Apr 5, 2014

Baby Volcanic Island Eats Its Older Neighbor

As a seafloor volcano continues to erupt in a remote part of the Pacific Ocean, a newborn island has swallowed its neighbor whole, images from space show.

In November 2013, a baby volcanic island rose from the sea out of a volcanic blast in the Bonin Islands about 620 miles (1,000 kilometers) south of Tokyo, on the western edge of the Pacific "Ring of Fire," a hotbed of seismic activity. Named Niijima, the newcomer boiled the sea and spewed steam, ash and lava fragments into the air.

Some thought the small black cone — which sprouted just offshore of a larger volcanic island called Nishino-shima — might slip back into the sea, vanishing under pounding waves. But Niijima kept growing.

Now a satellite image taken March 30, 2014, by the Operational Land Imager on Landsat 8 shows that Niijima has actually overtaken Nishino-shima.

Together, the conjoined islands measure about 3,280 feet (1,000 meters) across, officials with NASA's Earth Observatory said. The landmass has also tripled in height since December, now rising more than 196 feet (60 m) above sea level.

The smashed-together islands mark the top of a giant submarine volcano that had not erupted since a major outpouring in 1973 to 1974, according to the Japanese Coast Guard. Lava flows are now most active in the southern portion of the new landmass, and plumes of ash continue to rise, with tiny particles seeding a stream of white cloud puffs overhead.

Read more at Discovery News

Light-activated neurons from stem cells restore function to paralyzed muscles

A new way to artificially control muscles using light, with the potential to restore function to muscles paralyzed by conditions such as motor neuron disease and spinal cord injury, has been developed by scientists at UCL and King's College London.

The technique involves transplanting specially-designed motor neurons created from stem cells into injured nerve branches. These motor neurons are designed to react to pulses of blue light, allowing scientists to fine-tune muscle control by adjusting the intensity, duration and frequency of the light pulses.

In the study, published this week in Science, the team demonstrated the method in mice in which the nerves that supply muscles in the hind legs were injured. They showed that the transplanted stem cell-derived motor neurons grew along the injured nerves to connect successfully with the paralyzed muscles, which could then be controlled by pulses of blue light.

"Following the new procedure, we saw previously paralyzed leg muscles start to function," says Professor Linda Greensmith of the MRC Centre for Neuromuscular Diseases at UCL's Institute of Neurology, who co-led the study. "This strategy has significant advantages over existing techniques that use electricity to stimulate nerves, which can be painful and often results in rapid muscle fatigue. Moreover, if the existing motor neurons are lost due to injury or disease, electrical stimulation of nerves is rendered useless as these too are lost."

Muscles are normally controlled by motor neurons, specialized nerve cells within the brain and spinal cord. These neurons relay signals from the brain to muscles to bring about motor functions such as walking, standing and even breathing. However, motor neurons can become damaged in motor neuron disease or following spinal cord injuries, causing permanent loss of muscle function resulting in paralysis

"This new technique represents a means to restore the function of specific muscles following paralysing neurological injuries or disease," explains Professor Greensmith. "Within the next five years or so, we hope to undertake the steps that are necessary to take this ground-breaking approach into human trials, potentially to develop treatments for patients with motor neuron disease, many of whom eventually lose the ability to breathe, as their diaphragm muscles gradually become paralyzed. We eventually hope to use our method to create a sort of optical pacemaker for the diaphragm to keep these patients breathing."

The light-responsive motor neurons that made the technique possible were created from stem cells by Dr Ivo Lieberam of the MRC Centre for Developmental Neurobiology, King's College London.

Read more at Science Daily

Apr 4, 2014

Fermi data tantalize with new clues to dark matter: Gamma rays from center of Milky Way galaxy

A new study of gamma-ray light from the center of our galaxy makes the strongest case to date that some of this emission may arise from dark matter, an unknown substance making up most of the material universe. Using publicly available data from NASA's Fermi Gamma-ray Space Telescope, independent scientists at the Fermi National Accelerator Laboratory (Fermilab), the Harvard-Smithsonian Center for Astrophysics (CfA), the Massachusetts Institute of Technology (MIT) and the University of Chicago have developed new maps showing that the galactic center produces more high-energy gamma rays than can be explained by known sources and that this excess emission is consistent with some forms of dark matter.

"The new maps allow us to analyze the excess and test whether more conventional explanations, such as the presence of undiscovered pulsars or cosmic-ray collisions on gas clouds, can account for it," said Dan Hooper, an astrophysicist at Fermilab in Batavia, Ill., and a lead author of the study. "The signal we find cannot be explained by currently proposed alternatives and is in close agreement with the predictions of very simple dark matter models."

The galactic center teems with gamma-ray sources, from interacting binary systems and isolated pulsars to supernova remnants and particles colliding with interstellar gas. It's also where astronomers expect to find the galaxy's highest density of dark matter, which only affects normal matter and radiation through its gravity. Large amounts of dark matter attract normal matter, forming a foundation upon which visible structures, like galaxies, are built.

No one knows the true nature of dark matter, but WIMPs, or Weakly Interacting Massive Particles, represent a leading class of candidates. Theorists have envisioned a wide range of WIMP types, some of which may either mutually annihilate or produce an intermediate, quickly decaying particle when they collide. Both of these pathways end with the production of gamma rays -- the most energetic form of light -- at energies within the detection range of Fermi's Large Area Telescope (LAT).

When astronomers carefully subtract all known gamma-ray sources from LAT observations of the galactic center, a patch of leftover emission remains. This excess appears most prominent at energies between 1 and 3 billion electron volts (GeV) -- roughly a billion times greater than that of visible light -- and extends outward at least 5,000 light-years from the galactic center.

Hooper and his colleagues conclude that annihilations of dark matter particles with a mass between 31 and 40 GeV provide a remarkable fit for the excess based on its gamma-ray spectrum, its symmetry around the galactic center, and its overall brightness. Writing in a paper submitted to the journal Physical Review D, the researchers say that these features are difficult to reconcile with other explanations proposed so far, although they note that plausible alternatives not requiring dark matter may yet materialize.

"Dark matter in this mass range can be probed by direct detection and by the Large Hadron Collider (LHC), so if this is dark matter, we're already learning about its interactions from the lack of detection so far," said co-author Tracy Slatyer, a theoretical physicist at MIT in Cambridge, Mass. "This is a very exciting signal, and while the case is not yet closed, in the future we might well look back and say this was where we saw dark matter annihilation for the first time."

The researchers caution that it will take multiple sightings -- in other astronomical objects, the LHC or in some of the direct-detection experiments now being conducted around the world -- to validate their dark matter interpretation.

"Our case is very much a process-of-elimination argument. We made a list, scratched off things that didn't work, and ended up with dark matter," said co-author Douglas Finkbeiner, a professor of astronomy and physics at the CfA, also in Cambridge.

"This study is an example of innovative techniques applied to Fermi data by the science community," said Peter Michelson, a professor of physics at Stanford University in California and the LAT principal investigator. "The Fermi LAT Collaboration continues to examine the extraordinarily complex central region of the galaxy, but until this study is complete we can neither confirm nor refute this interesting analysis."

While the great amount of dark matter expected at the galactic center should produce a strong signal, competition from many other gamma-ray sources complicates any case for a detection. But turning the problem on its head provides another way to attack it. Instead of looking at the largest nearby collection of dark matter, look where the signal has fewer challenges.

