Hoofed Foot Prosthetic Leg Found in Chinese Tomb

The 2,200-year-old remains of a man with a deformed knee attached to a prosthetic leg tipped with a horse hoof have been discovered in a tomb in an ancient cemetery near Turpan, China.

The tomb holds the man and a younger woman, who may or may not have known the male occupant, scientists say.

“The excavators soon came to find that the left leg of the male occupant is deformed, with the patella, femur and tibia together and fixed at 80 ,” archaeologists wrote in a paper published recently in the journal Chinese Archaeology.

The fused knee would have made it hard for the man to walk or ride horses without the prosthetic leg, the researchers found. The man couldn’t straighten his left leg out so the prosthetic leg, when attached, allowed the left leg to touch the floor when walking. The horse hoof at the bottom of the prosthetic leg acted like a foot.

The prosthetic leg was “made of poplar wood; it has seven holes along the two sides with leather tapes for attaching it to the deformed leg,” the archaeologists wrote. “The lower part of the prosthetic leg is rendered into a cylindrical shape, wrapped with a scrapped ox horn and tipped with a horsehoof, which is meant to augment its adhesion and abrasion.”

“The severe wear of the top implies that it has been in use for a long time,” they added.

Radiocarbon dating indicates that the tomb in Turpan (also spelled Turfan) dates back around 2,200 years. The only other known prosthetic leg in the world that dates to that time is part of a bronze leg found in Capua, Italy. That leg was destroyed in a bombing raid during World War II. Prosthetic toes, dating to earlier times, have been found in Egypt.

Who used it?

Two other studies, published in the journals Bridging Eurasia and Quaternary International, provide more details about the man who used the hoofed leg. Researchers estimate that the man was about 5 feet 7 inches (1.7 meters) tall, and between 50 and 65 years old when he died.

What caused the odd fusion of his left knee joint? “Different causes, like inflammation in or around the joint, rheumatism or trauma, might have resulted in this pathological change,” archaeologists wrote in the journal Bridging Eurasia.

Researchers found evidence that the man was infected with tuberculosis at some point in his life. They think that inflammation from the infection may have resulted in a bony growth that allowed his knee to fuse together. “The smooth surface of the bones affected by the ankyloses [joint fusion] suggests the active inflammatory process stopped years before death,” the researchers wrote in Bridging Eurasia.

The man appears to have been a person of modest means, as he was buried with nonluxurious items: ceramic cups and a jar, a wooden plate and wooden bows, the archaeologists found. Sometime after he died, his tomb was reopened, and the body of a 20-year-old woman was put in, disturbing the man’s bones. What relationship the man and woman had (if any) is unknown. The tomb was one of 30 that archaeologists excavated in the cemetery.

Gushi people

Based on the results of the radiocarbon dating, “the occupants of the cemetery might have belonged to the Gushi [also spelled Jushi] population,” archaeologists wrote in the Chinese Archaeology article.

Little is known about these people. Ancient Chinese texts suggest that the Gushi had a small state. “As recorded in the Xiyu zhuan (the Account of the Western Regions) of the Hanshu (Book of Han, by Ban Gu), during the middle of the Western Han, there lived in the Turfan Basin the Gushi population, who constitutes one of the ‘Thirty-six States of the Western Regions’ of the Qin and Han Dynasties,” the archaeologists wrote.

The Gushi state was conquered by China’s Han Dynasty during a military campaign in the first century B.C., according to ancient records. “Given that the study of the Gushi culture is yet at its nascent stage, the provides valuable new materials,” the archaeologists wrote.

Read more at Discovery News

'Superdeep' Diamonds Formed From Seawater

You might already know that the oceans absorb carbon dioxide from the atmosphere. But you might be surprised to discover that some of that carbon makes it to the sea floor and gets pushed into the Earth by the movement of the Earth’s tectonic plates, where it comes in contact with the mantle and forms a rare type of diamond.

In a newly published article in the scientific journal Nature, researchers from Great Britain’s Bristol University shed new light on the process by which the Earth’s recycling of carbon through plate subduction, in which the edge of one plate slides under the edge of another plate, and how that process forms so-called superdeep diamonds.

