Dec 14, 2013

Scientists Improve Human Self-Control Through Electrical Brain Stimulation

If you have ever said or done the wrong thing at the wrong time, you should read this. Neuroscientists at The University of Texas Health Science Center at Houston (UTHealth) and the University of California, San Diego, have successfully demonstrated a technique to enhance a form of self-control through a novel form of brain stimulation.

Study participants were asked to perform a simple behavioral task that required the braking/slowing of action -- inhibition -- in the brain. In each participant, the researchers first identified the specific location for this brake in the prefrontal region of the brain. Next, they increased activity in this brain region using stimulation with brief and imperceptible electrical charges. This led to increased braking -- a form of enhanced self-control.

This proof-of-principle study appears in the Dec. 11 issue of The Journal of Neuroscience and its methods may one day be useful for treating attention deficit hyperactivity disorder (ADHD), Tourette's syndrome and other severe disorders of self-control.

"There is a circuit in the brain for inhibiting or braking responses," said Nitin Tandon, M.D., the study's senior author and associate professor in The Vivian L. Smith Department of Neurosurgery at the UTHealth Medical School. "We believe we are the first to show that we can enhance this braking system with brain stimulation."

A computer stimulated the prefrontal cortex exactly when braking was needed. This was done using electrodes implanted directly on the brain surface.

When the test was repeated with stimulation of a brain region outside the prefrontal cortex, there was no effect on behavior, showing the effect to be specific to the prefrontal braking system.

This was a double-blind study, meaning that participants and scientists did not know when or where the charges were being administered.

The method of electrical stimulation was novel in that it apparently enhanced prefrontal function, whereas other human brain stimulation studies mostly disrupt normal brain activity. This is the first published human study to enhance prefrontal lobe function using direct electrical stimulation, the researchers report.

The study involved four volunteers with epilepsy who agreed to participate while being monitored for seizures at the Mischer Neuroscience Institute at Memorial Hermann-Texas Medical Center (TMC). Stimulation enhanced braking in all four participants.

Tandon has been working on self-control research with researchers at the University of California, San Diego, for five years. "Our daily life is full of occasions when one must inhibit responses. For example, one must stop speaking when it's inappropriate to the social context and stop oneself from reaching for extra candy," said Tandon, who is a neurosurgeon with the Mischer Neuroscience Institute at Memorial Hermann-TMC.

Read more at Discovery News

China Lands Rover on The Moon

China has landed its first robotic lander on the moon, a historic lunar arrival that makes the country only the third nation to make a soft-landing on Earth's celestial neighbor.

China's Chang'e 3 moon lander and its Yutu rover touched down on the moon Saturday (Dec. 14) at about 8:11 a.m. EST (1311 GMT), though it was late Saturday night local time at the mission's control center in Beijing during the landing. It is the first soft-landing on the moon by any spacecraft in 37 years.

Chang'e 3 launched toward the moon on Dec. 2 Beijing time to begin its two-week trek to the lunar surface. The spacecraft arrived in lunar orbit about five days after launch, and then began preparing for landing. A camera on the spacecraft snapped 59 photos of the moon during the descent, including a view straight from the lunar surface just after touchdown.

China on the moon

Following a lengthy engine burn Saturday, the mooncraft lowered itself to the lunar surface on autopilot, making what appeared to be a smooth touchdown on the Bay of Rainbows in the moon's northern hemisphere. The descent from lunar orbit to the moon's surface took about 12 minutes.

Chang'e 3's soft-landing was billed as the "black 12 minutes," deemed as the most difficult task during the mission, said Wu Weiren, the lunar program's chief designer.

Shortly after landing, Chang'e 3 deployed its vital solar arrays, which were folded for the landing, to begin generating power for its lunar surface mission. The lander is now expected to unleash the instrument-laden Yutu rover, built to trundle across the dusty, time-weathered terrain for months.

China Chang'e 3 lunar arrival is the first soft-landing on the moon since 1976. Not since the former Soviet Union's Luna 24 sample-return mission has a spacecraft made a controlled, soft touchdown on the lunar surface. The last soft-landing on the moon by NASA was in 1972 during the Apollo 17 manned lunar landing mission.

The Yutu rover (its name means "Jade Rabbit") is named after the pet rabbit that travels with the goddess Chang’e to the moon in Chinese legends. Chang'e 3 is China's third lunar mission to carry the name, but the first to land on the moon. The first two Chinese lunar missions only orbited the moon.

The six-wheeled Yutu rover is a solar-powered vehicle equipped with cameras, a robotic arm tipped with science gear and a radar system attached to its underbelly.

The stationary lander itself also is geared to observe Earth, astronomically eye other celestial objects from the moon, as well as watch the Yutu rover wheel across the lunar terrain.

Live from the moon: Chang'e 3's lunar views

Chang'e 3 transmitted live images as it neared the surface of the moon.

"It seems that Chang'e has decided on its landing site," one Chinese TV commentator said on state-run CNTV news during the spacecraft's descent.

Applause broke out in the Chang'e 3 mission control center when the lander plopped down on the moon.

"China succeeds in first attempt at soft-landing on the moon," a running banner noted on China’s CCTV.

Very little dust appeared to be kicked up during the landing as the vehicle's motor cut off as planned just above the moon's landscape. The Chang'e 3 lander then drifted down onto the barren terrain.

And there was another touch of space history marked during China's moon landing.

"Here is a very interesting angle," said James Rice, a science team member of the Mars Exploration Rover Project, Mars Space Flight Facility at Arizona State University. "On this date in 1972, Apollo 17's Gene Cernan took the last steps from the moon’s surface as he climbed aboard the Challenger lunar module."

Cernan served as mission commander for Apollo 17, which was NASA's final Apollo moon landing flight by astronauts.

Renewed moon exploration

"This is a great day for lunar science and exploration, with the first successful soft landing on the surface of the Moon since the Soviet Union did it in 1976," said Clive Neal, a leading lunar scientist at the University of Notre Dame's Department of Civil and Environmental Engineering and Earth Sciences.

"Congratulations to the Chang'e 3 team and China," Neal told

Neal said that Chang'e 3's touchdown "demonstrates the potential for renewed robotic exploration on the lunar surface that will inevitably lead to new scientific discoveries. I am very excited!"

"From the widest lens, the resurgence of multi-national interest in the moon is an important signal that the moon is not an artifact of history … but a new world that's important to our future," said Bob Richards, co-founder of Moon Express, the private U.S. entrepreneurial group working on its own lunar lander system.

"With a narrow lens, I hope the U.S. will be inspired to support a return to the moon through the power of commercial space entrepreneurship coupled with smart government partnerships and incentives," Richards told

Long-term lunar commitment

Richards said that China landing on the moon signals a new era of human expansion into space.

"I hope the U.S. and others return to the moon as a frontier of peaceful international exploration and economic development," he said.

"The first two nations to reach the surface of the moon were in a race to do so," Richards said. "China becomes the third nation to land on the moon in the context of a long-term national commitment to lunar exploration and settlement. I am hopeful that humanity’s future exploration and development of the Moon will unfold with peace and prosperity for everyone on Earth."

"Back on the surface of the moon … congratulations to the Chang'e 3 team," said Mark Robinson of Arizona State University's School of Earth and Space Exploration. Robinson is the Lunar Reconnaissance Orbiter Camera (LROC) Principal Investigator on NASA's Lunar Reconnaissance Orbiter currently orbiting the moon.

"Many around the world have been waiting decades for this moment," Robinson said. "I can't wait to see images of the rover, lander, and landscape! Exciting!"

NASA view on China moon landing

Late Friday (Dec. 13), NASA released an official statement on China's Chang'e 3 mission, one geared specifically toward the science benefits of the endeavor.

"China's lunar lander may provide additional science for NASA spacecraft," NASA officials said in the statement. "Scientists using four NASA spacecraft currently studying our lunar neighbor may get an opportunity to gather new data from the expected December 14 landing of the Chang'e 3 lunar rover. U.S. and international researchers view the pending arrival as a new scientific opportunity that could potentially enhance studies and observations of the lunar atmosphere."

Read more at Discovery News

Dec 13, 2013

The Frog Whose Young Erupt From Under Its Skin

We need to talk, Mom. You’re smothering us. We need space.
Amphibians have it made. Frogs sometimes just up and turn into princes, salamanders can emerge from fire unscathed, and a certain newt almost got to the White House in 2012. And add to these triumphs the fact that egg-laying amphibians don’t have to mess with live birth, an excruciating event that your mother tearfully reminds you of whenever you forget her birthday, which I may or may not have done once in high school.

