May 2, 2015

New exoplanet too big for its star challenges ideas about how planets form

The Australian discovery of a strange exoplanet orbiting a small cool star 500 light years away is challenging ideas about how planets form.

"We have found a small star, with a giant planet the size of Jupiter, orbiting very closely," said researcher George Zhou from the Research School of Astrophysics and Astronomy at The Australian National University.

"It must have formed further out and migrated in, but our theories can't explain how this happened."

In the past two decades more than 1,800 extrasolar planets (or exoplanets) have been discovered outside our solar system orbiting around other stars.

The host star of the latest exoplanet, HATS-6, is classed as an M-dwarf, which is one of the most numerous types of stars in galaxy. Although they are common, M-dwarf stars are not well understood. Because they are cool they are also dim, making them difficult to study.

HATS-6 emits only one twentieth of the light of our sun. The giveaway that the faint star had a planet circling it was a dip in its brightness caused as the planet passed in front of the star, observed by small robotic telescopes including telescopes at the ANU Siding Spring Observatory.

To confirm the signal was a planet and not a blip in the system, Dr Bayliss called in help from one of the world's largest telescopes, the Magellan Telescope in Chile, and an amateur astronomer, T G Tan, who operates from his backyard in Perth.

"T G Tan has been really helpful on our projects. He was able to catch the transit of the planet from Perth, after it had set over our horizon," Mr Zhou said.

Read more at Science Daily

Medieval 'Witch Girl' Likely Just Suffered From Scurvy

A Medieval teenage girl found buried face-down last year in northern Italy suffered from scurvy and was rejected by her community, according to new study of her burial.

Dubbed by Italian media as "the witch girl," the skeleton was unearthed in September 2014 at the complex of San Calocero in Albenga on the Ligurian Riviera, by a team of the Pontifical Institute of Christian Archaeology at the Vatican.

The site, a burial ground on which a martyr church dedicated to San Calocero was built around the 5th and 6th centuries A.D., was completely abandoned in 1593.

"The girl lay in prone position in a tomb much deeper than the others. She was buried in an isolated area of the cemetery in front of the church," said archaeologist Stefano Roascio, the excavation director.

Like other deviant burials, in which the dead were buried with a brick in the mouth, nailed or staked to the ground, or even decapitated and dismembered, the prone burials aimed to humiliate the dead and impede the individual from rising from the grave.

Found with her hands placed on the pelvis and straight and parallel legs, the girl’s bones showed all signs of a severe anemia. Further analysis also determined she suffered from scurvy, a disorder caused by an insufficient intake of vitamin C.

The disease was most common among sailors in the 16th to 18th centuries who embarked on long voyages without enough foods with vitamin C and frequently died from the condition.

"Scurvy was diagnosed on the basis of cranial lesions which were the result of porotic hyperostosis," anthropologist Elena Dellù told Discovery News.

Found mostly in the bones of the cranial vault, porotic hyperostosis causes them to become spongy and the bone tissue porous. Examining the remains of the teenage girl, Dellù and colleagues found evident signs of the pathological condition on the external surface of the occipital bone, on the orbital roofs and on the greater wings of the sphenoid.

"Areas of these osteo productive lesions were also present near the dental sockets and on the palate, where some teeth had fallen probably due to weak blood vessels, also damaged by mastication," Dellù said.

In the anthropologic literature, porotic hyperostosis is mostly seen as evidence of iron deficiency anemia, but in this case specific clues indicate the girl was a scurvy victim.

"When it comes to anaemia, porotic hyperostosis normally concentrates on the internal surface of the skull and on the eye bony sockets. In case of scurvy we also find it on the palate and in the sphenoid," Dellù said.

Standing just under 5 feet tall, the young girl somehow scared the community.

Her pallor, associated to other scurvy symptoms such as mouth, leg and eye bleeding, corkscrew hair, protruding eyes, frog leg posture and possibly fainting and epileptic seizures, must have played a key role in her social rejection.

As she died, she was humiliated with the face down treatment, so that her soul, considered impure, would not come out to threaten the living.

"Any disease that people didn't understand may have caused them to bury someone in a deviant manner," Kristina Killgrove, biological anthropologist at the University of West Florida not involved in the research, told Discovery News.

Radio carbon dating revealed the girl died between the first half of 1400 and the beginning of 1500, a period of social and religious tensions which led to witch hunts and persecutions.

One of the most famous witch hunt manuals, the Malleus Maleficarum ("Hammer of the Witches") was published in 1484.

"In that climate, it is quite likely the young girl was considered a witch," Roascio and Dellù said.

Led by scientific director Philippe Pergola, professor of topography of the Orbis Christianus Antiquus at the Pontifical Institute of Archaeology, Roascio and Dellù will present their findings at an archaeological conference in Rome later this month.

The scurvy diagnosis makes the deviant burial finding even more interesting, according to Killgrove.

"There's not a whole lot of large-scale analysis done on ancient kids with scurvy, and the research we have tends to have been done on younger individuals between 3 and 7 years old," Killgrove said.

She noted that many of the scurvy cases are from places like England and parts of North America that didn't have access in the past to lots of vitamin-C-rich foods.

"It's interesting that this case is from Italy; after all, by the Middle Ages, citrus was well-known and well-circulated throughout Europe," Killgrove said.

Dellù believes the girl likely suffered from scurvy because of vitamin C malabsorption.

"Albenga is on the Ligurian coast and fresh foods rich in vitamin C were certainly available," she said.

Read more at Discovery News

May 1, 2015

Prehistoric Cockroach is Stuff of Nightmares

This new, prehistoric cockroach from 100 million years ago is the stuff of science-fiction nightmares. You know, if you ask me.

The insect, perfectly preserved in a piece of amber from Myanmar, or Burma, was closely related to praying mantises, according to the study reported in Geologica Carpathica.

The roach wasn’t all that huge for a dino-era bug — not even an inch long — but it was a fearsome nocturnal hunter nonetheless, reported Peter Vršanský from the Geological Institute in Bratislava, Slovakia, and Günter Bechly from the State Museum of Natural History in Stuttgart, Germany.

“The unique adaptations such as strongly elongated extremities and freely movable head on a long neck suggest that these animals were pursuit predators,” they said in their paper. reports that the insects lived in the early Cretaceous period, when several predatory cockroach-like lineages came into existence.

All of the roaches in those lineages are now extinct, except for one: the praying mantis, close cousins to cockroaches.

From Discovery News

Ancient Mayan City Built on Grid

An ancient Mayan city followed a unique grid pattern, providing evidence of a powerful ruler, archaeologists working at Nixtun-Ch’ich’ in Petén, Guatemala, have found.

The city, which contains flat-topped pyramids, was in use between roughly 600 B.C. and 300 B.C., a time when the first cities were being constructed in the area. No other city from the Maya world was planned using this grid design, researchers say. This city was “organized in a way we haven’t seen in other places,” said Timothy Pugh, a professor at Queens College in New York.

“It’s a top-down organization,” Pugh said. “Some sort of really, really, powerful ruler had to put this together.”

The ancient Mexican city of Teotihuacan also used a grid system. But that city is not considered to be Mayan, and so far archaeologists have found no connections between it and the one at Nixtun-Ch’ich’, Pugh said.

People living in the area have known of the Nixtun-Ch’ich’ site for a long time. Pugh started research on it in 1995 and has been concentrating on Mayan remains that date to a much later time period,long after the early city was abandoned. However, in the process of studying these later remains, his team has been able to map the early city and even excavate a bit of it.

Ceremonial route

From the mapping and excavations, Pugh can tell that the city’s main ceremonial route runs in an east-west line only 3 degrees off of true east. “You get about 15 buildings in an exact straight line — that’s the main ceremonial area,” he said. These 15 buildings included flat-topped pyramids that would have risen up to almost 100 feet (30 meters) high. Visitors would have climbed a series of steps to reach the temple structure at the top of each of these pyramids.

At the end of the ceremonial way, on the eastern edge of the city, is a “triadic” structure or group, which consists of pyramids and buildings that were constructed facing each other on a platform. Structures like this triadic group (the name comes from the three main pyramids or buildings in the group), have been found in other early Mayan cities.

The residential areas of the city were built to the north and south of the ceremonial route and were also packed into the city’s grid design, Pugh said.

From the excavations, archaeologists can tell that many of the city’s structures were decorated with shiny white plaster. “It was probably a very shiny city,” Pugh said.

