’s so much data coming back from Mars. Having a wider crowd look at the data, classify it and help understand its meaning is very important” [BBC News].

Image: JPL / Microsoft

Computer Glitch Delays Airline Flights Around the Country

Andrew Moseman — Thu, 19 Nov 2009 16:14:56 +0000

Air travelers around the country saw their flights delayed this morning, thanks to a computer glitch. The problem, which occured [sic] in the Atlanta-based computer system that provides data about flight plans, has forced air controllers to input the information manually, said Arlene Salac, FAA spokeswoman in New York [Reuters].

The Federal Aviation Administration tried to assure travelers that the problem wasn’t a safety concern; rather it fouled up ground stops and caused delays. The problems began a little after 5 a.m. Eastern time, and hit Atlanta’s busy airport the hardest. One passenger said that a Delta Air Lines gate agent had announced that the glitch prevented pilots from accessing flight plans, the Atlanta Journal-Constitution reported [The New York Times].

The computer problem has been fixed, though FAA spokeswoman Kathleen Bergen said she doesn’t know how many flights have been affected [MSNBC]. And today’s glitch was the second such one in 15 months.

Image: flickr/ eschipul

Scientist Smackdown: Are a Sprinter’s Prostethic Legs an Unfair Advantage?

Andrew Moseman — Thu, 19 Nov 2009 15:59:16 +0000

If you read this blog last week, you might have seen us cover a study suggesting that South African sprinter Oscar Pistorius ought to be allowed to compete in the same track and field events as everyone else because his prosthetic legs confer no advantage over a sprinter with biological legs. But if you saw a study cited by the Associated Press and many other publications yesterday, you might think that Pistorius would soon be banned from competitions, because his “blades” let him swing his legs far faster than even the world’s fastest man, Usain Bolt. So what the heck is going on?

The AP’s study isn’t actually a “study,” per se. Rather, what the Journal of Applied Physiology published was a point-counterpoint (pdf), now freely available for anyone to read. In in, Peter Weyand and Matthew Bundle argue that Pistorius’ prosthetics are a huge advantage, particularly in what matters most: how fast he can move his legs. Weyand and Bundle say that the lightweight blades allow Pistorius “to reposition his limbs 15.7 percent more rapidly than five of the most recent former world-record holders in the 100-meter dash” [AP].

There is, however, a counterpoint to this argument in the journal piece that yesterday’s news reports neglected, coauthored by Alena Grabowski of the MIT Media Lab (who led the research on Pistorius’ blades that 80beats covered last week). Her team has found that the limiting factor determining an athlete’s top speed was how hard the foot or prosthesis hit the ground. Their study showed this “ground force” was around 9% lower in the prosthetic limb versus the unaffected leg [The Guardian]. Grabowski’s research focused on professional runners with only one prosthetic leg.

No matter, Weyand and Bundle say in a rebuttal to the counterpoint: because Pistorius swings his legs so quickly (about .28 seconds per leg, as opposed to the .36 seconds of world-class sprinters with biological legs), he needs 20 percent less ground force than an ordinary runner would to maintain the same speed. Weyand told DISCOVER that the MIT team’s research is probably correct about speed and power when it comes to runners with only one prosthetic. “One limb can’t go faster than the other,” or the runner would go in a circle. But a runner like Pistorius with two prosthetics can learn to swing both legs at the “off-the-charts” speed of .28 seconds, he says, gaining a clear advantage.

Grabowski was understandably miffed at her side’s counterargument being left out of news reports. “We’re all sort of shaking our heads,” she said. She also questioned the validity of Weyand and Bundle’s findings, saying in an email to DISCOVER that they represent an opinion and not a peer-reviewed study, that they don’t consider the starting blocks and turning inherent in a 400-meter race, and Weyand and Bundle’s assertion that Pistorius’ blades take 10 seconds off his 400-meter time “is ridiculous and not based on data.”

But, Weyand tells DISCOVER, he and Bundle got their data during direct observations of Pistorius last year, during the time he was attempting to qualify for the Beijing Olympics. At that time they arrived at the same kind of conclusion Grabowski’s side has arrived at now—that the sprinter ought not be banned. The reason for this odd twist in the story, Weyand says, is that he and Bundle were brought in by Pistorius’ law firm during a hearing last May on the question of whether to overturn a ban on Pistorius, but the hearing could only consider the evidence used to enact the ban in the first place. So, Weyand tells DISCOVER, he and Bundle’s were advocating analysis suggested the ban be overturned because its basis was shoddy insufficient scientific evidence, and at the same time their own studies convinced them that he did have a clear advantage.

