Wednesday, 9 February 2011

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge

Jupiter’s Moon Helps Peek Below Planet’s Belt

Posted: 09 Feb 2011 11:53 AM PST

Astronomers have a new view of the chaos brewing beneath Jupiter's cloud belt, thanks to some help from its icy moon Europa.

This new image, captured Nov. 30, 2010 with the 10-meter Keck II telescope in Hawaii, shows heat escaping from Jupiter's interior, giving astronomers a peek into the roiling turmoil inside Jupiter's missing red stripe.

The image shows Jupiter at four wavelengths of infrared light, which is beyond the range that human eyes can see. Three of those wavelengths show reflected sunlight. But one wavelength, 5 micrometers, can sense breaks in the cloud cover.

Jupiter's famous red stripe mysteriously faded in late 2009 and vanished altogether by May, 2010. Observations with Hubble and other telescopes showed that the ruddy band was hiding beneath a layer of high, bright clouds made from icy ammonia crystals.

Last November, bits of the red band started coming back.


Astronomers wanted to use Keck's thermal-sensing eyes to peel back the cloud layers. To get sharp pictures of the sky, Keck shines a laser on the sky to create a fake star and uses it to cancel out the blurring effects of the Earth's atmosphere.

But Jupiter is so bright, it outshines the laser star. Astronomers needed another tiny light source right next to Jupiter to guide the telescope's atmosphere-canceling system.

Jupiter's icy moon Europa turned up at just the right moment.

"Because Jupiter is close to Europa in the sky, it will be experiencing similar distortions," said astronomer Mike Wong of the University of California at Berkeley, who helped make the observations. "So if we can measure Europa's distortions, those same distortions can be corrected for Jupiter."

The resulting images show that the return of Jupiter's cloud belt is happening at different speeds in each layer of the gas giant's atmosphere.

"This shows us some of the 3D structure of what's going on," Wong told "Without the 5 micron observations, we wouldn't know that the changes we're seeing are isolated to individual cloud layers."

Images: Mike Wong, Franck Marchis & W.M. Keck Observatory

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Astronomers Suggest Crowdsourcing Letters to Aliens

Posted: 09 Feb 2011 08:00 AM PST

Before trying to contact aliens, maybe we should test the messages on ourselves.

In a new paper in the journal Space Policy, three alien hunters suggest designing a standard protocol for writing intelligible letters to extraterrestrials, and building a website where teams can decode candidate messages to ensure they make sense.

"The basic idea is, if you're going to talk to aliens, you'd better have something that's understandable to humans," said Caltech planetary scientist Michael Busch, who has tried to design an ideal alien postcard but was not involved in the new work.

The search for extraterrestrial intelligence, colloquially known as SETI, has been attempting to eavesdrop on intelligent civilizations for the last 50 years, mostly by piggybacking on existing astronomical sky surveys. But as a species, humanity has tried to call ET only a handful of times.

These earlier messages were too complicated and human-centric to make sense to even a technologically advanced alien civilization, the researchers argue.

"If I make a presentation on the Keynote software on Mac, you won't be able to open it on a Windows machine here on Earth," said physicist Dimitra Atri of the University of Kansas, a coauthor of the new paper. "Forget about sending it to a distant planet."


The first dispatch, the Arecibo message (right), was fired in 1974 at a globular cluster 25,000 light-years away. It included a pixelated graphic of a human, the numbers one through ten, and a graphic of the radio telescope used to transmit the message — though you almost can't tell to look at it.

"It was largely just for decoration, essentially," said astrobiologist Julia DeMarines of the International Space University in France, a coauthor of the paper. "It was cool, but it wasn't really a directed message."

The next four messages — the Cosmic Calls of 1999 and 2003, the Teen Age Message of 2001 and "A Message From Earth" in 2008 — were sent from a radio telescope in Evpatoria, Ukraine.