Dwarf galaxies orbiting the Milky Way lack other types of gamma-ray emitters and contain large amounts of dark matter for their size -- in fact, they're the most dark-matter-dominated sources known. But there's a tradeoff. Because they lie much farther away and contain much less total dark matter than the center of the Milky Way, dwarf galaxies produce a much weaker signal and require many years of observations to establish a secure detection.

Read more at Science Daily

Texas 'Chupacabra' Turns Out to Be Imposter

A Texas couple has captured what is being called a baby chupacabra, the legendary animal said to roam the countryside in search of blood. The "Ratcliffe chupacabra," as it's been dubbed, was found Sunday in a tree on the couple's property in Ratcliffe, Texas. But upon closer examination, it becomes clear that the mysterious creature couldn't possibly be the legendary beast.

The defining feature of the chupacabra is that it's a vampire: Chupacabra means "goat sucker" in Spanish, named so because it is said to drain the blood from animals such as goats, chickens and other livestock.

The news and video footage of the small, hairless, caged animal went viral and left countless people scratching their heads, wondering if a chupacabra (unlike Bigfoot or the Loch Ness Monster) has finally been caught. "In Dewitt County, (Texas), most people are convinced this is the elusive chupacabra," said a reporter with KAVU News, an ABC affiliate based in Victoria, Texas, though a wildlife biologist suggested it might be a dog or coyote. Still, others are not convinced.

So, is this animal the elusive chupacabra? It's clear that it's not, because video of the creature broadcast on KAVU clearly shows the Ratcliffe chupacabra doesn't have the anatomical mouth features that would allow it to suck blood, from goats or anything else.

Like several other "chupacabras" found in Texas and elsewhere in recent years, a simple look at the mouth demonstrates that it is physically impossible for the animals to suck blood. The mouth and jaw structures of raccoons, dogs and coyotes prevent them from creating a seal around their victims, and, therefore, physically prevents them from sucking the blood out of goats or anything else. This Ratcliffe chupacabra was not seen nor videotaped sucking blood from anything.

What is it?

So, if the mysterious animal is not a chupacabra, then what is it?

The most likely answer is that it's a raccoon. Animals that have lost most or all of their hair can be very difficult to identify correctly, for the simple reason that people are not used to seeing the animals without hair.

Wildlife experts often see wild animals suffering from various stages of sarcoptic mange — a skin disease that causes animals' hair to fall out — but most people do not. Healthy raccoons are instantly recognizable by their signature dark "bandit mask" coloring around their eyes. But when their facial hair falls out due to disease, it becomes much more difficult to identify the animal.

Then, you need to look at other features, including size, behavior and anatomy.

These features suggest that the Ratcliffe chupacabra is, indeed, a raccoon. And though most "chupacabras" found in Texas have been identified as canids (the zoological family that includes dogs, coyotes and foxes), this is not the first raccoon misidentified as a chupacabra. In an article in the March/April 2014 issue of "Skeptical Inquirer," another "chupacabra" found and photographed in the 1950s in Texas was identified by Darren Naish, a vertebrate paleontologist and science writer from the University of Southampton, as a mangy raccoon.

Another clue about the animal's origins can be found in where it was discovered: in a tree. This is a typical place to find a raccoon, but unlikely for a dog or coyote. Furthermore, in a video of the animal, the Ratcliffe chupacabra picks up food with its paws to eat. This behavior is also typical of raccoons. The mysterious critter is currently being fed a diet of corn and cat food, but if the creature truly is a chupacabra, that theory can be easily tested: Put it in a pen with a goat or chicken, and see if it attacks them and sucks out its blood.

The reason that the Ratcliffe chupacabra has been called a chupacabra is not that the mysterious animal's characteristics match those of the legendary vampire — because they don't — but instead because those who found it didn't know what else to call it, according to the book "Tracking the Chupacabra: The Vampire Beast in Fact, Fiction, and Folklore" (University of New Mexico Press, 2011).

Read more at Discovery News

Arctic Sea Ice Tops Out at Fifth Lowest on Record

The layer of ice that covers the Arctic Ocean has reached its maximum extent for the year. After several months of expanding over the cold Arctic winter, it has now begun its spring retreat.

According to the National Snow and Ice Data Center (NSIDC), Arctic sea ice reached its seasonal maximum on March 21, after undergoing a brief surge mid-month. It topped out at 14.91 million square kilometers (5.76 million square miles), which is the fifth lowest winter maximum in the satellite record. The lowest maximum yet recorded is 14.63 million square kilometers, or 5.65 million square miles, in 2011.

The loss of Arctic sea ice is a major concern for scientists because it provides essential habitat for species like polar bears and ringed seals and because its disappearance could alter the entire Arctic marine ecosystem by removing essential algae, which forms the basis of the food web.

Ice also reflects sunlight. As it melts, sea ice is replaced by darker ocean, which absorbs that sunlight, creating further warming. And heat rising from a warmer Arctic Ocean may disrupt atmospheric circulation, prompting frigid winters such as that experienced by much of the northern and eastern United States recently.

This year’s figure looked set to be much lower until surface winds helped to spread out the ice pack in the Barents Sea, where ice cover had been anomalously low all winter. Northeasterly winds also helped push the ice pack southward in the Bering Sea, another area where until the ice cover had until then been very low.

Encouragingly, the volume of winter ice increased relative to last year, because of an increase in multiyear ice. One of the reasons scientists speak of Arctic sea ice being in a “death spiral” is that, as the region has warmed and the ice cap has retreated, much of the older, thicker ice that normally survived two or more years has melted, leaving newer, thinner ice that melts more quickly. But the proportion of Arctic sea ice that is multiyear ice increased from 30 percent 12 months ago to 43 percent this year.

Unfortunately, that doesn’t mean less ice will melt this summer. After all, that’s still a smaller percentage of multiyear ice than existed at the start of the melt season in 2007, which concluded with a then-record low minimum extent. And a large area of multiyear ice has drifted to the southern Beaufort Sea and East Siberian Sea, where warm conditions are likely to exist later in the year.

In fact, as NSIDC’s Julienne Stroeve and colleagues point out in a new paper in the journal Geophysical Research Letters, while the medium-to-long-term declining trend is clear, scientists’ ability to make season-to-season, and year-to-year, predictions on sea ice patterns remains low.

Read more at Discovery News

This Eel Fires Extra Alien Jaws Out of Its Throat

That white bit you see emerge from the moray eel’s throat is a second set of jaws that grab the prey and transport it into the bowels of everlasting hell its gullet.
In Alien, which I saw when I was a kid but was too scared to keep my eyes open enough to really watch, people are on a spaceship, then there’s a guy who has, like, tummy problems or something, and finally the big alien enjoys a nice spacewalk. Also, I remember that the alien had a mouth that came out of its regular mouth, and whenever I saw it I had a panic attack.

But I’m older and more sensible now and happy to report that I’m over my fear of jaws that come out of jaws. I know because I can watch the incredible GIF above without suffering a conniption fit. That’s a moray eel, and that white bit you see emerging from its throat? It’s a second set of jaws that fire forward and pull prey down its gullet, just like in Alien … or so people who have seen the whole movie tell me.

This is an apex predator that strikes and grasps unfortunate critters in its regular chompers, then hands the prey off to the nasty hooked teeth of the so-called pharyngeal jaws, which send it down the throat whole. As far as we know, it’s the only fish capable of this remarkable feeding behavior.