To make this affair even stranger, both sides—Weyand and Bundle’s team, and Grabowski’s—all co-authored a less controversial paper earlier this year in the same journal. However, Bundle tells DISCOVER, they left the question of advantage or no advantage out of that paper because they couldn’t agree, and published this point-counterpoint instead. “The comparisons and analysis that Peter and I present in the point-counterpoint are novel, in part because our co-authors prevented them from being included in the manuscript that appeared in June,” he says. As for peer review, Bundle says his argument did receive this treatment, because the journal’s standards consider the editors’ approval of an article to be an appropriate review.

This scientist smackdown isn’t going away: Grabowski told DISCOVER she would issue a press release in response to Weyand and Bundle’s, and continue her prosthesis research. Though if there’s one thing both sides can agree on, it’s that Pistorius is a remarkable athlete, advantage or not. “What he does as an athletic feat is really an amazing thing,” Weyand says.

Related Content:
80beats: Prosthetic Legs Aren’t Better Than the Real Thing… Yet
80beats: Scientist Smackdown: All Our Stories of Lively Scientific Debate
80beats: Toddler Gets a Telescoping, Prosthetic Arm Bone That Grows With Him
Science Not Fiction: Dr. Terminator: The Prosthetics Designer Who Makes Sci-Fi Sculptures

Image: flickr/Elvar Freyr

Starfish Prepare for Hot Conditions by Taking a Long, Cold Drink

Brett Israel — Thu, 19 Nov 2009 11:22:15 +0000

Like humans, sea stars enjoy lounging on the shore during the hot summer months. But when they get too hot, they can’t run for shade, so they have a back-up plan—fattening themselves with cold ocean water before the tide recedes, according to new research published in the journal The American Naturalist. This finding shows that sea stars, or ochre starfish, aren’t as helpless as previously thought. The sea stars are likely cued during low tide that it’s a hot day, the researchers say, and that signals them to soak up more water during the next high tide. “It would be as if humans were able to look at a weather forecast, decide it was going to be hot tomorrow, and then in preparation suck up 15 or more pounds of water into our bodies,” said study researcher Brian Helmuth [LiveScience]. Talk about staying hydrated.

The researchers first studied starfish in an aquarium using heat lamps to simulate a scorching summer day, an infrared camera to measure their internal temperatures, and a scale to weigh the sea stars and determine how much water they had absorbed. The researchers say the amount of water a starfish absorbs can decrease its body temperature by almost 4 degrees Celsius. But researcher Sylvain Pincebourde is concerned that this novel strategy may have limitations in a rapidly changing world…. As oceans warm together with air temperature the thermoregulatory mechanism used by the starfish will cease to work, he warns. “The colder the sea water, the more it is able to lower its body temperature. The efficiency of this thermoregulation strategy therefore might be annihilated by ocean warming” [BBC News]. Yet another reason to get a handle on global carbon emissions.

Image: flickr / laszio-photo

CO2 Emissions Are Rising. Or Falling. Actually, It’s Both.

Andrew Moseman — Wed, 18 Nov 2009 21:20:38 +0000

This week in Nature Geoscience, a cadre of scientists going by the name Global Carbon Project will publish a meta-analysis of global carbon emissions. The study led to headlines like, “Global CO2 emissions to drop 2.8 pct in ‘09: report,” and many others more in the ominous vein of “Earth ‘heading for 6C (6 degrees Celsius)’ of warming.” So how did both headlines come from the same study?

This year’s dip is correct: “In 2009, it is likely that the global financial crisis will cause global emissions to actually fall by a couple of percent,” said Michael Raupach, co-author of the report and co-chair of the Global Carbon Project [Reuters]. But, he says, the carbon cut will be short-lived if the recession ends.

In that case, the researchers say, the world will return to its normal trend. Since 2000 emissions have been rising by an average 3.4 per cent every year, compared to one per cent in the 1990s [The Telegraph]. Overall, worldwide emissions rose by 29 percent from 2000 to 2008, and the scientists put forward that 6 degrees Celsius global warming figure as a worst-case scenario—what could happen if the overall rising trend continued unabated.