The researchers, who experimented with small samples of synthetic ocean floor rock at high pressures and temperatures, found that those slabs released most of their carbon at conditions equivalent to depths of 186 to 435 miles below the Earth’s surface.

In addition, the researchers tested the reaction of the melted slabs with the mantle. They were able to reproduce the mineral makeup observed in superdeep diamonds, which generally form at depths of below 155 miles.

The research not only provides an explanation for how superdeep diamonds are formed, but shows that they essentially are a snapshot of the deepest portions of the Earth’s carbon cycle. That makes them a useful tool for understanding what goes on inside our planet.

“One of the most amazing ideas that comes from this work is that superdeep diamonds are like marathon runners that have just crossed the finish line,” Bristol scientist Andrew R. Thomson explained in a press release.

"The difference in this case is the diamonds have just completed one of the most mind baffling journeys possible, from the ocean floor to around 700 km (435 miles) depth and back to the surface," he said. "Fortunately for scientists, their mineral inclusions are like stopwatches recording the entire journey, and with further work we will hopefully reveal many more remarkable secrets about their epic journey.”

As Thomson’s colleague Simon Kohn added: “Superdeep diamonds hold great potential for future research on the Earth’s volatile cycles, and we now know much more about the fundamental process that forms them. We will be able to use the wealth of information that is trapped inside the diamonds to build a detailed picture of processes occurring hundreds of kilometers beneath our feet.”

Read more at Discovery News

Gravitational Wave Rumors Rumble Social Media

In the roller-coaster rumor mill that surrounds some of the biggest physics endeavors of our time, it pays to remain skeptical when extraordinary claims of historic discoveries are made on social media.

In a tweet by Lawrence Krauss this morning, the well-known Arizona State University theoretical physicist and cosmologist wrote: “My earlier rumor about LIGO has been confirmed by independent sources. Stay tuned! Gravitational waves may have been discovered!! Exciting.”

In September, Krauss hinted that LIGO — the Laser Interferometer Gravitational Wave Observatory — had detected signs of elusive gravitational waves. “Rumor of a gravitational wave detection at LIGO detector. Amazing if true. Will post details if it survives,” he tweeted on Sept. 28, 2015.

The detector, which is split between two locations in Louisiana and Washington, has recently undergone a sensitivity upgrade, so hopes are high that the hard-to-find space-time wiggles may finally be directly detected, perhaps heralding a new era of gravitational wave astronomy.

It is thought that any acceleration of massive objects in the universe will generate gravitational waves. Black hole and neutron star collisions, supernovae and galactic mergers are all thought to be huge sources of gravitational waves; if we can somehow detect and, indeed, map them we could reveal some of the most massive objects and most energetic events in the cosmos.

The theoretical basis for gravitational waves spawn from general relativity equations that were formulated by Albert Einstein over 100 years ago. Although there is indirect evidence of gravitational waves carrying away energy from orbiting bodies (through extended observations of binary pulsar and white dwarf systems), the detection of the extremely slight impact of the propagation of gravitational waves that are hypothetically washing though our planet has been maddeningly difficult to achieve.

The LIGO stations use extremely fine-tuned laser interferometers to detect the passage of gravitational waves (that can be imagined as ripples in spacetime, much like the ripples that propagate across the surface of a pond) and only weeks before Krauss’ original tweeted rumor had embarked on a new phase of sophistication, called Advanced LIGO.

Now, Krauss may well be directly involved with the analysis of LIGO data and he could be privy to an exciting finding that may indicate a LIGO detection of gravitational waves, but until rigorous 3rd party studies are completed and studies are published in peer reviewed journals, it is hard to make solid conclusions about what has (or indeed hasn’t) been discovered by LIGO.

As pointed out by Jennifer Ouellette at Gizmodo, until we get any official word from LIGO, we just have to be patient and avoid jumping the gun when hearing rumors circulating on social media.

Gravitational waves haven’t been far from the headlines in recent years. In 2014, announcements were made that the South Pole-based telescope BICEP2 had detected signals in the cosmic microwave background (CMB) of primordial gravitational waves, thereby confirming some Big Bang and inflationary models. However, the announcement was made prematurely and it quickly became clear that the BICEP2 signal was a dud. Observations by the European Planck space telescope revealed that, in fact, the signal was caused by obscuring dust in our galaxy, not by gravitational waves etched into radiation generated at the furthest-most reaches of the universe. Bummer.

