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Monday, January 26, 2009

Flip-Flop: Did the Moon Do a Turnabout?

By John Matson


SUSPECT CRATER: The Smythii basin was formed by an impact that a new study proposes could have reversed the moon's orientation. Other candidate craters dot the lunar surface as well.

For thousands of years only one side of the moon was visible to humankind as a result of synchronous rotation, a sort of orbital lockstep that keeps the moon rotating once for every lap it takes around Earth. Astronomers had to settle for this near-side view until 1959, when a Soviet craft took the first photographs of the moon's far side. But could the view from Earth have been different early in lunar geologic history?

In a paper in press for the journal Icarus, geophysicists Mark Wieczorek and Mathieu Le Feuvre of France's National Center for Scientific Research's Institute of Earth Physics in Paris postulate that our natural satellite was once rotated 180 degrees, with the current far side of the moon facing Earth. A large impact roughly four billion years ago could have temporarily disrupted the moon's rotation, the researchers say, allowing it to eventually settle back into so-called spin-orbit synchrony either in its original orientation or rotated 180 degrees. (Wieczorek says that the tidal bulges on the lunar surface induced by Earth's gravity, which deform the moon into an elongated shape that helps stabilize its position, would prevent the moon from easing into synchrony at any intermediate orientation.)

Wieczorek and Le Feuvre first examined the size and velocity necessary for a sufficiently spin-disrupting asteroidal or cometary strike, turning up a few possible candidates based on cratering records on the lunar surface.

"Just based on the physics, it's very, very, very probable that at least one and perhaps more of these impacts did this to the moon," Wieczorek says. "The second question, and this is the harder part, is finding if there's any evidence of this or not."

The researchers sought that evidence by examining the placement and age of craters across the lunar surface. If the moon's orientation had remained constant throughout its history, there should be more impact cratering on its western hemisphere, which is the leading hemisphere in the moon's orbit in its current orientation. (Wieczorek likens this to driving a car in a storm—more rain hits the front windshield than the rear.)

The analysis revealed that whereas the younger impact basins follow this pattern, the older ones tend to be found on the trailing side of the moon, indicating that the moon has swiveled 180 degrees about its axis since those ancient craters formed. According to their calculations, in fact, the arrangement of older impact basins near the now-trailing eastern hemisphere has less than a 0.3 percent probability of happening by chance.

A few caveats that Wieczorek and Le Feuvre are careful to note: Ages for most of the 46 impact basins studied are not well constrained, and some older basins might be obscured by ejecta from younger craters nearby, which would mean the current data set is incomplete. Better topographic maps now being pieced together by lunar orbiters such as India's Chandrayaan 1 and Japan's Kaguya could help clarify the historical record of asteroidal and cometary impacts.

H. Jay Melosh, a planetary scientist at the University of Arizona Lunar and Planetary Laboratory who has studied the effects of impacts on the moon's orientation, finds the new proposal quite plausible. Although Wieczorek and Le Feuvre's in-depth analysis of the cratering data may spark some arguments over the details, Melosh says, "the overall picture is both reasonable and well documented."

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Europe's Sexy New Gravity Satellite

By Clara Moskowitz

Goce

A sleek new European Space Agency satellite set to launch this year, perhaps as early as February, aims to map out the planet's gravitational field in unprecedented detail. The Gravity field and steady-state Ocean Circulation Explorer, or GOCE, will gather data useful for research in oceanography, solid Earth physics and climate change.

"ESA's gravity satellite will measure Earth's gravity from place to place around the globe to provide a uniform global picture," said GOCE project scientist Mark Drinkwater in a press release. "It will do this with a level of detail and accuracy never before achieved. This fundamental reference dataset will give access to new scientific insights into ocean circulation and its impact on climate, as well as into the structure of the interior of the Earth in critical locations such as earthquake and volcanic zones."

What goes up must come down. That simple explanation of gravity serves us well in most cases, but at a certain level, it breaks down. For example, the strength of Earth's gravity actually varies by small amounts at different spots around the planet.

GOCE will use ultrasensitive instruments called accelerometers to measure tiny variations in Earth's gravitational tug due to the planet's rotation, the positions of mountains and ocean trenches, and variations in the density of Earth's interior.

Orbiting low at just 155 miles above the surface of the planet, GOCE will compile its precise 3-D map of Earth's gravitational field over a period of about 20 months.

The information it gathers will also help scientists finally gauge accurate heights for major Earth features such as Mount Everest, for which today's best estimates vary by more than 16 feet.

"Measuring our planet's peaks using a standardized reference will help us better understand the Earth," said Bente Lilja Bye, research director from the Norwegian Mapping and Cadastre Authority.