The city’s orientation, facing almost directly east, would have helped people follow the movements of the sun, something that may have been of importance to their religion.

A wall made of earth and stone also protectedthe city, suggesting defense was also a concern of these Mayans.

Were the people miserable?

While the city was a sight to behold, its people might not have been happy with it, Pugh said.

“Most Mayan cities are nicely spread out. They have roads just like this, but they’re not gridded,” said Pugh, noting that in other Mayan cities, “the space is more open and less controlled.”

Cities in early Renaissance Europe that adopted rigid designs were often unpleasant places for their residents to live, Pugh said. It’s “very possible” that the residents of this early Mayan city “didn’t really enjoy living in such a controlled environment,” Pugh said.

Preserving the city

Archaeologists said they are thankful to the cattle ranchers who own the land the site is on and are protecting it against looters, Pugh said.

This location is one of the few Mayan sites in the area that hasn’t been looted, and that’s because the ranchers are “really protective, and they don’t want people messing with the Maya ruins,” Pugh said.

Read more at Discovery News

Woman Who Promoted Cancer-Curing Diet Admits Hoax

Australian Belle Gibson claimed in 2013 that a special diet, along with alternative medicine therapies, cured her terminal brain cancer. Shunning chemotherapy and other proven cancer treatments, she claimed to have healed herself through holistic medicine and proper nutrition.

Gibson started a wellness app based on her breakthrough discovery and wrote a cookbook with cancer-curing recipes. She became a rising star in the wellness and alternative medicine industry and won Cosmopolitan magazine's "Fun Fearless Female" award for social media.

However questions were raised about Gibson's story and cancer diagnosis in March after she told Australian News that "she believed she was misdiagnosed by a medical team in Germany -- by someone who she now thinks wasn't a medical doctor. She was now seeking treatment from a conventional medical team, which she declined to name."

This curious explanation only raised more questions, such as why she wouldn't reveal the name of the person who allegedly misdiagnosed her, and how she could not know whether or not that person was really a doctor. She eventually came clean.

In an interview last week Gibson admitted that she made up the whole story: she never had cancer in the first place, and her claim that a special diet or therapy cured her cancer was false. In an exclusive interview with The Australian Women's Weekly, Gibson was asked outright if she has, or has ever had cancer.  "No. None of it's true," she confessed.

Gibson is only the latest and highest-profile person to falsely claim to have been gravely ill. In 2009 a young Canadian woman named Ashley Kirilow made news for fighting bravely against breast, ovarian, brain, and liver cancers. She and her supporters raised over $20,000 for her treatments, but Kirilow eventually admitted that she never had cancer. She had shaved her head and eyebrows to fake the signs of chemotherapy, and had spent much of the money given to her on personal expenses. She was charged with fraud but spared jail time. She claimed she faked having cancer because she wanted attention from her family.

The Psychology of Factitious Disorders

Often cancer fakers do it for attention and sympathy, not because they are necessarily trying to scam people out of money. Some people really do have a disease -- not cancer but a mental illness known as a factitious disorder. People with this disorder pretend to have an illness (usually a terminal one) and often go to great lengths to maintain the hoax.

According to the latest edition of the American Psychiatric Association's "Diagnostic and Statistical Manual of Mental Disorders," the prevalence of factitious disorders is unknown. Many cases go undetected due to the deceptive nature of the patients. Often the person successfully ends their hoax by telling friends, family, and other supporters that they are cured, so their deception is never discovered.

The manual notes that "Among patients in hospital settings, it is estimated that about 1 percent of individuals have presentations that meet the criteria for factitious disorder. The course of factitious disorder is usually one of intermittent episodes."

In other words it's not merely one incident, such as a broken leg or a bout with the flu; potentially terminal illnesses such as cancer are often claimed by the patient, allowing them to carry on the deception for many months and even years.

In some cases the factitious disorder begins with a genuine health scare or preexisting condition that is then exaggerated over time. Patients will often go to great lengths to make their fake illness seem real to both doctors and supporters, including feigning seizures, manipulating lab results (for example by adding blood to a urine sample), and even physically injuring themselves.

It's not illegal to lie about having a disease, but if the person receives donations or free services under false pretenses, he or she may be charged with fraud.

Read more at Discovery News

Icy Europa Does Battle With Solar System's Most Hellish Moon

The astronomical juxtaposition couldn’t be any more stark: in the series of observations above, Jupiter’s icy moon Europa passes in front of Io, fellow Jovian moon, but also the most volcanically active place in the entire solar system.

Imaged by the huge Large Binocular Telescope (LBT), located in the Pinaleno Mountains, Ariz., this Jovian occultation on March 7 serves as a reminder as to the complex assortment of moons our solar system possesses.

On the one hand, we have an ice-encrusted Europa that has a sub-surface ocean with huge habitable potential for exo-marine life. But on the other, there’s a magma-covered Io convulsing with powerful volcanic eruptions. Though their differences are obvious, Europa’s habitable potential and Io’s volcanoes are driven by the same force: the tides of Jupiter.

As the closest Galilean moon in the Jupiter system with an eccentric orbit, Io bears the brunt of Jupiter’s tides, suffering huge tidal stresses as it travels around the massive gas giant. This creates an internal dynamo that keeps the 1,942 mile (3,636 kilometer) wide moon in a constantly-erupting state — the stress often becomes too great and huge explosions eject magma from the splitting crust. Orbiting further away, Europa (that is slightly smaller than Io with a diameter of 1,950 miles) also feels these tides, but the impact is far less dramatic.

Below the thick ice crust is an ocean that is kept in a liquid state by Jupiter’s tides compressing Europa’s core. But rather than generating the pressure-cooker that is Io, Europa has an internal heater that generates enough heat to keep its underground ocean liquid.

Loki, the Fire God

Now, by using the LBT’s twin 8.4 meter (27 feet) telescopes working in unison, never before seen features on Io’s surface pop into view.

A pooling, vast lake of magma is known to exist on Io, covering a region 124 miles wide. This feature, called “Loki” after the Norse god of fire and chaos, is known as a patera where a cooling lava crust floats atop molten rock. Periodically, the upper layers submerge into the magma, generating a surge in thermal emissions that can be observed from Earth.

Observing Io with the Large Binocular Telescope Interferometer, or LBTI, in infrared light, features in the Loki Patera have become easier to study.

“We combine the light from two very large mirrors coherently so that they become a single, extremely large mirror,” said Al Conrad, scientist at the Large Binocular Telescope Observatory, and lead author of the study published in the Astrophysical Journal. “In this way, for the first time we can measure the brightness coming from different regions within the lake.”

“While we have seen bright emissions — always one unresolved spot — ‘pop up’ at different locations in Loki Patera over the years,” added Imke de Pater, of the University of California, Berkeley, “these exquisite images from the LBTI show for the first time in ground-based images that emissions arise simultaneously from different sites in Loki Patera. This strongly suggests that the horseshoe-shaped feature is most likely an active overturning lava lake, as hypothesized in the past.”

“Two of the volcanic features are at newly active locations,” said Katherine de Kleer, also from the University of California, Berkeley. “They are located in a region called the Colchis Regio, where an enormous eruption took place just a few months earlier, and may represent the aftermath of that eruption. The high resolution of the LBTI allows us to resolve the residual activity in this region into specific active sites, which could be lava flows or nearby eruptions.”

Read more at Discovery News

The Disco Clam That Puts on a Mind-Bending Light Show

The dazzling display of the disco clam is almost certainly not fueled by cocaine.
Ah, disco. That lamentable fad turned the Bee Gees from a kinda cool, kinda psychedelic band into a conduit for polyester, all that damn color, roller skates, and strobe lights. And what’s left of it now? Disco Stu and John Travolta’s chest hair. Also, it has given scientists a shorthand way of describing a flashy little mollusk that lives in the Indo-Pacific and fires beautiful bands of light across its flesh. Technically it’s Ctenoides ales, but to the researchers who know it best, it’s the disco clam.

And unlike the ’70s, it is excellent.

For a long while, scientists reckoned the disco clam was throwing off bioluminescence. After all, the ocean is positively aglow with it—in the deep sea, perhaps 90 percent of animals produce some kind of light, either with their own chemical reactions or in cooperation with onboard bacteria. Down in the dark, that light does everything from confusing predators to attracting mates or prey. But the disco clam makes its home in shallower waters where bioluminescence isn’t as useful. And indeed, the clam’s brilliant flashes aren’t the work of bacteria, but instead are tricks of sunlight and some peculiar tissue.

