Apr 5, 2012

Cannibalistic Galaxy With a Powerful Heart

Observations by two of the European Space Agency's space observatories have provided a multi-wavelength view of the mysterious galaxy Centaurus A.

The new images, from the Herschel Space Observatory and the XMM-Newton x-ray satellite, are revealing further hints about its cannibalistic past and energetic processes going on in its core.

At a distance of around 12 million light years, Centaurus A is the closest large elliptical galaxy to our own Milky Way. It has been marked as unusual since shortly after its discovery in the 19th century due to a thick lane of dust across its centre -- an unusual feature for an elliptical galaxy. But it wasn't until a century later that the galaxy's true nature was revealed.

Emanating from its core are two massive jets of material streaming from a massive black hole in the heart of Centaurus A. When observed by radio telescopes, the jets stretch for up to a million light years, though the Herschel and XMM-Newton results focus on the inner regions.

"Centaurus A is the closest example of a galaxy to us with massive jets from its central black hole," explained Prof Christine Wilson of McMaster University, Canada, who is leading the study of Centaurus A with Herschel. "Observations with Herschel, XMM-Newton and telescopes at many other wavelengths allow us to study their effects on the galaxy and its surroundings."

Strong radio emission is caused by electrons travelling at close to the speed of light through strong magnetic fields, and is so bright that the jets are even visible in the far-infrared images from the Herschel Space Observatory. As well as the jets, the images from this infrared observatory also show a twisted disc of dust near the galaxy's centre.

This odd shape is strong evidence that Centaurus A underwent a cosmic collision with another galaxy in the distant past. The colliding galaxy was ripped apart to form the warped disc, and the formation of young stars heats the dust to cause the infrared glow seen by Herschel.

Such collisions often result in shells and rings of gas and dust, and Centaurus A is no exception. Herschel observations have now confirmed the presence of two clumps of dust that seem to be lined up with the two lobes of the jets.

"The apparent alignment of two clumps with the two jets now seems to be a cosmic coincidence, and it appears that the dust originated from one of the colliding galaxies." explained Dr Robbie Auld, of Cardiff University. "Unlike most dust Herschel sees, which is heated by nearby star formation, the dust in these clumps is being heated by old stars in Centaurus A itself, up to 50,000 light years away."

In x-rays the effect of the two jets of material is clearly visible. Showing the presence of extremely hot gas, the images from the XMM-Newton x-ray satellite clearly show the axis of the one of the jets. While the other jet itself is not seen in by XMM-Newton, the gas it is ploughing into is shocked and heated to very high temperatures, creating a bright x-ray glow.

"XMM-Newton is the observatory most suited to detecting extended weak X-ray emission, often allowing us to see halos around galaxies for the first time," notes Norbert Schartel, XMM-Newton Project Scientist.

In the centre of the galaxy, the massive black hole is also having an effect on its immediate surroundings. The material around it glows brightly in x-rays, but there Herschel has identified an apparent deficit of dust within a few thousand light years of the black hole.

Read more at Science Daily

Quantum Computer Built Inside a Diamond

Diamonds are forever -- or, at least, the effects of this diamond on quantum computing may be. A team that includes scientists from USC has built a quantum computer in a diamond, the first of its kind to include protection against "decoherence" -- noise that prevents the computer from functioning properly.

The demonstration shows the viability of solid-state quantum computers, which -- unlike earlier gas- and liquid-state systems -- may represent the future of quantum computing because they can be easily scaled up in size. Current quantum computers are typically very small and -- though impressive -- cannot yet compete with the speed of larger, traditional computers.

The multinational team included USC Professor Daniel Lidar and USC postdoctoral researcher Zhihui Wang, as well as researchers from the Delft University of Technology in the Netherlands, Iowa State University and the University of California, Santa Barbara. Their findings will be published on April 5 in Nature.

The team's diamond quantum computer system featured two quantum bits (called "qubits"), made of subatomic particles.

As opposed to traditional computer bits, which can encode distinctly either a one or a zero, qubits can encode a one and a zero at the same time. This property, called superposition, along with the ability of quantum states to "tunnel" through energy barriers, will some day allow quantum computers to perform optimization calculations much faster than traditional computers.

Like all diamonds, the diamond used by the researchers has impurities -- things other than carbon. The more impurities in a diamond, the less attractive it is as a piece of jewelry, because it makes the crystal appear cloudy.

The team, however, utilized the impurities themselves.

A rogue nitrogen nucleus became the first qubit. In a second flaw sat an electron, which became the second qubit. (Though put more accurately, the "spin" of each of these subatomic particles was used as the qubit.)

Electrons are smaller than nuclei and perform computations much more quickly, but also fall victim more quickly to "decoherence." A qubit based on a nucleus, which is large, is much more stable but slower.

"A nucleus has a long decoherence time -- in the milliseconds. You can think of it as very sluggish," said Lidar, who holds a joint appointment with the USC Viterbi School of Engineering and the USC Dornsife College of Letters, Arts and Sciences.

Though solid-state computing systems have existed before, this was the first to incorporate decoherence protection -- using microwave pulses to continually switch the direction of the electron spin rotation.

"It's a little like time travel," Lidar said, because switching the direction of rotation time-reverses the inconsistencies in motion as the qubits move back to their original position.

The team was able to demonstrate that their diamond-encased system does indeed operate in a quantum fashion by seeing how closely it matched "Grover's algorithm."

The algorithm is not new -- Lov Grover of Bell Labs invented it in 1996 -- but it shows the promise of quantum computing.

The test is a search of an unsorted database, akin to being told to search for a name in a phone book when you've only been given the phone number.

Sometimes you'd miraculously find it on the first try, other times you might have to search through the entire book to find it. If you did the search countless times, on average, you'd find the name you were looking for after searching through half of the phone book.

Mathematically, this can be expressed by saying you'd find the correct choice in X/2 tries -- if X is the number of total choices you have to search through. So, with four choices total, you'll find the correct one after two tries on average.