Those broadcasts went to more local stars, between 20 and 69 light-years from Earth, where we could hope to hear back from anyone listening in. But they included recordings of classical music and photographs and drawings submitted by the public — information of sentimental value to Earthlings, but gibberish to aliens who might not even have eyes or ears.

To help increase the odds that ET will hear us when we call, Atri, DeMarines and astrobiologist Jacob Haqq-Misra of The Pennsylvania State University suggest designing a standard protocol for writing SETI messages.

"The paper is really a call for unity among thinking about messaging exraterrestrials," Haqq-Misra said. "Right now it's messy, it's kind of all over the place. Maybe we can increase our success chances by being more unified about this."

The protocol would cover issues like message length (keep it short at first), signal encoding (binary is probably best), transmission method (radio, or some other frequency?) and information content (math and science, or human culture?). The main idea is to keep it simple, the researchers say.

"We want to make sure we're not being too anthropocentric, making sure the answer can be accessible to the lowest common denominator," Haqq-Misra said. "Until we meet one, we won't know" how to talk to them.

This paper is just a first step. The alien-hunters are trying to round up a committee of scientists, communicators, philosophers and others who think about SETI to help design the protocol.

"It's like fantasy football, but for SETI," DeMarines said.

Once the rules are in place, the team will build a website where users worldwide can submit messages that fit the protocol, and try to crack each others' codes. The team hopes to have the website up and running by this summer.

Such a game would not only refine the software used to encode the messages. It could also help reveal which concepts are specific to certain cultures, and which are human universals.

"You might be surprised at what things do and don't translate," Haqq-Misra said. "It might give people perspective about what is universally understood, if anything."

"It's certainly very useful, and potentially important," Busch said. "But whether we'll use this to actually talk to somebody out there, we have to find somebody to talk to first. Its true potential may not be known for a whole lot longer than I plan to be alive."

Image: 1) H. Schweiker/WIYN and NOAO/AURA/NSF. 2) Wikimedia Commons/Arne Nordmann

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Video: Vacuum Tubes Implode in the Name of Physics

Posted: 09 Feb 2011 06:34 AM PST

To design stronger vacuum tubes for a proposed high-stakes physics experiment, researchers first need to understand their weaknesses — so they blew up the devices in an old torpedo test chamber.

The destructive tests, seen in the video above, support the development of a planned $1 billion experiment to detect neutrinos, particles that are forged in the heart of stars. Despite being as numerous as photons of light in the universe, they are virtually undetectable — it takes a lifetime of trillions passing through your body each second for just one to interact with a cell.

The ghostly particles are thought to play crucial roles in everything from triggering supernovas to the evolution of the cosmos.

"Neutrinos could be responsible for why the universe is made out of matter and not antimatter. Basically, for why we exist," said particle physicist Milind Diwan of Brookhaven National Laboratory. "We are planning to build a gigantic underground detector to understand a key property that may have caused an imbalance in favor of matter."

That property is how neutrinos morph into one of three "flavors" over long distances, and the detector proposed to study it is called the Long Baseline Neutrino Experiment.


The project involves two major facilities. Fermilab near Chicago would shoot the world's most intense neutrino beam toward an abandoned South Dakota mine about 800 miles away. There, two 37-million-gallon water tanks lined with up to 50,000 basketball-sized photomultiplier tubes would catch light emitted when neutrinos hit water.

Data collected should reveal how neutrinos morph over long distances — but one overlooked manufacturing defect, improper installation or accident could implode a photomultiplier under pressure and set off a chain reaction of destruction. A single faulty tube in a Japanese neutrino detector, for example, destroyed close to 7,000 of its 11,000 photomultipliers in 2001.

"Each LBNE tank's photomultiplier array may cost roughly $100 million, so you have to make sure one flaw won't take down everything with it," Diwan said.