Lindsey Dougherty, a biologist at UC Berkeley, was among the people who figured this light show out. She likens that strip of tissue to a scarf with one side covered in foil: “One side reflects all visible light, so it’s white. The other side only reflects long, low-energy wavelengths, which is why it appears red.” By rapidly furling and unfurling this tissue, as often as six times a second, the disco clam looks to be producing a mollusk-sized Laserium show, when in fact it’s simply reflecting available light at your eyeballs.

So how exactly is this “foil” side of the scarf so brilliantly white? Well, it turns out it’s covered with highly refractive nanospheres of silica. Silica is everywhere, from sand to shells to those little packets manufacturers put in shoe boxes and bags of food and such to absorb moisture. (By the way, they’re emblazoned with those serious warnings not to eat them not because silica is poisonous, but because apparently some folks need to be reminded that you can’t just go around eating whatever you feel like.)

The disco clam uses those tentacles to “sniff” the water, and as we’ll see in a bit, somehow drive mantis shrimp to try to get busy with it.
“The silica spheres are in a dense arrangement, and both their size and their density in the tissue are nearly optimized for scattering light,” says Dougherty. “They’re even better at this in blue-light conditions, which is what most of the ocean is composed of.” How exactly the disco clam is synthesizing this silica, Dougherty isn’t yet sure, but she’s working at it. The creature could be pulling the stuff from sand or straight from the water, or even consuming tiny plankton known as diatoms (clams are filter-feeders), whose shells are made of silica.

Go Into the Light

But why bother? Is the disco clam just trying to get laid, like so many dudes at Studio 54? Dougherty doesn’t think so. “All of the experiments we’ve done surrounding communication haven’t supported the idea,” she says. “The clams have about 40 eyes, but after studying their structure, it is unlikely they can actually perceive the flashing.” The intensity of the flashing, though, did seem to increase when Dougherty introduced plankton to their tank, suggesting the display may help the clam lure prey.

The clear dividing line between the clam’s reflective and non-reflective tissue.
But the flashing appears to increase—twice as much as normal—when a predator takes an interest, so maybe the display confuses villains. To find out if that was true, Dougherty introduced a disco clam to one of the ocean’s most ferocious pound-for-pound predators: the mantis shrimp. And hilarity ensued.

While the flashing may effectively drive off less tenacious predators, the mantis shrimp was having none of it. The mantis (which isn’t actually a shrimp, but a crustacean known as a stomatopod) comes equipped with two deployable club-claws, which it fires at its victims with such speed that it briefly heats the water to the temperature of the surface of the sun. It demolishes everything from clams to other crustaceans, blowing apart any shell that stands between it and flesh.

A mantis shrimp recoils from a disco clam moments before saying, “Eh, screw it. I’ll just hump the thing.”
And so it made its move on the clam, disco lights be damned, fiddling a bit with it and giving it a few taps. But something was amiss. The stomatopod suddenly recoiled and backed away, approached once more, and recoiled again. Another approach, and another recoil, before the predator began frantically cleaning its mouthparts and eventually going catatonic. When it recovered, it came in for one more attack before deciding to just try to mate with the clam instead. (A mating attempt actually happened four times, but Dougherty says she only included the first in the video so “as to not parade his failures.”)

The problem, Dougherty reckons, is that the clam’s mantle and flowing tentacles—which are chemosensory structures, similar to our noses—are packed with sulfur, which stomatopods don’t seem to take too kindly to. “We often see them go into a sort of catatonic state after interacting with the clams, so something suspicious is definitely going on,” she says. But when she gives the stomatopods flesh from inside the clam, the muscles and such, they don’t hesitate to dig in. There’s apparently just something different about the makeup of the mantle and tentacles. “This is the area where we found high amounts of sulfur,” Dougherty adds, “although we’re still working to figure out what type of sulfuric compound it is using mass-spectrometry.”

Read more at Wired Science

Apr 30, 2015

This is Where NASA's MESSENGER Mercury Mission Will Die

At 3:26:02 p.m. ET today, NASA’s MESSENGER spacecraft will careen into Mercury at a speed of 3.91 kilometers per second (over 8,700 miles per hour), adding a fresh crater to the small planet’s pockmarked surface. NASA estimates that, at that velocity, the small robotic probe will produce a crater some 52 feet (16 meters) across.

In this map of Mercury, created by data from MESSENGER’s Mercury Dual Imaging System (MDIS) and Mercury Laser Altimeter (MLA) instruments, the spacecraft’s final resting place has been rendered.

Currently, MESSENGER’s mission team predict the spacecraft will hit a ridge slightly to the northeast of the 250 mile-wide “Shakespeare” impact crater in the lower left of this image. The impact site is therefore likely going to be roughly in the center of this map.

The landscape is color-coded according to height, or relief. The reddest hues represent ridges around 2 miles higher than the surrounding landscape. It looks like, as MESSENGER zips across the landscape on its final orbital pass, these mountainous features will doom the probe.

After 4 years of stunning orbital operations about Mercury, MESSENGER finally ran out of fuel. Although mission engineers were able to slightly extend the mission, the time has come to say goodbye to the first ever robotic probe we’ve put into Mercury orbit as gravity takes over and forces this dramatic end to a historic mission to the inner solar system.

From Discovery News

Monkeys Show How to Perfectly Crack a Nut

Wild bearded capuchin monkeys could be the second best nut crackers in the animal kingdom, suggests new research on the small primates.

We’re in the number one spot, given all of our gadgets and machinery that can crack nuts, but the monkeys appear to be a close second, since they have their own tools and techniques for getting at the nutritious, tasty snack. (Chimpanzees could tie for second or be a close third, since they too are clever at this.)

A study in the journal Current Biology describes how the monkeys place uncracked nuts on an anvil, which is usually a piece of hardwood with a depression in it. Using a large rock, the monkeys then smash down on the nut. Next, they examine the nut, to see where the most vulnerable crack is, and then strategically hit that spot, which usually reveals the nutmeat.

This video shows how one capuchin monkey handled the task:

“Wild bearded capuchin monkeys dynamically modulate their strikes based on the outcome of the preceding strike while using stone hammers to crack nuts,” co-author Madhur Mangalam of the University of Georgia at Athens said in a press release. “Until now, this level of dexterity was not suspected of any monkey.”

It’s long been known that the monkeys were good nut crackers that used tools, but the process seemed to be trial and error.

Mangalam, lead author Dorothy Fragaszy and their team took a closer look by videotaping 14 capuchin monkeys cracking nuts. Analysis of the height and velocity of each and every strike found that the smashing was not random at all.

“It was a ‘eureka’ moment when we realized that the monkeys modulated the strikes systematically according to the condition of the nut following the preceding strike,” Mangalam said.

We take this skill for granted, but it’s a big deal when studying animals because the multi-step nut-cracking technique requires sophisticated brain processing. The monkeys must match their actions to the physical state of the nut.

Read more at Discovery News

Bat Wing Super Sensors Guide Its Acrobatic Flight

Bats are the only mammals capable of true powered flight, and now researchers have figured out how these clever creatures fly with such breathtaking precision and maneuverability.

Investigation of bat wings finds that they are equipped with highly sensitive touch sensors that respond to even the slightest changes in airflow, according to a paper published in the latest issue of the journal Cell Reports.

As lead author and Johns Hopkins neuroscientist Cynthia Moss shares in the following video, the findings could inspire new high tech aircraft:

“Until now no one had investigated the sensors on the bat’s wing, which allow it to serve as more than a propeller, a flipper, an airplane wing or any simple airfoil,” Moss said in a press release. “These findings can inform more broadly how organisms use touch to guide movement.”

Moss and her colleagues studied big brown bats (a common species found throughout North America), but they believe all bats possess the sensitive touch sensors on their wings. The sensors — two types of touch cells — are especially clustered at the base of tiny hairs on the bat wings. If you have a cat, very similar cells are located at the bottom of your feline’s whiskers.

Such systems are “innervated,” meaning nearby neurons (nerve cells) are connected to the spinal cord, which in turn is connected to the brain.

What’s remarkable about bats is that the nerve cells in wing skin are connected to the lower parts of the bat’s spinal cord, which normally only connect with an animal’s trunk. The researchers expected that the nerve cells would connect much higher on the bat’s spinal cord, closer to where the wings are.

As a result of this unexpected configuration, the entire body of a bat is primed for flight.