"GOCE will result in an improved accuracy of the geoid and will facilitate the establishment of a unified global height system so that heights of the highest mountains in the world can be directly compared," she said. "Another benefit will be an improvement in our capabilities to predict the behavior of the Earth, and hence provide information needed to help mitigate disasters and economically damaging events."

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Dinosaurs could survive cold conditions

By Richard Gray, Science Correspondent

Dinosaur: researchers believe dinosaurs could have lived and reproduced in much colder climates than we orginally thought
Dinosaurs could have lived and reproduced in much colder climates than we orginally thought. Photo: Lonely Planet

Palaeontologists have unearthed a rich variety of dinosaur fossils in an area that would have been one of the most northerly regions of the world in the period just before the giant reptiles died out, between 65 and 68 million years ago.

At the time, the world was far warmer and the continents were still to move to their current positions. Northeastern Russia, where the remains have been found, would have been just 1,000 miles from the North Pole, inside what is now called the Arctic Circle. Average temperatures would have been around 50F (10C).

Fossil hunters found remains of duck billed dinosaurs, fossilised teeth belonging to relatives of the heavily armoured Triceratops and even teeth belonging to relatives of the giant meat eater Tyrannosaurus rex.

The palaeontologists, based at the Royal Belgian Institute of Natural Sciences, also found fragments of dinosaur egg shells alongside the Arctic dinosaur remains, providing the first proof the animals were able to reproduce in these relatively cold, northern climates.

Dinosaurs have typically been thought of as being tropical creatures, but the discovery suggests they were able to survive in far colder conditions than had been appreciated.

One of the most common theories for the extinction of the dinosaurs was that the global climate cooled to the point that the animals could not survive. But the new discovery suggests dinosaurs were capable of adapting to cold conditions.

Professor Pascal Godefroit, who led the research on the polar dinosaurs, believes they faced a far more speedy decline, most likely caused by a massive meteor impact around 66 million years ago.

"For the first time we have firm evidence that these polar dinosaurs were able to reproduce and live in those relatively cold regions," he said.

"There is no way of knowing for sure, but dinosaurs were probably warm blooded just like modern birds, which are the direct descendants of dinosaurs.

"We have no remains of cold-blooded reptiles such as turtles, crocodilians and lizards in that area which suggests it was too cold for them.

"The dinosaurs were incredibly diverse in polar regions – as diverse as they were in tropical regions. It was a big surprise for us."

Among the dinosaur remains to have been found at Kakanaut, in northeastern Russia, include fossils of bipedal herbivores known as Ornithopods along with larger, lumbering plant eaters, similar to Ceratop dinosaurs, known as Edmontonia.

Teeth belonging to small meat eaters, including the 6ft long Troodon, which carried retractable claws, and relatives of the Velociraptors made famous by Jurassic Park, known as Dromaeosaurids were unearthed.

Remains of large tyrannosaurid dinosaurs, relatives of the formidable Tyranosaurus Rex, were also discovered.

Previously the most northerly dinosaur remains to be found have been in Alaska, but scientists have always assumed the creatures migrated south during the winter months to avoid the cold and long periods of darkness.

Professor Godefroit and his team, however, now claim they have evidence to suggest dinosaurs were year round residents of high latitudes and fed on evergreen plants during the winter. They have reported their findings in the German journal Naturwissenschaften.

He believes that the findings that so many dinosaurs were living in relatively cold regions right up until the time they became extinct, provides strong evidence against theories that climate change gradually killed them off.

Instead he believes debris thrown up by the meteor impact that created the Chicxulub Crater, on the Yucatan Peninsula in Mexico, blanketed the atmosphere and reduced the amount of sunlight reaching the planet's surface.

This would have caused a dramatic reduction in the amount of plant life on the planet, which would have caused a rapid collapse in the food chain as the large plant eating dinosaurs died out, as well as the meat eaters that preyed upon them.

He said: "The meteor impact would have led to the equivalent of a global polar night that could have lasted for several years. Even the polar dinosaurs that were used to finding food in such conditions would have struggled for that length of time."

Robert Spicer, from the Open University, told the scientific journal Nature that the findings show that dinosaurs were far more robust than had been realised.

He said: "It makes me ask very serious questions about what could make animals that were resilient enough to live under these conditions to suddenly go extinct."

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Docs: Many Men Have "Small-Penis Syndrome"

(WebMD) Eighty-five percent of women are pleased with their partner's penis proportions — yet many normal men suffer "small-penis syndrome," urologists report.

Small-penis syndrome is the anxiety of thinking one's penis is too small — even though it isn't. It's a totally different condition from having a truly tiny tinkler, a condition known by the cold, clinical name of micropenis.

