Nov 12, 2016

Breakthrough in the quantum transfer of information between matter and light

New research is paving the way to producing quantum communications networks.
From stationary to flying qubits at speeds never reached before…. This feat, achieved by a team from Polytechnique Montréal and France's Centre national de la recherche scientifique (CNRS), brings us a little closer to the era when information is transmitted via quantum principles.

A paper titled "High-Fidelity and Ultrafast Initialization of a Hole-Spin Bound to a Te Isoelectronic Centre in ZnSe" was recently published in the journal Physical Review Letters. The creation of a qubit in zinc selenide, a well-known semi-conductor material, made it possible to produce an interface between quantum physics that governs the behaviour of matter on a nanometre scale and the transfer of information at the speed of light, thereby paving the way to producing quantum communications networks.

Classical physics vs. quantum physics

In today's computers, classical physics rules. Billions of electrons work together to make up an information bit: 0, electrons are absent and 1, electrons are present. In quantum physics, single electrons are instead preferred since they express an amazing attribute: the electron can take the value of 0, 1 or any superposition of these two states. This is the qubit, the quantum equivalent of the classical bit. Qubits provide stunning possibilities for researchers.

An electron revolves around itself, somewhat like a spinning top. That's the spin. By applying a magnetic field, this spin points up, down, or simultaneously points both up and down to form a qubit. Better still, instead of using an electron, we can use the absence of an electron; this is what physicists call a "hole." Like its electron cousin, the hole has a spin from which a qubit can be formed. Qubits are intrinsically fragile quantum creature, they therefore need a special environment.

Zinc selenide, tellurium impurities: a world first

Zinc selenide, or ZnSe, is a crystal in which atoms are precisely organized. It is also a semi-conductor into which it is easy to intentionally introduce tellurium impurities, a close relative of selenium in the periodic table, on which holes are trapped, rather like air bubbles in a glass.

This environment protects the hole's spin -- our qubit -- and helps maintaining its quantum information accurately for longer periods; it's the coherence time, the time that physicists the world over are trying to extend by all possible means. The choice of zinc selenide is purposeful, since it may provide the quietest environment of all semiconductor materials.

Polytechnique Montréal and CNRS of France, a team effort

Philippe St-Jean, a doctoral student on Professor Sébastien Francoeur's team, uses photons generated by a laser to initialize the hole and record quantum information on it. To read it, he excites the hole again with a laser and then collects the emitted photons. The result is a quantum transfer of information between the stationary qubit, encoded in the spin of the hole held captive in the crystal, and the flying qubit -- the photon, which of course travels at the speed of light.

This new technique shows that it is possible to create a qubit faster than with all the methods that have been used until now. Indeed, a mere hundred or so picoseconds, or less than a billionth of a second, are sufficient to go from a flying qubit to a static qubit, and vice-versa.

Read more at Science Daily

Dinosaurs' rise was 'more gradual,' new fossil evidence suggests

The skull of Buriolestes.
Researchers have discovered two small dinosaurs together with a lagerpetid, a group of animals that are recognized as precursors of dinosaurs. The discovery made in Brazil and reported in the Cell Press journal Current Biology on November 10 represents the first time that a dinosaur and a dinosaur precursor have ever been found together.

The new lagerpetid (Ixalerpeton) and saurischian dinosaur (Buriolestes) were unearthed from the ~230-million-year-old Carnian Santa Maria Formation -- one of the oldest known rock units including dinosaur fossils anywhere in the world.

"We now know for sure that dinosaurs and dinosaur precursors lived alongside one another and that the rise of dinosaurs was more gradual, not a fast overtaking of other animals of the time," says Max Langer of Brazil's Universidade de São Paulo.

The discovery clearly shows that these animals were contemporaries of each other during the earliest stages of dinosaurs' evolution. The new lagerpetid specimen also preserves the first skull, scapular, and forelimb elements, plus associated vertebrae, known for the group, the researchers report. Tooth evidence also shows that the first dinosaurs most likely fed on "all kinds of small animals, but most probably not plants," Langer says.

Those details help to reveal how dinosaurs acquired some of their characteristic anatomical traits. Their analysis also suggests that Buriolestes is one of the oldest known Sauropodomorpha, the group of long-necked dinosaurs that includes sauropods.

The two new animals have already helped to fill important gaps in the evolution of the key anatomical features of dinosaurs. But Langer and his colleagues aren't done with them yet. They are using CT scans to characterize and describe the animals' anatomy in even greater detail. They also hope to get an even more precise radioisotopic date on the oldest dinosaur-bearing rocks, and the search for more Triassic fossils continues.

From Science Daily

Australian Telescope Joins Hunt for Intelligent Aliens

A radio telescope near the town of Parkes, Australia, this week joined the privately funded Breakthrough Listen project in hopes of discovering evidence that a technically advanced civilization exists beyond Earth.

The Parkes telescope's first target was Proxima Centauri, a red dwarf star that is the sun's nearest neighbor. In August, astronomers announced that an Earth-size planet circles the star at the right distance for water, if any exists, to pool on its surface — a condition believed to be necessary for life.

Chances are slim the planet, known as Proxima b, is home to a technically advanced civilization, says Andrew Siemion, director of the University of California-Berkeley's SETI Research Center.

"But once we knew there was a planet right next door, we had to ask the question," said Siemion, who heads the Breakthrough Listen science program.

"It was a fitting first observation for Parkes," he said in a statement.

Breakthrough Listen also uses two U.S. telescopes — the Green Bank Telescope in West Virginia and the Automated Planet Finder at the Lick Observatory in California — but neither are positioned to observe Proxima Centauri and other targets in the Southern Hemisphere.

Breakthrough Listen is a 10-year, $100-million search for extraterrestrial intelligence, or SETI, project funded by internet entrepreneur Yuri Milner and backed by British physicist Stephen Hawking and other well-known astronomers.

The project, announced last year, began searching for non-naturally occurring radio signals in January. It is the most comprehensive search for ET to date.

From Discovery News

Nov 11, 2016

Neanderthal inheritance helped humans adapt to life outside of Africa

We owe our long-lost hominid relatives for various traits, and especially those related to our immune systems and skin, the evidence shows.
As the ancestors of modern humans made their way out of Africa to other parts of the world many thousands of years ago, they met up and in some cases had children with other forms of humans, including the Neanderthals and Denisovans. Scientists know this because traces of those meetings remain in the human genome. Now, researchers reporting in the Cell Press journal Current Biology on November 10 find more evidence that those encounters have benefited humans over the years.

All told, the new study identifies 126 different places in the genome where genes inherited from those archaic humans remain at unusually high frequency in the genomes of modern humans around the world. We owe our long-lost hominid relatives for various traits, and especially those related to our immune systems and skin, the evidence shows.

"Our work shows that hybridization was not just some curious side note to human history, but had important consequences and contributed to our ancestors' ability to adapt to different environments as they dispersed throughout the world," says Joshua Akey of University of Washington School of Medicine in Seattle.

Akey says it's relatively straightforward today to identify sequences that were inherited from archaic ancestors. Studies show that non-African individuals inherited about 2% of their genomes from Neanderthals. People of Melanesian ancestry inherited another 2% to 4% of their genomes from Denisovan ancestors. But it hasn't been clear what influence those DNA sequences have had on our biology, traits, and evolutionary history.

In the new study, the researchers took advantage of recently constructed genome-scale maps of Neanderthal and Denisovan sequences identified in more than 1,500 geographically diverse people. Their sample included close to 500 individuals each from East Asia, Europe, and South Asia. They also analyzed the genomes of 27 individuals from Island Melanesia, an area including Indonesia, New Guinea, Fiji, and Vanuatu. The researchers were searching for archaic DNA sequences in those human genomes at frequencies much higher than would be expected if those genes weren't doing people any good.

