Jun 13, 2015

First room-temperature magnetic skyrmion bubbles

New ideas are bubbling up for more efficient computer memory.

Researchers at UCLA and the U.S. Department of Energy’s Argonne National Laboratory announced today a new method for creating magnetic skyrmion bubbles at room temperature. The bubbles, a physics phenomenon thought to be an option for more energy-efficient and compact electronics, can be created with simple equipment and common materials.

Skyrmions, discovered just a few years ago, are tiny islands of magnetism that form in certain materials. If you wrapped one up into a sphere, its magnetic fields would point away in all different directions—so they stay in neat little packages and don’t unravel easily.

Scientists found they could prod these skyrmions to move using electric currents, and an idea was born: could we use them to represent 1s and 0s in computer memory?

Transistors, which form the basis of today’s computing, are tiny devices that stop the flow of electric current (off and on, 1 and 0). But there’s a limit to how small we can make them, and we’re running up against it. Scientists want to find a way to create 1 and 0 by using physics phenomena that don’t actually change the atomic structure of the material—for example, making a line of skyrmions that could be read as 1s (skyrmion) and 0s (no skyrmion).

But the only way we knew how to make new individual skyrmion bubbles on demand was at very, very low temperatures (below -450 degrees Fahrenheit) with expensive equipment like spin-polarized scanning tunneling microscopes—not practical for making consumer devices like laptops, and not even easy for most scientists to make so they could study them.

“Our new method is the simplest way to generate skyrmion bubbles thus far,” said Argonne postdoctoral researcher Wanjun Jiang, the first author on the study.

The team used a geometric structure to “blow” the bubbles into shape in a very thin film. Using the Center for Nanoscale Materials, a DOE Office of Science user facility at Argonne, they built a constricted wire out of a three-layered structure in which a tiny layer of magnetic material is sandwiched between tantalum and tantalum-oxide layers.

Long stripes of magnetic domains appear in the magnetic material on one side of a tiny channel. When the scientists applied an electric current to the metal layers, the stripes stretched through the channel and broke into tiny spherical skyrmion bubbles on the other side—much like how children blow soap bubbles.

By running a smaller electric current through the system, they could make the skyrmions move.

“These aren’t exotic materials—they’re widely used already in the magnetics industry,” said Argonne materials scientist Axel Hoffmann, the corresponding author on the paper. The electric current needed to move the skyrmions is much lower than what’s used in other experimental memory alternatives, like racetrack memory, he said.

“With this system we can explore many of the theoretical ideas on skyrmion physics that have been proposed over the past few years,” said Argonne physicist Suzanne G.E. te Velthuis, who co-authored the study.

Read more at Science Daily

Longstanding biology problem put to rest

Comparing the genomes of different species -- or different members of the same species -- is the basis of a great deal of modern biology. DNA sequences that are conserved across species are likely to be functionally important, while variations between members of the same species can indicate different susceptibilities to disease.

The basic algorithm for determining how much two sequences of symbols have in common -- the "edit distance" between them -- is now more than 40 years old. And for more than 40 years, computer science researchers have been trying to improve upon it, without much success.

At the ACM Symposium on Theory of Computing (STOC) next week, MIT researchers will report that, in all likelihood, that's because the algorithm is as good as it gets. If a widely held assumption about computational complexity is correct, then the problem of measuring the difference between two genomes -- or texts, or speech samples, or anything else that can be represented as a string of symbols -- can't be solved more efficiently.

In a sense, that's disappointing, since a computer running the existing algorithm would take 1,000 years to exhaustively compare two human genomes. But it also means that computer scientists can stop agonizing about whether they can do better.

"This edit distance is something that I've been trying to get better algorithms for since I was a graduate student, in the mid-'90s," says Piotr Indyk, a professor of computer science and engineering at MIT and a co-author of the STOC paper. "I certainly spent lots of late nights on that -- without any progress whatsoever. So at least now there's a feeling of closure. The problem can be put to sleep."

Moreover, Indyk says, even though the paper hasn't officially been presented yet, it's already spawned two follow-up papers, which apply its approach to related problems. "There is a technical aspect of this paper, a certain gadget construction, that turns out to be very useful for other purposes as well," Indyk says.

Squaring off

Edit distance is the minimum number of edits -- deletions, insertions, and substitutions -- required to turn one string into another. The standard algorithm for determining edit distance, known as the Wagner-Fischer algorithm, assigns each symbol of one string to a column in a giant grid and each symbol of the other string to a row. Then, starting in the upper left-hand corner and flooding diagonally across the grid, it fills in each square with the number of edits required to turn the string ending with the corresponding column into the string ending with the corresponding row.

Computer scientists measure algorithmic efficiency as computation time relative to the number of elements the algorithm manipulates. Since the Wagner-Fischer algorithm has to fill in every square of its grid, its running time is proportional to the product of the lengths of the two strings it's considering. Double the lengths of the strings, and the running time quadruples. In computer parlance, the algorithm runs in quadratic time.

That may not sound terribly efficient, but quadratic time is much better than exponential time, which means that running time is proportional to 2N, where N is the number of elements the algorithm manipulates. If on some machine a quadratic-time algorithm took, say, a hundredth of a second to process 100 elements, an exponential-time algorithm would take about 100 quintillion years.

Theoretical computer science is particularly concerned with a class of problems known as NP-complete. Most researchers believe that NP-complete problems take exponential time to solve, but no one's been able to prove it. In their STOC paper, Indyk and his student Art?rs Bačkurs demonstrate that if it's possible to solve the edit-distance problem in less-than-quadratic time, then it's possible to solve an NP-complete problem in less-than-exponential time. Most researchers in the computational-complexity community will take that as strong evidence that no subquadratic solution to the edit-distance problem exists.

Can't get no satisfaction

The core NP-complete problem is known as the "satisfiability problem": Given a host of logical constraints, is it possible to satisfy them all? For instance, say you're throwing a dinner party, and you're trying to decide whom to invite. You may face a number of constraints: Either Alice or Bob will have to stay home with the kids, so they can't both come; if you invite Cindy and Dave, you'll have to invite the rest of the book club, or they'll know they were excluded; Ellen will bring either her husband, Fred, or her lover, George, but not both; and so on. Is there an invitation list that meets all those constraints?

In Indyk and Bačkurs' proof, they propose that, faced with a satisfiability problem, you split the variables into two groups of roughly equivalent size: Alice, Bob, and Cindy go into one, but Walt, Yvonne, and Zack go into the other. Then, for each group, you solve for all the pertinent constraints. This could be a massively complex calculation, but not nearly as complex as solving for the group as a whole. If, for instance, Alice has a restraining order out on Zack, it doesn't matter, because they fall in separate subgroups: It's a constraint that doesn't have to be met.

Read more at Science Daily

Jun 12, 2015

Polar Bears Develop Taste for Dolphins as Arctic Warms

Norwegian scientists have seen polar bears eating dolphins in the Arctic for the first time ever and blame global warming for the bears expanding their diet.

Polar bears feed mainly on seals but Jon Aars at the Norwegian Polar Institute has photographed dolphins being devoured by a bear and published his findings in the latest edition of Polar Research this month.

“It is likely that new species are appearing in the diet of polar bears due to climate change because new species are finding their way north,” he told AFP.

The first incident he documented was in April 2014 when his team came across a polar feeding on the carcasses of two white-beaked dolphins.

Although dolphins are regularly seen in the Norwegian Arctic in the summer months when the ice has melted, they have never been observed during winter or spring when the sea is usually still covered in sheets of ice.

But Norwegian scientists have reported a strong retreat of ice and two nearly ice-free winters in recent years which they said could have attracted the dolphins further north, where they probably became trapped by the sudden arrival of dense ice blown into a fjord by strong northerly winds.

Aars said the bear he photographed had probably caught the two dolphins when they surfaced to breathe through a tiny hole in the ice.

“Even if they saw the bear, the dolphins did not necessarily have any other choice,” he said.

Saved one for later

In the photos, a visibly-skinny old male bear devours one of the dolphins and appeared to have stored a second one under snow for later -- something scientist had never seen before.