There is an amphibian, though, that deviates wildly from the reproductive norm. This is the Surinam toad, Pipa pipa, whose females absorb their eggs into their own backs. Here the embedded young develop safely before erupting through their mom’s skin into a world where they’ll need to make damn sure they never forget her birthday, even if it was way back in high school and they had a lot on their plate at the time.

The Surinam toad’s existence begins with some good old sexual somersaults. It’s a highly aquatic frog, and is thus afforded the opportunity of having what herpetologist David Cannatella of the University of Texas calls “acrobatic” mating interactions.

When two Surinam toads love each other very much, the male grasps the female in what’s known as amplexus. “He’s holding on while she is swimming around and often she’s doing somersaults, not just sitting there on the bottom,” said Cannatella. “And that’s really unusual in frogs, because most frogs aren’t that aquatic.” (Toads are a kind of frog, and actually the Surinam toad more resembles a regular frog than a toad — the distinctions are a bit informal and a bit silly.)

A female Surinam toad with her recently hatched young in a nice autumn scene.
“Prior to this the skin on the back of the female, the dorsum, has begun to thicken because of hormonal influence,” he added. As they somersault, the female extrudes eggs one at a time, which the male fertilizes. These land on the female’s back, where the skin “continues to get thicker and grows up around the egg, so essentially the egg is now embedded in this skin.”

Such acrobatics continue for more than 24 hours, and the female can end up with over 100 eggs in her back. Her young will develop in her skin for several months, skipping the tadpole stage entirely.

When they’re ready to leave, one by one they squeeze out of their mother’s back like escape pods jettisoning from a spaceship … that flies underwater. OK fine that’s not a great simile. It’s one of the more unsettling scenes in nature (see National Geographic’s footage below), but this is also an incredible evolutionary adaptation. Instead of laying her eggs elsewhere and exposing them to predation, the Surinam toad mother carries her young in the safety of her body, much like mammals evolved to do with their wombs. And when she’s done, she simply sheds the extra skin and goes about her business.

Yet this is far from the Surinam toad’s only peculiarity.

Yes, that’s how it’s supposed to look.
Its body is so astoundingly flat that Cannatella, a man who has dedicated his life to studying amphibians, has a hard time describing it beyond saying the thing looks like roadkill, which I can confirm as accurate, having once seen a roadkilled frog. The head in particular looks to taper down to an almost razor’s edge.

But this shape is — like every characteristic on the body of any living thing — an adaptation to its environment. The toad spends its days hidden among leaves at the bottom of South American ponds, habitat for which its flat, angular body and brown coloration are perfectly suited. And here it lies in wait for prey before launching a peculiar attack — at least for a frog.

Strangely, the Surinam toad is missing a tongue. “So what’s that related to?” asked Cannatella. “Well, they use suction feeding. When a fish or something swims in front of the frogs they open their mouths really quickly, and they generate suction that pulls the fish in.” No tongue required.

We see this strategy mirrored in a pair of other remarkable amphibians across the Pacific Ocean: two species of giant salamanders in Japan and China. These monsters can grow to 6 feet long, and like the Surinam toad they sport enlarged heads that help boost the vacuum power. They’re nature’s own Dysons.

A close-up of the Surinam toad’s strange fingers, which look suspiciously like those of the Martians in The War of the Worlds.
And also like these giant salamanders, the Surinam toad has puzzlingly tiny eyes. So how exactly does is it detect prey? It actually has the same kind of lateral line as sharks — a system of special sensory structures that detect changes in water pressure — and Cannatella suspects it’s using this to hunt for fish.

Interestingly, tadpoles of other frog species have this as well, but lose it as they mature into adults. The Surinam toad, being highly aquatic, has good reason to retain it. In the murky pond-bottoms that it inhabits, the lateral line would prove far more advantageous over eyesight when detecting prey (and it’s a great conversation-starter at shark parties).

In addition, the Surinam toad feels its way toward prey with its bizarre unwebbed fingers, each of which has four lobes at its tip that each further split into their own lobes, a bit like fractals.

Read more at Wired Science

Alligators and Crocodiles Use Tools to Hunt

It's official: Reptiles can use tools to help them hunt.

New research shows that alligators and crocodiles can use small sticks to attract birds looking for nesting materials. If the birds get too close, they become a meal. The behavior has so far been observed among American alligators in Louisiana, as well as mugger crocodiles (also known as marsh crocodiles) in India.

Alligators only engaged in this trickery during the nesting season and in areas where birds nested, said Vladimir Dinets, a behavioral ecologist at the University of Tennessee Knoxville. During nesting season, there's often a shortage of sticks in marshy areas where these reptiles and birds overlap, and birds sometimes even fight amongst themselves to procure sticks to build nests. The study, which Dinets co-authored and which was published in late November in the journal Ethology Ecology & Evolution, suggests that there is no other explanation for this behavior than as one of tool use.

"What's really remarkable — they are not only using lures, but they are timing it to just when the birds they want to capture are nesting and looking for sticks to use," said Gordon Burghardt, an ethologist (animal behaviorist) and comparative psychologist specializing in reptiles at UT-Knoxville. "They are making some assessment of the birds themselves."

"This is indeed the first convincing evidence of tool use in any reptile," said Burghardt, who wasn't involved in the study.

The finding, along with other recent work, suggests reptiles are much more intelligent than generally acknowledged, Dinets said. As anybody who studies the beasts can attest, they are quite smart, he added. Crocodiles, for example, have complex communication systems, can hunt in coordination and ambush prey, and both parents may help raise young, he said.

Relatively less is known about crocodiles and alligators than many animals, because, as large predators, they are difficult to raise in the lab and study up close in the wild. Their cold-bloodedness also makes them slow.

"They operate on a different time scale; they do things more slowly," Burghardt said. "Sometimes we don't have the patience to let them strut their stuff, as it were … so this kind of study is important."

Read more at Discovery News

Ancient Pig-Shaped Baby Bottle Found

Italian archaeologists have discovered an ancient terracotta pig which worked as a toy as well as a modern-day baby bottle.

Known as guttus, the unique vessel dates back about 2,400 years, when the “heel” of Italy was inhabited by the Messapian people, a tribal group who migrated from Illyria (a region in the western part of the Balkan peninsula) around 1000 B.C.

Featuring pointy ears and human-like eyes, the pig-shaped guttus featured terracotta rattles in its tummy to apparently encourage the baby to sleep after the meal.

The small terracotta pig is one of several rare objects found last May in Manduria, near Taranto in Puglia, when construction work exposed a Messapian tomb.

Cut into rock, the 8- by 4-foot tomb was decorated with ocher, red and blue bands. It contained the remains of two individuals — in line with the Messapian custom of burying family members together in the same grave.

“We found some skeletal remains piled in an angle. Other remains, related to a later burial, occupied the entire tomb,” archaeologist Arcangelo Alessio of the Archaeological Superintendency of Puglia, told Discovery News

Alessio and his team recovered about 30 funerary objects, which have now been cleaned and restored. They included jars, plates, lamps, ointment vases, three baby feeding vessels and two terracotta statuettes depicting female subjects.

Objects such as a black painted basin and an iron blade of a knife suggest a male burial, while a strong clue for a female burial came from a special Messapian pottery vase called trozzella. Featuring four little wheels at the tops of its handle, versions of the vase are often found in the graves of Messapian women.

“Analysis of the funerary objects and their context suggest that the two burials followed one another in the Hellenistic period, between the end of the fourth and the third-second centuries B.C.,” Alessio said.

The presence of three feeding vessels would point to a third burial, possibly belonging to a newborn girl, as suggested by the two terracotta statuettes found in the tomb. Indeed, these sculptures were often placed in burials of young girls.

Read more at Discovery News

1,900 Cyclones Whip the Arctic Every Year

Santa’s reindeer must be trained to fly through severe weather around the North Pole.

Approximately 1,900 cyclones per year whirl across the Arctic, churning the ocean and potentially contributing to the loss of sea ice. The Arctic System Reanalysis (ASR) research group recently counted the Arctic twisters and found approximately 40 percent more than expected.

“We now know there were more cyclones than previously thought, simply because we’ve gotten better at detecting them,” said ASR study leader David Bromwich, professor of geography at Ohio State University, in a press release.