While the vast majority of surviving Neanderthal and Denisovan sequences are found at relatively low frequencies (typically less than 5%), the new analyses turned up 126 places in our genomes where these archaic sequences exist at much higher frequencies, reaching up to about 65%. Seven of those regions were found in parts of the genome known to play a role in characteristics of our skin. Another 31 are involved in immunity.

"The ability to increase to such high population frequencies was most likely facilitated because these sequences were advantageous," Akey explains. "In addition, many of the high-frequency sequences span genes involved in the immune system, which is a frequent target of adaptive evolution."

Generally speaking, the genes humans got from Neanderthals or Denisovans are important for our interactions with the environment. The evidence suggests that hybridization with archaic humans as our ancient ancestors made their way out of Africa "was an efficient way for modern humans to quickly adapt to the new environments they were encountering."

Read more at Science Daily

Mars' Mega-Drought Revealed in Meteorite Rust

As the world looks toward Mars as the first destination for humanity's foray into the solar system, it's time for a reality check.

We already know the Red Planet is bathed in radiation, has a thin atmosphere and is, for the most part, inhospitable for life (as we know it), but astrobiologists think there might be just enough water below the surface to support microbial life and there was likely a lot more water on the surface in the Red Planet's past. The mere hint of water on Mars is enough for us to hope we can use it to sustain a future Mars settlement.

Now, in new research published in the journal Nature Communications, researchers report on the results of analysis of Mars meteors by NASA's Opportunity rover that has been exploring Mars for over 12 years.

Iron-rich meteorites weather very quickly when exposed to a wet environment. On Earth, these space rocks rust. And though meteorites also rust on Mars, Opportunity has found that they rust at a much, much slower rate and has revealed that the planet has been extremely dry for millions of years.

"Evidence shows that more than 3 billion years ago Mars was wet and habitable. However, this latest research reaffirms just how dry the environment is today," said Christian Schröder, of the University of Stirling and Science Team Collaborator for the Mars Exploration Rover Opportunity, in a statement. "For life to exist in the areas we investigated, it would need to find pockets far beneath the surface, located away from the dryness and radiation present on the ground."

Although recent discoveries by NASA's Curiosity rover suggest liquid water infused with toxic perchlorate salts might condense on the surface, the reality is that the Martian atmosphere is still extremely arid. "(T)his moisture is much less than the moisture present even in the driest places on Earth," added Schröder.

After studying a cluster of meteorites in the equatorial Meridiani Planum region of Mars, Opportunity found that their rust rate is 10-10,000 times less than how long it would take iron-rich meteorites to rust in the driest deserts on Earth. This suggests Mars has been incredibly dry for millions of years, only adding more mystery to how the Red Planet transitioned from a wet planet to a very dry one.

This is obviously pretty bad news for the hope of finding any basic forms of Martian life remotely near the surface, but it adds another layer of uncertainty for future Mars missions. For any Mars mission plan, tapping into Mars' meager water supply is essential to keep astronauts alive and, in some cases, provide fuel for a sustained presence. This most recent finding will no doubt force mission planners to carefully consider where a future human presence on Mars should touch down, and it probably won't be anywhere near the equator.

From Discovery News

Fly Spit Could Be the Key to Skin Infection Vaccine

The saliva of a sand fly may help to prevent a horrific skin infection that now affects millions of people in the tropics, subtropics and southern Europe.

Ironically, the infection, cutaneous leishmaniasis, develops when a sand fly infected with Leishmania parasites bites a person. The bite can turn into a raised red lesion that, in some cases, may form an open ulcer that can then become infected with bacteria. Sores in the nose and mouth may cause further complications.

"People get this disease if they visit areas where the sand fly occurs, like parts of Brazil, India and Iran," Camil de Oliveira of the Instituto Gonçalo Moniz, Fundação Oswaldo Cruz in Brazil told Seeker. "The name sand fly is not related to the insect being found on the beach."

In Brazil, one of 10 countries where 75 percent of cutaneous leishmaniasis cases are concentrated, the infection is generally caused by the parasite Leishmania braziliesis, and is transmitted in the spit of the biting sand flies Lutzomyia intermedia and Lutzomyia whitmani. Prior research found that immunity to proteins in Lutzomyia intermedia's saliva exacerbated leishmaniasis, resulting in an increased immune response to the bites of infected sand flies.

For the new study, published in the journal PLOS Neglected Tropical Diseases, de Oliveira, Aldina Barral and their team tested the effect of immunity to the other major sand fly, Lutzomyia whitmani, on leishmaniasis. As you might imagine, the small insects produce a tiny amount of spit, making the research quite a challenge.

The flies "produce very little of it, and we need to obtain the flies, separate the females — the ones that have the salivary molecules we are interested in — and then dissect the salivary glands," de Oliveira said. "It is all very small and we need the use of lab equipment to do the dissection."

The scientists next immunized mice with the fly spit. They then injected the mice with some of the infection-causing parasites. The mice that were previously immunized with the fly saliva did not develop lesions, but other mice that had no such treatment did. The researchers also noted that the immunized mice had lower levels of parasites at the injection sites and higher levels of certain immune molecules.

The scientists next tested 300 people from Corte de Pedra, Brazil. Some of them had the infection, others had a lesser version of it without the lesions, and still others had no history of the disease. De Oliveira and colleagues detected the antibodies in all three groups of people, but patients with lesions had the lowest levels.

Together, the experiments strongly suggest that immunity against the infection is possible, and that the fly saliva helps to boost an individual's ability to fight off leishmaniasis. Why this happens remains a mystery, since insects do not even have antibodies.

"Nevertheless," de Oliveira said, "they can recognize invaders and trigger different mechanisms of defense … For sand flies, little is known about how they may fight off Leishmania parasites, however, they can survive Leishmania presence and thrive."

Read more at Discovery News

Long-Lost Tropical Bed Bugs Are Back in the US

After a suspected 60-year absence from the U.S., a bed bug known for its ability to spread rapidly has just invaded Florida and Hawaii, according to experts who study the parasitic pest.

The tropical bed bug Cimex hemipterus is raising concern because traditional eradication methods might not keep its numbers in check.

"To the naked eye, the common bed bug (Cimex lectularius) and the tropical bed bug would look the same, as would signs of their presence: bites, blood spots on linens and shed skin from the bugs," University of Florida entomologist Brittany Campbell told Seeker. She added that the parasites can cause everything from small bite marks to serious allergic reactions that require immediate medical attention.

"Under a microscope, the two species look different," continued Campbell, who recently authored a report on tropical bed bugs for Entomology Today. "The tropical bed bug has a different-shaped pronotum, or neck-like structure, that doesn't have the 'U-shape' characteristic of common bed bugs."

The bed bug's existence in Hawaii is anecdotal, she said, but more is known about its presence in Florida, thanks to an observant homeowner from Merritt Island near the Ulumay Wildlife Sanctuary in Brevard County, Fla. In 2015 the family reported an infestation, and a sample was sent to Campbell. She and her team discovered the bed bug was from the long-lost tropical species.

From the late 1930s to the early 1940s, the bug was found in several Florida counties. But it hadn't been reported again until the Merritt Island incident. As its name suggest, it's often found in tropical environments including Africa, parts of Australia, Asia and South America.

The parasite favors warm, humid environments, so Campbell said that it potentially could spread to other southern states, parts of California and additional places in the U.S. In fact, because of indoor heating, it might be able to establish itself nearly anywhere, she and other bed bug authorities speculate.

The Merritt Island residence is now free of bed bugs, but how the home became infested in the first place is a mystery that has Campbell concerned. The family hadn't traveled outside of the state, so it's likely the insects became established in Florida before arriving in Brevard County — possibly hitching a ride with tourists or on a cargo shop.