Urologists Kevan R. Wylie of Royal Hallemshire Hospital and Ian Eardley of St. James Hospital in Leeds, England, review the literature on penis size in the June issue of the urology journal BJU International. They urge doctors not to laugh away these very real worries over an imaginary defect.

"It is very common for men to worry about the size of their penis," Wylie says in a news release. "It is important that these concerns aren't dismissed as this can heighten concerns and anxieties."

Wylie and Eardley note that studies of penis size are remarkably consistent. The average erect penis is about 5.5 to 6.2 inches long and 4.7 to 5.1 inches in circumference at midshaft.

A truly diminutive dangler — a micropenis — is less than 2.75 inches long when erect, Wylie and Eardley calculate.

Few men suffer this condition. Yet 45 percent of men want a bigger penis, the researchers find. No wonder the Internet is rife with offers of "miraculous" penis-lengthening schemes.

There is slight evidence that some of them, such as the Phallosan extender system and the Penistretcher device, may result in slightly lengthening the
stretched length of a flaccid penis. But Wylie and Eardley note that there is far too little peer-reviewed research to know whether these devices — or
others like them — offer any real benefit.

Similarly, the researchers note that plastic surgeons have been touting
their ability to make a man's flaccid or erect penis larger. Again, they note, these techniques are unproven except for cases of true deformity. And they warn that serious complications may ensue.

Wylie and Eardley recommend that urologists take men's concerns seriously.
If education and counseling doesn't do the trick, they advise psychotherapy for men whose obsession over penis size is interfering with their lives.

By Daniel DeNoon
Reviewed by Louise Chang
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Charles Darwin's research to prove evolution was motivated by his desire to end slavery

By Richard Gray, Science Correspondent

Science historians Adrian Desmond and James Moore have compiled compelling new evidence which reveals Darwin was passionately opposed to slavery and this was the moral impetus behind his work.

Private notes and letters uncovered by the pair reveal that Darwin's opinions on slavery were far stronger than had previously been believed.

Notebooks from his five year voyage on HMS Beagle, during which Darwin first began to form his famous theories on natural selection, detail his revulsion at the slavery he witnessed in South America.

The historians have also discovered letters written by Darwin's sisters, cousins and aunts that reveal the family as highly active abolitionists. Darwin's grandfather and uncles were also key members of the anti-slavery movement.

The pair claim in a new book that Darwin partly chose to highlight the common descent of man from apes to show that all races were equal, as a rebuttal to those who insisted black people were a different, and inferior, species from those with white skin.

They say Darwin attempted to show that his theory of sexual selection, where traits seen as desirable but which give no competitive advantage to a species are passed down through generations, was responsible for differences in appearance between races of both animals and humans.

Professor James Moore, from the department of history of science at the Open University, said that Darwin originally shied away from tackling the origins of humans in his book On the Origin of Species, which was published in 1859, as it was a controversial subject.

"We are not trying to explain away all of Darwin's work as being due to his passion for emancipation, but our argument is that his passion for racial unity is what drove him to touch this untouchable and treacherous subject," he said.

"Darwin was finally goaded into starting his work on the origins of man in 1865 by a rising tide of scientific belief that the races were separate species."

The new book, called Darwin's Sacred Cause, examines notes that Darwin made during his voyage on the Beagle. After visiting Brazil he wrote of his disgust at the slavery he saw in the country.

From an entry on July 3 1832, just one year before the Slavery Abolition Act was passed in Great Britain, he said: "The state of the enormous slave population must interest everyone who enters the Brazils... I hope the day will come when they will assert their own rights & forget to avenge these wrongs."

In notebooks he used while drawing up his theory of natural selection, he also made references to slavery. He wrote: "Do not slave holders wish to make the black man other kind?... from our origin in one common ancestor we may be all netted together."

Darwin also describes the brutality of slavery in his best-selling journal about his Beagle voyage and recalls staying opposite an old lady near Rio de Janeiro who kept thumbscrews to crush the fingers of her female slaves. He also tells of how a young boy was whipped "thrice" for handing him a glass that was not clean.

Correspondence between Darwin and a Jamaican magistrate Richard Hill, a former slave who went on to oversee disputes between former slave owners and emancipated slaves, also reveals some of the naturalist's views.

He writes to Hill just a few months before publishing On the Origin of Species to congratulate him on his work for the "sacred cause of humanity".

Professor Moore claims that Darwin's family were instrumental in helping the biologist form his opinions on slavery. His grandfather was Josiah Wedgwood, who founded the famous china factory and was an active anti-slavery campaigner.

Darwin's uncles included Josiah Wedgwood II, an abolitionist MP, while his aunts, cousins and sisters wrote many letters and donated money to the cause.