“We can’t yet tell if the number of cyclones is increasing or decreasing, because that would take a multidecade view. We do know that, since 2000, there have been a lot of rapid changes in the Arctic — Greenland ice melting, tundra thawing — so we can say that we’re capturing a good view of what’s happening in the Arctic during the current time of rapid changes.”

Many of the cyclones were small and lasted only a short time. The storms often raged over unpopulated areas so the only way to observe them was with satellite imagery, weather balloons, buoys and weather stations on the ground. A supercomputer at Ohio State crunched that weather data to detect previously unseen cyclones. The data ranged from 2000-2010.

Although unseen, the storms may play apart in the record reductions in sea ice in the Arctic. As the storms trouble the waters of the Arctic Ocean, they pull up warmer, deeper water. When the warmer water mixes with the surface water, it may speed the disappearance of the ice.

The ASR team presented their research at the  American Geophysical Union meeting on December 12.

From Discovery News

Tsunami Record Discovered in Indonesia Cave

A cave on the Indonesian island of Sumatra is providing a "stunning" record of Indian Ocean tsunamis over thousands of years.

Paleo-oceanographers say layers of tsunami-borne sediments found in the cave in northwest Sumatra suggest the biggest destructive waves do not occur at set intervals -- meaning communities in the area should be prepared at all times for a tsunami.

"It's something that communities need to know," research team leader Charles Rubin told AFP, adding that the team wanted to "promote safety of coastal communities".

Professor Rubin and other researchers from a Singapore institute were working with scientists from an Indonesian university when they discovered the cave, south of Banda Aceh, the capital of Aceh province.

A quake-triggered tsunami devastated Aceh and areas across the Indian Ocean in 2004, leaving some 170,000 people dead in the province alone.

Inside the cave the researchers found layers of sandy sediment, which had been washed in by tsunamis thousands of years previously, Rubin said.

The layers, which contained small fossils from the seabed, were well-preserved and separated by droppings deposited by bats in the cave, he added.

"This is a beautiful, stunning record of tsunamis that you just don't have very often," Rubin said.

Only huge tsunamis and storm surges can get into the cave, which has a raised entrance -- and afterwards the sediment is protected inside from erosion by wind or water.

Rubin said the scientists dated the layers and believe they show that between 2,800 and 3,300 years ago, some four to five tsunamis battered the area.

Before the 2004 tsunami, it had been hundreds of years since such a huge destructive wave had hit Aceh, the scientist said.

But he said the new discovery suggests that tsunamis are not evenly spaced through time, which should provide food for thought for those involved in policy and planning in the region.

Read more at Discovery News

Dec 12, 2013

It's a Duck, It's a Rooster, It's a … Dinosaur?

What has a mouth like a duck's and a comb like a rooster's? A dinosaur that roamed North America 75 million years ago.

A new fossil discovery reveals the duck-billed dinosaur Edmontosaurus regalis sported a fleshy comb on its head, similar to the ones on modern-day roosters. No such comb has ever been discovered before on a dinosaur.

"We're never short of being surprised by what these animals looked like," said study researcher Phil Bell, a paleontologist at the University of New England in Australia.

Finding the fossil

Duck-billed dinosaurs, or hadrosaurs, were large herbivores that filled the same ecological niche as deer or kangaroo today. In the past century, paleontologists have discovered several hadrosaur fossils with skin impressions pressed into the rock around the bones. These "mummy" specimens, so dubbed because they reveal more than just bone, show that hadrosaurs had pebbly skin not unlike that of today's crocodiles and birds.

But skin impressions rarely preserve well around the skull, Bell said.

Bell's colleague, Federico Fanti, discovered the new E. regalis fossil in west central Alberta, about 45 miles (75 kilometers) from the town of Grande Prairie. They were surveying a well-known fossil site when Fanti noticed a string of vertebrae peeking out of a coffin-size boulder, Bell told LiveScience. The researchers had not found many bones still articulated in their original configurations, so they decided to collect the specimen.

"Because the block was too big to move on its own, we used a rock saw in an attempt to trim it down," Bell said. "But no sooner did we start cutting into it than we found the first skin impression. We kind of had to bite the bullet and collect the whole block."

It was seven months before the team could get to the site with a truck and trailer, because the nearby Redwillow River was so high. But in 2011, the researchers drove a truck across the river, winched the boulder onto a trailer and brought it out of the field.

While Bell was preparing the fossil, he discovered something even more amazing than skin impressions.

"Having a good idea of the outline of the animal, I put my chisel into the rock, not expecting to hit anything, and lo and behold, I realized I'd put my chisel straight through the middle of some skin impressions that shouldn't have been there," he said.

Surprising skin

Bell had found a fleshy dome extending off of the duckbill's skull -- something that had never been seen before. The dome included no bones and extended from the front of the eye sockets to the back of the head. It was almost 8 inches (20 centimeters) tall at its highest point and about 13 inches (33 cm) long.

"You can actually see the wrinkles in the skin that indicate that it had some flexibility to it," Bell said.

In modern birds, such combs are typically used for sexual display. They're found in both sexes in birds, so the presence of the comb tells researchers nothing about their dinosaur specimen's sex. The bones they do have belong to the neck and head, and don't reveal sex either.

"What we need to find now are additional specimens that show this structure, and perhaps by comparing their sizes or relative development, we might get an idea of their sex," Bell said.

It's not clear whether the comb is a feature only of E. regalis or if other duckbills might have had similar fleshy accessories. Skin associated with the head may not preserve well, meaning that other combs have vanished without a trace, Bell said. Or, they may have been overlooked. In the past, paleontologists considered skin impressions less interesting than bones, so they ignored them.

Read more at Discovery News

Music Actually Doesn't Produce Baby Einsteins

For all the parents hoping that classical music CDs and music classes will give their kids an intellectual leg up, Harvard researchers have some bad news: Mozart won’t boost your IQ.

Two studies published today in the journal PLOS ONE bust the myth. In the first, researchers reviewed dozens of studies, and found just one that used randomized trials and showed a positive link between music and IQ. Even then, the effect was so tiny — 2.7 points on an IQ test after one year of music lessons — that it barely registered as statistically significant.

“More than 80 percent of American adults think that music improves children’s grades or intelligence,” said researcher Samuel Mehr, a Harvard Graduate School of Education doctoral student. “Even in the scientific community, there’s a general belief that music is important for these extrinsic reasons — but there is very little evidence supporting the idea that music classes enhance children’s cognitive development.”

Next, Mehr conducted his own research, teaching music and visual art classes to 4-year-olds.

“We wanted to test the effects of the type of music education that actually happens in the real world, and we wanted to study the effect in young children, so we implemented a parent-child music enrichment program with preschoolers,” Mehr said. “The goal is to encourage musical play between parents and children in a classroom environment, which gives parents a strong repertoire of musical activities they can continue to use at home with their kids.”

Mehr then tested the kids in four specific areas of cognition, which is designed to pick up subtle cognitive benefits better than a general IQ test. The tests showed no evidence that the musical training had affected intelligence.

Read more at Discovery News

Hubble Discovers Water Plumes Over Europa

Scientists using the Hubble Space Telescope have found plumes of water vapor shooting off the southern pole of Europa, an ice-covered moon of Jupiter that is believed to have an underground ocean.

If confirmed -- so far the plumes have only been spotted once -- the finding could have implications for the moon’s suitability for life and help explain why its surface appears relatively young and crater-free.

“The plumes are incredibly exciting, if they are there. They’re bringing up material from in the ocean, perhaps there’s organic material that will be laying on the surface of the south pole. Those are the things that we want to know about,” James Green, head of NASA’s planetary science programs, told reporters at the American Geophysical Union conference in San Francisco on Thursday.

Scientists do not yet have enough information to know if the plumes are indeed stemming from Europa’s underground ocean, or if they are the result of plates of ice rubbing together and generating heat from friction, which allows some ice to vaporize.

The plumes were found when Europa was farthest away from Jupiter, a time when gravitational stresses are strongest, added Lorenz Roth, with the Southwest Research Institute in San Antonio, Texas.

“When Europa is close to Jupiter, it gets stressed and the poles get squished and the cracks close up. Then, as it moves further away from Jupiter, it becomes un-squished, the pole moves outward and that’s when the cracks open,” planetary scientist Francis Nimmo, with the University of California in Santa Cruz told Discovery News.

Using data from Hubble, scientists were able to correlate the plumes with the appearance of cracks in moon’s surface ice.

Additional observations with Hubble are planned to attempt to verify the findings. Scientists also will be re-examining archived data collected by NASA’s Galileo spacecraft, which made nine passes by Europa in the late 1990s.