"We have probably encountered the tropical bed bug and not even known it," John Cooksey told Seeker. He works at McCall Service, a family-owned pest control company that's operates in Florida and Georgia. "Our bed bug business is up 12 percent over last year."

Read more at Discovery News

Mystery Stellar Swirls Are Baby Planets' First Steps

The cosmos is often viewed as constant and unchanging, but in these wonderfully detailed observations of the protoplanetary disks surrounding young stars, some rather rapid changes are being witnessed.

While zooming in on young stars surrounded by the dusty debris from star formation, the SPHERE instrument, which is attached to the ESO's powerful Very Large Telescope (VLT) at the Paranal Observatory in Chile, was able to resolve details in the early evolution of planetary systems. During the formation of our solar system over 4 billion yours ago, the components of all the planets would have resembled the rippled tracks as seen in these observations. As with many fields of astronomy, we often look out into the galaxy to learn more about our own origins.

Though astronomers have a pretty good idea about how planets are formed, many mysteries remain. This is particularly the case when planets take their "first steps," gaining the gravitational fortitude to attract more material and carving out intricate tracks and swirls in stars' surrounding disks.

Of the recent observations, one remarkably young star system called RX J1615 (pictured below), located around 600 light-years from Earth and only 1.8 million years old, shows amazingly intricate symmetrical rings around the central star. "The disc shows hints of being shaped by planets still in the process of formation," the ESO writes in a statement.

But not all planet "baby steps" form these symmetrical Saturn-like rings. One burgeoning star system called HD 135344B, located around 450 light-years away, exhibits an asymmetrical whirlpool-like ring of debris and tracks in the protoplanetary disk (below). And the interesting thing about this particular star system is that astronomers have seen changes in the disk structure morph over a period of only a few months. This is a star system forming in real time and SPHERE is providing astronomers with a powerful new tool to track wisps of dusty material get swept up by the motion of baby planets.

"By building an impressive body of knowledge about these protoplanetary discs, these teams are stepping closer to understanding how planets shape the discs that form them — and therefore understanding planet formation itself," the ESO added.

From Discovery News

Nov 10, 2016

Australian continent shifts with the seasons, study finds

Fourteen GPS stations across Australia show the direction of the continent's shift from month to month.
Australia shifts and tilts back and forth by several millimeters each year because of changes to Earth's center of mass, according to a new study. The findings could help scientists better track the precise location of Earth's center of mass, which is important for GPS and other satellite measurements, according to the study's author.

All bodies have a center of mass, or the average position of the mass of an object. Earth's center of mass lies roughly at the center of the planet's molten core, about 6,000 kilometers (about 3,700 miles) beneath the surface.

Seasonal changes to the distribution of water on Earth's surface -- largely through precipitation and evaporation -- shift the planet's center of mass a few millimeters in different directions.

The new study finds these movements cause Earth's smallest continent to move back and forth with the seasons. Australia moves northwest by about 1 millimeter during its summer (winter in the Northern Hemisphere). At the same time, its northwestern edge tilts downwards by 2 to 3 millimeters, while the southeastern edge is lifted up by 2 to 3 millimeters. During its winter (summer in the Northern Hemisphere), the trend reverses, and the continent shifts southeast and reverses its tilt.

These changes are not enough to be felt by the country's inhabitants but are enough to be detected by satellites.

"[Water] migrates every season," said Shin-Chan Han, a professor of engineering at the University of Newcastle in Australia, and lead author of the new study published in the Journal of Geophysical Research: Solid Earth, a journal of the American Geophysical Union. "That motion causes quite a detectable, sizable deformation in Australia."

Down under

Earth is roughly spherical, but the distribution of mass on its surface is not perfectly balanced. Water moves around the globe through precipitation and evaporation, and its average location depends largely on the seasons. At certain times, water accumulates more in some areas than in others, which causes slight changes to the planet's center of mass.

When snowpacks in the Northern Hemisphere are at their peaks, the weight of water is strong enough to shift Earth's center of mass a few millimeters closer to Europe. But six months later, when much of the rain and snow has returned to the atmosphere through evaporation, the center of mass moves closer to the south Pacific Ocean.

Han was looking to see if local changes in water near Australia might cause the continent to shift or move. The tectonic plate underneath Australia rests on a conveyor belt of molten rock called the asthenosphere. Convection in the asthenosphere moves each plate several centimeters every year, but the plates can also shift from other forces, including changes in where water is located.

To track Australia's motion, Han measured changes in the locations of 14 land-based GPS stations across the continent. Although they orbit about 20,000 kilometers (12,500 miles) above Earth's surface, GPS satellites can detect changes to land-based stations that are smaller than a millimeter.

Han then used data from the Gravity Recovery and Climate Experiment (GRACE), which uses two satellites to measure changes in the strength of gravitational pull over Earth, to measure the location of water.

By combining the new GPS and GRACE data, Han could measure how much the seasonal movement of water affected Australia. He found the continent shifts and tilts by several millimeters in response to the changes in water location far from Australia. These changes to water location affect Earth's center of mass. All continents move slightly with the change in center of mass, but Australia experiences this more because it is directly in between Europe and the south Pacific Ocean, according to Han.

From Australia's motion, Han was able to calculate the motion of Earth's center of mass. The movement of the continent corresponded the movement of Earth's center of mass. Although other methods can measure this movement, Han's method is a secondary, independent check.

Han's study shows GPS measurements across Australia are likely a millimeter or two off. While this may not amount to much of a difference on a day-to-day basis, it could be a concern for precision measurements, like those taken to determine sea level, he said.

Read more at Science Daily

Secret Passageway Found at Shakespeare's Theater

A secret passageway has been found beneath the stage of the theater where William Shakespeare's Henry V, and possibly Romeo and Juliet, were first performed.

The unusual feature was found at the site of the Curtain Theater, one of London's earliest playhouses. Excavations showed the stage of the 16th-century building was much longer than originally thought, and contained evidence of a mysterious passageway running beneath it.

"The passage would allow actors to pass unseen from one side of the stage to the other. This raises lots of questions as to how early plays were staged," Heather Knight, senior archaeologist at the Museum of London Archaeology (MOLA), told Seeker.

Re-discovered in 2011 behind a pub in Shoreditch, east London, the Curtain — named after the road it fronted — opened in 1577. It was only a few hundred yards from London's first playhouse, The Theater, which had opened a year before, in 1576.

The theater is closely connected with Shakespeare. It was home to his Company, the Lord Chamberlain's Men, from 1597 until another playhouse, The Globe, opened two years later.

Despite being immortalized as "this wooden O" in Henry V, the Curtain was intentionally built as a rectangular playhouse.

"This was not a re-purposed space with a stage, it was a place where people came to be immersed in entertainment," MOLA said in a statement.

Moreover the stage, measuring nearly 46 feet long and just under 16 feet wide, had a shape unlike any other Elizabethan theaters.

The finding raises questions about the function of the theater and the types of entertainment that might have been staged there.

"Did the unusual shape and layout of the Curtain stage influence the plays such as Henry V and Romeo and Juliet that he wrote before his company moved to the Globe with a different stage? As well as drama, could the Curtain's stage space have been used for sporting spectacles?" Knight wondered.

She added that more in-depth analysis of the finds will follow to shed some light on some of those mysteries.

Meanwhile, the researchers learned that the Curtain was one of the earliest Elizabethan playhouses where people paid money to see performances.

It had timber galleries with mid and upper areas for those who could afford to spend more and a courtyard made from compacted gravel for those with less to spend.

Knight's team found fragments of ceramic money boxes which would have been used to collect the entry fees from theatergoers. The boxes were then smashed and the released money counted in a separate room that was called the 'box office' — the term we still use today.