Even scientists can let excitement get the better of them, and while rumors are a part of human nature, social media rapidly boosts the virility of these rumors that can quickly be misconstrued as fact.

Read more at Discovery News

Unique 2-level cathode structure improves battery performance

Building a better battery is a delicate balancing act. Increasing the amounts of chemicals whose reactions power the battery can lead to instability. Similarly, smaller particles can improve reactivity but expose more material to degradation. Now a team of scientists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory, Lawrence Berkeley National Laboratory, and SLAC National Accelerator Laboratory say they've found a way to strike a balance--by making a battery cathode with a hierarchical structure where the reactive material is abundant yet protected.

Test batteries incorporating this cathode material exhibited improved high-voltage cycling behavior--the kind you'd want for fast-charging electric vehicles and other applications that require high-capacity storage. The scientists describe the micro-to-nanoscale details of the cathode material in a paper published in the journal Nature Energy January 11, 2016.

"Our colleagues at Berkeley Lab were able to make a particle structure that has two levels of complexity where the material is assembled in a way that it protects itself from degradation," explained Brookhaven Lab physicist and Stony Brook University adjunct assistant professor Huolin Xin, who helped characterize the nanoscale details of the cathode material at Brookhaven Lab's Center for Functional Nanomaterials.

X-ray imaging performed by scientists at the Stanford Synchrotron Radiation Lightsource (SSRL) at SLAC along with Xin's electron microscopy at CFN revealed spherical particles of the cathode material measuring millionths of meter, or microns, in diameter made up of lots of smaller, faceted nanoscale particles stacked together like bricks in a wall. The characterization techniques revealed important structural and chemical details that explain why these particles perform so well.

The lithium ion shuttle

Chemistry is at the heart of all lithium-ion rechargeable batteries, which power portable electronics and electric cars by shuttling lithium ions between positive and negative electrodes bathed in an electrolyte solution. As lithium moves into the cathode, chemical reactions generate electrons that can be routed to an external circuit for use. Recharging requires an external current to run the reactions in reverse, pulling the lithium ions out of the cathode and sending them to the anode.

Reactive metals like nickel have the potential to make great cathode materials--except that they are unstable and tend to undergo destructive side reactions with the electrolyte. So the Brookhaven, Berkeley, and SLAC battery team experimented with ways to incorporate nickel but protect it from these destructive side reactions.

They sprayed a solution of lithium, nickel, manganese, and cobalt mixed at a certain ratio through an atomizer nozzle to form tiny droplets, which then decomposed to form a powder. Repeatedly heating and cooling the powder triggered the formation of tiny nanosized particles and the self-assembly of these particles into the larger spherical, sometimes hollow, structures.

Using x-rays at SLAC's SSRL, the scientists made chemical "fingerprints" of the micron-scale structures. The synchrotron technique, called x-ray spectroscopy, revealed that the outer surface of the spheres was relatively low in nickel and high in unreactive manganese, while the interior was rich in nickel.

"The manganese layer forms an effective barrier, like paint on a wall, protecting the inner structure of the nickel-rich 'bricks' from the electrolyte," Xin said.

But how were the lithium ions still able to enter the material to react with the nickel? To find out, Xin's group at the CFN ground up the larger particles to form a powder composed of much smaller clumps of the nanoscale primary particles with some of the interfaces between them still intact.

"These samples show a small subset of the bricks that form the wall. We wanted to see how the bricks are put together. What kind of cement or mortar binds them? Are they layered together regularly or are they randomly oriented with spaces in between?" Xin said.

Nanoscale details explain improved performance

Using an aberration-corrected scanning transmission electron microscope--a scanning transmission electron microscope outfitted with a pair of "glasses" to improve its vision--the scientists saw that the particles had facets, flat faces or sides like the cut edges of a crystal, which allowed them to pack tightly together to form coherent interfaces with no mortar or cement between the bricks. But there was a slight misfit between the two surfaces, with the atoms on one side of the interface being ever so slightly offset relative to the atoms on the adjoining particle.