“We’ll have some other great results, or another controversy,” Green said.

The Saturn-orbiting Cassini spacecraft has found similar plumes blasting off the icy moon Enceladus. The Saturn moon is much smaller and has less gravity, so its plumes shoot far higher into space. However, the density of water vapor in the moons’ plumes is remarkably similar, scientists said.

On Europa, the plumes reach an altitude of about 125 miles, fall back to the surface and freeze within about 20 minutes, Roth said.

Read more at Discovery News

Exoplanets' Life-Giving Potential Just Got Bigger

Earth's place in the solar system is just right. It's not too hot, like Venus, and it's not too cold, like Mars, and this "Goldilocks zone" of habitability around other stars like the sun just might be bigger than thought, scientists say.

A new study, unveiled today (Dec. 11), expands the habitable zone — the sweet spot in a solar system where liquid water and therefore life could potentially exist — surrounding stars like the sun.

Previous studies on the habitability zone around sunlike stars have placed the innermost edge of so-called Goldilocks zone at about 0.99 AU (1 AU, or astronomical unit, is the average distance from Earth to the sun, about 93 million miles, or 150 million kilometers). But a new computer model study pushes that border closer to its parent star, to a distance of about 0.95 AU (about 88 million miles, or 142 million kilometers).

The study in the journal Nature, led by Jeremy Leconte, now a postdoc at the Canadian Institute for Theoretical Astrophysics of the University of Toronto, used 3D computer modeling to find that the runaway greenhouse effect isn't an issue unless the planet is less than 0.95 AU from its star.

The new inner boundary for habitable zones might not make a big difference for scientists trying to determine if an alien planet is habitable, but it does make a big difference for future life on Earth, Leconte said.

Eventually, the sun will become brighter, heating the Earth and potentially creating a runaway greenhouse effect — a feedback loop that eventually causes a planet's oceans to boil away. But that eventuality is long way off, and it may now actually be farther off than previously expected, Leconte suggests.

"For example, if we believe that the limit is at 0.99, it means that Earth would start losing oceans around 150 million years from now," Leconte told "Now, with our new estimate, it's not 150 million years, but it's actually 1 billion years, so almost an order of magnitude bigger."

Unlike previous one-dimensional studies, the new modeling takes clouds and circulation into account, putting the inner edge of the habitable zone closer to a star. This buys Earth a little more time, although the planet is still quite close to the near end of the habitable zone.

"From the perspective of the Earth, this is a big change, and it's because the Earth is thought to be quite close to the inner edge," Leconte, who conducted this research while at the Intitut Pierre- Simon Laplace in Paris, said. "We now find that it's not that close. It's still very close into the habitable zone compared to what could be other planets we see out there."

Leconte did use climate data collected for Earth science in the model, but he took out some of the more specific information to create a general model for rocky planets circling sunlike stars.

Alien Planets

The new model could help scientists more fully understand what constitutes a habitable alien planet as well.

"We now have the real framework for understanding these objects not as just dots but as real planets that have a surface, an atmosphere where complex processes like cloud formation can happen like on the Earth," Leconte said. "In a way we see them more as worlds than just as planets."

Although the size of the habitable zone calculated by Leconte is larger than other estimates in the past, it is also much smaller than more recent estimates used to analyze data from the alien- planet-hunting Kepler space telescope.

Earlier this year, scientists using the Kepler data estimated that 22 percent of sunlike stars may harbor a rocky planet in their habitable zones, however, the research team used a broad definition for the habitable zone, marking the inner edge at 0.5 AU, James Kasting, a professor of geosciences at the University of Pennsylvania, said.

"If you take the Petigura analysis [Kepler-based study] at face value, their number might be too high by a factor of two," Kasting, who wrote a News & Views piece about Leconte's study in this week's Nature, told

Oceans on Venus?

Leconte's new work does help constrain the habitable zone around sunlike stars, but it could also have a bearing on the Goldilocks zones around other, dimmer stars. Scientists hope to use 3D modeling in the future to understand how a rocky planet around a dim star could fare as well.

Read more at Discovery News

Dec 11, 2013

Lizard Breath May Have Evolved Before Dinosaurs

Monitor lizards breathe by taking in air that flows through their lungs in a one-way loop -- a pattern of breathing that may have originated 270 million years ago in the ancestral group that gave rise to dinosaurs, and eventually alligators and birds, a new study finds.

Researchers at the University of Utah, in Salt Lake City, and Harvard University, in Cambridge, Mass., studied unidirectional breathing in monitor lizards, which can be found throughout Africa, China, India and other parts of Southeast Asia. Their findings suggest one-way airflow breathing may have evolved earlier than scientists had thought.

The researchers examined lungs from living and deceased monitor lizards, and found that when these large, often-colorful, carnivorous reptiles breathe, the airflow through their lungs is mostly one-way, unlike in humans and other mammals, which have a "tidal," or two-way, breathing pattern. Human lungs consist of a network of tubes that branch out into progressively smaller airways. Tidal breathing means air enters the lungs through these airways and then flows back out again the same way.

One-way airflow in birds was first suggested in the 1930s, said Colleen Farmer, an associate professor of biology at the University of Utah and senior author of the new study.

"It was first noted in birds that were living in train stations in Europe," Farmer told LiveScience. "They were burning coal to power trains and noticed that only one part of the bird's lung was getting black with soot."

This method of breathing was thought to have evolved in birds to help them extract higher amounts of oxygen from their environment. Since air travels in only one direction through birds' lungs, more oxygen is transferred through their respiratory systems with each breath, which enables them to fly at high altitudes, where oxygen levels are low, without getting winded or passing out.

Similarly, it was speculated that one-way airflow may have helped the ancestors of dinosaurs roam the Earth beginning roughly 251 million years ago, after the Permian-Triassic mass extinction that wiped out up to 70 percent of terrestrial vertebrate species. Following the devastating extinction event, which formed the boundary between the Permian and Triassic periods, the level of atmospheric oxygen was thought to be significantly lower than today's levels.

In 2010, Farmer published a study detailing similar unidirectional airflow in alligators, which suggests the breathing pattern likely evolved about 250 million years ago, when the ancestors of alligators and crocodiles split from the ancient archosaurs, the group that led to the evolution of dinosaurs, flying pterosaurs and eventually birds.

Read more at Discovery News

New Clues May Reveal Fate of Roanoke Settlers

It's the coldest case in American history.

The settlers who inhabited the 16th century North Carolina colony of Roanoke mysteriously disappeared centuries ago, leaving behind only two clues: the words "Croatoan" and "Cro" carved into a fort's gatepost and a nearby tree.

Many conspiracy theories have been concocted as to what happened in 1590, a mere three years after the colonists arrived in North America, but none have proven fruitful. Until now. Technological advances and the discovery of a cover-up on an ancient map have let researchers unearth new clues that may help bring an end to the mystery of America's lost colony.

Researchers began reinvestigating the mysterious disappearance after they noticed two strange patches on a long-forgotten map of the area called "La Virginea Pars" drawn by the colony's governor John White. Researchers at the First Colony Foundation in Durham, N.C., believed the two patches might be covering up something revealing.

The map was analyzed by scientists at the British Museum, who discovered a small red-and-blue symbol.

"Our best idea is that parts of [Sir Walter] Raleigh's exploration in North America were a state secret, and the map 'cover-up' was an effort to keep information from the public and from foreign agents," historian and principal investigator Eric Klingelhofer of Mercer University in Macon, Ga., told National Geographic, which partially funded the effort.

Historians believe that the symbol may have been the location of a fort the settlers fled to, running from violence or disease.

"It's obvious that that's the only way they could have survived. No single Indian tribe or village could have supported them ... They were over a hundred people," Klingelhofer said.

The current theory is that the colonists fled 50 miles south to Hatteras Island, then known as Croatoan Island. Klingelhofer suggests they may have gone in a different direction.

He believes the settlers traveled west via the Albermarle Sound to the Chowan River where there might have been a protected inlet occupied by a friendly tribe.

"It's a very strategic place, right at the end of Albemarle Sound," he said. "You can go north up the Chowan River to Virginia or west to the Blue Ridge Mountains. They were big trading partners with other Native American tribes."

Once the researchers uncovered the secrets of the "La Virginea Pars" map, they scheduled a trip to visit the area along with the help of magnetometers and ground-penetrating radar (GPR).