Read more at Discovery News

Dinosaur's Slow Death Captured in 'Saddest' Fossil

The well-preserved remains of a new dinosaur nicknamed "Mud Dragon" likely freeze in time the death pose of the animal after its agonizing final breaths.

The new species, Tongtianlong limosus, meaning "muddy dragon on the road to heaven," was discovered lying in rock that formed from what was once hardened mud. The dinosaur, described in the journal Scientific Reports, appeared to have been trying to free itself from the mud, with its wings and neck outstretched.

Co-author Stephen Brusatte of the University of Edinburgh's School of Geosciences and his colleagues believe that the unfortunate dinosaur died in the throes of this struggle about 66–72 million years ago.

"It is one of the most beautiful, but saddest fossils I've ever seen," Brusatte told Seeker, adding that if the dinosaur had not died stuck in mud "we wouldn't have this gorgeous fossil."

Tongtianlong limosus skeleton.
The two-legged dinosaur was an oviraptorosaur, referring to a family of feathered dinosaurs known for their short, toothless heads and sharp beaks. Some, such as Mud Dragon, had crests of bone on their heads that were probably used for displays to attract mates and to intimidate rivals. Birds like today's cassowaries feature such crests.

Brusatte said that the winged, yet probably flightless, dinosaur looked like a bird.

"If you saw it alive, I bet you would have just considered it to be a weird type of fairly large bird," he explained. "It was about the size of a sheep or small donkey."

Despite the dinosaur's misfortune, it is a miracle that its skeleton was found. Construction workers at a building site in the Ganzhou region of southern China were blasting the ground with dynamite in order to make way for a high school. An explosion revealed Mud Dragon, coming close to blowing it to smithereens.

In addition to the dinosaur's revealing death pose, its fossils reveal what ecosystems were like just before the asteroid impact of 66 million years ago that killed off all of the non-bird dinos.

A conservator works beside the remains of Tongtianlong limosus.
Mud Dragon is the sixth known oviraptorosaur from the late Cretaceous Period of this region in China. Although these dinosaurs were all related, each looked distinctive, strongly suggesting that the animals were diversifying — branching off into new species — and flourishing before the asteroid hit occurred.

Some researchers believe that dinosaurs were already in decline and that the asteroid just finished them off, but Brusatte said "that is a bunch of malarkey."

"Everything we see in the fossil record — particularly here in southern China — tells us dinosaurs were flourishing right up to the end," he continued. "There were a bunch of species living together, dominating ecosystems, and still forming new species right up to the final moments."

Read more at Discovery News

Predatory Bacteria Can Cannibalize Drug-Resistant Bugs

Antimicrobial resistance is one of the greatest public health threats of our time, with more than 700,000 people dying each year from drug-resistant strains of TB, malaria and HIV/AIDS. Without new methods of killing these fast-mutating microbes, an estimated 50 million people a year could die from drug-resistant infections by 2050.

"Without effective antibiotics, we'll be thrust back into the mid-1800s," Robert J. Mitchell, a microbiology professor and researcher at the Ulsan National Institute of Science and Technology in Korea, told Seeker. Mitchell is one of a handful of global scientists studying a unique strain of "predatory bacteria" that could hunt down and kill drug-resistant bugs inside a patient's body.

According to a new paper, these so-called "vampire" bacteria — named for their nasty habit of latching on to other microbes and sucking out their innards — have successfully hunted down and killed pneumonia inside the lungs of sick rats. The paper, authored by Daniel Kadouri of the Rutgers Medical School, presents compelling new evidence that vampire bacteria could become a viable weapon against the rising threat of superbugs.

Predatory bacteria were first identified in 1962 as fast-swimming bacteria that attack and eat other bacteria. They're found everywhere in the natural environment, in soils, oceans, rivers, lakes, and are even present in the human gut. The favorite strain of predator bacteria among researchers like Mitchell and Kadouri are called Bdellovibrio-and-like-organisms (BALOS).

"These bacteria are able to penetrate the double membrane of Gram-negative bacteria, enter into the prey and consume it from the inside out," says Mitchell. After sucking down a tasty meal, the BALOS use the energy boost to multiply. "A predator can produce anything from two to seven progeny from a single prey.

Scientists don't know enough about predatory bacteria to "program" the hungry suckers to target specific microbes. The best current technique, Mitchell explains, is to identify naturally occurring predators that have a "taste" for certain kinds of diseases. Once the predator bacteria are isolated in culture, researchers must feed them daily to keep them alive and reproducing. Then it's time to set them loose on disease pathogens.

Kadouri's rat experiments were the first ever to employ therapeutic predatory bacteria in living mammals. Before that it was just fish and chickens. The dream is to one day test these disease-hunting bacteria in humans. Earlier this year, both Mitchell and Kadouri proved in separate studies that BALOS pose no threat to healthy human cells in culture. Testing on real people is still years away.

Read more at Discovery News

Nov 9, 2016

Comet Chury is much younger than previously thought

"Chury" with his bi-lobe structure and the weakest part, the neck.
Based on computer simulations, Astrophysicists at the University of Bern, Switzerland, conclude that the comet Chury did not obtain its duck-like form during the formation of our solar system 4.5 billion years ago. Although it does contain primordial material, they are able to show that the comet in its present form is hardly more than a billion years old.

Based on data from the Rosetta space probe, scientists have so far assumed that the comet 67P/Churyumov-Gerasimenko originated from the initial phase of our solar system. Its peculiar, duck-shaped structure would have resulted from a gentle collision of two objects about 4.5 billion years ago.

Based on new research, Martin Jutzi and Willy Benz from NCCR PlanetS and the Center for Space and Habitability (CSH) of the University of Bern, together with colleagues, have now come to a different conclusion. As a result of two studies published in the journal Astronomy & Astrophysics, Astrophysicist Martin Jutzi explains that "It is unlikely that a body like Chury has survived for such a long time without damage -- our computer simulations show this. "

If the assumptions of the present "standard" model of the origin of our solar system are correct, a quiet initial phase was followed by a period in which large bodies initiated higher velocities and more violent collisions. In a first study, the scientists calculated how much energy would be needed to destroy a structure like Chury in a collision. As it turned out, Chury has a weak point; the connection between the two parts -- the neck between the head and the body. "We have found that this structure can be destroyed easily, even with low energy collisions," Martin Jutzi summarizes. Willy Benz compares the neck of the comet with the stem of a glass: "A dishwasher has to clean very gently, so that the stem of the glass does not break," says the astrophysicist. Obviously, the solar system did not handle this aspect as carefully.

The new study shows that comets like Chury experienced a significant number of collisions over time, the energy of which would have been sufficient to destroy a bi-lobe structure. Therefore, the shape is not primordial, but has developed through collisions over billions of years. "Chury's present shape is the result of the last major impact which probably occurred within the last billion years," says Martin Jutzi. The duck-shaped Chury is therefore much younger than previously thought. The only alternative would be that the current standard model of the early evolution of the Solar System is not correct and there were fewer small objects than previously thought. In this case there would not have been as many collisions and Chury would have had the chance to keep its primordial shape. "At the moment, we do think though that Chury's shape is the result of many collisions, and that the standard model doesn't need to be revised," says Jutzi.

New shape, same content

In the second paper, Jutzi and Benz investigate exactly how Chury's current form could have resulted from a collision. In their computer models, they had small objects with a diameter of 200 to 400 meters crashing into a roughly five-kilometre, rotating body in the form of a rugby ball (see animation). The impact speed was in the range of 200 to 300 meters per second, which clearly exceeds the escape velocity for objects of this size (about 1 meter per second). However, the energy involved is still far below that of a catastrophic impact in which a large part of the body is pulverized. As a result, the target was torn in two parts, which, due to the effects of their mutual gravitational force, later merged into a structure with two parts -- a structure like Chury.

