Archive for February, 2010

Tattoo-Removing Lasers Also Remove Grime From Classic Works of Art

By Andrew Moseman | February 26, 2010 3:13 pm

laser-cleaned-artIt sounded like a good idea at the time: You’d had one too many at the pub, one thing led to another, and you ended with someone’s name tattooed on your back. When you rushed out as soon as possible for laser removal of the unfortunate ink, the practitioners were actually using the same techniques that some art restorers employ to remove dirt and grime from masterpieces. And according to a new study in the journal of the American Chemical Society, Accounts of Chemical Research, laser ablation is getting better and more widespread in the art world.

Salvatore Siano at the Applied Physics Institute-CNR in Florence, Italy, tried out the method on a few classic works of art to record the results scientifically. He cleaned parts of a wall painting from a church in Siena, Italy, and also worked on Lorenzo Ghiberti’s gilded bronze panels Porta del Paradiso, or Gate of Paradise, and Donatello’s Renaissance bronze statue of David [BBC News]. While others have experimented like this over the last decade, he says, the Gates of Paradise was the first widely recognized masterwork to receive the treatment. He also notes that treating paintings poses the greatest challenge, but says that the laser cleaning showed great results–in the image above, the angel on the right was cleaned with laser ablation, while the two angels on the left received traditional cleaning.

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CATEGORIZED UNDER: Technology
MORE ABOUT: art, lasers

Spacecraft-Collected Comet Dust Reveals Surprises From the Solar System's Boondocks

By Andrew Moseman | February 26, 2010 1:21 pm

stardustcometSince NASA’s Stardust mission returned in 2006 from its trip of billions of miles collecting the dust of a comet called Wild2 and dropped it samples down to Earth in the Utah desert, the samples have raised all sorts of questions about how comets formed and what the early solar system was like. In a study this week in Science, there’s a new surprise. Scientists say that the comet sample contains chemicals that must have formed in our home turf, the inner solar system.

Lead researcher Jennifer Matzel studies a tiny particle taken from Stardust’s sample, a piece just five micrometers across. In it her team found the mark of materials that would have formed under high temperatures. Matzel, who specializes in using the decay rates of radioactive chemical elements to assess ancient dates, determined that the Stardust particle must have crystallized just 1.7 million years after the oldest solid rocks in the solar system were forming [San Francisco Chronicle]. After that, the researchers says, the particle must have been flung out to the Kuiper Belt, the region of icy comets revolving around the sun at a distance far past Neptune.

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CATEGORIZED UNDER: Space

An Iceberg the Size of Luxembourg Breaks Free From Antarctica

By Smriti Rao | February 26, 2010 12:58 pm

iceA giant iceberg has broken free from Antarctica, and scientists say the massive ice chunk could interfere with ocean circulation and wildlife–particularly Antarctica’s iconic residents, the emperor penguins.

The piece of ice broke free when another huge iceberg struck Antarctica’s Mertz glacier; now the two icebergs, with a combined weight of 700 million tons, are floating along the Antarctic coast. The iceberg collision and break-off is a rare event and occurs naturally every 50 to 100 years, scientists say. The new iceberg, which is 49 miles long and about 24 miles wide, holds enough fresh water to supply all of the earth’s human needs for a year [ABC News].

Scientists are keeping a close eye on the situation, as both icebergs could potentially change the salinity of the water in the area, which could alter the flow of ocean currents.

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CATEGORIZED UNDER: Environment
MORE ABOUT: Antarctica, iceberg

Sharp-Eyed Fish Can Tell Friend From Foe via Facial UV Markings

By Andrew Moseman | February 26, 2010 10:46 am

DamselfishWe know that there’s a whole spectrum of different wavelengths of light beyond the puny band of visible light we humans can see. And we knew that some animals, like certain species of fish and birds, have vision that extended beyond ours into wavelengths like ultraviolet. But a new study in Current Biology demonstrates that not only can damselfish see in UV, but that they can discern specific patterns in UV light, which is much more than we ever gave them credit for.

The findings are the first to show an animal “that is able to discriminate between fine-scale UV patterns using only their short-wavelength receptors (UV cones),” the researchers wrote in their study. These fish seem to use the UV cues to distinguish their own from other similar-looking species [Scientific American]. Prior to this, many researchers thought the fish’s UV vision just allowed them to detect the presence of UV light, and wasn’t refined enough to detect any kind of patterns.

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CATEGORIZED UNDER: Living World
MORE ABOUT: fish, ocean, UV light, vision

Killer Killer Whale "Tilikum" May Have Been Over-Stressed; Won't Be Euthanized

By Andrew Moseman | February 25, 2010 5:49 pm

orcaThere was no “Shamu Show” at SeaWorld today as people at the park mourned the death of Dawn Brancheau, the 40-year-old trainer apparently pulled to her death by Tilikum, one of the multiple killer whales the park uses under the name Shamu. As details continue to surface, park owners must decide what to do with the 12,000-pound aquatic animal.

First off, the public should keep in mind that this incident is highly unusual, says Wayne Perryman of the National Oceanic and Atmospheric Administration. He studies orcas (another name for killer whales) in the wild and says that they’ve never been known to attack a person as Tilikum has done, pulling Brancheau under water until she drowned. Perryman points out that other captive animals are known to snap and turn on their trainers—not just killer whales. “I think this isn’t really a killer whale issue,” he said. “It’s when you’re dealing with large mammals in a captive situation’” [National Geographic].

