Oct 1, 2016

VR Glove Makes Virtual Objects Feel Real

A new virtual reality glove promises to solve an enduring problem in the world of VR -- actually feeling what you touch.

The Dexmo glove, designed by a team of Chinese and European roboticists, uses a miniaturized force-feedback solution to let users grasp and hold items in virtual reality. Unlike other VR gloves that use vibration motors or electrodes for feedback, the Dexmo employs a mechanical system that applies varying degrees of torque to the fingers.

The glove's resistance is strong enough, in fact, that it will physically prevent your fingers from passing through "solid" object in virtual reality -- a wall, say. According to the designers at Dexta Robotics, this provides a greater level of immersion than is possible with competing technologies. While other force-feedback systems have been applied to VR gloves, the Dexmo developers are aiming to create a lightweight, inexpensive battery-powered device for consumers and VR enthusiasts.

With an actual mechanical system pulling back on your fingers, an obvious question presents itself -- could the glove cause harm to your hand? Not a problem, say the designers: The maximum force feedback on each individual finger module is limited to less than half the average torque that a human finger can generate, according to the FAQ. If you really want to put your finger through that wall, you can.

The glove can also provide a sensation of relative stiffness when handling virtual items. Grab a billiard ball, for instance, and it will feel different than a tennis ball. The glove even enables a user to feel "squishiness" -- a sponge will feel like a sponge, and not a brick. It achieves this effect by way of proprietary algorithms that dynamically alter the direction and magnitude of applied force depending on the virtual object.

Besides the force-feedback system, tiny fingertip motors generate vibrations that can approximate tapping on an object or running your fingers over a rough surface. The glove has gone through more than 20 iterations so far and battery life is up to about four hours under normal usage.

The design team is currently working with early adopters and software developers, so you won't see the glove on shelves anytime soon. However, the device is designed to be fully compatible with existing VR systems like Oculus Rift and HTC Vive. The Dexmo team also hopes to get into the virtual training market, providing gloves for engineers, mechanics and even surgeons to train in the virtual realm.

From Discovery News

Fish Fossil 3-D Print May Hold Clues on Teeth Origins

Shown is an enlarged 3-D print of the jaw and tooth-like denticles of the ancient fish fossil.
A 400-million-year-old fish fossil from Australia may hold fresh clues about the evolution of teeth.

Writing in the journal Biology Letters, a team of scientists from Australian National University (ANU) and Queensland Museum describe their work using micro-CT scanning and 3-D printing to create three-dimensional prints of the jaws of Buchanosteus, an armored fish in an extinct class called placoderms.

Study co-author Yuzhi Hu, an ANU researcher, called the evolutionary origins of teeth a major and still open question. "We are researching this question using new evidence from an exceptionally preserved fossil fish," she said in a statement.

Buchanosteus is a common focus of research into the origins of teeth, the researchers say.
The ANU authors, alongside Queensland Museum researcher Carole Burrow, argued against findings in an earlier paper that concluded that placoderms had real teeth.

"We are conducting further research on the internal tissue structure of tooth-like denticles in the mouth of the fish fossil, to determine whether they represent a transitional stage in the evolution of teeth," explained Gavin Young, ANU researcher and co-author of the study.

The team said its findings could help answer the questions of when and how teeth first appeared in evolutionary history.

From Discovery News

Sep 30, 2016

NASA's Fermi finds record-breaking binary in galaxy next door

LMC P3 (circled) is located in a supernova remnant called DEM L241 in the Large Magellanic Cloud, a small galaxy about 163,000 light-years away. The system is the first gamma-ray binary discovered in another galaxy and is the most luminous known in gamma rays, X-rays, radio waves and visible light.
Using data from NASA's Fermi Gamma-ray Space Telescope and other facilities, an international team of scientists has found the first gamma-ray binary in another galaxy and the most luminous one ever seen. The dual-star system, dubbed LMC P3, contains a massive star and a crushed stellar core that interact to produce a cyclic flood of gamma rays, the highest-energy form of light.

"Fermi has detected only five of these systems in our own galaxy, so finding one so luminous and distant is quite exciting," said lead researcher Robin Corbet at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Gamma-ray binaries are prized because the gamma-ray output changes significantly during each orbit and sometimes over longer time scales. This variation lets us study many of the emission processes common to other gamma-ray sources in unique detail."

These rare systems contain either a neutron star or a black hole and radiate most of their energy in the form of gamma rays. Remarkably, LMC P3 is the most luminous such system known in gamma rays, X-rays, radio waves and visible light, and it's only the second one discovered with Fermi.

A paper describing the discovery will appear in the Oct. 1 issue of The Astrophysical Journal and is now available online.

LMC P3 lies within the expanding debris of a supernova explosion located in the Large Magellanic Cloud (LMC), a small nearby galaxy about 163,000 light-years away. In 2012, scientists using NASA's Chandra X-ray Observatory found a strong X-ray source within the supernova remnant and showed that it was orbiting a hot, young star many times the sun's mass. The researchers concluded the compact object was either a neutron star or a black hole and classified the system as a high-mass X-ray binary (HMXB).

In 2015, Corbet's team began looking for new gamma-ray binaries in Fermi data by searching for the periodic changes characteristic of these systems. The scientists discovered a 10.3-day cyclic change centered near one of several gamma-ray point sources recently identified in the LMC. One of them, called P3, was not linked to objects seen at any other wavelengths but was located near the HMXB. Were they the same object?

To find out, Corbet's team observed the binary in X-rays using NASA's Swift satellite, at radio wavelengths with the Australia Telescope Compact Array near Narrabri and in visible light using the 4.1-meter Southern Astrophysical Research Telescope on Cerro Pachón in Chile and the 1.9-meter telescope at the South African Astronomical Observatory near Cape Town.

The Swift observations clearly reveal the same 10.3-day emission cycle seen in gamma rays by Fermi. They also indicate that the brightest X-ray emission occurs opposite the gamma-ray peak, so when one reaches maximum the other is at minimum. Radio data exhibit the same period and out-of-phase relationship with the gamma-ray peak, confirming that LMC P3 is indeed the same system investigated by Chandra.

"The optical observations show changes due to binary orbital motion, but because we don't know how the orbit is tilted into our line of sight, we can only estimate the individual masses," said team member Jay Strader, an astrophysicist at Michigan State University in East Lansing. "The star is between 25 and 40 times the sun's mass, and if we're viewing the system at an angle midway between face-on and edge-on, which seems most likely, its companion is a neutron star about twice the sun's mass." If, however, we view the binary nearly face-on, then the companion must be significantly more massive and a black hole.

Both objects form when a massive star runs out of fuel, collapses under its own weight and explodes as a supernova. The star's crushed core may become a neutron star, with the mass of half a million Earths squeezed into a ball no larger than Washington, D.C. Or it may be further compacted into a black hole, with a gravitational field so strong not even light can escape it.

The surface of the star at the heart of LMC P3 has a temperature exceeding 60,000 degrees Fahrenheit (33,000 degrees Celsius), or more than six times hotter than the sun's. The star is so luminous that pressure from the light it emits actually drives material from the surface, creating particle outflows with speeds of several million miles an hour.

In gamma-ray binaries, the compact companion is thought to produce a "wind" of its own, one consisting of electrons accelerated to near the speed of light. The interacting outflows produce X-rays and radio waves throughout the orbit, but these emissions are detected most strongly when the compact companion travels along the part of its orbit closest to Earth.

Through a different mechanism, the electron wind also emits gamma rays. When light from the star collides with high-energy electrons, it receives a boost to gamma-ray levels. Called inverse Compton scattering, this process produces more gamma rays when the compact companion passes near the star on the far side of its orbit as seen from our perspective.

Prior to Fermi's launch, gamma-ray binaries were expected to be more numerous than they've turned out to be. Hundreds of HMXBs are cataloged, and these systems are thought to have originated as gamma-ray binaries following the supernova that formed the compact object.

"It is certainly a surprise to detect a gamma-ray binary in another galaxy before we find more of them in our own," said Guillaume Dubus, a team member at the Institute of Planetology and Astrophysics of Grenoble in France. "One possibility is that the gamma-ray binaries Fermi has found are rare cases where a supernova formed a neutron star with exceptionally rapid spin, which would enhance how it produces accelerated particles and gamma rays."