"We think that he tried to cover the dolphin in snow in the hope that other bears, foxes or birds would have less of a chance of finding it. Maybe to be able to eat it a day or two later, once he had digested the first one," said Aars.

After the first incident in 2014, a further five cases of dolphins stranded or captured and then eaten by bears have been reported.

"I don't think that this signifies a great upheaval" in the diet of the carnivores, said Aars.

"It's just that the polar bear is coming into contact with species they have not been used to meeting until now."

Read more at Discovery News

Penis Disorder Found in Fertility God Pompeii Portrait

One of Pompeii's most recognized frescoes, the portrait of the Greek god of fertility Priapus, holds an embarrassing truth, according to a new study of the 1st-century A.D. wall painting.

Found in the entrance hall to the House of the Vettii, perhaps the most famous house to survive Mount Vesuvius's devastating eruption, the fresco shows the ever-erect Priapus with his engorged penis.

But this phallus-flaunting symbol of male potency and procreative power shows signs of a condition which can result in difficult sexual relations and infertility, says a study published in Urology journal.

"The disproportionate virile member is distinctively characterized by a patent phimosis, more specifically a shut phimosis," Francesco Maria Galassi told Discovery News.

Galassi is an M.D. now back in Italy who recently worked at Imperial College London. He co-authored the paper with his father Stefano, also an M.D.

An inability to fully retract the foreskin, phimosis was treated only with circumcision or prepuceplasty before the introduction of topical corticosteroids.

"This condition presents different grades of severity, and in this specific case appears to be of the highest grade, in which there is no skin retractability on the glans," Galassi said.

Defects of the genitourinary tract, including phimosis, have been depicted in artistic representation since prehistory, showing a high degree of precision.

But why someone would portray the god of fertility with a severe phimosis?

"It is not unlikely the painter might have desired to report objective evidence of a high prevalence of that anatomic defect in Pompeii, at a time mixing it with fertility attributes traditionally ascribed to Priapus," Galassi said.

In this view, widespread among the male population in Pompeii, phimosis might have been the reason for the abundance in Pompeii of anatomical votive artifacts used to dispel that anatomical and functional defect.

"Anatomical votive offerings made in Italy between the fourth to second centuries B.C. do often show the penis with the foreskin closed around the top, as in the later Priapus painting from Pompeii," Jessica Hughes, lecturer in classical studies at UK’s Open University, told Discovery News.

Read more at Discovery News

Bones in Alexander the Great Tomb Give Up Few Secrets

It’s a mystery worthy of Sherlock Holmes, with a backstory that puts “Game of Thrones” to shame: Who was laid to rest in a lavish, gold-filled Macedonian tomb near Vergina, Greece? The tomb, discovered in 1977, might be the final resting place of Philip II of Macedon, conqueror of Greece and father of Alexander the Great, who would push his father’s empire to the edge of India.

Or, it might be the grave of the distinctly less impressive Philip III Arrhidaios (also written as Arrhidaeus), the half brother of, and figurehead successor to, Alexander the Great.

The latest volley in the debate over which Philip occupies the tomb makes a case for the illustrious Philip II, arguing that the woman found interred alongside the much-debated male body was too old to have been the younger Philip’s wife. But this new research seems unlikely to resolve the great Macedonian tomb mystery.

A complicated history

Archaeologists discovered the contentious tomb in 1977. Amid paintings and pottery was a gold sarcophagus containing a man’s cremated bones. Nearby were the even-more-fragmentary burned bones of a woman.

The tomb’s discoverers declared the man was Philip II, who took the throne of Macedonia in 359 B.C. as regent for his infant nephew. Displaying the kind of initiative that defined the Macedonian royal family, Philip II quickly took the throne for himself and started conquering his neighbors.

This went well until 336 B.C., when one of Philip II’s bodyguards assassinated him as he walked into a theater in the Macedonian capital of Aegae. It’s not entirely clear why the king was murdered; ancient historians told various tales, including one in which the murderer was a former male lover of Philip who had hounded another of Philip’s male lovers to suicide and then was himself subjected to sexual assault by one of Philip’s in-laws as revenge for that suicide. Some argued that Philip’s fourth wife, Olympias, who was rumored by the historian Plutarch to sleep with snakes, had something to do with it.

Regardless of whether Olympias was that diabolical, she certainly knew how to play politics — with bloody results. The queen moved quickly to put her own son, Alexander, on the throne. She arranged for Philip’s two children by another wife, Cleopatra Eurydice, to be killed; Cleopatra Eurydice committed suicide by force soon after. Archaeologists who argue that the tomb at Vergina contains Philip II’s bones have argued that the female remains found in the tomb belong to Cleopatra Eurydice.

But not everyone believed the bones matched those of Philip II. In 1981, a further examination of the remains led to claims that the body instead belonged to Philip III Arrhidaios. After Alexander the Great died in 323 B.C. (under mysterious circumstances, naturally), Philip III Arrhidaios took the throne as a figurehead, with his niece and wife Eurydice (not the same person as his father’s seventh wife) as queen. Ancient historians described Philip III Arrhidaios as mentally unfit. Plutarch blamed Olympias for the mental issues, claiming she’d tried to poison Arrhidaios as a child, but Plutarch clearly was not Olympias’ biggest fan, and modern historians are skeptical.

Eurydice, however, was a force to be reckoned with. Her attempts to grab real power put her on a collision course with Olympias and her allies. In 317 B.C., during a war over secession, Olympias’ forces defeated the king and queen — Philip III Arrhidaios and Eurydice. He was executed, and she was forced to commit suicide. As if that weren’t enough indignity, their bodies were dug up more than a year later and cremated for a royal funeral meant to shore up legitimacy for the next king.

Archaeological arguments

Much of the debate around whether the tomb belongs to Philip II or Philip III Arrhidaios has focused on the burned bones. In the 1980s, Jonathan Musgrave, an anatomist at the University of Bristol in the United Kingdom, created a facial reconstruction of the skull and argued that a notch in the bone over one eye matched historical descriptions of one of Philip II’s battle wounds. In 2000, Greek paleoanthropologist Antonis Bartsiokas published a paper in the journal Science arguing that the bone notch and other features Musgrave had highlighted were simply incidental to cremation. (Musgrave does not agree.)

Another line of debate questions whether the bones show signs of warping, which occurs when flesh-covered bodies are cremated. If the bones of Philip III Arrhidaios were dug up and cremated months after the king’s death, they might show less warping, or at least a different warping pattern compared with what would be found if the bones were cremated immediately.

Much of this argument falls by the wayside in the new paper, recently accepted for publication by the International Journal of Osteoarchaeology. The researchers, led by Theodore Antikas of Aristotle University in Greece, conducted a five-year forensic study of the bones, including computed tomography (CT) scans.

The researchers argue that the bones of the man and the woman were, in fact, cremated with the flesh still on; however, because Philip III Arrhidaios was not in the ground long enough to become completely skeletal before exhumation, this does little to distinguish the two men.

The new study likewise fails to find any evidence of an eye wound in the male skull, though the researchers did find a healing wound in the hand that might match one of Philip II’s battle injuries. The male body also had growths called Schmorl’s nodes on his lower vertebrae, a telltale sign of bone stress from horseback riding.

With no smoking guns to identify the male skeleton, the team turned to the female bones. Here, they argue, was a 30- to 34-year-old woman, also a horseback rider, who had a fractured leg bone that would have caused her left leg to be shorter than her right. Tellingly, a set of leg armor, or greaves, found in the tomb appears to be made to fit someone with a shortened left leg, Antikas wrote.

This suggests the tomb artifacts, including a quiver holding 74 arrowheads, belonged to the woman buried in the tomb, pointing to her identity as a Scythian princess married to Philip II in 339 B.C. Scythia was a kingdom comprising what is now Central Asia and parts of Eastern Europe.

“The gorytus, arrowheads, spears and everything in the antechamber belong to a Scythian warrior woman and NOT to Philip or any other woman but the seventh wife/concubine, namely the daughter of King Ateas,” Antikas wrote in an email to Live Science. (A gorytus is a case for bows and arrows.) Antikas declined to comment on other aspects of the study. If he’s right, however, the woman in the tomb is not the Macedonian Cleopatra Eurydice, but another, foreign bride of Philip II’s.