"The packing of atoms at the interfaces between the tiny particles is slightly less dense than the perfect lattice within each individual particle, so these interfaces basically make a highway for lithium ions to go in and out," Xin said.

Like tiny smart cars, the lithium ions can move along these highways to reach the interior structure of the wall and react with the nickel, but much larger semi-truck-size electrolyte molecules can't get in to degrade the reactive material.

Read more at Science Daily

First Flower Seeds from Dino Era Discovered

The world may never know if dinosaurs stopped to smell the flowers, but scientists have uncovered a few more clues about the ancient blossoms that grew alongside ankylosaurs and iguanadons. Recently, researchers discovered tiny Cretaceous flower seeds dating back 110 million to 125 million years, the oldest-known seeds of flowering plants. These puny pips offer a glimpse into the biology powering the ancient predecessors of all modern flowers.

The seeds are miniscule — the largest was no more than 0.1 inch (2.5 millimeters) in diameter — and unusually well-preserved, in such good condition that their internal cell structures were still visible. For the first time, scientists were able to detect seed embryos, the part of the seed where a new plant grows and emerges, and food storage tissues surrounding them. These structures offered a rare glimpse into how the Cretaceous seeds grew, and how they compare with plants alive today.

Else Marie Friis, lead author of the study and professor emerita at the Swedish Museum of Natural History, has analyzed some of these fossil remains of angiosperms — flowering plants — preserved in soils in Portugal and North America. She and her colleagues used a relatively new visualization technique — synchrotron radiation X-ray tomographic microscopy (SRXTM), which allowed them to explore the delicate fossils without damaging or destroying them. They imaged 250 seeds spanning 75 different species (some were also different genera), revealing the embryos and nutrient structures inside the seeds in exquisite detail.

Around half of the fossil seeds they examined contained preserved cell structures within their seed coats, and about 50 seeds held partial or complete embryos. Once they had 2D images of the embryos, they used software to model the embryos’ shapes in 3D, finding that their size and shape varied between seeds. In some cases, the embryos resembled those in modern plants believed to be distant relatives of the Cretaceous angiosperms.

“These observations give us new insights into the early part of the life cycle of early angiosperms, which is important for understanding the ecology of flowering plants during the emergence and dramatic radiation through the early Cretaceous,” Friis said in a video statement.

During the Cretaceous period, angiosperms evolved and diversified rapidly. Many new insect species, which also appeared during the Cretaceous, may have played a part in how quickly flowering plants took hold and thrived in the ancient landscape.

Read more at Discovery News

British Music Legend David Bowie Dies

British music legend David Bowie has died after a long battle with cancer, his official Twitter and Facebook accounts said Monday, prompting an outpouring of tributes.

Bowie died on Sunday surrounded by family, according to his social media accounts.

The iconic musician had turned 69 only on Friday, which coincided with the release of "Blackstar", his 25th studio album.

"David Bowie died peacefully today (Sunday) surrounded by his family after a courageous 18 month battle with cancer," said a brief statement posted to both his Twitter and Facebook accounts.

"While many of you will share in this loss, we ask that you respect the family’s privacy during their time of grief," it added.

Film director Duncan Jones, Bowie's son with his first wife Angela Bowie, confirmed the news on Twitter.

"Very sorry and sad to say it's true. I'll be offline for a while. Love to all," Jones wrote on his official account.

The death brings the curtain down on one of the most acclaimed artists of modern British music, with a career dating back to the hit "Space Oddity" in 1969, about an astronaut called Major Tom, who is abandoned in space.

It spanned styles ranging from glam rock, New Romantic, Krautrock and dance music to alternative rock, jungle, soul and hard rock, underpinned by an astonishing array of stage personas from the sexually ambiguous Ziggy Stardust to the so-called Thin White Duke.

He was born David Robert Jones in Brixton, inner south London on January 8, 1947, before his family moved out to the leafy suburb of Bromley when he was six.

Master of Reinvention

In the first of many re-inventions, he named himself David Bowie in 1966 to avoid confusion with Davy Jones, lead singer with Beatles rivals The Monkees, and studied Buddhism and mime.

The 1970s -- the decade that saw him dominate the British music scene and conquer the United States -- brought forward a string of successful albums.