The timing of their warning seems clear. This week President Obama and Chinese President Hu Jintao talked climate during their meeting in China, with the world climate summit looming. The two committed their countries — the biggest emitters of the heat-trapping gases causing global warming — to backing a detailed political agreement at next month’s climate-change conference in Copenhagen. In their formula, rich countries would commit to reduction targets while developing ones would agree to meet softer goals that would be monitored [MSNBC].

The most troubling assertion of the Global Carbon Project study, however, might be this: The team believes that carbon sinks – the oceans and plants – are probably absorbing a slightly lower proportion of the carbon dioxide from fossil fuel emissions than they were 50 years ago, although researchers admit that uncertainty about the behaviour of sinks remains high [BBC News].

Image: iStockphoto

Now For Sale at Fire Sale Prices: Thousands of People’s Genomes

Brett Israel — Wed, 18 Nov 2009 20:47:49 +0000

DeCode Genetics, a genome sequencing and drug development company, found out the hard way that predicting disease risk simply by reading someone’s genes isn’t so straightforward. On Tuesday, deCode filed for chapter 11 bankruptcy protection in Delaware. The company’s financial problems have also raised some troubling questions about genetic privacy.

DeCode’s mission was to uncover genetic risk factors for common diseases and to develop personal genome scans so individuals could learn their risk. DeCode quickly became the leader in the worldwide race to identify the causes of common disease. The company’s researchers discovered mutations linked to schizophrenia, heart disease, diabetes, prostate cancer and many other illnesses. Its approach was to identify the mutations first in Icelanders and then to confirm them in other populations [The New York Times]. Iceland was seen as an ideal spot for genetic studies, because the population was fairly isolated and the country has excellent medical and genealogical records. However, the company’s early successes did not translate into dollars, in part because the mutations they found only account for a small percentage of the overall incidence of a given disease.

DeCode published high profile scientific research on the human genome, but the company has struggled to survive for the past year as it took too long to convert discoveries into marketable products and opportunities for raising cash faded with the global credit crunch [Bloomberg]. Last year, the company began offering personal genetic tests in which customers sent in cell samples swabbed from the insides of their cheeks and got back reports on their genetic vulnerability to certain diseases. Many experts have argued that such tests have little value.

Despite their scientific advancements, deCode has been a failure as a business, burning through $700 million and failing to generate a single quarterly profit. When deCode filed for chapter 11 bankruptcy protection, they listed estimated total assets in the range of $50 million to $100 million and estimated total liabilities in the range of $100 million to $500 million [Reuters]. Saga Investments LLC placed the first bid on deCode for near $14 million.

Saga could continue the human genome research if they so choose. However, some privacy advocates are already worrying about what will happen to the genetic profiles from all of deCode’s customers. A deCode executive said that Saga would be bound by a privacy policy that prevents disclosure of data to third parties such as insurers, employers or doctors…. [But] pooled and anonymised information, for example, could be sold to academic researchers or pharmaceutical companies [The Times].

Image: iStockphoto

Nanosilver Puts the Hurt on Microbes—and Maybe Fish, Too

Andrew Moseman — Wed, 18 Nov 2009 17:56:46 +0000

Toys, refrigerators, washing machines, socks—more and more products contain silver nanoparticles. It’s no wonder: These particles, which measure less 100 nanometers (smaller than a single HIV virus), can kill microbes on contact. But, researcher Darin Furgeson says, nanosilver can also escape into ecosystems and cause serious damage to fish embryos. Furgeson’s team published its results in the journal Small.

In one new experiment, Furgeson, a professor of pharmaceutical sciences, exposed zebrafish embryos to silver nanoparticles in a laboratory, and found that some died and others were left with dramatic mutations. “Some of the fish became extremely distorted, almost making a number nine or a comma instead of a linear fish,” he said [Scientific American]. Eyes, tails, and other body parts turned out malformed in the fish that survived.

Just how much nanosilver gets into the environment? A separate study from Environmental Science & Technology washed nine kinds of nanosilver-containing textiles, including some “anti-bacterial and anti-odor socks” that are already on the market. The researchers found that anywhere from less than 1 percent to as high as 45 percent of the silver came out in the first wash. Most of the silver was in the form of coarse particles of greater than 450 nanometers, suggesting that mechanical stress in the washing machine was responsible for most of the release [The New York Times], and that the nanoparticles might have aggregated to reach that size.