To understand the dynamics of photomultiplier tube destruction in an environment similar to the proposed tanks, Diwan and five colleagues at Brookhaven found a mothballed Navy torpedo testing chamber in Rhode Island. The researchers filled up the 50-foot-wide, 500,000-gallon sphere and imploded the tubes while filming the action with high-speed cameras.

The team is currently building a computer model with data from the tests, but they ultimately hope to expose a full array of tubes to punishing shockwaves at the Navy facility.

"We know the shockwave's intensity and how it spreads, but we don't know if it will take out other tubes," Diwan told "We still have a ways to go."

The LBNE project is only in planning stages and not fully approved by the Department of Energy. But Diwan hopes construction of the colossal device will begin sometime in 2015 and be online by 2022.

Video: Three different underwater implosion tests courtesy of Brookhaven National Laboratory. 1) A 3,800-frames-per-second sequence of a lightbulb imploding in a 60-gallon pressurized water tank. 2) A photomultiplier tube imploding in the same 60-gallon tank at 6,000 fps (a nail-like device at the bottom right triggers the tube's collapse). 3) A tube implodes within the Navy's 17-year-old torpedo test bed called the Propulsion Noise Test System at 6,000 fps.

Image: Photomultiplier vacuum tube./Brookhaven National Laboratory.

Via Brookhaven bits & bytes.

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Prehistoric Pregnancy Booster Now Fuels Diabetes

Posted: 08 Feb 2011 01:33 PM PST

A genetic variation that may increase a woman's risk of gestational diabetes is widespread today because it was actually beneficial to early agricultural populations, a new study suggests.

Pregnant women who carry two copies of a low-activity form of the gene GIP have higher blood-glucose levels — a marker of gestational diabetes risk — Sheau Yu Teddy Hsu of Stanford University and colleagues reported online Feb. 7 in Diabetes. But when the gene's low-activity version arose somewhere in Eurasia an estimated 8,100 years ago, that same glucose-boosting quality may have helped women maintain their pregnancies during lean times.

The new work takes an important step toward characterizing how one particular form of a gene shapes physiology and how evolution may act on that gene, says Joshua Akey, an evolutionary biologist and population geneticist at the University of Washington in Seattle.

Hsu and his colleagues recently reported evidence that the low-activity version of the GIP gene first appeared about 8,100 years ago and rapidly became part of the genetic makeup of Eurasians. Today about half of Europeans carry the new form of GIP, while 70 percent or more of Asians do. Only about 5 to 10 percent of Africans have the new form of the gene.

"It arose very fast, so it must have some dramatic effect on human viability," Hsu says.


GIP helps stimulate insulin production after a meal. Insulin, in turn, helps cells more efficiently use sugars from food. Too little insulin can lead to high levels of sugar in the blood, a symptom of diabetes. But higher blood sugar levels may also help fetuses grow. The new form of the gene may have given people an evolutionary advantage to survive famines, the researchers speculate.

At about the same time that the new form of GIP appeared, people in Europe and Asia were switching from a hunter-gatherer lifestyle to one based on agriculture. That switch may have exposed people to more frequent periods of famine, such as between harvests or when crops failed. The new version may have kept mothers' blood-sugar levels high enough to provide developing fetuses with energy to survive short periods of famine.

In the new study, the researchers tested whether the new form of the gene had any effect during pregnancy. Study co-author Chia Lin Chang of Chang Gung University in Taiwan collected routine blood samples from 123 pregnant women. The team analyzed blood sugar concentrations and found that women with the new form of the gene had higher levels than women with the ancestral form.

Now the researchers want to test women from other populations to see if the gene acts the same way in everyone, and if it might help predict who is likely to develop gestational diabetes.

Image: Flickr/seancmcgrath.

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Study: Math Skills Rely on Language, Not Just Logic

Posted: 08 Feb 2011 09:00 AM PST

Knowing a language that uses counting words can shape one's ability to understand large numbers.

A new study of deaf people who have made up their own hand signals to communicate shows that without number words, it's hard to keep track of more than three objects at a time.