Read more at Science Daily

Curiosity finds evidence of Mars crust contributing to atmosphere

Processes in Mars' surface material can explain why particular xenon (Xe) and krypton (Kr) isotopes are more abundant in the Martian atmosphere than expected, as measured by NASA's Curiosity rover. Cosmic rays striking barium (Ba) or bromine (Br) atoms can alter isotopic ratios of xenon and krypton.
NASA's Curiosity rover has found evidence that chemistry in the surface material on Mars contributed dynamically to the makeup of its atmosphere over time. It's another clue that the history of the Red Planet's atmosphere is more complex and interesting than a simple legacy of loss.

The findings come from the rover's Sample Analysis at Mars, or SAM, instrument suite, which studied the gases xenon and krypton in Mars' atmosphere. The two gases can be used as tracers to help scientists investigate the evolution and erosion of the Martian atmosphere. A lot of information about xenon and krypton in Mars' atmosphere came from analyses of Martian meteorites and measurements made by the Viking mission.

"What we found is that earlier studies of xenon and krypton only told part of the story," said Pamela Conrad, lead author of the report and SAM's deputy principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "SAM is now giving us the first complete in situ benchmark against which to compare meteorite measurements."

Of particular interest to scientists are the ratios of certain isotopes -- or chemical variants -- of xenon and krypton. The SAM team ran a series of first-of-a-kind experiments to measure all the isotopes of xenon and krypton in the Martian atmosphere. The experiments are described in a paper published in Earth and Planetary Science Letters.

The team's method is called static mass spectrometry, and it's good for detecting gases or isotopes that are present only in trace amounts. Although static mass spectrometry isn't a new technique, its use on the surface of another planet is something only SAM has done.

Overall, the analysis agreed with earlier studies, but some isotope ratios were a bit different than expected. When working on an explanation for those subtle but important differences, the researchers realized that neutrons might have gotten transferred from one chemical element to another within the surface material on Mars. The process is called neutron capture, and it would explain why a few selected isotopes were more abundant than previously thought possible.

In particular, it looks as if some of the barium surrendered neutrons that got picked up by xenon to produce higher-than-expected levels of the isotopes xenon-124 and 126. Likewise, bromine might have surrendered some of its neutrons to produce unusual levels of krypton-80 and krypton-82.

These isotopes could have been released into the atmosphere by impacts on the surface and by gas escaping from the regolith, which is the soil and broken rocks of the surface.

"SAM's measurements provide evidence of a really interesting process in which the rock and unconsolidated material at the planet's surface have contributed to the xenon and krypton isotopic composition of the atmosphere in a dynamic way," said Conrad.

The atmospheres of Earth and Mars exhibit very different patterns of xenon and krypton isotopes, particularly for xenon-129. Mars has much more of it in the atmosphere than does Earth.

Read more at Science Daily

Final descent image from Rosetta spacecraft

The OSIRIS narrow-angle camera aboard the Space Agency's Rosetta spacecraft captured this image of comet 67P/Churyumov-Gerasimenko on September 30, 2016, from an altitude of about 10 miles (16 kilometers) above the surface during the spacecraft's controlled descent. The image scale is about 12 inches (30 centimeters) per pixel and the image itself measures about 2,000 feet (614 meters) across.
A new image of comet 67P/Churyumov-Gerasimenko was taken by the European Space Agency's (ESA) Rosetta spacecraft shortly before its controlled impact into the comet's surface on Sept. 30, 2016. Confirmation of the end of the mission arrived at ESA's European Space Operations Center in Darmstadt, Germany, at 4:19 a.m. PDT (7:19 a.m. EDT / 1:19 p.m. CEST) with the loss of signal upon impact.

The final descent gave Rosetta the opportunity to study the comet's gas, dust and plasma environment very close to its surface, as well as take very high-resolution images.

The image was taken from an altitude of 167 feet (51 meters) above the comet's surface by the spacecraft's OSIRIS wide-angle camera on Sept. 30.?The image scale is about two-tenths of an inch (5 millimeters) per pixel. The image measures about 9 feet (2.4 meters) across.

The decision to end the mission on the surface is a result of Rosetta and the comet heading out beyond the orbit of Jupiter again. Farther from the sun than Rosetta had ever journeyed before, there would be little power to operate the craft. Mission operators were also faced with an imminent month-long period when the sun is close to the line-of-sight between Earth and Rosetta, meaning communications with the craft would have become increasingly more difficult.

The European Space Agency's Rosetta mission was launched in 2004 and arrived at comet 67P/Churyumov-Gerasimenko on Aug. 6, 2014. It is the first mission in history to rendezvous with a comet and escort it as it orbits the sun. On Nov. 4, 2014, a smaller lander name Philae, which had been deployed from the Rosetta mothership, touched down on the comet and bounced several times before finally alighting on the surface. Philae obtained the first images taken from a comet's surface and sent back valuable scientific data for several days.

U.S. contributions aboard the Rosetta spacecraft are the Microwave Instrument for Rosetta Orbiter (MIRO); the Alice spectrograph; the Ion and Electron Sensor (IES), part of the Rosetta Plasma Consortium Suite; and the Double Focusing Mass Spectrometer (DFMS) electronics package for the Rosetta Orbiter Spectrometer for Ion Neutral Analysis (ROSINA). They are part of a suite of 11 total science instruments aboard Rosetta.

Comets are time capsules containing primitive material left over from the epoch when the sun and its planets formed. Rosetta is the first spacecraft to witness at close proximity how a comet changes as it is subjected to the increasing intensity of the sun's radiation. Observations will help scientists learn more about the origin and evolution of our solar system and the role comets may have played in the formation of planets.

Read more at Science Daily

Feral chickens spread light on evolution

Hybrid chickens.
Different genes are involved during the adaptation of a domestic animal to life in the wild than when a wild animal becomes domesticated. This is the conclusion of a study led by a researcher at Linköping University in Sweden and published in the journal Nature Communications. The results increase our understanding of what happens as a species evolves.

"There are large differences between tame chickens and wild ones. Studying the differences in their genetic material can teach us more about how genes influence animal appearance and behaviour. Although a lot is known about how we tame and domesticate animals, very little is known about the reverse, when domestic animals go back to the wild. We have examined this process at the genetic level when tame chickens are released into the wild," says researcher Dominic Wright, who has led the study.

For many thousands of years, humans have bred dogs, goats, chickens and other animals to make them suitable for use as domestic animals, in a process known as domestication. Humans have selected the individuals that possess desirable traits and bred them with similar individuals, such that the offspring possess the same traits. The genetic material of the animal has partially changed during the development of the species from its wild form to a domesticated one. The opposite process also takes place, when domesticated animals readapt to life in the wild, in a process known as feralization. By investigating what happens in an animal's genetic material, we can study whether the effects of domestication by humans are long-term or short-term. Can evolution go backwards?

"We wanted to see whether feralization is the same process as domestication, but in the other direction. Our results show that this is not the case. It is largely separate genes that are affected when domesticated chickens return to the wild," says Dominic Wright.

Two tropical storms on the island of Kauai in Hawaii 30 years ago contributed to domesticated chickens being released into the wild. On the island, there was an existing group of wild Red Junglefowl, and the domesticated chickens interbred with these. The chickens now living wild on Kauai have inherited genetic material from both domesticated chickens and wild Red Junglefowl.

Life in freedom brings with it greater threats from predators and disease, but it means that a chicken can choose freely who to mate with. Traits that make an individual attractive, such as an impressive comb, play a role in the selection of partners.

"Sexual selection is important in wild animals, and so it's logical that genes that control comb size and similar traits are affected when an animal returns to the wild. One interesting observation is that despite domesticated chickens having very large combs, which should make them sexually attractive, combs have become considerably smaller in the chickens that are now living wild on Kauai," says Dominic Wright.

During feralization, the chickens' egg production and brooding behaviour have altered. The researchers determined which regions of the genetic material in the Kauai chickens have been altered during the feralization. They then studied these regions in more detail in a hybrid chicken population that had been bred in captivity as a cross-breed between domesticated chickens and Red Junglefowl. In this way, the researchers could correlate the chickens' behaviour and appearance, such as comb size, to the levels of expression of specific genes.

The results suggest that the process of feralization affects other genes than those important during domestication, and it is not a case of simply reversing the changes that took place when the chickens were domesticated.

Read more at Science Daily

Sep 29, 2016

New evidence shifts the timeline back for human arrival in the Americas

The evidence for earlier human arrival in the Americas comes from a rich archaeological site in southeastern South America called Arroyo Seco 2.
Ancient artifacts found at an archeological site in Argentina suggest that humans occupied South America earlier than previously thought.