Read more at Science Daily

Brazilian free-tailed bat is the fastest flyer in the animal kingdom

Catch me if you can: the Brazilian free-tailed bat can reach record-breaking speeds.
Up to now, the speed record for horizontal flight was held by birds from the swift family: the common swift, for example, can reach speeds of over 100 kilometers per hour. Together with colleagues from the USA, researchers at the Max Planck Institute for Ornithology in Radolfzell have now discovered a new front-runner among the acrobats of the air. However, the animal involved here is not a bird but a bat: the Brazilian free-tailed bat shoots through the night skies at over 160 kilometers per hour. Their aerodynamic body shape and longer than average wings compared to other bat species enable them to reach such vast speeds.

Birds are still a model for aviation engineers today and remain unequaled when it comes to flight characteristics. While birds can take off at comparatively low speeds, even the most modern aircraft must reach a speed of around 300 kilometers per hour to be able to lift off. The main contributing factors here are the animals' aerodynamic, projectile-like body shape and their low weight due to special bones. Moreover, the narrow wings found in faster-flying species also enable greater lift relative to the aerodynamic force invested.

Swifts, like the common swift (Apus apus), which can reach speeds of 110 kilometers per hour, are considered the fastest birds in the world at horizontal flight. Peregrine falcons can even reach speeds of up to 300 kilometers per hour when diving. In contrast, due to their wing structure, bats generate greater resistance, and are generally considered slower flyers.

Animals with long and narrow wings usually fly faster than those with shorter and wider ones. For this reason, the scientists selected the Brazilian free-flying bat (Tadarida brasiliensis) for their study. Even the experts themselves were surprised by their results: "Initially, we could hardly believe our data, but they were correct: at times, the female bats, which weigh between 11 and 12 grams, flew at speeds of over 160 kilometers per hour -- a new record for horizontal flight," says Kamran Safi from the Max Planck Institute for Ornithology.

Read more at Science Daily

Mammalian bone gene may be repurposed to fuel cognition in humans

DNA illustration
A gene that regulates bone growth and muscle metabolism in mammals may take on an additional role as a promoter of brain maturation, cognition and learning in human and nonhuman primates, according to a new study led by neurobiologists at Harvard Medical School.

Describing their findings in the Nov. 10 issue of Nature, researchers say their work provides a dramatic illustration of evolutionary economizing and creative gene retooling -- mechanisms that contribute to the vast variability across species that share nearly identical set of genes yet differ profoundly in their physiology.

The research reveals that osteocrin -- a gene found in the skeletal muscles of all mammals and well-known for its role in bone growth and muscle function -- is completely turned off in rodent brains yet highly active in the brains of nonhuman primates and humans.

Notably, osteocrin was found predominantly in cells of the neocortex -- the most evolved part of the primate brain, which regulates sensory perception, spatial reasoning and higher-level thinking and language in humans.

The gene's marked presence in an area of the brain responsible for higher-level function and thought, the researchers said, suggests a possible role in the development of cognition, a cardinal feature that distinguishes the brains of human and nonhuman primates from those of other mammals.

Brain development in humans and other primates is profoundly affected by sensory experience and social interactions. Scientists have long sought to unravel genes in the brain that are turned on and off by experiences to fuel the rise of brain functions unique to such complex species.

The HMS team's findings -- part of an ongoing quest to elucidate the mechanisms that underlie human brain development, function and disease -- reveal that osteocrin is precisely one such gene, activated by sensory stimulation. Furthermore, the team added, this is the first illustration of evolutionary gene repurposing in the brain.

"We have uncovered what we believe is a critical clue into the evolution of the human brain, one that gives us a glimpse into the genetic mechanisms that may account for differences in cognition between mice and humans," said senior investigator Michael Greenberg, the Nathan Marsh Pusey Professor of Neurobiology and chair of the HMS Department of Neurobiology.

For their experiments, the team analyzed RNA levels -- the molecular footprints of gene activity -- in the brain cells of mice, rats and humans. Although many of the same genes were activated in both mouse and human brain cells, the scientists observed, a small subset of genes was activated solely in human brain cells. Much to the scientists' surprise, the bone gene osteocrin was most highly expressed in the human brain, yet completely shut off in the brain cells of mice.

Going a step further, the scientists placed brain cells from all three species in lab dishes and chemically re-created conditions that mimic sensory stimulation. Chemical stimulation activated osteocrin selectively in excitatory neurons, so called for their role in stimulating rather than dampening nerve signaling. But researchers noted something even more intriguing: The activity of the gene was most intense in neurons of the neocortex, the topmost layer of cells covering the brain and responsible for higher-level cognition, such as long-term memory, thought and language. At the same time, osteocrin was noticeably absent from other parts of the brain responsible for noncognitive functions such as spatial navigation, balance, breathing, heart rate and temperature control.

When researchers compared osteocrin levels to levels of another brain protein, BDNF, well known for its role in neuronal growth and repair, they noticed another striking difference. While BDNF was present throughout the brain, osteocrin was restricted to the neocortex and, to a lesser extent, the amygdala, an area of the brain thought to play a role in memory formation, decision making and emotional responses. Osteocrin was also markedly expressed in cells of the temporal lobe, which houses functions such as learning, memory and audio-visual processing -- and the occipital lobe, which houses the visual cortex, the area of the brain responsible for the processing of visual information.

Further analysis revealed that in the primate brain, sensory stimulation appears to switch on osteocrin through a previously unknown DNA enhancer. Enhancers -- snippets of DNA that act as the genome's regulators -- are the "handles" that turn on some genes while shutting off others. In doing so, enhancers can profoundly alter genetic expression, fueling dramatic differences between organisms with nearly identical DNA. The rodent versions of osteocrin lacked the stimulation-activated DNA enhancer, the analysis showed.

In yet another critical observation, researchers found the osteocrin enhancer was, in turn, switched on by a protein called MEF2. Mutations in MEF2 are a well-established cause of intellectual disability and neurodevelopmental disorders, so the link between the two begs further study, the researchers said, as it may portend a role for osteocrin in such developmental anomalies.

"Humans share many genes with rodents and as much as 90 percent of their DNA in some parts of the genome," says co-first author Gabriella Boulting, a neurobiologist at HMS. "In this case we see how turning up the expression of the same gene in a different location may precipitate dramatic differences in the function of brain cells."

Further analysis revealed that osteocrin's activation curbed the growth of neuronal dendrites -- branchlike projections responsible for transmitting signals from one brain cell to the next.

"Restricting dendritic growth is a precision-enhancing mechanism, essential to ensuring that neuronal wires don't get crossed and compromise signal transmission from one cell to the next," says study first co-author Bulent Ataman, a neurobiologist at HMS.

This observation, Ataman added, suggests that osteocrin's activity may help enhance nerve cell agility and proper signal transmission to ensure robust communication across neurons.

To confirm that the activity-induced gene expression observed in nerve cells in the lab also occurred in the functioning, intact brain, researchers temporarily blocked vision in one eye of a macaque, a common technique to study activity-triggered brain plasticity and visually-induced gene activation in the visual cortex. This proof-of-concept experiment, they surmised, would reveal whether osteocrin is, indeed, awakened by visual stimulation and shut off by its absence. A day later, the researchers observed that osteocrin expression was markedly higher in cells from the visually intact parts of the macaque brain, compared with cells in vision-deprived areas.

The findings illustrate a foundational principle in neurobiology -- abnormal visual experiences can interfere with the development and function of brain cells in the visual cortex, a phenomenon first described more than 50 years ago by David Hubel and Torsten Wiesel, two of the founding members of the Department of Neurobiology at HMS. The two shared the 1981 Nobel Prize in Physiology or Medicine for their discoveries on visual information processing in the brain.