A quantum computer, using the properties of superposition, can find the correct choice much more quickly. The mathematics behind it are complicated, but in practical terms, a quantum computer searching through an unsorted list of four choices will find the correct choice on the first try, every time.

Read more at Science Daily

Labrador Retriever Adopts Duckling

A duckling whose mother was mauled to death by a fox has been adopted by a Labrador retriever, according to Yahoo News.

In true Disney-like fashion, the duck even has a name, "Dennis." It apparently was less than a week old when tragedy struck, but 4-year-old Fred the dog saved the day. Fred's owner, Jeremy Goldsmith, also was a good samaritan, permitting the new feathered pet.

Dogs may not always take a shine to cats, but they do seem to hook up with all sorts of species. One of my favorite such stories in recent years was about a pregnant dog that nursed a hurt squirrel back to health. That was perhaps more motherly instinct.

In this case, Fred found orphaned Dennis and licked the little duckling clean. A friendship must have been forged in that moment, as the unlikely mates sleep together, play together and even go swimming in the local pond, according to the Daily Mail.

I'd probably do such romping too if I lived where they dwell. The animals and Goldsmith all reside at Mountfitchet Castle in Stansted, Essex UK.

Goldsmith told the Daily Mail, "It is amazing to see the two of them together. When we found Dennis he was quite frail and he clearly would not have survived another day on his own."

He continued, "Fred, who has always been extremely loving, went straight up to him and began to lick the little bird clean. Since then Dennis has not stopped following him around and Fred has pretty much adopted him."

"Dennis snuggles up to Fred at night, he will clamber up on top of him and they even go swimming together - but Fred is a lot less graceful in the water. I don't think the duckling would have made it without Fred - his loving nature really does make a difference."

Read more at Discovery News

Earth's Orbit Blamed for Ancient Hot Spells

About 55 million years ago, an intense heat wave hit the planet. Earth's surface temperature surged by 9 degrees Fahrenheit (5 degrees Celsius). Then, after a relatively short time, the heat subsided, only to be followed by at least two similar, but smaller heat waves.

Based on chemical clues preserved in rocks, scientists believe a surge of carbon dioxide warmed the planet. But where did all of this greenhouse gas come from?

A team of scientists is proposing that it came from the melting of permafrost, frozen soil packed with organic matter, after cycles in the Earth's orbit warmed up the areas near the poles. The melting released a massive amount of carbon into the atmosphere, keeping reflected sunlight from escaping and causing the heat wave.

Previously, other scientists have theorized that the release of the carbon compound methane trapped in marine sediments — in a form known as methane hydrates — changed the atmosphere. But the study published in the April 5 issue of the journal Nature argues that not enough methane would have been released to account for the magnitude of the warming.

Other theories include a comet impact, extensive fires, or the drying of shallow continental seas — "all these difficult ideas," said study researcher Mark Pagani, a professor at Yale University. None of these explain the sequence of progressively smaller heat waves that followed, Pagani and his colleagues argue.

Examining a rock outcrop near Gubbio, Italy that contains evidence of these heat waves, also known as hyperthermals, the team found they lined up with cycles in the Earth's orbit.

The path of Earth around the sun and the planet's orientation can vary slightly in cycles that last up to 100,000 years. The researchers found that the timing of three large hyperthermals — beginning about 55 million years ago — aligned with periods when the tilt of the Earth's axis was greatest and when the planet's orbit was most eccentric (that is, least circular).

This combination meant the high latitudes — the area closest to the poles — had warmer or longer summers, "with the potential to thaw vast areas of permafrost once a warming threshold is reached," wrote the researchers. The cycle became self-reinforcing, as more carbon entering the atmosphere encouraged more warming, which encouraged more melting and the release of more carbon.

"Then our climate models show if you have permafrost and you warm the temperatures slowly, there is sort of a sweet spot in the model: When you cross it, the whole thing just goes," Pagani said.

Modern discussions of melting permafrost focus on the Arctic. But about 50 million years ago, the world was warmer overall than it is now, and Antarctica was not yet ice-covered, so the researchers argue that the southernmost continent probably had its own large stock of carbon tucked away in the permafrost.

This process produced the successive hyperthermals, the team suspects: After a warming stint lasting some 10,000 years, the carbon from the permafrost would be depleted, resulting in atmospheric carbon dioxide that stuck around for about 200,000 years until natural processes drew it out, cooling the planet down, according to Pagani.

Then, about 1 million years later, the process most likely repeated itself, but this time with less permafrost available to melt. This led to a smaller warming pulse, until the hyperthermals ran themselves out, he said.

Read more at Discovery News

Apr 4, 2012

September 11 mastermind Khalid Sheik Mohammed facing death penalty

Khalid Sheikh Mohammed and four alleged co-conspirators were referred by President Barack Obama's administration to a military tribunal at the Guantánamo Bay naval base in Cuba.

In what has frequently been trailed as "the trial of the century", they will soon stand accused of committing multiple counts of terrorism, hijacking and murder in violation of the law of war by devising the era-defining attacks on the American mainland.

"The charges allege that the five accused are responsible for the planning and execution of the attacks of September 11, 2001, in New York and Washington DC, and Shanksville, Pennsylvania, resulting in the killing of 2,976 people," the Defence Department announced in a statement.

The full extent of their alleged crimes are detailed in an 88-page dossier listing every victim of the attacks by name. The charges were referred to a capital military commission, meaning that "if convicted, the five accused could be sentenced to death," the department said.

Mohammed, a 46-year-old Kuwaiti long known by US officials as "KSM", has been held at the base's Camp Delta prison for the past six years. He is alleged to have confessed that he was he "was responsible for the 9/11 operation from A to Z" after extensive interrogation.

He was tortured by "waterboarding" 183 times – more than any other Guantánamo detainee. The controversial technique in which water is poured on a suspect's face to simulate drowning, has since been banned by the Obama administration.