Oddly, these jaws are present in all bony fishes, said Rita Mehta, a biologist at the University of California, Santa Cruz. “The vast majority of fishes out there,” she said, “they’re not chewing their food with their oral jaws, and so the evolution of the pharyngeal jaws actually enables them to masticate their food.”

These are the jaws that come out of the moray eel’s throat. The yellowish bits you see are plaque buildups, the result of not enough flossing and waaay too much biting off of dentists’ fingers.
But their jaws have nowhere near the dexterity of those in the 200-odd species of moray eel. (The man who created the Alien queen, by the way, was unfamiliar with the moray. He just set out to create something sufficiently “frightening and horrible,” to which the eels reply, “Uh, rude.”) So why have the morays evolved such an extreme set of chompers?

Most fishes feed using suction, rapidly gaping their maws to create a vacuum that sucks in prey (some frogs and salamanders do this too, including the Surinam toad–whose babies emerge from under its skin–and the 6-foot giant salamanders of Asia). The bigger the head, the bigger the suction.

Moray eels, though, are conspicuously thin, an adaptation to a life spent hiding in crevices waiting for prey, and are therefore unable to generate this vacuum. In addition, they hunt large prey–some morays can reach 10 feet–and swallow them whole. For this, though, suction feeding is inadequate, like a Roomba trying to suck up a tennis shoe.

“Because eating large prey whole means that you need to have a large gape, and gape size is indirectly related to fluid speed, the larger your gape the slower the fluid speed that you’re capable of generating,” said Mehta. “So if you’re going to eat really big, suction is not the way to do it.”

The moray eel with its mortal enemy, the centimeter.
By adapting its pharyngeal jaws into mobilized graspers, the moray doesn’t need a vacuum to get prey to the back of its throat. Instead, it eats like a snake, except without the venom and self-satisfied little tongue flicks. Snakes move their heads over their prey by “ratcheting” the left and right sides of their upper jaws, constantly maintaining a toothy grip. A moray transferring its prey from its regular teeth to the pharyngeal jaws is functionally quite similar. It’s an innovation, according to Mehta, that may have helped morays ascend the throne of the coral reef food chain.

Every ruler has subjects, and the moray is no exception. In 2006, scientists first described a remarkable alliance between morays and groupers, who with a shake of their heads signal to eels that they want to team up for a hunt. (This, of course, is ridiculous. Nodding means “yes” and shaking means “no.” Though it could be that every day is opposite day under the sea.) If the moray accepts, the two stalk side by side in an incredible feat of interspecies cooperation, shown below.

“Essentially, morays or other eels, like snake eels, can go into tight holes in the reefs and capture fish,” said Mehta. “Those fish that get ‘flushed out’ can then be consumed by the predator hunting with the moray, often a grouper. This is an example of how other fishes can ‘exploit’ the elongate body plan of the eel.”



If the grouper catches sight of prey hiding in coral, it will actually signal to the moray with another head shake–the fish equivalent of the pointed finger. And sure enough, the eel investigates, slipping its highly mucoused body into the tightest of crevices in pursuit of its targets while the grouper blocks off escape routes.

The moray will obviously hang on to whatever prey it can get to first, but this cooperative hunting strategy is exceedingly rare in the animal kingdom. Elsewhere, we see dolphins assisting fishermen in Brazil without a speck of training, or honeyguide birds leading us to beehives, then picking up the scraps once we’ve had our fill.

“Oh my God did I leave the oven on?”
But birds and dolphins have long proven their intelligence to humans. Fish, well, we’ve never accused them of being brainy. Except for my pet goldfish Fins, who sometime in the early ‘90s committed suicide by leaping from his tank in what I’m convinced was an act of full-blown civil disobedience. But the moray-grouper alliance suggests intelligence that goes far beyond ritualistic suicide.

There is still much to be learned about the moray, with this behavior and otherwise. Its mating habits and life cycle are particularly mysterious.

“They have this larval stage that’s really peculiar, it’s known as leptocephalus larval stage,” said Mehta. “And in this larval stage, the babies look nothing like a juvenile eel or an adult eel, and essentially they float around in the ocean for about three months.”

Read more at Wired Science

Apr 3, 2014

Super Senses: How Sharks Hunt Down Prey

It turns out that blindfolding a shark or plugging its nose isn't enough to deter it from going after prey. When a shark gets hungry, it will use all the senses it has available to hunt down something to eat, a new study reveals.

The goal of the study was to figure out how sharks use their different senses together, rather than isolating one sense at a time. Researchers examined three species of sharks — blacktip, bonnethead and nurse sharks — in an artificial flow channel inside the Mote Marine Laboratory in Sarasota, Fla.

"The biggest motivation with this multisensory approach was to try to understand what they're really doing in a natural environment with sensory cues," said Jayne Gardiner, a postdoctoral fellow at Mote, who led the study.

She added that researchers have been wanting to do this kind of work for decades, but the sheer amount of data, the size of the facility and the cost required to do this were challenges.

"We were looking at sharks approach food from 8 meters [26 feet] away, and that's not something that most facilities can do. That's one of the great benefits of doing this at Mote Marine," Gardiner said, adding that a large grant from the National Science Foundationhelped knock down the cost.

Disabling the senses

The flow channel constructed in Mote's tank was just big enough to hold a shark on the move, along with a holding pen to contain it while the prey was tethered at the opposite end, upstream. (For nurse sharks and blacktips, the prey was pinfish, and for bonnetheads, it was shrimp.)

Once the shark was released, it would careen down the 7-foot-wide (2 meters) channel toward the prey. The researchers used high-speed cameras to capture the sharks' movements. Each trial was scheduled for 10 minutes, but sometimes, the shark would be out of the gate and eating in less than 10 seconds.

In the first round of this experiment, the researchers let the sharks use all of their senses to capture the prey, to serve as a control for comparison. Then, the researchers blocked each one of the sharks' senses at a time to mark any changes.

To block a nose, they'd use pieces of cotton soaked with petroleum jelly. To block the sharks' vision, the researchers covered the animals' eyes with small pieces of black plastic.

In addition to sight and smell, sharks use their head and body (or lateral line system) to sense water movements, so researchers treated those senses with an antibiotic to destroy the hair cells that make up the receptors. (The cells grow back after a couple of weeks.)

The researchers also used electrically insulating material to cover the electrical connections between the skin and the water, which sharks also use as a sense. (Electrosensory systems are used to find naturally occurring electrical stimuli, and is common among creatures in water since water is a much better conductor than air.)

Building better shark repellant

The sharks were even more adaptable than the researchers had expected. For example, blacktips and bonnetheads found the prey even after their sense of smell was blocked. The nurse sharks did not find the prey, which shows they do rely on their sense of smell in the wild. In captivity, nurse sharks can retrain their systems to rely on visual cues, Gardiner said.

However, human impacts on sharks' environment are affecting the animals' senses, scientists say. For instance, pollutants are hard on the sharks' eyes and noses, and heavy metals and antibiotics can damage the lateral line system.

Read more at Discovery News

How Pterosaurs Ruled the Skies Above the Dinosaurs

NEW YORK — Before birds really took off, the skies of prehistoric Earth belonged to the pterosaurs. These winged reptiles soared around the planet during the time of their relatives, the dinosaurs.