Here’s how the system basically works: tiny hairs on the wings detect everything from nearly imperceptible wafts of air to major gusts. The nerve cells at the base of the hairs send that information over to the spinal cord, which then transmits the info to the bat’s brain and trunk region.

All of this happens repeatedly in split second time, enabling the bat to very quickly make adjustments to its flight path.

Read more at Discovery News

Stone Age People Hooked Eels Like Modern Fishermen

Archaeologists in southern Denmark have found evidence showing that Stone Age people fished eels much like modern people, using three-pronged spears with a center point for spearing fish.

The clue, a fragmented fishing spear, known as a leister, was unearthed during an archaeological survey for the construction of the Femern Belt link, an immersed tunnel that will connect the German island of Fehmarn with the Danish island of Lolland.

"It was found obliquely embedded in the seafloor and must have been lost during fishing at some point in the Neolithic," Line Marie Olesen, archaeologist at the Museum Lolland-Falster, told Discovery News.

"The finding is remarkable as it shows both lateral prongs in doubtless association with a central bone point," she added.

The association between lateral prongs and bone point has long been presumed, but until now was never documented.

"In the past only a large number of individual leister prongs and bone points was found," Søren Anker Sørensen, an archaeologist specializing in mesolithic research, said.

A relatively well preserved spear, where parts of both of the lateral prongs had been preserved along with a piece of the shaft to which it was tied, was first discovered on the Danish Baltic Sea island of Ærø by diving amateur archaeologists some 40 years ago. But the piece did not have a centered point, as in modern spears.

Thus archaeologists have long wondered whether prehistoric fishing spears could work without such a point.

The new find provided the answer. Although the string winding and the shaft were missing, the position of spear's prongs and bone point in relation to each other indicated they belonged to the same spear that had broken off.

"It tells us, that in some cases at least, the leisters were equipped with a bone point much like present day eel leisters, which implies that the fishing of eel in that respect has not changed much," Olesen said.

Olesen and colleagues are now trying to precisely date the fishing tool.

"We have not yet obtained a radio carbon date of the leister. It could be middle Neolithic or late Neolithic alike and maybe even younger. From one of the other sites in the lagoon we have an individual leister prong, which is dated to the late Neolithic," Olesen said.

In the Late Stone Age, the area east of present-day Rødbyhavn where the fishing tool was found, featured two lagoons, and a 65-foot-wide belt of stones scattered in a layer of sand and gravel along the coast.

"The stone belt is actually the old coast, where it was to be found at approximately 3000 B.C.," Olesen said.

Immediately south of the stones, the archaeologists found a wattle fence which originated from one of the fixed gill nets on stakes that Stone Age fishermen set up close to the coast.

Stretching across about 82 feet and forming a U that opened towards the lagoon, the wattle fence

"Whether the gill net was originally placed on the site, or whether it had washed in from the sea or been brought in for repairs or maintenance is still uncertain," Olesen said.

According to the archaeologists, the relatively complex structure might indicate that its function was different from the more crude fishing weirs that are known in the area.

Last year the excavation work at the site yielded 5,000-year-old footprints alongside a system of fishing weirs, revealing how Stone Age people made strenuous attempts to cope with the destructive forces of the sea.

Read more at Discovery News

Sun's Beautiful Magnetism Captured in Stunning Eclipse Photo

When you block out the glare of the sun, usually invisible — and beautiful — phenomena pop into view. So when the moon conveniently slid across the face of our nearest star last month during a total eclipse, solar astronomers made sure they were in the right place at the right time.

And that place just happened to be one of the coldest and most extreme environments on the planet: Svalbard.

In this stunning photograph of totality, beautiful lines appear to stretch out from the moon’s edges. In fact, those lines highlight the magnetic structure of the sun’s corona that would normally be drowned-out by sunlight. This observation was made by a team of astronomers headed by Shadia Habbal of the University of Hawaii at Manoa who viewed the eclipse at the town of Longyearbyen on the island of Spitsbergen in the Svalbard archipelago.

Located deep within the Arctic Circle, the international team, called the Solar Wind Sherpas, braved –4 degrees Fahrenheit (–20 Celsius) and polar bears to get this view, but the effort was worth it.

Using specialist filters on digital SLR cameras located in two locations (to minimize the chance of bad weather hindering their view), the researchers were able to detect the light emitted by specific iron ions contained within the solar atmosphere — the corona. Also, using a dual-channel imaging spectrograph, the motions of these ions could be detected, providing an invaluable measurement of the depths of the corona. As the corona is a magnetically-dominated region, a spectropolarimeter was used to measure the coronal magnetic field.

The results of this expedition are being presented today (April 30) by the Solar Wind Sherpas at the Triennial Earth-Sun Summit in Indianapolis, Ind.

This observation is special to me personally, having lived in Longyearbyen for 5 months in 2002 when completing my astrophysics masters degree. Svalbard is a hothouse of scientific opportunity and researchers from all disciplines flock to the isolated islands to study its unique biodiversity and geology. But my research didn’t focus on the islands themselves, it focused on the sun’s interaction with the Earth’s magnetic field and upper polar atmosphere, and the stunning aurorae this complex relationship generates.

My time on Svalbard inspired me to take my new-found passion for space weather to the next level, deciding to embark on a PhD in coronal physics that year. And interestingly, Shadia Habbal was one of my two postgraduate supervisors, with solar physicist Xing Li (at Aberystwyth University, Wales).

Read more at Discovery News

Spacecraft Set for Death Plunge Into Mercury

The MESSENGER spacecraft -- which stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging -- will end its run and dive into Mercury at 3:26:02 p.m. ET today, the U.S. space agency said.

The spacecraft is expected to crash onto the planet's surface at a searing 8,750 miles per hour -- fast enough to carve out a crater 52 feet wide.

Its mission was initially only supposed to last one year, but since it was operating well and returning interesting data and discoveries, scientists extended its life as long as they could.

MESSENGER's key finding, in 2012, was a thick coat of ice in Mercury's polar regions, providing "compelling support for the hypothesis that Mercury harbors abundant frozen water and other volatile materials in its permanently shadowed polar craters," NASA said.

"For the first time, scientists began seeing clearly a chapter in the story of how the inner planets, including Earth, acquired water and some of the chemical building blocks for life," the agency said in a statement.

Scientists believe that the closest planet to the sun likely got its water when comets and volatile-rich asteroids made impact, sometime in history.

MESSENGER was launched in 2004 and traveled for more than six years before it finally began orbiting Mercury on March 18, 2011.

Once the unmanned probe runs out of propellant, it will no longer be able to fight the downward push of the Sun's gravity and will fall, striking the planet at more than 8,750 miles per hour (3.91 kilometers per second) on the side of the planet facing away from Earth.

Read more at Discovery News

Apr 29, 2015

Bat-Like, Pigeon-Sized Dino Soared Over China

A dinosaur with bat-like wings once soared through the skies of what is now China,

The Jurassic dinosaur, named Yi qi, has the shortest name ever given to a dino: Yi qi, pronounced "ee chee," means "strange wing." It also appears to be the earliest known flying non-avian dinosaur. At 160 million years old, it is older than the first known birds, such as Archaeopteryx.

"This is the most unexpected discovery I have ever made, even though I have found a few really bizarre dinosaurs in my career," noted paleontologist Xu Xing of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing told Discovery News.

"I know the complexity of the dino-bird transition, but this new find still shocks me," added Xu, who is the lead author of the study, published in the journal Nature. "It demonstrates how extreme the experimentation for dinosaurs to get in air is."

He and his colleagues unearthed the remains for Yi qi at Hebei Province in China. At first, the scientists puzzled over rod-like bones that extended from each wrist of the tiny dinosaur that weighed about the same as a modern pigeon. Colleagues joked that the dino used the bones as ski poles or giant chopsticks.

Co-author Corwin Sullivan, a Canadian paleontologist now based at the IVPP, determined their real purpose after he pored over scientific literature on flying and gliding animals for a different project.

Sullivan recalled that he "came across a paragraph in a textbook that said flying squirrels have a strut of cartilage attached to either the wrist or elbow to help support the flight membrane. I immediately thought, wait a minute--that sounds familiar!"

Further investigation of Yi qi's remains uncovered patches of membranous tissue that covered its wings. While the dinosaur did have feathers, they were more like hairs, bristles or streamers, and would not have been capable of forming good aerodynamic surfaces, Sullivan said.