Read more at Science Daily

Brain Implant Could Help Paraplegics Walk Again

A groundbreaking new technology unveiled this week could enable paraplegics to walk again by sending signals wirelessly from the brain to the lower part of the spine.

The neuroprosthetic interface, developed by an international team of scientists and technicians, acts as bridge between the brain's motor cortex and the spine. Brain signals are picked up by an implant in the skull and then translated by a small computer, which relays the information — wirelessly and immediately — to electrodes implanted in the spine.

The spinal electrodes are placed in the lumbar region, below the injury or lesion that otherwise prevents signals from passing through the nerves. The electrodes, in turn, stimulate the neural pathways that activate leg muscles when walking or running. The interface essentially creates a wireless connection between the brain and the spine, potentially allowing those with spinal injuries to walk again.

So far, the system has only been tested on monkeys, but initial results indicate that the system could work with humans, according to the research team.

David Borton, assistant professor of engineering with Brown University and co-author of the new study, said that spinal stimulation studies with humans are being evaluated, but there are no clinical trials in the works just yet.

"The current paper shows encouraging evidence that such brain recording and spinal stimulation could be used in a human rehabilitation context, but no studies are currently planned," Brown said in an email to Seeker.

According to the study, officially published today in the journal Nature, two rhesus monkeys were outfitted with the neuroprosthetic earlier this year. Both monkeys had one leg paralyzed by a spinal cord lesion. On June 23, 2015, the first monkey regained control of its paralyzed leg, less than one week after the initial injury. The second monkey recovered within two weeks. Both animals were able to walk again, without training, both on the ground and on treadmills.

The neuroprosthetic interface was conceived at EPFL in Switzerland, and developed together with an international network of collaborators including Irish medical device company Medtronic, Brown University and the German research institution Fraunhofer ICT-IMM. Testing was performed in collaboration with the University of Bordeaux, Motac Neuroscience and the Lausanne University Hospital (CHUV).

As you might imagine, the technical details are complex (you can peruse the research paper itself at Nature) but the system basically consists of five components: the brain implant, a brain-recording device, a computer, an implantable pulse generator and a spinal implant.

The brain implant technology has previously been deployed to control movement in prosthetic hands and, in one case, a patient's fully paralyzed hand. But this is the first time it's been used for spinal injuries.

The computer element of the system extracts specific intentional information from the brain implant, then translates the data using special algorithms. The data is beamed wirelessly to the pulse generator, which delivers the instructed patterns of simulation to the spinal implant. The spinal implant activates groups of muscles in the paralyzed leg, inducing flexing and extension movements.

Read more at Discovery News

Nov 8, 2016

Diamond collection brings deep Earth to the surface

Analysis of diamonds from the Denver Museum of Nature & Science collection provide a look inside Earth's mantle.
Researchers at the Denver Museum of Nature & Science and University of British Columbia recently analyzed diamonds from the Museum's collection and learned how an unusual chunk of Africa formed.

It takes incredible heat and pressure to form a diamond. And when these diamonds were formed, microscopic minerals were trapped inside. The chemistry of these minerals, or inclusions, provides a rare look at the processes that led to the formation of Earth's crust. Inclusions found in the Museum's diamonds from the Congo craton in central southern Africa illustrate an incredible 3-billion-year journey through tectonic collisions and volcanic eruptions.

The international scientific team, led by author Charles W. Kosman, used an electron microprobe, an infrared spectrometer and a secondary ion mass spectrometer to analyze these diamonds.

"These diamonds are special," Kosman said. "They're the ultimate time capsules from deep Earth."

The researchers determined that the diamonds formed as thinner continental fragments and began their journey beneath the thick, buoyant continental crust of central Africa. Over 2.8 billion years, this part of the African continent repeatedly rammed into smaller and thinner fragments. These fragments slid downward back toward Earth's core where they were dehydrated by extreme heat and pressure, triggering the formation of diamonds. The diamonds were then brought to the surface in volatile eruptions, which pierced the hide of the ancient African continent and eventually deposited the diamonds on the surface.

"The circumstances that led to the formation of these diamonds trapping invaluable information inside are incredible," said James Hagadorn, Museum's curator of geology. "Grueling conditions -- temperatures five times hotter than your oven, and pressure 10 times that found below Mount Everest -- are what it takes to freeze clues to Earth's evolution for studies such as this one."

By knowing how and where diamonds like these are formed, it also informs the ability to predict where to find future diamond deposits. Museum collections are often overlooked as a resource for clues to Earth's delicate atmospheric history.

Read more at Science Daily

Neanderthal DNA Is Being Purged From Our Genomes

Another Neanderthal extinction is taking place now, and it's happening in our genomes, suggests new research that finds natural selection is slowly removing Neanderthal genetic variants from modern populations.

Our ancestors interbred with Neanderthals when they migrated out of Africa, yet people of European and Asian ancestry today are only about 1 to 4 percent Neanderthal, according to most estimates. The new study, published in PLOS Genetics, helps explain what happened to all of those other Neanderthal gene signatures that were more evident right after our species — known as anatomically modern humans, or AMH — mated with Neanderthals.

"So the first generation of hybrids would have been half Neanderthal and half AMH because they had one Neanderthal parent and one AMH parent," senior author Graham Coop, a professor in the UC Davis Department of Evolution and Ecology and Center for Population Biology, told Seeker.

"Later generations of hybrids may have more or less Neanderthal ancestry," he continued, "depending on whether they had more Neanderthal or AMH ancestors (e.g. great grandparents)."

Coop said they're finding that the early Neanderthal-human mixes seem to have inherited mostly weak gene variants from their Neanderthal parents.

To understand the phenomenon, we need to go further back in time. It is widely believed that the ancestors of Neanderthals split from our African ancestors over half a million years ago. Because there was a longstanding connection before then, we share the majority of our genome with Neanderthals. This DNA is not described as being Neanderthal, however, as the Neanderthals only started to evolve as a unique population after the split with AMH occurred.

Once in Europe and Asia, the Neanderthals evolved genetic variants in response to their living conditions. It's believed that they existed in small, isolated populations, given the often chilly climate and what resources were available to them.

Another migration occurred around 50,000–80,000 years ago, when AMH left Africa and spread through Europe and Asia, encountering and interbreeding with Neanderthals. The nature of those encounters remains a mystery, but DNA evidence show they happened.

Some of the genetic variants inherited from Neanderthals are beneficial. People from Tibet, for example, can breathe easier in high elevations thanks to their Neanderthal heritage. Other Neanderthal genetic variants, however, are not so great.

"Small, long isolated populations are relatively more inbred than large populations," Coop explained, adding that such groups can accumulate gene variants that aren't very helpful to our survival. This is the DNA that is gradually disappearing from the genomes of people with European and Asian heritage.

Coop and his team devised methods to measure the degree of natural selection acting on Neanderthal DNA, and were able to show how this purging is happening slowly over time.

Svante Pääbo, director of the Max Planck Institute for Evolutionary Anthropology, previously told Seeker "that there are regions of the modern human genomes where we would statistically expect to see a contribution from Neanderthals but do not. So in some regions of the modern human genome there seem to be selection against a Neanderthal contribution."

Read more at Discovery News

Shackle-Bound Skeleton Found in Etruscan Burial

Archaeologists digging in central Tuscany have brought to light a dark side of the Etruscan civilization, unearthing a 2,500-year-old skeleton still bound by shackles on his neck and ankles.

The finding appears to be the first case of an Etruscan burial containing a shackled individual.