Bone backlash

But the move toward identifying the tomb’s occupants based on the female skeleton rather than the male one brings its own controversy.

“Frankly, I am disappointed that the International Journal of Osteoarchaeology has published this article,” said Maria Liston, an anthropologist at the University of Waterloo in Ontario who studies cremated remains in Greece. “I don’t think it makes a substantive contribution to this debate, and it certainly does not refute the position of those who say the skeleton is not Philip II.”

Among the problems with the new research, Liston said, is an overconfident approach to aging the skeletons. The researchers looked at the pubic symphysis, the cartilage-padded joint of the pubic bone, to peg the woman’s age at between 30 and 34 years. But the method they used can’t possibly determine age to that level of precision, Liston said. Rather, it can pinpoint the woman’s age only to between 21 and 53 years old, she said.

The researchers also found that the sternal end of the clavicle, the end near the breastbone, was fused. But that fusion blows their case out of the water, Liston said, because the bones begin to fuse by 19 or 20 years old and are usually done fusing within a few years, and are always fused entirely by age 29.

“It can’t be the age they’re saying,” Liston told Live Science. If the woman was younger than 29, as the clavicle fusion suggests, she could well be Philip III Arrhidaios’ wife Eurydice, who was only about 20 when she died.

Even the broken leg doesn’t seal the case, Liston said. She’s not convinced the asymmetrical greaves are made for someone with legs of two different lengths — one may simply have a lengthened flange that flared over the ankle, providing the leading leg with an extra bit of protection. Thus, the greaves may not belong to the woman in the tomb at all.

Other archaeologists contacted by Live Science declined to comment, citing the preliminary nature of the paper (the journal has not yet released a final version of the publication) or unfamiliarity with the burial context.

The tombs at Vergina are an important cultural and tourist site in Greece and a UNESCO World Heritage Site, which raises the stakes of what would otherwise be a largely academic debate. The museum at Aigai, which oversees the tombs, refers to the tomb as Philip II’s without caveat, as does UNESCO. But among archaeologists, nothing is settled.

Read more at Discovery News

Has Rosetta's Lost Philae Lander Been Found?

After all the excitement of the dramatic bouncy landing on Comet 67P/Churyumov-Gerasimenko, the little Philae lander was able to take a quick look around its surroundings and even do some science before it shut down, running out of battery power.

But where did the lander end up? Philae’s final landing spot was far from ideal, having skipped across the dusty surface and settled next to a shady overhang. Without sunlight to recharge its batteries, the lander fell silent. There are still hopes, however, that Philae may reawaken as the comet’s orientation changes to allow more sunlight to fall on its solar array.

To make matters perplexing, Philae’s final resting place was not known and for months European Space Agency scientists have been studying high-resolution imagery of 67P’s terrain in the hope of picking out the tiny lander. Since December, the orbiter has not been able to make a close enough pass of the comet’s surface as cometary activity has been high — the jets of gas and dust have become a hazard for Rosetta’s navigation systems.

In a new analysis, however, mission scientists think they may have found Philae in the frigid terrain, a bright patch glinting in sunlight that is being described as “a good candidate for the lander.”

From Discovery News

The Lowly Clam That Almost Sank Two of Columbus’ Boats

If your boat looks like this, you're up shit creek without a paddle, so...hopefully that thing has an engine?
It was the year 1731, and the Dutch economy was at the mercy of a clam. But not just any clam, mind you—give the Dutch some credit. This was a true oddity, or at the very least an eccentric. While your typical clam lives a life of security in its shell, the so-called shipworm has a tiny calciferous casing, from which erupts a skinny tube of flesh up to two feet long. Swarms of the things burrow into wood, be it ship hulls or piers or, unfortunately for the Dutch, wooden dikes.

The strange invertebrate had destroyed over 30 miles of Dutch dikes, and threatened another dozen miles. The Netherlands were in serious danger of flooding, and the economy was spooked. Peasants fled their farms and entered the cities, where they could find no jobs. Crews tried switching the wood out for tropical hardwood, to no effect. The only solution was to import stones and build dikes that way, at no small taxpayer expense.

It wasn’t the first time the shipworm had menaced humans, and it wouldn’t be the last. The things had already terrorized the ancient Greek and Roman navies, and ate away so badly at two of Columbus’ ships on his fourth voyage to the Caribbean that he had to abandon the vessels. Later on in the 1910s, a shipworm infestation hit the docks of San Francisco Bay, causing what would today be billions of dollars in damages.

But have shipworms ever actually sunk a boat out at sea? “More or less,” laughs molecular ecologist Luísa Borges of Germany’s Helmholtz Center for Material and Coastal Research. “If you believe in the historical reports, apparently they sunk quite a lot of ships, when they undertook these long voyages.” The loss of several vessels in the Spanish Armada, for instance, have been blamed on shipworms, which the Brits no doubt appreciated.

Barking Up the Wrong Tree

The first question to ask here isn’t how the shipworm manages to bore into wood—and in such numbers that it can threaten national economies, for that matter—but how the hell a marine creature could evolve to rely on a terrestrial material in the first place. Shipworms subsisting on trees that happen to wash out to sea is a bit like you trying to survive solely on dead things that wash ashore.

Shipworms are tireless advocates of recycling—as long as the material is wood, and they’re eating it. They’re somewhat meh about plastic.
But there are marine habitats where plenty of wood grows right in the saltwater: mangrove forests. Mangrove trees are incredible survivors. Saltwater would kill any other kind of tree, but the mangrove’s roots can filter out the salt, and some species have roots that grow vertically up out of the water to take in more oxygen. It was among these trees that the first shipworms likely evolved. But now, thanks to the global economy, the clams have hitched rides to coastal cities all over the world.

The shipworm’s life cycle begins as a larva that settles onto wood, be it a mangrove root or pier or ship. While the adult clam’s shell covers only a tiny fraction of its body, the larva looks like a regular bivalve. It begins drilling a tiny hole into the wood, either by releasing enzymes to break down the tissue or by rasping away with its shell, or a combination of the two methods. “So it’s mechanical, most of it,” says Borges. “But some people think there might be some enzymatic action there too. It’s not entirely known.”

“The animal has a very strong foot,” she adds, “as most bivalves and gastropods and so on have. And it uses it like a suck, and moves the shell sideways and uses it as a rasp and file device.”

Now, if you’re anything like me, you’ve gone your whole life without ever licking a two-by-four. But it’s safe to say that mucousy flesh does not get along well with the abrasiveness of wood, so this leaves the shipworm with a problem: As it grows and elongates and continues to bore deeper into the wood, the shipworm risks stripping its own delicate flesh away. To avoid this, it excretes a calcareous lining—the same calcium carbonate material that makes up its shell—along its worm-like body. Pull a shipworm out of some wood and it’ll leave the calcareous tube behind.

The business end of a shipworm. And business is booming.
Gut Instincts

Now, if you’re anything like me, you’ve also gone your whole life without eating mangrove trees. It’s safe to say that they’re indigestible for humans, but not for the shipworm. It can digest wood just fine with the help of some very special symbiotic bacteria. But here’s the strange thing: That bacteria doesn’t live in the shipworm’s gut. Instead, it lives in the gills and produces enzymes that make their way to the gut, where they break down the wood’s cellulose into sugars. Plenty of creatures use bacteria like this to digest weird foods, but the shipworm is alone in storing the microbes outside of its digestive system.

A diet of wood, though, leaves the shipworm wanting for protein. So out of that tiny hole it first bored when it was a larva, the shipworm extends fan-like structures that it uses to catch plankton floating by. “So imagine that you have a lot of shipworms in a piece of wood, and they don’t have much wood to eat,” says Borges. “They actually filter-feed more than they eat wood. Otherwise they destroy their own environment. So they can kind of adjust their diet to survive.”

Read more at Wired Science

Jun 11, 2015

IQ Tests Suggest Pigs Are Smart as Dogs, Chimps

Pigs can often outsmart dogs and are on about the same intellectual level as our closest living relatives, chimpanzees, according to a new paper.