Those nanoparticles flushed out by a washing machine can end up in both fish habitats and drinking water supplies. Furgeson says his fish experiments could help show whether nanosilver is a health concern for humans, too. “Zebrafish have similar tissues and organs to us,” Furgeson said. “They don’t have lungs, but they do have a liver, kidneys and heart – though it is only two chambered – and they have a blood-brain barrier” [Scientific American].

Image: Wiki Commons / Kristof vt

X-Rayed Mummies Reveal That Ancient Egyptians Had Heart Disease

Andrew Moseman — Wed, 18 Nov 2009 15:36:57 +0000

The elites of ancient Egypt had money, power, divine status in the case of the pharaohs, and also heart disease. In a study in today’s issue of The Journal of the American Medical Association, a team of researchers reports performing x-ray scans of 20 Egyptian mummies and finding them rife with cardiovascular disease like clogged arteries, one of the commonest ailments in modern American society.

On a visit to the Museum of Egyptian Antiquities in Cairo, one of the researchers had been intrigued by a nameplate on the remains of Pharaoh Merenptah, who died in 1,203BC. The plate said the pharaoh died at the age of 60 and suffered diseased arteries, arthritis and tooth decay [The Guardian]. So the scientists obtained permission to scan that mummy and others in the museum collection.

The common people of ancient Egypt weren’t mummified; only elites like royal families, their nursemaids, and priests got such a treatment. The elites ate salted fish, bread, and cheese like everyone else, but they also dined on rich foods such as cow, sheep, and goat meat, as well as honey and cakes with butter, says Abdel Nureldin, a professor of Egyptology at Cairo University, who worked on the investigation. At the same time, virtually no one in ancient times was sedentary, and that may have helped counteract their fatty diets [ScienceNOW Daily News].

Still, the researchers found, 16 of the 20 x-rayed mummies showed signs of heart disease. Men and women were affected equally. The most ancient of the mummies afflicted with atherosclerosis was Lady Rai, who had been a nursemaid to Queen Ahmose Nefertiti. She died at the age of 30 or 40 around 1530 BC, about 300 years prior to the time of Moses and 200 years before King Tut [Los Angeles Times].

Because only elite Egyptians were preserved so well after death, researchers can’t say how widespread cardiovascular disease might have been in the ancient society, or the ancient world at large. But what the finding does tell them is that while heart disease is exacerbated by the overindulgent and sedentary style of modern life, there’s more to it than that.

Image: Michael I. Miyamoto

Can a Genetic Variation Boost Empathy and Reduce Stress?

Brett Israel — Wed, 18 Nov 2009 11:06:07 +0000

One single difference in the human genome may play a role in behaviors such as empathizing and responding to stress. The research, published in the journal Proceedings of the National Academy of Sciences, focused on a single gene, called OXTR, which carries the design and production blueprint for cells scattered throughout the heart, uterus, spinal cord and brain that serve as docking stations for a chemical called oxytocin [Los Angeles Times]. Oxytocin is a chemical produced in the brain that makes us feel all warm and fuzzy when we interact with others in a nurturing or bonding way; it has also been shown to help mice stay calm when under stress.

The researchers decided to investigate a region on the OXTR gene associated with decreased social interaction in humans to see if small changes correlated to a person’s sociability and ability to handle stress. They put 192 college students through experiments to measure empathy and stress. One in four of the subjects had a particular variation of that gene region, and those subjects were significantly better at accurately reading the emotions of others by observing their faces than were the remaining three-quarters of subjects [Los Angeles Times]. The people in this subset were also less likely to startle during the stress test, and reported that they were generally chill folks.

Study coauthor Sarina Rodrigues provides the usual caveat that genes alone don’t determine our behavior and cautioned against reading too much into their discovery. Lots of people without the gene variation are able to understand and care about other people’s emotions, Rodrigues said [Telegraph]. So what are we supposed to do with this information? That’s not entirely clear, and the results need to be repeated in a larger group. Still, the work is “one solid step forward” in understanding the role of oxytocin in human social behavior, says neuroeconomist Paul Zak, … who has studied the effects of oxytocin on economic decisions [ScienceNOW Daily News].

One thing we do know is that, starting this weekend, if your employer somehow finds out that you are prone to high stress, at least they can’t fire you for it.

Image: flickr / le venti le cri