Approximately 13,000 years ago, a prehistoric group of hunter-gathers known as the Clovis people lived in Northern America. Previous research suggests that the Clovis culture was one of the earliest cultures in the Americas. However, more recent research from the Pampas region of Argentina supports the hypothesis that early Homo sapiens arrived in the Americas earlier than the Clovis hunters did.

The evidence for earlier human arrival in the Americas comes from a rich archaeological site in southeastern South America called Arroyo Seco 2. A group of scientists led by Gustavo Politis from CONICET and the Universidad Nacional del Centro de la Provincia de Buenos Aires present the research in a new PLOS ONE study.

At Arroyo Seco 2, the researchers excavated ancient tools, bone remains from a variety of extinct species, and broken animal bones containing fractures caused by human tools. They used radiocarbon dating to determine the age of the mammal bones and analyzed the specimens under a microscope.

The analysis revealed the presence of limb bones from extinct mammals at the site, which may indicate human activities of transporting and depositing animal carcasses for consumption at a temporary camp. The bones of some mammal species were concentrated in a specific part of the site, which could indicate designated areas for butchering activities. Microscopic examination also revealed that some bones contained fractures most likely caused by stone tools. The remains were dated between 14,064 and 13,068 years ago, and the authors hypothesize that Arroyo Seco 2 may have been occupied by humans during that time.

This timeline, along with evidence from other South American sites, indicates that humans may have arrived in southern South America prior to the Clovis people inhabiting the Americas, but after the onset of the Last Glacial Maximum, the last glacial period, which took place 19,000 to 20,000 years ago.

Read more at Science Daily

News from the primordial world

DNA strand illustration (stock image). On the surface, RNA and DNA molecules look similar, with DNA forming a ladder-like structure (with nucleobase pairs as the rungs and sugar molecule backbones as the sides) and RNA forming what looks like just one side of a ladder.
A new study led by scientists at The Scripps Research Institute (TSRI) offers a twist on a popular theory for how life on Earth began about four billion years ago.

The study questions the "RNA world" hypothesis, a theory for how RNA molecules evolved to create proteins and DNA. Instead, the new research offers evidence for a world where RNA and DNA evolved simultaneously.

"Even if you believe in a RNA-only world, you have to believe in something that existed with RNA to help it move forward," said Ramanarayanan Krishnamurthy, associate professor of chemistry at TSRI and senior author of the new study. "Why not think of RNA and DNA rising together, rather than trying to convert RNA to DNA by means of some fantastic chemistry at a prebiotic stage?"

The study was published recently in the journal Angewandte Chemie.

A Look Back in Time

Researchers have explored the RNA world hypothesis for more than 30 years. The idea behind this theory is that a series of chemical reactions led to the formation of self-replicating RNA molecules. RNA then evolved to create proteins and enzymes that resembled early versions of what makes up life today. Eventually, these enzymes helped RNA produce DNA, which led to complex organisms.

On the surface, RNA and DNA molecules look similar, with DNA forming a ladder-like structure (with nucleobase pairs as the rungs and sugar molecule backbones as the sides) and RNA forming what looks like just one side of a ladder.

If the RNA world theory is accurate, some researchers believe there would have been many cases where RNA nucleotides were mixed with DNA backbones, creating "heterogeneous" strands. If stable, these blended "chimeras" would have been an intermediate step in the transition to DNA.

Problems with Instability

However, the new study shows a significant loss of stability when RNA and DNA share the same backbone. The chimeras do not stay together as well as pure RNA or pure DNA, which would compromise their ability to hold genetic information and replicate.

"We were surprised to see a very deep drop in what we would call the 'thermal stability,'" said Krishnamurthy, who in addition to his position at TSRI has joint appointments with the National Science Foundation (NSF)-National Aeronautics and Space Administration (NASA) Center for Chemical Evolution and the Simons Collaboration on the Origins of Life. This instability appeared to be due to a difference in the DNA sugar molecule structure versus the RNA sugar molecule.

The finding supported previous research from Nobel laureate and Harvard University Chemistry and Chemical Biology Professor Jack Szostak that showed a loss of (nucleotide-binding aptamer) function when RNA mixed with DNA.

Because of this instability, chimeras in the RNA world would have likely died off in favor of more stable RNA molecules. This reflects what scientists see in cells today: If RNA nucleobases mistakenly join a DNA strand, sophisticated enzymes will rush to fix the mistake. Evolution has led to a system that favors more stable, "homogeneous" molecules.

These sophisticated enzymes were probably not around at the time of RNA and DNA's early evolution, so these substitutions may have had a crippling effect on the molecules' ability to replicate and function. "The transition from RNA to DNA would not have been easy without mechanisms to keep them separate," said Krishnamurthy.

Read more at Science Daily

Huge Claw, Bizarre Limbs Helped Ancient Reptile Dig

About 200 million years ago in what is today New Mexico, a Drepanosaurus used its massive claw and powerful arm to rip away tree bark and expose the insects within.
About 200 million years ago, a reptile resembling a chameleon wielded a digit on each of its front legs with a massive claw, and used that claw as a digging tool in a manner similar to that of modern anteaters.

However, the oversize claws weren't even the weirdest part of this animal's forelimbs, according to a new study describing fossils of the unusual appendages.

The front limbs of most tetrapods -- four-limbed animals with backbones -- share certain similarities in bone arrangement and shape. But this unusual reptile's forelimb structure diverged dramatically, suggesting that early tetrapod limbs may have been more diverse than previously suspected. [Image Gallery: 25 Amazing Ancient Beasts]

The first fossil of this ancient, chameleon-like reptile -- known as Drepanosaurus and measuring about 1.6 feet (0.5 meters) in length -- was found in Italy in the 1970s and was described in 1980, according to study author Adam Pritchard, a postdoctoral fellow with the Department of Geology at Yale University.

But the fossil, though mostly preserved, was badly crushed, Pritchard told Live Science.

Scientists managed to isolate individual bones just enough to suggest the creature had odd front limbs. But to reconstruct the limbs to see what they actually looked like would take more, uncrushed, fossil material.

That material didn't emerge until decades later.

In 2010, Pritchard began investigating fossils excavated by the study's other co-authors, in Ghost Ranch, New Mexico. He and his colleagues identified three Drepanosaurus specimens that were preserved in 3D, providing a first glimpse of the forelimbs that had intrigued scientists 30 years earlier.

Pritchard explained that tetrapod forelimbs follow a basic plan: a single bone, the humerus, attaches to the shoulder. Attached to the humerus are two elongated parallel bones, the radius and ulna, which meet a series of shorter wrist bones at the base of the hand.

Drepanosaurus, however, had two differently shaped bones extending from the humerus that were not parallel. One was shaped like a crescent moon, Pritchard said. Attached to this crescent-moon bone were two long and slender wrist bones that were much longer than the other wrist bones.

"The idea we confirmed with the new fossils was that the crescent moon bone was, in fact, the ulna," Pritchard said. "Drepanosaurus maintains the traditional bones that make up the forelimb, but they're radically altered."

The fossils were so well-preserved that the study authors were able to see where the forelimb bones would have met one another, so they could determine the animal's range of motion. The scientists determined that Drepanosaurus was capable of powerfully moving its forelimb forward and pulling it back, but probably couldn't raise or lower the limb much.

Since the forelimbs were tipped with giant claws, this suggested that Drepanosaurus used its arms for digging, in a method employed by modern anteaters called "hook and pull," the researchers said.

"It involves hooking the claw powerfully into substrate and pulling the entire forelimb back, using the entire musculature of the arm to rip open whatever it's attacking at the time," Pritchard explained.

Read more at Discovery News

3D-Printed 'HyperElastic Bone' Could Quickly Mend Breaks

A cheap and easy to make synthetic bone material has been shown to stimulate new bone growth when implanted in the spines of rats and a monkey's skull, researchers said.

Human trials using the biomaterial, called Hyper-Elastic Bone (HB), could begin in the next five years, according to the research team from Northwestern University.

"We knew this material had great mechanical properties and it was very easy and rapid to 3-D print," said study author Adam Jakus, a researcher at Northwestern University, during a conference call with reporters.

"Its biological effects in the outcomes we observed directly were quite astounding."

The material is "made mostly of a ceramic, which contains mineral found in teeth and bones, and polymer, both of which are used in the clinic," said the study in Science Translational Medicine.

Unlike bone grafts, which are more costly, more brittle and risk being rejected in the patient's body, the biomaterial could be printed into many shapes and cut, folded, and sutured to fit on demand, according to the report.