Professor Moore added: "Darwin's mother died when he was eight years old, so his sisters brought him up with help from their Wedgewood cousins. He was under the influence of these highly principled and liberal thinking ladies who taught him about anti-cruelty and the sin of slavery."

Next month will mark the 200th anniversary since Darwin's birth, while in November scientists will celebrate 150 years since his seminal work On the Origin of Species was published.

Many supporters of Darwin's work have used his theories to argue against the existence of God and the need for religion, while the controversy that followed the publication of his work is now seen to have mainly been on religious grounds.

In fact, Darwin was a religious man until relatively late in his career, often shying away from speaking publicly about the controversy his research had provoked.

Professor Moore and his co-author Adrian Desmond will present their new theory at a lecture and book launch at Imperial College London on Monday 9 February.

Mr Desmond, an honorary research fellow at University College London, said: "Darwin doesn't overtly refer to slavery and racism as his motivation for writing Descent of Man and On the Origin of Species, but it is there lurking in the background.

"I don't think anyone has really looked at how strong his belief in anti-slavery was, and this could be why it has been overlooked.

"What he was saying was that if you accept evolution, then you don't accept the view that black people are a separate species. It is clear that he believed the same as his grandfathers – that slaves were men and brothers."

Professor Armand Leroi, an evolutionary biologist at Imperial College London who is presenting a documentary What Darwin Didn't Know on BBC 4 on Monday, said although the new theories outlined in the book did not change Darwin's achievements, it gave a fresh insight into his motivations.

He said: "We as evolutionary biologists tend to view Darwin as being very much motivated by the things that motivate us, which is the explanation for the diversity of all the things in the world.

"Origin of the Species is a classic scientific work as it has no obvious social agenda, although when you read the journal of his voyage on the Beagle it becomes clear he was horrified by the slavery he saw and how it weighs upon him."

The Darwin's Sacred Cause book launch takes place at 6pm on Monday 9 February 2009 in the Great Hall on Imperial College London's South Kensington campus.

Entry is by advance free ticket only. Tickets can be reserved by emailing events@imperial.ac.uk

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'Warrior Gene' Predicts Aggressive Behavior After Provocation


Individuals with the so-called "warrior gene" display higher levels of aggression in response to provocation. (Credit: iStockphoto/Viorika Prikhodko)

Individuals with the so-called “warrior gene” display higher levels of aggression in response to provocation, according to new research co-authored by Rose McDermott, professor of political science at Brown University. In the experiment, which is the first to examine a behavioral measure of aggression in response to provocation, subjects were asked to cause physical pain to an opponent they believed had taken money from them by administering varying amounts of hot sauce.

The findings are published in the Proceedings of the National Academy of Sciences. In addition to McDermott, the research team included Dustin Tingley of Princeton University, Jonathan Cowden of the University of California–Santa Barbara, Giovanni Frazetto from the London School of Economics, and Dominic Johnson from the University of Edinburgh. Their experiment synthesized work in psychology and behavioral economics.

Monoamine oxidase A is an enzyme that breaks down important neurotransmitters in the brain, including dopamine, norepinephrine, and serotonin. The enzyme is regulated by monoamine oxidase A gene (MAOA). Humans have various forms of the gene, resulting in different levels of enzymatic activity. People with the low-activity form (MAOA-L) produce less of the enzyme, while the high-activity form (MAOA-H) produces more of the enzyme.

Several studies have found a correlation between the low-activity form of MAOA and aggression in observational and survey-based studies. Only about a third of people in Western populations have the low-activity form of MAOA. By comparison, low-activity MAOA has been reported to be much more frequent (approaching two-thirds of people) in some populations that had a history of warfare. This led to a controversy over MAOA being dubbed the “warrior gene.”

The PNAS paper is the first experimental test of whether MAOA-L individuals display higher levels of actual behavioral aggression in response to provocation. A total of 78 subjects took part in the experiment over networked computers (all were male students from the University of California–Santa Barbara). Each subject (A) first performed a vocabulary task in which they earned money. Then they were told that an anonymous partner (B), linked over the network, could choose to take some of their earnings away from them. The original subject (A) could then choose to punish the taker (B) by forcing them to eat unpleasantly hot (spicy) sauce — but they had to pay to do so, so administering punishment was costly. In reality, the “partner” who took money away was a computer, which allowed the researchers to control responses. No one actually ingested hot sauce.

Their results demonstrate that

  • Low-activity MAOA subjects displayed slightly higher levels of aggression overall than high-activity MAOA subjects.
  • There was strong evidence for a gene-by-environment interaction, such that MAOA is less associated with the occurrence of aggression in the low-provocation condition (when the amount of money taken was low), but significantly predicted aggression in a high-provocation situation (when the amount of money taken was high).