The unusual grave was found in Populonia, a unique Etruscan settlement built directly on the sea. There, in a simple pit dug into the sandy soil near the beach of Baratti, the archaeologists found the complete skeleton of a male between 20 and 30 years of age.

Almost five pounds of iron bound his legs, while a heavy iron collar was wrapped around his neck.

"He died in shackles and was buried with a shroud tied to the body. We found a black spot under the nape, most likely what remained of a wood object which was likely connected to the iron collar," Giorgio Baratti, professor of archaeology at the University of Milan, told Seeker.

It's likely the unfortunate man endured a device that was connected from the head to the feet with perishable materials such as ropes or leather.

An iron ring found in one of his left fingers might have been part of the device, which was meant to impede his ability to take long steps.

Baratti, whose last name is oddly the same of the beach where the skeleton was unearthed, believes the man was likely a slave or someone who had to bear a definitive punishment.

A slave might have been employed in maritime activities as well as in the iron mines in the area. Between the 6th and 4th centuries B.C., Populonia was the main center in the Mediterranean for iron processing, with the metal coming mainly from the Elba island.

"Notably, he was interred in a necropolis which features normal burials. This is something you would not expect," Baratti said.

Detail of shackles around the ankles.
Despite the lack of grave goods, Baratti was able to date the shackle burial to at least the 5th century B.C.

"Right on top of the shackled man, we found the grave of a woman buried with earrings and other goods which clearly date to the 4th century B.C. We estimate that at least a century had passed before they built a new necropolis," Baratti said.

The finding reveals a lesser known aspect of the Etruscan civilization, which began to flourish around 900 B.C., and dominated much of Italy for five centuries. Known for their art, agriculture, fine metalworking and commerce, the Etruscans became absorbed into the Roman empire by 300-100 B.C.

Their richly decorated tombs have painted an image of a fun-loving and eclectic people who respected women and taught the French how to make wine, the Romans how to build roads, and introduced the art of writing into Europe.

The shackled man reveals a more disturbing side of the traditional Etruscan image.

"They could be cruel as well," Baratti said.

Read more at Discovery News

Massive Lake Found Under Bolivian Volcano

A team of researchers has discovered an enormous reservoir of water mixed with magma, or semi-molten rock, roughly nine miles beneath Uturuncu, a dormant volcano in the Andes.

In an article published in the journal Earth and Planetary Science Letters, the scientists say there that there may be many lakes deep in the Earth beneath other volcanoes as well, and that the bodies of water may explain how and why eruptions happen. The lakes also may play a role in the formation of the Earth's crust.

The subterranean lake apparently contains a volume of water that's somewhere between Lake Huron (850 cubic miles) and Lake Superior (2,903 cubic miles), according to Jon Blundy, a volcano researcher and professor at the UK's University of Bristol, who was one of the study's authors.

According to New Scientist, Blundy and colleagues discovered the massive lake while investigating the Altiplano-Puna magma body, an even more massive underground formation that slows down seismic waves and conducts electricity.

The researchers took rocks ejected by an eruption of Uturuncu that occurred half a billion years ago, mixed them with water in the lab and then subjected them to pressure and temperature conditions comparable to those deep in the Earth. They found that with a mix of about eight to 10% water, the electrical conductivity matched the actual Altiplano-Puna.

That data matched other formations that have been discovered beneath volcanoes such as Mount St. Helen's in Washington state, which led the researchers to suspect that such bodies of water could be a common feature of the areas underneath volcanoes.

Blundy told New Scientist that the water mixed with magma may explain the composition of rocks in the Earth's continental crust. When the magma — which is mostly composed of basalt — rises up from the Earth's mantle, the hot layer below the crust, the water helps enrich the basalt with silica and depletes magnesium. That eventually forms rocks such as andesite, a fine-grained igneous rock.

Read more at Discovery News

Nov 7, 2016

Ancient Irish Grave Yields Europe's Oldest Polished Ax

Ireland's oldest human grave has become even more exceptional for one of its contents: The oldest polished ax on record in Europe was likely created solely for a burial, archaeologists say.

The finding sheds new light on the beliefs and complex funerary rituals of the early Mesolithic hunter-gatherers who lived in Ireland about 9,500 years ago, from about 7530 B.C., the researchers said.

"This type of insight into burial practices is incredibly rare for this part of the world," the study's lead researcher Aimée Little, an archaeologist at the University of York in the United Kingdom, told Live Science in an email. "Nine thousand years ago, people in Ireland were making very high-quality artifacts specifically to be placed in graves."

Researchers discovered the grave at Hermitage, a site along the River Shannon in Limerick, in 2001. They noted the burial's contents — including the "exceptional" polished shale adze, or ax — at the time, but Little and her colleagues decided to take a second look by analyzing the microwear on the ax, they wrote in the study.

That analysis revealed the ax was little-used, one sign to "suggest that this object was commissioned for the deceased and employed in their funerary rites," the researchers wrote in the study. What's more, the ax was deliberately blunted, possibly as a symbolic act, "as a ritual expression of the death of the individual," the researchers wrote.

This ritual appears to be groundbreaking for its time, the researchers said.

"The adze is exceptional as we traditionally associate [these] polished axes and adzes like this with the arrival of agriculture in Europe, around 3,000 years later," study co-author Ben Elliott, a postdoctoral research associate of archaeology at the University of York, said in a statement. "Although polished axes and adzes are known from pre-agricultural sites in Ireland and other parts of Europe, to find such a well-made, highly polished and securely dated example is unprecedented for this period of prehistory."

The polished ax isn't the only unexpected finding within the grave. Rather than a body covered by rocks or dirt, the grave contains buried cremated ashes, which is unusual for such an old grave, the researchers said.

"That the earliest recorded grave in Ireland is a cremation, and there are two more cremations of later date at the site, suggesting this was a special place known about and returned to over hundreds of years," Little said.

Read more at Discovery News

Fossilized Leaves Reveal How Earth Recovered After Mass Extinction

Recreation of an asteroid hitting Earth.
About 66 million years ago, an asteroid slammed into Earth, causing a mass extinction event that wiped out the dinosaurs. What happened in the years following the devastation has long been a mystery due to lack of evidence.

Now researchers have discovered clues thanks to a surprising find: insect damage to plants now fossilized in rock. The damage suggests that half of Earth recovered twice as fast as the other half.

"We compared insect damage diversity in Patagonia and Western Interior North America before and after the asteroid impact," lead researcher Michael Donovan of Pennsylvania State University explained to Seeker. "In both Patagonia and North America, we observed a decrease in insect damage diversity on fossil leaves that lived in the early Paleocene, after the asteroid hit Earth."

"However," he added, "in Patagonia, insect damage diversity increased to pre-extinction levels in 4 million years, much faster than the 9 million years it took in North America." Donovan and his team reported their findings in the journal Nature Ecology & Evolution.

Insect damage, including multiple small leaf mines (upper right) and margin feeding (upper left), on a fossil leaf from an early Paleocene fossil plant locality, Las Flores (~62.3 million years old), in Patagonia, Argentina.
Other researchers have proposed that after the asteroid smashed into Earth near what is now Chicxulub, Mexico, the planet saw increased volcanic activity and severe climate change. Those events have been implicated in wiping out all dinosaurs that didn't evolve into birds, as well as numerous other plants, insects and animals on land and in the seas.

The fossilized leaves of flowering plants suggest that just before the destruction happened, a wide range of insects at various places on the planet were happily munching away on plants. Shortly after the asteroid hit, this feeding activity stopped. When the researchers focused only on leaf miners — numerous insects, such as moths and flies, whose larvae burrow into and feed on leaves — the evidence for annihilation was incredibly stark.

"We found no evidence for the survival of any of the Cretaceous leaf miners in Patagonia, similar to previous findings from North America," Donovan said.