"When implanted into experimental animals, HB quickly integrated with the surrounding tissue, regenerating bone to promote spinal fusion in rats," said the study.

A larger piece was printed to fill a hole in a rhesus macaque's skull. It healed after four weeks, with no signs of infection or other side effects, and researchers were able to see evidence of new bone growth.

"This work represents what could be the next breakthrough in orthopedic, cranial facial and pediatric surgery when it comes to repairing and regenerating bone in bone to soft tissue defects," said study author Ramille Shah, assistant professor at Northwestern University.

Researchers hope the material will one day offer personalized implants for a range of bone injuries, including spine, dental, reconstructive, and bone cancer surgeries.

"There's a lot of pediatric patients who are born, especially in Third World countries, with orthopedic or maxillofacial defects," said Shah.

"And we hope that because the Hyper-Elastic Bone is scalable and at a lower cost, that it would be accessible to those types of patients."

From Discovery News

No, Friday's 'Black Moon' Isn't a Sign of the End Times

Just when you thought it was safe to go outside at night to do a little stargazing, the moon is being all weird again.

If you've been paying attention to the tabloid press, you'll likely know that Friday will play host to a "Black Moon." But you probably heard about it for all the wrong reasons. According to some outlets, this "rare" astronomical event is a signal that the world is going to come to an end and a prelude to the second coming of Jesus Christ. Why? Well, some people on social media said so.

Alas, like the last "Blood Moon", "Super Moon", "Blue Moon" , "Harvest Moon" and "Monster Moon" (OK, I made that last one up), Friday's "Black Moon" is a lot less interesting than it sounds.

Every so often, we'll experience one month that has two new moons. A new moon is the first phase of the lunar cycle, when the near-side of the moon is completely in shadow (and far side is bathed in sunlight). The new moon phase is the exact opposite of the full moon. A full moon is when the whole of the moon's face is illuminated (and the far side is in shadow). This is because, when looking up at the full moon, the sun is behind our planet, flooding the Earth-facing hemisphere in light.

In the case of the new moon, the moon is positioned between the Earth and sun, leaving the near side in darkness. We'll therefore see, well, not a lot. A couple of days after a new moon, as the lunar cycle rolls on, a thin crescent will appear (pictured top), but until then, the face of the moon will be, well, black.

More or less, the lunar cycle lasts a month (on average 29.53 days -- known as a synodic month), but September this year will see two new moons, one that occurred on Sept. 1 and the other that will occur on Sept. 30. This may sound familiar; the occasional second full moon in a month is known as a "Blue Moon" -- hence the saying "once in a blue moon" when describing a rare event.

It's worth noting, however, that there are other definitions of a "Black Moon" out there, so it certainly isn't an official astronomical designation. But it sounds dramatic and probably the reason why the tabloid press finds it so captivating.

Interestingly, the Sept. 30 Black Moon is exclusive to the Western Hemisphere only. The Eastern Hemisphere will experience the same new moon on Oct. 1, but as it's a new month for the Eastern Hemisphere, it's not their Black Moon. For their Black Moon, they have to wait until Oct. 30 for the second new moon of the month. It's all beginning to sound a bit unscientific, right?

Though Friday's Black Moon isn't really an astronomical phenomenon, its timing is nonetheless important to some religions and belief systems, such as Wicca. But does it foretell doom? No, unless you want to sell a lot of newspapers.

From Discovery News

Sep 28, 2016

New insight into eye diseases

This image shows how transferred genes activate the stem cell properties of normally dormant retinal cells.
Many diseases that lead to blindness, such as glaucoma and macular degeneration, are caused by the death of certain cells in the human retina that lack the ability to regenerate. But in species such as zebrafish these cells, known as Muller glial cells (MGs), do serve as retinal stem cells that are capable of generating new cells. In a new study, a research team led by Associate Professor of Ophthalmology Bo Chen investigated whether the regenerative power of cells in zebrafish could be recreated in mammals, specifically mice.

The research team transferred genes into MGs to activate the stem cell properties of these normally dormant cells, causing them to reproduce and make other types of retinal cells.

The strategy could be developed into a therapeutic tool, Chen said. "In the future we are hoping to manipulate these cells to replenish any lost retinal neurons, either in diseased or physically damaged retinas," he noted. "Potentially, it's a therapy to treat many different retinal degenerative diseases."

From Science Daily

Dementia: Catching the memory thief

It's over a hundred years since the first case of Alzheimer's disease was diagnosed. Since then we've learned a great deal about the protein 'tangles' and 'plaques' that cause the disease. How close are we to having effective treatments -- and could we even prevent dementia from occurring in the first place?

You may have heard of the 'dementia tsunami'. It's heading our way. As our population ages, the number of cases of dementia is set to rocket, overwhelming our health services and placing an enormous burden on our society.

Only, it's not quite so simple. A study published last year by Professor Carol Brayne from the Cambridge Institute of Public Health suggested that better education and living standards meant people were at a lower risk of developing the disease than previously thought and so, despite our ageing population, numbers were likely to stabilise -- and could even perhaps fall slightly.

Of course, even this more optimistic outlook does not hide the fact that millions of people worldwide will be diagnosed with dementia each year and millions are already living with the condition. An effective treatment for the 'memory thief' still seems like a distant prospect.

"Dementia isn't one disease: it's a constellation of changes in an individual's brain, with many underlying causes," says Brayne. "Most people, by the time they're in their eighties or nineties, have some of these changes in their brains, regardless of whether or not they ever develop dementia."

For this reason, Brayne believes we need a radical approach to tackling brain health throughout the course of our lifetime, with a greater emphasis on reduction in the risk of dementia achieved through measures in society that are related to better health in general, such as social and lifestyle changes, in addition to the focus on early therapeutic approaches to preventing or treating the disease through a pharmaceutical approach.

By far the most common and well-known form of dementia is Alzheimer's disease. Symptoms include memory problems, changes in behaviour and progressive loss of independence.

At a biological level, the disease sees a build-up of two particular types of proteins in the brain: fragments of beta-amyloid clump together in 'plaques' between nerve cells, and twisted strands of tau form 'tangles' within the nerve cells. These plaques and tangles lead to the death of nerve cells, causing the brain to shrink.

Clinical trials of Alzheimer's drugs are always going to be difficult, in part because trial participants are patients with advanced stage disease, who have already lost a significant number of nerve cells. But Professor Chris Dobson, who recently helped secure £17 million from the Higher Education Funding Council for England for a new Chemistry of Health Building, including the Centre for Misfolding Diseases, believes that most of the trials to date were destined to fail from the start because of a fundamental lack of understanding of the mechanisms that lead to Alzheimer's.

Understandably, most of the researchers tackling Alzheimer's approach the disease as a clinical -- or at least a biological -- problem. Dobson instead sees it as also being about chemistry and physics. He argues that the protein tangles and plaques -- collectively known as aggregates -- are demonstrating a physical property similar to the way in which crystals precipitate out of, say, salty water: all they need is a 'seed' to kick off the precipitation and the process runs away with itself. "In essence," he says, "biology is trying to suppress molecules behaving in a physical way." For his contributions, Dobson has been awarded the 2014 Heineken Prize for Biochemistry and Biophysics.

In 2009, Dobson, together with colleagues Professors Tuomas Knowles and Michele Vendruscolo, published a study that broke down the aggregation process into a combination of smaller steps, each of which could be tested experimentally. It became apparent to the team that drugs were failing in trials because they were targeting the wrong steps. "And this is still happening," says Vendruscolo. "Companies are still putting small molecules into clinical trials that, when we test them using our methods, we find stand no chance."

They believe there may be a role to play for 'neurostatins', which could do for Alzheimer's what statins already do to reduce cholesterol levels and prevent heart attacks and strokes. In fact, they may have already identified compounds that might fit the bill.

Professor Michel Goedert from the Medical Research Council Laboratory of Molecular Biology admits that there is a gap between our understanding of Alzheimer's and our ability to turn this into effective therapies.

"We know much about the causes of inherited forms of Alzheimer's disease, but this knowledge has so far not led to any therapies," he says. "It's clear now that abnormal protein aggregation is central to Alzheimer's disease, but we don't know the mechanisms by which this aggregation leads to neurodegeneration." Goedert himself played an instrumental part in studies that implicated the aggregation of tau protein in Alzheimer's disease and other neurodegenerative diseases, work that led to him being awarded the 2014 European Grand Prix from the Paris-based Foundation for Research on Alzheimer's Disease.