Given the dinosaur's bat-like wings, "Yi qui was mainly gliding, perhaps in combination with a bit of awkward flapping," he added.

The researchers believe Yi qi was a scansoriopterygid, referring to a group of dinosaurs only known from China that were closely related to primitive birds, such as the aforementioned Archaeopteryx. Although the dinosaur shared traits with bats, it wasn't related to them, since bats are mammals. It therefore represents a striking example of convergent evolution.

Yi qi had other noteworthy characteristics, aside from its unusual wings.

Sullivan said that its arms were proportionally very long, with each arm ending in a hand that had three clawed fingers. One of the fingers was very elongated, with it and the other fingers helping to support the flight membrane.

Its head was small, but equipped with tiny peg-like teeth, which it probably used to eat prey such as insects, small mammals and lizards. What is now Hebei Province, during the Jurassic, featured a verdant and forested environment near a lake.

As for what might have eaten Yi qi, Xu said, "I would not be surprised to see some primitive tyrannosaurs around."

Read more at Discovery News

Monkey Creates 6-Word 'Language'

Male species of a West African monkey communicate using at least these six main sounds: boom-boom, krak, krak-oo, hok, hok-oo and wak-oo.

Key to the communication by the male Campbell's monkey is the suffix "oo," according to a new study, which is published in the latest issue of the Proceedings of the Royal Society B.

By adding that sound to the end of their calls, the male monkeys have created a surprisingly rich "vocabulary" that males and females of their own kind, as well as a related species of monkey, understand.

The study confirms prior suspected translations of the calls. For example, "krak" means leopard, while "krak-oo" refers to other non-leopard threats, such as falling branches. "Boom-boom-krak-oo" can roughly translate to, "Watch out for that falling tree branch."

"Several aspects of communication in Campbell's monkeys allow us to draw parallels with human language," lead author Camille Coye, a researcher at the University of St. Andrews, told Discovery News.

For the study, she and her team broadcast actual and artificially modified male Campbell's monkey calls to 42 male and female members of a related species: Diana monkeys. The latter's vocal responses showed that they understood the calls and replied in predicted ways.

They freaked out after hearing "krak," for example, and remained on alert as they do after seeing a leopard.

In addition to "krak," other root calls are the "boom," as well as hok (crowned eagle) and wak, with a meaning that hasn't yet been confirmed. These are root "words" that the monkeys vary with the "oo" suffix. "Hok" by itself, for example, refers to the bird of prey, but "boom boom hok-oo hok-oo" appears to signify claiming of territory.

While the researchers are still reserving the word "language" and related terms for humans, they have identified five ways in which Campbell's monkey calls are similar to our way of communicating.

First, it's now known that these monkeys engage in conversations. "The call exchanges between individuals follow a conversational rule," Coye explained. "An individual gives a call and then, after a short silence of less than one second, another answers, just as we do when discussing with others."

Secondly, there is evidence for "vocal convergence," or development of something akin to accents and other connected ways of expression among monkeys that have strong relationships with each other.

Further, the monkey calls have distinct meanings, and suffixes are added to change those meanings. Finally, the calls include what's known as "proto-syntax," meaning that the order of the calls and suffixes is significant. For example, "oo-krak" would be just as puzzling to a monkey as "ed-educate" would be to people who might have meant to say "educated."

In a separate study led by researcher Karim Ouattara, who also was a co-author of the new paper, the scientists concluded that "the Campbell's monkey call system may be the most complex example of proto-syntax in animal communication known to date."

Aside from learning more about our fellow primates, Coye said that the goal of this and similar studies "is to understand which abilities existed before language, abilities which may have been the ground of language evolution."

Read more at Discovery News

These Are the Amazon Trees That Keep the Planet Cool

Within the botanical menagerie that makes up the Amazon rainforest, which is so important it’s frequently dubbed the “lungs of the planet,” scientists have pinpointed a small number of tree species that are doing the heaviest breathing as they help to slow global warming.

Their discovery — that 182 species store half the rainforest’s woodbound carbon — suggests that the future of the world’s climate, and the contours of its coastal areas, are intertwined with the fate of this small portion of an estimated 16,000 Amazonian tree species.

Despite ongoing logging and recent drought, the Amazon is home to perhaps a sixth of the carbon stored in living vegetation the world over, helping to keep levels of climate-changing carbon dioxide down in the atmosphere.

“The Amazon is a massively important carbon stock, and it’s currently acting as a carbon sink,” Leeds University’sSophie Fauset, who led the research, said. “What we’re trying to do is increase our understanding of where this carbon is going; which trees are storing it.”

The findings were published Tuesday in Nature Communications following analysis of data covering 530 areas. The most common tree identified in the study, a variety of palm known to scientists as Iriartea, was also found to hold the most carbon. But the other 181 species identified as the most important for carbon storage weren’t necessarily the most common species in the rainforest. They were species that shared combinations of important features, being relatively abundant, long-living and large-growing.

“There are a few species that seem to grow big — and those are the ones you’d want to emphasize in conservation,” said University of California at Berkeley forest ecology professor John Battles, who was not involved with the research. “If you were managing these forests, you would leave these trees.”

One of the most carbon-hungry types of trees identified in the study was the Brazil nut tree, which grows trunks that can easily exceed a height of 100 feet. In a list ranking species by the total number of individual trees growing within the 530 studied plots, Brazil nut trees ranked 243rd. In terms of total growth and productivity, by contrast, they ranked fourth overall, and they were found to contain 1.3 percent of the forest’s carbon.

“The default assumption would be, I think, that given the enormous biological diversity of tropical forests, carbon cycling would be more equitably distributed among plant species,” National Center for Atmospheric Research scientist Rosie Fisher, who wasn’t involved with the study, said. “This discovery overturns that paradigm.”

Fisher said she would be “hesitant to suggest the most obvious idea — that we could store lots of carbon by planting these very large species,” because so little is known about how sensitive they are to the types of droughts and fires that are projected to become more common in the future, nor whether they would thrive in managed forests.

Read more at Discovery News

Star 'Mass Grave' Surrounds Our Galaxy's Black Hole

Astronomers have zoomed into an X-ray emission region immediately surrounding our galaxy’s supermassive black hole, gaining the highest X-ray resolution view to date, and it looks like they’ve stumbled on a mysterious place where stars go to die.

Sagittarius A*, or Sgr A*, is the enigmatic compact radio source surrounding the supermassive black hole in the center of our galaxy. The black hole, which has a mass 4 million times that of our sun, dominates this region with its extreme gravitational well. Many efforts have been carried out in an attempt to understand the population of stars and other stellar phenomena in the immediate vicinity of Sgr A*, but resolving features from such an extreme environment at a distance of 25,000 light-years is not easy.

Through measurements of X-ray spectra from the black hole’s neighborhood, however, astronomers are gradually adding some detail to Sgr A*’s landscape and in new research published in the journal Nature, it seems there’s a strange population of ‘dead’ stars accumulated in the black hole’s shadow.

Using data from NASA’s NuSTAR X-ray space telescope, high-energy physicist Kerstin Perez, of Haverford College, PA, and Columbia University, New York, and her team have been able to better resolve the signatures of various X-ray emissions and it appears that some sources are consistent with a large population of white dwarf stars.

White dwarfs are the stellar remnants of larger stars that have run out of hydrogen fuel and died. Our sun, for example, after exhausting its fuel in about 5 billion years, will puff up into a huge red giant and then rip itself to shreds, expelling huge quantities of solar matter through violent winds. This will cause chaos in the solar system, destroying planets and producing a vast planetary nebula of hot gas. In the center of all the mess will be a white, glowing ball of degenerate matter, a white dwarf.

From previous studies of white dwarfs elsewhere in our galaxy, astronomers have a good idea as to their X-ray emission profiles, so when studying the few parsecs surrounding Sgr A*, Perez’s team were surprised to find an abundance of white dwarf-like emissions. In short, it looks like they stumbled on a puzzling “mass grave” of dead stars.

“The Galactic Center region is dense with X-ray-emitting objects; it contains the supernova remnant Sagittarius (Sgr) A East, the colliding stellar winds surrounding Sgr A*, the hot plasma of the Sgr A East plume, dozens of magnetic X-ray filaments, and thousands of resolved and unresolved point sources that constitute the Galactic ridge X-ray emission,” the researchers write in their Nature Letters paper.

"Almost anything that can emit X-rays is in the galactic center," said Perez in a NASA Jet Propulsion Laboratory news release. "The area is crowded with low-energy X-ray sources, but their emission is very faint when you examine it at the energies that NuSTAR observes, so the new signal stands out."