The research project, described in a paper published in the International Journal of Comparative Psychology, aims to put a face on animals that are traditionally just viewed as sources of meat.

“We have shown that pigs share a number of cognitive capacities with other highly intelligent species such as dogs, chimpanzees, elephants, dolphins, and even humans,” neuroscientist Lori Marino of Emory University and The Nonhuman Rights Project said in a press release. “There is good scientific evidence to suggest we need to rethink our overall relationship to them.”

Marino and co-author Christina Colvin, also from Emory, came to that conclusion after reviewing dozens of studies conducted on pigs and other animals. Often studies on cognition and behavior focus on only a single characteristic, so the researchers in this case compiled the findings into a single document.

They found that pigs:

  • have excellent long-term memories
  • are whizzes with mazes and other tests requiring location of objects
  • can comprehend a simple symbolic language and can learn complex combinations of symbols for actions and objects
  • love to play and engage in mock fighting with each other, similar to play in dogs and other mammals

    live in complex social communities where they keep track of individuals and learn from one another
  • cooperate with one another
  • can manipulate a joystick to move an on-screen cursor, a capacity they share with chimpanzees
  • can use a mirror to find hidden food
  • exhibit a form of empathy when witnessing the same emotion in another individual

Contrast these abilities with the way that pigs are often treated in factory farms. PETA reports that mother pigs (sows) spend most of their lives in what are known as “gestation crates,” which do not even allow the pigs to turn around. Once they give birth, they are impregnated again, with the cycle continuing for three or four years before the mother is slaughtered.

PETA goes on to mention that “in extremely crowded conditions, piglets are prone to stress-related behavior such as cannibalism and tail-biting, so farmers often chop off piglets’ tails and use pliers to break off the ends of their teeth–without giving them any painkillers.”

Read more at Discovery News

1,500-Year-Old Church Found Near Israel's Main Highway

Workers widening Israel’s main highway between Jerusalem and Tel Aviv have stumbled upon the remnants of a 1,500-year-old church, Israel officials said on Wednesday.

Located at the entrance to Abu Gosh, a village some eight miles west of Jerusalem, the church was part of a Byzantine period road station which provided spiritual and material refreshments to those traveling between Jerusalem and the coastal plain.

“Along this road, which was apparently already established in the Roman period, other settlements and road stations have previously been discovered that served those traveling the route in ancient times,” Annette Nagar, director of the excavation on behalf of the Israel Antiquities Authority, said.

Measuring about 52 feet in length, the church featured a white mosaic floor and a side chapel 21 feet long and 11 feet wide.

A baptismal font in the form of a four-leafed clover, symbolizing the cross, was found in the chapel’s northeast corner, the Israel Antiquities Authority said.

Fragments of red-colored plaster suggest the church walls had been decorated with frescoes.

Next to the church, the archaeologists found rooms that were probably used as dwelling quarters and for storage. One of them contained a large amount of pottery tiles.

The site had a water source — the ‘Ain Naqa’a seep spring — and likely witnessed intense activity, as shown by numerous findings which include oil lamps, coins, special glass vessels, marble fragments and mother-of-pearl shells.

“The road station ceased to be used at the end of the Byzantine period, although the road beside which it was built was renewed and continued to be in use until modern times,” Nagar said.

The road station and church remnants will soon disappear from view. Archaeologist Pablo Betzer said a decision was made “to cover over the site and preserve it for future generations.”

From Discovery News

Excess Trees in Japan are Harming the Environment

Can trees cause pollution?

Short answer: yes -- mismanaged forests can cause nutrient pollution. Cypress and cedar trees in Japan are causing massive amounts of nitrogen runoff into local streams, resulting in harmful algae blooms.

But, it's not exactly their fault. The trees are planted in massive, commercial plantations, many of which have mostly fallen into a state of disrepair since their establishment half a century ago, during a period of high demand for wood within Japan. For a variety of reasons, Japanese companies began to increasingly import wood in subsequent decades. The shift in the market left in its wake an overabundance of humungous wood plantations, which are now causing major problems for adjacent wildlife in their sad state of ruination.

The older, slowly growing trees use notably less nutrients (namely nitrogen) than younger trees, which grow faster and require more nutrients. Very few new trees are growing in the plantations because the land has become so densely populated with older trees, which prevent sunlight from nourishing the shorter, nascent trees.

As such, there is an unusually high concentration of nitrogen in the soil on the plantations, which is left to run off into neighboring waterways. Algae blooms have begun to form in the highly nitrogenous marine habitats, and are problematic for existing wildlife: The algae sucks oxygen out of the water, and other marine wildlife are unable to survive (a process known as eutrophication).

According to the American Society of Agronomy, the problem is widespread: these large plantations account for up to 30 percent of forestland across Japan.

Kyushu University's Masaaki Chiwa, who penned a new study about the issue, says that the process can be prevented by adequate forest management. Chiwa is encouraging the owners of the large plantations to thin them out, creating room for new, smaller trees to grow and utilize the abundant nutrients in the soil. His team is already investigating the impact of recent trimming operations on local waterways.

"We have been measuring water quality to evaluate the effect of forest thinning on water quality including nitrogen loss," he says.

From Discovery News

Helium-Filled Exoplanets Likely Float Throughout the Galaxy

Although our solar system doesn’t contain gas giants with thick atmospheres enriched with helium, observations by NASA’s Spitzer Space Telescope suggests the galaxy may be strewn with these planetary oddities.

“We don’t have any planets like this in our own solar system,” said Renyu Hu, of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., in a news release. “But we think planets with helium atmospheres could be common around other stars.” Hu is lead author of a new study published in the Astrophysical Journal.

While hunting for a specific class of exoplanet, known as “warm-Neptunes,” Hu’s team realized that many of these worlds could be baked by their host stars so much that the majority of the hydrogen in their atmospheres would boil off, leaving an enriched helium atmosphere behind.

Many warm-Neptunes studied are roughly the same size as our solar system’s blue-hued, hydrogen-rich “ice giant” of the same name. Neptune and Uranus are often referred to as ice giants due to their higher proportion of ices — such as water, ammonia and methane.

But warm-Neptunes, owing to their close proximity to their host stars, likely have very different compositions, chiefly the lack of hydrogen.

“Hydrogen is four times lighter than helium, so it would slowly disappear from the planets’ atmospheres, causing them to become more concentrated with helium over time,” said Hu. “The process would be gradual, taking up to 10 billion years to complete.”

Hu’s team was led to this finding through the study of GJ 436b, a warm Neptune located over 33 light-years away, with Spitzer. When studying the light reflected from GJ 436b (also known as Gliese 436b), the researchers noticed something striking — the exoplanet’s atmosphere had a distinct lack of methane.

Our own Neptune contains methane, a molecule that absorbs red light, creating the ice giant’s beautiful rich blue hue we all know and love. But GJ 436b contains little to no methane, and yet is apparently rich in carbon. As methane contains one carbon atom linked with four hydrogen atoms (CH4), methane should be present — unless the world is missing a key component: hydrogen.

Instead of linking up with hydrogen, the carbon atoms are linking with oxygen, creating an enriched carbon monoxide (CO) and carbon dioxide (CO2) atmosphere, indicators that this class of exoplanet is abundant in helium, the next most abundant gas in the galaxy after hydrogen. Sure enough, Spitzer has also deduced a strong chemical signature for carbon monoxide in GJ 436b’s atmosphere, showing that there is a lack of hydrogen and likely an abundance of helium.

Read more at Discovery News

Jun 10, 2015

Ultracold molecules created

The air around us is a chaotic superhighway of molecules whizzing through space and constantly colliding with each other at speeds of hundreds of miles per hour. Such erratic molecular behavior is normal at ambient temperatures.

But scientists have long suspected that if temperatures were to plunge to near absolute zero, molecules would come to a screeching halt, ceasing their individual chaotic motion and behaving as one collective body. This more orderly molecular behavior would begin to form very strange, exotic states of matter -- states that have never been observed in the physical world.