"I don't think we should talk of a cure," says Goedert. "At best, we will be able to halt the disease. Prevention will be much more important." Part of the problem, he says, lies in the fact that there is no absolute way of identifying those at risk of developing Alzheimer's disease.

The market for an Alzheimer's drug is massive, which is why pharmaceutical companies are racing to develop new drugs. Goedert doesn't believe we will ever find a single 'magic bullet', but will need to use combination therapies -- in the same way that we treat other diseases, such as HIV -- with each drug targeting a particular aspect of the disease.

Professor David Rubinsztein from the Cambridge Institute for Medical Research agrees with Goedert that we need to look at preventing Alzheimer's rather than just focusing on treating the disease. He, too, believes in the concept of neurostatins. "These compounds would be safe, well tolerated by most people and generally good for you; you could take them for many years before the onset of disease," he says. "Then we wouldn't need to worry about identifying people at highest risk of the disease -- everyone could take them."

Rubinsztein is the academic lead for Cambridge's new Alzheimer's Research UK Drug Discovery Institute, part of a £30 million Drug Discovery Alliance that also includes the University of Oxford and University College London. This state-of-the-art institute will fast-track the development of new treatments for Alzheimer's disease and other neurodegenerative diseases. In particular, the Alliance will look at promising drug targets, assess their validity and develop small molecules that target them. These could then be taken up by pharmaceutical companies for clinical trials, removing some of the risk that results in most 'promising' drug candidates failing early on.

Read more at Science Daily

Plastic Flowers Bloom Like the Real Thing

A new shapeshifting material can be preprogrammed to unfold at a specific second, minute or hour. The special polymer, developed by scientists at the University of North Carolina at Chapel Hill and the University of Akron, could be used in a range of areas from biomedicine -- such as administering a patient's drug therapy -- to engineering -- such as building a spacecraft.

Other morphing materials exist. But they mainly require some kind of external trigger -- light, heat, water, a difference in pH level -- to set the changes in motion.

For this new material the trigger is internal.

In their scientific report, Xiaobo Hu and his colleagues give the analogy of the internal workings of a mechanical watch. A spring provides the energy, while the gears to regulate the energy's release.

For the shapeshifting material, the internal mechanisms are not springs or gears but two different networks of chemical bonds inside a hydrogel polymer.

One network is dynamic, possessing the energy that ultimately transforms the shape of the object. The other network flows at a predictable state, which can be used to control how quickly the object transforms.

Changing the concentrations of these chemical bonds directly affects the speed of the shapeshifting.

To demonstrate the material's wow-factor, the scientists constructed a flower and programmed it to bloom. Watch the time-lapse below.

I have to say that although biomedical applications seem pretty important here, delivering a bouquet of roses to your sweetheart and having them bloom at a specific time sounds like a pretty great gift.

From Discovery News

5,000-Year-Old Swirling Rock Art Remains a Mystery

The Cochno Stone, which dates back to around 3000 B.C., contains a type of artwork called "cup and ring marks."
Archaeologists in Glasgow, Scotland, briefly excavated and then reburied a 5,000-year-old slab of stone that contains incised swirling geometric decorations.

The Cochno Stone, which measures 43 feet by 26 feet, contains swirling decorations, also called "cup and ring marks." The stone and its decorations have been known to people in the area since at least the 19th century. Decorations similar to these swirls have been found at other prehistoric sites around the world; however, the examples incised in the Cochno Stone are considered to comprise "one of the best examples" of such art in Europe, according to a statement by the University of Glasgow, which led the new study.

The stone slab was fully unearthed in West Dunbartonshire by Rev. James Harvey in 1887. By 1965, the stone had been vandalized with graffiti and damaged by the elements, so a team of archaeologists buried it beneath the dirt in order to protect the artwork . This summer's two-week re-excavation allowed archaeologists to use modern-day surveying and photography techniques to better record the artwork.

For instance, digital-scanning and mapping experts from the Factum Foundation used cutting-edge 3D-imaging technology to make a detailed digital record of the site, according to the university statement.

The re-excavation also revealed 19th- and 20th-century graffiti etched alongside the swirls, as well as painted lines intentionally made by an archaeologist named Ludovic Maclellan Mann, who worked at the site in 1937. Mann painted lines on the Cochno Stone to help measure the prehistoric artwork and see if there was a link to astronomical phenomena, such as eclipses.

Mann "was trying to prove that the symbols could predict eclipses and were marking movements of the sun and moon in prehistory," said Kenny Brophy, an archaeologist and senior lecturer at the University of Glasgow, in a video released by the university. He said that Mann's own data ended up disproving the archeologist's theory.

The meaning of the artwork is still unknown, said Brophy, adding that the vast amount of data gathered this summer may, in time, allow archaeologists to better understand the artifact. He said that the graffiti is also of interest and will help archaeologists better understand what people who lived in the local area thought of the artwork during the 19th and 20th centuries and how they incorporated it into their lives.

Read more at Discovery News

Ancient Roman Coins Found Beneath Japanese Castle

A 4th-century copper coin from ancient Rome was among the finds on Japan's Okinawa island.
Japanese archaeologists said on Wednesday they have for the first time unearthed ancient Roman coins at the ruins of an old castle.

The discovery of 10 bronze and copper coins -- the oldest dating from about 300-400 AD -- in southern Okinawa caught researchers by surprise.

It was the first time Roman Empire coins have been discovered in Japan, thousands of kilometers from where they were likely minted.

"At first I thought they were one cent coins dropped by US soldiers," archaeologist Hiroki Miyagi told AFP.

"But after washing them in water I realized they were much older. I was really shocked."

The sub-tropical island chain hosts a cluster of US military bases and thousands of troops.

A team of researchers have been excavating Katsuren castle, which is a UNESCO world heritage site, since 2013.

An X-ray analysis of the dime-sized coins showed some were embossed with Roman letters and possibly the image of Emperor Constantine I and a soldier holding a spear.

Several others dated from a later period -- the 17th century Ottoman empire.

Researchers were left scratching their heads about how the coins ended up at the castle in faraway Okinawa, which was built sometime in late 13th or early 14th century and abandoned about 200 years later.

It was once the residence of a feudal lord, whose wealth was linked to regional trade but he was not known to have had business ties with Europe.

"East Asian merchants in the 14 and 15th centuries mainly used Chinese currency, a round coin with a square hole in the middle, so it is unlikely that the Western coins were used as a means of currency," said Miyagi, who also teaches at Okinawa International University.

"I believe they probably got the coins in Southeast Asia or China."

From Discovery News

Sep 27, 2016

Biggest, Baddest Dinos Had Fanciest Head Bling

A recreation of Spinosaurus, one of the largest carnivorous dinosaurs. It was eye-catching from head to tail.
Carnivorous dinosaurs that rapidly evolved large bodies also tended to evolve bony skull ornaments, according to a new study.

An open habitat likely favored both big bodies and conspicuous head features on meat-eating dinosaurs, helping to explain why these two seemingly disconnected characteristics so often appeared in tandem. The findings are reported in a paper published this week in the journal Nature Communications.

"Head ornaments are very effective because they are on the major communication center of the dinosaurs," lead author Terry Gates of North Carolina State University's Department of Biological Sciences, told Discovery News.

Gates and colleagues Chris Organ and Lindsay Zanno investigated the relationship between body size and skull ornamentation across theropod dinosaurs, meaning dinos like T. rex that had short forelimbs, two larger hind limbs for walking or running and a hunger for meat.

The researchers show that evolution of large body size in dinosaurs was accelerated in lineages with bony skull structures known as ornaments.

"Ornaments we defined as any structure that was extraneous," Gates said, explaining that they "came in varieties of crests, knobs, rugosites (wrinkled thick skin), and horns."

Crests are thin sheets of bone that rise above the skull. In many dinosaurs, such as Dilophosaurus, they probably looked a bit like an elaborate hairdo from a distance.

As for hairdos on humans, the ornaments probably served as unique identifiers. During displays, these features might have communicated information about the individual's sex, age, health and other factors.

"Animals today use signals other than size to communicate with one another," Gates explained, offering the rhinoceros as a living example. "Rhinos are large, but use their horns for maintaining social structure."

He and his colleagues are not sure when ornaments first evolved on carnivorous dinosaurs, and what initial function they might have held. They suspect that the features started out small before becoming larger and more varied across different dinosaur species.