Within this mess of X-rays are emissions that aren’t associated with other known emission sources, such as dense molecular gas or dust.

“A natural explanation for our emission is provided by the intermediate polar (a type of cataclysmic variable binary star), which has the hardest spectrum of all accreting magnetic white dwarfs.”

There are some other possible explanations — such as an anomalous population of pulsars (rapidly-spinning neutron stars) — but the most likely source appears to be a large number of white dwarfs orbiting within 10 parsecs (33 light-years) of our Milky Way’s supermassive black hole. The X-ray emission originates from these white dwarfs 'feeding' off binary partners' stellar gas.

If they are white dwarf stars, why are they there? The researchers aren’t too sure, but these observations provide a valuable insight to the stellar dynamics in close proximity to a galaxy’s supermassive black hole.

Read more at Discovery News

Apr 28, 2015

Transparent light shutters: Windows that act like an LCD screen

The secret desire of urban daydreamers staring out their office windows at the sad brick walls of the building opposite them may soon be answered thanks to transparent light shutters developed by a group of researchers at Pusan National University in South Korea.

A novel liquid crystal technology allows displays to flip between transparent and opaque states -- hypothetically letting you switch your view in less than a millisecond from urban decay to the Chesapeake Bay. Their work appears this week in the journal AIP Advances, from AIP Publishing.

The idea of transparent displays has been around for a few years, but actually creating them from conventional organic light-emitting diodes has proven difficult.

"The transparent part is continuously open to the background," said Tae-Hoon Yoon, the group's primary investigator. "As a result, they exhibit poor visibility."

Light shutters, which use liquid crystals that can be switched between transparent and opaque states by scattering or absorbing the incident light, are one proposed solution to these obstacles, but they come with their own set of problems.

While they do increase the visibility of the displays, light shutters based on scattering can't provide black color, and light shutters based on absorption can't completely block the background. They aren't particularly energy-efficient either, requiring a continuous flow of power in order to maintain their transparent 'window' state when not in use. As a final nail in the coffin, they suffer from a frustrating response time to power on and off.

Tae-Hoon Yoon's group's new design remedies all of these problems by using scattering and absorption simultaneously. To do this, Yoon's group fabricated polymer-networked liquid crystals cells doped with dichroic dyes.

In their design, the polymer network structure scatters incident, or oncoming light, which is then absorbed by the dichroic dyes. The light shutters use a parallel pattern of electrodes located above and below the vertically aligned liquid crystals.

When an electric field is applied through the electrodes, the axes of the dye molecules are aligned with that of oncoming light, allowing them to absorb and scatter it. This effectively negates the light coming at the screen from its backside, rendering the display opaque -- and the screen's images fully visible.

"The incident light is absorbed, but we can still see through the background with reduced light intensity," Yoon said.

Read more at Science Daily

Mathematics reveals how fluid flow affects bacteria

Researchers from the University of Liverpool have used mathematical equations to shed new light on how flowing fluid hinders the movement of bacteria in their search for food.

Many bacteria are mobile and inhabit a variety of dynamic fluid environments: from turbulent oceans to medical devices such as catheters.

Mathematicians from the Universities of Liverpool and Manchester developed a new set of equations to study how flowing fluid affected the movement of bacteria and how the swimming behaviour of the bacteria themselves affected their travel.

Bacteria can change their swimming direction when they encounter a chemical cue which allows them to move towards preferable environments and away from harmful chemicals.

Since the first attempts at classifying bacteria in the 17th century, shape has been an important feature, yet it is still not fully understood how shape affects the ability of bacteria to navigate their environments.

Slender bacteria

The equations showed, in regions where there are strong gradients in the fluid velocity (high shear), that the majority of slender bacteria (rod-shaped bacteria), but not spherical bacteria, swim in the same direction in which the fluid is flowing.

This means that slender bacteria get trapped in these high shear regions because it is too difficult for them to swim against the direction of the flow.

This may negatively affect their ability to find food because they are no longer able to perform an efficient search strategy when trapped. Conversely it may positively affect their ability to colonise surfaces because they may become trapped in regions close to surfaces.

Dr Rachel Bearon, from the Department of Mathematical Sciences and lead author on the paper, said: "Our findings build on recent and surprising research which found that moving water impeded bacteria movement, which isn't what you would expect.

"Using a new set of mathematical equations we were able to show that this happened because of the interplay between swimming behaviour, bacterial shape, and fluid dynamics.

Read more at Science Daily

When Did the Universe Flood With Water?

By studying ancient molecular clouds in our galaxy, astronomers have revealed that the universe’s reservoir of water likely appeared much earlier than thought — only a billion years after the Big Bang.

The challenge facing water formation, a molecule composed of two hydrogen atoms and an oxygen atom, is that any element heavier than helium had to have been formed in the cores of stars and not by the Big Bang itself.

The earliest stars would have taken some time to form, mature and die, so elements as heavy as oxygen would have emerged from its furnace through stellar winds and supernovae some time later. With this delay in mind, and the time it would have taken for these oxygen atoms to disperse throughout the cosmos and attach to hydrogen, astronomers have long thought that H2O appeared throughout the universe rather late.

But according to new research published in the journal Astrophysical Journal Letters, this may not have been the case. In fact, there was likely an abundance of water only a billion years after the universe was born.

“We looked at the chemistry within young molecular clouds containing a thousand times less oxygen than our sun. To our surprise, we found we can get as much water vapor as we see in our own galaxy,” said Avi Loeb, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics (CfA), Mass.

The first stars to pop into existence around 100 million years after the Big Bang were massive and unstable. They quickly burnt through their supply of hydrogen fuel, exploding as supernovae. These stellar explosions seeded the universe with heavier elements. The result was pockets of gas rich in heavy elements — but “rich” is a matter of perspective; compared with the oxygen content of our modern galaxy, these early gas clouds were very oxygen-poor.

But despite the low levels of oxygen, the environment at that time would have been ideal to “cook up” water molecules. Temperatures of 80 degrees Fahrenheit (300 Kelvin) would have been perfect to combine what oxygen that was available to the abundant hydrogen atoms.

“These temperatures are likely because the universe then was warmer than today and the gas was unable to cool effectively,” said co-investigator Shmuel Bialy of Tel Aviv University.

“The glow of the cosmic microwave background was hotter, and gas densities were higher,” added Amiel Sternberg, a co-author also from Tel Aviv University.

Read more at Discovery News

Signs of Subsurface 'Alien' Life Found in Antarctica

An airborne survey of a presumably dry Antarctic valley revealed a stunning and unexpected interconnected subsurface briny aquifer deep beneath the frozen tundra, a finding that not only has implications for understanding extreme habitats for life on Earth, but the potential for life elsewhere in the solar system, particularly Mars.

The briny liquid -- about twice as salty as seawater -- was discovered about 1,000 feet underground in a region known as Taylor Valley. The aquifer is widespread, extending from the Ross Sea’s McMurdo Sound more than 11 miles into the eastern part of valley. A second system was found connecting Taylor Glacier with the ice-cover Lake Bonney.

But the survey, which covered 114 square miles, may have just uncovered the proverbial tip of the iceberg.

“It suggests that this ecosystem is extensive and connected. There could be a very, very large subsurface habitable environment throughout the Antarctic regions,” Ross Virginia, an ecosystem ecologist at Dartmouth College, told Discovery News.

“One of the big questions now is is this finding regionally specific, or are there many locations in Antarctica where we have conditions that have created these subsurface environments for life,” Ross Virginia, an ecosystem ecologist at Dartmouth College, told Discovery News.

In a paper published in Nature Communications, lead researcher Jill Mikucki, with the University of Tennessee, and colleagues note that while few subsurface aquatic environments have been sampled, all were found to be teeming with life.

Earlier this month, scientists using temperature and humidity measurements taken by NASA’s Mars rover Curiosity realized that conditions were right for salty liquid water to exist close to the planet’s surface. On Mars, perchlorates in the soil lower the freezing temperature of water, a different chemistry than what exists in Antarctica.

“The subsurface aquifers that we’ve been looking at in the (Antarctic) are potential analogs to understanding Mars systems,” Mikucki told Discovery News. “We still have a lot to learn about these dry valley aquifer systems, but they appear to be related to climate changes.”

Curiosity and other missions have turned up ample evidence that Mars, which is now a cold and dry desert, was once flush with water. What happened to the water is still a mystery.