Pterosaurs first appear in the fossil record about 220 million years ago, making them the first vertebrates, or animals with backbones, to evolve the ability to fly on their own power. These creatures also rank as the largest flying animals, ever. Fossils suggest the biggest pterosaur, Quetzalcoatlus northropi, had a wingspan stretching about 33 feet (10 meters), longer than that of a small airplane. Of course, not all were giants. Of the more than 150 known species, some attained birdlike sizes, along the lines of sparrows or seagulls.

With size comes weight. Michael Habib, who studies biomechanics at the University of Southern California, has calculated that one particular group of pterosaurs may have weighed more than 661 pounds (300 kilograms), a weight they managed to consistently foist into the air and keep aloft.

"Flapping flight is one of the more challenging things you can do," Habib said during a panel discussion for a preview of a new pterosaur exhibition here at the American Museum of Natural History. In addition to displaying real pterosaur fossils, including one German specimen known as the Dark Wing, the exhibition includes a motion-sensor-based demonstration where visitors can virtually "pilot" two species of pterosaurs.

Evolving flight


Insects were the first organisms to take to the air using their own power. Among vertebrates, or animals with a backbone, pterosaurs, birds and bats each independently evolved the ability to fly by flapping wings derived from forelimbs. Each of these animals devised different means to accomplish the same lofty feat.

"One of the advantages of the pterosaur body plan in terms of flying animals is you can get bigger," Habib told Live Science. So, not surprisingly, pterosaurs massively outgrew bats and birds. (Among living birds, the wandering albatross has the largest wingspan, measuring up to about 11 feet, or 3.4 m.)

Three anatomical requirements set the stage for large size in flying animals: wing anatomy that generates a large amount of lift per unit speed, hollow bones with a high ratio of stiffness to weight, and the muscle power to launch into the air, Habib said.

"Bats have the right launch system, but they don't have pneumatic [air-filled] bones. Birds have pneumatized bones, but they don't have the right launch system, and they don't have as high a lift coefficient [for their] wings," Habib said. "Pterosaurs are the only ones by happenstance that ended up with those three things."

The flying reptiles could also walk on all fours, and they most likely leaped into the air for takeoff, Habib said.

An exhibition panel at the museum demonstrates how bats, birds and pterosaurs created wings from the same bones humans have in their arms, hands and fingers. But among pterosaurs, a considerable portion of the wingspan comes from a long fourth finger, which corresponds to the human ring finger.

Birds took to the skies during pterosaurs' reign, but they were a little behind the reptiles, said exhibition curator Mark Norell, chair of the museum's paleontology department. Bats, which are mammals, evolved more recently; the earliest known fossil of an insect-eating bat dates back about 50 million years.

Exhibit giants

One of the exhibit's star items provides a rare glimpse of ancient skin. A fossil found in a 150-million-year-old German rock formation contained the preserved tissue of a pterosaur wing, which allowed scientists to detect layers of skin, blood vessels, muscles and the long fibers forming a series of supports within the wing. The color of the wing membrane led researchers to dub the fossil Dark Wing, which has never before been exhibited outside of Germany.

The same formation has yielded about 11 species of Archaeopteryx, a winged animal viewed as a transitional form between predatory dinosaurs and modern birds, Norell said.

Read more at Discovery News

Deadly Dinosaur Chase Reconstructed

A set of prehistoric footprints, said to show meat-eating dinosaurs hunting vegetarian dinos, has just been recreated in a detailed 3-D model.

The frozen-in-time event, dated to at least 112 million years ago, happened at what is now the Paluxy River site in Dinosaur Valley State Park near the town of Glen Rose, Texas — just southwest of Fort Worth.

The chase involved 20 to 30-foot-long predatory dinosaurs going after 30 to 50-foot-long dinosaur prey. While paleontologists aren’t yet certain of the species, Acrocanthosaurus (aka “High-spined Lizard”) is considered the likely hunter and Pleurocoelus (a hefty and impressively huge plant eater) the hunted.

It looks like one or more big predatory dinosaurs was stalking a herd of about 12 sauropods before the hunters went in for the kill. Some have suggested the tracks show one or more dinosaurs dying, since the footprints of young sauropods (the plant eaters) appear to trail off.

The chase scene has been known for some years. Unfortunately, after American paleontologist Roland Bird originally excavated the preserved footprints in 1940, researchers removed the tracks from their original location, divided them into blocks and transported them to various locations around the world.

Bird had documented the original site with photos and maps, but since that excavation, portions of the tracks have been lost. Peter Falkingham of the Royal Veterinary College, along with colleagues James Farlow and Karl Bates, decided to recreate the full set of dinosaur footprints.

“When we first set out to map the Paluxy River track, creating an accurate 3-D model of the site required use of a large, heavy laser scanner that cost tens of thousands of pounds … and was prone to failure especially in the extreme heat in Texas,” Falkingham said in a press release.

They switched to a process called photogrammetry, which uses multiple digital photographs to generate a 3-D model. The process matches features between images and calculates relative camera positions. The researchers were even able to incorporate some of the original photos taken by Bird.

Expect the new process to be applied to other prehistoric sites of interest.

Read more at Discovery News

Saturn's Moon Enceladus Has Underground Ocean

Gravity measurements made with the Saturn-orbiting Cassini spacecraft indicate the small moon Enceladus has an ocean sandwiched between its rocky core and icy shell, a finding that raises the prospects of a niche for life beyond Earth.

The Cassini data shows the body of water, which is in the moon’s southern hemisphere, must be as large or larger than Lake Superior and sitting on top of the moon’s rocky core at a depth of about 31 miles.

"The ocean may extend halfway or more toward the equator in every direction," said planetary scientist David Stevenson, with the California Institute of Technology in Pasadena.

Scientists infer the ocean is salty because water plumes shooting out of cracks in Enceladus’ southern pole and sampled by Cassini contain salts, as well as organic molecules. That would happen if minerals from underlying rock were leaching into water, a chemistry that bodes well for the development and evolution of life.

“It was not a surprise to find a water reservoir certainly, because we knew that there are plumes, there is liquid water,” said planetary scientist Luciano Iess with the Sapienza University of Rome.

“There have been clues all along,” added Candice Hansen-Koharcheck, senior scientist with the Tucson, Ariz.-based Planetary Science Institute.

“But until you actually get this gravity data, it’s still kind of a circumstantial evidence-story. This is proof of the pudding,” Hansen-Koharcheck told Discovery News.

The measurements were painstakingly taken as Cassini flew close to Enceladus three times between 2010 and 2012. Two flybys were over the moon’s south pole, at distances of 65 miles and 44 miles above the surface. One flyby was 31 miles above the North Pole.

During the passes, radio signals were transmitted 850 million miles back to Earth so scientists could ferret out minute shifts in frequency caused by gravitationally tugging on Cassini by the moon, which is about 300 miles in diameter. The slight signals were buried in mountains of other frequency-shifting phenomena, including Earth’s rotation and even the density of the plumes Cassini passed through.

“Tracking the spacecraft to a fraction of a millimeter per second, when you think about it, is truly extraordinary. If only we could do that with Malaysian aircraft,” Stevenson told Discovery News. “

In the end, scientists discovered a notable asymmetry between the moon’s northern and southern hemispheres.

Taking into account what planet- and moon-building materials were available in the outer solar system, scientists agree the gravity measurements point to one thing: a subsurface ocean.

Read more at Discovery News

Apr 2, 2014

Asbestos Lurking Beneath Byzantine Wall Paintings

Hundreds of years before asbestos became ubiquitous in the construction industry, Byzantine monks used the fibrous material in plaster coatings underlying their wall paintings during the late 1100s, new research shows.