"What we do is we get the oldest maps we can find—so we can get a historic sense of what was there and what's there now—and orient them," said research associate Malcolm LeCompte at Elizabeth City State University in North Carolina, who was responsible for the GPR.

He looked for similarities between the old map and the current topography. The researchers than used GPR, which sends radio waves into the ground and measures the echo of the signals that bounce off of objects underground.

LeCompte and his team found a previously undiscovered pattern that indicated the possibility of multiple wooden structures approximately 3 feet underground.

"I don't know if it's one or a group [of structures]," he said, adding that they "could be joined or they could be close together."

Read more at Discovery News

Terracotta Warriors Inspired by Ancient Greek Art

The Terracotta Warriors, along with other life-size sculptures built for the First Emperor of China, were inspired by Greek art, new research indicates.

About 8,000 Terracotta Warriors, which are life-size statues of infantryman, cavalry, archers, charioteers and generals, were buried in three pits less than a mile to the northeast of the mausoleum of Qin Shi Huangdi, the first emperor. He unified the country through conquest more than 2,200 years ago. Pits containing sculptures of acrobats, strongmen, dancers and civil servants have also been found near the mausoleum.

Now, new research points to ancient Greek sculpture as the inspiration for the emperor's afterlife army.

"It is perfectly possible and actually likely that the sculptures of the First Emperor are the result of early contact between Greece and China," writes Lukas Nickel, a reader with the School of Oriental and African Studies at the University of London, in the most recent edition of the journal Bulletin of the School of Oriental and African Studies. (A reader is a position comparable to an associate or full professor in the American system.)

Nickel's evidence includes newly translated ancient records that tell a fantastic tale of giant statues that "appeared" in the far west, inspiring the first emperor of China to duplicate them in front of his palace. This story offers evidence of early contact between China and the West, contacts that Nickel says inspired the First Emperor (which is what Qin Shi Huangdi called himself) to not only duplicate the 12 giant statues but to build the massive Terracotta Army along with other life-size sculptures.

Before the First Emperor's time, life-size sculptures were not built in China, and Nickel argues the idea to build so many of them, so suddenly, came from kingdoms in Asia that had been created and influenced by Alexander the Great's campaigns.

'Giants' appearing in the west

Nickel translated ancient Chinese records that tell a tale of 12 giant statues, clad in "foreign robes" that "appeared" in Lintao in what was the westernmost part of China. (The word "Lintao" can also mean any place far to the west.)

The records do not say how this appearance happened, who brought them there, or who exactly the statues depicted; they do reveal the statues were larger than life, rising about 38 feet (11.55 meters) high, with feet that were 4.5 feet long (1.38 m). They so impressed the First Emperor that he decided to build 12 duplicates in front of his palace by melting down bronze weapons that had been used for war.

On each duplicate an inscription was created telling of the "giants" (the original statues) that appeared in Lintao. The inscriptions, recorded by Yan Shigu, who lived around 1,400 years ago and used an earlier written source, said that in the "26th Year of the Emperor, when he first brought together all-under-heaven, divided the principalities into provinces and districts, and unified the weights and measures, giants appeared in Lintao ..."

The First Emperor duplicated these statues despite a "heavenly taboo" that "he who recklessly follows foreign models will encounter disaster," wrote Ban Gu, a historian who lived almost 2,000 years ago. Ban worked for the dynasty that had overthrown the First Emperor's dynasty and, as such, tried to cast him in a negative light.

These giant duplicates no longer exist, having been destroyed in the centuries after the First Emperor's death. Because the duplicates were displayed publicly in front of the First Emperor's palace ancient writers left records of them behind, Nickel told LiveScience. Meanwhile, the Terracotta Warriors, though they survive to present day, were buried in pits out of sight and, as such, no record of them survives today.

Even so, the newly translated records suggest contact, of some form, occurred between ancient China and kingdoms in Central Asia that had been influenced by Greek culture and its sculpture-building tradition.

Acrobats and dancers

A few dozen statues of half-naked acrobats and dancers were also found in separate pits near the First Emperor's mausoleum.

"Here the sculptors attempted to render a bone structure, muscles and sinews to depict a person in movement," Nickel writes in his paper. "This comes close to an understanding of the human body that was employed at the time only in Hellenistic (Greek influenced) Europe and Asia."

He argues that creating this sort of realistic sculpture is not something that a sculptor could learn without some practice, taking the ancient Greeks centuries to master it.

"The creation of a believable human body preoccupied generations of Greek sculptors. It was a complex artistic and intellectual process that did not happen overnight," Nickel writes.

Why did they stop building the statues?

All this research leaves another mystery in its wake. After the First Emperor's death the rulers that came to power, the Han Dynasty, stopped building life-size sculptures, opting instead for miniature representations of people, animals and objects, Nickel said.

Several reasons could explain why the people stopped building these human-like statues, Nickel said. For instance, the skills involved in building these sculptures were complicated and, by the time Han rulers started building large tombs again, the people who had these skills could simply have died.

But there is another idea, one hinted at by the "heavenly taboo" recorded by Ban Gu that "disaster" happens when foreign models are followed recklessly. To the ancient Chinese, the 12 giant statues clad in foreign robes, and the Terracotta Warriors buried in pits, would have represented something unusual and foreign, Nickel said.

Read more at Discovery News

King of Greenhouse Gases Crowned: It's Not CO2

A chemical used in artificial blood and in the electronics industry traps more of the sun’s heat within the Earth’s atmosphere than any other gas known. Recent research discovered that the chemical, perfluorotributylamine (PFBTA), insulates the planet 7,100 times more effectively than carbon dioxide.

What’s more, nothing in nature absorbs or breaks down the chemical. That means PFBTA will still be insulating the planet centuries from now. Unlike PFBTA, many other greenhouse gases eventually disappear from the air. For example, plants absorb carbon dioxide and thereby reduce its quantity in the atmosphere.

“PFTBA is extremely long-lived in the atmosphere and it has a very high radiative efficiency; the result of this is a very high global warming potential,” said Angela Hong, of the University of Toronto and lead author of the study published in Geophysical Research Letters, in a press release. “Calculated over a 100-year time frame, a single molecule of PFTBA has the equivalent climate impact as 7100 molecules of CO2.”

Luckily, there isn’t much PFBTA in the atmosphere. Although the chemical has been used for decades, the air tested in the recent study contained only 0.18 parts per trillion PFBTA by volume. Other chemicals related to PFBTA may have a similar greenhouse effect, but have not yet been studied.

PFBTA once served as an ingredient in the artificial blood substitute, Fluosol, which is no longer used. PFBTA  continues to be used in electronics testing and as a heat transfer agent.

By recognizing that PFBTA has such a potential to trap heat, manufacturers can take steps to limit the escape of the gas into the environment. Currently, no laws regulate the release of PFBTA and similar chemicals. Now that chemists have identified the threat, legislators may find justification to control PFBTA pollution.

Read more at Discovery News

Dec 10, 2013

Astronomers Solve Temperature Mystery of Planetary Atmospheres

An atmospheric peculiarity Earth shares with Jupiter, Saturn, Uranus and Neptune is likely common to billions of planets, University of Washington astronomers have found, and knowing that may help in the search for potentially habitable worlds.

First, some history: It's known that air grows colder and thinner with altitude, but in 1902 a scientist named Léon Teisserenc de Bort, using instrument-equipped balloons, found a point in Earth's atmosphere at about 40,000 to 50,000 feet where the air stops cooling and begins growing warmer.

He called this invisible turnaround a "tropopause," and coined the terms "stratosphere" for the atmosphere above, and "troposphere" for the layer below, where we live -- terms still used today.

Then, in the 1980s, NASA spacecraft discovered that tropopauses are also present in the atmospheres of the planets Jupiter, Saturn, Uranus and Neptune, as well as Saturn's largest moon, Titan. And remarkably, these turnaround points all occur at roughly the same level in the atmosphere of each of these different worlds -- at a pressure of about 0.1 bar, or about one-tenth of the air pressure at Earth's surface.

Now, a paper by UW astronomer Tyler Robinson and planetary scientist David Catling published online Dec. 8 in the journal Nature Geoscience uses basic physics to show why this happens, and suggests that tropopauses are probably common to billions of thick-atmosphere planets and moons throughout the galaxy.

"The explanation lies in the physics of infrared radiation," said Robinson. Atmospheric gases gain energy by absorbing infrared light from the sunlit surface of a rocky planet or from the deeper parts of the atmosphere of a planet like Jupiter, which has no surface.