Mohammed will appear in court at the base for arraignment within 30 days, alongside Saudi Arabians Walid bin Attash and Mustafa al-Hawsawi, Ramzi bin al-Shibh of Yemen and Pakistani Ali Abd al-Aziz Ali. Their full trials are then expected to commence within months.

The fate of the five men will ultimately be decided by a jury of 12 military officers drawn from across America's armed forces. Under US military law, the officers must vote unanimously for the death penalty to be imposed.

Mr Obama’s aides will hope that the trial, which is set to commence amid his likely election campaign against Mitt Romney, will boost his chances of being returned to the White House by highlighting his crackdown on al-Qaeda and the assassination of Osama bin Laden.

In an attempt to move away from the controversial military tribunals, which were created by President George W. Bush after the September 11 attacks, Mr Obama originally made a high-profile effort to hold the trials in New York's civilian courts.

However, the notion that Mohammed should be brought within feet of the site where his alleged attack killed thousands under the collapsed towers of the World Trade Centre prompted outrage among Republicans, who blocked the plans in Congress.

After his capture in Pakistan in 2003, Mohammed was transferred over the next three years between a series of secret American bases around the world, as the CIA interrogated him for information on al-Qaeda's international terror network.

Moved to Guantánamo Bay in 2006, he allegedly accepted full responsibility the following year for September 11 and more than a dozen other plots, including plans to assassinate Pope John Paul II and former US presidents Bill Clinton and Jimmy Carter.

Mohammed is also alleged to have boasted that he personally beheaded Daniel Pearl, a reporter for the Wall Street Journal who was kidnapped in Pakistan in 2002, with his "blessed right hand".

Prosecutors allege that for two years Mohammed was in frequent contact with Mohammed Atta, the leader of the 19 September 11 hijackers. He is alleged to have provided Atta and his team with money before giving the orders to go ahead with the "Planes Operation".

Read more at The Telegraph

Game Changer for Evolutionary Theory?

A new hypothesis posed by a University of Tennessee, Knoxville, associate professor and colleagues could be a game changer in the evolution arena. The hypothesis suggests some species are surviving by discarding genes and depending on other species to play their hand.

The groundbreaking "Black Queen Hypothesis" got its name from the game of Hearts.

In Hearts, the goal is to avoid "winning" the Queen of Spades (the Black Queen), which is worth a lot of points. Subsequently, players allow others to take the high-point card while they enjoy low-score tallies.

This same premise applies in evolution, the scientists say.

According to the hypothesis, evolution pushes microorganisms to lose essential functions when there is another species around to perform them. This idea counters popular evolutionary thinking that living organisms evolve by adding genes rather than discarding them.

"A common assumption about evolution is that it is directed toward increasing complexity," said Erik Zinser, associate professor of microbiology. "But we know from analysis of microbial genomes that some lineages trend toward decreasing complexity, exhibiting a net loss of genes relative to their ancestor."

Zinser's opinion piece is published in mBio, the online open-access journal of the American Society for Microbiology. Jeffrey Morris and Richard Lenski of Michigan State University are co-authors. Morris was Zinser's doctoral student at UT.

The authors formed their theory after studying photosynthetic bacteria called Prochlorococcus.

"This marine microorganism continued to mystify us because it is the most common photosynthetic organism on Earth, but it is extremely difficult to grow in pure culture," Zinser said. "A major reason for this difficulty is that Prochlorococcus is very sensitive to reactive oxygen species such as hydrogen peroxide and relies on other bacteria to protect them by breaking down these toxic substances for them."

Prochlorococcus had once performed this function itself, but natural selection decided it was too costly, like carrying the Queen of Spades, and discarded this ability. Instead Prochlorococcus benefits from the hard work of others within its community allowing it to concentrate its energies elsewhere -- such as multiplying.

The hypothesis offers a new way of looking at complicated, interdependent communities of microorganisms.

"We know that certain microbial activities, such as hydrogen peroxide scavenging, are 'leaky,' meaning their impacts extend beyond the cell and into the environment," Zinser said. "What the hypothesis suggests is that this leakiness can drive a community toward greater interdependence, even if some members are unwitting participants in this process."

This interdependence could lend itself to vulnerabilities. The scientists say the work highlights the importance of biological diversity, because if rare members are lost, "the consequences for the community could be disastrous." This would be analogous to attempting to play Hearts without the Queen of Spades.

Read more at Science Daily

Shaggy T. Rex Cousin Was Heftiest Feathered Dino

A 3,086-pound shaggy tyrannosaur was the world's largest known feathered animal -- living or extinct -- according to a paper in the latest issue of Nature.

The newly unearthed tyrannosaur, named Yutyrannus huali or "beautiful feathered tyrant," lived about 125 million years ago in northeastern China. The over 29-foot-long non-avian dinosaur, represented by three specimens, is considerably smaller than its infamous relative T. rex, but some 40 times the weight of the largest previously known feathered dinosaur, Beipiaosaurus.

"The largest specimen preserves feathers on the tail, and two smaller specimens preserve feathers over the neck, on the forelimbs, near the pelvis, and even feet," lead author Xing Xu, a professor at Beijing's Institute of Vertebrate Paleontology and Paleoanthropology, told Discovery News.

Xu and his colleagues analyzed the remains of the three dinosaurs and discovered that patches of filamentous structures were near the bones on the slabs containing the specimens. The researchers believe that when the dinosaurs were alive, these simple structures would have been more like the fuzzy down of a modern baby chick than the stiff plumes of an adult bird.

The feathers likely served two functions: insulation and decoration.

"The size, structure and extent of the feathers suggests that they would have formed a shaggy body covering that would have had at least some insulating function," co-author Corwin Sullivan told Discovery News. Sullivan is a Canadian paleontologist now based at the Beijing institute.

Large animals, like elephants, are usually not feathery or furry. That is because these beasts have a tendency to overheat. The new dinosaur, however, lived during the middle part of the Early Cretaceous, when temperatures are thought to have been relatively cool.