Now experimental physicists at MIT have successfully cooled molecules in a gas of sodium potassium (NaK) to a temperature of 500 nanokelvins -- just a hair above absolute zero, and over a million times colder than interstellar space. The researchers found that the ultracold molecules were relatively long-lived and stable, resisting reactive collisions with other molecules. The molecules also exhibited very strong dipole moments -- strong imbalances in electric charge within molecules that mediate magnet-like forces between molecules over large distances.

Martin Zwierlein, professor of physics at MIT and a principal investigator in MIT's Research Laboratory of Electronics, says that while molecules are normally full of energy, vibrating and rotating and moving through space at a frenetic pace, the group's ultracold molecules have been effectively stilled -- cooled to average speeds of centimeters per second and prepared in their absolute lowest vibrational and rotational states.

"We are very close to the temperature at which quantum mechanics plays a big role in the motion of molecules," Zwierlein says. "So these molecules would no longer run around like billiard balls, but move as quantum mechanical matter waves. And with ultracold molecules, you can get a huge variety of different states of matter, like superfluid crystals, which are crystalline, yet feel no friction, which is totally bizarre. This has not been observed so far, but predicted. We might not be far from seeing these effects, so we're all excited."

Zwierlein, along with graduate student Jee Woo Park and postdoc Sebastian Will -- all of whom are members of the MIT-Harvard Center of Ultracold Atoms -- have published their results in the journal Physical Review Letters.

Sucking away 7,500 kelvins

Every molecule is composed of individual atoms that are bonded together to form a molecular structure. The simplest molecule, resembling a dumbbell, is made up of two atoms connected by electromagnetic forces. Zwierlein's group sought to create ultracold molecules of sodium potassium, each consisting of a single sodium and potassium atom.

However, due to their many degrees of freedom -- translation, vibration, and rotation -- cooling molecules directly is very difficult. Atoms, with their much simpler structure, are much easier to chill. As a first step, the MIT team used lasers and evaporative cooling to cool clouds of individual sodium and potassium atoms to near absolute zero. They then essentially glued the atoms together to form ultracold molecules, applying a magnetic field to prompt the atoms to bond -- a mechanism known as a "Feshbach resonance," named after the late MIT physicist Herman Feshbach.

"It's like tuning your radio to be in resonance with some station," Zwierlein says. "These atoms start to vibrate happily together, and form a bound molecule."

The resulting bond is relatively weak, creating what Zwierlein calls a "fluffy" molecule that still vibrates quite a bit, as each atom is bonded over a long, tenuous connection. To bring the atoms closer together to create a stronger, more stable molecule, the team employed a technique first reported in 2008 by groups from the University of Colorado, for potassium rubidium (KRb) molecules, and the University of Innsbruck, for non-polar cesium­ (Ce2­) molecules.

For this technique, the newly created NaK molecules were exposed to a pair of lasers, the large frequency difference of which exactly matched the energy difference between the molecule's initial, highly vibrating state, and its lowest possible vibrational state. Through absorption of the low-energy laser, and emission into the high-energy laser beam, the molecules lost all their available vibrational energy.

With this method, the MIT group was able to bring the molecules down to their lowest vibrational and rotational states -- a huge drop in energy.

"In terms of temperature, we sucked away 7,500 kelvins, just like that," Zwierlein says.

Chemically stable

In their earlier work, the Colorado group observed a significant drawback of their ultracold potassium rubidium molecules: They were chemically reactive, and essentially came apart when they collided with other molecules. That group subsequently confined the molecules in crystals of light to inhibit such chemical reactions.

Zwierlein's group chose to create ultracold molecules of sodium potassium, as this molecule is chemically stable and naturally resilient against reactive molecular collisions.

"When two potassium rubidium molecules collide, it is more energetically favorable for the two potassium atoms and the two rubidium atoms to pair up," Zwierlein says. "It turns out with our molecule, sodium potassium, this reaction is not favored energetically. It just doesn't happen."

In their experiments, Park, Will, and Zwierlein observed that their molecular gas was indeed stable, with a relatively long lifetime, lasting about 2.5 seconds.

"In the case where molecules are chemically reactive, one simply doesn't have time to study them in bulk samples: They decay away before they can be cooled further to observe interesting states," Zwierlein says. "In our case, we hope our lifetime is long enough to see these novel states of matter."

By first cooling atoms to ultralow temperatures and only then forming molecules, the group succeeded in creating an ultracold gas of molecules, measuring one thousand times colder than what can be achieved by direct cooling techniques.

Read more at Science Daily

Lonely galaxy 'lost in space'

Although the Universe may seem spacious most galaxies are clumped together in groups or clusters and a neighbour is never far away. But this galaxy, known as NGC 6503, has found itself in a lonely position, shown here at the edge of a strangely empty patch of space called the Local Void. This new NASA/ESA Hubble Space Telescope image shows a very rich set of colours, adding to the detail seen in previous images.

NGC 6503 is only some 18 million light-years away from us in the constellation of Draco (The Dragon), making it one of the closest neighbours from our Local Group. It spans some 30,000 light-years, about a third of the size of the Milky Way. The galaxy's lonely location led stargazer Stephen James O'Meara to dub it the "Lost-In-Space galaxy" in his 2007 book Hidden Treasures.*

This galaxy does not just offer poetic inspiration; it is also the subject of ongoing research. The Hubble Legacy ExtraGalactic UV Survey (LEGUS) is exploring a sample of nearby galaxies, including NGC 6503, to study their shape, internal structure, and the properties and behaviour of their stars. This survey uses 154 orbits of time on Hubble; by contrast, a typical Hubble observing programme lasts from a few to a few tens of orbits.

The Local Void is a patch of space thought to be about 150 million light-years across that seems to be curiously devoid of galaxies. Astronomers using Hubble discovered that the emptiness of this region has quite an effect on the space around us -- the Milky Way is being strongly pulled away from it by the gentle but relentless tug of other nearby galaxies.

NGC 6503 lies right on the edge of this void. It has an almost non-existent central bulge surrounded by a massive halo of gas. The galaxy's central region is a good example of something known as a "low ionisation nuclear emission region," or LINER. These are less luminous than some of the brightest galaxies. Emission from NGC 6503's heart is believed to be the result of a starved black hole that is only just being kept active, receiving a very small amount of infalling gas to keep its large appetite at bay.

A previous image of NGC 6503 was released as a Hubble Picture of the Week back in 2010, taken by Hubble's Advanced Camera for Surveys. However, this new image, taken using Hubble's Wide Field Camera 3 (WFC3), shows NGC 6503 in striking detail and with a richer set of colours. Bright red patches of gas can be seen scattered through its swirling spiral arms, mixed with bright blue regions that contain newly-forming stars. Dark brown dust lanes snake across the galaxy's bright arms and centre, giving it a mottled appearance.

Read more at Science Daily

Whale in Whale in Shark Found in Egypt

A Russian nesting doll of marine fossils has been uncovered in Egypt’s Valley of the Whales: a prehistoric whale ate a smaller whale, and then they were both devoured by a massive shark.

The larger whale, Basilosaurus, grew up to 65 feet, and is believed to be the largest known ocean animal from the Late Eocene Period, approximately 35 million years ago.

It appears that the large Basilosaurus ate a smaller Basilosaurus — although researchers haven’t ruled out the possibility that the smaller whale could be a fetus.

Based on shark teeth found in close proximity to the two whales’ remains, paleontologists believe that a giant shark then feasted on the two whales.

The Valley of Whales is home to numerous fossilized whale remains. Since the Unesco World Heritage Site’s discovery in 1902, 10 prehistoric whales have been identified, although this find marks the first complete Basilosaurus discovery.

From Discovery News

Frozen Ovarian Tissue Produces Baby Decade Later

A 27-year-old woman in Belgium is now a mom after giving birth to a baby more than a decade after her ovarian tissue was removed and frozen, according to a new study.

The woman had her ovarian tissue frozen in her early teens, before she underwent a bone marrow transplant to treat her sickle cell anemia. Such transplants involve drugs that can destroy the ovaries.