It began with the critically acclaimed "Hunky Dory", continued with "The Rise and Fall of Ziggy Stardust and the Spiders from Mars" -- whose hits included "Starman" and "Suffragette City" -- followed by the rock album "Aladdin Sane", the apocalyptic "Diamond Dogs" and a fling with so-called plastic soul, "Station to Station."

He then switched gears once more, moving to Berlin to work with the electronic experimentalist Brian Eno product a trio of albums -- "Low", "Heroes" and "Lodger".

Read more at Discovery News

Milky Way Grew From the Inside Out

Scientists have made a cosmic growth chart of the Milky Way galaxy, an innovative blending of data collected by the ongoing Sloan Digital Sky Survey and a new technique to determine the ages of stars.

As expected, the analysis shows the galaxy’s central disk formed from the inside out, with red giant stars as old as about 13 billion years clustered toward the center and younger stars about 1 billion years old closer to the disk’s edge, astronomer Melissa Ness, with the Max Planck Institute for Astronomy in Heidelberg, Germany, told reporters at the American Astronomical Society meeting in Kissimmee, Florida.

“What we’re able to do … is understand how our galaxy has formed in detail, looking at the dispersion of ages, the gradient of the ages, how the ages change as a function of both the height from the (disk’s) plane and the radius," Ness said. "It’s understanding the details of this inside-out formation that is now possible."

Unique to the survey is its age-dating technique, which is based on a star’s size. Ness and colleagues used high-quality Sloan survey spectra, which reveals a star’s chemistry, with optical data collected by NASA’s Kepler space telescope to develop a model that can be used to pinpoint a star’s age.

“This is somewhat revolutionary because ages have previously been considered very hard to get, particularly from stellar spectra. They’re important, but they’re difficult,” Ness said.

The key was a newly discovered relationship between a star’s age and its ratio of carbon-to-nitrogen, concentrations of which can be ferreted out by analyzing a star’s spectra.

Read more at Discovery News

Deformed Mountain Lion Had Fangs in Forehead

It sounds like a hoax: A mountain lion with a second set of teeth growing out of its forehead.

But the Idaho Department of Fish and Game has confirmed that the young male mountain lion legally shot south of Preston had a growth on its head with a full set of fangs.

The growth, which hints at the snout of another cougar, had small whiskers as well.

It came to the department’s attention after it was shot at by a landowner, who saw it attacking a neighbor’s dog. Although the mountain lion ran off, the hunter followed it into the hills with his hounds and eventually killed it.

The hunter had a valid license and tag and had reported it to the conservation office as required by law.

According to biologists at the Idaho Fish and Game, the growth could be the result of a conjoined twin that died in the womb. Sometimes the surviving fetus will absorb the tissue of the twin into its own.

Another explanation is that it could be a teratoma tumor, a growth composed of tissue that makes up teeth, hair, and even fingers and toes. These tumors are rare, but have been seen before in humans and animals.

Whatever the case, the site of the animal is both frightening and sad. Although it had survived into young adulthood, it’s unclear if the cougar suffered from the tumor.

The hunter is not required to hand over the carcass to the conservation office.

From Discovery News

Mechanical properties of nanomaterials are altered due to electric field

Mechanical properties of nanomaterials can be altered due to the application of voltage, University of Wyoming researchers have discovered.

The researchers, led by TeYu Chien, a UW assistant professor in the Department of Physics and Astronomy, determined that the electric field is responsible for alterating the fracture toughness of nanomaterials, which are used in state-of-the-art electronic devices. It is the first observed evidence that the electric field changes the fracture toughness at a nanometer scale.

This finding opens the way for further investigation of nanomaterials regarding electric field-mechanical property interactions, which is extremely important for applications and fundamental research.

Chien is the lead author of a paper, titled "Built-in Electric Field Induced Mechanical Property Change at the Lanthanum Nickelate/Nb-doped Strontium Titanate Interfaces," that was recently published in Scientific Reports. Scientific Reports is an online, open-access journal from the publishers of Nature. The journal publishes scientifically valid primary research from all areas of the natural and clinical sciences.

Other researchers who contributed to the paper are from the University of Arkansas, University of Tennessee and Argonne National Laboratory in Argonne, Ill.