Using an analytic model, Catling, professor of Earth and space sciences, and Robinson, a postdoctoral researcher in astronomy, show that at high altitudes atmospheres become transparent to thermal radiation due to the low pressure. Above the level where the pressure is about 0.1 bar, the absorption of visible, or ultraviolet, light causes the atmospheres of the giant planets -- and Earth and Titan -- to grow warmer as altitude increases.

The physics, they write, provides a rule of thumb -- that the pressure is around 0.1 bar at the tropopause turnaround -- which should apply to the vast number of planetary atmospheres with stratospheric gases that absorb ultraviolet or visible light.

Astronomers could use the finding to extrapolate temperature and pressure conditions on the surface of planets and work out whether the worlds are potentially habitable -- the key being whether pressure and temperature conditions allow liquid water on the surface of a rocky planet.

"Then we have somewhere we can start to characterize that world," Robinson said. "We know that temperatures are going to increase below the tropopause, and we have some models for how we think those temperatures increase -- so given that leg up, we can start to extrapolate downward toward the surface."

Read more at Science Daily

Recipe for a Universe: Apply Heat and Stir

Apply heat and stir; an expanding universe can emerge in a remarkably simple way, say scientists at the Vienna University of Technology.

When soup is heated, it starts to boil. When time and space are heated, an expanding universe can emerge, without requiring anything like a "Big Bang." This phase transition between a boring empty space and an expanding universe containing mass has now been mathematically described by a research team at the Vienna University of Technology, together with colleagues from Harvard, the MIT and Edinburgh. The idea behind this result is a remarkable connection between quantum field theory and Einstein's theory of relativity.

A Cookbook for Spacetime

Everybody knows of the transitions between liquid, solid and gaseous phases. But also time and space can undergo a phase transition, as the physicists Steven Hawking and Don Page pointed out in 1983. They calculated that empty space can turn into a black hole at a specific temperature.

Can a similar process create a whole expanding universe such as ours? Daniel Grumiller from the Vienna University of Technology looked into this, together with colleagues from the USA and Great Britain. Their calculations show that there is indeed a critical temperature at which an empty, flat spacetime turns into an expanding universe with mass. "The empty spacetime starts to boil, little bubbles form, one of which expands and eventually takes up all of spacetime," explains Grumiller.

For this to be possible, the universe has to rotate -- so the recipe for creating the universe is "apply heat and stir." However, the required rotation can be arbitrarily small. In a first step, a spacetime with only two spatial dimensions was considered. "But there is no reason why the same should not be true for a universe with three spatial dimensions," says Grumiller.

Looking for the Structure of the Universe

Our own universe does not seem to have come into existence this way. The phase-transition model is not meant to replace the theory of the Big Bang. "Today, cosmologists know a lot about the early universe -- we are not challenging their findings. But we are interested in the question, which phase transitions are possible for time and space and how the mathematical structure of spacetime can be described" says Grumiller.

The new theory is the logical next step after the so called "AdS-CFT correspondence," a conjecture put forward in 1997, which has strongly influenced fundamental physics research ever since. It describes a peculiar connection between theories of gravity and quantum field theories -- two areas which, at first glance, do not have much in common. In certain limiting cases, according to AdS-CFT correspondence, statements from quantum field theories can be translated into statements concerning gravitational theories and vice versa. This is almost as surprising as the idea of making statements about a stone falling to the ground by actually calculating the temperature of a hot gas. Two completely different areas are being connected -- but it works.

In this kind of correspondence, the quantum field theory is always described in one fewer dimension than the gravitational theory. This is called "holographic principle." Similar to a two dimensional hologram which can depict a three dimensional object, a quantum field theory with two spatial dimensions can describe a physical situation in three spatial dimensions.

A Correspondence Principle for Flat Spacetimes

To do this, the gravitational calculations usually have to be done in an exotic kind of geometry -- in so-called "Anti-de-Sitter-spaces," which are quite different from the flat geometry we are used to. However, it has been suspected for a while, that there may be a similar version of the "holographic principle" for flat spacetimes. But for a long time there haven't been any models showing this.

Read more at Science Daily

Sea Life Thriving in Chemical Weapons Dump

The Pacific Ocean hides chemical weapons, such as mustard gas, dumped after World War II. The Monterey Bay Aquarium Research Institute (MBARI) recently documented one of these dumps using diving robots.

The MBARI mission found rusting 55-gallon drums filled with unknown substances, but no artillery shells. Instead of instruments of death, the chemical weapons dump sites harbored life, including sponges, crabs and anemones. The animals clung to the sides of the barrels filled with unknown substances.

The survey mission started in March of 2012 when a aquatic drone, known as an autonomous underwater vehicle, discovered 754 objects embedded in the muddy sea floor south of Santa Cruz Island and west of the Los Angeles coast. The deepsea drone used sonar to map the location of the objects, but couldn’t provide detailed information about their identity. In May, a remote-operated vehicle, named Doc Ricketts, videotaped the seafloor, which allowed identification of the barrels and other items.

The MBARI exploration found sea shells, as opposed to artillery shells, but that doesn’t mean marine chemical weapons dumps don’t threaten humans and wildlife. Nautical charts identify 32 chemical weapons dumping grounds in U.S. waters. Some of these areas cover vast expanses of seafloor and provide few details about the nature or exact location of the munitions, according to MBARI researchers who presented their findings at this week’s meeting of the American Geophysical Union.

In 1997, the Chemical Weapons Convention banned the production, storage and use of horrific chemical agents in 188 nations. Prior to 1997, many nations had already condemned and abandoned the use of chemicals such as blister-causing sulfur mustard or the nerve poison sarin. After World War I and II, large numbers of toxin-filled artillery shells and other weapons were dumped into the sea.

Now however, the discarded weapons cause injuries when fishermen dredge up decades-old munitions. For example, the Centers for Disease Control noted three cases from the Atlantic Coast in the past decade:

For example, in 2010, commercial fishermen pulled munitions from the Atlantic while dredging for clams off Long Island, New York. Two crew members were hospitalized after a black tarry substance oozed from the weapons.

Read more at Discovery News

Coldest Places on Earth Found - In Antarctica

Where is the coldest temperature ever measured on Earth?

"It's in Antarctica of course," Ted Scambos, lead scientist at the National Snow and Ice Data Center in Boulder, Colo., said here today (Dec. 9) at the annual meeting of the American Geophysical Union.

That temperature? A mind- — and body-numbing — minus 136 degrees Fahrenheit (minus 93.2 Celsius), measured in pockets scattered near a high ice ridge between Dome Argus and Dome Fuji, two summits on the East Antarctic Plateau.

The temperature measurement came from the most detailed global surface-temperature maps made to date, which were created using data from the new Landsat 8 satellite, launched in February, and 32 years' worth of data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA's Terra and Aqua satellites and instruments aboard several other satellites.

Researchers began looking at these frigid pockets after they noticed cracks in the snow between large snow dunes on the plateau and wondered if super low temperatures might be creating the cracks by causing the snow on the surface to shrink. This led them to begin the search for the coldest places on the planet.

Cold, colder, coldest

They turned to the temperature records from the satellites, whose instruments measure the thermal radiation emitted at Earth's surface. The coldest temperature they found occurred on Aug. 10, 2010 (winter in the Southern Hemisphere). The temperature is essentially the same "as if you were to take your hand and put it on the surface of the snow. I don't recommend that, as, in this case, that would be colder than dry ice," Scambos said. It's "50 degrees colder than anything that has ever been seen in Alaska, or Siberia," he added.

The temperatures in these pockets are able to drop so very, very low thanks to a combination of circumstances. Scambos and his colleagues think the stage is set for these record lows when clear skies above the domes cause the air to get colder as it radiates heat away to space. As the air near the Earth's surface gets colder, it also gets denser, and begins sliding down the dome, until it encounters one of these pockets, where it can become stuck. As it sits there possibly over several days, the air keeps radiating away heat and becomes colder and colder, until it reaches the record lows observed by the satellites.

The researchers think the air gets stuck on its way down the dome and toward the coast of the continent when atmospheric patterns conspire to "try to push the air back uphill," Scambos said.

Interestingly, the coldest temperatures measured in these pockets were all within a degree or two of each other, suggesting a potential floor to just how low the temperature can go.

"It's surprising that all of those places would have so similar a record," Scambos said.