The results support previous research suggesting that MAOA influences aggressive behavior, with potentially important implications for interpersonal aggression, violence, political decision-making, and crime. The finding of genetic influences on aggression and punishment behavior also questions the recently proposed idea that humans are “altruistic” punishers, who willingly punish free-riders for the good of the group. These results support theories of cooperation that propose there are mixed strategies in the population. Some people may punish more than others, and there may be an underlying evolutionary logic for doing so.

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Baby Beetles Get Through Water Efficiently, So Can Small Boats

By GreenerDesign Staff

PITTSBURGH, Pa. -- Inspired by the way beetle larvae wiggle to move across water, researchers at the University of Pittsburgh have developed a low-energy and low-maintenance system for moving small robots and boats in water.

The system, which uses electrical pulses in place of paddles, sails and motors, is designed for small boats and devices that monitor the water quality in reservoirs, oceans and other bodies of water. Such devices usually rely on propellers to move about.

Senior researcher Sung Kwon Cho was inspired to devise the system after reading about how beetle larvae make their way through water. Cho is also a professor of mechanical engineering and materials science in the university's Swanson School of Engineering.

To move across water, beetle larvae start off resting on the water, causing the surface tension to pull equally on all sides. To move forward, the beetles bend their backs downward, causing the tension behind them to change and the forward tension to pull them, using the energy within the water's surface to move them forward.



The electrical pulse system does the same thing, destabilizing the surface tension on one side or multiple sides of a small boat to propel it in the opposite direction or, as shown above, in a circle. In the above display, two electrowetting-on-dielectrics (EWOD) electrodes - indicated by the red circles - generate pulses, causing the boat to rotate.

The system has no moving parts, and the low-energy electrode that emits the pulse can be powered by batteries, radio waves or solar power.

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Row over scheme to 'fertilise' oceans

By Geoffrey Lean, Environment Editor

Scientists are planning this week to start a highly controversial experiment in changing the composition of the oceans, in apparent contravention of international law.

The experiment – to be conducted in the Southern Ocean – aims to create a bloom of plankton so big that it will be visible from outer space. But, at the last minute, the scheme has sailed into an international storm as environmentalists have called for it to be abandoned. The researchers – mainly from Germany and India, but including two Britons – plan to add some 20 tons of iron sulphate to a 186-square-mile patch of ocean about half way between Cape Horn and the Cape of Good Hope, to demonstrate a way both of combating global warming and of saving the whale.

As the waters are short of iron, this is expected to lead to an explosive growth of plankton, which will take up carbon dioxide from the air. The scientists hope that, when the plankton die and their bodies sink deep into the ocean, they will take the carbon with them, keeping it out of the atmosphere for centuries. Applied on a large enough scale, they believe this could help stave off climate change, while increasing food for whales. Commercial firms have already announced plans to make money from such schemes.

But other scientists are deeply concerned that the practice could have devastating unintended effects on the oceans, including killing off large areas of sea, and releasing methane and nitrous oxide, which are even more potent causes of global warming. They also fear that the plankton could absorb sunlight, heating up surface waters and hastening climate change.

Last May the UN's Convention on Biological Diversity banned the practice, allowing exceptions only for "small-scale scientific research studies within coastal waters". Nevertheless, the expedition – jointly organised by the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven and the National Institute of Oceanography in Goa, India – set off this month.

Alarmed environmentalists, led by the Canada-based ETC Group, urged Germany's Environment Minister, Sigmar Gabriel, to stop the experiment. The German government suspended it while legal and environmental reviews were carried out, and the scientists expect to hear the result early this week.

Dr Richard Lampitt of the University of Southampton's National Oceanography Centre, which has two scientists on board, says: "We desperately need to make this sort of experiment if we are going to make rational decisions in the future."

The Alfred Wegener Institute accuses objectors of "indulging in disruptive activities merely to draw attention to themselves".

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Smuggler Caught With Heads of 353 African Gray Parrots

Old plutonium found in dump

Plutonium found in a safeThe glass bottle containing the plutonium (right) was found inside a rusty safe (left).Anal. Chem.

The clean-up of a decommissioned US nuclear weapons plant has unearthed one of the oldest known samples of man-made plutonium.

Workers found roughly half a gram of weapons-grade plutonium-239 (Pu-239) in an abandoned safe at the Hanford Site in rural Washington state. Researchers at the nearby Pacific Northwest National Laboratory have dated the plutonium to roughly 1946, just two years after the United States tested its first nuclear device in the desert of New Mexico.