Asbestos is a type of natural, rock-forming mineral known for its ability to separate into long, flexible fibers. It has long been thought that asbestos fibers, which are corrosion- and combustion-resistant, were first integrated into such things as plaster, finish coatings and floors after the Industrial Revolution.

But while investigating the 12th-century paintings in the Byzantine monastery Enkleistra of St. Neophytos in Cyprus, UCLA researchers discovered the magnesium silicate mineral, chrysotile (white asbestos), in the finish coating of the plaster underneath a portion of a wall painting. The chrysotile provided a smooth layer with a mirrorlike surface for the painting.

"[The monks] probably wanted to give more shine and different properties to this layer," said UCLA archaeological scientist Ioanna Kakoulli, lead author of the new study, published online last month in the Journal of Archaeological Science. "It definitely wasn't a casual decision — they must have understood the properties of the material."

A long history of use

Though all six asbestos minerals are now known to be carcinogenic, people have taken advantage of the fibrous materials' unique properties for millennia. About 4,500 years ago, artisans mixed asbestos minerals with clay to produce stronger pottery. And 2,000 years ago, asbestos fibers were woven into textiles to make fireproof napkins (that were "washed" by tossing them into fire), or to make a special fabric that could separate human ashes from funeral pyre material during cremations, Kakoulli said. "It was considered to have magical powers," she told Live Science.

In the late 19th century, people used asbestos in industrial products — including cements, wall plasters, joint (drywall) compounds, fire-retardant coatings and roofing, among other things — to increase their durability, insulation and weathering protection.

Given this history, Kakoulli and her colleagues weren't expecting to find asbestos on the walls of Enkleistra of St. Neophytos. They initially set out to see if there was any change in the materials used to create the monastery's numerous wall paintings over time.

"We wanted to see how the technological part of making these paintings follows or reveals anything of what we see in their iconography and style," Kakoulli said.

The researchers analyzed some of the paintings on site using various techniques, including infrared, ultraviolet and X-ray fluorescence imaging. They also collected micro-samples of the paintings and further analyzed their molecular and elemental makeup with powerful scanning electron microscopes and other methods.

A surprising find


One of the paintings they inspected depicted the "Enthroned Christ" holding a book with a red frame. When they analyzed the red frame, they found an asbestos-rich layer that was applied as a finish coating between a red paint layer and a plaster layer made up mostly of plant fibers. "So far, we've only found it in relation to those red pigments," Kakoulli said.

Interestingly, the main deposits of asbestos in Cyprus come from a high-elevation area approximately 38 miles (60 km) from the monastery, which is near the coast. This location suggests the monks may have been involved in a kind of interregional trade for the asbestos.

The discovery raises many questions, such as why the asbestos was used in this context (and only for the red frame in the painting). It's also curious why the fibrous material apparently wasn't used again in coatings until the 19th century.

Read more at Discovery News

Byzantine Monastery and Mosaics Found in Israel

The remains of a 1,500-year-old monastery with intact mosaics covering the floor have been unearthed in southern Israel, the Israel Antiquities Authority announced Tuesday (April 1).

The Byzantine complex — which was discovered near Hura, a Bedouin village in the northern Negev Desert — measures 65 feet by 115 feet (20 by 35 meters). It is arranged on an east-west axis, a common feature in Byzantine churches, and a prayer hall and dining room are decorated with elaborate mosaics that show geometric patterns, leaves, flowers, baskets, jars and birds.

These tiles have managed to retain their vibrant blue, red, yellow and green colors over the centuries. The floor decorations, IAA officials say, include inscriptions in Greek and the Syriac language, which contain rather helpful information for historians: the names of the monastery's abbots — Eliyahu, Nonus, Solomon and Ilrion — and the dates on which each floor was laid down during the second half of the sixth century A.D. [Image Gallery: See a Stunning Byzantine Mosaic]

"It seems that this monastery, located near the Byzantine settlement of Horbat Hur, is one ... in a series of monasteries situated alongside a road that linked Transjordan with the Be'er Sheva Valley," Daniel Varga, who was leading excavations at the site for the IAA, said in a statement.

The monastery also has four service rooms in the western wing, which are paved with white mosaic tiles, IAA officials said. Archaeologists found ceramic jars, cooking pots, kraters, bowls, glass vessels and coins strewn about the ruins.

The discovery was made during a salvage excavation ahead of construction of an interchange on southern Israel's Highway 31. Israeli officials say they plan to relocate the monastery, including its mosaics, to the Wadi 'Attir agricultural and tourism project next to Hura.

Salvage excavations are common in archaeologically rich locales like Israel, where construction and development projects could cover up or damage hidden ruins. Before Israel's Highway 38 could be widened in Eshtaol, archaeologists dug several trenches on the side of the road and discovered a 10,000-year-old house, one of the oldest dwellings in the region.

Read more at Discovery News

Shepherds Spread Grain Along Silk Road 5,000 Years Ago

Nearly 5,000 years ago, nomadic shepherds opened some of the first links between eastern and western Asia. Archaeologists recently discovered domesticated crops from opposite sides of the continent mingled together in ancient herders' campsites found in the rugged grasslands and mountains of central Asia.

“Ancient wheat and broomcorn millet, recovered in nomadic campsites in Kazakhstan, show that prehistoric herders in Central Eurasia had incorporated both regional crops into their economy and rituals nearly 5,000 years ago,” said Micheal Frachetti, archaeologist at Washington University in St. Louis, Mo. and co-author of the study published in the Proceedings of the Royal Society B.

One of the grains found in Kazahkstan, bread wheat (Triticum aestivum), was cultivated in the Middle East by 6,000 years ago, but didn’t show up in East Asian archaeological sites until 4,500 years ago.

Likewise, another grain found in the shepherd’s camps, domesticated broomcorn millet (Panicum miliaceum), may have originated in what is now China 8,000 years ago, but didn’t appear in southwestern Asia until 4,000 years ago.

The nomadic shepherds may have been a crucial link across the vast expanse of steppe, desert and mountains that separated the agricultural and economic systems of eastern and western Asia.

Central Asian shepherds did more than transport grains. The archaeologists also found evidence that herders began farming millet, wheat, barley and legumes by 4,000 years ago. The discovery of this prehistoric agricultural activity in Turkmenistan and Kazakhstan pushed back the earliest know farming in the region by 2,000 years.

Read more at Discovery News

Violent Moon Formation Happened Later Than Thought

Earth’s finishing touch came with a wallop when a Mars-sized hunk of real estate crashed into the fetal planet some 95 million years after the birth of the solar system -- later than some astronomers thought -- sending up debris that eventually formed moon, a new study shows.

The finding, based on 259 computer simulations of asteroid crashes and the resulting buildups of Earth, helps resolve a long-standing debate about when the moon-forming impact occurred.

“Earth was put together piece by piece. It didn’t just appear all at once. And the last piece was probably when something the size of Mars -- about 10 percent of Earth’s mass -- hit Earth,” astrophysicist John Chambers, with the Carnegie Institution for Science in Washington, D.C., told Discovery News.

“Most of that material stayed on Earth, but some of it got blown into space, along with some stuff from Earth, and that then coalesced to form the moon,” Chambers said.

Previous studies used the natural breakdown of telltale radioactive trace materials to estimate how much time passed between the formation of the solar system 4.6 billion years ago and the big splat that launched building blocks for the moon into Earth’s orbit.