Oviraptors -- a type of theropod that had claws, a toothless muscular jaw, slender limbs and other bird-like characteristics -- might have initially used their head ornaments for heat control. Later they were probably co-opted for visual communication, which is critical for today's birds.

Read more at Discovery News

Mystery Over Face-Down Skeleton Partly Solved

Swiss researchers may have solved the mystery over the identity of a 17th-century man who was buried face-down with a knife and purse filled with coins.

X-ray computer tomography of the coins has revealed the man was likely a merchant, but the reason for his prone burial continues to puzzle the archaeologists.

Unearthed in 2013 in the Bernese Lakeland region of Switzerland during the construction on a new underground garage, the skeleton was found along 342 bodies laid to rest between the 8th and 17th centuries. The individual was among the last 15 bodies to be buried at the ancient cemetery.

The face-down skeleton stood out from all the other graves.

"It is certainly a deviant burial, in the sense that the burial practices here seem to be very unusual for the time," Christian Weiss, a numismatic expert with the Archaeological Services of Canton Bern, told Discovery News. "The individual was facing to the ground; moreover, a knife and a purse were found within the burial where we normally don't find any grave goods in this time," Weiss said.

Under the individual's chest, the archaeologists found what remained of a leather purse. Over time, the leather had decomposed and the coins it contained had corroded together to form a solid block of metal.

Unable to separate the coins, the researchers turned to a powerful X-ray computer tomograph, a new instrument called µDETECT. Used in conjunction with a high resolution detector, the µDETECT revealed the presence of 24 coins.

"The astonishing fact about these coins is that they belong to three different coin circulation areas, the Fribourg-Bern-Solothurn, Basel-Freiburg in Breisgau and Luzern-Schwyz regions," Weiss said.

The finding suggests the individual was moving in these three areas, which had their own coins in local circulation at that time.

"It is possible he was a traveling merchant," Weiss said.

With one exception, a heavily worn silver coin from France, all the coins in the purse are of rather low value.

"They are really just small change," Weiss said. "The most interesting to me isn't really one particular coin, but the ensemble all together. We rarely get such a big ensemble of small value coins from this time."

Read more at Discovery News

Neanderthals Made 'Jewelry' from Animal Teeth, Shells

Shown are the Châtelperronian body ornaments and bone points archaeologists discovered at the Grotte du Renne in Arcy-sur-Cure, France.
About 42,000 years ago, the Neanderthals -- the stocky cousins of modern humans -- fashioned tiny jewelry beads from animal teeth, shells and ivory, a new study finds.

The finding is momentous, as it suggests that Neanderthals could engage in symbolic expression -- the ability to make art -- before they went extinct about 30,000 years ago, the researchers said.

"We now know that some of the last Neanderthals in Europe made artifacts that we do not see in Neanderthal material culture before that time," said Frido Welker, the study's lead researcher and a doctoral student of human evolution at the Max Planck Institute for Evolutionary Anthropology in Germany.

The discovery is based on the artifacts and bony remains found in the Grotte du Renne cave in Arcy-sur-Cure, an area located about 125 miles (200 kilometers) southeast of Paris. After the cave was discovered in 1949, its contents were dated to about 40,000 to 50,000 years ago, a period during which modern humans were sweeping across Europe and displacing the Neanderthals, the researchers said.

At first, anthropologists credited the beads to the Neanderthals, but the prevailing view of Neanderthals was that they didn't have the brainpower to craft such items. That prompted many experts to wonder whether the excavation team had made a mistake in attributing the beads to Neanderthals, when perhaps modern humans had made the ornaments, according to Phys.org.

The researchers on the new study set out to answer that question once and for all.

"We wanted to know whether an archaeological culture called the Châtelperronian was made by Neanderthals or modern humans," Welker told Live Science in an email. "If they were modern humans, they would be some of the earliest modern humans on the European continent, and might have played a role in Neanderthal extinction."

The ancient bone fragments in the cave did not have enough preserved DNA for a thorough analysis, so the researchers turned to another identifying factor: proteins.

They used several mass-spectrometry techniques to study the proteins preserved in about 200 ancient bone specimens from the cave, Welker said. The mass-spectrometry methods were key to the experiment, he added. That's because proteins are made out of amino acids, which are joined together on a string.

Each amino acid has a different weight, or mass. "By using mass-spectrometry, we can establish the different sequences of amino acids in our sample and compare that with existing protein databases," Welker said.

They found that, although the majority of the bone fragments belonged to horses or aurochs (wild cattle), some were clearly hominin, a group consisting of modern and extinct human species, Welker said. Moreover, the researchers identified an amino-acid sequence that was unique to Neanderthals, proving that the bones did not belong to modern humans or the Denisovans, an extinct human relative, he said.

Results from additional testing methods, such as direct radiocarbon dating and ancient mitochondrial DNA analysis, also hinted that the bones belonged to Neanderthals, he said.

One of the proteins found in the Neanderthal bones was a type of collagen found only in growing bones. In addition, the specimen had a high proportion of a certain kind of nitrogen isotope (a variation of an element, but with a different number of neutrons) that is associated with breast-fed infants.

"We identified ancient proteins in these Neanderthal bone specimens that indicated they belong to a very young infant, probably around the age of 1 year old," Welker said.

The baby likely lived around the same time when the Neanderthals crafted the 1.2- to 2.4-inch-long (3 to 6 centimeters) beads, the researchers said. However, they added that they "don't know if they [the beads] belong to a single 'necklace' or were worn in different ways, and they were found in different areas of the Grotte du Renne," Welker said.

Read more at Discovery News

World's Largest Single-Dish 'Alien Hunter' Is Online

The world's largest radio telescope began operating in southwestern China Sunday, a project Beijing says will help humanity search for alien life.

The Five-hundred-meter Aperture Spherical Radio Telescope (FAST), nestled between hills in the mountainous region of Guizhou, began working around noon, the official Xinhua news agency reported.

Built at a cost of 1.2 billion yuan ($180 million), the telescope dwarfs the Arecibo Observatory in Puerto Rico as the world's largest single-dish radio telescope, with twice the sensitivity and a reflector as large as 30 football fields, it said.

FAST will use its vast dish, made up of 4,450 panels, to search for signs of intelligent life, and to observe distant pulsars -- tiny, rapidly spinning neutron stars that are left over after supernova explosions.

China sees its ambitious military-run, multi-billion-dollar space program as symbolizing the country's progress. It plans a permanent orbiting space station by 2020 and eventually a manned mission to the moon.

Chinese President Xi Jinping celebrated the launch, with reports Sunday that he had sent a congratulatory letter to the scientists and engineers who contributed to its creation.

The telescope represents a leap forward for China's astronomical capabilities and will be one of several "world-class" telescope projects launched in the next decade, said Yan Jun, head of China's National Astronomical Observation (NAO), according to Xinhua.

In a test run before the launch, FAST detected electromagnetic waves emitted by a pulsar more than 1,300 light-years away, state media reported an NAO researcher as saying.

Earlier Xinhua cited Wu Xiangping, director-general of the Chinese Astronomical Society, as saying that the telescope's high degree of sensitivity "will help us to search for intelligent life outside of the galaxy".

Experts have been hunting for alien intelligence for six decades, pointing radio telescopes at stars in the hope of discovering signals from other civilizations, but have not yet found any evidence.

'Wildest Imagination'

Last month a "strong signal" detected by a Russian telescope searching for extraterrestrial signals stirred interest among scientists, but experts said it was far too early to make conclusions about its origin. It is now thought to have been a stray signal from a defunct Soviet-era military satellite.

But the new FAST telescope could "lead to discoveries beyond our wildest imagination," Douglas Vakoch, president of METI, a group seeking to send messages to space in search of alien life, told Xinhua.

Construction of FAST began in 2011, and local officials relocated nearly 10,000 people living within five kilometers (three miles) to create a quieter environment for monitoring. Cell phones in the area must be powered off to maintain radio silence.

Read more at Discovery News

Sep 26, 2016

Greenland Is Melting Faster Than Expected

Using new measurements, scientists have discovered that Greenland's ice sheet is losing more mass than previously thought.
Bad news keeps flowing for the icy landscapes of the world.

Rising temperatures are melting ice and sending it to the ocean, a process that is pushing sea levels higher and altering the landscape at both poles. The latest news comes from Greenland, where researchers have used high-tech satellite and GPS measurements to see how much mass the ice sheet is losing.

Their results, published this week in Science Advances, indicate that it's melting faster than previous estimates, particularly in areas where the ice sheet comes in direct contact with the ocean. It's a troubling finding for the future of coastal areas around the world.