"Learning language really shapes the way we think," said cognitive psychologist Elizabet Spaepen of the University of Chicago, lead author of a paper published Feb. 7 in the Proceedings of the National Academy of Sciences. "It can change the way we conceptualize something as seemingly basic as number."

Psychologists had already suspected that language was important for understanding numbers. Earlier studies of two tribes in the Amazon — one that had no words for numbers greater than five and another whose counting system seemed to go "one, two, many" — showed that people in those tribes had trouble reporting exactly how many objects were placed in front of them.

But in those cultures, which don't have monetary systems, there might be no need to represent large numbers exactly. The question posed was whether language kept those Amazonian people from counting, or a lack of cultural pressure.

To address that question, Spaepen and colleagues turned to Nicaraguan homesigners, deaf people who communicate with their hearing friends and relatives entirely through made-up hand gestures.

"They're the perfect test case for culture versus language," Spaepen said. "They're totally integrated into the economy of Nicaragua, they have jobs, they make money. But they don't learn a conventional language. They have to create one."


Homesigners in Nicaragua are famous among linguists for spontaneously creating a fully formed language when they were first brought together at a school for the deaf in the 1970s. But many homesigners stay at home, where they share a language with no one. Their "home signs" are completely made up, and lack consistent grammar and specific number words.

Over the course of three month-long trips to Nicaragua in 2006, 2007 and 2009, Spaepen gave four adult Nicaraguan homesigners a series of tests to see how they handled large numbers. They later gave the same tasks to control groups of hearing Nicaraguans who had never been to school and deaf users of American Sign Language (which does use grammar and number words) to make sure the results were not just due to illiteracy or deafness.

First, the researchers showed the homesigners ten short animated stories where numbers were central to the plot. For example, one story opened with 8 frogs on lily pads. Four jumped away all at once, and two came back one at a time.

When asked to recount the vignettes to a friend who knew their hand signals, the homesigners used their fingers to indicate the number of frogs. But when the numbers got higher than three or four, the signers' accuracy suffered.

Spaepen then showed the signers flashcards with different numbers of items like fish or beach balls on them, and asked them to report how many items were on each card. Homesigners, ASL-signers and Spanish-speakers alike were spot-on for cards with one, two or three fish, no matter how long they spent looking at the card. When they had only a few seconds with the card, all three groups guessed the exact number about a third of the time.

Given unlimited time with the cards, though, the groups whose languages had counting words gave the right number of fish almost every time. The homesigners could only give the exact number 44 percent of the time.

"The homesigners in the estimation task look like anyone else would," Spaepen said. "The thing is, they also look like estimators when they're given all the time in the world to count, or whatever you would do."

In another test, Spaepen showed the homesigners a row of one to 20 poker chips, and asked them to create an identical array. When all the chips were visible, the signers had no difficulty matching their chips one-to-one to Spaepen's. But when Spaepen's chips were covered up, the signers couldn't come up with the correct number of chips in their own array.

"The homesigners had no trouble understanding what we were asking them to do," Spaepen said. "They just couldn't do it."

Oddly, the homesigners did use their fingers to keep track of objects, the way children use their fingers to count. Spaepen thinks the signers use each individual finger to represent a unique object — the index finger is the red fish, the middle finger is the blue fish — and not the abstract concept of the number of fish.

"They can't represent something like exactly seven," Spaepen said. "What they have is a representation of one-one-one-one-one-one-one."

This might be similar to the way children learn numbers in the first place, she said. Research on child development shows that kids start by memorizing numbers as an ordered list. They can recite the numbers from one through ten, but if you ask them to give you three apples, they're just as likely to give you five or seven.

The age at which kids start connecting their ordered list to numbers of things depends a lot on how much reinforcement they have from adults. Some children learn to count by age two; others, usually from disadvantaged households, arrive at school not knowing what "two" means. The homesigners represent those disadvantaged kids taken to the extreme.