Chien and his research team studied the surfaces of the fractured interfaces of ceramic materials, including lanthanum nickelate and strontium titanate with a small amount of niobium. The researchers revealed that strontium titanate, within a few nanometers of the interfaces, fractured differently from the strontium titanate away from the interfaces.

The two ceramic materials were chosen because one is a metallic oxide while the other is a semiconductor. When the two types of materials come into contact with each other, an intrinsic electric field will automatically be formed in a region, known as the Schottky barrier, near the interface, Chien explains. The Schottky barrier refers to the region where an intrinsic electric field is formed at metal/semiconductor interfaces.

The intrinsic electric field at interfaces is an inevitable phenomenon whenever one material is in contact with another. The electric field effects on the mechanical properties of materials are rarely studied, especially for nanomaterials. Understanding electric field effects is extremely important for applications of nanoelectromechanical system (NEMS), which are devices, such as actuators, integrating electrical and mechanical functionalities on the nanoscale.

For NEMS materials made in nanoscale, understanding the mechanical properties affected by electric fields is crucial for full control of device performance. The observations in this study pave the way to better understand the mechanical properties of nanomaterials.

"The electric field changes the inter-atomic bond length in the crystal by pushing positively and negatively charged ions in opposite directions," Chien says. "Altering bond length changes bond strength. Hence, the mechanical properties, such as fracture toughness."

Read more at Science Daily

Quiet quasar has apparently eaten its fill

Astronomers with the Sloan Digital Sky Survey (SDSS) announced that a distant quasar ran out of gas.

Their conclusions, reported Jan. 8 at the American Astronomical Society meeting in Kissimmee, Florida, clarify why quasar SDSS J1011+5442 changed so dramatically in the handful of years between observations.

"We are used to thinking of the sky as unchanging," said University of Washington astronomy professor Scott Anderson, who is principal investigator of the SDSS's Time-Domain Spectroscopic Survey. "The SDSS gives us a great opportunity to see that change as it happens."

Quasars are the compact area at the center of large galaxies, usually surrounding a massive black hole. The black hole at the center of J1011+5442, for example, is some 50 million times more massive than our sun. As the black hole gobbles up superheated gas, it emits vast amounts of light and radio waves. When SDSS astronomers made their first observations of J1011+5442 in 2003, they measured the spectrum of the quasar, which let them understand the properties of the gas being swallowed by the black hole. In particular, the prominent "hydrogen-alpha" line in the spectrum revealed how much gas was falling into the central black hole.

The SDSS measured another spectrum for this quasar in early 2015, and noticed a huge decrease between 2003 and 2015. The team made use of additional observations by other telescopes over those 12 years to narrow down the period of change.

"The difference was stunning and unprecedented," said UW astronomy graduate student John Ruan, a member of the research team. "The hydrogen-alpha emission dropped by a factor of 50 in less than 12 years, and the quasar now looks like a normal galaxy."

The change was so great that throughout the SDSS collaboration and astronomy community, the quasar became known as a "changing-look quasar." The black hole is still there, of course, but over the past 10 years, it appears to have swallowed all the gas in its vicinity. With the gas fallen into the black hole, the SDSS team were unable to detect the spectroscopic signature of the quasar.

"This is the first time we've seen a quasar shut off this dramatically, this quickly," said lead author Jessie Runnoe, a postdoctoral researcher at Pennsylvania State University.

Before Runnoe, Ruan and their colleagues could come to this conclusion, they had to rule out two other possibilities. A thick layer of dust could have passed through the host galaxy, obscuring their view of the black hole at its center. But, they concluded that there is no way that any dust cloud could have moved fast enough to cause a 50-fold drop in brightness in just two years. Another possibility is that the bright quasar in 2003 was just a temporary flare caused by the black hole ripping apart a nearby star. While this possibility has been invoked in similar cases, it cannot to explain the fact that the changing-look quasar had been shining for many years before it turned off.

The team's conclusion is that the quasar has used up all the glowing-hot gas in its immediate vicinity, leading to a rapid drop in brightness.

"Essentially, it has run out of food, at least for the moment," says Runnoe. "We were fortunate to catch it before and after."

Read more at Science Daily