The similarity could be explained in a few ways, he said: Thin clouds that form in the Earth's stratosphere (the layer of the atmosphere above the one humans live in and in which most weather occurs) could be limiting how much heat the air is able to radiate away into space. Or it could be that the weather systems that block the air only last for so long, among other possibilities.

Scambos and his team are planning to use Landsat 8's capabilities to examine the surface with a higher resolution than previous satellites to better understand the cold pockets and to nail down more accurately the exact temperatures reached in them.

No official record

The temperatures won't make it into the official record books though, since the World Meteorological Organization recognizes only temperatures made a couple of meters above the surface. The long-standing record for the coldest temperature by that measure was, of course, also in Antarctica, at the Vostok Research Station, where it reached minus 128.6 F (minus 89.2 C) in July 1983.

Read more at Discovery News

Green Lightning Revealed in Volcanic Eruption

Lightning researcher Arthur Few says he had probably looked at the two images of the May 3, 2008, volcanic lightning storm dozens of times before he noticed it: weird green channels of lightning. The volcano was Chaiten in Chile, which produced a spectacular light show caught by photographer Carlos Gutierrez.

“Has anyone here seen green lightning before?,” Few asked reporters gathered to learn about his discovery on Monday at the meeting of the American Geophysical Union (AGU) in San Francisco. No one had, including me, which is why I was keen on getting Few to present his discovery and hypothesis about its cause to the media at the meeting (Full disclosure: in addition to writing for Discovery News, I freelance for AGU and helped them comb through the scientific program and find good stuff for press conferences).

Few, a professor emeritus at Rice University, thinks that green lightning is not really that unusual, but is perhaps hidden inside of regular thunderstorms. But the gigantic column of ash that was launched by Chaiten wore its green lightning on its sleeve, and Few wants to know why.

“What else do we have in the atmosphere that’s green?,” Few asked. One is the northern lights, or aurora, which glow green, red and white when electrons rain down from space and excite oxygen atoms, he said. Above 100 kilometers, the aurora are green. Higher up they are red.

“My working hypothesis is that the green ones are actually streamers,” Few said. A streamer is a lightning bolt that is effectively “a positive channel being pulled to a negative charge” higher up in the ash cloud.

The mess of white lightning in the Chaiten image is the negative charges being generated throughout the cloud raining down and curving into the bottom of the ash cloud. And there is the positive green channel, or streamer, reversing the flow.

Read more at Discovery News

Dec 9, 2013

Hidden Details Revealed in Nearby Starburst Galaxy

Using the new, high-frequency capabilities of the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT), astronomers have captured never-before-seen details of the nearby starburst galaxy M82. These new data highlight streamers of material fleeing the disk of the galaxy as well as concentrations of dense molecular gas surrounding pockets of intense star formation.

M82, which is located approximately 12 million light-years away in the constellation Ursa Major, is a classic example of a starburst galaxy -- one that is producing new stars tens- to hundreds-of-times faster than our own Milky Way. Its relatively nearby location made it an ideal target for the GBT's newly equipped "W-Band" receiver, which is capable of detecting the millimeter wavelength light that is emitted by molecular gas. This new capability makes the GBT the world's largest single-dish, millimeter-wave telescope.

"With this new vision, we were able to look at M82 to explore how the distribution of molecular gas in the galaxy corresponded to areas of intense star formation," said Amanda Kepley, a post-doctoral fellow at the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virginia, and lead author on a paper accepted for publication in the Astrophysical Journal Letters. "Having this new capability may help us understand why stars form where they do."

Astronomers recognize that dense molecular gas goes hand-in-hand with areas of star formation, but the connection is poorly understood and this relationship may be different in different types of galaxies. By creating wide-angle maps of the gas in galaxies, astronomers hope to better understand this complex interplay.

To date, however, these kinds of observations have not been easy since molecules that are used to map the distribution of dense gas, like HCN (hydrogen cyanide) and HCO+ (formylium), shine feebly in millimeter light. With its new W-Band receiver, the GBT was able to make highly sensitive, wide-angle images of these gases in and around M82.

"The GBT data clearly show billowing concentrations of dense molecular gas huddled around areas that are undergoing bursts of intense star formation," said Kepley. "They also reveal giant outflows of ionized gas fleeing the disk of the galaxy. These outflows are driven by star formation deep within the galaxy."

This capability will enable astronomers to quickly survey entire galaxies and different parts within galaxies. Such surveys would complement higher resolution observations with new Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile.

Read more at Science Daily

Cold-Loving Cockroach Invades New York

A new species of cockroach that can withstand freezing temperatures has taken up residence in New York, scientists confirmed.

The resilient critter, Periplaneta japonica, had never been seen in the United States until an exterminator spotted some strange-looking roach carcasses last year on the High Line, a mile-long park built on an old elevated railway in Manhattan. Researchers confirmed the identity of the species, which is native to Asia and notable for its ability to thrive in cold climates, unlike the American cockroaches that populate New York and take shelter indoors when winter comes.

"About 20 years ago colleagues of ours in Japan reared nymphs of this species and measured their tolerance to being able to survive in snow," Rutgers insect biologist Jessica Ware said in a statement. "As the species has invaded Korea and China, there has been some confirmation that it does very well in cold climates, so it is very conceivable that it could live outdoors during winter in New York. That is in addition to its being well suited to live indoors alongside the species that already are here."

Ware and colleagues say it will be difficult to trace the source of the species, but they suspect Periplaneta japonica arrived in New York in the soil of one of the plants along the High Line, which first opened in 2009 and is still partially under construction. Though the High Line's gardens have a focus on native plants, Ware noted that many nurseries in the United States have native plants alongside imported ones.

"If we discover more populations in the U.S., we could trace their genes back to try to figure out their exact sources," Rutgers doctoral student Dominic Evangelista added in a statement.

It may be too soon to predict the impact of the species' arrival, but the researchers say the cockroaches are unlikely to be major nuisances in the Big Apple.

"Because this species is very similar to cockroach species that already exist in the urban environment, they likely will compete with each other for space and for food," said Evangelista. Ware added that their numbers inside buildings could actually drop if they start spending more time and energy competing with each other instead of reproducing.

And there's a chance that grime could be on New Yorkers' side. The Asian researchers only studied Periplaneta japonica in clean snow, Ware noted, saying, "I don't know how well it would do in dirty New York snow."

As for an Asian-American hybrid super-roach, the researchers said the possibility is unlikely.

Read more at Discovery News

Weather at Tolkien's Middle Earth Mapped

J.R.R. Tolkien created a masterfully detailed world in his classic Lord of the Rings trilogy, right down to the topography and languages. Now a British climate researcher who might have too much time on his hands has plugged Tolkien’s maps into a supercomputer and predicted weather patterns for Middle Earth.

Dan Lunt, a scientist at the University of Bristol who specializes in climate modeling research, decided to put the Advanced Computing Research Center’s supercomputer to a dorktastic test. Lunt took Tolkien’s detailed maps of Middle Earth showing continents and mountains, and essentially “scanned” them into the supercomputer, the Guardian reported. Then he ran the numbers to get a 70-year model.

In a mock research paper published under the name Radagast the Brown, Lunt details climate details and weather predictions for Tolkien’s fictional world. He compared the climate surrounding Mount Doom in the heart of Mordor to that of Los Angeles and western Texas. I mean, obviously. But Lunt argued that those areas have dry, hot climates with little vegetation and therefore match the conditions in fictional Mordor.

Lunt also concluded that the Shire’s climate would have been close to that of real UK “shires” Lincolnshire or Leicestershire. Other insights: “The climate of Middle Earth has a similar distribution to that of Western Europe and North Africa” and “Ships sailing for the Undying Lands in the West set off from the Grey Havens due to the prevailing winds in that region.”

Dwarfs and elves can read the mock paper, too. Lunt translated it for them here and here. That’s a true LOTR fan. I obviously can’t speak for the man, but imagine Tolkien would approve of this level of dedication.

Plugging fictitious data into reality-based computer interfaces is incredibly tempting. Anyone else remember that Google Maps gem that came up when asking for walking directions to Mordor? Heck, if I had access to that University of Bristol supercomputer I’d probably do similar number crunching.

Read more at Discovery News

Mars Rover Finds Ancient Life-Supporting Lakebed

The site where NASA’s Mars rover Curiosity landed last year contains at least one lake that would have been perfectly suited for colonies of simple, rock-eating microbes found in caves and hydrothermal vents on Earth.

Analysis of mudstones in an area known as Yellowknife Bay, located inside the rover’s Gale Crater landing site, show that fresh water pooled on the surface for tens of thousands -- or even hundreds of thousands -- of years.

