from the Scientist (Registration Required)
The cells responsible for the salamander's famed ability to regenerate amputated limbs aren't pluripotent, as scientists have thought, a study published online in Nature reports.
That's good news for regenerative medicine: If the mechanism salamander cells use for regrowing body parts doesn't depend on pluripotent stem cells, it may be easier than researchers have assumed to mimic that organism's regenerative strategy in potential therapies.
"This is a very important finding for this field and also for regenerative medicine in general," said regeneration biologist Andras Simon of the Karolinska Institutet in Sweden, who was not involved in the research.
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from New Scientist
Shootings and killings in deprived areas of Chicago and Baltimore have plummeted by between 41 and 73 percent thanks to a programme that treats violence as if it is an infectious disease. Pioneers of the programme, called CeaseFire, say it relies on simultaneously changing attitudes and behaviour and will work anywhere.
The key is to change social norms so that violence is seen as "uncool" both by potential perpetrators and their communities, instead of being the automatic way to settle a dispute.
On 30 June, pioneers of the programme publicised their high success rate so far to attract interest at a time in the year when violence peaks, triggered by the heat.
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from the San Diego Union-Tribune (Registration Required)
BANGKOK, Thailand (Associated Press) — Fossils recently discovered in Myanmar could prove that the common ancestors of humans, monkeys and apes evolved from primates in Asia, rather than Africa, researchers contend in a study released Wednesday.
However, other scientists said that the finding, while significant, won't end the debate over the origin of anthropoids – the primate grouping that includes ancient species as well as modern humans.
The pieces of 38 million-year-old jawbones and teeth found near Bagan in central Myanmar in 2005 show typical characteristics of primates, said Dr. Chris Beard, a paleontologist at the Carnegie Museum of Natural History in Pittsburgh and a member of the team that found the fossils.
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from the Boston Globe (Registration Required)
LOS ANGELES (Reuters) - The interplanetary space probe Ulysses officially ceased operations on Tuesday after an 18-year voyage of roughly 5.5 billion miles and nearly three complete orbits around the sun, NASA said.
Radio contact with the Volkswagen-sized spacecraft was halted by ground controllers shortly after 4 p.m. EDT, but NASA project manager Ed Massey said Ulysses will continue its wide, elliptical orbit around Earth's local star indefinitely.
He said there was a chance the probe might eventually swing close enough to one of Jupiter's moons to alter its course and place it on a path that will take it out of solar system and into interstellar space.
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from the Washington Post (Registration Required)
The Environmental Protection Agency on Tuesday granted California's request to set its own limits on greenhouse gases from autos -- a long-sought victory with limited impact now that the federal government has pledged to impose national limits.
That decision grants California a waiver to impose a limit on the emissions from new cars, when no such rules now exist in federal law. ... The District and 13 states, including Maryland, have pledged to adopt California's new rules as their own.
Automakers selling in these states will be required to reduce new cars' average emissions by 5 percent in 2010, by 14 percent by 2011, and by 20 percent by 2012, said Tom Cackette, a deputy director of the California Air Resources Board. But a White House announcement in May drained this decision of much of its meaning.
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from BBC News Online
A single mega-colony of ants has colonised much of the world, scientists have discovered. Argentine ants living in vast numbers across Europe, the US and Japan belong to the same interrelated colony, and will refuse to fight one another.
The colony may be the largest of its type ever known for any insect species, and could rival humans in the scale of its world domination. What's more, people are unwittingly helping the mega-colony stick together.
Argentine ants (Linepithema humile) were once native to South America. But people have unintentionally introduced the ants to all continents except Antarctica. These introduced Argentine ants are renowned for forming large colonies, and for becoming a significant pest, attacking native animals and crops.
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from ScienceNOW Daily News
Piranhas have long been a staple of horror movies, and it's no wonder. Their razor-sharp teeth can tear chunks of flesh from creatures many times their size. Now scientists have rediscovered a fossil piranha jaw that shows how the fish got those choppers.
The closest living relatives of piranhas are pacus, South American river fish that eat mostly plants. ... But pacu teeth aren't nearly as pointy and terrifying as those of the piranha. Another key difference is that pacu teeth are arranged in two rows, whereas piranha teeth are lined up in a single row.
In the 1950s, a scientist proposed that the common ancestor of piranhas and pacus had two rows of teeth, which eventually merged into a single row in piranhas. But nobody had ever seen a fossil showing an intermediate arrangement.
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from the New York Times (Registration Required)
CASAS GRANDES, Mexico — From the sky, the Mound of the Cross at Paquimé, a 14th-century ruin in the Mexican state of Chihuahua, looks like a compass rose — the roundish emblem indicating the cardinal directions on a map.