To survey the Antarctic subsurface, scientists used an instrument known as transient electromagnetic sensor to generate a strong, ground-penetrating electromagnetic field. Liquids – particularly salty liquids – are more conductive than rock, soil and ice, giving scientists to ability to differentiate subsurface materials.

Read more at Discovery News

Apr 27, 2015

This T. rex-Like Dino Was Vegetarian

A seven-year-old boy has just discovered a new dinosaur that was closely related to notorious carnivore Tyrannosaurus rex, but surprisingly ate a meat-free diet.

The 145-million-year-old dinosaur, Chilesaurus diegosuarezi, has been nicknamed "The Platypus" because of its extremely bizarre anatomy that was a mish-mash of features associated with huge carnivores, gigantic herbivores and nearly everything in between. It is described in the latest issue of the journal Nature.

The lifestyle of "The Platypus" contrasted with that of its relative, T. rex, which could likely rip the head off of other animals with a single bite.

"Chilesaurus probably fed upon ferns, araucarians, bennetitaleans, and podocarps -- all of which were plants that were abundant at the end of the Jurassic," lead author Fernando Novas of the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires told Discovery News.

Diego Suárez, the son of two of Novas' co-authors, Rita de la Cruz and Manuel Suárez, stumbled upon the fossils of Chilesaurus while he and his sister Macarena were looking for decorative stones at the Toqui Formation in Aysén, south of Chilean Patagonia.

The researchers explored the area further and excavated even more fossils. At first they thought the bones belonged to multiple species, but they found four complete Chilesaurus skeletons, providing strong evidence that the combination of unique anatomical features belonged to a single species.

The dinosaur grew up to 10 feet long and was a member of the typically two-legged theropod group of dinos that included some of the world's most iconic meat eaters, such as Velociraptor and Carnotaurus, in addition to Tyrannosaurus.

Instead of chomping into meat, Chilesaurus could munch on plants either by directly accessing them via its long neck or by stuffing them into its horny-beaked mouth with its short T-rex-resembling forelimbs. Its leaf-shaped teeth could then chew the plant materials into a swallow-ready mass.

Novas and his team believe that the earliest theropods started off as carnivores before some evolved towards an all-plant diet. Chilesaurus wasn't the only such herbivore. Limusaurus also veered toward veggies, probably due to ecological pressures and because plants were likely abundant in its environment.

Other animals in Chilesaurus' ecosystem included small, meat-eating crocodiles and extremely large plant-eating dinosaurs, such as 50-foot-long Diplodocus.

While some theropod dinosaurs evolved into birds, Chilesaurus and its related plant-eating dino relatives experienced another fate.

"Theropods that evolved into herbivores finally went extinct without leaving descendants that switched into carnivores again," Novas said.

Read more at Discovery News

8-Limbed Baby Touted as Reincarnated Indian God

A baby born in India with a parasitic twin last week is being touted as a god. Some locals believe he is the reincarnation of the Hindu deity Ganesha who has multiple arms and an elephant head.

As news spread about this as-yet unnamed boy, the faithful have begun making their way across India to see and revere the infant.

Ganesha is associated with success and good fortune, making him one of the most widely-worshipped deities in the Hindu pantheon. In fact the child’s resemblance to Ganesha is somewhat tenuous; the elephant-headed god has six limbs, not eight, and is typically depicted with four arms and two legs, while the boy has four arms and four legs.

Nonetheless the similarity is close enough, and this is not the first time that an eight-limbed baby has been claimed as a reincarnated Hindu god; in fact it happened as recently as November 2014.

Just last month a girl was born with a facial deformity that resembled a small elephant trunk, leading some to call her “Ganesha’s Wife” and suggest that she, too, is divine.

The “Times of India” reported that local interest in seeing the girl created such a frenzy that peace officers “had to arrive at the locality to keep the crowd under control. One of the officers said they wanted to ensure there were no casualties. ‘The house is small and has a staircase leading to the newborn baby’s room. We wanted to make sure that people don’t rush in at the same time,’ he said. Back in the small room where the baby lay, people formed a queue for the ‘Devi Darshan.” Sixty year-old Omvati, the baby’s grandmother, is excited like the rest. She says she’s never seen so many people jostling with each other to enter her house.”

The baby’s father, a vegetable seller who earns less than $5 per day, was delighted with the birth defect and said he hoped that the child would bring him good luck.

For most Indian children the deformity is anything but a sign of providence; a story on the “Medical Daily” web site noted that the defect was likely the result of chemical contamination: Doctors say the deformity “is most likely triggered by a gene mutation from malnutrition and heavy pollution levels in the area.”

Though modern medicine can explain the deformity, the idea that such a baby may be holy is ancient. In fact in Medieval times children born with deformities were often believed to have been “touched by God” and thus partially divine.

Cultural Explanations for Birth Defects

For most of human history (and long before genetics were understood) birth defects were blamed either on the gods or on the mother. The most common belief was that physical deformities, ranging from extra arms and legs to unusual or prominent birthmarks, were caused by the emotional state of the mother during pregnancy. This notion, fueled in part by the sexist stereotype of the emotionally fragile nature of the “weaker sex,” held that anything that startled or frightened a pregnant woman could be imprinted on her fetus. These “maternal impressions,” as they were called, could take many forms but were most often associated with animal encounters.

Jan Bondeson, author of “A Cabinet of Medical Curiosities,” notes that if an expectant mother “saw a duck, the child might be born with webbed hands and feet; if she was frightened by a snake, the baby might have staring eyes and a flickering tongue; if she kicked a pig, the child might speak in grunts through its nose…The belief in maternal impressions is of great antiquity; it has been traced to ancient India and China, as well as to early African and Asian folklore, to the old Japanese and to the Eskimos.”

In fact it can even be found in the Bible; Genesis 30 describes an experiment in which animals’ fur color was changed by the color of the trees where they drank and mated. “Many sixteenth- and seventeenth-century medical scientists and biologists of great repute embraced the maternal impression creed,” Bondeson writes, noting that “Maternal impressions were of common occurrence all over Europe” during the 1500s and 1600s.

By the 1800s the idea of maternal impressions fell out of favor, though the belief remains in some places into modern times. In their book “A Dictionary of Superstitions” Iona Opie and Moira Tatem recount a story told by a midwife from 1939 about “how a patient of hers brought forth a child with a wing instead of an arm because the mother had previously been frightened by a bird.”

Read more at Discovery News

Orchids' Lips Evolved to Lure Pollinators

Orchids, like humans, use their lips to attract and entice others, and now new research finds that intense competition underlies their formation and constant changes.

Two competing groups of proteins are engaged in an evolutionary war that helps to explain why orchids are so beguiling and come in many different shapes and sizes, according to a new study published in the latest issue of the journal Nature Plants.

Co-author Chang-Hsien Yang and his colleagues found that the protein complex "L" (for lip) and the protein complex "SP" (for standard petals) of orchids compete to promote the different shapes. If the proteins for lip formation win out, then the orchid will develop a big, prominent lip. If the competing complex wins, then flowers will develop where all of the petals look about the same. A mixture of the two creates a less obvious lip and countless variations.

An orchid lip is important because "it acts as a landing pad or serves as a platform for potential pollinators, such as insects, moths and butterflies," Yang, a professor in the Graduate Institute of Biotechnology at the National Chung Hsing University, told Discovery News.

"The lip also acts as the main pollinator attractant by employing visual, fragrance and tactile cues," Yang added. "All of these are important for giving orchids a great evolutionary advantage by promoting reproduction."

It's not hard to figure out that this bee orchid hopes to attract bees and other pollinators. When seen from above, it looks like a bee-shaped puppet.

The "come hither" look of orchids, such as this member of the genus Phalaenopsis, ties with their sexy appearance.

Barbara Gravendeel, who co-authored a Nature Plants "News & Views" piece about the latest orchid research, told Discovery News that while bees are very intelligent insects, they really do think that they are mating with another bee when they land on many orchids.

The mistake is understandable, considering that many orchids smell, feel and look like bee bodies.

The new research adds to the growing body of evidence that plants can be clever and develop effective, flexible survival strategies, even though they do not possess a brain. Here, an orchid from the Serapia genus is being pollinated by a bee, which believes he is having sex with another bee.

Gravendeel who is chair of the Biodiversity Department at the University of Applied Sciences, Leiden, explained that many orchids always flower at the beginning of the bee mating season, bursting open a week before female bees emerge above ground.