The method that the researchers used to freeze the ovarian tissue could spare fertility in other girls who must undergo serious medical treatments during childhood, according to the study.

“Children are the patients who are most likely to benefit from the procedure in the future. When they are diagnosed with diseases that require treatment that can destroy ovarian function, freezing ovarian tissue is the only available option for preserving their fertility,” Dr. Isabelle Demeestere, a gynecologist at the Erasmus Hospital at the Free University of Brussels, Belgium, and study co-author, said in a statement.

Sickle cell disease

The woman was born in the Congo and was diagnosed at age 5 with sickle cell anemia, a sometimes deadly disease that prevents red blood cells from carrying enough oxygen to the body’s tissues. She moved to Belgium when she was 11, and her sickle cell anemia progressively worsened. Soon after her move, it became clear she needed a bone marrow transplant.

However, such transplants require that a patient first undergo chemotherapy to wipe out the immune system and prevent it from attacking the new bone marrow. Chemotherapy also damages DNA, and thus can prevent the person’s ovaries or testes from later producing eggs or sperm. Women who want to have children after chemotherapy can have their eggs extracted and frozen prior to treatment, but prepubertal girls do not yet have mature eggs that can be extracted.

Fertility-sparing operation

In this patient’s case, doctors hoped to spare her fertility by removing her right ovary before she began her chemotherapy. They performed the procedure when she was about 13 — before she had begun menstruating, but after her breasts had developed (a sign that puberty was underway).

The bone marrow transplant was ultimately successful in treating the woman’s sickle cell anemia, but her left ovary failed when she was 15. Afterward, she began taking hormone replacement therapy to initiate menstrual cycles.

Ten years later, the woman wanted to have a child. Doctors thawed some of her ovarian tissue, grafted four pieces onto what remained of her left ovary and 11 other pieces into her abdomen. She also stopped taking the hormone replacement therapy.

Healthy baby boy

Eventually, her transplanted ovarian tissue responded to the natural hormones circulating in her body, and developed follicles, which hold mature eggs. Two years after the transplant, she conceived a baby naturally, and gave birth to a healthy boy in November 2014.

The woman’s case suggests that it is possible to preserve fertility in girls who have not yet reached puberty and must undergo treatments such as chemotherapy or radiation.

However, it’s not clear whether the same technique would be successful in younger children, as the girl had already started puberty when the operation was done, the researchers noted in the article, which was published today (June 9) in the journal Human Reproduction.

Read more at Discovery News

Monstrous Star-Forming Regions Seen in Ancient Galaxy

When the Atacama Large Millimeter/submillimeter Array (ALMA) first imaged this near-perfect Einstein Ring in the depths of space, the detail and geometry of this beautiful quirk in spacetime captivated the world.

Now that astronomers have had time to pore over the data recorded by the huge observatory, located in the Chilean Atacama Desert, some intriguing details have begun to emerge from the warped galaxy called SDP.81, chiefly that it contains some of the most distant and massive star formation regions ever seen. This galaxy was forming in the first billion years after the Big Bang.

“The reconstructed ALMA image of the galaxy is spectacular,” said Rob Ivison, ESO’s Director for Science and co-author on two recent papers based on SDP.81. “ALMA’s huge collecting area, the large separation of its antennas, and the stable atmosphere above the Atacama desert all lead to exquisite detail in both images and spectra. That means that we get very sensitive observations, as well as information about how the different parts of the galaxy are moving. We can study galaxies at the other end of the Universe as they merge and create huge numbers of stars. This is the kind of stuff that gets me up in the morning!”

Gravitational lensing occurs when a massive object, like a black hole, galaxy or even cluster of galaxies pass in front of a more distant galaxy. The foreground mass can act as a natural “lens” in spacetime, magnifying the starlight from the more distant galaxy.

This occurs because the lens’ mass will create a curvature of the spacetime surrounding it, thereby deflecting the light from the more distant galaxy. This cosmic effect has been put to great use by the Hubble Space Telescope for example, where the “Frontier Fields” project looks out for gravitationally-lensed galaxies in the hope of super-boosting Hubble’s magnifying power.

Often, lensed galaxies appear as arcs, but sometimes, if the alignment is near-perfect, the distant galaxy can form an Einstein Ring, named after Albert Einstein who formulated the equations of general relativity 100 years ago. Gravitational lenses are cosmic proof of Einstein’s theories, showing that spacetime warps around massive objects as the physicist predicted.

Read more at Discovery News

Jun 9, 2015

Lamprey Eels Fall From Sky Over Alaska

Several foot-long lampreys have apparently fallen out the sky recently in Fairbanks, Alaska. They’ve been found in a shopping center parking lot and on lawns, and residents are unnerved by the creepy, toothed eel-like fish.

According to a story in the Alaska News-Miner, “Adult Arctic lampreys have fallen from the sky four times this week in Fairbanks, including at the Value Village parking lot, according to the Alaska Department of Fish and Game. That’s unusual for a fish that’s seldom seen in the water up here.”

While some news outlets had fun sensationalizing the story (a “New York” magazine headline blared that “Horrifying Fish Monsters Are Falling from the Sky” and another noted that “‘Vampire Fish’ Fall From the Sky in Alaska”) it’s a weird enough story on its own.

The phenomenon of small animals (such as worms, fish, or frogs) falling mysteriously from the sky has been reported for centuries. Waterspouts or tornadoes crossing over a lake or river can pick up debris, including lightweight aquatic animals, and carry them for miles before raining them down on a puzzled populace. There were no reported tornadoes or waterspouts in Fairbanks, however.

It could be a prank, but the most likely explanation for the falling lampreys was offered by the Alaska Department of Fish and Game: they’re dropped from the air by seagulls. Seagulls can often be seen feeding on lampreys and small fish in and over the water, but they don’t always eat their prey on the spot. Sometimes they fly away with their marine lunch in their beaks, and on occasion the birds will accidentally drop their meal before it’s consumed.

In those cases a lamprey may be found some distance from its aquatic home, and unless a person happens to be watching a seagull as the bird drops its meal, a lamprey would appear to fall from the sky (or be found on a sidewalk) without any apparent origin.

A grand total of four lampreys have been found over the past week—hardly a deluge—and the fact that dead lampreys are rarely seen up close by the general public (being difficult to catch and not sold commercially in the area) may have added to the unnerving effect.

Read more at Discovery News

Are Bumblebees Getting Alzheimer's?

It’s no secret that bees are in crisis right now -- a recent 40 percent decline in bee populations has been blamed on harmful pesticides and mite infestations, but researchers have now identified yet another potential threat to the pollinators: aluminum.

According to a new joint study from Keele University and the University of Sussix, bumblebees are now suffering from troubling amounts of aluminum contamination, which could be the cause of debilitating cognitive dysfunction.

“Aluminum is a known neurotoxin affecting behavior in animal models of aluminum intoxication. Bees, of course, rely heavily on cognitive function in their everyday behavior and these data raise the intriguing specter that aluminum-induced cognitive dysfunction may play a role in their population decline: are we looking at bees with Alzheimer’s disease?” said Keele’s Chris Exley in a press release.

Exely and his colleague Dave Goulson tested the aluminum levels of pupae from bumblebee colonies. Whereas an aluminum level of 3ppm would be harmful to human brain tissue, some pupae were found to have aluminum levels as high as 200ppm.

The excess aluminum has a variety of origins, according to Exely and Goulson. “Human activities such as the burning of fossil fuels resulting in ‘acid rain,’ intensive agriculture producing acid sulphate soils and the mining of aluminum ores to make aluminum metal and salts have all contributed to the burgeoning biological availability of this non-essential metal,” they wrote.

Previous research has already linked high levels of aluminum exposure to the death of fish in acid lakes and low crop productivity in acidified soils.

From Discovery News

Once-Abundant Bird Being Eaten to Extinction

A bird that was once one of the most abundant in Europe and Asia is being hunted to near extinction because of Chinese eating habits, according to a study published on Tuesday.

The population of the yellow-breasted bunting has plunged by 90 percent since 1980, all but disappearing from eastern Europe, Japan and large parts of Russia, said the study, published in the Conservation Biology journal.