But those studies were not conclusive, with some results showing the impact occurring as early as 30 million years after the birth of the solar system.

The new research, which favors a later date, paves the way for scientists to get on with an even meatier question: Why the big discrepancy between Earth’s prolonged formation and the speedy evolution of Mars?

Analysis of Martian meteorites shows the planet formed in just a few million years, a finding supported by the new computer simulations.

That debate is likely to continue until samples are brought back from sister planet Venus, which, like Earth, likely had a long incubation.

“There’s a lot of uncertainty in what (the solar system’s) proto-planetary disk looked like,” lead researcher Seth Jacobson, with the Cote d'Azur Observatory in Nice, France, wrote in an email to Discovery News.

Read more at Discovery News

Apr 1, 2014

Zebra Stripes Not for Camo, But They Do Something Else

Zebra stripes, besides looking very cool, help to ward off biting flies, a new study finds.

The research, published in Nature Communications, negates the popular theory that zebra stripes evolved for camouflage against predators.

How did the camouflage theory originate in the first place then? Many animals do sport fur, skin, feathers and more that match their environments, making them more difficult to find.

Let's face it, though. Zebras stand out like fashion show supermodels against most any background.

Lead author Tim Caro of the University of California at Davis and colleagues, however, do mention that "humans find moving striped objects difficult to target accurately on a computer screen, suggesting a possible motion dazzle confusion effect."

A running zebra might then puzzle predators, but Caro and his team could find no consistent evidence for that after studying all seven existing wild equid species. (This group includes zebras, along with wild horses and wild asses.) Not all of these animals are striped. Przewalski's horse, for example, is usually solid brown in color.

The researchers determined that the distribution of striped species overlaps with the ranges where biting flies are active. Zebras appear to be particularly sensitive to the flies.

"Biting fly mouth part lengths are markedly longer than average hair depths of zebras and approximately the same as zebra hair lengths, perhaps making zebras particularly susceptible to (biting fly) annoyance," the authors wrote.

Flies don't just irritate zebras either. The flies can spread disease and cause significant blood loss.

As for how the stripes ward off biting flies, the researchers explained, "Biting flies are attracted to hosts by odor, temperature, vision and movement that may act at different stages during host seeking, but vision is thought to be important in the landing response."

The flies are attracted to dark colors, but stripes somehow seem to throw off the visual systems of the biting flies.

Read more at Discovery News

Medieval Poop Found: Still Stinks

A number of Medieval wooden barrels have been uncovered in Denmark, revealing their less- than-glamorous contents.

Originally built to transport goods and store fish, the barrels were converted into latrines — still filled with their original contents.

"We are talking about 700-year-old latrines. And yes, they still smell bad," Maria Elisabeth Lauridsen, the archaeologist in charge of the excavation, told Discovery News.

Unearthed in the center of the Medieval town of Odense, the birthplace of the fairy tale writer Hans Christian Andersen, the barrels are believed to have served a toilet area.

"The excavation is characterized by great conditions for preservation and is located on a Medieval site that has been found to contain brick houses, half-timbered houses and stables," Lauridsen said.

Described as being in "excellent condition," the human excrement can give scientists unique insight into what people ate in Denmark in the Middle Ages.

"Preliminary results of analysis show that raspberries were popular in Odense in the 1300s. The contents also contain small pieces of moss, leather and fabric which were used as toilet paper," Lauridsen said.

It appears that barrels were recycled for various use in Medieval Odense. The excavation unearthed three barrels stacked on top of one another and tied together that served as a basic well.

A system of pipes at the bottom of the structure led water to the well. To prevent mud from getting into the well, the lowest barrel was covered with reeds.

"This well has probably been a part of beer brewing. We have excavated nearby a stock of partially germinated barley which is commonly used in the brewing process," Lauridsen said.

Read more at Discovery News

April Fools! 5 Hilarious Fake Scientific Breakthroughs

#1 Auspicious Alignments
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.

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.

A 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 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 less obvious: Smaug was the name of the dragon in JRR Tolkien's “The Hobbit.” And 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.

Read more at Discovery News

Gravitational Wave Discovery Might Not Have Inflation Origin

Last month, astrophysicists announced a groundbreaking discovery: compelling evidence for gravitational waves had been found and the source of these waves might be the inflationary period just after the Big Bang.

Compelling the evidence may be, but could there be another explanation?

In a paper submitted to the arXiv preprint archive last week, a trio of theoretical physicists pushed back on the historic Cosmic Extragalactic Polarization 2 (BICEP2) finding, suggesting that there may be another source of the gravitational waves: What if they weren’t generated during the rapid period of inflation?

First, let’s rewind a little. What is inflation and how are gravitational waves strong evidence of its occurrence?

In a nutshell, when the BICEP2 researchers detected polarized ripples in the cosmic microwave background (CMB) radiation, the signal strongly matched theoretical predictions as to what gravitational waves should look like. Until now, gravitational waves — that Einstein theorized during the formulation of his bedrock theory of general relativity nearly 100 years ago — have been maddeningly difficult to detect. So, at first glance, the BICEP2 finding is a historic one; this is strong observational evidence for gravitational waves, a fact that no scientist is disputing.

But how did these gravitational waves end up being etched into the CMB? This is the point of contention.

The CMB exists right at the very limit of our observational capabilities. Widely regarded as the “echo” of the Big Bang, which occurred nearly 14 billion years ago, we can analyze the very slight temperature fluctuations in the CMB (known as “anisotropies”) to gain an insight to the structure of the Universe just after the Big Bang.

For the Universe to exist in its current scale and for it to have been spawned from a point, however, cosmologists believe the Big Bang had to have been followed by an intense period of acceleration. This faster-than-light expansion occurred a billionth of a billionth of a billionth of a millionth of a second after the Big Bang.

For our current understanding of the Universe to hold true, inflation had to occur. This is where the BICEP2 results comes in.

As interpreted by the BICEP2 team, the gravitational wave polarization signature embedded in the CMB suggests that the gravitational waves themselves have inflationary origin. Gravitational waves are generated by the most energetic events in the Universe — from black holes colliding to stars exploding — like ripples traveling across the surface of a pond, these waves travel through spacetime at the speed of light.

Inflation theory researchers also believe that primordial gravitational waves may be generated during the most violent event our Universe has ever seen: inflation. And the BICEP2 results certainly point to strong evidence of an inflationary (and quantum) origin of these waves.

However, theoretical physicists James B. Dent (University of Louisiana at Lafayette), Lawrence M. Krauss (Arizona State University, Tempe) and Harsh Mathur (Case Western Reserve University, Cleveland, Ohio) think that the BICEP2 researchers may have overlooked an alternate source of these waves.

“While the Inflationary signal remains the best motivated source (of the gravitational wave signal), the current measurement unfortunately still allows for the possibility that a comparable gravitational wave background might result from a self ordering scalar field transition that takes place later at somewhat lower energy,” the physicists write.

So what does this mean?

After the Big Bang, the Universe was a seething chaotic mess of energy. As the Universe cooled, this energy slowly condensed — like raindrops forming from vapor in clouds — to create the fundamental particles and forces we know and love in our modern epoch. Each particle and force came into existence after each successive “phase change” — but these phase changes weren’t created equal and didn’t occur at the same time across the entire Universe; phase changes occurred in localized pockets.