"Only un-experienced male bees that emerge a bit earlier than the females are fooled into mating with orchid flowers that look, smell and feel like female bees," she said.

In many cases, the orchid provides only a good time with no food reward, but by the time the bee figures this out, the orchid already received what it wants and needs: pollination.

"The male bees only need to be tricked twice: once for removing pollen from one orchid flower, and then once more for depositing this pollen on the stigma of another plant, ensuring pollination and subsequent fertilization and reproduction of the orchid," Gravendeel explained.

She added, "Once the real female bees appear above ground, the male bees quickly learn the difference and do not mate with orchid flowers anymore. These orchids have been pollinated by then, though, so there is no need to fool any more bees."

A moth orchid such as this is colorful enough to human eyes, with its beautiful hints of purple and yellow, but when seen from a pollinator's perspective, the flower is even more attractive. Honeybees, for example, cannot see the color red, but they can see a color that we cannot. It's known as "bee's purple," which is a mixture of yellow and ultraviolet.

Orchids dazzled renowned British naturalist Charles Darwin too. He predicted that many orchids co-evolved with pollinators, such that their shapes should match the bodies of these other beneficial organisms. The new research provides evidence for Darwin's prediction, Yang said, with the competition between the two protein complexes being part of the co-evolution process.

Read more at Discovery News

What are Ceres' Mysterious White Spots? You Decide!

Ever since NASA’s Dawn spacecraft arrived in the vicinity of dwarf planet Ceres, the world has been abuzz with theories as to what those mysterious white spots may be. Now, in an effort to further engage Dawn mission fans and have some fun along the way, NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., has created a public poll asking what we think those enigmatic blobs are.

“Can you guess what’s creating those unusual bright spots on Ceres? On March 6, NASA’s Dawn spacecraft began orbiting Ceres, the largest body in the main asteroid belt between Mars and Jupiter. Even before the spacecraft arrived at the dwarf planet, images revealed mysterious bright spots that captivated scientists and observers alike. Until Dawn gets a closer look over the next few months, it’s anyone’s guess what those spots could be.” — Dawn mission site.

The mystery surrounding these spots is as interesting as it is confusing. Even NASA has admitted that, for now, they are far from understanding what their origins are.

When initially arriving at Ceres, two conspicuous spots could be seen by Dawn. Presumed to be some kind of cryovolcanic feature, planetary scientists studying Dawn’s observations realized that there was no positive relief feature associated with the spots, hinting of the presence of a vent or crack. Cryovolcanism is still a possibility, but there are other ideas, including features such as reflective minerals or salt deposits.

As Dawn has entered its science orbit around the small world, no doubt the multiple white spots that are now known to dot the surface will become the prime focus of Dawn’s instrumentation.

But for now, JPL wants to know what you think these mystery bright spots are. (Sadly, “Alien Solar Array” isn’t one of the options.)

From Discovery News

Apr 26, 2015

To flare or not to flare: The riddle of galactic thin to thick disk solved

A long-standing puzzle regarding the nature of disk galaxies has finally been solved by a team of astronomers led by Ivan Minchev from the Leibniz Institute for Astrophysics Potsdam (AIP), using state-of-the-art theoretical models. The new study shows that groups of stars with the same age always flare as the result of massive galactic collisions. When taken all together, these flares, nested like the petals of a blooming rose, puff up the disk and constitute what astronomers call the "thick" disk.

"We were able to show for the first time that galactic thick disks are not composed only of old stars but must also contain young stars at larger distances from the galactic center," explains Minchev. "The flaring seen in groups of stars with the same age is caused mostly by the bombardment of small satellite galaxies. These cosmological car crashes pummel the young disk and cause it to swell and flare. "

To arrive at this new result, the team ran numerical simulations on massive super computers and examined the structure of their simulated galaxies. The scientists grouped stars by common age and looked at where they were located. What they found was that stars of a given age group constituted a disk with flared edges, much like the mouth of a trumpet. This flaring is unavoidable, being caused when the main galaxy collides with smaller galaxies - a generic feature of how scientists believe galaxies form. Since the oldest stars formed in the inner region of the galaxy, for them this flaring occurs closer to the center, while for the younger stars it occurs at the periphery of the galaxy. When put together, the combination of flaring from all the stars produces the elusive thick disk, as observed.

One of the most fascinating aspects of galaxies is that their stars can be separated into two components: a fluffy thick disk that enshrouds a thin disk. Until now the understanding has been that stars in the thick disk were the oldest. In observations of the Milky Way the oldest stars are found to be closer to the center, while younger stars are more extended. Scientists agree that this separation is likely due to an "inside-out" formation scenario, wherein the Milky Way forms stars first in its center and later in its outer region, much like how cities grow radially from a medieval center to modern suburbs.

Observing the structure of the Milky Way is tricky, since we are located within its disk, roughly half way from the center. Instead, astronomers have to rely on the stars that surround us and build a model from this limited perspective. Nevertheless, if the Milky Way were similar to other galaxies and its thick disk were composed only of old, centrally concentrated stars, then one would naively expect its thick disk to be short. But in other galaxies the thick disks are observed to be as extended as the galaxies themselves. Minchev's results resolve this contradiction by requiring that thick disk stars become younger in the disk outskirts.

Read more at Science Daily

Scientists develop first liquid nanolaser

Northwestern University scientists have developed the first liquid nanoscale laser. And it's tunable in real time, meaning you can quickly and simply produce different colors, a unique and useful feature. The laser technology could lead to practical applications, such as a new form of a "lab on a chip" for medical diagnostics.

To understand the concept, imagine a laser pointer whose color can be changed simply by changing the liquid inside it, instead of needing a different laser pointer for every desired color.

In addition to changing color in real time, the liquid nanolaser has additional advantages over other nanolasers: it is simple to make, inexpensive to produce and operates at room temperature.

Nanoscopic lasers -- first demonstrated in 2009 -- are only found in research labs today. They are, however, of great interest for advances in technology and for military applications.

"Our study allows us to think about new laser designs and what could be possible if they could actually be made," said Teri W. Odom, who led the research. "My lab likes to go after new materials, new structures and new ways of putting them together to achieve things not yet imagined. We believe this work represents a conceptual and practical engineering advance for on-demand, reversible control of light from nanoscopic sources."

Odom is Board of Lady Managers of the Columbian Exposition Professor of Chemistry in the Weinberg College of Arts and Sciences.

The findings were published this week by the journal Nature Communications.

The liquid nanolaser in this study is not a laser pointer but a laser device on a chip, Odom explained. The laser's color can be changed in real time when the liquid dye in the microfluidic channel above the laser's cavity is changed.

The laser's cavity is made up of an array of reflective gold nanoparticles, where the light is concentrated around each nanoparticle and then amplified. (In contrast to conventional laser cavities, no mirrors are required for the light to bounce back and forth.) Notably, as the laser color is tuned, the nanoparticle cavity stays fixed and does not change; only the liquid gain around the nanoparticles changes.

The main advantages of very small lasers are:

  • They can be used as on-chip light sources for optoelectronic integrated circuits;
  • They can be used in optical data storage and lithography;
  • They can operate reliably at one wavelength; and
  • They should be able to operate much faster than conventional lasers because they are made from metals.

Some technical background

Plasmon lasers are promising nanoscale coherent sources of optical fields because they support ultra-small sizes and show ultra-fast dynamics. Although plasmon lasers have been demonstrated at different spectral ranges, from the ultraviolet to near-infrared, a systematic approach to manipulate the lasing emission wavelength in real time has not been possible.

The main limitation is that only solid gain materials have been used in previous work on plasmon nanolasers; hence, fixed wavelengths were shown because solid materials cannot easily be modified. Odom's research team has found a way to integrate liquid gain materials with gold nanoparticle arrays to achieve nanoscale plasmon lasing that can be tuned dynamical, reversibly and in real time.

The use of liquid gain materials has two significant benefits:

  • The organic dye molecules can be readily dissolved in solvents with different refractive indices. Thus, the dielectric environment around the nanoparticle arrays can be tuned, which also tunes the lasing wavelength.
  • The liquid form of gain materials enables the fluid to be manipulated within a microfluidic channel. Thus, dynamic tuning of the lasing emission is possible simply by flowing liquid with different refractive indices. Moreover, as an added benefit of the liquid environment, the lasing-on-chip devices can show long-term stability because the gain molecules can be constantly refreshed.
Read more at Science Daily