... "It's a hell of a long way from here to Chaco," says Steve Lekson, an archaeologist from the University of Colorado, as he sights along the north-south spoke of the cross. Follow his gaze 400 miles north and you reach Chaco Canyon in northwestern New Mexico, a major cultural center occupied from about A.D. 900 to A.D. 1150 by the pueblo people known as Anasazi.
Despite the distance, Dr. Lekson believes the two sites were linked by an ancient pattern of migration and a common set of religious beliefs.
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from Seed
Organizing the world's species into branches on a phylogenetic tree is a major goal of biologists trying to understand how life evolved.
DNA-sequencing technologies are providing them with more information than ever with which to accomplish this goal, but with less than 1 percent of all species currently placed in any kind of phylogeny, there is still much work to be done.
In a recent paper in Science, researchers at the University of Texas at Austin introduced new tree-building software that could expand the tree of life and change our understanding of evolution.
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from National Geographic News
There's no evidence of goosebumps just yet, but a remarkably preserved dinosaur reveals that the prehistoric reptile had skin like that of birds and crocodiles, a new study says.
"This is the closest you're going to get to patting the animal," said excavation leader Phillip Manning, a paleontologist at Britain's University of Manchester.
Advanced imaging and chemical techniques revealed that the 66-million-year-old "mummified" duckbilled dinosaur had two layers of skin, as do modern vertebrates, including humans. Such a discovery was possible because the dinosaur's skin fossilized before bacteria had a chance to eat up the tissue.
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from the New York Times (Registration Required)
Could it be that humans are not quite as gullible as advertised? For a couple of decades now, social psychologists and behavioral economists have been amusing themselves manipulating consumers into doing odd things.
... Old-fashioned cost-conscious consumers would react to a price increase by lowering demand for the product, but we sometimes do just the opposite. We want to buy more of it because we assume it must be a better product — and we're so thoroughly fooled that our bodies even respond differently to it.
If you give people a placebo and tell them it's a painkiller costing $2.50, they can withstand painful shocks better than if they're told the pill costs a dime. Give them an energy drink at a discount price, and they'll perform worse on subsequent tests than if they pay full price.
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from Science News
Kicking up more dust in deserts may bring unnaturally synchronized spring greening to mountain peaks.
Livestock grazing, mining and other human activities in dry lands churn up extra dust that winter storms sweep away and dump on distant alpine slopes along with snow, explains Heidi Steltzer of Colorado State University in Fort Collins.
Darkening the snow speeds up the spring melt of the snowpack, but Steltzer and her colleagues now find that it won't speed up the first sprouts of spring. Premature bald spots instead stay wintry until certain signs of spring pass a threshold, the researchers report online June 29 in Proceedings of the National Academy of Sciences.
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from New Scientist
The vast majority of species on Earth are single-celled. Most of these languish in obscurity – many have never even been named – but some of the relatively few species that have been studied exhibit remarkable abilities.
Many of these are physical: some micro-organisms are amazingly strong; others can hibernate for hundreds of thousands of years or thrive in environments so extreme that they would kill off most other life forms in a flash.
But many bacteria and protists also exhibit behaviour that looks remarkably intelligent. This behaviour isn't the result of conscious thought – the sort you find in humans and other complex animals – because single-celled organisms don't have nervous systems, let alone brains.
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from National Geographic News
By scanning a 54-million-year-old skull roughly the size of a walnut, scientists have created the first virtual 3-D model of an early primate brain, a new study says.
Surprisingly, the model suggests that primates (such as lemurs, monkeys, apes, and humans, among others) might have evolved larger brains as a result of the need to move quickly from tree to tree—not, as commonly assumed, to hunt for fruit or navigate within a single tree.
The 1.5-inch-long skull belongs to the long-gone Ignacius graybullianus—described as a cousin of our earliest ancestors—which arose less than ten million years after the dinosaurs vanished.
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from the New York Times (Registration Required)
A blood protein that only a short time ago was thought by some to be more important than cholesterol in heart disease now appears to be little more than a bystander.
The substance, C-reactive protein, or CRP, a marker of inflammation in the body, is unquestionably associated with heart disease: the more CRP in a person's blood, the greater the likelihood of heart disease.
But in a paper to be published Wednesday in The Journal of the American Medical Association, researchers analyzing genetic data from more than 100,000 people conclude that their study "argues against" the notion that the protein causes heart disease.
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from BBC News Online
The most complete terrain map of the Earth's surface has been published. The data, comprising 1.3 million images, come from a collaboration between the US space agency NASA and the Japanese trade ministry.
The images were taken by Japan's Advanced Spaceborne Thermal Emission and Reflection Radiometer (Aster) aboard the Terra satellite. The resulting Global Digital Elevation Map covers 99% of the Earth's surface, and will be free to download and use.