But at a critical point, when the Universe was cool enough, these pockets are thought to have aligned all at once, “snapping” into place.

Although this critical point phase change across the entire Universe was of a lower energy than the inflationary period that came before it, Dent and co. theorize that it would have created a violent ripple that could have spawned the gravitational waves that BICEP2 is now observing in the CMB.

Read more at Discovery News

Mar 31, 2014

Warming climate may spread drying to a third of earth: Heat, not just rainfall, plays into new projections

Increasing heat is expected to extend dry conditions to far more farmland and cities by the end of the century than changes in rainfall alone, says a new study. Much of the concern about future drought under global warming has focused on rainfall projections, but higher evaporation rates may also play an important role as warmer temperatures wring more moisture from the soil, even in some places where rainfall is forecasted to increase, say the researchers.

The study is one of the first to use the latest climate simulations to model the effects of both changing rainfall and evaporation rates on future drought. Published this month in the journal Climate Dynamics, the study estimates that 12 percent of land will be subject to drought by 2100 through rainfall changes alone; but the drying will spread to 30 percent of land if higher evaporation rates from the added energy and humidity in the atmosphere is considered. An increase in evaporative drying means that even regions expected to get more rain, including important wheat, corn and rice belts in the western United States and southeastern China, will be at risk of drought. The study excludes Antarctica.

"We know from basic physics that warmer temperatures will help to dry things out," said the study's lead author, Benjamin Cook, a climate scientist with joint appointments at Columbia University's Lamont-Doherty Earth Observatory and the NASA Goddard Institute for Space Studies. "Even if precipitation changes in the future are uncertain, there are good reasons to be concerned about water resources."

In its latest climate report, the International Panel on Climate Change (IPCC) warns that soil moisture is expected to decline globally and that already dry regions will be at greater risk of agricultural drought. The IPCC also predicts a strong chance of soil moisture drying in the Mediterranean, southwestern United States and southern African regions, consistent with the Climate Dynamics study.

Using two drought metric formulations, the study authors analyze projections of both rainfall and evaporative demand from the collection of climate model simulations completed for the IPCC's 2013 climate report. Both metrics agree that increased evaporative drying will probably tip marginally wet regions at mid-latitudes like the U.S. Great Plains and a swath of southeastern China into aridity. If precipitation were the only consideration, these great agricultural centers would not be considered at risk of drought. The researchers also say that dry zones in Central America, the Amazon and southern Africa will grow larger. In Europe, the summer aridity of Greece, Turkey, Italy and Spain is expected to extend farther north into continental Europe.

"For agriculture, the moisture balance in the soil is what really matters," said study coauthor Jason Smerdon, a climate scientist at Lamont-Doherty. "If rain increases slightly but temperatures also increase, drought is a potential consequence."

Today, while bad weather periodically lowers crop yields in some places, other regions are typically able to compensate to avert food shortages. In the warmer weather of the future, however, crops in multiple regions could wither simultaneously, the authors suggest. "Food-price shocks could become far more common," said study coauthor Richard Seager, a climate scientist at Lamont-Doherty. Large cities, especially in arid regions, will need to carefully manage their water supplies, he added.

Read more at Science Daily

Nanoparticle trapped with laser light temporarily violates second law of thermodynamics

Objects with sizes in the nanometer range, such as the molecular building blocks of living cells or nanotechnological devices, are continuously exposed to random collisions with surrounding molecules. In such fluctuating environments the fundamental laws of thermodynamics that govern our macroscopic world need to be rewritten. An international team of researchers from Barcelona, Zurich and Vienna found that a nanoparticle trapped with laser light temporarily violates the famous second law of thermodynamics, something that is impossible on human time and length scale.

Surprises at the nanoscale

Watching a movie played in reverse often makes us laugh because unexpected and mysterious things seem to happen: glass shards lying on the floor slowly start to move towards each other, magically assemble and suddenly an intact glass jumps on the table where it gently gets to a halt. Or snow starts to from a water puddle in the sun, steadily growing until an entire snowman appears as if molded by an invisible hand. When we see such scenes, we immediately realize that according to our everyday experience something is out of the ordinary. Indeed, there are many processes in nature that can never be reversed. The physical law that captures this behavior is the celebrated second law of thermodynamics, which posits that the entropy of a system -- a measure for the disorder of a system -- never decreases spontaneously, thus favoring disorder (high entropy) over order (low entropy).

However, when we zoom into the microscopic world of atoms and molecules, this law softens up and looses its absolute strictness. Indeed, at the nanoscale the second law can be fleetingly violated. On rare occasions, one may observe events that never happen on the macroscopic scale such as, for example heat transfer from cold to hot which is unheard of in our daily lives. Although on average the second law of thermodynamics remains valid even in nanoscale systems, scientists are intrigued by these rare events and are investigating the meaning of irreversibility at the nanoscale.

Nanoparticles in laser traps

Recently, a team of physicists of the University of Vienna, the Institute of Photonic Sciences in Barcelona and the Swiss Federal Institute of Technology in Z├╝rich succeeded in accurately predicting the likelihood of events transiently violating the second law of thermodynamics. They immediately put the mathematical fluctuation theorem they derived to the test using a tiny glass sphere with a diameter of less than 100 nm levitated in a trap of laser light. Their experimental set-up allowed the research team to capture the nano-sphere and hold it in place, and, furthermore, to measure its position in all three spatial directions with exquisite precision. In the trap, the nano-sphere rattles around due to collisions with surrounding gas molecules.

By a clever manipulation of the laser trap the scientists cooled the nano-sphere below the temperature of the surrounding gas and, thereby, put it into a non-equilibrium state. They then turned off the cooling and watched the particle relaxing to the higher temperature through energy transfer from the gas molecules. The researchers observed that the tiny glass sphere sometimes, although rarely, does not behave as one would expect according to the second law: the nano-sphere effectively releases heat to the hotter surroundings rather than absorbing the heat. The theory derived by the researchers to analyze the experiment confirms the emerging picture on the limitations of the second law on the nanoscale.

Read more at Science Daily

6 New 'Dracula' Ant Species Discovered in Madagascar

Six new species of a mysterious blood-sucking ant have been identified in Madagascar -- and they're an especially odd bunch.

The so-called Dracula ants, described today (March 31) in the journal ZooKeys, seem to defy many of the normal rules that scientists use to classify ants.

"The genus Mystrium is the most mysterious group within the bizarre Dracula ants," study co-author Masashi Yoshimura, a researcher at the California Academy of Sciences, said in a statement. "Mystrium was a difficult group to identify because of the remarkable variation within each species."

The new species include the Mystrium labyrinth, the Mystrium mirror and the Mystrium shadow.

Nonconformists

Dracula ants, so named because they suck the blood of their young in a process dubbed "nondestructive cannibalism," were first discovered in a rotting log in Madagascar more than a decade ago.

But for years, these weird insects confounded researchers, as looks can be deceiving for the Dracula ants.

"The role of an individual in a colony is not always obvious by its appearance. Ants that look similar may be minor workers in one species but queens in another species," study co-author Brian Fisher, an entomologist at the California Academy of Sciences, said in a statement.

For instance, the workers sometimes become queen ants; the queens may have short, nonexistent or large wings; and the queens can often be smaller than the workers. In addition, the genus had three different modes of reproduction, making classification even more difficult.

Mystery solved


After collecting and scrutinizing thousands of the ants in Madagascar for two decades, Yoshimura and Fisher figured out a method for distinguishing new species.