The Greenland ice sheet contains enough water that, if melted, would raise sea levels up to 23 feet. Rising temperatures have already eaten away at it, and Greenland's ice sheet is responsible for about 30 percent of the observed foot of sea level rise since the start of the 20th century. While the rest of the ice sheet isn't going to disappear overnight, it's fate is intimately tied to the fate of communities along the coast.

"Greenland is one of the more pronounced contributors to sea level rise," Michael Willis, a remote sensing expert at the Cooperative Institute for Research in Environmental Sciences and co-author of the study, said. "In order to know how Greenland's ice may change in the future, we need to focus on the areas where the changes have occurred over both short and long time periods."

Because of Greenland's remoteness and sheer mass, measuring changes is a challenge. The land under the ice sheet also adds another wrinkle. Ice started receding due to natural forces 20,000 years ago, and the land underneath has been slowly rising in response.

The Gravity Recovery and Climate Experiment (GRACE), the satellites tasked with measuring the mass changes in Greenland and other icy landscapes around the world, has a hard time time seeing the difference between rising land and ice.

"GRACE can only measure mass change," Willis said. "It cannot tell you what is changing mass."

To get that end of the equation, Willis and his colleagues turned to GPS sensors set up across Greenland. Comparing them to satellite data, they found that the Greenland ice sheet was losing mass 8 percent faster than previous estimates.

The areas losing mass the fastest are spots where the ice sheet has a direct connection to the ocean. Rising ocean waters and air temperatures are essentially putting ice in a vise grip of warming and speeding up melt. Geology is also compounding the rapid loss of ice in those regions.

"The ice sheet in these basins is also steeper than the average for the ice sheet, therefore the ice flows, on average, faster there, too," Willis said. "Simply put, the shape of the ice sheet and the contact with the ocean makes it likely that these areas respond more pronouncedly to changes in climate boundary conditions — be they atmospheric, oceanic or glaciological."

Read more at Discovery News

Shrinking Mercury Is Tectonically Active

If you view the solar system's innermost planet as a static and barren husk, you're only half correct. It turns out that Mercury may not be static at all and actually joins Earth in a very exclusive tectonic club.

In 2015, NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission ended in spectacular style, smashing into the planet's surface after being in orbit since 2011. The spacecraft revolutionized our understanding about Mercury, revealing new facts about the world's magnetic field, composition, the existence of ice in its shady caraters and that the world had physically shrunk since formation.

Now, planetary scientists have used observations from MESSENGER during its final months in a low-Mercury orbit to see small geological features called scarps that could have only been formed if Mercury's geology is currently active. In other words, Mercury continues to shrink today.

Small graben, or narrow linear troughs, have been found associated with small fault scarps (lower white arrows) on Mercury, and on Earth's moon.
"The young age of the small scarps means that Mercury joins Earth as a tectonically active planet, with new faults likely forming today as Mercury's interior continues to cool and the planet contracts," said senior scientist Tom Watters, of the Smithsonian National Air and Space Museum in Washington, D.C.

Scarps are a well known feature on Mercury's surface, some of which are known to create steep cliffs extending hundreds of miles long and, in some places, reach over a mile high. These geological features were first documented by the flybys of NASA's Mariner 10 spacecraft in the 1970's and later confirmed by MESSENGER. These observations helped planetary scientists reveal that, as the planet cooled over hundreds of millions of years, the entire mass contracted, creating these scarps as the surface buckled under the pressure.

But as MESSENGER made its final orbits around Mercury, it noticed far smaller scarp-like features. If these small scarps were ancient, they should have been eroded away long ago by the continuous erosion of meteoroids and comets, which led Watters and his team to realize these were young features. So, far from being a static world Mercury could be a hothouse of "Mercury-quakes" as the entire planet contracts, further crushing its crust today.

Read more at Discovery News

Restored: Alan Turing's 1951 Computerized Music

Alan Turing (right) at the console of the Mark II computer.
New Zealand researchers said Monday they have restored the first recording of computer-generated music, created in 1951 on a gigantic contraption built by British genius Alan Turing.

The aural artefact, which paved the way for everything from synthesizers to modern electronica, opens with a staunchly conservative tune -- the British national anthem "God Save the King."

Researchers at the University of Canterbury (UC) in Christchurch said it showed Turing -- best known as the father of computing who broke the WWII Enigma code -- was also a musical innovator.

"Alan Turing's pioneering work in the late 1940s on transforming the computer into a musical instrument has been largely overlooked," they said.

The recording was made 65 years ago by a BBC outside-broadcast unit at the Computing Machine Laboratory in Manchester, northern England.

The machine, which filled much of the lab's ground floor, was used to generate three melodies; "God Save the King," "Baa Baa Black Sheep" and Glenn Miller's swing classic "In the Mood."

But when UC professor Jack Copeland and composer Jason Long examined the 12-inch (30.5 centimeter) acetate disc containing the music, they found the audio was distorted.

"The frequencies in the recording were not accurate. The recording gave at best only a rough impression of how the computer sounded," they said.

They fixed it with electronic detective work, tweaking the speed of the audio, compensating for a "wobble" in the recording and filtering out extraneous noise.

"It was a beautiful moment when we first heard the true sound of Turing's computer," Copeland and Long said in a blog post on the British Library website.

The two-minute recording can be heard here.

Read more at Discovery News

Cats Traveled with Vikings and Farmers

The early origins of domesticated cats are shrouded in mystery, but a new genetic analysis suggests that felines traveled the world with farmers and Vikings.

The News section of Nature reports that the broadest genetic analysis to date of ancient cats reveals two waves of cat expansion. In the first wave, cats spread from the Middle East into the eastern Mediterranean, alongside human farmers. The second wave of expansion started in Egypt — where cats had religious significance and were often mummified — and spread by sea to Eurasia and Africa.

These discoveries come courtesy a study of the mitochondrial DNA of 209 ancient cats whose remains were preserved at archaeological sites. Mitochondrial DNA is passed down through the maternal line and is separate from the nuclear DNA that comes from both parents. The research was presented at the 7th International Symposium on Biomolecular Archaeology, which took place between Sept. 14 and Sept. 16 at the Oxford University Museum of Natural History.

A lack of funding has caused research on cat domestication to lag behind research on dog domestication, study researcher Eva-Maria Geigl, an evolutionary geneticist at the Institut Jacques Monod in France, told Nature. Archaeological evidence suggests that cats and humans started to interact around the dawn of agriculture. In 2004, researchers reported in the journal Science that they'd discovered a human and a cat buried together on the island of Cyprus. The burial dated back 9,500 years. Prior to that discovery, researchers had thought that cats had been domesticated in Egypt about 4,000 years ago — though the discovery of two cats and four kittens in an animal burial ground in the Upper Egypt city of Hierakonpolis in 2014 suggests the existence of some sort of cat husbandry in Egypt 2,000 years before that.

Villagers in China may have domesticated cats about 5,300 years ago, researchers reported in 2013 in the journal Proceedings of the National Academy of Sciences. Based on a few bones, the scientists found that the cats ate a diet that was heavy in millet — or, more likely, that they ate a diet heavy in rodents that ate a lot of millet. This dietary information meshes with the theory that cats were drawn to early agricultural settlements by a plethora of prey. Humans would have encouraged the feline infiltration because cats got rid of rodent pests.

Read more at Discovery News

Sep 25, 2016

ALMA Explores the Hubble Ultra Deep Field: Deepest ever millimeter observations of early Universe

A trove of galaxies, rich in carbon monoxide (indicating star-forming potential) were imaged by ALMA (orange) in the Hubble Ultra Deep Field. The blue features are galaxies imaged by Hubble. This image is based on the very deep ALMA survey by Manuel Aravena, Fabian Walter and colleagues, covering about one sixth of the full HUDF area.
International teams of astronomers have used the Atacama Large Millimeter/submillimeter Array (ALMA) to explore the distant corner of the Universe first revealed in the iconic images of the Hubble Ultra Deep Field (HUDF). These new ALMA observations are significantly deeper and sharper than previous surveys at millimetre wavelengths. They clearly show how the rate of star formation in young galaxies is closely related to their total mass in stars. They also trace the previously unknown abundance of star-forming gas at different points in time, providing new insights into the "Golden Age" of galaxy formation approximately 10 billion years ago.

The new ALMA results will be published in a series of papers appearing in the Astrophysical Journal and Monthly Notices of the Royal Astronomical Society. These results are also among those being presented this week at the Half a Decade of ALMA conference in Palm Springs, California, USA.