The Terra satellite, dedicated to Earth monitoring missions, has shed light on issues ranging from algal blooms to volcano eruptions. For the Aster measurements, local elevation was mapped with each point just 30m apart.
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from the Wall Street Journal
Julia Strecher was 9 years old when she had her second heart transplant. Her body had rejected the first heart she received with particular vehemence: She went into cardiac arrest six times in two hours. As doctors struggled to revive her, she recalls, she could hear them debating whether to give up.
... A few months after she went home with her second new heart, she began having nightmares in which she watched herself suffering cardiac arrest. But then, she began writing down her thoughts about being helpless. Eventually she turned the details into poems and stories. "It was extremely emotionally healing and freeing," she said. "It helped me relieve a lot of stress and provided a distraction from pain and depression." The nightmares went away.
Ms. Strecher's case seems a striking illustration of the healing potential of creative expression. But is it science? Can the power of the arts to soothe, transform and inspire be enlisted to treat—and perhaps even prevent—heart disease?
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from the Washington Post (Registration Required)
Meteorologist Patrick Marsh huddles over a computer screen at NOAA's Storm Prediction Center in Norman, Oklahoma, anxiously tracking the progress of the armada of researchers taking part in the largest tornado research project in history, known as "VORTEX2."
It is June 10, only three days before the end of the first field campaign in the $10 million research program to investigate how tornadoes form. ... [Marsh] and his colleagues provide situational awareness support for the approximately 100 researchers who are hunting powerful thunderstorms known as "supercells" in the Great Plains region.
The scientific armada is represented on Marsh's screen by multi-colored dots, each of which is slowly ticking west across Kansas to meet up with incipient storms in far southeastern Colorado.
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from the Los Angeles Times (Registration Required)
For most of the last 15 years, the Food and Drug Administration's authority to regulate tobacco has been either a thwarted promise or a fitful threat, depending on your point of view.
It has been pressed by anti-smoking crusaders and public health groups, put on hold by the Supreme Court and beaten back repeatedly by the tobacco industry and its political allies.
... But on June 22 ... President Obama (himself a smoker who's struggled to quit) signed into law a measure giving the FDA all the authority over tobacco that it has periodically sought, and more. That's a measure not only of the doggedness of some lawmakers, but how the American landscape has changed for the makers of tobacco products.
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from USA Today
ADELPHI, Md. (Associated Press) — Government experts say prescription drugs like Vicodin and Percocet that combine a popular painkiller with stronger narcotics should be eliminated because of their role in deadly overdoses.
A Food and Drug Administration panel on Tuesday voted 20-17 that prescription drugs that combine acetaminophen with other painkilling ingredients should be pulled off the market.
The FDA has assembled a group of experts to vote on ways to reduce liver damage associated with acetaminophen, one of the most widely used drugs in the U.S. Despite years of educational campaigns and other federal actions, acetaminophen remains the leading cause of liver failure in the U.S., according to the FDA.
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from the New York Times (Registration Required)
LINCOLN, Mass. — Sara Lewis is fluent in firefly. On this night she walks through a farm field in eastern Massachusetts, watching the first fireflies of the evening rise into the air and begin to blink on and off. Dr. Lewis, an evolutionary ecologist at Tufts University, points out six species in this meadow, each with its own pattern of flashes.
... The fireflies flashing in the air are all males. Down in the grass, Dr. Lewis points out, females are sitting and observing. They look for flash patterns of males of their own species, and sometimes they respond with a single flash of their own ...
... For the past 16 years, Dr. Lewis has been coming to this field to decipher the evolutionary forces at play in this production, as fireflies have struggled to survive and spread their genes to the next generation.
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from Seed
... Though life's story stretches back billions of years, only its somewhat recent chapters are at all clear, and even then mostly in the ocean, where fossils are more easily formed and preserved.
Starting with the advent of abundant marine fossils about 500 million years ago, biodiversity's development over time can be seen as a rising curve; more kinds (genera) of creatures exist now than existed 500 million years ago. But closer scrutiny reveals wiggles along this steady, gradual rise.
Though they may appear minor, some of these short-term fluctuations were the most dramatic events in life's history, precipitous drops in biodiversity known as mass extinctions. ... One of the big mysteries associated with these phenomena is also a key question for life's future: Do they occur with any regularity?
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from The Scientist (Registration Required)
The windswept peak of Socompa Volcano, on the border of Argentina and Chile, is not a nice place to visit.
Parching winds scour the mountain's gravelly slopes, temperatures can swing from below freezing at night to more than 38 degrees Celsius during the day, and the scarcity of oxygen atop the more than 6,000-meter peak fends off all but the hardiest of mountaineers. You certainly wouldn't want to live there.