Previously it was thought that only certain smaller dinosaurs were feathered. The scientists still think that feathers first emerged in a smaller dinosaur, and that larger feathered dinos only came along later.

"However, that doesn't mean that small feathered dinosaurs disappeared," Sullivan said. "New small species continued to appear as well."

Some of these smaller species eventually evolved into today's modern birds.

This meat-loving non-avian dinosaur, however, was no tiny songbird. Like T. rex, it appears to have been a fearless hunter.

Read more at Discovery News

Young Mammoth Likely Butchered by Humans

A juvenile mammoth, nicknamed "Yuka," was found entombed in Siberian ice near the shores of the Arctic Ocean and shows signs of being cut open by ancient people.

The remarkably well preserved frozen carcass was discovered in Siberia as part of a BBC/Discovery Channel-funded expedition and is believed to be at least 10,000 years old, if not older. If further study confirms the preliminary findings, it would be the first mammoth carcass revealing signs of human interaction in the region.

The carcass is in such good shape that much of its flesh is still intact, retaining its pink color. The blonde-red hue of Yuka's woolly coat also remains.

"This is the first relatively complete mammoth carcass -- that is, a body with soft tissues preserved -- to show evidence of human association," Daniel Fisher, curator and director of the University of Michigan's Museum of Paleontology, told Discovery News.

Fisher, who is also a professor, worked with an international team of experts to analyze Yuka. French mammoth hunter Bernard Buigues of the scientific organization "Mammuthus" saved the specimen from falling into the hands of private collectors.

Although carbon dating is still in the works, the researchers believe Yuka died at least 10,000 years ago, but may be much older. The animal was about 2 ½ years old when it died.

Fisher described what likely happened on that fateful day:

"It appears that Yuka was pursued by one or more lions or another large field, judging from deep, unhealed scratches in the hide and bite marks on the tail," Fisher said. "Yuka then apparently fell, breaking one of the lower hind legs. At this point, humans may have moved in to control the carcass, butchering much of the animal and removing parts that they would use immediately.

"They may, in fact, have reburied the rest of the carcass to keep it in reserve for possible later use. What remains now would then be 'leftovers' that were never retrieved."

He explained that the removed parts include most of the main core mass of Yuka's body, including organs, vertebrae, ribs, associated musculature, and some of the meat from upper parts of the legs. The lower parts of each leg and the trunk remain intact.

Buigues added that it appears the humans were particularly interested in the animal's fat and its large bones, which they kept close to the body of the carcass. He believes it is possible that a ritual may have taken place involving the bones.

Kevin Campbell of the University of Manitoba also studied Yuka. Campbell famously published the genetic code of mammoth hemoglobin a few years ago.

"Most permafrost-preserved mammoth specimens consist solely of bones or bone fragments that currently provide little new insight into the species' biology in life, even if DNA can be extracted and sequenced from these samples," Campbell said. "This extremely rare finding of a near complete specimen, like the discovery of the baby mammoth Lyuba in 2007, will be a boon to researchers as it will help them link observed phenotypes (morphological features that we can see) with genotype (DNA sequences)."

Read more at Discovery News

Saturn's Smashed-Up Moon Mystery Solved

Saturn's bizarre two-tone moon, Iapetus, wears a six-mile high chain of mountains around its equator. Now scientists have a theory that explains why.

It turns out the moon may have had its own moon. A new study shows that after a billion years or so, the moon's moon lost a gravitational tug-of-war with Iapetus and got shredded into a debris ring. Over time, the chunks were pulled to the surface of Iapetus, where they neatly piled up along the equator.

"I don't think you can ever get a volcanic eruption to look like this ridge, perfectly aligned on the equator on a body that has not other evidence for internal activity. Nor does it look like any other tectonic or fault structure I have ever seen in the solar system in its perfect symmetry," planetary scientist William McKinnon with Washington University in St. Louis, told Discovery News.

"I've always felt that its precise position on the equator really demanded an almost astronomical explanation -- it wasn't simply a fault or an ordinary mountain range or a product of volcanism of any sort. There's no sign of geologic activity," McKinnon said.

Scientists have been trying to figure out how the mountain ridge formed ever since they got a close-up view of Iapetus' rugged topography from NASA's Saturn-orbiting Cassini spacecraft.

"We hadn't seen anything like this," Andrew Dombard, with the University of Illinois' Earth and Environmental Sciences department, told Discovery News. "It's taken a while for our ideas to catch up with what the observations are showing us. The ridge itself is a massive wall that sits on the surface of Iapetus."

"This actually explains more of the observations than the other (computer) models," he added.

Scientists theorize that the 930-mile (1,500-kilometer) wide Iapetus once spun faster than it does today, which kept its small sub-satellite moving outward, much like Earth's moon is moving away from our planet today.

Over time, Saturn's clutch on its large outer moon tightened, causing Iapetus' rotational spin to slow. That in turn shifted the tidal balances between Iapetus and its satellite, which eventually got reeled in like a fish on a line. At some point, the moon's moon experienced so much force that it blasted apart.

Read more at Discovery News

Apr 3, 2012

New Light Shone On Photosynthesis

Photosynthesis is one of the fundamental processes of life on Earth. The evolutionary transition from anoxygenic (no oxygen produced) to oxygenic (oxygen-producing) photosynthesis resulted in the critical development of atmospheric oxygen in amounts large enough to allow the evolution of organisms that use oxygen, including plants and mammals.

One of the outstanding questions of the early Earth is how ancient organisms made this transition. A team of scientists from Arizona State University has moved us closer to understanding how this occurred, in a paper recently published in the Proceedings of the National Academy of Sciences. The paper is authored by James Allen, JoAnn Williams, Tien Le Olson, Aaron Tufts, Paul Oyala and Wei-Jen Lee, all from the Department of Chemistry and Biochemistry in ASU's College of Liberal Arts and Sciences.