In 2004 the Hubble Ultra Deep Field images, pioneering deep-field observations with the NASA/ESA Hubble Space Telescope, were published. These spectacular pictures probed more deeply than ever before and revealed a menagerie of galaxies stretching back to less than a billion years after the Big Bang. The area was observed several times by Hubble and many other telescopes, resulting in the deepest view of the Universe to date.

Astronomers using ALMA have now surveyed this seemingly unremarkable, but heavily studied, window into the distant Universe for the first time both deeply and sharply in the millimetre range of wavelengths. This allows them to see the faint glow from gas clouds and also the emission from warm dust in galaxies in the early Universe.

ALMA has observed the HUDF for a total of around 50 hours up to now. This is the largest amount of ALMA observing time spent on one area of the sky so far.

One team led by Jim Dunlop (University of Edinburgh, United Kingdom) used ALMA to obtain the first deep, homogeneous ALMA image of a region as large as the HUDF. This data allowed them to clearly match up the galaxies that they detected with objects already seen with Hubble and other facilities.

This study showed clearly for the first time that the stellar mass of a galaxy is the best predictor of star formation rate in the high redshift Universe. They detected essentially all of the high-mass galaxies and virtually nothing else.

Jim Dunlop, lead author on the deep imaging paper sums up its importance: "This is a breakthrough result. For the first time we are properly connecting the visible and ultraviolet light view of the distant Universe from Hubble and far-infrared/millimetre views of the Universe from ALMA."

The second team, led by Manuel Aravena of the Núcleo de Astronomía, Universidad Diego Portales, Santiago, Chile, and Fabian Walter of the Max Planck Institute for Astronomy in Heidelberg, Germany, conducted a deeper search across about one sixth of the total HUDF.

"We conducted the first fully blind, three-dimensional search for cool gas in the early Universe," said Chris Carilli, an astronomer with the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, USA and member of the research team. "Through this, we discovered a population of galaxies that is not clearly evident in any other deep surveys of the sky."

Some of the new ALMA observations were specifically tailored to detect galaxies that are rich in carbon monoxide, indicating regions primed for star formation. Even though these molecular gas reservoirs give rise to the star formation activity in galaxies, they are often very hard to see with Hubble. ALMA can therefore reveal the "missing half" of the galaxy formation and evolution process.

"The new ALMA results imply a rapidly rising gas content in galaxies as we look back further in time," adds lead author of two of the papers, Manuel Aravena (Núcleo de Astronomía, Universidad Diego Portales, Santiago, Chile). "This increasing gas content is likely the root cause for the remarkable increase in star formation rates during the peak epoch of galaxy formation, some 10 billion years ago."

The results presented today are just the start of a series of future observations to probe the distant Universe with ALMA. For example, a planned 150-hour observing campaign of the HUDF will further illuminate the star-forming potential history of the Universe.

"By supplementing our understanding of this missing star-forming material, the forthcoming ALMA Large Program will complete our view of the galaxies in the iconic Hubble Ultra Deep Field," concludes Fabian Walter.
Astronomers specifically selected the area of study in the HUDF, a region of space in the faint southern constellation of Fornax (The Furnace), so ground-based telescopes in the southern hemisphere, like ALMA, could probe the region, expanding our knowledge about the very distant Universe. Probing the deep, but optically invisible, Universe was one of the primary science goals for ALMA.

In this context "high mass" means galaxies with stellarmasses greater than 20 billion times that of the Sun ( 2 × 10^10 solar masses). For comparison, the Milky Way is a large galaxy and has a mass of around 100 billion solar masses.

This region of sky is about seven hundred times smaller than the area of the disc of the full Moon as seen from Earth. One of the most startling aspects of the HUDF was the vast number of galaxies found in such a tiny fraction of the sky.

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Ice Man, Ötzi: A treacherous murder with links to Central Italy

Ötzi's axe.
The copper used to make Ötzi's axe blade did not come from the Alpine region as had previously been supposed, but from ore mined in southern Tuscany. Ötzi was probably not involved in working the metal himself, as the high levels of arsenic and copper found in his hair had, until now, led us to assume. His murder over 5,000 years ago seems to have been brought about due to a personal conflict a few days before his demise, and the man from the ice, despite his normal weight and active life-style, suffered from extensive vascular calcification. Scientists from all over the world presented these and other new insights, at the recent International Mummy Congress in Bozen-Bolzano. To celebrate the 25th anniversary of Ötzi's discovery, the three days of the Congress, from 19th to 21st September, are all dedicated to the man from the ice.

Since the man from the ice came on the scene on 19th September 1991, he has not ceased to fascinate scientists from all over the world. No corpse has been more thoroughly investigated. "In terms of his significance for science, Ötzi is not simply an isolated mummy discovery. He could be seen as a typical European from earlier times and is precious for this reason alone," explained the anthropologist Albert Zink from EURAC Research, the scientific leader of the congress. "Ötzi is so well preserved as a glacier mummy and through this alone, he serves us researchers as a model for developing scientific methods which can then be used on other mummies," said Zink. "What concerns us most these days is to know who the man from the ice was, what role he played in society and what happened to him in the last days of his life. Sophisticated procedures, now available to scientists, are continually supplying us with new evidence," said Angelika Fleckinger, Director of the South Tyrol Museum of Archaeology which helped to organise the Congress.

Links to Central Italy

One surprising new fact has been unearthed which concerns the most extraordinary item amongst Ötzi's equipment -- the valuable copper axe. In contrast to what had previously been presumed, the copper used in the blade does not derive from the Alpine region (researchers had suggested East or North Tyrol as the most likely provenance) but from Central Italy. Professor Gilberto Artioli's archaeometallurgy research group at the University of Padua has discovered that the metal had been obtained from ore mined in South Tuscany. In order to determine its origin, Italian scientists took a tiny sample from the blade and compared the proportion of lead isotope -- a kind of "finger print" of the ore deposits which remains unchanged in any objects subsequently made from the ore -- with the corresponding data from numerous mineral deposits in Europe and the entire Mediterranean region.

The result pointed unequivocally to South Tuscany. "No one was prepared for this finding. We will commission further analyses in order to double-check these first results" stressed Angelika Fleckinger. If the original results are confirmed, this new evidence will give researchers some interesting food for thought. Was Ötzi as a trader travelling possibly as far as the area around today's Florence? What was the nature of the trading and cultural links with the south in those days? Did the exchange of goods also involve movements of the population? That is to say, did people from the south venture into the Alpine region and vice versa? "This is a particularly exciting insight especially with respect to questions about population development," explained Albert Zink.

Was he or was he not involved in smelting copper?

Another question long debated amongst the scientific community, is whether Ötzi was perhaps involved himself in the process of copper smelting. Scientists have advocated this thesis because raised arsenic and copper levels have been measured in the mummy's hair, a fact which might possibly be explained, for example, by breathing in the smoke which is released when melting and pouring metal. Geochemist Wolfgang Müller of Royal Holloway, University of London, who had already used isotope analysis to establish Ötzi's South Tyrol origins, has now turned to this question once more.

Using highly developed methods of analysis such as laser mass spectrometry and speciation analysis, Müller's team examined not just hairs but also samples from Ötzi's nails, skin and organs for possible heavy metal contamination. His, so far still provisional, findings suggest that the hypothesis that Ötzi was involved in processing metal was premature. Müller did indeed find slightly raised arsenic values in the nail sample, but not in other tissue samples. Raised copper levels were only present at the extremities and this correlates with other change indicators, and thus it is doubtful if one can establish a heavy metal contamination for Ötzi's actual life time: raised values might also be due to environmental influences over the 5,000 years since his death.

Radiological investigations with the latest CT equipment

A new computer tomography (CT) scan of the man from the ice was undertaken by radiologists Paul Gostner and Patrizia Pernter in January 2013 in the Department of Radiology of Bozen-Bolzano Hospital. To do this they used a CT-scanner of the latest generation which, thanks to its large opening, allowed the doctors to run Ötzi rapidly through the machine from head to toe despite the way his arm is angled. In addition to the vascular calcification in the arteries of his stomach and legs which had already been known about, the superior image allowed doctors to spot three small areas of calcification near to the outflow tracts of the heart which had hitherto escaped their notice. This substantiates the earlier finding made by molecular biologists in EURAC that Ötzi had a strong genetic predisposition to cardiovascular diseases and that this was probably also the main reason for his general arteriosclerosis.

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