That is, unless you happened to be a microbial community inhabiting the thin crust of soil covering loosely-packed gravel, and imbibing your nutriment from gases seeping up from the heart of the dormant lava cone.
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from Scientific American
... Katey Walter finds herself center stage in an environmental drama playing out across the frozen north. ... Walter was the first to explain the mysterious methane emissions from Arctic lakes.
She isn't shy about touting their significance as a ticking time bomb. In a complete Arctic thaw, these lakes could discharge a whopping 50 billion tons of methane: 10 times the amount already helping to heat the planet.
Whether a total or more moderate release is in store is still anyone's guess. But pound for pound, methane in the atmosphere traps 25 times more of the sun's heat than CO2 does. Consequently, even a modest thaw of the perennially frozen soil that lies under these ephemeral lakes and caps the dry land around them could trigger a vicious cycle ...
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from Nature News
The computers of tomorrow could be quantum not classical, using the quantum world's strange properties to vastly increase memory and speed up information processing. But making quantum computing parts from standard kit has proved difficult so far.
Now physicist Leonardo DiCarlo of Yale University, New Haven, and his colleagues have made the first solid-state quantum processor, using similar techniques to the silicon chip industry. The processor has used programs called quantum algorithms to solve two different problems. The work is published in Nature.
Classical systems use a series of 0s and 1s, or bits, to convey information. Two bits, for example can be combined as either 00, 11, 01 or 10. But quantum systems have a property called superposition, where all these combinations can exist at once. This vastly increases the amount of information that can be stored and the speed at which it can be processed.
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from the Los Angeles Times (Registration Required)
More than 1,000 years before humans began domesticating grains for food, they were building sophisticated storage buildings to hold the wild grains they were cultivating, researchers reported Monday.
Collecting large quantities of grains and other foods is a prerequisite to establishing sizable communities, but such collection requires a system to store the perishables so they can be kept for months at least.
The new find reported in the Proceedings of the National Academy of Sciences represents the oldest known storage system or granary to date -- about 11,300 years old. The earliest known domestication of cereal grains was thought to have occurred about 10,500 years ago.
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from Science News
Residents of Louisiana, take note: If engineers don't divert sediment-rich waters from the Mississippi River to help replenish a sinking river delta, about 10 percent of your state will slip beneath the waves by the end of this century.
However, even if the engineers do try to abate the subsidence, the Mississippi doesn't carry enough sediment to offset more than a small fraction of that loss, a new analysis suggests.
Over the past few centuries, about a quarter of the wetlands in the Mississippi River delta have been lost to the ocean, says Harry Roberts, a marine geologist at Louisiana State University in Baton Rouge. Several factors have contributed to that loss, he notes, including sea-level rise and the settling of land as ancient sediments gradually become compacted under their own weight.
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from the New York Times (Registration Required)
A new method of attacking cancer cells, developed by researchers in Australia, has proved surprisingly effective in animal tests. The method is intended to sidestep two major drawbacks of standard chemotherapy: the treatment's lack of specificity and the fact that cancer cells often develop resistance.
In one striking use of the method, reported online Sunday in Nature Biotechnology, mice were implanted with a human uterine tumor that was highly aggressive and resistant to many drugs. All of the treated animals were free of tumor cells after 70 days of treatment; the untreated mice were dead after a month.
... Cancer experts who were not involved with the research say that the new method is of great interest, but that many treatments that work well in laboratory mice turn out to be ineffective in patients.
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from National Geographic News
Top stealth-plane experts have re-created a radical, nearly forgotten Nazi aircraft: the Horten 2-29, a retro-futuristic fighter that arrived too late in World War II to make it into mass production.
The engineers' goal was to determine whether the so-called stealth fighter was truly radar resistant. In the process, they've uncovered new clues to just how close Nazi engineers were to unleashing a jet that some say could have changed the course of the war.
To replicate the Ho 2-29 late last year for a documentary, a team from the Northrop Grumman defense-contracting corporation used original Nazi blueprints and the only surviving Ho 2-29, which has been stored in a U.S. government facility for more than 50 years.
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from New Scientist
Have you ever experienced that eerie feeling of a thought popping into your head as if from nowhere, with no clue as to why you had that particular idea at that particular time?
You may think that such fleeting thoughts, however random they seem, must be the product of predictable and rational processes. After all, the brain cannot be random, can it? Surely it processes information using ordered, logical operations, like a powerful computer?
Actually, no. In reality, your brain operates on the edge of chaos. Though much of the time it runs in an orderly and stable way, every now and again it suddenly and unpredictably lurches into a blizzard of noise.
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