The sample is the second-oldest known man-made plutonium, according to Jon Schwantes, a research scientist at the laboratory and author on the paper, which appears online in the journal Analytical Chemistry1. The oldest sample, made in the early 1940s by Glen Seaborg of the University of California in Berkeley and his colleagues, is held by the Smithsonian in Washington.

Deadly trigger

Pu-239 is a staple of the world's nuclear arsenals. A few kilograms of the metal is all that is needed to make a fission device, and Pu-239 is commonly used in modern weapons as the 'primary', which triggers a more powerful secondary hydrogen blast.

But with a half-life of just 24,100 years, Pu-239 decays away too quickly to be found in nature. So in the 1940s, physicists had to learn how to make it themselves. They did so by burning uranium fuel in nuclear reactors, and chemically separating Pu-239 from the waste.

The contents of the bottle, found less than a mile from Schwantes' office, appear to be the final product of one of the earliest chemical separation processes. The half-gram of pure plutonium was dissolved in 400 millilitres of a lanthanum fluoride solution. That solution was the first clue, Schwantes says, because it hasn't been used in separation since the mid-1950s.

The second clue came from elemental makeup of the mix. For decades, the once pure plutonium in the bottle had been decaying back into uranium, and the ratio of uranium to plutonium gave an age of 61.6 ± 4.5 years. That made this plutonium among the earliest ever made, and meant that it had to have come from just a handful of reactors in the US.

Isotope trail

Giant reactors at the Hanford Site produced nearly all the plutonium used in the US nuclear arsenal, but the ratios of different plutonium isotopes pointed to a smaller reactor. Schwantes says that computer modeling showed a "near perfect match" with an experimental reactor near Oak Ridge, Tennessee, known as X-10. Historical documents showed that 96 "slugs" of X-10 fuel were sent to Hanford in 1944 before the site's large reactors were fully operational. The fuel was used to test new plutonium extraction techniques, and Schwantes now believes that this batch of plutonium was the upshot of those early tests.

Schwantes says that he believes that this "nuclear archeology" serves as an important example of how scientists can attribute small samples of nuclear material to a specific source. Such attribution could help reduce nuclear smuggling and nuclear terrorism because countries that produce the material will be held to account, he claims. "The countries originally responsible for this kind of material will feel responsible."

"What they are doing are very good measurements," says a scientist with the International Atomic Energy Agency in Vienna, who declined to be identified because of his ongoing work on nuclear safeguards. But, he adds, tracing modern nuclear material is a far trickier business.

Just 11 reactors were operating in the United States in 1950, and only four were being used for plutonium work. By contrast a modern sample could come from any one of hundreds of military and industrial reactors. In today's environment "you can narrow it down to several possible sources", the scientist says, "but you have no real proof."

Corrected:

The plutonium found at the Hanford site is the second oldest known sample, not the oldest as we stated in a previous version of this article. The piece has been corrected to reflect this.

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Solving Avalanches’ Mysteries

Janie Osborne for The New York Times

Ed Adams, right, and Andrew Slaughter conduct an experiment.

By JIM ROBBINS

BOZEMAN, Mont. — Not long ago, Ed Adams, a civil engineering professor, studied avalanches by setting them off with dynamite and studying their movement as they buried him, his instruments and his colleagues in a tiny shack.

Recently, though, Dr. Adams, a 58-year-old materials researcher, started a new and somewhat quieter phase of research, studying avalanches in the lab at Montana State University. A $2 million “cold lab” financed primarily by the National Science Foundation and the Murdock Charitable Trust and completed here in November allows Dr. Adams to replicate and control the uncontrollable field conditions of mountains in winter and understand in detail how snow behaves under widely varying conditions. The goal is to be better able to predict an avalanche.

Forecasting avalanches has always been as much an art as a science because of the wide variability of conditions, from time of day and year to type of snow, to slope and temperature.

“Snow seems simple, but it’s extraordinarily complex,” Dr. Adams said. “If I set a box of snow in the refrigerator and come back in an hour, it’s changed significantly. It’s almost always in a constant state of motion, and studying it is a moving target.” That is where the lab comes in, allowing researchers to vary the sky, sun and temperature to see how snow responds.

There have been 31 fatalities this winter season, 16 in the United States and 15 in Canada, including three snowmobilers in separate avalanches on Saturday in Idaho and Montana. The record in the United States is 35 in the winter of 2001-02. Three of this winter’s fatalities occurred within the boundaries of ski trails in commercial skiing areas, which is highly unusual, because of the careful forecasting and control work done in skiing areas.

“The number of fatalities we have had shows they’re a difficult phenomenon for us to understand,” said Karl Birkeland, an avalanche scientist at the Forest Service’s National Avalanche Center here. “There’s definitely a need to better understand them.”