Following initial population declines, China in 1997 banned the hunting of the species, known in the country as the “rice bird.”

However, millions of these birds, along with other songbirds, were still being killed for food and sold on the black market as late as 2013, said the study.

It said consumption of these birds has increased as a result of economic growth and prosperity in East Asia, with an estimate in 2001 claiming one million buntings were consumed in China’s southern Guangdong province alone.

The birds breed north of the Himalayas and spend their winters in warmer southeast Asia, passing through eastern China where they have been hunted for more than 2,000 years, according to the conservation group BirdLife International.

At their wintering grounds, they gather in huge flocks at night-time roosts, making them easy prey for trappers using nets, the group said.

The songbird, which nests on the ground in open scrubs, is distinctive for its yellow underparts.

The paper in Conservation Biology drew parallels between the migratory bird and the North American passenger pigeon, which became extinct in 1914 due to industrial-scale hunting.

“The magnitude and speed of the decline is unprecedented among birds distributed over such a large area, with the exception of the passenger pigeon,” the paper’s lead author, Johannes Kamp from the  University of Munster, said in a statement released by BirdLife International.

Read more at Discovery News

Tracking Titanosaurs in Argentina

Dinosaurs aren't just tracked down in movies like "Jurassic World." Scientists in Argentina are tracking titanosaurs -- the largest sauropod dinosaurs and among the last to walk the Earth.

Researchers uncovered at least one footprint so clear it can be matched for the first time to skeletal remains of a new species of titanosaur that's found in the same region of Argentina.

The hundreds of new titanosaur tracks found at the Agua del Choique site, in the Mendoza Province, are revealing secrets about how titanosaurs walked. The tracks also provide clues about other dinos, which strolled along muddy paths near the shores of a small, new sea that grew to become the Atlantic Ocean.

The most telling titanosaur track discovered at the site belonged to an animal estimated to have been a mid-sized titanosaur: some 7 1/2 feet (2.29 meters) high at the hip and 40 to 45 feet (12 to 14 meters) long. The largest-known titanosaurs, Argentinosaurus, are thought to have ranged from 100 to 130 feet (30-40 meters) long and up to 24 feet (7.3 meters) high.

“Most sauropod tracks simply look like post holes,” said paleontologist Spencer Lucas, curator at the New Mexico Museum of Natural History and Science in Albuquerque who was not involved in the discovery. “Tracks in which you can see digit imprints are rather rare, so (it's) a remarkable tracksite for sauropod tracks.”

“Although other studies have documented impressions of digits or claws in titanosaurs, they are poorly defined” and don't reveal much useful information that can be compared to fossil bones, explained Bernardo Javier González Riga of Argentina's National University of Cuyo.

Riga and his colleagues are publishing their discovery of the matching track and fossil in the August 2015 issue of the Journal of South American Earth Sciences.

The fossil bones the remarkable track matched were found just 150 miles (250 kilometers) away, in the same red rocks.

“Anatomically, the record of (intact) and complete (hind feet) is really scarce in titanosaurs,” Riga reported. In fact, of the 65 species of titanosaurs known worldwide, only three have intact fossils of their feet, he writes.

That's not to say that the bones belonged to the same individual that made the tracks -- they're not only far apart in space, but also in time. But they do belong to a similar titanosaur.

“Not all tracks can be matched to specific skeletons because foot structures do not vary that much in some dinosaur groups,” Lucas said. “Relatively few dinosaur tracks have been matched with certainty to a dinosaur (type). Sometimes, the bones from one rock formation are claimed to represent the trackmaker of tracks in the same formation, but even this is not often a certain link.”

Among the other things revealed by the trackways are just how fast some of the titanosaurs walked across the muddy ground they encountered in the late Cretaceous.

Read more at Discocvery News

Jun 8, 2015

America's First 'Casino' Found in Utah Cave

Long before Las Vegas, people were apparently gambling in what might be America’s first casino — a cave on the shore of Utah’s Great Salt Lake.

Archaeologists exploring the site, known simply as Cave 1, have unearthed hundreds of carved sticks, hoops, dice and darts dating back to about 700 years ago. They believe there could be up to 10,000 gambling pieces in the cave.

According to John “Jack” Ives, an archaeologist at the University of Alberta who has been researching the cave for years, at least two or three forms of dice games were played.

Other entertainments included the hoop and dart game, consisting in throwing a dart through a hoop to score different points, and a stick game, in which a marked stick was hidden among others.

“Also, we found bone hand game pieces. Contestants had to guess in which hand a marked bone object had been concealed,” Ives told Discovery News.

The cave was used as a social space to an obscure culture known as the Promontory that lived along the shores of the Great Salt Lake in the 13th century.

“The wide distribution and variety of games in the cave affirm that we are looking at a migrating Apachean population,” Ives said.

He believes the Promontory people migrated into the area after a long journey from their native land in the Canadian Subarctic.

The cave was first excavated in the 1930s by Julian Steward from the University of Utah, but not until recently its importance was fully understood.

Ives and colleagues at Brigham Young University are now studying the gambling artifacts in relation with other objects unearthed in the cave in previous excavations. These included pilies of butchered bison, elk bones and hundreds of animal-skin moccasins ranging from a small child’s size to an adult’s.

“Because there are so many moccasins in the caves, and because this became an important game for Apache and Navajo people, it possible the moccasin game was played in Cave 1,” Ives said.

The game consisted of guessing where an object was concealed in one of four or eight moccasins.

The cave was intensively occupied between 1240 and 1290 A.D., a time when the Promontory people was thriving and other cultures, like the nearby Fremont, were struggling to survive.

“In North America, the 13th century saw perhaps unprecedented turmoil, brought about by complex environmental and social factors, one of them apparently being a severe drought in the last quarter of the 13th century,” Ives told Westerndigs.org.

“But the Promontory Culture cave inhabitants were well clothed and well fed. As nearly as we can tell, surrounding Fremont populations were not doing well and were likely to be disintegrating,” he added.

Ives and colleagues believe gaming was in Cave 1 is was a luxury for people who had time and resources to spend for such a form of entertainment.

Most of the game pieces unearthed are dice, made from split pieces of cane, with cut or burned lines on one side and the other side plain.

The majority were found near the entrance of the cave around a large central hearth. According to Ives, they were typically played by women for low stakes.

“At Promontory women did a great deal of work. It does seem likely that the fun and excitement of games played could break up the monotony of that work,” he said.

But gambling wasn’t just a matter of recreational, low stakes play by the fire. In certain cases, it involved higher stakes and physical activity between men of different social groups.

Read more at Discovery News

Rome Colosseum Unveils Wild Beasts Trapdoor

It was the last thing they would see: a trapdoor opening in the floor of the Colosseum to unleash a snarling lion or bear, which sprang for the jugular as the crowds roared.

Where prisoners sentenced to a grisly death in ancient Rome’s most barbaric playground once quaked in their sandals, today tourists can explore the cage that carried their killers thanks to a reconstruction in the ancient arena.

The seven-meter high (23-foot) wooden machine, powered by slaves deep in the stadium’s belly, could lift a load weighing 300 kilograms and brought wolves, boars and even antelopes to do battle with the empire’s fiercest gladiators.

“This unique project began with a meeting with the (American) director Gary Glassman” in 2013, the site’s director Rossella Rea said.

Glassman wanted to recreate one of the arena’s 28 lifts for a documentary entitled “Colosseum, Roman Death Trap,” and Rea persuaded him to use original materials and methods to reconstruct one which would remain there for tourists.

Now visitors to the passageways under the 2,000-year-old monument can see where eight slaves straining to rotate a vast windlass would, through a system of lead weights and pulleys, slowly winch the cage to the surface and open the trapdoor.

Up to 80,000 spectators at a time would throng to the Colosseum to see greats such as Carpophores — who reportedly defeated a bear, lion, leopard and rhinoceros in one battle — or cheer on sea battles held in the flooded arena.

- ‘Roman Genius’ -

Rome’s rulers “had to enthral them, for the good of the empire,” said Francesco Prosperetti, superintendent for Rome’s Archaeological Heritage, adding that some 120 days of festivities were put on a year to keep the plebeians happy.