Plants and algae, as well as cyanobacteria, use photosynthesis to produce oxygen and "fuels," the latter being oxidizable substances like carbohydrates and hydrogen. There are two pigment-protein complexes that orchestrate the primary reactions of light in oxygenic photosynthesis: photosystem I and photosystem II.

"In photosynthesis, the oxygen is produced at a special metal site containing four manganese and one calcium atom connected together as a metal cluster," explains professor James Allen. "This cluster is bound to the protein called photosystem II that provides a carefully controlled environment for the cluster."

On illumination, two water molecules bound at the cluster are split into molecular oxygen and four protons. Since water molecules are very stable, this process requires that the metal cluster be capable of efficiently performing very energetic reactions.

Allen, Williams and coworkers are trying to understand how a primitive anoxygenic organism that was capable of performing only simple low energy reactions could have evolved into oxygen-producing photosynthesis.

They have been manipulating the reaction center of the purple bacterium Rhodobacter sphaeroides encouraging it to acquire the functions of photosystem II. In the recent publication, they describe how a mononuclear manganese bound to the reaction center has gained some of the functional features of the metal cluster of photosystem II.

Read more at Science Daily

Coral Links Ice Sheet Collapse to Ancient 'Mega Flood'

Coral off Tahiti has linked the collapse of massive ice sheets 14,600 years ago to a dramatic and rapid rise in global sea-levels of around 14 metres.

Previous research could not accurately date the sea-level rise but now an Aix-Marseille University-led team, including Oxford University scientists Alex Thomas and Gideon Henderson, has confirmed that the event occurred 14,650-14,310 years ago at the same time as a period of rapid climate change known as the Bølling warming.

The finding will help scientists currently modelling future climate change scenarios to factor in the dynamic behaviour of major ice sheets.

A report of the research is published in this week's Nature.

'It is vital that we look into Earth's geological past to understand rare but high impact events, such as the collapse of giant ice sheets that occurred 14,600 years ago,' said Dr Alex Thomas of Oxford University's Department of Earth Sciences, an author of the paper. 'Our work gives a window onto an extreme event in which deglaciation coincided with a dramatic and rapid rise in global sea levels -- an ancient 'mega flood'. Sea level rose more than ten times more quickly than it is rising now! This is an excellent test bed for climate models: if they can reproduce this extraordinary event, it will improve confidence that they can also predict future change accurately.'

During the Bølling warming high latitudes of the Northern hemisphere warmed as much as 15 degrees Celsius in a few tens of decades. The team has used dating evidence from Tahitian corals to constrain the sea level rise to within a period of 350 years, although the actual rise may well have occurred much more quickly and would have been distributed unevenly around the world's shorelines.

Dr Thomas said: 'The Tahitian coral is important because samples, thousands of years old, can be dated to within plus or minus 30 years. Because Tahiti is an ocean island, far away from major ice sheets, sea-level evidence from its coral reefs gives us close to the 'magic' average of sea levels across the globe, it is also subsiding into the ocean at a steady pace that we can easily adjust for.'

The research is part of a large international consortium, the Integrated Ocean Drilling Program (IODP), and the coral samples were obtained by drilling down to the sea floor from a ship positioned off the coast of Tahiti.

What exactly caused the Bølling warming is a matter of intense debate: a leading theory is that the ocean's circulation changed so that more heat was transported into Northern latitudes.

Read more at Science Daily

Rare Venus Transit of Sun Occurs in June

Mark your calendars! On June 5-6, a rare celestial event called a transit of Venus will take place, and it won't be repeated in your lifetime.

During the transit, Venus will pass directly in front of the sun from Earth's perspective, appearing as a small, slowly moving black dot. The last time this happened was in June 2004, but the next one won’t take place until December 2117. This is the last chance for anyone alive today to see the rare celestial sight.

Unlike a total eclipse of the sun, which is visible only within a long narrow track traced by the moon’s shadow, during the 2012 transit of Venus the entire hemisphere of Earth facing the sun will get to see at least part of the planet’s solar crossing.

The entire transit will be widely visible from eastern Asia, eastern Australia, New Zealand and the western Pacific, as well as Alaska, northern Canada and almost all of Greenland.

For much of North and Central America and northwestern South America, skywatchers will be able to see the start of the transit on the afternoon of June 5. But they'll miss its end, since the sun will have set before Venus exits the the solar disk.

For viewers in central and eastern Europe, western and central Asia, eastern Africa, India and western Australia, the transit will already be under way by the time the sun rises on the morning of June 6 (local time), so they’ll be able to watch the transit’s end from those locations.

WARNING: NEVER look at the sun directly with your naked eye or through cameras, binocularsor small telescopes without proper filters. Doing so can result in permanent eye damage or blindness.

Use a No. 14 welder’s glass filter, or purchase special solar filters from companies such as Thousand Oaks, Kendrick Astro Instruments or Orion Telescopes & Binoculars, and fit them securely over your equipment.

The safest and simplest technique is to observe the transit indirectly using the solar projection method. Use your telescope or one side of your binoculars to project a magnified image of the sun’s disk onto a shaded white piece of cardboard. The projected image on the cardboard will be safe to look at and photograph.

Be sure to cover the telescope’s finder scope and the unused half of the binoculars, and don’t let anyone look through them.

Best viewing locations

Serious skywatchers will want to see the entire transit from start to finish — that is, from the moment Venus’ disk first touches the northeastern edge of the sun to the time the planet completely leaves the west-northwest side of the solar disk, a journey that will take six hours and 40 minutes to complete.

According to eclipse meteorologist Jay Anderson of the Royal Astronomical Society of Canada in Winnipeg, Manitoba, "one country stands out above all others for its good weather during the event: Australia, and only eastern and central Australia at that, as the transit starts just before sunrise in the west. Sydney is fine, but observers in Perth will miss the entry of the planet onto the solar disk."

Anderson said satellite studies suggest that the average cloud cover during the transit will be lowest in Australia's Northern Territory, which should enjoy more than 90 percent of the maximum possible amount of sunshine at that time.