“The results show that the lake was definitely a habitable environment,” Curiosity lead scientist John Grotzinger, with the California Institute of Technology, told Discovery News.

The really big surprise, however, was that clays drilled out from inside two mudstones and analyzed by the rover are much younger than scientists expected, a finding that extends the window of time for when Mars may have been suitable for life.

“These numbers now overlap with the oldest rocks on Earth that contain evidence of a former biosphere on Earth,” Grotzinger said.

The rover explored Yellowknife Bay before heading toward a three-mile high mountain of layered sediments rising from the floor of Gale Crater known at Mount Sharp.

Curiosity landed in August 2012 to assess if Gale Crater had the right ingredients and environments to support ancient microbial life. Within six months, scientists had the answer to that question: Yes.

Now, in addition to characterizing specific potential habitats, scientists are coming up with a search strategy to determine which sites hold the most promise for finding organic carbon, a far more difficult and complex challenge and the focus of future studies at Mount Sharp.

“Habitability only requires that the chemicals and minerals in the rock preserve evidence of an ancient environment. To search for organic carbon you’re actually looking for particular material ... that is not really compatible with the present environment of Mars. To find something you need a guidebook, you need some rules,” Grotzinger said.

One of those rules involves how much radiation a rock has been exposed to. Mars today has only has a thin atmosphere and no protective magnetic field, so scientists have been thinking they will need to dig deep to find carbon-laced samples, or they will have to probe craters relatively recently excavated by an impact.

Analysis of the Yellowknife Bay rocks points to another path. Dating the ages of the rocks’ surfaces show they are as young as about 70 million years, the result of being sand-blasted by Martian winds.

“In the future, if we find a rock that looks like a place where organics were accumulating and if it looks like the chemistry would have been favorable for preservation ... we can now very deliberately manage the risk that the rock would have been cooking away in the presence of radiation for hundreds of millions of years by looking for these scarps, these miniature cliffs, and then drilling the rock and date it to see how long it’s been laying around,” Grotzinger said.

Read more at Discovery News

Dec 8, 2013

Electrical Control of Single Atom Magnets

The energy needed to change the magnetic orientation of a single atom -- which determines its magnetic stability and therefore its usefulness in a variety of future device applications -- can be modified by varying the atom's electrical coupling to nearby metals.

This striking result was published today in the journal Nature Nanotechnology by an international group of scientists working at the London Centre for Nanotechnology (LCN) at UCL (UK), the Iberian Nanotechnology Laboratory (Portugal), the University of Zaragoza (Spain), and the Max Planck Institute of Microstructure Physics (Germany).

Anyone playing with two magnets can experience how they repel or attract each other depending on the relative orientation of their magnetic poles. The fact that in a given magnet these poles lie along a specific direction rather than being randomly oriented is known as magnetic anisotropy, and this property is exploited in a variety of applications ranging from compass needles to hard drives.

"For 'large' pieces of magnetic material," emphasized Dr Joaquín Fernández-Rossier from the INL, "magnetic anisotropy is determined primarily by the shape of a magnet. The atoms that form the magnetic material are also magnetic themselves, and therefore have their own magnetic anisotropy. However, atoms are so small that it is hardly possible to ascribe a shape to them, and the magnetic anisotropy of an atom is typically controlled by the position and charge of the neighbouring atoms."

Using a scanning tunnelling microscope, an instrument capable of observing and manipulating an individual atom on a surface, LCN researchers and their colleagues discovered a new mechanism that controls magnetic anisotropy at the atomic scale.

In their experiment, the research team observed dramatic variations in the magnetic anisotropy of individual cobalt atoms depending on their location on a copper surface capped with an atomically-thin insulating layer of copper nitride.

These variations were correlated with large changes in the intensity of another phenomenon -- the Kondo effect -- that arises from electrical coupling between a magnetic atom and a nearby metal. With the help of theoretical and computational modelling performed in Germany and Portugal, the researchers found that, in addition to the conventional structural mechanisms, the electronic interactions between the metal substrate and the magnetic atom can also play a major role in determining magnetic anisotropy.

"Electrical control of a property that formerly could only be tuned through structural changes will enable significant new possibilities when designing the smallest possible devices for information processing, data storage, and sensing," said LCN researcher Dr Cyrus Hirjibehedin.

Read more at Science Daily

Surprising Diversity in Aging Revealed in Nature

In our youth we are strong and healthy and then we weaken and die -- that's probably how most would describe what aging is all about. But, in nature, the phenomenon of aging shows an unexpected diversity of patterns and is altogether rather strange, conclude researchers from The University of Southern Denmark.

Not all species weaken and become more likely to die as they age. Some species get stronger and less likely to die with age, while others are not affected by age at all. Increasing weakness with age is not a law of nature.

Researchers from the University of Southern Denmark have studied aging in 46 very different species including mammals, plants, fungi and algae, and they surprisingly find that there is a huge diversity in how different organisms age. Some become weaker with age -- this applies to e.g. humans, other mammals, and birds; others become stronger with age -- this applies to e.g. tortoises and certain trees, and others become neither weaker nor stronger -- this applies to e.g. Hydra, a freshwater polyp.

"Many people, including scientists, tend to think that aging is inevitable and occurs in all organisms on Earth as it does for humans: that every species becomes weaker with age and more likely to die. But that is not the case," says evolutionary biologist and assistant professor Owen Jones from the Max-Planck Odense Center at the University of Southern Denmark .

He is the lead author of an article on the subject in the scientific journal Nature. Other authors are from the Max Planck Institute for Demographic Research in Rostock, Germany, the University of Queensland in Australia, University of Amsterdam in Holland and elsewhere.

Owen Jones and his colleagues studied aging in species ranging from oak trees, nematodes, baboons and lice to seaweed and lions. The species included 11 mammals, 12 other vertebrates, 10 invertebrates, 12 plants and one algae.

"The diversity of mortality and fertility patterns in these organisms surprised us, and there is clearly a need for more research before we fully understand the evolutionary causes of aging and become better able to address problems of aging in humans," says Owen Jones.

He points out that while there is plenty of scientific data on aging in mammals and birds, there is only sparse and incomplete data on aging in other groups of vertebrates, and most invertebrates, plants, algae, and fungi.

For several species mortality increases with age -- as expected by evolutionary scientists. This pattern is seen in most mammal species including humans and killer whales, but also in invertebrates like water fleas. However, other species experience a decrease in mortality as they age, and in some cases mortality drops all the way up to death. This applies to species like the desert tortoise (Gopherus agassizii) which experiences the highest mortality early on in life and a steadily declining mortality as it ages. Many plant species, e.g. the white mangrove tree (Avicennia marina) follow the same pattern.

Amazingly, there are also species that have constant mortality and remain unaffected by the aging process. This is most striking in the freshwater polyp Hydra magnipapillata which has constant low mortality. In fact, in lab conditions, it has such a low risk of dying at any time in its life that it is effectively immortal.

"Extrapolation from laboratory data show that even after 1400 years five per cent of a hydra population kept in these conditions would still be alive," says Owen Jones.

Several animal and plant species show remarkably little change in mortality throughout their life course. For example, these include rhododendron (Rhododendron maximum), great tit (Parus major), hermit crab (Pagurus longicarpus), common lizard (Lacerta vivapara), collared flycatcher (Ficedula albicollis), viburnum plants (Viburnum furcatum ), oarweed (Laminaria digitata), red abalone (Haliotis rufescens), the plant armed saltbush (Atriplex acanthocarpa), red-legged frog (Rana aurora) and the coral red gorgonian (Paramuricea clavata).

When you look at the fertility patterns of the 46 surveyed species, there is also a great diversity and some large departures from the common beliefs about aging. Human fertility is characterized by being concentrated in a relatively short period of life, and by the fact that humans live for a rather long time both before and after the fertile period.

A similar pattern of a concentrated fertile period is also seen in other mammals like killer whales, chimpanzees, and chamois (Rupicapra rupicapra), and also in birds like sparrow hawks (Accipiter nisus).

However, there are also species that become more and more fertile with age, and this pattern is especially common in plants such as the agave (Agave marmorata) and the rare mountain plants hypericum (Hypericum cumulicola) and borderea (Borderea pyrenaica).

On the contrary fertility occurs very early in the nematode worm Caenorhabditis elegans. Actually this species starts its life with being fertile, then it quite quickly and quite suddenly loses the ability to produce offspring.

Read more at Science Daily