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

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

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