In Southeast Asia and China, the monsoon season will be in its early stages, and cloudiness should therefore be endemic, he added.

"Over Africa, the Middle East and India, good weather prospects stretch from the Sahara across Egypt and Turkey into Iraq and Afghanistan," Anderson said. "For an absolute sure-fire guarantee of a view of at least a part of the transit, it’s hard to beat the statistics for Riyadh in Saudi Arabia — an average cloud amount of 3 percent."

Venus Point, Tahiti

Venus Point in Tahiti, French Polynesia, is also being touted as a prime transit-viewing destination owing to its special historical connection.This site on the island’s northernmost coast was where British captain James Cook observed the transit of Venus in June 1769.

After 243 years, the transit returns once again to Tahiti. On June 6, the planet’s entry, or ingress, into the solar disk can be viewed shortly after local noon. Unfortunately, its exit, or egress, will not be visible since the sun will set about an hour before the transit ends.

Anderson noted that French Polynesia is in its dry season in June and the weather should be cooperative.

"Sunshine averages 67 percent of the maximum at Papeete [Tahiti’s capital], among the better spots in the South Pacific," he said.

United States and Canada

In the United States and Canada, the entire transit can be seen only from Hawaii and Alaska, as well as the Yukon and parts of British Columbia, the Northwest Territories and Nunavut. For the rest of the United States and southern Canada, the sun will set while the transit is still in progress.

In Atlanta and Boston, for example, the transit won't even start until 6:04 p.m. local time; in San Francisco and Seattle, Venus begins crossing the solar disk at 3:06 p.m.

The Hawaiian Islands are a popular transit-viewing destination, with Honolulu on Oahu experiencing 74 percent of possible sunshine in June. From the summit of Mauna Kea on the Big Island, where some of the world’s largest telescopes are located, the transit’s ingress can be seen overhead in the sky, but by the transit’s egress, the sun will be very close to the horizon so low clouds or atmospheric turbulence could pose a challenge for viewers.

Read more at Discovery News

World's Largest Preserve Forming in Africa

Elephants have no respect for lines on a map, especially the artificial national boundaries established by Europeans after carving up Africa into colonial empires. But national boundaries have kept elephants and many other animals cooped up in southern Africa.

The nations of Angola, Botswana, Namibia, Zambia and Zimbabwe agreed to ease some of their own border controls in order to create what will be the world's largest conservation area, reported PRI's Living on Earth. A chunk of land the size of California will include a variety of habitats and allow wildlife to migrate to greener pastures in the dry season and keep their feet dry during the wet season.

Africa's iconic wilflife, elephants, lions, crocodiles, leopards, rhinos, hippos, and buffalo, are expected to bring in tourist dollars. Without the incentive of tourist revenues encouraging conservation, the animals were just a danger and a pest to locals, who had to fear elephants raiding their crops and lions stalking them at night, without the legal right to hunt problem animals.

But legality was rarely a barrier to poachers who decimated herds for meat and luxury items like ivory and rhino horns.

If the animals could escape the poachers bullets, there was still the threat of being blown up by one of the two million landmines peppering Angola after nearly 30 years of civil war. Efforts are underway to remove the deadly devices.

The park may bring both peace and prosperity to the region. As the five nations cooperate with each other and maintain peace internally, the area, which is already a major tourist destination, will likely become even more of a draw. As the people of the region benefit from the living animals, there will be less reason to hunt the beasts.

Read more at Discovery News

Apr 2, 2012

Scientists Find Slow Subsidence of Earth's Crust Beneath the Mississippi Delta

Earth's crust beneath the Mississippi Delta sinks at a much slower rate than what had been assumed.

That's one of the results geoscientists report April 2 in a paper published in the journal Earth and Planetary Science Letters.

The researchers arrived at their conclusions by comparing detailed sea-level reconstructions from different portions of coastal Louisiana.

"The findings demonstrate the value of research on different facets of Earth system dynamics over long time periods," says Thomas Baerwald, geography and spatial sciences program director at the National Science Foundation (NSF).

NSF's Directorates for Geosciences and for Social, Behavioral & Economic Sciences funded the research.

"The results provide valuable new insights about the factors that affect shorelines and other locations in the Gulf Coast area now and into the future," says Baerwald.

"Our study shows that the basement underneath key portions of the Mississippi Delta, including the New Orleans area, has subsided less than one inch per century faster over the past 7,000 years than the more stable area of southwest Louisiana," says paper co-author Torbjörn Törnqvist of Tulane University.

The difference is much lower than previously believed.

"Other studies have assumed that a large portion of the Earth's crust underneath the Mississippi Delta subsided at least 30 times faster due to the weight of rapidly accumulating sediments in the delta," says Törnqvist.

The paper, co-authored by Tulane scientists Shi-Yong Yu and Ping Hu, reveals some good news for residents of the New Orleans area.

Large structures such as coastal defense systems could be relatively stable, provided they are anchored in the basement at a depth of 60-80 feet below the land surface.

Shallower, water-rich deposits subside much more rapidly.

However, the study also provides more sobering news.

"These subsidence rates are small compared to the rate of present-day sea-level rise from the Florida panhandle to east Texas," says Törnqvist.

"The rate of sea-level rise in the 20th century in this region has been five times higher compared to the pre-industrial millennium as a result of human-induced climate change."

Sea level has risen more than eight inches during the past century.

"Looking forward 100 years, our main concern is the continued acceleration of sea-level rise due to global warming, which may amount to as much as three to five feet," says Törnqvist.

Read more at Science Daily

Earliest evidence of man-made fire

Traces of wood ash uncovered next to fragments of animal bones and stone tools in South African caves are the earliest known evidence of human ancestors using fire.

The findings suggest the art of making fire may have begun among species as primitive as Homo erectus, the first early humans to become hunter-gatherers.

The relics were found at the Wonderwerk Cave, a well-known archaeological site near the edge of the Kalahari Desert holding a wide range of evidence of early human occupation.