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CATEGORIZED UNDER: Living World

Underwater Robot Scientist Can Plan Experiments, Analyze Samples

By Smriti Rao | February 25, 2010 5:25 pm

_47367584_auv-under1It’s a robot that could change the way scientists gather data from underwater sources. Researchers from the Monterey Bay Aquarium Research Institute (MBARI) in California have developed a new autonomous underwater vehicle (AUV), and like other AUVs this sophisticated robot can slip under the waves, sweep the ocean floor, collect data, and perform programmed tasks. But the “Gulper” goes one step further–it doesn’t just follow its program, it can also make decisions on its own, and can plan its own route, avoiding hazardous currents and obstacles [BBC].

Explaining how the robot functions, Kim Fulton-Bennett from MBARI said: “We tell it, ‘here’s the range of tasks that we want you to perform’, and it goes off and assesses what is happening in the ocean, making decisions about how much of the range it will cover to get back the data we want” [BBC]. The ocean-going bot has also been described as “a microbiology laboratory in a can,” because it can analyze some samples in situ. The ‘ecogenomic sensor’, which is packed into a roughly 1-metre-long canister, can test for proteins released by microorganisms and even run DNA tests match DNA to determine which species are present [Nature News]. Findings can instantly be relayed to the shore, saving scientists the cumbersome task of transferring samples from site to lab.

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CATEGORIZED UNDER: Environment, Technology
MORE ABOUT: AUV, Mars rovers, ocean, robots

Investigation Says Texas Gave Newborns' DNA to Military Database

By Andrew Moseman | February 25, 2010 2:53 pm

Cute Baby Boy Isolated on WhiteFrom 2002 until a lawsuit last year, the state of Texas took the small blood samples taken from newborns to screen for diseases, and saved them without the parents’ consent. Texas always said it did this for research purposes, of which there are many. But there was a wee detail about all this that didn’t come to light until an investigation published this week in the Texas Tribune. According to the Tribune, between 2003 and 2007, Texas quietly handed over 800 of those samples to the military for a project to create a database of mitochondrial DNA, which people inherit from their mother.

Like virtually every state, Texas routinely screens almost all newborns for rare diseases, collecting a few drops of blood at birth. In recent years many states, Texas included, have stored the samples and offered them up for research, mainly in pediatrics [ScienceInsider]. Because the samples are anonymous, researchers decided it was okay to use them without parental consent. However, the Tribune’s investigation uncovered emails showing Texas state officials publicized the use of DNA taken from newborns in studies on childhood disease, but deliberately dissuaded state employees from divulging the use of baby blood in establishing a DNA database [Popular Science].

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CATEGORIZED UNDER: Health & Medicine, Technology

Study: Bacteria Can Make Avatar-Like Electrical Connections in Mud

By Andrew Moseman | February 25, 2010 1:14 pm

ElectricMudOnce again, laziness pays off. When microbiologist Lars Peter Nielsen and his team were studying marine sediments, they got a little sloppy about cleaning their beakers. But after letting samples sit around in the lab for a few weeks, they began to see weird chemical patterns in them that you just wouldn’t expect. As they saw changes in the surface of the mud quickly trigger other changes down below, the scientists came upon a startling idea: that the bacteria in the top layer and those deep down were somehow electrically linked. Their paper appears this week in Nature.

Specifically, Nielsen saw that hydrogen sulfide buried below the sediment’s surface (the stuff that makes it smell bad) was oxidizing and changing color. One problem, though: That shouldn’t be happening. Below the sediment surface there is plenty of hydrogen sulfide and carbon for bacteria to consume via oxidation, or removing electrons [Scientific American]. But the reaction can’t be sustained without access to dissolved oxygen, which carries away electrons produced by the reaction, and in these samples the oxygen was all up at the sediment’s surface. So the researchers hypothesize that the buried bacteria form a conductive chain to ferry the electrons up to the surface.

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CATEGORIZED UNDER: Environment, Living World
MORE ABOUT: bacteria, chemistry, ocean

Bear Fight! Grizzlies Are Creeping Into Polar Bears' Canadian Turf

By Andrew Moseman | February 25, 2010 10:37 am

GrizzlyUp north in the Canadian province of Manitoba, polar bears are receiving some unwelcome guests. Researchers have seen grizzly bears moving into the area for the first time, and that might not be good news for the already-troubled polar bears.

Linda Gormezano and her team, who are publishing the study (pdf) in Canadian Field-Naturalist, weren’t even looking for grizzlies when they started to spot the huge mammals; they were flying around counting fox dens. Before 1996, there was no evidence that grizzly bears encroached on polar bear territory. From that year on, however, there have been at least 12 sightings, negating the prior theory that the barren landscape north of the Hudson Bay was impassable, in terms of resources, for migrating grizzly bears [Discovery News]. If grizzlies can survive there, Gormezano says, they’ll probably want to stay, because there’s a bevy of caribou, fish, and other good things to eat.

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CATEGORIZED UNDER: Environment, Living World

A Gentleman Frog That Takes Monogamy & Parenting Seriously

By Smriti Rao | February 24, 2010 6:13 pm

frogMonogamy isn’t popular in the amphibian world. From frogs to salamanders, life in cold blood is all about meeting new ladies and hitting the road once the kids are born. So the male of a species of Peruvian poison frog (Ranitomeya imitator) stands out by proving that he is quite the keeper. He’s not only the first monogamous frog ever found, he also stays home and makes sure the tadpoles are fed.

Scientists studying these frogs say this unusual behavior–monogamy and co-operative parenting–could be directly attributed to the limited resources available to the frogs. They note that a broad study of 404 frog species show that species that deal with reduced food availability and greater difficulty in tadpole-rearing are more likely to have frog couples that work together to raise the young.

These findings could possibly shed some light on the way our hunter-gatherer ancestors approached monogamy. Details of the findings are to be published in the April issue of The American Naturalist.

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CATEGORIZED UNDER: Environment, Living World
MORE ABOUT: amphibians, frogs, monogamy
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