Montana State is well situated for the study of avalanches. There are four Class A avalanche zones — the most severe — at nearby skiing areas, and numerous backcountry locations for study.

For years, Dr. Adams and his colleagues set up their instruments in a small shack on a steep slope at Bridger Bowl, about 15 miles from the university, and sent another researcher up the slope to ignite a two-pound bomb that set off an avalanche.

As the wall of snow rumbled around or over the shack, Dr. Adams, bundled up against the cold, watched his laptop record information on velocity, depth, flow and temperature. He estimates he survived dozens of such self-inflicted avalanches.

In the cold lab, however, where the temperature is 8 degrees below zero, the focus is on a one-square-meter panel, brilliantly lighted by an artificial sun and watched over by an icy artificial sky that can be widely varied to replicate different winter conditions. Wearing his puffy down jacket, wool hat and sunglasses, Dr. Adams shows how he can reproduce the wide range of conditions found on mountain slopes and create different types of snow. “We want to understand what conditions cause the change in the crystalline structure and the bonding between crystals,” he said. It is the missing part of the puzzle of understanding avalanches.

Once he and his students and colleagues have created the snow crystals under certain conditions, they put them under the microscope to see what conditions made for the strongest or weakest layers. Snow layers are the key to predicting avalanches.

The biggest cause of avalanches is a weak layer of snow on a slope covered by solid layers, Dr. Adams said. “The weak layers are faceted crystals, very smooth and unbonded to each other,” almost like ball bearings, he said. Strong layers have stronger bonds between crystals, which makes them more stable.

“It’s like a layer cake with very weak frosting,” Dr. Adams said. When something causes the weak layer, usually less than an inch thick, to give way, the strong layer or layers — there can be dozens, some of them feet thick — go with it. Even skiing at low altitudes can fracture a weak layer and set off an avalanche far above. Contrary to conventional wisdom, sound, unless it is from an explosion, does not set off avalanches.

Some ski areas offer skiers free skiing in exchange for “boot packing” — trampling weak layers with their boots to harden them.

The key to improving forecasting, Dr. Adams said, is understanding the surface layer, where sun and cold cause the snow crystals to change. Understanding the energy transfer on the surface can provide information about what is going on underneath.

As usual, weak layers are the key to this winter’s avalanches. “We’ve had weak layers laid down early in the season,” Mr. Birkeland said. “Then a big storm puts a whole lot of load on the weak base.”

Heavy, dense snow makes it harder for skiing areas to use ordnance to set off slides for safety reasons; instead the avalanches happen on their own.

Data collected by Dr. Adams in the cold lab on the microscopic level is added to data gained in work setting off avalanches, and to information from weather conditions and from daily snow samples gathered by the ski patrol at the Yellowstone Club, a private skiing area near Yellowstone Park where he is doing research.

Dr. Adams’s team plans to combine that data with results from a thermal imaging program developed with Thermal Analytics, a company based in Houghton, Mich. The system, which creates far more detailed data than any previous modeling, is expected to greatly enhance forecasting. It will go into use here in Bozeman in two weeks.

“We have tons of people out in the backcountry” pursuing various forms of recreation, said Mark Staples, a researcher who forecasts conditions for the avalanche center for the Gallatin National Forest and who will use the new program. “There’s a lot of variability spatially and temporally. Some days it’s safe, and some days less so. But we only have three people forecasting, so the more we can use what Ed’s doing, the more we can forecast over a wider area.” Right now forecasting is based on field observations and weather forecasts.

Based in the jagged mountains of the northern Rockies, the avalanche center at Montana State was founded by Charles Bradley and John Montagne, veterans of the Army’s Tenth Mountain Division who came here after World War II.

Other major avalanche centers include the Swiss Federal Institute for Snow and Avalanche Research in Davos, the world’s largest, and the Nagaoka Institute for Snow and Ice Studies in Japan. The University of Calgary and the University of British Columbia have smaller but highly regarded programs.

Avalanche prediction has become more important as many more people ski and snowmobile in the backcountry. Until the 1970s, an average of only five people died each year in avalanches in the United States. In the 1990s, with more skiers and snowmobilers on the slopes, the average increased to 20. In the last decade, the deaths have averaged 28 a year, but experts say the deaths have not increased as quickly as the number of backcountry users.

The jury is still out on the best way to survive an avalanche. Some researchers say the most critical thing is to create a pocket in front of the face to breathe while waiting for rescue. “I would swim, though,” Dr. Adams said. “Get prone in the snow and stay on top.” A new product called an avalanche balloon system is carried by some skiers. If they get caught in an avalanche, they can pull a ripcord that inflates balloons and is said to keep them afloat on the surface of the snow.