The idea was keep the baying audience on its toes: sometimes the trapdoor in the sand would creak open to reveal a surprise, from bare-breasted female gladiators to elephants, or sometimes even common garden chickens.

Building the cage, which measures 180 by 140 centimeters (71 by 55 inches), took 15 months and cost the production company some 200,000 euros ($223,000).

Read more at Discovery News

How the Brain Remembers Colors

When you bring home the wrong color of paint from the hardware store, it may not be your foggy memory at fault. A new study finds that while the human brain can distinguish between millions of colors, it has difficulty remembering specific shades.

For example, most people can easily tell the difference between azure, navy and ultramarine, but when it comes to remembering these shades, people tend to label them all as blue, the study found. This tendency to lump colors together could explain why it’s so hard to match the color of house paint based on memory alone, the researchers said.

Many cultures have the same color words or categories, said Jonathan Flombaum, a cognitive psychologist at Johns Hopkins University in Baltimore. “But at the same time, there’s a lot of debate around the role those categories play in the perception of color,” he said.

In the study, Flombaum and his colleagues conducted four experiments on four different groups of people. In the first experiment, they asked people to look at a color wheel with 180 different hues, and asked them to find the best name for each color. The exercise was designed to find the perceived boundaries between colors, the researchers said. In a second experiment, the scientists showed different people the same colors, but this time they asked them to find the “best example” of a particular color.

For a third experiment, the researchers showed participants colored squares, and asked them to select the best match on the color wheel. In a fourth experiment, another group of participants completed the same task, but there was a delay of 90 milliseconds between when each color square was displayed and when they were asked to select the best match on the color wheel.

The results revealed that categories are indeed important in how people identify and remember colors. The participants who were asked to name the colors reliably saw five hues: blue, yellow, pink, purple and green. Most of the colors were given one name, butambiguous colors got two labels, such as blue and green. “Where that fuzzy naming happened, those are the boundaries” between colors, Flombaum told Live Science. In addition, people tended to choose the same shades as the best example of each color.

But what was really striking was how the people in the memory experiment remembered the colors they saw, the scientists said.

The researchers expected that the participants’ responses for what colors they had seen would reflect a bell curve centered on the correct color. But instead, they found that the distribution of responses was skewed toward the “best example” of the color they had seen, not the true color.

Read more at Discovery News

Solar Sail Spacecraft Back From the Dead

Ground control teams hope to get confirmation early Monday that an experimental spacecraft successfully deployed its solar sail, a key milestone to prepare for an operational mission next year.

Engineers working on the privately funded LightSail project wrestled with a computer software glitch and a troubled battery before the tiny spacecraft’s motor began unfurling an extremely thin 340-square-foot sail on Sunday afternoon.

The Planetary Society, a California-based non-profit space advocacy group, is keen to demonstrate an alternative space propulsion system known as solar sailing. The technology uses the pressure of photons of sunlight bouncing off a very thin film sail to generate forward motion, similar to how a boat’s sail can harness the wind.

LightSail-A hitched a ride into orbit on May 20 aboard an Atlas 5 rocket that carried the military’s X-37B miniature robotic shuttle.

Two days after launch, LightSail, which is about the size of a loaf of bread, fell silent, the victim of a computer software glitch. After more than a week, a stray cosmic ray hit rebooted LightSail’s computer and engineers proceeded with deployment of the spaceraft’s solar panel.

Then another problem, believed to be with the battery, halted operations on Wednesday, before engineers could deploy the spacecraft’s sails, the primary goal of the mission.

After three days of silence,  LightSail transmitted data on Saturday showing its batteries were changing for the first time since solar panel deployment.

“LightSail is back in business,” Planetary Society wrote on its website.

With battery levels appearing to continue to increase, project managers proceeded with the sail deployment at 3:47 p.m. EDT Sunday as the spacecraft flew off the coast of Baja California, Mexico.

Read more at Discovery News

Jun 7, 2015

Unlocking nanofibers' potential

Nanofibers -- polymer filaments only a couple of hundred nanometers in diameter -- have a huge range of potential applications, from solar cells to water filtration to fuel cells. But so far, their high cost of manufacture has relegated them to just a few niche industries.

In the latest issue of the journal Nanotechnology, MIT researchers describe a new technique for producing nanofibers that increases the rate of production fourfold while reducing energy consumption by more than 90 percent, holding out the prospect of cheap, efficient nanofiber production.

"We have demonstrated a systematic way to produce nanofibers through electrospinning that surpasses the state of the art," says Luis Fernando Velásquez-García, a principal research scientist in MIT's Microsystems Technology Laboratories, who led the new work. "But the way that it's done opens a very interesting possibility. Our group and many other groups are working to push 3-D printing further, to make it possible to print components that transduce, that actuate, that exchange energy between different domains, like solar to electrical or mechanical. We have something that naturally fits into that picture. We have an array of emitters that can be thought of as a dot-matrix printer, where you would be able to individually control each emitter to print deposits of nanofibers."

Tangled tale

Nanofibers are useful for any application that benefits from a high ratio of surface area to volume -- solar cells, for instance, which try to maximize exposure to sunlight, or fuel cell electrodes, which catalyze reactions at their surfaces. Nanofibers can also yield materials that are permeable only at very small scales, like water filters, or that are remarkably tough for their weight, like body armor.

The standard technique for manufacturing nanofibers is called electrospinning, and it comes in two varieties. In the first, a polymer solution is pumped through a small nozzle, and then a strong electric field stretches it out. The process is slow, however, and the number of nozzles per unit area is limited by the size of the pump hydraulics.

The other approach is to apply a voltage between a rotating drum covered by metal cones and a collector electrode. The cones are dipped in a polymer solution, and the electric field causes the solution to travel to the top of the cones, where it's emitted toward the electrode as a fiber. That approach is erratic, however, and produces fibers of uneven lengths; it also requires voltages as high as 100,000 volts.

Thinking small

Velásquez-García and his co-authors -- Philip Ponce de Leon, a former master's student in mechanical engineering; Frances Hill, a former postdoc in Velásquez-García's group who's now at KLA-Tencor; and Eric Heubel, a current postdoc -- adapt the second approach, but on a much smaller scale, using techniques common in the manufacture of microelectromechanical systems to produce dense arrays of tiny emitters. The emitters' small size reduces the voltage necessary to drive them and allows more of them to be packed together, increasing production rate.

At the same time, a nubbly texture etched into the emitters' sides regulates the rate at which fluid flows toward their tips, yielding uniform fibers even at high manufacturing rates. "We did all kinds of experiments, and all of them show that the emission is uniform," Velásquez-García says.

To build their emitters, Velásquez-García and his colleagues use a technique called deep reactive-ion etching. On either face of a silicon wafer, they etch dense arrays of tiny rectangular columns -- tens of micrometers across -- which will regulate the flow of fluid up the sides of the emitters. Then they cut sawtooth patterns out of the wafer. The sawteeth are mounted vertically, and their bases are immersed in a solution of deionized water, ethanol, and a dissolved polymer.

Read more at Science Daily

Researchers design the most precise quantum thermometer to date

Researchers from the UAB and the University of Nottingham, in an article published in Physical Review Letters, have fixed the limits of thermometry, i.e., they have established the smallest possible fluctuation in temperature which can be measured. The researchers have studied the sensitivity of thermometers created with a handful of atoms, small enough to be capable of showing typical quantum-style behaviours.

The researchers characterized these types of probes in detail, devices which could provide an estimation of the temperature with a never before seen precision. To do so, they combined thermodynamic tools with quantum metrology, which deals with ultra-precise measures in quantum systems.

The physicists searched to find the maximum precision which could be achieved in a real situation, in which measuring time could be very brief given unavoidable experimental limitations. In the research, they also observed that these thermometers could maintain a constant sensitivity in a wide range of temperatures by sacrificing some of their precision.

For the authors of the research, "finding a nanothermometer sensitive enough at this scale is a great step forward in the field of nanotechnology, with applications in biology, chemistry, physics and even in the diagnosis and treatment of diseases."

From Science Daily