It turned out the ants start out as either a male, a large queen or a major or minor worker, Yoshimura said. Though some of the workers may then go on to reproduce or even become queens, identifying the species requires knowing these origin states, not the current role, of the ant. Classifying them also requires understanding their reproductive style.

Read more at Discovery News

3,300-Year-Old Tomb with Pyramid Entrance Discovered in Egypt

A tomb newly excavated at an ancient cemetery in Egypt would have boasted a pyramid 7 meters (23 feet) high at its entrance, archaeologists say.

The tomb, found at the site of Abydos, dates back around 3,300 years. Within one of its vaulted burial chambers, a team of archaeologists found a finely crafted sandstone sarcophagus, painted red, which was created for a scribe named Horemheb. The sarcophagus has images of several Egyptian gods on it and hieroglyphic inscriptions recording spells from the Book of the Dead that helped one enter the afterlife.

There is no mummy in the sarcophagus, and the tomb was ransacked at least twice in antiquity. Human remains survived the ransacking, however. Archaeologists found disarticulated skeletal remains from three to four men, 10 to 12 women and at least two children in the tomb.

Newly discovered pyramid

The chambers that the archaeologists uncovered would have originally resided beneath the surface, leaving only the steep-sided pyramid visible.

"Originally, all you probably would have seen would have been the pyramid and maybe a little wall around the structure just to enclose everything," said Kevin Cahail, a doctoral student at the University of Pennsylvania, who led excavations at the tomb.

The pyramid itself "probably would have had a small mortuary chapel inside of it that may have held a statue or a stela giving the names and titles of the individuals buried underneath," Cahail told Live Science. Today, all that remains of the pyramid are the thick walls of the tomb entranceway that would have formed the base of the pyramid. The other parts of the pyramid either haven't survived or have not yet been found.

Military ties

It was not uncommon, at this time, for tombs of elite individuals to contain small pyramids, Cahail said. The tomb was excavated in the summer and winter field seasons of 2013 and Cahail will be presenting results at the annual meeting of the American Research Center in Egypt, to be held in Portland, Ore., from April 4-6.

Cahail believes that Horemheb's family had military ties that allowed them to afford such an elaborate tomb. Another burial chamber, this one missing a sarcophagus, contains shabti figurines that were crafted to do the work of the deceased in the afterlife. Writing on the figurines say that they are for the "Overseer of the Stable, Ramesu (also spelled Ramesses)." This appears to be a military title and it’s possible that Ramesu was the father or older brother of Horemheb, Cahail said.

He noted it's interesting that both Horemheb and Ramesu share names with two military leaders, who lived at the same time they did. Both of these leaders would become pharaohs.

"They could actually be emulating their names on these very powerful individuals that eventually became pharaoh, or they could have just been names that were common at the time," Cahail said.

Multiple wives?

The bones the team discovered in the tomb indicate that considerably more women than men were buried in the tomb. This brings up the question of whether Horemheb and Ramesu had multiple wives at the same time. Cahail said that polygamy was a common practice among the pharaohs, but it's uncertain if it was practiced among non-royalty.

Another possibility is that the tomb was used for multiple generations by the same family and contains the remains of daughters, mothers and other female relatives. Yet another possibility is that the tomb was re-used, without permission, at a later date.

Radiocarbon tests, which can provide a date range for the bones, may be done in the future to help solve the mystery.

"You’re left with the question, who are all these people?" Cahail said.

A Jasper treasure

One of the most interesting artifacts the team found was a heart amulet, made of red and green jasper. The hard stone amulet was broken into three pieces.

"It's a beautiful object and possibly one of the best carved examples of these very rare type of amulets," Cahail said. "It was probably on the chest of one of the deceased individuals and there probably would have been some sort of necklaces and gold and things like that."

Read more at Discovery News

Mar 30, 2014

Transparent Armor Inspired by Oyster Shell

Two new scientific papers in the last week describe ways to make new kinds of armor that take inspiration from humble mollusks: the abalone and the windowpane oyster. Researchers for both teams, one from France the other from MIT, say they don’t think it will be long before soldiers, and perhaps our cars, will be outfitted bio-inspired armor, windshields or heat shields.

“There is so much going on right now, the advances in the next decade are going to be incredible,” said Christine Ortiz, professor of materials science and engineering at MIT. Ortiz and graduate student Ling Li have a study in today’s edition of the journal Natural Materials describing experiments with a species of oyster (Placuna placenta) that has a shell that is 99 percent ceramic and 80 percent transparent. That’s a pretty good combination for a bullet-proof windshield, explained Ortiz.

“When we started doing mechanical tests we found it has multi-hit capability,” Ortiz said. And, unlike glass, when the researchers penetrated the oyster shell with a tiny sharp object, the shell didn’t fracture and the deformation was localized.

Obviously, an 80 percent clear windshield isn’t good enough to see through. But that’s because the windowpane oyster doesn’t need to be transparent, just blend in with the sandy sea bottom. The next step is to replicate the structure of the oyster shell with another material.

“How do you make a nano-composite in the structure with an anti-ballistic ceramic?” Ortiz said.

At the French National Center for Scientific Research (CNRS/Saint-Gobain), Sylvain Deville has come up with a unique method of using the substance secreted on the insides of shells called mother-of-pearl, or nacre, for another kind of bio-inspired armor. Deville’s work was published March 23 in the same journal, Nature Materials, and uses the structure of ice crystals as a template for building the armor.

“For armor, nacre is the real standout for everyone,” Deville said from his lab in Cavaillon, France. “It’s so good for absorbing energy.”

Read more at Discovery News

Seeds of Monster Black Holes Were Surprisingly Big

The gigantic black holes that lurk at the hearts of galaxies were apparently born big.

The central black holes in dwarf galaxies — the "seeds" that grow into the monsters at the core of the Milky Way and other large galaxies — are probably surprisingly weighty, containing 1,000 to 10,000 times the mass of our sun, a new study reports.

The finding goes against one popular theory of supermassive black hole evolution, suggesting that galaxy mergers aren't necessary to create these behemoths, which can harbor billions of times more mass than the sun.

"We still don't know how the monstrous black holes that reside in galaxy centers formed," lead author Shobita Satyapal, of George Mason University in Virginia, said in a statement. "But finding big black holes in tiny galaxies shows us that big black holes must somehow have been created in the early universe, before galaxies collided with other galaxies."

It's also possible that supermassive black holes grow primarily by gobbling up gas and dust, getting bigger relatively sedately along with their host galaxies, researchers said.

Satyapal and her colleagues analyzed observations of dwarf galaxies made by NASA's Wide-field Infrared Survey Explorer spacecraft, or WISE.

Dwarf galaxies have changed relatively little over time, and they resemble the types of galaxies that existed when the universe was young. So they're a good place to look for nascent supermassive black holes, researchers said.

WISE's all-sky survey picked out hundreds of dwarf galaxies, which appear to sport strikingly large black holes.

"Our findings suggest the original seeds of supermassive black holes are quite massive themselves," Satyapal said.

While the results are intriguing, follow-up study will be necessary to fully flesh them out, outside researchers said.

"Though it will take more research to confirm whether the dwarf galaxies are indeed dominated by actively feeding black holes, this is exactly what WISE was designed to do: find interesting objects that stand out from the pack," astronomer Daniel Stern, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. Stern was not part of the study team.

Read more at Discovery News