Dr. Adams traces his zeal to understand avalanches to his days as a bartender and ski bum at Alta, a ski resort in Utah. “The lodge I was working in got hit by an avalanche,” he said, “and it took a whole wing out and blew cars from the parking lot across the road. It was impressive.”

Avalanche stories often have much worse endings. Eight snowmobilers were killed in an accident in British Columbia in December. In 2003 in British Columbia just north of Glacier National Park, 17 teenage cross-country skiers were buried as they skied across a meadow; 10 survived. Tragedy has struck the researchers as well. One of Dr. Adams’s former graduate students, Blake Morstad, was killed in a slide while skiing in Idaho’s backcountry. A documentary, “A Dozen More Turns,” recounts the story.

Despite the danger of avalanches, Dr. Adams says he may one day return to doing research from the inside of an avalanche. “I’d like to go back,” he said. “But for me understanding the metamorphosis of snow in the cold lab is every bit as interesting.”

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Colleges turn french fry oil into fuel

College students have begun making biodiesel fuel by converting used cooking oil from the dining hall

College students have begun making biodiesel fuel by converting used cooking oil from the dining hall (Newsday / David L. Pokress)

DAYTON, Ohio - Forgive the students at Sinclair Community College if they get the munchies when they pass the tractors that cut grass, blow leaves or sweep snow on campus: Oil that once cooked french fries and onion rings is being used to power the vehicles.

Students have begun making biodiesel fuel by converting used cooking oil from the dining hall. Biodiesel saves the school a little money on gasoline, gives the students lessons in engineering and chemistry, and removes oil from the waste stream.

"It ends up as a product that is more friendly to the environment. And we're teaching with it," said Woody Woodruff, director of facilities at the 65-acre campus.

Sinclair is among a growing number of colleges nationwide making their own biodiesel, an alternative fuel produced from renewable oilseed crops, such as canola or soybean, or from used vegetable oil and other fats. The concept is being driven by greater environmental awareness among students.

The State University of New York melted down a 900-pound butter sculpture from the state fair last summer to help power its vehicles. Biodiesel accounts for about 8 percent of the fuel used on campus.

Dickinson College in Carlisle, Pa., produces 50 to 150 gallons of biodiesel each week to power campus lawn mowers, a garbage truck and farm equipment. The school has more than doubled its capacity of biodiesel, growing from 20-gallon to 54-gallon batches, while biodiesel byproducts are being used in a composting research project at the school's organic farm and to make soap sold in the campus bookstore.

At the University of Kansas, biodiesel fuels lawn mowers, backhoes, front-end loaders and other construction equipment. It is also used as a solvent to clean parts and tools and to heat a motor-pool building.

When the school began making biodiesel in September 2007, two people were involved. Now there are 25.

Neil Steiner, an architectural engineering student, volunteered to work on the project last year and is now a paid lab employee.

"I'm really into green buildings, and it was the greenest thing I could get my hands on," said Steiner, 22, of Tulsa, Okla.

Most colleges make biodiesel by chemically converting used cooking oil from campus dining halls. The oil is transformed through a process called transesterification, which removes glycerine and adds methanol, leaving a thinner product that can power a diesel engine. Biodiesel can also be blended with petroleum diesel.

When a question was posted in November on the online discussion board of The National Association of College & University Food Services asking what dining halls were doing with their fryer oil waste, the board was quickly flooded with responses. Schools said they were either using the oil to make biodiesel or selling it to companies for that purpose.

Estimated U.S. sales of biodiesel have jumped from 75 million gallons in 2005 to 700 million gallons last year.

Sinclair students turn out two batches of biodiesel a week. As of December, they had produced about 100 gallons. With the price of diesel fuel hovering around $2.50 a gallon and the cost of making biodiesel $1 a gallon, the students saved the school a modest $150.

"It's a gesture," said Bob Gilbert, head of Sinclair's center for energy education. "Our first goal is education."

Sam Spofforth, executive director of Clean Fuels Ohio, a statewide group that promotes the use of renewable fuels, said the interest in biofuels among college students should create a pipeline of talent and energy for commercial biodiesel production.

"They realize this is the wave of the future," Spofforth said. "There is going to be a tremendous need for educated people to move into these industries."

Steiner estimates he spends 20 hours a week on the University of Kansas biodiesel project, which he works on between classes. He hopes to use his experience after he graduates, perhaps as a consultant helping biodiesel companies obtain materials and funding.

"We make it, we test it and we distribute it to different places on campus," Steiner said. "We really get our hands on all of it. It really puts you in a practical situation."

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