University of Toronto and Hebrew University of Jerusalem researchers found the traces of ashed plant remnants and charred fragments of bone preserved in million-year-old sediment.

Both the ash and bone appeared to have been burned at the site, rather than be blown into the cave by wind or washed in by water, they reported in the Proceedings of the National Academy of Sciences journal.

Michael Chazan, co-director of the project, said: "The analysis pushes the timing for the human use of fire back by 300,000 years, suggesting that human ancestors as early as Homo erectus may have begun using fire as part of their way of life.

Read more at The Telegraph

Handprints May Give Away Height, Gender

Prints left by the hand, or even parts of it, can be used to estimate the height of an unknown intruder and possibly tell whether they were male or female, say researchers.

A team led by forensic anthropologist Associate Professor Daniel Franklin, from the University of Western Australia, report their findings in a series of recent scientific papers.

"That might be useful if you've got someone who has broken into a house or someone has been seen messing around with a window of a house," says Franklin.

When trying to identify a suspected perpetrator of crime experts try to narrow down the list of potential suspects.

Eyewitness accounts are notoriously unreliable. But Franklin and colleagues, including Nur-Intaniah Ishak from the University of Malaya, in Malaysia, have been investigating the use of hand prints to predict the likely stature and sex of a perpetrator, which they report in a paper published in the journal Forensic Science International.

The researchers took measurements of 91 male and 100 female adults from Western Australia. They measured the height of each individual and took seven measurements of each hand and its corresponding print.

Franklin and colleagues measured hand breadth and length, palm length, as well as the length of the first, second, third and fourth digits.

They then carried out a statistical analysis and found that hand prints involving these parts of the hand could be used to estimate height.

"If you're taller you tend to have longer limbs and you tend to have bigger hands as well. It's a scaling effect," says Franklin.

"We can show that there is a strong correlation between the size of your hand and your ... height and the same thing applies to a print from a hand."

Franklin says a forensic investigator could use these statistics to get a quantifiable estimate of an offender's height and this would help narrow down suspect profiles given out to the public or could be used to narrow down a given list of suspects.

Franklin says the study showed hand prints can predict height with a relatively high degree of accuracy, close to that of height predictions from hand bones.

"The degree of error is close to as good as we can get," he says.

"This is a surprising degree of accuracy and needs to be tested in a larger population."

Franklin says human biological variation means it is impossible for the prediction to be 100 per cent accurate.

But, he adds, it's good enough for narrowing down a potential pool of candidates, who can then have their fingerprints or DNA taken.

"You're not convicting people and it's not going to give you a positive ID but it helps," says Franklin.

"It's an added bonus where there is a hand print at a crime scene."

In a related unpublished paper, Franklin and colleagues used the same hand print size data to predict sex.

"We're not saying that every male is bigger than every female but, on average, in the sample, males were significantly larger than females in terms of their hand dimensions," says Franklin.

The team is also involved in building up a database that will enable forensic investigators to establish the sex, height or age of a victim of crime based on the size of different bones in their skeletal remains.

This can be used to narrow down possible victim identities from a pool of missing persons, for example, before using DNA tests and dental records, which would ultimately used for a positive identification.

Read more at Discovery News

April Fools' Day: The Science of Stupidity

If there's any holiday that comes close to a celebration of the brain, it's April Fools' Day. Neuroscientists dedicate their careers to studying how the mind functions. This field of study covers a variety of questions we might ask about ourselves: How do we form memories? Why do we dream? What is consciousness?

Answering any one of these questions could take a lifetimes of study across a range of disciplines. But given the holiday in which we find ourselves, why not look to science currently out there on this question: What makes us stupid?

Even defining "stupidity" from a neurological standpoint can be difficult. In describing each of the studies below, the term applies to defining a subject who has either exhibited a cognitive decline from a control state, or engaged in risky behavior as a result of improperly evaluating risk. Or both.

Given the health risks associated with consuming a high-fat diet, there's no doubt that regularly eating unhealthy foods isn't a very smart idea. But according to researchers at Oxford University, eating lots of high-fat foods can impair cognitive abilities.

Published in 2009 in FASEB Journal, the study examined the effects of an extended high-fat diet on rats. While being fed a standard, low-fat diet, the rats were tested on their ability to make their way though a maze. This gave researchers a baseline for their short-term memory. Later, the rats ran the same maze after nine days on a high-fat diet and were making more mistakes.

In addition to inhibiting the mental capacities of the test animals, the researchers noted that the diet also affected them physically, making them less able to endure exercise on a treadmill. By the fifth day of the diet, the rats were running 30 percent the distance they were originally. By the ninth day, they were running half as far as they did on the standard diet.

Although teenagers themselves may disagree with the assessment, studies have shown that teens can be impulsive risk-takers. In other words, they are often inclined to act without thinking.

The teen brain is hardwired to overestimate reward and undervalue risk, according to a study published in January 2011 in the Journal of Neuroscience. This lack of impulse control may explain why teens are more vulnerable to drug and alcohol addiction, as well as some psychological disorders, according to the study's authors.

The Internet may contain the largest archive of information in human history. That doesn't mean, however, that we're getting smarter as a result of our near-ubiquitous access to the Web.

While the net effect of the Internet on human intelligence is still the subject of debate, science and technology experts contend that our brains are being rewired as a result of our constant access to information. The Internet essentially serves as an external brain, functioning as a kind of second memory.

Read more at Discovery News

Apr 1, 2012

Organics Probably Formed Easily in Early Solar System

Complex organic compounds, including many important to life on Earth, were readily produced under conditions that likely prevailed in the primordial solar system. Scientists at the University of Chicago and NASA Ames Research Center came to this conclusion after linking computer simulations to laboratory experiments.

Fred Ciesla, assistant professor in geophysical sciences at UChicago, simulated the dynamics of the solar nebula, the cloud of gas and dust from which the sun and the planets formed. Although every dust particle within the nebula behaved differently, they all experienced the conditions needed for organics to form over a simulated million-year period.