Insect galls on a fossil leaf from the latest Cretaceous Lefipán Formation (67-66 million years old) in Patagonia, Argentina.
Some leaf miners must have survived elsewhere, though, since these insects live on to this day. Birds, the early ancestors of mammals, certain fish and other species also managed to survive, becoming more established as the years went on. The recovery, at least for insects and flowering plants, happened over twice as fast in the Southern Hemisphere as it did the Northern Hemisphere.

As for why, Donovan said, "One possibility is distance from the Chicxulub crater in Mexico." He thinks that other "poorly understood factors may have also contributed" to the major difference in recovery times.

Read more at Discovery News

Thorny Devils Bury Themselves in Sand to Drink Water

The scales of thorny devils are a scientific marvel; these lizards use their skin like a drinking straw. But where does the water come from that allows them to survive in Australia's driest deserts?

Scientists have studied the water-wicking properties of thorny devil skin for more than 40 years.

Channels between the animals' scales draw moisture towards their mouths, where they squeeze it inside in miniscule gulps.

But in the devils' habitat — the arid deserts and sandy plains of central and western Australia — what hasn't been clear is exactly where they get the water from.

Do they rely on rare puddles, or harvest droplets of condensation, or do they suck water from the sand itself?

A study published today (November 2) in the Journal of Experimental Biology suggests that one of the main ways thorny devils drink is by burying their bodies in damp sand, and then drawing the moisture out of it.

Philip Withers, a professor of zoology at the University of Western Australia and co-author of the research, said the creatures' remarkable skin is critical to their survival in the harsh conditions of the desert.

"Clearly, it's important for them — this special system has evolved and it's really quite bizarre," he said.

"I think it might be more important for the extreme circumstances. You get a little bit of rain and the sand gets wet, and then it's really important to be able to suck the water out of the sand."

Thorny devils can't simply lick water from puddles or drops of condensation because their entire mouth — including the jaw and tongue — has evolved specifically to feed on small ants that share their habitat.

So this lizard has evolved a bizarre alternative to drinking with its mouth: the capillary channels on its skin squeeze every last drop of moisture out of the arid landscape and push it towards the animal's mouth.

Professor Withers said although scientists already knew about this, they weren't sure whether thorny devils could fill their capillary channels and drink just by standing on moist sand.

To find out, the researchers studied analysed how much water six thorny devils could suck up in different situations.

The animals began to open and close their mouths to drink just 10 seconds after being placed in a puddle of water.

But when placed on wet sand, only 59 per cent of the devils' capillaries filled up and the lizards didn't start drinking.

"They can certainly stand in a puddle of water and suck it up and drink it," Professor Withers said.

"But [what we discovered is] they probably can't just stand on moist sand and suck it up and drink it.

"They can absorb some water that way, but it's not enough to fill the capillary channels."

The researchers believe that if these channels aren't full enough, water won't be pushed into the mouth for the devil to drink.

Thorny devils have been observed sand-shoveling after periods of rain.

Using replica models of the lizard's skin, the scientists showed that piling sand on top of this unusual surface boosted the amount of moisture that could be sucked into capillary channels. Gravity, they suggest, gives the process a helping hand.

And while they haven't yet measured the results of shoveled sand on live lizards, they believe all the signs point to this self-burial in damp sand as the behavior that allows devils to fill their capillaries and drink.

By piling it onto their backs, the thorny devils maximize the surface area of their skin touching the sand — as well as getting gravity's help in sucking the moisture from it.

Professor Withers thinks the mechanism isn't necessary for the day-to-day survival of the lizard but may be useful in lengthy periods where there is little or no rainfall.

"I would think that a normal desert lizard can survive in the desert eating ants, without all of this stuff," he said.

"So maybe it's just for when it's really hot and dry, a long drought or something and there's a bit of rainfall — they can harvest it."

The thorny devil is spiked as a form of defense against predators.

The slow-moving lizard sits on ant trails to feed, picking off ants one by one with its tongue as they walk by.

This makes the devil a stationary target for would-be predators, who are warded off by the spikes that make the lizards difficult to eat.

Read more at Discovery News

Here are 5 Simple Ways to Put the Brakes on Climate Change

Diplomats from 196 nations are gathering in Marrakesh this week will face intense pressure to translate its planet-saving promise into action. The Twenty-Second Conference of the Parties (COP-22), a follow-up to the 2015 Paris meeting, is a chance to start putting political undertakings into practice.

Under the 2015 Paris Agreement, UN members pledged to cap rising temperatures at less than 2 degrees Celsius (2.6 degrees Fahrenheit) compared to pre-industrial era levels.

The big culprit is CO2, the byproduct of fossil fuels that provide the backbone of today's energy supply.

But addressing indirect CO2 emissions — and warming sources that are not from CO2 — offer complementary ways of slowing the temperature rise.

Earth is hurtling deep into the red zone of dangerous global warming, but experts say there are some low cost, effective options for putting on the brakes.

"The overarching objective is crystal clear: We need to cut CO2 emissions, and we need to do it as quickly as possible," said Rachel Cleetus at the Washington-based advocacy group, the Union of Concerned Scientists (UCS).

Here are some of the main options:


Hydrofluorocarbons (HFCs) are the poster child of potential "low-hanging fruit" in the carbon cleanup.

These are gases used in air conditioning and refrigeration — invented, ironically, to replace other gases that had ripped a hole in the ozone layer. And they are viciously effective at trapping solar heat — one type of HFC is more than 15,000 times more efficient than CO2 in this regard.

An amendment to the 1987 Montreal Protocol signed by nearly 200 countries last month assures the phase out of HFCs by mid-century, avoiding up to a 0.5C (0.9F) of global warming by 2100.

Black carbon

Black carbon — more commonly known as soot — consists of dark particles cast off by the inefficient burning of diesel fuel, wood and other biomass such as dung.

Like CO2, soot contributes to warming in the atmosphere.

But it causes far more damage by settling on snow at high altitude and in the Arctic, regions warming twice as fast as the global average.

Pristine snow reflects more than 80 percent of solar radiation back into space. But when blanketed by soot, it absorb heat instead.

Implementing known solutions "could reduce soot by 70 to 80 percent," said Drew Shindell, a professor at Duke University.

Methane leaks

The second biggest contributor to global warming after CO2 — methane — comes mainly from oil and gas production leaks, livestock, and rice paddies.

Global emissions of methane have been rising sharply since 2007, and may be twice as high as previously thought, according to an assessment published last month in Nature.

A large slice of that increase comes from the booming shale gas industry in the United States, said Stefan Schwietzke, a scientist at the UN National Oceanic and Atmospheric Administration and lead author of the study.

The good news, he told AFP, is that this jump also means greater "potential to reduce climate forcing from this specific source is also greater."

"We have calculated that — if you put into place all the existing, proven methods to reduce methane and soot —you could slow the rate of global warming over the next three decades by about half-a-degree Celsius," Shindell noted.


Global livestock — mainly cows and sheep, both gas-passing ruminants — is probably a larger source of methane than the fossil fuel industry, according to Doug Boucher, a scientist at the UCS.

"There are some technical ways of reducing methane, such as improving feed for cattle," he told AFP. "But the real potential comes from shifting diets away from high-emission foods, especially beef."

Even switching from beef to chicken or pork would have a big impact, reducing emissions by almost the same amount as if all beef-eaters become vegetarians.

But weaning North and South Americans — by far the biggest consumers of beef — from hamburgers and T-bone steaks is easier said than done.

"There is a very strong resistance, culturally," Boucher said. "It is considered food-policing."

Another simple target is food waste.

About a third of all food produced in the world is lost during production or consumption, according to the UN, accounting for about eight percent of greenhouse gas emissions.

Read more at Discovery News