"Language input is important for everybody's representation of number, and how counting works," Spaepen said. "This isn't something you just get for free because you're human. It depends on the quality and amount of input you get. If you're not getting it in your language, you're not going to just come up with it on your own."

"I think it's a really nice result," said psychologist Peter Gordon of Columbia University, who suggested in 2004 that the Pirahã people's "one-two-many" language kept them from understanding large numbers. The study was well-designed and took care to rule out other possible explanations, he added.

"It really nailed down the role of language as opposed to culture," he said.

Video: One of the Nicaraguan homesigners telling a story in which 10 sheep stand in a pen. He incorrectly holds up 9 fingers to describe the number of sheep. (Elizabet Spaepen, University of Chicago)

"Number without a language model." Elizabet Spaepen, Marie Coppola, Elizabeth S. Spelke, Susan E. Carey, Susan Goldin-Meadow. PNAS, Feb. 7, 2011. DOI: 10.1073/pnas.1015975108.

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Allergies Linked to Brain Tumor Protection

Posted: 08 Feb 2011 04:00 AM PST

Hay fever, dog, peanut and other allergies may protect sufferers from certain types of brain tumors, a new study suggests.

In surveys of hospital patients, individuals with glioma — a common form of brain and spinal cancer — were less likely than cancer-free individuals to report having allergies, University of Illinois at Chicago researchers report online Feb. 7 in Cancer Epidemiology, Biomarkers & Prevention.

Several teams had previously explored the link between allergies and glioma, says UIC epidemiologist Bridget McCarthy, who led the study. Her team set out to confirm these results, cobbling together a wide list of variables. The researchers quizzed about 1,000 hospital patients with or without cancer about their allergy histories. Of the 344 patients with high-grade glioma, about 35 percent reported having been diagnosed with one or more allergies in their lifetimes, compared with about 46 percent of the 612 cancer-free respondents. About 10 percent of high-grade tumor patients had three or more allergy diagnoses, as opposed to 22 percent of the controls. "The more allergies you have, the more protected you were," says McCarthy, an oncologist at UIC.

Glioma isn't the first cancer to be negatively correlated with common allergies, says Michael Scheurer, an oncologist at Baylor Medical College in Houston. Allergy-prone people may fight off colorectal and pancreatic cancer, and even childhood leukemia, better than sniffle-free people, according to some studies. At the other end of the spectrum, allergies that cause asthma may spur lung tumors.


Just why these links exist isn't clear. Allergy sufferers mount heightened immune responses to some foreign or dangerous cells and chemicals, says Scheurer, who was not involved in the study. And cancer cells are certainly dangerous — human immune systems naturally seek them out. The immune systems in people with allergies may just do it better. "They have an overactive immune system, and maybe that's been protecting them from the development of tumors," he says.

In December, Scheurer and his colleagues reported finding a link between risk for one type of glioma and use of the antihistamine drugs like diphenhydramine — the active ingredient in Benadryl. The Chicago team did not find such a link.

Scheurer says Benadryl users shouldn't worry. "Brain tumors are very, very rare tumors, and a lot of people take antihistamines." He suspects that in a small set of individuals with a genetic predisposition to brain cancer, antihistamines may slow down the immune response, giving cancer cells an opening.

These sorts of studies can easily produce varying results simply because there are so few participants, Scheurer adds. His colleague Melissa Bondy at the University of Texas M.D. Anderson Cancer Center in Houston has launched an effort to conduct similar surveys of 6,000 glioma patients and a comparison group without the disease. Both McCarthy and Scheurer hope that such efforts will give researchers a better look at what makes brain tumors grow.

Glioma and brain tumors in general are rare, Scheurer says, but devastating. Few patients with high-grade glioma survive longer than five years. So there's a big need to develop safe and effective treatments. "There's a strong community of researchers who are interested in brain tumors," he says "And we don't give up."

Image: Dandelion seeds. (Flickr/jfl1066).

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