"Whenever you make a new planetary system, these kinds of things should go on," said Scott Sandford, a space science researcher at NASA Ames. "This potential to make organics and then dump them on the surfaces of any planet you make is probably a universal process."

Although organic compounds are commonly found in meteorites and cometary samples, their origins presented a mystery. Now Ciesla and Sandford describe how the compounds possibly evolved in the March 29 edition of Science Express. How important a role these compounds may have played in giving rise to the origin of life remains poorly understood, however.

Sandford has devoted many years of laboratory research to the chemical processes that occur when high-energy ultraviolet radiation bombards simple ices like those seen in space. "We've found that a surprisingly rich mixture of organics is made," Sandford said.

These include molecules of biological interest, such as amino acids, nucleobases and amphiphiles, which make up the building blocks of proteins, RNA and DNA, and cellular membranes, respectively. Irradiated ices should have produced these same sorts of molecules during the formation of the solar system, he said.

But a question remained: Could icy grains traveling through the outer edges of the solar nebula, in temperatures as low as minus-405 degrees Fahrenheit (less than 30 Kelvin), become exposed to UV radiation from surrounding stars?

Ciesla's computer simulations reproduced the turbulent environment expected in the protoplanetary disk. This washing machine action mixed the particles throughout the nebula, and sometimes lofted them to high altitudes within the cloud, where they could become irradiated.

"Taking what we think we know about the dynamics of the outer solar nebula, it's really hard for these ice particles not to spend at least part of their time where they're going to be exposed to UV radiation," Ciesla said.

The grains also moved in and out of warmer regions in the nebula. This completes the recipe for making organic compounds: ice, irradiation and warming.

Read more at Science Daily

April Fools! 5 Hilarious Fake Scientific Breakthroughs

  • Science has a sense of humor.
  • Every scientific breakthrough in this article is completely true.
  • Only one of the above statements is true.
Scientists and science journals are at an advantage when it comes to fooling the rest of the world on April 1. For one thing, the average reader is optimistic, and therefore liable to believe anything amazing when it comes to scientific discoveries. Secondly, no one expects a stereotypically dry, robotic scientist to pull a prank.

Here are our favorite fake scientific breakthroughs — tall tales that were really told — from April Fools' Days of the past.

#1 Auspicious Alignments

On the first morning in April 1976, BBC Radio 2 astronomer Patrick Moore announced the approach of a once-in-a-lifetime astronomical event. At 9:47 a.m., Moore said, the planet Pluto the would pass directly behind Jupiter, and at that moment their gravitational alignment would counteract and thus lessen the pull of Earth's gravity. Moore told his listeners that if they jumped in the air at the exact moment of this planetary alignment, they would experience a strange floating sensation. At 9:48, callers flooded the lines of BBC 2 with stories of their brief buoyant experiences.

Last year's flurry of worry about the March 19, 2011 "Supermoon," which people feared would set off earthquakes and other cataclysmic events, showed the public hasn't come very far in its understanding of astronomical influences since the 1976 prank.

#2 Flying Penguins

On April 1, 2008, the BBC played footage of a colony of flying penguins that it claimed had just been discovered on King George Island near Antarctica. In the "mockumentary," former Monty Python star Terry Jones played the David Attenborough-esque guide.

"We'd been watching the penguins and filming them for days, without a hint of what was to come," Jones said. "But then the weather took a turn for the worse. It was quite amazing. Rather than getting together in a huddle to protect themselves from the cold, they did something quite unexpected, that no other penguins can do."

Though penguins can't actually get airborne — not even when Terry Jones is around — the mechanics of how they swim are remarkably similar to how birds fly.

# 3 Telepathic Tweeting

The April 1999 edition of Red Herring Magazine, then a successful tech/business publication, included an article about a revolutionary new technology that allowed users to compose and send email messages of up to 240 characters... telepathically. The article attributed the new development to computer genius Yuri Maldini, who had supposedly created it as a spinoff of the encrypted communications systems he developed for the U.S. Army during the Gulf War. The article even describes an incident when Maldini answered his interviewer's question telepathically, via email. Red Herring received numerous letters from fooled readers.

Telepathic email may not seem as ludicrous now as it did then. Mind-controlled technologies, such as a thought-driven car now under development in Germany, are getting a boost in recent years from revolutionary neuroscience research.

#4 Dragons In Nature

In 1998, the online edition of Nature pulled what may be the most cerebral April Fools' Day prank in history. In an article discussing the debate over the origin of birds, the writer refers to the discovery of "a near-complete skeleton of a theropod [T. rex-like] dinosaur in North Dakota." Dubbed Smaugia volans, paleontologists believe the dino "could have flown."

The skeleton, including rib and neck bones that showed signs of frequent exposure to fire, was supposedly discovered by Randy Sepulchrave of the Museum of the University of Southern North Dakota.

There is no University of Southern North Dakota. That clue-in is straightforward enough, but the other two are more obscure: First, Smaug was the name of the dragon in JRR Tolkien's "The Hobbit."Secondly, Sepulchrave was the 76th Earl of Groan in Mervyn Peake's Titus Groan. The earl believed that he was an owl, and leapt to his death from a high tower. He discovered too late that he could not fly.

#5 Discovering the Bigon

In April 1996, Discover Magazine reported that physicists had discovered a new fundamental particle of matter: the bigon. Like other recent particle finds, the bigon flutters in and out of existence in mere millionths of a second, they explained. But unlike the others, this one is the size of a bowling ball.

Physicist Albert Manque — not a real person — and his colleagues at the Centre de l'Étude des Choses Assez Minuscules in Paris — not a real institute — supposedly found the particle by accident, when a computer connected to one of their vacuum-tube experiments exploded. "The physicists set up a video camera and repeated the experiment — with the same explosive results," Discover journalist Tim Folger wrote. "In one of the video frames a black bowling-ball-size object hovered above the wreckage of the computer. In the next frame it was gone."

Read more at Discovery News